https://github.com/timon-ul updated https://github.com/llvm/llvm-project/pull/177273
>From ff644a0ff41d1521436567b10501e112bda93759 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Sat, 17 Jan 2026 03:16:06 +0100 Subject: [PATCH 1/9] First step towards indexing template instantiations --- clang-tools-extra/clangd/XRefs.cpp | 42 +++++++++++-------- .../clangd/index/SymbolCollector.cpp | 13 +++++- .../clangd/unittests/XRefsTests.cpp | 20 +++++++++ clang/include/clang/Index/IndexingOptions.h | 2 +- clang/lib/Index/IndexDecl.cpp | 33 ++++++++++++++- clang/lib/Index/IndexTypeSourceInfo.cpp | 9 ++++ clang/lib/Index/IndexingContext.cpp | 4 +- 7 files changed, 98 insertions(+), 25 deletions(-) diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp index 8a24d19a7d129..a517abba7762a 100644 --- a/clang-tools-extra/clangd/XRefs.cpp +++ b/clang-tools-extra/clangd/XRefs.cpp @@ -306,25 +306,31 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, RelationsRequest Req; Req.Predicate = Predicate; - Req.Subjects = std::move(IDs); + llvm::DenseSet<SymbolID> RecursiveSearch = std::move(IDs); std::vector<LocatedSymbol> Results; - Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) { - auto DeclLoc = - indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath); - if (!DeclLoc) { - elog("Find overrides: {0}", DeclLoc.takeError()); - return; - } - Results.emplace_back(); - Results.back().Name = Object.Name.str(); - Results.back().PreferredDeclaration = *DeclLoc; - auto DefLoc = indexToLSPLocation(Object.Definition, MainFilePath); - if (!DefLoc) { - elog("Failed to convert location: {0}", DefLoc.takeError()); - return; - } - Results.back().Definition = *DefLoc; - }); + + while (!RecursiveSearch.empty()) { + Req.Subjects = std::move(RecursiveSearch); + RecursiveSearch = {}; + Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) { + auto DeclLoc = + indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath); + if (!DeclLoc) { + elog("Find overrides: {0}", DeclLoc.takeError()); + return; + } + Results.emplace_back(); + Results.back().Name = Object.Name.str(); + Results.back().PreferredDeclaration = *DeclLoc; + auto DefLoc = indexToLSPLocation(Object.Definition, MainFilePath); + if (!DefLoc) { + elog("Failed to convert location: {0}", DefLoc.takeError()); + return; + } + Results.back().Definition = *DefLoc; + RecursiveSearch.insert(Object.ID); + }); + } return Results; } diff --git a/clang-tools-extra/clangd/index/SymbolCollector.cpp b/clang-tools-extra/clangd/index/SymbolCollector.cpp index bd974e4c18818..8d905ad1fea10 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.cpp +++ b/clang-tools-extra/clangd/index/SymbolCollector.cpp @@ -603,6 +603,12 @@ bool SymbolCollector::handleDeclOccurrence( assert(ASTCtx && PP && HeaderFileURIs); assert(CompletionAllocator && CompletionTUInfo); assert(ASTNode.OrigD); + const NamedDecl *NOD = dyn_cast<NamedDecl>(ASTNode.OrigD); + std::string NameOD = ""; + if (NOD){ + NameOD = printName(*ASTCtx, *NOD); + NameOD += printTemplateSpecializationArgs(*NOD); + } // Indexing API puts canonical decl into D, which might not have a valid // source location for implicit/built-in decls. Fallback to original decl in // such cases. @@ -896,9 +902,12 @@ void SymbolCollector::processRelations( // in the index and find nothing, but that's a situation they // probably need to handle for other reasons anyways. // We currently do (B) because it's simpler. - if (*RKind == RelationKind::BaseOf) + if (*RKind == RelationKind::BaseOf) { + std::string SubjectName = printName(*ASTCtx, ND) + printTemplateSpecializationArgs(ND); + const auto *Sym = Symbols.find(ObjectID); + std::string