Slightly simplify stack_pop_to().
[cparser] / parser.c
index 0b84140..b800fb8 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -105,15 +105,21 @@ typedef struct parse_initializer_env_t {
 
 typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration, bool is_definition);
 
+/** The current token. */
 static token_t             token;
+/** The lookahead ring-buffer. */
 static token_t             lookahead_buffer[MAX_LOOKAHEAD];
+/** Position of the next token in the lookahead buffer. */
 static int                 lookahead_bufpos;
 static stack_entry_t      *environment_stack = NULL;
 static stack_entry_t      *label_stack       = NULL;
 static stack_entry_t      *local_label_stack = NULL;
+/** The global file scope. */
 static scope_t            *global_scope      = NULL;
+/** The current scope. */
 static scope_t            *scope             = NULL;
 static declaration_t      *last_declaration  = NULL;
+/** Point to the current function declaration if inside a function. */
 static declaration_t      *current_function  = NULL;
 static declaration_t      *current_init_decl = NULL;
 static switch_statement_t *current_switch    = NULL;
@@ -124,9 +130,15 @@ static goto_statement_t   *goto_first        = NULL;
 static goto_statement_t   *goto_last         = NULL;
 static label_statement_t  *label_first       = NULL;
 static label_statement_t  *label_last        = NULL;
+/** current translation unit. */
 static translation_unit_t *unit              = NULL;
+/** true if we are in a type property context (evaluation only for type. */
+static bool                in_type_prop      = false;
+/** true in we are in a __extension__ context. */
+static bool                in_gcc_extension  = false;
 static struct obstack      temp_obst;
 
+
 #define PUSH_PARENT(stmt)                          \
        statement_t *const prev_parent = current_parent; \
        current_parent = (stmt);
@@ -163,6 +175,9 @@ static unsigned char token_anchor_set[T_LAST_TOKEN];
 /** The current source position. */
 #define HERE (&token.source_position)
 
+/** true if we are in GCC mode. */
+#define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
+
 static type_t *type_valist;
 
 static statement_t *parse_compound_statement(bool inside_expression_statement);
@@ -643,16 +658,6 @@ static void eat_block(void)
                next_token();
 }
 
-/**
- * eat all token until a ';' is reached or a stop token is found.
- */
-static void eat_statement(void)
-{
-       eat_until_matching_token(';');
-       if (token.type == ';')
-               next_token();
-}
-
 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while (0)
 
 /**
@@ -711,16 +716,25 @@ static void type_error_incompatible(const char *msg,
                next_token();                                     \
        } while (0)
 
-static void set_scope(scope_t *new_scope)
+static void scope_push(scope_t *new_scope)
 {
        if (scope != NULL) {
                scope->last_declaration = last_declaration;
+               new_scope->depth        = scope->depth + 1;
        }
-       scope = new_scope;
+       new_scope->parent = scope;
+       scope             = new_scope;
 
        last_declaration = new_scope->last_declaration;
 }
 
+static void scope_pop(void)
+{
+       scope->last_declaration = last_declaration;
+       scope = scope->parent;
+       last_declaration = scope->last_declaration;
+}
+
 /**
  * Search a symbol in a given namespace and returns its declaration or
  * NULL if this symbol was not found.
@@ -747,28 +761,20 @@ static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
        namespace_t  namespc = (namespace_t) declaration->namespc;
 
        /* replace/add declaration into declaration list of the symbol */
-       declaration_t *iter = symbol->declaration;
-       if (iter == NULL) {
-               symbol->declaration = declaration;
-       } else {
-               declaration_t *iter_last = NULL;
-               for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
-                       /* replace an entry? */
-                       if (iter->namespc == namespc) {
-                               if (iter_last == NULL) {
-                                       symbol->declaration = declaration;
-                               } else {
-                                       iter_last->symbol_next = declaration;
-                               }
-                               declaration->symbol_next = iter->symbol_next;
-                               break;
-                       }
-               }
-               if (iter == NULL) {
-                       assert(iter_last->symbol_next == NULL);
-                       iter_last->symbol_next = declaration;
+       declaration_t **anchor;
+       declaration_t  *iter;
+       for (anchor = &symbol->declaration;; anchor = &iter->symbol_next) {
+               iter = *anchor;
+               if (iter == NULL)
+                       break;
+
+               /* replace an entry? */
+               if (iter->namespc == namespc) {
+                       declaration->symbol_next = iter->symbol_next;
+                       break;
                }
        }
+       *anchor = declaration;
 
        /* remember old declaration */
        stack_entry_t entry;
@@ -833,30 +839,20 @@ static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
                namespace_t    namespc         = (namespace_t)entry->namespc;
 
