Another step towards detecting if _REENTRANT is already defined or actually

needed, and being able to define it if appropriate for further configure tests
as well as for the generated config file.

Introduced reentrant.m4 intended for our reentrant related autotools/m4 macros.

1 files changed, 868 insertions, 0 deletions

diff --git a/reentrant.m4 b/reentrant.m4
new file mode 100644
index 000000000..f72bb7a21
--- /dev/null
+++ b/reentrant.m4
@@ -0,0 +1,868 @@
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+# $Id$
+###########################################################################
+
+
+dnl CHECK_NEED_REENTRANT_STRERROR_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function strerror_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_STRERROR_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([strerror_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: strerror_r links... yes])
+    tmp_strerror_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: strerror_r links... no])
+    tmp_strerror_r="no"
+  ])
+  #
+  if test "$tmp_strerror_r" = "yes"; then
+    AC_EGREP_CPP([strerror_r],[
+#include <sys/types.h>
+#include <string.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: strerror_r proto... without our definition])
+      tmp_strerror_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([strerror_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <string.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: strerror_r proto... with our _reentrant])
+        tmp_strerror_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: strerror_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_strerror_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <string.h>
+      ]],[[
+        strerror_r(0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: strerror_r proto wout finds... 3 args])
+      tmp_strerror_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_strerror_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <string.h>
+      ]],[[
+        strerror_r(0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: strerror_r proto with finds... 3 args])
+      tmp_strerror_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_strerror_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_LOCALTIME_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function localtime_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_LOCALTIME_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([localtime_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: localtime_r links... yes])
+    tmp_localtime_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: localtime_r links... no])
+    tmp_localtime_r="no"
+  ])
+  #
+  if test "$tmp_localtime_r" = "yes"; then
+    AC_EGREP_CPP([localtime_r],[
+#include <sys/types.h>
+#include <time.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: localtime_r proto... without our definition])
+      tmp_localtime_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([localtime_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <time.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: localtime_r proto... with our _reentrant])
+        tmp_localtime_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: localtime_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_localtime_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <time.h>
+      ]],[[
+        localtime_r(0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: localtime_r proto wout finds... 2 args])
+      tmp_localtime_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_localtime_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <time.h>
+      ]],[[
+        localtime_r(0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: localtime_r proto with finds... 2 args])
+      tmp_localtime_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_localtime_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_GMTIME_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function gmtime_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_GMTIME_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gmtime_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: gmtime_r links... yes])
+    tmp_gmtime_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: gmtime_r links... no])
+    tmp_gmtime_r="no"
+  ])
+  #
+  if test "$tmp_gmtime_r" = "yes"; then
+    AC_EGREP_CPP([gmtime_r],[
+#include <sys/types.h>
+#include <time.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: gmtime_r proto... without our definition])
+      tmp_gmtime_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([gmtime_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <time.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: gmtime_r proto... with our _reentrant])
+        tmp_gmtime_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: gmtime_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_gmtime_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <time.h>
+      ]],[[
+        gmtime_r(0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gmtime_r proto wout finds... 2 args])
+      tmp_gmtime_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_gmtime_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <time.h>
+      ]],[[
+        gmtime_r(0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gmtime_r proto with finds... 2 args])
+      tmp_gmtime_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_gmtime_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_INET_NTOA_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function inet_ntoa_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_INET_NTOA_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([inet_ntoa_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: inet_ntoa_r links... yes])
+    tmp_inet_ntoa_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: inet_ntoa_r links... no])
+    tmp_inet_ntoa_r="no"
+  ])
+  #
+  if test "$tmp_inet_ntoa_r" = "yes"; then
+    AC_EGREP_CPP([inet_ntoa_r],[
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto... without our definition])
+      tmp_inet_ntoa_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([inet_ntoa_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto... with our _reentrant])
+        tmp_inet_ntoa_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_inet_ntoa_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+      ]],[[
+        struct in_addr addr;
+        inet_ntoa_r(addr, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto wout finds... 2 args])
+      tmp_inet_ntoa_r="done"
+    ])
+  fi
+  if test "$tmp_inet_ntoa_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+      ]],[[
+        struct in_addr addr;
+        inet_ntoa_r(addr, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto wout finds... 3 args])
+      tmp_inet_ntoa_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_inet_ntoa_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+      ]],[[
+        struct in_addr addr;
+        inet_ntoa_r(addr, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto with finds... 2 args])
+      tmp_inet_ntoa_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_inet_ntoa_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+      ]],[[
