Parse __extension__ like GCC: External declarations may start with it.
[cparser] / parser.c
index 67f83ea..8717368 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -117,6 +117,21 @@ static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
        ((void)(current_parent = new_parent))
 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 
+#define PUSH_SCOPE(scope) \
+       size_t   const top       = environment_top(); \
+       scope_t *const new_scope = (scope); \
+       scope_t *const old_scope = scope_push(new_scope)
+#define POP_SCOPE() (assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top))
+
+#define PUSH_EXTENSION() \
+       bool const old_gcc_extension = in_gcc_extension; \
+       while (next_if(T___extension__)) { \
+               in_gcc_extension = true; \
+       } \
+       do {} while (0)
+#define POP_EXTENSION() \
+       ((void)(in_gcc_extension = old_gcc_extension))
+
 /** special symbol used for anonymous entities. */
 static symbol_t *sym_anonymous = NULL;
 
@@ -4529,9 +4544,7 @@ static void parse_kr_declaration_list(entity_t *entity)
 
        add_anchor_token('{');
 
-       /* push function parameters */
-       size_t const  top       = environment_top();
-       scope_t      *old_scope = scope_push(&entity->function.parameters);
+       PUSH_SCOPE(&entity->function.parameters);
 
        entity_t *parameter = entity->function.parameters.entities;
        for ( ; parameter != NULL; parameter = parameter->base.next) {
@@ -4557,10 +4570,7 @@ static void parse_kr_declaration_list(entity_t *entity)
        }
 decl_list_end:
 
-       /* pop function parameters */
-       assert(current_scope == &entity->function.parameters);
-       scope_pop(old_scope);
-       environment_pop_to(top);
+       POP_SCOPE();
 
        /* update function type */
        type_t *new_type = duplicate_type(type);
@@ -5463,9 +5473,7 @@ static void parse_external_declaration(void)
        assert(is_declaration(entity));
        type = skip_typeref(entity->declaration.type);
 
-       /* push function parameters and switch scope */
-       size_t const  top       = environment_top();
-       scope_t      *old_scope = scope_push(&function->parameters);
+       PUSH_SCOPE(&function->parameters);
 
        entity_t *parameter = function->parameters.entities;
        for (; parameter != NULL; parameter = parameter->base.next) {
@@ -5526,9 +5534,7 @@ static void parse_external_declaration(void)
                label_pop_to(label_stack_top);
        }
 
-       assert(current_scope == &function->parameters);
-       scope_pop(old_scope);
-       environment_pop_to(top);
+       POP_SCOPE();
 }
 
 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
@@ -7592,12 +7598,9 @@ types_incompatible:
  */
 static expression_t *parse_extension(void)
 {
-       eat(T___extension__);
-
-       bool old_gcc_extension   = in_gcc_extension;
-       in_gcc_extension         = true;
+       PUSH_EXTENSION();
        expression_t *expression = parse_subexpression(PREC_UNARY);
-       in_gcc_extension         = old_gcc_extension;
+       POP_EXTENSION();
        return expression;
 }
 
@@ -9102,7 +9105,8 @@ static statement_t *parse_label_inner_statement(statement_t const *const label,
 
                default:
                        inner_stmt = parse_statement();
-                       /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
+                       /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
+                       /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
                        if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
                                errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
                        }
@@ -9269,6 +9273,17 @@ static statement_t *parse_label_statement(void)
        return statement;
 }
 
+static statement_t *parse_inner_statement(void)
+{
+       statement_t *const stmt = parse_statement();
+       /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
+       /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
+       if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
+               errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
+       }
+       return stmt;
+}
+
 /**
  * Parse an if statement.
  */
@@ -9297,12 +9312,12 @@ end_error:
        rem_anchor_token('{');
 
        add_anchor_token(T_else);
-       statement_t *const true_stmt = parse_statement();
+       statement_t *const true_stmt = parse_inner_statement();
        statement->ifs.true_statement = true_stmt;
        rem_anchor_token(T_else);
 
        if (next_if(T_else)) {
-               statement->ifs.false_statement = parse_statement();
+               statement->ifs.false_statement = parse_inner_statement();
        } else if (true_stmt->kind == STATEMENT_IF &&
                        true_stmt->ifs.false_statement != NULL) {
                source_position_t const *const pos = &true_stmt->base.source_position;
@@ -9388,7 +9403,7 @@ static statement_t *parse_switch(void)
 
        switch_statement_t *rem = current_switch;
        current_switch          = &statement->switchs;
-       statement->switchs.body = parse_statement();
+       statement->switchs.body = parse_inner_statement();
        current_switch          = rem;
 
        if (statement->switchs.default_label == NULL) {
@@ -9408,7 +9423,7 @@ static statement_t *parse_loop_body(statement_t *const loop)
        statement_t *const rem = current_loop;
        current_loop = loop;
 
-       statement_t *const body = parse_statement();
+       statement_t *const body = parse_inner_statement();
 
        current_loop = rem;
        return body;
@@ -9493,14 +9508,9 @@ static statement_t *parse_for(void)
        add_anchor_token(')');
 
