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, 187263508Sdim Pred->getLocationContext(), 188263508Sdim currBldrCtx->blockCount()); 189226586Sdim 190239462Sdim ProgramStateRef State = Pred->getState(); 191239462Sdim 192239462Sdim // If we created a new MemRegion for the block, we should explicitly bind 193239462Sdim // the captured variables. 194239462Sdim if (const BlockDataRegion *BDR = 195239462Sdim dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) { 196239462Sdim 197239462Sdim BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 198239462Sdim E = BDR->referenced_vars_end(); 199239462Sdim 200239462Sdim for (; I != E; ++I) { 201239462Sdim const MemRegion *capturedR = I.getCapturedRegion(); 202239462Sdim const MemRegion *originalR = I.getOriginalRegion(); 203239462Sdim if (capturedR != originalR) { 204239462Sdim SVal originalV = State->getSVal(loc::MemRegionVal(originalR)); 205239462Sdim State = State->bindLoc(loc::MemRegionVal(capturedR), originalV); 206239462Sdim } 207239462Sdim } 208239462Sdim } 209239462Sdim 210226586Sdim ExplodedNodeSet Tmp; 211243830Sdim StmtNodeBuilder Bldr(Pred, Tmp, *currBldrCtx); 212234353Sdim Bldr.generateNode(BE, Pred, 213239462Sdim State->BindExpr(BE, Pred->getLocationContext(), V), 214243830Sdim 0, ProgramPoint::PostLValueKind); 215226586Sdim 216226586Sdim // FIXME: Move all post/pre visits to ::Visit(). 217226586Sdim getCheckerManager().runCheckersForPostStmt(Dst, Tmp, BE, *this); 218226586Sdim} 219226586Sdim 220226586Sdimvoid ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex, 221226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 222226586Sdim 223226586Sdim ExplodedNodeSet dstPreStmt; 224226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreStmt, Pred, CastE, *this); 225226586Sdim 226234353Sdim if (CastE->getCastKind() == CK_LValueToRValue) { 227226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 228226586Sdim I!=E; ++I) { 229226586Sdim ExplodedNode *subExprNode = *I; 230234353Sdim ProgramStateRef state = subExprNode->getState(); 231234353Sdim const LocationContext *LCtx = subExprNode->getLocationContext(); 232234353Sdim evalLoad(Dst, CastE, CastE, subExprNode, state, state->getSVal(Ex, LCtx)); 233226586Sdim } 234226586Sdim return; 235226586Sdim } 236226586Sdim 237226586Sdim // All other casts. 238226586Sdim QualType T = CastE->getType(); 239226586Sdim QualType ExTy = Ex->getType(); 240226586Sdim 241226586Sdim if (const ExplicitCastExpr *ExCast=dyn_cast_or_null<ExplicitCastExpr>(CastE)) 242226586Sdim T = ExCast->getTypeAsWritten(); 243226586Sdim 244243830Sdim StmtNodeBuilder Bldr(dstPreStmt, Dst, *currBldrCtx); 245226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 246226586Sdim I != E; ++I) { 247226586Sdim 248226586Sdim Pred = *I; 249243830Sdim ProgramStateRef state = Pred->getState(); 250243830Sdim const LocationContext *LCtx = Pred->getLocationContext(); 251243830Sdim 252226586Sdim switch (CastE->getCastKind()) { 253226586Sdim case CK_LValueToRValue: 254226586Sdim llvm_unreachable("LValueToRValue casts handled earlier."); 255226586Sdim case CK_ToVoid: 256226586Sdim continue; 257226586Sdim // The analyzer doesn't do anything special with these casts, 258226586Sdim // since it understands retain/release semantics already. 259226586Sdim case CK_ARCProduceObject: 260226586Sdim case CK_ARCConsumeObject: 261226586Sdim case CK_ARCReclaimReturnedObject: 262226586Sdim case CK_ARCExtendBlockObject: // Fall-through. 263234353Sdim case CK_CopyAndAutoreleaseBlockObject: 264234353Sdim // The analyser can ignore atomic casts for now, although some future 265234353Sdim // checkers may want to make certain that you're not modifying the same 266234353Sdim // value through atomic and nonatomic pointers. 267234353Sdim case CK_AtomicToNonAtomic: 268234353Sdim case CK_NonAtomicToAtomic: 269226586Sdim // True no-ops. 270226586Sdim case CK_NoOp: 271243830Sdim case CK_ConstructorConversion: 272243830Sdim case CK_UserDefinedConversion: 273243830Sdim case CK_FunctionToPointerDecay: 274243830Sdim case CK_BuiltinFnToFnPtr: { 275226586Sdim // Copy the SVal of Ex to CastE. 