xref: /freebsd/contrib/llvm-project/clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp (revision 4824e7fd18a1223177218d4aec1b3c6c5c4a444e)
1 //===--- AnalysisConsumer.cpp - ASTConsumer for running Analyses ----------===//
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 // "Meta" ASTConsumer for running different source analyses.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"
14 #include "ModelInjector.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/DeclCXX.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/RecursiveASTVisitor.h"
19 #include "clang/Analysis/Analyses/LiveVariables.h"
20 #include "clang/Analysis/CFG.h"
21 #include "clang/Analysis/CallGraph.h"
22 #include "clang/Analysis/CodeInjector.h"
23 #include "clang/Analysis/MacroExpansionContext.h"
24 #include "clang/Analysis/PathDiagnostic.h"
25 #include "clang/Basic/SourceManager.h"
26 #include "clang/CrossTU/CrossTranslationUnit.h"
27 #include "clang/Frontend/CompilerInstance.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Rewrite/Core/Rewriter.h"
30 #include "clang/StaticAnalyzer/Checkers/LocalCheckers.h"
31 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h"
32 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
33 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
34 #include "clang/StaticAnalyzer/Core/PathDiagnosticConsumers.h"
35 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
36 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
37 #include "llvm/ADT/PostOrderIterator.h"
38 #include "llvm/ADT/Statistic.h"
39 #include "llvm/Support/FileSystem.h"
40 #include "llvm/Support/Path.h"
41 #include "llvm/Support/Program.h"
42 #include "llvm/Support/Timer.h"
43 #include "llvm/Support/raw_ostream.h"
44 #include <memory>
45 #include <queue>
46 #include <utility>
47 
48 using namespace clang;
49 using namespace ento;
50 
51 #define DEBUG_TYPE "AnalysisConsumer"
52 
53 STATISTIC(NumFunctionTopLevel, "The # of functions at top level.");
54 STATISTIC(NumFunctionsAnalyzed,
55                       "The # of functions and blocks analyzed (as top level "
56                       "with inlining turned on).");
57 STATISTIC(NumBlocksInAnalyzedFunctions,
58                       "The # of basic blocks in the analyzed functions.");
59 STATISTIC(NumVisitedBlocksInAnalyzedFunctions,
60           "The # of visited basic blocks in the analyzed functions.");
61 STATISTIC(PercentReachableBlocks, "The % of reachable basic blocks.");
62 STATISTIC(MaxCFGSize, "The maximum number of basic blocks in a function.");
63 
64 //===----------------------------------------------------------------------===//
65 // AnalysisConsumer declaration.
66 //===----------------------------------------------------------------------===//
67 
68 namespace {
69 
70 class AnalysisConsumer : public AnalysisASTConsumer,
71                          public RecursiveASTVisitor<AnalysisConsumer> {
72   enum {
73     AM_None = 0,
74     AM_Syntax = 0x1,
75     AM_Path = 0x2
76   };
77   typedef unsigned AnalysisMode;
78 
79   /// Mode of the analyzes while recursively visiting Decls.
80   AnalysisMode RecVisitorMode;
81   /// Bug Reporter to use while recursively visiting Decls.
82   BugReporter *RecVisitorBR;
83 
84   std::vector<std::function<void(CheckerRegistry &)>> CheckerRegistrationFns;
85 
86 public:
87   ASTContext *Ctx;
88   Preprocessor &PP;
89   const std::string OutDir;
90   AnalyzerOptionsRef Opts;
91   ArrayRef<std::string> Plugins;
92   CodeInjector *Injector;
93   cross_tu::CrossTranslationUnitContext CTU;
94 
95   /// Stores the declarations from the local translation unit.
96   /// Note, we pre-compute the local declarations at parse time as an
97   /// optimization to make sure we do not deserialize everything from disk.
98   /// The local declaration to all declarations ratio might be very small when
99   /// working with a PCH file.
100   SetOfDecls LocalTUDecls;
101 
102   MacroExpansionContext MacroExpansions;
103 
104   // Set of PathDiagnosticConsumers.  Owned by AnalysisManager.
105   PathDiagnosticConsumers PathConsumers;
106 
107   StoreManagerCreator CreateStoreMgr;
108   ConstraintManagerCreator CreateConstraintMgr;
109 
110   std::unique_ptr<CheckerManager> checkerMgr;
111   std::unique_ptr<AnalysisManager> Mgr;
112 
113   /// Time the analyzes time of each translation unit.
