Permit redeclaration of tags introduced by using decls
This valid construct appears in MSVC headers where it's used to provide a
definition for the '::type_info' compiler builtin type.
llvm-svn: 199490
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e14fc53..62fedbf 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -10681,7 +10681,8 @@
}
if (!Previous.empty()) {
- NamedDecl *PrevDecl = (*Previous.begin())->getUnderlyingDecl();
+ NamedDecl *DirectPrevDecl = *Previous.begin();
+ NamedDecl *PrevDecl = DirectPrevDecl->getUnderlyingDecl();
// It's okay to have a tag decl in the same scope as a typedef
// which hides a tag decl in the same scope. Finding this
@@ -10713,7 +10714,7 @@
// in the same scope (so that the definition/declaration completes or
// rementions the tag), reuse the decl.
if (TUK == TUK_Reference || TUK == TUK_Friend ||
- isDeclInScope(PrevDecl, SearchDC, S,
+ isDeclInScope(DirectPrevDecl, SearchDC, S,
SS.isNotEmpty() || isExplicitSpecialization)) {
// Make sure that this wasn't declared as an enum and now used as a
// struct or something similar.
diff --git a/clang/test/SemaCXX/using-decl-1.cpp b/clang/test/SemaCXX/using-decl-1.cpp
index 24d92f1..ed5cce7 100644
--- a/clang/test/SemaCXX/using-decl-1.cpp
+++ b/clang/test/SemaCXX/using-decl-1.cpp
@@ -119,6 +119,27 @@
};
}
+namespace using_tag_redeclaration
+{
+ struct S;
+ namespace N {
+ using ::using_tag_redeclaration::S;
+ struct S {}; // expected-note {{previous definition is here}}
+ }
+ void f() {
+ N::S s1;
+ S s2;
+ }
+ void g() {
+ struct S; // expected-note {{forward declaration of 'S'}}
+ S s3; // expected-error {{variable has incomplete type 'S'}}
+ }
+ void h() {
+ using ::using_tag_redeclaration::S;
+ struct S {}; // expected-error {{redefinition of 'S'}}
+ }
+}
+
// Don't suggest non-typenames for positions requiring typenames.
namespace using_suggestion_tyname_val {
namespace N { void FFF() {} }