https://github.com/zyn0217 updated https://github.com/llvm/llvm-project/pull/89019
>From 89a5bbcc89c1e43ac7f2e60f3c234c2c42928c86 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Wed, 17 Apr 2024 12:24:56 +0800 Subject: [PATCH 1/7] [clang] Distinguish unresolved templates in UnresolvedLookupExpr This patch revolves around the misuse of UnresolvedLookupExpr in BuildTemplateIdExpr. Basically, we build up an UnresolvedLookupExpr not only for function overloads but for "unresolved" templates wherever we need an expression for template decls. For example, a dependent VarTemplateDecl can be wrapped with such an expression before template instantiation. (See https://github.com/llvm/llvm-project/commit/617007240cbfb97c8ccf6d61b0c4ca0bb62d43c9) Also, one important thing is that UnresolvedLookupExpr uses a "canonical" QualType to describe the containing unresolved decls: a DependentTy is for dependent expressions and an OverloadTy otherwise. Therefore, this modeling for non-dependent templates leaves a problem in that the expression is marked and perceived as if describing overload functions. The consumer then expects functions for every such expression, although the fact is the reverse. Hence, we run into crashes. As to the patch, I added a new canonical type "UnresolvedTemplateTy" to model these cases. Given that we have been using this model (intentionally or accidentally) and it is pretty baked in throughout the code, I think extending the role of UnresolvedLookupExpr is reasonable. Further, I added some diagnostics for the direct occurrence of these expressions, which are supposed to be ill-formed. As a bonus, this patch also fixes some typos in the diagnostics and creates RecoveryExprs rather than nothing in the hope of a better error-recovery for clangd. Fixes https://github.com/llvm/llvm-project/issues/88832 Fixes https://github.com/llvm/llvm-project/issues/63243 Fixes https://github.com/llvm/llvm-project/issues/48673 --- clang/docs/ReleaseNotes.rst | 1 + clang/include/clang/AST/ASTContext.h | 3 +- clang/include/clang/AST/BuiltinTypes.def | 3 + .../include/clang/Serialization/ASTBitCodes.h | 5 +- clang/lib/AST/ASTContext.cpp | 3 + clang/lib/AST/NSAPI.cpp | 1 + clang/lib/AST/Type.cpp | 3 + clang/lib/AST/TypeLoc.cpp | 1 + clang/lib/Sema/SemaExpr.cpp | 19 +++++ clang/lib/Sema/SemaTemplate.cpp | 13 +++- clang/lib/Serialization/ASTCommon.cpp | 3 + clang/lib/Serialization/ASTReader.cpp | 3 + clang/test/SemaCXX/PR62533.cpp | 2 +- clang/test/SemaTemplate/template-id-expr.cpp | 71 +++++++++++++++++++ 14 files changed, 125 insertions(+), 6 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index efc32212f300cf..8c50988083faa6 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -535,6 +535,7 @@ Bug Fixes to C++ Support - Fix a crash when deducing ``auto`` from an invalid dereference (#GH88329). - Fix a crash in requires expression with templated base class member function. Fixes (#GH84020). - Placement new initializes typedef array with correct size (#GH41441) +- Fixed a misuse of ``UnresolvedLookupExpr`` for ill-formed templated expressions. Fixes (#GH48673), (#GH63243) and (#GH88832). Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h index 28f8d67811f0a2..e9a22f04cfe764 100644 --- a/clang/include/clang/AST/ASTContext.h +++ b/clang/include/clang/AST/ASTContext.h @@ -1116,7 +1116,8 @@ class ASTContext : public RefCountedBase<ASTContext> { CanQualType BFloat16Ty; CanQualType Float16Ty; // C11 extension ISO/IEC TS 18661-3 CanQualType VoidPtrTy, NullPtrTy; - CanQualType DependentTy, OverloadTy, BoundMemberTy, UnknownAnyTy; + CanQualType DependentTy, OverloadTy, BoundMemberTy, UnresolvedTemplateTy, + UnknownAnyTy; CanQualType BuiltinFnTy; CanQualType PseudoObjectTy, ARCUnbridgedCastTy; CanQualType ObjCBuiltinIdTy, ObjCBuiltinClassTy, ObjCBuiltinSelTy; diff --git a/clang/include/clang/AST/BuiltinTypes.def