aboutsummaryrefslogtreecommitdiffstats
path: root/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
blob: 8236907ea773b799f1172599980b0569c1b236ba (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
//===--- AnalysisConsumer.cpp - ASTConsumer for running Analyses ----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// "Meta" ASTConsumer for running different source analyses.
//
//===----------------------------------------------------------------------===//

#include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"
#include "ModelInjector.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Analysis/Analyses/LiveVariables.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/CallGraph.h"
#include "clang/Analysis/CodeInjector.h"
#include "clang/Basic/SourceManager.h"
#include "clang/CrossTU/CrossTranslationUnit.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/StaticAnalyzer/Checkers/LocalCheckers.h"
#include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathDiagnosticConsumers.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "clang/StaticAnalyzer/Frontend/CheckerRegistration.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include <memory>
#include <queue>
#include <utility>

using namespace clang;
using namespace ento;

#define DEBUG_TYPE "AnalysisConsumer"

STATISTIC(NumFunctionTopLevel, "The # of functions at top level.");
STATISTIC(NumFunctionsAnalyzed,
                      "The # of functions and blocks analyzed (as top level "
                      "with inlining turned on).");
STATISTIC(NumBlocksInAnalyzedFunctions,
                      "The # of basic blocks in the analyzed functions.");
STATISTIC(NumVisitedBlocksInAnalyzedFunctions,
          "The # of visited basic blocks in the analyzed functions.");
STATISTIC(PercentReachableBlocks, "The % of reachable basic blocks.");
STATISTIC(MaxCFGSize, "The maximum number of basic blocks in a function.");

//===----------------------------------------------------------------------===//
// Special PathDiagnosticConsumers.
//===----------------------------------------------------------------------===//

void ento::createPlistHTMLDiagnosticConsumer(
    AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
    const std::string &prefix, const Preprocessor &PP,
    const cross_tu::CrossTranslationUnitContext &CTU) {
  createHTMLDiagnosticConsumer(AnalyzerOpts, C,
                               llvm::sys::path::parent_path(prefix), PP, CTU);
  createPlistMultiFileDiagnosticConsumer(AnalyzerOpts, C, prefix, PP, CTU);
}

void ento::createTextPathDiagnosticConsumer(
    AnalyzerOptions &AnalyzerOpts, PathDiagnosticConsumers &C,
    const std::string &Prefix, const clang::Preprocessor &PP,
    const cross_tu::CrossTranslationUnitContext &CTU) {
  llvm_unreachable("'text' consumer should be enabled on ClangDiags");
}

namespace {
class ClangDiagPathDiagConsumer : public PathDiagnosticConsumer {
  DiagnosticsEngine &Diag;
  bool IncludePath = false, ShouldEmitAsError = false, FixitsAsRemarks = false;

public:
  ClangDiagPathDiagConsumer(DiagnosticsEngine &Diag)
      : Diag(Diag) {}
  ~ClangDiagPathDiagConsumer() override {}
  StringRef getName() const override { return "ClangDiags"; }

  bool supportsLogicalOpControlFlow() const override { return true; }
  bool supportsCrossFileDiagnostics() const override { return true; }

  PathGenerationScheme getGenerationScheme() const override {
    return IncludePath ? Minimal : None;
  }

  void enablePaths() { IncludePath = true; }
  void enableWerror() { ShouldEmitAsError = true; }
  void enableFixitsAsRemarks() { FixitsAsRemarks = true; }

  void FlushDiagnosticsImpl(std::vector<const PathDiagnostic *> &Diags,
                            FilesMade *filesMade) override {
    unsigned WarnID =
        ShouldEmitAsError
            ? Diag.getCustomDiagID(DiagnosticsEngine::Error, "%0")
            : Diag.getCustomDiagID(DiagnosticsEngine::Warning, "%0");
    unsigned NoteID = Diag.getCustomDiagID(DiagnosticsEngine::Note, "%0");
    unsigned RemarkID = Diag.getCustomDiagID(DiagnosticsEngine::Remark, "%0");