+        struct in_addr addr;
+        inet_ntoa_r(addr, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: inet_ntoa_r proto with finds... 3 args])
+      tmp_inet_ntoa_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_inet_ntoa_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_GETHOSTBYADDR_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function gethostbyaddr_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_GETHOSTBYADDR_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gethostbyaddr_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: gethostbyaddr_r links... yes])
+    tmp_gethostbyaddr_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: gethostbyaddr_r links... no])
+    tmp_gethostbyaddr_r="no"
+  ])
+  #
+  if test "$tmp_gethostbyaddr_r" = "yes"; then
+    AC_EGREP_CPP([gethostbyaddr_r],[
+#include <sys/types.h>
+#include <netdb.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto... without our definition])
+      tmp_gethostbyaddr_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([gethostbyaddr_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto... with our _reentrant])
+        tmp_gethostbyaddr_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyaddr_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto wout finds... 5 args])
+      tmp_gethostbyaddr_r="done"
+    ])
+  fi
+  if test "$tmp_gethostbyaddr_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto wout finds... 7 args])
+      tmp_gethostbyaddr_r="done"
+    ])
+  fi
+  if test "$tmp_gethostbyaddr_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto wout finds... 8 args])
+      tmp_gethostbyaddr_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyaddr_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto with finds... 5 args])
+      tmp_gethostbyaddr_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_gethostbyaddr_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto with finds... 7 args])
+      tmp_gethostbyaddr_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_gethostbyaddr_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyaddr_r(0, 0, 0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyaddr_r proto with finds... 8 args])
+      tmp_gethostbyaddr_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyaddr_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_GETHOSTBYNAME_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function gethostbyname_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_GETHOSTBYNAME_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([gethostbyname_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: gethostbyname_r links... yes])
+    tmp_gethostbyname_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: gethostbyname_r links... no])
+    tmp_gethostbyname_r="no"
+  ])
+  #
+  if test "$tmp_gethostbyname_r" = "yes"; then
+    AC_EGREP_CPP([gethostbyname_r],[
+#include <sys/types.h>
+#include <netdb.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto... without our definition])
+      tmp_gethostbyname_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([gethostbyname_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: gethostbyname_r proto... with our _reentrant])
+        tmp_gethostbyname_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: gethostbyname_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyname_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto wout finds... 3 args])
+      tmp_gethostbyname_r="done"
+    ])
+  fi
+  if test "$tmp_gethostbyname_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto wout finds... 5 args])
+      tmp_gethostbyname_r="done"
+    ])
+  fi
+  if test "$tmp_gethostbyname_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto wout finds... 6 args])
+      tmp_gethostbyname_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyname_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto with finds... 3 args])
+      tmp_gethostbyname_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_gethostbyname_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto with finds... 5 args])
+      tmp_gethostbyname_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_gethostbyname_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        gethostbyname_r(0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: gethostbyname_r proto with finds... 6 args])
+      tmp_gethostbyname_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_gethostbyname_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_GETSERVBYPORT_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes function getservbyport_r compiler visible.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_GETSERVBYPORT_R], [
+  #
+  AC_MSG_NOTICE([DEBUG:])
+  AC_LINK_IFELSE([
+    AC_LANG_FUNC_LINK_TRY([getservbyport_r])
+  ],[
+    AC_MSG_NOTICE([DEBUG: getservbyport_r links... yes])
+    tmp_getservbyport_r="yes"
+  ],[
+    AC_MSG_NOTICE([DEBUG: getservbyport_r links... no])
+    tmp_getservbyport_r="no"
+  ])
+  #
+  if test "$tmp_getservbyport_r" = "yes"; then
+    AC_EGREP_CPP([getservbyport_r],[
+#include <sys/types.h>
+#include <netdb.h>
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto... without our definition])
+      tmp_getservbyport_r="proto_wout_def"
+    ],[
+      AC_EGREP_CPP([getservbyport_r],[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ],[
+        AC_MSG_NOTICE([DEBUG: getservbyport_r proto... with our _reentrant])
+        tmp_getservbyport_r="proto_with_def"
+      ],[
+        AC_MSG_NOTICE([DEBUG: getservbyport_r proto... not found])
+      ])
+    ])
+  fi
+  #
+  if test "$tmp_getservbyport_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto wout finds... 4 args])
+      tmp_getservbyport_r="done"
+    ])
+  fi
+  if test "$tmp_getservbyport_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto wout finds... 5 args])
+      tmp_getservbyport_r="done"
+    ])
+  fi
+  if test "$tmp_getservbyport_r" = "proto_wout_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto wout finds... 6 args])
+      tmp_getservbyport_r="done"
+    ])
+  fi
+  #
+  if test "$tmp_getservbyport_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto with finds... 4 args])
+      tmp_getservbyport_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_getservbyport_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto with finds... 5 args])
+      tmp_getservbyport_r="needs_reentrant"
+    ])
+  fi
+  if test "$tmp_getservbyport_r" = "proto_with_def"; then
+    AC_COMPILE_IFELSE([
+      AC_LANG_PROGRAM([[
+#define _REENTRANT
+#include <sys/types.h>
+#include <netdb.h>
+      ]],[[
+        getservbyport_r(0, 0, 0, 0, 0, 0);
+      ]])
+    ],[
+      AC_MSG_NOTICE([DEBUG: getservbyport_r proto with finds... 6 args])
+      tmp_getservbyport_r="needs_reentrant"
+    ])
+  fi
+  #
+  if test "$tmp_getservbyport_r" = "needs_reentrant"; then
+    ac_cv_need_reentrant="yes"
+  fi
+])
+
+
+dnl CHECK_NEED_REENTRANT_FUNCTIONS_R
+dnl -------------------------------------------------
+dnl Checks if the preprocessor _REENTRANT definition
+dnl makes several _r functions compiler visible.
