Hello,
One of things mingw32 C runtime lacks is an implementation of
__cxa_atexit.
However, as explained in the comment below, some of the behaviour of
__cxa_atexit is already in the C runtime atexit implementation.
Adding the object below to libstdc++ or libgcc.a and configuring with
__cxa_atexit enabled produces PASSES for the three __cxa_atexit
dependent testcases. It works fine in tests with destruction of objects
in dll's too, whether these dlls are unloaded at process exit or by
earlier calls to UnloadLibrary. (No, it doesn't allow exceptions to be
thrown and caugtht across dll boundaries -- thats another story for gcc
4.3 -- but it removes one obstacle.)
Although this keeps the changes local to mingw32 code, I don't really
like adding a fake __cxa_atexit to a runtime lib. So, the other option
would be to add a 'if (flag_use_dllonexit)' code to cp/decl.c and
decl2.c to parallel flag_use_cxa_atexit.
Adding a real __cxa_atexit to mingw runtime is of course also possible,
but I thought I'd attempt the easy options first.
I would appreciate any comments.
Danny
/* mingw32-cxa_atexit.c
Contributed by Danny Smith ([EMAIL PROTECTED])
Copyright (C) 2006 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA. */
/* On mingw32, each dll has its own on-exit table, which is initialized
on dll load, Calls to atexit or onexit will register functions in the
on-exit table of the containing module. Each dll-specific on-exit
table
runs when that dll unloads. The calls to atexit from the main app,
(ie,
including all static libs) are finalized at process exit.
cc1plus currently ignores the argument to __cxa_atexit-registered
functions. If that changes, we will need to replace this with a
real
__cxa_atexit implementation in mingw runtime. */
#include <stdlib.h>
/* We don't need an explicit dll handle. The handle is always 'this'. */
void* __dso_handle = NULL;
int __mingw_cxa_atexit (void (*)(void *), void *, void *);
int __mingw_cxa_atexit (void (*func)(void *),
void *arg __attribute__((unused)),
void *d __attribute__((unused)))
{
return atexit ((void (*) (void)) func);
}
int __cxa_atexit (void (*)(void *), void *, void *)
__attribute__ ((alias ("__mingw_cxa_atexit")));
