dnl $Id: aclocal.m4,v 1.19 2010/07/15 22:01:12 tom Exp $
dnl autoconf macros for 'diffstat'
dnl
dnl Copyright 2003-2009,2010 Thomas E. Dickey
dnl
dnl See also
dnl http://invisible-island.net/autoconf/
dnl
dnl ---------------------------------------------------------------------------
dnl ---------------------------------------------------------------------------
dnl CF_ADD_CFLAGS version: 10 updated: 2010/05/26 05:38:42
dnl -------------
dnl Copy non-preprocessor flags to $CFLAGS, preprocessor flags to $CPPFLAGS
dnl The second parameter if given makes this macro verbose.
dnl
dnl Put any preprocessor definitions that use quoted strings in $EXTRA_CPPFLAGS,
dnl to simplify use of $CPPFLAGS in compiler checks, etc., that are easily
dnl confused by the quotes (which require backslashes to keep them usable).
AC_DEFUN([CF_ADD_CFLAGS],
[
cf_fix_cppflags=no
cf_new_cflags=
cf_new_cppflags=
cf_new_extra_cppflags=

for cf_add_cflags in $1
do
case $cf_fix_cppflags in
no)
	case $cf_add_cflags in #(vi
	-undef|-nostdinc*|-I*|-D*|-U*|-E|-P|-C) #(vi
		case $cf_add_cflags in
		-D*)
			cf_tst_cflags=`echo ${cf_add_cflags} |sed -e 's/^-D[[^=]]*='\''\"[[^"]]*//'`

			test "${cf_add_cflags}" != "${cf_tst_cflags}" \
				&& test -z "${cf_tst_cflags}" \
				&& cf_fix_cppflags=yes

			if test $cf_fix_cppflags = yes ; then
				cf_new_extra_cppflags="$cf_new_extra_cppflags $cf_add_cflags"
				continue
			elif test "${cf_tst_cflags}" = "\"'" ; then
				cf_new_extra_cppflags="$cf_new_extra_cppflags $cf_add_cflags"
				continue
			fi
			;;
		esac
		case "$CPPFLAGS" in
		*$cf_add_cflags) #(vi
			;;
		*) #(vi
			case $cf_add_cflags in #(vi
			-D*)
				cf_tst_cppflags=`echo "x$cf_add_cflags" | sed -e 's/^...//' -e 's/=.*//'`
				CF_REMOVE_DEFINE(CPPFLAGS,$CPPFLAGS,$cf_tst_cppflags)
				;;
			esac
			cf_new_cppflags="$cf_new_cppflags $cf_add_cflags"
			;;
		esac
		;;
	*)
		cf_new_cflags="$cf_new_cflags $cf_add_cflags"
		;;
	esac
	;;
yes)
	cf_new_extra_cppflags="$cf_new_extra_cppflags $cf_add_cflags"

	cf_tst_cflags=`echo ${cf_add_cflags} |sed -e 's/^[[^"]]*"'\''//'`

	test "${cf_add_cflags}" != "${cf_tst_cflags}" \
		&& test -z "${cf_tst_cflags}" \
		&& cf_fix_cppflags=no
	;;
esac
done

if test -n "$cf_new_cflags" ; then
	ifelse([$2],,,[CF_VERBOSE(add to \$CFLAGS $cf_new_cflags)])
	CFLAGS="$CFLAGS $cf_new_cflags"
fi

if test -n "$cf_new_cppflags" ; then
	ifelse([$2],,,[CF_VERBOSE(add to \$CPPFLAGS $cf_new_cppflags)])
	CPPFLAGS="$CPPFLAGS $cf_new_cppflags"
fi

if test -n "$cf_new_extra_cppflags" ; then
	ifelse([$2],,,[CF_VERBOSE(add to \$EXTRA_CPPFLAGS $cf_new_extra_cppflags)])
	EXTRA_CPPFLAGS="$cf_new_extra_cppflags $EXTRA_CPPFLAGS"
fi

AC_SUBST(EXTRA_CPPFLAGS)

])dnl
dnl ---------------------------------------------------------------------------
dnl CF_ANSI_CC_CHECK version: 9 updated: 2001/12/30 17:53:34
dnl ----------------
dnl This is adapted from the macros 'fp_PROG_CC_STDC' and 'fp_C_PROTOTYPES'
dnl in the sharutils 4.2 distribution.
AC_DEFUN([CF_ANSI_CC_CHECK],
[
AC_CACHE_CHECK(for ${CC-cc} option to accept ANSI C, cf_cv_ansi_cc,[
cf_cv_ansi_cc=no
cf_save_CFLAGS="$CFLAGS"
cf_save_CPPFLAGS="$CPPFLAGS"
# Don't try gcc -ansi; that turns off useful extensions and
# breaks some systems' header files.
# AIX			-qlanglvl=ansi
# Ultrix and OSF/1	-std1
# HP-UX			-Aa -D_HPUX_SOURCE
# SVR4			-Xc
# UnixWare 1.2		(cannot use -Xc, since ANSI/POSIX clashes)
for cf_arg in "-DCC_HAS_PROTOS" \
	"" \
	-qlanglvl=ansi \
	-std1 \
	-Ae \
	"-Aa -D_HPUX_SOURCE" \
	-Xc
do
	CF_ADD_CFLAGS($cf_arg)
	AC_TRY_COMPILE(
[
#ifndef CC_HAS_PROTOS
#if !defined(__STDC__) || (__STDC__ != 1)
choke me
#endif
#endif
],[
	int test (int i, double x);
	struct s1 {int (*f) (int a);};
	struct s2 {int (*f) (double a);};],
	[cf_cv_ansi_cc="$cf_arg"; break])
done
CFLAGS="$cf_save_CFLAGS"
CPPFLAGS="$cf_save_CPPFLAGS"
])

