• thoughtpolice's avatar
    Detect linker information at runtime. Fixes Trac #6063 · 71a194d8
    thoughtpolice authored
    Previously, we did ./configure time checks to see if 'GNU ld' supported
    certain options. If it does, we bake those options into the link step.
    See Trac #5240.
    Unfortunately, the linker we use at runtime can change for several
    reasons. One is that the user specifies -pgml 'foo'. The other is if
    /usr/bin/ld or whatnot changes from when GHC was built.  Those options
    mentioned earlier are specific to GNU ld, but many systems support GNU
    gold too. This is Trac #6063.
    So we need to check at runtime what linker we're using. This is actually
    a little bit complicated because we normally use the C compiler as our
    linker. Windows and OS X are also special here.
    Finally, this patch also unconditionally gives '--hash-size=31' and
    '--reduce-memory-overheads' to the system linker if it's GNU ld. These
    options have been supported for 8+ years from what I can see, and there
    are probably a lot of other reasons why GHC would not work with such an
    ancient binutils, all things considered.
    See Note [Run-time linker info] in SysTools for details. There are
    plenty of comments as well in the surrounding code.
    Signed-off-by: thoughtpolice's avatarAustin Seipp <aseipp@pobox.com>
configure.ac 30.7 KB