https://github.com/zyn0217 created https://github.com/llvm/llvm-project/pull/122875
We should have been checking desugar() for the type of the right-hand side of a typedef declaration, instead of using getCanonicalType(), which points to the end of the type alias chain. Fixes https://github.com/llvm/llvm-project/issues/122417 >From bda66af1a35a120ad017fcfa310d68e977629ce2 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Tue, 14 Jan 2025 16:49:41 +0800 Subject: [PATCH] [Clang] Correctly propagate type aliases' unexpanded flags up to lambda We should have been checking desugar() for the type of the right-hand side of a typedef declaration, instead of using getCanonicalType(), which points to the end of the type alias chain. --- clang/docs/ReleaseNotes.rst | 2 +- clang/lib/Sema/TreeTransform.h | 2 +- clang/test/SemaCXX/fold_lambda_with_variadics.cpp | 6 ++++++ 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 07a1a4195427d8..a5da6c9c88328c 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -810,7 +810,7 @@ Bug Fixes to C++ Support module imports in those situations. (#GH60336) - Fix init-capture packs having a size of one before being instantiated. (#GH63677) - Clang now preserves the unexpanded flag in a lambda transform used for pack expansion. (#GH56852), (#GH85667), - (#GH99877). + (#GH99877), (#GH122417). - Fixed a bug when diagnosing ambiguous explicit specializations of constrained member functions. - Fixed an assertion failure when selecting a function from an overload set that includes a specialization of a conversion function template. diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 4a3c739ecbeab8..79df5cf4f2bb56 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -8496,7 +8496,7 @@ TreeTransform<Derived>::TransformDeclStmt(DeclStmt *S) { getSema() .getASTContext() .getTypeDeclType(TD) - .getCanonicalType() + .getSingleStepDesugaredType(getSema().getASTContext()) ->containsUnexpandedParameterPack(); if (auto *VD = dyn_cast<VarDecl>(Transformed)) diff --git a/clang/test/SemaCXX/fold_lambda_with_variadics.cpp b/clang/test/SemaCXX/fold_lambda_with_variadics.cpp index 2257a4c2d975a8..69572bea3664a7 100644 --- a/clang/test/SemaCXX/fold_lambda_with_variadics.cpp +++ b/clang/test/SemaCXX/fold_lambda_with_variadics.cpp @@ -7,6 +7,8 @@ struct identity { using type = T; }; +template <class> using ElementType = int; + template <class = void> void f() { static_assert([]<class... Is>(Is... x) { @@ -47,6 +49,10 @@ template <class = void> void f() { }(), ...); }(1, 2); + []<class... Is>(Is...) { + ([] { using T = ElementType<Is>; }(), ...); + }(1); + [](auto ...y) { ([y] { }(), ...); }(); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
