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_IntegralToPointer:
382  case CK_PointerToIntegral: {
383  SVal V = state->getSVal(Ex, LCtx);
384  if (V.getAs<nonloc::PointerToMember>()) {
385  state = state->BindExpr(CastE, LCtx, UnknownVal());
386  Bldr.generateNode(CastE, Pred, state);
387  continue;
388  }
389  // Explicitly proceed with default handler for this case cascade.
390  state =
391  handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
392  continue;
393  }
394  case CK_IntegralToBoolean:
395  case CK_IntegralToFloating:
396  case CK_FloatingToIntegral:
397  case CK_FloatingToBoolean:
398  case CK_FloatingCast:
399  case CK_FloatingRealToComplex:
400  case CK_FloatingComplexToReal:
401  case CK_FloatingComplexToBoolean:
402  case CK_FloatingComplexCast:
403  case CK_FloatingComplexToIntegralComplex:
404  case CK_IntegralRealToComplex:
405  case CK_IntegralComplexToReal:
406  case CK_IntegralComplexToBoolean:
407  case CK_IntegralComplexCast:
408  case CK_IntegralComplexToFloatingComplex:
409  case CK_CPointerToObjCPointerCast:
410  case CK_BlockPointerToObjCPointerCast:
411  case CK_AnyPointerToBlockPointerCast:
412  case CK_ObjCObjectLValueCast:
413  case CK_ZeroToOCLOpaqueType:
414  case CK_IntToOCLSampler:
415  case CK_LValueBitCast:
416  case CK_FixedPointCast:
417  case CK_FixedPointToBoolean:
418  case CK_FixedPointToIntegral:
419  case CK_IntegralToFixedPoint: {
420  state =
421  handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
422  continue;
423  }
424  case CK_IntegralCast: {
425  // Delegate to SValBuilder to process.
426  SVal V = state->getSVal(Ex, LCtx);
427  V = svalBuilder.evalIntegralCast(state, V, T, ExTy);
428  state = state->BindExpr(CastE, LCtx, V);
429  Bldr.generateNode(CastE, Pred, state);
430  continue;
431  }
432  case CK_DerivedToBase:
433  case CK_UncheckedDerivedToBase: {
434  // For DerivedToBase cast, delegate to the store manager.
435  SVal val = state->getSVal(Ex, LCtx);
436  val = getStoreManager().evalDerivedToBase(val, CastE);
437  state = state->BindExpr(CastE, LCtx, val);
438  Bldr.generateNode(CastE, Pred, state);
439  continue;
440  }
441  // Handle C++ dyn_cast.
442  case CK_Dynamic: {
443  SVal val = state->getSVal(Ex, LCtx);
444 
445  // Compute the type of the result.
446  QualType resultType = CastE->getType();
447  if (CastE->isGLValue())
448  resultType = getContext().getPointerType(resultType);
449 
450  bool Failed = false;
451 
452  // Check if the value being cast evaluates to 0.
453  if (val.isZeroConstant())
454  Failed = true;
455  // Else, evaluate the cast.
456  else
457  val = getStoreManager().attemptDownCast(val, T, Failed);
458 
459  if (Failed) {
460  if (T->isReferenceType()) {
461  // A bad_cast exception is thrown if input value is a reference.
462  // Currently, we model this, by generating a sink.
463  Bldr.generateSink(CastE, Pred, state);
464  continue;
465  } else {
466  // If the cast fails on a pointer, bind to 0.
467  state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull());
468  }
469  } else {
470  // If we don't know if the cast succeeded, conjure a new symbol.
471  if (val.isUnknown()) {
472  DefinedOrUnknownSVal NewSym =
473  svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
474  currBldrCtx->blockCount());
475  state = state->BindExpr(CastE, LCtx, NewSym);
476  } else
477  // Else, bind to the derived region value.
478  state = state->BindExpr(CastE, LCtx, val);
479  }
480  Bldr.generateNode(CastE, Pred, state);
481  continue;
482  }
483  case CK_BaseToDerived: {
484  SVal val = state->getSVal(Ex, LCtx);
485  QualType resultType = CastE->getType();
486  if (CastE->isGLValue())
487  resultType = getContext().getPointerType(resultType);
488 
489  bool Failed = false;
490 
491  if (!val.isConstant()) {
492  val = getStoreManager().attemptDownCast(val, T, Failed);
493  }
494 
495  // Failed to cast or the result is unknown, fall back to conservative.
