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SimpleSValBuilder.cpp
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1 // SimpleSValBuilder.cpp - A basic SValBuilder -----------------------*- C++ -*-
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines SimpleSValBuilder, a basic implementation of SValBuilder.
11 //
12 //===----------------------------------------------------------------------===//
13 
18 
19 using namespace clang;
20 using namespace ento;
21 
22 namespace {
23 class SimpleSValBuilder : public SValBuilder {
24 protected:
25  SVal dispatchCast(SVal val, QualType castTy) override;
26  SVal evalCastFromNonLoc(NonLoc val, QualType castTy) override;
27  SVal evalCastFromLoc(Loc val, QualType castTy) override;
28 
29 public:
30  SimpleSValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context,
31  ProgramStateManager &stateMgr)
32  : SValBuilder(alloc, context, stateMgr) {}
33  ~SimpleSValBuilder() override {}
34 
35  SVal evalMinus(NonLoc val) override;
36  SVal evalComplement(NonLoc val) override;
38  NonLoc lhs, NonLoc rhs, QualType resultTy) override;
40  Loc lhs, Loc rhs, QualType resultTy) override;
42  Loc lhs, NonLoc rhs, QualType resultTy) override;
43 
44  /// getKnownValue - evaluates a given SVal. If the SVal has only one possible
45  /// (integer) value, that value is returned. Otherwise, returns NULL.
46  const llvm::APSInt *getKnownValue(ProgramStateRef state, SVal V) override;
47 
48  /// Recursively descends into symbolic expressions and replaces symbols
49  /// with their known values (in the sense of the getKnownValue() method).
50  SVal simplifySVal(ProgramStateRef State, SVal V) override;
51 
52  SVal MakeSymIntVal(const SymExpr *LHS, BinaryOperator::Opcode op,
53  const llvm::APSInt &RHS, QualType resultTy);
54 };
55 } // end anonymous namespace
56 
57 SValBuilder *ento::createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc,
58  ASTContext &context,
59  ProgramStateManager &stateMgr) {
60  return new SimpleSValBuilder(alloc, context, stateMgr);
61 }
62 
63 //===----------------------------------------------------------------------===//
64 // Transfer function for Casts.
65 //===----------------------------------------------------------------------===//
66 
67 SVal SimpleSValBuilder::dispatchCast(SVal Val, QualType CastTy) {
68  assert(Val.getAs<Loc>() || Val.getAs<NonLoc>());
69  return Val.getAs<Loc>() ? evalCastFromLoc(Val.castAs<Loc>(), CastTy)
70  : evalCastFromNonLoc(Val.castAs<NonLoc>(), CastTy);
71 }
72 
73 SVal SimpleSValBuilder::evalCastFromNonLoc(NonLoc val, QualType castTy) {
74  bool isLocType = Loc::isLocType(castTy);
75  if (val.getAs<nonloc::PointerToMember>())
76  return val;
77 
79  if (isLocType)
80  return LI->getLoc();
81  // FIXME: Correctly support promotions/truncations.
82  unsigned castSize = Context.getIntWidth(castTy);
83  if (castSize == LI->getNumBits())
84  return val;
85  return makeLocAsInteger(LI->getLoc(), castSize);
86  }
87 
88  if (const SymExpr *se = val.getAsSymbolicExpression()) {
89  QualType T = Context.getCanonicalType(se->getType());
90  // If types are the same or both are integers, ignore the cast.
91  // FIXME: Remove this hack when we support symbolic truncation/extension.
92  // HACK: If both castTy and T are integers, ignore the cast. This is
93  // not a permanent solution. Eventually we want to precisely handle
94  // extension/truncation of symbolic integers. This prevents us from losing
95  // precision when we assign 'x = y' and 'y' is symbolic and x and y are
96  // different integer types.
97  if (haveSameType(T, castTy))
98  return val;
99 
100  if (!isLocType)
101  return makeNonLoc(se, T, castTy);
102  return UnknownVal();
103  }
104 
105  // If value is a non-integer constant, produce unknown.
106  if (!val.getAs<nonloc::ConcreteInt>())
107  return UnknownVal();
108 
109  // Handle casts to a boolean type.
110  if (castTy->isBooleanType()) {
111  bool b = val.castAs<nonloc::ConcreteInt>().getValue().getBoolValue();
112  return makeTruthVal(b, castTy);
113  }
114 
115  // Only handle casts from integers to integers - if val is an integer constant
116  // being cast to a non-integer type, produce unknown.
117  if (!isLocType && !castTy->isIntegralOrEnumerationType())
118  return UnknownVal();
119 
120  llvm::APSInt i = val.castAs<nonloc::ConcreteInt>().getValue();
121  BasicVals.getAPSIntType(castTy).apply(i);
122 
123  if (isLocType)
124  return makeIntLocVal(i);
125  else
126  return makeIntVal(i);
127 }
128 
129 SVal SimpleSValBuilder::evalCastFromLoc(Loc val, QualType castTy) {
130 
131  // Casts from pointers -> pointers, just return the lval.
132  //
133  // Casts from pointers -> references, just return the lval. These
134  // can be introduced by the frontend for corner cases, e.g
135  // casting from va_list* to __builtin_va_list&.
136  //
137  if (Loc::isLocType(castTy) || castTy->isReferenceType())
138  return val;
139 
140  // FIXME: Handle transparent unions where a value can be "transparently"
141  // lifted into a union type.
142  if (castTy->isUnionType())
143  return UnknownVal();
144 
145  // Casting a Loc to a bool will almost always be true,
146  // unless this is a weak function or a symbolic region.
147  if (castTy->isBooleanType()) {
148  switch (val.getSubKind()) {
149  case loc::MemRegionValKind: {
150  const MemRegion *R = val.castAs<loc::MemRegionVal>().getRegion();
151  if (const FunctionCodeRegion *FTR = dyn_cast<FunctionCodeRegion>(R))
152  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(FTR->getDecl()))
153  if (FD->isWeak())
154  // FIXME: Currently we are using an extent symbol here,
155  // because there are no generic region address metadata
156  // symbols to use, only content metadata.
157  return nonloc::SymbolVal(SymMgr.getExtentSymbol(FTR));
158 
159  if (const SymbolicRegion *SymR = R->getSymbolicBase())
160  return nonloc::SymbolVal(SymR->getSymbol());
161 
162  // FALL-THROUGH
163  LLVM_FALLTHROUGH;
164  }
165 
166  case loc::GotoLabelKind:
167  // Labels and non-symbolic memory regions are always true.
