lib/VMCore/LeaksContext.h

   1 //===- LeaksContext.h - LeadDetector Implementation ------------*- 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 //
  10 //  This file defines various helper methods and classes used by
  11 // LLVMContextImpl for leaks detectors.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Value.h"
  16 #include "llvm/ADT/SmallPtrSet.h"
  17
  18 namespace llvm {
  19
  20 template <class T>
  21 struct PrinterTrait {
  22   static void print(const T* P) { errs() << P; }
  23 };
  24
  25 template<>
  26 struct PrinterTrait<Value> {
  27   static void print(const Value* P) { errs() << *P; }
  28 };
  29
  30 template <typename T>
  31 struct LeakDetectorImpl {
  32   explicit LeakDetectorImpl(const char* const name = "") :
  33     Cache(0), Name(name) { }
  34
  35   void clear() {
  36     Cache = 0;
  37     Ts.clear();
  38   }
  39
  40   void setName(const char* n) {
  41     Name = n;
  42   }
  43
  44   // Because the most common usage pattern, by far, is to add a
  45   // garbage object, then remove it immediately, we optimize this
  46   // case.  When an object is added, it is not added to the set
  47   // immediately, it is added to the CachedValue Value.  If it is
  48   // immediately removed, no set search need be performed.
  49   void addGarbage(const T* o) {
  50     assert(Ts.count(o) == 0 && "Object already in set!");
  51     if (Cache) {
  52       assert(Cache != o && "Object already in set!");
  53       Ts.insert(Cache);
  54     }
  55     Cache = o;
  56   }
  57
  58   void removeGarbage(const T* o) {
  59     if (o == Cache)
  60       Cache = 0; // Cache hit
  61     else
  62       Ts.erase(o);
  63   }
  64
  65   bool hasGarbage(const std::string& Message) {
  66     addGarbage(0); // Flush the Cache
  67
  68     assert(Cache == 0 && "No value should be cached anymore!");
  69
  70     if (!Ts.empty()) {
  71       errs() << "Leaked " << Name << " objects found: " << Message << ":\n";
  72       for (typename SmallPtrSet<const T*, 8>::iterator I = Ts.begin(),
  73            E = Ts.end(); I != E; ++I) {
  74         errs() << '\t';
  75         PrinterTrait<T>::print(*I);
  76         errs() << '\n';
  77       }
  78       errs() << '\n';
  79
  80       return true;
  81     }
  82
  83     return false;
  84   }
  85
  86 private:
  87   SmallPtrSet<const T*, 8> Ts;
  88   const T* Cache;
  89   const char* Name;
  90 };
  91
  92 }