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

[Jonathan Yong <10walls@gmail.com>]

On 2/22/23 09:25, Jakub Jelinek wrote:
> Hi!
> 
> 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
> 
> 	Jakub
> 

Achim, mind looking at this?
Resending due to mail client problems, hopefully not a duplicate.