[clang] [clang][ASTImport] fix issue on anonymous enum import (PR #93923)

[Qizhi Hu via cfe-commits]

https://github.com/jcsxky created https://github.com/llvm/llvm-project/pull/93923

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.

>From 7e602ae8d3c7ca0c3218d8ce9106510c43b6295b Mon Sep 17 00:00:00 2001
From: huqizhi <huqizhi at feysh.com>
Date: Fri, 31 May 2024 13:12:41 +0800
Subject: [PATCH] [clang][ASTImport] fix issue on anonymous enum import

---
 clang/lib/AST/ASTImporter.cpp           |  2 +-
 clang/unittests/AST/ASTImporterTest.cpp | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

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);