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RangeConstraintManager.cpp
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1 //== RangeConstraintManager.cpp - Manage range constraints.------*- 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 RangeConstraintManager, a class that tracks simple
11 // equality and inequality constraints on symbolic values of ProgramState.
12 //
13 //===----------------------------------------------------------------------===//
14 
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/ImmutableSet.h"
21 #include "llvm/Support/raw_ostream.h"
22 
23 using namespace clang;
24 using namespace ento;
25 
26 void RangeSet::IntersectInRange(BasicValueFactory &BV, Factory &F,
27  const llvm::APSInt &Lower, const llvm::APSInt &Upper,
28  PrimRangeSet &newRanges, PrimRangeSet::iterator &i,
29  PrimRangeSet::iterator &e) const {
30  // There are six cases for each range R in the set:
31  // 1. R is entirely before the intersection range.
32  // 2. R is entirely after the intersection range.
33  // 3. R contains the entire intersection range.
34  // 4. R starts before the intersection range and ends in the middle.
35  // 5. R starts in the middle of the intersection range and ends after it.
36  // 6. R is entirely contained in the intersection range.
37  // These correspond to each of the conditions below.
38  for (/* i = begin(), e = end() */; i != e; ++i) {
39  if (i->To() < Lower) {
40  continue;
41  }
42  if (i->From() > Upper) {
43  break;
44  }
45 
46  if (i->Includes(Lower)) {
47  if (i->Includes(Upper)) {
48  newRanges =
49  F.add(newRanges, Range(BV.getValue(Lower), BV.getValue(Upper)));
50  break;
51  } else
52  newRanges = F.add(newRanges, Range(BV.getValue(Lower), i->To()));
53  } else {
54  if (i->Includes(Upper)) {
55  newRanges = F.add(newRanges, Range(i->From(), BV.getValue(Upper)));
56  break;
57  } else
58  newRanges = F.add(newRanges, *i);
59  }
60  }
61 }
62 
63 const llvm::APSInt &RangeSet::getMinValue() const {
64  assert(!isEmpty());
65  return ranges.begin()->From();
66 }
67 
68 bool RangeSet::pin(llvm::APSInt &Lower, llvm::APSInt &Upper) const {
69  // This function has nine cases, the cartesian product of range-testing
70  // both the upper and lower bounds against the symbol's type.
71  // Each case requires a different pinning operation.
72  // The function returns false if the described range is entirely outside
73  // the range of values for the associated symbol.
74  APSIntType Type(getMinValue());
75  APSIntType::RangeTestResultKind LowerTest = Type.testInRange(Lower, true);
76  APSIntType::RangeTestResultKind UpperTest = Type.testInRange(Upper, true);
77 
78  switch (LowerTest) {
80  switch (UpperTest) {
82  // The entire range is outside the symbol's set of possible values.
83  // If this is a conventionally-ordered range, the state is infeasible.
84  if (Lower <= Upper)
85  return false;
86 
87  // However, if the range wraps around, it spans all possible values.
88  Lower = Type.getMinValue();
89  Upper = Type.getMaxValue();
90  break;
92  // The range starts below what's possible but ends within it. Pin.
93  Lower = Type.getMinValue();
94  Type.apply(Upper);
95  break;
97  // The range spans all possible values for the symbol. Pin.
98  Lower = Type.getMinValue();
99  Upper = Type.getMaxValue();
100  break;
101  }
102  break;
104  switch (UpperTest) {
106  // The range wraps around, but all lower values are not possible.
107  Type.apply(Lower);
108  Upper = Type.getMaxValue();
109  break;
111  // The range may or may not wrap around, but both limits are valid.
112  Type.apply(Lower);
113  Type.apply(Upper);
114  break;
116  // The range starts within what's possible but ends above it. Pin.
117  Type.apply(Lower);
118  Upper = Type.getMaxValue();
119  break;
120  }
121  break;
123  switch (UpperTest) {
125  // The range wraps but is outside the symbol's set of possible values.
126  return false;
128  // The range starts above what's possible but ends within it (wrap).
129  Lower = Type.getMinValue();
130  Type.apply(Upper);
131  break;
133  // The entire range is outside the symbol's set of possible values.
134  // If this is a conventionally-ordered range, the state is infeasible.
