ExprEngineC.cpp revision 321369
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" 15314564Sdim#include "clang/AST/DeclCXX.h" 16226586Sdim#include "clang/StaticAnalyzer/Core/CheckerManager.h" 17226586Sdim#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 18226586Sdim 19226586Sdimusing namespace clang; 20226586Sdimusing namespace ento; 21226586Sdimusing llvm::APSInt; 22226586Sdim 23226586Sdimvoid ExprEngine::VisitBinaryOperator(const BinaryOperator* B, 24226586Sdim ExplodedNode *Pred, 25226586Sdim ExplodedNodeSet &Dst) { 26226586Sdim 27226586Sdim Expr *LHS = B->getLHS()->IgnoreParens(); 28226586Sdim Expr *RHS = B->getRHS()->IgnoreParens(); 29296417Sdim 30226586Sdim // FIXME: Prechecks eventually go in ::Visit(). 31226586Sdim ExplodedNodeSet CheckedSet; 32226586Sdim ExplodedNodeSet Tmp2; 33226586Sdim getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, B, *this); 34296417Sdim 35288943Sdim // With both the LHS and RHS evaluated, process the operation itself. 36226586Sdim for (ExplodedNodeSet::iterator it=CheckedSet.begin(), ei=CheckedSet.end(); 37226586Sdim it != ei; ++it) { 38296417Sdim 39234353Sdim ProgramStateRef state = (*it)->getState(); 40234353Sdim const LocationContext *LCtx = (*it)->getLocationContext(); 41234353Sdim SVal LeftV = state->getSVal(LHS, LCtx); 42234353Sdim SVal RightV = state->getSVal(RHS, LCtx); 43296417Sdim 44226586Sdim BinaryOperator::Opcode Op = B->getOpcode(); 45296417Sdim 46226586Sdim if (Op == BO_Assign) { 47226586Sdim // EXPERIMENTAL: "Conjured" symbols. 48226586Sdim // FIXME: Handle structs. 49234353Sdim if (RightV.isUnknown()) { 50243830Sdim unsigned Count = currBldrCtx->blockCount(); 51276479Sdim RightV = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx, 52276479Sdim Count); 53226586Sdim } 54226586Sdim // Simulate the effects of a "store": bind the value of the RHS 55226586Sdim // to the L-Value represented by the LHS. 56239462Sdim SVal ExprVal = B->isGLValue() ? LeftV : RightV; 57234353Sdim evalStore(Tmp2, B, LHS, *it, state->BindExpr(B, LCtx, ExprVal), 58234353Sdim LeftV, RightV); 59226586Sdim continue; 60226586Sdim } 61296417Sdim 62226586Sdim if (!B->isAssignmentOp()) { 63243830Sdim StmtNodeBuilder Bldr(*it, Tmp2, *currBldrCtx); 64239462Sdim 65239462Sdim if (B->isAdditiveOp()) { 66239462Sdim // If one of the operands is a location, conjure a symbol for the other 67239462Sdim // one (offset) if it's unknown so that memory arithmetic always 68239462Sdim // results in an ElementRegion. 69239462Sdim // TODO: This can be removed after we enable history tracking with 70239462Sdim // SymSymExpr. 71243830Sdim unsigned Count = currBldrCtx->blockCount(); 72249423Sdim if (LeftV.getAs<Loc>() && 73251662Sdim RHS->getType()->isIntegralOrEnumerationType() && 74251662Sdim RightV.isUnknown()) { 75243830Sdim RightV = svalBuilder.conjureSymbolVal(RHS, LCtx, RHS->getType(), 76243830Sdim Count); 77239462Sdim } 78249423Sdim if (RightV.getAs<Loc>() && 79251662Sdim LHS->getType()->isIntegralOrEnumerationType() && 80251662Sdim LeftV.isUnknown()) { 81243830Sdim LeftV = svalBuilder.conjureSymbolVal(LHS, LCtx, LHS->getType(), 82243830Sdim Count); 83239462Sdim } 84239462Sdim } 85239462Sdim 86276479Sdim // Although we don't yet model pointers-to-members, we do need to make 87276479Sdim // sure that the members of temporaries have a valid 'this' pointer for 88276479Sdim // other checks. 89276479Sdim if (B->getOpcode() == BO_PtrMemD) 90276479Sdim state = createTemporaryRegionIfNeeded(state, LCtx, LHS); 91276479Sdim 92226586Sdim // Process non-assignments except commas or short-circuited 93226586Sdim // logical expressions (LAnd and LOr). 94296417Sdim SVal Result = evalBinOp(state, Op, LeftV, RightV, B->getType()); 95226586Sdim if (Result.isUnknown()) { 96234353Sdim Bldr.generateNode(B, *it, state); 97226586Sdim continue; 98296417Sdim } 99226586Sdim 100296417Sdim state = state->BindExpr(B, LCtx, Result); 101234353Sdim Bldr.generateNode(B, *it, state); 102226586Sdim continue; 103226586Sdim } 104296417Sdim 105226586Sdim assert (B->isCompoundAssignmentOp()); 106296417Sdim 107226586Sdim switch (Op) { 108226586Sdim default: 109226586Sdim llvm_unreachable("Invalid opcode for compound assignment."); 110226586Sdim case BO_MulAssign: Op = BO_Mul; break; 111226586Sdim case BO_DivAssign: Op = BO_Div; break; 112226586Sdim case BO_RemAssign: Op = BO_Rem; break; 113226586Sdim case BO_AddAssign: Op = BO_Add; break; 114226586Sdim case BO_SubAssign: Op = BO_Sub; break; 115226586Sdim case BO_ShlAssign: Op = BO_Shl; break; 116226586Sdim case BO_ShrAssign: Op = BO_Shr; break; 117226586Sdim case BO_AndAssign: Op = BO_And; break; 118226586Sdim case BO_XorAssign: Op = BO_Xor; break; 119226586Sdim case BO_OrAssign: Op = BO_Or; break; 120226586Sdim } 121296417Sdim 122226586Sdim // Perform a load (the LHS). This performs the checks for 123226586Sdim // null dereferences, and so on. 124226586Sdim ExplodedNodeSet Tmp; 125226586Sdim SVal location = LeftV; 126234353Sdim evalLoad(Tmp, B, LHS, *it, state, location); 127296417Sdim 128226586Sdim for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end(); I != E; 129226586Sdim ++I) { 130226586Sdim 131226586Sdim state = (*I)->getState(); 132234353Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 133234353Sdim SVal V = state->getSVal(LHS, LCtx); 134296417Sdim 135226586Sdim // Get the computation type. 136226586Sdim QualType CTy = 137226586Sdim cast<CompoundAssignOperator>(B)->getComputationResultType(); 138226586Sdim CTy = getContext().getCanonicalType(CTy); 139296417Sdim 140226586Sdim QualType CLHSTy = 141226586Sdim cast<CompoundAssignOperator>(B)->getComputationLHSType(); 142226586Sdim CLHSTy = getContext().getCanonicalType(CLHSTy); 143296417Sdim 144226586Sdim QualType LTy = getContext().getCanonicalType(LHS->getType()); 145296417Sdim 146226586Sdim // Promote LHS. 147226586Sdim V = svalBuilder.evalCast(V, CLHSTy, LTy); 148296417Sdim 149226586Sdim // Compute the result of the operation. 