1 //===--- AnalysisConsumer.cpp - ASTConsumer for running Analyses ----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // "Meta" ASTConsumer for running different source analyses.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"
15 #include "ModelInjector.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/RecursiveASTVisitor.h"
20 #include "clang/Analysis/Analyses/LiveVariables.h"
21 #include "clang/Analysis/CFG.h"
22 #include "clang/Analysis/CallGraph.h"
23 #include "clang/Analysis/CodeInjector.h"
24 #include "clang/Basic/SourceManager.h"
25 #include "clang/Frontend/CompilerInstance.h"
26 #include "clang/Lex/Preprocessor.h"
27 #include "clang/StaticAnalyzer/Checkers/LocalCheckers.h"
28 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
29 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
30 #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
31 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
32 #include "clang/StaticAnalyzer/Core/PathDiagnosticConsumers.h"
33 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
34 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
35 #include "clang/StaticAnalyzer/Frontend/CheckerRegistration.h"
36 #include "llvm/ADT/PostOrderIterator.h"
37 #include "llvm/ADT/Statistic.h"
38 #include "llvm/Support/FileSystem.h"
39 #include "llvm/Support/Path.h"
40 #include "llvm/Support/Program.h"
41 #include "llvm/Support/Timer.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include <memory>
44 #include <queue>
45 #include <utility>
46 
47 using namespace clang;
48 using namespace ento;
49 
50 #define DEBUG_TYPE "AnalysisConsumer"
51 
52 static std::unique_ptr<ExplodedNode::Auditor> CreateUbiViz();
53 
54 STATISTIC(NumFunctionTopLevel, "The # of functions at top level.");
55 STATISTIC(NumFunctionsAnalyzed,
56                       "The # of functions and blocks analyzed (as top level "
57                       "with inlining turned on).");
58 STATISTIC(NumBlocksInAnalyzedFunctions,
59                       "The # of basic blocks in the analyzed functions.");
60 STATISTIC(PercentReachableBlocks, "The % of reachable basic blocks.");
61 STATISTIC(MaxCFGSize, "The maximum number of basic blocks in a function.");
62 
63 //===----------------------------------------------------------------------===//
64 // Special PathDiagnosticConsumers.
65 //===----------------------------------------------------------------------===//
66 
67 void ento::createPlistHTMLDiagnosticConsumer(AnalyzerOptions &AnalyzerOpts,
68                                              PathDiagnosticConsumers &C,
69                                              const std::string &prefix,
70                                              const Preprocessor &PP) {
71   createHTMLDiagnosticConsumer(AnalyzerOpts, C,
72                                llvm::sys::path::parent_path(prefix), PP);
73   createPlistDiagnosticConsumer(AnalyzerOpts, C, prefix, PP);
74 }
75 
76 void ento::createTextPathDiagnosticConsumer(AnalyzerOptions &AnalyzerOpts,
77                                             PathDiagnosticConsumers &C,
78                                             const std::string &Prefix,
79                                             const clang::Preprocessor &PP) {
80   llvm_unreachable("'text' consumer should be enabled on ClangDiags");
81 }
82 
83 namespace {
84 class ClangDiagPathDiagConsumer : public PathDiagnosticConsumer {
85   DiagnosticsEngine &Diag;
86   bool IncludePath;
87 public:
88   ClangDiagPathDiagConsumer(DiagnosticsEngine &Diag)
89     : Diag(Diag), IncludePath(false) {}
90   ~ClangDiagPathDiagConsumer() override {}
91   StringRef getName() const override { return "ClangDiags"; }
92 
93   bool supportsLogicalOpControlFlow() const override { return true; }
94   bool supportsCrossFileDiagnostics() const override { return true; }
95 
96   PathGenerationScheme getGenerationScheme() const override {
97     return IncludePath ? Minimal : None;
98   }
99 
100   void enablePaths() {
101     IncludePath = true;
102   }
103 
104   void FlushDiagnosticsImpl(std::vector<const PathDiagnostic *> &Diags,
105                             FilesMade *filesMade) override {
106     unsigned WarnID = Diag.getCustomDiagID(DiagnosticsEngine::Warning, "%0");
107     unsigned NoteID = Diag.getCustomDiagID(DiagnosticsEngine::Note, "%0");
108 
109     for (std::vector<const PathDiagnostic*>::iterator I = Diags.begin(),
110          E = Diags.end(); I != E; ++I) {
111       const PathDiagnostic *PD = *I;
112       SourceLocation WarnLoc = PD->getLocation().asLocation();
113       Diag.Report(WarnLoc, WarnID) << PD->getShortDescription()
114                                    << PD->path.back()->getRanges();
115 
116       if (!IncludePath)
117         continue;
118 
119       PathPieces FlatPath = PD->path.flatten(/*ShouldFlattenMacros=*/true);
120       for (PathPieces::const_iterator PI = FlatPath.begin(),
121                                       PE = FlatPath.end();
122            PI != PE; ++PI) {
123         SourceLocation NoteLoc = (*PI)->getLocation().asLocation();
124         Diag.Report(NoteLoc, NoteID) << (*PI)->getString()
125                                      << (*PI)->getRanges();
126       }
127     }
128   }
129 };
130 } // end anonymous namespace
131 
132 //===----------------------------------------------------------------------===//
133 // AnalysisConsumer declaration.