                /* replace/remove declaration */
-               declaration_t *declaration = symbol->declaration;
-               assert(declaration != NULL);
-               if (declaration->namespc == namespc) {
-                       if (old_declaration == NULL) {
-                               symbol->declaration = declaration->symbol_next;
-                       } else {
-                               symbol->declaration = old_declaration;
-                       }
-               } else {
-                       declaration_t *iter_last = declaration;
-                       declaration_t *iter      = declaration->symbol_next;
-                       for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
-                               /* replace an entry? */
-                               if (iter->namespc == namespc) {
-                                       assert(iter_last != NULL);
-                                       iter_last->symbol_next = old_declaration;
-                                       if (old_declaration != NULL) {
-                                               old_declaration->symbol_next = iter->symbol_next;
-                                       }
-                                       break;
-                               }
-                       }
+               declaration_t **anchor;
+               declaration_t  *iter;
+               for (anchor = &symbol->declaration;; anchor = &iter->symbol_next) {
+                       iter = *anchor;
                        assert(iter != NULL);
+                       /* replace an entry? */
+                       if (iter->namespc == namespc)
+                               break;
                }
+
+               /* Because of scopes and appending other namespaces to the end of
+                * the list, this must hold. */
+               assert((old_declaration != NULL ? old_declaration->symbol_next : NULL) == iter->symbol_next);
+               *anchor = old_declaration;
        }
 
        ARR_SHRINKLEN(*stack_ptr, (int) new_top);
@@ -2475,6 +2471,10 @@ finish_designator:
 
                        if (type == NULL) {
                                /* we are already outside, ... */
+                               if (is_type_compound(outer_type) &&
+                                   !outer_type->compound.declaration->init.complete) {
+                                       goto error_parse_next;
+                               }
                                goto error_excess;
                        }
 
@@ -2859,16 +2859,16 @@ static type_t *parse_typeof(void)
 
        expression_t *expression  = NULL;
 
-restart:
-       switch(token.type) {
-       case T___extension__:
-               /* This can be a prefix to a typename or an expression.  We simply eat
-                * it now. */
-               do {
-                       next_token();
-               } while (token.type == T___extension__);
-               goto restart;
+       bool old_type_prop     = in_type_prop;
+       bool old_gcc_extension = in_gcc_extension;
+       in_type_prop           = true;
 
+       while (token.type == T___extension__) {
+               /* This can be a prefix to a typename or an expression. */
+               next_token();
+               in_gcc_extension = true;
+       }
+       switch (token.type) {
        case T_IDENTIFIER:
                if (is_typedef_symbol(token.v.symbol)) {
                        type = parse_typename();
@@ -2887,6 +2887,8 @@ restart:
                type       = expression->base.type;
                break;
        }
+       in_type_prop     = old_type_prop;
+       in_gcc_extension = old_gcc_extension;
 
        rem_anchor_token(')');
        expect(')');
@@ -2959,7 +2961,7 @@ static bool check_alignment_value(long long intvalue)
                return false;
        }
        unsigned v = (unsigned)intvalue;
-       for(unsigned i = 1; i <= 8192; i += i) {
+       for (unsigned i = 1; i <= 8192; i += i) {
                if (i == v)
                        return true;
        }
@@ -3030,7 +3032,7 @@ static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *spe
                } else if (symbol == sym_property) {
                        next_token();
                        expect('(');
-                       for(;;) {
+                       for (;;) {
                                bool is_get = false;
                                if (token.type != T_IDENTIFIER)
                                        goto end_error;
@@ -3220,12 +3222,13 @@ static void finish_union_type(compound_type_t *type) {
 
 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
 {
-       type_t            *type            = NULL;
-       type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
-       type_modifiers_t   modifiers       = TYPE_MODIFIER_NONE;
-       unsigned           type_specifiers = 0;
-       bool               newtype         = false;
-       bool               saw_error       = false;
+       type_t            *type              = NULL;
+       type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
+       type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
+       unsigned           type_specifiers   = 0;
+       bool               newtype           = false;
+       bool               saw_error         = false;
+       bool               old_gcc_extension = in_gcc_extension;
 
        specifiers->source_position = token.source_position;
 
@@ -3235,7 +3238,7 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                if (specifiers->modifiers & DM_TRANSPARENT_UNION)
                        modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
 
-               switch(token.type) {
+               switch (token.type) {
 
                /* storage class */
 #define MATCH_STORAGE_CLASS(token, class)                                  \
@@ -3300,8 +3303,8 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
 
                case T___extension__:
-                       /* TODO */
                        next_token();
+                       in_gcc_extension = true;
                        break;
 
                /* type specifiers */
@@ -3446,6 +3449,8 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
        }
 
 finish_specifiers:
+       in_gcc_extension = old_gcc_extension;
+
        if (type == NULL || (saw_error && type_specifiers != 0)) {
                atomic_type_kind_t atomic_type;
 
@@ -3584,10 +3589,8 @@ warn_about_long_long:
                default:
                        /* invalid specifier combination, give an error message */
                        if (type_specifiers == 0) {
-                               if (saw_error) {
-                                       specifiers->type = type_error_type;
-                                       return;
-                               }
+                               if (saw_error)
+                                       goto end_error;
 
                                if (!strict_mode) {
                                        if (warning.implicit_int) {
@@ -3606,15 +3609,13 @@ warn_about_long_long:
                        } else {
                                errorf(HERE, "multiple datatypes in declaration");
                        }
-                       atomic_type = ATOMIC_TYPE_INVALID;
+                       goto end_error;
                }
 
-               if (type_specifiers & SPECIFIER_COMPLEX &&
-                  atomic_type != ATOMIC_TYPE_INVALID) {
+               if (type_specifiers & SPECIFIER_COMPLEX) {
                        type                = allocate_type_zero(TYPE_COMPLEX, &builtin_source_position);
                        type->complex.akind = atomic_type;
-               } else if (type_specifiers & SPECIFIER_IMAGINARY &&
-                         atomic_type != ATOMIC_TYPE_INVALID) {
+               } else if (type_specifiers & SPECIFIER_IMAGINARY) {
                        type                  = allocate_type_zero(TYPE_IMAGINARY, &builtin_source_position);
                        type->imaginary.akind = atomic_type;
                } else {
@@ -3637,7 +3638,10 @@ warn_about_long_long:
        }
 
        specifiers->type = result;
+       return;
+
 end_error:
+       specifiers->type = type_error_type;
        return;
 }
 
@@ -3664,7 +3668,13 @@ static type_qualifiers_t parse_type_qualifiers(void)
        }
 }
 
-static declaration_t *parse_identifier_list(void)
+/**
+ * Parses an K&R identifier list and return a list of declarations.
+ *
+ * @param last  points to the last declaration in the list
+ * @return the list of declarations
+ */
+static declaration_t *parse_identifier_list(declaration_t **last)
 {
        declaration_t *declarations     = NULL;
        declaration_t *last_declaration = NULL;
@@ -3688,6 +3698,7 @@ static declaration_t *parse_identifier_list(void)
                next_token();
        } while (token.type == T_IDENTIFIER);
 
+       *last = last_declaration;
        return declarations;
 }
 
@@ -3740,7 +3751,13 @@ static declaration_t *parse_parameter(void)
        return declaration;
 }
 
-static declaration_t *parse_parameters(function_type_t *type)
+/**
+ * Parses a function type parameter list and return a list of declarations.
+ *
+ * @param last  point to the last element of the list
+ * @return the parameter list
+ */
+static declaration_t *parse_parameters(function_type_t *type, declaration_t **last)
 {
        declaration_t *declarations = NULL;
 
@@ -3753,7 +3770,7 @@ static declaration_t *parse_parameters(function_type_t *type)
                token_type_t la1_type = (token_type_t)look_ahead(1)->type;
                if (la1_type == ',' || la1_type == ')') {
                        type->kr_style_parameters = true;
-                       declarations = parse_identifier_list();
+                       declarations = parse_identifier_list(last);
                        goto parameters_finished;
                }
        }
@@ -3819,10 +3836,12 @@ parameters_finished:
        expect(')');
 
        restore_anchor_state(',', saved_comma_state);
+       *last = last_declaration;
        return declarations;
 
 end_error:
        restore_anchor_state(',', saved_comma_state);
+       *last = NULL;
        return NULL;
 }
 
@@ -3911,9 +3930,8 @@ static construct_type_t *parse_array_declarator(void)
        rem_anchor_token(']');
        expect(']');
 
-       return (construct_type_t*) array;
 end_error:
-       return NULL;
+       return (construct_type_t*) array;
 }
 
 static construct_type_t *parse_function_declarator(declaration_t *declaration)
@@ -3959,9 +3977,12 @@ static construct_type_t *parse_function_declarator(declaration_t *declaration)
                type = allocate_type_zero(TYPE_FUNCTION, HERE);
        }
 
-       declaration_t *parameters = parse_parameters(&type->function);
+       declaration_t *last;
+       declaration_t *parameters = parse_parameters(&type->function, &last);
        if (declaration != NULL) {
-               declaration->scope.declarations = parameters;
+               declaration->scope.declarations     = parameters;
+               declaration->scope.last_declaration = last;
+               declaration->scope.is_parameter     = true;
        }
 
        construct_function_type_t *construct_function_type =
@@ -4052,13 +4073,7 @@ static construct_type_t *parse_inner_declarator(declaration_t *declaration,
                if (may_be_abstract)
                        break;
                parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
-               /* avoid a loop in the outermost scope, because eat_statement doesn't
-                * eat '}' */
-               if (token.type == '}' && current_function == NULL) {
-                       next_token();
-               } else {
-                       eat_statement();
-               }
+               eat_until_anchor();
                return NULL;
        }
 
@@ -4157,15 +4172,19 @@ static type_t *construct_declarator_type(construct_type_t *construct_list,
                        function_type->function.return_type = type;
 
