262 lines · cpp
1//===--- ScopeInfo.cpp - Information about a semantic context -------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements FunctionScopeInfo and its subclasses, which contain10// information about a single function, block, lambda, or method body.11//12//===----------------------------------------------------------------------===//13 14#include "clang/Sema/ScopeInfo.h"15#include "clang/AST/Decl.h"16#include "clang/AST/DeclObjC.h"17#include "clang/AST/Expr.h"18#include "clang/AST/ExprCXX.h"19#include "clang/AST/ExprObjC.h"20 21using namespace clang;22using namespace sema;23 24void FunctionScopeInfo::Clear() {25 HasBranchProtectedScope = false;26 HasBranchIntoScope = false;27 HasIndirectGoto = false;28 HasDroppedStmt = false;29 HasOMPDeclareReductionCombiner = false;30 HasFallthroughStmt = false;31 UsesFPIntrin = false;32 HasPotentialAvailabilityViolations = false;33 ObjCShouldCallSuper = false;34 ObjCIsDesignatedInit = false;35 ObjCWarnForNoDesignatedInitChain = false;36 ObjCIsSecondaryInit = false;37 ObjCWarnForNoInitDelegation = false;38 FirstReturnLoc = SourceLocation();39 FirstCXXOrObjCTryLoc = SourceLocation();40 FirstSEHTryLoc = SourceLocation();41 FirstVLALoc = SourceLocation();42 FoundImmediateEscalatingExpression = false;43 44 // Coroutine state45 FirstCoroutineStmtLoc = SourceLocation();46 CoroutinePromise = nullptr;47 CoroutineParameterMoves.clear();48 NeedsCoroutineSuspends = true;49 CoroutineSuspends.first = nullptr;50 CoroutineSuspends.second = nullptr;51 52 SwitchStack.clear();53 Returns.clear();54 ErrorTrap.reset();55 PossiblyUnreachableDiags.clear();56 WeakObjectUses.clear();57 ModifiedNonNullParams.clear();58 Blocks.clear();59 ByrefBlockVars.clear();60 AddrLabels.clear();61}62 63static const NamedDecl *getBestPropertyDecl(const ObjCPropertyRefExpr *PropE) {64 if (PropE->isExplicitProperty())65 return PropE->getExplicitProperty();66 67 return PropE->getImplicitPropertyGetter();68}69 70FunctionScopeInfo::WeakObjectProfileTy::BaseInfoTy71FunctionScopeInfo::WeakObjectProfileTy::getBaseInfo(const Expr *E) {72 E = E->IgnoreParenCasts();73 74 const NamedDecl *D = nullptr;75 bool IsExact = false;76 77 switch (E->getStmtClass()) {78 case Stmt::DeclRefExprClass:79 D = cast<DeclRefExpr>(E)->getDecl();80 IsExact = isa<VarDecl>(D);81 break;82 case Stmt::MemberExprClass: {83 const MemberExpr *ME = cast<MemberExpr>(E);84 D = ME->getMemberDecl();85 IsExact = isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts());86 break;87 }88 case Stmt::ObjCIvarRefExprClass: {89 const ObjCIvarRefExpr *IE = cast<ObjCIvarRefExpr>(E);90 D = IE->getDecl();91 IsExact = IE->getBase()->isObjCSelfExpr();92 break;93 }94 case Stmt::PseudoObjectExprClass: {95 const PseudoObjectExpr *POE = cast<PseudoObjectExpr>(E);96 const ObjCPropertyRefExpr *BaseProp =97 dyn_cast<ObjCPropertyRefExpr>(POE->getSyntacticForm());98 if (BaseProp) {99 D = getBestPropertyDecl(BaseProp);100 101 if (BaseProp->isObjectReceiver()) {102 const Expr *DoubleBase = BaseProp->getBase();103 if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(DoubleBase))104 DoubleBase = OVE->getSourceExpr();105 106 IsExact = DoubleBase->isObjCSelfExpr();107 }108 }109 break;110 }111 default:112 break;113 }114 115 return BaseInfoTy(D, IsExact);116}117 118FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(119 const ObjCPropertyRefExpr *PropE)120 : Base(nullptr, true), Property(getBestPropertyDecl(PropE)) {121 122 if (PropE->isObjectReceiver()) {123 const OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(PropE->getBase());124 const Expr *E = OVE->getSourceExpr();125 Base = getBaseInfo(E);126 } else if (PropE->isClassReceiver()) {127 Base.setPointer(PropE->getClassReceiver());128 } else {129 assert(PropE->isSuperReceiver());130 }131}132 133FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE,134 const ObjCPropertyDecl *Prop)135 : Base(nullptr, true), Property(Prop) {136 if (BaseE)137 Base = getBaseInfo(BaseE);138 // else, this is a