Re: [PATCH] cygwin: Don't try to support multilibs [PR107998]

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Feb 22, 2023 at 01:02:58PM +0000, Jonathan Yong wrote:
> On 2/22/23 09:25, Jakub Jelinek wrote:
> > As discussed in the PR, t-cygwin-w64 file has been introduced in 2013
> > and has one important problem, two different multilib options -m64 and -m32,
> > but MULTILIB_DIRNAMES with just one word in it.
> > Before the genmultilib sanity checking was added, my understanding is that
> > this essentially resulted in effective --disable-multilib,
> > $ gcc -print-multi-lib
> > .;
> > ;@m32
> > $ gcc -print-multi-directory
> > .
> > $ gcc -print-multi-directory -m64
> > .
> > $ gcc -print-multi-directory -m32
> > 
> > $ gcc -print-multi-os-directory
> > ../lib
> > $ gcc -print-multi-os-directory -m64
> > ../lib
> > $ gcc -print-multi-os-directory -m32
> > ../lib32
> > and because of the way e.g. config-ml.in operates
> > multidirs=
> > for i in `${CC-gcc} --print-multi-lib 2>/dev/null`; do
> >    dir=`echo $i | sed -e 's/;.*$//'`
> >    if [ "${dir}" = "." ]; then
> >      true
> >    else
> >      if [ -z "${multidirs}" ]; then
> >        multidirs="${dir}"
> >      else
> >        multidirs="${multidirs} ${dir}"
> >      fi
> >    fi
> > done
> > dir was . first time (and so nothing was done) and empty
> > second time, multidirs empty too, so multidirs was set to empty
> > like it would be with --disable-multilib.
> > 
> > With the added sanity checking the build fails unless --disable-multilib
> > is used in configure (dunno whether people usually configure that way
> > on cygwin).
> > 
> > > From what has been said in the PR, multilibs were not meant to be supported
> > and e.g. cygwin headers probably aren't ready for it.
> > 
> > So the following patch just removes the file with the (incorrect) multilib
> > stuff instead of fixing it (say by setting MULTILIB_DIRNAMES to 64 32).
> > 
> > I have no way to test this though, no Windows around, can anyone please
> > test this?  I just would like to get some progress on the P1s we have...
> > 
> > 2023-02-22  Jakub Jelinek  <jakub@redhat.com>
> > 
> > 	PR target/107998
> > 	* config.gcc (x86_64-*-cygwin*): Don't add i386/t-cygwin-w64 into
> > 	$tmake_file.
> > 	* config/i386/t-cygwin-w64: Remove.
> > 
> > --- gcc/config.gcc.jj	2023-02-18 12:38:30.803025062 +0100
> > +++ gcc/config.gcc	2023-02-21 17:07:12.143164563 +0100
> > @@ -2105,7 +2105,7 @@ x86_64-*-cygwin*)
> >   	need_64bit_isa=yes
> >   	tm_file="${tm_file} i386/unix.h i386/bsd.h i386/gas.h i386/cygming.h i386/cygwin.h i386/cygwin-w64.h i386/cygwin-stdint.h"
> >   	xm_file=i386/xm-cygwin.h
> > -	tmake_file="${tmake_file} i386/t-cygming t-slibgcc i386/t-cygwin-w64"
> > +	tmake_file="${tmake_file} i386/t-cygming t-slibgcc"
> >   	target_gtfiles="$target_gtfiles \$(srcdir)/config/i386/winnt.cc"
> >   	extra_options="${extra_options} i386/cygming.opt i386/cygwin.opt"
> >   	extra_objs="${extra_objs} winnt.o winnt-stubs.o"
> > --- gcc/config/i386/t-cygwin-w64.jj	2020-01-12 11:54:36.333414616 +0100
> > +++ gcc/config/i386/t-cygwin-w64	2023-02-21 17:06:44.121572616 +0100
> > @@ -1,3 +0,0 @@
> > -MULTILIB_OPTIONS = m64/m32
> > -MULTILIB_DIRNAMES = 64
> > -MULTILIB_OSDIRNAMES = ../lib ../lib32
> 
> Achim, mind looking at this?
> Resending due to mail client problems, hopefully not a duplicate.

NightStrike on IRC said he has tested the patch and it worked fine.

Is the patch ok for trunk then?

	Jakub