Improve handling of statement expressions ({}):
[cparser] / parser.c
1 /*
2  * This file is part of cparser.
3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version 2
8  * of the License, or (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
18  * 02111-1307, USA.
19  */
20 #include <config.h>
21
22 #include <assert.h>
23 #include <stdarg.h>
24 #include <stdbool.h>
25
26 #include "parser.h"
27 #include "diagnostic.h"
28 #include "format_check.h"
29 #include "lexer.h"
30 #include "symbol_t.h"
31 #include "token_t.h"
32 #include "types.h"
33 #include "type_t.h"
34 #include "type_hash.h"
35 #include "ast_t.h"
36 #include "entity_t.h"
37 #include "lang_features.h"
38 #include "walk_statements.h"
39 #include "warning.h"
40 #include "adt/bitfiddle.h"
41 #include "adt/error.h"
42 #include "adt/array.h"
43
44 //#define PRINT_TOKENS
45 #define MAX_LOOKAHEAD 2
46
47 typedef struct {
48         entity_t           *old_entity;
49         symbol_t           *symbol;
50         entity_namespace_t  namespc;
51 } stack_entry_t;
52
53 typedef struct argument_list_t argument_list_t;
54 struct argument_list_t {
55         long              argument;
56         argument_list_t  *next;
57 };
58
59 typedef struct gnu_attribute_t gnu_attribute_t;
60 struct gnu_attribute_t {
61         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
62         gnu_attribute_t     *next;
63         bool                 invalid;        /**< Set if this attribute had argument errors, */
64         bool                 have_arguments; /**< True, if this attribute has arguments. */
65         union {
66                 size_t              value;
67                 string_t            string;
68                 atomic_type_kind_t  akind;
69                 long                argument;  /**< Single argument. */
70                 argument_list_t    *arguments; /**< List of argument expressions. */
71         } u;
72 };
73
74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
75 struct declaration_specifiers_t {
76         source_position_t  source_position;
77         storage_class_t    storage_class;
78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
79         bool               is_inline    : 1;
80         bool               thread_local : 1;  /**< GCC __thread */
81         bool               deprecated   : 1;
82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
87         type_t            *type;
88 };
89
90 /**
91  * An environment for parsing initializers (and compound literals).
92  */
93 typedef struct parse_initializer_env_t {
94         type_t     *type;   /**< the type of the initializer. In case of an
95                                  array type with unspecified size this gets
96                                  adjusted to the actual size. */
97         entity_t   *entity; /**< the variable that is initialized if any */
98         bool        must_be_constant;
99 } parse_initializer_env_t;
100
101 /**
102  * Capture a MS __base extension.
103  */
104 typedef struct based_spec_t {
105         source_position_t  source_position;
106         variable_t        *base_variable;
107 } based_spec_t;
108
109 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
110
111 /** The current token. */
112 static token_t              token;
113 /** The lookahead ring-buffer. */
114 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
115 /** Position of the next token in the lookahead buffer. */
116 static int                  lookahead_bufpos;
117 static stack_entry_t       *environment_stack = NULL;
118 static stack_entry_t       *label_stack       = NULL;
119 static scope_t             *file_scope        = NULL;
120 static scope_t             *current_scope     = NULL;
121 /** Point to the current function declaration if inside a function. */
122 static function_t          *current_function  = NULL;
123 static entity_t            *current_init_decl = NULL;
124 static switch_statement_t  *current_switch    = NULL;
125 static statement_t         *current_loop      = NULL;
126 static statement_t         *current_parent    = NULL;
127 static ms_try_statement_t  *current_try       = NULL;
128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
129 static goto_statement_t    *goto_first        = NULL;
130 static goto_statement_t   **goto_anchor       = NULL;
131 static label_statement_t   *label_first       = NULL;
132 static label_statement_t  **label_anchor      = NULL;
133 /** current translation unit. */
134 static translation_unit_t  *unit              = NULL;
135 /** true if we are in a type property context (evaluation only for type. */
136 static bool                 in_type_prop      = false;
137 /** true in we are in a __extension__ context. */
138 static bool                 in_gcc_extension  = false;
139 static struct obstack       temp_obst;
140 static entity_t            *anonymous_entity;
141 static declaration_t      **incomplete_arrays;
142
143
144 #define PUSH_PARENT(stmt)                          \
145         statement_t *const prev_parent = current_parent; \
146         ((void)(current_parent = (stmt)))
147 #define POP_PARENT ((void)(current_parent = prev_parent))
148
149 /** special symbol used for anonymous entities. */
150 static const symbol_t *sym_anonymous = NULL;
151
152 /* symbols for Microsoft extended-decl-modifier */
153 static const symbol_t *sym_align         = NULL;
154 static const symbol_t *sym_allocate      = NULL;
155 static const symbol_t *sym_dllimport     = NULL;
156 static const symbol_t *sym_dllexport     = NULL;
157 static const symbol_t *sym_naked         = NULL;
158 static const symbol_t *sym_noinline      = NULL;
159 static const symbol_t *sym_returns_twice = NULL;
160 static const symbol_t *sym_noreturn      = NULL;
161 static const symbol_t *sym_nothrow       = NULL;
162 static const symbol_t *sym_novtable      = NULL;
163 static const symbol_t *sym_property      = NULL;
164 static const symbol_t *sym_get           = NULL;
165 static const symbol_t *sym_put           = NULL;
166 static const symbol_t *sym_selectany     = NULL;
167 static const symbol_t *sym_thread        = NULL;
168 static const symbol_t *sym_uuid          = NULL;
169 static const symbol_t *sym_deprecated    = NULL;
170 static const symbol_t *sym_restrict      = NULL;
171 static const symbol_t *sym_noalias       = NULL;
172
173 /** The token anchor set */
174 static unsigned char token_anchor_set[T_LAST_TOKEN];
175
176 /** The current source position. */
177 #define HERE (&token.source_position)
178
179 /** true if we are in GCC mode. */
180 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
181
182 static type_t *type_valist;
183
184 static statement_t *parse_compound_statement(bool inside_expression_statement);
185 static statement_t *parse_statement(void);
186
187 static expression_t *parse_sub_expression(precedence_t);
188 static expression_t *parse_expression(void);
189 static type_t       *parse_typename(void);
190 static void          parse_externals(void);
191 static void          parse_external(void);
192
193 static void parse_compound_type_entries(compound_t *compound_declaration);
194
195 typedef enum declarator_flags_t {
196         DECL_FLAGS_NONE             = 0,
197         DECL_MAY_BE_ABSTRACT        = 1U << 0,
198         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
199         DECL_IS_PARAMETER           = 1U << 2
200 } declarator_flags_t;
201
202 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
203                                   declarator_flags_t flags);
204
205 static entity_t *record_entity(entity_t *entity, bool is_definition);
206
207 static void semantic_comparison(binary_expression_t *expression);
208
209 #define STORAGE_CLASSES       \
210         STORAGE_CLASSES_NO_EXTERN \
211         case T_extern:
212
213 #define STORAGE_CLASSES_NO_EXTERN \
214         case T_typedef:         \
215         case T_static:          \
216         case T_auto:            \
217         case T_register:        \
218         case T___thread:
219
220 #define TYPE_QUALIFIERS     \
221         case T_const:           \
222         case T_restrict:        \
223         case T_volatile:        \
224         case T_inline:          \
225         case T__forceinline:    \
226         case T___attribute__:
227
228 #define COMPLEX_SPECIFIERS  \
229         case T__Complex:
230 #define IMAGINARY_SPECIFIERS \
231         case T__Imaginary:
232
233 #define TYPE_SPECIFIERS       \
234         case T__Bool:             \
235         case T___builtin_va_list: \
236         case T___typeof__:        \
237         case T__declspec:         \
238         case T_bool:              \
239         case T_char:              \
240         case T_double:            \
241         case T_enum:              \
242         case T_float:             \
243         case T_int:               \
244         case T_long:              \
245         case T_short:             \
246         case T_signed:            \
247         case T_struct:            \
248         case T_union:             \
249         case T_unsigned:          \
250         case T_void:              \
251         case T_wchar_t:           \
252         COMPLEX_SPECIFIERS        \
253         IMAGINARY_SPECIFIERS
254
255 #define DECLARATION_START   \
256         STORAGE_CLASSES         \
257         TYPE_QUALIFIERS         \
258         TYPE_SPECIFIERS
259
260 #define DECLARATION_START_NO_EXTERN \
261         STORAGE_CLASSES_NO_EXTERN       \
262         TYPE_QUALIFIERS                 \
263         TYPE_SPECIFIERS
264
265 #define TYPENAME_START      \
266         TYPE_QUALIFIERS         \
267         TYPE_SPECIFIERS
268
269 #define EXPRESSION_START           \
270         case '!':                        \
271         case '&':                        \
272         case '(':                        \
273         case '*':                        \
274         case '+':                        \
275         case '-':                        \
276         case '~':                        \
277         case T_ANDAND:                   \
278         case T_CHARACTER_CONSTANT:       \
279         case T_FLOATINGPOINT:            \
280         case T_INTEGER:                  \
281         case T_MINUSMINUS:               \
282         case T_PLUSPLUS:                 \
283         case T_STRING_LITERAL:           \
284         case T_WIDE_CHARACTER_CONSTANT:  \
285         case T_WIDE_STRING_LITERAL:      \
286         case T___FUNCDNAME__:            \
287         case T___FUNCSIG__:              \
288         case T___FUNCTION__:             \
289         case T___PRETTY_FUNCTION__:      \
290         case T___alignof__:              \
291         case T___builtin_alloca:         \
292         case T___builtin_classify_type:  \
293         case T___builtin_constant_p:     \
294         case T___builtin_expect:         \
295         case T___builtin_huge_val:       \
296         case T___builtin_inf:            \
297         case T___builtin_inff:           \
298         case T___builtin_infl:           \
299         case T___builtin_isgreater:      \
300         case T___builtin_isgreaterequal: \
301         case T___builtin_isless:         \
302         case T___builtin_islessequal:    \
303         case T___builtin_islessgreater:  \
304         case T___builtin_isunordered:    \
305         case T___builtin_nan:            \
306         case T___builtin_nanf:           \
307         case T___builtin_nanl:           \
308         case T___builtin_offsetof:       \
309         case T___builtin_prefetch:       \
310         case T___builtin_va_arg:         \
311         case T___builtin_va_end:         \
312         case T___builtin_va_start:       \
313         case T___func__:                 \
314         case T___noop:                   \
315         case T__assume:                  \
316         case T_delete:                   \
317         case T_false:                    \
318         case T_sizeof:                   \
319         case T_throw:                    \
320         case T_true:
321
322 /**
323  * Allocate an AST node with given size and
324  * initialize all fields with zero.
325  */
326 static void *allocate_ast_zero(size_t size)
327 {
328         void *res = allocate_ast(size);
329         memset(res, 0, size);
330         return res;
331 }
332
333 /**
334  * Returns the size of an entity node.
335  *
336  * @param kind  the entity kind
337  */
338 static size_t get_entity_struct_size(entity_kind_t kind)
339 {
340         static const size_t sizes[] = {
341                 [ENTITY_VARIABLE]        = sizeof(variable_t),
342                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
343                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
344                 [ENTITY_FUNCTION]        = sizeof(function_t),
345                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
346                 [ENTITY_STRUCT]          = sizeof(compound_t),
347                 [ENTITY_UNION]           = sizeof(compound_t),
348                 [ENTITY_ENUM]            = sizeof(enum_t),
349                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
350                 [ENTITY_LABEL]           = sizeof(label_t),
351                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
352                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
353         };
354         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
355         assert(sizes[kind] != 0);
356         return sizes[kind];
357 }
358
359 /**
360  * Allocate an entity of given kind and initialize all
361  * fields with zero.
362  */
363 static entity_t *allocate_entity_zero(entity_kind_t kind)
364 {
365         size_t    size   = get_entity_struct_size(kind);
366         entity_t *entity = allocate_ast_zero(size);
367         entity->kind     = kind;
368         return entity;
369 }
370
371 /**
372  * Returns the size of a statement node.
373  *
374  * @param kind  the statement kind
375  */
376 static size_t get_statement_struct_size(statement_kind_t kind)
377 {
378         static const size_t sizes[] = {
379                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
380                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
381                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
382                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
383                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
384                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
385                 [STATEMENT_IF]          = sizeof(if_statement_t),
386                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
387                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
388                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
389                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
390                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
391                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
392                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
393                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
394                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
395                 [STATEMENT_FOR]         = sizeof(for_statement_t),
396                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
397                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
398                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
399         };
400         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
401         assert(sizes[kind] != 0);
402         return sizes[kind];
403 }
404
405 /**
406  * Returns the size of an expression node.
407  *
408  * @param kind  the expression kind
409  */
410 static size_t get_expression_struct_size(expression_kind_t kind)
411 {
412         static const size_t sizes[] = {
413                 [EXPR_INVALID]                 = sizeof(expression_base_t),
414                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
415                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
416                 [EXPR_CONST]                   = sizeof(const_expression_t),
417                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
418                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
419                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
420                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
421                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
422                 [EXPR_CALL]                    = sizeof(call_expression_t),
423                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
424                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
425                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
426                 [EXPR_SELECT]                  = sizeof(select_expression_t),
427                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
428                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
429                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
430                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
431                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
432                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
433                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
434                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
435                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
436                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
437                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
438                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
439                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
440         };
441         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
442                 return sizes[EXPR_UNARY_FIRST];
443         }
444         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
445                 return sizes[EXPR_BINARY_FIRST];
446         }
447         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
448         assert(sizes[kind] != 0);
449         return sizes[kind];
450 }
451
452 /**
453  * Allocate a statement node of given kind and initialize all
454  * fields with zero. Sets its source position to the position
455  * of the current token.
456  */
457 static statement_t *allocate_statement_zero(statement_kind_t kind)
458 {
459         size_t       size = get_statement_struct_size(kind);
460         statement_t *res  = allocate_ast_zero(size);
461
462         res->base.kind            = kind;
463         res->base.parent          = current_parent;
464         res->base.source_position = token.source_position;
465         return res;
466 }
467
468 /**
469  * Allocate an expression node of given kind and initialize all
470  * fields with zero.
471  */
472 static expression_t *allocate_expression_zero(expression_kind_t kind)
473 {
474         size_t        size = get_expression_struct_size(kind);
475         expression_t *res  = allocate_ast_zero(size);
476
477         res->base.kind            = kind;
478         res->base.type            = type_error_type;
479         res->base.source_position = token.source_position;
480         return res;
481 }
482
483 /**
484  * Creates a new invalid expression at the source position
485  * of the current token.
486  */
487 static expression_t *create_invalid_expression(void)
488 {
489         return allocate_expression_zero(EXPR_INVALID);
490 }
491
492 /**
493  * Creates a new invalid statement.
494  */
495 static statement_t *create_invalid_statement(void)
496 {
497         return allocate_statement_zero(STATEMENT_INVALID);
498 }
499
500 /**
501  * Allocate a new empty statement.
502  */
503 static statement_t *create_empty_statement(void)
504 {
505         return allocate_statement_zero(STATEMENT_EMPTY);
506 }
507
508 /**
509  * Returns the size of a type node.
510  *
511  * @param kind  the type kind
512  */
513 static size_t get_type_struct_size(type_kind_t kind)
514 {
515         static const size_t sizes[] = {
516                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
517                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
518                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
519                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
520                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
521                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
522                 [TYPE_ENUM]            = sizeof(enum_type_t),
523                 [TYPE_FUNCTION]        = sizeof(function_type_t),
524                 [TYPE_POINTER]         = sizeof(pointer_type_t),
525                 [TYPE_ARRAY]           = sizeof(array_type_t),
526                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
527                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
528                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
529         };
530         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
531         assert(kind <= TYPE_TYPEOF);
532         assert(sizes[kind] != 0);
533         return sizes[kind];
534 }
535
536 /**
537  * Allocate a type node of given kind and initialize all
538  * fields with zero.
539  *
540  * @param kind             type kind to allocate
541  */
542 static type_t *allocate_type_zero(type_kind_t kind)
543 {
544         size_t  size = get_type_struct_size(kind);
545         type_t *res  = obstack_alloc(type_obst, size);
546         memset(res, 0, size);
547         res->base.kind = kind;
548
549         return res;
550 }
551
552 /**
553  * Returns the size of an initializer node.
554  *
555  * @param kind  the initializer kind
556  */
557 static size_t get_initializer_size(initializer_kind_t kind)
558 {
559         static const size_t sizes[] = {
560                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
561                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
562                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
563                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
564                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
565         };
566         assert(kind < sizeof(sizes) / sizeof(*sizes));
567         assert(sizes[kind] != 0);
568         return sizes[kind];
569 }
570
571 /**
572  * Allocate an initializer node of given kind and initialize all
573  * fields with zero.
574  */
575 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
576 {
577         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
578         result->kind          = kind;
579
580         return result;
581 }
582
583 /**
584  * Free a type from the type obstack.
585  */
586 static void free_type(void *type)
587 {
588         obstack_free(type_obst, type);
589 }
590
591 /**
592  * Returns the index of the top element of the environment stack.
593  */
594 static size_t environment_top(void)
595 {
596         return ARR_LEN(environment_stack);
597 }
598
599 /**
600  * Returns the index of the top element of the global label stack.
601  */
602 static size_t label_top(void)
603 {
604         return ARR_LEN(label_stack);
605 }
606
607 /**
608  * Return the next token.
609  */
610 static inline void next_token(void)
611 {
612         token                              = lookahead_buffer[lookahead_bufpos];
613         lookahead_buffer[lookahead_bufpos] = lexer_token;
614         lexer_next_token();
615
616         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
617
618 #ifdef PRINT_TOKENS
619         print_token(stderr, &token);
620         fprintf(stderr, "\n");
621 #endif
622 }
623
624 /**
625  * Return the next token with a given lookahead.
626  */
627 static inline const token_t *look_ahead(int num)
628 {
629         assert(num > 0 && num <= MAX_LOOKAHEAD);
630         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
631         return &lookahead_buffer[pos];
632 }
633
634 /**
635  * Adds a token type to the token type anchor set (a multi-set).
636  */
637 static void add_anchor_token(int token_type)
638 {
639         assert(0 <= token_type && token_type < T_LAST_TOKEN);
640         ++token_anchor_set[token_type];
641 }
642
643 /**
644  * Set the number of tokens types of the given type
645  * to zero and return the old count.
646  */
647 static int save_and_reset_anchor_state(int token_type)
648 {
649         assert(0 <= token_type && token_type < T_LAST_TOKEN);
650         int count = token_anchor_set[token_type];
651         token_anchor_set[token_type] = 0;
652         return count;
653 }
654
655 /**
656  * Restore the number of token types to the given count.
657  */
658 static void restore_anchor_state(int token_type, int count)
659 {
660         assert(0 <= token_type && token_type < T_LAST_TOKEN);
661         token_anchor_set[token_type] = count;
662 }
663
664 /**
665  * Remove a token type from the token type anchor set (a multi-set).
666  */
667 static void rem_anchor_token(int token_type)
668 {
669         assert(0 <= token_type && token_type < T_LAST_TOKEN);
670         assert(token_anchor_set[token_type] != 0);
671         --token_anchor_set[token_type];
672 }
673
674 /**
675  * Return true if the token type of the current token is
676  * in the anchor set.
677  */
678 static bool at_anchor(void)
679 {
680         if (token.type < 0)
681                 return false;
682         return token_anchor_set[token.type];
683 }
684
685 /**
686  * Eat tokens until a matching token type is found.
687  */
688 static void eat_until_matching_token(int type)
689 {
690         int end_token;
691         switch (type) {
692                 case '(': end_token = ')';  break;
693                 case '{': end_token = '}';  break;
694                 case '[': end_token = ']';  break;
695                 default:  end_token = type; break;
696         }
697
698         unsigned parenthesis_count = 0;
699         unsigned brace_count       = 0;
700         unsigned bracket_count     = 0;
701         while (token.type        != end_token ||
702                parenthesis_count != 0         ||
703                brace_count       != 0         ||
704                bracket_count     != 0) {
705                 switch (token.type) {
706                 case T_EOF: return;
707                 case '(': ++parenthesis_count; break;
708                 case '{': ++brace_count;       break;
709                 case '[': ++bracket_count;     break;
710
711                 case ')':
712                         if (parenthesis_count > 0)
713                                 --parenthesis_count;
714                         goto check_stop;
715
716                 case '}':
717                         if (brace_count > 0)
718                                 --brace_count;
719                         goto check_stop;
720
721                 case ']':
722                         if (bracket_count > 0)
723                                 --bracket_count;
724 check_stop:
725                         if (token.type        == end_token &&
726                             parenthesis_count == 0         &&
727                             brace_count       == 0         &&
728                             bracket_count     == 0)
729                                 return;
730                         break;
731
732                 default:
733                         break;
734                 }
735                 next_token();
736         }
737 }
738
739 /**
740  * Eat input tokens until an anchor is found.
741  */
742 static void eat_until_anchor(void)
743 {
744         while (token_anchor_set[token.type] == 0) {
745                 if (token.type == '(' || token.type == '{' || token.type == '[')
746                         eat_until_matching_token(token.type);
747                 next_token();
748         }
749 }
750
751 /**
752  * Eat a whole block from input tokens.
753  */
754 static void eat_block(void)
755 {
756         eat_until_matching_token('{');
757         if (token.type == '}')
758                 next_token();
759 }
760
761 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
762
763 /**
764  * Report a parse error because an expected token was not found.
765  */
766 static
767 #if defined __GNUC__ && __GNUC__ >= 4
768 __attribute__((sentinel))
769 #endif
770 void parse_error_expected(const char *message, ...)
771 {
772         if (message != NULL) {
773                 errorf(HERE, "%s", message);
774         }
775         va_list ap;
776         va_start(ap, message);
777         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
778         va_end(ap);
779 }
780
781 /**
782  * Report an incompatible type.
783  */
784 static void type_error_incompatible(const char *msg,
785                 const source_position_t *source_position, type_t *type1, type_t *type2)
786 {
787         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
788                msg, type1, type2);
789 }
790
791 /**
792  * Expect the current token is the expected token.
793  * If not, generate an error, eat the current statement,
794  * and goto the end_error label.
795  */
796 #define expect(expected, error_label)                     \
797         do {                                                  \
798                 if (UNLIKELY(token.type != (expected))) {         \
799                         parse_error_expected(NULL, (expected), NULL); \
800                         add_anchor_token(expected);                   \
801                         eat_until_anchor();                           \
802                         if (token.type == expected)                   \
803                                 next_token();                             \
804                         rem_anchor_token(expected);                   \
805                         goto error_label;                             \
806                 }                                                 \
807                 next_token();                                     \
808         } while (0)
809
810 /**
811  * Push a given scope on the scope stack and make it the
812  * current scope
813  */
814 static scope_t *scope_push(scope_t *new_scope)
815 {
816         if (current_scope != NULL) {
817                 new_scope->depth = current_scope->depth + 1;
818         }
819
820         scope_t *old_scope = current_scope;
821         current_scope      = new_scope;
822         return old_scope;
823 }
824
825 /**
826  * Pop the current scope from the scope stack.
827  */
828 static void scope_pop(scope_t *old_scope)
829 {
830         current_scope = old_scope;
831 }
832
833 /**
834  * Search an entity by its symbol in a given namespace.
835  */
836 static entity_t *get_entity(const symbol_t *const symbol,
837                             namespace_tag_t namespc)
838 {
839         entity_t *entity = symbol->entity;
840         for (; entity != NULL; entity = entity->base.symbol_next) {
841                 if (entity->base.namespc == namespc)
842                         return entity;
843         }
844
845         return NULL;
846 }
847
848 /**
849  * pushs an entity on the environment stack and links the corresponding symbol
850  * it.
851  */
852 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
853 {
854         symbol_t           *symbol  = entity->base.symbol;
855         entity_namespace_t  namespc = entity->base.namespc;
856         assert(namespc != NAMESPACE_INVALID);
857
858         /* replace/add entity into entity list of the symbol */
859         entity_t **anchor;
860         entity_t  *iter;
861         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
862                 iter = *anchor;
863                 if (iter == NULL)
864                         break;
865
866                 /* replace an entry? */
867                 if (iter->base.namespc == namespc) {
868                         entity->base.symbol_next = iter->base.symbol_next;
869                         break;
870                 }
871         }
872         *anchor = entity;
873
874         /* remember old declaration */
875         stack_entry_t entry;
876         entry.symbol     = symbol;
877         entry.old_entity = iter;
878         entry.namespc    = namespc;
879         ARR_APP1(stack_entry_t, *stack_ptr, entry);
880 }
881
882 /**
883  * Push an entity on the environment stack.
884  */
885 static void environment_push(entity_t *entity)
886 {
887         assert(entity->base.source_position.input_name != NULL);
888         assert(entity->base.parent_scope != NULL);
889         stack_push(&environment_stack, entity);
890 }
891
892 /**
893  * Push a declaration on the global label stack.
894  *
895  * @param declaration  the declaration
896  */
897 static void label_push(entity_t *label)
898 {
899         /* we abuse the parameters scope as parent for the labels */
900         label->base.parent_scope = &current_function->parameters;
901         stack_push(&label_stack, label);
902 }
903
904 /**
905  * pops symbols from the environment stack until @p new_top is the top element
906  */
907 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
908 {
909         stack_entry_t *stack = *stack_ptr;
910         size_t         top   = ARR_LEN(stack);
911         size_t         i;
912
913         assert(new_top <= top);
914         if (new_top == top)
915                 return;
916
917         for (i = top; i > new_top; --i) {
918                 stack_entry_t *entry = &stack[i - 1];
919
920                 entity_t           *old_entity = entry->old_entity;
921                 symbol_t           *symbol     = entry->symbol;
922                 entity_namespace_t  namespc    = entry->namespc;
923
924                 /* replace with old_entity/remove */
925                 entity_t **anchor;
926                 entity_t  *iter;
927                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
928                         iter = *anchor;
929                         assert(iter != NULL);
930                         /* replace an entry? */
931                         if (iter->base.namespc == namespc)
932                                 break;
933                 }
934
935                 /* restore definition from outer scopes (if there was one) */
936                 if (old_entity != NULL) {
937                         old_entity->base.symbol_next = iter->base.symbol_next;
938                         *anchor                      = old_entity;
939                 } else {
940                         /* remove entry from list */
941                         *anchor = iter->base.symbol_next;
942                 }
943         }
944
945         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
946 }
947
948 /**
949  * Pop all entries from the environment stack until the new_top
950  * is reached.
951  *
952  * @param new_top  the new stack top
953  */
954 static void environment_pop_to(size_t new_top)
955 {
956         stack_pop_to(&environment_stack, new_top);
957 }
958
959 /**
960  * Pop all entries from the global label stack until the new_top
961  * is reached.
962  *
963  * @param new_top  the new stack top
964  */
965 static void label_pop_to(size_t new_top)
966 {
967         stack_pop_to(&label_stack, new_top);
968 }
969
970 static int get_akind_rank(atomic_type_kind_t akind)
971 {
972         return (int) akind;
973 }
974
975 /**
976  * Return the type rank for an atomic type.
977  */
978 static int get_rank(const type_t *type)
979 {
980         assert(!is_typeref(type));
981         /* The C-standard allows promoting enums to int or unsigned int (see Â§ 7.2.2
982          * and esp. footnote 108). However we can't fold constants (yet), so we
983          * can't decide whether unsigned int is possible, while int always works.
984          * (unsigned int would be preferable when possible... for stuff like
985          *  struct { enum { ... } bla : 4; } ) */
986         if (type->kind == TYPE_ENUM)
987                 return get_akind_rank(ATOMIC_TYPE_INT);
988
989         assert(type->kind == TYPE_ATOMIC);
990         return get_akind_rank(type->atomic.akind);
991 }
992
993 /**
994  * Do integer promotion for a given type.
995  *
996  * @param type  the type to promote
997  * @return the promoted type
998  */
999 static type_t *promote_integer(type_t *type)
1000 {
1001         if (type->kind == TYPE_BITFIELD)
1002                 type = type->bitfield.base_type;
1003
1004         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
1005                 type = type_int;
1006
1007         return type;
1008 }
1009
1010 /**
1011  * Create a cast expression.
1012  *
1013  * @param expression  the expression to cast
1014  * @param dest_type   the destination type
1015  */
1016 static expression_t *create_cast_expression(expression_t *expression,
1017                                             type_t *dest_type)
1018 {
1019         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1020
1021         cast->unary.value = expression;
1022         cast->base.type   = dest_type;
1023
1024         return cast;
1025 }
1026
1027 /**
1028  * Check if a given expression represents a null pointer constant.
1029  *
1030  * @param expression  the expression to check
1031  */
1032 static bool is_null_pointer_constant(const expression_t *expression)
1033 {
1034         /* skip void* cast */
1035         if (expression->kind == EXPR_UNARY_CAST
1036                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1037                 expression = expression->unary.value;
1038         }
1039
1040         /* TODO: not correct yet, should be any constant integer expression
1041          * which evaluates to 0 */
1042         if (expression->kind != EXPR_CONST)
1043                 return false;
1044
1045         type_t *const type = skip_typeref(expression->base.type);
1046         if (!is_type_integer(type))
1047                 return false;
1048
1049         return expression->conste.v.int_value == 0;
1050 }
1051
1052 /**
1053  * Create an implicit cast expression.
1054  *
1055  * @param expression  the expression to cast
1056  * @param dest_type   the destination type
1057  */
1058 static expression_t *create_implicit_cast(expression_t *expression,
1059                                           type_t *dest_type)
1060 {
1061         type_t *const source_type = expression->base.type;
1062
1063         if (source_type == dest_type)
1064                 return expression;
1065
1066         return create_cast_expression(expression, dest_type);
1067 }
1068
1069 typedef enum assign_error_t {
1070         ASSIGN_SUCCESS,
1071         ASSIGN_ERROR_INCOMPATIBLE,
1072         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1073         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1074         ASSIGN_WARNING_POINTER_FROM_INT,
1075         ASSIGN_WARNING_INT_FROM_POINTER
1076 } assign_error_t;
1077
1078 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1079                                 const expression_t *const right,
1080                                 const char *context,
1081                                 const source_position_t *source_position)
1082 {
1083         type_t *const orig_type_right = right->base.type;
1084         type_t *const type_left       = skip_typeref(orig_type_left);
1085         type_t *const type_right      = skip_typeref(orig_type_right);
1086
1087         switch (error) {
1088         case ASSIGN_SUCCESS:
1089                 return;
1090         case ASSIGN_ERROR_INCOMPATIBLE:
1091                 errorf(source_position,
1092                        "destination type '%T' in %s is incompatible with type '%T'",
1093                        orig_type_left, context, orig_type_right);
1094                 return;
1095
1096         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1097                 if (warning.other) {
1098                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1099                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1100
1101                         /* the left type has all qualifiers from the right type */
1102                         unsigned missing_qualifiers
1103                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1104                         warningf(source_position,
1105                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1106                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1107                 }
1108                 return;
1109         }
1110
1111         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1112                 if (warning.other) {
1113                         warningf(source_position,
1114                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1115                                         orig_type_left, context, right, orig_type_right);
1116                 }
1117                 return;
1118
1119         case ASSIGN_WARNING_POINTER_FROM_INT:
1120                 if (warning.other) {
1121                         warningf(source_position,
1122                                         "%s makes pointer '%T' from integer '%T' without a cast",
1123                                         context, orig_type_left, orig_type_right);
1124                 }
1125                 return;
1126
1127         case ASSIGN_WARNING_INT_FROM_POINTER:
1128                 if (warning.other) {
1129                         warningf(source_position,
1130                                         "%s makes integer '%T' from pointer '%T' without a cast",
1131                                         context, orig_type_left, orig_type_right);
1132                 }
1133                 return;
1134
1135         default:
1136                 panic("invalid error value");
1137         }
1138 }
1139
1140 /** Implements the rules from Â§ 6.5.16.1 */
1141 static assign_error_t semantic_assign(type_t *orig_type_left,
1142                                       const expression_t *const right)
1143 {
1144         type_t *const orig_type_right = right->base.type;
1145         type_t *const type_left       = skip_typeref(orig_type_left);
1146         type_t *const type_right      = skip_typeref(orig_type_right);
1147
1148         if (is_type_pointer(type_left)) {
1149                 if (is_null_pointer_constant(right)) {
1150                         return ASSIGN_SUCCESS;
1151                 } else if (is_type_pointer(type_right)) {
1152                         type_t *points_to_left
1153                                 = skip_typeref(type_left->pointer.points_to);
1154                         type_t *points_to_right
1155                                 = skip_typeref(type_right->pointer.points_to);
1156                         assign_error_t res = ASSIGN_SUCCESS;
1157
1158                         /* the left type has all qualifiers from the right type */
1159                         unsigned missing_qualifiers
1160                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1161                         if (missing_qualifiers != 0) {
1162                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1163                         }
1164
1165                         points_to_left  = get_unqualified_type(points_to_left);
1166                         points_to_right = get_unqualified_type(points_to_right);
1167
1168                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1169                                 return res;
1170
1171                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1172                                 /* ISO/IEC 14882:1998(E) Â§C.1.2:6 */
1173                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1174                         }
1175
1176                         if (!types_compatible(points_to_left, points_to_right)) {
1177                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1178                         }
1179
1180                         return res;
1181                 } else if (is_type_integer(type_right)) {
1182                         return ASSIGN_WARNING_POINTER_FROM_INT;
1183                 }
1184         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1185             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1186                 && is_type_pointer(type_right))) {
1187                 return ASSIGN_SUCCESS;
1188         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1189                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1190                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1191                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1192                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1193                         return ASSIGN_SUCCESS;
1194                 }
1195         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1196                 return ASSIGN_WARNING_INT_FROM_POINTER;
1197         }
1198
1199         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1200                 return ASSIGN_SUCCESS;
1201
1202         return ASSIGN_ERROR_INCOMPATIBLE;
1203 }
1204
1205 static expression_t *parse_constant_expression(void)
1206 {
1207         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1208
1209         if (!is_constant_expression(result)) {
1210                 errorf(&result->base.source_position,
1211                        "expression '%E' is not constant", result);
1212         }
1213
1214         return result;
1215 }
1216
1217 static expression_t *parse_assignment_expression(void)
1218 {
1219         return parse_sub_expression(PREC_ASSIGNMENT);
1220 }
1221
1222 static string_t parse_string_literals(void)
1223 {
1224         assert(token.type == T_STRING_LITERAL);
1225         string_t result = token.v.string;
1226
1227         next_token();
1228
1229         while (token.type == T_STRING_LITERAL) {
1230                 result = concat_strings(&result, &token.v.string);
1231                 next_token();
1232         }
1233
1234         return result;
1235 }
1236
1237 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1238         [GNU_AK_CONST]                  = "const",
1239         [GNU_AK_VOLATILE]               = "volatile",
1240         [GNU_AK_CDECL]                  = "cdecl",
1241         [GNU_AK_STDCALL]                = "stdcall",
1242         [GNU_AK_FASTCALL]               = "fastcall",
1243         [GNU_AK_DEPRECATED]             = "deprecated",
1244         [GNU_AK_NOINLINE]               = "noinline",
1245         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1246         [GNU_AK_NORETURN]               = "noreturn",
1247         [GNU_AK_NAKED]                  = "naked",
1248         [GNU_AK_PURE]                   = "pure",
1249         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1250         [GNU_AK_MALLOC]                 = "malloc",
1251         [GNU_AK_WEAK]                   = "weak",
1252         [GNU_AK_CONSTRUCTOR]            = "constructor",
1253         [GNU_AK_DESTRUCTOR]             = "destructor",
1254         [GNU_AK_NOTHROW]                = "nothrow",
1255         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1256         [GNU_AK_COMMON]                 = "common",
1257         [GNU_AK_NOCOMMON]               = "nocommon",
1258         [GNU_AK_PACKED]                 = "packed",
1259         [GNU_AK_SHARED]                 = "shared",
1260         [GNU_AK_NOTSHARED]              = "notshared",
1261         [GNU_AK_USED]                   = "used",
1262         [GNU_AK_UNUSED]                 = "unused",
1263         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1264         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1265         [GNU_AK_LONGCALL]               = "longcall",
1266         [GNU_AK_SHORTCALL]              = "shortcall",
1267         [GNU_AK_LONG_CALL]              = "long_call",
1268         [GNU_AK_SHORT_CALL]             = "short_call",
1269         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1270         [GNU_AK_INTERRUPT]              = "interrupt",
1271         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1272         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1273         [GNU_AK_NESTING]                = "nesting",
1274         [GNU_AK_NEAR]                   = "near",
1275         [GNU_AK_FAR]                    = "far",
1276         [GNU_AK_SIGNAL]                 = "signal",
1277         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1278         [GNU_AK_TINY_DATA]              = "tiny_data",
1279         [GNU_AK_SAVEALL]                = "saveall",
1280         [GNU_AK_FLATTEN]                = "flatten",
1281         [GNU_AK_SSEREGPARM]             = "sseregparm",
1282         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1283         [GNU_AK_RETURN_TWICE]           = "return_twice",
1284         [GNU_AK_MAY_ALIAS]              = "may_alias",
1285         [GNU_AK_MS_STRUCT]              = "ms_struct",
1286         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1287         [GNU_AK_DLLIMPORT]              = "dllimport",
1288         [GNU_AK_DLLEXPORT]              = "dllexport",
1289         [GNU_AK_ALIGNED]                = "aligned",
1290         [GNU_AK_ALIAS]                  = "alias",
1291         [GNU_AK_SECTION]                = "section",
1292         [GNU_AK_FORMAT]                 = "format",
1293         [GNU_AK_FORMAT_ARG]             = "format_arg",
1294         [GNU_AK_WEAKREF]                = "weakref",
1295         [GNU_AK_NONNULL]                = "nonnull",
1296         [GNU_AK_TLS_MODEL]              = "tls_model",
1297         [GNU_AK_VISIBILITY]             = "visibility",
1298         [GNU_AK_REGPARM]                = "regparm",
1299         [GNU_AK_MODE]                   = "mode",
1300         [GNU_AK_MODEL]                  = "model",
1301         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1302         [GNU_AK_SP_SWITCH]              = "sp_switch",
1303         [GNU_AK_SENTINEL]               = "sentinel"
1304 };
1305
1306 /**
1307  * compare two string, ignoring double underscores on the second.
1308  */
1309 static int strcmp_underscore(const char *s1, const char *s2)
1310 {
1311         if (s2[0] == '_' && s2[1] == '_') {
1312                 size_t len2 = strlen(s2);
1313                 size_t len1 = strlen(s1);
1314                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1315                         return strncmp(s1, s2+2, len2-4);
1316                 }
1317         }
1318
1319         return strcmp(s1, s2);
1320 }
1321
1322 /**
1323  * Allocate a new gnu temporal attribute of given kind.
1324  */
1325 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1326 {
1327         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1328         attribute->kind            = kind;
1329         attribute->next            = NULL;
1330         attribute->invalid         = false;
1331         attribute->have_arguments  = false;
1332
1333         return attribute;
1334 }
1335
1336 /**
1337  * Parse one constant expression argument of the given attribute.
1338  */
1339 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1340 {
1341         expression_t *expression;
1342         add_anchor_token(')');
1343         expression = parse_constant_expression();
1344         rem_anchor_token(')');
1345         expect(')', end_error);
1346         attribute->u.argument = fold_constant(expression);
1347         return;
1348 end_error:
1349         attribute->invalid = true;
1350 }
1351
1352 /**
1353  * Parse a list of constant expressions arguments of the given attribute.
1354  */
1355 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1356 {
1357         argument_list_t **list = &attribute->u.arguments;
1358         argument_list_t  *entry;
1359         expression_t     *expression;
1360         add_anchor_token(')');
1361         add_anchor_token(',');
1362         while (true) {
1363                 expression = parse_constant_expression();
1364                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1365                 entry->argument = fold_constant(expression);
1366                 entry->next     = NULL;
1367                 *list = entry;
1368                 list = &entry->next;
1369                 if (token.type != ',')
1370                         break;
1371                 next_token();
1372         }
1373         rem_anchor_token(',');
1374         rem_anchor_token(')');
1375         expect(')', end_error);
1376         return;
1377 end_error:
1378         attribute->invalid = true;
1379 }
1380
1381 /**
1382  * Parse one string literal argument of the given attribute.
1383  */
1384 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1385                                            string_t *string)
1386 {
1387         add_anchor_token('(');
1388         if (token.type != T_STRING_LITERAL) {
1389                 parse_error_expected("while parsing attribute directive",
1390                                      T_STRING_LITERAL, NULL);
1391                 goto end_error;
1392         }
1393         *string = parse_string_literals();
1394         rem_anchor_token('(');
1395         expect(')', end_error);
1396         return;
1397 end_error:
1398         attribute->invalid = true;
1399 }
1400
1401 /**
1402  * Parse one tls model of the given attribute.
1403  */
1404 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1405 {
1406         static const char *const tls_models[] = {
1407                 "global-dynamic",
1408                 "local-dynamic",
1409                 "initial-exec",
1410                 "local-exec"
1411         };
1412         string_t string = { NULL, 0 };
1413         parse_gnu_attribute_string_arg(attribute, &string);
1414         if (string.begin != NULL) {
1415                 for (size_t i = 0; i < 4; ++i) {
1416                         if (strcmp(tls_models[i], string.begin) == 0) {
1417                                 attribute->u.value = i;
1418                                 return;
1419                         }
1420                 }
1421                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1422         }
1423         attribute->invalid = true;
1424 }
1425
1426 /**
1427  * Parse one tls model of the given attribute.
1428  */
1429 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1430 {
1431         static const char *const visibilities[] = {
1432                 "default",
1433                 "protected",
1434                 "hidden",
1435                 "internal"
1436         };
1437         string_t string = { NULL, 0 };
1438         parse_gnu_attribute_string_arg(attribute, &string);
1439         if (string.begin != NULL) {
1440                 for (size_t i = 0; i < 4; ++i) {
1441                         if (strcmp(visibilities[i], string.begin) == 0) {
1442                                 attribute->u.value = i;
1443                                 return;
1444                         }
1445                 }
1446                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1447         }
1448         attribute->invalid = true;
1449 }
1450
1451 /**
1452  * Parse one (code) model of the given attribute.
1453  */
1454 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1455 {
1456         static const char *const visibilities[] = {
1457                 "small",
1458                 "medium",
1459                 "large"
1460         };
1461         string_t string = { NULL, 0 };
1462         parse_gnu_attribute_string_arg(attribute, &string);
1463         if (string.begin != NULL) {
1464                 for (int i = 0; i < 3; ++i) {
1465                         if (strcmp(visibilities[i], string.begin) == 0) {
1466                                 attribute->u.value = i;
1467                                 return;
1468                         }
1469                 }
1470                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1471         }
1472         attribute->invalid = true;
1473 }
1474
1475 /**
1476  * Parse one mode of the given attribute.
1477  */
1478 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1479 {
1480         /* TODO: find out what is allowed here... */
1481
1482         /* at least: byte, word, pointer, list of machine modes
1483          * __XXX___ is interpreted as XXX */
1484         add_anchor_token(')');
1485
1486         if (token.type != T_IDENTIFIER) {
1487                 expect(T_IDENTIFIER, end_error);
1488         }
1489
1490         /* This isn't really correct, the backend should provide a list of machine
1491          * specific modes (according to gcc philosophy that is...) */
1492         const char *symbol_str = token.v.symbol->string;
1493         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1494             strcmp_underscore("byte", symbol_str) == 0) {
1495                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1496         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1497                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1498         } else if (strcmp_underscore("SI",      symbol_str) == 0
1499                 || strcmp_underscore("word",    symbol_str) == 0
1500                 || strcmp_underscore("pointer", symbol_str) == 0) {
1501                 attribute->u.akind = ATOMIC_TYPE_INT;
1502         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1503                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1504         } else {
1505                 if (warning.other)
1506                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1507                 attribute->invalid = true;
1508         }
1509         next_token();
1510
1511         rem_anchor_token(')');
1512         expect(')', end_error);
1513         return;
1514 end_error:
1515         attribute->invalid = true;
1516 }
1517
1518 /**
1519  * Parse one interrupt argument of the given attribute.
