From: Matthias Klose <doko@gcc.gnu.org>
Date: Tue, 15 Nov 2016 17:27:39 +0000 (+0000)
Subject: - Revert last commit, restore the regenerated files aclocal.m4 and configure
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2b60167833a09e3632b44b6770f7fef1d602dfe9;p=gcc.git

- Revert last commit, restore the regenerated files aclocal.m4 and configure

From-SVN: r242438
---

diff --git a/libiberty/aclocal.m4 b/libiberty/aclocal.m4
index 47238fd1bf4..bf8a907100f 100644
--- a/libiberty/aclocal.m4
+++ b/libiberty/aclocal.m4
@@ -1,19 +1,175 @@
-# generated automatically by aclocal 1.11.6 -*- Autoconf -*-
-
-# Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-# 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation,
-# Inc.
-# This file is free software; the Free Software Foundation
-# gives unlimited permission to copy and/or distribute it,
-# with or without modifications, as long as this notice is preserved.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
-# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
-# PARTICULAR PURPOSE.
-
-m4_include([../config/acx.m4])
-m4_include([../config/no-executables.m4])
-m4_include([../config/override.m4])
-m4_include([../config/picflag.m4])
-m4_include([../config/warnings.m4])
+sinclude(../config/acx.m4)
+sinclude(../config/no-executables.m4)
+sinclude(../config/override.m4)
+sinclude(../config/picflag.m4)
+sinclude(../config/warnings.m4)
+
+dnl See whether strncmp reads past the end of its string parameters.
+dnl On some versions of SunOS4 at least, strncmp reads a word at a time
+dnl but erroneously reads past the end of strings.  This can cause
+dnl a SEGV in some cases.
+AC_DEFUN(libiberty_AC_FUNC_STRNCMP,
+[AC_REQUIRE([AC_FUNC_MMAP])
+AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,
+[AC_TRY_RUN([
+/* Test by Jim Wilson and Kaveh Ghazi.
+   Check whether strncmp reads past the end of its string parameters. */
+#include <sys/types.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifndef MAP_ANON
+#ifdef MAP_ANONYMOUS
+#define MAP_ANON MAP_ANONYMOUS
+#else
+#define MAP_ANON MAP_FILE
+#endif
+#endif
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+
+#define MAP_LEN 0x10000
+
+main ()
+{
+#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
+  char *p;
+  int dev_zero;
+
+  dev_zero = open ("/dev/zero", O_RDONLY);
+  if (dev_zero < 0)
+    exit (1);
+  
+  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		     MAP_ANON|MAP_PRIVATE, dev_zero, 0);
+  if (p == (char *)-1)
+    p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		       MAP_ANON|MAP_PRIVATE, -1, 0);
+  if (p == (char *)-1)
+    exit (2);
+  else
+    {
+      char *string = "__si_type_info";
+      char *q = (char *) p + MAP_LEN - strlen (string) - 2;
+      char *r = (char *) p + 0xe;
+
+      strcpy (q, string);
+      strcpy (r, string);
+      strncmp (r, q, 14);
+    }
+#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
+  exit (0);
+}
+], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,
+  ac_cv_func_strncmp_works=yes)
+rm -f core core.* *.core])
+if test $ac_cv_func_strncmp_works = no ; then
+  AC_LIBOBJ([strncmp])
+fi
+])
+
+dnl See if errno must be declared even when <errno.h> is included.
+AC_DEFUN(libiberty_AC_DECLARE_ERRNO,
+[AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno,
