ast2firm: Factorise code to convert a value to its storage type.
[cparser] / ast.c
1 /*
2  * This file is part of cparser.
3  * Copyright (C) 2007-2009 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 "ast_t.h"
23 #include "symbol_t.h"
24 #include "type_t.h"
25 #include "parser.h"
26 #include "lang_features.h"
27 #include "entity_t.h"
28 #include "printer.h"
29 #include "separator_t.h"
30 #include "types.h"
31
32 #include <assert.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <ctype.h>
36
37 #if defined(__INTEL_COMPILER)
38 #include <mathimf.h>
39 #elif defined(__CYGWIN__)
40 #include "win32/cygwin_math_ext.h"
41 #else
42 #include <math.h>
43 #endif
44
45 #include "adt/error.h"
46 #include "adt/util.h"
47
48 struct obstack ast_obstack;
49
50 static int indent;
51 static int case_indent;
52
53 bool print_implicit_casts = false;
54 bool print_parenthesis = false;
55
56 static void print_statement(const statement_t *statement);
57 static void print_expression_prec(const expression_t *expression, unsigned prec);
58
59 void change_indent(int delta)
60 {
61         indent += delta;
62         assert(indent >= 0);
63 }
64
65 void print_indent(void)
66 {
67         for (int i = 0; i < indent; ++i)
68                 print_char('\t');
69 }
70
71 /**
72  * Returns 1 if a given precedence level has right-to-left
73  * associativity, else 0.
74  *
75  * @param precedence   the operator precedence
76  */
77 static int right_to_left(unsigned precedence)
78 {
79         switch (precedence) {
80         case PREC_ASSIGNMENT:
81         case PREC_CONDITIONAL:
82         case PREC_UNARY:
83                 return 1;
84
85         default:
86                 return 0;
87         }
88 }
89
90 /**
91  * Return the precedence of an expression given by its kind.
92  *
93  * @param kind   the expression kind
94  */
95 static unsigned get_expression_precedence(expression_kind_t kind)
96 {
97         static const unsigned prec[] = {
98                 [EXPR_ERROR]                      = PREC_PRIMARY,
99                 [EXPR_REFERENCE]                  = PREC_PRIMARY,
100                 [EXPR_ENUM_CONSTANT]              = PREC_PRIMARY,
101                 [EXPR_LITERAL_INTEGER]            = PREC_PRIMARY,
102                 [EXPR_LITERAL_FLOATINGPOINT]      = PREC_PRIMARY,
103                 [EXPR_LITERAL_CHARACTER]          = PREC_PRIMARY,
104                 [EXPR_LITERAL_MS_NOOP]            = PREC_PRIMARY,
105                 [EXPR_STRING_LITERAL]             = PREC_PRIMARY,
106                 [EXPR_COMPOUND_LITERAL]           = PREC_UNARY,
107                 [EXPR_CALL]                       = PREC_POSTFIX,
108                 [EXPR_CONDITIONAL]                = PREC_CONDITIONAL,
109                 [EXPR_SELECT]                     = PREC_POSTFIX,
110                 [EXPR_ARRAY_ACCESS]               = PREC_POSTFIX,
111                 [EXPR_SIZEOF]                     = PREC_UNARY,
112                 [EXPR_CLASSIFY_TYPE]              = PREC_UNARY,
113                 [EXPR_ALIGNOF]                    = PREC_UNARY,
114
115                 [EXPR_FUNCNAME]                   = PREC_PRIMARY,
116                 [EXPR_BUILTIN_CONSTANT_P]         = PREC_PRIMARY,
117                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = PREC_PRIMARY,
118                 [EXPR_OFFSETOF]                   = PREC_PRIMARY,
119                 [EXPR_VA_START]                   = PREC_PRIMARY,
120                 [EXPR_VA_ARG]                     = PREC_PRIMARY,
121                 [EXPR_VA_COPY]                    = PREC_PRIMARY,
122                 [EXPR_STATEMENT]                  = PREC_PRIMARY,
123                 [EXPR_LABEL_ADDRESS]              = PREC_PRIMARY,
124
125                 [EXPR_UNARY_NEGATE]               = PREC_UNARY,
126                 [EXPR_UNARY_PLUS]                 = PREC_UNARY,
127                 [EXPR_UNARY_BITWISE_NEGATE]       = PREC_UNARY,
128                 [EXPR_UNARY_NOT]                  = PREC_UNARY,
129                 [EXPR_UNARY_DEREFERENCE]          = PREC_UNARY,
130                 [EXPR_UNARY_TAKE_ADDRESS]         = PREC_UNARY,
131                 [EXPR_UNARY_POSTFIX_INCREMENT]    = PREC_POSTFIX,
132                 [EXPR_UNARY_POSTFIX_DECREMENT]    = PREC_POSTFIX,
133                 [EXPR_UNARY_PREFIX_INCREMENT]     = PREC_UNARY,
134                 [EXPR_UNARY_PREFIX_DECREMENT]     = PREC_UNARY,
135                 [EXPR_UNARY_CAST]                 = PREC_UNARY,
136                 [EXPR_UNARY_ASSUME]               = PREC_PRIMARY,
137                 [EXPR_UNARY_DELETE]               = PREC_UNARY,
138                 [EXPR_UNARY_DELETE_ARRAY]         = PREC_UNARY,
139                 [EXPR_UNARY_THROW]                = PREC_ASSIGNMENT,
140
141                 [EXPR_BINARY_ADD]                 = PREC_ADDITIVE,
142                 [EXPR_BINARY_SUB]                 = PREC_ADDITIVE,
143                 [EXPR_BINARY_MUL]                 = PREC_MULTIPLICATIVE,
144                 [EXPR_BINARY_DIV]                 = PREC_MULTIPLICATIVE,
145                 [EXPR_BINARY_MOD]                 = PREC_MULTIPLICATIVE,
146                 [EXPR_BINARY_EQUAL]               = PREC_EQUALITY,
147                 [EXPR_BINARY_NOTEQUAL]            = PREC_EQUALITY,
148                 [EXPR_BINARY_LESS]                = PREC_RELATIONAL,
149                 [EXPR_BINARY_LESSEQUAL]           = PREC_RELATIONAL,
150                 [EXPR_BINARY_GREATER]             = PREC_RELATIONAL,
151                 [EXPR_BINARY_GREATEREQUAL]        = PREC_RELATIONAL,
152                 [EXPR_BINARY_BITWISE_AND]         = PREC_AND,
153                 [EXPR_BINARY_BITWISE_OR]          = PREC_OR,
154                 [EXPR_BINARY_BITWISE_XOR]         = PREC_XOR,
155                 [EXPR_BINARY_LOGICAL_AND]         = PREC_LOGICAL_AND,
156                 [EXPR_BINARY_LOGICAL_OR]          = PREC_LOGICAL_OR,
157                 [EXPR_BINARY_SHIFTLEFT]           = PREC_SHIFT,
158                 [EXPR_BINARY_SHIFTRIGHT]          = PREC_SHIFT,
159                 [EXPR_BINARY_ASSIGN]              = PREC_ASSIGNMENT,
160                 [EXPR_BINARY_MUL_ASSIGN]          = PREC_ASSIGNMENT,
161                 [EXPR_BINARY_DIV_ASSIGN]          = PREC_ASSIGNMENT,
162                 [EXPR_BINARY_MOD_ASSIGN]          = PREC_ASSIGNMENT,
163                 [EXPR_BINARY_ADD_ASSIGN]          = PREC_ASSIGNMENT,
164                 [EXPR_BINARY_SUB_ASSIGN]          = PREC_ASSIGNMENT,
165                 [EXPR_BINARY_SHIFTLEFT_ASSIGN]    = PREC_ASSIGNMENT,
166                 [EXPR_BINARY_SHIFTRIGHT_ASSIGN]   = PREC_ASSIGNMENT,
167                 [EXPR_BINARY_BITWISE_AND_ASSIGN]  = PREC_ASSIGNMENT,
168                 [EXPR_BINARY_BITWISE_XOR_ASSIGN]  = PREC_ASSIGNMENT,
169                 [EXPR_BINARY_BITWISE_OR_ASSIGN]   = PREC_ASSIGNMENT,
170                 [EXPR_BINARY_COMMA]               = PREC_EXPRESSION,
171
172                 [EXPR_BINARY_ISGREATER]           = PREC_PRIMARY,
173                 [EXPR_BINARY_ISGREATEREQUAL]      = PREC_PRIMARY,
174                 [EXPR_BINARY_ISLESS]              = PREC_PRIMARY,
175                 [EXPR_BINARY_ISLESSEQUAL]         = PREC_PRIMARY,
176                 [EXPR_BINARY_ISLESSGREATER]       = PREC_PRIMARY,
177                 [EXPR_BINARY_ISUNORDERED]         = PREC_PRIMARY
178         };
179         assert((size_t)kind < lengthof(prec));
180         unsigned res = prec[kind];
181
182         assert(res != PREC_BOTTOM);
183         return res;
184 }
185
186 /**
187  * Print a quoted string constant.
