From 59f1bf46f8c258b9c784ff921b89fb6cb7a06612 Mon Sep 17 00:00:00 2001
From: Vince Bridgers <vince.a.bridgers@gmail.com>
Date: Wed, 1 Jul 2020 16:49:08 -0500
Subject: [PATCH] [ASTImporter] Add unittest case for friend decl import

Summary:
This change adds a matching test case for the recent bug fix to
VisitFriendDecl in ASTImporterLookup.cpp.

See https://reviews.llvm.org/D82882 for details.

Reviewers: martong, a.sidorin, shafik

Reviewed By: martong

Subscribers: rnkovacs, teemperor, cfe-commits, dkrupp

Tags: #clang

Differential Revision: https://reviews.llvm.org/D83006
---
 clang/unittests/AST/ASTImporterTest.cpp | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 172fbb461a7e..d6a5afeeb489 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -3416,6 +3416,26 @@ TEST_P(ASTImporterOptionSpecificTestBase,
   EXPECT_TRUE(ToCtor->hasBody());
 }
 
+TEST_P(ASTImporterOptionSpecificTestBase, ClassTemplateFriendDecl) {
+  const auto *Code =
+      R"(
+      template <class T> class X {  friend T; };
+      struct Y {};
+      template class X<Y>;
+    )";
+  Decl *ToTU = getToTuDecl(Code, Lang_CXX11);
+  Decl *FromTU = getTuDecl(Code, Lang_CXX11);
+  auto *FromSpec = FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
+      FromTU, classTemplateSpecializationDecl());
+  auto *ToSpec = FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
+      ToTU, classTemplateSpecializationDecl());
+
+  auto *ImportedSpec = Import(FromSpec, Lang_CXX11);
+  EXPECT_EQ(ImportedSpec, ToSpec);
+  EXPECT_EQ(1u, DeclCounter<ClassTemplateSpecializationDecl>().match(
+                    ToTU, classTemplateSpecializationDecl()));
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase,
        ClassTemplatePartialSpecializationsShouldNotBeDuplicated) {
   auto Code =