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SemaPseudoObject.cpp
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//===--- SemaPseudoObject.cpp - Semantic Analysis for Pseudo-Objects ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements semantic analysis for expressions involving
// pseudo-object references. Pseudo-objects are conceptual objects
// whose storage is entirely abstract and all accesses to which are
// translated through some sort of abstraction barrier.
//
// For example, Objective-C objects can have "properties", either
// declared or undeclared. A property may be accessed by writing
// expr.prop
// where 'expr' is an r-value of Objective-C pointer type and 'prop'
// is the name of the property. If this expression is used in a context
// needing an r-value, it is treated as if it were a message-send
// of the associated 'getter' selector, typically:
// [expr prop]
// If it is used as the LHS of a simple assignment, it is treated
// as a message-send of the associated 'setter' selector, typically:
// [expr setProp: RHS]
// If it is used as the LHS of a compound assignment, or the operand
// of a unary increment or decrement, both are required; for example,
// 'expr.prop *= 100' would be translated to:
// [expr setProp: [expr prop] * 100]
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/ScopeInfo.h"
#include "llvm/ADT/SmallString.h"
using namespace clang;
using namespace sema;
namespace {
// Basically just a very focused copy of TreeTransform.
struct Rebuilder {
Sema &S;
unsigned MSPropertySubscriptCount;
typedef llvm::function_ref<Expr *(Expr *, unsigned)> SpecificRebuilderRefTy;
const SpecificRebuilderRefTy &SpecificCallback;
Rebuilder(Sema &S, const SpecificRebuilderRefTy &SpecificCallback)
: S(S), MSPropertySubscriptCount(0),
SpecificCallback(SpecificCallback) {}
Expr *rebuildObjCPropertyRefExpr(ObjCPropertyRefExpr *refExpr) {
// Fortunately, the constraint that we're rebuilding something
// with a base limits the number of cases here.
if (refExpr->isClassReceiver() || refExpr->isSuperReceiver())
return refExpr;
if (refExpr->isExplicitProperty()) {
return new (S.Context) ObjCPropertyRefExpr(
refExpr->getExplicitProperty(), refExpr->getType(),
refExpr->getValueKind(), refExpr->getObjectKind(),
refExpr->getLocation(), SpecificCallback(refExpr->getBase(), 0));
}
return new (S.Context) ObjCPropertyRefExpr(
refExpr->getImplicitPropertyGetter(),
refExpr->getImplicitPropertySetter(), refExpr->getType(),
refExpr->getValueKind(), refExpr->getObjectKind(),
refExpr->getLocation(), SpecificCallback(refExpr->getBase(), 0));
}
Expr *rebuildObjCSubscriptRefExpr(ObjCSubscriptRefExpr *refExpr) {
assert(refExpr->getBaseExpr());
assert(refExpr->getKeyExpr());
return new (S.Context) ObjCSubscriptRefExpr(
SpecificCallback(refExpr->getBaseExpr(), 0),
SpecificCallback(refExpr->getKeyExpr(), 1), refExpr->getType(),
refExpr->getValueKind(), refExpr->getObjectKind(),
refExpr->getAtIndexMethodDecl(), refExpr->setAtIndexMethodDecl(),
refExpr->getRBracket());
}
Expr *rebuildMSPropertyRefExpr(MSPropertyRefExpr *refExpr) {
assert(refExpr->getBaseExpr());
return new (S.Context) MSPropertyRefExpr(
SpecificCallback(refExpr->getBaseExpr(), 0),
refExpr->getPropertyDecl(), refExpr->isArrow(), refExpr->getType(),
refExpr->getValueKind(), refExpr->getQualifierLoc(),
refExpr->getMemberLoc());
}
Expr *rebuildMSPropertySubscriptExpr(MSPropertySubscriptExpr *refExpr) {
assert(refExpr->getBase());
assert(refExpr->getIdx());
auto *NewBase = rebuild(refExpr->getBase());
++MSPropertySubscriptCount;
return new (S.Context) MSPropertySubscriptExpr(
NewBase,
SpecificCallback(refExpr->getIdx(), MSPropertySubscriptCount),
refExpr->getType(), refExpr->getValueKind(), refExpr->getObjectKind(),
refExpr->getRBracketLoc());
}
Expr *rebuild(Expr *e) {
// Fast path: nothing to look through.
if (auto *PRE = dyn_cast<ObjCPropertyRefExpr>(e))
return rebuildObjCPropertyRefExpr(PRE);
if (auto *SRE = dyn_cast<ObjCSubscriptRefExpr>(e))
return rebuildObjCSubscriptRefExpr(SRE);
if (auto *MSPRE = dyn_cast<MSPropertyRefExpr>(e))
return rebuildMSPropertyRefExpr(MSPRE);
if (auto *MSPSE = dyn_cast<MSPropertySubscriptExpr>(e))
return rebuildMSPropertySubscriptExpr(MSPSE);
// Otherwise, we should look through and rebuild anything that
// IgnoreParens would.
