Coverage Report

Created: 2021-04-17 09:42

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
Line
Count
Source (jump to first uncovered line)
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"
15
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
16
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.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.
28
static SVal conjureOffsetSymbolOnLocation(
29
    SVal Symbol, SVal Other, Expr* Expression, SValBuilder &svalBuilder,
30
25.5k
    unsigned Count, const LocationContext *LCtx) {
31
25.5k
  QualType Ty = Expression->getType();
32
25.5k
  if (Other.getAs<Loc>() &&
33
25.5k
      
Ty->isIntegralOrEnumerationType()10.1k
&&
34
25.5k
      
Symbol.isUnknown()10.0k
) {
35
0
    return svalBuilder.conjureSymbolVal(Expression, LCtx, Ty, Count);
36
0
  }
37
25.5k
  return Symbol;
38
25.5k
}
39
40
void ExprEngine::VisitBinaryOperator(const BinaryOperator* B,
41
                                     ExplodedNode *Pred,
42
73.1k
                                     ExplodedNodeSet &Dst) {
43
44
73.1k
  Expr *LHS = B->getLHS()->IgnoreParens();
45
73.1k
  Expr *RHS = B->getRHS()->IgnoreParens();
46
47
  // FIXME: Prechecks eventually go in ::Visit().
48
73.1k
  ExplodedNodeSet CheckedSet;
49
73.1k
  ExplodedNodeSet Tmp2;
50
73.1k
  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, B, *this);
51
52
  // With both the LHS and RHS evaluated, process the operation itself.
53
73.1k
  for (ExplodedNodeSet::iterator it=CheckedSet.begin(), ei=CheckedSet.end();
54
146k
         it != ei; 
++it72.9k
) {
55
56
72.9k
    ProgramStateRef state = (*it)->getState();
57
72.9k
    const LocationContext *LCtx = (*it)->getLocationContext();
58
72.9k
    SVal LeftV = state->getSVal(LHS, LCtx);
59
72.9k
    SVal RightV = state->getSVal(RHS, LCtx);
60
61
72.9k
    BinaryOperator::Opcode Op = B->getOpcode();
62
63
72.9k
    if (Op == BO_Assign) {
64
      // EXPERIMENTAL: "Conjured" symbols.
65
      // FIXME: Handle structs.
66
20.8k
      if (RightV.isUnknown()) {
67
2.96k
        unsigned Count = currBldrCtx->blockCount();
68
2.96k
        RightV = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx,
69
2.96k
                                              Count);
70
2.96k
      }
71
      // Simulate the effects of a "store":  bind the value of the RHS
72
      // to the L-Value represented by the LHS.
73
20.8k
      SVal ExprVal = B->isGLValue() ? 
LeftV14.8k
:
RightV6.02k
;
74
20.8k
      evalStore(Tmp2, B, LHS, *it, state->BindExpr(B, LCtx, ExprVal),
75
20.8k
                LeftV, RightV);
76
20.8k
      continue;
77
20.8k
    }
78
79
52.0k
    if (!B->isAssignmentOp()) {
80
50.9k
      StmtNodeBuilder Bldr(*it, Tmp2, *currBldrCtx);
81
82
50.9k
      if (B->isAdditiveOp()) {
83
        // TODO: This can be removed after we enable history tracking with
84
        // SymSymExpr.
85
12.7k
        unsigned Count = currBldrCtx->blockCount();
86
12.7k
        RightV = conjureOffsetSymbolOnLocation(
87
12.7k
            RightV, LeftV, RHS, svalBuilder, Count, LCtx);
88
12.7k
        LeftV = conjureOffsetSymbolOnLocation(
89
12.7k
            LeftV, RightV, LHS, svalBuilder, Count, LCtx);
90
12.7k
      }
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
50.9k
      if (B->getOpcode() == BO_PtrMemD)
96
23
        state = createTemporaryRegionIfNeeded(state, LCtx, LHS);
97
98
      // Process non-assignments except commas or short-circuited
99
      // logical expressions (LAnd and LOr).
100
50.9k
      SVal Result = evalBinOp(state, Op, LeftV, RightV, B->getType());
101
50.9k
      if (!Result.isUnknown()) {
102
50.1k
        state = state->BindExpr(B, LCtx, Result);
103
50.1k
      } else {
104
        // If we cannot evaluate the operation escape the operands.
105
830
        state = escapeValues(state, LeftV, PSK_EscapeOther);
106
830
        state = escapeValues(state, RightV, PSK_EscapeOther);
107
830
      }
108
109
50.9k
      Bldr.generateNode(B, *it, state);
110
50.9k
      continue;
111
50.9k
    }
112
113
1.02k
    assert (B->isCompoundAssignmentOp());
114
115
0
    switch (Op) {
116
0
      default:
117
0
        llvm_unreachable("Invalid opcode for compound assignment.");
118
34
      case BO_MulAssign: Op = BO_Mul; break;
119
29
      case BO_DivAssign: Op = BO_Div; break;
120
12
      case BO_RemAssign: Op = BO_Rem; break;
121
471
      case BO_AddAssign: Op = BO_Add; break;
122
196
      case BO_SubAssign: Op = BO_Sub; break;
123
20
      case BO_ShlAssign: Op = BO_Shl; break;
124
8
      case BO_ShrAssign: Op = BO_Shr; break;
125
171
      case BO_AndAssign: Op = BO_And; break;
126
66
      case BO_XorAssign: Op = BO_Xor; break;
127
20
      case BO_OrAssign:  Op = BO_Or;  break;
128
1.02k
    }
129
130
    // Perform a load (the LHS).  This performs the checks for
131
    // null dereferences, and so on.
132
1.02k
    ExplodedNodeSet Tmp;
133
1.02k
    SVal location = LeftV;
134
1.02k
    evalLoad(Tmp, B, LHS, *it, state, location);
135
136
2.05k
    for (ExplodedNodeSet::iterator I = Tmp.begin(), E = Tmp.end(); I != E;
137
1.02k
         
++I1.02k
) {
138
139
1.02k
      state = (*I)->getState();
140
1.02k
      const LocationContext *LCtx = (*I)->getLocationContext();
141
1.02k
      SVal V = state->getSVal(LHS, LCtx);
142
143
      // Get the computation type.
144
1.02k
      QualType CTy =
145
1.02k
        cast<CompoundAssignOperator>(B)->getComputationResultType();
146
1.02k
      CTy = getContext().getCanonicalType(CTy);
147
148
1.02k
      QualType CLHSTy =
149
1.02k
        cast<CompoundAssignOperator>(B)->getComputationLHSType();
150
1.02k
      CLHSTy = getContext().getCanonicalType(CLHSTy);
151
152
1.02k
      QualType LTy = getContext().getCanonicalType(LHS->getType());
153
154
      // Promote LHS.
155
1.02k
      V = svalBuilder.evalCast(V, CLHSTy, LTy);
156
157
      // Compute the result of the operation.
158
1.02k
      SVal Result = svalBuilder.evalCast(evalBinOp(state, Op, V, RightV, CTy),
159
1.02k
                                         B->getType(), CTy);
160
161
      // EXPERIMENTAL: "Conjured" symbols.
162
      // FIXME: Handle structs.
163
164
1.02k
      SVal LHSVal;
165
166
1.02k
      if (Result.isUnknown()) {
167
        // The symbolic value is actually for the type of the left-hand side
168
        // expression, not the computation type, as this is the value the
169
        // LValue on the LHS will bind to.
170
179
        LHSVal = svalBuilder.conjureSymbolVal(nullptr, B->getRHS(), LCtx, LTy,
171
179
                                              currBldrCtx->blockCount());
172
        // However, we need to convert the symbol to the computation type.
173
179
        Result = svalBuilder.evalCast(LHSVal, CTy, LTy);
174
179
      }
175
846
      else {
176
        // The left-hand side may bind to a different value then the
177
        // computation type.
178
846
        LHSVal = svalBuilder.evalCast(Result, LTy, CTy);
179
846
      }
180
181
      // In C++, assignment and compound assignment operators return an
182
      // lvalue.
183
1.02k
      if (B->isGLValue())
184
262
        state = state->BindExpr(B, LCtx, location);
185
763
      else
186
763
        state = state->BindExpr(B, LCtx, Result);
187
188
1.02k
      evalStore(Tmp2, B, LHS, *I, state, location, LHSVal);
189
1.02k
    }
190
1.02k
  }
191
192
  // FIXME: postvisits eventually go in ::Visit()
193
73.1k
  getCheckerManager().runCheckersForPostStmt(Dst, Tmp2, B, *this);
194
73.1k
}
195
196
void ExprEngine::VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
197
384
                                ExplodedNodeSet &Dst) {
198
199
384
  CanQualType T = getContext().getCanonicalType(BE->getType());
200
201
384
  const BlockDecl *BD = BE->getBlockDecl();
202
  // Get the value of the block itself.
203
384
  SVal V = svalBuilder.getBlockPointer(BD, T,
204
384
                                       Pred->getLocationContext(),
205
384
                                       currBldrCtx->blockCount());
206
207
384
  ProgramStateRef State = Pred->getState();
208
209
  // If we created a new MemRegion for the block, we should explicitly bind
210
  // the captured variables.
211
384
  if (const BlockDataRegion *BDR =
212
384
      dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) {
213
214
384
    BlockDataRegion::referenced_vars_iterator I = BDR->referenced_vars_begin(),
215
384
                                              E = BDR->referenced_vars_end();
216
217
384
    auto CI = BD->capture_begin();
218
384
    auto CE = BD->capture_end();
219
701
    for (; I != E; 
++I317
) {
220
317
      const VarRegion *capturedR = I.getCapturedRegion();
221
317
      const TypedValueRegion *originalR = I.getOriginalRegion();
222
223
      // If the capture had a copy expression, use the result of evaluating
224
      // that expression, otherwise use the original value.
225
      // We rely on the invariant that the block declaration's capture variables
226
      // are a prefix of the BlockDataRegion's referenced vars (which may include
227
      // referenced globals, etc.) to enable fast lookup of the capture for a
228
      // given referenced var.
229
317
      const Expr *copyExpr = nullptr;
230
317
      if (CI != CE) {
231
277
        assert(CI->getVariable() == capturedR->getDecl());
232
0
        copyExpr = CI->getCopyExpr();
233
277
        CI++;
234
277
      }
235
236
317
      if (capturedR != originalR) {
237
205
        SVal originalV;
238
205
        const LocationContext *LCtx = Pred->getLocationContext();
239
205
        if (copyExpr) {
240
10
          originalV = State->getSVal(copyExpr, LCtx);
241
195
        } else {
242
195
          originalV = State->getSVal(loc::MemRegionVal(originalR));
243
195
        }
244
205
        State = State->bindLoc(loc::MemRegionVal(capturedR), originalV, LCtx);
245
205
      }
246
317
    }
247
384
  }
248
249
384
  ExplodedNodeSet Tmp;
250
384
  StmtNodeBuilder Bldr(Pred, Tmp, *currBldrCtx);
251
384
  Bldr.generateNode(BE, Pred,
252
384
                    State->BindExpr(BE, Pred->getLocationContext(), V),
253
384
                    nullptr, ProgramPoint::PostLValueKind);
254
255
  // FIXME: Move all post/pre visits to ::Visit().
256
384
  getCheckerManager().runCheckersForPostStmt(Dst, Tmp, BE, *this);
257
384
}
258
259
ProgramStateRef ExprEngine::handleLValueBitCast(
260
    ProgramStateRef state, const Expr* Ex, const LocationContext* LCtx,
261
    QualType T, QualType ExTy, const CastExpr* CastE, StmtNodeBuilder& Bldr,
262
46.8k
    ExplodedNode* Pred) {
263
46.8k
  if (T->isLValueReferenceType()) {
264
6
    assert(!CastE->getType()->isLValueReferenceType());
265
0
    ExTy = getContext().getLValueReferenceType(ExTy);
266
46.7k
  } else if (T->isRValueReferenceType()) {
267
1
    assert(!CastE->getType()->isRValueReferenceType());
268
0
    ExTy = getContext().getRValueReferenceType(ExTy);
269
1
  }
270
  // Delegate to SValBuilder to process.
271
0
  SVal OrigV = state->getSVal(Ex, LCtx);
272
46.8k
  SVal V = svalBuilder.evalCast(OrigV, T, ExTy);
273
  // Negate the result if we're treating the boolean as a signed i1
274
46.8k
  if (CastE->getCastKind() == CK_BooleanToSignedIntegral)
275
0
    V = evalMinus(V);
276
46.8k
  state = state->BindExpr(CastE, LCtx, V);
277
46.8k
  if (V.isUnknown() && 
!OrigV.isUnknown()883
) {
278
242
    state = escapeValues(state, OrigV, PSK_EscapeOther);
279
242
  }
280
46.8k
  Bldr.generateNode(CastE, Pred, state);
281
282
46.8k
  return state;
283
46.8k
}
284
285
ProgramStateRef ExprEngine::handleLVectorSplat(
286
    ProgramStateRef state, const LocationContext* LCtx, const CastExpr* CastE,
287
0
    StmtNodeBuilder &Bldr, ExplodedNode* Pred) {
288
  // Recover some path sensitivity by conjuring a new value.
289
0
  QualType resultType = CastE->getType();
290
0
  if (CastE->isGLValue())
291
0
    resultType = getContext().getPointerType(resultType);
292
0
  SVal result = svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx,
293
0
                                             resultType,
294
0
                                             currBldrCtx->blockCount());
295
0
  state = state->BindExpr(CastE, LCtx, result);
296
0
  Bldr.generateNode(CastE, Pred, state);
297
298
0
  return state;
299
0
}
300
301
void ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex,
302
322k
                           ExplodedNode *Pred, ExplodedNodeSet &Dst) {
303
304
322k
  ExplodedNodeSet dstPreStmt;
305
322k
  getCheckerManager().runCheckersForPreStmt(dstPreStmt, Pred, CastE, *this);
306
307
322k
  if (CastE->getCastKind() == CK_LValueToRValue) {
308
139k
    for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end();
309
279k
         I!=E; 
++I139k
) {
310
139k
      ExplodedNode *subExprNode = *I;
311
139k
      ProgramStateRef state = subExprNode->getState();
312
139k
      const LocationContext *LCtx = subExprNode->getLocationContext();
313
139k
      evalLoad(Dst, CastE, CastE, subExprNode, state, state->getSVal(Ex, LCtx));
314
139k
    }
315
139k
    return;
316
139k
  }
317
318
  // All other casts.
319
182k
  QualType T = CastE->getType();
320
182k
  QualType ExTy = Ex->getType();
321
322
182k
  if (const ExplicitCastExpr *ExCast=dyn_cast_or_null<ExplicitCastExpr>(CastE))
323
18.1k
    T = ExCast->getTypeAsWritten();
324
325
182k
  StmtNodeBuilder Bldr(dstPreStmt, Dst, *currBldrCtx);
326
182k
  for (ExplodedNodeSet::iterator I = dstPreStmt.begin(), E = dstPreStmt.end();
327
365k
       I != E; 
++I182k
) {
328
329
182k
    Pred = *I;
330
182k
    ProgramStateRef state = Pred->getState();
331
182k
    const LocationContext *LCtx = Pred->getLocationContext();
332
333
182k
    switch (CastE->getCastKind()) {
334
0
      case CK_LValueToRValue:
335
0
        llvm_unreachable("LValueToRValue casts handled earlier.");
336
852
      case CK_ToVoid:
337
852
        continue;
338
        // The analyzer doesn't do anything special with these casts,
339
        // since it understands retain/release semantics already.
340
99
      case CK_ARCProduceObject:
341
191
      case CK_ARCConsumeObject:
342
364
      case CK_ARCReclaimReturnedObject:
343
364
      case CK_ARCExtendBlockObject: // Fall-through.
344
368
      case CK_CopyAndAutoreleaseBlockObject:
345
        // The analyser can ignore atomic casts for now, although some future
346
        // checkers may want to make certain that you're not modifying the same
347
        // value through atomic and nonatomic pointers.
348
369
      case CK_AtomicToNonAtomic:
349
370
      case CK_NonAtomicToAtomic:
350
        // True no-ops.
351
34.7k
      case CK_NoOp:
352
36.7k
      case CK_ConstructorConversion:
353
36.9k
      case CK_UserDefinedConversion:
354
96.6k
      case CK_FunctionToPointerDecay:
355
97.7k
      case CK_BuiltinFnToFnPtr: {
356
        // Copy the SVal of Ex to CastE.
357
97.7k
        ProgramStateRef state = Pred->getState();
358
97.7k
        const LocationContext *LCtx = Pred->getLocationContext();
359
97.7k
        SVal V = state->getSVal(Ex, LCtx);
360
97.7k
        state = state->BindExpr(CastE, LCtx, V);
361
97.7k
        Bldr.generateNode(CastE, Pred, state);
362
97.7k
        continue;
363
96.6k
      }
364
20
      case CK_MemberPointerToBoolean:
365
900
      case CK_PointerToBoolean: {
366
900
        SVal V = state->getSVal(Ex, LCtx);
367
900
        auto PTMSV = V.getAs<nonloc::PointerToMember>();
368
900
        if (PTMSV)
369
20
          V = svalBuilder.makeTruthVal(!PTMSV->isNullMemberPointer(), ExTy);
370
900
        if (V.isUndef() || PTMSV) {
371
20
          state = state->BindExpr(CastE, LCtx, V);
372
20
          Bldr.generateNode(CastE, Pred, state);
373
20
          continue;
374
20
        }
375
        // Explicitly proceed with default handler for this case cascade.
376
880
        state =
377
880
            handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
378
880
        continue;
379
900
      }
380
0
      case CK_Dependent:
381
9.36k
      case CK_ArrayToPointerDecay:
382
20.3k
      case CK_BitCast:
383
20.3k
      case CK_LValueToRValueBitCast:
384
20.3k
      case CK_AddressSpaceConversion:
385
20.3k
      case CK_BooleanToSignedIntegral:
386
20.4k
      case CK_IntegralToPointer:
387
20.5k
      case CK_PointerToIntegral: {
388
20.5k
        SVal V = state->getSVal(Ex, LCtx);
389
20.5k
        if (V.getAs<nonloc::PointerToMember>()) {
390
0
          state = state->BindExpr(CastE, LCtx, UnknownVal());
391
0
          Bldr.generateNode(CastE, Pred, state);
392
0
          continue;
393
0
        }
394
        // Explicitly proceed with default handler for this case cascade.
395
20.5k
        state =
396
20.5k
            handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
397
20.5k
        continue;
398
20.5k
      }
399
24.7k
      case CK_IntegralToBoolean:
400
25.0k
      case CK_IntegralToFloating:
401
25.0k
      case CK_FloatingToIntegral:
402
25.1k
      case CK_FloatingToBoolean:
403
25.1k
      case CK_FloatingCast:
404
25.1k
      case CK_FloatingRealToComplex:
405
25.1k
      case CK_FloatingComplexToReal:
406
25.1k
      case CK_FloatingComplexToBoolean:
407
25.1k
      case CK_FloatingComplexCast:
408
25.1k
      case CK_FloatingComplexToIntegralComplex:
409
25.1k
      case CK_IntegralRealToComplex:
410
25.1k
      case CK_IntegralComplexToReal:
411
25.1k
      case CK_IntegralComplexToBoolean:
412
25.1k
      case CK_IntegralComplexCast:
413
25.1k
      case CK_IntegralComplexToFloatingComplex:
414
25.3k
      case CK_CPointerToObjCPointerCast:
415
25.3k
      case CK_BlockPointerToObjCPointerCast:
416
25.3k
      case CK_AnyPointerToBlockPointerCast:
417
25.3k
      case CK_ObjCObjectLValueCast:
418
25.3k
      case CK_ZeroToOCLOpaqueType:
419
25.3k
      case CK_IntToOCLSampler:
420
25.3k
      case CK_LValueBitCast:
421
25.3k
      case CK_FloatingToFixedPoint:
422
25.3k
      case CK_FixedPointToFloating:
423
25.3k
      case CK_FixedPointCast:
424
25.3k
      case CK_FixedPointToBoolean:
425
25.3k
      case CK_FixedPointToIntegral:
426
25.3k
      case CK_IntegralToFixedPoint: {
427
25.3k
        state =
428
25.3k
            handleLValueBitCast(state, Ex, LCtx, T, ExTy, CastE, Bldr, Pred);
429
25.3k
        continue;
430
25.3k
      }
431
32.9k
      case CK_IntegralCast: {
432
        // Delegate to SValBuilder to process.
433
32.9k
        SVal V = state->getSVal(Ex, LCtx);
434
32.9k
        V = svalBuilder.evalIntegralCast(state, V, T, ExTy);
435
32.9k
        state = state->BindExpr(CastE, LCtx, V);
436
32.9k
        Bldr.generateNode(CastE, Pred, state);
437
32.9k
        continue;
438
25.3k
      }
439
224
      case CK_DerivedToBase:
440
834
      case CK_UncheckedDerivedToBase: {
441
        // For DerivedToBase cast, delegate to the store manager.
442
834
        SVal val = state->getSVal(Ex, LCtx);
443
834
        val = getStoreManager().evalDerivedToBase(val, CastE);
444
834
        state = state->BindExpr(CastE, LCtx, val);
445
834
        Bldr.generateNode(CastE, Pred, state);
446
834
        continue;
447
224
      }
448
      // Handle C++ dyn_cast.
449
38
      case CK_Dynamic: {
450
38
        SVal val = state->getSVal(Ex, LCtx);
451
452
        // Compute the type of the result.
453
38
        QualType resultType = CastE->getType();
454
38
        if (CastE->isGLValue())
455
3
          resultType = getContext().getPointerType(resultType);
456
457
38
        bool Failed = false;
458
459
        // Check if the value being cast evaluates to 0.
460
38
        if (val.isZeroConstant())
461
2
          Failed = true;
462
        // Else, evaluate the cast.
463
36
        else
464
36
          val = getStoreManager().attemptDownCast(val, T, Failed);
465
466
38
        if (Failed) {
467
8
          if (T->isReferenceType()) {
468
            // A bad_cast exception is thrown if input value is a reference.
469
            // Currently, we model this, by generating a sink.
470
1
            Bldr.generateSink(CastE, Pred, state);
471
1
            continue;
472
7
          } else {
473
            // If the cast fails on a pointer, bind to 0.
474
7
            state = state->BindExpr(CastE, LCtx, svalBuilder.makeNull());
475
7
          }
476
30
        } else {
477
          // If we don't know if the cast succeeded, conjure a new symbol.
478
30
          if (val.isUnknown()) {
479
0
            DefinedOrUnknownSVal NewSym =
480
0
              svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
481
0
                                           currBldrCtx->blockCount());
482
0
            state = state->BindExpr(CastE, LCtx, NewSym);
483
0
          } else
484
            // Else, bind to the derived region value.
485
30
            state = state->BindExpr(CastE, LCtx, val);
486
30
        }
487
37
        Bldr.generateNode(CastE, Pred, state);
488
37
        continue;
489
38
      }
490
80
      case CK_BaseToDerived: {
491
80
        SVal val = state->getSVal(Ex, LCtx);
492
80
        QualType resultType = CastE->getType();
493
80
        if (CastE->isGLValue())
494
0
          resultType = getContext().getPointerType(resultType);
495
496
80
        bool Failed = false;
497
498
80
        if (!val.isConstant()) {
499
72
          val = getStoreManager().attemptDownCast(val, T, Failed);
500
72
        }
501
502
        // Failed to cast or the result is unknown, fall back to conservative.
503
80
        if (Failed || 
val.isUnknown()76
) {
504
4
          val =
505
4
            svalBuilder.conjureSymbolVal(nullptr, CastE, LCtx, resultType,
506
4
                                         currBldrCtx->blockCount());
507
4
        }
508
80
        state = state->BindExpr(CastE, LCtx, val);
509
80
        Bldr.generateNode(CastE, Pred, state);
510
80
        continue;
511
38
      }
512
3.41k
      case CK_NullToPointer: {
513
3.41k
        SVal V = svalBuilder.makeNull();
514
3.41k
        state = state->BindExpr(CastE, LCtx, V);
515
3.41k
        Bldr.generateNode(CastE, Pred, state);
516
3.41k
        continue;
517
38
      }
518
5
      case CK_NullToMemberPointer: {
519
5
        SVal V = svalBuilder.getMemberPointer(nullptr);
520
5
        state = state->BindExpr(CastE, LCtx, V);
521
5
        Bldr.generateNode(CastE, Pred, state);
522
5
        continue;
523
38
      }
524
5
      case CK_DerivedToBaseMemberPointer:
525
31
      case CK_BaseToDerivedMemberPointer:
526
31
      case CK_ReinterpretMemberPointer: {
527
31
        SVal V = state->getSVal(Ex, LCtx);
528
31
        if (auto PTMSV = V.getAs<nonloc::PointerToMember>()) {
529
31
          SVal CastedPTMSV =
530
31
              svalBuilder.makePointerToMember(getBasicVals().accumCXXBase(
531
31
                  CastE->path(), *PTMSV, CastE->getCastKind()));
532
31
          state = state->BindExpr(CastE, LCtx, CastedPTMSV);
533
31
          Bldr.generateNode(CastE, Pred, state);
534
31
          continue;
535
31
        }
536
        // Explicitly proceed with default handler for this case cascade.
537
0
        state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
538
0
        continue;
539
31
      }
540
      // Various C++ casts that are not handled yet.
541
0
      case CK_ToUnion:
542
0
      case CK_VectorSplat: {
543
0
        state = handleLVectorSplat(state, LCtx, CastE, Bldr, Pred);
544
0
        continue;
545
0
      }
546
0
      case CK_MatrixCast: {
547
        // TODO: Handle MatrixCast here.
548
0
        continue;
549
0
      }
550
182k
    }
551
182k
  }
552
182k
}
553
554
void ExprEngine::VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
555
                                          ExplodedNode *Pred,
556
65
                                          ExplodedNodeSet &Dst) {
557
65
  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
558
559
65
  ProgramStateRef State = Pred->getState();
560
65
  const LocationContext *LCtx = Pred->getLocationContext();
561
562
65
  const Expr *Init = CL->getInitializer();
563
65
  SVal V = State->getSVal(CL->getInitializer(), LCtx);
564
565
65
  if (isa<CXXConstructExpr>(Init) || 
isa<CXXStdInitializerListExpr>(Init)59
) {
566
    // No work needed. Just pass the value up to this expression.
567
55
  } else {
568
55
    assert(isa<InitListExpr>(Init));
569
0
    Loc CLLoc = State->getLValue(CL, LCtx);
570
55
    State = State->bindLoc(CLLoc, V, LCtx);
571
572
55
    if (CL->isGLValue())
573
36
      V = CLLoc;
574
55
  }
575
576
0
  B.generateNode(CL, Pred, State->BindExpr(CL, LCtx, V));
577
65
}
578
579
void ExprEngine::VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
580
31.4k
                               ExplodedNodeSet &Dst) {
581
31.4k
  if (isa<TypedefNameDecl>(*DS->decl_begin())) {
582
    // C99 6.7.7 "Any array size expressions associated with variable length
583
    // array declarators are evaluated each time the declaration of the typedef
584
    // name is reached in the order of execution."
585
    // The checkers should know about typedef to be able to handle VLA size
586
    // expressions.
587
5
    ExplodedNodeSet DstPre;
588
5
    getCheckerManager().runCheckersForPreStmt(DstPre, Pred, DS, *this);
589
5
    getCheckerManager().runCheckersForPostStmt(Dst, DstPre, DS, *this);
590
5
    return;
591
5
  }
592
593
  // Assumption: The CFG has one DeclStmt per Decl.
594
31.4k
  const VarDecl *VD = dyn_cast_or_null<VarDecl>(*DS->decl_begin());
595
596
31.4k
  if (!VD) {
597
    //TODO:AZ: remove explicit insertion after refactoring is done.
598
0
    Dst.insert(Pred);
599
0
    return;
600
0
  }
601
602
  // FIXME: all pre/post visits should eventually be handled by ::Visit().
603
31.4k
  ExplodedNodeSet dstPreVisit;
604
31.4k
  getCheckerManager().runCheckersForPreStmt(dstPreVisit, Pred, DS, *this);
605
606
31.4k
  ExplodedNodeSet dstEvaluated;
607
31.4k
  StmtNodeBuilder B(dstPreVisit, dstEvaluated, *currBldrCtx);
608
31.4k
  for (ExplodedNodeSet::iterator I = dstPreVisit.begin(), E = dstPreVisit.end();
609
62.8k
       I!=E; 
++I31.4k
) {
610
31.4k
    ExplodedNode *N = *I;
611
31.4k
    ProgramStateRef state = N->getState();
612
31.4k
    const LocationContext *LC = N->getLocationContext();
613
614
    // Decls without InitExpr are not initialized explicitly.
615
31.4k
    if (const Expr *InitEx = VD->getInit()) {
616
617
      // Note in the state that the initialization has occurred.
618
28.5k
      ExplodedNode *UpdatedN = N;
619
28.5k
      SVal InitVal = state->getSVal(InitEx, LC);
620
621
28.5k
      assert(DS->isSingleDecl());
622
28.5k
      if (getObjectUnderConstruction(state, DS, LC)) {
623
7.36k
        state = finishObjectConstruction(state, DS, LC);
624
        // We constructed the object directly in the variable.
625
        // No need to bind anything.
626
7.36k
        B.generateNode(DS, UpdatedN, state);
627
21.1k
      } else {
628
        // Recover some path-sensitivity if a scalar value evaluated to
629
        // UnknownVal.
630
21.1k
        if (InitVal.isUnknown()) {
631
5.17k
          QualType Ty = InitEx->getType();
632
5.17k
          if (InitEx->isGLValue()) {
633
0
            Ty = getContext().getPointerType(Ty);
634
0
          }
635
636
5.17k
          InitVal = svalBuilder.conjureSymbolVal(nullptr, InitEx, LC, Ty,
637
5.17k
                                                 currBldrCtx->blockCount());
638
5.17k
        }
639
640
641
21.1k
        B.takeNodes(UpdatedN);
642
21.1k
        ExplodedNodeSet Dst2;
643
21.1k
        evalBind(Dst2, DS, UpdatedN, state->getLValue(VD, LC), InitVal, true);
644
21.1k
        B.addNodes(Dst2);
645
21.1k
      }
646
28.5k
    }
647
2.92k
    else {
648
2.92k
      B.generateNode(DS, N, state);
649
2.92k
    }
650
31.4k
  }
651
652
31.4k
  getCheckerManager().runCheckersForPostStmt(Dst, B.getResults(), DS, *this);
653
31.4k
}
654
655
void ExprEngine::VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
656
1.35k
                                  ExplodedNodeSet &Dst) {
657
  // This method acts upon CFG elements for logical operators && and ||
658
  // and attaches the value (true or false) to them as expressions.
659
  // It doesn't produce any state splits.
660
  // If we made it that far, we're past the point when we modeled the short
661
  // circuit. It means that we should have precise knowledge about whether
662
  // we've short-circuited. If we did, we already know the value we need to
663
  // bind. If we didn't, the value of the RHS (casted to the boolean type)
664
  // is the answer.
665
  // Currently this method tries to figure out whether we've short-circuited
666
  // by looking at the ExplodedGraph. This method is imperfect because there
667
  // could inevitably have been merges that would have resulted in multiple
668
  // potential path traversal histories. We bail out when we fail.
669
  // Due to this ambiguity, a more reliable solution would have been to
670
  // track the short circuit operation history path-sensitively until
671
  // we evaluate the respective logical operator.
672
1.35k
  assert(B->getOpcode() == BO_LAnd ||
673
1.35k
         B->getOpcode() == BO_LOr);
674
675
0
  StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);
676
1.35k
  ProgramStateRef state = Pred->getState();
677
678
1.35k
  if (B->getType()->isVectorType()) {
679
    // FIXME: We do not model vector arithmetic yet. When adding support for
680
    // that, note that the CFG-based reasoning below does not apply, because
681
    // logical operators on vectors are not short-circuit. Currently they are
682
    // modeled as short-circuit in Clang CFG but this is incorrect.
683
    // Do not set the value for the expression. It'd be UnknownVal by default.
684
2
    Bldr.generateNode(B, Pred, state);
685
2
    return;
686
2
  }
687
688
1.35k
  ExplodedNode *N = Pred;
689
2.72k
  while (!N->getLocation().getAs<BlockEntrance>()) {
690
1.37k
    ProgramPoint P = N->getLocation();
691
1.37k
    assert(P.getAs<PreStmt>()|| P.getAs<PreStmtPurgeDeadSymbols>());
692
0
    (void) P;
693
1.37k
    if (N->pred_size() != 1) {
694
      // We failed to track back where we came from.
695
0
      Bldr.generateNode(B, Pred, state);
696
0
      return;
697
0
    }
698
1.37k
    N = *N->pred_begin();
699
1.37k
  }
700
701
1.35k
  if (N->pred_size() != 1) {
702
    // We failed to track back where we came from.
703
6
    Bldr.generateNode(B, Pred, state);
704
6
    return;
705
6
  }
706
707
1.34k
  N = *N->pred_begin();
708
1.34k
  BlockEdge BE = N->getLocation().castAs<BlockEdge>();
709
1.34k
  SVal X;
710
711
  // Determine the value of the expression by introspecting how we
712
  // got this location in the CFG.  This requires looking at the previous
713
  // block we were in and what kind of control-flow transfer was involved.
714
1.34k
  const CFGBlock *SrcBlock = BE.getSrc();
715
  // The only terminator (if there is one) that makes sense is a logical op.
716
1.34k
  CFGTerminator T = SrcBlock->getTerminator();
717
1.34k
  if (const BinaryOperator *Term = cast_or_null<BinaryOperator>(T.getStmt())) {
718
498
    (void) Term;
719
498
    assert(Term->isLogicalOp());
720
0
    assert(SrcBlock->succ_size() == 2);
721
    // Did we take the true or false branch?
722
498
    unsigned constant = (*SrcBlock->succ_begin() == BE.getDst()) ? 
193
:
0405
;
723
498
    X = svalBuilder.makeIntVal(constant, B->getType());
724
498
  }
725
846
  else {
726
    // If there is no terminator, by construction the last statement
727
    // in SrcBlock is the value of the enclosing expression.
728
    // However, we still need to constrain that value to be 0 or 1.
729
846
    assert(!SrcBlock->empty());
730
0
    CFGStmt Elem = SrcBlock->rbegin()->castAs<CFGStmt>();
731
846
    const Expr *RHS = cast<Expr>(Elem.getStmt());
732
846
    SVal RHSVal = N->getState()->getSVal(RHS, Pred->getLocationContext());
733
734
846
    if (RHSVal.isUndef()) {
735
1
      X = RHSVal;
736
845
    } else {
737
      // We evaluate "RHSVal != 0" expression which result in 0 if the value is
738
      // known to be false, 1 if the value is known to be true and a new symbol
739
      // when the assumption is unknown.
740
845
      nonloc::ConcreteInt Zero(getBasicVals().getValue(0, B->getType()));
741
845
      X = evalBinOp(N->getState(), BO_NE,
742
845
                    svalBuilder.evalCast(RHSVal, B->getType(), RHS->getType()),
743
845
                    Zero, B->getType());
744
845
    }
745
846
  }
746
0
  Bldr.generateNode(B, Pred, state->BindExpr(B, Pred->getLocationContext(), X));
747
1.34k
}
748
749
void ExprEngine::VisitInitListExpr(const InitListExpr *IE,
750
                                   ExplodedNode *Pred,
751
1.20k
                                   ExplodedNodeSet &Dst) {
752
1.20k
  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
753
754
1.20k
  ProgramStateRef state = Pred->getState();
755
1.20k
  const LocationContext *LCtx = Pred->getLocationContext();
756
1.20k
  QualType T = getContext().getCanonicalType(IE->getType());
757
1.20k
  unsigned NumInitElements = IE->getNumInits();
758
759
1.20k
  if (!IE->isGLValue() && 
!IE->isTransparent()1.19k
&&
760
1.20k
      
(1.17k
T->isArrayType()1.17k
||
T->isRecordType()642
||
T->isVectorType()68
||
761
1.17k
       
T->isAnyComplexType()62
)) {
762
1.12k
    llvm::ImmutableList<SVal> vals = getBasicVals().getEmptySValList();
763
764
    // Handle base case where the initializer has no elements.
765
    // e.g: static int* myArray[] = {};
766
1.12k
    if (NumInitElements == 0) {
767
168
      SVal V = svalBuilder.makeCompoundVal(T, vals);
768
168
      B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
769
168
      return;
770
168
    }
771
772
953
    for (InitListExpr::const_reverse_iterator it = IE->rbegin(),
773
3.11k
         ei = IE->rend(); it != ei; 
++it2.16k
) {
774
2.16k
      SVal V = state->getSVal(cast<Expr>(*it), LCtx);
775
2.16k
      vals = getBasicVals().prependSVal(V, vals);
776
2.16k
    }
777
778
953
    B.generateNode(IE, Pred,
779
953
                   state->BindExpr(IE, LCtx,
780
953
                                   svalBuilder.makeCompoundVal(T, vals)));
781
953
    return;
782
1.12k
  }
783
784
  // Handle scalars: int{5} and int{} and GLvalues.
785
  // Note, if the InitListExpr is a GLvalue, it means that there is an address
786
  // representing it, so it must have a single init element.
787
86
  assert(NumInitElements <= 1);
788
789
0
  SVal V;
790
86
  if (NumInitElements == 0)
791
57
    V = getSValBuilder().makeZeroVal(T);
792
29
  else
793
29
    V = state->getSVal(IE->getInit(0), LCtx);
794
795
86
  B.generateNode(IE, Pred, state->BindExpr(IE, LCtx, V));
796
86
}
797
798
void ExprEngine::VisitGuardedExpr(const Expr *Ex,
799
                                  const Expr *L,
800
                                  const Expr *R,
801
                                  ExplodedNode *Pred,
802
906
                                  ExplodedNodeSet &Dst) {
803
906
  assert(L && R);
804
805
0
  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
806
906
  ProgramStateRef state = Pred->getState();
807
906
  const LocationContext *LCtx = Pred->getLocationContext();
808
906
  const CFGBlock *SrcBlock = nullptr;
809
810
  // Find the predecessor block.
811
906
  ProgramStateRef SrcState = state;
812
2.72k
  for (const ExplodedNode *N = Pred ; N ; 
N = *N->pred_begin()1.81k
) {
813
2.72k
    ProgramPoint PP = N->getLocation();
814
2.72k
    if (PP.getAs<PreStmtPurgeDeadSymbols>() || 
PP.getAs<BlockEntrance>()1.81k
) {
815
      // If the state N has multiple predecessors P, it means that successors
816
      // of P are all equivalent.
817
      // In turn, that means that all nodes at P are equivalent in terms
818
      // of observable behavior at N, and we can follow any of them.
819
      // FIXME: a more robust solution which does not walk up the tree.
820
1.81k
      continue;
821
1.81k
    }
822
906
    SrcBlock = PP.castAs<BlockEdge>().getSrc();
823
906
    SrcState = N->getState();
824
906
    break;
825
2.72k
  }
826
827
906
  assert(SrcBlock && "missing function entry");
828
829
  // Find the last expression in the predecessor block.  That is the
830
  // expression that is used for the value of the ternary expression.
831
0
  bool hasValue = false;
832
906
  SVal V;
833
834
906
  for (CFGElement CE : llvm::reverse(*SrcBlock)) {
835
906
    if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) {
836
906
      const Expr *ValEx = cast<Expr>(CS->getStmt());
837
906
      ValEx = ValEx->IgnoreParens();
838
839
      // For GNU extension '?:' operator, the left hand side will be an
840
      // OpaqueValueExpr, so get the underlying expression.
841
906
      if (const OpaqueValueExpr *OpaqueEx = dyn_cast<OpaqueValueExpr>(L))
842
21
        L = OpaqueEx->getSourceExpr();
843
844
      // If the last expression in the predecessor block matches true or false
845
      // subexpression, get its the value.
846
906
      if (ValEx == L->IgnoreParens() || 
ValEx == R->IgnoreParens()274
) {
847
904
        hasValue = true;
848
904
        V = SrcState->getSVal(ValEx, LCtx);
849
904
      }
850
906
      break;
851
906
    }
852
906
  }
853
854
906
  if (!hasValue)
855
2
    V = svalBuilder.conjureSymbolVal(nullptr, Ex, LCtx,
856
2
                                     currBldrCtx->blockCount());
857
858
  // Generate a new node with the binding from the appropriate path.
859
906
  B.generateNode(Ex, Pred, state->BindExpr(Ex, LCtx, V, true));
860
906
}
861
862
void ExprEngine::
863
VisitOffsetOfExpr(const OffsetOfExpr *OOE,
864
21
                  ExplodedNode *Pred, ExplodedNodeSet &Dst) {
865
21
  StmtNodeBuilder B(Pred, Dst, *currBldrCtx);
866
21
  Expr::EvalResult Result;
867
21
  if (OOE->EvaluateAsInt(Result, getContext())) {
868
21
    APSInt IV = Result.Val.getInt();
869
21
    assert(IV.getBitWidth() == getContext().getTypeSize(OOE->getType()));
870
0
    assert(OOE->getType()->castAs<BuiltinType>()->isInteger());
871
0
    assert(IV.isSigned() == OOE->getType()->isSignedIntegerType());
872
0
    SVal X = svalBuilder.makeIntVal(IV);
873
21
    B.generateNode(OOE, Pred,
874
21
                   Pred->getState()->BindExpr(OOE, Pred->getLocationContext(),
875
21
                                              X));
876
21
  }
877
  // FIXME: Handle the case where __builtin_offsetof is not a constant.
878
21
}
879
880
881
void ExprEngine::
882
VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
883
                              ExplodedNode *Pred,
884
963
                              ExplodedNodeSet &Dst) {
885
  // FIXME: Prechecks eventually go in ::Visit().
886
963
  ExplodedNodeSet CheckedSet;
887
963
  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, Ex, *this);
888
889
963
  ExplodedNodeSet EvalSet;
890
963
  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
891
892
963
  QualType T = Ex->getTypeOfArgument();
893
894
963
  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
895
1.92k
       I != E; 
++I961
) {
896
961
    if (Ex->getKind() == UETT_SizeOf) {
897
958
      if (!T->isIncompleteType() && 
!T->isConstantSizeType()954
) {
898
11
        assert(T->isVariableArrayType() && "Unknown non-constant-sized type.");
899
900
        // FIXME: Add support for VLA type arguments and VLA expressions.
901
        // When that happens, we should probably refactor VLASizeChecker's code.
902
0
        continue;
903
947
      } else if (T->getAs<ObjCObjectType>()) {
904
        // Some code tries to take the sizeof an ObjCObjectType, relying that
905
        // the compiler has laid out its representation.  Just report Unknown
906
        // for these.
907
0
        continue;
908
0
      }
909
958
    }
910
911
950
    APSInt Value = Ex->EvaluateKnownConstInt(getContext());
912
950
    CharUnits amt = CharUnits::fromQuantity(Value.getZExtValue());
913
914
950
    ProgramStateRef state = (*I)->getState();
915
950
    state = state->BindExpr(Ex, (*I)->getLocationContext(),
916
950
                            svalBuilder.makeIntVal(amt.getQuantity(),
917
950
                                                   Ex->getType()));
918
950
    Bldr.generateNode(Ex, *I, state);
919
950
  }
920
921
963
  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, Ex, *this);
922
963
}
923
924
void ExprEngine::handleUOExtension(ExplodedNodeSet::iterator I,
925
                                   const UnaryOperator *U,
926
17.0k
                                   StmtNodeBuilder &Bldr) {
927
  // FIXME: We can probably just have some magic in Environment::getSVal()
928
  // that propagates values, instead of creating a new node here.
929
  //
930
  // Unary "+" is a no-op, similar to a parentheses.  We still have places
931
  // where it may be a block-level expression, so we need to
932
  // generate an extra node that just propagates the value of the
933
  // subexpression.
934
17.0k
  const Expr *Ex = U->getSubExpr()->IgnoreParens();
935
17.0k
  ProgramStateRef state = (*I)->getState();
936
17.0k
  const LocationContext *LCtx = (*I)->getLocationContext();
937
17.0k
  Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
938
17.0k
                                           state->getSVal(Ex, LCtx)));
939
17.0k
}
940
941
void ExprEngine::VisitUnaryOperator(const UnaryOperator* U, ExplodedNode *Pred,
942
28.4k
                                    ExplodedNodeSet &Dst) {
943
  // FIXME: Prechecks eventually go in ::Visit().
944
28.4k
  ExplodedNodeSet CheckedSet;
945
28.4k
  getCheckerManager().runCheckersForPreStmt(CheckedSet, Pred, U, *this);
946
947
28.4k
  ExplodedNodeSet EvalSet;
948
28.4k
  StmtNodeBuilder Bldr(CheckedSet, EvalSet, *currBldrCtx);
949
950
28.4k
  for (ExplodedNodeSet::iterator I = CheckedSet.begin(), E = CheckedSet.end();
951
56.8k
       I != E; 
++I28.4k
) {
952
28.4k
    switch (U->getOpcode()) {
953
7.82k
    default: {
954
7.82k
      Bldr.takeNodes(*I);
955
7.82k
      ExplodedNodeSet Tmp;
956
7.82k
      VisitIncrementDecrementOperator(U, *I, Tmp);
957
7.82k
      Bldr.addNodes(Tmp);
958
7.82k
      break;
959
0
    }
960
14
    case UO_Real: {
961
14
      const Expr *Ex = U->getSubExpr()->IgnoreParens();
962
963
      // FIXME: We don't have complex SValues yet.
964
14
      if (Ex->getType()->isAnyComplexType()) {
965
        // Just report "Unknown."
966
10
        break;
967
10
      }
968
969
      // For all other types, UO_Real is an identity operation.
970
4
      assert (U->getType() == Ex->getType());
971
0
      ProgramStateRef state = (*I)->getState();
972
4
      const LocationContext *LCtx = (*I)->getLocationContext();
973
4
      Bldr.generateNode(U, *I, state->BindExpr(U, LCtx,
974
4
                                               state->getSVal(Ex, LCtx)));
975
4
      break;
976
14
    }
977
978
11
    case UO_Imag: {
979
11
      const Expr *Ex = U->getSubExpr()->IgnoreParens();
980
      // FIXME: We don't have complex SValues yet.
981
11
      if (Ex->getType()->isAnyComplexType()) {
982
        // Just report "Unknown."
983
8
        break;
984
8
      }
985
      // For all other types, UO_Imag returns 0.
986
3
      ProgramStateRef state = (*I)->getState();
987
3
      const LocationContext *LCtx = (*I)->getLocationContext();
988
3
      SVal X = svalBuilder.makeZeroVal(Ex->getType());
989
3
      Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, X));
990
3
      break;
991
11
    }
992
993
3.67k
    case UO_AddrOf: {
994
      // Process pointer-to-member address operation.
995
3.67k
      const Expr *Ex = U->getSubExpr()->IgnoreParens();
996
3.67k
      if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex)) {
997
2.91k
        const ValueDecl *VD = DRE->getDecl();
998
999
2.91k
        if (isa<CXXMethodDecl>(VD) || 
isa<FieldDecl>(VD)2.89k
||
1000
2.91k
            
isa<IndirectFieldDecl>(VD)2.87k
) {
1001
59
          ProgramStateRef State = (*I)->getState();
1002
59
          const LocationContext *LCtx = (*I)->getLocationContext();
1003
59
          SVal SV = svalBuilder.getMemberPointer(cast<NamedDecl>(VD));
1004
59
          Bldr.generateNode(U, *I, State->BindExpr(U, LCtx, SV));
1005
59
          break;
1006
59
        }
1007
2.91k
      }
1008
      // Explicitly proceed with default handler for this case cascade.
1009
3.61k
      handleUOExtension(I, U, Bldr);
1010
3.61k
      break;
1011
3.67k
    }
1012
4
    case UO_Plus:
1013
4
      assert(!U->isGLValue());
1014
4
      LLVM_FALLTHROUGH;
1015
13.4k
    case UO_Deref:
1016
13.4k
    case UO_Extension: {
1017
13.4k
      handleUOExtension(I, U, Bldr);
1018
13.4k
      break;
1019
13.4k
    }
1020
1021
1.11k
    case UO_LNot:
1022
2.43k
    case UO_Minus:
1023
3.43k
    case UO_Not: {
1024
3.43k
      assert (!U->isGLValue());
1025
0
      const Expr *Ex = U->getSubExpr()->IgnoreParens();
1026
3.43k
      ProgramStateRef state = (*I)->getState();
1027
3.43k
      const LocationContext *LCtx = (*I)->getLocationContext();
1028
1029
      // Get the value of the subexpression.
1030
3.43k
      SVal V = state->getSVal(Ex, LCtx);
1031
1032
3.43k
      if (V.isUnknownOrUndef()) {
1033
10
        Bldr.generateNode(U, *I, state->BindExpr(U, LCtx, V));
1034
10
        break;
1035
10
      }
1036
1037
3.42k
      switch (U->getOpcode()) {
1038
0
        default:
1039
0
          llvm_unreachable("Invalid Opcode.");
1040
1.00k
        case UO_Not:
1041
          // FIXME: Do we need to handle promotions?
1042
1.00k
          state = state->BindExpr(U, LCtx, evalComplement(V.castAs<NonLoc>()));
1043
1.00k
          break;
1044
1.31k
        case UO_Minus:
1045
          // FIXME: Do we need to handle promotions?
1046
1.31k
          state = state->BindExpr(U, LCtx, evalMinus(V.castAs<NonLoc>()));
1047
1.31k
          break;
1048
1.11k
        case UO_LNot:
1049
          // C99 6.5.3.3: "The expression !E is equivalent to (0==E)."
1050
          //
1051
          //  Note: technically we do "E == 0", but this is the same in the
1052
          //    transfer functions as "0 == E".
1053
1.11k
          SVal Result;
1054
1.11k
          if (Optional<Loc> LV = V.getAs<Loc>()) {
1055
281
            Loc X = svalBuilder.makeNullWithType(Ex->getType());
1056
281
            Result = evalBinOp(state, BO_EQ, *LV, X, U->getType());
1057
831
          } else if (Ex->getType()->isFloatingType()) {
1058
            // FIXME: handle floating point types.
1059
1
            Result = UnknownVal();
1060
830
          } else {
1061
830
            nonloc::ConcreteInt X(getBasicVals().getValue(0, Ex->getType()));
1062
830
            Result = evalBinOp(state, BO_EQ, V.castAs<NonLoc>(), X,
1063
830
                               U->getType());
1064
830
          }
1065
1066
1.11k
          state = state->BindExpr(U, LCtx, Result);
1067
1.11k
          break;
1068
3.42k
      }
1069
3.42k
      Bldr.generateNode(U, *I, state);
1070
3.42k
      break;
1071
3.42k
    }
1072
28.4k
    }
1073
28.4k
  }
1074
1075
28.4k
  getCheckerManager().runCheckersForPostStmt(Dst, EvalSet, U, *this);
1076
28.4k
}
1077
1078
void ExprEngine::VisitIncrementDecrementOperator(const UnaryOperator* U,
1079
                                                 ExplodedNode *Pred,
1080
7.82k
                                                 ExplodedNodeSet &Dst) {
1081
  // Handle ++ and -- (both pre- and post-increment).
1082
7.82k
  assert (U->isIncrementDecrementOp());
1083
0
  const Expr *Ex = U->getSubExpr()->IgnoreParens();
1084
1085
7.82k
  const LocationContext *LCtx = Pred->getLocationContext();
1086
7.82k
  ProgramStateRef state = Pred->getState();
1087
7.82k
  SVal loc = state->getSVal(Ex, LCtx);
1088
1089
  // Perform a load.
1090
7.82k
  ExplodedNodeSet Tmp;
1091
7.82k
  evalLoad(Tmp, U, Ex, Pred, state, loc);
1092
1093
7.82k
  ExplodedNodeSet Dst2;
1094
7.82k
  StmtNodeBuilder Bldr(Tmp, Dst2, *currBldrCtx);
1095
15.6k
  for (ExplodedNodeSet::iterator I=Tmp.begin(), E=Tmp.end();I!=E;
++I7.81k
) {
1096
1097
7.81k
    state = (*I)->getState();
1098
7.81k
    assert(LCtx == (*I)->getLocationContext());
1099
0
    SVal V2_untested = state->getSVal(Ex, LCtx);
1100
1101
    // Propagate unknown and undefined values.
1102
7.81k
    if (V2_untested.isUnknownOrUndef()) {
1103
292
      state = state->BindExpr(U, LCtx, V2_untested);
1104
1105
      // Perform the store, so that the uninitialized value detection happens.
1106
292
      Bldr.takeNodes(*I);
1107
292
      ExplodedNodeSet Dst3;
1108
292
      evalStore(Dst3, U, Ex, *I, state, loc, V2_untested);
1109
292
      Bldr.addNodes(Dst3);
1110
1111
292
      continue;
1112
292
    }
1113
7.52k
    DefinedSVal V2 = V2_untested.castAs<DefinedSVal>();
1114
1115
    // Handle all other values.
1116
7.52k
    BinaryOperator::Opcode Op = U->isIncrementOp() ? 
BO_Add7.12k
:
BO_Sub398
;
1117
1118
    // If the UnaryOperator has non-location type, use its type to create the
1119
    // constant value. If the UnaryOperator has location type, create the
1120
    // constant with int type and pointer width.
1121
7.52k
    SVal RHS;
1122
7.52k
    SVal Result;
1123
1124
7.52k
    if (U->getType()->isAnyPointerType())
1125
833
      RHS = svalBuilder.makeArrayIndex(1);
1126
6.69k
    else if (U->getType()->isIntegralOrEnumerationType())
1127
6.69k
      RHS = svalBuilder.makeIntVal(1, U->getType());
1128
1
    else
1129
1
      RHS = UnknownVal();
1130
1131
    // The use of an operand of type bool with the ++ operators is deprecated
1132
    // but valid until C++17. And if the operand of the ++ operator is of type
1133
    // bool, it is set to true until C++17. Note that for '_Bool', it is also
1134
    // set to true when it encounters ++ operator.
1135
7.52k
    if (U->getType()->isBooleanType() && 
U->isIncrementOp()70
)
1136
52
      Result = svalBuilder.makeTruthVal(true, U->getType());
1137
7.47k
    else
1138
7.47k
      Result = evalBinOp(state, Op, V2, RHS, U->getType());
1139
1140
    // Conjure a new symbol if necessary to recover precision.
1141
7.52k
    if (Result.isUnknown()){
1142
3
      DefinedOrUnknownSVal SymVal =
1143
3
        svalBuilder.conjureSymbolVal(nullptr, U, LCtx,
1144
3
                                     currBldrCtx->blockCount());
1145
3
      Result = SymVal;
1146
1147
      // If the value is a location, ++/-- should always preserve
1148
      // non-nullness.  Check if the original value was non-null, and if so
1149
      // propagate that constraint.
1150
3
      if (Loc::isLocType(U->getType())) {
1151
0
        DefinedOrUnknownSVal Constraint =
1152
0
        svalBuilder.evalEQ(state, V2,svalBuilder.makeZeroVal(U->getType()));
1153
1154
0
        if (!state->assume(Constraint, true)) {
1155
          // It isn't feasible for the original value to be null.
1156
          // Propagate this constraint.
1157
0
          Constraint = svalBuilder.evalEQ(state, SymVal,
1158
0
                                       svalBuilder.makeZeroVal(U->getType()));
1159
1160
0
          state = state->assume(Constraint, false);
1161
0
          assert(state);
1162
0
        }
1163
0
      }
1164
3
    }
1165
1166
    // Since the lvalue-to-rvalue conversion is explicit in the AST,
1167
    // we bind an l-value if the operator is prefix and an lvalue (in C++).
1168
7.52k
    if (U->isGLValue())
1169
1.32k
      state = state->BindExpr(U, LCtx, loc);
1170
6.20k
    else
1171
6.20k
      state = state->BindExpr(U, LCtx, U->isPostfix() ? 
V25.67k
:
Result530
);
1172
1173
    // Perform the store.
1174
7.52k
    Bldr.takeNodes(*I);
1175
7.52k
    ExplodedNodeSet Dst3;
1176
7.52k
    evalStore(Dst3, U, Ex, *I, state, loc, Result);
1177
7.52k
    Bldr.addNodes(Dst3);
1178
7.52k
  }
1179
7.82k
  Dst.insert(Dst2);
1180
7.82k
}