ExprEngineCXX.cpp revision 6ebea89be233eaba5e29de8cf3524ad150c860bb
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 ExplodedNode *Pred, 167 ExplodedNodeSet &Dst) { 168 const LocationContext *LCtx = Pred->getLocationContext(); 169 ProgramStateRef State = Pred->getState(); 170 171 // FIXME: We need to run the same destructor on every element of the array. 172 // This workaround will just run the first destructor (which will still 173 // invalidate the entire array). 174 if (const ArrayType *AT = getContext().getAsArrayType(ObjectType)) { 175 ObjectType = AT->getElementType(); 176 Dest = State->getLValue(ObjectType, getSValBuilder().makeZeroArrayIndex(), 177 loc::MemRegionVal(Dest)).getAsRegion(); 178 } 179 180 const CXXRecordDecl *RecordDecl = ObjectType->getAsCXXRecordDecl(); 181 assert(RecordDecl && "Only CXXRecordDecls should have destructors"); 182 const CXXDestructorDecl *DtorDecl = RecordDecl->getDestructor(); 183 184 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 185 CallEventRef<CXXDestructorCall> Call = 186 CEMgr.getCXXDestructorCall(DtorDecl, S, Dest, State, LCtx); 187 188 PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(), 189 Call->getSourceRange().getBegin(), 190 "Error evaluating destructor"); 191 192 ExplodedNodeSet DstPreCall; 193 getCheckerManager().runCheckersForPreCall(DstPreCall, Pred, 194 *Call, *this); 195 196 ExplodedNodeSet DstInvalidated; 197 StmtNodeBuilder Bldr(DstPreCall, DstInvalidated, *currBldrCtx); 198 for (ExplodedNodeSet::iterator I = DstPreCall.begin(), E = DstPreCall.end(); 199 I != E; ++I) 200 defaultEvalCall(Bldr, *I, *Call); 201 202 ExplodedNodeSet DstPostCall; 203 getCheckerManager().runCheckersForPostCall(Dst, DstInvalidated, 204 *Call, *this); 205} 206 207void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 208 ExplodedNodeSet &Dst) { 209 // FIXME: Much of this should eventually migrate to CXXAllocatorCall. 210 // Also, we need to decide how allocators actually work -- they're not 211 // really part of the CXXNewExpr because they happen BEFORE the 212 // CXXConstructExpr subexpression. See PR12014 for some discussion. 213 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 214 215 unsigned blockCount = currBldrCtx->blockCount(); 216 const LocationContext *LCtx = Pred->getLocationContext(); 217 DefinedOrUnknownSVal symVal = svalBuilder.conjureSymbolVal(0, CNE, LCtx, 218 CNE->getType(), 219 blockCount); 220 ProgramStateRef State = Pred->getState(); 221 222 CallEventManager &CEMgr = getStateManager().getCallEventManager(); 223 CallEventRef<CXXAllocatorCall> Call = 224 CEMgr.getCXXAllocatorCall(CNE, State, LCtx); 225 226 // Invalidate placement args. 227 // FIXME: Once we figure out how we want allocators to work, 228 // we should be using the usual pre-/(default-)eval-/post-call checks here. 229 State = Call->invalidateRegions(blockCount); 230 231 if (CNE->isArray()) { 232 // FIXME: allocating an array requires simulating the constructors. 233 // For now, just return a symbolicated region. 234 const MemRegion *NewReg = cast<loc::MemRegionVal>(symVal).getRegion(); 235 QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); 236 const ElementRegion *EleReg = 237 getStoreManager().GetElementZeroRegion(NewReg, ObjTy); 238 State = State->BindExpr(CNE, Pred->getLocationContext(), 239 loc::MemRegionVal(EleReg)); 240 Bldr.generateNode(CNE, Pred, State); 241 return; 242 } 243 244 // FIXME: Once we have proper support for CXXConstructExprs inside 245 // CXXNewExpr, we need to make sure that the constructed object is not 246 // immediately invalidated here. (The placement call should happen before 247 // the constructor call anyway.) 248 FunctionDecl *FD = CNE->getOperatorNew(); 249 if (FD && FD->isReservedGlobalPlacementOperator()) { 250 // Non-array placement new should always return the placement location. 251 SVal PlacementLoc = State->getSVal(CNE->getPlacementArg(0), LCtx); 252 State = State->BindExpr(CNE, LCtx, PlacementLoc); 253 } else { 254 State = State->BindExpr(CNE, LCtx, symVal); 255 } 256 257 // If the type is not a record, we won't have a CXXConstructExpr as an 258 // initializer. Copy the value over. 259 if (const Expr *Init = CNE->getInitializer()) { 260 if (!isa<CXXConstructExpr>(Init)) { 261 QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType(); 262 (void)ObjTy; 263 assert(!ObjTy->isRecordType()); 264 SVal Location = State->getSVal(CNE, LCtx); 265 if (isa<Loc>(Location)) 266 State = State->bindLoc(cast<Loc>(Location), State->getSVal(Init, LCtx)); 267 } 268 } 269 270 Bldr.generateNode(CNE, Pred, State); 271} 272 273void ExprEngine::VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, 274 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 275 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 276 ProgramStateRef state = Pred->getState(); 277 Bldr.generateNode(CDE, Pred, state); 278} 279 280void ExprEngine::VisitCXXCatchStmt(const CXXCatchStmt *CS, 281 ExplodedNode *Pred, 282 ExplodedNodeSet &Dst) { 283 const VarDecl *VD = CS->getExceptionDecl(); 284 if (!VD) { 285 Dst.Add(Pred); 286 return; 287 } 288 289 const LocationContext *LCtx = Pred->getLocationContext(); 290 SVal V = svalBuilder.conjureSymbolVal(CS, LCtx, VD->getType(), 291 currBldrCtx->blockCount()); 292 ProgramStateRef state = Pred->getState(); 293 state = state->bindLoc(state->getLValue(VD, LCtx), V); 294 295 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 296 Bldr.generateNode(CS, Pred, state); 297} 298 299void ExprEngine::VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 300 ExplodedNodeSet &Dst) { 301 StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 302 303 // Get the this object region from StoreManager. 304 const LocationContext *LCtx = Pred->getLocationContext(); 305 const MemRegion *R = 306 svalBuilder.getRegionManager().getCXXThisRegion( 307 getContext().getCanonicalType(TE->getType()), 308 LCtx); 309 310 ProgramStateRef state = Pred->getState(); 311 SVal V = state->getSVal(loc::MemRegionVal(R)); 312 Bldr.generateNode(TE, Pred, state->BindExpr(TE, LCtx, V)); 313} 314