llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> In consteval calls rewriting, we expect an instantiated AST to remain untouched. However, this was not true when rebuilding a MemberExpr in TreeTransform, as it relies on FoundDecl to build a resolved member call expression. This is due to the fact that the instantiated CXXMemberCallExpr still holds a template declaration as FoundDecl, leading to a non-dependent-to-dependent transform. I don't think it makes much sense to preserve a template in FoundDecl. FoundDecl should primarily distinguish declarations whose getUnderlyingDecl() points elsewhere, like UsingShadowDecl. Fixes https://github.com/llvm/llvm-project/issues/137885 --- Full diff: https://github.com/llvm/llvm-project/pull/138377.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaOverload.cpp (+7-1) - (modified) clang/test/SemaCXX/cxx2a-consteval.cpp (+28) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 5ccd346a93b4f..5e26a3052452b 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -545,6 +545,7 @@ Bug Fixes to C++ Support - Clang no longer crashes when establishing subsumption between some constraint expressions. (#GH122581) - Clang now issues an error when placement new is used to modify a const-qualified variable in a ``constexpr`` function. (#GH131432) +- Fixed an incorrect TreeTransform for calls to ``consteval`` functions if a conversion template is present. (#GH137885) - Clang now emits a warning when class template argument deduction for alias templates is used in C++17. (#GH133806) Bug Fixes to AST Handling diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index 5b224b6c08fef..05707b964bc27 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -3977,7 +3977,7 @@ IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, // phase of [over.match.list] when the initializer list has exactly // one element that is itself an initializer list, [...] and the // conversion is to X or reference to cv X, user-defined conversion - // sequences are not cnosidered. + // sequences are not considered. if (SuppressUserConversions && ListInitializing) { SuppressUserConversions = NumArgs == 1 && isa<InitListExpr>(Args[0]) && @@ -14750,6 +14750,12 @@ ExprResult Sema::CreateUnresolvedLookupExpr(CXXRecordDecl *NamingClass, ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, CXXConversionDecl *Method, bool HadMultipleCandidates) { + // FoundDecl can be the TemplateDecl of Method. Don't retain a template in + // the FoundDecl as it impedes TransformMemberExpr. + // We go a bit further here: if there's no difference in UnderlyingDecl, + // then using FoundDecl vs Method shouldn't make a difference either. + if (FoundDecl->getUnderlyingDecl() == FoundDecl) + FoundDecl = Method; // Convert the expression to match the conversion function's implicit object // parameter. ExprResult Exp; diff --git a/clang/test/SemaCXX/cxx2a-consteval.cpp b/clang/test/SemaCXX/cxx2a-consteval.cpp index fef4674d17841..d9d144cafdbcc 100644 --- a/clang/test/SemaCXX/cxx2a-consteval.cpp +++ b/clang/test/SemaCXX/cxx2a-consteval.cpp @@ -1272,3 +1272,31 @@ int main() { } } // namespace GH107175 + +namespace GH137885 { + +template <typename... P> struct A {}; + +template <int N> +struct B { + consteval B() {} + + template <typename... P> consteval operator A<P...>() const { + static_assert(sizeof...(P) == N); + return {}; + } +}; + +template <typename T> struct type_identity { + using type = T; +}; + +template <typename... P> +void foo(typename type_identity<A<P...>>::type a, P...) {} + +void foo() { + foo(B<0>()); + foo(B<5>(), 1, 2, 3, 4, 5); +} + +} `````````` </details> https://github.com/llvm/llvm-project/pull/138377 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
