1243791Sdim//===--- ScopeInfo.cpp - Information about a semantic context -------------===// 2243791Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6243791Sdim// 7243791Sdim//===----------------------------------------------------------------------===// 8243791Sdim// 9243791Sdim// This file implements FunctionScopeInfo and its subclasses, which contain 10243791Sdim// information about a single function, block, lambda, or method body. 11243791Sdim// 12243791Sdim//===----------------------------------------------------------------------===// 13243791Sdim 14243791Sdim#include "clang/Sema/ScopeInfo.h" 15243791Sdim#include "clang/AST/Decl.h" 16280031Sdim#include "clang/AST/DeclCXX.h" 17243791Sdim#include "clang/AST/DeclObjC.h" 18243791Sdim#include "clang/AST/Expr.h" 19243791Sdim#include "clang/AST/ExprCXX.h" 20243791Sdim#include "clang/AST/ExprObjC.h" 21243791Sdim 22243791Sdimusing namespace clang; 23243791Sdimusing namespace sema; 24243791Sdim 25243791Sdimvoid FunctionScopeInfo::Clear() { 26243791Sdim HasBranchProtectedScope = false; 27243791Sdim HasBranchIntoScope = false; 28243791Sdim HasIndirectGoto = false; 29276479Sdim HasDroppedStmt = false; 30309124Sdim HasOMPDeclareReductionCombiner = false; 31314564Sdim HasFallthroughStmt = false; 32314564Sdim HasPotentialAvailabilityViolations = false; 33276479Sdim ObjCShouldCallSuper = false; 34276479Sdim ObjCIsDesignatedInit = false; 35276479Sdim ObjCWarnForNoDesignatedInitChain = false; 36276479Sdim ObjCIsSecondaryInit = false; 37276479Sdim ObjCWarnForNoInitDelegation = false; 38296417Sdim FirstReturnLoc = SourceLocation(); 39288943Sdim FirstCXXTryLoc = SourceLocation(); 40288943Sdim FirstSEHTryLoc = SourceLocation(); 41243791Sdim 42321369Sdim // Coroutine state 43321369Sdim FirstCoroutineStmtLoc = SourceLocation(); 44321369Sdim CoroutinePromise = nullptr; 45341825Sdim CoroutineParameterMoves.clear(); 46321369Sdim NeedsCoroutineSuspends = true; 47321369Sdim CoroutineSuspends.first = nullptr; 48321369Sdim CoroutineSuspends.second = nullptr; 49321369Sdim 50243791Sdim SwitchStack.clear(); 51243791Sdim Returns.clear(); 52243791Sdim ErrorTrap.reset(); 53243791Sdim PossiblyUnreachableDiags.clear(); 54243791Sdim WeakObjectUses.clear(); 55280031Sdim ModifiedNonNullParams.clear(); 56344779Sdim Blocks.clear(); 57344779Sdim ByrefBlockVars.clear(); 58243791Sdim} 59243791Sdim 60243791Sdimstatic const NamedDecl *getBestPropertyDecl(const ObjCPropertyRefExpr *PropE) { 61243791Sdim if (PropE->isExplicitProperty()) 62243791Sdim return PropE->getExplicitProperty(); 63243791Sdim 64243791Sdim return PropE->getImplicitPropertyGetter(); 65243791Sdim} 66243791Sdim 67243791SdimFunctionScopeInfo::WeakObjectProfileTy::BaseInfoTy 68243791SdimFunctionScopeInfo::WeakObjectProfileTy::getBaseInfo(const Expr *E) { 69243791Sdim E = E->IgnoreParenCasts(); 70243791Sdim 71276479Sdim const NamedDecl *D = nullptr; 72243791Sdim bool IsExact = false; 73243791Sdim 74243791Sdim switch (E->getStmtClass()) { 75243791Sdim case Stmt::DeclRefExprClass: 76243791Sdim D = cast<DeclRefExpr>(E)->getDecl(); 77243791Sdim IsExact = isa<VarDecl>(D); 78243791Sdim break; 79243791Sdim case Stmt::MemberExprClass: { 80243791Sdim const MemberExpr *ME = cast<MemberExpr>(E); 81243791Sdim D = ME->getMemberDecl(); 82243791Sdim IsExact = isa<CXXThisExpr>(ME->getBase()->IgnoreParenImpCasts()); 83243791Sdim break; 84243791Sdim } 85243791Sdim case Stmt::ObjCIvarRefExprClass: { 86243791Sdim const ObjCIvarRefExpr *IE = cast<ObjCIvarRefExpr>(E); 87243791Sdim