if (ParenExpr *parens = dyn_cast<ParenExpr>(e)) {
e = rebuild(parens->getSubExpr());
return new (S.Context) ParenExpr(parens->getLParen(),
parens->getRParen(),
e);
}
if (UnaryOperator *uop = dyn_cast<UnaryOperator>(e)) {
assert(uop->getOpcode() == UO_Extension);
e = rebuild(uop->getSubExpr());
return new (S.Context) UnaryOperator(e, uop->getOpcode(),
uop->getType(),
uop->getValueKind(),
uop->getObjectKind(),
uop->getOperatorLoc(),
uop->canOverflow());
}
if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
assert(!gse->isResultDependent());
unsigned resultIndex = gse->getResultIndex();
unsigned numAssocs = gse->getNumAssocs();
SmallVector<Expr*, 8> assocs(numAssocs);
SmallVector<TypeSourceInfo*, 8> assocTypes(numAssocs);
for (unsigned i = 0; i != numAssocs; ++i) {
Expr *assoc = gse->getAssocExpr(i);
if (i == resultIndex) assoc = rebuild(assoc);
assocs[i] = assoc;
assocTypes[i] = gse->getAssocTypeSourceInfo(i);
}
return new (S.Context) GenericSelectionExpr(S.Context,
gse->getGenericLoc(),
gse->getControllingExpr(),
assocTypes,
assocs,
gse->getDefaultLoc(),
gse->getRParenLoc(),
gse->containsUnexpandedParameterPack(),
resultIndex);
}
if (ChooseExpr *ce = dyn_cast<ChooseExpr>(e)) {
assert(!ce->isConditionDependent());
Expr *LHS = ce->getLHS(), *RHS = ce->getRHS();
Expr *&rebuiltExpr = ce->isConditionTrue() ? LHS : RHS;
rebuiltExpr = rebuild(rebuiltExpr);
return new (S.Context) ChooseExpr(ce->getBuiltinLoc(),
ce->getCond(),
LHS, RHS,
rebuiltExpr->getType(),
rebuiltExpr->getValueKind(),
rebuiltExpr->getObjectKind(),
ce->getRParenLoc(),
ce->isConditionTrue(),
rebuiltExpr->isTypeDependent(),
rebuiltExpr->isValueDependent());
}
llvm_unreachable("bad expression to rebuild!");
}
};
class PseudoOpBuilder {
public:
Sema &S;
unsigned ResultIndex;
SourceLocation GenericLoc;
bool IsUnique;
SmallVector<Expr *, 4> Semantics;
PseudoOpBuilder(Sema &S, SourceLocation genericLoc, bool IsUnique)
: S(S), ResultIndex(PseudoObjectExpr::NoResult),
GenericLoc(genericLoc), IsUnique(IsUnique) {}
virtual ~PseudoOpBuilder() {}
/// Add a normal semantic expression.
void addSemanticExpr(Expr *semantic) {
Semantics.push_back(semantic);
}
/// Add the 'result' semantic expression.
void addResultSemanticExpr(Expr *resultExpr) {
assert(ResultIndex == PseudoObjectExpr::NoResult);
ResultIndex = Semantics.size();
Semantics.push_back(resultExpr);
// An OVE is not unique if it is used as the result expression.
if (auto *OVE = dyn_cast<OpaqueValueExpr>(Semantics.back()))
OVE->setIsUnique(false);
}
ExprResult buildRValueOperation(Expr *op);
ExprResult buildAssignmentOperation(Scope *Sc,
SourceLocation opLoc,
BinaryOperatorKind opcode,
Expr *LHS, Expr *RHS);
ExprResult buildIncDecOperation(Scope *Sc, SourceLocation opLoc,
UnaryOperatorKind opcode,
Expr *op);
virtual ExprResult complete(Expr *syntacticForm);
OpaqueValueExpr *capture(Expr *op);
OpaqueValueExpr *captureValueAsResult(Expr *op);
void setResultToLastSemantic() {
assert(ResultIndex == PseudoObjectExpr::NoResult);
ResultIndex = Semantics.size() - 1;
// An OVE is not unique if it is used as the result expression.
if (auto *OVE = dyn_cast<OpaqueValueExpr>(Semantics.back()))
OVE->setIsUnique(false);
}
/// Return true if assignments have a non-void result.
static bool CanCaptureValue(Expr *exp) {
if (exp->isGLValue())
return true;
QualType ty = exp->getType();
assert(!ty->isIncompleteType());
assert(!ty->isDependentType());
if (const CXXRecordDecl *ClassDecl = ty->getAsCXXRecordDecl())
return ClassDecl->isTriviallyCopyable();
return true;
}
virtual Expr *rebuildAndCaptureObject(Expr *) = 0;
virtual ExprResult buildGet() = 0;
virtual ExprResult buildSet(Expr *, SourceLocation,
bool captureSetValueAsResult) = 0;
/// \brief Should the result of an assignment be the formal result of the
/// setter call or the value that was passed to the setter?