188  *
189  * @param string  the string constant
190  * @param border  the border char
191  */
192 static void print_quoted_string(const string_t *const string, char border)
193 {
194         print_string(get_string_encoding_prefix(string->encoding));
195
196         print_char(border);
197         const char *end = string->begin + string->size;
198         for (const char *c = string->begin; c != end; ++c) {
199                 const char tc = *c;
200                 if (tc == border) {
201                         print_char('\\');
202                 }
203                 switch (tc) {
204                 case '\\': print_string("\\\\"); break;
205                 case '\a': print_string("\\a"); break;
206                 case '\b': print_string("\\b"); break;
207                 case '\f': print_string("\\f"); break;
208                 case '\n': print_string("\\n"); break;
209                 case '\r': print_string("\\r"); break;
210                 case '\t': print_string("\\t"); break;
211                 case '\v': print_string("\\v"); break;
212                 case '\?': print_string("\\?"); break;
213                 case 27:
214                         if (c_mode & _GNUC) {
215                                 print_string("\\e"); break;
216                         }
217                         /* FALLTHROUGH */
218                 default:
219                         if ((unsigned)tc < 0x80 && !isprint(tc)) {
220                                 print_format("\\%03o", (unsigned)tc);
221                         } else {
222                                 print_char(tc);
223                         }
224                         break;
225                 }
226         }
227         print_char(border);
228 }
229
230 static void print_string_literal(string_literal_expression_t const *const literal, char const delimiter)
231 {
232         print_quoted_string(&literal->value, delimiter);
233 }
234
235 static void print_literal(const literal_expression_t *literal)
236 {
237         switch (literal->base.kind) {
238         case EXPR_LITERAL_MS_NOOP:
239                 print_string("__noop");
240                 return;
241
242         case EXPR_LITERAL_BOOLEAN:
243         case EXPR_LITERAL_FLOATINGPOINT:
244         case EXPR_LITERAL_INTEGER:
245                 print_string(literal->value.begin);
246                 return;
247
248         default:
249                 break;
250         }
251         print_string("INVALID LITERAL KIND");
252 }
253
254 /**
255  * Prints a predefined symbol.
256  */
257 static void print_funcname(const funcname_expression_t *funcname)
258 {
259         const char *s = "";
260         switch (funcname->kind) {
261         case FUNCNAME_FUNCTION:        s = (c_mode & _C99) ? "__func__" : "__FUNCTION__"; break;
262         case FUNCNAME_PRETTY_FUNCTION: s = "__PRETTY_FUNCTION__"; break;
263         case FUNCNAME_FUNCSIG:         s = "__FUNCSIG__"; break;
264         case FUNCNAME_FUNCDNAME:       s = "__FUNCDNAME__"; break;
265         }
266         print_string(s);
267 }
268
269 static void print_compound_literal(
270                 const compound_literal_expression_t *expression)
271 {
272         print_char('(');
273         print_type(expression->type);
274         print_char(')');
275         print_initializer(expression->initializer);
276 }
277
278 static void print_assignment_expression(const expression_t *const expr)
279 {
280         print_expression_prec(expr, PREC_ASSIGNMENT);
281 }
282
283 /**
284  * Prints a call expression.
285  *
286  * @param call  the call expression
287  */
288 static void print_call_expression(const call_expression_t *call)
289 {
290         print_expression_prec(call->function, PREC_POSTFIX);
291         print_char('(');
292         separator_t sep = { "", ", " };
293         for (call_argument_t const *arg = call->arguments; arg; arg = arg->next) {
294                 print_string(sep_next(&sep));
295                 print_assignment_expression(arg->expression);
296         }
297         print_char(')');
298 }
299
300 /**
301  * Prints a binary expression.
302  *
303  * @param binexpr   the binary expression
304  */
305 static void print_binary_expression(const binary_expression_t *binexpr)
306 {
307         unsigned prec = get_expression_precedence(binexpr->base.kind);
308         int      r2l  = right_to_left(prec);
309
310         print_expression_prec(binexpr->left, prec + r2l);
311         char const* op;
312         switch (binexpr->base.kind) {
313         case EXPR_BINARY_COMMA:              op = ", ";    break;
314         case EXPR_BINARY_ASSIGN:             op = " = ";   break;
315         case EXPR_BINARY_ADD:                op = " + ";   break;
316         case EXPR_BINARY_SUB:                op = " - ";   break;
317         case EXPR_BINARY_MUL:                op = " * ";   break;
318         case EXPR_BINARY_MOD:                op = " % ";   break;
319         case EXPR_BINARY_DIV:                op = " / ";   break;
320         case EXPR_BINARY_BITWISE_OR:         op = " | ";   break;
321         case EXPR_BINARY_BITWISE_AND:        op = " & ";   break;
322         case EXPR_BINARY_BITWISE_XOR:        op = " ^ ";   break;
323         case EXPR_BINARY_LOGICAL_OR:         op = " || ";  break;
324         case EXPR_BINARY_LOGICAL_AND:        op = " && ";  break;
325         case EXPR_BINARY_NOTEQUAL:           op = " != ";  break;
326         case EXPR_BINARY_EQUAL:              op = " == ";  break;
327         case EXPR_BINARY_LESS:               op = " < ";   break;
328         case EXPR_BINARY_LESSEQUAL:          op = " <= ";  break;
329         case EXPR_BINARY_GREATER:            op = " > ";   break;
330         case EXPR_BINARY_GREATEREQUAL:       op = " >= ";  break;
331         case EXPR_BINARY_SHIFTLEFT:          op = " << ";  break;
332         case EXPR_BINARY_SHIFTRIGHT:         op = " >> ";  break;
333
334         case EXPR_BINARY_ADD_ASSIGN:         op = " += ";  break;
335         case EXPR_BINARY_SUB_ASSIGN:         op = " -= ";  break;
336         case EXPR_BINARY_MUL_ASSIGN:         op = " *= ";  break;
337         case EXPR_BINARY_MOD_ASSIGN:         op = " %= ";  break;
338         case EXPR_BINARY_DIV_ASSIGN:         op = " /= ";  break;
339         case EXPR_BINARY_BITWISE_OR_ASSIGN:  op = " |= ";  break;
340         case EXPR_BINARY_BITWISE_AND_ASSIGN: op = " &= ";  break;
341         case EXPR_BINARY_BITWISE_XOR_ASSIGN: op = " ^= ";  break;
342         case EXPR_BINARY_SHIFTLEFT_ASSIGN:   op = " <<= "; break;
343         case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  op = " >>= "; break;
344         default: panic("invalid binexpression found");
345         }
346         print_string(op);
347         print_expression_prec(binexpr->right, prec + 1 - r2l);
348 }
349
350 /**
351  * Prints an unary expression.
352  *
353  * @param unexpr   the unary expression
354  */
355 static void print_unary_expression(const unary_expression_t *unexpr)
356 {
357         unsigned prec = get_expression_precedence(unexpr->base.kind);
358         switch (unexpr->base.kind) {
359         case EXPR_UNARY_NEGATE:           print_char  ('-' ); break;
360         case EXPR_UNARY_PLUS:             print_char  ('+' ); break;
361         case EXPR_UNARY_NOT:              print_char  ('!' ); break;
362         case EXPR_UNARY_BITWISE_NEGATE:   print_char  ('~' ); break;
363         case EXPR_UNARY_PREFIX_INCREMENT: print_string("++"); break;
364         case EXPR_UNARY_PREFIX_DECREMENT: print_string("--"); break;
365         case EXPR_UNARY_DEREFERENCE:      print_char  ('*' ); break;
366         case EXPR_UNARY_TAKE_ADDRESS:     print_char  ('&' ); break;
367         case EXPR_UNARY_DELETE:           print_string("delete "); break;
368         case EXPR_UNARY_DELETE_ARRAY:     print_string("delete [] "); break;
369
370         case EXPR_UNARY_POSTFIX_INCREMENT:
371                 print_expression_prec(unexpr->value, prec);
372                 print_string("++");
373                 return;
374         case EXPR_UNARY_POSTFIX_DECREMENT:
375                 print_expression_prec(unexpr->value, prec);
376                 print_string("--");
377                 return;
378         case EXPR_UNARY_CAST:
379                 print_char('(');
380                 print_type(unexpr->base.type);
381                 print_char(')');
382                 break;
383         case EXPR_UNARY_ASSUME:
384                 print_string("__assume(");
385                 print_assignment_expression(unexpr->value);
386                 print_char(')');
387                 return;
388
389         case EXPR_UNARY_THROW:
390                 if (unexpr->value == NULL) {
391                         print_string("throw");
392                         return;
393                 }
394                 print_string("throw ");
395                 break;
396
397         default:
398                 panic("invalid unary expression found");
399         }
400         print_expression_prec(unexpr->value, prec);
401 }
402
403 /**
404  * Prints a reference expression.
405  *
406  * @param ref   the reference expression
407  */
408 static void print_reference_expression(const reference_expression_t *ref)
409 {
410         print_string(ref->entity->base.symbol->string);
411 }
412
413 /**
414  * Prints a label address expression.
