[clang] [Clang][Sema] Diagnose use of template keyword after declarative nested-name-specifiers (PR #78595)
Krystian Stasiowski via cfe-commits
cfe-commits at lists.llvm.org
Fri Jan 19 07:25:28 PST 2024
https://github.com/sdkrystian updated https://github.com/llvm/llvm-project/pull/78595
>From c07119d8e85e4bd9849e8d0b5dc8edb5384d9b91 Mon Sep 17 00:00:00 2001
From: Krystian Stasiowski <sdkrystian at gmail.com>
Date: Wed, 17 Jan 2024 10:13:29 -0500
Subject: [PATCH] [Clang][Sema] Diagnose use of template keyword after
declarative nested-name-specifiers
---
clang/include/clang/AST/TypeLoc.h | 2 +-
.../clang/Basic/DiagnosticSemaKinds.td | 2 +
clang/include/clang/Sema/Sema.h | 3 +-
clang/lib/Sema/SemaDecl.cpp | 59 ++++++++++--
clang/lib/Sema/SemaDeclCXX.cpp | 14 ++-
clang/lib/Sema/SemaTemplate.cpp | 17 +++-
clang/lib/Sema/TreeTransform.h | 10 +-
clang/test/CXX/drs/dr23xx.cpp | 4 +-
clang/test/CXX/drs/dr7xx.cpp | 6 +-
.../temp.class/temp.mem.func/p1.cpp | 18 ++--
clang/test/CXX/temp/temp.names/p5.cpp | 94 +++++++++++++++++++
clang/test/CXX/temp/temp.spec/part.spec.cpp | 2 +-
clang/test/SemaCXX/static-assert.cpp | 2 +-
.../test/SemaTemplate/class-template-spec.cpp | 8 +-
14 files changed, 201 insertions(+), 40 deletions(-)
create mode 100644 clang/test/CXX/temp/temp.names/p5.cpp
diff --git a/clang/include/clang/AST/TypeLoc.h b/clang/include/clang/AST/TypeLoc.h
index 471deb14aba51f..4b95e2d0a7da41 100644
--- a/clang/include/clang/AST/TypeLoc.h
+++ b/clang/include/clang/AST/TypeLoc.h
@@ -1684,7 +1684,7 @@ class TemplateSpecializationTypeLoc :
}
void initializeLocal(ASTContext &Context, SourceLocation Loc) {
- setTemplateKeywordLoc(Loc);
+ setTemplateKeywordLoc(SourceLocation());
setTemplateNameLoc(Loc);
setLAngleLoc(Loc);
setRAngleLoc(Loc);
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 03b0122d1c08f7..a5aedd45452e44 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8223,6 +8223,8 @@ def err_invalid_declarator_in_block : Error<
"definition or redeclaration of %0 not allowed inside a block">;
def err_not_tag_in_scope : Error<
"no %select{struct|interface|union|class|enum}0 named %1 in %2">;
+def ext_template_after_declarative_nns : ExtWarn<
+ "'template' cannot be used after a declarative nested name specifier">;
def err_no_typeid_with_fno_rtti : Error<
"use of typeid requires -frtti">;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 0db39333b0ee34..c2f2e9ba1d304b 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -2915,7 +2915,8 @@ class Sema final {
bool DiagnoseClassNameShadow(DeclContext *DC, DeclarationNameInfo Info);
bool diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
DeclarationName Name, SourceLocation Loc,
- bool IsTemplateId);
+ TemplateIdAnnotation *TemplateId,
+ bool IsMemberSpecialization);
void
diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
SourceLocation FallbackLoc,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index cbb8ed8ce34d1b..f8d12ca0b1c7c8 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6264,13 +6264,17 @@ bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
///
/// \param Loc The location of the name of the entity being declared.
///
-/// \param IsTemplateId Whether the name is a (simple-)template-id, and thus
-/// we're declaring an explicit / partial specialization / instantiation.
+/// \param IsMemberSpecialization Whether we are declaring a member
+/// specialization.
+///
+/// \param TemplateId The template-id, if any.
