[patch] Implement __cxa_atexit

Christopher Faylor me@cgf.cx
Mon Sep 13 17:06:00 GMT 2004

On Thu, Sep 09, 2004 at 03:47:42PM -0400, Jeff Johnston wrote:
>Patch checked in with modifications to make it compile for _REENT_SMALL.

It appears that this patch changes the size of the _reent structure,
causing problems for cygwin when interacting with any programs which
were linked with the previous structure.

Isn't changing the size of reent a bad idea, or, at least, isn't making
changes to the middle of _reent a no-no?


>-- Jeff J.
>Paul Brook wrote:
>>The attached patch implements __cxa_atexit and __cxa_finalize.
>>As the name suggests these are used by C++ code to register static object 
>>destructors. They are documented in section 3.3.5 of the C++ ABI 
>>Despite this they are generally provided by the C library, not the C++ 
>>runtime library.
>>I basically took the exitsing atexit/on_exit implementation, broke it out 
>>into separate files, and added the extra _dso_handle field. I also 
>>modified the _REENT_SMALL case to allow more than 32 handlers to be 
>>Tested with cross to arm-none-elf.
>>2004-09-03  Paul Brook  <paul@codesourcery.com>
>> * libc/include/sys/reent.h (struct _on_exit_args): Add _dso_handle
>> and _is_cxa.
>> (struct _atexit): Add _next when _REENT_SMALL.
>> (struct _reent): Add _atexit0 when _REENT_SMALL.
>> (_REENT_INIT_PTR): Adjust.
>> * libc/stdlib/Makefile.am (GENERAL_SOURCES): Add __atexit.c and
>> __call_exit.c.
>> (EXTENDED_SOURCES): Add cxa_atexit.c and cxa_finalize.c.
>> * libc/stdlib/Makefile.in: Regenerate.
>> * libc/stdlib/__atexit.c: New file.
>> * libc/stdlib/__call_atexit.c: New file.
>> * libc/stdlib/atexit.h: Remove old definitions.  Add new.
>> * libc/stdlib/atexit.c (atexit): Use __register_exitproc.
>> * libc/stdlib/cxa_atexit.c: New file.
>> * libc/stdlib/cxa_finalize.c: New file.
>> * libc/stdlib/exit.c (exit): Use __call_exitprocs.
>> * libc/stdlib/on_exit.c (on_exit): Use __register_exitproc.

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