config/c-library.m4 - hawq - Git at Google

 # Macros that test various C library quirks
 # $PostgreSQL: pgsql/config/c-library.m4,v 1.33 2008/08/21 13:53:28 petere Exp $


 # PGAC_VAR_INT_TIMEZONE
 # ---------------------
 # Check if the global variable `timezone' exists. If so, define
 # HAVE_INT_TIMEZONE.
 AC_DEFUN([PGAC_VAR_INT_TIMEZONE],
 [AC_CACHE_CHECK(for int timezone, pgac_cv_var_int_timezone,
 [AC_TRY_LINK([#include <time.h>
 int res;],
   [#ifndef __CYGWIN__
 res = timezone / 60;
 #else
 res = _timezone / 60;
 #endif],
   [pgac_cv_var_int_timezone=yes],
   [pgac_cv_var_int_timezone=no])])
 if test x"$pgac_cv_var_int_timezone" = xyes ; then
   AC_DEFINE(HAVE_INT_TIMEZONE,, [Define to 1 if you have the global variable 'int timezone'.])
 fi])# PGAC_VAR_INT_TIMEZONE


 # PGAC_STRUCT_TIMEZONE
 # ------------------
 # Figure out how to get the current timezone.  If `struct tm' has a
 # `tm_zone' member, define `HAVE_TM_ZONE'.  Also, if the
 # external array `tzname' is found, define `HAVE_TZNAME'.
 # This is the same as the standard macro AC_STRUCT_TIMEZONE, except that
 # tzname[] is checked for regardless of whether we find tm_zone.
 AC_DEFUN([PGAC_STRUCT_TIMEZONE],
 [AC_REQUIRE([AC_STRUCT_TM])dnl
 AC_CHECK_MEMBERS([struct tm.tm_zone],,,[#include <sys/types.h>
 #include <$ac_cv_struct_tm>
 ])
 if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
   AC_DEFINE(HAVE_TM_ZONE, 1,
             [Define to 1 if your `struct tm' has `tm_zone'. Deprecated, use
              `HAVE_STRUCT_TM_TM_ZONE' instead.])
 fi
 AC_CACHE_CHECK(for tzname, ac_cv_var_tzname,
 [AC_TRY_LINK(
 [#include <time.h>
 #ifndef tzname /* For SGI.  */
 extern char *tzname[]; /* RS6000 and others reject char **tzname.  */
 #endif
 ],
 [atoi(*tzname);], ac_cv_var_tzname=yes, ac_cv_var_tzname=no)])
 if test $ac_cv_var_tzname = yes; then
     AC_DEFINE(HAVE_TZNAME, 1,
               [Define to 1 if you have the external array `tzname'.])
 fi
 ])# PGAC_STRUCT_TIMEZONE


 # PGAC_FUNC_GETTIMEOFDAY_1ARG
 # ---------------------------
 # Check if gettimeofday() has only one arguments. (Normal is two.)
 # If so, define GETTIMEOFDAY_1ARG.
 AC_DEFUN([PGAC_FUNC_GETTIMEOFDAY_1ARG],
 [AC_CACHE_CHECK(whether gettimeofday takes only one argument,
 pgac_cv_func_gettimeofday_1arg,
 [AC_TRY_COMPILE([#include <sys/time.h>],
 [struct timeval *tp;
 struct timezone *tzp;
 gettimeofday(tp,tzp);],
 [pgac_cv_func_gettimeofday_1arg=no],
 [pgac_cv_func_gettimeofday_1arg=yes])])
 if test x"$pgac_cv_func_gettimeofday_1arg" = xyes ; then
   AC_DEFINE(GETTIMEOFDAY_1ARG,, [Define to 1 if gettimeofday() takes only 1 argument.])
 fi
 AH_VERBATIM(GETTIMEOFDAY_1ARG_,
 [@%:@ifdef GETTIMEOFDAY_1ARG
 @%:@ define gettimeofday(a,b) gettimeofday(a)
 @%:@endif])dnl
 ])# PGAC_FUNC_GETTIMEOFDAY_1ARG