134 //===----------------------------------------------------------------------===//
135 
136 namespace {
137 
138 class AnalysisConsumer : public AnalysisASTConsumer,
139                          public RecursiveASTVisitor<AnalysisConsumer> {
140   enum {
141     AM_None = 0,
142     AM_Syntax = 0x1,
143     AM_Path = 0x2
144   };
145   typedef unsigned AnalysisMode;
146 
147   /// Mode of the analyzes while recursively visiting Decls.
148   AnalysisMode RecVisitorMode;
149   /// Bug Reporter to use while recursively visiting Decls.
150   BugReporter *RecVisitorBR;
151 
152 public:
153   ASTContext *Ctx;
154   const Preprocessor &PP;
155   const std::string OutDir;
156   AnalyzerOptionsRef Opts;
157   ArrayRef<std::string> Plugins;
158   CodeInjector *Injector;
159 
160   /// \brief Stores the declarations from the local translation unit.
161   /// Note, we pre-compute the local declarations at parse time as an
162   /// optimization to make sure we do not deserialize everything from disk.
163   /// The local declaration to all declarations ratio might be very small when
164   /// working with a PCH file.
165   SetOfDecls LocalTUDecls;
166 
167   // Set of PathDiagnosticConsumers.  Owned by AnalysisManager.
168   PathDiagnosticConsumers PathConsumers;
169 
170   StoreManagerCreator CreateStoreMgr;
171   ConstraintManagerCreator CreateConstraintMgr;
172 
173   std::unique_ptr<CheckerManager> checkerMgr;
174   std::unique_ptr<AnalysisManager> Mgr;
175 
176   /// Time the analyzes time of each translation unit.
177   static llvm::Timer* TUTotalTimer;
178 
179   /// The information about analyzed functions shared throughout the
180   /// translation unit.
181   FunctionSummariesTy FunctionSummaries;
182 
183   AnalysisConsumer(const Preprocessor &pp, const std::string &outdir,
184                    AnalyzerOptionsRef opts, ArrayRef<std::string> plugins,
185                    CodeInjector *injector)
186       : RecVisitorMode(0), RecVisitorBR(nullptr), Ctx(nullptr), PP(pp),
187         OutDir(outdir), Opts(std::move(opts)), Plugins(plugins),
188         Injector(injector) {
189     DigestAnalyzerOptions();
190     if (Opts->PrintStats) {
191       llvm::EnableStatistics();
192       TUTotalTimer = new llvm::Timer("Analyzer Total Time");
193     }
194   }
195 
196   ~AnalysisConsumer() override {
197     if (Opts->PrintStats) {
198       delete TUTotalTimer;
199       llvm::PrintStatistics();
200     }
201   }
202 
203   void DigestAnalyzerOptions() {
204     if (Opts->AnalysisDiagOpt != PD_NONE) {
205       // Create the PathDiagnosticConsumer.
206       ClangDiagPathDiagConsumer *clangDiags =
207           new ClangDiagPathDiagConsumer(PP.getDiagnostics());
208       PathConsumers.push_back(clangDiags);
209 
210       if (Opts->AnalysisDiagOpt == PD_TEXT) {
211         clangDiags->enablePaths();
212 
213       } else if (!OutDir.empty()) {
214         switch (Opts->AnalysisDiagOpt) {
215         default:
216 #define ANALYSIS_DIAGNOSTICS(NAME, CMDFLAG, DESC, CREATEFN)                    \
217   case PD_##NAME:                                                              \
218     CREATEFN(*Opts.get(), PathConsumers, OutDir, PP);                       \
219     break;
220 #include "clang/StaticAnalyzer/Core/Analyses.def"
221         }
222       }
223     }
224 
225     // Create the analyzer component creators.
