The standard calls it "file scope", so rename global_scope to file_scope.
[cparser] / parser.c
index 77c5884..14a84c4 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;
-static scope_t            *global_scope      = NULL;
+/** The global file scope. */
+static scope_t            *file_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);
@@ -625,13 +640,9 @@ check_stop:
  */
 static void eat_until_anchor(void)
 {
-       if (token.type == T_EOF)
-               return;
        while (token_anchor_set[token.type] == 0) {
                if (token.type == '(' || token.type == '{' || token.type == '[')
                        eat_until_matching_token(token.type);
-               if (token.type == T_EOF)
-                       break;
                next_token();
        }
 }
@@ -701,16 +712,25 @@ 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.
@@ -737,28 +757,20 @@ 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;
@@ -823,30 +835,20 @@ 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);
@@ -2853,16 +2855,16 @@ 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();
@@ -2881,6 +2883,8 @@ restart:
                type       = expression->base.type;
                break;
        }
+       in_type_prop     = old_type_prop;
+       in_gcc_extension = old_gcc_extension;
 
        rem_anchor_token(')');
        expect(')');
@@ -2953,7 +2957,7 @@ 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;
        }
@@ -3024,7 +3028,7 @@ 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;
@@ -3108,7 +3112,7 @@ static declaration_t *create_error_declaration(symbol_t *symbol, storage_class_t
        decl->source_position        = *HERE;
        decl->declared_storage_class = storage_class;
        decl->storage_class          =
-               storage_class != STORAGE_CLASS_NONE || scope == global_scope ?
+               storage_class != STORAGE_CLASS_NONE || scope == file_scope ?
                        storage_class : STORAGE_CLASS_AUTO;
        decl->symbol                 = symbol;
        decl->implicit               = true;
@@ -3214,12 +3218,13 @@ 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;
 
@@ -3229,7 +3234,7 @@ 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)                                  \
@@ -3294,8 +3299,8 @@ 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 */
@@ -3359,8 +3364,8 @@ static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
                        type->compound.declaration = parse_compound_type_specifier(false);
                        if (type->compound.declaration->modifiers & DM_TRANSPARENT_UNION)
                                modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
-                       break;
                        finish_union_type(&type->compound);
+                       break;
                }
                case T_enum:
                        type = parse_enum_specifier();
@@ -3440,6 +3445,8 @@ 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;
 
@@ -3657,7 +3664,13 @@ 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;
@@ -3681,6 +3694,7 @@ static declaration_t *parse_identifier_list(void)
                next_token();
        } while (token.type == T_IDENTIFIER);
 
+       *last = last_declaration;
        return declarations;
 }
 
@@ -3733,7 +3747,13 @@ 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;
 
@@ -3746,7 +3766,7 @@ 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;
                }
        }
@@ -3812,10 +3832,12 @@ 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;
 }
 
@@ -3951,9 +3973,12 @@ 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 =
@@ -4234,8 +4259,8 @@ static declaration_t *parse_declarator(
        declaration->is_inline              = specifiers->is_inline;
 
        declaration->storage_class          = specifiers->declared_storage_class;
-       if (declaration->storage_class == STORAGE_CLASS_NONE
-                       && scope != global_scope) {
+       if (declaration->storage_class == STORAGE_CLASS_NONE &&
+           scope != file_scope) {
                declaration->storage_class = STORAGE_CLASS_AUTO;
        }
 
@@ -4371,14 +4396,23 @@ static declaration_t *record_declaration(
 
        if (warning.nested_externs                             &&
            declaration->storage_class == STORAGE_CLASS_EXTERN &&
-           scope                      != global_scope) {
+           scope                      != file_scope) {
                warningf(&declaration->source_position,
                         "nested extern declaration of '%#T'", declaration->type, symbol);
        }
 
        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;
@@ -4502,7 +4536,7 @@ warn_redundant_declaration:
                }
        } else {
                if (warning.missing_declarations &&
-                   scope == global_scope && (
+                   scope == file_scope && (
                      declaration->storage_class == STORAGE_CLASS_NONE ||
                      declaration->storage_class == STORAGE_CLASS_THREAD
                    )) {
@@ -4510,7 +4544,7 @@ warn_redundant_declaration:
                                 "no previous declaration for '%#T'", orig_type, symbol);
                }
        }
-
+finish:
        assert(declaration->parent_scope == NULL);
        assert(scope != NULL);
 