    auto reportPiece =
        [&](unsigned ID, SourceLocation Loc, StringRef String,
            ArrayRef<SourceRange> Ranges, ArrayRef<FixItHint> Fixits) {
          if (!FixitsAsRemarks) {
            Diag.Report(Loc, ID) << String << Ranges << Fixits;
          } else {
            Diag.Report(Loc, ID) << String << Ranges;
            for (const FixItHint &Hint : Fixits) {
              SourceManager &SM = Diag.getSourceManager();
              llvm::SmallString<128> Str;
              llvm::raw_svector_ostream OS(Str);
              // FIXME: Add support for InsertFromRange and
              // BeforePreviousInsertion.
              assert(!Hint.InsertFromRange.isValid() && "Not implemented yet!");
              assert(!Hint.BeforePreviousInsertions && "Not implemented yet!");
              OS << SM.getSpellingColumnNumber(Hint.RemoveRange.getBegin())
                 << "-" << SM.getSpellingColumnNumber(Hint.RemoveRange.getEnd())
                 << ": '" << Hint.CodeToInsert << "'";
              Diag.Report(Loc, RemarkID) << OS.str();
            }
          }
        };

    for (std::vector<const PathDiagnostic *>::iterator I = Diags.begin(),
         E = Diags.end();
         I != E; ++I) {
      const PathDiagnostic *PD = *I;
      reportPiece(WarnID, PD->getLocation().asLocation(),
                  PD->getShortDescription(), PD->path.back()->getRanges(),
                  PD->path.back()->getFixits());

      // First, add extra notes, even if paths should not be included.
      for (const auto &Piece : PD->path) {
        if (!isa<PathDiagnosticNotePiece>(Piece.get()))
          continue;

        reportPiece(NoteID, Piece->getLocation().asLocation(),
                    Piece->getString(), Piece->getRanges(), Piece->getFixits());
      }

      if (!IncludePath)
        continue;

      // Then, add the path notes if necessary.
      PathPieces FlatPath = PD->path.flatten(/*ShouldFlattenMacros=*/true);
      for (const auto &Piece : FlatPath) {
        if (isa<PathDiagnosticNotePiece>(Piece.get()))
          continue;

        reportPiece(NoteID, Piece->getLocation().asLocation(),
                    Piece->getString(), Piece->getRanges(), Piece->getFixits());
      }
    }
  }
};
} // end anonymous namespace

//===----------------------------------------------------------------------===//
// AnalysisConsumer declaration.
//===----------------------------------------------------------------------===//

namespace {

class AnalysisConsumer : public AnalysisASTConsumer,
                         public RecursiveASTVisitor<AnalysisConsumer> {
  enum {
    AM_None = 0,
    AM_Syntax = 0x1,
    AM_Path = 0x2
  };
  typedef unsigned AnalysisMode;

  /// Mode of the analyzes while recursively visiting Decls.
  AnalysisMode RecVisitorMode;
  /// Bug Reporter to use while recursively visiting Decls.
  BugReporter *RecVisitorBR;

  std::vector<std::function<void(CheckerRegistry &)>> CheckerRegistrationFns;

public:
  ASTContext *Ctx;
  const Preprocessor &PP;
  const std::string OutDir;
  AnalyzerOptionsRef Opts;
  ArrayRef<std::string> Plugins;
  CodeInjector *Injector;
  cross_tu::CrossTranslationUnitContext CTU;

  /// Stores the declarations from the local translation unit.
  /// Note, we pre-compute the local declarations at parse time as an
  /// optimization to make sure we do not deserialize everything from disk.
  /// The local declaration to all declarations ratio might be very small when
  /// working with a PCH file.
  SetOfDecls LocalTUDecls;

  // Set of PathDiagnosticConsumers.  Owned by AnalysisManager.
  PathDiagnosticConsumers PathConsumers;

  StoreManagerCreator CreateStoreMgr;
  ConstraintManagerCreator CreateConstraintMgr;

  std::unique_ptr<CheckerManager> checkerMgr;
  std::unique_ptr<AnalysisManager> Mgr;

  /// Time the analyzes time of each translation unit.
  std::unique_ptr<llvm::TimerGroup> AnalyzerTimers;
  std::unique_ptr<llvm::Timer> SyntaxCheckTimer;
  std::unique_ptr<llvm::Timer> ExprEngineTimer;
  std::unique_ptr<llvm::Timer> BugReporterTimer;

