Coverage Report

Created: 2020-02-15 09:57

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/Analysis/ThreadSafety.cpp
Line
Count
Source (jump to first uncovered line)
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//===- ThreadSafety.cpp ---------------------------------------------------===//
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
// A intra-procedural analysis for thread safety (e.g. deadlocks and race
10
// conditions), based off of an annotation system.
11
//
12
// See http://clang.llvm.org/docs/ThreadSafetyAnalysis.html
13
// for more information.
14
//
15
//===----------------------------------------------------------------------===//
16
17
#include "clang/Analysis/Analyses/ThreadSafety.h"
18
#include "clang/AST/Attr.h"
19
#include "clang/AST/Decl.h"
20
#include "clang/AST/DeclCXX.h"
21
#include "clang/AST/DeclGroup.h"
22
#include "clang/AST/Expr.h"
23
#include "clang/AST/ExprCXX.h"
24
#include "clang/AST/OperationKinds.h"
25
#include "clang/AST/Stmt.h"
26
#include "clang/AST/StmtVisitor.h"
27
#include "clang/AST/Type.h"
28
#include "clang/Analysis/Analyses/PostOrderCFGView.h"
29
#include "clang/Analysis/Analyses/ThreadSafetyCommon.h"
30
#include "clang/Analysis/Analyses/ThreadSafetyTIL.h"
31
#include "clang/Analysis/Analyses/ThreadSafetyTraverse.h"
32
#include "clang/Analysis/Analyses/ThreadSafetyUtil.h"
33
#include "clang/Analysis/AnalysisDeclContext.h"
34
#include "clang/Analysis/CFG.h"
35
#include "clang/Basic/Builtins.h"
36
#include "clang/Basic/LLVM.h"
37
#include "clang/Basic/OperatorKinds.h"
38
#include "clang/Basic/SourceLocation.h"
39
#include "clang/Basic/Specifiers.h"
40
#include "llvm/ADT/ArrayRef.h"
41
#include "llvm/ADT/DenseMap.h"
42
#include "llvm/ADT/ImmutableMap.h"
43
#include "llvm/ADT/Optional.h"
44
#include "llvm/ADT/PointerIntPair.h"
45
#include "llvm/ADT/STLExtras.h"
46
#include "llvm/ADT/SmallVector.h"
47
#include "llvm/ADT/StringRef.h"
48
#include "llvm/Support/Allocator.h"
49
#include "llvm/Support/Casting.h"
50
#include "llvm/Support/ErrorHandling.h"
51
#include "llvm/Support/raw_ostream.h"
52
#include <algorithm>
53
#include <cassert>
54
#include <functional>
55
#include <iterator>
56
#include <memory>
57
#include <string>
58
#include <type_traits>
59
#include <utility>
60
#include <vector>
61
62
using namespace clang;
63
using namespace threadSafety;
64
65
// Key method definition
66
2.14k
ThreadSafetyHandler::~ThreadSafetyHandler() = default;
67
68
/// Issue a warning about an invalid lock expression
69
static void warnInvalidLock(ThreadSafetyHandler &Handler,
70
                            const Expr *MutexExp, const NamedDecl *D,
71
0
                            const Expr *DeclExp, StringRef Kind) {
72
0
  SourceLocation Loc;
73
0
  if (DeclExp)
74
0
    Loc = DeclExp->getExprLoc();
75
0
76
0
  // FIXME: add a note about the attribute location in MutexExp or D
77
0
  if (Loc.isValid())
78
0
    Handler.handleInvalidLockExp(Kind, Loc);
79
0
}
80
81
namespace {
82
83
/// A set of CapabilityExpr objects, which are compiled from thread safety
84
/// attributes on a function.
85
class CapExprSet : public SmallVector<CapabilityExpr, 4> {
86
public:
87
  /// Push M onto list, but discard duplicates.
88
4.84k
  void push_back_nodup(const CapabilityExpr &CapE) {
89
4.84k
    iterator It = std::find_if(begin(), end(),
90
4.84k
                               [=](const CapabilityExpr &CapE2) {
91
1.09k
      return CapE.equals(CapE2);
92
1.09k
    });
93
4.84k
    if (It == end())
94
4.42k
      push_back(CapE);
95
4.84k
  }
96
};
97
98
class FactManager;
99
class FactSet;
100
101
/// This is a helper class that stores a fact that is known at a
102
/// particular point in program execution.  Currently, a fact is a capability,
103
/// along with additional information, such as where it was acquired, whether
104
/// it is exclusive or shared, etc.
105
///
106
/// FIXME: this analysis does not currently support re-entrant locking.
107
class FactEntry : public CapabilityExpr {
108
private:
109
  /// Exclusive or shared.
110
  LockKind LKind;
111
112
  /// Where it was acquired.
113
  SourceLocation AcquireLoc;
114
115
  /// True if the lock was asserted.
116
  bool Asserted;
117
118
  /// True if the lock was declared.
119
  bool Declared;
120
121
public:
122
  FactEntry(const CapabilityExpr &CE, LockKind LK, SourceLocation Loc,
123
            bool Asrt, bool Declrd = false)
124
      : CapabilityExpr(CE), LKind(LK), AcquireLoc(Loc), Asserted(Asrt),
125
4.45k
        Declared(Declrd) {}
126
4.45k
  virtual ~FactEntry() = default;
127
128
2.21k
  LockKind kind() const { return LKind;      }
129
3.05k
  SourceLocation loc() const { return AcquireLoc; }
130
5.44k
  bool asserted() const { return Asserted; }
131
2.47k
  bool declared() const { return Declared; }
132
133
503
  void setDeclared(bool D) { Declared = D; }
134
135
  virtual void
136
  handleRemovalFromIntersection(const FactSet &FSet, FactManager &FactMan,
137
                                SourceLocation JoinLoc, LockErrorKind LEK,
138
                                ThreadSafetyHandler &Handler) const = 0;
139
  virtual void handleLock(FactSet &FSet, FactManager &FactMan,
140
                          const FactEntry &entry, ThreadSafetyHandler &Handler,
141
                          StringRef DiagKind) const = 0;
142
  virtual void handleUnlock(FactSet &FSet, FactManager &FactMan,
143
                            const CapabilityExpr &Cp, SourceLocation UnlockLoc,
144
                            bool FullyRemove, ThreadSafetyHandler &Handler,
145
                            StringRef DiagKind) const = 0;
146
147
  // Return true if LKind >= LK, where exclusive > shared
148
1.74k
  bool isAtLeast(LockKind LK) const {
149
1.74k
    return  (LKind == LK_Exclusive) || 
(LK == LK_Shared)303
;
150
1.74k
  }
151
};
152
153
using FactID = unsigned short;
154
155
/// FactManager manages the memory for all facts that are created during
156
/// the analysis of a single routine.
157
class FactManager {
158
private:
159
  std::vector<std::unique_ptr<const FactEntry>> Facts;
160
161
public:
162
4.31k
  FactID newFact(std::unique_ptr<FactEntry> Entry) {
163
4.31k
    Facts.push_back(std::move(Entry));
164
4.31k
    return static_cast<unsigned short>(Facts.size() - 1);
165
4.31k
  }
166
167
25.7k
  const FactEntry &operator[](FactID F) const { return *Facts[F]; }
168
};
169
170
/// A FactSet is the set of facts that are known to be true at a
171
/// particular program point.  FactSets must be small, because they are
172
/// frequently copied, and are thus implemented as a set of indices into a
173
/// table maintained by a FactManager.  A typical FactSet only holds 1 or 2
174
/// locks, so we can get away with doing a linear search for lookup.  Note
175
/// that a hashtable or map is inappropriate in this case, because lookups
176
/// may involve partial pattern matches, rather than exact matches.
177
class FactSet {
178
private:
179
  using FactVec = SmallVector<FactID, 4>;
180
181
  FactVec FactIDs;
182
183
public:
184
  using iterator = FactVec::iterator;
185
  using const_iterator = FactVec::const_iterator;
186
187
4.95k
  iterator begin() { return FactIDs.begin(); }
188
15.5k
  const_iterator begin() const { return FactIDs.begin(); }
189
190
7.27k
  iterator end() { return FactIDs.end(); }
191
28.5k
  const_iterator end() const { return FactIDs.end(); }
192
193
0
  bool isEmpty() const { return FactIDs.size() == 0; }
194
195
  // Return true if the set contains only negative facts
196
58
  bool isEmpty(FactManager &FactMan) const {
197
58
    for (const auto FID : *this) {
198
34
      if (!FactMan[FID].negative())
199
24
        return false;
200
34
    }
201
58
    
return true34
;
202
58
  }
203
204
0
  void addLockByID(FactID ID) { FactIDs.push_back(ID); }
205
206
4.31k
  FactID addLock(FactManager &FM, std::unique_ptr<FactEntry> Entry) {
207
4.31k
    FactID F = FM.newFact(std::move(Entry));
208
4.31k
    FactIDs.push_back(F);
209
4.31k
    return F;
210
4.31k
  }
211
212
2.43k
  bool removeLock(FactManager& FM, const CapabilityExpr &CapE) {
213
2.43k
    unsigned n = FactIDs.size();
214
2.43k
    if (n == 0)
215
0
      return false;
216
2.43k
217
3.13k
    
for (unsigned i = 0; 2.43k
i < n-1;
++i706
) {
218
1.52k
      if (FM[FactIDs[i]].matches(CapE)) {
219
822
        FactIDs[i] = FactIDs[n-1];
220
822
        FactIDs.pop_back();
221
822
        return true;
222
822
      }
223
1.52k
    }
224
2.43k
    
if (1.61k
FM[FactIDs[n-1]].matches(CapE)1.61k
) {
225
1.60k
      FactIDs.pop_back();
226
1.60k
      return true;
227
1.60k
    }
228
4
    return false;
229
4
  }
230
231
2.32k
  iterator findLockIter(FactManager &FM, const CapabilityExpr &CapE) {
232
2.32k
    return std::find_if(begin(), end(), [&](FactID ID) {
233
1.61k
      return FM[ID].matches(CapE);
234
1.61k
    });
235
2.32k
  }
236
237
8.39k
  const FactEntry *findLock(FactManager &FM, const CapabilityExpr &CapE) const {
238
8.39k
    auto I = std::find_if(begin(), end(), [&](FactID ID) {
239
7.63k
      return FM[ID].matches(CapE);
240
7.63k
    });
241
8.39k
    return I != end() ? 
&FM[*I]3.47k
:
nullptr4.91k
;
242
8.39k
  }
243
244
  const FactEntry *findLockUniv(FactManager &FM,
245
2.88k
                                const CapabilityExpr &CapE) const {
246
2.88k
    auto I = std::find_if(begin(), end(), [&](FactID ID) -> bool {
247
2.79k
      return FM[ID].matchesUniv(CapE);
248
2.79k
    });
249
2.88k
    return I != end() ? 
&FM[*I]1.74k
:
nullptr1.14k
;
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2.88k
  }
251
252
  const FactEntry *findPartialMatch(FactManager &FM,
253
1.14k
                                    const CapabilityExpr &CapE) const {
254
1.14k
    auto I = std::find_if(begin(), end(), [&](FactID ID) -> bool {
255
510
      return FM[ID].partiallyMatches(CapE);
256
510
    });
257
1.14k
    return I != end() ? 
&FM[*I]76
:
nullptr1.06k
;
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1.14k
  }
259
260
490
  bool containsMutexDecl(FactManager &FM, const ValueDecl* Vd) const {
261
490
    auto I = std::find_if(begin(), end(), [&](FactID ID) -> bool {
262
193
      return FM[ID].valueDecl() == Vd;
263
193
    });
264
490
    return I != end();
265
490
  }
266
};
267
268
class ThreadSafetyAnalyzer;
269
270
} // namespace
271
272
namespace clang {
273
namespace threadSafety {
274
275
class BeforeSet {
276
private:
277
  using BeforeVect = SmallVector<const ValueDecl *, 4>;
278
279
  struct BeforeInfo {
280
    BeforeVect Vect;
281
    int Visited = 0;
282
283
747
    BeforeInfo() = default;
284
    BeforeInfo(BeforeInfo &&) = default;
285
  };
286
287
  using BeforeMap =
288
      llvm::DenseMap<const ValueDecl *, std::unique_ptr<BeforeInfo>>;
289
  using CycleMap = llvm::DenseMap<const ValueDecl *, bool>;
290
291
public:
292
34
  BeforeSet() = default;
293
294
  BeforeInfo* insertAttrExprs(const ValueDecl* Vd,
295
                              ThreadSafetyAnalyzer& Analyzer);
296
297
  BeforeInfo *getBeforeInfoForDecl(const ValueDecl *Vd,
298
                                   ThreadSafetyAnalyzer &Analyzer);
299
300
  void checkBeforeAfter(const ValueDecl* Vd,
301
                        const FactSet& FSet,
302
                        ThreadSafetyAnalyzer& Analyzer,
303
                        SourceLocation Loc, StringRef CapKind);
304
305
private:
306
  BeforeMap BMap;
307
  CycleMap CycMap;
308
};
309
310
} // namespace threadSafety
311
} // namespace clang
312
313
namespace {
314
315
class LocalVariableMap;
316
317
using LocalVarContext = llvm::ImmutableMap<const NamedDecl *, unsigned>;
318
319
/// A side (entry or exit) of a CFG node.
320
enum CFGBlockSide { CBS_Entry, CBS_Exit };
321
322
/// CFGBlockInfo is a struct which contains all the information that is
323
/// maintained for each block in the CFG.  See LocalVariableMap for more
324
/// information about the contexts.
325
struct CFGBlockInfo {
326
  // Lockset held at entry to block
327
  FactSet EntrySet;
328
329
  // Lockset held at exit from block
330
  FactSet ExitSet;
331
332
  // Context held at entry to block
333
  LocalVarContext EntryContext;
334
335
  // Context held at exit from block
336
  LocalVarContext ExitContext;
337
338
  // Location of first statement in block
339
  SourceLocation EntryLoc;
340
341
  // Location of last statement in block.
342
  SourceLocation ExitLoc;
343
344
  // Used to replay contexts later
345
  unsigned EntryIndex;
346
347
  // Is this block reachable?
348
  bool Reachable = false;
349
350
0
  const FactSet &getSet(CFGBlockSide Side) const {
351
0
    return Side == CBS_Entry ? EntrySet : ExitSet;
352
0
  }
353
354
0
  SourceLocation getLocation(CFGBlockSide Side) const {
355
0
    return Side == CBS_Entry ? EntryLoc : ExitLoc;
356
0
  }
357
358
private:
359
  CFGBlockInfo(LocalVarContext EmptyCtx)
360
2.02k
      : EntryContext(EmptyCtx), ExitContext(EmptyCtx) {}
361
362
public:
363
  static CFGBlockInfo getEmptyBlockInfo(LocalVariableMap &M);
364
};
365
366
// A LocalVariableMap maintains a map from local variables to their currently
367
// valid definitions.  It provides SSA-like functionality when traversing the
368
// CFG.  Like SSA, each definition or assignment to a variable is assigned a
369
// unique name (an integer), which acts as the SSA name for that definition.
370
// The total set of names is shared among all CFG basic blocks.
371
// Unlike SSA, we do not rewrite expressions to replace local variables declrefs
372
// with their SSA-names.  Instead, we compute a Context for each point in the
373
// code, which maps local variables to the appropriate SSA-name.  This map
374
// changes with each assignment.
375
//
376
// The map is computed in a single pass over the CFG.  Subsequent analyses can
377
// then query the map to find the appropriate Context for a statement, and use
378
// that Context to look up the definitions of variables.
379
class LocalVariableMap {
380
public:
381
  using Context = LocalVarContext;
382
383
  /// A VarDefinition consists of an expression, representing the value of the
384
  /// variable, along with the context in which that expression should be
385
  /// interpreted.  A reference VarDefinition does not itself contain this
386
  /// information, but instead contains a pointer to a previous VarDefinition.
387
  struct VarDefinition {
388
  public:
389
    friend class LocalVariableMap;
390
391
    // The original declaration for this variable.
392
    const NamedDecl *Dec;
393
394
    // The expression for this variable, OR
395
    const Expr *Exp = nullptr;
396
397
    // Reference to another VarDefinition
398
    unsigned Ref = 0;
399
400
    // The map with which Exp should be interpreted.
401
    Context Ctx;
402
403
32
    bool isReference() { return !Exp; }
404
405
  private:
406
    // Create ordinary variable definition
407
    VarDefinition(const NamedDecl *D, const Expr *E, Context C)
408
696
        : Dec(D), Exp(E), Ctx(C) {}
409
410
    // Create reference to previous definition
411
    VarDefinition(const NamedDecl *D, unsigned R, Context C)
412
2.17k
        : Dec(D), Ref(R), Ctx(C) {}
413
  };
414
415
private:
416
  Context::Factory ContextFactory;
417
  std::vector<VarDefinition> VarDefinitions;
418
  std::vector<unsigned> CtxIndices;
419
  std::vector<std::pair<const Stmt *, Context>> SavedContexts;
420
421
public:
422
2.14k
  LocalVariableMap() {
423
2.14k
    // index 0 is a placeholder for undefined variables (aka phi-nodes).
424
2.14k
    VarDefinitions.push_back(VarDefinition(nullptr, 0u, getEmptyContext()));
425
2.14k
  }
426
427
  /// Look up a definition, within the given context.
428
0
  const VarDefinition* lookup(const NamedDecl *D, Context Ctx) {
429
0
    const unsigned *i = Ctx.lookup(D);
430
0
    if (!i)
431
0
      return nullptr;
432
0
    assert(*i < VarDefinitions.size());
433
0
    return &VarDefinitions[*i];
434
0
  }
435
436
  /// Look up the definition for D within the given context.  Returns
437
  /// NULL if the expression is not statically known.  If successful, also
438
  /// modifies Ctx to hold the context of the return Expr.
439
168
  const Expr* lookupExpr(const NamedDecl *D, Context &Ctx) {
440
168
    const unsigned *P = Ctx.lookup(D);
441
168
    if (!P)
442
40
      return nullptr;
443
128
444
128
    unsigned i = *P;
445
152
    while (i > 0) {
446
136
      if (VarDefinitions[i].Exp) {
447
112
        Ctx = VarDefinitions[i].Ctx;
448
112
        return VarDefinitions[i].Exp;
449
112
      }
450
24
      i = VarDefinitions[i].Ref;
451
24
    }
452
128
    
