elinks/configure.in

dnl Process this file with autoconf to produce a configure script.

dnl There are two types of comments in this file.
dnl Comments that refer to Autoconf macros begin with "dnl", and m4
dnl discards them.  Other comments begin with "#", and they get copied
dnl to the configure script, hopefully making it easier to read.

dnl Autoconf 2.13 generates an incomplete config.h.in; see ELinks bug 936.
dnl Autoconf 2.59 is installed in the computer that generates our nightly
dnl snapshots, so we need to be compatible with that.
AC_PREREQ(2.59)
AC_INIT
AC_CONFIG_SRCDIR([src/main/main.c])
AC_CONFIG_AUX_DIR(config)

PACKAGE=elinks
VERSION=0.12.GIT
AC_SUBST(PACKAGE)
AC_SUBST(VERSION)
AC_DEFINE_UNQUOTED(PACKAGE, "$PACKAGE", [Package version])
AC_DEFINE_UNQUOTED(VERSION, "$VERSION", [Package version])
AC_CONFIG_HEADERS(config.h)

AC_CHECK_PROG(ACLOCAL,[aclocal],[aclocal],[config/missing aclocal])
AC_CHECK_PROG(AUTOCONF,[autoconf],[autoconf],[config/missing autoconf])
AC_CHECK_PROG(AUTOHEADER,[autoheader],[autoheader],[config/missing autoheader])

MAKE=

for make in gnumake gmake make false; do
	if test "x$MAKE" = x; then
		AC_PATH_PROGS(MAKE, "$make")
	fi
done

builddir="`pwd`"

# Cleanup if we are configuring with a previous build in the tree
if test -e Makefile.config; then
	AC_MSG_CHECKING([for previous build to clean])
	"$MAKE" -C "$builddir/src" cleanall >/dev/null 2>/dev/null
	AC_MSG_RESULT(done)
fi

# ===================================================================
# Load feature configuration file and start logging features.
# ===================================================================

features="features.conf"
AC_CHECK_FILE("$srcdir/$features", [ . $srcdir/$features ])
AC_CHECK_FILE("$builddir/$features", [ . $builddir/$features ])
echo "Feature summary:" > features.log

# ===================================================================
# Checks for programs.
# ===================================================================

AC_PROG_CC
AC_PROG_AWK
AC_PATH_PROGS(AWK, "$AWK")
AC_PROG_RANLIB
AC_PROG_INSTALL

AC_PATH_PROGS(GIT, "git")
AC_PATH_PROGS(SPARSE, "sparse")

CONFIG_ASCIIDOC="no"
CONFIG_POD2HTML="no"
CONFIG_XMLTO="no"
CONFIG_JW="no"

if test "x$CONFIG_DOC" != xno; then
	AC_PATH_PROGS(ASCIIDOC, "asciidoc")
	if test "x$ASCIIDOC" != "x"; then
		EL_CONFIG(CONFIG_ASCIIDOC, [AsciiDoc])
		EL_CONFIG(MANUAL_ASCIIDOC, [HTML (one file)])
		EL_CONFIG(MAN_ASCIIDOC, [HTML])

		echo > config.asciidoc-unsafe.txt
		if "$ASCIIDOC" --unsafe config.asciidoc-unsafe.txt >/dev/null 2>/dev/null; then
			ASCIIDOC_FLAGS=--unsafe
		fi
		rm config.asciidoc-unsafe.*
	fi

	AC_PATH_PROGS(XMLTO, "xmlto")
      	if test "x$XMLTO" != "x"; then
		EL_CONFIG(CONFIG_XMLTO, [XmlTo])
		EL_CONFIG(MANUAL_XMLTO, [HTML (multiple files)])
		EL_CONFIG(MAN_XMLTO, [man (groff)])
	fi

	AC_PATH_PROGS(JW, "jw")
      	if test "x$JW" != "x"; then
		EL_CONFIG(CONFIG_JW, [JadeWrapper])
		EL_CONFIG(MANUAL_JW, [PDF])
	fi

	AC_PATH_PROGS(POD2HTML, "pod2html")
      	if test "x$POD2HTML" != "x"; then
		EL_CONFIG(CONFIG_POD2HTML, [Pod2HTML])
	fi

	AC_PATH_PROGS(DOXYGEN, "doxygen")
	if test "x$DOXYGEN" != "x"; then
		EL_CONFIG(CONFIG_DOXYGEN, [Doxygen])
		api_srcdir="$(cd "$srcdir" && pwd)/src"
		AC_SUBST(api_srcdir)
	fi
fi

AC_SUBST(ASCIIDOC_FLAGS)
AC_SUBST(CONFIG_ASCIIDOC)
AC_SUBST(CONFIG_DOXYGEN)
AC_SUBST(CONFIG_POD2HTML)
AC_SUBST(CONFIG_XMLTO)
AC_SUBST(CONFIG_JW)

