static declaration_t *current_function = NULL;
static struct obstack temp_obst;
+/** The current source position. */
#define HERE token.source_position
static type_t *type_valist;
}
}
-/**
- * Called when we find a 2nd declarator for an identifier we already have a
- * declarator for.
- */
-static bool is_compatible_declaration(declaration_t *declaration,
- declaration_t *previous)
-{
- /* happens for K&R style function parameters */
- if(previous->type == NULL) {
- previous->type = declaration->type;
- return true;
- }
-
- type_t *type1 = skip_typeref(declaration->type);
- type_t *type2 = skip_typeref(previous->type);
-
- return types_compatible(type1, type2);
-}
-
/**
* Search a symbol in a given namespace and returns its declaration or
* NULL if this symbol was not found.
*/
-static declaration_t *get_declaration(symbol_t *symbol, namespace_t namespc)
+static declaration_t *get_declaration(const symbol_t *const symbol, const namespace_t namespc)
{
declaration_t *declaration = symbol->declaration;
for( ; declaration != NULL; declaration = declaration->symbol_next) {
return NULL;
}
-/**
- * Return the "prefix" of a given namespace.
- */
-static const char *get_namespace_prefix(namespace_t namespc)
-{
- switch(namespc) {
- case NAMESPACE_NORMAL:
- return "";
- case NAMESPACE_UNION:
- return "union ";
- case NAMESPACE_STRUCT:
- return "struct ";
- case NAMESPACE_ENUM:
- return "enum ";
- case NAMESPACE_LABEL:
- return "label ";
- }
- panic("invalid namespace found");
-}
-
/**
* pushs an environment_entry on the environment stack and links the
* corresponding symbol to the new entry
*/
-static declaration_t *stack_push(stack_entry_t **stack_ptr,
- declaration_t *declaration,
- context_t *parent_context)
+static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
{
symbol_t *symbol = declaration->symbol;
namespace_t namespc = (namespace_t)declaration->namespc;
- /* a declaration should be only pushed once */
- declaration->parent_context = parent_context;
-
- declaration_t *previous_declaration = get_declaration(symbol, namespc);
- assert(declaration != previous_declaration);
- if(previous_declaration != NULL
- && previous_declaration->parent_context == context) {
- if(!is_compatible_declaration(declaration, previous_declaration)) {
- errorf(declaration->source_position, "definition of symbol '%s%Y' with type '%T'", get_namespace_prefix(namespc), symbol, declaration->type);
- errorf(previous_declaration->source_position, "is incompatible with previous declaration of type '%T'", previous_declaration->type);
- } else {
- unsigned old_storage_class = previous_declaration->storage_class;
- unsigned new_storage_class = declaration->storage_class;
- type_t *type = previous_declaration->type;
- type = skip_typeref(type);
-
- if (current_function == NULL) {
- if (old_storage_class != STORAGE_CLASS_STATIC &&
- new_storage_class == STORAGE_CLASS_STATIC) {
- errorf(declaration->source_position, "static declaration of '%Y' follows non-static declaration", symbol);
- errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
- } else {
- if (old_storage_class == STORAGE_CLASS_EXTERN) {
- if (new_storage_class == STORAGE_CLASS_NONE) {
- previous_declaration->storage_class = STORAGE_CLASS_NONE;
- }
- } else if(!is_type_function(type)) {
- warningf(declaration->source_position, "redundant declaration for '%Y'", symbol);
- warningf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
- }
- }
- } else {
- if (old_storage_class == STORAGE_CLASS_EXTERN &&
- new_storage_class == STORAGE_CLASS_EXTERN) {
- warningf(declaration->source_position, "redundant extern declaration for '%Y'\n", symbol);
- warningf(previous_declaration->source_position, "previous declaration of '%Y' was here\n", symbol);
- } else {
- if (old_storage_class == new_storage_class) {
- errorf(declaration->source_position, "redeclaration of '%Y'", symbol);
- } else {
- errorf(declaration->source_position, "redeclaration of '%Y' with different linkage", symbol);
- }
- errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
- }
- }
- }
- return previous_declaration;
- }
-
/* remember old declaration */
stack_entry_t entry;
entry.symbol = symbol;
iter_last->symbol_next = declaration;
}
}
-
- return declaration;
}
-static declaration_t *environment_push(declaration_t *declaration)
+static void environment_push(declaration_t *declaration)
{
assert(declaration->source_position.input_name != NULL);
