improve ast printing
[cparser] / parser.c
index f823725..d5d2c5e 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -3,16 +3,42 @@
 #include <assert.h>
 #include <stdarg.h>
 
-#include "lexer_t.h"
+#include "parser.h"
+#include "lexer.h"
 #include "token_t.h"
 #include "type_t.h"
+#include "type_hash.h"
 #include "ast_t.h"
 #include "adt/bitfiddle.h"
 #include "adt/error.h"
+#include "adt/array.h"
 
-#define PRINT_TOKENS
+//#define PRINT_TOKENS
+#define MAX_LOOKAHEAD 2
 
-static token_t token;
+struct environment_entry_t {
+       symbol_t      *symbol;
+       declaration_t *old_declaration;
+       const void    *old_context;
+};
+
+static token_t               token;
+static token_t               lookahead_buffer[MAX_LOOKAHEAD];
+static int                   lookahead_bufpos;
+static struct obstack        environment_obstack;
+static environment_entry_t **environment_stack = NULL;
+static context_t            *context           = NULL;
+static declaration_t        *last_declaration  = NULL;
+
+static
+statement_t *parse_compound_statement(void);
+static
+statement_t *parse_statement(void);
+
+static
+expression_t *parse_sub_expression(unsigned precedence);
+static
+expression_t *parse_expression(void);
 
 static inline
 void *allocate_ast_zero(size_t size)
@@ -22,10 +48,33 @@ void *allocate_ast_zero(size_t size)
        return res;
 }
 
+static inline
+void *allocate_type_zero(size_t size)
+{
+       void *res = obstack_alloc(type_obst, size);
+       memset(res, 0, size);
+       return res;
+}
+
+/**
+ * returns the top element of the environment stack
+ */
+static inline
+size_t environment_top()
+{
+       return ARR_LEN(environment_stack);
+}
+
+
+
 static inline
 void next_token(void)
 {
-       lexer_next_token(&token);
+       token                              = lookahead_buffer[lookahead_bufpos];
+       lookahead_buffer[lookahead_bufpos] = lexer_token;
+       lexer_next_token();
+
+       lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 
 #ifdef PRINT_TOKENS
        print_token(stderr, &token);
@@ -33,6 +82,14 @@ void next_token(void)
 #endif
 }
 
+static inline
+const token_t *la(int num)
+{
+       assert(num > 0 && num <= MAX_LOOKAHEAD);
+       int pos = (num-1) % MAX_LOOKAHEAD;
+       return & lookahead_buffer[pos];
+}
+
 static inline
 void eat(token_type_t type)
 {
@@ -40,7 +97,7 @@ void eat(token_type_t type)
        next_token();
 }
 
-void parser_print_error_prefix(void)
+void parser_print_error_prefix_pos(const source_position_t source_position)
 {
     fputs(source_position.input_name, stderr);
     fputc(':', stderr);
@@ -48,6 +105,11 @@ void parser_print_error_prefix(void)
     fputs(": error: ", stderr);
 }
 
+void parser_print_error_prefix(void)
+{
+       parser_print_error_prefix_pos(token.source_position);
+}
+
 static
 void parse_error(const char *message)
 {
@@ -86,12 +148,12 @@ void parse_error_expected(const char *message, ...)
 }
 
 static
-void eat_until_semi(void)
+void eat_until(int token_type)
 {
-       while(token.type != ';') {
-               next_token();
+       while(token.type != token_type) {
                if(token.type == T_EOF)
                        return;
+               next_token();
        }
        next_token();
 }
@@ -99,11 +161,250 @@ void eat_until_semi(void)
 #define expect(expected)                           \
     if(UNLIKELY(token.type != (expected))) {       \
         parse_error_expected(NULL, (expected), 0); \
-        eat_until_semi();                          \
+        eat_until(';');                            \
         return NULL;                               \
     }                                              \
     next_token();
 
