ExprEngineCXX.cpp revision 200fa2e70d52ae6d620e81cd45536071fdde70c0
1//===- ExprEngineCXX.cpp - ExprEngine support for C++ -----------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines the C++ expression evaluation engine. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/StaticAnalyzer/Core/CheckerManager.h" 15#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 16#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 17#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" 18#include "clang/AST/DeclCXX.h" 19#include "clang/AST/StmtCXX.h" 20#include "clang/Basic/PrettyStackTrace.h" 21 22using namespace clang; 23using namespace ento; 24 25void ExprEngine::CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 26 ExplodedNode *Pred, 27 ExplodedNodeSet &Dst) { 28 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 29 const Expr *tempExpr = ME->GetTemporaryExpr()->IgnoreParens(); 30 ProgramStateRef state = Pred->getState(); 31 const LocationContext *LCtx = Pred->getLocationContext(); 32 33 // Bind the temporary object to the value of the expression. Then bind 34 // the expression to the location of the object. 35 SVal V = state->getSVal(tempExpr, LCtx); 36 37 // If the value is already a CXXTempObjectRegion, it is fine as it is. 38 // Otherwise, create a new CXXTempObjectRegion, and copy the value into it. 39 const MemRegion *MR = V.getAsRegion(); 40 if (!MR || !isa<CXXTempObjectRegion>(MR)) { 41 const MemRegion *R = 42 svalBuilder.getRegionManager().getCXXTempObjectRegion(ME, LCtx); 43 44 SVal L = loc::MemRegionVal(R); 45 state = state->bindLoc(L, V); 46 V = L; 47 } 48 49 Bldr.generateNode(ME, Pred, state->BindExpr(ME, LCtx, V)); 50} 51 52void ExprEngine::VisitCXXConstructExpr(const CXXConstructExpr *CE, 53 ExplodedNode *Pred, 54 ExplodedNodeSet &destNodes) { 55 const LocationContext *LCtx = Pred->getLocationContext(); 56 ProgramStateRef State = Pred->getState(); 57 58 const MemRegion *Target = 0; 59 60 switch (CE->getConstructionKind()) { 61 case CXXConstructExpr::CK_Complete: { 62 // See if we're constructing an existing region by looking at the next 63 // element in the CFG. 64 const CFGBlock *B = currBldrCtx->getBlock(); 65 if (currStmtIdx + 1 < B->size()) { 66 CFGElement Next = (*B)[currStmtIdx+1]; 67 68 // Is this a constructor for a local variable? 69 if (const CFGStmt *StmtElem = dyn_cast<CFGStmt>(&Next)) { 70 if (const DeclStmt *DS = dyn_cast<DeclStmt>(StmtElem->getStmt())) { 71 if (const VarDecl *Var = dyn_cast<VarDecl>(DS->getSingleDecl())) { 72 if (Var->getInit()->IgnoreImplicit() == CE) { 73 QualType Ty = Var->getType(); 74 if (const ArrayType *AT = getContext().getAsArrayType(Ty)) { 75 // FIXME: Handle arrays, which run the same constructor for 76 // every element. This workaround will just run the first 77 // constructor (which should still invalidate the entire array). 78 SVal Base = State->getLValue(Var, LCtx); 79 Target = State->getLValue(AT->getElementType(), 80 getSValBuilder().makeZeroArrayIndex(), 81 Base).getAsRegion(); 82 } else { 83 Target = State->getLValue(Var, LCtx).getAsRegion(); 84 } 85 } 86 } 87 } 88 } 89 90 // Is this a constructor for a member? 91 if (const CFGInitializer *InitElem = dyn_cast<CFGInitializer>(&Next)) { 92 const CXXCtorInitializer *Init = InitElem->getInitializer(); 93 assert(Init->isAnyMemberInitializer()); 94 95 const CXXMethodDecl *CurCtor = cast<CXXMethodDecl>(LCtx->getDecl()); 96 Loc ThisPtr = getSValBuilder().getCXXThis(CurCtor, 97 LCtx->getCurrentStackFrame()); 98 SVal ThisVal = State->getSVal(ThisPtr); 99 100 if (Init->isIndirectMemberInitializer()) { 101 SVal Field = State->getLValue(Init->getIndirectMember(), ThisVal); 102 Target = Field.getAsRegion(); 103 } else { 104 SVal Field = State->getLValue(Init->getMember(), ThisVal); 105 Target = Field.getAsRegion(); 106 } 107 } 108 109 // FIXME: This will eventually need to handle new-expressions as well. 110 } 111 112 // If we couldn't find an existing region to construct into, assume we're 113 // constructing a temporary. 114 if (!Target) { 115 MemRegionManager &MRMgr = getSValBuilder().getRegionManager(); 116 Target = MRMgr.getCXXTempObjectRegion(CE, LCtx); 117 } 118 119 break; 120 } 121 case CXXConstructExpr::CK_NonVirtualBase: 122 case CXXConstructExpr::CK_VirtualBase: 123 case CXXConstructExpr::CK_Delegating: { 124 const CXXMethodDecl *CurCtor = cast<CXXMethodDecl>(LCtx->getDecl()); 125 Loc ThisPtr = getSValBuilder().getCXXThis(CurCtor, 126 LCtx->getCurrentStackFrame()); 127 SVal ThisVal = State->getSVal(ThisPtr); 128 129 if (CE->getConstructionKind() == CXXConstructExpr::CK_Delegating) { 130 Target = ThisVal.getAsRegion(); 131 } else { 132 // Cast to the base type. 133 QualType BaseTy = CE->getType(); 134 SVal BaseVal = getStoreManager().evalDerivedToBase(ThisVal, BaseTy); 135 Target = BaseVal.getAsRegion(); 136 } 137 break; 138 } 139 } 140 141 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 142 CallEventRef<CXXConstructorCall> Call = 143 CEMgr.getCXXConstructorCall(CE, Target, State, LCtx); 144 145 ExplodedNodeSet DstPreVisit; 146 getCheckerManager().runCheckersForPreStmt(DstPreVisit, Pred, CE, *this); 147 ExplodedNodeSet DstPreCall; 148 getCheckerManager().runCheckersForPreCall(DstPreCall, DstPreVisit, 149 *Call, *this); 150 151 ExplodedNodeSet DstInvalidated; 152 StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currBldrCtx); 153 for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); 154 I != E; ++I) 155 defaultEvalCall(Bldr, *I, *Call); 156 157 ExplodedNodeSet DstPostCall; 158 getCheckerManager().runCheckersForPostCall(DstPostCall, DstInvalidated, 159 *Call, *this); 160 getCheckerManager().runCheckersForPostStmt(destNodes, DstPostCall, CE, *this); 161} 162 163void ExprEngine::VisitCXXDestructor(QualType ObjectType, 164 const MemRegion *Dest, 165 const Stmt *S, 166 bool IsBaseDtor, 167 ExplodedNode *Pred, 168 ExplodedNodeSet &Dst) { 169 const LocationContext *LCtx = Pred->getLocationContext(); 170 ProgramStateRef State = Pred->getState(); 171 172 // FIXME: We need to run the same destructor on every element of the array. 173 // This workaround will just run the first destructor (which will still 174 // invalidate the entire array). 175 if (const ArrayType *AT = getContext().getAsArrayType(ObjectType)) { 176 ObjectType = AT->getElementType(); 177 Dest = State->getLValue(ObjectType, getSValBuilder().makeZeroArrayIndex(), 178 loc::MemRegionVal(Dest)).getAsRegion(); 179 } 180 181 const CXXRecordDecl *RecordDecl = ObjectType->getAsCXXRecordDecl(); 182 assert(RecordDecl && "Only CXXRecordDecls should have destructors"); 183 const CXXDestructorDecl *DtorDecl = RecordDecl->getDestructor(); 184 185 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 186 CallEventRef<CXXDestructorCall> Call = 187 CEMgr.getCXXDestructorCall(DtorDecl, S, Dest, IsBaseDtor, State, LCtx); 188 189 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(), 190 Call->getSourceRange().getBegin(), 191 "Error evaluating destructor"); 192 193 ExplodedNodeSet DstPreCall; 194 getCheckerManager().runCheckersForPreCall(DstPreCall, Pred, 195 *Call, *this); 196 197 ExplodedNodeSet DstInvalidated; 198 StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currBldrCtx); 199 for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); 200 I != E; ++I) 201 defaultEvalCall(Bldr, *I, *Call); 202 203 ExplodedNodeSet DstPostCall; 204 getCheckerManager().runCheckersForPostCall(Dst, DstInvalidated, 205 *Call, *this); 206} 207 208void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 209 ExplodedNodeSet &Dst) { 210 // FIXME: Much of this should eventually migrate to CXXAllocatorCall. 211 // Also, we need to decide how allocators actually work -- they're not 212 // really part of the CXXNewExpr because they happen BEFORE the 213 // CXXConstructExpr subexpression. See PR12014 for some discussion. 