message accessing a property on super.139}140 141FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(142 const DeclRefExpr *DRE)143 : Base(nullptr, true), Property(DRE->getDecl()) {144 assert(isa<VarDecl>(Property));145}146 147FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(148 const ObjCIvarRefExpr *IvarE)149 : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) {150}151 152void FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg,153 const ObjCPropertyDecl *Prop) {154 assert(Msg && Prop);155 WeakUseVector &Uses =156 WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)];157 Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0));158}159 160void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {161 E = E->IgnoreParenCasts();162 163 if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {164 markSafeWeakUse(POE->getSyntacticForm());165 return;166 }167 168 if (const ConditionalOperator *Cond = dyn_cast<ConditionalOperator>(E)) {169 markSafeWeakUse(Cond->getTrueExpr());170 markSafeWeakUse(Cond->getFalseExpr());171 return;172 }173 174 if (const BinaryConditionalOperator *Cond =175 dyn_cast<BinaryConditionalOperator>(E)) {176 markSafeWeakUse(Cond->getCommon());177 markSafeWeakUse(Cond->getFalseExpr());178 return;179 }180 181 // Has this weak object been seen before?182 FunctionScopeInfo::WeakObjectUseMap::iterator Uses = WeakObjectUses.end();183 if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) {184 if (!RefExpr->isObjectReceiver())185 return;186 if (isa<OpaqueValueExpr>(RefExpr->getBase()))187 Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr));188 else {189 markSafeWeakUse(RefExpr->getBase());190 return;191 }192 }193 else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E))194 Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));195 else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {196 if (isa<VarDecl>(DRE->getDecl()))197 Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));198 } else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {199 if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {200 if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {201 Uses =202 WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(),203 Prop));204 }205 }206 }207 else208 return;209 210 if (Uses == WeakObjectUses.end())211 return;212 213 // Has there been a read from the object using this Expr?214 FunctionScopeInfo::WeakUseVector::reverse_iterator ThisUse =215 llvm::find(llvm::reverse(Uses->second), WeakUseTy(E, true));216 if (ThisUse == Uses->second.rend())217 return;218 219 ThisUse->markSafe();220}221 222bool Capture::isInitCapture() const {223 // Note that a nested capture of an init-capture is not itself an224 // init-capture.225 return !isNested() && isVariableCapture() && getVariable()->isInitCapture();226}227 228bool CapturingScopeInfo::isVLATypeCaptured(const VariableArrayType *VAT) const {229 for (auto &Cap : Captures)230 if (Cap.isVLATypeCapture() && Cap.getCapturedVLAType() == VAT)231 return true;232 return false;233}234 235void LambdaScopeInfo::visitPotentialCaptures(236 llvm::function_ref<void(ValueDecl *, Expr *)> Callback) const {237 for (Expr *E : PotentiallyCapturingExprs) {238 if (auto *DRE = dyn_cast<DeclRefExpr>(E)) {239 Callback(cast<ValueDecl>(DRE->getFoundDecl()), E);240 } else if (auto *ME = dyn_cast<MemberExpr>(E)) {241 Callback(cast<ValueDecl>(ME->getMemberDecl()), E);242 } else if (auto *FP = dyn_cast<FunctionParmPackExpr>(E)) {243 for (ValueDecl *VD : *FP)244 Callback(VD, E);245 } else {246 llvm_unreachable("unexpected expression in potential captures list");247 }248 }249}250 251bool LambdaScopeInfo::lambdaCaptureShouldBeConst() const {252 if (ExplicitObjectParameter)253 return ExplicitObjectParameter->getType()254 .getNonReferenceType()255 .isConstQualified();256 return !Mutable;257}258 259FunctionScopeInfo::~FunctionScopeInfo() { }260BlockScopeInfo::~BlockScopeInfo() { }261CapturedRegionScopeInfo::~CapturedRegionScopeInfo() { }262