if test "$cf_cv_ansi_cc" != "no"; then
if test ".$cf_cv_ansi_cc" != ".-DCC_HAS_PROTOS"; then
	CF_ADD_CFLAGS($cf_cv_ansi_cc)
else
	AC_DEFINE(CC_HAS_PROTOS)
fi
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_ANSI_CC_REQD version: 4 updated: 2008/03/23 14:48:54
dnl ---------------
dnl For programs that must use an ANSI compiler, obtain compiler options that
dnl will make it recognize prototypes.  We'll do preprocessor checks in other
dnl macros, since tools such as unproto can fake prototypes, but only part of
dnl the preprocessor.
AC_DEFUN([CF_ANSI_CC_REQD],
[AC_REQUIRE([CF_ANSI_CC_CHECK])
if test "$cf_cv_ansi_cc" = "no"; then
	AC_MSG_ERROR(
[Your compiler does not appear to recognize prototypes.
You have the following choices:
	a. adjust your compiler options
	b. get an up-to-date compiler
	c. use a wrapper such as unproto])
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_ARG_DISABLE version: 3 updated: 1999/03/30 17:24:31
dnl --------------
dnl Allow user to disable a normally-on option.
AC_DEFUN([CF_ARG_DISABLE],
[CF_ARG_OPTION($1,[$2],[$3],[$4],yes)])dnl
dnl ---------------------------------------------------------------------------
dnl CF_ARG_OPTION version: 4 updated: 2010/05/26 05:38:42
dnl -------------
dnl Restricted form of AC_ARG_ENABLE that ensures user doesn't give bogus
dnl values.
dnl
dnl Parameters:
dnl $1 = option name
dnl $2 = help-string
dnl $3 = action to perform if option is not default
dnl $4 = action if perform if option is default
dnl $5 = default option value (either 'yes' or 'no')
AC_DEFUN([CF_ARG_OPTION],
[AC_ARG_ENABLE([$1],[$2],[test "$enableval" != ifelse([$5],no,yes,no) && enableval=ifelse([$5],no,no,yes)
  if test "$enableval" != "$5" ; then
ifelse([$3],,[    :]dnl
,[    $3]) ifelse([$4],,,[
  else
    $4])
  fi],[enableval=$5 ifelse([$4],,,[
  $4
])dnl
  ])])dnl
dnl ---------------------------------------------------------------------------
dnl CF_CHECK_CACHE version: 11 updated: 2008/03/23 14:45:59
dnl --------------
dnl Check if we're accidentally using a cache from a different machine.
dnl Derive the system name, as a check for reusing the autoconf cache.
dnl
dnl If we've packaged config.guess and config.sub, run that (since it does a
dnl better job than uname).  Normally we'll use AC_CANONICAL_HOST, but allow
dnl an extra parameter that we may override, e.g., for AC_CANONICAL_SYSTEM
dnl which is useful in cross-compiles.
dnl
dnl Note: we would use $ac_config_sub, but that is one of the places where
dnl autoconf 2.5x broke compatibility with autoconf 2.13
AC_DEFUN([CF_CHECK_CACHE],
[
if test -f $srcdir/config.guess || test -f $ac_aux_dir/config.guess ; then
	ifelse([$1],,[AC_CANONICAL_HOST],[$1])
	system_name="$host_os"
else
	system_name="`(uname -s -r) 2>/dev/null`"
	if test -z "$system_name" ; then
		system_name="`(hostname) 2>/dev/null`"
	fi
fi
test -n "$system_name" && AC_DEFINE_UNQUOTED(SYSTEM_NAME,"$system_name")
AC_CACHE_VAL(cf_cv_system_name,[cf_cv_system_name="$system_name"])

test -z "$system_name" && system_name="$cf_cv_system_name"
test -n "$cf_cv_system_name" && AC_MSG_RESULT(Configuring for $cf_cv_system_name)

if test ".$system_name" != ".$cf_cv_system_name" ; then
	AC_MSG_RESULT(Cached system name ($system_name) does not agree with actual ($cf_cv_system_name))
	AC_MSG_ERROR("Please remove config.cache and try again.")
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_DISABLE_ECHO version: 11 updated: 2009/12/13 13:16:57
dnl ---------------
dnl You can always use "make -n" to see the actual options, but it's hard to
dnl pick out/analyze warning messages when the compile-line is long.
dnl
dnl Sets:
dnl	ECHO_LT - symbol to control if libtool is verbose
dnl	ECHO_LD - symbol to prefix "cc -o" lines
dnl	RULE_CC - symbol to put before implicit "cc -c" lines (e.g., .c.o)
dnl	SHOW_CC - symbol to put before explicit "cc -c" lines
dnl	ECHO_CC - symbol to put before any "cc" line
dnl
AC_DEFUN([CF_DISABLE_ECHO],[
AC_MSG_CHECKING(if you want to see long compiling messages)
CF_ARG_DISABLE(echo,
	[  --disable-echo          display "compiling" commands],
	[
    ECHO_LT='--silent'
    ECHO_LD='@echo linking [$]@;'
    RULE_CC='@echo compiling [$]<'
    SHOW_CC='@echo compiling [$]@'
    ECHO_CC='@'
],[
    ECHO_LT=''
    ECHO_LD=''
    RULE_CC=''
    SHOW_CC=''
    ECHO_CC=''
])
AC_MSG_RESULT($enableval)
AC_SUBST(ECHO_LT)
AC_SUBST(ECHO_LD)
AC_SUBST(RULE_CC)
AC_SUBST(SHOW_CC)
AC_SUBST(ECHO_CC)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_DISABLE_LEAKS version: 5 updated: 2010/03/13 15:14:55
dnl ----------------
dnl Combine no-leak checks with the libraries or tools that are used for the
dnl checks.
AC_DEFUN([CF_DISABLE_LEAKS],[

AC_REQUIRE([CF_WITH_DMALLOC])
AC_REQUIRE([CF_WITH_DBMALLOC])
AC_REQUIRE([CF_WITH_VALGRIND])