150226586Sdim SVal Result = svalBuilder.evalCast(evalBinOp(state, Op, V, RightV, CTy), 151226586Sdim B->getType(), CTy); 152296417Sdim 153226586Sdim // EXPERIMENTAL: "Conjured" symbols. 154226586Sdim // FIXME: Handle structs. 155296417Sdim 156226586Sdim SVal LHSVal; 157296417Sdim 158234353Sdim if (Result.isUnknown()) { 159226586Sdim // The symbolic value is actually for the type of the left-hand side 160226586Sdim // expression, not the computation type, as this is the value the 161226586Sdim // LValue on the LHS will bind to. 162276479Sdim LHSVal = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx, LTy, 163243830Sdim currBldrCtx->blockCount()); 164226586Sdim // However, we need to convert the symbol to the computation type. 165226586Sdim Result = svalBuilder.evalCast(LHSVal, CTy, LTy); 166226586Sdim } 167226586Sdim else { 168226586Sdim // The left-hand side may bind to a different value then the 169226586Sdim // computation type. 170226586Sdim LHSVal = svalBuilder.evalCast(Result, LTy, CTy); 171226586Sdim } 172296417Sdim 173296417Sdim // In C++, assignment and compound assignment operators return an 174226586Sdim // lvalue. 175239462Sdim if (B->isGLValue()) 176234353Sdim state = state->BindExpr(B, LCtx, location); 177226586Sdim else 178234353Sdim state = state->BindExpr(B, LCtx, Result); 179296417Sdim 180226586Sdim evalStore(Tmp2, B, LHS, *I, state, location, LHSVal); 181226586Sdim } 182226586Sdim } 183296417Sdim 184226586Sdim // FIXME: postvisits eventually go in ::Visit() 185226586Sdim getCheckerManager().runCheckersForPostStmt(Dst, Tmp2, B, *this); 186226586Sdim} 187226586Sdim 188226586Sdimvoid ExprEngine::VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 189226586Sdim ExplodedNodeSet &Dst) { 190296417Sdim 191226586Sdim CanQualType T = getContext().getCanonicalType(BE->getType()); 192239462Sdim 193296417Sdim const BlockDecl *BD = BE->getBlockDecl(); 194239462Sdim // Get the value of the block itself. 195296417Sdim SVal V = svalBuilder.getBlockPointer(BD, T, 196261991Sdim Pred->getLocationContext(), 197261991Sdim currBldrCtx->blockCount()); 198296417Sdim 199239462Sdim ProgramStateRef State = Pred->getState(); 200296417Sdim 201239462Sdim // If we created a new MemRegion for the block, we should explicitly bind 202239462Sdim // the captured variables. 203239462Sdim if (const BlockDataRegion *BDR = 204239462Sdim dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) { 205296417Sdim 206239462Sdim BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(), 207239462Sdim E = BDR->referenced_vars_end(); 208296417Sdim 209296417Sdim auto CI = BD->capture_begin(); 210296417Sdim auto CE = BD->capture_end(); 211239462Sdim for (; I != E; ++I) { 212296417Sdim const VarRegion *capturedR = I.getCapturedRegion(); 213296417Sdim const VarRegion *originalR = I.getOriginalRegion(); 214296417Sdim 215296417Sdim // If the capture had a copy expression, use the result of evaluating 216296417Sdim // that expression, otherwise use the original value. 217296417Sdim // We rely on the invariant that the block declaration's capture variables 218296417Sdim // are a prefix of the BlockDataRegion's referenced vars (which may include 219296417Sdim // referenced globals, etc.) to enable fast lookup of the capture for a 220296417Sdim // given referenced var. 221296417Sdim const Expr *copyExpr = nullptr; 222296417Sdim if (CI != CE) { 223296417Sdim assert(CI->getVariable() == capturedR->getDecl()); 224296417Sdim copyExpr = CI->getCopyExpr(); 225296417Sdim CI++; 226296417Sdim } 227296417Sdim 228239462Sdim if (capturedR != originalR) { 229296417Sdim SVal originalV; 230321369Sdim const LocationContext *LCtx = Pred->getLocationContext(); 231296417Sdim if (copyExpr) { 232321369Sdim originalV = State->getSVal(copyExpr, LCtx); 233296417Sdim } else { 234296417Sdim originalV = State->getSVal(loc::MemRegionVal(originalR)); 235296417Sdim } 236321369Sdim State = State->bindLoc(loc::MemRegionVal(capturedR), originalV, LCtx); 237239462Sdim } 238239462Sdim } 239239462Sdim } 240296417Sdim 241226586Sdim ExplodedNodeSet Tmp; 242243830Sdim StmtNodeBuilder Bldr(Pred, Tmp, *currBldrCtx); 243234353Sdim Bldr.generateNode(BE, Pred, 244239462Sdim State->BindExpr(BE, Pred->getLocationContext(), V), 245276479Sdim nullptr, ProgramPoint::PostLValueKind); 246276479Sdim 247226586Sdim // FIXME: Move all post/pre visits to ::Visit(). 248226586Sdim getCheckerManager().runCheckersForPostStmt(Dst, Tmp, BE, *this); 249226586Sdim} 250226586Sdim 251314564SdimProgramStateRef ExprEngine::handleLValueBitCast( 252314564Sdim ProgramStateRef state, const Expr* Ex, const LocationContext* LCtx, 253314564Sdim QualType T, QualType ExTy, const CastExpr* CastE, StmtNodeBuilder& Bldr, 254314564Sdim ExplodedNode* Pred) { 255314564Sdim // Delegate to SValBuilder to process. 256314564Sdim SVal V = state->getSVal(Ex, LCtx); 257314564Sdim V = svalBuilder.evalCast(V, T, ExTy); 258314564Sdim // Negate the result if we're treating the boolean as a signed i1 259314564Sdim if (CastE->getCastKind() == CK_BooleanToSignedIntegral) 260314564Sdim V = evalMinus(V); 261314564Sdim state = state->BindExpr(CastE, LCtx, V); 262314564Sdim Bldr.generateNode(CastE, Pred, state); 263314564Sdim 264314564Sdim return state; 265314564Sdim} 266314564Sdim 267314564SdimProgramStateRef ExprEngine::handleLVectorSplat( 268314564Sdim ProgramStateRef state, const LocationContext* LCtx, const CastExpr* CastE, 269314564Sdim StmtNodeBuilder &Bldr, ExplodedNode* Pred) { 270314564Sdim // Recover some path sensitivity by conjuring a new value. 271314564Sdim QualType resultType = CastE->getType(); 272314564Sdim if (CastE->isGLValue()) 273314564Sdim resultType = getContext().getPointerType(resultType); 274314564Sdim SVal result = svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, 275314564Sdim resultType, 276314564Sdim currBldrCtx->blockCount()); 277314564Sdim state = state->BindExpr(CastE, LCtx, result); 278314564Sdim Bldr.generateNode(CastE, Pred, state); 279314564Sdim 280314564Sdim return state; 281314564Sdim} 282314564Sdim 283296417Sdimvoid ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex, 284226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 285296417Sdim 286226586Sdim ExplodedNodeSet dstPreStmt; 287226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreStmt, Pred, CastE, *this); 288296417Sdim 289234353Sdim if (CastE->getCastKind() == CK_LValueToRValue) { 290226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 291226586Sdim I!