// C++ anonymous unions and GNU anonymous structs/unions
def ext_anonymous_union : Extension<
- "anonymous unions are a GNU extension in C">, InGroup<GNU>;
-def ext_anonymous_struct : Extension<
+ "anonymous unions are a C11 extension">, InGroup<C11>;
+def ext_gnu_anonymous_struct : Extension<
"anonymous structs are a GNU extension">, InGroup<GNU>;
+def ext_c11_anonymous_struct : Extension<
+ "anonymous structs are a C11 extension">, InGroup<C11>;
def err_anonymous_union_not_static : Error<
"anonymous unions at namespace or global scope must be declared 'static'">;
def err_anonymous_union_with_storage_spec : Error<
/// BuildAnonymousStructOrUnion - Handle the declaration of an
/// anonymous structure or union. Anonymous unions are a C++ feature
-/// (C++ [class.union]) and a GNU C extension; anonymous structures
-/// are a GNU C and GNU C++ extension.
+/// (C++ [class.union]) and a C11 feature; anonymous structures
+/// are a C11 feature and GNU C++ extension.
Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
AccessSpecifier AS,
RecordDecl *Record) {
DeclContext *Owner = Record->getDeclContext();
// Diagnose whether this anonymous struct/union is an extension.
- if (Record->isUnion() && !getLangOptions().CPlusPlus)
+ if (Record->isUnion() && !getLangOptions().CPlusPlus && !getLangOptions().C11)
Diag(Record->getLocation(), diag::ext_anonymous_union);
- else if (!Record->isUnion())
- Diag(Record->getLocation(), diag::ext_anonymous_struct);
+ else if (!Record->isUnion() && getLangOptions().CPlusPlus)
+ Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
+ else if (!Record->isUnion() && !getLangOptions().C11)
+ Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);
// C and C++ require different kinds of checks for anonymous
// structs/unions.
--- /dev/null
+// Check for warnings in non-C11 mode:
+// RUN: %clang_cc1 -fsyntax-only -verify -Wc11-extensions %s
+
+// Expect no warnings in C11 mode:
+// RUN: %clang_cc1 -fsyntax-only -pedantic -Werror -std=c11 %s
+
+struct s {
+ int a;
+ struct { // expected-warning{{anonymous structs are a C11 extension}}
+ int b;
+ };
+};
+
+struct t {
+ int a;
+ union { // expected-warning{{anonymous unions are a C11 extension}}
+ int b;
+ };
+};
const struct {} ipcp = { sppp_ipv6cp_up }; //expected-warning{{empty struct is a GNU extension}} \
// expected-warning{{excess elements in struct initializer}}
-struct _Matrix { union { float m[4][4]; }; }; //expected-warning{{anonymous unions are a GNU extension in C}}
+struct _Matrix { union { float m[4][4]; }; }; //expected-warning{{anonymous unions are a C11 extension}}
typedef struct _Matrix Matrix;
void test_matrix() {
const Matrix mat1 = {