AnalyzerStatsChecker.cpp revision 64394e2cc57d597eafe980bd94b060e2967a1cbd 
1//==--AnalyzerStatsChecker.cpp - Analyzer visitation statistics --*- C++ -*-==//
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// This file reports various statistics about analyzer visitation.
10//===----------------------------------------------------------------------===//
11
12#include "ClangSACheckers.h"
13#include "clang/StaticAnalyzer/Core/Checker.h"
14#include "clang/StaticAnalyzer/Core/CheckerManager.h"
15#include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
16#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
17#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
18
19#include "clang/AST/DeclObjC.h"
20#include "clang/Basic/SourceManager.h"
21#include "llvm/ADT/SmallPtrSet.h"
22#include "llvm/ADT/SmallString.h"
23
24using namespace clang;
25using namespace ento;
26
27namespace {
28class AnalyzerStatsChecker : public Checker<check::EndAnalysis> {
29public:
30  void checkEndAnalysis(ExplodedGraph &G, BugReporter &B,ExprEngine &Eng) const;
31};
32}
33
34void AnalyzerStatsChecker::checkEndAnalysis(ExplodedGraph &G,
35                                            BugReporter &B,
36                                            ExprEngine &Eng) const {
37  const CFG *C  = 0;
38  const Decl *D = 0;
39  const SourceManager &SM = B.getSourceManager();
40  llvm::SmallPtrSet<const CFGBlock*, 256> reachable;
41
42  // Root node should have the location context of the top most function.
43  const ExplodedNode *GraphRoot = *G.roots_begin();
44  const LocationContext *LC = GraphRoot->getLocation().getLocationContext();
45
46  // Iterate over the exploded graph.
47  for (ExplodedGraph::node_iterator I = G.nodes_begin();
48      I != G.nodes_end(); ++I) {
49    const ProgramPoint &P = I->getLocation();
50
51    // Only check the coverage in the top level function.
52    if (LC != P.getLocationContext())
53      continue;
54
55    if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) {
56      const CFGBlock *CB = BE->getBlock();
57      reachable.insert(CB);
58    }
59  }
60
61  // Get the CFG and the Decl of this block
62  C = LC->getCFG();
63  D = LC->getAnalysisDeclContext()->getDecl();
64
65  unsigned total = 0, unreachable = 0;
66
67  // Find CFGBlocks that were not covered by any node
68  for (CFG::const_iterator I = C->begin(); I != C->end(); ++I) {
69    const CFGBlock *CB = *I;
70    ++total;
71    // Check if the block is unreachable
72    if (!reachable.count(CB)) {
73      ++unreachable;
74    }
75  }
76
77  // We never 'reach' the entry block, so correct the unreachable count
78  unreachable--;
79  // There is no BlockEntrance corresponding to the exit block as well, so
80  // assume it is reached as well.
81  unreachable--;
82
83  // Generate the warning string
84  SmallString<128> buf;
85  llvm::raw_svector_ostream output(buf);
86  PresumedLoc Loc = SM.getPresumedLoc(D->getLocation());
87  if (Loc.isValid()) {
88    output << Loc.getFilename() << " : ";
89
90    if (isa<FunctionDecl>(D) || isa<ObjCMethodDecl>(D)) {
91      const NamedDecl *ND = cast<NamedDecl>(D);
92      output << *ND;
93    }
94    else if (isa<BlockDecl>(D)) {
95      output << "block(line:" << Loc.getLine() << ":col:" << Loc.getColumn();
96    }
97  }
98
99  output << " -> Total CFGBlocks: " << total << " | Unreachable CFGBlocks: "
100      << unreachable << " | Exhausted Block: "
101      << (Eng.wasBlocksExhausted() ? "yes" : "no")
102      << " | Empty WorkList: "
103      << (Eng.hasEmptyWorkList() ? "yes" : "no");
104
105  B.EmitBasicReport("Analyzer Statistics", "Internal Statistics", output.str(),
106      PathDiagnosticLocation(D, SM));
107
108  // Emit warning for each block we bailed out on
109  typedef CoreEngine::BlocksExhausted::const_iterator ExhaustedIterator;
110  const CoreEngine &CE = Eng.getCoreEngine();
111  for (ExhaustedIterator I = CE.blocks_exhausted_begin(),
112      E = CE.blocks_exhausted_end(); I != E; ++I) {
113    const BlockEdge &BE =  I->first;
114    const CFGBlock *Exit = BE.getDst();
115    const CFGElement &CE = Exit->front();
116    if (const CFGStmt *CS = dyn_cast<CFGStmt>(&CE))
117      B.EmitBasicReport("Bailout Point", "Internal Statistics", "The analyzer "
118          "stopped analyzing at this point",
119          PathDiagnosticLocation::createBegin(CS->getStmt(), SM, LC));
120  }
121}
122
123void ento::registerAnalyzerStatsChecker(CheckerManager &mgr) {
124  mgr.registerChecker<AnalyzerStatsChecker>();
125}
126