496  if (Failed || val.isUnknown()) {
497  val =
498  svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
499  currBldrCtx->blockCount());
500  }
501  state = state->BindExpr(CastE, LCtx, val);
502  Bldr.generateNode(CastE, Pred, state);
503  continue;
504  }
505  case CK_NullToPointer: {
506  SVal V = svalBuilder.makeNull();
507  state = state->BindExpr(CastE, LCtx, V);
508  Bldr.generateNode(CastE, Pred, state);
509  continue;
510  }
511  case CK_NullToMemberPointer: {
512  SVal V = svalBuilder.getMemberPointer(nullptr);
513  state = state->BindExpr(CastE, LCtx, V);
514  Bldr.generateNode(CastE, Pred, state);
515  continue;
516  }
517  case CK_DerivedToBaseMemberPointer:
518  case CK_BaseToDerivedMemberPointer:
519  case CK_ReinterpretMemberPointer: {
520  SVal V = state->getSVal(Ex, LCtx);
521  if (auto PTMSV = V.getAs<nonloc::PointerToMember>()) {
522  SVal CastedPTMSV = svalBuilder.makePointerToMember(
523  getBasicVals().accumCXXBase(
524  llvm::make_range<CastExpr::path_const_iterator>(
525  CastE->path_begin(), CastE->path_end()), *PTMSV));
526  state = state->BindExpr(CastE, LCtx, CastedPTMSV);
527  Bldr.generateNode(CastE, Pred, state);
528  continue;
529  }
530  // Explicitly proceed with default handler for this case cascade.
531  state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
532  continue;
533  }
534  // Various C++ casts that are not handled yet.
535  case CK_ToUnion:
536  case CK_VectorSplat: {
537  state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
538  continue;
539  }
540  }
541  }
542 }
543 
545  ExplodedNode *Pred,
546  ExplodedNodeSet &Dst) {
547  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
548 
549  ProgramStateRef State = Pred->getState();
550  const LocationContext *LCtx = Pred->getLocationContext();
551 
552  const Expr *Init = CL->getInitializer();
553  SVal V = State->getSVal(CL->getInitializer(), LCtx);
554 
555  if (isa<CXXConstructExpr>(Init) || isa<CXXStdInitializerListExpr>(Init)) {
556  // No work needed. Just pass the value up to this expression.
557  } else {
558  assert(isa<InitListExpr>(Init));
559  Loc CLLoc = State->getLValue(CL, LCtx);
560  State = State->bindLoc(CLLoc, V, LCtx);
561 
562  if (CL->isGLValue())
563  V = CLLoc;
564  }
565 
566  B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V));
567 }
568 
570  ExplodedNodeSet &Dst) {
571  // Assumption: The CFG has one DeclStmt per Decl.
572  const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin());
573 
574  if (!VD) {
575  //TODO:AZ: remove explicit insertion after refactoring is done.
576  Dst.insert(Pred);
577  return;
578  }
579 
580  // FIXME: all pre/post visits should eventually be handled by ::Visit().
581  ExplodedNodeSet dstPreVisit;
582  getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this);
583 
584  ExplodedNodeSet dstEvaluated;
585  StmtNodeBuilder B(dstPreVisit, dstEvaluated, *currBldrCtx);
586  for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end();
587  I!=E; ++I) {
588  ExplodedNode *N = *I;
590  const LocationContext *LC = N->getLocationContext();
591 
592  // Decls without InitExpr are not initialized explicitly.
593  if (const Expr *InitEx = VD->getInit()) {
594 
595  // Note in the state that the initialization has occurred.
596  ExplodedNode *UpdatedN = N;
597  SVal InitVal = state->getSVal(InitEx, LC);
598 
599  assert(DS->isSingleDecl());
600  if (getObjectUnderConstruction(state, DS, LC)) {
601  state = finishObjectConstruction(state, DS, LC);
602  // We constructed the object directly in the variable.
603  // No need to bind anything.
604  B.generateNode(DS, UpdatedN, state);
605  } else {
606  // Recover some path-sensitivity if a scalar value evaluated to
607  // UnknownVal.
608  if (InitVal.isUnknown()) {
609  QualType Ty = InitEx->getType();
610  if (InitEx->isGLValue()) {
611  Ty = getContext().getPointerType(Ty);
612  }
613 
614  InitVal = svalBuilder.conjureSymbolVal(nullptr, InitEx, LC, Ty,
615  currBldrCtx->blockCount());
616  }
617 
618 
619  B.takeNodes(UpdatedN);
620  ExplodedNodeSet Dst2;
621  evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true);
622  B.addNodes(Dst2);
623  }
624  }
625  else {
626  B.generateNode(DS, N, state);
627  }
628  }
629 
630  getCheckerManager().runCheckersForPostStmt(Dst, B.getResults(), DS, *this);
631 }
632 
634  ExplodedNodeSet &Dst) {
635  // This method acts upon CFG elements for logical operators && and ||
636  // and attaches the value (true or false) to them as expressions.
