https://github.com/sdkrystian updated https://github.com/llvm/llvm-project/pull/80864
>From b28a6a478d021a15a6004c4f3f243ce26f6d86d8 Mon Sep 17 00:00:00 2001 From: Krystian Stasiowski <sdkryst...@gmail.com> Date: Tue, 6 Feb 2024 11:08:04 -0500 Subject: [PATCH 1/2] [Clang][Sema] Abbreviated function templates do not append invented parameters to empty template parameter lists --- clang/docs/ReleaseNotes.rst | 2 ++ clang/lib/Sema/SemaDecl.cpp | 2 +- clang/lib/Sema/SemaDeclCXX.cpp | 11 ++++++++- .../CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp | 24 +++++++++++++++++++ 4 files changed, 37 insertions(+), 2 deletions(-) create mode 100644 clang/test/CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 52a48c750fe55b..8202dc0c20341d 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -210,6 +210,8 @@ Bug Fixes to C++ Support Fixes (`#68490 <https://github.com/llvm/llvm-project/issues/68490>`_) - Fix a crash when trying to call a varargs function that also has an explicit object parameter. Fixes (`#80971 ICE when explicit object parameter be a function parameter pack`) +- Fixed a bug where abbreviated function templates would append their invented template parameters to + an empty template parameter lists. Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 18a5d93ab8e8c6..018d518588b942 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -9759,7 +9759,7 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC, SmallVector<TemplateParameterList *, 4> TemplateParamLists; llvm::append_range(TemplateParamLists, TemplateParamListsRef); if (TemplateParameterList *Invented = D.getInventedTemplateParameterList()) { - if (!TemplateParamLists.empty() && + if (!TemplateParamLists.empty() && TemplateParamLists.back()->size() && Invented->getDepth() == TemplateParamLists.back()->getDepth()) TemplateParamLists.back() = Invented; else diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index ab8a967b06a456..f34893d88a3b3f 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -19294,7 +19294,16 @@ void Sema::ActOnStartFunctionDeclarationDeclarator( ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid, /*SuppressDiagnostic=*/true); } - if (ExplicitParams) { + // C++23 [dcl.fct]p23: + // An abbreviated function template can have a template-head. The invented + // template-parameters are appended to the template-parameter-list after + // the explicitly declared template-parameters. + // + // A template-head must have one or more template-parameters (read: + // 'template<>' is *not* a template-head). Only append the invented + // template parameters if we matched the nested-name-specifier to a non-empty + // TemplateParameterList. + if (ExplicitParams && ExplicitParams->size()) { Info.AutoTemplateParameterDepth = ExplicitParams->getDepth(); llvm::append_range(Info.TemplateParams, *ExplicitParams); Info.NumExplicitTemplateParams = ExplicitParams->size(); diff --git a/clang/test/CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp new file mode 100644 index 00000000000000..469c4e091953c3 --- /dev/null +++ b/clang/test/CXX/dcl.decl/dcl.meaning/dcl.fct/p23.cpp @@ -0,0 +1,24 @@ +// RUN: %clang_cc1 -std=c++20 -pedantic-errors -verify %s + +// FIXME: This should be an error with -pedantic-errors. +template<> // expected-warning {{extraneous template parameter list in template specialization}} +void f(auto); + +template<typename> +void f(auto); + +template<typename T> +struct A { + void g(auto); +}; + +template<typename T> +void A<T>::g(auto) { } + +template<> +void A<int>::g(auto) { } + +// FIXME: This should be an error with -pedantic-errors. +template<> +template<> // expected-warning {{extraneous template parameter list in template specialization}} +void A<long>::g(auto) { } >From 181fc8bbd6d0c9618ec5d005ba35a8492b07ff2a Mon Sep 17 00:00:00 2001 From: Krystian Stasiowski <sdkryst...@gmail.com> Date: Tue, 6 Feb 2024 11:32:41 -0500 Subject: [PATCH 2/2] [FOLD] --- clang/include/clang/AST/DeclTemplate.h | 1 + clang/lib/AST/DeclPrinter.cpp | 4 ++++ clang/lib/Sema/SemaDecl.cpp | 2 +- clang/lib/Sema/SemaDeclCXX.cpp | 2 +- 4 files changed, 7 insertions(+), 2 deletions(-) diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h index baf71145d99dc6..e3b6a7efb1127a 100644 --- a/clang/include/clang/AST/DeclTemplate.h +++ b/clang/include/clang/AST/DeclTemplate.h @@ -134,6 +134,7 @@ class TemplateParameterList final const_iterator end() const { return begin() + NumParams; } unsigned size() const { return NumParams; } + bool empty() const { return NumParams == 0; } ArrayRef<NamedDecl *> asArray() { return llvm::ArrayRef(begin(), end()); } ArrayRef<const NamedDecl*> asArray() const { diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp index 822ac12c4c7dd4..43d221968ea3fb 100644 --- a/clang/lib/AST/DeclPrinter.cpp +++ b/clang/lib/AST/DeclPrinter.cpp @@ -1215,6 +1215,10 @@ void DeclPrinter::printTemplateParameters(const TemplateParameterList *Params, bool OmitTemplateKW) { assert(Params); + // Don't print invented template parameter lists. + if (!Params->empty() && Params->getParam(0)->isImplicit()) + return; + if (!OmitTemplateKW) Out << "template "; Out << '<'; diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 018d518588b942..2c526cd0d0e675 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -9759,7 +9759,7 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC, SmallVector<TemplateParameterList *, 4> TemplateParamLists; llvm::append_range(TemplateParamLists, TemplateParamListsRef); if (TemplateParameterList *Invented = D.getInventedTemplateParameterList()) { - if (!TemplateParamLists.empty() && TemplateParamLists.back()->size() && + if (!TemplateParamLists.empty() && !TemplateParamLists.back()->empty() && Invented->getDepth() == TemplateParamLists.back()->getDepth()) TemplateParamLists.back() = Invented; else diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index f34893d88a3b3f..fea8c5036c80b1 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -19303,7 +19303,7 @@ void Sema::ActOnStartFunctionDeclarationDeclarator( // 'template<>' is *not* a template-head). Only append the invented // template parameters if we matched the nested-name-specifier to a non-empty // TemplateParameterList. - if (ExplicitParams && ExplicitParams->size()) { + if (ExplicitParams && !ExplicitParams->empty()) { Info.AutoTemplateParameterDepth = ExplicitParams->getDepth(); llvm::append_range(Info.TemplateParams, *ExplicitParams); Info.NumExplicitTemplateParams = ExplicitParams->size(); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits