[clang][ASTImport] fix issue on anonymous enum import

[jcsxky]

Don't skip searching in ToContext during importing EnumDecl. And IsStructuralMatch in StructralEquivalence can make sure to determine whether the found result is match or not.

[llvmbot]

@llvm/pr-subscribers-clang

Author: Qizhi Hu (jcsxky)

Changes

Don't skip searching in ToContext during importing EnumDecl. And IsStructuralMatch in StructralEquivalence can make sure to determine whether the found result is match or not.

---

Full diff: https://github.com/llvm/llvm-project/pull/93923.diff

2 Files Affected:

• (modified) clang/lib/AST/ASTImporter.cpp (+1-1)
• (modified) clang/unittests/AST/ASTImporterTest.cpp (+21)

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index cab5ee6047956..3b9080e09b331 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -2929,7 +2929,7 @@ ExpectedDecl ASTNodeImporter::VisitEnumDecl(EnumDecl *D) {
 
   // We may already have an enum of the same name; try to find and match it.
   EnumDecl *PrevDecl = nullptr;
-  if (!DC->isFunctionOrMethod() && SearchName) {
+  if (!DC->isFunctionOrMethod()) {
     SmallVector<NamedDecl *, 4> ConflictingDecls;
     auto FoundDecls =
         Importer.findDeclsInToCtx(DC, SearchName);
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 3dc1c336365d1..4cee0b75653a5 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -9674,6 +9674,27 @@ TEST_P(ASTImporterOptionSpecificTestBase, ImportInstantiatedFromMember) {
   EXPECT_TRUE(ImportedPartialSpecialization->getInstantiatedFromMember());
 }
 
+TEST_P(ASTImporterOptionSpecificTestBase, ImportAnonymousEnum) {
+  const char *ToCode =
+      R"(
+      struct A {
+        enum { E1,E2} x;
+      };
+      )";
+  (void)getToTuDecl(ToCode, Lang_CXX11);
+  const char *Code =
+      R"(
+      struct A {
+        enum { E1,E2} x;
+      };
+      )";
+  Decl *FromTU = getTuDecl(Code, Lang_CXX11);
+  auto *FromE = FirstDeclMatcher<EnumDecl>().match(FromTU, enumDecl());
+  auto *ToE = Import(FromE, Lang_CXX11);
+  ASSERT_TRUE(ToE);
+  EXPECT_FALSE(ToE->enumerators().empty());
+}
+
 INSTANTIATE_TEST_SUITE_P(ParameterizedTests, ASTImporterLookupTableTest,
                          DefaultTestValuesForRunOptions);
 

[balazske]

Does this work on the following code?

     struct A {
        enum { E1,E2 } x;
        enum { E3,E4 } y;
      };

[balazske]

It is more safe to get the EnumDecl in the ToTU before the import (ToExistingE) and after import check if it is equal to ToE.

[jcsxky]

Done.

[jcsxky]

Does this work on the following code?

     struct A {
        enum { E1,E2 } x;
        enum { E3,E4 } y;
      };

I have updated testcase according to your suggestion to demonstrate this solution works correctly on the testcase above.

[balazske]

The change looks good, only the test can be made more exact.

[balazske]

Suggested change

EXPECT_FALSE(ImportedE->enumerators().empty());

This check is not necessary (if the other is here).

[jcsxky]

Updated.

[balazske]

I would like to have a similar check (and a new import and check) with the other enum. This ensures that the enums are not mixed somehow by the import.

[jcsxky]

Import test on the other enum has been added to make this test completely.