LeakDetector.cpp revision ce36d55cf8d3239942e0e9c426c835f0c33a11e6 
1//===-- LeakDetector.cpp - Implement LeakDetector interface ---------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the LeakDetector class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "Support/LeakDetector.h"
15#include "llvm/Value.h"
16#include <iostream>
17#include <set>
18using namespace llvm;
19
20namespace {
21  template <class T>
22  struct PrinterTrait {
23    static void print(const T* P) { std::cerr << P; }
24  };
25
26  template<>
27  struct PrinterTrait<Value> {
28    static void print(const Value* P) { std::cerr << *P; }
29  };
30
31  template <typename T>
32  struct LeakDetectorImpl {
33    LeakDetectorImpl(const char* const name) : Cache(0), Name(name) { }
34
35    // Because the most common usage pattern, by far, is to add a
36    // garbage object, then remove it immediately, we optimize this
37    // case.  When an object is added, it is not added to the set
38    // immediately, it is added to the CachedValue Value.  If it is
39    // immediately removed, no set search need be performed.
40    void addGarbage(const T* o) {
41      if (Cache) {
42        assert(Ts.count(Cache) == 0 && "Object already in set!");
43        Ts.insert(Cache);
44      }
45      Cache = o;
46    }
47
48    void removeGarbage(const T* o) {
49      if (o == Cache)
50        Cache = 0; // Cache hit
51      else
52        Ts.erase(o);
53    }
54
55    bool hasGarbage(const std::string& Message) {
56      addGarbage(0); // Flush the Cache
57
58      assert(Cache == 0 && "No value should be cached anymore!");
59
60      if (!Ts.empty()) {
61        std::cerr
62            << "Leaked " << Name << " objects found: " << Message << ":\n";
63        for (typename std::set<const T*>::iterator I = Ts.begin(),
64               E = Ts.end(); I != E; ++I) {
65          std::cerr << "\t";
66          PrinterTrait<T>::print(*I);
67          std::cerr << "\n";
68        }
69        std::cerr << '\n';
70
71        // Clear out results so we don't get duplicate warnings on
72        // next call...
73        Ts.clear();
74        return true;
75      }
76      return false;
77    }
78
79  private:
80    std::set<const T*> Ts;
81    const T* Cache;
82    const char* const Name;
83  };
84
85  typedef LeakDetectorImpl<void>  Objects;
86  typedef LeakDetectorImpl<Value> LLVMObjects;
87
88  Objects& getObjects() {
89    static Objects *o = 0;
90    if (o == 0)
91      o = new Objects("GENERIC");
92    return *o;
93  }
94
95  LLVMObjects& getLLVMObjects() {
96    static LLVMObjects *o = 0;
97    if (o == 0)
98      o = new LLVMObjects("LLVM");
99    return *o;
100  }
101}
102
103void LeakDetector::addGarbageObjectImpl(void *Object) {
104  getObjects().addGarbage(Object);
105}
106
107void LeakDetector::addGarbageObjectImpl(const Value *Object) {
108  getLLVMObjects().addGarbage(Object);
109}
110
111void LeakDetector::removeGarbageObjectImpl(void *Object) {
112  getObjects().removeGarbage(Object);
113}
114
115void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
116  getLLVMObjects().removeGarbage(Object);
117}
118
119void LeakDetector::checkForGarbageImpl(const std::string &Message) {
120  // use non-short-circuit version so that both checks are performed
121  if (getObjects().hasGarbage(Message) |
122      getLLVMObjects().hasGarbage(Message))
123    std::cerr << "\nThis is probably because you removed an object, but didn't "
124                 "delete it.  Please check your code for memory leaks.\n";
125}
126