D = IE->getDecl(); 88243791Sdim IsExact = IE->getBase()->isObjCSelfExpr(); 89243791Sdim break; 90243791Sdim } 91243791Sdim case Stmt::PseudoObjectExprClass: { 92243791Sdim const PseudoObjectExpr *POE = cast<PseudoObjectExpr>(E); 93243791Sdim const ObjCPropertyRefExpr *BaseProp = 94243791Sdim dyn_cast<ObjCPropertyRefExpr>(POE->getSyntacticForm()); 95243791Sdim if (BaseProp) { 96243791Sdim D = getBestPropertyDecl(BaseProp); 97243791Sdim 98309124Sdim if (BaseProp->isObjectReceiver()) { 99309124Sdim const Expr *DoubleBase = BaseProp->getBase(); 100309124Sdim if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(DoubleBase)) 101309124Sdim DoubleBase = OVE->getSourceExpr(); 102243791Sdim 103309124Sdim IsExact = DoubleBase->isObjCSelfExpr(); 104309124Sdim } 105243791Sdim } 106243791Sdim break; 107243791Sdim } 108243791Sdim default: 109243791Sdim break; 110243791Sdim } 111243791Sdim 112243791Sdim return BaseInfoTy(D, IsExact); 113243791Sdim} 114243791Sdim 115243791SdimFunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 116243791Sdim const ObjCPropertyRefExpr *PropE) 117276479Sdim : Base(nullptr, true), Property(getBestPropertyDecl(PropE)) { 118243791Sdim 119243791Sdim if (PropE->isObjectReceiver()) { 120243791Sdim const OpaqueValueExpr *OVE = cast<OpaqueValueExpr>(PropE->getBase()); 121243791Sdim const Expr *E = OVE->getSourceExpr(); 122243791Sdim Base = getBaseInfo(E); 123243791Sdim } else if (PropE->isClassReceiver()) { 124243791Sdim Base.setPointer(PropE->getClassReceiver()); 125243791Sdim } else { 126243791Sdim assert(PropE->isSuperReceiver()); 127243791Sdim } 128243791Sdim} 129243791Sdim 130243791SdimFunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(const Expr *BaseE, 131243791Sdim const ObjCPropertyDecl *Prop) 132276479Sdim : Base(nullptr, true), Property(Prop) { 133243791Sdim if (BaseE) 134243791Sdim Base = getBaseInfo(BaseE); 135243791Sdim // else, this is a message accessing a property on super. 136243791Sdim} 137243791Sdim 138243791SdimFunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 139243791Sdim const DeclRefExpr *DRE) 140276479Sdim : Base(nullptr, true), Property(DRE->getDecl()) { 141243791Sdim assert(isa<VarDecl>(Property)); 142243791Sdim} 143243791Sdim 144243791SdimFunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy( 145243791Sdim const ObjCIvarRefExpr *IvarE) 146243791Sdim : Base(getBaseInfo(IvarE->getBase())), Property(IvarE->getDecl()) { 147243791Sdim} 148243791Sdim 149243791Sdimvoid FunctionScopeInfo::recordUseOfWeak(const ObjCMessageExpr *Msg, 150243791Sdim const ObjCPropertyDecl *Prop) { 151243791Sdim assert(Msg && Prop); 152243791Sdim WeakUseVector &Uses = 153243791Sdim WeakObjectUses[WeakObjectProfileTy(Msg->getInstanceReceiver(), Prop)]; 154243791Sdim Uses.push_back(WeakUseTy(Msg, Msg->getNumArgs() == 0)); 155243791Sdim} 156243791Sdim 157243791Sdimvoid FunctionScopeInfo::markSafeWeakUse(const Expr *E) { 158243791Sdim E = E->IgnoreParenCasts(); 159243791Sdim 160243791Sdim if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { 161243791Sdim markSafeWeakUse(POE->getSyntacticForm()); 162243791Sdim return; 163243791Sdim } 164243791Sdim 165243791Sdim if (const ConditionalOperator *Cond = dyn_cast<ConditionalOperator>(E)) { 166243791Sdim markSafeWeakUse(Cond->getTrueExpr()); 167243791Sdim markSafeWeakUse(Cond->getFalseExpr()); 168243791Sdim return; 169243791Sdim } 170243791Sdim 171243791Sdim if (const BinaryConditionalOperator *Cond = 172243791Sdim dyn_cast<BinaryConditionalOperator>(E)) { 173243791Sdim markSafeWeakUse(Cond->getCommon()); 174243791Sdim markSafeWeakUse(Cond->getFalseExpr()); 175243791Sdim return; 176243791Sdim } 177243791Sdim 178243791Sdim // Has this weak object been seen before? 