415  *
416  * @param ref   the reference expression
417  */
418 static void print_label_address_expression(const label_address_expression_t *le)
419 {
420         print_format("&&%s", le->label->base.symbol->string);
421 }
422
423 /**
424  * Prints an array expression.
425  *
426  * @param expression   the array expression
427  */
428 static void print_array_expression(const array_access_expression_t *expression)
429 {
430         if (!expression->flipped) {
431                 print_expression_prec(expression->array_ref, PREC_POSTFIX);
432                 print_char('[');
433                 print_expression(expression->index);
434                 print_char(']');
435         } else {
436                 print_expression_prec(expression->index, PREC_POSTFIX);
437                 print_char('[');
438                 print_expression(expression->array_ref);
439                 print_char(']');
440         }
441 }
442
443 /**
444  * Prints a typeproperty expression (sizeof or __alignof__).
445  *
446  * @param expression   the type property expression
447  */
448 static void print_typeprop_expression(const typeprop_expression_t *expression)
449 {
450         switch (expression->base.kind) {
451         case EXPR_SIZEOF:  print_string("sizeof");                                   break;
452         case EXPR_ALIGNOF: print_string(c_mode & _C11 ? "_Alignof" : "__alignof__"); break;
453         default:           panic("invalid typeprop kind");
454         }
455         if (expression->tp_expression != NULL) {
456                 /* PREC_TOP: always print the '()' here, sizeof x is right but unusual */
457                 print_expression_prec(expression->tp_expression, PREC_TOP);
458         } else {
459                 print_char('(');
460                 print_type(expression->type);
461                 print_char(')');
462         }
463 }
464
465 /**
466  * Prints a builtin constant expression.
467  *
468  * @param expression   the builtin constant expression
469  */
470 static void print_builtin_constant(const builtin_constant_expression_t *expression)
471 {
472         print_string("__builtin_constant_p(");
473         print_assignment_expression(expression->value);
474         print_char(')');
475 }
476
477 /**
478  * Prints a builtin types compatible expression.
479  *
480  * @param expression   the builtin types compatible expression
481  */
482 static void print_builtin_types_compatible(
483                 const builtin_types_compatible_expression_t *expression)
484 {
485         print_string("__builtin_types_compatible_p(");
486         print_type(expression->left);
487         print_string(", ");
488         print_type(expression->right);
489         print_char(')');
490 }
491
492 /**
493  * Prints a conditional expression.
494  *
495  * @param expression   the conditional expression
496  */
497 static void print_conditional(const conditional_expression_t *expression)
498 {
499         print_expression_prec(expression->condition, PREC_LOGICAL_OR);
500         if (expression->true_expression != NULL) {
501                 print_string(" ? ");
502                 print_expression_prec(expression->true_expression, PREC_EXPRESSION);
503                 print_string(" : ");
504         } else {
505                 print_string(" ?: ");
506         }
507         precedence_t prec = c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL;
508         print_expression_prec(expression->false_expression, prec);
509 }
510
511 /**
512  * Prints a va_start expression.
513  *
514  * @param expression   the va_start expression
515  */
516 static void print_va_start(const va_start_expression_t *const expression)
517 {
518         print_string("__builtin_va_start(");
519         print_assignment_expression(expression->ap);
520         print_string(", ");
521         print_assignment_expression(expression->parameter);
522         print_char(')');
523 }
524
525 /**
526  * Prints a va_arg expression.
527  *
528  * @param expression   the va_arg expression
529  */
530 static void print_va_arg(const va_arg_expression_t *expression)
531 {
532         print_string("__builtin_va_arg(");
533         print_assignment_expression(expression->ap);
534         print_string(", ");
535         print_type(expression->base.type);
536         print_char(')');
537 }
538
539 /**
540  * Prints a va_copy expression.
541  *
542  * @param expression   the va_copy expression
543  */
544 static void print_va_copy(const va_copy_expression_t *expression)
545 {
546         print_string("__builtin_va_copy(");
547         print_assignment_expression(expression->dst);
548         print_string(", ");
549         print_assignment_expression(expression->src);
550         print_char(')');
551 }
552
553 /**
554  * Prints a select expression (. or ->).
555  *
556  * @param expression   the select expression
557  */
558 static void print_select(const select_expression_t *expression)
559 {
560         print_expression_prec(expression->compound, PREC_POSTFIX);
561         /* do not print anything for anonymous struct/union selects
562          * FIXME: if the anonymous select was a '->' this will print '.'
563          */
564         if (expression->compound_entry->base.symbol == NULL)
565                 return;
566
567         if (is_type_pointer(skip_typeref(expression->compound->base.type))) {
568                 print_string("->");
569         } else {
570                 print_char('.');
571         }
572         print_string(expression->compound_entry->base.symbol->string);
573 }
574
575 /**
576  * Prints a type classify expression.
577  *
578  * @param expr   the type classify expression
579  */
580 static void print_classify_type_expression(
581         const classify_type_expression_t *const expr)
582 {
583         print_string("__builtin_classify_type(");
584         print_assignment_expression(expr->type_expression);
585         print_char(')');
586 }
587
588 /**
589  * Prints a designator.
590  *
591  * @param designator  the designator
592  */
593 static void print_designator(const designator_t *designator)
594 {
595         for ( ; designator != NULL; designator = designator->next) {
596                 if (designator->symbol == NULL) {
597                         print_char('[');
598                         print_expression(designator->array_index);
599                         print_char(']');
600                 } else {
601                         print_char('.');
602                         print_string(designator->symbol->string);
603                 }
604         }
605 }
606
607 /**
608  * Prints an offsetof expression.
609  *
610  * @param expression   the offset expression
611  */
612 static void print_offsetof_expression(const offsetof_expression_t *expression)
613 {
614         print_string("__builtin_offsetof(");
615         print_type(expression->type);
616         print_char(',');
617         print_designator(expression->designator);
618         print_char(')');
619 }
620
621 /**
622  * Prints a statement expression.
623  *
624  * @param expression   the statement expression
625  */
626 static void print_statement_expression(const statement_expression_t *expression)
627 {
628         print_char('(');
629         print_statement(expression->statement);
630         print_char(')');
631 }
632
633 static bool needs_parentheses(expression_t const *const expr, unsigned const top_prec)
634 {
635         if (expr->base.parenthesized)
636                 return true;
637
638         if (top_prec > get_expression_precedence(expr->base.kind))
639                 return true;
640
641         if (print_parenthesis && top_prec != PREC_BOTTOM) {
642                 switch (expr->kind) {
643                 case EXPR_ENUM_CONSTANT:
644                 case EXPR_FUNCNAME:
645                 case EXPR_LITERAL_CASES:
646                 case EXPR_LITERAL_CHARACTER:
647                 case EXPR_REFERENCE:
648                 case EXPR_STRING_LITERAL:
649                         /* Do not print () around subexpressions consisting of a single token. */
650                         return false;
651
652                 default:
653                         return true;
654                 }
655         }
656
657         return false;
658 }
659
660 /**
661  * Prints an expression with parenthesis if needed.
662  *
663  * @param expression  the expression to print
664  * @param top_prec    the precedence of the user of this expression.
665  */
666 static void print_expression_prec(expression_t const *expr, unsigned const top_prec)
667 {
668         if (expr->kind == EXPR_UNARY_CAST && expr->base.implicit && !print_implicit_casts) {
669                 expr = expr->unary.value;
670         }
671
672         bool const parenthesized = needs_parentheses(expr, top_prec);
673
674         if (parenthesized)
675                 print_char('(');
676         switch (expr->kind) {
677         case EXPR_ALIGNOF:
678         case EXPR_SIZEOF:                     print_typeprop_expression(     &expr->typeprop);                 break;
679         case EXPR_ARRAY_ACCESS:               print_array_expression(        &expr->array_access);             break;
680         case EXPR_BINARY_CASES:               print_binary_expression(       &expr->binary);                   break;
681         case EXPR_BUILTIN_CONSTANT_P:         print_builtin_constant(        &expr->builtin_constant);         break;
682         case EXPR_BUILTIN_TYPES_COMPATIBLE_P: print_builtin_types_compatible(&expr->builtin_types_compatible); break;
683         case EXPR_CALL:                       print_call_expression(         &expr->call);                     break;
684         case EXPR_CLASSIFY_TYPE:              print_classify_type_expression(&expr->classify_type);            break;
685         case EXPR_COMPOUND_LITERAL:           print_compound_literal(        &expr->compound_literal);         break;
686         case EXPR_CONDITIONAL:                print_conditional(             &expr->conditional);              break;
687         case EXPR_ERROR:                      print_string("$error$");                                         break;
688         case EXPR_FUNCNAME:                   print_funcname(                &expr->funcname);                 break;
689         case EXPR_LABEL_ADDRESS:              print_label_address_expression(&expr->label_address);            break;
690         case EXPR_LITERAL_CASES:              print_literal(                 &expr->literal);                  break;
691         case EXPR_LITERAL_CHARACTER:          print_string_literal(          &expr->string_literal, '\'');     break;
692         case EXPR_OFFSETOF:                   print_offsetof_expression(     &expr->offsetofe);                break;
693         case EXPR_REFERENCE:
694         case EXPR_ENUM_CONSTANT:              print_reference_expression(    &expr->reference);                break;
695         case EXPR_SELECT:                     print_select(                  &expr->select);                   break;
696         case EXPR_STATEMENT:                  print_statement_expression(    &expr->statement);                break;
697         case EXPR_STRING_LITERAL:             print_string_literal(          &expr->string_literal, '"');      break;
698         case EXPR_UNARY_CASES:                print_unary_expression(        &expr->unary);                    break;
699         case EXPR_VA_ARG:                     print_va_arg(                  &expr->va_arge);                  break;
700         case EXPR_VA_COPY:                    print_va_copy(                 &expr->va_copye);                 break;
701         case EXPR_VA_START:                   print_va_start(                &expr->va_starte);                break;
702         }
703         if (parenthesized)
704                 print_char(')');
705 }
706
707 static void print_indented_statement(statement_t const *const stmt)
708 {
709         switch (stmt->kind) {
710         case STATEMENT_LABEL:
711                 break;
712
713         case STATEMENT_CASE_LABEL:
714                 for (int i = 0; i != case_indent; ++i)
715                         print_char('\t');
716                 break;
717
718         default:
719                 print_indent();
720                 break;
721         }
722         print_statement(stmt);
723 }
724
725 /**
726  * Print an compound statement.