                        type_t *skipped_return_type = skip_typeref(type);
+                       /* Â§6.7.5.3(1) */
                        if (is_type_function(skipped_return_type)) {
                                errorf(HERE, "function returning function is not allowed");
-                               type = type_error_type;
                        } else if (is_type_array(skipped_return_type)) {
                                errorf(HERE, "function returning array is not allowed");
-                               type = type_error_type;
                        } else {
-                               type = function_type;
+                               if (skipped_return_type->base.qualifiers != 0) {
+                                       warningf(HERE,
+                                               "type qualifiers in return type of function type are meaningless");
+                               }
                        }
+
+                       type = function_type;
                        break;
                }
 
@@ -4206,12 +4225,13 @@ static type_t *construct_declarator_type(construct_type_t *construct_list,
                        }
 
                        type_t *skipped_type = skip_typeref(type);
-                       if (is_type_atomic(skipped_type, ATOMIC_TYPE_VOID)) {
-                               errorf(HERE, "array of void is not allowed");
-                               type = type_error_type;
-                       } else {
-                               type = array_type;
+                       /* Â§6.7.5.2(1) */
+                       if (is_type_incomplete(skipped_type)) {
+                               errorf(HERE, "array of incomplete type '%T' is not allowed", type);
+                       } else if (is_type_function(skipped_type)) {
+                               errorf(HERE, "array of functions is not allowed");
                        }
+                       type = array_type;
                        break;
                }
                }
@@ -4308,7 +4328,7 @@ static void check_type_of_main(const declaration_t *const decl, const function_t
                warningf(&decl->source_position,
                         "'main' is normally a non-static function");
        }
-       if (skip_typeref(func_type->return_type) != type_int) {
+       if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
                warningf(&decl->source_position,
                         "return type of 'main' should be 'int', but is '%T'",
                         func_type->return_type);
@@ -4371,7 +4391,7 @@ static declaration_t *record_declaration(
                        previous_declaration == NULL) {
                warningf(&declaration->source_position,
                         "function declaration '%#T' is not a prototype",
-                        orig_type, declaration->symbol);
+                        orig_type, symbol);
        }
 
        if (warning.main && is_type_function(type) && is_sym_main(symbol)) {
@@ -4386,8 +4406,17 @@ static declaration_t *record_declaration(
        }
 
        assert(declaration != previous_declaration);
-       if (previous_declaration != NULL
-                       && previous_declaration->parent_scope == scope) {
+       if (previous_declaration != NULL &&
+           previous_declaration->parent_scope->is_parameter &&
+           scope->depth == previous_declaration->parent_scope->depth + 1) {
+               errorf(&declaration->source_position,
+                       "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
+                       orig_type, symbol, previous_declaration->type, symbol,
+                       &previous_declaration->source_position);
+               goto finish;
+       }
+       if (previous_declaration != NULL &&
+           previous_declaration->parent_scope == scope) {
                /* can happen for K&R style declarations */
                if (previous_declaration->type == NULL) {
                        previous_declaration->type = declaration->type;
@@ -4519,7 +4548,7 @@ warn_redundant_declaration:
                                 "no previous declaration for '%#T'", orig_type, symbol);
                }
        }
-
+finish:
        assert(declaration->parent_scope == NULL);
        assert(scope != NULL);
 
@@ -4539,7 +4568,7 @@ static void parser_error_multiple_definition(declaration_t *declaration,
 static bool is_declaration_specifier(const token_t *token,
                                      bool only_specifiers_qualifiers)
 {
-       switch(token->type) {
+       switch (token->type) {
                TYPE_SPECIFIERS
                TYPE_QUALIFIERS
                        return true;
@@ -4602,24 +4631,17 @@ static void parse_anonymous_declaration_rest(
 {
        eat(';');
 
-       declaration_t *const declaration    = allocate_declaration_zero();
-       declaration->type                   = specifiers->type;
-       declaration->declared_storage_class = specifiers->declared_storage_class;
-       declaration->source_position        = specifiers->source_position;
-       declaration->modifiers              = specifiers->modifiers;
-
-       if (declaration->declared_storage_class != STORAGE_CLASS_NONE) {
-               warningf(&declaration->source_position,
+       if (specifiers->declared_storage_class != STORAGE_CLASS_NONE) {
+               warningf(&specifiers->source_position,
                         "useless storage class in empty declaration");
        }
-       declaration->storage_class = STORAGE_CLASS_NONE;
 
-       type_t *type = declaration->type;
+       type_t *type = specifiers->type;
        switch (type->kind) {
                case TYPE_COMPOUND_STRUCT:
                case TYPE_COMPOUND_UNION: {
                        if (type->compound.declaration->symbol == NULL) {
-                               warningf(&declaration->source_position,
+                               warningf(&specifiers->source_position,
                                         "unnamed struct/union that defines no instances");
                        }
                        break;
@@ -4629,11 +4651,20 @@ static void parse_anonymous_declaration_rest(
                        break;
 
                default:
-                       warningf(&declaration->source_position, "empty declaration");
+                       warningf(&specifiers->source_position, "empty declaration");
                        break;
        }
 
