clang/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp

   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/Core/AnalyzerOptions.h"
  31 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
  32 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
  33 #include "clang/StaticAnalyzer/Core/PathDiagnosticConsumers.h"
  34 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
  35 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
  36 #include "llvm/ADT/PostOrderIterator.h"
  37 #include "llvm/ADT/ScopeExit.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   AnalyzerOptions &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                    AnalyzerOptions &opts, ArrayRef<std::string> plugins,
 125                    CodeInjector *injector)
 126       : RecVisitorMode(0), RecVisitorBR(nullptr), Ctx(nullptr),
 127         PP(CI.getPreprocessor()), OutDir(outdir), Opts(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(/* DoPrintOnExit= */ 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     CreateStoreMgr = &CreateRegionStoreManager;
 174
 175     switch (Opts.AnalysisConstraintsOpt) {
 176     default:
 177       llvm_unreachable("Unknown constraint manager.");
 178 #define ANALYSIS_CONSTRAINTS(NAME, CMDFLAG, DESC, CREATEFN)     \
 179       case NAME##Model: CreateConstraintMgr = CREATEFN; break;
 180 #include "clang/StaticAnalyzer/Core/Analyses.def"
 181     }
 182   }
 183
 184   void DisplayTime(llvm::TimeRecord &Time) {
 185     if (!Opts.AnalyzerDisplayProgress) {
 186       return;
 187     }
 188     llvm::errs() << " : " << llvm::format("%1.1f", Time.getWallTime() * 1000)
 189                  << " ms\n";
 190   }
 191
 192   void DisplayFunction(const Decl *D, AnalysisMode Mode,
 193                        ExprEngine::InliningModes IMode) {
 194     if (!Opts.AnalyzerDisplayProgress)
 195       return;
 196
 197     SourceManager &SM = Mgr->getASTContext().getSourceManager();
 198     PresumedLoc Loc = SM.getPresumedLoc(D->getLocation());
 199     if (Loc.isValid()) {
 200       llvm::errs() << "ANALYZE";
 201
 202       if (Mode == AM_Syntax)
 203         llvm::errs() << " (Syntax)";
 204       else if (Mode == AM_Path) {
 205         llvm::errs() << " (Path, ";
 206         switch (IMode) {
 207         case ExprEngine::Inline_Minimal:
 208           llvm::errs() << " Inline_Minimal";
 209           break;
 210         case ExprEngine::Inline_Regular:
 211           llvm::errs() << " Inline_Regular";
 212           break;
 213         }
 214         llvm::errs() << ")";
 215       } else
 216         assert(Mode == (AM_Syntax | AM_Path) && "Unexpected mode!");
 217
 218       llvm::errs() << ": " << Loc.getFilename() << ' '
 219                    << AnalysisDeclContext::getFunctionName(D);
 220     }
 221   }
 222
 223   void Initialize(ASTContext &Context) override {
 224     Ctx = &Context;
 225     checkerMgr = std::make_unique<CheckerManager>(*Ctx, Opts, PP, Plugins,
 226                                                   CheckerRegistrationFns);
 227
 228     Mgr = std::make_unique<AnalysisManager>(*Ctx, PP, PathConsumers,
 229                                             CreateStoreMgr, CreateConstraintMgr,
 230                                             checkerMgr.get(), Opts, Injector);
 231   }
 232
 233   /// Store the top level decls in the set to be processed later on.
 234   /// (Doing this pre-processing avoids deserialization of data from PCH.)
 235   bool HandleTopLevelDecl(DeclGroupRef D) override;
 236   void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override;
 237
 238   void HandleTranslationUnit(ASTContext &C) override;
 239
 240   /// Determine which inlining mode should be used when this function is
 241   /// analyzed. This allows to redefine the default inlining policies when
 242   /// analyzing a given function.
 243   ExprEngine::InliningModes
 244     getInliningModeForFunction(const Decl *D, const SetOfConstDecls &Visited);
 245
 246   /// Build the call graph for all the top level decls of this TU and
 247   /// use it to define the order in which the functions should be visited.
 248   void HandleDeclsCallGraph(const unsigned LocalTUDeclsSize);
 249
 250   /// Run analyzes(syntax or path sensitive) on the given function.
 251   /// \param Mode - determines if we are requesting syntax only or path
 252   /// sensitive only analysis.
 253   /// \param VisitedCallees - The output parameter, which is populated with the
 254   /// set of functions which should be considered analyzed after analyzing the
 255   /// given root function.
