path: root/aclocal.m4

% Copyright (C) 2000, 2001  Free Software Foundation, Inc.
%
% This file is part of GNU Emacs.
%
% GNU Emacs is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2, or (at your option)
% any later version.
%
% GNU Emacs is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with GNU Emacs; see the file COPYING.  If not, write to the
% Free Software Foundation, Inc., 59 Temple Place - Suite 330,
% Boston, MA 02111-1307, USA.

ifelse(_AC_VERSION_COMPARE(AC_ACVERSION, [2.14]), -1,

# AC_PROG_CC_STDC
# ---------------
# If the C compiler in not in ANSI C mode by default, try to add an
# option to output variable @code{CC} to make it so.  This macro tries
# various options that select ANSI C on some system or another.  It
# considers the compiler to be in ANSI C mode if it handles function
# prototypes correctly.
AC_DEFUN(AC_PROG_CC_STDC,
[AC_REQUIRE([AC_PROG_CC])dnl
AC_BEFORE([$0], [AC_C_INLINE])dnl
AC_BEFORE([$0], [AC_C_CONST])dnl
dnl Force this before AC_PROG_CPP.  Some cpp's, eg on HPUX, require
dnl a magic option to avoid problems with ANSI preprocessor commands
dnl like #elif.
dnl FIXME: can't do this because then AC_AIX won't work due to a
dnl circular dependency.
dnl AC_BEFORE([$0], [AC_PROG_CPP])
AC_MSG_CHECKING(for ${CC-cc} option to accept ANSI C)
AC_CACHE_VAL(ac_cv_prog_cc_stdc,
[ac_cv_prog_cc_stdc=no
ac_save_CC="$CC"
# Don't try gcc -ansi; that turns off useful extensions and
# breaks some systems' header files.
# AIX			-qlanglvl=ansi
# Ultrix and OSF/1	-std1
# HP-UX 10.20 and later	-Ae
# HP-UX older versions	-Aa -D_HPUX_SOURCE
# SVR4			-Xc -D__EXTENSIONS__
for ac_arg in "" -qlanglvl=ansi -std1 -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
do
  CC="$ac_save_CC $ac_arg"
  AC_TRY_COMPILE(
[#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
/* Most of the following tests are stolen from RCS 5.7's src/conf.sh.  */
struct buf { int x; };
FILE * (*rcsopen) (struct buf *, struct stat *, int);
static char *e (p, i)
     char **p;
     int i;
{
  return p[i];
}
static char *f (char * (*g) (char **, int), char **p, ...)
{
  char *s;
  va_list v;
  va_start (v,p);
  s = g (p, va_arg (v,int));
  va_end (v);
  return s;
}
int test (int i, double x);
struct s1 {int (*f) (int a);};
struct s2 {int (*f) (double a);};
int pairnames (int, char **, FILE *(*)(struct buf *, struct stat *, int), int, int);
int argc;
char **argv;],
[return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];],
[ac_cv_prog_cc_stdc="$ac_arg"; break])
done
CC="$ac_save_CC"
])
case "x$ac_cv_prog_cc_stdc" in
  x|xno)
    AC_MSG_RESULT([none needed]) ;;
  *)
    AC_MSG_RESULT($ac_cv_prog_cc_stdc)
    CC="$CC $ac_cv_prog_cc_stdc" ;;
esac
])# AC_PROG_CC_STDC

# AC_FUNC_MKTIME
# --------------
AC_DEFUN(AC_FUNC_MKTIME,
[AC_REQUIRE([AC_HEADER_TIME])dnl
AC_CHECK_HEADERS(sys/time.h unistd.h)
AC_CHECK_FUNCS(alarm)
AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime,
[AC_TRY_RUN(
[/* Test program from Paul Eggert (eggert@twinsun.com)
   and Tony Leneis (tony@plaza.ds.adp.com).  */
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif

#if HAVE_UNISTD_H
# include <unistd.h>
#endif

#if !HAVE_ALARM
# define alarm(X) /* empty */
#endif

/* Work around redefinition to rpl_putenv by other config tests.  */
#undef putenv

static time_t time_t_max;

/* Values we'll use to set the TZ environment variable.  */
static const char *const tz_strings[] = {
  (const char *) 0, "TZ=GMT0", "TZ=JST-9",
  "TZ=EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00"
};
#define N_STRINGS (sizeof (tz_strings) / sizeof (tz_strings[0]))

/* Fail if mktime fails to convert a date in the spring-forward gap.
   Based on a problem report from Andreas Jaeger.  */
static void
spring_forward_gap ()
{
  /* glibc (up to about 1998-10-07) failed this test) */
  struct tm tm;

