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| //===--- TypeTraits.cpp - clang-tidy---------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "TypeTraits.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
namespace clang {
namespace tidy {
namespace utils {
namespace type_traits {
namespace {
bool classHasTrivialCopyAndDestroy(QualType Type) {
auto *Record = Type->getAsCXXRecordDecl();
return Record && Record->hasDefinition() &&
!Record->hasNonTrivialCopyConstructor() &&
!Record->hasNonTrivialDestructor();
}
bool hasDeletedCopyConstructor(QualType Type) {
auto *Record = Type->getAsCXXRecordDecl();
if (!Record || !Record->hasDefinition())
return false;
for (const auto *Constructor : Record->ctors()) {
if (Constructor->isCopyConstructor() && Constructor->isDeleted())
return true;
}
return false;
}
} // namespace
llvm::Optional<bool> isExpensiveToCopy(QualType Type,
const ASTContext &Context) {
if (Type->isDependentType() || Type->isIncompleteType())
return llvm::None;
return !Type.isTriviallyCopyableType(Context) &&
!classHasTrivialCopyAndDestroy(Type) &&
!hasDeletedCopyConstructor(Type) &&
!Type->isObjCLifetimeType();
}
bool recordIsTriviallyDefaultConstructible(const RecordDecl &RecordDecl,
const ASTContext &Context) {
const auto *ClassDecl = dyn_cast<CXXRecordDecl>(&RecordDecl);
// Non-C++ records are always trivially constructible.
if (!ClassDecl)
return true;
// It is impossible to detemine whether an ill-formed decl is trivially
// constructible.
if (RecordDecl.isInvalidDecl())
return false;
// A class with a user-provided default constructor is not trivially
// constructible.
if (ClassDecl->hasUserProvidedDefaultConstructor())
return false;
// A polymorphic class is not trivially constructible
if (ClassDecl->isPolymorphic())
return false;
// A class is trivially constructible if it has a trivial default constructor.
if (ClassDecl->hasTrivialDefaultConstructor())
return true;
// If all its fields are trivially constructible and have no default
// initializers.
for (const FieldDecl *Field : ClassDecl->fields()) {
if (Field->hasInClassInitializer())
return false;
if (!isTriviallyDefaultConstructible(Field->getType(), Context))
return false;
}
// If all its direct bases are trivially constructible.
for (const CXXBaseSpecifier &Base : ClassDecl->bases()) {
if (!isTriviallyDefaultConstructible(Base.getType(), Context))
return false;
if (Base.isVirtual())
return false;
}
return true;
}
// Based on QualType::isTrivial.
bool isTriviallyDefaultConstructible(QualType Type, const ASTContext &Context) {
if (Type.isNull())
return false;
if (Type->isArrayType())
return isTriviallyDefaultConstructible(Context.getBaseElementType(Type),
Context);
// Return false for incomplete types after skipping any incomplete array
// types which are expressly allowed by the standard and thus our API.
if (Type->isIncompleteType())
return false;
if (Context.getLangOpts().ObjCAutoRefCount) {
switch (Type.getObjCLifetime()) {
case Qualifiers::OCL_ExplicitNone:
return true;
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Weak:
case Qualifiers::OCL_Autoreleasing:
return false;
case Qualifiers::OCL_None:
if (Type->isObjCLifetimeType())
return false;
break;
}
}
QualType CanonicalType = Type.getCanonicalType();
if (CanonicalType->isDependentType())
return false;
// As an extension, Clang treats vector types as Scalar types.
if (CanonicalType->isScalarType() || CanonicalType->isVectorType())
return true;
if (const auto *RT = CanonicalType->getAs<RecordType>()) {
return recordIsTriviallyDefaultConstructible(*RT->getDecl(), Context);
}
// No other types can match.
return false;
}
bool hasNonTrivialMoveConstructor(QualType Type) {
auto *Record = Type->getAsCXXRecordDecl();
return Record && Record->hasDefinition() &&
Record->hasNonTrivialMoveConstructor();
}
bool hasNonTrivialMoveAssignment(QualType Type) {
auto *Record = Type->getAsCXXRecordDecl();
return Record && Record->hasDefinition() &&
Record->hasNonTrivialMoveAssignment();
}
} // namespace type_traits
} // namespace utils
} // namespace tidy
} // namespace clang
|