ExprEngineC.cpp revision 251662
1226586Sdim//=-- ExprEngineC.cpp - ExprEngine support for C expressions ----*- C++ -*-===// 2226586Sdim// 3226586Sdim// The LLVM Compiler Infrastructure 4226586Sdim// 5226586Sdim// This file is distributed under the University of Illinois Open Source 6226586Sdim// License. See LICENSE.TXT for details. 7226586Sdim// 8226586Sdim//===----------------------------------------------------------------------===// 9226586Sdim// 10226586Sdim// This file defines ExprEngine's support for C expressions. 11226586Sdim// 12226586Sdim//===----------------------------------------------------------------------===// 13226586Sdim 14249423Sdim#include "clang/AST/ExprCXX.h" 15226586Sdim#include "clang/StaticAnalyzer/Core/CheckerManager.h" 16226586Sdim#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 17226586Sdim 18226586Sdimusing namespace clang; 19226586Sdimusing namespace ento; 20226586Sdimusing llvm::APSInt; 21226586Sdim 22226586Sdimvoid ExprEngine::VisitBinaryOperator(const BinaryOperator* B, 23226586Sdim ExplodedNode *Pred, 24226586Sdim ExplodedNodeSet &Dst) { 25226586Sdim 26226586Sdim Expr *LHS = B->getLHS()->IgnoreParens(); 27226586Sdim Expr *RHS = B->getRHS()->IgnoreParens(); 28226586Sdim 29226586Sdim // FIXME: Prechecks eventually go in ::Visit(). 30226586Sdim ExplodedNodeSet CheckedSet; 31226586Sdim ExplodedNodeSet Tmp2; 32226586Sdim getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, B, *this); 33226586Sdim 34226586Sdim // With both the LHS and RHS evaluated, process the operation itself. 35226586Sdim for (ExplodedNodeSet::iterator it=CheckedSet.begin(), ei=CheckedSet.end(); 36226586Sdim it != ei; ++it) { 37226586Sdim 38234353Sdim ProgramStateRef state = (*it)->getState(); 39234353Sdim const LocationContext *LCtx = (*it)->getLocationContext(); 40234353Sdim SVal LeftV = state->getSVal(LHS, LCtx); 41234353Sdim SVal RightV = state->getSVal(RHS, LCtx); 42226586Sdim 43226586Sdim BinaryOperator::Opcode Op = B->getOpcode(); 44226586Sdim 45226586Sdim if (Op == BO_Assign) { 46226586Sdim // EXPERIMENTAL: "Conjured" symbols. 47226586Sdim // FIXME: Handle structs. 48234353Sdim if (RightV.isUnknown()) { 49243830Sdim unsigned Count = currBldrCtx->blockCount(); 50243830Sdim RightV = svalBuilder.conjureSymbolVal(0, B->getRHS(), LCtx, Count); 51226586Sdim } 52226586Sdim // Simulate the effects of a "store": bind the value of the RHS 53226586Sdim // to the L-Value represented by the LHS. 54239462Sdim SVal ExprVal = B->isGLValue() ? LeftV : RightV; 55234353Sdim evalStore(Tmp2, B, LHS, *it, state->BindExpr(B, LCtx, ExprVal), 56234353Sdim LeftV, RightV); 57226586Sdim continue; 58226586Sdim } 59226586Sdim 60226586Sdim if (!B->isAssignmentOp()) { 61243830Sdim StmtNodeBuilder Bldr(*it, Tmp2, *currBldrCtx); 62239462Sdim 63239462Sdim if (B->isAdditiveOp()) { 64239462Sdim // If one of the operands is a location, conjure a symbol for the other 65239462Sdim // one (offset) if it's unknown so that memory arithmetic always 66239462Sdim // results in an ElementRegion. 67239462Sdim // TODO: This can be removed after we enable history tracking with 68239462Sdim // SymSymExpr. 69243830Sdim unsigned Count = currBldrCtx->blockCount(); 70249423Sdim if (LeftV.getAs<Loc>() && 71251662Sdim RHS->getType()->isIntegralOrEnumerationType() && 72251662Sdim RightV.isUnknown()) { 73243830Sdim RightV = svalBuilder.conjureSymbolVal(RHS, LCtx, RHS->getType(), 74243830Sdim Count); 75239462Sdim } 76249423Sdim if (RightV.getAs<Loc>() && 77251662Sdim LHS->getType()->isIntegralOrEnumerationType() && 78251662Sdim LeftV.isUnknown()) { 79243830Sdim LeftV = svalBuilder.conjureSymbolVal(LHS, LCtx, LHS->getType(), 80243830Sdim Count); 81239462Sdim } 82239462Sdim } 83239462Sdim 84226586Sdim // Process non-assignments except commas or short-circuited 85226586Sdim // logical expressions (LAnd and LOr). 86226586Sdim SVal Result = evalBinOp(state, Op, LeftV, RightV, B->getType()); 87226586Sdim if (Result.isUnknown()) { 88234353Sdim Bldr.generateNode(B, *it, state); 89226586Sdim continue; 90226586Sdim } 91226586Sdim 92234353Sdim state = state->BindExpr(B, LCtx, Result); 93234353Sdim Bldr.generateNode(B, *it, state); 94226586Sdim continue; 95226586Sdim } 96226586Sdim 97226586Sdim assert (B->isCompoundAssignmentOp()); 98226586Sdim 99226586Sdim switch (Op) { 100226586Sdim default: 101226586Sdim llvm_unreachable("Invalid opcode for compound assignment."); 102226586Sdim case BO_MulAssign: Op = BO_Mul; break; 103226586Sdim case BO_DivAssign: Op = BO_Div; break; 104226586Sdim case BO_RemAssign: Op = BO_Rem; break; 105226586Sdim case BO_AddAssign: Op = BO_Add; break; 106226586Sdim case BO_SubAssign: Op = BO_Sub; break; 107226586Sdim case BO_ShlAssign: Op = BO_Shl; break; 108226586Sdim case BO_ShrAssign: Op = BO_Shr; break; 109226586Sdim case BO_AndAssign: Op = BO_And; break; 110226586Sdim case BO_XorAssign: Op = BO_Xor; break; 111226586Sdim case BO_OrAssign: Op = BO_Or; break; 112226586Sdim } 113226586Sdim 114226586Sdim // Perform a load (the LHS). This performs the checks for 115226586Sdim // null dereferences, and so on. 116226586Sdim ExplodedNodeSet Tmp; 117226586Sdim SVal location = LeftV; 118234353Sdim