__declspec(selectany)

[Dan Kegel]

Boaz Harrosh (boaz at hishome.net) wrote:
> background:
> I have managed to compile ATL/WTL from MSVC6.
> I will have available a public patch-file for patching ATL/WTL to 
> compile under wine, Once I have every thing running
> 
> Question:
> All symbols and functions declared __declspec(selectany) show up as 
> "duplicate symbols" errors on the linker. Eliminating  it has the same 
> results.
> 
> I have searched in google and the few lines I found is that GCC will 
> accept  __declspec(selectany) if "-fms-extensions" is used. Well it will 
> accept it but will only ignore it all together.
> 
> Does any body know how to properly merge duplicate definitions of 
> symbols in GCC?

Yes, I think it's attribute((weak)).

> (before I go and change the code) maybe a command line switch to the 
> compiler or linker can do the trick ?

Part of the solution might be to apply the following patch to the
gcc-3.3 source tree:

Index: linux.h
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/config/i386/linux.h,v
retrieving revision 1.42
diff -u -d -u -r1.42 linux.h
--- linux.h	15 Nov 2002 14:57:12 -0000	1.42
+++ linux.h	5 Aug 2003 21:33:39 -0000
@@ -82,6 +82,14 @@
  	builtin_define ("__ELF__");		\
  	builtin_define ("__gnu_linux__");	\
  	builtin_assert ("system=posix");	\
+	builtin_define ("__stdcall=__attribute__((__stdcall__))");	\
+	builtin_define ("__cdecl=__attribute__((__cdecl__))");		\
+	builtin_define ("__declspec(x)=__attribute__((x))");		\
+	if (!flag_iso)							\
+	  {								\
+	    builtin_define ("_stdcall=__attribute__((__stdcall__))");	\
+	    builtin_define ("_cdecl=__attribute__((__cdecl__))");	\
+	  }								\
  	if (flag_pic)				\
  	  {					\
  	    builtin_define ("__PIC__");		\

but I'm sure more is needed; I haven't tested this at all.
(gcc/doc/extend.texi would need updating, too, at least,
and maybe whatever code implements -fms-extensions.)
I suspect the folks who did the original ms-extensions for gcc never
figured we'd be compiling Windows source code on Linux, but here we are...
- Dan

-- 
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045