+#ifdef RECORD_EMPTY_DECLARATIONS
+       declaration_t *const declaration    = allocate_declaration_zero();
+       declaration->type                   = specifiers->type;
+       declaration->declared_storage_class = specifiers->declared_storage_class;
+       declaration->source_position        = specifiers->source_position;
+       declaration->modifiers              = specifiers->modifiers;
+       declaration->storage_class          = STORAGE_CLASS_NONE;
+
        append_declaration(declaration);
+#endif
 }
 
 static void parse_declaration_rest(declaration_t *ndeclaration,
@@ -4641,7 +4672,6 @@ static void parse_declaration_rest(declaration_t *ndeclaration,
                parsed_declaration_func finished_declaration)
 {
        add_anchor_token(';');
-       add_anchor_token('=');
        add_anchor_token(',');
        while(true) {
                declaration_t *declaration =
@@ -4665,13 +4695,14 @@ static void parse_declaration_rest(declaration_t *ndeclaration,
                        break;
                eat(',');
 
+               add_anchor_token('=');
                ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
+               rem_anchor_token('=');
        }
        expect(';');
 
 end_error:
        rem_anchor_token(';');
-       rem_anchor_token('=');
        rem_anchor_token(',');
 }
 
@@ -4714,7 +4745,10 @@ static void parse_declaration(parsed_declaration_func finished_declaration)
 {
        declaration_specifiers_t specifiers;
        memset(&specifiers, 0, sizeof(specifiers));
+
+       add_anchor_token(';');
        parse_declaration_specifiers(&specifiers);
+       rem_anchor_token(';');
 
        if (token.type == ';') {
                parse_anonymous_declaration_rest(&specifiers);
@@ -4747,10 +4781,11 @@ static void parse_kr_declaration_list(declaration_t *declaration)
        if (!type->function.kr_style_parameters)
                return;
 
+       add_anchor_token('{');
+
        /* push function parameters */
-       int       top        = environment_top();
-       scope_t  *last_scope = scope;
-       set_scope(&declaration->scope);
+       size_t const top = environment_top();
+       scope_push(&declaration->scope);
 
        declaration_t *parameter = declaration->scope.declarations;
        for ( ; parameter != NULL; parameter = parameter->next) {
@@ -4766,7 +4801,7 @@ static void parse_kr_declaration_list(declaration_t *declaration)
 
        /* pop function parameters */
        assert(scope == &declaration->scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
 
        /* update function type */
@@ -4825,6 +4860,8 @@ static void parse_kr_declaration_list(declaration_t *declaration)
        }
 
        declaration->type = type;
+
+       rem_anchor_token('{');
 }
 
 static bool first_err = true;
@@ -5385,13 +5422,15 @@ static void parse_external_declaration(void)
        add_anchor_token(',');
        add_anchor_token('=');
        add_anchor_token(';');
+       add_anchor_token('{');
 
        /* declarator is common to both function-definitions and declarations */
        declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
 
-       rem_anchor_token(',');
-       rem_anchor_token('=');
+       rem_anchor_token('{');
        rem_anchor_token(';');
+       rem_anchor_token('=');
+       rem_anchor_token(',');
 
        /* must be a declaration */
        switch (token.type) {
@@ -5460,9 +5499,8 @@ static void parse_external_declaration(void)
        type = skip_typeref(declaration->type);
 
        /* push function parameters and switch scope */
-       int       top        = environment_top();
-       scope_t  *last_scope = scope;
-       set_scope(&declaration->scope);
+       size_t const top = environment_top();
+       scope_push(&declaration->scope);
 
        declaration_t *parameter = declaration->scope.declarations;
        for( ; parameter != NULL; parameter = parameter->next) {
@@ -5517,7 +5555,7 @@ static void parse_external_declaration(void)
        }
 
        assert(scope == &declaration->scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
 }
 
@@ -5822,8 +5860,7 @@ static expression_t *parse_character_constant(void)
        cnst->conste.v.character   = token.v.string;
 
        if (cnst->conste.v.character.size != 1) {
-               if (warning.multichar && (c_mode & _GNUC)) {
-                       /* TODO */
+               if (warning.multichar && GNU_MODE) {
                        warningf(HERE, "multi-character character constant");
                } else {
                        errorf(HERE, "more than 1 characters in character constant");
@@ -5846,8 +5883,7 @@ static expression_t *parse_wide_character_constant(void)
        cnst->conste.v.wide_character = token.v.wide_string;
 
        if (cnst->conste.v.wide_character.size != 1) {
-               if (warning.multichar && (c_mode & _GNUC)) {
-                       /* TODO */
+               if (warning.multichar && GNU_MODE) {
                        warningf(HERE, "multi-character character constant");
                } else {
                        errorf(HERE, "more than 1 characters in character constant");
@@ -6095,11 +6131,11 @@ static expression_t *parse_reference(void)
                }
        }
 
-       type_t *type = declaration->type;
+       type_t *orig_type = declaration->type;
 