 # PGAC_FUNC_GETPWUID_R_5ARG
 # ---------------------------
 # Check if getpwuid_r() takes a fifth argument (later POSIX standard, not draft version)
 # If so, define GETPWUID_R_5ARG
 AC_DEFUN([PGAC_FUNC_GETPWUID_R_5ARG],
 [AC_CACHE_CHECK(whether getpwuid_r takes a fifth argument,
 pgac_cv_func_getpwuid_r_5arg,
 [AC_TRY_COMPILE([#include <sys/types.h>
 #include <pwd.h>],
 [uid_t uid;
 struct passwd *space;
 char *buf;
 size_t bufsize;
 struct passwd **result;
 getpwuid_r(uid, space, buf, bufsize, result);],
 [pgac_cv_func_getpwuid_r_5arg=yes],
 [pgac_cv_func_getpwuid_r_5arg=no])])
 if test x"$pgac_cv_func_getpwuid_r_5arg" = xyes ; then
   AC_DEFINE(GETPWUID_R_5ARG,, [Define to 1 if getpwuid_r() takes a 5th argument.])
 fi
 ])# PGAC_FUNC_GETPWUID_R_5ARG


 # PGAC_FUNC_STRERROR_R_INT
 # ---------------------------
 # Check if strerror_r() returns an int (SUSv3) rather than a char * (GNU libc)
 # If so, define STRERROR_R_INT
 AC_DEFUN([PGAC_FUNC_STRERROR_R_INT],
 [AC_CACHE_CHECK(whether strerror_r returns int,
 pgac_cv_func_strerror_r_int,
 [AC_TRY_COMPILE([#include <string.h>],
 [#ifndef _AIX
 int strerror_r(int, char *, size_t);
 #else
 /* Older AIX has 'int' for the third argument so we don't test the args. */
 int strerror_r();
 #endif],
 [pgac_cv_func_strerror_r_int=yes],
 [pgac_cv_func_strerror_r_int=no])])
 if test x"$pgac_cv_func_strerror_r_int" = xyes ; then
   AC_DEFINE(STRERROR_R_INT,, [Define to 1 if strerror_r() returns a int.])
 fi
 ])# PGAC_FUNC_STRERROR_R_INT


 # PGAC_UNION_SEMUN
 # ----------------
 # Check if `union semun' exists. Define HAVE_UNION_SEMUN if so.
 # If it doesn't then one could define it as
 # union semun { int val; struct semid_ds *buf; unsigned short *array; }
 AC_DEFUN([PGAC_UNION_SEMUN],
 [AC_CHECK_TYPES([union semun], [], [],
 [#include <sys/types.h>
 #include <sys/ipc.h>
 #include <sys/sem.h>])])# PGAC_UNION_SEMUN


 # PGAC_STRUCT_SOCKADDR_UN
 # -----------------------
 # If `struct sockaddr_un' exists, define HAVE_UNIX_SOCKETS.
 # (Requires test for <sys/un.h>!)
 AC_DEFUN([PGAC_STRUCT_SOCKADDR_UN],
 [AC_CHECK_TYPES([struct sockaddr_un], [AC_DEFINE(HAVE_UNIX_SOCKETS, 1, [Define to 1 if you have unix sockets.])], [],
 [#include <sys/types.h>
 #ifdef HAVE_SYS_UN_H
 #include <sys/un.h>
 #endif
 ])])# PGAC_STRUCT_SOCKADDR_UN


 # PGAC_STRUCT_SOCKADDR_STORAGE
 # ----------------------------
 # If `struct sockaddr_storage' exists, define HAVE_STRUCT_SOCKADDR_STORAGE.
 # If it is missing then one could define it.
 AC_DEFUN([PGAC_STRUCT_SOCKADDR_STORAGE],
 [AC_CHECK_TYPES([struct sockaddr_storage], [], [],
 [#include <sys/types.h>
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif
 ])])# PGAC_STRUCT_SOCKADDR_STORAGE

 # PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS
 # --------------------------------------
 # Check the members of `struct sockaddr_storage'.  We need to know about
 # ss_family and ss_len.  (Some platforms follow RFC 2553 and call them
 # __ss_family and __ss_len.)  We also check struct sockaddr's sa_len;
 # if we have to define our own `struct sockaddr_storage', this tells us
 # whether we need to provide an ss_len field.
 AC_DEFUN([PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS],
 [AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family,
 		   struct sockaddr_storage.__ss_family,
 		   struct sockaddr_storage.ss_len,
 		   struct sockaddr_storage.__ss_len,
 		   struct sockaddr.sa_len], [], [],
 [#include <sys/types.h>
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif
 ])])# PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS


 # PGAC_STRUCT_ADDRINFO
 # -----------------------
 # If `struct addrinfo' exists, define HAVE_STRUCT_ADDRINFO.
 AC_DEFUN([PGAC_STRUCT_ADDRINFO],
 [AC_CHECK_TYPES([struct addrinfo], [], [],
 [#include <sys/types.h>
 #include <sys/socket.h>
 #include <netdb.h>
 ])])# PGAC_STRUCT_ADDRINFO


 # PGAC_FUNC_POSIX_SIGNALS
 # -----------------------
 # Check to see if the machine has the POSIX signal interface. Define
 # HAVE_POSIX_SIGNALS if so. Also set the output variable HAVE_POSIX_SIGNALS
 # to yes or no.
 #
 # Note that this test only compiles a test program, it doesn't check
 # whether the routines actually work. If that becomes a problem, make
 # a fancier check.
 AC_DEFUN([PGAC_FUNC_POSIX_SIGNALS],
 [AC_CACHE_CHECK(for POSIX signal interface, pgac_cv_func_posix_signals,
 [AC_TRY_LINK([#include <signal.h>
 ],
 [struct sigaction act, oact;
 sigemptyset(&act.sa_mask);
 act.sa_flags = SA_RESTART;
 sigaction(0, &act, &oact);],
 [pgac_cv_func_posix_signals=yes],
 [pgac_cv_func_posix_signals=no])])
 if test x"$pgac_cv_func_posix_signals" = xyes ; then
   AC_DEFINE(HAVE_POSIX_SIGNALS,, [Define to 1 if you have the POSIX signal interface.])
 fi
 HAVE_POSIX_SIGNALS=$pgac_cv_func_posix_signals
 AC_SUBST(HAVE_POSIX_SIGNALS)])# PGAC_FUNC_POSIX_SIGNALS


 # PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT
 # ---------------------------------------
 # Determine which format snprintf uses for long long int.  We handle
 # %lld, %qd, %I64d.  The result is in shell variable
 # LONG_LONG_INT_FORMAT.
 #
 # MinGW uses '%I64d', though gcc throws an warning with -Wall,
 # while '%lld' doesn't generate a warning, but doesn't work.
 #
 AC_DEFUN([PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT],
 [AC_MSG_CHECKING([snprintf format for long long int])
 AC_CACHE_VAL(pgac_cv_snprintf_long_long_int_format,
 [for pgac_format in '%lld' '%qd' '%I64d'; do
 AC_TRY_RUN([#include <stdio.h>
 typedef long long int ac_int64;
 #define INT64_FORMAT "$pgac_format"

 ac_int64 a = 20000001;
 ac_int64 b = 40000005;

 int does_int64_snprintf_work()
 {
   ac_int64 c;
   char buf[100];

   if (sizeof(ac_int64) != 8)
     return 0;			/* doesn't look like the right size */

   c = a * b;
   snprintf(buf, 100, INT64_FORMAT, c);
   if (strcmp(buf, "800000140000005") != 0)
     return 0;			/* either multiply or snprintf is busted */
   return 1;
 }
 main() {
   exit(! does_int64_snprintf_work());
 }],
 [pgac_cv_snprintf_long_long_int_format=$pgac_format; break],
 [],
 [pgac_cv_snprintf_long_long_int_format=cross; break])
 done])dnl AC_CACHE_VAL

 LONG_LONG_INT_FORMAT=''

 case $pgac_cv_snprintf_long_long_int_format in
   cross) AC_MSG_RESULT([cannot test (not on host machine)]);;
   ?*)    AC_MSG_RESULT([$pgac_cv_snprintf_long_long_int_format])
          LONG_LONG_INT_FORMAT=$pgac_cv_snprintf_long_long_int_format;;
   *)     AC_MSG_RESULT(none);;
 esac])# PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT


 # PGAC_FUNC_PRINTF_ARG_CONTROL
 # ---------------------------------------
 # Determine if printf supports %1$ argument selection, e.g. %5$ selects
 # the fifth argument after the printf print string.
 # This is not in the C99 standard, but in the Single Unix Specification (SUS).
 # It is used in our language translation strings.
 #
 AC_DEFUN([PGAC_FUNC_PRINTF_ARG_CONTROL],
 [AC_MSG_CHECKING([whether printf supports argument control])
 AC_CACHE_VAL(pgac_cv_printf_arg_control,
 [AC_TRY_RUN([#include <stdio.h>
 #include <string.h>

 int main()
 {
   char buf[100];

   /* can it swap arguments? */
   snprintf(buf, 100, "%2\$d %1\$d", 3, 4);
   if (strcmp(buf, "4 3") != 0)
     return 1;
   return 0;
 }],
 [pgac_cv_printf_arg_control=yes],
 [pgac_cv_printf_arg_control=no],
 [pgac_cv_printf_arg_control=cross])
 ])dnl AC_CACHE_VAL
 AC_MSG_RESULT([$pgac_cv_printf_arg_control])
 ])# PGAC_FUNC_PRINTF_ARG_CONTROL

 # PGAC_TYPE_LOCALE_T
 # ------------------
 # Check for the locale_t type and find the right header file.  Mac OS
 # X needs xlocale.h; standard is locale.h, but glibc also has an
 # xlocale.h file that we should not use.
 #
 AC_DEFUN([PGAC_TYPE_LOCALE_T],
 [AC_CACHE_CHECK([for locale_t], pgac_cv_type_locale_t,
 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
 [#include <locale.h>
 locale_t x;],
 [])],
 [pgac_cv_type_locale_t=yes],
 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
 [#include <xlocale.h>
 locale_t x;],
 [])],
 [pgac_cv_type_locale_t='yes (in xlocale.h)'],
 [pgac_cv_type_locale_t=no])])])
 if test "$pgac_cv_type_locale_t" != no; then
   AC_DEFINE(HAVE_LOCALE_T, 1,
             [Define to 1 if the system has the type `locale_t'.])
 fi
 if test "$pgac_cv_type_locale_t" = 'yes (in xlocale.h)'; then
   AC_DEFINE(LOCALE_T_IN_XLOCALE, 1,
             [Define to 1 if `locale_t' requires <xlocale.h>.])
 fi])])# PGAC_HEADER_XLOCALE

 # backport from Autoconf 2.61a
 # http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=f0c325537a22105536ac8c4e88656e50f9946486

 # AC_FUNC_FSEEKO
 # --------------
 AN_FUNCTION([ftello], [AC_FUNC_FSEEKO])
 AN_FUNCTION([fseeko], [AC_FUNC_FSEEKO])
 AC_DEFUN([AC_FUNC_FSEEKO],
 [_AC_SYS_LARGEFILE_MACRO_VALUE(_LARGEFILE_SOURCE, 1,
    [ac_cv_sys_largefile_source],
    [Define to 1 to make fseeko visible on some hosts (e.g. glibc 2.2).],
    [[#include <sys/types.h> /* for off_t */
      #include <stdio.h>]],
    [[int (*fp) (FILE *, off_t, int) = fseeko;
      return fseeko (stdin, 0, 0) && fp (stdin, 0, 0);]])

 # We used to try defining _XOPEN_SOURCE=500 too, to work around a bug
 # in glibc 2.1.3, but that breaks too many other things.
 # If you want fseeko and ftello with glibc, upgrade to a fixed glibc.
 if test $ac_cv_sys_largefile_source != unknown; then
   AC_DEFINE(HAVE_FSEEKO, 1,
     [Define to 1 if fseeko (and presumably ftello) exists and is declared.])
 fi
 ])# AC_FUNC_FSEEKO
	# Macros that test various C library quirks
	# $PostgreSQL: pgsql/config/c-library.m4,v 1.33 2008/08/21 13:53:28 petere Exp $


