?RCS: $Id: d_union_semun.U,v $
?RCS:
?RCS: Copyright (c) 1998 Andy Dougherty
?RCS:
?RCS: You may distribute under the terms of either the GNU General Public
?RCS: License or the Artistic License, as specified in the README file.
?RCS:
?RCS: $Log: d_union_semun.U,v $
?RCS:
?MAKE:d_union_semun d_semctl_semun d_semctl_semid_ds: Compile Setvar Myread run \
	cat rm_try d_sem
?MAKE:	-pick add $@ %<
?S:d_union_semun:
?S:	This variable conditionally defines HAS_UNION_SEMUN if the
?S:	union semun is defined by including <sys/sem.h>.
?S:.
?S:d_semctl_semun:
?S:	This variable conditionally defines USE_SEMCTL_SEMUN, which
?S:	indicates that union semun is to be used for semctl IPC_STAT.
?S:.
?S:d_semctl_semid_ds:
?S:	This variable conditionally defines USE_SEMCTL_SEMID_DS, which
?S:	indicates that struct semid_ds * is to be used for semctl IPC_STAT.
?S:.
?C:HAS_UNION_SEMUN:
?C:	This symbol, if defined, indicates that the union semun is
?C:	defined by including <sys/sem.h>.  If not, the user code
?C:	probably needs to define it as:
?C:	union semun {
?C:	    int val;
?C:	    struct semid_ds *buf;
?C:	    unsigned short *array;
?C:	}
?C:.
?C:USE_SEMCTL_SEMUN:
?C:	This symbol, if defined, indicates that union semun is
?C:	used for semctl IPC_STAT.
?C:.
?C:USE_SEMCTL_SEMID_DS:
?C:	This symbol, if defined, indicates that struct semid_ds * is
?C:	used for semctl IPC_STAT.
?C:.
?H:#$d_union_semun HAS_UNION_SEMUN	/**/
?H:#$d_semctl_semun USE_SEMCTL_SEMUN	/**/
?H:#$d_semctl_semid_ds USE_SEMCTL_SEMID_DS	/**/
?H:.
?T:xxx also
?F:!try
?LINT: set d_union_semun d_semctl_semun d_semctl_semid_ds
: see whether sys/sem.h defines union semun
echo " "
$cat > try.c <<'END'
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
int main () { union semun semun; semun.buf = 0; }
END
set try
if eval $compile; then
    echo "You have union semun in <sys/sem.h>." >&4
    val="$define"
else
    echo "You do not have union semun in <sys/sem.h>." >&4
    val="$undef"
fi
$rm_try
set d_union_semun
eval $setvar

: see how to do semctl IPC_STAT
case "$d_sem" in
$define)
    echo " "
?X: use tryh.h instead of try.h because $rm_try cleans up try.*
    $cat > tryh.h <<END
#ifndef S_IRUSR
#   ifdef S_IREAD
#	define S_IRUSR S_IREAD
#	define S_IWUSR S_IWRITE
#	define S_IXUSR S_IEXEC
#   else
#	define S_IRUSR 0400
#	define S_IWUSR 0200
#	define S_IXUSR 0100
#   endif
#   define S_IRGRP (S_IRUSR>>3)
#   define S_IWGRP (S_IWUSR>>3)
#   define S_IXGRP (S_IXUSR>>3)
#   define S_IROTH (S_IRUSR>>6)
#   define S_IWOTH (S_IWUSR>>6)
#   define S_IXOTH (S_IXUSR>>6)
#endif
#ifndef S_IRWXU
#   define S_IRWXU (S_IRUSR|S_IWUSR|S_IXUSR)
#   define S_IRWXG (S_IRGRP|S_IWGRP|S_IXGRP)
#   define S_IRWXO (S_IROTH|S_IWOTH|S_IXOTH)
#endif
END
    : see whether semctl IPC_STAT can use union semun
    case "$d_semctl_semun" in
    '')
      val="$undef"
      $cat > try.c <<END
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include "tryh.h"
#ifndef errno
extern int errno;
#endif
#$d_union_semun HAS_UNION_SEMUN
int main() {
    union semun
#ifndef HAS_UNION_SEMUN
    {
	int val;
	struct semid_ds *buf;
	unsigned short *array;
    }
#endif
    arg;
    int sem, st;

