[clang] [clang][ASTImporter] skip TemplateTypeParmDecl in VisitTypeAliasTemplateDecl (PR #74919)

[Qizhi Hu via cfe-commits]

https://github.com/jcsxky updated https://github.com/llvm/llvm-project/pull/74919

>From e4e981ed4f545f3dd4cc709bab30468a8ceb3962 Mon Sep 17 00:00:00 2001
From: huqizhi <huqizhi at feysh.com>
Date: Sat, 9 Dec 2023 12:00:02 +0800
Subject: [PATCH] [clang][ASTImporter] skip TemplateTypeParmDecl in
 VisitTypeAliasTemplateDecl

---
 clang/lib/AST/ASTImporter.cpp              | 16 ++++---
 clang/lib/AST/ASTStructuralEquivalence.cpp | 16 +++++++
 clang/unittests/AST/ASTImporterTest.cpp    | 50 ++++++++++++++++++++++
 3 files changed, 77 insertions(+), 5 deletions(-)

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index f1f335118f37a4..40e5ac6ecb13e4 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -2771,9 +2771,12 @@ ASTNodeImporter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
     for (auto *FoundDecl : FoundDecls) {
       if (!FoundDecl->isInIdentifierNamespace(IDNS))
         continue;
-      if (auto *FoundAlias = dyn_cast<TypeAliasTemplateDecl>(FoundDecl))
-        return Importer.MapImported(D, FoundAlias);
-      ConflictingDecls.push_back(FoundDecl);
+      if (auto *FoundAlias = dyn_cast<TypeAliasTemplateDecl>(FoundDecl)) {
+        // if (IsStructuralMatch(D,FoundAlias)) 
+          return Importer.MapImported(D, FoundAlias);
+        
+        ConflictingDecls.push_back(FoundDecl);
+      }
     }
 
     if (!ConflictingDecls.empty()) {
@@ -9073,7 +9076,6 @@ class AttrImporter {
 
     ToAttr = FromAttr->clone(Importer.getToContext());
     ToAttr->setRange(ToRange);
-    ToAttr->setAttrName(Importer.Import(FromAttr->getAttrName()));
   }
 
   // Get the result of the previous import attempt (can be used only once).
@@ -9223,6 +9225,11 @@ Expected<Attr *> ASTImporter::Import(const Attr *FromAttr) {
     AI.castAttrAs<CountedByAttr>()->setCountedByFieldLoc(SR.get());
     break;
   }
+  case attr::AlignValue:{
+    auto *From = cast<AlignValueAttr>(FromAttr);
+    AI.importAttr(From,AI.importArg(From->getAlignment()).value());
+    break;
+  }
 
   default: {
     // The default branch works for attributes that have no arguments to import.
@@ -9391,7 +9398,6 @@ Expected<Decl *> ASTImporter::Import(Decl *FromD) {
     setImportDeclError(FromD, *Error);
     return make_error<ASTImportError>(*Error);
   }
-
   // Make sure that ImportImpl registered the imported decl.
   assert(ImportedDecls.count(FromD) != 0 && "Missing call to MapImported?");
   if (auto Error = ImportAttrs(ToD, FromD))
diff --git a/clang/lib/AST/ASTStructuralEquivalence.cpp b/clang/lib/AST/ASTStructuralEquivalence.cpp
index 6bb4bf14b873d7..5d6c3f35e50832 100644
--- a/clang/lib/AST/ASTStructuralEquivalence.cpp
+++ b/clang/lib/AST/ASTStructuralEquivalence.cpp
@@ -1977,6 +1977,22 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                   D2->getTemplatedDecl()->getType());
 }
 
+// static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
+//                                      TypeAliasTemplateDecl *D1,
+//                                      TypeAliasTemplateDecl *D2) {
+//   if (!IsStructurallyEquivalent(Context, D1->getDeclName(), D2->getDeclName()))
+//     return false;
+
+//   // Check the templated declaration.
+//   if (!IsStructurallyEquivalent(Context, D1->getTemplatedDecl(),
+//                                 D2->getTemplatedDecl()))
+//     return false;
+
+//   // Check template parameters.
+//   return IsStructurallyEquivalent(Context, D1->getTemplateParameters(),
+//                                   D2->getTemplateParameters());
+// }
+
 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                      ConceptDecl *D1,
                                      ConceptDecl *D2) {
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 4dd7510bf8ddf8..454a4d42d77520 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -9284,6 +9284,56 @@ TEST_P(ASTImporterOptionSpecificTestBase,
   // EXPECT_EQ(ToF1Imported->getPreviousDecl(), ToF1);
 }
 
+// TEST_P(ASTImporterOptionSpecificTestBase, ImportTypeAliasTemplateDecl) {
+//   const char *Code =
+//       R"(
+//       struct S;
+//       template <typename>
+//       using Callable = S;
+//       template <typename Callable>
+//       int bindingFunctionVTable;
+//       )";
+//   Decl *FromTU = getTuDecl(Code, Lang_CXX17);
+
+//   auto *FromCallable1 = FirstDeclMatcher<TypeAliasTemplateDecl>().match(
+//       FromTU, typeAliasTemplateDecl(hasName("Callable")));
+
+//   auto *FromCallable2 = FirstDeclMatcher<TemplateTypeParmDecl>().match(
+//       FromTU, templateTypeParmDecl(hasName("Callable")));
+
+//   auto *ToCallable2 = Import(FromCallable2, Lang_CXX17);
+//   auto *ToCallable1 = Import(FromCallable1, Lang_CXX17);
+//   EXPECT_TRUE(ToCallable1);
+//   EXPECT_TRUE(ToCallable2);
+// }
+
+// TEST_P(ASTImporterOptionSpecificTestBase, X) {
+//   const char *CodeFrom1 =
+//       R"(
+//       template <typename>
+//       bool A = A<int>;
+//       )";
+//   const char *CodeFrom2 =
+//       R"(
+//       template <typename>
+//       bool A = A<int>;
+//       )";
+//   Decl *From1TU = getTuDecl(CodeFrom1, Lang_CXX17, "input1.cc");
+//   Decl *ToTuDecl = getToTuDecl(CodeFrom2, Lang_CXX17);
+
+//   auto *From1A = FirstDeclMatcher<VarTemplateSpecializationDecl>().match(
+//       From1TU, varTemplateSpecializationDecl(hasName("A")));
+
+//   // auto *From2A = FirstDeclMatcher<VarTemplateSpecializationDecl>().match(
+//   //     From2TU, varTemplateSpecializationDecl(hasName("A")));
+
+//   auto *ToA = Import(From1A, Lang_CXX17);
+//   // auto *ToCallable1 = Import(FromCallable1, Lang_CXX17);
+//   EXPECT_TRUE(ToA);
+//   // ToA = Import(From2A, Lang_CXX17);
+//   // EXPECT_TRUE(ToA);
+// }
+
 INSTANTIATE_TEST_SUITE_P(ParameterizedTests, ASTImporterLookupTableTest,
                          DefaultTestValuesForRunOptions);