[ASTImporter] Corrected lookup at import of templated record decl

Summary:
When a CXXRecordDecl under ClassTemplateDecl is imported, check
the templated record decl for similarity instead of the template.

Reviewers: a.sidorin

Reviewed By: a.sidorin

Subscribers: martong, cfe-commits

Differential Revision: https://reviews.llvm.org/D47313

Patch by Balazs Keri!

llvm-svn: 333522

1 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index d64b64ce43b..f812244ed3c 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -2015,7 +2015,14 @@ Decl *ASTNodeImporter::VisitRecordDecl(RecordDecl *D) {
         if (const auto *Tag = Typedef->getUnderlyingType()->getAs<TagType>())
           Found = Tag->getDecl();
       }
-      
+
+      if (D->getDescribedTemplate()) {
+        if (auto *Template = dyn_cast<ClassTemplateDecl>(Found))
+          Found = Template->getTemplatedDecl();
+        else
+          continue;
+      }
+
       if (auto *FoundRecord = dyn_cast<RecordDecl>(Found)) {
         if (!SearchName) {
           // If both unnamed structs/unions are in a record context, make sure