727  *
728  * @param block  the compound statement
729  */
730 static void print_compound_statement(const compound_statement_t *block)
731 {
732         print_string("{\n");
733         ++indent;
734
735         for (statement_t const *stmt = block->statements; stmt; stmt = stmt->base.next) {
736                 print_indented_statement(stmt);
737                 print_char('\n');
738         }
739
740         --indent;
741         print_indent();
742         print_char('}');
743 }
744
745 /**
746  * Print a return statement.
747  *
748  * @param statement  the return statement
749  */
750 static void print_return_statement(const return_statement_t *statement)
751 {
752         expression_t const *const val = statement->value;
753         if (val != NULL) {
754                 print_string("return ");
755                 print_expression(val);
756                 print_char(';');
757         } else {
758                 print_string("return;");
759         }
760 }
761
762 /**
763  * Print an expression statement.
764  *
765  * @param statement  the expression statement
766  */
767 static void print_expression_statement(const expression_statement_t *statement)
768 {
769         print_expression(statement->expression);
770         print_char(';');
771 }
772
773 /**
774  * Print a computed goto statement.
775  *
776  * @param statement  the computed goto statement
777  */
778 static void print_computed_goto_statement(computed_goto_statement_t const *const stmt)
779 {
780         print_string("goto *");
781         print_expression(stmt->expression);
782         print_char(';');
783 }
784
785 /**
786  * Print a goto statement.
787  *
788  * @param statement  the goto statement
789  */
790 static void print_goto_statement(const goto_statement_t *statement)
791 {
792         print_string("goto ");
793         print_string(statement->label->base.symbol->string);
794         print_char(';');
795 }
796
797 /**
798  * Print a label statement.
799  *
800  * @param statement  the label statement
801  */
802 static void print_label_statement(const label_statement_t *statement)
803 {
804         print_format("%s:\n", statement->label->base.symbol->string);
805         print_indented_statement(statement->statement);
806 }
807
808 static void print_inner_statement(statement_t const *const stmt)
809 {
810         if (stmt->kind == STATEMENT_COMPOUND) {
811                 print_char(' ');
812                 print_compound_statement(&stmt->compound);
813         } else {
814                 print_char('\n');
815                 ++indent;
816                 print_indented_statement(stmt);
817                 --indent;
818         }
819 }
820
821 static void print_after_inner_statement(statement_t const *const stmt)
822 {
823         if (stmt->kind == STATEMENT_COMPOUND) {
824                 print_char(' ');
825         } else {
826                 print_char('\n');
827                 print_indent();
828         }
829 }
830
831 /**
832  * Print an if statement.
833  *
834  * @param statement  the if statement
835  */
836 static void print_if_statement(const if_statement_t *statement)
837 {
838         print_string("if (");
839         print_expression(statement->condition);
840         print_char(')');
841         print_inner_statement(statement->true_statement);
842
843         statement_t const *const f = statement->false_statement;
844         if (f) {
845                 print_after_inner_statement(statement->true_statement);
846                 print_string("else");
847                 if (f->kind == STATEMENT_IF) {
848                         print_char(' ');
849                         print_if_statement(&f->ifs);
850                 } else {
851                         print_inner_statement(f);
852                 }
853         }
854 }
855
856 /**
857  * Print a switch statement.
858  *
859  * @param statement  the switch statement
860  */
861 static void print_switch_statement(const switch_statement_t *statement)
862 {
863         int const old_case_indent = case_indent;
864         case_indent = indent;
865
866         print_string("switch (");
867         print_expression(statement->expression);
868         print_char(')');
869         print_inner_statement(statement->body);
870
871         case_indent = old_case_indent;
872 }
873
874 /**
875  * Print a case label (including the default label).
876  *
877  * @param statement  the case label statement
878  */
879 static void print_case_label(const case_label_statement_t *statement)
880 {
881         if (statement->expression == NULL) {
882                 print_string("default:\n");
883         } else {
884                 print_string("case ");
885                 print_expression(statement->expression);
886                 if (statement->end_range != NULL) {
887                         print_string(" ... ");
888                         print_expression(statement->end_range);
889                 }
890                 print_string(":\n");
891         }
892         print_indented_statement(statement->statement);
893 }
894
895 static void print_typedef(const entity_t *entity)
896 {
897         print_string("typedef ");
898         print_type_ext(entity->typedefe.type, entity->base.symbol, NULL);
899         print_char(';');
900 }
901
902 /**
903  * returns true if the entity is a compiler generated one and has no real
904  * correspondenc in the source file
905  */
906 static bool is_generated_entity(const entity_t *entity)
907 {
908         if (entity->kind == ENTITY_TYPEDEF)
909                 return entity->typedefe.builtin;
910
911         if (is_declaration(entity))
912                 return entity->declaration.implicit;
913
914         return false;
915 }
916
917 /**
918  * Print a declaration statement.
919  *
920  * @param statement   the statement
921  */
922 static void print_declaration_statement(
923                 const declaration_statement_t *statement)
924 {
925         bool first = true;
926         entity_t *entity = statement->declarations_begin;
927         if (entity == NULL) {
928                 print_string("/* empty declaration statement */");
929                 return;
930         }
931
932         entity_t *const end = statement->declarations_end->base.next;
933         for (; entity != end; entity = entity->base.next) {
934                 if (entity->kind == ENTITY_ENUM_VALUE)
935                         continue;
936                 if (is_generated_entity(entity))
937                         continue;
938
939                 if (!first) {
940                         print_char('\n');
941                         print_indent();
942                 } else {
943                         first = false;
944                 }
945
946                 print_entity(entity);
947         }
948 }
949
950 /**
951  * Print a do-while statement.
952  *
953  * @param statement   the statement
954  */
955 static void print_do_while_statement(const do_while_statement_t *statement)
956 {
957         print_string("do");
958         print_inner_statement(statement->body);
959         print_after_inner_statement(statement->body);
960         print_string("while (");
961         print_expression(statement->condition);
962         print_string(");");
963 }
964
965 /**
966  * Print a for statement.
967  *
968  * @param statement   the statement
969  */
970 static void print_for_statement(const for_statement_t *statement)
971 {
972         if (statement->initialisation || statement->scope.entities || !statement->condition || statement->step) {
973                 print_string("for (");
974                 if (statement->initialisation != NULL) {
975                         print_expression(statement->initialisation);
976                         print_char(';');
977                 } else {
978                         entity_t const *entity = statement->scope.entities;
979                         for (; entity != NULL; entity = entity->base.next) {
980                                 if (is_generated_entity(entity))
981                                         continue;
982                                 /* FIXME display of multiple declarations is wrong */
983                                 print_declaration(entity);
984                         }
985                 }
986                 if (statement->condition != NULL) {
987                         print_char(' ');
988                         print_expression(statement->condition);
989                 }
990                 print_char(';');
991                 if (statement->step != NULL) {
992                         print_char(' ');
993                         print_expression(statement->step);
994                 }
995         } else {
996                 print_string("while (");
997                 print_expression(statement->condition);
998         }
999         print_char(')');
1000         print_inner_statement(statement->body);
1001 }
1002
1003 /**
1004  * Print assembler arguments.