135  if (Lower <= Upper)
136  return false;
137 
138  // However, if the range wraps around, it spans all possible values.
139  Lower = Type.getMinValue();
140  Upper = Type.getMaxValue();
141  break;
142  }
143  break;
144  }
145 
146  return true;
147 }
148 
149 // Returns a set containing the values in the receiving set, intersected with
150 // the closed range [Lower, Upper]. Unlike the Range type, this range uses
151 // modular arithmetic, corresponding to the common treatment of C integer
152 // overflow. Thus, if the Lower bound is greater than the Upper bound, the
153 // range is taken to wrap around. This is equivalent to taking the
154 // intersection with the two ranges [Min, Upper] and [Lower, Max],
155 // or, alternatively, /removing/ all integers between Upper and Lower.
157  llvm::APSInt Lower, llvm::APSInt Upper) const {
158  if (!pin(Lower, Upper))
159  return F.getEmptySet();
160 
161  PrimRangeSet newRanges = F.getEmptySet();
162 
163  PrimRangeSet::iterator i = begin(), e = end();
164  if (Lower <= Upper)
165  IntersectInRange(BV, F, Lower, Upper, newRanges, i, e);
166  else {
167  // The order of the next two statements is important!
168  // IntersectInRange() does not reset the iteration state for i and e.
169  // Therefore, the lower range most be handled first.
170  IntersectInRange(BV, F, BV.getMinValue(Upper), Upper, newRanges, i, e);
171  IntersectInRange(BV, F, Lower, BV.getMaxValue(Lower), newRanges, i, e);
172  }
173 
174  return newRanges;
175 }
176 
177 void RangeSet::print(raw_ostream &os) const {
178  bool isFirst = true;
179  os << "{ ";
180  for (iterator i = begin(), e = end(); i != e; ++i) {
181  if (isFirst)
182  isFirst = false;
183  else
184  os << ", ";
185 
186  os << '[' << i->From().toString(10) << ", " << i->To().toString(10)
187  << ']';
188  }
189  os << " }";
190 }
191 
192 namespace {
193 class RangeConstraintManager : public RangedConstraintManager {
194 public:
195  RangeConstraintManager(SubEngine *SE, SValBuilder &SVB)
196  : RangedConstraintManager(SE, SVB) {}
197 
198  //===------------------------------------------------------------------===//
199  // Implementation for interface from ConstraintManager.
200  //===------------------------------------------------------------------===//
201 
202  bool canReasonAbout(SVal X) const override;
203 
204  ConditionTruthVal checkNull(ProgramStateRef State, SymbolRef Sym) override;
205 
206  const llvm::APSInt *getSymVal(ProgramStateRef State,
207  SymbolRef Sym) const override;
208 
209  ProgramStateRef removeDeadBindings(ProgramStateRef State,
210  SymbolReaper &SymReaper) override;
211 
212  void print(ProgramStateRef State, raw_ostream &Out, const char *nl,
213  const char *sep) override;
214 
215  //===------------------------------------------------------------------===//
216  // Implementation for interface from RangedConstraintManager.
