//===-- Support/LeakDetector.h - Provide simple leak detection --*- C++ -*-===//
// 
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// 
//===----------------------------------------------------------------------===//
//
// This file defines a class that can be used to provide very simple memory leak
// checks for an API.  Basically LLVM uses this to make sure that Instructions,
// for example, are deleted when they are supposed to be, and not leaked away.
//
// When compiling with NDEBUG (Release build), this class does nothing, thus
// adding no checking overhead to release builds.  Note that this class is
// implemented in a very simple way, requiring completely manual manipulation
// and checking for garbage, but this is intentional: users should not be using
// this API, only other APIs should.
//
//===----------------------------------------------------------------------===//

#ifndef SUPPORT_LEAKDETECTOR_H
#define SUPPORT_LEAKDETECTOR_H

#include <string>
class Value;

struct LeakDetector {
  /// addGarbageObject - Add a pointer to the internal set of "garbage" object
  /// pointers.  This should be called when objects are created, or if they are
  /// taken out of an owning collection.
  ///
  static void addGarbageObject(void *Object) {
#ifndef NDEBUG
    addGarbageObjectImpl(Object);
#endif
  }

  /// removeGarbageObject - Remove a pointer from our internal representation of
  /// our "garbage" objects.  This should be called when an object is added to
  /// an "owning" collection.
  ///
  static void removeGarbageObject(void *Object) {
#ifndef NDEBUG
    removeGarbageObjectImpl(Object);
#endif
  }
  
  /// checkForGarbage - Traverse the internal representation of garbage
  /// pointers.  If there are any pointers that have been add'ed, but not
  /// remove'd, big obnoxious warnings about memory leaks are issued.
  ///
  /// The specified message will be printed indicating when the check was
  /// performed.
  ///
  static void checkForGarbage(const std::string &Message) {
#ifndef NDEBUG
    checkForGarbageImpl(Message);
#endif
  }

  /// Overload the normal methods to work better with Value*'s because they are
  /// by far the most common in LLVM.  This does not affect the actual
  /// functioning of this class, it just makes the warning messages nicer.
  ///
  static void addGarbageObject(const Value *Object) {
#ifndef NDEBUG
    addGarbageObjectImpl(Object);
#endif
  }
  static void removeGarbageObject(const Value *Object) {
#ifndef NDEBUG
    removeGarbageObjectImpl(Object);
#endif
  }

private:
  // If we are debugging, the actual implementations will be called...
  static void addGarbageObjectImpl(const Value *Object);
  static void removeGarbageObjectImpl(const Value *Object);
  static void addGarbageObjectImpl(void *Object);
  static void removeGarbageObjectImpl(void *Object);
  static void checkForGarbageImpl(const std::string &Message);
};

#endif
