[clang] [Clang] Disallow explicit object parameters in more contexts (PR #89078)
via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 15 09:01:24 PDT 2024
https://github.com/Sirraide updated https://github.com/llvm/llvm-project/pull/89078
>From c611122688657287e8285edd9a2875e4975d26dd Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 17 Apr 2024 16:15:39 +0200
Subject: [PATCH 01/13] [Clang] Disallow explicit object parameters in more
contexts
---
.../clang/Basic/DiagnosticSemaKinds.td | 2 ++
clang/lib/Sema/SemaDeclCXX.cpp | 6 ++--
clang/lib/Sema/SemaType.cpp | 30 +++++++++++++++++++
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 22 ++++++++++++--
4 files changed, 54 insertions(+), 6 deletions(-)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 5ec0218aedfe8..680638d2e59c6 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7494,6 +7494,8 @@ def err_explicit_object_parameter_mutable: Error<
def err_invalid_explicit_object_type_in_lambda: Error<
"invalid explicit object parameter type %0 in lambda with capture; "
"the type must be the same as, or derived from, the lambda">;
+def err_explicit_object_parameter_invalid: Error<
+ "an explicit object parameter is not allowed here">;
def err_ref_qualifier_overload : Error<
"cannot overload a member function %select{without a ref-qualifier|with "
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 7669171fea56f..ea634df48e5de 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11469,10 +11469,8 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D,
return;
if (!DC || !DC->isRecord()) {
- Diag(ExplicitObjectParam->getLocation(),
- diag::err_explicit_object_parameter_nonmember)
- << D.getSourceRange() << /*non-member=*/2 << IsLambda;
- D.setInvalidType();
+ assert(D.isInvalidType() && "Explicit object parameter in non-member "
+ "should have been diagnosed already");
return;
}
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 404c4e8e31b55..406065741bf2d 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5287,6 +5287,36 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// Check for auto functions and trailing return type and adjust the
// return type accordingly.
if (!D.isInvalidType()) {
+ // [dcl.fct]p6:
+ //
+ // An explicit-object-parameter-declaration is a parameter-declaration
+ // with a this specifier. An explicit-object-parameter-declaration shall
+ // appear only as the first parameter-declaration of a
+ // parameter-declaration-list of either:
+ //
+ // - a member-declarator that declares a member function [class.mem], or
+ // - a lambda-declarator [expr.prim.lambda].
+ DeclaratorContext C = D.getContext();
+ ParmVarDecl *First =
+ FTI.NumParams
+ ? dyn_cast_if_present<ParmVarDecl>(FTI.Params[0].Param)
+ : nullptr;
+ if (First && First->isExplicitObjectParameter() &&
+ C != DeclaratorContext::LambdaExpr &&
+
+ // Either not a member or nested declarator in a member.
+ (C != DeclaratorContext::Member ||
+ D.getInnermostNonParenChunk() != &DeclType) &&
+
+ // Allow out-of-line definitions if we have a scope spec.
+ D.getCXXScopeSpec().isEmpty()) {
+ S.Diag(First->getBeginLoc(),
+ diag::err_explicit_object_parameter_invalid)
+ << First->getSourceRange();
+ D.setInvalidType();
+ AreDeclaratorChunksValid = false;
+ }
+
// trailing-return-type is only required if we're declaring a function,
// and not, for instance, a pointer to a function.
if (D.getDeclSpec().hasAutoTypeSpec() &&
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index 5f29a955e053c..ddb770a92db0f 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -5,7 +5,7 @@
void f(this); // expected-error{{variable has incomplete type 'void'}} \
// expected-error{{invalid use of 'this' outside of a non-static member function}}
-void g(this auto); // expected-error{{an explicit object parameter cannot appear in a non-member function}}
+void g(this auto); // expected-error{{an explicit object parameter is not allowed here}}
auto l1 = [] (this auto) static {}; // expected-error{{an explicit object parameter cannot appear in a static lambda}}
auto l2 = [] (this auto) mutable {}; // expected-error{{a lambda with an explicit object parameter cannot be mutable}}
@@ -685,7 +685,7 @@ struct S {
static void j(this S s); // expected-error {{an explicit object parameter cannot appear in a static function}}
};
-void nonmember(this S s); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
+void nonmember(this S s); // expected-error {{an explicit object parameter is not allowed here}}
int test() {
S s;
@@ -838,3 +838,21 @@ int h() {
}();
}
}
+
+namespace GH85992 {
+struct S {
+ int (S::*x)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+ int (*y)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+ int (***z)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+
+ int f(this S);
+ int ((g))(this S);
+ int h(int x, int (*)(this S)); // expected-error {{an explicit object parameter is not allowed here}}
+};
+
+using T = int (*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+using U = int (S::*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+int h(this int); // expected-error {{an explicit object parameter is not allowed here}}
+
+int S::f(this S) { return 1; }
+}
>From c27a3ff93474bc890de2b66ab7f486bb59e3b6d8 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 17 Apr 2024 16:16:47 +0200
Subject: [PATCH 02/13] [NFC] clang-format
---
clang/lib/Sema/SemaType.cpp | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 406065741bf2d..23f2b9d74931b 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5294,7 +5294,8 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// appear only as the first parameter-declaration of a
// parameter-declaration-list of either:
//
- // - a member-declarator that declares a member function [class.mem], or
+ // - a member-declarator that declares a member function [class.mem],
+ // or
// - a lambda-declarator [expr.prim.lambda].