217  //===------------------------------------------------------------------===//
218 
219  ProgramStateRef assumeSymNE(ProgramStateRef State, SymbolRef Sym,
220  const llvm::APSInt &V,
221  const llvm::APSInt &Adjustment) override;
222 
223  ProgramStateRef assumeSymEQ(ProgramStateRef State, SymbolRef Sym,
224  const llvm::APSInt &V,
225  const llvm::APSInt &Adjustment) override;
226 
227  ProgramStateRef assumeSymLT(ProgramStateRef State, SymbolRef Sym,
228  const llvm::APSInt &V,
229  const llvm::APSInt &Adjustment) override;
230 
231  ProgramStateRef assumeSymGT(ProgramStateRef State, SymbolRef Sym,
232  const llvm::APSInt &V,
233  const llvm::APSInt &Adjustment) override;
234 
235  ProgramStateRef assumeSymLE(ProgramStateRef State, SymbolRef Sym,
236  const llvm::APSInt &V,
237  const llvm::APSInt &Adjustment) override;
238 
239  ProgramStateRef assumeSymGE(ProgramStateRef State, SymbolRef Sym,
240  const llvm::APSInt &V,
241  const llvm::APSInt &Adjustment) override;
242 
243  ProgramStateRef assumeSymWithinInclusiveRange(
244  ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
245  const llvm::APSInt &To, const llvm::APSInt &Adjustment) override;
246 
247  ProgramStateRef assumeSymOutsideInclusiveRange(
248  ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
249  const llvm::APSInt &To, const llvm::APSInt &Adjustment) override;
250 
251 private:
253 
254  RangeSet getRange(ProgramStateRef State, SymbolRef Sym);
255 
256  RangeSet getSymLTRange(ProgramStateRef St, SymbolRef Sym,
257  const llvm::APSInt &Int,
258  const llvm::APSInt &Adjustment);
259  RangeSet getSymGTRange(ProgramStateRef St, SymbolRef Sym,
260  const llvm::APSInt &Int,
261  const llvm::APSInt &Adjustment);
262  RangeSet getSymLERange(ProgramStateRef St, SymbolRef Sym,
263  const llvm::APSInt &Int,
264  const llvm::APSInt &Adjustment);
265  RangeSet getSymLERange(llvm::function_ref<RangeSet()> RS,
266  const llvm::APSInt &Int,
267  const llvm::APSInt &Adjustment);
268  RangeSet getSymGERange(ProgramStateRef St, SymbolRef Sym,
269  const llvm::APSInt &Int,
270  const llvm::APSInt &Adjustment);
271 };
272 
273 } // end anonymous namespace
274 
275 std::unique_ptr<ConstraintManager>
277  return llvm::make_unique<RangeConstraintManager>(Eng, StMgr.getSValBuilder());
278 }
279 
280 bool RangeConstraintManager::canReasonAbout(SVal X) const {
282  if (SymVal && SymVal->isExpression()) {
283  const SymExpr *SE = SymVal->getSymbol();
284 
285  if (const SymIntExpr *SIE = dyn_cast<SymIntExpr>(SE)) {
286  switch (SIE->getOpcode()) {
287  // We don't reason yet about bitwise-constraints on symbolic values.
288  case BO_And:
289  case BO_Or:
290  case BO_Xor:
291  return false;
292  // We don't reason yet about these arithmetic constraints on
293  // symbolic values.
294  case BO_Mul:
295  case BO_Div:
296  case BO_Rem:
297  case BO_Shl:
298  case BO_Shr:
299  return false;
300  // All other cases.
301  default:
302  return true;
303  }
304  }
305 
306  if (const SymSymExpr *SSE = dyn_cast<SymSymExpr>(SE)) {
307  // FIXME: Handle <=> here.
308  if (BinaryOperator::isEqualityOp(SSE->getOpcode()) ||
309  BinaryOperator::isRelationalOp(SSE->getOpcode())) {
310  // We handle Loc <> Loc comparisons, but not (yet) NonLoc <> NonLoc.
311  if (Loc::isLocType(SSE->getLHS()->getType())) {
312  assert(Loc::isLocType(SSE->getRHS()->getType()));
313  return true;
314  }
315  }
316  }
317 
318  return false;
319  }
320 
321  return true;
322 }
323 
324 ConditionTruthVal RangeConstraintManager::checkNull(ProgramStateRef State,
325  SymbolRef Sym) {
326  const RangeSet *Ranges = State->get<ConstraintRange>(Sym);
327 
328  // If we don't have any information about this symbol, it's underconstrained.
329  if (!Ranges)
330  return ConditionTruthVal();
331 
332  // If we have a concrete value, see if it's zero.
333  if (const llvm::APSInt *Value = Ranges->getConcreteValue())
334  return *Value == 0;
335 
336  BasicValueFactory &BV = getBasicVals();
337  APSIntType IntType = BV.getAPSIntType(Sym->getType());
338  llvm::APSInt Zero = IntType.getZeroValue();
339 
340  // Check if zero is in the set of possible values.
341  if (Ranges->Intersect(BV, F, Zero, Zero).isEmpty())
342  return false;
343 
344  // Zero is a possible value, but it is not the /only/ possible value.
