https://github.com/cor3ntin created
https://github.com/llvm/llvm-project/pull/141238
`static_assert(std::is_xx_v<MyType>);` is a common pattern to check that a type
meets a requirement.
This patch produces diagnostics notes when such assertion fails. The first type
trait for which we provide detailed explanation is
std::is_trivially_relocatable.
We employ the same mechanisn when a type trait appears an an unsatisfied atomic
constraint.
I plan to also support `std::is_trivially_replaceable` in a follow up PR, and
hopefully, over time we can support more type traits.
>From 5ffeedb51facf82dc446f852ead90ba040d4d659 Mon Sep 17 00:00:00 2001
From: Corentin Jabot <corentinja...@gmail.com>
Date: Wed, 21 May 2025 23:10:36 +0200
Subject: [PATCH] [Clang] Explain why a type trait evaluated to false.
`static_assert(std::is_xx_v<MyType>);` is a common pattern
to check that a type meets a requirement.
This patch produces diagnostics notes when such assertion fails.
The first type trait for which we provide detailed explanation
is std::is_trivially_relocatable.
We employ the same mechanisn when a type trait appears an
an unsatisfied atomic constraint.
I plan to also support `std::is_trivially_replaceable` in a follow up PR,
and hopefully, over time we can support more type traits.
---
.../clang/Basic/DiagnosticSemaKinds.td | 23 +
clang/include/clang/Sema/Sema.h | 5 +
clang/lib/Sema/CMakeLists.txt | 1 +
clang/lib/Sema/SemaConcept.cpp | 1 +
clang/lib/Sema/SemaDeclCXX.cpp | 275 +--------
clang/lib/Sema/SemaExprCXX.cpp | 65 +--
clang/lib/Sema/SemaTypeTraits.cpp | 539 ++++++++++++++++++
.../type-traits-unsatisfied-diags-std.cpp | 101 ++++
.../SemaCXX/type-traits-unsatisfied-diags.cpp | 146 +++++
.../test/SemaObjCXX/objc-weak-type-traits.mm | 7 +-
10 files changed, 826 insertions(+), 337 deletions(-)
create mode 100644 clang/lib/Sema/SemaTypeTraits.cpp
create mode 100644 clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
create mode 100644 clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td
b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 2835e3a9d9960..f2fcfe5d351f4 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1762,6 +1762,29 @@ def err_user_defined_msg_constexpr : Error<
"%sub{subst_user_defined_msg}0 must be produced by a "
"constant expression">;
+// Type traits explanations
+def note_unsatisfied_trait : Note<"%0 is not %enum_select<TraitName>{"
+ "%TriviallyRelocatable{trivially
relocatable}"
+ "}1">;
+
+def note_unsatisfied_trait_reason
+ : Note<"because it "
+ "%enum_select<TraitNotSatisfiedReason>{"
+ "%Ref{is a reference type}|"
+ "%HasArcLifetime{has an ARC lifetime qualifier}|"
+ "%VLA{is a variably-modified type}|"
+ "%VBase{has a virtual base %1}|"
+ "%NRBase{has a non-trivially-relocatable base %1}|"
+ "%NRField{has a non-trivially-relocatable member %1 of type %2}|"
+ "%DeletedDtr{has a %select{deleted|user-provided}1 destructor}|"
+ "%UserProvidedCtr{has a user provided %select{copy|move}1 "
+ "constructor}|"
+ "%UserProvidedAssign{has a user provided %select{copy|move}1 "
+ "assignment operator}|"
+ "%UnionWithUserDeclaredSMF{is a union with a user-declared "
+ "%sub{select_special_member_kind}1}"
+ "}0">;
+
def warn_consteval_if_always_true : Warning<
"consteval if is always true in an %select{unevaluated|immediate}0 context">,
InGroup<DiagGroup<"redundant-consteval-if">>;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 1091a7f504b57..bbc5c181c6a10 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -5910,6 +5910,11 @@ class Sema final : public SemaBase {
/// with expression \E
void DiagnoseStaticAssertDetails(const Expr *E);
+ /// If E represents a built-in type trait, or a known standard type trait,
+ /// try to print more information about why the type type-trait failed.
+ /// This assumes we already evaluated the expression to a false boolean
value.
+ void DiagnoseTypeTraitDetails(const Expr *E);
+
/// Handle a friend type declaration. This works in tandem with
/// ActOnTag.
///
diff --git a/clang/lib/Sema/CMakeLists.txt b/clang/lib/Sema/CMakeLists.txt
index 4b87004e4b8ea..51e0ee10b080b 100644
--- a/clang/lib/Sema/CMakeLists.txt
+++ b/clang/lib/Sema/CMakeLists.txt
@@ -96,6 +96,7 @@ add_clang_library(clangSema
SemaTemplateInstantiateDecl.cpp
SemaTemplateVariadic.cpp
SemaType.cpp
+ SemaTypeTraits.cpp
SemaWasm.cpp
SemaX86.cpp
TypeLocBuilder.cpp
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index 7da8e696c90bd..c6a54dc141ded 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -1320,6 +1320,7 @@ static void
diagnoseWellFormedUnsatisfiedConstraintExpr(Sema &S,
S.Diag(SubstExpr->getSourceRange().getBegin(),
diag::note_atomic_constraint_evaluated_to_false)
<< (int)First << SubstExpr;
+ S.DiagnoseTypeTraitDetails(SubstExpr);
}
template <typename SubstitutionDiagnostic>
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index fe92191b6a687..770ac9839eb98 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -7368,279 +7368,6 @@ void Sema::CheckCompletedCXXClass(Scope *S,
CXXRecordDecl *Record) {
CheckMismatchedTypeAwareAllocators(OO_Array_New, OO_Array_Delete);
}
-static CXXMethodDecl *LookupSpecialMemberFromXValue(Sema &SemaRef,
- const CXXRecordDecl *RD,
- bool Assign) {
- RD = RD->getDefinition();
- SourceLocation LookupLoc = RD->getLocation();
-
- CanQualType CanTy = SemaRef.getASTContext().getCanonicalType(
- SemaRef.getASTContext().getTagDeclType(RD));
- DeclarationName Name;
- Expr *Arg = nullptr;
- unsigned NumArgs;
-
- QualType ArgType = CanTy;
- ExprValueKind VK = clang::VK_XValue;
-
- if (Assign)
- Name =
- SemaRef.getASTContext().DeclarationNames.getCXXOperatorName(OO_Equal);
- else
- Name =
- SemaRef.getASTContext().DeclarationNames.getCXXConstructorName(CanTy);
-
- OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
- NumArgs = 1;
- Arg = &FakeArg;
-
- // Create the object argument
- QualType ThisTy = CanTy;
- Expr::Classification Classification =
- OpaqueValueExpr(LookupLoc, ThisTy, VK_LValue)
- .Classify(SemaRef.getASTContext());
-
- // Now we perform lookup on the name we computed earlier and do overload
- // resolution. Lookup is only performed directly into the class since there
- // will always be a (possibly implicit) declaration to shadow any others.
- OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
- DeclContext::lookup_result R = RD->lookup(Name);
-
- if (R.empty())
- return nullptr;
-
- // Copy the candidates as our processing of them may load new declarations
- // from an external source and invalidate lookup_result.
- SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
-
- for (NamedDecl *CandDecl : Candidates) {
- if (CandDecl->isInvalidDecl())
- continue;
-
- DeclAccessPair Cand = DeclAccessPair::make(CandDecl, clang::AS_none);
- auto CtorInfo = getConstructorInfo(Cand);
- if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl()))
{
- if (Assign)
- SemaRef.AddMethodCandidate(M, Cand, const_cast<CXXRecordDecl *>(RD),
- ThisTy, Classification,
- llvm::ArrayRef(&Arg, NumArgs), OCS, true);
- else {
- assert(CtorInfo);
- SemaRef.AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
- llvm::ArrayRef(&Arg, NumArgs), OCS,
- /*SuppressUserConversions*/ true);
- }
- } else if (FunctionTemplateDecl *Tmpl =
- dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
- if (Assign)
- SemaRef.AddMethodTemplateCandidate(
- Tmpl, Cand, const_cast<CXXRecordDecl *>(RD), nullptr, ThisTy,
- Classification, llvm::ArrayRef(&Arg, NumArgs), OCS, true);
- else {
- assert(CtorInfo);
- SemaRef.AddTemplateOverloadCandidate(
- CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
- llvm::ArrayRef(&Arg, NumArgs), OCS, true);
- }
- }
- }
-
- OverloadCandidateSet::iterator Best;
- switch (OCS.BestViableFunction(SemaRef, LookupLoc, Best)) {
- case OR_Success:
- return cast<CXXMethodDecl>(Best->Function);
- default:
- return nullptr;
- }
-}
-
-static bool hasSuitableConstructorForRelocation(Sema &SemaRef,
- const CXXRecordDecl *D,
- bool AllowUserDefined) {
- assert(D->hasDefinition() && !D->isInvalidDecl());
-
- if (D->hasSimpleMoveConstructor() || D->hasSimpleCopyConstructor())
- return true;
-
- CXXMethodDecl *Decl =
- LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/false);
- return Decl && Decl->isUserProvided() == AllowUserDefined;
-}
-
-static bool hasSuitableMoveAssignmentOperatorForRelocation(
- Sema &SemaRef, const CXXRecordDecl *D, bool AllowUserDefined) {
- assert(D->hasDefinition() && !D->isInvalidDecl());
-
- if (D->hasSimpleMoveAssignment() || D->hasSimpleCopyAssignment())
- return true;
-
- CXXMethodDecl *Decl =
- LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/true);
- if (!Decl)
- return false;
-
- return Decl && Decl->isUserProvided() == AllowUserDefined;
-}
-
-// [C++26][class.prop]
-// A class C is default-movable if
-// - overload resolution for direct-initializing an object of type C
-// from an xvalue of type C selects a constructor that is a direct member of C
-// and is neither user-provided nor deleted,
-// - overload resolution for assigning to an lvalue of type C from an xvalue of
-// type C selects an assignment operator function that is a direct member of C
-// and is neither user-provided nor deleted, and C has a destructor that is
-// neither user-provided nor deleted.
-static bool IsDefaultMovable(Sema &SemaRef, const CXXRecordDecl *D) {
- if (!hasSuitableConstructorForRelocation(SemaRef, D,
- /*AllowUserDefined=*/false))
- return false;
-
- if (!hasSuitableMoveAssignmentOperatorForRelocation(
- SemaRef, D, /*AllowUserDefined=*/false))
- return false;
-
- CXXDestructorDecl *Dtr = D->getDestructor();
-
- if (!Dtr)
- return true;
-
- if (Dtr->isUserProvided() && (!Dtr->isDefaulted() || Dtr->isDeleted()))
- return false;
-
- return !Dtr->isDeleted();
-}
-
-// [C++26][class.prop]
-// A class is eligible for trivial relocation unless it...
-static bool IsEligibleForTrivialRelocation(Sema &SemaRef,
- const CXXRecordDecl *D) {
-
- for (const CXXBaseSpecifier &B : D->bases()) {
- const auto *BaseDecl = B.getType()->getAsCXXRecordDecl();
- if (!BaseDecl)
- continue;
- // ... has any virtual base classes
- // ... has a base class that is not a trivially relocatable class
- if (B.isVirtual() || (!BaseDecl->isDependentType() &&
- !SemaRef.IsCXXTriviallyRelocatableType(B.getType())))
- return false;
- }
-
- for (const FieldDecl *Field : D->fields()) {
- if (Field->getType()->isDependentType())
- continue;
- if (Field->getType()->isReferenceType())
- continue;
- // ... has a non-static data member of an object type that is not
- // of a trivially relocatable type
- if (!SemaRef.IsCXXTriviallyRelocatableType(Field->getType()))
- return false;
- }
- return !D->hasDeletedDestructor();
-}
-
-// [C++26][class.prop]
-// A class C is eligible for replacement unless
-static bool IsEligibleForReplacement(Sema &SemaRef, const CXXRecordDecl *D) {
-
- for (const CXXBaseSpecifier &B : D->bases()) {
- const auto *BaseDecl = B.getType()->getAsCXXRecordDecl();
- if (!BaseDecl)
- continue;
- // it has a base class that is not a replaceable class
- if (!BaseDecl->isDependentType() &&
- !SemaRef.IsCXXReplaceableType(B.getType()))
- return false;
- }
-
- for (const FieldDecl *Field : D->fields()) {
- if (Field->getType()->isDependentType())
- continue;
-
- // it has a non-static data member that is not of a replaceable type,
- if (!SemaRef.IsCXXReplaceableType(Field->getType()))
- return false;
- }
- return !D->hasDeletedDestructor();
-}
-
-ASTContext::CXXRecordDeclRelocationInfo
-Sema::CheckCXX2CRelocatableAndReplaceable(const CXXRecordDecl *D) {
- ASTContext::CXXRecordDeclRelocationInfo Info{false, false};
-
- if (!getLangOpts().CPlusPlus || D->isInvalidDecl())
- return Info;
-
- assert(D->hasDefinition());
-
- // This is part of "eligible for replacement", however we defer it
- // to avoid extraneous computations.
