fix a few segfaults
[cparser] / parser.c
index 19b00c0..f63c266 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -25,6 +25,16 @@ typedef struct {
        unsigned short namespc;
 } stack_entry_t;
 
+typedef struct declaration_specifiers_t  declaration_specifiers_t;
+struct declaration_specifiers_t {
+       source_position_t  source_position;
+       unsigned char      storage_class;
+       bool               is_inline;
+       type_t            *type;
+};
+
+typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration);
+
 static token_t         token;
 static token_t         lookahead_buffer[MAX_LOOKAHEAD];
 static int             lookahead_bufpos;
@@ -45,8 +55,12 @@ static type_t         *type_char        = NULL;
 static type_t         *type_string      = NULL;
 static type_t         *type_void        = NULL;
 static type_t         *type_void_ptr    = NULL;
-static type_t         *type_size_t      = NULL;
-static type_t         *type_ptrdiff_t   = NULL;
+static type_t         *type_valist      = NULL;
+
+type_t *type_size_t      = NULL;
+type_t *type_ptrdiff_t   = NULL;
+type_t *type_wchar_t     = NULL;
+type_t *type_wchar_t_ptr = NULL;
 
 static statement_t *parse_compound_statement(void);
 static statement_t *parse_statement(void);
@@ -55,6 +69,13 @@ static expression_t *parse_sub_expression(unsigned precedence);
 static expression_t *parse_expression(void);
 static type_t       *parse_typename(void);
 
+static void parse_compound_type_entries(void);
+static declaration_t *parse_declarator(
+               const declaration_specifiers_t *specifiers, bool may_be_abstract);
+static declaration_t *record_declaration(declaration_t *declaration);
+
+static void semantic_comparison(binary_expression_t *expression);
+
 #define STORAGE_CLASSES     \
        case T_typedef:         \
        case T_extern:          \
@@ -78,22 +99,23 @@ static type_t       *parse_typename(void);
 #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:            \
-       case T___typeof__:      \
-       COMPLEX_SPECIFIERS      \
+#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:              \
+       case T___typeof__:        \
+       case T___builtin_va_list: \
+       COMPLEX_SPECIFIERS        \
        IMAGINARY_SPECIFIERS
 
 #define DECLARATION_START   \
@@ -112,34 +134,84 @@ static void *allocate_ast_zero(size_t size)
        return res;
 }
 
+static size_t get_statement_struct_size(statement_type_t type)
+{
+       static const size_t sizes[] = {
+               [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
+               [STATEMENT_RETURN]      = sizeof(return_statement_t),
+               [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
+               [STATEMENT_IF]          = sizeof(if_statement_t),
+               [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
+               [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
+               [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
+               [STATEMENT_BREAK]       = sizeof(statement_base_t),
+               [STATEMENT_GOTO]        = sizeof(goto_statement_t),
+               [STATEMENT_LABEL]       = sizeof(label_statement_t),
+               [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
+               [STATEMENT_WHILE]       = sizeof(while_statement_t),
+               [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
+               [STATEMENT_FOR]         = sizeof(for_statement_t),
+               [STATEMENT_ASM]         = sizeof(asm_statement_t)
+       };
+       assert(type <= sizeof(sizes) / sizeof(sizes[0]));
+       assert(sizes[type] != 0);
+       return sizes[type];
+}
+
+static statement_t *allocate_statement_zero(statement_type_t type)
+{
+       size_t       size = get_statement_struct_size(type);
+       statement_t *res  = allocate_ast_zero(size);
+
+       res->base.type = type;
+       return res;
+}
+
+
 static size_t get_expression_struct_size(expression_type_t type)
 {
        static const size_t sizes[] = {
-               [EXPR_REFERENCE]       = sizeof(reference_expression_t),
-               [EXPR_CONST]           = sizeof(const_expression_t),
-               [EXPR_STRING_LITERAL]  = sizeof(string_literal_expression_t),
-               [EXPR_CALL]            = sizeof(call_expression_t),
-               [EXPR_UNARY]           = sizeof(unary_expression_t),
-               [EXPR_BINARY]          = sizeof(binary_expression_t),
-               [EXPR_CONDITIONAL]     = sizeof(conditional_expression_t),
-               [EXPR_SELECT]          = sizeof(select_expression_t),
-               [EXPR_ARRAY_ACCESS]    = sizeof(array_access_expression_t),
-               [EXPR_SIZEOF]          = sizeof(sizeof_expression_t),
-               [EXPR_CLASSIFY_TYPE]   = sizeof(classify_type_expression_t),
-               [EXPR_FUNCTION]        = sizeof(string_literal_expression_t),
-               [EXPR_PRETTY_FUNCTION] = sizeof(string_literal_expression_t),
-               [EXPR_BUILTIN_SYMBOL]  = sizeof(builtin_symbol_expression_t),
-               [EXPR_OFFSETOF]        = sizeof(offsetof_expression_t),
-               [EXPR_VA_ARG]          = sizeof(va_arg_expression_t),
-               [EXPR_STATEMENT]       = sizeof(statement_expression_t)
+               [EXPR_INVALID]             = sizeof(expression_base_t),
+               [EXPR_REFERENCE]           = sizeof(reference_expression_t),
+               [EXPR_CONST]               = sizeof(const_expression_t),
+               [EXPR_STRING_LITERAL]      = sizeof(string_literal_expression_t),
+               [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
+               [EXPR_CALL]                = sizeof(call_expression_t),
+               [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
+               [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
+               [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
+               [EXPR_SELECT]              = sizeof(select_expression_t),
+               [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
+               [EXPR_SIZEOF]              = sizeof(sizeof_expression_t),
+               [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
+               [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
+               [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
+               [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
+               [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
+               [EXPR_VA_START]            = sizeof(va_start_expression_t),
+               [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
+               [EXPR_STATEMENT]           = sizeof(statement_expression_t),
        };
-       assert(sizeof(sizes) / sizeof(sizes[0]) == EXPR_STATEMENT + 1);
-       assert(type <= EXPR_STATEMENT);
+       if(type >= EXPR_UNARY_FIRST && type <= EXPR_UNARY_LAST) {
+               return sizes[EXPR_UNARY_FIRST];
+       }
+       if(type >= EXPR_BINARY_FIRST && type <= EXPR_BINARY_LAST) {
+               return sizes[EXPR_BINARY_FIRST];
+       }
+       assert(type <= sizeof(sizes) / sizeof(sizes[0]));
        assert(sizes[type] != 0);
-       (void) get_expression_struct_size;
        return sizes[type];
 }
 
+static expression_t *allocate_expression_zero(expression_type_t type)
+{
+       size_t        size = get_expression_struct_size(type);
+       expression_t *res  = allocate_ast_zero(size);
+
+       res->base.type = type;
+       return res;
+}
+
 static size_t get_type_struct_size(type_type_t type)
 {
        static const size_t sizes[] = {
@@ -173,11 +245,12 @@ static type_t *allocate_type_zero(type_type_t type)
 static size_t get_initializer_size(initializer_type_t type)
 {
        static const size_t sizes[] = {
-               [INITIALIZER_VALUE]  = sizeof(initializer_value_t),
-               [INITIALIZER_STRING] = sizeof(initializer_string_t),
-               [INITIALIZER_LIST]   = sizeof(initializer_list_t)
+               [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
+               [INITIALIZER_STRING]      = sizeof(initializer_string_t),
+               [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
+               [INITIALIZER_LIST]        = sizeof(initializer_list_t)
        };
-       assert(type < INITIALIZER_COUNT);
+       assert(type < sizeof(sizes) / sizeof(*sizes));
        assert(sizes[type] != 0);
        return sizes[type];
 }
@@ -228,7 +301,7 @@ static inline const token_t *look_ahead(int num)
 {
        assert(num > 0 && num <= MAX_LOOKAHEAD);
        int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
-       return & lookahead_buffer[pos];
+       return &lookahead_buffer[pos];
 }
 
 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
@@ -275,6 +348,11 @@ static void parser_print_warning_prefix_pos(
        fputs("warning: ", stderr);
 }
 
+static void parser_print_warning_prefix(void)
+{
+       parser_print_warning_prefix_pos(token.source_position);
+}
+
 static void parse_warning_pos(const source_position_t source_position,
                               const char *const message)
 {
@@ -376,7 +454,7 @@ static void eat_statement(void)
        eat(';');
 }
 
-static void eat_brace(void)
+static void eat_paren(void)
 {
        if(token.type == '(')
                next_token();
@@ -388,7 +466,7 @@ static void eat_brace(void)
                        return;
                }
                if(token.type == '(') {
-                       eat_brace();
+                       eat_paren();
                        continue;
                }
                if(token.type == '{') {
@@ -440,22 +518,19 @@ static void set_context(context_t *new_context)
  * called when we find a 2nd declarator for an identifier we already have a
  * declarator for
  */
-static bool is_compatible_declaration (declaration_t *declaration,
+static bool is_compatible_declaration(declaration_t *declaration,
                                       declaration_t *previous)
 {
-       if (declaration->type->type == TYPE_FUNCTION &&
-                       previous->type->type    == TYPE_FUNCTION &&
-                       previous->type->function.unspecified_parameters) {
-               function_type_t* const prev_func = &previous->type->function;
-               function_type_t* const decl_func = &declaration->type->function;
-               if (prev_func->unspecified_parameters &&
-                               prev_func->result_type == decl_func->result_type) {
-                       declaration->type = previous->type;
-                       return true;
-               }
+       /* happens for K&R style function parameters */
+       if(previous->type == NULL) {
+               previous->type = declaration->type;
+               return true;
        }
-       /* TODO: not correct yet */
-       return declaration->type == previous->type;
+
+       type_t *type1 = skip_typeref(declaration->type);
+       type_t *type2 = skip_typeref(previous->type);
+
+       return types_compatible(type1, type2);
 }
 
 static declaration_t *get_declaration(symbol_t *symbol, namespace_t namespc)
@@ -498,7 +573,6 @@ static declaration_t *stack_push(stack_entry_t **stack_ptr,
        namespace_t  namespc = (namespace_t)declaration->namespc;
 
        /* a declaration should be only pushed once */
-       assert(declaration->parent_context == NULL);
        declaration->parent_context = parent_context;
 
        declaration_t *previous_declaration = get_declaration(symbol, namespc);
@@ -507,7 +581,7 @@ static declaration_t *stack_push(stack_entry_t **stack_ptr,
                        && previous_declaration->parent_context == context) {
                if(!is_compatible_declaration(declaration, previous_declaration)) {
                        parser_print_error_prefix_pos(declaration->source_position);
-                       fprintf(stderr, "definition of symbol %s%s with type ",
+                       fprintf(stderr, "definition of symbol '%s%s' with type ",
                                        get_namespace_prefix(namespc), symbol->string);
                        print_type_quoted(declaration->type);
                        fputc('\n', stderr);
@@ -628,7 +702,7 @@ static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
                return;
 
        for(i = top; i > new_top; --i) {
-               stack_entry_t *entry = & stack[i - 1];
+               stack_entry_t *entry = &stack[i - 1];
 
                declaration_t *old_declaration = entry->old_declaration;
                symbol_t      *symbol          = entry->symbol;
@@ -675,6 +749,7 @@ static void label_pop_to(size_t new_top)
 
 static int get_rank(const type_t *type)
 {
+       assert(!is_typeref(type));
        /* The C-standard allows promoting to int or unsigned int (see ยง 7.2.2
         * and esp. footnote 108). However we can't fold constants (yet), so we
         * can't decide wether unsigned int is possible, while int always works.
@@ -700,18 +775,24 @@ static type_t *promote_integer(type_t *type)
 static expression_t *create_cast_expression(expression_t *expression,
                                             type_t *dest_type)
 {
-       unary_expression_t *cast = allocate_ast_zero(sizeof(cast[0]));
+       expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 
-       cast->expression.type     = EXPR_UNARY;
-       cast->type                = UNEXPR_CAST;
-       cast->value               = expression;
-       cast->expression.datatype = dest_type;
+       cast->unary.value   = expression;
+       cast->base.datatype = dest_type;
 
-       return (expression_t*) cast;
+       return cast;
 }
 
-static bool is_null_expression(const expression_t *const expression)
+static bool is_null_pointer_constant(const expression_t *expression)
 {
+       /* skip void* cast */
+       if(expression->type == EXPR_UNARY_CAST
+                       || expression->type == EXPR_UNARY_CAST_IMPLICIT) {
+               expression = expression->unary.value;
+       }
+
+       /* TODO: not correct yet, should be any constant integer expression
+        * which evaluates to 0 */
        if (expression->type != EXPR_CONST)
                return false;
 