ObjectName = (Sym->Scope + Sym->Name + Sym->TemplateSpecializationArgs).str(); this->Relations.insert({ID, *RKind, ObjectID}); - else if (*RKind == RelationKind::OverriddenBy) + } else if (*RKind == RelationKind::OverriddenBy) this->Relations.insert({ObjectID, *RKind, ID}); } } diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 4106c6cf7b2d0..5cefbeb78071a 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -1958,6 +1958,26 @@ TEST(FindImplementations, InheritanceObjC) { Code.range("protocolDef")))); } +TEST(FindImplementations, InheritanceRecursive) { + Annotations Main(R"cpp( + template <typename... T> + struct Inherit : T... {}; + + struct Al$Alpha^pha {}; + + struct $Impl1[[impl]]: Inherit<Alpha> {}; + )cpp"); + + TestTU TU; + TU.Code = std::string(Main.code()); + auto AST = TU.build(); + auto Index = TU.index(); + + EXPECT_THAT( + findImplementations(AST, Main.point("Alpha"), Index.get()), + ElementsAre(sym("impl", Main.range("Impl1"), Main.range("Impl1")))); +} + TEST(FindImplementations, CaptureDefinition) { llvm::StringRef Test = R"cpp( struct Base { diff --git a/clang/include/clang/Index/IndexingOptions.h b/clang/include/clang/Index/IndexingOptions.h index c670797e9fa60..1094ec46dc9af 100644 --- a/clang/include/clang/Index/IndexingOptions.h +++ b/clang/include/clang/Index/IndexingOptions.h @@ -27,7 +27,7 @@ struct IndexingOptions { SystemSymbolFilterKind SystemSymbolFilter = SystemSymbolFilterKind::DeclarationsOnly; bool IndexFunctionLocals = false; - bool IndexImplicitInstantiation = false; + bool IndexImplicitInstantiation = true; bool IndexMacros = true; // Whether to index macro definitions in the Preprocessor when preprocessor // callback is not available (e.g. after parsing has finished). Note that diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp index df875e0b40079..51b400f915bd3 100644 --- a/clang/lib/Index/IndexDecl.cpp +++ b/clang/lib/Index/IndexDecl.cpp @@ -14,6 +14,7 @@ #include "clang/AST/DeclVisitor.h" #include "clang/Index/IndexDataConsumer.h" #include "clang/Index/IndexSymbol.h" +#include "llvm/Support/Casting.h" using namespace clang; using namespace index; @@ -734,7 +735,37 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> { indexTemplateParameters(Params, Parent); } - return Visit(Parent); + bool shouldContinue = Visit(Parent); + if (!shouldContinue) + return false; + + // TODO: cleanup maybe, so far copy paste from + // RecursiveASTVisitor::TraverseTemplateInstantiation, we have technically + // `shouldIndexImplicitInstantiation()` available here, but the logic is + // different and I am confused. + if (const auto *CTD = llvm::dyn_cast<ClassTemplateDecl>(D)) + for (auto *SD : CTD->specializations()) + for (auto *RD : SD->redecls()) { + assert(!cast<CXXRecordDecl>(RD)->isInjectedClassName()); + switch (cast<ClassTemplateSpecializationDecl>(RD) + ->getSpecializationKind()) { + // Visit the implicit instantiations with the requested pattern. + case TSK_Undeclared: + case TSK_ImplicitInstantiation: + Visit(RD); + break; + + // We don't need to do anything on an explicit instantiation + // or explicit specialization because there will be an explicit + // node for it elsewhere. + case TSK_ExplicitInstantiationDeclaration: + case TSK_ExplicitInstantiationDefinition: + case TSK_ExplicitSpecialization: + break; + } + } + + return true; } bool VisitConceptDecl(const ConceptDecl *D) { diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp index c9ad36b5406c5..be3d75e84c351 100644 --- a/clang/lib/Index/IndexTypeSourceInfo.cpp +++ b/clang/lib/Index/IndexTypeSourceInfo.cpp @@ -10,6 +10,7 @@ #include "clang/AST/ASTConcept.h" #include "clang/AST/PrettyPrinter.h" #include "clang/AST/RecursiveASTVisitor.h" +#include "clang/AST/TypeBase.h" #include "clang/AST/TypeLoc.h" #include "clang/Sema/HeuristicResolver.h" #include "llvm/ADT/ScopeExit.h" @@ -193,6 +194,14 @@ class TypeIndexer : public RecursiveASTVisitor<TypeIndexer> { return true; } + // bool TraverseSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL, + // bool TraverseQualifier) { + // auto Type = TL.getAs<TemplateSpecializationTypeLoc>(); + // if (!Type.isNull()) + // TraverseTemplateSpecializationTypeLoc(Type, TraverseQualifier); + // return true; + // } + bool VisitDeducedTemplateSpecializationTypeLoc(DeducedTemplateSpecializationTypeLoc TL) { auto *T = TL.getTypePtr(); if (!T) diff --git a/clang/lib/Index/IndexingContext.cpp b/clang/lib/Index/IndexingContext.cpp index bdd6c5acf1d34..c6843cf46cf8e 100644 --- a/clang/lib/Index/IndexingContext.cpp +++ b/clang/lib/Index/IndexingContext.cpp @@ -402,9 +402,7 @@ bool IndexingContext::handleDeclOccurrence(const Decl *D, SourceLocation Loc, if (!OrigD) OrigD = D; - if (isTemplateImplicitInstantiation(D)) { - if (!IsRef) - return true; + if (isTemplateImplicitInstantiation(D) && IsRef) { D = adjustTemplateImplicitInstantiation(D); if (!D) return true; >From 511ba41d9153e13247fd5fb9eb61ec330dfb4e21 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Sat, 17 Jan 2026 03:20:22 +0100 Subject: [PATCH 2/9] New methods for visiting SubstTemplateType --- clang/lib/Index/IndexTypeSourceInfo.cpp | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp index be3d75e84c351..e16d8ac791898 100644 --- a/clang/lib/Index/IndexTypeSourceInfo.cpp +++ b/clang/lib/Index/IndexTypeSourceInfo.cpp @@ -194,13 +194,21 @@ class TypeIndexer : public RecursiveASTVisitor<TypeIndexer> { return true; } - // bool TraverseSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL, - // bool TraverseQualifier) { - // auto Type = TL.getAs<TemplateSpecializationTypeLoc>(); - // if (!Type.isNull()) - // TraverseTemplateSpecializationTypeLoc(Type, TraverseQualifier); - // return true; - // } + bool VisitSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL) { + auto QT = TL.getTypePtr()->getReplacementType(); + auto *T = QT->getAsNonAliasTemplateSpecializationType(); + if (!T) + return true; + HandleTemplateSpecializationTypeLoc( + T->getTemplateName(), TL.getTemplateNameLoc(), T->getAsCXXRecordDecl(), + T->isTypeAlias()); + return true; + } + + bool TraverseSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL, + bool TraverseQualifier) { + return true; + } bool VisitDeducedTemplateSpecializationTypeLoc(DeducedTemplateSpecializationTypeLoc TL) { auto *T = TL.getTypePtr(); >From b5ffe8fb17140df17999a61693064bec25248ec2 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Wed, 21 Jan 2026 23:20:57 +0100 Subject: [PATCH 3/9] Implemented template inheritance handling --- .../clangd/index/SymbolCollector.cpp | 22 ++++++------ .../clangd/index/SymbolCollector.h | 2 +- .../clangd/unittests/XRefsTests.cpp | 36 ++++++++++++++----- clang/include/clang/Index/IndexingOptions.h | 2 +- clang/lib/Index/IndexDecl.cpp | 33 +++++++---------- clang/lib/Index/IndexTypeSourceInfo.cpp | 19 +++++----- 6 files changed, 61 insertions(+), 53 deletions(-) diff --git a/clang-tools-extra/clangd/index/SymbolCollector.cpp b/clang-tools-extra/clangd/index/SymbolCollector.cpp index 8d905ad1fea10..f8ff9bf277ceb 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.cpp +++ b/clang-tools-extra/clangd/index/SymbolCollector.cpp @@ -603,12 +603,7 @@ bool SymbolCollector::handleDeclOccurrence( assert(ASTCtx && PP && HeaderFileURIs); assert(CompletionAllocator && CompletionTUInfo); assert(ASTNode.OrigD); - const NamedDecl *NOD = dyn_cast<NamedDecl>(ASTNode.OrigD); - std::string NameOD = ""; - if (NOD){ - NameOD = printName(*ASTCtx, *NOD); - NameOD += printTemplateSpecializationArgs(*NOD); - } + // Indexing API puts canonical decl into D, which might not have a valid // source location for implicit/built-in decls. Fallback to original decl in // such cases. @@ -679,7 +674,7 @@ bool SymbolCollector::handleDeclOccurrence( // refs, because the indexing code only populates relations for specific // occurrences. For example, RelationBaseOf is only populated for the // occurrence inside the base-specifier. - processRelations(*ND, ID, Relations); + processRelations(ID, *ASTNode.OrigD, Relations); bool CollectRef = static_cast<bool>(Opts.RefFilter & toRefKind(Roles)); // Unlike other fields, e.g. Symbols (which use spelling locations), we use @@ -881,7 +876,7 @@ bool SymbolCollector::handleMacroOccurrence(const IdentifierInfo *Name, } void SymbolCollector::processRelations( - const NamedDecl &ND, const SymbolID &ID, + const SymbolID &ID, const Decl &OrigD, ArrayRef<index::SymbolRelation> Relations) { for (const auto &R : Relations) { auto RKind = indexableRelation(R); @@ -903,10 +898,15 @@ void SymbolCollector::processRelations( // probably need to handle for other reasons anyways. // We currently do (B) because it's simpler. if (*RKind == RelationKind::BaseOf) { - std::string SubjectName = printName(*ASTCtx, ND) + printTemplateSpecializationArgs(ND); - const auto *Sym = Symbols.find(ObjectID); - std::string ObjectName = (Sym->Scope + Sym->Name + Sym->TemplateSpecializationArgs).str(); this->Relations.insert({ID, *RKind, ObjectID}); + // If the Subject is a template, we also want a relation to the + // template instantiation (OrigD) to record inheritance chains. + if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(&OrigD); + CTSD && !CTSD->isExplicitSpecialization()) { + auto OrigID = getSymbolIDCached(&OrigD); + if (OrigID) + this->Relations.insert({OrigID, *RKind, ObjectID}); + } } else if (*RKind == RelationKind::OverriddenBy) this->Relations.insert({ObjectID, *RKind, ID}); } diff --git a/clang-tools-extra/clangd/index/SymbolCollector.h b/clang-tools-extra/clangd/index/SymbolCollector.h index 4d51d747639b1..54a12ba122240 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.h +++ b/clang-tools-extra/clangd/index/SymbolCollector.h @@ -169,7 +169,7 @@ class SymbolCollector : public index::IndexDataConsumer { bool IsMainFileSymbol); void addDefinition(const NamedDecl &, const Symbol &DeclSymbol, bool SkipDocCheck); - void processRelations(const NamedDecl &ND, const SymbolID &ID, + void processRelations(const SymbolID &ID, const Decl &OrigD, ArrayRef<index::SymbolRelation> Relations); std::optional<SymbolLocation> getTokenLocation(SourceLocation TokLoc); diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 5cefbeb78071a..9a382f4a8c257 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -1878,8 +1878,8 @@ TEST(FindImplementations, Inheritance) { virtual void B$2^ar(); void Concrete(); // No implementations for concrete methods. }; - struct Child2 : Child1 { - void $3[[Foo]]() override; + struct $0[[Child2]] : Child1 { + void $1[[$3[[Foo]]]]() override; void $2[[Bar]]() override; }; void FromReference() { @@ -1958,14 +1958,27 @@ TEST(FindImplementations, InheritanceObjC) { Code.range("protocolDef")))); } -TEST(FindImplementations, InheritanceRecursive) { +TEST(FindImplementations, InheritanceTemplate) { Annotations Main(R"cpp( + class Fi$First^rst {}; + + class Sec$Second^ond {}; + + class Th$Third^ird {}; + template <typename... T> - struct