637  // It doesn't produce any state splits.
638  // If we made it that far, we're past the point when we modeled the short
639  // circuit. It means that we should have precise knowledge about whether
640  // we've short-circuited. If we did, we already know the value we need to
641  // bind. If we didn't, the value of the RHS (casted to the boolean type)
642  // is the answer.
643  // Currently this method tries to figure out whether we've short-circuited
644  // by looking at the ExplodedGraph. This method is imperfect because there
645  // could inevitably have been merges that would have resulted in multiple
646  // potential path traversal histories. We bail out when we fail.
647  // Due to this ambiguity, a more reliable solution would have been to
648  // track the short circuit operation history path-sensitively until
649  // we evaluate the respective logical operator.
650  assert(B->getOpcode() == BO_LAnd ||
651  B->getOpcode() == BO_LOr);
652 
653  StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
654  ProgramStateRef state = Pred->getState();
655 
656  if (B->getType()->isVectorType()) {
657  // FIXME: We do not model vector arithmetic yet. When adding support for
658  // that, note that the CFG-based reasoning below does not apply, because
659  // logical operators on vectors are not short-circuit. Currently they are
660  // modeled as short-circuit in Clang CFG but this is incorrect.
661  // Do not set the value for the expression. It'd be UnknownVal by default.
662  Bldr.generateNode(B, Pred, state);
663  return;
664  }
665 
666  ExplodedNode *N = Pred;
667  while (!N->getLocation().getAs<BlockEntrance>()) {
668  ProgramPoint P = N->getLocation();
669  assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>());
670  (void) P;
671  if (N->pred_size() != 1) {
672  // We failed to track back where we came from.
673  Bldr.generateNode(B, Pred, state);
674  return;
675  }
676  N = *N->pred_begin();
677  }
678 
679  if (N->pred_size() != 1) {
680  // We failed to track back where we came from.
681  Bldr.generateNode(B, Pred, state);
682  return;
683  }
684 
685  N = *N->pred_begin();
686  BlockEdge BE = N->getLocation().castAs<BlockEdge>();
687  SVal X;
688 
689  // Determine the value of the expression by introspecting how we
690  // got this location in the CFG. This requires looking at the previous
691  // block we were in and what kind of control-flow transfer was involved.
692  const CFGBlock *SrcBlock = BE.getSrc();
693  // The only terminator (if there is one) that makes sense is a logical op.
694  CFGTerminator T = SrcBlock->getTerminator();
695  if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) {
696  (void) Term;
697  assert(Term->isLogicalOp());
698  assert(SrcBlock->succ_size() == 2);
699  // Did we take the true or false branch?
700  unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 1 : 0;
701  X = svalBuilder.makeIntVal(constant, B->getType());
702  }
703  else {
704  // If there is no terminator, by construction the last statement
705  // in SrcBlock is the value of the enclosing expression.
706  // However, we still need to constrain that value to be 0 or 1.
707  assert(!SrcBlock->empty());
708  CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>();
709  const Expr *RHS = cast<Expr>(Elem.getStmt());
710  SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext());
711 
712  if (RHSVal.isUndef()) {
713  X = RHSVal;
714  } else {
715  // We evaluate "RHSVal != 0" expression which result in 0 if the value is
716  // known to be false, 1 if the value is known to be true and a new symbol
717  // when the assumption is unknown.
719  X = evalBinOp(N->getState(), BO_NE,
720  svalBuilder.evalCast(RHSVal, B->getType(), RHS->getType()),
721  Zero, B->getType());
722  }
723  }
724  Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X));
725 }
726 
728  ExplodedNode *Pred,
729  ExplodedNodeSet &Dst) {
730  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
731 
732  ProgramStateRef state = Pred->getState();
733  const LocationContext *LCtx = Pred->getLocationContext();
735  unsigned NumInitElements = IE->getNumInits();
736 
737  if (!IE->isGLValue() && !IE->isTransparent() &&
738  (T->isArrayType() || T->isRecordType() || T->isVectorType() ||
739  T->isAnyComplexType())) {
740  llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList();
741 
742  // Handle base case where the initializer has no elements.