AC_MSG_CHECKING(if you want to perform memory-leak testing)
AC_ARG_ENABLE(leaks,
	[  --disable-leaks         test: free permanent memory, analyze leaks],
	[if test "x$enableval" = xno; then with_no_leaks=yes; else with_no_leaks=no; fi],
	: ${with_no_leaks:=no})
AC_MSG_RESULT($with_no_leaks)

if test "$with_no_leaks" = yes ; then
	AC_DEFINE(NO_LEAKS)
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GCC_ATTRIBUTES version: 13 updated: 2009/08/11 20:19:56
dnl -----------------
dnl Test for availability of useful gcc __attribute__ directives to quiet
dnl compiler warnings.  Though useful, not all are supported -- and contrary
dnl to documentation, unrecognized directives cause older compilers to barf.
AC_DEFUN([CF_GCC_ATTRIBUTES],
[
if test "$GCC" = yes
then
cat > conftest.i <<EOF
#ifndef GCC_PRINTF
#define GCC_PRINTF 0
#endif
#ifndef GCC_SCANF
#define GCC_SCANF 0
#endif
#ifndef GCC_NORETURN
#define GCC_NORETURN /* nothing */
#endif
#ifndef GCC_UNUSED
#define GCC_UNUSED /* nothing */
#endif
EOF
if test "$GCC" = yes
then
	AC_CHECKING([for $CC __attribute__ directives])
cat > conftest.$ac_ext <<EOF
#line __oline__ "${as_me-configure}"
#include "confdefs.h"
#include "conftest.h"
#include "conftest.i"
#if	GCC_PRINTF
#define GCC_PRINTFLIKE(fmt,var) __attribute__((format(printf,fmt,var)))
#else
#define GCC_PRINTFLIKE(fmt,var) /*nothing*/
#endif
#if	GCC_SCANF
#define GCC_SCANFLIKE(fmt,var)  __attribute__((format(scanf,fmt,var)))
#else
#define GCC_SCANFLIKE(fmt,var)  /*nothing*/
#endif
extern void wow(char *,...) GCC_SCANFLIKE(1,2);
extern void oops(char *,...) GCC_PRINTFLIKE(1,2) GCC_NORETURN;
extern void foo(void) GCC_NORETURN;
int main(int argc GCC_UNUSED, char *argv[[]] GCC_UNUSED) { return 0; }
EOF
	cf_printf_attribute=no
	cf_scanf_attribute=no
	for cf_attribute in scanf printf unused noreturn
	do
		CF_UPPER(cf_ATTRIBUTE,$cf_attribute)
		cf_directive="__attribute__(($cf_attribute))"
		echo "checking for $CC $cf_directive" 1>&AC_FD_CC

		case $cf_attribute in #(vi
		printf) #(vi
			cf_printf_attribute=yes
			cat >conftest.h <<EOF
#define GCC_$cf_ATTRIBUTE 1
EOF
			;;
		scanf) #(vi
			cf_scanf_attribute=yes
			cat >conftest.h <<EOF
#define GCC_$cf_ATTRIBUTE 1
EOF
			;;
		*) #(vi
			cat >conftest.h <<EOF
#define GCC_$cf_ATTRIBUTE $cf_directive
EOF
			;;
		esac

		if AC_TRY_EVAL(ac_compile); then
			test -n "$verbose" && AC_MSG_RESULT(... $cf_attribute)
			cat conftest.h >>confdefs.h
			case $cf_attribute in #(vi
			printf) #(vi
				if test "$cf_printf_attribute" = no ; then
					cat >>confdefs.h <<EOF
#define GCC_PRINTFLIKE(fmt,var) /* nothing */
EOF
				else
					cat >>confdefs.h <<EOF
#define GCC_PRINTFLIKE(fmt,var) __attribute__((format(printf,fmt,var)))
EOF
				fi
				;;
			scanf) #(vi
				if test "$cf_scanf_attribute" = no ; then
					cat >>confdefs.h <<EOF
#define GCC_SCANFLIKE(fmt,var) /* nothing */
EOF
				else
					cat >>confdefs.h <<EOF
#define GCC_SCANFLIKE(fmt,var)  __attribute__((format(scanf,fmt,var)))
EOF
				fi
				;;
			esac
		fi
	done
else
	fgrep define conftest.i >>confdefs.h
fi
rm -rf conftest*
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GCC_VERSION version: 5 updated: 2010/04/24 11:02:31
dnl --------------
dnl Find version of gcc
AC_DEFUN([CF_GCC_VERSION],[
AC_REQUIRE([AC_PROG_CC])
GCC_VERSION=none
if test "$GCC" = yes ; then
	AC_MSG_CHECKING(version of $CC)
	GCC_VERSION="`${CC} --version 2>/dev/null | sed -e '2,$d' -e 's/^.*(GCC) //' -e 's/^[[^0-9.]]*//' -e 's/[[^0-9.]].*//'`"
	test -z "$GCC_VERSION" && GCC_VERSION=unknown
	AC_MSG_RESULT($GCC_VERSION)
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GCC_WARNINGS version: 25 updated: 2010/04/24 11:03:31
dnl ---------------
dnl Check if the compiler supports useful warning options.  There's a few that
dnl we don't use, simply because they're too noisy:
dnl
dnl	-Wconversion (useful in older versions of gcc, but not in gcc 2.7.x)
dnl	-Wredundant-decls (system headers make this too noisy)
dnl	-Wtraditional (combines too many unrelated messages, only a few useful)
dnl	-Wwrite-strings (too noisy, but should review occasionally).  This
dnl		is enabled for ncurses using "--enable-const".
dnl	-pedantic
dnl
dnl Parameter:
dnl	$1 is an optional list of gcc warning flags that a particular
dnl		application might want to use, e.g., "no-unused" for
dnl		-Wno-unused
dnl Special:
dnl	If $with_ext_const is "yes", add a check for -Wwrite-strings
dnl
AC_DEFUN([CF_GCC_WARNINGS],
[
AC_REQUIRE([CF_GCC_VERSION])
CF_INTEL_COMPILER(GCC,INTEL_COMPILER,CFLAGS)

cat > conftest.$ac_ext <<EOF
#line __oline__ "${as_me-configure}"
int main(int argc, char *argv[[]]) { return (argv[[argc-1]] == 0) ; }
EOF

if test "$INTEL_COMPILER" = yes
then
# The "-wdXXX" options suppress warnings:
# remark #1419: external declaration in primary source file
# remark #1683: explicit conversion of a 64-bit integral type to a smaller integral type (potential portability problem)
# remark #1684: conversion from pointer to same-sized integral type (potential portability problem)
# remark #193: zero used for undefined preprocessing identifier
# remark #593: variable "curs_sb_left_arrow" was set but never used
# remark #810: conversion from "int" to "Dimension={unsigned short}" may lose significant bits
# remark #869: parameter "tw" was never referenced
# remark #981: operands are evaluated in unspecified order
# warning #279: controlling expression is constant