b/clang/include/clang/AST/BuiltinTypes.def index c04f6f6f127191..fd0cc10be8ebca 100644 --- a/clang/include/clang/AST/BuiltinTypes.def +++ b/clang/include/clang/AST/BuiltinTypes.def @@ -285,6 +285,9 @@ PLACEHOLDER_TYPE(Overload, OverloadTy) // x->foo # if only contains non-static members PLACEHOLDER_TYPE(BoundMember, BoundMemberTy) +// The type of an unresolved template. Used in UnresolvedLookupExpr. +PLACEHOLDER_TYPE(UnresolvedTemplate, UnresolvedTemplateTy) + // The type of an expression which refers to a pseudo-object, // such as those introduced by Objective C's @property or // VS.NET's __property declarations. A placeholder type. The diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h index 500098dd3dab1d..2f0a122fdfde14 100644 --- a/clang/include/clang/Serialization/ASTBitCodes.h +++ b/clang/include/clang/Serialization/ASTBitCodes.h @@ -1099,6 +1099,9 @@ enum PredefinedTypeIDs { // \brief WebAssembly reference types with auto numeration #define WASM_TYPE(Name, Id, SingletonId) PREDEF_TYPE_##Id##_ID, #include "clang/Basic/WebAssemblyReferenceTypes.def" + + /// The placeholder type for unresolved templates. + PREDEF_TYPE_UNRESOLVED_TEMPLATE, // Sentinel value. Considered a predefined type but not useable as one. PREDEF_TYPE_LAST_ID }; @@ -1108,7 +1111,7 @@ enum PredefinedTypeIDs { /// /// Type IDs for non-predefined types will start at /// NUM_PREDEF_TYPE_IDs. -const unsigned NUM_PREDEF_TYPE_IDS = 502; +const unsigned NUM_PREDEF_TYPE_IDS = 503; // Ensure we do not overrun the predefined types we reserved // in the enum PredefinedTypeIDs above. diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp index 6ce233704a5885..e9fba116cff559 100644 --- a/clang/lib/AST/ASTContext.cpp +++ b/clang/lib/AST/ASTContext.cpp @@ -1306,6 +1306,9 @@ void ASTContext::InitBuiltinTypes(const TargetInfo &Target, // Placeholder type for bound members. InitBuiltinType(BoundMemberTy, BuiltinType::BoundMember); + // Placeholder type for unresolved templates. + InitBuiltinType(UnresolvedTemplateTy, BuiltinType::UnresolvedTemplate); + // Placeholder type for pseudo-objects. InitBuiltinType(PseudoObjectTy, BuiltinType::PseudoObject); diff --git a/clang/lib/AST/NSAPI.cpp b/clang/lib/AST/NSAPI.cpp index ecc56c13fb7573..4e09b27b0f76cd 100644 --- a/clang/lib/AST/NSAPI.cpp +++ b/clang/lib/AST/NSAPI.cpp @@ -454,6 +454,7 @@ NSAPI::getNSNumberFactoryMethodKind(QualType T) const { #define WASM_TYPE(Name, Id, SingletonId) case BuiltinType::Id: #include "clang/Basic/WebAssemblyReferenceTypes.def" case BuiltinType::BoundMember: + case BuiltinType::UnresolvedTemplate: case BuiltinType::Dependent: case BuiltinType::Overload: case BuiltinType::UnknownAny: diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp index cb22c91a12aa89..4751d73184262f 100644 --- a/clang/lib/AST/Type.cpp +++ b/clang/lib/AST/Type.cpp @@ -3381,6 +3381,8 @@ StringRef BuiltinType::getName(const PrintingPolicy &Policy) const { return "<overloaded function type>"; case BoundMember: return "<bound member function type>"; + case UnresolvedTemplate: + return "<unresolved template type>"; case PseudoObject: return "<pseudo-object type>"; case Dependent: @@ -4673,6 +4675,7 @@ bool Type::canHaveNullability(bool ResultIfUnknown) const { #include "clang/AST/BuiltinTypes.def" return false; + case BuiltinType::UnresolvedTemplate: // Dependent types that could instantiate to a pointer type. case BuiltinType::Dependent: case BuiltinType::Overload: diff --git a/clang/lib/AST/TypeLoc.cpp b/clang/lib/AST/TypeLoc.cpp index 21e152f6aea8a0..e8cd7fd7b35b6f 100644 --- a/clang/lib/AST/TypeLoc.cpp +++ b/clang/lib/AST/TypeLoc.cpp @@ -399,6 +399,7 @@ TypeSpecifierType BuiltinTypeLoc::getWrittenTypeSpec() const { case BuiltinType::NullPtr: case BuiltinType::Overload: case BuiltinType::Dependent: + case BuiltinType::UnresolvedTemplate: case