DeclaratorContext C = D.getContext();
ParmVarDecl *First =
>From 0c1239a85159aaa4958bb574a326e85f50719b1b Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 17 Apr 2024 16:23:15 +0200
Subject: [PATCH 03/13] [NFC] Reformat comment
---
clang/lib/Sema/SemaType.cpp | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 23f2b9d74931b..95257b801c8a6 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5294,9 +5294,8 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// appear only as the first parameter-declaration of a
// parameter-declaration-list of either:
//
- // - a member-declarator that declares a member function [class.mem],
- // or
- // - a lambda-declarator [expr.prim.lambda].
+ // - a member-declarator that declares a member function [class.mem], or
+ // - a lambda-declarator [expr.prim.lambda].
DeclaratorContext C = D.getContext();
ParmVarDecl *First =
FTI.NumParams
>From 8edd57fd41c5c62de628b8ea9cf6b0ff1e4bc535 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 18:25:04 +0200
Subject: [PATCH 04/13] [Clang] Check that the NNS is a class type
---
clang/lib/Sema/SemaType.cpp | 9 ++++++++-
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 5 +++++
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 95257b801c8a6..d8b74b640af40 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5287,6 +5287,13 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// Check for auto functions and trailing return type and adjust the
// return type accordingly.
if (!D.isInvalidType()) {
+ auto isClassType = [&](CXXScopeSpec& SS) {
+ // If there already was an problem with the scope; don’t issue another
+ // error about the explicit object parameter.
+ return SS.isInvalid() ||
+ isa_and_present<CXXRecordDecl>(S.computeDeclContext(SS));
+ };
+
// [dcl.fct]p6:
//
// An explicit-object-parameter-declaration is a parameter-declaration
@@ -5309,7 +5316,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
D.getInnermostNonParenChunk() != &DeclType) &&
// Allow out-of-line definitions if we have a scope spec.
- D.getCXXScopeSpec().isEmpty()) {
+ !isClassType(D.getCXXScopeSpec())) {
S.Diag(First->getBeginLoc(),
diag::err_explicit_object_parameter_invalid)
<< First->getSourceRange();
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index ddb770a92db0f..d2c47b77365cd 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -855,4 +855,9 @@ using U = int (S::*)(this int); // expected-error {{an explicit object parameter
int h(this int); // expected-error {{an explicit object parameter is not allowed here}}
int S::f(this S) { return 1; }
+
+namespace a {
+void f();
+};
+void a::f(this auto) {} // expected-error {{an explicit object parameter is not allowed here}}
}
>From 9c0609cf787cf00685d05ecabf707a885a77cc73 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 19:09:45 +0200
Subject: [PATCH 05/13] [Clang] Handle friends and restore better diagnostic
---
clang/lib/Sema/SemaDeclCXX.cpp | 17 +++++++++++++++++
clang/lib/Sema/SemaType.cpp | 22 +++++++++++++++++-----
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 15 +++++++++++----
3 files changed, 45 insertions(+), 9 deletions(-)
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index ea634df48e5de..1333f8492b40d 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11459,6 +11459,23 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D,
D.setInvalidType();
}
+ // Handle the following case:
+ //
+ // struct S {
+ // struct T {
+ // int f(this T);
+ // };
+ //
+ // friend int T::f(this T); // Allow this.
+ // friend int f(this S); // But disallow this.
