+ if test "$cross_compiling" = yes; then
+ ac_cv_func_mmap_fixed_mapped=no
+else
+ cat >conftest.$ac_ext <<_ACEOF
+#line 5844 "configure"
+#include "confdefs.h"
+$ac_includes_default
+/* Thanks to Mike Haertel and Jim Avera for this test.
+ Here is a matrix of mmap possibilities:
+ mmap private not fixed
+ mmap private fixed at somewhere currently unmapped
+ mmap private fixed at somewhere already mapped
+ mmap shared not fixed
+ mmap shared fixed at somewhere currently unmapped
+ mmap shared fixed at somewhere already mapped
+ For private mappings, we should verify that changes cannot be read()
+ back from the file, nor mmap's back from the file at a different
+ address. (There have been systems where private was not correctly
+ implemented like the infamous i386 svr4.0, and systems where the
+ VM page cache was not coherent with the file system buffer cache
+ like early versions of FreeBSD and possibly contemporary NetBSD.)
+ For shared mappings, we should conversely verify that changes get
+ propogated back to all the places they're supposed to be.
+
+ Grep wants private fixed already mapped.
+ The main things grep needs to know about mmap are:
+ * does it exist and is it safe to write into the mmap'd area
+ * how to use it (BSD variants) */
+
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#if !STDC_HEADERS && !HAVE_STDLIB_H
+char *malloc ();
+#endif
+
+/* This mess was copied from the GNU getpagesize.h. */
+#if !HAVE_GETPAGESIZE
+/* Assume that all systems that can run configure have sys/param.h. */
+# if !HAVE_SYS_PARAM_H
+# define HAVE_SYS_PARAM_H 1
+# endif
+
+# ifdef _SC_PAGESIZE
+# define getpagesize() sysconf(_SC_PAGESIZE)
+# else /* no _SC_PAGESIZE */
+# if HAVE_SYS_PARAM_H
+# include <sys/param.h>
+# ifdef EXEC_PAGESIZE
+# define getpagesize() EXEC_PAGESIZE
+# else /* no EXEC_PAGESIZE */
+# ifdef NBPG
+# define getpagesize() NBPG * CLSIZE
+# ifndef CLSIZE
+# define CLSIZE 1
+# endif /* no CLSIZE */
+# else /* no NBPG */
+# ifdef NBPC
+# define getpagesize() NBPC
+# else /* no NBPC */
+# ifdef PAGESIZE
+# define getpagesize() PAGESIZE
+# endif /* PAGESIZE */
+# endif /* no NBPC */
+# endif /* no NBPG */
+# endif /* no EXEC_PAGESIZE */
+# else /* no HAVE_SYS_PARAM_H */
+# define getpagesize() 8192 /* punt totally */
+# endif /* no HAVE_SYS_PARAM_H */
+# endif /* no _SC_PAGESIZE */
+
+#endif /* no HAVE_GETPAGESIZE */
+
+int
+main ()
+{
+ char *data, *data2, *data3;
+ int i, pagesize;
+ int fd;
+
+ pagesize = getpagesize ();
+
+ /* First, make a file with some known garbage in it. */
+ data = (char *) malloc (pagesize);
+ if (!data)
+ exit (1);
+ for (i = 0; i < pagesize; ++i)
+ *(data + i) = rand ();
+ umask (0);
+ fd = creat ("conftest.mmap", 0600);
+ if (fd < 0)
+ exit (1);
+ if (write (fd, data, pagesize) != pagesize)
+ exit (1);
+ close (fd);
+
+ /* Next, try to mmap the file at a fixed address which already has
+ something else allocated at it. If we can, also make sure that
+ we see the same garbage. */
+ fd = open ("conftest.mmap", O_RDWR);
+ if (fd < 0)
+ exit (1);
+ data2 = (char *) malloc (2 * pagesize);
+ if (!data2)
+ exit (1);
+ data2 += (pagesize - ((int) data2 & (pagesize - 1))) & (pagesize - 1);
+ if (data2 != mmap (data2, pagesize, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_FIXED, fd, 0L))
+ exit (1);
+ for (i = 0; i < pagesize; ++i)
+ if (*(data + i) != *(data2 + i))
+ exit (1);
+
+ /* Finally, make sure that changes to the mapped area do not
+ percolate back to the file as seen by read(). (This is a bug on
+ some variants of i386 svr4.0.) */
+ for (i = 0; i < pagesize; ++i)
+ *(data2 + i) = *(data2 + i) + 1;
+ data3 = (char *) malloc (pagesize);
+ if (!data3)
+ exit (1);
+ if (read (fd, data3, pagesize) != pagesize)
+ exit (1);
+ for (i = 0; i < pagesize; ++i)
+ if (*(data + i) != *(data3 + i))
+ exit (1);
+ close (fd);
+ exit (0);
+}
+_ACEOF
+rm -f conftest$ac_exeext
+if { (eval echo "$as_me:5971: \"$ac_link\"") >&5
+ (eval $ac_link) 2>&5
+ ac_status=$?
