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llvm-project/clang/lib/Sema/SemaExprCXX.cpp

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//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Implements semantic analysis for C++ expressions.
///
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "TreeTransform.h"
#include "TypeLocBuilder.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/ParsedTemplate.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaLambda.h"
#include "clang/Sema/TemplateDeduction.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ErrorHandling.h"
using namespace clang;
using namespace sema;
/// \brief Handle the result of the special case name lookup for inheriting
/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
/// constructor names in member using declarations, even if 'X' is not the
/// name of the corresponding type.
ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS,
SourceLocation NameLoc,
IdentifierInfo &Name) {
NestedNameSpecifier *NNS = SS.getScopeRep();
// Convert the nested-name-specifier into a type.
QualType Type;
switch (NNS->getKind()) {
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
Type = QualType(NNS->getAsType(), 0);
break;
case NestedNameSpecifier::Identifier:
// Strip off the last layer of the nested-name-specifier and build a
// typename type for it.
assert(NNS->getAsIdentifier() == &Name && "not a constructor name");
Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
NNS->getAsIdentifier());
break;
case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
llvm_unreachable("Nested name specifier is not a type for inheriting ctor");
}
// This reference to the type is located entirely at the location of the
// final identifier in the qualified-id.
return CreateParsedType(Type,
Context.getTrivialTypeSourceInfo(Type, NameLoc));
}
ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
IdentifierInfo &II,
SourceLocation NameLoc,
Scope *S, CXXScopeSpec &SS,
ParsedType ObjectTypePtr,
bool EnteringContext) {
// Determine where to perform name lookup.
// FIXME: This area of the standard is very messy, and the current
// wording is rather unclear about which scopes we search for the
// destructor name; see core issues 399 and 555. Issue 399 in
// particular shows where the current description of destructor name
// lookup is completely out of line with existing practice, e.g.,
// this appears to be ill-formed:
//
// namespace N {
// template <typename T> struct S {
// ~S();
// };
// }
//
// void f(N::S<int>* s) {
// s->N::S<int>::~S();
// }
//
// See also PR6358 and PR6359.
// For this reason, we're currently only doing the C++03 version of this
// code; the C++0x version has to wait until we get a proper spec.
QualType SearchType;
DeclContext *LookupCtx = nullptr;
bool isDependent = false;
bool LookInScope = false;
if (SS.isInvalid())
return nullptr;
// If we have an object type, it's because we are in a
// pseudo-destructor-expression or a member access expression, and
// we know what type we're looking for.
if (ObjectTypePtr)
SearchType = GetTypeFromParser(ObjectTypePtr);
if (SS.isSet()) {
NestedNameSpecifier *NNS = SS.getScopeRep();
bool AlreadySearched = false;
bool LookAtPrefix = true;
// C++11 [basic.lookup.qual]p6:
// If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier,
// the type-names are looked up as types in the scope designated by the
// nested-name-specifier. Similarly, in a qualified-id of the form:
//
// nested-name-specifier[opt] class-name :: ~ class-name
//
// the second class-name is looked up in the same scope as the first.
//
// Here, we determine whether the code below is permitted to look at the
// prefix of the nested-name-specifier.
DeclContext *DC = computeDeclContext(SS, EnteringContext);
if (DC && DC->isFileContext()) {
AlreadySearched = true;
LookupCtx = DC;
isDependent = false;
} else if (DC && isa<CXXRecordDecl>(DC)) {
LookAtPrefix = false;
LookInScope = true;
}
// The second case from the C++03 rules quoted further above.
NestedNameSpecifier *Prefix = nullptr;
if (AlreadySearched) {
// Nothing left to do.
} else if (LookAtPrefix && (Prefix = NNS->getPrefix())) {
CXXScopeSpec PrefixSS;
PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
LookupCtx = computeDeclContext(PrefixSS, EnteringContext);
isDependent = isDependentScopeSpecifier(PrefixSS);
} else if (ObjectTypePtr) {
LookupCtx = computeDeclContext(SearchType);
isDependent = SearchType->isDependentType();
} else {
LookupCtx = computeDeclContext(SS, EnteringContext);
isDependent = LookupCtx && LookupCtx->isDependentContext();
}
} else if (ObjectTypePtr) {
// C++ [basic.lookup.classref]p3:
// If the unqualified-id is ~type-name, the type-name is looked up
// in the context of the entire postfix-expression. If the type T
// of the object expression is of a class type C, the type-name is
// also looked up in the scope of class C. At least one of the
// lookups shall find a name that refers to (possibly
// cv-qualified) T.
LookupCtx = computeDeclContext(SearchType);
isDependent = SearchType->isDependentType();
assert((isDependent || !SearchType->isIncompleteType()) &&
"Caller should have completed object type");
LookInScope = true;
} else {
// Perform lookup into the current scope (only).
LookInScope = true;
}
TypeDecl *NonMatchingTypeDecl = nullptr;
LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName);
for (unsigned Step = 0; Step != 2; ++Step) {
// Look for the name first in the computed lookup context (if we
// have one) and, if that fails to find a match, in the scope (if
// we're allowed to look there).
Found.clear();
if (Step == 0 && LookupCtx)
LookupQualifiedName(Found, LookupCtx);
else if (Step == 1 && LookInScope && S)
LookupName(Found, S);
else
continue;
// FIXME: Should we be suppressing ambiguities here?
if (Found.isAmbiguous())
return nullptr;
if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
QualType T = Context.getTypeDeclType(Type);
MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
if (SearchType.isNull() || SearchType->isDependentType() ||
Context.hasSameUnqualifiedType(T, SearchType)) {
// We found our type!
return CreateParsedType(T,
Context.getTrivialTypeSourceInfo(T, NameLoc));
}
if (!SearchType.isNull())
NonMatchingTypeDecl = Type;
}
// If the name that we found is a class template name, and it is
// the same name as the template name in the last part of the
// nested-name-specifier (if present) or the object type, then
// this is the destructor for that class.
// FIXME: This is a workaround until we get real drafting for core
// issue 399, for which there isn't even an obvious direction.
if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) {
QualType MemberOfType;
if (SS.isSet()) {
if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) {
// Figure out the type of the context, if it has one.
if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx))
MemberOfType = Context.getTypeDeclType(Record);
}
}
if (MemberOfType.isNull())
MemberOfType = SearchType;
if (MemberOfType.isNull())
continue;
// We're referring into a class template specialization. If the
// class template we found is the same as the template being
// specialized, we found what we are looking for.
if (const RecordType *Record = MemberOfType->getAs<RecordType>()) {
if (ClassTemplateSpecializationDecl *Spec
= dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
if (Spec->getSpecializedTemplate()->getCanonicalDecl() ==
Template->getCanonicalDecl())
return CreateParsedType(
MemberOfType,
Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
}
continue;
}
// We're referring to an unresolved class template
// specialization. Determine whether we class template we found
// is the same as the template being specialized or, if we don't
// know which template is being specialized, that it at least
// has the same name.
if (const TemplateSpecializationType *SpecType
= MemberOfType->getAs<TemplateSpecializationType>()) {
TemplateName SpecName = SpecType->getTemplateName();
// The class template we found is the same template being
// specialized.
if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) {
if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl())
return CreateParsedType(
MemberOfType,
Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
continue;
}
// The class template we found has the same name as the
// (dependent) template name being specialized.
if (DependentTemplateName *DepTemplate
= SpecName.getAsDependentTemplateName()) {
if (DepTemplate->isIdentifier() &&
DepTemplate->getIdentifier() == Template->getIdentifier())
return CreateParsedType(
MemberOfType,
Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc));
continue;
}
}
}
}
if (isDependent) {
// We didn't find our type, but that's okay: it's dependent
// anyway.
// FIXME: What if we have no nested-name-specifier?
QualType T = CheckTypenameType(ETK_None, SourceLocation(),
SS.getWithLocInContext(Context),
II, NameLoc);
return ParsedType::make(T);
}
if (NonMatchingTypeDecl) {
QualType T = Context.getTypeDeclType(NonMatchingTypeDecl);
Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
<< T << SearchType;
Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here)
<< T;
} else if (ObjectTypePtr)
Diag(NameLoc, diag::err_ident_in_dtor_not_a_type)
<< &II;
else {
SemaDiagnosticBuilder DtorDiag = Diag(NameLoc,
diag::err_destructor_class_name);
if (S) {
const DeclContext *Ctx = S->getEntity();
if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx))
DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc),
Class->getNameAsString());
}
}
return nullptr;
}
ParsedType Sema::getDestructorType(const DeclSpec& DS, ParsedType ObjectType) {
if (DS.getTypeSpecType() == DeclSpec::TST_error || !ObjectType)
return nullptr;
assert(DS.getTypeSpecType() == DeclSpec::TST_decltype
&& "only get destructor types from declspecs");
QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
QualType SearchType = GetTypeFromParser(ObjectType);
if (SearchType->isDependentType() || Context.hasSameUnqualifiedType(SearchType, T)) {
return ParsedType::make(T);
}
Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
<< T << SearchType;
return nullptr;
}
bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
const UnqualifiedId &Name) {
assert(Name.getKind() == UnqualifiedId::IK_LiteralOperatorId);
if (!SS.isValid())
return false;
switch (SS.getScopeRep()->getKind()) {
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
// Per C++11 [over.literal]p2, literal operators can only be declared at
// namespace scope. Therefore, this unqualified-id cannot name anything.
// Reject it early, because we have no AST representation for this in the
// case where the scope is dependent.
Diag(Name.getLocStart(), diag::err_literal_operator_id_outside_namespace)
<< SS.getScopeRep();
return true;
case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
return false;
}
llvm_unreachable("unknown nested name specifier kind");
}
/// \brief Build a C++ typeid expression with a type operand.
ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
SourceLocation TypeidLoc,
TypeSourceInfo *Operand,
SourceLocation RParenLoc) {
// C++ [expr.typeid]p4:
// The top-level cv-qualifiers of the lvalue expression or the type-id
// that is the operand of typeid are always ignored.
// If the type of the type-id is a class type or a reference to a class
// type, the class shall be completely-defined.
Qualifiers Quals;
QualType T
= Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
Quals);
if (T->getAs<RecordType>() &&
RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
return ExprError();
if (T->isVariablyModifiedType())
return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);
return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
SourceRange(TypeidLoc, RParenLoc));
}
/// \brief Build a C++ typeid expression with an expression operand.
ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
SourceLocation TypeidLoc,
Expr *E,
SourceLocation RParenLoc) {
bool WasEvaluated = false;
if (E && !E->isTypeDependent()) {
if (E->getType()->isPlaceholderType()) {
ExprResult result = CheckPlaceholderExpr(E);
if (result.isInvalid()) return ExprError();
E = result.get();
}
QualType T = E->getType();
if (const RecordType *RecordT = T->getAs<RecordType>()) {
CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
// C++ [expr.typeid]p3:
// [...] If the type of the expression is a class type, the class
// shall be completely-defined.
if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
return ExprError();
// C++ [expr.typeid]p3:
// When typeid is applied to an expression other than an glvalue of a
// polymorphic class type [...] [the] expression is an unevaluated
// operand. [...]
if (RecordD->isPolymorphic() && E->isGLValue()) {
// The subexpression is potentially evaluated; switch the context
// and recheck the subexpression.
ExprResult Result = TransformToPotentiallyEvaluated(E);
if (Result.isInvalid()) return ExprError();
E = Result.get();
// We require a vtable to query the type at run time.
MarkVTableUsed(TypeidLoc, RecordD);
WasEvaluated = true;
}
}
// C++ [expr.typeid]p4:
// [...] If the type of the type-id is a reference to a possibly
// cv-qualified type, the result of the typeid expression refers to a
// std::type_info object representing the cv-unqualified referenced
// type.
Qualifiers Quals;
QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
if (!Context.hasSameType(T, UnqualT)) {
T = UnqualT;
E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
}
}
if (E->getType()->isVariablyModifiedType())
return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
<< E->getType());
else if (ActiveTemplateInstantiations.empty() &&
E->HasSideEffects(Context, WasEvaluated)) {
// The expression operand for typeid is in an unevaluated expression
// context, so side effects could result in unintended consequences.
Diag(E->getExprLoc(), WasEvaluated
? diag::warn_side_effects_typeid
: diag::warn_side_effects_unevaluated_context);
}
return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
SourceRange(TypeidLoc, RParenLoc));
}
/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
ExprResult
Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
// Find the std::type_info type.
if (!getStdNamespace())
return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
if (!CXXTypeInfoDecl) {
IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
LookupQualifiedName(R, getStdNamespace());
CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
// Microsoft's typeinfo doesn't have type_info in std but in the global
// namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
LookupQualifiedName(R, Context.getTranslationUnitDecl());
CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
}
if (!CXXTypeInfoDecl)
return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
}
if (!getLangOpts().RTTI) {
return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
}
QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);
if (isType) {
// The operand is a type; handle it as such.
TypeSourceInfo *TInfo = nullptr;
QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
&TInfo);
if (T.isNull())
return ExprError();
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
}
// The operand is an expression.
return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
}
/// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
/// a single GUID.
static void
getUuidAttrOfType(Sema &SemaRef, QualType QT,
llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) {
// Optionally remove one level of pointer, reference or array indirection.
const Type *Ty = QT.getTypePtr();
if (QT->isPointerType() || QT->isReferenceType())
Ty = QT->getPointeeType().getTypePtr();
else if (QT->isArrayType())
Ty = Ty->getBaseElementTypeUnsafe();
const auto *RD = Ty->getAsCXXRecordDecl();
if (!RD)
return;
if (const auto *Uuid = RD->getMostRecentDecl()->getAttr<UuidAttr>()) {
UuidAttrs.insert(Uuid);
return;
}
// __uuidof can grab UUIDs from template arguments.
if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
for (const TemplateArgument &TA : TAL.asArray()) {
const UuidAttr *UuidForTA = nullptr;
if (TA.getKind() == TemplateArgument::Type)
getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
else if (TA.getKind() == TemplateArgument::Declaration)
getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);
if (UuidForTA)
UuidAttrs.insert(UuidForTA);
}
}
}
/// \brief Build a Microsoft __uuidof expression with a type operand.
ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
SourceLocation TypeidLoc,
TypeSourceInfo *Operand,
SourceLocation RParenLoc) {
StringRef UuidStr;
if (!Operand->getType()->isDependentType()) {
llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
if (UuidAttrs.empty())
return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
if (UuidAttrs.size() > 1)
return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
UuidStr = UuidAttrs.back()->getGuid();
}
return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, UuidStr,
SourceRange(TypeidLoc, RParenLoc));
}
/// \brief Build a Microsoft __uuidof expression with an expression operand.
ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType,
SourceLocation TypeidLoc,
Expr *E,
SourceLocation RParenLoc) {
StringRef UuidStr;
if (!E->getType()->isDependentType()) {
if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
UuidStr = "00000000-0000-0000-0000-000000000000";
} else {
llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
getUuidAttrOfType(*this, E->getType(), UuidAttrs);
if (UuidAttrs.empty())
return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
if (UuidAttrs.size() > 1)
return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
UuidStr = UuidAttrs.back()->getGuid();
}
}
return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, UuidStr,
SourceRange(TypeidLoc, RParenLoc));
}
/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
ExprResult
Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
// If MSVCGuidDecl has not been cached, do the lookup.
if (!MSVCGuidDecl) {
IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID");
LookupResult R(*this, GuidII, SourceLocation(), LookupTagName);
LookupQualifiedName(R, Context.getTranslationUnitDecl());
MSVCGuidDecl = R.getAsSingle<RecordDecl>();
if (!MSVCGuidDecl)
return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof));
}
QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl);
if (isType) {
// The operand is a type; handle it as such.
TypeSourceInfo *TInfo = nullptr;
QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
&TInfo);
if (T.isNull())
return ExprError();
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);
return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
}
// The operand is an expression.
return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
}
/// ActOnCXXBoolLiteral - Parse {true,false} literals.
ExprResult
Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
"Unknown C++ Boolean value!");
return new (Context)
CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
}
/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
ExprResult
Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
}
/// ActOnCXXThrow - Parse throw expressions.
ExprResult
Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
bool IsThrownVarInScope = false;
if (Ex) {
// C++0x [class.copymove]p31:
// When certain criteria are met, an implementation is allowed to omit the
// copy/move construction of a class object [...]
//
// - in a throw-expression, when the operand is the name of a
// non-volatile automatic object (other than a function or catch-
// clause parameter) whose scope does not extend beyond the end of the
// innermost enclosing try-block (if there is one), the copy/move
// operation from the operand to the exception object (15.1) can be
// omitted by constructing the automatic object directly into the
// exception object
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
for( ; S; S = S->getParent()) {
if (S->isDeclScope(Var)) {
IsThrownVarInScope = true;
break;
}
if (S->getFlags() &
(Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
Scope::TryScope))
break;
}
}
}
}
return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
}
ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
bool IsThrownVarInScope) {
// Don't report an error if 'throw' is used in system headers.
if (!getLangOpts().CXXExceptions &&
!getSourceManager().isInSystemHeader(OpLoc))
Diag(OpLoc, diag::err_exceptions_disabled) << "throw";
if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";
if (Ex && !Ex->isTypeDependent()) {
QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
return ExprError();
// Initialize the exception result. This implicitly weeds out
// abstract types or types with inaccessible copy constructors.
// C++0x [class.copymove]p31:
// When certain criteria are met, an implementation is allowed to omit the
// copy/move construction of a class object [...]
//
// - in a throw-expression, when the operand is the name of a
// non-volatile automatic object (other than a function or
// catch-clause
// parameter) whose scope does not extend beyond the end of the
// innermost enclosing try-block (if there is one), the copy/move
// operation from the operand to the exception object (15.1) can be
// omitted by constructing the automatic object directly into the
// exception object
const VarDecl *NRVOVariable = nullptr;
if (IsThrownVarInScope)
NRVOVariable = getCopyElisionCandidate(QualType(), Ex, false);
InitializedEntity Entity = InitializedEntity::InitializeException(
OpLoc, ExceptionObjectTy,
/*NRVO=*/NRVOVariable != nullptr);
ExprResult Res = PerformMoveOrCopyInitialization(
Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope);
if (Res.isInvalid())
return ExprError();
Ex = Res.get();
}
return new (Context)
CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
}
static void
collectPublicBases(CXXRecordDecl *RD,
llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
bool ParentIsPublic) {
for (const CXXBaseSpecifier &BS : RD->bases()) {
CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
bool NewSubobject;
// Virtual bases constitute the same subobject. Non-virtual bases are
// always distinct subobjects.
if (BS.isVirtual())
NewSubobject = VBases.insert(BaseDecl).second;
else
NewSubobject = true;
if (NewSubobject)
++SubobjectsSeen[BaseDecl];
// Only add subobjects which have public access throughout the entire chain.
bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
if (PublicPath)
PublicSubobjectsSeen.insert(BaseDecl);
// Recurse on to each base subobject.
collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
PublicPath);
}
}
static void getUnambiguousPublicSubobjects(
CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) {
llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
llvm::SmallSet<CXXRecordDecl *, 2> VBases;
llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
SubobjectsSeen[RD] = 1;
PublicSubobjectsSeen.insert(RD);
collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
/*ParentIsPublic=*/true);
for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
// Skip ambiguous objects.
if (SubobjectsSeen[PublicSubobject] > 1)
continue;
Objects.push_back(PublicSubobject);
}
}
/// CheckCXXThrowOperand - Validate the operand of a throw.
bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
QualType ExceptionObjectTy, Expr *E) {
// If the type of the exception would be an incomplete type or a pointer
// to an incomplete type other than (cv) void the program is ill-formed.
QualType Ty = ExceptionObjectTy;
bool isPointer = false;
if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
Ty = Ptr->getPointeeType();
isPointer = true;
}
if (!isPointer || !Ty->isVoidType()) {
if (RequireCompleteType(ThrowLoc, Ty,
isPointer ? diag::err_throw_incomplete_ptr
: diag::err_throw_incomplete,
E->getSourceRange()))
return true;
if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
diag::err_throw_abstract_type, E))
return true;
}
// If the exception has class type, we need additional handling.
CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
if (!RD)
return false;
// If we are throwing a polymorphic class type or pointer thereof,
// exception handling will make use of the vtable.
MarkVTableUsed(ThrowLoc, RD);
// If a pointer is thrown, the referenced object will not be destroyed.
if (isPointer)
return false;
// If the class has a destructor, we must be able to call it.
if (!RD->hasIrrelevantDestructor()) {
if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
MarkFunctionReferenced(E->getExprLoc(), Destructor);
CheckDestructorAccess(E->getExprLoc(), Destructor,
PDiag(diag::err_access_dtor_exception) << Ty);
if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
return true;
}
}
// The MSVC ABI creates a list of all types which can catch the exception
// object. This list also references the appropriate copy constructor to call
// if the object is caught by value and has a non-trivial copy constructor.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
// We are only interested in the public, unambiguous bases contained within
// the exception object. Bases which are ambiguous or otherwise
// inaccessible are not catchable types.
llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);
for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
// Attempt to lookup the copy constructor. Various pieces of machinery
// will spring into action, like template instantiation, which means this
// cannot be a simple walk of the class's decls. Instead, we must perform
// lookup and overload resolution.
CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
if (!CD)
continue;
// Mark the constructor referenced as it is used by this throw expression.
MarkFunctionReferenced(E->getExprLoc(), CD);
// Skip this copy constructor if it is trivial, we don't need to record it
// in the catchable type data.
if (CD->isTrivial())
continue;
// The copy constructor is non-trivial, create a mapping from this class
// type to this constructor.
// N.B. The selection of copy constructor is not sensitive to this
// particular throw-site. Lookup will be performed at the catch-site to
// ensure that the copy constructor is, in fact, accessible (via
// friendship or any other means).
Context.addCopyConstructorForExceptionObject(Subobject, CD);
// We don't keep the instantiated default argument expressions around so
// we must rebuild them here.
for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
// Skip any default arguments that we've already instantiated.
if (Context.getDefaultArgExprForConstructor(CD, I))
continue;
Expr *DefaultArg =
BuildCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)).get();
Context.addDefaultArgExprForConstructor(CD, I, DefaultArg);
}
}
}
return false;
}
QualType Sema::getCurrentThisType() {
DeclContext *DC = getFunctionLevelDeclContext();
QualType ThisTy = CXXThisTypeOverride;
if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
if (method && method->isInstance())
ThisTy = method->getThisType(Context);
}
if (ThisTy.isNull()) {
if (isGenericLambdaCallOperatorSpecialization(CurContext) &&
CurContext->getParent()->getParent()->isRecord()) {
// This is a generic lambda call operator that is being instantiated
// within a default initializer - so use the enclosing class as 'this'.
// There is no enclosing member function to retrieve the 'this' pointer
// from.
// FIXME: This looks wrong. If we're in a lambda within a lambda within a
// default member initializer, we need to recurse up more parents to find
// the right context. Looks like we should be walking up to the parent of
// the closure type, checking whether that is itself a lambda, and if so,
// recursing, until we reach a class or a function that isn't a lambda
// call operator. And we should accumulate the constness of *this on the
// way.
QualType ClassTy = Context.getTypeDeclType(
cast<CXXRecordDecl>(CurContext->getParent()->getParent()));
// There are no cv-qualifiers for 'this' within default initializers,
// per [expr.prim.general]p4.
ThisTy = Context.getPointerType(ClassTy);
}
}
// Add const for '* this' capture if not mutable.
if (isLambdaCallOperator(CurContext)) {
LambdaScopeInfo *LSI = getCurLambda();
assert(LSI);
if (LSI->isCXXThisCaptured()) {
auto C = LSI->getCXXThisCapture();
QualType BaseType = ThisTy->getPointeeType();
if ((C.isThisCapture() && C.isCopyCapture()) &&
LSI->CallOperator->isConst() && !BaseType.isConstQualified()) {
BaseType.addConst();
ThisTy = Context.getPointerType(BaseType);
}
}
}
return ThisTy;
}
Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
Decl *ContextDecl,
unsigned CXXThisTypeQuals,
bool Enabled)
: S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
{
if (!Enabled || !ContextDecl)
return;
CXXRecordDecl *Record = nullptr;
if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
Record = Template->getTemplatedDecl();
else
Record = cast<CXXRecordDecl>(ContextDecl);
S.CXXThisTypeOverride
= S.Context.getPointerType(
S.Context.getRecordType(Record).withCVRQualifiers(CXXThisTypeQuals));
this->Enabled = true;
}
Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
if (Enabled) {
S.CXXThisTypeOverride = OldCXXThisTypeOverride;
}
}
static Expr *captureThis(Sema &S, ASTContext &Context, RecordDecl *RD,
QualType ThisTy, SourceLocation Loc,
const bool ByCopy) {
QualType CaptureThisTy = ByCopy ? ThisTy->getPointeeType() : ThisTy;
FieldDecl *Field
= FieldDecl::Create(Context, RD, Loc, Loc, nullptr, CaptureThisTy,
Context.getTrivialTypeSourceInfo(CaptureThisTy, Loc),
nullptr, false, ICIS_NoInit);
Field->setImplicit(true);
Field->setAccess(AS_private);
RD->addDecl(Field);
Expr *This = new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit*/true);
if (ByCopy) {
Expr *StarThis = S.CreateBuiltinUnaryOp(Loc,
UO_Deref,
This).get();
InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture(
nullptr, CaptureThisTy, Loc);
InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
InitializationSequence Init(S, Entity, InitKind, StarThis);
ExprResult ER = Init.Perform(S, Entity, InitKind, StarThis);
if (ER.isInvalid()) return nullptr;
return ER.get();
}
return This;
}
bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
const bool ByCopy) {
// We don't need to capture this in an unevaluated context.
if (isUnevaluatedContext() && !Explicit)
return true;
assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value");
const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ?
*FunctionScopeIndexToStopAt : FunctionScopes.size() - 1;
// Check that we can capture the *enclosing object* (referred to by '*this')
// by the capturing-entity/closure (lambda/block/etc) at
// MaxFunctionScopesIndex-deep on the FunctionScopes stack.
// Note: The *enclosing object* can only be captured by-value by a
// closure that is a lambda, using the explicit notation:
// [*this] { ... }.
// Every other capture of the *enclosing object* results in its by-reference
// capture.
// For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes
// stack), we can capture the *enclosing object* only if:
// - 'L' has an explicit byref or byval capture of the *enclosing object*
// - or, 'L' has an implicit capture.
// AND
// -- there is no enclosing closure
// -- or, there is some enclosing closure 'E' that has already captured the
// *enclosing object*, and every intervening closure (if any) between 'E'
// and 'L' can implicitly capture the *enclosing object*.
