[clang] Reapply "[Clang] Fix __is_trivially_equality_comparable returning true with ineligebile defaulted overloads" (#97002) (PR #97894)
Nikolas Klauser via cfe-commits
cfe-commits at lists.llvm.org
Sat Jul 6 05:22:33 PDT 2024
https://github.com/philnik777 created https://github.com/llvm/llvm-project/pull/97894
This reverts commit 567b2c608c307c097315dd5ec4d6a5bbcddf898d.
>From 43b1972a867bf9fa16fdf0d93dcbca4deae9fd13 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Sat, 29 Jun 2024 21:51:02 +0200
Subject: [PATCH] Reapply "[Clang] Fix __is_trivially_equality_comparable
returning true with ineligebile defaulted overloads" (#97002)
This reverts commit 567b2c608c307c097315dd5ec4d6a5bbcddf898d.
---
clang/docs/ReleaseNotes.rst | 5 +-
clang/include/clang/AST/Type.h | 3 --
clang/lib/AST/Type.cpp | 60 -----------------------
clang/lib/Sema/SemaExprCXX.cpp | 79 +++++++++++++++++++++++++++++-
clang/test/SemaCXX/type-traits.cpp | 49 ++++++++++++++++++
5 files changed, 131 insertions(+), 65 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index feba3c7ba8d779..5117b678b22210 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -104,7 +104,7 @@ ABI Changes in This Version
ifuncs. Its purpose was to preserve backwards compatibility when the ".ifunc"
suffix got removed from the name mangling. The alias interacts badly with
GlobalOpt (see the issue #96197).
-
+
- Fixed Microsoft name mangling for auto non-type template arguments of pointer
type for MSVC 1920+. This change resolves incompatibilities with code compiled
by MSVC 1920+ but will introduce incompatibilities with code compiled by
@@ -740,6 +740,9 @@ Bug Fixes in This Version
negatives where the analysis failed to detect unchecked access to guarded
data.
+- ``__is_trivially_equality_comparable`` no longer returns true for types which
+ have a constrained defaulted comparison operator (#GH89293).
+
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 62836ec5c63125..a98899f7f4222c 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -1142,9 +1142,6 @@ class QualType {
/// Return true if this is a trivially relocatable type.
bool isTriviallyRelocatableType(const ASTContext &Context) const;
- /// Return true if this is a trivially equality comparable type.
- bool isTriviallyEqualityComparableType(const ASTContext &Context) const;
-
/// Returns true if it is a class and it might be dynamic.
bool mayBeDynamicClass() const;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index d8b885870de3ac..cc535aba4936e3 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -2815,66 +2815,6 @@ bool QualType::isTriviallyRelocatableType(const ASTContext &Context) const {
}
}
-static bool
-HasNonDeletedDefaultedEqualityComparison(const CXXRecordDecl *Decl) {
- if (Decl->isUnion())
- return false;
- if (Decl->isLambda())
- return Decl->isCapturelessLambda();
-
- auto IsDefaultedOperatorEqualEqual = [&](const FunctionDecl *Function) {
- return Function->getOverloadedOperator() ==
- OverloadedOperatorKind::OO_EqualEqual &&
- Function->isDefaulted() && Function->getNumParams() > 0 &&
- (Function->getParamDecl(0)->getType()->isReferenceType() ||
- Decl->isTriviallyCopyable());
- };
-
- if (llvm::none_of(Decl->methods(), IsDefaultedOperatorEqualEqual) &&
- llvm::none_of(Decl->friends(), [&](const FriendDecl *Friend) {
- if (NamedDecl *ND = Friend->getFriendDecl()) {
- return ND->isFunctionOrFunctionTemplate() &&
- IsDefaultedOperatorEqualEqual(ND->getAsFunction());
- }
- return false;
- }))
- return false;
-
- return llvm::all_of(Decl->bases(),
- [](const CXXBaseSpecifier &BS) {
- if (const auto *RD = BS.getType()->getAsCXXRecordDecl())