	AC_CHECKING([for $CC warning options])
	cf_save_CFLAGS="$CFLAGS"
	EXTRA_CFLAGS="-Wall"
	for cf_opt in \
		wd1419 \
		wd1683 \
		wd1684 \
		wd193 \
		wd593 \
		wd279 \
		wd810 \
		wd869 \
		wd981
	do
		CFLAGS="$cf_save_CFLAGS $EXTRA_CFLAGS -$cf_opt"
		if AC_TRY_EVAL(ac_compile); then
			test -n "$verbose" && AC_MSG_RESULT(... -$cf_opt)
			EXTRA_CFLAGS="$EXTRA_CFLAGS -$cf_opt"
		fi
	done
	CFLAGS="$cf_save_CFLAGS"

elif test "$GCC" = yes
then
	AC_CHECKING([for $CC warning options])
	cf_save_CFLAGS="$CFLAGS"
	EXTRA_CFLAGS=
	cf_warn_CONST=""
	test "$with_ext_const" = yes && cf_warn_CONST="Wwrite-strings"
	for cf_opt in W Wall \
		Wbad-function-cast \
		Wcast-align \
		Wcast-qual \
		Winline \
		Wmissing-declarations \
		Wmissing-prototypes \
		Wnested-externs \
		Wpointer-arith \
		Wshadow \
		Wstrict-prototypes \
		Wundef $cf_warn_CONST $1
	do
		CFLAGS="$cf_save_CFLAGS $EXTRA_CFLAGS -$cf_opt"
		if AC_TRY_EVAL(ac_compile); then
			test -n "$verbose" && AC_MSG_RESULT(... -$cf_opt)
			case $cf_opt in #(vi
			Wcast-qual) #(vi
				CPPFLAGS="$CPPFLAGS -DXTSTRINGDEFINES"
				;;
			Winline) #(vi
				case $GCC_VERSION in
				[[34]].*)
					CF_VERBOSE(feature is broken in gcc $GCC_VERSION)
					continue;;
				esac
				;;
			esac
			EXTRA_CFLAGS="$EXTRA_CFLAGS -$cf_opt"
		fi
	done
	CFLAGS="$cf_save_CFLAGS"
fi
rm -f conftest*

AC_SUBST(EXTRA_CFLAGS)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GETOPT_HEADER version: 4 updated: 2009/08/31 20:07:52
dnl ----------------
dnl Check for getopt's variables which are commonly defined in stdlib.h,
dnl unistd.h or (nonstandard) in getopt.h
AC_DEFUN([CF_GETOPT_HEADER],
[
AC_HAVE_HEADERS(unistd.h getopt.h)
AC_CACHE_CHECK(for header declaring getopt variables,cf_cv_getopt_header,[
cf_cv_getopt_header=none
for cf_header in stdio.h stdlib.h unistd.h getopt.h
do
AC_TRY_COMPILE([
#include <$cf_header>],
[int x = optind; char *y = optarg],
[cf_cv_getopt_header=$cf_header
 break])
done
])
if test $cf_cv_getopt_header != none ; then
	AC_DEFINE(HAVE_GETOPT_HEADER)
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GNU_SOURCE version: 6 updated: 2005/07/09 13:23:07
dnl -------------
dnl Check if we must define _GNU_SOURCE to get a reasonable value for
dnl _XOPEN_SOURCE, upon which many POSIX definitions depend.  This is a defect
dnl (or misfeature) of glibc2, which breaks portability of many applications,
dnl since it is interwoven with GNU extensions.
dnl
dnl Well, yes we could work around it...
AC_DEFUN([CF_GNU_SOURCE],
[
AC_CACHE_CHECK(if we must define _GNU_SOURCE,cf_cv_gnu_source,[
AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_gnu_source=no],
	[cf_save="$CPPFLAGS"
	 CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
	 AC_TRY_COMPILE([#include <sys/types.h>],[
#ifdef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_gnu_source=no],
	[cf_cv_gnu_source=yes])
	CPPFLAGS="$cf_save"
	])
])
test "$cf_cv_gnu_source" = yes && CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_GNU_SOURCE version: 6 updated: 2005/07/09 13:23:07
dnl -------------
dnl Check if we must define _GNU_SOURCE to get a reasonable value for
dnl _XOPEN_SOURCE, upon which many POSIX definitions depend.  This is a defect
dnl (or misfeature) of glibc2, which breaks portability of many applications,
dnl since it is interwoven with GNU extensions.
dnl
dnl Well, yes we could work around it...
AC_DEFUN([CF_GNU_SOURCE],
[
AC_CACHE_CHECK(if we must define _GNU_SOURCE,cf_cv_gnu_source,[
AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_gnu_source=no],
	[cf_save="$CPPFLAGS"
	 CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
	 AC_TRY_COMPILE([#include <sys/types.h>],[
#ifdef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_gnu_source=no],
	[cf_cv_gnu_source=yes])
	CPPFLAGS="$cf_save"
	])
])
test "$cf_cv_gnu_source" = yes && CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_INTEL_COMPILER version: 4 updated: 2010/05/26 05:38:42
dnl -----------------
dnl Check if the given compiler is really the Intel compiler for Linux.  It
dnl tries to imitate gcc, but does not return an error when it finds a mismatch
dnl between prototypes, e.g., as exercised by CF_MISSING_CHECK.
dnl
dnl This macro should be run "soon" after AC_PROG_CC or AC_PROG_CPLUSPLUS, to
dnl ensure that it is not mistaken for gcc/g++.  It is normally invoked from
dnl the wrappers for gcc and g++ warnings.
dnl
dnl $1 = GCC (default) or GXX
dnl $2 = INTEL_COMPILER (default) or INTEL_CPLUSPLUS
dnl $3 = CFLAGS (default) or CXXFLAGS
AC_DEFUN([CF_INTEL_COMPILER],[
ifelse([$2],,INTEL_COMPILER,[$2])=no

