[ASTImporter] Add test RedeclChainShouldBeCorrectAmongstNamespaces

Summary:
We add a new test to show that redecl chains are not handled properly
amongst namespaces. We cannot pass this test now, so this is disabled.
Subsequent patches will make this test pass.

Reviewers: a_sidorin, shafik, a.sidorin

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D57901

llvm-svn: 353684

1 files changed, 41 insertions, 0 deletions

diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 0aadf5693ad..7953cbe58c4 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -5143,6 +5143,47 @@ INSTANTIATE_TEST_CASE_P(
     ParameterizedTests, CanonicalRedeclChain,
     ::testing::Values(ArgVector()),);
 
+// FIXME This test is disabled currently, upcoming patches will make it
+// possible to enable.
+TEST_P(ASTImporterOptionSpecificTestBase,
+       DISABLED_RedeclChainShouldBeCorrectAmongstNamespaces) {
+  Decl *FromTU = getTuDecl(
+      R"(
+      namespace NS {
+        struct X;
+        struct Y {
+          static const int I = 3;
+        };
+      }
+      namespace NS {
+        struct X {  // <--- To be imported
+          void method(int i = Y::I) {}
+          int f;
+        };
+      }
+      )",
+      Lang_CXX);
+  auto *FromFwd = FirstDeclMatcher<CXXRecordDecl>().match(
+      FromTU, cxxRecordDecl(hasName("X"), unless(isImplicit())));
+  auto *FromDef = LastDeclMatcher<CXXRecordDecl>().match(
+      FromTU,
+      cxxRecordDecl(hasName("X"), isDefinition(), unless(isImplicit())));
+  ASSERT_NE(FromFwd, FromDef);
+  ASSERT_FALSE(FromFwd->isThisDeclarationADefinition());
+  ASSERT_TRUE(FromDef->isThisDeclarationADefinition());
+  ASSERT_EQ(FromFwd->getCanonicalDecl(), FromDef->getCanonicalDecl());
+
+  auto *ToDef = cast_or_null<CXXRecordDecl>(Import(FromDef, Lang_CXX));
+  auto *ToFwd = cast_or_null<CXXRecordDecl>(Import(FromFwd, Lang_CXX));
+  EXPECT_NE(ToFwd, ToDef);
+  EXPECT_FALSE(ToFwd->isThisDeclarationADefinition());
+  EXPECT_TRUE(ToDef->isThisDeclarationADefinition());
+  EXPECT_EQ(ToFwd->getCanonicalDecl(), ToDef->getCanonicalDecl());
+  auto *ToTU = ToAST->getASTContext().getTranslationUnitDecl();
+  // We expect no (ODR) warning during the import.
+  EXPECT_EQ(0u, ToTU->getASTContext().getDiagnostics().getNumWarnings());
+}
+
 INSTANTIATE_TEST_CASE_P(ParameterizedTests, ASTImporterLookupTableTest,
                         DefaultTestValuesForRunOptions, );