- auto HasSuitableSMP = [&] {
- return hasSuitableConstructorForRelocation(*this, D,
- /*AllowUserDefined=*/true) &&
- hasSuitableMoveAssignmentOperatorForRelocation(
- *this, D, /*AllowUserDefined=*/true);
- };
-
- auto IsUnion = [&, Is = std::optional<bool>{}]() mutable {
- if (!Is.has_value())
- Is = D->isUnion() && !D->hasUserDeclaredCopyConstructor() &&
- !D->hasUserDeclaredCopyAssignment() &&
- !D->hasUserDeclaredMoveOperation() &&
- !D->hasUserDeclaredDestructor();
- return *Is;
- };
-
- auto IsDefaultMovable = [&, Is = std::optional<bool>{}]() mutable {
- if (!Is.has_value())
- Is = ::IsDefaultMovable(*this, D);
- return *Is;
- };
-
- Info.IsRelocatable = [&] {
- if (D->isDependentType())
- return false;
-
- // if it is eligible for trivial relocation
- if (!IsEligibleForTrivialRelocation(*this, D))
- return false;
-
- // has the trivially_relocatable_if_eligible class-property-specifier,
- if (D->hasAttr<TriviallyRelocatableAttr>())
- return true;
-
- // is a union with no user-declared special member functions, or
- if (IsUnion())
- return true;
-
- // is default-movable.
- return IsDefaultMovable();
- }();
-
- Info.IsReplaceable = [&] {
- if (D->isDependentType())
- return false;
-
- // A class C is a replaceable class if it is eligible for replacement
- if (!IsEligibleForReplacement(*this, D))
- return false;
-
- // has the replaceable_if_eligible class-property-specifier
- if (D->hasAttr<ReplaceableAttr>())
- return HasSuitableSMP();
-
- // is a union with no user-declared special member functions, or
- if (IsUnion())
- return HasSuitableSMP();
-
- // is default-movable.
- return IsDefaultMovable();
- }();
-
- return Info;
-}
-
/// Look up the special member function that would be called by a special
/// member function for a subobject of class type.
///
@@ -17967,6 +17694,8 @@ void Sema::DiagnoseStaticAssertDetails(const Expr *E) {
<< DiagSide[0].ValueString << Op->getOpcodeStr()
<< DiagSide[1].ValueString << Op->getSourceRange();
}
+ } else {
+ DiagnoseTypeTraitDetails(E);
}
}
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index b53877c40668d..3640483fd3706 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -5590,69 +5590,8 @@ static bool isTriviallyEqualityComparableType(Sema &S,
QualType Type, SourceLoca
CanonicalType, /*CheckIfTriviallyCopyable=*/false);
}
-static bool IsCXXTriviallyRelocatableType(Sema &S, const CXXRecordDecl *RD) {
- if (std::optional<ASTContext::CXXRecordDeclRelocationInfo> Info =
- S.getASTContext().getRelocationInfoForCXXRecord(RD))
- return Info->IsRelocatable;
- ASTContext::CXXRecordDeclRelocationInfo Info =
- S.CheckCXX2CRelocatableAndReplaceable(RD);
- S.getASTContext().setRelocationInfoForCXXRecord(RD, Info);
- return Info.IsRelocatable;
-}
-
-bool Sema::IsCXXTriviallyRelocatableType(QualType Type) {
-
- QualType BaseElementType = getASTContext().getBaseElementType(Type);
-
- if (Type->isVariableArrayType())
- return false;
-
- if (BaseElementType.hasNonTrivialObjCLifetime())
- return false;
-
- if (BaseElementType.hasAddressDiscriminatedPointerAuth())
- return false;
-
- if (BaseElementType->isIncompleteType())
- return false;
-
- if (BaseElementType->isScalarType() || BaseElementType->isVectorType())
- return true;
-
- if (const auto *RD = BaseElementType->getAsCXXRecordDecl())
- return ::IsCXXTriviallyRelocatableType(*this, RD);
-
- return false;
-}
-
-static bool IsCXXReplaceableType(Sema &S, const CXXRecordDecl *RD) {
- if (std::optional<ASTContext::CXXRecordDeclRelocationInfo> Info =
- S.getASTContext().getRelocationInfoForCXXRecord(RD))
- return Info->IsReplaceable;
- ASTContext::CXXRecordDeclRelocationInfo Info =
- S.CheckCXX2CRelocatableAndReplaceable(RD);
- S.getASTContext().setRelocationInfoForCXXRecord(RD, Info);
- return Info.IsReplaceable;
-}
-
-bool Sema::IsCXXReplaceableType(QualType Type) {
- if (Type.isConstQualified() || Type.isVolatileQualified())
- return false;
-
- if (Type->isVariableArrayType())
- return false;
-
- QualType BaseElementType =
- getASTContext().getBaseElementType(Type.getUnqualifiedType());
- if (BaseElementType->isIncompleteType())
- return false;
- if (BaseElementType->isScalarType())
- return true;
- if (const auto *RD = BaseElementType->getAsCXXRecordDecl())
- return ::IsCXXReplaceableType(*this, RD);
- return false;
-}
-
+// FIXME : Move the type traits logic to SemaTypeTraits.h
+extern bool IsCXXTriviallyRelocatableType(Sema &S, const CXXRecordDecl *RD);
static bool IsTriviallyRelocatableType(Sema &SemaRef, QualType T) {
QualType BaseElementType = SemaRef.getASTContext().getBaseElementType(T);
diff --git a/clang/lib/Sema/SemaTypeTraits.cpp
b/clang/lib/Sema/SemaTypeTraits.cpp
new file mode 100644
index 0000000000000..d16989e8dfdbe
--- /dev/null
+++ b/clang/lib/Sema/SemaTypeTraits.cpp
@@ -0,0 +1,539 @@
+//===----- SemaTypeTraits.cpp - Semantic Analysis for C++ Type Traits
-----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM
Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements semantic analysis for C++ type traits.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/DeclCXX.h"
+#include "clang/Basic/DiagnosticSema.h"
+#include "clang/Sema/Overload.h"
+#include "clang/Sema/Sema.h"
+
+using namespace clang;
+
+static CXXMethodDecl *LookupSpecialMemberFromXValue(Sema &SemaRef,
+ const CXXRecordDecl *RD,
+ bool Assign) {
+ RD = RD->getDefinition();
+ SourceLocation LookupLoc = RD->getLocation();
+
+ CanQualType CanTy = SemaRef.getASTContext().getCanonicalType(
+ SemaRef.getASTContext().getTagDeclType(RD));
+ DeclarationName Name;
+ Expr *Arg = nullptr;
+ unsigned NumArgs;
+
+ QualType ArgType = CanTy;
+ ExprValueKind VK = clang::VK_XValue;
+
+ if (Assign)
+ Name =
+ SemaRef.getASTContext().DeclarationNames.getCXXOperatorName(OO_Equal);
+ else
+ Name =
+ SemaRef.getASTContext().DeclarationNames.getCXXConstructorName(CanTy);
+
+ OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
+ NumArgs = 1;
+ Arg = &FakeArg;
+
+ // Create the object argument
+ QualType ThisTy = CanTy;
+ Expr::Classification Classification =
+ OpaqueValueExpr(LookupLoc, ThisTy, VK_LValue)
+ .Classify(SemaRef.getASTContext());
+
+ // Now we perform lookup on the name we computed earlier and do overload
+ // resolution. Lookup is only performed directly into the class since there
+ // will always be a (possibly implicit) declaration to shadow any others.
+ OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
+ DeclContext::lookup_result R = RD->lookup(Name);
+
+ if (R.empty())
+ return nullptr;
+
+ // Copy the candidates as our processing of them may load new declarations
+ // from an external source and invalidate lookup_result.
+ SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
+
+ for (NamedDecl *CandDecl : Candidates) {
+ if (CandDecl->isInvalidDecl())
+ continue;
+
+ DeclAccessPair Cand = DeclAccessPair::make(CandDecl, clang::AS_none);
+ auto CtorInfo = getConstructorInfo(Cand);
+ if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl()))
{
+ if (Assign)
+ SemaRef.AddMethodCandidate(M, Cand, const_cast<CXXRecordDecl *>(RD),
+ ThisTy, Classification,
+ llvm::ArrayRef(&Arg, NumArgs), OCS, true);
+ else {
+ assert(CtorInfo);
+ SemaRef.AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
+ llvm::ArrayRef(&Arg, NumArgs), OCS,
+ /*SuppressUserConversions*/ true);
+ }
+ } else if (FunctionTemplateDecl *Tmpl =
+ dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
+ if (Assign)
+ SemaRef.AddMethodTemplateCandidate(
+ Tmpl, Cand, const_cast<CXXRecordDecl *>(RD), nullptr, ThisTy,
+ Classification, llvm::ArrayRef(&Arg, NumArgs), OCS, true);
+ else {
+ assert(CtorInfo);
+ SemaRef.AddTemplateOverloadCandidate(
+ CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
+ llvm::ArrayRef(&Arg, NumArgs), OCS, true);
+ }
+ }
+ }
+
+ OverloadCandidateSet::iterator Best;
+ switch (OCS.BestViableFunction(SemaRef, LookupLoc, Best)) {
+ case OR_Success:
+ return cast<CXXMethodDecl>(Best->Function);
+ default:
+ return nullptr;
+ }
+}
+
+static bool hasSuitableConstructorForRelocation(Sema &SemaRef,
+ const CXXRecordDecl *D,
+ bool AllowUserDefined) {
+ assert(D->hasDefinition() && !D->isInvalidDecl());
+
+ if (D->hasSimpleMoveConstructor() || D->hasSimpleCopyConstructor())
+ return true;
+
+ CXXMethodDecl *Decl =
+ LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/false);
+ return Decl && Decl->isUserProvided() == AllowUserDefined;
+}
+
+static bool hasSuitableMoveAssignmentOperatorForRelocation(
+ Sema &SemaRef, const CXXRecordDecl *D, bool AllowUserDefined) {
+ assert(D->hasDefinition() && !D->isInvalidDecl());
+
+ if (D->hasSimpleMoveAssignment() || D->hasSimpleCopyAssignment())
+ return true;
+
+ CXXMethodDecl *Decl =
+ LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/true);
+ if (!Decl)
+ return false;
+
+ return Decl && Decl->isUserProvided() == AllowUserDefined;
+}
+
+// [C++26][class.prop]
+// A class C is default-movable if
+// - overload resolution for direct-initializing an object of type C
+// from an xvalue of type C selects a constructor that is a direct member of C
+// and is neither user-provided nor deleted,
+// - overload resolution for assigning to an lvalue of type C from an xvalue of
+// type C selects an assignment operator function that is a direct member of C
+// and is neither user-provided nor deleted, and C has a destructor that is
+// neither user-provided nor deleted.
+static bool IsDefaultMovable(Sema &SemaRef, const CXXRecordDecl *D) {
+ if (!hasSuitableConstructorForRelocation(SemaRef, D,
+ /*AllowUserDefined=*/false))
+ return false;
+
+ if (!hasSuitableMoveAssignmentOperatorForRelocation(
+ SemaRef, D, /*AllowUserDefined=*/false))
+ return false;
+
+ CXXDestructorDecl *Dtr = D->getDestructor();
+
+ if (!Dtr)
+ return true;
+
+ if (Dtr->isUserProvided() && (!Dtr->isDefaulted() || Dtr->isDeleted()))
+ return false;
+
+ return !Dtr->isDeleted();
+}
+
+// [C++26][class.prop]
+// A class is eligible for trivial relocation unless it...