=E; ++I) { 292226586Sdim ExplodedNode *subExprNode = *I; 293234353Sdim ProgramStateRef state = subExprNode->getState(); 294234353Sdim const LocationContext *LCtx = subExprNode->getLocationContext(); 295234353Sdim evalLoad(Dst, CastE, CastE, subExprNode, state, state->getSVal(Ex, LCtx)); 296226586Sdim } 297226586Sdim return; 298226586Sdim } 299296417Sdim 300296417Sdim // All other casts. 301226586Sdim QualType T = CastE->getType(); 302226586Sdim QualType ExTy = Ex->getType(); 303296417Sdim 304226586Sdim if (const ExplicitCastExpr *ExCast=dyn_cast_or_null<ExplicitCastExpr>(CastE)) 305226586Sdim T = ExCast->getTypeAsWritten(); 306296417Sdim 307243830Sdim StmtNodeBuilder Bldr(dstPreStmt, Dst, *currBldrCtx); 308226586Sdim for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end(); 309226586Sdim I != E; ++I) { 310296417Sdim 311226586Sdim Pred = *I; 312243830Sdim ProgramStateRef state = Pred->getState(); 313243830Sdim const LocationContext *LCtx = Pred->getLocationContext(); 314243830Sdim 315226586Sdim switch (CastE->getCastKind()) { 316226586Sdim case CK_LValueToRValue: 317226586Sdim llvm_unreachable("LValueToRValue casts handled earlier."); 318226586Sdim case CK_ToVoid: 319226586Sdim continue; 320226586Sdim // The analyzer doesn't do anything special with these casts, 321226586Sdim // since it understands retain/release semantics already. 322226586Sdim case CK_ARCProduceObject: 323226586Sdim case CK_ARCConsumeObject: 324226586Sdim case CK_ARCReclaimReturnedObject: 325226586Sdim case CK_ARCExtendBlockObject: // Fall-through. 326234353Sdim case CK_CopyAndAutoreleaseBlockObject: 327234353Sdim // The analyser can ignore atomic casts for now, although some future 328234353Sdim // checkers may want to make certain that you're not modifying the same 329234353Sdim // value through atomic and nonatomic pointers. 330234353Sdim case CK_AtomicToNonAtomic: 331234353Sdim case CK_NonAtomicToAtomic: 332226586Sdim // True no-ops. 333226586Sdim case CK_NoOp: 334243830Sdim case CK_ConstructorConversion: 335243830Sdim case CK_UserDefinedConversion: 336243830Sdim case CK_FunctionToPointerDecay: 337243830Sdim case CK_BuiltinFnToFnPtr: { 338226586Sdim // Copy the SVal of Ex to CastE. 339234353Sdim ProgramStateRef state = Pred->getState(); 340234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 341234353Sdim SVal V = state->getSVal(Ex, LCtx); 342234353Sdim state = state->BindExpr(CastE, LCtx, V); 343234353Sdim Bldr.generateNode(CastE, Pred, state); 344226586Sdim continue; 345226586Sdim } 346243830Sdim case CK_MemberPointerToBoolean: 347314564Sdim case CK_PointerToBoolean: { 348314564Sdim SVal V = state->getSVal(Ex, LCtx); 349314564Sdim auto PTMSV = V.getAs<nonloc::PointerToMember>(); 350314564Sdim if (PTMSV) 351314564Sdim V = svalBuilder.makeTruthVal(!PTMSV->isNullMemberPointer(), ExTy); 352314564Sdim if (V.isUndef() || PTMSV) { 353314564Sdim state = state->BindExpr(CastE, LCtx, V); 354314564Sdim Bldr.generateNode(CastE, Pred, state); 355314564Sdim continue; 356314564Sdim } 357314564Sdim // Explicitly proceed with default handler for this case cascade. 358314564Sdim state = 359314564Sdim handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred); 360314564Sdim continue; 361314564Sdim } 362226586Sdim case CK_Dependent: 363226586Sdim case CK_ArrayToPointerDecay: 364226586Sdim case CK_BitCast: 365276479Sdim case CK_AddressSpaceConversion: 366296417Sdim case CK_BooleanToSignedIntegral: 367226586Sdim case CK_NullToPointer: 368226586Sdim case CK_IntegralToPointer: 369314564Sdim case CK_PointerToIntegral: { 370314564Sdim SVal V = state->getSVal(Ex, LCtx); 371314564Sdim if (V.getAs<nonloc::PointerToMember>()) { 372314564Sdim state = state->BindExpr(CastE, LCtx, UnknownVal()); 373314564Sdim Bldr.generateNode(CastE, Pred, state); 374314564Sdim continue; 375314564Sdim } 376314564Sdim // Explicitly proceed with default handler for this case cascade. 377314564Sdim state = 378314564Sdim handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred); 379314564Sdim continue; 380314564Sdim } 381226586Sdim case CK_IntegralToBoolean: 382226586Sdim case CK_IntegralToFloating: 383226586Sdim case CK_FloatingToIntegral: 384226586Sdim case CK_FloatingToBoolean: 385226586Sdim case CK_FloatingCast: 386226586Sdim case CK_FloatingRealToComplex: 387226586Sdim case CK_FloatingComplexToReal: 388226586Sdim case CK_FloatingComplexToBoolean: 389226586Sdim case CK_FloatingComplexCast: 390226586Sdim case CK_FloatingComplexToIntegralComplex: 391226586Sdim case CK_IntegralRealToComplex: 392226586Sdim case CK_IntegralComplexToReal: 393226586Sdim case CK_IntegralComplexToBoolean: 394226586Sdim case CK_IntegralComplexCast: 395226586Sdim case CK_IntegralComplexToFloatingComplex: 396226586Sdim case CK_CPointerToObjCPointerCast: 397226586Sdim case CK_BlockPointerToObjCPointerCast: 398296417Sdim case CK_AnyPointerToBlockPointerCast: 399296417Sdim case CK_ObjCObjectLValueCast: 400261991Sdim case CK_ZeroToOCLEvent: 401314564Sdim case CK_ZeroToOCLQueue: 402314564Sdim case CK_IntToOCLSampler: 403261991Sdim case CK_LValueBitCast: { 404314564Sdim state = 405314564Sdim handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred); 406226586Sdim continue; 407226586Sdim } 408296417Sdim case CK_IntegralCast: { 409296417Sdim // Delegate to SValBuilder to process. 410296417Sdim SVal V = state->getSVal(Ex, LCtx); 411296417Sdim V = svalBuilder.evalIntegralCast(state, V, T, ExTy); 412296417Sdim state = state->BindExpr(CastE, LCtx, V); 413296417Sdim Bldr.generateNode(CastE, Pred, state); 414296417Sdim continue; 415296417Sdim } 416226586Sdim case CK_DerivedToBase: 417226586Sdim case CK_UncheckedDerivedToBase: { 418226586Sdim // For DerivedToBase cast, delegate to the store manager. 