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/DeclCXX.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
21 #include "clang/AST/ExprObjC.h"
23 using namespace clang;
26 void FunctionScopeInfo::Clear() {
27 HasBranchProtectedScope = false;
28 HasBranchIntoScope = false;
29 HasIndirectGoto = false;
30 HasDroppedStmt = false;
31 ObjCShouldCallSuper = false;
32 ObjCIsDesignatedInit = false;
33 ObjCWarnForNoDesignatedInitChain = false;
34 ObjCIsSecondaryInit = false;
35 ObjCWarnForNoInitDelegation = false;
36 FirstCXXTryLoc = SourceLocation();
37 FirstSEHTryLoc = SourceLocation();
42 PossiblyUnreachableDiags.clear();
43 WeakObjectUses.clear();
44 ModifiedNonNullParams.clear();
47 static const NamedDecl *getBestPropertyDecl(const ObjCPropertyRefExpr *PropE) {
48 if (PropE->isExplicitProperty())
49 return PropE->getExplicitProperty();
51 return PropE->getImplicitPropertyGetter();
54 FunctionScopeInfo::WeakObjectProfileTy::BaseInfoTy
55 FunctionScopeInfo::WeakObjectProfileTy::getBaseInfo(const Expr *E) {
56 E = E->IgnoreParenCasts();
58 const NamedDecl *D = nullptr;
61 switch (E->getStmtClass()) {
62 case Stmt::DeclRefExprClass:
63 D = cast<DeclRefExpr>(E)->getDecl();
64 IsExact = isa<VarDecl>(D);
66 case Stmt::MemberExprClass: {
67 const MemberExpr *ME = cast<MemberExpr>(E);
68 D = ME->getMemberDecl();
69 IsExact = isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts());
72 case Stmt::ObjCIvarRefExprClass: {
73 const ObjCIvarRefExpr *IE = cast<ObjCIvarRefExpr>(E);
75 IsExact = IE->getBase()->isObjCSelfExpr();
78 case Stmt::PseudoObjectExprClass: {
79 const PseudoObjectExpr *POE = cast<PseudoObjectExpr>(E);
80 const ObjCPropertyRefExpr *BaseProp =
81 dyn_cast<ObjCPropertyRefExpr>(POE->getSyntacticForm());
83 D = getBestPropertyDecl(BaseProp);
85 const Expr *DoubleBase = BaseProp->getBase();
86 if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(DoubleBase))
87 DoubleBase = OVE->getSourceExpr();
89 IsExact = DoubleBase->isObjCSelfExpr();
97 return BaseInfoTy(D, IsExact);
100 bool CapturingScopeInfo::isVLATypeCaptured(const VariableArrayType *VAT) const {
101 RecordDecl *RD = nullptr;
102 if (auto *LSI = dyn_cast<LambdaScopeInfo>(this))
104 else if (auto CRSI = dyn_cast<CapturedRegionScopeInfo>(this))
105 RD = CRSI->TheRecordDecl;
108 for (auto *FD : RD->fields()) {
109 if (FD->hasCapturedVLAType() && FD->getCapturedVLAType() == VAT)
115 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
116 const ObjCPropertyRefExpr *PropE)
117 : Base(nullptr, true), Property(getBestPropertyDecl(PropE)) {
119 if (PropE->isObjectReceiver()) {
120 const OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(PropE->getBase());
121 const Expr *E = OVE->getSourceExpr();
122 Base = getBaseInfo(E);
123 } else if (PropE->isClassReceiver()) {
124 Base.setPointer(PropE->getClassReceiver());
126 assert(PropE->isSuperReceiver());
130 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE,
131 const ObjCPropertyDecl *Prop)
132 : Base(nullptr, true), Property(Prop) {
134 Base = getBaseInfo(BaseE);
135 // else, this is a message accessing a property on super.
138 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
139 const DeclRefExpr *DRE)
140 : Base(nullptr, true), Property(DRE->getDecl()) {
141 assert(isa<VarDecl>(Property));
144 FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
145 const ObjCIvarRefExpr *IvarE)
146 : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) {
149 void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg,
150 const ObjCPropertyDecl *Prop) {
152 WeakUseVector &Uses =
153 WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)];
154 Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0));
157 void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
158 E = E->IgnoreParenCasts();
160 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
161 markSafeWeakUse(POE->getSyntacticForm());
165 if (const ConditionalOperator *Cond = dyn_cast<ConditionalOperator>(E)) {
166 markSafeWeakUse(Cond->getTrueExpr());
167 markSafeWeakUse(Cond->getFalseExpr());
171 if (const BinaryConditionalOperator *Cond =
172 dyn_cast<BinaryConditionalOperator>(E)) {
173 markSafeWeakUse(Cond->getCommon());
174 markSafeWeakUse(Cond->getFalseExpr());
178 // Has this weak object been seen before?
179 FunctionScopeInfo::WeakObjectUseMap::iterator Uses;
180 if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) {
181 if (!RefExpr->isObjectReceiver())
183 if (isa<OpaqueValueExpr>(RefExpr->getBase()))
184 Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr));
186 markSafeWeakUse(RefExpr->getBase());
190 else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E))
191 Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));
192 else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
193 Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
194 else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {
195 Uses = WeakObjectUses.end();
196 if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {
197 if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {
199 WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(),
207 if (Uses == WeakObjectUses.end())
210 // Has there been a read from the object using this Expr?
211 FunctionScopeInfo::WeakUseVector::reverse_iterator ThisUse =
212 std::find(Uses->second.rbegin(), Uses->second.rend(), WeakUseTy(E, true));
213 if (ThisUse == Uses->second.rend())
219 void LambdaScopeInfo::getPotentialVariableCapture(unsigned Idx, VarDecl *&VD,
221 assert(Idx < getNumPotentialVariableCaptures() &&
222 "Index of potential capture must be within 0 to less than the "
223 "number of captures!");
224 E = PotentiallyCapturingExprs[Idx];
225 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
226 VD = dyn_cast<VarDecl>(DRE->getFoundDecl());
227 else if (MemberExpr *ME = dyn_cast<MemberExpr>(E))
228 VD = dyn_cast<VarDecl>(ME->getMemberDecl());
230 llvm_unreachable("Only DeclRefExprs or MemberExprs should be added for "
231 "potential captures");
235 FunctionScopeInfo::~FunctionScopeInfo() { }
236 BlockScopeInfo::~BlockScopeInfo() { }
237 LambdaScopeInfo::~LambdaScopeInfo() { }
238 CapturedRegionScopeInfo::~CapturedRegionScopeInfo() { }