@@ -757,7 +838,7 @@ static expression_t *create_implicit_cast(expression_t *expression,
                case TYPE_POINTER:
                        switch (source_type->type) {
                                case TYPE_ATOMIC:
-                                       if (is_null_expression(expression)) {
+                                       if (is_null_pointer_constant(expression)) {
                                                return create_cast_expression(expression, dest_type);
                                        }
                                        break;
@@ -804,7 +885,7 @@ static void semantic_assign(type_t *orig_type_left, expression_t **right,
        type_t *const type_right = skip_typeref(orig_type_right);
 
        if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
-           (is_type_pointer(type_left) && is_null_expression(*right)) ||
+           (is_type_pointer(type_left) && is_null_pointer_constant(*right)) ||
            (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
                && is_type_pointer(type_right))) {
                *right = create_implicit_cast(*right, type_left);
@@ -820,12 +901,6 @@ static void semantic_assign(type_t *orig_type_left, expression_t **right,
                points_to_left  = skip_typeref(points_to_left);
                points_to_right = skip_typeref(points_to_right);
 
-               if(!is_type_atomic(points_to_left, ATOMIC_TYPE_VOID)
-                               && !is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)
-                               && !types_compatible(points_to_left, points_to_right)) {
-                       goto incompatible_assign_types;
-               }
-
                /* the left type has all qualifiers from the right type */
                unsigned missing_qualifiers
                        = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
@@ -841,6 +916,15 @@ static void semantic_assign(type_t *orig_type_left, expression_t **right,
                        return;
                }
 
+               points_to_left  = get_unqualified_type(points_to_left);
+               points_to_right = get_unqualified_type(points_to_right);
+
+               if(!is_type_atomic(points_to_left, ATOMIC_TYPE_VOID)
+                               && !is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)
+                               && !types_compatible(points_to_left, points_to_right)) {
+                       goto incompatible_assign_types;
+               }
+
                *right = create_implicit_cast(*right, type_left);
                return;
        }
@@ -856,9 +940,9 @@ incompatible_assign_types:
        parser_print_error_prefix();
        fprintf(stderr, "incompatible types in %s\n", context);
        parser_print_error_prefix();
-       print_type_quoted(type_left);
+       print_type_quoted(orig_type_left);
        fputs(" <- ", stderr);
-       print_type_quoted(type_right);
+       print_type_quoted(orig_type_right);
        fputs("\n", stderr);
 }
 
@@ -874,18 +958,24 @@ static expression_t *parse_assignment_expression(void)
        return parse_sub_expression(2);
 }
 
-typedef struct declaration_specifiers_t  declaration_specifiers_t;
-struct declaration_specifiers_t {
-       unsigned char storage_class;
-       bool          is_inline;
-       type_t       *type;
-};
+static type_t *make_global_typedef(const char *name, type_t *type)
+{
+       symbol_t *symbol       = symbol_table_insert(name);
 
-static void parse_compound_type_entries(void);
-static declaration_t *parse_declarator(
-               const declaration_specifiers_t *specifiers, type_t *type,
-               bool may_be_abstract);
-static declaration_t *record_declaration(declaration_t *declaration);
+       declaration_t *declaration   = allocate_ast_zero(sizeof(declaration[0]));
+       declaration->namespc         = NAMESPACE_NORMAL;
+       declaration->storage_class   = STORAGE_CLASS_TYPEDEF;
+       declaration->type            = type;
+       declaration->symbol          = symbol;
+       declaration->source_position = builtin_source_position;
+
+       record_declaration(declaration);
+
+       type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
+       typedef_type->typedeft.declaration = declaration;
+
+       return typedef_type;
+}
 
 static const char *parse_string_literals(void)
 {
@@ -936,7 +1026,7 @@ static void parse_attributes(void)
                        if(token.type != T_STRING_LITERAL) {
                                parse_error_expected("while parsing assembler attribute",
                                                     T_STRING_LITERAL);
-                               eat_brace();
+                               eat_paren();
                                break;
                        } else {
                                parse_string_literals();
@@ -1009,38 +1099,62 @@ static initializer_t *initializer_from_string(array_type_t *type,
        return initializer;
 }
 
+static initializer_t *initializer_from_wide_string(array_type_t *const type,
+                                                   wide_string_t *const string)
+{
+       /* TODO: check len vs. size of array type */
+       (void) type;
+
+       initializer_t *const initializer =
+               allocate_initializer(INITIALIZER_WIDE_STRING);
+       initializer->wide_string.string = *string;
+
+       return initializer;
+}
+
 static initializer_t *initializer_from_expression(type_t *type,
                                                   expression_t *expression)
 {
        /* TODO check that expression is a constant expression */
 
        /* ยง 6.7.8.14/15 char array may be initialized by string literals */
-       if(type->type == TYPE_ARRAY && expression->type == EXPR_STRING_LITERAL) {
-               array_type_t *array_type   = &type->array;
-               type_t       *element_type = array_type->element_type;
-
-               if(element_type->type == TYPE_ATOMIC) {
-                       atomic_type_t      *atomic_type = &element_type->atomic;
-                       atomic_type_type_t  atype       = atomic_type->atype;
+       type_t *const expr_type = expression->base.datatype;
+       if (is_type_array(type) && expr_type->type == TYPE_POINTER) {
+               array_type_t *const array_type     = &type->array;
+               type_t       *const element_type   = skip_typeref(array_type->element_type);
+
+               if (element_type->type == TYPE_ATOMIC) {
+                       switch (expression->type) {
+                               case EXPR_STRING_LITERAL:
+                                       if (element_type->atomic.atype == ATOMIC_TYPE_CHAR) {
+                                               return initializer_from_string(array_type,
+                                                       expression->string.value);
+                                       }
 
-                       /* TODO handle wide strings */
-                       if(atype == ATOMIC_TYPE_CHAR
-                                       || atype == ATOMIC_TYPE_SCHAR
-                                       || atype == ATOMIC_TYPE_UCHAR) {
+                               case EXPR_WIDE_STRING_LITERAL: {
+                                       type_t *bare_wchar_type = skip_typeref(type_wchar_t);
+                                       if (get_unqualified_type(element_type) == bare_wchar_type) {
+                                               return initializer_from_wide_string(array_type,
+                                                       &expression->wide_string.value);
+                                       }
+                               }
 
-                               string_literal_expression_t *literal
-                                       = &expression->string_literal;
-                               return initializer_from_string(array_type, literal->value);
+                               default: break;
                        }
                }
        }
 
-       semantic_assign(type, &expression, "initializer");
+       type_t *expression_type = skip_typeref(expression->base.datatype);
+       if(is_type_scalar(type) || types_compatible(type, expression_type)) {
+               semantic_assign(type, &expression, "initializer");
+
+               initializer_t *result = allocate_initializer(INITIALIZER_VALUE);
+               result->value.value   = expression;
 
-       initializer_t *result = allocate_initializer(INITIALIZER_VALUE);
-       result->value.value   = expression;
+               return result;
+       }
 
-       return result;
+       return NULL;
 }
 
 static initializer_t *parse_sub_initializer(type_t *type,
@@ -1088,17 +1202,11 @@ static initializer_t *parse_sub_initializer(type_t *type,
                return initializer_from_expression(type, expression);
        }
 
-       /* TODO: ignore qualifiers, comparing pointers is probably
-        * not correct */
-       if(expression != NULL && expression_type == type) {
-               initializer_t *result = allocate_initializer(INITIALIZER_VALUE);
-
-               if(type != NULL) {
-                       semantic_assign(type, &expression, "initializer");
-               }
-               result->value.value = expression;
-
-               return result;
+       /* does the expression match the currently looked at object to initalize */
+       if(expression != NULL) {
+               initializer_t *result = initializer_from_expression(type, expression);
+               if(result != NULL)
+                       return result;
        }
 
        bool read_paren = false;
@@ -1110,7 +1218,7 @@ static initializer_t *parse_sub_initializer(type_t *type,
        /* descend into subtype */
        initializer_t  *result = NULL;
        initializer_t **elems;
-       if(type->type == TYPE_ARRAY) {
+       if(is_type_array(type)) {
                array_type_t *array_type   = &type->array;
                type_t       *element_type = array_type->element_type;
                element_type               = skip_typeref(element_type);
@@ -1140,7 +1248,7 @@ static initializer_t *parse_sub_initializer(type_t *type,
                        if(token.type == '}')
                                break;
 
-                       sub = parse_sub_initializer(element_type, NULL, NULL);
+                       sub = parse_sub_initializer_elem(element_type);
                        if(sub == NULL) {
                                /* TODO error, do nicer cleanup */
                                parse_error("member initializer didn't match");
@@ -1150,10 +1258,9 @@ static initializer_t *parse_sub_initializer(type_t *type,
                        ARR_APP1(initializer_t*, elems, sub);
                }
        } else {
-               assert(type->type == TYPE_COMPOUND_STRUCT
-                               || type->type == TYPE_COMPOUND_UNION);
+               assert(is_type_compound(type));
                compound_type_t *compound_type = &type->compound;
-               context_t       *context       = & compound_type->declaration->context;
+               context_t       *context       = &compound_type->declaration->context;
 
                declaration_t *first = context->declarations;
                if(first == NULL)
@@ -1194,7 +1301,7 @@ static initializer_t *parse_sub_initializer(type_t *type,
                        type_t *iter_type = iter->type;
                        iter_type         = skip_typeref(iter_type);
 
-                       sub = parse_sub_initializer(iter_type, NULL, NULL);
+                       sub = parse_sub_initializer_elem(iter_type);
                        if(sub == NULL) {
                                /* TODO error, do nicer cleanup*/
                                parse_error("member initializer didn't match");
@@ -1232,8 +1339,19 @@ static initializer_t *parse_initializer(type_t *type)
        type = skip_typeref(type);
 
        if(token.type != '{') {
-               expression_t *expression = parse_assignment_expression();
-               return initializer_from_expression(type, expression);
+               expression_t  *expression  = parse_assignment_expression();
+               initializer_t *initializer = initializer_from_expression(type, expression);
+               if(initializer == NULL) {
+                       parser_print_error_prefix();
+                       fprintf(stderr, "initializer expression '");
+                       print_expression(expression);
+                       fprintf(stderr, "', type ");
+                       print_type_quoted(expression->base.datatype);
+                       fprintf(stderr, " is incompatible with type ");
+                       print_type_quoted(type);
+                       fprintf(stderr, "\n");
+               }
+               return initializer;
        }
 
        if(is_type_scalar(type)) {
@@ -1319,12 +1437,12 @@ static declaration_t *parse_compound_type_specifier(bool is_struct)
 
                int         top          = environment_top();
                context_t  *last_context = context;
-               set_context(& declaration->context);
+               set_context(&declaration->context);
 
                parse_compound_type_entries();
                parse_attributes();
 
-               assert(context == & declaration->context);
+               assert(context == &declaration->context);
                set_context(last_context);
                environment_pop_to(top);
        }
@@ -1499,14 +1617,19 @@ typedef enum {
 #endif
 } specifiers_t;
 
-static type_t *create_builtin_type(symbol_t *symbol)
+static type_t *create_builtin_type(symbol_t *const symbol,
+                                   type_t *const real_type)
 {
        type_t *type            = allocate_type_zero(TYPE_BUILTIN);
        type->builtin.symbol    = symbol;
-       /* TODO... */
-       type->builtin.real_type = type_int;
+       type->builtin.real_type = real_type;
 
-       return type;
+       type_t *result = typehash_insert(type);
+       if (type != result) {
+               free_type(type);
+       }
+
+       return result;
 }
 
 static type_t *get_typedef_type(symbol_t *symbol)
@@ -1529,6 +1652,8 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
        unsigned  type_specifiers = 0;
        int       newtype         = 0;
 
+       specifiers->source_position = token.source_position;
+
        while(true) {
                switch(token.type) {
 
@@ -1549,6 +1674,27 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
                MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
 
+               case T___thread:
+                       switch (specifiers->storage_class) {
+                               case STORAGE_CLASS_NONE:
+                                       specifiers->storage_class = STORAGE_CLASS_THREAD;
+                                       break;
+
+                               case STORAGE_CLASS_EXTERN:
+                                       specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
+                                       break;
+
+                               case STORAGE_CLASS_STATIC:
+                                       specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
+                                       break;
+
+                               default:
+                                       parse_error("multiple storage classes in declaration specifiers");
+                                       break;
+                       }
+                       next_token();
+                       break;
+
                /* type qualifiers */
 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
                case token:                                                     \
@@ -1626,7 +1772,7 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                        type = parse_typeof();
                        break;
                case T___builtin_va_list:
-                       type = create_builtin_type(token.v.symbol);
+                       type = duplicate_type(type_valist);
                        next_token();
                        break;
 
@@ -1748,7 +1894,7 @@ finish_specifiers:
                        /* invalid specifier combination, give an error message */
                        if(type_specifiers == 0) {
 #ifndef STRICT_C99
-                               parse_warning("no type specifiers in declaration (using int)");
+                               parse_warning("no type specifiers in declaration, using int");
                                atomic_type = ATOMIC_TYPE_INT;
                                break;
 #else
@@ -1801,18 +1947,65 @@ static type_qualifiers_t parse_type_qualifiers(void)
        }
 }
 