 256   void HandleCode(Decl *D, AnalysisMode Mode,
 257                   ExprEngine::InliningModes IMode = ExprEngine::Inline_Minimal,
 258                   SetOfConstDecls *VisitedCallees = nullptr);
 259
 260   void RunPathSensitiveChecks(Decl *D,
 261                               ExprEngine::InliningModes IMode,
 262                               SetOfConstDecls *VisitedCallees);
 263
 264   /// Visitors for the RecursiveASTVisitor.
 265   bool shouldWalkTypesOfTypeLocs() const { return false; }
 266
 267   /// Handle callbacks for arbitrary Decls.
 268   bool VisitDecl(Decl *D) {
 269     AnalysisMode Mode = getModeForDecl(D, RecVisitorMode);
 270     if (Mode & AM_Syntax) {
 271       if (SyntaxCheckTimer)
 272         SyntaxCheckTimer->startTimer();
 273       checkerMgr->runCheckersOnASTDecl(D, *Mgr, *RecVisitorBR);
 274       if (SyntaxCheckTimer)
 275         SyntaxCheckTimer->stopTimer();
 276     }
 277     return true;
 278   }
 279
 280   bool VisitVarDecl(VarDecl *VD) {
 281     if (!Opts.IsNaiveCTUEnabled)
 282       return true;
 283
 284     if (VD->hasExternalStorage() || VD->isStaticDataMember()) {
 285       if (!cross_tu::shouldImport(VD, *Ctx))
 286         return true;
 287     } else {
 288       // Cannot be initialized in another TU.
 289       return true;
 290     }
 291
 292     if (VD->getAnyInitializer())
 293       return true;
 294
 295     llvm::Expected<const VarDecl *> CTUDeclOrError =
 296       CTU.getCrossTUDefinition(VD, Opts.CTUDir, Opts.CTUIndexName,
 297                                Opts.DisplayCTUProgress);
 298
 299     if (!CTUDeclOrError) {
 300       handleAllErrors(CTUDeclOrError.takeError(),
 301                       [&](const cross_tu::IndexError &IE) {
 302                         CTU.emitCrossTUDiagnostics(IE);
 303                       });
 304     }
 305
 306     return true;
 307   }
 308
 309   bool VisitFunctionDecl(FunctionDecl *FD) {
 310     IdentifierInfo *II = FD->getIdentifier();
 311     if (II && II->getName().startswith("__inline"))
 312       return true;
 313
 314     // We skip function template definitions, as their semantics is
 315     // only determined when they are instantiated.
 316     if (FD->isThisDeclarationADefinition() &&
 317         !FD->isDependentContext()) {
 318       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
 319       HandleCode(FD, RecVisitorMode);
 320     }
 321     return true;
 322   }
 323
 324   bool VisitObjCMethodDecl(ObjCMethodDecl *MD) {
 325     if (MD->isThisDeclarationADefinition()) {
 326       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
 327       HandleCode(MD, RecVisitorMode);
 328     }
 329     return true;
 330   }
 331
 332   bool VisitBlockDecl(BlockDecl *BD) {
 333     if (BD->hasBody()) {
 334       assert(RecVisitorMode == AM_Syntax || Mgr->shouldInlineCall() == false);
 335       // Since we skip function template definitions, we should skip blocks
 336       // declared in those functions as well.
 337       if (!BD->isDependentContext()) {
 338         HandleCode(BD, RecVisitorMode);
 339       }
 340     }
 341     return true;
 342   }
 343
 344   void AddDiagnosticConsumer(PathDiagnosticConsumer *Consumer) override {
 345     PathConsumers.push_back(Consumer);
 346   }
 347
 348   void AddCheckerRegistrationFn(std::function<void(CheckerRegistry&)> Fn) override {
 349     CheckerRegistrationFns.push_back(std::move(Fn));
 350   }
 351
 352 private:
 353   void storeTopLevelDecls(DeclGroupRef DG);
 354
 355   /// Check if we should skip (not analyze) the given function.
 356   AnalysisMode getModeForDecl(Decl *D, AnalysisMode Mode);
 357   void runAnalysisOnTranslationUnit(ASTContext &C);
 358
 359   /// Print \p S to stderr if \c Opts.AnalyzerDisplayProgress is set.
 360   void reportAnalyzerProgress(StringRef S);
 361 }; // namespace
 362 } // end anonymous namespace
 363
 364
 365 //===----------------------------------------------------------------------===//
 366 // AnalysisConsumer implementation.