evalLoad(Tmp, B, LHS, *it, state, location); 119226586Sdim 120226586Sdim for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end(); I != E; 121226586Sdim ++I) { 122226586Sdim 123226586Sdim state = (*I)->getState(); 124234353Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 125234353Sdim SVal V = state->getSVal(LHS, LCtx); 126226586Sdim 127226586Sdim // Get the computation type. 128226586Sdim QualType CTy = 129226586Sdim cast<CompoundAssignOperator>(B)->getComputationResultType(); 130226586Sdim CTy = getContext().getCanonicalType(CTy); 131226586Sdim 132226586Sdim QualType CLHSTy = 133226586Sdim cast<CompoundAssignOperator>(B)->getComputationLHSType(); 134226586Sdim CLHSTy = getContext().getCanonicalType(CLHSTy); 135226586Sdim 136226586Sdim QualType LTy = getContext().getCanonicalType(LHS->getType()); 137226586Sdim 138226586Sdim // Promote LHS. 139226586Sdim V = svalBuilder.evalCast(V, CLHSTy, LTy); 140226586Sdim 141226586Sdim // Compute the result of the operation. 142226586Sdim SVal Result = svalBuilder.evalCast(evalBinOp(state, Op, V, RightV, CTy), 143226586Sdim B->getType(), CTy); 144226586Sdim 145226586Sdim // EXPERIMENTAL: "Conjured" symbols. 146226586Sdim // FIXME: Handle structs. 147226586Sdim 148226586Sdim SVal LHSVal; 149226586Sdim 150234353Sdim if (Result.isUnknown()) { 151226586Sdim // The symbolic value is actually for the type of the left-hand side 152226586Sdim // expression, not the computation type, as this is the value the 153226586Sdim // LValue on the LHS will bind to. 154243830Sdim LHSVal = svalBuilder.conjureSymbolVal(0, B->getRHS(), LCtx, LTy, 155243830Sdim currBldrCtx->blockCount()); 156226586Sdim // However, we need to convert the symbol to the computation type. 157226586Sdim Result = svalBuilder.evalCast(LHSVal, CTy, LTy); 158226586Sdim } 159226586Sdim else { 160226586Sdim // The left-hand side may bind to a different value then the 161226586Sdim // computation type. 162226586Sdim LHSVal = svalBuilder.evalCast(Result, LTy, CTy); 163226586Sdim } 164226586Sdim 165226586Sdim // In C++, assignment and compound assignment operators return an 166226586Sdim // lvalue. 167239462Sdim if (B->isGLValue()) 168234353Sdim state = state->BindExpr(B, LCtx, location); 169226586Sdim else 170234353Sdim state = state->BindExpr(B, LCtx, Result); 171226586Sdim 172226586Sdim evalStore(Tmp2, B, LHS, *I, state, location, LHSVal); 173226586Sdim } 174226586Sdim } 175226586Sdim 176226586Sdim // FIXME: postvisits eventually go in ::Visit() 177226586Sdim getCheckerManager().runCheckersForPostStmt(Dst, Tmp2, B, *this); 178226586Sdim} 179226586Sdim 180226586Sdimvoid ExprEngine::VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 181226586Sdim ExplodedNodeSet &Dst) { 182226586Sdim 183226586Sdim CanQualType T = getContext().getCanonicalType(BE->getType()); 184239462Sdim 185239462Sdim // Get the value of the block itself. 186226586Sdim SVal V = svalBuilder.getBlockPointer(BE->getBlockDecl(), T, 187226586Sdim Pred->getLocationContext()); 188226586Sdim 189239462Sdim ProgramStateRef State = Pred->getState(); 190239462Sdim 191239462Sdim // If we created a new MemRegion for the block, we should explicitly bind 192239462Sdim // the captured variables. 193239462Sdim if (const BlockDataRegion *BDR = 194239462Sdim dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) { 195239462Sdim 196239462Sdim BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 197239462Sdim E = BDR->referenced_vars_end(); 198239462Sdim 199239462Sdim for (; I != E; ++I) { 200239462Sdim const MemRegion *capturedR = I.getCapturedRegion(); 201239462Sdim const MemRegion *originalR = I.getOriginalRegion(); 202239462Sdim if (capturedR != originalR) { 203239462Sdim SVal originalV = State->getSVal(loc::MemRegionVal(originalR)); 204239462Sdim State = State->bindLoc(loc::MemRegionVal(capturedR), originalV); 205239462Sdim } 206239462Sdim } 207239462Sdim } 208239462Sdim 209226586Sdim ExplodedNodeSet Tmp; 210243830Sdim StmtNodeBuilder Bldr(Pred, Tmp, *currBldrCtx); 211234353Sdim Bldr.generateNode(BE, Pred, 212239462Sdim State->BindExpr(BE, Pred->getLocationContext(), V), 213243830Sdim 0, ProgramPoint::PostLValueKind); 214226586Sdim 215226586Sdim // FIXME: Move all post/pre visits to ::Visit(). 216226586Sdim getCheckerManager().runCheckersForPostStmt(Dst, Tmp, BE, *this); 217226586Sdim} 218226586Sdim 219226586Sdimvoid ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex, 220226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 221226586Sdim 222226586Sdim ExplodedNodeSet dstPreStmt; 223226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreStmt, Pred, CastE, *this); 224226586Sdim 225234353Sdim if (CastE->getCastKind() == CK_LValueToRValue) { 226226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 227226586Sdim I!=E; ++I) { 228226586Sdim ExplodedNode *subExprNode = *I; 229234353Sdim ProgramStateRef state = subExprNode->getState(); 230234353Sdim const LocationContext *LCtx = subExprNode->getLocationContext(); 231234353Sdim evalLoad(Dst, CastE, CastE, subExprNode, state, state->getSVal(Ex, LCtx)); 232226586Sdim } 233226586Sdim return; 234226586Sdim } 235226586Sdim 236226586Sdim // All other casts. 