-static void parse_identifier_list(void)
+static declaration_t *parse_identifier_list(void)
 {
-       while(true) {
-               if(token.type != T_IDENTIFIER) {
-                       parse_error_expected("while parsing parameter identifier list",
-                                            T_IDENTIFIER, 0);
-                       return;
-               }
+       declaration_t *declarations     = NULL;
+       declaration_t *last_declaration = NULL;
+       do {
+               declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
+
+               declaration->source_position = token.source_position;
+               declaration->symbol          = token.v.symbol;
                next_token();
+
+               if(last_declaration != NULL) {
+                       last_declaration->next = declaration;
+               } else {
+                       declarations = declaration;
+               }
+               last_declaration = declaration;
+
                if(token.type != ',')
                        break;
                next_token();
+       } while(token.type == T_IDENTIFIER);
+
+       return declarations;
+}
+
+static void semantic_parameter(declaration_t *declaration)
+{
+       /* TODO: improve error messages */
+
+       if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
+               parse_error("typedef not allowed in parameter list");
+       } else if(declaration->storage_class != STORAGE_CLASS_NONE
+                       && declaration->storage_class != STORAGE_CLASS_REGISTER) {
+               parse_error("parameter may only have none or register storage class");
+       }
+
+       type_t *orig_type = declaration->type;
+       if(orig_type == NULL)
+               return;
+       type_t *type = skip_typeref(orig_type);
+
+       /* Array as last part of a paramter type is just syntactic sugar.  Turn it
+        * into a pointer. ยง 6.7.5.3 (7) */
+       if (is_type_array(type)) {
+               const array_type_t *arr_type     = &type->array;
+               type_t             *element_type = arr_type->element_type;
+
+               type = make_pointer_type(element_type, type->base.qualifiers);
+
+               declaration->type = type;
+       }
+
+       if(is_type_incomplete(type)) {
+               parser_print_error_prefix();
+               fprintf(stderr, "incomplete type (");
+               print_type_quoted(orig_type);
+               fprintf(stderr, ") not allowed for parameter '%s'\n",
+                       declaration->symbol->string);
        }
 }
 
@@ -1823,21 +2016,9 @@ static declaration_t *parse_parameter(void)
 
        parse_declaration_specifiers(&specifiers);
 
-       declaration_t *declaration
-               = parse_declarator(&specifiers, specifiers.type, true);
-
-       /* TODO check declaration constraints for parameters */
-       if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
-               parse_error("typedef not allowed in parameter list");
-       }
+       declaration_t *declaration = parse_declarator(&specifiers, true);
 
-       /* Array as last part of a paramter type is just syntactic sugar.  Turn it
-        * into a pointer */
-       if (declaration->type->type == TYPE_ARRAY) {
-               const array_type_t *const arr_type = &declaration->type->array;
-               type_t *element_type = arr_type->element_type;
-               declaration->type = make_pointer_type(element_type, TYPE_QUALIFIER_NONE);
-       }
+       semantic_parameter(declaration);
 
        return declaration;
 }
@@ -1845,11 +2026,10 @@ static declaration_t *parse_parameter(void)
 static declaration_t *parse_parameters(function_type_t *type)
 {
        if(token.type == T_IDENTIFIER) {
-               symbol_t      *symbol = token.v.symbol;
+               symbol_t *symbol = token.v.symbol;
                if(!is_typedef_symbol(symbol)) {
-                       /* TODO: K&R style C parameters */
-                       parse_identifier_list();
-                       return NULL;
+                       type->kr_style_parameters = true;
+                       return parse_identifier_list();
                }
        }
 
@@ -2124,7 +2304,7 @@ static type_t *construct_declarator_type(construct_type_t *construct_list,
 
                        type_t *function_type = construct_function_type->function_type;
 
-                       function_type->function.result_type = type;
+                       function_type->function.return_type = type;
 
                        type = function_type;
                        break;
@@ -2170,9 +2350,9 @@ static type_t *construct_declarator_type(construct_type_t *construct_list,
 }
 
 static declaration_t *parse_declarator(
-               const declaration_specifiers_t *specifiers,
-               type_t *type, bool may_be_abstract)
+               const declaration_specifiers_t *specifiers, bool may_be_abstract)
 {
+       type_t        *type        = specifiers->type;
        declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
        declaration->storage_class = specifiers->storage_class;
        declaration->is_inline     = specifiers->is_inline;
@@ -2202,6 +2382,7 @@ static type_t *parse_abstract_declarator(type_t *base_type)
 
 static declaration_t *record_declaration(declaration_t *declaration)
 {
+       assert(declaration->parent_context == NULL);
        assert(context != NULL);
 
        symbol_t *symbol = declaration->symbol;
@@ -2223,210 +2404,416 @@ static declaration_t *record_declaration(declaration_t *declaration)
        return declaration;
 }
 
-static void parser_error_multiple_definition(declaration_t *previous,
-                                             declaration_t *declaration)
+static void parser_error_multiple_definition(declaration_t *declaration,
+               const source_position_t source_position)
 {
-       parser_print_error_prefix_pos(declaration->source_position);
+       parser_print_error_prefix_pos(source_position);
        fprintf(stderr, "multiple definition of symbol '%s'\n",
                declaration->symbol->string);
-       parser_print_error_prefix_pos(previous->source_position);
+       parser_print_error_prefix_pos(declaration->source_position);
        fprintf(stderr, "this is the location of the previous definition.\n");
 }
 
-static void parse_init_declarators(const declaration_specifiers_t *specifiers)
+static bool is_declaration_specifier(const token_t *token,
+                                     bool only_type_specifiers)
 {
-       while(true) {
-               declaration_t *ndeclaration
-                       = parse_declarator(specifiers, specifiers->type, false);
-
-               declaration_t *declaration = record_declaration(ndeclaration);
+       switch(token->type) {
+               TYPE_SPECIFIERS
+                       return true;
+               case T_IDENTIFIER:
+                       return is_typedef_symbol(token->v.symbol);
 
-               type_t *orig_type = declaration->type;
-               type_t *type      = skip_typeref(orig_type);
-               if(type->type != TYPE_FUNCTION && declaration->is_inline) {
-                       parser_print_warning_prefix_pos(declaration->source_position);
-                       fprintf(stderr, "variable '%s' declared 'inline'\n",
-                               declaration->symbol->string);
-               }
+               case T___extension__:
+               STORAGE_CLASSES
+               TYPE_QUALIFIERS
+                       return !only_type_specifiers;
 
-               if(token.type == '=') {
-                       next_token();
+               default:
+                       return false;
+       }
+}
 
-                       /* TODO: check that this is an allowed type (no function type) */
+static void parse_init_declarator_rest(declaration_t *declaration)
+{
+       eat('=');
 
-                       if(declaration->init.initializer != NULL) {
-                               parser_error_multiple_definition(declaration, ndeclaration);
-                       }
+       type_t *orig_type = declaration->type;
+       type_t *type      = NULL;
+       if(orig_type != NULL)
+               type = skip_typeref(orig_type);
 
-                       initializer_t *initializer = parse_initializer(type);
+       if(declaration->init.initializer != NULL) {
+               parser_error_multiple_definition(declaration, token.source_position);
+       }
 
-                       if(type->type == TYPE_ARRAY && initializer != NULL) {
-                               array_type_t *array_type = &type->array;
+       initializer_t *initializer = parse_initializer(type);
 
-                               if(array_type->size == NULL) {
-                                       const_expression_t
-                                               *cnst = allocate_ast_zero(sizeof(cnst[0]));
+       /* ยง 6.7.5 (22)  array intializers for arrays with unknown size determine
+        * the array type size */
+       if(type != NULL && is_type_array(type) && initializer != NULL) {
+               array_type_t *array_type = &type->array;
 
-                                       cnst->expression.type     = EXPR_CONST;
-                                       cnst->expression.datatype = type_size_t;
+               if(array_type->size == NULL) {
+                       expression_t *cnst = allocate_expression_zero(EXPR_CONST);
 
-                                       if(initializer->type == INITIALIZER_LIST) {
-                                               initializer_list_t *list = &initializer->list;
-                                               cnst->v.int_value = list->len;
-                                       } else {
-                                               assert(initializer->type == INITIALIZER_STRING);
-                                               initializer_string_t *string = &initializer->string;
-                                               cnst->v.int_value = strlen(string->string) + 1;
-                                       }
+                       cnst->base.datatype = type_size_t;
 
-                                       array_type->size = (expression_t*) cnst;
+                       switch (initializer->type) {
+                               case INITIALIZER_LIST: {
+                                       initializer_list_t *const list = &initializer->list;
+                                       cnst->conste.v.int_value = list->len;
+                                       break;
                                }
-                       }
 
+                               case INITIALIZER_STRING: {
+                                       initializer_string_t *const string = &initializer->string;
+                                       cnst->conste.v.int_value = strlen(string->string) + 1;
+                                       break;
+                               }
 
-                       ndeclaration->init.initializer = initializer;
-               } else if(token.type == '{') {
-                       if(type->type != TYPE_FUNCTION) {
-                               parser_print_error_prefix();
-                               fprintf(stderr, "declarator '");
-                               print_type_ext(orig_type, declaration->symbol, NULL);
-                               fprintf(stderr, "' has a body but is not a function type.\n");
-                               eat_block();
-                               continue;
-                       }
+                               case INITIALIZER_WIDE_STRING: {
+                                       initializer_wide_string_t *const string = &initializer->wide_string;
+                                       cnst->conste.v.int_value = string->string.size;
+                                       break;
+                               }
 
-                       if(declaration->init.statement != NULL) {
-                               parser_error_multiple_definition(declaration, ndeclaration);
-                       }
-                       if(ndeclaration != declaration) {
-                               memcpy(&declaration->context, &ndeclaration->context,
-                                      sizeof(declaration->context));
+                               default:
+                                       panic("invalid initializer type");
                        }
 
-                       int         top          = environment_top();
-                       context_t  *last_context = context;
-                       set_context(&declaration->context);
+                       array_type->size = cnst;
+               }
+       }
 
-                       /* push function parameters */
-                       declaration_t *parameter = declaration->context.declarations;
-                       for( ; parameter != NULL; parameter = parameter->next) {
-                               environment_push(parameter);
-                       }
+       if(type != NULL && is_type_function(type)) {
+               parser_print_error_prefix_pos(declaration->source_position);
+               fprintf(stderr, "initializers not allowed for function types at "
+                               "declator '%s' (type ", declaration->symbol->string);
+               print_type_quoted(orig_type);
+               fprintf(stderr, ")\n");
+       } else {
+               declaration->init.initializer = initializer;
+       }
+}
 
-                       int            label_stack_top      = label_top();
-                       declaration_t *old_current_function = current_function;
-                       current_function                    = declaration;
+/* parse rest of a declaration without any declarator */
+static void parse_anonymous_declaration_rest(
+               const declaration_specifiers_t *specifiers,
+               parsed_declaration_func finished_declaration)
+{
+       eat(';');
 
-                       statement_t *statement = parse_compound_statement();
+       declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
 
-                       assert(current_function == declaration);
-                       current_function = old_current_function;
-                       label_pop_to(label_stack_top);
+       declaration->type            = specifiers->type;
+       declaration->storage_class   = specifiers->storage_class;
+       declaration->source_position = specifiers->source_position;
 
-                       assert(context == &declaration->context);
-                       set_context(last_context);
-                       environment_pop_to(top);
+       if (declaration->storage_class != STORAGE_CLASS_NONE) {
+               parse_warning_pos(declaration->source_position,
+                               "useless storage class in empty declaration");
+       }
 
-                       declaration->init.statement = statement;
-                       return;
+       type_t *type = declaration->type;
+       switch (type->type) {
+               case TYPE_COMPOUND_STRUCT:
+               case TYPE_COMPOUND_UNION: {
+                       const compound_type_t *compound_type = &type->compound;
+                       if (compound_type->declaration->symbol == NULL) {
+                               parse_warning_pos(declaration->source_position,
+                                               "unnamed struct/union that defines no instances");
+                       }
+                       break;
                }
 
-               if(token.type != ',')
+               case TYPE_ENUM:
+                       break;
+
+               default:
+                       parse_warning_pos(declaration->source_position,
+                                         "empty declaration");
                        break;
-               next_token();
        }
-       expect_void(';');
+
+       finished_declaration(declaration);
 }
 
-static void parse_struct_declarators(const declaration_specifiers_t *specifiers)
+static void parse_declaration_rest(declaration_t *ndeclaration,
+               const declaration_specifiers_t *specifiers,
+               parsed_declaration_func finished_declaration)
 {
-       while(1) {
-               if(token.type == ':') {
-                       next_token();
-                       parse_constant_expression();
-                       /* TODO (bitfields) */
-               } else {
-                       declaration_t *declaration
-                               = parse_declarator(specifiers, specifiers->type, true);
+       while(true) {
+               declaration_t *declaration = finished_declaration(ndeclaration);
 
-                       /* TODO: check constraints for struct declarations */
-                       /* TODO: check for doubled fields */
-                       record_declaration(declaration);
+               type_t *orig_type = declaration->type;
+               type_t *type      = skip_typeref(orig_type);
 
