Diagnose the declaration of explicit specializations after an implicit

instantiation has already been required. To do so, keep track of the
point of instantiation for anything that can be instantiated.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83890 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 8 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index f12f2b9985..d29b84b308 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -4279,14 +4279,22 @@ Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
           // Diagnose attempts to redefine a tag.
           if (TUK == TUK_Definition) {
             if (TagDecl *Def = PrevTagDecl->getDefinition(Context)) {
-              Diag(NameLoc, diag::err_redefinition) << Name;
-              Diag(Def->getLocation(), diag::note_previous_definition);
-              // If this is a redefinition, recover by making this
-              // struct be anonymous, which will make any later
-              // references get the previous definition.
-              Name = 0;
-              PrevDecl = 0;
-              Invalid = true;
+              // If we're defining a specialization and the previous definition
+              // is from an implicit instantiation, don't emit an error
+              // here; we'll catch this in the general case below.
+              if (!isExplicitSpecialization ||
+                  !isa<CXXRecordDecl>(Def) ||
+                  cast<CXXRecordDecl>(Def)->getTemplateSpecializationKind() 
+                                               == TSK_ExplicitSpecialization) {
+                Diag(NameLoc, diag::err_redefinition) << Name;
+                Diag(Def->getLocation(), diag::note_previous_definition);
+                // If this is a redefinition, recover by making this
+                // struct be anonymous, which will make any later
+                // references get the previous definition.
+                Name = 0;
+                PrevDecl = 0;
+                Invalid = true;
+              }
             } else {
               // If the type is currently being defined, complain
               // about a nested redefinition.