+static bool IsEligibleForTrivialRelocation(Sema &SemaRef,
+ const CXXRecordDecl *D) {
+
+ for (const CXXBaseSpecifier &B : D->bases()) {
+ const auto *BaseDecl = B.getType()->getAsCXXRecordDecl();
+ if (!BaseDecl)
+ continue;
+ // ... has any virtual base classes
+ // ... has a base class that is not a trivially relocatable class
+ if (B.isVirtual() || (!BaseDecl->isDependentType() &&
+ !SemaRef.IsCXXTriviallyRelocatableType(B.getType())))
+ return false;
+ }
+
+ for (const FieldDecl *Field : D->fields()) {
+ if (Field->getType()->isDependentType())
+ continue;
+ if (Field->getType()->isReferenceType())
+ continue;
+ // ... has a non-static data member of an object type that is not
+ // of a trivially relocatable type
+ if (!SemaRef.IsCXXTriviallyRelocatableType(Field->getType()))
+ return false;
+ }
+ return !D->hasDeletedDestructor();
+}
+
+// [C++26][class.prop]
+// A class C is eligible for replacement unless
+static bool IsEligibleForReplacement(Sema &SemaRef, const CXXRecordDecl *D) {
+
+ for (const CXXBaseSpecifier &B : D->bases()) {
+ const auto *BaseDecl = B.getType()->getAsCXXRecordDecl();
+ if (!BaseDecl)
+ continue;
+ // it has a base class that is not a replaceable class
+ if (!BaseDecl->isDependentType() &&
+ !SemaRef.IsCXXReplaceableType(B.getType()))
+ return false;
+ }
+
+ for (const FieldDecl *Field : D->fields()) {
+ if (Field->getType()->isDependentType())
+ continue;
+
+ // it has a non-static data member that is not of a replaceable type,
+ if (!SemaRef.IsCXXReplaceableType(Field->getType()))
+ return false;
+ }
+ return !D->hasDeletedDestructor();
+}
+
+ASTContext::CXXRecordDeclRelocationInfo
+Sema::CheckCXX2CRelocatableAndReplaceable(const CXXRecordDecl *D) {
+ ASTContext::CXXRecordDeclRelocationInfo Info{false, false};
+
+ if (!getLangOpts().CPlusPlus || D->isInvalidDecl())
+ return Info;
+
+ assert(D->hasDefinition());
+
+ // This is part of "eligible for replacement", however we defer it
+ // to avoid extraneous computations.
+ auto HasSuitableSMP = [&] {
+ return hasSuitableConstructorForRelocation(*this, D,
+ /*AllowUserDefined=*/true) &&
+ hasSuitableMoveAssignmentOperatorForRelocation(
+ *this, D, /*AllowUserDefined=*/true);
+ };
+
+ auto IsUnion = [&, Is = std::optional<bool>{}]() mutable {
+ if (!Is.has_value())
+ Is = D->isUnion() && !D->hasUserDeclaredCopyConstructor() &&
+ !D->hasUserDeclaredCopyAssignment() &&
+ !D->hasUserDeclaredMoveOperation() &&
+ !D->hasUserDeclaredDestructor();
+ return *Is;
+ };
+
+ auto IsDefaultMovable = [&, Is = std::optional<bool>{}]() mutable {
+ if (!Is.has_value())
+ Is = ::IsDefaultMovable(*this, D);
+ return *Is;
+ };
+
+ Info.IsRelocatable = [&] {
+ if (D->isDependentType())
+ return false;
+
+ // if it is eligible for trivial relocation
+ if (!IsEligibleForTrivialRelocation(*this, D))
+ return false;
+
+ // has the trivially_relocatable_if_eligible class-property-specifier,
+ if (D->hasAttr<TriviallyRelocatableAttr>())
+ return true;
+
+ // is a union with no user-declared special member functions, or
+ if (IsUnion())
+ return true;
+
+ // is default-movable.
+ return IsDefaultMovable();
+ }();
+
+ Info.IsReplaceable = [&] {
+ if (D->isDependentType())
+ return false;
+
+ // A class C is a replaceable class if it is eligible for replacement
+ if (!IsEligibleForReplacement(*this, D))
+ return false;
+
+ // has the replaceable_if_eligible class-property-specifier
+ if (D->hasAttr<ReplaceableAttr>())
+ return HasSuitableSMP();
+
+ // is a union with no user-declared special member functions, or
+ if (IsUnion())
+ return HasSuitableSMP();
+
+ // is default-movable.
+ return IsDefaultMovable();
+ }();
+
+ return Info;
+}
+
+bool IsCXXTriviallyRelocatableType(Sema &S, const CXXRecordDecl *RD) {
+ if (std::optional<ASTContext::CXXRecordDeclRelocationInfo> Info =
+ S.getASTContext().getRelocationInfoForCXXRecord(RD))
+ return Info->IsRelocatable;
+ ASTContext::CXXRecordDeclRelocationInfo Info =
+ S.CheckCXX2CRelocatableAndReplaceable(RD);
+ S.getASTContext().setRelocationInfoForCXXRecord(RD, Info);
+ return Info.IsRelocatable;
+}
+
+bool Sema::IsCXXTriviallyRelocatableType(QualType Type) {
+
+ QualType BaseElementType = getASTContext().getBaseElementType(Type);
+
+ if (Type->isVariableArrayType())
+ return false;
+
+ if (BaseElementType.hasNonTrivialObjCLifetime())
+ return false;
+
+ if (BaseElementType.hasAddressDiscriminatedPointerAuth())
+ return false;
+
+ if (BaseElementType->isIncompleteType())
+ return false;
+
+ if (BaseElementType->isScalarType() || BaseElementType->isVectorType())
+ return true;
+
+ if (const auto *RD = BaseElementType->getAsCXXRecordDecl())
+ return ::IsCXXTriviallyRelocatableType(*this, RD);
+
+ return false;
+}
+
+static bool IsCXXReplaceableType(Sema &S, const CXXRecordDecl *RD) {
+ if (std::optional<ASTContext::CXXRecordDeclRelocationInfo> Info =
+ S.getASTContext().getRelocationInfoForCXXRecord(RD))
+ return Info->IsReplaceable;
+ ASTContext::CXXRecordDeclRelocationInfo Info =
+ S.CheckCXX2CRelocatableAndReplaceable(RD);
+ S.getASTContext().setRelocationInfoForCXXRecord(RD, Info);
+ return Info.IsReplaceable;
+}
+
+bool Sema::IsCXXReplaceableType(QualType Type) {
+ if (Type.isConstQualified() || Type.isVolatileQualified())
+ return false;
+
+ if (Type->isVariableArrayType())
+ return false;
+
+ QualType BaseElementType =
+ getASTContext().getBaseElementType(Type.getUnqualifiedType());
+ if (BaseElementType->isIncompleteType())
+ return false;
+ if (BaseElementType->isScalarType())
+ return true;
+ if (const auto *RD = BaseElementType->getAsCXXRecordDecl())
+ return ::IsCXXReplaceableType(*this, RD);
+ return false;
+}
+
+static std::optional<TypeTrait> StdNameToTypeTrait(StringRef Name) {
+ return llvm::StringSwitch<std::optional<TypeTrait>>(Name)
+ .Case("is_trivially_relocatable",
+ TypeTrait::UTT_IsCppTriviallyRelocatable)
+ .Default(std::nullopt);
+}
+
+// Recognize type traits that are builting type traits, or known standard
+// type traits in <type_traits>. Note that at this point we assume the
+// trait evaluated to false, so we need only to recognize the shape of the
+// outer-most symbol.