        /* we always do the auto-type conversions; the & and sizeof parser contains
         * code to revert this! */
-       type = automatic_type_conversion(type);
+       type_t *type = automatic_type_conversion(orig_type);
 
        ref->declaration = declaration;
        ref->base.type   = type;
@@ -6107,6 +6143,15 @@ static expression_t *parse_reference(void)
        /* this declaration is used */
        declaration->used = true;
 
+       if (declaration->parent_scope != global_scope &&
+           declaration->parent_scope->depth < current_function->scope.depth &&
+           is_type_valid(orig_type) && !is_type_function(orig_type)) {
+               /* access of a variable from an outer function */
+               declaration->address_taken     = true;
+               ref->is_outer_ref              = true;
+               current_function->need_closure = true;
+       }
+
        /* check for deprecated functions */
        if (warning.deprecated_declarations &&
            declaration->modifiers & DM_DEPRECATED) {
@@ -6122,7 +6167,7 @@ static expression_t *parse_reference(void)
                                declaration->symbol, &declaration->source_position);
                }
        }
-       if (warning.init_self && declaration == current_init_decl) {
+       if (warning.init_self && declaration == current_init_decl && !in_type_prop) {
                current_init_decl = NULL;
                warningf(HERE, "variable '%#T' is initialized by itself",
                        declaration->type, declaration->symbol);
@@ -6471,17 +6516,15 @@ static expression_t *parse_va_start(void)
        expression_t *const expr = parse_assignment_expression();
        if (expr->kind == EXPR_REFERENCE) {
                declaration_t *const decl = expr->reference.declaration;
-               if (decl == NULL)
-                       return create_invalid_expression();
-               if (decl->parent_scope == &current_function->scope &&
-                   decl->next == NULL) {
-                       expression->va_starte.parameter = decl;
-                       expect(')');
-                       return expression;
+               if (decl->parent_scope != &current_function->scope || decl->next != NULL) {
+                       errorf(&expr->base.source_position,
+                              "second argument of 'va_start' must be last parameter of the current function");
                }
+               expression->va_starte.parameter = decl;
+               expect(')');
+               return expression;
        }
-       errorf(&expr->base.source_position,
-              "second argument of 'va_start' must be last parameter of the current function");
+       expect(')');
 end_error:
        return create_invalid_expression();
 }
@@ -6690,7 +6733,10 @@ static declaration_t *get_label(symbol_t *symbol)
        candidate = get_declaration(symbol, NAMESPACE_LOCAL_LABEL);
        /* if we found a local label, we already created the declaration */
        if (candidate != NULL) {
-               assert(candidate->parent_scope == scope);
+               if (candidate->parent_scope != scope) {
+                       assert(candidate->parent_scope->depth < scope->depth);
+                       current_function->goto_to_outer = true;
+               }
                return candidate;
        }
 
@@ -6820,7 +6866,7 @@ static expression_t *parse_primary_expression(void)
                case T___builtin_prefetch:       return parse_builtin_prefetch();
                case T__assume:                  return parse_assume();
                case T_ANDAND:
-                       if (c_mode & _GNUC)
+                       if (GNU_MODE)
                                return parse_label_address();
                        break;
 
@@ -6905,12 +6951,15 @@ static expression_t *parse_typeprop(expression_kind_t const kind,
                                     source_position_t const pos,
                                     unsigned const precedence)
 {
-       expression_t *tp_expression = allocate_expression_zero(kind);
+       expression_t  *tp_expression = allocate_expression_zero(kind);
        tp_expression->base.type            = type_size_t;
        tp_expression->base.source_position = pos;
 
        char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
 
+       /* we only refer to a type property, mark this case */
+       bool old     = in_type_prop;
+       in_type_prop = true;
        if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
                next_token();
                add_anchor_token(')');
@@ -6951,6 +7000,7 @@ static expression_t *parse_typeprop(expression_kind_t const kind,
        }
 
 end_error:
+       in_type_prop = old;
        return tp_expression;
 }
 
@@ -7248,7 +7298,7 @@ static expression_t *parse_conditional_expression(unsigned precedence,
 
        expression_t *true_expression = expression;
        bool          gnu_cond = false;
-       if ((c_mode & _GNUC) && token.type == ':') {
+       if (GNU_MODE && token.type == ':') {
                gnu_cond = true;
        } else
                true_expression = parse_expression();
@@ -7359,9 +7409,10 @@ static expression_t *parse_extension(unsigned precedence)
 {
        eat(T___extension__);
 
-       /* TODO enable extensions */
+       bool old_gcc_extension   = in_gcc_extension;
+       in_gcc_extension         = true;
        expression_t *expression = parse_sub_expression(precedence);
-       /* TODO disable extensions */
+       in_gcc_extension         = old_gcc_extension;
        return expression;
 }
 