1520  */
1521 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1522 {
1523         static const char *const interrupts[] = {
1524                 "IRQ",
1525                 "FIQ",
1526                 "SWI",
1527                 "ABORT",
1528                 "UNDEF"
1529         };
1530         string_t string = { NULL, 0 };
1531         parse_gnu_attribute_string_arg(attribute, &string);
1532         if (string.begin != NULL) {
1533                 for (size_t i = 0; i < 5; ++i) {
1534                         if (strcmp(interrupts[i], string.begin) == 0) {
1535                                 attribute->u.value = i;
1536                                 return;
1537                         }
1538                 }
1539                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1540         }
1541         attribute->invalid = true;
1542 }
1543
1544 /**
1545  * Parse ( identifier, const expression, const expression )
1546  */
1547 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1548 {
1549         static const char *const format_names[] = {
1550                 "printf",
1551                 "scanf",
1552                 "strftime",
1553                 "strfmon"
1554         };
1555         int i;
1556
1557         if (token.type != T_IDENTIFIER) {
1558                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1559                 goto end_error;
1560         }
1561         const char *name = token.v.symbol->string;
1562         for (i = 0; i < 4; ++i) {
1563                 if (strcmp_underscore(format_names[i], name) == 0)
1564                         break;
1565         }
1566         if (i >= 4) {
1567                 if (warning.attribute)
1568                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1569         }
1570         next_token();
1571
1572         expect(',', end_error);
1573         add_anchor_token(')');
1574         add_anchor_token(',');
1575         parse_constant_expression();
1576         rem_anchor_token(',');
1577         rem_anchor_token(')');
1578
1579         expect(',', end_error);
1580         add_anchor_token(')');
1581         parse_constant_expression();
1582         rem_anchor_token(')');
1583         expect(')', end_error);
1584         return;
1585 end_error:
1586         attribute->u.value = true;
1587 }
1588
1589 /**
1590  * Check that a given GNU attribute has no arguments.
1591  */
1592 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1593 {
1594         if (!attribute->have_arguments)
1595                 return;
1596
1597         /* should have no arguments */
1598         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1599         eat_until_matching_token('(');
1600         /* we have already consumed '(', so we stop before ')', eat it */
1601         eat(')');
1602         attribute->invalid = true;
1603 }
1604
1605 /**
1606  * Parse one GNU attribute.
1607  *
1608  * Note that attribute names can be specified WITH or WITHOUT
1609  * double underscores, ie const or __const__.
1610  *
1611  * The following attributes are parsed without arguments
1612  *  const
1613  *  volatile
1614  *  cdecl
1615  *  stdcall
1616  *  fastcall
1617  *  deprecated
1618  *  noinline
1619  *  noreturn
1620  *  naked
1621  *  pure
1622  *  always_inline
1623  *  malloc
1624  *  weak
1625  *  constructor
1626  *  destructor
1627  *  nothrow
1628  *  transparent_union
1629  *  common
1630  *  nocommon
1631  *  packed
1632  *  shared
1633  *  notshared
1634  *  used
1635  *  unused
1636  *  no_instrument_function
1637  *  warn_unused_result
1638  *  longcall
1639  *  shortcall
1640  *  long_call
1641  *  short_call
1642  *  function_vector
1643  *  interrupt_handler
1644  *  nmi_handler
1645  *  nesting
1646  *  near
1647  *  far
1648  *  signal
1649  *  eightbit_data
1650  *  tiny_data
1651  *  saveall
1652  *  flatten
1653  *  sseregparm
1654  *  externally_visible
1655  *  return_twice
1656  *  may_alias
1657  *  ms_struct
1658  *  gcc_struct
1659  *  dllimport
1660  *  dllexport
1661  *
1662  * The following attributes are parsed with arguments
1663  *  aligned( const expression )
1664  *  alias( string literal )
1665  *  section( string literal )
1666  *  format( identifier, const expression, const expression )
1667  *  format_arg( const expression )
1668  *  tls_model( string literal )
1669  *  visibility( string literal )
1670  *  regparm( const expression )
1671  *  model( string leteral )
1672  *  trap_exit( const expression )
1673  *  sp_switch( string literal )
1674  *
1675  * The following attributes might have arguments
1676  *  weak_ref( string literal )
1677  *  non_null( const expression // ',' )
1678  *  interrupt( string literal )
1679  *  sentinel( constant expression )
1680  */
1681 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1682 {
1683         gnu_attribute_t *head      = *attributes;
1684         gnu_attribute_t *last      = *attributes;
1685         decl_modifiers_t modifiers = 0;
1686         gnu_attribute_t *attribute;
1687
1688         eat(T___attribute__);
1689         expect('(', end_error);
1690         expect('(', end_error);
1691
1692         if (token.type != ')') {
1693                 /* find the end of the list */
1694                 if (last != NULL) {
1695                         while (last->next != NULL)
1696                                 last = last->next;
1697                 }
1698
1699                 /* non-empty attribute list */
1700                 while (true) {
1701                         const char *name;
1702                         if (token.type == T_const) {
1703                                 name = "const";
1704                         } else if (token.type == T_volatile) {
1705                                 name = "volatile";
1706                         } else if (token.type == T_cdecl) {
1707                                 /* __attribute__((cdecl)), WITH ms mode */
1708                                 name = "cdecl";
1709                         } else if (token.type == T_IDENTIFIER) {
1710                                 const symbol_t *sym = token.v.symbol;
1711                                 name = sym->string;
1712                         } else {
1713                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1714                                 break;
1715                         }
1716
1717                         next_token();
1718
1719                         int i;
1720                         for (i = 0; i < GNU_AK_LAST; ++i) {
1721                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1722                                         break;
1723                         }
1724                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1725
1726                         attribute = NULL;
1727                         if (kind == GNU_AK_LAST) {
1728                                 if (warning.attribute)
1729                                         warningf(HERE, "'%s' attribute directive ignored", name);
1730
1731                                 /* skip possible arguments */
1732                                 if (token.type == '(') {
1733                                         eat_until_matching_token(')');
1734                                 }
1735                         } else {
1736                                 /* check for arguments */
1737                                 attribute = allocate_gnu_attribute(kind);
1738                                 if (token.type == '(') {
1739                                         next_token();
1740                                         if (token.type == ')') {
1741                                                 /* empty args are allowed */
1742                                                 next_token();
1743                                         } else
1744                                                 attribute->have_arguments = true;
1745                                 }
1746
1747                                 switch (kind) {
1748                                 case GNU_AK_VOLATILE:
1749                                 case GNU_AK_NAKED:
1750                                 case GNU_AK_MALLOC:
1751                                 case GNU_AK_WEAK:
1752                                 case GNU_AK_COMMON:
1753                                 case GNU_AK_NOCOMMON:
1754                                 case GNU_AK_SHARED:
1755                                 case GNU_AK_NOTSHARED:
1756                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1757                                 case GNU_AK_WARN_UNUSED_RESULT:
1758                                 case GNU_AK_LONGCALL:
1759                                 case GNU_AK_SHORTCALL:
1760                                 case GNU_AK_LONG_CALL:
1761                                 case GNU_AK_SHORT_CALL:
1762                                 case GNU_AK_FUNCTION_VECTOR:
1763                                 case GNU_AK_INTERRUPT_HANDLER:
1764                                 case GNU_AK_NMI_HANDLER:
1765                                 case GNU_AK_NESTING:
1766                                 case GNU_AK_NEAR:
1767                                 case GNU_AK_FAR:
1768                                 case GNU_AK_SIGNAL:
1769                                 case GNU_AK_EIGTHBIT_DATA:
1770                                 case GNU_AK_TINY_DATA:
1771                                 case GNU_AK_SAVEALL:
1772                                 case GNU_AK_FLATTEN:
1773                                 case GNU_AK_SSEREGPARM:
1774                                 case GNU_AK_EXTERNALLY_VISIBLE:
1775                                 case GNU_AK_RETURN_TWICE:
1776                                 case GNU_AK_MAY_ALIAS:
1777                                 case GNU_AK_MS_STRUCT:
1778                                 case GNU_AK_GCC_STRUCT:
1779                                         goto no_arg;
1780
1781                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1782                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1783                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1784                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1785                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1786                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1787                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1788                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1789                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1790                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1791                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1792                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1793                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1794                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1795                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1796                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1797                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1798                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1799                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1800
1801                                 case GNU_AK_ALIGNED:
1802                                         /* __align__ may be used without an argument */
1803                                         if (attribute->have_arguments) {
1804                                                 parse_gnu_attribute_const_arg(attribute);
1805                                         }
1806                                         break;
1807
1808                                 case GNU_AK_FORMAT_ARG:
1809                                 case GNU_AK_REGPARM:
1810                                 case GNU_AK_TRAP_EXIT:
1811                                         if (!attribute->have_arguments) {
1812                                                 /* should have arguments */
1813                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1814                                                 attribute->invalid = true;
1815                                         } else
1816                                                 parse_gnu_attribute_const_arg(attribute);
1817                                         break;
1818                                 case GNU_AK_ALIAS:
1819                                 case GNU_AK_SECTION:
1820                                 case GNU_AK_SP_SWITCH:
1821                                         if (!attribute->have_arguments) {
1822                                                 /* should have arguments */
1823                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1824                                                 attribute->invalid = true;
1825                                         } else
1826                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1827                                         break;
1828                                 case GNU_AK_FORMAT:
1829                                         if (!attribute->have_arguments) {
1830                                                 /* should have arguments */
1831                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1832                                                 attribute->invalid = true;
1833                                         } else
1834                                                 parse_gnu_attribute_format_args(attribute);
1835                                         break;
1836                                 case GNU_AK_WEAKREF:
1837                                         /* may have one string argument */
1838                                         if (attribute->have_arguments)
1839                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1840                                         break;
1841                                 case GNU_AK_NONNULL:
1842                                         if (attribute->have_arguments)
1843                                                 parse_gnu_attribute_const_arg_list(attribute);
1844                                         break;
1845                                 case GNU_AK_TLS_MODEL:
1846                                         if (!attribute->have_arguments) {
1847                                                 /* should have arguments */
1848                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1849                                         } else
1850                                                 parse_gnu_attribute_tls_model_arg(attribute);
1851                                         break;
1852                                 case GNU_AK_VISIBILITY:
1853                                         if (!attribute->have_arguments) {
1854                                                 /* should have arguments */
1855                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1856                                         } else
1857                                                 parse_gnu_attribute_visibility_arg(attribute);
1858                                         break;
1859                                 case GNU_AK_MODEL:
1860                                         if (!attribute->have_arguments) {
1861                                                 /* should have arguments */
1862                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1863                                         } else {
1864                                                 parse_gnu_attribute_model_arg(attribute);
1865                                         }
1866                                         break;
1867                                 case GNU_AK_MODE:
1868                                         if (!attribute->have_arguments) {
1869                                                 /* should have arguments */
1870                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1871                                         } else {
1872                                                 parse_gnu_attribute_mode_arg(attribute);
1873                                         }
1874                                         break;
1875                                 case GNU_AK_INTERRUPT:
1876                                         /* may have one string argument */
1877                                         if (attribute->have_arguments)
1878                                                 parse_gnu_attribute_interrupt_arg(attribute);
1879                                         break;
1880                                 case GNU_AK_SENTINEL:
1881                                         /* may have one string argument */
1882                                         if (attribute->have_arguments)
1883                                                 parse_gnu_attribute_const_arg(attribute);
1884                                         break;
1885                                 case GNU_AK_LAST:
1886                                         /* already handled */
1887                                         break;
1888
1889 no_arg:
1890                                         check_no_argument(attribute, name);
1891                                 }
1892                         }
1893                         if (attribute != NULL) {
1894                                 if (last != NULL) {
1895                                         last->next = attribute;
1896                                         last       = attribute;
1897                                 } else {
1898                                         head = last = attribute;
1899                                 }
1900                         }
1901
1902                         if (token.type != ',')
1903                                 break;
1904                         next_token();
1905                 }
1906         }
1907         expect(')', end_error);
1908         expect(')', end_error);
1909 end_error:
1910         *attributes = head;
1911
1912         return modifiers;
1913 }
1914
1915 /**
1916  * Parse GNU attributes.
1917  */
1918 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1919 {
1920         decl_modifiers_t modifiers = 0;
1921
1922         while (true) {
1923                 switch (token.type) {
1924                 case T___attribute__:
1925                         modifiers |= parse_gnu_attribute(attributes);
1926                         continue;
1927
1928                 case T_asm:
1929                         next_token();
1930                         expect('(', end_error);
1931                         if (token.type != T_STRING_LITERAL) {
1932                                 parse_error_expected("while parsing assembler attribute",
1933                                                      T_STRING_LITERAL, NULL);
1934                                 eat_until_matching_token('(');
1935                                 break;
1936                         } else {
1937                                 parse_string_literals();
1938                         }
1939                         expect(')', end_error);
1940                         continue;
1941
1942                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1943                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1944                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1945
1946                 case T___thiscall:
1947                         /* TODO record modifier */
1948                         if (warning.other)
1949                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1950                         break;
1951
1952 end_error:
1953                 default: return modifiers;
1954                 }
1955
1956                 next_token();
1957         }
1958 }
1959
1960 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1961
1962 static entity_t *determine_lhs_ent(expression_t *const expr,
1963                                    entity_t *lhs_ent)
1964 {
1965         switch (expr->kind) {
1966                 case EXPR_REFERENCE: {
1967                         entity_t *const entity = expr->reference.entity;
1968                         /* we should only find variables as lvalues... */
1969                         if (entity->base.kind != ENTITY_VARIABLE
1970                                         && entity->base.kind != ENTITY_PARAMETER)
1971                                 return NULL;
1972
1973                         return entity;
1974                 }
1975
1976                 case EXPR_ARRAY_ACCESS: {
1977                         expression_t *const ref = expr->array_access.array_ref;
1978                         entity_t     *      ent = NULL;
1979                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1980                                 ent     = determine_lhs_ent(ref, lhs_ent);
1981                                 lhs_ent = ent;
1982                         } else {
1983                                 mark_vars_read(expr->select.compound, lhs_ent);
1984                         }
1985                         mark_vars_read(expr->array_access.index, lhs_ent);
1986                         return ent;
1987                 }
1988
1989                 case EXPR_SELECT: {
1990                         if (is_type_compound(skip_typeref(expr->base.type))) {
1991                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1992                         } else {
1993                                 mark_vars_read(expr->select.compound, lhs_ent);
1994                                 return NULL;
1995                         }
1996                 }
1997
1998                 case EXPR_UNARY_DEREFERENCE: {
1999                         expression_t *const val = expr->unary.value;
2000                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
2001                                 /* *&x is a NOP */
2002                                 return determine_lhs_ent(val->unary.value, lhs_ent);
2003                         } else {
2004                                 mark_vars_read(val, NULL);
2005                                 return NULL;
2006                         }
2007                 }
2008
2009                 default:
2010                         mark_vars_read(expr, NULL);
2011                         return NULL;
2012         }
2013 }
2014
2015 #define ENT_ANY ((entity_t*)-1)
2016
2017 /**
2018  * Mark declarations, which are read.  This is used to detect variables, which
2019  * are never read.
2020  * Example:
2021  * x = x + 1;
2022  *   x is not marked as "read", because it is only read to calculate its own new
2023  *   value.
2024  *
2025  * x += y; y += x;
2026  *   x and y are not detected as "not read", because multiple variables are
2027  *   involved.
2028  */
2029 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
2030 {
2031         switch (expr->kind) {
2032                 case EXPR_REFERENCE: {
2033                         entity_t *const entity = expr->reference.entity;
2034                         if (entity->kind != ENTITY_VARIABLE
2035                                         && entity->kind != ENTITY_PARAMETER)
2036                                 return;
2037
2038                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
2039                                 if (entity->kind == ENTITY_VARIABLE) {
2040                                         entity->variable.read = true;
2041                                 } else {
2042                                         entity->parameter.read = true;
2043                                 }
2044                         }
2045                         return;
2046                 }
2047
2048                 case EXPR_CALL:
2049                         // TODO respect pure/const
2050                         mark_vars_read(expr->call.function, NULL);
2051                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2052                                 mark_vars_read(arg->expression, NULL);
2053                         }
2054                         return;
2055
2056                 case EXPR_CONDITIONAL:
2057                         // TODO lhs_decl should depend on whether true/false have an effect
2058                         mark_vars_read(expr->conditional.condition, NULL);
2059                         if (expr->conditional.true_expression != NULL)
2060                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2061                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2062                         return;
2063
2064                 case EXPR_SELECT:
2065                         if (lhs_ent == ENT_ANY
2066                                         && !is_type_compound(skip_typeref(expr->base.type)))
2067                                 lhs_ent = NULL;
2068                         mark_vars_read(expr->select.compound, lhs_ent);
2069                         return;
2070
2071                 case EXPR_ARRAY_ACCESS: {
2072                         expression_t *const ref = expr->array_access.array_ref;
2073                         mark_vars_read(ref, lhs_ent);
2074                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2075                         mark_vars_read(expr->array_access.index, lhs_ent);
2076                         return;
2077                 }
2078
2079                 case EXPR_VA_ARG:
2080                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2081                         return;
2082
2083                 case EXPR_UNARY_CAST:
2084                         /* Special case: Use void cast to mark a variable as "read" */
2085                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2086                                 lhs_ent = NULL;
2087                         goto unary;
2088
2089
2090                 case EXPR_UNARY_THROW:
2091                         if (expr->unary.value == NULL)
2092                                 return;
2093                         /* FALLTHROUGH */
2094                 case EXPR_UNARY_DEREFERENCE:
2095                 case EXPR_UNARY_DELETE:
2096                 case EXPR_UNARY_DELETE_ARRAY:
2097                         if (lhs_ent == ENT_ANY)
2098                                 lhs_ent = NULL;
2099                         goto unary;
2100
2101                 case EXPR_UNARY_NEGATE:
2102                 case EXPR_UNARY_PLUS:
2103                 case EXPR_UNARY_BITWISE_NEGATE:
2104                 case EXPR_UNARY_NOT:
2105                 case EXPR_UNARY_TAKE_ADDRESS:
2106                 case EXPR_UNARY_POSTFIX_INCREMENT:
2107                 case EXPR_UNARY_POSTFIX_DECREMENT:
2108                 case EXPR_UNARY_PREFIX_INCREMENT:
2109                 case EXPR_UNARY_PREFIX_DECREMENT:
2110                 case EXPR_UNARY_CAST_IMPLICIT:
2111                 case EXPR_UNARY_ASSUME:
2112 unary:
2113                         mark_vars_read(expr->unary.value, lhs_ent);
2114                         return;
2115
2116                 case EXPR_BINARY_ADD:
2117                 case EXPR_BINARY_SUB:
2118                 case EXPR_BINARY_MUL:
2119                 case EXPR_BINARY_DIV:
2120                 case EXPR_BINARY_MOD:
2121                 case EXPR_BINARY_EQUAL:
2122                 case EXPR_BINARY_NOTEQUAL:
2123                 case EXPR_BINARY_LESS:
2124                 case EXPR_BINARY_LESSEQUAL:
2125                 case EXPR_BINARY_GREATER:
2126                 case EXPR_BINARY_GREATEREQUAL:
2127                 case EXPR_BINARY_BITWISE_AND:
2128                 case EXPR_BINARY_BITWISE_OR:
2129                 case EXPR_BINARY_BITWISE_XOR:
2130                 case EXPR_BINARY_LOGICAL_AND:
2131                 case EXPR_BINARY_LOGICAL_OR:
2132                 case EXPR_BINARY_SHIFTLEFT:
2133                 case EXPR_BINARY_SHIFTRIGHT:
2134                 case EXPR_BINARY_COMMA:
2135                 case EXPR_BINARY_ISGREATER:
2136                 case EXPR_BINARY_ISGREATEREQUAL:
2137                 case EXPR_BINARY_ISLESS:
2138                 case EXPR_BINARY_ISLESSEQUAL:
2139                 case EXPR_BINARY_ISLESSGREATER:
2140                 case EXPR_BINARY_ISUNORDERED:
2141                         mark_vars_read(expr->binary.left,  lhs_ent);
2142                         mark_vars_read(expr->binary.right, lhs_ent);
2143                         return;
2144
2145                 case EXPR_BINARY_ASSIGN:
2146                 case EXPR_BINARY_MUL_ASSIGN:
2147                 case EXPR_BINARY_DIV_ASSIGN:
2148                 case EXPR_BINARY_MOD_ASSIGN:
2149                 case EXPR_BINARY_ADD_ASSIGN:
2150                 case EXPR_BINARY_SUB_ASSIGN:
2151                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2152                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2153                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2154                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2155                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2156                         if (lhs_ent == ENT_ANY)
2157                                 lhs_ent = NULL;
2158                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2159                         mark_vars_read(expr->binary.right, lhs_ent);
2160                         return;
2161                 }
2162
2163                 case EXPR_VA_START:
2164                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2165                         return;
2166
2167                 case EXPR_UNKNOWN:
2168                 case EXPR_INVALID:
2169                 case EXPR_CONST:
2170                 case EXPR_CHARACTER_CONSTANT:
2171                 case EXPR_WIDE_CHARACTER_CONSTANT:
2172                 case EXPR_STRING_LITERAL:
2173                 case EXPR_WIDE_STRING_LITERAL:
2174                 case EXPR_COMPOUND_LITERAL: // TODO init?
2175                 case EXPR_SIZEOF:
2176                 case EXPR_CLASSIFY_TYPE:
2177                 case EXPR_ALIGNOF:
2178                 case EXPR_FUNCNAME:
2179                 case EXPR_BUILTIN_SYMBOL:
2180                 case EXPR_BUILTIN_CONSTANT_P:
2181                 case EXPR_BUILTIN_PREFETCH:
2182                 case EXPR_OFFSETOF:
2183                 case EXPR_STATEMENT: // TODO
2184                 case EXPR_LABEL_ADDRESS:
2185                 case EXPR_REFERENCE_ENUM_VALUE:
2186                         return;
2187         }
2188
2189         panic("unhandled expression");
2190 }
2191
2192 static designator_t *parse_designation(void)
2193 {
2194         designator_t *result = NULL;
2195         designator_t *last   = NULL;
2196
2197         while (true) {
2198                 designator_t *designator;
2199                 switch (token.type) {
2200                 case '[':
2201                         designator = allocate_ast_zero(sizeof(designator[0]));
2202                         designator->source_position = token.source_position;
2203                         next_token();
2204                         add_anchor_token(']');
2205                         designator->array_index = parse_constant_expression();
2206                         rem_anchor_token(']');
2207                         expect(']', end_error);
2208                         break;
2209                 case '.':
2210                         designator = allocate_ast_zero(sizeof(designator[0]));
2211                         designator->source_position = token.source_position;
2212                         next_token();
2213                         if (token.type != T_IDENTIFIER) {
2214                                 parse_error_expected("while parsing designator",
2215                                                      T_IDENTIFIER, NULL);
2216                                 return NULL;
2217                         }
2218                         designator->symbol = token.v.symbol;
2219                         next_token();
2220                         break;
2221                 default:
2222                         expect('=', end_error);
2223                         return result;
2224                 }
2225
2226                 assert(designator != NULL);
2227                 if (last != NULL) {
2228                         last->next = designator;
2229                 } else {
2230                         result = designator;
2231                 }
2232                 last = designator;
2233         }
2234 end_error:
2235         return NULL;
2236 }
2237
2238 static initializer_t *initializer_from_string(array_type_t *type,
2239                                               const string_t *const string)
2240 {
2241         /* TODO: check len vs. size of array type */
2242         (void) type;
2243
2244         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2245         initializer->string.string = *string;
2246
2247         return initializer;
2248 }
2249
2250 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2251                                                    wide_string_t *const string)
2252 {
2253         /* TODO: check len vs. size of array type */
2254         (void) type;
2255
2256         initializer_t *const initializer =
2257                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2258         initializer->wide_string.string = *string;
2259
2260         return initializer;
2261 }
2262
2263 /**
2264  * Build an initializer from a given expression.
2265  */
2266 static initializer_t *initializer_from_expression(type_t *orig_type,
2267                                                   expression_t *expression)
2268 {
2269         /* TODO check that expression is a constant expression */
2270
2271         /* Â§ 6.7.8.14/15 char array may be initialized by string literals */
2272         type_t *type           = skip_typeref(orig_type);
2273         type_t *expr_type_orig = expression->base.type;
2274         type_t *expr_type      = skip_typeref(expr_type_orig);
2275         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2276                 array_type_t *const array_type   = &type->array;
2277                 type_t       *const element_type = skip_typeref(array_type->element_type);
2278
2279                 if (element_type->kind == TYPE_ATOMIC) {
2280                         atomic_type_kind_t akind = element_type->atomic.akind;
2281                         switch (expression->kind) {
2282                                 case EXPR_STRING_LITERAL:
2283                                         if (akind == ATOMIC_TYPE_CHAR
2284                                                         || akind == ATOMIC_TYPE_SCHAR
2285                                                         || akind == ATOMIC_TYPE_UCHAR) {
2286                                                 return initializer_from_string(array_type,
2287                                                         &expression->string.value);
2288                                         }
2289
2290                                 case EXPR_WIDE_STRING_LITERAL: {
2291                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2292                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2293                                                 return initializer_from_wide_string(array_type,
2294                                                         &expression->wide_string.value);
2295                                         }
2296                                 }
2297
2298                                 default:
2299                                         break;
2300                         }
2301                 }
2302         }
2303
2304         assign_error_t error = semantic_assign(type, expression);
2305         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2306                 return NULL;
2307         report_assign_error(error, type, expression, "initializer",
2308                             &expression->base.source_position);
2309
2310         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2311 #if 0
2312         if (type->kind == TYPE_BITFIELD) {
2313                 type = type->bitfield.base_type;
2314         }
2315 #endif
2316         result->value.value = create_implicit_cast(expression, type);
2317
2318         return result;
2319 }
2320
2321 /**
2322  * Checks if a given expression can be used as an constant initializer.
2323  */
2324 static bool is_initializer_constant(const expression_t *expression)
2325 {
2326         return is_constant_expression(expression)
2327                 || is_address_constant(expression);
2328 }
2329
2330 /**
2331  * Parses an scalar initializer.
2332  *
2333  * Â§ 6.7.8.11; eat {} without warning
2334  */
2335 static initializer_t *parse_scalar_initializer(type_t *type,
2336                                                bool must_be_constant)
2337 {
2338         /* there might be extra {} hierarchies */
2339         int braces = 0;
2340         if (token.type == '{') {
2341                 if (warning.other)
2342                         warningf(HERE, "extra curly braces around scalar initializer");
2343                 do {
2344                         ++braces;
2345                         next_token();
2346                 } while (token.type == '{');
2347         }
2348
2349         expression_t *expression = parse_assignment_expression();
2350         mark_vars_read(expression, NULL);
2351         if (must_be_constant && !is_initializer_constant(expression)) {
2352                 errorf(&expression->base.source_position,
2353                        "Initialisation expression '%E' is not constant",
2354                        expression);
2355         }
2356
2357         initializer_t *initializer = initializer_from_expression(type, expression);
2358
2359         if (initializer == NULL) {
2360                 errorf(&expression->base.source_position,
2361                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2362                        expression, expression->base.type, type);
2363                 /* TODO */
2364                 return NULL;
2365         }
2366
2367         bool additional_warning_displayed = false;
2368         while (braces > 0) {
2369                 if (token.type == ',') {
2370                         next_token();
2371                 }
2372                 if (token.type != '}') {
2373                         if (!additional_warning_displayed && warning.other) {
2374                                 warningf(HERE, "additional elements in scalar initializer");
2375                                 additional_warning_displayed = true;
2376                         }
2377                 }
2378                 eat_block();
2379                 braces--;
2380         }
2381
2382         return initializer;
2383 }
2384
2385 /**
2386  * An entry in the type path.
2387  */
2388 typedef struct type_path_entry_t type_path_entry_t;
2389 struct type_path_entry_t {
2390         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2391         union {
2392                 size_t         index;          /**< For array types: the current index. */
2393                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2394         } v;
2395 };
2396
2397 /**
2398  * A type path expression a position inside compound or array types.
2399  */
2400 typedef struct type_path_t type_path_t;
2401 struct type_path_t {
2402         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2403         type_t            *top_type;     /**< type of the element the path points */
2404         size_t             max_index;    /**< largest index in outermost array */
2405 };
2406
2407 /**
2408  * Prints a type path for debugging.
2409  */
2410 static __attribute__((unused)) void debug_print_type_path(
2411                 const type_path_t *path)
2412 {
2413         size_t len = ARR_LEN(path->path);
2414
2415         for (size_t i = 0; i < len; ++i) {
2416                 const type_path_entry_t *entry = & path->path[i];
2417
2418                 type_t *type = skip_typeref(entry->type);
2419                 if (is_type_compound(type)) {
2420                         /* in gcc mode structs can have no members */
2421                         if (entry->v.compound_entry == NULL) {
2422                                 assert(i == len-1);
2423                                 continue;
2424                         }
2425                         fprintf(stderr, ".%s",
2426                                 entry->v.compound_entry->base.symbol->string);
2427                 } else if (is_type_array(type)) {
2428                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2429                 } else {
2430                         fprintf(stderr, "-INVALID-");
2431                 }
2432         }
2433         if (path->top_type != NULL) {
2434                 fprintf(stderr, "  (");
2435                 print_type(path->top_type);
2436                 fprintf(stderr, ")");
2437         }
2438 }
2439
2440 /**
2441  * Return the top type path entry, ie. in a path
2442  * (type).a.b returns the b.
2443  */
2444 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2445 {
2446         size_t len = ARR_LEN(path->path);
2447         assert(len > 0);
2448         return &path->path[len-1];
2449 }
2450
2451 /**
2452  * Enlarge the type path by an (empty) element.
2453  */
2454 static type_path_entry_t *append_to_type_path(type_path_t *path)
2455 {
2456         size_t len = ARR_LEN(path->path);
2457         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2458
2459         type_path_entry_t *result = & path->path[len];
2460         memset(result, 0, sizeof(result[0]));
2461         return result;
2462 }
2463
2464 /**
2465  * Descending into a sub-type. Enter the scope of the current top_type.
2466  */
2467 static void descend_into_subtype(type_path_t *path)
2468 {
2469         type_t *orig_top_type = path->top_type;
2470         type_t *top_type      = skip_typeref(orig_top_type);
2471
2472         type_path_entry_t *top = append_to_type_path(path);
2473         top->type              = top_type;
2474
2475         if (is_type_compound(top_type)) {
2476                 compound_t *compound  = top_type->compound.compound;
2477                 entity_t   *entry     = compound->members.entities;
2478
2479                 if (entry != NULL) {
2480                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2481                         top->v.compound_entry = &entry->declaration;
2482                         path->top_type = entry->declaration.type;
2483                 } else {
2484                         path->top_type = NULL;
2485                 }
2486         } else if (is_type_array(top_type)) {
2487                 top->v.index   = 0;
2488                 path->top_type = top_type->array.element_type;
2489         } else {
2490                 assert(!is_type_valid(top_type));
2491         }
2492 }
2493
2494 /**
2495  * Pop an entry from the given type path, ie. returning from
2496  * (type).a.b to (type).a
2497  */
2498 static void ascend_from_subtype(type_path_t *path)
2499 {
2500         type_path_entry_t *top = get_type_path_top(path);
2501
2502         path->top_type = top->type;
2503
2504         size_t len = ARR_LEN(path->path);
2505         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2506 }
2507
2508 /**
2509  * Pop entries from the given type path until the given
2510  * path level is reached.
2511  */
2512 static void ascend_to(type_path_t *path, size_t top_path_level)
2513 {
2514         size_t len = ARR_LEN(path->path);
2515
2516         while (len > top_path_level) {
2517                 ascend_from_subtype(path);
2518                 len = ARR_LEN(path->path);
2519         }
2520 }
2521
2522 static bool walk_designator(type_path_t *path, const designator_t *designator,
2523                             bool used_in_offsetof)
2524 {
2525         for (; designator != NULL; designator = designator->next) {
2526                 type_path_entry_t *top       = get_type_path_top(path);
2527                 type_t            *orig_type = top->type;
2528
2529                 type_t *type = skip_typeref(orig_type);
2530
2531                 if (designator->symbol != NULL) {
2532                         symbol_t *symbol = designator->symbol;
2533                         if (!is_type_compound(type)) {
2534                                 if (is_type_valid(type)) {
2535                                         errorf(&designator->source_position,
2536                                                "'.%Y' designator used for non-compound type '%T'",
2537                                                symbol, orig_type);
2538                                 }
2539
2540                                 top->type             = type_error_type;
2541                                 top->v.compound_entry = NULL;
2542                                 orig_type             = type_error_type;
2543                         } else {
2544                                 compound_t *compound = type->compound.compound;
2545                                 entity_t   *iter     = compound->members.entities;
2546                                 for (; iter != NULL; iter = iter->base.next) {
2547                                         if (iter->base.symbol == symbol) {
2548                                                 break;
2549                                         }
2550                                 }
2551                                 if (iter == NULL) {
2552                                         errorf(&designator->source_position,
2553                                                "'%T' has no member named '%Y'", orig_type, symbol);
2554                                         goto failed;
2555                                 }
2556                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2557                                 if (used_in_offsetof) {
2558                                         type_t *real_type = skip_typeref(iter->declaration.type);
2559                                         if (real_type->kind == TYPE_BITFIELD) {
2560                                                 errorf(&designator->source_position,
2561                                                        "offsetof designator '%Y' may not specify bitfield",
2562                                                        symbol);
2563                                                 goto failed;
2564                                         }
2565                                 }
2566
2567                                 top->type             = orig_type;
2568                                 top->v.compound_entry = &iter->declaration;
2569                                 orig_type             = iter->declaration.type;
2570                         }
2571                 } else {
2572                         expression_t *array_index = designator->array_index;
2573                         assert(designator->array_index != NULL);
2574
2575                         if (!is_type_array(type)) {
2576                                 if (is_type_valid(type)) {
2577                                         errorf(&designator->source_position,
2578                                                "[%E] designator used for non-array type '%T'",
2579                                                array_index, orig_type);
2580                                 }
2581                                 goto failed;
2582                         }
2583
2584                         long index = fold_constant(array_index);
2585                         if (!used_in_offsetof) {
2586                                 if (index < 0) {
2587                                         errorf(&designator->source_position,
2588                                                "array index [%E] must be positive", array_index);
2589                                 } else if (type->array.size_constant) {
2590                                         long array_size = type->array.size;
2591                                         if (index >= array_size) {
2592                                                 errorf(&designator->source_position,
2593                                                        "designator [%E] (%d) exceeds array size %d",
2594                                                        array_index, index, array_size);
2595                                         }
2596                                 }
2597                         }
2598
2599                         top->type    = orig_type;
2600                         top->v.index = (size_t) index;
2601                         orig_type    = type->array.element_type;
2602                 }
2603                 path->top_type = orig_type;
2604
2605                 if (designator->next != NULL) {
2606                         descend_into_subtype(path);
2607                 }
2608         }
2609         return true;
2610
2611 failed:
2612         return false;
2613 }
2614
2615 static void advance_current_object(type_path_t *path, size_t top_path_level)
2616 {
2617         type_path_entry_t *top = get_type_path_top(path);
2618
2619         type_t *type = skip_typeref(top->type);
2620         if (is_type_union(type)) {
2621                 /* in unions only the first element is initialized */
2622                 top->v.compound_entry = NULL;
2623         } else if (is_type_struct(type)) {
2624                 declaration_t *entry = top->v.compound_entry;
2625
2626                 entity_t *next_entity = entry->base.next;
2627                 if (next_entity != NULL) {
2628                         assert(is_declaration(next_entity));
2629                         entry = &next_entity->declaration;
2630                 } else {
2631                         entry = NULL;
2632                 }
2633
2634                 top->v.compound_entry = entry;
2635                 if (entry != NULL) {
2636                         path->top_type = entry->type;
2637                         return;
2638                 }
2639         } else if (is_type_array(type)) {
2640                 assert(is_type_array(type));
2641
2642                 top->v.index++;
2643
2644                 if (!type->array.size_constant || top->v.index < type->array.size) {
2645                         return;
2646                 }
2647         } else {
2648                 assert(!is_type_valid(type));
2649                 return;
2650         }
2651
2652         /* we're past the last member of the current sub-aggregate, try if we
2653          * can ascend in the type hierarchy and continue with another subobject */
2654         size_t len = ARR_LEN(path->path);
2655
2656         if (len > top_path_level) {
2657                 ascend_from_subtype(path);
2658                 advance_current_object(path, top_path_level);
2659         } else {
2660                 path->top_type = NULL;
2661         }
2662 }
2663
2664 /**
2665  * skip until token is found.
2666  */
2667 static void skip_until(int type)
2668 {
2669         while (token.type != type) {
2670                 if (token.type == T_EOF)
2671                         return;
2672                 next_token();
2673         }
2674 }
2675
2676 /**
2677  * skip any {...} blocks until a closing bracket is reached.
2678  */
2679 static void skip_initializers(void)
2680 {
2681         if (token.type == '{')
2682                 next_token();
2683
2684         while (token.type != '}') {
2685                 if (token.type == T_EOF)
2686                         return;
2687                 if (token.type == '{') {
2688                         eat_block();
2689                         continue;
2690                 }
2691                 next_token();
2692         }
2693 }
2694
2695 static initializer_t *create_empty_initializer(void)
2696 {
2697         static initializer_t empty_initializer
2698                 = { .list = { { INITIALIZER_LIST }, 0 } };
2699         return &empty_initializer;
2700 }
2701
2702 /**
2703  * Parse a part of an initialiser for a struct or union,
2704  */
2705 static initializer_t *parse_sub_initializer(type_path_t *path,
2706                 type_t *outer_type, size_t top_path_level,
2707                 parse_initializer_env_t *env)
2708 {
2709         if (token.type == '}') {
2710                 /* empty initializer */
2711                 return create_empty_initializer();
2712         }
2713
2714         type_t *orig_type = path->top_type;
2715         type_t *type      = NULL;
2716
2717         if (orig_type == NULL) {
2718                 /* We are initializing an empty compound. */
2719         } else {
2720                 type = skip_typeref(orig_type);
2721         }
2722
2723         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2724
2725         while (true) {
2726                 designator_t *designator = NULL;
2727                 if (token.type == '.' || token.type == '[') {
2728                         designator = parse_designation();
2729                         goto finish_designator;
2730                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2731                         /* GNU-style designator ("identifier: value") */
2732                         designator = allocate_ast_zero(sizeof(designator[0]));
2733                         designator->source_position = token.source_position;
2734                         designator->symbol          = token.v.symbol;
2735                         eat(T_IDENTIFIER);
2736                         eat(':');
2737
2738 finish_designator:
2739                         /* reset path to toplevel, evaluate designator from there */
2740                         ascend_to(path, top_path_level);
2741                         if (!walk_designator(path, designator, false)) {
2742                                 /* can't continue after designation error */
2743                                 goto end_error;
2744                         }
2745
2746                         initializer_t *designator_initializer
2747                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2748                         designator_initializer->designator.designator = designator;
2749                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2750
2751                         orig_type = path->top_type;
2752                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2753                 }
2754
2755                 initializer_t *sub;
2756
2757                 if (token.type == '{') {
2758                         if (type != NULL && is_type_scalar(type)) {
2759                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2760                         } else {
2761                                 eat('{');
2762                                 if (type == NULL) {
2763                                         if (env->entity != NULL) {
2764                                                 errorf(HERE,
2765                                                      "extra brace group at end of initializer for '%Y'",
2766                                                      env->entity->base.symbol);
2767                                         } else {
2768                                                 errorf(HERE, "extra brace group at end of initializer");
2769                                         }
2770                                 } else
2771                                         descend_into_subtype(path);
2772
2773                                 add_anchor_token('}');
2774                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2775                                                             env);
2776                                 rem_anchor_token('}');
2777
2778                                 if (type != NULL) {
2779                                         ascend_from_subtype(path);
2780                                         expect('}', end_error);
2781                                 } else {
2782                                         expect('}', end_error);
2783                                         goto error_parse_next;
2784                                 }
2785                         }
2786                 } else {
2787                         /* must be an expression */
2788                         expression_t *expression = parse_assignment_expression();
2789
2790                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2791                                 errorf(&expression->base.source_position,
2792                                        "Initialisation expression '%E' is not constant",
2793                                        expression);
2794                         }
2795
2796                         if (type == NULL) {
2797                                 /* we are already outside, ... */
2798                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2799                                 if (is_type_compound(outer_type_skip) &&
2800                                     !outer_type_skip->compound.compound->complete) {
2801                                         goto error_parse_next;
2802                                 }
2803                                 goto error_excess;
2804                         }
2805
2806                         /* handle { "string" } special case */
2807                         if ((expression->kind == EXPR_STRING_LITERAL
2808                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2809                                         && outer_type != NULL) {
2810                                 sub = initializer_from_expression(outer_type, expression);
2811                                 if (sub != NULL) {
2812                                         if (token.type == ',') {
2813                                                 next_token();
2814                                         }
2815                                         if (token.type != '}' && warning.other) {
2816                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2817                                                                  orig_type);
2818                                         }
2819                                         /* TODO: eat , ... */
2820                                         return sub;
2821                                 }
2822                         }
2823
2824                         /* descend into subtypes until expression matches type */
2825                         while (true) {
2826                                 orig_type = path->top_type;
2827                                 type      = skip_typeref(orig_type);
2828
2829                                 sub = initializer_from_expression(orig_type, expression);
2830                                 if (sub != NULL) {
2831                                         break;
2832                                 }
2833                                 if (!is_type_valid(type)) {
2834                                         goto end_error;
2835                                 }
2836                                 if (is_type_scalar(type)) {
2837                                         errorf(&expression->base.source_position,
2838                                                         "expression '%E' doesn't match expected type '%T'",
2839                                                         expression, orig_type);
2840                                         goto end_error;
2841                                 }
2842
2843                                 descend_into_subtype(path);
2844                         }
2845                 }
2846
2847                 /* update largest index of top array */
2848                 const type_path_entry_t *first      = &path->path[0];
2849                 type_t                  *first_type = first->type;
2850                 first_type                          = skip_typeref(first_type);
2851                 if (is_type_array(first_type)) {
2852                         size_t index = first->v.index;
2853                         if (index > path->max_index)
2854                                 path->max_index = index;
2855                 }
2856
2857                 if (type != NULL) {
2858                         /* append to initializers list */
2859                         ARR_APP1(initializer_t*, initializers, sub);
2860                 } else {
2861 error_excess:
2862                         if (warning.other) {
2863                                 if (env->entity != NULL) {
2864                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2865                                            env->entity->base.symbol);
2866                                 } else {
2867                                         warningf(HERE, "excess elements in struct initializer");
2868                                 }
2869                         }
2870                 }
2871
2872 error_parse_next:
2873                 if (token.type == '}') {
2874                         break;
2875                 }
2876                 expect(',', end_error);
2877                 if (token.type == '}') {
2878                         break;
2879                 }
2880
2881                 if (type != NULL) {
2882                         /* advance to the next declaration if we are not at the end */
2883                         advance_current_object(path, top_path_level);
2884                         orig_type = path->top_type;
2885                         if (orig_type != NULL)
2886                                 type = skip_typeref(orig_type);
2887                         else
2888                                 type = NULL;
2889                 }
2890         }
2891
2892         size_t len  = ARR_LEN(initializers);
2893         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2894         initializer_t *result = allocate_ast_zero(size);
2895         result->kind          = INITIALIZER_LIST;
2896         result->list.len      = len;
2897         memcpy(&result->list.initializers, initializers,
2898                len * sizeof(initializers[0]));
2899
2900         DEL_ARR_F(initializers);
2901         ascend_to(path, top_path_level+1);
2902
2903         return result;
2904
2905 end_error:
2906         skip_initializers();
2907         DEL_ARR_F(initializers);
2908         ascend_to(path, top_path_level+1);
2909         return NULL;
2910 }
2911
2912 /**
2913  * Parses an initializer. Parsers either a compound literal
2914  * (env->declaration == NULL) or an initializer of a declaration.
