From eca94b1ff721d8ec857a5fdee8b358ce22d210aa Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?= Date: Mon, 11 Nov 2024 16:53:59 +0100 Subject: [PATCH 1/2] [clang][ASTImporter] Allow import of similar friend template with different depth The fix applies to a case that occurs when the AST contains a friend template that is contained within another template and this (outer) template has specialization. (See the added test code in the commit.) The "friend" class can have a declaration before in the AST. The friend template has the same parent as this first declaration (and is otherwise similar), but has different template depth. At AST import these declarations can be compared and import should not fail with name conflict in this case. --- clang/lib/AST/ASTImporter.cpp | 16 +++- clang/unittests/AST/ASTImporterTest.cpp | 105 ++++++++++++++++++++++++ 2 files changed, 119 insertions(+), 2 deletions(-) diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp index 35aba41f0052a..1f4ae74f3c365 100644 --- a/clang/lib/AST/ASTImporter.cpp +++ b/clang/lib/AST/ASTImporter.cpp @@ -6095,8 +6095,7 @@ ExpectedDecl ASTNodeImporter::VisitClassTemplateDecl(ClassTemplateDecl *D) { Decl::IDNS_TagFriend)) continue; - Decl *Found = FoundDecl; - auto *FoundTemplate = dyn_cast(Found); + auto *FoundTemplate = dyn_cast(FoundDecl); if (FoundTemplate) { if (!hasSameVisibilityContextAndLinkage(FoundTemplate, D)) continue; @@ -6120,6 +6119,19 @@ ExpectedDecl ASTNodeImporter::VisitClassTemplateDecl(ClassTemplateDecl *D) { // see ASTTests test ImportExistingFriendClassTemplateDef. continue; } + // When importing a friend, it is possible that multiple declarations + // with same name can co-exist in specific cases (if a template contains + // a friend template and has a specialization). For this case the + // declarations should match, except that the "template depth" is + // different. No linking of previous declaration is needed in this case. + // FIXME: This condition may need refinement. + if (D->getFriendObjectKind() != Decl::FOK_None && + FoundTemplate->getFriendObjectKind() != Decl::FOK_None && + D->getFriendObjectKind() != FoundTemplate->getFriendObjectKind() && + IsStructuralMatch(D, FoundTemplate, /*Complain=*/false, + /*IgnoreTemplateParmDepth=*/true)) + continue; + ConflictingDecls.push_back(FoundDecl); } } diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp index bf7313f882e45..49aef7441727c 100644 --- a/clang/unittests/AST/ASTImporterTest.cpp +++ b/clang/unittests/AST/ASTImporterTest.cpp @@ -10181,6 +10181,111 @@ TEST_P(ImportTemplateParmDeclDefaultValue, FromD, FromDInherited); } +TEST_P(ASTImporterOptionSpecificTestBase, + ExistingUndeclaredImportDeclaredFriend) { + Decl *ToTU = getToTuDecl( + R"( + template + struct foo; + + template + struct X { + template + friend struct foo; + }; + )", + Lang_CXX11); + Decl *FromTU = getTuDecl( + R"( + template + struct foo; + + template + struct X { + template + friend struct foo1; + }; + + X x; + )", + Lang_CXX11); + + auto *ToFr1 = FirstDeclMatcher().match(ToTU, friendDecl()); + auto *ToFrD1 = ToFr1->getFriendDecl(); + + auto *FromFr1 = FirstDeclMatcher().match(FromTU, friendDecl()); + auto *FromFr2 = LastDeclMatcher().match(FromTU, friendDecl()); + + auto *FromFrD1 = FromFr1->getFriendDecl(); + auto *FromFrD2 = FromFr2->getFriendDecl(); + + auto *Ctx1 = cast(FromFrD1->getDeclContext()); + auto *Ctx2 = cast(FromFrD2->getDeclContext()); + + ASSERT_EQ(Ctx1, Ctx2); + ASSERT_EQ(ToFrD1->getTemplateDepth(), 1u); + ASSERT_EQ(FromFrD2->getTemplateDepth(), 0u); + ASSERT_EQ(ToFrD1->getFriendObjectKind(), Decl::FOK_Undeclared); + ASSERT_EQ(FromFrD2->getFriendObjectKind(), Decl::FOK_Declared); + + auto *ToFr2Imp = Import(FromFr2, Lang_CXX11); + + EXPECT_TRUE(ToFr2Imp); +} + +TEST_P(ASTImporterOptionSpecificTestBase, + ExistingDeclaredImportUndeclaredFriend) { + Decl *ToTU = getToTuDecl( + R"( + template + struct foo; + + template + struct X { + template + friend struct foo; + }; + + X x; + )", + Lang_CXX11); + Decl *FromTU = getTuDecl( + R"( + template + struct foo; + + template + struct X { + template + friend struct foo; + }; + )", + Lang_CXX11); + + auto *ToFr1 = FirstDeclMatcher().match(ToTU, friendDecl()); + auto *ToFr2 = LastDeclMatcher().match(ToTU, friendDecl()); + + auto *ToFrD1 = ToFr1->getFriendDecl(); + auto *ToFrD2 = ToFr2->getFriendDecl(); + + auto *FromFr1 = FirstDeclMatcher().match(FromTU, friendDecl()); + auto *FromFrD1 = FromFr1->getFriendDecl(); + + auto *Ctx1 = cast(ToFrD1->getDeclContext()); + auto *Ctx2 = cast(ToFrD2->getDeclContext()); + + ASSERT_EQ(Ctx1, Ctx2); + ASSERT_EQ(FromFrD1->getTemplateDepth(), 1u); + ASSERT_EQ(ToFrD2->getTemplateDepth(), 0u); + ASSERT_EQ(FromFrD1->getFriendObjectKind(), Decl::FOK_Undeclared); + ASSERT_EQ(ToFrD2->getFriendObjectKind(), Decl::FOK_Declared); + + auto *ToFr1Imp = Import(FromFr1, Lang_CXX11); + + EXPECT_TRUE(ToFr1Imp); + EXPECT_EQ(ToFr1Imp, ToFr1); +} + INSTANTIATE_TEST_SUITE_P(ParameterizedTests, ASTImporterLookupTableTest, DefaultTestValuesForRunOptions); From ff007ab34ab5c0afaa6bf207885b08c42cfd9ebd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bal=C3=A1zs=20K=C3=A9ri?= Date: Fri, 15 Nov 2024 12:33:07 +0100 Subject: [PATCH 2/2] fixed test code --- clang/unittests/AST/ASTImporterTest.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp index 49aef7441727c..abf07d094e62c 100644 --- a/clang/unittests/AST/ASTImporterTest.cpp +++ b/clang/unittests/AST/ASTImporterTest.cpp @@ -10203,7 +10203,7 @@ TEST_P(ASTImporterOptionSpecificTestBase, template struct X { template - friend struct foo1; + friend struct foo; }; X x;