#if defined(IPC_PRIVATE) && defined(S_IRWXU) && defined(S_IRWXG) && defined(S_IRWXO) && defined(IPC_CREAT)
    sem = semget(IPC_PRIVATE, 1, S_IRWXU|S_IRWXG|S_IRWXO|IPC_CREAT);
    if (sem > -1) {
	struct semid_ds argbuf;
	arg.buf = &argbuf;
#	ifdef IPC_STAT
	st = semctl(sem, 0, IPC_STAT, arg);
	if (st == 0)
	    printf("semun\n");
	else
#	endif /* IPC_STAT */
	    printf("semctl IPC_STAT failed: errno = %d\n", errno);
#	ifdef IPC_RMID
	if (semctl(sem, 0, IPC_RMID, arg) != 0)
#	endif /* IPC_RMID */
	    printf("semctl IPC_RMID failed: errno = %d\n", errno);
    } else
#endif /* IPC_PRIVATE && ... */
	printf("semget failed: errno = %d\n", errno);
  return 0;
}
END
      set try
      if eval $compile; then
	  xxx=`$run ./try`
          case "$xxx" in
          semun) val="$define" ;;
          esac
      fi
      $rm_try
      set d_semctl_semun
      eval $setvar
      ;;
    esac
    case "$d_semctl_semun" in
    $define)
        echo "You can use union semun for semctl IPC_STAT." >&4
	also='also'
        ;;
    *)  echo "You cannot use union semun for semctl IPC_STAT." >&4
	also=''
        ;;
    esac

    : see whether semctl IPC_STAT can use struct semid_ds pointer
    case "$d_semctl_semid_ds" in
    '')
      val="$undef"
      $cat > try.c <<'END'
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/stat.h>
#include "tryh.h"
#include <stdio.h>
#include <errno.h>
#ifndef errno
extern int errno;
#endif
int main() {
    struct semid_ds arg;
    int sem, st;

#if defined(IPC_PRIVATE) && defined(S_IRWXU) && defined(S_IRWXG) &&  defined(S_IRWXO) && defined(IPC_CREAT)
    sem = semget(IPC_PRIVATE, 1, S_IRWXU|S_IRWXG|S_IRWXO|IPC_CREAT);
    if (sem > -1) {
#	ifdef IPC_STAT
	st = semctl(sem, 0, IPC_STAT, &arg);
	if (st == 0)
	    printf("semid_ds\n");
	else
#	endif /* IPC_STAT */
	    printf("semctl IPC_STAT failed: errno = %d\n", errno);
#	ifdef IPC_RMID
	if (semctl(sem, 0, IPC_RMID, &arg) != 0)
#	endif /* IPC_RMID */
	    printf("semctl IPC_RMID failed: errno = %d\n", errno);
    } else
#endif /* IPC_PRIVATE && ... */
	printf("semget failed: errno = %d\n", errno);

    return 0;
}
END
      set try
      if eval $compile; then
          xxx=`$run ./try`
          case "$xxx" in
          semid_ds) val="$define" ;;
          esac
      fi
      $rm_try
      set d_semctl_semid_ds
      eval $setvar
      ;;
    esac
    case "$d_semctl_semid_ds" in
    $define)
        echo "You can $also use struct semid_ds* for semctl IPC_STAT." >&4
        ;;
    *)  echo "You cannot use struct semid_ds* for semctl IPC_STAT." >&4
        ;;
    esac
    ;;
*)  val="$undef"

    # We do not have the full sem*(2) library, so assume we can not
    # use either.

    set d_semctl_semun
    eval $setvar

    set d_semctl_semid_ds
    eval $setvar
    ;;
esac
$rm_try tryh.h