# acl.m4 - check for access control list (ACL) primitives
# serial 8

# Copyright (C) 2002, 2004-2008 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

# Written by Paul Eggert and Jim Meyering.

AC_DEFUN([gl_FUNC_ACL],
[
  AC_ARG_ENABLE([acl],
    AS_HELP_STRING([--disable-acl], [do not support ACLs]),
    , [enable_acl=auto])

  LIB_ACL=
  use_acl=0
  AC_REQUIRE([AC_C_INLINE])
  if test "x$enable_acl" != "xno"; then
    dnl On all platforms, the ACL related API is declared in <sys/acl.h>.
    AC_CHECK_HEADERS([sys/acl.h])
    if test $ac_cv_header_sys_acl_h = yes; then
      ac_save_LIBS=$LIBS

      dnl Test for POSIX-draft-like API (Linux, FreeBSD, MacOS X, IRIX, Tru64).
      dnl -lacl is needed on Linux, -lpacl is needed on OSF/1.
      if test $use_acl = 0; then
	AC_SEARCH_LIBS([acl_get_file], [acl pacl],
	  [if test "$ac_cv_search_acl_get_file" != "none required"; then
	     LIB_ACL=$ac_cv_search_acl_get_file
           fi
	   AC_CHECK_FUNCS(
	     [acl_get_file acl_get_fd acl_set_file acl_set_fd \
	      acl_free acl_from_mode acl_from_text \
	      acl_delete_def_file acl_extended_file \
	      acl_delete_fd_np acl_delete_file_np \
	      acl_copy_ext_native acl_create_entry_np \
	      acl_to_short_text acl_free_text])
	   # If the acl_get_file bug is detected, don't enable the ACL support.
	   gl_ACL_GET_FILE([use_acl=1], [])
	   if test $use_acl = 1; then
	     dnl On Linux, additional API is declared in <acl/libacl.h>.
	     AC_CHECK_HEADERS([acl/libacl.h])
	     AC_REPLACE_FUNCS([acl_entries])
	     AC_CACHE_CHECK([for ACL_FIRST_ENTRY],
	       [gl_cv_acl_ACL_FIRST_ENTRY],
	       [AC_COMPILE_IFELSE(
[[#include <sys/types.h>
#include <sys/acl.h>
int type = ACL_FIRST_ENTRY;]],
		  [gl_cv_acl_ACL_FIRST_ENTRY=yes],
		  [gl_cv_acl_ACL_FIRST_ENTRY=no])])
	     if test $gl_cv_acl_ACL_FIRST_ENTRY = yes; then
	       AC_DEFINE([HAVE_ACL_FIRST_ENTRY], 1,
		 [Define to 1 if the constant ACL_FIRST_ENTRY exists.])
	     fi
	     dnl On MacOS X, other types of ACLs are supported.
	     AC_CACHE_CHECK([for ACL_TYPE_EXTENDED],
	       [gl_cv_acl_ACL_TYPE_EXTENDED],
	       [AC_COMPILE_IFELSE(
[[#include <sys/types.h>
#include <sys/acl.h>
int type = ACL_TYPE_EXTENDED;]],
		  [gl_cv_acl_ACL_TYPE_EXTENDED=yes],
		  [gl_cv_acl_ACL_TYPE_EXTENDED=no])])
	     if test $gl_cv_acl_ACL_TYPE_EXTENDED = yes; then
	       AC_DEFINE([HAVE_ACL_TYPE_EXTENDED], 1,
		 [Define to 1 if the ACL type ACL_TYPE_EXTENDED exists.])
	     fi
	   else
	     LIB_ACL=
	   fi
	  ])
      fi

      dnl Test for Solaris API (Solaris, Cygwin).
      if test $use_acl = 0; then
	AC_CHECK_FUNCS([acl])
	if test $ac_cv_func_acl = yes; then
	  AC_SEARCH_LIBS([acl_trivial], [sec],
	    [if test "$ac_cv_search_acl_trivial" != "none required"; then
	       LIB_ACL=$ac_cv_search_acl_trivial
	     fi
	    ])
	  AC_CHECK_FUNCS([acl_trivial])
	  use_acl=1
	fi
      fi

      dnl Test for HP-UX API.
      if test $use_acl = 0 || test "$ac_cv_func_acl" = yes; then
	AC_CHECK_FUNCS([getacl])
	if test $ac_cv_func_getacl = yes; then
	  use_acl=1
	fi
      fi

      dnl Test for AIX API (AIX 5.3 or newer).
      if test $use_acl = 0; then
	AC_CHECK_FUNCS([aclx_get])
	if test $ac_cv_func_aclx_get = yes; then
	  use_acl=1
	fi
      fi

      dnl Test for older AIX API.
      if test $use_acl = 0 || test "$ac_cv_func_aclx_get" = yes; then
	AC_CHECK_FUNCS([statacl])
	if test $ac_cv_func_statacl = yes; then
	  use_acl=1
	fi
      fi

      LIBS=$ac_save_LIBS
    fi
    if test "x$enable_acl$use_acl" = "xyes0"; then
      AC_MSG_ERROR([ACLs enabled but support not detected])
    fi
  fi
  AC_SUBST([LIB_ACL])
  AC_DEFINE_UNQUOTED([USE_ACL], [$use_acl],
    [Define to nonzero if you want access control list support.])
  USE_ACL=$use_acl
  AC_SUBST([USE_ACL])
])

# gl_ACL_GET_FILE(IF-WORKS, IF-NOT)
# -------------------------------------
# If `acl_get_file' works (does not have a particular bug),
# run IF-WORKS, otherwise, IF-NOT.
# This tests for a Darwin 8.7.0 bug, whereby acl_get_file returns NULL,
# but sets errno = ENOENT for an existing file or directory.
AC_DEFUN([gl_ACL_GET_FILE],
[
  AC_CACHE_CHECK([for working acl_get_file], gl_cv_func_working_acl_get_file,
    [AC_RUN_IFELSE(
       [AC_LANG_PROGRAM(
	  [[#include <sys/types.h>
	   #include <sys/acl.h>
	   #include <errno.h>
	  ]],
	  [[return !! (!acl_get_file (".", ACL_TYPE_ACCESS)
		       && errno == ENOENT);]])],
       [gl_cv_func_working_acl_get_file=yes],
       [gl_cv_func_working_acl_get_file=no],
       [gl_cv_func_working_acl_get_file=cross-compiling])])

  AS_IF([test $gl_cv_func_working_acl_get_file = yes], [$1], [$2])
])