114   std::unique_ptr<llvm::TimerGroup> AnalyzerTimers;
115   std::unique_ptr<llvm::Timer> SyntaxCheckTimer;
116   std::unique_ptr<llvm::Timer> ExprEngineTimer;
117   std::unique_ptr<llvm::Timer> BugReporterTimer;
118 
119   /// The information about analyzed functions shared throughout the
120   /// translation unit.
121   FunctionSummariesTy FunctionSummaries;
122 
123   AnalysisConsumer(CompilerInstance &CI, const std::string &outdir,
124                    AnalyzerOptionsRef opts, ArrayRef<std::string> plugins,
125                    CodeInjector *injector)
126       : RecVisitorMode(0), RecVisitorBR(nullptr), Ctx(nullptr),
127         PP(CI.getPreprocessor()), OutDir(outdir), Opts(std::move(opts)),
128         Plugins(plugins), Injector(injector), CTU(CI),
129         MacroExpansions(CI.getLangOpts()) {
130     DigestAnalyzerOptions();
131     if (Opts->AnalyzerDisplayProgress || Opts->PrintStats ||
132         Opts->ShouldSerializeStats) {
133       AnalyzerTimers = std::make_unique<llvm::TimerGroup>(
134           "analyzer", "Analyzer timers");
135       SyntaxCheckTimer = std::make_unique<llvm::Timer>(
136           "syntaxchecks", "Syntax-based analysis time", *AnalyzerTimers);
137       ExprEngineTimer = std::make_unique<llvm::Timer>(
138           "exprengine", "Path exploration time", *AnalyzerTimers);
139       BugReporterTimer = std::make_unique<llvm::Timer>(
140           "bugreporter", "Path-sensitive report post-processing time",
141           *AnalyzerTimers);
142     }
143 
144     if (Opts->PrintStats || Opts->ShouldSerializeStats) {
145       llvm::EnableStatistics(/* PrintOnExit= */ false);
146     }
147 
148     if (Opts->ShouldDisplayMacroExpansions)
149       MacroExpansions.registerForPreprocessor(PP);
150   }
151 
152   ~AnalysisConsumer() override {
153     if (Opts->PrintStats) {
154       llvm::PrintStatistics();
155     }
156   }
157 
158   void DigestAnalyzerOptions() {
159     switch (Opts->AnalysisDiagOpt) {
160     case PD_NONE:
161       break;
162 #define ANALYSIS_DIAGNOSTICS(NAME, CMDFLAG, DESC, CREATEFN)                    \
163   case PD_##NAME:                                                              \
164     CREATEFN(Opts->getDiagOpts(), PathConsumers, OutDir, PP, CTU,              \
165              MacroExpansions);                                                 \
166     break;
167 #include "clang/StaticAnalyzer/Core/Analyses.def"
168     default:
169       llvm_unreachable("Unknown analyzer output type!");
170     }
171 
172     // Create the analyzer component creators.
173     switch (Opts->AnalysisStoreOpt) {
174     default:
175       llvm_unreachable("Unknown store manager.");
176 #define ANALYSIS_STORE(NAME, CMDFLAG, DESC, CREATEFN)           \
177       case NAME##Model: CreateStoreMgr = CREATEFN; break;
178 #include "clang/StaticAnalyzer/Core/Analyses.def"
179     }
180 
181     switch (Opts->AnalysisConstraintsOpt) {
182     default:
183       llvm_unreachable("Unknown constraint manager.");
184 #define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATEFN)     \
185       case NAME##Model: CreateConstraintMgr = CREATEFN; break;
186 #include "clang/StaticAnalyzer/Core/Analyses.def"
187     }
188   }
189 
190   void DisplayTime(llvm::TimeRecord &Time) {
191     if (!Opts->AnalyzerDisplayProgress) {
192       return;
193     }
194     llvm::errs() << " : " << llvm::format("%1.1f", Time.getWallTime() * 1000)
195                  << " ms\n";
196   }
197 
198   void DisplayFunction(const Decl *D, AnalysisMode Mode,
199                        ExprEngine::InliningModes IMode) {
200     if (!Opts->AnalyzerDisplayProgress)
201       return;
202 
203     SourceManager &SM = Mgr->getASTContext().getSourceManager();
204     PresumedLoc Loc = SM.getPresumedLoc(D->getLocation());