///
/// \returns true if we cannot safely recover from this error, false otherwise.
bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
DeclarationName Name,
- SourceLocation Loc, bool IsTemplateId) {
+ SourceLocation Loc,
+ TemplateIdAnnotation *TemplateId,
+ bool IsMemberSpecialization) {
DeclContext *Cur = CurContext;
while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
Cur = Cur->getParent();
@@ -6299,7 +6303,7 @@ bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
// Check whether the qualifying scope encloses the scope of the original
// declaration. For a template-id, we perform the checks in
// CheckTemplateSpecializationScope.
- if (!Cur->Encloses(DC) && !IsTemplateId) {
+ if (!Cur->Encloses(DC) && !(TemplateId || IsMemberSpecialization)) {
if (Cur->isRecord())
Diag(Loc, diag::err_member_qualification)
<< Name << SS.getRange();
@@ -6345,12 +6349,42 @@ bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
return false;
}
+ // C++23 [temp.names]p5:
+ // The keyword template shall not appear immediately after a declarative
+ // nested-name-specifier.
+ if (TemplateId && TemplateId->TemplateKWLoc.isValid()) {
+ Diag(Loc, diag::ext_template_after_declarative_nns)
+ << FixItHint::CreateRemoval(TemplateId->TemplateKWLoc);
+ }
+
+ NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
+ while (SpecLoc.getPrefix()) {
+ // C++23 [temp.names]p5:
+ // The keyword template shall not appear immediately after a declarative
+ // nested-name-specifier.
+ // FIXME: nested-name-specifiers in friend declarations are declarative,
+ // but we don't call diagnoseQualifiedDeclaration for them. We should.
+ if (SpecLoc.getNestedNameSpecifier()->getKind() ==
+ NestedNameSpecifier::TypeSpecWithTemplate) {
+ SourceLocation TemplateKWLoc;
+ auto TL = SpecLoc.getTypeLoc();
+ if (const auto DTSTL =
+ TL.getAsAdjusted<DependentTemplateSpecializationTypeLoc>())
+ TemplateKWLoc = DTSTL.getTemplateKeywordLoc();
+ else if (const auto TSTL =
+ TL.getAsAdjusted<TemplateSpecializationTypeLoc>())
+ TemplateKWLoc = TSTL.getTemplateKeywordLoc();
+ else
+ TemplateKWLoc = TL.getBeginLoc();
+
+ Diag(Loc, diag::ext_template_after_declarative_nns)
+ << FixItHint::CreateRemoval(TemplateKWLoc);
+ }
+ SpecLoc = SpecLoc.getPrefix();
+ }
// C++11 [dcl.meaning]p1:
// [...] "The nested-name-specifier of the qualified declarator-id shall
// not begin with a decltype-specifer"
- NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
- while (SpecLoc.getPrefix())
- SpecLoc = SpecLoc.getPrefix();
if (isa_and_nonnull<DecltypeType>(
SpecLoc.getNestedNameSpecifier()->getAsType()))
Diag(Loc, diag::err_decltype_in_declarator)
@@ -6412,9 +6446,13 @@ NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
return nullptr;
}
if (!D.getDeclSpec().isFriendSpecified()) {
- if (diagnoseQualifiedDeclaration(
- D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(),
- D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) {
+ TemplateIdAnnotation *TemplateId =
+ D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
+ ? D.getName().TemplateId
+ : nullptr;
+ if (diagnoseQualifiedDeclaration(D.getCXXScopeSpec(), DC, Name,
+ D.getIdentifierLoc(), TemplateId,
+ /*IsMemberSpecialization=*/false)) {
if (DC->isRecord())
return nullptr;
@@ -17965,6 +18003,7 @@ Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
// nested-name-specifier against the current context.
