clang  9.0.0svn
ExprEngineC.cpp
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1 //=-- ExprEngineC.cpp - ExprEngine support for C expressions ----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines ExprEngine's support for C expressions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/ExprCXX.h"
14 #include "clang/AST/DeclCXX.h"
17 
18 using namespace clang;
19 using namespace ento;
20 using llvm::APSInt;
21 
22 /// Optionally conjure and return a symbol for offset when processing
23 /// an expression \p Expression.
24 /// If \p Other is a location, conjure a symbol for \p Symbol
25 /// (offset) if it is unknown so that memory arithmetic always
26 /// results in an ElementRegion.
27 /// \p Count The number of times the current basic block was visited.
29  SVal Symbol, SVal Other, Expr* Expression, SValBuilder &svalBuilder,
30  unsigned Count, const LocationContext *LCtx) {
31  QualType Ty = Expression->getType();
32  if (Other.getAs<Loc>() &&
34  Symbol.isUnknown()) {
35  return svalBuilder.conjureSymbolVal(Expression, LCtx, Ty, Count);
36  }
37  return Symbol;
38 }
39 
41  ExplodedNode *Pred,
42  ExplodedNodeSet &Dst) {
43 
44  Expr *LHS = B->getLHS()->IgnoreParens();
45  Expr *RHS = B->getRHS()->IgnoreParens();
46 
47  // FIXME: Prechecks eventually go in ::Visit().
48  ExplodedNodeSet CheckedSet;
49  ExplodedNodeSet Tmp2;
50  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, B, *this);
51 
52  // With both the LHS and RHS evaluated, process the operation itself.
53  for (ExplodedNodeSet::iterator it=CheckedSet.begin(), ei=CheckedSet.end();
54  it != ei; ++it) {
55 
56  ProgramStateRef state = (*it)->getState();
57  const LocationContext *LCtx = (*it)->getLocationContext();
58  SVal LeftV = state->getSVal(LHS, LCtx);
59  SVal RightV = state->getSVal(RHS, LCtx);
60 
62 
63  if (Op == BO_Assign) {
64  // EXPERIMENTAL: "Conjured" symbols.
65  // FIXME: Handle structs.
66  if (RightV.isUnknown()) {
67  unsigned Count = currBldrCtx->blockCount();
68  RightV = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx,
69  Count);
70  }
71  // Simulate the effects of a "store": bind the value of the RHS
72  // to the L-Value represented by the LHS.
73  SVal ExprVal = B->isGLValue() ? LeftV : RightV;
74  evalStore(Tmp2, B, LHS, *it, state->BindExpr(B, LCtx, ExprVal),
75  LeftV, RightV);
76  continue;
77  }
78 
79  if (!B->isAssignmentOp()) {
80  StmtNodeBuilder Bldr(*it, Tmp2, *currBldrCtx);
81 
82  if (B->isAdditiveOp()) {
83  // TODO: This can be removed after we enable history tracking with
84  // SymSymExpr.
85  unsigned Count = currBldrCtx->blockCount();
87  RightV, LeftV, RHS, svalBuilder, Count, LCtx);
89  LeftV, RightV, LHS, svalBuilder, Count, LCtx);
90  }
91 
92  // Although we don't yet model pointers-to-members, we do need to make
93  // sure that the members of temporaries have a valid 'this' pointer for
94  // other checks.
95  if (B->getOpcode() == BO_PtrMemD)
96  state = createTemporaryRegionIfNeeded(state, LCtx, LHS);
97 
98  // Process non-assignments except commas or short-circuited
99  // logical expressions (LAnd and LOr).
100  SVal Result = evalBinOp(state, Op, LeftV, RightV, B->getType());
101  if (!Result.isUnknown()) {
102  state = state->BindExpr(B, LCtx, Result);
103  }
104 
105  Bldr.generateNode(B, *it, state);
106  continue;
107  }
108 
109  assert (B->isCompoundAssignmentOp());
110 
111  switch (Op) {
112  default:
113  llvm_unreachable("Invalid opcode for compound assignment.");
114  case BO_MulAssign: Op = BO_Mul; break;
115  case BO_DivAssign: Op = BO_Div; break;
116  case BO_RemAssign: Op = BO_Rem; break;
117  case BO_AddAssign: Op = BO_Add; break;
118  case BO_SubAssign: Op = BO_Sub; break;
119  case BO_ShlAssign: Op = BO_Shl; break;
120  case BO_ShrAssign: Op = BO_Shr; break;
121  case BO_AndAssign: Op = BO_And; break;
122  case BO_XorAssign: Op = BO_Xor; break;
123  case BO_OrAssign: Op = BO_Or; break;
124  }
125 
126  // Perform a load (the LHS). This performs the checks for
127  // null dereferences, and so on.
128  ExplodedNodeSet Tmp;
129  SVal location = LeftV;
130  evalLoad(Tmp, B, LHS, *it, state, location);
131 
132  for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end(); I != E;
133  ++I) {
134 
135  state = (*I)->getState();
136  const LocationContext *LCtx = (*I)->getLocationContext();
137  SVal V = state->getSVal(LHS, LCtx);
138 
139  // Get the computation type.
140  QualType CTy =
141  cast<CompoundAssignOperator>(B)->getComputationResultType();
142  CTy = getContext().getCanonicalType(CTy);
143 
144  QualType CLHSTy =
145  cast<CompoundAssignOperator>(B)->getComputationLHSType();
146  CLHSTy = getContext().getCanonicalType(CLHSTy);
147 
149 
150  // Promote LHS.
151  V = svalBuilder.evalCast(V, CLHSTy, LTy);
152 
153  // Compute the result of the operation.
154  SVal Result = svalBuilder.evalCast(evalBinOp(state, Op, V, RightV, CTy),
155  B->getType(), CTy);
156 
157  // EXPERIMENTAL: "Conjured" symbols.
158  // FIXME: Handle structs.
159 
160  SVal LHSVal;
161 
162  if (Result.isUnknown()) {
163  // The symbolic value is actually for the type of the left-hand side
164  // expression, not the computation type, as this is the value the
165  // LValue on the LHS will bind to.
166  LHSVal = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx, LTy,
167  currBldrCtx->blockCount());
168  // However, we need to convert the symbol to the computation type.
169  Result = svalBuilder.evalCast(LHSVal, CTy, LTy);
170  }
171  else {
172  // The left-hand side may bind to a different value then the
173  // computation type.
174  LHSVal = svalBuilder.evalCast(Result, LTy, CTy);
175  }
176 
177  // In C++, assignment and compound assignment operators return an
178  // lvalue.
179  if (B->isGLValue())
180  state = state->BindExpr(B, LCtx, location);
181  else
182  state = state->BindExpr(B, LCtx, Result);
183 
184  evalStore(Tmp2, B, LHS, *I, state, location, LHSVal);
185  }
186  }
187 
188  // FIXME: postvisits eventually go in ::Visit()
189  getCheckerManager().runCheckersForPostStmt(Dst, Tmp2, B, *this);
190 }
191 
193  ExplodedNodeSet &Dst) {
194 
196 
197  const BlockDecl *BD = BE->getBlockDecl();
198  // Get the value of the block itself.