if test "$ifelse([$1],,[$1],GCC)" = yes ; then
	case $host_os in
	linux*|gnu*)
		AC_MSG_CHECKING(if this is really Intel ifelse([$1],GXX,C++,C) compiler)
		cf_save_CFLAGS="$ifelse([$3],,CFLAGS,[$3])"
		ifelse([$3],,CFLAGS,[$3])="$ifelse([$3],,CFLAGS,[$3]) -no-gcc"
		AC_TRY_COMPILE([],[
#ifdef __INTEL_COMPILER
#else
make an error
#endif
],[ifelse([$2],,INTEL_COMPILER,[$2])=yes
cf_save_CFLAGS="$cf_save_CFLAGS -we147 -no-gcc"
],[])
		ifelse([$3],,CFLAGS,[$3])="$cf_save_CFLAGS"
		AC_MSG_RESULT($ifelse([$2],,INTEL_COMPILER,[$2]))
		;;
	esac
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_MAKE_TAGS version: 5 updated: 2010/04/03 20:07:32
dnl ------------
dnl Generate tags/TAGS targets for makefiles.  Do not generate TAGS if we have
dnl a monocase filesystem.
AC_DEFUN([CF_MAKE_TAGS],[
AC_REQUIRE([CF_MIXEDCASE_FILENAMES])

AC_CHECK_PROGS(CTAGS, exctags ctags)
AC_CHECK_PROGS(ETAGS, exetags etags)

AC_CHECK_PROG(MAKE_LOWER_TAGS, ${CTAGS-ctags}, yes, no)

if test "$cf_cv_mixedcase" = yes ; then
	AC_CHECK_PROG(MAKE_UPPER_TAGS, ${ETAGS-etags}, yes, no)
else
	MAKE_UPPER_TAGS=no
fi

if test "$MAKE_UPPER_TAGS" = yes ; then
	MAKE_UPPER_TAGS=
else
	MAKE_UPPER_TAGS="#"
fi

if test "$MAKE_LOWER_TAGS" = yes ; then
	MAKE_LOWER_TAGS=
else
	MAKE_LOWER_TAGS="#"
fi

AC_SUBST(CTAGS)
AC_SUBST(ETAGS)

AC_SUBST(MAKE_UPPER_TAGS)
AC_SUBST(MAKE_LOWER_TAGS)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_MIXEDCASE_FILENAMES version: 3 updated: 2003/09/20 17:07:55
dnl ----------------------
dnl Check if the file-system supports mixed-case filenames.  If we're able to
dnl create a lowercase name and see it as uppercase, it doesn't support that.
AC_DEFUN([CF_MIXEDCASE_FILENAMES],
[
AC_CACHE_CHECK(if filesystem supports mixed-case filenames,cf_cv_mixedcase,[
if test "$cross_compiling" = yes ; then
	case $target_alias in #(vi
	*-os2-emx*|*-msdosdjgpp*|*-cygwin*|*-mingw32*|*-uwin*) #(vi
		cf_cv_mixedcase=no
		;;
	*)
		cf_cv_mixedcase=yes
		;;
	esac
else
	rm -f conftest CONFTEST
	echo test >conftest
	if test -f CONFTEST ; then
		cf_cv_mixedcase=no
	else
		cf_cv_mixedcase=yes
	fi
	rm -f conftest CONFTEST
fi
])
test "$cf_cv_mixedcase" = yes && AC_DEFINE(MIXEDCASE_FILENAMES)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_MSG_LOG version: 4 updated: 2007/07/29 09:55:12
dnl ----------
dnl Write a debug message to config.log, along with the line number in the
dnl configure script.
AC_DEFUN([CF_MSG_LOG],[
echo "${as_me-configure}:__oline__: testing $* ..." 1>&AC_FD_CC
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_NO_LEAKS_OPTION version: 4 updated: 2006/12/16 14:24:05
dnl ------------------
dnl see CF_WITH_NO_LEAKS
AC_DEFUN([CF_NO_LEAKS_OPTION],[
AC_MSG_CHECKING(if you want to use $1 for testing)
AC_ARG_WITH($1,
	[$2],
	[AC_DEFINE($3)ifelse([$4],,[
	 $4
])
	: ${with_cflags:=-g}
	: ${with_no_leaks:=yes}
	 with_$1=yes],
	[with_$1=])
AC_MSG_RESULT(${with_$1:-no})

case .$with_cflags in #(vi
.*-g*)
	case .$CFLAGS in #(vi
	.*-g*) #(vi
		;;
	*)
		CF_ADD_CFLAGS([-g])
		;;
	esac
	;;
esac
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PATHSEP version: 5 updated: 2010/05/26 05:38:42
dnl ----------
dnl Provide a value for the $PATH and similar separator
AC_DEFUN([CF_PATHSEP],
[
	case $cf_cv_system_name in
	os2*)	PATH_SEPARATOR=';'  ;;
	*)	PATH_SEPARATOR=':'  ;;
	esac
ifelse([$1],,,[$1=$PATH_SEPARATOR])
	AC_SUBST(PATH_SEPARATOR)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PATH_PROG version: 7 updated: 2009/01/11 20:34:16
dnl ------------
dnl Check for a given program, defining corresponding symbol.
dnl	$1 = environment variable, which is suffixed by "_PATH" in the #define.
dnl	$2 = program name to find.
dnl	$3 = optional list of additional program names to test.
dnl
dnl If there is more than one token in the result, #define the remaining tokens
dnl to $1_ARGS.  We need this for 'install' in particular.
dnl
dnl FIXME: we should allow this to be overridden by environment variables
dnl
AC_DEFUN([CF_PATH_PROG],[
AC_REQUIRE([CF_PATHSEP])
test -z "[$]$1" && $1=$2
AC_PATH_PROGS($1,[$]$1 $2 $3,[$]$1)

cf_path_prog=""
cf_path_args=""
IFS="${IFS= 	}"; cf_save_ifs="$IFS"; IFS="${IFS}$PATH_SEPARATOR"
for cf_temp in $ac_cv_path_$1
do
	if test -z "$cf_path_prog" ; then
		if test "$with_full_paths" = yes ; then
			CF_PATH_SYNTAX(cf_temp,break)
			cf_path_prog="$cf_temp"
		else
			cf_path_prog="`basename $cf_temp`"
		fi
	elif test -z "$cf_path_args" ; then
		cf_path_args="$cf_temp"
	else
		cf_path_args="$cf_path_args $cf_temp"
	fi
done
IFS="$cf_save_ifs"