226     switch (Opts->AnalysisStoreOpt) {
227     default:
228       llvm_unreachable("Unknown store manager.");
229 #define ANALYSIS_STORE(NAME, CMDFLAG, DESC, CREATEFN)           \
230       case NAME##Model: CreateStoreMgr = CREATEFN; break;
231 #include "clang/StaticAnalyzer/Core/Analyses.def"
232     }
233 
234     switch (Opts->AnalysisConstraintsOpt) {
235     default:
236       llvm_unreachable("Unknown constraint manager.");
237 #define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATEFN)     \
238       case NAME##Model: CreateConstraintMgr = CREATEFN; break;
239 #include "clang/StaticAnalyzer/Core/Analyses.def"
240     }
241   }
242 
243   void DisplayFunction(const Decl *D, AnalysisMode Mode,
244                        ExprEngine::InliningModes IMode) {
245     if (!Opts->AnalyzerDisplayProgress)
246       return;
247 
248     SourceManager &SM = Mgr->getASTContext().getSourceManager();
249     PresumedLoc Loc = SM.getPresumedLoc(D->getLocation());
250     if (Loc.isValid()) {
251       llvm::errs() << "ANALYZE";
252 
253       if (Mode == AM_Syntax)
254         llvm::errs() << " (Syntax)";
255       else if (Mode == AM_Path) {
256         llvm::errs() << " (Path, ";
257         switch (IMode) {
258           case ExprEngine::Inline_Minimal:
259             llvm::errs() << " Inline_Minimal";
260             break;
261           case ExprEngine::Inline_Regular:
262             llvm::errs() << " Inline_Regular";
263             break;
264         }
265         llvm::errs() << ")";
266       }
267       else
268         assert(Mode == (AM_Syntax | AM_Path) && "Unexpected mode!");
269 
270       llvm::errs() << ": " << Loc.getFilename() << ' '
271                            << getFunctionName(D) << '\n';
272     }
273   }
274 
275   void Initialize(ASTContext &Context) override {
276     Ctx = &Context;
277     checkerMgr = createCheckerManager(*Opts, PP.getLangOpts(), Plugins,
278                                       PP.getDiagnostics());
279 
280     Mgr = llvm::make_unique<AnalysisManager>(
281         *Ctx, PP.getDiagnostics(), PP.getLangOpts(), PathConsumers,
282         CreateStoreMgr, CreateConstraintMgr, checkerMgr.get(), *Opts, Injector);
283   }
284 
285   /// \brief Store the top level decls in the set to be processed later on.
286   /// (Doing this pre-processing avoids deserialization of data from PCH.)
287   bool HandleTopLevelDecl(DeclGroupRef D) override;
288   void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override;
289 
290   void HandleTranslationUnit(ASTContext &C) override;
291 
292   /// \brief Determine which inlining mode should be used when this function is
293   /// analyzed. This allows to redefine the default inlining policies when
294   /// analyzing a given function.
295   ExprEngine::InliningModes
296     getInliningModeForFunction(const Decl *D, const SetOfConstDecls &Visited);
297 
298   /// \brief Build the call graph for all the top level decls of this TU and
299   /// use it to define the order in which the functions should be visited.
300   void HandleDeclsCallGraph(const unsigned LocalTUDeclsSize);
301 
302   /// \brief Run analyzes(syntax or path sensitive) on the given function.
303   /// \param Mode - determines if we are requesting syntax only or path
304   /// sensitive only analysis.
305   /// \param VisitedCallees - The output parameter, which is populated with the
306   /// set of functions which should be considered analyzed after analyzing the
307   /// given root function.
308   void HandleCode(Decl *D, AnalysisMode Mode,
309                   ExprEngine::InliningModes IMode = ExprEngine::Inline_Minimal,
310                   SetOfConstDecls *VisitedCallees = nullptr);
311 
312   void RunPathSensitiveChecks(Decl *D,
313                               ExprEngine::InliningModes IMode,
314                               SetOfConstDecls *VisitedCallees);
315   void ActionExprEngine(Decl *D, bool ObjCGCEnabled,
316                         ExprEngine::InliningModes IMode,
317                         SetOfConstDecls *VisitedCallees);
318 
319   /// Visitors for the RecursiveASTVisitor.