205     if (Loc.isValid()) {
206       llvm::errs() << "ANALYZE";
207 
208       if (Mode == AM_Syntax)
209         llvm::errs() << " (Syntax)";
210       else if (Mode == AM_Path) {
211         llvm::errs() << " (Path, ";
212         switch (IMode) {
213         case ExprEngine::Inline_Minimal:
214           llvm::errs() << " Inline_Minimal";
215           break;
216         case ExprEngine::Inline_Regular:
217           llvm::errs() << " Inline_Regular";
218           break;
219         }
220         llvm::errs() << ")";
221       } else
222         assert(Mode == (AM_Syntax | AM_Path) && "Unexpected mode!");
223 
224       llvm::errs() << ": " << Loc.getFilename() << ' '
225                    << AnalysisDeclContext::getFunctionName(D);
226     }
227   }
228 
229   void Initialize(ASTContext &Context) override {
230     Ctx = &Context;
231     checkerMgr = std::make_unique<CheckerManager>(*Ctx, *Opts, PP, Plugins,
232                                                   CheckerRegistrationFns);
233 
234     Mgr = std::make_unique<AnalysisManager>(*Ctx, PP, PathConsumers,
235                                             CreateStoreMgr, CreateConstraintMgr,
236                                             checkerMgr.get(), *Opts, Injector);
237   }
238 
239   /// Store the top level decls in the set to be processed later on.
240   /// (Doing this pre-processing avoids deserialization of data from PCH.)
241   bool HandleTopLevelDecl(DeclGroupRef D) override;
242   void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override;
243 
244   void HandleTranslationUnit(ASTContext &C) override;
245 
246   /// Determine which inlining mode should be used when this function is
247   /// analyzed. This allows to redefine the default inlining policies when
248   /// analyzing a given function.
249   ExprEngine::InliningModes
250     getInliningModeForFunction(const Decl *D, const SetOfConstDecls &Visited);
251 
252   /// Build the call graph for all the top level decls of this TU and
253   /// use it to define the order in which the functions should be visited.
254   void HandleDeclsCallGraph(const unsigned LocalTUDeclsSize);
255 
256   /// Run analyzes(syntax or path sensitive) on the given function.
257   /// \param Mode - determines if we are requesting syntax only or path
258   /// sensitive only analysis.
259   /// \param VisitedCallees - The output parameter, which is populated with the
260   /// set of functions which should be considered analyzed after analyzing the
261   /// given root function.
262   void HandleCode(Decl *D, AnalysisMode Mode,
263                   ExprEngine::InliningModes IMode = ExprEngine::Inline_Minimal,
264                   SetOfConstDecls *VisitedCallees = nullptr);
265 
266   void RunPathSensitiveChecks(Decl *D,
267                               ExprEngine::InliningModes IMode,
268                               SetOfConstDecls *VisitedCallees);
269 
270   /// Visitors for the RecursiveASTVisitor.
271   bool shouldWalkTypesOfTypeLocs() const { return false; }
272 
273   /// Handle callbacks for arbitrary Decls.
274   bool VisitDecl(Decl *D) {
275     AnalysisMode Mode = getModeForDecl(D, RecVisitorMode);
276     if (Mode & AM_Syntax) {
277       if (SyntaxCheckTimer)
278         SyntaxCheckTimer->startTimer();
279       checkerMgr->runCheckersOnASTDecl(D, *Mgr, *RecVisitorBR);
280       if (SyntaxCheckTimer)
281         SyntaxCheckTimer->stopTimer();
282     }
283     return true;
284   }
285 
286   bool VisitVarDecl(VarDecl *VD) {
287     if (!Opts->IsNaiveCTUEnabled)
288       return true;
289 
290     if (VD->hasExternalStorage() || VD->isStaticDataMember()) {
291       if (!cross_tu::containsConst(VD, *Ctx))
292         return true;
293     } else {
294       // Cannot be initialized in another TU.
295       return true;
296     }
297 
298     if (VD->getAnyInitializer())
299       return true;
300 
301     llvm::Expected<const VarDecl *> CTUDeclOrError =
302       CTU.getCrossTUDefinition(VD, Opts->CTUDir, Opts->CTUIndexName,
303                                Opts->DisplayCTUProgress);
304 
305     if (!CTUDeclOrError) {
306       handleAllErrors(CTUDeclOrError.takeError(),
307                       [&](const cross_tu::IndexError &IE) {
308                         CTU.emitCrossTUDiagnostics(IE);
309                       });
310     }
311 
312     return true;
313   }
314 
315   bool VisitFunctionDecl(FunctionDecl *FD) {
316     IdentifierInfo *II = FD->getIdentifier();
317     if (II && II->getName().startswith("__inline"))
318       return true;
319 
320     // We skip function template definitions, as their semantics is
321     // only determined when they are instantiated.
322     if (FD->isThisDeclarationADefinition() &&
323         !FD->isDependentContext()) {
324       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
325       HandleCode(FD, RecVisitorMode);
326     }
327     return true;
328   }
329 
330   bool VisitObjCMethodDecl(ObjCMethodDecl *MD) {
331     if (MD->isThisDeclarationADefinition()) {
332       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
333       HandleCode(MD, RecVisitorMode);
334     }
335     return true;
336   }
337 
338   bool VisitBlockDecl(BlockDecl *BD) {
339     if (BD->hasBody()) {
340       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
341       // Since we skip function template definitions, we should skip blocks
342       // declared in those functions as well.
343       if (!BD->isDependentContext()) {
344         HandleCode(BD, RecVisitorMode);
345       }
346     }
347     return true;
348   }
349 
350   void AddDiagnosticConsumer(PathDiagnosticConsumer *Consumer) override {
351     PathConsumers.push_back(Consumer);
352   }
353 
354   void AddCheckerRegistrationFn(std::function<void(CheckerRegistry&)> Fn) override {
355     CheckerRegistrationFns.push_back(std::move(Fn));
356   }
357 
358 private:
359   void storeTopLevelDecls(DeclGroupRef DG);
360   std::string getFunctionName(const Decl *D);
361 
362   /// Check if we should skip (not analyze) the given function.
363   AnalysisMode getModeForDecl(Decl *D, AnalysisMode Mode);
364   void runAnalysisOnTranslationUnit(ASTContext &C);
365 
366   /// Print \p S to stderr if \c Opts->AnalyzerDisplayProgress is set.
367   void reportAnalyzerProgress(StringRef S);
368 }; // namespace
369 } // end anonymous namespace
370 
371 
372 //===----------------------------------------------------------------------===//
373 // AnalysisConsumer implementation.
374 //===----------------------------------------------------------------------===//
375 bool AnalysisConsumer::HandleTopLevelDecl(DeclGroupRef DG) {
376   storeTopLevelDecls(DG);
377   return true;
378 }
379 
380 void AnalysisConsumer::HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) {
381   storeTopLevelDecls(DG);
382 }
383 
384 void AnalysisConsumer::storeTopLevelDecls(DeclGroupRef DG) {
385   for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) {
386 
387     // Skip ObjCMethodDecl, wait for the objc container to avoid
388     // analyzing twice.
389     if (isa<ObjCMethodDecl>(*I))
390       continue;
391 
392     LocalTUDecls.push_back(*I);
393   }
394 }
395 
396 static bool shouldSkipFunction(const Decl *D,
397                                const SetOfConstDecls &Visited,
398                                const SetOfConstDecls &VisitedAsTopLevel) {
399   if (VisitedAsTopLevel.count(D))
400     return true;
401 
402   // Skip analysis of inheriting constructors as top-level functions. These
403   // constructors don't even have a body written down in the code, so even if
404   // we find a bug, we won't be able to display it.
405   if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
406     if (CD->isInheritingConstructor())
407       return true;
408 
409   // We want to re-analyse the functions as top level in the following cases:
410   // - The 'init' methods should be reanalyzed because
411   //   ObjCNonNilReturnValueChecker assumes that '[super init]' never returns
412   //   'nil' and unless we analyze the 'init' functions as top level, we will
413   //   not catch errors within defensive code.
414   // - We want to reanalyze all ObjC methods as top level to report Retain
415   //   Count naming convention errors more aggressively.
416   if (isa<ObjCMethodDecl>(D))
417     return false;
418   // We also want to reanalyze all C++ copy and move assignment operators to
419   // separately check the two cases where 'this' aliases with the parameter and
420   // where it may not. (cplusplus.SelfAssignmentChecker)
421   if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
422     if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())
423       return false;
424   }
425 
426   // Otherwise, if we visited the function before, do not reanalyze it.