743  // e.g: static int* myArray[] = {};
744  if (NumInitElements == 0) {
745  SVal V = svalBuilder.makeCompoundVal(T, vals);
746  B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
747  return;
748  }
749 
751  ei = IE->rend(); it != ei; ++it) {
752  SVal V = state->getSVal(cast<Expr>(*it), LCtx);
753  vals = getBasicVals().prependSVal(V, vals);
754  }
755 
756  B.generateNode(IE, Pred,
757  state->BindExpr(IE, LCtx,
758  svalBuilder.makeCompoundVal(T, vals)));
759  return;
760  }
761 
762  // Handle scalars: int{5} and int{} and GLvalues.
763  // Note, if the InitListExpr is a GLvalue, it means that there is an address
764  // representing it, so it must have a single init element.
765  assert(NumInitElements <= 1);
766 
767  SVal V;
768  if (NumInitElements == 0)
769  V = getSValBuilder().makeZeroVal(T);
770  else
771  V = state->getSVal(IE->getInit(0), LCtx);
772 
773  B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
774 }
775 
777  const Expr *L,
778  const Expr *R,
779  ExplodedNode *Pred,
780  ExplodedNodeSet &Dst) {
781  assert(L && R);
782 
783  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
784  ProgramStateRef state = Pred->getState();
785  const LocationContext *LCtx = Pred->getLocationContext();
786  const CFGBlock *SrcBlock = nullptr;
787 
788  // Find the predecessor block.
789  ProgramStateRef SrcState = state;
790  for (const ExplodedNode *N = Pred ; N ; N = *N->pred_begin()) {
791  ProgramPoint PP = N->getLocation();
792  if (PP.getAs<PreStmtPurgeDeadSymbols>() || PP.getAs<BlockEntrance>()) {
793  // If the state N has multiple predecessors P, it means that successors
794  // of P are all equivalent.
795  // In turn, that means that all nodes at P are equivalent in terms
796  // of observable behavior at N, and we can follow any of them.
797  // FIXME: a more robust solution which does not walk up the tree.
798  continue;
799  }
800  SrcBlock = PP.castAs<BlockEdge>().getSrc();
801  SrcState = N->getState();
802  break;
803  }
804 
805  assert(SrcBlock && "missing function entry");
806 
807  // Find the last expression in the predecessor block. That is the
808  // expression that is used for the value of the ternary expression.
809  bool hasValue = false;
810  SVal V;
811 
812  for (CFGElement CE : llvm::reverse(*SrcBlock)) {
813  if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) {
814  const Expr *ValEx = cast<Expr>(CS->getStmt());
815  ValEx = ValEx->IgnoreParens();
816 
817  // For GNU extension '?:' operator, the left hand side will be an
818  // OpaqueValueExpr, so get the underlying expression.
819  if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L))
820  L = OpaqueEx->getSourceExpr();
821 
822  // If the last expression in the predecessor block matches true or false
823  // subexpression, get its the value.
824  if (ValEx == L->IgnoreParens() || ValEx == R->IgnoreParens()) {
825  hasValue = true;
826  V = SrcState->getSVal(ValEx, LCtx);
827  }
828  break;
829  }
830  }
831 
832  if (!hasValue)
833  V = svalBuilder.conjureSymbolVal(nullptr, Ex, LCtx,
834  currBldrCtx->blockCount());
835 
836  // Generate a new node with the binding from the appropriate path.
837  B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true));
838 }
839 
840 void ExprEngine::
842  ExplodedNode *Pred, ExplodedNodeSet &Dst) {
843  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
844  Expr::EvalResult Result;
845  if (OOE->EvaluateAsInt(Result, getContext())) {
846  APSInt IV = Result.Val.getInt();
847  assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType()));
848  assert(OOE->getType()->isBuiltinType());
849  assert(OOE->getType()->getAs<BuiltinType>()->isInteger());
850  assert(IV.isSigned() == OOE->getType()->isSignedIntegerType());
851  SVal X = svalBuilder.makeIntVal(IV);
852  B.generateNode(OOE, Pred,
853  Pred->getState()->BindExpr(OOE, Pred->getLocationContext(),
854  X));
855  }
856  // FIXME: Handle the case where __builtin_offsetof is not a constant.
857 }
858 
859 
860 void ExprEngine::
862  ExplodedNode *Pred,
863  ExplodedNodeSet &Dst) {
864  // FIXME: Prechecks eventually go in ::Visit().