214 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 215 216 unsigned blockCount = currBldrCtx->blockCount(); 217 const LocationContext *LCtx = Pred->getLocationContext(); 218 DefinedOrUnknownSVal symVal = svalBuilder.conjureSymbolVal(0, CNE, LCtx, 219 CNE->getType(), 220 blockCount); 221 ProgramStateRef State = Pred->getState(); 222 223 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 224 CallEventRef<CXXAllocatorCall> Call = 225 CEMgr.getCXXAllocatorCall(CNE, State, LCtx); 226 227 // Invalidate placement args. 228 // FIXME: Once we figure out how we want allocators to work, 229 // we should be using the usual pre-/(default-)eval-/post-call checks here. 230 State = Call->invalidateRegions(blockCount); 231 232 if (CNE->isArray()) { 233 // FIXME: allocating an array requires simulating the constructors. 234 // For now, just return a symbolicated region. 235 const MemRegion *NewReg = cast<loc::MemRegionVal>(symVal).getRegion(); 236 QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); 237 const ElementRegion *EleReg = 238 getStoreManager().GetElementZeroRegion(NewReg, ObjTy); 239 State = State->BindExpr(CNE, Pred->getLocationContext(), 240 loc::MemRegionVal(EleReg)); 241 Bldr.generateNode(CNE, Pred, State); 242 return; 243 } 244 245 // FIXME: Once we have proper support for CXXConstructExprs inside 246 // CXXNewExpr, we need to make sure that the constructed object is not 247 // immediately invalidated here. (The placement call should happen before 248 // the constructor call anyway.) 249 FunctionDecl *FD = CNE->getOperatorNew(); 250 if (FD && FD->isReservedGlobalPlacementOperator()) { 251 // Non-array placement new should always return the placement location. 252 SVal PlacementLoc = State->getSVal(CNE->getPlacementArg(0), LCtx); 253 State = State->BindExpr(CNE, LCtx, PlacementLoc); 254 } else { 255 State = State->BindExpr(CNE, LCtx, symVal); 256 } 257 258 // If the type is not a record, we won't have a CXXConstructExpr as an 259 // initializer. Copy the value over. 260 if (const Expr *Init = CNE->getInitializer()) { 261 if (!isa<CXXConstructExpr>(Init)) { 262 QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); 263 (void)ObjTy; 264 assert(!ObjTy->isRecordType()); 265 SVal Location = State->getSVal(CNE, LCtx); 266 if (isa<Loc>(Location)) 267 State = State->bindLoc(cast<Loc>(Location), State->getSVal(Init, LCtx)); 268 } 269 } 270 271 Bldr.generateNode(CNE, Pred, State); 272} 273 274void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, 275 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 276 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 277 ProgramStateRef state = Pred->getState(); 278 Bldr.generateNode(CDE, Pred, state); 279} 280 281void ExprEngine::VisitCXXCatchStmt(const CXXCatchStmt *CS, 282 ExplodedNode *Pred, 283 ExplodedNodeSet &Dst) { 284 const VarDecl *VD = CS->getExceptionDecl(); 285 if (!VD) { 286 Dst.Add(Pred); 287 return; 288 } 289 290 const LocationContext *LCtx = Pred->getLocationContext(); 291 SVal V = svalBuilder.conjureSymbolVal(CS, LCtx, VD->getType(), 292 currBldrCtx->blockCount()); 293 ProgramStateRef state = Pred->getState(); 294 state = state->bindLoc(state->getLValue(VD, LCtx), V); 295 296 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 297 Bldr.generateNode(CS, Pred, state); 298} 299 300void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 301 ExplodedNodeSet &Dst) { 302 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 303 304 // Get the this object region from StoreManager. 305 const LocationContext *LCtx = Pred->getLocationContext(); 306 const MemRegion *R = 307 svalBuilder.getRegionManager().getCXXThisRegion( 308 getContext().getCanonicalType(TE->getType()), 309 LCtx); 310 311 ProgramStateRef state = Pred->getState(); 312 SVal V = state->getSVal(loc::MemRegionVal(R)); 313 Bldr.generateNode(TE, Pred, state->BindExpr(TE, LCtx, V)); 314} 315