Add the helper function create_Const_from_bool() to create 0/1 constant from a boolea...
[cparser] / parser.c
index 7a2f0cd..205aed1 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -130,7 +130,7 @@ static unsigned char token_anchor_set[T_LAST_TOKEN];
 static statement_t *parse_compound_statement(bool inside_expression_statement);
 static statement_t *parse_statement(void);
 
-static expression_t *parse_sub_expression(precedence_t);
+static expression_t *parse_subexpression(precedence_t);
 static expression_t *parse_expression(void);
 static type_t       *parse_typename(void);
 static void          parse_externals(void);
@@ -658,7 +658,7 @@ static void type_error_incompatible(const char *msg,
 /**
  * Expect the current token is the expected token.
  * If not, generate an error, eat the current statement,
- * and goto the end_error label.
+ * and goto the error_label label.
  */
 #define expect(expected, error_label)                     \
        do {                                                  \
@@ -823,7 +823,7 @@ static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
                }
        }
 
-       ARR_SHRINKLEN(*stack_ptr, (int) new_top);
+       ARR_SHRINKLEN(*stack_ptr, new_top);
 }
 
 /**
@@ -916,10 +916,13 @@ static bool is_null_pointer_constant(const expression_t *expression)
        }
 
        type_t *const type = skip_typeref(expression->base.type);
-       return
-               is_type_integer(type)              &&
-               is_constant_expression(expression) &&
-               !fold_constant_to_bool(expression);
+       if (!is_type_integer(type))
+               return false;
+       switch (is_constant_expression(expression)) {
+               case EXPR_CLASS_ERROR:    return true;
+               case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
+               default:                  return false;
+       }
 }
 
 /**
@@ -1055,8 +1058,8 @@ static assign_error_t semantic_assign(type_t *orig_type_left,
                        return ASSIGN_WARNING_POINTER_FROM_INT;
                }
        } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
-           (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
-               && is_type_pointer(type_right))) {
+                       (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
+                               && is_type_pointer(type_right))) {
                return ASSIGN_SUCCESS;
        } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
                        || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
@@ -1077,9 +1080,9 @@ static assign_error_t semantic_assign(type_t *orig_type_left,
 
 static expression_t *parse_constant_expression(void)
 {
-       expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
+       expression_t *result = parse_subexpression(PREC_CONDITIONAL);
 
-       if (!is_constant_expression(result)) {
+       if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
                errorf(&result->base.source_position,
                       "expression '%E' is not constant", result);
        }
@@ -1089,7 +1092,7 @@ static expression_t *parse_constant_expression(void)
 
 static expression_t *parse_assignment_expression(void)
 {
-       return parse_sub_expression(PREC_ASSIGNMENT);
+       return parse_subexpression(PREC_ASSIGNMENT);
 }
 
 static void warn_string_concat(const source_position_t *pos)
@@ -1261,7 +1264,7 @@ static attribute_t *parse_attribute_gnu_single(void)
        symbol_t *symbol = get_symbol_from_token();
        if (symbol == NULL) {
                parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
-               goto end_error;
+               return NULL;
        }
 
        const char *name = symbol->string;
@@ -1290,9 +1293,6 @@ static attribute_t *parse_attribute_gnu_single(void)
                attribute->a.arguments = parse_attribute_arguments();
 
        return attribute;
-
-end_error:
-       return NULL;
 }
 
 static attribute_t *parse_attribute_gnu(void)
@@ -1735,8 +1735,9 @@ static initializer_t *initializer_from_expression(type_t *orig_type,
  */
 static bool is_initializer_constant(const expression_t *expression)
 {
-       return is_constant_expression(expression)
-               || is_address_constant(expression);
+       return
+               is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
+               is_address_constant(expression)    != EXPR_CLASS_VARIABLE;
 }
 
 /**
@@ -1967,7 +1968,7 @@ static bool walk_designator(type_path_t *path, const designator_t *designator,
                                        type_t *real_type = skip_typeref(iter->declaration.type);
                                        if (real_type->kind == TYPE_BITFIELD) {
                                                errorf(&designator->source_position,
-                                                      "offsetof designator '%Y' may not specify bitfield",
+                                                      "offsetof designator '%Y' must not specify bitfield",
                                                       symbol);
                                                goto failed;
                                        }
@@ -1999,8 +2000,8 @@ static bool walk_designator(type_path_t *path, const designator_t *designator,
                                        long array_size = type->array.size;
                                        if (index >= array_size) {
                                                errorf(&designator->source_position,
-                                                      "designator [%E] (%d) exceeds array size %d",
-                                                      array_index, index, array_size);
+                                                      "designator [%E] (%d) exceeds array size %d",
+                                                      array_index, index, array_size);
                                        }
                                }
                        }
@@ -2634,21 +2635,14 @@ static type_t *parse_typeof(void)
        switch (token.type) {
        case T_IDENTIFIER:
                if (is_typedef_symbol(token.symbol)) {
+       TYPENAME_START
                        type = parse_typename();
                } else {
+       default:
                        expression = parse_expression();
                        type       = revert_automatic_type_conversion(expression);
                }
                break;
-
-       TYPENAME_START
-               type = parse_typename();
-               break;
-
-       default:
-               expression = parse_expression();
-               type       = expression->base.type;
-               break;
        }
        in_type_prop     = old_type_prop;
        in_gcc_extension = old_gcc_extension;
@@ -2895,10 +2889,10 @@ check_thread_storage_class:
                                                break;
 
                                                char const* wrong;
-                                       case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
-                                       case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
-                                       case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
-wrong_thread_stoarge_class:
+                                       case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
+                                       case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
+                                       case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
+wrong_thread_storage_class:
                                                errorf(HERE, "'__thread' used with '%s'", wrong);
                                                break;
                                }
@@ -3494,54 +3488,64 @@ union construct_type_t {
        parsed_array_t            array;
 };
 
+static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
+{
+       construct_type_t *const cons = obstack_alloc(&temp_obst, size);
+       memset(cons, 0, size);
+       cons->kind = kind;
+       return cons;
+}
+
+/* §6.7.5.1 */
 static construct_type_t *parse_pointer_declarator(void)
 {
        eat('*');
 
-       parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
-       memset(pointer, 0, sizeof(pointer[0]));
-       pointer->base.kind       = CONSTRUCT_POINTER;
-       pointer->type_qualifiers = parse_type_qualifiers();
-       //pointer->base_variable       = base_variable;
+       construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
+       cons->pointer.type_qualifiers = parse_type_qualifiers();
+       //cons->pointer.base_variable   = base_variable;
 
-       return (construct_type_t*) pointer;
+       return cons;
 }
 
+/* ISO/IEC 14882:1998(E) §8.3.2 */
 static construct_type_t *parse_reference_declarator(void)
 {
        eat('&');
 
-       construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
-       parsed_reference_t *reference = &cons->reference;
-       memset(reference, 0, sizeof(*reference));
-       cons->kind = CONSTRUCT_REFERENCE;
+       if (!(c_mode & _CXX))
+               errorf(HERE, "references are only available for C++");
+
+       construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
 
        return cons;
 }
 
+/* §6.7.5.2 */
 static construct_type_t *parse_array_declarator(void)
 {
        eat('[');
        add_anchor_token(']');
 
-       construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
-       parsed_array_t   *array = &cons->array;
-       memset(array, 0, sizeof(*array));
-       cons->kind = CONSTRUCT_ARRAY;
+       construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
+       parsed_array_t   *const array = &cons->array;
 
-       if (next_if(T_static))
-               array->is_static = true;
+       bool is_static = next_if(T_static);
 
        type_qualifiers_t type_qualifiers = parse_type_qualifiers();
-       if (type_qualifiers != 0 && next_if(T_static))
-                       array->is_static = true;
+
+       if (!is_static)
+               is_static = next_if(T_static);
+
        array->type_qualifiers = type_qualifiers;
+       array->is_static       = is_static;
 
+       expression_t *size = NULL;
        if (token.type == '*' && look_ahead(1)->type == ']') {
                array->is_variable = true;
                next_token();
        } else if (token.type != ']') {
-               expression_t *const size = parse_assignment_expression();
+               size = parse_assignment_expression();
 
                /* §6.7.5.2:1  Array size must have integer type */
                type_t *const orig_type = size->base.type;
@@ -3556,6 +3560,9 @@ static construct_type_t *parse_array_declarator(void)
                mark_vars_read(size, NULL);
        }
 
+       if (is_static && size == NULL)
+               errorf(HERE, "static array parameters require a size");
+
        rem_anchor_token(']');
        expect(']', end_error);
 