237226586Sdim QualType T = CastE->getType(); 238226586Sdim QualType ExTy = Ex->getType(); 239226586Sdim 240226586Sdim if (const ExplicitCastExpr *ExCast=dyn_cast_or_null<ExplicitCastExpr>(CastE)) 241226586Sdim T = ExCast->getTypeAsWritten(); 242226586Sdim 243243830Sdim StmtNodeBuilder Bldr(dstPreStmt, Dst, *currBldrCtx); 244226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 245226586Sdim I != E; ++I) { 246226586Sdim 247226586Sdim Pred = *I; 248243830Sdim ProgramStateRef state = Pred->getState(); 249243830Sdim const LocationContext *LCtx = Pred->getLocationContext(); 250243830Sdim 251226586Sdim switch (CastE->getCastKind()) { 252226586Sdim case CK_LValueToRValue: 253226586Sdim llvm_unreachable("LValueToRValue casts handled earlier."); 254226586Sdim case CK_ToVoid: 255226586Sdim continue; 256226586Sdim // The analyzer doesn't do anything special with these casts, 257226586Sdim // since it understands retain/release semantics already. 258226586Sdim case CK_ARCProduceObject: 259226586Sdim case CK_ARCConsumeObject: 260226586Sdim case CK_ARCReclaimReturnedObject: 261226586Sdim case CK_ARCExtendBlockObject: // Fall-through. 262234353Sdim case CK_CopyAndAutoreleaseBlockObject: 263234353Sdim // The analyser can ignore atomic casts for now, although some future 264234353Sdim // checkers may want to make certain that you're not modifying the same 265234353Sdim // value through atomic and nonatomic pointers. 266234353Sdim case CK_AtomicToNonAtomic: 267234353Sdim case CK_NonAtomicToAtomic: 268226586Sdim // True no-ops. 269226586Sdim case CK_NoOp: 270243830Sdim case CK_ConstructorConversion: 271243830Sdim case CK_UserDefinedConversion: 272243830Sdim case CK_FunctionToPointerDecay: 273243830Sdim case CK_BuiltinFnToFnPtr: { 274226586Sdim // Copy the SVal of Ex to CastE. 275234353Sdim ProgramStateRef state = Pred->getState(); 276234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 277234353Sdim SVal V = state->getSVal(Ex, LCtx); 278234353Sdim state = state->BindExpr(CastE, LCtx, V); 279234353Sdim Bldr.generateNode(CastE, Pred, state); 280226586Sdim continue; 281226586Sdim } 282243830Sdim case CK_MemberPointerToBoolean: 283243830Sdim // FIXME: For now, member pointers are represented by void *. 284243830Sdim // FALLTHROUGH 285226586Sdim case CK_Dependent: 286226586Sdim case CK_ArrayToPointerDecay: 287226586Sdim case CK_BitCast: 288226586Sdim case CK_IntegralCast: 289226586Sdim case CK_NullToPointer: 290226586Sdim case CK_IntegralToPointer: 291226586Sdim case CK_PointerToIntegral: 292226586Sdim case CK_PointerToBoolean: 293226586Sdim case CK_IntegralToBoolean: 294226586Sdim case CK_IntegralToFloating: 295226586Sdim case CK_FloatingToIntegral: 296226586Sdim case CK_FloatingToBoolean: 297226586Sdim case CK_FloatingCast: 298226586Sdim case CK_FloatingRealToComplex: 299226586Sdim case CK_FloatingComplexToReal: 300226586Sdim case CK_FloatingComplexToBoolean: 301226586Sdim case CK_FloatingComplexCast: 302226586Sdim case CK_FloatingComplexToIntegralComplex: 303226586Sdim case CK_IntegralRealToComplex: 304226586Sdim case CK_IntegralComplexToReal: 305226586Sdim case CK_IntegralComplexToBoolean: 306226586Sdim case CK_IntegralComplexCast: 307226586Sdim case CK_IntegralComplexToFloatingComplex: 308226586Sdim case CK_CPointerToObjCPointerCast: 309226586Sdim case CK_BlockPointerToObjCPointerCast: 310226586Sdim case CK_AnyPointerToBlockPointerCast: 311249423Sdim case CK_ObjCObjectLValueCast: 312249423Sdim case CK_ZeroToOCLEvent: { 313226586Sdim // Delegate to SValBuilder to process. 314234353Sdim SVal V = state->getSVal(Ex, LCtx); 315226586Sdim V = svalBuilder.evalCast(V, T, ExTy); 316234353Sdim state = state->BindExpr(CastE, LCtx, V); 317234353Sdim Bldr.generateNode(CastE, Pred, state); 318226586Sdim continue; 319226586Sdim } 320226586Sdim case CK_DerivedToBase: 321226586Sdim case CK_UncheckedDerivedToBase: { 322226586Sdim // For DerivedToBase cast, delegate to the store manager. 323234353Sdim SVal val = state->getSVal(Ex, LCtx); 324239462Sdim val = getStoreManager().evalDerivedToBase(val, CastE); 325234353Sdim state = state->BindExpr(CastE, LCtx, val); 326234353Sdim Bldr.generateNode(CastE, Pred, state); 327226586Sdim continue; 328226586Sdim } 329234353Sdim // Handle C++ dyn_cast. 330234353Sdim case CK_Dynamic: { 331234353Sdim SVal val = state->getSVal(Ex, LCtx); 332234353Sdim 333234353Sdim // Compute the type of the result. 334234353Sdim QualType resultType = CastE->getType(); 335239462Sdim if (CastE->isGLValue()) 336234353Sdim resultType = getContext().getPointerType(resultType); 337234353Sdim 338234353Sdim bool Failed = false; 339234353Sdim 340234353Sdim // Check if the value being cast evaluates to 0. 341234353Sdim if (val.isZeroConstant()) 342234353Sdim Failed = true; 343234353Sdim // Else, evaluate the cast. 344234353Sdim else 345234353Sdim val = getStoreManager().evalDynamicCast(val, T, Failed); 346234353Sdim 347234353Sdim if (Failed) { 348234353Sdim if (T->isReferenceType()) { 349234353Sdim // A bad_cast exception is thrown if input value is a reference. 350234353Sdim // Currently, we model this, by generating a sink. 351243830Sdim Bldr.generateSink(CastE, Pred, state); 352234353Sdim continue; 353234353Sdim } else { 354234353Sdim // If the cast fails on a pointer, bind to 0. 