@@ -7395,7 +7446,7 @@ static bool check_pointer_arithmetic(const source_position_t *source_position,
        points_to = skip_typeref(points_to);
 
        if (is_type_incomplete(points_to)) {
-               if (!(c_mode & _GNUC) || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
+               if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
                        errorf(source_position,
                               "arithmetic with pointer to incomplete type '%T' not allowed",
                               orig_pointer_type);
@@ -7406,7 +7457,7 @@ static bool check_pointer_arithmetic(const source_position_t *source_position,
                                 orig_pointer_type);
                }
        } else if (is_type_function(points_to)) {
-               if (!(c_mode && _GNUC)) {
+               if (!GNU_MODE) {
                        errorf(source_position,
                               "arithmetic with pointer to function type '%T' not allowed",
                               orig_pointer_type);
@@ -7480,6 +7531,46 @@ static void semantic_unexpr_plus(unary_expression_t *expression)
                        "traditional C rejects the unary plus operator");
 }
 
+static expression_t const *get_reference_address(expression_t const *expr)
+{
+       bool regular_take_address = true;
+       for (;;) {
+               if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
+                       expr = expr->unary.value;
+               } else {
+                       regular_take_address = false;
+               }
+
+               if (expr->kind != EXPR_UNARY_DEREFERENCE)
+                       break;
+
+               expr = expr->unary.value;
+       }
+
+       if (expr->kind != EXPR_REFERENCE)
+               return NULL;
+
+       if (!regular_take_address &&
+           !is_type_function(skip_typeref(expr->reference.declaration->type))) {
+               return NULL;
+       }
+
+       return expr;
+}
+
+static void warn_function_address_as_bool(expression_t const* expr)
+{
+       if (!warning.address)
+               return;
+
+       expr = get_reference_address(expr);
+       if (expr != NULL) {
+               warningf(&expr->base.source_position,
+                       "the address of '%Y' will always evaluate as 'true'",
+                       expr->reference.declaration->symbol);
+       }
+}
+
 static void semantic_not(unary_expression_t *expression)
 {
        type_t *const orig_type = expression->value->base.type;
@@ -7489,6 +7580,8 @@ static void semantic_not(unary_expression_t *expression)
                       "operand of ! must be of scalar type");
        }
 
+       warn_function_address_as_bool(expression->value);
+
        expression->base.type = type_int;
 }
 
@@ -7836,6 +7929,22 @@ static void semantic_sub(binary_expression_t *expression)
        }
 }
 
+static void warn_string_literal_address(expression_t const* expr)
+{
+       while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
+               expr = expr->unary.value;
+               if (expr->kind != EXPR_UNARY_DEREFERENCE)
+                       return;
+               expr = expr->unary.value;
+       }
+
+       if (expr->kind == EXPR_STRING_LITERAL ||
+           expr->kind == EXPR_WIDE_STRING_LITERAL) {
+               warningf(&expr->base.source_position,
+                       "comparison with string literal results in unspecified behaviour");
+       }
+}
+
 /**
  * Check the semantics of comparison expressions.
  *
@@ -7843,13 +7952,32 @@ static void semantic_sub(binary_expression_t *expression)
  */
 static void semantic_comparison(binary_expression_t *expression)
 {
-       expression_t *left            = expression->left;
-       expression_t *right           = expression->right;
-       type_t       *orig_type_left  = left->base.type;
-       type_t       *orig_type_right = right->base.type;
+       expression_t *left  = expression->left;
+       expression_t *right = expression->right;
 
-       type_t *type_left  = skip_typeref(orig_type_left);
-       type_t *type_right = skip_typeref(orig_type_right);
+       if (warning.address) {
+               warn_string_literal_address(left);
+               warn_string_literal_address(right);
+
+               expression_t const* const func_left = get_reference_address(left);
+               if (func_left != NULL && is_null_pointer_constant(right)) {
+                       warningf(&expression->base.source_position,
+                               "the address of '%Y' will never be NULL",
+                               func_left->reference.declaration->symbol);
+               }
+
+               expression_t const* const func_right = get_reference_address(right);
+               if (func_right != NULL && is_null_pointer_constant(right)) {
+                       warningf(&expression->base.source_position,
+                               "the address of '%Y' will never be NULL",
+                               func_right->reference.declaration->symbol);
+               }
+       }
+
+       type_t *orig_type_left  = left->base.type;
+       type_t *orig_type_right = right->base.type;
+       type_t *type_left       = skip_typeref(orig_type_left);
+       type_t *type_right      = skip_typeref(orig_type_right);
 
        /* TODO non-arithmetic types */
        if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
@@ -8042,6 +8170,9 @@ static void semantic_logical_op(binary_expression_t *expression)
        type_t       *const type_left       = skip_typeref(orig_type_left);
        type_t       *const type_right      = skip_typeref(orig_type_right);
 
+       warn_function_address_as_bool(left);
+       warn_function_address_as_bool(right);
+
        if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
                /* TODO: improve error message */
                if (is_type_valid(type_left) && is_type_valid(type_right)) {
@@ -8665,7 +8796,7 @@ static statement_t *parse_case_statement(void)
                statement->case_label.last_case  = val;
        }
 
