[PATCH v3 0/2] Opt-out static C++ link check and tests

[PATCH v3 0/2] Opt-out static C++ link check and tests

[H.J. Lu]

Changes in v3:

1. Update install manual entries from Carlos's feedbacks.

The current glibc build and test will fail if static C++ link doesn't
work.  There are cases where static C++ link is hard to supported:

1. 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.
2. Glibc test won't finish because static C++ tests fail when the C++
toolchain doesn't have necessary static C++ libraries which may not be
easily installed.

Add --disable-static-c++-link-check configure option to disable the static
C++ link check.  Add --disable-static-c++-tests option to skip the static
C++ tests which also implies --disable-static-c++-link-check.

H.J. Lu (2):
  Add --disable-static-c++-link-check option [BZ #31412]
  Add --disable-static-c++-tests option [BZ #31797]

 INSTALL             | 17 +++++++++++++++++
 configure           | 44 ++++++++++++++++++++++++++++++++++++--------
 configure.ac        | 35 +++++++++++++++++++++++++----------
 manual/install.texi | 16 ++++++++++++++++
 nptl/Makefile       |  3 +++
 5 files changed, 97 insertions(+), 18 deletions(-)

-- 
2.45.2

[PATCH v3 1/2] Add --disable-static-c++-link-check option [BZ #31412]

[H.J. Lu]

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 <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 449b3650fa..16f636f4a5 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 <iostream>
@@ -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 <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 08ed4051b6..1f2e160542 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.
-- 
2.45.2

[PATCH v3 2/2] Add --disable-static-c++-tests option [BZ #31797]

[H.J. Lu]

By default, if the C++ toolchain lacks support for static linking,
configure fails to find the C++ header files and the glibc build fails.
The --disable-static-c++-link-check option allows the glibc build to
finish, but static C++ tests will fail if the C++ toolchain doesn't
have the necessary static C++ libraries which may not be easily installed.
Add --disable-static-c++-tests option to skip the static C++ link check
and tests.  This fixes BZ #31797.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
---
 INSTALL             |  9 +++++++++
 configure           | 22 ++++++++++++++++++----
 configure.ac        | 15 +++++++++++----
 manual/install.texi |  8 ++++++++
 nptl/Makefile       |  3 +++
 5 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/INSTALL b/INSTALL
index 16f636f4a5..a4c9528b6b 100644
--- a/INSTALL
+++ b/INSTALL
@@ -224,6 +224,15 @@ 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++-tests'
+     By default, if the C++ toolchain lacks support for static linking,
+     configure fails to find the C++ header files and the glibc build
+     fails.  '--disable-static-c++-link-check' allows the glibc build to
+     finish, but static C++ tests will fail if the C++ toolchain doesn't
+     have the necessary static C++ libraries.  Use this option to skip
+     the static C++ tests.  This option implies
+     '--disable-static-c++-link-check'.
+
 '--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
diff --git a/configure b/configure
index e236b503fe..1bae55b45b 100755
--- a/configure
+++ b/configure
@@ -771,6 +771,7 @@ ac_user_opts='
 enable_option_checking
 with_pkgversion
 with_bugurl
+enable_static_c___tests
 enable_static_c___link_check
 with_gd
 with_gd_include
@@ -1441,6 +1442,8 @@ 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++-tests
+                          disable static C++ tests[default=no]
   --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
@@ -3858,6 +3861,20 @@ if test -z "$CPP"; then
 fi
 
 
+# This will get text that should go into config.make.
+config_vars=
+
+# Check whether --enable-static-c++-tests was given.
+if test ${enable_static_c___tests+y}
+then :
+  enableval=$enable_static_c___tests; static_cxx_tests=$enableval
+else $as_nop
+  static_cxx_tests=yes
+fi
+
+config_vars="$config_vars
+static-cxx-tests = $static_cxx_tests"
+
 # Check whether --enable-static-c++-link-check was given.
 if test ${enable_static_c___link_check+y}
 then :
@@ -4291,7 +4308,7 @@ esac
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
-if test $static_cxx_link_check = yes; then
+if test $static_cxx_link_check$static_cxx_tests = yesyes; then
   # Static case.
   old_LDFLAGS="$LDFLAGS"
   LDFLAGS="$LDFLAGS -static"
@@ -4338,9 +4355,6 @@ if test "`cd $srcdir; pwd -P`" = "`pwd -P`"; then
   as_fn_error $? "you must configure in a separate build directory" "$LINENO" 5
 fi
 
-# This will get text that should go into config.make.
-config_vars=
-
 # Check for a --with-gd argument and set libgd-LDFLAGS in config.make.
 
 # Check whether --with-gd was given.
diff --git a/configure.ac b/configure.ac
index ee64d49b03..e48957f318 100644
--- a/configure.ac
+++ b/configure.ac
@@ -52,6 +52,16 @@ fi
 AC_SUBST(cross_compiling)
 AC_PROG_CPP
 
+# This will get text that should go into config.make.
+config_vars=
+
+AC_ARG_ENABLE([static-c++-tests],
+	      AS_HELP_STRING([--disable-static-c++-tests],
+			     [disable static C++ tests@<:@default=no@:>@]),
+	      [static_cxx_tests=$enableval],
+	      [static_cxx_tests=yes])
+LIBC_CONFIG_VAR([static-cxx-tests], [$static_cxx_tests])
+
 AC_ARG_ENABLE([static-c++-link-check],
 	      AS_HELP_STRING([--disable-static-c++-link-check],
 			     [disable static C++ link check @<:@default=no@:>@]),
@@ -67,7 +77,7 @@ AC_LANG_PUSH([C++])
 AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
 	       [libc_cv_cxx_link_ok=yes],
 	       [libc_cv_cxx_link_ok=no])
-if test $static_cxx_link_check = yes; then
+if test $static_cxx_link_check$static_cxx_tests = yesyes; then
   # Static case.
   old_LDFLAGS="$LDFLAGS"
   LDFLAGS="$LDFLAGS -static"
@@ -92,9 +102,6 @@ if test "`cd $srcdir; pwd -P`" = "`pwd -P`"; then
   AC_MSG_ERROR([you must configure in a separate build directory])
 fi
 
-# This will get text that should go into config.make.
-config_vars=
-
 # Check for a --with-gd argument and set libgd-LDFLAGS in config.make.
 AC_ARG_WITH([gd],
 	    AS_HELP_STRING([--with-gd=DIR],
diff --git a/manual/install.texi b/manual/install.texi
index 1f2e160542..8172402ccd 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++-tests
+By default, if the C++ toolchain lacks support for static linking,
+configure fails to find the C++ header files and the glibc build fails.
+@option{--disable-static-c++-link-check} allows the glibc build to finish,
+but static C++ tests will fail if the C++ toolchain doesn't have the
+necessary static C++ libraries.  Use this option to skip the static C++
+tests.  This option implies @option{--disable-static-c++-link-check}.
+
 @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.
diff --git a/nptl/Makefile b/nptl/Makefile
index b3f8af2e1c..cf85a3717d 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -545,6 +545,9 @@ tests-static += \
   # tests-static
 
 tests += tst-cancel24-static
+ifeq ($(static-cxx-tests),no)
+tests-unsupported += tst-cancel24-static
+endif
 
 tests-internal += \
   tst-sem11-static \
-- 
2.45.2

Re: [PATCH v3 0/2] Opt-out static C++ link check and tests

[H.J. Lu]

[-- Attachment #1: Type: text/plain, Size: 1481 bytes --]

On Fri, Jun 21, 2024, 6:29 AM H.J. Lu <hjl.tools@gmail.com> wrote:

> Changes in v3:
>
> 1. Update install manual entries from Carlos's feedbacks.
>
> The current glibc build and test will fail if static C++ link doesn't
> work.  There are cases where static C++ link is hard to supported:
>
> 1. 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.
> 2. Glibc test won't finish because static C++ tests fail when the C++
> toolchain doesn't have necessary static C++ libraries which may not be
> easily installed.
>
> Add --disable-static-c++-link-check configure option to disable the static
> C++ link check.  Add --disable-static-c++-tests option to skip the static
> C++ tests which also implies --disable-static-c++-link-check.
>
> H.J. Lu (2):
>   Add --disable-static-c++-link-check option [BZ #31412]
>   Add --disable-static-c++-tests option [BZ #31797]
>
>  INSTALL             | 17 +++++++++++++++++
>  configure           | 44 ++++++++++++++++++++++++++++++++++++--------
>  configure.ac        | 35 +++++++++++++++++++++++++----------
>  manual/install.texi | 16 ++++++++++++++++
>  nptl/Makefile       |  3 +++
>  5 files changed, 97 insertions(+), 18 deletions(-)
>
> --
> 2.45.2
>

Hi Carlos,

Do they look OK?

Thanks.

H.J.

>