diff options
| -rw-r--r-- | lib/Sema/SemaDecl.cpp | 9 | ||||
| -rw-r--r-- | test/Sema/cast-to-union.c | 10 |
2 files changed, 18 insertions, 1 deletions
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 468e95523c..07966399da 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -2228,7 +2228,14 @@ bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { // Allow block exprs at top level. if (Init->getType()->isBlockPointerType()) return false; - + + // GCC cast to union extension + // note: the validity of the cast expr is checked by CheckCastTypes() + if (CastExpr *C = dyn_cast<CastExpr>(Init)) { + QualType T = C->getType(); + return T->isUnionType() && CheckForConstantInitializer(C->getSubExpr(), T); + } + InitializerElementNotConstant(Init); return true; } diff --git a/test/Sema/cast-to-union.c b/test/Sema/cast-to-union.c index f23a34b11c..495b27cb1b 100644 --- a/test/Sema/cast-to-union.c +++ b/test/Sema/cast-to-union.c @@ -7,3 +7,13 @@ void test(int x) { f((union u)x); // expected-warning {{C99 forbids casts to union type}} f((union u)&x); // expected-error {{cast to union type from type 'int *' not present in union}} } + +union u w = (union u)2; // expected-warning {{C99 forbids casts to union type}} +union u ww = (union u)1.0; // expected-error{{cast to union type from type 'double' not present in union}} +union u x = 7; // expected-error{{incompatible type initializing 'int', expected 'union u'}} +int i; +union u zz = (union u)i; // expected-error{{initializer element is not a compile-time constant}} expected-warning {{C99 forbids casts to union type}} + +struct s {int a, b;}; +struct s y = { 1, 5 }; +struct s z = (struct s){ 1, 5 }; |