Improve GCC compatibility by allowing static tentative definitions of
incomplete type (with a warning), from Enea Zaffanella!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76451 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 28ac9d1..d1d06e3 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2899,29 +2899,32 @@
diag::err_typecheck_decl_incomplete_type))
IDecl->setInvalidDecl();
}
- // File scope. C99 6.9.2p2: A declaration of an identifier for and
+ // File scope. C99 6.9.2p2: A declaration of an identifier for an
// object that has file scope without an initializer, and without a
// storage-class specifier or with the storage-class specifier "static",
// constitutes a tentative definition. Note: A tentative definition with
// external linkage is valid (C99 6.2.2p5).
- if (IDecl->isTentativeDefinition(Context)) {
- QualType CheckType = T;
- unsigned DiagID = diag::err_typecheck_decl_incomplete_type;
-
- const IncompleteArrayType *ArrayT = Context.getAsIncompleteArrayType(T);
- if (ArrayT) {
- CheckType = ArrayT->getElementType();
- DiagID = diag::err_illegal_decl_array_incomplete_type;
+ if (IDecl->isTentativeDefinition(Context) && !IDecl->isInvalidDecl()) {
+ if (const IncompleteArrayType *ArrayT
+ = Context.getAsIncompleteArrayType(T)) {
+ if (RequireCompleteType(IDecl->getLocation(),
+ ArrayT->getElementType(),
+ diag::err_illegal_decl_array_incomplete_type))
+ IDecl->setInvalidDecl();
}
-
- if (IDecl->isInvalidDecl()) {
- // Do nothing with invalid declarations
- } else if ((ArrayT || IDecl->getStorageClass() == VarDecl::Static) &&
- RequireCompleteType(IDecl->getLocation(), CheckType, DiagID)) {
+ else if (IDecl->getStorageClass() == VarDecl::Static) {
// C99 6.9.2p3: If the declaration of an identifier for an object is
- // a tentative definition and has internal linkage (C99 6.2.2p3), the
+ // a tentative definition and has internal linkage (C99 6.2.2p3), the
// declared type shall not be an incomplete type.
- IDecl->setInvalidDecl();
+ // NOTE: code such as the following
+ // static struct s;
+ // struct s { int a; };
+ // is accepted by gcc. Hence here we issue a warning instead of
+ // an error and we do not invalidate the static declaration.
+ // NOTE: to avoid multiple warnings, only check the first declaration.
+ if (IDecl->getPreviousDeclaration() == 0)
+ RequireCompleteType(IDecl->getLocation(), T,
+ diag::ext_typecheck_decl_incomplete_type);
}
}
}