199  SVal V = svalBuilder.getBlockPointer(BD, T,
200  Pred->getLocationContext(),
201  currBldrCtx->blockCount());
202 
203  ProgramStateRef State = Pred->getState();
204 
205  // If we created a new MemRegion for the block, we should explicitly bind
206  // the captured variables.
207  if (const BlockDataRegion *BDR =
208  dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) {
209 
210  BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(),
211  E = BDR->referenced_vars_end();
212 
213  auto CI = BD->capture_begin();
214  auto CE = BD->capture_end();
215  for (; I != E; ++I) {
216  const VarRegion *capturedR = I.getCapturedRegion();
217  const VarRegion *originalR = I.getOriginalRegion();
218 
219  // If the capture had a copy expression, use the result of evaluating
220  // that expression, otherwise use the original value.
221  // We rely on the invariant that the block declaration's capture variables
222  // are a prefix of the BlockDataRegion's referenced vars (which may include
223  // referenced globals, etc.) to enable fast lookup of the capture for a
224  // given referenced var.
225  const Expr *copyExpr = nullptr;
226  if (CI != CE) {
227  assert(CI->getVariable() == capturedR->getDecl());
228  copyExpr = CI->getCopyExpr();
229  CI++;
230  }
231 
232  if (capturedR != originalR) {
233  SVal originalV;
234  const LocationContext *LCtx = Pred->getLocationContext();
235  if (copyExpr) {
236  originalV = State->getSVal(copyExpr, LCtx);
237  } else {
238  originalV = State->getSVal(loc::MemRegionVal(originalR));
239  }
240  State = State->bindLoc(loc::MemRegionVal(capturedR), originalV, LCtx);
241  }
242  }
243  }
244 
245  ExplodedNodeSet Tmp;
246  StmtNodeBuilder Bldr(Pred, Tmp, *currBldrCtx);
247  Bldr.generateNode(BE, Pred,
248  State->BindExpr(BE, Pred->getLocationContext(), V),
250 
251  // FIXME: Move all post/pre visits to ::Visit().
252  getCheckerManager().runCheckersForPostStmt(Dst, Tmp, BE, *this);
253 }
254 
256  ProgramStateRef state, const Expr* Ex, const LocationContext* LCtx,
257  QualType T, QualType ExTy, const CastExpr* CastE, StmtNodeBuilder& Bldr,
258  ExplodedNode* Pred) {
259  if (T->isLValueReferenceType()) {
260  assert(!CastE->getType()->isLValueReferenceType());
261  ExTy = getContext().getLValueReferenceType(ExTy);
262  } else if (T->isRValueReferenceType()) {
263  assert(!CastE->getType()->isRValueReferenceType());
264  ExTy = getContext().getRValueReferenceType(ExTy);
265  }
266  // Delegate to SValBuilder to process.
267  SVal OrigV = state->getSVal(Ex, LCtx);
268  SVal V = svalBuilder.evalCast(OrigV, T, ExTy);
269  // Negate the result if we're treating the boolean as a signed i1
270  if (CastE->getCastKind() == CK_BooleanToSignedIntegral)
271  V = evalMinus(V);
272  state = state->BindExpr(CastE, LCtx, V);
273  if (V.isUnknown() && !OrigV.isUnknown()) {
274  state = escapeValue(state, OrigV, PSK_EscapeOther);
275  }
276  Bldr.generateNode(CastE, Pred, state);
277 
278  return state;
279 }
280 
282  ProgramStateRef state, const LocationContext* LCtx, const CastExpr* CastE,
283  StmtNodeBuilder &Bldr, ExplodedNode* Pred) {
284  // Recover some path sensitivity by conjuring a new value.
285  QualType resultType = CastE->getType();
286  if (CastE->isGLValue())
287  resultType = getContext().getPointerType(resultType);
288  SVal result = svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx,
289  resultType,
290  currBldrCtx->blockCount());
291  state = state->BindExpr(CastE, LCtx, result);
292  Bldr.generateNode(CastE, Pred, state);
293 
294  return state;
295 }
296 
297 void ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex,
298  ExplodedNode *Pred, ExplodedNodeSet &Dst) {
299 
300  ExplodedNodeSet dstPreStmt;
301  getCheckerManager().runCheckersForPreStmt(dstPreStmt, Pred, CastE, *this);
302 
303  if (CastE->getCastKind() == CK_LValueToRValue) {
304  for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end();
305  I!=E; ++I) {
306  ExplodedNode *subExprNode = *I;
307  ProgramStateRef state = subExprNode->getState();
308  const LocationContext *LCtx = subExprNode->getLocationContext();
309  evalLoad(Dst, CastE, CastE, subExprNode, state, state->getSVal(Ex, LCtx));
310  }
311  return;
312  }
313 
314  // All other casts.
315  QualType T = CastE->getType();
316  QualType ExTy = Ex->getType();
317 
318  if (const ExplicitCastExpr *ExCast=dyn_cast_or_null<ExplicitCastExpr>(CastE))
319  T = ExCast->getTypeAsWritten();
320 
321  StmtNodeBuilder Bldr(dstPreStmt, Dst, *currBldrCtx);
322  for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end();
323  I != E; ++I) {
324 
325  Pred = *I;
326  ProgramStateRef state = Pred->getState();
327  const LocationContext *LCtx = Pred->getLocationContext();
328 
329  switch (CastE->getCastKind()) {
330  case CK_LValueToRValue:
331  llvm_unreachable("LValueToRValue casts handled earlier.");
332  case CK_ToVoid:
333  continue;
334  // The analyzer doesn't do anything special with these casts,
335  // since it understands retain/release semantics already.
336  case CK_ARCProduceObject:
337  case CK_ARCConsumeObject:
338  case CK_ARCReclaimReturnedObject:
339  case CK_ARCExtendBlockObject: // Fall-through.
340  case CK_CopyAndAutoreleaseBlockObject:
341  // The analyser can ignore atomic casts for now, although some future
342  // checkers may want to make certain that you're not modifying the same
343  // value through atomic and nonatomic pointers.
344  case CK_AtomicToNonAtomic:
345  case CK_NonAtomicToAtomic:
346  // True no-ops.
347  case CK_NoOp:
348  case CK_ConstructorConversion:
349  case CK_UserDefinedConversion:
350  case CK_FunctionToPointerDecay:
351  case CK_BuiltinFnToFnPtr: {
352  // Copy the SVal of Ex to CastE.
353  ProgramStateRef state = Pred->getState();
354  const LocationContext *LCtx = Pred->getLocationContext();
355  SVal V = state->getSVal(Ex, LCtx);
356  state = state->BindExpr(CastE, LCtx, V);
357  Bldr.generateNode(CastE, Pred, state);
358  continue;
359  }
360  case CK_MemberPointerToBoolean:
361  case CK_PointerToBoolean: {
362  SVal V = state->getSVal(Ex, LCtx);
363  auto PTMSV = V.getAs<nonloc::PointerToMember>();
364  if (PTMSV)
365  V = svalBuilder.makeTruthVal(!PTMSV->isNullMemberPointer(), ExTy);
366  if (V.isUndef() || PTMSV) {
367  state = state->BindExpr(CastE, LCtx, V);
368  Bldr.generateNode(CastE, Pred, state);
369  continue;
370  }
371  // Explicitly proceed with default handler for this case cascade.