+static std::optional<std::pair<TypeTrait, llvm::SmallVector<QualType, 1>>>
+ExtractTypeTraitFromExpression(const Expr *E) {
+ llvm::SmallVector<QualType, 1> Args;
+ std::optional<TypeTrait> Trait;
+
+ // builtins
+ if (const auto *TraitExpr = dyn_cast<TypeTraitExpr>(E)) {
+ Trait = TraitExpr->getTrait();
+ for (const auto *Arg : TraitExpr->getArgs())
+ Args.push_back(Arg->getType());
+ return {{Trait.value(), std::move(Args)}};
+ }
+ const auto *Ref = dyn_cast<DeclRefExpr>(E);
+ if (!Ref)
+ return std::nullopt;
+
+ // std::is_xxx_v<>
+ if (const auto *VD =
+ dyn_cast<VarTemplateSpecializationDecl>(Ref->getDecl())) {
+ if (!VD->isInStdNamespace())
+ return std::nullopt;
+ StringRef Name = VD->getIdentifier()->getName();
+ if (!Name.consume_back("_v"))
+ return std::nullopt;
+ Trait = StdNameToTypeTrait(Name);
+ if (!Trait)
+ return std::nullopt;
+ for (const auto &Arg : VD->getTemplateArgs().asArray())
+ Args.push_back(Arg.getAsType());
+ return {{Trait.value(), std::move(Args)}};
+ }
+
+ // std::is_xxx<>::value
+ if (const auto *VD = dyn_cast<VarDecl>(Ref->getDecl());
+ Ref->hasQualifier() && VD && VD->getIdentifier()->isStr("value")) {
+ const Type *T = Ref->getQualifier()->getAsType();
+ if (!T)
+ return std::nullopt;
+ const TemplateSpecializationType *Ts =
+ T->getAs<TemplateSpecializationType>();
+ if (!Ts)
+ return std::nullopt;
+ const TemplateDecl *D = Ts->getTemplateName().getAsTemplateDecl();
+ if (!D || !D->isInStdNamespace())
+ return std::nullopt;
+ Trait = StdNameToTypeTrait(D->getIdentifier()->getName());
+ if (!Trait)
+ return std::nullopt;
+ for (const auto &Arg : Ts->template_arguments())
+ Args.push_back(Arg.getAsType());
+ return {{Trait.value(), std::move(Args)}};
+ }
+ return std::nullopt;
+}
+
+static void DiagnoseNonTriviallyRelocatableReason(Sema &SemaRef,
+ SourceLocation Loc,
+ const CXXRecordDecl *D) {
+ for (const CXXBaseSpecifier &B : D->bases()) {
+ const auto *BaseDecl = B.getType()->getAsCXXRecordDecl();
+ if (!BaseDecl)
+ continue;
+ if (B.isVirtual())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::VBase << B.getType()
+ << B.getSourceRange();
+ if (!SemaRef.IsCXXTriviallyRelocatableType(B.getType()))
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::NRBase << B.getType()
+ << B.getSourceRange();
+ }
+ for (const FieldDecl *Field : D->fields()) {
+ if (Field->getType()->isReferenceType())
+ continue;
+ if (!SemaRef.IsCXXTriviallyRelocatableType(Field->getType()))
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::NRField << Field <<
Field->getType()
+ << Field->getSourceRange();
+ }
+ if (D->hasDeletedDestructor())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::DeletedDtr << /*Deleted*/ 0
+ << D->getDestructor()->getSourceRange();
+
+ if (D->hasAttr<TriviallyRelocatableAttr>())
+ return;
+
+ if (D->isUnion()) {
+ auto DiagSPM = [&](CXXSpecialMemberKind K, bool Has) {
+ if (Has)
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::UnionWithUserDeclaredSMF << K;
+ };
+ DiagSPM(CXXSpecialMemberKind::CopyConstructor,
+ D->hasUserDeclaredCopyConstructor());
+ DiagSPM(CXXSpecialMemberKind::CopyAssignment,
+ D->hasUserDeclaredCopyAssignment());
+ DiagSPM(CXXSpecialMemberKind::MoveConstructor,
+ D->hasUserDeclaredMoveConstructor());
+ DiagSPM(CXXSpecialMemberKind::MoveAssignment,
+ D->hasUserDeclaredMoveAssignment());
+ return;
+ }
+
+ if (!D->hasSimpleMoveConstructor() && !D->hasSimpleCopyConstructor()) {
+ const auto *Decl = cast<CXXConstructorDecl>(
+ LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/false));
+ if (Decl && Decl->isUserProvided())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::UserProvidedCtr
+ << Decl->isMoveConstructor() << Decl->getSourceRange();
+ }
+ if (!D->hasSimpleMoveAssignment() && !D->hasSimpleCopyAssignment()) {
+ CXXMethodDecl *Decl =
+ LookupSpecialMemberFromXValue(SemaRef, D, /*Assign=*/true);
+ if (Decl && Decl->isUserProvided())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::UserProvidedAssign
+ << Decl->isMoveAssignmentOperator() << Decl->getSourceRange();
+ }
+ CXXDestructorDecl *Dtr = D->getDestructor();
+ if (Dtr && Dtr->isUserProvided() && !Dtr->isDefaulted())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::DeletedDtr << /*User Provided*/ 1
+ << Dtr->getSourceRange();
+}
+
+static void DiagnoseNonTriviallyRelocatableReason(Sema &SemaRef,
+ SourceLocation Loc,
+ QualType T) {
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait)
+ << T << diag::TraitName::TriviallyRelocatable;
+ if (T->isVariablyModifiedType())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::VLA;
+
+ if (T->isReferenceType())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::Ref;
+ T = T.getNonReferenceType();
+
+ if (T.hasNonTrivialObjCLifetime())
+ SemaRef.Diag(Loc, diag::note_unsatisfied_trait_reason)
+ << diag::TraitNotSatisfiedReason::HasArcLifetime;
+
+ const CXXRecordDecl *D = T->getAsCXXRecordDecl();
+ if (!D)
+ return;
+
+ if (D->hasDefinition())
+ DiagnoseNonTriviallyRelocatableReason(SemaRef, Loc, D);
+
+ SemaRef.Diag(D->getLocation(), diag::note_defined_here) << D;
+}
+
+void Sema::DiagnoseTypeTraitDetails(const Expr *E) {
+ E = E->IgnoreParenImpCasts();
+ if (E->containsErrors())
+ return;
+
+ auto TraitInfo = ExtractTypeTraitFromExpression(E);
+ if (!TraitInfo)
+ return;
+
+ const auto &[Trait, Args] = TraitInfo.value();
+ switch (Trait) {
+ case UTT_IsCppTriviallyRelocatable:
+ DiagnoseNonTriviallyRelocatableReason(*this, E->getBeginLoc(), Args[0]);
+ break;
+ default:
+ break;
+ }
+}
diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
new file mode 100644
index 0000000000000..90cff1e66000c
--- /dev/null
+++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags-std.cpp