Inherit : T... {}; + struct $Third[[Inherit]] : T... {}; + + template struct $First[[Inherit]]<First>; + + template<> + struct $Second[[Inherit]]<Second> : Second {}; - struct Al$Alpha^pha {}; + class $First[[Battler]] : Inherit<First> {}; - struct $Impl1[[impl]]: Inherit<Alpha> {}; + class $Second[[Beatrice]] : Inherit<Second> {}; + + class $Third[[Maria]] : Inherit<Third> {}; )cpp"); TestTU TU; @@ -1973,9 +1986,14 @@ TEST(FindImplementations, InheritanceRecursive) { auto AST = TU.build(); auto Index = TU.index(); - EXPECT_THAT( - findImplementations(AST, Main.point("Alpha"), Index.get()), - ElementsAre(sym("impl", Main.range("Impl1"), Main.range("Impl1")))); + EXPECT_THAT(findImplementations(AST, Main.point("First"), Index.get()), + UnorderedPointwise(declRange(), Main.ranges("First"))); + + EXPECT_THAT(findImplementations(AST, Main.point("Second"), Index.get()), + UnorderedPointwise(declRange(), Main.ranges("Second"))); + + EXPECT_THAT(findImplementations(AST, Main.point("Third"), Index.get()), + UnorderedPointwise(declRange(), Main.ranges("Third"))); } TEST(FindImplementations, CaptureDefinition) { diff --git a/clang/include/clang/Index/IndexingOptions.h b/clang/include/clang/Index/IndexingOptions.h index 1094ec46dc9af..c670797e9fa60 100644 --- a/clang/include/clang/Index/IndexingOptions.h +++ b/clang/include/clang/Index/IndexingOptions.h @@ -27,7 +27,7 @@ struct IndexingOptions { SystemSymbolFilterKind SystemSymbolFilter = SystemSymbolFilterKind::DeclarationsOnly; bool IndexFunctionLocals = false; - bool IndexImplicitInstantiation = true; + bool IndexImplicitInstantiation = false; bool IndexMacros = true; // Whether to index macro definitions in the Preprocessor when preprocessor // callback is not available (e.g. after parsing has finished). Note that diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp index 51b400f915bd3..f0fe1d0af7791 100644 --- a/clang/lib/Index/IndexDecl.cpp +++ b/clang/lib/Index/IndexDecl.cpp @@ -739,30 +739,21 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> { if (!shouldContinue) return false; - // TODO: cleanup maybe, so far copy paste from - // RecursiveASTVisitor::TraverseTemplateInstantiation, we have technically - // `shouldIndexImplicitInstantiation()` available here, but the logic is - // different and I am confused. + // Only check instantiation if D is canonical to prevent infinite cycling + if (D != D->getCanonicalDecl()) + return true; + if (const auto *CTD = llvm::dyn_cast<ClassTemplateDecl>(D)) for (auto *SD : CTD->specializations()) for (auto *RD : SD->redecls()) { - assert(!cast<CXXRecordDecl>(RD)->isInjectedClassName()); - switch (cast<ClassTemplateSpecializationDecl>(RD) - ->getSpecializationKind()) { - // Visit the implicit instantiations with the requested pattern. - case TSK_Undeclared: - case TSK_ImplicitInstantiation: - Visit(RD); - break; - - // We don't need to do anything on an explicit instantiation - // or explicit specialization because there will be an explicit - // node for it elsewhere. - case TSK_ExplicitInstantiationDeclaration: - case TSK_ExplicitInstantiationDefinition: - case TSK_ExplicitSpecialization: - break; - } + auto *CTSD = cast<ClassTemplateSpecializationDecl>(RD); + // For now we are only interested in instantiations with inheritance. + if (!CTSD->hasDefinition() || CTSD->bases().empty()) + continue; + // Explicit specialization is handled elsewhere + if (CTSD->isExplicitSpecialization()) + continue; + Visit(RD); } return true; diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp index e16d8ac791898..bb62b7d6f8d87 100644 --- a/clang/lib/Index/IndexTypeSourceInfo.cpp +++ b/clang/lib/Index/IndexTypeSourceInfo.cpp @@ -194,19 +194,18 @@ class TypeIndexer : public RecursiveASTVisitor<TypeIndexer> { return true; } - bool VisitSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL) { - auto QT = TL.getTypePtr()->getReplacementType(); - auto *T = QT->getAsNonAliasTemplateSpecializationType(); + bool TraverseSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL, + bool TraverseQualifier) { + const auto *T = TL.getTypePtr(); if (!T) return true; - HandleTemplateSpecializationTypeLoc( - T->getTemplateName(), TL.getTemplateNameLoc(), T->getAsCXXRecordDecl(), - T->isTypeAlias()); - return true; - } + auto QT = T->getReplacementType(); + if (QT.isNull()) + return true; + + IndexCtx.handleReference(QT->getAsCXXRecordDecl(), TL.getNameLoc(), Parent, + ParentDC, SymbolRoleSet(), Relations); - bool TraverseSubstTemplateTypeParmTypeLoc(SubstTemplateTypeParmTypeLoc TL, - bool TraverseQualifier) { return true; } >From 53c04f63a1a5583d4200a86e7d065e5ec11b4cd2 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Thu, 22 Jan 2026 00:05:17 +0100 Subject: [PATCH 4/9] Errors do not meant we shouldn't keep recursing --- clang-tools-extra/clangd/XRefs.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp index a517abba7762a..79decd35baadd 100644 --- a/clang-tools-extra/clangd/XRefs.cpp +++ b/clang-tools-extra/clangd/XRefs.cpp @@ -313,6 +313,7 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, Req.Subjects = std::move(RecursiveSearch); RecursiveSearch = {}; Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) { + RecursiveSearch.insert(Object.ID); auto DeclLoc = indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath); if (!DeclLoc) { @@ -328,7 +329,6 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, return; } Results.back().Definition = *DefLoc; - RecursiveSearch.insert(Object.ID); }); } return Results; >From 6502814383b0bc95a0f69c05bf0aa126e4a9fa51 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Thu, 22 Jan 2026 00:28:59 +0100 Subject: [PATCH 5/9] Preventing refs for implicit instantiations --- clang-tools-extra/clangd/index/SymbolCollector.cpp | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/clang-tools-extra/clangd/index/SymbolCollector.cpp b/clang-tools-extra/clangd/index/SymbolCollector.cpp index f8ff9bf277ceb..30f34324f5e58 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.cpp +++ b/clang-tools-extra/clangd/index/SymbolCollector.cpp @@ -677,6 +677,13 @@ bool SymbolCollector::handleDeclOccurrence( processRelations(ID, *ASTNode.OrigD, Relations); bool CollectRef = static_cast<bool>(Opts.RefFilter & toRefKind(Roles)); + // For now we only want the bare minimum of information for a class + // instantiation such that we have symbols for the `BaseOf` relation. + if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(D); + CTSD && CTSD->hasDefinition() && !CTSD->bases().empty() && + !CTSD->isExplicitSpecialization()) { + CollectRef = false; + } // Unlike other fields, e.g. Symbols (which use spelling locations), we use // file locations for references (as it aligns the behavior of clangd's // AST-based xref). >From 195fd77fca387bff1a4594437b0fb433ef243331 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Thu, 22 Jan 2026 11:05:50 +0100 Subject: [PATCH 6/9] More careful handling of casts --- clang/lib/Index/IndexDecl.cpp | 5 ++--- clang/lib/Index/IndexTypeSourceInfo.cpp | 9 +++++---- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp index f0fe1d0af7791..35f8f7e43ed7d 100644 --- a/clang/lib/Index/IndexDecl.cpp +++ b/clang/lib/Index/IndexDecl.cpp @@ -14,7 +14,6 @@ #include "clang/AST/DeclVisitor.h" #include "clang/Index/IndexDataConsumer.h" #include "clang/Index/IndexSymbol.h" -#include "llvm/Support/Casting.h" using namespace clang; using namespace index; @@ -746,9 +745,9 @@ class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> { if (const auto *CTD = llvm::dyn_cast<ClassTemplateDecl>(D)) for (auto *SD : CTD->specializations()) for (auto *RD : SD->redecls()) { - auto *CTSD = cast<ClassTemplateSpecializationDecl>(RD); + auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD); // For now we are only interested in instantiations with inheritance. - if (!CTSD->hasDefinition() || CTSD->bases().empty()) + if (!CTSD || !CTSD->hasDefinition() || CTSD->bases().empty()) continue; // Explicit specialization is handled elsewhere if (CTSD->isExplicitSpecialization()) diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp index bb62b7d6f8d87..ee70bc05914ad 100644 --- a/clang/lib/Index/IndexTypeSourceInfo.cpp +++ b/clang/lib/Index/IndexTypeSourceInfo.cpp @@ -202,11 +202,12 @@ class TypeIndexer : public RecursiveASTVisitor<TypeIndexer> { auto QT = T->getReplacementType(); if (QT.isNull()) return true; + auto *CXXRD = QT->getAsCXXRecordDecl(); + if (!CXXRD) + return true; - IndexCtx.handleReference(QT->getAsCXXRecordDecl(), TL.getNameLoc(), Parent, - ParentDC, SymbolRoleSet(), Relations); - - return true; + return IndexCtx.handleReference(CXXRD, TL.getNameLoc(), Parent, ParentDC, + SymbolRoleSet(), Relations); } bool VisitDeducedTemplateSpecializationTypeLoc(DeducedTemplateSpecializationTypeLoc TL) { >From 178fe678a5bd3b9bcb59192be43df18a397fedb2 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Mon, 26 Jan 2026 14:47:35 +0100 Subject: [PATCH 7/9] Fixed infinite recursion --- clang-tools-extra/clangd/XRefs.cpp | 3 ++ .../clangd/unittests/XRefsTests.cpp | 36 +++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp index 79decd35baadd..69f5dbc954692 100644 --- a/clang-tools-extra/clangd/XRefs.cpp +++ b/clang-tools-extra/clangd/XRefs.cpp @@ -306,6 +306,7 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, RelationsRequest Req; Req.Predicate = Predicate; + llvm::DenseSet<SymbolID> SeenIDs; llvm::DenseSet<SymbolID> RecursiveSearch = std::move(IDs); std::vector<LocatedSymbol> Results; @@ -313,6 +314,8 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, Req.Subjects = std::move(RecursiveSearch); RecursiveSearch = {}; Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) { + if (!SeenIDs.insert(Object.ID).second) + return; RecursiveSearch.insert(Object.ID); auto DeclLoc = indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath); diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 9a382f4a8c257..2f52169214f7b 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -1923,6 +1923,42 @@ TEST(FindImplementations, Inheritance) { } } +TEST(FindImplementations, InheritanceRecursion) { + // Make sure inheritance is followed, but does not diverge. + llvm::StringRef Test = R"cpp( + template <int> + struct [[Ev^en]]; + + template <int> + struct [[Odd]]; + + template <> + struct Even<0> { + static const bool value = true; + }; + + template <> + struct Odd<0> { + static const bool value = false; + }; + + template <int I> + struct Even : Odd<I - 1> {}; + + template <int I> + struct Odd : Even<I - 1> {}; + + constexpr bool Answer = Even<42>::value; + )cpp"; + + Annotations Code(Test); + auto TU = TestTU::withCode(Code.code()); + auto AST = TU.build(); + auto Index = TU.index(); + EXPECT_THAT(findImplementations(AST, Code.point(), Index.get()), + UnorderedPointwise(declRange(), Code.ranges())); +} + TEST(FindImplementations, InheritanceObjC) { llvm::StringRef Test = R"objc( @interface $base^Base >From 