Re: [PATCH] glibc/sparc: Assume GOTDATA support in the toolchain

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On 04/10/2019 08:30, Florian Weimer wrote:
> Dave,
> 
> I believe this configure check is no longer necessary.  We require
> binutils 2.25 or later and GCC 6.2 or later for building glibc, and
> binutils and GCC support are older than that.  The only possible
> exception is if someone managed to build GCC 6.2 with an older binutils
> without GOTDATA support, but I don't think that happens in practice.

It would require also to have GCC built with an outdate binutils, 
but either configure it or glibc build to use a newer one.

Also R_SPARC_GOTDATA_* support seemed to be added by 739f7f82bed 
(binutils 2.19), which is quite old.

> 
> HAVE_GCC_GOTDATA has apparently never been used.
> 
> The sparc targets in build-many-glibcs.py still build with this change.
> 
> Thanks,
> Florian
> 
> 2019-10-04  Florian Weimer  <fweimer@redhat.com>
> 
> 	* config.h.in (HAVE_GCC_GOTDATA): Remove.
> 	* sysdeps/sparc/configure.ac: Remove checks for HAVE_GCC_GOTDATA
> 	and PI_STATIC_AND_HIDDEN.  Always define PI_STATIC_AND_HIDDEN.
> 	* sysdeps/sparc/configure: Regenerate.

LGTM.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> 
> diff --git a/config.h.in b/config.h.in
> index 824dfe8d8c..dea43df438 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -47,9 +47,6 @@
>  #undef	STACK_PROTECTOR_LEVEL
>  #endif
>  
> -/* Defined on SPARC if GCC emits GOTDATA relocations.  */
> -#undef  HAVE_GCC_GOTDATA
> -
>  /* Define if the linker supports the -z combreloc option.  */
>  #undef	HAVE_Z_COMBRELOC
>  

Ok.

> diff --git a/sysdeps/sparc/configure b/sysdeps/sparc/configure
> index bc6ac14e9f..491b00f0dc 100644
> --- a/sysdeps/sparc/configure
> +++ b/sysdeps/sparc/configure
> @@ -1,41 +1,4 @@
>  # This file is generated from configure.ac by Autoconf.  DO NOT EDIT!
>   # Local configure fragment for sysdeps/sparc.
>  
> -# Check for a GCC emitting GOTDATA relocations.
> -{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sparc gcc GOTDATA reloc support" >&5
> -$as_echo_n "checking for sparc gcc GOTDATA reloc support... " >&6; }
> -if ${libc_cv_sparc_gcc_gotdata+:} false; then :
> -  $as_echo_n "(cached) " >&6
> -else
> -  cat > conftest.c <<\EOF
> -int data;
> -int foo(void)
> -{
> -	return data;
> -}
> -EOF
> -libc_cv_sparc_gcc_gotdata=no
> -if { ac_try='${CC-cc} -S $CFLAGS -O2 -fPIC conftest.c 1>&5'
> -  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> -  (eval $ac_try) 2>&5
> -  ac_status=$?
> -  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> -  test $ac_status = 0; }; }; then
> -  if grep -q 'gdop_hix22' conftest.s \
> -     && grep -q 'gdop_lox10' conftest.s; then
> -    libc_cv_sparc_gcc_gotdata=yes
> -  fi
> -fi
> -rm -f conftest*
> -fi
> -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_sparc_gcc_gotdata" >&5
> -$as_echo "$libc_cv_sparc_gcc_gotdata" >&6; }
> -if test $libc_cv_sparc_gcc_gotdata = yes; then
> -  $as_echo "#define HAVE_GCC_GOTDATA 1" >>confdefs.h
> -
> -fi
> -
> -if test $libc_cv_sparc_gcc_gotdata = yes; then
> -  $as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
> -
> -fi
> +$as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
> diff --git a/sysdeps/sparc/configure.ac b/sysdeps/sparc/configure.ac
> index 43ad541464..5cdc0a984c 100644
> --- a/sysdeps/sparc/configure.ac
> +++ b/sysdeps/sparc/configure.ac
> @@ -1,30 +1,4 @@
>  GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>  # Local configure fragment for sysdeps/sparc.
>  
> -# Check for a GCC emitting GOTDATA relocations.
> -AC_CACHE_CHECK(for sparc gcc GOTDATA reloc support, libc_cv_sparc_gcc_gotdata, [dnl
> -changequote(,)dnl
> -cat > conftest.c <<\EOF
> -int data;
> -int foo(void)
> -{
> -	return data;
> -}
> -EOF
> -changequote([,])dnl
> -dnl
> -libc_cv_sparc_gcc_gotdata=no
> -if AC_TRY_COMMAND(${CC-cc} -S $CFLAGS -O2 -fPIC conftest.c 1>&AS_MESSAGE_LOG_FD); then
> -  if grep -q 'gdop_hix22' conftest.s \
> -     && grep -q 'gdop_lox10' conftest.s; then
> -    libc_cv_sparc_gcc_gotdata=yes
> -  fi
> -fi
> -rm -f conftest*])
> -if test $libc_cv_sparc_gcc_gotdata = yes; then
> -  AC_DEFINE(HAVE_GCC_GOTDATA)
> -fi
> -
> -if test $libc_cv_sparc_gcc_gotdata = yes; then
> -  AC_DEFINE(PI_STATIC_AND_HIDDEN)
> -fi
> +AC_DEFINE(PI_STATIC_AND_HIDDEN)
> 

Ok.