https://github.com/tru updated https://github.com/llvm/llvm-project/pull/149328
>From 7ac3c6228233980e154cdbc294def0cc66063bc1 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinja...@gmail.com>
Date: Thu, 17 Jul 2025 12:32:49 +0300
Subject: [PATCH] Revert "[Clang] Do not treat Foo -> const Foo conversion
sequences as perfect" (#149272)
Reverts llvm/llvm-project#148613
Considering object argument conversion qualifications perfect leads to
situations where we prefer a non-template const qualified function over
a non-qualified template function, which is very wrong indeed.
I explored solutions to work around that, but instead, we might want to
go the GCC road and prefer the friend overload in the #147374 example,
as this seems a lot more consistent and reliable
(cherry picked from commit 28e1e7e1b4b059a2e42f68061475cddb4ad0a6a3)
---
clang/include/clang/Sema/Overload.h | 11 ++------
clang/lib/Sema/SemaOverload.cpp | 14 +---------
...overload-resolution-deferred-templates.cpp | 28 -------------------
3 files changed, 4 insertions(+), 49 deletions(-)
diff --git a/clang/include/clang/Sema/Overload.h
b/clang/include/clang/Sema/Overload.h
index 9135ff949eeab..a70335bef9dd4 100644
--- a/clang/include/clang/Sema/Overload.h
+++ b/clang/include/clang/Sema/Overload.h
@@ -350,11 +350,6 @@ class Sema;
LLVM_PREFERRED_TYPE(bool)
unsigned BindsToRvalue : 1;
- /// Whether this was an identity conversion with qualification
- /// conversion for the implicit object argument.
- LLVM_PREFERRED_TYPE(bool)
- unsigned IsImplicitObjectArgumentQualificationConversion : 1;
-
/// Whether this binds an implicit object argument to a
/// non-static member function without a ref-qualifier.
LLVM_PREFERRED_TYPE(bool)
@@ -453,11 +448,11 @@ class Sema;
#endif
return true;
}
+ if (!C.hasSameType(getFromType(), getToType(2)))
+ return false;
if (BindsToRvalue && IsLvalueReference)
return false;
- if (IsImplicitObjectArgumentQualificationConversion)
- return C.hasSameUnqualifiedType(getFromType(), getToType(2));
- return C.hasSameType(getFromType(), getToType(2));
+ return true;
}
ImplicitConversionRank getRank() const;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f3baf0c3ef3bc..1b54628c5e564 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -245,7 +245,6 @@ void StandardConversionSequence::setAsIdentityConversion() {
IsLvalueReference = true;
BindsToFunctionLvalue = false;
BindsToRvalue = false;
- IsImplicitObjectArgumentQualificationConversion = false;
BindsImplicitObjectArgumentWithoutRefQualifier = false;
ObjCLifetimeConversionBinding = false;
FromBracedInitList = false;
@@ -5318,7 +5317,6 @@ TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
ICS.Standard.DirectBinding = BindsDirectly;
ICS.Standard.IsLvalueReference = !isRValRef;
ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
- ICS.Standard.IsImplicitObjectArgumentQualificationConversion = false;
ICS.Standard.BindsToRvalue = InitCategory.isRValue();
ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
ICS.Standard.ObjCLifetimeConversionBinding =
@@ -5498,7 +5496,6 @@ TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
ICS.Standard.IsLvalueReference = !isRValRef;
ICS.Standard.BindsToFunctionLvalue = false;
ICS.Standard.BindsToRvalue = true;
- ICS.Standard.IsImplicitObjectArgumentQualificationConversion = false;
ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
ICS.Standard.ObjCLifetimeConversionBinding = false;
} else if (ICS.isUserDefined()) {
@@ -5521,8 +5518,6 @@ TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
ICS.UserDefined.After.IsLvalueReference = !isRValRef;
ICS.UserDefined.After.BindsToFunctionLvalue = false;
ICS.UserDefined.After.BindsToRvalue = !LValRefType;
- ICS.UserDefined.After.IsImplicitObjectArgumentQualificationConversion =
- false;
ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier =
false;
ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
ICS.UserDefined.After.FromBracedInitList = false;
@@ -5807,7 +5802,6 @@ TryListConversion(Sema &S, InitListExpr *From, QualType
ToType,
StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
Result.UserDefined.After;
SCS.ReferenceBinding = true;
- SCS.IsImplicitObjectArgumentQualificationConversion = false;
SCS.IsLvalueReference = ToType->isLValueReferenceType();
SCS.BindsToRvalue = true;
SCS.BindsToFunctionLvalue = false;
@@ -6005,12 +5999,8 @@ static ImplicitConversionSequence
TryObjectArgumentInitialization(
// affects the conversion rank.
QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
ImplicitConversionKind SecondKind;
- bool IsQualificationConversion = false;
- if (ImplicitParamType.getCanonicalType() == FromTypeCanon) {
+ if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
SecondKind = ICK_Identity;
- } else if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
- SecondKind = ICK_Identity;
- IsQualificationConversion = true;
} else if (S.IsDerivedFrom(Loc, FromType, ClassType)) {
SecondKind = ICK_Derived_To_Base;
} else if (!Method->isExplicitObjectMemberFunction()) {
@@ -6051,8 +6041,6 @@ static ImplicitConversionSequence
TryObjectArgumentInitialization(
ICS.Standard.setFromType(FromType);
ICS.Standard.setAllToTypes(ImplicitParamType);
ICS.Standard.ReferenceBinding = true;
- ICS.Standard.IsImplicitObjectArgumentQualificationConversion =
- IsQualificationConversion;
ICS.Standard.DirectBinding = true;
ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
ICS.Standard.BindsToFunctionLvalue = false;
diff --git a/clang/test/SemaCXX/overload-resolution-deferred-templates.cpp
b/clang/test/SemaCXX/overload-resolution-deferred-templates.cpp
index 135865c8450f5..46c3670848529 100644
--- a/clang/test/SemaCXX/overload-resolution-deferred-templates.cpp
+++ b/clang/test/SemaCXX/overload-resolution-deferred-templates.cpp
@@ -283,31 +283,3 @@ void f() {
}
#endif
-
-namespace GH147374 {
-
-struct String {};
-template <typename T> void operator+(T, String &&) = delete;
-
-struct Bar {
- void operator+(String) const; // expected-note {{candidate function}}
- friend void operator+(Bar, String) {}; // expected-note {{candidate
function}}
-};
-
-struct Baz {
- void operator+(String); // expected-note {{candidate function}}
- friend void operator+(Baz, String) {}; // expected-note {{candidate
function}}
-};
-
-void test() {
- Bar a;
- String b;
- a + b;
- //expected-error@-1 {{use of overloaded operator '+' is ambiguous (with
operand types 'Bar' and 'String')}}
-
- Baz z;
- z + b;
- //expected-error@-1 {{use of overloaded operator '+' is ambiguous (with
operand types 'Baz' and 'String')}}
-}
-
-}
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