///
/// Different pseudo-object language features use different language rules
/// for this.
/// The default is to use the set value. Currently, this affects the
/// behavior of simple assignments, compound assignments, and prefix
/// increment and decrement.
/// Postfix increment and decrement always use the getter result as the
/// expression result.
///
/// If this method returns true, and the set value isn't capturable for
/// some reason, the result of the expression will be void.
virtual bool captureSetValueAsResult() const { return true; }
};
/// A PseudoOpBuilder for Objective-C \@properties.
class ObjCPropertyOpBuilder : public PseudoOpBuilder {
ObjCPropertyRefExpr *RefExpr;
ObjCPropertyRefExpr *SyntacticRefExpr;
OpaqueValueExpr *InstanceReceiver;
ObjCMethodDecl *Getter;
ObjCMethodDecl *Setter;
Selector SetterSelector;
Selector GetterSelector;
public:
ObjCPropertyOpBuilder(Sema &S, ObjCPropertyRefExpr *refExpr, bool IsUnique)
: PseudoOpBuilder(S, refExpr->getLocation(), IsUnique),
RefExpr(refExpr), SyntacticRefExpr(nullptr),
InstanceReceiver(nullptr), Getter(nullptr), Setter(nullptr) {
}
ExprResult buildRValueOperation(Expr *op);
ExprResult buildAssignmentOperation(Scope *Sc,
SourceLocation opLoc,
BinaryOperatorKind opcode,
Expr *LHS, Expr *RHS);
ExprResult buildIncDecOperation(Scope *Sc, SourceLocation opLoc,
UnaryOperatorKind opcode,
Expr *op);
bool tryBuildGetOfReference(Expr *op, ExprResult &result);
bool findSetter(bool warn=true);
bool findGetter();
void DiagnoseUnsupportedPropertyUse();
Expr *rebuildAndCaptureObject(Expr *syntacticBase) override;
ExprResult buildGet() override;
ExprResult buildSet(Expr *op, SourceLocation, bool) override;
ExprResult complete(Expr *SyntacticForm) override;
bool isWeakProperty() const;
};
/// A PseudoOpBuilder for Objective-C array/dictionary indexing.
class ObjCSubscriptOpBuilder : public PseudoOpBuilder {
ObjCSubscriptRefExpr *RefExpr;
OpaqueValueExpr *InstanceBase;
OpaqueValueExpr *InstanceKey;
ObjCMethodDecl *AtIndexGetter;
Selector AtIndexGetterSelector;
ObjCMethodDecl *AtIndexSetter;
Selector AtIndexSetterSelector;
public:
ObjCSubscriptOpBuilder(Sema &S, ObjCSubscriptRefExpr *refExpr, bool IsUnique)
: PseudoOpBuilder(S, refExpr->getSourceRange().getBegin(), IsUnique),
RefExpr(refExpr), InstanceBase(nullptr), InstanceKey(nullptr),
AtIndexGetter(nullptr), AtIndexSetter(nullptr) {}
ExprResult buildRValueOperation(Expr *op);
ExprResult buildAssignmentOperation(Scope *Sc,
SourceLocation opLoc,
BinaryOperatorKind opcode,
Expr *LHS, Expr *RHS);
Expr *rebuildAndCaptureObject(Expr *syntacticBase) override;
bool findAtIndexGetter();
bool findAtIndexSetter();
ExprResult buildGet() override;
ExprResult buildSet(Expr *op, SourceLocation, bool) override;
};
class MSPropertyOpBuilder : public PseudoOpBuilder {
MSPropertyRefExpr *RefExpr;
OpaqueValueExpr *InstanceBase;
SmallVector<Expr *, 4> CallArgs;
MSPropertyRefExpr *getBaseMSProperty(MSPropertySubscriptExpr *E);
public:
MSPropertyOpBuilder(Sema &S, MSPropertyRefExpr *refExpr, bool IsUnique)
: PseudoOpBuilder(S, refExpr->getSourceRange().getBegin(), IsUnique),
RefExpr(refExpr), InstanceBase(nullptr) {}
MSPropertyOpBuilder(Sema &S, MSPropertySubscriptExpr *refExpr, bool IsUnique)
: PseudoOpBuilder(S, refExpr->getSourceRange().getBegin(), IsUnique),
InstanceBase(nullptr) {
RefExpr = getBaseMSProperty(refExpr);
}
Expr *rebuildAndCaptureObject(Expr *) override;
ExprResult buildGet() override;
ExprResult buildSet(Expr *op, SourceLocation, bool) override;
bool captureSetValueAsResult() const override { return false; }
};
}
/// Capture the given expression in an OpaqueValueExpr.