865  ExplodedNodeSet CheckedSet;
866  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, Ex, *this);
867 
868  ExplodedNodeSet EvalSet;
869  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
870 
871  QualType T = Ex->getTypeOfArgument();
872 
873  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
874  I != E; ++I) {
875  if (Ex->getKind() == UETT_SizeOf) {
876  if (!T->isIncompleteType() && !T->isConstantSizeType()) {
877  assert(T->isVariableArrayType() && "Unknown non-constant-sized type.");
878 
879  // FIXME: Add support for VLA type arguments and VLA expressions.
880  // When that happens, we should probably refactor VLASizeChecker's code.
881  continue;
882  } else if (T->getAs<ObjCObjectType>()) {
883  // Some code tries to take the sizeof an ObjCObjectType, relying that
884  // the compiler has laid out its representation. Just report Unknown
885  // for these.
886  continue;
887  }
888  }
889 
890  APSInt Value = Ex->EvaluateKnownConstInt(getContext());
891  CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue());
892 
893  ProgramStateRef state = (*I)->getState();
894  state = state->BindExpr(Ex, (*I)->getLocationContext(),
895  svalBuilder.makeIntVal(amt.getQuantity(),
896  Ex->getType()));
897  Bldr.generateNode(Ex, *I, state);
898  }
899 
900  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, Ex, *this);
901 }
902 
904  const UnaryOperator *U,
905  StmtNodeBuilder &Bldr) {
906  // FIXME: We can probably just have some magic in Environment::getSVal()
907  // that propagates values, instead of creating a new node here.
908  //
909  // Unary "+" is a no-op, similar to a parentheses. We still have places
910  // where it may be a block-level expression, so we need to
911  // generate an extra node that just propagates the value of the
912  // subexpression.
913  const Expr *Ex = U->getSubExpr()->IgnoreParens();
914  ProgramStateRef state = (*I)->getState();
915  const LocationContext *LCtx = (*I)->getLocationContext();
916  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
917  state->getSVal(Ex, LCtx)));
918 }
919 
921  ExplodedNodeSet &Dst) {
922  // FIXME: Prechecks eventually go in ::Visit().
923  ExplodedNodeSet CheckedSet;
924  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, U, *this);
925 
926  ExplodedNodeSet EvalSet;
927  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
928 
929  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
930  I != E; ++I) {
931  switch (U->getOpcode()) {
932  default: {
933  Bldr.takeNodes(*I);
934  ExplodedNodeSet Tmp;
936  Bldr.addNodes(Tmp);
937  break;
938  }
939  case UO_Real: {
940  const Expr *Ex = U->getSubExpr()->IgnoreParens();
941 
942  // FIXME: We don't have complex SValues yet.
943  if (Ex->getType()->isAnyComplexType()) {
944  // Just report "Unknown."
945  break;
946  }
947 
948  // For all other types, UO_Real is an identity operation.
949  assert (U->getType() == Ex->getType());
950  ProgramStateRef state = (*I)->getState();
951  const LocationContext *LCtx = (*I)->getLocationContext();
952  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
953  state->getSVal(Ex, LCtx)));
954  break;
955  }
956 
957  case UO_Imag: {
958  const Expr *Ex = U->getSubExpr()->IgnoreParens();
959  // FIXME: We don't have complex SValues yet.
960  if (Ex->getType()->isAnyComplexType()) {
961  // Just report "Unknown."
962  break;
963  }
964  // For all other types, UO_Imag returns 0.
965  ProgramStateRef state = (*I)->getState();
966  const LocationContext *LCtx = (*I)->getLocationContext();
967  SVal X = svalBuilder.makeZeroVal(Ex->getType());
968  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, X));
969  break;
970  }
971 
972  case UO_AddrOf: {
973  // Process pointer-to-member address operation.
974  const Expr *Ex = U->getSubExpr()->IgnoreParens();
975  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex)) {
976  const ValueDecl *VD = DRE->getDecl();
977 
978  if (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD)) {
979  ProgramStateRef State = (*I)->getState();
980  const LocationContext *LCtx = (*I)->getLocationContext();
981  SVal SV = svalBuilder.getMemberPointer(cast<DeclaratorDecl>(VD));
982  Bldr.generateNode(U, *I, State->BindExpr(U, LCtx, SV));
983  break;
984  }
985  }
986  // Explicitly proceed with default handler for this case cascade.