@@ -3563,6 +3570,7 @@ end_error:
        return cons;
 }
 
+/* §6.7.5.3 */
 static construct_type_t *parse_function_declarator(scope_t *scope)
 {
        type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
@@ -3573,11 +3581,8 @@ static construct_type_t *parse_function_declarator(scope_t *scope)
 
        parse_parameters(ftype, scope);
 
-       construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
-       construct_function_type_t *function = &cons->function;
-       memset(function, 0, sizeof(*function));
-       cons->kind              = CONSTRUCT_FUNCTION;
-       function->function_type = type;
+       construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
+       cons->function.function_type = type;
 
        return cons;
 }
@@ -3592,6 +3597,7 @@ typedef struct parse_declarator_env_t {
        attribute_t       *attributes;
 } parse_declarator_env_t;
 
+/* §6.7.5 */
 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
 {
        /* construct a single linked list of construct_type_t's which describe
@@ -3606,8 +3612,6 @@ static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
                //variable_t       *based = NULL; /* MS __based extension */
                switch (token.type) {
                        case '&':
-                               if (!(c_mode & _CXX))
-                                       errorf(HERE, "references are only available for C++");
                                type = parse_reference_declarator();
                                break;
 
@@ -3658,12 +3662,16 @@ ptr_operator_end: ;
                        }
                        rem_anchor_token(')');
                        expect(')', end_error);
+               } else if (!env->may_be_abstract) {
+                       errorf(HERE, "declarator must have a name");
+                       goto error_out;
                }
                break;
        default:
                if (env->may_be_abstract)
                        break;
                parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
+error_out:
                eat_until_anchor();
                return NULL;
        }
@@ -3775,24 +3783,31 @@ static type_t *construct_declarator_type(construct_type_t *construct_list,
                        array_type->array.size_expression = size_expression;
 
                        if (size_expression != NULL) {
-                               if (is_constant_expression(size_expression)) {
-                                       long const size
-                                               = fold_constant_to_int(size_expression);
-                                       array_type->array.size          = size;
-                                       array_type->array.size_constant = true;
-                                       /* §6.7.5.2:1  If the expression is a constant expression, it shall
-                                        * have a value greater than zero. */
-                                       if (size <= 0) {
-                                               if (size < 0 || !GNU_MODE) {
-                                                       errorf(&size_expression->base.source_position,
-                                                                       "size of array must be greater than zero");
-                                               } else if (warning.other) {
-                                                       warningf(&size_expression->base.source_position,
-                                                                       "zero length arrays are a GCC extension");
+                               switch (is_constant_expression(size_expression)) {
+                                       case EXPR_CLASS_CONSTANT: {
+                                               long const size = fold_constant_to_int(size_expression);
+                                               array_type->array.size          = size;
+                                               array_type->array.size_constant = true;
+                                               /* §6.7.5.2:1  If the expression is a constant expression, it shall
+                                                * have a value greater than zero. */
+                                               if (size <= 0) {
+                                                       if (size < 0 || !GNU_MODE) {
+                                                               errorf(&size_expression->base.source_position,
+                                                                               "size of array must be greater than zero");
+                                                       } else if (warning.other) {
+                                                               warningf(&size_expression->base.source_position,
+                                                                               "zero length arrays are a GCC extension");
+                                                       }
                                                }
+                                               break;
                                        }
-                               } else {
-                                       array_type->array.is_vla = true;
+
+                                       case EXPR_CLASS_VARIABLE:
+                                               array_type->array.is_vla = true;
+                                               break;
+
+                                       case EXPR_CLASS_ERROR:
+                                               break;
                                }
                        }
 
@@ -3927,10 +3942,10 @@ static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
                                bool in_function_scope = current_function != NULL;
 
                                if (specifiers->thread_local || (
-                                     specifiers->storage_class != STORAGE_CLASS_EXTERN &&
-                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
-                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
-                                  )) {
+                                                       specifiers->storage_class != STORAGE_CLASS_EXTERN &&
+                                                       specifiers->storage_class != STORAGE_CLASS_NONE   &&
+                                                       (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
+                                               )) {
                                        errorf(&env.source_position,
                                                        "invalid storage class for function '%Y'", env.symbol);
                                }
@@ -4879,8 +4894,8 @@ static void check_declarations(void)
 static int determine_truth(expression_t const* const cond)
 {
        return
-               !is_constant_expression(cond) ? 0 :
-               fold_constant_to_bool(cond)   ? 1 :
+               is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
+               fold_constant_to_bool(cond)                         ? 1 :
                -1;
 }
 