-       if (c_mode & _GNUC) {
+       if (GNU_MODE) {
                if (token.type == T_DOTDOTDOT) {
                        next_token();
                        expression_t *const end_range   = parse_expression();
@@ -9053,9 +9184,8 @@ static statement_t *parse_for(void)
 
        PUSH_PARENT(statement);
 
-       int      top        = environment_top();
-       scope_t *last_scope = scope;
-       set_scope(&statement->fors.scope);
+       size_t const top = environment_top();
+       scope_push(&statement->fors.scope);
 
        expect('(');
        add_anchor_token(')');
@@ -9097,7 +9227,7 @@ static statement_t *parse_for(void)
        statement->fors.body = parse_loop_body(statement);
 
        assert(scope == &statement->fors.scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
 
        POP_PARENT;
@@ -9107,7 +9237,7 @@ end_error:
        POP_PARENT;
        rem_anchor_token(')');
        assert(scope == &statement->fors.scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
 
        return create_invalid_statement();
@@ -9122,7 +9252,7 @@ static statement_t *parse_goto(void)
        eat(T_goto);
 
        statement_t *statement;
-       if (c_mode & _GNUC && token.type == '*') {
+       if (GNU_MODE && token.type == '*') {
                next_token();
                expression_t *expression = parse_expression();
 
@@ -9145,11 +9275,11 @@ static statement_t *parse_goto(void)
                statement->gotos.expression     = expression;
        } else {
                if (token.type != T_IDENTIFIER) {
-                       if (c_mode & _GNUC)
+                       if (GNU_MODE)
                                parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
                        else
                                parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
-                       eat_statement();
+                       eat_until_anchor();
                        goto end_error;
                }
                symbol_t *symbol = token.v.symbol;
@@ -9158,6 +9288,10 @@ static statement_t *parse_goto(void)
                statement                       = allocate_statement_zero(STATEMENT_GOTO);
                statement->base.source_position = source_position;
                statement->gotos.label          = get_label(symbol);
+
+               if (statement->gotos.label->parent_scope->depth < current_function->scope.depth) {
+                       statement->gotos.outer_fkt_jmp = true;
+               }
        }
 
        /* remember the goto's in a list for later checking */
@@ -9357,7 +9491,10 @@ static statement_t *parse_declaration_statement(void)
        statement->base.source_position = token.source_position;
 
        declaration_t *before = last_declaration;
-       parse_declaration(record_declaration);
+       if (GNU_MODE)
+               parse_external_declaration();
+       else
+               parse_declaration(record_declaration);
 
        if (before == NULL) {
                statement->declaration.declarations_begin = scope->declarations;
@@ -9535,7 +9672,10 @@ expression_statment:
                do {
                        next_token();
                } while (token.type == T___extension__);
+               bool old_gcc_extension = in_gcc_extension;
+               in_gcc_extension       = true;
                statement = parse_statement();
+               in_gcc_extension = old_gcc_extension;
                break;
 
        DECLARATION_START
@@ -9657,10 +9797,9 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
        eat('{');
        add_anchor_token('}');
 
-       int      top        = environment_top();
-       int      top_local  = local_label_top();
-       scope_t *last_scope = scope;
-       set_scope(&statement->compound.scope);
+       size_t const top       = environment_top();
+       size_t const top_local = local_label_top();
+       scope_push(&statement->compound.scope);
 
        statement_t **anchor            = &statement->compound.statements;
        bool          only_decls_so_far = true;
@@ -9719,7 +9858,7 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
 end_error:
        rem_anchor_token('}');
        assert(scope == &statement->compound.scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
        local_label_pop_to(top_local);
 
@@ -9813,15 +9952,20 @@ static void parse_translation_unit(void)
        for (;;) {
 #ifndef NDEBUG
                bool anchor_leak = false;
-               for (token_type_t i = 0; i != T_LAST_TOKEN; ++i) {
+               for (int i = 0; i != T_LAST_TOKEN; ++i) {
                        unsigned char count = token_anchor_set[i];
                        if (count != 0) {
                                errorf(HERE, "Leaked anchor token %k %d times", i, count);
                                anchor_leak = true;
                        }
                }
+               if (in_gcc_extension) {
+                       errorf(HERE, "Leaked __extension__");
+                       anchor_leak = true;
+               }
+
                if (anchor_leak)
-                       exit(1);
+                       abort();
 #endif
 
                switch (token.type) {
@@ -9878,15 +10022,16 @@ void start_parsing(void)
        global_scope = &unit->scope;
 
        assert(scope == NULL);
-       set_scope(&unit->scope);
+       scope_push(&unit->scope);
 
        initialize_builtin_types();
 }
 
 translation_unit_t *finish_parsing(void)
 {
+       /* do NOT use scope_pop() here, this will crash, will it by hand */
        assert(scope == &unit->scope);
-       scope          = NULL;
+       scope            = NULL;
        last_declaration = NULL;
 
        assert(global_scope == &unit->scope);