- return stack_push(&environment_stack, declaration, context);
+ assert(declaration->parent_context != NULL);
+ stack_push(&environment_stack, declaration);
}
-static declaration_t *label_push(declaration_t *declaration)
+static void label_push(declaration_t *declaration)
{
- return stack_push(&label_stack, declaration, ¤t_function->context);
+ declaration->parent_context = ¤t_function->context;
+ stack_push(&label_stack, declaration);
}
/**
return result;
}
-
+static declaration_t *append_declaration(declaration_t *declaration);
static declaration_t *parse_compound_type_specifier(bool is_struct)
{
}
declaration->source_position = token.source_position;
declaration->symbol = symbol;
- record_declaration(declaration);
+ declaration->parent_context = context;
+ if (symbol != NULL) {
+ environment_push(declaration);
+ }
+ append_declaration(declaration);
}
if(token.type == '{') {
if(declaration->init.is_defined) {
assert(symbol != NULL);
- errorf(HERE, "multiple definition of %s %Y",
+ errorf(HERE, "multiple definition of '%s %Y'",
is_struct ? "struct" : "union", symbol);
declaration->context.declarations = NULL;
}
declaration->namespc = NAMESPACE_ENUM;
declaration->source_position = token.source_position;
declaration->symbol = symbol;
+ declaration->parent_context = context;
}
type_t *const type = allocate_type_zero(TYPE_ENUM);
if(declaration->init.is_defined) {
errorf(HERE, "multiple definitions of enum %Y", symbol);
}
- record_declaration(declaration);
+ if (symbol != NULL) {
+ environment_push(declaration);
+ }
+ append_declaration(declaration);
declaration->init.is_defined = 1;
parse_enum_entries(&type->enumt);
return result;
}
-static declaration_t *record_declaration(declaration_t *declaration)
+static declaration_t *append_declaration(declaration_t* const declaration)
{
- assert(declaration->parent_context == NULL);
- assert(context != NULL);
-
- symbol_t *symbol = declaration->symbol;
- if(symbol != NULL) {
- declaration_t *alias = environment_push(declaration);
- if(alias != declaration)
- return alias;
- } else {
- declaration->parent_context = context;
- }
-
- if(last_declaration != NULL) {
+ if (last_declaration != NULL) {
last_declaration->next = declaration;
} else {
context->declarations = declaration;
}
last_declaration = declaration;
-
return declaration;
}
+static declaration_t *internal_record_declaration(
+ declaration_t *const declaration,
+ const bool is_function_definition)
+{
+ const symbol_t *const symbol = declaration->symbol;
+ const namespace_t namespc = (namespace_t)declaration->namespc;
+
+ const type_t *const type = skip_typeref(declaration->type);
+ if (is_type_function(type) && type->function.unspecified_parameters) {
+ warningf(declaration->source_position,
+ "function declaration '%#T' is not a prototype",
+ type, declaration->symbol);
+ }
+
+ declaration_t *const previous_declaration = get_declaration(symbol, namespc);
+ assert(declaration != previous_declaration);
+ if (previous_declaration != NULL
+ && previous_declaration->parent_context == context) {
+ const type_t *const prev_type = skip_typeref(previous_declaration->type);
+ if (!types_compatible(type, prev_type)) {
+ errorf(declaration->source_position,
+ "declaration '%#T' is incompatible with previous declaration '%#T'",
+ type, symbol, previous_declaration->type, symbol);
+ errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
+ } else {
+ unsigned old_storage_class = previous_declaration->storage_class;
+ unsigned new_storage_class = declaration->storage_class;
+
+ /* pretend no storage class means extern for function declarations
+ * (except if the previous declaration is neither none nor extern) */
+ if (is_type_function(type)) {
+ switch (old_storage_class) {
+ case STORAGE_CLASS_NONE:
+ old_storage_class = STORAGE_CLASS_EXTERN;
+
+ case STORAGE_CLASS_EXTERN:
+ if (new_storage_class == STORAGE_CLASS_NONE && !is_function_definition) {
+ new_storage_class = STORAGE_CLASS_EXTERN;
+ }
+ break;
+
+ default: break;
+ }
+ }
+
+ if (old_storage_class == STORAGE_CLASS_EXTERN &&
+ new_storage_class == STORAGE_CLASS_EXTERN) {
+warn_redundant_declaration:
+ warningf(declaration->source_position, "redundant declaration for '%Y'", symbol);
+ warningf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
+ } else if (current_function == NULL) {
+ if (old_storage_class != STORAGE_CLASS_STATIC &&
+ new_storage_class == STORAGE_CLASS_STATIC) {