355234353Sdim state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull()); 356234353Sdim } 357234353Sdim } else { 358234353Sdim // If we don't know if the cast succeeded, conjure a new symbol. 359234353Sdim if (val.isUnknown()) { 360243830Sdim DefinedOrUnknownSVal NewSym = 361243830Sdim svalBuilder.conjureSymbolVal(0, CastE, LCtx, resultType, 362243830Sdim currBldrCtx->blockCount()); 363234353Sdim state = state->BindExpr(CastE, LCtx, NewSym); 364234353Sdim } else 365234353Sdim // Else, bind to the derived region value. 366234353Sdim state = state->BindExpr(CastE, LCtx, val); 367234353Sdim } 368234353Sdim Bldr.generateNode(CastE, Pred, state); 369234353Sdim continue; 370234353Sdim } 371243830Sdim case CK_NullToMemberPointer: { 372243830Sdim // FIXME: For now, member pointers are represented by void *. 373243830Sdim SVal V = svalBuilder.makeIntValWithPtrWidth(0, true); 374243830Sdim state = state->BindExpr(CastE, LCtx, V); 375243830Sdim Bldr.generateNode(CastE, Pred, state); 376243830Sdim continue; 377243830Sdim } 378234353Sdim // Various C++ casts that are not handled yet. 379226586Sdim case CK_ToUnion: 380226586Sdim case CK_BaseToDerived: 381226586Sdim case CK_BaseToDerivedMemberPointer: 382226586Sdim case CK_DerivedToBaseMemberPointer: 383234353Sdim case CK_ReinterpretMemberPointer: 384226586Sdim case CK_VectorSplat: 385239462Sdim case CK_LValueBitCast: { 386226586Sdim // Recover some path-sensitivty by conjuring a new value. 387226586Sdim QualType resultType = CastE->getType(); 388239462Sdim if (CastE->isGLValue()) 389226586Sdim resultType = getContext().getPointerType(resultType); 390243830Sdim SVal result = svalBuilder.conjureSymbolVal(0, CastE, LCtx, 391243830Sdim resultType, 392243830Sdim currBldrCtx->blockCount()); 393243830Sdim state = state->BindExpr(CastE, LCtx, result); 394234353Sdim Bldr.generateNode(CastE, Pred, state); 395226586Sdim continue; 396226586Sdim } 397226586Sdim } 398226586Sdim } 399226586Sdim} 400226586Sdim 401226586Sdimvoid ExprEngine::VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 402226586Sdim ExplodedNode *Pred, 403226586Sdim ExplodedNodeSet &Dst) { 404243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 405234353Sdim 406251662Sdim ProgramStateRef State = Pred->getState(); 407251662Sdim const LocationContext *LCtx = Pred->getLocationContext(); 408251662Sdim 409251662Sdim const Expr *Init = CL->getInitializer(); 410251662Sdim SVal V = State->getSVal(CL->getInitializer(), LCtx); 411226586Sdim 412251662Sdim if (isa<CXXConstructExpr>(Init)) { 413251662Sdim // No work needed. Just pass the value up to this expression. 414251662Sdim } else { 415251662Sdim assert(isa<InitListExpr>(Init)); 416251662Sdim Loc CLLoc = State->getLValue(CL, LCtx); 417251662Sdim State = State->bindLoc(CLLoc, V); 418239462Sdim 419251662Sdim // Compound literal expressions are a GNU extension in C++. 420251662Sdim // Unlike in C, where CLs are lvalues, in C++ CLs are prvalues, 421251662Sdim // and like temporary objects created by the functional notation T() 422251662Sdim // CLs are destroyed at the end of the containing full-expression. 423251662Sdim // HOWEVER, an rvalue of array type is not something the analyzer can 424251662Sdim // reason about, since we expect all regions to be wrapped in Locs. 425251662Sdim // So we treat array CLs as lvalues as well, knowing that they will decay 426251662Sdim // to pointers as soon as they are used. 427251662Sdim if (CL->isGLValue() || CL->getType()->isArrayType()) 428251662Sdim V = CLLoc; 429251662Sdim } 430251662Sdim 431251662Sdim B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V)); 432226586Sdim} 433226586Sdim 434226586Sdimvoid ExprEngine::VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 435226586Sdim ExplodedNodeSet &Dst) { 436226586Sdim // Assumption: The CFG has one DeclStmt per Decl. 437249423Sdim const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin()); 438249423Sdim 439249423Sdim if (!VD) { 440234353Sdim //TODO:AZ: remove explicit insertion after refactoring is done. 441234353Sdim Dst.insert(Pred); 442226586Sdim return; 443234353Sdim } 444226586Sdim 445226586Sdim // FIXME: all pre/post visits should eventually be handled by ::Visit(). 446226586Sdim ExplodedNodeSet dstPreVisit; 447226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this); 448226586Sdim 449243830Sdim StmtNodeBuilder B(dstPreVisit, Dst, *currBldrCtx); 450226586Sdim for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 451226586Sdim I!=E; ++I) { 452226586Sdim ExplodedNode *N = *I; 453234353Sdim ProgramStateRef state = N->getState(); 454249423Sdim const LocationContext *LC = N->getLocationContext(); 455249423Sdim 456226586Sdim // Decls without InitExpr are not initialized explicitly. 457226586Sdim if (const Expr *InitEx = VD->getInit()) { 458249423Sdim 459249423Sdim // Note in the state that the initialization has occurred. 460249423Sdim ExplodedNode *UpdatedN = N; 461239462Sdim SVal InitVal = state->getSVal(InitEx, LC); 462234353Sdim 463249423Sdim if (isa<CXXConstructExpr>(InitEx->IgnoreImplicit())) { 464239462Sdim // We constructed the object directly in the variable. 