[Bug target/18469] configure incorrectly defines gid_t

["joseph at codesourcery dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18469

--- Comment #4 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Mon, 16 Dec 2013, ktietz at gcc dot gnu.org wrote:

> The macros required in crtstuff.c are:
> - HAVE_GAS_HIDDEN
> - HAVE_LD_EH_FRAME_HDR

Various target macros used in target code as well as host code should, I 
suggest at <http://gcc.gnu.org/wiki/Top-Level_Libgcc_Migration>, be 
handled via the compiler predefining macros if -fbuilding-libgcc, with 
those predefines being used in target code instead of the macros from host 
tm.h.  (The exact list of host-side tm.h macros used in target code there 
may be out of date, but I expect it's still pretty close to what needs 
fixing to stop target code needing that host-side header.)

I suggest the same solution for configure-determined macros used by target 
code: predefine something if -fbuilding-libgcc, and use that predefine in 
target code.  That avoids duplicating the configure detection.

I definitely encourage cleaning things up in this area to improve the 
host/target separation in the build system.  I don't think any of the 
cases of target (or configure) macros used in target code are hard to fix; 
it just requires careful work on working out the right conversion for each 
of the many macros affected, making sure in every case that no files 
needing updating are missed out.