OpaqueValueExpr *PseudoOpBuilder::capture(Expr *e) {
// Make a new OVE whose source is the given expression.
OpaqueValueExpr *captured =
new (S.Context) OpaqueValueExpr(GenericLoc, e->getType(),
e->getValueKind(), e->getObjectKind(),
e);
if (IsUnique)
captured->setIsUnique(true);
// Make sure we bind that in the semantics.
addSemanticExpr(captured);
return captured;
}
/// Capture the given expression as the result of this pseudo-object
/// operation. This routine is safe against expressions which may
/// already be captured.
///
/// \returns the captured expression, which will be the
/// same as the input if the input was already captured
OpaqueValueExpr *PseudoOpBuilder::captureValueAsResult(Expr *e) {
assert(ResultIndex == PseudoObjectExpr::NoResult);
// If the expression hasn't already been captured, just capture it
// and set the new semantic
if (!isa<OpaqueValueExpr>(e)) {
OpaqueValueExpr *cap = capture(e);
setResultToLastSemantic();
return cap;
}
// Otherwise, it must already be one of our semantic expressions;
// set ResultIndex to its index.
unsigned index = 0;
for (;; ++index) {
assert(index < Semantics.size() &&
"captured expression not found in semantics!");
if (e == Semantics[index]) break;
}
ResultIndex = index;
// An OVE is not unique if it is used as the result expression.
cast<OpaqueValueExpr>(e)->setIsUnique(false);
return cast<OpaqueValueExpr>(e);
}
/// The routine which creates the final PseudoObjectExpr.
ExprResult PseudoOpBuilder::complete(Expr *syntactic) {
return PseudoObjectExpr::Create(S.Context, syntactic,
Semantics, ResultIndex);
}
/// The main skeleton for building an r-value operation.
ExprResult PseudoOpBuilder::buildRValueOperation(Expr *op) {
Expr *syntacticBase = rebuildAndCaptureObject(op);
ExprResult getExpr = buildGet();
if (getExpr.isInvalid()) return ExprError();
addResultSemanticExpr(getExpr.get());
return complete(syntacticBase);
}
/// The basic skeleton for building a simple or compound
/// assignment operation.
ExprResult
PseudoOpBuilder::buildAssignmentOperation(Scope *Sc, SourceLocation opcLoc,
BinaryOperatorKind opcode,
Expr *LHS, Expr *RHS) {
assert(BinaryOperator::isAssignmentOp(opcode));
Expr *syntacticLHS = rebuildAndCaptureObject(LHS);
OpaqueValueExpr *capturedRHS = capture(RHS);
// In some very specific cases, semantic analysis of the RHS as an
// expression may require it to be rewritten. In these cases, we
// cannot safely keep the OVE around. Fortunately, we don't really
// need to: we don't use this particular OVE in multiple places, and
// no clients rely that closely on matching up expressions in the
// semantic expression with expressions from the syntactic form.
Expr *semanticRHS = capturedRHS;
if (RHS->hasPlaceholderType() || isa<InitListExpr>(RHS)) {
semanticRHS = RHS;
Semantics.pop_back();
}
Expr *syntactic;
ExprResult result;
if (opcode == BO_Assign) {
result = semanticRHS;
syntactic = new (S.Context) BinaryOperator(syntacticLHS, capturedRHS,
opcode, capturedRHS->getType(),
capturedRHS->getValueKind(),
OK_Ordinary, opcLoc,
FPOptions());
} else {
ExprResult opLHS = buildGet();
if (opLHS.isInvalid()) return ExprError();
// Build an ordinary, non-compound operation.
BinaryOperatorKind nonCompound =
BinaryOperator::getOpForCompoundAssignment(opcode);
result = S.BuildBinOp(Sc, opcLoc, nonCompound, opLHS.get(), semanticRHS);
if (result.isInvalid()) return ExprError();
syntactic =
new (S.Context) CompoundAssignOperator(syntacticLHS, capturedRHS, opcode,
result.get()->getType(),
result.get()->getValueKind(),
OK_Ordinary,
opLHS.get()->getType(),
result.get()->getType(),
opcLoc, FPOptions());
}
// The result of the assignment, if not void, is the value set into
// the l-value.
result = buildSet(result.get(), opcLoc, captureSetValueAsResult());
if (result.isInvalid()) return ExprError();
addSemanticExpr(result.get());
if (!captureSetValueAsResult() && !result.get()->getType()->isVoidType() &&
(result.get()->isTypeDependent() || CanCaptureValue(result.get())))
setResultToLastSemantic();
return complete(syntactic);
}
/// The basic skeleton for building an increment or decrement
/// operation.
