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/107055.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+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 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 { `````````` </details> https://github.com/llvm/llvm-project/pull/107055 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