1005  *
1006  * @param arguments   the arguments
1007  */
1008 static void print_asm_arguments(asm_argument_t const *const arguments)
1009 {
1010         print_string(" :");
1011         separator_t sep = { " ", ", " };
1012         for (asm_argument_t const *i = arguments; i; i = i->next) {
1013                 print_string(sep_next(&sep));
1014                 if (i->symbol)
1015                         print_format("[%s] ", i->symbol->string);
1016                 print_quoted_string(&i->constraints, '"');
1017                 print_string(" (");
1018                 print_expression(i->expression);
1019                 print_char(')');
1020         }
1021 }
1022
1023 /**
1024  * Print assembler clobbers.
1025  *
1026  * @param clobbers   the clobbers
1027  */
1028 static void print_asm_clobbers(asm_clobber_t const *const clobbers)
1029 {
1030         print_string(" :");
1031         separator_t sep = { " ", ", " };
1032         for (asm_clobber_t const *i = clobbers; i; i = i->next) {
1033                 print_string(sep_next(&sep));
1034                 print_quoted_string(&i->clobber, '"');
1035         }
1036 }
1037
1038 static void print_asm_labels(asm_label_t const *const labels)
1039 {
1040         print_string(" :");
1041         separator_t sep = { " ", ", " };
1042         for (asm_label_t const *i = labels; i; i = i->next) {
1043                 print_string(sep_next(&sep));
1044                 print_string(i->label->base.symbol->string);
1045         }
1046 }
1047
1048 /**
1049  * Print an assembler statement.
1050  *
1051  * @param stmt   the statement
1052  */
1053 static void print_asm_statement(asm_statement_t const *const stmt)
1054 {
1055         print_string("asm");
1056         if (stmt->is_volatile) print_string(" volatile");
1057         if (stmt->labels)      print_string(" goto");
1058         print_char('(');
1059         print_quoted_string(&stmt->asm_text, '"');
1060
1061         unsigned const n =
1062                 stmt->labels   ? 4 :
1063                 stmt->clobbers ? 3 :
1064                 stmt->inputs   ? 2 :
1065                 stmt->outputs  ? 1 :
1066                 0;
1067         if (n >= 1) print_asm_arguments(stmt->outputs);
1068         if (n >= 2) print_asm_arguments(stmt->inputs);
1069         if (n >= 3) print_asm_clobbers( stmt->clobbers);
1070         if (n >= 4) print_asm_labels(   stmt->labels);
1071
1072         print_string(");");
1073 }
1074
1075 /**
1076  * Print a microsoft __try statement.
1077  *
1078  * @param statement   the statement
1079  */
1080 static void print_ms_try_statement(const ms_try_statement_t *statement)
1081 {
1082         print_string("__try");
1083         print_inner_statement(statement->try_statement);
1084         print_after_inner_statement(statement->try_statement);
1085         if (statement->except_expression != NULL) {
1086                 print_string("__except(");
1087                 print_expression(statement->except_expression);
1088                 print_char(')');
1089         } else {
1090                 print_string("__finally");
1091         }
1092         print_inner_statement(statement->final_statement);
1093 }
1094
1095 /**
1096  * Print a microsoft __leave statement.
1097  *
1098  * @param statement   the statement
1099  */
1100 static void print_leave_statement(const leave_statement_t *statement)
1101 {
1102         (void)statement;
1103         print_string("__leave;");
1104 }
1105
1106 /**
1107  * Print a statement.
1108  *
1109  * @param statement   the statement
1110  */
1111 void print_statement(statement_t const *const stmt)
1112 {
1113         switch (stmt->kind) {
1114         case STATEMENT_ASM:           print_asm_statement(          &stmt->asms);          break;
1115         case STATEMENT_BREAK:         print_string("break;");                              break;
1116         case STATEMENT_CASE_LABEL:    print_case_label(             &stmt->case_label);    break;
1117         case STATEMENT_COMPOUND:      print_compound_statement(     &stmt->compound);      break;
1118         case STATEMENT_COMPUTED_GOTO: print_computed_goto_statement(&stmt->computed_goto); break;
1119         case STATEMENT_CONTINUE:      print_string("continue;");                           break;
1120         case STATEMENT_DECLARATION:   print_declaration_statement(  &stmt->declaration);   break;
1121         case STATEMENT_DO_WHILE:      print_do_while_statement(     &stmt->do_while);      break;
1122         case STATEMENT_EMPTY:         print_char(';');                                     break;
1123         case STATEMENT_ERROR:         print_string("$error statement$");                   break;
1124         case STATEMENT_EXPRESSION:    print_expression_statement(   &stmt->expression);    break;
1125         case STATEMENT_FOR:           print_for_statement(          &stmt->fors);          break;
1126         case STATEMENT_GOTO:          print_goto_statement(         &stmt->gotos);         break;
1127         case STATEMENT_IF:            print_if_statement(           &stmt->ifs);           break;
1128         case STATEMENT_LABEL:         print_label_statement(        &stmt->label);         break;
1129         case STATEMENT_LEAVE:         print_leave_statement(        &stmt->leave);         break;
1130         case STATEMENT_MS_TRY:        print_ms_try_statement(       &stmt->ms_try);        break;
1131         case STATEMENT_RETURN:        print_return_statement(       &stmt->returns);       break;
1132         case STATEMENT_SWITCH:        print_switch_statement(       &stmt->switchs);       break;
1133         }
1134 }
1135
1136 /**
1137  * Print a storage class.
1138  *
1139  * @param storage_class   the storage class
1140  */
1141 static void print_storage_class(storage_class_tag_t storage_class)
1142 {
1143         switch (storage_class) {
1144         case STORAGE_CLASS_NONE:     return;
1145         case STORAGE_CLASS_TYPEDEF:  print_string("typedef ");  return;
1146         case STORAGE_CLASS_EXTERN:   print_string("extern ");   return;
1147         case STORAGE_CLASS_STATIC:   print_string("static ");   return;
1148         case STORAGE_CLASS_AUTO:     print_string("auto ");     return;
1149         case STORAGE_CLASS_REGISTER: print_string("register "); return;
1150         }
1151         panic("invalid storage class");
1152 }
1153
1154 /**
1155  * Print an initializer.
1156  *
1157  * @param initializer  the initializer
1158  */
1159 void print_initializer(const initializer_t *initializer)
1160 {
1161         if (initializer == NULL) {
1162                 print_string("{}");
1163                 return;
1164         }
1165
1166         switch (initializer->kind) {
1167         case INITIALIZER_STRING:
1168         case INITIALIZER_VALUE:
1169                 print_assignment_expression(initializer->value.value);
1170                 return;
1171
1172         case INITIALIZER_LIST: {
1173                 print_string("{ ");
1174                 const initializer_list_t *list = &initializer->list;
1175
1176                 for (size_t i = 0 ; i < list->len; ++i) {
1177                         const initializer_t *sub_init = list->initializers[i];
1178                         print_initializer(list->initializers[i]);
1179                         if (i < list->len-1) {
1180                                 if (sub_init == NULL || sub_init->kind != INITIALIZER_DESIGNATOR)
1181                                         print_string(", ");
1182                         }
1183                 }
1184                 print_string(" }");
1185                 return;
1186         }
1187
1188         case INITIALIZER_DESIGNATOR:
1189                 print_designator(initializer->designator.designator);
1190                 print_string(" = ");
1191                 return;
1192         }
1193
1194         panic("invalid initializer kind found");
1195 }
1196
1197 #if 0
1198 /**
1199  * Print microsoft extended declaration modifiers.