@@ -4530,7 +4564,7 @@ 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;
@@ -4558,9 +4592,9 @@ static void parse_init_declarator_rest(declaration_t *declaration)
        }
 
        bool must_be_constant = false;
-       if (declaration->storage_class == STORAGE_CLASS_STATIC
-                       || declaration->storage_class == STORAGE_CLASS_THREAD_STATIC
-                       || declaration->parent_scope == global_scope) {
+       if (declaration->storage_class == STORAGE_CLASS_STATIC        ||
+           declaration->storage_class == STORAGE_CLASS_THREAD_STATIC ||
+           declaration->parent_scope  == file_scope) {
                must_be_constant = true;
        }
 
@@ -4634,7 +4668,6 @@ 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 =
@@ -4658,13 +4691,14 @@ 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(',');
 }
 
@@ -4743,10 +4777,11 @@ 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) {
@@ -4762,7 +4797,7 @@ 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 */
@@ -4821,6 +4856,8 @@ static void parse_kr_declaration_list(declaration_t *declaration)
        }
 
        declaration->type = type;
+
+       rem_anchor_token('{');
 }
 
 static bool first_err = true;
@@ -5381,13 +5418,15 @@ 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) {
@@ -5456,9 +5495,8 @@ 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) {
@@ -5513,7 +5551,7 @@ static void parse_external_declaration(void)
        }
 
        assert(scope == &declaration->scope);
-       set_scope(last_scope);
+       scope_pop();
        environment_pop_to(top);
 }
 
@@ -5678,7 +5716,11 @@ static void parse_compound_type_entries(declaration_t *compound_declaration)
        eat('{');
        add_anchor_token('}');
 
-       while (token.type != '}' && token.type != T_EOF) {
+       while (token.type != '}') {
+               if (token.type == T_EOF) {
+                       errorf(HERE, "EOF while parsing struct");
+                       break;
+               }
                declaration_specifiers_t specifiers;
                memset(&specifiers, 0, sizeof(specifiers));
                parse_declaration_specifiers(&specifiers);
@@ -5686,10 +5728,6 @@ static void parse_compound_type_entries(declaration_t *compound_declaration)
                parse_compound_declarators(compound_declaration, &specifiers);
        }
        rem_anchor_token('}');
-
-       if (token.type == T_EOF) {
-               errorf(HERE, "EOF while parsing struct");
-       }
        next_token();
 }
 
@@ -5818,8 +5856,7 @@ 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");
@@ -5842,8 +5879,7 @@ 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");
@@ -6091,11 +6127,11 @@ 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;
@@ -6103,6 +6139,15 @@ static expression_t *parse_reference(void)
        /* this declaration is used */
        declaration->used = true;
 
+       if (declaration->parent_scope != file_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) {
@@ -6118,7 +6163,7 @@ 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);
@@ -6594,7 +6639,6 @@ static expression_t *parse_compare_builtin(void)
                break;
        default:
                internal_errorf(HERE, "invalid compare builtin found");
-               break;
        }
        expression->base.source_position = *HERE;
        next_token();
@@ -6684,7 +6728,10 @@ 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;
        }
 
@@ -6814,7 +6861,7 @@ 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;
 
@@ -6905,10 +6952,9 @@ static expression_t *parse_typeprop(expression_kind_t const kind,
 
        char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
 
-       /* we only refer to a type property, not the value, so do not warn
-        * when using current_init_decl */
-       declaration_t *old = current_init_decl;
-       current_init_decl  = NULL;
+       /* 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(')');
@@ -6949,7 +6995,7 @@ static expression_t *parse_typeprop(expression_kind_t const kind,
        }
 
 end_error:
-       current_init_decl  = old;
+       in_type_prop = old;
        return tp_expression;
 }
 