372  state =
373  handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
374  continue;
375  }
376  case CK_Dependent:
377  case CK_ArrayToPointerDecay:
378  case CK_BitCast:
379  case CK_AddressSpaceConversion:
380  case CK_BooleanToSignedIntegral:
381  case CK_NullToPointer:
382  case CK_IntegralToPointer:
383  case CK_PointerToIntegral: {
384  SVal V = state->getSVal(Ex, LCtx);
385  if (V.getAs<nonloc::PointerToMember>()) {
386  state = state->BindExpr(CastE, LCtx, UnknownVal());
387  Bldr.generateNode(CastE, Pred, state);
388  continue;
389  }
390  // Explicitly proceed with default handler for this case cascade.
391  state =
392  handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
393  continue;
394  }
395  case CK_IntegralToBoolean:
396  case CK_IntegralToFloating:
397  case CK_FloatingToIntegral:
398  case CK_FloatingToBoolean:
399  case CK_FloatingCast:
400  case CK_FloatingRealToComplex:
401  case CK_FloatingComplexToReal:
402  case CK_FloatingComplexToBoolean:
403  case CK_FloatingComplexCast:
404  case CK_FloatingComplexToIntegralComplex:
405  case CK_IntegralRealToComplex:
406  case CK_IntegralComplexToReal:
407  case CK_IntegralComplexToBoolean:
408  case CK_IntegralComplexCast:
409  case CK_IntegralComplexToFloatingComplex:
410  case CK_CPointerToObjCPointerCast:
411  case CK_BlockPointerToObjCPointerCast:
412  case CK_AnyPointerToBlockPointerCast:
413  case CK_ObjCObjectLValueCast:
414  case CK_ZeroToOCLOpaqueType:
415  case CK_IntToOCLSampler:
416  case CK_LValueBitCast:
417  case CK_FixedPointCast:
418  case CK_FixedPointToBoolean: {
419  state =
420  handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
421  continue;
422  }
423  case CK_IntegralCast: {
424  // Delegate to SValBuilder to process.
425  SVal V = state->getSVal(Ex, LCtx);
426  V = svalBuilder.evalIntegralCast(state, V, T, ExTy);
427  state = state->BindExpr(CastE, LCtx, V);
428  Bldr.generateNode(CastE, Pred, state);
429  continue;
430  }
431  case CK_DerivedToBase:
432  case CK_UncheckedDerivedToBase: {
433  // For DerivedToBase cast, delegate to the store manager.
434  SVal val = state->getSVal(Ex, LCtx);
435  val = getStoreManager().evalDerivedToBase(val, CastE);
436  state = state->BindExpr(CastE, LCtx, val);
437  Bldr.generateNode(CastE, Pred, state);
438  continue;
439  }
440  // Handle C++ dyn_cast.
441  case CK_Dynamic: {
442  SVal val = state->getSVal(Ex, LCtx);
443 
444  // Compute the type of the result.
445  QualType resultType = CastE->getType();
446  if (CastE->isGLValue())
447  resultType = getContext().getPointerType(resultType);
448 
449  bool Failed = false;
450 
451  // Check if the value being cast evaluates to 0.
452  if (val.isZeroConstant())
453  Failed = true;
454  // Else, evaluate the cast.
455  else
456  val = getStoreManager().attemptDownCast(val, T, Failed);
457 
458  if (Failed) {
459  if (T->isReferenceType()) {
460  // A bad_cast exception is thrown if input value is a reference.
461  // Currently, we model this, by generating a sink.
462  Bldr.generateSink(CastE, Pred, state);
463  continue;
464  } else {
465  // If the cast fails on a pointer, bind to 0.
466  state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull());
467  }
468  } else {
469  // If we don't know if the cast succeeded, conjure a new symbol.
470  if (val.isUnknown()) {
471  DefinedOrUnknownSVal NewSym =
472  svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
473  currBldrCtx->blockCount());
474  state = state->BindExpr(CastE, LCtx, NewSym);
475  } else
476  // Else, bind to the derived region value.
477  state = state->BindExpr(CastE, LCtx, val);
478  }
479  Bldr.generateNode(CastE, Pred, state);
480  continue;
481  }
482  case CK_BaseToDerived: {
483  SVal val = state->getSVal(Ex, LCtx);
484  QualType resultType = CastE->getType();
485  if (CastE->isGLValue())
486  resultType = getContext().getPointerType(resultType);
487 
488  bool Failed = false;
489 
490  if (!val.isConstant()) {
491  val = getStoreManager().attemptDownCast(val, T, Failed);
492  }
493 
494  // Failed to cast or the result is unknown, fall back to conservative.
495  if (Failed || val.isUnknown()) {
496  val =
497  svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
498  currBldrCtx->blockCount());
499  }
500  state = state->BindExpr(CastE, LCtx, val);
501  Bldr.generateNode(CastE, Pred, state);
502  continue;
503  }
504  case CK_NullToMemberPointer: {
505  SVal V = svalBuilder.getMemberPointer(nullptr);
506  state = state->BindExpr(CastE, LCtx, V);
507  Bldr.generateNode(CastE, Pred, state);
508  continue;
509  }
510  case CK_DerivedToBaseMemberPointer:
511  case CK_BaseToDerivedMemberPointer:
512  case CK_ReinterpretMemberPointer: {
513  SVal V = state->getSVal(Ex, LCtx);
514  if (auto PTMSV = V.getAs<nonloc::PointerToMember>()) {
515  SVal CastedPTMSV = svalBuilder.makePointerToMember(
516  getBasicVals().accumCXXBase(
517  llvm::make_range<CastExpr::path_const_iterator>(
518  CastE->path_begin(), CastE->path_end()), *PTMSV));
519  state = state->BindExpr(CastE, LCtx, CastedPTMSV);
520  Bldr.generateNode(CastE, Pred, state);
521  continue;
522  }
523  // Explicitly proceed with default handler for this case cascade.
524  state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
525  continue;
526  }
527  // Various C++ casts that are not handled yet.
528  case CK_ToUnion:
529  case CK_VectorSplat: {
530  state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
531  continue;
532  }
533  }
534  }
535 }
536 
538  ExplodedNode *Pred,
539  ExplodedNodeSet &Dst) {
540  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
541 
542  ProgramStateRef State = Pred->getState();
543  const LocationContext *LCtx = Pred->getLocationContext();
544 
545  const Expr *Init = CL->getInitializer();
546  SVal V = State->getSVal(CL->getInitializer(), LCtx);
547 
548  if (isa<CXXConstructExpr>(Init) || isa<CXXStdInitializerListExpr>(Init)) {
549  // No work needed. Just pass the value up to this expression.
550  } else {
551  assert(isa<InitListExpr>(Init));
552  Loc CLLoc = State->getLValue(CL, LCtx);
553  State = State->bindLoc(CLLoc, V, LCtx);
554 
555  if (CL->isGLValue())
556  V = CLLoc;
557  }
558 
559  B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V));
560 }
561 
563  ExplodedNodeSet &Dst) {
564  // Assumption: The CFG has one DeclStmt per Decl.