+dnl Internal macro for CONFIGURE_REENTRANT.
+
+AC_DEFUN([CHECK_NEED_REENTRANT_FUNCTIONS_R], [
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_STRERROR_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_LOCALTIME_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_GMTIME_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_INET_NTOA_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_GETHOSTBYADDR_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_GETHOSTBYNAME_R
+  fi
+  if test "$ac_cv_need_reentrant" = "no"; then
+    CHECK_NEED_REENTRANT_GETSERVBYPORT_R
+  fi
+])
+
+AC_DEFUN([CHECK_NEED_REENTRANT_FUNCTIONS_R_DEBUG], [
+    CHECK_NEED_REENTRANT_STRERROR_R
+    CHECK_NEED_REENTRANT_LOCALTIME_R
+    CHECK_NEED_REENTRANT_GMTIME_R
+    CHECK_NEED_REENTRANT_INET_NTOA_R
+    CHECK_NEED_REENTRANT_GETHOSTBYADDR_R
+    CHECK_NEED_REENTRANT_GETHOSTBYNAME_R
+    CHECK_NEED_REENTRANT_GETSERVBYPORT_R
+])
+
+
+dnl CONFIGURE_FROM_NOW_ON_WITH_REENTRANT
+dnl -------------------------------------------------
+dnl This macro ensures that configuration tests done
+dnl after this will execute with preprocessor symbol
+dnl _REENTRANT defined. This macro also ensures that
+dnl the generated config file will equally define it.
+dnl Internal macro for CONFIGURE_REENTRANT.
+
+AC_DEFUN([CONFIGURE_FROM_NOW_ON_WITH_REENTRANT], [
+AH_VERBATIM([NEED_REENTRANT],
+[/* Configure process defines NEED_REENTRANT to 1 when it finds out that */
+/* _REENTRANT is required or already defined for proper configuration.  */
+@%:@undef NEED_REENTRANT
+@%:@if defined(NEED_REENTRANT) && !defined(_REENTRANT)
+@%:@ define _REENTRANT
+@%:@endif])
+cat >>confdefs.h <<_ACEOF
+[@%:@ifndef _REENTRANT
+@%:@ define _REENTRANT
+@%:@endif]
+_ACEOF
+AC_DEFINE(NEED_REENTRANT, 1, [])
+])
+
+
+dnl CONFIGURE_REENTRANT
+dnl -------------------------------------------------
+dnl This first checks if the preprocessor _REENTRANT
+dnl symbol is already defined. If it isn't currently
+dnl defined a set of checks are performed to verify
+dnl if its definition is required to make visible to
+dnl the compiler a set of *_r functions. Finally, if
+dnl _REENTRANT is already defined or needed it takes
+dnl care of making adjustments necessary to ensure
+dnl that it is defined equally for further configure
+dnl tests and generated config file.
+
+AC_DEFUN([CONFIGURE_REENTRANT], [
+  #
+  AC_MSG_CHECKING([if _REENTRANT is already defined])
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([[
+    ]],[[
+#ifdef _REENTRANT
+      int dummy=1;
+#else
+      force compilation error
+#endif
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    tmp_reentrant_initially_defined="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    tmp_reentrant_initially_defined="no"
+  ])
+  #
+  if test "$tmp_reentrant_initially_defined" = "no"; then
+    AC_MSG_CHECKING([if _REENTRANT is actually needed])
+    ac_cv_need_reentrant="no"
+    CHECK_NEED_REENTRANT_FUNCTIONS_R_DEBUG
+    if test "$ac_cv_need_reentrant" = "yes"; then
+      AC_MSG_RESULT([yes])
+    else
+      AC_MSG_RESULT([no])
+    fi
+  fi
+  #
+  AC_MSG_CHECKING([if _REENTRANT is onwards defined])
+  if test "$tmp_reentrant_initially_defined" = "yes" ||
+    test "$ac_cv_need_reentrant" = "yes"; then
+    CONFIGURE_FROM_NOW_ON_WITH_REENTRANT
+    AC_MSG_RESULT([yes])
+  else
+    AC_MSG_RESULT([no])
+  fi
+  #
+])
+