+#define expect_void(expected)                      \
+    if(UNLIKELY(token.type != (expected))) {       \
+        parse_error_expected(NULL, (expected), 0); \
+        eat_until(';');                            \
+        return;                                    \
+    }                                              \
+    next_token();
+
+static void set_context(context_t *new_context)
+{
+       context = new_context;
+
+       declaration_t *declaration = new_context->declarations;
+       if(declaration != NULL) {
+               while(1) {
+                       if(declaration->next == NULL)
+                               break;
+                       declaration = declaration->next;
+               }
+       }
+
+       last_declaration = declaration;
+}
+
+/**
+ * pushs an environment_entry on the environment stack and links the
+ * corresponding symbol to the new entry
+ */
+static inline
+void environment_push(declaration_t *declaration, const void *context)
+{
+       environment_entry_t *entry
+               = obstack_alloc(&environment_obstack, sizeof(entry[0]));
+       memset(entry, 0, sizeof(entry[0]));
+
+       int top = ARR_LEN(environment_stack);
+       ARR_RESIZE(environment_stack, top + 1);
+       environment_stack[top] = entry;
+
+       assert(declaration->source_position.input_name != NULL);
+
+       symbol_t *symbol = declaration->symbol;
+       assert(declaration != symbol->declaration);
+
+       if(symbol->context == context) {
+               if(symbol->declaration != NULL) {
+                       assert(symbol->declaration != NULL);
+                       parser_print_error_prefix_pos(declaration->source_position);
+                       fprintf(stderr, "multiple definitions for symbol '%s'.\n",
+                                       symbol->string);
+                       parser_print_error_prefix_pos(symbol->declaration->source_position);
+                       fprintf(stderr, "this is the location of the previous declaration.\n");
+               }
+       }
+
+       entry->old_declaration = symbol->declaration;
+       entry->old_context     = symbol->context;
+       entry->symbol          = symbol;
+       symbol->declaration    = declaration;
+       symbol->context        = context;
+}
+
+/**
+ * pops symbols from the environment stack until @p new_top is the top element
+ */
+static inline
+void environment_pop_to(size_t new_top)
+{
+       environment_entry_t *entry = NULL;
+       size_t top = ARR_LEN(environment_stack);
+       size_t i;
+
+       if(new_top == top)
+               return;
+
+       assert(new_top < top);
+       i = top;
+       do {
+               entry = environment_stack[i - 1];
+
+               symbol_t *symbol = entry->symbol;
+
+               symbol->declaration = entry->old_declaration;
+               symbol->context     = entry->old_context;
+
+               --i;
+       } while(i != new_top);
+       obstack_free(&environment_obstack, entry);
+
+       ARR_SHRINKLEN(environment_stack, (int) new_top);
+}
+
+
+
+static expression_t *parse_constant_expression(void)
+{
+       /* TODO: not correct yet */
+       return parse_expression();
+}
+
+static expression_t *parse_assignment_expression(void)
+{
+       /* TODO: not correct yet */
+       return parse_expression();
+}
+
+static void parse_compound_type_entries(void);
+static void parse_declarator(declaration_t *declaration,
+                             storage_class_t storage_class, type_t *type,
+                             int may_omit_identifier);
+static void maybe_push_declaration(declaration_t *declaration);
+static void record_declaration(declaration_t *declaration);
+
+typedef struct declaration_specifiers_t  declaration_specifiers_t;
+struct declaration_specifiers_t {
+       storage_class_t  storage_class;
+       type_t          *type;
+};
+
+static type_t *parse_struct_specifier(void)
+{
+       eat(T_struct);
+
+       compound_type_t *struct_type = allocate_type_zero(sizeof(struct_type[0]));
+       struct_type->type.type       = TYPE_COMPOUND_STRUCT;
+       struct_type->source_position = token.source_position;
+
+       int         top          = environment_top();
+       context_t  *last_context = context;
+       set_context(&struct_type->context);
+
+       if(token.type == T_IDENTIFIER) {
+               next_token();
+               if(token.type == '{') {
+                       parse_compound_type_entries();
+               }
+       } else if(token.type == '{') {
+               parse_compound_type_entries();
+       } else {
+               parse_error_expected("problem while parsing struct type specifiers",
+                                    T_IDENTIFIER, '{', 0);
+               struct_type = NULL;
+       }
+
+       assert(context == &struct_type->context);
+       set_context(last_context);
+       environment_pop_to(top);
+
+       return (type_t*) struct_type;
+}
+
+static type_t *parse_union_specifier(void)
+{
+       eat(T_union);
+
+       compound_type_t *union_type = allocate_type_zero(sizeof(union_type[0]));
+       union_type->type.type       = TYPE_COMPOUND_UNION;
+       union_type->source_position = token.source_position;
+
+       int         top          = environment_top();
+       context_t  *last_context = context;
+       set_context(&union_type->context);
+
+       if(token.type == T_IDENTIFIER) {
+               union_type->symbol = token.v.symbol;
+               next_token();
+               if(token.type == '{') {
+                       parse_compound_type_entries();
+               }
+       } else if(token.type == '{') {
+               parse_compound_type_entries();
+       } else {
+               parse_error_expected("problem while parsing union type specifiers",
+                                    T_IDENTIFIER, '{');
+               union_type = NULL;
+       }
+
+       assert(context == &union_type->context);
+       set_context(last_context);
+       environment_pop_to(top);
+
+       return (type_t*) union_type;
+}
+
+static void parse_enum_type_entries()
+{
+       eat('{');
+
+       if(token.type == '}') {
+               next_token();
+               parse_error("empty enum not allowed");
+               return;
+       }
+
+       do {
+               if(token.type != T_IDENTIFIER) {
+                       parse_error_expected("problem while parsing enum entry",
+                                            T_IDENTIFIER, 0);
+                       eat_until('}');
+                       return;
+               }
+               next_token();
+
+               if(token.type == '=') {
+                       parse_constant_expression();
+               }
+
+               if(token.type != ',')
+                       break;
+               next_token();
+       } while(token.type != '}');
+
+       expect_void('}');
+}
+
+static type_t *parse_enum_specifier(void)
+{
+       eat(T_enum);
+
+       enum_type_t *enum_type     = allocate_type_zero(sizeof(enum_type[0]));
+       enum_type->type.type       = TYPE_ENUM;
+       enum_type->source_position = token.source_position;
+
+       if(token.type == T_IDENTIFIER) {
+               enum_type->symbol = token.v.symbol;
+               next_token();
+               if(token.type == '{') {
+                       parse_enum_type_entries();
+               }
+       } else if(token.type == '{') {
+               parse_enum_type_entries();
+       } else {
+               parse_error_expected("problem while parsing enum type specifiers",
+                                    T_IDENTIFIER, '{');
+       }
+
+       return (type_t*) enum_type;
+}
+
 typedef enum {
        SPECIFIER_SIGNED    = 1 << 0,
        SPECIFIER_UNSIGNED  = 1 << 1,
@@ -124,34 +425,79 @@ typedef enum {
 #endif
 } specifiers_t;
 