168  return makeTruthVal(true, castTy);
169  }
170  }
171 
172  if (castTy->isIntegralOrEnumerationType()) {
173  unsigned BitWidth = Context.getIntWidth(castTy);
174 
175  if (!val.getAs<loc::ConcreteInt>())
176  return makeLocAsInteger(val, BitWidth);
177 
178  llvm::APSInt i = val.castAs<loc::ConcreteInt>().getValue();
179  BasicVals.getAPSIntType(castTy).apply(i);
180  return makeIntVal(i);
181  }
182 
183  // All other cases: return 'UnknownVal'. This includes casting pointers
184  // to floats, which is probably badness it itself, but this is a good
185  // intermediate solution until we do something better.
186  return UnknownVal();
187 }
188 
189 //===----------------------------------------------------------------------===//
190 // Transfer function for unary operators.
191 //===----------------------------------------------------------------------===//
192 
193 SVal SimpleSValBuilder::evalMinus(NonLoc val) {
194  switch (val.getSubKind()) {
195  case nonloc::ConcreteIntKind:
196  return val.castAs<nonloc::ConcreteInt>().evalMinus(*this);
197  default:
198  return UnknownVal();
199  }
200 }
201 
202 SVal SimpleSValBuilder::evalComplement(NonLoc X) {
203  switch (X.getSubKind()) {
204  case nonloc::ConcreteIntKind:
205  return X.castAs<nonloc::ConcreteInt>().evalComplement(*this);
206  default:
207  return UnknownVal();
208  }
209 }
210 
211 //===----------------------------------------------------------------------===//
212 // Transfer function for binary operators.
213 //===----------------------------------------------------------------------===//
214 
215 SVal SimpleSValBuilder::MakeSymIntVal(const SymExpr *LHS,
217  const llvm::APSInt &RHS,
218  QualType resultTy) {
219  bool isIdempotent = false;
220 
221  // Check for a few special cases with known reductions first.
222  switch (op) {
223  default:
224  // We can't reduce this case; just treat it normally.
225  break;
226  case BO_Mul:
227  // a*0 and a*1
228  if (RHS == 0)
229  return makeIntVal(0, resultTy);
230  else if (RHS == 1)
231  isIdempotent = true;
232  break;
233  case BO_Div:
234  // a/0 and a/1
235  if (RHS == 0)
236  // This is also handled elsewhere.
237  return UndefinedVal();
238  else if (RHS == 1)
239  isIdempotent = true;
240  break;
241  case BO_Rem:
242  // a%0 and a%1
243  if (RHS == 0)
244  // This is also handled elsewhere.
245  return UndefinedVal();
246  else if (RHS == 1)
247  return makeIntVal(0, resultTy);
248  break;
249  case BO_Add:
250  case BO_Sub:
251  case BO_Shl:
252  case BO_Shr:
253  case BO_Xor:
254  // a+0, a-0, a<<0, a>>0, a^0
255  if (RHS == 0)
256  isIdempotent = true;
257  break;
258  case BO_And:
259  // a&0 and a&(~0)
260  if (RHS == 0)
261  return makeIntVal(0, resultTy);
262  else if (RHS.isAllOnesValue())
263  isIdempotent = true;
264  break;
265  case BO_Or:
266  // a|0 and a|(~0)
267  if (RHS == 0)
268  isIdempotent = true;
269  else if (RHS.isAllOnesValue()) {
270  const llvm::APSInt &Result = BasicVals.Convert(resultTy, RHS);
271  return nonloc::ConcreteInt(Result);
272  }
273  break;
274  }
275 
276  // Idempotent ops (like a*1) can still change the type of an expression.
277  // Wrap the LHS up in a NonLoc again and let evalCastFromNonLoc do the
278  // dirty work.
279  if (isIdempotent)
280  return evalCastFromNonLoc(nonloc::SymbolVal(LHS), resultTy);
281 
282  // If we reach this point, the expression cannot be simplified.
283  // Make a SymbolVal for the entire expression, after converting the RHS.
284  const llvm::APSInt *ConvertedRHS = &RHS;
286  // We're looking for a type big enough to compare the symbolic value
287  // with the given constant.
288  // FIXME: This is an approximation of Sema::UsualArithmeticConversions.
289  ASTContext &Ctx = getContext();
290  QualType SymbolType = LHS->getType();
291  uint64_t ValWidth = RHS.getBitWidth();
292  uint64_t TypeWidth = Ctx.getTypeSize(SymbolType);
293 
294  if (ValWidth < TypeWidth) {
295  // If the value is too small, extend it.
296  ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
297  } else if (ValWidth == TypeWidth) {
298  // If the value is signed but the symbol is unsigned, do the comparison
299  // in unsigned space. [C99 6.3.1.8]
300  // (For the opposite case, the value is already unsigned.)
301  if (RHS.isSigned() && !SymbolType->isSignedIntegerOrEnumerationType())
302  ConvertedRHS = &BasicVals.Convert(SymbolType, RHS);
303  }
304  } else
305  ConvertedRHS = &BasicVals.Convert(resultTy, RHS);
306 
307  return makeNonLoc(LHS, op, *ConvertedRHS, resultTy);
308 }
309 
310 SVal SimpleSValBuilder::evalBinOpNN(ProgramStateRef state,
312  NonLoc lhs, NonLoc rhs,
313  QualType resultTy) {
314  NonLoc InputLHS = lhs;
315  NonLoc InputRHS = rhs;
316 
317  // Handle trivial case where left-side and right-side are the same.
