[PATCH v2 1/2] Add --disable-static-c++-link-check option [BZ #31412]
Carlos O'Donell
carlos@redhat.com
Thu Jun 20 18:22:59 GMT 2024
On 5/25/24 8:26 AM, H.J. Lu wrote:
> The current minimum GCC version of glibc build is GCC 6.2 or newer. But
> building i686 glibc with GCC 6.4 on Fedora 40 failed since the C++ header
> files couldn't be found which was caused by the static C++ link check
> failure due to missing __divmoddi4 which was referenced in i686 libc.a
> and added to GCC 7. Add --disable-static-c++-link-check configure option
> to disable the static C++ link test. The newly built i686 libc.a can be
> used by GCC 6.4 to create static C++ tests. This fixes BZ #31412.
OK with the suggested text changes.
You may keep my RB if you make the suggested textual changes.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> ---
> INSTALL | 8 ++++++++
> configure | 24 +++++++++++++++++++-----
> configure.ac | 22 +++++++++++++++-------
> manual/install.texi | 8 ++++++++
> 4 files changed, 50 insertions(+), 12 deletions(-)
>
> diff --git a/INSTALL b/INSTALL
> index c8c524527b..d8b06f20aa 100644
> --- a/INSTALL
> +++ b/INSTALL
> @@ -224,6 +224,14 @@ if 'CFLAGS' is specified it must enable optimization. For example:
> By default for x86_64, the GNU C Library is built with the vector
> math library. Use this option to disable the vector math library.
>
> +'--disable-static-c++-link-check'
> + By default, if the C++ toolchain doesn't not support static
> + linking, configure couldn't find the C++ header files and the glibc
> + build fails. Use this option to disable the static C++ link check
> + so that the C++ header files can be located. The newly built
> + libc.a can be used to create static C++ tests if the C++ toolchain
> + has necessary static C++ libraries.
> +
> '--disable-scv'
> Disable using 'scv' instruction for syscalls. All syscalls will
> use 'sc' instead, even if the kernel supports 'scv'. PowerPC only.
> diff --git a/configure b/configure
> index 432e40a592..31205ce568 100755
> --- a/configure
> +++ b/configure
> @@ -778,6 +778,7 @@ ac_user_opts='
> enable_option_checking
> with_pkgversion
> with_bugurl
> +enable_static_c___link_check
> with_gd
> with_gd_include
> with_gd_lib
> @@ -1447,6 +1448,8 @@ Optional Features:
> --disable-option-checking ignore unrecognized --enable/--with options
> --disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no)
> --enable-FEATURE[=ARG] include FEATURE [ARG=yes]
> + --disable-static-c++-link-check
> + disable static C++ link check [default=no]
> --disable-sanity-checks really do not use threads (should not be used except
> in special situations) [default=yes]
> --enable-shared build shared library [default=yes if GNU ld]
> @@ -3810,6 +3813,15 @@ if test -z "$CPP"; then
> fi
>
>
> +# Check whether --enable-static-c++-link-check was given.
> +if test ${enable_static_c___link_check+y}
> +then :
> + enableval=$enable_static_c___link_check; static_cxx_link_check=$enableval
> +else $as_nop
> + static_cxx_link_check=yes
> +fi
> +
> +
> # We need the C++ compiler only for testing.
>
>
> @@ -4220,10 +4232,11 @@ else $as_nop
> fi
> rm -f core conftest.err conftest.$ac_objext conftest.beam \
> conftest$ac_exeext conftest.$ac_ext
> -# Static case.
> -old_LDFLAGS="$LDFLAGS"
> -LDFLAGS="$LDFLAGS -static"
> -cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +if test $static_cxx_link_check = yes; then
> + # Static case.
> + old_LDFLAGS="$LDFLAGS"
> + LDFLAGS="$LDFLAGS -static"
> + cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> /* end confdefs.h. */
>
> #include <iostream>
> @@ -4244,7 +4257,8 @@ else $as_nop
> fi
> rm -f core conftest.err conftest.$ac_objext conftest.beam \
> conftest$ac_exeext conftest.$ac_ext
> -LDFLAGS="$old_LDFLAGS"
> + LDFLAGS="$old_LDFLAGS"
> +fi
> ac_ext=c
> ac_cpp='$CPP $CPPFLAGS'
> ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
> diff --git a/configure.ac b/configure.ac
> index bdc385d03c..ee64d49b03 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -52,6 +52,12 @@ fi
> AC_SUBST(cross_compiling)
> AC_PROG_CPP
>
> +AC_ARG_ENABLE([static-c++-link-check],
> + AS_HELP_STRING([--disable-static-c++-link-check],
> + [disable static C++ link check @<:@default=no@:>@]),
> + [static_cxx_link_check=$enableval],
> + [static_cxx_link_check=yes])
> +
> # We need the C++ compiler only for testing.
> AC_PROG_CXX
> # It's useless to us if it can't link programs (e.g. missing -lstdc++).
> @@ -61,10 +67,11 @@ AC_LANG_PUSH([C++])
> AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
> [libc_cv_cxx_link_ok=yes],
> [libc_cv_cxx_link_ok=no])
> -# Static case.
> -old_LDFLAGS="$LDFLAGS"
> -LDFLAGS="$LDFLAGS -static"
> -AC_LINK_IFELSE([AC_LANG_SOURCE([
> +if test $static_cxx_link_check = yes; then
> + # Static case.
> + old_LDFLAGS="$LDFLAGS"
> + LDFLAGS="$LDFLAGS -static"
> + AC_LINK_IFELSE([AC_LANG_SOURCE([
> #include <iostream>
>
> int
> @@ -74,9 +81,10 @@ main()
> return 0;
> }
> ])],
> - [],
> - [libc_cv_cxx_link_ok=no])
> -LDFLAGS="$old_LDFLAGS"
> + [],
> + [libc_cv_cxx_link_ok=no])
> + LDFLAGS="$old_LDFLAGS"
> +fi
> AC_LANG_POP([C++])])
> AS_IF([test $libc_cv_cxx_link_ok != yes], [CXX=])
>
> diff --git a/manual/install.texi b/manual/install.texi
> index 7c44594617..ac3728c301 100644
> --- a/manual/install.texi
> +++ b/manual/install.texi
> @@ -252,6 +252,14 @@ configure with @option{--disable-werror}.
> By default for x86_64, @theglibc{} is built with the vector math library.
> Use this option to disable the vector math library.
>
> +@item --disable-static-c++-link-check
> +By default, if the C++ toolchain doesn't not support static linking,
> +configure couldn't find the C++ header files and the glibc build fails.
> +Use this option to disable the static C++ link check so that the C++
> +header files can be located. The newly built libc.a can be used to
> +create static C++ tests if the C++ toolchain has necessary static C++
> +libraries.
Suggest:
By default, if the C++ toolchain lacks support for static linking,
configure fails to find the C++ header files and the glibc build fails.
Use this option to disable the static C++ link check so that the C++
header files can be located. The newly built libc.a can be used to
create static C++ tests if the C++ toolchain has the necessary static
C++ libraries.
> +
> @item --disable-scv
> Disable using @code{scv} instruction for syscalls. All syscalls will use
> @code{sc} instead, even if the kernel supports @code{scv}. PowerPC only.
--
Cheers,
Carlos.
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