427   return Visited.count(D);
428 }
429 
430 ExprEngine::InliningModes
431 AnalysisConsumer::getInliningModeForFunction(const Decl *D,
432                                              const SetOfConstDecls &Visited) {
433   // We want to reanalyze all ObjC methods as top level to report Retain
434   // Count naming convention errors more aggressively. But we should tune down
435   // inlining when reanalyzing an already inlined function.
436   if (Visited.count(D) && isa<ObjCMethodDecl>(D)) {
437     const ObjCMethodDecl *ObjCM = cast<ObjCMethodDecl>(D);
438     if (ObjCM->getMethodFamily() != OMF_init)
439       return ExprEngine::Inline_Minimal;
440   }
441 
442   return ExprEngine::Inline_Regular;
443 }
444 
445 void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
446   // Build the Call Graph by adding all the top level declarations to the graph.
447   // Note: CallGraph can trigger deserialization of more items from a pch
448   // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
449   // We rely on random access to add the initially processed Decls to CG.
450   CallGraph CG;
451   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
452     CG.addToCallGraph(LocalTUDecls[i]);
453   }
454 
455   // Walk over all of the call graph nodes in topological order, so that we
456   // analyze parents before the children. Skip the functions inlined into
457   // the previously processed functions. Use external Visited set to identify
458   // inlined functions. The topological order allows the "do not reanalyze
459   // previously inlined function" performance heuristic to be triggered more
460   // often.
461   SetOfConstDecls Visited;
462   SetOfConstDecls VisitedAsTopLevel;
463   llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
464   for (llvm::ReversePostOrderTraversal<clang::CallGraph*>::rpo_iterator
465          I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
466     NumFunctionTopLevel++;
467 
468     CallGraphNode *N = *I;
469     Decl *D = N->getDecl();
470 
471     // Skip the abstract root node.
472     if (!D)
473       continue;
474 
475     // Skip the functions which have been processed already or previously
476     // inlined.
477     if (shouldSkipFunction(D, Visited, VisitedAsTopLevel))
478       continue;
479 
480     // Analyze the function.
481     SetOfConstDecls VisitedCallees;
482 
483     HandleCode(D, AM_Path, getInliningModeForFunction(D, Visited),
484                (Mgr->options.InliningMode == All ? nullptr : &VisitedCallees));
485 
486     // Add the visited callees to the global visited set.
487     for (const Decl *Callee : VisitedCallees)
488       // Decls from CallGraph are already canonical. But Decls coming from
489       // CallExprs may be not. We should canonicalize them manually.
490       Visited.insert(isa<ObjCMethodDecl>(Callee) ? Callee
491                                                  : Callee->getCanonicalDecl());
492     VisitedAsTopLevel.insert(D);
493   }
494 }
495 
496 static bool isBisonFile(ASTContext &C) {
497   const SourceManager &SM = C.getSourceManager();
498   FileID FID = SM.getMainFileID();
499   StringRef Buffer = SM.getBufferOrFake(FID).getBuffer();
500   if (Buffer.startswith("/* A Bison parser, made by"))
501     return true;
502   return false;
503 }
504 
505 void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
506   BugReporter BR(*Mgr);
507   TranslationUnitDecl *TU = C.getTranslationUnitDecl();
508   if (SyntaxCheckTimer)
509     SyntaxCheckTimer->startTimer();
510   checkerMgr->runCheckersOnASTDecl(TU, *Mgr, BR);
511   if (SyntaxCheckTimer)
512     SyntaxCheckTimer->stopTimer();
513 
514   // Run the AST-only checks using the order in which functions are defined.
515   // If inlining is not turned on, use the simplest function order for path
516   // sensitive analyzes as well.
517   RecVisitorMode = AM_Syntax;
518   if (!Mgr->shouldInlineCall())
519     RecVisitorMode |= AM_Path;
520   RecVisitorBR = &BR;
521 
522   // Process all the top level declarations.
523   //
524   // Note: TraverseDecl may modify LocalTUDecls, but only by appending more
525   // entries.  Thus we don't use an iterator, but rely on LocalTUDecls
526   // random access.  By doing so, we automatically compensate for iterators
527   // possibly being invalidated, although this is a bit slower.
528   const unsigned LocalTUDeclsSize = LocalTUDecls.size();
529   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
530     TraverseDecl(LocalTUDecls[i]);
531   }
532 
533   if (Mgr->shouldInlineCall())
534     HandleDeclsCallGraph(LocalTUDeclsSize);
535 
536   // After all decls handled, run checkers on the entire TranslationUnit.
537   checkerMgr->runCheckersOnEndOfTranslationUnit(TU, *Mgr, BR);
538 
539   BR.FlushReports();
540   RecVisitorBR = nullptr;
541 }
542 
543 void AnalysisConsumer::reportAnalyzerProgress(StringRef S) {
544   if (Opts->AnalyzerDisplayProgress)
545     llvm::errs() << S;
546 }
547 
548 void AnalysisConsumer::HandleTranslationUnit(ASTContext &C) {
549 
550   // Don't run the actions if an error has occurred with parsing the file.
551   DiagnosticsEngine &Diags = PP.getDiagnostics();
552   if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
553     return;
554 
555   if (isBisonFile(C)) {
556     reportAnalyzerProgress("Skipping bison-generated file\n");
557   } else if (Opts->DisableAllCheckers) {
558 
559     // Don't analyze if the user explicitly asked for no checks to be performed
560     // on this file.
561     reportAnalyzerProgress("All checks are disabled using a supplied option\n");
562   } else {
563     // Otherwise, just run the analysis.
564     runAnalysisOnTranslationUnit(C);
565   }
566 
567   // Count how many basic blocks we have not covered.
568   NumBlocksInAnalyzedFunctions = FunctionSummaries.getTotalNumBasicBlocks();
569   NumVisitedBlocksInAnalyzedFunctions =
570       FunctionSummaries.getTotalNumVisitedBasicBlocks();
571   if (NumBlocksInAnalyzedFunctions > 0)
572     PercentReachableBlocks =
573       (FunctionSummaries.getTotalNumVisitedBasicBlocks() * 100) /
574         NumBlocksInAnalyzedFunctions;
575 
576   // Explicitly destroy the PathDiagnosticConsumer.  This will flush its output.
577   // FIXME: This should be replaced with something that doesn't rely on
578   // side-effects in PathDiagnosticConsumer's destructor. This is required when
579   // used with option -disable-free.
580   Mgr.reset();
581 }
582 
583 AnalysisConsumer::AnalysisMode
584 AnalysisConsumer::getModeForDecl(Decl *D, AnalysisMode Mode) {
585   if (!Opts->AnalyzeSpecificFunction.empty() &&
586       AnalysisDeclContext::getFunctionName(D) != Opts->AnalyzeSpecificFunction)
587     return AM_None;
588 
589   // Unless -analyze-all is specified, treat decls differently depending on
590   // where they came from:
591   // - Main source file: run both path-sensitive and non-path-sensitive checks.
592   // - Header files: run non-path-sensitive checks only.
593   // - System headers: don't run any checks.
594   if (Opts->AnalyzeAll)
595     return Mode;
596 
597   const SourceManager &SM = Ctx->getSourceManager();
598 
599   const SourceLocation Loc = [&SM](Decl *D) -> SourceLocation {
600     const Stmt *Body = D->getBody();
601     SourceLocation SL = Body ? Body->getBeginLoc() : D->getLocation();
602     return SM.getExpansionLoc(SL);
603   }(D);
604 
605   // Ignore system headers.
606   if (Loc.isInvalid() || SM.isInSystemHeader(Loc))
607     return AM_None;
608 
609   // Disable path sensitive analysis in user-headers.
610   if (!Mgr->isInCodeFile(Loc))
611     return Mode & ~AM_Path;
612 
613   return Mode;
614 }
615 
616 void AnalysisConsumer::HandleCode(Decl *D, AnalysisMode Mode,
617                                   ExprEngine::InliningModes IMode,
618                                   SetOfConstDecls *VisitedCallees) {
619   if (!D->hasBody())
620     return;
621   Mode = getModeForDecl(D, Mode);
622   if (Mode == AM_None)
623     return;
624 
625   // Clear the AnalysisManager of old AnalysisDeclContexts.
626   Mgr->ClearContexts();
627   // Ignore autosynthesized code.