  /// The information about analyzed functions shared throughout the
  /// translation unit.
  FunctionSummariesTy FunctionSummaries;

  AnalysisConsumer(CompilerInstance &CI, const std::string &outdir,
                   AnalyzerOptionsRef opts, ArrayRef<std::string> plugins,
                   CodeInjector *injector)
      : RecVisitorMode(0), RecVisitorBR(nullptr), Ctx(nullptr),
        PP(CI.getPreprocessor()), OutDir(outdir), Opts(std::move(opts)),
        Plugins(plugins), Injector(injector), CTU(CI) {
    DigestAnalyzerOptions();
    if (Opts->PrintStats || Opts->ShouldSerializeStats) {
      AnalyzerTimers = std::make_unique<llvm::TimerGroup>(
          "analyzer", "Analyzer timers");
      SyntaxCheckTimer = std::make_unique<llvm::Timer>(
          "syntaxchecks", "Syntax-based analysis time", *AnalyzerTimers);
      ExprEngineTimer = std::make_unique<llvm::Timer>(
          "exprengine", "Path exploration time", *AnalyzerTimers);
      BugReporterTimer = std::make_unique<llvm::Timer>(
          "bugreporter", "Path-sensitive report post-processing time",
          *AnalyzerTimers);
      llvm::EnableStatistics(/* PrintOnExit= */ false);
    }
  }

  ~AnalysisConsumer() override {
    if (Opts->PrintStats) {
      llvm::PrintStatistics();
    }
  }

  void DigestAnalyzerOptions() {
    if (Opts->AnalysisDiagOpt != PD_NONE) {
      // Create the PathDiagnosticConsumer.
      ClangDiagPathDiagConsumer *clangDiags =
          new ClangDiagPathDiagConsumer(PP.getDiagnostics());
      PathConsumers.push_back(clangDiags);

      if (Opts->AnalyzerWerror)
        clangDiags->enableWerror();

      if (Opts->ShouldEmitFixItHintsAsRemarks)
        clangDiags->enableFixitsAsRemarks();

      if (Opts->AnalysisDiagOpt == PD_TEXT) {
        clangDiags->enablePaths();

      } else if (!OutDir.empty()) {
        switch (Opts->AnalysisDiagOpt) {
        default:
#define ANALYSIS_DIAGNOSTICS(NAME, CMDFLAG, DESC, CREATEFN)                    \
  case PD_##NAME:                                                              \
    CREATEFN(*Opts.get(), PathConsumers, OutDir, PP, CTU);                     \
    break;
#include "clang/StaticAnalyzer/Core/Analyses.def"
        }
      }
    }

    // Create the analyzer component creators.
    switch (Opts->AnalysisStoreOpt) {
    default:
      llvm_unreachable("Unknown store manager.");
#define ANALYSIS_STORE(NAME, CMDFLAG, DESC, CREATEFN)           \
      case NAME##Model: CreateStoreMgr = CREATEFN; break;
#include "clang/StaticAnalyzer/Core/Analyses.def"
    }

    switch (Opts->AnalysisConstraintsOpt) {
    default:
      llvm_unreachable("Unknown constraint manager.");
#define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATEFN)     \
      case NAME##Model: CreateConstraintMgr = CREATEFN; break;
#include "clang/StaticAnalyzer/Core/Analyses.def"
    }
  }

  void DisplayFunction(const Decl *D, AnalysisMode Mode,
                       ExprEngine::InliningModes IMode) {
    if (!Opts->AnalyzerDisplayProgress)
      return;

