1 //==--AnalyzerStatsChecker.cpp - Analyzer visitation statistics --*- C++ -*-==// 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 // This file reports various statistics about analyzer visitation. 9 //===----------------------------------------------------------------------===// 10 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" 11 #include "clang/AST/DeclObjC.h" 12 #include "clang/Basic/SourceManager.h" 13 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 14 #include "clang/StaticAnalyzer/Core/Checker.h" 15 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 16 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h" 17 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 18 #include "llvm/ADT/SmallPtrSet.h" 19 #include "llvm/ADT/SmallString.h" 20 #include "llvm/ADT/Statistic.h" 21 #include "llvm/Support/raw_ostream.h" 22 23 using namespace clang; 24 using namespace ento; 25 26 #define DEBUG_TYPE "StatsChecker" 27 28 STATISTIC(NumBlocks, 29 "The # of blocks in top level functions"); 30 STATISTIC(NumBlocksUnreachable, 31 "The # of unreachable blocks in analyzing top level functions"); 32 33 namespace { 34 class AnalyzerStatsChecker : public Checker<check::EndAnalysis> { 35 public: 36 void checkEndAnalysis(ExplodedGraph &G, BugReporter &B,ExprEngine &Eng) const; 37 }; 38 } 39 40 void AnalyzerStatsChecker::checkEndAnalysis(ExplodedGraph &G, 41 BugReporter &B, 42 ExprEngine &Eng) const { 43 const CFG *C = nullptr; 44 const SourceManager &SM = B.getSourceManager(); 45 llvm::SmallPtrSet<const CFGBlock*, 32> reachable; 46 47 // Root node should have the location context of the top most function. 48 const ExplodedNode *GraphRoot = *G.roots_begin(); 49 const LocationContext *LC = GraphRoot->getLocation().getLocationContext(); 50 51 const Decl *D = LC->getDecl(); 52 53 // Iterate over the exploded graph. 54 for (ExplodedGraph::node_iterator I = G.nodes_begin(); 55 I != G.nodes_end(); ++I) { 56 const ProgramPoint &P = I->getLocation(); 57 58 // Only check the coverage in the top level function (optimization). 59 if (D != P.getLocationContext()->getDecl()) 60 continue; 61 62 if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 63 const CFGBlock *CB = BE->getBlock(); 64 reachable.insert(CB); 65 } 66 } 67 68 // Get the CFG and the Decl of this block. 69 C = LC->getCFG(); 70 71 unsigned total = 0, unreachable = 0; 72 73 // Find CFGBlocks that were not covered by any node 74 for (CFG::const_iterator I = C->begin(); I != C->end(); ++I) { 75 const CFGBlock *CB = *I; 76 ++total; 77 // Check if the block is unreachable 78 if (!reachable.count(CB)) { 79 ++unreachable; 80 } 81 } 82 83 // We never 'reach' the entry block, so correct the unreachable count 84 unreachable--; 85 // There is no BlockEntrance corresponding to the exit block as well, so 86 // assume it is reached as well. 87 unreachable--; 88 89 // Generate the warning string 90 SmallString<128> buf; 91 llvm::raw_svector_ostream output(buf); 92 PresumedLoc Loc = SM.getPresumedLoc(D->getLocation()); 93 if (!Loc.isValid()) 94 return; 95 96 if (isa<FunctionDecl>(D) || isa<ObjCMethodDecl>(D)) { 97 const NamedDecl *ND = cast<NamedDecl>(D); 98 output << *ND; 99 } 100 else if (isa<BlockDecl>(D)) { 101 output << "block(line:" << Loc.getLine() << ":col:" << Loc.getColumn(); 102 } 103 104 NumBlocksUnreachable += unreachable; 105 NumBlocks += total; 106 std::string NameOfRootFunction = std::string(output.str()); 107 108 output << " -> Total CFGBlocks: " << total << " | Unreachable CFGBlocks: " 109 << unreachable << " | Exhausted Block: " 110 << (Eng.wasBlocksExhausted() ? "yes" : "no") 111 << " | Empty WorkList: " 112 << (Eng.hasEmptyWorkList() ? "yes" : "no"); 113 114 B.EmitBasicReport(D, this, "Analyzer Statistics", "Internal Statistics", 115 output.str(), PathDiagnosticLocation(D, SM)); 116 117 // Emit warning for each block we bailed out on. 118 typedef CoreEngine::BlocksExhausted::const_iterator ExhaustedIterator; 119 const CoreEngine &CE = Eng.getCoreEngine(); 120 for (ExhaustedIterator I = CE.blocks_exhausted_begin(), 121 E = CE.blocks_exhausted_end(); I != E; ++I) { 122 const BlockEdge &BE = I->first; 123 const CFGBlock *Exit = BE.getDst(); 124 if (Exit->empty()) 125 continue; 126 const CFGElement &CE = Exit->front(); 127 if (Optional<CFGStmt> CS = CE.getAs<CFGStmt>()) { 128 SmallString<128> bufI; 129 llvm::raw_svector_ostream outputI(bufI); 130 outputI << "(" << NameOfRootFunction << ")" << 131 ": The analyzer generated a sink at this point"; 132 B.EmitBasicReport( 133 D, this, "Sink Point", "Internal Statistics", outputI.str(), 134 PathDiagnosticLocation::createBegin(CS->getStmt(), SM, LC)); 135 } 136 } 137 } 138 139 void ento::registerAnalyzerStatsChecker(CheckerManager &mgr) { 140 mgr.registerChecker<AnalyzerStatsChecker>(); 141 } 142 143 bool ento::shouldRegisterAnalyzerStatsChecker(const CheckerManager &mgr) { 144 return true; 145 } 146