-typedef enum {
-       TYPE_QUALIFIER_CONST    = 1 << 0,
-       TYPE_QUALIFIER_RESTRICT = 1 << 1,
-       TYPE_QUALIFIER_VOLATILE = 1 << 2,
-       TYPE_QUALIFIER_INLINE   = 1 << 3,
-} type_qualifier_t;
+#define STORAGE_CLASSES     \
+       case T_typedef:         \
+       case T_extern:          \
+       case T_static:          \
+       case T_auto:            \
+       case T_register:
 
-typedef enum {
-       STORAGE_CLASS_NONE,
-       STORAGE_CLASS_TYPEDEF,
-       STORAGE_CLASS_EXTERN,
-       STORAGE_CLASS_STATIC,
-       STORAGE_CLASS_AUTO,
-       STORAGE_CLASS_REGISTER
-} storage_class_t;
+#define TYPE_QUALIFIERS     \
+       case T_const:           \
+       case T_restrict:        \
+       case T_volatile:        \
+       case T_inline:          \
+       case T___extension__:
 
-typedef struct declaration_specifiers_t  declaration_specifiers_t;
-struct declaration_specifiers_t {
-       storage_class_t  storage_class;
-       int              type_qualifiers;
-};
+#ifdef PROVIDE_COMPLEX
+#define COMPLEX_SPECIFIERS  \
+       case T__Complex:
+#else
+#define COMPLEX_SPECIFIERS
+#endif
+
+#ifdef PROVIDE_IMAGINARY
+#define IMAGINARY_SPECIFIERS \
+       case T__Imaginary:
+#else
+#define IMAGINARY_SPECIFIERS
+#endif
+
+#define TYPE_SPECIFIERS     \
+       case T_void:            \
+       case T_char:            \
+       case T_short:           \
+       case T_int:             \
+       case T_long:            \
+       case T_float:           \
+       case T_double:          \
+       case T_signed:          \
+       case T_unsigned:        \
+       case T__Bool:           \
+       case T_struct:          \
+       case T_union:           \
+       case T_enum:            \
+       COMPLEX_SPECIFIERS      \
+       IMAGINARY_SPECIFIERS
+
+#define DECLARATION_START   \
+       STORAGE_CLASSES         \
+       TYPE_QUALIFIERS         \
+       TYPE_SPECIFIERS
+
+static
+type_t *create_builtin_type(symbol_t *symbol)
+{
+       builtin_type_t *type = allocate_type_zero(sizeof(type[0]));
+       type->type.type      = TYPE_BUILTIN;
+       type->symbol         = symbol;
+
+       type_t *result = typehash_insert((type_t*) type);
+       if(result != (type_t*) type) {
+               obstack_free(type_obst, type);
+       }
+
+       return result;
+}
 
 static
 void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
 {
-       type_type_t        type_type       = TYPE_INVALID;
-       atomic_type_type_t atomic_type     = ATOMIC_TYPE_INVALID;
-       unsigned           type_specifiers = 0;
+       declaration_t *declaration;
+       type_t        *type            = NULL;
+       unsigned       type_qualifiers = 0;
+       unsigned       type_specifiers = 0;
+       int            newtype         = 0;
 
        while(1) {
                switch(token.type) {
@@ -176,7 +522,7 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                /* type qualifiers */
 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
                case token:                                                     \
-                       specifiers->type_qualifiers |= qualifier;                   \
+                       type_qualifiers |= qualifier;                               \
                        next_token();                                               \
                        break;
 
@@ -185,6 +531,11 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
                MATCH_TYPE_QUALIFIER(T_inline,   TYPE_QUALIFIER_INLINE);
 
+               case T___extension__:
+                       /* TODO */
+                       next_token();
+                       break;
+
                /* type specifiers */
 #define MATCH_SPECIFIER(token, specifier, name)                         \
                case token:                                                     \
@@ -214,7 +565,7 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                case T_long:
                        next_token();
                        if(type_specifiers & SPECIFIER_LONG_LONG) {
-                               parse_error("too many long type specifiers given");
+                               parse_error("multiple type specifiers given");
                        } else if(type_specifiers & SPECIFIER_LONG) {
                                type_specifiers |= SPECIFIER_LONG_LONG;
                        } else {
@@ -222,19 +573,44 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                        }
                        break;
 
+               /* TODO: if type != NULL for the following rules issue an error */
                case T_struct:
+                       type = parse_struct_specifier();
+                       break;
+               case T_union:
+                       type = parse_union_specifier();
+                       break;
                case T_enum:
-                       /* TODO */
-                       assert(0);
+                       type = parse_enum_specifier();
+                       break;
+               case T___builtin_va_list:
+                       type = create_builtin_type(token.v.symbol);
+                       next_token();
+                       break;
+
+               case T_IDENTIFIER:
+                       declaration = token.v.symbol->declaration;
+                       if(declaration == NULL ||
+                                       declaration->storage_class != STORAGE_CLASS_TYPEDEF) {
+                               goto finish_specifiers;
+                       }
+
+                       type = declaration->type;
+                       assert(type != NULL);
+                       next_token();
                        break;
 