987  handleUOExtension(I, U, Bldr);
988  break;
989  }
990  case UO_Plus:
991  assert(!U->isGLValue());
992  LLVM_FALLTHROUGH;
993  case UO_Deref:
994  case UO_Extension: {
995  handleUOExtension(I, U, Bldr);
996  break;
997  }
998 
999  case UO_LNot:
1000  case UO_Minus:
1001  case UO_Not: {
1002  assert (!U->isGLValue());
1003  const Expr *Ex = U->getSubExpr()->IgnoreParens();
1004  ProgramStateRef state = (*I)->getState();
1005  const LocationContext *LCtx = (*I)->getLocationContext();
1006 
1007  // Get the value of the subexpression.
1008  SVal V = state->getSVal(Ex, LCtx);
1009 
1010  if (V.isUnknownOrUndef()) {
1011  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V));
1012  break;
1013  }
1014 
1015  switch (U->getOpcode()) {
1016  default:
1017  llvm_unreachable("Invalid Opcode.");
1018  case UO_Not:
1019  // FIXME: Do we need to handle promotions?
1020  state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>()));
1021  break;
1022  case UO_Minus:
1023  // FIXME: Do we need to handle promotions?
1024  state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>()));
1025  break;
1026  case UO_LNot:
1027  // C99 6.5.3.3: "The expression !E is equivalent to (0==E)."
1028  //
1029  // Note: technically we do "E == 0", but this is the same in the
1030  // transfer functions as "0 == E".
1031  SVal Result;
1032  if (Optional<Loc> LV = V.getAs<Loc>()) {
1033  Loc X = svalBuilder.makeNullWithType(Ex->getType());
1034  Result = evalBinOp(state, BO_EQ, *LV, X, U->getType());
1035  } else if (Ex->getType()->isFloatingType()) {
1036  // FIXME: handle floating point types.
1037  Result = UnknownVal();
1038  } else {
1039  nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType()));
1040  Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X,
1041  U->getType());
1042  }
1043 
1044  state = state->BindExpr(U, LCtx, Result);
1045  break;
1046  }
1047  Bldr.generateNode(U, *I, state);
1048  break;
1049  }
1050  }
1051  }
1052 
1053  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, U, *this);
1054 }
1055 
1057  ExplodedNode *Pred,
1058  ExplodedNodeSet &Dst) {
1059  // Handle ++ and -- (both pre- and post-increment).
1060  assert (U->isIncrementDecrementOp());
1061  const Expr *Ex = U->getSubExpr()->IgnoreParens();
1062 
1063  const LocationContext *LCtx = Pred->getLocationContext();
1064  ProgramStateRef state = Pred->getState();
1065  SVal loc = state->getSVal(Ex, LCtx);
1066 
1067  // Perform a load.
1068  ExplodedNodeSet Tmp;
1069  evalLoad(Tmp, U, Ex, Pred, state, loc);
1070 
1071  ExplodedNodeSet Dst2;
1072  StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx);
1073  for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;++I) {
1074 
1075  state = (*I)->getState();
1076  assert(LCtx == (*I)->getLocationContext());
1077  SVal V2_untested = state->getSVal(Ex, LCtx);
1078 
1079  // Propagate unknown and undefined values.
1080  if (V2_untested.isUnknownOrUndef()) {
1081  state = state->BindExpr(U, LCtx, V2_untested);
1082 
1083  // Perform the store, so that the uninitialized value detection happens.
1084  Bldr.takeNodes(*I);
1085  ExplodedNodeSet Dst3;
1086  evalStore(Dst3, U, Ex, *I, state, loc, V2_untested);
1087  Bldr.addNodes(Dst3);
1088 
1089  continue;
1090  }
1091  DefinedSVal V2 = V2_untested.castAs<DefinedSVal>();
1092 
1093  // Handle all other values.
1094  BinaryOperator::Opcode Op = U->isIncrementOp() ? BO_Add : BO_Sub;
1095 
1096  // If the UnaryOperator has non-location type, use its type to create the
1097  // constant value. If the UnaryOperator has location type, create the
1098  // constant with int type and pointer width.
1099  SVal RHS;
1100  SVal Result;
1101 
1102  if (U->getType()->isAnyPointerType())
1103  RHS = svalBuilder.makeArrayIndex(1);
1104  else if (U->getType()->isIntegralOrEnumerationType())
1105  RHS = svalBuilder.makeIntVal(1, U->getType());
1106  else
1107  RHS = UnknownVal();
1108 
1109  // The use of an operand of type bool with the ++ operators is deprecated
1110  // but valid until C++17. And if the operand of the ++ operator is of type
1111  // bool, it is set to true until C++17. Note that for '_Bool', it is also
1112  // set to true when it encounters ++ operator.