2915  */
2916 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2917 {
2918         type_t        *type      = skip_typeref(env->type);
2919         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2920         initializer_t *result;
2921
2922         if (is_type_scalar(type)) {
2923                 result = parse_scalar_initializer(type, env->must_be_constant);
2924         } else if (token.type == '{') {
2925                 eat('{');
2926
2927                 type_path_t path;
2928                 memset(&path, 0, sizeof(path));
2929                 path.top_type = env->type;
2930                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2931
2932                 descend_into_subtype(&path);
2933
2934                 add_anchor_token('}');
2935                 result = parse_sub_initializer(&path, env->type, 1, env);
2936                 rem_anchor_token('}');
2937
2938                 max_index = path.max_index;
2939                 DEL_ARR_F(path.path);
2940
2941                 expect('}', end_error);
2942         } else {
2943                 /* parse_scalar_initializer() also works in this case: we simply
2944                  * have an expression without {} around it */
2945                 result = parse_scalar_initializer(type, env->must_be_constant);
2946         }
2947
2948         /* Â§ 6.7.8 (22) array initializers for arrays with unknown size determine
2949          * the array type size */
2950         if (is_type_array(type) && type->array.size_expression == NULL
2951                         && result != NULL) {
2952                 size_t size;
2953                 switch (result->kind) {
2954                 case INITIALIZER_LIST:
2955                         assert(max_index != 0xdeadbeaf);
2956                         size = max_index + 1;
2957                         break;
2958
2959                 case INITIALIZER_STRING:
2960                         size = result->string.string.size;
2961                         break;
2962
2963                 case INITIALIZER_WIDE_STRING:
2964                         size = result->wide_string.string.size;
2965                         break;
2966
2967                 case INITIALIZER_DESIGNATOR:
2968                 case INITIALIZER_VALUE:
2969                         /* can happen for parse errors */
2970                         size = 0;
2971                         break;
2972
2973                 default:
2974                         internal_errorf(HERE, "invalid initializer type");
2975                 }
2976
2977                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2978                 cnst->base.type          = type_size_t;
2979                 cnst->conste.v.int_value = size;
2980
2981                 type_t *new_type = duplicate_type(type);
2982
2983                 new_type->array.size_expression   = cnst;
2984                 new_type->array.size_constant     = true;
2985                 new_type->array.has_implicit_size = true;
2986                 new_type->array.size              = size;
2987                 env->type = new_type;
2988         }
2989
2990         return result;
2991 end_error:
2992         return NULL;
2993 }
2994
2995 static void append_entity(scope_t *scope, entity_t *entity)
2996 {
2997         if (scope->last_entity != NULL) {
2998                 scope->last_entity->base.next = entity;
2999         } else {
3000                 scope->entities = entity;
3001         }
3002         scope->last_entity = entity;
3003 }
3004
3005
3006 static compound_t *parse_compound_type_specifier(bool is_struct)
3007 {
3008         gnu_attribute_t  *attributes = NULL;
3009         decl_modifiers_t  modifiers  = 0;
3010         if (is_struct) {
3011                 eat(T_struct);
3012         } else {
3013                 eat(T_union);
3014         }
3015
3016         symbol_t   *symbol   = NULL;
3017         compound_t *compound = NULL;
3018
3019         if (token.type == T___attribute__) {
3020                 modifiers |= parse_attributes(&attributes);
3021         }
3022
3023         if (token.type == T_IDENTIFIER) {
3024                 symbol = token.v.symbol;
3025                 next_token();
3026
3027                 namespace_tag_t const namespc =
3028                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
3029                 entity_t *entity = get_entity(symbol, namespc);
3030                 if (entity != NULL) {
3031                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
3032                         compound = &entity->compound;
3033                         if (compound->base.parent_scope != current_scope &&
3034                             (token.type == '{' || token.type == ';')) {
3035                                 /* we're in an inner scope and have a definition. Override
3036                                    existing definition in outer scope */
3037                                 compound = NULL;
3038                         } else if (compound->complete && token.type == '{') {
3039                                 assert(symbol != NULL);
3040                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3041                                        is_struct ? "struct" : "union", symbol,
3042                                        &compound->base.source_position);
3043                                 /* clear members in the hope to avoid further errors */
3044                                 compound->members.entities = NULL;
3045                         }
3046                 }
3047         } else if (token.type != '{') {
3048                 if (is_struct) {
3049                         parse_error_expected("while parsing struct type specifier",
3050                                              T_IDENTIFIER, '{', NULL);
3051                 } else {
3052                         parse_error_expected("while parsing union type specifier",
3053                                              T_IDENTIFIER, '{', NULL);
3054                 }
3055
3056                 return NULL;
3057         }
3058
3059         if (compound == NULL) {
3060                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3061                 entity_t      *entity = allocate_entity_zero(kind);
3062                 compound              = &entity->compound;
3063
3064                 compound->base.namespc =
3065                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3066                 compound->base.source_position = token.source_position;
3067                 compound->base.symbol          = symbol;
3068                 compound->base.parent_scope    = current_scope;
3069                 if (symbol != NULL) {
3070                         environment_push(entity);
3071                 }
3072                 append_entity(current_scope, entity);
3073         }
3074
3075         if (token.type == '{') {
3076                 parse_compound_type_entries(compound);
3077                 modifiers |= parse_attributes(&attributes);
3078
3079                 if (symbol == NULL) {
3080                         assert(anonymous_entity == NULL);
3081                         anonymous_entity = (entity_t*)compound;
3082                 }
3083         }
3084
3085         compound->modifiers |= modifiers;
3086         return compound;
3087 }
3088
3089 static void parse_enum_entries(type_t *const enum_type)
3090 {
3091         eat('{');
3092
3093         if (token.type == '}') {
3094                 errorf(HERE, "empty enum not allowed");
3095                 next_token();
3096                 return;
3097         }
3098
3099         add_anchor_token('}');
3100         do {
3101                 if (token.type != T_IDENTIFIER) {
3102                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3103                         eat_block();
3104                         rem_anchor_token('}');
3105                         return;
3106                 }
3107
3108                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3109                 entity->enum_value.enum_type = enum_type;
3110                 entity->base.symbol          = token.v.symbol;
3111                 entity->base.source_position = token.source_position;
3112                 next_token();
3113
3114                 if (token.type == '=') {
3115                         next_token();
3116                         expression_t *value = parse_constant_expression();
3117
3118                         value = create_implicit_cast(value, enum_type);
3119                         entity->enum_value.value = value;
3120
3121                         /* TODO semantic */
3122                 }
3123
3124                 record_entity(entity, false);
3125
3126                 if (token.type != ',')
3127                         break;
3128                 next_token();
3129         } while (token.type != '}');
3130         rem_anchor_token('}');
3131
3132         expect('}', end_error);
3133
3134 end_error:
3135         ;
3136 }
3137
3138 static type_t *parse_enum_specifier(void)
3139 {
3140         gnu_attribute_t *attributes = NULL;
3141         entity_t        *entity;
3142         symbol_t        *symbol;
3143
3144         eat(T_enum);
3145         if (token.type == T_IDENTIFIER) {
3146                 symbol = token.v.symbol;
3147                 next_token();
3148
3149                 entity = get_entity(symbol, NAMESPACE_ENUM);
3150                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3151         } else if (token.type != '{') {
3152                 parse_error_expected("while parsing enum type specifier",
3153                                      T_IDENTIFIER, '{', NULL);
3154                 return NULL;
3155         } else {
3156                 entity  = NULL;
3157                 symbol  = NULL;
3158         }
3159
3160         if (entity == NULL) {
3161                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3162                 entity->base.namespc         = NAMESPACE_ENUM;
3163                 entity->base.source_position = token.source_position;
3164                 entity->base.symbol          = symbol;
3165                 entity->base.parent_scope    = current_scope;
3166         }
3167
3168         type_t *const type = allocate_type_zero(TYPE_ENUM);
3169         type->enumt.enume  = &entity->enume;
3170
3171         if (token.type == '{') {
3172                 if (entity->enume.complete) {
3173                         errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3174                                symbol, &entity->base.source_position);
3175                 }
3176                 if (symbol != NULL) {
3177                         environment_push(entity);
3178                 }
3179                 append_entity(current_scope, entity);
3180                 entity->enume.complete = true;
3181
3182                 parse_enum_entries(type);
3183                 parse_attributes(&attributes);
3184
3185                 if (symbol == NULL) {
3186                         assert(anonymous_entity == NULL);
3187                         anonymous_entity = entity;
3188                 }
3189         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3190                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3191                        symbol);
3192         }
3193
3194         return type;
3195 }
3196
3197 /**
3198  * if a symbol is a typedef to another type, return true
3199  */
3200 static bool is_typedef_symbol(symbol_t *symbol)
3201 {
3202         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3203         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3204 }
3205
3206 static type_t *parse_typeof(void)
3207 {
3208         eat(T___typeof__);
3209
3210         type_t *type;
3211
3212         expect('(', end_error);
3213         add_anchor_token(')');
3214
3215         expression_t *expression  = NULL;
3216
3217         bool old_type_prop     = in_type_prop;
3218         bool old_gcc_extension = in_gcc_extension;
3219         in_type_prop           = true;
3220
3221         while (token.type == T___extension__) {
3222                 /* This can be a prefix to a typename or an expression. */
3223                 next_token();
3224                 in_gcc_extension = true;
3225         }
3226         switch (token.type) {
3227         case T_IDENTIFIER:
3228                 if (is_typedef_symbol(token.v.symbol)) {
3229                         type = parse_typename();
3230                 } else {
3231                         expression = parse_expression();
3232                         type       = expression->base.type;
3233                 }
3234                 break;
3235
3236         TYPENAME_START
3237                 type = parse_typename();
3238                 break;
3239
3240         default:
3241                 expression = parse_expression();
3242                 type       = expression->base.type;
3243                 break;
3244         }
3245         in_type_prop     = old_type_prop;
3246         in_gcc_extension = old_gcc_extension;
3247
3248         rem_anchor_token(')');
3249         expect(')', end_error);
3250
3251         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3252         typeof_type->typeoft.expression  = expression;
3253         typeof_type->typeoft.typeof_type = type;
3254
3255         return typeof_type;
3256 end_error:
3257         return NULL;
3258 }
3259
3260 typedef enum specifiers_t {
3261         SPECIFIER_SIGNED    = 1 << 0,
3262         SPECIFIER_UNSIGNED  = 1 << 1,
3263         SPECIFIER_LONG      = 1 << 2,
3264         SPECIFIER_INT       = 1 << 3,
3265         SPECIFIER_DOUBLE    = 1 << 4,
3266         SPECIFIER_CHAR      = 1 << 5,
3267         SPECIFIER_WCHAR_T   = 1 << 6,
3268         SPECIFIER_SHORT     = 1 << 7,
3269         SPECIFIER_LONG_LONG = 1 << 8,
3270         SPECIFIER_FLOAT     = 1 << 9,
3271         SPECIFIER_BOOL      = 1 << 10,
3272         SPECIFIER_VOID      = 1 << 11,
3273         SPECIFIER_INT8      = 1 << 12,
3274         SPECIFIER_INT16     = 1 << 13,
3275         SPECIFIER_INT32     = 1 << 14,
3276         SPECIFIER_INT64     = 1 << 15,
3277         SPECIFIER_INT128    = 1 << 16,
3278         SPECIFIER_COMPLEX   = 1 << 17,
3279         SPECIFIER_IMAGINARY = 1 << 18,
3280 } specifiers_t;
3281
3282 static type_t *create_builtin_type(symbol_t *const symbol,
3283                                    type_t *const real_type)
3284 {
3285         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3286         type->builtin.symbol    = symbol;
3287         type->builtin.real_type = real_type;
3288
3289         type_t *result = typehash_insert(type);
3290         if (type != result) {
3291                 free_type(type);
3292         }
3293
3294         return result;
3295 }
3296
3297 static type_t *get_typedef_type(symbol_t *symbol)
3298 {
3299         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3300         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3301                 return NULL;
3302
3303         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3304         type->typedeft.typedefe = &entity->typedefe;
3305
3306         return type;
3307 }
3308
3309 /**
3310  * check for the allowed MS alignment values.
3311  */
3312 static bool check_alignment_value(long long intvalue)
3313 {
3314         if (intvalue < 1 || intvalue > 8192) {
3315                 errorf(HERE, "illegal alignment value");
3316                 return false;
3317         }
3318         unsigned v = (unsigned)intvalue;
3319         for (unsigned i = 1; i <= 8192; i += i) {
3320                 if (i == v)
3321                         return true;
3322         }
3323         errorf(HERE, "alignment must be power of two");
3324         return false;
3325 }
3326
3327 #define DET_MOD(name, tag) do { \
3328         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3329         *modifiers |= tag; \
3330 } while (0)
3331
3332 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3333 {
3334         decl_modifiers_t *modifiers = &specifiers->modifiers;
3335
3336         while (true) {
3337                 if (token.type == T_restrict) {
3338                         next_token();
3339                         DET_MOD(restrict, DM_RESTRICT);
3340                         goto end_loop;
3341                 } else if (token.type != T_IDENTIFIER)
3342                         break;
3343                 symbol_t *symbol = token.v.symbol;
3344                 if (symbol == sym_align) {
3345                         next_token();
3346                         expect('(', end_error);
3347                         if (token.type != T_INTEGER)
3348                                 goto end_error;
3349                         if (check_alignment_value(token.v.intvalue)) {
3350                                 if (specifiers->alignment != 0 && warning.other)
3351                                         warningf(HERE, "align used more than once");
3352                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3353                         }
3354                         next_token();
3355                         expect(')', end_error);
3356                 } else if (symbol == sym_allocate) {
3357                         next_token();
3358                         expect('(', end_error);
3359                         if (token.type != T_IDENTIFIER)
3360                                 goto end_error;
3361                         (void)token.v.symbol;
3362                         expect(')', end_error);
3363                 } else if (symbol == sym_dllimport) {
3364                         next_token();
3365                         DET_MOD(dllimport, DM_DLLIMPORT);
3366                 } else if (symbol == sym_dllexport) {
3367                         next_token();
3368                         DET_MOD(dllexport, DM_DLLEXPORT);
3369                 } else if (symbol == sym_thread) {
3370                         next_token();
3371                         DET_MOD(thread, DM_THREAD);
3372                 } else if (symbol == sym_naked) {
3373                         next_token();
3374                         DET_MOD(naked, DM_NAKED);
3375                 } else if (symbol == sym_noinline) {
3376                         next_token();
3377                         DET_MOD(noinline, DM_NOINLINE);
3378                 } else if (symbol == sym_returns_twice) {
3379                         next_token();
3380                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3381                 } else if (symbol == sym_noreturn) {
3382                         next_token();
3383                         DET_MOD(noreturn, DM_NORETURN);
3384                 } else if (symbol == sym_nothrow) {
3385                         next_token();
3386                         DET_MOD(nothrow, DM_NOTHROW);
3387                 } else if (symbol == sym_novtable) {
3388                         next_token();
3389                         DET_MOD(novtable, DM_NOVTABLE);
3390                 } else if (symbol == sym_property) {
3391                         next_token();
3392                         expect('(', end_error);
3393                         for (;;) {
3394                                 bool is_get = false;
3395                                 if (token.type != T_IDENTIFIER)
3396                                         goto end_error;
3397                                 if (token.v.symbol == sym_get) {
3398                                         is_get = true;
3399                                 } else if (token.v.symbol == sym_put) {
3400                                 } else {
3401                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3402                                         goto end_error;
3403                                 }
3404                                 next_token();
3405                                 expect('=', end_error);
3406                                 if (token.type != T_IDENTIFIER)
3407                                         goto end_error;
3408                                 if (is_get) {
3409                                         if (specifiers->get_property_sym != NULL) {
3410                                                 errorf(HERE, "get property name already specified");
3411                                         } else {
3412                                                 specifiers->get_property_sym = token.v.symbol;
3413                                         }
3414                                 } else {
3415                                         if (specifiers->put_property_sym != NULL) {
3416                                                 errorf(HERE, "put property name already specified");
3417                                         } else {
3418                                                 specifiers->put_property_sym = token.v.symbol;
3419                                         }
3420                                 }
3421                                 next_token();
3422                                 if (token.type == ',') {
3423                                         next_token();
3424                                         continue;
3425                                 }
3426                                 break;
3427                         }
3428                         expect(')', end_error);
3429                 } else if (symbol == sym_selectany) {
3430                         next_token();
3431                         DET_MOD(selectany, DM_SELECTANY);
3432                 } else if (symbol == sym_uuid) {
3433                         next_token();
3434                         expect('(', end_error);
3435                         if (token.type != T_STRING_LITERAL)
3436                                 goto end_error;
3437                         next_token();
3438                         expect(')', end_error);
3439                 } else if (symbol == sym_deprecated) {
3440                         next_token();
3441                         if (specifiers->deprecated != 0 && warning.other)
3442                                 warningf(HERE, "deprecated used more than once");
3443                         specifiers->deprecated = true;
3444                         if (token.type == '(') {
3445                                 next_token();
3446                                 if (token.type == T_STRING_LITERAL) {
3447                                         specifiers->deprecated_string = token.v.string.begin;
3448                                         next_token();
3449                                 } else {
3450                                         errorf(HERE, "string literal expected");
3451                                 }
3452                                 expect(')', end_error);
3453                         }
3454                 } else if (symbol == sym_noalias) {
3455                         next_token();
3456                         DET_MOD(noalias, DM_NOALIAS);
3457                 } else {
3458                         if (warning.other)
3459                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3460                         next_token();
3461                         if (token.type == '(')
3462                                 skip_until(')');
3463                 }
3464 end_loop:
3465                 if (token.type == ',')
3466                         next_token();
3467         }
3468 end_error:
3469         return;
3470 }
3471
3472 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3473 {
3474         entity_t *entity             = allocate_entity_zero(kind);
3475         entity->base.source_position = *HERE;
3476         entity->base.symbol          = symbol;
3477         if (is_declaration(entity)) {
3478                 entity->declaration.type     = type_error_type;
3479                 entity->declaration.implicit = true;
3480         } else if (kind == ENTITY_TYPEDEF) {
3481                 entity->typedefe.type    = type_error_type;
3482                 entity->typedefe.builtin = true;
3483         }
3484         record_entity(entity, false);
3485         return entity;
3486 }
3487
3488 static void parse_microsoft_based(based_spec_t *based_spec)
3489 {
3490         if (token.type != T_IDENTIFIER) {
3491                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3492                 return;
3493         }
3494         symbol_t *symbol = token.v.symbol;
3495         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3496
3497         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3498                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3499                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3500         } else {
3501                 variable_t *variable = &entity->variable;
3502
3503                 if (based_spec->base_variable != NULL) {
3504                         errorf(HERE, "__based type qualifier specified more than once");
3505                 }
3506                 based_spec->source_position = token.source_position;
3507                 based_spec->base_variable   = variable;
3508
3509                 type_t *const type = variable->base.type;
3510
3511                 if (is_type_valid(type)) {
3512                         if (! is_type_pointer(skip_typeref(type))) {
3513                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3514                         }
3515                         if (variable->base.base.parent_scope != file_scope) {
3516                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3517                         }
3518                 }
3519         }
3520         next_token();
3521 }
3522
3523 /**
3524  * Finish the construction of a struct type by calculating
3525  * its size, offsets, alignment.
3526  */
3527 static void finish_struct_type(compound_type_t *type)
3528 {
3529         assert(type->compound != NULL);
3530
3531         compound_t *compound = type->compound;
3532         if (!compound->complete)
3533                 return;
3534
3535         il_size_t      size           = 0;
3536         il_size_t      offset;
3537         il_alignment_t alignment      = 1;
3538         bool           need_pad       = false;
3539
3540         entity_t *entry = compound->members.entities;
3541         for (; entry != NULL; entry = entry->base.next) {
3542                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3543                         continue;
3544
3545                 type_t *m_type = skip_typeref(entry->declaration.type);
3546                 if (! is_type_valid(m_type)) {
3547                         /* simply ignore errors here */
3548                         continue;
3549                 }
3550                 il_alignment_t m_alignment = m_type->base.alignment;
3551                 if (m_alignment > alignment)
3552                         alignment = m_alignment;
3553
3554                 offset = (size + m_alignment - 1) & -m_alignment;
3555
3556                 if (offset > size)
3557                         need_pad = true;
3558                 entry->compound_member.offset = offset;
3559                 size = offset + m_type->base.size;
3560         }
3561         if (type->base.alignment != 0) {
3562                 alignment = type->base.alignment;
3563         }
3564
3565         offset = (size + alignment - 1) & -alignment;
3566         if (offset > size)
3567                 need_pad = true;
3568
3569         if (need_pad) {
3570                 if (warning.padded) {
3571                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3572                 }
3573         } else {
3574                 if (compound->modifiers & DM_PACKED && warning.packed) {
3575                         warningf(&compound->base.source_position,
3576                                         "superfluous packed attribute on '%T'", type);
3577                 }
3578         }
3579
3580         type->base.size      = offset;
3581         type->base.alignment = alignment;
3582 }
3583
3584 /**
3585  * Finish the construction of an union type by calculating
3586  * its size and alignment.
3587  */
3588 static void finish_union_type(compound_type_t *type)
3589 {
3590         assert(type->compound != NULL);
3591
3592         compound_t *compound = type->compound;
3593         if (! compound->complete)
3594                 return;
3595
3596         il_size_t      size      = 0;
3597         il_alignment_t alignment = 1;
3598
3599         entity_t *entry = compound->members.entities;
3600         for (; entry != NULL; entry = entry->base.next) {
3601                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3602                         continue;
3603
3604                 type_t *m_type = skip_typeref(entry->declaration.type);
3605                 if (! is_type_valid(m_type))
3606                         continue;
3607
3608                 entry->compound_member.offset = 0;
3609                 if (m_type->base.size > size)
3610                         size = m_type->base.size;
3611                 if (m_type->base.alignment > alignment)
3612                         alignment = m_type->base.alignment;
3613         }
3614         if (type->base.alignment != 0) {
3615                 alignment = type->base.alignment;
3616         }
3617         size = (size + alignment - 1) & -alignment;
3618         type->base.size      = size;
3619         type->base.alignment = alignment;
3620 }
3621
3622 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3623 {
3624         type_t            *type              = NULL;
3625         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3626         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3627         unsigned           type_specifiers   = 0;
3628         bool               newtype           = false;
3629         bool               saw_error         = false;
3630         bool               old_gcc_extension = in_gcc_extension;
3631
3632         specifiers->source_position = token.source_position;
3633
3634         while (true) {
3635                 specifiers->modifiers
3636                         |= parse_attributes(&specifiers->gnu_attributes);
3637                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3638                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3639
3640                 switch (token.type) {
3641                 /* storage class */
3642 #define MATCH_STORAGE_CLASS(token, class)                                  \
3643                 case token:                                                        \
3644                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3645                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3646                         }                                                              \
3647                         specifiers->storage_class = class;                             \
3648                         if (specifiers->thread_local)                                  \
3649                                 goto check_thread_storage_class;                           \
3650                         next_token();                                                  \
3651                         break;
3652
3653                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3654                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3655                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3656                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3657                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3658
3659                 case T__declspec:
3660                         next_token();
3661                         expect('(', end_error);
3662                         add_anchor_token(')');
3663                         parse_microsoft_extended_decl_modifier(specifiers);
3664                         rem_anchor_token(')');
3665                         expect(')', end_error);
3666                         break;
3667
3668                 case T___thread:
3669                         if (specifiers->thread_local) {
3670                                 errorf(HERE, "duplicate '__thread'");
3671                         } else {
3672                                 specifiers->thread_local = true;
3673 check_thread_storage_class:
3674                                 switch (specifiers->storage_class) {
3675                                         case STORAGE_CLASS_EXTERN:
3676                                         case STORAGE_CLASS_NONE:
3677                                         case STORAGE_CLASS_STATIC:
3678                                                 break;
3679
3680                                                 char const* wrong;
3681                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3682                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3683                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3684 wrong_thread_stoarge_class:
3685                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3686                                                 break;
3687                                 }
3688                         }
3689                         next_token();
3690                         break;
3691
3692                 /* type qualifiers */
3693 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3694                 case token:                                                     \
3695                         qualifiers |= qualifier;                                    \
3696                         next_token();                                               \
3697                         break
3698
3699                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3700                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3701                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3702                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3703                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3704                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3705                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3706                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3707
3708                 case T___extension__:
3709                         next_token();
3710                         in_gcc_extension = true;
3711                         break;
3712
3713                 /* type specifiers */
3714 #define MATCH_SPECIFIER(token, specifier, name)                         \
3715                 case token:                                                     \
3716                         if (type_specifiers & specifier) {                           \
3717                                 errorf(HERE, "multiple " name " type specifiers given"); \
3718                         } else {                                                    \
3719                                 type_specifiers |= specifier;                           \
3720                         }                                                           \
3721                         next_token();                                               \
3722                         break
3723
3724                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3725                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3726                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3727                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3728                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3729                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3730                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3731                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3732                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3733                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3734                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3735                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3736                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3737                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3738                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3739                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3740                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3741                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3742
3743                 case T__forceinline:
3744                         /* only in microsoft mode */
3745                         specifiers->modifiers |= DM_FORCEINLINE;
3746                         /* FALLTHROUGH */
3747
3748                 case T_inline:
3749                         next_token();
3750                         specifiers->is_inline = true;
3751                         break;
3752
3753                 case T_long:
3754                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3755                                 errorf(HERE, "multiple type specifiers given");
3756                         } else if (type_specifiers & SPECIFIER_LONG) {
3757                                 type_specifiers |= SPECIFIER_LONG_LONG;
3758                         } else {
3759                                 type_specifiers |= SPECIFIER_LONG;
3760                         }
3761                         next_token();
3762                         break;
3763
3764                 case T_struct: {
3765                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3766
3767                         type->compound.compound = parse_compound_type_specifier(true);
3768                         finish_struct_type(&type->compound);
3769                         break;
3770                 }
3771                 case T_union: {
3772                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3773                         type->compound.compound = parse_compound_type_specifier(false);
3774                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3775                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3776                         finish_union_type(&type->compound);
3777                         break;
3778                 }
3779                 case T_enum:
3780                         type = parse_enum_specifier();
3781                         break;
3782                 case T___typeof__:
3783                         type = parse_typeof();
3784                         break;
3785                 case T___builtin_va_list:
3786                         type = duplicate_type(type_valist);
3787                         next_token();
3788                         break;
3789
3790                 case T_IDENTIFIER: {
3791                         /* only parse identifier if we haven't found a type yet */
3792                         if (type != NULL || type_specifiers != 0) {
3793                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3794                                  * declaration, so it doesn't generate errors about expecting '(' or
3795                                  * '{' later on. */
3796                                 switch (look_ahead(1)->type) {
3797                                         STORAGE_CLASSES
3798                                         TYPE_SPECIFIERS
3799                                         case T_const:
3800                                         case T_restrict:
3801                                         case T_volatile:
3802                                         case T_inline:
3803                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3804                                         case T_IDENTIFIER:
3805                                         case '&':
3806                                         case '*':
3807                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3808                                                 next_token();
3809                                                 continue;
3810
3811                                         default:
3812                                                 goto finish_specifiers;
3813                                 }
3814                         }
3815
3816                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3817                         if (typedef_type == NULL) {
3818                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3819                                  * declaration, so it doesn't generate 'implicit int' followed by more
3820                                  * errors later on. */
3821                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3822                                 switch (la1_type) {
3823                                         DECLARATION_START
3824                                         case T_IDENTIFIER:
3825                                         case '&':
3826                                         case '*': {
3827                                                 errorf(HERE, "%K does not name a type", &token);
3828
3829                                                 entity_t *entity =
3830                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3831
3832                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3833                                                 type->typedeft.typedefe = &entity->typedefe;
3834
3835                                                 next_token();
3836                                                 saw_error = true;
3837                                                 if (la1_type == '&' || la1_type == '*')
3838                                                         goto finish_specifiers;
3839                                                 continue;
3840                                         }
3841
3842                                         default:
3843                                                 goto finish_specifiers;
3844                                 }
3845                         }
3846
3847                         next_token();
3848                         type = typedef_type;
3849                         break;
3850                 }
3851
3852                 /* function specifier */
3853                 default:
3854                         goto finish_specifiers;
3855                 }
3856         }
3857
3858 finish_specifiers:
3859         in_gcc_extension = old_gcc_extension;
3860
3861         if (type == NULL || (saw_error && type_specifiers != 0)) {
3862                 atomic_type_kind_t atomic_type;
3863
3864                 /* match valid basic types */
3865                 switch (type_specifiers) {
3866                 case SPECIFIER_VOID:
3867                         atomic_type = ATOMIC_TYPE_VOID;
3868                         break;
3869                 case SPECIFIER_WCHAR_T:
3870                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3871                         break;
3872                 case SPECIFIER_CHAR:
3873                         atomic_type = ATOMIC_TYPE_CHAR;
3874                         break;
3875                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3876                         atomic_type = ATOMIC_TYPE_SCHAR;
3877                         break;
3878                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3879                         atomic_type = ATOMIC_TYPE_UCHAR;
3880                         break;
3881                 case SPECIFIER_SHORT:
3882                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3883                 case SPECIFIER_SHORT | SPECIFIER_INT:
3884                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3885                         atomic_type = ATOMIC_TYPE_SHORT;
3886                         break;
3887                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3888                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3889                         atomic_type = ATOMIC_TYPE_USHORT;
3890                         break;
3891                 case SPECIFIER_INT:
3892                 case SPECIFIER_SIGNED:
3893                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3894                         atomic_type = ATOMIC_TYPE_INT;
3895                         break;
3896                 case SPECIFIER_UNSIGNED:
3897                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3898                         atomic_type = ATOMIC_TYPE_UINT;
3899                         break;
3900                 case SPECIFIER_LONG:
3901                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3902                 case SPECIFIER_LONG | SPECIFIER_INT:
3903                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3904                         atomic_type = ATOMIC_TYPE_LONG;
3905                         break;
3906                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3907                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3908                         atomic_type = ATOMIC_TYPE_ULONG;
3909                         break;
3910
3911                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3912                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3913                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3914                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3915                         | SPECIFIER_INT:
3916                         atomic_type = ATOMIC_TYPE_LONGLONG;
3917                         goto warn_about_long_long;
3918
3919                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3920                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3921                         | SPECIFIER_INT:
3922                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3923 warn_about_long_long:
3924                         if (warning.long_long) {
3925                                 warningf(&specifiers->source_position,
3926                                          "ISO C90 does not support 'long long'");
3927                         }
3928                         break;
3929
3930                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3931                         atomic_type = unsigned_int8_type_kind;
3932                         break;
3933
3934                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3935                         atomic_type = unsigned_int16_type_kind;
3936                         break;
3937
3938                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3939                         atomic_type = unsigned_int32_type_kind;
3940                         break;
3941
3942                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3943                         atomic_type = unsigned_int64_type_kind;
3944                         break;
3945
3946                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3947                         atomic_type = unsigned_int128_type_kind;
3948                         break;
3949
3950                 case SPECIFIER_INT8:
3951                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3952                         atomic_type = int8_type_kind;
3953                         break;
3954
3955                 case SPECIFIER_INT16:
3956                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3957                         atomic_type = int16_type_kind;
3958                         break;
3959
3960                 case SPECIFIER_INT32:
3961                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3962                         atomic_type = int32_type_kind;
3963                         break;
3964
3965                 case SPECIFIER_INT64:
3966                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3967                         atomic_type = int64_type_kind;
3968                         break;
3969
3970                 case SPECIFIER_INT128:
3971                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3972                         atomic_type = int128_type_kind;
3973                         break;
3974
3975                 case SPECIFIER_FLOAT:
3976                         atomic_type = ATOMIC_TYPE_FLOAT;
3977                         break;
3978                 case SPECIFIER_DOUBLE:
3979                         atomic_type = ATOMIC_TYPE_DOUBLE;
3980                         break;
3981                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3982                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3983                         break;
3984                 case SPECIFIER_BOOL:
3985                         atomic_type = ATOMIC_TYPE_BOOL;
3986                         break;
3987                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3988                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3989                         atomic_type = ATOMIC_TYPE_FLOAT;
3990                         break;
3991                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3992                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3993                         atomic_type = ATOMIC_TYPE_DOUBLE;
3994                         break;
3995                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3996                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3997                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3998                         break;
3999                 default:
4000                         /* invalid specifier combination, give an error message */
4001                         if (type_specifiers == 0) {
4002                                 if (saw_error)
4003                                         goto end_error;
4004
4005                                 /* ISO/IEC 14882:1998(E) Â§C.1.5:4 */
4006                                 if (!(c_mode & _CXX) && !strict_mode) {
4007                                         if (warning.implicit_int) {
4008                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4009                                         }
4010                                         atomic_type = ATOMIC_TYPE_INT;
4011                                         break;
4012                                 } else {
4013                                         errorf(HERE, "no type specifiers given in declaration");
4014                                 }
4015                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4016                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4017                                 errorf(HERE, "signed and unsigned specifiers given");
4018                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4019                                 errorf(HERE, "only integer types can be signed or unsigned");
4020                         } else {
4021                                 errorf(HERE, "multiple datatypes in declaration");
4022                         }
4023                         goto end_error;
4024                 }
4025
4026                 if (type_specifiers & SPECIFIER_COMPLEX) {
4027                         type                = allocate_type_zero(TYPE_COMPLEX);
4028                         type->complex.akind = atomic_type;
4029                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4030                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4031                         type->imaginary.akind = atomic_type;
4032                 } else {
4033                         type               = allocate_type_zero(TYPE_ATOMIC);
4034                         type->atomic.akind = atomic_type;
4035                 }
4036                 newtype = true;
4037         } else if (type_specifiers != 0) {
4038                 errorf(HERE, "multiple datatypes in declaration");
4039         }
4040
4041         /* FIXME: check type qualifiers here */
4042
4043         type->base.qualifiers = qualifiers;
4044         type->base.modifiers  = modifiers;
4045
4046         type_t *result = typehash_insert(type);
4047         if (newtype && result != type) {
4048                 free_type(type);
4049         }
4050
4051         specifiers->type = result;
4052         return;
4053
4054 end_error:
4055         specifiers->type = type_error_type;
4056         return;
4057 }
4058
4059 static type_qualifiers_t parse_type_qualifiers(void)
4060 {
4061         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4062
4063         while (true) {
4064                 switch (token.type) {
4065                 /* type qualifiers */
4066                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4067                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4068                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4069                 /* microsoft extended type modifiers */
4070                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4071                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4072                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4073                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4074                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4075
4076                 default:
4077                         return qualifiers;
4078                 }
4079         }
4080 }
4081
4082 /**
4083  * Parses an K&R identifier list
4084  */
4085 static void parse_identifier_list(scope_t *scope)
4086 {
4087         do {
4088                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4089                 entity->base.source_position = token.source_position;
4090                 entity->base.namespc         = NAMESPACE_NORMAL;
4091                 entity->base.symbol          = token.v.symbol;
4092                 /* a K&R parameter has no type, yet */
4093                 next_token();
4094
4095                 if (scope != NULL)
4096                         append_entity(scope, entity);
4097
4098                 if (token.type != ',') {
4099                         break;
4100                 }
4101                 next_token();
4102         } while (token.type == T_IDENTIFIER);
4103 }
4104
4105 static entity_t *parse_parameter(void)
4106 {
4107         declaration_specifiers_t specifiers;
4108         memset(&specifiers, 0, sizeof(specifiers));
4109
4110         parse_declaration_specifiers(&specifiers);
4111
4112         entity_t *entity = parse_declarator(&specifiers,
4113                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4114         anonymous_entity = NULL;
4115         return entity;
4116 }
4117
4118 static void semantic_parameter_incomplete(const entity_t *entity)
4119 {
4120         assert(entity->kind == ENTITY_PARAMETER);
4121
4122         /* Â§6.7.5.3:4  After adjustment, the parameters in a parameter type
4123          *             list in a function declarator that is part of a
4124          *             definition of that function shall not have
4125          *             incomplete type. */
4126         type_t *type = skip_typeref(entity->declaration.type);
4127         if (is_type_incomplete(type)) {
4128                 errorf(&entity->base.source_position,
4129                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4130                        entity->declaration.type);
4131         }
4132 }
4133
4134 /**
4135  * Parses function type parameters (and optionally creates variable_t entities
4136  * for them in a scope)
4137  */
4138 static void parse_parameters(function_type_t *type, scope_t *scope)
4139 {
4140         eat('(');
4141         add_anchor_token(')');
4142         int saved_comma_state = save_and_reset_anchor_state(',');
4143
4144         if (token.type == T_IDENTIFIER &&
4145             !is_typedef_symbol(token.v.symbol)) {
4146                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4147                 if (la1_type == ',' || la1_type == ')') {
4148                         type->kr_style_parameters    = true;
4149                         type->unspecified_parameters = true;
4150                         parse_identifier_list(scope);
4151                         goto parameters_finished;
4152                 }
4153         }
4154
4155         if (token.type == ')') {
4156                 /* ISO/IEC 14882:1998(E) Â§C.1.6:1 */
4157                 if (!(c_mode & _CXX))
4158                         type->unspecified_parameters = true;
4159                 goto parameters_finished;
4160         }
4161
4162         function_parameter_t *parameter;
4163         function_parameter_t *last_parameter = NULL;
4164
4165         while (true) {
4166                 switch (token.type) {
4167                 case T_DOTDOTDOT:
4168                         next_token();
4169                         type->variadic = true;
4170                         goto parameters_finished;
4171
4172                 case T_IDENTIFIER:
4173                 case T___extension__:
4174                 DECLARATION_START
4175                 {
4176                         entity_t *entity = parse_parameter();
4177                         if (entity->kind == ENTITY_TYPEDEF) {
4178                                 errorf(&entity->base.source_position,
4179                                        "typedef not allowed as function parameter");
4180                                 break;
4181                         }
4182                         assert(is_declaration(entity));
4183
4184                         /* func(void) is not a parameter */
4185                         if (last_parameter == NULL
4186                                         && token.type == ')'
4187                                         && entity->base.symbol == NULL
4188                                         && skip_typeref(entity->declaration.type) == type_void) {
4189                                 goto parameters_finished;
4190                         }
4191                         semantic_parameter_incomplete(entity);
4192
4193                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4194                         memset(parameter, 0, sizeof(parameter[0]));
4195                         parameter->type = entity->declaration.type;
4196
4197                         if (scope != NULL) {
4198                                 append_entity(scope, entity);
4199                         }
4200
4201                         if (last_parameter != NULL) {
4202                                 last_parameter->next = parameter;
4203                         } else {
4204                                 type->parameters = parameter;
4205                         }
4206                         last_parameter   = parameter;
4207                         break;
4208                 }
4209
4210                 default:
4211                         goto parameters_finished;
4212                 }
4213                 if (token.type != ',') {
4214                         goto parameters_finished;
4215                 }
4216                 next_token();
4217         }
4218
4219
4220 parameters_finished:
4221         rem_anchor_token(')');
4222         expect(')', end_error);
4223
4224 end_error:
4225         restore_anchor_state(',', saved_comma_state);
4226 }
4227
4228 typedef enum construct_type_kind_t {
4229         CONSTRUCT_INVALID,
4230         CONSTRUCT_POINTER,
4231         CONSTRUCT_REFERENCE,
4232         CONSTRUCT_FUNCTION,
4233         CONSTRUCT_ARRAY
4234 } construct_type_kind_t;
4235
4236 typedef struct construct_type_t construct_type_t;
4237 struct construct_type_t {
4238         construct_type_kind_t  kind;
4239         construct_type_t      *next;
4240 };
4241
4242 typedef struct parsed_pointer_t parsed_pointer_t;
4243 struct parsed_pointer_t {
4244         construct_type_t  construct_type;
4245         type_qualifiers_t type_qualifiers;
4246         variable_t        *base_variable;  /**< MS __based extension. */
4247 };
4248
4249 typedef struct parsed_reference_t parsed_reference_t;
4250 struct parsed_reference_t {
4251         construct_type_t construct_type;
4252 };
4253
4254 typedef struct construct_function_type_t construct_function_type_t;
4255 struct construct_function_type_t {
4256         construct_type_t  construct_type;
4257         type_t           *function_type;
4258 };
4259
4260 typedef struct parsed_array_t parsed_array_t;
4261 struct parsed_array_t {
4262         construct_type_t  construct_type;
4263         type_qualifiers_t type_qualifiers;
4264         bool              is_static;
4265         bool              is_variable;
4266         expression_t     *size;
4267 };
4268
4269 typedef struct construct_base_type_t construct_base_type_t;
4270 struct construct_base_type_t {
4271         construct_type_t  construct_type;
4272         type_t           *type;
4273 };
4274
4275 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4276 {
4277         eat('*');
4278
4279         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4280         memset(pointer, 0, sizeof(pointer[0]));
4281         pointer->construct_type.kind = CONSTRUCT_POINTER;
4282         pointer->type_qualifiers     = parse_type_qualifiers();
4283         pointer->base_variable       = base_variable;
4284
4285         return &pointer->construct_type;
4286 }
4287
4288 static construct_type_t *parse_reference_declarator(void)
4289 {
4290         eat('&');
4291
4292         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4293         memset(reference, 0, sizeof(reference[0]));
4294         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4295
4296         return (construct_type_t*)reference;
4297 }
4298
4299 static construct_type_t *parse_array_declarator(void)
4300 {
4301         eat('[');
4302         add_anchor_token(']');
4303
4304         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4305         memset(array, 0, sizeof(array[0]));
4306         array->construct_type.kind = CONSTRUCT_ARRAY;
4307
4308         if (token.type == T_static) {
4309                 array->is_static = true;
4310                 next_token();
4311         }
4312
4313         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4314         if (type_qualifiers != 0) {
4315                 if (token.type == T_static) {
4316                         array->is_static = true;
4317                         next_token();
4318                 }
4319         }
4320         array->type_qualifiers = type_qualifiers;
4321
4322         if (token.type == '*' && look_ahead(1)->type == ']') {
4323                 array->is_variable = true;
4324                 next_token();
4325         } else if (token.type != ']') {
4326                 array->size = parse_assignment_expression();
4327         }
4328
4329         rem_anchor_token(']');
4330         expect(']', end_error);
4331
4332 end_error:
4333         return &array->construct_type;
4334 }
4335
4336 static construct_type_t *parse_function_declarator(scope_t *scope,
4337                                                    decl_modifiers_t modifiers)
4338 {
4339         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4340         function_type_t *ftype = &type->function;
4341
4342         ftype->linkage = current_linkage;
4343
4344         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4345                 case DM_NONE:     break;
4346                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4347                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4348                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4349                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4350
4351                 default:
4352                         errorf(HERE, "multiple calling conventions in declaration");
4353                         break;
4354         }
4355
4356         parse_parameters(ftype, scope);
4357
4358         construct_function_type_t *construct_function_type =
4359                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4360         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4361         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4362         construct_function_type->function_type       = type;
4363
4364         return &construct_function_type->construct_type;
4365 }
4366
4367 typedef struct parse_declarator_env_t {
4368         decl_modifiers_t   modifiers;
4369         symbol_t          *symbol;
4370         source_position_t  source_position;
4371         scope_t            parameters;
4372 } parse_declarator_env_t;
4373
4374 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4375                 bool may_be_abstract)
4376 {
4377         /* construct a single linked list of construct_type_t's which describe
4378          * how to construct the final declarator type */
4379         construct_type_t *first      = NULL;
4380         construct_type_t *last       = NULL;
4381         gnu_attribute_t  *attributes = NULL;
4382
4383         decl_modifiers_t modifiers = parse_attributes(&attributes);
4384
4385         /* MS __based extension */
4386         based_spec_t base_spec;
4387         base_spec.base_variable = NULL;
4388
4389         for (;;) {
4390                 construct_type_t *type;
4391                 switch (token.type) {
4392                         case '&':
4393                                 if (!(c_mode & _CXX))
4394                                         errorf(HERE, "references are only available for C++");
4395                                 if (base_spec.base_variable != NULL && warning.other) {
4396                                         warningf(&base_spec.source_position,
4397                                                  "__based does not precede a pointer operator, ignored");
4398                                 }
4399                                 type = parse_reference_declarator();
4400                                 /* consumed */
4401                                 base_spec.base_variable = NULL;
4402                                 break;
4403
4404                         case '*':
4405                                 type = parse_pointer_declarator(base_spec.base_variable);
4406                                 /* consumed */
4407                                 base_spec.base_variable = NULL;
4408                                 break;
4409
4410                         case T__based:
4411                                 next_token();
4412                                 expect('(', end_error);
4413                                 add_anchor_token(')');
4414                                 parse_microsoft_based(&base_spec);
4415                                 rem_anchor_token(')');
4416                                 expect(')', end_error);
4417                                 continue;
4418
4419                         default:
4420                                 goto ptr_operator_end;
4421                 }
4422
4423                 if (last == NULL) {
4424                         first = type;
4425                         last  = type;
4426                 } else {
4427                         last->next = type;
4428                         last       = type;
4429                 }
4430
4431                 /* TODO: find out if this is correct */
4432                 modifiers |= parse_attributes(&attributes);
4433         }
4434 ptr_operator_end:
4435         if (base_spec.base_variable != NULL && warning.other) {
4436                 warningf(&base_spec.source_position,
4437                          "__based does not precede a pointer operator, ignored");
4438         }
4439
4440         if (env != NULL) {
4441                 modifiers      |= env->modifiers;
4442                 env->modifiers  = modifiers;
4443         }
4444
4445         construct_type_t *inner_types = NULL;
4446
4447         switch (token.type) {
4448         case T_IDENTIFIER:
4449                 if (env == NULL) {
4450                         errorf(HERE, "no identifier expected in typename");
4451                 } else {
4452                         env->symbol          = token.v.symbol;
4453                         env->source_position = token.source_position;
4454                 }
4455                 next_token();
4456                 break;
4457         case '(':
4458                 /* Â§6.7.6:2 footnote 126:  Empty parentheses in a type name are
4459                  * interpreted as ``function with no parameter specification'', rather
4460                  * than redundant parentheses around the omitted identifier. */
4461                 if (look_ahead(1)->type != ')') {
4462                         next_token();
4463                         add_anchor_token(')');
4464                         inner_types = parse_inner_declarator(env, may_be_abstract);
4465                         if (inner_types != NULL) {
4466                                 /* All later declarators only modify the return type */
4467                                 env = NULL;
4468                         }
4469                         rem_anchor_token(')');
4470                         expect(')', end_error);
4471                 }
4472                 break;
4473         default:
4474                 if (may_be_abstract)
4475                         break;
4476                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4477                 eat_until_anchor();
4478                 return NULL;
4479         }
4480
4481         construct_type_t *p = last;
4482
4483         while (true) {
4484                 construct_type_t *type;
4485                 switch (token.type) {
4486                 case '(': {
4487                         scope_t *scope = NULL;
4488                         if (env != NULL)
4489                                 scope = &env->parameters;
4490
4491                         type = parse_function_declarator(scope, modifiers);
4492                         break;
4493                 }
4494                 case '[':
4495                         type = parse_array_declarator();
4496                         break;
4497                 default:
4498                         goto declarator_finished;
4499                 }
4500
4501                 /* insert in the middle of the list (behind p) */
4502                 if (p != NULL) {
4503                         type->next = p->next;
4504                         p->next    = type;
4505                 } else {
4506                         type->next = first;
4507                         first      = type;
4508                 }
4509                 if (last == p) {
4510                         last = type;
4511                 }
4512         }
4513
4514 declarator_finished:
4515         /* append inner_types at the end of the list, we don't to set last anymore
4516          * as it's not needed anymore */
4517         if (last == NULL) {
4518                 assert(first == NULL);
4519                 first = inner_types;
4520         } else {
4521                 last->next = inner_types;
4522         }
4523
4524         return first;
4525 end_error:
4526         return NULL;
4527 }
4528
4529 static void parse_declaration_attributes(entity_t *entity)
4530 {
4531         gnu_attribute_t  *attributes = NULL;
4532         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4533
4534         if (entity == NULL)
4535                 return;
4536
4537         type_t *type;
4538         if (entity->kind == ENTITY_TYPEDEF) {
4539                 modifiers |= entity->typedefe.modifiers;
4540                 type       = entity->typedefe.type;
4541         } else {
4542                 assert(is_declaration(entity));
4543                 modifiers |= entity->declaration.modifiers;
4544                 type       = entity->declaration.type;
4545         }
4546         if (type == NULL)
4547                 return;
4548
4549         /* handle these strange/stupid mode attributes */
4550         gnu_attribute_t *attribute = attributes;
4551         for ( ; attribute != NULL; attribute = attribute->next) {
4552                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4553                         continue;
4554
4555                 atomic_type_kind_t  akind = attribute->u.akind;
4556                 if (!is_type_signed(type)) {
4557                         switch (akind) {
4558                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4559                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4560                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4561                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4562                         default:
4563                                 panic("invalid akind in mode attribute");
4564                         }
4565                 } else {
4566                         switch (akind) {
4567                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4568                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4569                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4570                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4571                         default:
4572                                 panic("invalid akind in mode attribute");
4573                         }
4574                 }
4575
4576                 type = make_atomic_type(akind, type->base.qualifiers);
4577         }
4578
4579         type_modifiers_t type_modifiers = type->base.modifiers;
4580         if (modifiers & DM_TRANSPARENT_UNION)
4581                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4582
4583         if (type->base.modifiers != type_modifiers) {
4584                 type_t *copy = duplicate_type(type);
4585                 copy->base.modifiers = type_modifiers;
4586
4587                 type = typehash_insert(copy);
4588                 if (type != copy) {
4589                         obstack_free(type_obst, copy);
4590                 }
4591         }
4592
4593         if (entity->kind == ENTITY_TYPEDEF) {
4594                 entity->typedefe.type      = type;
4595                 entity->typedefe.modifiers = modifiers;
4596         } else {
4597                 entity->declaration.type      = type;
4598                 entity->declaration.modifiers = modifiers;
4599         }
4600 }
4601
4602 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4603 {
4604         construct_type_t *iter = construct_list;
4605         for (; iter != NULL; iter = iter->next) {
4606                 switch (iter->kind) {
4607                 case CONSTRUCT_INVALID:
4608                         internal_errorf(HERE, "invalid type construction found");
4609                 case CONSTRUCT_FUNCTION: {
4610                         construct_function_type_t *construct_function_type
4611                                 = (construct_function_type_t*) iter;
4612
4613                         type_t *function_type = construct_function_type->function_type;
4614
4615                         function_type->function.return_type = type;
4616
4617                         type_t *skipped_return_type = skip_typeref(type);
4618                         /* Â§6.7.5.3(1) */
4619                         if (is_type_function(skipped_return_type)) {
4620                                 errorf(HERE, "function returning function is not allowed");
4621                         } else if (is_type_array(skipped_return_type)) {
4622                                 errorf(HERE, "function returning array is not allowed");
4623                         } else {
4624                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4625                                         warningf(HERE,
4626                                                 "type qualifiers in return type of function type are meaningless");
4627                                 }
4628                         }
4629
4630                         type = function_type;
4631                         break;
4632                 }
4633
4634                 case CONSTRUCT_POINTER: {
4635                         if (is_type_reference(skip_typeref(type)))
4636                                 errorf(HERE, "cannot declare a pointer to reference");
4637
4638                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4639                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4640                         continue;
4641                 }
4642
4643                 case CONSTRUCT_REFERENCE:
4644                         if (is_type_reference(skip_typeref(type)))
4645                                 errorf(HERE, "cannot declare a reference to reference");
4646
4647                         type = make_reference_type(type);
4648                         continue;
4649
4650                 case CONSTRUCT_ARRAY: {
4651                         if (is_type_reference(skip_typeref(type)))
4652                                 errorf(HERE, "cannot declare an array of references");
4653
4654                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4655                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4656
4657                         expression_t *size_expression = parsed_array->size;
4658                         if (size_expression != NULL) {
4659                                 size_expression
4660                                         = create_implicit_cast(size_expression, type_size_t);
4661                         }
4662
4663                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4664                         array_type->array.element_type    = type;
4665                         array_type->array.is_static       = parsed_array->is_static;
4666                         array_type->array.is_variable     = parsed_array->is_variable;
4667                         array_type->array.size_expression = size_expression;
4668
4669                         if (size_expression != NULL) {
4670                                 if (is_constant_expression(size_expression)) {
4671                                         array_type->array.size_constant = true;
4672                                         array_type->array.size
4673                                                 = fold_constant(size_expression);
4674                                 } else {
4675                                         array_type->array.is_vla = true;
4676                                 }
4677                         }
4678
4679                         type_t *skipped_type = skip_typeref(type);
4680                         /* Â§6.7.5.2(1) */
4681                         if (is_type_incomplete(skipped_type)) {
4682                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4683                         } else if (is_type_function(skipped_type)) {
4684                                 errorf(HERE, "array of functions is not allowed");
4685                         }
4686                         type = array_type;
4687                         break;
4688                 }
4689                 }
4690
4691                 type_t *hashed_type = typehash_insert(type);
4692                 if (hashed_type != type) {
4693                         /* the function type was constructed earlier freeing it here will
4694                          * destroy other types... */
4695                         if (iter->kind != CONSTRUCT_FUNCTION) {
4696                                 free_type(type);
4697                         }
4698                         type = hashed_type;
4699                 }
4700         }
4701
4702         return type;
4703 }
4704
4705 static type_t *automatic_type_conversion(type_t *orig_type);
4706
4707 static type_t *semantic_parameter(const source_position_t *pos,
4708                                   type_t *type,
4709                                   const declaration_specifiers_t *specifiers,
4710                                   symbol_t *symbol)
4711 {
4712         /* Â§6.7.5.3:7  A declaration of a parameter as ``array of type''
4713          *             shall be adjusted to ``qualified pointer to type'',
4714          *             [...]