+ // };
+ if (D.getDeclSpec().isFriendSpecified() && D.getCXXScopeSpec().isEmpty()) {
+ Diag(ExplicitObjectParam->getBeginLoc(),
+ diag::err_explicit_object_parameter_nonmember)
+ << D.getSourceRange() << /*non-member=*/2 << IsLambda;
+ D.setInvalidType();
+ }
+
if (IsLambda && FTI.hasMutableQualifier()) {
Diag(ExplicitObjectParam->getBeginLoc(),
diag::err_explicit_object_parameter_mutable)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index d8b74b640af40..2c2bdb503a34c 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5308,18 +5308,30 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
FTI.NumParams
? dyn_cast_if_present<ParmVarDecl>(FTI.Params[0].Param)
: nullptr;
+
+ auto IsFunctionDecl = D.getInnermostNonParenChunk() == &DeclType;
if (First && First->isExplicitObjectParameter() &&
C != DeclaratorContext::LambdaExpr &&
// Either not a member or nested declarator in a member.
- (C != DeclaratorContext::Member ||
- D.getInnermostNonParenChunk() != &DeclType) &&
+ //
+ // Note that e.g. 'static' or 'friend' declarations are accepted
+ // here; we diagnose them later when we build the member function
+ // because it's easier that way.
+ (C != DeclaratorContext::Member || !IsFunctionDecl) &&
// Allow out-of-line definitions if we have a scope spec.
!isClassType(D.getCXXScopeSpec())) {
- S.Diag(First->getBeginLoc(),
- diag::err_explicit_object_parameter_invalid)
- << First->getSourceRange();
+ if (IsFunctionDecl)
+ S.Diag(First->getBeginLoc(),
+ diag::err_explicit_object_parameter_nonmember)
+ << /*non-member*/ 2 << /*function*/ 0
+ << First->getSourceRange();
+ else
+ S.Diag(First->getBeginLoc(),
+ diag::err_explicit_object_parameter_invalid)
+ << First->getSourceRange();
+
D.setInvalidType();
AreDeclaratorChunksValid = false;
}
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index d2c47b77365cd..48f963acc27e6 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -5,7 +5,7 @@
void f(this); // expected-error{{variable has incomplete type 'void'}} \
// expected-error{{invalid use of 'this' outside of a non-static member function}}
-void g(this auto); // expected-error{{an explicit object parameter is not allowed here}}
+void g(this auto); // expected-error{{an explicit object parameter cannot appear in a non-member function}}
auto l1 = [] (this auto) static {}; // expected-error{{an explicit object parameter cannot appear in a static lambda}}
auto l2 = [] (this auto) mutable {}; // expected-error{{a lambda with an explicit object parameter cannot be mutable}}
@@ -685,7 +685,7 @@ struct S {
static void j(this S s); // expected-error {{an explicit object parameter cannot appear in a static function}}
};
-void nonmember(this S s); // expected-error {{an explicit object parameter is not allowed here}}
+void nonmember(this S s); // expected-error{{an explicit object parameter cannot appear in a non-member function}}
int test() {
S s;
@@ -847,17 +847,24 @@ struct S {
int f(this S);
int ((g))(this S);
+ friend int h(this S); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
int h(int x, int (*)(this S)); // expected-error {{an explicit object parameter is not allowed here}}
+
+ struct T {
+ int f(this T);
+ };
+
+ friend int T::f(this T);
};
using T = int (*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
using U = int (S::*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
-int h(this int); // expected-error {{an explicit object parameter is not allowed here}}
+int h(this int); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
int S::f(this S) { return 1; }
namespace a {
void f();
};
-void a::f(this auto) {} // expected-error {{an explicit object parameter is not allowed here}}
+void a::f(this auto) {} // expected-error {{an explicit object parameter cannot appear in a non-member function}}
}
>From 853da04fe387f56fa69a468342bb665381db2b79 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 19:10:11 +0200
Subject: [PATCH 06/13] [NFC] clang-format
---
clang/lib/Sema/SemaType.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 2c2bdb503a34c..6a7754dce96d7 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5287,7 +5287,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// Check for auto functions and trailing return type and adjust the
// return type accordingly.
if (!D.isInvalidType()) {
- auto isClassType = [&](CXXScopeSpec& SS) {
+ auto isClassType = [&](CXXScopeSpec &SS) {
// If there already was an problem with the scope; don’t issue another
// error about the explicit object parameter.
return SS.isInvalid() ||
>From 3d91f2fdade769e80251f831926dd8529ff0d99c Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 19:11:28 +0200
Subject: [PATCH 07/13] [NFC] Remove spurious whitespace change
---
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index 48f963acc27e6..7339ffeb2dab3 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -685,7 +685,7 @@ struct S {
static void j(this S s); // expected-error {{an explicit object parameter cannot appear in a static function}}
};
-void nonmember(this S s); // expected-error{{an explicit object parameter cannot appear in a non-member function}}
+void nonmember(this S s); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
int test() {
S s;
>From e3ea2c650c749d4401613b780c912a12dd998f20 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 19:19:08 +0200
Subject: [PATCH 08/13] [NFC] Update comments
---
clang/lib/Sema/SemaType.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 6a7754dce96d7..ac6c93c04f925 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5288,7 +5288,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// return type accordingly.
if (!D.isInvalidType()) {
auto isClassType = [&](CXXScopeSpec &SS) {
- // If there already was an problem with the scope; don’t issue another
+ // If there already was an problem with the scope, don’t issue another
// error about the explicit object parameter.
return SS.isInvalid() ||
isa_and_present<CXXRecordDecl>(S.computeDeclContext(SS));
@@ -5320,7 +5320,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// because it's easier that way.