419234353Sdim SVal val = state->getSVal(Ex, LCtx); 420239462Sdim val = getStoreManager().evalDerivedToBase(val, CastE); 421234353Sdim state = state->BindExpr(CastE, LCtx, val); 422234353Sdim Bldr.generateNode(CastE, Pred, state); 423226586Sdim continue; 424226586Sdim } 425234353Sdim // Handle C++ dyn_cast. 426234353Sdim case CK_Dynamic: { 427234353Sdim SVal val = state->getSVal(Ex, LCtx); 428234353Sdim 429234353Sdim // Compute the type of the result. 430234353Sdim QualType resultType = CastE->getType(); 431239462Sdim if (CastE->isGLValue()) 432234353Sdim resultType = getContext().getPointerType(resultType); 433234353Sdim 434234353Sdim bool Failed = false; 435234353Sdim 436234353Sdim // Check if the value being cast evaluates to 0. 437234353Sdim if (val.isZeroConstant()) 438234353Sdim Failed = true; 439234353Sdim // Else, evaluate the cast. 440234353Sdim else 441314564Sdim val = getStoreManager().attemptDownCast(val, T, Failed); 442234353Sdim 443234353Sdim if (Failed) { 444234353Sdim if (T->isReferenceType()) { 445234353Sdim // A bad_cast exception is thrown if input value is a reference. 446234353Sdim // Currently, we model this, by generating a sink. 447243830Sdim Bldr.generateSink(CastE, Pred, state); 448234353Sdim continue; 449234353Sdim } else { 450234353Sdim // If the cast fails on a pointer, bind to 0. 451234353Sdim state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull()); 452234353Sdim } 453234353Sdim } else { 454234353Sdim // If we don't know if the cast succeeded, conjure a new symbol. 455234353Sdim if (val.isUnknown()) { 456243830Sdim DefinedOrUnknownSVal NewSym = 457276479Sdim svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType, 458243830Sdim currBldrCtx->blockCount()); 459234353Sdim state = state->BindExpr(CastE, LCtx, NewSym); 460296417Sdim } else 461234353Sdim // Else, bind to the derived region value. 462234353Sdim state = state->BindExpr(CastE, LCtx, val); 463234353Sdim } 464234353Sdim Bldr.generateNode(CastE, Pred, state); 465234353Sdim continue; 466234353Sdim } 467314564Sdim case CK_BaseToDerived: { 468314564Sdim SVal val = state->getSVal(Ex, LCtx); 469314564Sdim QualType resultType = CastE->getType(); 470314564Sdim if (CastE->isGLValue()) 471314564Sdim resultType = getContext().getPointerType(resultType); 472314564Sdim 473314564Sdim bool Failed = false; 474314564Sdim 475314564Sdim if (!val.isConstant()) { 476314564Sdim val = getStoreManager().attemptDownCast(val, T, Failed); 477314564Sdim } 478314564Sdim 479314564Sdim // Failed to cast or the result is unknown, fall back to conservative. 480314564Sdim if (Failed || val.isUnknown()) { 481314564Sdim val = 482314564Sdim svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType, 483314564Sdim currBldrCtx->blockCount()); 484314564Sdim } 485314564Sdim state = state->BindExpr(CastE, LCtx, val); 486314564Sdim Bldr.generateNode(CastE, Pred, state); 487314564Sdim continue; 488314564Sdim } 489243830Sdim case CK_NullToMemberPointer: { 490314564Sdim SVal V = svalBuilder.getMemberPointer(nullptr); 491243830Sdim state = state->BindExpr(CastE, LCtx, V); 492243830Sdim Bldr.generateNode(CastE, Pred, state); 493243830Sdim continue; 494243830Sdim } 495314564Sdim case CK_DerivedToBaseMemberPointer: 496314564Sdim case CK_BaseToDerivedMemberPointer: 497314564Sdim case CK_ReinterpretMemberPointer: { 498314564Sdim SVal V = state->getSVal(Ex, LCtx); 499314564Sdim if (auto PTMSV = V.getAs<nonloc::PointerToMember>()) { 500314564Sdim SVal CastedPTMSV = svalBuilder.makePointerToMember( 501314564Sdim getBasicVals().accumCXXBase( 502314564Sdim llvm::make_range<CastExpr::path_const_iterator>( 503314564Sdim CastE->path_begin(), CastE->path_end()), *PTMSV)); 504314564Sdim state = state->BindExpr(CastE, LCtx, CastedPTMSV); 505314564Sdim Bldr.generateNode(CastE, Pred, state); 506314564Sdim continue; 507314564Sdim } 508314564Sdim // Explicitly proceed with default handler for this case cascade. 509314564Sdim state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred); 510314564Sdim continue; 511314564Sdim } 512234353Sdim // Various C++ casts that are not handled yet. 513226586Sdim case CK_ToUnion: 514261991Sdim case CK_VectorSplat: { 515314564Sdim state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred); 516226586Sdim continue; 517226586Sdim } 518226586Sdim } 519226586Sdim } 520226586Sdim} 521226586Sdim 522226586Sdimvoid ExprEngine::VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 523226586Sdim ExplodedNode *Pred, 524226586Sdim ExplodedNodeSet &Dst) { 525243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 526234353Sdim 527251662Sdim ProgramStateRef State = Pred->getState(); 528251662Sdim const LocationContext *LCtx = Pred->getLocationContext(); 529251662Sdim 530251662Sdim const Expr *Init = CL->getInitializer(); 531251662Sdim SVal V = State->getSVal(CL->getInitializer(), LCtx); 532296417Sdim 533251662Sdim if (isa<CXXConstructExpr>(Init)) { 534251662Sdim // No work needed. Just pass the value up to this expression. 535251662Sdim } else { 536251662Sdim assert(isa<InitListExpr>(Init)); 537251662Sdim Loc CLLoc = State->getLValue(CL, LCtx); 538321369Sdim State = State->bindLoc(CLLoc, V, LCtx); 539239462Sdim 540314564Sdim if (CL->isGLValue()) 541251662Sdim V = CLLoc; 542251662Sdim } 543251662Sdim 544251662Sdim B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V)); 545226586Sdim} 546226586Sdim 547226586Sdimvoid ExprEngine::VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 548226586Sdim ExplodedNodeSet &Dst) { 549226586Sdim // Assumption: The CFG has one DeclStmt per Decl. 550249423Sdim const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin()); 551249423Sdim 552249423Sdim if (!VD) { 553234353Sdim //TODO:AZ: remove explicit insertion after refactoring is done. 554234353Sdim Dst.insert(Pred); 555226586Sdim return; 556234353Sdim } 557296417Sdim 558226586Sdim // FIXME: all pre/post visits should eventually be handled by ::Visit(). 