// -- or, every enclosing closure can implicitly capture the
// *enclosing object*
unsigned NumCapturingClosures = 0;
for (unsigned idx = MaxFunctionScopesIndex; idx != 0; idx--) {
if (CapturingScopeInfo *CSI =
dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {
if (CSI->CXXThisCaptureIndex != 0) {
// 'this' is already being captured; there isn't anything more to do.
break;
}
LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
// This context can't implicitly capture 'this'; fail out.
if (BuildAndDiagnose)
Diag(Loc, diag::err_this_capture)
<< (Explicit && idx == MaxFunctionScopesIndex);
return true;
}
if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||
CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||
CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||
(Explicit && idx == MaxFunctionScopesIndex)) {
// Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first
// iteration through can be an explicit capture, all enclosing closures,
// if any, must perform implicit captures.
// This closure can capture 'this'; continue looking upwards.
NumCapturingClosures++;
continue;
}
// This context can't implicitly capture 'this'; fail out.
if (BuildAndDiagnose)
Diag(Loc, diag::err_this_capture)
<< (Explicit && idx == MaxFunctionScopesIndex);
return true;
}
break;
}
if (!BuildAndDiagnose) return false;
// If we got here, then the closure at MaxFunctionScopesIndex on the
// FunctionScopes stack, can capture the *enclosing object*, so capture it
// (including implicit by-reference captures in any enclosing closures).
// In the loop below, respect the ByCopy flag only for the closure requesting
// the capture (i.e. first iteration through the loop below). Ignore it for
// all enclosing closure's upto NumCapturingClosures (since they must be
// implicitly capturing the *enclosing object* by reference (see loop
// above)).
assert((!ByCopy ||
dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&
"Only a lambda can capture the enclosing object (referred to by "
"*this) by copy");
// FIXME: We need to delay this marking in PotentiallyPotentiallyEvaluated
// contexts.
for (unsigned idx = MaxFunctionScopesIndex; NumCapturingClosures;
--idx, --NumCapturingClosures) {
CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]);
Expr *ThisExpr = nullptr;
QualType ThisTy = getCurrentThisType();
if (LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI)) {
// For lambda expressions, build a field and an initializing expression,
// and capture the *enclosing object* by copy only if this is the first
// iteration.
ThisExpr = captureThis(*this, Context, LSI->Lambda, ThisTy, Loc,
ByCopy && idx == MaxFunctionScopesIndex);
} else if (CapturedRegionScopeInfo *RSI
= dyn_cast<CapturedRegionScopeInfo>(FunctionScopes[idx]))
ThisExpr =
captureThis(*this, Context, RSI->TheRecordDecl, ThisTy, Loc,
false/*ByCopy*/);
bool isNested = NumCapturingClosures > 1;
CSI->addThisCapture(isNested, Loc, ThisTy, ThisExpr, ByCopy);
}
return false;
}
ExprResult Sema::ActOnCXXThis(SourceLocation Loc) {
/// C++ 9.3.2: In the body of a non-static member function, the keyword this
/// is a non-lvalue expression whose value is the address of the object for
/// which the function is called.
QualType ThisTy = getCurrentThisType();
if (ThisTy.isNull()) return Diag(Loc, diag::err_invalid_this_use);
CheckCXXThisCapture(Loc);
return new (Context) CXXThisExpr(Loc, ThisTy, /*isImplicit=*/false);
}
bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) {
// If we're outside the body of a member function, then we'll have a specified
// type for 'this'.
if (CXXThisTypeOverride.isNull())
return false;
// Determine whether we're looking into a class that's currently being
// defined.
CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl();
return Class && Class->isBeingDefined();
}
ExprResult
Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep,
SourceLocation LParenLoc,
MultiExprArg exprs,
SourceLocation RParenLoc) {
if (!TypeRep)
return ExprError();
TypeSourceInfo *TInfo;
QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());
return BuildCXXTypeConstructExpr(TInfo, LParenLoc, exprs, RParenLoc);
}
/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
ExprResult
Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
SourceLocation LParenLoc,
MultiExprArg Exprs,
SourceLocation RParenLoc) {
QualType Ty = TInfo->getType();
SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc();
if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) {
return CXXUnresolvedConstructExpr::Create(Context, TInfo, LParenLoc, Exprs,
RParenLoc);
}
bool ListInitialization = LParenLoc.isInvalid();
assert((!ListInitialization || (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0])))
&& "List initialization must have initializer list as expression.");
SourceRange FullRange = SourceRange(TyBeginLoc,
ListInitialization ? Exprs[0]->getSourceRange().getEnd() : RParenLoc);
// C++ [expr.type.conv]p1:
// If the expression list is a single expression, the type conversion
// expression is equivalent (in definedness, and if defined in meaning) to the
// corresponding cast expression.
if (Exprs.size() == 1 && !ListInitialization) {
Expr *Arg = Exprs[0];
return BuildCXXFunctionalCastExpr(TInfo, LParenLoc, Arg, RParenLoc);
}
// C++14 [expr.type.conv]p2: The expression T(), where T is a
// simple-type-specifier or typename-specifier for a non-array complete
// object type or the (possibly cv-qualified) void type, creates a prvalue
// of the specified type, whose value is that produced by value-initializing
// an object of type T.
QualType ElemTy = Ty;
if (Ty->isArrayType()) {
if (!ListInitialization)
return ExprError(Diag(TyBeginLoc,
diag::err_value_init_for_array_type) << FullRange);
ElemTy = Context.getBaseElementType(Ty);
}
if (!ListInitialization && Ty->isFunctionType())
return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_function_type)
<< FullRange);
if (!Ty->isVoidType() &&
RequireCompleteType(TyBeginLoc, ElemTy,
diag::err_invalid_incomplete_type_use, FullRange))
return ExprError();
if (RequireNonAbstractType(TyBeginLoc, Ty,
diag::err_allocation_of_abstract_type))
return ExprError();
InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo);
InitializationKind Kind =
Exprs.size() ? ListInitialization
? InitializationKind::CreateDirectList(TyBeginLoc)
: InitializationKind::CreateDirect(TyBeginLoc, LParenLoc, RParenLoc)
: InitializationKind::CreateValue(TyBeginLoc, LParenLoc, RParenLoc);
InitializationSequence InitSeq(*this, Entity, Kind, Exprs);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs);
if (Result.isInvalid() || !ListInitialization)
return Result;
Expr *Inner = Result.get();
if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner))
Inner = BTE->getSubExpr();
if (!isa<CXXTemporaryObjectExpr>(Inner)) {
// If we created a CXXTemporaryObjectExpr, that node also represents the
// functional cast. Otherwise, create an explicit cast to represent
// the syntactic form of a functional-style cast that was used here.
//
// FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr
// would give a more consistent AST representation than using a
// CXXTemporaryObjectExpr. It's also weird that the functional cast
// is sometimes handled by initialization and sometimes not.
QualType ResultType = Result.get()->getType();
Result = CXXFunctionalCastExpr::Create(
Context, ResultType, Expr::getValueKindForType(TInfo->getType()), TInfo,
CK_NoOp, Result.get(), /*Path=*/nullptr, LParenLoc, RParenLoc);
}
return Result;
}
/// doesUsualArrayDeleteWantSize - Answers whether the usual
/// operator delete[] for the given type has a size_t parameter.
static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc,
QualType allocType) {
const RecordType *record =
allocType->getBaseElementTypeUnsafe()->getAs<RecordType>();
if (!record) return false;
// Try to find an operator delete[] in class scope.
DeclarationName deleteName =
S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName);
S.LookupQualifiedName(ops, record->getDecl());
// We're just doing this for information.
ops.suppressDiagnostics();
// Very likely: there's no operator delete[].
if (ops.empty()) return false;
// If it's ambiguous, it should be illegal to call operator delete[]
// on this thing, so it doesn't matter if we allocate extra space or not.
if (ops.isAmbiguous()) return false;
LookupResult::Filter filter = ops.makeFilter();
while (filter.hasNext()) {
NamedDecl *del = filter.next()->getUnderlyingDecl();
// C++0x [basic.stc.dynamic.deallocation]p2:
// A template instance is never a usual deallocation function,
// regardless of its signature.
if (isa<FunctionTemplateDecl>(del)) {
filter.erase();
continue;
}
// C++0x [basic.stc.dynamic.deallocation]p2:
// If class T does not declare [an operator delete[] with one
// parameter] but does declare a member deallocation function
// named operator delete[] with exactly two parameters, the
// second of which has type std::size_t, then this function
// is a usual deallocation function.
if (!cast<CXXMethodDecl>(del)->isUsualDeallocationFunction()) {
filter.erase();
continue;
}
}
filter.done();
if (!ops.isSingleResult()) return false;
const FunctionDecl *del = cast<FunctionDecl>(ops.getFoundDecl());
return (del->getNumParams() == 2);
}
/// \brief Parsed a C++ 'new' expression (C++ 5.3.4).
///
/// E.g.:
/// @code new (memory) int[size][4] @endcode
/// or
/// @code ::new Foo(23, "hello") @endcode
///
/// \param StartLoc The first location of the expression.
/// \param UseGlobal True if 'new' was prefixed with '::'.
/// \param PlacementLParen Opening paren of the placement arguments.
/// \param PlacementArgs Placement new arguments.
/// \param PlacementRParen Closing paren of the placement arguments.
/// \param TypeIdParens If the type is in parens, the source range.
/// \param D The type to be allocated, as well as array dimensions.
/// \param Initializer The initializing expression or initializer-list, or null
/// if there is none.
ExprResult
Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
SourceLocation PlacementRParen, SourceRange TypeIdParens,
Declarator &D, Expr *Initializer) {
bool TypeContainsAuto = D.getDeclSpec().containsPlaceholderType();
Expr *ArraySize = nullptr;
// If the specified type is an array, unwrap it and save the expression.
if (D.getNumTypeObjects() > 0 &&
D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
DeclaratorChunk &Chunk = D.getTypeObject(0);
if (TypeContainsAuto)
return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto)
<< D.getSourceRange());
if (Chunk.Arr.hasStatic)
return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
<< D.getSourceRange());
if (!Chunk.Arr.NumElts)
return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
<< D.getSourceRange());
ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
D.DropFirstTypeObject();
}
// Every dimension shall be of constant size.
if (ArraySize) {
for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
break;
DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
if (Expr *NumElts = (Expr *)Array.NumElts) {
if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) {
if (getLangOpts().CPlusPlus14) {
// C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator
// shall be a converted constant expression (5.19) of type std::size_t
// and shall evaluate to a strictly positive value.
unsigned IntWidth = Context.getTargetInfo().getIntWidth();
assert(IntWidth && "Builtin type of size 0?");
llvm::APSInt Value(IntWidth);
Array.NumElts
= CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value,
CCEK_NewExpr)
.get();
} else {
Array.NumElts
= VerifyIntegerConstantExpression(NumElts, nullptr,
diag::err_new_array_nonconst)
.get();
}
if (!Array.NumElts)
return ExprError();
}
}
}
}
TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr);
QualType AllocType = TInfo->getType();
if (D.isInvalidType())
return ExprError();
SourceRange DirectInitRange;
if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer))
DirectInitRange = List->getSourceRange();
return BuildCXXNew(SourceRange(StartLoc, D.getLocEnd()), UseGlobal,
PlacementLParen,
PlacementArgs,
PlacementRParen,
TypeIdParens,
AllocType,
TInfo,
ArraySize,
DirectInitRange,
Initializer,
TypeContainsAuto);
}
static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style,
Expr *Init) {
if (!Init)
return true;
if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init))
return PLE->getNumExprs() == 0;
if (isa<ImplicitValueInitExpr>(Init))
return true;
else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init))
return !CCE->isListInitialization() &&
CCE->getConstructor()->isDefaultConstructor();
else if (Style == CXXNewExpr::ListInit) {
assert(isa<InitListExpr>(Init) &&
"Shouldn't create list CXXConstructExprs for arrays.");
return true;
}
return false;
}
ExprResult
Sema::BuildCXXNew(SourceRange Range, bool UseGlobal,
SourceLocation PlacementLParen,
MultiExprArg PlacementArgs,
SourceLocation PlacementRParen,
SourceRange TypeIdParens,
QualType AllocType,
TypeSourceInfo *AllocTypeInfo,
Expr *ArraySize,
SourceRange DirectInitRange,
Expr *Initializer,
bool TypeMayContainAuto) {
SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange();
SourceLocation StartLoc = Range.getBegin();
CXXNewExpr::InitializationStyle initStyle;
if (DirectInitRange.isValid()) {
assert(Initializer && "Have parens but no initializer.");
initStyle = CXXNewExpr::CallInit;
} else if (Initializer && isa<InitListExpr>(Initializer))
initStyle = CXXNewExpr::ListInit;
else {
assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||
isa<CXXConstructExpr>(Initializer)) &&
"Initializer expression that cannot have been implicitly created.");
initStyle = CXXNewExpr::NoInit;
}
Expr **Inits = &Initializer;
unsigned NumInits = Initializer ? 1 : 0;
if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) {
assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init");
Inits = List->getExprs();
NumInits = List->getNumExprs();
}
// C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for.
if (TypeMayContainAuto && AllocType->isUndeducedType()) {
if (initStyle == CXXNewExpr::NoInit || NumInits == 0)
return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg)
<< AllocType << TypeRange);
if (initStyle == CXXNewExpr::ListInit ||
(NumInits == 1 && isa<InitListExpr>(Inits[0])))
return ExprError(Diag(Inits[0]->getLocStart(),
diag::err_auto_new_list_init)
<< AllocType << TypeRange);
if (NumInits > 1) {
Expr *FirstBad = Inits[1];
return ExprError(Diag(FirstBad->getLocStart(),
diag::err_auto_new_ctor_multiple_expressions)
<< AllocType << TypeRange);
}
Expr *Deduce = Inits[0];
QualType DeducedType;
if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed)
return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure)
<< AllocType << Deduce->getType()
<< TypeRange << Deduce->getSourceRange());
if (DeducedType.isNull())
return ExprError();
AllocType = DeducedType;
}
// Per C++0x [expr.new]p5, the type being constructed may be a
// typedef of an array type.
if (!ArraySize) {
if (const ConstantArrayType *Array
= Context.getAsConstantArrayType(AllocType)) {
ArraySize = IntegerLiteral::Create(Context, Array->getSize(),
Context.getSizeType(),
TypeRange.getEnd());
AllocType = Array->getElementType();
}
}
if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange))
return ExprError();
if (initStyle == CXXNewExpr::ListInit &&
isStdInitializerList(AllocType, nullptr)) {
Diag(AllocTypeInfo->getTypeLoc().getBeginLoc(),
diag::warn_dangling_std_initializer_list)
<< /*at end of FE*/0 << Inits[0]->getSourceRange();
}
// In ARC, infer 'retaining' for the allocated
if (getLangOpts().ObjCAutoRefCount &&
AllocType.getObjCLifetime() == Qualifiers::OCL_None &&
AllocType->isObjCLifetimeType()) {
AllocType = Context.getLifetimeQualifiedType(AllocType,
AllocType->getObjCARCImplicitLifetime());
}
QualType ResultType = Context.getPointerType(AllocType);
if (ArraySize && ArraySize->getType()->isNonOverloadPlaceholderType()) {
ExprResult result = CheckPlaceholderExpr(ArraySize);
if (result.isInvalid()) return ExprError();
ArraySize = result.get();
}
// C++98 5.3.4p6: "The expression in a direct-new-declarator shall have
// integral or enumeration type with a non-negative value."
// C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped
// enumeration type, or a class type for which a single non-explicit
// conversion function to integral or unscoped enumeration type exists.
// C++1y [expr.new]p6: The expression [...] is implicitly converted to
// std::size_t.
if (ArraySize && !ArraySize->isTypeDependent()) {
ExprResult ConvertedSize;
if (getLangOpts().CPlusPlus14) {
assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?");
ConvertedSize = PerformImplicitConversion(ArraySize, Context.getSizeType(),
AA_Converting);
if (!ConvertedSize.isInvalid() &&
ArraySize->getType()->getAs<RecordType>())
// Diagnose the compatibility of this conversion.
Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion)
<< ArraySize->getType() << 0 << "'size_t'";
} else {
class SizeConvertDiagnoser : public ICEConvertDiagnoser {
protected:
Expr *ArraySize;
public:
SizeConvertDiagnoser(Expr *ArraySize)
: ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false),
ArraySize(ArraySize) {}
SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
QualType T) override {
return S.Diag(Loc, diag::err_array_size_not_integral)
<< S.getLangOpts().CPlusPlus11 << T;
}
SemaDiagnosticBuilder diagnoseIncomplete(
Sema &S, SourceLocation Loc, QualType T) override {
return S.Diag(Loc, diag::err_array_size_incomplete_type)
<< T << ArraySize->getSourceRange();
}
SemaDiagnosticBuilder diagnoseExplicitConv(
Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override {
return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy;
}
SemaDiagnosticBuilder noteExplicitConv(
Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
<< ConvTy->isEnumeralType() << ConvTy;
}
SemaDiagnosticBuilder diagnoseAmbiguous(
Sema &S, SourceLocation Loc, QualType T) override {
return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T;
}
SemaDiagnosticBuilder noteAmbiguous(
Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override {
return S.Diag(Conv->getLocation(), diag::note_array_size_conversion)
<< ConvTy->isEnumeralType() << ConvTy;
}
SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
QualType T,
QualType ConvTy) override {
return S.Diag(Loc,
S.getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_array_size_conversion
: diag::ext_array_size_conversion)
<< T << ConvTy->isEnumeralType() << ConvTy;
}
} SizeDiagnoser(ArraySize);
ConvertedSize = PerformContextualImplicitConversion(StartLoc, ArraySize,
SizeDiagnoser);
}
if (ConvertedSize.isInvalid())
return ExprError();
ArraySize = ConvertedSize.get();
QualType SizeType = ArraySize->getType();
if (!SizeType->isIntegralOrUnscopedEnumerationType())
return ExprError();
// C++98 [expr.new]p7:
// The expression in a direct-new-declarator shall have integral type
// with a non-negative value.
//
// Let's see if this is a constant < 0. If so, we reject it out of
// hand. Otherwise, if it's not a constant, we must have an unparenthesized
// array type.
//
// Note: such a construct has well-defined semantics in C++11: it throws
// std::bad_array_new_length.
if (!ArraySize->isValueDependent()) {
llvm::APSInt Value;
// We've already performed any required implicit conversion to integer or
// unscoped enumeration type.
if (ArraySize->isIntegerConstantExpr(Value, Context)) {
if (Value < llvm::APSInt(
llvm::APInt::getNullValue(Value.getBitWidth()),
Value.isUnsigned())) {
if (getLangOpts().CPlusPlus11)
Diag(ArraySize->getLocStart(),
diag::warn_typecheck_negative_array_new_size)
<< ArraySize->getSourceRange();
else
return ExprError(Diag(ArraySize->getLocStart(),
diag::err_typecheck_negative_array_size)
<< ArraySize->getSourceRange());
} else if (!AllocType->isDependentType()) {
unsigned ActiveSizeBits =
ConstantArrayType::getNumAddressingBits(Context, AllocType, Value);
if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
if (getLangOpts().CPlusPlus11)
Diag(ArraySize->getLocStart(),
diag::warn_array_new_too_large)
<< Value.toString(10)
<< ArraySize->getSourceRange();
else
return ExprError(Diag(ArraySize->getLocStart(),
diag::err_array_too_large)
<< Value.toString(10)
<< ArraySize->getSourceRange());
}
}
} else if (TypeIdParens.isValid()) {
// Can't have dynamic array size when the type-id is in parentheses.
Diag(ArraySize->getLocStart(), diag::ext_new_paren_array_nonconst)
<< ArraySize->getSourceRange()
<< FixItHint::CreateRemoval(TypeIdParens.getBegin())
<< FixItHint::CreateRemoval(TypeIdParens.getEnd());
TypeIdParens = SourceRange();
}
}
// Note that we do *not* convert the argument in any way. It can
// be signed, larger than size_t, whatever.
}
FunctionDecl *OperatorNew = nullptr;
FunctionDecl *OperatorDelete = nullptr;
if (!AllocType->isDependentType() &&
!Expr::hasAnyTypeDependentArguments(PlacementArgs) &&
FindAllocationFunctions(StartLoc,
SourceRange(PlacementLParen, PlacementRParen),
UseGlobal, AllocType, ArraySize, PlacementArgs,
OperatorNew, OperatorDelete))
return ExprError();
// If this is an array allocation, compute whether the usual array
// deallocation function for the type has a size_t parameter.
bool UsualArrayDeleteWantsSize = false;
if (ArraySize && !AllocType->isDependentType())
UsualArrayDeleteWantsSize
= doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType);
SmallVector<Expr *, 8> AllPlaceArgs;
if (OperatorNew) {
const FunctionProtoType *Proto =
OperatorNew->getType()->getAs<FunctionProtoType>();
VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction
: VariadicDoesNotApply;
// We've already converted the placement args, just fill in any default
// arguments. Skip the first parameter because we don't have a corresponding
// argument.
if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 1,
PlacementArgs, AllPlaceArgs, CallType))
return ExprError();
if (!AllPlaceArgs.empty())
PlacementArgs = AllPlaceArgs;
// FIXME: This is wrong: PlacementArgs misses out the first (size) argument.
DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs);
// FIXME: Missing call to CheckFunctionCall or equivalent
}
// Warn if the type is over-aligned and is being allocated by global operator
// new.
if (PlacementArgs.empty() && OperatorNew &&
(OperatorNew->isImplicit() ||
(OperatorNew->getLocStart().isValid() &&
getSourceManager().isInSystemHeader(OperatorNew->getLocStart())))) {
if (unsigned Align = Context.getPreferredTypeAlign(AllocType.getTypePtr())){
unsigned SuitableAlign = Context.getTargetInfo().getSuitableAlign();
if (Align > SuitableAlign)
Diag(StartLoc, diag::warn_overaligned_type)
<< AllocType
<< unsigned(Align / Context.getCharWidth())
<< unsigned(SuitableAlign / Context.getCharWidth());
}
}
QualType InitType = AllocType;
// Array 'new' can't have any initializers except empty parentheses.
// Initializer lists are also allowed, in C++11. Rely on the parser for the
// dialect distinction.
if (ResultType->isArrayType() || ArraySize) {
if (!isLegalArrayNewInitializer(initStyle, Initializer)) {
SourceRange InitRange(Inits[0]->getLocStart(),
Inits[NumInits - 1]->getLocEnd());
Diag(StartLoc, diag::err_new_array_init_args) << InitRange;
return ExprError();
}
if (InitListExpr *ILE = dyn_cast_or_null<InitListExpr>(Initializer)) {
// We do the initialization typechecking against the array type
// corresponding to the number of initializers + 1 (to also check
// default-initialization).
unsigned NumElements = ILE->getNumInits() + 1;
InitType = Context.getConstantArrayType(AllocType,
llvm::APInt(Context.getTypeSize(Context.getSizeType()), NumElements),
ArrayType::Normal, 0);
}
}
// If we can perform the initialization, and we've not already done so,
// do it now.
if (!AllocType->isDependentType() &&
!Expr::hasAnyTypeDependentArguments(
llvm::makeArrayRef(Inits, NumInits))) {
// C++11 [expr.new]p15:
// A new-expression that creates an object of type T initializes that
// object as follows:
InitializationKind Kind
// - If the new-initializer is omitted, the object is default-
// initialized (8.5); if no initialization is performed,
// the object has indeterminate value
= initStyle == CXXNewExpr::NoInit
? InitializationKind::CreateDefault(TypeRange.getBegin())
// - Otherwise, the new-initializer is interpreted according to the
// initialization rules of 8.5 for direct-initialization.
: initStyle == CXXNewExpr::ListInit
? InitializationKind::CreateDirectList(TypeRange.getBegin())
: InitializationKind::CreateDirect(TypeRange.getBegin(),
DirectInitRange.getBegin(),
DirectInitRange.getEnd());
InitializedEntity Entity
= InitializedEntity::InitializeNew(StartLoc, InitType);
InitializationSequence InitSeq(*this, Entity, Kind, MultiExprArg(Inits, NumInits));
ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind,
MultiExprArg(Inits, NumInits));
if (FullInit.isInvalid())
return ExprError();
// FullInit is our initializer; strip off CXXBindTemporaryExprs, because
// we don't want the initialized object to be destructed.
if (CXXBindTemporaryExpr *Binder =
dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get()))
FullInit = Binder->getSubExpr();
Initializer = FullInit.get();
}
// Mark the new and delete operators as referenced.
if (OperatorNew) {
if (DiagnoseUseOfDecl(OperatorNew, StartLoc))
return ExprError();
MarkFunctionReferenced(StartLoc, OperatorNew);
}
if (OperatorDelete) {
if (DiagnoseUseOfDecl(OperatorDelete, StartLoc))
return ExprError();
MarkFunctionReferenced(StartLoc, OperatorDelete);
}
// C++0x [expr.new]p17:
// If the new expression creates an array of objects of class type,
// access and ambiguity control are done for the destructor.