465239462Sdim // No need to bind anything. 466249423Sdim B.generateNode(DS, UpdatedN, state); 467239462Sdim } else { 468239462Sdim // We bound the temp obj region to the CXXConstructExpr. Now recover 469239462Sdim // the lazy compound value when the variable is not a reference. 470249423Sdim if (AMgr.getLangOpts().CPlusPlus && VD->getType()->isRecordType() && 471249423Sdim !VD->getType()->isReferenceType()) { 472249423Sdim if (Optional<loc::MemRegionVal> M = 473249423Sdim InitVal.getAs<loc::MemRegionVal>()) { 474249423Sdim InitVal = state->getSVal(M->getRegion()); 475249423Sdim assert(InitVal.getAs<nonloc::LazyCompoundVal>()); 476249423Sdim } 477239462Sdim } 478239462Sdim 479239462Sdim // Recover some path-sensitivity if a scalar value evaluated to 480239462Sdim // UnknownVal. 481239462Sdim if (InitVal.isUnknown()) { 482239462Sdim QualType Ty = InitEx->getType(); 483239462Sdim if (InitEx->isGLValue()) { 484239462Sdim Ty = getContext().getPointerType(Ty); 485239462Sdim } 486239462Sdim 487243830Sdim InitVal = svalBuilder.conjureSymbolVal(0, InitEx, LC, Ty, 488243830Sdim currBldrCtx->blockCount()); 489239462Sdim } 490249423Sdim 491249423Sdim 492249423Sdim B.takeNodes(UpdatedN); 493239462Sdim ExplodedNodeSet Dst2; 494249423Sdim evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true); 495239462Sdim B.addNodes(Dst2); 496226586Sdim } 497226586Sdim } 498226586Sdim else { 499243830Sdim B.generateNode(DS, N, state); 500226586Sdim } 501226586Sdim } 502226586Sdim} 503226586Sdim 504226586Sdimvoid ExprEngine::VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 505226586Sdim ExplodedNodeSet &Dst) { 506226586Sdim assert(B->getOpcode() == BO_LAnd || 507226586Sdim B->getOpcode() == BO_LOr); 508234353Sdim 509243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 510234353Sdim ProgramStateRef state = Pred->getState(); 511239462Sdim 512239462Sdim ExplodedNode *N = Pred; 513249423Sdim while (!N->getLocation().getAs<BlockEntrance>()) { 514239462Sdim ProgramPoint P = N->getLocation(); 515249423Sdim assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>()); 516239462Sdim (void) P; 517239462Sdim assert(N->pred_size() == 1); 518239462Sdim N = *N->pred_begin(); 519226586Sdim } 520239462Sdim assert(N->pred_size() == 1); 521239462Sdim N = *N->pred_begin(); 522249423Sdim BlockEdge BE = N->getLocation().castAs<BlockEdge>(); 523239462Sdim SVal X; 524239462Sdim 525239462Sdim // Determine the value of the expression by introspecting how we 526239462Sdim // got this location in the CFG. This requires looking at the previous 527239462Sdim // block we were in and what kind of control-flow transfer was involved. 528239462Sdim const CFGBlock *SrcBlock = BE.getSrc(); 529239462Sdim // The only terminator (if there is one) that makes sense is a logical op. 530239462Sdim CFGTerminator T = SrcBlock->getTerminator(); 531239462Sdim if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) { 532239462Sdim (void) Term; 533239462Sdim assert(Term->isLogicalOp()); 534239462Sdim assert(SrcBlock->succ_size() == 2); 535239462Sdim // Did we take the true or false branch? 536239462Sdim unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 1 : 0; 537239462Sdim X = svalBuilder.makeIntVal(constant, B->getType()); 538239462Sdim } 539226586Sdim else { 540239462Sdim // If there is no terminator, by construction the last statement 541239462Sdim // in SrcBlock is the value of the enclosing expression. 542243830Sdim // However, we still need to constrain that value to be 0 or 1. 543239462Sdim assert(!SrcBlock->empty()); 544249423Sdim CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>(); 545243830Sdim const Expr *RHS = cast<Expr>(Elem.getStmt()); 546243830Sdim SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext()); 547243830Sdim 548249423Sdim if (RHSVal.isUndef()) { 549249423Sdim X = RHSVal; 550249423Sdim } else { 551249423Sdim DefinedOrUnknownSVal DefinedRHS = RHSVal.castAs<DefinedOrUnknownSVal>(); 552249423Sdim ProgramStateRef StTrue, StFalse; 553249423Sdim llvm::tie(StTrue, StFalse) = N->getState()->assume(DefinedRHS); 554249423Sdim if (StTrue) { 555249423Sdim if (StFalse) { 556249423Sdim // We can't constrain the value to 0 or 1. 557249423Sdim // The best we can do is a cast. 558249423Sdim X = getSValBuilder().evalCast(RHSVal, B->getType(), RHS->getType()); 559249423Sdim } else { 560249423Sdim // The value is known to be true. 561249423Sdim X = getSValBuilder().makeIntVal(1, B->getType()); 562249423Sdim } 563243830Sdim } else { 564249423Sdim // The value is known to be false. 565249423Sdim assert(StFalse && "Infeasible path!"); 566249423Sdim X = getSValBuilder().makeIntVal(0, B->getType()); 567243830Sdim } 568243830Sdim } 569226586Sdim } 570239462Sdim Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X)); 571226586Sdim} 572226586Sdim 573226586Sdimvoid ExprEngine::VisitInitListExpr(const InitListExpr *IE, 574226586Sdim ExplodedNode *Pred, 575226586Sdim ExplodedNodeSet &Dst) { 576243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 577226586Sdim 578234353Sdim ProgramStateRef state = Pred->getState(); 579234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 580226586Sdim QualType T = getContext().getCanonicalType(IE->getType()); 581226586Sdim unsigned NumInitElements = IE->getNumInits(); 582226586Sdim 583243830Sdim if (T->isArrayType() || T->isRecordType() || T->isVectorType() || 584243830Sdim T->isAnyComplexType()) { 585226586Sdim llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList(); 586226586Sdim 587226586Sdim // Handle base case where the initializer has no elements. 