@@ -0,0 +1,101 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 -DSTD1 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 -DSTD2 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++20 -DSTD3 %s
+
+namespace std {
+
+#ifdef STD1
+template <typename T>
+struct is_trivially_relocatable {
+ static constexpr bool value = __builtin_is_cpp_trivially_relocatable(T);
+};
+
+template <typename T>
+constexpr bool is_trivially_relocatable_v =
__builtin_is_cpp_trivially_relocatable(T);
+#endif
+
+#ifdef STD2
+template <typename T>
+struct __details_is_trivially_relocatable {
+ static constexpr bool value = __builtin_is_cpp_trivially_relocatable(T);
+};
+
+template <typename T>
+using is_trivially_relocatable = __details_is_trivially_relocatable<T>;
+
+template <typename T>
+constexpr bool is_trivially_relocatable_v =
__builtin_is_cpp_trivially_relocatable(T);
+#endif
+
+
+#ifdef STD3
+template< class T, T v >
+struct integral_constant {
+ static constexpr T value = v;
+};
+
+template< bool B >
+using bool_constant = integral_constant<bool, B>;
+
+template <typename T>
+struct __details_is_trivially_relocatable :
bool_constant<__builtin_is_cpp_trivially_relocatable(T)> {};
+
+template <typename T>
+using is_trivially_relocatable = __details_is_trivially_relocatable<T>;
+
+template <typename T>
+constexpr bool is_trivially_relocatable_v = is_trivially_relocatable<T>::value;
+#endif
+
+}
+
+static_assert(std::is_trivially_relocatable<int>::value);
+
+static_assert(std::is_trivially_relocatable<int&>::value);
+// expected-error-re@-1 {{static assertion failed due to requirement
'std::{{.*}}is_trivially_relocatable<int &>::value'}} \
+// expected-note@-1 {{'int &' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a reference type}}
+static_assert(std::is_trivially_relocatable_v<int&>);
+// expected-error@-1 {{static assertion failed due to requirement
'std::is_trivially_relocatable_v<int &>'}} \
+// expected-note@-1 {{'int &' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a reference type}}
+
+namespace test_namespace {
+ using namespace std;
+ static_assert(is_trivially_relocatable<int&>::value);
+ // expected-error-re@-1 {{static assertion failed due to requirement
'{{.*}}is_trivially_relocatable<int &>::value'}} \
+ // expected-note@-1 {{'int &' is not trivially relocatable}} \
+ // expected-note@-1 {{because it is a reference type}}
+ static_assert(is_trivially_relocatable_v<int&>);
+ // expected-error@-1 {{static assertion failed due to requirement
'is_trivially_relocatable_v<int &>'}} \
+ // expected-note@-1 {{'int &' is not trivially relocatable}} \
+ // expected-note@-1 {{because it is a reference type}}
+}
+
+
+namespace concepts {
+template <typename T>
+requires std::is_trivially_relocatable<T>::value void f(); // #cand1
+
+template <typename T>
+concept C = std::is_trivially_relocatable_v<T>; // #concept2
+
+template <C T> void g(); // #cand2
+
+void test() {
+ f<int&>();
+ // expected-error@-1 {{no matching function for call to 'f'}} \
+ // expected-note@#cand1 {{candidate template ignored: constraints not
satisfied [with T = int &]}} \
+ // expected-note-re@#cand1 {{because '{{.*}}is_trivially_relocatable<int
&>::value' evaluated to false}} \
+ // expected-note@#cand1 {{'int &' is not trivially relocatable}} \
+ // expected-note@#cand1 {{because it is a reference type}}
+
+ g<int&>();
+ // expected-error@-1 {{no matching function for call to 'g'}} \
+ // expected-note@#cand2 {{candidate template ignored: constraints not
satisfied [with T = int &]}} \
+ // expected-note@#cand2 {{because 'int &' does not satisfy 'C'}} \
+ // expected-note@#concept2 {{because 'std::is_trivially_relocatable_v<int
&>' evaluated to false}} \
+ // expected-note@#concept2 {{'int &' is not trivially relocatable}} \
+ // expected-note@#concept2 {{because it is a reference type}}
+}
+}
diff --git a/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
new file mode 100644
index 0000000000000..d9cab20f4febd
--- /dev/null
+++ b/clang/test/SemaCXX/type-traits-unsatisfied-diags.cpp
@@ -0,0 +1,146 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wno-vla-cxx-extension
-Wno-c++26-extensions -std=c++20 %s
+
+struct S : A {}; // expected-error{{expected class name}}
+
+static_assert(__builtin_is_cpp_trivially_relocatable()); // expected-error
{{expected a type}}
+static_assert(__builtin_is_cpp_trivially_relocatable(0)); // expected-error
{{expected a type}}
+static_assert(__builtin_is_cpp_trivially_relocatable(S));
+static_assert(__builtin_is_cpp_trivially_relocatable(A)); //
expected-error{{unknown type name 'A'}}
+
+static_assert(__builtin_is_cpp_trivially_relocatable(int, int)); //
expected-error {{type trait requires 1 argument; have 2 arguments}}
+
+static_assert(__builtin_is_cpp_trivially_relocatable(int&));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(int &)'}} \
+// expected-note@-1 {{'int &' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a reference type}}
+
+
+static_assert(!__builtin_is_cpp_trivially_relocatable(int&));
+static_assert(!!__builtin_is_cpp_trivially_relocatable(int&));
+// expected-error@-1{{static assertion failed due to requirement
'!!__builtin_is_cpp_trivially_relocatable(int &)'}}
+static_assert(bool(__builtin_is_cpp_trivially_relocatable(int&)));
+// expected-error@-1{{static assertion failed due to requirement
'bool(__builtin_is_cpp_trivially_relocatable(int &))'}}
+
+static_assert(__builtin_is_cpp_trivially_relocatable(int&) &&
__builtin_is_cpp_trivially_relocatable(int&));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(int &)'}} \
+// expected-note@-1 {{'int &' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a reference type}}
+
+namespace concepts {
+template <typename T>
+requires __builtin_is_cpp_trivially_relocatable(T) void f(); // #cand1
+