        PUSH_PARENT(statement);
+       PUSH_SCOPE(&statement->fors.scope);
 
-       size_t const  top       = environment_top();
-       scope_t      *old_scope = scope_push(&statement->fors.scope);
-
-       bool old_gcc_extension = in_gcc_extension;
-       while (next_if(T___extension__)) {
-               in_gcc_extension = true;
-       }
+       PUSH_EXTENSION();
 
        if (next_if(';')) {
        } else if (is_declaration_specifier(&token)) {
@@ -9516,7 +9526,8 @@ static statement_t *parse_for(void)
                rem_anchor_token(';');
                expect(';', end_error2);
        }
-       in_gcc_extension = old_gcc_extension;
+
+       POP_EXTENSION();
 
        if (token.type != ';') {
                add_anchor_token(';');
@@ -9541,19 +9552,14 @@ static statement_t *parse_for(void)
        rem_anchor_token(')');
        statement->fors.body = parse_loop_body(statement);
 
-       assert(current_scope == &statement->fors.scope);
-       scope_pop(old_scope);
-       environment_pop_to(top);
-
+       POP_SCOPE();
        POP_PARENT();
        return statement;
 
 end_error2:
        POP_PARENT();
        rem_anchor_token(')');
-       assert(current_scope == &statement->fors.scope);
-       scope_pop(old_scope);
-       environment_pop_to(top);
+       POP_SCOPE();
        /* fallthrough */
 
 end_error1:
@@ -9957,8 +9963,7 @@ static void parse_namespace_definition(void)
        environment_push(entity);
        append_entity(current_scope, entity);
 
-       size_t const  top       = environment_top();
-       scope_t      *old_scope = scope_push(&entity->namespacee.members);
+       PUSH_SCOPE(&entity->namespacee.members);
 
        entity_t     *old_current_entity = current_entity;
        current_entity = entity;
@@ -9968,11 +9973,9 @@ static void parse_namespace_definition(void)
        expect('}', end_error);
 
 end_error:
-       assert(current_scope == &entity->namespacee.members);
        assert(current_entity == entity);
        current_entity = old_current_entity;
-       scope_pop(old_scope);
-       environment_pop_to(top);
+       POP_SCOPE();
 }
 
 /**
@@ -10015,15 +10018,14 @@ static statement_t *intern_parse_statement(void)
                break;
        }
 
-       case T___extension__:
+       case T___extension__: {
                /* This can be a prefix to a declaration or an expression statement.
                 * We simply eat it now and parse the rest with tail recursion. */
-               while (next_if(T___extension__)) {}
-               bool old_gcc_extension = in_gcc_extension;
-               in_gcc_extension       = true;
+               PUSH_EXTENSION();
                statement = intern_parse_statement();
-               in_gcc_extension = old_gcc_extension;
+               POP_EXTENSION();
                break;
+       }
 
        DECLARATION_START
                statement = parse_declaration_statement();
@@ -10097,6 +10099,7 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
        statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
 
        PUSH_PARENT(statement);
+       PUSH_SCOPE(&statement->compound.scope);
 
        eat('{');
        add_anchor_token('}');
@@ -10189,9 +10192,6 @@ static statement_t *parse_compound_statement(bool inside_expression_statement)
        add_anchor_token(T_wchar_t);
        add_anchor_token(T_while);
 
-       size_t const  top       = environment_top();
-       scope_t      *old_scope = scope_push(&statement->compound.scope);
-
        statement_t **anchor            = &statement->compound.statements;
        bool          only_decls_so_far = true;
        while (token.type != '}') {
@@ -10330,10 +10330,8 @@ end_error:
        rem_anchor_token('&');
        rem_anchor_token('!');
        rem_anchor_token('}');
-       assert(current_scope == &statement->compound.scope);
-       scope_pop(old_scope);
-       environment_pop_to(top);
 
+       POP_SCOPE();
        POP_PARENT();
        return statement;
 }
@@ -10427,22 +10425,21 @@ end_error:
 static void parse_external(void)
 {
        switch (token.type) {
-               DECLARATION_START_NO_EXTERN
-               case T_IDENTIFIER:
-               case T___extension__:
-               /* tokens below are for implicit int */
-               case '&': /* & x; -> int& x; (and error later, because C++ has no
-                            implicit int) */
-               case '*': /* * x; -> int* x; */
-               case '(': /* (x); -> int (x); */
-                       parse_external_declaration();
-                       return;
-
                case T_extern:
                        if (look_ahead(1)->type == T_STRING_LITERAL) {
                                parse_linkage_specification();
                        } else {
+               DECLARATION_START_NO_EXTERN
+               case T_IDENTIFIER:
+               case T___extension__:
+               /* tokens below are for implicit int */
+               case '&':  /* & x; -> int& x; (and error later, because C++ has no
+                             implicit int) */
+               case '*':  /* * x; -> int* x; */
+               case '(':; /* (x); -> int (x); */
+                               PUSH_EXTENSION();
                                parse_external_declaration();
+                               POP_EXTENSION();
                        }
                        return;