llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> We established an instantiation scope in order for constraint equivalence checking to properly map the uninstantiated parameters. That mechanism mapped even packs to themselves. Consequently, parameter packs e.g. appearing in a function call, were not expanded. So they would end up becoming `SubstTemplateTypeParmPackType`s that circularly depend on the canonical declaration of the function template, which is not yet determined, hence the spurious error. No release note as I plan to backport it to 19. Fixes https://github.com/llvm/llvm-project/issues/101735 --- Full diff: https://github.com/llvm/llvm-project/pull/102131.diff 2 Files Affected: - (modified) clang/lib/Sema/SemaConcept.cpp (+9-2) - (modified) clang/test/SemaTemplate/concepts-out-of-line-def.cpp (+23) ``````````diff diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index d4c9d044985e34..14a67f35a8f9f8 100644 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -972,8 +972,15 @@ static const Expr *SubstituteConstraintExpressionWithoutSatisfaction( // equivalence. LocalInstantiationScope ScopeForParameters(S); if (auto *FD = DeclInfo.getDecl()->getAsFunction()) - for (auto *PVD : FD->parameters()) - ScopeForParameters.InstantiatedLocal(PVD, PVD); + for (auto *PVD : FD->parameters()) { + if (!PVD->isParameterPack()) { + ScopeForParameters.InstantiatedLocal(PVD, PVD); + continue; + } + // Parameter packs should expand to a size-of-1 argument. + ScopeForParameters.MakeInstantiatedLocalArgPack(PVD); + ScopeForParameters.InstantiatedLocalPackArg(PVD, PVD); + } std::optional<Sema::CXXThisScopeRAII> ThisScope; diff --git a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp index 0142efcdc3ee86..333187b0d74ad6 100644 --- a/clang/test/SemaTemplate/concepts-out-of-line-def.cpp +++ b/clang/test/SemaTemplate/concepts-out-of-line-def.cpp @@ -599,3 +599,26 @@ template <class DerT> unsigned long DerivedCollection<DerTs...>::index() {} } // namespace GH72557 + +namespace GH101735 { + +template <class, class> +concept True = true; + +template <typename T> +class A { + template <typename... Ts> + void method(Ts&... ts) + requires requires (T t) { + { t.method(static_cast<Ts &&>(ts)...) } -> True<void>; + }; +}; + +template <typename T> +template <typename... Ts> +void A<T>::method(Ts&... ts) + requires requires (T t) { + { t.method(static_cast<Ts &&>(ts)...) } -> True<void>; + } {} + +} `````````` </details> https://github.com/llvm/llvm-project/pull/102131 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
