Re: x86_64-solaris

[Rainer Orth]

Hi Karl,

I've just investigated a GCC bug report about a comparison failure on
Solaris/SPARC:

        PR target/88535
        sparcv9 gcc 7 causes comparison failure in sparc gcc 8 dwarf2out.o
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88535

where config.guess failed to notice that the build compiler was
64-bit-default, while the host/target was 32-bit-default.

This doesn't happen with the config.guess/config.sub currently bundled
with gcc mainline (2018-06-26 resp. 2018-07-03) where with a
64-bit-default gcc x86_64-pc-solaris2.11 is determined, while with
CC='gcc -m32' I get i386-pc-solaris2.11 just as expected.

When looking into bringing a similar change for Solaris/SPARC into
upstream config.guess, I was dismayed to find that the Solaris/x86
detection has since been broken by the patch in the current thread
(well, not really; without the raw message to reply to threading is
broken unfortunately), replacing the compiler-based determination of the
target triplet by one based on the capabilities of the host OS (using
isainfo -b).

I fear that this patch is seriously misguided and should be reverted,
since Solaris (since Solaris 10) is both 32 and 64-bit (at least on most
systems) and what at least the toolchain (gcc, binutils, gdb) cares about
is what is currently being compiled for.

Before demanding, with my GCC/GDB Solaris maintainer hat on ;-) a
wholesale reversal (and adding the corresponding code for
Solaris/SPARC), I'd like to know what drove Apostolos to his patch,
though, to understand which problem he was trying to solve.

        Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University