345  return ConditionTruthVal();
346 }
347 
348 const llvm::APSInt *RangeConstraintManager::getSymVal(ProgramStateRef St,
349  SymbolRef Sym) const {
350  const ConstraintRangeTy::data_type *T = St->get<ConstraintRange>(Sym);
351  return T ? T->getConcreteValue() : nullptr;
352 }
353 
354 /// Scan all symbols referenced by the constraints. If the symbol is not alive
355 /// as marked in LSymbols, mark it as dead in DSymbols.
357 RangeConstraintManager::removeDeadBindings(ProgramStateRef State,
358  SymbolReaper &SymReaper) {
359  bool Changed = false;
360  ConstraintRangeTy CR = State->get<ConstraintRange>();
361  ConstraintRangeTy::Factory &CRFactory = State->get_context<ConstraintRange>();
362 
363  for (ConstraintRangeTy::iterator I = CR.begin(), E = CR.end(); I != E; ++I) {
364  SymbolRef Sym = I.getKey();
365  if (SymReaper.maybeDead(Sym)) {
366  Changed = true;
367  CR = CRFactory.remove(CR, Sym);
368  }
369  }
370 
371  return Changed ? State->set<ConstraintRange>(CR) : State;
372 }
373 
374 /// Return a range set subtracting zero from \p Domain.
376  BasicValueFactory &BV,
378  SymbolRef Sym,
379  RangeSet Domain) {
380  APSIntType IntType = BV.getAPSIntType(Sym->getType());
381  return Domain.Intersect(BV, F, ++IntType.getZeroValue(),
382  --IntType.getZeroValue());
383 }
384 
385 /// Apply implicit constraints for bitwise OR- and AND-.
386 /// For unsigned types, bitwise OR with a constant always returns
387 /// a value greater-or-equal than the constant, and bitwise AND
388 /// returns a value less-or-equal then the constant.
389 ///
390 /// Pattern matches the expression \p Sym against those rule,
391 /// and applies the required constraints.
392 /// \p Input Previously established expression range set
394  BasicValueFactory &BV,
396  RangeSet Input,
397  const SymIntExpr* SIE) {
398  QualType T = SIE->getType();
399  bool IsUnsigned = T->isUnsignedIntegerType();
400  const llvm::APSInt &RHS = SIE->getRHS();
401  const llvm::APSInt &Zero = BV.getAPSIntType(T).getZeroValue();
402  BinaryOperator::Opcode Operator = SIE->getOpcode();
403 
404  // For unsigned types, the output of bitwise-or is bigger-or-equal than RHS.
405  if (Operator == BO_Or && IsUnsigned)
406  return Input.Intersect(BV, F, RHS, BV.getMaxValue(T));
407 
408  // Bitwise-or with a non-zero constant is always non-zero.
409  if (Operator == BO_Or && RHS != Zero)
410  return assumeNonZero(BV, F, SIE, Input);
411 
412  // For unsigned types, or positive RHS,
413  // bitwise-and output is always smaller-or-equal than RHS (assuming two's
414  // complement representation of signed types).
415  if (Operator == BO_And && (IsUnsigned || RHS >= Zero))
416  return Input.Intersect(BV, F, BV.getMinValue(T), RHS);
417 
418  return Input;
419 }
420 
421 RangeSet RangeConstraintManager::getRange(ProgramStateRef State,
422  SymbolRef Sym) {
423  if (ConstraintRangeTy::data_type *V = State->get<ConstraintRange>(Sym))
424  return *V;
425 
426  // Lazily generate a new RangeSet representing all possible values for the
427  // given symbol type.
428  BasicValueFactory &BV = getBasicVals();
429  QualType T = Sym->getType();
430 
431  RangeSet Result(F, BV.getMinValue(T), BV.getMaxValue(T));
432 
433  // References are known to be non-zero.
434  if (T->isReferenceType())
435  return assumeNonZero(BV, F, Sym, Result);
436 
437  // Known constraints on ranges of bitwise expressions.
438  if (const SymIntExpr* SIE = dyn_cast<SymIntExpr>(Sym))
439  return applyBitwiseConstraints(BV, F, Result, SIE);
440 
441  return Result;
442 }
443 
444 //===------------------------------------------------------------------------===
445 // assumeSymX methods: protected interface for RangeConstraintManager.