276234353Sdim ProgramStateRef state = Pred->getState(); 277234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 278234353Sdim SVal V = state->getSVal(Ex, LCtx); 279234353Sdim state = state->BindExpr(CastE, LCtx, V); 280234353Sdim Bldr.generateNode(CastE, Pred, state); 281226586Sdim continue; 282226586Sdim } 283243830Sdim case CK_MemberPointerToBoolean: 284243830Sdim // FIXME: For now, member pointers are represented by void *. 285243830Sdim // FALLTHROUGH 286226586Sdim case CK_Dependent: 287226586Sdim case CK_ArrayToPointerDecay: 288226586Sdim case CK_BitCast: 289226586Sdim case CK_IntegralCast: 290226586Sdim case CK_NullToPointer: 291226586Sdim case CK_IntegralToPointer: 292226586Sdim case CK_PointerToIntegral: 293226586Sdim case CK_PointerToBoolean: 294226586Sdim case CK_IntegralToBoolean: 295226586Sdim case CK_IntegralToFloating: 296226586Sdim case CK_FloatingToIntegral: 297226586Sdim case CK_FloatingToBoolean: 298226586Sdim case CK_FloatingCast: 299226586Sdim case CK_FloatingRealToComplex: 300226586Sdim case CK_FloatingComplexToReal: 301226586Sdim case CK_FloatingComplexToBoolean: 302226586Sdim case CK_FloatingComplexCast: 303226586Sdim case CK_FloatingComplexToIntegralComplex: 304226586Sdim case CK_IntegralRealToComplex: 305226586Sdim case CK_IntegralComplexToReal: 306226586Sdim case CK_IntegralComplexToBoolean: 307226586Sdim case CK_IntegralComplexCast: 308226586Sdim case CK_IntegralComplexToFloatingComplex: 309226586Sdim case CK_CPointerToObjCPointerCast: 310226586Sdim case CK_BlockPointerToObjCPointerCast: 311226586Sdim case CK_AnyPointerToBlockPointerCast: 312249423Sdim case CK_ObjCObjectLValueCast: 313263508Sdim case CK_ZeroToOCLEvent: 314263508Sdim case CK_LValueBitCast: { 315226586Sdim // Delegate to SValBuilder to process. 316234353Sdim SVal V = state->getSVal(Ex, LCtx); 317226586Sdim V = svalBuilder.evalCast(V, T, ExTy); 318234353Sdim state = state->BindExpr(CastE, LCtx, V); 319234353Sdim Bldr.generateNode(CastE, Pred, state); 320226586Sdim continue; 321226586Sdim } 322226586Sdim case CK_DerivedToBase: 323226586Sdim case CK_UncheckedDerivedToBase: { 324226586Sdim // For DerivedToBase cast, delegate to the store manager. 325234353Sdim SVal val = state->getSVal(Ex, LCtx); 326239462Sdim val = getStoreManager().evalDerivedToBase(val, CastE); 327234353Sdim state = state->BindExpr(CastE, LCtx, val); 328234353Sdim Bldr.generateNode(CastE, Pred, state); 329226586Sdim continue; 330226586Sdim } 331234353Sdim // Handle C++ dyn_cast. 332234353Sdim case CK_Dynamic: { 333234353Sdim SVal val = state->getSVal(Ex, LCtx); 334234353Sdim 335234353Sdim // Compute the type of the result. 336234353Sdim QualType resultType = CastE->getType(); 337239462Sdim if (CastE->isGLValue()) 338234353Sdim resultType = getContext().getPointerType(resultType); 339234353Sdim 340234353Sdim bool Failed = false; 341234353Sdim 342234353Sdim // Check if the value being cast evaluates to 0. 343234353Sdim if (val.isZeroConstant()) 344234353Sdim Failed = true; 345234353Sdim // Else, evaluate the cast. 346234353Sdim else 347234353Sdim val = getStoreManager().evalDynamicCast(val, T, Failed); 348234353Sdim 349234353Sdim if (Failed) { 350234353Sdim if (T->isReferenceType()) { 351234353Sdim // A bad_cast exception is thrown if input value is a reference. 352234353Sdim // Currently, we model this, by generating a sink. 353243830Sdim Bldr.generateSink(CastE, Pred, state); 354234353Sdim continue; 355234353Sdim } else { 356234353Sdim // If the cast fails on a pointer, bind to 0. 357234353Sdim state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull()); 358234353Sdim } 359234353Sdim } else { 360234353Sdim // If we don't know if the cast succeeded, conjure a new symbol. 361234353Sdim if (val.isUnknown()) { 362243830Sdim DefinedOrUnknownSVal NewSym = 363243830Sdim svalBuilder.conjureSymbolVal(0, CastE, LCtx, resultType, 364243830Sdim currBldrCtx->blockCount()); 365234353Sdim state = state->BindExpr(CastE, LCtx, NewSym); 366234353Sdim } else 367234353Sdim // Else, bind to the derived region value. 368234353Sdim state = state->BindExpr(CastE, LCtx, val); 369234353Sdim } 370234353Sdim Bldr.generateNode(CastE, Pred, state); 371234353Sdim continue; 372234353Sdim } 373243830Sdim case CK_NullToMemberPointer: { 374243830Sdim // FIXME: For now, member pointers are represented by void *. 375263508Sdim SVal V = svalBuilder.makeNull(); 376243830Sdim state = state->BindExpr(CastE, LCtx, V); 377243830Sdim Bldr.generateNode(CastE, Pred, state); 378243830Sdim continue; 379243830Sdim } 380234353Sdim // Various C++ casts that are not handled yet. 381226586Sdim case CK_ToUnion: 382226586Sdim case CK_BaseToDerived: 383226586Sdim case CK_BaseToDerivedMemberPointer: 384226586Sdim case CK_DerivedToBaseMemberPointer: 385234353Sdim case CK_ReinterpretMemberPointer: 386263508Sdim case CK_VectorSplat: { 387226586Sdim // Recover some path-sensitivty by conjuring a new value. 388226586Sdim QualType resultType = CastE->getType(); 389239462Sdim if (CastE->isGLValue()) 390226586Sdim resultType = getContext().getPointerType(resultType); 391243830Sdim SVal result = svalBuilder.conjureSymbolVal(0, CastE, LCtx, 392243830Sdim resultType, 393243830Sdim currBldrCtx->blockCount()); 394243830Sdim state = state->BindExpr(CastE, LCtx, result); 395234353Sdim Bldr.generateNode(CastE, Pred, state); 396226586Sdim continue; 397226586Sdim } 398226586Sdim } 399226586Sdim } 400226586Sdim} 401226586Sdim 402226586Sdimvoid ExprEngine::VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 403226586Sdim ExplodedNode *Pred, 404226586Sdim ExplodedNodeSet &Dst) { 405243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 406234353Sdim 407251662Sdim ProgramStateRef State = Pred->getState(); 408251662Sdim const LocationContext *LCtx = Pred->getLocationContext(); 409251662Sdim 410251662Sdim const Expr *Init = CL->getInitializer(); 411251662Sdim SVal V = State->getSVal(CL->getInitializer(), LCtx); 412226586Sdim 413251662Sdim if (isa<CXXConstructExpr>(Init)) { 414251662Sdim // No work needed. Just pass the value up to this expression. 415251662Sdim } else { 416251662Sdim assert(isa<InitListExpr>(Init)); 417251662Sdim Loc CLLoc = State->getLValue(CL, LCtx); 418251662Sdim State = State->bindLoc(CLLoc, V); 419239462Sdim 420251662Sdim // Compound literal expressions are a GNU extension in C++. 421251662Sdim // Unlike in C, where CLs are lvalues, in C++ CLs are prvalues, 422251662Sdim // and like temporary objects created by the functional notation T() 423251662Sdim // CLs are destroyed at the end of the containing full-expression. 424251662Sdim // HOWEVER, an rvalue of array type is not something the analyzer can 425251662Sdim // reason about, since we expect all regions to be wrapped in Locs. 426251662Sdim // So we treat array CLs as lvalues as well, knowing that they will decay 427251662Sdim // to pointers as soon as they are used. 428251662Sdim if (CL->isGLValue() || CL->getType()->isArrayType()) 429251662Sdim V = CLLoc; 430251662Sdim } 431251662Sdim 432251662Sdim B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V)); 433226586Sdim} 434226586Sdim 435226586Sdimvoid ExprEngine::VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 436226586Sdim ExplodedNodeSet &Dst) { 437226586Sdim // Assumption: The CFG has one DeclStmt per Decl. 438249423Sdim const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin()); 439249423Sdim 440249423Sdim if (!VD) { 441234353Sdim //TODO:AZ: remove explicit insertion after refactoring is done. 442234353Sdim Dst.insert(Pred); 443226586Sdim return; 444234353Sdim } 445226586Sdim 446226586Sdim // FIXME: all pre/post visits should eventually be handled by ::Visit(). 447226586Sdim ExplodedNodeSet dstPreVisit; 448226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this); 449226586Sdim 450263508Sdim ExplodedNodeSet dstEvaluated; 451263508Sdim StmtNodeBuilder B(dstPreVisit, dstEvaluated, *currBldrCtx); 452226586Sdim for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 453226586Sdim I!=E; ++I) { 454226586Sdim ExplodedNode *N = *I; 455234353Sdim ProgramStateRef state = N->getState(); 456249423Sdim const LocationContext *LC = N->getLocationContext(); 457249423Sdim 458226586Sdim // Decls without InitExpr are not initialized explicitly. 459226586Sdim if (const Expr *InitEx = VD->getInit()) { 460249423Sdim 461249423Sdim // Note in the state that the initialization has occurred. 462249423Sdim ExplodedNode *UpdatedN = N; 463239462Sdim SVal InitVal = state->getSVal(InitEx, LC); 464234353Sdim 465249423Sdim if (isa<CXXConstructExpr>(InitEx->IgnoreImplicit())) { 466239462Sdim // We constructed the object directly in the variable. 467239462Sdim // No need to bind anything. 