@@ -5090,7 +5105,7 @@ static void check_reachable(statement_t *const stmt)
                        if (!expression_returns(expr))
                                return;
 
-                       if (is_constant_expression(expr)) {
+                       if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
                                long                    const val      = fold_constant_to_int(expr);
                                case_label_statement_t *      defaults = NULL;
                                for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
@@ -5676,7 +5691,7 @@ static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
                bit_size = get_type_size(base_type) * 8;
        }
 
-       if (is_constant_expression(size)) {
+       if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
                long v = fold_constant_to_int(size);
                const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
 
@@ -5941,7 +5956,7 @@ static type_t *parse_typename(void)
                /* TODO: improve error message, user does probably not know what a
                 * storage class is...
                 */
-               errorf(HERE, "typename may not have a storage class");
+               errorf(HERE, "typename must not have a storage class");
        }
 
        type_t *result = parse_abstract_declarator(specifiers.type);
@@ -6119,14 +6134,17 @@ static expression_t *parse_number_literal(void)
        case T_INTEGER:
                kind = EXPR_LITERAL_INTEGER;
                check_integer_suffix();
+               type = type_int;
                break;
        case T_INTEGER_OCTAL:
                kind = EXPR_LITERAL_INTEGER_OCTAL;
                check_integer_suffix();
+               type = type_int;
                break;
        case T_INTEGER_HEXADECIMAL:
                kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
                check_integer_suffix();
+               type = type_int;
                break;
        case T_FLOATINGPOINT:
                kind = EXPR_LITERAL_FLOATINGPOINT;
@@ -6540,7 +6558,7 @@ static expression_t *parse_cast(void)
        expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
        cast->base.source_position = source_position;
 
-       expression_t *value = parse_sub_expression(PREC_CAST);
+       expression_t *value = parse_subexpression(PREC_CAST);
        cast->base.type   = type;
        cast->unary.value = value;
 
@@ -7147,6 +7165,7 @@ static expression_t *parse_primary_expression(void)
        }
 
        errorf(HERE, "unexpected token %K, expected an expression", &token);
+       eat_until_anchor();
        return create_invalid_expression();
 }
 
@@ -7239,7 +7258,7 @@ static expression_t *parse_typeprop(expression_kind_t const kind)
                        goto typeprop_expression;
                }
        } else {
-               expression = parse_sub_expression(PREC_UNARY);
+               expression = parse_subexpression(PREC_UNARY);
 
 typeprop_expression:
                tp_expression->typeprop.tp_expression = expression;
@@ -7408,20 +7427,33 @@ static void handle_builtin_argument_restrictions(call_expression_t *call) {
                        /* argument must be constant */
                        call_argument_t *argument = call->arguments;
 
-                       if (! is_constant_expression(argument->expression)) {
+                       if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
                                errorf(&call->base.source_position,
                                       "argument of '%Y' must be a constant expression",
                                       call->function->reference.entity->base.symbol);
                        }
                        break;
                }
-               case bk_gnu_builtin_prefetch: {
+               case bk_gnu_builtin_object_size:
+                       if (call->arguments == NULL)
+                               break;
+
+                       call_argument_t *arg = call->arguments->next;
+                       if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
+                               errorf(&call->base.source_position,
+                                          "second argument of '%Y' must be a constant expression",
+                                          call->function->reference.entity->base.symbol);
+                       }
+                       break;
+               case bk_gnu_builtin_prefetch:
                        /* second and third argument must be constant if existent */
+                       if (call->arguments == NULL)
+                               break;
                        call_argument_t *rw = call->arguments->next;
                        call_argument_t *locality = NULL;
 