EL_CONFIG_DEPENDS(CONFIG_DOC, [CONFIG_ASCIIDOC CONFIG_XMLTO CONFIG_JW CONFIG_POD2HTML], [Documentation Tools])
EL_CONFIG_DEPENDS(CONFIG_MANUAL, [MANUAL_ASCIIDOC MANUAL_XMLTO MANUAL_JW], [Manual Formats])
EL_CONFIG_DEPENDS(CONFIG_MANPAGE, [MAN_ASCIIDOC MAN_XMLTO], [Man Page Formats])
EL_CONFIG_DEPENDS(CONFIG_APIDOCS, [CONFIG_DOXYGEN], [API Documentation])

# gcc specific options (to be continued at the bottom of configure)
if test "x$ac_cv_c_compiler_gnu" = "xyes"; then
  # We want to see all warnings and live with none.
  # We can't set up -Werror here as there may be some warnings in test
  # suite of configure, and we don't want to fail them.
  CFLAGS="$CFLAGS -Wall"
fi

# ===================================================================
# Checks for special OSes.
# ===================================================================

dnl EL_CHECK_COMPILER_MACRO(define, name, flagname)
AC_DEFUN([EL_CHECK_COMPILER_MACROS],
[
	AC_MSG_CHECKING([for $2])

	for flag in $3; do
		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[#ifndef $flag
kill me!
#endif ]])],[$1=yes],[$1=no])
		if test "[$]$1" = yes; then
			EL_CONFIG([$1], [$2])
			break
		fi
	done

	AC_MSG_RESULT([$]$1)
])

EL_CHECK_COMPILER_MACROS(CONFIG_OS_BEOS, [BEOS], [__BEOS__])
AC_SUBST(CONFIG_OS_BEOS)

EL_CHECK_COMPILER_MACROS(CONFIG_OS_RISCOS, [RISCOS], [__riscos__])
AC_SUBST(CONFIG_OS_RISCOS)

EL_CHECK_COMPILER_MACROS(CONFIG_OS_WIN32, [WIN32], [_WIN32 __WIN32__])
AC_SUBST(CONFIG_OS_WIN32)

EL_CHECK_COMPILER_MACROS(CONFIG_OS_OS2, [EMX], [__EMX__])
AC_SUBST(CONFIG_OS_OS2)
test "$CONFIG_OS_OS2" = yes && LDFLAGS=`echo "$LDFLAGS" | sed "s/-Zexe//g"`

AC_MSG_CHECKING([for UNIX])
dnl FIXME: some depend kind of mechanism
if test "$CONFIG_OS_BEOS" = no && \
   test "$CONFIG_OS_RISCOS" = no && \
   test "$CONFIG_OS_WIN32" = no && \
   test "$CONFIG_OS_OS2" = no; then
	EL_CONFIG(CONFIG_OS_UNIX, [UNIX])
else
	CONFIG_OS_UNIX=no
fi
AC_MSG_RESULT($CONFIG_OS_UNIX)
AC_SUBST(CONFIG_OS_UNIX)

# ===================================================================
# Checks for header files.
# ===================================================================

AC_HEADER_DIRENT
AC_HEADER_STDC
AC_HEADER_SYS_WAIT
AC_HEADER_TIME

AC_CHECK_HEADERS(wctype.h)
AC_CHECK_HEADERS(fcntl.h limits.h time.h unistd.h)
AC_CHECK_HEADERS(sigaction.h)
AC_CHECK_HEADERS(arpa/inet.h)
AC_CHECK_HEADERS(netinet/in_systm.h netinet/in_system.h netinet/ip.h)
AC_CHECK_HEADERS(net/if.h netdb.h netinet/in.h netinet/in6_var.h)
AC_CHECK_HEADERS(ifaddrs.h)
AC_CHECK_HEADERS(sys/cygwin.h io.h)
AC_CHECK_HEADERS(sys/fmutex.h)
AC_CHECK_HEADERS(sys/ioctl.h sys/sockio.h)
AC_CHECK_HEADERS(sys/resource.h)
AC_CHECK_HEADERS(sys/select.h)
AC_CHECK_HEADERS(sys/signal.h)
AC_CHECK_HEADERS(sys/socket.h)
AC_CHECK_HEADERS(sys/time.h)
AC_CHECK_HEADERS(sys/utsname.h)
AC_CHECK_HEADERS(stdint.h inttypes.h)
AC_CHECK_HEADERS(locale.h pwd.h)
AC_CHECK_HEADERS(termios.h)


AC_CHECK_HEADERS(sys/un.h,
	[CONFIG_INTERLINK=yes
	 EL_CONFIG([CONFIG_INTERLINK], [interlinking])],
	[CONFIG_INTERLINK=no])
AC_SUBST(CONFIG_INTERLINK)

# ===================================================================
# Checks for typedefs, structures, and compiler characteristics.
# ===================================================================