179321369Sdim FunctionScopeInfo::WeakObjectUseMap::iterator Uses = WeakObjectUses.end(); 180276479Sdim if (const ObjCPropertyRefExpr *RefExpr = dyn_cast<ObjCPropertyRefExpr>(E)) { 181280031Sdim if (!RefExpr->isObjectReceiver()) 182280031Sdim return; 183276479Sdim if (isa<OpaqueValueExpr>(RefExpr->getBase())) 184276479Sdim Uses = WeakObjectUses.find(WeakObjectProfileTy(RefExpr)); 185276479Sdim else { 186276479Sdim markSafeWeakUse(RefExpr->getBase()); 187276479Sdim return; 188276479Sdim } 189276479Sdim } 190243791Sdim else if (const ObjCIvarRefExpr *IvarE = dyn_cast<ObjCIvarRefExpr>(E)) 191243791Sdim Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE)); 192321369Sdim else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) { 193321369Sdim if (isa<VarDecl>(DRE->getDecl())) 194321369Sdim Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE)); 195321369Sdim } else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) { 196243791Sdim if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) { 197243791Sdim if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) { 198243791Sdim Uses = 199243791Sdim WeakObjectUses.find(WeakObjectProfileTy(MsgE->getInstanceReceiver(), 200243791Sdim Prop)); 201243791Sdim } 202243791Sdim } 203243791Sdim } 204243791Sdim else 205243791Sdim return; 206243791Sdim 207243791Sdim if (Uses == WeakObjectUses.end()) 208243791Sdim return; 209243791Sdim 210243791Sdim // Has there been a read from the object using this Expr? 211243791Sdim FunctionScopeInfo::WeakUseVector::reverse_iterator ThisUse = 212309124Sdim llvm::find(llvm::reverse(Uses->second), WeakUseTy(E, true)); 213243791Sdim if (ThisUse == Uses->second.rend()) 214243791Sdim return; 215243791Sdim 216243791Sdim ThisUse->markSafe(); 217243791Sdim} 218243791Sdim 219353358Sdimbool Capture::isInitCapture() const { 220353358Sdim // Note that a nested capture of an init-capture is not itself an 221353358Sdim // init-capture. 222353358Sdim return !isNested() && isVariableCapture() && getVariable()->isInitCapture(); 223261991Sdim} 224261991Sdim 225353358Sdimbool CapturingScopeInfo::isVLATypeCaptured(const VariableArrayType *VAT) const { 226353358Sdim for (auto &Cap : Captures) 227353358Sdim if (Cap.isVLATypeCapture() && Cap.getCapturedVLAType() == VAT) 228353358Sdim return true; 229353358Sdim return false; 230353358Sdim} 231353358Sdim 232353358Sdimvoid LambdaScopeInfo::visitPotentialCaptures( 233353358Sdim llvm::function_ref<void(VarDecl *, Expr *)> Callback) const { 234353358Sdim for (Expr *E : PotentiallyCapturingExprs) { 235353358Sdim if (auto *DRE = dyn_cast<DeclRefExpr>(E)) { 236353358Sdim Callback(cast<VarDecl>(DRE->getFoundDecl()), E); 237353358Sdim } else if (auto *ME = dyn_cast<MemberExpr>(E)) { 238353358Sdim Callback(cast<VarDecl>(ME->getMemberDecl()), E); 239353358Sdim } else if (auto *FP = dyn_cast<FunctionParmPackExpr>(E)) { 240353358Sdim for (VarDecl *VD : *FP) 241353358Sdim Callback(VD, E); 242353358Sdim } else { 243353358Sdim llvm_unreachable("unexpected expression in potential captures list"); 244353358Sdim } 245353358Sdim } 246353358Sdim} 247353358Sdim 248243791SdimFunctionScopeInfo::~FunctionScopeInfo() { } 249243791SdimBlockScopeInfo::~BlockScopeInfo() { } 250251662SdimCapturedRegionScopeInfo::~CapturedRegionScopeInfo() { } 251