[Bug preprocessor/48957] GCC's handling of include-fixed does not work well with --sysroot

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48957

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |build
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2018-03-12
                 CC|                            |egallager at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to joseph@codesourcery.com from comment #1)
> On Wed, 11 May 2011, psmith at gnu dot org wrote:
> 
> > I think that the include-fixed directory should be associated with the sysroot,
> 
> It should be associated with each system include directory (sysroot or 
> otherwise) - so there should be a fixed version of /usr/local/include, 
> searched immediately before /usr/local/include, and likewise for 
> /usr/include.

This sounds like an agreement that some form of change would be worthwhile; I'm
going to take that as confirmation.

> But there are certainly sysroot uses where include-fixed is 
> still relevant - where the sysroot is based on a copy of that used when 
> GCC was built, but with extra libraries added.  (That's the case of 
> sysroots that works most reliably for other reasons as well; GCC's runtime 
> libraries get configured depending on the libc libraries and headers 
> present when GCC was built, and in some cases the headers affect the 
> configuration of GCC itself as well as GCC's libraries.)
> 
> http://gcc.gnu.org/ml/gcc-patches/2010-07/msg02088.html
> http://gcc.gnu.org/ml/gcc/2004-11/msg00255.html

Shouldn't it be possible to come up with a solution that still supports those
cases while also fixing the cases Paul described?