return nullptr16
;
453
128
  }
454
455
4.27k
  Context getEmptyContext() { return ContextFactory.getEmptyMap(); }
456
457
  /// Return the next context after processing S.  This function is used by
458
  /// clients of the class to get the appropriate context when traversing the
459
  /// CFG.  It must be called for every assignment or DeclStmt.
460
2.36k
  Context getNextContext(unsigned &CtxIndex, const Stmt *S, Context C) {
461
2.36k
    if (SavedContexts[CtxIndex+1].first == S) {
462
710
      CtxIndex++;
463
710
      Context Result = SavedContexts[CtxIndex].second;
464
710
      return Result;
465
710
    }
466
1.65k
    return C;
467
1.65k
  }
468
469
0
  void dumpVarDefinitionName(unsigned i) {
470
0
    if (i == 0) {
471
0
      llvm::errs() << "Undefined";
472
0
      return;
473
0
    }
474
0
    const NamedDecl *Dec = VarDefinitions[i].Dec;
475
0
    if (!Dec) {
476
0
      llvm::errs() << "<<NULL>>";
477
0
      return;
478
0
    }
479
0
    Dec->printName(llvm::errs());
480
0
    llvm::errs() << "." << i << " " << ((const void*) Dec);
481
0
  }
482
483
  /// Dumps an ASCII representation of the variable map to llvm::errs()
484
0
  void dump() {
485
0
    for (unsigned i = 1, e = VarDefinitions.size(); i < e; ++i) {
486
0
      const Expr *Exp = VarDefinitions[i].Exp;
487
0
      unsigned Ref = VarDefinitions[i].Ref;
488
0
489
0
      dumpVarDefinitionName(i);
490
0
      llvm::errs() << " = ";
491
0
      if (Exp) Exp->dump();
492
0
      else {
493
0
        dumpVarDefinitionName(Ref);
494
0
        llvm::errs() << "\n";
495
0
      }
496
0
    }
497
0
  }
498
499
  /// Dumps an ASCII representation of a Context to llvm::errs()
500
0
  void dumpContext(Context C) {
501
0
    for (Context::iterator I = C.begin(), E = C.end(); I != E; ++I) {
502
0
      const NamedDecl *D = I.getKey();
503
0
      D->printName(llvm::errs());
504
0
      const unsigned *i = C.lookup(D);
505
0
      llvm::errs() << " -> ";
506
0
      dumpVarDefinitionName(*i);
507
0
      llvm::errs() << "\n";
508
0
    }
509
0
  }
510
511
  /// Builds the variable map.
512
  void traverseCFG(CFG *CFGraph, const PostOrderCFGView *SortedGraph,
513
                   std::vector<CFGBlockInfo> &BlockInfo);
514
515
protected:
516
  friend class VarMapBuilder;
517
518
  // Get the current context index
519
7.42k
  unsigned getContextIndex() { return SavedContexts.size()-1; }
520
521
  // Save the current context for later replay
522
10.1k
  void saveContext(const Stmt *S, Context C) {
523
10.1k
    SavedContexts.push_back(std::make_pair(S, C));
524
10.1k
  }
525
526
  // Adds a new definition to the given context, and returns a new context.
527
  // This method should be called when declaring a new variable.
528
568
  Context addDefinition(const NamedDecl *D, const Expr *Exp, Context Ctx) {
529
568
    assert(!Ctx.contains(D));
530
568
    unsigned newID = VarDefinitions.size();
531
568
    Context NewCtx = ContextFactory.add(Ctx, D, newID);
532
568
    VarDefinitions.push_back(VarDefinition(D, Exp, Ctx));
533
568
    return NewCtx;
534
568
  }
535
536
  // Add a new reference to an existing definition.
537
32
  Context addReference(const NamedDecl *D, unsigned i, Context Ctx) {
538
32
    unsigned newID = VarDefinitions.size();
539
32
    Context NewCtx = ContextFactory.add(Ctx, D, newID);
540
32
    VarDefinitions.push_back(VarDefinition(D, i, Ctx));
541
32
    return NewCtx;
542
32
  }
543
544
  // Updates a definition only if that definition is already in the map.
545
  // This method should be called when assigning to an existing variable.
546
128
  Context updateDefinition(const NamedDecl *D, Expr *Exp, Context Ctx) {
547
128
    if (Ctx.contains(D)) {
548
128
      unsigned newID = VarDefinitions.size();
549
128
      Context NewCtx = ContextFactory.remove(Ctx, D);
550
128
      NewCtx = ContextFactory.add(NewCtx, D, newID);
551
128
      VarDefinitions.push_back(VarDefinition(D, Exp, Ctx));
552
128
      return NewCtx;
553
128
    }
554
0
    return Ctx;
555
0
  }
556
557
  // Removes a definition from the context, but keeps the variable name
558
  // as a valid variable.  The index 0 is a placeholder for cleared definitions.
559
22
  Context clearDefinition(const NamedDecl *D, Context Ctx) {
560
22
    Context NewCtx = Ctx;
561
22
    if (NewCtx.contains(D)) {
562
22
      NewCtx = ContextFactory.remove(NewCtx, D);
563
22
      NewCtx = ContextFactory.add(NewCtx, D, 0);
564
22
    }
565
22
    return NewCtx;
566
22
  }
567
568
  // Remove a definition entirely frmo the context.
569
12
  Context removeDefinition(const NamedDecl *D, Context Ctx) {
570
12
    Context NewCtx = Ctx;
571
12
    if (NewCtx.contains(D)) {
572
12
      NewCtx = ContextFactory.remove(NewCtx, D);
573
12
    }
574
12
    return NewCtx;
575
12
  }
576
577
  Context intersectContexts(Context C1, Context C2);
578
  Context createReferenceContext(Context C);
579
  void intersectBackEdge(Context C1, Context C2);
580
};
581
582
} // namespace
583
584
// This has to be defined after LocalVariableMap.
585
2.02k
CFGBlockInfo CFGBlockInfo::getEmptyBlockInfo(LocalVariableMap &M) {
586
2.02k
  return CFGBlockInfo(M.getEmptyContext());
587
2.02k
}
588
589
namespace {
590
591
/// Visitor which builds a LocalVariableMap
592
class VarMapBuilder : public ConstStmtVisitor<VarMapBuilder> {
593
public:
594
  LocalVariableMap* VMap;
595
  LocalVariableMap::Context Ctx;
596
597
  VarMapBuilder(LocalVariableMap *VM, LocalVariableMap::Context C)
598
7.42k
      : VMap(VM), Ctx(C) {}
599
600
  void VisitDeclStmt(const DeclStmt *S);
601
  void VisitBinaryOperator(const BinaryOperator *BO);
602
};
603
604
} // namespace
605
606
// Add new local variables to the variable map
607
892
void VarMapBuilder::VisitDeclStmt(const DeclStmt *S) {
608
892
  bool modifiedCtx = false;
609
892
  const DeclGroupRef DGrp = S->getDeclGroup();
610
892
  for (const auto *D : DGrp) {
611
892
    if (const auto *VD = dyn_cast_or_null<VarDecl>(D)) {
612
892
      const Expr *E = VD->getInit();
613
892
614
892
      // Add local variables with trivial type to the variable map
615
892
      QualType T = VD->getType();
616
892
      if (T.isTrivialType(VD->getASTContext())) {
617
568
        Ctx = VMap->addDefinition(VD, E, Ctx);
618
568
        modifiedCtx = true;
619
568
      }
620
892
    }
621
892
  }
622
892
  if (modifiedCtx)
623
568
    VMap->saveContext(S, Ctx);
624
892
}
625
626
// Update local variable definitions in variable map
627
1.84k
void VarMapBuilder::VisitBinaryOperator(const BinaryOperator *BO) {
628
1.84k
  if (!BO->isAssignmentOp())
629
377
    return;
630
1.47k
631
1.47k
  Expr *LHSExp = BO->getLHS()->IgnoreParenCasts();
632
1.47k
633
1.47k
  // Update the variable map and current context.
634
1.47k
  if (const auto *DRE = dyn_cast<DeclRefExpr>(LHSExp)) {
635
302
    const ValueDecl *VDec = DRE->getDecl();
636
302
    if (Ctx.lookup(VDec)) {
637
142
      if (BO->getOpcode() == BO_Assign)
638
128
        Ctx = VMap->updateDefinition(VDec, BO->getRHS(), Ctx);
639
14
      else
640
14
        // FIXME -- handle compound assignment operators
641
14
        Ctx = VMap->clearDefinition(VDec, Ctx);
642
142
      VMap->saveContext(BO, Ctx);
643
142
    }
644
302
  }
645
1.47k
}
646
647
// Computes the intersection of two contexts.  The intersection is the
648
// set of variables which have the same definition in both contexts;
649
// variables with different definitions are discarded.
650
LocalVariableMap::Context
651
589
LocalVariableMap::intersectContexts(Context C1, Context C2) {
652
589
  Context Result = C1;
653
589
  for (const auto &P : C1) {
654
268
    const NamedDecl *Dec = P.first;
655
268
    const unsigned *i2 = C2.lookup(Dec);
656
268
    if (!i2)             // variable doesn't exist on second path
657
12
      Result = removeDefinition(Dec, Result);
658
256
    else if (*i2 != P.second)  // variable exists, but has different definition
659
8
      Result = clearDefinition(Dec, Result);
660
268
  }
661
589
  return Result;
662
589
}
663
664
// For every variable in C, create a new variable that refers to the
665
// definition in C.  Return a new context that contains these new variables.
666
// (We use this for a naive implementation of SSA on loop back-edges.)
667
106
LocalVariableMap::Context LocalVariableMap::createReferenceContext(Context C) {
668
106
  Context Result = getEmptyContext();
669
106
  for (const auto &P : C)
670
32
    Result = addReference(P.first, P.second, Result);
671
106
  return Result;
672
106
}
673
674
// This routine also takes the intersection of C1 and C2, but it does so by
675
// altering the VarDefinitions.  C1 must be the result of an earlier call to
676
// createReferenceContext.
677
98
void LocalVariableMap::intersectBackEdge(Context C1, Context C2) {
678
98
  for (const auto &P : C1) {
679
32
    unsigned i1 = P.second;
680
32
    VarDefinition *VDef = &VarDefinitions[i1];
681
32
    assert(VDef->isReference());
682
32
683
32
    const unsigned *i2 = C2.lookup(P.first);
684
32
    if (!i2 || (*i2 != i1))
685
12
      VDef->Ref = 0;    // Mark this variable as undefined
686
32
  }
687
98
}
688
689
// Traverse the CFG in topological order, so all predecessors of a block
690
// (excluding back-edges) are visited before the block itself.  At
691
// each point in the code, we calculate a Context, which holds the set of
692
// variable definitions which are visible at that point in execution.
693
// Visible variables are mapped to their definitions using an array that
694
// contains all definitions.
695
//
696
// At join points in the CFG, the set is computed as the intersection of
697
// the incoming sets along each edge, E.g.
698
//
699
//                       { Context                 | VarDefinitions }
700
//   int x = 0;          { x -> x1                 | x1 = 0 }
701
//   int y = 0;          { x -> x1, y -> y1        | y1 = 0, x1 = 0 }
702
//   if (b) x = 1;       { x -> x2, y -> y1        | x2 = 1, y1 = 0, ... }
703
//   else   x = 2;       { x -> x3, y -> y1        | x3 = 2, x2 = 1, ... }
704
//   ...                 { y -> y1  (x is unknown) | x3 = 2, x2 = 1, ... }
705
//
706
// This is essentially a simpler and more naive version of the standard SSA
707
// algorithm.  Those definitions that remain in the intersection are from blocks
708
// that strictly dominate the current block.  We do not bother to insert proper
709
// phi nodes, because they are not used in our analysis; instead, wherever
710
// a phi node would be required, we simply remove that definition from the
711
// context (E.g. x above).
712
//
713
// The initial traversal does not capture back-edges, so those need to be
714
// handled on a separate pass.  Whenever the first pass encounters an
715
// incoming back edge, it duplicates the context, creating new definitions
716
// that refer back to the originals.  (These correspond to places where SSA
717
// might have to insert a phi node.)  On the second pass, these definitions are
718
// set to NULL if the variable has changed on the back-edge (i.e. a phi
719
// node was actually required.)  E.g.
720
//
721
//                       { Context           | VarDefinitions }
722
//   int x = 0, y = 0;   { x -> x1, y -> y1  | y1 = 0, x1 = 0 }
723
//   while (b)           { x -> x2, y -> y1  | [1st:] x2=x1; [2nd:] x2=NULL; }
724
//     x = x+1;          { x -> x3, y -> y1  | x3 = x2 + 1, ... }
725
//   ...                 { y -> y1           | x3 = 2, x2 = 1, ... }
726
void LocalVariableMap::traverseCFG(CFG *CFGraph,
727
                                   const PostOrderCFGView *SortedGraph,
728
2.02k
                                   std::vector<CFGBlockInfo> &BlockInfo) {
729
2.02k
  PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph);
730
2.02k
731
2.02k
  CtxIndices.resize(CFGraph->getNumBlockIDs());
732
2.02k
733
7.42k
  for (const auto *CurrBlock : *SortedGraph) {
734
7.42k
    unsigned CurrBlockID = CurrBlock->getBlockID();
735
7.42k
    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID];
736
7.42k
737
7.42k
    VisitedBlocks.insert(CurrBlock);
738
7.42k
739
7.42k
    // Calculate the entry context for the current block
740
7.42k
    bool HasBackEdges = false;
741
7.42k
    bool CtxInit = true;
742
7.42k
    for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
743
13.5k
         PE  = CurrBlock->pred_end(); PI != PE; 
++PI6.09k
) {
744
6.09k
      // if *PI -> CurrBlock is a back edge, so skip it
745
6.09k
      if (*PI == nullptr || !VisitedBlocks.alreadySet(*PI)) {
746
106
        HasBackEdges = true;
747
106
        continue;
748
106
      }
749
5.98k
750
5.98k
      unsigned PrevBlockID = (*PI)->getBlockID();
751
5.98k
      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
752
5.98k
753
5.98k
      if (CtxInit) {
754
5.39k
        CurrBlockInfo->EntryContext = PrevBlockInfo->ExitContext;
755
5.39k
        CtxInit = false;
756
5.39k
      }
757
589
      else {
758
589
        CurrBlockInfo->EntryContext =
759
589
          intersectContexts(CurrBlockInfo->EntryContext,
760
589
                            PrevBlockInfo->ExitContext);
761
589
      }
762
5.98k
    }
763
7.42k
764
7.42k
    // Duplicate the context if we have back-edges, so we can call
765
7.42k
    // intersectBackEdges later.
766
7.42k
    if (HasBackEdges)
767
106
      CurrBlockInfo->EntryContext =
768
106
        createReferenceContext(CurrBlockInfo->EntryContext);
769
7.42k
770
7.42k
    // Create a starting context index for the current block
771
7.42k
    saveContext(nullptr, CurrBlockInfo->EntryContext);
772
7.42k
    CurrBlockInfo->EntryIndex = getContextIndex();
773
7.42k
774
7.42k
    // Visit all the statements in the basic block.
775
7.42k
    VarMapBuilder VMapBuilder(this, CurrBlockInfo->EntryContext);
776
33.9k
    for (const auto &BI : *CurrBlock) {
777
33.9k
      switch (BI.getKind()) {
778
33.6k
        case CFGElement::Statement: {
779
33.6k
          CFGStmt CS = BI.castAs<CFGStmt>();
780
33.6k
          VMapBuilder.Visit(CS.getStmt());
781
33.6k
          break;
782
0
        }
783
282
        default:
784
282
          break;
785
33.9k
      }
786
33.9k
    }
787
7.42k
    CurrBlockInfo->ExitContext = VMapBuilder.Ctx;
788
7.42k
789
7.42k
    // Mark variables on back edges as "unknown" if they've been changed.
790
7.42k
    for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
791
13.5k
         SE  = CurrBlock->succ_end(); SI != SE; 
++SI6.08k
) {
792
6.08k
      // if CurrBlock -> *SI is *not* a back edge
793
6.08k
      if (*SI == nullptr || 
!VisitedBlocks.alreadySet(*SI)6.08k
)
794
5.98k
        continue;
795
98
796
98
      CFGBlock *FirstLoopBlock = *SI;
797
98
      Context LoopBegin = BlockInfo[FirstLoopBlock->getBlockID()].EntryContext;
798
98
      Context LoopEnd   = CurrBlockInfo->ExitContext;
799
98
      intersectBackEdge(LoopBegin, LoopEnd);
800
98
    }
801
7.42k
  }
802
2.02k
803
2.02k
  // Put an extra entry at the end of the indexed context array
804
2.02k
  unsigned exitID = CFGraph->getExit().getBlockID();
805
2.02k
  saveContext(nullptr, BlockInfo[exitID].ExitContext);
806
2.02k
}
807
808
/// Find the appropriate source locations to use when producing diagnostics for
809
/// each block in the CFG.
810
static void findBlockLocations(CFG *CFGraph,
811
                               const PostOrderCFGView *SortedGraph,
812
2.02k
                               std::vector<CFGBlockInfo> &BlockInfo) {
813
7.42k
  for (const auto *CurrBlock : *SortedGraph) {
814
7.42k
    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlock->getBlockID()];
815
7.42k
816
7.42k
    // Find the source location of the last statement in the block, if the
817
7.42k
    // block is not empty.
818
7.42k
    if (const Stmt *S = CurrBlock->getTerminatorStmt()) {
819
713
      CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc = S->getBeginLoc();
820
6.70k
    } else {
821
6.70k
      for (CFGBlock::const_reverse_iterator BI = CurrBlock->rbegin(),
822
6.96k
           BE = CurrBlock->rend(); BI != BE; 
++BI256
) {
823
2.81k
        // FIXME: Handle other CFGElement kinds.
824
2.81k
        if (Optional<CFGStmt> CS = BI->getAs<CFGStmt>()) {
825
2.55k
          CurrBlockInfo->ExitLoc = CS->getStmt()->getBeginLoc();
826
2.55k
          break;
827
2.55k
        }
828
2.81k
      }
829
6.70k
    }
830
7.42k
831
7.42k
    if (CurrBlockInfo->ExitLoc.isValid()) {
832
3.27k
      // This block contains at least one statement. Find the source location
833
3.27k
      // of the first statement in the block.
834
3.27k
      for (const auto &BI : *CurrBlock) {
835
3.24k
        // FIXME: Handle other CFGElement kinds.
836
3.24k
        if (Optional<CFGStmt> CS = BI.getAs<CFGStmt>()) {
837
3.24k
          CurrBlockInfo->EntryLoc = CS->getStmt()->getBeginLoc();
838
3.24k
          break;
839
3.24k
        }
840
3.24k
      }
841
4.15k
    } else if (CurrBlock->pred_size() == 1 && 
*CurrBlock->pred_begin()1.91k
&&
842
4.15k
               