320   bool shouldWalkTypesOfTypeLocs() const { return false; }
321 
322   /// Handle callbacks for arbitrary Decls.
323   bool VisitDecl(Decl *D) {
324     AnalysisMode Mode = getModeForDecl(D, RecVisitorMode);
325     if (Mode & AM_Syntax)
326       checkerMgr->runCheckersOnASTDecl(D, *Mgr, *RecVisitorBR);
327     return true;
328   }
329 
330   bool VisitFunctionDecl(FunctionDecl *FD) {
331     IdentifierInfo *II = FD->getIdentifier();
332     if (II && II->getName().startswith("__inline"))
333       return true;
334 
335     // We skip function template definitions, as their semantics is
336     // only determined when they are instantiated.
337     if (FD->isThisDeclarationADefinition() &&
338         !FD->isDependentContext()) {
339       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
340       HandleCode(FD, RecVisitorMode);
341     }
342     return true;
343   }
344 
345   bool VisitObjCMethodDecl(ObjCMethodDecl *MD) {
346     if (MD->isThisDeclarationADefinition()) {
347       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
348       HandleCode(MD, RecVisitorMode);
349     }
350     return true;
351   }
352 
353   bool VisitBlockDecl(BlockDecl *BD) {
354     if (BD->hasBody()) {
355       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
356       // Since we skip function template definitions, we should skip blocks
357       // declared in those functions as well.
358       if (!BD->isDependentContext()) {
359         HandleCode(BD, RecVisitorMode);
360       }
361     }
362     return true;
363   }
364 
365   void AddDiagnosticConsumer(PathDiagnosticConsumer *Consumer) override {
366     PathConsumers.push_back(Consumer);
367   }
368 
369 private:
370   void storeTopLevelDecls(DeclGroupRef DG);
371   std::string getFunctionName(const Decl *D);
372 
373   /// \brief Check if we should skip (not analyze) the given function.
374   AnalysisMode getModeForDecl(Decl *D, AnalysisMode Mode);
375 
376 };
377 } // end anonymous namespace
378 
379 
380 //===----------------------------------------------------------------------===//
381 // AnalysisConsumer implementation.
382 //===----------------------------------------------------------------------===//
383 llvm::Timer* AnalysisConsumer::TUTotalTimer = nullptr;
384 
385 bool AnalysisConsumer::HandleTopLevelDecl(DeclGroupRef DG) {
386   storeTopLevelDecls(DG);
387   return true;
388 }
389 
390 void AnalysisConsumer::HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) {
391   storeTopLevelDecls(DG);
392 }
393 
394 void AnalysisConsumer::storeTopLevelDecls(DeclGroupRef DG) {
395   for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) {
396 
397     // Skip ObjCMethodDecl, wait for the objc container to avoid
398     // analyzing twice.
399     if (isa<ObjCMethodDecl>(*I))
400       continue;
401 
402     LocalTUDecls.push_back(*I);
403   }
404 }
405 
406 static bool shouldSkipFunction(const Decl *D,
407                                const SetOfConstDecls &Visited,
408                                const SetOfConstDecls &VisitedAsTopLevel) {
409   if (VisitedAsTopLevel.count(D))
410     return true;
411 
412   // We want to re-analyse the functions as top level in the following cases:
413   // - The 'init' methods should be reanalyzed because
414   //   ObjCNonNilReturnValueChecker assumes that '[super init]' never returns
415   //   'nil' and unless we analyze the 'init' functions as top level, we will
416   //   not catch errors within defensive code.
417   // - We want to reanalyze all ObjC methods as top level to report Retain
418   //   Count naming convention errors more aggressively.
419   if (isa<ObjCMethodDecl>(D))
420     return false;
421   // We also want to reanalyze all C++ copy and move assignment operators to
422   // separately check the two cases where 'this' aliases with the parameter and
423   // where it may not. (cplusplus.SelfAssignmentChecker)
424   if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
425     if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())
426       return false;
427   }
428 
429   // Otherwise, if we visited the function before, do not reanalyze it.
430   return Visited.count(D);
431 }
432 
433 ExprEngine::InliningModes
434 AnalysisConsumer::getInliningModeForFunction(const Decl *D,
435                                              const SetOfConstDecls &Visited) {
436   // We want to reanalyze all ObjC methods as top level to report Retain
437   // Count naming convention errors more aggressively. But we should tune down
438   // inlining when reanalyzing an already inlined function.