4715          * Â§6.7.5.3:8  A declaration of a parameter as ``function returning
4716          *             type'' shall be adjusted to ``pointer to function
4717          *             returning type'', as in 6.3.2.1. */
4718         type = automatic_type_conversion(type);
4719
4720         if (specifiers->is_inline && is_type_valid(type)) {
4721                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4722         }
4723
4724         /* Â§6.9.1:6  The declarations in the declaration list shall contain
4725          *           no storage-class specifier other than register and no
4726          *           initializations. */
4727         if (specifiers->thread_local || (
4728                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4729                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4730            ) {
4731                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4732         }
4733
4734         /* delay test for incomplete type, because we might have (void)
4735          * which is legal but incomplete... */
4736
4737         return type;
4738 }
4739
4740 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4741                                   declarator_flags_t flags)
4742 {
4743         parse_declarator_env_t env;
4744         memset(&env, 0, sizeof(env));
4745         env.modifiers = specifiers->modifiers;
4746
4747         construct_type_t *construct_type =
4748                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4749         type_t           *orig_type      =
4750                 construct_declarator_type(construct_type, specifiers->type);
4751         type_t           *type           = skip_typeref(orig_type);
4752
4753         if (construct_type != NULL) {
4754                 obstack_free(&temp_obst, construct_type);
4755         }
4756
4757         entity_t *entity;
4758         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4759                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4760                 entity->base.symbol          = env.symbol;
4761                 entity->base.source_position = env.source_position;
4762                 entity->typedefe.type        = orig_type;
4763
4764                 if (anonymous_entity != NULL) {
4765                         if (is_type_compound(type)) {
4766                                 assert(anonymous_entity->compound.alias == NULL);
4767                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4768                                        anonymous_entity->kind == ENTITY_UNION);
4769                                 anonymous_entity->compound.alias = entity;
4770                                 anonymous_entity = NULL;
4771                         } else if (is_type_enum(type)) {
4772                                 assert(anonymous_entity->enume.alias == NULL);
4773                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4774                                 anonymous_entity->enume.alias = entity;
4775                                 anonymous_entity = NULL;
4776                         }
4777                 }
4778         } else {
4779                 /* create a declaration type entity */
4780                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4781                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4782
4783                         if (specifiers->is_inline && is_type_valid(type)) {
4784                                 errorf(&env.source_position,
4785                                                 "compound member '%Y' declared 'inline'", env.symbol);
4786                         }
4787
4788                         if (specifiers->thread_local ||
4789                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4790                                 errorf(&env.source_position,
4791                                            "compound member '%Y' must have no storage class",
4792                                            env.symbol);
4793                         }
4794                 } else if (flags & DECL_IS_PARAMETER) {
4795                         orig_type = semantic_parameter(&env.source_position, orig_type,
4796                                                        specifiers, env.symbol);
4797
4798                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4799                 } else if (is_type_function(type)) {
4800                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4801
4802                         entity->function.is_inline  = specifiers->is_inline;
4803                         entity->function.parameters = env.parameters;
4804
4805                         if (specifiers->thread_local || (
4806                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4807                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4808                                         specifiers->storage_class != STORAGE_CLASS_STATIC)
4809                            ) {
4810                                 errorf(&env.source_position,
4811                                            "invalid storage class for function '%Y'", env.symbol);
4812                         }
4813                 } else {
4814                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4815
4816                         entity->variable.get_property_sym = specifiers->get_property_sym;
4817                         entity->variable.put_property_sym = specifiers->put_property_sym;
4818                         if (specifiers->alignment != 0) {
4819                                 /* TODO: add checks here */
4820                                 entity->variable.alignment = specifiers->alignment;
4821                         }
4822
4823                         if (specifiers->is_inline && is_type_valid(type)) {
4824                                 errorf(&env.source_position,
4825                                            "variable '%Y' declared 'inline'", env.symbol);
4826                         }
4827
4828                         entity->variable.thread_local = specifiers->thread_local;
4829
4830                         bool invalid_storage_class = false;
4831                         if (current_scope == file_scope) {
4832                                 if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4833                                                 specifiers->storage_class != STORAGE_CLASS_NONE   &&
4834                                                 specifiers->storage_class != STORAGE_CLASS_STATIC) {
4835                                         invalid_storage_class = true;
4836                                 }
4837                         } else {
4838                                 if (specifiers->thread_local &&
4839                                                 specifiers->storage_class == STORAGE_CLASS_NONE) {
4840                                         invalid_storage_class = true;
4841                                 }
4842                         }
4843                         if (invalid_storage_class) {
4844                                 errorf(&env.source_position,
4845                                                 "invalid storage class for variable '%Y'", env.symbol);
4846                         }
4847                 }
4848
4849                 entity->base.source_position          = env.source_position;
4850                 entity->base.symbol                   = env.symbol;
4851                 entity->base.namespc                  = NAMESPACE_NORMAL;
4852                 entity->declaration.type              = orig_type;
4853                 entity->declaration.modifiers         = env.modifiers;
4854                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4855
4856                 storage_class_t storage_class = specifiers->storage_class;
4857                 entity->declaration.declared_storage_class = storage_class;
4858
4859                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4860                         storage_class = STORAGE_CLASS_AUTO;
4861                 entity->declaration.storage_class = storage_class;
4862         }
4863
4864         parse_declaration_attributes(entity);
4865
4866         return entity;
4867 }
4868
4869 static type_t *parse_abstract_declarator(type_t *base_type)
4870 {
4871         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4872
4873         type_t *result = construct_declarator_type(construct_type, base_type);
4874         if (construct_type != NULL) {
4875                 obstack_free(&temp_obst, construct_type);
4876         }
4877
4878         return result;
4879 }
4880
4881 /**
4882  * Check if the declaration of main is suspicious.  main should be a
4883  * function with external linkage, returning int, taking either zero
4884  * arguments, two, or three arguments of appropriate types, ie.
4885  *
4886  * int main([ int argc, char **argv [, char **env ] ]).
4887  *
4888  * @param decl    the declaration to check
4889  * @param type    the function type of the declaration
4890  */
4891 static void check_type_of_main(const entity_t *entity)
4892 {
4893         const source_position_t *pos = &entity->base.source_position;
4894         if (entity->kind != ENTITY_FUNCTION) {
4895                 warningf(pos, "'main' is not a function");
4896                 return;
4897         }
4898
4899         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4900                 warningf(pos, "'main' is normally a non-static function");
4901         }
4902
4903         type_t *type = skip_typeref(entity->declaration.type);
4904         assert(is_type_function(type));
4905
4906         function_type_t *func_type = &type->function;
4907         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4908                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4909                          func_type->return_type);
4910         }
4911         const function_parameter_t *parm = func_type->parameters;
4912         if (parm != NULL) {
4913                 type_t *const first_type = parm->type;
4914                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4915                         warningf(pos,
4916                                  "first argument of 'main' should be 'int', but is '%T'",
4917                                  first_type);
4918                 }
4919                 parm = parm->next;
4920                 if (parm != NULL) {
4921                         type_t *const second_type = parm->type;
4922                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4923                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4924                         }
4925                         parm = parm->next;
4926                         if (parm != NULL) {
4927                                 type_t *const third_type = parm->type;
4928                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4929                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4930                                 }
4931                                 parm = parm->next;
4932                                 if (parm != NULL)
4933                                         goto warn_arg_count;
4934                         }
4935                 } else {
4936 warn_arg_count:
4937                         warningf(pos, "'main' takes only zero, two or three arguments");
4938                 }
4939         }
4940 }
4941
4942 /**
4943  * Check if a symbol is the equal to "main".
4944  */
4945 static bool is_sym_main(const symbol_t *const sym)
4946 {
4947         return strcmp(sym->string, "main") == 0;
4948 }
4949
4950 static void error_redefined_as_different_kind(const source_position_t *pos,
4951                 const entity_t *old, entity_kind_t new_kind)
4952 {
4953         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4954                get_entity_kind_name(old->kind), old->base.symbol,
4955                get_entity_kind_name(new_kind), &old->base.source_position);
4956 }
4957
4958 /**
4959  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4960  * for various problems that occur for multiple definitions
4961  */
4962 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4963 {
4964         const symbol_t *const    symbol  = entity->base.symbol;
4965         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4966         const source_position_t *pos     = &entity->base.source_position;
4967
4968         /* can happen in error cases */
4969         if (symbol == NULL)
4970                 return entity;
4971
4972         entity_t *previous_entity = get_entity(symbol, namespc);
4973         /* pushing the same entity twice will break the stack structure */
4974         assert(previous_entity != entity);
4975
4976         if (entity->kind == ENTITY_FUNCTION) {
4977                 type_t *const orig_type = entity->declaration.type;
4978                 type_t *const type      = skip_typeref(orig_type);
4979
4980                 assert(is_type_function(type));
4981                 if (type->function.unspecified_parameters &&
4982                                 warning.strict_prototypes &&
4983                                 previous_entity == NULL) {
4984                         warningf(pos, "function declaration '%#T' is not a prototype",
4985                                          orig_type, symbol);
4986                 }
4987
4988                 if (warning.main && current_scope == file_scope
4989                                 && is_sym_main(symbol)) {
4990                         check_type_of_main(entity);
4991                 }
4992         }
4993
4994         if (is_declaration(entity) &&
4995                         warning.nested_externs &&
4996                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4997                         current_scope != file_scope) {
4998                 warningf(pos, "nested extern declaration of '%#T'",
4999                          entity->declaration.type, symbol);
5000         }
5001
5002         if (previous_entity != NULL &&
5003                         previous_entity->base.parent_scope == &current_function->parameters &&
5004                         previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5005                 assert(previous_entity->kind == ENTITY_PARAMETER);
5006                 errorf(pos,
5007                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5008                                          entity->declaration.type, symbol,
5009                                          previous_entity->declaration.type, symbol,
5010                                          &previous_entity->base.source_position);
5011                 goto finish;
5012         }
5013
5014         if (previous_entity != NULL &&
5015                         previous_entity->base.parent_scope == current_scope) {
5016                 if (previous_entity->kind != entity->kind) {
5017                         error_redefined_as_different_kind(pos, previous_entity,
5018                                                           entity->kind);
5019                         goto finish;
5020                 }
5021                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5022                         errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5023                                    symbol, &previous_entity->base.source_position);
5024                         goto finish;
5025                 }
5026                 if (previous_entity->kind == ENTITY_TYPEDEF) {
5027                         /* TODO: C++ allows this for exactly the same type */
5028                         errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5029                                symbol, &previous_entity->base.source_position);
5030                         goto finish;
5031                 }
5032
5033                 /* at this point we should have only VARIABLES or FUNCTIONS */
5034                 assert(is_declaration(previous_entity) && is_declaration(entity));
5035
5036                 declaration_t *const prev_decl = &previous_entity->declaration;
5037                 declaration_t *const decl      = &entity->declaration;
5038
5039                 /* can happen for K&R style declarations */
5040                 if (prev_decl->type       == NULL             &&
5041                                 previous_entity->kind == ENTITY_PARAMETER &&
5042                                 entity->kind          == ENTITY_PARAMETER) {
5043                         prev_decl->type                   = decl->type;
5044                         prev_decl->storage_class          = decl->storage_class;
5045                         prev_decl->declared_storage_class = decl->declared_storage_class;
5046                         prev_decl->modifiers              = decl->modifiers;
5047                         prev_decl->deprecated_string      = decl->deprecated_string;
5048                         return previous_entity;
5049                 }
5050
5051                 type_t *const orig_type = decl->type;
5052                 assert(orig_type != NULL);
5053                 type_t *const type      = skip_typeref(orig_type);
5054                 type_t *      prev_type = skip_typeref(prev_decl->type);
5055
5056                 if (!types_compatible(type, prev_type)) {
5057                         errorf(pos,
5058                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
5059                                    orig_type, symbol, prev_decl->type, symbol,
5060                                    &previous_entity->base.source_position);
5061                 } else {
5062                         unsigned old_storage_class = prev_decl->storage_class;
5063                         if (warning.redundant_decls               &&
5064                                         is_definition                     &&
5065                                         !prev_decl->used                  &&
5066                                         !(prev_decl->modifiers & DM_USED) &&
5067                                         prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5068                                 warningf(&previous_entity->base.source_position,
5069                                          "unnecessary static forward declaration for '%#T'",
5070                                          prev_decl->type, symbol);
5071                         }
5072
5073                         unsigned new_storage_class = decl->storage_class;
5074                         if (is_type_incomplete(prev_type)) {
5075                                 prev_decl->type = type;
5076                                 prev_type       = type;
5077                         }
5078
5079                         /* pretend no storage class means extern for function
5080                          * declarations (except if the previous declaration is neither
5081                          * none nor extern) */
5082                         if (entity->kind == ENTITY_FUNCTION) {
5083                                 if (prev_type->function.unspecified_parameters) {
5084                                         prev_decl->type = type;
5085                                         prev_type       = type;
5086                                 }
5087
5088                                 switch (old_storage_class) {
5089                                 case STORAGE_CLASS_NONE:
5090                                         old_storage_class = STORAGE_CLASS_EXTERN;
5091                                         /* FALLTHROUGH */
5092
5093                                 case STORAGE_CLASS_EXTERN:
5094                                         if (is_definition) {
5095                                                 if (warning.missing_prototypes &&
5096                                                     prev_type->function.unspecified_parameters &&
5097                                                     !is_sym_main(symbol)) {
5098                                                         warningf(pos, "no previous prototype for '%#T'",
5099                                                                          orig_type, symbol);
5100                                                 }
5101                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5102                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5103                                         }
5104                                         break;
5105
5106                                 default:
5107                                         break;
5108                                 }
5109                         }
5110
5111                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5112                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5113 warn_redundant_declaration:
5114                                 if (!is_definition           &&
5115                                     warning.redundant_decls  &&
5116                                     is_type_valid(prev_type) &&
5117                                     strcmp(previous_entity->base.source_position.input_name,
5118                                            "<builtin>") != 0) {
5119                                         warningf(pos,
5120                                                  "redundant declaration for '%Y' (declared %P)",
5121                                                  symbol, &previous_entity->base.source_position);
5122                                 }
5123                         } else if (current_function == NULL) {
5124                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5125                                     new_storage_class == STORAGE_CLASS_STATIC) {
5126                                         errorf(pos,
5127                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5128                                                symbol, &previous_entity->base.source_position);
5129                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5130                                         prev_decl->storage_class          = STORAGE_CLASS_NONE;
5131                                         prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5132                                 } else {
5133                                         /* ISO/IEC 14882:1998(E) Â§C.1.2:1 */
5134                                         if (c_mode & _CXX)
5135                                                 goto error_redeclaration;
5136                                         goto warn_redundant_declaration;
5137                                 }
5138                         } else if (is_type_valid(prev_type)) {
5139                                 if (old_storage_class == new_storage_class) {
5140 error_redeclaration:
5141                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5142                                                symbol, &previous_entity->base.source_position);
5143                                 } else {
5144                                         errorf(pos,
5145                                                "redeclaration of '%Y' with different linkage (declared %P)",
5146                                                symbol, &previous_entity->base.source_position);
5147                                 }
5148                         }
5149                 }
5150
5151                 prev_decl->modifiers |= decl->modifiers;
5152                 if (entity->kind == ENTITY_FUNCTION) {
5153                         previous_entity->function.is_inline |= entity->function.is_inline;
5154                 }
5155                 return previous_entity;
5156         }
5157
5158         if (entity->kind == ENTITY_FUNCTION) {
5159                 if (is_definition &&
5160                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5161                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5162                                 warningf(pos, "no previous prototype for '%#T'",
5163                                          entity->declaration.type, symbol);
5164                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5165                                 warningf(pos, "no previous declaration for '%#T'",
5166                                          entity->declaration.type, symbol);
5167                         }
5168                 }
5169         } else if (warning.missing_declarations &&
5170                         entity->kind == ENTITY_VARIABLE &&
5171                         current_scope == file_scope) {
5172                 declaration_t *declaration = &entity->declaration;
5173                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5174                         warningf(pos, "no previous declaration for '%#T'",
5175                                  declaration->type, symbol);
5176                 }
5177         }
5178
5179 finish:
5180         assert(entity->base.parent_scope == NULL);
5181         assert(current_scope != NULL);
5182
5183         entity->base.parent_scope = current_scope;
5184         entity->base.namespc      = NAMESPACE_NORMAL;
5185         environment_push(entity);
5186         append_entity(current_scope, entity);
5187
5188         return entity;
5189 }
5190
5191 static void parser_error_multiple_definition(entity_t *entity,
5192                 const source_position_t *source_position)
5193 {
5194         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5195                entity->base.symbol, &entity->base.source_position);
5196 }
5197
5198 static bool is_declaration_specifier(const token_t *token,
5199                                      bool only_specifiers_qualifiers)
5200 {
5201         switch (token->type) {
5202                 TYPE_SPECIFIERS
5203                 TYPE_QUALIFIERS
5204                         return true;
5205                 case T_IDENTIFIER:
5206                         return is_typedef_symbol(token->v.symbol);
5207
5208                 case T___extension__:
5209                 STORAGE_CLASSES
5210                         return !only_specifiers_qualifiers;
5211
5212                 default:
5213                         return false;
5214         }
5215 }
5216
5217 static void parse_init_declarator_rest(entity_t *entity)
5218 {
5219         assert(is_declaration(entity));
5220         declaration_t *const declaration = &entity->declaration;
5221
5222         eat('=');
5223
5224         type_t *orig_type = declaration->type;
5225         type_t *type      = skip_typeref(orig_type);
5226
5227         if (entity->kind == ENTITY_VARIABLE
5228                         && entity->variable.initializer != NULL) {
5229                 parser_error_multiple_definition(entity, HERE);
5230         }
5231
5232         bool must_be_constant = false;
5233         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5234             entity->base.parent_scope  == file_scope) {
5235                 must_be_constant = true;
5236         }
5237
5238         if (is_type_function(type)) {
5239                 errorf(&entity->base.source_position,
5240                        "function '%#T' is initialized like a variable",
5241                        orig_type, entity->base.symbol);
5242                 orig_type = type_error_type;
5243         }
5244
5245         parse_initializer_env_t env;
5246         env.type             = orig_type;
5247         env.must_be_constant = must_be_constant;
5248         env.entity           = entity;
5249         current_init_decl    = entity;
5250
5251         initializer_t *initializer = parse_initializer(&env);
5252         current_init_decl = NULL;
5253
5254         if (entity->kind == ENTITY_VARIABLE) {
5255                 /* Â§ 6.7.5 (22)  array initializers for arrays with unknown size
5256                  * determine the array type size */
5257                 declaration->type            = env.type;
5258                 entity->variable.initializer = initializer;
5259         }
5260 }
5261
5262 /* parse rest of a declaration without any declarator */
5263 static void parse_anonymous_declaration_rest(
5264                 const declaration_specifiers_t *specifiers)
5265 {
5266         eat(';');
5267         anonymous_entity = NULL;
5268
5269         if (warning.other) {
5270                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5271                                 specifiers->thread_local) {
5272                         warningf(&specifiers->source_position,
5273                                  "useless storage class in empty declaration");
5274                 }
5275
5276                 type_t *type = specifiers->type;
5277                 switch (type->kind) {
5278                         case TYPE_COMPOUND_STRUCT:
5279                         case TYPE_COMPOUND_UNION: {
5280                                 if (type->compound.compound->base.symbol == NULL) {
5281                                         warningf(&specifiers->source_position,
5282                                                  "unnamed struct/union that defines no instances");
5283                                 }
5284                                 break;
5285                         }
5286
5287                         case TYPE_ENUM:
5288                                 break;
5289
5290                         default:
5291                                 warningf(&specifiers->source_position, "empty declaration");
5292                                 break;
5293                 }
5294         }
5295 }
5296
5297 static void check_variable_type_complete(entity_t *ent)
5298 {
5299         if (ent->kind != ENTITY_VARIABLE)
5300                 return;
5301
5302         /* Â§6.7:7  If an identifier for an object is declared with no linkage, the
5303          *         type for the object shall be complete [...] */
5304         declaration_t *decl = &ent->declaration;
5305         if (decl->storage_class != STORAGE_CLASS_NONE)
5306                 return;
5307
5308         type_t *const orig_type = decl->type;
5309         type_t *const type      = skip_typeref(orig_type);
5310         if (!is_type_incomplete(type))
5311                 return;
5312
5313         /* GCC allows global arrays without size and assigns them a length of one,
5314          * if no different declaration follows */
5315         if (is_type_array(type) &&
5316                         c_mode & _GNUC      &&
5317                         ent->base.parent_scope == file_scope) {
5318                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5319                 return;
5320         }
5321
5322         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5323                         orig_type, ent->base.symbol);
5324 }
5325
5326
5327 static void parse_declaration_rest(entity_t *ndeclaration,
5328                 const declaration_specifiers_t *specifiers,
5329                 parsed_declaration_func         finished_declaration,
5330                 declarator_flags_t              flags)
5331 {
5332         add_anchor_token(';');
5333         add_anchor_token(',');
5334         while (true) {
5335                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5336
5337                 if (token.type == '=') {
5338                         parse_init_declarator_rest(entity);
5339                 } else if (entity->kind == ENTITY_VARIABLE) {
5340                         /* ISO/IEC 14882:1998(E) Â§8.5.3:3  The initializer can be omitted
5341                          * [...] where the extern specifier is explicitly used. */
5342                         declaration_t *decl = &entity->declaration;
5343                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5344                                 type_t *type = decl->type;
5345                                 if (is_type_reference(skip_typeref(type))) {
5346                                         errorf(&entity->base.source_position,
5347                                                         "reference '%#T' must be initialized",
5348                                                         type, entity->base.symbol);
5349                                 }
5350                         }
5351                 }
5352
5353                 check_variable_type_complete(entity);
5354
5355                 if (token.type != ',')
5356                         break;
5357                 eat(',');
5358
5359                 add_anchor_token('=');
5360                 ndeclaration = parse_declarator(specifiers, flags);
5361                 rem_anchor_token('=');
5362         }
5363         expect(';', end_error);
5364
5365 end_error:
5366         anonymous_entity = NULL;
5367         rem_anchor_token(';');
5368         rem_anchor_token(',');
5369 }
5370
5371 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5372 {
5373         symbol_t *symbol = entity->base.symbol;
5374         if (symbol == NULL) {
5375                 errorf(HERE, "anonymous declaration not valid as function parameter");
5376                 return entity;
5377         }
5378
5379         assert(entity->base.namespc == NAMESPACE_NORMAL);
5380         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5381         if (previous_entity == NULL
5382                         || previous_entity->base.parent_scope != current_scope) {
5383                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5384                        symbol);
5385                 return entity;
5386         }
5387
5388         if (is_definition) {
5389                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5390         }
5391
5392         return record_entity(entity, false);
5393 }
5394
5395 static void parse_declaration(parsed_declaration_func finished_declaration,
5396                               declarator_flags_t      flags)
5397 {
5398         declaration_specifiers_t specifiers;
5399         memset(&specifiers, 0, sizeof(specifiers));
5400
5401         add_anchor_token(';');
5402         parse_declaration_specifiers(&specifiers);
5403         rem_anchor_token(';');
5404
5405         if (token.type == ';') {
5406                 parse_anonymous_declaration_rest(&specifiers);
5407         } else {
5408                 entity_t *entity = parse_declarator(&specifiers, flags);
5409                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5410         }
5411 }
5412
5413 static type_t *get_default_promoted_type(type_t *orig_type)
5414 {
5415         type_t *result = orig_type;
5416
5417         type_t *type = skip_typeref(orig_type);
5418         if (is_type_integer(type)) {
5419                 result = promote_integer(type);
5420         } else if (type == type_float) {
5421                 result = type_double;
5422         }
5423
5424         return result;
5425 }
5426
5427 static void parse_kr_declaration_list(entity_t *entity)
5428 {
5429         if (entity->kind != ENTITY_FUNCTION)
5430                 return;
5431
5432         type_t *type = skip_typeref(entity->declaration.type);
5433         assert(is_type_function(type));
5434         if (!type->function.kr_style_parameters)
5435                 return;
5436
5437
5438         add_anchor_token('{');
5439
5440         /* push function parameters */
5441         size_t const  top       = environment_top();
5442         scope_t      *old_scope = scope_push(&entity->function.parameters);
5443
5444         entity_t *parameter = entity->function.parameters.entities;
5445         for ( ; parameter != NULL; parameter = parameter->base.next) {
5446                 assert(parameter->base.parent_scope == NULL);
5447                 parameter->base.parent_scope = current_scope;
5448                 environment_push(parameter);
5449         }
5450
5451         /* parse declaration list */
5452         for (;;) {
5453                 switch (token.type) {
5454                         DECLARATION_START
5455                         case T___extension__:
5456                         /* This covers symbols, which are no type, too, and results in
5457                          * better error messages.  The typical cases are misspelled type
5458                          * names and missing includes. */
5459                         case T_IDENTIFIER:
5460                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5461                                 break;
5462                         default:
5463                                 goto decl_list_end;
5464                 }
5465         }
5466 decl_list_end:
5467
5468         /* pop function parameters */
5469         assert(current_scope == &entity->function.parameters);
5470         scope_pop(old_scope);
5471         environment_pop_to(top);
5472
5473         /* update function type */
5474         type_t *new_type = duplicate_type(type);
5475
5476         function_parameter_t *parameters     = NULL;
5477         function_parameter_t *last_parameter = NULL;
5478
5479         parameter = entity->function.parameters.entities;
5480         for (; parameter != NULL; parameter = parameter->base.next) {
5481                 type_t *parameter_type = parameter->declaration.type;
5482                 if (parameter_type == NULL) {
5483                         if (strict_mode) {
5484                                 errorf(HERE, "no type specified for function parameter '%Y'",
5485                                        parameter->base.symbol);
5486                         } else {
5487                                 if (warning.implicit_int) {
5488                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5489                                                  parameter->base.symbol);
5490                                 }
5491                                 parameter_type              = type_int;
5492                                 parameter->declaration.type = parameter_type;
5493                         }
5494                 }
5495
5496                 semantic_parameter_incomplete(parameter);
5497                 parameter_type = parameter->declaration.type;
5498
5499                 /*
5500                  * we need the default promoted types for the function type
5501                  */
5502                 parameter_type = get_default_promoted_type(parameter_type);
5503
5504                 function_parameter_t *function_parameter
5505                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5506                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5507
5508                 function_parameter->type = parameter_type;
5509                 if (last_parameter != NULL) {
5510                         last_parameter->next = function_parameter;
5511                 } else {
5512                         parameters = function_parameter;
5513                 }
5514                 last_parameter = function_parameter;
5515         }
5516
5517         /* Â§ 6.9.1.7: A K&R style parameter list does NOT act as a function
5518          * prototype */
5519         new_type->function.parameters             = parameters;
5520         new_type->function.unspecified_parameters = true;
5521
5522         type = typehash_insert(new_type);
5523         if (type != new_type) {
5524                 obstack_free(type_obst, new_type);
5525         }
5526
5527         entity->declaration.type = type;
5528
5529         rem_anchor_token('{');
5530 }
5531
5532 static bool first_err = true;
5533
5534 /**
5535  * When called with first_err set, prints the name of the current function,
5536  * else does noting.
5537  */
5538 static void print_in_function(void)
5539 {
5540         if (first_err) {
5541                 first_err = false;
5542                 diagnosticf("%s: In function '%Y':\n",
5543                             current_function->base.base.source_position.input_name,
5544                             current_function->base.base.symbol);
5545         }
5546 }
5547
5548 /**
5549  * Check if all labels are defined in the current function.
5550  * Check if all labels are used in the current function.
5551  */
5552 static void check_labels(void)
5553 {
5554         for (const goto_statement_t *goto_statement = goto_first;
5555             goto_statement != NULL;
5556             goto_statement = goto_statement->next) {
5557                 /* skip computed gotos */
5558                 if (goto_statement->expression != NULL)
5559                         continue;
5560
5561                 label_t *label = goto_statement->label;
5562
5563                 label->used = true;
5564                 if (label->base.source_position.input_name == NULL) {
5565                         print_in_function();
5566                         errorf(&goto_statement->base.source_position,
5567                                "label '%Y' used but not defined", label->base.symbol);
5568                  }
5569         }
5570
5571         if (warning.unused_label) {
5572                 for (const label_statement_t *label_statement = label_first;
5573                          label_statement != NULL;
5574                          label_statement = label_statement->next) {
5575                         label_t *label = label_statement->label;
5576
5577                         if (! label->used) {
5578                                 print_in_function();
5579                                 warningf(&label_statement->base.source_position,
5580                                          "label '%Y' defined but not used", label->base.symbol);
5581                         }
5582                 }
5583         }
5584 }
5585
5586 static void warn_unused_entity(entity_t *entity, entity_t *end)
5587 {
5588         for (; entity != NULL; entity = entity->base.next) {
5589                 if (!is_declaration(entity))
5590                         continue;
5591
5592                 declaration_t *declaration = &entity->declaration;
5593                 if (declaration->implicit)
5594                         continue;
5595
5596                 if (!declaration->used) {
5597                         print_in_function();
5598                         const char *what = get_entity_kind_name(entity->kind);
5599                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5600                                  what, entity->base.symbol);
5601                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5602                         print_in_function();
5603                         const char *what = get_entity_kind_name(entity->kind);
5604                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5605                                  what, entity->base.symbol);
5606                 }
5607
5608                 if (entity == end)
5609                         break;
5610         }
5611 }
5612
5613 static void check_unused_variables(statement_t *const stmt, void *const env)
5614 {
5615         (void)env;
5616
5617         switch (stmt->kind) {
5618                 case STATEMENT_DECLARATION: {
5619                         declaration_statement_t const *const decls = &stmt->declaration;
5620                         warn_unused_entity(decls->declarations_begin,
5621                                            decls->declarations_end);
5622                         return;
5623                 }
5624
5625                 case STATEMENT_FOR:
5626                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5627                         return;
5628
5629                 default:
5630                         return;
5631         }
5632 }
5633
5634 /**
5635  * Check declarations of current_function for unused entities.