 367 //===----------------------------------------------------------------------===//
 368 bool AnalysisConsumer::HandleTopLevelDecl(DeclGroupRef DG) {
 369   storeTopLevelDecls(DG);
 370   return true;
 371 }
 372
 373 void AnalysisConsumer::HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) {
 374   storeTopLevelDecls(DG);
 375 }
 376
 377 void AnalysisConsumer::storeTopLevelDecls(DeclGroupRef DG) {
 378   for (auto &I : DG) {
 379
 380     // Skip ObjCMethodDecl, wait for the objc container to avoid
 381     // analyzing twice.
 382     if (isa<ObjCMethodDecl>(I))
 383       continue;
 384
 385     LocalTUDecls.push_back(I);
 386   }
 387 }
 388
 389 static bool shouldSkipFunction(const Decl *D,
 390                                const SetOfConstDecls &Visited,
 391                                const SetOfConstDecls &VisitedAsTopLevel) {
 392   if (VisitedAsTopLevel.count(D))
 393     return true;
 394
 395   // Skip analysis of inheriting constructors as top-level functions. These
 396   // constructors don't even have a body written down in the code, so even if
 397   // we find a bug, we won't be able to display it.
 398   if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
 399     if (CD->isInheritingConstructor())
 400       return true;
 401
 402   // We want to re-analyse the functions as top level in the following cases:
 403   // - The 'init' methods should be reanalyzed because
 404   //   ObjCNonNilReturnValueChecker assumes that '[super init]' never returns
 405   //   'nil' and unless we analyze the 'init' functions as top level, we will
 406   //   not catch errors within defensive code.
 407   // - We want to reanalyze all ObjC methods as top level to report Retain
 408   //   Count naming convention errors more aggressively.
 409   if (isa<ObjCMethodDecl>(D))
 410     return false;
 411   // We also want to reanalyze all C++ copy and move assignment operators to
 412   // separately check the two cases where 'this' aliases with the parameter and
 413   // where it may not. (cplusplus.SelfAssignmentChecker)
 414   if (const auto *MD = dyn_cast<CXXMethodDecl>(D)) {
 415     if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator())
 416       return false;
 417   }
 418
 419   // Otherwise, if we visited the function before, do not reanalyze it.
 420   return Visited.count(D);
 421 }
 422
 423 ExprEngine::InliningModes
 424 AnalysisConsumer::getInliningModeForFunction(const Decl *D,
 425                                              const SetOfConstDecls &Visited) {
 426   // We want to reanalyze all ObjC methods as top level to report Retain
 427   // Count naming convention errors more aggressively. But we should tune down
 428   // inlining when reanalyzing an already inlined function.
 429   if (Visited.count(D) && isa<ObjCMethodDecl>(D)) {
 430     const ObjCMethodDecl *ObjCM = cast<ObjCMethodDecl>(D);
 431     if (ObjCM->getMethodFamily() != OMF_init)
 432       return ExprEngine::Inline_Minimal;
 433   }
 434
 435   return ExprEngine::Inline_Regular;
 436 }
 437
 438 void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
 439   // Build the Call Graph by adding all the top level declarations to the graph.
 440   // Note: CallGraph can trigger deserialization of more items from a pch
 441   // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
 442   // We rely on random access to add the initially processed Decls to CG.
 443   CallGraph CG;
 444   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
 445     CG.addToCallGraph(LocalTUDecls[i]);
 446   }
 447
 448   // Walk over all of the call graph nodes in topological order, so that we
 449   // analyze parents before the children. Skip the functions inlined into
 450   // the previously processed functions. Use external Visited set to identify
 451   // inlined functions. The topological order allows the "do not reanalyze
 452   // previously inlined function" performance heuristic to be triggered more
 453   // often.
 454   SetOfConstDecls Visited;
 455   SetOfConstDecls VisitedAsTopLevel;
 456   llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
 457   for (auto &N : RPOT) {
 458     NumFunctionTopLevel++;
 459
 460     Decl *D = N->getDecl();
 461
 462     // Skip the abstract root node.
 463     if (!D)
 464       continue;
 465
 466     // Skip the functions which have been processed already or previously
 467     // inlined.
 468     if (shouldSkipFunction(D, Visited, VisitedAsTopLevel))
 469       continue;
 470
 471     // The CallGraph might have declarations as callees. However, during CTU
 472     // the declaration might form a declaration chain with the newly imported
 473     // definition from another TU. In this case we don't want to analyze the
 474     // function definition as toplevel.
