src/llvm/lib/IR/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 #ifndef LLVM_LIB_IR_LEAKSCONTEXT_H
  16 #define LLVM_LIB_IR_LEAKSCONTEXT_H
  17
  18 #include "llvm/ADT/SmallPtrSet.h"
  19 #include "llvm/IR/Metadata.h"
  20 #include "llvm/IR/Value.h"
  21 #include "llvm/Support/raw_ostream.h"
  22
  23 namespace llvm {
  24
  25 template <class T>
  26 struct PrinterTrait {
  27   static void print(const T* P) { errs() << P; }
  28 };
  29
  30 template<>
  31 struct PrinterTrait<Value> {
  32   static void print(const Value* P) { errs() << *P; }
  33 };
  34
  35 template <> struct PrinterTrait<Metadata> {
  36   static void print(const Metadata *P) { P->print(errs()); }
  37 };
  38
  39 template <typename T>
  40 struct LeakDetectorImpl {
  41   explicit LeakDetectorImpl(const char* const name = "") :
  42     Cache(nullptr), Name(name) { }
  43
  44   void clear() {
  45     Cache = nullptr;
  46     Ts.clear();
  47   }
  48
  49   void setName(const char* n) {
  50     Name = n;
  51   }
  52
  53   // Because the most common usage pattern, by far, is to add a
  54   // garbage object, then remove it immediately, we optimize this
  55   // case.  When an object is added, it is not added to the set
  56   // immediately, it is added to the CachedValue Value.  If it is
  57   // immediately removed, no set search need be performed.
  58   void addGarbage(const T* o) {
  59     assert(Ts.count(o) == 0 && "Object already in set!");
  60     if (Cache) {
  61       assert(Cache != o && "Object already in set!");
  62       Ts.insert(Cache);
  63     }
  64     Cache = o;
  65   }
  66
  67   void removeGarbage(const T* o) {
  68     if (o == Cache)
  69       Cache = nullptr; // Cache hit
  70     else
  71       Ts.erase(o);
  72   }
  73
  74   bool hasGarbage(const std::string& Message) {
  75     addGarbage(nullptr); // Flush the Cache
  76
  77     assert(!Cache && "No value should be cached anymore!");
  78
  79     if (!Ts.empty()) {
  80       errs() << "Leaked " << Name << " objects found: " << Message << ":\n";
  81       for (typename SmallPtrSet<const T*, 8>::iterator I = Ts.begin(),
  82            E = Ts.end(); I != E; ++I) {
  83         errs() << '\t';
  84         PrinterTrait<T>::print(*I);
  85         errs() << '\n';
  86       }
  87       errs() << '\n';
  88
  89       return true;
  90     }
  91
  92     return false;
  93   }
  94
  95 private:
  96   SmallPtrSet<const T*, 8> Ts;
  97   const T* Cache;
  98   const char* Name;
  99 };
 100
 101 }
 102
 103 #endif