From: Gabor Marton <martongabesz@gmail.com>
Date: Wed, 30 May 2018 09:19:26 +0000 (+0000)
Subject: [ASTImporter] Corrected lookup at import of templated record decl
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=86f879c238229ae1d58ce3e605b8eee2e513d660;p=clang

[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!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@333522 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index d64b64ce43..f812244ed3 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/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
diff --git a/unittests/AST/ASTImporterTest.cpp b/unittests/AST/ASTImporterTest.cpp
index 76ea259433..5e2dcf73fc 100644
--- a/unittests/AST/ASTImporterTest.cpp
+++ b/unittests/AST/ASTImporterTest.cpp
@@ -1107,6 +1107,50 @@ TEST(ImportExpr, DependentSizedArrayType) {
                  has(fieldDecl(hasType(dependentSizedArrayType())))))));
 }
 
+TEST_P(ASTImporterTestBase, ImportOfTemplatedDeclOfClassTemplateDecl) {
+  Decl *FromTU = getTuDecl("template<class X> struct S{};", Lang_CXX);
+  auto From =
+      FirstDeclMatcher<ClassTemplateDecl>().match(FromTU, classTemplateDecl());
+  ASSERT_TRUE(From);
+  auto To = cast<ClassTemplateDecl>(Import(From, Lang_CXX));
+  ASSERT_TRUE(To);
+  Decl *ToTemplated = To->getTemplatedDecl();
+  Decl *ToTemplated1 = Import(From->getTemplatedDecl(), Lang_CXX);
+  EXPECT_TRUE(ToTemplated1);
+  EXPECT_EQ(ToTemplated1, ToTemplated);
+}
+
+TEST_P(ASTImporterTestBase, ImportCorrectTemplatedDecl) {
+  auto Code =
+        R"(
+        namespace x {
+          template<class X> struct S1{};
+          template<class X> struct S2{};
+          template<class X> struct S3{};
+        }
+        )";
+  Decl *FromTU = getTuDecl(Code, Lang_CXX);
+  auto FromNs =
+      FirstDeclMatcher<NamespaceDecl>().match(FromTU, namespaceDecl());
+  auto ToNs = cast<NamespaceDecl>(Import(FromNs, Lang_CXX));
+  ASSERT_TRUE(ToNs);
+  auto From =
+      FirstDeclMatcher<ClassTemplateDecl>().match(FromTU,
+                                                  classTemplateDecl(
+                                                      hasName("S2")));
+  auto To =
+      FirstDeclMatcher<ClassTemplateDecl>().match(ToNs,
+                                                  classTemplateDecl(
+                                                      hasName("S2")));
+  ASSERT_TRUE(From);
+  ASSERT_TRUE(To);
+  auto ToTemplated = To->getTemplatedDecl();
+  auto ToTemplated1 =
+      cast<CXXRecordDecl>(Import(From->getTemplatedDecl(), Lang_CXX));
+  EXPECT_TRUE(ToTemplated1);
+  ASSERT_EQ(ToTemplated1, ToTemplated);
+}
+
 TEST_P(ASTImporterTestBase, DISABLED_ImportFunctionWithBackReferringParameter) {
   Decl *From, *To;
   std::tie(From, To) = getImportedDecl(