+[AC_TRY_COMPILE(
+[#include <errno.h>],
+[int x = errno;],
+libiberty_cv_declare_errno=no,
+libiberty_cv_declare_errno=yes)])
+if test $libiberty_cv_declare_errno = yes
+then AC_DEFINE(NEED_DECLARATION_ERRNO, 1,
+  [Define if errno must be declared even when <errno.h> is included.])
+fi
+])
+
+dnl See whether we need a declaration for a function.
+AC_DEFUN(libiberty_NEED_DECLARATION,
+[AC_MSG_CHECKING([whether $1 must be declared])
+AC_CACHE_VAL(libiberty_cv_decl_needed_$1,
+[AC_TRY_COMPILE([
+#include "confdefs.h"
+#include <stdio.h>
+#ifdef HAVE_STRING_H
+#include <string.h>
+#else
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif],
+[char *(*pfn) = (char *(*)) $1],
+libiberty_cv_decl_needed_$1=no, libiberty_cv_decl_needed_$1=yes)])
+AC_MSG_RESULT($libiberty_cv_decl_needed_$1)
+if test $libiberty_cv_decl_needed_$1 = yes; then
+  AC_DEFINE([NEED_DECLARATION_]translit($1, [a-z], [A-Z]), 1,
+            [Define if $1 is not declared in system header files.])
+fi
+])dnl
+
+# We always want a C version of alloca() compiled into libiberty,
+# because native-compiler support for the real alloca is so !@#$%
+# unreliable that GCC has decided to use it only when being compiled
+# by GCC.  This is the part of AC_FUNC_ALLOCA that calculates the
+# information alloca.c needs.
+AC_DEFUN(libiberty_AC_FUNC_C_ALLOCA,
+[AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray,
+[AC_EGREP_CPP(webecray,
+[#if defined(CRAY) && ! defined(CRAY2)
+webecray
+#else
+wenotbecray
+#endif
+], ac_cv_os_cray=yes, ac_cv_os_cray=no)])
+if test $ac_cv_os_cray = yes; then
+  for ac_func in _getb67 GETB67 getb67; do
+    AC_CHECK_FUNC($ac_func, 
+      [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func, 
+  [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP
+   systems. This function is required for alloca.c support on those
+   systems.])  break])
+  done
+fi
+
+AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction,
+[AC_TRY_RUN([find_stack_direction ()
+{
+  static char *addr = 0;
+  auto char dummy;
+  if (addr == 0)
+    {
+      addr = &dummy;
+      return find_stack_direction ();
+    }
+  else
+    return (&dummy > addr) ? 1 : -1;
+}
+main ()
+{
+  exit (find_stack_direction() < 0);
+}], 
+  ac_cv_c_stack_direction=1,
+  ac_cv_c_stack_direction=-1,
+  ac_cv_c_stack_direction=0)])
+AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction,
+  [Define if you know the direction of stack growth for your system;
+   otherwise it will be automatically deduced at run-time.
+        STACK_DIRECTION > 0 => grows toward higher addresses
+        STACK_DIRECTION < 0 => grows toward lower addresses
+        STACK_DIRECTION = 0 => direction of growth unknown])
+])
diff --git a/libiberty/configure b/libiberty/configure
index a94db6afb03..5c4dda5d1d5 100755
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -5112,6 +5112,10 @@ case "${host}" in
 	;;
     i[34567]86-*-mingw* | x86_64-*-mingw*)
 	;;
+    i[34567]86-*-interix[3-9]*)
+	# Interix 3.x gcc -fpic/-fPIC options generate broken code.
+	# Instead, we relocate shared libraries at runtime.
+	;;
     i[34567]86-*-nto-qnx*)
 	# QNX uses GNU C++, but need to define -shared option too, otherwise
 	# it will coredump.
@@ -5300,7 +5304,37 @@ $as_echo "#define TIME_WITH_SYS_TIME 1" >>confdefs.h
 fi
 