                /* function specifier */
                default:
-                       return;;
+                       goto finish_specifiers;
                }
        }
 
-       if(type_type == TYPE_INVALID) {
+finish_specifiers:
+
+       if(type == NULL) {
+               atomic_type_type_t atomic_type;
+
                /* match valid basic types */
                switch(type_specifiers) {
                case SPECIFIER_VOID:
@@ -278,14 +654,16 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_ULONG;
                        break;
-               case SPECIFIER_LONG_LONG:
-               case SPECIFIER_SIGNED | SPECIFIER_LONG_LONG:
-               case SPECIFIER_LONG_LONG | SPECIFIER_INT:
-               case SPECIFIER_SIGNED | SPECIFIER_LONG_LONG | SPECIFIER_INT:
+               case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
+               case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
+               case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
+               case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
+                       | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_LONGLONG;
                        break;
-               case SPECIFIER_UNSIGNED | SPECIFIER_LONG_LONG:
-               case SPECIFIER_UNSIGNED | SPECIFIER_LONG_LONG | SPECIFIER_INT:
+               case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
+               case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
+                       | SPECIFIER_INT:
                        atomic_type = ATOMIC_TYPE_ULONGLONG;
                        break;
                case SPECIFIER_FLOAT:
@@ -334,82 +712,520 @@ void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                        } else {
                                parse_error("multiple datatypes in declaration");
                        }
+                       atomic_type = ATOMIC_TYPE_INVALID;
                }
+
+               atomic_type_t *atype = allocate_type_zero(sizeof(atype[0]));
+               atype->type.type     = TYPE_ATOMIC;
+               atype->atype         = atomic_type;
+               newtype              = 1;
+
+               type = (type_t*) atype;
        } else {
                if(type_specifiers != 0) {
                        parse_error("multiple datatypes in declaration");
                }
        }
+
+       type->qualifiers = type_qualifiers;
+
+       type_t *result = typehash_insert(type);
+       if(newtype && result != (type_t*) type) {
+               obstack_free(type_obst, type);
+       }
+
+       specifiers->type = result;
 }
 
-typedef struct declarator_t declarator_t;
-struct declarator_t {
-       /* pointer stuff... */
-       symbol_t     *symbol;
+static
+unsigned parse_type_qualifiers()
+{
+       unsigned type_qualifiers = 0;
 
-       declarator_t *next;
-};
+       while(1) {
+               switch(token.type) {
+               /* type qualifiers */
+               MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
+               MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
+               MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
+               MATCH_TYPE_QUALIFIER(T_inline,   TYPE_QUALIFIER_INLINE);
+
+               default:
+                       return type_qualifiers;
+               }
+       }
+}
 
-declarator_t *parse_declarator(void)
+static
+int parse_pointers(void)
 {
+       int result = 0;
+
        while(token.type == '*') {
-               /* pointer */
                next_token();
-               //parse_type_qualifiers();
+               result++;
        }
 
-       declarator_t *declarator;
+       return result;
+}
+
+static
+type_t *make_pointers(type_t *type, int count)
+{
+       for(int i = 0; i < count; ++i) {
+               pointer_type_t *pointer_type
+                       = allocate_type_zero(sizeof(pointer_type[0]));
+               pointer_type->type.type = TYPE_POINTER;
+               pointer_type->points_to = type;
+
+               pointer_type->type.qualifiers = parse_type_qualifiers();
+
+               type_t *result = typehash_insert((type_t*) pointer_type);
+               if(result != (type_t*) pointer_type) {
+                       obstack_free(type_obst, pointer_type);
+               }
+
+               type = result;
+       }
+
+       return type;
+}
+
+static
+void parse_identifier_list(void)
+{
+       while(1) {
+               if(token.type != T_IDENTIFIER) {
+                       parse_error_expected("problem while parsing parameter identifier "
+                                            "list", T_IDENTIFIER, 0);
+                       return;
+               }
+               next_token();
+               if(token.type != ',')
+                       break;
+               next_token();
+       }
+}
+
+static
+declaration_t *parse_parameter(void)
+{
+       declaration_specifiers_t specifiers;
+       memset(&specifiers, 0, sizeof(specifiers));
+
+       parse_declaration_specifiers(&specifiers);
+
+       declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
+       parse_declarator(declaration, specifiers.storage_class,
+                        specifiers.type, 1);
+
+#if 0
+       if(declaration->symbol != NULL) {
+               maybe_push_declaration(declaration);
+               record_declaration(declaration);
+       }
+#endif
+
+       return declaration;
+}
+
+static
+void parse_parameters(method_type_t *type)
+{
+       if(token.type == T_IDENTIFIER) {
+               symbol_t      *symbol      = token.v.symbol;
+               declaration_t *declaration = symbol->declaration;
+               if(declaration == NULL
+                               || declaration->storage_class != STORAGE_CLASS_TYPEDEF) {
+                       parse_identifier_list();
+                       return;
+               }
+       }
+
+       if(token.type == ')') {
+               type->unspecified_parameters = 1;
+               return;
+       }
+       if(token.type == T_void && la(1)->type == ')') {
+               next_token();
+               return;
+       }
+
+       declaration_t *declaration;
+       method_parameter_type_t *parameter_type;
+       method_parameter_type_t *last_parameter_type = NULL;
+
+       while(1) {
+               switch(token.type) {
+               case T_DOTDOTDOT:
+                       next_token();
+                       type->variadic = 1;
+                       return;
+
+               case T_IDENTIFIER:
+               DECLARATION_START
+                       declaration = parse_parameter();
+
+                       parameter_type = allocate_type_zero(sizeof(parameter_type[0]));
+                       parameter_type->type   = declaration->type;
+                       parameter_type->symbol = declaration->symbol;
+
+                       if(last_parameter_type != NULL) {
+                               last_parameter_type->next = parameter_type;
+                       } else {
+                               type->parameter_types = parameter_type;
+                       }
+                       last_parameter_type = parameter_type;
+                       break;
+
+               default:
+                       return;
+               }
+               if(token.type != ',')
+                       return;
+               next_token();
+       }
+}
+
+static
+void parse_attributes(void)
+{
+       while(token.type == T___attribute__) {
+               next_token();
+
+               expect_void('(');
+               int depth = 1;
+               while(depth > 0) {
+                       switch(token.type) {
+                       case T_EOF:
+                               parse_error("EOF while parsing attribute");
+                               break;
+                       case '(':
+                               next_token();
+                               depth++;
+                               break;
+                       case ')':
+                               next_token();
+                               depth--;
+                               break;
+                       default:
+                               next_token();
+                       }
+               }
+       }
+}
+
+typedef struct declarator_part declarator_part;
+struct declarator_part {
+       int              pointers;
+       method_type_t   *method_type;
+       declarator_part *inner;
+};
+
+static struct obstack  temp_obst;
+
+static
+declarator_part *parse_inner_declarator(declaration_t *declaration)
+{
+       declarator_part *part = obstack_alloc(&temp_obst, sizeof(part[0]));
+       memset(part, 0, sizeof(part[0]));
+
+       part->pointers = parse_pointers();
 
