/*

    File:   main.cpp

    Version:    1.0

    Abstract: Overrides the C++ 'operator new' and 'operator delete'.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

        ("Apple") in consideration of your agreement to the following terms, and your

        use, installation, modification or redistribution of this Apple software

        constitutes acceptance of these terms.  If you do not agree with these terms,

        please do not use, install, modify or redistribute this Apple software.

        In consideration of your agreement to abide by the following terms, and subject

        to these terms, Apple grants you a personal, non-exclusive license, under Apple’s

        copyrights in this original Apple software (the "Apple Software"), to use,

        reproduce, modify and redistribute the Apple Software, with or without

        modifications, in source and/or binary forms; provided that if you redistribute

        the Apple Software in its entirety and without modifications, you must retain

        this notice and the following text and disclaimers in all such redistributions of

        the Apple Software.  Neither the name, trademarks, service marks or logos of

        Apple Computer, Inc. may be used to endorse or promote products derived from the

        Apple Software without specific prior written permission from Apple.  Except as

        expressly stated in this notice, no other rights or licenses, express or implied,

        are granted by Apple herein, including but not limited to any patent rights that

        may be infringed by your derivative works or by other works in which the Apple

        Software may be incorporated.

        The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

        WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

        WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR

        PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN

        COMBINATION WITH YOUR PRODUCTS.

        IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR

        CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

        GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

        ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION

        OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT

        (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN

        ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    Copyright © 2006 Apple Computer, Inc., All Rights Reserved

*/

/* This sample shows how to override the C++ global 'new' and 'delete' operators.  */

#include <new>

#include <iostream>

#include <cstdlib>

#include <stdexcept>

#include <locale>

/* Some variables and code to make the example do something.  */

namespace {

  unsigned long long gNewCounter; // number of times 'new' was called

  unsigned long long gDeleteCounter;  // number of times 'delete' was called

  void printCounters()  // print the counters above

  {

    std::cout << "new was called " << gNewCounter << " times and delete was called " << gDeleteCounter << " times\n";

  }

}

/* These are the overridden new and delete routines.

   Most applications will want to override at least these four versions of new/delete if they override any of them.

   In Mac OS, it's not necessary to override the array versions of operator new and delete if all

   they would do is call the non-array versions; the C++ standard library, as an extension

   to the C++ standard, does this for you.

   Developers should consult the section [lib.support.dynamic] in the C++ standard to see the requirements

   on the generic operators new and delete; the system may expect that your overridden operators meet all these

   requirements.

   Your operators may be called by the system, even early in start-up before constructors have been executed.  */

void* operator new(std::size_t sz) throw (std::bad_alloc)

{

    void *result = std::malloc (sz == 0 ? 1 : sz);

    if (result == NULL)

        throw std::bad_alloc();

    gNewCounter++;

    return result;

}

void operator delete(void* p) throw()

{

    if (p == NULL)

        return;

    std::free (p);

    gDeleteCounter++;

}

/* These are the 'nothrow' versions of the above operators.

   The system version will try to call a std::new_handler if they

   fail, but your overriding versions are not required to do this.  */

void* operator new(std::size_t sz, const std::nothrow_t&) throw()

{

    try {

        void * result = ::operator new (sz);  // calls our overridden operator new

        return result;

    } catch (std::bad_alloc &) {

      return NULL;

    }

}

void operator delete(void* p, const std::nothrow_t&) throw()

{

    ::operator delete (p);

}

/* Bug 4067110 is that if your program has no weak symbols at all, the linker will not set the

   WEAK_DEFINES bit in the Mach-O header and as a result the new and delete operators above won't

   be seen by system libraries.  This is mostly a problem for test programs and small examples,

   since almost all real C++ programs complicated enough to override new and delete will have at

   least one weak symbol.  However, this is a small example, so:  */

void __attribute__((weak, visibility("default"))) workaroundFor4067110 () { }

/* This is a simple test program that causes the runtime library to call new and delete.  */

int main() 

{

    atexit (printCounters);

    try {

      std::locale example("does_not_exist");

    } catch (std::runtime_error &x) {

    }

    return 0;

}