 
-libiberty_AC_DECLARE_ERRNO
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether errno must be declared" >&5
+$as_echo_n "checking whether errno must be declared... " >&6; }
+if test "${libiberty_cv_declare_errno+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <errno.h>
+int
+main ()
+{
+int x = errno;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  libiberty_cv_declare_errno=no
+else
+  libiberty_cv_declare_errno=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libiberty_cv_declare_errno" >&5
+$as_echo "$libiberty_cv_declare_errno" >&6; }
+if test $libiberty_cv_declare_errno = yes
+then
+$as_echo "#define NEED_DECLARATION_ERRNO 1" >>confdefs.h
+
+fi
+
 
 # Determine sizes of some types.
 # The cast to long int works around a bug in the HP C Compiler
@@ -6369,7 +6403,92 @@ fi
 done
 
 
-  libiberty_AC_FUNC_C_ALLOCA
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether alloca needs Cray hooks" >&5
+$as_echo_n "checking whether alloca needs Cray hooks... " >&6; }
+if test "${ac_cv_os_cray+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#if defined(CRAY) && ! defined(CRAY2)
+webecray
+#else
+wenotbecray
+#endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+  $EGREP "webecray" >/dev/null 2>&1; then :
+  ac_cv_os_cray=yes
+else
+  ac_cv_os_cray=no
+fi
+rm -f conftest*
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_os_cray" >&5
+$as_echo "$ac_cv_os_cray" >&6; }
+if test $ac_cv_os_cray = yes; then
+  for ac_func in _getb67 GETB67 getb67; do
+    as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+eval as_val=\$$as_ac_var
+   if test "x$as_val" = x""yes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define CRAY_STACKSEG_END $ac_func
+_ACEOF
+  break
+fi
+
+  done
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking stack direction for C alloca" >&5
+$as_echo_n "checking stack direction for C alloca... " >&6; }
+if test "${ac_cv_c_stack_direction+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  ac_cv_c_stack_direction=0
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+find_stack_direction ()
+{
+  static char *addr = 0;
+  auto char dummy;
+  if (addr == 0)
+    {
+      addr = &dummy;
+      return find_stack_direction ();
+    }
+  else
+    return (&dummy > addr) ? 1 : -1;
+}
+main ()
+{
+  exit (find_stack_direction() < 0);
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ac_cv_c_stack_direction=1
+else
+  ac_cv_c_stack_direction=-1
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_stack_direction" >&5
+$as_echo "$ac_cv_c_stack_direction" >&6; }
+
+cat >>confdefs.h <<_ACEOF
+#define STACK_DIRECTION $ac_cv_c_stack_direction
+_ACEOF
+
+
   for ac_header in vfork.h
 do :
   ac_fn_c_check_header_preproc "$LINENO" "vfork.h" "ac_cv_header_vfork_h"
@@ -6885,7 +7004,53 @@ cat >>confdefs.h <<_ACEOF
 #define HAVE_DECL_STRVERSCMP $ac_have_decl
 _ACEOF
 
-  libiberty_NEED_DECLARATION(canonicalize_file_name)
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether canonicalize_file_name must be declared" >&5
+$as_echo_n "checking whether canonicalize_file_name must be declared... " >&6; }
+if test "${libiberty_cv_decl_needed_canonicalize_file_name+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+#include "confdefs.h"
+#include <stdio.h>
+#ifdef HAVE_STRING_H
+#include <string.h>
+#else
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+int
+main ()
+{
+char *(*pfn) = (char *(*)) canonicalize_file_name
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  libiberty_cv_decl_needed_canonicalize_file_name=no
+else
+  libiberty_cv_decl_needed_canonicalize_file_name=yes
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libiberty_cv_decl_needed_canonicalize_file_name" >&5
+$as_echo "$libiberty_cv_decl_needed_canonicalize_file_name" >&6; }
+if test $libiberty_cv_decl_needed_canonicalize_file_name = yes; then
+
+$as_echo "#define NEED_DECLARATION_CANONICALIZE_FILE_NAME 1" >>confdefs.h
+
+fi
+
 fi
 