318  if (lhs == rhs)
319  switch (op) {
320  default:
321  break;
322  case BO_EQ:
323  case BO_LE:
324  case BO_GE:
325  return makeTruthVal(true, resultTy);
326  case BO_LT:
327  case BO_GT:
328  case BO_NE:
329  return makeTruthVal(false, resultTy);
330  case BO_Xor:
331  case BO_Sub:
332  if (resultTy->isIntegralOrEnumerationType())
333  return makeIntVal(0, resultTy);
334  return evalCastFromNonLoc(makeIntVal(0, /*Unsigned=*/false), resultTy);
335  case BO_Or:
336  case BO_And:
337  return evalCastFromNonLoc(lhs, resultTy);
338  }
339 
340  while (1) {
341  switch (lhs.getSubKind()) {
342  default:
343  return makeSymExprValNN(state, op, lhs, rhs, resultTy);
344  case nonloc::PointerToMemberKind: {
345  assert(rhs.getSubKind() == nonloc::PointerToMemberKind &&
346  "Both SVals should have pointer-to-member-type");
347  auto LPTM = lhs.castAs<nonloc::PointerToMember>(),
348  RPTM = rhs.castAs<nonloc::PointerToMember>();
349  auto LPTMD = LPTM.getPTMData(), RPTMD = RPTM.getPTMData();
350  switch (op) {
351  case BO_EQ:
352  return makeTruthVal(LPTMD == RPTMD, resultTy);
353  case BO_NE:
354  return makeTruthVal(LPTMD != RPTMD, resultTy);
355  default:
356  return UnknownVal();
357  }
358  }
359  case nonloc::LocAsIntegerKind: {
360  Loc lhsL = lhs.castAs<nonloc::LocAsInteger>().getLoc();
361  switch (rhs.getSubKind()) {
362  case nonloc::LocAsIntegerKind:
363  // FIXME: at the moment the implementation
364  // of modeling "pointers as integers" is not complete.
366  return UnknownVal();
367  return evalBinOpLL(state, op, lhsL,
369  resultTy);
370  case nonloc::ConcreteIntKind: {
371  // FIXME: at the moment the implementation
372  // of modeling "pointers as integers" is not complete.
374  return UnknownVal();
375  // Transform the integer into a location and compare.
376  // FIXME: This only makes sense for comparisons. If we want to, say,
377  // add 1 to a LocAsInteger, we'd better unpack the Loc and add to it,
378  // then pack it back into a LocAsInteger.
379  llvm::APSInt i = rhs.castAs<nonloc::ConcreteInt>().getValue();
380  BasicVals.getAPSIntType(Context.VoidPtrTy).apply(i);
381  return evalBinOpLL(state, op, lhsL, makeLoc(i), resultTy);
382  }
383  default:
384  switch (op) {
385  case BO_EQ:
386  return makeTruthVal(false, resultTy);
387  case BO_NE:
388  return makeTruthVal(true, resultTy);
389  default:
390  // This case also handles pointer arithmetic.
391  return makeSymExprValNN(state, op, InputLHS, InputRHS, resultTy);
392  }
393  }
394  }
395  case nonloc::ConcreteIntKind: {
396  llvm::APSInt LHSValue = lhs.castAs<nonloc::ConcreteInt>().getValue();
397 
398  // If we're dealing with two known constants, just perform the operation.
399  if (const llvm::APSInt *KnownRHSValue = getKnownValue(state, rhs)) {
400  llvm::APSInt RHSValue = *KnownRHSValue;
402  // We're looking for a type big enough to compare the two values.
403  // FIXME: This is not correct. char + short will result in a promotion
404  // to int. Unfortunately we have lost types by this point.
405  APSIntType CompareType = std::max(APSIntType(LHSValue),
406  APSIntType(RHSValue));
407  CompareType.apply(LHSValue);
408  CompareType.apply(RHSValue);
409  } else if (!BinaryOperator::isShiftOp(op)) {
410  APSIntType IntType = BasicVals.getAPSIntType(resultTy);
411  IntType.apply(LHSValue);
412  IntType.apply(RHSValue);
413  }
414 
415  const llvm::APSInt *Result =
416  BasicVals.evalAPSInt(op, LHSValue, RHSValue);
417  if (!Result)
418  return UndefinedVal();
419 
420  return nonloc::ConcreteInt(*Result);
421  }
422 
423  // Swap the left and right sides and flip the operator if doing so
424  // allows us to better reason about the expression (this is a form
425  // of expression canonicalization).
426  // While we're at it, catch some special cases for non-commutative ops.
427  switch (op) {
428  case BO_LT:
429  case BO_GT:
430  case BO_LE:
431  case BO_GE:
433  // FALL-THROUGH
434  case BO_EQ:
435  case BO_NE:
436  case BO_Add:
437  case BO_Mul:
438  case BO_And:
439  case BO_Xor:
440  case BO_Or:
441  std::swap(lhs, rhs);
442  continue;
443  case BO_Shr:
444  // (~0)>>a
445  if (LHSValue.isAllOnesValue() && LHSValue.isSigned())
446  return evalCastFromNonLoc(lhs, resultTy);
447  // FALL-THROUGH
448  case BO_Shl:
449  // 0<<a and 0>>a
450  if (LHSValue == 0)
451  return evalCastFromNonLoc(lhs, resultTy);
452  return makeSymExprValNN(state, op, InputLHS, InputRHS, resultTy);
453  default:
454  return makeSymExprValNN(state, op, InputLHS, InputRHS, resultTy);
455  }
456  }
457  case nonloc::SymbolValKind: {
458  // We only handle LHS as simple symbols or SymIntExprs.
459  SymbolRef Sym = lhs.castAs<nonloc::SymbolVal>().getSymbol();
460 
461  // LHS is a symbolic expression.
462  if (const SymIntExpr *symIntExpr = dyn_cast<SymIntExpr>(Sym)) {
463 
464  // Is this a logical not? (!x is represented as x == 0.)
465  if (op == BO_EQ && rhs.isZeroConstant()) {
466  // We know how to negate certain expressions. Simplify them here.
467 
468  BinaryOperator::Opcode opc = symIntExpr->getOpcode();
469  switch (opc) {
470  default:
471  // We don't know how to negate this operation.
472  // Just handle it as if it were a normal comparison to 0.
473  break;
474  case BO_LAnd:
475  case BO_LOr:
476  llvm_unreachable("Logical operators handled by branching logic.");
477  case BO_Assign:
478  case BO_MulAssign:
479  case BO_DivAssign:
480  case BO_RemAssign:
481  case BO_AddAssign:
482  case BO_SubAssign:
483  case BO_ShlAssign:
484  case BO_ShrAssign:
485  case BO_AndAssign:
486  case BO_XorAssign:
487  case BO_OrAssign:
488  case BO_Comma:
489  llvm_unreachable("'=' and ',' operators handled by ExprEngine.");
490  case BO_PtrMemD:
491  case BO_PtrMemI:
492  llvm_unreachable("Pointer arithmetic not handled here.");
493  case BO_LT:
494  case BO_GT:
495  case BO_LE:
496  case BO_GE:
497  case BO_EQ:
498  case BO_NE:
499  assert(resultTy->isBooleanType() ||
500  resultTy == getConditionType());
501  assert(symIntExpr->getType()->isBooleanType() ||
502  getContext().hasSameUnqualifiedType(symIntExpr->getType(),
503  getConditionType()));
504  // Negate the comparison and make a value.