CurrBlock != &CFGraph->getExit()1.91k
) {
843
78
      // The block is empty, and has a single predecessor. Use its exit
844
78
      // location.
845
78
      CurrBlockInfo->EntryLoc = CurrBlockInfo->ExitLoc =
846
78
          BlockInfo[(*CurrBlock->pred_begin())->getBlockID()].ExitLoc;
847
78
    }
848
7.42k
  }
849
2.02k
}
850
851
namespace {
852
853
class LockableFactEntry : public FactEntry {
854
private:
855
  /// managed by ScopedLockable object
856
  bool Managed;
857
858
public:
859
  LockableFactEntry(const CapabilityExpr &CE, LockKind LK, SourceLocation Loc,
860
                    bool Mng = false, bool Asrt = false)
861
4.23k
      : FactEntry(CE, LK, Loc, Asrt), Managed(Mng) {}
862
863
  void
864
  handleRemovalFromIntersection(const FactSet &FSet, FactManager &FactMan,
865
                                SourceLocation JoinLoc, LockErrorKind LEK,
866
1.56k
                                ThreadSafetyHandler &Handler) const override {
867
1.56k
    if (!Managed && 
!asserted()1.54k
&&
!negative()1.50k
&&
!isUniversal()169
) {
868
165
      Handler.handleMutexHeldEndOfScope("mutex", toString(), loc(), JoinLoc,
869
165
                                        LEK);
870
165
    }
871
1.56k
  }
872
873
  void handleLock(FactSet &FSet, FactManager &FactMan, const FactEntry &entry,
874
                  ThreadSafetyHandler &Handler,
875
67
                  StringRef DiagKind) const override {
876
67
    Handler.handleDoubleLock(DiagKind, entry.toString(), loc(), entry.loc());
877
67
  }
878
879
  void handleUnlock(FactSet &FSet, FactManager &FactMan,
880
                    const CapabilityExpr &Cp, SourceLocation UnlockLoc,
881
                    bool FullyRemove, ThreadSafetyHandler &Handler,
882
1.45k
                    StringRef DiagKind) const override {
883
1.45k
    FSet.removeLock(FactMan, Cp);
884
1.45k
    if (!Cp.negative()) {
885
1.45k
      FSet.addLock(FactMan, std::make_unique<LockableFactEntry>(
886
1.45k
                                !Cp, LK_Exclusive, UnlockLoc));
887
1.45k
    }
888
1.45k
  }
889
};
890
891
class ScopedLockableFactEntry : public FactEntry {
892
private:
893
  enum UnderlyingCapabilityKind {
894
    UCK_Acquired,          ///< Any kind of acquired capability.
895
    UCK_ReleasedShared,    ///< Shared capability that was released.
896
    UCK_ReleasedExclusive, ///< Exclusive capability that was released.
897
  };
898
899
  using UnderlyingCapability =
900
      llvm::PointerIntPair<const til::SExpr *, 2, UnderlyingCapabilityKind>;
901
902
  SmallVector<UnderlyingCapability, 4> UnderlyingMutexes;
903
904
public:
905
  ScopedLockableFactEntry(const CapabilityExpr &CE, SourceLocation Loc)
906
222
      : FactEntry(CE, LK_Exclusive, Loc, false) {}
907
908
162
  void addExclusiveLock(const CapabilityExpr &M) {
909
162
    UnderlyingMutexes.emplace_back(M.sexpr(), UCK_Acquired);
910
162
  }
911
912
28
  void addSharedLock(const CapabilityExpr &M) {
913
28
    UnderlyingMutexes.emplace_back(M.sexpr(), UCK_Acquired);
914
28
  }
915
916
28
  void addExclusiveUnlock(const CapabilityExpr &M) {
917
28
    UnderlyingMutexes.emplace_back(M.sexpr(), UCK_ReleasedExclusive);
918
28
  }
919
920
8
  void addSharedUnlock(const CapabilityExpr &M) {
921
8
    UnderlyingMutexes.emplace_back(M.sexpr(), UCK_ReleasedShared);
922
8
  }
923
924
  void
925
  handleRemovalFromIntersection(const FactSet &FSet, FactManager &FactMan,
926
                                SourceLocation JoinLoc, LockErrorKind LEK,
927
28
                                ThreadSafetyHandler &Handler) const override {
928
28
    for (const auto &UnderlyingMutex : UnderlyingMutexes) {
929
28
      const auto *Entry = FSet.findLock(
930
28
          FactMan, CapabilityExpr(UnderlyingMutex.getPointer(), false));
931
28
      if ((UnderlyingMutex.getInt() == UCK_Acquired && Entry) ||
932
28
          
(16
UnderlyingMutex.getInt() != UCK_Acquired16
&&
!Entry0
)) {
933
12
        // If this scoped lock manages another mutex, and if the underlying
934
12
        // mutex is still/not held, then warn about the underlying mutex.
935
12
        Handler.handleMutexHeldEndOfScope(
936
12
            "mutex", sx::toString(UnderlyingMutex.getPointer()), loc(), JoinLoc,
937
12
            LEK);
938
12
      }
939
28
    }
940
28
  }
941
942
  void handleLock(FactSet &FSet, FactManager &FactMan, const FactEntry &entry,
943
                  ThreadSafetyHandler &Handler,
944
48
                  StringRef DiagKind) const override {
945
48
    for (const auto &UnderlyingMutex : UnderlyingMutexes) {
946
48
      CapabilityExpr UnderCp(UnderlyingMutex.getPointer(), false);
947
48
948
48
      if (UnderlyingMutex.getInt() == UCK_Acquired)
949
40
        lock(FSet, FactMan, UnderCp, entry.kind(), entry.loc(), &Handler,
950
40
             DiagKind);
951
8
      else
952
8
        unlock(FSet, FactMan, UnderCp, entry.loc(), &Handler, DiagKind);
953
48
    }
954
48
  }
955
956
  void handleUnlock(FactSet &FSet, FactManager &FactMan,
957
                    const CapabilityExpr &Cp, SourceLocation UnlockLoc,
958
                    bool FullyRemove, ThreadSafetyHandler &Handler,
959
298
                    StringRef DiagKind) const override {
960
298
    assert(!Cp.negative() && "Managing object cannot be negative.");
961
302
    for (const auto &UnderlyingMutex : UnderlyingMutexes) {
962
302
      CapabilityExpr UnderCp(UnderlyingMutex.getPointer(), false);
963
302
964
302
      // Remove/lock the underlying mutex if it exists/is still unlocked; warn
965
302
      // on double unlocking/locking if we're not destroying the scoped object.
966
302
      ThreadSafetyHandler *TSHandler = FullyRemove ? 
nullptr198
:
&Handler104
;
967
302
      if (UnderlyingMutex.getInt() == UCK_Acquired) {
968
246
        unlock(FSet, FactMan, UnderCp, UnlockLoc, TSHandler, DiagKind);
969
246
      } else {
970
56
        LockKind kind = UnderlyingMutex.getInt() == UCK_ReleasedShared
971
56
                            ? 
LK_Shared8
972
56
                            : 
LK_Exclusive48
;
973
56
        lock(FSet, FactMan, UnderCp, kind, UnlockLoc, TSHandler, DiagKind);
974
56
      }
975
302
    }
976
298
    if (FullyRemove)
977
194
      FSet.removeLock(FactMan, Cp);
978
298
  }
979
980
private:
981
  void lock(FactSet &FSet, FactManager &FactMan, const CapabilityExpr &Cp,
982
            LockKind kind, SourceLocation loc, ThreadSafetyHandler *Handler,
983
96
            StringRef DiagKind) const {
984
96
    if (const FactEntry *Fact = FSet.findLock(FactMan, Cp)) {
985
20
      if (Handler)
986
12
        Handler->handleDoubleLock(DiagKind, Cp.toString(), Fact->loc(), loc);
987
76
    } else {
988
76
      FSet.removeLock(FactMan, !Cp);
989
76
      FSet.addLock(FactMan,
990
76
                   std::make_unique<LockableFactEntry>(Cp, kind, loc));
991
76
    }
992
96
  }
993
994
  void unlock(FactSet &FSet, FactManager &FactMan, const CapabilityExpr &Cp,
995
              SourceLocation loc, ThreadSafetyHandler *Handler,
996
254
              StringRef DiagKind) const {
997
254
    if (FSet.findLock(FactMan, Cp)) {
998
206
      FSet.removeLock(FactMan, Cp);
999
206
      FSet.addLock(FactMan, std::make_unique<LockableFactEntry>(
1000
206
                                !Cp, LK_Exclusive, loc));
1001
206
    } else 
if (48
Handler48
) {
1002
16
      Handler->handleUnmatchedUnlock(DiagKind, Cp.toString(), loc);
1003
16
    }
1004
254
  }
1005
};
1006
1007
/// Class which implements the core thread safety analysis routines.
1008
class ThreadSafetyAnalyzer {
1009
  friend class BuildLockset;
1010
  friend class threadSafety::BeforeSet;
1011
1012
  llvm::BumpPtrAllocator Bpa;
1013
  threadSafety::til::MemRegionRef Arena;
1014
  threadSafety::SExprBuilder SxBuilder;
1015
1016
  ThreadSafetyHandler &Handler;
1017
  const CXXMethodDecl *CurrentMethod;
1018
  LocalVariableMap LocalVarMap;
1019
  FactManager FactMan;
1020
  std::vector<CFGBlockInfo> BlockInfo;
1021
1022
  BeforeSet *GlobalBeforeSet;
1023
1024
public:
1025
  ThreadSafetyAnalyzer(ThreadSafetyHandler &H, BeforeSet* Bset)
1026
2.14k
      : Arena(&Bpa), SxBuilder(Arena), Handler(H), GlobalBeforeSet(Bset) {}
1027
1028
  bool inCurrentScope(const CapabilityExpr &CapE);
1029
1030
  void addLock(FactSet &FSet, std::unique_ptr<FactEntry> Entry,
1031
               StringRef DiagKind, bool ReqAttr = false);
1032
  void removeLock(FactSet &FSet, const CapabilityExpr &CapE,
1033
                  SourceLocation UnlockLoc, bool FullyRemove, LockKind Kind,
1034
                  StringRef DiagKind);
1035
1036
  template <typename AttrType>
1037
  void getMutexIDs(CapExprSet &Mtxs, AttrType *Attr, const Expr *Exp,
1038
                   const NamedDecl *D, VarDecl *SelfDecl = nullptr);
1039
1040
  template <class AttrType>
1041
  void getMutexIDs(CapExprSet &Mtxs, AttrType *Attr, const Expr *Exp,
1042
                   const NamedDecl *D,
1043
                   const CFGBlock *PredBlock, const CFGBlock *CurrBlock,
1044
                   Expr *BrE, bool Neg);
1045
1046
  const CallExpr* getTrylockCallExpr(const Stmt *Cond, LocalVarContext C,
1047
                                     bool &Negate);
1048
1049
  void getEdgeLockset(FactSet &Result, const FactSet &ExitSet,
1050
                      const CFGBlock* PredBlock,
1051
                      const CFGBlock *CurrBlock);
1052
1053
  void intersectAndWarn(FactSet &FSet1, const FactSet &FSet2,
1054
                        SourceLocation JoinLoc,
1055
                        LockErrorKind LEK1, LockErrorKind LEK2,
1056
                        bool Modify=true);
1057
1058
  void intersectAndWarn(FactSet &FSet1, const FactSet &FSet2,
1059
                        SourceLocation JoinLoc, LockErrorKind LEK1,
1060
667
                        bool Modify=true) {
1061
667
    intersectAndWarn(FSet1, FSet2, JoinLoc, LEK1, LEK1, Modify);
1062
667
  }
1063
1064
  void runAnalysis(AnalysisDeclContext &AC);
1065
};
1066
1067
} // namespace
1068
1069
/// Process acquired_before and acquired_after attributes on Vd.
1070
BeforeSet::BeforeInfo* BeforeSet::insertAttrExprs(const ValueDecl* Vd,
1071
747
    ThreadSafetyAnalyzer& Analyzer) {
1072
747
  // Create a new entry for Vd.
1073
747
  BeforeInfo *Info = nullptr;
1074
747
  {
1075
747
    // Keep InfoPtr in its own scope in case BMap is modified later and the
1076
747
    // reference becomes invalid.
1077
747
    std::unique_ptr<BeforeInfo> &InfoPtr = BMap[Vd];
1078
747
    if (!InfoPtr)
1079
747
      InfoPtr.reset(new BeforeInfo());
1080
747
    Info = InfoPtr.get();
1081
747
  }
1082
747
1083
747
  for (const auto *At : Vd->attrs()) {
1084
137
    switch (At->getKind()) {
1085
52
      case attr::AcquiredBefore: {
1086
52
        const auto *A = cast<AcquiredBeforeAttr>(At);
1087
52
1088
52
        // Read exprs from the attribute, and add them to BeforeVect.
1089
64
        for (const auto *Arg : A->args()) {
1090
64
          CapabilityExpr Cp =
1091
64
            Analyzer.SxBuilder.translateAttrExpr(Arg, nullptr);
1092
64
          if (const ValueDecl *Cpvd = Cp.valueDecl()) {
1093
60
            Info->Vect.push_back(Cpvd);
1094
60
            const auto It = BMap.find(Cpvd);
1095
60
            if (It == BMap.end())
1096
40
              insertAttrExprs(Cpvd, Analyzer);
1097
60
          }
1098
64
        }
1099
52
        break;
1100
0
      }
1101
85
      case attr::AcquiredAfter: {
1102
85
        const auto *A = cast<AcquiredAfterAttr>(At);
1103
85
1104
85
        // Read exprs from the attribute, and add them to BeforeVect.
1105
93
        for (const auto *Arg : A->args()) {
1106
93
          CapabilityExpr Cp =
1107
93
            Analyzer.SxBuilder.translateAttrExpr(Arg, nullptr);
1108
93
          if (const ValueDecl *ArgVd = Cp.valueDecl()) {
1109
93
            // Get entry for mutex listed in attribute
1110
93
            BeforeInfo *ArgInfo = getBeforeInfoForDecl(ArgVd, Analyzer);
1111
93
            ArgInfo->Vect.push_back(Vd);
1112
93
          }
1113
93
        }
1114
85
        break;
1115
0
      }
1116
0
      default:
1117
0
        break;
1118
137
    }
1119
137
  }
1120
747
1121
747
  return Info;
1122
747
}
1123
1124
BeforeSet::BeforeInfo *
1125
BeforeSet::getBeforeInfoForDecl(const ValueDecl *Vd,
1126
2.51k
                                ThreadSafetyAnalyzer &Analyzer) {
1127
2.51k
  auto It = BMap.find(Vd);
1128
2.51k
  BeforeInfo *Info = nullptr;
1129
2.51k
  if (It == BMap.end())
1130
707
    Info = insertAttrExprs(Vd, Analyzer);
1131
1.81k
  else
1132
1.81k
    Info = It->second.get();
1133
2.51k
  assert(Info && "BMap contained nullptr?");
1134
2.51k
  return Info;
1135
2.51k
}
1136
1137
/// Return true if any mutexes in FSet are in the acquired_before set of Vd.
1138
void BeforeSet::checkBeforeAfter(const ValueDecl* StartVd,
1139
                                 const FactSet& FSet,
1140
                                 ThreadSafetyAnalyzer& Analyzer,
1141
1.97k
                                 SourceLocation Loc, StringRef CapKind) {
1142
1.97k
  SmallVector<BeforeInfo*, 8> InfoVect;
1143
1.97k
1144
1.97k
  // Do a depth-first traversal of Vd.
1145
1.97k
  // Return true if there are cycles.
1146
2.46k
  std::function<bool (const ValueDecl*)> traverse = [&](const ValueDecl* Vd) {
1147
2.46k
    if (!Vd)
1148
44
      return false;
1149
2.42k
1150
2.42k
    BeforeSet::BeforeInfo *Info = getBeforeInfoForDecl(Vd, Analyzer);
1151
2.42k
1152
2.42k
    if (Info->Visited == 1)
1153
32
      return true;
1154
2.39k
1155
2.39k
    if (Info->Visited == 2)
1156
16
      return false;
1157
2.37k
1158
2.37k
    if (Info->Vect.empty())
1159
1.92k
      return false;
1160
450
1161
450
    InfoVect.push_back(Info);
1162
450
    Info->Visited = 1;
1163
490
    for (const auto *Vdb : Info->Vect) {
1164
490
      // Exclude mutexes in our immediate before set.
1165
490
      if (FSet.containsMutexDecl(Analyzer.FactMan, Vdb)) {
1166
49
        StringRef L1 = StartVd->getName();
1167
49
        StringRef L2 = Vdb->getName();
1168
49
        Analyzer.Handler.handleLockAcquiredBefore(CapKind, L1, L2, Loc);
1169
49
      }
1170
490
      // Transitively search other before sets, and warn on cycles.
1171
490
      if (traverse(Vdb)) {
1172
32
        if (CycMap.find(Vd) == CycMap.end()) {
1173
20
          CycMap.insert(std::make_pair(Vd, true));
1174
20
          StringRef L1 = Vd->getName();
1175
20
          Analyzer.Handler.handleBeforeAfterCycle(L1, Vd->getLocation());
1176
20
        }
1177
32
      }
1178
490
    }
1179
450
    Info->Visited = 2;
1180
450
    return false;
1181
450
  };
1182
1.97k
1183
1.97k
  traverse(StartVd);
1184
1.97k
1185
1.97k
  for (auto *Info : InfoVect)
1186
450
    Info->Visited = 0;
1187
1.97k
}
1188
1189
/// Gets the value decl pointer from DeclRefExprs or MemberExprs.
1190
17.6k
static const ValueDecl *getValueDecl(const Expr *Exp) {
1191
17.6k
  if (const auto *CE = dyn_cast<ImplicitCastExpr>(Exp))
1192
0
    return getValueDecl(CE->getSubExpr());
1193
17.6k
1194
17.6k
  if (const auto *DR = dyn_cast<DeclRefExpr>(Exp))
1195
4.87k
    return DR->getDecl();
1196
12.7k
1197
12.7k
  if (const auto *ME = dyn_cast<MemberExpr>(Exp))
1198
8.13k
    return ME->getMemberDecl();
1199
4.64k
1200
4.64k
  return nullptr;
1201
4.64k
}
1202
1203
namespace {
1204
1205
template <typename Ty>
1206
class has_arg_iterator_range {
1207
  using yes = char[1];
1208
  using no = char[2];
1209
1210
  template <typename Inner>
1211
  static yes& test(Inner *I, decltype(I->args()) * = nullptr);
1212
1213
  template <typename>
1214
  static no& test(...);
1215
1216
public:
1217
  static const bool value = sizeof(test<Ty>(nullptr)) == sizeof(yes);
1218
};
1219
1220
} // namespace
1221
1222
3.96k
static StringRef ClassifyDiagnostic(const CapabilityAttr *A) {
1223
3.96k
  return A->getName();
1224
3.96k
}
1225
1226
4.49k
static StringRef ClassifyDiagnostic(QualType VDT) {
1227
4.49k
  // We need to look at the declaration of the type of the value to determine
1228
4.49k
  // which it is. The type should either be a record or a typedef, or a pointer
1229
4.49k
  // or reference thereof.
1230
4.49k
  if (const auto *RT = VDT->getAs<RecordType>()) {
1231
4.07k
    if (const auto *RD = RT->getDecl())
1232
4.07k
      if (const auto *CA = RD->getAttr<CapabilityAttr>())
1233
3.92k
        return ClassifyDiagnostic(CA);
1234
417
  } else if (const auto *TT = VDT->getAs<TypedefType>()) {
1235
44
    if (const auto *TD = TT->getDecl())
1236
44
      if (const auto *CA = TD->getAttr<CapabilityAttr>())
1237
44
        return ClassifyDiagnostic(CA);
1238
373
  } else if (VDT->isPointerType() || 
VDT->isReferenceType()6
)
1239
369
    return ClassifyDiagnostic(VDT->getPointeeType());
1240
156
1241
156
  return "mutex";
1242
156
}
1243
1244
4.12k
static StringRef ClassifyDiagnostic(const ValueDecl *VD) {
1245
4.12k
  assert(VD && "No ValueDecl passed");
1246
4.12k
1247
4.12k
  // The ValueDecl is the declaration of a mutex or role (hopefully).
1248
4.12k
  return ClassifyDiagnostic(VD->getType());
1249
4.12k
}
1250
1251
template <typename AttrTy>
1252
static std::enable_if_t<!has_arg_iterator_range<AttrTy>::value, StringRef>
1253
2.30k
ClassifyDiagnostic(const AttrTy *A) {
1254
2.30k
  if (const ValueDecl *VD = getValueDecl(A->getArg()))
1255
2.11k
    return ClassifyDiagnostic(VD);
1256
184
  return "mutex";
1257
184
}
ThreadSafety.cpp:std::__1::enable_if<!(has_arg_iterator_range<clang::PtGuardedByAttr>::value), llvm::StringRef>::type ClassifyDiagnostic<clang::PtGuardedByAttr>(clang::PtGuardedByAttr const*)
Line
Count
Source
1253
388
ClassifyDiagnostic(const AttrTy *A) {
1254
388
  if (const ValueDecl *VD = getValueDecl(A->getArg()))
1255
388
    return ClassifyDiagnostic(VD);
1256
0
  return "mutex";
1257
0
}
ThreadSafety.cpp:std::__1::enable_if<!(has_arg_iterator_range<clang::GuardedByAttr>::value), llvm::StringRef>::type ClassifyDiagnostic<clang::GuardedByAttr>(clang::GuardedByAttr const*)
Line
Count
Source
1253
1.91k
ClassifyDiagnostic(const AttrTy *A) {
1254
1.91k
  if (const ValueDecl *VD = getValueDecl(A->getArg()))
1255
1.72k
    return ClassifyDiagnostic(VD);
1256
184
  return "mutex";
1257
184
}
1258
1259
template <typename AttrTy>
1260
static std::enable_if_t<has_arg_iterator_range<AttrTy>::value, StringRef>
1261
5.35k
ClassifyDiagnostic(const AttrTy *A) {
1262
5.35k
  for (const auto *Arg : A->args()) {
1263
2.36k
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
2.00k
      return ClassifyDiagnostic(VD);
1265
2.36k
  }
1266
5.35k
  