5636  */
5637 static void check_declarations(void)
5638 {
5639         if (warning.unused_parameter) {
5640                 const scope_t *scope = &current_function->parameters;
5641
5642                 /* do not issue unused warnings for main */
5643                 if (!is_sym_main(current_function->base.base.symbol)) {
5644                         warn_unused_entity(scope->entities, NULL);
5645                 }
5646         }
5647         if (warning.unused_variable) {
5648                 walk_statements(current_function->statement, check_unused_variables,
5649                                 NULL);
5650         }
5651 }
5652
5653 static int determine_truth(expression_t const* const cond)
5654 {
5655         return
5656                 !is_constant_expression(cond) ? 0 :
5657                 fold_constant(cond) != 0      ? 1 :
5658                 -1;
5659 }
5660
5661 static void check_reachable(statement_t *);
5662 static bool reaches_end;
5663
5664 static bool expression_returns(expression_t const *const expr)
5665 {
5666         switch (expr->kind) {
5667                 case EXPR_CALL: {
5668                         expression_t const *const func = expr->call.function;
5669                         if (func->kind == EXPR_REFERENCE) {
5670                                 entity_t *entity = func->reference.entity;
5671                                 if (entity->kind == ENTITY_FUNCTION
5672                                                 && entity->declaration.modifiers & DM_NORETURN)
5673                                         return false;
5674                         }
5675
5676                         if (!expression_returns(func))
5677                                 return false;
5678
5679                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5680                                 if (!expression_returns(arg->expression))
5681                                         return false;
5682                         }
5683
5684                         return true;
5685                 }
5686
5687                 case EXPR_REFERENCE:
5688                 case EXPR_REFERENCE_ENUM_VALUE:
5689                 case EXPR_CONST:
5690                 case EXPR_CHARACTER_CONSTANT:
5691                 case EXPR_WIDE_CHARACTER_CONSTANT:
5692                 case EXPR_STRING_LITERAL:
5693                 case EXPR_WIDE_STRING_LITERAL:
5694                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5695                 case EXPR_LABEL_ADDRESS:
5696                 case EXPR_CLASSIFY_TYPE:
5697                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5698                 case EXPR_ALIGNOF:
5699                 case EXPR_FUNCNAME:
5700                 case EXPR_BUILTIN_SYMBOL:
5701                 case EXPR_BUILTIN_CONSTANT_P:
5702                 case EXPR_BUILTIN_PREFETCH:
5703                 case EXPR_OFFSETOF:
5704                 case EXPR_INVALID:
5705                         return true;
5706
5707                 case EXPR_STATEMENT: {
5708                         bool old_reaches_end = reaches_end;
5709                         reaches_end = false;
5710                         check_reachable(expr->statement.statement);
5711                         bool returns = reaches_end;
5712                         reaches_end = old_reaches_end;
5713                         return returns;
5714                 }
5715
5716                 case EXPR_CONDITIONAL:
5717                         // TODO handle constant expression
5718
5719                         if (!expression_returns(expr->conditional.condition))
5720                                 return false;
5721
5722                         if (expr->conditional.true_expression != NULL
5723                                         && expression_returns(expr->conditional.true_expression))
5724                                 return true;
5725
5726                         return expression_returns(expr->conditional.false_expression);
5727
5728                 case EXPR_SELECT:
5729                         return expression_returns(expr->select.compound);
5730
5731                 case EXPR_ARRAY_ACCESS:
5732                         return
5733                                 expression_returns(expr->array_access.array_ref) &&
5734                                 expression_returns(expr->array_access.index);
5735
5736                 case EXPR_VA_START:
5737                         return expression_returns(expr->va_starte.ap);
5738
5739                 case EXPR_VA_ARG:
5740                         return expression_returns(expr->va_arge.ap);
5741
5742                 EXPR_UNARY_CASES_MANDATORY
5743                         return expression_returns(expr->unary.value);
5744
5745                 case EXPR_UNARY_THROW:
5746                         return false;
5747
5748                 EXPR_BINARY_CASES
5749                         // TODO handle constant lhs of && and ||
5750                         return
5751                                 expression_returns(expr->binary.left) &&
5752                                 expression_returns(expr->binary.right);
5753
5754                 case EXPR_UNKNOWN:
5755                         break;
5756         }
5757
5758         panic("unhandled expression");
5759 }
5760
5761 static bool initializer_returns(initializer_t const *const init)
5762 {
5763         switch (init->kind) {
5764                 case INITIALIZER_VALUE:
5765                         return expression_returns(init->value.value);
5766
5767                 case INITIALIZER_LIST: {
5768                         initializer_t * const*       i       = init->list.initializers;
5769                         initializer_t * const* const end     = i + init->list.len;
5770                         bool                         returns = true;
5771                         for (; i != end; ++i) {
5772                                 if (!initializer_returns(*i))
5773                                         returns = false;
5774                         }
5775                         return returns;
5776                 }
5777
5778                 case INITIALIZER_STRING:
5779                 case INITIALIZER_WIDE_STRING:
5780                 case INITIALIZER_DESIGNATOR: // designators have no payload
5781                         return true;
5782         }
5783         panic("unhandled initializer");
5784 }
5785
5786 static bool noreturn_candidate;
5787
5788 static void check_reachable(statement_t *const stmt)
5789 {
5790         if (stmt->base.reachable)
5791                 return;
5792         if (stmt->kind != STATEMENT_DO_WHILE)
5793                 stmt->base.reachable = true;
5794
5795         statement_t *last = stmt;
5796         statement_t *next;
5797         switch (stmt->kind) {
5798                 case STATEMENT_INVALID:
5799                 case STATEMENT_EMPTY:
5800                 case STATEMENT_LOCAL_LABEL:
5801                 case STATEMENT_ASM:
5802                         next = stmt->base.next;
5803                         break;
5804
5805                 case STATEMENT_DECLARATION: {
5806                         declaration_statement_t const *const decl = &stmt->declaration;
5807                         entity_t                const *      ent  = decl->declarations_begin;
5808                         entity_t                const *const last = decl->declarations_end;
5809                         if (ent != NULL) {
5810                                 for (;; ent = ent->base.next) {
5811                                         if (ent->kind                 == ENTITY_VARIABLE &&
5812                                                         ent->variable.initializer != NULL            &&
5813                                                         !initializer_returns(ent->variable.initializer)) {
5814                                                 return;
5815                                         }
5816                                         if (ent == last)
5817                                                 break;
5818                                 }
5819                         }
5820                         next = stmt->base.next;
5821                         break;
5822                 }
5823
5824                 case STATEMENT_COMPOUND:
5825                         next = stmt->compound.statements;
5826                         break;
5827
5828                 case STATEMENT_RETURN: {
5829                         expression_t const *const val = stmt->returns.value;
5830                         if (val == NULL || expression_returns(val))
5831                                 noreturn_candidate = false;
5832                         return;
5833                 }
5834
5835                 case STATEMENT_IF: {
5836                         if_statement_t const *const ifs  = &stmt->ifs;
5837                         expression_t   const *const cond = ifs->condition;
5838
5839                         if (!expression_returns(cond))
5840                                 return;
5841
5842                         int const val = determine_truth(cond);
5843
5844                         if (val >= 0)
5845                                 check_reachable(ifs->true_statement);
5846
5847                         if (val > 0)
5848                                 return;
5849
5850                         if (ifs->false_statement != NULL) {
5851                                 check_reachable(ifs->false_statement);
5852                                 return;
5853                         }
5854
5855                         next = stmt->base.next;
5856                         break;
5857                 }
5858
5859                 case STATEMENT_SWITCH: {
5860                         switch_statement_t const *const switchs = &stmt->switchs;
5861                         expression_t       const *const expr    = switchs->expression;
5862
5863                         if (!expression_returns(expr))
5864                                 return;
5865
5866                         if (is_constant_expression(expr)) {
5867                                 long                    const val      = fold_constant(expr);
5868                                 case_label_statement_t *      defaults = NULL;
5869                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5870                                         if (i->expression == NULL) {
5871                                                 defaults = i;
5872                                                 continue;
5873                                         }
5874
5875                                         if (i->first_case <= val && val <= i->last_case) {
5876                                                 check_reachable((statement_t*)i);
5877                                                 return;
5878                                         }
5879                                 }
5880
5881                                 if (defaults != NULL) {
5882                                         check_reachable((statement_t*)defaults);
5883                                         return;
5884                                 }
5885                         } else {
5886                                 bool has_default = false;
5887                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5888                                         if (i->expression == NULL)
5889                                                 has_default = true;
5890
5891                                         check_reachable((statement_t*)i);
5892                                 }
5893
5894                                 if (has_default)
5895                                         return;
5896                         }
5897
5898                         next = stmt->base.next;
5899                         break;
5900                 }
5901
5902                 case STATEMENT_EXPRESSION: {
5903                         /* Check for noreturn function call */
5904                         expression_t const *const expr = stmt->expression.expression;
5905                         if (!expression_returns(expr))
5906                                 return;
5907
5908                         next = stmt->base.next;
5909                         break;
5910                 }
5911
5912                 case STATEMENT_CONTINUE: {
5913                         statement_t *parent = stmt;
5914                         for (;;) {
5915                                 parent = parent->base.parent;
5916                                 if (parent == NULL) /* continue not within loop */
5917                                         return;
5918
5919                                 next = parent;
5920                                 switch (parent->kind) {
5921                                         case STATEMENT_WHILE:    goto continue_while;
5922                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5923                                         case STATEMENT_FOR:      goto continue_for;
5924
5925                                         default: break;
5926                                 }
5927                         }
5928                 }
5929
5930                 case STATEMENT_BREAK: {
5931                         statement_t *parent = stmt;
5932                         for (;;) {
5933                                 parent = parent->base.parent;
5934                                 if (parent == NULL) /* break not within loop/switch */
5935                                         return;
5936
5937                                 switch (parent->kind) {
5938                                         case STATEMENT_SWITCH:
5939                                         case STATEMENT_WHILE:
5940                                         case STATEMENT_DO_WHILE:
5941                                         case STATEMENT_FOR:
5942                                                 last = parent;
5943                                                 next = parent->base.next;
5944                                                 goto found_break_parent;
5945
5946                                         default: break;
5947                                 }
5948                         }
5949 found_break_parent:
5950                         break;
5951                 }
5952
5953                 case STATEMENT_GOTO:
5954                         if (stmt->gotos.expression) {
5955                                 if (!expression_returns(stmt->gotos.expression))
5956                                         return;
5957
5958                                 statement_t *parent = stmt->base.parent;
5959                                 if (parent == NULL) /* top level goto */
5960                                         return;
5961                                 next = parent;
5962                         } else {
5963                                 next = stmt->gotos.label->statement;
5964                                 if (next == NULL) /* missing label */
5965                                         return;
5966                         }
5967                         break;
5968
5969                 case STATEMENT_LABEL:
5970                         next = stmt->label.statement;
5971                         break;
5972
5973                 case STATEMENT_CASE_LABEL:
5974                         next = stmt->case_label.statement;
5975                         break;
5976
5977                 case STATEMENT_WHILE: {
5978                         while_statement_t const *const whiles = &stmt->whiles;
5979                         expression_t      const *const cond   = whiles->condition;
5980
5981                         if (!expression_returns(cond))
5982                                 return;
5983
5984                         int const val = determine_truth(cond);
5985
5986                         if (val >= 0)
5987                                 check_reachable(whiles->body);
5988
5989                         if (val > 0)
5990                                 return;
5991
5992                         next = stmt->base.next;
5993                         break;
5994                 }
5995
5996                 case STATEMENT_DO_WHILE:
5997                         next = stmt->do_while.body;
5998                         break;
5999
6000                 case STATEMENT_FOR: {
6001                         for_statement_t *const fors = &stmt->fors;
6002
6003                         if (fors->condition_reachable)
6004                                 return;
6005                         fors->condition_reachable = true;
6006
6007                         expression_t const *const cond = fors->condition;
6008
6009                         int val;
6010                         if (cond == NULL) {
6011                                 val = 1;
6012                         } else if (expression_returns(cond)) {
6013                                 val = determine_truth(cond);
6014                         } else {
6015                                 return;
6016                         }
6017
6018                         if (val >= 0)
6019                                 check_reachable(fors->body);
6020
6021                         if (val > 0)
6022                                 return;
6023
6024                         next = stmt->base.next;
6025                         break;
6026                 }
6027
6028                 case STATEMENT_MS_TRY: {
6029                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6030                         check_reachable(ms_try->try_statement);
6031                         next = ms_try->final_statement;
6032                         break;
6033                 }
6034
6035                 case STATEMENT_LEAVE: {
6036                         statement_t *parent = stmt;
6037                         for (;;) {
6038                                 parent = parent->base.parent;
6039                                 if (parent == NULL) /* __leave not within __try */
6040                                         return;
6041
6042                                 if (parent->kind == STATEMENT_MS_TRY) {
6043                                         last = parent;
6044                                         next = parent->ms_try.final_statement;
6045                                         break;
6046                                 }
6047                         }
6048                         break;
6049                 }
6050
6051                 default:
6052                         panic("invalid statement kind");
6053         }
6054
6055         while (next == NULL) {
6056                 next = last->base.parent;
6057                 if (next == NULL) {
6058                         noreturn_candidate = false;
6059
6060                         type_t *const type = current_function->base.type;
6061                         assert(is_type_function(type));
6062                         type_t *const ret  = skip_typeref(type->function.return_type);
6063                         if (warning.return_type                    &&
6064                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6065                             is_type_valid(ret)                     &&
6066                             !is_sym_main(current_function->base.base.symbol)) {
6067                                 warningf(&stmt->base.source_position,
6068                                          "control reaches end of non-void function");
6069                         }
6070                         return;
6071                 }
6072
6073                 switch (next->kind) {
6074                         case STATEMENT_INVALID:
6075                         case STATEMENT_EMPTY:
6076                         case STATEMENT_DECLARATION:
6077                         case STATEMENT_LOCAL_LABEL:
6078                         case STATEMENT_EXPRESSION:
6079                         case STATEMENT_ASM:
6080                         case STATEMENT_RETURN:
6081                         case STATEMENT_CONTINUE:
6082                         case STATEMENT_BREAK:
6083                         case STATEMENT_GOTO:
6084                         case STATEMENT_LEAVE:
6085                                 panic("invalid control flow in function");
6086
6087                         case STATEMENT_COMPOUND:
6088                                 if (next->compound.stmt_expr) {
6089                                         reaches_end = true;
6090                                         return;
6091                                 }
6092                                 /* FALLTHROUGH */
6093                         case STATEMENT_IF:
6094                         case STATEMENT_SWITCH:
6095                         case STATEMENT_LABEL:
6096                         case STATEMENT_CASE_LABEL:
6097                                 last = next;
6098                                 next = next->base.next;
6099                                 break;
6100
6101                         case STATEMENT_WHILE: {
6102 continue_while:
6103                                 if (next->base.reachable)
6104                                         return;
6105                                 next->base.reachable = true;
6106
6107                                 while_statement_t const *const whiles = &next->whiles;
6108                                 expression_t      const *const cond   = whiles->condition;
6109
6110                                 if (!expression_returns(cond))
6111                                         return;
6112
6113                                 int const val = determine_truth(cond);
6114
6115                                 if (val >= 0)
6116                                         check_reachable(whiles->body);
6117
6118                                 if (val > 0)
6119                                         return;
6120
6121                                 last = next;
6122                                 next = next->base.next;
6123                                 break;
6124                         }
6125
6126                         case STATEMENT_DO_WHILE: {
6127 continue_do_while:
6128                                 if (next->base.reachable)
6129                                         return;
6130                                 next->base.reachable = true;
6131
6132                                 do_while_statement_t const *const dw   = &next->do_while;
6133                                 expression_t         const *const cond = dw->condition;
6134
6135                                 if (!expression_returns(cond))
6136                                         return;
6137
6138                                 int const val = determine_truth(cond);
6139
6140                                 if (val >= 0)
6141                                         check_reachable(dw->body);
6142
6143                                 if (val > 0)
6144                                         return;
6145
6146                                 last = next;
6147                                 next = next->base.next;
6148                                 break;
6149                         }
6150
6151                         case STATEMENT_FOR: {
6152 continue_for:;
6153                                 for_statement_t *const fors = &next->fors;
6154
6155                                 fors->step_reachable = true;
6156
6157                                 if (fors->condition_reachable)
6158                                         return;
6159                                 fors->condition_reachable = true;
6160
6161                                 expression_t const *const cond = fors->condition;
6162
6163                                 int val;
6164                                 if (cond == NULL) {
6165                                         val = 1;
6166                                 } else if (expression_returns(cond)) {
6167                                         val = determine_truth(cond);
6168                                 } else {
6169                                         return;
6170                                 }
6171
6172                                 if (val >= 0)
6173                                         check_reachable(fors->body);
6174
6175                                 if (val > 0)
6176                                         return;
6177
6178                                 last = next;
6179                                 next = next->base.next;
6180                                 break;
6181                         }
6182
6183                         case STATEMENT_MS_TRY:
6184                                 last = next;
6185                                 next = next->ms_try.final_statement;
6186                                 break;
6187                 }
6188         }
6189
6190         check_reachable(next);
6191 }
6192
6193 static void check_unreachable(statement_t* const stmt, void *const env)
6194 {
6195         (void)env;
6196
6197         switch (stmt->kind) {
6198                 case STATEMENT_DO_WHILE:
6199                         if (!stmt->base.reachable) {
6200                                 expression_t const *const cond = stmt->do_while.condition;
6201                                 if (determine_truth(cond) >= 0) {
6202                                         warningf(&cond->base.source_position,
6203                                                  "condition of do-while-loop is unreachable");
6204                                 }
6205                         }
6206                         return;
6207
6208                 case STATEMENT_FOR: {
6209                         for_statement_t const* const fors = &stmt->fors;
6210
6211                         // if init and step are unreachable, cond is unreachable, too
6212                         if (!stmt->base.reachable && !fors->step_reachable) {
6213                                 warningf(&stmt->base.source_position, "statement is unreachable");
6214                         } else {
6215                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6216                                         warningf(&fors->initialisation->base.source_position,
6217                                                  "initialisation of for-statement is unreachable");
6218                                 }
6219
6220                                 if (!fors->condition_reachable && fors->condition != NULL) {
6221                                         warningf(&fors->condition->base.source_position,
6222                                                  "condition of for-statement is unreachable");
6223                                 }
6224
6225                                 if (!fors->step_reachable && fors->step != NULL) {
6226                                         warningf(&fors->step->base.source_position,
6227                                                  "step of for-statement is unreachable");
6228                                 }
6229                         }
6230                         return;
6231                 }
6232
6233                 case STATEMENT_COMPOUND:
6234                         if (stmt->compound.statements != NULL)
6235                                 return;
6236                         goto warn_unreachable;
6237
6238                 case STATEMENT_DECLARATION: {
6239                         /* Only warn if there is at least one declarator with an initializer.
6240                          * This typically occurs in switch statements. */
6241                         declaration_statement_t const *const decl = &stmt->declaration;
6242                         entity_t                const *      ent  = decl->declarations_begin;
6243                         entity_t                const *const last = decl->declarations_end;
6244                         if (ent != NULL) {
6245                                 for (;; ent = ent->base.next) {
6246                                         if (ent->kind                 == ENTITY_VARIABLE &&
6247                                                         ent->variable.initializer != NULL) {
6248                                                 goto warn_unreachable;
6249                                         }
6250                                         if (ent == last)
6251                                                 return;
6252                                 }
6253                         }
6254                 }
6255
6256                 default:
6257 warn_unreachable:
6258                         if (!stmt->base.reachable)
6259                                 warningf(&stmt->base.source_position, "statement is unreachable");
6260                         return;
6261         }
6262 }
6263
6264 static void parse_external_declaration(void)
6265 {
6266         /* function-definitions and declarations both start with declaration
6267          * specifiers */
6268         declaration_specifiers_t specifiers;
6269         memset(&specifiers, 0, sizeof(specifiers));
6270
6271         add_anchor_token(';');
6272         parse_declaration_specifiers(&specifiers);
6273         rem_anchor_token(';');
6274
6275         /* must be a declaration */
6276         if (token.type == ';') {
6277                 parse_anonymous_declaration_rest(&specifiers);
6278                 return;
6279         }
6280
6281         add_anchor_token(',');
6282         add_anchor_token('=');
6283         add_anchor_token(';');
6284         add_anchor_token('{');
6285
6286         /* declarator is common to both function-definitions and declarations */
6287         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6288
6289         rem_anchor_token('{');
6290         rem_anchor_token(';');
6291         rem_anchor_token('=');
6292         rem_anchor_token(',');
6293
6294         /* must be a declaration */
6295         switch (token.type) {
6296                 case ',':
6297                 case ';':
6298                 case '=':
6299                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6300                                         DECL_FLAGS_NONE);
6301                         return;
6302         }
6303
6304         /* must be a function definition */
6305         parse_kr_declaration_list(ndeclaration);
6306
6307         if (token.type != '{') {
6308                 parse_error_expected("while parsing function definition", '{', NULL);
6309                 eat_until_matching_token(';');
6310                 return;
6311         }
6312
6313         assert(is_declaration(ndeclaration));
6314         type_t *type = skip_typeref(ndeclaration->declaration.type);
6315
6316         if (!is_type_function(type)) {
6317                 if (is_type_valid(type)) {
6318                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6319                                type, ndeclaration->base.symbol);
6320                 }
6321                 eat_block();
6322                 return;
6323         }
6324
6325         if (warning.aggregate_return &&
6326             is_type_compound(skip_typeref(type->function.return_type))) {
6327                 warningf(HERE, "function '%Y' returns an aggregate",
6328                          ndeclaration->base.symbol);
6329         }
6330         if (warning.traditional && !type->function.unspecified_parameters) {
6331                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6332                         ndeclaration->base.symbol);
6333         }
6334         if (warning.old_style_definition && type->function.unspecified_parameters) {
6335                 warningf(HERE, "old-style function definition '%Y'",
6336                         ndeclaration->base.symbol);
6337         }
6338
6339         /* Â§ 6.7.5.3 (14) a function definition with () means no
6340          * parameters (and not unspecified parameters) */
6341         if (type->function.unspecified_parameters
6342                         && type->function.parameters == NULL
6343                         && !type->function.kr_style_parameters) {
6344                 type_t *duplicate = duplicate_type(type);
6345                 duplicate->function.unspecified_parameters = false;
6346
6347                 type = typehash_insert(duplicate);
6348                 if (type != duplicate) {
6349                         obstack_free(type_obst, duplicate);
6350                 }
6351                 ndeclaration->declaration.type = type;
6352         }
6353
6354         entity_t *const entity = record_entity(ndeclaration, true);
6355         assert(entity->kind == ENTITY_FUNCTION);
6356         assert(ndeclaration->kind == ENTITY_FUNCTION);
6357
6358         function_t *function = &entity->function;
6359         if (ndeclaration != entity) {
6360                 function->parameters = ndeclaration->function.parameters;
6361         }
6362         assert(is_declaration(entity));
6363         type = skip_typeref(entity->declaration.type);
6364
6365         /* push function parameters and switch scope */
6366         size_t const  top       = environment_top();
6367         scope_t      *old_scope = scope_push(&function->parameters);
6368
6369         entity_t *parameter = function->parameters.entities;
6370         for (; parameter != NULL; parameter = parameter->base.next) {
6371                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6372                         parameter->base.parent_scope = current_scope;
6373                 }
6374                 assert(parameter->base.parent_scope == NULL
6375                                 || parameter->base.parent_scope == current_scope);
6376                 parameter->base.parent_scope = current_scope;
6377                 if (parameter->base.symbol == NULL) {
6378                         errorf(&parameter->base.source_position, "parameter name omitted");
6379                         continue;
6380                 }
6381                 environment_push(parameter);
6382         }
6383
6384         if (function->statement != NULL) {
6385                 parser_error_multiple_definition(entity, HERE);
6386                 eat_block();
6387         } else {
6388                 /* parse function body */
6389                 int         label_stack_top      = label_top();
6390                 function_t *old_current_function = current_function;
6391                 current_function                 = function;
6392                 current_parent                   = NULL;
6393
6394                 goto_first   = NULL;
6395                 goto_anchor  = &goto_first;
6396                 label_first  = NULL;
6397                 label_anchor = &label_first;
6398
6399                 statement_t *const body = parse_compound_statement(false);
6400                 function->statement = body;
6401                 first_err = true;
6402                 check_labels();
6403                 check_declarations();
6404                 if (warning.return_type      ||
6405                     warning.unreachable_code ||
6406                     (warning.missing_noreturn
6407                      && !(function->base.modifiers & DM_NORETURN))) {
6408                         noreturn_candidate = true;
6409                         check_reachable(body);
6410                         if (warning.unreachable_code)
6411                                 walk_statements(body, check_unreachable, NULL);
6412                         if (warning.missing_noreturn &&
6413                             noreturn_candidate       &&
6414                             !(function->base.modifiers & DM_NORETURN)) {
6415                                 warningf(&body->base.source_position,
6416                                          "function '%#T' is candidate for attribute 'noreturn'",
6417                                          type, entity->base.symbol);
6418                         }
6419                 }
6420
6421                 assert(current_parent   == NULL);
6422                 assert(current_function == function);
6423                 current_function = old_current_function;
6424                 label_pop_to(label_stack_top);
6425         }
6426
6427         assert(current_scope == &function->parameters);
6428         scope_pop(old_scope);
6429         environment_pop_to(top);
6430 }
6431
6432 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6433                                   source_position_t *source_position,
6434                                   const symbol_t *symbol)
6435 {
6436         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6437
6438         type->bitfield.base_type       = base_type;
6439         type->bitfield.size_expression = size;
6440
6441         il_size_t bit_size;
6442         type_t *skipped_type = skip_typeref(base_type);
6443         if (!is_type_integer(skipped_type)) {
6444                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6445                         base_type);
6446                 bit_size = 0;
6447         } else {
6448                 bit_size = skipped_type->base.size * 8;
6449         }
6450
6451         if (is_constant_expression(size)) {
6452                 long v = fold_constant(size);
6453
6454                 if (v < 0) {
6455                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6456                 } else if (v == 0) {
6457                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6458                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6459                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6460                 } else {
6461                         type->bitfield.bit_size = v;
6462                 }
6463         }
6464
6465         return type;
6466 }
6467
6468 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6469 {
6470         entity_t *iter = compound->members.entities;
6471         for (; iter != NULL; iter = iter->base.next) {
6472                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6473                         continue;
6474
6475                 if (iter->base.symbol == symbol) {
6476                         return iter;
6477                 } else if (iter->base.symbol == NULL) {
6478                         type_t *type = skip_typeref(iter->declaration.type);
6479                         if (is_type_compound(type)) {
6480                                 entity_t *result
6481                                         = find_compound_entry(type->compound.compound, symbol);
6482                                 if (result != NULL)
6483                                         return result;
6484                         }
6485                         continue;
6486                 }
6487         }
6488
6489         return NULL;
6490 }
6491
6492 static void parse_compound_declarators(compound_t *compound,
6493                 const declaration_specifiers_t *specifiers)
6494 {
6495         while (true) {
6496                 entity_t *entity;
6497
6498                 if (token.type == ':') {
6499                         source_position_t source_position = *HERE;
6500                         next_token();
6501
6502                         type_t *base_type = specifiers->type;
6503                         expression_t *size = parse_constant_expression();
6504
6505                         type_t *type = make_bitfield_type(base_type, size,
6506                                         &source_position, sym_anonymous);
6507
6508                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6509                         entity->base.namespc                       = NAMESPACE_NORMAL;
6510                         entity->base.source_position               = source_position;
6511                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6512                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6513                         entity->declaration.modifiers              = specifiers->modifiers;
6514                         entity->declaration.type                   = type;
6515                 } else {
6516                         entity = parse_declarator(specifiers,
6517                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6518                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6519
6520                         if (token.type == ':') {
6521                                 source_position_t source_position = *HERE;
6522                                 next_token();
6523                                 expression_t *size = parse_constant_expression();
6524
6525                                 type_t *type = entity->declaration.type;
6526                                 type_t *bitfield_type = make_bitfield_type(type, size,
6527                                                 &source_position, entity->base.symbol);
6528                                 entity->declaration.type = bitfield_type;
6529                         }
6530                 }
6531
6532                 /* make sure we don't define a symbol multiple times */
6533                 symbol_t *symbol = entity->base.symbol;
6534                 if (symbol != NULL) {
6535                         entity_t *prev = find_compound_entry(compound, symbol);
6536
6537                         if (prev != NULL) {
6538                                 errorf(&entity->base.source_position,
6539                                        "multiple declarations of symbol '%Y' (declared %P)",
6540                                        symbol, &prev->base.source_position);
6541                         }
6542                 }
6543
6544                 append_entity(&compound->members, entity);
6545
6546                 type_t *orig_type = entity->declaration.type;
6547                 type_t *type      = skip_typeref(orig_type);
6548                 if (is_type_function(type)) {
6549                         errorf(&entity->base.source_position,
6550                                         "compound member '%Y' must not have function type '%T'",
6551                                         entity->base.symbol, orig_type);
6552                 } else if (is_type_incomplete(type)) {
6553                         /* Â§6.7.2.1:16 flexible array member */
6554                         if (is_type_array(type) &&
6555                                         token.type == ';'   &&
6556                                         look_ahead(1)->type == '}') {
6557                                 compound->has_flexible_member = true;
6558                         } else {
6559                                 errorf(&entity->base.source_position,
6560                                                 "compound member '%Y' has incomplete type '%T'",
6561                                                 entity->base.symbol, orig_type);
6562                         }
6563                 }
6564
6565                 if (token.type != ',')
6566                         break;
6567                 next_token();
6568         }
6569         expect(';', end_error);
6570
6571 end_error:
6572         anonymous_entity = NULL;
6573 }
6574
6575 static void parse_compound_type_entries(compound_t *compound)
6576 {
6577         eat('{');
6578         add_anchor_token('}');
6579
6580         while (token.type != '}') {
6581                 if (token.type == T_EOF) {
6582                         errorf(HERE, "EOF while parsing struct");
6583                         break;
6584                 }
6585                 declaration_specifiers_t specifiers;
6586                 memset(&specifiers, 0, sizeof(specifiers));
6587                 parse_declaration_specifiers(&specifiers);
6588
6589                 parse_compound_declarators(compound, &specifiers);
6590         }
6591         rem_anchor_token('}');
6592         next_token();
6593
6594         /* Â§6.7.2.1:7 */
6595         compound->complete = true;
6596 }
6597
6598 static type_t *parse_typename(void)
6599 {
6600         declaration_specifiers_t specifiers;
6601         memset(&specifiers, 0, sizeof(specifiers));
6602         parse_declaration_specifiers(&specifiers);
6603         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6604                         specifiers.thread_local) {
6605                 /* TODO: improve error message, user does probably not know what a
6606                  * storage class is...
6607                  */
6608                 errorf(HERE, "typename may not have a storage class");
6609         }
6610
6611         type_t *result = parse_abstract_declarator(specifiers.type);
6612
6613         return result;
6614 }
6615
6616
6617
6618
6619 typedef expression_t* (*parse_expression_function)(void);
6620 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6621
6622 typedef struct expression_parser_function_t expression_parser_function_t;
6623 struct expression_parser_function_t {
6624         parse_expression_function        parser;
6625         unsigned                         infix_precedence;
6626         parse_expression_infix_function  infix_parser;
6627 };
6628
6629 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6630
6631 /**
6632  * Prints an error message if an expression was expected but not read
6633  */
6634 static expression_t *expected_expression_error(void)
6635 {
6636         /* skip the error message if the error token was read */
6637         if (token.type != T_ERROR) {
6638                 errorf(HERE, "expected expression, got token %K", &token);
6639         }
6640         next_token();
6641
6642         return create_invalid_expression();
6643 }
6644
6645 /**
6646  * Parse a string constant.
6647  */
6648 static expression_t *parse_string_const(void)
6649 {
6650         wide_string_t wres;
6651         if (token.type == T_STRING_LITERAL) {
6652                 string_t res = token.v.string;
6653                 next_token();
6654                 while (token.type == T_STRING_LITERAL) {
6655                         res = concat_strings(&res, &token.v.string);
6656                         next_token();
6657                 }
6658                 if (token.type != T_WIDE_STRING_LITERAL) {
6659                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6660                         /* note: that we use type_char_ptr here, which is already the
6661                          * automatic converted type. revert_automatic_type_conversion
6662                          * will construct the array type */
6663                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6664                         cnst->string.value = res;
6665                         return cnst;
6666                 }
6667
6668                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6669         } else {
6670                 wres = token.v.wide_string;
6671         }
6672         next_token();
6673
6674         for (;;) {
6675                 switch (token.type) {
6676                         case T_WIDE_STRING_LITERAL:
6677                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6678                                 break;
6679
6680                         case T_STRING_LITERAL:
6681                                 wres = concat_wide_string_string(&wres, &token.v.string);
6682                                 break;
6683
6684                         default: {
6685                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6686                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6687                                 cnst->wide_string.value = wres;
6688                                 return cnst;
6689                         }
6690                 }
6691                 next_token();
6692         }
6693 }
6694
6695 /**
6696  * Parse a boolean constant.
6697  */
6698 static expression_t *parse_bool_const(bool value)
6699 {
6700         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6701         cnst->base.type          = type_bool;
6702         cnst->conste.v.int_value = value;
6703
6704         next_token();
6705
6706         return cnst;
6707 }
6708
6709 /**
6710  * Parse an integer constant.
6711  */
6712 static expression_t *parse_int_const(void)
6713 {
6714         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6715         cnst->base.type          = token.datatype;
6716         cnst->conste.v.int_value = token.v.intvalue;
6717
6718         next_token();
6719
6720         return cnst;
6721 }
6722
6723 /**
6724  * Parse a character constant.
6725  */
6726 static expression_t *parse_character_constant(void)
6727 {
6728         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6729         cnst->base.type          = token.datatype;
6730         cnst->conste.v.character = token.v.string;
6731
6732         if (cnst->conste.v.character.size != 1) {
6733                 if (!GNU_MODE) {
6734                         errorf(HERE, "more than 1 character in character constant");
6735                 } else if (warning.multichar) {
6736                         warningf(HERE, "multi-character character constant");
6737                 }
6738         }
6739         next_token();
6740
6741         return cnst;
6742 }
6743
6744 /**
6745  * Parse a wide character constant.
6746  */
6747 static expression_t *parse_wide_character_constant(void)
6748 {
6749         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6750         cnst->base.type               = token.datatype;
6751         cnst->conste.v.wide_character = token.v.wide_string;
6752
6753         if (cnst->conste.v.wide_character.size != 1) {
6754                 if (!GNU_MODE) {
6755                         errorf(HERE, "more than 1 character in character constant");
6756                 } else if (warning.multichar) {
6757                         warningf(HERE, "multi-character character constant");
6758                 }
6759         }
6760         next_token();
6761
6762         return cnst;
6763 }
6764
6765 /**
6766  * Parse a float constant.
6767  */
6768 static expression_t *parse_float_const(void)
6769 {
6770         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6771         cnst->base.type            = token.datatype;
6772         cnst->conste.v.float_value = token.v.floatvalue;
6773
6774         next_token();
6775
6776         return cnst;
6777 }
6778
6779 static entity_t *create_implicit_function(symbol_t *symbol,
6780                 const source_position_t *source_position)
6781 {
6782         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6783         ntype->function.return_type            = type_int;
6784         ntype->function.unspecified_parameters = true;
6785         ntype->function.linkage                = LINKAGE_C;
6786
6787         type_t *type = typehash_insert(ntype);
6788         if (type != ntype) {
6789                 free_type(ntype);
6790         }
6791
6792         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6793         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6794         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6795         entity->declaration.type                   = type;
6796         entity->declaration.implicit               = true;
6797         entity->base.symbol                        = symbol;
6798         entity->base.source_position               = *source_position;
6799
6800         bool strict_prototypes_old = warning.strict_prototypes;
6801         warning.strict_prototypes  = false;
6802         record_entity(entity, false);
6803         warning.strict_prototypes = strict_prototypes_old;
6804
6805         return entity;
6806 }
6807
6808 /**
6809  * Creates a return_type (func)(argument_type) function type if not
6810  * already exists.
6811  */
6812 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6813                                     type_t *argument_type2)
6814 {
6815         function_parameter_t *parameter2
6816                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6817         memset(parameter2, 0, sizeof(parameter2[0]));
6818         parameter2->type = argument_type2;
6819
6820         function_parameter_t *parameter1
6821                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6822         memset(parameter1, 0, sizeof(parameter1[0]));
6823         parameter1->type = argument_type1;
6824         parameter1->next = parameter2;
6825
6826         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6827         type->function.return_type = return_type;
6828         type->function.parameters  = parameter1;
6829
6830         type_t *result = typehash_insert(type);
6831         if (result != type) {
6832                 free_type(type);
6833         }
6834
6835         return result;
6836 }
6837
6838 /**
6839  * Creates a return_type (func)(argument_type) function type if not
6840  * already exists.
6841  *
6842  * @param return_type    the return type
6843  * @param argument_type  the argument type
6844  */
6845 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6846 {
6847         function_parameter_t *parameter
6848                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6849         memset(parameter, 0, sizeof(parameter[0]));
6850         parameter->type = argument_type;
6851
6852         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6853         type->function.return_type = return_type;
6854         type->function.parameters  = parameter;
6855
6856         type_t *result = typehash_insert(type);
6857         if (result != type) {
6858                 free_type(type);
6859         }
6860
6861         return result;
6862 }
6863
6864 static type_t *make_function_0_type(type_t *return_type)
6865 {
6866         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6867         type->function.return_type = return_type;
6868         type->function.parameters  = NULL;
6869
6870         type_t *result = typehash_insert(type);
6871         if (result != type) {
6872                 free_type(type);
6873         }
6874
6875         return result;
6876 }
6877
6878 /**
6879  * Creates a function type for some function like builtins.
6880  *
6881  * @param symbol   the symbol describing the builtin
6882  */
6883 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6884 {
6885         switch (symbol->ID) {
6886         case T___builtin_alloca:
6887                 return make_function_1_type(type_void_ptr, type_size_t);
6888         case T___builtin_huge_val:
6889                 return make_function_0_type(type_double);
6890         case T___builtin_inf:
6891                 return make_function_0_type(type_double);
6892         case T___builtin_inff:
6893                 return make_function_0_type(type_float);
6894         case T___builtin_infl:
6895                 return make_function_0_type(type_long_double);
6896         case T___builtin_nan:
6897                 return make_function_1_type(type_double, type_char_ptr);
6898         case T___builtin_nanf:
6899                 return make_function_1_type(type_float, type_char_ptr);
6900         case T___builtin_nanl:
6901                 return make_function_1_type(type_long_double, type_char_ptr);
6902         case T___builtin_va_end:
6903                 return make_function_1_type(type_void, type_valist);
6904         case T___builtin_expect:
6905                 return make_function_2_type(type_long, type_long, type_long);
6906         default:
6907                 internal_errorf(HERE, "not implemented builtin identifier found");
6908         }
6909 }
6910
6911 /**
6912  * Performs automatic type cast as described in Â§ 6.3.2.1.
6913  *
6914  * @param orig_type  the original type
6915  */
6916 static type_t *automatic_type_conversion(type_t *orig_type)
6917 {
6918         type_t *type = skip_typeref(orig_type);
6919         if (is_type_array(type)) {
6920                 array_type_t *array_type   = &type->array;
6921                 type_t       *element_type = array_type->element_type;
6922                 unsigned      qualifiers   = array_type->base.qualifiers;
6923
6924                 return make_pointer_type(element_type, qualifiers);
6925         }
6926
6927         if (is_type_function(type)) {
6928                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6929         }
6930
6931         return orig_type;
6932 }
6933
6934 /**
6935  * reverts the automatic casts of array to pointer types and function
6936  * to function-pointer types as defined Â§ 6.3.2.1
6937  */
6938 type_t *revert_automatic_type_conversion(const expression_t *expression)
6939 {
6940         switch (expression->kind) {
6941                 case EXPR_REFERENCE: {
6942                         entity_t *entity = expression->reference.entity;
6943                         if (is_declaration(entity)) {
6944                                 return entity->declaration.type;
6945                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6946                                 return entity->enum_value.enum_type;
6947                         } else {
6948                                 panic("no declaration or enum in reference");
6949                         }
6950                 }
6951
6952                 case EXPR_SELECT: {
6953                         entity_t *entity = expression->select.compound_entry;
6954                         assert(is_declaration(entity));
6955                         type_t   *type   = entity->declaration.type;
6956                         return get_qualified_type(type,
6957                                                   expression->base.type->base.qualifiers);
6958                 }
6959
6960                 case EXPR_UNARY_DEREFERENCE: {
6961                         const expression_t *const value = expression->unary.value;
6962                         type_t             *const type  = skip_typeref(value->base.type);
6963                         assert(is_type_pointer(type));
6964                         return type->pointer.points_to;
6965                 }
6966
6967                 case EXPR_BUILTIN_SYMBOL:
6968                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6969
6970                 case EXPR_ARRAY_ACCESS: {
6971                         const expression_t *array_ref = expression->array_access.array_ref;
6972                         type_t             *type_left = skip_typeref(array_ref->base.type);
6973                         if (!is_type_valid(type_left))
6974                                 return type_left;
6975                         assert(is_type_pointer(type_left));
6976                         return type_left->pointer.points_to;
6977                 }
6978
6979                 case EXPR_STRING_LITERAL: {
6980                         size_t size = expression->string.value.size;
6981                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6982                 }
6983
6984                 case EXPR_WIDE_STRING_LITERAL: {
6985                         size_t size = expression->wide_string.value.size;
6986                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6987                 }
6988
6989                 case EXPR_COMPOUND_LITERAL:
6990                         return expression->compound_literal.type;
6991
6992                 default: break;
6993         }
6994
6995         return expression->base.type;
6996 }
6997
6998 static expression_t *parse_reference(void)
6999 {
7000         symbol_t *const symbol = token.v.symbol;
7001
7002         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7003
7004         if (entity == NULL) {
7005                 if (!strict_mode && look_ahead(1)->type == '(') {
7006                         /* an implicitly declared function */
7007                         if (warning.error_implicit_function_declaration) {
7008                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7009                         } else if (warning.implicit_function_declaration) {
7010                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7011                         }
7012
7013                         entity = create_implicit_function(symbol, HERE);
7014                 } else {
7015                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7016                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7017                 }
7018         }
7019
7020         type_t *orig_type;
7021
7022         if (is_declaration(entity)) {
7023                 orig_type = entity->declaration.type;
7024         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7025                 orig_type = entity->enum_value.enum_type;
7026         } else if (entity->kind == ENTITY_TYPEDEF) {
7027                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7028                         symbol);
7029                 next_token();
7030                 return create_invalid_expression();
7031         } else {
7032                 panic("expected declaration or enum value in reference");
7033         }
7034
7035         /* we always do the auto-type conversions; the & and sizeof parser contains
7036          * code to revert this! */
7037         type_t *type = automatic_type_conversion(orig_type);
7038
7039         expression_kind_t kind = EXPR_REFERENCE;
7040         if (entity->kind == ENTITY_ENUM_VALUE)
7041                 kind = EXPR_REFERENCE_ENUM_VALUE;
7042
7043         expression_t *expression     = allocate_expression_zero(kind);
7044         expression->reference.entity = entity;
7045         expression->base.type        = type;
7046
7047         /* this declaration is used */
7048         if (is_declaration(entity)) {
7049                 entity->declaration.used = true;
7050         }
7051
7052         if (entity->base.parent_scope != file_scope
7053                 && entity->base.parent_scope->depth < current_function->parameters.depth
7054                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7055                 if (entity->kind == ENTITY_VARIABLE) {
7056                         /* access of a variable from an outer function */
7057                         entity->variable.address_taken = true;
7058                 } else if (entity->kind == ENTITY_PARAMETER) {
7059                         entity->parameter.address_taken = true;
7060                 }
7061                 current_function->need_closure = true;
7062         }
7063
7064         /* check for deprecated functions */
7065         if (warning.deprecated_declarations
7066                 && is_declaration(entity)
7067                 && entity->declaration.modifiers & DM_DEPRECATED) {
7068                 declaration_t *declaration = &entity->declaration;
7069
7070                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7071                         "function" : "variable";
7072
7073                 if (declaration->deprecated_string != NULL) {
7074                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7075                                  prefix, entity->base.symbol, &entity->base.source_position,
7076                                  declaration->deprecated_string);
7077                 } else {
7078                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7079                                  entity->base.symbol, &entity->base.source_position);
7080                 }
7081         }
7082
7083         if (warning.init_self && entity == current_init_decl && !in_type_prop
7084             && entity->kind == ENTITY_VARIABLE) {
7085                 current_init_decl = NULL;
7086                 warningf(HERE, "variable '%#T' is initialized by itself",
7087                          entity->declaration.type, entity->base.symbol);
7088         }
7089
7090         next_token();
7091         return expression;
7092 }
7093
7094 static bool semantic_cast(expression_t *cast)
7095 {
7096         expression_t            *expression      = cast->unary.value;
7097         type_t                  *orig_dest_type  = cast->base.type;
7098         type_t                  *orig_type_right = expression->base.type;
7099         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7100         type_t            const *src_type        = skip_typeref(orig_type_right);
7101         source_position_t const *pos             = &cast->base.source_position;
7102
7103         /* Â§6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7104         if (dst_type == type_void)
7105                 return true;
7106
7107         /* only integer and pointer can be casted to pointer */
7108         if (is_type_pointer(dst_type)  &&
7109             !is_type_pointer(src_type) &&
7110             !is_type_integer(src_type) &&
7111             is_type_valid(src_type)) {
7112                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7113                 return false;
7114         }
7115
7116         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7117                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7118                 return false;
7119         }
7120
7121         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7122                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7123                 return false;
7124         }
7125
7126         if (warning.cast_qual &&
7127             is_type_pointer(src_type) &&
7128             is_type_pointer(dst_type)) {
7129                 type_t *src = skip_typeref(src_type->pointer.points_to);
7130                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7131                 unsigned missing_qualifiers =
7132                         src->base.qualifiers & ~dst->base.qualifiers;
7133                 if (missing_qualifiers != 0) {
7134                         warningf(pos,
7135                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7136                                  missing_qualifiers, orig_type_right);
7137                 }
7138         }
7139         return true;
7140 }
7141
7142 static expression_t *parse_compound_literal(type_t *type)
7143 {
7144         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7145
7146         parse_initializer_env_t env;
7147         env.type             = type;
7148         env.entity           = NULL;
7149         env.must_be_constant = false;
7150         initializer_t *initializer = parse_initializer(&env);
7151         type = env.type;
7152
7153         expression->compound_literal.initializer = initializer;
7154         expression->compound_literal.type        = type;
7155         expression->base.type                    = automatic_type_conversion(type);
7156
7157         return expression;
7158 }
7159
7160 /**
7161  * Parse a cast expression.