506  return makeNonLoc(symIntExpr->getLHS(), opc,
507  symIntExpr->getRHS(), resultTy);
508  }
509  }
510 
511  // For now, only handle expressions whose RHS is a constant.
512  if (const llvm::APSInt *RHSValue = getKnownValue(state, rhs)) {
513  // If both the LHS and the current expression are additive,
514  // fold their constants and try again.
516  BinaryOperator::Opcode lop = symIntExpr->getOpcode();
517  if (BinaryOperator::isAdditiveOp(lop)) {
518  // Convert the two constants to a common type, then combine them.
519 
520  // resultTy may not be the best type to convert to, but it's
521  // probably the best choice in expressions with mixed type
522  // (such as x+1U+2LL). The rules for implicit conversions should
523  // choose a reasonable type to preserve the expression, and will
524  // at least match how the value is going to be used.
525  APSIntType IntType = BasicVals.getAPSIntType(resultTy);
526  const llvm::APSInt &first = IntType.convert(symIntExpr->getRHS());
527  const llvm::APSInt &second = IntType.convert(*RHSValue);
528 
529  const llvm::APSInt *newRHS;
530  if (lop == op)
531  newRHS = BasicVals.evalAPSInt(BO_Add, first, second);
532  else
533  newRHS = BasicVals.evalAPSInt(BO_Sub, first, second);
534 
535  assert(newRHS && "Invalid operation despite common type!");
536  rhs = nonloc::ConcreteInt(*newRHS);
537  lhs = nonloc::SymbolVal(symIntExpr->getLHS());
538  op = lop;
539  continue;
540  }
541  }
542 
543  // Otherwise, make a SymIntExpr out of the expression.
544  return MakeSymIntVal(symIntExpr, op, *RHSValue, resultTy);
545  }
546  }
547 
548  // Does the symbolic expression simplify to a constant?
549  // If so, "fold" the constant by setting 'lhs' to a ConcreteInt
550  // and try again.
551  SVal simplifiedLhs = simplifySVal(state, lhs);
552  if (simplifiedLhs != lhs)
553  if (auto simplifiedLhsAsNonLoc = simplifiedLhs.getAs<NonLoc>()) {
554  lhs = *simplifiedLhsAsNonLoc;
555  continue;
556  }
557 
558  // Is the RHS a constant?
559  if (const llvm::APSInt *RHSValue = getKnownValue(state, rhs))
560  return MakeSymIntVal(Sym, op, *RHSValue, resultTy);
561 
562  // Give up -- this is not a symbolic expression we can handle.
563  return makeSymExprValNN(state, op, InputLHS, InputRHS, resultTy);
564  }
565  }
566  }
567 }
568 
570  const FieldRegion *RightFR,
572  QualType resultTy,
573  SimpleSValBuilder &SVB) {
574  // Only comparisons are meaningful here!
576  return UnknownVal();
577 
578  // Next, see if the two FRs have the same super-region.
579  // FIXME: This doesn't handle casts yet, and simply stripping the casts
580  // doesn't help.
581  if (LeftFR->getSuperRegion() != RightFR->getSuperRegion())
582  return UnknownVal();
583 
584  const FieldDecl *LeftFD = LeftFR->getDecl();
585  const FieldDecl *RightFD = RightFR->getDecl();
586  const RecordDecl *RD = LeftFD->getParent();
587 
588  // Make sure the two FRs are from the same kind of record. Just in case!
589  // FIXME: This is probably where inheritance would be a problem.
590  if (RD != RightFD->getParent())
591  return UnknownVal();
592 
593  // We know for sure that the two fields are not the same, since that
594  // would have given us the same SVal.
595  if (op == BO_EQ)
596  return SVB.makeTruthVal(false, resultTy);
597  if (op == BO_NE)
598  return SVB.makeTruthVal(true, resultTy);
599 
600  // Iterate through the fields and see which one comes first.
601  // [C99 6.7.2.1.13] "Within a structure object, the non-bit-field
602  // members and the units in which bit-fields reside have addresses that
603  // increase in the order in which they are declared."
604  bool leftFirst = (op == BO_LT || op == BO_LE);
605  for (const auto *I : RD->fields()) {
606  if (I == LeftFD)
607  return SVB.makeTruthVal(leftFirst, resultTy);
608  if (I == RightFD)
609  return SVB.makeTruthVal(!leftFirst, resultTy);
610  }
611 
612  llvm_unreachable("Fields not found in parent record's definition");
613 }
614 
615 // FIXME: all this logic will change if/when we have MemRegion::getLocation().
616 SVal SimpleSValBuilder::evalBinOpLL(ProgramStateRef state,
618  Loc lhs, Loc rhs,
619  QualType resultTy) {
620  // Only comparisons and subtractions are valid operations on two pointers.
621  // See [C99 6.5.5 through 6.5.14] or [C++0x 5.6 through 5.15].
622  // However, if a pointer is casted to an integer, evalBinOpNN may end up
623  // calling this function with another operation (PR7527). We don't attempt to
624  // model this for now, but it could be useful, particularly when the
625  // "location" is actually an integer value that's been passed through a void*.
626  if (!(BinaryOperator::isComparisonOp(op) || op == BO_Sub))
627  return UnknownVal();
628 
629  // Special cases for when both sides are identical.
630  if (lhs == rhs) {
631  switch (op) {
632  default:
633  llvm_unreachable("Unimplemented operation for two identical values");
634  case BO_Sub:
635  return makeZeroVal(resultTy);
636  case BO_EQ:
637  case BO_LE:
638  case BO_GE:
639  return makeTruthVal(true, resultTy);
640  case BO_NE:
641  case BO_LT:
642  case BO_GT:
643  return makeTruthVal(false, resultTy);
644  }
645  }
646 
647  switch (lhs.getSubKind()) {
648  default:
649  llvm_unreachable("Ordering not implemented for this Loc.");
650 
651  case loc::GotoLabelKind:
652  // The only thing we know about labels is that they're non-null.