                        if (rw != NULL) {
-                               if (! is_constant_expression(rw->expression)) {
+                               if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
                                        errorf(&call->base.source_position,
                                               "second argument of '%Y' must be a constant expression",
                                               call->function->reference.entity->base.symbol);
@@ -7429,7 +7461,7 @@ static void handle_builtin_argument_restrictions(call_expression_t *call) {
                                locality = rw->next;
                        }
                        if (locality != NULL) {
-                               if (! is_constant_expression(locality->expression)) {
+                               if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
                                        errorf(&call->base.source_position,
                                               "third argument of '%Y' must be a constant expression",
                                               call->function->reference.entity->base.symbol);
@@ -7437,7 +7469,6 @@ static void handle_builtin_argument_restrictions(call_expression_t *call) {
                                locality = rw->next;
                        }
                        break;
-               }
                default:
                        break;
        }
@@ -7514,6 +7545,10 @@ static expression_t *parse_call_expression(expression_t *expression)
        /* do default promotion for other arguments */
        for (; argument != NULL; argument = argument->next) {
                type_t *type = argument->expression->base.type;
+               if (!is_type_object(skip_typeref(type))) {
+                       errorf(&argument->expression->base.source_position,
+                              "call argument '%E' must not be void", argument->expression);
+               }
 
                type = get_default_promoted_type(type);
 
@@ -7646,7 +7681,7 @@ static expression_t *parse_conditional_expression(expression_t *expression)
        expect(':', end_error);
 end_error:;
        expression_t *false_expression =
-               parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
+               parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
 
        type_t *const orig_true_type  = true_expression->base.type;
        type_t *const orig_false_type = false_expression->base.type;
@@ -7675,13 +7710,6 @@ end_error:;
        } else if (is_type_arithmetic(true_type)
                   && is_type_arithmetic(false_type)) {
                result_type = semantic_arithmetic(true_type, false_type);
-
-               true_expression  = create_implicit_cast(true_expression, result_type);
-               false_expression = create_implicit_cast(false_expression, result_type);
-
-               conditional->true_expression  = true_expression;
-               conditional->false_expression = false_expression;
-               conditional->base.type        = result_type;
        } else if (same_compound_type(true_type, false_type)) {
                /* just take 1 of the 2 types */
                result_type = true_type;
@@ -7733,7 +7761,7 @@ end_error:;
                        result_type = pointer_type;
                } else {
                        if (is_type_valid(other_type)) {
-                               type_error_incompatible("while parsing conditional",
+                               type_error_incompatible("while parsing conditional",
                                                &expression->base.source_position, true_type, false_type);
                        }
                        result_type = type_error_type;
@@ -7764,7 +7792,7 @@ static expression_t *parse_extension(void)
 
        bool old_gcc_extension   = in_gcc_extension;
        in_gcc_extension         = true;
-       expression_t *expression = parse_sub_expression(PREC_UNARY);
+       expression_t *expression = parse_subexpression(PREC_UNARY);
        in_gcc_extension         = old_gcc_extension;
        return expression;
 }
@@ -7808,7 +7836,7 @@ static expression_t *parse_delete(void)
 end_error:;
        }
 
-       expression_t *const value = parse_sub_expression(PREC_CAST);
+       expression_t *const value = parse_subexpression(PREC_CAST);
        result->unary.value = value;
 
        type_t *const type = skip_typeref(value->base.type);
@@ -8072,7 +8100,7 @@ static expression_t *parse_##unexpression_type(void)                         \
        expression_t *unary_expression                                           \
                = allocate_expression_zero(unexpression_type);                       \
        eat(token_type);                                                         \
-       unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
+       unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
                                                                                 \
        sfunc(&unary_expression->unary);                                         \
                                                                                 \
@@ -8216,8 +8244,8 @@ static void warn_div_by_zero(binary_expression_t const *const expression)
 
        expression_t const *const right = expression->right;
        /* The type of the right operand can be different for /= */
-       if (is_type_integer(right->base.type) &&
-           is_constant_expression(right)     &&
+       if (is_type_integer(right->base.type)                    &&
+           is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
            !fold_constant_to_bool(right)) {
                warningf(&expression->base.source_position, "division by zero");
        }
@@ -8268,7 +8296,7 @@ static bool semantic_shift(binary_expression_t *expression)
 
        type_left = promote_integer(type_left);
 
-       if (is_constant_expression(right)) {
+       if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
                long count = fold_constant_to_int(right);
                if (count < 0) {
                        warningf(&right->base.source_position,
@@ -8416,9 +8444,11 @@ static void warn_comparison_in_comparison(const expression_t *const expr)
 
 static bool maybe_negative(expression_t const *const expr)
 {
-       return
-               !is_constant_expression(expr) ||
-               fold_constant_to_int(expr) < 0;
+       switch (is_constant_expression(expr)) {
+               case EXPR_CLASS_ERROR:    return false;
+               case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
+               default:                  return true;
+       }
 }
 