468249423Sdim B.generateNode(DS, UpdatedN, state); 469239462Sdim } else { 470239462Sdim // We bound the temp obj region to the CXXConstructExpr. Now recover 471239462Sdim // the lazy compound value when the variable is not a reference. 472249423Sdim if (AMgr.getLangOpts().CPlusPlus && VD->getType()->isRecordType() && 473249423Sdim !VD->getType()->isReferenceType()) { 474249423Sdim if (Optional<loc::MemRegionVal> M = 475249423Sdim InitVal.getAs<loc::MemRegionVal>()) { 476249423Sdim InitVal = state->getSVal(M->getRegion()); 477249423Sdim assert(InitVal.getAs<nonloc::LazyCompoundVal>()); 478249423Sdim } 479239462Sdim } 480239462Sdim 481239462Sdim // Recover some path-sensitivity if a scalar value evaluated to 482239462Sdim // UnknownVal. 483239462Sdim if (InitVal.isUnknown()) { 484239462Sdim QualType Ty = InitEx->getType(); 485239462Sdim if (InitEx->isGLValue()) { 486239462Sdim Ty = getContext().getPointerType(Ty); 487239462Sdim } 488239462Sdim 489243830Sdim InitVal = svalBuilder.conjureSymbolVal(0, InitEx, LC, Ty, 490243830Sdim currBldrCtx->blockCount()); 491239462Sdim } 492249423Sdim 493249423Sdim 494249423Sdim B.takeNodes(UpdatedN); 495239462Sdim ExplodedNodeSet Dst2; 496249423Sdim evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true); 497239462Sdim B.addNodes(Dst2); 498226586Sdim } 499226586Sdim } 500226586Sdim else { 501243830Sdim B.generateNode(DS, N, state); 502226586Sdim } 503226586Sdim } 504263508Sdim 505263508Sdim getCheckerManager().runCheckersForPostStmt(Dst, B.getResults(), DS, *this); 506226586Sdim} 507226586Sdim 508226586Sdimvoid ExprEngine::VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 509226586Sdim ExplodedNodeSet &Dst) { 510226586Sdim assert(B->getOpcode() == BO_LAnd || 511226586Sdim B->getOpcode() == BO_LOr); 512234353Sdim 513243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 514234353Sdim ProgramStateRef state = Pred->getState(); 515239462Sdim 516239462Sdim ExplodedNode *N = Pred; 517249423Sdim while (!N->getLocation().getAs<BlockEntrance>()) { 518239462Sdim ProgramPoint P = N->getLocation(); 519249423Sdim assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>()); 520239462Sdim (void) P; 521239462Sdim assert(N->pred_size() == 1); 522239462Sdim N = *N->pred_begin(); 523226586Sdim } 524239462Sdim assert(N->pred_size() == 1); 525239462Sdim N = *N->pred_begin(); 526249423Sdim BlockEdge BE = N->getLocation().castAs<BlockEdge>(); 527239462Sdim SVal X; 528239462Sdim 529239462Sdim // Determine the value of the expression by introspecting how we 530239462Sdim // got this location in the CFG. This requires looking at the previous 531239462Sdim // block we were in and what kind of control-flow transfer was involved. 532239462Sdim const CFGBlock *SrcBlock = BE.getSrc(); 533239462Sdim // The only terminator (if there is one) that makes sense is a logical op. 534239462Sdim CFGTerminator T = SrcBlock->getTerminator(); 535239462Sdim if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) { 536239462Sdim (void) Term; 537239462Sdim assert(Term->isLogicalOp()); 538239462Sdim assert(SrcBlock->succ_size() == 2); 539239462Sdim // Did we take the true or false branch? 540239462Sdim unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 1 : 0; 541239462Sdim X = svalBuilder.makeIntVal(constant, B->getType()); 542239462Sdim } 543226586Sdim else { 544239462Sdim // If there is no terminator, by construction the last statement 545239462Sdim // in SrcBlock is the value of the enclosing expression. 546243830Sdim // However, we still need to constrain that value to be 0 or 1. 547239462Sdim assert(!SrcBlock->empty()); 548249423Sdim CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>(); 549243830Sdim const Expr *RHS = cast<Expr>(Elem.getStmt()); 550243830Sdim SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext()); 551243830Sdim 552249423Sdim if (RHSVal.isUndef()) { 553249423Sdim X = RHSVal; 554249423Sdim } else { 555249423Sdim DefinedOrUnknownSVal DefinedRHS = RHSVal.castAs<DefinedOrUnknownSVal>(); 556249423Sdim ProgramStateRef StTrue, StFalse; 557249423Sdim llvm::tie(StTrue, StFalse) = N->getState()->assume(DefinedRHS); 558249423Sdim if (StTrue) { 559249423Sdim if (StFalse) { 560249423Sdim // We can't constrain the value to 0 or 1. 