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