- return HasNonDeletedDefaultedEqualityComparison(RD);
- return true;
- }) &&
- llvm::all_of(Decl->fields(), [](const FieldDecl *FD) {
- auto Type = FD->getType();
- if (Type->isArrayType())
- Type = Type->getBaseElementTypeUnsafe()->getCanonicalTypeUnqualified();
-
- if (Type->isReferenceType() || Type->isEnumeralType())
- return false;
- if (const auto *RD = Type->getAsCXXRecordDecl())
- return HasNonDeletedDefaultedEqualityComparison(RD);
- return true;
- });
-}
-
-bool QualType::isTriviallyEqualityComparableType(
- const ASTContext &Context) const {
- QualType CanonicalType = getCanonicalType();
- if (CanonicalType->isIncompleteType() || CanonicalType->isDependentType() ||
- CanonicalType->isEnumeralType() || CanonicalType->isArrayType())
- return false;
-
- if (const auto *RD = CanonicalType->getAsCXXRecordDecl()) {
- if (!HasNonDeletedDefaultedEqualityComparison(RD))
- return false;
- }
-
- return Context.hasUniqueObjectRepresentations(
- CanonicalType, /*CheckIfTriviallyCopyable=*/false);
-}
-
bool QualType::isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const {
return !Context.getLangOpts().ObjCAutoRefCount &&
Context.getLangOpts().ObjCWeak &&
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index f3af8dee6b090c..ae09c7d75214e2 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -5201,6 +5201,83 @@ static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op,
return false;
}
+static bool HasNonDeletedDefaultedEqualityComparison(Sema &S,
+ const CXXRecordDecl *Decl,
+ SourceLocation KeyLoc) {
+ if (Decl->isUnion())
+ return false;
+ if (Decl->isLambda())
+ return Decl->isCapturelessLambda();
+
+ {
+ EnterExpressionEvaluationContext UnevaluatedContext(
+ S, Sema::ExpressionEvaluationContext::Unevaluated);
+ Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
+ Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
+
+ // const ClassT& obj;
+ OpaqueValueExpr Operand(
+ {}, Decl->getTypeForDecl()->getCanonicalTypeUnqualified().withConst(),
+ ExprValueKind::VK_LValue);
+ UnresolvedSet<16> Functions;
+ // obj == obj;
+ S.LookupBinOp(S.TUScope, {}, BinaryOperatorKind::BO_EQ, Functions);
+
+ auto Result = S.CreateOverloadedBinOp(KeyLoc, BinaryOperatorKind::BO_EQ,
+ Functions, &Operand, &Operand);
+ if (Result.isInvalid() || SFINAE.hasErrorOccurred())
+ return false;
+
+ const auto *CallExpr = dyn_cast<CXXOperatorCallExpr>(Result.get());
+ if (!CallExpr)
+ return false;
+ const auto *Callee = CallExpr->getDirectCallee();
+ auto ParamT = Callee->getParamDecl(0)->getType();
+ if (!Callee->isDefaulted())
+ return false;
+ if (!ParamT->isReferenceType() && !Decl->isTriviallyCopyable())
+ return false;
+ if (ParamT.getNonReferenceType()->getUnqualifiedDesugaredType() !=
+ Decl->getTypeForDecl())
+ return false;
+ }
+
+ return llvm::all_of(Decl->bases(),
+ [&](const CXXBaseSpecifier &BS) {
+ if (const auto *RD = BS.getType()->getAsCXXRecordDecl())
+ return HasNonDeletedDefaultedEqualityComparison(
+ S, RD, KeyLoc);
+ return true;
+ }) &&
+ llvm::all_of(Decl->fields(), [&](const FieldDecl *FD) {
+ auto Type = FD->getType();
+ if (Type->isArrayType())
+ Type = Type->getBaseElementTypeUnsafe()
+ ->getCanonicalTypeUnqualified();
+
+ if (Type->isReferenceType() || Type->isEnumeralType())
+ return false;
+ if (const auto *RD = Type->getAsCXXRecordDecl())
+ return HasNonDeletedDefaultedEqualityComparison(S, RD, KeyLoc);
+ return true;
+ });
+}
+
+static bool isTriviallyEqualityComparableType(Sema &S, QualType Type, SourceLocation KeyLoc) {
+ QualType CanonicalType = Type.getCanonicalType();
+ if (CanonicalType->isIncompleteType() || CanonicalType->isDependentType() ||