        switch(token.type) {
        case T_IDENTIFIER:
-               declarator = allocate_ast_zero(sizeof(declarator[0]));
-               declarator->symbol = token.v.symbol;
+               declaration->symbol          = token.v.symbol;
+               declaration->source_position = token.source_position;
                next_token();
-               return declarator;
+               break;
        case '(':
                next_token();
-               declarator = parse_declarator();
-               expect(')')
-               return declarator;
+               part->inner = parse_inner_declarator(declaration);
+               expect(')');
+               break;
        default:
-               parse_error("problem while parsing declarator");
+               parse_error_expected("problem while parsing declarator", T_IDENTIFIER,
+                                    '(', 0);
        }
 
-       if(token.type == '(') {
-               next_token();
+       while(1) {
+               switch(token.type) {
+               case '(':
+                       next_token();
 
-               /* parse parameter-type-list or identifier-list */
+#if 0
+                       int         top          = environment_top();
+                       context_t  *last_context = context;
+                       set_context(&declaration->context);
+#endif
 
-               expect(')');
-       } else if(token.type == '[') {
+                       method_type_t *method_type
+                               = allocate_type_zero(sizeof(method_type[0]));
+                       method_type->type.type   = TYPE_METHOD;
+
+                       parse_parameters(method_type);
+
+#if 0
+                       assert(context == &declaration->context);
+                       set_context(last_context);
+                       environment_pop_to(top);
+#endif
+
+                       part->method_type = method_type;
+
+                       expect(')');
+                       break;
+               case '[':
+                       next_token();
+
+                       if(token.type == T_static) {
+                               next_token();
+                       }
+
+                       unsigned type_qualifiers = parse_type_qualifiers();
+                       if(type_qualifiers != 0) {
+                               if(token.type == T_static) {
+                                       next_token();
+                               }
+                       }
+
+                       /* TODO */
+
+                       if(token.type == '*' && la(1)->type == ']') {
+                               next_token();
+                       } else if(token.type != ']') {
+                               parse_assignment_expression();
+                       }
+
+                       expect(']');
+                       break;
+               default:
+                       goto declarator_finished;
+               }
+       }
+
+declarator_finished:
+       parse_attributes();
+
+       return part;
+}
+
+static
+type_t *construct_declarator_type(declarator_part *part, type_t *type)
+{
+       do {
+               type = make_pointers(type, part->pointers);
+
+               method_type_t *method_type = part->method_type;
+               if(method_type != NULL) {
+                       method_type->result_type = type;
+
+                       type = (type_t*) method_type;
+               }
+
+               part = part->inner;
+       } while(part != NULL);
+
+       return type;
+}
+
+static
+void parse_declarator(declaration_t *declaration, storage_class_t storage_class,
+                      type_t *type, int may_omit_identifier)
+{
+       (void) may_omit_identifier;
+       declarator_part *part = parse_inner_declarator(declaration);
+
+       declaration->type          = construct_declarator_type(part, type);
+       declaration->storage_class = storage_class;
+       obstack_free(&temp_obst, part);
+}
+
+#if 0
+static
+void parse_declarator(declaration_t *declaration, storage_class_t storage_class,
+                      type_t *type, int may_omit_identifier)
+{
+       ir_type *outer_type = parse_pointers(type);
+
+       declaration->storage_class = storage_class;
+       declaration->type          = outer_type;
+
+       switch(token.type) {
+       case T_IDENTIFIER:
+               declaration->symbol          = token.v.symbol;
+               declaration->source_position = token.source_position;
                next_token();
+               break;
+       case '(':
+               next_token();
+               parse_declarator(declaration, storage_class, type, 0);
+               expect_void(')');
+               break;
+       default:
+               if(may_omit_identifier)
+                       goto declarator_finished;
+               parse_error_expected("problem while parsing declarator", T_IDENTIFIER,
+                                    '(', 0);
+       }
+
+       while(1) {
+               switch(token.type) {
+               case '(':
+                       next_token();
+
+                       int         top          = environment_top();
+                       context_t  *last_context = context;
+                       set_context(&declaration->context);
+
+                       method_type_t *method_type
+                               = allocate_type_zero(sizeof(method_type[0]));
+                       method_type->type.type   = TYPE_METHOD;
+                       method_type->result_type = outer_type;
+
+                       parse_parameters(method_type);
+
+                       assert(context == &declaration->context);
+                       set_context(last_context);
+                       environment_pop_to(top);
+
+                       replace_type(&declaration->type, outer_type,
+                                    method_type);
+
+                       expect_void(')');
+                       break;
+               case '[':
+                       next_token();
+
+                       if(token.type == T_static) {
+                               next_token();
+                       }
 
