?RCS: $Id: d_gnulibc.U 167 2013-05-08 17:58:00Z rmanfredi $
?RCS:
?RCS: Copyright (c) 1996,1998 Andy Dougherty
?RCS: Copyright (c) 1996, Sven Verdoolaege
?RCS: Copyright (c) 1991-1997, 2004-2006, Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic License,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic License; a copy of which may be found at the root
?RCS: of the source tree for dist 4.0.
?RCS:
?MAKE:d_gnulibc gnulibc_version: Myread Oldconfig Setvar rm \
	cat Compile run
?MAKE:	-pick add $@ %<
?S:d_gnulibc:
?S:	Defined if we're dealing with the GNU C Library.
?S:.
?S:gnulibc_version:
?S:	This variable contains the version number of the GNU C library.
?S:	It is usually something like '2.2.5'.  It is a plain '' if this
?S:	is not the GNU C library, or if the version is unknown.
?S:.
?C:HAS_GNULIBC ~ %<:
?C:	This symbol, if defined, indicates to the C program that 
?C:	the GNU C library is being used.  A better check is to use
?C:	the __GLIBC__ and __GLIBC_MINOR__ symbols supplied with glibc.
?C:.
?H:?%<:#$d_gnulibc HAS_GNULIBC  	/**/
?H:?%<:#if defined(HAS_GNULIBC) && !defined(_GNU_SOURCE)
?H:?%<:#define _GNU_SOURCE
?H:?%<:#endif
?H:.
?F:!glibc.ver !try.c !try
?LINT: set d_gnulibc
?LINT: usefile try.c
?LINT: known _GNU_SOURCE
?X:	gnulibc can be executed by calling __libc_main().
?X:	Ulrich Drepper doesn't think any other libc does that,
?X:	but we check if it says 'GNU C Library' to be sure.
?X:
?X: Alas, as of 3/1998 glibc 2.0.7 reportedly isn't going to
?X: have __libc_main() anymore. :-(.  Fortunately, all released
?X: versions of glibc 2.x.x _do_ have CPP variables.  For 2.0.6,
?X: they are:
?X: #define	__GLIBC__  2
?X: #define__GLIBC_MINOR__ 0.
?X: (The '6' isn't available :-(.
?X: glibc2.1 will also have 
?X:		extern const char * __gnu_get_libc_release(void);
?X:		extern const char * __gnu_get_libc_version(void);
?X: functions.   --thanks to Andreas Jaeger.   --AD  6/1998.
?X: Although the exact format isn't documented, __gnu_get_libc_version()
?X: returns a simple string '2.1.3' in glibc 2.1.3.
?X:
: determine whether we are using a GNU C library
echo " "
echo "Checking for GNU C Library..." >&4
cat >try.c <<'EOCP'
/* Find out version of GNU C library.  __GLIBC__ and __GLIBC_MINOR__
   alone are insufficient to distinguish different versions, such as
   2.0.6 and 2.0.7.  The function gnu_get_libc_version() appeared in
   libc version 2.1.0.      A. Dougherty,  June 3, 2002.
*/
#include <stdio.h>
int main(void)
{
#ifdef __GLIBC__
#   ifdef __GLIBC_MINOR__
#       if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1
#           include <gnu/libc-version.h>
	    printf("%s\n",  gnu_get_libc_version());
#       else
	    printf("%d.%d\n",  __GLIBC__, __GLIBC_MINOR__);
#       endif
#   else
	printf("%d\n",  __GLIBC__);
#   endif
    return 0;
#else
    return 1;
#endif
}
EOCP
set try
if eval $compile_ok && $run ./try > glibc.ver; then
	val="$define"
	gnulibc_version=`$cat glibc.ver`
	echo "You are using the GNU C Library version $gnulibc_version"
else
	val="$undef"
	gnulibc_version=''
	echo "You are not using the GNU C Library"
fi
$rm -f try try.* glibc.ver
set d_gnulibc
eval $setvar