Implement the GNU semantics for forward declarations of enum types in
C and C++. Fixes PR3688.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66282 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 953e39f..f4c2788 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2976,8 +2976,8 @@
}
}
} else if (TK == TK_Reference && SS.isEmpty() && Name &&
- (Kind != TagDecl::TK_enum)) {
- // C++ [basic.scope.pdecl]p5:
+ (Kind != TagDecl::TK_enum || !getLangOptions().CPlusPlus)) {
+ // C.scope.pdecl]p5:
// -- for an elaborated-type-specifier of the form
//
// class-key identifier
@@ -2993,7 +2993,10 @@
//
// C99 6.7.2.3p8 has a similar (but not identical!) provision for
// C structs and unions.
-
+ //
+ // GNU C also supports this behavior as part of its incomplete
+ // enum types extension, while GNU C++ does not.
+ //
// Find the context where we'll be declaring the tag.
// FIXME: We would like to maintain the current DeclContext as the
// lexical context,
@@ -3027,7 +3030,11 @@
New = EnumDecl::Create(Context, SearchDC, Loc, Name,
cast_or_null<EnumDecl>(PrevDecl));
// If this is an undefined enum, warn.
- if (TK != TK_Definition) Diag(Loc, diag::ext_forward_ref_enum);
+ if (TK != TK_Definition && !Invalid) {
+ unsigned DK = getLangOptions().CPlusPlus? diag::err_forward_ref_enum
+ : diag::ext_forward_ref_enum;
+ Diag(Loc, DK);
+ }
} else {
// struct/union/class