7162  */
7163 static expression_t *parse_cast(void)
7164 {
7165         add_anchor_token(')');
7166
7167         source_position_t source_position = token.source_position;
7168
7169         type_t *type = parse_typename();
7170
7171         rem_anchor_token(')');
7172         expect(')', end_error);
7173
7174         if (token.type == '{') {
7175                 return parse_compound_literal(type);
7176         }
7177
7178         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7179         cast->base.source_position = source_position;
7180
7181         expression_t *value = parse_sub_expression(PREC_CAST);
7182         cast->base.type   = type;
7183         cast->unary.value = value;
7184
7185         if (! semantic_cast(cast)) {
7186                 /* TODO: record the error in the AST. else it is impossible to detect it */
7187         }
7188
7189         return cast;
7190 end_error:
7191         return create_invalid_expression();
7192 }
7193
7194 /**
7195  * Parse a statement expression.
7196  */
7197 static expression_t *parse_statement_expression(void)
7198 {
7199         add_anchor_token(')');
7200
7201         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7202
7203         statement_t *statement          = parse_compound_statement(true);
7204         statement->compound.stmt_expr   = true;
7205         expression->statement.statement = statement;
7206
7207         /* find last statement and use its type */
7208         type_t *type = type_void;
7209         const statement_t *stmt = statement->compound.statements;
7210         if (stmt != NULL) {
7211                 while (stmt->base.next != NULL)
7212                         stmt = stmt->base.next;
7213
7214                 if (stmt->kind == STATEMENT_EXPRESSION) {
7215                         type = stmt->expression.expression->base.type;
7216                 }
7217         } else if (warning.other) {
7218                 warningf(&expression->base.source_position, "empty statement expression ({})");
7219         }
7220         expression->base.type = type;
7221
7222         rem_anchor_token(')');
7223         expect(')', end_error);
7224
7225 end_error:
7226         return expression;
7227 }
7228
7229 /**
7230  * Parse a parenthesized expression.
7231  */
7232 static expression_t *parse_parenthesized_expression(void)
7233 {
7234         eat('(');
7235
7236         switch (token.type) {
7237         case '{':
7238                 /* gcc extension: a statement expression */
7239                 return parse_statement_expression();
7240
7241         TYPE_QUALIFIERS
7242         TYPE_SPECIFIERS
7243                 return parse_cast();
7244         case T_IDENTIFIER:
7245                 if (is_typedef_symbol(token.v.symbol)) {
7246                         return parse_cast();
7247                 }
7248         }
7249
7250         add_anchor_token(')');
7251         expression_t *result = parse_expression();
7252         result->base.parenthesized = true;
7253         rem_anchor_token(')');
7254         expect(')', end_error);
7255
7256 end_error:
7257         return result;
7258 }
7259
7260 static expression_t *parse_function_keyword(void)
7261 {
7262         /* TODO */
7263
7264         if (current_function == NULL) {
7265                 errorf(HERE, "'__func__' used outside of a function");
7266         }
7267
7268         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7269         expression->base.type     = type_char_ptr;
7270         expression->funcname.kind = FUNCNAME_FUNCTION;
7271
7272         next_token();
7273
7274         return expression;
7275 }
7276
7277 static expression_t *parse_pretty_function_keyword(void)
7278 {
7279         if (current_function == NULL) {
7280                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7281         }
7282
7283         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7284         expression->base.type     = type_char_ptr;
7285         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7286
7287         eat(T___PRETTY_FUNCTION__);
7288
7289         return expression;
7290 }
7291
7292 static expression_t *parse_funcsig_keyword(void)
7293 {
7294         if (current_function == NULL) {
7295                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7296         }
7297
7298         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7299         expression->base.type     = type_char_ptr;
7300         expression->funcname.kind = FUNCNAME_FUNCSIG;
7301
7302         eat(T___FUNCSIG__);
7303
7304         return expression;
7305 }
7306
7307 static expression_t *parse_funcdname_keyword(void)
7308 {
7309         if (current_function == NULL) {
7310                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7311         }
7312
7313         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7314         expression->base.type     = type_char_ptr;
7315         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7316
7317         eat(T___FUNCDNAME__);
7318
7319         return expression;
7320 }
7321
7322 static designator_t *parse_designator(void)
7323 {
7324         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7325         result->source_position = *HERE;
7326
7327         if (token.type != T_IDENTIFIER) {
7328                 parse_error_expected("while parsing member designator",
7329                                      T_IDENTIFIER, NULL);
7330                 return NULL;
7331         }
7332         result->symbol = token.v.symbol;
7333         next_token();
7334
7335         designator_t *last_designator = result;
7336         while (true) {
7337                 if (token.type == '.') {
7338                         next_token();
7339                         if (token.type != T_IDENTIFIER) {
7340                                 parse_error_expected("while parsing member designator",
7341                                                      T_IDENTIFIER, NULL);
7342                                 return NULL;
7343                         }
7344                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7345                         designator->source_position = *HERE;
7346                         designator->symbol          = token.v.symbol;
7347                         next_token();
7348
7349                         last_designator->next = designator;
7350                         last_designator       = designator;
7351                         continue;
7352                 }
7353                 if (token.type == '[') {
7354                         next_token();
7355                         add_anchor_token(']');
7356                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7357                         designator->source_position = *HERE;
7358                         designator->array_index     = parse_expression();
7359                         rem_anchor_token(']');
7360                         expect(']', end_error);
7361                         if (designator->array_index == NULL) {
7362                                 return NULL;
7363                         }
7364
7365                         last_designator->next = designator;
7366                         last_designator       = designator;
7367                         continue;
7368                 }
7369                 break;
7370         }
7371
7372         return result;
7373 end_error:
7374         return NULL;
7375 }
7376
7377 /**
7378  * Parse the __builtin_offsetof() expression.
7379  */
7380 static expression_t *parse_offsetof(void)
7381 {
7382         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7383         expression->base.type    = type_size_t;
7384
7385         eat(T___builtin_offsetof);
7386
7387         expect('(', end_error);
7388         add_anchor_token(',');
7389         type_t *type = parse_typename();
7390         rem_anchor_token(',');
7391         expect(',', end_error);
7392         add_anchor_token(')');
7393         designator_t *designator = parse_designator();
7394         rem_anchor_token(')');
7395         expect(')', end_error);
7396
7397         expression->offsetofe.type       = type;
7398         expression->offsetofe.designator = designator;
7399
7400         type_path_t path;
7401         memset(&path, 0, sizeof(path));
7402         path.top_type = type;
7403         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7404
7405         descend_into_subtype(&path);
7406
7407         if (!walk_designator(&path, designator, true)) {
7408                 return create_invalid_expression();
7409         }
7410
7411         DEL_ARR_F(path.path);
7412
7413         return expression;
7414 end_error:
7415         return create_invalid_expression();
7416 }
7417
7418 /**
7419  * Parses a _builtin_va_start() expression.
7420  */
7421 static expression_t *parse_va_start(void)
7422 {
7423         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7424
7425         eat(T___builtin_va_start);
7426
7427         expect('(', end_error);
7428         add_anchor_token(',');
7429         expression->va_starte.ap = parse_assignment_expression();
7430         rem_anchor_token(',');
7431         expect(',', end_error);
7432         expression_t *const expr = parse_assignment_expression();
7433         if (expr->kind == EXPR_REFERENCE) {
7434                 entity_t *const entity = expr->reference.entity;
7435                 if (entity->base.parent_scope != &current_function->parameters
7436                                 || entity->base.next != NULL
7437                                 || entity->kind != ENTITY_PARAMETER) {
7438                         errorf(&expr->base.source_position,
7439                                "second argument of 'va_start' must be last parameter of the current function");
7440                 } else {
7441                         expression->va_starte.parameter = &entity->variable;
7442                 }
7443                 expect(')', end_error);
7444                 return expression;
7445         }
7446         expect(')', end_error);
7447 end_error:
7448         return create_invalid_expression();
7449 }
7450
7451 /**
7452  * Parses a _builtin_va_arg() expression.
7453  */
7454 static expression_t *parse_va_arg(void)
7455 {
7456         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7457
7458         eat(T___builtin_va_arg);
7459
7460         expect('(', end_error);
7461         expression->va_arge.ap = parse_assignment_expression();
7462         expect(',', end_error);
7463         expression->base.type = parse_typename();
7464         expect(')', end_error);
7465
7466         return expression;
7467 end_error:
7468         return create_invalid_expression();
7469 }
7470
7471 static expression_t *parse_builtin_symbol(void)
7472 {
7473         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7474
7475         symbol_t *symbol = token.v.symbol;
7476
7477         expression->builtin_symbol.symbol = symbol;
7478         next_token();
7479
7480         type_t *type = get_builtin_symbol_type(symbol);
7481         type = automatic_type_conversion(type);
7482
7483         expression->base.type = type;
7484         return expression;
7485 }
7486
7487 /**
7488  * Parses a __builtin_constant() expression.
7489  */
7490 static expression_t *parse_builtin_constant(void)
7491 {
7492         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7493
7494         eat(T___builtin_constant_p);
7495
7496         expect('(', end_error);
7497         add_anchor_token(')');
7498         expression->builtin_constant.value = parse_assignment_expression();
7499         rem_anchor_token(')');
7500         expect(')', end_error);
7501         expression->base.type = type_int;
7502
7503         return expression;
7504 end_error:
7505         return create_invalid_expression();
7506 }
7507
7508 /**
7509  * Parses a __builtin_prefetch() expression.
7510  */
7511 static expression_t *parse_builtin_prefetch(void)
7512 {
7513         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7514
7515         eat(T___builtin_prefetch);
7516
7517         expect('(', end_error);
7518         add_anchor_token(')');
7519         expression->builtin_prefetch.adr = parse_assignment_expression();
7520         if (token.type == ',') {
7521                 next_token();
7522                 expression->builtin_prefetch.rw = parse_assignment_expression();
7523         }
7524         if (token.type == ',') {
7525                 next_token();
7526                 expression->builtin_prefetch.locality = parse_assignment_expression();
7527         }
7528         rem_anchor_token(')');
7529         expect(')', end_error);
7530         expression->base.type = type_void;
7531
7532         return expression;
7533 end_error:
7534         return create_invalid_expression();
7535 }
7536
7537 /**
7538  * Parses a __builtin_is_*() compare expression.
7539  */
7540 static expression_t *parse_compare_builtin(void)
7541 {
7542         expression_t *expression;
7543
7544         switch (token.type) {
7545         case T___builtin_isgreater:
7546                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7547                 break;
7548         case T___builtin_isgreaterequal:
7549                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7550                 break;
7551         case T___builtin_isless:
7552                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7553                 break;
7554         case T___builtin_islessequal:
7555                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7556                 break;
7557         case T___builtin_islessgreater:
7558                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7559                 break;
7560         case T___builtin_isunordered:
7561                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7562                 break;
7563         default:
7564                 internal_errorf(HERE, "invalid compare builtin found");
7565         }
7566         expression->base.source_position = *HERE;
7567         next_token();
7568
7569         expect('(', end_error);
7570         expression->binary.left = parse_assignment_expression();
7571         expect(',', end_error);
7572         expression->binary.right = parse_assignment_expression();
7573         expect(')', end_error);
7574
7575         type_t *const orig_type_left  = expression->binary.left->base.type;
7576         type_t *const orig_type_right = expression->binary.right->base.type;
7577
7578         type_t *const type_left  = skip_typeref(orig_type_left);
7579         type_t *const type_right = skip_typeref(orig_type_right);
7580         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7581                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7582                         type_error_incompatible("invalid operands in comparison",
7583                                 &expression->base.source_position, orig_type_left, orig_type_right);
7584                 }
7585         } else {
7586                 semantic_comparison(&expression->binary);
7587         }
7588
7589         return expression;
7590 end_error:
7591         return create_invalid_expression();
7592 }
7593
7594 #if 0
7595 /**
7596  * Parses a __builtin_expect(, end_error) expression.
7597  */
7598 static expression_t *parse_builtin_expect(void, end_error)
7599 {
7600         expression_t *expression
7601                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7602
7603         eat(T___builtin_expect);
7604
7605         expect('(', end_error);
7606         expression->binary.left = parse_assignment_expression();
7607         expect(',', end_error);
7608         expression->binary.right = parse_constant_expression();
7609         expect(')', end_error);
7610
7611         expression->base.type = expression->binary.left->base.type;
7612
7613         return expression;
7614 end_error:
7615         return create_invalid_expression();
7616 }
7617 #endif
7618
7619 /**
7620  * Parses a MS assume() expression.
7621  */
7622 static expression_t *parse_assume(void)
7623 {
7624         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7625
7626         eat(T__assume);
7627
7628         expect('(', end_error);
7629         add_anchor_token(')');
7630         expression->unary.value = parse_assignment_expression();
7631         rem_anchor_token(')');
7632         expect(')', end_error);
7633
7634         expression->base.type = type_void;
7635         return expression;
7636 end_error:
7637         return create_invalid_expression();
7638 }
7639
7640 /**
7641  * Return the declaration for a given label symbol or create a new one.
7642  *
7643  * @param symbol  the symbol of the label
7644  */
7645 static label_t *get_label(symbol_t *symbol)
7646 {
7647         entity_t *label;
7648         assert(current_function != NULL);
7649
7650         label = get_entity(symbol, NAMESPACE_LABEL);
7651         /* if we found a local label, we already created the declaration */
7652         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7653                 if (label->base.parent_scope != current_scope) {
7654                         assert(label->base.parent_scope->depth < current_scope->depth);
7655                         current_function->goto_to_outer = true;
7656                 }
7657                 return &label->label;
7658         }
7659
7660         label = get_entity(symbol, NAMESPACE_LABEL);
7661         /* if we found a label in the same function, then we already created the
7662          * declaration */
7663         if (label != NULL
7664                         && label->base.parent_scope == &current_function->parameters) {
7665                 return &label->label;
7666         }
7667
7668         /* otherwise we need to create a new one */
7669         label               = allocate_entity_zero(ENTITY_LABEL);
7670         label->base.namespc = NAMESPACE_LABEL;
7671         label->base.symbol  = symbol;
7672
7673         label_push(label);
7674
7675         return &label->label;
7676 }
7677
7678 /**
7679  * Parses a GNU && label address expression.
7680  */
7681 static expression_t *parse_label_address(void)
7682 {
7683         source_position_t source_position = token.source_position;
7684         eat(T_ANDAND);
7685         if (token.type != T_IDENTIFIER) {
7686                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7687                 goto end_error;
7688         }
7689         symbol_t *symbol = token.v.symbol;
7690         next_token();
7691
7692         label_t *label       = get_label(symbol);
7693         label->used          = true;
7694         label->address_taken = true;
7695
7696         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7697         expression->base.source_position = source_position;
7698
7699         /* label address is threaten as a void pointer */
7700         expression->base.type           = type_void_ptr;
7701         expression->label_address.label = label;
7702         return expression;
7703 end_error:
7704         return create_invalid_expression();
7705 }
7706
7707 /**
7708  * Parse a microsoft __noop expression.
7709  */
7710 static expression_t *parse_noop_expression(void)
7711 {
7712         /* the result is a (int)0 */
7713         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7714         cnst->base.type            = type_int;
7715         cnst->conste.v.int_value   = 0;
7716         cnst->conste.is_ms_noop    = true;
7717
7718         eat(T___noop);
7719
7720         if (token.type == '(') {
7721                 /* parse arguments */
7722                 eat('(');
7723                 add_anchor_token(')');
7724                 add_anchor_token(',');
7725
7726                 if (token.type != ')') {
7727                         while (true) {
7728                                 (void)parse_assignment_expression();
7729                                 if (token.type != ',')
7730                                         break;
7731                                 next_token();
7732                         }
7733                 }
7734         }
7735         rem_anchor_token(',');
7736         rem_anchor_token(')');
7737         expect(')', end_error);
7738
7739 end_error:
7740         return cnst;
7741 }
7742
7743 /**
7744  * Parses a primary expression.
7745  */
7746 static expression_t *parse_primary_expression(void)
7747 {
7748         switch (token.type) {
7749                 case T_false:                    return parse_bool_const(false);
7750                 case T_true:                     return parse_bool_const(true);
7751                 case T_INTEGER:                  return parse_int_const();
7752                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7753                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7754                 case T_FLOATINGPOINT:            return parse_float_const();
7755                 case T_STRING_LITERAL:
7756                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7757                 case T_IDENTIFIER:               return parse_reference();
7758                 case T___FUNCTION__:
7759                 case T___func__:                 return parse_function_keyword();
7760                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7761                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7762                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7763                 case T___builtin_offsetof:       return parse_offsetof();
7764                 case T___builtin_va_start:       return parse_va_start();
7765                 case T___builtin_va_arg:         return parse_va_arg();
7766                 case T___builtin_expect:
7767                 case T___builtin_alloca:
7768                 case T___builtin_inf:
7769                 case T___builtin_inff:
7770                 case T___builtin_infl:
7771                 case T___builtin_nan:
7772                 case T___builtin_nanf:
7773                 case T___builtin_nanl:
7774                 case T___builtin_huge_val:
7775                 case T___builtin_va_end:         return parse_builtin_symbol();
7776                 case T___builtin_isgreater:
7777                 case T___builtin_isgreaterequal:
7778                 case T___builtin_isless:
7779                 case T___builtin_islessequal:
7780                 case T___builtin_islessgreater:
7781                 case T___builtin_isunordered:    return parse_compare_builtin();
7782                 case T___builtin_constant_p:     return parse_builtin_constant();
7783                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7784                 case T__assume:                  return parse_assume();
7785                 case T_ANDAND:
7786                         if (GNU_MODE)
7787                                 return parse_label_address();
7788                         break;
7789
7790                 case '(':                        return parse_parenthesized_expression();
7791                 case T___noop:                   return parse_noop_expression();
7792         }
7793
7794         errorf(HERE, "unexpected token %K, expected an expression", &token);
7795         return create_invalid_expression();
7796 }
7797
7798 /**
7799  * Check if the expression has the character type and issue a warning then.
7800  */
7801 static void check_for_char_index_type(const expression_t *expression)
7802 {
7803         type_t       *const type      = expression->base.type;
7804         const type_t *const base_type = skip_typeref(type);
7805
7806         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7807                         warning.char_subscripts) {
7808                 warningf(&expression->base.source_position,
7809                          "array subscript has type '%T'", type);
7810         }
7811 }
7812
7813 static expression_t *parse_array_expression(expression_t *left)
7814 {
7815         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7816
7817         eat('[');
7818         add_anchor_token(']');
7819
7820         expression_t *inside = parse_expression();
7821
7822         type_t *const orig_type_left   = left->base.type;
7823         type_t *const orig_type_inside = inside->base.type;
7824
7825         type_t *const type_left   = skip_typeref(orig_type_left);
7826         type_t *const type_inside = skip_typeref(orig_type_inside);
7827
7828         type_t                    *return_type;
7829         array_access_expression_t *array_access = &expression->array_access;
7830         if (is_type_pointer(type_left)) {
7831                 return_type             = type_left->pointer.points_to;
7832                 array_access->array_ref = left;
7833                 array_access->index     = inside;
7834                 check_for_char_index_type(inside);
7835         } else if (is_type_pointer(type_inside)) {
7836                 return_type             = type_inside->pointer.points_to;
7837                 array_access->array_ref = inside;
7838                 array_access->index     = left;
7839                 array_access->flipped   = true;
7840                 check_for_char_index_type(left);
7841         } else {
7842                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7843                         errorf(HERE,
7844                                 "array access on object with non-pointer types '%T', '%T'",
7845                                 orig_type_left, orig_type_inside);
7846                 }
7847                 return_type             = type_error_type;
7848                 array_access->array_ref = left;
7849                 array_access->index     = inside;
7850         }
7851
7852         expression->base.type = automatic_type_conversion(return_type);
7853
7854         rem_anchor_token(']');
7855         expect(']', end_error);
7856 end_error:
7857         return expression;
7858 }
7859
7860 static expression_t *parse_typeprop(expression_kind_t const kind)
7861 {
7862         expression_t  *tp_expression = allocate_expression_zero(kind);
7863         tp_expression->base.type     = type_size_t;
7864
7865         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7866
7867         /* we only refer to a type property, mark this case */
7868         bool old     = in_type_prop;
7869         in_type_prop = true;
7870
7871         type_t       *orig_type;
7872         expression_t *expression;
7873         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7874                 next_token();
7875                 add_anchor_token(')');
7876                 orig_type = parse_typename();
7877                 rem_anchor_token(')');
7878                 expect(')', end_error);
7879
7880                 if (token.type == '{') {
7881                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7882                          * starting with a compound literal */
7883                         expression = parse_compound_literal(orig_type);
7884                         goto typeprop_expression;
7885                 }
7886         } else {
7887                 expression = parse_sub_expression(PREC_UNARY);
7888
7889 typeprop_expression:
7890                 tp_expression->typeprop.tp_expression = expression;
7891
7892                 orig_type = revert_automatic_type_conversion(expression);
7893                 expression->base.type = orig_type;
7894         }
7895
7896         tp_expression->typeprop.type   = orig_type;
7897         type_t const* const type       = skip_typeref(orig_type);
7898         char   const* const wrong_type =
7899                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7900                 is_type_incomplete(type)                           ? "incomplete"          :
7901                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7902                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7903                 NULL;
7904         if (wrong_type != NULL) {
7905                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7906                 errorf(&tp_expression->base.source_position,
7907                                 "operand of %s expression must not be of %s type '%T'",
7908                                 what, wrong_type, orig_type);
7909         }
7910
7911 end_error:
7912         in_type_prop = old;
7913         return tp_expression;
7914 }
7915
7916 static expression_t *parse_sizeof(void)
7917 {
7918         return parse_typeprop(EXPR_SIZEOF);
7919 }
7920
7921 static expression_t *parse_alignof(void)
7922 {
7923         return parse_typeprop(EXPR_ALIGNOF);
7924 }
7925
7926 static expression_t *parse_select_expression(expression_t *compound)
7927 {
7928         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7929         select->select.compound = compound;
7930
7931         assert(token.type == '.' || token.type == T_MINUSGREATER);
7932         bool is_pointer = (token.type == T_MINUSGREATER);
7933         next_token();
7934
7935         if (token.type != T_IDENTIFIER) {
7936                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7937                 return select;
7938         }
7939         symbol_t *symbol = token.v.symbol;
7940         next_token();
7941
7942         type_t *const orig_type = compound->base.type;
7943         type_t *const type      = skip_typeref(orig_type);
7944
7945         type_t *type_left;
7946         bool    saw_error = false;
7947         if (is_type_pointer(type)) {
7948                 if (!is_pointer) {
7949                         errorf(HERE,
7950                                "request for member '%Y' in something not a struct or union, but '%T'",
7951                                symbol, orig_type);
7952                         saw_error = true;
7953                 }
7954                 type_left = skip_typeref(type->pointer.points_to);
7955         } else {
7956                 if (is_pointer && is_type_valid(type)) {
7957                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7958                         saw_error = true;
7959                 }
7960                 type_left = type;
7961         }
7962
7963         entity_t *entry;
7964         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7965             type_left->kind == TYPE_COMPOUND_UNION) {
7966                 compound_t *compound = type_left->compound.compound;
7967
7968                 if (!compound->complete) {
7969                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7970                                symbol, type_left);
7971                         goto create_error_entry;
7972                 }
7973
7974                 entry = find_compound_entry(compound, symbol);
7975                 if (entry == NULL) {
7976                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7977                         goto create_error_entry;
7978                 }
7979         } else {
7980                 if (is_type_valid(type_left) && !saw_error) {
7981                         errorf(HERE,
7982                                "request for member '%Y' in something not a struct or union, but '%T'",
7983                                symbol, type_left);
7984                 }
7985 create_error_entry:
7986                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7987         }
7988
7989         assert(is_declaration(entry));
7990         select->select.compound_entry = entry;
7991
7992         type_t *entry_type = entry->declaration.type;
7993         type_t *res_type
7994                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7995
7996         /* we always do the auto-type conversions; the & and sizeof parser contains
7997          * code to revert this! */
7998         select->base.type = automatic_type_conversion(res_type);
7999
8000         type_t *skipped = skip_typeref(res_type);
8001         if (skipped->kind == TYPE_BITFIELD) {
8002                 select->base.type = skipped->bitfield.base_type;
8003         }
8004
8005         return select;
8006 }
8007
8008 static void check_call_argument(const function_parameter_t *parameter,
8009                                 call_argument_t *argument, unsigned pos)
8010 {
8011         type_t         *expected_type      = parameter->type;
8012         type_t         *expected_type_skip = skip_typeref(expected_type);
8013         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8014         expression_t   *arg_expr           = argument->expression;
8015         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8016
8017         /* handle transparent union gnu extension */
8018         if (is_type_union(expected_type_skip)
8019                         && (expected_type_skip->base.modifiers
8020                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8021                 compound_t *union_decl  = expected_type_skip->compound.compound;
8022                 type_t     *best_type   = NULL;
8023                 entity_t   *entry       = union_decl->members.entities;
8024                 for ( ; entry != NULL; entry = entry->base.next) {
8025                         assert(is_declaration(entry));
8026                         type_t *decl_type = entry->declaration.type;
8027                         error = semantic_assign(decl_type, arg_expr);
8028                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8029                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8030                                 continue;
8031
8032                         if (error == ASSIGN_SUCCESS) {
8033                                 best_type = decl_type;
8034                         } else if (best_type == NULL) {
8035                                 best_type = decl_type;
8036                         }
8037                 }
8038
8039                 if (best_type != NULL) {
8040                         expected_type = best_type;
8041                 }
8042         }
8043
8044         error                = semantic_assign(expected_type, arg_expr);
8045         argument->expression = create_implicit_cast(argument->expression,
8046                                                     expected_type);
8047
8048         if (error != ASSIGN_SUCCESS) {
8049                 /* report exact scope in error messages (like "in argument 3") */
8050                 char buf[64];
8051                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8052                 report_assign_error(error, expected_type, arg_expr,     buf,
8053                                                         &arg_expr->base.source_position);
8054         } else if (warning.traditional || warning.conversion) {
8055                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8056                 if (!types_compatible(expected_type_skip, promoted_type) &&
8057                     !types_compatible(expected_type_skip, type_void_ptr) &&
8058                     !types_compatible(type_void_ptr,      promoted_type)) {
8059                         /* Deliberately show the skipped types in this warning */
8060                         warningf(&arg_expr->base.source_position,
8061                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8062                                 pos, expected_type_skip, promoted_type);
8063                 }
8064         }
8065 }
8066
8067 /**
8068  * Parse a call expression, ie. expression '( ... )'.
8069  *
8070  * @param expression  the function address
8071  */
8072 static expression_t *parse_call_expression(expression_t *expression)
8073 {
8074         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8075         call_expression_t *call   = &result->call;
8076         call->function            = expression;
8077
8078         type_t *const orig_type = expression->base.type;
8079         type_t *const type      = skip_typeref(orig_type);
8080
8081         function_type_t *function_type = NULL;
8082         if (is_type_pointer(type)) {
8083                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8084
8085                 if (is_type_function(to_type)) {
8086                         function_type   = &to_type->function;
8087                         call->base.type = function_type->return_type;
8088                 }
8089         }
8090
8091         if (function_type == NULL && is_type_valid(type)) {
8092                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8093         }
8094
8095         /* parse arguments */
8096         eat('(');
8097         add_anchor_token(')');
8098         add_anchor_token(',');
8099
8100         if (token.type != ')') {
8101                 call_argument_t *last_argument = NULL;
8102
8103                 while (true) {
8104                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8105
8106                         argument->expression = parse_assignment_expression();
8107                         if (last_argument == NULL) {
8108                                 call->arguments = argument;
8109                         } else {
8110                                 last_argument->next = argument;
8111                         }
8112                         last_argument = argument;
8113
8114                         if (token.type != ',')
8115                                 break;
8116                         next_token();
8117                 }
8118         }
8119         rem_anchor_token(',');
8120         rem_anchor_token(')');
8121         expect(')', end_error);
8122
8123         if (function_type == NULL)
8124                 return result;
8125
8126         function_parameter_t *parameter = function_type->parameters;
8127         call_argument_t      *argument  = call->arguments;
8128         if (!function_type->unspecified_parameters) {
8129                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8130                                 parameter = parameter->next, argument = argument->next) {
8131                         check_call_argument(parameter, argument, ++pos);
8132                 }
8133
8134                 if (parameter != NULL) {
8135                         errorf(HERE, "too few arguments to function '%E'", expression);
8136                 } else if (argument != NULL && !function_type->variadic) {
8137                         errorf(HERE, "too many arguments to function '%E'", expression);
8138                 }
8139         }
8140
8141         /* do default promotion */
8142         for (; argument != NULL; argument = argument->next) {
8143                 type_t *type = argument->expression->base.type;
8144
8145                 type = get_default_promoted_type(type);
8146
8147                 argument->expression
8148                         = create_implicit_cast(argument->expression, type);
8149         }
8150
8151         check_format(&result->call);
8152
8153         if (warning.aggregate_return &&
8154             is_type_compound(skip_typeref(function_type->return_type))) {
8155                 warningf(&result->base.source_position,
8156                          "function call has aggregate value");
8157         }
8158
8159 end_error:
8160         return result;
8161 }
8162
8163 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8164
8165 static bool same_compound_type(const type_t *type1, const type_t *type2)
8166 {
8167         return
8168                 is_type_compound(type1) &&
8169                 type1->kind == type2->kind &&
8170                 type1->compound.compound == type2->compound.compound;
8171 }
8172
8173 static expression_t const *get_reference_address(expression_t const *expr)
8174 {
8175         bool regular_take_address = true;
8176         for (;;) {
8177                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8178                         expr = expr->unary.value;
8179                 } else {
8180                         regular_take_address = false;
8181                 }
8182
8183                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8184                         break;
8185
8186                 expr = expr->unary.value;
8187         }
8188
8189         if (expr->kind != EXPR_REFERENCE)
8190                 return NULL;
8191
8192         /* special case for functions which are automatically converted to a
8193          * pointer to function without an extra TAKE_ADDRESS operation */
8194         if (!regular_take_address &&
8195                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8196                 return NULL;
8197         }
8198
8199         return expr;
8200 }
8201
8202 static void warn_reference_address_as_bool(expression_t const* expr)
8203 {
8204         if (!warning.address)
8205                 return;
8206
8207         expr = get_reference_address(expr);
8208         if (expr != NULL) {
8209                 warningf(&expr->base.source_position,
8210                          "the address of '%Y' will always evaluate as 'true'",
8211                          expr->reference.entity->base.symbol);
8212         }
8213 }
8214
8215 static void warn_assignment_in_condition(const expression_t *const expr)
8216 {
8217         if (!warning.parentheses)
8218                 return;
8219         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8220                 return;
8221         if (expr->base.parenthesized)
8222                 return;
8223         warningf(&expr->base.source_position,
8224                         "suggest parentheses around assignment used as truth value");
8225 }
8226
8227 static void semantic_condition(expression_t const *const expr,
8228                                char const *const context)
8229 {
8230         type_t *const type = skip_typeref(expr->base.type);
8231         if (is_type_scalar(type)) {
8232                 warn_reference_address_as_bool(expr);
8233                 warn_assignment_in_condition(expr);
8234         } else if (is_type_valid(type)) {
8235                 errorf(&expr->base.source_position,
8236                                 "%s must have scalar type", context);
8237         }
8238 }
8239
8240 /**
8241  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8242  *
8243  * @param expression  the conditional expression
8244  */
8245 static expression_t *parse_conditional_expression(expression_t *expression)
8246 {
8247         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8248
8249         conditional_expression_t *conditional = &result->conditional;
8250         conditional->condition                = expression;
8251
8252         eat('?');
8253         add_anchor_token(':');
8254
8255         /* Â§6.5.15:2  The first operand shall have scalar type. */
8256         semantic_condition(expression, "condition of conditional operator");
8257
8258         expression_t *true_expression = expression;
8259         bool          gnu_cond = false;
8260         if (GNU_MODE && token.type == ':') {
8261                 gnu_cond = true;
8262         } else {
8263                 true_expression = parse_expression();
8264         }
8265         rem_anchor_token(':');
8266         expect(':', end_error);
8267 end_error:;
8268         expression_t *false_expression =
8269                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8270
8271         type_t *const orig_true_type  = true_expression->base.type;
8272         type_t *const orig_false_type = false_expression->base.type;
8273         type_t *const true_type       = skip_typeref(orig_true_type);
8274         type_t *const false_type      = skip_typeref(orig_false_type);
8275
8276         /* 6.5.15.3 */
8277         type_t *result_type;
8278         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8279                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8280                 /* ISO/IEC 14882:1998(E) Â§5.16:2 */
8281                 if (true_expression->kind == EXPR_UNARY_THROW) {
8282                         result_type = false_type;
8283                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8284                         result_type = true_type;
8285                 } else {
8286                         if (warning.other && (
8287                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8288                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8289                                         )) {
8290                                 warningf(&conditional->base.source_position,
8291                                                 "ISO C forbids conditional expression with only one void side");
8292                         }
8293                         result_type = type_void;
8294                 }
8295         } else if (is_type_arithmetic(true_type)
8296                    && is_type_arithmetic(false_type)) {
8297                 result_type = semantic_arithmetic(true_type, false_type);
8298
8299                 true_expression  = create_implicit_cast(true_expression, result_type);
8300                 false_expression = create_implicit_cast(false_expression, result_type);
8301
8302                 conditional->true_expression  = true_expression;
8303                 conditional->false_expression = false_expression;
8304                 conditional->base.type        = result_type;
8305         } else if (same_compound_type(true_type, false_type)) {
8306                 /* just take 1 of the 2 types */
8307                 result_type = true_type;
8308         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8309                 type_t *pointer_type;
8310                 type_t *other_type;
8311                 expression_t *other_expression;
8312                 if (is_type_pointer(true_type) &&
8313                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8314                         pointer_type     = true_type;
8315                         other_type       = false_type;
8316                         other_expression = false_expression;
8317                 } else {
8318                         pointer_type     = false_type;
8319                         other_type       = true_type;
8320                         other_expression = true_expression;
8321                 }
8322
8323                 if (is_null_pointer_constant(other_expression)) {
8324                         result_type = pointer_type;
8325                 } else if (is_type_pointer(other_type)) {
8326                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8327                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8328
8329                         type_t *to;
8330                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8331                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8332                                 to = type_void;
8333                         } else if (types_compatible(get_unqualified_type(to1),
8334                                                     get_unqualified_type(to2))) {
8335                                 to = to1;
8336                         } else {
8337                                 if (warning.other) {
8338                                         warningf(&conditional->base.source_position,
8339                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8340                                                         true_type, false_type);
8341                                 }
8342                                 to = type_void;
8343                         }
8344
8345                         type_t *const type =
8346                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8347                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8348                 } else if (is_type_integer(other_type)) {
8349                         if (warning.other) {
8350                                 warningf(&conditional->base.source_position,
8351                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8352                         }
8353                         result_type = pointer_type;
8354                 } else {
8355                         if (is_type_valid(other_type)) {
8356                                 type_error_incompatible("while parsing conditional",
8357                                                 &expression->base.source_position, true_type, false_type);
8358                         }
8359                         result_type = type_error_type;
8360                 }
8361         } else {
8362                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8363                         type_error_incompatible("while parsing conditional",
8364                                                 &conditional->base.source_position, true_type,
8365                                                 false_type);
8366                 }
8367                 result_type = type_error_type;
8368         }
8369
8370         conditional->true_expression
8371                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8372         conditional->false_expression
8373                 = create_implicit_cast(false_expression, result_type);
8374         conditional->base.type = result_type;
8375         return result;
8376 }
8377
8378 /**
8379  * Parse an extension expression.
8380  */
8381 static expression_t *parse_extension(void)
8382 {
8383         eat(T___extension__);
8384
8385         bool old_gcc_extension   = in_gcc_extension;
8386         in_gcc_extension         = true;
8387         expression_t *expression = parse_sub_expression(PREC_UNARY);
8388         in_gcc_extension         = old_gcc_extension;
8389         return expression;
8390 }
8391
8392 /**
8393  * Parse a __builtin_classify_type() expression.
8394  */
8395 static expression_t *parse_builtin_classify_type(void)
8396 {
8397         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8398         result->base.type    = type_int;
8399
8400         eat(T___builtin_classify_type);
8401
8402         expect('(', end_error);
8403         add_anchor_token(')');
8404         expression_t *expression = parse_expression();
8405         rem_anchor_token(')');
8406         expect(')', end_error);
8407         result->classify_type.type_expression = expression;
8408
8409         return result;
8410 end_error:
8411         return create_invalid_expression();
8412 }
8413
8414 /**
8415  * Parse a delete expression
8416  * ISO/IEC 14882:1998(E) Â§5.3.5
8417  */
8418 static expression_t *parse_delete(void)
8419 {
8420         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8421         result->base.type          = type_void;
8422
8423         eat(T_delete);
8424
8425         if (token.type == '[') {
8426                 next_token();
8427                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8428                 expect(']', end_error);
8429 end_error:;
8430         }
8431
8432         expression_t *const value = parse_sub_expression(PREC_CAST);
8433         result->unary.value = value;
8434
8435         type_t *const type = skip_typeref(value->base.type);
8436         if (!is_type_pointer(type)) {
8437                 errorf(&value->base.source_position,
8438                                 "operand of delete must have pointer type");
8439         } else if (warning.other &&
8440                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8441                 warningf(&value->base.source_position,
8442                                 "deleting 'void*' is undefined");
8443         }
8444
8445         return result;
8446 }
8447
8448 /**
8449  * Parse a throw expression
8450  * ISO/IEC 14882:1998(E) Â§15:1
8451  */
8452 static expression_t *parse_throw(void)
8453 {
8454         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8455         result->base.type          = type_void;
8456
8457         eat(T_throw);
8458
8459         expression_t *value = NULL;
8460         switch (token.type) {
8461                 EXPRESSION_START {
8462                         value = parse_assignment_expression();
8463                         /* ISO/IEC 14882:1998(E) Â§15.1:3 */
8464                         type_t *const orig_type = value->base.type;
8465                         type_t *const type      = skip_typeref(orig_type);
8466                         if (is_type_incomplete(type)) {
8467                                 errorf(&value->base.source_position,
8468                                                 "cannot throw object of incomplete type '%T'", orig_type);
8469                         } else if (is_type_pointer(type)) {
8470                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8471                                 if (is_type_incomplete(points_to) &&
8472                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8473                                         errorf(&value->base.source_position,
8474                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8475                                 }
8476                         }
8477                 }
8478
8479                 default:
8480                         break;
8481         }
8482         result->unary.value = value;
8483
8484         return result;
8485 }
8486
8487 static bool check_pointer_arithmetic(const source_position_t *source_position,
8488                                      type_t *pointer_type,
8489                                      type_t *orig_pointer_type)
8490 {
8491         type_t *points_to = pointer_type->pointer.points_to;
8492         points_to = skip_typeref(points_to);
8493
8494         if (is_type_incomplete(points_to)) {
8495                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8496                         errorf(source_position,
8497                                "arithmetic with pointer to incomplete type '%T' not allowed",
8498                                orig_pointer_type);
8499                         return false;
8500                 } else if (warning.pointer_arith) {
8501                         warningf(source_position,
8502                                  "pointer of type '%T' used in arithmetic",
8503                                  orig_pointer_type);
8504                 }
8505         } else if (is_type_function(points_to)) {
8506                 if (!GNU_MODE) {
8507                         errorf(source_position,
8508                                "arithmetic with pointer to function type '%T' not allowed",
8509                                orig_pointer_type);
8510                         return false;
8511                 } else if (warning.pointer_arith) {
8512                         warningf(source_position,
8513                                  "pointer to a function '%T' used in arithmetic",
8514                                  orig_pointer_type);
8515                 }
8516         }
8517         return true;
8518 }
8519
8520 static bool is_lvalue(const expression_t *expression)
8521 {
8522         /* TODO: doesn't seem to be consistent with Â§6.3.2.1 (1) */
8523         switch (expression->kind) {
8524         case EXPR_ARRAY_ACCESS:
8525         case EXPR_COMPOUND_LITERAL:
8526         case EXPR_REFERENCE:
8527         case EXPR_SELECT:
8528         case EXPR_UNARY_DEREFERENCE:
8529                 return true;
8530
8531         default: {
8532           type_t *type = skip_typeref(expression->base.type);
8533           return
8534                 /* ISO/IEC 14882:1998(E) Â§3.10:3 */
8535                 is_type_reference(type) ||
8536                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8537                  * error before, which maybe prevented properly recognizing it as
8538                  * lvalue. */
8539                 !is_type_valid(type);
8540         }
8541         }
8542 }
8543
8544 static void semantic_incdec(unary_expression_t *expression)
8545 {
8546         type_t *const orig_type = expression->value->base.type;
8547         type_t *const type      = skip_typeref(orig_type);
8548         if (is_type_pointer(type)) {
8549                 if (!check_pointer_arithmetic(&expression->base.source_position,
8550                                               type, orig_type)) {
8551                         return;
8552                 }
8553         } else if (!is_type_real(type) && is_type_valid(type)) {
8554                 /* TODO: improve error message */
8555                 errorf(&expression->base.source_position,
8556                        "operation needs an arithmetic or pointer type");
8557                 return;
8558         }
8559         if (!is_lvalue(expression->value)) {
8560                 /* TODO: improve error message */
8561                 errorf(&expression->base.source_position, "lvalue required as operand");
8562         }
8563         expression->base.type = orig_type;
8564 }
8565
8566 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8567 {
8568         type_t *const orig_type = expression->value->base.type;
8569         type_t *const type      = skip_typeref(orig_type);
8570         if (!is_type_arithmetic(type)) {
8571                 if (is_type_valid(type)) {
8572                         /* TODO: improve error message */
8573                         errorf(&expression->base.source_position,
8574                                 "operation needs an arithmetic type");
8575                 }
8576                 return;
8577         }
8578
8579         expression->base.type = orig_type;
8580 }
8581
8582 static void semantic_unexpr_plus(unary_expression_t *expression)
8583 {
8584         semantic_unexpr_arithmetic(expression);
8585         if (warning.traditional)
8586                 warningf(&expression->base.source_position,
8587                         "traditional C rejects the unary plus operator");
8588 }
8589
8590 static void semantic_not(unary_expression_t *expression)
8591 {
8592         /* Â§6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8593         semantic_condition(expression->value, "operand of !");
8594         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8595 }
8596
8597 static void semantic_unexpr_integer(unary_expression_t *expression)
8598 {
8599         type_t *const orig_type = expression->value->base.type;
8600         type_t *const type      = skip_typeref(orig_type);
8601         if (!is_type_integer(type)) {
8602                 if (is_type_valid(type)) {
8603                         errorf(&expression->base.source_position,
8604                                "operand of ~ must be of integer type");
8605                 }
8606                 return;
8607         }
8608
8609         expression->base.type = orig_type;
8610 }
8611
8612 static void semantic_dereference(unary_expression_t *expression)
8613 {
8614         type_t *const orig_type = expression->value->base.type;
8615         type_t *const type      = skip_typeref(orig_type);
8616         if (!is_type_pointer(type)) {
8617                 if (is_type_valid(type)) {
8618                         errorf(&expression->base.source_position,
8619                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8620                 }
8621                 return;
8622         }
8623
8624         type_t *result_type   = type->pointer.points_to;
8625         result_type           = automatic_type_conversion(result_type);
8626         expression->base.type = result_type;
8627 }
8628
8629 /**
8630  * Record that an address is taken (expression represents an lvalue).