653  if (rhs.isZeroConstant()) {
654  switch (op) {
655  default:
656  break;
657  case BO_Sub:
658  return evalCastFromLoc(lhs, resultTy);
659  case BO_EQ:
660  case BO_LE:
661  case BO_LT:
662  return makeTruthVal(false, resultTy);
663  case BO_NE:
664  case BO_GT:
665  case BO_GE:
666  return makeTruthVal(true, resultTy);
667  }
668  }
669  // There may be two labels for the same location, and a function region may
670  // have the same address as a label at the start of the function (depending
671  // on the ABI).
672  // FIXME: we can probably do a comparison against other MemRegions, though.
673  // FIXME: is there a way to tell if two labels refer to the same location?
674  return UnknownVal();
675 
676  case loc::ConcreteIntKind: {
677  // If one of the operands is a symbol and the other is a constant,
678  // build an expression for use by the constraint manager.
679  if (SymbolRef rSym = rhs.getAsLocSymbol()) {
680  // We can only build expressions with symbols on the left,
681  // so we need a reversible operator.
682  if (!BinaryOperator::isComparisonOp(op) || op == BO_Cmp)
683  return UnknownVal();
684 
685  const llvm::APSInt &lVal = lhs.castAs<loc::ConcreteInt>().getValue();
687  return makeNonLoc(rSym, op, lVal, resultTy);
688  }
689 
690  // If both operands are constants, just perform the operation.
692  SVal ResultVal =
693  lhs.castAs<loc::ConcreteInt>().evalBinOp(BasicVals, op, *rInt);
694  if (Optional<NonLoc> Result = ResultVal.getAs<NonLoc>())
695  return evalCastFromNonLoc(*Result, resultTy);
696 
697  assert(!ResultVal.getAs<Loc>() && "Loc-Loc ops should not produce Locs");
698  return UnknownVal();
699  }
700 
701  // Special case comparisons against NULL.
702  // This must come after the test if the RHS is a symbol, which is used to
703  // build constraints. The address of any non-symbolic region is guaranteed
704  // to be non-NULL, as is any label.
705  assert(rhs.getAs<loc::MemRegionVal>() || rhs.getAs<loc::GotoLabel>());
706  if (lhs.isZeroConstant()) {
707  switch (op) {
708  default:
709  break;
710  case BO_EQ:
711  case BO_GT:
712  case BO_GE:
713  return makeTruthVal(false, resultTy);
714  case BO_NE:
715  case BO_LT:
716  case BO_LE:
717  return makeTruthVal(true, resultTy);
718  }
719  }
720 
721  // Comparing an arbitrary integer to a region or label address is
722  // completely unknowable.
723  return UnknownVal();
724  }
725  case loc::MemRegionValKind: {
727  // If one of the operands is a symbol and the other is a constant,
728  // build an expression for use by the constraint manager.
729  if (SymbolRef lSym = lhs.getAsLocSymbol(true)) {
731  return MakeSymIntVal(lSym, op, rInt->getValue(), resultTy);
732  return UnknownVal();
733  }
734  // Special case comparisons to NULL.
735  // This must come after the test if the LHS is a symbol, which is used to
736  // build constraints. The address of any non-symbolic region is guaranteed
737  // to be non-NULL.
738  if (rInt->isZeroConstant()) {
739  if (op == BO_Sub)
740  return evalCastFromLoc(lhs, resultTy);
741 
743  QualType boolType = getContext().BoolTy;
744  NonLoc l = evalCastFromLoc(lhs, boolType).castAs<NonLoc>();
745  NonLoc r = makeTruthVal(false, boolType).castAs<NonLoc>();
746  return evalBinOpNN(state, op, l, r, resultTy);
747  }
748  }
749 
750  // Comparing a region to an arbitrary integer is completely unknowable.
751  return UnknownVal();
752  }
753 
754  // Get both values as regions, if possible.
755  const MemRegion *LeftMR = lhs.getAsRegion();
756  assert(LeftMR && "MemRegionValKind SVal doesn't have a region!");
757 
758  const MemRegion *RightMR = rhs.getAsRegion();
759  if (!RightMR)
760  // The RHS is probably a label, which in theory could address a region.
761  // FIXME: we can probably make a more useful statement about non-code
762  // regions, though.
763  return UnknownVal();
764 
765  const MemRegion *LeftBase = LeftMR->getBaseRegion();
766  const MemRegion *RightBase = RightMR->getBaseRegion();
767  const MemSpaceRegion *LeftMS = LeftBase->getMemorySpace();
768  const MemSpaceRegion *RightMS = RightBase->getMemorySpace();
769  const MemSpaceRegion *UnknownMS = MemMgr.getUnknownRegion();
770 
771  // If the two regions are from different known memory spaces they cannot be
772  // equal. Also, assume that no symbolic region (whose memory space is
773  // unknown) is on the stack.
774  if (LeftMS != RightMS &&
775  ((LeftMS != UnknownMS && RightMS != UnknownMS) ||
776  (isa<StackSpaceRegion>(LeftMS) || isa<StackSpaceRegion>(RightMS)))) {
777  switch (op) {
778  default:
779  return UnknownVal();
780  case BO_EQ:
781  return makeTruthVal(false, resultTy);
782  case BO_NE:
783  return makeTruthVal(true, resultTy);
784  }
785  }
786 
787  // If both values wrap regions, see if they're from different base regions.
788  // Note, heap base symbolic regions are assumed to not alias with
789  // each other; for example, we assume that malloc returns different address
790  // on each invocation.
791  // FIXME: ObjC object pointers always reside on the heap, but currently
792  // we treat their memory space as unknown, because symbolic pointers
793  // to ObjC objects may alias. There should be a way to construct
794  // possibly-aliasing heap-based regions. For instance, MacOSXApiChecker
795  // guesses memory space for ObjC object pointers manually instead of
796  // relying on us.
797  if (LeftBase != RightBase &&
798  ((!isa<SymbolicRegion>(LeftBase) && !isa<SymbolicRegion>(RightBase)) ||
799  (isa<HeapSpaceRegion>(LeftMS) || isa<HeapSpaceRegion>(RightMS))) ){
800  switch (op) {
801  default:
802  return UnknownVal();
803  case BO_EQ:
804  return makeTruthVal(false, resultTy);
805  case BO_NE:
806  return makeTruthVal(true, resultTy);
807  }
808  }
809 
810  // Handle special cases for when both regions are element regions.