return "mutex"3.34k
;
1267
5.35k
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::RequiresCapabilityAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::RequiresCapabilityAttr>(clang::RequiresCapabilityAttr const*)
Line
Count
Source
1261
1.03k
ClassifyDiagnostic(const AttrTy *A) {
1262
1.06k
  for (const auto *Arg : A->args()) {
1263
1.06k
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
832
      return ClassifyDiagnostic(VD);
1265
1.06k
  }
1266
1.03k
  
return "mutex"202
;
1267
1.03k
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::ReleaseCapabilityAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::ReleaseCapabilityAttr>(clang::ReleaseCapabilityAttr const*)
Line
Count
Source
1261
1.96k
ClassifyDiagnostic(const AttrTy *A) {
1262
1.96k
  for (const auto *Arg : A->args()) {
1263
459
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
415
      return ClassifyDiagnostic(VD);
1265
459
  }
1266
1.96k
  
return "mutex"1.55k
;
1267
1.96k
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::AcquireCapabilityAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::AcquireCapabilityAttr>(clang::AcquireCapabilityAttr const*)
Line
Count
Source
1261
1.80k
ClassifyDiagnostic(const AttrTy *A) {
1262
1.80k
  for (const auto *Arg : A->args()) {
1263
576
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
520
      return ClassifyDiagnostic(VD);
1265
576
  }
1266
1.80k
  
return "mutex"1.28k
;
1267
1.80k
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::TryAcquireCapabilityAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::TryAcquireCapabilityAttr>(clang::TryAcquireCapabilityAttr const*)
Line
Count
Source
1261
168
ClassifyDiagnostic(const AttrTy *A) {
1262
168
  for (const auto *Arg : A->args()) {
1263
52
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
48
      return ClassifyDiagnostic(VD);
1265
52
  }
1266
168
  
return "mutex"120
;
1267
168
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::ExclusiveTrylockFunctionAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::ExclusiveTrylockFunctionAttr>(clang::ExclusiveTrylockFunctionAttr const*)
Line
Count
Source
1261
156
ClassifyDiagnostic(const AttrTy *A) {
1262
156
  for (const auto *Arg : A->args()) {
1263
44
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
40
      return ClassifyDiagnostic(VD);
1265
44
  }
1266
156
  
return "mutex"116
;
1267
156
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::SharedTrylockFunctionAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::SharedTrylockFunctionAttr>(clang::SharedTrylockFunctionAttr const*)
Line
Count
Source
1261
12
ClassifyDiagnostic(const AttrTy *A) {
1262
12
  for (const auto *Arg : A->args()) {
1263
8
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
8
      return ClassifyDiagnostic(VD);
1265
8
  }
1266
12
  
return "mutex"4
;
1267
12
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::AssertExclusiveLockAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::AssertExclusiveLockAttr>(clang::AssertExclusiveLockAttr const*)
Line
Count
Source
1261
34
ClassifyDiagnostic(const AttrTy *A) {
1262
34
  for (const auto *Arg : A->args()) {
1263
10
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
10
      return ClassifyDiagnostic(VD);
1265
10
  }
1266
34
  
return "mutex"24
;
1267
34
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::AssertSharedLockAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::AssertSharedLockAttr>(clang::AssertSharedLockAttr const*)
Line
Count
Source
1261
10
ClassifyDiagnostic(const AttrTy *A) {
1262
10
  for (const auto *Arg : A->args()) {
1263
8
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
8
      return ClassifyDiagnostic(VD);
1265
8
  }
1266
10
  
return "mutex"2
;
1267
10
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::AssertCapabilityAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::AssertCapabilityAttr>(clang::AssertCapabilityAttr const*)
Line
Count
Source
1261
44
ClassifyDiagnostic(const AttrTy *A) {
1262
44
  for (const auto *Arg : A->args()) {
1263
18
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
18
      return ClassifyDiagnostic(VD);
1265
18
  }
1266
44
  
return "mutex"26
;
1267
44
}
ThreadSafety.cpp:std::__1::enable_if<has_arg_iterator_range<clang::LocksExcludedAttr>::value, llvm::StringRef>::type ClassifyDiagnostic<clang::LocksExcludedAttr>(clang::LocksExcludedAttr const*)
Line
Count
Source
1261
126
ClassifyDiagnostic(const AttrTy *A) {
1262
126
  for (const auto *Arg : A->args()) {
1263
126
    if (const ValueDecl *VD = getValueDecl(Arg))
1264
110
      return ClassifyDiagnostic(VD);
1265
126
  }
1266
126
  
return "mutex"16
;
1267
126
}
1268
1269
1.88k
bool ThreadSafetyAnalyzer::inCurrentScope(const CapabilityExpr &CapE) {
1270
1.88k
  if (!CurrentMethod)
1271
921
      return false;
1272
967
  if (const auto *P = dyn_cast_or_null<til::Project>(CapE.sexpr())) {
1273
807
    const auto *VD = P->clangDecl();
1274
807
    if (VD)
1275
807
      return VD->getDeclContext() == CurrentMethod->getDeclContext();
1276
160
  }
1277
160
  return false;
1278
160
}
1279
1280
/// Add a new lock to the lockset, warning if the lock is already there.
1281
/// \param ReqAttr -- true if this is part of an initial Requires attribute.
1282
void ThreadSafetyAnalyzer::addLock(FactSet &FSet,
1283
                                   std::unique_ptr<FactEntry> Entry,
1284
2.64k
                                   StringRef DiagKind, bool ReqAttr) {
1285
2.64k
  if (Entry->shouldIgnore())
1286
0
    return;
1287
2.64k
1288
2.64k
  if (!ReqAttr && 
!Entry->negative()2.13k
) {
1289
2.13k
    // look for the negative capability, and remove it from the fact set.
1290
2.13k
    CapabilityExpr NegC = !*Entry;
1291
2.13k
    const FactEntry *Nen = FSet.findLock(FactMan, NegC);
1292
2.13k
    if (Nen) {
1293
274
      FSet.removeLock(FactMan, NegC);
1294
274
    }
1295
1.86k
    else {
1296
1.86k
      if (inCurrentScope(*Entry) && 
!Entry->asserted()731
)
1297
643
        Handler.handleNegativeNotHeld(DiagKind, Entry->toString(),
1298
643
                                      NegC.toString(), Entry->loc());
1299
1.86k
    }
1300
2.13k
  }
1301
2.64k
1302
2.64k
  // Check before/after constraints
1303
2.64k
  if (Handler.issueBetaWarnings() &&
1304
2.64k
      
!Entry->asserted()2.56k
&&
!Entry->declared()2.47k
) {
1305
1.97k
    GlobalBeforeSet->checkBeforeAfter(Entry->valueDecl(), FSet, *this,
1306
1.97k
                                      Entry->loc(), DiagKind);
1307
1.97k
  }
1308
2.64k
1309
2.64k
  // FIXME: Don't always warn when we have support for reentrant locks.
1310
2.64k
  if (const FactEntry *Cp = FSet.findLock(FactMan, *Entry)) {
1311
143
    if (!Entry->asserted())
1312
115
      Cp->handleLock(FSet, FactMan, *Entry, Handler, DiagKind);
1313
2.49k
  } else {
1314
2.49k
    FSet.addLock(FactMan, std::move(Entry));
1315
2.49k
  }
1316
2.64k
}
1317
1318
/// Remove a lock from the lockset, warning if the lock is not there.
1319
/// \param UnlockLoc The source location of the unlock (only used in error msg)
1320
void ThreadSafetyAnalyzer::removeLock(FactSet &FSet, const CapabilityExpr &Cp,
1321
                                      SourceLocation UnlockLoc,
1322
                                      bool FullyRemove, LockKind ReceivedKind,
1323
1.84k
                                      StringRef DiagKind) {
1324
1.84k
  if (Cp.shouldIgnore())
1325
0
    return;
1326
1.84k
1327
1.84k
  const FactEntry *LDat = FSet.findLock(FactMan, Cp);
1328
1.84k
  if (!LDat) {
1329
84
    Handler.handleUnmatchedUnlock(DiagKind, Cp.toString(), UnlockLoc);
1330
84
    return;
1331
84
  }
1332
1.75k
1333
1.75k
  // Generic lock removal doesn't care about lock kind mismatches, but
1334
1.75k
  // otherwise diagnose when the lock kinds are mismatched.
1335
1.75k
  if (ReceivedKind != LK_Generic && 
LDat->kind() != ReceivedKind182
) {
1336
18
    Handler.handleIncorrectUnlockKind(DiagKind, Cp.toString(), LDat->kind(),
1337
18
                                      ReceivedKind, LDat->loc(), UnlockLoc);
1338
18
  }
1339
1.75k
1340
1.75k
  LDat->handleUnlock(FSet, FactMan, Cp, UnlockLoc, FullyRemove, Handler,
1341
1.75k
                     DiagKind);
1342
1.75k
}
1343
1344
/// Extract the list of mutexIDs from the attribute on an expression,
1345
/// and push them onto Mtxs, discarding any duplicates.
1346
template <typename AttrType>
1347
void ThreadSafetyAnalyzer::getMutexIDs(CapExprSet &Mtxs, AttrType *Attr,
1348
                                       const Expr *Exp, const NamedDecl *D,
1349
4.50k
                                       VarDecl *SelfDecl) {
1350
4.50k
  if (Attr->args_size() == 0) {
1351
2.90k
    // The mutex held is the "this" object.
1352
2.90k
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
2.90k
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
2.90k
    //else
1358
2.90k
    if (!Cp.shouldIgnore())
1359
2.90k
      Mtxs.push_back_nodup(Cp);
1360
2.90k
    return;
1361
2.90k
  }
1362
1.60k
1363
1.95k
  
for (const auto *Arg : Attr->args())1.60k
{
1364
1.95k
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
1.95k
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
1.95k
    //else
1370
1.95k
    if (!Cp.shouldIgnore())
1371
1.94k
      Mtxs.push_back_nodup(Cp);
1372
1.95k
  }
1373
1.60k
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::RequiresCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::RequiresCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
414
                                       VarDecl *SelfDecl) {
1350
414
  if (Attr->args_size() == 0) {
1351
0
    // The mutex held is the "this" object.
1352
0
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
0
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
0
    //else
1358
0
    if (!Cp.shouldIgnore())
1359
0
      Mtxs.push_back_nodup(Cp);
1360
0
    return;
1361
0
  }
1362
414
1363
466
  
for (const auto *Arg : Attr->args())414
{
1364
466
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
466
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
466
    //else
1370
466
    if (!Cp.shouldIgnore())
1371
466
      Mtxs.push_back_nodup(Cp);
1372
466
  }
1373
414
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::ReleaseCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::ReleaseCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
2.04k
                                       VarDecl *SelfDecl) {
1350
2.04k
  if (Attr->args_size() == 0) {
1351
1.51k
    // The mutex held is the "this" object.
1352
1.51k
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
1.51k
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
1.51k
    //else
1358
1.51k
    if (!Cp.shouldIgnore())
1359
1.51k
      Mtxs.push_back_nodup(Cp);
1360
1.51k
    return;
1361
1.51k
  }
1362
536
1363
696
  
for (const auto *Arg : Attr->args())536
{
1364
696
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
696
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
696
    //else
1370
696
    if (!Cp.shouldIgnore())
1371
692
      Mtxs.push_back_nodup(Cp);
1372
696
  }
1373
536
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::AcquireCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::AcquireCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
1.80k
                                       VarDecl *SelfDecl) {
1350
1.80k
  if (Attr->args_size() == 0) {
1351
1.22k
    // The mutex held is the "this" object.
1352
1.22k
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
1.22k
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
1.22k
    //else
1358
1.22k
    if (!Cp.shouldIgnore())
1359
1.22k
      Mtxs.push_back_nodup(Cp);
1360
1.22k
    return;
1361
1.22k
  }
1362
576
1363
708
  
for (const auto *Arg : Attr->args())576
{
1364
708
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
708
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
708
    //else
1370
708
    if (!Cp.shouldIgnore())
1371
700
      Mtxs.push_back_nodup(Cp);
1372
708
  }
1373
576
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::TryAcquireCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::TryAcquireCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
84
                                       VarDecl *SelfDecl) {
1350
84
  if (Attr->args_size() == 0) {
1351
58
    // The mutex held is the "this" object.
1352
58
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
58
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
58
    //else
1358
58
    if (!Cp.shouldIgnore())
1359
58
      Mtxs.push_back_nodup(Cp);
1360
58
    return;
1361
58
  }
1362
26
1363
26
  for (const auto *Arg : Attr->args()) {
1364
26
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
26
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
26
    //else
1370
26
    if (!Cp.shouldIgnore())
1371
26
      Mtxs.push_back_nodup(Cp);
1372
26
  }
1373
26
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::ExclusiveTrylockFunctionAttr const>((anonymous namespace)::CapExprSet&, clang::ExclusiveTrylockFunctionAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
78
                                       VarDecl *SelfDecl) {
1350
78
  if (Attr->args_size() == 0) {
1351
56
    // The mutex held is the "this" object.
1352
56
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
56
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
56
    //else
1358
56
    if (!Cp.shouldIgnore())
1359
56
      Mtxs.push_back_nodup(Cp);
1360
56
    return;
1361
56
  }
1362
22
1363
22
  for (const auto *Arg : Attr->args()) {
1364
22
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
22
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
22
    //else
1370
22
    if (!Cp.shouldIgnore())
1371
22
      Mtxs.push_back_nodup(Cp);
1372
22
  }
1373
22
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::SharedTrylockFunctionAttr const>((anonymous namespace)::CapExprSet&, clang::SharedTrylockFunctionAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
6
                                       VarDecl *SelfDecl) {
1350
6
  if (Attr->args_size() == 0) {
1351
2
    // The mutex held is the "this" object.
1352
2
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
2
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
2
    //else
1358
2
    if (!Cp.shouldIgnore())
1359
2
      Mtxs.push_back_nodup(Cp);
1360
2
    return;
1361
2
  }
1362
4
1363
4
  for (const auto *Arg : Attr->args()) {
1364
4
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
4
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
4
    //else
1370
4
    if (!Cp.shouldIgnore())
1371
4
      Mtxs.push_back_nodup(Cp);
1372
4
  }
1373
4
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::AssertExclusiveLockAttr const>((anonymous namespace)::CapExprSet&, clang::AssertExclusiveLockAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
32
                                       VarDecl *SelfDecl) {
1350
32
  if (Attr->args_size() == 0) {
1351
24
    // The mutex held is the "this" object.
1352
24
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
24
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
24
    //else
1358
24
    if (!Cp.shouldIgnore())
1359
24
      Mtxs.push_back_nodup(Cp);
1360
24
    return;
1361
24
  }
1362
8
1363
10
  
