Re: [PATCH] PE+: Remove the stdcall fixup machinery

вт, 1 сент. 2026 г. в 10:49, Jan Beulich <[email protected]>:
>
> On 29.08.2026 19:05, Oleg Tolmatcev wrote:
> > Win64 has a single calling convention, so symbols never carry the @nn
> > stdcall decoration.  The stdcall fixup pass in pep.em can therefore
> > never find a match, and neither can --kill-at or --add-stdcall-alias,
> > both of which only act on names containing '@'.
> >
> > Remove the stdcall fixup pass.  Besides being dead code, it traversed
> > the whole link hash table once per undefined cdecl symbol, so it was
> > quadratic.
> >
> > The four affected options are still parsed, and now simply ignored, so
> > that command lines shared with i386 PE targets keep working.  They are
> > no longer listed in --help, and ld.texi records that they have no
> > effect on PE+ targets.
> >
> > ld/ChangeLog:
> >
> >       * emultempl/pep.em (pep_enable_stdcall_fixup, pep_undef_found_sym)
> >       (pep_undef_cdecl_match, set_decoration, pep_fixup_stdcalls):
> >       Remove.
> >       (gld${EMULATION_NAME}_list_options): Don't list --add-stdcall-alias,
> >       --disable-stdcall-fixup, --enable-stdcall-fixup or --kill-at.
> >       (gld${EMULATION_NAME}_handle_option): Accept and ignore
> >       OPTION_KILL_ATS, OPTION_STDCALL_ALIASES,
> >       OPTION_ENABLE_STDCALL_FIXUP and OPTION_DISABLE_STDCALL_FIXUP.
> >       (gld${EMULATION_NAME}_after_open): Don't call pep_fixup_stdcalls.
> >       * ld.texi (--add-stdcall-alias, --enable-stdcall-fixup)
> >       (--kill-at): Note that these have no effect on PE+ targets.
> >
> > Signed-off-by: Oleg Tolmatcev <[email protected]>
>
> Looks largely good to me, just one remark:
>
> > @@ -768,16 +763,10 @@ gld${EMULATION_NAME}_handle_option (int optc)
> >        pep_dll_add_excludes (optarg, EXCLUDEFORIMPLIB);
> >        break;
> >      case OPTION_KILL_ATS:
> > -      pep_dll_kill_ats = 1;
> > -      break;
> >      case OPTION_STDCALL_ALIASES:
> > -      pep_dll_stdcall_aliases = 1;
> > -      break;
> >      case OPTION_ENABLE_STDCALL_FIXUP:
> > -      pep_enable_stdcall_fixup = 1;
> > -      break;
> >      case OPTION_DISABLE_STDCALL_FIXUP:
> > -      pep_enable_stdcall_fixup = 0;
> > +      /* Ignored: stdcall and cdecl are unsupported on Win64.  */
> >        break;
>
> But Win64 isn't the only environment where PE32+ binaries can be used.
> I'd prefer if Windows wasn't mentioned here, or if at least this was
> generalized by e.g. saying "on platforms using Win64's ABI" (which
> would then include e.g. UEFI). I can adjust while committing, but of
> course only if you agree (and if you have preferred alternative
> wording, please also indicate that preference of yours).
>
> Jan

Thanks for the review. I didn't even know that, so I am of course OK
with any wording.

Oleg