[C++20] [Modules] Make the linkage consistent for class template and its

specialization

Previously in D120397, we've handled the linkage for function template
and its specialization. But we forgot to handle it for class templates
and their specialization. So we make it in the patch with the similar
approach.

1 files changed, 20 insertions, 1 deletions

diff --git a/clang/unittests/AST/DeclTest.cpp b/clang/unittests/AST/DeclTest.cpp
index 560c6b3..71835a0 100644
--- a/clang/unittests/AST/DeclTest.cpp
+++ b/clang/unittests/AST/DeclTest.cpp
@@ -179,7 +179,14 @@ TEST(Decl, InConsistLinkageForTemplates) {
     void f() {}
 
     template <>
-    void f<int>() {})");
+    void f<int>() {}
+
+    export template <class T>
+    class C {};
+
+    template<>
+    class C<int> {};
+    )");
 
   auto AST =
       tooling::buildASTFromCodeWithArgs(Code.code(), /*Args=*/{"-std=c++20"});
@@ -193,6 +200,18 @@ TEST(Decl, InConsistLinkageForTemplates) {
   const FunctionDecl *SpecializedF = Funcs[1].getNodeAs<FunctionDecl>("f");
   EXPECT_EQ(TemplateF->getLinkageInternal(),
             SpecializedF->getLinkageInternal());
+
+  llvm::SmallVector<ast_matchers::BoundNodes, 1> ClassTemplates =
+      match(classTemplateDecl().bind("C"), Ctx);
+  llvm::SmallVector<ast_matchers::BoundNodes, 1> ClassSpecializations =
+      match(classTemplateSpecializationDecl().bind("C"), Ctx);
+
+  EXPECT_EQ(ClassTemplates.size(), 1U);
+  EXPECT_EQ(ClassSpecializations.size(), 1U);
+  const NamedDecl *TemplatedC = ClassTemplates[0].getNodeAs<NamedDecl>("C");
+  const NamedDecl *SpecializedC = ClassSpecializations[0].getNodeAs<NamedDecl>("C");
+  EXPECT_EQ(TemplatedC->getLinkageInternal(),
+            SpecializedC->getLinkageInternal());
 }
 
 TEST(Decl, ModuleAndInternalLinkage) {