QualType BaseAllocType = Context.getBaseElementType(AllocType);
if (ArraySize && !BaseAllocType->isDependentType()) {
if (const RecordType *BaseRecordType = BaseAllocType->getAs<RecordType>()) {
if (CXXDestructorDecl *dtor = LookupDestructor(
cast<CXXRecordDecl>(BaseRecordType->getDecl()))) {
MarkFunctionReferenced(StartLoc, dtor);
CheckDestructorAccess(StartLoc, dtor,
PDiag(diag::err_access_dtor)
<< BaseAllocType);
if (DiagnoseUseOfDecl(dtor, StartLoc))
return ExprError();
}
}
}
return new (Context)
CXXNewExpr(Context, UseGlobal, OperatorNew, OperatorDelete,
UsualArrayDeleteWantsSize, PlacementArgs, TypeIdParens,
ArraySize, initStyle, Initializer, ResultType, AllocTypeInfo,
Range, DirectInitRange);
}
/// \brief Checks that a type is suitable as the allocated type
/// in a new-expression.
bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
SourceRange R) {
// C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
// abstract class type or array thereof.
if (AllocType->isFunctionType())
return Diag(Loc, diag::err_bad_new_type)
<< AllocType << 0 << R;
else if (AllocType->isReferenceType())
return Diag(Loc, diag::err_bad_new_type)
<< AllocType << 1 << R;
else if (!AllocType->isDependentType() &&
RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R))
return true;
else if (RequireNonAbstractType(Loc, AllocType,
diag::err_allocation_of_abstract_type))
return true;
else if (AllocType->isVariablyModifiedType())
return Diag(Loc, diag::err_variably_modified_new_type)
<< AllocType;
else if (unsigned AddressSpace = AllocType.getAddressSpace())
return Diag(Loc, diag::err_address_space_qualified_new)
<< AllocType.getUnqualifiedType() << AddressSpace;
else if (getLangOpts().ObjCAutoRefCount) {
if (const ArrayType *AT = Context.getAsArrayType(AllocType)) {
QualType BaseAllocType = Context.getBaseElementType(AT);
if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None &&
BaseAllocType->isObjCLifetimeType())
return Diag(Loc, diag::err_arc_new_array_without_ownership)
<< BaseAllocType;
}
}
return false;
}
/// \brief Determine whether the given function is a non-placement
/// deallocation function.
static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) {
if (FD->isInvalidDecl())
return false;
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
return Method->isUsualDeallocationFunction();
if (FD->getOverloadedOperator() != OO_Delete &&
FD->getOverloadedOperator() != OO_Array_Delete)
return false;
if (FD->getNumParams() == 1)
return true;
return S.getLangOpts().SizedDeallocation && FD->getNumParams() == 2 &&
S.Context.hasSameUnqualifiedType(FD->getParamDecl(1)->getType(),
S.Context.getSizeType());
}
/// FindAllocationFunctions - Finds the overloads of operator new and delete
/// that are appropriate for the allocation.
bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
bool UseGlobal, QualType AllocType,
bool IsArray, MultiExprArg PlaceArgs,
FunctionDecl *&OperatorNew,
FunctionDecl *&OperatorDelete) {
// --- Choosing an allocation function ---
// C++ 5.3.4p8 - 14 & 18
// 1) If UseGlobal is true, only look in the global scope. Else, also look
// in the scope of the allocated class.
// 2) If an array size is given, look for operator new[], else look for
// operator new.
// 3) The first argument is always size_t. Append the arguments from the
// placement form.
SmallVector<Expr*, 8> AllocArgs(1 + PlaceArgs.size());
// We don't care about the actual value of this argument.
// FIXME: Should the Sema create the expression and embed it in the syntax
// tree? Or should the consumer just recalculate the value?
IntegerLiteral Size(Context, llvm::APInt::getNullValue(
Context.getTargetInfo().getPointerWidth(0)),
Context.getSizeType(),
SourceLocation());
AllocArgs[0] = &Size;
std::copy(PlaceArgs.begin(), PlaceArgs.end(), AllocArgs.begin() + 1);
// C++ [expr.new]p8:
// If the allocated type is a non-array type, the allocation
// function's name is operator new and the deallocation function's
// name is operator delete. If the allocated type is an array
// type, the allocation function's name is operator new[] and the
// deallocation function's name is operator delete[].
DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
IsArray ? OO_Array_New : OO_New);
DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
IsArray ? OO_Array_Delete : OO_Delete);
QualType AllocElemType = Context.getBaseElementType(AllocType);
if (AllocElemType->isRecordType() && !UseGlobal) {
CXXRecordDecl *Record
= cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, Record,
/*AllowMissing=*/true, OperatorNew))
return true;
}
if (!OperatorNew) {
// Didn't find a member overload. Look for a global one.
DeclareGlobalNewDelete();
DeclContext *TUDecl = Context.getTranslationUnitDecl();
bool FallbackEnabled = IsArray && Context.getLangOpts().MSVCCompat;
if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
/*AllowMissing=*/FallbackEnabled, OperatorNew,
/*Diagnose=*/!FallbackEnabled)) {
if (!FallbackEnabled)
return true;
// MSVC will fall back on trying to find a matching global operator new
// if operator new[] cannot be found. Also, MSVC will leak by not
// generating a call to operator delete or operator delete[], but we
// will not replicate that bug.
NewName = Context.DeclarationNames.getCXXOperatorName(OO_New);
DeleteName = Context.DeclarationNames.getCXXOperatorName(OO_Delete);
if (FindAllocationOverload(StartLoc, Range, NewName, AllocArgs, TUDecl,
/*AllowMissing=*/false, OperatorNew))
return true;
}
}
// We don't need an operator delete if we're running under
// -fno-exceptions.
if (!getLangOpts().Exceptions) {
OperatorDelete = nullptr;
return false;
}
// C++ [expr.new]p19:
//
// If the new-expression begins with a unary :: operator, the
// deallocation function's name is looked up in the global
// scope. Otherwise, if the allocated type is a class type T or an
// array thereof, the deallocation function's name is looked up in
// the scope of T. If this lookup fails to find the name, or if
// the allocated type is not a class type or array thereof, the
// deallocation function's name is looked up in the global scope.
LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName);
if (AllocElemType->isRecordType() && !UseGlobal) {
CXXRecordDecl *RD
= cast<CXXRecordDecl>(AllocElemType->getAs<RecordType>()->getDecl());
LookupQualifiedName(FoundDelete, RD);
}
if (FoundDelete.isAmbiguous())
return true; // FIXME: clean up expressions?
if (FoundDelete.empty()) {
DeclareGlobalNewDelete();
LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
}
FoundDelete.suppressDiagnostics();
SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches;
// Whether we're looking for a placement operator delete is dictated
// by whether we selected a placement operator new, not by whether
// we had explicit placement arguments. This matters for things like
// struct A { void *operator new(size_t, int = 0); ... };
// A *a = new A()
bool isPlacementNew = (!PlaceArgs.empty() || OperatorNew->param_size() != 1);
if (isPlacementNew) {
// C++ [expr.new]p20:
// A declaration of a placement deallocation function matches the
// declaration of a placement allocation function if it has the
// same number of parameters and, after parameter transformations
// (8.3.5), all parameter types except the first are
// identical. [...]
//
// To perform this comparison, we compute the function type that
// the deallocation function should have, and use that type both
// for template argument deduction and for comparison purposes.
//
// FIXME: this comparison should ignore CC and the like.
QualType ExpectedFunctionType;
{
const FunctionProtoType *Proto
= OperatorNew->getType()->getAs<FunctionProtoType>();
SmallVector<QualType, 4> ArgTypes;
ArgTypes.push_back(Context.VoidPtrTy);
for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I)
ArgTypes.push_back(Proto->getParamType(I));
FunctionProtoType::ExtProtoInfo EPI;
EPI.Variadic = Proto->isVariadic();
ExpectedFunctionType
= Context.getFunctionType(Context.VoidTy, ArgTypes, EPI);
}
for (LookupResult::iterator D = FoundDelete.begin(),
DEnd = FoundDelete.end();
D != DEnd; ++D) {
FunctionDecl *Fn = nullptr;
if (FunctionTemplateDecl *FnTmpl
= dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) {
// Perform template argument deduction to try to match the
// expected function type.
TemplateDeductionInfo Info(StartLoc);
if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn,
Info))
continue;
} else
Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl());
if (Context.hasSameType(Fn->getType(), ExpectedFunctionType))
Matches.push_back(std::make_pair(D.getPair(), Fn));
}
} else {
// C++ [expr.new]p20:
// [...] Any non-placement deallocation function matches a
// non-placement allocation function. [...]
for (LookupResult::iterator D = FoundDelete.begin(),
DEnd = FoundDelete.end();
D != DEnd; ++D) {
if (FunctionDecl *Fn = dyn_cast<FunctionDecl>((*D)->getUnderlyingDecl()))
if (isNonPlacementDeallocationFunction(*this, Fn))
Matches.push_back(std::make_pair(D.getPair(), Fn));
}
// C++1y [expr.new]p22:
// For a non-placement allocation function, the normal deallocation
// function lookup is used
// C++1y [expr.delete]p?:
// If [...] deallocation function lookup finds both a usual deallocation
// function with only a pointer parameter and a usual deallocation
// function with both a pointer parameter and a size parameter, then the
// selected deallocation function shall be the one with two parameters.
// Otherwise, the selected deallocation function shall be the function
// with one parameter.
if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
if (Matches[0].second->getNumParams() == 1)
Matches.erase(Matches.begin());
else
Matches.erase(Matches.begin() + 1);
assert(Matches[0].second->getNumParams() == 2 &&
"found an unexpected usual deallocation function");
}
}
// C++ [expr.new]p20:
// [...] If the lookup finds a single matching deallocation
// function, that function will be called; otherwise, no
// deallocation function will be called.
if (Matches.size() == 1) {
OperatorDelete = Matches[0].second;
// C++0x [expr.new]p20:
// If the lookup finds the two-parameter form of a usual
// deallocation function (3.7.4.2) and that function, considered
// as a placement deallocation function, would have been
// selected as a match for the allocation function, the program
// is ill-formed.
if (!PlaceArgs.empty() && getLangOpts().CPlusPlus11 &&
isNonPlacementDeallocationFunction(*this, OperatorDelete)) {
Diag(StartLoc, diag::err_placement_new_non_placement_delete)
<< SourceRange(PlaceArgs.front()->getLocStart(),
PlaceArgs.back()->getLocEnd());
if (!OperatorDelete->isImplicit())
Diag(OperatorDelete->getLocation(), diag::note_previous_decl)
<< DeleteName;
} else {
CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(),
Matches[0].first);
}
}
return false;
}
/// \brief Find an fitting overload for the allocation function
/// in the specified scope.
///
/// \param StartLoc The location of the 'new' token.
/// \param Range The range of the placement arguments.
/// \param Name The name of the function ('operator new' or 'operator new[]').
/// \param Args The placement arguments specified.
/// \param Ctx The scope in which we should search; either a class scope or the
/// translation unit.
/// \param AllowMissing If \c true, report an error if we can't find any
/// allocation functions. Otherwise, succeed but don't fill in \p
/// Operator.
/// \param Operator Filled in with the found allocation function. Unchanged if
/// no allocation function was found.
/// \param Diagnose If \c true, issue errors if the allocation function is not
/// usable.
bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
DeclarationName Name, MultiExprArg Args,
DeclContext *Ctx,
bool AllowMissing, FunctionDecl *&Operator,
bool Diagnose) {
LookupResult R(*this, Name, StartLoc, LookupOrdinaryName);
LookupQualifiedName(R, Ctx);
if (R.empty()) {
if (AllowMissing || !Diagnose)
return false;
return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
<< Name << Range;
}
if (R.isAmbiguous())
return true;
R.suppressDiagnostics();
OverloadCandidateSet Candidates(StartLoc, OverloadCandidateSet::CSK_Normal);
for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end();
Alloc != AllocEnd; ++Alloc) {
// Even member operator new/delete are implicitly treated as
// static, so don't use AddMemberCandidate.
NamedDecl *D = (*Alloc)->getUnderlyingDecl();
if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) {
AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(),
/*ExplicitTemplateArgs=*/nullptr,
Args, Candidates,
/*SuppressUserConversions=*/false);
continue;
}
FunctionDecl *Fn = cast<FunctionDecl>(D);
AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates,
/*SuppressUserConversions=*/false);
}
// Do the resolution.
OverloadCandidateSet::iterator Best;
switch (Candidates.BestViableFunction(*this, StartLoc, Best)) {
case OR_Success: {
// Got one!
FunctionDecl *FnDecl = Best->Function;
if (CheckAllocationAccess(StartLoc, Range, R.getNamingClass(),
Best->FoundDecl, Diagnose) == AR_inaccessible)
return true;
Operator = FnDecl;
return false;
}
case OR_No_Viable_Function:
if (Diagnose) {
Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
<< Name << Range;
Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
}
return true;
case OR_Ambiguous:
if (Diagnose) {
Diag(StartLoc, diag::err_ovl_ambiguous_call)
<< Name << Range;
Candidates.NoteCandidates(*this, OCD_ViableCandidates, Args);
}
return true;
case OR_Deleted: {
if (Diagnose) {
Diag(StartLoc, diag::err_ovl_deleted_call)
<< Best->Function->isDeleted()
<< Name
<< getDeletedOrUnavailableSuffix(Best->Function)
<< Range;
Candidates.NoteCandidates(*this, OCD_AllCandidates, Args);
}
return true;
}
}
llvm_unreachable("Unreachable, bad result from BestViableFunction");
}
/// DeclareGlobalNewDelete - Declare the global forms of operator new and
/// delete. These are:
/// @code
/// // C++03:
/// void* operator new(std::size_t) throw(std::bad_alloc);
/// void* operator new[](std::size_t) throw(std::bad_alloc);
/// void operator delete(void *) throw();
/// void operator delete[](void *) throw();
/// // C++11:
/// void* operator new(std::size_t);
/// void* operator new[](std::size_t);
/// void operator delete(void *) noexcept;
/// void operator delete[](void *) noexcept;
/// // C++1y:
/// void* operator new(std::size_t);
/// void* operator new[](std::size_t);
/// void operator delete(void *) noexcept;
/// void operator delete[](void *) noexcept;
/// void operator delete(void *, std::size_t) noexcept;
/// void operator delete[](void *, std::size_t) noexcept;
/// @endcode
/// Note that the placement and nothrow forms of new are *not* implicitly
/// declared. Their use requires including \<new\>.
void Sema::DeclareGlobalNewDelete() {
if (GlobalNewDeleteDeclared)
return;
// C++ [basic.std.dynamic]p2:
// [...] The following allocation and deallocation functions (18.4) are
// implicitly declared in global scope in each translation unit of a
// program
//
// C++03:
// void* operator new(std::size_t) throw(std::bad_alloc);
// void* operator new[](std::size_t) throw(std::bad_alloc);
// void operator delete(void*) throw();
// void operator delete[](void*) throw();
// C++11:
// void* operator new(std::size_t);
// void* operator new[](std::size_t);
// void operator delete(void*) noexcept;
// void operator delete[](void*) noexcept;
// C++1y:
// void* operator new(std::size_t);
// void* operator new[](std::size_t);
// void operator delete(void*) noexcept;
// void operator delete[](void*) noexcept;
// void operator delete(void*, std::size_t) noexcept;
// void operator delete[](void*, std::size_t) noexcept;
//
// These implicit declarations introduce only the function names operator
// new, operator new[], operator delete, operator delete[].
//
// Here, we need to refer to std::bad_alloc, so we will implicitly declare
// "std" or "bad_alloc" as necessary to form the exception specification.
// However, we do not make these implicit declarations visible to name
// lookup.
if (!StdBadAlloc && !getLangOpts().CPlusPlus11) {
// The "std::bad_alloc" class has not yet been declared, so build it
// implicitly.
StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class,
getOrCreateStdNamespace(),
SourceLocation(), SourceLocation(),
&PP.getIdentifierTable().get("bad_alloc"),
nullptr);
getStdBadAlloc()->setImplicit(true);
}
GlobalNewDeleteDeclared = true;
QualType VoidPtr = Context.getPointerType(Context.VoidTy);
QualType SizeT = Context.getSizeType();
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_New),
VoidPtr, SizeT, QualType());
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
VoidPtr, SizeT, QualType());
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_Delete),
Context.VoidTy, VoidPtr);
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
Context.VoidTy, VoidPtr);
if (getLangOpts().SizedDeallocation) {
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_Delete),
Context.VoidTy, VoidPtr, Context.getSizeType());
DeclareGlobalAllocationFunction(
Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
Context.VoidTy, VoidPtr, Context.getSizeType());
}
}
/// DeclareGlobalAllocationFunction - Declares a single implicit global
/// allocation function if it doesn't already exist.
void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
QualType Return,
QualType Param1, QualType Param2) {
DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
unsigned NumParams = Param2.isNull() ? 1 : 2;
// Check if this function is already declared.
DeclContext::lookup_result R = GlobalCtx->lookup(Name);
for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end();
Alloc != AllocEnd; ++Alloc) {
// Only look at non-template functions, as it is the predefined,
// non-templated allocation function we are trying to declare here.
if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
if (Func->getNumParams() == NumParams) {
QualType InitialParam1Type =
Context.getCanonicalType(Func->getParamDecl(0)
->getType().getUnqualifiedType());
QualType InitialParam2Type =
NumParams == 2
? Context.getCanonicalType(Func->getParamDecl(1)
->getType().getUnqualifiedType())
: QualType();
// FIXME: Do we need to check for default arguments here?
if (InitialParam1Type == Param1 &&
(NumParams == 1 || InitialParam2Type == Param2)) {
// Make the function visible to name lookup, even if we found it in
// an unimported module. It either is an implicitly-declared global
// allocation function, or is suppressing that function.
Func->setHidden(false);
return;
}
}
}
}
FunctionProtoType::ExtProtoInfo EPI;
QualType BadAllocType;
bool HasBadAllocExceptionSpec
= (Name.getCXXOverloadedOperator() == OO_New ||
Name.getCXXOverloadedOperator() == OO_Array_New);
if (HasBadAllocExceptionSpec) {
if (!getLangOpts().CPlusPlus11) {
BadAllocType = Context.getTypeDeclType(getStdBadAlloc());
assert(StdBadAlloc && "Must have std::bad_alloc declared");
EPI.ExceptionSpec.Type = EST_Dynamic;
EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType);
}
} else {
EPI.ExceptionSpec =
getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone;
}
QualType Params[] = { Param1, Param2 };
QualType FnType = Context.getFunctionType(
Return, llvm::makeArrayRef(Params, NumParams), EPI);
FunctionDecl *Alloc =
FunctionDecl::Create(Context, GlobalCtx, SourceLocation(),
SourceLocation(), Name,
FnType, /*TInfo=*/nullptr, SC_None, false, true);
Alloc->setImplicit();
// Implicit sized deallocation functions always have default visibility.
Alloc->addAttr(VisibilityAttr::CreateImplicit(Context,
VisibilityAttr::Default));
ParmVarDecl *ParamDecls[2];
for (unsigned I = 0; I != NumParams; ++I) {
ParamDecls[I] = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
SourceLocation(), nullptr,
Params[I], /*TInfo=*/nullptr,
SC_None, nullptr);
ParamDecls[I]->setImplicit();
}
Alloc->setParams(llvm::makeArrayRef(ParamDecls, NumParams));
Context.getTranslationUnitDecl()->addDecl(Alloc);
IdResolver.tryAddTopLevelDecl(Alloc, Name);
}
FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc,
bool CanProvideSize,
DeclarationName Name) {
DeclareGlobalNewDelete();
LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName);
LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl());
// C++ [expr.new]p20:
// [...] Any non-placement deallocation function matches a
// non-placement allocation function. [...]
llvm::SmallVector<FunctionDecl*, 2> Matches;
for (LookupResult::iterator D = FoundDelete.begin(),
DEnd = FoundDelete.end();
D != DEnd; ++D) {
if (FunctionDecl *Fn = dyn_cast<FunctionDecl>(*D))
if (isNonPlacementDeallocationFunction(*this, Fn))
Matches.push_back(Fn);
}
// C++1y [expr.delete]p?:
// If the type is complete and deallocation function lookup finds both a
// usual deallocation function with only a pointer parameter and a usual
// deallocation function with both a pointer parameter and a size
// parameter, then the selected deallocation function shall be the one
// with two parameters. Otherwise, the selected deallocation function
// shall be the function with one parameter.
if (getLangOpts().SizedDeallocation && Matches.size() == 2) {
unsigned NumArgs = CanProvideSize ? 2 : 1;
if (Matches[0]->getNumParams() != NumArgs)
Matches.erase(Matches.begin());
else
Matches.erase(Matches.begin() + 1);
assert(Matches[0]->getNumParams() == NumArgs &&
"found an unexpected usual deallocation function");
}
if (getLangOpts().CUDA)
EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);
assert(Matches.size() == 1 &&
"unexpectedly have multiple usual deallocation functions");
return Matches.front();
}
bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
DeclarationName Name,
FunctionDecl* &Operator, bool Diagnose) {
LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
// Try to find operator delete/operator delete[] in class scope.
LookupQualifiedName(Found, RD);
if (Found.isAmbiguous())
return true;
Found.suppressDiagnostics();
SmallVector<DeclAccessPair,4> Matches;
for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
F != FEnd; ++F) {
NamedDecl *ND = (*F)->getUnderlyingDecl();
// Ignore template operator delete members from the check for a usual
// deallocation function.
if (isa<FunctionTemplateDecl>(ND))
continue;
if (cast<CXXMethodDecl>(ND)->isUsualDeallocationFunction())
Matches.push_back(F.getPair());
}
if (getLangOpts().CUDA)
EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches);
// There's exactly one suitable operator; pick it.
if (Matches.size() == 1) {
Operator = cast<CXXMethodDecl>(Matches[0]->getUnderlyingDecl());
if (Operator->isDeleted()) {
if (Diagnose) {
Diag(StartLoc, diag::err_deleted_function_use);
NoteDeletedFunction(Operator);
}
return true;
}
if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(),
Matches[0], Diagnose) == AR_inaccessible)
return true;
return false;
// We found multiple suitable operators; complain about the ambiguity.
} else if (!Matches.empty()) {
if (Diagnose) {
Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found)
<< Name << RD;
for (SmallVectorImpl<DeclAccessPair>::iterator
F = Matches.begin(), FEnd = Matches.end(); F != FEnd; ++F)
Diag((*F)->getUnderlyingDecl()->getLocation(),
diag::note_member_declared_here) << Name;
}
return true;
}
// We did find operator delete/operator delete[] declarations, but
// none of them were suitable.
if (!Found.empty()) {
if (Diagnose) {
Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
<< Name << RD;
for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
F != FEnd; ++F)
Diag((*F)->getUnderlyingDecl()->getLocation(),
diag::note_member_declared_here) << Name;
}
return true;
}
Operator = nullptr;
return false;
}
namespace {
/// \brief Checks whether delete-expression, and new-expression used for
/// initializing deletee have the same array form.
class MismatchingNewDeleteDetector {
public:
enum MismatchResult {
/// Indicates that there is no mismatch or a mismatch cannot be proven.
NoMismatch,
/// Indicates that variable is initialized with mismatching form of \a new.
VarInitMismatches,
/// Indicates that member is initialized with mismatching form of \a new.
MemberInitMismatches,
/// Indicates that 1 or more constructors' definitions could not been
/// analyzed, and they will be checked again at the end of translation unit.
AnalyzeLater
};
/// \param EndOfTU True, if this is the final analysis at the end of
/// translation unit. False, if this is the initial analysis at the point
/// delete-expression was encountered.
explicit MismatchingNewDeleteDetector(bool EndOfTU)
: IsArrayForm(false), Field(nullptr), EndOfTU(EndOfTU),
HasUndefinedConstructors(false) {}
/// \brief Checks whether pointee of a delete-expression is initialized with
/// matching form of new-expression.
///
/// If return value is \c VarInitMismatches or \c MemberInitMismatches at the
/// point where delete-expression is encountered, then a warning will be
/// issued immediately. If return value is \c AnalyzeLater at the point where
/// delete-expression is seen, then member will be analyzed at the end of
/// translation unit. \c AnalyzeLater is returned iff at least one constructor
/// couldn't be analyzed. If at least one constructor initializes the member
/// with matching type of new, the return value is \c NoMismatch.
MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE);
/// \brief Analyzes a class member.
/// \param Field Class member to analyze.
/// \param DeleteWasArrayForm Array form-ness of the delete-expression used
/// for deleting the \p Field.
MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm);
/// List of mismatching new-expressions used for initialization of the pointee
llvm::SmallVector<const CXXNewExpr *, 4> NewExprs;
/// Indicates whether delete-expression was in array form.
bool IsArrayForm;
FieldDecl *Field;
private:
const bool EndOfTU;
/// \brief Indicates that there is at least one constructor without body.
bool HasUndefinedConstructors;
/// \brief Returns \c CXXNewExpr from given initialization expression.
/// \param E Expression used for initializing pointee in delete-expression.
/// E can be a single-element \c InitListExpr consisting of new-expression.
const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E);
/// \brief Returns whether member is initialized with mismatching form of
/// \c new either by the member initializer or in-class initialization.
///
/// If bodies of all constructors are not visible at the end of translation
/// unit or at least one constructor initializes member with the matching
/// form of \c new, mismatch cannot be proven, and this function will return
/// \c NoMismatch.
MismatchResult analyzeMemberExpr(const MemberExpr *ME);
/// \brief Returns whether variable is initialized with mismatching form of
/// \c new.
///
/// If variable is initialized with matching form of \c new or variable is not
/// initialized with a \c new expression, this function will return true.
/// If variable is initialized with mismatching form of \c new, returns false.
/// \param D Variable to analyze.
bool hasMatchingVarInit(const DeclRefExpr *D);
/// \brief Checks whether the constructor initializes pointee with mismatching
/// form of \c new.
///
/// Returns true, if member is initialized with matching form of \c new in
/// member initializer list. Returns false, if member is initialized with the
/// matching form of \c new in this constructor's initializer or given
/// constructor isn't defined at the point where delete-expression is seen, or
/// member isn't initialized by the constructor.
bool hasMatchingNewInCtor(const CXXConstructorDecl *CD);
/// \brief Checks whether member is initialized with matching form of
/// \c new in member initializer list.
bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI);
/// Checks whether member is initialized with mismatching form of \c new by
/// in-class initializer.