(C != DeclaratorContext::Member || !IsFunctionDecl) &&
- // Allow out-of-line definitions if we have a scope spec.
+ // Allow out-of-line definitions of member functions.
!isClassType(D.getCXXScopeSpec())) {
if (IsFunctionDecl)
S.Diag(First->getBeginLoc(),
>From 985044944bd21e1a08a8c204a01974c78df18e37 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 23 Apr 2024 19:23:28 +0200
Subject: [PATCH 09/13] [Docs] Add release note
---
clang/docs/ReleaseNotes.rst | 2 ++
1 file changed, 2 insertions(+)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index ade8f4e93d5a0..4d926d7737670 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -539,6 +539,8 @@ Bug Fixes to C++ Support
- Clang now correctly tracks type dependence of by-value captures in lambdas with an explicit
object parameter.
Fixes (#GH70604), (#GH79754), (#GH84163), (#GH84425), (#GH86054), (#GH86398), and (#GH86399).
+- Clang now diagnoses explicit object parameters in member pointers and other contexts where they should not appear.
+ Fixes (#GH85992).
Bug Fixes to AST Handling
^^^^^^^^^^^^^^^^^^^^^^^^^
>From 1d307fef1d9d6e1bee52c5d813f5c5f7805c87d6 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Tue, 28 May 2024 20:08:57 +0200
Subject: [PATCH 10/13] Update clang/lib/Sema/SemaType.cpp
Co-authored-by: Aaron Ballman <aaron at aaronballman.com>
---
clang/lib/Sema/SemaType.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index f371301e89bec..27e39ec4e195d 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4867,7 +4867,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
? dyn_cast_if_present<ParmVarDecl>(FTI.Params[0].Param)
: nullptr;
- auto IsFunctionDecl = D.getInnermostNonParenChunk() == &DeclType;
+ bool IsFunctionDecl = D.getInnermostNonParenChunk() == &DeclType;
if (First && First->isExplicitObjectParameter() &&
C != DeclaratorContext::LambdaExpr &&
>From aa4f66bd3704f8604538239aa0fe9045e3c1a6f8 Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 19 Jun 2024 15:35:09 +0200
Subject: [PATCH 11/13] Handle namespace scope specifiers correctly
---
clang/lib/Sema/SemaDeclCXX.cpp | 15 +++++++++++++--
clang/lib/Sema/SemaType.cpp | 14 ++++++++++----
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 11 +++++++++++
3 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 3445e705131c0..31be0944a8315 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -11401,7 +11401,12 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D,
D.setInvalidType();
}
- // Handle the following case:
+ // Friend declarations require some care. Consider:
+ //
+ // namespace N {
+ // struct A{};
+ // int f(A);
+ // }
//
// struct S {
// struct T {
@@ -11410,8 +11415,14 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D,
//
// friend int T::f(this T); // Allow this.
// friend int f(this S); // But disallow this.
+ // friend int N::f(this A); // And disallow this.
// };
- if (D.getDeclSpec().isFriendSpecified() && D.getCXXScopeSpec().isEmpty()) {
+ //
+ // Here, it seems to suffice to check whether the scope
+ // specifier designates a class type.
+ if (D.getDeclSpec().isFriendSpecified() &&
+ !isa_and_present<CXXRecordDecl>(
+ computeDeclContext(D.getCXXScopeSpec()))) {
Diag(ExplicitObjectParam->getBeginLoc(),
diag::err_explicit_object_parameter_nonmember)
<< D.getSourceRange() << /*non-member=*/2 << IsLambda;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 096c4e6f419e2..057f3e6a6e6c8 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4845,7 +4845,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// Check for auto functions and trailing return type and adjust the
// return type accordingly.
if (!D.isInvalidType()) {
- auto isClassType = [&](CXXScopeSpec &SS) {
+ auto IsClassType = [&](CXXScopeSpec &SS) {
// If there already was an problem with the scope, don’t issue another
// error about the explicit object parameter.
return SS.isInvalid() ||
@@ -4857,9 +4857,15 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
// An explicit-object-parameter-declaration is a parameter-declaration
// with a this specifier. An explicit-object-parameter-declaration shall
// appear only as the first parameter-declaration of a
- // parameter-declaration-list of either:
+ // parameter-declaration-list of one of:
+ //
+ // - a declaration of a member function or member function template
+ // ([class.mem]), or
+ //
+ // - an explicit instantiation ([temp.explicit]) or explicit
+ // specialization ([temp.expl.spec]) of a templated member function,
+ // or
//
- // - a member-declarator that declares a member function [class.mem], or
// - a lambda-declarator [expr.prim.lambda].