565  const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin());
566 
567  if (!VD) {
568  //TODO:AZ: remove explicit insertion after refactoring is done.
569  Dst.insert(Pred);
570  return;
571  }
572 
573  // FIXME: all pre/post visits should eventually be handled by ::Visit().
574  ExplodedNodeSet dstPreVisit;
575  getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this);
576 
577  ExplodedNodeSet dstEvaluated;
578  StmtNodeBuilder B(dstPreVisit, dstEvaluated, *currBldrCtx);
579  for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end();
580  I!=E; ++I) {
581  ExplodedNode *N = *I;
583  const LocationContext *LC = N->getLocationContext();
584 
585  // Decls without InitExpr are not initialized explicitly.
586  if (const Expr *InitEx = VD->getInit()) {
587 
588  // Note in the state that the initialization has occurred.
589  ExplodedNode *UpdatedN = N;
590  SVal InitVal = state->getSVal(InitEx, LC);
591 
592  assert(DS->isSingleDecl());
593  if (getObjectUnderConstruction(state, DS, LC)) {
594  state = finishObjectConstruction(state, DS, LC);
595  // We constructed the object directly in the variable.
596  // No need to bind anything.
597  B.generateNode(DS, UpdatedN, state);
598  } else {
599  // Recover some path-sensitivity if a scalar value evaluated to
600  // UnknownVal.
601  if (InitVal.isUnknown()) {
602  QualType Ty = InitEx->getType();
603  if (InitEx->isGLValue()) {
604  Ty = getContext().getPointerType(Ty);
605  }
606 
607  InitVal = svalBuilder.conjureSymbolVal(nullptr, InitEx, LC, Ty,
608  currBldrCtx->blockCount());
609  }
610 
611 
612  B.takeNodes(UpdatedN);
613  ExplodedNodeSet Dst2;
614  evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true);
615  B.addNodes(Dst2);
616  }
617  }
618  else {
619  B.generateNode(DS, N, state);
620  }
621  }
622 
623  getCheckerManager().runCheckersForPostStmt(Dst, B.getResults(), DS, *this);
624 }
625 
627  ExplodedNodeSet &Dst) {
628  assert(B->getOpcode() == BO_LAnd ||
629  B->getOpcode() == BO_LOr);
630 
631  StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
632  ProgramStateRef state = Pred->getState();
633 
634  if (B->getType()->isVectorType()) {
635  // FIXME: We do not model vector arithmetic yet. When adding support for
636  // that, note that the CFG-based reasoning below does not apply, because
637  // logical operators on vectors are not short-circuit. Currently they are
638  // modeled as short-circuit in Clang CFG but this is incorrect.
639  // Do not set the value for the expression. It'd be UnknownVal by default.
640  Bldr.generateNode(B, Pred, state);
641  return;
642  }
643 
644  ExplodedNode *N = Pred;
645  while (!N->getLocation().getAs<BlockEntrance>()) {
646  ProgramPoint P = N->getLocation();
647  assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>());
648  (void) P;
649  assert(N->pred_size() == 1);
650  N = *N->pred_begin();
651  }
652  assert(N->pred_size() == 1);
653  N = *N->pred_begin();
654  BlockEdge BE = N->getLocation().castAs<BlockEdge>();
655  SVal X;
656 
657  // Determine the value of the expression by introspecting how we
658  // got this location in the CFG. This requires looking at the previous
659  // block we were in and what kind of control-flow transfer was involved.
660  const CFGBlock *SrcBlock = BE.getSrc();
661  // The only terminator (if there is one) that makes sense is a logical op.
662  CFGTerminator T = SrcBlock->getTerminator();
663  if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) {
664  (void) Term;
665  assert(Term->isLogicalOp());
666  assert(SrcBlock->succ_size() == 2);
667  // Did we take the true or false branch?
668  unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 1 : 0;
669  X = svalBuilder.makeIntVal(constant, B->getType());
670  }
671  else {
672  // If there is no terminator, by construction the last statement
673  // in SrcBlock is the value of the enclosing expression.
674  // However, we still need to constrain that value to be 0 or 1.
675  assert(!SrcBlock->empty());
676  CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>();
677  const Expr *RHS = cast<Expr>(Elem.getStmt());
678  SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext());
679 
680  if (RHSVal.isUndef()) {
681  X = RHSVal;
682  } else {
683  // We evaluate "RHSVal != 0" expression which result in 0 if the value is
684  // known to be false, 1 if the value is known to be true and a new symbol
685  // when the assumption is unknown.
687  X = evalBinOp(N->getState(), BO_NE,
688  svalBuilder.evalCast(RHSVal, B->getType(), RHS->getType()),
689  Zero, B->getType());
690  }
691  }
692  Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X));
693 }
694 
696  ExplodedNode *Pred,
697  ExplodedNodeSet &Dst) {
698  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
699 
700  ProgramStateRef state = Pred->getState();
701  const LocationContext *LCtx = Pred->getLocationContext();
703  unsigned NumInitElements = IE->getNumInits();
704 
705  if (!IE->isGLValue() &&
706  (T->isArrayType() || T->isRecordType() || T->isVectorType() ||
707  T->isAnyComplexType())) {
708  llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList();
709 
710  // Handle base case where the initializer has no elements.
711  // e.g: static int* myArray[] = {};
712  if (NumInitElements == 0) {
713  SVal V = svalBuilder.makeCompoundVal(T, vals);
714  B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
715  return;
716  }
717 
719  ei = IE->rend(); it != ei; ++it) {
720  SVal V = state->getSVal(cast<Expr>(*it), LCtx);
721  vals = getBasicVals().prependSVal(V, vals);
722  }
723 
724  B.generateNode(IE, Pred,
725  state->BindExpr(IE, LCtx,
726  svalBuilder.makeCompoundVal(T, vals)));
727  return;
728  }
729 
730  // Handle scalars: int{5} and int{} and GLvalues.
731  // Note, if the InitListExpr is a GLvalue, it means that there is an address
732  // representing it, so it must have a single init element.
733  assert(NumInitElements <= 1);
734 
735  SVal V;
736  if (NumInitElements == 0)
737  V = getSValBuilder().makeZeroVal(T);
738  else
739  V = state->getSVal(IE->getInit(0), LCtx);
740 
741  B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
742 }
743 
745  const Expr *L,
746  const Expr *R,
747  ExplodedNode *Pred,
748  ExplodedNodeSet &Dst) {
749  assert(L && R);
750 
751  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
752  ProgramStateRef state = Pred->getState();
753  const LocationContext *LCtx = Pred->getLocationContext();
754  const CFGBlock *SrcBlock = nullptr;
755 
756  // Find the predecessor block.
757  ProgramStateRef SrcState = state;
758  for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) {
759  ProgramPoint PP = N->getLocation();
760  if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) {
761  // If the state N has multiple predecessors P, it means that successors
762  // of P are all equivalent.
763  // In turn, that means that all nodes at P are equivalent in terms
764  // of observable behavior at N, and we can follow any of them.
765  // FIXME: a more robust solution which does not walk up the tree.