BuiltinType::BoundMember: case BuiltinType::UnknownAny: case BuiltinType::ARCUnbridgedCast: diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 7c3faba0f78819..8fe3e2c771f1bf 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -6349,6 +6349,7 @@ static bool isPlaceholderToRemoveAsArg(QualType type) { #include "clang/AST/BuiltinTypes.def" return false; + case BuiltinType::UnresolvedTemplate: // We cannot lower out overload sets; they might validly be resolved // by the call machinery. case BuiltinType::Overload: @@ -21234,6 +21235,24 @@ ExprResult Sema::CheckPlaceholderExpr(Expr *E) { if (!placeholderType) return E; switch (placeholderType->getKind()) { + case BuiltinType::UnresolvedTemplate: { + auto *ULE = cast<UnresolvedLookupExpr>(E); + const DeclarationNameInfo &NameInfo = ULE->getNameInfo(); + NestedNameSpecifierLoc Loc = ULE->getQualifierLoc(); + NamedDecl *Temp = *ULE->decls_begin(); + bool IsTypeAliasTemplateDecl = isa<TypeAliasTemplateDecl>(Temp); + if (NestedNameSpecifier *NNS = Loc.getNestedNameSpecifier()) + Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_type_template) + << NNS << NameInfo.getName().getAsString() << Loc.getSourceRange() + << IsTypeAliasTemplateDecl; + else + Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_type_template) + << "" << NameInfo.getName().getAsString() << Loc.getSourceRange() + << IsTypeAliasTemplateDecl; + Diag(Temp->getLocation(), diag::note_referenced_type_template) + << IsTypeAliasTemplateDecl; + return CreateRecoveryExpr(NameInfo.getBeginLoc(), NameInfo.getEndLoc(), {}); + } // Overloaded expressions. case BuiltinType::Overload: { diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 95171359f0ab17..14768ca66ac1c5 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5553,7 +5553,7 @@ ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, R.getRepresentativeDecl(), TemplateKWLoc, TemplateArgs); if (Res.isInvalid() || Res.isUsable()) return Res; - // Result is dependent. Carry on to build an UnresolvedLookupEpxr. + // Result is dependent. Carry on to build an UnresolvedLookupExpr. KnownDependent = true; } @@ -5571,6 +5571,12 @@ ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, TemplateKWLoc, R.getLookupNameInfo(), RequiresADL, TemplateArgs, R.begin(), R.end(), KnownDependent); + // Model the templates with UnresolvedTemplateTy. The expression should then + // either be transformed in an instantiation or diagnosed. + if (ULE->getType() == Context.OverloadTy && R.isSingleResult() && + !R.getFoundDecl()->getAsFunction()) + ULE->setType(Context.UnresolvedTemplateTy); + return ULE; } @@ -5609,8 +5615,9 @@ Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_type_template) << SS.getScopeRep() << NameInfo.getName().getAsString() << SS.getRange() << isTypeAliasTemplateDecl; - Diag(Temp->getLocation(), diag::note_referenced_type_template) << 0; - return ExprError(); + Diag(Temp->getLocation(), diag::note_referenced_type_template) + << isTypeAliasTemplateDecl; + return CreateRecoveryExpr(NameInfo.getBeginLoc(), NameInfo.getEndLoc(), {}); }; if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp index f8d54c0c398906..cd2d40a2c65fcb 100644 --- a/clang/lib/Serialization/ASTCommon.cpp +++ b/clang/lib/Serialization/ASTCommon.cpp @@ -186,6 +186,9 @@ serialization::TypeIdxFromBuiltin(const BuiltinType *BT) { case BuiltinType::Overload: ID = PREDEF_TYPE_OVERLOAD_ID; break; + case BuiltinType::UnresolvedTemplate: + ID = PREDEF_TYPE_UNRESOLVED_TEMPLATE; + break; case BuiltinType::BoundMember: ID = PREDEF_TYPE_BOUND_MEMBER; break; diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp index b28df03b4a95e9..445c042330194b 100644 --- a/clang/lib/Serialization/ASTReader.cpp +++ b/clang/lib/Serialization/ASTReader.cpp @@ -7311,6 +7311,9 @@ QualType ASTReader::GetType(TypeID ID) { case PREDEF_TYPE_OVERLOAD_ID: T = Context.OverloadTy; break; + case