-                       if(token.type == ':') {
-                               next_token();
-                               parse_constant_expression();
-                               /* TODO (bitfields) */
-                       }
+               if(type->type != TYPE_FUNCTION && declaration->is_inline) {
+                       parser_print_warning_prefix_pos(declaration->source_position);
+                       fprintf(stderr, "variable '%s' declared 'inline'\n",
+                                       declaration->symbol->string);
+               }
+
+               if(token.type == '=') {
+                       parse_init_declarator_rest(declaration);
                }
 
                if(token.type != ',')
                        break;
-               next_token();
+               eat(',');
+
+               ndeclaration = parse_declarator(specifiers, false);
        }
        expect_void(';');
 }
 
-static void parse_compound_type_entries(void)
+static declaration_t *finished_kr_declaration(declaration_t *declaration)
 {
-       eat('{');
+       /* TODO: check that it was actually a parameter that gets a type */
 
-       while(token.type != '}' && token.type != T_EOF) {
-               declaration_specifiers_t specifiers;
-               memset(&specifiers, 0, sizeof(specifiers));
-               parse_declaration_specifiers(&specifiers);
+       /* we should have a declaration for the parameter in the current
+        * scope */
+       return record_declaration(declaration);
+}
 
-               parse_struct_declarators(&specifiers);
-       }
-       if(token.type == T_EOF) {
-               parse_error("unexpected error while parsing struct");
+static void parse_declaration(parsed_declaration_func finished_declaration)
+{
+       declaration_specifiers_t specifiers;
+       memset(&specifiers, 0, sizeof(specifiers));
+       parse_declaration_specifiers(&specifiers);
+
+       if(token.type == ';') {
+               parse_anonymous_declaration_rest(&specifiers, finished_declaration);
+       } else {
+               declaration_t *declaration = parse_declarator(&specifiers, false);
+               parse_declaration_rest(declaration, &specifiers, finished_declaration);
        }
-       next_token();
 }
 
-static void parse_declaration(void)
+static void parse_kr_declaration_list(declaration_t *declaration)
 {
-       source_position_t source_position = token.source_position;
+       type_t *type = skip_typeref(declaration->type);
+       if(!is_type_function(type))
+               return;
+
+       if(!type->function.kr_style_parameters)
+               return;
+
+       /* push function parameters */
+       int         top          = environment_top();
+       context_t  *last_context = context;
+       set_context(&declaration->context);
+
+       declaration_t *parameter = declaration->context.declarations;
+       for( ; parameter != NULL; parameter = parameter->next) {
+               environment_push(parameter);
+       }
+
+       /* parse declaration list */
+       while(is_declaration_specifier(&token, false)) {
+               parse_declaration(finished_kr_declaration);
+       }
+
+       /* pop function parameters */
+       assert(context == &declaration->context);
+       set_context(last_context);
+       environment_pop_to(top);
+
+       /* update function type */
+       type_t *new_type = duplicate_type(type);
+       new_type->function.kr_style_parameters = false;
+
+       function_parameter_t *parameters     = NULL;
+       function_parameter_t *last_parameter = NULL;
+
+       declaration_t *parameter_declaration = declaration->context.declarations;
+       for( ; parameter_declaration != NULL;
+                       parameter_declaration = parameter_declaration->next) {
+               type_t *parameter_type = parameter_declaration->type;
+               if(parameter_type == NULL) {
+#ifdef STRICT_C99
+                       parser_print_error_prefix();
+                       fprintf(stderr, "no type specified for function parameter '%s'\n",
+                               parameter_declaration->symbol->string);
+#else
+                       parser_print_warning_prefix();
+                       fprintf(stderr, "no type specified for function parameter '%s', "
+                               "using int\n", parameter_declaration->symbol->string);
+                       parameter_type              = type_int;
+                       parameter_declaration->type = parameter_type;
+#endif
+               }
+
+               semantic_parameter(parameter_declaration);
+               parameter_type = parameter_declaration->type;
+
+               function_parameter_t *function_parameter
+                       = obstack_alloc(type_obst, sizeof(function_parameter[0]));
+               memset(function_parameter, 0, sizeof(function_parameter[0]));
 
+               function_parameter->type = parameter_type;
+               if(last_parameter != NULL) {
+                       last_parameter->next = function_parameter;
+               } else {
+                       parameters = function_parameter;
+               }
+               last_parameter = function_parameter;
+       }
+       new_type->function.parameters = parameters;
+
+       type = typehash_insert(new_type);
+       if(type != new_type) {
+               obstack_free(type_obst, new_type);
+       }
+
+       declaration->type = type;
+}
+
+static void parse_external_declaration(void)
+{
+       /* function-definitions and declarations both start with declaration
+        * specifiers */
        declaration_specifiers_t specifiers;
        memset(&specifiers, 0, sizeof(specifiers));
        parse_declaration_specifiers(&specifiers);
 
+       /* must be a declaration */
        if(token.type == ';') {
-               if (specifiers.storage_class != STORAGE_CLASS_NONE) {
-                       parse_warning_pos(source_position,
-                                         "useless keyword in empty declaration");
+               parse_anonymous_declaration_rest(&specifiers, record_declaration);
+               return;
+       }
+
+       /* declarator is common to both function-definitions and declarations */
+       declaration_t *ndeclaration = parse_declarator(&specifiers, false);
+
+       /* must be a declaration */
+       if(token.type == ',' || token.type == '=' || token.type == ';') {
+               parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
+               return;
+       }
+
+       /* must be a function definition */
+       parse_kr_declaration_list(ndeclaration);
+
+       if(token.type != '{') {
+               parse_error_expected("while parsing function definition", '{', 0);
+               eat_statement();
+               return;
+       }
+
+       type_t *type = ndeclaration->type;
+       if(type == NULL) {
+               eat_block();
+               return;
+       }
+
+       /* note that we don't skip typerefs: the standard doesn't allow them here
+        * (so we can't use is_type_function here) */
+       if(type->type != TYPE_FUNCTION) {
+               parser_print_error_prefix();
+               fprintf(stderr, "declarator '");
+               print_type_ext(type, ndeclaration->symbol, NULL);
+               fprintf(stderr, "' has a body but is not a function type.\n");
+               eat_block();
+               return;
+       }
+
+       /* ยง 6.7.5.3 (14) a function definition with () means no
+        * parameters (and not unspecified parameters) */
+       if(type->function.unspecified_parameters) {
+               type_t *duplicate = duplicate_type(type);
+               duplicate->function.unspecified_parameters = false;
+
+               type = typehash_insert(duplicate);
+               if(type != duplicate) {
+                       obstack_free(type_obst, duplicate);
                }
-               switch (specifiers.type->type) {
-                       case TYPE_COMPOUND_STRUCT:
-                       case TYPE_COMPOUND_UNION: {
-                               const compound_type_t *const comp_type
-                                       = &specifiers.type->compound;
-                               if (comp_type->declaration->symbol == NULL) {
-                                       parse_warning_pos(source_position,
-                                                                                                               "unnamed struct/union that defines no instances");
-                               }
-                               break;
-                       }
+               ndeclaration->type = type;
+       }
 
-                       case TYPE_ENUM: break;
+       declaration_t *declaration = record_declaration(ndeclaration);
+       if(ndeclaration != declaration) {
+               memcpy(&declaration->context, &ndeclaration->context,
+                               sizeof(declaration->context));
+       }
+       type = skip_typeref(declaration->type);
 
-                       default:
-                               parse_warning_pos(source_position, "empty declaration");
-                               break;
+       /* push function parameters and switch context */
+       int         top          = environment_top();
+       context_t  *last_context = context;
+       set_context(&declaration->context);
+
+       declaration_t *parameter = declaration->context.declarations;
+       for( ; parameter != NULL; parameter = parameter->next) {
+               environment_push(parameter);
+       }
+
+       if(declaration->init.statement != NULL) {
+               parser_error_multiple_definition(declaration, token.source_position);
+               eat_block();
+               goto end_of_parse_external_declaration;
+       } else {
+               /* parse function body */
+               int            label_stack_top      = label_top();
+               declaration_t *old_current_function = current_function;
+               current_function                    = declaration;
+
+               declaration->init.statement = parse_compound_statement();
+
+               assert(current_function == declaration);
+               current_function = old_current_function;
+               label_pop_to(label_stack_top);
+       }
+
+end_of_parse_external_declaration:
+       assert(context == &declaration->context);
+       set_context(last_context);
+       environment_pop_to(top);
+}
+
+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 = parse_declarator(specifiers, true);
+
+                       /* TODO: check constraints for struct declarations */
+                       /* TODO: check for doubled fields */
+                       record_declaration(declaration);
+
+                       if(token.type == ':') {
+                               next_token();
+                               parse_constant_expression();
+                               /* TODO (bitfields) */
+                       }
                }
 
+               if(token.type != ',')
+                       break;
                next_token();
+       }
+       expect_void(';');
+}
 
-               declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
+static void parse_compound_type_entries(void)
+{
+       eat('{');
 
-               declaration->type            = specifiers.type;
-               declaration->storage_class   = specifiers.storage_class;
-               declaration->source_position = source_position;
-               record_declaration(declaration);
-               return;
+       while(token.type != '}' && token.type != T_EOF) {
+               declaration_specifiers_t specifiers;
+               memset(&specifiers, 0, sizeof(specifiers));
+               parse_declaration_specifiers(&specifiers);
+
+               parse_struct_declarators(&specifiers);
+       }
+       if(token.type == T_EOF) {
+               parse_error("EOF while parsing struct");
        }
-       parse_init_declarators(&specifiers);
+       next_token();
 }
 
 static type_t *parse_typename(void)
@@ -2463,10 +2850,9 @@ struct expression_parser_function_t {
 
 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
 
-static expression_t *make_invalid_expression(void)
+static expression_t *create_invalid_expression(void)
 {
-       expression_t *expression         = allocate_ast_zero(sizeof(expression[0]));
-       expression->type                 = EXPR_INVALID;
+       expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
        expression->base.source_position = token.source_position;
        return expression;
 }
@@ -2475,56 +2861,59 @@ static expression_t *expected_expression_error(void)
 {
        parser_print_error_prefix();
        fprintf(stderr, "expected expression, got token ");
-       print_token(stderr, & token);
+       print_token(stderr, &token);
        fprintf(stderr, "\n");
 
        next_token();
 
-       return make_invalid_expression();
+       return create_invalid_expression();
 }
 
 static expression_t *parse_string_const(void)
 {
-       string_literal_expression_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
+       expression_t *cnst  = allocate_expression_zero(EXPR_STRING_LITERAL);
+       cnst->base.datatype = type_string;
+       cnst->string.value  = parse_string_literals();
 
-       cnst->expression.type     = EXPR_STRING_LITERAL;
-       cnst->expression.datatype = type_string;
-       cnst->value               = parse_string_literals();
+       return cnst;
+}
 
-       return (expression_t*) cnst;
+static expression_t *parse_wide_string_const(void)
+{
+       expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
+       cnst->base.datatype      = type_wchar_t_ptr;
+       cnst->wide_string.value  = token.v.wide_string; /* TODO concatenate */
+       next_token();
+       return cnst;
 }
 
 static expression_t *parse_int_const(void)
 {
-       const_expression_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
-
-       cnst->expression.type     = EXPR_CONST;
-       cnst->expression.datatype = token.datatype;
-       cnst->v.int_value         = token.v.intvalue;
+       expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
+       cnst->base.datatype      = token.datatype;
+       cnst->conste.v.int_value = token.v.intvalue;
 
        next_token();
 
-       return (expression_t*) cnst;
+       return cnst;
 }
 
 static expression_t *parse_float_const(void)
 {
-       const_expression_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
-
-       cnst->expression.type     = EXPR_CONST;
-       cnst->expression.datatype = token.datatype;
-       cnst->v.float_value       = token.v.floatvalue;
+       expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
+       cnst->base.datatype        = token.datatype;
+       cnst->conste.v.float_value = token.v.floatvalue;
 
        next_token();
 
-       return (expression_t*) cnst;
+       return cnst;
 }
 
 static declaration_t *create_implicit_function(symbol_t *symbol,
                const source_position_t source_position)
 {
        type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
-       ntype->function.result_type            = type_int;
+       ntype->function.return_type            = type_int;
        ntype->function.unspecified_parameters = true;
 
        type_t *type = typehash_insert(ntype);
@@ -2556,7 +2945,7 @@ static declaration_t *create_implicit_function(symbol_t *symbol,
        return declaration;
 }
 