-               /* multiple type qualifiers, and static */
+                       unsigned type_qualifiers = parse_type_qualifiers();
+                       if(type_qualifiers != 0) {
+                               if(token.type == T_static) {
+                                       next_token();
+                               }
+                       }
 
-               /* assignment_expression or '*' or nothing */
+                       if(token.type == '*' && la(1)->type == ']') {
+                               next_token();
+                       } else if(token.type != ']') {
+                               parse_assignment_expression();
+                       }
 
-               expect(']');
+                       expect_void(']');
+                       break;
+               default:
+                       goto declarator_finished;
+               }
        }
 
-       return declarator;
+declarator_finished:
+       parse_attributes();
+}
+#endif
+
+static void record_declaration(declaration_t *declaration)
+{
+       if(last_declaration != NULL) {
+               last_declaration->next = declaration;
+       } else {
+               if(context != NULL)
+                       context->declarations = declaration;
+       }
+       last_declaration = declaration;
 }
 
+static
+void maybe_push_declaration(declaration_t *declaration)
+{
+       symbol_t *symbol = declaration->symbol;
+
+       if(symbol != NULL) {
+               environment_push(declaration, context);
+       }
+}
+
+static
 void parse_init_declarators(const declaration_specifiers_t *specifiers)
 {
-       (void) specifiers;
-       declarator_t *declarator = parse_declarator();
-       if(token.type == '=') {
+       while(1) {
+               declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
+
+               parse_declarator(declaration, specifiers->storage_class,
+                                specifiers->type, 0);
+               maybe_push_declaration(declaration);
+               record_declaration(declaration);
+               if(token.type == '=') {
+                       next_token();
+                       if(token.type == '{') {
+                               // TODO
+                               expect_void('}');
+                       } else {
+                               parse_assignment_expression();
+                       }
+               } else if(token.type == '{') {
+                       statement_t *statement = parse_compound_statement();
+                       declaration->statement = statement;
+                       return;
+               }
+
+               if(token.type != ',')
+                       break;
                next_token();
-               //parse_initialize();
        }
-       (void) declarator;
+       expect_void(';');
 }
 
-typedef struct declaration_t declaration_t;
-struct declaration_t {
-       declaration_specifiers_t  specifiers;
-       declaration_t            *declarators;
-};
+static
+void parse_struct_declarators(const declaration_specifiers_t *specifiers)
+{
+       while(1) {
+               if(token.type == ':') {
+                       next_token();
+                       parse_constant_expression();
+                       /* TODO (bitfields) */
+               } else {
+                       declaration_t *declaration
+                               = allocate_ast_zero(sizeof(declaration[0]));
+                       parse_declarator(declaration, specifiers->storage_class,
+                                        specifiers->type, 0);
+                       maybe_push_declaration(declaration);
+                       record_declaration(declaration);
+
+                       if(token.type == ':') {
+                               next_token();
+                               parse_constant_expression();
+                               /* TODO (bitfields) */
+                       }
+               }
+
+               if(token.type != ',')
+                       break;
+               next_token();
+       }
+       expect_void(';');
+}
+
+static void parse_compound_type_entries(void)
+{
+       eat('{');
+
+       while(token.type != '}' && token.type != T_EOF) {
+               declaration_specifiers_t specifiers;
+               memset(&specifiers, 0, sizeof(specifiers));
+               /* TODO not correct as this allows storage class stuff... but only
+                * specifiers and qualifiers sould be allowed here */
+               parse_declaration_specifiers(&specifiers);
+
+               parse_struct_declarators(&specifiers);
+       }
+       if(token.type == T_EOF) {
+               parse_error("unexpected error while parsing struct");
+       }
+       next_token();
+}
 
 void parse_declaration(void)
 {
@@ -417,24 +1233,28 @@ void parse_declaration(void)
        memset(&specifiers, 0, sizeof(specifiers));
        parse_declaration_specifiers(&specifiers);
 
+       if(token.type == ';') {
+               next_token();
+               return;
+       }
        parse_init_declarators(&specifiers);
 }
 
