AnalyzerStatsChecker.cpp revision 07189521a15d9c088216b943649cb9fe231cbb57 
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#define DEBUG_TYPE "StatsChecker"
12
13#include "ClangSACheckers.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 "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
19
20#include "clang/AST/DeclObjC.h"
21#include "clang/Basic/SourceManager.h"
22#include "llvm/ADT/SmallPtrSet.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/ADT/Statistic.h"
25
26using namespace clang;
27using namespace ento;
28
29STATISTIC(NumBlocks,
30          "The # of blocks in top level functions");
31STATISTIC(NumBlocksUnreachable,
32          "The # of unreachable blocks in analyzing top level functions");
33
34namespace {
35class AnalyzerStatsChecker : public Checker<check::EndAnalysis> {
36public:
37  void checkEndAnalysis(ExplodedGraph &G, BugReporter &B,ExprEngine &Eng) const;
38};
39}
40
41void AnalyzerStatsChecker::checkEndAnalysis(ExplodedGraph &G,
42                                            BugReporter &B,
43                                            ExprEngine &Eng) const {
44  const CFG *C  = 0;
45  const SourceManager &SM = B.getSourceManager();
46  llvm::SmallPtrSet<const CFGBlock*, 256> reachable;
47
48  // Root node should have the location context of the top most function.
49  const ExplodedNode *GraphRoot = *G.roots_begin();
50  const LocationContext *LC = GraphRoot->getLocation().getLocationContext();
51
52  const Decl *D = LC->getDecl();
53
54  // Iterate over the exploded graph.
55  for (ExplodedGraph::node_iterator I = G.nodes_begin();
56      I != G.nodes_end(); ++I) {
57    const ProgramPoint &P = I->getLocation();
58
59    // Only check the coverage in the top level function (optimization).
60    if (D != P.getLocationContext()->getDecl())
61      continue;
62
63    if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) {
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>(D) || isa<ObjCMethodDecl>(D)) {
98    const NamedDecl *ND = cast<NamedDecl>(D);
99    output << *ND;
100  }
101  else if (isa<BlockDecl>(D)) {
102    output << "block(line:" << Loc.getLine() << ":col:" << Loc.getColumn();
103  }
104
105  NumBlocksUnreachable += unreachable;
106  NumBlocks += total;
107  std::string NameOfRootFunction = output.str();
108
109  output << " -> Total CFGBlocks: " << total << " | Unreachable CFGBlocks: "
110      << unreachable << " | Exhausted Block: "
111      << (Eng.wasBlocksExhausted() ? "yes" : "no")
112      << " | Empty WorkList: "
113      << (Eng.hasEmptyWorkList() ? "yes" : "no");
114
115  B.EmitBasicReport(D, "Analyzer Statistics", "Internal Statistics",
116                    output.str(), PathDiagnosticLocation(D, SM));
117
118  // Emit warning for each block we bailed out on.
119  typedef CoreEngine::BlocksExhausted::const_iterator ExhaustedIterator;
120  const CoreEngine &CE = Eng.getCoreEngine();
121  for (ExhaustedIterator I = CE.blocks_exhausted_begin(),
122      E = CE.blocks_exhausted_end(); I != E; ++I) {
123    const BlockEdge &BE =  I->first;
124    const CFGBlock *Exit = BE.getDst();
125    const CFGElement &CE = Exit->front();
126    if (const CFGStmt *CS = dyn_cast<CFGStmt>(&CE)) {
127      SmallString<128> bufI;
128      llvm::raw_svector_ostream outputI(bufI);
129      outputI << "(" << NameOfRootFunction << ")" <<
130                 ": The analyzer generated a sink at this point";
131      B.EmitBasicReport(D, "Sink Point", "Internal Statistics", outputI.str(),
132                        PathDiagnosticLocation::createBegin(CS->getStmt(),
133                                                            SM, LC));
134    }
135  }
136}
137
138void ento::registerAnalyzerStatsChecker(CheckerManager &mgr) {
139  mgr.registerChecker<AnalyzerStatsChecker>();
140}
141