MismatchResult analyzeInClassInitializer();
};
}
MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) {
NewExprs.clear();
assert(DE && "Expected delete-expression");
IsArrayForm = DE->isArrayForm();
const Expr *E = DE->getArgument()->IgnoreParenImpCasts();
if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) {
return analyzeMemberExpr(ME);
} else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) {
if (!hasMatchingVarInit(D))
return VarInitMismatches;
}
return NoMismatch;
}
const CXXNewExpr *
MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) {
assert(E != nullptr && "Expected a valid initializer expression");
E = E->IgnoreParenImpCasts();
if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) {
if (ILE->getNumInits() == 1)
E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts());
}
return dyn_cast_or_null<const CXXNewExpr>(E);
}
bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit(
const CXXCtorInitializer *CI) {
const CXXNewExpr *NE = nullptr;
if (Field == CI->getMember() &&
(NE = getNewExprFromInitListOrExpr(CI->getInit()))) {
if (NE->isArray() == IsArrayForm)
return true;
else
NewExprs.push_back(NE);
}
return false;
}
bool MismatchingNewDeleteDetector::hasMatchingNewInCtor(
const CXXConstructorDecl *CD) {
if (CD->isImplicit())
return false;
const FunctionDecl *Definition = CD;
if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) {
HasUndefinedConstructors = true;
return EndOfTU;
}
for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) {
if (hasMatchingNewInCtorInit(CI))
return true;
}
return false;
}
MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeInClassInitializer() {
assert(Field != nullptr && "This should be called only for members");
const Expr *InitExpr = Field->getInClassInitializer();
if (!InitExpr)
return EndOfTU ? NoMismatch : AnalyzeLater;
if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) {
if (NE->isArray() != IsArrayForm) {
NewExprs.push_back(NE);
return MemberInitMismatches;
}
}
return NoMismatch;
}
MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field,
bool DeleteWasArrayForm) {
assert(Field != nullptr && "Analysis requires a valid class member.");
this->Field = Field;
IsArrayForm = DeleteWasArrayForm;
const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent());
for (const auto *CD : RD->ctors()) {
if (hasMatchingNewInCtor(CD))
return NoMismatch;
}
if (HasUndefinedConstructors)
return EndOfTU ? NoMismatch : AnalyzeLater;
if (!NewExprs.empty())
return MemberInitMismatches;
return Field->hasInClassInitializer() ? analyzeInClassInitializer()
: NoMismatch;
}
MismatchingNewDeleteDetector::MismatchResult
MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) {
assert(ME != nullptr && "Expected a member expression");
if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl()))
return analyzeField(F, IsArrayForm);
return NoMismatch;
}
bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) {
const CXXNewExpr *NE = nullptr;
if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) {
if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) &&
NE->isArray() != IsArrayForm) {
NewExprs.push_back(NE);
}
}
return NewExprs.empty();
}
static void
DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc,
const MismatchingNewDeleteDetector &Detector) {
SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc);
FixItHint H;
if (!Detector.IsArrayForm)
H = FixItHint::CreateInsertion(EndOfDelete, "[]");
else {
SourceLocation RSquare = Lexer::findLocationAfterToken(
DeleteLoc, tok::l_square, SemaRef.getSourceManager(),
SemaRef.getLangOpts(), true);
if (RSquare.isValid())
H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare));
}
SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new)
<< Detector.IsArrayForm << H;
for (const auto *NE : Detector.NewExprs)
SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here)
<< Detector.IsArrayForm;
}
void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) {
if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation()))
return;
MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false);
switch (Detector.analyzeDeleteExpr(DE)) {
case MismatchingNewDeleteDetector::VarInitMismatches:
case MismatchingNewDeleteDetector::MemberInitMismatches: {
DiagnoseMismatchedNewDelete(*this, DE->getLocStart(), Detector);
break;
}
case MismatchingNewDeleteDetector::AnalyzeLater: {
DeleteExprs[Detector.Field].push_back(
std::make_pair(DE->getLocStart(), DE->isArrayForm()));
break;
}
case MismatchingNewDeleteDetector::NoMismatch:
break;
}
}
void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
bool DeleteWasArrayForm) {
MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true);
switch (Detector.analyzeField(Field, DeleteWasArrayForm)) {
case MismatchingNewDeleteDetector::VarInitMismatches:
llvm_unreachable("This analysis should have been done for class members.");
case MismatchingNewDeleteDetector::AnalyzeLater:
llvm_unreachable("Analysis cannot be postponed any point beyond end of "
"translation unit.");
case MismatchingNewDeleteDetector::MemberInitMismatches:
DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector);
break;
case MismatchingNewDeleteDetector::NoMismatch:
break;
}
}
/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
/// @code ::delete ptr; @endcode
/// or
/// @code delete [] ptr; @endcode
ExprResult
Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
bool ArrayForm, Expr *ExE) {
// C++ [expr.delete]p1:
// The operand shall have a pointer type, or a class type having a single
// non-explicit conversion function to a pointer type. The result has type
// void.
//
// DR599 amends "pointer type" to "pointer to object type" in both cases.
ExprResult Ex = ExE;
FunctionDecl *OperatorDelete = nullptr;
bool ArrayFormAsWritten = ArrayForm;
bool UsualArrayDeleteWantsSize = false;
if (!Ex.get()->isTypeDependent()) {
// Perform lvalue-to-rvalue cast, if needed.
Ex = DefaultLvalueConversion(Ex.get());
if (Ex.isInvalid())
return ExprError();
QualType Type = Ex.get()->getType();
class DeleteConverter : public ContextualImplicitConverter {
public:
DeleteConverter() : ContextualImplicitConverter(false, true) {}
bool match(QualType ConvType) override {
// FIXME: If we have an operator T* and an operator void*, we must pick
// the operator T*.
if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType())
return true;
return false;
}
SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc,
QualType T) override {
return S.Diag(Loc, diag::err_delete_operand) << T;
}
SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
QualType T) override {
return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T;
}
SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
QualType T,
QualType ConvTy) override {
return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy;
}
SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
QualType ConvTy) override {
return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
<< ConvTy;
}
SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
QualType T) override {
return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T;
}
SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
QualType ConvTy) override {
return S.Diag(Conv->getLocation(), diag::note_delete_conversion)
<< ConvTy;
}
SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc,
QualType T,
QualType ConvTy) override {
llvm_unreachable("conversion functions are permitted");
}
} Converter;
Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter);
if (Ex.isInvalid())
return ExprError();
Type = Ex.get()->getType();
if (!Converter.match(Type))
// FIXME: PerformContextualImplicitConversion should return ExprError
// itself in this case.
return ExprError();
QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
QualType PointeeElem = Context.getBaseElementType(Pointee);
if (unsigned AddressSpace = Pointee.getAddressSpace())
return Diag(Ex.get()->getLocStart(),
diag::err_address_space_qualified_delete)
<< Pointee.getUnqualifiedType() << AddressSpace;
CXXRecordDecl *PointeeRD = nullptr;
if (Pointee->isVoidType() && !isSFINAEContext()) {
// The C++ standard bans deleting a pointer to a non-object type, which
// effectively bans deletion of "void*". However, most compilers support
// this, so we treat it as a warning unless we're in a SFINAE context.
Diag(StartLoc, diag::ext_delete_void_ptr_operand)
<< Type << Ex.get()->getSourceRange();
} else if (Pointee->isFunctionType() || Pointee->isVoidType()) {
return ExprError(Diag(StartLoc, diag::err_delete_operand)
<< Type << Ex.get()->getSourceRange());
} else if (!Pointee->isDependentType()) {
// FIXME: This can result in errors if the definition was imported from a
// module but is hidden.
if (!RequireCompleteType(StartLoc, Pointee,
diag::warn_delete_incomplete, Ex.get())) {
if (const RecordType *RT = PointeeElem->getAs<RecordType>())
PointeeRD = cast<CXXRecordDecl>(RT->getDecl());
}
}
if (Pointee->isArrayType() && !ArrayForm) {
Diag(StartLoc, diag::warn_delete_array_type)
<< Type << Ex.get()->getSourceRange()
<< FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]");
ArrayForm = true;
}
DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
ArrayForm ? OO_Array_Delete : OO_Delete);
if (PointeeRD) {
if (!UseGlobal &&
FindDeallocationFunction(StartLoc, PointeeRD, DeleteName,
OperatorDelete))
return ExprError();
// If we're allocating an array of records, check whether the
// usual operator delete[] has a size_t parameter.
if (ArrayForm) {
// If the user specifically asked to use the global allocator,
// we'll need to do the lookup into the class.
if (UseGlobal)
UsualArrayDeleteWantsSize =
doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem);
// Otherwise, the usual operator delete[] should be the
// function we just found.
else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete))
UsualArrayDeleteWantsSize = (OperatorDelete->getNumParams() == 2);
}
if (!PointeeRD->hasIrrelevantDestructor())
if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
MarkFunctionReferenced(StartLoc,
const_cast<CXXDestructorDecl*>(Dtor));
if (DiagnoseUseOfDecl(Dtor, StartLoc))
return ExprError();
}
CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc,
/*IsDelete=*/true, /*CallCanBeVirtual=*/true,
/*WarnOnNonAbstractTypes=*/!ArrayForm,
SourceLocation());
}
if (!OperatorDelete)
// Look for a global declaration.
OperatorDelete = FindUsualDeallocationFunction(
StartLoc, isCompleteType(StartLoc, Pointee) &&
(!ArrayForm || UsualArrayDeleteWantsSize ||
Pointee.isDestructedType()),
DeleteName);
MarkFunctionReferenced(StartLoc, OperatorDelete);
// Check access and ambiguity of operator delete and destructor.
if (PointeeRD) {
if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) {
CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor,
PDiag(diag::err_access_dtor) << PointeeElem);
}
}
}
CXXDeleteExpr *Result = new (Context) CXXDeleteExpr(
Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten,
UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc);
AnalyzeDeleteExprMismatch(Result);
return Result;
}
void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
bool IsDelete, bool CallCanBeVirtual,
bool WarnOnNonAbstractTypes,
SourceLocation DtorLoc) {
if (!dtor || dtor->isVirtual() || !CallCanBeVirtual)
return;
// C++ [expr.delete]p3:
// In the first alternative (delete object), if the static type of the
// object to be deleted is different from its dynamic type, the static
// type shall be a base class of the dynamic type of the object to be
// deleted and the static type shall have a virtual destructor or the
// behavior is undefined.
//
const CXXRecordDecl *PointeeRD = dtor->getParent();
// Note: a final class cannot be derived from, no issue there
if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>())
return;
QualType ClassType = dtor->getThisType(Context)->getPointeeType();
if (PointeeRD->isAbstract()) {
// If the class is abstract, we warn by default, because we're
// sure the code has undefined behavior.
Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1)
<< ClassType;
} else if (WarnOnNonAbstractTypes) {
// Otherwise, if this is not an array delete, it's a bit suspect,
// but not necessarily wrong.
Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1)
<< ClassType;
}
if (!IsDelete) {
std::string TypeStr;
ClassType.getAsStringInternal(TypeStr, getPrintingPolicy());
Diag(DtorLoc, diag::note_delete_non_virtual)
<< FixItHint::CreateInsertion(DtorLoc, TypeStr + "::");
}
}
/// \brief Check the use of the given variable as a C++ condition in an if,
/// while, do-while, or switch statement.
ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar,
SourceLocation StmtLoc,
bool ConvertToBoolean) {
if (ConditionVar->isInvalidDecl())
return ExprError();
QualType T = ConditionVar->getType();
// C++ [stmt.select]p2:
// The declarator shall not specify a function or an array.
if (T->isFunctionType())
return ExprError(Diag(ConditionVar->getLocation(),
diag::err_invalid_use_of_function_type)
<< ConditionVar->getSourceRange());
else if (T->isArrayType())
return ExprError(Diag(ConditionVar->getLocation(),
diag::err_invalid_use_of_array_type)
<< ConditionVar->getSourceRange());
ExprResult Condition = DeclRefExpr::Create(
Context, NestedNameSpecifierLoc(), SourceLocation(), ConditionVar,
/*enclosing*/ false, ConditionVar->getLocation(),
ConditionVar->getType().getNonReferenceType(), VK_LValue);
MarkDeclRefReferenced(cast<DeclRefExpr>(Condition.get()));
if (ConvertToBoolean) {
Condition = CheckBooleanCondition(Condition.get(), StmtLoc);
if (Condition.isInvalid())
return ExprError();
}
return Condition;
}
/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr) {
// C++ 6.4p4:
// The value of a condition that is an initialized declaration in a statement
// other than a switch statement is the value of the declared variable
// implicitly converted to type bool. If that conversion is ill-formed, the
// program is ill-formed.
// The value of a condition that is an expression is the value of the
// expression, implicitly converted to bool.
//
return PerformContextuallyConvertToBool(CondExpr);
}
/// Helper function to determine whether this is the (deprecated) C++
/// conversion from a string literal to a pointer to non-const char or
/// non-const wchar_t (for narrow and wide string literals,
/// respectively).
bool
Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
// Look inside the implicit cast, if it exists.
if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
From = Cast->getSubExpr();
// A string literal (2.13.4) that is not a wide string literal can
// be converted to an rvalue of type "pointer to char"; a wide
// string literal can be converted to an rvalue of type "pointer
// to wchar_t" (C++ 4.2p2).
if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens()))
if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
if (const BuiltinType *ToPointeeType
= ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
// This conversion is considered only when there is an
// explicit appropriate pointer target type (C++ 4.2p2).
if (!ToPtrType->getPointeeType().hasQualifiers()) {
switch (StrLit->getKind()) {
case StringLiteral::UTF8:
case StringLiteral::UTF16:
case StringLiteral::UTF32:
// We don't allow UTF literals to be implicitly converted
break;
case StringLiteral::Ascii:
return (ToPointeeType->getKind() == BuiltinType::Char_U ||
ToPointeeType->getKind() == BuiltinType::Char_S);
case StringLiteral::Wide:
return Context.typesAreCompatible(Context.getWideCharType(),
QualType(ToPointeeType, 0));
}
}
}
return false;
}
static ExprResult BuildCXXCastArgument(Sema &S,
SourceLocation CastLoc,
QualType Ty,
CastKind Kind,
CXXMethodDecl *Method,
DeclAccessPair FoundDecl,
bool HadMultipleCandidates,
Expr *From) {
switch (Kind) {
default: llvm_unreachable("Unhandled cast kind!");
case CK_ConstructorConversion: {
CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method);
SmallVector<Expr*, 8> ConstructorArgs;
if (S.RequireNonAbstractType(CastLoc, Ty,
diag::err_allocation_of_abstract_type))
return ExprError();
if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs))
return ExprError();
S.CheckConstructorAccess(CastLoc, Constructor,
InitializedEntity::InitializeTemporary(Ty),
Constructor->getAccess());
if (S.DiagnoseUseOfDecl(Method, CastLoc))
return ExprError();
ExprResult Result = S.BuildCXXConstructExpr(
CastLoc, Ty, cast<CXXConstructorDecl>(Method),
ConstructorArgs, HadMultipleCandidates,
/*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
CXXConstructExpr::CK_Complete, SourceRange());
if (Result.isInvalid())
return ExprError();
return S.MaybeBindToTemporary(Result.getAs<Expr>());
}
case CK_UserDefinedConversion: {
assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl);
if (S.DiagnoseUseOfDecl(Method, CastLoc))
return ExprError();
// Create an implicit call expr that calls it.
CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method);
ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv,
HadMultipleCandidates);
if (Result.isInvalid())
return ExprError();
// Record usage of conversion in an implicit cast.
Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(),
CK_UserDefinedConversion, Result.get(),
nullptr, Result.get()->getValueKind());
return S.MaybeBindToTemporary(Result.get());
}
}
}
/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType using the pre-computed implicit
/// conversion sequence ICS. Returns the converted
/// expression. Action is the kind of conversion we're performing,
/// used in the error message.
ExprResult
Sema::PerformImplicitConversion(Expr *From, QualType ToType,
const ImplicitConversionSequence &ICS,
AssignmentAction Action,
CheckedConversionKind CCK) {
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion: {
ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard,
Action, CCK);
if (Res.isInvalid())
return ExprError();
From = Res.get();
break;
}
case ImplicitConversionSequence::UserDefinedConversion: {
FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
CastKind CastKind;
QualType BeforeToType;
assert(FD && "no conversion function for user-defined conversion seq");
if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
CastKind = CK_UserDefinedConversion;
// If the user-defined conversion is specified by a conversion function,
// the initial standard conversion sequence converts the source type to
// the implicit object parameter of the conversion function.
BeforeToType = Context.getTagDeclType(Conv->getParent());
} else {
const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD);
CastKind = CK_ConstructorConversion;
// Do no conversion if dealing with ... for the first conversion.
if (!ICS.UserDefined.EllipsisConversion) {
// If the user-defined conversion is specified by a constructor, the
// initial standard conversion sequence converts the source type to
// the type required by the argument of the constructor
BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
}
}
// Watch out for ellipsis conversion.
if (!ICS.UserDefined.EllipsisConversion) {
ExprResult Res =
PerformImplicitConversion(From, BeforeToType,
ICS.UserDefined.Before, AA_Converting,
CCK);
if (Res.isInvalid())
return ExprError();
From = Res.get();
}
ExprResult CastArg
= BuildCXXCastArgument(*this,
From->getLocStart(),
ToType.getNonReferenceType(),
CastKind, cast<CXXMethodDecl>(FD),
ICS.UserDefined.FoundConversionFunction,
ICS.UserDefined.HadMultipleCandidates,
From);
if (CastArg.isInvalid())
return ExprError();
From = CastArg.get();
return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
AA_Converting, CCK);
}
case ImplicitConversionSequence::AmbiguousConversion:
ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(),
PDiag(diag::err_typecheck_ambiguous_condition)
<< From->getSourceRange());
return ExprError();
case ImplicitConversionSequence::EllipsisConversion:
llvm_unreachable("Cannot perform an ellipsis conversion");
case ImplicitConversionSequence::BadConversion:
return ExprError();
}
// Everything went well.
return From;
}
/// PerformImplicitConversion - Perform an implicit conversion of the
/// expression From to the type ToType by following the standard
/// conversion sequence SCS. Returns the converted
/// expression. Flavor is the context in which we're performing this
/// conversion, for use in error messages.
ExprResult
Sema::PerformImplicitConversion(Expr *From, QualType ToType,
const StandardConversionSequence& SCS,
AssignmentAction Action,
CheckedConversionKind CCK) {
bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast);
// Overall FIXME: we are recomputing too many types here and doing far too
// much extra work. What this means is that we need to keep track of more
// information that is computed when we try the implicit conversion initially,
// so that we don't need to recompute anything here.
QualType FromType = From->getType();
if (SCS.CopyConstructor) {
// FIXME: When can ToType be a reference type?
assert(!ToType->isReferenceType());
if (SCS.Second == ICK_Derived_To_Base) {
SmallVector<Expr*, 8> ConstructorArgs;
if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor),
From, /*FIXME:ConstructLoc*/SourceLocation(),
ConstructorArgs))
return ExprError();
return BuildCXXConstructExpr(
/*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor,
ConstructorArgs, /*HadMultipleCandidates*/ false,
/*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
CXXConstructExpr::CK_Complete, SourceRange());
}
return BuildCXXConstructExpr(
/*FIXME:ConstructLoc*/ SourceLocation(), ToType, SCS.CopyConstructor,
From, /*HadMultipleCandidates*/ false,
/*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false,
CXXConstructExpr::CK_Complete, SourceRange());
}
// Resolve overloaded function references.
if (Context.hasSameType(FromType, Context.OverloadTy)) {
DeclAccessPair Found;
FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType,
true, Found);
if (!Fn)
return ExprError();
if (DiagnoseUseOfDecl(Fn, From->getLocStart()))
return ExprError();
From = FixOverloadedFunctionReference(From, Found, Fn);
FromType = From->getType();
}
// If we're converting to an atomic type, first convert to the corresponding
// non-atomic type.
QualType ToAtomicType;
if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) {
ToAtomicType = ToType;
ToType = ToAtomic->getValueType();
}
QualType InitialFromType = FromType;
// Perform the first implicit conversion.
switch (SCS.First) {
case ICK_Identity:
if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) {
FromType = FromAtomic->getValueType().getUnqualifiedType();
From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic,
From, /*BasePath=*/nullptr, VK_RValue);
}
break;
case ICK_Lvalue_To_Rvalue: {
assert(From->getObjectKind() != OK_ObjCProperty);
ExprResult FromRes = DefaultLvalueConversion(From);
assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!");
From = FromRes.get();
FromType = From->getType();
break;
}
case ICK_Array_To_Pointer:
FromType = Context.getArrayDecayedType(FromType);
From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Function_To_Pointer:
FromType = Context.getPointerType(FromType);
From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
default:
llvm_unreachable("Improper first standard conversion");
}
// Perform the second implicit conversion
switch (SCS.Second) {
case ICK_Identity:
// C++ [except.spec]p5:
// [For] assignment to and initialization of pointers to functions,
// pointers to member functions, and references to functions: the
// target entity shall allow at least the exceptions allowed by the
// source value in the assignment or initialization.
switch (Action) {
case AA_Assigning:
case AA_Initializing:
// Note, function argument passing and returning are initialization.
case AA_Passing:
case AA_Returning:
case AA_Sending:
case AA_Passing_CFAudited:
if (CheckExceptionSpecCompatibility(From, ToType))
return ExprError();
break;
case AA_Casting:
case AA_Converting:
// Casts and implicit conversions are not initialization, so are not
// checked for exception specification mismatches.
break;
}
// Nothing else to do.
break;
case ICK_NoReturn_Adjustment:
// If both sides are functions (or pointers/references to them), there could
// be incompatible exception declarations.
if (CheckExceptionSpecCompatibility(From, ToType))
return ExprError();
From = ImpCastExprToType(From, ToType, CK_NoOp,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Integral_Promotion:
case ICK_Integral_Conversion:
if (ToType->isBooleanType()) {
assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&
SCS.Second == ICK_Integral_Promotion &&
"only enums with fixed underlying type can promote to bool");
From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
} else {
From = ImpCastExprToType(From, ToType, CK_IntegralCast,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
}
break;
case ICK_Floating_Promotion:
case ICK_Floating_Conversion:
From = ImpCastExprToType(From, ToType, CK_FloatingCast,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Complex_Promotion:
case ICK_Complex_Conversion: {
QualType FromEl = From->getType()->getAs<ComplexType>()->getElementType();
QualType ToEl = ToType->getAs<ComplexType>()->getElementType();
CastKind CK;
if (FromEl->isRealFloatingType()) {
if (ToEl->isRealFloatingType())
CK = CK_FloatingComplexCast;
else
CK = CK_FloatingComplexToIntegralComplex;
} else if (ToEl->isRealFloatingType()) {
CK = CK_IntegralComplexToFloatingComplex;
} else {
CK = CK_IntegralComplexCast;
}
From = ImpCastExprToType(From, ToType, CK,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
}
case ICK_Floating_Integral:
if (ToType->isRealFloatingType())
From = ImpCastExprToType(From, ToType, CK_IntegralToFloating,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
else
From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Compatible_Conversion:
From = ImpCastExprToType(From, ToType, CK_NoOp,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Writeback_Conversion:
case ICK_Pointer_Conversion: {
if (SCS.IncompatibleObjC && Action != AA_Casting) {
// Diagnose incompatible Objective-C conversions
if (Action == AA_Initializing || Action == AA_Assigning)
Diag(From->getLocStart(),
diag::ext_typecheck_convert_incompatible_pointer)
<< ToType << From->getType() << Action
<< From->getSourceRange() << 0;
else
Diag(From->getLocStart(),
diag::ext_typecheck_convert_incompatible_pointer)
<< From->getType() << ToType << Action
<< From->getSourceRange() << 0;
if (From->getType()->isObjCObjectPointerType() &&
ToType->isObjCObjectPointerType())
EmitRelatedResultTypeNote(From);
}
else if (getLangOpts().ObjCAutoRefCount &&
!CheckObjCARCUnavailableWeakConversion(ToType,
From->getType())) {
if (Action == AA_Initializing)
Diag(From->getLocStart(),
diag::err_arc_weak_unavailable_assign);
else
Diag(From->getLocStart(),
diag::err_arc_convesion_of_weak_unavailable)
<< (Action == AA_Casting) << From->getType() << ToType
<< From->getSourceRange();
}
CastKind Kind = CK_Invalid;
CXXCastPath BasePath;
if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
return ExprError();
// Make sure we extend blocks if necessary.
// FIXME: doing this here is really ugly.
if (Kind == CK_BlockPointerToObjCPointerCast) {
ExprResult E = From;
(void) PrepareCastToObjCObjectPointer(E);
From = E.get();
}
if (getLangOpts().ObjCAutoRefCount)
CheckObjCARCConversion(SourceRange(), ToType, From, CCK);
From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
.get();
break;
}
case ICK_Pointer_Member: {
CastKind Kind = CK_Invalid;
CXXCastPath BasePath;
if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
return ExprError();
if (CheckExceptionSpecCompatibility(From, ToType))
return ExprError();
// We may not have been able to figure out what this member pointer resolved
// to up until this exact point. Attempt to lock-in it's inheritance model.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
(void)isCompleteType(From->getExprLoc(), From->getType());
(void)isCompleteType(From->getExprLoc(), ToType);
}
From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK)
.get();
break;
}
case ICK_Boolean_Conversion:
// Perform half-to-boolean conversion via float.
if (From->getType()->isHalfType()) {
From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get();
FromType = Context.FloatTy;
}
From = ImpCastExprToType(From, Context.BoolTy,
ScalarTypeToBooleanCastKind(FromType),
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Derived_To_Base: {
CXXCastPath BasePath;
if (CheckDerivedToBaseConversion(From->getType(),
ToType.getNonReferenceType(),
From->getLocStart(),
From->getSourceRange(),
&BasePath,
CStyle))
return ExprError();
From = ImpCastExprToType(From, ToType.getNonReferenceType(),
CK_DerivedToBase, From->getValueKind(),
&BasePath, CCK).get();
break;
}
case ICK_Vector_Conversion:
From = ImpCastExprToType(From, ToType, CK_BitCast,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
case ICK_Vector_Splat: {
// Vector splat from any arithmetic type to a vector.
Expr *Elem = prepareVectorSplat(ToType, From).get();
From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_RValue,
/*BasePath=*/nullptr, CCK).get();
break;
}
case ICK_Complex_Real:
// Case 1. x -> _Complex y
if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) {
QualType ElType = ToComplex->getElementType();
bool isFloatingComplex = ElType->isRealFloatingType();
// x -> y
if (Context.hasSameUnqualifiedType(ElType, From->getType())) {
// do nothing
} else if (From->getType()->isRealFloatingType()) {
From = ImpCastExprToType(From, ElType,
isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get();
} else {
assert(From->getType()->isIntegerType());
From = ImpCastExprToType(From, ElType,
isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get();
}
// y -> _Complex y
From = ImpCastExprToType(From, ToType,
isFloatingComplex ? CK_FloatingRealToComplex
: CK_IntegralRealToComplex).get();
// Case 2. _Complex x -> y
} else {
const ComplexType *FromComplex = From->getType()->getAs<ComplexType>();
assert(FromComplex);
QualType ElType = FromComplex->getElementType();
bool isFloatingComplex = ElType->isRealFloatingType();
// _Complex x -> x
From = ImpCastExprToType(From, ElType,
isFloatingComplex ? CK_FloatingComplexToReal
: CK_IntegralComplexToReal,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
// x -> y
if (Context.hasSameUnqualifiedType(ElType, ToType)) {
// do nothing
} else if (ToType->isRealFloatingType()) {
From = ImpCastExprToType(From, ToType,
isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
} else {
assert(ToType->isIntegerType());
From = ImpCastExprToType(From, ToType,
isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
}
}
break;
case ICK_Block_Pointer_Conversion: {
From = ImpCastExprToType(From, ToType.getUnqualifiedType(), CK_BitCast,
VK_RValue, /*BasePath=*/nullptr, CCK).get();
break;
}
case ICK_TransparentUnionConversion: {
ExprResult FromRes = From;
Sema::AssignConvertType ConvTy =
CheckTransparentUnionArgumentConstraints(ToType, FromRes);
if (FromRes.isInvalid())
return ExprError();
From = FromRes.get();
assert ((ConvTy == Sema::Compatible) &&
"Improper transparent union conversion");
(void)ConvTy;
break;
}
case ICK_Zero_Event_Conversion:
From = ImpCastExprToType(From, ToType,
CK_ZeroToOCLEvent,
From->getValueKind()).get();
break;
case ICK_Lvalue_To_Rvalue:
case ICK_Array_To_Pointer:
case ICK_Function_To_Pointer:
case ICK_Qualification:
case ICK_Num_Conversion_Kinds:
case ICK_C_Only_Conversion:
llvm_unreachable("Improper second standard conversion");
}
switch (SCS.Third) {
case ICK_Identity:
// Nothing to do.
break;
case ICK_Qualification: {
// The qualification keeps the category of the inner expression, unless the
// target type isn't a reference.