if test -n "$cf_path_prog" ; then
	CF_MSG_LOG(defining path for ${cf_path_prog})
	AC_DEFINE_UNQUOTED($1_PATH,"$cf_path_prog")
	test -n "$cf_path_args" && AC_DEFINE_UNQUOTED($1_ARGS,"$cf_path_args")
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PATH_SYNTAX version: 13 updated: 2010/05/26 05:38:42
dnl --------------
dnl Check the argument to see that it looks like a pathname.  Rewrite it if it
dnl begins with one of the prefix/exec_prefix variables, and then again if the
dnl result begins with 'NONE'.  This is necessary to work around autoconf's
dnl delayed evaluation of those symbols.
AC_DEFUN([CF_PATH_SYNTAX],[
if test "x$prefix" != xNONE; then
  cf_path_syntax="$prefix"
else
  cf_path_syntax="$ac_default_prefix"
fi

case ".[$]$1" in #(vi
.\[$]\(*\)*|.\'*\'*) #(vi
  ;;
..|./*|.\\*) #(vi
  ;;
.[[a-zA-Z]]:[[\\/]]*) #(vi OS/2 EMX
  ;;
.\[$]{*prefix}*) #(vi
  eval $1="[$]$1"
  case ".[$]$1" in #(vi
  .NONE/*)
    $1=`echo [$]$1 | sed -e s%NONE%$cf_path_syntax%`
    ;;
  esac
  ;; #(vi
.no|.NONE/*)
  $1=`echo [$]$1 | sed -e s%NONE%$cf_path_syntax%`
  ;;
*)
  ifelse([$2],,[AC_MSG_ERROR([expected a pathname, not \"[$]$1\"])],$2)
  ;;
esac
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_POSIX_C_SOURCE version: 8 updated: 2010/05/26 05:38:42
dnl -----------------
dnl Define _POSIX_C_SOURCE to the given level, and _POSIX_SOURCE if needed.
dnl
dnl	POSIX.1-1990				_POSIX_SOURCE
dnl	POSIX.1-1990 and			_POSIX_SOURCE and
dnl		POSIX.2-1992 C-Language			_POSIX_C_SOURCE=2
dnl		Bindings Option
dnl	POSIX.1b-1993				_POSIX_C_SOURCE=199309L
dnl	POSIX.1c-1996				_POSIX_C_SOURCE=199506L
dnl	X/Open 2000				_POSIX_C_SOURCE=200112L
dnl
dnl Parameters:
dnl	$1 is the nominal value for _POSIX_C_SOURCE
AC_DEFUN([CF_POSIX_C_SOURCE],
[
cf_POSIX_C_SOURCE=ifelse([$1],,199506L,[$1])

cf_save_CFLAGS="$CFLAGS"
cf_save_CPPFLAGS="$CPPFLAGS"

CF_REMOVE_DEFINE(cf_trim_CFLAGS,$cf_save_CFLAGS,_POSIX_C_SOURCE)
CF_REMOVE_DEFINE(cf_trim_CPPFLAGS,$cf_save_CPPFLAGS,_POSIX_C_SOURCE)

AC_CACHE_CHECK(if we should define _POSIX_C_SOURCE,cf_cv_posix_c_source,[
	CF_MSG_LOG(if the symbol is already defined go no further)
	AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _POSIX_C_SOURCE
make an error
#endif],
	[cf_cv_posix_c_source=no],
	[cf_want_posix_source=no
	 case .$cf_POSIX_C_SOURCE in #(vi
	 .[[12]]??*) #(vi
		cf_cv_posix_c_source="-D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE"
		;;
	 .2) #(vi
		cf_cv_posix_c_source="-D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE"
		cf_want_posix_source=yes
		;;
	 .*)
		cf_want_posix_source=yes
		;;
	 esac
	 if test "$cf_want_posix_source" = yes ; then
		AC_TRY_COMPILE([#include <sys/types.h>],[
#ifdef _POSIX_SOURCE
make an error
#endif],[],
		cf_cv_posix_c_source="$cf_cv_posix_c_source -D_POSIX_SOURCE")
	 fi
	 CF_MSG_LOG(ifdef from value $cf_POSIX_C_SOURCE)
	 CFLAGS="$cf_trim_CFLAGS"
	 CPPFLAGS="$cf_trim_CPPFLAGS $cf_cv_posix_c_source"
	 CF_MSG_LOG(if the second compile does not leave our definition intact error)
	 AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _POSIX_C_SOURCE
make an error
#endif],,
	 [cf_cv_posix_c_source=no])
	 CFLAGS="$cf_save_CFLAGS"
	 CPPFLAGS="$cf_save_CPPFLAGS"
	])
])

if test "$cf_cv_posix_c_source" != no ; then
	CFLAGS="$cf_trim_CFLAGS"
	CPPFLAGS="$cf_trim_CPPFLAGS"
	CF_ADD_CFLAGS($cf_cv_posix_c_source)
fi

])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PROG_CC_U_D version: 1 updated: 2005/07/14 16:59:30
dnl --------------
dnl Check if C (preprocessor) -U and -D options are processed in the order
dnl given rather than by type of option.  Some compilers insist on apply all
dnl of the -U options after all of the -D options.  Others allow mixing them,
dnl and may predefine symbols that conflict with those we define.
AC_DEFUN([CF_PROG_CC_U_D],
[
AC_CACHE_CHECK(if $CC -U and -D options work together,cf_cv_cc_u_d_options,[
	cf_save_CPPFLAGS="$CPPFLAGS"
	CPPFLAGS="-UU_D_OPTIONS -DU_D_OPTIONS -DD_U_OPTIONS -UD_U_OPTIONS"
	AC_TRY_COMPILE([],[
#ifndef U_D_OPTIONS
make an undefined-error
#endif
#ifdef  D_U_OPTIONS
make a defined-error
#endif
	],[
	cf_cv_cc_u_d_options=yes],[
	cf_cv_cc_u_d_options=no])
	CPPFLAGS="$cf_save_CPPFLAGS"
])
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PROG_EXT version: 10 updated: 2004/01/03 19:28:18
dnl -----------
dnl Compute $PROG_EXT, used for non-Unix ports, such as OS/2 EMX.
AC_DEFUN([CF_PROG_EXT],
[
AC_REQUIRE([CF_CHECK_CACHE])
case $cf_cv_system_name in
os2*)
    CFLAGS="$CFLAGS -Zmt"
    CPPFLAGS="$CPPFLAGS -D__ST_MT_ERRNO__"
    CXXFLAGS="$CXXFLAGS -Zmt"
    # autoconf's macro sets -Zexe and suffix both, which conflict:w
    LDFLAGS="$LDFLAGS -Zmt -Zcrtdll"
    ac_cv_exeext=.exe
    ;;
esac