  /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
     instead of "TZ=America/Vancouver" in order to detect the bug even
     on systems that don't support the Olson extension, or don't have the
     full zoneinfo tables installed.  */
  putenv ("TZ=PST8PDT,M4.1.0,M10.5.0");

  tm.tm_year = 98;
  tm.tm_mon = 3;
  tm.tm_mday = 5;
  tm.tm_hour = 2;
  tm.tm_min = 0;
  tm.tm_sec = 0;
  tm.tm_isdst = -1;
  if (mktime (&tm) == (time_t)-1)
    exit (1);
}

static void
mktime_test (now)
     time_t now;
{
  struct tm *lt;
  if ((lt = localtime (&now)) && mktime (lt) != now)
    exit (1);
  now = time_t_max - now;
  if ((lt = localtime (&now)) && mktime (lt) != now)
    exit (1);
}

static void
irix_6_4_bug ()
{
  /* Based on code from Ariel Faigon.  */
  struct tm tm;
  tm.tm_year = 96;
  tm.tm_mon = 3;
  tm.tm_mday = 0;
  tm.tm_hour = 0;
  tm.tm_min = 0;
  tm.tm_sec = 0;
  tm.tm_isdst = -1;
  mktime (&tm);
  if (tm.tm_mon != 2 || tm.tm_mday != 31)
    exit (1);
}

static void
bigtime_test (j)
     int j;
{
  struct tm tm;
  time_t now;
  tm.tm_year = tm.tm_mon = tm.tm_mday = tm.tm_hour = tm.tm_min = tm.tm_sec = j;
  now = mktime (&tm);
  if (now != (time_t) -1)
    {
      struct tm *lt = localtime (&now);
      if (! (lt
	     && lt->tm_year == tm.tm_year
	     && lt->tm_mon == tm.tm_mon
	     && lt->tm_mday == tm.tm_mday
	     && lt->tm_hour == tm.tm_hour
	     && lt->tm_min == tm.tm_min
	     && lt->tm_sec == tm.tm_sec
	     && lt->tm_yday == tm.tm_yday
	     && lt->tm_wday == tm.tm_wday
	     && ((lt->tm_isdst < 0 ? -1 : 0 < lt->tm_isdst)
		  == (tm.tm_isdst < 0 ? -1 : 0 < tm.tm_isdst))))
	exit (1);
    }
}

int
main ()
{
  time_t t, delta;
  int i, j;

  /* This test makes some buggy mktime implementations loop.
     Give up after 60 seconds; a mktime slower than that
     isn't worth using anyway.  */
  alarm (60);

  for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2)
    continue;
  time_t_max--;
  delta = time_t_max / 997; /* a suitable prime number */
  for (i = 0; i < N_STRINGS; i++)
    {
      if (tz_strings[i])
	putenv (tz_strings[i]);

      for (t = 0; t <= time_t_max - delta; t += delta)
	mktime_test (t);
      mktime_test ((time_t) 60 * 60);
      mktime_test ((time_t) 60 * 60 * 24);

      for (j = 1; 0 < j; j *= 2)
        bigtime_test (j);
      bigtime_test (j - 1);
    }
  irix_6_4_bug ();
  spring_forward_gap ();
  exit (0);
}],
ac_cv_func_working_mktime=yes, ac_cv_func_working_mktime=no,
ac_cv_func_working_mktime=no)])
if test $ac_cv_func_working_mktime = no; then
  LIBOBJS="$LIBOBJS mktime.${ac_objext}"
fi
AC_SUBST(LIBOBJS)dnl
])# AC_FUNC_MKTIME

# AC_C_VOLATILE
# -------------
# Note that, unlike const, #defining volatile to be the empty string can
# actually turn a correct program into an incorrect one, since removing
# uses of volatile actually grants the compiler permission to perform
# optimizations that could break the user's code.  So, do not #define
# volatile away unless it is really necessary to allow the user's code
# to compile cleanly.  Benign compiler failures should be tolerated.
AC_DEFUN(AC_C_VOLATILE,
[AC_REQUIRE([AC_PROG_CC_STDC])dnl
AC_CACHE_CHECK([for working volatile], ac_cv_c_volatile,
[AC_TRY_COMPILE(,[
volatile int x;
int * volatile y;],
ac_cv_c_volatile=yes, ac_cv_c_volatile=no)])
if test $ac_cv_c_volatile = no; then
  AC_DEFINE(volatile,,
            [Define to empty if the keyword `volatile' does not work.
             Warning: valid code using `volatile' can become incorrect
             without.  Disable with care.])
fi
])

# AC_C_PROTOTYPES
# ---------------
# Check if the C compiler supports prototypes, included if it needs
# options.
AC_DEFUN(AC_C_PROTOTYPES,
[AC_REQUIRE([AC_PROG_CC_STDC])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_MSG_CHECKING([for function prototypes])
if test "$ac_cv_prog_cc_stdc" != no; then
  AC_MSG_RESULT(yes)
  AC_DEFINE(PROTOTYPES, 1,
            [Define if the compiler supports function prototypes.])
else
  AC_MSG_RESULT(no)
fi
])# AC_C_PROTOTYPES

dnl The following is a bit different from the prerelease autoconf at
dnl this time since that requires extra definitions.