766  continue;
767  }
768  SrcBlock = PP.castAs<BlockEdge>().getSrc();
769  SrcState = N->getState();
770  break;
771  }
772 
773  assert(SrcBlock && "missing function entry");
774 
775  // Find the last expression in the predecessor block. That is the
776  // expression that is used for the value of the ternary expression.
777  bool hasValue = false;
778  SVal V;
779 
780  for (CFGElement CE : llvm::reverse(*SrcBlock)) {
781  if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) {
782  const Expr *ValEx = cast<Expr>(CS->getStmt());
783  ValEx = ValEx->IgnoreParens();
784 
785  // For GNU extension '?:' operator, the left hand side will be an
786  // OpaqueValueExpr, so get the underlying expression.
787  if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L))
788  L = OpaqueEx->getSourceExpr();
789 
790  // If the last expression in the predecessor block matches true or false
791  // subexpression, get its the value.
792  if (ValEx == L->IgnoreParens() || ValEx == R->IgnoreParens()) {
793  hasValue = true;
794  V = SrcState->getSVal(ValEx, LCtx);
795  }
796  break;
797  }
798  }
799 
800  if (!hasValue)
801  V = svalBuilder.conjureSymbolVal(nullptr, Ex, LCtx,
802  currBldrCtx->blockCount());
803 
804  // Generate a new node with the binding from the appropriate path.
805  B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true));
806 }
807 
808 void ExprEngine::
810  ExplodedNode *Pred, ExplodedNodeSet &Dst) {
811  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
812  Expr::EvalResult Result;
813  if (OOE->EvaluateAsInt(Result, getContext())) {
814  APSInt IV = Result.Val.getInt();
815  assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType()));
816  assert(OOE->getType()->isBuiltinType());
817  assert(OOE->getType()->getAs<BuiltinType>()->isInteger());
818  assert(IV.isSigned() == OOE->getType()->isSignedIntegerType());
819  SVal X = svalBuilder.makeIntVal(IV);
820  B.generateNode(OOE, Pred,
821  Pred->getState()->BindExpr(OOE, Pred->getLocationContext(),
822  X));
823  }
824  // FIXME: Handle the case where __builtin_offsetof is not a constant.
825 }
826 
827 
828 void ExprEngine::
830  ExplodedNode *Pred,
831  ExplodedNodeSet &Dst) {
832  // FIXME: Prechecks eventually go in ::Visit().
833  ExplodedNodeSet CheckedSet;
834  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, Ex, *this);
835 
836  ExplodedNodeSet EvalSet;
837  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
838 
839  QualType T = Ex->getTypeOfArgument();
840 
841  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
842  I != E; ++I) {
843  if (Ex->getKind() == UETT_SizeOf) {
844  if (!T->isIncompleteType() && !T->isConstantSizeType()) {
845  assert(T->isVariableArrayType() && "Unknown non-constant-sized type.");
846 
847  // FIXME: Add support for VLA type arguments and VLA expressions.
848  // When that happens, we should probably refactor VLASizeChecker's code.
849  continue;
850  } else if (T->getAs<ObjCObjectType>()) {
851  // Some code tries to take the sizeof an ObjCObjectType, relying that
852  // the compiler has laid out its representation. Just report Unknown
853  // for these.
854  continue;
855  }
856  }
857 
858  APSInt Value = Ex->EvaluateKnownConstInt(getContext());
859  CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue());
860 
861  ProgramStateRef state = (*I)->getState();
862  state = state->BindExpr(Ex, (*I)->getLocationContext(),
863  svalBuilder.makeIntVal(amt.getQuantity(),
864  Ex->getType()));
865  Bldr.generateNode(Ex, *I, state);
866  }
867 
868  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, Ex, *this);
869 }
870 
872  const UnaryOperator *U,
873  StmtNodeBuilder &Bldr) {
874  // FIXME: We can probably just have some magic in Environment::getSVal()
875  // that propagates values, instead of creating a new node here.
876  //
877  // Unary "+" is a no-op, similar to a parentheses. We still have places
878  // where it may be a block-level expression, so we need to
879  // generate an extra node that just propagates the value of the
880  // subexpression.
881  const Expr *Ex = U->getSubExpr()->IgnoreParens();
882  ProgramStateRef state = (*I)->getState();
883  const LocationContext *LCtx = (*I)->getLocationContext();
884  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
885  state->getSVal(Ex, LCtx)));
886 }
887 
889  ExplodedNodeSet &Dst) {
890  // FIXME: Prechecks eventually go in ::Visit().
891  ExplodedNodeSet CheckedSet;
892  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, U, *this);
893 
894  ExplodedNodeSet EvalSet;
895  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
896 
897  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
898  I != E; ++I) {
899  switch (U->getOpcode()) {
900  default: {
901  Bldr.takeNodes(*I);
902  ExplodedNodeSet Tmp;
904  Bldr.addNodes(Tmp);
905  break;
906  }
907  case UO_Real: {
908  const Expr *Ex = U->getSubExpr()->IgnoreParens();
909 
910  // FIXME: We don't have complex SValues yet.
911  if (Ex->getType()->isAnyComplexType()) {
912  // Just report "Unknown."
913  break;
914  }
915 
916  // For all other types, UO_Real is an identity operation.
917  assert (U->getType() == Ex->getType());
918  ProgramStateRef state = (*I)->getState();
919  const LocationContext *LCtx = (*I)->getLocationContext();
920  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
921  state->getSVal(Ex, LCtx)));
922  break;
923  }
924 
925  case UO_Imag: {
926  const Expr *Ex = U->getSubExpr()->IgnoreParens();
927  // FIXME: We don't have complex SValues yet.
928  if (Ex->getType()->isAnyComplexType()) {
929  // Just report "Unknown."
930  break;
931  }
932  // For all other types, UO_Imag returns 0.
933  ProgramStateRef state = (*I)->getState();
934  const LocationContext *LCtx = (*I)->getLocationContext();
935  SVal X = svalBuilder.makeZeroVal(Ex->getType());
936  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, X));
937  break;
938  }
939 
940  case UO_AddrOf: {
941  // Process pointer-to-member address operation.
942  const Expr *Ex = U->getSubExpr()->IgnoreParens();
943  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex)) {
944  const ValueDecl *VD = DRE->getDecl();
945 
946  if (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD)) {
947  ProgramStateRef State = (*I)->getState();
948  const LocationContext *LCtx = (*I)->getLocationContext();
949  SVal SV = svalBuilder.getMemberPointer(cast<DeclaratorDecl>(VD));
950  Bldr.generateNode(U, *I, State->BindExpr(U, LCtx, SV));
951  break;
952  }
953  }
954  // Explicitly proceed with default handler for this case cascade.
955  handleUOExtension(I, U, Bldr);
956  break;
957  }
958  case UO_Plus:
959  assert(!U->isGLValue());
960  LLVM_FALLTHROUGH;
961  case UO_Deref:
962  case UO_Extension: {
963  handleUOExtension(I, U, Bldr);
964  break;
965  }
966 
967  case UO_LNot:
968  case UO_Minus:
969  case UO_Not: {
970  assert (!U->isGLValue());
971  const Expr *Ex = U->getSubExpr()->IgnoreParens();
972  ProgramStateRef state = (*I)->getState();
973  const LocationContext *LCtx = (*I)->getLocationContext();
974 
975  // Get the value of the subexpression.