561249423Sdim // The best we can do is a cast. 562249423Sdim X = getSValBuilder().evalCast(RHSVal, B->getType(), RHS->getType()); 563249423Sdim } else { 564249423Sdim // The value is known to be true. 565249423Sdim X = getSValBuilder().makeIntVal(1, B->getType()); 566249423Sdim } 567243830Sdim } else { 568249423Sdim // The value is known to be false. 569249423Sdim assert(StFalse && "Infeasible path!"); 570249423Sdim X = getSValBuilder().makeIntVal(0, B->getType()); 571243830Sdim } 572243830Sdim } 573226586Sdim } 574239462Sdim Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X)); 575226586Sdim} 576226586Sdim 577226586Sdimvoid ExprEngine::VisitInitListExpr(const InitListExpr *IE, 578226586Sdim ExplodedNode *Pred, 579226586Sdim ExplodedNodeSet &Dst) { 580243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 581226586Sdim 582234353Sdim ProgramStateRef state = Pred->getState(); 583234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 584226586Sdim QualType T = getContext().getCanonicalType(IE->getType()); 585226586Sdim unsigned NumInitElements = IE->getNumInits(); 586263508Sdim 587263508Sdim if (!IE->isGLValue() && 588263508Sdim (T->isArrayType() || T->isRecordType() || T->isVectorType() || 589263508Sdim T->isAnyComplexType())) { 590226586Sdim llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList(); 591226586Sdim 592226586Sdim // Handle base case where the initializer has no elements. 593226586Sdim // e.g: static int* myArray[] = {}; 594226586Sdim if (NumInitElements == 0) { 595226586Sdim SVal V = svalBuilder.makeCompoundVal(T, vals); 596234353Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 597226586Sdim return; 598226586Sdim } 599226586Sdim 600226586Sdim for (InitListExpr::const_reverse_iterator it = IE->rbegin(), 601226586Sdim ei = IE->rend(); it != ei; ++it) { 602249423Sdim SVal V = state->getSVal(cast<Expr>(*it), LCtx); 603249423Sdim vals = getBasicVals().consVals(V, vals); 604226586Sdim } 605226586Sdim 606234353Sdim B.generateNode(IE, Pred, 607234353Sdim state->BindExpr(IE, LCtx, 608234353Sdim svalBuilder.makeCompoundVal(T, vals))); 609226586Sdim return; 610226586Sdim } 611239462Sdim 612263508Sdim // Handle scalars: int{5} and int{} and GLvalues. 613263508Sdim // Note, if the InitListExpr is a GLvalue, it means that there is an address 614263508Sdim // representing it, so it must have a single init element. 615239462Sdim assert(NumInitElements <= 1); 616239462Sdim 617239462Sdim SVal V; 618239462Sdim if (NumInitElements == 0) 619239462Sdim V = getSValBuilder().makeZeroVal(T); 620239462Sdim else 621239462Sdim V = state->getSVal(IE->getInit(0), LCtx); 622239462Sdim 623239462Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 624226586Sdim} 625226586Sdim 626226586Sdimvoid ExprEngine::VisitGuardedExpr(const Expr *Ex, 627226586Sdim const Expr *L, 628226586Sdim const Expr *R, 629226586Sdim ExplodedNode *Pred, 630226586Sdim ExplodedNodeSet &Dst) { 631251662Sdim assert(L && R); 632251662Sdim 633243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 634234353Sdim ProgramStateRef state = Pred->getState(); 635234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 636239462Sdim const CFGBlock *SrcBlock = 0; 637239462Sdim 638251662Sdim // Find the predecessor block. 639251662Sdim ProgramStateRef SrcState = state; 640239462Sdim for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) { 641239462Sdim ProgramPoint PP = N->getLocation(); 642249423Sdim if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) { 643239462Sdim assert(N->pred_size() == 1); 644239462Sdim continue; 645239462Sdim } 646249423Sdim SrcBlock = PP.castAs<BlockEdge>().getSrc(); 647251662Sdim SrcState = N->getState(); 648239462Sdim break; 649239462Sdim } 650239462Sdim 651249423Sdim assert(SrcBlock && "missing function entry"); 652249423Sdim 653239462Sdim // Find the last expression in the predecessor block. That is the 654239462Sdim // expression that is used for the value of the ternary expression. 655239462Sdim bool hasValue = false; 656239462Sdim SVal V; 657239462Sdim 658239462Sdim for (CFGBlock::const_reverse_iterator I = SrcBlock->rbegin(), 659239462Sdim E = SrcBlock->rend(); I != E; ++I) { 660239462Sdim CFGElement CE = *I; 661249423Sdim if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) { 662239462Sdim const Expr *ValEx = cast<Expr>(CS->getStmt()); 663251662Sdim ValEx = ValEx->IgnoreParens(); 664251662Sdim 665251662Sdim // For GNU extension '?:' operator, the left hand side will be an 666251662Sdim // OpaqueValueExpr, so get the underlying expression. 