+ errorf(declaration->source_position, "static declaration of '%Y' follows non-static declaration", symbol);
+ errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
+ } else {
+ if (old_storage_class != STORAGE_CLASS_EXTERN) {
+ goto warn_redundant_declaration;
+ }
+ if (new_storage_class == STORAGE_CLASS_NONE) {
+ previous_declaration->storage_class = STORAGE_CLASS_NONE;
+ }
+ }
+ } else {
+ if (old_storage_class == new_storage_class) {
+ errorf(declaration->source_position, "redeclaration of '%Y'", symbol);
+ } else {
+ errorf(declaration->source_position, "redeclaration of '%Y' with different linkage", symbol);
+ }
+ errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
+ }
+ }
+ return previous_declaration;
+ }
+
+ assert(declaration->parent_context == NULL);
+ assert(declaration->symbol != NULL);
+ assert(context != NULL);
+
+ declaration->parent_context = context;
+
+ environment_push(declaration);
+ return append_declaration(declaration);
+}
+
+static declaration_t *record_declaration(declaration_t *declaration)
+{
+ return internal_record_declaration(declaration, false);
+}
+
+static declaration_t *record_function_definition(declaration_t *const declaration)
+{
+ return internal_record_declaration(declaration, true);
+}
+
static void parser_error_multiple_definition(declaration_t *declaration,
const source_position_t source_position)
{
declaration_t *parameter = declaration->context.declarations;
for( ; parameter != NULL; parameter = parameter->next) {
+ assert(parameter->parent_context == NULL);
+ parameter->parent_context = context;
environment_push(parameter);
}
/* must be a declaration */
if(token.type == ';') {
- parse_anonymous_declaration_rest(&specifiers, record_declaration);
+ parse_anonymous_declaration_rest(&specifiers, append_declaration);
return;
}
ndeclaration->type = type;
}
- declaration_t *declaration = record_declaration(ndeclaration);
+ declaration_t *const declaration = record_function_definition(ndeclaration);
if(ndeclaration != declaration) {
- memcpy(&declaration->context, &ndeclaration->context,
- sizeof(declaration->context));
+ declaration->context = ndeclaration->context;
}
type = skip_typeref(declaration->type);
declaration_t *parameter = declaration->context.declarations;
for( ; parameter != NULL; parameter = parameter->next) {
+ assert(parameter->parent_context == NULL || parameter->parent_context == context);
+ parameter->parent_context = context;
environment_push(parameter);
}
declaration->type = type;
declaration->symbol = symbol;
declaration->source_position = source_position;
-
- /* prepend the implicit definition to the global context
- * this is safe since the symbol wasn't declared as anything else yet
- */
- assert(symbol->declaration == NULL);
-
- context_t *last_context = context;
- context = global_context;
+ declaration->parent_context = global_context;
environment_push(declaration);
declaration->next = context->declarations;
context->declarations = declaration;
- context = last_context;
-
return declaration;
}
}
case EXPR_SELECT: {
const select_expression_t *select = &expression->select;
- type_t *orig_type = select->compound_entry->type;
- type_t *type = skip_typeref(orig_type);
- if(type->kind == TYPE_BITFIELD) {
- return type->bitfield.base;
- } else {
- return orig_type;
- }
+ return select->compound_entry->type;
}
case EXPR_UNARY_DEREFERENCE: {
expression_t *value = expression->unary.value;
}
type_t *type = declaration->type;
- type_t *skipped_type = skip_typeref(type);
- if(skipped_type->kind == TYPE_BITFIELD) {
- type = skipped_type->bitfield.base;
- }
/* we always do the auto-type conversions; the & and sizeof parser contains
* code to revert this! */
/* we always do the auto-type conversions; the & and sizeof parser contains
* code to revert this! */
type_t *expression_type = automatic_type_conversion(iter->type);
- if(expression_type->kind == TYPE_BITFIELD) {
- expression_type = expression_type->bitfield.base;
- }
select->select.compound_entry = iter;
select->base.datatype = expression_type;
+ if(expression_type->kind == TYPE_BITFIELD) {
+ expression_t *extract
+ = allocate_expression_zero(EXPR_UNARY_BITFIELD_EXTRACT);
+ extract->unary.value = select;
+ extract->base.datatype = expression_type->bitfield.base;
+
+ return extract;
+ }
+
return select;
}
expression->expression.datatype = result_type;
}
+/**
+ * Check the semantic of the address taken expression.
