[ASTImporter] Fix redecl failures of ClassTemplateSpec

Summary:
Redecl chains of class template specializations are not handled well
currently. We want to handle them similarly to functions, i.e. try to
keep the structure of the original AST as much as possible. The aim is
to not squash a prototype with a definition, rather we create both and
put them in a redecl chain.

Reviewers: a_sidorin, shafik, a.sidorin

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

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58673

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@356452 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 42 insertions, 6 deletions

diff --git a/unittests/AST/ASTImporterTest.cpp b/unittests/AST/ASTImporterTest.cpp
index ca59bc0c47..497d22007e 100644
--- a/unittests/AST/ASTImporterTest.cpp
+++ b/unittests/AST/ASTImporterTest.cpp
@@ -3575,12 +3575,10 @@ TEST_P(ASTImporterOptionSpecificTestBase,
   // The second specialization is different from the first, thus it violates
   // ODR, consequently we expect to keep the first specialization only, which is
   // already in the "To" context.
-  EXPECT_TRUE(ImportedSpec);
-  auto *ToSpec = FirstDeclMatcher<ClassTemplateSpecializationDecl>().match(
-      ToTU, classTemplateSpecializationDecl(hasName("X")));
-  EXPECT_EQ(ImportedSpec, ToSpec);
-  EXPECT_EQ(1u, DeclCounter<ClassTemplateSpecializationDecl>().match(
-                    ToTU, classTemplateSpecializationDecl()));
+  EXPECT_FALSE(ImportedSpec);
+  EXPECT_EQ(1u,
+            DeclCounter<ClassTemplateSpecializationDecl>().match(
+                ToTU, classTemplateSpecializationDecl(hasName("X"))));
 }
 
 TEST_P(ASTImporterOptionSpecificTestBase,
@@ -3955,6 +3953,23 @@ struct FunctionTemplateSpec {
   }
 };
 
+struct ClassTemplateSpec {
+  using DeclTy = ClassTemplateSpecializationDecl;
+  static constexpr auto *Prototype =
+    R"(
+    template <class T> class X;
+    template <> class X<int>;
+    )";
+  static constexpr auto *Definition =
+    R"(
+    template <class T> class X;
+    template <> class X<int> {};
+    )";
+  BindableMatcher<Decl> getPattern() {
+    return classTemplateSpecializationDecl(hasName("X"), unless(isImplicit()));
+  }
+};
+
 template <typename TypeParam>
 struct RedeclChain : ASTImporterOptionSpecificTestBase {
 
@@ -4276,6 +4291,9 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
     RedeclChain, FunctionTemplateSpec, ,
     PrototypeShouldBeImportedAsAPrototypeWhenThereIsNoDefinition)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
+    RedeclChain, ClassTemplateSpec, ,
+    PrototypeShouldBeImportedAsAPrototypeWhenThereIsNoDefinition)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
     RedeclChain, Function, , DefinitionShouldBeImportedAsADefinition)
@@ -4291,6 +4309,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
     RedeclChain, FunctionTemplateSpec, ,
     DefinitionShouldBeImportedAsADefinition)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(
+    RedeclChain, ClassTemplateSpec, , DefinitionShouldBeImportedAsADefinition)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportPrototypeAfterImportedPrototype)
@@ -4304,6 +4324,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
                                         ImportPrototypeAfterImportedPrototype)
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec, ,
                                         ImportPrototypeAfterImportedPrototype)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportPrototypeAfterImportedPrototype)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportDefinitionAfterImportedPrototype)
@@ -4317,6 +4339,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
                                         ImportDefinitionAfterImportedPrototype)
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec, ,
                                         ImportDefinitionAfterImportedPrototype)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportDefinitionAfterImportedPrototype)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportPrototypeAfterImportedDefinition)
@@ -4330,6 +4354,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
                                         ImportPrototypeAfterImportedDefinition)
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec, ,
                                         ImportPrototypeAfterImportedDefinition)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportPrototypeAfterImportedDefinition)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportPrototypes)
@@ -4343,6 +4369,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
 // FIXME This does not pass, possible error with Spec import.
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec,
                                         DISABLED_, ImportPrototypes)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportPrototypes)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportDefinitions)
@@ -4357,6 +4385,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
 // FIXME This does not pass, possible error with Spec import.
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec,
                                         DISABLED_, ImportDefinitions)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportDefinitions)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportDefinitionThenPrototype)
@@ -4372,6 +4402,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec,
                                         DISABLED_,
                                         ImportDefinitionThenPrototype)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportDefinitionThenPrototype)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         ImportPrototypeThenDefinition)
@@ -4387,6 +4419,8 @@ ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplate, ,
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, FunctionTemplateSpec,
                                         DISABLED_,
                                         ImportPrototypeThenDefinition)
+ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, ClassTemplateSpec, ,
+                                        ImportPrototypeThenDefinition)
 
 ASTIMPORTER_INSTANTIATE_TYPED_TEST_CASE(RedeclChain, Function, ,
                                         WholeRedeclChainIsImportedAtOnce)
@@ -4420,6 +4454,8 @@ INSTANTIATE_TEST_CASE_P(ParameterizedTests, RedeclChainClassTemplate,
                         DefaultTestValuesForRunOptions, );
 INSTANTIATE_TEST_CASE_P(ParameterizedTests, RedeclChainFunctionTemplateSpec,
                         DefaultTestValuesForRunOptions, );
+INSTANTIATE_TEST_CASE_P(ParameterizedTests, RedeclChainClassTemplateSpec,
+                        DefaultTestValuesForRunOptions, );