for (const auto *Arg : Attr->args())8
{
1364
10
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
10
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
10
    //else
1370
10
    if (!Cp.shouldIgnore())
1371
10
      Mtxs.push_back_nodup(Cp);
1372
10
  }
1373
8
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::AssertSharedLockAttr const>((anonymous namespace)::CapExprSet&, clang::AssertSharedLockAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
8
                                       VarDecl *SelfDecl) {
1350
8
  if (Attr->args_size() == 0) {
1351
2
    // The mutex held is the "this" object.
1352
2
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
2
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
2
    //else
1358
2
    if (!Cp.shouldIgnore())
1359
2
      Mtxs.push_back_nodup(Cp);
1360
2
    return;
1361
2
  }
1362
6
1363
8
  
for (const auto *Arg : Attr->args())6
{
1364
8
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
8
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
8
    //else
1370
8
    if (!Cp.shouldIgnore())
1371
8
      Mtxs.push_back_nodup(Cp);
1372
8
  }
1373
6
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::AssertCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::AssertCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::VarDecl*)
Line
Count
Source
1349
40
                                       VarDecl *SelfDecl) {
1350
40
  if (Attr->args_size() == 0) {
1351
26
    // The mutex held is the "this" object.
1352
26
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(nullptr, D, Exp, SelfDecl);
1353
26
    if (Cp.isInvalid()) {
1354
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1355
0
       return;
1356
0
    }
1357
26
    //else
1358
26
    if (!Cp.shouldIgnore())
1359
26
      Mtxs.push_back_nodup(Cp);
1360
26
    return;
1361
26
  }
1362
14
1363
18
  
for (const auto *Arg : Attr->args())14
{
1364
18
    CapabilityExpr Cp = SxBuilder.translateAttrExpr(Arg, D, Exp, SelfDecl);
1365
18
    if (Cp.isInvalid()) {
1366
0
       warnInvalidLock(Handler, nullptr, D, Exp, ClassifyDiagnostic(Attr));
1367
0
       continue;
1368
0
    }
1369
18
    //else
1370
18
    if (!Cp.shouldIgnore())
1371
18
      Mtxs.push_back_nodup(Cp);
1372
18
  }
1373
14
}
1374
1375
/// Extract the list of mutexIDs from a trylock attribute.  If the
1376
/// trylock applies to the given edge, then push them onto Mtxs, discarding
1377
/// any duplicates.
1378
template <class AttrType>
1379
void ThreadSafetyAnalyzer::getMutexIDs(CapExprSet &Mtxs, AttrType *Attr,
1380
                                       const Expr *Exp, const NamedDecl *D,
1381
                                       const CFGBlock *PredBlock,
1382
                                       const CFGBlock *CurrBlock,
1383
336
                                       Expr *BrE, bool Neg) {
1384
336
  // Find out which branch has the lock
1385
336
  bool branch = false;
1386
336
  if (const auto *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE))
1387
272
    branch = BLE->getValue();
1388
64
  else if (const auto *ILE = dyn_cast_or_null<IntegerLiteral>(BrE))
1389
64
    branch = ILE->getValue().getBoolValue();
1390
336
1391
336
  int branchnum = branch ? 0 : 
10
;
1392
336
  if (Neg)
1393
144
    branchnum = !branchnum;
1394
336
1395
336
  // If we've taken the trylock branch, then add the lock
1396
336
  int i = 0;
1397
336
  for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(),
1398
1.00k
       SE = PredBlock->succ_end(); SI != SE && 
i < 2672
;
++SI, ++i672
) {
1399
672
    if (*SI == CurrBlock && 
i == branchnum336
)
1400
168
      getMutexIDs(Mtxs, Attr, Exp, D);
1401
672
  }
1402
336
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::TryAcquireCapabilityAttr const>((anonymous namespace)::CapExprSet&, clang::TryAcquireCapabilityAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::CFGBlock const*, clang::CFGBlock const*, clang::Expr*, bool)
Line
Count
Source
1383
168
                                       Expr *BrE, bool Neg) {
1384
168
  // Find out which branch has the lock
1385
168
  bool branch = false;
1386
168
  if (const auto *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE))
1387
136
    branch = BLE->getValue();
1388
32
  else if (const auto *ILE = dyn_cast_or_null<IntegerLiteral>(BrE))
1389
32
    branch = ILE->getValue().getBoolValue();
1390
168
1391
168
  int branchnum = branch ? 0 : 
10
;
1392
168
  if (Neg)
1393
72
    branchnum = !branchnum;
1394
168
1395
168
  // If we've taken the trylock branch, then add the lock
1396
168
  int i = 0;
1397
168
  for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(),
1398
504
       SE = PredBlock->succ_end(); SI != SE && 
i < 2336
;
++SI, ++i336
) {
1399
336
    if (*SI == CurrBlock && 
i == branchnum168
)
1400
84
      getMutexIDs(Mtxs, Attr, Exp, D);
1401
336
  }
1402
168
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::ExclusiveTrylockFunctionAttr const>((anonymous namespace)::CapExprSet&, clang::ExclusiveTrylockFunctionAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::CFGBlock const*, clang::CFGBlock const*, clang::Expr*, bool)
Line
Count
Source
1383
156
                                       Expr *BrE, bool Neg) {
1384
156
  // Find out which branch has the lock
1385
156
  bool branch = false;
1386
156
  if (const auto *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE))
1387
124
    branch = BLE->getValue();
1388
32
  else if (const auto *ILE = dyn_cast_or_null<IntegerLiteral>(BrE))
1389
32
    branch = ILE->getValue().getBoolValue();
1390
156
1391
156
  int branchnum = branch ? 0 : 
10
;
1392
156
  if (Neg)
1393
68
    branchnum = !branchnum;
1394
156
1395
156
  // If we've taken the trylock branch, then add the lock
1396
156
  int i = 0;
1397
156
  for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(),
1398
468
       SE = PredBlock->succ_end(); SI != SE && 
i < 2312
;
++SI, ++i312
) {
1399
312
    if (*SI == CurrBlock && 
i == branchnum156
)
1400
78
      getMutexIDs(Mtxs, Attr, Exp, D);
1401
312
  }
1402
156
}
ThreadSafety.cpp:void (anonymous namespace)::ThreadSafetyAnalyzer::getMutexIDs<clang::SharedTrylockFunctionAttr const>((anonymous namespace)::CapExprSet&, clang::SharedTrylockFunctionAttr const*, clang::Expr const*, clang::NamedDecl const*, clang::CFGBlock const*, clang::CFGBlock const*, clang::Expr*, bool)
Line
Count
Source
1383
12
                                       Expr *BrE, bool Neg) {
1384
12
  // Find out which branch has the lock
1385
12
  bool branch = false;
1386
12
  if (const auto *BLE = dyn_cast_or_null<CXXBoolLiteralExpr>(BrE))
1387
12
    branch = BLE->getValue();
1388
0
  else if (const auto *ILE = dyn_cast_or_null<IntegerLiteral>(BrE))
1389
0
    branch = ILE->getValue().getBoolValue();
1390
12
1391
12
  int branchnum = branch ? 0 : 
10
;
1392
12
  if (Neg)
1393
4
    branchnum = !branchnum;
1394
12
1395
12
  // If we've taken the trylock branch, then add the lock
1396
12
  int i = 0;
1397
12
  for (CFGBlock::const_succ_iterator SI = PredBlock->succ_begin(),
1398
36
       SE = PredBlock->succ_end(); SI != SE && 
i < 224
;
++SI, ++i24
) {
1399
24
    if (*SI == CurrBlock && 
i == branchnum12
)
1400
6
      getMutexIDs(Mtxs, Attr, Exp, D);
1401
24
  }
1402
12
}
1403
1404
496
static bool getStaticBooleanValue(Expr *E, bool &TCond) {
1405
496
  if (isa<CXXNullPtrLiteralExpr>(E) || 
isa<GNUNullExpr>(E)488
) {
1406
8
    TCond = false;
1407
8
    return true;
1408
488
  } else if (const auto *BLE = dyn_cast<CXXBoolLiteralExpr>(E)) {
1409
16
    TCond = BLE->getValue();
1410
16
    return true;
1411
472
  } else if (const auto *ILE = dyn_cast<IntegerLiteral>(E)) {
1412
360
    TCond = ILE->getValue().getBoolValue();
1413
360
    return true;
1414
360
  } else 
if (auto *112
CE112
= dyn_cast<ImplicitCastExpr>(E))
1415
80
    return getStaticBooleanValue(CE->getSubExpr(), TCond);
1416
32
  return false;
1417
32
}
1418
1419
// If Cond can be traced back to a function call, return the call expression.
1420
// The negate variable should be called with false, and will be set to true
1421
// if the function call is negated, e.g. if (!mu.tryLock(...))
1422
const CallExpr* ThreadSafetyAnalyzer::getTrylockCallExpr(const Stmt *Cond,
1423
                                                         LocalVarContext C,
1424
2.85k
                                                         bool &Negate) {
1425
2.85k
  if (!Cond)
1426
56
    return nullptr;
1427
2.79k
1428
2.79k
  if (const auto *CallExp = dyn_cast<CallExpr>(Cond)) {
1429
782
    if (CallExp->getBuiltinCallee() == Builtin::BI__builtin_expect)
1430
16
      return getTrylockCallExpr(CallExp->getArg(0), C, Negate);
1431
766
    return CallExp;
1432
766
  }
1433
2.01k
  else if (const auto *PE = dyn_cast<ParenExpr>(Cond))
1434
32
    return getTrylockCallExpr(PE->getSubExpr(), C, Negate);
1435
1.98k
  else if (const auto *CE = dyn_cast<ImplicitCastExpr>(Cond))
1436
768
    return getTrylockCallExpr(CE->getSubExpr(), C, Negate);
1437
1.21k
  else if (const auto *FE = dyn_cast<FullExpr>(Cond))
1438
8
    return getTrylockCallExpr(FE->getSubExpr(), C, Negate);
1439
1.20k
  else if (const auto *DRE = dyn_cast<DeclRefExpr>(Cond)) {
1440
168
    const Expr *E = LocalVarMap.lookupExpr(DRE->getDecl(), C);
1441
168
    return getTrylockCallExpr(E, C, Negate);
1442
168
  }
1443
1.04k
  else if (const auto *UOP = dyn_cast<UnaryOperator>(Cond)) {
1444
160
    if (UOP->getOpcode() == UO_LNot) {
1445
128
      Negate = !Negate;
1446
128
      return getTrylockCallExpr(UOP->getSubExpr(), C, Negate);
1447
128
    }
1448
32
    return nullptr;
1449
32
  }
1450
880
  else if (const auto *BOP = dyn_cast<BinaryOperator>(Cond)) {
1451
472
    if (BOP->getOpcode() == BO_EQ || 
BOP->getOpcode() == BO_NE152
) {
1452
344
      if (BOP->getOpcode() == BO_NE)
1453
24
        Negate = !Negate;
1454
344
1455
344
      bool TCond = false;
1456
344
      if (getStaticBooleanValue(BOP->getRHS(), TCond)) {
1457
320
        if (!TCond) 
Negate = !Negate208
;
1458
320
        return getTrylockCallExpr(BOP->getLHS(), C, Negate);
1459
320
      }
1460
24
      TCond = false;
1461
24
      if (getStaticBooleanValue(BOP->getLHS(), TCond)) {
1462
16
        if (!TCond) Negate = !Negate;
1463
16
        return getTrylockCallExpr(BOP->getRHS(), C, Negate);
1464
16
      }
1465
8
      return nullptr;
1466
8
    }
1467
128
    if (BOP->getOpcode() == BO_LAnd) {
1468
72
      // LHS must have been evaluated in a different block.
1469
72
      return getTrylockCallExpr(BOP->getRHS(), C, Negate);
1470
72
    }
1471
56
    if (BOP->getOpcode() == BO_LOr)
1472
24
      return getTrylockCallExpr(BOP->getRHS(), C, Negate);
1473
32
    return nullptr;
1474
408
  } else if (const auto *COP = dyn_cast<ConditionalOperator>(Cond)) {
1475
24
    bool TCond, FCond;
1476
24
    if (getStaticBooleanValue(COP->getTrueExpr(), TCond) &&
1477
24
        getStaticBooleanValue(COP->getFalseExpr(), FCond)) {
1478
24
      if (TCond && 
!FCond8
)
1479
8
        return getTrylockCallExpr(COP->getCond(), C, Negate);
1480
16
      if (!TCond && FCond) {
1481
16
        Negate = !Negate;
1482
16
        return getTrylockCallExpr(COP->getCond(), C, Negate);
1483
16
      }
1484
384
    }
1485
24
  }
1486
384
  return nullptr;
1487
384
}
1488
1489
/// Find the lockset that holds on the edge between PredBlock
1490
/// and CurrBlock.  The edge set is the exit set of PredBlock (passed
1491
/// as the ExitSet parameter) plus any trylocks, which are conditionally held.
1492
void ThreadSafetyAnalyzer::getEdgeLockset(FactSet& Result,
1493
                                          const FactSet &ExitSet,
1494
                                          const CFGBlock *PredBlock,
1495
5.85k
                                          const CFGBlock *CurrBlock) {
1496
5.85k
  Result = ExitSet;
1497
5.85k
1498
5.85k
  const Stmt *Cond = PredBlock->getTerminatorCondition();
1499
5.85k
  // We don't acquire try-locks on ?: branches, only when its result is used.
1500
5.85k
  if (!Cond || 
isa<ConditionalOperator>(PredBlock->getTerminatorStmt())1.35k
)
1501
4.57k
    return;
1502
1.27k
1503
1.27k
  bool Negate = false;
1504
1.27k
  const CFGBlockInfo *PredBlockInfo = &BlockInfo[PredBlock->getBlockID()];
1505
1.27k
  const LocalVarContext &LVarCtx = PredBlockInfo->ExitContext;
1506
1.27k
  StringRef CapDiagKind = "mutex";
1507
1.27k
1508
1.27k
  const auto *Exp = getTrylockCallExpr(Cond, LVarCtx, Negate);
1509
1.27k
  if (!Exp)
1510
512
    return;
1511
766
1512
766
  auto *FunDecl = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl());
1513
766
  if(!FunDecl || !FunDecl->hasAttrs())
1514
446
    return;
1515
320
1516
320
  CapExprSet ExclusiveLocksToAdd;
1517
320
  CapExprSet SharedLocksToAdd;
1518
320
1519
320
  // If the condition is a call to a Trylock function, then grab the attributes
1520
336
  for (const auto *Attr : FunDecl->attrs()) {
1521
336
    switch (Attr->getKind()) {
1522
168
      case attr::TryAcquireCapability: {
1523
168
        auto *A = cast<TryAcquireCapabilityAttr>(Attr);
1524
168
        getMutexIDs(A->isShared() ? 
SharedLocksToAdd12
:
ExclusiveLocksToAdd156
, A,
1525
168
                    Exp, FunDecl, PredBlock, CurrBlock, A->getSuccessValue(),
1526
168
                    Negate);
1527
168
        CapDiagKind = ClassifyDiagnostic(A);
1528
168
        break;
1529
0
      };
1530
156
      case attr::ExclusiveTrylockFunction: {
1531
156
        const auto *A = cast<ExclusiveTrylockFunctionAttr>(Attr);
1532
156
        getMutexIDs(ExclusiveLocksToAdd, A, Exp, FunDecl,
1533
156
                    PredBlock, CurrBlock, A->getSuccessValue(), Negate);
1534
156
        CapDiagKind = ClassifyDiagnostic(A);
1535
156
        break;
1536
0
      }
1537
12
      case attr::SharedTrylockFunction: {
1538
12
        const auto *A = cast<SharedTrylockFunctionAttr>(Attr);
1539
12
        getMutexIDs(SharedLocksToAdd, A, Exp, FunDecl,
1540
12
                    PredBlock, CurrBlock, A->getSuccessValue(), Negate);
1541
12
        CapDiagKind = ClassifyDiagnostic(A);
1542
12
        break;
1543
0
      }
1544
0
      default:
1545
0
        break;
1546
336
    }
1547
336
  }
1548
320
1549
320
  // Add and remove locks.
1550
320
  SourceLocation Loc = Exp->getExprLoc();
1551
320
  for (const auto &ExclusiveLockToAdd : ExclusiveLocksToAdd)
1552
156
    addLock(Result, std::make_unique<LockableFactEntry>(ExclusiveLockToAdd,
1553
156
                                                         LK_Exclusive, Loc),
1554
156
            CapDiagKind);
1555
320
  for (const auto &SharedLockToAdd : SharedLocksToAdd)
1556
12
    addLock(Result, std::make_unique<LockableFactEntry>(SharedLockToAdd,
1557
12
                                                         LK_Shared, Loc),
1558
12
            CapDiagKind);
1559
320
}
1560
1561
namespace {
1562
1563
/// We use this class to visit different types of expressions in
1564
/// CFGBlocks, and build up the lockset.
1565
/// An expression may cause us to add or remove locks from the lockset, or else
1566
/// output error messages related to missing locks.
1567
/// FIXME: In future, we may be able to not inherit from a visitor.
1568
class BuildLockset : public ConstStmtVisitor<BuildLockset> {
1569
  friend class ThreadSafetyAnalyzer;
1570
1571
  ThreadSafetyAnalyzer *Analyzer;
1572
  FactSet FSet;
1573
  LocalVariableMap::Context LVarCtx;
1574
  unsigned CtxIndex;
1575
1576
  // helper functions
1577
  void warnIfMutexNotHeld(const NamedDecl *D, const Expr *Exp, AccessKind AK,
1578
                          Expr *MutexExp, ProtectedOperationKind POK,
1579
                          StringRef DiagKind, SourceLocation Loc);
1580
  void warnIfMutexHeld(const NamedDecl *D, const Expr *Exp, Expr *MutexExp,
1581
                       StringRef DiagKind);
1582
1583
  void checkAccess(const Expr *Exp, AccessKind AK,
1584
                   ProtectedOperationKind POK = POK_VarAccess);
1585
  void checkPtAccess(const Expr *Exp, AccessKind AK,
1586
                     ProtectedOperationKind POK = POK_VarAccess);
1587
1588
  void handleCall(const Expr *Exp, const NamedDecl *D, VarDecl *VD = nullptr);
1589
  void examineArguments(const FunctionDecl *FD,
1590
                        CallExpr::const_arg_iterator ArgBegin,
1591
                        CallExpr::const_arg_iterator ArgEnd,
1592
                        bool SkipFirstParam = false);
1593
1594
public:
1595
  BuildLockset(ThreadSafetyAnalyzer *Anlzr, CFGBlockInfo &Info)
1596
      : ConstStmtVisitor<BuildLockset>(), Analyzer(Anlzr), FSet(Info.EntrySet),
1597
7.27k
        LVarCtx(Info.EntryContext), CtxIndex(Info.EntryIndex) {}
1598
1599
  void VisitUnaryOperator(const UnaryOperator *UO);
1600
  void VisitBinaryOperator(const BinaryOperator *BO);
1601
  void VisitCastExpr(const CastExpr *CE);
1602
  void VisitCallExpr(const CallExpr *Exp);
1603
  void VisitCXXConstructExpr(const CXXConstructExpr *Exp);
1604
  void VisitDeclStmt(const DeclStmt *S);
1605
};
1606
1607
} // namespace
1608
1609
/// Warn if the LSet does not contain a lock sufficient to protect access
1610
/// of at least the passed in AccessKind.
1611
void BuildLockset::warnIfMutexNotHeld(const NamedDecl *D, const Expr *Exp,
1612
                                      AccessKind AK, Expr *MutexExp,
1613
                                      ProtectedOperationKind POK,
1614
2.93k
                                      StringRef DiagKind, SourceLocation Loc) {
1615
2.93k
  LockKind LK = getLockKindFromAccessKind(AK);
1616
2.93k
1617
2.93k
  CapabilityExpr Cp = Analyzer->SxBuilder.translateAttrExpr(MutexExp, D, Exp);
1618
2.93k
  if (Cp.isInvalid()) {
1619
0
    warnInvalidLock(Analyzer->Handler, MutexExp, D, Exp, DiagKind);
1620
0
    return;
1621
2.93k
  } else if (Cp.shouldIgnore()) {
1622
20
    return;
1623
20
  }
1624
2.91k
1625
2.91k
  if (Cp.negative()) {
1626
34
    // Negative capabilities act like locks excluded
1627
34
    const FactEntry *LDat = FSet.findLock(Analyzer->FactMan, !Cp);
1628
34
    if (LDat) {
1629
10
      Analyzer->Handler.handleFunExcludesLock(
1630
10
          DiagKind, D->getNameAsString(), (!Cp).toString(), Loc);
1631
10
      return;
1632
10
    }
1633
24
1634
24
    // If this does not refer to a negative capability in the same class,
1635
24
    // then stop here.
1636
24
    if (!Analyzer->inCurrentScope(Cp))
1637
10
      return;
1638
14
1639
14
    // Otherwise the negative requirement must be propagated to the caller.
1640
14
    LDat = FSet.findLock(Analyzer->FactMan, Cp);
1641
14
    if (!LDat) {
1642
6
      Analyzer->Handler.handleMutexNotHeld("", D, POK, Cp.toString(),
1643
6
                                           LK_Shared, Loc);
1644
6
    }
1645
14
    return;
1646
14
  }
1647
2.88k
1648
2.88k
  const FactEntry *LDat = FSet.findLockUniv(Analyzer->FactMan, Cp);
1649
2.88k
  bool NoError = true;
1650
2.88k
  if (!LDat) {
1651
1.14k
    // No exact match found.  Look for a partial match.
1652
1.14k
    LDat = FSet.findPartialMatch(Analyzer->FactMan, Cp);
1653
1.14k
    if (LDat) {
1654
76
      // Warn that there's no precise match.
1655
76
      std::string PartMatchStr = LDat->toString();
1656
76
      StringRef   PartMatchName(PartMatchStr);
1657
76
      Analyzer->Handler.handleMutexNotHeld(DiagKind, D, POK, Cp.toString(),
1658
76
                                           LK, Loc, &PartMatchName);
1659
1.06k
    } else {
1660
1.06k
      // Warn that there's no match at all.
1661
1.06k
      Analyzer->Handler.handleMutexNotHeld(DiagKind, D, POK, Cp.toString(),
1662
1.06k
                                           LK, Loc);
1663
1.06k
    }
1664
1.14k
    NoError = false;
1665
1.14k
  }
1666
2.88k
  // Make sure the mutex we found is the right kind.
1667
2.88k
  if (NoError && 
LDat1.74k
&&
!LDat->isAtLeast(LK)1.74k
) {
1668
28
    Analyzer->Handler.handleMutexNotHeld(DiagKind, D, POK, Cp.toString(),
1669
28
                                         LK, Loc);
1670
28
  }
1671
2.88k
}
1672
1673
/// Warn if the LSet contains the given lock.
1674
void BuildLockset::warnIfMutexHeld(const NamedDecl *D, const Expr *Exp,
1675
126
                                   Expr *MutexExp, StringRef DiagKind) {
1676
126
  CapabilityExpr Cp = Analyzer->SxBuilder.translateAttrExpr(MutexExp, D, Exp);
1677
126
  if (Cp.isInvalid()) {
1678
0
    warnInvalidLock(Analyzer->Handler, MutexExp, D, Exp, DiagKind);
1679
0
    return;
1680
126
  } else if (Cp.shouldIgnore()) {
1681
0
    return;
1682
0
  }
1683
126
1684
126
  const FactEntry *LDat = FSet.findLock(Analyzer->FactMan, Cp);
1685
126
  if (LDat) {
1686
67
    Analyzer->Handler.handleFunExcludesLock(
1687
67
        DiagKind, D->getNameAsString(), Cp.toString(), Exp->getExprLoc());
1688
67
  }
1689
126
}
1690
1691
/// Checks guarded_by and pt_guarded_by attributes.
1692
/// Whenever we identify an access (read or write) to a DeclRefExpr that is
1693
/// marked with guarded_by, we must ensure the appropriate mutexes are held.
1694
/// Similarly, we check if the access is to an expression that dereferences
1695
/// a pointer marked with pt_guarded_by.
1696
void BuildLockset::checkAccess(const Expr *Exp, AccessKind AK,
1697
8.53k
                               ProtectedOperationKind POK) {
1698
8.53k
  Exp = Exp->IgnoreImplicit()->IgnoreParenCasts();
1699
8.53k
1700
8.53k
  SourceLocation Loc = Exp->getExprLoc();
1701
8.53k
1702
8.53k
  // Local variables of reference type cannot be re-assigned;
1703
8.53k
  // map them to their initializer.
1704
8.57k
  while (const auto *DRE = dyn_cast<DeclRefExpr>(Exp)) {
1705
3.55k
    const auto *VD = dyn_cast<VarDecl>(DRE->getDecl()->getCanonicalDecl());
1706
3.55k
    if (VD && VD->isLocalVarDecl() && 
VD->getType()->isReferenceType()1.67k
) {
1707
44
      if (const auto *E = VD->getInit()) {
1708
44
        // Guard against self-initialization. e.g., int &i = i;
1709
44
        if (E == Exp)
1710
0
          break;
1711
44
        Exp = E;
1712
44
        continue;
1713
44
      }
1714
44
    }
1715
3.51k
    break;
1716
3.51k
  }
1717
8.53k
1718
8.53k
  if (const auto *UO = dyn_cast<UnaryOperator>(Exp)) {
1719
250
    // For dereferences
1720
250
    if (UO->getOpcode() == UO_Deref)
1721
250
      checkPtAccess(UO->getSubExpr(), AK, POK);
1722
250
    return;
1723
250
  }
1724
8.28k
1725
8.28k
  if (const auto *AE = dyn_cast<ArraySubscriptExpr>(Exp)) {
1726
68
    checkPtAccess(AE->getLHS(), AK, POK);
1727
68
    return;
1728
68
  }
1729
8.21k
1730
8.21k
  if (const auto *ME = dyn_cast<MemberExpr>(Exp)) {
1731
4.22k
    if (ME->isArrow())
1732
3.42k
      checkPtAccess(ME->getBase(), AK, POK);
1733
799
    else
1734
799
      checkAccess(ME->getBase(), AK, POK);
1735
4.22k
  }
1736
8.21k
1737
8.21k
  const ValueDecl *D = getValueDecl(Exp);
1738
8.21k
  if (!D || 
!D->hasAttrs()7.73k
)
1739
5.74k
    return;
1740
2.46k
1741
2.46k
  if (D->hasAttr<GuardedVarAttr>() && 
FSet.isEmpty(Analyzer->FactMan)48
) {
1742
25
    Analyzer->Handler.handleNoMutexHeld("mutex", D, POK, AK, Loc);
1743
25
  }
1744
2.46k
1745
2.46k
  for (const auto *I : D->specific_attrs<GuardedByAttr>())
1746
1.91k
    warnIfMutexNotHeld(D, Exp, AK, I->getArg(), POK,
1747
1.91k
                       ClassifyDiagnostic(I), Loc);
1748
2.46k
}
1749
1750
/// Checks pt_guarded_by and pt_guarded_var attributes.
1751
/// POK is the same  operationKind that was passed to checkAccess.
1752
void BuildLockset::checkPtAccess(const Expr *Exp, AccessKind AK,
1753
4.83k
                                 ProtectedOperationKind POK) {
1754
6.01k
  while (true) {
1755
6.01k
    if (const auto *PE = dyn_cast<ParenExpr>(Exp)) {
1756
4
      Exp = PE->getSubExpr();
1757
4
      continue;
1758
4
    }
1759
6.00k
    if (const auto *CE = dyn_cast<CastExpr>(Exp)) {
1760
1.23k
      if (CE->getCastKind() == CK_ArrayToPointerDecay) {
1761
60
        // If it's an actual array, and not a pointer, then it's elements
1762
60
        // are protected by GUARDED_BY, not PT_GUARDED_BY;
1763
60
        checkAccess(CE->getSubExpr(), AK, POK);
1764
60
        return;
1765
60
      }
1766
1.17k
      Exp = CE->getSubExpr();
1767
1.17k
      continue;
1768
1.17k
    }
1769
4.77k
    break;
1770
4.77k
  }
1771
4.83k
1772
4.83k
  // Pass by reference warnings are under a different flag.
1773
4.83k
  ProtectedOperationKind PtPOK = POK_VarDereference;
1774
4.77k
  if (POK == POK_PassByRef) 
PtPOK = POK_PtPassByRef130
;
1775
4.77k
1776
4.77k
  const ValueDecl *D = getValueDecl(Exp);
1777
4.77k
  if (!D || 
!D->hasAttrs()1.14k
)
1778
4.33k
    return;
1779
442
1780
442
  if (D->hasAttr<PtGuardedVarAttr>() && 
FSet.isEmpty(Analyzer->FactMan)10
)
1781
9
    Analyzer->Handler.handleNoMutexHeld("mutex", D, PtPOK, AK,
1782
9
                                        Exp->getExprLoc());
1783
442
1784
442
  for (auto const *I : D->specific_attrs<PtGuardedByAttr>())
1785
388
    warnIfMutexNotHeld(D, Exp, AK, I->getArg(), PtPOK,
1786
388
                       ClassifyDiagnostic(I), Exp->getExprLoc());
1787
442
}
1788
1789
/// Process a function call, method call, constructor call,
1790
/// or destructor call.  This involves looking at the attributes on the
1791
/// corresponding function/method/constructor/destructor, issuing warnings,
1792
/// and updating the locksets accordingly.
1793
///
1794
/// FIXME: For classes annotated with one of the guarded annotations, we need
1795
/// to treat const method calls as reads and non-const method calls as writes,
1796
/// and check that the appropriate locks are held. Non-const method calls with
1797
/// the same signature as const method calls can be also treated as reads.
1798
///
1799
void BuildLockset::handleCall(const Expr *Exp, const NamedDecl *D,
1800
4.30k
                              VarDecl *VD) {
1801
4.30k
  SourceLocation Loc = Exp->getExprLoc();
1802
4.30k
  CapExprSet ExclusiveLocksToAdd, SharedLocksToAdd;
1803
4.30k
  CapExprSet ExclusiveLocksToRemove, SharedLocksToRemove, GenericLocksToRemove;
1804
4.30k
  CapExprSet ScopedExclusiveReqs, ScopedSharedReqs;
1805
4.30k
  StringRef CapDiagKind = "mutex";
1806
4.30k
1807
4.30k
  // Figure out if we're constructing an object of scoped lockable class
1808
4.30k
  bool isScopedVar = false;
1809
4.30k
  if (VD) {
1810
242
    if (const auto *CD = dyn_cast<const CXXConstructorDecl>(D)) {
1811
242
      const CXXRecordDecl* PD = CD->getParent();
1812
242
      if (PD && PD->hasAttr<ScopedLockableAttr>())
1813
222
        isScopedVar = true;
1814
242
    }
1815
242
  }
1816
4.30k
1817
4.64k
  for(const Attr *At : D->attrs()) {
1818
4.64k
    switch (At->getKind()) {
1819
0
      // When we encounter a lock function, we need to add the lock to our
1820
0
      // lockset.
1821
1.71k
      case attr::AcquireCapability: {
1822
1.71k
        const auto *A = cast<AcquireCapabilityAttr>(At);
1823
1.71k
        Analyzer->getMutexIDs(A->isShared() ? 
SharedLocksToAdd193
1824
1.71k
                                            : 
ExclusiveLocksToAdd1.51k
,
1825
1.71k
                              A, Exp, D, VD);
1826
1.71k
1827
1.71k
        CapDiagKind = ClassifyDiagnostic(A);
1828
1.71k
        break;
1829
0
      }
1830
0
1831
0
      // An assert will add a lock to the lockset, but will not generate
1832
0
      // a warning if it is already there, and will not generate a warning
1833
0
      // if it is not removed.
1834
32
      case attr::AssertExclusiveLock: {
1835
32
        const auto *A = cast<AssertExclusiveLockAttr>(At);
1836
32
1837
32
        CapExprSet AssertLocks;
1838
32
        Analyzer->getMutexIDs(AssertLocks, A, Exp, D, VD);
1839
32
        for (const auto &AssertLock : AssertLocks)
1840
34
          Analyzer->addLock(FSet,
1841
34
                            std::make_unique<LockableFactEntry>(
1842
34
                                AssertLock, LK_Exclusive, Loc, false, true),
1843
34
                            ClassifyDiagnostic(A));
1844
32
        break;
1845
0
      }
1846
8
      case attr::AssertSharedLock: {
1847
8
        const auto *A = cast<AssertSharedLockAttr>(At);
1848
8
1849
8
        CapExprSet AssertLocks;
1850
8
        Analyzer->getMutexIDs(AssertLocks, A, Exp, D, VD);
1851
8
        for (const auto &AssertLock : AssertLocks)
1852
10
          Analyzer->addLock(FSet,
1853
10
                            std::make_unique<LockableFactEntry>(
1854
10
                                AssertLock, LK_Shared, Loc, false, true),
1855
10
                            ClassifyDiagnostic(A));
1856
8
        break;
1857
0
      }
1858
0
1859
40
      case attr::AssertCapability: {
1860
40
        const auto *A = cast<AssertCapabilityAttr>(At);
1861
40
        CapExprSet AssertLocks;
1862
40
        Analyzer->getMutexIDs(AssertLocks, A, Exp, D, VD);
1863
40
        for (const auto &AssertLock : AssertLocks)
1864
44
          Analyzer->addLock(FSet,
1865
44
                            std::make_unique<LockableFactEntry>(
1866
44
                                AssertLock,
1867
44
                                A->isShared() ? 
LK_Shared10
:
LK_Exclusive34
, Loc,
1868
44
                                false, true),
1869
44
                            ClassifyDiagnostic(A));
1870
40
        break;
1871
0
      }
1872
0
1873
0
      // When we encounter an unlock function, we need to remove unlocked
1874
0
      // mutexes from the lockset, and flag a warning if they are not there.
1875
1.89k
      case attr::ReleaseCapability: {
1876
1.89k
        const auto *A = cast<ReleaseCapabilityAttr>(At);
1877
1.89k
        if (A->isGeneric())
1878
1.70k
          Analyzer->getMutexIDs(GenericLocksToRemove, A, Exp, D, VD);
1879
188
        else if (A->isShared())
1880
38
          Analyzer->getMutexIDs(SharedLocksToRemove, A, Exp, D, VD);
1881
150
        else
1882
150
          Analyzer->getMutexIDs(ExclusiveLocksToRemove, A, Exp, D, VD);
1883
1.89k
1884
1.89k
        CapDiagKind = ClassifyDiagnostic(A);
1885
1.89k
        break;
1886
0
      }
1887
0
1888
572
      case attr::RequiresCapability: {
1889
572
        const auto *A = cast<RequiresCapabilityAttr>(At);
1890
636
        for (auto *Arg : A->args()) {
1891
636
          warnIfMutexNotHeld(D, Exp, A->isShared() ? 
AK_Read111
:
AK_Written525
, Arg,
1892
636
                             POK_FunctionCall, ClassifyDiagnostic(A),
1893
636
                             Exp->getExprLoc());
1894
636
          // use for adopting a lock
1895
636
          if (isScopedVar) {
1896
16
            Analyzer->getMutexIDs(A->isShared() ? 
ScopedSharedReqs8
1897
16
                                                : 
ScopedExclusiveReqs8
,
1898
16
                                  A, Exp, D, VD);
1899
16
          }
1900
636
        }
1901
572
        break;
1902
0
      }
1903
0
1904
116
      case attr::LocksExcluded: {
1905
116
        const auto *A = cast<LocksExcludedAttr>(At);
1906
116
        for (auto *Arg : A->args())
1907
126
          warnIfMutexHeld(D, Exp, Arg, ClassifyDiagnostic(A));
1908
116
        break;
1909
0
      }
1910
0
1911
0
      // Ignore attributes unrelated to thread-safety
1912
273
      default:
1913
273
        break;
1914
4.64k
    }
1915
4.64k
  }
1916
4.30k
1917
4.30k
  // Remove locks first to allow lock upgrading/downgrading.
1918
4.30k
  // FIXME -- should only fully remove if the attribute refers to 'this'.
1919
4.30k
  bool Dtor = isa<CXXDestructorDecl>(D);
1920
4.30k
  for (const auto &M : ExclusiveLocksToRemove)
1921
150
    Analyzer->removeLock(FSet, M, Loc, Dtor, LK_Exclusive, CapDiagKind);
1922
4.30k
  for (const auto &M : SharedLocksToRemove)
1923
38
    Analyzer->removeLock(FSet, M, Loc, Dtor, LK_Shared, CapDiagKind);
1924
4.30k
  for (const auto &M : GenericLocksToRemove)
1925
1.65k
    Analyzer->removeLock(FSet, M, Loc, Dtor, LK_Generic, CapDiagKind);
1926
4.30k
1927
4.30k
  // Add locks.
1928
4.30k
  for (const auto &M : ExclusiveLocksToAdd)
1929
1.47k
    Analyzer->addLock(FSet, std::make_unique<LockableFactEntry>(
1930
1.47k
                                M, LK_Exclusive, Loc, isScopedVar),
1931
1.47k
                      CapDiagKind);
1932
4.30k
  for (const auto &M : SharedLocksToAdd)
1933
181
    Analyzer->addLock(FSet, std::make_unique<LockableFactEntry>(
1934
181
                                M, LK_Shared, Loc, isScopedVar),
1935
181
                      CapDiagKind);
1936
4.30k
1937
4.30k
  if (isScopedVar) {
1938
222
    // Add the managing object as a dummy mutex, mapped to the underlying mutex.
1939
222
    SourceLocation MLoc = VD->getLocation();
1940
222
    DeclRefExpr DRE(VD->getASTContext(), VD, false, VD->getType(), VK_LValue,
1941
222
                    VD->getLocation());
1942
222
    // FIXME: does this store a pointer to DRE?
1943
222
    CapabilityExpr Scp = Analyzer->SxBuilder.translateAttrExpr(&DRE, nullptr);
1944
222
1945
222
    auto ScopedEntry = std::make_unique<ScopedLockableFactEntry>(Scp, MLoc);
1946
222
    for (const auto &M : ExclusiveLocksToAdd)
1947
154
      ScopedEntry->addExclusiveLock(M);
1948
222
    for (const auto &M : ScopedExclusiveReqs)
1949
8
      ScopedEntry->addExclusiveLock(M);
1950
222
    for (const auto &M : SharedLocksToAdd)
1951
20
      ScopedEntry->addSharedLock(M);
1952
222
    for (const auto &M : ScopedSharedReqs)
1953
8
      ScopedEntry->addSharedLock(M);
1954
222
    for (const auto &M : ExclusiveLocksToRemove)
1955
28
      ScopedEntry->addExclusiveUnlock(M);
1956
222
    for (const auto &M : SharedLocksToRemove)
1957
8
      ScopedEntry->addSharedUnlock(M);
1958
222
    Analyzer->addLock(FSet, std::move(ScopedEntry), CapDiagKind);
1959
222
  }
1960
4.30k
}
1961
1962
/// For unary operations which read and write a variable, we need to
1963
/// check whether we hold any required mutexes. Reads are checked in
1964
/// VisitCastExpr.
1965
728
void BuildLockset::VisitUnaryOperator(const UnaryOperator *UO) {
1966
728
  switch (UO->getOpcode()) {
1967
28
    case UO_PostDec:
1968
28
    case UO_PostInc:
1969
28
    case UO_PreDec:
1970
28
    case UO_PreInc:
1971
28
      checkAccess(UO->getSubExpr(), AK_Written);
1972
28
      break;
1973
700
    default:
1974
700
      break;
1975
728
  }
1976
728
}
1977
1978
/// For binary operations which assign to a variable (writes), we need to check
1979
/// whether we hold any required mutexes.
1980
/// FIXME: Deal with non-primitive types.
1981
1.84k
void BuildLockset::VisitBinaryOperator(const BinaryOperator *BO) {
1982
1.84k
  if (!BO->isAssignmentOp())
1983
377
    return;
1984
1.47k
1985
1.47k
  // adjust the context
1986
1.47k
  LVarCtx = Analyzer->LocalVarMap.getNextContext(CtxIndex, BO, LVarCtx);
1987
1.47k
1988
1.47k
  checkAccess(BO->getLHS(), AK_Written);
1989
1.47k
}
1990
1991
/// Whenever we do an LValue to Rvalue cast, we are reading a variable and
1992
/// need to ensure we hold any required mutexes.
1993
/// FIXME: Deal with non-primitive types.
1994
4.68k
void BuildLockset::VisitCastExpr(const CastExpr *CE) {
1995
4.68k
  if (CE->getCastKind() != CK_LValueToRValue)
1996
2.42k
    return;
1997
2.26k
  checkAccess(CE->getSubExpr(), AK_Read);
1998
2.26k
}
1999
2000
void BuildLockset::examineArguments(const FunctionDecl *FD,
2001
                                    CallExpr::const_arg_iterator ArgBegin,
2002
                                    CallExpr::const_arg_iterator ArgEnd,
2003
5.76k
                                    bool SkipFirstParam) {
2004
5.76k
  // Currently we can't do anything if we don't know the function declaration.
2005
5.76k
  if (!FD)
2006
12
    return;
2007
5.75k
2008
5.75k
  // NO_THREAD_SAFETY_ANALYSIS does double duty here.  Normally it
2009
5.75k
  // only turns off checking within the body of a function, but we also
2010
5.75k
  // use it to turn off checking in arguments to the function.  This
2011
5.75k
  // could result in some false negatives, but the alternative is to
2012
5.75k
  // create yet another attribute.
2013
5.75k
  if (FD->hasAttr<NoThreadSafetyAnalysisAttr>())
2014
40
    return;
2015
5.71k
2016
5.71k
  const ArrayRef<ParmVarDecl *> Params = FD->parameters();
2017
5.71k
  auto Param = Params.begin();
2018
5.71k
  if (SkipFirstParam)
2019
12
    ++Param;
2020
5.71k
2021
5.71k
  // There can be default arguments, so we stop when one iterator is at end().
2022
6.96k
  for (auto Arg = ArgBegin; Param != Params.end() && 
Arg != ArgEnd1.25k
;
2023
5.71k
       
