[Bug bootstrap/107059] [13 regression] bootstrap failure after r13-2887-gb04208895fed34

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107059

--- Comment #28 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:a5a9237e2a78a9854f1f87e63ef5619cf8ba7360

commit r13-2932-ga5a9237e2a78a9854f1f87e63ef5619cf8ba7360
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Sep 29 12:04:24 2022 +0200

    driver, cppdefault: Unbreak bootstrap on Debian/Ubuntu [PR107059]

    My recent change to enable _Float{16,32,64,128,32x,64x,128x} for C++
    apparently broke bootstrap on some Debian/Ubuntu setups.
    Those multiarch targets put some headers into
    /usr/include/x86_64-linux-gnu/bits/ etc. subdirectory instead of
    /usr/include/bits/.
    This is handled by
        /* /usr/include comes dead last.  */
        { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0, 1, 2
},
        { NATIVE_SYSTEM_HEADER_DIR, NATIVE_SYSTEM_HEADER_COMPONENT, 0, 0, 1, 0
},
    in cppdefault.cc, where the 2 in the last element of the first initializer
    means the entry is ignored on non-multiarch and suffixed by the multiarch
    dir otherwise, so installed gcc has search path like:
    
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include
    
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed
     /usr/local/include
     /usr/include/x86_64-linux-gnu
     /usr/include
    (when installed with DESTDIR=/home/jakub/gcc/obj01inst).
    Now, when fixincludes is run, it is processing the whole /usr/include dir
    and all its subdirectories, so floatn{,-common.h} actually go into
    .../include-fixed/x86_64-linux-gnu/bits/floatn{,-common.h}
    because that is where they appear in /usr/include too.
    In some setups, /usr/include also contains /usr/include/bits ->
x86_64-linux-gnu/bits
    symlink and after the r13-2896 tweak it works.
    In other setups there is no /usr/include/bits symlink and when one
     #include <bits/floatn.h>
    given the above search path, it doesn't find the fixincluded header,
    as
   
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/bits/floatn.h
    doesn't exist and
   
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/x86_64-linux-gnu/bits/floatn.h
    isn't searched and so
    /usr/include/x86_64-linux-gnu/bits/floatn.h
    wins and we fail because of typedef whatever _Float128; and similar.
    The following patch ought to fix this.  The first hunk by arranging that
    the installed search path actually looks like:
    
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include
    
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed/x86_64-linux-gnu
    
/home/jakub/gcc/obj01inst/usr/local/bin/../lib/gcc/x86_64-pc-linux-gnu/13.0.0/include-fixed
     /usr/local/include
     /usr/include/x86_64-linux-gnu
     /usr/include
    and thus for include-fixed it treats it the same as /usr/include.
    The second FIXED_INCLUDE_DIR entry there is:
         { FIXED_INCLUDE_DIR, "GCC", 0, 0, 0,
           /* A multilib suffix needs adding if different multilibs use
              different headers.  */
     #ifdef SYSROOT_HEADERS_SUFFIX_SPEC
           1
     #else
           0
     #endif
         },
    where SYSROOT_HEADERS_SUFFIX_SPEC is defined only on vxworks or
mips*-mti-linux
    and arranges for multilib path to be appended there.  Neither of those
    systems is multiarch.
    This isn't enough, because when using the -B option, the driver adds
    -isystem .../include-fixed in another place, so the second hunk modifies
    that spot the same.
    /home/jakub/gcc/obj01/gcc/xgcc -B /home/jakub/gcc/obj01/gcc/
    then has search path:
     /home/jakub/gcc/obj01/gcc/include
     /home/jakub/gcc/obj01/gcc/include-fixed/x86_64-linux-gnu
     /home/jakub/gcc/obj01/gcc/include-fixed
     /usr/local/include
     /usr/include/x86_64-linux-gnu
     /usr/include
    which again is what I think we want to achieve.

    2022-09-29  Jakub Jelinek  <jakub@redhat.com>

            PR bootstrap/107059
            * cppdefault.cc (cpp_include_defaults): If
SYSROOT_HEADERS_SUFFIX_SPEC
            isn't defined, add FIXED_INCLUDE_DIR entry with multilib flag 2
            before FIXED_INCLUDE_DIR entry with multilib flag 0.
            * gcc.cc (do_spec_1): If multiarch_dir, add
            include-fixed/multiarch_dir paths before include-fixed paths.