439   if (Visited.count(D) && isa<ObjCMethodDecl>(D)) {
440     const ObjCMethodDecl *ObjCM = cast<ObjCMethodDecl>(D);
441     if (ObjCM->getMethodFamily() != OMF_init)
442       return ExprEngine::Inline_Minimal;
443   }
444 
445   return ExprEngine::Inline_Regular;
446 }
447 
448 void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
449   // Build the Call Graph by adding all the top level declarations to the graph.
450   // Note: CallGraph can trigger deserialization of more items from a pch
451   // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
452   // We rely on random access to add the initially processed Decls to CG.
453   CallGraph CG;
454   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
455     CG.addToCallGraph(LocalTUDecls[i]);
456   }
457 
458   // Walk over all of the call graph nodes in topological order, so that we
459   // analyze parents before the children. Skip the functions inlined into
460   // the previously processed functions. Use external Visited set to identify
461   // inlined functions. The topological order allows the "do not reanalyze
462   // previously inlined function" performance heuristic to be triggered more
463   // often.
464   SetOfConstDecls Visited;
465   SetOfConstDecls VisitedAsTopLevel;
466   llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
467   for (llvm::ReversePostOrderTraversal<clang::CallGraph*>::rpo_iterator
468          I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
469     NumFunctionTopLevel++;
470 
471     CallGraphNode *N = *I;
472     Decl *D = N->getDecl();
473 
474     // Skip the abstract root node.
475     if (!D)
476       continue;
477 
478     // Skip the functions which have been processed already or previously
479     // inlined.
480     if (shouldSkipFunction(D, Visited, VisitedAsTopLevel))
481       continue;
482 
483     // Analyze the function.
484     SetOfConstDecls VisitedCallees;
485 
486     HandleCode(D, AM_Path, getInliningModeForFunction(D, Visited),
487                (Mgr->options.InliningMode == All ? nullptr : &VisitedCallees));
488 
489     // Add the visited callees to the global visited set.
490     for (const Decl *Callee : VisitedCallees)
491       // Decls from CallGraph are already canonical. But Decls coming from
492       // CallExprs may be not. We should canonicalize them manually.
493       Visited.insert(isa<ObjCMethodDecl>(Callee) ? Callee
494                                                  : Callee->getCanonicalDecl());
495     VisitedAsTopLevel.insert(D);
496   }
497 }
498 
499 void AnalysisConsumer::HandleTranslationUnit(ASTContext &C) {
500   // Don't run the actions if an error has occurred with parsing the file.
501   DiagnosticsEngine &Diags = PP.getDiagnostics();
502   if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
503     return;
504 
505   // Don't analyze if the user explicitly asked for no checks to be performed
506   // on this file.
507   if (Opts->DisableAllChecks)
508     return;
509 
510   {
511     if (TUTotalTimer) TUTotalTimer->startTimer();
512 
513     // Introduce a scope to destroy BR before Mgr.
514     BugReporter BR(*Mgr);
515     TranslationUnitDecl *TU = C.getTranslationUnitDecl();
516     checkerMgr->runCheckersOnASTDecl(TU, *Mgr, BR);
517 
518     // Run the AST-only checks using the order in which functions are defined.
519     // If inlining is not turned on, use the simplest function order for path
520     // sensitive analyzes as well.
521     RecVisitorMode = AM_Syntax;
522     if (!Mgr->shouldInlineCall())
523       RecVisitorMode |= AM_Path;
524     RecVisitorBR = &BR;
525 
526     // Process all the top level declarations.
527     //
528     // Note: TraverseDecl may modify LocalTUDecls, but only by appending more
529     // entries.  Thus we don't use an iterator, but rely on LocalTUDecls
530     // random access.  By doing so, we automatically compensate for iterators
531     // possibly being invalidated, although this is a bit slower.
532     const unsigned LocalTUDeclsSize = LocalTUDecls.size();
533     for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
534       TraverseDecl(LocalTUDecls[i]);
535     }
536 
537     if (Mgr->shouldInlineCall())
538       HandleDeclsCallGraph(LocalTUDeclsSize);
539 
540     // After all decls handled, run checkers on the entire TranslationUnit.
541     checkerMgr->runCheckersOnEndOfTranslationUnit(TU, *Mgr, BR);
542 
543     RecVisitorBR = nullptr;
544   }
545 
546   // Explicitly destroy the PathDiagnosticConsumer.  This will flush its output.
547   // FIXME: This should be replaced with something that doesn't rely on
548   // side-effects in PathDiagnosticConsumer's destructor. This is required when
549   // used with option -disable-free.
550   Mgr.reset();
551 
552   if (TUTotalTimer) TUTotalTimer->stopTimer();
553 
554   // Count how many basic blocks we have not covered.
555   NumBlocksInAnalyzedFunctions = FunctionSummaries.getTotalNumBasicBlocks();
556   if (NumBlocksInAnalyzedFunctions > 0)
557     PercentReachableBlocks =
558       (FunctionSummaries.getTotalNumVisitedBasicBlocks() * 100) /
559         NumBlocksInAnalyzedFunctions;
560 
561 }
562 
563 std::string AnalysisConsumer::getFunctionName(const Decl *D) {
564   std::string Str;
565   llvm::raw_string_ostream OS(Str);
566 
567   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
568     OS << FD->getQualifiedNameAsString();
569 
570     // In C++, there are overloads.
571     if (Ctx->getLangOpts().CPlusPlus) {
572       OS << '(';
573       for (const auto &P : FD->parameters()) {
574         if (P != *FD->param_begin())
575           OS << ", ";
576         OS << P->getType().getAsString();
577       }
578       OS << ')';
579     }
580 
581   } else if (isa<BlockDecl>(D)) {
582     PresumedLoc Loc = Ctx->getSourceManager().getPresumedLoc(D->getLocation());
583 
584     if (Loc.isValid()) {
585       OS << "block (line: " << Loc.getLine() << ", col: " << Loc.getColumn()
586          << ')';
587     }
588 
589   } else if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D)) {
590 
591     // FIXME: copy-pasted from CGDebugInfo.cpp.
592     OS << (OMD->isInstanceMethod() ? '-' : '+') << '[';
593     const DeclContext *DC = OMD->getDeclContext();
594     if (const auto *OID = dyn_cast<ObjCImplementationDecl>(DC)) {
595       OS << OID->getName();
596     } else if (const auto *OID = dyn_cast<ObjCInterfaceDecl>(DC)) {
597       OS << OID->getName();
598     } else if (const auto *OC = dyn_cast<ObjCCategoryDecl>(DC)) {
599       if (OC->IsClassExtension()) {
600         OS << OC->getClassInterface()->getName();
601       } else {
602         OS << OC->getIdentifier()->getNameStart() << '('
603            << OC->getIdentifier()->getNameStart() << ')';
604       }
605     } else if (const auto *OCD = dyn_cast<ObjCCategoryImplDecl>(DC)) {
606       OS << ((const NamedDecl *)OCD)->getIdentifier()->getNameStart() << '('
607          << OCD->getIdentifier()->getNameStart() << ')';
608     } else if (isa<ObjCProtocolDecl>(DC)) {
609       // We can extract the type of the class from the self pointer.
610       if (ImplicitParamDecl *SelfDecl = OMD->getSelfDecl()) {
611         QualType ClassTy =
612             cast<ObjCObjectPointerType>(SelfDecl->getType())->getPointeeType();
613         ClassTy.print(OS, PrintingPolicy(LangOptions()));
614       }
615     }
616     OS << ' ' << OMD->getSelector().getAsString() << ']';
617 
618   }
619 
620   return OS.str();
621 }
622 
623 AnalysisConsumer::AnalysisMode
624 AnalysisConsumer::getModeForDecl(Decl *D, AnalysisMode Mode) {
625   if (!Opts->AnalyzeSpecificFunction.empty() &&
626       getFunctionName(D) != Opts->AnalyzeSpecificFunction)
627     return AM_None;
628 
629   // Unless -analyze-all is specified, treat decls differently depending on
630   // where they came from:
631   // - Main source file: run both path-sensitive and non-path-sensitive checks.
632   // - Header files: run non-path-sensitive checks only.
633   // - System headers: don't run any checks.
634   SourceManager &SM = Ctx->getSourceManager();
635   const Stmt *Body = D->getBody();
636   SourceLocation SL = Body ? Body->getLocStart() : D->getLocation();
637   SL = SM.getExpansionLoc(SL);
638 
639   if (!Opts->AnalyzeAll && !SM.isWrittenInMainFile(SL)) {
640     if (SL.isInvalid() || SM.isInSystemHeader(SL))
641       return AM_None;
642     return Mode & ~AM_Path;
643   }
644 
645   return Mode;
646 }
647 
648 void AnalysisConsumer::HandleCode(Decl *D, AnalysisMode Mode,
649                                   ExprEngine::InliningModes IMode,
650                                   SetOfConstDecls *VisitedCallees) {
651   if (!D->hasBody())
652     return;
653   Mode = getModeForDecl(D, Mode);
654   if (Mode == AM_None)
655     return;
656 
657   // Clear the AnalysisManager of old AnalysisDeclContexts.
658   Mgr->ClearContexts();
659   // Ignore autosynthesized code.
660   if (Mgr->getAnalysisDeclContext(D)->isBodyAutosynthesized())
661     return;
662 
663   DisplayFunction(D, Mode, IMode);
664   CFG *DeclCFG = Mgr->getCFG(D);
665   if (DeclCFG) {
666     unsigned CFGSize = DeclCFG->size();
667     MaxCFGSize = MaxCFGSize < CFGSize ? CFGSize : MaxCFGSize;
668   }
669 
670   BugReporter BR(*Mgr);
671 
672   if (Mode & AM_Syntax)
673     checkerMgr->runCheckersOnASTBody(D, *Mgr, BR);
674   if ((Mode & AM_Path) && checkerMgr->hasPathSensitiveCheckers()) {
675     RunPathSensitiveChecks(D, IMode, VisitedCallees);
676     if (IMode != ExprEngine::Inline_Minimal)
677       NumFunctionsAnalyzed++;
678   }
679 }
680 
681 //===----------------------------------------------------------------------===//
682 // Path-sensitive checking.
683 //===----------------------------------------------------------------------===//
684 
685 void AnalysisConsumer::ActionExprEngine(Decl *D, bool ObjCGCEnabled,
686                                         ExprEngine::InliningModes IMode,
687                                         SetOfConstDecls *VisitedCallees) {
688   // Construct the analysis engine.  First check if the CFG is valid.
689   // FIXME: Inter-procedural analysis will need to handle invalid CFGs.
690   if (!Mgr->getCFG(D))
691     return;
692 
693   // See if the LiveVariables analysis scales.
694   if (!Mgr->getAnalysisDeclContext(D)->getAnalysis<RelaxedLiveVariables>())
695     return;
696 
697   ExprEngine Eng(*Mgr, ObjCGCEnabled, VisitedCallees, &FunctionSummaries,IMode);
698 
699   // Set the graph auditor.
700   std::unique_ptr<ExplodedNode::Auditor> Auditor;
701   if (Mgr->options.visualizeExplodedGraphWithUbiGraph) {
702     Auditor = CreateUbiViz();
703     ExplodedNode::SetAuditor(Auditor.get());
704   }
705 
706   // Execute the worklist algorithm.
707   Eng.ExecuteWorkList(Mgr->getAnalysisDeclContextManager().getStackFrame(D),
708                       Mgr->options.getMaxNodesPerTopLevelFunction());
709 
710   // Release the auditor (if any) so that it doesn't monitor the graph
711   // created BugReporter.
712   ExplodedNode::SetAuditor(nullptr);
713 
714   // Visualize the exploded graph.
715   if (Mgr->options.visualizeExplodedGraphWithGraphViz)
716     Eng.ViewGraph(Mgr->options.TrimGraph);
717 
718   // Display warnings.
719   Eng.getBugReporter().FlushReports();
720 }
721 
722 void AnalysisConsumer::RunPathSensitiveChecks(Decl *D,
723                                               ExprEngine::InliningModes IMode,
724                                               SetOfConstDecls *Visited) {
725 
726   switch (Mgr->getLangOpts().getGC()) {
727   case LangOptions::NonGC:
728     ActionExprEngine(D, false, IMode, Visited);
729     break;
730 
731   case LangOptions::GCOnly:
732     ActionExprEngine(D, true, IMode, Visited);
733     break;
734 
735   case LangOptions::HybridGC:
736     ActionExprEngine(D, false, IMode, Visited);
737     ActionExprEngine(D, true, IMode, Visited);
738     break;
739   }
740 }
741 
742 //===----------------------------------------------------------------------===//
743 // AnalysisConsumer creation.
744 //===----------------------------------------------------------------------===//
745 
746 std::unique_ptr<AnalysisASTConsumer>
747 ento::CreateAnalysisConsumer(CompilerInstance &CI) {
748   // Disable the effects of '-Werror' when using the AnalysisConsumer.