 # Figure out which version of pexecute to use.
@@ -6897,7 +7062,288 @@ case "${host}" in
 esac
 
 
-libiberty_AC_FUNC_STRNCMP
+if test x$gcc_no_link = xyes; then
+  if test "x${ac_cv_func_mmap_fixed_mapped+set}" != xset; then
+    ac_cv_func_mmap_fixed_mapped=no
+  fi
+fi
+if test "x${ac_cv_func_mmap_fixed_mapped}" != xno; then
+  for ac_header in stdlib.h unistd.h
+do :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_preproc "$LINENO" "$ac_header" "$as_ac_Header"
+eval as_val=\$$as_ac_Header
+   if test "x$as_val" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+for ac_func in getpagesize
+do :
+  ac_fn_c_check_func "$LINENO" "getpagesize" "ac_cv_func_getpagesize"
+if test "x$ac_cv_func_getpagesize" = x""yes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_GETPAGESIZE 1
+_ACEOF
+
+fi
+done
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for working mmap" >&5
+$as_echo_n "checking for working mmap... " >&6; }
+if test "${ac_cv_func_mmap_fixed_mapped+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  ac_cv_func_mmap_fixed_mapped=no
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$ac_includes_default
+/* malloc might have been renamed as rpl_malloc. */
+#undef malloc
+
+/* 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
+   propagated 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 !defined STDC_HEADERS && !defined HAVE_STDLIB_H
+char *malloc ();
+#endif
+
+/* This mess was copied from the GNU getpagesize.h.  */
+#ifndef HAVE_GETPAGESIZE
+/* Assume that all systems that can run configure have sys/param.h.  */
+# ifndef HAVE_SYS_PARAM_H
+#  define HAVE_SYS_PARAM_H 1
+# endif
+
+# ifdef _SC_PAGESIZE
+#  define getpagesize() sysconf(_SC_PAGESIZE)
+# else /* no _SC_PAGESIZE */
+#  ifdef 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)
+    return 1;
+  for (i = 0; i < pagesize; ++i)
+    *(data + i) = rand ();
+  umask (0);
+  fd = creat ("conftest.mmap", 0600);
+  if (fd < 0)
+    return 1;
+  if (write (fd, data, pagesize) != pagesize)
+    return 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)
+    return 1;
+  data2 = (char *) malloc (2 * pagesize);
+  if (!data2)
+    return 1;
+  data2 += (pagesize - ((long int) data2 & (pagesize - 1))) & (pagesize - 1);
+  if (data2 != mmap (data2, pagesize, PROT_READ | PROT_WRITE,
+		     MAP_PRIVATE | MAP_FIXED, fd, 0L))
+    return 1;
+  for (i = 0; i < pagesize; ++i)
+    if (*(data + i) != *(data2 + i))
+      return 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)
+    return 1;
+  if (read (fd, data3, pagesize) != pagesize)
+    return 1;
+  for (i = 0; i < pagesize; ++i)
+    if (*(data + i) != *(data3 + i))
+      return 1;
+  close (fd);
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ac_cv_func_mmap_fixed_mapped=yes
+else
+  ac_cv_func_mmap_fixed_mapped=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_mmap_fixed_mapped" >&5
+$as_echo "$ac_cv_func_mmap_fixed_mapped" >&6; }
+if test $ac_cv_func_mmap_fixed_mapped = yes; then
+
+$as_echo "#define HAVE_MMAP 1" >>confdefs.h
+
+fi
+rm -f conftest.mmap
+
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for working strncmp" >&5
+$as_echo_n "checking for working strncmp... " >&6; }
+if test "${ac_cv_func_strncmp_works+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  ac_cv_func_strncmp_works=yes
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Test by Jim Wilson and Kaveh Ghazi.
+   Check whether strncmp reads past the end of its string parameters. */
+#include <sys/types.h>
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+
+#ifndef MAP_ANON
+#ifdef MAP_ANONYMOUS
+#define MAP_ANON MAP_ANONYMOUS
+#else
+#define MAP_ANON MAP_FILE
+#endif
+#endif
+
+#ifndef MAP_FILE
+#define MAP_FILE 0
+#endif
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+
+#define MAP_LEN 0x10000
+
+main ()
+{
+#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
+  char *p;
+  int dev_zero;
+
+  dev_zero = open ("/dev/zero", O_RDONLY);
+  if (dev_zero < 0)
+    exit (1);
+
+  p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		     MAP_ANON|MAP_PRIVATE, dev_zero, 0);
+  if (p == (char *)-1)
+    p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
+		       MAP_ANON|MAP_PRIVATE, -1, 0);
+  if (p == (char *)-1)
+    exit (2);
+  else
+    {
+      char *string = "__si_type_info";
+      char *q = (char *) p + MAP_LEN - strlen (string) - 2;
+      char *r = (char *) p + 0xe;
+
+      strcpy (q, string);
+      strcpy (r, string);
+      strncmp (r, q, 14);
+    }
+#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
+  exit (0);
+}
+
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ac_cv_func_strncmp_works=yes
+else
+  ac_cv_func_strncmp_works=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+rm -f core core.* *.core
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_func_strncmp_works" >&5
+$as_echo "$ac_cv_func_strncmp_works" >&6; }
+if test $ac_cv_func_strncmp_works = no ; then
+  case " $LIBOBJS " in
+  *" strncmp.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS strncmp.$ac_objext"
+ ;;
+esac
+
+fi
+
 
 # Install a library built with a cross compiler in $(tooldir) rather
 # than $(libdir).