ScopeInfo.cpp revision 243791
1115140Strhodes//===--- ScopeInfo.cpp - Information about a semantic context -------------===// 2115140Strhodes// 3115140Strhodes// The LLVM Compiler Infrastructure 4115140Strhodes// 5115140Strhodes// This file is distributed under the University of Illinois Open Source 6115140Strhodes// License. See LICENSE.TXT for details. 7115140Strhodes// 8115140Strhodes//===----------------------------------------------------------------------===// 9115140Strhodes// 10115140Strhodes// This file implements FunctionScopeInfo and its subclasses, which contain 11115140Strhodes// information about a single function, block, lambda, or method body. 12115140Strhodes// 13115140Strhodes//===----------------------------------------------------------------------===// 14115140Strhodes 15115140Strhodes#include "clang/Sema/ScopeInfo.h" 16115140Strhodes#include "clang/AST/Decl.h" 17115140Strhodes#include "clang/AST/DeclObjC.h" 18115140Strhodes#include "clang/AST/Expr.h" 19115140Strhodes#include "clang/AST/ExprCXX.h" 20115140Strhodes#include "clang/AST/ExprObjC.h" 21115140Strhodes 22115140Strhodesusing namespace clang; 23115140Strhodesusing namespace sema; 24115140Strhodes 25115140Strhodesvoid FunctionScopeInfo::Clear() { 26115140Strhodes HasBranchProtectedScope = false; 27115140Strhodes HasBranchIntoScope = false; 28115140Strhodes HasIndirectGoto = false; 29115140Strhodes 30115140Strhodes SwitchStack.clear(); 31115140Strhodes Returns.clear(); 32232507Seadler ErrorTrap.reset(); 33115140Strhodes PossiblyUnreachableDiags.clear(); 34115140Strhodes WeakObjectUses.clear(); 35115140Strhodes} 36115140Strhodes 37115140Strhodesstatic const NamedDecl *getBestPropertyDecl(const ObjCPropertyRefExpr *PropE) { 38115140Strhodes if (PropE->isExplicitProperty()) 39115140Strhodes return PropE->getExplicitProperty(); 40115140Strhodes 41115140Strhodes return PropE->getImplicitPropertyGetter(); 42115140Strhodes} 43115140Strhodes 44115140StrhodesFunctionScopeInfo::WeakObjectProfileTy::BaseInfoTy 45115140StrhodesFunctionScopeInfo::WeakObjectProfileTy::getBaseInfo(const Expr *E) { 46115140Strhodes E = E->IgnoreParenCasts(); 47115140Strhodes 48115140Strhodes const NamedDecl *D = 0; 49115140Strhodes bool IsExact = false; 50115140Strhodes 51115140Strhodes switch (E->getStmtClass()) { 52115140Strhodes case Stmt::DeclRefExprClass: 53115140Strhodes D = cast<DeclRefExpr>(E)->getDecl(); 54115140Strhodes IsExact = isa<VarDecl>(D); 55115140Strhodes break; 56115140Strhodes case Stmt::MemberExprClass: { 57115140Strhodes const MemberExpr *ME = cast<MemberExpr>(E); 58115140Strhodes D = ME->getMemberDecl(); 59115140Strhodes IsExact = isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts()); 60115140Strhodes break; 61115140Strhodes } 62115140Strhodes case Stmt::ObjCIvarRefExprClass: { 63115140Strhodes const ObjCIvarRefExpr *IE = cast<ObjCIvarRefExpr>(E); 64115140Strhodes D = IE->getDecl(); 65115140Strhodes IsExact = IE->getBase()->isObjCSelfExpr(); 66115140Strhodes break; 67115140Strhodes } 68115140Strhodes case Stmt::PseudoObjectExprClass: { 69115140Strhodes const PseudoObjectExpr *POE = cast<PseudoObjectExpr>(E); 70115140Strhodes const ObjCPropertyRefExpr *BaseProp = 71115140Strhodes dyn_cast<ObjCPropertyRefExpr>(POE->getSyntacticForm()); 72115140Strhodes if (BaseProp) { 73219004Shselasky D = getBestPropertyDecl(BaseProp); 74115140Strhodes 75115140Strhodes const Expr *DoubleBase = BaseProp->getBase(); 76115140Strhodes if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(DoubleBase)) 77115140Strhodes DoubleBase = OVE->getSourceExpr(); 78115140Strhodes 79115140Strhodes IsExact = DoubleBase->isObjCSelfExpr(); 80115140Strhodes } 81115140Strhodes