++Param, ++Arg1.25k
) {
2024
1.25k
    QualType Qt = (*Param)->getType();
2025
1.25k
    if (Qt->isReferenceType())
2026
251
      checkAccess(*Arg, AK_Read, POK_PassByRef);
2027
1.25k
  }
2028
5.71k
}
2029
2030
5.25k
void BuildLockset::VisitCallExpr(const CallExpr *Exp) {
2031
5.25k
  if (const auto *CE = dyn_cast<CXXMemberCallExpr>(Exp)) {
2032
3.92k
    const auto *ME = dyn_cast<MemberExpr>(CE->getCallee());
2033
3.92k
    // ME can be null when calling a method pointer
2034
3.92k
    const CXXMethodDecl *MD = CE->getMethodDecl();
2035
3.92k
2036
3.92k
    if (ME && 
MD3.92k
) {
2037
3.92k
      if (ME->isArrow()) {
2038
752
        if (MD->isConst())
2039
16
          checkPtAccess(CE->getImplicitObjectArgument(), AK_Read);
2040
736
        else // FIXME -- should be AK_Written
2041
736
          checkPtAccess(CE->getImplicitObjectArgument(), AK_Read);
2042
3.16k
      } else {
2043
3.16k
        if (MD->isConst())
2044
136
          checkAccess(CE->getImplicitObjectArgument(), AK_Read);
2045
3.03k
        else     // FIXME -- should be AK_Written
2046
3.03k
          checkAccess(CE->getImplicitObjectArgument(), AK_Read);
2047
3.16k
      }
2048
3.92k
    }
2049
3.92k
2050
3.92k
    examineArguments(CE->getDirectCallee(), CE->arg_begin(), CE->arg_end());
2051
3.92k
  } else 
if (const auto *1.32k
OE1.32k
= dyn_cast<CXXOperatorCallExpr>(Exp)) {
2052
432
    auto OEop = OE->getOperator();
2053
432
    switch (OEop) {
2054
32
      case OO_Equal: {
2055
32
        const Expr *Target = OE->getArg(0);
2056
32
        const Expr *Source = OE->getArg(1);
2057
32
        checkAccess(Target, AK_Written);
2058
32
        checkAccess(Source, AK_Read);
2059
32
        break;
2060
0
      }
2061
344
      case OO_Star:
2062
344
      case OO_Arrow:
2063
344
      case OO_Subscript:
2064
344
        if (!(OEop == OO_Star && 
OE->getNumArgs() > 1116
)) {
2065
340
          // Grrr.  operator* can be multiplication...
2066
340
          checkPtAccess(OE->getArg(0), AK_Read);
2067
340
        }
2068
344
        LLVM_FALLTHROUGH;
2069
400
      default: {
2070
400
        // TODO: get rid of this, and rely on pass-by-ref instead.
2071
400
        const Expr *Obj = OE->getArg(0);
2072
400
        checkAccess(Obj, AK_Read);
2073
400
        // Check the remaining arguments. For method operators, the first
2074
400
        // argument is the implicit self argument, and doesn't appear in the
2075
400
        // FunctionDecl, but for non-methods it does.
2076
400
        const FunctionDecl *FD = OE->getDirectCallee();
2077
400
        examineArguments(FD, std::next(OE->arg_begin()), OE->arg_end(),
2078
400
                         /*SkipFirstParam*/ !isa<CXXMethodDecl>(FD));
2079
400
        break;
2080
896
      }
2081
896
    }
2082
896
  } else {
2083
896
    examineArguments(Exp->getDirectCallee(), Exp->arg_begin(), Exp->arg_end());
2084
896
  }
2085
5.25k
2086
5.25k
  auto *D = dyn_cast_or_null<NamedDecl>(Exp->getCalleeDecl());
2087
5.25k
  if(!D || !D->hasAttrs())
2088
1.40k
    return;
2089
3.84k
  handleCall(Exp, D);
2090
3.84k
}
2091
2092
577
void BuildLockset::VisitCXXConstructExpr(const CXXConstructExpr *Exp) {
2093
577
  const CXXConstructorDecl *D = Exp->getConstructor();
2094
577
  if (D && D->isCopyConstructor()) {
2095
31
    const Expr* Source = Exp->getArg(0);
2096
31
    checkAccess(Source, AK_Read);
2097
546
  } else {
2098
546
    examineArguments(D, Exp->arg_begin(), Exp->arg_end());
2099
546
  }
2100
577
}
2101
2102
static CXXConstructorDecl *
2103
2
findConstructorForByValueReturn(const CXXRecordDecl *RD) {
2104
2
  // Prefer a move constructor over a copy constructor. If there's more than
2105
2
  // one copy constructor or more than one move constructor, we arbitrarily
2106
2
  // pick the first declared such constructor rather than trying to guess which
2107
2
  // one is more appropriate.
2108
2
  CXXConstructorDecl *CopyCtor = nullptr;
2109
4
  for (auto *Ctor : RD->ctors()) {
2110
4
    if (Ctor->isDeleted())
2111
0
      continue;
2112
4
    if (Ctor->isMoveConstructor())
2113
2
      return Ctor;
2114
2
    if (!CopyCtor && Ctor->isCopyConstructor())
2115
0
      CopyCtor = Ctor;
2116
2
  }
2117
2
  
return CopyCtor0
;
2118
2
}
2119
2120
static Expr *buildFakeCtorCall(CXXConstructorDecl *CD, ArrayRef<Expr *> Args,
2121
2
                               SourceLocation Loc) {
2122
2
  ASTContext &Ctx = CD->getASTContext();
2123
2
  return CXXConstructExpr::Create(Ctx, Ctx.getRecordType(CD->getParent()), Loc,
2124
2
                                  CD, true, Args, false, false, false, false,
2125
2
                                  CXXConstructExpr::CK_Complete,
2126
2
                                  SourceRange(Loc, Loc));
2127
2
}
2128
2129
892
void BuildLockset::VisitDeclStmt(const DeclStmt *S) {
2130
892
  // adjust the context
2131
892
  LVarCtx = Analyzer->LocalVarMap.getNextContext(CtxIndex, S, LVarCtx);
2132
892
2133
892
  for (auto *D : S->getDeclGroup()) {
2134
892
    if (auto *VD = dyn_cast_or_null<VarDecl>(D)) {
2135
892
      Expr *E = VD->getInit();
2136
892
      if (!E)
2137
96
        continue;
2138
796
      E = E->IgnoreParens();
2139
796
2140
796
      // handle constructors that involve temporaries
2141
796
      if (auto *EWC = dyn_cast<ExprWithCleanups>(E))
2142
31
        E = EWC->getSubExpr();
2143
796
      if (auto *ICE = dyn_cast<ImplicitCastExpr>(E))
2144
150
        if (ICE->getCastKind() == CK_NoOp)
2145
6
          E = ICE->getSubExpr();
2146
796
      if (auto *BTE = dyn_cast<CXXBindTemporaryExpr>(E))
2147
6
        E = BTE->getSubExpr();
2148
796
2149
796
      if (const auto *CE = dyn_cast<CXXConstructExpr>(E)) {
2150
461
        const auto *CtorD = dyn_cast_or_null<NamedDecl>(CE->getConstructor());
2151
461
        if (!CtorD || !CtorD->hasAttrs())
2152
221
          continue;
2153
240
        handleCall(E, CtorD, VD);
2154
335
      } else if (isa<CallExpr>(E) && 
E->isRValue()70
) {
2155
70
        // If the object is initialized by a function call that returns a
2156
70
        // scoped lockable by value, use the attributes on the copy or move
2157
70
        // constructor to figure out what effect that should have on the
2158
70
        // lockset.
2159
70
        // FIXME: Is this really the best way to handle this situation?
2160
70
        auto *RD = E->getType()->getAsCXXRecordDecl();
2161
70
        if (!RD || 
!RD->hasAttr<ScopedLockableAttr>()2
)
2162
68
          continue;
2163
2
        CXXConstructorDecl *CtorD = findConstructorForByValueReturn(RD);
2164
2
        if (!CtorD || !CtorD->hasAttrs())
2165
0
          continue;
2166
2
        handleCall(buildFakeCtorCall(CtorD, {E}, E->getBeginLoc()), CtorD, VD);
2167
2
      }
2168
796
    }
2169
892
  }
2170
892
}
2171
2172
/// Compute the intersection of two locksets and issue warnings for any
2173
/// locks in the symmetric difference.
2174
///
2175
/// This function is used at a merge point in the CFG when comparing the lockset
2176
/// of each branch being merged. For example, given the following sequence:
2177
/// A; if () then B; else C; D; we need to check that the lockset after B and C
2178
/// are the same. In the event of a difference, we use the intersection of these
2179
/// two locksets at the start of D.
2180
///
2181
/// \param FSet1 The first lockset.
2182
/// \param FSet2 The second lockset.
2183
/// \param JoinLoc The location of the join point for error reporting
2184
/// \param LEK1 The error message to report if a mutex is missing from LSet1
2185
/// \param LEK2 The error message to report if a mutex is missing from Lset2
2186
void ThreadSafetyAnalyzer::intersectAndWarn(FactSet &FSet1,
2187
                                            const FactSet &FSet2,
2188
                                            SourceLocation JoinLoc,
2189
                                            LockErrorKind LEK1,
2190
                                            LockErrorKind LEK2,
2191
2.63k
                                            bool Modify) {
2192
2.63k
  FactSet FSet1Orig = FSet1;
2193
2.63k
2194
2.63k
  // Find locks in FSet2 that conflict or are not in FSet1, and warn.
2195
2.63k
  for (const auto &Fact : FSet2) {
2196
2.32k
    const FactEntry *LDat1 = nullptr;
2197
2.32k
    const FactEntry *LDat2 = &FactMan[Fact];
2198
2.32k
    FactSet::iterator Iter1  = FSet1.findLockIter(FactMan, *LDat2);
2199
2.32k
    if (Iter1 != FSet1.end()) 
LDat1 = &FactMan[*Iter1]979
;
2200
2.32k
2201
2.32k
    if (LDat1) {
2202
979
      if (LDat1->kind() != LDat2->kind()) {
2203
20
        Handler.handleExclusiveAndShared("mutex", LDat2->toString(),
2204
20
                                         LDat2->loc(), LDat1->loc());
2205
20
        if (Modify && 
LDat1->kind() != LK_Exclusive12
) {
2206
8
          // Take the exclusive lock, which is the one in FSet2.
2207
8
          *Iter1 = Fact;
2208
8
        }
2209
20
      }
2210
959
      else if (Modify && 
LDat1->asserted()457
&&
!LDat2->asserted()12
) {
2211
8
        // The non-asserted lock in FSet2 is the one we want to track.
2212
8
        *Iter1 = Fact;
2213
8
      }
2214
1.34k
    } else {
2215
1.34k
      LDat2->handleRemovalFromIntersection(FSet2, FactMan, JoinLoc, LEK1,
2216
1.34k
                                           Handler);
2217
1.34k
    }
2218
2.32k
  }
2219
2.63k
2220
2.63k
  // Find locks in FSet1 that are not in FSet2, and remove them.
2221
2.63k
  for (const auto &Fact : FSet1Orig) {
2222
1.22k
    const FactEntry *LDat1 = &FactMan[Fact];
2223
1.22k
    const FactEntry *LDat2 = FSet2.findLock(FactMan, *LDat1);
2224
1.22k
2225
1.22k
    if (!LDat2) {
2226
244
      LDat1->handleRemovalFromIntersection(FSet1Orig, FactMan, JoinLoc, LEK2,
2227
244
                                           Handler);
2228
244
      if (Modify)
2229
156
        FSet1.removeLock(FactMan, *LDat1);
2230
244
    }
2231
1.22k
  }
2232
2.63k
}
2233
2234
// Return true if block B never continues to its successors.
2235
5.88k
static bool neverReturns(const CFGBlock *B) {
2236
5.88k
  if (B->hasNoReturnElement())
2237
24
    return true;
2238
5.86k
  if (B->empty())
2239
2.00k
    return false;
2240
3.85k
2241
3.85k
  CFGElement Last = B->back();
2242
3.85k
  if (Optional<CFGStmt> S = Last.getAs<CFGStmt>()) {
2243
3.61k
    if (isa<CXXThrowExpr>(S->getStmt()))
2244
4
      return true;
2245
3.84k
  }
2246
3.84k
  return false;
2247
3.84k
}
2248
2249
/// Check a function's CFG for thread-safety violations.
2250
///
2251
/// We traverse the blocks in the CFG, compute the set of mutexes that are held
2252
/// at the end of each block, and issue warnings for thread safety violations.
2253
/// Each block in the CFG is traversed exactly once.
2254
2.14k
void ThreadSafetyAnalyzer::runAnalysis(AnalysisDeclContext &AC) {
2255
2.14k
  // TODO: this whole function needs be rewritten as a visitor for CFGWalker.
2256
2.14k
  // For now, we just use the walker to set things up.
2257
2.14k
  threadSafety::CFGWalker walker;
2258
2.14k
  if (!walker.init(AC))
2259
3
    return;
2260
2.14k
2261
2.14k
  // AC.dumpCFG(true);
2262
2.14k
  // threadSafety::printSCFG(walker);
2263
2.14k
2264
2.14k
  CFG *CFGraph = walker.getGraph();
2265
2.14k
  const NamedDecl *D = walker.getDecl();
2266
2.14k
  const auto *CurrentFunction = dyn_cast<FunctionDecl>(D);
2267
2.14k
  CurrentMethod = dyn_cast<CXXMethodDecl>(D);
2268
2.14k
2269
2.14k
  if (D->hasAttr<NoThreadSafetyAnalysisAttr>())
2270
36
    return;
2271
2.10k
2272
2.10k
  // FIXME: Do something a bit more intelligent inside constructor and
2273
2.10k
  // destructor code.  Constructors and destructors must assume unique access
2274
2.10k
  // to 'this', so checks on member variable access is disabled, but we should
2275
2.10k
  // still enable checks on other objects.
2276
2.10k
  if (isa<CXXConstructorDecl>(D))
2277
51
    return;  // Don't check inside constructors.
2278
2.05k
  if (isa<CXXDestructorDecl>(D))
2279
26
    return;  // Don't check inside destructors.
2280
2.02k
2281
2.02k
  Handler.enterFunction(CurrentFunction);
2282
2.02k
2283
2.02k
  BlockInfo.resize(CFGraph->getNumBlockIDs(),
2284
2.02k
    CFGBlockInfo::getEmptyBlockInfo(LocalVarMap));
2285
2.02k
2286
2.02k
  // We need to explore the CFG via a "topological" ordering.
2287
2.02k
  // That way, we will be guaranteed to have information about required
2288
2.02k
  // predecessor locksets when exploring a new block.
2289
2.02k
  const PostOrderCFGView *SortedGraph = walker.getSortedGraph();
2290
2.02k
  PostOrderCFGView::CFGBlockSet VisitedBlocks(CFGraph);
2291
2.02k
2292
2.02k
  // Mark entry block as reachable
2293
2.02k
  BlockInfo[CFGraph->getEntry().getBlockID()].Reachable = true;
2294
2.02k
2295
2.02k
  // Compute SSA names for local variables
2296
2.02k
  LocalVarMap.traverseCFG(CFGraph, SortedGraph, BlockInfo);
2297
2.02k
2298
2.02k
  // Fill in source locations for all CFGBlocks.
2299
2.02k
  findBlockLocations(CFGraph, SortedGraph, BlockInfo);
2300
2.02k
2301
2.02k
  CapExprSet ExclusiveLocksAcquired;
2302
2.02k
  CapExprSet SharedLocksAcquired;
2303
2.02k
  CapExprSet LocksReleased;
2304
2.02k
2305
2.02k
  // Add locks from exclusive_locks_required and shared_locks_required
2306
2.02k
  // to initial lockset. Also turn off checking for lock and unlock functions.
2307
2.02k
  // FIXME: is there a more intelligent way to check lock/unlock functions?
2308
2.02k
  if (!SortedGraph->empty() && D->hasAttrs()) {
2309
542
    const CFGBlock *FirstBlock = *SortedGraph->begin();
2310
542
    FactSet &InitialLockset = BlockInfo[FirstBlock->getBlockID()].EntrySet;
2311
542
2312
542
    CapExprSet ExclusiveLocksToAdd;
2313
542
    CapExprSet SharedLocksToAdd;
2314
542
    StringRef CapDiagKind = "mutex";
2315
542
2316
542
    SourceLocation Loc = D->getLocation();
2317
672
    for (const auto *Attr : D->attrs()) {
2318
672
      Loc = Attr->getLocation();
2319
672
      if (const auto *A = dyn_cast<RequiresCapabilityAttr>(Attr)) {
2320
398
        getMutexIDs(A->isShared() ? 
SharedLocksToAdd59
:
ExclusiveLocksToAdd339
, A,
2321
398
                    nullptr, D);
2322
398
        CapDiagKind = ClassifyDiagnostic(A);
2323
398
      } else 
if (const auto *274
A274
= dyn_cast<ReleaseCapabilityAttr>(Attr)) {
2324
91
        // UNLOCK_FUNCTION() is used to hide the underlying lock implementation.
2325
91
        // We must ignore such methods.
2326
91
        if (A->args_size() == 0)
2327
14
          return;
2328
77
        getMutexIDs(A->isShared() ? 
SharedLocksToAdd8
:
ExclusiveLocksToAdd69
, A,
2329
77
                    nullptr, D);
2330
77
        getMutexIDs(LocksReleased, A, nullptr, D);
2331
77
        CapDiagKind = ClassifyDiagnostic(A);
2332
183
      } else if (const auto *A = dyn_cast<AcquireCapabilityAttr>(Attr)) {
2333
106
        if (A->args_size() == 0)
2334
18
          return;
2335
88
        getMutexIDs(A->isShared() ? 
SharedLocksAcquired28
2336
88
                                  : 
ExclusiveLocksAcquired60
,
2337
88
                    A, nullptr, D);
2338
88
        CapDiagKind = ClassifyDiagnostic(A);
2339
88
      } else 
if (77
isa<ExclusiveTrylockFunctionAttr>(Attr)77
) {
2340
4
        // Don't try to check trylock functions for now.
2341
4
        return;
2342
73
      } else if (isa<SharedTrylockFunctionAttr>(Attr)) {
2343
2
        // Don't try to check trylock functions for now.
2344
2
        return;
2345
71
      } else if (isa<TryAcquireCapabilityAttr>(Attr)) {
2346
6
        // Don't try to check trylock functions for now.
2347
6
        return;
2348
6
      }
2349
672
    }
2350
542
2351
542
    // FIXME -- Loc can be wrong here.
2352
542
    