+ */
static void semantic_take_addr(unary_expression_t *expression)
{
expression_t *value = expression->value;
reference_expression_t *reference = (reference_expression_t*) value;
declaration_t *declaration = reference->declaration;
if(declaration != NULL) {
+ if (declaration->storage_class == STORAGE_CLASS_REGISTER) {
+ errorf(expression->expression.source_position,
+ "address of register variable '%Y' requested",
+ declaration->symbol);
+ }
declaration->address_taken = 1;
}
}
static expression_t *parse_##unexpression_type(unsigned precedence) \
{ \
eat(token_type); \
- \
+ \
expression_t *unary_expression \
= allocate_expression_zero(unexpression_type); \
+ unary_expression->base.source_position = HERE; \
unary_expression->unary.value = parse_sub_expression(precedence); \
\
sfunc(&unary_expression->unary); \
- \
+ \
return unary_expression; \
}
return;
}
if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
- errorf(HERE, "assignment to readonly location '%E' (type '%T')", left, orig_type_left);
+ errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
+ orig_type_left);
return;
}
if(is_type_incomplete(type_left)) {
- errorf(HERE, "left-hand side of assignment '%E' has incomplete type '%T'", left, orig_type_left);
+ errorf(HERE,
+ "left-hand side of assignment '%E' has incomplete type '%T'",
+ left, orig_type_left);
return;
}
if(is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
- errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields", left, orig_type_left);
+ errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
+ left, orig_type_left);
return;
}
/* if source position is already set then the label is defined twice,
* otherwise it was just mentioned in a goto so far */
if(label->source_position.input_name != NULL) {
- errorf(HERE, "duplicate label '%Y'\n", symbol);
- errorf(label->source_position, "previous definition of '%Y' was here\n",
+ errorf(HERE, "duplicate label '%Y'", symbol);
+ errorf(label->source_position, "previous definition of '%Y' was here",
symbol);
} else {
label->source_position = token.source_position;
label_statement->statement.source_position = token.source_position;
label_statement->label = label;
- expect(':');
+ eat(':');
if(token.type == '}') {
/* TODO only warn? */
statement->statement.source_position = token.source_position;
expect('(');
- statement->expression = parse_expression();
+ expression_t *const expr = parse_expression();
+ type_t *const type = promote_integer(expr->base.datatype);
+ statement->expression = create_implicit_cast(expr, type);
expect(')');
statement->body = parse_statement();
return statement;
}
+/**
+ * Check if a given declaration represents a local variable.
+ */
+static bool is_local_var_declaration(const declaration_t *declaration) {
+ switch ((storage_class_tag_t) declaration->storage_class) {
+ case STORAGE_CLASS_NONE:
+ case STORAGE_CLASS_AUTO:
+ case STORAGE_CLASS_REGISTER: {
+ const type_t *type = skip_typeref(declaration->type);
+ if(is_type_function(type)) {
+ return false;
+ } else {
+ return true;
+ }
+ }
+ default:
+ return false;
+ }
+}
+
+/**
+ * Check if a given expression represents a local variable.
+ */
+static bool is_local_variable(const expression_t *expression)
+{
+ if (expression->base.kind != EXPR_REFERENCE) {
+ return false;
+ }
+ const declaration_t *declaration = expression->reference.declaration;
+ return is_local_var_declaration(declaration);
+}
+
/**
* Parse a return statement.
*/
if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
&& !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
- warningf(HERE, "'return' with a value, in function returning void");
+ warningf(statement->statement.source_position,
+ "'return' with a value, in function returning void");
return_value = NULL;
} else {
if(return_type != NULL) {
semantic_assign(return_type, &return_value, "'return'");
}
}
+ /* check for returning address of a local var */
+ if (return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
+ const expression_t *expression = return_value->unary.value;
+ if (is_local_variable(expression)) {
+ warningf(statement->statement.source_position,
+ "function returns address of local variable");
+ }
+ }
} else {
if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
- warningf(HERE, "'return' without value, in function returning non-void");
+ warningf(statement->statement.source_position,
+ "'return' without value, in function returning non-void");
}
}
statement->return_value = return_value;