lib/VMCore/LeakDetector.cpp

   1 //===-- LeakDetector.cpp - Implement LeakDetector interface ---------------===//
   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 //
  10 // This file implements the LeakDetector class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Support/LeakDetector.h"
  15 #include "llvm/ADT/SmallPtrSet.h"
  16 #include "llvm/Support/Compiler.h"
  17 #include "llvm/Support/Streams.h"
  18 #include "llvm/Value.h"
  19 using namespace llvm;
  20
  21 namespace {
  22   template <class T>
  23   struct VISIBILITY_HIDDEN PrinterTrait {
  24     static void print(const T* P) { cerr << P; }
  25   };
  26
  27   template<>
  28   struct VISIBILITY_HIDDEN PrinterTrait<Value> {
  29     static void print(const Value* P) { cerr << *P; }
  30   };
  31
  32   template <typename T>
  33   struct VISIBILITY_HIDDEN LeakDetectorImpl {
  34     explicit LeakDetectorImpl(const char* const name) : Cache(0), Name(name) { }
  35
  36     // Because the most common usage pattern, by far, is to add a
  37     // garbage object, then remove it immediately, we optimize this
  38     // case.  When an object is added, it is not added to the set
  39     // immediately, it is added to the CachedValue Value.  If it is
  40     // immediately removed, no set search need be performed.
  41     void addGarbage(const T* o) {
  42       if (Cache) {
  43         assert(Ts.count(Cache) == 0 && "Object already in set!");
  44         Ts.insert(Cache);
  45       }
  46       Cache = o;
  47     }
  48
  49     void removeGarbage(const T* o) {
  50       if (o == Cache)
  51         Cache = 0; // Cache hit
  52       else
  53         Ts.erase(o);
  54     }
  55
  56     bool hasGarbage(const std::string& Message) {
  57       addGarbage(0); // Flush the Cache
  58
  59       assert(Cache == 0 && "No value should be cached anymore!");
  60
  61       if (!Ts.empty()) {
  62         cerr << "Leaked " << Name << " objects found: " << Message << ":\n";
  63         for (typename SmallPtrSet<const T*, 8>::iterator I = Ts.begin(),
  64                E = Ts.end(); I != E; ++I) {
  65           cerr << "\t";
  66           PrinterTrait<T>::print(*I);
  67           cerr << "\n";
  68         }
  69         cerr << '\n';
  70
  71         return true;
  72       }
  73       return false;
  74     }
  75
  76   private:
  77     SmallPtrSet<const T*, 8> Ts;
  78     const T* Cache;
  79     const char* const Name;
  80   };
  81
  82   static LeakDetectorImpl<void>  *Objects;
  83   static LeakDetectorImpl<Value> *LLVMObjects;
  84
  85   static LeakDetectorImpl<void> &getObjects() {
  86     if (Objects == 0)
  87       Objects = new LeakDetectorImpl<void>("GENERIC");
  88     return *Objects;
  89   }
  90
  91   static LeakDetectorImpl<Value> &getLLVMObjects() {
  92     if (LLVMObjects == 0)
  93       LLVMObjects = new LeakDetectorImpl<Value>("LLVM");
  94     return *LLVMObjects;
  95   }
  96
  97   static void clearGarbage() {
  98     delete Objects;
  99     delete LLVMObjects;
 100     Objects = 0;
 101     LLVMObjects = 0;
 102   }
 103 }
 104
 105 void LeakDetector::addGarbageObjectImpl(void *Object) {
 106   getObjects().addGarbage(Object);
 107 }
 108
 109 void LeakDetector::addGarbageObjectImpl(const Value *Object) {
 110   getLLVMObjects().addGarbage(Object);
 111 }
 112
 113 void LeakDetector::removeGarbageObjectImpl(void *Object) {
 114   getObjects().removeGarbage(Object);
 115 }
 116
 117 void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
 118   getLLVMObjects().removeGarbage(Object);
 119 }
 120
 121 void LeakDetector::checkForGarbageImpl(const std::string &Message) {
 122   // use non-short-circuit version so that both checks are performed
 123   if (getObjects().hasGarbage(Message) |
 124       getLLVMObjects().hasGarbage(Message))
 125     cerr << "\nThis is probably because you removed an object, but didn't "
 126          << "delete it.  Please check your code for memory leaks.\n";
 127
 128   // Clear out results so we don't get duplicate warnings on
 129   // next call...
 130   clearGarbage();
 131 }