AC_EXEEXT
AC_OBJEXT

PROG_EXT="$EXEEXT"
AC_SUBST(PROG_EXT)
test -n "$PROG_EXT" && AC_DEFINE_UNQUOTED(PROG_EXT,"$PROG_EXT")
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_PROG_LINT version: 2 updated: 2009/08/12 04:43:14
dnl ------------
AC_DEFUN([CF_PROG_LINT],
[
AC_CHECK_PROGS(LINT, tdlint lint alint splint lclint)
AC_SUBST(LINT_OPTS)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_REMOVE_DEFINE version: 3 updated: 2010/01/09 11:05:50
dnl ----------------
dnl Remove all -U and -D options that refer to the given symbol from a list
dnl of C compiler options.  This works around the problem that not all
dnl compilers process -U and -D options from left-to-right, so a -U option
dnl cannot be used to cancel the effect of a preceding -D option.
dnl
dnl $1 = target (which could be the same as the source variable)
dnl $2 = source (including '$')
dnl $3 = symbol to remove
define([CF_REMOVE_DEFINE],
[
$1=`echo "$2" | \
	sed	-e 's/-[[UD]]'"$3"'\(=[[^ 	]]*\)\?[[ 	]]/ /g' \
		-e 's/-[[UD]]'"$3"'\(=[[^ 	]]*\)\?[$]//g'`
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_STDIO_UNLOCKED version: 3 updated: 2009/10/06 19:54:39
dnl -----------------
dnl The four functions getc_unlocked(), getchar_unlocked(), putc_unlocked(),
dnl putchar_unlocked() are in POSIX.1-2001.
dnl
dnl Test for one or more of the "unlocked" stdio getc/putc functions, and (if
dnl the system requires it to declare the prototype) define _REENTRANT
dnl
dnl $1 = one or more stdio functions to check for existence and prototype.
AC_DEFUN([CF_STDIO_UNLOCKED],
[
cf_stdio_unlocked=no
AC_CHECK_FUNCS(ifelse([$1],,[getc_unlocked putc_unlocked],[$1]),
	[cf_stdio_unlocked=$ac_func])
if test "$cf_stdio_unlocked" != no ; then
	case "$CPPFLAGS" in #(vi
	*-D_REENTRANT*) #(vi
		;;
	*)
	AC_CACHE_CHECK(if we should define _REENTRANT,cf_cv_stdio_unlocked,[
	AC_TRY_COMPILE([#include <stdio.h>],[
		extern void *$cf_stdio_unlocked(void *);
		void *dummy = $cf_stdio_unlocked(0)],
			[cf_cv_stdio_unlocked=yes],
			[cf_cv_stdio_unlocked=no])])
		if test "$cf_cv_stdio_unlocked" = yes ; then
			AC_DEFINE(_REENTRANT)
		fi
		;;
	esac
fi
])
dnl ---------------------------------------------------------------------------
dnl CF_UPPER version: 5 updated: 2001/01/29 23:40:59
dnl --------
dnl Make an uppercase version of a variable
dnl $1=uppercase($2)
AC_DEFUN([CF_UPPER],
[
$1=`echo "$2" | sed y%abcdefghijklmnopqrstuvwxyz./-%ABCDEFGHIJKLMNOPQRSTUVWXYZ___%`
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_VERBOSE version: 3 updated: 2007/07/29 09:55:12
dnl ----------
dnl Use AC_VERBOSE w/o the warnings
AC_DEFUN([CF_VERBOSE],
[test -n "$verbose" && echo "	$1" 1>&AC_FD_MSG
CF_MSG_LOG([$1])
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_DBMALLOC version: 7 updated: 2010/06/21 17:26:47
dnl ----------------
dnl Configure-option for dbmalloc.  The optional parameter is used to override
dnl the updating of $LIBS, e.g., to avoid conflict with subsequent tests.
AC_DEFUN([CF_WITH_DBMALLOC],[
CF_NO_LEAKS_OPTION(dbmalloc,
	[  --with-dbmalloc         test: use Conor Cahill's dbmalloc library],
	[USE_DBMALLOC])

if test "$with_dbmalloc" = yes ; then
	AC_CHECK_HEADER(dbmalloc.h,
		[AC_CHECK_LIB(dbmalloc,[debug_malloc]ifelse([$1],,[],[,$1]))])
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_DMALLOC version: 7 updated: 2010/06/21 17:26:47
dnl ---------------
dnl Configure-option for dmalloc.  The optional parameter is used to override
dnl the updating of $LIBS, e.g., to avoid conflict with subsequent tests.
AC_DEFUN([CF_WITH_DMALLOC],[
CF_NO_LEAKS_OPTION(dmalloc,
	[  --with-dmalloc          test: use Gray Watson's dmalloc library],
	[USE_DMALLOC])