    SourceManager &SM = Mgr->getASTContext().getSourceManager();
    PresumedLoc Loc = SM.getPresumedLoc(D->getLocation());
    if (Loc.isValid()) {
      llvm::errs() << "ANALYZE";

      if (Mode == AM_Syntax)
        llvm::errs() << " (Syntax)";
      else if (Mode == AM_Path) {
        llvm::errs() << " (Path, ";
        switch (IMode) {
          case ExprEngine::Inline_Minimal:
            llvm::errs() << " Inline_Minimal";
            break;
          case ExprEngine::Inline_Regular:
            llvm::errs() << " Inline_Regular";
            break;
        }
        llvm::errs() << ")";
      }
      else
        assert(Mode == (AM_Syntax | AM_Path) && "Unexpected mode!");

      llvm::errs() << ": " << Loc.getFilename() << ' '
                           << getFunctionName(D) << '\n';
    }
  }

  void Initialize(ASTContext &Context) override {
    Ctx = &Context;
    checkerMgr = createCheckerManager(
        *Ctx, *Opts, Plugins, CheckerRegistrationFns, PP.getDiagnostics());

    Mgr = std::make_unique<AnalysisManager>(*Ctx, PathConsumers, CreateStoreMgr,
                                            CreateConstraintMgr,
                                            checkerMgr.get(), *Opts, Injector);
  }

  /// Store the top level decls in the set to be processed later on.
  /// (Doing this pre-processing avoids deserialization of data from PCH.)
  bool HandleTopLevelDecl(DeclGroupRef D) override;
  void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override;

  void HandleTranslationUnit(ASTContext &C) override;

  /// Determine which inlining mode should be used when this function is
  /// analyzed. This allows to redefine the default inlining policies when
  /// analyzing a given function.
  ExprEngine::InliningModes
    getInliningModeForFunction(const Decl *D, const SetOfConstDecls &Visited);

  /// Build the call graph for all the top level decls of this TU and
  /// use it to define the order in which the functions should be visited.
  void HandleDeclsCallGraph(const unsigned LocalTUDeclsSize);

  /// Run analyzes(syntax or path sensitive) on the given function.
  /// \param Mode - determines if we are requesting syntax only or path
  /// sensitive only analysis.
  /// \param VisitedCallees - The output parameter, which is populated with the
  /// set of functions which should be considered analyzed after analyzing the
  /// given root function.
  void HandleCode(Decl *D, AnalysisMode Mode,
                  ExprEngine::InliningModes IMode = ExprEngine::Inline_Minimal,
                  SetOfConstDecls *VisitedCallees = nullptr);

  void RunPathSensitiveChecks(Decl *D,
                              ExprEngine::InliningModes IMode,
                              SetOfConstDecls *VisitedCallees);

  /// Visitors for the RecursiveASTVisitor.
  bool shouldWalkTypesOfTypeLocs() const { return false; }

  /// Handle callbacks for arbitrary Decls.
  bool VisitDecl(Decl *D) {
    AnalysisMode Mode = getModeForDecl(D, RecVisitorMode);
    if (Mode & AM_Syntax) {
      if (SyntaxCheckTimer)
        SyntaxCheckTimer->startTimer();
      checkerMgr->runCheckersOnASTDecl(D, *Mgr, *RecVisitorBR);
      if (SyntaxCheckTimer)
        SyntaxCheckTimer->stopTimer();
    }
    return true;
  }

  bool VisitVarDecl(VarDecl *VD) {
    if (!Opts->IsNaiveCTUEnabled)
      return true;

    if (VD->hasExternalStorage() || VD->isStaticDataMember()) {
      if (!cross_tu::containsConst(VD, *Ctx))
        return true;
    } else {
      // Cannot be initialized in another TU.
      return true;
    }

    if (VD->getAnyInitializer())
      return true;

    llvm::Expected<const VarDecl *> CTUDeclOrError =
      CTU.getCrossTUDefinition(VD, Opts->CTUDir, Opts->CTUIndexName,
                               Opts->DisplayCTUProgress);

    if (!CTUDeclOrError) {
      handleAllErrors(CTUDeclOrError.takeError(),
                      [&](const cross_tu::IndexError &IE) {
                        CTU.emitCrossTUDiagnostics(IE);
                      });
    }

    return true;
  }

  bool VisitFunctionDecl(FunctionDecl *FD) {
    IdentifierInfo *II = FD->getIdentifier();
    if (II && II->getName().startswith("__inline"))
      return true;

