llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: cor3ntin (cor3ntin) <details> <summary>Changes</summary> 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 --- Full diff: https://github.com/llvm/llvm-project/pull/107214.diff 4 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+2) - (modified) clang/lib/Sema/SemaLambda.cpp (-1) - (modified) clang/lib/Sema/SemaLookup.cpp (+1-1) - (modified) clang/test/SemaCXX/cxx2c-placeholder-vars.cpp (+4-2) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 5eed9827343dd5..5acc44ed177a7d 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -1121,6 +1121,8 @@ Bug Fixes to C++ Support Fixes (#GH85992). - Fixed a crash-on-invalid bug involving extraneous template parameter with concept substitution. (#GH73885) - Fixed assertion failure by skipping the analysis of an invalid field declaration. (#GH99868) +- 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/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp index 601077e9f3334d..809b94bb7412b9 100644 --- a/clang/lib/Sema/SemaLambda.cpp +++ b/clang/lib/Sema/SemaLambda.cpp @@ -1318,7 +1318,6 @@ 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; 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 { `````````` </details> https://github.com/llvm/llvm-project/pull/107214 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
