Re: [Patch/C++]: Use dllonexit for static destructors on mingw32

[Mark Mitchell <mark at codesourcery dot com>]

Danny Smith wrote:

> 2006-10-27  Danny Smith  <dannysmith@users.sourceforge.net>
>  
> 	* target.h (targetm.cxx.use_dllonexit): New target hook.
> 	* target-def.h: (TARGET_CXX_USE_DLLONEXIT): Define default.
> 	* config/i386/mingw32.h (TARGET_CXX_USE_DLLONEXIT): Override
> 	default.
> 	* doc/tm.texi (TARGET_CXX_USE_DLLONEXIT): Document.
>
> cp/Changelog
>
> 	*decl2.c (one_static_initialization_or_destruction): Check,
> 	set guard variable and register static destructor here if
> 	targetm.cxx.use_dllonexit.
> 	(cp_finish_file): Don't generate destructor if
> 	targetm.cxx.use_dllonexit.

I think the idea of this patch.

However, I think that you should key off of flag_use_cxa_atexit whether 
than adding a separate hook.  The only difference should be that in 
register_dtor_fn, you check a target hook that says that you should call 
atexit, not __cxa_atexit.  I suggest naming the hook 
TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT.  There is already prior art, in 
that it's how we already handle the ARM EABI aeabi_atexit function.
	
Then, on MinGW, just default --enable-use-cxa-atexit (sp?) to true, or 
require that users provide it explicitly.

Thanks,

--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
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