559226586Sdim ExplodedNodeSet dstPreVisit; 560226586Sdim getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this); 561296417Sdim 562261991Sdim ExplodedNodeSet dstEvaluated; 563261991Sdim StmtNodeBuilder B(dstPreVisit, dstEvaluated, *currBldrCtx); 564226586Sdim for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end(); 565226586Sdim I!=E; ++I) { 566226586Sdim ExplodedNode *N = *I; 567234353Sdim ProgramStateRef state = N->getState(); 568249423Sdim const LocationContext *LC = N->getLocationContext(); 569249423Sdim 570226586Sdim // Decls without InitExpr are not initialized explicitly. 571226586Sdim if (const Expr *InitEx = VD->getInit()) { 572249423Sdim 573249423Sdim // Note in the state that the initialization has occurred. 574249423Sdim ExplodedNode *UpdatedN = N; 575239462Sdim SVal InitVal = state->getSVal(InitEx, LC); 576234353Sdim 577296417Sdim assert(DS->isSingleDecl()); 578296417Sdim if (auto *CtorExpr = findDirectConstructorForCurrentCFGElement()) { 579296417Sdim assert(InitEx->IgnoreImplicit() == CtorExpr); 580296417Sdim (void)CtorExpr; 581239462Sdim // We constructed the object directly in the variable. 582239462Sdim // No need to bind anything. 583249423Sdim B.generateNode(DS, UpdatedN, state); 584239462Sdim } else { 585239462Sdim // We bound the temp obj region to the CXXConstructExpr. Now recover 586239462Sdim // the lazy compound value when the variable is not a reference. 587249423Sdim if (AMgr.getLangOpts().CPlusPlus && VD->getType()->isRecordType() && 588249423Sdim !VD->getType()->isReferenceType()) { 589249423Sdim if (Optional<loc::MemRegionVal> M = 590249423Sdim InitVal.getAs<loc::MemRegionVal>()) { 591249423Sdim InitVal = state->getSVal(M->getRegion()); 592249423Sdim assert(InitVal.getAs<nonloc::LazyCompoundVal>()); 593249423Sdim } 594239462Sdim } 595296417Sdim 596239462Sdim // Recover some path-sensitivity if a scalar value evaluated to 597239462Sdim // UnknownVal. 598239462Sdim if (InitVal.isUnknown()) { 599239462Sdim QualType Ty = InitEx->getType(); 600239462Sdim if (InitEx->isGLValue()) { 601239462Sdim Ty = getContext().getPointerType(Ty); 602239462Sdim } 603239462Sdim 604276479Sdim InitVal = svalBuilder.conjureSymbolVal(nullptr, InitEx, LC, Ty, 605243830Sdim currBldrCtx->blockCount()); 606239462Sdim } 607249423Sdim 608249423Sdim 609249423Sdim B.takeNodes(UpdatedN); 610239462Sdim ExplodedNodeSet Dst2; 611249423Sdim evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true); 612239462Sdim B.addNodes(Dst2); 613226586Sdim } 614226586Sdim } 615226586Sdim else { 616243830Sdim B.generateNode(DS, N, state); 617226586Sdim } 618226586Sdim } 619261991Sdim 620261991Sdim getCheckerManager().runCheckersForPostStmt(Dst, B.getResults(), DS, *this); 621226586Sdim} 622226586Sdim 623226586Sdimvoid ExprEngine::VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 624226586Sdim ExplodedNodeSet &Dst) { 625226586Sdim assert(B->getOpcode() == BO_LAnd || 626226586Sdim B->getOpcode() == BO_LOr); 627234353Sdim 628243830Sdim StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx); 629234353Sdim ProgramStateRef state = Pred->getState(); 630239462Sdim 631239462Sdim ExplodedNode *N = Pred; 632249423Sdim while (!N->getLocation().getAs<BlockEntrance>()) { 633239462Sdim ProgramPoint P = N->getLocation(); 634249423Sdim assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>()); 635239462Sdim (void) P; 636239462Sdim assert(N->pred_size() == 1); 637239462Sdim N = *N->pred_begin(); 638226586Sdim } 639239462Sdim assert(N->pred_size() == 1); 640239462Sdim N = *N->pred_begin(); 641249423Sdim BlockEdge BE = N->getLocation().castAs<BlockEdge>(); 642239462Sdim SVal X; 643239462Sdim 644239462Sdim // Determine the value of the expression by introspecting how we 645239462Sdim // got this location in the CFG. This requires looking at the previous 646239462Sdim // block we were in and what kind of control-flow transfer was involved. 647239462Sdim const CFGBlock *SrcBlock = BE.getSrc(); 648239462Sdim // The only terminator (if there is one) that makes sense is a logical op. 649239462Sdim CFGTerminator T = SrcBlock->getTerminator(); 650239462Sdim if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) { 651239462Sdim (void) Term; 652239462Sdim assert(Term->isLogicalOp()); 653239462Sdim assert(SrcBlock->succ_size() == 2); 654239462Sdim // Did we take the true or false branch? 655239462Sdim unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 1 : 0; 656239462Sdim X = svalBuilder.makeIntVal(constant, B->getType()); 657239462Sdim } 658226586Sdim else { 659239462Sdim // If there is no terminator, by construction the last statement 660239462Sdim // in SrcBlock is the value of the enclosing expression. 661243830Sdim // However, we still need to constrain that value to be 0 or 1. 662239462Sdim assert(!SrcBlock->empty()); 663249423Sdim CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>(); 664243830Sdim const Expr *RHS = cast<Expr>(Elem.getStmt()); 665243830Sdim SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext()); 666243830Sdim 667249423Sdim if (RHSVal.isUndef()) { 668249423Sdim X = RHSVal; 669249423Sdim } else { 670314564Sdim // We evaluate "RHSVal != 0" expression which result in 0 if the value is 671314564Sdim // known to be false, 1 if the value is known to be true and a new symbol 672314564Sdim // when the assumption is unknown. 