* configure.in: Require assembler support for visibility, compiler

	support for visibility and aliases, linker support for various -z
	options.
	* Makeconfig: Remove conditional code which now is unnecessary.
	* config.h.in: Likewise.
	* config.make.in: Likewise.
	* dlfcn/Makefile: Likewise.
	* elf/Makefile: Likewise.
	* elf/dl-load.c: Likewise.
	* elf/rtld.c: Likewise.
	* include/libc-symbols.h: Likewise.
	* include/stdio.h: Likewise.
	* io/Makefile: Likewise.
	* io/fstat.c: Likewise.
	* io/fstat64.c: Likewise.
	* io/fstatat.c: Likewise.
	* io/fstatat64.c: Likewise.
	* io/lstat.c: Likewise.
	* io/lstat64.c: Likewise.
	* io/mknod.c: Likewise.
	* io/mknodat.c: Likewise.
	* io/stat.c: Likewise.
	* io/stat64.c: Likewise.
	* libio/stdio.c: Likewise.
	* nscd/Makefile: Likewise.
	* stdlib/Makefile: Likewise.
	* stdlib/atexit.c: Likewise.
	* sysdeps/generic/ldsodefs.h: Likewise.
	* sysdeps/i386/dl-machine.h: Likewise.
	* sysdeps/i386/sysdep.h: Likewise.
	* sysdeps/i386/i686/memcmp.S: Likewise.
	* sysdeps/powerpc/powerpc32/sysdep.h: Likewise.
	* sysdeps/unix/sysv/linux/i386/sigaction.c: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/sigaction.c: Likewise.

1 files changed, 27 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/configure b/sysdeps/unix/sysv/linux/configure
index 2701e27298..a8a9cc4702 100644
--- a/sysdeps/unix/sysv/linux/configure
+++ b/sysdeps/unix/sysv/linux/configure
@@ -251,6 +251,33 @@ case "$prefix" in
   ;;
 esac
 
+# Under Linux the NPTL add-on should be available.
+case $add_ons in
+  # It is available.  Good.
+  *nptl*)
+    nptl_missing=
+    ;;
+  *)
+    nptl_missing=yes
+    ;;
+esac
+
+if test "$nptl_missing"; then
+  if test $enable_sanity = yes; then
+    echo "\
+*** On GNU/Linux systems it is normal to compile GNU libc with the
+*** \`nptl' add-on.  Without that, the library will be
+*** incompatible with normal GNU/Linux systems.
+*** If you really mean to not use this add-on, run configure again
+*** using the extra parameter \`--disable-sanity-checks'."
+    exit 1
+  else
+    echo "\
+*** WARNING: Are you sure you do not want to use the \`nptl'
+*** add-on?"
+  fi
+fi
+
 if test "$prefix" = "/usr/local" -o "$prefix" = "/usr/local/" -o "$prefix" = "NONE"; then
   if test $enable_sanity = yes; then
     echo "\