 /**
@@ -8886,7 +8916,7 @@ static expression_t *parse_##binexpression_type(expression_t *left)          \
        binexpr->binary.left  = left;                                            \
        eat(token_type);                                                         \
                                                                              \
-       expression_t *right = parse_sub_expression(prec_r);                      \
+       expression_t *right = parse_subexpression(prec_r);                       \
                                                                              \
        binexpr->binary.right = right;                                           \
        sfunc(&binexpr->binary);                                                 \
@@ -8926,7 +8956,7 @@ CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PR
 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
 
 
-static expression_t *parse_sub_expression(precedence_t precedence)
+static expression_t *parse_subexpression(precedence_t precedence)
 {
        if (token.type < 0) {
                return expected_expression_error();
@@ -8971,7 +9001,7 @@ static expression_t *parse_sub_expression(precedence_t precedence)
  */
 static expression_t *parse_expression(void)
 {
-       return parse_sub_expression(PREC_EXPRESSION);
+       return parse_subexpression(PREC_EXPRESSION);
 }
 
 /**
@@ -9213,9 +9243,13 @@ static statement_t *parse_asm_statement(void)
 
        expect('(', end_error);
        add_anchor_token(')');
-       add_anchor_token(':');
+       if (token.type != T_STRING_LITERAL) {
+               parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
+               goto end_of_asm;
+       }
        asm_statement->asm_text = parse_string_literals();
 
+       add_anchor_token(':');
        if (!next_if(':')) {
                rem_anchor_token(':');
                goto end_of_asm;
@@ -9252,6 +9286,36 @@ end_error:
        return create_invalid_statement();
 }
 
+static statement_t *parse_label_inner_statement(char const *const label, bool const eat_empty_stmt)
+{
+       statement_t *inner_stmt;
+       switch (token.type) {
+               case '}':
+                       errorf(HERE, "%s at end of compound statement", label);
+                       inner_stmt = create_invalid_statement();
+                       break;
+
+               case ';':
+                       if (eat_empty_stmt) {
+                               /* Eat an empty statement here, to avoid the warning about an empty
+                                * statement after a label.  label:; is commonly used to have a label
+                                * before a closing brace. */
+                               inner_stmt = create_empty_statement();
+                               next_token();
+                               break;
+                       }
+                       /* FALLTHROUGH */
+
+               default:
+                       inner_stmt = parse_statement();
+                       if (inner_stmt->kind == STATEMENT_DECLARATION) {
+                               errorf(&inner_stmt->base.source_position, "declaration after %s", label);
+                       }
+                       break;
+       }
+       return inner_stmt;
+}
+
 /**
  * Parse a case statement.
  */
@@ -9264,11 +9328,9 @@ static statement_t *parse_case_statement(void)
 
        expression_t *const expression   = parse_expression();
        statement->case_label.expression = expression;
-       if (!is_constant_expression(expression)) {
-               /* This check does not prevent the error message in all cases of an
-                * prior error while parsing the expression.  At least it catches the
-                * common case of a mistyped enum entry. */
-               if (is_type_valid(skip_typeref(expression->base.type))) {
+       expression_classification_t const expr_class = is_constant_expression(expression);
+       if (expr_class != EXPR_CLASS_CONSTANT) {
+               if (expr_class != EXPR_CLASS_ERROR) {
                        errorf(pos, "case label does not reduce to an integer constant");
                }
                statement->case_label.is_bad = true;
@@ -9282,11 +9344,9 @@ static statement_t *parse_case_statement(void)
                if (next_if(T_DOTDOTDOT)) {
                        expression_t *const end_range   = parse_expression();
                        statement->case_label.end_range = end_range;
-                       if (!is_constant_expression(end_range)) {
-                               /* This check does not prevent the error message in all cases of an
-                                * prior error while parsing the expression.  At least it catches the
-                                * common case of a mistyped enum entry. */
-                               if (is_type_valid(skip_typeref(end_range->base.type))) {
+                       expression_classification_t const end_class = is_constant_expression(end_range);
+                       if (end_class != EXPR_CLASS_CONSTANT) {
+                               if (end_class != EXPR_CLASS_ERROR) {
                                        errorf(pos, "case range does not reduce to an integer constant");
                                }
                                statement->case_label.is_bad = true;
@@ -9334,11 +9394,7 @@ end_error:
                errorf(pos, "case label not within a switch statement");
        }
 