PREDEF_TYPE_UNRESOLVED_TEMPLATE: + T = Context.UnresolvedTemplateTy; + break; case PREDEF_TYPE_BOUND_MEMBER: T = Context.BoundMemberTy; break; diff --git a/clang/test/SemaCXX/PR62533.cpp b/clang/test/SemaCXX/PR62533.cpp index 920ea54d4b00ed..0753156813f8e7 100644 --- a/clang/test/SemaCXX/PR62533.cpp +++ b/clang/test/SemaCXX/PR62533.cpp @@ -2,7 +2,7 @@ template<typename T> struct test { - template<typename> using fun_diff = char; // expected-note 2{{class template declared here}} + template<typename> using fun_diff = char; // expected-note 2{{type alias template declared here}} }; template<typename T, typename V> diff --git a/clang/test/SemaTemplate/template-id-expr.cpp b/clang/test/SemaTemplate/template-id-expr.cpp index 0555d8b94504fb..741742d9e5d7eb 100644 --- a/clang/test/SemaTemplate/template-id-expr.cpp +++ b/clang/test/SemaTemplate/template-id-expr.cpp @@ -186,3 +186,74 @@ class E { #endif template<typename T> using D = int; // expected-note {{declared here}} E<D> ed; // expected-note {{instantiation of}} + +namespace non_functions { + +#if __cplusplus >= 201103L +namespace PR88832 { +template <typename T> struct O { + static const T v = 0; +}; + +struct P { + template <typename T> using I = typename O<T>::v; // #TypeAlias +}; + +struct Q { + template <typename T> int foo() { + return T::template I<int>; // expected-error {{'P::I' is expected to be a non-type template, but instantiated to a type alias template}} + // expected-note@#TypeAlias {{type alias template declared here}} + } +}; + +int bar() { + return Q().foo<P>(); // expected-note-re {{function template specialization {{.*}} requested here}} +} + +} // namespace PR88832 +#endif + +namespace PR63243 { + +namespace std { +template <class T> struct add_pointer { // #add_pointer +}; +} // namespace std + +class A {}; + +int main() { + std::__add_pointer<A>::type ptr; // #ill-formed-decl + // expected-error@#ill-formed-decl {{no template named '__add_pointer'}} + // expected-note@#add_pointer {{'add_pointer' declared here}} + // expected-error@#ill-formed-decl {{expected ';' after expression}} + // expected-error@#ill-formed-decl {{no type named 'type' in the global namespace}} + // expected-error@#ill-formed-decl {{'std::add_pointer' is expected to be a non-type template, but instantiated to a class template}} + // expected-note@#add_pointer {{class template declared here}} + + // expected-warning@#ill-formed-decl {{keyword '__add_pointer' will be made available as an identifier here}} +} + +} // namespace PR63243 + +namespace PR48673 { + +template <typename T> struct C { + template <int TT> class Type {}; // #ClassTemplate +}; + +template <typename T1> struct A { + void foo() { + C<T1>::template Type<2>; // #templated-decl-as-expression + // expected-error@#templated-decl-as-expression {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}}} + // expected-note@#ClassTemplate {{class template declared here}} + } +}; + +void test() { + A<float>().foo(); // expected-note-re {{instantiation of member function {{.*}} requested here}} +} + +} // namespace PR48673 + +} >From 4b19539f1e530486e0743305595e21ac0d908655 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Thu, 18 Apr 2024 13:17:57 +0800 Subject: [PATCH 2/7] Add tests for function arguments as well as a typo fix --- clang/include/clang/AST/NestedNameSpecifier.h | 2 +- clang/lib/Sema/SemaExpr.cpp | 15 +++++++++------ clang/test/SemaTemplate/template-id-expr.cpp | 19 +++++++++++++++++++ 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/clang/include/clang/AST/NestedNameSpecifier.h b/clang/include/clang/AST/NestedNameSpecifier.h index 7b0c21b9e7cfb1..a1d9e30e660d14 100644 --- a/clang/include/clang/AST/NestedNameSpecifier.h +++ b/clang/include/clang/AST/NestedNameSpecifier.h @@ -266,7 +266,7 @@ class NestedNameSpecifierLoc { explicit operator bool() const { return Qualifier; } /// Evaluates true when this nested-name-specifier location is - /// empty. + /// non-empty. bool hasQualifier() const { return Qualifier; } /// Retrieve the nested-name-specifier to which this instance diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 8fe3e2c771f1bf..2d2c05c86d2410 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -21238,19 +21238,22 @@ ExprResult Sema::CheckPlaceholderExpr(Expr *E) { case BuiltinType::UnresolvedTemplate: { auto *ULE = cast<UnresolvedLookupExpr>(E); const DeclarationNameInfo &NameInfo = ULE->getNameInfo(); - NestedNameSpecifierLoc Loc = ULE->getQualifierLoc(); + // There's only one FoundDecl for UnresolvedTemplate type. See + // BuildTemplateIdExpr. NamedDecl *Temp = *ULE->decls_begin(); - bool IsTypeAliasTemplateDecl = isa<TypeAliasTemplateDecl>(Temp); - if (NestedNameSpecifier *NNS = Loc.getNestedNameSpecifier()) + const bool IsTypeAliasTemplateDecl = isa<TypeAliasTemplateDecl>(Temp); + + if (NestedNameSpecifierLoc Loc = ULE->getQualifierLoc(); Loc.hasQualifier()) Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_type_template) - << NNS << NameInfo.getName().getAsString() << Loc.getSourceRange() - << IsTypeAliasTemplateDecl; + << Loc.getNestedNameSpecifier() << NameInfo.getName().getAsString() + << Loc.getSourceRange() << IsTypeAliasTemplateDecl; else Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_type_template) - << "" << NameInfo.getName().getAsString() << Loc.getSourceRange() + << "" << NameInfo.getName().getAsString() << ULE->getSourceRange() << IsTypeAliasTemplateDecl; Diag(Temp->getLocation(), diag::note_referenced_type_template) << IsTypeAliasTemplateDecl; + return CreateRecoveryExpr(NameInfo.getBeginLoc(), NameInfo.getEndLoc(), {}); } diff --git a/clang/test/SemaTemplate/template-id-expr.cpp b/clang/test/SemaTemplate/template-id-expr.cpp index 741742d9e5d7eb..5109e9158256be 100644 --- a/clang/test/SemaTemplate/template-id-expr.cpp +++ b/clang/test/SemaTemplate/template-id-expr.cpp @@ -243,10 +243,29 @@ template <typename T> struct C { }; template <typename T1> struct A { + + template <int TT> class SubA {}; // #SubA + + template <typename T2> + void foo(T2) {} + void foo() { C<T1>::template Type<2>; // #templated-decl-as-expression // expected-error@#templated-decl-as-expression {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}}} // expected-note@#ClassTemplate {{class template declared here}} + + foo(C<T1>::Type<2>); // expected-error {{expected expression}} + + foo(C<T1>::template Type<2>); + // expected-error@-1 {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}} + // expected-note@#ClassTemplate {{class template declared here}} + + foo(C<T1>::template Type<2>()); + // expected-error@-1 {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}} + // expected-error@-2 {{called object type '<dependent type>' is not a function or function pointer}} + // expected-note@#ClassTemplate {{class template declared here}} + + foo(typename C<T1>::template Type<2>()); } }; >From 1b371b88f87edf034f90e28468c89387187e0a2d Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Thu, 18 Apr 2024 13:23:57 +0800 Subject: [PATCH 3/7] cleanup --- clang/test/SemaTemplate/template-id-expr.cpp | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/clang/test/SemaTemplate/template-id-expr.cpp b/clang/test/SemaTemplate/template-id-expr.cpp index 5109e9158256be..d4f6c641000f57 100644 --- a/clang/test/SemaTemplate/template-id-expr.cpp +++ b/clang/test/SemaTemplate/template-id-expr.cpp @@ -201,7 +201,8 @@ struct P { struct Q { template <typename T> int foo() { - return T::template I<int>; // expected-error {{'P::I' is expected to be a non-type template, but instantiated to a type alias template}} + return T::template I<int>; + // expected-error@-1 {{'P::I' is expected to be a non-type template, but instantiated to a type