1113  if (U->getType()->isBooleanType() && U->isIncrementOp())
1114  Result = svalBuilder.makeTruthVal(true, U->getType());
1115  else
1116  Result = evalBinOp(state, Op, V2, RHS, U->getType());
1117 
1118  // Conjure a new symbol if necessary to recover precision.
1119  if (Result.isUnknown()){
1120  DefinedOrUnknownSVal SymVal =
1121  svalBuilder.conjureSymbolVal(nullptr, U, LCtx,
1122  currBldrCtx->blockCount());
1123  Result = SymVal;
1124 
1125  // If the value is a location, ++/-- should always preserve
1126  // non-nullness. Check if the original value was non-null, and if so
1127  // propagate that constraint.
1128  if (Loc::isLocType(U->getType())) {
1129  DefinedOrUnknownSVal Constraint =
1130  svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType()));
1131 
1132  if (!state->assume(Constraint, true)) {
1133  // It isn't feasible for the original value to be null.
1134  // Propagate this constraint.
1135  Constraint = svalBuilder.evalEQ(state, SymVal,
1136  svalBuilder.makeZeroVal(U->getType()));
1137 
1138  state = state->assume(Constraint, false);
1139  assert(state);
1140  }
1141  }
1142  }
1143 
1144  // Since the lvalue-to-rvalue conversion is explicit in the AST,
1145  // we bind an l-value if the operator is prefix and an lvalue (in C++).
1146  if (U->isGLValue())
1147  state = state->BindExpr(U, LCtx, loc);
1148  else
1149  state = state->BindExpr(U, LCtx, U->isPostfix() ? V2 : Result);
1150 
1151  // Perform the store.
1152  Bldr.takeNodes(*I);
1153  ExplodedNodeSet Dst3;
1154  evalStore(Dst3, U, Ex, *I, state, loc, Result);
1155  Bldr.addNodes(Dst3);
1156  }
1157  Dst.insert(Dst2);
1158 }
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:5488
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:4509
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:732
A (possibly-)qualified type.
Definition: Type.h:643
bool isArrayType() const
Definition: Type.h:6407
succ_iterator succ_begin()
Definition: CFG.h:769
capture_const_iterator capture_begin() const
Definition: Decl.h:4013
const Expr * getInit(unsigned Init) const
Definition: Expr.h:4352
unsigned blockCount() const
Returns the number of times the current basic block has been visited on the exploded graph path...
Definition: CoreEngine.h:220
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:378
bool isRecordType() const
Definition: Type.h:6431
const CFGBlock * getSrc() const
Definition: ProgramPoint.h:511
QualType getLValueReferenceType(QualType T, bool SpelledAsLValue=true) const
Return the uniqued reference to the type for an lvalue reference to the specified type...
bool isTransparent() const
Is this a transparent initializer list (that is, an InitListExpr that is purely syntactic, and whose semantics are that of the sole contained initializer)?
Definition: Expr.cpp:2187
Opcode getOpcode() const
Definition: Expr.h:3373
StringRef P
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, NonLoc L, NonLoc R, QualType T)
Definition: ExprEngine.h:584
Represents a point after we ran remove dead bindings BEFORE processing the given statement.
Definition: ProgramPoint.h:473
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:379
capture_const_iterator capture_end() const
Definition: Decl.h:4014
unsigned succ_size() const
Definition: CFG.h:787
void VisitUnaryOperator(const UnaryOperator *B, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitUnaryOperator - Transfer function logic for unary operators.
void takeNodes(const ExplodedNodeSet &S)
Definition: CoreEngine.h:329
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:2981
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6818
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:481
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:3464
Defines the clang::Expr interface and subclasses for C++ expressions.
bool isVariableArrayType() const
Definition: Type.h:6419
InitExprsTy::const_reverse_iterator const_reverse_iterator
Definition: Expr.h:4503
Represents a class type in Objective C.
Definition: Type.h:5593
Value representing pointer-to-member.
Definition: SVals.h:524
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:2022
bool isReferenceType() const
Definition: Type.h:6363
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:6714
llvm::ImmutableList< SVal > prependSVal(SVal X, llvm::ImmutableList< SVal > L)
static bool isLocType(QualType T)
Definition: SVals.h:329
bool isGLValue() const
Definition: Expr.h:261
Describes an C or C++ initializer list.
Definition: Expr.h:4304
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:417
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:582
path_iterator path_begin()
Definition: Expr.h:3126
const LocationContext * getLocationContext() const
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3338
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:1996
bool isRValueReferenceType() const
Definition: Type.h:6371
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:3054
SVal evalComplement(SVal X)
Definition: ExprEngine.h:563
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:222
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:190
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:2275
Represents a single basic block in a source-level CFG.