if ((TUK == TUK_Definition || TUK == TUK_Declaration) &&
diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc,
+ /*TemplateId=*/nullptr,
isMemberSpecialization))
Invalid = true;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 828a0ec3dd042b..48c622c5fc1121 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -3621,14 +3621,18 @@ Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
// class X {
// int X::member;
// };
- if (DeclContext *DC = computeDeclContext(SS, false))
+ if (DeclContext *DC = computeDeclContext(SS, false)) {
+ TemplateIdAnnotation *TemplateId =
+ D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
+ ? D.getName().TemplateId
+ : nullptr;
diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
- D.getName().getKind() ==
- UnqualifiedIdKind::IK_TemplateId);
- else
+ TemplateId,
+ /*IsMemberSpecialization=*/false);
+ } else {
Diag(D.getIdentifierLoc(), diag::err_member_qualification)
<< Name << SS.getRange();
-
+ }
SS.clear();
}
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 0655d363352067..bbe1459f891ae6 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -1890,8 +1890,12 @@ DeclResult Sema::CheckClassTemplate(
ContextRAII SavedContext(*this, SemanticContext);
if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
Invalid = true;
- } else if (TUK != TUK_Friend && TUK != TUK_Reference)
- diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc, false);
+ }
+
+ if (TUK != TUK_Friend && TUK != TUK_Reference)
+ diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc,
+ /*TemplateId-*/ nullptr,
+ /*IsMemberSpecialization*/ false);
LookupQualifiedName(Previous, SemanticContext);
} else {
@@ -8771,6 +8775,15 @@ DeclResult Sema::ActOnClassTemplateSpecialization(
bool isMemberSpecialization = false;
bool isPartialSpecialization = false;
+ if (SS.isSet()) {
+ if (TUK != TUK_Reference && TUK != TUK_Friend &&
+ diagnoseQualifiedDeclaration(SS, ClassTemplate->getDeclContext(),
+ ClassTemplate->getDeclName(),
+ TemplateNameLoc, &TemplateId,
+ /*IsMemberSpecialization=*/false))
+ return true;
+ }
+
// Check the validity of the template headers that introduce this
// template.
// FIXME: We probably shouldn't complain about these headers for
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 4463904b07211b..74dd828f4c3568 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -4376,8 +4376,14 @@ NestedNameSpecifierLoc TreeTransform<Derived>::TransformNestedNameSpecifierLoc(
SS.Adopt(ETL.getQualifierLoc());
TL = ETL.getNamedTypeLoc();
}
- SS.Extend(SemaRef.Context, /*FIXME:*/ SourceLocation(), TL,
- Q.getLocalEndLoc());
+ SourceLocation TemplateKWLoc;
+ if (const auto TSTL = TL.getAs<TemplateSpecializationTypeLoc>())
+ TemplateKWLoc = TSTL.getTemplateKeywordLoc();
+ else if (const auto DTSTL =
+ TL.getAs<DependentTemplateSpecializationTypeLoc>())
+ TemplateKWLoc = DTSTL.getTemplateKeywordLoc();
+
+ SS.Extend(SemaRef.Context, TemplateKWLoc, TL, Q.getLocalEndLoc());
break;
}
// If the nested-name-specifier is an invalid type def, don't emit an
diff --git a/clang/test/CXX/drs/dr23xx.cpp b/clang/test/CXX/drs/dr23xx.cpp
index 03077ae9239a45..a14fb58e38af0b 100644
--- a/clang/test/CXX/drs/dr23xx.cpp
+++ b/clang/test/CXX/drs/dr23xx.cpp
@@ -182,8 +182,8 @@ struct Bad2 { int a, b; };
} // namespace dr2386
namespace std {
template <typename T> struct tuple_size;
-template <> struct std::tuple_size<dr2386::Bad1> {};
-template <> struct std::tuple_size<dr2386::Bad2> {
+template <> struct tuple_size<dr2386::Bad1> {};
+template <> struct tuple_size<dr2386::Bad2> {
static const int value = 42;
};
} // namespace std
diff --git a/clang/test/CXX/drs/dr7xx.cpp b/clang/test/CXX/drs/dr7xx.cpp
index 926bff1cc479c5..2cbdc218ab7b5b 100644
--- a/clang/test/CXX/drs/dr7xx.cpp
+++ b/clang/test/CXX/drs/dr7xx.cpp
@@ -105,7 +105,8 @@ namespace dr727 { // dr727: partial
// expected-note@#dr727-N {{explicitly specialized declaration is here}}
template<> struct A::C<double>;
- // expected-error at -1 {{class template specialization of 'C' not in class 'A' or an enclosing namespace}}