@@ -7247,7 +7293,7 @@ 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();
@@ -7358,9 +7404,10 @@ 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;
 }
 
@@ -7394,7 +7441,7 @@ 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);
@@ -7405,7 +7452,7 @@ 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);
@@ -7479,6 +7526,46 @@ 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;
@@ -7488,6 +7575,8 @@ 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;
 }
 
@@ -7835,6 +7924,22 @@ 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.
  *
@@ -7842,13 +7947,32 @@ 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)) {
@@ -8041,6 +8165,9 @@ 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)) {
@@ -8664,7 +8791,7 @@ 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();
@@ -9052,9 +9179,8 @@ 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(')');
@@ -9096,7 +9222,7 @@ 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;
@@ -9106,7 +9232,7 @@ 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();
@@ -9121,7 +9247,7 @@ 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();
 
@@ -9144,7 +9270,7 @@ 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);
@@ -9157,6 +9283,10 @@ 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 */
@@ -9356,7 +9486,7 @@ static statement_t *parse_declaration_statement(void)
        statement->base.source_position = token.source_position;
 
        declaration_t *before = last_declaration;
-       if (c_mode & _GNUC)
+       if (GNU_MODE)
                parse_external_declaration();
        else
                parse_declaration(record_declaration);
@@ -9537,7 +9667,10 @@ 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
@@ -9659,14 +9792,18 @@ 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;
-       while (token.type != '}' && token.type != T_EOF) {
+       while (token.type != '}') {
+               if (token.type == T_EOF) {
+                       errorf(&statement->base.source_position,
+                              "EOF while parsing compound statement");
+                       break;
+               }
                statement_t *sub_statement = intern_parse_statement();
                if (is_invalid_statement(sub_statement)) {
                        /* an error occurred. if we are at an anchor, return */
@@ -9691,13 +9828,7 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
 
                anchor = &sub_statement->base.next;
        }
-
-       if (token.type == '}') {
-               next_token();
-       } else {
-               errorf(&statement->base.source_position,
-                      "end of file while looking for closing '}'");
-       }
+       next_token();
 
        /* look over all statements again to produce no effect warnings */
        if (warning.unused_value) {
@@ -9721,7 +9852,7 @@ 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);
 
@@ -9764,7 +9895,7 @@ static void check_unused_globals(void)
        if (!warning.unused_function && !warning.unused_variable)
                return;
 
-       for (const declaration_t *decl = global_scope->declarations; decl != NULL; decl = decl->next) {
+       for (const declaration_t *decl = file_scope->declarations; decl != NULL; decl = decl->next) {
                if (decl->used                  ||
                    decl->modifiers & DM_UNUSED ||
                    decl->modifiers & DM_USED   ||
@@ -9812,16 +9943,27 @@ end_error:;
  */
 static void parse_translation_unit(void)
 {
+       add_anchor_token(T_EOF);
+
+#ifndef NDEBUG
+       unsigned char token_anchor_copy[T_LAST_TOKEN];
+       memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
+#endif
        for (;;) {
 #ifndef NDEBUG
                bool anchor_leak = false;
-               for (token_type_t i = 0; i != T_LAST_TOKEN; ++i) {
-                       unsigned char count = token_anchor_set[i];
+               for (int i = 0; i != T_LAST_TOKEN; ++i) {
+                       unsigned char count = token_anchor_set[i] - token_anchor_copy[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)
                        abort();
 #endif
@@ -9838,6 +9980,7 @@ static void parse_translation_unit(void)
                                break;
 
                        case T_EOF:
+                               rem_anchor_token(T_EOF);
                                return;
 
                        case ';':
@@ -9876,24 +10019,25 @@ void start_parsing(void)
        assert(unit == NULL);
        unit = allocate_ast_zero(sizeof(unit[0]));
 
-       assert(global_scope == NULL);
-       global_scope = &unit->scope;
+       assert(file_scope == NULL);
+       file_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);
+       assert(file_scope == &unit->scope);
        check_unused_globals();
-       global_scope = NULL;
+       file_scope = NULL;
 
        DEL_ARR_F(environment_stack);
        DEL_ARR_F(label_stack);