588226586Sdim // e.g: static int* myArray[] = {}; 589226586Sdim if (NumInitElements == 0) { 590226586Sdim SVal V = svalBuilder.makeCompoundVal(T, vals); 591234353Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 592226586Sdim return; 593226586Sdim } 594226586Sdim 595226586Sdim for (InitListExpr::const_reverse_iterator it = IE->rbegin(), 596226586Sdim ei = IE->rend(); it != ei; ++it) { 597249423Sdim SVal V = state->getSVal(cast<Expr>(*it), LCtx); 598249423Sdim if (dyn_cast_or_null<CXXTempObjectRegion>(V.getAsRegion())) 599249423Sdim V = UnknownVal(); 600249423Sdim vals = getBasicVals().consVals(V, vals); 601226586Sdim } 602226586Sdim 603234353Sdim B.generateNode(IE, Pred, 604234353Sdim state->BindExpr(IE, LCtx, 605234353Sdim svalBuilder.makeCompoundVal(T, vals))); 606226586Sdim return; 607226586Sdim } 608239462Sdim 609239462Sdim // Handle scalars: int{5} and int{}. 610239462Sdim assert(NumInitElements <= 1); 611239462Sdim 612239462Sdim SVal V; 613239462Sdim if (NumInitElements == 0) 614239462Sdim V = getSValBuilder().makeZeroVal(T); 615239462Sdim else 616239462Sdim V = state->getSVal(IE->getInit(0), LCtx); 617239462Sdim 618239462Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 619226586Sdim} 620226586Sdim 621226586Sdimvoid ExprEngine::VisitGuardedExpr(const Expr *Ex, 622226586Sdim const Expr *L, 623226586Sdim const Expr *R, 624226586Sdim ExplodedNode *Pred, 625226586Sdim ExplodedNodeSet &Dst) { 626251662Sdim assert(L && R); 627251662Sdim 628243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 629234353Sdim ProgramStateRef state = Pred->getState(); 630234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 631239462Sdim const CFGBlock *SrcBlock = 0; 632239462Sdim 633251662Sdim // Find the predecessor block. 634251662Sdim ProgramStateRef SrcState = state; 635239462Sdim for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) { 636239462Sdim ProgramPoint PP = N->getLocation(); 637249423Sdim if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) { 638239462Sdim assert(N->pred_size() == 1); 639239462Sdim continue; 640239462Sdim } 641249423Sdim SrcBlock = PP.castAs<BlockEdge>().getSrc(); 642251662Sdim SrcState = N->getState(); 643239462Sdim break; 644239462Sdim } 645239462Sdim 646249423Sdim assert(SrcBlock && "missing function entry"); 647249423Sdim 648239462Sdim // Find the last expression in the predecessor block. That is the 649239462Sdim // expression that is used for the value of the ternary expression. 650239462Sdim bool hasValue = false; 651239462Sdim SVal V; 652239462Sdim 653239462Sdim for (CFGBlock::const_reverse_iterator I = SrcBlock->rbegin(), 654239462Sdim E = SrcBlock->rend(); I != E; ++I) { 655239462Sdim CFGElement CE = *I; 656249423Sdim if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) { 657239462Sdim const Expr *ValEx = cast<Expr>(CS->getStmt()); 658251662Sdim ValEx = ValEx->IgnoreParens(); 659251662Sdim 660251662Sdim // For GNU extension '?:' operator, the left hand side will be an 661251662Sdim // OpaqueValueExpr, so get the underlying expression. 662251662Sdim if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L)) 663251662Sdim L = OpaqueEx->getSourceExpr(); 664251662Sdim 665251662Sdim // If the last expression in the predecessor block matches true or false 666251662Sdim // subexpression, get its the value. 667251662Sdim if (ValEx == L->IgnoreParens() || ValEx == R->IgnoreParens()) { 668251662Sdim hasValue = true; 669251662Sdim V = SrcState->getSVal(ValEx, LCtx); 670251662Sdim } 671239462Sdim break; 672239462Sdim } 673239462Sdim } 674239462Sdim 675251662Sdim if (!hasValue) 676251662Sdim V = svalBuilder.conjureSymbolVal(0, Ex, LCtx, currBldrCtx->blockCount()); 677239462Sdim 678239462Sdim // Generate a new node with the binding from the appropriate path. 679239462Sdim B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true)); 680226586Sdim} 681226586Sdim 682226586Sdimvoid ExprEngine:: 683226586SdimVisitOffsetOfExpr(const OffsetOfExpr *OOE, 684226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 685243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 686234353Sdim APSInt IV; 687234353Sdim if (OOE->EvaluateAsInt(IV, getContext())) { 688226586Sdim assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType())); 689251662Sdim assert(OOE->getType()->isBuiltinType()); 690251662Sdim assert(OOE->getType()->getAs<BuiltinType>()->isInteger()); 691251662Sdim assert(IV.isSigned() == OOE->getType()->isSignedIntegerType()); 692226586Sdim SVal X = svalBuilder.makeIntVal(IV); 693234353Sdim B.generateNode(OOE, Pred, 694234353Sdim Pred->getState()->BindExpr(OOE, Pred->getLocationContext(), 695234353Sdim X)); 696226586Sdim } 697226586Sdim // FIXME: Handle the case where __builtin_offsetof is not a constant. 