446 //===------------------------------------------------------------------------===/
447 
448 // The syntax for ranges below is mathematical, using [x, y] for closed ranges
449 // and (x, y) for open ranges. These ranges are modular, corresponding with
450 // a common treatment of C integer overflow. This means that these methods
451 // do not have to worry about overflow; RangeSet::Intersect can handle such a
452 // "wraparound" range.
453 // As an example, the range [UINT_MAX-1, 3) contains five values: UINT_MAX-1,
454 // UINT_MAX, 0, 1, and 2.
455 
457 RangeConstraintManager::assumeSymNE(ProgramStateRef St, SymbolRef Sym,
458  const llvm::APSInt &Int,
459  const llvm::APSInt &Adjustment) {
460  // Before we do any real work, see if the value can even show up.
461  APSIntType AdjustmentType(Adjustment);
462  if (AdjustmentType.testInRange(Int, true) != APSIntType::RTR_Within)
463  return St;
464 
465  llvm::APSInt Lower = AdjustmentType.convert(Int) - Adjustment;
466  llvm::APSInt Upper = Lower;
467  --Lower;
468  ++Upper;
469 
470  // [Int-Adjustment+1, Int-Adjustment-1]
471  // Notice that the lower bound is greater than the upper bound.
472  RangeSet New = getRange(St, Sym).Intersect(getBasicVals(), F, Upper, Lower);
473  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
474 }
475 
477 RangeConstraintManager::assumeSymEQ(ProgramStateRef St, SymbolRef Sym,
478  const llvm::APSInt &Int,
479  const llvm::APSInt &Adjustment) {
480  // Before we do any real work, see if the value can even show up.
481  APSIntType AdjustmentType(Adjustment);
482  if (AdjustmentType.testInRange(Int, true) != APSIntType::RTR_Within)
483  return nullptr;
484 
485  // [Int-Adjustment, Int-Adjustment]
486  llvm::APSInt AdjInt = AdjustmentType.convert(Int) - Adjustment;
487  RangeSet New = getRange(St, Sym).Intersect(getBasicVals(), F, AdjInt, AdjInt);
488  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
489 }
490 
491 RangeSet RangeConstraintManager::getSymLTRange(ProgramStateRef St,
492  SymbolRef Sym,
493  const llvm::APSInt &Int,
494  const llvm::APSInt &Adjustment) {
495  // Before we do any real work, see if the value can even show up.
496  APSIntType AdjustmentType(Adjustment);
497  switch (AdjustmentType.testInRange(Int, true)) {
499  return F.getEmptySet();
501  break;
503  return getRange(St, Sym);
504  }
505 
506  // Special case for Int == Min. This is always false.
507  llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
508  llvm::APSInt Min = AdjustmentType.getMinValue();
509  if (ComparisonVal == Min)
510  return F.getEmptySet();
511 
512  llvm::APSInt Lower = Min - Adjustment;
513  llvm::APSInt Upper = ComparisonVal - Adjustment;
514  --Upper;
515 
516  return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
517 }
518 
520 RangeConstraintManager::assumeSymLT(ProgramStateRef St, SymbolRef Sym,
521  const llvm::APSInt &Int,
522  const llvm::APSInt &Adjustment) {
523  RangeSet New = getSymLTRange(St, Sym, Int, Adjustment);
524  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
525 }
526 
527 RangeSet RangeConstraintManager::getSymGTRange(ProgramStateRef St,
528  SymbolRef Sym,
529  const llvm::APSInt &Int,
530  const llvm::APSInt &Adjustment) {
531  // Before we do any real work, see if the value can even show up.
532  APSIntType AdjustmentType(Adjustment);
533  switch (AdjustmentType.testInRange(Int, true)) {
535  return getRange(St, Sym);
537  break;
539  return F.getEmptySet();
540  }
541 
542  // Special case for Int == Max. This is always false.
543  llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
544  llvm::APSInt Max = AdjustmentType.getMaxValue();
545  if (ComparisonVal == Max)
546  return F.getEmptySet();
547 
548  llvm::APSInt Lower = ComparisonVal - Adjustment;
549  llvm::APSInt Upper = Max - Adjustment;
550  ++Lower;
551 
552  return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
553 }
554 
556 RangeConstraintManager::assumeSymGT(ProgramStateRef St, SymbolRef Sym,
557  const llvm::APSInt &Int,
558  const llvm::APSInt &Adjustment) {
559  RangeSet New = getSymGTRange(St, Sym, Int, Adjustment);
560  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
561 }
562 
563 RangeSet RangeConstraintManager::getSymGERange(ProgramStateRef St,
564  SymbolRef Sym,
565  const llvm::APSInt &Int,
566  const llvm::APSInt &Adjustment) {
567  // Before we do any real work, see if the value can even show up.