673314564Sdim nonloc::ConcreteInt Zero(getBasicVals().getValue(0, B->getType())); 674314564Sdim X = evalBinOp(N->getState(), BO_NE, 675314564Sdim svalBuilder.evalCast(RHSVal, B->getType(), RHS->getType()), 676314564Sdim Zero, B->getType()); 677243830Sdim } 678226586Sdim } 679239462Sdim Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X)); 680226586Sdim} 681226586Sdim 682226586Sdimvoid ExprEngine::VisitInitListExpr(const InitListExpr *IE, 683226586Sdim ExplodedNode *Pred, 684226586Sdim ExplodedNodeSet &Dst) { 685243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 686226586Sdim 687234353Sdim ProgramStateRef state = Pred->getState(); 688234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 689226586Sdim QualType T = getContext().getCanonicalType(IE->getType()); 690226586Sdim unsigned NumInitElements = IE->getNumInits(); 691261991Sdim 692261991Sdim if (!IE->isGLValue() && 693261991Sdim (T->isArrayType() || T->isRecordType() || T->isVectorType() || 694261991Sdim T->isAnyComplexType())) { 695226586Sdim llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList(); 696296417Sdim 697226586Sdim // Handle base case where the initializer has no elements. 698226586Sdim // e.g: static int* myArray[] = {}; 699226586Sdim if (NumInitElements == 0) { 700226586Sdim SVal V = svalBuilder.makeCompoundVal(T, vals); 701234353Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 702226586Sdim return; 703226586Sdim } 704296417Sdim 705226586Sdim for (InitListExpr::const_reverse_iterator it = IE->rbegin(), 706226586Sdim ei = IE->rend(); it != ei; ++it) { 707249423Sdim SVal V = state->getSVal(cast<Expr>(*it), LCtx); 708314564Sdim vals = getBasicVals().prependSVal(V, vals); 709226586Sdim } 710296417Sdim 711234353Sdim B.generateNode(IE, Pred, 712234353Sdim state->BindExpr(IE, LCtx, 713234353Sdim svalBuilder.makeCompoundVal(T, vals))); 714226586Sdim return; 715226586Sdim } 716239462Sdim 717261991Sdim // Handle scalars: int{5} and int{} and GLvalues. 718261991Sdim // Note, if the InitListExpr is a GLvalue, it means that there is an address 719261991Sdim // representing it, so it must have a single init element. 720239462Sdim assert(NumInitElements <= 1); 721239462Sdim 722239462Sdim SVal V; 723239462Sdim if (NumInitElements == 0) 724239462Sdim V = getSValBuilder().makeZeroVal(T); 725239462Sdim else 726239462Sdim V = state->getSVal(IE->getInit(0), LCtx); 727239462Sdim 728239462Sdim B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V)); 729226586Sdim} 730226586Sdim 731226586Sdimvoid ExprEngine::VisitGuardedExpr(const Expr *Ex, 732296417Sdim const Expr *L, 733226586Sdim const Expr *R, 734226586Sdim ExplodedNode *Pred, 735226586Sdim ExplodedNodeSet &Dst) { 736251662Sdim assert(L && R); 737251662Sdim 738243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 739234353Sdim ProgramStateRef state = Pred->getState(); 740234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 741276479Sdim const CFGBlock *SrcBlock = nullptr; 742239462Sdim 743251662Sdim // Find the predecessor block. 744251662Sdim ProgramStateRef SrcState = state; 745239462Sdim for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) { 746239462Sdim ProgramPoint PP = N->getLocation(); 747249423Sdim if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) { 748239462Sdim assert(N->pred_size() == 1); 749239462Sdim continue; 750239462Sdim } 751249423Sdim SrcBlock = PP.castAs<BlockEdge>().getSrc(); 752251662Sdim SrcState = N->getState(); 753239462Sdim break; 754239462Sdim } 755239462Sdim 756249423Sdim assert(SrcBlock && "missing function entry"); 757249423Sdim 758239462Sdim // Find the last expression in the predecessor block. That is the 759239462Sdim // expression that is used for the value of the ternary expression. 760239462Sdim bool hasValue = false; 761239462Sdim SVal V; 762239462Sdim 763296417Sdim for (CFGElement CE : llvm::reverse(*SrcBlock)) { 764249423Sdim if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) { 765239462Sdim const Expr *ValEx = cast<Expr>(CS->getStmt()); 766251662Sdim ValEx = ValEx->IgnoreParens(); 767251662Sdim 768251662Sdim // For GNU extension '?:' operator, the left hand side will be an 769251662Sdim // OpaqueValueExpr, so get the underlying expression. 770251662Sdim if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L)) 771251662Sdim L = OpaqueEx->getSourceExpr(); 772251662Sdim 773251662Sdim // If the last expression in the predecessor block matches true or false 774251662Sdim // subexpression, get its the value. 775251662Sdim if (ValEx == L->IgnoreParens() || ValEx == R->IgnoreParens()) { 776251662Sdim hasValue = true; 777251662Sdim V = SrcState->getSVal(ValEx, LCtx); 778251662Sdim } 779239462Sdim break; 780239462Sdim } 781239462Sdim } 782239462Sdim 783251662Sdim if (!hasValue) 784276479Sdim V = svalBuilder.conjureSymbolVal(nullptr, Ex, LCtx, 785276479Sdim currBldrCtx->blockCount()); 786239462Sdim 787239462Sdim // Generate a new node with the binding from the appropriate path. 788239462Sdim B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true)); 789226586Sdim} 790226586Sdim 791226586Sdimvoid ExprEngine:: 792296417SdimVisitOffsetOfExpr(const OffsetOfExpr *OOE, 793226586Sdim ExplodedNode *Pred, ExplodedNodeSet &Dst) { 794243830Sdim StmtNodeBuilder B(Pred, Dst, *currBldrCtx); 795234353Sdim APSInt IV; 796234353Sdim if (OOE->EvaluateAsInt(IV, getContext())) { 797226586Sdim assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType())); 798251662Sdim assert(OOE->getType()->isBuiltinType()); 799251662Sdim assert(OOE->getType()->getAs<BuiltinType>()->isInteger()); 800251662Sdim assert(IV.isSigned() == OOE->getType()->isSignedIntegerType()); 801226586Sdim SVal X = svalBuilder.makeIntVal(IV); 802234353Sdim B.generateNode(OOE, Pred, 803234353Sdim Pred->getState()->BindExpr(OOE, Pred->getLocationContext(), 804234353Sdim X)); 805226586Sdim } 806226586Sdim // FIXME: Handle the case where __builtin_offsetof is not a constant. 807226586Sdim} 808226586Sdim 809226586Sdim 810226586Sdimvoid ExprEngine:: 811226586SdimVisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 812226586Sdim ExplodedNode *Pred, 813226586Sdim ExplodedNodeSet &Dst) { 814276479Sdim // FIXME: Prechecks eventually go in ::Visit(). 