ExprValueKind VK = ToType->isReferenceType() ?
From->getValueKind() : VK_RValue;
From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context),
CK_NoOp, VK, /*BasePath=*/nullptr, CCK).get();
if (SCS.DeprecatedStringLiteralToCharPtr &&
!getLangOpts().WritableStrings) {
Diag(From->getLocStart(), getLangOpts().CPlusPlus11
? diag::ext_deprecated_string_literal_conversion
: diag::warn_deprecated_string_literal_conversion)
<< ToType.getNonReferenceType();
}
break;
}
default:
llvm_unreachable("Improper third standard conversion");
}
// If this conversion sequence involved a scalar -> atomic conversion, perform
// that conversion now.
if (!ToAtomicType.isNull()) {
assert(Context.hasSameType(
ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()));
From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic,
VK_RValue, nullptr, CCK).get();
}
// If this conversion sequence succeeded and involved implicitly converting a
// _Nullable type to a _Nonnull one, complain.
if (CCK == CCK_ImplicitConversion)
diagnoseNullableToNonnullConversion(ToType, InitialFromType,
From->getLocStart());
return From;
}
/// \brief Check the completeness of a type in a unary type trait.
///
/// If the particular type trait requires a complete type, tries to complete
/// it. If completing the type fails, a diagnostic is emitted and false
/// returned. If completing the type succeeds or no completion was required,
/// returns true.
static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT,
SourceLocation Loc,
QualType ArgTy) {
// C++0x [meta.unary.prop]p3:
// For all of the class templates X declared in this Clause, instantiating
// that template with a template argument that is a class template
// specialization may result in the implicit instantiation of the template
// argument if and only if the semantics of X require that the argument
// must be a complete type.
// We apply this rule to all the type trait expressions used to implement
// these class templates. We also try to follow any GCC documented behavior
// in these expressions to ensure portability of standard libraries.
switch (UTT) {
default: llvm_unreachable("not a UTT");
// is_complete_type somewhat obviously cannot require a complete type.
case UTT_IsCompleteType:
// Fall-through
// These traits are modeled on the type predicates in C++0x
// [meta.unary.cat] and [meta.unary.comp]. They are not specified as
// requiring a complete type, as whether or not they return true cannot be
// impacted by the completeness of the type.
case UTT_IsVoid:
case UTT_IsIntegral:
case UTT_IsFloatingPoint:
case UTT_IsArray:
case UTT_IsPointer:
case UTT_IsLvalueReference:
case UTT_IsRvalueReference:
case UTT_IsMemberFunctionPointer:
case UTT_IsMemberObjectPointer:
case UTT_IsEnum:
case UTT_IsUnion:
case UTT_IsClass:
case UTT_IsFunction:
case UTT_IsReference:
case UTT_IsArithmetic:
case UTT_IsFundamental:
case UTT_IsObject:
case UTT_IsScalar:
case UTT_IsCompound:
case UTT_IsMemberPointer:
// Fall-through
// These traits are modeled on type predicates in C++0x [meta.unary.prop]
// which requires some of its traits to have the complete type. However,
// the completeness of the type cannot impact these traits' semantics, and
// so they don't require it. This matches the comments on these traits in
// Table 49.
case UTT_IsConst:
case UTT_IsVolatile:
case UTT_IsSigned:
case UTT_IsUnsigned:
// This type trait always returns false, checking the type is moot.
case UTT_IsInterfaceClass:
return true;
// C++14 [meta.unary.prop]:
// If T is a non-union class type, T shall be a complete type.
case UTT_IsEmpty:
case UTT_IsPolymorphic:
case UTT_IsAbstract:
if (const auto *RD = ArgTy->getAsCXXRecordDecl())
if (!RD->isUnion())
return !S.RequireCompleteType(
Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
return true;
// C++14 [meta.unary.prop]:
// If T is a class type, T shall be a complete type.
case UTT_IsFinal:
case UTT_IsSealed:
if (ArgTy->getAsCXXRecordDecl())
return !S.RequireCompleteType(
Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr);
return true;
// C++0x [meta.unary.prop] Table 49 requires the following traits to be
// applied to a complete type.
case UTT_IsTrivial:
case UTT_IsTriviallyCopyable:
case UTT_IsStandardLayout:
case UTT_IsPOD:
case UTT_IsLiteral:
case UTT_IsDestructible:
case UTT_IsNothrowDestructible:
// Fall-through
// These trait expressions are designed to help implement predicates in
// [meta.unary.prop] despite not being named the same. They are specified
// by both GCC and the Embarcadero C++ compiler, and require the complete
// type due to the overarching C++0x type predicates being implemented
// requiring the complete type.
case UTT_HasNothrowAssign:
case UTT_HasNothrowMoveAssign:
case UTT_HasNothrowConstructor:
case UTT_HasNothrowCopy:
case UTT_HasTrivialAssign:
case UTT_HasTrivialMoveAssign:
case UTT_HasTrivialDefaultConstructor:
case UTT_HasTrivialMoveConstructor:
case UTT_HasTrivialCopy:
case UTT_HasTrivialDestructor:
case UTT_HasVirtualDestructor:
// Arrays of unknown bound are expressly allowed.
QualType ElTy = ArgTy;
if (ArgTy->isIncompleteArrayType())
ElTy = S.Context.getAsArrayType(ArgTy)->getElementType();
// The void type is expressly allowed.
if (ElTy->isVoidType())
return true;
return !S.RequireCompleteType(
Loc, ElTy, diag::err_incomplete_type_used_in_type_trait_expr);
}
}
static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op,
Sema &Self, SourceLocation KeyLoc, ASTContext &C,
bool (CXXRecordDecl::*HasTrivial)() const,
bool (CXXRecordDecl::*HasNonTrivial)() const,
bool (CXXMethodDecl::*IsDesiredOp)() const)
{
CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)())
return true;
DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op);
DeclarationNameInfo NameInfo(Name, KeyLoc);
LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName);
if (Self.LookupQualifiedName(Res, RD)) {
bool FoundOperator = false;
Res.suppressDiagnostics();
for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end();
Op != OpEnd; ++Op) {
if (isa<FunctionTemplateDecl>(*Op))
continue;
CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op);
if((Operator->*IsDesiredOp)()) {
FoundOperator = true;
const FunctionProtoType *CPT =
Operator->getType()->getAs<FunctionProtoType>();
CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
if (!CPT || !CPT->isNothrow(C))
return false;
}
}
return FoundOperator;
}
return false;
}
static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT,
SourceLocation KeyLoc, QualType T) {
assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
ASTContext &C = Self.Context;
switch(UTT) {
default: llvm_unreachable("not a UTT");
// Type trait expressions corresponding to the primary type category
// predicates in C++0x [meta.unary.cat].
case UTT_IsVoid:
return T->isVoidType();
case UTT_IsIntegral:
return T->isIntegralType(C);
case UTT_IsFloatingPoint:
return T->isFloatingType();
case UTT_IsArray:
return T->isArrayType();
case UTT_IsPointer:
return T->isPointerType();
case UTT_IsLvalueReference:
return T->isLValueReferenceType();
case UTT_IsRvalueReference:
return T->isRValueReferenceType();
case UTT_IsMemberFunctionPointer:
return T->isMemberFunctionPointerType();
case UTT_IsMemberObjectPointer:
return T->isMemberDataPointerType();
case UTT_IsEnum:
return T->isEnumeralType();
case UTT_IsUnion:
return T->isUnionType();
case UTT_IsClass:
return T->isClassType() || T->isStructureType() || T->isInterfaceType();
case UTT_IsFunction:
return T->isFunctionType();
// Type trait expressions which correspond to the convenient composition
// predicates in C++0x [meta.unary.comp].
case UTT_IsReference:
return T->isReferenceType();
case UTT_IsArithmetic:
return T->isArithmeticType() && !T->isEnumeralType();
case UTT_IsFundamental:
return T->isFundamentalType();
case UTT_IsObject:
return T->isObjectType();
case UTT_IsScalar:
// Note: semantic analysis depends on Objective-C lifetime types to be
// considered scalar types. However, such types do not actually behave
// like scalar types at run time (since they may require retain/release
// operations), so we report them as non-scalar.
if (T->isObjCLifetimeType()) {
switch (T.getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
return true;
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Weak:
case Qualifiers::OCL_Autoreleasing:
return false;
}
}
return T->isScalarType();
case UTT_IsCompound:
return T->isCompoundType();
case UTT_IsMemberPointer:
return T->isMemberPointerType();
// Type trait expressions which correspond to the type property predicates
// in C++0x [meta.unary.prop].
case UTT_IsConst:
return T.isConstQualified();
case UTT_IsVolatile:
return T.isVolatileQualified();
case UTT_IsTrivial:
return T.isTrivialType(C);
case UTT_IsTriviallyCopyable:
return T.isTriviallyCopyableType(C);
case UTT_IsStandardLayout:
return T->isStandardLayoutType();
case UTT_IsPOD:
return T.isPODType(C);
case UTT_IsLiteral:
return T->isLiteralType(C);
case UTT_IsEmpty:
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return !RD->isUnion() && RD->isEmpty();
return false;
case UTT_IsPolymorphic:
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return !RD->isUnion() && RD->isPolymorphic();
return false;
case UTT_IsAbstract:
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return !RD->isUnion() && RD->isAbstract();
return false;
// __is_interface_class only returns true when CL is invoked in /CLR mode and
// even then only when it is used with the 'interface struct ...' syntax
// Clang doesn't support /CLR which makes this type trait moot.
case UTT_IsInterfaceClass:
return false;
case UTT_IsFinal:
case UTT_IsSealed:
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return RD->hasAttr<FinalAttr>();
return false;
case UTT_IsSigned:
return T->isSignedIntegerType();
case UTT_IsUnsigned:
return T->isUnsignedIntegerType();
// Type trait expressions which query classes regarding their construction,
// destruction, and copying. Rather than being based directly on the
// related type predicates in the standard, they are specified by both
// GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those
// specifications.
//
// 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html
// 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
//
// Note that these builtins do not behave as documented in g++: if a class
// has both a trivial and a non-trivial special member of a particular kind,
// they return false! For now, we emulate this behavior.
// FIXME: This appears to be a g++ bug: more complex cases reveal that it
// does not correctly compute triviality in the presence of multiple special
// members of the same kind. Revisit this once the g++ bug is fixed.
case UTT_HasTrivialDefaultConstructor:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If __is_pod (type) is true then the trait is true, else if type is
// a cv class or union type (or array thereof) with a trivial default
// constructor ([class.ctor]) then the trait is true, else it is false.
if (T.isPODType(C))
return true;
if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
return RD->hasTrivialDefaultConstructor() &&
!RD->hasNonTrivialDefaultConstructor();
return false;
case UTT_HasTrivialMoveConstructor:
// This trait is implemented by MSVC 2012 and needed to parse the
// standard library headers. Specifically this is used as the logic
// behind std::is_trivially_move_constructible (20.9.4.3).
if (T.isPODType(C))
return true;
if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor();
return false;
case UTT_HasTrivialCopy:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If __is_pod (type) is true or type is a reference type then
// the trait is true, else if type is a cv class or union type
// with a trivial copy constructor ([class.copy]) then the trait
// is true, else it is false.
if (T.isPODType(C) || T->isReferenceType())
return true;
if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return RD->hasTrivialCopyConstructor() &&
!RD->hasNonTrivialCopyConstructor();
return false;
case UTT_HasTrivialMoveAssign:
// This trait is implemented by MSVC 2012 and needed to parse the
// standard library headers. Specifically it is used as the logic
// behind std::is_trivially_move_assignable (20.9.4.3)
if (T.isPODType(C))
return true;
if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment();
return false;
case UTT_HasTrivialAssign:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If type is const qualified or is a reference type then the
// trait is false. Otherwise if __is_pod (type) is true then the
// trait is true, else if type is a cv class or union type with
// a trivial copy assignment ([class.copy]) then the trait is
// true, else it is false.
// Note: the const and reference restrictions are interesting,
// given that const and reference members don't prevent a class
// from having a trivial copy assignment operator (but do cause
// errors if the copy assignment operator is actually used, q.v.
// [class.copy]p12).
if (T.isConstQualified())
return false;
if (T.isPODType(C))
return true;
if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
return RD->hasTrivialCopyAssignment() &&
!RD->hasNonTrivialCopyAssignment();
return false;
case UTT_IsDestructible:
case UTT_IsNothrowDestructible:
// C++14 [meta.unary.prop]:
// For reference types, is_destructible<T>::value is true.
if (T->isReferenceType())
return true;
// Objective-C++ ARC: autorelease types don't require destruction.
if (T->isObjCLifetimeType() &&
T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
return true;
// C++14 [meta.unary.prop]:
// For incomplete types and function types, is_destructible<T>::value is
// false.
if (T->isIncompleteType() || T->isFunctionType())
return false;
// C++14 [meta.unary.prop]:
// For object types and given U equal to remove_all_extents_t<T>, if the
// expression std::declval<U&>().~U() is well-formed when treated as an
// unevaluated operand (Clause 5), then is_destructible<T>::value is true
if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
CXXDestructorDecl *Destructor = Self.LookupDestructor(RD);
if (!Destructor)
return false;
// C++14 [dcl.fct.def.delete]p2:
// A program that refers to a deleted function implicitly or
// explicitly, other than to declare it, is ill-formed.
if (Destructor->isDeleted())
return false;
if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public)
return false;
if (UTT == UTT_IsNothrowDestructible) {
const FunctionProtoType *CPT =
Destructor->getType()->getAs<FunctionProtoType>();
CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
if (!CPT || !CPT->isNothrow(C))
return false;
}
}
return true;
case UTT_HasTrivialDestructor:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
// If __is_pod (type) is true or type is a reference type
// then the trait is true, else if type is a cv class or union
// type (or array thereof) with a trivial destructor
// ([class.dtor]) then the trait is true, else it is
// false.
if (T.isPODType(C) || T->isReferenceType())
return true;
// Objective-C++ ARC: autorelease types don't require destruction.
if (T->isObjCLifetimeType() &&
T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing)
return true;
if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl())
return RD->hasTrivialDestructor();
return false;
// TODO: Propagate nothrowness for implicitly declared special members.
case UTT_HasNothrowAssign:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If type is const qualified or is a reference type then the
// trait is false. Otherwise if __has_trivial_assign (type)
// is true then the trait is true, else if type is a cv class
// or union type with copy assignment operators that are known
// not to throw an exception then the trait is true, else it is
// false.
if (C.getBaseElementType(T).isConstQualified())
return false;
if (T->isReferenceType())
return false;
if (T.isPODType(C) || T->isObjCLifetimeType())
return true;
if (const RecordType *RT = T->getAs<RecordType>())
return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
&CXXRecordDecl::hasTrivialCopyAssignment,
&CXXRecordDecl::hasNonTrivialCopyAssignment,
&CXXMethodDecl::isCopyAssignmentOperator);
return false;
case UTT_HasNothrowMoveAssign:
// This trait is implemented by MSVC 2012 and needed to parse the
// standard library headers. Specifically this is used as the logic
// behind std::is_nothrow_move_assignable (20.9.4.3).
if (T.isPODType(C))
return true;
if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>())
return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C,
&CXXRecordDecl::hasTrivialMoveAssignment,
&CXXRecordDecl::hasNonTrivialMoveAssignment,
&CXXMethodDecl::isMoveAssignmentOperator);
return false;
case UTT_HasNothrowCopy:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If __has_trivial_copy (type) is true then the trait is true, else
// if type is a cv class or union type with copy constructors that are
// known not to throw an exception then the trait is true, else it is
// false.
if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType())
return true;
if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
if (RD->hasTrivialCopyConstructor() &&
!RD->hasNonTrivialCopyConstructor())
return true;
bool FoundConstructor = false;
unsigned FoundTQs;
for (const auto *ND : Self.LookupConstructors(RD)) {
// A template constructor is never a copy constructor.
// FIXME: However, it may actually be selected at the actual overload
// resolution point.
if (isa<FunctionTemplateDecl>(ND))
continue;
const CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(ND);
if (Constructor->isCopyConstructor(FoundTQs)) {
FoundConstructor = true;
const FunctionProtoType *CPT
= Constructor->getType()->getAs<FunctionProtoType>();
CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
if (!CPT)
return false;
// TODO: check whether evaluating default arguments can throw.
// For now, we'll be conservative and assume that they can throw.
if (!CPT->isNothrow(C) || CPT->getNumParams() > 1)
return false;
}
}
return FoundConstructor;
}
return false;
case UTT_HasNothrowConstructor:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
// If __has_trivial_constructor (type) is true then the trait is
// true, else if type is a cv class or union type (or array
// thereof) with a default constructor that is known not to
// throw an exception then the trait is true, else it is false.
if (T.isPODType(C) || T->isObjCLifetimeType())
return true;
if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) {
if (RD->hasTrivialDefaultConstructor() &&
!RD->hasNonTrivialDefaultConstructor())
return true;
bool FoundConstructor = false;
for (const auto *ND : Self.LookupConstructors(RD)) {
// FIXME: In C++0x, a constructor template can be a default constructor.
if (isa<FunctionTemplateDecl>(ND))
continue;
const CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(ND);
if (Constructor->isDefaultConstructor()) {
FoundConstructor = true;
const FunctionProtoType *CPT
= Constructor->getType()->getAs<FunctionProtoType>();
CPT = Self.ResolveExceptionSpec(KeyLoc, CPT);
if (!CPT)
return false;
// FIXME: check whether evaluating default arguments can throw.
// For now, we'll be conservative and assume that they can throw.
if (!CPT->isNothrow(C) || CPT->getNumParams() > 0)
return false;
}
}
return FoundConstructor;
}
return false;
case UTT_HasVirtualDestructor:
// http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html:
// If type is a class type with a virtual destructor ([class.dtor])
// then the trait is true, else it is false.
if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD))
return Destructor->isVirtual();
return false;
// These type trait expressions are modeled on the specifications for the
// Embarcadero C++0x type trait functions:
// http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index
case UTT_IsCompleteType:
// http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_):
// Returns True if and only if T is a complete type at the point of the
// function call.
return !T->isIncompleteType();
}
}
/// \brief Determine whether T has a non-trivial Objective-C lifetime in
/// ARC mode.
static bool hasNontrivialObjCLifetime(QualType T) {
switch (T.getObjCLifetime()) {
case Qualifiers::OCL_ExplicitNone:
return false;
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Weak:
case Qualifiers::OCL_Autoreleasing:
return true;
case Qualifiers::OCL_None:
return T->isObjCLifetimeType();
}
llvm_unreachable("Unknown ObjC lifetime qualifier");
}
static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
QualType RhsT, SourceLocation KeyLoc);
static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc,
ArrayRef<TypeSourceInfo *> Args,
SourceLocation RParenLoc) {
if (Kind <= UTT_Last)
return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType());
if (Kind <= BTT_Last)
return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(),
Args[1]->getType(), RParenLoc);
switch (Kind) {
case clang::TT_IsConstructible:
case clang::TT_IsNothrowConstructible:
case clang::TT_IsTriviallyConstructible: {
// C++11 [meta.unary.prop]:
// is_trivially_constructible is defined as:
//
// is_constructible<T, Args...>::value is true and the variable
// definition for is_constructible, as defined below, is known to call
// no operation that is not trivial.
//
// The predicate condition for a template specialization
// is_constructible<T, Args...> shall be satisfied if and only if the
// following variable definition would be well-formed for some invented
// variable t:
//
// T t(create<Args>()...);
assert(!Args.empty());
// Precondition: T and all types in the parameter pack Args shall be
// complete types, (possibly cv-qualified) void, or arrays of
// unknown bound.
for (const auto *TSI : Args) {
QualType ArgTy = TSI->getType();
if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType())
continue;
if (S.RequireCompleteType(KWLoc, ArgTy,
diag::err_incomplete_type_used_in_type_trait_expr))
return false;
}
// Make sure the first argument is not incomplete nor a function type.
QualType T = Args[0]->getType();
if (T->isIncompleteType() || T->isFunctionType())
return false;
// Make sure the first argument is not an abstract type.
CXXRecordDecl *RD = T->getAsCXXRecordDecl();
if (RD && RD->isAbstract())
return false;
SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs;
SmallVector<Expr *, 2> ArgExprs;
ArgExprs.reserve(Args.size() - 1);
for (unsigned I = 1, N = Args.size(); I != N; ++I) {
QualType ArgTy = Args[I]->getType();
if (ArgTy->isObjectType() || ArgTy->isFunctionType())
ArgTy = S.Context.getRValueReferenceType(ArgTy);
OpaqueArgExprs.push_back(
OpaqueValueExpr(Args[I]->getTypeLoc().getLocStart(),
ArgTy.getNonLValueExprType(S.Context),
Expr::getValueKindForType(ArgTy)));
}
for (Expr &E : OpaqueArgExprs)
ArgExprs.push_back(&E);
// Perform the initialization in an unevaluated context within a SFINAE
// trap at translation unit scope.
EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated);
Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true);
Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl());
InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0]));
InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc,
RParenLoc));
InitializationSequence Init(S, To, InitKind, ArgExprs);
if (Init.Failed())
return false;
ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs);
if (Result.isInvalid() || SFINAE.hasErrorOccurred())
return false;
if (Kind == clang::TT_IsConstructible)
return true;
if (Kind == clang::TT_IsNothrowConstructible)
return S.canThrow(Result.get()) == CT_Cannot;
if (Kind == clang::TT_IsTriviallyConstructible) {
// Under Objective-C ARC, if the destination has non-trivial Objective-C
// lifetime, this is a non-trivial construction.
if (S.getLangOpts().ObjCAutoRefCount &&
hasNontrivialObjCLifetime(T.getNonReferenceType()))
return false;
// The initialization succeeded; now make sure there are no non-trivial
// calls.
return !Result.get()->hasNonTrivialCall(S.Context);
}
llvm_unreachable("unhandled type trait");
return false;
}
default: llvm_unreachable("not a TT");
}
return false;
}
ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
ArrayRef<TypeSourceInfo *> Args,
SourceLocation RParenLoc) {
QualType ResultType = Context.getLogicalOperationType();
if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness(
*this, Kind, KWLoc, Args[0]->getType()))
return ExprError();
bool Dependent = false;
for (unsigned I = 0, N = Args.size(); I != N; ++I) {
if (Args[I]->getType()->isDependentType()) {
Dependent = true;
break;
}
}
bool Result = false;
if (!Dependent)
Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc);
return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args,
RParenLoc, Result);
}
ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
ArrayRef<ParsedType> Args,
SourceLocation RParenLoc) {
SmallVector<TypeSourceInfo *, 4> ConvertedArgs;
ConvertedArgs.reserve(Args.size());
for (unsigned I = 0, N = Args.size(); I != N; ++I) {
TypeSourceInfo *TInfo;
QualType T = GetTypeFromParser(Args[I], &TInfo);
if (!TInfo)
TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc);
ConvertedArgs.push_back(TInfo);
}
return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc);
}
static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
QualType RhsT, SourceLocation KeyLoc) {
assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&
"Cannot evaluate traits of dependent types");
switch(BTT) {
case BTT_IsBaseOf: {
// C++0x [meta.rel]p2
// Base is a base class of Derived without regard to cv-qualifiers or
// Base and Derived are not unions and name the same class type without
// regard to cv-qualifiers.
const RecordType *lhsRecord = LhsT->getAs<RecordType>();
if (!lhsRecord) return false;
const RecordType *rhsRecord = RhsT->getAs<RecordType>();
if (!rhsRecord) return false;
assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
== (lhsRecord == rhsRecord));
if (lhsRecord == rhsRecord)
return !lhsRecord->getDecl()->isUnion();
// C++0x [meta.rel]p2:
// If Base and Derived are class types and are different types
// (ignoring possible cv-qualifiers) then Derived shall be a
// complete type.
if (Self.RequireCompleteType(KeyLoc, RhsT,
diag::err_incomplete_type_used_in_type_trait_expr))
return false;
return cast<CXXRecordDecl>(rhsRecord->getDecl())
->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl()));
}
case BTT_IsSame:
return Self.Context.hasSameType(LhsT, RhsT);
case BTT_TypeCompatible:
return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(),
RhsT.getUnqualifiedType());
case BTT_IsConvertible:
case BTT_IsConvertibleTo: {
// C++0x [meta.rel]p4:
// Given the following function prototype:
//
// template <class T>
// typename add_rvalue_reference<T>::type create();
//
// the predicate condition for a template specialization
// is_convertible<From, To> shall be satisfied if and only if
// the return expression in the following code would be
// well-formed, including any implicit conversions to the return
// type of the function:
//
// To test() {
// return create<From>();
// }
//
// Access checking is performed as if in a context unrelated to To and
// From. Only the validity of the immediate context of the expression
// of the return-statement (including conversions to the return type)
// is considered.
//
// We model the initialization as a copy-initialization of a temporary
// of the appropriate type, which for this expression is identical to the
// return statement (since NRVO doesn't apply).
// Functions aren't allowed to return function or array types.
if (RhsT->isFunctionType() || RhsT->isArrayType())
return false;
// A return statement in a void function must have void type.
if (RhsT->isVoidType())
return LhsT->isVoidType();
// A function definition requires a complete, non-abstract return type.
if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT))
return false;
// Compute the result of add_rvalue_reference.
if (LhsT->isObjectType() || LhsT->isFunctionType())
LhsT = Self.Context.getRValueReferenceType(LhsT);
// Build a fake source and destination for initialization.
InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT));
OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
Expr::getValueKindForType(LhsT));
Expr *FromPtr = &From;
InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc,
SourceLocation()));
// Perform the initialization in an unevaluated context within a SFINAE
// trap at translation unit scope.
EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
InitializationSequence Init(Self, To, Kind, FromPtr);
if (Init.Failed())
return false;
ExprResult Result = Init.Perform(Self, To, Kind, FromPtr);
return !Result.isInvalid() && !SFINAE.hasErrorOccurred();
}
case BTT_IsNothrowAssignable:
case BTT_IsTriviallyAssignable: {
// C++11 [meta.unary.prop]p3:
// is_trivially_assignable is defined as:
// is_assignable<T, U>::value is true and the assignment, as defined by
// is_assignable, is known to call no operation that is not trivial
//
// is_assignable is defined as:
// The expression declval<T>() = declval<U>() is well-formed when
// treated as an unevaluated operand (Clause 5).
//
// For both, T and U shall be complete types, (possibly cv-qualified)
// void, or arrays of unknown bound.
if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() &&
Self.RequireCompleteType(KeyLoc, LhsT,
diag::err_incomplete_type_used_in_type_trait_expr))
return false;
if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() &&
Self.RequireCompleteType(KeyLoc, RhsT,
diag::err_incomplete_type_used_in_type_trait_expr))
return false;
// cv void is never assignable.
if (LhsT->isVoidType() || RhsT->isVoidType())
return false;
// Build expressions that emulate the effect of declval<T>() and
// declval<U>().
if (LhsT->isObjectType() || LhsT->isFunctionType())
LhsT = Self.Context.getRValueReferenceType(LhsT);
if (RhsT->isObjectType() || RhsT->isFunctionType())
RhsT = Self.Context.getRValueReferenceType(RhsT);
OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context),
Expr::getValueKindForType(LhsT));
OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context),
Expr::getValueKindForType(RhsT));
// Attempt the assignment in an unevaluated context within a SFINAE
// trap at translation unit scope.
EnterExpressionEvaluationContext Unevaluated(Self, Sema::Unevaluated);
Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true);
Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl());
ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs,
&Rhs);
if (Result.isInvalid() || SFINAE.hasErrorOccurred())
return false;
if (BTT == BTT_IsNothrowAssignable)
return Self.canThrow(Result.get()) == CT_Cannot;
if (BTT == BTT_IsTriviallyAssignable) {
// Under Objective-C ARC, if the destination has non-trivial Objective-C
// lifetime, this is a non-trivial assignment.
if (Self.getLangOpts().ObjCAutoRefCount &&
hasNontrivialObjCLifetime(LhsT.getNonReferenceType()))
return false;
return !Result.get()->hasNonTrivialCall(Self.Context);
}
llvm_unreachable("unhandled type trait");
return false;
}
default: llvm_unreachable("not a BTT");
}
llvm_unreachable("Unknown type trait or not implemented");
}
ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT,
SourceLocation KWLoc,
ParsedType Ty,
Expr* DimExpr,
SourceLocation RParen) {
TypeSourceInfo *TSInfo;
QualType T = GetTypeFromParser(Ty, &TSInfo);
if (!TSInfo)
TSInfo = Context.getTrivialTypeSourceInfo(T);
return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen);
}
static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT,
QualType T, Expr *DimExpr,
SourceLocation KeyLoc) {
assert(!T->isDependentType() && "Cannot evaluate traits of dependent type");
switch(ATT) {
case ATT_ArrayRank:
if (T->isArrayType()) {
unsigned Dim = 0;
while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
++Dim;
T = AT->getElementType();
}
return Dim;
}
return 0;
case ATT_ArrayExtent: {
llvm::APSInt Value;
uint64_t Dim;
if (Self.VerifyIntegerConstantExpression(DimExpr, &Value,
diag::err_dimension_expr_not_constant_integer,
false).isInvalid())
return 0;
if (Value.isSigned() && Value.isNegative()) {
Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer)
<< DimExpr->getSourceRange();
return 0;
}
Dim = Value.getLimitedValue();
if (T->isArrayType()) {
unsigned D = 0;
bool Matched = false;
while (const ArrayType *AT = Self.Context.getAsArrayType(T)) {
if (Dim == D) {
Matched = true;
break;
}
++D;
T = AT->getElementType();
}
if (Matched && T->isArrayType()) {
if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T))
return CAT->getSize().getLimitedValue();
}
}
return 0;
}
}
llvm_unreachable("Unknown type trait or not implemented");
}
ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT,
SourceLocation KWLoc,
TypeSourceInfo *TSInfo,
Expr* DimExpr,
SourceLocation RParen) {
QualType T = TSInfo->getType();
// FIXME: This should likely be tracked as an APInt to remove any host
// assumptions about the width of size_t on the target.
uint64_t Value = 0;
if (!T->isDependentType())
Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc);
// While the specification for these traits from the Embarcadero C++
// compiler's documentation says the return type is 'unsigned int', Clang
// returns 'size_t'. On Windows, the primary platform for the Embarcadero
// compiler, there is no difference. On several other platforms this is an
// important distinction.
return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr,
RParen, Context.getSizeType());
}
ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET,
SourceLocation KWLoc,
Expr *Queried,
SourceLocation RParen) {
// If error parsing the expression, ignore.
if (!Queried)
return ExprError();
ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen);
return Result;
}
static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) {
switch (ET) {
case ET_IsLValueExpr: return E->isLValue();
case ET_IsRValueExpr: return E->isRValue();
}
llvm_unreachable("Expression trait not covered by switch");
}
ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET,
SourceLocation KWLoc,
Expr *Queried,
SourceLocation RParen) {
if (Queried->isTypeDependent()) {
// Delay type-checking for type-dependent expressions.
} else if (Queried->getType()->isPlaceholderType()) {
ExprResult PE = CheckPlaceholderExpr(Queried);
if (PE.isInvalid()) return ExprError();
return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen);
}
bool Value = EvaluateExpressionTrait(ET, Queried);
return new (Context)
ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy);
}
QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS,
ExprValueKind &VK,
SourceLocation Loc,
bool isIndirect) {
assert(!LHS.get()->getType()->isPlaceholderType() &&
!RHS.get()->getType()->isPlaceholderType() &&
"placeholders should have been weeded out by now");
// The LHS undergoes lvalue conversions if this is ->*.
if (isIndirect) {
LHS = DefaultLvalueConversion(LHS.get());
if (LHS.isInvalid()) return QualType();
}
// The RHS always undergoes lvalue conversions.
RHS = DefaultLvalueConversion(RHS.get());
if (RHS.isInvalid()) return QualType();
const char *OpSpelling = isIndirect ? "->*" : ".*";
// C++ 5.5p2
// The binary operator .* [p3: ->*] binds its second operand, which shall
// be of type "pointer to member of T" (where T is a completely-defined
// class type) [...]
QualType RHSType = RHS.get()->getType();
const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>();
if (!MemPtr) {
Diag(Loc, diag::err_bad_memptr_rhs)
<< OpSpelling << RHSType << RHS.get()->getSourceRange();
return QualType();
}
QualType Class(MemPtr->getClass(), 0);
// Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the
// member pointer points must be completely-defined. However, there is no
// reason for this semantic distinction, and the rule is not enforced by
// other compilers. Therefore, we do not check this property, as it is
// likely to be considered a defect.
// C++ 5.5p2
// [...] to its first operand, which shall be of class T or of a class of
// which T is an unambiguous and accessible base class. [p3: a pointer to
// such a class]
QualType LHSType = LHS.get()->getType();
if (isIndirect) {
if (const PointerType *Ptr = LHSType->getAs<PointerType>())
LHSType = Ptr->getPointeeType();
else {
Diag(Loc, diag::err_bad_memptr_lhs)
<< OpSpelling << 1 << LHSType
<< FixItHint::CreateReplacement(SourceRange(Loc), ".*");
return QualType();
}
}
if (!Context.hasSameUnqualifiedType(Class, LHSType)) {
// If we want to check the hierarchy, we need a complete type.
if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs,
OpSpelling, (int)isIndirect)) {
return QualType();
}
if (!IsDerivedFrom(Loc, LHSType, Class)) {
Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
<< (int)isIndirect << LHS.get()->getType();
return QualType();
}
CXXCastPath BasePath;
if (CheckDerivedToBaseConversion(LHSType, Class, Loc,
SourceRange(LHS.get()->getLocStart(),
RHS.get()->getLocEnd()),
&BasePath))
return QualType();
// Cast LHS to type of use.
QualType UseType = isIndirect ? Context.getPointerType(Class) : Class;
ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind();
LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK,
&BasePath);
}
if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) {
// Diagnose use of pointer-to-member type which when used as
// the functional cast in a pointer-to-member expression.
Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
return QualType();
}
// C++ 5.5p2
// The result is an object or a function of the type specified by the
// second operand.
// The cv qualifiers are the union of those in the pointer and the left side,
// in accordance with 5.5p5 and 5.2.5.
QualType Result = MemPtr->getPointeeType();
Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers());
// C++0x [expr.mptr.oper]p6:
// In a .* expression whose object expression is an rvalue, the program is
// ill-formed if the second operand is a pointer to member function with
// ref-qualifier &. In a ->* expression or in a .* expression whose object
// expression is an lvalue, the program is ill-formed if the second operand
// is a pointer to member function with ref-qualifier &&.
if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) {
switch (Proto->getRefQualifier()) {
case RQ_None:
// Do nothing
break;
case RQ_LValue:
if (!isIndirect && !LHS.get()->Classify(Context).isLValue())
Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
<< RHSType << 1 << LHS.get()->getSourceRange();
break;
case RQ_RValue:
if (isIndirect || !LHS.get()->Classify(Context).isRValue())
Diag(Loc, diag::err_pointer_to_member_oper_value_classify)
<< RHSType << 0 << LHS.get()->getSourceRange();
break;
}
}
// C++ [expr.mptr.oper]p6:
// The result of a .* expression whose second operand is a pointer
// to a data member is of the same value category as its
// first operand. The result of a .* expression whose second
// operand is a pointer to a member function is a prvalue. The
// result of an ->* expression is an lvalue if its second operand
// is a pointer to data member and a prvalue otherwise.
if (Result->isFunctionType()) {
VK = VK_RValue;
return Context.BoundMemberTy;
} else if (isIndirect) {
VK = VK_LValue;
} else {
VK = LHS.get()->getValueKind();
}
return Result;
}
/// \brief Try to convert a type to another according to C++0x 5.16p3.
///
/// This is part of the parameter validation for the ? operator. If either
/// value operand is a class type, the two operands are attempted to be
/// converted to each other. This function does the conversion in one direction.
/// It returns true if the program is ill-formed and has already been diagnosed
/// as such.
static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
SourceLocation QuestionLoc,
bool &HaveConversion,
QualType &ToType) {
HaveConversion = false;
ToType = To->getType();
InitializationKind Kind = InitializationKind::CreateCopy(To->getLocStart(),
SourceLocation());
// C++0x 5.16p3
// The process for determining whether an operand expression E1 of type T1
// can be converted to match an operand expression E2 of type T2 is defined
// as follows:
// -- If E2 is an lvalue:
bool ToIsLvalue = To->isLValue();
if (ToIsLvalue) {
// E1 can be converted to match E2 if E1 can be implicitly converted to
// type "lvalue reference to T2", subject to the constraint that in the
// conversion the reference must bind directly to E1.
QualType T = Self.Context.getLValueReferenceType(ToType);
InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
InitializationSequence InitSeq(Self, Entity, Kind, From);
if (InitSeq.isDirectReferenceBinding()) {
ToType = T;
HaveConversion = true;
return false;
}
if (InitSeq.isAmbiguous())
return InitSeq.Diagnose(Self, Entity, Kind, From);
}
// -- If E2 is an rvalue, or if the conversion above cannot be done:
// -- if E1 and E2 have class type, and the underlying class types are
// the same or one is a base class of the other:
QualType FTy = From->getType();
QualType TTy = To->getType();
const RecordType *FRec = FTy->getAs<RecordType>();
const RecordType *TRec = TTy->getAs<RecordType>();
bool FDerivedFromT = FRec && TRec && FRec != TRec &&
Self.IsDerivedFrom(QuestionLoc, FTy, TTy);
if (FRec && TRec && (FRec == TRec || FDerivedFromT ||
Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) {
// E1 can be converted to match E2 if the class of T2 is the
// same type as, or a base class of, the class of T1, and
// [cv2 > cv1].
if (FRec == TRec || FDerivedFromT) {
if (TTy.isAtLeastAsQualifiedAs(FTy)) {
InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
InitializationSequence InitSeq(Self, Entity, Kind, From);
if (InitSeq) {
HaveConversion = true;
return false;
}
if (InitSeq.isAmbiguous())
return InitSeq.Diagnose(Self, Entity, Kind, From);
}
}
return false;
}
// -- Otherwise: E1 can be converted to match E2 if E1 can be
// implicitly converted to the type that expression E2 would have
// if E2 were converted to an rvalue (or the type it has, if E2 is
// an rvalue).
//
// This actually refers very narrowly to the lvalue-to-rvalue conversion, not
// to the array-to-pointer or function-to-pointer conversions.
if (!TTy->getAs<TagType>())
TTy = TTy.getUnqualifiedType();
InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy);
InitializationSequence InitSeq(Self, Entity, Kind, From);
HaveConversion = !InitSeq.Failed();
ToType = TTy;
if (InitSeq.isAmbiguous())
return InitSeq.Diagnose(Self, Entity, Kind, From);
return false;
}
/// \brief Try to find a common type for two according to C++0x 5.16p5.
///
/// This is part of the parameter validation for the ? operator. If either
/// value operand is a class type, overload resolution is used to find a
/// conversion to a common type.
static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS,
SourceLocation QuestionLoc) {
Expr *Args[2] = { LHS.get(), RHS.get() };
OverloadCandidateSet CandidateSet(QuestionLoc,
OverloadCandidateSet::CSK_Operator);
Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args,
CandidateSet);
OverloadCandidateSet::iterator Best;
switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) {
case OR_Success: {
// We found a match. Perform the conversions on the arguments and move on.
ExprResult LHSRes =
Self.PerformImplicitConversion(LHS.get(), Best->BuiltinTypes.ParamTypes[0],
Best->Conversions[0], Sema::AA_Converting);
if (LHSRes.isInvalid())
break;
LHS = LHSRes;
ExprResult RHSRes =
Self.PerformImplicitConversion(RHS.get(), Best->BuiltinTypes.ParamTypes[1],
Best->Conversions[1], Sema::AA_Converting);
if (RHSRes.isInvalid())
break;
RHS = RHSRes;
if (Best->Function)
Self.MarkFunctionReferenced(QuestionLoc, Best->Function);
return false;
}
case OR_No_Viable_Function:
// Emit a better diagnostic if one of the expressions is a null pointer
// constant and the other is a pointer type. In this case, the user most
// likely forgot to take the address of the other expression.
if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
return true;
Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
<< LHS.get()->getType() << RHS.get()->getType()
<< LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return true;
case OR_Ambiguous:
Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl)
<< LHS.get()->getType() << RHS.get()->getType()
<< LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
// FIXME: Print the possible common types by printing the return types of
// the viable candidates.
break;
case OR_Deleted:
llvm_unreachable("Conditional operator has only built-in overloads");
}
return true;
}
/// \brief Perform an "extended" implicit conversion as returned by
/// TryClassUnification.
static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) {
InitializedEntity Entity = InitializedEntity::InitializeTemporary(T);
InitializationKind Kind = InitializationKind::CreateCopy(E.get()->getLocStart(),
SourceLocation());
Expr *Arg = E.get();
InitializationSequence InitSeq(Self, Entity, Kind, Arg);
ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg);
if (Result.isInvalid())
return true;
E = Result;
return false;
}
/// \brief Check the operands of ?: under C++ semantics.
///
/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
/// extension. In this case, LHS == Cond. (But they're not aliases.)
QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS,
ExprResult &RHS, ExprValueKind &VK,
ExprObjectKind &OK,
SourceLocation QuestionLoc) {
// FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++
// interface pointers.
// C++11 [expr.cond]p1
// The first expression is contextually converted to bool.
if (!Cond.get()->isTypeDependent()) {
ExprResult CondRes = CheckCXXBooleanCondition(Cond.get());
if (CondRes.isInvalid())
return QualType();
Cond = CondRes;
}
// Assume r-value.
VK = VK_RValue;
OK = OK_Ordinary;
// Either of the arguments dependent?
if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent())
return Context.DependentTy;
// C++11 [expr.cond]p2
// If either the second or the third operand has type (cv) void, ...
QualType LTy = LHS.get()->getType();
QualType RTy = RHS.get()->getType();
bool LVoid = LTy->isVoidType();
bool RVoid = RTy->isVoidType();
if (LVoid || RVoid) {
// ... one of the following shall hold:
// -- The second or the third operand (but not both) is a (possibly
// parenthesized) throw-expression; the result is of the type
// and value category of the other.
bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts());
bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts());
if (LThrow != RThrow) {
Expr *NonThrow = LThrow ? RHS.get() : LHS.get();
VK = NonThrow->getValueKind();
// DR (no number yet): the result is a bit-field if the
// non-throw-expression operand is a bit-field.
OK = NonThrow->getObjectKind();
return NonThrow->getType();
}
// -- Both the second and third operands have type void; the result is of
// type void and is a prvalue.
if (LVoid && RVoid)
return Context.VoidTy;
// Neither holds, error.
Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
<< (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
<< LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return QualType();
}
// Neither is void.
// C++11 [expr.cond]p3
// Otherwise, if the second and third operand have different types, and
// either has (cv) class type [...] an attempt is made to convert each of
// those operands to the type of the other.
if (!Context.hasSameType(LTy, RTy) &&
(LTy->isRecordType() || RTy->isRecordType())) {
// These return true if a single direction is already ambiguous.
QualType L2RType, R2LType;
bool HaveL2R, HaveR2L;
if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType))
return QualType();
if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType))
return QualType();
// If both can be converted, [...] the program is ill-formed.
if (HaveL2R && HaveR2L) {
Diag(QuestionLoc, diag::err_conditional_ambiguous)
<< LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return QualType();
}
// If exactly one conversion is possible, that conversion is applied to
// the chosen operand and the converted operands are used in place of the
// original operands for the remainder of this section.
if (HaveL2R) {
if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid())
return QualType();
LTy = LHS.get()->getType();
} else if (HaveR2L) {
if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid())
return QualType();
RTy = RHS.get()->getType();
}
}
// C++11 [expr.cond]p3
// if both are glvalues of the same value category and the same type except
// for cv-qualification, an attempt is made to convert each of those
// operands to the type of the other.
ExprValueKind LVK = LHS.get()->getValueKind();
ExprValueKind RVK = RHS.get()->getValueKind();
if (!Context.hasSameType(LTy, RTy) &&
Context.hasSameUnqualifiedType(LTy, RTy) &&
LVK == RVK && LVK != VK_RValue) {
// Since the unqualified types are reference-related and we require the
// result to be as if a reference bound directly, the only conversion
// we can perform is to add cv-qualifiers.
Qualifiers LCVR = Qualifiers::fromCVRMask(LTy.getCVRQualifiers());
Qualifiers RCVR = Qualifiers::fromCVRMask(RTy.getCVRQualifiers());
if (RCVR.isStrictSupersetOf(LCVR)) {
LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK);
LTy = LHS.get()->getType();
}
else if (LCVR.isStrictSupersetOf(RCVR)) {
RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK);
RTy = RHS.get()->getType();
}
}
// C++11 [expr.cond]p4
// If the second and third operands are glvalues of the same value
// category and have the same type, the result is of that type and
// value category and it is a bit-field if the second or the third
// operand is a bit-field, or if both are bit-fields.
// We only extend this to bitfields, not to the crazy other kinds of
// l-values.
bool Same = Context.hasSameType(LTy, RTy);
if (Same && LVK == RVK && LVK != VK_RValue &&
LHS.get()->isOrdinaryOrBitFieldObject() &&
RHS.get()->isOrdinaryOrBitFieldObject()) {
VK = LHS.get()->getValueKind();
if (LHS.get()->getObjectKind() == OK_BitField ||
RHS.get()->getObjectKind() == OK_BitField)
OK = OK_BitField;
return LTy;
}
// C++11 [expr.cond]p5
// Otherwise, the result is a prvalue. If the second and third operands
// do not have the same type, and either has (cv) class type, ...
if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
// ... overload resolution is used to determine the conversions (if any)
// to be applied to the operands. If the overload resolution fails, the
// program is ill-formed.
if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
return QualType();
}
// C++11 [expr.cond]p6
// Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
// conversions are performed on the second and third operands.
LHS = DefaultFunctionArrayLvalueConversion(LHS.get());
RHS = DefaultFunctionArrayLvalueConversion(RHS.get());
if (LHS.isInvalid() || RHS.isInvalid())
return QualType();
LTy = LHS.get()->getType();
RTy = RHS.get()->getType();
// After those conversions, one of the following shall hold:
// -- The second and third operands have the same type; the result
// is of that type. If the operands have class type, the result
// is a prvalue temporary of the result type, which is
// copy-initialized from either the second operand or the third
// operand depending on the value of the first operand.
if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) {
if (LTy->isRecordType()) {
// The operands have class type. Make a temporary copy.
if (RequireNonAbstractType(QuestionLoc, LTy,
diag::err_allocation_of_abstract_type))
return QualType();
InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy);
ExprResult LHSCopy = PerformCopyInitialization(Entity,
SourceLocation(),
LHS);
if (LHSCopy.isInvalid())
return QualType();
ExprResult RHSCopy = PerformCopyInitialization(Entity,
SourceLocation(),
RHS);
if (RHSCopy.isInvalid())
return QualType();
LHS = LHSCopy;
RHS = RHSCopy;
}
return LTy;
}
// Extension: conditional operator involving vector types.
if (LTy->isVectorType() || RTy->isVectorType())
return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false,
/*AllowBothBool*/true,
/*AllowBoolConversions*/false);
// -- The second and third operands have arithmetic or enumeration type;
// the usual arithmetic conversions are performed to bring them to a
// common type, and the result is of that type.
if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
QualType ResTy = UsualArithmeticConversions(LHS, RHS);
if (LHS.isInvalid() || RHS.isInvalid())
return QualType();
LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy));
RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy));
return ResTy;
}
// -- The second and third operands have pointer type, or one has pointer
// type and the other is a null pointer constant, or both are null
// pointer constants, at least one of which is non-integral; pointer
// conversions and qualification conversions are performed to bring them
// to their composite pointer type. The result is of the composite
// pointer type.
// -- The second and third operands have pointer to member type, or one has
// pointer to member type and the other is a null pointer constant;
// pointer to member conversions and qualification conversions are
// performed to bring them to a common type, whose cv-qualification
// shall match the cv-qualification of either the second or the third
// operand. The result is of the common type.
bool NonStandardCompositeType = false;
QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS,
isSFINAEContext() ? nullptr
: &NonStandardCompositeType);
if (!Composite.isNull()) {
if (NonStandardCompositeType)
Diag(QuestionLoc,
diag::ext_typecheck_cond_incompatible_operands_nonstandard)
<< LTy << RTy << Composite
<< LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return Composite;
}
// Similarly, attempt to find composite type of two objective-c pointers.
Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc);
if (!Composite.isNull())
return Composite;
// Check if we are using a null with a non-pointer type.
if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc))
return QualType();
Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
<< LHS.get()->getType() << RHS.get()->getType()
<< LHS.get()->getSourceRange() << RHS.get()->getSourceRange();
return QualType();
}
/// \brief Find a merged pointer type and convert the two expressions to it.
///
/// This finds the composite pointer type (or member pointer type) for @p E1
/// and @p E2 according to C++11 5.9p2. It converts both expressions to this
/// type and returns it.
/// It does not emit diagnostics.
///
/// \param Loc The location of the operator requiring these two expressions to
/// be converted to the composite pointer type.
///
/// If \p NonStandardCompositeType is non-NULL, then we are permitted to find
/// a non-standard (but still sane) composite type to which both expressions
/// can be converted. When such a type is chosen, \c *NonStandardCompositeType
/// will be set true.
QualType Sema::FindCompositePointerType(SourceLocation Loc,
Expr *&E1, Expr *&E2,
bool *NonStandardCompositeType) {
if (NonStandardCompositeType)
*NonStandardCompositeType = false;
assert(getLangOpts().CPlusPlus && "This function assumes C++");
QualType T1 = E1->getType(), T2 = E2->getType();
// C++11 5.9p2
// Pointer conversions and qualification conversions are performed on
// pointer operands to bring them to their composite pointer type. If
// one operand is a null pointer constant, the composite pointer type is
// std::nullptr_t if the other operand is also a null pointer constant or,
// if the other operand is a pointer, the type of the other operand.
if (!T1->isAnyPointerType() && !T1->isMemberPointerType() &&
!T2->isAnyPointerType() && !T2->isMemberPointerType()) {
if (T1->isNullPtrType() &&
E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get();
return T1;
}
if (T2->isNullPtrType() &&
E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get();
return T2;
}
return QualType();
}
if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
if (T2->isMemberPointerType())
E1 = ImpCastExprToType(E1, T2, CK_NullToMemberPointer).get();
else
E1 = ImpCastExprToType(E1, T2, CK_NullToPointer).get();
return T2;
}
if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
if (T1->isMemberPointerType())
E2 = ImpCastExprToType(E2, T1, CK_NullToMemberPointer).get();
else
E2 = ImpCastExprToType(E2, T1, CK_NullToPointer).get();
return T1;
}
// Now both have to be pointers or member pointers.
if ((!T1->isPointerType() && !T1->isMemberPointerType()) ||
(!T2->isPointerType() && !T2->isMemberPointerType()))
return QualType();
// Otherwise, of one of the operands has type "pointer to cv1 void," then
// the other has type "pointer to cv2 T" and the composite pointer type is
// "pointer to cv12 void," where cv12 is the union of cv1 and cv2.
// Otherwise, the composite pointer type is a pointer type similar to the
// type of one of the operands, with a cv-qualification signature that is
// the union of the cv-qualification signatures of the operand types.
// In practice, the first part here is redundant; it's subsumed by the second.
// What we do here is, we build the two possible composite types, and try the
// conversions in both directions. If only one works, or if the two composite
// types are the same, we have succeeded.