-static type_t *make_function_1_type(type_t *result_type, type_t *argument_type)
+static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
 {
        function_parameter_t *parameter
                = obstack_alloc(type_obst, sizeof(parameter[0]));
@@ -2564,7 +2953,7 @@ static type_t *make_function_1_type(type_t *result_type, type_t *argument_type)
        parameter->type = argument_type;
 
        type_t *type               = allocate_type_zero(TYPE_FUNCTION);
-       type->function.result_type = result_type;
+       type->function.return_type = return_type;
        type->function.parameters  = parameter;
 
        type_t *result = typehash_insert(type);
@@ -2580,6 +2969,14 @@ static type_t *get_builtin_symbol_type(symbol_t *symbol)
        switch(symbol->ID) {
        case T___builtin_alloca:
                return make_function_1_type(type_void_ptr, type_size_t);
+       case T___builtin_nan:
+               return make_function_1_type(type_double, type_string);
+       case T___builtin_nanf:
+               return make_function_1_type(type_float, type_string);
+       case T___builtin_nand:
+               return make_function_1_type(type_long_double, type_string);
+       case T___builtin_va_end:
+               return make_function_1_type(type_void, type_valist);
        default:
                panic("not implemented builtin symbol found");
        }
@@ -2588,12 +2985,13 @@ static type_t *get_builtin_symbol_type(symbol_t *symbol)
 /**
  * performs automatic type cast as described in ยง 6.3.2.1
  */
-static type_t *automatic_type_conversion(type_t *type)
+static type_t *automatic_type_conversion(type_t *orig_type)
 {
-       if(type == NULL)
+       if(orig_type == NULL)
                return NULL;
 
-       if(type->type == TYPE_ARRAY) {
+       type_t *type = skip_typeref(orig_type);
+       if(is_type_array(type)) {
                array_type_t *array_type   = &type->array;
                type_t       *element_type = array_type->element_type;
                unsigned      qualifiers   = array_type->type.qualifiers;
@@ -2601,11 +2999,11 @@ static type_t *automatic_type_conversion(type_t *type)
                return make_pointer_type(element_type, qualifiers);
        }
 
-       if(type->type == TYPE_FUNCTION) {
-               return make_pointer_type(type, TYPE_QUALIFIER_NONE);
+       if(is_type_function(type)) {
+               return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
        }
 
-       return type;
+       return orig_type;
 }
 
 /**
@@ -2619,30 +3017,23 @@ type_t *revert_automatic_type_conversion(const expression_t *expression)
 
        switch(expression->type) {
        case EXPR_REFERENCE: {
-               const reference_expression_t *ref
-                       = (const reference_expression_t*) expression;
+               const reference_expression_t *ref = &expression->reference;
                return ref->declaration->type;
        }
        case EXPR_SELECT: {
-               const select_expression_t *select
-                       = (const select_expression_t*) expression;
+               const select_expression_t *select = &expression->select;
                return select->compound_entry->type;
        }
-       case EXPR_UNARY: {
-               const unary_expression_t *unary
-                       = (const unary_expression_t*) expression;
-               if(unary->type == UNEXPR_DEREFERENCE) {
-                       expression_t   *value        = unary->value;
-                       type_t         *type         = skip_typeref(value->base.datatype);
-                       pointer_type_t *pointer_type = &type->pointer;
+       case EXPR_UNARY_DEREFERENCE: {
+               expression_t   *value        = expression->unary.value;
+               type_t         *type         = skip_typeref(value->base.datatype);
+               pointer_type_t *pointer_type = &type->pointer;
 
-                       return pointer_type->points_to;
-               }
-               break;
+               return pointer_type->points_to;
        }
        case EXPR_BUILTIN_SYMBOL: {
                const builtin_symbol_expression_t *builtin
-                       = (const builtin_symbol_expression_t*) expression;
+                       = &expression->builtin_symbol;
                return get_builtin_symbol_type(builtin->symbol);
        }
        case EXPR_ARRAY_ACCESS: {
@@ -2664,10 +3055,10 @@ type_t *revert_automatic_type_conversion(const expression_t *expression)
 
 static expression_t *parse_reference(void)
 {
-       reference_expression_t *ref = allocate_ast_zero(sizeof(ref[0]));
+       expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
 
-       ref->expression.type = EXPR_REFERENCE;
-       ref->symbol          = token.v.symbol;
+       reference_expression_t *ref = &expression->reference;
+       ref->symbol = token.v.symbol;
 
        declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
 
@@ -2689,7 +3080,7 @@ static expression_t *parse_reference(void)
                {
                        parser_print_error_prefix();
                        fprintf(stderr, "unknown symbol '%s' found.\n", ref->symbol->string);
-                       return (expression_t*) ref;
+                       return expression;
                }
        }
 
@@ -2701,7 +3092,7 @@ static expression_t *parse_reference(void)
        ref->declaration         = declaration;
        ref->expression.datatype = type;
 
-       return (expression_t*) ref;
+       return expression;
 }
 
 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
@@ -2713,11 +3104,9 @@ static void check_cast_allowed(expression_t *expression, type_t *dest_type)
 
 static expression_t *parse_cast(void)
 {
-       unary_expression_t *cast = allocate_ast_zero(sizeof(cast[0]));
+       expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 
-       cast->expression.type            = EXPR_UNARY;
-       cast->type                       = UNEXPR_CAST;
-       cast->expression.source_position = token.source_position;
+       cast->base.source_position = token.source_position;
 
        type_t *type  = parse_typename();
 
@@ -2726,28 +3115,25 @@ static expression_t *parse_cast(void)
 
        check_cast_allowed(value, type);
 
-       cast->expression.datatype = type;
-       cast->value               = value;
+       cast->base.datatype = type;
+       cast->unary.value   = value;
 
-       return (expression_t*) cast;
+       return cast;
 }
 
 static expression_t *parse_statement_expression(void)
 {
-       statement_expression_t *expression
-               = allocate_ast_zero(sizeof(expression[0]));
-       expression->expression.type = EXPR_STATEMENT;
+       expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
 
-       statement_t *statement = parse_compound_statement();
-       expression->statement  = statement;
+       statement_t *statement          = parse_compound_statement();
+       expression->statement.statement = statement;
        if(statement == NULL) {
                expect(')');
                return NULL;
        }
 
        assert(statement->type == STATEMENT_COMPOUND);
-       compound_statement_t *compound_statement
-               = (compound_statement_t*) statement;
+       compound_statement_t *compound_statement = &statement->compound;
 
        /* find last statement and use it's type */
        const statement_t *last_statement = NULL;
@@ -2757,17 +3143,17 @@ static expression_t *parse_statement_expression(void)
        }
 
        if(last_statement->type == STATEMENT_EXPRESSION) {
-               const expression_statement_t *expression_statement =
-                       (const expression_statement_t*) last_statement;
-               expression->expression.datatype
+               const expression_statement_t *expression_statement
+                       = &last_statement->expression;
+               expression->base.datatype
                        = expression_statement->expression->base.datatype;
        } else {
-               expression->expression.datatype = type_void;
+               expression->base.datatype = type_void;
        }
 
        expect(')');
 
-       return (expression_t*) expression;
+       return expression;
 }
 
 static expression_t *parse_brace_expression(void)
@@ -2835,7 +3221,7 @@ static designator_t *parse_designator(void)
        if(token.type != T_IDENTIFIER) {
                parse_error_expected("while parsing member designator",
                                     T_IDENTIFIER, 0);
-               eat_brace();
+               eat_paren();
                return NULL;
        }
        result->symbol = token.v.symbol;
@@ -2848,7 +3234,7 @@ static designator_t *parse_designator(void)
                        if(token.type != T_IDENTIFIER) {
                                parse_error_expected("while parsing member designator",
                                                     T_IDENTIFIER, 0);
-                               eat_brace();
+                               eat_paren();
                                return NULL;
                        }
                        designator_t *designator = allocate_ast_zero(sizeof(result[0]));
@@ -2864,7 +3250,7 @@ static designator_t *parse_designator(void)
                        designator_t *designator = allocate_ast_zero(sizeof(result[0]));
                        designator->array_access = parse_expression();
                        if(designator->array_access == NULL) {
-                               eat_brace();
+                               eat_paren();
                                return NULL;
                        }
                        expect(']');
@@ -2883,50 +3269,125 @@ static expression_t *parse_offsetof(void)
 {
        eat(T___builtin_offsetof);
 
-       offsetof_expression_t *expression
-               = allocate_ast_zero(sizeof(expression[0]));
-       expression->expression.type     = EXPR_OFFSETOF;
-       expression->expression.datatype = type_size_t;
+       expression_t *expression  = allocate_expression_zero(EXPR_OFFSETOF);
+       expression->base.datatype = type_size_t;
 
        expect('(');
-       expression->type = parse_typename();
+       expression->offsetofe.type = parse_typename();
        expect(',');
-       expression->designator = parse_designator();
+       expression->offsetofe.designator = parse_designator();
        expect(')');
 
-       return (expression_t*) expression;
+       return expression;
+}
+
+static expression_t *parse_va_start(void)
+{
+       eat(T___builtin_va_start);
+
+       expression_t *expression = allocate_expression_zero(EXPR_VA_START);
+
+       expect('(');
+       expression->va_starte.ap = parse_assignment_expression();
+       expect(',');
+       expression_t *const expr = parse_assignment_expression();
+       if (expr->type == EXPR_REFERENCE) {
+               declaration_t *const decl = expr->reference.declaration;
+               if (decl->parent_context == &current_function->context &&
+                   decl->next == NULL) {
+                       expression->va_starte.parameter = decl;
+                       expect(')');
+                       return expression;
+               }
+       }
+       parser_print_error_prefix_pos(expr->base.source_position);
+       fprintf(stderr, "second argument of 'va_start' must be last parameter "
+                       "of the current function\n");
+
+       return create_invalid_expression();
 }
 
 static expression_t *parse_va_arg(void)
 {
        eat(T___builtin_va_arg);
 
-       va_arg_expression_t *expression = allocate_ast_zero(sizeof(expression[0]));
-       expression->expression.type     = EXPR_VA_ARG;
+       expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
 
        expect('(');
-       expression->arg = parse_assignment_expression();
+       expression->va_arge.ap = parse_assignment_expression();
        expect(',');
-       expression->expression.datatype = parse_typename();
+       expression->base.datatype = parse_typename();
        expect(')');
 
-       return (expression_t*) expression;
+       return expression;
 }
 
 static expression_t *parse_builtin_symbol(void)
 {
-       builtin_symbol_expression_t *expression
-               = allocate_ast_zero(sizeof(expression[0]));
-       expression->expression.type = EXPR_BUILTIN_SYMBOL;
+       expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
 
-       expression->symbol = token.v.symbol;
+       symbol_t *symbol = token.v.symbol;
+
+       expression->builtin_symbol.symbol = symbol;
        next_token();
 
-       type_t *type = get_builtin_symbol_type(expression->symbol);
+       type_t *type = get_builtin_symbol_type(symbol);
        type = automatic_type_conversion(type);
 
-       expression->expression.datatype = type;
-       return (expression_t*) expression;
+       expression->base.datatype = type;
+       return expression;
+}
+
+static expression_t *parse_compare_builtin(void)
+{
+       expression_t *expression;
+
+       switch(token.type) {
+       case T___builtin_isgreater:
+               expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
+               break;
+       case T___builtin_isgreaterequal:
+               expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
+               break;
+       case T___builtin_isless:
+               expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
+               break;
+       case T___builtin_islessequal:
+               expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
+               break;
+       case T___builtin_islessgreater:
+               expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
+               break;
+       case T___builtin_isunordered:
+               expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
+               break;
+       default:
+               panic("invalid compare builtin found");
+               break;
+       }
+       next_token();
+
+       expect('(');
+       expression->binary.left = parse_assignment_expression();
+       expect(',');
+       expression->binary.right = parse_assignment_expression();
+       expect(')');
+
+       type_t *orig_type_left  = expression->binary.left->base.datatype;
+       type_t *orig_type_right = expression->binary.right->base.datatype;
+       if(orig_type_left == NULL || orig_type_right == NULL)
+               return expression;
+
+       type_t *type_left  = skip_typeref(orig_type_left);
+       type_t *type_right = skip_typeref(orig_type_right);
+       if(!is_type_floating(type_left) && !is_type_floating(type_right)) {
+               type_error_incompatible("invalid operands in comparison",
+                                       token.source_position, type_left, type_right);
+       } else {
+               semantic_comparison(&expression->binary);
+       }
+
+       return expression;
 }
 
 static expression_t *parse_primary_expression(void)
@@ -2936,8 +3397,10 @@ static expression_t *parse_primary_expression(void)
                return parse_int_const();
        case T_FLOATINGPOINT:
                return parse_float_const();
-       case T_STRING_LITERAL:
+       case T_STRING_LITERAL: /* TODO merge */
                return parse_string_const();
+       case T_WIDE_STRING_LITERAL:
+               return parse_wide_string_const();
        case T_IDENTIFIER:
                return parse_reference();
        case T___FUNCTION__:
@@ -2947,13 +3410,22 @@ static expression_t *parse_primary_expression(void)
                return parse_pretty_function_keyword();
        case T___builtin_offsetof:
                return parse_offsetof();
+       case T___builtin_va_start:
+               return parse_va_start();
        case T___builtin_va_arg:
                return parse_va_arg();
+       case T___builtin_nanf:
        case T___builtin_alloca:
        case T___builtin_expect:
-       case T___builtin_va_start:
        case T___builtin_va_end:
                return parse_builtin_symbol();
+       case T___builtin_isgreater:
+       case T___builtin_isgreaterequal:
+       case T___builtin_isless:
+       case T___builtin_islessequal:
+       case T___builtin_islessgreater:
+       case T___builtin_isunordered:
+               return parse_compare_builtin();
 
        case '(':
                return parse_brace_expression();
@@ -2965,7 +3437,7 @@ static expression_t *parse_primary_expression(void)
        fprintf(stderr, "\n");
        eat_statement();
 