698226586Sdim} 699226586Sdim 700226586Sdim 701226586Sdimvoid ExprEngine:: 702226586SdimVisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 703226586Sdim ExplodedNode *Pred, 704226586Sdim ExplodedNodeSet &Dst) { 705243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 706226586Sdim 707226586Sdim QualType T = Ex->getTypeOfArgument(); 708226586Sdim 709226586Sdim if (Ex->getKind() == UETT_SizeOf) { 710226586Sdim if (!T->isIncompleteType() && !T->isConstantSizeType()) { 711226586Sdim assert(T->isVariableArrayType() && "Unknown non-constant-sized type."); 712226586Sdim 713226586Sdim // FIXME: Add support for VLA type arguments and VLA expressions. 714226586Sdim // When that happens, we should probably refactor VLASizeChecker's code. 715226586Sdim return; 716226586Sdim } 717226586Sdim else if (T->getAs<ObjCObjectType>()) { 718226586Sdim // Some code tries to take the sizeof an ObjCObjectType, relying that 719226586Sdim // the compiler has laid out its representation. Just report Unknown 720226586Sdim // for these. 721226586Sdim return; 722226586Sdim } 723226586Sdim } 724226586Sdim 725234353Sdim APSInt Value = Ex->EvaluateKnownConstInt(getContext()); 726234353Sdim CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue()); 727226586Sdim 728234353Sdim ProgramStateRef state = Pred->getState(); 729234353Sdim state = state->BindExpr(Ex, Pred->getLocationContext(), 730234353Sdim svalBuilder.makeIntVal(amt.getQuantity(), 731226586Sdim Ex->getType())); 732234353Sdim Bldr.generateNode(Ex, Pred, state); 733226586Sdim} 734226586Sdim 735226586Sdimvoid ExprEngine::VisitUnaryOperator(const UnaryOperator* U, 736226586Sdim ExplodedNode *Pred, 737234353Sdim ExplodedNodeSet &Dst) { 738243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 739226586Sdim switch (U->getOpcode()) { 740234353Sdim default: { 741234353Sdim Bldr.takeNodes(Pred); 742234353Sdim ExplodedNodeSet Tmp; 743234353Sdim VisitIncrementDecrementOperator(U, Pred, Tmp); 744234353Sdim Bldr.addNodes(Tmp); 745234353Sdim } 746226586Sdim break; 747226586Sdim case UO_Real: { 748226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 749226586Sdim 750234353Sdim // FIXME: We don't have complex SValues yet. 751234353Sdim if (Ex->getType()->isAnyComplexType()) { 752234353Sdim // Just report "Unknown." 753234353Sdim break; 754234353Sdim } 755226586Sdim 756234353Sdim // For all other types, UO_Real is an identity operation. 757234353Sdim assert (U->getType() == Ex->getType()); 758234353Sdim ProgramStateRef state = Pred->getState(); 759234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 760234353Sdim Bldr.generateNode(U, Pred, state->BindExpr(U, LCtx, 761234353Sdim state->getSVal(Ex, LCtx))); 762234353Sdim break; 763226586Sdim } 764226586Sdim 765234353Sdim case UO_Imag: { 766226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 767234353Sdim // FIXME: We don't have complex SValues yet. 768234353Sdim if (Ex->getType()->isAnyComplexType()) { 769234353Sdim // Just report "Unknown." 770234353Sdim break; 771226586Sdim } 772234353Sdim // For all other types, UO_Imag returns 0. 773234353Sdim ProgramStateRef state = Pred->getState(); 774234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 775234353Sdim SVal X = svalBuilder.makeZeroVal(Ex->getType()); 776234353Sdim Bldr.generateNode(U, Pred, state->BindExpr(U, LCtx, X)); 777234353Sdim break; 778226586Sdim } 779226586Sdim 780226586Sdim case UO_Plus: 781239462Sdim assert(!U->isGLValue()); 782226586Sdim // FALL-THROUGH. 783226586Sdim case UO_Deref: 784226586Sdim case UO_AddrOf: 785226586Sdim case UO_Extension: { 786234353Sdim // FIXME: We can probably just have some magic in Environment::getSVal() 787234353Sdim // that propagates values, instead of creating a new node here. 788234353Sdim // 789226586Sdim // Unary "+" is a no-op, similar to a parentheses. We still have places 790226586Sdim // where it may be a block-level expression, so we need to 791226586Sdim // generate an extra node that just propagates the value of the 792234353Sdim // subexpression. 793226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 794234353Sdim ProgramStateRef state = Pred->getState(); 795234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 796234353Sdim Bldr.generateNode(U, Pred, state->BindExpr(U, LCtx, 797234353Sdim state->getSVal(Ex, LCtx))); 798234353Sdim break; 799226586Sdim } 800226586Sdim 801226586Sdim case UO_LNot: 802226586Sdim case UO_Minus: 803226586Sdim case UO_Not: { 804239462Sdim assert (!U->isGLValue()); 805226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 806234353Sdim ProgramStateRef state = Pred->getState(); 807234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 808226586Sdim 809234353Sdim // Get the value of the subexpression. 810234353Sdim SVal V = state->getSVal(Ex, LCtx); 811226586Sdim 812234353Sdim if (V.isUnknownOrUndef()) { 813234353Sdim Bldr.generateNode(U, Pred, state->BindExpr(U, LCtx, V)); 814234353Sdim break; 815234353Sdim } 816226586Sdim 817234353Sdim switch (U->getOpcode()) { 818234353Sdim default: 819234353Sdim llvm_unreachable("Invalid Opcode."); 820234353Sdim case UO_Not: 821234353Sdim // FIXME: Do we need to handle promotions? 