	# PGAC_VAR_INT_TIMEZONE
	# ---------------------
	# Check if the global variable `timezone' exists. If so, define
	# HAVE_INT_TIMEZONE.
	AC_DEFUN([PGAC_VAR_INT_TIMEZONE],
	[AC_CACHE_CHECK(for int timezone, pgac_cv_var_int_timezone,
	[AC_TRY_LINK([#include <time.h>
	int res;],
	[#ifndef __CYGWIN__
	res = timezone / 60;
	#else
	res = _timezone / 60;
	#endif],
	[pgac_cv_var_int_timezone=yes],
	[pgac_cv_var_int_timezone=no])])
	if test x"$pgac_cv_var_int_timezone" = xyes ; then
	AC_DEFINE(HAVE_INT_TIMEZONE,, [Define to 1 if you have the global variable 'int timezone'.])
	fi])# PGAC_VAR_INT_TIMEZONE


	# PGAC_STRUCT_TIMEZONE
	# ------------------
	# Figure out how to get the current timezone. If `struct tm' has a
	# `tm_zone' member, define `HAVE_TM_ZONE'. Also, if the
	# external array `tzname' is found, define `HAVE_TZNAME'.
	# This is the same as the standard macro AC_STRUCT_TIMEZONE, except that
	# tzname[] is checked for regardless of whether we find tm_zone.
	AC_DEFUN([PGAC_STRUCT_TIMEZONE],
	[AC_REQUIRE([AC_STRUCT_TM])dnl
	AC_CHECK_MEMBERS([struct tm.tm_zone],,,[#include <sys/types.h>
	#include <$ac_cv_struct_tm>
	])
	if test "$ac_cv_member_struct_tm_tm_zone" = yes; then
	AC_DEFINE(HAVE_TM_ZONE, 1,
	[Define to 1 if your `struct tm' has `tm_zone'. Deprecated, use
	`HAVE_STRUCT_TM_TM_ZONE' instead.])
	fi
	AC_CACHE_CHECK(for tzname, ac_cv_var_tzname,
	[AC_TRY_LINK(
	[#include <time.h>
	#ifndef tzname /* For SGI. */
	extern char tzname[]; / RS6000 and others reject char *tzname. /
	#endif
	],
	[atoi(*tzname);], ac_cv_var_tzname=yes, ac_cv_var_tzname=no)])
	if test $ac_cv_var_tzname = yes; then
	AC_DEFINE(HAVE_TZNAME, 1,
	[Define to 1 if you have the external array `tzname'.])
	fi
	])# PGAC_STRUCT_TIMEZONE


	# PGAC_FUNC_GETTIMEOFDAY_1ARG
	# ---------------------------
	# Check if gettimeofday() has only one arguments. (Normal is two.)
	# If so, define GETTIMEOFDAY_1ARG.
	AC_DEFUN([PGAC_FUNC_GETTIMEOFDAY_1ARG],
	[AC_CACHE_CHECK(whether gettimeofday takes only one argument,
	pgac_cv_func_gettimeofday_1arg,
	[AC_TRY_COMPILE([#include <sys/time.h>],
	[struct timeval *tp;
	struct timezone *tzp;
	gettimeofday(tp,tzp);],
	[pgac_cv_func_gettimeofday_1arg=no],
	[pgac_cv_func_gettimeofday_1arg=yes])])
	if test x"$pgac_cv_func_gettimeofday_1arg" = xyes ; then
	AC_DEFINE(GETTIMEOFDAY_1ARG,, [Define to 1 if gettimeofday() takes only 1 argument.])
	fi
	AH_VERBATIM(GETTIMEOFDAY_1ARG_,
	[@%:@ifdef GETTIMEOFDAY_1ARG
	@%:@ define gettimeofday(a,b) gettimeofday(a)
	@%:@endif])dnl
	])# PGAC_FUNC_GETTIMEOFDAY_1ARG