// FIXME: extended qualifiers?
typedef SmallVector<unsigned, 4> QualifierVector;
QualifierVector QualifierUnion;
typedef SmallVector<std::pair<const Type *, const Type *>, 4>
ContainingClassVector;
ContainingClassVector MemberOfClass;
QualType Composite1 = Context.getCanonicalType(T1),
Composite2 = Context.getCanonicalType(T2);
unsigned NeedConstBefore = 0;
do {
const PointerType *Ptr1, *Ptr2;
if ((Ptr1 = Composite1->getAs<PointerType>()) &&
(Ptr2 = Composite2->getAs<PointerType>())) {
Composite1 = Ptr1->getPointeeType();
Composite2 = Ptr2->getPointeeType();
// If we're allowed to create a non-standard composite type, keep track
// of where we need to fill in additional 'const' qualifiers.
if (NonStandardCompositeType &&
Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers())
NeedConstBefore = QualifierUnion.size();
QualifierUnion.push_back(
Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
MemberOfClass.push_back(std::make_pair(nullptr, nullptr));
continue;
}
const MemberPointerType *MemPtr1, *MemPtr2;
if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
(MemPtr2 = Composite2->getAs<MemberPointerType>())) {
Composite1 = MemPtr1->getPointeeType();
Composite2 = MemPtr2->getPointeeType();
// If we're allowed to create a non-standard composite type, keep track
// of where we need to fill in additional 'const' qualifiers.
if (NonStandardCompositeType &&
Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers())
NeedConstBefore = QualifierUnion.size();
QualifierUnion.push_back(
Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(),
MemPtr2->getClass()));
continue;
}
// FIXME: block pointer types?
// Cannot unwrap any more types.
break;
} while (true);
if (NeedConstBefore && NonStandardCompositeType) {
// Extension: Add 'const' to qualifiers that come before the first qualifier
// mismatch, so that our (non-standard!) composite type meets the
// requirements of C++ [conv.qual]p4 bullet 3.
for (unsigned I = 0; I != NeedConstBefore; ++I) {
if ((QualifierUnion[I] & Qualifiers::Const) == 0) {
QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const;
*NonStandardCompositeType = true;
}
}
}
// Rewrap the composites as pointers or member pointers with the union CVRs.
ContainingClassVector::reverse_iterator MOC
= MemberOfClass.rbegin();
for (QualifierVector::reverse_iterator
I = QualifierUnion.rbegin(),
E = QualifierUnion.rend();
I != E; (void)++I, ++MOC) {
Qualifiers Quals = Qualifiers::fromCVRMask(*I);
if (MOC->first && MOC->second) {
// Rebuild member pointer type
Composite1 = Context.getMemberPointerType(
Context.getQualifiedType(Composite1, Quals),
MOC->first);
Composite2 = Context.getMemberPointerType(
Context.getQualifiedType(Composite2, Quals),
MOC->second);
} else {
// Rebuild pointer type
Composite1
= Context.getPointerType(Context.getQualifiedType(Composite1, Quals));
Composite2
= Context.getPointerType(Context.getQualifiedType(Composite2, Quals));
}
}
// Try to convert to the first composite pointer type.
InitializedEntity Entity1
= InitializedEntity::InitializeTemporary(Composite1);
InitializationKind Kind
= InitializationKind::CreateCopy(Loc, SourceLocation());
InitializationSequence E1ToC1(*this, Entity1, Kind, E1);
InitializationSequence E2ToC1(*this, Entity1, Kind, E2);
if (E1ToC1 && E2ToC1) {
// Conversion to Composite1 is viable.
if (!Context.hasSameType(Composite1, Composite2)) {
// Composite2 is a different type from Composite1. Check whether
// Composite2 is also viable.
InitializedEntity Entity2
= InitializedEntity::InitializeTemporary(Composite2);
InitializationSequence E1ToC2(*this, Entity2, Kind, E1);
InitializationSequence E2ToC2(*this, Entity2, Kind, E2);
if (E1ToC2 && E2ToC2) {
// Both Composite1 and Composite2 are viable and are different;
// this is an ambiguity.
return QualType();
}
}
// Convert E1 to Composite1
ExprResult E1Result
= E1ToC1.Perform(*this, Entity1, Kind, E1);
if (E1Result.isInvalid())
return QualType();
E1 = E1Result.getAs<Expr>();
// Convert E2 to Composite1
ExprResult E2Result
= E2ToC1.Perform(*this, Entity1, Kind, E2);
if (E2Result.isInvalid())
return QualType();
E2 = E2Result.getAs<Expr>();
return Composite1;
}
// Check whether Composite2 is viable.
InitializedEntity Entity2
= InitializedEntity::InitializeTemporary(Composite2);
InitializationSequence E1ToC2(*this, Entity2, Kind, E1);
InitializationSequence E2ToC2(*this, Entity2, Kind, E2);
if (!E1ToC2 || !E2ToC2)
return QualType();
// Convert E1 to Composite2
ExprResult E1Result
= E1ToC2.Perform(*this, Entity2, Kind, E1);
if (E1Result.isInvalid())
return QualType();
E1 = E1Result.getAs<Expr>();
// Convert E2 to Composite2
ExprResult E2Result
= E2ToC2.Perform(*this, Entity2, Kind, E2);
if (E2Result.isInvalid())
return QualType();
E2 = E2Result.getAs<Expr>();
return Composite2;
}
ExprResult Sema::MaybeBindToTemporary(Expr *E) {
if (!E)
return ExprError();
assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?");
// If the result is a glvalue, we shouldn't bind it.
if (!E->isRValue())
return E;
// In ARC, calls that return a retainable type can return retained,
// in which case we have to insert a consuming cast.
if (getLangOpts().ObjCAutoRefCount &&
E->getType()->isObjCRetainableType()) {
bool ReturnsRetained;
// For actual calls, we compute this by examining the type of the
// called value.
if (CallExpr *Call = dyn_cast<CallExpr>(E)) {
Expr *Callee = Call->getCallee()->IgnoreParens();
QualType T = Callee->getType();
if (T == Context.BoundMemberTy) {
// Handle pointer-to-members.
if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee))
T = BinOp->getRHS()->getType();
else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee))
T = Mem->getMemberDecl()->getType();
}
if (const PointerType *Ptr = T->getAs<PointerType>())
T = Ptr->getPointeeType();
else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>())
T = Ptr->getPointeeType();
else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>())
T = MemPtr->getPointeeType();
const FunctionType *FTy = T->getAs<FunctionType>();
assert(FTy && "call to value not of function type?");
ReturnsRetained = FTy->getExtInfo().getProducesResult();
// ActOnStmtExpr arranges things so that StmtExprs of retainable
// type always produce a +1 object.
} else if (isa<StmtExpr>(E)) {
ReturnsRetained = true;
// We hit this case with the lambda conversion-to-block optimization;
// we don't want any extra casts here.
} else if (isa<CastExpr>(E) &&
isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) {
return E;
// For message sends and property references, we try to find an
// actual method. FIXME: we should infer retention by selector in
// cases where we don't have an actual method.
} else {
ObjCMethodDecl *D = nullptr;
if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) {
D = Send->getMethodDecl();
} else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) {
D = BoxedExpr->getBoxingMethod();
} else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) {
D = ArrayLit->getArrayWithObjectsMethod();
} else if (ObjCDictionaryLiteral *DictLit
= dyn_cast<ObjCDictionaryLiteral>(E)) {
D = DictLit->getDictWithObjectsMethod();
}
ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>());
// Don't do reclaims on performSelector calls; despite their
// return type, the invoked method doesn't necessarily actually
// return an object.
if (!ReturnsRetained &&
D && D->getMethodFamily() == OMF_performSelector)
return E;
}
// Don't reclaim an object of Class type.
if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType())
return E;
ExprNeedsCleanups = true;
CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject
: CK_ARCReclaimReturnedObject);
return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr,
VK_RValue);
}
if (!getLangOpts().CPlusPlus)
return E;
// Search for the base element type (cf. ASTContext::getBaseElementType) with
// a fast path for the common case that the type is directly a RecordType.
const Type *T = Context.getCanonicalType(E->getType().getTypePtr());
const RecordType *RT = nullptr;
while (!RT) {
switch (T->getTypeClass()) {
case Type::Record:
RT = cast<RecordType>(T);
break;
case Type::ConstantArray:
case Type::IncompleteArray:
case Type::VariableArray:
case Type::DependentSizedArray:
T = cast<ArrayType>(T)->getElementType().getTypePtr();
break;
default:
return E;
}
}
// That should be enough to guarantee that this type is complete, if we're
// not processing a decltype expression.
CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if (RD->isInvalidDecl() || RD->isDependentContext())
return E;
bool IsDecltype = ExprEvalContexts.back().IsDecltype;
CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD);
if (Destructor) {
MarkFunctionReferenced(E->getExprLoc(), Destructor);
CheckDestructorAccess(E->getExprLoc(), Destructor,
PDiag(diag::err_access_dtor_temp)
<< E->getType());
if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
return ExprError();
// If destructor is trivial, we can avoid the extra copy.
if (Destructor->isTrivial())
return E;
// We need a cleanup, but we don't need to remember the temporary.
ExprNeedsCleanups = true;
}
CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor);
CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E);
if (IsDecltype)
ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind);
return Bind;
}
ExprResult
Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) {
if (SubExpr.isInvalid())
return ExprError();
return MaybeCreateExprWithCleanups(SubExpr.get());
}
Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) {
assert(SubExpr && "subexpression can't be null!");
CleanupVarDeclMarking();
unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects;
assert(ExprCleanupObjects.size() >= FirstCleanup);
assert(ExprNeedsCleanups || ExprCleanupObjects.size() == FirstCleanup);
if (!ExprNeedsCleanups)
return SubExpr;
auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup,
ExprCleanupObjects.size() - FirstCleanup);
Expr *E = ExprWithCleanups::Create(Context, SubExpr, Cleanups);
DiscardCleanupsInEvaluationContext();
return E;
}
Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) {
assert(SubStmt && "sub-statement can't be null!");
CleanupVarDeclMarking();
if (!ExprNeedsCleanups)
return SubStmt;
// FIXME: In order to attach the temporaries, wrap the statement into
// a StmtExpr; currently this is only used for asm statements.
// This is hacky, either create a new CXXStmtWithTemporaries statement or
// a new AsmStmtWithTemporaries.
CompoundStmt *CompStmt = new (Context) CompoundStmt(Context, SubStmt,
SourceLocation(),
SourceLocation());
Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(),
SourceLocation());
return MaybeCreateExprWithCleanups(E);
}
/// Process the expression contained within a decltype. For such expressions,
/// certain semantic checks on temporaries are delayed until this point, and
/// are omitted for the 'topmost' call in the decltype expression. If the
/// topmost call bound a temporary, strip that temporary off the expression.
ExprResult Sema::ActOnDecltypeExpression(Expr *E) {
assert(ExprEvalContexts.back().IsDecltype && "not in a decltype expression");
// C++11 [expr.call]p11:
// If a function call is a prvalue of object type,
// -- if the function call is either
// -- the operand of a decltype-specifier, or
// -- the right operand of a comma operator that is the operand of a
// decltype-specifier,
// a temporary object is not introduced for the prvalue.
// Recursively rebuild ParenExprs and comma expressions to strip out the
// outermost CXXBindTemporaryExpr, if any.
if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr());
if (SubExpr.isInvalid())
return ExprError();
if (SubExpr.get() == PE->getSubExpr())
return E;
return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get());
}
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
if (BO->getOpcode() == BO_Comma) {
ExprResult RHS = ActOnDecltypeExpression(BO->getRHS());
if (RHS.isInvalid())
return ExprError();
if (RHS.get() == BO->getRHS())
return E;
return new (Context) BinaryOperator(
BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(),
BO->getObjectKind(), BO->getOperatorLoc(), BO->isFPContractable());
}
}
CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E);
CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr())
: nullptr;
if (TopCall)
E = TopCall;
else
TopBind = nullptr;
// Disable the special decltype handling now.
ExprEvalContexts.back().IsDecltype = false;
// In MS mode, don't perform any extra checking of call return types within a
// decltype expression.
if (getLangOpts().MSVCCompat)
return E;
// Perform the semantic checks we delayed until this point.
for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size();
I != N; ++I) {
CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I];
if (Call == TopCall)
continue;
if (CheckCallReturnType(Call->getCallReturnType(Context),
Call->getLocStart(),
Call, Call->getDirectCallee()))
return ExprError();
}
// Now all relevant types are complete, check the destructors are accessible
// and non-deleted, and annotate them on the temporaries.
for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size();
I != N; ++I) {
CXXBindTemporaryExpr *Bind =
ExprEvalContexts.back().DelayedDecltypeBinds[I];
if (Bind == TopBind)
continue;
CXXTemporary *Temp = Bind->getTemporary();
CXXRecordDecl *RD =
Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
CXXDestructorDecl *Destructor = LookupDestructor(RD);
Temp->setDestructor(Destructor);
MarkFunctionReferenced(Bind->getExprLoc(), Destructor);
CheckDestructorAccess(Bind->getExprLoc(), Destructor,
PDiag(diag::err_access_dtor_temp)
<< Bind->getType());
if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc()))
return ExprError();
// We need a cleanup, but we don't need to remember the temporary.
ExprNeedsCleanups = true;
}
// Possibly strip off the top CXXBindTemporaryExpr.
return E;
}
/// Note a set of 'operator->' functions that were used for a member access.
static void noteOperatorArrows(Sema &S,
ArrayRef<FunctionDecl *> OperatorArrows) {
unsigned SkipStart = OperatorArrows.size(), SkipCount = 0;
// FIXME: Make this configurable?
unsigned Limit = 9;
if (OperatorArrows.size() > Limit) {
// Produce Limit-1 normal notes and one 'skipping' note.
SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2;
SkipCount = OperatorArrows.size() - (Limit - 1);
}
for (unsigned I = 0; I < OperatorArrows.size(); /**/) {
if (I == SkipStart) {
S.Diag(OperatorArrows[I]->getLocation(),
diag::note_operator_arrows_suppressed)
<< SkipCount;
I += SkipCount;
} else {
S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here)
<< OperatorArrows[I]->getCallResultType();
++I;
}
}
}
ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base,
SourceLocation OpLoc,
tok::TokenKind OpKind,
ParsedType &ObjectType,
bool &MayBePseudoDestructor) {
// Since this might be a postfix expression, get rid of ParenListExprs.
ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base);
if (Result.isInvalid()) return ExprError();
Base = Result.get();
Result = CheckPlaceholderExpr(Base);
if (Result.isInvalid()) return ExprError();
Base = Result.get();
QualType BaseType = Base->getType();
MayBePseudoDestructor = false;
if (BaseType->isDependentType()) {
// If we have a pointer to a dependent type and are using the -> operator,
// the object type is the type that the pointer points to. We might still
// have enough information about that type to do something useful.
if (OpKind == tok::arrow)
if (const PointerType *Ptr = BaseType->getAs<PointerType>())
BaseType = Ptr->getPointeeType();
ObjectType = ParsedType::make(BaseType);
MayBePseudoDestructor = true;
return Base;
}
// C++ [over.match.oper]p8:
// [...] When operator->returns, the operator-> is applied to the value
// returned, with the original second operand.
if (OpKind == tok::arrow) {
QualType StartingType = BaseType;
bool NoArrowOperatorFound = false;
bool FirstIteration = true;
FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext);
// The set of types we've considered so far.
llvm::SmallPtrSet<CanQualType,8> CTypes;
SmallVector<FunctionDecl*, 8> OperatorArrows;
CTypes.insert(Context.getCanonicalType(BaseType));
while (BaseType->isRecordType()) {
if (OperatorArrows.size() >= getLangOpts().ArrowDepth) {
Diag(OpLoc, diag::err_operator_arrow_depth_exceeded)
<< StartingType << getLangOpts().ArrowDepth << Base->getSourceRange();
noteOperatorArrows(*this, OperatorArrows);
Diag(OpLoc, diag::note_operator_arrow_depth)
<< getLangOpts().ArrowDepth;
return ExprError();
}
Result = BuildOverloadedArrowExpr(
S, Base, OpLoc,
// When in a template specialization and on the first loop iteration,
// potentially give the default diagnostic (with the fixit in a
// separate note) instead of having the error reported back to here
// and giving a diagnostic with a fixit attached to the error itself.
(FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
? nullptr
: &NoArrowOperatorFound);
if (Result.isInvalid()) {
if (NoArrowOperatorFound) {
if (FirstIteration) {
Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
<< BaseType << 1 << Base->getSourceRange()
<< FixItHint::CreateReplacement(OpLoc, ".");
OpKind = tok::period;
break;
}
Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
<< BaseType << Base->getSourceRange();
CallExpr *CE = dyn_cast<CallExpr>(Base);
if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) {
Diag(CD->getLocStart(),
diag::note_member_reference_arrow_from_operator_arrow);
}
}
return ExprError();
}
Base = Result.get();
if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
OperatorArrows.push_back(OpCall->getDirectCallee());
BaseType = Base->getType();
CanQualType CBaseType = Context.getCanonicalType(BaseType);
if (!CTypes.insert(CBaseType).second) {
Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType;
noteOperatorArrows(*this, OperatorArrows);
return ExprError();
}
FirstIteration = false;
}
if (OpKind == tok::arrow &&
(BaseType->isPointerType() || BaseType->isObjCObjectPointerType()))
BaseType = BaseType->getPointeeType();
}
// Objective-C properties allow "." access on Objective-C pointer types,
// so adjust the base type to the object type itself.
if (BaseType->isObjCObjectPointerType())
BaseType = BaseType->getPointeeType();
// C++ [basic.lookup.classref]p2:
// [...] If the type of the object expression is of pointer to scalar
// type, the unqualified-id is looked up in the context of the complete
// postfix-expression.
//
// This also indicates that we could be parsing a pseudo-destructor-name.
// Note that Objective-C class and object types can be pseudo-destructor
// expressions or normal member (ivar or property) access expressions, and
// it's legal for the type to be incomplete if this is a pseudo-destructor
// call. We'll do more incomplete-type checks later in the lookup process,
// so just skip this check for ObjC types.
if (BaseType->isObjCObjectOrInterfaceType()) {
ObjectType = ParsedType::make(BaseType);
MayBePseudoDestructor = true;
return Base;
} else if (!BaseType->isRecordType()) {
ObjectType = nullptr;
MayBePseudoDestructor = true;
return Base;
}
// The object type must be complete (or dependent), or
// C++11 [expr.prim.general]p3:
// Unlike the object expression in other contexts, *this is not required to
// be of complete type for purposes of class member access (5.2.5) outside
// the member function body.
if (!BaseType->isDependentType() &&
!isThisOutsideMemberFunctionBody(BaseType) &&
RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access))
return ExprError();
// C++ [basic.lookup.classref]p2:
// If the id-expression in a class member access (5.2.5) is an
// unqualified-id, and the type of the object expression is of a class
// type C (or of pointer to a class type C), the unqualified-id is looked
// up in the scope of class C. [...]
ObjectType = ParsedType::make(BaseType);
return Base;
}
static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base,
tok::TokenKind& OpKind, SourceLocation OpLoc) {
if (Base->hasPlaceholderType()) {
ExprResult result = S.CheckPlaceholderExpr(Base);
if (result.isInvalid()) return true;
Base = result.get();
}
ObjectType = Base->getType();
// C++ [expr.pseudo]p2:
// The left-hand side of the dot operator shall be of scalar type. The
// left-hand side of the arrow operator shall be of pointer to scalar type.
// This scalar type is the object type.
// Note that this is rather different from the normal handling for the
// arrow operator.
if (OpKind == tok::arrow) {
if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) {
ObjectType = Ptr->getPointeeType();
} else if (!Base->isTypeDependent()) {
// The user wrote "p->" when she probably meant "p."; fix it.
S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
<< ObjectType << true
<< FixItHint::CreateReplacement(OpLoc, ".");
if (S.isSFINAEContext())
return true;
OpKind = tok::period;
}
}
return false;
}
ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base,
SourceLocation OpLoc,
tok::TokenKind OpKind,
const CXXScopeSpec &SS,
TypeSourceInfo *ScopeTypeInfo,
SourceLocation CCLoc,
SourceLocation TildeLoc,
PseudoDestructorTypeStorage Destructed) {
TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo();
QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
return ExprError();
if (!ObjectType->isDependentType() && !ObjectType->isScalarType() &&
!ObjectType->isVectorType()) {
if (getLangOpts().MSVCCompat && ObjectType->isVoidType())
Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange();
else {
Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar)
<< ObjectType << Base->getSourceRange();
return ExprError();
}
}
// C++ [expr.pseudo]p2:
// [...] The cv-unqualified versions of the object type and of the type
// designated by the pseudo-destructor-name shall be the same type.
if (DestructedTypeInfo) {
QualType DestructedType = DestructedTypeInfo->getType();
SourceLocation DestructedTypeStart
= DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) {
if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) {
Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch)
<< ObjectType << DestructedType << Base->getSourceRange()
<< DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
// Recover by setting the destructed type to the object type.
DestructedType = ObjectType;
DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
DestructedTypeStart);
Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
} else if (DestructedType.getObjCLifetime() !=
ObjectType.getObjCLifetime()) {
if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) {
// Okay: just pretend that the user provided the correctly-qualified
// type.
} else {
Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals)
<< ObjectType << DestructedType << Base->getSourceRange()
<< DestructedTypeInfo->getTypeLoc().getLocalSourceRange();
}
// Recover by setting the destructed type to the object type.
DestructedType = ObjectType;
DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType,
DestructedTypeStart);
Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
}
}
}
// C++ [expr.pseudo]p2:
// [...] Furthermore, the two type-names in a pseudo-destructor-name of the
// form
//
// ::[opt] nested-name-specifier[opt] type-name :: ~ type-name
//
// shall designate the same scalar type.
if (ScopeTypeInfo) {
QualType ScopeType = ScopeTypeInfo->getType();
if (!ScopeType->isDependentType() && !ObjectType->isDependentType() &&
!Context.hasSameUnqualifiedType(ScopeType, ObjectType)) {
Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(),
diag::err_pseudo_dtor_type_mismatch)
<< ObjectType << ScopeType << Base->getSourceRange()
<< ScopeTypeInfo->getTypeLoc().getLocalSourceRange();
ScopeType = QualType();
ScopeTypeInfo = nullptr;
}
}
Expr *Result
= new (Context) CXXPseudoDestructorExpr(Context, Base,
OpKind == tok::arrow, OpLoc,
SS.getWithLocInContext(Context),
ScopeTypeInfo,
CCLoc,
TildeLoc,
Destructed);
return Result;
}
ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
SourceLocation OpLoc,
tok::TokenKind OpKind,
CXXScopeSpec &SS,
UnqualifiedId &FirstTypeName,
SourceLocation CCLoc,
SourceLocation TildeLoc,
UnqualifiedId &SecondTypeName) {
assert((FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) &&
"Invalid first type name in pseudo-destructor");
assert((SecondTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) &&
"Invalid second type name in pseudo-destructor");
QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
return ExprError();
// Compute the object type that we should use for name lookup purposes. Only
// record types and dependent types matter.
ParsedType ObjectTypePtrForLookup;
if (!SS.isSet()) {
if (ObjectType->isRecordType())
ObjectTypePtrForLookup = ParsedType::make(ObjectType);
else if (ObjectType->isDependentType())
ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy);
}
// Convert the name of the type being destructed (following the ~) into a
// type (with source-location information).
QualType DestructedType;
TypeSourceInfo *DestructedTypeInfo = nullptr;
PseudoDestructorTypeStorage Destructed;
if (SecondTypeName.getKind() == UnqualifiedId::IK_Identifier) {
ParsedType T = getTypeName(*SecondTypeName.Identifier,
SecondTypeName.StartLocation,
S, &SS, true, false, ObjectTypePtrForLookup);
if (!T &&
((SS.isSet() && !computeDeclContext(SS, false)) ||
(!SS.isSet() && ObjectType->isDependentType()))) {
// The name of the type being destroyed is a dependent name, and we
// couldn't find anything useful in scope. Just store the identifier and
// it's location, and we'll perform (qualified) name lookup again at
// template instantiation time.
Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier,
SecondTypeName.StartLocation);
} else if (!T) {
Diag(SecondTypeName.StartLocation,
diag::err_pseudo_dtor_destructor_non_type)
<< SecondTypeName.Identifier << ObjectType;
if (isSFINAEContext())
return ExprError();
// Recover by assuming we had the right type all along.
DestructedType = ObjectType;
} else
DestructedType = GetTypeFromParser(T, &DestructedTypeInfo);
} else {
// Resolve the template-id to a type.
TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId;
ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
TemplateId->NumArgs);
TypeResult T = ActOnTemplateIdType(TemplateId->SS,
TemplateId->TemplateKWLoc,
TemplateId->Template,
TemplateId->TemplateNameLoc,
TemplateId->LAngleLoc,
TemplateArgsPtr,
TemplateId->RAngleLoc);
if (T.isInvalid() || !T.get()) {
// Recover by assuming we had the right type all along.
DestructedType = ObjectType;
} else
DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo);
}
// If we've performed some kind of recovery, (re-)build the type source
// information.
if (!DestructedType.isNull()) {
if (!DestructedTypeInfo)
DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType,
SecondTypeName.StartLocation);
Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo);
}
// Convert the name of the scope type (the type prior to '::') into a type.
TypeSourceInfo *ScopeTypeInfo = nullptr;
QualType ScopeType;
if (FirstTypeName.getKind() == UnqualifiedId::IK_TemplateId ||
FirstTypeName.Identifier) {
if (FirstTypeName.getKind() == UnqualifiedId::IK_Identifier) {
ParsedType T = getTypeName(*FirstTypeName.Identifier,
FirstTypeName.StartLocation,
S, &SS, true, false, ObjectTypePtrForLookup);
if (!T) {
Diag(FirstTypeName.StartLocation,
diag::err_pseudo_dtor_destructor_non_type)
<< FirstTypeName.Identifier << ObjectType;
if (isSFINAEContext())
return ExprError();
// Just drop this type. It's unnecessary anyway.
ScopeType = QualType();
} else
ScopeType = GetTypeFromParser(T, &ScopeTypeInfo);
} else {
// Resolve the template-id to a type.
TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId;
ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
TemplateId->NumArgs);
TypeResult T = ActOnTemplateIdType(TemplateId->SS,
TemplateId->TemplateKWLoc,
TemplateId->Template,
TemplateId->TemplateNameLoc,
TemplateId->LAngleLoc,
TemplateArgsPtr,
TemplateId->RAngleLoc);
if (T.isInvalid() || !T.get()) {
// Recover by dropping this type.
ScopeType = QualType();
} else
ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo);
}
}
if (!ScopeType.isNull() && !ScopeTypeInfo)
ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType,
FirstTypeName.StartLocation);
return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS,
ScopeTypeInfo, CCLoc, TildeLoc,
Destructed);
}
ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
SourceLocation OpLoc,
tok::TokenKind OpKind,
SourceLocation TildeLoc,
const DeclSpec& DS) {
QualType ObjectType;
if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc))
return ExprError();
QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(),
false);
TypeLocBuilder TLB;
DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T);
PseudoDestructorTypeStorage Destructed(DestructedTypeInfo);
return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(),
nullptr, SourceLocation(), TildeLoc,
Destructed);
}
ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl,
CXXConversionDecl *Method,
bool HadMultipleCandidates) {
if (Method->getParent()->isLambda() &&
Method->getConversionType()->isBlockPointerType()) {
// This is a lambda coversion to block pointer; check if the argument
// is a LambdaExpr.