628   if (Mgr->getAnalysisDeclContext(D)->isBodyAutosynthesized())
629     return;
630 
631   CFG *DeclCFG = Mgr->getCFG(D);
632   if (DeclCFG)
633     MaxCFGSize.updateMax(DeclCFG->size());
634 
635   DisplayFunction(D, Mode, IMode);
636   BugReporter BR(*Mgr);
637 
638   if (Mode & AM_Syntax) {
639     llvm::TimeRecord CheckerStartTime;
640     if (SyntaxCheckTimer) {
641       CheckerStartTime = SyntaxCheckTimer->getTotalTime();
642       SyntaxCheckTimer->startTimer();
643     }
644     checkerMgr->runCheckersOnASTBody(D, *Mgr, BR);
645     if (SyntaxCheckTimer) {
646       SyntaxCheckTimer->stopTimer();
647       llvm::TimeRecord CheckerEndTime = SyntaxCheckTimer->getTotalTime();
648       CheckerEndTime -= CheckerStartTime;
649       DisplayTime(CheckerEndTime);
650     }
651   }
652 
653   BR.FlushReports();
654 
655   if ((Mode & AM_Path) && checkerMgr->hasPathSensitiveCheckers()) {
656     RunPathSensitiveChecks(D, IMode, VisitedCallees);
657     if (IMode != ExprEngine::Inline_Minimal)
658       NumFunctionsAnalyzed++;
659   }
660 }
661 
662 //===----------------------------------------------------------------------===//
663 // Path-sensitive checking.
664 //===----------------------------------------------------------------------===//
665 
666 void AnalysisConsumer::RunPathSensitiveChecks(Decl *D,
667                                               ExprEngine::InliningModes IMode,
668                                               SetOfConstDecls *VisitedCallees) {
669   // Construct the analysis engine.  First check if the CFG is valid.
670   // FIXME: Inter-procedural analysis will need to handle invalid CFGs.
671   if (!Mgr->getCFG(D))
672     return;
673 
674   // See if the LiveVariables analysis scales.
675   if (!Mgr->getAnalysisDeclContext(D)->getAnalysis<RelaxedLiveVariables>())
676     return;
677 
678   ExprEngine Eng(CTU, *Mgr, VisitedCallees, &FunctionSummaries, IMode);
679 
680   // Execute the worklist algorithm.
681   llvm::TimeRecord ExprEngineStartTime;
682   if (ExprEngineTimer) {
683     ExprEngineStartTime = ExprEngineTimer->getTotalTime();
684     ExprEngineTimer->startTimer();
685   }
686   Eng.ExecuteWorkList(Mgr->getAnalysisDeclContextManager().getStackFrame(D),
687                       Mgr->options.MaxNodesPerTopLevelFunction);
688   if (ExprEngineTimer) {
689     ExprEngineTimer->stopTimer();
690     llvm::TimeRecord ExprEngineEndTime = ExprEngineTimer->getTotalTime();
691     ExprEngineEndTime -= ExprEngineStartTime;
692     DisplayTime(ExprEngineEndTime);
693   }
694 
695   if (!Mgr->options.DumpExplodedGraphTo.empty())
696     Eng.DumpGraph(Mgr->options.TrimGraph, Mgr->options.DumpExplodedGraphTo);
697 
698   // Visualize the exploded graph.
699   if (Mgr->options.visualizeExplodedGraphWithGraphViz)
700     Eng.ViewGraph(Mgr->options.TrimGraph);
701 
702   // Display warnings.
703   if (BugReporterTimer)
704     BugReporterTimer->startTimer();
705   Eng.getBugReporter().FlushReports();
706   if (BugReporterTimer)
707     BugReporterTimer->stopTimer();
708 }
709 
710 //===----------------------------------------------------------------------===//
711 // AnalysisConsumer creation.
712 //===----------------------------------------------------------------------===//
713 
714 std::unique_ptr<AnalysisASTConsumer>
715 ento::CreateAnalysisConsumer(CompilerInstance &CI) {
716   // Disable the effects of '-Werror' when using the AnalysisConsumer.
717   CI.getPreprocessor().getDiagnostics().setWarningsAsErrors(false);
718 
719   AnalyzerOptionsRef analyzerOpts = CI.getAnalyzerOpts();
720   bool hasModelPath = analyzerOpts->Config.count("model-path") > 0;
721 
722   return std::make_unique<AnalysisConsumer>(
723       CI, CI.getFrontendOpts().OutputFile, analyzerOpts,
724       CI.getFrontendOpts().Plugins,
725       hasModelPath ? new ModelInjector(CI) : nullptr);
726 }
727