https://github.com/cor3ntin updated https://github.com/llvm/llvm-project/pull/107055
>From 18c11cbf5a3768f03234df2ec2bdd79d5e971f55 Mon Sep 17 00:00:00 2001 From: Corentin Jabot <corentinja...@gmail.com> Date: Tue, 3 Sep 2024 09:52:55 +0200 Subject: [PATCH 1/2] [Clang] Fix handling of placeholder variables name in init captures We were incorrectly not deduplicating results when looking up `_` which, for a lambda init capture, would result in an ambiguous lookup. The same bug caused some diagnostic notes to be emitted twice. Fixes #107024 --- clang/docs/ReleaseNotes.rst | 1 + clang/lib/Sema/SemaLookup.cpp | 2 +- clang/test/SemaCXX/cxx2c-placeholder-vars.cpp | 6 ++++-- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index fc940db4813948..af4388eada8e5a 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -339,6 +339,7 @@ Bug Fixes to C++ Support - Template parameter names are considered in the name lookup of out-of-line class template specialization right before its declaration context. (#GH64082) - Fixed a constraint comparison bug for friend declarations. (#GH78101) +- Fix handling of ``_`` as the name of a lambda's init capture variable. (#GH107024) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp index 7a6a64529f52ec..d3d4bf27ae7283 100644 --- a/clang/lib/Sema/SemaLookup.cpp +++ b/clang/lib/Sema/SemaLookup.cpp @@ -570,7 +570,7 @@ void LookupResult::resolveKind() { // For non-type declarations, check for a prior lookup result naming this // canonical declaration. - if (!D->isPlaceholderVar(getSema().getLangOpts()) && !ExistingI) { + if (!ExistingI) { auto UniqueResult = Unique.insert(std::make_pair(D, I)); if (!UniqueResult.second) { // We've seen this entity before. diff --git a/clang/test/SemaCXX/cxx2c-placeholder-vars.cpp b/clang/test/SemaCXX/cxx2c-placeholder-vars.cpp index 5cf66b48784e91..29ca3b5ef3df72 100644 --- a/clang/test/SemaCXX/cxx2c-placeholder-vars.cpp +++ b/clang/test/SemaCXX/cxx2c-placeholder-vars.cpp @@ -50,14 +50,16 @@ void f() { void lambda() { (void)[_ = 0, _ = 1] { // expected-warning {{placeholder variables are incompatible with C++ standards before C++2c}} \ - // expected-note 4{{placeholder declared here}} + // expected-note 2{{placeholder declared here}} (void)_++; // expected-error {{ambiguous reference to placeholder '_', which is defined multiple times}} }; { int _ = 12; - (void)[_ = 0]{}; // no warning (different scope) + (void)[_ = 0]{ return _;}; // no warning (different scope) } + + auto GH107024 = [_ = 42]() { return _; }(); } namespace global_var { >From bf6e12d50b78cb3abd5e4e5e4a5709ff98069803 Mon Sep 17 00:00:00 2001 From: Corentin Jabot <corentinja...@gmail.com> Date: Tue, 3 Sep 2024 11:56:42 +0200 Subject: [PATCH 2/2] Remove duplicated PushOnScopeChains --- clang/lib/Sema/SemaLambda.cpp | 1 - 1 file changed, 1 deletion(-) diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp index a8461a7f6cf712..15ed8572e60844 100644 --- a/clang/lib/Sema/SemaLambda.cpp +++ b/clang/lib/Sema/SemaLambda.cpp @@ -1323,7 +1323,6 @@ void Sema::ActOnLambdaExpressionAfterIntroducer(LambdaIntroducer &Intro, if (C->Init.isUsable()) { addInitCapture(LSI, cast<VarDecl>(Var), C->Kind == LCK_ByRef); - PushOnScopeChains(Var, CurScope, false); } else { TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef : TryCapture_ExplicitByVal; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits