From 23f12e6e0c95aaf8b5b4973d029db794a43f248a Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 20 Jun 2024 15:28:12 -0700 Subject: [PATCH] Add --disable-static-c++-link-check option [BZ #31412] 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. Signed-off-by: H.J. Lu --- 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 208ec98d4b..02151e6e99 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 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. + '--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 1df2f2e6d1..e236b503fe 100755 --- a/configure +++ b/configure @@ -771,6 +771,7 @@ ac_user_opts=' enable_option_checking with_pkgversion with_bugurl +enable_static_c___link_check with_gd with_gd_include with_gd_lib @@ -1440,6 +1441,8 @@ 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] @@ -3855,6 +3858,15 @@ 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 $as_nop + static_cxx_link_check=yes +fi + + # We need the C++ compiler only for testing. @@ -4279,10 +4291,11 @@ esac fi rm -f core conftest.err conftest.$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 @@ -4304,7 +4317,8 @@ esac 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="$LDFLAGS -static" + AC_LINK_IFELSE([AC_LANG_SOURCE([ #include int @@ -74,9 +81,10 @@ main() return 0; } ])], - [], - [libc_cv_cxx_link_ok=no]) -LDFLAGS="$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 6504d02c62..6b6595ac91 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 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.