811  const ElementRegion *RightER = dyn_cast<ElementRegion>(RightMR);
812  const ElementRegion *LeftER = dyn_cast<ElementRegion>(LeftMR);
813  if (RightER && LeftER) {
814  // Next, see if the two ERs have the same super-region and matching types.
815  // FIXME: This should do something useful even if the types don't match,
816  // though if both indexes are constant the RegionRawOffset path will
817  // give the correct answer.
818  if (LeftER->getSuperRegion() == RightER->getSuperRegion() &&
819  LeftER->getElementType() == RightER->getElementType()) {
820  // Get the left index and cast it to the correct type.
821  // If the index is unknown or undefined, bail out here.
822  SVal LeftIndexVal = LeftER->getIndex();
823  Optional<NonLoc> LeftIndex = LeftIndexVal.getAs<NonLoc>();
824  if (!LeftIndex)
825  return UnknownVal();
826  LeftIndexVal = evalCastFromNonLoc(*LeftIndex, ArrayIndexTy);
827  LeftIndex = LeftIndexVal.getAs<NonLoc>();
828  if (!LeftIndex)
829  return UnknownVal();
830 
831  // Do the same for the right index.
832  SVal RightIndexVal = RightER->getIndex();
833  Optional<NonLoc> RightIndex = RightIndexVal.getAs<NonLoc>();
834  if (!RightIndex)
835  return UnknownVal();
836  RightIndexVal = evalCastFromNonLoc(*RightIndex, ArrayIndexTy);
837  RightIndex = RightIndexVal.getAs<NonLoc>();
838  if (!RightIndex)
839  return UnknownVal();
840 
841  // Actually perform the operation.
842  // evalBinOpNN expects the two indexes to already be the right type.
843  return evalBinOpNN(state, op, *LeftIndex, *RightIndex, resultTy);
844  }
845  }
846 
847  // Special handling of the FieldRegions, even with symbolic offsets.
848  const FieldRegion *RightFR = dyn_cast<FieldRegion>(RightMR);
849  const FieldRegion *LeftFR = dyn_cast<FieldRegion>(LeftMR);
850  if (RightFR && LeftFR) {
851  SVal R = evalBinOpFieldRegionFieldRegion(LeftFR, RightFR, op, resultTy,
852  *this);
853  if (!R.isUnknown())
854  return R;
855  }
856 
857  // Compare the regions using the raw offsets.
858  RegionOffset LeftOffset = LeftMR->getAsOffset();
859  RegionOffset RightOffset = RightMR->getAsOffset();
860 
861  if (LeftOffset.getRegion() != nullptr &&
862  LeftOffset.getRegion() == RightOffset.getRegion() &&
863  !LeftOffset.hasSymbolicOffset() && !RightOffset.hasSymbolicOffset()) {
864  int64_t left = LeftOffset.getOffset();
865  int64_t right = RightOffset.getOffset();
866 
867  switch (op) {
868  default:
869  return UnknownVal();
870  case BO_LT:
871  return makeTruthVal(left < right, resultTy);
872  case BO_GT:
873  return makeTruthVal(left > right, resultTy);
874  case BO_LE:
875  return makeTruthVal(left <= right, resultTy);
876  case BO_GE:
877  return makeTruthVal(left >= right, resultTy);
878  case BO_EQ:
879  return makeTruthVal(left == right, resultTy);
880  case BO_NE:
881  return makeTruthVal(left != right, resultTy);
882  }
883  }
884 
885  // At this point we're not going to get a good answer, but we can try
886  // conjuring an expression instead.
887  SymbolRef LHSSym = lhs.getAsLocSymbol();
888  SymbolRef RHSSym = rhs.getAsLocSymbol();
889  if (LHSSym && RHSSym)
890  return makeNonLoc(LHSSym, op, RHSSym, resultTy);
891 
892  // If we get here, we have no way of comparing the regions.
893  return UnknownVal();
894  }
895  }
896 }
897 
898 SVal SimpleSValBuilder::evalBinOpLN(ProgramStateRef state,
900  Loc lhs, NonLoc rhs, QualType resultTy) {
901  if (op >= BO_PtrMemD && op <= BO_PtrMemI) {
902  if (auto PTMSV = rhs.getAs<nonloc::PointerToMember>()) {
903  if (PTMSV->isNullMemberPointer())
904  return UndefinedVal();
905  if (const FieldDecl *FD = PTMSV->getDeclAs<FieldDecl>()) {
906  SVal Result = lhs;
907 
908  for (const auto &I : *PTMSV)
909  Result = StateMgr.getStoreManager().evalDerivedToBase(
910  Result, I->getType(),I->isVirtual());
911  return state->getLValue(FD, Result);
912  }
913  }
914 
915  return rhs;
916  }
917 
918  assert(!BinaryOperator::isComparisonOp(op) &&
919  "arguments to comparison ops must be of the same type");
920 
921  // Special case: rhs is a zero constant.
922  if (rhs.isZeroConstant())
923  return lhs;
924 
925  // Perserve the null pointer so that it can be found by the DerefChecker.
926  if (lhs.isZeroConstant())
927  return lhs;
928 
929  // We are dealing with pointer arithmetic.
930 
931  // Handle pointer arithmetic on constant values.
933  if (Optional<loc::ConcreteInt> lhsInt = lhs.getAs<loc::ConcreteInt>()) {
934  const llvm::APSInt &leftI = lhsInt->getValue();
935  assert(leftI.isUnsigned());
936  llvm::APSInt rightI(rhsInt->getValue(), /* isUnsigned */ true);
937 
938  // Convert the bitwidth of rightI. This should deal with overflow
939  // since we are dealing with concrete values.
940  rightI = rightI.extOrTrunc(leftI.getBitWidth());
941 
942  // Offset the increment by the pointer size.
943  llvm::APSInt Multiplicand(rightI.getBitWidth(), /* isUnsigned */ true);
944  QualType pointeeType = resultTy->getPointeeType();
945  Multiplicand = getContext().getTypeSizeInChars(pointeeType).getQuantity();
946  rightI *= Multiplicand;
947 
948  // Compute the adjusted pointer.