749   CI.getPreprocessor().getDiagnostics().setWarningsAsErrors(false);
750 
751   AnalyzerOptionsRef analyzerOpts = CI.getAnalyzerOpts();
752   bool hasModelPath = analyzerOpts->Config.count("model-path") > 0;
753 
754   return llvm::make_unique<AnalysisConsumer>(
755       CI.getPreprocessor(), CI.getFrontendOpts().OutputFile, analyzerOpts,
756       CI.getFrontendOpts().Plugins,
757       hasModelPath ? new ModelInjector(CI) : nullptr);
758 }
759 
760 //===----------------------------------------------------------------------===//
761 // Ubigraph Visualization.  FIXME: Move to separate file.
762 //===----------------------------------------------------------------------===//
763 
764 namespace {
765 
766 class UbigraphViz : public ExplodedNode::Auditor {
767   std::unique_ptr<raw_ostream> Out;
768   std::string Filename;
769   unsigned Cntr;
770 
771   typedef llvm::DenseMap<void*,unsigned> VMap;
772   VMap M;
773 
774 public:
775   UbigraphViz(std::unique_ptr<raw_ostream> Out, StringRef Filename);
776 
777   ~UbigraphViz() override;
778 
779   void AddEdge(ExplodedNode *Src, ExplodedNode *Dst) override;
780 };
781 
782 } // end anonymous namespace
783 
784 static std::unique_ptr<ExplodedNode::Auditor> CreateUbiViz() {
785   SmallString<128> P;
786   int FD;
787   llvm::sys::fs::createTemporaryFile("llvm_ubi", "", FD, P);
788   llvm::errs() << "Writing '" << P << "'.\n";
789 
790   auto Stream = llvm::make_unique<llvm::raw_fd_ostream>(FD, true);
791 
792   return llvm::make_unique<UbigraphViz>(std::move(Stream), P);
793 }
794 
795 void UbigraphViz::AddEdge(ExplodedNode *Src, ExplodedNode *Dst) {
796 
797   assert (Src != Dst && "Self-edges are not allowed.");
798 
799   // Lookup the Src.  If it is a new node, it's a root.
800   VMap::iterator SrcI= M.find(Src);
801   unsigned SrcID;
802 
803   if (SrcI == M.end()) {
804     M[Src] = SrcID = Cntr++;
805     *Out << "('vertex', " << SrcID << ", ('color','#00ff00'))\n";
806   }
807   else
808     SrcID = SrcI->second;
809 
810   // Lookup the Dst.
811   VMap::iterator DstI= M.find(Dst);
812   unsigned DstID;
813 
814   if (DstI == M.end()) {
815     M[Dst] = DstID = Cntr++;
816     *Out << "('vertex', " << DstID << ")\n";
817   }
818   else {
819     // We have hit DstID before.  Change its style to reflect a cache hit.
820     DstID = DstI->second;
821     *Out << "('change_vertex_style', " << DstID << ", 1)\n";
822   }
823 
824   // Add the edge.
825   *Out << "('edge', " << SrcID << ", " << DstID
826        << ", ('arrow','true'), ('oriented', 'true'))\n";
827 }
828 
829 UbigraphViz::UbigraphViz(std::unique_ptr<raw_ostream> OutStream,
830                          StringRef Filename)
831     : Out(std::move(OutStream)), Filename(Filename), Cntr(0) {
832 
833   *Out << "('vertex_style_attribute', 0, ('shape', 'icosahedron'))\n";
834   *Out << "('vertex_style', 1, 0, ('shape', 'sphere'), ('color', '#ffcc66'),"
835           " ('size', '1.5'))\n";
836 }
837 
838 UbigraphViz::~UbigraphViz() {
839   Out.reset();
840   llvm::errs() << "Running 'ubiviz' program... ";
841   std::string ErrMsg;
842   std::string Ubiviz;
843   if (auto Path = llvm::sys::findProgramByName("ubiviz"))
844     Ubiviz = *Path;
845   const char *args[] = {Ubiviz.c_str(), Filename.c_str(), nullptr};
846 
847   if (llvm::sys::ExecuteAndWait(Ubiviz, &args[0], nullptr, nullptr, 0, 0,
848                                 &ErrMsg)) {
849     llvm::errs() << "Error viewing graph: " << ErrMsg << "\n";
850   }
851 
852   // Delete the file.
853   llvm::sys::fs::remove(Filename);
854 }
855