 475     if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
 476       // Calling 'hasBody' replaces 'FD' in place with the FunctionDecl
 477       // that has the body.
 478       FD->hasBody(FD);
 479       if (CTU.isImportedAsNew(FD))
 480         continue;
 481     }
 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 static bool fileContainsString(StringRef Substring, ASTContext &C) {
 500   const SourceManager &SM = C.getSourceManager();
 501   FileID FID = SM.getMainFileID();
 502   StringRef Buffer = SM.getBufferOrFake(FID).getBuffer();
 503   return Buffer.contains(Substring);
 504 }
 505
 506 static void reportAnalyzerFunctionMisuse(const AnalyzerOptions &Opts,
 507                                          const ASTContext &Ctx) {
 508   llvm::errs() << "Every top-level function was skipped.\n";
 509
 510   if (!Opts.AnalyzerDisplayProgress)
 511     llvm::errs() << "Pass the -analyzer-display-progress for tracking which "
 512                     "functions are analyzed.\n";
 513
 514   bool HasBrackets =
 515       Opts.AnalyzeSpecificFunction.find("(") != std::string::npos;
 516
 517   if (Ctx.getLangOpts().CPlusPlus && !HasBrackets) {
 518     llvm::errs()
 519         << "For analyzing C++ code you need to pass the function parameter "
 520            "list: -analyze-function=\"foobar(int, _Bool)\"\n";
 521   } else if (!Ctx.getLangOpts().CPlusPlus && HasBrackets) {
 522     llvm::errs() << "For analyzing C code you shouldn't pass the function "
 523                     "parameter list, only the name of the function: "
 524                     "-analyze-function=foobar\n";
 525   }
 526 }
 527
 528 void AnalysisConsumer::runAnalysisOnTranslationUnit(ASTContext &C) {
 529   BugReporter BR(*Mgr);
 530   TranslationUnitDecl *TU = C.getTranslationUnitDecl();
 531   if (SyntaxCheckTimer)
 532     SyntaxCheckTimer->startTimer();
 533   checkerMgr->runCheckersOnASTDecl(TU, *Mgr, BR);
 534   if (SyntaxCheckTimer)
 535     SyntaxCheckTimer->stopTimer();
 536
 537   // Run the AST-only checks using the order in which functions are defined.
 538   // If inlining is not turned on, use the simplest function order for path
 539   // sensitive analyzes as well.
 540   RecVisitorMode = AM_Syntax;
 541   if (!Mgr->shouldInlineCall())
 542     RecVisitorMode |= AM_Path;
 543   RecVisitorBR = &BR;
 544
 545   // Process all the top level declarations.
 546   //
 547   // Note: TraverseDecl may modify LocalTUDecls, but only by appending more
 548   // entries.  Thus we don't use an iterator, but rely on LocalTUDecls
 549   // random access.  By doing so, we automatically compensate for iterators
 550   // possibly being invalidated, although this is a bit slower.
 551   const unsigned LocalTUDeclsSize = LocalTUDecls.size();
 552   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
 553     TraverseDecl(LocalTUDecls[i]);
 554   }
 555
 556   if (Mgr->shouldInlineCall())
 557     HandleDeclsCallGraph(LocalTUDeclsSize);
 558
 559   // After all decls handled, run checkers on the entire TranslationUnit.
 560   checkerMgr->runCheckersOnEndOfTranslationUnit(TU, *Mgr, BR);
 561
 562   BR.FlushReports();
 563   RecVisitorBR = nullptr;
 564
 565   // If the user wanted to analyze a specific function and the number of basic
 566   // blocks analyzed is zero, than the user might not specified the function
 567   // name correctly.
 568   // FIXME: The user might have analyzed the requested function in Syntax mode,
 569   // but we are unaware of that.
 570   if (!Opts.AnalyzeSpecificFunction.empty() && NumFunctionsAnalyzed == 0)
 571     reportAnalyzerFunctionMisuse(Opts, *Ctx);
 572 }
 573
 574 void AnalysisConsumer::reportAnalyzerProgress(StringRef S) {
 575   if (Opts.AnalyzerDisplayProgress)
 576     llvm::errs() << S;
 577 }
 578
 579 void AnalysisConsumer::HandleTranslationUnit(ASTContext &C) {
 580   // Don't run the actions if an error has occurred with parsing the file.