568  APSIntType AdjustmentType(Adjustment);
569  switch (AdjustmentType.testInRange(Int, true)) {
571  return getRange(St, Sym);
573  break;
575  return F.getEmptySet();
576  }
577 
578  // Special case for Int == Min. This is always feasible.
579  llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
580  llvm::APSInt Min = AdjustmentType.getMinValue();
581  if (ComparisonVal == Min)
582  return getRange(St, Sym);
583 
584  llvm::APSInt Max = AdjustmentType.getMaxValue();
585  llvm::APSInt Lower = ComparisonVal - Adjustment;
586  llvm::APSInt Upper = Max - Adjustment;
587 
588  return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
589 }
590 
592 RangeConstraintManager::assumeSymGE(ProgramStateRef St, SymbolRef Sym,
593  const llvm::APSInt &Int,
594  const llvm::APSInt &Adjustment) {
595  RangeSet New = getSymGERange(St, Sym, Int, Adjustment);
596  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
597 }
598 
599 RangeSet RangeConstraintManager::getSymLERange(
600  llvm::function_ref<RangeSet()> RS,
601  const llvm::APSInt &Int,
602  const llvm::APSInt &Adjustment) {
603  // Before we do any real work, see if the value can even show up.
604  APSIntType AdjustmentType(Adjustment);
605  switch (AdjustmentType.testInRange(Int, true)) {
607  return F.getEmptySet();
609  break;
611  return RS();
612  }
613 
614  // Special case for Int == Max. This is always feasible.
615  llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
616  llvm::APSInt Max = AdjustmentType.getMaxValue();
617  if (ComparisonVal == Max)
618  return RS();
619 
620  llvm::APSInt Min = AdjustmentType.getMinValue();
621  llvm::APSInt Lower = Min - Adjustment;
622  llvm::APSInt Upper = ComparisonVal - Adjustment;
623 
624  return RS().Intersect(getBasicVals(), F, Lower, Upper);
625 }
626 
627 RangeSet RangeConstraintManager::getSymLERange(ProgramStateRef St,
628  SymbolRef Sym,
629  const llvm::APSInt &Int,
630  const llvm::APSInt &Adjustment) {
631  return getSymLERange([&] { return getRange(St, Sym); }, Int, Adjustment);
632 }
633 
635 RangeConstraintManager::assumeSymLE(ProgramStateRef St, SymbolRef Sym,
636  const llvm::APSInt &Int,
637  const llvm::APSInt &Adjustment) {
638  RangeSet New = getSymLERange(St, Sym, Int, Adjustment);
639  return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
640 }
641 
642 ProgramStateRef RangeConstraintManager::assumeSymWithinInclusiveRange(
643  ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
644  const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
645  RangeSet New = getSymGERange(State, Sym, From, Adjustment);
646  if (New.isEmpty())
647  return nullptr;
648  RangeSet Out = getSymLERange([&] { return New; }, To, Adjustment);
649  return Out.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, Out);
650 }
651 
652 ProgramStateRef RangeConstraintManager::assumeSymOutsideInclusiveRange(
653  ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
654  const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
655  RangeSet RangeLT = getSymLTRange(State, Sym, From, Adjustment);
656  RangeSet RangeGT = getSymGTRange(State, Sym, To, Adjustment);
657  RangeSet New(RangeLT.addRange(F, RangeGT));
658  return New.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, New);
659 }
660 
661 //===------------------------------------------------------------------------===
662 // Pretty-printing.
663 //===------------------------------------------------------------------------===/
664 
665 void RangeConstraintManager::print(ProgramStateRef St, raw_ostream &Out,
666  const char *nl, const char *sep) {
667 
668  ConstraintRangeTy Ranges = St->get<ConstraintRange>();
669 
670  if (Ranges.isEmpty()) {
671  Out << nl << sep << "Ranges are empty." << nl;
672  return;
673  }
674 
675  Out << nl << sep << "Ranges of symbol values:";
676  for (ConstraintRangeTy::iterator I = Ranges.begin(), E = Ranges.end(); I != E;
677  ++I) {
678  Out << nl << ' ' << I.getKey() << " : ";
679  I.getData().print(Out);
680  }
681  Out << nl;
682 }
A (possibly-)qualified type.