if test "$with_dmalloc" = yes ; then
	AC_CHECK_HEADER(dmalloc.h,
		[AC_CHECK_LIB(dmalloc,[dmalloc_debug]ifelse([$1],,[],[,$1]))])
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_INSTALL_PREFIX version: 3 updated: 2009/03/30 15:01:47
dnl ----------------------
dnl Configure-script option to give a default value for the poorly-chosen name
dnl $(DESTDIR).
AC_DEFUN([CF_WITH_INSTALL_PREFIX],
[
AC_MSG_CHECKING(for install-prefix)
AC_ARG_WITH(install-prefix,
	[  --with-install-prefix=XXX sets DESTDIR, useful for packaging],
	[cf_opt_with_install_prefix=$withval],
	[cf_opt_with_install_prefix=${DESTDIR-no}])
AC_MSG_RESULT($cf_opt_with_install_prefix)
if test "$cf_opt_with_install_prefix" != no ; then
	CF_PATH_SYNTAX(cf_opt_with_install_prefix)
	DESTDIR=$cf_opt_with_install_prefix
fi
AC_SUBST(DESTDIR)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_PURIFY version: 2 updated: 2006/12/14 18:43:43
dnl --------------
AC_DEFUN([CF_WITH_PURIFY],[
CF_NO_LEAKS_OPTION(purify,
	[  --with-purify           test: use Purify],
	[USE_PURIFY],
	[LINK_PREFIX="$LINK_PREFIX purify"])
AC_SUBST(LINK_PREFIX)
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_VALGRIND version: 1 updated: 2006/12/14 18:00:21
dnl ----------------
AC_DEFUN([CF_WITH_VALGRIND],[
CF_NO_LEAKS_OPTION(valgrind,
	[  --with-valgrind         test: use valgrind],
	[USE_VALGRIND])
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_WITH_WARNINGS version: 5 updated: 2004/07/23 14:40:34
dnl ----------------
dnl Combine the checks for gcc features into a configure-script option
dnl
dnl Parameters:
dnl	$1 - see CF_GCC_WARNINGS
AC_DEFUN([CF_WITH_WARNINGS],
[
if ( test "$GCC" = yes || test "$GXX" = yes )
then
AC_MSG_CHECKING(if you want to check for gcc warnings)
AC_ARG_WITH(warnings,
	[  --with-warnings         test: turn on gcc warnings],
	[cf_opt_with_warnings=$withval],
	[cf_opt_with_warnings=no])
AC_MSG_RESULT($cf_opt_with_warnings)
if test "$cf_opt_with_warnings" != no ; then
	CF_GCC_ATTRIBUTES
	CF_GCC_WARNINGS([$1])
fi
fi
])dnl
dnl ---------------------------------------------------------------------------
dnl CF_XOPEN_SOURCE version: 34 updated: 2010/05/26 05:38:42
dnl ---------------
dnl Try to get _XOPEN_SOURCE defined properly that we can use POSIX functions,
dnl or adapt to the vendor's definitions to get equivalent functionality,
dnl without losing the common non-POSIX features.
dnl
dnl Parameters:
dnl	$1 is the nominal value for _XOPEN_SOURCE
dnl	$2 is the nominal value for _POSIX_C_SOURCE
AC_DEFUN([CF_XOPEN_SOURCE],[

cf_XOPEN_SOURCE=ifelse([$1],,500,[$1])
cf_POSIX_C_SOURCE=ifelse([$2],,199506L,[$2])
cf_xopen_source=

case $host_os in #(vi
aix[[456]]*) #(vi
	cf_xopen_source="-D_ALL_SOURCE"
	;;
darwin[[0-8]].*) #(vi
	cf_xopen_source="-D_APPLE_C_SOURCE"
	;;
darwin*) #(vi
	cf_xopen_source="-D_DARWIN_C_SOURCE"
	;;
freebsd*|dragonfly*) #(vi
	# 5.x headers associate
	#	_XOPEN_SOURCE=600 with _POSIX_C_SOURCE=200112L
	#	_XOPEN_SOURCE=500 with _POSIX_C_SOURCE=199506L
	cf_POSIX_C_SOURCE=200112L
	cf_XOPEN_SOURCE=600
	cf_xopen_source="-D_BSD_TYPES -D__BSD_VISIBLE -D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE -D_XOPEN_SOURCE=$cf_XOPEN_SOURCE"
	;;
hpux11*) #(vi
	cf_xopen_source="-D_HPUX_SOURCE -D_XOPEN_SOURCE=500"
	;;
hpux*) #(vi
	cf_xopen_source="-D_HPUX_SOURCE"
	;;
irix[[56]].*) #(vi
	cf_xopen_source="-D_SGI_SOURCE"
	;;
linux*|gnu*|mint*|k*bsd*-gnu) #(vi
	CF_GNU_SOURCE
	;;
mirbsd*) #(vi
	# setting _XOPEN_SOURCE or _POSIX_SOURCE breaks <arpa/inet.h>
	;;
netbsd*) #(vi
	# setting _XOPEN_SOURCE breaks IPv6 for lynx on NetBSD 1.6, breaks xterm, is not needed for ncursesw
	;;
openbsd*) #(vi
	# setting _XOPEN_SOURCE breaks xterm on OpenBSD 2.8, is not needed for ncursesw
	;;
osf[[45]]*) #(vi
	cf_xopen_source="-D_OSF_SOURCE"
	;;
nto-qnx*) #(vi
	cf_xopen_source="-D_QNX_SOURCE"
	;;
sco*) #(vi
	# setting _XOPEN_SOURCE breaks Lynx on SCO Unix / OpenServer
	;;
solaris2.1[[0-9]]) #(vi
	cf_xopen_source="-D__EXTENSIONS__ -D_XOPEN_SOURCE=$cf_XOPEN_SOURCE"
	;;
solaris2.[[1-9]]) #(vi
	cf_xopen_source="-D__EXTENSIONS__"
	;;
*)
	AC_CACHE_CHECK(if we should define _XOPEN_SOURCE,cf_cv_xopen_source,[
	AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_xopen_source=no],
	[cf_save="$CPPFLAGS"
	 CPPFLAGS="$CPPFLAGS -D_XOPEN_SOURCE=$cf_XOPEN_SOURCE"
	 AC_TRY_COMPILE([#include <sys/types.h>],[
#ifdef _XOPEN_SOURCE
make an error
#endif],
	[cf_cv_xopen_source=no],
	[cf_cv_xopen_source=$cf_XOPEN_SOURCE])
	CPPFLAGS="$cf_save"
	])
])
	if test "$cf_cv_xopen_source" != no ; then
		CF_REMOVE_DEFINE(CFLAGS,$CFLAGS,_XOPEN_SOURCE)
		CF_REMOVE_DEFINE(CPPFLAGS,$CPPFLAGS,_XOPEN_SOURCE)
		cf_temp_xopen_source="-D_XOPEN_SOURCE=$cf_cv_xopen_source"
		CF_ADD_CFLAGS($cf_temp_xopen_source)
	fi
	CF_POSIX_C_SOURCE($cf_POSIX_C_SOURCE)
	;;
esac

if test -n "$cf_xopen_source" ; then
	CF_ADD_CFLAGS($cf_xopen_source)
fi
])