https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/112293
Backport 0bc02b999a Requested by: @zyn0217 >From 2717eeb2584005e08bc0b2c1b77954ff156a5bab Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Fri, 11 Oct 2024 10:31:27 +0800 Subject: [PATCH] [Clang] Instantiate Typedefs referenced by type alias deduction guides (#111804) TypedefNameDecl referenced by a synthesized CTAD guide for type aliases was not transformed previously, resulting in a substitution failure in BuildDeductionGuideForTypeAlias() when substituting into the right-hand-side deduction guide. This patch fixes it in the way we have been doing since https://reviews.llvm.org/D80743. We transform all the function parameters, parenting referenced TypedefNameDecls with the CXXDeductionGuideDecl. Then we instantiate these declarations in FindInstantiatedDecl() as we build up the eventual deduction guide, using the mechanism introduced in D80743 Fixes #111508 (cherry picked from commit 0bc02b999a9686ba240b7a68d3f1cbbf037d2170) --- clang/lib/Sema/SemaTemplateDeductionGuide.cpp | 21 ++++++++++++++++--- clang/test/SemaCXX/cxx20-ctad-type-alias.cpp | 13 ++++++++++++ 2 files changed, 31 insertions(+), 3 deletions(-) diff --git a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp index 0602d07c6b9b0d..1bf82b31def977 100644 --- a/clang/lib/Sema/SemaTemplateDeductionGuide.cpp +++ b/clang/lib/Sema/SemaTemplateDeductionGuide.cpp @@ -69,8 +69,8 @@ class ExtractTypeForDeductionGuide ExtractTypeForDeductionGuide( Sema &SemaRef, llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs, - ClassTemplateDecl *NestedPattern, - const MultiLevelTemplateArgumentList *OuterInstantiationArgs) + ClassTemplateDecl *NestedPattern = nullptr, + const MultiLevelTemplateArgumentList *OuterInstantiationArgs = nullptr) : Base(SemaRef), MaterializedTypedefs(MaterializedTypedefs), NestedPattern(NestedPattern), OuterInstantiationArgs(OuterInstantiationArgs) { @@ -1263,10 +1263,25 @@ FunctionTemplateDecl *DeclareAggregateDeductionGuideForTypeAlias( getRHSTemplateDeclAndArgs(SemaRef, AliasTemplate).first; if (!RHSTemplate) return nullptr; + + llvm::SmallVector<TypedefNameDecl *> TypedefDecls; + llvm::SmallVector<QualType> NewParamTypes; + ExtractTypeForDeductionGuide TypeAliasTransformer(SemaRef, TypedefDecls); + for (QualType P : ParamTypes) { + QualType Type = TypeAliasTransformer.TransformType(P); + if (Type.isNull()) + return nullptr; + NewParamTypes.push_back(Type); + } + auto *RHSDeductionGuide = SemaRef.DeclareAggregateDeductionGuideFromInitList( - RHSTemplate, ParamTypes, Loc); + RHSTemplate, NewParamTypes, Loc); if (!RHSDeductionGuide) return nullptr; + + for (TypedefNameDecl *TD : TypedefDecls) + TD->setDeclContext(RHSDeductionGuide->getTemplatedDecl()); + return BuildDeductionGuideForTypeAlias(SemaRef, AliasTemplate, RHSDeductionGuide, Loc); } diff --git a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp index 5392573fcdb9d5..675c32a81f1ae8 100644 --- a/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp +++ b/clang/test/SemaCXX/cxx20-ctad-type-alias.cpp @@ -481,3 +481,16 @@ struct Out { Out<float>::B out(100); // deduced to Out<float>::A<float>; static_assert(__is_same(decltype(out), Out<float>::A<float>)); } + +namespace GH111508 { + +template <typename V> struct S { + using T = V; + T Data; +}; + +template <typename V> using Alias = S<V>; + +Alias A(42); + +} // namespace GH111508 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