break; 82219004Shselasky } 83232501Seadler default: 84232501Seadler break; 85232501Seadler } 86232501Seadler 87232501Seadler return BaseInfoTy(D, IsExact); 88219004Shselasky} 89219004Shselasky 90219004Shselasky 91219004ShselaskyFunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 92219004Shselasky const ObjCPropertyRefExpr *PropE) 93219004Shselasky : Base(0, true), Property(getBestPropertyDecl(PropE)) { 94219004Shselasky 95219004Shselasky if (PropE->isObjectReceiver()) { 96219004Shselasky const OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(PropE->getBase()); 97219004Shselasky const Expr *E = OVE->getSourceExpr(); 98219004Shselasky Base = getBaseInfo(E); 99219004Shselasky } else if (PropE->isClassReceiver()) { 100219004Shselasky Base.setPointer(PropE->getClassReceiver()); 101219004Shselasky } else { 102 assert(PropE->isSuperReceiver()); 103 } 104} 105 106FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE, 107 const ObjCPropertyDecl *Prop) 108 : Base(0, true), Property(Prop) { 109 if (BaseE) 110 Base = getBaseInfo(BaseE); 111 // else, this is a message accessing a property on super. 112} 113 114FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 115 const DeclRefExpr *DRE) 116 : Base(0, true), Property(DRE->getDecl()) { 117 assert(isa<VarDecl>(Property)); 118} 119 120FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 121 const ObjCIvarRefExpr *IvarE) 122 : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) { 123} 124 125void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg, 126 const ObjCPropertyDecl *Prop) { 127 assert(Msg && Prop); 128 WeakUseVector &Uses = 129 WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)]; 130 Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0)); 131} 132 133void FunctionScopeInfo::markSafeWeakUse(const Expr *E) { 134 E = E->IgnoreParenCasts(); 135 136 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 137 markSafeWeakUse(POE->getSyntacticForm()); 138 return; 139 } 140 141 if (const ConditionalOperator *Cond = dyn_cast<ConditionalOperator>(E)) { 142 markSafeWeakUse(Cond->getTrueExpr()); 143 markSafeWeakUse(Cond->getFalseExpr()); 144 return; 145 } 146 147 if (const BinaryConditionalOperator *Cond = 148 dyn_cast<BinaryConditionalOperator>(E)) { 149 markSafeWeakUse(Cond->getCommon()); 150 markSafeWeakUse(Cond->getFalseExpr()); 151 return; 152 } 153 154 // Has this weak object been seen before? 155 FunctionScopeInfo::WeakObjectUseMap::iterator Uses; 156 if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) 157 Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr)); 158 else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E)) 159 Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE)); 160 else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) 161 Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE)); 162 else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) { 163 Uses = WeakObjectUses.end(); 164 if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) { 165 if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) { 166 Uses = 167 WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(), 168 Prop)); 169 } 170 } 171 } 172 else 173 return; 174 175 if (Uses == WeakObjectUses.end()) 176 return; 177 178 // Has there been a read from the object using this Expr? 179 FunctionScopeInfo::WeakUseVector::reverse_iterator ThisUse = 180 std::find(Uses->second.rbegin(), Uses->second.rend(), WeakUseTy(E, true)); 181 if (ThisUse == Uses->second.rend()) 182 return; 183 184 ThisUse->markSafe(); 185} 186 187FunctionScopeInfo::~FunctionScopeInfo() { } 188BlockScopeInfo::~BlockScopeInfo() { } 189LambdaScopeInfo::~LambdaScopeInfo() { } 190