+ CanonicalType->isEnumeralType() || CanonicalType->isArrayType())
+ return false;
+
+ if (const auto *RD = CanonicalType->getAsCXXRecordDecl()) {
+ if (!HasNonDeletedDefaultedEqualityComparison(S, RD, KeyLoc))
+ return false;
+ }
+
+ return S.getASTContext().hasUniqueObjectRepresentations(
+ CanonicalType, /*CheckIfTriviallyCopyable=*/false);
+}
+
static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
SourceLocation KeyLoc,
TypeSourceInfo *TInfo) {
@@ -5633,7 +5710,7 @@ static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
Self.Diag(KeyLoc, diag::err_builtin_pass_in_regs_non_class) << T;
return false;
case UTT_IsTriviallyEqualityComparable:
- return T.isTriviallyEqualityComparableType(C);
+ return isTriviallyEqualityComparableType(Self, T, KeyLoc);
}
}
diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp
index d40605f56f1edd..7adbf4aad7afe0 100644
--- a/clang/test/SemaCXX/type-traits.cpp
+++ b/clang/test/SemaCXX/type-traits.cpp
@@ -3677,6 +3677,12 @@ struct NonTriviallyEqualityComparableNoComparator {
};
static_assert(!__is_trivially_equality_comparable(NonTriviallyEqualityComparableNoComparator));
+struct NonTriviallyEqualityComparableConvertibleToBuiltin {
+ int i;
+ operator unsigned() const;
+};
+static_assert(!__is_trivially_equality_comparable(NonTriviallyEqualityComparableConvertibleToBuiltin));
+
struct NonTriviallyEqualityComparableNonDefaultedComparator {
int i;
int j;
@@ -3885,8 +3891,51 @@ struct NotTriviallyEqualityComparableNonTriviallyEqualityComparableArrs2 {
bool operator==(const NotTriviallyEqualityComparableNonTriviallyEqualityComparableArrs2&) const = default;
};
+
static_assert(!__is_trivially_equality_comparable(NotTriviallyEqualityComparableNonTriviallyEqualityComparableArrs2));
+template<bool B>
+struct MaybeTriviallyEqualityComparable {
+ int i;
+ bool operator==(const MaybeTriviallyEqualityComparable&) const requires B = default;
+ bool operator==(const MaybeTriviallyEqualityComparable& rhs) const { return (i % 3) == (rhs.i % 3); }
+};
+static_assert(__is_trivially_equality_comparable(MaybeTriviallyEqualityComparable<true>));
+static_assert(!__is_trivially_equality_comparable(MaybeTriviallyEqualityComparable<false>));
+
+struct NotTriviallyEqualityComparableMoreConstrainedExternalOp {
+ int i;
+ bool operator==(const NotTriviallyEqualityComparableMoreConstrainedExternalOp&) const = default;
+};
+
+bool operator==(const NotTriviallyEqualityComparableMoreConstrainedExternalOp&,
+ const NotTriviallyEqualityComparableMoreConstrainedExternalOp&) __attribute__((enable_if(true, ""))) {}
+
+static_assert(!__is_trivially_equality_comparable(NotTriviallyEqualityComparableMoreConstrainedExternalOp));
+
+struct TriviallyEqualityComparableExternalDefaultedOp {
+ int i;
+ friend bool operator==(TriviallyEqualityComparableExternalDefaultedOp, TriviallyEqualityComparableExternalDefaultedOp);
+};
+bool operator==(TriviallyEqualityComparableExternalDefaultedOp, TriviallyEqualityComparableExternalDefaultedOp) = default;
+
+static_assert(__is_trivially_equality_comparable(TriviallyEqualityComparableExternalDefaultedOp));
+
+struct EqualityComparableBase {
+ bool operator==(const EqualityComparableBase&) const = default;
+};
+
+struct ComparingBaseOnly : EqualityComparableBase {
+ int j_ = 0;
+};
+static_assert(!__is_trivially_equality_comparable(ComparingBaseOnly));
+
+template <class>
+class Template {};
+
+// Make sure we don't crash when instantiating a type
+static_assert(!__is_trivially_equality_comparable(Template<Template<int>>));
+
namespace hidden_friend {
struct TriviallyEqualityComparable {
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