949  switch (op) {
950  case BO_Add:
951  rightI = leftI + rightI;
952  break;
953  case BO_Sub:
954  rightI = leftI - rightI;
955  break;
956  default:
957  llvm_unreachable("Invalid pointer arithmetic operation");
958  }
959  return loc::ConcreteInt(getBasicValueFactory().getValue(rightI));
960  }
961  }
962 
963  // Handle cases where 'lhs' is a region.
964  if (const MemRegion *region = lhs.getAsRegion()) {
965  rhs = convertToArrayIndex(rhs).castAs<NonLoc>();
966  SVal index = UnknownVal();
967  const SubRegion *superR = nullptr;
968  // We need to know the type of the pointer in order to add an integer to it.
969  // Depending on the type, different amount of bytes is added.
970  QualType elementType;
971 
972  if (const ElementRegion *elemReg = dyn_cast<ElementRegion>(region)) {
973  assert(op == BO_Add || op == BO_Sub);
974  index = evalBinOpNN(state, op, elemReg->getIndex(), rhs,
975  getArrayIndexType());
976  superR = cast<SubRegion>(elemReg->getSuperRegion());
977  elementType = elemReg->getElementType();
978  }
979  else if (isa<SubRegion>(region)) {
980  assert(op == BO_Add || op == BO_Sub);
981  index = (op == BO_Add) ? rhs : evalMinus(rhs);
982  superR = cast<SubRegion>(region);
983  // TODO: Is this actually reliable? Maybe improving our MemRegion
984  // hierarchy to provide typed regions for all non-void pointers would be
985  // better. For instance, we cannot extend this towards LocAsInteger
986  // operations, where result type of the expression is integer.
987  if (resultTy->isAnyPointerType())
988  elementType = resultTy->getPointeeType();
989  }
990 
991  if (Optional<NonLoc> indexV = index.getAs<NonLoc>()) {
992  return loc::MemRegionVal(MemMgr.getElementRegion(elementType, *indexV,
993  superR, getContext()));
994  }
995  }
996  return UnknownVal();
997 }
998 
999 const llvm::APSInt *SimpleSValBuilder::getKnownValue(ProgramStateRef state,
1000  SVal V) {
1001  if (V.isUnknownOrUndef())
1002  return nullptr;
1003 
1005  return &X->getValue();
1006 
1008  return &X->getValue();
1009 
1010  if (SymbolRef Sym = V.getAsSymbol())
1011  return state->getConstraintManager().getSymVal(state, Sym);
1012 
1013  // FIXME: Add support for SymExprs.
1014  return nullptr;
1015 }
1016 
1017 SVal SimpleSValBuilder::simplifySVal(ProgramStateRef State, SVal V) {
1018  // For now, this function tries to constant-fold symbols inside a
1019  // nonloc::SymbolVal, and does nothing else. More simplifications should
1020  // be possible, such as constant-folding an index in an ElementRegion.
1021 
1022  class Simplifier : public FullSValVisitor<Simplifier, SVal> {
1024  SValBuilder &SVB;
1025 
1026  public:
1027  Simplifier(ProgramStateRef State)
1028  : State(State), SVB(State->getStateManager().getSValBuilder()) {}
1029 
1030  SVal VisitSymbolData(const SymbolData *S) {
1031  if (const llvm::APSInt *I =
1032  SVB.getKnownValue(State, nonloc::SymbolVal(S)))
1033  return Loc::isLocType(S->getType()) ? (SVal)SVB.makeIntLocVal(*I)
1034  : (SVal)SVB.makeIntVal(*I);
1035  return Loc::isLocType(S->getType()) ? (SVal)SVB.makeLoc(S)
1036  : nonloc::SymbolVal(S);
1037  }
1038 
1039  // TODO: Support SymbolCast. Support IntSymExpr when/if we actually
1040  // start producing them.
1041 
1042  SVal VisitSymIntExpr(const SymIntExpr *S) {
1043  SVal LHS = Visit(S->getLHS());
1044  SVal RHS;
1045  // By looking at the APSInt in the right-hand side of S, we cannot
1046  // figure out if it should be treated as a Loc or as a NonLoc.
1047  // So make our guess by recalling that we cannot multiply pointers
1048  // or compare a pointer to an integer.
1049  if (Loc::isLocType(S->getLHS()->getType()) &&
1051  // The usual conversion of $sym to &SymRegion{$sym}, as they have
1052  // the same meaning for Loc-type symbols, but the latter form
1053  // is preferred in SVal computations for being Loc itself.
1054  if (SymbolRef Sym = LHS.getAsSymbol()) {
1055  assert(Loc::isLocType(Sym->getType()));
1056  LHS = SVB.makeLoc(Sym);
1057  }
1058  RHS = SVB.makeIntLocVal(S->getRHS());
1059  } else {
1060  RHS = SVB.makeIntVal(S->getRHS());
1061  }
1062  return SVB.evalBinOp(State, S->getOpcode(), LHS, RHS, S->getType());
1063  }
1064 
1065  SVal VisitSymSymExpr(const SymSymExpr *S) {
1066  SVal LHS = Visit(S->getLHS());
1067  SVal RHS = Visit(S->getRHS());
1068  return SVB.evalBinOp(State, S->getOpcode(), LHS, RHS, S->getType());
1069  }
1070 
1071  SVal VisitSymExpr(SymbolRef S) { return nonloc::SymbolVal(S); }
1072 
1073  SVal VisitMemRegion(const MemRegion *R) { return loc::MemRegionVal(R); }
1074 
1075  SVal VisitNonLocSymbolVal(nonloc::SymbolVal V) {
1076  // Simplification is much more costly than computing complexity.
1077  // For high complexity, it may be not worth it.
1078  if (V.getSymbol()->computeComplexity() > 100)
1079  return V;
1080  return Visit(V.getSymbol());
1081  }
1082 
1083  SVal VisitSVal(SVal V) { return V; }
1084  };
1085 
1086  return Simplifier(State).Visit(V);
1087 }
An instance of this class is created to represent a function declaration or definition.
Definition: Decl.h:1697
nonloc::ConcreteInt makeIntVal(const IntegerLiteral *integer)
Definition: SValBuilder.h:254
CanQualType VoidPtrTy
Definition: ASTContext.h:1012
A (possibly-)qualified type.
Definition: Type.h:653
MemRegion - The root abstract class for all memory regions.