+ echo "$as_me:5974: \$? = $ac_status" >&5
+ (exit $ac_status); } && { ac_try='./conftest$ac_exeext'
+ { (eval echo "$as_me:5976: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:5979: \$? = $ac_status" >&5
+ (exit $ac_status); }; }; then
+ ac_cv_func_mmap_fixed_mapped=yes
+else
+ echo "$as_me: program exited with status $ac_status" >&5
+echo "$as_me: failed program was:" >&5
+cat conftest.$ac_ext >&5
+ac_cv_func_mmap_fixed_mapped=no
+fi
+rm -f core core.* *.core conftest$ac_exeext conftest.$ac_objext conftest.$ac_ext
+fi
+fi
+echo "$as_me:5991: result: $ac_cv_func_mmap_fixed_mapped" >&5
+echo "${ECHO_T}$ac_cv_func_mmap_fixed_mapped" >&6
+if test $ac_cv_func_mmap_fixed_mapped = yes; then
+
+cat >>confdefs.h <<\EOF
+#define HAVE_MMAP 1
+EOF
+
+fi
+rm -f conftest.mmap
+
+ echo "$as_me:6002: checking whether we are using the GNU C Library 2.1 or newer" >&5
+echo $ECHO_N "checking whether we are using the GNU C Library 2.1 or newer... $ECHO_C" >&6
+if test "${ac_cv_gnu_library_2_1+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+ cat >conftest.$ac_ext <<_ACEOF
+#line 6008 "configure"
+#include "confdefs.h"
+
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+ #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1) || (__GLIBC__ > 2)
+ Lucky GNU user
+ #endif
+#endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+ egrep "Lucky GNU user" >/dev/null 2>&1; then
+ ac_cv_gnu_library_2_1=yes
+else
+ ac_cv_gnu_library_2_1=no
+fi
+rm -f conftest*
+
+fi
+echo "$as_me:6028: result: $ac_cv_gnu_library_2_1" >&5
+echo "${ECHO_T}$ac_cv_gnu_library_2_1" >&6
+
+ GLIBC21="$ac_cv_gnu_library_2_1"
+
+for ac_header in argz.h limits.h locale.h nl_types.h malloc.h stddef.h \
+stdlib.h string.h unistd.h sys/param.h
+do
+as_ac_Header=`echo "ac_cv_header_$ac_header" | $as_tr_sh`
+echo "$as_me:6037: checking for $ac_header" >&5
+echo $ECHO_N "checking for $ac_header... $ECHO_C" >&6
+if eval "test \"\${$as_ac_Header+set}\" = set"; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+ cat >conftest.$ac_ext <<_ACEOF
+#line 6043 "configure"
+#include "confdefs.h"
+#include <$ac_header>
+_ACEOF
+if { (eval echo "$as_me:6047: \"$ac_cpp conftest.$ac_ext\"") >&5
+ (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1
+ ac_status=$?
+ egrep -v '^ *\+' conftest.er1 >conftest.err
+ rm -f conftest.er1
+ cat conftest.err >&5
+ echo "$as_me:6053: \$? = $ac_status" >&5
+ (exit $ac_status); } >/dev/null; then
+ if test -s conftest.err; then
+ ac_cpp_err=$ac_c_preproc_warn_flag
+ else
+ ac_cpp_err=
+ fi
+else
+ ac_cpp_err=yes
+fi
+if test -z "$ac_cpp_err"; then
+ eval "$as_ac_Header=yes"
+else
+ echo "$as_me: failed program was:" >&5
+ cat conftest.$ac_ext >&5
+ eval "$as_ac_Header=no"
+fi
+rm -f conftest.err conftest.$ac_ext
+fi
+echo "$as_me:6072: result: `eval echo '${'$as_ac_Header'}'`" >&5
+echo "${ECHO_T}`eval echo '${'$as_ac_Header'}'`" >&6
+if test `eval echo '${'$as_ac_Header'}'` = yes; then
+ cat >>confdefs.h <<EOF
+#define `echo "HAVE_$ac_header" | $as_tr_cpp` 1
+EOF
+
+fi
+done
+
+for ac_func in feof_unlocked fgets_unlocked getcwd getegid geteuid \
+getgid getuid mempcpy munmap putenv setenv setlocale stpcpy strchr strcasecmp \
+strdup strtoul tsearch __argz_count __argz_stringify __argz_next
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+echo "$as_me:6087: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6
+if eval "test \"\${$as_ac_var+set}\" = set"; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+ cat >conftest.$ac_ext <<_ACEOF
+#line 6093 "configure"