dnl ** Additional Autoconf tests for BIRD configure script
dnl ** (c) 1999 Martin Mares <mj@ucw.cz>

AC_DEFUN([BIRD_CHECK_STRUCT_ALIGN],
[
  AC_CACHE_CHECK(
    [usual alignment of structures],
    [bird_cv_c_struct_align],
    [
      AC_TRY_RUN(
	[
	  #include <stdio.h>

	  struct { char x; long int y; } ary[2];

	  int main(void)
	  {
	    FILE *f = fopen("conftestresult", "w");
	    if (!f)
	      return 10;
	    fprintf(f, "%d", sizeof(ary)/2);
	    fclose(f);
	    exit(0);
	  }
	],
	[bird_cv_c_struct_align=$(cat conftestresult)],
	[
	  AC_MSG_RESULT([test program failed])
	  AC_MSG_ERROR([Cannot determine structure alignment])
	],
	[bird_cv_c_struct_align=16]
      )
    ]
  )

  AC_DEFINE_UNQUOTED([CPU_STRUCT_ALIGN],
    [$bird_cv_c_struct_align],
    [Usual alignment of structures]
  )
])

AC_DEFUN([BIRD_CHECK_TIME_T],
[
  AC_CACHE_CHECK(
    [characteristics of time_t],
    [bird_cv_type_time_t],
    [
      AC_TRY_RUN(
	[
	  #include <stdio.h>
	  #include <sys/time.h>
	  #include <limits.h>

	  int main(void)
	  {
	    FILE *f = fopen("conftestresult", "w");
	    if (!f)
	      return 10;
	    fprintf(f, "%d-bit ", sizeof(time_t)*CHAR_BIT);
	    if ((time_t) -1 > 0)
	      fprintf(f, "un");
	    fprintf(f, "signed");
	    fclose(f);
	    exit(0);
	  }
	],
	[bird_cv_type_time_t=$(cat conftestresult)],
	[
	  AC_MSG_RESULT([test program failed])
	  AC_MSG_ERROR([Cannot determine time_t size and signedness.])
	],
	[bird_cv_type_time_t="32-bit signed"]
      )
    ]
  )

  case "$bird_cv_type_time_t" in
    *64-bit*)
      AC_DEFINE([TIME_T_IS_64BIT], [1],	[Define to 1 if time_t is 64 bit])
      ;;
  esac

  case "$bird_cv_type_time_t" in
    *unsigned*)
      ;;
    *)
      AC_DEFINE([TIME_T_IS_SIGNED], [1], [Define to 1 if time_t is signed])
      ;;
  esac
])

AC_DEFUN([BIRD_CHECK_PTHREADS],
[
  bird_tmp_cflags="$CFLAGS"
  CFLAGS="$CFLAGS -pthread"

  AC_CACHE_CHECK(
    [whether POSIX threads are available],
    [bird_cv_lib_pthreads],
    [
      AC_LINK_IFELSE(
	[
	  AC_LANG_PROGRAM(
	    [ #include <pthread.h> ],
	    [
	      pthread_t pt;
	      pthread_create(&pt, NULL, NULL, NULL);
	      pthread_spinlock_t lock;
	      pthread_spin_lock(&lock);
	    ]
	  )
	],
	[bird_cv_lib_pthreads=yes],
	[bird_cv_lib_pthreads=no]
      )
    ]
  )

  CFLAGS="$bird_tmp_cflags"
])

AC_DEFUN([BIRD_CHECK_GCC_OPTION],
[
  bird_tmp_cflags="$CFLAGS"
  CFLAGS="$3 $2"

  AC_CACHE_CHECK(
    [whether CC supports $2],
    [$1],
    [
      AC_COMPILE_IFELSE(
	[AC_LANG_PROGRAM()],
	[$1=yes],
	[$1=no]
      )
    ]
  )

  CFLAGS="$bird_tmp_cflags"
])

AC_DEFUN([BIRD_ADD_GCC_OPTION],
[
  if test "$$1" = yes ; then
    CFLAGS="$CFLAGS $2"
  fi
])

# BIRD_CHECK_PROG_FLAVOR_GNU(PROGRAM-PATH, IF-SUCCESS, [IF-FAILURE])
# copied from autoconf internal _AC_PATH_PROG_FLAVOR_GNU
AC_DEFUN([BIRD_CHECK_PROG_FLAVOR_GNU],
[
  # Check for GNU $1
  case `"$1" --version 2>&1` in
    *GNU*)
      $2
      ;;
  m4_ifval([$3],
    [*)
      $3
      ;;
    ]
  )
  esac
])