[clang] 869d168 - [clang][ASTImporter] Fix crash when import `VarTemplateDecl` in record (#67522)

[via cfe-commits]

Author: Qizhi Hu
Date: 2023-10-07T09:36:04+08:00
New Revision: 869d1680edb0cc264f01fc6e59f0a1b93330c6da

URL: https://github.com/llvm/llvm-project/commit/869d1680edb0cc264f01fc6e59f0a1b93330c6da
DIFF: https://github.com/llvm/llvm-project/commit/869d1680edb0cc264f01fc6e59f0a1b93330c6da.diff

LOG: [clang][ASTImporter] Fix crash when import `VarTemplateDecl` in record (#67522)

[clang][ASTImporter] Fix crash when import `VarTemplateDecl` in record
static VarTemplateDecl in record isn't a definition, when imported
before, it will crash in `ASTContext::setTemplateOrSpecializationInfo`
due to setting specialization while it already exists. This patch skip
this specific case.

Co-authored-by: huqizhi <836744285 at qq.com>

Added: 
    

Modified: 
    clang/lib/AST/ASTImporter.cpp
    clang/unittests/AST/ASTImporterTest.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 29b9d492904f5c8..6c5aaee3f42f218 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -6242,6 +6242,9 @@ ExpectedDecl ASTNodeImporter::VisitVarTemplateDecl(VarTemplateDecl *D) {
           // FIXME Check for ODR error if the two definitions have
           // 
diff erent initializers?
           return Importer.MapImported(D, FoundDef);
+        if (FoundTemplate->getDeclContext()->isRecord() &&
+            D->getDeclContext()->isRecord())
+          return Importer.MapImported(D, FoundTemplate);
 
         FoundByLookup = FoundTemplate;
         break;

diff  --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index e9e8cac2a15bc70..393ed44de3f1831 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -4988,6 +4988,37 @@ TEST_P(ASTImporterOptionSpecificTestBase,
   }
 }
 
+TEST_P(ImportFriendClasses, RecordVarTemplateDecl) {
+  Decl *ToTU = getToTuDecl(
+      R"(
+      template <class T>
+      class A {
+      public:
+        template <class U>
+        static constexpr bool X = true;
+      };
+      )",
+      Lang_CXX14);
+
+  auto *ToTUX = FirstDeclMatcher<VarTemplateDecl>().match(
+      ToTU, varTemplateDecl(hasName("X")));
+  Decl *FromTU = getTuDecl(
+      R"(
+      template <class T>
+      class A {
+      public:
+        template <class U>
+        static constexpr bool X = true;
+      };
+      )",
+      Lang_CXX14, "input1.cc");
+  auto *FromX = FirstDeclMatcher<VarTemplateDecl>().match(
+      FromTU, varTemplateDecl(hasName("X")));
+  auto *ToX = Import(FromX, Lang_CXX11);
+  EXPECT_TRUE(ToX);
+  EXPECT_EQ(ToTUX, ToX);
+}
+
 TEST_P(ASTImporterOptionSpecificTestBase, VarTemplateParameterDeclContext) {
   constexpr auto Code =
       R"(