    // We skip function template definitions, as their semantics is
    // only determined when they are instantiated.
    if (FD->isThisDeclarationADefinition() &&
        !FD->isDependentContext()) {
      assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
      HandleCode(FD, RecVisitorMode);
    }
    return true;
  }

  bool VisitObjCMethodDecl(ObjCMethodDecl *MD) {
    if (MD->isThisDeclarationADefinition()) {
      assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
      HandleCode(MD, RecVisitorMode);
    }
    return true;
  }

  bool VisitBlockDecl(BlockDecl *BD) {
    if (BD->hasBody()) {
      assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
      // Since we skip function template definitions, we should skip blocks
      // declared in those functions as well.
      if (!BD->isDependentContext()) {
        HandleCode(BD, RecVisitorMode);
      }
    }
    return true;
  }

  void AddDiagnosticConsumer(PathDiagnosticConsumer *Consumer) override {
    PathConsumers.push_back(Consumer);
  }

  void AddCheckerRegistrationFn(std::function<void(CheckerRegistry&)> Fn) override {
    CheckerRegistrationFns.push_back(std::move(Fn));
  }

private:
  void storeTopLevelDecls(DeclGroupRef DG);
  std::string getFunctionName(const Decl *D);

  /// Check if we should skip (not analyze) the given function.
  AnalysisMode getModeForDecl(Decl *D, AnalysisMode Mode);
  void runAnalysisOnTranslationUnit(ASTContext &C);

  /// Print \p S to stderr if \c Opts->AnalyzerDisplayProgress is set.
  void reportAnalyzerProgress(StringRef S);
};
} // end anonymous namespace


//===----------------------------------------------------------------------===//
// AnalysisConsumer implementation.
//===----------------------------------------------------------------------===//
bool AnalysisConsumer::HandleTopLevelDecl(DeclGroupRef DG) {
  storeTopLevelDecls(DG);
  return true;
}

void AnalysisConsumer::HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) {
  storeTopLevelDecls(DG);
}

void AnalysisConsumer::storeTopLevelDecls(DeclGroupRef DG) {
  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) {

    // Skip ObjCMethodDecl, wait for the objc container to avoid
    // analyzing twice.
    if (isa<ObjCMethodDecl>(*I))
      continue;

    LocalTUDecls.push_back(*I);
  }
}

static bool shouldSkipFunction(const Decl *D,
                               const SetOfConstDecls &Visited,
                               const SetOfConstDecls &VisitedAsTopLevel) {
  if (VisitedAsTopLevel.count(D))
    return true;

  // We want to re-analyse the functions as top level in the following cases:
  // - The 'init' methods should be reanalyzed because
  //   ObjCNonNilReturnValueChecker assumes that '[super init]' never returns
  //   'nil' and unless we analyze the 'init' functions as top level, we will
  //   not catch errors within defensive code.
  // - We want to reanalyze all ObjC methods as top level to report Retain
  //   Count naming convention errors more aggressively.
  if (isa<ObjCMethodDecl>(D))
    return false;
  // We also want to reanalyze all C++ copy and move assignment operators to
  // separately check the two cases where 'this' aliases with the parameter and
  // where it may not. (cplusplus.SelfAssignmentChecker)
  if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
    if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())
      return false;
  }

  // Otherwise, if we visited the function before, do not reanalyze it.
  return Visited.count(D);
}

ExprEngine::InliningModes
AnalysisConsumer::getInliningModeForFunction(const Decl *D,
                                             const SetOfConstDecls &Visited) {
  // We want to reanalyze all ObjC methods as top level to report Retain
  // Count naming convention errors more aggressively. But we should tune down
  // inlining when reanalyzing an already inlined function.
  if (Visited.count(D) && isa<ObjCMethodDecl>(D)) {
    const ObjCMethodDecl *ObjCM = cast<ObjCMethodDecl>(D);
    if (ObjCM->getMethodFamily() != OMF_init)
      return ExprEngine::Inline_Minimal;
  }

  return ExprEngine::Inline_Regular;
}

void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
  // Build the Call Graph by adding all the top level declarations to the graph.
  // Note: CallGraph can trigger deserialization of more items from a pch
  // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
  // We rely on random access to add the initially processed Decls to CG.
  CallGraph CG;
  for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
    CG.addToCallGraph(LocalTUDecls[i]);
  }