alias template}} // expected-note@#TypeAlias {{type alias template declared here}} } }; @@ -244,8 +245,6 @@ template <typename T> struct C { template <typename T1> struct A { - template <int TT> class SubA {}; // #SubA - template <typename T2> void foo(T2) {} >From 2496f49f49a93ced1601b1add185c6e9e55b18d0 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Mon, 22 Apr 2024 23:04:35 +0800 Subject: [PATCH 4/7] Handle TRANSFORM_TYPE_TRAIT_DEFs in ParseOptionalCXXScopeSpecifier ... so that these "keywords" can be parsed as ordinary identifiers in a specifier. --- clang/lib/Parse/ParseExprCXX.cpp | 14 ++++++++++++++ clang/lib/Sema/SemaTemplate.cpp | 3 ++- clang/test/SemaTemplate/template-id-expr.cpp | 16 ++++++++-------- 3 files changed, 24 insertions(+), 9 deletions(-) diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp index 43d6105dcf31c4..c583f6b39063be 100644 --- a/clang/lib/Parse/ParseExprCXX.cpp +++ b/clang/lib/Parse/ParseExprCXX.cpp @@ -407,6 +407,20 @@ bool Parser::ParseOptionalCXXScopeSpecifier( continue; } + switch (Tok.getKind()) { +#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case tok::kw___##Trait: +#include "clang/Basic/TransformTypeTraits.def" + if (!NextToken().is(tok::l_paren)) { + Tok.setKind(tok::identifier); + Diag(Tok, diag::ext_keyword_as_ident) + << Tok.getIdentifierInfo()->getName() << 0; + continue; + } + [[fallthrough]]; + default: + break; + } + // The rest of the nested-name-specifier possibilities start with // tok::identifier. if (Tok.isNot(tok::identifier)) diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 14768ca66ac1c5..30237dc4e3096a 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5572,7 +5572,8 @@ ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, R.begin(), R.end(), KnownDependent); // Model the templates with UnresolvedTemplateTy. The expression should then - // either be transformed in an instantiation or diagnosed. + // either be transformed in an instantiation or be diagnosed in + // CheckPlaceholderExpr. if (ULE->getType() == Context.OverloadTy && R.isSingleResult() && !R.getFoundDecl()->getAsFunction()) ULE->setType(Context.UnresolvedTemplateTy); diff --git a/clang/test/SemaTemplate/template-id-expr.cpp b/clang/test/SemaTemplate/template-id-expr.cpp index d4f6c641000f57..8338a0e2162ec1 100644 --- a/clang/test/SemaTemplate/template-id-expr.cpp +++ b/clang/test/SemaTemplate/template-id-expr.cpp @@ -224,15 +224,15 @@ template <class T> struct add_pointer { // #add_pointer class A {}; int main() { - std::__add_pointer<A>::type ptr; // #ill-formed-decl - // expected-error@#ill-formed-decl {{no template named '__add_pointer'}} + std::__add_pointer<A>::type ptr; + // expected-warning@-1 {{keyword '__add_pointer' will be made available as an identifier here}} + // expected-error@-2 {{no template named '__add_pointer'}} // expected-note@#add_pointer {{'add_pointer' declared here}} - // expected-error@#ill-formed-decl {{expected ';' after expression}} - // expected-error@#ill-formed-decl {{no type named 'type' in the global namespace}} - // expected-error@#ill-formed-decl {{'std::add_pointer' is expected to be a non-type template, but instantiated to a class template}} - // expected-note@#add_pointer {{class template declared here}} - - // expected-warning@#ill-formed-decl {{keyword '__add_pointer' will be made available as an identifier here}} + // expected-error-re@-4 {{no type named 'type' in '{{.*}}std::add_pointer<{{.*}}A>'}} + __add_pointer<A>::type ptr2; + // expected-error@-1 {{no template named '__add_pointer'}} + // expected-error-re@-2 {{no type named 'type' in '{{.*}}std::add_pointer<{{.*}}A>'}} + // expected-note@#add_pointer {{'std::add_pointer' declared here}} } } // namespace PR63243 >From 1c7c2049305f5b033128d7dc7ade4e96ebe24413 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Mon, 22 Apr 2024 23:31:17 +0800 Subject: [PATCH 5/7] cleanup --- clang/test/SemaTemplate/template-id-expr.