__attribute__((weak)) - in mingw

[Boaz Harrosh]

Hi List
I'm finally on my ass trying to redo the ATL/MFC Job from a year ago. 
This time I decided to start on windows with MinGW than move the MinGW 
makefiles to be used with winegcc. It is a grate test for winegcc and 
the windows API in general.
Well it turns out to be a very big test for MinGW as well. The headers 
are in a very bad shape. I had to use Wine headers to be able to 
compile. but I'll leave all that to a later e-mail.

[Q] I'm (well ATL is) using  __attribute__((weak)) (translated from 
__declspec( selectany) ) for instantiation of members and variables in 
headers. I had no problem with it On GCC in Linux (gcc 3.2.2). On MinGW 
I get below warning. And needless to say that I get a Linker duplicate 
symbol Error. Any Ideas on how to overcome this. Is this a g++ only bug?

<g++ warning example>
H:\Dinosaur\OneSource\MinGWStudio\msvc\atl\include\atlhost.h:56: 
warning: weak
declaration of `UINT ATL::WM_ATLGETCONTROL' not supported
</g++ warrning example>

<linker error example>
H:\Dinosaur\OneSource\MinGWStudio\msvc\atl\include\atlwin.h: multiple 
definition of `ATL::WM_ATLGETCONTROL'
H:\Dinosaur\OneSource\MinGWStudio\Samples\AtlWB\Debug\aboutdlg.o(.bss+0x1c):H:\Dinosaur\OneSource\MinGWStudio\msvc\atl\include\atlwin.h:

first defined here
</linker error example>


Please forgive me for sending it here and not to MinGW list. But I feel 
more at home here than there. ( :( )

Free Life
Boaz

[Danny Smith]

Boaz Harrosh wrote:
>   [Q] I'm (well ATL is) using  __attribute__((weak))
> (translated from
>  __declspec( selectany) ) for instantiation of members and variables in
>  headers. I had no problem with it On GCC in Linux (gcc 3.2.2). On MinGW 
IMAGE_COMDAT_SELECT_ANY is not quite same as PECOFF version of "weak" , but
AFAICT is equivalent to the GCC section flag ".linkonce discard".  I don't
think
there is a way for the user to specify that for data using an attribute, but it
could be done with asm statements.

.weak directive is partially supported in current binutils CVS.
__attribute__((weak)) is not supported by GCC-3.4.x but will be in the next
major GCC release (4.0.0).

The semantics of weak for PECOFF differ from that on Linux.See the PECOFF60
specs (Microsoft Portable Executable and Common Object File Format
Specification)  section on weak externals

Danny

[Thomas Larsen]

WineMine Now Reactos Mine Sweeper

Loglist

Enable Sound Support
Correctet some bugs in reg load save
Correctet some minor bugs
Implentet Help and about
Modifed the style and the pictures

Who will upload this for me will not send the patch to all this time'

Thomas


		
__________________________________ 
Do you Yahoo!? 
The all-new My Yahoo! - Get yours free! 
http://my.yahoo.com