  // Walk over all of the call graph nodes in topological order, so that we
  // analyze parents before the children. Skip the functions inlined into
  // the previously processed functions. Use external Visited set to identify
  // inlined functions. The topological order allows the "do not reanalyze
  // previously inlined function" performance heuristic to be triggered more
  // often.
  SetOfConstDecls Visited;
  SetOfConstDecls VisitedAsTopLevel;
  llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
  for (llvm::ReversePostOrderTraversal<clang::CallGraph*>::rpo_iterator
         I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
    NumFunctionTopLevel++;

    CallGraphNode *N = *I;
    Decl *D = N->getDecl();

    // Skip the abstract root node.
    if (!D)
      continue;

    // Skip the functions which have been processed already or previously
    // inlined.
    if (shouldSkipFunction(D, Visited, VisitedAsTopLevel))
      continue;

    // Analyze the function.
    SetOfConstDecls VisitedCallees;

    HandleCode(D, AM_Path, getInliningModeForFunction(D, Visited),
               (Mgr->options.InliningMode == All ? nullptr : &VisitedCallees));

    // Add the visited callees to the global visited set.
    for (const Decl *Callee : VisitedCallees)
      // Decls from CallGraph are already canonical. But Decls coming from
      // CallExprs may be not. We should canonicalize them manually.
      Visited.insert(isa<ObjCMethodDecl>(Callee) ? Callee
                                                 : Callee->getCanonicalDecl());
    VisitedAsTopLevel.insert(D);
  }
}

static bool isBisonFile(ASTContext &C) {
  const SourceManager &SM = C.getSourceManager();
  FileID FID = SM.getMainFileID();
  StringRef Buffer = SM.getBuffer(FID)->getBuffer();
  if (Buffer.startswith("/* A Bison parser, made by"))
    return true;
  return false;
}

void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
  BugReporter BR(*Mgr);
  TranslationUnitDecl *TU = C.getTranslationUnitDecl();
  if (SyntaxCheckTimer)
    SyntaxCheckTimer->startTimer();
  checkerMgr->runCheckersOnASTDecl(TU, *Mgr, BR);
  if (SyntaxCheckTimer)
    SyntaxCheckTimer->stopTimer();

  // Run the AST-only checks using the order in which functions are defined.
  // If inlining is not turned on, use the simplest function order for path
  // sensitive analyzes as well.
  RecVisitorMode = AM_Syntax;
  if (!Mgr->shouldInlineCall())
    RecVisitorMode |= AM_Path;
  RecVisitorBR = &BR;

  // Process all the top level declarations.
  //
  // Note: TraverseDecl may modify LocalTUDecls, but only by appending more
  // entries.  Thus we don't use an iterator, but rely on LocalTUDecls
  // random access.  By doing so, we automatically compensate for iterators
  // possibly being invalidated, although this is a bit slower.
  const unsigned LocalTUDeclsSize = LocalTUDecls.size();
  for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
    TraverseDecl(LocalTUDecls[i]);
  }

  if (Mgr->shouldInlineCall())
    HandleDeclsCallGraph(LocalTUDeclsSize);

  // After all decls handled, run checkers on the entire TranslationUnit.
  checkerMgr->runCheckersOnEndOfTranslationUnit(TU, *Mgr, BR);

  BR.FlushReports();
  RecVisitorBR = nullptr;
}

void AnalysisConsumer::reportAnalyzerProgress(StringRef S) {
  if (Opts->AnalyzerDisplayProgress)
    llvm::errs() << S;
}

void AnalysisConsumer::HandleTranslationUnit(ASTContext &C) {

  // Don't run the actions if an error has occurred with parsing the file.
  DiagnosticsEngine &Diags = PP.getDiagnostics();
  if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
    return;

  if (isBisonFile(C)) {
    reportAnalyzerProgress("Skipping bison-generated file\n");
  } else if (Opts->DisableAllCheckers) {

    // Don't analyze if the user explicitly asked for no checks to be performed
    // on this file.
    reportAnalyzerProgress("All checks are disabled using a supplied option\n");
  } else {
    // Otherwise, just run the analysis.
    runAnalysisOnTranslationUnit(C);
  }