ExprResult
PseudoOpBuilder::buildIncDecOperation(Scope *Sc, SourceLocation opcLoc,
UnaryOperatorKind opcode,
Expr *op) {
assert(UnaryOperator::isIncrementDecrementOp(opcode));
Expr *syntacticOp = rebuildAndCaptureObject(op);
// Load the value.
ExprResult result = buildGet();
if (result.isInvalid()) return ExprError();
QualType resultType = result.get()->getType();
// That's the postfix result.
if (UnaryOperator::isPostfix(opcode) &&
(result.get()->isTypeDependent() || CanCaptureValue(result.get()))) {
result = capture(result.get());
setResultToLastSemantic();
}
// Add or subtract a literal 1.
llvm::APInt oneV(S.Context.getTypeSize(S.Context.IntTy), 1);
Expr *one = IntegerLiteral::Create(S.Context, oneV, S.Context.IntTy,
GenericLoc);
if (UnaryOperator::isIncrementOp(opcode)) {
result = S.BuildBinOp(Sc, opcLoc, BO_Add, result.get(), one);
} else {
result = S.BuildBinOp(Sc, opcLoc, BO_Sub, result.get(), one);
}
if (result.isInvalid()) return ExprError();
// Store that back into the result. The value stored is the result
// of a prefix operation.
result = buildSet(result.get(), opcLoc, UnaryOperator::isPrefix(opcode) &&
captureSetValueAsResult());
if (result.isInvalid()) return ExprError();
addSemanticExpr(result.get());
if (UnaryOperator::isPrefix(opcode) && !captureSetValueAsResult() &&
!result.get()->getType()->isVoidType() &&
(result.get()->isTypeDependent() || CanCaptureValue(result.get())))
setResultToLastSemantic();
UnaryOperator *syntactic = new (S.Context) UnaryOperator(
syntacticOp, opcode, resultType, VK_LValue, OK_Ordinary, opcLoc,
!resultType->isDependentType()
? S.Context.getTypeSize(resultType) >=
S.Context.getTypeSize(S.Context.IntTy)
: false);
return complete(syntactic);
}
//===----------------------------------------------------------------------===//
// Objective-C @property and implicit property references
//===----------------------------------------------------------------------===//
/// Look up a method in the receiver type of an Objective-C property
/// reference.
static ObjCMethodDecl *LookupMethodInReceiverType(Sema &S, Selector sel,
const ObjCPropertyRefExpr *PRE) {
if (PRE->isObjectReceiver()) {
const ObjCObjectPointerType *PT =
PRE->getBase()->getType()->castAs<ObjCObjectPointerType>();
// Special case for 'self' in class method implementations.
if (PT->isObjCClassType() &&
S.isSelfExpr(const_cast<Expr*>(PRE->getBase()))) {
// This cast is safe because isSelfExpr is only true within
// methods.
ObjCMethodDecl *method =
cast<ObjCMethodDecl>(S.CurContext->getNonClosureAncestor());
return S.LookupMethodInObjectType(sel,
S.Context.getObjCInterfaceType(method->getClassInterface()),
/*instance*/ false);
}
return S.LookupMethodInObjectType(sel, PT->getPointeeType(), true);
}
if (PRE->isSuperReceiver()) {
if (const ObjCObjectPointerType *PT =
PRE->getSuperReceiverType()->getAs<ObjCObjectPointerType>())
return S.LookupMethodInObjectType(sel, PT->getPointeeType(), true);
return S.LookupMethodInObjectType(sel, PRE->getSuperReceiverType(), false);
}
assert(PRE->isClassReceiver() && "Invalid expression");
QualType IT = S.Context.getObjCInterfaceType(PRE->getClassReceiver());
return S.LookupMethodInObjectType(sel, IT, false);
}
bool ObjCPropertyOpBuilder::isWeakProperty() const {
QualType T;
if (RefExpr->isExplicitProperty()) {
const ObjCPropertyDecl *Prop = RefExpr->getExplicitProperty();
if (Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_weak)
return true;
T = Prop->getType();
} else if (Getter) {
T = Getter->getReturnType();
} else {
return false;
}
return T.getObjCLifetime() == Qualifiers::OCL_Weak;
}
bool ObjCPropertyOpBuilder::findGetter() {
if (Getter) return true;
// For implicit properties, just trust the lookup we already did.
if (RefExpr->isImplicitProperty()) {
if ((Getter = RefExpr->getImplicitPropertyGetter())) {
GetterSelector = Getter->getSelector();
return true;
}
else {
// Must build the getter selector the hard way.