DeclaratorContext C = D.getContext();
ParmVarDecl *First =
@@ -4879,7 +4885,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
(C != DeclaratorContext::Member || !IsFunctionDecl) &&
// Allow out-of-line definitions of member functions.
- !isClassType(D.getCXXScopeSpec())) {
+ !IsClassType(D.getCXXScopeSpec())) {
if (IsFunctionDecl)
S.Diag(First->getBeginLoc(),
diag::err_explicit_object_parameter_nonmember)
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index 7409c71b562c6..b6e1f33f0f79e 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -920,6 +920,14 @@ struct C {
}
namespace GH85992 {
+namespace N {
+struct A {
+ int f(this A);
+};
+
+int f(A);
+}
+
struct S {
int (S::*x)(this int); // expected-error {{an explicit object parameter is not allowed here}}
int (*y)(this int); // expected-error {{an explicit object parameter is not allowed here}}
@@ -935,6 +943,9 @@ struct S {
};
friend int T::f(this T);
+ friend int N::A::f(this N::A);
+ friend int N::f(this N::A); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
+ int friend func(this T); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
};
using T = int (*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
>From a7cf358f1519eef75c88e1851b862f3d203a92fd Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Wed, 19 Jun 2024 15:40:03 +0200
Subject: [PATCH 12/13] Improve diagnostic wording a bit
---
clang/include/clang/Basic/DiagnosticSemaKinds.td | 2 +-
clang/test/SemaCXX/cxx2b-deducing-this.cpp | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 875d7a566a58d..bb88720269b0c 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7548,7 +7548,7 @@ def err_explicit_object_lambda_inaccessible_base : Error<
"invalid explicit object parameter type %0 in lambda with capture; "
"the type must derive publicly from the lambda">;
def err_explicit_object_parameter_invalid: Error<
- "an explicit object parameter is not allowed here">;
+ "an explicit object parameter can only appear as the first parameter of a member function">;
def err_ref_qualifier_overload : Error<
"cannot overload a member function %select{without a ref-qualifier|with "
diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
index b6e1f33f0f79e..5cbc1f735383b 100644
--- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp
+++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp
@@ -929,14 +929,14 @@ int f(A);
}
struct S {
- int (S::*x)(this int); // expected-error {{an explicit object parameter is not allowed here}}
- int (*y)(this int); // expected-error {{an explicit object parameter is not allowed here}}
- int (***z)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+ int (S::*x)(this int); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
+ int (*y)(this int); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
+ int (***z)(this int); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
int f(this S);
int ((g))(this S);
friend int h(this S); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
- int h(int x, int (*)(this S)); // expected-error {{an explicit object parameter is not allowed here}}
+ int h(int x, int (*)(this S)); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
struct T {
int f(this T);
@@ -948,8 +948,8 @@ struct S {
int friend func(this T); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
};
-using T = int (*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
-using U = int (S::*)(this int); // expected-error {{an explicit object parameter is not allowed here}}
+using T = int (*)(this int); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
+using U = int (S::*)(this int); // expected-error {{an explicit object parameter can only appear as the first parameter of a member function}}
int h(this int); // expected-error {{an explicit object parameter cannot appear in a non-member function}}
int S::f(this S) { return 1; }
>From f101a97c014478b49b01ee55f493e0c0e41dafdf Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalmail at gmail.com>
Date: Mon, 15 Jul 2024 17:57:59 +0200
Subject: [PATCH 13/13] Update clang/lib/Sema/SemaType.cpp
Co-authored-by: cor3ntin <corentinjabot at gmail.com>
---
clang/lib/Sema/SemaType.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 057f3e6a6e6c8..6bac02f79d8a2 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4852,7 +4852,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
isa_and_present<CXXRecordDecl>(S.computeDeclContext(SS));
};
- // [dcl.fct]p6:
+ // C++23 [dcl.fct]p6:
//
// An explicit-object-parameter-declaration is a parameter-declaration
// with a this specifier. An explicit-object-parameter-declaration shall
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