	# PGAC_FUNC_GETPWUID_R_5ARG
	# ---------------------------
	# Check if getpwuid_r() takes a fifth argument (later POSIX standard, not draft version)
	# If so, define GETPWUID_R_5ARG
	AC_DEFUN([PGAC_FUNC_GETPWUID_R_5ARG],
	[AC_CACHE_CHECK(whether getpwuid_r takes a fifth argument,
	pgac_cv_func_getpwuid_r_5arg,
	[AC_TRY_COMPILE([#include <sys/types.h>
	#include <pwd.h>],
	[uid_t uid;
	struct passwd *space;
	char *buf;
	size_t bufsize;
	struct passwd **result;
	getpwuid_r(uid, space, buf, bufsize, result);],
	[pgac_cv_func_getpwuid_r_5arg=yes],
	[pgac_cv_func_getpwuid_r_5arg=no])])
	if test x"$pgac_cv_func_getpwuid_r_5arg" = xyes ; then
	AC_DEFINE(GETPWUID_R_5ARG,, [Define to 1 if getpwuid_r() takes a 5th argument.])
	fi
	])# PGAC_FUNC_GETPWUID_R_5ARG


	# PGAC_FUNC_STRERROR_R_INT
	# ---------------------------
	# Check if strerror_r() returns an int (SUSv3) rather than a char * (GNU libc)
	# If so, define STRERROR_R_INT
	AC_DEFUN([PGAC_FUNC_STRERROR_R_INT],
	[AC_CACHE_CHECK(whether strerror_r returns int,
	pgac_cv_func_strerror_r_int,
	[AC_TRY_COMPILE([#include <string.h>],
	[#ifndef _AIX
	int strerror_r(int, char *, size_t);
	#else
	/* Older AIX has 'int' for the third argument so we don't test the args. */
	int strerror_r();
	#endif],
	[pgac_cv_func_strerror_r_int=yes],
	[pgac_cv_func_strerror_r_int=no])])
	if test x"$pgac_cv_func_strerror_r_int" = xyes ; then
	AC_DEFINE(STRERROR_R_INT,, [Define to 1 if strerror_r() returns a int.])
	fi
	])# PGAC_FUNC_STRERROR_R_INT


	# PGAC_UNION_SEMUN
	# ----------------
	# Check if `union semun' exists. Define HAVE_UNION_SEMUN if so.
	# If it doesn't then one could define it as
	# union semun { int val; struct semid_ds buf; unsigned short array; }
	AC_DEFUN([PGAC_UNION_SEMUN],
	[AC_CHECK_TYPES([union semun], [], [],
	[#include <sys/types.h>
	#include <sys/ipc.h>
	#include <sys/sem.h>])])# PGAC_UNION_SEMUN


	# PGAC_STRUCT_SOCKADDR_UN
	# -----------------------
	# If `struct sockaddr_un' exists, define HAVE_UNIX_SOCKETS.
	# (Requires test for <sys/un.h>!)
	AC_DEFUN([PGAC_STRUCT_SOCKADDR_UN],
	[AC_CHECK_TYPES([struct sockaddr_un], [AC_DEFINE(HAVE_UNIX_SOCKETS, 1, [Define to 1 if you have unix sockets.])], [],
	[#include <sys/types.h>
	#ifdef HAVE_SYS_UN_H
	#include <sys/un.h>
	#endif
	])])# PGAC_STRUCT_SOCKADDR_UN


	# PGAC_STRUCT_SOCKADDR_STORAGE
	# ----------------------------
	# If `struct sockaddr_storage' exists, define HAVE_STRUCT_SOCKADDR_STORAGE.
	# If it is missing then one could define it.
	AC_DEFUN([PGAC_STRUCT_SOCKADDR_STORAGE],
	[AC_CHECK_TYPES([struct sockaddr_storage], [], [],
	[#include <sys/types.h>
	#ifdef HAVE_SYS_SOCKET_H
	#include <sys/socket.h>
	#endif
	])])# PGAC_STRUCT_SOCKADDR_STORAGE

	# PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS
	# --------------------------------------
	# Check the members of `struct sockaddr_storage'. We need to know about
	# ss_family and ss_len. (Some platforms follow RFC 2553 and call them
	# __ss_family and __ss_len.) We also check struct sockaddr's sa_len;
	# if we have to define our own `struct sockaddr_storage', this tells us
	# whether we need to provide an ss_len field.
	AC_DEFUN([PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS],
	[AC_CHECK_MEMBERS([struct sockaddr_storage.ss_family,
	struct sockaddr_storage.__ss_family,
	struct sockaddr_storage.ss_len,
	struct sockaddr_storage.__ss_len,
	struct sockaddr.sa_len], [], [],
	[#include <sys/types.h>
	#ifdef HAVE_SYS_SOCKET_H
	#include <sys/socket.h>
	#endif
	])])# PGAC_STRUCT_SOCKADDR_STORAGE_MEMBERS


	# PGAC_STRUCT_ADDRINFO
	# -----------------------
	# If `struct addrinfo' exists, define HAVE_STRUCT_ADDRINFO.
	AC_DEFUN([PGAC_STRUCT_ADDRINFO],
	[AC_CHECK_TYPES([struct addrinfo], [], [],
	[#include <sys/types.h>
	#include <sys/socket.h>
	#include <netdb.h>
	])])# PGAC_STRUCT_ADDRINFO


	# PGAC_FUNC_POSIX_SIGNALS
	# -----------------------
	# Check to see if the machine has the POSIX signal interface. Define
	# HAVE_POSIX_SIGNALS if so. Also set the output variable HAVE_POSIX_SIGNALS
	# to yes or no.
	#
	# Note that this test only compiles a test program, it doesn't check
	# whether the routines actually work. If that becomes a problem, make
	# a fancier check.
	AC_DEFUN([PGAC_FUNC_POSIX_SIGNALS],
	[AC_CACHE_CHECK(for POSIX signal interface, pgac_cv_func_posix_signals,
	[AC_TRY_LINK([#include <signal.h>
	],
	[struct sigaction act, oact;
	sigemptyset(&act.sa_mask);
	act.sa_flags = SA_RESTART;
	sigaction(0, &act, &oact);],
	[pgac_cv_func_posix_signals=yes],
	[pgac_cv_func_posix_signals=no])])
	if test x"$pgac_cv_func_posix_signals" = xyes ; then
	AC_DEFINE(HAVE_POSIX_SIGNALS,, [Define to 1 if you have the POSIX signal interface.])
	fi
	HAVE_POSIX_SIGNALS=$pgac_cv_func_posix_signals
	AC_SUBST(HAVE_POSIX_SIGNALS)])# PGAC_FUNC_POSIX_SIGNALS


	# PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT
	# ---------------------------------------
	# Determine which format snprintf uses for long long int. We handle
	# %lld, %qd, %I64d. The result is in shell variable
	# LONG_LONG_INT_FORMAT.
	#
	# MinGW uses '%I64d', though gcc throws an warning with -Wall,
	# while '%lld' doesn't generate a warning, but doesn't work.
	#
	AC_DEFUN([PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT],
	[AC_MSG_CHECKING([snprintf format for long long int])
	AC_CACHE_VAL(pgac_cv_snprintf_long_long_int_format,
	[for pgac_format in '%lld' '%qd' '%I64d'; do
	AC_TRY_RUN([#include <stdio.h>
	typedef long long int ac_int64;
	#define INT64_FORMAT "$pgac_format"

	ac_int64 a = 20000001;
	ac_int64 b = 40000005;

	int does_int64_snprintf_work()
	{
	ac_int64 c;
	char buf[100];

	if (sizeof(ac_int64) != 8)
	return 0; /* doesn't look like the right size */

	c = a * b;
	snprintf(buf, 100, INT64_FORMAT, c);
	if (strcmp(buf, "800000140000005") != 0)
	return 0; /* either multiply or snprintf is busted */
	return 1;
	}
	main() {
	exit(! does_int64_snprintf_work());
	}],
	[pgac_cv_snprintf_long_long_int_format=$pgac_format; break],
	[],
	[pgac_cv_snprintf_long_long_int_format=cross; break])
	done])dnl AC_CACHE_VAL