-#if 0
-namespace_t *parse(FILE *in, const char *input_name)
+type_t *parse_typename(void)
 {
-       namespace_t *namespace = parse_namespace();
+       declaration_specifiers_t specifiers;
+       memset(&specifiers, 0, sizeof(specifiers));
+       /* TODO not correct storage class elements are not allowed here */
+       parse_declaration_specifiers(&specifiers);
 
-       return namespace;
+       int pointers = parse_pointers();
+       specifiers.type = make_pointers(specifiers.type, pointers);
+
+       return specifiers.type;
 }
-#endif
 
 
 
-static
-expression_t *parse_sub_expression(unsigned precedence);
-static
-expression_t *parse_expression(void);
 
 typedef expression_t* (*parse_expression_function) (unsigned precedence);
 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
@@ -557,14 +1377,33 @@ expression_t *parse_array_expression(unsigned precedence,
        return (expression_t*) array_access;
 }
 
+static
+type_t *get_expression_type(const expression_t *expression)
+{
+       (void) expression;
+       /* TODO */
+       return NULL;
+}
+
 static
 expression_t *parse_sizeof(unsigned precedence)
 {
-       (void) precedence;
        eat(T_sizeof);
-       /* TODO... */
 
-       return NULL;
+       sizeof_expression_t *sizeof_expression
+               = allocate_ast_zero(sizeof(sizeof_expression[0]));
+       sizeof_expression->expression.type = EXPR_SIZEOF;
+
+       if(token.type == '(' /* && LA1 is type_specifier */) {
+               next_token();
+               sizeof_expression->type = parse_typename();
+               expect(')');
+       } else {
+               expression_t *expression = parse_sub_expression(precedence);
+               sizeof_expression->type  = get_expression_type(expression);
+       }
+
+       return (expression_t*) sizeof_expression;
 }
 
 static
@@ -644,14 +1483,14 @@ expression_t *parse_##unexpression_type(unsigned precedence)              \
        return (expression_t*) unary_expression;                              \
 }
 
-CREATE_UNARY_EXPRESSION_PARSER('-', UNEXPR_NEGATE);
-CREATE_UNARY_EXPRESSION_PARSER('+', UNEXPR_PLUS);
-CREATE_UNARY_EXPRESSION_PARSER('!', UNEXPR_NOT);
-CREATE_UNARY_EXPRESSION_PARSER('*', UNEXPR_DEREFERENCE);
-CREATE_UNARY_EXPRESSION_PARSER('&', UNEXPR_TAKE_ADDRESS);
-CREATE_UNARY_EXPRESSION_PARSER('~', UNEXPR_BITWISE_NEGATE);
-CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_PREFIX_INCREMENT);
-CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_PREFIX_DECREMENT);
+CREATE_UNARY_EXPRESSION_PARSER('-', UNEXPR_NEGATE)
+CREATE_UNARY_EXPRESSION_PARSER('+', UNEXPR_PLUS)
+CREATE_UNARY_EXPRESSION_PARSER('!', UNEXPR_NOT)
+CREATE_UNARY_EXPRESSION_PARSER('*', UNEXPR_DEREFERENCE)
+CREATE_UNARY_EXPRESSION_PARSER('&', UNEXPR_TAKE_ADDRESS)
+CREATE_UNARY_EXPRESSION_PARSER('~', UNEXPR_BITWISE_NEGATE)
+CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_PREFIX_INCREMENT)
+CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_PREFIX_DECREMENT)
 
 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type) \
 static                                                                        \
@@ -670,8 +1509,8 @@ expression_t *parse_##unexpression_type(unsigned precedence,                  \
        return (expression_t*) unary_expression;                                  \
 }
 
-CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_POSTFIX_INCREMENT);
-CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT);
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_POSTFIX_INCREMENT)
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT)
 
 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type)    \
 static                                                           \
@@ -692,22 +1531,22 @@ expression_t *parse_##binexpression_type(unsigned precedence,    \
        return (expression_t*) binexpr;                              \
 }
 
-CREATE_BINEXPR_PARSER('*', BINEXPR_MUL);
-CREATE_BINEXPR_PARSER('/', BINEXPR_DIV);
-CREATE_BINEXPR_PARSER('+', BINEXPR_ADD);
-CREATE_BINEXPR_PARSER('-', BINEXPR_SUB);
-CREATE_BINEXPR_PARSER('<', BINEXPR_LESS);
-CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER);
-CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN);
-CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL);
-CREATE_BINEXPR_PARSER(T_SLASHEQUAL, BINEXPR_NOTEQUAL);
-CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL);
-CREATE_BINEXPR_PARSER(T_GREATEREQUAL, BINEXPR_GREATEREQUAL);
-CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND);
-CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR);
-CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR);
-CREATE_BINEXPR_PARSER(T_LESSLESS, BINEXPR_SHIFTLEFT);
-CREATE_BINEXPR_PARSER(T_GREATERGREATER, BINEXPR_SHIFTRIGHT);
+CREATE_BINEXPR_PARSER('*', BINEXPR_MUL)
+CREATE_BINEXPR_PARSER('/', BINEXPR_DIV)
+CREATE_BINEXPR_PARSER('+', BINEXPR_ADD)
+CREATE_BINEXPR_PARSER('-', BINEXPR_SUB)
+CREATE_BINEXPR_PARSER('<', BINEXPR_LESS)
+CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER)
+CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN)
+CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL)
+CREATE_BINEXPR_PARSER(T_SLASHEQUAL, BINEXPR_NOTEQUAL)
+CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL)
+CREATE_BINEXPR_PARSER(T_GREATEREQUAL, BINEXPR_GREATEREQUAL)
+CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND)
+CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR)
+CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR)
+CREATE_BINEXPR_PARSER(T_LESSLESS, BINEXPR_SHIFTLEFT)
+CREATE_BINEXPR_PARSER(T_GREATERGREATER, BINEXPR_SHIFTRIGHT)
 
