gecko-dev/memory/mozalloc/mozalloc_abort.cpp
Rafael Ávila de Espíndola 2f6db18989 Bug 657528 - Use a volatile pointer to force a trap; r=ehsan
Clang issues the warning:
mozalloc_abort.cpp:64:22: warning: indirection of non-volatile null pointer will be deleted, not trap [-Wnull-dereference]

And sure enough, TouchBadMemory is currently broken with clang. That breaks mozalloc_abort
which breaks NS_DebugBreak which breaks the crashreport test.
2011-05-16 21:07:06 -04:00

91 lines
2.9 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: sw=4 ts=4 et :
*/
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Code
*
* The Initial Developer of the Original Code is
* The Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Jones <jones.chris.g@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <stdio.h>
#include <stdlib.h> // for abort()
#if defined(_MSC_VER) // MSVC
# include <intrin.h> // for __debugbreak()
#elif defined(XP_WIN) // mingw
# include <windows.h> // for DebugBreak
#elif defined(XP_UNIX)
# include <unistd.h> // for _exit
#endif
#if defined(XP_WIN) || defined(XP_OS2)
# define MOZALLOC_EXPORT __declspec(dllexport)
#endif
#include "mozilla/mozalloc_abort.h"
static int gDummyCounter;
static void
TouchBadMemory()
{
// XXX this should use the frame poisoning code
volatile int *p = 0;
gDummyCounter += *p; // TODO annotation saying we know
// this is crazy
}
void
mozalloc_abort(const char* const msg)
{
fputs(msg, stderr);
fputs("\n", stderr);
#if defined(XP_UNIX) && !defined(XP_MACOSX)
abort();
#elif defined(_MSC_VER)
__debugbreak();
#elif defined(XP_WIN)
DebugBreak();
#endif
// abort() doesn't trigger breakpad on Mac, "fall through" to the
// fail-safe code
// Still haven't aborted? Try dereferencing null.
TouchBadMemory();
// Still haven't aborted? Try _exit().
_exit(127);
}