822249423Sdim state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>())); 823234353Sdim break; 824234353Sdim case UO_Minus: 825234353Sdim // FIXME: Do we need to handle promotions? 826249423Sdim state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>())); 827234353Sdim break; 828234353Sdim case UO_LNot: 829234353Sdim // C99 6.5.3.3: "The expression !E is equivalent to (0==E)." 830234353Sdim // 831234353Sdim // Note: technically we do "E == 0", but this is the same in the 832234353Sdim // transfer functions as "0 == E". 833234353Sdim SVal Result; 834249423Sdim if (Optional<Loc> LV = V.getAs<Loc>()) { 835234353Sdim Loc X = svalBuilder.makeNull(); 836249423Sdim Result = evalBinOp(state, BO_EQ, *LV, X, U->getType()); 837234353Sdim } 838249423Sdim else if (Ex->getType()->isFloatingType()) { 839249423Sdim // FIXME: handle floating point types. 840249423Sdim Result = UnknownVal(); 841249423Sdim } else { 842234353Sdim nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType())); 843249423Sdim Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X, 844234353Sdim U->getType()); 845234353Sdim } 846234353Sdim 847234353Sdim state = state->BindExpr(U, LCtx, Result); 848234353Sdim break; 849226586Sdim } 850234353Sdim Bldr.generateNode(U, Pred, state); 851234353Sdim break; 852226586Sdim } 853226586Sdim } 854234353Sdim 855234353Sdim} 856234353Sdim 857234353Sdimvoid ExprEngine::VisitIncrementDecrementOperator(const UnaryOperator* U, 858234353Sdim ExplodedNode *Pred, 859234353Sdim ExplodedNodeSet &Dst) { 860226586Sdim // Handle ++ and -- (both pre- and post-increment). 861226586Sdim assert (U->isIncrementDecrementOp()); 862226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 863226586Sdim 864234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 865234353Sdim ProgramStateRef state = Pred->getState(); 866234353Sdim SVal loc = state->getSVal(Ex, LCtx); 867234353Sdim 868234353Sdim // Perform a load. 869234353Sdim ExplodedNodeSet Tmp; 870234353Sdim evalLoad(Tmp, U, Ex, Pred, state, loc); 871234353Sdim 872234353Sdim ExplodedNodeSet Dst2; 873243830Sdim StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx); 874234353Sdim for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;++I) { 875226586Sdim 876234353Sdim state = (*I)->getState(); 877234353Sdim assert(LCtx == (*I)->getLocationContext()); 878234353Sdim SVal V2_untested = state->getSVal(Ex, LCtx); 879226586Sdim 880234353Sdim // Propagate unknown and undefined values. 881234353Sdim if (V2_untested.isUnknownOrUndef()) { 882234353Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V2_untested)); 883234353Sdim continue; 884234353Sdim } 885249423Sdim DefinedSVal V2 = V2_untested.castAs<DefinedSVal>(); 886226586Sdim 887234353Sdim // Handle all other values. 888234353Sdim BinaryOperator::Opcode Op = U->isIncrementOp() ? BO_Add : BO_Sub; 889234353Sdim 890234353Sdim // If the UnaryOperator has non-location type, use its type to create the 891234353Sdim // constant value. If the UnaryOperator has location type, create the 892234353Sdim // constant with int type and pointer width. 893234353Sdim SVal RHS; 894234353Sdim 895234353Sdim if (U->getType()->isAnyPointerType()) 896234353Sdim RHS = svalBuilder.makeArrayIndex(1); 897243830Sdim else if (U->getType()->isIntegralOrEnumerationType()) 898243830Sdim RHS = svalBuilder.makeIntVal(1, U->getType()); 899234353Sdim else 900243830Sdim RHS = UnknownVal(); 901234353Sdim 902234353Sdim SVal Result = evalBinOp(state, Op, V2, RHS, U->getType()); 903234353Sdim 904234353Sdim // Conjure a new symbol if necessary to recover precision. 905234353Sdim if (Result.isUnknown()){ 906234353Sdim DefinedOrUnknownSVal SymVal = 907243830Sdim svalBuilder.conjureSymbolVal(0, Ex, LCtx, currBldrCtx->blockCount()); 908234353Sdim Result = SymVal; 909226586Sdim 910234353Sdim // If the value is a location, ++/-- should always preserve 911234353Sdim // non-nullness. Check if the original value was non-null, and if so 912234353Sdim // propagate that constraint. 913234353Sdim if (Loc::isLocType(U->getType())) { 914234353Sdim DefinedOrUnknownSVal Constraint = 915234353Sdim svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType())); 916226586Sdim 917234353Sdim if (!state->assume(Constraint, true)) { 918234353Sdim // It isn't feasible for the original value to be null. 919234353Sdim // Propagate this constraint. 920234353Sdim Constraint = svalBuilder.evalEQ(state, SymVal, 921234353Sdim svalBuilder.makeZeroVal(U->getType())); 922226586Sdim 923234353Sdim 924234353Sdim state = state->assume(Constraint, false); 925234353Sdim assert(state); 926226586Sdim } 927226586Sdim } 928226586Sdim } 929234353Sdim 930234353Sdim // Since the lvalue-to-rvalue conversion is explicit in the AST, 931234353Sdim // we bind an l-value if the operator is prefix and an lvalue (in C++). 932239462Sdim if (U->isGLValue()) 933234353Sdim state = state->BindExpr(U, LCtx, loc); 934234353Sdim else 935234353Sdim state = state->BindExpr(U, LCtx, U->isPostfix() ? V2 : Result); 936234353Sdim 937234353Sdim // Perform the store. 938234353Sdim Bldr.takeNodes(*I); 939234353Sdim ExplodedNodeSet Dst3; 940234353Sdim evalStore(Dst3, U, U, *I, state, loc, Result); 941234353Sdim Bldr.addNodes(Dst3); 942226586Sdim } 943234353Sdim Dst.insert(Dst2); 944226586Sdim} 945