-       return make_invalid_expression();
+       return create_invalid_expression();
 }
 
 static expression_t *parse_array_expression(unsigned precedence,
@@ -2984,7 +3456,7 @@ static expression_t *parse_array_expression(unsigned precedence,
 
        type_t *type_left   = left->base.datatype;
        type_t *type_inside = inside->base.datatype;
-       type_t *result_type = NULL;
+       type_t *return_type = NULL;
 
        if(type_left != NULL && type_inside != NULL) {
                type_left   = skip_typeref(type_left);
@@ -2992,12 +3464,12 @@ static expression_t *parse_array_expression(unsigned precedence,
 
                if(is_type_pointer(type_left)) {
                        pointer_type_t *pointer = &type_left->pointer;
-                       result_type             = pointer->points_to;
+                       return_type             = pointer->points_to;
                        array_access->array_ref = left;
                        array_access->index     = inside;
                } else if(is_type_pointer(type_inside)) {
                        pointer_type_t *pointer = &type_inside->pointer;
-                       result_type             = pointer->points_to;
+                       return_type             = pointer->points_to;
                        array_access->array_ref = inside;
                        array_access->index     = left;
                        array_access->flipped   = true;
@@ -3020,31 +3492,12 @@ static expression_t *parse_array_expression(unsigned precedence,
        }
        next_token();
 
-       result_type = automatic_type_conversion(result_type);
-       array_access->expression.datatype = result_type;
+       return_type = automatic_type_conversion(return_type);
+       array_access->expression.datatype = return_type;
 
        return (expression_t*) array_access;
 }
 
-static bool is_declaration_specifier(const token_t *token,
-                                     bool only_type_specifiers)
-{
-       switch(token->type) {
-               TYPE_SPECIFIERS
-                       return 1;
-               case T_IDENTIFIER:
-                       return is_typedef_symbol(token->v.symbol);
-               STORAGE_CLASSES
-               TYPE_QUALIFIERS
-                       if(only_type_specifiers)
-                               return 0;
-                       return 1;
-
-               default:
-                       return 0;
-       }
-}
-
 static expression_t *parse_sizeof(unsigned precedence)
 {
        eat(T_sizeof);
@@ -3078,22 +3531,20 @@ static expression_t *parse_select_expression(unsigned precedence,
        bool is_pointer = (token.type == T_MINUSGREATER);
        next_token();
 
-       select_expression_t *select = allocate_ast_zero(sizeof(select[0]));
-
-       select->expression.type = EXPR_SELECT;
-       select->compound        = compound;
+       expression_t *select    = allocate_expression_zero(EXPR_SELECT);
+       select->select.compound = compound;
 
        if(token.type != T_IDENTIFIER) {
                parse_error_expected("while parsing select", T_IDENTIFIER, 0);
-               return (expression_t*) select;
+               return select;
        }
-       symbol_t *symbol = token.v.symbol;
-       select->symbol   = symbol;
+       symbol_t *symbol      = token.v.symbol;
+       select->select.symbol = symbol;
        next_token();
 
        type_t *orig_type = compound->base.datatype;
        if(orig_type == NULL)
-               return make_invalid_expression();
+               return create_invalid_expression();
 
        type_t *type = skip_typeref(orig_type);
 
@@ -3104,7 +3555,7 @@ static expression_t *parse_select_expression(unsigned precedence,
                        fprintf(stderr, "left hand side of '->' is not a pointer, but ");
                        print_type_quoted(orig_type);
                        fputc('\n', stderr);
-                       return make_invalid_expression();
+                       return create_invalid_expression();
                }
                pointer_type_t *pointer_type = &type->pointer;
                type_left                    = pointer_type->points_to;
@@ -3118,7 +3569,7 @@ static expression_t *parse_select_expression(unsigned precedence,
                        "union, but ", symbol->string);
                print_type_quoted(type_left);
                fputc('\n', stderr);
-               return make_invalid_expression();
+               return create_invalid_expression();
        }
 
        compound_type_t *compound_type = &type_left->compound;
@@ -3130,7 +3581,7 @@ static expression_t *parse_select_expression(unsigned precedence,
                        symbol->string);
                print_type_quoted(type_left);
                fputc('\n', stderr);
-               return make_invalid_expression();
+               return create_invalid_expression();
        }
 
        declaration_t *iter = declaration->context.declarations;
@@ -3143,25 +3594,26 @@ static expression_t *parse_select_expression(unsigned precedence,
                parser_print_error_prefix();
                print_type_quoted(type_left);
                fprintf(stderr, " has no member named '%s'\n", symbol->string);
-               return make_invalid_expression();
+               return create_invalid_expression();
        }
 
        /* we always do the auto-type conversions; the & and sizeof parser contains
         * code to revert this! */
        type_t *expression_type = automatic_type_conversion(iter->type);
 
-       select->compound_entry      = iter;
-       select->expression.datatype = expression_type;
-       return (expression_t*) select;
+       select->select.compound_entry = iter;
+       select->base.datatype         = expression_type;
+       return select;
 }
 
 static expression_t *parse_call_expression(unsigned precedence,
                                            expression_t *expression)
 {
        (void) precedence;
-       call_expression_t *call = allocate_ast_zero(sizeof(call[0]));
-       call->expression.type   = EXPR_CALL;
-       call->function          = expression;
+       expression_t *result = allocate_expression_zero(EXPR_CALL);
+
+       call_expression_t *call  = &result->call;
+       call->function           = expression;
 
        function_type_t *function_type = NULL;
        type_t          *orig_type     = expression->base.datatype;
@@ -3173,9 +3625,9 @@ static expression_t *parse_call_expression(unsigned precedence,
 
                        type = skip_typeref(pointer_type->points_to);
 
-                       if (type->type == TYPE_FUNCTION) {
+                       if (is_type_function(type)) {
                                function_type             = &type->function;
-                               call->expression.datatype = function_type->result_type;
+                               call->expression.datatype = function_type->return_type;
                        }
                }
                if(function_type == NULL) {
@@ -3243,11 +3695,11 @@ static expression_t *parse_call_expression(unsigned precedence,
                                /* do default promotion */
                                for( ; argument != NULL; argument = argument->next) {
                                        type_t *type = argument->expression->base.datatype;
-                                       type = skip_typeref(type);
 
                                        if(type == NULL)
                                                continue;
 
+                                       type = skip_typeref(type);
                                        if(is_type_integer(type)) {
                                                type = promote_integer(type);
                                        } else if(type == type_float) {
@@ -3261,75 +3713,88 @@ static expression_t *parse_call_expression(unsigned precedence,
                }
        }
 
-       return (expression_t*) call;
+       return result;
 }
 
 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
 
+static bool same_compound_type(const type_t *type1, const type_t *type2)
+{
+       if(!is_type_compound(type1))
+               return false;
+       if(type1->type != type2->type)
+               return false;
+
+       const compound_type_t *compound1 = &type1->compound;
+       const compound_type_t *compound2 = &type2->compound;
+
+       return compound1->declaration == compound2->declaration;
+}
+
 static expression_t *parse_conditional_expression(unsigned precedence,
                                                   expression_t *expression)
 {
        eat('?');
 
-       conditional_expression_t *conditional
-               = allocate_ast_zero(sizeof(conditional[0]));
-       conditional->expression.type = EXPR_CONDITIONAL;
-       conditional->condition       = expression;
+       expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
+
+       conditional_expression_t *conditional = &result->conditional;
+       conditional->condition = expression;
 
        /* 6.5.15.2 */
-       type_t *condition_type_orig = conditional->condition->base.datatype;
+       type_t *condition_type_orig = expression->base.datatype;
        if(condition_type_orig != NULL) {
-               type_t *condition_type      = skip_typeref(condition_type_orig);
+               type_t *condition_type = skip_typeref(condition_type_orig);
                if(condition_type != NULL && !is_type_scalar(condition_type)) {
-                       type_error("expected a scalar type",
+                       type_error("expected a scalar type in conditional condition",
                                   expression->base.source_position, condition_type_orig);
                }
        }
 
-       expression_t *const t_expr = parse_expression();
-       conditional->true_expression = t_expr;
+       expression_t *true_expression = parse_expression();
        expect(':');
-       expression_t *const f_expr = parse_sub_expression(precedence);
-       conditional->false_expression = f_expr;
+       expression_t *false_expression = parse_sub_expression(precedence);
 
-       type_t *const true_type  = t_expr->base.datatype;
-       if(true_type == NULL)
-               return (expression_t*) conditional;
-       type_t *const false_type = f_expr->base.datatype;
-       if(false_type == NULL)
-               return (expression_t*) conditional;
+       conditional->true_expression  = true_expression;
+       conditional->false_expression = false_expression;
 
-       type_t *const skipped_true_type  = skip_typeref(true_type);
-       type_t *const skipped_false_type = skip_typeref(false_type);
+       type_t *orig_true_type  = true_expression->base.datatype;
+       type_t *orig_false_type = false_expression->base.datatype;
+       if(orig_true_type == NULL || orig_false_type == NULL)
+               return result;
+
+       type_t *true_type  = skip_typeref(orig_true_type);
+       type_t *false_type = skip_typeref(orig_false_type);
 
        /* 6.5.15.3 */
-       if (skipped_true_type == skipped_false_type) {
-               conditional->expression.datatype = skipped_true_type;
-       } else if (is_type_arithmetic(skipped_true_type) &&
-                  is_type_arithmetic(skipped_false_type)) {
-               type_t *const result = semantic_arithmetic(skipped_true_type,
-                                                          skipped_false_type);
-               conditional->true_expression  = create_implicit_cast(t_expr, result);
-               conditional->false_expression = create_implicit_cast(f_expr, result);
-               conditional->expression.datatype = result;
-       } else if (skipped_true_type->type == TYPE_POINTER &&
-                  skipped_false_type->type == TYPE_POINTER &&
-                         true /* TODO compatible points_to types */) {
-               /* TODO */
-       } else if(/* (is_null_ptr_const(skipped_true_type) &&
-                     skipped_false_type->type == TYPE_POINTER)
-              || (is_null_ptr_const(skipped_false_type) &&
-                  skipped_true_type->type == TYPE_POINTER) TODO*/ false) {
-               /* TODO */
-       } else if(/* 1 is pointer to object type, other is void* */ false) {
-               /* TODO */
+       type_t *result_type = NULL;
+       if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
+               result_type = semantic_arithmetic(true_type, false_type);
+
+               true_expression  = create_implicit_cast(true_expression, result_type);
+               false_expression = create_implicit_cast(false_expression, result_type);
+
+               conditional->true_expression     = true_expression;
+               conditional->false_expression    = false_expression;
+               conditional->expression.datatype = result_type;
+       } else if (same_compound_type(true_type, false_type)
+                       || (is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
+                               is_type_atomic(false_type, ATOMIC_TYPE_VOID))) {
+               /* just take 1 of the 2 types */
+               result_type = true_type;
+       } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
+                       && pointers_compatible(true_type, false_type)) {
+               /* ok */
+               result_type = true_type;
        } else {
+               /* TODO */
                type_error_incompatible("while parsing conditional",
                                        expression->base.source_position, true_type,
-                                       skipped_false_type);
+                                       false_type);
        }
 
-       return (expression_t*) conditional;
+       conditional->expression.datatype = result_type;
+       return result;
 }
 
 static expression_t *parse_extension(unsigned precedence)
@@ -3345,17 +3810,15 @@ static expression_t *parse_builtin_classify_type(const unsigned precedence)
 {
        eat(T___builtin_classify_type);
 
-       classify_type_expression_t *const classify_type_expr =
-               allocate_ast_zero(sizeof(classify_type_expr[0]));
-       classify_type_expr->expression.type     = EXPR_CLASSIFY_TYPE;
-       classify_type_expr->expression.datatype = type_int;
+       expression_t *result  = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
+       result->base.datatype = type_int;
 
        expect('(');
-       expression_t *const expression = parse_sub_expression(precedence);
+       expression_t *expression = parse_sub_expression(precedence);
        expect(')');
-       classify_type_expr->type_expression = expression;
+       result->classify_type.type_expression = expression;
 