667251662Sdim if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L)) 668251662Sdim L = OpaqueEx->getSourceExpr(); 669251662Sdim 670251662Sdim // If the last expression in the predecessor block matches true or false 671251662Sdim // subexpression, get its the value. 672251662Sdim if (ValEx == L->IgnoreParens() || ValEx == R->IgnoreParens()) { 673251662Sdim hasValue = true; 674251662Sdim V = SrcState->getSVal(ValEx, LCtx); 675251662Sdim } 676239462Sdim break; 677239462Sdim } 678239462Sdim } 679239462Sdim 680251662Sdim if (!hasValue) 681251662Sdim V = svalBuilder.conjureSymbolVal(0, Ex, LCtx, currBldrCtx->blockCount()); 682239462Sdim 683239462Sdim // Generate a new node with the binding from the appropriate path. 684239462Sdim B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true)); 685226586Sdim} 686226586Sdim 687226586Sdimvoid ExprEngine:: 688226586SdimVisitOffsetOfExpr(const OffsetOfExpr *OOE, 689226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 690243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 691234353Sdim APSInt IV; 692234353Sdim if (OOE->EvaluateAsInt(IV, getContext())) { 693226586Sdim assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType())); 694251662Sdim assert(OOE->getType()->isBuiltinType()); 695251662Sdim assert(OOE->getType()->getAs<BuiltinType>()->isInteger()); 696251662Sdim assert(IV.isSigned() == OOE->getType()->isSignedIntegerType()); 697226586Sdim SVal X = svalBuilder.makeIntVal(IV); 698234353Sdim B.generateNode(OOE, Pred, 699234353Sdim Pred->getState()->BindExpr(OOE, Pred->getLocationContext(), 700234353Sdim X)); 701226586Sdim } 702226586Sdim // FIXME: Handle the case where __builtin_offsetof is not a constant. 703226586Sdim} 704226586Sdim 705226586Sdim 706226586Sdimvoid ExprEngine:: 707226586SdimVisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 708226586Sdim ExplodedNode *Pred, 709226586Sdim ExplodedNodeSet &Dst) { 710243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 711226586Sdim 712226586Sdim QualType T = Ex->getTypeOfArgument(); 713226586Sdim 714226586Sdim if (Ex->getKind() == UETT_SizeOf) { 715226586Sdim if (!T->isIncompleteType() && !T->isConstantSizeType()) { 716226586Sdim assert(T->isVariableArrayType() && "Unknown non-constant-sized type."); 717226586Sdim 718226586Sdim // FIXME: Add support for VLA type arguments and VLA expressions. 719226586Sdim // When that happens, we should probably refactor VLASizeChecker's code. 720226586Sdim return; 721226586Sdim } 722226586Sdim else if (T->getAs<ObjCObjectType>()) { 723226586Sdim // Some code tries to take the sizeof an ObjCObjectType, relying that 724226586Sdim // the compiler has laid out its representation. Just report Unknown 725226586Sdim // for these. 726226586Sdim return; 727226586Sdim } 728226586Sdim } 729226586Sdim 730234353Sdim APSInt Value = Ex->EvaluateKnownConstInt(getContext()); 731234353Sdim CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue()); 732226586Sdim 733234353Sdim ProgramStateRef state = Pred->getState(); 734234353Sdim state = state->BindExpr(Ex, Pred->getLocationContext(), 735234353Sdim svalBuilder.makeIntVal(amt.getQuantity(), 736226586Sdim Ex->getType())); 737234353Sdim Bldr.generateNode(Ex, Pred, state); 738226586Sdim} 739226586Sdim 740226586Sdimvoid ExprEngine::VisitUnaryOperator(const UnaryOperator* U, 741226586Sdim ExplodedNode *Pred, 742234353Sdim ExplodedNodeSet &Dst) { 743263508Sdim // FIXME: Prechecks eventually go in ::Visit(). 744263508Sdim ExplodedNodeSet CheckedSet; 745263508Sdim getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, U, *this); 746263508Sdim 747263508Sdim ExplodedNodeSet EvalSet; 748263508Sdim StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx); 749263508Sdim 750263508Sdim for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end(); 751263508Sdim I != E; ++I) { 752263508Sdim switch (U->getOpcode()) { 753234353Sdim default: { 754263508Sdim Bldr.takeNodes(*I); 755234353Sdim ExplodedNodeSet Tmp; 756263508Sdim VisitIncrementDecrementOperator(U, *I, Tmp); 757234353Sdim Bldr.addNodes(Tmp); 758263508Sdim break; 759234353Sdim } 760226586Sdim case UO_Real: { 761226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 762226586Sdim 763234353Sdim // FIXME: We don't have complex SValues yet. 764234353Sdim if (Ex->getType()->isAnyComplexType()) { 765234353Sdim // Just report "Unknown." 