PR35456: Track definedness of variable template specializations separately from

whether they have an initializer.

We cannot distinguish between a declaration of a variable template
specialization and a definition of one that lacks an initializer without this,
and would previously mistake the latter for the former.

llvm-svn: 319605

2 files changed, 8 insertions, 5 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 41c4fd0e6c0..29846b61010 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2029,9 +2029,12 @@ VarDecl::isThisDeclarationADefinition(ASTContext &C) const {
   // A variable template specialization (other than a static data member
   // template or an explicit specialization) is a declaration until we
   // instantiate its initializer.
-  if (isa<VarTemplateSpecializationDecl>(this) &&
-      getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
-    return DeclarationOnly;
+  if (auto *VTSD = dyn_cast<VarTemplateSpecializationDecl>(this)) {
+    if (VTSD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization &&
+        !isa<VarTemplatePartialSpecializationDecl>(VTSD) &&
+        !VTSD->IsCompleteDefinition)
+      return DeclarationOnly;
+  }
 
   if (hasExternalStorage())
     return DeclarationOnly;
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index f5a2ab07bf7..54e8dd86624 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -1043,13 +1043,13 @@ VarTemplateSpecializationDecl::VarTemplateSpecializationDecl(
               SpecializedTemplate->getIdentifier(), T, TInfo, S),
       SpecializedTemplate(SpecializedTemplate),
       TemplateArgs(TemplateArgumentList::CreateCopy(Context, Args)),
-      SpecializationKind(TSK_Undeclared) {}
+      SpecializationKind(TSK_Undeclared), IsCompleteDefinition(false) {}
 
 VarTemplateSpecializationDecl::VarTemplateSpecializationDecl(Kind DK,
                                                              ASTContext &C)
     : VarDecl(DK, C, nullptr, SourceLocation(), SourceLocation(), nullptr,
               QualType(), nullptr, SC_None),
-      SpecializationKind(TSK_Undeclared) {}
+      SpecializationKind(TSK_Undeclared), IsCompleteDefinition(false) {}
 
 VarTemplateSpecializationDecl *VarTemplateSpecializationDecl::Create(
     ASTContext &Context, DeclContext *DC, SourceLocation StartLoc,