+template <typename T>
+concept C = __builtin_is_cpp_trivially_relocatable(T); // #concept2
+
+template <C T> void g(); // #cand2
+
+void test() {
+ f<int&>();
+ // expected-error@-1 {{no matching function for call to 'f'}} \
+ // expected-note@#cand1 {{candidate template ignored: constraints not
satisfied [with T = int &]}} \
+ // expected-note@#cand1 {{because
'__builtin_is_cpp_trivially_relocatable(int &)' evaluated to false}} \
+ // expected-note@#cand1 {{'int &' is not trivially relocatable}} \
+ // expected-note@#cand1 {{because it is a reference type}}
+
+ g<int&>();
+ // expected-error@-1 {{no matching function for call to 'g'}} \
+ // expected-note@#cand2 {{candidate template ignored: constraints not
satisfied [with T = int &]}} \
+ // expected-note@#cand2 {{because 'int &' does not satisfy 'C'}} \
+ // expected-note@#concept2 {{because
'__builtin_is_cpp_trivially_relocatable(int &)' evaluated to false}} \
+ // expected-note@#concept2 {{'int &' is not trivially relocatable}} \
+ // expected-note@#concept2 {{because it is a reference type}}
+}
+}
+
+namespace trivially_relocatable {
+
+extern int vla_size;
+static_assert(__builtin_is_cpp_trivially_relocatable(int[vla_size]));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(int[vla_size])'}} \
+// expected-note@-1 {{'int[vla_size]' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a variably-modified type}}
+
+struct S; // expected-note {{forward declaration of
'trivially_relocatable::S'}}
+static_assert(__builtin_is_cpp_trivially_relocatable(S));
+// expected-error@-1 {{incomplete type 'S' used in type trait expression}}
+
+struct B {
+ virtual ~B();
+};
+struct S : virtual B { // #tr-S
+ S();
+ int & a;
+ const int ci;
+ B & b;
+ B c;
+ ~S();
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(S));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::S)'}} \
+// expected-note@-1 {{'S' is not trivially relocatable}} \
+// expected-note@-1 {{because it has a virtual base 'B'}} \
+// expected-note@-1 {{because it has a non-trivially-relocatable base 'B'}} \
+// expected-note@-1 {{because it has a non-trivially-relocatable member 'c' of
type 'B'}} \
+// expected-note@-1 {{because it has a user-provided destructor}}
+// expected-note@#tr-S {{'S' defined here}}
+
+struct S2 { // #tr-S2
+ S2(S2&&);
+ S2& operator=(const S2&);
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(S2));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::S2)'}} \
+// expected-note@-1 {{'S2' is not trivially relocatable}} \
+// expected-note@-1 {{because it has a user provided move constructor}} \
+// expected-note@-1 {{because it has a user provided copy assignment
operator}} \
+// expected-note@#tr-S2 {{'S2' defined here}}
+
+
+struct S3 { // #tr-S3
+ ~S3() = delete;
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(S3));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::S3)'}} \
+// expected-note@-1 {{'S3' is not trivially relocatable}} \
+// expected-note@-1 {{because it has a deleted destructor}} \
+// expected-note@#tr-S3 {{'S3' defined here}}
+
+
+union U { // #tr-U
+ U(const U&);
+ U(U&&);
+ U& operator=(const U&);
+ U& operator=(U&&);
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(U));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::U)'}} \
+// expected-note@-1 {{'U' is not trivially relocatable}} \
+// expected-note@-1 {{because it is a union with a user-declared copy
constructor}} \
+// expected-note@-1 {{because it is a union with a user-declared copy
assignment operator}} \
+// expected-note@-1 {{because it is a union with a user-declared move
constructor}} \
+// expected-note@-1 {{because it is a union with a user-declared move
assignment operator}}
+// expected-note@#tr-U {{'U' defined here}}
+struct S4 trivially_relocatable_if_eligible { // #tr-S4
+ ~S4();
+ B b;
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(S4));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::S4)'}} \
+// expected-note@-1 {{'S4' is not trivially relocatable}} \
+// expected-note@-1 {{because it has a non-trivially-relocatable member 'b' of
type 'B'}} \
+// expected-note@#tr-S4 {{'S4' defined here}}
+
+union U2 trivially_relocatable_if_eligible { // #tr-U2
+ U2(const U2&);
+ U2(U2&&);
+ B b;
+};
+static_assert(__builtin_is_cpp_trivially_relocatable(U2));
+// expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(trivially_relocatable::U2)'}} \
+// expected-note@-1 {{'U2' is not trivially relocatable}} \
+// expected-note@-1 {{because it has a deleted destructor}} \
+// expected-note@-1 {{because it has a non-trivially-relocatable member 'b' of
type 'B'}} \
+// expected-note@#tr-U2 {{'U2' defined here}}
+
+}
diff --git a/clang/test/SemaObjCXX/objc-weak-type-traits.mm
b/clang/test/SemaObjCXX/objc-weak-type-traits.mm
index e8f3e637ac272..91683c904d35d 100644
--- a/clang/test/SemaObjCXX/objc-weak-type-traits.mm
+++ b/clang/test/SemaObjCXX/objc-weak-type-traits.mm
@@ -1,5 +1,4 @@
// RUN: %clang_cc1 -fsyntax-only -fobjc-weak -fobjc-runtime-has-weak -verify
-std=c++11 %s -Wno-deprecated-builtins
-// expected-no-diagnostics
// Check the results of the various type-trait query functions on
// lifetime-qualified types in ObjC Weak.
@@ -217,3 +216,9 @@
TRAIT_IS_TRUE(__is_trivially_relocatable, HasStrong);
TRAIT_IS_FALSE(__is_trivially_relocatable, HasWeak);
TRAIT_IS_TRUE(__is_trivially_relocatable, HasUnsafeUnretained);
+
+
+static_assert(__builtin_is_cpp_trivially_relocatable(__weak id), "");
+//expected-error@-1 {{static assertion failed due to requirement
'__builtin_is_cpp_trivially_relocatable(__weak id)'}}\
+//expected-note@-1 {{'__weak id' is not trivially relocatable}}\
+//expected-note@-1 {{because it has an ARC lifetime qualifier}}
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