  // Count how many basic blocks we have not covered.
  NumBlocksInAnalyzedFunctions = FunctionSummaries.getTotalNumBasicBlocks();
  NumVisitedBlocksInAnalyzedFunctions =
      FunctionSummaries.getTotalNumVisitedBasicBlocks();
  if (NumBlocksInAnalyzedFunctions > 0)
    PercentReachableBlocks =
      (FunctionSummaries.getTotalNumVisitedBasicBlocks() * 100) /
        NumBlocksInAnalyzedFunctions;

  // Explicitly destroy the PathDiagnosticConsumer.  This will flush its output.
  // FIXME: This should be replaced with something that doesn't rely on
  // side-effects in PathDiagnosticConsumer's destructor. This is required when
  // used with option -disable-free.
  Mgr.reset();
}

std::string AnalysisConsumer::getFunctionName(const Decl *D) {
  std::string Str;
  llvm::raw_string_ostream OS(Str);

  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
    OS << FD->getQualifiedNameAsString();

    // In C++, there are overloads.
    if (Ctx->getLangOpts().CPlusPlus) {
      OS << '(';
      for (const auto &P : FD->parameters()) {
        if (P != *FD->param_begin())
          OS << ", ";
        OS << P->getType().getAsString();
      }
      OS << ')';
    }

  } else if (isa<BlockDecl>(D)) {
    PresumedLoc Loc = Ctx->getSourceManager().getPresumedLoc(D->getLocation());

    if (Loc.isValid()) {
      OS << "block (line: " << Loc.getLine() << ", col: " << Loc.getColumn()
         << ')';
    }

  } else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) {

    // FIXME: copy-pasted from CGDebugInfo.cpp.
    OS << (OMD->isInstanceMethod() ? '-' : '+') << '[';
    const DeclContext *DC = OMD->getDeclContext();
    if (const auto *OID = dyn_cast<ObjCImplementationDecl>(DC)) {
      OS << OID->getName();
    } else if (const auto *OID = dyn_cast<ObjCInterfaceDecl>(DC)) {
      OS << OID->getName();
    } else if (const auto *OC = dyn_cast<ObjCCategoryDecl>(DC)) {
      if (OC->IsClassExtension()) {
        OS << OC->getClassInterface()->getName();
      } else {
        OS << OC->getIdentifier()->getNameStart() << '('
           << OC->getIdentifier()->getNameStart() << ')';
      }
    } else if (const auto *OCD = dyn_cast<ObjCCategoryImplDecl>(DC)) {
      OS << OCD->getClassInterface()->getName() << '('
         << OCD->getName() << ')';
    } else if (isa<ObjCProtocolDecl>(DC)) {
      // We can extract the type of the class from the self pointer.
      if (ImplicitParamDecl *SelfDecl = OMD->getSelfDecl()) {
        QualType ClassTy =
            cast<ObjCObjectPointerType>(SelfDecl->getType())->getPointeeType();
        ClassTy.print(OS, PrintingPolicy(LangOptions()));
      }
    }
    OS << ' ' << OMD->getSelector().getAsString() << ']';

  }

  return OS.str();
}

AnalysisConsumer::AnalysisMode
AnalysisConsumer::getModeForDecl(Decl *D, AnalysisMode Mode) {
  if (!Opts->AnalyzeSpecificFunction.empty() &&
      getFunctionName(D) != Opts->AnalyzeSpecificFunction)
    return AM_None;

  // Unless -analyze-all is specified, treat decls differently depending on
  // where they came from:
  // - Main source file: run both path-sensitive and non-path-sensitive checks.
  // - Header files: run non-path-sensitive checks only.
  // - System headers: don't run any checks.
  SourceManager &SM = Ctx->getSourceManager();
  const Stmt *Body = D->getBody();
  SourceLocation SL = Body ? Body->getBeginLoc() : D->getLocation();
  SL = SM.getExpansionLoc(SL);

  if (!Opts->AnalyzeAll && !Mgr->isInCodeFile(SL)) {
    if (SL.isInvalid() || SM.isInSystemHeader(SL))
      return AM_None;
    return Mode & ~AM_Path;
  }

  return Mode;
}

void AnalysisConsumer::HandleCode(Decl *D, AnalysisMode Mode,
                                  ExprEngine::InliningModes IMode,
                                  SetOfConstDecls *VisitedCallees) {
  if (!D->hasBody())
    return;
  Mode = getModeForDecl(D, Mode);
  if (Mode == AM_None)
    return;