1200  */
1201 static void print_ms_modifiers(const declaration_t *declaration)
1202 {
1203         if ((c_mode & _MS) == 0)
1204                 return;
1205
1206         decl_modifiers_t modifiers = declaration->modifiers;
1207
1208         separator_t sep = { "__declspec(", ", " };
1209
1210         if (declaration->base.kind == ENTITY_VARIABLE) {
1211                 variable_t *variable = (variable_t*)declaration;
1212                 if (variable->alignment != 0
1213                                 || variable->get_property_sym != NULL
1214                                 || variable->put_property_sym != NULL) {
1215                         if (variable->alignment != 0) {
1216                                 print_format("%salign(%u)", sep_next(&sep), variable->alignment);
1217                         }
1218                         if (variable->get_property_sym != NULL
1219                                         || variable->put_property_sym != NULL) {
1220                                 char *comma = "";
1221                                 print_format("%sproperty(", sep_next(&sep));
1222                                 if (variable->get_property_sym != NULL) {
1223                                         print_format("get=%s", variable->get_property_sym->string);
1224                                         comma = ", ";
1225                                 }
1226                                 if (variable->put_property_sym != NULL)
1227                                         print_format("%sput=%s", comma, variable->put_property_sym->string);
1228                                 print_char(')');
1229                         }
1230                 }
1231         }
1232
1233         /* DM_FORCEINLINE handled outside. */
1234         if ((modifiers & ~DM_FORCEINLINE) != 0) {
1235                 if (modifiers & DM_DLLIMPORT) {
1236                         print_format("%sdllimport", sep_next(&sep));
1237                 }
1238                 if (modifiers & DM_DLLEXPORT) {
1239                         print_format("%sdllexport", sep_next(&sep));
1240                 }
1241                 if (modifiers & DM_THREAD) {
1242                         print_format("%sthread", sep_next(&sep));
1243                 }
1244                 if (modifiers & DM_NAKED) {
1245                         print_format("%snaked", sep_next(&sep));
1246                 }
1247                 if (modifiers & DM_THREAD) {
1248                         print_format("%sthread", sep_next(&sep));
1249                 }
1250                 if (modifiers & DM_SELECTANY) {
1251                         print_format("%sselectany", sep_next(&sep));
1252                 }
1253                 if (modifiers & DM_NOTHROW) {
1254                         print_format("%snothrow", sep_next(&sep));
1255                 }
1256                 if (modifiers & DM_NORETURN) {
1257                         print_format("%snoreturn", sep_next(&sep));
1258                 }
1259                 if (modifiers & DM_NOINLINE) {
1260                         print_format("%snoinline", sep_next(&sep));
1261                 }
1262                 if (modifiers & DM_DEPRECATED) {
1263                         print_format("%sdeprecated", sep_next(&sep));
1264                         if (declaration->deprecated_string != NULL)
1265                                 print_format("(\"%s\")",
1266                                         declaration->deprecated_string);
1267                 }
1268                 if (modifiers & DM_RESTRICT) {
1269                         print_format("%srestrict", sep_next(&sep));
1270                 }
1271                 if (modifiers & DM_NOALIAS) {
1272                         print_format("%snoalias", sep_next(&sep));
1273                 }
1274         }
1275
1276         if (!sep_at_first(&sep))
1277                 print_string(") ");
1278 }
1279 #endif
1280
1281 static void print_scope(const scope_t *scope)
1282 {
1283         const entity_t *entity = scope->entities;
1284         for ( ; entity != NULL; entity = entity->base.next) {
1285                 print_indent();
1286                 print_entity(entity);
1287                 print_char('\n');
1288         }
1289 }
1290
1291 static void print_namespace(const namespace_t *namespace)
1292 {
1293         print_string("namespace ");
1294         if (namespace->base.symbol != NULL) {
1295                 print_string(namespace->base.symbol->string);
1296                 print_char(' ');
1297         }
1298
1299         print_string("{\n");
1300         ++indent;
1301
1302         print_scope(&namespace->members);
1303
1304         --indent;
1305         print_indent();
1306         print_string("}\n");
1307 }
1308
1309 /**
1310  * Print a variable or function declaration
1311  */
1312 void print_declaration(const entity_t *entity)
1313 {
1314         assert(is_declaration(entity));
1315         const declaration_t *declaration = &entity->declaration;
1316
1317         print_storage_class((storage_class_tag_t)declaration->declared_storage_class);
1318         if (entity->kind == ENTITY_FUNCTION) {
1319                 function_t *function = (function_t*)declaration;
1320                 if (function->is_inline) {
1321                         if (declaration->modifiers & DM_FORCEINLINE) {
1322                                 print_string("__forceinline ");
1323                         } else if (declaration->modifiers & DM_MICROSOFT_INLINE) {
1324                                 print_string("__inline ");
1325                         } else {
1326                                 print_string("inline ");
1327                         }
1328                 }
1329         }
1330         //print_ms_modifiers(declaration);
1331         switch (entity->kind) {
1332                 case ENTITY_FUNCTION:
1333                         print_type_ext(entity->declaration.type, entity->base.symbol,
1334                                         &entity->function.parameters);
1335
1336                         if (entity->function.body != NULL) {
1337                                 print_char('\n');
1338                                 print_indented_statement(entity->function.body);
1339                                 print_char('\n');
1340                                 return;
1341                         }
1342                         break;
1343
1344                 case ENTITY_VARIABLE:
1345                         if (entity->variable.thread_local)
1346                                 print_string(c_mode & _C11 ? "_Thread_local " : "__thread ");
1347                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1348                         if (entity->variable.initializer != NULL) {
1349                                 print_string(" = ");
1350                                 print_initializer(entity->variable.initializer);
1351                         }
1352                         break;
1353
1354                 case ENTITY_COMPOUND_MEMBER:
1355                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1356                         if (entity->compound_member.bitfield) {
1357                                 print_format(" : %u", entity->compound_member.bit_size);
1358                         }
1359                         break;
1360
1361                 default:
1362                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1363                         break;
1364         }
1365         print_char(';');
1366 }
1367
1368 /**
1369  * Prints an expression.
1370  *
1371  * @param expression  the expression
1372  */
1373 void print_expression(const expression_t *expression)
1374 {
1375         print_expression_prec(expression, PREC_BOTTOM);
1376 }
1377
1378 /**
1379  * Print a declaration.
1380  *
1381  * @param declaration  the declaration
1382  */
1383 void print_entity(const entity_t *entity)
1384 {
1385         if (entity->base.namespc != NAMESPACE_NORMAL && entity->base.symbol == NULL)
1386                 return;
1387
1388         switch ((entity_kind_tag_t)entity->kind) {
1389         case ENTITY_VARIABLE:
1390         case ENTITY_PARAMETER:
1391         case ENTITY_COMPOUND_MEMBER:
1392         case ENTITY_FUNCTION:
1393                 print_declaration(entity);
1394                 return;
1395         case ENTITY_TYPEDEF:
1396                 print_typedef(entity);
1397                 return;
1398         case ENTITY_CLASS:
1399                 /* TODO */
1400                 print_string("class ");
1401                 print_string(entity->base.symbol->string);
1402                 print_string("; /* TODO */\n");
1403                 return;
1404         case ENTITY_STRUCT:
1405                 print_string("struct ");
1406                 goto print_compound;
1407         case ENTITY_UNION:
1408                 print_string("union ");
1409 print_compound:
1410                 print_string(entity->base.symbol->string);
1411                 if (entity->compound.complete) {
1412                         print_char(' ');
1413                         print_compound_definition(&entity->compound);
1414                 }
1415                 print_char(';');
1416                 return;
1417         case ENTITY_ENUM:
1418                 print_string("enum ");
1419                 print_string(entity->base.symbol->string);
1420                 print_char(' ');
1421                 print_enum_definition(&entity->enume);
1422                 print_char(';');
1423                 return;
1424         case ENTITY_NAMESPACE:
1425                 print_namespace(&entity->namespacee);
1426                 return;
1427         case ENTITY_LOCAL_LABEL:
1428                 print_string("__label__ ");
1429                 print_string(entity->base.symbol->string);
1430                 print_char(';');
1431                 return;
1432         case ENTITY_LABEL:
1433         case ENTITY_ENUM_VALUE:
1434                 panic("print_entity used on unexpected entity type");
1435         }
1436         panic("Invalid entity type encountered");
1437 }
1438
1439 /**
1440  * Print the AST of a translation unit.
1441  *
1442  * @param unit   the translation unit
1443  */
1444 void print_ast(const translation_unit_t *unit)
1445 {
1446         entity_t *entity = unit->scope.entities;
1447         for ( ; entity != NULL; entity = entity->base.next) {
1448                 if (entity->kind == ENTITY_ENUM_VALUE)
1449                         continue;
1450                 if (entity->base.namespc != NAMESPACE_NORMAL
1451                                 && entity->base.symbol == NULL)
1452                         continue;
1453                 if (is_generated_entity(entity))
1454                         continue;
1455
1456                 print_indent();
1457                 print_entity(entity);
1458                 print_char('\n');
1459         }
1460 }
1461
1462 expression_classification_t is_constant_initializer(const initializer_t *initializer)
1463 {
1464         switch (initializer->kind) {
1465         case INITIALIZER_STRING:
1466         case INITIALIZER_DESIGNATOR:
1467                 return EXPR_CLASS_CONSTANT;
1468
1469         case INITIALIZER_VALUE:
1470                 return is_linker_constant(initializer->value.value);
1471
1472         case INITIALIZER_LIST: {
1473                 expression_classification_t all = EXPR_CLASS_CONSTANT;
1474                 for (size_t i = 0; i < initializer->list.len; ++i) {
1475                         initializer_t *sub_initializer = initializer->list.initializers[i];
1476                         expression_classification_t const cur = is_constant_initializer(sub_initializer);
1477                         if (all > cur) {
1478                                 all = cur;
1479                         }
1480                 }
1481                 return all;
1482         }
1483         }
1484         panic("invalid initializer kind found");
1485 }
1486
1487 /**
1488  * Checks if an expression references an object with a constant/known location
1489  * to the linker. Example:
1490  *  - "x", "*&x" with x being a global variable. The value of x need not be
1491  *         constant but the address of x is.