976  SVal V = state->getSVal(Ex, LCtx);
977 
978  if (V.isUnknownOrUndef()) {
979  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V));
980  break;
981  }
982 
983  switch (U->getOpcode()) {
984  default:
985  llvm_unreachable("Invalid Opcode.");
986  case UO_Not:
987  // FIXME: Do we need to handle promotions?
988  state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>()));
989  break;
990  case UO_Minus:
991  // FIXME: Do we need to handle promotions?
992  state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>()));
993  break;
994  case UO_LNot:
995  // C99 6.5.3.3: "The expression !E is equivalent to (0==E)."
996  //
997  // Note: technically we do "E == 0", but this is the same in the
998  // transfer functions as "0 == E".
999  SVal Result;
1000  if (Optional<Loc> LV = V.getAs<Loc>()) {
1001  Loc X = svalBuilder.makeNullWithType(Ex->getType());
1002  Result = evalBinOp(state, BO_EQ, *LV, X, U->getType());
1003  } else if (Ex->getType()->isFloatingType()) {
1004  // FIXME: handle floating point types.
1005  Result = UnknownVal();
1006  } else {
1007  nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType()));
1008  Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X,
1009  U->getType());
1010  }
1011 
1012  state = state->BindExpr(U, LCtx, Result);
1013  break;
1014  }
1015  Bldr.generateNode(U, *I, state);
1016  break;
1017  }
1018  }
1019  }
1020 
1021  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, U, *this);
1022 }
1023 
1025  ExplodedNode *Pred,
1026  ExplodedNodeSet &Dst) {
1027  // Handle ++ and -- (both pre- and post-increment).
1028  assert (U->isIncrementDecrementOp());
1029  const Expr *Ex = U->getSubExpr()->IgnoreParens();
1030 
1031  const LocationContext *LCtx = Pred->getLocationContext();
1032  ProgramStateRef state = Pred->getState();
1033  SVal loc = state->getSVal(Ex, LCtx);
1034 
1035  // Perform a load.
1036  ExplodedNodeSet Tmp;
1037  evalLoad(Tmp, U, Ex, Pred, state, loc);
1038 
1039  ExplodedNodeSet Dst2;
1040  StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx);
1041  for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;++I) {
1042 
1043  state = (*I)->getState();
1044  assert(LCtx == (*I)->getLocationContext());
1045  SVal V2_untested = state->getSVal(Ex, LCtx);
1046 
1047  // Propagate unknown and undefined values.
1048  if (V2_untested.isUnknownOrUndef()) {
1049  state = state->BindExpr(U, LCtx, V2_untested);
1050 
1051  // Perform the store, so that the uninitialized value detection happens.
1052  Bldr.takeNodes(*I);
1053  ExplodedNodeSet Dst3;
1054  evalStore(Dst3, U, Ex, *I, state, loc, V2_untested);
1055  Bldr.addNodes(Dst3);
1056 
1057  continue;
1058  }
1059  DefinedSVal V2 = V2_untested.castAs<DefinedSVal>();
1060 
1061  // Handle all other values.
1062  BinaryOperator::Opcode Op = U->isIncrementOp() ? BO_Add : BO_Sub;
1063 
1064  // If the UnaryOperator has non-location type, use its type to create the
1065  // constant value. If the UnaryOperator has location type, create the
1066  // constant with int type and pointer width.
1067  SVal RHS;
1068  SVal Result;
1069 
1070  if (U->getType()->isAnyPointerType())
1071  RHS = svalBuilder.makeArrayIndex(1);
1072  else if (U->getType()->isIntegralOrEnumerationType())
1073  RHS = svalBuilder.makeIntVal(1, U->getType());
1074  else
1075  RHS = UnknownVal();
1076 
1077  // The use of an operand of type bool with the ++ operators is deprecated
1078  // but valid until C++17. And if the operand of the ++ operator is of type
1079  // bool, it is set to true until C++17. Note that for '_Bool', it is also
1080  // set to true when it encounters ++ operator.
1081  if (U->getType()->isBooleanType() && U->isIncrementOp())
1082  Result = svalBuilder.makeTruthVal(true, U->getType());
1083  else
1084  Result = evalBinOp(state, Op, V2, RHS, U->getType());
1085 
1086  // Conjure a new symbol if necessary to recover precision.
1087  if (Result.isUnknown()){
1088  DefinedOrUnknownSVal SymVal =
1089  svalBuilder.conjureSymbolVal(nullptr, U, LCtx,
1090  currBldrCtx->blockCount());
1091  Result = SymVal;
1092 
1093  // If the value is a location, ++/-- should always preserve
1094  // non-nullness. Check if the original value was non-null, and if so
1095  // propagate that constraint.
1096  if (Loc::isLocType(U->getType())) {
1097  DefinedOrUnknownSVal Constraint =
1098  svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType()));
1099 
1100  if (!state->assume(Constraint, true)) {
1101  // It isn't feasible for the original value to be null.
1102  // Propagate this constraint.
1103  Constraint = svalBuilder.evalEQ(state, SymVal,
1104  svalBuilder.makeZeroVal(U->getType()));
1105 
1106  state = state->assume(Constraint, false);
1107  assert(state);
1108  }
1109  }
1110  }
1111 
1112  // Since the lvalue-to-rvalue conversion is explicit in the AST,
1113  // we bind an l-value if the operator is prefix and an lvalue (in C++).
1114  if (U->isGLValue())
1115  state = state->BindExpr(U, LCtx, loc);
1116  else
1117  state = state->BindExpr(U, LCtx, U->isPostfix() ? V2 : Result);
1118 
1119  // Perform the store.
1120  Bldr.takeNodes(*I);
1121  ExplodedNodeSet Dst3;
1122  evalStore(Dst3, U, Ex, *I, state, loc, Result);
1123  Bldr.addNodes(Dst3);
1124  }
1125  Dst.insert(Dst2);
1126 }
SVal attemptDownCast(SVal Base, QualType DerivedPtrType, bool &Failed)
Attempts to do a down cast.
Definition: Store.cpp:314
const BlockDecl * getBlockDecl() const
Definition: Expr.h:5395
nonloc::ConcreteInt makeIntVal(const IntegerLiteral *integer)
Definition: SValBuilder.h:278
DefinedSVal getBlockPointer(const BlockDecl *block, CanQualType locTy, const LocationContext *locContext, unsigned blockCount)
reverse_iterator rbegin()
Definition: Expr.h:4416
SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast)
Evaluates a chain of derived-to-base casts through the path specified in Cast.
Definition: Store.cpp:248
bool empty() const
Definition: CFG.h:713
A (possibly-)qualified type.
Definition: Type.h:634
bool isArrayType() const
Definition: Type.h:6350
succ_iterator succ_begin()
Definition: CFG.h:750
capture_const_iterator capture_begin() const
Definition: Decl.h:3986
const Expr * getInit(unsigned Init) const
Definition: Expr.h:4259
unsigned blockCount() const
Returns the number of times the current basic block has been visited on the exploded graph path...
