1 //===--- TransZeroOutPropsInDealloc.cpp - Tranformations to ARC mode ------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // removeZeroOutPropsInDealloc:
12 // Removes zero'ing out "strong" @synthesized properties in a -dealloc method.
14 //===----------------------------------------------------------------------===//
16 #include "Transforms.h"
17 #include "Internals.h"
19 using namespace clang;
20 using namespace arcmt;
21 using namespace trans;
25 class ZeroOutInDeallocRemover :
26 public RecursiveASTVisitor<ZeroOutInDeallocRemover> {
27 typedef RecursiveASTVisitor<ZeroOutInDeallocRemover> base;
31 llvm::DenseMap<ObjCPropertyDecl*, ObjCPropertyImplDecl*> SynthesizedProperties;
32 ImplicitParamDecl *SelfD;
37 ZeroOutInDeallocRemover(MigrationPass &pass) : Pass(pass), SelfD(0) {
39 Pass.Ctx.Selectors.getNullarySelector(&Pass.Ctx.Idents.get("finalize"));
42 bool VisitObjCMessageExpr(ObjCMessageExpr *ME) {
43 ASTContext &Ctx = Pass.Ctx;
44 TransformActions &TA = Pass.TA;
46 if (ME->getReceiverKind() != ObjCMessageExpr::Instance)
48 Expr *receiver = ME->getInstanceReceiver();
52 DeclRefExpr *refE = dyn_cast<DeclRefExpr>(receiver->IgnoreParenCasts());
53 if (!refE || refE->getDecl() != SelfD)
56 bool BackedBySynthesizeSetter = false;
57 for (llvm::DenseMap<ObjCPropertyDecl*, ObjCPropertyImplDecl*>::iterator
58 P = SynthesizedProperties.begin(),
59 E = SynthesizedProperties.end(); P != E; ++P) {
60 ObjCPropertyDecl *PropDecl = P->first;
61 if (PropDecl->getSetterName() == ME->getSelector()) {
62 BackedBySynthesizeSetter = true;
66 if (!BackedBySynthesizeSetter)
69 // Remove the setter message if RHS is null
70 Transaction Trans(TA);
71 Expr *RHS = ME->getArg(0);
73 RHS->isNullPointerConstant(Ctx,
74 Expr::NPC_ValueDependentIsNull);
75 if (RHSIsNull && isRemovable(ME))
81 bool VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
82 if (isZeroingPropIvar(POE) && isRemovable(POE)) {
83 Transaction Trans(Pass.TA);
84 Pass.TA.removeStmt(POE);
90 bool VisitBinaryOperator(BinaryOperator *BOE) {
91 if (isZeroingPropIvar(BOE) && isRemovable(BOE)) {
92 Transaction Trans(Pass.TA);
93 Pass.TA.removeStmt(BOE);
99 bool TraverseObjCMethodDecl(ObjCMethodDecl *D) {
100 if (D->getMethodFamily() != OMF_dealloc &&
101 !(D->isInstanceMethod() && D->getSelector() == FinalizeSel))
106 ObjCImplDecl *IMD = dyn_cast<ObjCImplDecl>(D->getDeclContext());
110 SelfD = D->getSelfDecl();
111 collectRemovables(D->getBody(), Removables);
113 // For a 'dealloc' method use, find all property implementations in
114 // this class implementation.
115 for (ObjCImplDecl::propimpl_iterator
116 I = IMD->propimpl_begin(), EI = IMD->propimpl_end(); I != EI; ++I) {
117 ObjCPropertyImplDecl *PID = *I;
118 if (PID->getPropertyImplementation() ==
119 ObjCPropertyImplDecl::Synthesize) {
120 ObjCPropertyDecl *PD = PID->getPropertyDecl();
121 ObjCMethodDecl *setterM = PD->getSetterMethodDecl();
122 if (!(setterM && setterM->isDefined())) {
123 ObjCPropertyDecl::PropertyAttributeKind AttrKind =
124 PD->getPropertyAttributes();
126 (ObjCPropertyDecl::OBJC_PR_retain |
127 ObjCPropertyDecl::OBJC_PR_copy |
128 ObjCPropertyDecl::OBJC_PR_strong))
129 SynthesizedProperties[PD] = PID;
134 // Now, remove all zeroing of ivars etc.
135 base::TraverseObjCMethodDecl(D);
137 // clear out for next method.
138 SynthesizedProperties.clear();
144 bool TraverseFunctionDecl(FunctionDecl *D) { return true; }
145 bool TraverseBlockDecl(BlockDecl *block) { return true; }
146 bool TraverseBlockExpr(BlockExpr *block) { return true; }
149 bool isRemovable(Expr *E) const {
150 return Removables.count(E);
153 bool isZeroingPropIvar(Expr *E) {
154 E = E->IgnoreParens();
155 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E))
156 return isZeroingPropIvar(BO);
157 if (PseudoObjectExpr *PO = dyn_cast<PseudoObjectExpr>(E))
158 return isZeroingPropIvar(PO);
162 bool isZeroingPropIvar(BinaryOperator *BOE) {
163 if (BOE->getOpcode() == BO_Comma)
164 return isZeroingPropIvar(BOE->getLHS()) &&
165 isZeroingPropIvar(BOE->getRHS());
167 if (BOE->getOpcode() != BO_Assign)
170 Expr *LHS = BOE->getLHS();
171 if (ObjCIvarRefExpr *IV = dyn_cast<ObjCIvarRefExpr>(LHS)) {
172 ObjCIvarDecl *IVDecl = IV->getDecl();
173 if (!IVDecl->getType()->isObjCObjectPointerType())
175 bool IvarBacksPropertySynthesis = false;
176 for (llvm::DenseMap<ObjCPropertyDecl*, ObjCPropertyImplDecl*>::iterator
177 P = SynthesizedProperties.begin(),
178 E = SynthesizedProperties.end(); P != E; ++P) {
179 ObjCPropertyImplDecl *PropImpDecl = P->second;
180 if (PropImpDecl && PropImpDecl->getPropertyIvarDecl() == IVDecl) {
181 IvarBacksPropertySynthesis = true;
185 if (!IvarBacksPropertySynthesis)
191 return isZero(BOE->getRHS());
194 bool isZeroingPropIvar(PseudoObjectExpr *PO) {
195 BinaryOperator *BO = dyn_cast<BinaryOperator>(PO->getSyntacticForm());
196 if (!BO) return false;
197 if (BO->getOpcode() != BO_Assign) return false;
199 ObjCPropertyRefExpr *PropRefExp =
200 dyn_cast<ObjCPropertyRefExpr>(BO->getLHS()->IgnoreParens());
201 if (!PropRefExp) return false;
203 // TODO: Using implicit property decl.
204 if (PropRefExp->isImplicitProperty())
207 if (ObjCPropertyDecl *PDecl = PropRefExp->getExplicitProperty()) {
208 if (!SynthesizedProperties.count(PDecl))
212 return isZero(cast<OpaqueValueExpr>(BO->getRHS())->getSourceExpr());
215 bool isZero(Expr *E) {
216 if (E->isNullPointerConstant(Pass.Ctx, Expr::NPC_ValueDependentIsNull))
219 return isZeroingPropIvar(E);
223 } // anonymous namespace
225 void trans::removeZeroOutPropsInDeallocFinalize(MigrationPass &pass) {
226 ZeroOutInDeallocRemover trans(pass);
227 trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl());