Re: [patch/RFC] ld/pe-dll.c: mark .reloc section as discardable unlessbuilding a relocatable dll

[Charles Wilson <cwilson at ece dot gatech dot edu>]

Danny Smith wrote:

> If the DLL was built with --shared,  the .reloc section is not marked as discardable.
> The patch only effects .exe files and dll's built with --dll switch.  
>
> Uh, oh, I see the  problem now.  Some makefiles (eg the mingw runtime rule for
> libmingwm10.dll)and libtool still use the 'old' way of building relocatable dll's
> with dlltool. eg
>
> gcc -s -Wl,--base-file,mydll.base -o mydll.dll mydll.o -Wl,-e,_mydll_init@12 
> dlltool --base-file mydll.base --def mydll.def --output-exp mydll.exp --dllname mydll.dll
> gcc -s -Wl,--base-file,mydll.base,mydll.exp -o mydll.dll mydll.o -Wl,-e,_mydll_init@12
> dlltool --base-file mydll.base --def mydll.def --output-exp mydll.exp --dllname mydll.dll
> gcc -Wl,mydll.exp -o mydll.dll mydll.o -Wl,-e,_mydll_init@12

Libtool 1.5 uses gcc -shared; only the defunct, but still widely used, 
libtool-1.4.3 uses dlltool.

> or the equivalent using --dll switch.
>
> So I see where my patch will cause problems. I withdraw it.
>
> Perhaps a new switch (--discardable-pe-dll-relocs) could be introduced and
> build_filler_bfd would use that?
>
> I suppose --strip -R .reloc isn't too hard, so maybe we just need to
> document how to build  a non-relocatable dll now using that.

Funny, this was a hot topic of debate on cygwin-apps/developers(?) about 
a year ago.  Nobody could remember how exactly to make a dll 
non-relocatable.  It came up because we were thinking of doing fancy 
non-reloc stuff for cygwin1.dll to help with the "fork/exec problem". 
But instead "we" developed the rebase tool...

> Also need to note the fact that the gcc -mdll switch is now effectiveley
> the same as -shared. 

Yup.  'Course, some of us (okay, maybe it's just me) are plain ignorant 
and thought they were the same all along. :-)

--
Chuck