766234353Sdim break; 767234353Sdim } 768226586Sdim 769234353Sdim // For all other types, UO_Real is an identity operation. 770234353Sdim assert (U->getType() == Ex->getType()); 771263508Sdim ProgramStateRef state = (*I)->getState(); 772263508Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 773263508Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, 774263508Sdim state->getSVal(Ex, LCtx))); 775234353Sdim break; 776226586Sdim } 777226586Sdim 778234353Sdim case UO_Imag: { 779226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 780234353Sdim // FIXME: We don't have complex SValues yet. 781234353Sdim if (Ex->getType()->isAnyComplexType()) { 782234353Sdim // Just report "Unknown." 783234353Sdim break; 784226586Sdim } 785234353Sdim // For all other types, UO_Imag returns 0. 786263508Sdim ProgramStateRef state = (*I)->getState(); 787263508Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 788234353Sdim SVal X = svalBuilder.makeZeroVal(Ex->getType()); 789263508Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, X)); 790234353Sdim break; 791226586Sdim } 792226586Sdim 793226586Sdim case UO_Plus: 794239462Sdim assert(!U->isGLValue()); 795226586Sdim // FALL-THROUGH. 796226586Sdim case UO_Deref: 797226586Sdim case UO_AddrOf: 798226586Sdim case UO_Extension: { 799234353Sdim // FIXME: We can probably just have some magic in Environment::getSVal() 800234353Sdim // that propagates values, instead of creating a new node here. 801234353Sdim // 802226586Sdim // Unary "+" is a no-op, similar to a parentheses. We still have places 803226586Sdim // where it may be a block-level expression, so we need to 804226586Sdim // generate an extra node that just propagates the value of the 805234353Sdim // subexpression. 806226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 807263508Sdim ProgramStateRef state = (*I)->getState(); 808263508Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 809263508Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, 810263508Sdim state->getSVal(Ex, LCtx))); 811234353Sdim break; 812226586Sdim } 813226586Sdim 814226586Sdim case UO_LNot: 815226586Sdim case UO_Minus: 816226586Sdim case UO_Not: { 817239462Sdim assert (!U->isGLValue()); 818226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 819263508Sdim ProgramStateRef state = (*I)->getState(); 820263508Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 821226586Sdim 822234353Sdim // Get the value of the subexpression. 823234353Sdim SVal V = state->getSVal(Ex, LCtx); 824226586Sdim 825234353Sdim if (V.isUnknownOrUndef()) { 826263508Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V)); 827234353Sdim break; 828234353Sdim } 829226586Sdim 830234353Sdim switch (U->getOpcode()) { 831234353Sdim default: 832234353Sdim llvm_unreachable("Invalid Opcode."); 833234353Sdim case UO_Not: 834234353Sdim // FIXME: Do we need to handle promotions? 835249423Sdim state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>())); 836234353Sdim break; 837234353Sdim case UO_Minus: 838234353Sdim // FIXME: Do we need to handle promotions? 839249423Sdim state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>())); 840234353Sdim break; 841234353Sdim case UO_LNot: 842234353Sdim // C99 6.5.3.3: "The expression !E is equivalent to (0==E)." 843234353Sdim // 844234353Sdim // Note: technically we do "E == 0", but this is the same in the 845234353Sdim // transfer functions as "0 == E". 846234353Sdim SVal Result; 847249423Sdim if (Optional<Loc> LV = V.getAs<Loc>()) { 848234353Sdim Loc X = svalBuilder.makeNull(); 849249423Sdim Result = evalBinOp(state, BO_EQ, *LV, X, U->getType()); 850234353Sdim } 851249423Sdim else if (Ex->getType()->isFloatingType()) { 852249423Sdim // FIXME: handle floating point types. 