Definition: CoreEngine.h:211
bool EvaluateAsInt(EvalResult &Result, const ASTContext &Ctx, SideEffectsKind AllowSideEffects=SE_NoSideEffects) const
EvaluateAsInt - Return true if this is a constant which we can fold and convert to an integer...
This builder class is useful for generating nodes that resulted from visiting a statement.
Definition: CoreEngine.h:369
bool isRecordType() const
Definition: Type.h:6374
const CFGBlock * getSrc() const
Definition: ProgramPoint.h:512
QualType getLValueReferenceType(QualType T, bool SpelledAsLValue=true) const
Return the uniqued reference to the type for an lvalue reference to the specified type...
Opcode getOpcode() const
Definition: Expr.h:3348
StringRef P
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, NonLoc L, NonLoc R, QualType T)
Definition: ExprEngine.h:581
Represents a point after we ran remove dead bindings BEFORE processing the given statement.
Definition: ProgramPoint.h:474
T castAs() const
Convert to the specified CFGElement type, asserting that this CFGElement is of the desired type...
Definition: CFG.h:98
const ProgramStateRef & getState() const
SVal evalCast(SVal val, QualType castTy, QualType originalType)
Value representing integer constant.
Definition: SVals.h:376
capture_const_iterator capture_end() const
Definition: Decl.h:3987
unsigned succ_size() const
Definition: CFG.h:768
void VisitUnaryOperator(const UnaryOperator *B, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitUnaryOperator - Transfer function logic for unary operators.
void takeNodes(const ExplodedNodeSet &S)
Definition: CoreEngine.h:320
void handleUOExtension(ExplodedNodeSet::iterator I, const UnaryOperator *U, StmtNodeBuilder &Bldr)
Represents a variable declaration or definition.
Definition: Decl.h:812
CompoundLiteralExpr - [C99 6.5.2.5].
Definition: Expr.h:2963
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6761
NonLoc makeArrayIndex(uint64_t idx)
Definition: SValBuilder.h:272
static Optional< SVal > getObjectUnderConstruction(ProgramStateRef State, const ConstructionContextItem &Item, const LocationContext *LC)
By looking at a certain item that may be potentially part of an object&#39;s ConstructionContext, retrieve such object&#39;s location.
Definition: ExprEngine.cpp:462
void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val, const ProgramPointTag *tag=nullptr)
evalStore - Handle the semantics of a store via an assignment.
static bool isAssignmentOp(Opcode Opc)
Definition: Expr.h:3436
Defines the clang::Expr interface and subclasses for C++ expressions.
bool isVariableArrayType() const
Definition: Type.h:6362
InitExprsTy::const_reverse_iterator const_reverse_iterator
Definition: Expr.h:4410
Represents a class type in Objective C.
Definition: Type.h:5543
Value representing pointer-to-member.
Definition: SVals.h:521
LineState State
SVal evalIntegralCast(ProgramStateRef state, SVal val, QualType castTy, QualType originalType)
Loc makeNullWithType(QualType type)
Create NULL pointer, with proper pointer bit-width for given address space.
Definition: SValBuilder.h:345
static bool isIncrementDecrementOp(Opcode Op)
Definition: Expr.h:2002
bool isReferenceType() const
Definition: Type.h:6313
i32 captured_struct **param SharedsTy A type which contains references the shared variables *param Shareds Context with the list of shared variables from the p *TaskFunction *param Data Additional data for task generation like final * state
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6657
llvm::ImmutableList< SVal > prependSVal(SVal X, llvm::ImmutableList< SVal > L)
static bool isLocType(QualType T)
Definition: SVals.h:326
bool isGLValue() const
Definition: Expr.h:254
Describes an C or C++ initializer list.
Definition: Expr.h:4211
void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitOffsetOfExpr - Transfer function for offsetof.
BinaryOperatorKind
BlockDataRegion - A region that represents a block instance.
Definition: MemRegion.h:672
ExplodedNode * generateSink(const Stmt *S, ExplodedNode *Pred, ProgramStateRef St, const ProgramPointTag *tag=nullptr, ProgramPoint::Kind K=ProgramPoint::PostStmtKind)
Definition: CoreEngine.h:408
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
APValue Val
Val - This is the value the expression can be folded to.
Definition: Expr.h:575
path_iterator path_begin()
Definition: Expr.h:3108
const LocationContext * getLocationContext() const
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3313
bool isUnknown() const
Definition: SVals.h:136
NonLoc makePointerToMember(const DeclaratorDecl *DD)
Definition: SValBuilder.h:260
static bool isPostfix(Opcode Op)
isPostfix - Return true if this is a postfix operation, like x++.
Definition: Expr.h:1976
bool isRValueReferenceType() const
Definition: Type.h:6321
NonLoc makeCompoundVal(QualType type, llvm::ImmutableList< SVal > vals)
Definition: SValBuilder.h:250
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3036
SVal evalComplement(SVal X)
Definition: ExprEngine.h:560
void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitDeclStmt - Transfer function logic for DeclStmts.
unsigned pred_size() const
bool isConstant() const
Definition: SVals.cpp:221
void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, SVal location, SVal Val, bool atDeclInit=false, const ProgramPoint *PP=nullptr)
evalBind - Handle the semantics of binding a value to a specific location.
CheckerManager & getCheckerManager() const
Definition: ExprEngine.h:189
void VisitLogicalExpr(const BinaryOperator *B, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitLogicalExpr - Transfer function logic for &#39;&&&#39;, &#39;||&#39;.
UnaryExprOrTypeTraitExpr - expression with either a type or (unevaluated) expression operand...
Definition: Expr.h:2255
Represents a single basic block in a source-level CFG.
Definition: CFG.h:551
void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, ExplodedNodeSet &Dst)
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
llvm::APSInt EvaluateKnownConstInt(const ASTContext &Ctx, SmallVectorImpl< PartialDiagnosticAt > *Diag=nullptr) const
EvaluateKnownConstInt - Call EvaluateAsRValue and return the folded integer.
void runCheckersForPostStmt(ExplodedNodeSet &Dst, const ExplodedNodeSet &Src, const Stmt *S, ExprEngine &Eng, bool wasInlined=false)
Run checkers for post-visiting Stmts.
DefinedOrUnknownSVal makeZeroVal(QualType type)
Construct an SVal representing &#39;0&#39; for the specified type.
Definition: SValBuilder.cpp:52
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3857
Represent the declaration of a variable (in which case it is an lvalue) a function (in which case it ...
Definition: Decl.h:636
This represents one expression.
Definition: Expr.h:108
static SVal conjureOffsetSymbolOnLocation(SVal Symbol, SVal Other, Expr *Expression, SValBuilder &svalBuilder, unsigned Count, const LocationContext *LCtx)
Optionally conjure and return a symbol for offset when processing an expression Expression.
Definition: ExprEngineC.cpp:28
void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitCast - Transfer function logic for all casts (implicit and explicit).
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5381
unsigned getNumInits() const
Definition: Expr.h:4241
const ExplodedNodeSet & getResults()
Definition: CoreEngine.h:297
bool isAnyComplexType() const
Definition: Type.h:6382
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
static SVal getValue(SVal val, SValBuilder &svalBuilder)
bool isSignedIntegerType() const
Return true if this is an integer type that is signed, according to C99 6.2.5p4 [char, signed char, short, int, long..], or an enum decl which has a signed representation.