+ // expected-error at -1 {{non-friend class member 'C' cannot have a qualified name}}
+ // expected-error at -2 {{class template specialization of 'C' not in class 'A' or an enclosing namespace}}
// expected-note@#dr727-C {{explicitly specialized declaration is here}}
template<> void A::f<double>();
// expected-error at -1 {{o function template matches function template specialization 'f'}}
@@ -116,7 +117,8 @@ namespace dr727 { // dr727: partial
// expected-note@#dr727-N {{explicitly specialized declaration is here}}
template<typename T> struct A::C<T***>;
- // expected-error at -1 {{class template partial specialization of 'C' not in class 'A' or an enclosing namespace}}
+ // expected-error at -1 {{non-friend class member 'C' cannot have a qualified name}}
+ // expected-error at -2 {{class template partial specialization of 'C' not in class 'A' or an enclosing namespace}}
// expected-note@#dr727-C {{explicitly specialized declaration is here}}
template<typename T> static int A::N<T***>;
// expected-error at -1 {{non-friend class member 'N' cannot have a qualified name}}
diff --git a/clang/test/CXX/temp/temp.decls/temp.class/temp.mem.func/p1.cpp b/clang/test/CXX/temp/temp.decls/temp.class/temp.mem.func/p1.cpp
index 17645639fb82f3..7618aacc2c5f05 100644
--- a/clang/test/CXX/temp/temp.decls/temp.class/temp.mem.func/p1.cpp
+++ b/clang/test/CXX/temp/temp.decls/temp.class/temp.mem.func/p1.cpp
@@ -3,21 +3,21 @@ template<typename T, typename U> // expected-note{{previous template}}
class X0 {
public:
typedef int size_type;
-
+
X0(int);
~X0();
-
+
void f0(const T&, const U&);
-
+
T& operator[](int i) const;
-
+
void f1(size_type) const;
void f2(size_type) const;
void f3(size_type) const;
void f4() ;
-
+
operator T*() const;
-
+
T value;
};
@@ -41,7 +41,7 @@ template<class X, class Y, class Z> // expected-error{{too many template paramet
void X0<X, Y>::f3(size_type) const {
}
-template<class X, class Y>
+template<class X, class Y>
void X0<Y, X>::f4() { } // expected-error{{does not refer}}
// FIXME: error message should probably say, "redefinition of 'X0<T, U>::f0'"
@@ -68,14 +68,14 @@ namespace N { template <class X> void A<X>::a() {} }
// PR5566
template<typename T>
-struct X1 {
+struct X1 {
template<typename U>
struct B { void f(); };
};
template<typename T>
template<typename U>
-void X1<T>::template B<U>::f() { }
+void X1<T>::template B<U>::f() { } // expected-error{{'template' cannot be used after a declarative nested name specifier}}
// PR5527
template <template <class> class T>
diff --git a/clang/test/CXX/temp/temp.names/p5.cpp b/clang/test/CXX/temp/temp.names/p5.cpp
new file mode 100644
index 00000000000000..2581277f448da0
--- /dev/null
+++ b/clang/test/CXX/temp/temp.names/p5.cpp
@@ -0,0 +1,94 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+template<typename T> struct A {
+ template<typename U> struct B {
+ struct C;
+ template<typename V> struct D;
+ template<typename V> struct D<V*>;
+
+ void f();
+ template<typename V> void g();
+
+ static int x;
+ template<typename V> static int y;
+ template<typename V> static int y<V*>;
+
+ enum class E;
+ };
+};
+
+template<typename T>
+template<typename U>
+struct A<T>::template B<U>::C { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+struct A<int>::template B<bool>::C; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+struct A<int>::template B<bool>::C { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+template<typename V>
+struct A<T>::template B<U>::D { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+template<typename V>
+struct A<T>::template B<U>::D<V*> { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+template<typename V>
+struct A<int>::template B<bool>::D { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+template<typename V>
+struct A<int>::template B<bool>::D<V*> { }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+void A<T>::template B<U>::f() { } // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+void A<int>::template B<bool>::f() { } // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+template<typename V>