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/clang/test/SemaTemplate/template-id-expr.cpp b/clang/test/SemaTemplate/template-id-expr.cpp index 8338a0e2162ec1..ce40aade9cf174 100644 --- a/clang/test/SemaTemplate/template-id-expr.cpp +++ b/clang/test/SemaTemplate/template-id-expr.cpp @@ -229,6 +229,7 @@ int main() { // expected-error@-2 {{no template named '__add_pointer'}} // expected-note@#add_pointer {{'add_pointer' declared here}} // expected-error-re@-4 {{no type named 'type' in '{{.*}}std::add_pointer<{{.*}}A>'}} + __add_pointer<A>::type ptr2; // expected-error@-1 {{no template named '__add_pointer'}} // expected-error-re@-2 {{no type named 'type' in '{{.*}}std::add_pointer<{{.*}}A>'}} @@ -249,8 +250,8 @@ template <typename T1> struct A { void foo(T2) {} void foo() { - C<T1>::template Type<2>; // #templated-decl-as-expression - // expected-error@#templated-decl-as-expression {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}}} + C<T1>::template Type<2>; + // expected-error@-1 {{'C<float>::Type' is expected to be a non-type template, but instantiated to a class template}}} // expected-note@#ClassTemplate {{class template declared here}} foo(C<T1>::Type<2>); // expected-error {{expected expression}} >From 8c54ccc6f542655108c839d65a29c109eff74633 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Fri, 3 May 2024 22:50:27 +0800 Subject: [PATCH 6/7] Add comments to UnresolvedLookupExpr --- clang/include/clang/AST/ExprCXX.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h index d28e5c3a78ee4b..6142373c46b805 100644 --- a/clang/include/clang/AST/ExprCXX.h +++ b/clang/include/clang/AST/ExprCXX.h @@ -3161,8 +3161,28 @@ class OverloadExpr : public Expr { /// This arises in several ways: /// * we might be waiting for argument-dependent lookup; /// * the name might resolve to an overloaded function; +/// * the name might resolve to a non-function template; for example, in the +/// following snippet, the return expression of the member function +/// 'foo()' might remain unresolved until instantiation: +/// +/// struct P { +/// template <class T> using I = T; +/// }; +/// +/// struct Q { +/// template <class T> int foo() { +/// return T::template I<int>; +/// } +/// }; +/// +/// ...which is distinct from modeling function overloads, and therefore we use +/// a different builtin type 'UnresolvedTemplate' to avoid confusion. This is +/// done in Sema::BuildTemplateIdExpr. +/// /// and eventually: /// * the lookup might have included a function template. +/// * the unresolved template gets transformed in an instantiation or gets +/// diagnosed for its direct use. /// /// These never include UnresolvedUsingValueDecls, which are always class /// members and therefore appear only in UnresolvedMemberLookupExprs. >From ae8cd3ca239d561cfd702762f9afb52aead79e99 Mon Sep 17 00:00:00 2001 From: Younan Zhang <zyn7...@gmail.com> Date: Fri, 3 May 2024 23:03:25 +0800 Subject: [PATCH 7/7] Use '\code' ... '\endcode' block --- clang/include/clang/AST/ExprCXX.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h index 6142373c46b805..ea727dc3f96e48 100644 --- a/clang/include/clang/AST/ExprCXX.h +++ b/clang/include/clang/AST/ExprCXX.h @@ -3165,6 +3165,7 @@ class OverloadExpr : public Expr { /// following snippet, the return expression of the member function /// 'foo()' might remain unresolved until instantiation: /// +/// \code /// struct P { /// template <class T> using I = T; /// }; @@ -3174,6 +3175,7 @@ class OverloadExpr : public Expr { /// return T::template I<int>; /// } /// }; +/// \endcode /// /// ...which is distinct from modeling function overloads, and therefore we use /// a different builtin type 'UnresolvedTemplate' to avoid confusion. This is _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