 581   DiagnosticsEngine &Diags = PP.getDiagnostics();
 582   if (Diags.hasErrorOccurred() || Diags.hasFatalErrorOccurred())
 583     return;
 584
 585   // Explicitly destroy the PathDiagnosticConsumer.  This will flush its output.
 586   // FIXME: This should be replaced with something that doesn't rely on
 587   // side-effects in PathDiagnosticConsumer's destructor. This is required when
 588   // used with option -disable-free.
 589   const auto DiagFlusherScopeExit =
 590       llvm::make_scope_exit([this] { Mgr.reset(); });
 591
 592   if (Opts.ShouldIgnoreBisonGeneratedFiles &&
 593       fileContainsString("/* A Bison parser, made by", C)) {
 594     reportAnalyzerProgress("Skipping bison-generated file\n");
 595     return;
 596   }
 597
 598   if (Opts.ShouldIgnoreFlexGeneratedFiles &&
 599       fileContainsString("/* A lexical scanner generated by flex", C)) {
 600     reportAnalyzerProgress("Skipping flex-generated file\n");
 601     return;
 602   }
 603
 604   // Don't analyze if the user explicitly asked for no checks to be performed
 605   // on this file.
 606   if (Opts.DisableAllCheckers) {
 607     reportAnalyzerProgress("All checks are disabled using a supplied option\n");
 608     return;
 609   }
 610
 611   // Otherwise, just run the analysis.
 612   runAnalysisOnTranslationUnit(C);
 613
 614   // Count how many basic blocks we have not covered.
 615   NumBlocksInAnalyzedFunctions = FunctionSummaries.getTotalNumBasicBlocks();
 616   NumVisitedBlocksInAnalyzedFunctions =
 617       FunctionSummaries.getTotalNumVisitedBasicBlocks();
 618   if (NumBlocksInAnalyzedFunctions > 0)
 619     PercentReachableBlocks =
 620         (FunctionSummaries.getTotalNumVisitedBasicBlocks() * 100) /
 621         NumBlocksInAnalyzedFunctions;
 622 }
 623
 624 AnalysisConsumer::AnalysisMode
 625 AnalysisConsumer::getModeForDecl(Decl *D, AnalysisMode Mode) {
 626   if (!Opts.AnalyzeSpecificFunction.empty() &&
 627       AnalysisDeclContext::getFunctionName(D) != Opts.AnalyzeSpecificFunction)
 628     return AM_None;
 629
 630   // Unless -analyze-all is specified, treat decls differently depending on
 631   // where they came from:
 632   // - Main source file: run both path-sensitive and non-path-sensitive checks.
 633   // - Header files: run non-path-sensitive checks only.
 634   // - System headers: don't run any checks.
 635   if (Opts.AnalyzeAll)
 636     return Mode;
 637
 638   const SourceManager &SM = Ctx->getSourceManager();
 639
 640   const SourceLocation Loc = [&SM](Decl *D) -> SourceLocation {
 641     const Stmt *Body = D->getBody();
 642     SourceLocation SL = Body ? Body->getBeginLoc() : D->getLocation();
 643     return SM.getExpansionLoc(SL);
 644   }(D);
 645
 646   // Ignore system headers.
 647   if (Loc.isInvalid() || SM.isInSystemHeader(Loc))
 648     return AM_None;
 649
 650   // Disable path sensitive analysis in user-headers.
 651   if (!Mgr->isInCodeFile(Loc))
 652     return Mode & ~AM_Path;
 653
 654   return Mode;
 655 }
 656
 657 void AnalysisConsumer::HandleCode(Decl *D, AnalysisMode Mode,
 658                                   ExprEngine::InliningModes IMode,
 659                                   SetOfConstDecls *VisitedCallees) {
 660   if (!D->hasBody())
 661     return;
 662   Mode = getModeForDecl(D, Mode);
 663   if (Mode == AM_None)
 664     return;
 665
 666   // Clear the AnalysisManager of old AnalysisDeclContexts.
 667   Mgr->ClearContexts();
 668   // Ignore autosynthesized code.
 669   if (Mgr->getAnalysisDeclContext(D)->isBodyAutosynthesized())
 670     return;
 671
 672   CFG *DeclCFG = Mgr->getCFG(D);
 673   if (DeclCFG)
 674     MaxCFGSize.updateMax(DeclCFG->size());
 675
 676   DisplayFunction(D, Mode, IMode);
 677   BugReporter BR(*Mgr);
 678
 679   if (Mode & AM_Syntax) {
 680     llvm::TimeRecord CheckerStartTime;
 681     if (SyntaxCheckTimer) {
 682       CheckerStartTime = SyntaxCheckTimer->getTotalTime();
 683       SyntaxCheckTimer->startTimer();
 684     }
 685     checkerMgr->runCheckersOnASTBody(D, *Mgr, BR);
 686     if (SyntaxCheckTimer) {
 687       SyntaxCheckTimer->stopTimer();
 688       llvm::TimeRecord CheckerEndTime = SyntaxCheckTimer->getTotalTime();
 689       CheckerEndTime -= CheckerStartTime;
 690       DisplayTime(CheckerEndTime);
 691     }
 692   }
 693
 694   BR.FlushReports();
 695
 696   if ((Mode & AM_Path) && checkerMgr->hasPathSensitiveCheckers()) {
 697     RunPathSensitiveChecks(D, IMode, VisitedCallees);
 698     if (IMode != ExprEngine::Inline_Minimal)
 699       NumFunctionsAnalyzed++;
 700   }
 701 }
 702
 703 //===----------------------------------------------------------------------===//
 704 // Path-sensitive checking.
 705 //===----------------------------------------------------------------------===//
 706
 707 void AnalysisConsumer::RunPathSensitiveChecks(Decl *D,
 708                                               ExprEngine::InliningModes IMode,
 709                                               SetOfConstDecls *VisitedCallees) {
 710   // Construct the analysis engine.  First check if the CFG is valid.
 711   // FIXME: Inter-procedural analysis will need to handle invalid CFGs.
 712   if (!Mgr->getCFG(D))
 713     return;
 714
 715   // See if the LiveVariables analysis scales.
 716   if (!Mgr->getAnalysisDeclContext(D)->getAnalysis<RelaxedLiveVariables>())
 717     return;
 718
 719   ExprEngine Eng(CTU, *Mgr, VisitedCallees, &FunctionSummaries, IMode);
 720
 721   // Execute the worklist algorithm.
 722   llvm::TimeRecord ExprEngineStartTime;
 723   if (ExprEngineTimer) {
 724     ExprEngineStartTime = ExprEngineTimer->getTotalTime();
 725     ExprEngineTimer->startTimer();
 726   }
 727   Eng.ExecuteWorkList(Mgr->getAnalysisDeclContextManager().getStackFrame(D),
 728                       Mgr->options.MaxNodesPerTopLevelFunction);
 729   if (ExprEngineTimer) {
 730     ExprEngineTimer->stopTimer();
 731     llvm::TimeRecord ExprEngineEndTime = ExprEngineTimer->getTotalTime();
 732     ExprEngineEndTime -= ExprEngineStartTime;
 733     DisplayTime(ExprEngineEndTime);
 734   }
 735
 736   if (!Mgr->options.DumpExplodedGraphTo.empty())
 737     Eng.DumpGraph(Mgr->options.TrimGraph, Mgr->options.DumpExplodedGraphTo);
 738
 739   // Visualize the exploded graph.
 740   if (Mgr->options.visualizeExplodedGraphWithGraphViz)
 741     Eng.ViewGraph(Mgr->options.TrimGraph);
 742
 743   // Display warnings.
 744   if (BugReporterTimer)
 745     BugReporterTimer->startTimer();
 746   Eng.getBugReporter().FlushReports();
 747   if (BugReporterTimer)
 748     BugReporterTimer->stopTimer();
 749 }
 750
 751 //===----------------------------------------------------------------------===//
 752 // AnalysisConsumer creation.
 753 //===----------------------------------------------------------------------===//
 754
 755 std::unique_ptr<AnalysisASTConsumer>
 756 ento::CreateAnalysisConsumer(CompilerInstance &CI) {
 757   // Disable the effects of '-Werror' when using the AnalysisConsumer.
 758   CI.getPreprocessor().getDiagnostics().setWarningsAsErrors(false);
 759
 760   AnalyzerOptions &analyzerOpts = CI.getAnalyzerOpts();
 761   bool hasModelPath = analyzerOpts.Config.count("model-path") > 0;
 762
 763   return std::make_unique<AnalysisConsumer>(
 764       CI, CI.getFrontendOpts().OutputFile, analyzerOpts,
 765       CI.getFrontendOpts().Plugins,
 766       hasModelPath ? new ModelInjector(CI) : nullptr);
 767 }