8631  *
8632  * @param expression       the expression
8633  * @param may_be_register  if true, the expression might be an register
8634  */
8635 static void set_address_taken(expression_t *expression, bool may_be_register)
8636 {
8637         if (expression->kind != EXPR_REFERENCE)
8638                 return;
8639
8640         entity_t *const entity = expression->reference.entity;
8641
8642         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8643                 return;
8644
8645         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8646                         && !may_be_register) {
8647                 errorf(&expression->base.source_position,
8648                                 "address of register %s '%Y' requested",
8649                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8650         }
8651
8652         if (entity->kind == ENTITY_VARIABLE) {
8653                 entity->variable.address_taken = true;
8654         } else {
8655                 assert(entity->kind == ENTITY_PARAMETER);
8656                 entity->parameter.address_taken = true;
8657         }
8658 }
8659
8660 /**
8661  * Check the semantic of the address taken expression.
8662  */
8663 static void semantic_take_addr(unary_expression_t *expression)
8664 {
8665         expression_t *value = expression->value;
8666         value->base.type    = revert_automatic_type_conversion(value);
8667
8668         type_t *orig_type = value->base.type;
8669         type_t *type      = skip_typeref(orig_type);
8670         if (!is_type_valid(type))
8671                 return;
8672
8673         /* Â§6.5.3.2 */
8674         if (!is_lvalue(value)) {
8675                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8676         }
8677         if (type->kind == TYPE_BITFIELD) {
8678                 errorf(&expression->base.source_position,
8679                        "'&' not allowed on object with bitfield type '%T'",
8680                        type);
8681         }
8682
8683         set_address_taken(value, false);
8684
8685         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8686 }
8687
8688 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8689 static expression_t *parse_##unexpression_type(void)                         \
8690 {                                                                            \
8691         expression_t *unary_expression                                           \
8692                 = allocate_expression_zero(unexpression_type);                       \
8693         eat(token_type);                                                         \
8694         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8695                                                                                  \
8696         sfunc(&unary_expression->unary);                                         \
8697                                                                                  \
8698         return unary_expression;                                                 \
8699 }
8700
8701 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8702                                semantic_unexpr_arithmetic)
8703 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8704                                semantic_unexpr_plus)
8705 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8706                                semantic_not)
8707 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8708                                semantic_dereference)
8709 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8710                                semantic_take_addr)
8711 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8712                                semantic_unexpr_integer)
8713 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8714                                semantic_incdec)
8715 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8716                                semantic_incdec)
8717
8718 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8719                                                sfunc)                         \
8720 static expression_t *parse_##unexpression_type(expression_t *left)            \
8721 {                                                                             \
8722         expression_t *unary_expression                                            \
8723                 = allocate_expression_zero(unexpression_type);                        \
8724         eat(token_type);                                                          \
8725         unary_expression->unary.value = left;                                     \
8726                                                                                   \
8727         sfunc(&unary_expression->unary);                                          \
8728                                                                               \
8729         return unary_expression;                                                  \
8730 }
8731
8732 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8733                                        EXPR_UNARY_POSTFIX_INCREMENT,
8734                                        semantic_incdec)
8735 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8736                                        EXPR_UNARY_POSTFIX_DECREMENT,
8737                                        semantic_incdec)
8738
8739 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8740 {
8741         /* TODO: handle complex + imaginary types */
8742
8743         type_left  = get_unqualified_type(type_left);
8744         type_right = get_unqualified_type(type_right);
8745
8746         /* Â§ 6.3.1.8 Usual arithmetic conversions */
8747         if (type_left == type_long_double || type_right == type_long_double) {
8748                 return type_long_double;
8749         } else if (type_left == type_double || type_right == type_double) {
8750                 return type_double;
8751         } else if (type_left == type_float || type_right == type_float) {
8752                 return type_float;
8753         }
8754
8755         type_left  = promote_integer(type_left);
8756         type_right = promote_integer(type_right);
8757
8758         if (type_left == type_right)
8759                 return type_left;
8760
8761         bool const signed_left  = is_type_signed(type_left);
8762         bool const signed_right = is_type_signed(type_right);
8763         int const  rank_left    = get_rank(type_left);
8764         int const  rank_right   = get_rank(type_right);
8765
8766         if (signed_left == signed_right)
8767                 return rank_left >= rank_right ? type_left : type_right;
8768
8769         int     s_rank;
8770         int     u_rank;
8771         type_t *s_type;
8772         type_t *u_type;
8773         if (signed_left) {
8774                 s_rank = rank_left;
8775                 s_type = type_left;
8776                 u_rank = rank_right;
8777                 u_type = type_right;
8778         } else {
8779                 s_rank = rank_right;
8780                 s_type = type_right;
8781                 u_rank = rank_left;
8782                 u_type = type_left;
8783         }
8784
8785         if (u_rank >= s_rank)
8786                 return u_type;
8787
8788         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8789          * easier here... */
8790         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8791                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8792                 return s_type;
8793
8794         switch (s_rank) {
8795                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8796                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8797                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8798
8799                 default: panic("invalid atomic type");
8800         }
8801 }
8802
8803 /**
8804  * Check the semantic restrictions for a binary expression.
8805  */
8806 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8807 {
8808         expression_t *const left            = expression->left;
8809         expression_t *const right           = expression->right;
8810         type_t       *const orig_type_left  = left->base.type;
8811         type_t       *const orig_type_right = right->base.type;
8812         type_t       *const type_left       = skip_typeref(orig_type_left);
8813         type_t       *const type_right      = skip_typeref(orig_type_right);
8814
8815         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8816                 /* TODO: improve error message */
8817                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8818                         errorf(&expression->base.source_position,
8819                                "operation needs arithmetic types");
8820                 }
8821                 return;
8822         }
8823
8824         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8825         expression->left      = create_implicit_cast(left, arithmetic_type);
8826         expression->right     = create_implicit_cast(right, arithmetic_type);
8827         expression->base.type = arithmetic_type;
8828 }
8829
8830 static void warn_div_by_zero(binary_expression_t const *const expression)
8831 {
8832         if (!warning.div_by_zero ||
8833             !is_type_integer(expression->base.type))
8834                 return;
8835
8836         expression_t const *const right = expression->right;
8837         /* The type of the right operand can be different for /= */
8838         if (is_type_integer(right->base.type) &&
8839             is_constant_expression(right)     &&
8840             fold_constant(right) == 0) {
8841                 warningf(&expression->base.source_position, "division by zero");
8842         }
8843 }
8844
8845 /**
8846  * Check the semantic restrictions for a div/mod expression.
8847  */
8848 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8849         semantic_binexpr_arithmetic(expression);
8850         warn_div_by_zero(expression);
8851 }
8852
8853 static void warn_addsub_in_shift(const expression_t *const expr)
8854 {
8855         char op;
8856         switch (expr->kind) {
8857                 case EXPR_BINARY_ADD: op = '+'; break;
8858                 case EXPR_BINARY_SUB: op = '-'; break;
8859                 default:              return;
8860         }
8861
8862         warningf(&expr->base.source_position,
8863                         "suggest parentheses around '%c' inside shift", op);
8864 }
8865
8866 static void semantic_shift_op(binary_expression_t *expression)
8867 {
8868         expression_t *const left            = expression->left;
8869         expression_t *const right           = expression->right;
8870         type_t       *const orig_type_left  = left->base.type;
8871         type_t       *const orig_type_right = right->base.type;
8872         type_t       *      type_left       = skip_typeref(orig_type_left);
8873         type_t       *      type_right      = skip_typeref(orig_type_right);
8874
8875         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8876                 /* TODO: improve error message */
8877                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8878                         errorf(&expression->base.source_position,
8879                                "operands of shift operation must have integer types");
8880                 }
8881                 return;
8882         }
8883
8884         if (warning.parentheses) {
8885                 warn_addsub_in_shift(left);
8886                 warn_addsub_in_shift(right);
8887         }
8888
8889         type_left  = promote_integer(type_left);
8890         type_right = promote_integer(type_right);
8891
8892         expression->left      = create_implicit_cast(left, type_left);
8893         expression->right     = create_implicit_cast(right, type_right);
8894         expression->base.type = type_left;
8895 }
8896
8897 static void semantic_add(binary_expression_t *expression)
8898 {
8899         expression_t *const left            = expression->left;
8900         expression_t *const right           = expression->right;
8901         type_t       *const orig_type_left  = left->base.type;
8902         type_t       *const orig_type_right = right->base.type;
8903         type_t       *const type_left       = skip_typeref(orig_type_left);
8904         type_t       *const type_right      = skip_typeref(orig_type_right);
8905
8906         /* Â§ 6.5.6 */
8907         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8908                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8909                 expression->left  = create_implicit_cast(left, arithmetic_type);
8910                 expression->right = create_implicit_cast(right, arithmetic_type);
8911                 expression->base.type = arithmetic_type;
8912         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8913                 check_pointer_arithmetic(&expression->base.source_position,
8914                                          type_left, orig_type_left);
8915                 expression->base.type = type_left;
8916         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8917                 check_pointer_arithmetic(&expression->base.source_position,
8918                                          type_right, orig_type_right);
8919                 expression->base.type = type_right;
8920         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8921                 errorf(&expression->base.source_position,
8922                        "invalid operands to binary + ('%T', '%T')",
8923                        orig_type_left, orig_type_right);
8924         }
8925 }
8926
8927 static void semantic_sub(binary_expression_t *expression)
8928 {
8929         expression_t            *const left            = expression->left;
8930         expression_t            *const right           = expression->right;
8931         type_t                  *const orig_type_left  = left->base.type;
8932         type_t                  *const orig_type_right = right->base.type;
8933         type_t                  *const type_left       = skip_typeref(orig_type_left);
8934         type_t                  *const type_right      = skip_typeref(orig_type_right);
8935         source_position_t const *const pos             = &expression->base.source_position;
8936
8937         /* Â§ 5.6.5 */
8938         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8939                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8940                 expression->left        = create_implicit_cast(left, arithmetic_type);
8941                 expression->right       = create_implicit_cast(right, arithmetic_type);
8942                 expression->base.type =  arithmetic_type;
8943         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8944                 check_pointer_arithmetic(&expression->base.source_position,
8945                                          type_left, orig_type_left);
8946                 expression->base.type = type_left;
8947         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8948                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8949                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8950                 if (!types_compatible(unqual_left, unqual_right)) {
8951                         errorf(pos,
8952                                "subtracting pointers to incompatible types '%T' and '%T'",
8953                                orig_type_left, orig_type_right);
8954                 } else if (!is_type_object(unqual_left)) {
8955                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8956                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8957                                        orig_type_left);
8958                         } else if (warning.other) {
8959                                 warningf(pos, "subtracting pointers to void");
8960                         }
8961                 }
8962                 expression->base.type = type_ptrdiff_t;
8963         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8964                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8965                        orig_type_left, orig_type_right);
8966         }
8967 }
8968
8969 static void warn_string_literal_address(expression_t const* expr)
8970 {
8971         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8972                 expr = expr->unary.value;
8973                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8974                         return;
8975                 expr = expr->unary.value;
8976         }
8977
8978         if (expr->kind == EXPR_STRING_LITERAL ||
8979             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8980                 warningf(&expr->base.source_position,
8981                         "comparison with string literal results in unspecified behaviour");
8982         }
8983 }
8984
8985 static void warn_comparison_in_comparison(const expression_t *const expr)
8986 {
8987         if (expr->base.parenthesized)
8988                 return;
8989         switch (expr->base.kind) {
8990                 case EXPR_BINARY_LESS:
8991                 case EXPR_BINARY_GREATER:
8992                 case EXPR_BINARY_LESSEQUAL:
8993                 case EXPR_BINARY_GREATEREQUAL:
8994                 case EXPR_BINARY_NOTEQUAL:
8995                 case EXPR_BINARY_EQUAL:
8996                         warningf(&expr->base.source_position,
8997                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8998                         break;
8999                 default:
9000                         break;
9001         }
9002 }
9003
9004 /**
9005  * Check the semantics of comparison expressions.
9006  *
9007  * @param expression   The expression to check.
9008  */
9009 static void semantic_comparison(binary_expression_t *expression)
9010 {
9011         expression_t *left  = expression->left;
9012         expression_t *right = expression->right;
9013
9014         if (warning.address) {
9015                 warn_string_literal_address(left);
9016                 warn_string_literal_address(right);
9017
9018                 expression_t const* const func_left = get_reference_address(left);
9019                 if (func_left != NULL && is_null_pointer_constant(right)) {
9020                         warningf(&expression->base.source_position,
9021                                  "the address of '%Y' will never be NULL",
9022                                  func_left->reference.entity->base.symbol);
9023                 }
9024
9025                 expression_t const* const func_right = get_reference_address(right);
9026                 if (func_right != NULL && is_null_pointer_constant(right)) {
9027                         warningf(&expression->base.source_position,
9028                                  "the address of '%Y' will never be NULL",
9029                                  func_right->reference.entity->base.symbol);
9030                 }
9031         }
9032
9033         if (warning.parentheses) {
9034                 warn_comparison_in_comparison(left);
9035                 warn_comparison_in_comparison(right);
9036         }
9037
9038         type_t *orig_type_left  = left->base.type;
9039         type_t *orig_type_right = right->base.type;
9040         type_t *type_left       = skip_typeref(orig_type_left);
9041         type_t *type_right      = skip_typeref(orig_type_right);
9042
9043         /* TODO non-arithmetic types */
9044         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9045                 /* test for signed vs unsigned compares */
9046                 if (warning.sign_compare &&
9047                     (expression->base.kind != EXPR_BINARY_EQUAL &&
9048                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
9049                     (is_type_signed(type_left) != is_type_signed(type_right))) {
9050
9051                         /* check if 1 of the operands is a constant, in this case we just
9052                          * check wether we can safely represent the resulting constant in
9053                          * the type of the other operand. */
9054                         expression_t *const_expr = NULL;
9055                         expression_t *other_expr = NULL;
9056
9057                         if (is_constant_expression(left)) {
9058                                 const_expr = left;
9059                                 other_expr = right;
9060                         } else if (is_constant_expression(right)) {
9061                                 const_expr = right;
9062                                 other_expr = left;
9063                         }
9064
9065                         if (const_expr != NULL) {
9066                                 type_t *other_type = skip_typeref(other_expr->base.type);
9067                                 long    val        = fold_constant(const_expr);
9068                                 /* TODO: check if val can be represented by other_type */
9069                                 (void) other_type;
9070                                 (void) val;
9071                         }
9072                         warningf(&expression->base.source_position,
9073                                  "comparison between signed and unsigned");
9074                 }
9075                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9076                 expression->left        = create_implicit_cast(left, arithmetic_type);
9077                 expression->right       = create_implicit_cast(right, arithmetic_type);
9078                 expression->base.type   = arithmetic_type;
9079                 if (warning.float_equal &&
9080                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9081                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9082                     is_type_float(arithmetic_type)) {
9083                         warningf(&expression->base.source_position,
9084                                  "comparing floating point with == or != is unsafe");
9085                 }
9086         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9087                 /* TODO check compatibility */
9088         } else if (is_type_pointer(type_left)) {
9089                 expression->right = create_implicit_cast(right, type_left);
9090         } else if (is_type_pointer(type_right)) {
9091                 expression->left = create_implicit_cast(left, type_right);
9092         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9093                 type_error_incompatible("invalid operands in comparison",
9094                                         &expression->base.source_position,
9095                                         type_left, type_right);
9096         }
9097         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9098 }
9099
9100 /**
9101  * Checks if a compound type has constant fields.
9102  */
9103 static bool has_const_fields(const compound_type_t *type)
9104 {
9105         compound_t *compound = type->compound;
9106         entity_t   *entry    = compound->members.entities;
9107
9108         for (; entry != NULL; entry = entry->base.next) {
9109                 if (!is_declaration(entry))
9110                         continue;
9111
9112                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9113                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9114                         return true;
9115         }
9116
9117         return false;
9118 }
9119
9120 static bool is_valid_assignment_lhs(expression_t const* const left)
9121 {
9122         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9123         type_t *const type_left      = skip_typeref(orig_type_left);
9124
9125         if (!is_lvalue(left)) {
9126                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9127                        left);
9128                 return false;
9129         }
9130
9131         if (left->kind == EXPR_REFERENCE
9132                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9133                 errorf(HERE, "cannot assign to function '%E'", left);
9134                 return false;
9135         }
9136
9137         if (is_type_array(type_left)) {
9138                 errorf(HERE, "cannot assign to array '%E'", left);
9139                 return false;
9140         }
9141         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9142                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9143                        orig_type_left);
9144                 return false;
9145         }
9146         if (is_type_incomplete(type_left)) {
9147                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9148                        left, orig_type_left);
9149                 return false;
9150         }
9151         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9152                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9153                        left, orig_type_left);
9154                 return false;
9155         }
9156
9157         return true;
9158 }
9159
9160 static void semantic_arithmetic_assign(binary_expression_t *expression)
9161 {
9162         expression_t *left            = expression->left;
9163         expression_t *right           = expression->right;
9164         type_t       *orig_type_left  = left->base.type;
9165         type_t       *orig_type_right = right->base.type;
9166
9167         if (!is_valid_assignment_lhs(left))
9168                 return;
9169
9170         type_t *type_left  = skip_typeref(orig_type_left);
9171         type_t *type_right = skip_typeref(orig_type_right);
9172
9173         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9174                 /* TODO: improve error message */
9175                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9176                         errorf(&expression->base.source_position,
9177                                "operation needs arithmetic types");
9178                 }
9179                 return;
9180         }
9181
9182         /* combined instructions are tricky. We can't create an implicit cast on
9183          * the left side, because we need the uncasted form for the store.
9184          * The ast2firm pass has to know that left_type must be right_type
9185          * for the arithmetic operation and create a cast by itself */
9186         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9187         expression->right       = create_implicit_cast(right, arithmetic_type);
9188         expression->base.type   = type_left;
9189 }
9190
9191 static void semantic_divmod_assign(binary_expression_t *expression)
9192 {
9193         semantic_arithmetic_assign(expression);
9194         warn_div_by_zero(expression);
9195 }
9196
9197 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9198 {
9199         expression_t *const left            = expression->left;
9200         expression_t *const right           = expression->right;
9201         type_t       *const orig_type_left  = left->base.type;
9202         type_t       *const orig_type_right = right->base.type;
9203         type_t       *const type_left       = skip_typeref(orig_type_left);
9204         type_t       *const type_right      = skip_typeref(orig_type_right);
9205
9206         if (!is_valid_assignment_lhs(left))
9207                 return;
9208
9209         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9210                 /* combined instructions are tricky. We can't create an implicit cast on
9211                  * the left side, because we need the uncasted form for the store.
9212                  * The ast2firm pass has to know that left_type must be right_type
9213                  * for the arithmetic operation and create a cast by itself */
9214                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9215                 expression->right     = create_implicit_cast(right, arithmetic_type);
9216                 expression->base.type = type_left;
9217         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9218                 check_pointer_arithmetic(&expression->base.source_position,
9219                                          type_left, orig_type_left);
9220                 expression->base.type = type_left;
9221         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9222                 errorf(&expression->base.source_position,
9223                        "incompatible types '%T' and '%T' in assignment",
9224                        orig_type_left, orig_type_right);
9225         }
9226 }
9227
9228 static void warn_logical_and_within_or(const expression_t *const expr)
9229 {
9230         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9231                 return;
9232         if (expr->base.parenthesized)
9233                 return;
9234         warningf(&expr->base.source_position,
9235                         "suggest parentheses around && within ||");
9236 }
9237
9238 /**
9239  * Check the semantic restrictions of a logical expression.
9240  */
9241 static void semantic_logical_op(binary_expression_t *expression)
9242 {
9243         /* Â§6.5.13:2  Each of the operands shall have scalar type.
9244          * Â§6.5.14:2  Each of the operands shall have scalar type. */
9245         semantic_condition(expression->left,   "left operand of logical operator");
9246         semantic_condition(expression->right, "right operand of logical operator");
9247         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9248                         warning.parentheses) {
9249                 warn_logical_and_within_or(expression->left);
9250                 warn_logical_and_within_or(expression->right);
9251         }
9252         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9253 }
9254
9255 /**
9256  * Check the semantic restrictions of a binary assign expression.
9257  */
9258 static void semantic_binexpr_assign(binary_expression_t *expression)
9259 {
9260         expression_t *left           = expression->left;
9261         type_t       *orig_type_left = left->base.type;
9262
9263         if (!is_valid_assignment_lhs(left))
9264                 return;
9265
9266         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9267         report_assign_error(error, orig_type_left, expression->right,
9268                         "assignment", &left->base.source_position);
9269         expression->right = create_implicit_cast(expression->right, orig_type_left);
9270         expression->base.type = orig_type_left;
9271 }
9272
9273 /**
9274  * Determine if the outermost operation (or parts thereof) of the given
9275  * expression has no effect in order to generate a warning about this fact.
9276  * Therefore in some cases this only examines some of the operands of the
9277  * expression (see comments in the function and examples below).
9278  * Examples:
9279  *   f() + 23;    // warning, because + has no effect
9280  *   x || f();    // no warning, because x controls execution of f()
9281  *   x ? y : f(); // warning, because y has no effect
9282  *   (void)x;     // no warning to be able to suppress the warning
9283  * This function can NOT be used for an "expression has definitely no effect"-
9284  * analysis. */
9285 static bool expression_has_effect(const expression_t *const expr)
9286 {
9287         switch (expr->kind) {
9288                 case EXPR_UNKNOWN:                   break;
9289                 case EXPR_INVALID:                   return true; /* do NOT warn */
9290                 case EXPR_REFERENCE:                 return false;
9291                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
9292                 /* suppress the warning for microsoft __noop operations */
9293                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
9294                 case EXPR_CHARACTER_CONSTANT:        return false;
9295                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
9296                 case EXPR_STRING_LITERAL:            return false;
9297                 case EXPR_WIDE_STRING_LITERAL:       return false;
9298                 case EXPR_LABEL_ADDRESS:             return false;
9299
9300                 case EXPR_CALL: {
9301                         const call_expression_t *const call = &expr->call;
9302                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9303                                 return true;
9304
9305                         switch (call->function->builtin_symbol.symbol->ID) {
9306                                 case T___builtin_va_end: return true;
9307                                 default:                 return false;
9308                         }
9309                 }
9310
9311                 /* Generate the warning if either the left or right hand side of a
9312                  * conditional expression has no effect */
9313                 case EXPR_CONDITIONAL: {
9314                         const conditional_expression_t *const cond = &expr->conditional;
9315                         return
9316                                 expression_has_effect(cond->true_expression) &&
9317                                 expression_has_effect(cond->false_expression);
9318                 }
9319
9320                 case EXPR_SELECT:                    return false;
9321                 case EXPR_ARRAY_ACCESS:              return false;
9322                 case EXPR_SIZEOF:                    return false;
9323                 case EXPR_CLASSIFY_TYPE:             return false;
9324                 case EXPR_ALIGNOF:                   return false;
9325
9326                 case EXPR_FUNCNAME:                  return false;
9327                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
9328                 case EXPR_BUILTIN_CONSTANT_P:        return false;
9329                 case EXPR_BUILTIN_PREFETCH:          return true;
9330                 case EXPR_OFFSETOF:                  return false;
9331                 case EXPR_VA_START:                  return true;
9332                 case EXPR_VA_ARG:                    return true;
9333                 case EXPR_STATEMENT:                 return true; // TODO
9334                 case EXPR_COMPOUND_LITERAL:          return false;
9335
9336                 case EXPR_UNARY_NEGATE:              return false;
9337                 case EXPR_UNARY_PLUS:                return false;
9338                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
9339                 case EXPR_UNARY_NOT:                 return false;
9340                 case EXPR_UNARY_DEREFERENCE:         return false;
9341                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
9342                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
9343                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
9344                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
9345                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
9346
9347                 /* Treat void casts as if they have an effect in order to being able to
9348                  * suppress the warning */
9349                 case EXPR_UNARY_CAST: {
9350                         type_t *const type = skip_typeref(expr->base.type);
9351                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9352                 }
9353
9354                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
9355                 case EXPR_UNARY_ASSUME:              return true;
9356                 case EXPR_UNARY_DELETE:              return true;
9357                 case EXPR_UNARY_DELETE_ARRAY:        return true;
9358                 case EXPR_UNARY_THROW:               return true;
9359
9360                 case EXPR_BINARY_ADD:                return false;
9361                 case EXPR_BINARY_SUB:                return false;
9362                 case EXPR_BINARY_MUL:                return false;
9363                 case EXPR_BINARY_DIV:                return false;
9364                 case EXPR_BINARY_MOD:                return false;
9365                 case EXPR_BINARY_EQUAL:              return false;
9366                 case EXPR_BINARY_NOTEQUAL:           return false;
9367                 case EXPR_BINARY_LESS:               return false;
9368                 case EXPR_BINARY_LESSEQUAL:          return false;
9369                 case EXPR_BINARY_GREATER:            return false;
9370                 case EXPR_BINARY_GREATEREQUAL:       return false;
9371                 case EXPR_BINARY_BITWISE_AND:        return false;
9372                 case EXPR_BINARY_BITWISE_OR:         return false;
9373                 case EXPR_BINARY_BITWISE_XOR:        return false;
9374                 case EXPR_BINARY_SHIFTLEFT:          return false;
9375                 case EXPR_BINARY_SHIFTRIGHT:         return false;
9376                 case EXPR_BINARY_ASSIGN:             return true;
9377                 case EXPR_BINARY_MUL_ASSIGN:         return true;
9378                 case EXPR_BINARY_DIV_ASSIGN:         return true;
9379                 case EXPR_BINARY_MOD_ASSIGN:         return true;
9380                 case EXPR_BINARY_ADD_ASSIGN:         return true;
9381                 case EXPR_BINARY_SUB_ASSIGN:         return true;
9382                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
9383                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
9384                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
9385                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
9386                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
9387
9388                 /* Only examine the right hand side of && and ||, because the left hand
9389                  * side already has the effect of controlling the execution of the right
9390                  * hand side */
9391                 case EXPR_BINARY_LOGICAL_AND:
9392                 case EXPR_BINARY_LOGICAL_OR:
9393                 /* Only examine the right hand side of a comma expression, because the left
9394                  * hand side has a separate warning */
9395                 case EXPR_BINARY_COMMA:
9396                         return expression_has_effect(expr->binary.right);
9397
9398                 case EXPR_BINARY_ISGREATER:          return false;
9399                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9400                 case EXPR_BINARY_ISLESS:             return false;
9401                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9402                 case EXPR_BINARY_ISLESSGREATER:      return false;
9403                 case EXPR_BINARY_ISUNORDERED:        return false;
9404         }
9405
9406         internal_errorf(HERE, "unexpected expression");
9407 }
9408
9409 static void semantic_comma(binary_expression_t *expression)
9410 {
9411         if (warning.unused_value) {
9412                 const expression_t *const left = expression->left;
9413                 if (!expression_has_effect(left)) {
9414                         warningf(&left->base.source_position,
9415                                  "left-hand operand of comma expression has no effect");
9416                 }
9417         }
9418         expression->base.type = expression->right->base.type;
9419 }
9420
9421 /**
9422  * @param prec_r precedence of the right operand
9423  */
9424 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9425 static expression_t *parse_##binexpression_type(expression_t *left)          \
9426 {                                                                            \
9427         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9428         binexpr->binary.left  = left;                                            \
9429         eat(token_type);                                                         \
9430                                                                              \
9431         expression_t *right = parse_sub_expression(prec_r);                      \
9432                                                                              \
9433         binexpr->binary.right = right;                                           \
9434         sfunc(&binexpr->binary);                                                 \
9435                                                                              \
9436         return binexpr;                                                          \
9437 }
9438
9439 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9440 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9441 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9442 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9443 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9444 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9445 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9446 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9447 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9448 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9449 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9450 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9451 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9452 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9453 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9454 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9455 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9456 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9457 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9458 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9459 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9460 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9461 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9462 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9463 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9464 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9465 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9466 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9467 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9468 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9469
9470
9471 static expression_t *parse_sub_expression(precedence_t precedence)
9472 {
9473         if (token.type < 0) {
9474                 return expected_expression_error();
9475         }
9476
9477         expression_parser_function_t *parser
9478                 = &expression_parsers[token.type];
9479         source_position_t             source_position = token.source_position;
9480         expression_t                 *left;
9481
9482         if (parser->parser != NULL) {
9483                 left = parser->parser();
9484         } else {
9485                 left = parse_primary_expression();
9486         }
9487         assert(left != NULL);
9488         left->base.source_position = source_position;
9489
9490         while (true) {
9491                 if (token.type < 0) {
9492                         return expected_expression_error();
9493                 }
9494
9495                 parser = &expression_parsers[token.type];
9496                 if (parser->infix_parser == NULL)
9497                         break;
9498                 if (parser->infix_precedence < precedence)
9499                         break;
9500
9501                 left = parser->infix_parser(left);
9502
9503                 assert(left != NULL);
9504                 assert(left->kind != EXPR_UNKNOWN);
9505                 left->base.source_position = source_position;
9506         }
9507
9508         return left;
9509 }
9510
9511 /**
9512  * Parse an expression.
9513  */
9514 static expression_t *parse_expression(void)
9515 {
9516         return parse_sub_expression(PREC_EXPRESSION);
9517 }
9518
9519 /**
9520  * Register a parser for a prefix-like operator.
9521  *
9522  * @param parser      the parser function
9523  * @param token_type  the token type of the prefix token
9524  */
9525 static void register_expression_parser(parse_expression_function parser,
9526                                        int token_type)
9527 {
9528         expression_parser_function_t *entry = &expression_parsers[token_type];
9529
9530         if (entry->parser != NULL) {
9531                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9532                 panic("trying to register multiple expression parsers for a token");
9533         }
9534         entry->parser = parser;
9535 }
9536
9537 /**
9538  * Register a parser for an infix operator with given precedence.
9539  *
9540  * @param parser      the parser function
9541  * @param token_type  the token type of the infix operator
9542  * @param precedence  the precedence of the operator
9543  */
9544 static void register_infix_parser(parse_expression_infix_function parser,
9545                 int token_type, unsigned precedence)
9546 {
9547         expression_parser_function_t *entry = &expression_parsers[token_type];
9548
9549         if (entry->infix_parser != NULL) {
9550                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9551                 panic("trying to register multiple infix expression parsers for a "
9552                       "token");
9553         }
9554         entry->infix_parser     = parser;
9555         entry->infix_precedence = precedence;
9556 }
9557
9558 /**
9559  * Initialize the expression parsers.
9560  */
9561 static void init_expression_parsers(void)
9562 {
9563         memset(&expression_parsers, 0, sizeof(expression_parsers));
9564
9565         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9566         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9567         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9568         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9569         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9570         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9571         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9572         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9573         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9574         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9575         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9576         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9577         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9578         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9579         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9580         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9581         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9582         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9583         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9584         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9585         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9586         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9587         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9588         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9589         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9590         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9591         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9592         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9593         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9594         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9595         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9596         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9597         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9598         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9599         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9600         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9601         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9602
9603         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9604         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9605         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9606         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9607         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9608         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9609         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9610         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9611         register_expression_parser(parse_sizeof,                      T_sizeof);
9612         register_expression_parser(parse_alignof,                     T___alignof__);
9613         register_expression_parser(parse_extension,                   T___extension__);
9614         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9615         register_expression_parser(parse_delete,                      T_delete);
9616         register_expression_parser(parse_throw,                       T_throw);
9617 }
9618
9619 /**
9620  * Parse a asm statement arguments specification.
9621  */
9622 static asm_argument_t *parse_asm_arguments(bool is_out)
9623 {
9624         asm_argument_t  *result = NULL;
9625         asm_argument_t **anchor = &result;
9626
9627         while (token.type == T_STRING_LITERAL || token.type == '[') {
9628                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9629                 memset(argument, 0, sizeof(argument[0]));
9630
9631                 if (token.type == '[') {
9632                         eat('[');
9633                         if (token.type != T_IDENTIFIER) {
9634                                 parse_error_expected("while parsing asm argument",
9635                                                      T_IDENTIFIER, NULL);
9636                                 return NULL;
9637                         }
9638                         argument->symbol = token.v.symbol;
9639
9640                         expect(']', end_error);
9641                 }
9642
9643                 argument->constraints = parse_string_literals();
9644                 expect('(', end_error);
9645                 add_anchor_token(')');
9646                 expression_t *expression = parse_expression();
9647                 rem_anchor_token(')');
9648                 if (is_out) {
9649                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9650                          * change size or type representation (e.g. int -> long is ok, but
9651                          * int -> float is not) */
9652                         if (expression->kind == EXPR_UNARY_CAST) {
9653                                 type_t      *const type = expression->base.type;
9654                                 type_kind_t  const kind = type->kind;
9655                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9656                                         unsigned flags;
9657                                         unsigned size;
9658                                         if (kind == TYPE_ATOMIC) {
9659                                                 atomic_type_kind_t const akind = type->atomic.akind;
9660                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9661                                                 size  = get_atomic_type_size(akind);
9662                                         } else {
9663                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9664                                                 size  = get_atomic_type_size(get_intptr_kind());
9665                                         }
9666
9667                                         do {
9668                                                 expression_t *const value      = expression->unary.value;
9669                                                 type_t       *const value_type = value->base.type;
9670                                                 type_kind_t   const value_kind = value_type->kind;
9671
9672                                                 unsigned value_flags;
9673                                                 unsigned value_size;
9674                                                 if (value_kind == TYPE_ATOMIC) {
9675                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9676                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9677                                                         value_size  = get_atomic_type_size(value_akind);
9678                                                 } else if (value_kind == TYPE_POINTER) {
9679                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9680                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9681                                                 } else {
9682                                                         break;
9683                                                 }
9684
9685                                                 if (value_flags != flags || value_size != size)
9686                                                         break;
9687
9688                                                 expression = value;
9689                                         } while (expression->kind == EXPR_UNARY_CAST);
9690                                 }
9691                         }
9692
9693                         if (!is_lvalue(expression)) {
9694                                 errorf(&expression->base.source_position,
9695                                        "asm output argument is not an lvalue");
9696                         }
9697
9698                         if (argument->constraints.begin[0] == '+')
9699                                 mark_vars_read(expression, NULL);
9700                 } else {
9701                         mark_vars_read(expression, NULL);
9702                 }
9703                 argument->expression = expression;
9704                 expect(')', end_error);
9705
9706                 set_address_taken(expression, true);
9707
9708                 *anchor = argument;
9709                 anchor  = &argument->next;
9710
9711                 if (token.type != ',')
9712                         break;
9713                 eat(',');
9714         }
9715
9716         return result;
9717 end_error:
9718         return NULL;
9719 }
9720
9721 /**
9722  * Parse a asm statement clobber specification.
9723  */
9724 static asm_clobber_t *parse_asm_clobbers(void)
9725 {
9726         asm_clobber_t *result = NULL;
9727         asm_clobber_t *last   = NULL;
9728
9729         while (token.type == T_STRING_LITERAL) {
9730                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9731                 clobber->clobber       = parse_string_literals();
9732
9733                 if (last != NULL) {
9734                         last->next = clobber;
9735                 } else {
9736                         result = clobber;
9737                 }
9738                 last = clobber;
9739
9740                 if (token.type != ',')
9741                         break;
9742                 eat(',');
9743         }
9744
9745         return result;
9746 }
9747
9748 /**
9749  * Parse an asm statement.
9750  */
9751 static statement_t *parse_asm_statement(void)
9752 {
9753         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9754         asm_statement_t *asm_statement = &statement->asms;
9755
9756         eat(T_asm);
9757
9758         if (token.type == T_volatile) {
9759                 next_token();
9760                 asm_statement->is_volatile = true;
9761         }
9762
9763         expect('(', end_error);
9764         add_anchor_token(')');
9765         add_anchor_token(':');
9766         asm_statement->asm_text = parse_string_literals();
9767
9768         if (token.type != ':') {
9769                 rem_anchor_token(':');
9770                 goto end_of_asm;
9771         }
9772         eat(':');
9773
9774         asm_statement->outputs = parse_asm_arguments(true);
9775         if (token.type != ':') {
9776                 rem_anchor_token(':');
9777                 goto end_of_asm;
9778         }
9779         eat(':');
9780
9781         asm_statement->inputs = parse_asm_arguments(false);
9782         if (token.type != ':') {
9783                 rem_anchor_token(':');
9784                 goto end_of_asm;
9785         }
9786         rem_anchor_token(':');
9787         eat(':');
9788
9789         asm_statement->clobbers = parse_asm_clobbers();
9790
9791 end_of_asm:
9792         rem_anchor_token(')');
9793         expect(')', end_error);
9794         expect(';', end_error);
9795
9796         if (asm_statement->outputs == NULL) {
9797                 /* GCC: An 'asm' instruction without any output operands will be treated
9798                  * identically to a volatile 'asm' instruction. */
9799                 asm_statement->is_volatile = true;
9800         }
9801
9802         return statement;
9803 end_error:
9804         return create_invalid_statement();
9805 }
9806
9807 /**
9808  * Parse a case statement.
9809  */
9810 static statement_t *parse_case_statement(void)
9811 {
9812         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9813         source_position_t *const pos       = &statement->base.source_position;
9814
9815         eat(T_case);
9816
9817         expression_t *const expression   = parse_expression();
9818         statement->case_label.expression = expression;
9819         if (!is_constant_expression(expression)) {
9820                 /* This check does not prevent the error message in all cases of an
9821                  * prior error while parsing the expression.  At least it catches the
9822                  * common case of a mistyped enum entry. */
9823                 if (is_type_valid(skip_typeref(expression->base.type))) {
9824                         errorf(pos, "case label does not reduce to an integer constant");
9825                 }
9826                 statement->case_label.is_bad = true;
9827         } else {
9828                 long const val = fold_constant(expression);
9829                 statement->case_label.first_case = val;
9830                 statement->case_label.last_case  = val;
9831         }
9832
9833         if (GNU_MODE) {
9834                 if (token.type == T_DOTDOTDOT) {
9835                         next_token();
9836                         expression_t *const end_range   = parse_expression();
9837                         statement->case_label.end_range = end_range;
9838                         if (!is_constant_expression(end_range)) {
9839                                 /* This check does not prevent the error message in all cases of an
9840                                  * prior error while parsing the expression.  At least it catches the
9841                                  * common case of a mistyped enum entry. */
9842                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9843                                         errorf(pos, "case range does not reduce to an integer constant");
9844                                 }
9845                                 statement->case_label.is_bad = true;
9846                         } else {
9847                                 long const val = fold_constant(end_range);
9848                                 statement->case_label.last_case = val;
9849
9850                                 if (warning.other && val < statement->case_label.first_case) {
9851                                         statement->case_label.is_empty_range = true;
9852                                         warningf(pos, "empty range specified");
9853                                 }
9854                         }
9855                 }
9856         }
9857
9858         PUSH_PARENT(statement);
9859
9860         expect(':', end_error);
9861 end_error:
9862
9863         if (current_switch != NULL) {
9864                 if (! statement->case_label.is_bad) {
9865                         /* Check for duplicate case values */
9866                         case_label_statement_t *c = &statement->case_label;
9867                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9868                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9869                                         continue;
9870
9871                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9872                                         continue;
9873
9874                                 errorf(pos, "duplicate case value (previously used %P)",
9875                                        &l->base.source_position);
9876                                 break;
9877                         }
9878                 }
9879                 /* link all cases into the switch statement */
9880                 if (current_switch->last_case == NULL) {
9881                         current_switch->first_case      = &statement->case_label;
9882                 } else {
9883                         current_switch->last_case->next = &statement->case_label;
9884                 }
9885                 current_switch->last_case = &statement->case_label;
9886         } else {
9887                 errorf(pos, "case label not within a switch statement");
9888         }
9889
9890         statement_t *const inner_stmt = parse_statement();
9891         statement->case_label.statement = inner_stmt;
9892         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9893                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9894         }
9895
9896         POP_PARENT;
9897         return statement;
9898 }
9899
9900 /**
9901  * Parse a default statement.
9902  */
9903 static statement_t *parse_default_statement(void)
9904 {
9905         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9906
9907         eat(T_default);
9908
9909         PUSH_PARENT(statement);
9910
9911         expect(':', end_error);
9912         if (current_switch != NULL) {
9913                 const case_label_statement_t *def_label = current_switch->default_label;
9914                 if (def_label != NULL) {
9915                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9916                                &def_label->base.source_position);
9917                 } else {
9918                         current_switch->default_label = &statement->case_label;
9919
9920                         /* link all cases into the switch statement */
9921                         if (current_switch->last_case == NULL) {
9922                                 current_switch->first_case      = &statement->case_label;
9923                         } else {
9924                                 current_switch->last_case->next = &statement->case_label;
9925                         }
9926                         current_switch->last_case = &statement->case_label;
9927                 }
9928         } else {
9929                 errorf(&statement->base.source_position,
9930                         "'default' label not within a switch statement");
9931         }
9932
9933         statement_t *const inner_stmt = parse_statement();
9934         statement->case_label.statement = inner_stmt;
9935         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9936                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9937         }
9938
9939         POP_PARENT;
9940         return statement;
9941 end_error:
9942         POP_PARENT;
9943         return create_invalid_statement();
9944 }
9945
9946 /**
9947  * Parse a label statement.
9948  */
9949 static statement_t *parse_label_statement(void)
9950 {
9951         assert(token.type == T_IDENTIFIER);
9952         symbol_t *symbol = token.v.symbol;
9953         label_t  *label  = get_label(symbol);
9954
9955         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9956         statement->label.label       = label;
9957
9958         next_token();
9959
9960         PUSH_PARENT(statement);
9961
9962         /* if statement is already set then the label is defined twice,
9963          * otherwise it was just mentioned in a goto/local label declaration so far
9964          */
9965         if (label->statement != NULL) {
9966                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9967                        symbol, &label->base.source_position);
9968         } else {
9969                 label->base.source_position = token.source_position;
9970                 label->statement            = statement;
9971         }
9972
9973         eat(':');
9974
9975         if (token.type == '}') {
9976                 /* TODO only warn? */
9977                 if (warning.other && false) {
9978                         warningf(HERE, "label at end of compound statement");
9979                         statement->label.statement = create_empty_statement();
9980                 } else {
9981                         errorf(HERE, "label at end of compound statement");
9982                         statement->label.statement = create_invalid_statement();
9983                 }
9984         } else if (token.type == ';') {
9985                 /* Eat an empty statement here, to avoid the warning about an empty
9986                  * statement after a label.  label:; is commonly used to have a label
9987                  * before a closing brace. */
9988                 statement->label.statement = create_empty_statement();
9989                 next_token();
9990         } else {
9991                 statement_t *const inner_stmt = parse_statement();
9992                 statement->label.statement = inner_stmt;
9993                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9994                         errorf(&inner_stmt->base.source_position, "declaration after label");
9995                 }
9996         }
9997
9998         /* remember the labels in a list for later checking */
9999         *label_anchor = &statement->label;
10000         label_anchor  = &statement->label.next;
10001
10002         POP_PARENT;
10003         return statement;
10004 }
10005
10006 /**
10007  * Parse an if statement.
10008  */
10009 static statement_t *parse_if(void)
10010 {
10011         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10012
10013         eat(T_if);
10014
10015         PUSH_PARENT(statement);
10016
10017         add_anchor_token('{');
10018
10019         expect('(', end_error);
10020         add_anchor_token(')');
10021         expression_t *const expr = parse_expression();
10022         statement->ifs.condition = expr;
10023         /* Â§6.8.4.1:1  The controlling expression of an if statement shall have
10024          *             scalar type. */
10025         semantic_condition(expr, "condition of 'if'-statment");
10026         mark_vars_read(expr, NULL);
10027         rem_anchor_token(')');
10028         expect(')', end_error);
10029
10030 end_error:
10031         rem_anchor_token('{');
10032
10033         add_anchor_token(T_else);
10034         statement_t *const true_stmt = parse_statement();
10035         statement->ifs.true_statement = true_stmt;
10036         rem_anchor_token(T_else);
10037
10038         if (token.type == T_else) {
10039                 next_token();
10040                 statement->ifs.false_statement = parse_statement();
10041         } else if (warning.parentheses &&
10042                         true_stmt->kind == STATEMENT_IF &&
10043                         true_stmt->ifs.false_statement != NULL) {
10044                 warningf(&true_stmt->base.source_position,
10045                                 "suggest explicit braces to avoid ambiguous 'else'");
10046         }
10047
10048         POP_PARENT;
10049         return statement;
10050 }
10051
10052 /**
10053  * Check that all enums are handled in a switch.