ObjCMethodDecl *setter = RefExpr->getImplicitPropertySetter();
assert(setter && "both setter and getter are null - cannot happen");
IdentifierInfo *setterName =
setter->getSelector().getIdentifierInfoForSlot(0);
IdentifierInfo *getterName =
&S.Context.Idents.get(setterName->getName().substr(3));
GetterSelector =
S.PP.getSelectorTable().getNullarySelector(getterName);
return false;
}
}
ObjCPropertyDecl *prop = RefExpr->getExplicitProperty();
Getter = LookupMethodInReceiverType(S, prop->getGetterName(), RefExpr);
return (Getter != nullptr);
}
/// Try to find the most accurate setter declaration for the property
/// reference.
///
/// \return true if a setter was found, in which case Setter
bool ObjCPropertyOpBuilder::findSetter(bool warn) {
// For implicit properties, just trust the lookup we already did.
if (RefExpr->isImplicitProperty()) {
if (ObjCMethodDecl *setter = RefExpr->getImplicitPropertySetter()) {
Setter = setter;
SetterSelector = setter->getSelector();
return true;
} else {
IdentifierInfo *getterName =
RefExpr->getImplicitPropertyGetter()->getSelector()
.getIdentifierInfoForSlot(0);
SetterSelector =
SelectorTable::constructSetterSelector(S.PP.getIdentifierTable(),
S.PP.getSelectorTable(),
getterName);
return false;
}
}
// For explicit properties, this is more involved.
ObjCPropertyDecl *prop = RefExpr->getExplicitProperty();
SetterSelector = prop->getSetterName();
// Do a normal method lookup first.
if (ObjCMethodDecl *setter =
LookupMethodInReceiverType(S, SetterSelector, RefExpr)) {
if (setter->isPropertyAccessor() && warn)
if (const ObjCInterfaceDecl *IFace =
dyn_cast<ObjCInterfaceDecl>(setter->getDeclContext())) {
StringRef thisPropertyName = prop->getName();
// Try flipping the case of the first character.
char front = thisPropertyName.front();
front = isLowercase(front) ? toUppercase(front) : toLowercase(front);
SmallString<100> PropertyName = thisPropertyName;
PropertyName[0] = front;
IdentifierInfo *AltMember = &S.PP.getIdentifierTable().get(PropertyName);
if (ObjCPropertyDecl *prop1 = IFace->FindPropertyDeclaration(
AltMember, prop->getQueryKind()))
if (prop != prop1 && (prop1->getSetterMethodDecl() == setter)) {
S.Diag(RefExpr->getExprLoc(), diag::err_property_setter_ambiguous_use)
<< prop << prop1 << setter->getSelector();
S.Diag(prop->getLocation(), diag::note_property_declare);
S.Diag(prop1->getLocation(), diag::note_property_declare);
}
}
Setter = setter;
return true;
}
// That can fail in the somewhat crazy situation that we're
// type-checking a message send within the @interface declaration
// that declared the @property. But it's not clear that that's
// valuable to support.
return false;
}
void ObjCPropertyOpBuilder::DiagnoseUnsupportedPropertyUse() {
if (S.getCurLexicalContext()->isObjCContainer() &&
S.getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl &&
S.getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation) {
if (ObjCPropertyDecl *prop = RefExpr->getExplicitProperty()) {
S.Diag(RefExpr->getLocation(),
diag::err_property_function_in_objc_container);
S.Diag(prop->getLocation(), diag::note_property_declare);
}
}
}
/// Capture the base object of an Objective-C property expression.
Expr *ObjCPropertyOpBuilder::rebuildAndCaptureObject(Expr *syntacticBase) {
assert(InstanceReceiver == nullptr);
// If we have a base, capture it in an OVE and rebuild the syntactic
// form to use the OVE as its base.
if (RefExpr->isObjectReceiver()) {
InstanceReceiver = capture(RefExpr->getBase());
syntacticBase = Rebuilder(S, [=](Expr *, unsigned) -> Expr * {
return InstanceReceiver;
}).rebuild(syntacticBase);
}
if (ObjCPropertyRefExpr *
refE = dyn_cast<ObjCPropertyRefExpr>(syntacticBase->IgnoreParens()))
SyntacticRefExpr = refE;
return syntacticBase;
}
/// Load from an Objective-C property reference.
ExprResult ObjCPropertyOpBuilder::buildGet() {
findGetter();
if (!Getter) {
DiagnoseUnsupportedPropertyUse();
return ExprError();
}
if (SyntacticRefExpr)
SyntacticRefExpr->setIsMessagingGetter();
QualType receiverType = RefExpr->getReceiverType(S.Context);
if (!Getter->isImplicit())
S.DiagnoseUseOfDecl(Getter, GenericLoc, nullptr, true);
// Build a message-send.