Definition: MemRegion.h:79
SValBuilder * createSimpleSValBuilder(llvm::BumpPtrAllocator &alloc, ASTContext &context, ProgramStateManager &stateMgr)
NonLoc getIndex() const
Definition: MemRegion.h:1085
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:456
const RecordDecl * getParent() const
getParent - Returns the parent of this field declaration, which is the struct in which this field is ...
Definition: Decl.h:2638
const MemRegion * getRegion() const
Definition: MemRegion.h:62
MemSpaceRegion - A memory region that represents a "memory space"; for example, the set of global var...
Definition: MemRegion.h:179
Value representing integer constant.
Definition: SVals.h:353
SymbolRef getAsLocSymbol(bool IncludeBaseRegions=false) const
If this SVal is a location and wraps a symbol, return that SymbolRef.
Definition: SVals.cpp:74
QualType getElementType() const
Definition: MemRegion.h:1091
bool isAdditiveOp() const
Definition: Expr.h:3062
Symbolic value.
Definition: SymExpr.h:29
const MemRegion * getSuperRegion() const
Definition: MemRegion.h:430
RecordDecl - Represents a struct/union/class.
Definition: Decl.h:3478
const PTMDataType getPTMData() const
Definition: SVals.h:493
const SymbolicRegion * getSymbolicBase() const
If this is a symbolic region, returns the region.
Definition: MemRegion.cpp:1141
static Opcode reverseComparisonOp(Opcode Opc)
Definition: Expr.h:3091
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:149
Value representing pointer-to-member.
Definition: SVals.h:487
LineState State
field_range fields() const
Definition: Decl.h:3609
const FieldDecl * getDecl() const
Definition: MemRegion.h:999
FieldDecl - An instance of this class is created by Sema::ActOnField to represent a member of a struc...
Definition: Decl.h:2457
bool isReferenceType() const
Definition: Type.h:5956
FullSValVisitor - a convenient mixed visitor for all three: SVal, SymExpr and MemRegion subclasses...
Definition: SValVisitor.h:138
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
const SymExpr * getAsSymbolicExpression() const
getAsSymbolicExpression - If this Sval wraps a symbolic expression then return that expression...
Definition: SVals.cpp:126
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6221
static bool isLocType(QualType T)
Definition: SVals.h:308
BinaryOperatorKind
bool isUnknown() const
Definition: SVals.h:125
loc::ConcreteInt makeIntLocVal(const llvm::APSInt &integer)
Definition: SValBuilder.h:270
A record of the "type" of an APSInt, used for conversions.
Definition: APSIntType.h:20
Represents a symbolic expression like &#39;x&#39; + 3.
Represent a region&#39;s offset within the top level base region.
Definition: MemRegion.h:47
const MemSpaceRegion * getMemorySpace() const
Definition: MemRegion.cpp:1061
virtual QualType getType() const =0
SymbolRef getAsSymbol(bool IncludeBaseRegions=false) const
If this SVal wraps a symbol return that SymbolRef.
Definition: SVals.cpp:116
static Opcode negateComparisonOp(Opcode Opc)
Definition: Expr.h:3078
unsigned getSubKind() const
Definition: SVals.h:108
Loc makeLoc(SymbolRef sym)
Definition: SValBuilder.h:329
SymbolicRegion - A special, "non-concrete" region.
Definition: MemRegion.h:742
const FunctionProtoType * T
static SVal getValue(SVal val, SValBuilder &svalBuilder)
SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, SVal lhs, SVal rhs, QualType type)
bool isUnionType() const
Definition: Type.cpp:432
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:100
bool isComparisonOp() const
Definition: Expr.h:3076
const SymExpr * getLHS() const
FunctionCodeRegion - A region that represents code texts of function.
Definition: MemRegion.h:563
const MemRegion * getAsRegion() const
Definition: SVals.cpp:140
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:63
bool isSignedIntegerOrEnumerationType() const
Determines whether this is an integer type that is signed or an enumeration types whose underlying ty...
Definition: Type.cpp:1816
bool isAnyPointerType() const
Definition: Type.h:5948
QualType getType() const override
llvm::APSInt convert(const llvm::APSInt &Value) const LLVM_READONLY
Convert and return a new APSInt with the given value, but this type&#39;s bit width and signedness...
Definition: APSIntType.h:49
Dataflow Directional Tag Classes.
bool isZeroConstant() const
Definition: SVals.cpp:219
bool isShiftOp() const
Definition: Expr.h:3064
const llvm::APSInt & getRHS() const
bool isBooleanType() const
Definition: Type.h:6234
Represents symbolic expression.
Definition: SVals.h:327
unsigned computeComplexity() const
const SymExpr * getRHS() const
unsigned getIntWidth(QualType T) const
T castAs() const
Convert to the specified SVal type, asserting that this SVal is of the desired type.
Definition: SVals.h:92
SubRegion - A region that subsets another larger region.
Definition: MemRegion.h:419
SymbolRef getSymbol() const
Definition: SVals.h:332
RegionOffset getAsOffset() const
Compute the offset within the top level memory object.
Definition: MemRegion.cpp:1210
int64_t getOffset() const
Definition: MemRegion.h:66
char __ovld __cnfn max(char x, char y)
Returns y if x < y, otherwise it returns x.
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2007
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2174
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13010
BinaryOperator::Opcode getOpcode() const
void apply(llvm::APSInt &Value) const
Convert a given APSInt, in place, to match this type.
Definition: APSIntType.h:38
const MemRegion * getBaseRegion() const
Definition: MemRegion.cpp:1093
ElementRegin is used to represent both array elements and casts.
Definition: MemRegion.h:1066
virtual const llvm::APSInt * getKnownValue(ProgramStateRef state, SVal val)=0
Evaluates a given SVal.
Represents a symbolic expression like &#39;x&#39; + &#39;y&#39;.
bool hasSymbolicOffset() const
Definition: MemRegion.h:64
bool isUnknownOrUndef() const
Definition: SVals.h:133
A symbol representing data which can be stored in a memory location (region).
Definition: SymExpr.h:113
const SymExpr * getLHS() const
static SVal evalBinOpFieldRegionFieldRegion(const FieldRegion *LeftFR, const FieldRegion *RightFR, BinaryOperator::Opcode op, QualType resultTy, SimpleSValBuilder &SVB)