Bring ASTReader and Writer into sync for the case where a canonical template specialization was written, which is non-canonical at the time of reading: force the reading of the ClassTemplateDecl if it was written.

The easiest way out is to store whether the decl was canonical at the time of writing.
Add test.

llvm-svn: 164927

2 files changed, 11 insertions, 7 deletions

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index c9788a32164..843893d90f2 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1395,14 +1395,17 @@ void ASTDeclReader::VisitClassTemplateSpecializationDecl(
                                                      TemplArgs.size());
   D->PointOfInstantiation = ReadSourceLocation(Record, Idx);
   D->SpecializationKind = (TemplateSpecializationKind)Record[Idx++];
-  
-  if (D->isCanonicalDecl()) { // It's kept in the folding set.
+
+  bool writtenAsCanonicalDecl = Record[Idx++];
+  if (writtenAsCanonicalDecl) {
     ClassTemplateDecl *CanonPattern = ReadDeclAs<ClassTemplateDecl>(Record,Idx);
-    if (ClassTemplatePartialSpecializationDecl *Partial
-                       = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
-      CanonPattern->getCommonPtr()->PartialSpecializations.InsertNode(Partial);
-    } else {
-      CanonPattern->getCommonPtr()->Specializations.InsertNode(D);
+    if (D->isCanonicalDecl()) { // It's kept in the folding set.
+      if (ClassTemplatePartialSpecializationDecl *Partial
+                        = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
+       CanonPattern->getCommonPtr()->PartialSpecializations.InsertNode(Partial);
+      } else {
+        CanonPattern->getCommonPtr()->Specializations.InsertNode(D);
+      }
     }
   }
 }
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 7122bca9699..0f9bb3824b8 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -1106,6 +1106,7 @@ void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
   Writer.AddTemplateArgumentList(&D->getTemplateArgs(), Record);
   Writer.AddSourceLocation(D->getPointOfInstantiation(), Record);
   Record.push_back(D->getSpecializationKind());
+  Record.push_back(D->isCanonicalDecl());
 
   if (D->isCanonicalDecl()) {
     // When reading, we'll add it to the folding set of the following template.