	LONG_LONG_INT_FORMAT=''

	case $pgac_cv_snprintf_long_long_int_format in
	cross) AC_MSG_RESULT([cannot test (not on host machine)]);;
	?*) AC_MSG_RESULT([$pgac_cv_snprintf_long_long_int_format])
	LONG_LONG_INT_FORMAT=$pgac_cv_snprintf_long_long_int_format;;
	*) AC_MSG_RESULT(none);;
	esac])# PGAC_FUNC_SNPRINTF_LONG_LONG_INT_FORMAT


	# PGAC_FUNC_PRINTF_ARG_CONTROL
	# ---------------------------------------
	# Determine if printf supports %1$ argument selection, e.g. %5$ selects
	# the fifth argument after the printf print string.
	# This is not in the C99 standard, but in the Single Unix Specification (SUS).
	# It is used in our language translation strings.
	#
	AC_DEFUN([PGAC_FUNC_PRINTF_ARG_CONTROL],
	[AC_MSG_CHECKING([whether printf supports argument control])
	AC_CACHE_VAL(pgac_cv_printf_arg_control,
	[AC_TRY_RUN([#include <stdio.h>
	#include <string.h>

	int main()
	{
	char buf[100];

	/* can it swap arguments? */
	snprintf(buf, 100, "%2\$d %1\$d", 3, 4);
	if (strcmp(buf, "4 3") != 0)
	return 1;
	return 0;
	}],
	[pgac_cv_printf_arg_control=yes],
	[pgac_cv_printf_arg_control=no],
	[pgac_cv_printf_arg_control=cross])
	])dnl AC_CACHE_VAL
	AC_MSG_RESULT([$pgac_cv_printf_arg_control])
	])# PGAC_FUNC_PRINTF_ARG_CONTROL

	# PGAC_TYPE_LOCALE_T
	# ------------------
	# Check for the locale_t type and find the right header file. Mac OS
	# X needs xlocale.h; standard is locale.h, but glibc also has an
	# xlocale.h file that we should not use.
	#
	AC_DEFUN([PGAC_TYPE_LOCALE_T],
	[AC_CACHE_CHECK([for locale_t], pgac_cv_type_locale_t,
	[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
	[#include <locale.h>
	locale_t x;],
	[])],
	[pgac_cv_type_locale_t=yes],
	[AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
	[#include <xlocale.h>
	locale_t x;],
	[])],
	[pgac_cv_type_locale_t='yes (in xlocale.h)'],
	[pgac_cv_type_locale_t=no])])])
	if test "$pgac_cv_type_locale_t" != no; then
	AC_DEFINE(HAVE_LOCALE_T, 1,
	[Define to 1 if the system has the type `locale_t'.])
	fi
	if test "$pgac_cv_type_locale_t" = 'yes (in xlocale.h)'; then
	AC_DEFINE(LOCALE_T_IN_XLOCALE, 1,
	[Define to 1 if `locale_t' requires <xlocale.h>.])
	fi])])# PGAC_HEADER_XLOCALE

	# backport from Autoconf 2.61a
	# http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=f0c325537a22105536ac8c4e88656e50f9946486

	# AC_FUNC_FSEEKO
	# --------------
	AN_FUNCTION([ftello], [AC_FUNC_FSEEKO])
	AN_FUNCTION([fseeko], [AC_FUNC_FSEEKO])
	AC_DEFUN([AC_FUNC_FSEEKO],
	[_AC_SYS_LARGEFILE_MACRO_VALUE(_LARGEFILE_SOURCE, 1,
	[ac_cv_sys_largefile_source],
	[Define to 1 to make fseeko visible on some hosts (e.g. glibc 2.2).],
	[[#include <sys/types.h> /* for off_t */
	#include <stdio.h>]],
	[[int (fp) (FILE , off_t, int) = fseeko;
	return fseeko (stdin, 0, 0) && fp (stdin, 0, 0);]])

	# We used to try defining _XOPEN_SOURCE=500 too, to work around a bug
	# in glibc 2.1.3, but that breaks too many other things.
	# If you want fseeko and ftello with glibc, upgrade to a fixed glibc.
	if test $ac_cv_sys_largefile_source != unknown; then
	AC_DEFINE(HAVE_FSEEKO, 1,
	[Define to 1 if fseeko (and presumably ftello) exists and is declared.])
	fi
	])# AC_FUNC_FSEEKO