2e6a49c51127ed55970eaa5134d36ad3a13e02f0 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Tue, 27 Jan 2026 17:11:32 +0100 Subject: [PATCH 8/9] Added defRange matcher and renamed Queue - manual merge --- clang-tools-extra/clangd/XRefs.cpp | 11 +++++------ clang-tools-extra/clangd/unittests/XRefsTests.cpp | 15 ++++++++++----- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp index 69f5dbc954692..d4398a593d48e 100644 --- a/clang-tools-extra/clangd/XRefs.cpp +++ b/clang-tools-extra/clangd/XRefs.cpp @@ -307,16 +307,15 @@ std::vector<LocatedSymbol> findImplementors(llvm::DenseSet<SymbolID> IDs, RelationsRequest Req; Req.Predicate = Predicate; llvm::DenseSet<SymbolID> SeenIDs; - llvm::DenseSet<SymbolID> RecursiveSearch = std::move(IDs); + llvm::DenseSet<SymbolID> Queue = std::move(IDs); std::vector<LocatedSymbol> Results; - - while (!RecursiveSearch.empty()) { - Req.Subjects = std::move(RecursiveSearch); - RecursiveSearch = {}; + while (!Queue.empty()) { + Req.Subjects = std::move(Queue); + Queue = {}; Index->relations(Req, [&](const SymbolID &Subject, const Symbol &Object) { if (!SeenIDs.insert(Object.ID).second) return; - RecursiveSearch.insert(Object.ID); + Queue.insert(Object.ID); auto DeclLoc = indexToLSPLocation(Object.CanonicalDeclaration, MainFilePath); if (!DeclLoc) { diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 2f52169214f7b..1b7b46c0d71b1 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -54,6 +54,11 @@ MATCHER(declRange, "") { const Range &Range = ::testing::get<1>(arg); return Sym.PreferredDeclaration.range == Range; } +MATCHER(defRange, "") { + const LocatedSymbol &Sym = ::testing::get<0>(arg); + const Range &Range = ::testing::get<1>(arg); + return Sym.Definition.value_or(Sym.PreferredDeclaration).range == Range; +} // Extracts ranges from an annotated example, and constructs a matcher for a // highlight set. Ranges should be named $read/$write as appropriate. @@ -1927,10 +1932,10 @@ TEST(FindImplementations, InheritanceRecursion) { // Make sure inheritance is followed, but does not diverge. llvm::StringRef Test = R"cpp( template <int> - struct [[Ev^en]]; + struct Ev^en; template <int> - struct [[Odd]]; + struct Odd; template <> struct Even<0> { @@ -1943,10 +1948,10 @@ TEST(FindImplementations, InheritanceRecursion) { }; template <int I> - struct Even : Odd<I - 1> {}; + struct [[Even]] : Odd<I - 1> {}; template <int I> - struct Odd : Even<I - 1> {}; + struct [[Odd]] : Even<I - 1> {}; constexpr bool Answer = Even<42>::value; )cpp"; @@ -1956,7 +1961,7 @@ TEST(FindImplementations, InheritanceRecursion) { auto AST = TU.build(); auto Index = TU.index(); EXPECT_THAT(findImplementations(AST, Code.point(), Index.get()), - UnorderedPointwise(declRange(), Code.ranges())); + UnorderedPointwise(defRange(), Code.ranges())); } TEST(FindImplementations, InheritanceObjC) { >From 3f37408884aac1f4fbf643c24fe8d0bc122467f3 Mon Sep 17 00:00:00 2001 From: Timon Ulrich <[email protected]> Date: Wed, 28 Jan 2026 18:06:45 +0100 Subject: [PATCH 9/9] Fixed InheritanceRecursion test for newly found instantiations --- clang-tools-extra/clangd/unittests/XRefsTests.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 1b7b46c0d71b1..07434d26479c2 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -1948,12 +1948,12 @@ TEST(FindImplementations, InheritanceRecursion) { }; template <int I> - struct [[Even]] : Odd<I - 1> {}; + struct [[[[Even]]]] : Odd<I - 1> {}; template <int I> struct [[Odd]] : Even<I - 1> {}; - constexpr bool Answer = Even<42>::value; + constexpr bool Answer = Even<2>::value; )cpp"; Annotations Code(Test); _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