-       return (expression_t*)classify_type_expr;
+       return result;
 }
 
 static void semantic_incdec(unary_expression_t *expression)
@@ -3469,27 +3932,30 @@ static expression_t *parse_##unexpression_type(unsigned precedence)            \
 {                                                                              \
        eat(token_type);                                                           \
                                                                                \
-       unary_expression_t *unary_expression                                       \
-               = allocate_ast_zero(sizeof(unary_expression[0]));                      \
-       unary_expression->expression.type     = EXPR_UNARY;                        \
-       unary_expression->type                = unexpression_type;                 \
-       unary_expression->value               = parse_sub_expression(precedence);  \
+       expression_t *unary_expression                                             \
+               = allocate_expression_zero(unexpression_type);                         \
+       unary_expression->unary.value = parse_sub_expression(precedence);          \
                                                                                   \
-       sfunc(unary_expression);                                                   \
+       sfunc(&unary_expression->unary);                                           \
                                                                                \
-       return (expression_t*) unary_expression;                                   \
-}
-
-CREATE_UNARY_EXPRESSION_PARSER('-', UNEXPR_NEGATE, semantic_unexpr_arithmetic)
-CREATE_UNARY_EXPRESSION_PARSER('+', UNEXPR_PLUS,   semantic_unexpr_arithmetic)
-CREATE_UNARY_EXPRESSION_PARSER('!', UNEXPR_NOT,    semantic_unexpr_scalar)
-CREATE_UNARY_EXPRESSION_PARSER('*', UNEXPR_DEREFERENCE, semantic_dereference)
-CREATE_UNARY_EXPRESSION_PARSER('&', UNEXPR_TAKE_ADDRESS, semantic_take_addr)
-CREATE_UNARY_EXPRESSION_PARSER('~', UNEXPR_BITWISE_NEGATE,
+       return unary_expression;                                                   \
+}
+
+CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
+                               semantic_unexpr_arithmetic)
+CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
+                               semantic_unexpr_arithmetic)
+CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
+                               semantic_unexpr_scalar)
+CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
+                               semantic_dereference)
+CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
+                               semantic_take_addr)
+CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
                                semantic_unexpr_integer)
-CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_PREFIX_INCREMENT,
+CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
                                semantic_incdec)
-CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_PREFIX_DECREMENT,
+CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
                                semantic_incdec)
 
 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
@@ -3500,20 +3966,20 @@ static expression_t *parse_##unexpression_type(unsigned precedence,           \
        (void) precedence;                                                        \
        eat(token_type);                                                          \
                                                                               \
-       unary_expression_t *unary_expression                                      \
-               = allocate_ast_zero(sizeof(unary_expression[0]));                     \
-       unary_expression->expression.type     = EXPR_UNARY;                       \
-       unary_expression->type                = unexpression_type;                \
-       unary_expression->value               = left;                             \
+       expression_t *unary_expression                                            \
+               = allocate_expression_zero(unexpression_type);                        \
+       unary_expression->unary.value = left;                                     \
                                                                                  \
-       sfunc(unary_expression);                                                  \
+       sfunc(&unary_expression->unary);                                          \
                                                                               \
-       return (expression_t*) unary_expression;                                  \
+       return unary_expression;                                                  \
 }
 
-CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_POSTFIX_INCREMENT,
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
+                                       EXPR_UNARY_POSTFIX_INCREMENT,
                                        semantic_incdec)
-CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT,
+CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
+                                       EXPR_UNARY_POSTFIX_DECREMENT,
                                        semantic_incdec)
 
 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
@@ -3662,10 +4128,9 @@ static void semantic_sub(binary_expression_t *expression)
                expression->right = create_implicit_cast(right, arithmetic_type);
                expression->expression.datatype = arithmetic_type;
                return;
-       } else if(type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
+       } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
                expression->expression.datatype = type_left;
-       } else if(type_left->type == TYPE_POINTER &&
-                       type_right->type == TYPE_POINTER) {
+       } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
                if(!pointers_compatible(type_left, type_right)) {
                        parser_print_error_prefix();
                        fprintf(stderr, "pointers to incompatible objects to binary - (");
@@ -3705,12 +4170,11 @@ static void semantic_comparison(binary_expression_t *expression)
                expression->left  = create_implicit_cast(left, arithmetic_type);
                expression->right = create_implicit_cast(right, arithmetic_type);
                expression->expression.datatype = arithmetic_type;
-       } else if (type_left->type  == TYPE_POINTER &&
-                  type_right->type == TYPE_POINTER) {
+       } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
                /* TODO check compatibility */
-       } else if (type_left->type == TYPE_POINTER) {
+       } else if (is_type_pointer(type_left)) {
                expression->right = create_implicit_cast(right, type_left);
-       } else if (type_right->type == TYPE_POINTER) {
+       } else if (is_type_pointer(type_right)) {
                expression->left = create_implicit_cast(left, type_right);
        } else {
                type_error_incompatible("invalid operands in comparison",
@@ -3769,7 +4233,7 @@ static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
                type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
                expression->right = create_implicit_cast(right, arithmetic_type);
                expression->expression.datatype = type_left;
-       } else if (type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
+       } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
                expression->expression.datatype = type_left;
        } else {
                parser_print_error_prefix();
@@ -3821,10 +4285,10 @@ static void semantic_binexpr_assign(binary_expression_t *expression)
                return;
 
        type_t *type_left = revert_automatic_type_conversion(left);
-       type_left = skip_typeref(orig_type_left);
+       type_left         = skip_typeref(orig_type_left);
 
        /* must be a modifiable lvalue */
-       if (type_left->type == TYPE_ARRAY) {
+       if (is_type_array(type_left)) {
                parser_print_error_prefix();
                fprintf(stderr, "Cannot assign to arrays ('");
                print_expression(left);
@@ -3869,68 +4333,74 @@ static void semantic_comma(binary_expression_t *expression)
        expression->expression.datatype = expression->right->base.datatype;
 }
 
-#define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr) \
-static expression_t *parse_##binexpression_type(unsigned precedence,     \
-                                                expression_t *left)      \
-{                                                                        \
-       eat(token_type);                                                     \
-                                                                         \
-       expression_t *right = parse_sub_expression(precedence + lr);         \
-                                                                         \
-       binary_expression_t *binexpr                                         \
-               = allocate_ast_zero(sizeof(binexpr[0]));                         \
-       binexpr->expression.type     = EXPR_BINARY;                          \
-       binexpr->type                = binexpression_type;                   \
-       binexpr->left                = left;                                 \
-       binexpr->right               = right;                                \
-       sfunc(binexpr);                                                      \
-                                                                         \
-       return (expression_t*) binexpr;                                      \
-}
-
-CREATE_BINEXPR_PARSER(',', BINEXPR_COMMA,          semantic_comma, 1)
-CREATE_BINEXPR_PARSER('*', BINEXPR_MUL,            semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER('/', BINEXPR_DIV,            semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER('%', BINEXPR_MOD,            semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER('+', BINEXPR_ADD,            semantic_add, 1)
-CREATE_BINEXPR_PARSER('-', BINEXPR_SUB,            semantic_sub, 1)
-CREATE_BINEXPR_PARSER('<', BINEXPR_LESS,           semantic_comparison, 1)
-CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER,        semantic_comparison, 1)
-CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN,         semantic_binexpr_assign, 0)
-CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL, semantic_comparison, 1)
-CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, BINEXPR_NOTEQUAL,
+#define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
+static expression_t *parse_##binexpression_type(unsigned precedence,      \
+                                                expression_t *left)       \
+{                                                                         \
+       eat(token_type);                                                      \
+                                                                          \
+       expression_t *right = parse_sub_expression(precedence + lr);          \
+                                                                          \
+       expression_t *binexpr = allocate_expression_zero(binexpression_type); \
+       binexpr->binary.left  = left;                                         \
+       binexpr->binary.right = right;                                        \
+       sfunc(&binexpr->binary);                                              \
+                                                                          \
+       return binexpr;                                                       \
+}
+
+CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
+CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
+CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
+CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
+CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
+CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
+
+CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
+                      semantic_comparison, 1)
+CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
                       semantic_comparison, 1)
-CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL, semantic_comparison, 1)
-CREATE_BINEXPR_PARSER(T_GREATEREQUAL, BINEXPR_GREATEREQUAL,
+CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
                       semantic_comparison, 1)
-CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND,    semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR,     semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR,    semantic_binexpr_arithmetic, 1)
-CREATE_BINEXPR_PARSER(T_ANDAND, BINEXPR_LOGICAL_AND,  semantic_logical_op, 1)
-CREATE_BINEXPR_PARSER(T_PIPEPIPE, BINEXPR_LOGICAL_OR, semantic_logical_op, 1)
-CREATE_BINEXPR_PARSER(T_LESSLESS, BINEXPR_SHIFTLEFT,
+CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
+                      semantic_comparison, 1)
+
+CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
+                      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
+                      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
+                      semantic_binexpr_arithmetic, 1)
+CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
+                      semantic_logical_op, 1)
+CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
+                      semantic_logical_op, 1)
+CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
                       semantic_shift_op, 1)
-CREATE_BINEXPR_PARSER(T_GREATERGREATER, BINEXPR_SHIFTRIGHT,
+CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
                       semantic_shift_op, 1)
-CREATE_BINEXPR_PARSER(T_PLUSEQUAL, BINEXPR_ADD_ASSIGN,
+CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
                       semantic_arithmetic_addsubb_assign, 0)
-CREATE_BINEXPR_PARSER(T_MINUSEQUAL, BINEXPR_SUB_ASSIGN,
+CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
                       semantic_arithmetic_addsubb_assign, 0)
-CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, BINEXPR_MUL_ASSIGN,
+CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_SLASHEQUAL, BINEXPR_DIV_ASSIGN,
+CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, BINEXPR_MOD_ASSIGN,
+CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, BINEXPR_SHIFTLEFT_ASSIGN,
+CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, BINEXPR_SHIFTRIGHT_ASSIGN,
+CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_ANDEQUAL, BINEXPR_BITWISE_AND_ASSIGN,
+CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_PIPEEQUAL, BINEXPR_BITWISE_OR_ASSIGN,
+CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
                       semantic_arithmetic_assign, 0)
-CREATE_BINEXPR_PARSER(T_CARETEQUAL, BINEXPR_BITWISE_XOR_ASSIGN,
+CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
                       semantic_arithmetic_assign, 0)
 
 static expression_t *parse_sub_expression(unsigned precedence)
@@ -3995,9 +4465,8 @@ static void register_expression_parser(parse_expression_function parser,
        entry->precedence = precedence;
 }
 
-static void register_expression_infix_parser(
-               parse_expression_infix_function parser, int token_type,
-               unsigned precedence)
+static void register_infix_parser(parse_expression_infix_function parser,
+               int token_type, unsigned precedence)
 {
        expression_parser_function_t *entry = &expression_parsers[token_type];
 
@@ -4016,101 +4485,201 @@ static void init_expression_parsers(void)
 {
        memset(&expression_parsers, 0, sizeof(expression_parsers));
 
-       register_expression_infix_parser(parse_BINEXPR_MUL,         '*',        16);
-       register_expression_infix_parser(parse_BINEXPR_DIV,         '/',        16);
-       register_expression_infix_parser(parse_BINEXPR_MOD,         '%',        16);
-       register_expression_infix_parser(parse_BINEXPR_SHIFTLEFT,   T_LESSLESS, 16);
-       register_expression_infix_parser(parse_BINEXPR_SHIFTRIGHT,
-                                                             T_GREATERGREATER, 16);
-       register_expression_infix_parser(parse_BINEXPR_ADD,         '+',        15);
-       register_expression_infix_parser(parse_BINEXPR_SUB,         '-',        15);
-       register_expression_infix_parser(parse_BINEXPR_LESS,        '<',        14);
-       register_expression_infix_parser(parse_BINEXPR_GREATER,     '>',        14);
-       register_expression_infix_parser(parse_BINEXPR_LESSEQUAL, T_LESSEQUAL,  14);
-       register_expression_infix_parser(parse_BINEXPR_GREATEREQUAL,
-                                                               T_GREATEREQUAL, 14);
-       register_expression_infix_parser(parse_BINEXPR_EQUAL,     T_EQUALEQUAL, 13);
-       register_expression_infix_parser(parse_BINEXPR_NOTEQUAL,
-                                                       T_EXCLAMATIONMARKEQUAL, 13);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_AND, '&',        12);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_XOR, '^',        11);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_OR,  '|',        10);
-       register_expression_infix_parser(parse_BINEXPR_LOGICAL_AND, T_ANDAND,    9);
-       register_expression_infix_parser(parse_BINEXPR_LOGICAL_OR,  T_PIPEPIPE,  8);
-       register_expression_infix_parser(parse_conditional_expression, '?',      7);
-       register_expression_infix_parser(parse_BINEXPR_ASSIGN,      '=',         2);
-       register_expression_infix_parser(parse_BINEXPR_ADD_ASSIGN, T_PLUSEQUAL,  2);
-       register_expression_infix_parser(parse_BINEXPR_SUB_ASSIGN, T_MINUSEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_MUL_ASSIGN,
-                                                               T_ASTERISKEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_DIV_ASSIGN, T_SLASHEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_MOD_ASSIGN,
-                                                                T_PERCENTEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_SHIFTLEFT_ASSIGN,
+       register_infix_parser(parse_array_expression,         '[',              30);
+       register_infix_parser(parse_call_expression,          '(',              30);
+       register_infix_parser(parse_select_expression,        '.',              30);
+       register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
+       register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
+                                                             T_PLUSPLUS,       30);
+       register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
+                                                             T_MINUSMINUS,     30);
+
+       register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
+       register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
+       register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
+       register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
+       register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
+       register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
+       register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
+       register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
+       register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
+       register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
+       register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
+       register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
+       register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
+                                                    T_EXCLAMATIONMARKEQUAL, 13);
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
+       register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
+       register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
+       register_infix_parser(parse_conditional_expression,   '?',               7);
+       register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
+       register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
+       register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
+       register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
+       register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
+       register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
+       register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
                                                                T_LESSLESSEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_SHIFTRIGHT_ASSIGN,
+       register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
                                                          T_GREATERGREATEREQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_AND_ASSIGN,
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
                                                                     T_ANDEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_OR_ASSIGN,
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
                                                                    T_PIPEEQUAL, 2);
-       register_expression_infix_parser(parse_BINEXPR_BITWISE_XOR_ASSIGN,
+       register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
                                                                   T_CARETEQUAL, 2);
 
