Avoid use of libgcc_s and libgcc_eh when building glibc

[Joseph S. Myers]

On Thu, 1 Nov 2012, Thomas Schwinge wrote:

> With the following patch, we againt get:
> 
>     gcc-4.6 -nostdlib -nostartfiles -static [-o tst-empty crt0 crti crtbegin tst-empty.o] -Wl,--start-group [...]/libc.a [...]/mach/libmachuser.a [...]/hurd/libhurduser.a -lgcc -lgcc_eh  -Wl,--end-group [crtend crtn]
> 
> ..., which does link and seems reasonable to me (final tests still
> running), but I'd like Joseph/Roland to confirm this is the correct
> approach.

Given that such variables are overridden for Hurd, this looks reasonable.  
But really much of what Makeconfig has under "These are the configuration 
variables." should neither be configured by users in configparms, nor by 
sysdeps makefiles, and some things for sysdeps makefiles (such as 
gnulib-arch) shouldn't be configured by users, only by sysdeps makefiles.  
I'd say that variables such as link-libc-static shouldn't be configured in 
either place - there should be some more narrowly defined variable that 
Hurd can set to add the extra libraries needed for Hurd.

(So, I think the patch makes sense, but the configuration variables 
section in Makeconfig could do with reworking into a section for users to 
configure, a section that sysdeps makefiles may change but users shouldn't 
need to, and other variables that aren't configuration at all - 
link-libc-static should be in of the third type, while Hurd would set a 
variable of the second type used by link-libc-static.)

-- 
Joseph S. Myers
joseph@codesourcery.com