dnl By default, many hosts won't let programs access large files;
dnl one must use special compiler options to get large-file access to work.
dnl For more details about this brain damage please see:
dnl http://www.sas.com/standards/large.file/x_open.20Mar96.html

dnl Written by Paul Eggert <eggert@twinsun.com>.

dnl Internal subroutine of AC_SYS_LARGEFILE.
dnl AC_SYS_LARGEFILE_TEST_INCLUDES
AC_DEFUN(AC_SYS_LARGEFILE_TEST_INCLUDES,
  [[#include <sys/types.h>
    int a[(off_t) 9223372036854775807 == 9223372036854775807 ? 1 : -1];
  ]])

dnl Internal subroutine of AC_SYS_LARGEFILE.
dnl AC_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE, CACHE-VAR, COMMENT, INCLUDES, FUNCTION-BODY)
AC_DEFUN(AC_SYS_LARGEFILE_MACRO_VALUE,
  [AC_CACHE_CHECK([for $1 value needed for large files], $3,
     [$3=no
      AC_TRY_COMPILE([$5],
	[$6], 
	,
	[AC_TRY_COMPILE([#define $1 $2]
[$5]
	   ,
	   [$6],
	   [$3=$2])])])
   if test "[$]$3" != no; then
     AC_DEFINE_UNQUOTED([$1], [$]$3, [$4])
   fi])

AC_DEFUN(AC_SYS_LARGEFILE,
  [AC_REQUIRE([AC_PROG_CC])
   AC_ARG_ENABLE(largefile,
     [  --disable-largefile     omit support for large files])
   if test "$enable_largefile" != no; then

     AC_CACHE_CHECK([for special C compiler options needed for large files],
       ac_cv_sys_largefile_CC,
       [ac_cv_sys_largefile_CC=no
        if test "$GCC" != yes; then
	  # IRIX 6.2 and later do not support large files by default,
	  # so use the C compiler's -n32 option if that helps.
	  AC_TRY_COMPILE(AC_SYS_LARGEFILE_TEST_INCLUDES, , ,
	    [ac_save_CC="$CC"
	     CC="$CC -n32"
	     AC_TRY_COMPILE(AC_SYS_LARGEFILE_TEST_INCLUDES, ,
	       ac_cv_sys_largefile_CC=' -n32')
	     CC="$ac_save_CC"])
        fi])
     if test "$ac_cv_sys_largefile_CC" != no; then
       CC="$CC$ac_cv_sys_largefile_CC"
     fi

     AC_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64,
       ac_cv_sys_file_offset_bits,
       [Number of bits in a file offset, on hosts where this is settable.],
       AC_SYS_LARGEFILE_TEST_INCLUDES)
     AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1,
       ac_cv_sys_large_files,
       [Define for large files, on AIX-style hosts.]
       AC_SYS_LARGEFILE_TEST_INCLUDES)
   fi
  ])

AC_DEFUN(AC_FUNC_FSEEKO,
  [AC_SYS_LARGEFILE_MACRO_VALUE(_LARGEFILE_SOURCE, 1,
     ac_cv_sys_largefile_source,
     [Define to make fseeko visible on some hosts (e.g. glibc 2.2).],
     [#include <stdio.h>], [return !fseeko;])
   # 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.

   AC_CACHE_CHECK([for fseeko], ac_cv_func_fseeko,
     [ac_cv_func_fseeko=no
      AC_TRY_LINK([#include <stdio.h>],
        [return fseeko && fseeko (stdin, 0, 0);],
	[ac_cv_func_fseeko=yes])])
   if test $ac_cv_func_fseeko != no; then
     AC_DEFINE(HAVE_FSEEKO, 1,
       [Define if fseeko (and presumably ftello) exists and is declared.])
   fi])

undefine([AC_FUNC_MMAP])dnl
dnl The autoconf 2.13 version loses on OSF, at least,
dnl by messing up the declaration of malloc.
AC_DEFUN([AC_FUNC_MMAP],
[AC_CHECK_HEADERS(stdlib.h unistd.h sys/stat.h)
AC_CHECK_FUNCS(getpagesize)
AC_CACHE_CHECK(for working mmap, ac_cv_func_mmap_fixed_mapped,
[AC_TRY_RUN(
[/* 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 <sys/types.h>
#include <fcntl.h>
#include <sys/mman.h>

#if STDC_HEADERS || HAVE_STDLIB_H
# include <stdlib.h>
#else
char *malloc ();
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_SYS_STAT_H
# include <sys/stat.h>
#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 ("conftestmmap", 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 ("conftestmmap", 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);
  unlink ("conftestmmap");
  exit (0);
}], ac_cv_func_mmap_fixed_mapped=yes, ac_cv_func_mmap_fixed_mapped=no,
ac_cv_func_mmap_fixed_mapped=no)])
if test $ac_cv_func_mmap_fixed_mapped = yes; then
  AC_DEFINE(HAVE_MMAP, 1,
            [Define if you have a working `mmap' system call.])
fi
])# AC_FUNC_MMAP

) dnl ifelse