1 //===--- ScopeInfo.cpp - Information about a semantic context -------------===//
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 // This file implements FunctionScopeInfo and its subclasses, which contain
11 // information about a single function, block, lambda, or method body.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Sema/ScopeInfo.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
22 using namespace clang;
25 void FunctionScopeInfo::Clear() {
26 HasBranchProtectedScope = false;
27 HasBranchIntoScope = false;
28 HasIndirectGoto = false;
29 HasDroppedStmt = false;
30 ObjCShouldCallSuper = false;
31 ObjCIsDesignatedInit = false;
32 ObjCWarnForNoDesignatedInitChain = false;
33 ObjCIsSecondaryInit = false;
34 ObjCWarnForNoInitDelegation = false;
39 PossiblyUnreachableDiags.clear();
40 WeakObjectUses.clear();
43 static const NamedDecl *getBestPropertyDecl(const ObjCPropertyRefExpr *PropE) {
44 if (PropE->isExplicitProperty())
45 return PropE->getExplicitProperty();
47 return PropE->getImplicitPropertyGetter();
50 FunctionScopeInfo::WeakObjectProfileTy::BaseInfoTy
51 FunctionScopeInfo::WeakObjectProfileTy::getBaseInfo(const Expr *E) {
52 E = E->IgnoreParenCasts();
54 const NamedDecl *D = nullptr;
57 switch (E->getStmtClass()) {
58 case Stmt::DeclRefExprClass:
59 D = cast<DeclRefExpr>(E)->getDecl();
60 IsExact = isa<VarDecl>(D);
62 case Stmt::MemberExprClass: {
63 const MemberExpr *ME = cast<MemberExpr>(E);
64 D = ME->getMemberDecl();
65 IsExact = isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts());
68 case Stmt::ObjCIvarRefExprClass: {
69 const ObjCIvarRefExpr *IE = cast<ObjCIvarRefExpr>(E);
71 IsExact = IE->getBase()->isObjCSelfExpr();
74 case Stmt::PseudoObjectExprClass: {
75 const PseudoObjectExpr *POE = cast<PseudoObjectExpr>(E);
76 const ObjCPropertyRefExpr *BaseProp =
77 dyn_cast<ObjCPropertyRefExpr>(POE->getSyntacticForm());
79 D = getBestPropertyDecl(BaseProp);
81 const Expr *DoubleBase = BaseProp->getBase();
82 if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(DoubleBase))
83 DoubleBase = OVE->getSourceExpr();
85 IsExact = DoubleBase->isObjCSelfExpr();
93 return BaseInfoTy(D, IsExact);
96 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
97 const ObjCPropertyRefExpr *PropE)
98 : Base(nullptr, true), Property(getBestPropertyDecl(PropE)) {
100 if (PropE->isObjectReceiver()) {
101 const OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(PropE->getBase());
102 const Expr *E = OVE->getSourceExpr();
103 Base = getBaseInfo(E);
104 } else if (PropE->isClassReceiver()) {
105 Base.setPointer(PropE->getClassReceiver());
107 assert(PropE->isSuperReceiver());
111 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE,
112 const ObjCPropertyDecl *Prop)
113 : Base(nullptr, true), Property(Prop) {
115 Base = getBaseInfo(BaseE);
116 // else, this is a message accessing a property on super.
119 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
120 const DeclRefExpr *DRE)
121 : Base(nullptr, true), Property(DRE->getDecl()) {
122 assert(isa<VarDecl>(Property));
125 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
126 const ObjCIvarRefExpr *IvarE)
127 : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) {
130 void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg,
131 const ObjCPropertyDecl *Prop) {
133 WeakUseVector &Uses =
134 WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)];
135 Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0));
138 void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
139 E = E->IgnoreParenCasts();
141 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
142 markSafeWeakUse(POE->getSyntacticForm());
146 if (const ConditionalOperator *Cond = dyn_cast<ConditionalOperator>(E)) {
147 markSafeWeakUse(Cond->getTrueExpr());
148 markSafeWeakUse(Cond->getFalseExpr());
152 if (const BinaryConditionalOperator *Cond =
153 dyn_cast<BinaryConditionalOperator>(E)) {
154 markSafeWeakUse(Cond->getCommon());
155 markSafeWeakUse(Cond->getFalseExpr());
159 // Has this weak object been seen before?
160 FunctionScopeInfo::WeakObjectUseMap::iterator Uses;
161 if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) {
162 if (isa<OpaqueValueExpr>(RefExpr->getBase()))
163 Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr));
165 markSafeWeakUse(RefExpr->getBase());
169 else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E))
170 Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));
171 else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
172 Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
173 else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {
174 Uses = WeakObjectUses.end();
175 if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {
176 if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {
178 WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(),
186 if (Uses == WeakObjectUses.end())
189 // Has there been a read from the object using this Expr?
190 FunctionScopeInfo::WeakUseVector::reverse_iterator ThisUse =
191 std::find(Uses->second.rbegin(), Uses->second.rend(), WeakUseTy(E, true));
192 if (ThisUse == Uses->second.rend())
198 void LambdaScopeInfo::getPotentialVariableCapture(unsigned Idx, VarDecl *&VD,
200 assert(Idx < getNumPotentialVariableCaptures() &&
201 "Index of potential capture must be within 0 to less than the "
202 "number of captures!");
203 E = PotentiallyCapturingExprs[Idx];
204 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
205 VD = dyn_cast<VarDecl>(DRE->getFoundDecl());
206 else if (MemberExpr *ME = dyn_cast<MemberExpr>(E))
207 VD = dyn_cast<VarDecl>(ME->getMemberDecl());
209 llvm_unreachable("Only DeclRefExprs or MemberExprs should be added for "
210 "potential captures");
214 FunctionScopeInfo::~FunctionScopeInfo() { }
215 BlockScopeInfo::~BlockScopeInfo() { }
216 LambdaScopeInfo::~LambdaScopeInfo() { }
217 CapturedRegionScopeInfo::~CapturedRegionScopeInfo() { }