Definition: Type.h:655
Value is less than the minimum representable value.
Definition: APSIntType.h:78
bool maybeDead(SymbolRef sym)
If a symbol is known to be live, marks the symbol as live.
std::unique_ptr< ConstraintManager > CreateRangeConstraintManager(ProgramStateManager &statemgr, SubEngine *subengine)
The base class of the type hierarchy.
Definition: Type.h:1421
A Range represents the closed range [from, to].
llvm::ImmutableMap< SymbolRef, RangeSet > ConstraintRangeTy
bool isUnsignedIntegerType() const
Return true if this is an integer type that is unsigned, according to C99 6.2.5p6 [which returns true...
Definition: Type.cpp:1847
RangeSet contains a set of ranges.
bool isEqualityOp() const
Definition: Expr.h:3153
Symbolic value.
Definition: SymExpr.h:30
LineState State
RangeSet addRange(Factory &F, const RangeSet &RS)
Create a new set with all ranges of this set and RS.
bool isReferenceType() const
Definition: Type.h:6061
static bool isLocType(QualType T)
Definition: SVals.h:327
BinaryOperatorKind
PrimRangeSet::Factory Factory
Value is representable using this type.
Definition: APSIntType.h:79
A record of the "type" of an APSInt, used for conversions.
Definition: APSIntType.h:20
Represents a symbolic expression like &#39;x&#39; + 3.
bool isRelationalOp() const
Definition: Expr.h:3150
RangeTestResultKind testInRange(const llvm::APSInt &Val, bool AllowMixedSign) const LLVM_READONLY
Tests whether a given value is losslessly representable using this type.
Definition: APSIntType.cpp:16
llvm::APSInt getZeroValue() const LLVM_READONLY
Returns an all-zero value for this type.
Definition: APSIntType.h:56
virtual QualType getType() const =0
void print(raw_ostream &os) const
llvm::APSInt getMinValue() const LLVM_READONLY
Returns the minimum value for this type.
Definition: APSIntType.h:61
const FunctionProtoType * T
const llvm::APSInt * getConcreteValue() const
getConcreteValue - If a symbol is contrained to equal a specific integer constant then this method re...
static RangeSet assumeNonZero(BasicValueFactory &BV, RangeSet::Factory &F, SymbolRef Sym, RangeSet Domain)
Return a range set subtracting zero from Domain.
Optional< T > getAs() const
Convert to the specified SVal type, returning None if this SVal is not of the desired type...
Definition: SVals.h:112
llvm::APSInt getMaxValue() const LLVM_READONLY
Returns the maximum value for this type.
Definition: APSIntType.h:66
SVal - This represents a symbolic expression, which can be either an L-value or an R-value...
Definition: SVals.h:76
QualType getType() const override
A class responsible for cleaning up unused symbols.
Value is greater than the maximum representable value.
Definition: APSIntType.h:80
RangeTestResultKind
Used to classify whether a value is representable using this type.
Definition: APSIntType.h:77
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.
const llvm::APSInt & getRHS() const
Represents symbolic expression.
Definition: SVals.h:347
const llvm::APSInt & getMinValue(const llvm::APSInt &v)
APSIntType getAPSIntType(QualType T) const
Returns the type of the APSInt used to store values of the given QualType.
RangeSet Intersect(BasicValueFactory &BV, Factory &F, llvm::APSInt Lower, llvm::APSInt Upper) const
PrimRangeSet::iterator iterator
static RangeSet applyBitwiseConstraints(BasicValueFactory &BV, RangeSet::Factory &F, RangeSet Input, const SymIntExpr *SIE)
Apply implicit constraints for bitwise OR- and AND-.
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13462
BinaryOperator::Opcode getOpcode() const
const llvm::APSInt & getMaxValue(const llvm::APSInt &v)
Represents a symbolic expression like &#39;x&#39; + &#39;y&#39;.