 static
 expression_t *parse_sub_expression(unsigned precedence)
@@ -718,7 +1557,7 @@ expression_t *parse_sub_expression(unsigned precedence)
 
        expression_parser_function_t *parser
                = &expression_parsers[token.type];
-       source_position_t             source_position = source_position;
+       source_position_t             source_position = token.source_position;
        expression_t                 *left;
 
        if(parser->parser != NULL) {
@@ -834,12 +1673,6 @@ void init_expression_parsers(void)
 }
 
 
-static
-statement_t *parse_compound_statement(void);
-
-static
-statement_t *parse_statement(void);
-
 static
 statement_t *parse_case_statement(void)
 {
@@ -865,7 +1698,7 @@ static
 statement_t *parse_label_statement(void)
 {
        eat(T_IDENTIFIER);
-       expect(';');
+       expect(':');
        parse_statement();
 
        return NULL;
@@ -986,10 +1819,25 @@ statement_t *parse_return(void)
        return NULL;
 }
 
+static
+statement_t *parse_declaration_statement(void)
+{
+       parse_declaration();
+       return NULL;
+}
+
+static
+statement_t *parse_expression_statement(void)
+{
+       parse_expression();
+       return NULL;
+}
+
 static
 statement_t *parse_statement(void)
 {
-       statement_t *statement = NULL;
+       declaration_t *declaration;
+       statement_t   *statement = NULL;
 
        /* declaration or statement */
        switch(token.type) {
@@ -1001,10 +1849,6 @@ statement_t *parse_statement(void)
                statement = parse_default_statement();
                break;
 
-       case T_IDENTIFIER:
-               statement = parse_label_statement();
-               break;
-
        case '{':
                statement = parse_compound_statement();
                break;
@@ -1048,6 +1892,26 @@ statement_t *parse_statement(void)
        case ';':
                statement = NULL;
                break;
+
+       case T_IDENTIFIER:
+               if(la(1)->type == ':') {
+                       statement = parse_label_statement();
+                       break;
+               }
+
+               declaration = token.v.symbol->declaration;
+               if(declaration != NULL &&
+                               declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
+                       statement = parse_declaration_statement();
+                       break;
+               }
+
+               statement = parse_expression_statement();
+               break;
+
+       DECLARATION_START
+               statement = parse_declaration_statement();
+               break;
        }
 
        return statement;
@@ -1056,53 +1920,72 @@ statement_t *parse_statement(void)
 static
 statement_t *parse_compound_statement(void)
 {
-       expect('{');
+       eat('{');
+
+       compound_statement_t *compound_statement
+               = allocate_ast_zero(sizeof(compound_statement[0]));
+       compound_statement->statement.type = STATEMENT_COMPOUND;
+
+       int        top          = environment_top();
+       context_t *last_context = context;
+       set_context(&compound_statement->context);
 
        while(token.type != '}') {
                parse_statement();
        }
+
+       assert(context == &compound_statement->context);
+       set_context(last_context);
+       environment_pop_to(top);
+
        next_token();
 
-       return NULL;
+       return (statement_t*) compound_statement;
 }
 
 static
-void parse_translation_unit(void)
+translation_unit_t *parse_translation_unit(void)
 {
-       declaration_specifiers_t specifiers;
-       memset(&specifiers, 0, sizeof(specifiers));
-       parse_declaration_specifiers(&specifiers);
+       translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
 
-       while(token.type != T_EOF) {
-               if(token.type == '{') {
-                       next_token();
-                       continue;
-               }
+       assert(context == NULL);
+       set_context(&unit->context);
 
+       while(token.type != T_EOF) {
                parse_declaration();
-               /* multiple declarations? */
-
-               if(token.type == '{') {
-                       parse_compound_statement();
-               } else if(token.type == ';') {
-                       next_token();
-               } else {
-                       parse_error_expected("while parsing declarations", '{', ';', 0);
-               }
        }
+
+       assert(context == &unit->context);
+       context          = NULL;
+       last_declaration = NULL;
+
+       return unit;
 }
 
-void parse(void)
+translation_unit_t *parse(void)
 {
-       next_token();
-       parse_translation_unit();
+       obstack_init(&environment_obstack);
+       environment_stack = NEW_ARR_F(environment_entry_t*, 0);
+
+       lookahead_bufpos = 0;
+       for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
+               next_token();
+       }
+       translation_unit_t *unit = parse_translation_unit();
+
+       DEL_ARR_F(environment_stack);
+       obstack_free(&environment_obstack, NULL);
+
+       return unit;
 }
 
 void init_parser(void)
 {
        init_expression_parsers();
+       obstack_init(&temp_obst);
 }
 
 void exit_parser(void)
 {
+       obstack_free(&temp_obst, NULL);
 }