Re: PING^2: [PATCH] Add --enable-first-stage-cross configure option

[Jeff Law <jeffreyalaw@gmail.com>]

On 1/9/2022 2:26 PM, Serge Belyshev wrote:
> Ping: [PATCH] Add --enable-first-stage-cross configure option
> https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575318.html
>
>
> Add --enable-first-stage-cross configure option
>
> Build static-only, C-only compiler that is sufficient to cross compile
> glibc.  This option disables various runtime libraries that require
> libc to compile, turns on --with-newlib, --without-headers,
> --disable-decimal-float, --disable-shared, --disable-threads, and sets
> --enable-languages=c.
>      
> Rationale: current way of building first stage compiler of a cross
> toolchain requires specifying a list of target libraries that are not
> going to be compiled due to their dependency on target libc.  This
> list is not documented in gccinstall.texi and sometimes changes.  To
> simplify the procedure, it is better to maintain that list in the GCC
> itself.
>
> Usage example as a patch to glibc's scripts/build-many-libcs.py:
>
> diff --git a/scripts/build-many-glibcs.py b/scripts/build-many-glibcs.py
> index 580d25e8ee..3a6a7be76b 100755
> --- a/scripts/build-many-glibcs.py
> +++ b/scripts/build-many-glibcs.py
> @@ -1446,17 +1446,7 @@ class Config(object):
>               # required to define inhibit_libc (to stop some parts of
>               # libgcc including libc headers); --without-headers is not
>               # sufficient.
> -            cfg_opts += ['--enable-languages=c', '--disable-shared',
> -                         '--disable-threads',
> -                         '--disable-libatomic',
> -                         '--disable-decimal-float',
> -                         '--disable-libffi',
> -                         '--disable-libgomp',
> -                         '--disable-libitm',
> -                         '--disable-libmpx',
> -                         '--disable-libquadmath',
> -                         '--disable-libsanitizer',
> -                         '--without-headers', '--with-newlib',
> +            cfg_opts += ['--enable-first-stage-cross',
>                            '--with-glibc-version=%s' % self.ctx.glibc_version
>                            ]
>               cfg_opts += self.first_gcc_cfg
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu, and
> tested with build-many-glibcs.py with the above patch.
>
> OK for mainline?
>
>
> ChangeLog:
>
> 	* configure.ac: Add --enable-first-stage-cross.
> 	* configure: Regenerate.
>
> gcc/ChangeLog:
>
> 	* doc/install.texi: Document --enable-first-stage-cross.
I'm not really sure we need a patch for this.  Isn't it sufficient to 
"make all-gcc && make all-target-libgcc"?  Folks have been doing that 
for decades.

Jeff