ExprResult msg;
if ((Getter->isInstanceMethod() && !RefExpr->isClassReceiver()) ||
RefExpr->isObjectReceiver()) {
assert(InstanceReceiver || RefExpr->isSuperReceiver());
msg = S.BuildInstanceMessageImplicit(InstanceReceiver, receiverType,
GenericLoc, Getter->getSelector(),
Getter, None);
} else {
msg = S.BuildClassMessageImplicit(receiverType, RefExpr->isSuperReceiver(),
GenericLoc, Getter->getSelector(),
Getter, None);
}
return msg;
}
/// Store to an Objective-C property reference.
///
/// \param captureSetValueAsResult If true, capture the actual
/// value being set as the value of the property operation.
ExprResult ObjCPropertyOpBuilder::buildSet(Expr *op, SourceLocation opcLoc,
bool captureSetValueAsResult) {
if (!findSetter(false)) {
DiagnoseUnsupportedPropertyUse();
return ExprError();
}
if (SyntacticRefExpr)
SyntacticRefExpr->setIsMessagingSetter();
QualType receiverType = RefExpr->getReceiverType(S.Context);
// Use assignment constraints when possible; they give us better
// diagnostics. "When possible" basically means anything except a
// C++ class type.
if (!S.getLangOpts().CPlusPlus || !op->getType()->isRecordType()) {
QualType paramType = (*Setter->param_begin())->getType()
.substObjCMemberType(
receiverType,
Setter->getDeclContext(),
ObjCSubstitutionContext::Parameter);
if (!S.getLangOpts().CPlusPlus || !paramType->isRecordType()) {
ExprResult opResult = op;
Sema::AssignConvertType assignResult
= S.CheckSingleAssignmentConstraints(paramType, opResult);
if (opResult.isInvalid() ||
S.DiagnoseAssignmentResult(assignResult, opcLoc, paramType,
op->getType(), opResult.get(),
Sema::AA_Assigning))
return ExprError();
op = opResult.get();
assert(op && "successful assignment left argument invalid?");
}
}
// Arguments.
Expr *args[] = { op };
// Build a message-send.
ExprResult msg;
if (!Setter->isImplicit())
S.DiagnoseUseOfDecl(Setter, GenericLoc, nullptr, true);
if ((Setter->isInstanceMethod() && !RefExpr->isClassReceiver()) ||
RefExpr->isObjectReceiver()) {
msg = S.BuildInstanceMessageImplicit(InstanceReceiver, receiverType,
GenericLoc, SetterSelector, Setter,
MultiExprArg(args, 1));
} else {
msg = S.BuildClassMessageImplicit(receiverType, RefExpr->isSuperReceiver(),
GenericLoc,
SetterSelector, Setter,
MultiExprArg(args, 1));
}
if (!msg.isInvalid() && captureSetValueAsResult) {
ObjCMessageExpr *msgExpr =
cast<ObjCMessageExpr>(msg.get()->IgnoreImplicit());
Expr *arg = msgExpr->getArg(0);
if (CanCaptureValue(arg))
msgExpr->setArg(0, captureValueAsResult(arg));
}
return msg;
}
/// @property-specific behavior for doing lvalue-to-rvalue conversion.
ExprResult ObjCPropertyOpBuilder::buildRValueOperation(Expr *op) {
// Explicit properties always have getters, but implicit ones don't.
// Check that before proceeding.
if (RefExpr->isImplicitProperty() && !RefExpr->getImplicitPropertyGetter()) {
S.Diag(RefExpr->getLocation(), diag::err_getter_not_found)
<< RefExpr->getSourceRange();
return ExprError();
}
ExprResult result = PseudoOpBuilder::buildRValueOperation(op);
if (result.isInvalid()) return ExprError();
if (RefExpr->isExplicitProperty() && !Getter->hasRelatedResultType())
S.DiagnosePropertyAccessorMismatch(RefExpr->getExplicitProperty(),
Getter, RefExpr->getLocation());
// As a special case, if the method returns 'id', try to get
// a better type from the property.
if (RefExpr->isExplicitProperty() && result.get()->isRValue()) {
QualType receiverType = RefExpr->getReceiverType(S.Context);
QualType propType = RefExpr->getExplicitProperty()
->getUsageType(receiverType);
if (result.get()->getType()->isObjCIdType()) {
if (const ObjCObjectPointerType *ptr
= propType->getAs<ObjCObjectPointerType>()) {
if (!ptr->isObjCIdType())
result = S.ImpCastExprToType(result.get(), propType, CK_BitCast);
}
}
if (propType.getObjCLifetime() == Qualifiers::OCL_Weak &&
!S.Diags.isIgnored(diag::warn_arc_repeated_use_of_weak,
RefExpr->getLocation()))
S.getCurFunction()->markSafeWeakUse(RefExpr);
}
return result;
}
/// Try to build this as a call to a getter that returns a reference.