Expr *SubE = E;
CastExpr *CE = dyn_cast<CastExpr>(SubE);
if (CE && CE->getCastKind() == CK_NoOp)
SubE = CE->getSubExpr();
SubE = SubE->IgnoreParens();
if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE))
SubE = BE->getSubExpr();
if (isa<LambdaExpr>(SubE)) {
// For the conversion to block pointer on a lambda expression, we
// construct a special BlockLiteral instead; this doesn't really make
// a difference in ARC, but outside of ARC the resulting block literal
// follows the normal lifetime rules for block literals instead of being
// autoreleased.
DiagnosticErrorTrap Trap(Diags);
ExprResult Exp = BuildBlockForLambdaConversion(E->getExprLoc(),
E->getExprLoc(),
Method, E);
if (Exp.isInvalid())
Diag(E->getExprLoc(), diag::note_lambda_to_block_conv);
return Exp;
}
}
ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr,
FoundDecl, Method);
if (Exp.isInvalid())
return true;
MemberExpr *ME = new (Context) MemberExpr(
Exp.get(), /*IsArrow=*/false, SourceLocation(), Method, SourceLocation(),
Context.BoundMemberTy, VK_RValue, OK_Ordinary);
if (HadMultipleCandidates)
ME->setHadMultipleCandidates(true);
MarkMemberReferenced(ME);
QualType ResultType = Method->getReturnType();
ExprValueKind VK = Expr::getValueKindForType(ResultType);
ResultType = ResultType.getNonLValueExprType(Context);
CXXMemberCallExpr *CE =
new (Context) CXXMemberCallExpr(Context, ME, None, ResultType, VK,
Exp.get()->getLocEnd());
return CE;
}
ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
SourceLocation RParen) {
// If the operand is an unresolved lookup expression, the expression is ill-
// formed per [over.over]p1, because overloaded function names cannot be used
// without arguments except in explicit contexts.
ExprResult R = CheckPlaceholderExpr(Operand);
if (R.isInvalid())
return R;
// The operand may have been modified when checking the placeholder type.
Operand = R.get();
if (ActiveTemplateInstantiations.empty() &&
Operand->HasSideEffects(Context, false)) {
// The expression operand for noexcept is in an unevaluated expression
// context, so side effects could result in unintended consequences.
Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context);
}
CanThrowResult CanThrow = canThrow(Operand);
return new (Context)
CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen);
}
ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation,
Expr *Operand, SourceLocation RParen) {
return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen);
}
static bool IsSpecialDiscardedValue(Expr *E) {
// In C++11, discarded-value expressions of a certain form are special,
// according to [expr]p10:
// The lvalue-to-rvalue conversion (4.1) is applied only if the
// expression is an lvalue of volatile-qualified type and it has
// one of the following forms:
E = E->IgnoreParens();
// - id-expression (5.1.1),
if (isa<DeclRefExpr>(E))
return true;
// - subscripting (5.2.1),
if (isa<ArraySubscriptExpr>(E))
return true;
// - class member access (5.2.5),
if (isa<MemberExpr>(E))
return true;
// - indirection (5.3.1),
if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E))
if (UO->getOpcode() == UO_Deref)
return true;
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
// - pointer-to-member operation (5.5),
if (BO->isPtrMemOp())
return true;
// - comma expression (5.18) where the right operand is one of the above.
if (BO->getOpcode() == BO_Comma)
return IsSpecialDiscardedValue(BO->getRHS());
}
// - conditional expression (5.16) where both the second and the third
// operands are one of the above, or
if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E))
return IsSpecialDiscardedValue(CO->getTrueExpr()) &&
IsSpecialDiscardedValue(CO->getFalseExpr());
// The related edge case of "*x ?: *x".
if (BinaryConditionalOperator *BCO =
dyn_cast<BinaryConditionalOperator>(E)) {
if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(BCO->getTrueExpr()))
return IsSpecialDiscardedValue(OVE->getSourceExpr()) &&
IsSpecialDiscardedValue(BCO->getFalseExpr());
}
// Objective-C++ extensions to the rule.
if (isa<PseudoObjectExpr>(E) || isa<ObjCIvarRefExpr>(E))
return true;
return false;
}
/// Perform the conversions required for an expression used in a
/// context that ignores the result.
ExprResult Sema::IgnoredValueConversions(Expr *E) {
if (E->hasPlaceholderType()) {
ExprResult result = CheckPlaceholderExpr(E);
if (result.isInvalid()) return E;
E = result.get();
}
// C99 6.3.2.1:
// [Except in specific positions,] an lvalue that does not have
// array type is converted to the value stored in the
// designated object (and is no longer an lvalue).
if (E->isRValue()) {
// In C, function designators (i.e. expressions of function type)
// are r-values, but we still want to do function-to-pointer decay
// on them. This is both technically correct and convenient for
// some clients.
if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType())
return DefaultFunctionArrayConversion(E);
return E;
}
if (getLangOpts().CPlusPlus) {
// The C++11 standard defines the notion of a discarded-value expression;
// normally, we don't need to do anything to handle it, but if it is a
// volatile lvalue with a special form, we perform an lvalue-to-rvalue
// conversion.
if (getLangOpts().CPlusPlus11 && E->isGLValue() &&
E->getType().isVolatileQualified() &&
IsSpecialDiscardedValue(E)) {
ExprResult Res = DefaultLvalueConversion(E);
if (Res.isInvalid())
return E;
E = Res.get();
}
return E;
}
// GCC seems to also exclude expressions of incomplete enum type.
if (const EnumType *T = E->getType()->getAs<EnumType>()) {
if (!T->getDecl()->isComplete()) {
// FIXME: stupid workaround for a codegen bug!
E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get();
return E;
}
}
ExprResult Res = DefaultFunctionArrayLvalueConversion(E);
if (Res.isInvalid())
return E;
E = Res.get();
if (!E->getType()->isVoidType())
RequireCompleteType(E->getExprLoc(), E->getType(),
diag::err_incomplete_type);
return E;
}
// If we can unambiguously determine whether Var can never be used
// in a constant expression, return true.
// - if the variable and its initializer are non-dependent, then
// we can unambiguously check if the variable is a constant expression.
// - if the initializer is not value dependent - we can determine whether
// it can be used to initialize a constant expression. If Init can not
// be used to initialize a constant expression we conclude that Var can
// never be a constant expression.
// - FXIME: if the initializer is dependent, we can still do some analysis and
// identify certain cases unambiguously as non-const by using a Visitor:
// - such as those that involve odr-use of a ParmVarDecl, involve a new
// delete, lambda-expr, dynamic-cast, reinterpret-cast etc...
static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var,
ASTContext &Context) {
if (isa<ParmVarDecl>(Var)) return true;
const VarDecl *DefVD = nullptr;
// If there is no initializer - this can not be a constant expression.
if (!Var->getAnyInitializer(DefVD)) return true;
assert(DefVD);
if (DefVD->isWeak()) return false;
EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt();
Expr *Init = cast<Expr>(Eval->Value);
if (Var->getType()->isDependentType() || Init->isValueDependent()) {
// FIXME: Teach the constant evaluator to deal with the non-dependent parts
// of value-dependent expressions, and use it here to determine whether the
// initializer is a potential constant expression.
return false;
}
return !IsVariableAConstantExpression(Var, Context);
}
/// \brief Check if the current lambda has any potential captures
/// that must be captured by any of its enclosing lambdas that are ready to
/// capture. If there is a lambda that can capture a nested
/// potential-capture, go ahead and do so. Also, check to see if any
/// variables are uncaptureable or do not involve an odr-use so do not
/// need to be captured.
static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(
Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) {
assert(!S.isUnevaluatedContext());
assert(S.CurContext->isDependentContext());
assert(CurrentLSI->CallOperator == S.CurContext &&
"The current call operator must be synchronized with Sema's CurContext");
const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent();
ArrayRef<const FunctionScopeInfo *> FunctionScopesArrayRef(
S.FunctionScopes.data(), S.FunctionScopes.size());
// All the potentially captureable variables in the current nested
// lambda (within a generic outer lambda), must be captured by an
// outer lambda that is enclosed within a non-dependent context.
const unsigned NumPotentialCaptures =
CurrentLSI->getNumPotentialVariableCaptures();
for (unsigned I = 0; I != NumPotentialCaptures; ++I) {
Expr *VarExpr = nullptr;
VarDecl *Var = nullptr;
CurrentLSI->getPotentialVariableCapture(I, Var, VarExpr);
// If the variable is clearly identified as non-odr-used and the full
// expression is not instantiation dependent, only then do we not
// need to check enclosing lambda's for speculative captures.
// For e.g.:
// Even though 'x' is not odr-used, it should be captured.
// int test() {
// const int x = 10;
// auto L = [=](auto a) {
// (void) +x + a;
// };
// }
if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) &&
!IsFullExprInstantiationDependent)
continue;
// If we have a capture-capable lambda for the variable, go ahead and
// capture the variable in that lambda (and all its enclosing lambdas).
if (const Optional<unsigned> Index =
getStackIndexOfNearestEnclosingCaptureCapableLambda(
FunctionScopesArrayRef, Var, S)) {
const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
MarkVarDeclODRUsed(Var, VarExpr->getExprLoc(), S,
&FunctionScopeIndexOfCapturableLambda);
}
const bool IsVarNeverAConstantExpression =
VariableCanNeverBeAConstantExpression(Var, S.Context);
if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) {
// This full expression is not instantiation dependent or the variable
// can not be used in a constant expression - which means
// this variable must be odr-used here, so diagnose a
// capture violation early, if the variable is un-captureable.
// This is purely for diagnosing errors early. Otherwise, this
// error would get diagnosed when the lambda becomes capture ready.
QualType CaptureType, DeclRefType;
SourceLocation ExprLoc = VarExpr->getExprLoc();
if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
/*EllipsisLoc*/ SourceLocation(),
/*BuildAndDiagnose*/false, CaptureType,
DeclRefType, nullptr)) {
// We will never be able to capture this variable, and we need
// to be able to in any and all instantiations, so diagnose it.
S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit,
/*EllipsisLoc*/ SourceLocation(),
/*BuildAndDiagnose*/true, CaptureType,
DeclRefType, nullptr);
}
}
}
// Check if 'this' needs to be captured.
if (CurrentLSI->hasPotentialThisCapture()) {
// If we have a capture-capable lambda for 'this', go ahead and capture
// 'this' in that lambda (and all its enclosing lambdas).
if (const Optional<unsigned> Index =
getStackIndexOfNearestEnclosingCaptureCapableLambda(
FunctionScopesArrayRef, /*0 is 'this'*/ nullptr, S)) {
const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue();
S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation,
/*Explicit*/ false, /*BuildAndDiagnose*/ true,
&FunctionScopeIndexOfCapturableLambda);
}
}
// Reset all the potential captures at the end of each full-expression.
CurrentLSI->clearPotentialCaptures();
}
static ExprResult attemptRecovery(Sema &SemaRef,
const TypoCorrectionConsumer &Consumer,
TypoCorrection TC) {
LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(),
Consumer.getLookupResult().getLookupKind());
const CXXScopeSpec *SS = Consumer.getSS();
CXXScopeSpec NewSS;
// Use an approprate CXXScopeSpec for building the expr.
if (auto *NNS = TC.getCorrectionSpecifier())
NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange());
else if (SS && !TC.WillReplaceSpecifier())
NewSS = *SS;
if (auto *ND = TC.getFoundDecl()) {
R.setLookupName(ND->getDeclName());
R.addDecl(ND);
if (ND->isCXXClassMember()) {
// Figure out the correct naming class to add to the LookupResult.
CXXRecordDecl *Record = nullptr;
if (auto *NNS = TC.getCorrectionSpecifier())
Record = NNS->getAsType()->getAsCXXRecordDecl();
if (!Record)
Record =
dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext());
if (Record)
R.setNamingClass(Record);
// Detect and handle the case where the decl might be an implicit
// member.
bool MightBeImplicitMember;
if (!Consumer.isAddressOfOperand())
MightBeImplicitMember = true;
else if (!NewSS.isEmpty())
MightBeImplicitMember = false;
else if (R.isOverloadedResult())
MightBeImplicitMember = false;
else if (R.isUnresolvableResult())
MightBeImplicitMember = true;
else
MightBeImplicitMember = isa<FieldDecl>(ND) ||
isa<IndirectFieldDecl>(ND) ||
isa<MSPropertyDecl>(ND);
if (MightBeImplicitMember)
return SemaRef.BuildPossibleImplicitMemberExpr(
NewSS, /*TemplateKWLoc*/ SourceLocation(), R,
/*TemplateArgs*/ nullptr, /*S*/ nullptr);
} else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) {
return SemaRef.LookupInObjCMethod(R, Consumer.getScope(),
Ivar->getIdentifier());
}
}
return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false,
/*AcceptInvalidDecl*/ true);
}
namespace {
class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> {
llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs;
public:
explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs)
: TypoExprs(TypoExprs) {}
bool VisitTypoExpr(TypoExpr *TE) {
TypoExprs.insert(TE);
return true;
}
};
class TransformTypos : public TreeTransform<TransformTypos> {
typedef TreeTransform<TransformTypos> BaseTransform;
VarDecl *InitDecl; // A decl to avoid as a correction because it is in the
// process of being initialized.
llvm::function_ref<ExprResult(Expr *)> ExprFilter;
llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs;
llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache;
llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution;
/// \brief Emit diagnostics for all of the TypoExprs encountered.
/// If the TypoExprs were successfully corrected, then the diagnostics should
/// suggest the corrections. Otherwise the diagnostics will not suggest
/// anything (having been passed an empty TypoCorrection).
void EmitAllDiagnostics() {
for (auto E : TypoExprs) {
TypoExpr *TE = cast<TypoExpr>(E);
auto &State = SemaRef.getTypoExprState(TE);
if (State.DiagHandler) {
TypoCorrection TC = State.Consumer->getCurrentCorrection();
ExprResult Replacement = TransformCache[TE];
// Extract the NamedDecl from the transformed TypoExpr and add it to the
// TypoCorrection, replacing the existing decls. This ensures the right
// NamedDecl is used in diagnostics e.g. in the case where overload
// resolution was used to select one from several possible decls that
// had been stored in the TypoCorrection.
if (auto *ND = getDeclFromExpr(
Replacement.isInvalid() ? nullptr : Replacement.get()))
TC.setCorrectionDecl(ND);
State.DiagHandler(TC);
}
SemaRef.clearDelayedTypo(TE);
}
}
/// \brief If corrections for the first TypoExpr have been exhausted for a
/// given combination of the other TypoExprs, retry those corrections against
/// the next combination of substitutions for the other TypoExprs by advancing
/// to the next potential correction of the second TypoExpr. For the second
/// and subsequent TypoExprs, if its stream of corrections has been exhausted,
/// the stream is reset and the next TypoExpr's stream is advanced by one (a
/// TypoExpr's correction stream is advanced by removing the TypoExpr from the
/// TransformCache). Returns true if there is still any untried combinations
/// of corrections.
bool CheckAndAdvanceTypoExprCorrectionStreams() {
for (auto TE : TypoExprs) {
auto &State = SemaRef.getTypoExprState(TE);
TransformCache.erase(TE);
if (!State.Consumer->finished())
return true;
State.Consumer->resetCorrectionStream();
}
return false;
}
NamedDecl *getDeclFromExpr(Expr *E) {
if (auto *OE = dyn_cast_or_null<OverloadExpr>(E))
E = OverloadResolution[OE];
if (!E)
return nullptr;
if (auto *DRE = dyn_cast<DeclRefExpr>(E))
return DRE->getFoundDecl();
if (auto *ME = dyn_cast<MemberExpr>(E))
return ME->getFoundDecl();
// FIXME: Add any other expr types that could be be seen by the delayed typo
// correction TreeTransform for which the corresponding TypoCorrection could
// contain multiple decls.
return nullptr;
}
ExprResult TryTransform(Expr *E) {
Sema::SFINAETrap Trap(SemaRef);
ExprResult Res = TransformExpr(E);
if (Trap.hasErrorOccurred() || Res.isInvalid())
return ExprError();
return ExprFilter(Res.get());
}
public:
TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref<ExprResult(Expr *)> Filter)
: BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {}
ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc,
MultiExprArg Args,
SourceLocation RParenLoc,
Expr *ExecConfig = nullptr) {
auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args,
RParenLoc, ExecConfig);
if (auto *OE = dyn_cast<OverloadExpr>(Callee)) {
if (Result.isUsable()) {
Expr *ResultCall = Result.get();
if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall))
ResultCall = BE->getSubExpr();
if (auto *CE = dyn_cast<CallExpr>(ResultCall))
OverloadResolution[OE] = CE->getCallee();
}
}
return Result;
}
ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); }
ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); }
ExprResult TransformObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
return Owned(E);
}
ExprResult TransformObjCIvarRefExpr(ObjCIvarRefExpr *E) {
return Owned(E);
}
ExprResult Transform(Expr *E) {
ExprResult Res;
while (true) {
Res = TryTransform(E);
// Exit if either the transform was valid or if there were no TypoExprs
// to transform that still have any untried correction candidates..
if (!Res.isInvalid() ||
!CheckAndAdvanceTypoExprCorrectionStreams())
break;
}
// Ensure none of the TypoExprs have multiple typo correction candidates
// with the same edit length that pass all the checks and filters.
// TODO: Properly handle various permutations of possible corrections when
// there is more than one potentially ambiguous typo correction.
// Also, disable typo correction while attempting the transform when
// handling potentially ambiguous typo corrections as any new TypoExprs will
// have been introduced by the application of one of the correction
// candidates and add little to no value if corrected.
SemaRef.DisableTypoCorrection = true;
while (!AmbiguousTypoExprs.empty()) {
auto TE = AmbiguousTypoExprs.back();
auto Cached = TransformCache[TE];
auto &State = SemaRef.getTypoExprState(TE);
State.Consumer->saveCurrentPosition();
TransformCache.erase(TE);
if (!TryTransform(E).isInvalid()) {
State.Consumer->resetCorrectionStream();
TransformCache.erase(TE);
Res = ExprError();
break;
}
AmbiguousTypoExprs.remove(TE);
State.Consumer->restoreSavedPosition();
TransformCache[TE] = Cached;
}
SemaRef.DisableTypoCorrection = false;
// Ensure that all of the TypoExprs within the current Expr have been found.
if (!Res.isUsable())
FindTypoExprs(TypoExprs).TraverseStmt(E);
EmitAllDiagnostics();
return Res;
}
ExprResult TransformTypoExpr(TypoExpr *E) {
// If the TypoExpr hasn't been seen before, record it. Otherwise, return the
// cached transformation result if there is one and the TypoExpr isn't the
// first one that was encountered.
auto &CacheEntry = TransformCache[E];
if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) {
return CacheEntry;
}
auto &State = SemaRef.getTypoExprState(E);
assert(State.Consumer && "Cannot transform a cleared TypoExpr");
// For the first TypoExpr and an uncached TypoExpr, find the next likely
// typo correction and return it.
while (TypoCorrection TC = State.Consumer->getNextCorrection()) {
if (InitDecl && TC.getFoundDecl() == InitDecl)
continue;
ExprResult NE = State.RecoveryHandler ?
State.RecoveryHandler(SemaRef, E, TC) :
attemptRecovery(SemaRef, *State.Consumer, TC);
if (!NE.isInvalid()) {
// Check whether there may be a second viable correction with the same
// edit distance; if so, remember this TypoExpr may have an ambiguous
// correction so it can be more thoroughly vetted later.
TypoCorrection Next;
if ((Next = State.Consumer->peekNextCorrection()) &&
Next.getEditDistance(false) == TC.getEditDistance(false)) {
AmbiguousTypoExprs.insert(E);
} else {
AmbiguousTypoExprs.remove(E);
}
assert(!NE.isUnset() &&
"Typo was transformed into a valid-but-null ExprResult");
return CacheEntry = NE;
}
}
return CacheEntry = ExprError();
}
};
}
ExprResult
Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl,
llvm::function_ref<ExprResult(Expr *)> Filter) {
// If the current evaluation context indicates there are uncorrected typos
// and the current expression isn't guaranteed to not have typos, try to
// resolve any TypoExpr nodes that might be in the expression.
if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos &&
(E->isTypeDependent() || E->isValueDependent() ||
E->isInstantiationDependent())) {
auto TyposInContext = ExprEvalContexts.back().NumTypos;
assert(TyposInContext < ~0U && "Recursive call of CorrectDelayedTyposInExpr");
ExprEvalContexts.back().NumTypos = ~0U;
auto TyposResolved = DelayedTypos.size();
auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E);
ExprEvalContexts.back().NumTypos = TyposInContext;
TyposResolved -= DelayedTypos.size();
if (Result.isInvalid() || Result.get() != E) {
ExprEvalContexts.back().NumTypos -= TyposResolved;
return Result;
}
assert(TyposResolved == 0 && "Corrected typo but got same Expr back?");
}
return E;
}
ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC,
bool DiscardedValue,
bool IsConstexpr,
bool IsLambdaInitCaptureInitializer) {
ExprResult FullExpr = FE;
if (!FullExpr.get())
return ExprError();
// If we are an init-expression in a lambdas init-capture, we should not
// diagnose an unexpanded pack now (will be diagnosed once lambda-expr
// containing full-expression is done).
// template<class ... Ts> void test(Ts ... t) {
// test([&a(t)]() { <-- (t) is an init-expr that shouldn't be diagnosed now.
// return a;
// }() ...);
// }
// FIXME: This is a hack. It would be better if we pushed the lambda scope
// when we parse the lambda introducer, and teach capturing (but not
// unexpanded pack detection) to walk over LambdaScopeInfos which don't have a
// corresponding class yet (that is, have LambdaScopeInfo either represent a
// lambda where we've entered the introducer but not the body, or represent a
// lambda where we've entered the body, depending on where the
// parser/instantiation has got to).
if (!IsLambdaInitCaptureInitializer &&
DiagnoseUnexpandedParameterPack(FullExpr.get()))
return ExprError();
// Top-level expressions default to 'id' when we're in a debugger.
if (DiscardedValue && getLangOpts().DebuggerCastResultToId &&
FullExpr.get()->getType() == Context.UnknownAnyTy) {
FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType());
if (FullExpr.isInvalid())
return ExprError();
}
if (DiscardedValue) {
FullExpr = CheckPlaceholderExpr(FullExpr.get());
if (FullExpr.isInvalid())
return ExprError();
FullExpr = IgnoredValueConversions(FullExpr.get());
if (FullExpr.isInvalid())
return ExprError();
}
FullExpr = CorrectDelayedTyposInExpr(FullExpr.get());
if (FullExpr.isInvalid())
return ExprError();
CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr);
// At the end of this full expression (which could be a deeply nested
// lambda), if there is a potential capture within the nested lambda,
// have the outer capture-able lambda try and capture it.
// Consider the following code:
// void f(int, int);
// void f(const int&, double);
// void foo() {
// const int x = 10, y = 20;
// auto L = [=](auto a) {
// auto M = [=](auto b) {
// f(x, b); <-- requires x to be captured by L and M
// f(y, a); <-- requires y to be captured by L, but not all Ms
// };
// };
// }
// FIXME: Also consider what happens for something like this that involves
// the gnu-extension statement-expressions or even lambda-init-captures:
// void f() {
// const int n = 0;
// auto L = [&](auto a) {
// +n + ({ 0; a; });
// };
// }
//
// Here, we see +n, and then the full-expression 0; ends, so we don't
// capture n (and instead remove it from our list of potential captures),
// and then the full-expression +n + ({ 0; }); ends, but it's too late
// for us to see that we need to capture n after all.
LambdaScopeInfo *const CurrentLSI = getCurLambda();
// FIXME: PR 17877 showed that getCurLambda() can return a valid pointer
// even if CurContext is not a lambda call operator. Refer to that Bug Report
// for an example of the code that might cause this asynchrony.
// By ensuring we are in the context of a lambda's call operator
// we can fix the bug (we only need to check whether we need to capture
// if we are within a lambda's body); but per the comments in that
// PR, a proper fix would entail :
// "Alternative suggestion:
// - Add to Sema an integer holding the smallest (outermost) scope
// index that we are *lexically* within, and save/restore/set to
// FunctionScopes.size() in InstantiatingTemplate's
// constructor/destructor.
// - Teach the handful of places that iterate over FunctionScopes to
// stop at the outermost enclosing lexical scope."
const bool IsInLambdaDeclContext = isLambdaCallOperator(CurContext);
if (IsInLambdaDeclContext && CurrentLSI &&
CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid())
CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI,
*this);
return MaybeCreateExprWithCleanups(FullExpr);
}
StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) {
if (!FullStmt) return StmtError();
return MaybeCreateStmtWithCleanups(FullStmt);
}
Sema::IfExistsResult
Sema::CheckMicrosoftIfExistsSymbol(Scope *S,
CXXScopeSpec &SS,
const DeclarationNameInfo &TargetNameInfo) {
DeclarationName TargetName = TargetNameInfo.getName();
if (!TargetName)
return IER_DoesNotExist;
// If the name itself is dependent, then the result is dependent.
if (TargetName.isDependentName())
return IER_Dependent;
// Do the redeclaration lookup in the current scope.
LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName,
Sema::NotForRedeclaration);
LookupParsedName(R, S, &SS);
R.suppressDiagnostics();
switch (R.getResultKind()) {
case LookupResult::Found:
case LookupResult::FoundOverloaded:
case LookupResult::FoundUnresolvedValue:
case LookupResult::Ambiguous:
return IER_Exists;
case LookupResult::NotFound:
return IER_DoesNotExist;
case LookupResult::NotFoundInCurrentInstantiation:
return IER_Dependent;
}
llvm_unreachable("Invalid LookupResult Kind!");
}
Sema::IfExistsResult
Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
bool IsIfExists, CXXScopeSpec &SS,
UnqualifiedId &Name) {
DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
// Check for unexpanded parameter packs.
SmallVector<UnexpandedParameterPack, 4> Unexpanded;
collectUnexpandedParameterPacks(SS, Unexpanded);
collectUnexpandedParameterPacks(TargetNameInfo, Unexpanded);
if (!Unexpanded.empty()) {
DiagnoseUnexpandedParameterPacks(KeywordLoc,
IsIfExists? UPPC_IfExists
: UPPC_IfNotExists,
Unexpanded);
return IER_Error;
}
return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo);
}
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