10054  *
10055  * @param statement  the switch statement to check
10056  */
10057 static void check_enum_cases(const switch_statement_t *statement) {
10058         const type_t *type = skip_typeref(statement->expression->base.type);
10059         if (! is_type_enum(type))
10060                 return;
10061         const enum_type_t *enumt = &type->enumt;
10062
10063         /* if we have a default, no warnings */
10064         if (statement->default_label != NULL)
10065                 return;
10066
10067         /* FIXME: calculation of value should be done while parsing */
10068         /* TODO: quadratic algorithm here. Change to an n log n one */
10069         long            last_value = -1;
10070         const entity_t *entry      = enumt->enume->base.next;
10071         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10072              entry = entry->base.next) {
10073                 const expression_t *expression = entry->enum_value.value;
10074                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10075                 bool                found      = false;
10076                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10077                         if (l->expression == NULL)
10078                                 continue;
10079                         if (l->first_case <= value && value <= l->last_case) {
10080                                 found = true;
10081                                 break;
10082                         }
10083                 }
10084                 if (! found) {
10085                         warningf(&statement->base.source_position,
10086                                  "enumeration value '%Y' not handled in switch",
10087                                  entry->base.symbol);
10088                 }
10089                 last_value = value;
10090         }
10091 }
10092
10093 /**
10094  * Parse a switch statement.
10095  */
10096 static statement_t *parse_switch(void)
10097 {
10098         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10099
10100         eat(T_switch);
10101
10102         PUSH_PARENT(statement);
10103
10104         expect('(', end_error);
10105         add_anchor_token(')');
10106         expression_t *const expr = parse_expression();
10107         mark_vars_read(expr, NULL);
10108         type_t       *      type = skip_typeref(expr->base.type);
10109         if (is_type_integer(type)) {
10110                 type = promote_integer(type);
10111                 if (warning.traditional) {
10112                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10113                                 warningf(&expr->base.source_position,
10114                                         "'%T' switch expression not converted to '%T' in ISO C",
10115                                         type, type_int);
10116                         }
10117                 }
10118         } else if (is_type_valid(type)) {
10119                 errorf(&expr->base.source_position,
10120                        "switch quantity is not an integer, but '%T'", type);
10121                 type = type_error_type;
10122         }
10123         statement->switchs.expression = create_implicit_cast(expr, type);
10124         expect(')', end_error);
10125         rem_anchor_token(')');
10126
10127         switch_statement_t *rem = current_switch;
10128         current_switch          = &statement->switchs;
10129         statement->switchs.body = parse_statement();
10130         current_switch          = rem;
10131
10132         if (warning.switch_default &&
10133             statement->switchs.default_label == NULL) {
10134                 warningf(&statement->base.source_position, "switch has no default case");
10135         }
10136         if (warning.switch_enum)
10137                 check_enum_cases(&statement->switchs);
10138
10139         POP_PARENT;
10140         return statement;
10141 end_error:
10142         POP_PARENT;
10143         return create_invalid_statement();
10144 }
10145
10146 static statement_t *parse_loop_body(statement_t *const loop)
10147 {
10148         statement_t *const rem = current_loop;
10149         current_loop = loop;
10150
10151         statement_t *const body = parse_statement();
10152
10153         current_loop = rem;
10154         return body;
10155 }
10156
10157 /**
10158  * Parse a while statement.
10159  */
10160 static statement_t *parse_while(void)
10161 {
10162         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10163
10164         eat(T_while);
10165
10166         PUSH_PARENT(statement);
10167
10168         expect('(', end_error);
10169         add_anchor_token(')');
10170         expression_t *const cond = parse_expression();
10171         statement->whiles.condition = cond;
10172         /* Â§6.8.5:2    The controlling expression of an iteration statement shall
10173          *             have scalar type. */
10174         semantic_condition(cond, "condition of 'while'-statement");
10175         mark_vars_read(cond, NULL);
10176         rem_anchor_token(')');
10177         expect(')', end_error);
10178
10179         statement->whiles.body = parse_loop_body(statement);
10180
10181         POP_PARENT;
10182         return statement;
10183 end_error:
10184         POP_PARENT;
10185         return create_invalid_statement();
10186 }
10187
10188 /**
10189  * Parse a do statement.
10190  */
10191 static statement_t *parse_do(void)
10192 {
10193         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10194
10195         eat(T_do);
10196
10197         PUSH_PARENT(statement);
10198
10199         add_anchor_token(T_while);
10200         statement->do_while.body = parse_loop_body(statement);
10201         rem_anchor_token(T_while);
10202
10203         expect(T_while, end_error);
10204         expect('(', end_error);
10205         add_anchor_token(')');
10206         expression_t *const cond = parse_expression();
10207         statement->do_while.condition = cond;
10208         /* Â§6.8.5:2    The controlling expression of an iteration statement shall
10209          *             have scalar type. */
10210         semantic_condition(cond, "condition of 'do-while'-statement");
10211         mark_vars_read(cond, NULL);
10212         rem_anchor_token(')');
10213         expect(')', end_error);
10214         expect(';', end_error);
10215
10216         POP_PARENT;
10217         return statement;
10218 end_error:
10219         POP_PARENT;
10220         return create_invalid_statement();
10221 }
10222
10223 /**
10224  * Parse a for statement.
10225  */
10226 static statement_t *parse_for(void)
10227 {
10228         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10229
10230         eat(T_for);
10231
10232         expect('(', end_error1);
10233         add_anchor_token(')');
10234
10235         PUSH_PARENT(statement);
10236
10237         size_t const  top       = environment_top();
10238         scope_t      *old_scope = scope_push(&statement->fors.scope);
10239
10240         if (token.type == ';') {
10241                 next_token();
10242         } else if (is_declaration_specifier(&token, false)) {
10243                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10244         } else {
10245                 add_anchor_token(';');
10246                 expression_t *const init = parse_expression();
10247                 statement->fors.initialisation = init;
10248                 mark_vars_read(init, ENT_ANY);
10249                 if (warning.unused_value && !expression_has_effect(init)) {
10250                         warningf(&init->base.source_position,
10251                                         "initialisation of 'for'-statement has no effect");
10252                 }
10253                 rem_anchor_token(';');
10254                 expect(';', end_error2);
10255         }
10256
10257         if (token.type != ';') {
10258                 add_anchor_token(';');
10259                 expression_t *const cond = parse_expression();
10260                 statement->fors.condition = cond;
10261                 /* Â§6.8.5:2    The controlling expression of an iteration statement
10262                  *             shall have scalar type. */
10263                 semantic_condition(cond, "condition of 'for'-statement");
10264                 mark_vars_read(cond, NULL);
10265                 rem_anchor_token(';');
10266         }
10267         expect(';', end_error2);
10268         if (token.type != ')') {
10269                 expression_t *const step = parse_expression();
10270                 statement->fors.step = step;
10271                 mark_vars_read(step, ENT_ANY);
10272                 if (warning.unused_value && !expression_has_effect(step)) {
10273                         warningf(&step->base.source_position,
10274                                  "step of 'for'-statement has no effect");
10275                 }
10276         }
10277         expect(')', end_error2);
10278         rem_anchor_token(')');
10279         statement->fors.body = parse_loop_body(statement);
10280
10281         assert(current_scope == &statement->fors.scope);
10282         scope_pop(old_scope);
10283         environment_pop_to(top);
10284
10285         POP_PARENT;
10286         return statement;
10287
10288 end_error2:
10289         POP_PARENT;
10290         rem_anchor_token(')');
10291         assert(current_scope == &statement->fors.scope);
10292         scope_pop(old_scope);
10293         environment_pop_to(top);
10294         /* fallthrough */
10295
10296 end_error1:
10297         return create_invalid_statement();
10298 }
10299
10300 /**
10301  * Parse a goto statement.
10302  */
10303 static statement_t *parse_goto(void)
10304 {
10305         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10306         eat(T_goto);
10307
10308         if (GNU_MODE && token.type == '*') {
10309                 next_token();
10310                 expression_t *expression = parse_expression();
10311                 mark_vars_read(expression, NULL);
10312
10313                 /* Argh: although documentation says the expression must be of type void*,
10314                  * gcc accepts anything that can be casted into void* without error */
10315                 type_t *type = expression->base.type;
10316
10317                 if (type != type_error_type) {
10318                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10319                                 errorf(&expression->base.source_position,
10320                                         "cannot convert to a pointer type");
10321                         } else if (warning.other && type != type_void_ptr) {
10322                                 warningf(&expression->base.source_position,
10323                                         "type of computed goto expression should be 'void*' not '%T'", type);
10324                         }
10325                         expression = create_implicit_cast(expression, type_void_ptr);
10326                 }
10327
10328                 statement->gotos.expression = expression;
10329         } else {
10330                 if (token.type != T_IDENTIFIER) {
10331                         if (GNU_MODE)
10332                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10333                         else
10334                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10335                         eat_until_anchor();
10336                         goto end_error;
10337                 }
10338                 symbol_t *symbol = token.v.symbol;
10339                 next_token();
10340
10341                 statement->gotos.label = get_label(symbol);
10342         }
10343
10344         /* remember the goto's in a list for later checking */
10345         *goto_anchor = &statement->gotos;
10346         goto_anchor  = &statement->gotos.next;
10347
10348         expect(';', end_error);
10349
10350         return statement;
10351 end_error:
10352         return create_invalid_statement();
10353 }
10354
10355 /**
10356  * Parse a continue statement.
10357  */
10358 static statement_t *parse_continue(void)
10359 {
10360         if (current_loop == NULL) {
10361                 errorf(HERE, "continue statement not within loop");
10362         }
10363
10364         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10365
10366         eat(T_continue);
10367         expect(';', end_error);
10368
10369 end_error:
10370         return statement;
10371 }
10372
10373 /**
10374  * Parse a break statement.
10375  */
10376 static statement_t *parse_break(void)
10377 {
10378         if (current_switch == NULL && current_loop == NULL) {
10379                 errorf(HERE, "break statement not within loop or switch");
10380         }
10381
10382         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10383
10384         eat(T_break);
10385         expect(';', end_error);
10386
10387 end_error:
10388         return statement;
10389 }
10390
10391 /**
10392  * Parse a __leave statement.
10393  */
10394 static statement_t *parse_leave_statement(void)
10395 {
10396         if (current_try == NULL) {
10397                 errorf(HERE, "__leave statement not within __try");
10398         }
10399
10400         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10401
10402         eat(T___leave);
10403         expect(';', end_error);
10404
10405 end_error:
10406         return statement;
10407 }
10408
10409 /**
10410  * Check if a given entity represents a local variable.
10411  */
10412 static bool is_local_variable(const entity_t *entity)
10413 {
10414         if (entity->kind != ENTITY_VARIABLE)
10415                 return false;
10416
10417         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10418         case STORAGE_CLASS_AUTO:
10419         case STORAGE_CLASS_REGISTER: {
10420                 const type_t *type = skip_typeref(entity->declaration.type);
10421                 if (is_type_function(type)) {
10422                         return false;
10423                 } else {
10424                         return true;
10425                 }
10426         }
10427         default:
10428                 return false;
10429         }
10430 }
10431
10432 /**
10433  * Check if a given expression represents a local variable.
10434  */
10435 static bool expression_is_local_variable(const expression_t *expression)
10436 {
10437         if (expression->base.kind != EXPR_REFERENCE) {
10438                 return false;
10439         }
10440         const entity_t *entity = expression->reference.entity;
10441         return is_local_variable(entity);
10442 }
10443
10444 /**
10445  * Check if a given expression represents a local variable and
10446  * return its declaration then, else return NULL.
10447  */
10448 entity_t *expression_is_variable(const expression_t *expression)
10449 {
10450         if (expression->base.kind != EXPR_REFERENCE) {
10451                 return NULL;
10452         }
10453         entity_t *entity = expression->reference.entity;
10454         if (entity->kind != ENTITY_VARIABLE)
10455                 return NULL;
10456
10457         return entity;
10458 }
10459
10460 /**
10461  * Parse a return statement.
10462  */
10463 static statement_t *parse_return(void)
10464 {
10465         eat(T_return);
10466
10467         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10468
10469         expression_t *return_value = NULL;
10470         if (token.type != ';') {
10471                 return_value = parse_expression();
10472                 mark_vars_read(return_value, NULL);
10473         }
10474
10475         const type_t *const func_type = skip_typeref(current_function->base.type);
10476         assert(is_type_function(func_type));
10477         type_t *const return_type = skip_typeref(func_type->function.return_type);
10478
10479         source_position_t const *const pos = &statement->base.source_position;
10480         if (return_value != NULL) {
10481                 type_t *return_value_type = skip_typeref(return_value->base.type);
10482
10483                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10484                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10485                                 /* ISO/IEC 14882:1998(E) Â§6.6.3:2 */
10486                                 /* Only warn in C mode, because GCC does the same */
10487                                 if (c_mode & _CXX || strict_mode) {
10488                                         errorf(pos,
10489                                                         "'return' with a value, in function returning 'void'");
10490                                 } else if (warning.other) {
10491                                         warningf(pos,
10492                                                         "'return' with a value, in function returning 'void'");
10493                                 }
10494                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) Â§6.6.3:3 */
10495                                 /* Only warn in C mode, because GCC does the same */
10496                                 if (strict_mode) {
10497                                         errorf(pos,
10498                                                         "'return' with expression in function return 'void'");
10499                                 } else if (warning.other) {
10500                                         warningf(pos,
10501                                                         "'return' with expression in function return 'void'");
10502                                 }
10503                         }
10504                 } else {
10505                         assign_error_t error = semantic_assign(return_type, return_value);
10506                         report_assign_error(error, return_type, return_value, "'return'",
10507                                         pos);
10508                 }
10509                 return_value = create_implicit_cast(return_value, return_type);
10510                 /* check for returning address of a local var */
10511                 if (warning.other && return_value != NULL
10512                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10513                         const expression_t *expression = return_value->unary.value;
10514                         if (expression_is_local_variable(expression)) {
10515                                 warningf(pos, "function returns address of local variable");
10516                         }
10517                 }
10518         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10519                 /* ISO/IEC 14882:1998(E) Â§6.6.3:3 */
10520                 if (c_mode & _CXX || strict_mode) {
10521                         errorf(pos,
10522                                         "'return' without value, in function returning non-void");
10523                 } else {
10524                         warningf(pos,
10525                                         "'return' without value, in function returning non-void");
10526                 }
10527         }
10528         statement->returns.value = return_value;
10529
10530         expect(';', end_error);
10531
10532 end_error:
10533         return statement;
10534 }
10535
10536 /**
10537  * Parse a declaration statement.
10538  */
10539 static statement_t *parse_declaration_statement(void)
10540 {
10541         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10542
10543         entity_t *before = current_scope->last_entity;
10544         if (GNU_MODE) {
10545                 parse_external_declaration();
10546         } else {
10547                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10548         }
10549
10550         if (before == NULL) {
10551                 statement->declaration.declarations_begin = current_scope->entities;
10552         } else {
10553                 statement->declaration.declarations_begin = before->base.next;
10554         }
10555         statement->declaration.declarations_end = current_scope->last_entity;
10556
10557         return statement;
10558 }
10559
10560 /**
10561  * Parse an expression statement, ie. expr ';'.
10562  */
10563 static statement_t *parse_expression_statement(void)
10564 {
10565         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10566
10567         expression_t *const expr         = parse_expression();
10568         statement->expression.expression = expr;
10569         mark_vars_read(expr, ENT_ANY);
10570
10571         expect(';', end_error);
10572
10573 end_error:
10574         return statement;
10575 }
10576
10577 /**
10578  * Parse a microsoft __try { } __finally { } or
10579  * __try{ } __except() { }
10580  */
10581 static statement_t *parse_ms_try_statment(void)
10582 {
10583         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10584         eat(T___try);
10585
10586         PUSH_PARENT(statement);
10587
10588         ms_try_statement_t *rem = current_try;
10589         current_try = &statement->ms_try;
10590         statement->ms_try.try_statement = parse_compound_statement(false);
10591         current_try = rem;
10592
10593         POP_PARENT;
10594
10595         if (token.type == T___except) {
10596                 eat(T___except);
10597                 expect('(', end_error);
10598                 add_anchor_token(')');
10599                 expression_t *const expr = parse_expression();
10600                 mark_vars_read(expr, NULL);
10601                 type_t       *      type = skip_typeref(expr->base.type);
10602                 if (is_type_integer(type)) {
10603                         type = promote_integer(type);
10604                 } else if (is_type_valid(type)) {
10605                         errorf(&expr->base.source_position,
10606                                "__expect expression is not an integer, but '%T'", type);
10607                         type = type_error_type;
10608                 }
10609                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10610                 rem_anchor_token(')');
10611                 expect(')', end_error);
10612                 statement->ms_try.final_statement = parse_compound_statement(false);
10613         } else if (token.type == T__finally) {
10614                 eat(T___finally);
10615                 statement->ms_try.final_statement = parse_compound_statement(false);
10616         } else {
10617                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10618                 return create_invalid_statement();
10619         }
10620         return statement;
10621 end_error:
10622         return create_invalid_statement();
10623 }
10624
10625 static statement_t *parse_empty_statement(void)
10626 {
10627         if (warning.empty_statement) {
10628                 warningf(HERE, "statement is empty");
10629         }
10630         statement_t *const statement = create_empty_statement();
10631         eat(';');
10632         return statement;
10633 }
10634
10635 static statement_t *parse_local_label_declaration(void)
10636 {
10637         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10638
10639         eat(T___label__);
10640
10641         entity_t *begin = NULL, *end = NULL;
10642
10643         while (true) {
10644                 if (token.type != T_IDENTIFIER) {
10645                         parse_error_expected("while parsing local label declaration",
10646                                 T_IDENTIFIER, NULL);
10647                         goto end_error;
10648                 }
10649                 symbol_t *symbol = token.v.symbol;
10650                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10651                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10652                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10653                                symbol, &entity->base.source_position);
10654                 } else {
10655                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10656
10657                         entity->base.parent_scope    = current_scope;
10658                         entity->base.namespc         = NAMESPACE_LABEL;
10659                         entity->base.source_position = token.source_position;
10660                         entity->base.symbol          = symbol;
10661
10662                         if (end != NULL)
10663                                 end->base.next = entity;
10664                         end = entity;
10665                         if (begin == NULL)
10666                                 begin = entity;
10667
10668                         environment_push(entity);
10669                 }
10670                 next_token();
10671
10672                 if (token.type != ',')
10673                         break;
10674                 next_token();
10675         }
10676         eat(';');
10677 end_error:
10678         statement->declaration.declarations_begin = begin;
10679         statement->declaration.declarations_end   = end;
10680         return statement;
10681 }
10682
10683 static void parse_namespace_definition(void)
10684 {
10685         eat(T_namespace);
10686
10687         entity_t *entity = NULL;
10688         symbol_t *symbol = NULL;
10689
10690         if (token.type == T_IDENTIFIER) {
10691                 symbol = token.v.symbol;
10692                 next_token();
10693
10694                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10695                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10696                                 && entity->base.parent_scope == current_scope) {
10697                         error_redefined_as_different_kind(&token.source_position,
10698                                                           entity, ENTITY_NAMESPACE);
10699                         entity = NULL;
10700                 }
10701         }
10702
10703         if (entity == NULL) {
10704                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10705                 entity->base.symbol          = symbol;
10706                 entity->base.source_position = token.source_position;
10707                 entity->base.namespc         = NAMESPACE_NORMAL;
10708                 entity->base.parent_scope    = current_scope;
10709         }
10710
10711         if (token.type == '=') {
10712                 /* TODO: parse namespace alias */
10713                 panic("namespace alias definition not supported yet");
10714         }
10715
10716         environment_push(entity);
10717         append_entity(current_scope, entity);
10718
10719         size_t const  top       = environment_top();
10720         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10721
10722         expect('{', end_error);
10723         parse_externals();
10724         expect('}', end_error);
10725
10726 end_error:
10727         assert(current_scope == &entity->namespacee.members);
10728         scope_pop(old_scope);
10729         environment_pop_to(top);
10730 }
10731
10732 /**
10733  * Parse a statement.
10734  * There's also parse_statement() which additionally checks for
10735  * "statement has no effect" warnings
10736  */
10737 static statement_t *intern_parse_statement(void)
10738 {
10739         statement_t *statement = NULL;
10740
10741         /* declaration or statement */
10742         add_anchor_token(';');
10743         switch (token.type) {
10744         case T_IDENTIFIER: {
10745                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10746                 if (la1_type == ':') {
10747                         statement = parse_label_statement();
10748                 } else if (is_typedef_symbol(token.v.symbol)) {
10749                         statement = parse_declaration_statement();
10750                 } else {
10751                         /* it's an identifier, the grammar says this must be an
10752                          * expression statement. However it is common that users mistype
10753                          * declaration types, so we guess a bit here to improve robustness
10754                          * for incorrect programs */
10755                         switch (la1_type) {
10756                         case '&':
10757                         case '*':
10758                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10759                                         goto expression_statment;
10760                                 /* FALLTHROUGH */
10761
10762                         DECLARATION_START
10763                         case T_IDENTIFIER:
10764                                 statement = parse_declaration_statement();
10765                                 break;
10766
10767                         default:
10768 expression_statment:
10769                                 statement = parse_expression_statement();
10770                                 break;
10771                         }
10772                 }
10773                 break;
10774         }
10775
10776         case T___extension__:
10777                 /* This can be a prefix to a declaration or an expression statement.
10778                  * We simply eat it now and parse the rest with tail recursion. */
10779                 do {
10780                         next_token();
10781                 } while (token.type == T___extension__);
10782                 bool old_gcc_extension = in_gcc_extension;
10783                 in_gcc_extension       = true;
10784                 statement = intern_parse_statement();
10785                 in_gcc_extension = old_gcc_extension;
10786                 break;
10787
10788         DECLARATION_START
10789                 statement = parse_declaration_statement();
10790                 break;
10791
10792         case T___label__:
10793                 statement = parse_local_label_declaration();
10794                 break;
10795
10796         case ';':         statement = parse_empty_statement();         break;
10797         case '{':         statement = parse_compound_statement(false); break;
10798         case T___leave:   statement = parse_leave_statement();         break;
10799         case T___try:     statement = parse_ms_try_statment();         break;
10800         case T_asm:       statement = parse_asm_statement();           break;
10801         case T_break:     statement = parse_break();                   break;
10802         case T_case:      statement = parse_case_statement();          break;
10803         case T_continue:  statement = parse_continue();                break;
10804         case T_default:   statement = parse_default_statement();       break;
10805         case T_do:        statement = parse_do();                      break;
10806         case T_for:       statement = parse_for();                     break;
10807         case T_goto:      statement = parse_goto();                    break;
10808         case T_if:        statement = parse_if();                      break;
10809         case T_return:    statement = parse_return();                  break;
10810         case T_switch:    statement = parse_switch();                  break;
10811         case T_while:     statement = parse_while();                   break;
10812
10813         EXPRESSION_START
10814                 statement = parse_expression_statement();
10815                 break;
10816
10817         default:
10818                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10819                 statement = create_invalid_statement();
10820                 if (!at_anchor())
10821                         next_token();
10822                 break;
10823         }
10824         rem_anchor_token(';');
10825
10826         assert(statement != NULL
10827                         && statement->base.source_position.input_name != NULL);
10828
10829         return statement;
10830 }
10831
10832 /**
10833  * parse a statement and emits "statement has no effect" warning if needed
10834  * (This is really a wrapper around intern_parse_statement with check for 1
10835  *  single warning. It is needed, because for statement expressions we have
10836  *  to avoid the warning on the last statement)
10837  */
10838 static statement_t *parse_statement(void)
10839 {
10840         statement_t *statement = intern_parse_statement();
10841
10842         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10843                 expression_t *expression = statement->expression.expression;
10844                 if (!expression_has_effect(expression)) {
10845                         warningf(&expression->base.source_position,
10846                                         "statement has no effect");
10847                 }
10848         }
10849
10850         return statement;
10851 }
10852
10853 /**
10854  * Parse a compound statement.
10855  */
10856 static statement_t *parse_compound_statement(bool inside_expression_statement)
10857 {
10858         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10859
10860         PUSH_PARENT(statement);
10861
10862         eat('{');
10863         add_anchor_token('}');
10864         /* tokens, which can start a statement */
10865         /* TODO MS, __builtin_FOO */
10866         add_anchor_token('!');
10867         add_anchor_token('&');
10868         add_anchor_token('(');
10869         add_anchor_token('*');
10870         add_anchor_token('+');
10871         add_anchor_token('-');
10872         add_anchor_token('{');
10873         add_anchor_token('~');
10874         add_anchor_token(T_CHARACTER_CONSTANT);
10875         add_anchor_token(T_COLONCOLON);
10876         add_anchor_token(T_FLOATINGPOINT);
10877         add_anchor_token(T_IDENTIFIER);
10878         add_anchor_token(T_INTEGER);
10879         add_anchor_token(T_MINUSMINUS);
10880         add_anchor_token(T_PLUSPLUS);
10881         add_anchor_token(T_STRING_LITERAL);
10882         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10883         add_anchor_token(T_WIDE_STRING_LITERAL);
10884         add_anchor_token(T__Bool);
10885         add_anchor_token(T__Complex);
10886         add_anchor_token(T__Imaginary);
10887         add_anchor_token(T___FUNCTION__);
10888         add_anchor_token(T___PRETTY_FUNCTION__);
10889         add_anchor_token(T___alignof__);
10890         add_anchor_token(T___attribute__);
10891         add_anchor_token(T___builtin_va_start);
10892         add_anchor_token(T___extension__);
10893         add_anchor_token(T___func__);
10894         add_anchor_token(T___imag__);
10895         add_anchor_token(T___label__);
10896         add_anchor_token(T___real__);
10897         add_anchor_token(T___thread);
10898         add_anchor_token(T_asm);
10899         add_anchor_token(T_auto);
10900         add_anchor_token(T_bool);
10901         add_anchor_token(T_break);
10902         add_anchor_token(T_case);
10903         add_anchor_token(T_char);
10904         add_anchor_token(T_class);
10905         add_anchor_token(T_const);
10906         add_anchor_token(T_const_cast);
10907         add_anchor_token(T_continue);
10908         add_anchor_token(T_default);
10909         add_anchor_token(T_delete);
10910         add_anchor_token(T_double);
10911         add_anchor_token(T_do);
10912         add_anchor_token(T_dynamic_cast);
10913         add_anchor_token(T_enum);
10914         add_anchor_token(T_extern);
10915         add_anchor_token(T_false);
10916         add_anchor_token(T_float);
10917         add_anchor_token(T_for);
10918         add_anchor_token(T_goto);
10919         add_anchor_token(T_if);
10920         add_anchor_token(T_inline);
10921         add_anchor_token(T_int);
10922         add_anchor_token(T_long);
10923         add_anchor_token(T_new);
10924         add_anchor_token(T_operator);
10925         add_anchor_token(T_register);
10926         add_anchor_token(T_reinterpret_cast);
10927         add_anchor_token(T_restrict);
10928         add_anchor_token(T_return);
10929         add_anchor_token(T_short);
10930         add_anchor_token(T_signed);
10931         add_anchor_token(T_sizeof);
10932         add_anchor_token(T_static);
10933         add_anchor_token(T_static_cast);
10934         add_anchor_token(T_struct);
10935         add_anchor_token(T_switch);
10936         add_anchor_token(T_template);
10937         add_anchor_token(T_this);
10938         add_anchor_token(T_throw);
10939         add_anchor_token(T_true);
10940         add_anchor_token(T_try);
10941         add_anchor_token(T_typedef);
10942         add_anchor_token(T_typeid);
10943         add_anchor_token(T_typename);
10944         add_anchor_token(T_typeof);
10945         add_anchor_token(T_union);
10946         add_anchor_token(T_unsigned);
10947         add_anchor_token(T_using);
10948         add_anchor_token(T_void);
10949         add_anchor_token(T_volatile);
10950         add_anchor_token(T_wchar_t);
10951         add_anchor_token(T_while);
10952
10953         size_t const  top       = environment_top();
10954         scope_t      *old_scope = scope_push(&statement->compound.scope);
10955
10956         statement_t **anchor            = &statement->compound.statements;
10957         bool          only_decls_so_far = true;
10958         while (token.type != '}') {
10959                 if (token.type == T_EOF) {
10960                         errorf(&statement->base.source_position,
10961                                "EOF while parsing compound statement");
10962                         break;
10963                 }
10964                 statement_t *sub_statement = intern_parse_statement();
10965                 if (is_invalid_statement(sub_statement)) {
10966                         /* an error occurred. if we are at an anchor, return */
10967                         if (at_anchor())
10968                                 goto end_error;
10969                         continue;
10970                 }
10971
10972                 if (warning.declaration_after_statement) {
10973                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10974                                 only_decls_so_far = false;
10975                         } else if (!only_decls_so_far) {
10976                                 warningf(&sub_statement->base.source_position,
10977                                          "ISO C90 forbids mixed declarations and code");
10978                         }
10979                 }
10980
10981                 *anchor = sub_statement;
10982
10983                 while (sub_statement->base.next != NULL)
10984                         sub_statement = sub_statement->base.next;
10985
10986                 anchor = &sub_statement->base.next;
10987         }
10988         next_token();
10989
10990         /* look over all statements again to produce no effect warnings */
10991         if (warning.unused_value) {
10992                 statement_t *sub_statement = statement->compound.statements;
10993                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10994                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10995                                 continue;
10996                         /* don't emit a warning for the last expression in an expression
10997                          * statement as it has always an effect */
10998                         if (inside_expression_statement && sub_statement->base.next == NULL)
10999                                 continue;
11000
11001                         expression_t *expression = sub_statement->expression.expression;
11002                         if (!expression_has_effect(expression)) {
11003                                 warningf(&expression->base.source_position,
11004                                          "statement has no effect");
11005                         }
11006                 }
11007         }
11008
11009 end_error:
11010         rem_anchor_token(T_while);
11011         rem_anchor_token(T_wchar_t);
11012         rem_anchor_token(T_volatile);
11013         rem_anchor_token(T_void);
11014         rem_anchor_token(T_using);
11015         rem_anchor_token(T_unsigned);
11016         rem_anchor_token(T_union);
11017         rem_anchor_token(T_typeof);
11018         rem_anchor_token(T_typename);
11019         rem_anchor_token(T_typeid);
11020         rem_anchor_token(T_typedef);
11021         rem_anchor_token(T_try);
11022         rem_anchor_token(T_true);
11023         rem_anchor_token(T_throw);
11024         rem_anchor_token(T_this);
11025         rem_anchor_token(T_template);
11026         rem_anchor_token(T_switch);
11027         rem_anchor_token(T_struct);
11028         rem_anchor_token(T_static_cast);
11029         rem_anchor_token(T_static);
11030         rem_anchor_token(T_sizeof);
11031         rem_anchor_token(T_signed);
11032         rem_anchor_token(T_short);
11033         rem_anchor_token(T_return);
11034         rem_anchor_token(T_restrict);
11035         rem_anchor_token(T_reinterpret_cast);
11036         rem_anchor_token(T_register);
11037         rem_anchor_token(T_operator);
11038         rem_anchor_token(T_new);
11039         rem_anchor_token(T_long);
11040         rem_anchor_token(T_int);
11041         rem_anchor_token(T_inline);
11042         rem_anchor_token(T_if);
11043         rem_anchor_token(T_goto);
11044         rem_anchor_token(T_for);
11045         rem_anchor_token(T_float);
11046         rem_anchor_token(T_false);
11047         rem_anchor_token(T_extern);
11048         rem_anchor_token(T_enum);
11049         rem_anchor_token(T_dynamic_cast);
11050         rem_anchor_token(T_do);
11051         rem_anchor_token(T_double);
11052         rem_anchor_token(T_delete);
11053         rem_anchor_token(T_default);
11054         rem_anchor_token(T_continue);
11055         rem_anchor_token(T_const_cast);
11056         rem_anchor_token(T_const);
11057         rem_anchor_token(T_class);
11058         rem_anchor_token(T_char);
11059         rem_anchor_token(T_case);
11060         rem_anchor_token(T_break);
11061         rem_anchor_token(T_bool);
11062         rem_anchor_token(T_auto);
11063         rem_anchor_token(T_asm);
11064         rem_anchor_token(T___thread);
11065         rem_anchor_token(T___real__);
11066         rem_anchor_token(T___label__);
11067         rem_anchor_token(T___imag__);
11068         rem_anchor_token(T___func__);
11069         rem_anchor_token(T___extension__);
11070         rem_anchor_token(T___builtin_va_start);
11071         rem_anchor_token(T___attribute__);
11072         rem_anchor_token(T___alignof__);
11073         rem_anchor_token(T___PRETTY_FUNCTION__);
11074         rem_anchor_token(T___FUNCTION__);
11075         rem_anchor_token(T__Imaginary);
11076         rem_anchor_token(T__Complex);
11077         rem_anchor_token(T__Bool);
11078         rem_anchor_token(T_WIDE_STRING_LITERAL);
11079         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11080         rem_anchor_token(T_STRING_LITERAL);
11081         rem_anchor_token(T_PLUSPLUS);
11082         rem_anchor_token(T_MINUSMINUS);
11083         rem_anchor_token(T_INTEGER);
11084         rem_anchor_token(T_IDENTIFIER);
11085         rem_anchor_token(T_FLOATINGPOINT);
11086         rem_anchor_token(T_COLONCOLON);
11087         rem_anchor_token(T_CHARACTER_CONSTANT);
11088         rem_anchor_token('~');
11089         rem_anchor_token('{');
11090         rem_anchor_token('-');
11091         rem_anchor_token('+');
11092         rem_anchor_token('*');
11093         rem_anchor_token('(');
11094         rem_anchor_token('&');
11095         rem_anchor_token('!');
11096         rem_anchor_token('}');
11097         assert(current_scope == &statement->compound.scope);
11098         scope_pop(old_scope);
11099         environment_pop_to(top);
11100
11101         POP_PARENT;
11102         return statement;
11103 }
11104
11105 /**
11106  * Check for unused global static functions and variables
11107  */
11108 static void check_unused_globals(void)
11109 {
11110         if (!warning.unused_function && !warning.unused_variable)
11111                 return;
11112
11113         for (const entity_t *entity = file_scope->entities; entity != NULL;
11114              entity = entity->base.next) {
11115                 if (!is_declaration(entity))
11116                         continue;
11117
11118                 const declaration_t *declaration = &entity->declaration;
11119                 if (declaration->used                  ||
11120                     declaration->modifiers & DM_UNUSED ||
11121                     declaration->modifiers & DM_USED   ||
11122                     declaration->storage_class != STORAGE_CLASS_STATIC)
11123                         continue;
11124
11125                 type_t *const type = declaration->type;
11126                 const char *s;
11127                 if (entity->kind == ENTITY_FUNCTION) {
11128                         /* inhibit warning for static inline functions */
11129                         if (entity->function.is_inline)
11130                                 continue;
11131
11132                         s = entity->function.statement != NULL ? "defined" : "declared";
11133                 } else {
11134                         s = "defined";
11135                 }
11136
11137                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11138                         type, declaration->base.symbol, s);
11139         }
11140 }
11141
11142 static void parse_global_asm(void)
11143 {
11144         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11145
11146         eat(T_asm);
11147         expect('(', end_error);
11148
11149         statement->asms.asm_text = parse_string_literals();
11150         statement->base.next     = unit->global_asm;
11151         unit->global_asm         = statement;
11152
11153         expect(')', end_error);
11154         expect(';', end_error);
11155
11156 end_error:;
11157 }
11158
11159 static void parse_linkage_specification(void)
11160 {
11161         eat(T_extern);
11162         assert(token.type == T_STRING_LITERAL);
11163
11164         const char *linkage = parse_string_literals().begin;
11165
11166         linkage_kind_t old_linkage = current_linkage;
11167         linkage_kind_t new_linkage;
11168         if (strcmp(linkage, "C") == 0) {
11169                 new_linkage = LINKAGE_C;
11170         } else if (strcmp(linkage, "C++") == 0) {
11171                 new_linkage = LINKAGE_CXX;
11172         } else {
11173                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11174                 new_linkage = LINKAGE_INVALID;
11175         }
11176         current_linkage = new_linkage;
11177
11178         if (token.type == '{') {
11179                 next_token();
11180                 parse_externals();
11181                 expect('}', end_error);
11182         } else {
11183                 parse_external();
11184         }
11185
11186 end_error:
11187         assert(current_linkage == new_linkage);
11188         current_linkage = old_linkage;
11189 }
11190
11191 static void parse_external(void)
11192 {
11193         switch (token.type) {
11194                 DECLARATION_START_NO_EXTERN
11195                 case T_IDENTIFIER:
11196                 case T___extension__:
11197                 /* tokens below are for implicit int */
11198                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11199                              implicit int) */
11200                 case '*': /* * x; -> int* x; */
11201                 case '(': /* (x); -> int (x); */
11202                         parse_external_declaration();
11203                         return;
11204
11205                 case T_extern:
11206                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11207                                 parse_linkage_specification();
11208                         } else {
11209                                 parse_external_declaration();
11210                         }
11211                         return;
11212
11213                 case T_asm:
11214                         parse_global_asm();
11215                         return;
11216
11217                 case T_namespace:
11218                         parse_namespace_definition();
11219                         return;
11220
11221                 case ';':
11222                         if (!strict_mode) {
11223                                 if (warning.other)
11224                                         warningf(HERE, "stray ';' outside of function");
11225                                 next_token();
11226                                 return;
11227                         }
11228                         /* FALLTHROUGH */
11229
11230                 default:
11231                         errorf(HERE, "stray %K outside of function", &token);
11232                         if (token.type == '(' || token.type == '{' || token.type == '[')
11233                                 eat_until_matching_token(token.type);
11234                         next_token();
11235                         return;
11236         }
11237 }
11238
11239 static void parse_externals(void)
11240 {
11241         add_anchor_token('}');
11242         add_anchor_token(T_EOF);
11243
11244 #ifndef NDEBUG
11245         unsigned char token_anchor_copy[T_LAST_TOKEN];
11246         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11247 #endif
11248
11249         while (token.type != T_EOF && token.type != '}') {
11250 #ifndef NDEBUG
11251                 bool anchor_leak = false;
11252                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11253                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11254                         if (count != 0) {
11255                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11256                                 anchor_leak = true;
11257                         }
11258                 }
11259                 if (in_gcc_extension) {
11260                         errorf(HERE, "Leaked __extension__");
11261                         anchor_leak = true;
11262                 }
11263
11264                 if (anchor_leak)
11265                         abort();
11266 #endif
11267
11268                 parse_external();
11269         }
11270
11271         rem_anchor_token(T_EOF);
11272         rem_anchor_token('}');
11273 }
11274
11275 /**
11276  * Parse a translation unit.
11277  */
11278 static void parse_translation_unit(void)
11279 {
11280         add_anchor_token(T_EOF);
11281
11282         while (true) {
11283                 parse_externals();
11284
11285                 if (token.type == T_EOF)
11286                         break;
11287
11288                 errorf(HERE, "stray %K outside of function", &token);
11289                 if (token.type == '(' || token.type == '{' || token.type == '[')
11290                         eat_until_matching_token(token.type);
11291                 next_token();
11292         }
11293 }
11294
11295 /**
11296  * Parse the input.
11297  *
11298  * @return  the translation unit or NULL if errors occurred.
11299  */
11300 void start_parsing(void)
11301 {
11302         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11303         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11304         diagnostic_count  = 0;
11305         error_count       = 0;
11306         warning_count     = 0;
11307
11308         type_set_output(stderr);
11309         ast_set_output(stderr);
11310
11311         assert(unit == NULL);
11312         unit = allocate_ast_zero(sizeof(unit[0]));
11313
11314         assert(file_scope == NULL);
11315         file_scope = &unit->scope;
11316
11317         assert(current_scope == NULL);
11318         scope_push(&unit->scope);
11319 }
11320
11321 translation_unit_t *finish_parsing(void)
11322 {
11323         assert(current_scope == &unit->scope);
11324         scope_pop(NULL);
11325
11326         assert(file_scope == &unit->scope);
11327         check_unused_globals();
11328         file_scope = NULL;
11329
11330         DEL_ARR_F(environment_stack);
11331         DEL_ARR_F(label_stack);
11332
11333         translation_unit_t *result = unit;
11334         unit = NULL;
11335         return result;
11336 }
11337
11338 /* GCC allows global arrays without size and assigns them a length of one,
11339  * if no different declaration follows */
11340 static void complete_incomplete_arrays(void)
11341 {
11342         size_t n = ARR_LEN(incomplete_arrays);
11343         for (size_t i = 0; i != n; ++i) {
11344                 declaration_t *const decl      = incomplete_arrays[i];
11345                 type_t        *const orig_type = decl->type;
11346                 type_t        *const type      = skip_typeref(orig_type);
11347
11348                 if (!is_type_incomplete(type))
11349                         continue;
11350
11351                 if (warning.other) {
11352                         warningf(&decl->base.source_position,
11353                                         "array '%#T' assumed to have one element",
11354                                         orig_type, decl->base.symbol);
11355                 }
11356
11357                 type_t *const new_type = duplicate_type(type);
11358                 new_type->array.size_constant     = true;
11359                 new_type->array.has_implicit_size = true;
11360                 new_type->array.size              = 1;
11361
11362                 type_t *const result = typehash_insert(new_type);
11363                 if (type != result)
11364                         free_type(type);
11365
11366                 decl->type = result;
11367         }
11368 }
11369
11370 void parse(void)
11371 {
11372         lookahead_bufpos = 0;
11373         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11374                 next_token();
11375         }
11376         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11377         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11378         parse_translation_unit();
11379         complete_incomplete_arrays();
11380         DEL_ARR_F(incomplete_arrays);
11381         incomplete_arrays = NULL;
11382 }
11383
11384 /**
11385  * Initialize the parser.
11386  */
11387 void init_parser(void)
11388 {
11389         sym_anonymous = symbol_table_insert("<anonymous>");
11390
11391         if (c_mode & _MS) {
11392                 /* add predefined symbols for extended-decl-modifier */
11393                 sym_align         = symbol_table_insert("align");
11394                 sym_allocate      = symbol_table_insert("allocate");
11395                 sym_dllimport     = symbol_table_insert("dllimport");
11396                 sym_dllexport     = symbol_table_insert("dllexport");
11397                 sym_naked         = symbol_table_insert("naked");
11398                 sym_noinline      = symbol_table_insert("noinline");
11399                 sym_returns_twice = symbol_table_insert("returns_twice");
11400                 sym_noreturn      = symbol_table_insert("noreturn");
11401                 sym_nothrow       = symbol_table_insert("nothrow");
11402                 sym_novtable      = symbol_table_insert("novtable");
11403                 sym_property      = symbol_table_insert("property");
11404                 sym_get           = symbol_table_insert("get");
11405                 sym_put           = symbol_table_insert("put");
11406                 sym_selectany     = symbol_table_insert("selectany");
11407                 sym_thread        = symbol_table_insert("thread");
11408                 sym_uuid          = symbol_table_insert("uuid");
11409                 sym_deprecated    = symbol_table_insert("deprecated");
11410                 sym_restrict      = symbol_table_insert("restrict");
11411                 sym_noalias       = symbol_table_insert("noalias");
11412         }
11413         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11414
11415         init_expression_parsers();
11416         obstack_init(&temp_obst);
11417
11418         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11419         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11420 }
11421
11422 /**
11423  * Terminate the parser.
11424  */
11425 void exit_parser(void)
11426 {
11427         obstack_free(&temp_obst, NULL);
11428 }