  // Clear the AnalysisManager of old AnalysisDeclContexts.
  Mgr->ClearContexts();
  // Ignore autosynthesized code.
  if (Mgr->getAnalysisDeclContext(D)->isBodyAutosynthesized())
    return;

  DisplayFunction(D, Mode, IMode);
  CFG *DeclCFG = Mgr->getCFG(D);
  if (DeclCFG)
    MaxCFGSize.updateMax(DeclCFG->size());

  BugReporter BR(*Mgr);

  if (Mode & AM_Syntax) {
    if (SyntaxCheckTimer)
      SyntaxCheckTimer->startTimer();
    checkerMgr->runCheckersOnASTBody(D, *Mgr, BR);
    if (SyntaxCheckTimer)
      SyntaxCheckTimer->stopTimer();
  }

  BR.FlushReports();

  if ((Mode & AM_Path) && checkerMgr->hasPathSensitiveCheckers()) {
    RunPathSensitiveChecks(D, IMode, VisitedCallees);
    if (IMode != ExprEngine::Inline_Minimal)
      NumFunctionsAnalyzed++;
  }
}

//===----------------------------------------------------------------------===//
// Path-sensitive checking.
//===----------------------------------------------------------------------===//

void AnalysisConsumer::RunPathSensitiveChecks(Decl *D,
                                              ExprEngine::InliningModes IMode,
                                              SetOfConstDecls *VisitedCallees) {
  // Construct the analysis engine.  First check if the CFG is valid.
  // FIXME: Inter-procedural analysis will need to handle invalid CFGs.
  if (!Mgr->getCFG(D))
    return;

  // See if the LiveVariables analysis scales.
  if (!Mgr->getAnalysisDeclContext(D)->getAnalysis<RelaxedLiveVariables>())
    return;

  ExprEngine Eng(CTU, *Mgr, VisitedCallees, &FunctionSummaries, IMode);

  // Execute the worklist algorithm.
  if (ExprEngineTimer)
    ExprEngineTimer->startTimer();
  Eng.ExecuteWorkList(Mgr->getAnalysisDeclContextManager().getStackFrame(D),
                      Mgr->options.MaxNodesPerTopLevelFunction);
  if (ExprEngineTimer)
    ExprEngineTimer->stopTimer();

  if (!Mgr->options.DumpExplodedGraphTo.empty())
    Eng.DumpGraph(Mgr->options.TrimGraph, Mgr->options.DumpExplodedGraphTo);

  // Visualize the exploded graph.
  if (Mgr->options.visualizeExplodedGraphWithGraphViz)
    Eng.ViewGraph(Mgr->options.TrimGraph);

  // Display warnings.
  if (BugReporterTimer)
    BugReporterTimer->startTimer();
  Eng.getBugReporter().FlushReports();
  if (BugReporterTimer)
    BugReporterTimer->stopTimer();
}

//===----------------------------------------------------------------------===//
// AnalysisConsumer creation.
//===----------------------------------------------------------------------===//

std::unique_ptr<AnalysisASTConsumer>
ento::CreateAnalysisConsumer(CompilerInstance &CI) {
  // Disable the effects of '-Werror' when using the AnalysisConsumer.
  CI.getPreprocessor().getDiagnostics().setWarningsAsErrors(false);

  AnalyzerOptionsRef analyzerOpts = CI.getAnalyzerOpts();
  bool hasModelPath = analyzerOpts->Config.count("model-path") > 0;

  return std::make_unique<AnalysisConsumer>(
      CI, CI.getFrontendOpts().OutputFile, analyzerOpts,
      CI.getFrontendOpts().Plugins,
      hasModelPath ? new ModelInjector(CI) : nullptr);
}