853249423Sdim Result = UnknownVal(); 854249423Sdim } else { 855234353Sdim nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType())); 856249423Sdim Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X, 857234353Sdim U->getType()); 858234353Sdim } 859234353Sdim 860234353Sdim state = state->BindExpr(U, LCtx, Result); 861234353Sdim break; 862226586Sdim } 863263508Sdim Bldr.generateNode(U, *I, state); 864234353Sdim break; 865226586Sdim } 866263508Sdim } 867226586Sdim } 868234353Sdim 869263508Sdim getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, U, *this); 870234353Sdim} 871234353Sdim 872234353Sdimvoid ExprEngine::VisitIncrementDecrementOperator(const UnaryOperator* U, 873234353Sdim ExplodedNode *Pred, 874234353Sdim ExplodedNodeSet &Dst) { 875226586Sdim // Handle ++ and -- (both pre- and post-increment). 876226586Sdim assert (U->isIncrementDecrementOp()); 877226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 878226586Sdim 879234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 880234353Sdim ProgramStateRef state = Pred->getState(); 881234353Sdim SVal loc = state->getSVal(Ex, LCtx); 882234353Sdim 883234353Sdim // Perform a load. 884234353Sdim ExplodedNodeSet Tmp; 885234353Sdim evalLoad(Tmp, U, Ex, Pred, state, loc); 886234353Sdim 887234353Sdim ExplodedNodeSet Dst2; 888243830Sdim StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx); 889234353Sdim for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;++I) { 890226586Sdim 891234353Sdim state = (*I)->getState(); 892234353Sdim assert(LCtx == (*I)->getLocationContext()); 893234353Sdim SVal V2_untested = state->getSVal(Ex, LCtx); 894226586Sdim 895234353Sdim // Propagate unknown and undefined values. 896234353Sdim if (V2_untested.isUnknownOrUndef()) { 897234353Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V2_untested)); 898234353Sdim continue; 899234353Sdim } 900249423Sdim DefinedSVal V2 = V2_untested.castAs<DefinedSVal>(); 901226586Sdim 902234353Sdim // Handle all other values. 903234353Sdim BinaryOperator::Opcode Op = U->isIncrementOp() ? BO_Add : BO_Sub; 904234353Sdim 905234353Sdim // If the UnaryOperator has non-location type, use its type to create the 906234353Sdim // constant value. If the UnaryOperator has location type, create the 907234353Sdim // constant with int type and pointer width. 908234353Sdim SVal RHS; 909234353Sdim 910234353Sdim if (U->getType()->isAnyPointerType()) 911234353Sdim RHS = svalBuilder.makeArrayIndex(1); 912243830Sdim else if (U->getType()->isIntegralOrEnumerationType()) 913243830Sdim RHS = svalBuilder.makeIntVal(1, U->getType()); 914234353Sdim else 915243830Sdim RHS = UnknownVal(); 916234353Sdim 917234353Sdim SVal Result = evalBinOp(state, Op, V2, RHS, U->getType()); 918234353Sdim 919234353Sdim // Conjure a new symbol if necessary to recover precision. 920234353Sdim if (Result.isUnknown()){ 921234353Sdim DefinedOrUnknownSVal SymVal = 922243830Sdim svalBuilder.conjureSymbolVal(0, Ex, LCtx, currBldrCtx->blockCount()); 923234353Sdim Result = SymVal; 924226586Sdim 925234353Sdim // If the value is a location, ++/-- should always preserve 926234353Sdim // non-nullness. Check if the original value was non-null, and if so 927234353Sdim // propagate that constraint. 928234353Sdim if (Loc::isLocType(U->getType())) { 929234353Sdim DefinedOrUnknownSVal Constraint = 930234353Sdim svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType())); 931226586Sdim 932234353Sdim if (!state->assume(Constraint, true)) { 933234353Sdim // It isn't feasible for the original value to be null. 934234353Sdim // Propagate this constraint. 935234353Sdim Constraint = svalBuilder.evalEQ(state, SymVal, 936234353Sdim svalBuilder.makeZeroVal(U->getType())); 937226586Sdim 938234353Sdim 939234353Sdim state = state->assume(Constraint, false); 940234353Sdim assert(state); 941226586Sdim } 942226586Sdim } 943226586Sdim } 944234353Sdim 945234353Sdim // Since the lvalue-to-rvalue conversion is explicit in the AST, 946234353Sdim // we bind an l-value if the operator is prefix and an lvalue (in C++). 947239462Sdim if (U->isGLValue()) 948234353Sdim state = state->BindExpr(U, LCtx, loc); 949234353Sdim else 950234353Sdim state = state->BindExpr(U, LCtx, U->isPostfix() ? V2 : Result); 951234353Sdim 952234353Sdim // Perform the store. 953234353Sdim Bldr.takeNodes(*I); 954234353Sdim ExplodedNodeSet Dst3; 955234353Sdim evalStore(Dst3, U, U, *I, state, loc, Result); 956234353Sdim Bldr.addNodes(Dst3); 957226586Sdim } 958234353Sdim Dst.insert(Dst2); 959226586Sdim} 960