///
/// \return true if it was possible, whether or not it actually
/// succeeded
bool ObjCPropertyOpBuilder::tryBuildGetOfReference(Expr *op,
ExprResult &result) {
if (!S.getLangOpts().CPlusPlus) return false;
findGetter();
if (!Getter) {
// The property has no setter and no getter! This can happen if the type is
// invalid. Error have already been reported.
result = ExprError();
return true;
}
// Only do this if the getter returns an l-value reference type.
QualType resultType = Getter->getReturnType();
if (!resultType->isLValueReferenceType()) return false;
result = buildRValueOperation(op);
return true;
}
/// @property-specific behavior for doing assignments.
ExprResult
ObjCPropertyOpBuilder::buildAssignmentOperation(Scope *Sc,
SourceLocation opcLoc,
BinaryOperatorKind opcode,
Expr *LHS, Expr *RHS) {
assert(BinaryOperator::isAssignmentOp(opcode));
// If there's no setter, we have no choice but to try to assign to
// the result of the getter.
if (!findSetter()) {
ExprResult result;
if (tryBuildGetOfReference(LHS, result)) {
if (result.isInvalid()) return ExprError();
return S.BuildBinOp(Sc, opcLoc, opcode, result.get(), RHS);
}
// Otherwise, it's an error.
S.Diag(opcLoc, diag::err_nosetter_property_assignment)
<< unsigned(RefExpr->isImplicitProperty())
<< SetterSelector
<< LHS->getSourceRange() << RHS->getSourceRange();
return ExprError();
}
// If there is a setter, we definitely want to use it.
// Verify that we can do a compound assignment.
if (opcode != BO_Assign && !findGetter()) {
S.Diag(opcLoc, diag::err_nogetter_property_compound_assignment)
<< LHS->getSourceRange() << RHS->getSourceRange();
return ExprError();
}
ExprResult result =
PseudoOpBuilder::buildAssignmentOperation(Sc, opcLoc, opcode, LHS, RHS);
if (result.isInvalid()) return ExprError();
// Various warnings about property assignments in ARC.
if (S.getLangOpts().ObjCAutoRefCount && InstanceReceiver) {
S.checkRetainCycles(InstanceReceiver->getSourceExpr(), RHS);
S.checkUnsafeExprAssigns(opcLoc, LHS, RHS);
}
return result;
}
/// @property-specific behavior for doing increments and decrements.
ExprResult
ObjCPropertyOpBuilder::buildIncDecOperation(Scope *Sc, SourceLocation opcLoc,
UnaryOperatorKind opcode,
Expr *op) {
// If there's no setter, we have no choice but to try to assign to
// the result of the getter.
if (!findSetter()) {
ExprResult result;
if (tryBuildGetOfReference(op, result)) {
if (result.isInvalid()) return ExprError();
return S.BuildUnaryOp(Sc, opcLoc, opcode, result.get());
}
// Otherwise, it's an error.
S.Diag(opcLoc, diag::err_nosetter_property_incdec)
<< unsigned(RefExpr->isImplicitProperty())
<< unsigned(UnaryOperator::isDecrementOp(opcode))
<< SetterSelector
<< op->getSourceRange();
return ExprError();
}
// If there is a setter, we definitely want to use it.
// We also need a getter.
if (!findGetter()) {
assert(RefExpr->isImplicitProperty());
S.Diag(opcLoc, diag::err_nogetter_property_incdec)
<< unsigned(UnaryOperator::isDecrementOp(opcode))
<< GetterSelector
<< op->getSourceRange();
return ExprError();
}
return PseudoOpBuilder::buildIncDecOperation(Sc, opcLoc, opcode, op);
}
ExprResult ObjCPropertyOpBuilder::complete(Expr *SyntacticForm) {
if (isWeakProperty() && !S.isUnevaluatedContext() &&
!S.Diags.isIgnored(diag::warn_arc_repeated_use_of_weak,
SyntacticForm->getLocStart()))
S.getCurFunction()->recordUseOfWeak(SyntacticRefExpr,
SyntacticRefExpr->isMessagingGetter());
return PseudoOpBuilder::complete(SyntacticForm);
}
// ObjCSubscript build stuff.
//
/// objective-c subscripting-specific behavior for doing lvalue-to-rvalue
/// conversion.
/// FIXME. Remove this routine if it is proven that no additional
/// specifity is needed.
ExprResult ObjCSubscriptOpBuilder::buildRValueOperation(Expr *op) {
ExprResult result = PseudoOpBuilder::buildRValueOperation(op);
if (result.isInvalid()) return ExprError();
return result;
}
/// objective-c subscripting-specific behavior for doing assignments.