815276479Sdim ExplodedNodeSet CheckedSet; 816276479Sdim getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, Ex, *this); 817226586Sdim 818276479Sdim ExplodedNodeSet EvalSet; 819276479Sdim StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx); 820276479Sdim 821226586Sdim QualType T = Ex->getTypeOfArgument(); 822276479Sdim 823276479Sdim for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end(); 824276479Sdim I != E; ++I) { 825276479Sdim if (Ex->getKind() == UETT_SizeOf) { 826276479Sdim if (!T->isIncompleteType() && !T->isConstantSizeType()) { 827276479Sdim assert(T->isVariableArrayType() && "Unknown non-constant-sized type."); 828296417Sdim 829276479Sdim // FIXME: Add support for VLA type arguments and VLA expressions. 830276479Sdim // When that happens, we should probably refactor VLASizeChecker's code. 831276479Sdim continue; 832276479Sdim } else if (T->getAs<ObjCObjectType>()) { 833276479Sdim // Some code tries to take the sizeof an ObjCObjectType, relying that 834276479Sdim // the compiler has laid out its representation. Just report Unknown 835276479Sdim // for these. 836276479Sdim continue; 837276479Sdim } 838226586Sdim } 839296417Sdim 840276479Sdim APSInt Value = Ex->EvaluateKnownConstInt(getContext()); 841276479Sdim CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue()); 842296417Sdim 843276479Sdim ProgramStateRef state = (*I)->getState(); 844276479Sdim state = state->BindExpr(Ex, (*I)->getLocationContext(), 845276479Sdim svalBuilder.makeIntVal(amt.getQuantity(), 846276479Sdim Ex->getType())); 847276479Sdim Bldr.generateNode(Ex, *I, state); 848226586Sdim } 849276479Sdim 850276479Sdim getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, Ex, *this); 851226586Sdim} 852226586Sdim 853314564Sdimvoid ExprEngine::handleUOExtension(ExplodedNodeSet::iterator I, 854314564Sdim const UnaryOperator *U, 855314564Sdim StmtNodeBuilder &Bldr) { 856314564Sdim // FIXME: We can probably just have some magic in Environment::getSVal() 857314564Sdim // that propagates values, instead of creating a new node here. 858314564Sdim // 859314564Sdim // Unary "+" is a no-op, similar to a parentheses. We still have places 860314564Sdim // where it may be a block-level expression, so we need to 861314564Sdim // generate an extra node that just propagates the value of the 862314564Sdim // subexpression. 863314564Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 864314564Sdim ProgramStateRef state = (*I)->getState(); 865314564Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 866314564Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, 867314564Sdim state->getSVal(Ex, LCtx))); 868314564Sdim} 869314564Sdim 870314564Sdimvoid ExprEngine::VisitUnaryOperator(const UnaryOperator* U, ExplodedNode *Pred, 871234353Sdim ExplodedNodeSet &Dst) { 872261991Sdim // FIXME: Prechecks eventually go in ::Visit(). 873261991Sdim ExplodedNodeSet CheckedSet; 874261991Sdim getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, U, *this); 875261991Sdim 876261991Sdim ExplodedNodeSet EvalSet; 877261991Sdim StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx); 878261991Sdim 879261991Sdim for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end(); 880261991Sdim I != E; ++I) { 881261991Sdim switch (U->getOpcode()) { 882234353Sdim default: { 883261991Sdim Bldr.takeNodes(*I); 884234353Sdim ExplodedNodeSet Tmp; 885261991Sdim VisitIncrementDecrementOperator(U, *I, Tmp); 886234353Sdim Bldr.addNodes(Tmp); 887261991Sdim break; 888234353Sdim } 889226586Sdim case UO_Real: { 890226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 891296417Sdim 892234353Sdim // FIXME: We don't have complex SValues yet. 893234353Sdim if (Ex->getType()->isAnyComplexType()) { 894234353Sdim // Just report "Unknown." 895234353Sdim break; 896234353Sdim } 897296417Sdim 898234353Sdim // For all other types, UO_Real is an identity operation. 899234353Sdim assert (U->getType() == Ex->getType()); 900261991Sdim ProgramStateRef state = (*I)->getState(); 901261991Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 902261991Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, 903261991Sdim state->getSVal(Ex, LCtx))); 904234353Sdim break; 905226586Sdim } 906296417Sdim 907296417Sdim case UO_Imag: { 908226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 909234353Sdim // FIXME: We don't have complex SValues yet. 910234353Sdim if (Ex->getType()->isAnyComplexType()) { 911234353Sdim // Just report "Unknown." 912234353Sdim break; 913226586Sdim } 914234353Sdim // For all other types, UO_Imag returns 0. 915261991Sdim ProgramStateRef state = (*I)->getState(); 916261991Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 917234353Sdim SVal X = svalBuilder.makeZeroVal(Ex->getType()); 918261991Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, X)); 919234353Sdim break; 920226586Sdim } 921296417Sdim 922314564Sdim case UO_AddrOf: { 923314564Sdim // Process pointer-to-member address operation. 924314564Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 925314564Sdim if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex)) { 926314564Sdim const ValueDecl *VD = DRE->getDecl(); 927314564Sdim 928314564Sdim if (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD)) { 929314564Sdim ProgramStateRef State = (*I)->getState(); 930314564Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 931314564Sdim SVal SV = svalBuilder.getMemberPointer(cast<DeclaratorDecl>(VD)); 932314564Sdim Bldr.generateNode(U, *I, State->BindExpr(U, LCtx, SV)); 933314564Sdim break; 934314564Sdim } 935314564Sdim } 936314564Sdim // Explicitly proceed with default handler for this case cascade. 937314564Sdim handleUOExtension(I, U, Bldr); 938314564Sdim break; 939314564Sdim } 940226586Sdim case UO_Plus: 941239462Sdim assert(!U->isGLValue()); 942226586Sdim // FALL-THROUGH. 943226586Sdim case UO_Deref: 944226586Sdim case UO_Extension: { 945314564Sdim handleUOExtension(I, U, Bldr); 946234353Sdim break; 947226586Sdim } 948296417Sdim 949226586Sdim case UO_LNot: 950226586Sdim case UO_Minus: 951226586Sdim case UO_Not: { 952239462Sdim assert (!U->isGLValue()); 953226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 954261991Sdim ProgramStateRef state = (*I)->getState(); 955261991Sdim const LocationContext *LCtx = (*I)->getLocationContext(); 956296417Sdim 957234353Sdim // Get the value of the subexpression. 