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/AST/DeclObjC.h" 11 #include "clang/Basic/SourceManager.h" 12 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.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/STLExtras.h" 19 #include "llvm/ADT/SmallPtrSet.h" 20 #include "llvm/ADT/SmallString.h" 21 #include "llvm/ADT/Statistic.h" 22 #include "llvm/Support/raw_ostream.h" 23 #include <optional> 24 25 using namespace clang; 26 using namespace ento; 27 28 #define DEBUG_TYPE "StatsChecker" 29 30 STATISTIC(NumBlocks, 31 "The # of blocks in top level functions"); 32 STATISTIC(NumBlocksUnreachable, 33 "The # of unreachable blocks in analyzing top level functions"); 34 35 namespace { 36 class AnalyzerStatsChecker : public Checker<check::EndAnalysis> { 37 public: 38 void checkEndAnalysis(ExplodedGraph &G, BugReporter &B,ExprEngine &Eng) const; 39 }; 40 } 41 42 void AnalyzerStatsChecker::checkEndAnalysis(ExplodedGraph &G, 43 BugReporter &B, 44 ExprEngine &Eng) const { 45 const CFG *C = nullptr; 46 const SourceManager &SM = B.getSourceManager(); 47 llvm::SmallPtrSet<const CFGBlock*, 32> reachable; 48 49 // Root node should have the location context of the top most function. 50 const ExplodedNode *GraphRoot = *G.roots_begin(); 51 const LocationContext *LC = GraphRoot->getLocation().getLocationContext(); 52 53 const Decl *D = LC->getDecl(); 54 55 // Iterate over the exploded graph. 56 for (const ExplodedNode &N : G.nodes()) { 57 const ProgramPoint &P = N.getLocation(); 58 59 // Only check the coverage in the top level function (optimization). 60 if (D != P.getLocationContext()->getDecl()) 61 continue; 62 63 if (std::optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 64 const CFGBlock *CB = BE->getBlock(); 65 reachable.insert(CB); 66 } 67 } 68 69 // Get the CFG and the Decl of this block. 70 C = LC->getCFG(); 71 72 unsigned total = 0, unreachable = 0; 73 74 // Find CFGBlocks that were not covered by any node 75 for (CFG::const_iterator I = C->begin(); I != C->end(); ++I) { 76 const CFGBlock *CB = *I; 77 ++total; 78 // Check if the block is unreachable 79 if (!reachable.count(CB)) { 80 ++unreachable; 81 } 82 } 83 84 // We never 'reach' the entry block, so correct the unreachable count 85 unreachable--; 86 // There is no BlockEntrance corresponding to the exit block as well, so 87 // assume it is reached as well. 88 unreachable--; 89 90 // Generate the warning string 91 SmallString<128> buf; 92 llvm::raw_svector_ostream output(buf); 93 PresumedLoc Loc = SM.getPresumedLoc(D->getLocation()); 94 if (!Loc.isValid()) 95 return; 96 97 if (isa<FunctionDecl, ObjCMethodDecl>(D)) { 98 const NamedDecl *ND = cast<NamedDecl>(D); 99 output << *ND; 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 const CoreEngine &CE = Eng.getCoreEngine(); 119 for (const BlockEdge &BE : make_first_range(CE.exhausted_blocks())) { 120 const CFGBlock *Exit = BE.getDst(); 121 if (Exit->empty()) 122 continue; 123 const CFGElement &CE = Exit->front(); 124 if (std::optional<CFGStmt> CS = CE.getAs<CFGStmt>()) { 125 SmallString<128> bufI; 126 llvm::raw_svector_ostream outputI(bufI); 127 outputI << "(" << NameOfRootFunction << ")" << 128 ": The analyzer generated a sink at this point"; 129 B.EmitBasicReport( 130 D, this, "Sink Point", "Internal Statistics", outputI.str(), 131 PathDiagnosticLocation::createBegin(CS->getStmt(), SM, LC)); 132 } 133 } 134 } 135 136 void ento::registerAnalyzerStatsChecker(CheckerManager &mgr) { 137 mgr.registerChecker<AnalyzerStatsChecker>(); 138 } 139 140 bool ento::shouldRegisterAnalyzerStatsChecker(const CheckerManager &mgr) { 141 return true; 142 } 143