-       register_expression_infix_parser(parse_BINEXPR_COMMA,       ',',         1);
-
-       register_expression_infix_parser(parse_array_expression,        '[',    30);
-       register_expression_infix_parser(parse_call_expression,         '(',    30);
-       register_expression_infix_parser(parse_select_expression,       '.',    30);
-       register_expression_infix_parser(parse_select_expression,
-                                                               T_MINUSGREATER, 30);
-       register_expression_infix_parser(parse_UNEXPR_POSTFIX_INCREMENT,
-                                        T_PLUSPLUS, 30);
-       register_expression_infix_parser(parse_UNEXPR_POSTFIX_DECREMENT,
-                                        T_MINUSMINUS, 30);
-
-       register_expression_parser(parse_UNEXPR_NEGATE,           '-',          25);
-       register_expression_parser(parse_UNEXPR_PLUS,             '+',          25);
-       register_expression_parser(parse_UNEXPR_NOT,              '!',          25);
-       register_expression_parser(parse_UNEXPR_BITWISE_NEGATE,   '~',          25);
-       register_expression_parser(parse_UNEXPR_DEREFERENCE,      '*',          25);
-       register_expression_parser(parse_UNEXPR_TAKE_ADDRESS,     '&',          25);
-       register_expression_parser(parse_UNEXPR_PREFIX_INCREMENT, T_PLUSPLUS,   25);
-       register_expression_parser(parse_UNEXPR_PREFIX_DECREMENT, T_MINUSMINUS, 25);
+       register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
+
+       register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
+       register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
+       register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
+       register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
+       register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
+       register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
+       register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
+                                                                 T_PLUSPLUS,   25);
+       register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
+                                                                 T_MINUSMINUS, 25);
        register_expression_parser(parse_sizeof,                  T_sizeof,     25);
        register_expression_parser(parse_extension,            T___extension__, 25);
        register_expression_parser(parse_builtin_classify_type,
                                                     T___builtin_classify_type, 25);
 }
 
+static asm_constraint_t *parse_asm_constraints(void)
+{
+       asm_constraint_t *result = NULL;
+       asm_constraint_t *last   = NULL;
+
+       while(token.type == T_STRING_LITERAL || token.type == '[') {
+               asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
+               memset(constraint, 0, sizeof(constraint[0]));
+
+               if(token.type == '[') {
+                       eat('[');
+                       if(token.type != T_IDENTIFIER) {
+                               parse_error_expected("while parsing asm constraint",
+                                                    T_IDENTIFIER, 0);
+                               return NULL;
+                       }
+                       constraint->symbol = token.v.symbol;
+
+                       expect(']');
+               }
+
+               constraint->constraints = parse_string_literals();
+               expect('(');
+               constraint->expression = parse_expression();
+               expect(')');
+
+               if(last != NULL) {
+                       last->next = constraint;
+               } else {
+                       result = constraint;
+               }
+               last = constraint;
+
+               if(token.type != ',')
+                       break;
+               eat(',');
+       }
+
+       return result;
+}
+
+static asm_clobber_t *parse_asm_clobbers(void)
+{
+       asm_clobber_t *result = NULL;
+       asm_clobber_t *last   = NULL;
+
+       while(token.type == T_STRING_LITERAL) {
+               asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
+               clobber->clobber       = parse_string_literals();
+
+               if(last != NULL) {
+                       last->next = clobber;
+               } else {
+                       result = clobber;
+               }
+               last = clobber;
+
+               if(token.type != ',')
+                       break;
+               eat(',');
+       }
+
+       return result;
+}
+
+static statement_t *parse_asm_statement(void)
+{
+       eat(T_asm);
+
+       statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
+       statement->base.source_position = token.source_position;
+
+       asm_statement_t *asm_statement = &statement->asms;
+
+       if(token.type == T_volatile) {
+               next_token();
+               asm_statement->is_volatile = true;
+       }
+
+       expect('(');
+       asm_statement->asm_text = parse_string_literals();
+
+       if(token.type != ':')
+               goto end_of_asm;
+       eat(':');
+
+       asm_statement->inputs = parse_asm_constraints();
+       if(token.type != ':')
+               goto end_of_asm;
+       eat(':');
+
+       asm_statement->outputs = parse_asm_constraints();
+       if(token.type != ':')
+               goto end_of_asm;
+       eat(':');
+
+       asm_statement->clobbers = parse_asm_clobbers();
+
+end_of_asm:
+       expect(')');
+       expect(';');
+       return statement;
+}
 
 static statement_t *parse_case_statement(void)
 {
        eat(T_case);
-       case_label_statement_t *label = allocate_ast_zero(sizeof(label[0]));
-       label->statement.type            = STATEMENT_CASE_LABEL;
-       label->statement.source_position = token.source_position;
 
-       label->expression = parse_expression();
+       statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
+
+       statement->base.source_position  = token.source_position;
+       statement->case_label.expression = parse_expression();
 
        expect(':');
-       label->label_statement = parse_statement();
+       statement->case_label.label_statement = parse_statement();
 
-       return (statement_t*) label;
+       return statement;
 }
 
 static statement_t *parse_default_statement(void)
 {
        eat(T_default);
 
-       case_label_statement_t *label = allocate_ast_zero(sizeof(label[0]));
-       label->statement.type            = STATEMENT_CASE_LABEL;
-       label->statement.source_position = token.source_position;
+       statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
+
+       statement->base.source_position = token.source_position;
 
        expect(':');
-       label->label_statement = parse_statement();
+       statement->label.label_statement = parse_statement();
 
-       return (statement_t*) label;
+       return statement;
 }
 
 static declaration_t *get_label(symbol_t *symbol)
@@ -4126,7 +4695,7 @@ static declaration_t *get_label(symbol_t *symbol)
 
        /* otherwise we need to create a new one */
        declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
-       declaration->namespc     = NAMESPACE_LABEL;
+       declaration->namespc       = NAMESPACE_LABEL;
        declaration->symbol        = symbol;
 
        label_push(declaration);
@@ -4259,7 +4828,7 @@ static statement_t *parse_for(void)
 
        if(token.type != ';') {
                if(is_declaration_specifier(&token, false)) {
-                       parse_declaration();
+                       parse_declaration(record_declaration);
                } else {
                        statement->initialisation = parse_expression();
                        expect(';');
@@ -4344,9 +4913,9 @@ static statement_t *parse_return(void)
        statement->statement.type            = STATEMENT_RETURN;
        statement->statement.source_position = token.source_position;
 
-       assert(current_function->type->type == TYPE_FUNCTION);
+       assert(is_type_function(current_function->type));
        function_type_t *function_type = &current_function->type->function;
-       type_t          *return_type   = function_type->result_type;
+       type_t          *return_type   = function_type->return_type;
 
        expression_t *return_value = NULL;
        if(token.type != ';') {
@@ -4356,6 +4925,8 @@ static statement_t *parse_return(void)
 
        if(return_type == NULL)
                return (statement_t*) statement;
+       if(return_value != NULL && return_value->base.datatype == NULL)
+               return (statement_t*) statement;
 
        return_type = skip_typeref(return_type);
 
@@ -4384,44 +4955,33 @@ static statement_t *parse_return(void)
 
 static statement_t *parse_declaration_statement(void)
 {
-       declaration_t *before = last_declaration;
-
-       declaration_statement_t *statement
-               = allocate_ast_zero(sizeof(statement[0]));
-       statement->statement.type            = STATEMENT_DECLARATION;
-       statement->statement.source_position = token.source_position;
+       statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
 
-       declaration_specifiers_t specifiers;
-       memset(&specifiers, 0, sizeof(specifiers));
-       parse_declaration_specifiers(&specifiers);
+       statement->base.source_position = token.source_position;
 
-       if(token.type == ';') {
-               eat(';');
-       } else {
-               parse_init_declarators(&specifiers);
-       }
+       declaration_t *before = last_declaration;
+       parse_declaration(record_declaration);
 
        if(before == NULL) {
-               statement->declarations_begin = context->declarations;
+               statement->declaration.declarations_begin = context->declarations;
        } else {
-               statement->declarations_begin = before->next;
+               statement->declaration.declarations_begin = before->next;
        }
-       statement->declarations_end = last_declaration;
+       statement->declaration.declarations_end = last_declaration;
 
-       return (statement_t*) statement;
+       return statement;
 }
 
 static statement_t *parse_expression_statement(void)
 {
-       expression_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
-       statement->statement.type            = STATEMENT_EXPRESSION;
-       statement->statement.source_position = token.source_position;
+       statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
 
-       statement->expression = parse_expression();
+       statement->base.source_position  = token.source_position;
+       statement->expression.expression = parse_expression();
 
        expect(';');
 
-       return (statement_t*) statement;
+       return statement;
 }
 
 static statement_t *parse_statement(void)
@@ -4430,6 +4990,10 @@ static statement_t *parse_statement(void)
 
        /* declaration or statement */
        switch(token.type) {
+       case T_asm:
+               statement = parse_asm_statement();
+               break;
+
        case T_case:
                statement = parse_case_statement();
                break;
@@ -4567,6 +5131,16 @@ static statement_t *parse_compound_statement(void)
        return (statement_t*) compound_statement;
 }
 
+static void initialize_builtins(void)
+{
+       type_wchar_t     = make_global_typedef("__WCHAR_TYPE__", type_int);
+       type_wchar_t_ptr = make_pointer_type(type_wchar_t, TYPE_QUALIFIER_NONE);
+       type_size_t      = make_global_typedef("__SIZE_TYPE__",
+                       make_atomic_type(ATOMIC_TYPE_ULONG, TYPE_QUALIFIER_NONE));
+       type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",
+                       make_atomic_type(ATOMIC_TYPE_LONG, TYPE_QUALIFIER_NONE));
+}
+
 static translation_unit_t *parse_translation_unit(void)
 {
        translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
@@ -4577,8 +5151,10 @@ static translation_unit_t *parse_translation_unit(void)
        assert(context == NULL);
        set_context(&unit->context);
 
+       initialize_builtins();
+
        while(token.type != T_EOF) {
-               parse_declaration();
+               parse_external_declaration();
        }
 
        assert(context == &unit->context);
@@ -4621,15 +5197,18 @@ void init_parser(void)
        obstack_init(&temp_obst);
 
        type_int         = make_atomic_type(ATOMIC_TYPE_INT, TYPE_QUALIFIER_NONE);
-       type_long_double = make_atomic_type(ATOMIC_TYPE_LONG_DOUBLE, TYPE_QUALIFIER_NONE);
-       type_double      = make_atomic_type(ATOMIC_TYPE_DOUBLE, TYPE_QUALIFIER_NONE);
+       type_long_double = make_atomic_type(ATOMIC_TYPE_LONG_DOUBLE,
+                                           TYPE_QUALIFIER_NONE);
+       type_double      = make_atomic_type(ATOMIC_TYPE_DOUBLE,
+                                           TYPE_QUALIFIER_NONE);
        type_float       = make_atomic_type(ATOMIC_TYPE_FLOAT, TYPE_QUALIFIER_NONE);
-       type_size_t      = make_atomic_type(ATOMIC_TYPE_ULONG, TYPE_QUALIFIER_NONE);
-       type_ptrdiff_t   = make_atomic_type(ATOMIC_TYPE_LONG, TYPE_QUALIFIER_NONE);
        type_char        = make_atomic_type(ATOMIC_TYPE_CHAR, TYPE_QUALIFIER_NONE);
        type_void        = make_atomic_type(ATOMIC_TYPE_VOID, TYPE_QUALIFIER_NONE);
        type_void_ptr    = make_pointer_type(type_void, TYPE_QUALIFIER_NONE);
        type_string      = make_pointer_type(type_char, TYPE_QUALIFIER_NONE);
+
+       symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
+       type_valist = create_builtin_type(va_list_sym, type_void_ptr);
 }
 
 void exit_parser(void)