Author: Yuli Fiterman Date: 2026-06-26T11:26:31+02:00 New Revision: f0bbae6641e6ec88537f26d5bcbd3e17a16bf5e3
URL: https://github.com/llvm/llvm-project/commit/f0bbae6641e6ec88537f26d5bcbd3e17a16bf5e3 DIFF: https://github.com/llvm/llvm-project/commit/f0bbae6641e6ec88537f26d5bcbd3e17a16bf5e3.diff LOG: [clangd] Navigate go-to-definition through forwarding wrappers to the constructor (#199480) When the user invokes **Go to Definition** on a call like `std::make_unique<T>(args...)` or `std::make_shared<T>(args...)`, surface the constructor of `T` that is actually invoked inside the wrapper, alongside the wrapper itself. The constructor is added before the wrapper so LSP clients that auto-jump to the first target land on it; clients that present a menu still let the user reach the wrapper. This is the forward-direction counterpart to the find-references work in #169742 (clangd/clangd#716): the same `isLikelyForwardingFunction` + `searchConstructorsInForwardingFunction` machinery, applied to `locateASTReferent`. Added: Modified: clang-tools-extra/clangd/AST.cpp clang-tools-extra/clangd/AST.h clang-tools-extra/clangd/XRefs.cpp clang-tools-extra/clangd/index/SymbolCollector.cpp clang-tools-extra/clangd/index/SymbolCollector.h clang-tools-extra/clangd/unittests/XRefsTests.cpp Removed: ################################################################################ diff --git a/clang-tools-extra/clangd/AST.cpp b/clang-tools-extra/clangd/AST.cpp index 2ebc9b49cac55..046bec5d0d5e6 100644 --- a/clang-tools-extra/clangd/AST.cpp +++ b/clang-tools-extra/clangd/AST.cpp @@ -1115,5 +1115,21 @@ searchConstructorsInForwardingFunction(const FunctionDecl *FD) { return Result; } +ArrayRef<const CXXConstructorDecl *> +getForwardedConstructors(const FunctionDecl *FD, + ForwardingToConstructorCache &Cache) { + assert(FD && "FD must not be null"); + if (!FD->isTemplateInstantiation()) + return {}; + if (auto It = Cache.find(FD); It != Cache.end()) + return It->getSecond(); + const auto *PT = FD->getPrimaryTemplate(); + if (!PT || !isLikelyForwardingFunction(PT)) + return {}; + auto Inserted = + Cache.try_emplace(FD, searchConstructorsInForwardingFunction(FD)); + return Inserted.first->getSecond(); +} + } // namespace clangd } // namespace clang diff --git a/clang-tools-extra/clangd/AST.h b/clang-tools-extra/clangd/AST.h index 2bb4943b6de0b..ab03b117771d7 100644 --- a/clang-tools-extra/clangd/AST.h +++ b/clang-tools-extra/clangd/AST.h @@ -21,6 +21,9 @@ #include "clang/AST/TypeLoc.h" #include "clang/Basic/SourceLocation.h" #include "clang/Lex/MacroInfo.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringRef.h" #include <optional> #include <string> @@ -261,6 +264,24 @@ bool isLikelyForwardingFunction(const FunctionTemplateDecl *FT); SmallVector<const CXXConstructorDecl *, 1> searchConstructorsInForwardingFunction(const FunctionDecl *FD); +/// Cache mapping forwarding function instantiations (e.g. `make_unique<T>`) +/// to the constructors they ultimately call. +using ForwardingToConstructorCache = + llvm::DenseMap<const FunctionDecl *, + SmallVector<const CXXConstructorDecl *, 1>>; + +/// Returns the constructors that FD forwards to, if FD is a template +/// instantiation of a likely forwarding function (see +/// `isLikelyForwardingFunction`). Results are memoized in `Cache`. Returns +/// an empty range for non-forwarding functions; the cache is only populated +/// for true forwarding instantiations to keep its size bounded. +/// +/// FD must not be null. The returned ArrayRef is owned by `Cache`; consume +/// it before any other call that may insert into the same cache. +ArrayRef<const CXXConstructorDecl *> +getForwardedConstructors(const FunctionDecl *FD, + ForwardingToConstructorCache &Cache); + } // namespace clangd } // namespace clang diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp index ecda4c44a0f38..6886d235811d5 100644 --- a/clang-tools-extra/clangd/XRefs.cpp +++ b/clang-tools-extra/clangd/XRefs.cpp @@ -196,6 +196,22 @@ getDeclAtPosition(ParsedAST &AST, SourceLocation Pos, DeclRelationSet Relations, return Result; } +// Returns the deepest CallExpr whose selection-tree commonAncestor is the call +// itself at `Loc` (i.e. the cursor lands on the call's parens area, not on a +// child like the callee identifier or an argument). Returns null otherwise. +const CallExpr *findEnclosingCallAt(ParsedAST &AST, SourceLocation Loc) { + unsigned Offset = AST.getSourceManager().getDecomposedSpellingLoc(Loc).second; + const CallExpr *Found = nullptr; + SelectionTree::createEach(AST.getASTContext(), AST.getTokens(), Offset, + Offset, [&](SelectionTree ST) { + if (const SelectionTree::Node *N = + ST.commonAncestor()) + Found = N->ASTNode.get<CallExpr>(); + return true; + }); + return Found; +} + // Expects Loc to be a SpellingLocation, will bail out otherwise as it can't // figure out a filename. std::optional<Location> makeLocation(const ASTContext &AST, SourceLocation Loc, @@ -419,6 +435,31 @@ locateASTReferent(SourceLocation CurLoc, const syntax::Token *TouchedIdentifier, AST.getASTContext(), nameLocation(*Def, SM), MainFilePath); }; + // Special case: if the cursor lands directly on a call expression (i.e. + // its enclosing SelectionTree node is the CallExpr itself, not the callee + // identifier or an argument), and the call invokes a forwarding wrapper + // such as `std::make_unique<T>(...)`, navigate to the constructor of `T` + // that the wrapper ultimately calls. This mirrors the existing + // constructor-call behaviour: `Abc^()` jumps to the constructor while + // `A^bc()` jumps to the type. The hook does not fire when the cursor is + // on the wrapper's identifier; that path continues to navigate to the + // wrapper itself via the candidate loop below. + if (const auto *CE = findEnclosingCallAt(AST, CurLoc)) { + if (const auto *Callee = CE->getDirectCallee()) { + llvm::SmallPtrSet<const CXXConstructorDecl *, 1> Seen; + for (const auto *Ctor : + getForwardedConstructors(Callee, AST.ForwardingToConstructorCache)) + if (Seen.insert(Ctor).second) { + LocateASTReferentMetric.record(1, "forwarded-constructor"); + AddResultDecl(Ctor); + } + } + } + if (!Result.empty()) { + enhanceLocatedSymbolsFromIndex(Result, Index, MainFilePath); + return Result; + } + // Emit all symbol locations (declaration or definition) from AST. DeclRelationSet Relations = DeclRelation::TemplatePattern | DeclRelation::Alias; @@ -966,27 +1007,12 @@ class ReferenceFinder : public index::IndexDataConsumer { bool forwardsToConstructor(const Decl *D) { if (TargetConstructors.empty()) return false; - auto *FD = llvm::dyn_cast<clang::FunctionDecl>(D); - if (FD == nullptr || !FD->isTemplateInstantiation()) + const auto *FD = llvm::dyn_cast<clang::FunctionDecl>(D); + if (!FD) return false; - - SmallVector<const CXXConstructorDecl *, 1> *Constructors = nullptr; - if (auto Entry = AST.ForwardingToConstructorCache.find(FD); - Entry != AST.ForwardingToConstructorCache.end()) - Constructors = &Entry->getSecond(); - if (Constructors == nullptr) { - if (auto *PT = FD->getPrimaryTemplate(); - PT == nullptr || !isLikelyForwardingFunction(PT)) - return false; - - SmallVector<const CXXConstructorDecl *, 1> FoundConstructors = - searchConstructorsInForwardingFunction(FD); - auto Iter = AST.ForwardingToConstructorCache.try_emplace( - FD, std::move(FoundConstructors)); - Constructors = &Iter.first->getSecond(); - } - for (auto *Constructor : *Constructors) - if (TargetConstructors.contains(Constructor)) + for (const auto *Ctor : + getForwardedConstructors(FD, AST.ForwardingToConstructorCache)) + if (TargetConstructors.contains(Ctor)) return true; return false; } diff --git a/clang-tools-extra/clangd/index/SymbolCollector.cpp b/clang-tools-extra/clangd/index/SymbolCollector.cpp index b9602b36e2bba..244fb6f687551 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.cpp +++ b/clang-tools-extra/clangd/index/SymbolCollector.cpp @@ -573,23 +573,12 @@ SymbolCollector::getRefContainer(const Decl *Enclosing, return Enclosing; } -SmallVector<const CXXConstructorDecl *, 1> +ArrayRef<const CXXConstructorDecl *> SymbolCollector::findIndirectConstructors(const Decl *D) { - auto *FD = llvm::dyn_cast<clang::FunctionDecl>(D); - if (FD == nullptr || !FD->isTemplateInstantiation()) + const auto *FD = llvm::dyn_cast<clang::FunctionDecl>(D); + if (!FD) return {}; - if (auto Entry = ForwardingToConstructorCache.find(FD); - Entry != ForwardingToConstructorCache.end()) - return Entry->getSecond(); - if (auto *PT = FD->getPrimaryTemplate(); - PT == nullptr || !isLikelyForwardingFunction(PT)) - return {}; - - SmallVector<const CXXConstructorDecl *, 1> FoundConstructors = - searchConstructorsInForwardingFunction(FD); - auto Iter = ForwardingToConstructorCache.try_emplace( - FD, std::move(FoundConstructors)); - return Iter.first->getSecond(); + return getForwardedConstructors(FD, ForwardingToConstructorCache); } // Always return true to continue indexing. diff --git a/clang-tools-extra/clangd/index/SymbolCollector.h b/clang-tools-extra/clangd/index/SymbolCollector.h index 4d51d747639b1..8239aa7020c1e 100644 --- a/clang-tools-extra/clangd/index/SymbolCollector.h +++ b/clang-tools-extra/clangd/index/SymbolCollector.h @@ -161,9 +161,9 @@ class SymbolCollector : public index::IndexDataConsumer { private: // If D is an instantiation of a likely forwarding function, return the // constructors it invokes so that we can record indirect references - // to those as well. - SmallVector<const CXXConstructorDecl *, 1> - findIndirectConstructors(const Decl *D); + // to those as well. The returned ArrayRef is owned by + // `ForwardingToConstructorCache`. + ArrayRef<const CXXConstructorDecl *> findIndirectConstructors(const Decl *D); const Symbol *addDeclaration(const NamedDecl &, SymbolID, bool IsMainFileSymbol); diff --git a/clang-tools-extra/clangd/unittests/XRefsTests.cpp b/clang-tools-extra/clangd/unittests/XRefsTests.cpp index 7f31a1e97d5d7..dce033af73c1a 100644 --- a/clang-tools-extra/clangd/unittests/XRefsTests.cpp +++ b/clang-tools-extra/clangd/unittests/XRefsTests.cpp @@ -2939,6 +2939,79 @@ TEST(FindReferences, TemplatedConstructorForwarding) { rangeIs(Main.range("ForwardedCaller2")))); } +TEST(LocateSymbol, ConstructorForwarding) { + // Caret-on-paren of a forwarding wrapper navigates to the constructor it + // ultimately invokes; caret-on-identifier still navigates to the wrapper. + // This mirrors the existing direct-ctor behaviour (`Abc^()` -> ctor, + // `A^bc()` -> type). + Annotations Code(R"cpp( + namespace std { + template <class T> T &&forward(T &t); + template <class T, class... Args> + T *$MakeUnique[[make_unique]](Args &&...args) { + return new T(std::forward<Args>(args)...); + } + template <class T, class... Args> T *make_unique2(Args &&...args) { + return make_unique<T>(forward<Args>(args)...); + } + template <class T, class... Args> T *make_unique3(Args &&...args) { + return make_unique2<T>(forward<Args>(args)...); + } + template <class T> struct shared_ptr { + shared_ptr(T *) {} + }; + template <class T, class... Args> + shared_ptr<T> make_shared(Args &&...args) { + return shared_ptr<T>(new T(std::forward<Args>(args)...)); + } + } + + // Non-forwarding template: a call to it should fall through to itself. + template <class T> T *$Make[[make]]() { return nullptr; } + + struct Test { + $DefaultCtor[[Test]]() {} + $IntCtor[[Test]](int) {} + Test(const char *) {} + }; + + int main() { + // Caret on parens -> Test default ctor. + auto a = std::make_unique<Test>$ParenMU^(); + // Caret on the wrapper identifier -> make_unique itself. + auto b = std::ma$IdentMU^ke_unique<Test>(); + // make_shared works the same way; overload resolution picks Test(int). + auto c = std::make_shared<Test>$MakeShared^(1); + // Chained forwarding (three wrappers deep). + auto d = std::make_unique3<Test>$Chained^(); + // Overload resolution inside the instantiated body picks Test(int). + auto e = std::make_unique<Test>$Overload^(42); + // Non-forwarding template call: no constructor target. + auto f = make<Test>$NonFwd^(); + } + )cpp"); + TestTU TU = TestTU::withCode(Code.code()); + auto AST = TU.build(); + + EXPECT_THAT(locateSymbolAt(AST, Code.point("ParenMU")), + ElementsAre(sym("Test", Code.range("DefaultCtor"), + Code.range("DefaultCtor")))); + EXPECT_THAT(locateSymbolAt(AST, Code.point("IdentMU")), + ElementsAre(sym("make_unique", Code.range("MakeUnique"), + Code.range("MakeUnique")))); + EXPECT_THAT( + locateSymbolAt(AST, Code.point("MakeShared")), + ElementsAre(sym("Test", Code.range("IntCtor"), Code.range("IntCtor")))); + EXPECT_THAT(locateSymbolAt(AST, Code.point("Chained")), + ElementsAre(sym("Test", Code.range("DefaultCtor"), + Code.range("DefaultCtor")))); + EXPECT_THAT( + locateSymbolAt(AST, Code.point("Overload")), + ElementsAre(sym("Test", Code.range("IntCtor"), Code.range("IntCtor")))); + EXPECT_THAT(locateSymbolAt(AST, Code.point("NonFwd")), + ElementsAre(sym("make", Code.range("Make"), Code.range("Make")))); +} + TEST(GetNonLocalDeclRefs, All) { struct Case { llvm::StringRef AnnotatedCode; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