for (const auto &Mu : ExclusiveLocksToAdd)498
{
2353
420
      auto Entry = std::make_unique<LockableFactEntry>(Mu, LK_Exclusive, Loc);
2354
420
      Entry->setDeclared(true);
2355
420
      addLock(InitialLockset, std::move(Entry), CapDiagKind, true);
2356
420
    }
2357
498
    for (const auto &Mu : SharedLocksToAdd) {
2358
83
      auto Entry = std::make_unique<LockableFactEntry>(Mu, LK_Shared, Loc);
2359
83
      Entry->setDeclared(true);
2360
83
      addLock(InitialLockset, std::move(Entry), CapDiagKind, true);
2361
83
    }
2362
498
  }
2363
2.02k
2364
7.28k
  
for (const auto *CurrBlock : *SortedGraph)1.98k
{
2365
7.28k
    unsigned CurrBlockID = CurrBlock->getBlockID();
2366
7.28k
    CFGBlockInfo *CurrBlockInfo = &BlockInfo[CurrBlockID];
2367
7.28k
2368
7.28k
    // Use the default initial lockset in case there are no predecessors.
2369
7.28k
    VisitedBlocks.insert(CurrBlock);
2370
7.28k
2371
7.28k
    // Iterate through the predecessor blocks and warn if the lockset for all
2372
7.28k
    // predecessors is not the same. We take the entry lockset of the current
2373
7.28k
    // block to be the intersection of all previous locksets.
2374
7.28k
    // FIXME: By keeping the intersection, we may output more errors in future
2375
7.28k
    // for a lock which is not in the intersection, but was in the union. We
2376
7.28k
    // may want to also keep the union in future. As an example, let's say
2377
7.28k
    // the intersection contains Mutex L, and the union contains L and M.
2378
7.28k
    // Later we unlock M. At this point, we would output an error because we
2379
7.28k
    // never locked M; although the real error is probably that we forgot to
2380
7.28k
    // lock M on all code paths. Conversely, let's say that later we lock M.
2381
7.28k
    // In this case, we should compare against the intersection instead of the
2382
7.28k
    // union because the real error is probably that we forgot to unlock M on
2383
7.28k
    // all code paths.
2384
7.28k
    bool LocksetInitialized = false;
2385
7.28k
    SmallVector<CFGBlock *, 8> SpecialBlocks;
2386
7.28k
    for (CFGBlock::const_pred_iterator PI = CurrBlock->pred_begin(),
2387
13.2k
         PE  = CurrBlock->pred_end(); PI != PE; 
++PI5.99k
) {
2388
5.99k
      // if *PI -> CurrBlock is a back edge
2389
5.99k
      if (*PI == nullptr || !VisitedBlocks.alreadySet(*PI))
2390
106
        continue;
2391
5.88k
2392
5.88k
      unsigned PrevBlockID = (*PI)->getBlockID();
2393
5.88k
      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
2394
5.88k
2395
5.88k
      // Ignore edges from blocks that can't return.
2396
5.88k
      if (neverReturns(*PI) || 
!PrevBlockInfo->Reachable5.85k
)
2397
28
        continue;
2398
5.85k
2399
5.85k
      // Okay, we can reach this block from the entry.
2400
5.85k
      CurrBlockInfo->Reachable = true;
2401
5.85k
2402
5.85k
      // If the previous block ended in a 'continue' or 'break' statement, then
2403
5.85k
      // a difference in locksets is probably due to a bug in that block, rather
2404
5.85k
      // than in some other predecessor. In that case, keep the other
2405
5.85k
      // predecessor's lockset.
2406
5.85k
      if (const Stmt *Terminator = (*PI)->getTerminatorStmt()) {
2407
1.38k
        if (isa<ContinueStmt>(Terminator) || 
isa<BreakStmt>(Terminator)1.36k
) {
2408
26
          SpecialBlocks.push_back(*PI);
2409
26
          continue;
2410
26
        }
2411
5.83k
      }
2412
5.83k
2413
5.83k
      FactSet PrevLockset;
2414
5.83k
      getEdgeLockset(PrevLockset, PrevBlockInfo->ExitSet, *PI, CurrBlock);
2415
5.83k
2416
5.83k
      if (!LocksetInitialized) {
2417
5.28k
        CurrBlockInfo->EntrySet = PrevLockset;
2418
5.28k
        LocksetInitialized = true;
2419
5.28k
      } else {
2420
543
        intersectAndWarn(CurrBlockInfo->EntrySet, PrevLockset,
2421
543
                         CurrBlockInfo->EntryLoc,
2422
543
                         LEK_LockedSomePredecessors);
2423
543
      }
2424
5.83k
    }
2425
7.28k
2426
7.28k
    // Skip rest of block if it's not reachable.
2427
7.28k
    if (!CurrBlockInfo->Reachable)
2428
16
      continue;
2429
7.27k
2430
7.27k
    // Process continue and break blocks. Assume that the lockset for the
2431
7.27k
    // resulting block is unaffected by any discrepancies in them.
2432
7.27k
    for (const auto *PrevBlock : SpecialBlocks) {
2433
26
      unsigned PrevBlockID = PrevBlock->getBlockID();
2434
26
      CFGBlockInfo *PrevBlockInfo = &BlockInfo[PrevBlockID];
2435
26
2436
26
      if (!LocksetInitialized) {
2437
0
        CurrBlockInfo->EntrySet = PrevBlockInfo->ExitSet;
2438
0
        LocksetInitialized = true;
2439
26
      } else {
2440
26
        // Determine whether this edge is a loop terminator for diagnostic
2441
26
        // purposes. FIXME: A 'break' statement might be a loop terminator, but
2442
26
        // it might also be part of a switch. Also, a subsequent destructor
2443
26
        // might add to the lockset, in which case the real issue might be a
2444
26
        // double lock on the other path.
2445
26
        const Stmt *Terminator = PrevBlock->getTerminatorStmt();
2446
26
        bool IsLoop = Terminator && isa<ContinueStmt>(Terminator);
2447
26
2448
26
        FactSet PrevLockset;
2449
26
        getEdgeLockset(PrevLockset, PrevBlockInfo->ExitSet,
2450
26
                       PrevBlock, CurrBlock);
2451
26
2452
26
        // Do not update EntrySet.
2453
26
        intersectAndWarn(CurrBlockInfo->EntrySet, PrevLockset,
2454
26
                         PrevBlockInfo->ExitLoc,
2455
26
                         IsLoop ? 
LEK_LockedSomeLoopIterations16
2456
26
                                : 
LEK_LockedSomePredecessors10
,
2457
26
                         false);
2458
26
      }
2459
26
    }
2460
7.27k
2461
7.27k
    BuildLockset LocksetBuilder(this, *CurrBlockInfo);
2462
7.27k
2463
7.27k
    // Visit all the statements in the basic block.
2464
33.7k
    for (const auto &BI : *CurrBlock) {
2465
33.7k
      switch (BI.getKind()) {
2466
33.4k
        case CFGElement::Statement: {
2467
33.4k
          CFGStmt CS = BI.castAs<CFGStmt>();
2468
33.4k
          LocksetBuilder.Visit(CS.getStmt());
2469
33.4k
          break;
2470
0
        }
2471
0
        // Ignore BaseDtor, MemberDtor, and TemporaryDtor for now.
2472
256
        case CFGElement::AutomaticObjectDtor: {
2473
256
          CFGAutomaticObjDtor AD = BI.castAs<CFGAutomaticObjDtor>();
2474
256
          const auto *DD = AD.getDestructorDecl(AC.getASTContext());
2475
256
          if (!DD->hasAttrs())
2476
37
            break;
2477
219
2478
219
          // Create a dummy expression,
2479
219
          auto *VD = const_cast<VarDecl *>(AD.getVarDecl());
2480
219
          DeclRefExpr DRE(VD->getASTContext(), VD, false,
2481
219
                          VD->getType().getNonReferenceType(), VK_LValue,
2482
219
                          AD.getTriggerStmt()->getEndLoc());
2483
219
          LocksetBuilder.handleCall(&DRE, DD);
2484
219
          break;
2485
219
        }
2486
219
        default:
2487
26
          break;
2488
33.7k
      }
2489
33.7k
    }
2490
7.27k
    CurrBlockInfo->ExitSet = LocksetBuilder.FSet;
2491
7.27k
2492
7.27k
    // For every back edge from CurrBlock (the end of the loop) to another block
2493
7.27k
    // (FirstLoopBlock) we need to check that the Lockset of Block is equal to
2494
7.27k
    // the one held at the beginning of FirstLoopBlock. We can look up the
2495
7.27k
    // Lockset held at the beginning of FirstLoopBlock in the EntryLockSets map.
2496
7.27k
    for (CFGBlock::const_succ_iterator SI = CurrBlock->succ_begin(),
2497
13.2k
         SE  = CurrBlock->succ_end(); SI != SE; 
++SI5.98k
) {
2498
5.98k
      // if CurrBlock -> *SI is *not* a back edge
2499
5.98k
      if (*SI == nullptr || 
!VisitedBlocks.alreadySet(*SI)5.98k
)
2500
5.88k
        continue;
2501
98
2502
98
      CFGBlock *FirstLoopBlock = *SI;
2503
98
      CFGBlockInfo *PreLoop = &BlockInfo[FirstLoopBlock->getBlockID()];
2504
98
      CFGBlockInfo *LoopEnd = &BlockInfo[CurrBlockID];
2505
98
      intersectAndWarn(LoopEnd->ExitSet, PreLoop->EntrySet,
2506
98
                       PreLoop->EntryLoc,
2507
98
                       LEK_LockedSomeLoopIterations,
2508
98
                       false);
2509
98
    }
2510
7.27k
  }
2511
1.98k
2512
1.98k
  CFGBlockInfo *Initial = &BlockInfo[CFGraph->getEntry().getBlockID()];
2513
1.98k
  CFGBlockInfo *Final   = &BlockInfo[CFGraph->getExit().getBlockID()];
2514
1.98k
2515
1.98k
  // Skip the final check if the exit block is unreachable.
2516
1.98k
  if (!Final->Reachable)
2517
20
    return;
2518
1.96k
2519
1.96k
  // By default, we expect all locks held on entry to be held on exit.
2520
1.96k
  FactSet ExpectedExitSet = Initial->EntrySet;
2521
1.96k
2522
1.96k
  // Adjust the expected exit set by adding or removing locks, as declared
2523
1.96k
  // by *-LOCK_FUNCTION and UNLOCK_FUNCTION.  The intersect below will then
2524
1.96k
  // issue the appropriate warning.
2525
1.96k
  // FIXME: the location here is not quite right.
2526
1.96k
  for (const auto &Lock : ExclusiveLocksAcquired)
2527
52
    ExpectedExitSet.addLock(FactMan, std::make_unique<LockableFactEntry>(
2528
52
                                         Lock, LK_Exclusive, D->getLocation()));
2529
1.96k
  for (const auto &Lock : SharedLocksAcquired)
2530
24
    ExpectedExitSet.addLock(FactMan, std::make_unique<LockableFactEntry>(
2531
24
                                         Lock, LK_Shared, D->getLocation()));
2532
1.96k
  for (const auto &Lock : LocksReleased)
2533
69
    ExpectedExitSet.removeLock(FactMan, Lock);
2534
1.96k
2535
1.96k
  // FIXME: Should we call this function for all blocks which exit the function?
2536
1.96k
  intersectAndWarn(ExpectedExitSet, Final->ExitSet,
2537
1.96k
                   Final->ExitLoc,
2538
1.96k
                   LEK_LockedAtEndOfFunction,
2539
1.96k
                   LEK_NotLockedAtEndOfFunction,
2540
1.96k
                   false);
2541
1.96k
2542
1.96k
  Handler.leaveFunction(CurrentFunction);
2543
1.96k
}
2544
2545
/// Check a function's CFG for thread-safety violations.
2546
///
2547
/// We traverse the blocks in the CFG, compute the set of mutexes that are held
2548
/// at the end of each block, and issue warnings for thread safety violations.
2549
/// Each block in the CFG is traversed exactly once.
2550
void threadSafety::runThreadSafetyAnalysis(AnalysisDeclContext &AC,
2551
                                           ThreadSafetyHandler &Handler,
2552
2.14k
                                           BeforeSet **BSet) {
2553
2.14k
  if (!*BSet)
2554
34
    *BSet = new BeforeSet;
2555
2.14k
  ThreadSafetyAnalyzer Analyzer(Handler, *BSet);
2556
2.14k
  Analyzer.runAnalysis(AC);
2557
2.14k
}
2558
2559
50.2k
void threadSafety::threadSafetyCleanup(BeforeSet *Cache) { delete Cache; }
2560
2561
/// Helper function that returns a LockKind required for the given level
2562
/// of access.
2563
2.97k
LockKind threadSafety::getLockKindFromAccessKind(AccessKind AK) {
2564
2.97k
  switch (AK) {
2565
1.20k
    case AK_Read :
2566
1.20k
      return LK_Shared;
2567
1.76k
    case AK_Written :
2568
1.76k
      return LK_Exclusive;
2569
0
  }
2570
0
  llvm_unreachable("Unknown AccessKind");
2571
0
}