1492  *  - "a.b.c" when a has a constant/known location to the linker
1493  */
1494 static expression_classification_t is_object_with_linker_constant_address(
1495         const expression_t *expression)
1496 {
1497         switch (expression->kind) {
1498         case EXPR_UNARY_DEREFERENCE:
1499                 return is_linker_constant(expression->unary.value);
1500
1501         case EXPR_COMPOUND_LITERAL: {
1502                 const compound_literal_expression_t *literal
1503                         = &expression->compound_literal;
1504                 return literal->global_scope ||
1505                        ((literal->type->base.qualifiers & TYPE_QUALIFIER_CONST)
1506                         && is_constant_initializer(literal->initializer));
1507         }
1508
1509         case EXPR_SELECT: {
1510                 type_t *base_type = skip_typeref(expression->select.compound->base.type);
1511                 if (is_type_pointer(base_type)) {
1512                         /* it's a -> */
1513                         return is_linker_constant(expression->select.compound);
1514                 } else {
1515                         return is_object_with_linker_constant_address(expression->select.compound);
1516                 }
1517         }
1518
1519         case EXPR_ARRAY_ACCESS: {
1520                 expression_classification_t const ref = is_linker_constant(expression->array_access.array_ref);
1521                 expression_classification_t const idx = is_constant_expression(expression->array_access.index);
1522                 return ref < idx ? ref : idx;
1523         }
1524
1525         case EXPR_REFERENCE: {
1526                 entity_t *entity = expression->reference.entity;
1527                 if (!is_declaration(entity))
1528                         return EXPR_CLASS_VARIABLE;
1529
1530                 switch ((storage_class_tag_t)entity->declaration.storage_class) {
1531                 case STORAGE_CLASS_NONE:
1532                 case STORAGE_CLASS_EXTERN:
1533                 case STORAGE_CLASS_STATIC:
1534                         return
1535                                 entity->kind != ENTITY_VARIABLE ||
1536                                 !entity->variable.thread_local ? EXPR_CLASS_CONSTANT :
1537                                 EXPR_CLASS_VARIABLE;
1538
1539                 case STORAGE_CLASS_REGISTER:
1540                 case STORAGE_CLASS_TYPEDEF:
1541                 case STORAGE_CLASS_AUTO:
1542                         break;
1543                 }
1544                 return EXPR_CLASS_VARIABLE;
1545         }
1546
1547         case EXPR_ERROR:
1548                 return EXPR_CLASS_ERROR;
1549
1550         default:
1551                 return EXPR_CLASS_VARIABLE;
1552         }
1553 }
1554
1555 expression_classification_t is_linker_constant(const expression_t *expression)
1556 {
1557         switch (expression->kind) {
1558         case EXPR_STRING_LITERAL:
1559         case EXPR_FUNCNAME:
1560         case EXPR_LABEL_ADDRESS:
1561                 return EXPR_CLASS_CONSTANT;
1562
1563         case EXPR_COMPOUND_LITERAL:
1564                 return is_constant_initializer(expression->compound_literal.initializer);
1565
1566         case EXPR_UNARY_TAKE_ADDRESS:
1567                 return is_object_with_linker_constant_address(expression->unary.value);
1568
1569         case EXPR_UNARY_DEREFERENCE: {
1570                 type_t *real_type
1571                         = revert_automatic_type_conversion(expression->unary.value);
1572                 /* dereferencing a function is a NOP */
1573                 if (is_type_function(real_type)) {
1574                         return is_linker_constant(expression->unary.value);
1575                 }
1576                 /* FALLTHROUGH */
1577         }
1578
1579         case EXPR_UNARY_CAST: {
1580                 type_t *dest = skip_typeref(expression->base.type);
1581                 if (!is_type_pointer(dest) && (
1582                                 dest->kind != TYPE_ATOMIC                                               ||
1583                                 !(get_atomic_type_flags(dest->atomic.akind) & ATOMIC_TYPE_FLAG_INTEGER) ||
1584                                 get_atomic_type_size(dest->atomic.akind) < get_type_size(type_void_ptr)
1585                     ))
1586                         return is_constant_expression(expression);
1587
1588                 return is_linker_constant(expression->unary.value);
1589         }
1590
1591         case EXPR_BINARY_ADD:
1592         case EXPR_BINARY_SUB: {
1593                 expression_t *const left  = expression->binary.left;
1594                 expression_t *const right = expression->binary.right;
1595                 type_t       *const ltype = skip_typeref(left->base.type);
1596                 type_t       *const rtype = skip_typeref(right->base.type);
1597
1598                 if (is_type_pointer(ltype)) {
1599                         expression_classification_t const l = is_linker_constant(left);
1600                         expression_classification_t const r = is_constant_expression(right);
1601                         return l < r ? l : r;
1602                 } else if (is_type_pointer(rtype)) {
1603                         expression_classification_t const l = is_constant_expression(left);
1604                         expression_classification_t const r = is_linker_constant(right);
1605                         return l < r ? l : r;
1606                 } else if (!is_type_valid(ltype) || !is_type_valid(rtype)) {
1607                         return EXPR_CLASS_ERROR;
1608                 } else {
1609                         return is_constant_expression(expression);
1610                 }
1611         }
1612
1613         case EXPR_REFERENCE: {
1614                 entity_t *entity = expression->reference.entity;
1615                 if (!is_declaration(entity))
1616                         return EXPR_CLASS_VARIABLE;
1617
1618                 type_t *type = skip_typeref(entity->declaration.type);
1619                 if (is_type_function(type))
1620                         return EXPR_CLASS_CONSTANT;
1621                 if (is_type_array(type)) {
1622                         return is_object_with_linker_constant_address(expression);
1623                 }
1624                 /* Prevent stray errors */
1625                 if (!is_type_valid(type))
1626                         return EXPR_CLASS_ERROR;
1627                 return EXPR_CLASS_VARIABLE;
1628         }
1629
1630         case EXPR_ARRAY_ACCESS: {
1631                 type_t *const type =
1632                         skip_typeref(revert_automatic_type_conversion(expression));
1633                 if (!is_type_array(type))
1634                         return EXPR_CLASS_VARIABLE;
1635                 return is_linker_constant(expression->array_access.array_ref);
1636         }
1637
1638         case EXPR_CONDITIONAL: {
1639                 expression_t *const c = expression->conditional.condition;
1640                 expression_classification_t const cclass = is_constant_expression(c);
1641                 if (cclass != EXPR_CLASS_CONSTANT)
1642                         return cclass;
1643
1644                 if (fold_constant_to_bool(c)) {
1645                         expression_t const *const t = expression->conditional.true_expression;
1646                         return is_linker_constant(t != NULL ? t : c);
1647                 } else {
1648                         return is_linker_constant(expression->conditional.false_expression);
1649                 }
1650         }
1651
1652         case EXPR_SELECT: {
1653                 entity_t *entity = expression->select.compound_entry;
1654                 if (!is_declaration(entity))
1655                         return EXPR_CLASS_VARIABLE;
1656                 type_t *type = skip_typeref(entity->declaration.type);
1657                 if (is_type_array(type)) {
1658                         /* arrays automatically convert to their address */
1659                         expression_t *compound  = expression->select.compound;
1660                         type_t       *base_type = skip_typeref(compound->base.type);
1661                         if (is_type_pointer(base_type)) {
1662                                 /* it's a -> */
1663                                 return is_linker_constant(compound);
1664                         } else {
1665                                 return is_object_with_linker_constant_address(compound);
1666                         }
1667                 }
1668                 return EXPR_CLASS_VARIABLE;
1669         }
1670
1671         default:
1672                 return is_constant_expression(expression);
1673         }
1674 }
1675
1676 /**
1677  * Check if the given expression is a call to a builtin function
1678  * returning a constant result.