Definition: CFG.h:570
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:3884
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).
#define V(N, I)
Definition: ASTContext.h:2905
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5474
unsigned getNumInits() const
Definition: Expr.h:4334
const ExplodedNodeSet & getResults()
Definition: CoreEngine.h:306
bool isAnyComplexType() const
Definition: Type.h:6439
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:1875
const CFGBlock * getDst() const
Definition: ProgramPoint.h:515
QualType getType() const
Definition: Expr.h:137
QualType getTypeOfArgument() const
Gets the argument type, or the type of the argument expression, whichever is appropriate.
Definition: Expr.h:2338
The reason for pointer escape is unknown.
ASTContext & getContext() const
getContext - Return the ASTContext associated with this analysis.
Definition: ExprEngine.h:182
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:1949
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:726
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
OpaqueValueExpr - An expression referring to an opaque object of a fixed type and value class...
Definition: Expr.h:985
bool isBuiltinType() const
Helper methods to distinguish type categories.
Definition: Type.h:6427
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:1979
T castAs() const
Convert to the specified ProgramPoint type, asserting that this ProgramPoint is of the desired type...
Definition: ProgramPoint.h:140
CastKind getCastKind() const
Definition: Expr.h:3100
const MemRegion * getAsRegion() const
Definition: SVals.cpp:151
DeclStmt - Adaptor class for mixing declarations with statements and expressions. ...
Definition: Stmt.h:1183
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:2306
decl_iterator decl_begin()
Definition: Stmt.h:1237
void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, ExplodedNode *Pred, ExplodedNodeSet &Dst)
VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
bool isAnyPointerType() const
Definition: Type.h:6355
BasicValueFactory & getBasicVals()
Definition: ExprEngine.h:393
void runCheckersForPreStmt(ExplodedNodeSet &Dst, const ExplodedNodeSet &Src, const Stmt *S, ExprEngine &Eng)
Run checkers for pre-visiting Stmts.
bool isVectorType() const
Definition: Type.h:6443
void insert(const ExplodedNodeSet &S)
const Expr * getInitializer() const
Definition: Expr.h:3007
Expr * getLHS() const
Definition: Expr.h:3378
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:194
EvalResult is a struct with detailed info about an evaluated expression.
Definition: Expr.h:580
void addNodes(const ExplodedNodeSet &S)
Definition: CoreEngine.h:335
StoreManager & getStoreManager()
Definition: ExprEngine.h:386
bool isZeroConstant() const
Definition: SVals.cpp:234
const Expr * getInit() const
Definition: Decl.h:1219
bool isBooleanType() const
Definition: Type.h:6727
SVal evalEQ(ProgramStateRef state, SVal lhs, SVal rhs)
ExplicitCastExpr - An explicit cast written in the source code.
Definition: Expr.h:3241
bool isSingleDecl() const
isSingleDecl - This method returns true if this DeclStmt refers to a single Decl. ...
Definition: Stmt.h:1196
Stmt * getStmt()
Definition: CFG.h:529
path_iterator path_end()
Definition: Expr.h:3127
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:2052
SVal evalMinus(SVal X)
Definition: ExprEngine.h:559
DefinedSVal getMemberPointer(const DeclaratorDecl *DD)
Opcode getOpcode() const
Definition: Expr.h:1974
static bool isAdditiveOp(Opcode Opc)
Definition: Expr.h:3414
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2076
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types...
Definition: Type.cpp:2062
static bool isIncrementOp(Opcode Op)
Definition: Expr.h:2008
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2277
bool isLValueReferenceType() const
Definition: Type.h:6367
reverse_iterator rend()
Definition: Expr.h:4511
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:14125
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:3469
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:2408
Represents CFGBlock terminator statement.
Definition: CFG.h:497
ExplodedNode * generateNode(const Stmt *S, ExplodedNode *Pred, ProgramStateRef St, const ProgramPointTag *tag=nullptr, ProgramPoint::Kind K=ProgramPoint::PostStmtKind)
Definition: CoreEngine.h:407
bool isUndef() const
Definition: SVals.h:140
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1081
result[0]
Definition: emmintrin.h:120
Expr * getRHS() const
Definition: Expr.h:3380
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:151
OffsetOfExpr - [C99 7.17] - This represents an expression of the form offsetof(record-type, member-designator).
Definition: Expr.h:2170
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:332
CFGTerminator getTerminator() const
Definition: CFG.h:858
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:2844