On Mon, 16 Oct 2023, Tatsuyuki Ishi wrote:
>
>
> > On Oct 16, 2023, at 17:39, Richard Biener <rguent...@suse.de> wrote:
> >
> > On Mon, 16 Oct 2023, Tatsuyuki Ishi wrote:
> >
> >> lld and mold are platform-agnostic and not prefixed with target triple.
> >> Prepending the target triple makes it less likely to find the intended
> >> linker executable.
> >>
> >> A potential breaking change is that we no longer try to search for
> >> triple-prefixed lld/mold binaries anymore. However, since there doesn't
> >> seem to be support to build LLVM or mold with triple-prefixed executable
> >> names, it seems better to just not bother with that case.
> >>
> >> PR driver/111605
> >>
> >> gcc/Changelog:
> >>
> >> * collect2.cc (main): Do not prepend target triple to
> >> -fuse-ld=lld,mold.
> >> ---
> >> gcc/collect2.cc | 13 ++++++++-----
> >> 1 file changed, 8 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/gcc/collect2.cc b/gcc/collect2.cc
> >> index 63b9a0c233a..c943f9f577c 100644
> >> --- a/gcc/collect2.cc
> >> +++ b/gcc/collect2.cc
> >> @@ -865,12 +865,15 @@ main (int argc, char **argv)
> >> int i;
> >>
> >> for (i = 0; i < USE_LD_MAX; i++)
> >> - full_ld_suffixes[i]
> >> #ifdef CROSS_DIRECTORY_STRUCTURE
> >> - = concat (target_machine, "-", ld_suffixes[i], NULL);
> >> -#else
> >> - = ld_suffixes[i];
> >> -#endif
> >> + /* lld and mold are platform-agnostic and not prefixed with target
> >> + triple. */
> >> + if (!(i == USE_LLD_LD || i == USE_MOLD_LD))
> >> + full_ld_suffixes[i] = concat (target_machine, "-", ld_suffixes[i],
> >> + NULL);
> >> + else
> >> +#endif
> >> + full_ld_suffixes[i] = ld_suffixes[i];
> >>
> >> p = argv[0] + strlen (argv[0]);
> >> while (p != argv[0] && !IS_DIR_SEPARATOR (p[-1]))
> >
> > Since we later do
> >
> > /* Search the compiler directories for `ld'. We have protection against
> > recursive calls in find_a_file. */
> > if (ld_file_name == 0)
> > ld_file_name = find_a_file (&cpath, ld_suffixes[selected_linker],
> > X_OK);
> > /* Search the ordinary system bin directories
> > for `ld' (if native linking) or `TARGET-ld' (if cross). */
> > if (ld_file_name == 0)
> > ld_file_name = find_a_file (&path, full_ld_suffixes[selected_linker],
> > X_OK);
> >
> > I wonder how having full_ld_suffixes[LLD|MOLD] == ld_suffixes[LLD|MOLD]
> > fixes anything?
>
> Per the linked PR, the intended use case for this is when one wants to use
> their system lld/mold with a separately packaged cross toolchain, without
> requiring them to symlink their system lld/mold into the cross toolchain bin
> directory.
>
> (Note that the first search is against COMPILER_PATH while the latter is
> against PATH).
Ah. So what about instead adding here
/* Search the ordinary system bin directories for mold/lld even in
a cross configuration. */
if (ld_file_name == 0
&& selected_linker == ...)
ld_file_name = find_a_file (&path, ld_suffixes[selected_linker], X_OK);
instead? That would keep things working in case the user has a
xyz-arch-mold in the system dir but uses GNU ld on the host
otherwise, lacking a 'mold' binary there?
That is, we'd only add, not change what we search for.
Thanks,
Richard.