Definition: Type.cpp:1866
const CFGBlock * getDst() const
Definition: ProgramPoint.h:516
QualType getType() const
Definition: Expr.h:130
QualType getTypeOfArgument() const
Gets the argument type, or the type of the argument expression, whichever is appropriate.
Definition: Expr.h:2318
The reason for pointer escape is unknown.
ASTContext & getContext() const
getContext - Return the ASTContext associated with this analysis.
Definition: ExprEngine.h:181
UnaryOperator - This represents the unary-expression&#39;s (except sizeof and alignof), the postinc/postdec operators from postfix-expression, and various extensions.
Definition: Expr.h:1929
void evalLoad(ExplodedNodeSet &Dst, const Expr *NodeEx, const Expr *BoundExpr, ExplodedNode *Pred, ProgramStateRef St, SVal location, const ProgramPointTag *tag=nullptr, QualType LoadTy=QualType())
Simulate a read of the result of Ex.
reverse_iterator rbegin()
Definition: CFG.h:707
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:111
const VarDecl * getDecl() const
Definition: MemRegion.h:949
CFGTerminator getTerminator()
Definition: CFG.h:839
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:978
bool isBuiltinType() const
Helper methods to distinguish type categories.
Definition: Type.h:6370
void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitGuardedExpr - Transfer function logic for ?, __builtin_choose.
DefinedOrUnknownSVal conjureSymbolVal(const void *symbolTag, const Expr *expr, const LocationContext *LCtx, unsigned count)
Create a new symbol with a unique &#39;name&#39;.
Expr * getSubExpr() const
Definition: Expr.h:1959
T castAs() const
Convert to the specified ProgramPoint type, asserting that this ProgramPoint is of the desired type...
Definition: ProgramPoint.h:141
CastKind getCastKind() const
Definition: Expr.h:3082
const MemRegion * getAsRegion() const
Definition: SVals.cpp:150
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
Definition: Stmt.h:1139
void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitCompoundLiteralExpr - Transfer function logic for compound literals.
ProgramStateRef handleLVectorSplat(ProgramStateRef state, const LocationContext *LCtx, const CastExpr *CastE, StmtNodeBuilder &Bldr, ExplodedNode *Pred)
ProgramPoint getLocation() const
getLocation - Returns the edge associated with the given node.
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:75
UnaryExprOrTypeTrait getKind() const
Definition: Expr.h:2286
decl_iterator decl_begin()
Definition: Stmt.h:1188
void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
bool isAnyPointerType() const
Definition: Type.h:6305
BasicValueFactory & getBasicVals()
Definition: ExprEngine.h:392
void runCheckersForPreStmt(ExplodedNodeSet &Dst, const ExplodedNodeSet &Src, const Stmt *S, ExprEngine &Eng)
Run checkers for pre-visiting Stmts.
bool isVectorType() const
Definition: Type.h:6386
void insert(const ExplodedNodeSet &S)
const Expr * getInitializer() const
Definition: Expr.h:2989
Expr * getLHS() const
Definition: Expr.h:3353
Dataflow Directional Tag Classes.
void VisitIncrementDecrementOperator(const UnaryOperator *U, ExplodedNode *Pred, ExplodedNodeSet &Dst)
Handle ++ and – (both pre- and post-increment).
SValBuilder & getSValBuilder()
Definition: ExprEngine.h:193
EvalResult is a struct with detailed info about an evaluated expression.
Definition: Expr.h:573
void addNodes(const ExplodedNodeSet &S)
Definition: CoreEngine.h:326
StoreManager & getStoreManager()
Definition: ExprEngine.h:385
bool isZeroConstant() const
Definition: SVals.cpp:233
const Expr * getInit() const
Definition: Decl.h:1219
bool isBooleanType() const
Definition: Type.h:6670
SVal evalEQ(ProgramStateRef state, SVal lhs, SVal rhs)
ExplicitCastExpr - An explicit cast written in the source code.
Definition: Expr.h:3216
bool isSingleDecl() const
isSingleDecl - This method returns true if this DeclStmt refers to a single Decl. ...
Definition: Stmt.h:1152
Stmt * getStmt()
Definition: CFG.h:509
path_iterator path_end()
Definition: Expr.h:3109
ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex, const LocationContext *LCtx, QualType T, QualType ExTy, const CastExpr *CastE, StmtNodeBuilder &Bldr, ExplodedNode *Pred)
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
Definition: SVals.h:103
bool isConstantSizeType() const
Return true if this is not a variable sized type, according to the rules of C99 6.7.5p3.
Definition: Type.cpp:2043
SVal evalMinus(SVal X)
Definition: ExprEngine.h:556
DefinedSVal getMemberPointer(const DeclaratorDecl *DD)
Opcode getOpcode() const
Definition: Expr.h:1954
static bool isAdditiveOp(Opcode Opc)
Definition: Expr.h:3389
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2072
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types...
Definition: Type.cpp:2053
static bool isIncrementOp(Opcode Op)
Definition: Expr.h:1988
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2266
bool isLValueReferenceType() const
Definition: Type.h:6317
reverse_iterator rend()
Definition: Expr.h:4418
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13978
void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitBlockExpr - Transfer function logic for BlockExprs.
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
static bool isCompoundAssignmentOp(Opcode Opc)
Definition: Expr.h:3441
QualType getRValueReferenceType(QualType T) const
Return the uniqued reference to the type for an rvalue reference to the specified type...
pred_iterator pred_begin()
Represents a top-level expression in a basic block.
Definition: CFG.h:55
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
This class is used for builtin types like &#39;int&#39;.
Definition: Type.h:2396
Represents CFGBlock terminator statement.
Definition: CFG.h:501
ExplodedNode * generateNode(const Stmt *S, ExplodedNode *Pred, ProgramStateRef St, const ProgramPointTag *tag=nullptr, ProgramPoint::Kind K=ProgramPoint::PostStmtKind)
Definition: CoreEngine.h:398
bool isUndef() const
Definition: SVals.h:140
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1074
Expr * getRHS() const
Definition: Expr.h:3355
nonloc::ConcreteInt makeTruthVal(bool b, QualType type)
Definition: SValBuilder.h:334
ProgramStateRef escapeValue(ProgramStateRef State, SVal V, PointerEscapeKind K) const
A simple wrapper when you only need to notify checkers of pointer-escape of a single value...
Optional< T > getAs() const
Convert to the specified ProgramPoint type, returning None if this ProgramPoint is not of the desired...
Definition: ProgramPoint.h:152
OffsetOfExpr - [C99 7.17] - This represents an expression of the form offsetof(record-type, member-designator).
Definition: Expr.h:2150
void VisitBinaryOperator(const BinaryOperator *B, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitBinaryOperator - Transfer function logic for binary operators.
Definition: ExprEngineC.cpp:40
APSInt & getInt()
Definition: APValue.h:257
bool isUnknownOrUndef() const
Definition: SVals.h:144
llvm::ImmutableList< SVal > getEmptySValList()
Expr * IgnoreParens() LLVM_READONLY
Skip past any parentheses which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2715