-       statement_t *const inner_stmt = parse_statement();
-       statement->case_label.statement = inner_stmt;
-       if (inner_stmt->kind == STATEMENT_DECLARATION) {
-               errorf(&inner_stmt->base.source_position, "declaration after case label");
-       }
+       statement->case_label.statement = parse_label_inner_statement("case label", false);
 
        POP_PARENT;
        return statement;
@@ -9356,6 +9412,8 @@ static statement_t *parse_default_statement(void)
        PUSH_PARENT(statement);
 
        expect(':', end_error);
+end_error:
+
        if (current_switch != NULL) {
                const case_label_statement_t *def_label = current_switch->default_label;
                if (def_label != NULL) {
@@ -9377,17 +9435,10 @@ static statement_t *parse_default_statement(void)
                        "'default' label not within a switch statement");
        }
 
-       statement_t *const inner_stmt = parse_statement();
-       statement->case_label.statement = inner_stmt;
-       if (inner_stmt->kind == STATEMENT_DECLARATION) {
-               errorf(&inner_stmt->base.source_position, "declaration after default label");
-       }
+       statement->case_label.statement = parse_label_inner_statement("default label", false);
 
        POP_PARENT;
        return statement;
-end_error:
-       POP_PARENT;
-       return create_invalid_statement();
 }
 
 /**
@@ -9419,22 +9470,7 @@ static statement_t *parse_label_statement(void)
 
        eat(':');
 
-       if (token.type == '}') {
-               errorf(HERE, "label at end of compound statement");
-               statement->label.statement = create_invalid_statement();
-       } else if (token.type == ';') {
-               /* Eat an empty statement here, to avoid the warning about an empty
-                * statement after a label.  label:; is commonly used to have a label
-                * before a closing brace. */
-               statement->label.statement = create_empty_statement();
-               next_token();
-       } else {
-               statement_t *const inner_stmt = parse_statement();
-               statement->label.statement = inner_stmt;
-               if (inner_stmt->kind == STATEMENT_DECLARATION) {
-                       errorf(&inner_stmt->base.source_position, "declaration after label");
-               }
-       }
+       statement->label.statement = parse_label_inner_statement("label", true);
 
        /* remember the labels in a list for later checking */
        *label_anchor = &statement->label;
@@ -9781,7 +9817,7 @@ static statement_t *parse_goto(void)
                else
                        parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
                eat_until_anchor();
-               goto end_error;
+               return create_invalid_statement();
        }
 
        /* remember the goto's in a list for later checking */
@@ -9790,9 +9826,8 @@ static statement_t *parse_goto(void)
 
        expect(';', end_error);
 
-       return statement;
 end_error:
-       return create_invalid_statement();
+       return statement;
 }
 
 /**
@@ -10078,8 +10113,9 @@ static statement_t *parse_local_label_declaration(void)
 
        eat(T___label__);
 
-       entity_t *begin = NULL, *end = NULL;
-
+       entity_t *begin   = NULL;
+       entity_t *end     = NULL;
+       entity_t **anchor = &begin;
        do {
                if (token.type != T_IDENTIFIER) {
                        parse_error_expected("while parsing local label declaration",
@@ -10099,17 +10135,15 @@ static statement_t *parse_local_label_declaration(void)
                        entity->base.source_position = token.source_position;
                        entity->base.symbol          = symbol;
 
-                       if (end != NULL)
-                               end->base.next = entity;
-                       end = entity;
-                       if (begin == NULL)
-                               begin = entity;
+                       *anchor = entity;
+                       anchor  = &entity->base.next;
+                       end     = entity;
 
                        environment_push(entity);
                }
                next_token();
        } while (next_if(','));
-       eat(';');
+       expect(';', end_error);
 end_error:
        statement->declaration.declarations_begin = begin;
        statement->declaration.declarations_end   = end;
@@ -10199,18 +10233,14 @@ static statement_t *intern_parse_statement(void)
                        switch (la1_type) {
                        case '&':
                        case '*':
-                               if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL)
-                                       goto expression_statment;
-                               /* FALLTHROUGH */
-
+                               if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
+                       default:
+                                       statement = parse_expression_statement();
+                               } else {
                        DECLARATION_START
                        case T_IDENTIFIER:
-                               statement = parse_declaration_statement();
-                               break;
-
-                       default:
-expression_statment:
-                               statement = parse_expression_statement();
+                                       statement = parse_declaration_statement();
+                               }
                                break;
                        }
                }