+void A<T>::template B<U>::g() { } // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+template<typename V>
+void A<int>::template B<bool>::g() { } // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+int A<T>::template B<U>::x = 0; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+template<typename V>
+int A<T>::template B<U>::y = 0; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+template<typename V>
+int A<T>::template B<U>::y<V*> = 0; // expected-error{{'template' cannot be used after a declarative}}
+
+template<typename T>
+template<typename U>
+enum class A<T>::template B<U>::E { a }; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+enum class A<int>::template B<bool>::E; // expected-error{{'template' cannot be used after a declarative}}
+
+template<>
+template<>
+enum class A<int>::template B<bool>::E { a }; // expected-error{{'template' cannot be used after a declarative}}
diff --git a/clang/test/CXX/temp/temp.spec/part.spec.cpp b/clang/test/CXX/temp/temp.spec/part.spec.cpp
index f62050af69cff5..4b0fdb902633a1 100644
--- a/clang/test/CXX/temp/temp.spec/part.spec.cpp
+++ b/clang/test/CXX/temp/temp.spec/part.spec.cpp
@@ -478,4 +478,4 @@ template <typename T> class PCTT6<TestClass::PrivateClass, T> {
};
template <typename T1> template <typename, typename> class PCTT6<TestClass::PrivateClass, T1>::NCT4 final {};
// expected-error at +1 2{{is a private member of}}
-template <typename T1> template <typename T2> struct PCTT6<TestClass::PrivateClass, T1>::template NCT3<T2, TestClass::TemplatePrivateClass<TestClass::TemplateProtectedClass<TestClass::PublicClass>>> : PCTT6<TestClass::PrivateClass, T1>::NCT4<T2, TestClass::TemplatePrivateClass<int>> {};
+template <typename T1> template <typename T2> struct PCTT6<TestClass::PrivateClass, T1>::NCT3<T2, TestClass::TemplatePrivateClass<TestClass::TemplateProtectedClass<TestClass::PublicClass>>> : PCTT6<TestClass::PrivateClass, T1>::NCT4<T2, TestClass::TemplatePrivateClass<int>> {};
diff --git a/clang/test/SemaCXX/static-assert.cpp b/clang/test/SemaCXX/static-assert.cpp
index 6e1701602ae30c..0d384b6b499f78 100644
--- a/clang/test/SemaCXX/static-assert.cpp
+++ b/clang/test/SemaCXX/static-assert.cpp
@@ -197,7 +197,7 @@ struct NestedTemplates1 {
template <typename T, typename U, int a>
void foo2() {
static_assert(::ns::NestedTemplates1<T, a>::NestedTemplates2::template NestedTemplates3<U>::value, "message");
- // expected-error at -1{{static assertion failed due to requirement '::ns::NestedTemplates1<int, 3>::NestedTemplates2::NestedTemplates3<float>::value': message}}
+ // expected-error at -1{{static assertion failed due to requirement '::ns::NestedTemplates1<int, 3>::NestedTemplates2::template NestedTemplates3<float>::value': message}}
}
template void foo2<int, float, 3>();
// expected-note at -1{{in instantiation of function template specialization 'foo2<int, float, 3>' requested here}}
diff --git a/clang/test/SemaTemplate/class-template-spec.cpp b/clang/test/SemaTemplate/class-template-spec.cpp
index e96ef44b7a251b..56b8207bd9a435 100644
--- a/clang/test/SemaTemplate/class-template-spec.cpp
+++ b/clang/test/SemaTemplate/class-template-spec.cpp
@@ -74,14 +74,14 @@ namespace N {
// Diagnose specialization errors
struct A<double> { }; // expected-error{{template specialization requires 'template<>'}}
-template<> struct ::A<double>;
+template<> struct ::A<double>; // expected-warning {{extra qualification on member}}
namespace N {
template<typename T> struct B; // expected-note {{explicitly specialized}}
- template<> struct ::N::B<char>; // okay
- template<> struct ::N::B<short>; // okay
- template<> struct ::N::B<int>; // okay
+ template<> struct ::N::B<char>; // expected-warning {{extra qualification on member}}
+ template<> struct ::N::B<short>; // expected-warning {{extra qualification on member}}
+ template<> struct ::N::B<int>; // expected-warning {{extra qualification on member}}
int f(int);
}
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