1679  */
1680 static expression_classification_t is_builtin_const_call(const expression_t *expression)
1681 {
1682         expression_t *function = expression->call.function;
1683         if (function->kind != EXPR_REFERENCE)
1684                 return EXPR_CLASS_VARIABLE;
1685         reference_expression_t *ref = &function->reference;
1686         if (ref->entity->kind != ENTITY_FUNCTION)
1687                 return EXPR_CLASS_VARIABLE;
1688
1689         switch (ref->entity->function.btk) {
1690         case BUILTIN_INF:
1691         case BUILTIN_NAN:
1692                 return EXPR_CLASS_CONSTANT;
1693         default:
1694                 return EXPR_CLASS_VARIABLE;
1695         }
1696
1697 }
1698
1699 static expression_classification_t is_constant_pointer(const expression_t *expression)
1700 {
1701         expression_classification_t const expr_class = is_constant_expression(expression);
1702         if (expr_class != EXPR_CLASS_VARIABLE)
1703                 return expr_class;
1704
1705         switch (expression->kind) {
1706         case EXPR_UNARY_CAST:
1707                 return is_constant_pointer(expression->unary.value);
1708         default:
1709                 return EXPR_CLASS_VARIABLE;
1710         }
1711 }
1712
1713 static expression_classification_t is_object_with_constant_address(const expression_t *expression)
1714 {
1715         switch (expression->kind) {
1716         case EXPR_SELECT: {
1717                 expression_t *compound      = expression->select.compound;
1718                 type_t       *compound_type = compound->base.type;
1719                 compound_type = skip_typeref(compound_type);
1720                 if (is_type_pointer(compound_type)) {
1721                         return is_constant_pointer(compound);
1722                 } else {
1723                         return is_object_with_constant_address(compound);
1724                 }
1725         }
1726
1727         case EXPR_ARRAY_ACCESS: {
1728                 array_access_expression_t const* const array_access =
1729                         &expression->array_access;
1730                 expression_classification_t const idx_class = is_constant_expression(array_access->index);
1731                 if (idx_class != EXPR_CLASS_CONSTANT)
1732                         return idx_class;
1733                 expression_classification_t const ref_addr = is_object_with_constant_address(array_access->array_ref);
1734                 expression_classification_t const ref_ptr  = is_constant_pointer(array_access->array_ref);
1735                 return ref_addr > ref_ptr ? ref_addr : ref_ptr;
1736         }
1737
1738         case EXPR_UNARY_DEREFERENCE:
1739                 return is_constant_pointer(expression->unary.value);
1740
1741         case EXPR_ERROR:
1742                 return EXPR_CLASS_ERROR;
1743
1744         default:
1745                 return EXPR_CLASS_VARIABLE;
1746         }
1747 }
1748
1749 expression_classification_t is_constant_expression(const expression_t *expression)
1750 {
1751         switch (expression->kind) {
1752         case EXPR_LITERAL_CHARACTER:
1753         case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1754         case EXPR_ENUM_CONSTANT:
1755         case EXPR_LITERAL_BOOLEAN:
1756         case EXPR_LITERAL_MS_NOOP:
1757                 return EXPR_CLASS_CONSTANT;
1758
1759         {
1760                 type_t *type;
1761         case EXPR_ALIGNOF:
1762                 type = skip_typeref(expression->typeprop.type);
1763                 goto check_type;
1764
1765         case EXPR_CLASSIFY_TYPE:
1766                 type = skip_typeref(expression->classify_type.type_expression->base.type);
1767                 goto check_type;
1768
1769         case EXPR_LITERAL_INTEGER:
1770         case EXPR_LITERAL_FLOATINGPOINT:
1771                 type = skip_typeref(expression->base.type);
1772                 goto check_type;
1773
1774         case EXPR_OFFSETOF:
1775                 type = skip_typeref(expression->offsetofe.type);
1776                 goto check_type;
1777
1778         case EXPR_SIZEOF:
1779                 type = skip_typeref(expression->typeprop.type);
1780                 if (is_type_array(type) && type->array.is_vla)
1781                         return EXPR_CLASS_VARIABLE;
1782                 goto check_type;
1783
1784 check_type:
1785                 return is_type_valid(type) ? EXPR_CLASS_CONSTANT : EXPR_CLASS_ERROR;
1786         }
1787
1788         case EXPR_BUILTIN_CONSTANT_P: {
1789                 expression_classification_t const c = is_constant_expression(expression->builtin_constant.value);
1790                 return c != EXPR_CLASS_ERROR ? EXPR_CLASS_CONSTANT : EXPR_CLASS_ERROR;
1791         }
1792
1793         case EXPR_STRING_LITERAL:
1794         case EXPR_FUNCNAME:
1795         case EXPR_LABEL_ADDRESS:
1796         case EXPR_SELECT:
1797         case EXPR_VA_START:
1798         case EXPR_VA_ARG:
1799         case EXPR_VA_COPY:
1800         case EXPR_STATEMENT:
1801         case EXPR_UNARY_POSTFIX_INCREMENT:
1802         case EXPR_UNARY_POSTFIX_DECREMENT:
1803         case EXPR_UNARY_PREFIX_INCREMENT:
1804         case EXPR_UNARY_PREFIX_DECREMENT:
1805         case EXPR_UNARY_ASSUME: /* has VOID type */
1806         case EXPR_UNARY_DEREFERENCE:
1807         case EXPR_UNARY_DELETE:
1808         case EXPR_UNARY_DELETE_ARRAY:
1809         case EXPR_UNARY_THROW:
1810         case EXPR_BINARY_ASSIGN:
1811         case EXPR_BINARY_MUL_ASSIGN:
1812         case EXPR_BINARY_DIV_ASSIGN:
1813         case EXPR_BINARY_MOD_ASSIGN:
1814         case EXPR_BINARY_ADD_ASSIGN:
1815         case EXPR_BINARY_SUB_ASSIGN:
1816         case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1817         case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1818         case EXPR_BINARY_BITWISE_AND_ASSIGN:
1819         case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1820         case EXPR_BINARY_BITWISE_OR_ASSIGN:
1821         case EXPR_BINARY_COMMA:
1822         case EXPR_ARRAY_ACCESS:
1823                 return EXPR_CLASS_VARIABLE;
1824
1825         case EXPR_REFERENCE: {
1826                 type_t *const type = skip_typeref(expression->base.type);
1827                 return is_type_valid(type) ? EXPR_CLASS_VARIABLE : EXPR_CLASS_ERROR;
1828         }
1829
1830         case EXPR_UNARY_TAKE_ADDRESS:
1831                 return is_object_with_constant_address(expression->unary.value);
1832
1833         case EXPR_CALL:
1834                 return is_builtin_const_call(expression);
1835
1836         case EXPR_UNARY_NEGATE:
1837         case EXPR_UNARY_PLUS:
1838         case EXPR_UNARY_BITWISE_NEGATE:
1839         case EXPR_UNARY_NOT:
1840                 return is_constant_expression(expression->unary.value);
1841
1842         case EXPR_UNARY_CAST: {
1843                 type_t *const type = skip_typeref(expression->base.type);
1844                 if (is_type_scalar(type))
1845                         return is_constant_expression(expression->unary.value);
1846                 if (!is_type_valid(type))
1847                         return EXPR_CLASS_ERROR;
1848                 return EXPR_CLASS_VARIABLE;
1849         }
1850
1851         case EXPR_BINARY_ADD:
1852         case EXPR_BINARY_SUB:
1853         case EXPR_BINARY_MUL:
1854         case EXPR_BINARY_DIV:
1855         case EXPR_BINARY_MOD:
1856         case EXPR_BINARY_EQUAL:
1857         case EXPR_BINARY_NOTEQUAL:
1858         case EXPR_BINARY_LESS:
1859         case EXPR_BINARY_LESSEQUAL:
1860         case EXPR_BINARY_GREATER:
1861         case EXPR_BINARY_GREATEREQUAL:
1862         case EXPR_BINARY_BITWISE_AND:
1863         case EXPR_BINARY_BITWISE_OR:
1864         case EXPR_BINARY_BITWISE_XOR:
1865         case EXPR_BINARY_SHIFTLEFT:
1866         case EXPR_BINARY_SHIFTRIGHT:
1867         case EXPR_BINARY_ISGREATER:
1868         case EXPR_BINARY_ISGREATEREQUAL:
1869         case EXPR_BINARY_ISLESS:
1870         case EXPR_BINARY_ISLESSEQUAL:
1871         case EXPR_BINARY_ISLESSGREATER:
1872         case EXPR_BINARY_ISUNORDERED: {
1873                 expression_classification_t const l = is_constant_expression(expression->binary.left);
1874                 expression_classification_t const r = is_constant_expression(expression->binary.right);
1875                 return l < r ? l : r;
1876         }
1877
1878         case EXPR_BINARY_LOGICAL_AND: {
1879                 expression_t const         *const left   = expression->binary.left;
1880                 expression_classification_t const lclass = is_constant_expression(left);
1881                 if (lclass != EXPR_CLASS_CONSTANT)
1882                         return lclass;
1883                 if (!fold_constant_to_bool(left))
1884                         return EXPR_CLASS_CONSTANT;
1885                 return is_constant_expression(expression->binary.right);
1886         }
1887
1888         case EXPR_BINARY_LOGICAL_OR: {
1889                 expression_t const         *const left   = expression->binary.left;
1890                 expression_classification_t const lclass = is_constant_expression(left);
1891                 if (lclass != EXPR_CLASS_CONSTANT)
1892                         return lclass;
1893                 if (fold_constant_to_bool(left))
1894                         return EXPR_CLASS_CONSTANT;
1895                 return is_constant_expression(expression->binary.right);
1896         }
1897
1898         case EXPR_COMPOUND_LITERAL:
1899                 return is_constant_initializer(expression->compound_literal.initializer);
1900
1901         case EXPR_CONDITIONAL: {
1902                 expression_t               *const condition = expression->conditional.condition;
1903                 expression_classification_t const cclass    = is_constant_expression(condition);
1904                 if (cclass != EXPR_CLASS_CONSTANT)
1905                         return cclass;
1906
1907                 if (fold_constant_to_bool(condition)) {
1908                         expression_t const *const t = expression->conditional.true_expression;
1909                         return t == NULL ? EXPR_CLASS_CONSTANT : is_constant_expression(t);
1910                 } else {
1911                         return is_constant_expression(expression->conditional.false_expression);
1912                 }
1913         }
1914
1915         case EXPR_ERROR:
1916                 return EXPR_CLASS_ERROR;
1917         }
1918         panic("invalid expression");
1919 }
1920
1921 void init_ast(void)
1922 {
1923         obstack_init(&ast_obstack);
1924 }
1925
1926 void exit_ast(void)
1927 {
1928         obstack_free(&ast_obstack, NULL);
1929 }