958234353Sdim SVal V = state->getSVal(Ex, LCtx); 959296417Sdim 960234353Sdim if (V.isUnknownOrUndef()) { 961261991Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V)); 962234353Sdim break; 963234353Sdim } 964296417Sdim 965234353Sdim switch (U->getOpcode()) { 966234353Sdim default: 967234353Sdim llvm_unreachable("Invalid Opcode."); 968234353Sdim case UO_Not: 969234353Sdim // FIXME: Do we need to handle promotions? 970249423Sdim state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>())); 971234353Sdim break; 972234353Sdim case UO_Minus: 973234353Sdim // FIXME: Do we need to handle promotions? 974249423Sdim state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>())); 975234353Sdim break; 976234353Sdim case UO_LNot: 977234353Sdim // C99 6.5.3.3: "The expression !E is equivalent to (0==E)." 978234353Sdim // 979234353Sdim // Note: technically we do "E == 0", but this is the same in the 980234353Sdim // transfer functions as "0 == E". 981296417Sdim SVal Result; 982249423Sdim if (Optional<Loc> LV = V.getAs<Loc>()) { 983321369Sdim Loc X = svalBuilder.makeNullWithType(Ex->getType()); 984249423Sdim Result = evalBinOp(state, BO_EQ, *LV, X, U->getType()); 985321369Sdim } else if (Ex->getType()->isFloatingType()) { 986249423Sdim // FIXME: handle floating point types. 987249423Sdim Result = UnknownVal(); 988249423Sdim } else { 989234353Sdim nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType())); 990249423Sdim Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X, 991234353Sdim U->getType()); 992234353Sdim } 993296417Sdim 994296417Sdim state = state->BindExpr(U, LCtx, Result); 995234353Sdim break; 996226586Sdim } 997261991Sdim Bldr.generateNode(U, *I, state); 998234353Sdim break; 999226586Sdim } 1000261991Sdim } 1001226586Sdim } 1002234353Sdim 1003261991Sdim getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, U, *this); 1004234353Sdim} 1005234353Sdim 1006234353Sdimvoid ExprEngine::VisitIncrementDecrementOperator(const UnaryOperator* U, 1007234353Sdim ExplodedNode *Pred, 1008234353Sdim ExplodedNodeSet &Dst) { 1009226586Sdim // Handle ++ and -- (both pre- and post-increment). 1010226586Sdim assert (U->isIncrementDecrementOp()); 1011226586Sdim const Expr *Ex = U->getSubExpr()->IgnoreParens(); 1012296417Sdim 1013234353Sdim const LocationContext *LCtx = Pred->getLocationContext(); 1014234353Sdim ProgramStateRef state = Pred->getState(); 1015234353Sdim SVal loc = state->getSVal(Ex, LCtx); 1016296417Sdim 1017234353Sdim // Perform a load. 1018234353Sdim ExplodedNodeSet Tmp; 1019234353Sdim evalLoad(Tmp, U, Ex, Pred, state, loc); 1020296417Sdim 1021234353Sdim ExplodedNodeSet Dst2; 1022243830Sdim StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx); 1023234353Sdim for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;++I) { 1024296417Sdim 1025234353Sdim state = (*I)->getState(); 1026234353Sdim assert(LCtx == (*I)->getLocationContext()); 1027234353Sdim SVal V2_untested = state->getSVal(Ex, LCtx); 1028296417Sdim 1029234353Sdim // Propagate unknown and undefined values. 1030234353Sdim if (V2_untested.isUnknownOrUndef()) { 1031234353Sdim Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V2_untested)); 1032234353Sdim continue; 1033234353Sdim } 1034249423Sdim DefinedSVal V2 = V2_untested.castAs<DefinedSVal>(); 1035296417Sdim 1036234353Sdim // Handle all other values. 1037234353Sdim BinaryOperator::Opcode Op = U->isIncrementOp() ? BO_Add : BO_Sub; 1038296417Sdim 1039234353Sdim // If the UnaryOperator has non-location type, use its type to create the 1040234353Sdim // constant value. If the UnaryOperator has location type, create the 1041234353Sdim // constant with int type and pointer width. 1042234353Sdim SVal RHS; 1043296417Sdim 1044234353Sdim if (U->getType()->isAnyPointerType()) 1045234353Sdim RHS = svalBuilder.makeArrayIndex(1); 1046243830Sdim else if (U->getType()->isIntegralOrEnumerationType()) 1047243830Sdim RHS = svalBuilder.makeIntVal(1, U->getType()); 1048234353Sdim else 1049243830Sdim RHS = UnknownVal(); 1050296417Sdim 1051234353Sdim SVal Result = evalBinOp(state, Op, V2, RHS, U->getType()); 1052296417Sdim 1053234353Sdim // Conjure a new symbol if necessary to recover precision. 1054234353Sdim if (Result.isUnknown()){ 1055234353Sdim DefinedOrUnknownSVal SymVal = 1056321369Sdim svalBuilder.conjureSymbolVal(nullptr, U, LCtx, 1057276479Sdim currBldrCtx->blockCount()); 1058234353Sdim Result = SymVal; 1059296417Sdim 1060234353Sdim // If the value is a location, ++/-- should always preserve 1061234353Sdim // non-nullness. Check if the original value was non-null, and if so 1062234353Sdim // propagate that constraint. 1063234353Sdim if (Loc::isLocType(U->getType())) { 1064234353Sdim DefinedOrUnknownSVal Constraint = 1065234353Sdim svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType())); 1066296417Sdim 1067234353Sdim if (!state->assume(Constraint, true)) { 1068234353Sdim // It isn't feasible for the original value to be null. 1069234353Sdim // Propagate this constraint. 1070234353Sdim Constraint = svalBuilder.evalEQ(state, SymVal, 1071234353Sdim svalBuilder.makeZeroVal(U->getType())); 1072296417Sdim 1073296417Sdim 1074234353Sdim state = state->assume(Constraint, false); 1075234353Sdim assert(state); 1076226586Sdim } 1077226586Sdim } 1078226586Sdim } 1079296417Sdim 1080234353Sdim // Since the lvalue-to-rvalue conversion is explicit in the AST, 1081234353Sdim // we bind an l-value if the operator is prefix and an lvalue (in C++). 1082239462Sdim if (U->isGLValue()) 1083234353Sdim state = state->BindExpr(U, LCtx, loc); 1084234353Sdim else 1085234353Sdim state = state->BindExpr(U, LCtx, U->isPostfix() ? V2 : Result); 1086296417Sdim 1087234353Sdim // Perform the store. 1088234353Sdim Bldr.takeNodes(*I); 1089234353Sdim ExplodedNodeSet Dst3; 1090234353Sdim evalStore(Dst3, U, U, *I, state, loc, Result); 1091234353Sdim Bldr.addNodes(Dst3); 1092226586Sdim } 1093234353Sdim Dst.insert(Dst2); 1094226586Sdim} 1095