AC_STRUCT_TM
AC_C_CONST
AC_C_INLINE
EL_CHECK_CODE(typeof, HAVE_TYPEOF, [], [int a; typeof(a) b;])

AC_SYS_LARGEFILE
AC_TYPE_SIZE_T
AC_TYPE_OFF_T
EL_CHECK_TYPE(ssize_t, int)
EL_CHECK_SYS_TYPE(long long, HAVE_LONG_LONG, [])
EL_CHECK_SYS_TYPE(off_t, HAVE_OFF_T, [])
EL_CHECK_INT_TYPE(int32_t, HAVE_INT32_T)
EL_CHECK_INT_TYPE(uint32_t, HAVE_UINT32_T)
EL_CHECK_INT_TYPE(uint16_t, HAVE_UINT16_T)

AC_CHECK_SIZEOF(char, 1)
AC_CHECK_SIZEOF(short, 2)
AC_CHECK_SIZEOF(int, 4)
AC_CHECK_SIZEOF(long, 4)
test "x$HAVE_LONG_LONG" = xyes && AC_CHECK_SIZEOF(long long, 8)
test "x$HAVE_OFF_T" = xyes && AC_CHECK_SIZEOF(off_t, 4)

# Check for variadic macros
EL_CHECK_CODE([variadic macros], HAVE_VARIADIC_MACROS,
		[#include <stdio.h>
		 #define a(b,c...) printf(b,##c)],
                [a("foo");a("%s","bar");a("%s%s","baz","quux");])

# Check for -rdynamic
#
# gcc -rdynamic calls ld -export-dynamic, which adds all symbols of
# the executable to its dynamic symbol table.  ELinks uses this for
# two purposes:
#
# 1. If ELinks detects a bug, it can try to display a backtrace by
#    calling backtrace_symbols_fd() in the GNU libc.  The glibc-2.3.6
#    manual states users of GNU ld must pass -rdynamic to make the
#    symbols available to the program.
#
# 2. It would eventually be nice to dynamically load shared
#    libraries as plugins (bug 73).  The plugins must be able to
#    call ELinks functions.  This can be implemented either by
#    registering all callable functions in ELinks-specific data
#    structures, or by letting the dynamic linker handle them.
#    The latter way requires something equivalent to -rdynamic.
#
# Because backtraces are not needed for correct operation, and bug
# 73 is not yet being fixed, the configure script and makefiles
# should not complain to the user if they find that -rdynamic does
# not work.  Besides, it was reported at elinks-users on 2006-09-12
# that gcc-3.4.2 with "ld: Software Generation Utilities - Solaris
# Link Editors: 5.8-1.284" on Sun Solaris 8 Sparc does not support
# -rdynamic but does something equivalent automatically.  (This was
# tested with "nm -D elinks | grep redraw_from_window".)
#
# FIXME: This check doesn't work. Something to do with the compiler
# happily ignoring it and stderr not being checked for error messages.
AC_MSG_CHECKING([for -rdynamic])
LDFLAGS_X="$LDFLAGS"
LDFLAGS="$LDFLAGS -rdynamic"
AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[have_rdynamic=yes],[have_rdynamic=no])
test "$have_rdynamic" = no && LDFLAGS="$LDFLAGS_X"
AC_MSG_RESULT($have_rdynamic)

# ===================================================================
# Check for POSIX <regex.h>
# ===================================================================

EL_CHECK_SYS_TYPE(regex_t, HAVE_REGEX_H, [#include <regex.h>])

# ===================================================================
# Checks for library functions.
# ===================================================================

AC_PROG_GCC_TRADITIONAL
AC_FUNC_MEMCMP
AC_FUNC_MMAP
AC_FUNC_STRFTIME
AC_CHECK_FUNCS(atoll gethostbyaddr herror strerror)
AC_CHECK_FUNCS(popen uname access chmod alarm timegm mremap)
AC_CHECK_FUNCS(strcasecmp strncasecmp strcasestr strstr strchr strrchr)
AC_CHECK_FUNCS(memmove bcopy stpcpy strdup index isdigit mempcpy memrchr)
AC_CHECK_FUNCS(snprintf vsnprintf asprintf vasprintf)
AC_CHECK_FUNCS(getifaddrs getpwnam inet_pton inet_ntop)
AC_CHECK_FUNCS(fflush fsync fseeko ftello sigaction)
AC_CHECK_FUNCS(gettimeofday clock_gettime)

AC_CHECK_FUNCS([cygwin_conv_to_full_win32_path])

AC_CHECK_FUNCS(setenv putenv, HAVE_SETENV_OR_PUTENV=yes)
AC_CHECK_FUNCS(getuid, HAVE_GETUID=yes)
AC_CHECK_FUNCS(geteuid, HAVE_GETEUID=yes)

# These aren't probably needed now, as they are commented in links.h.
# I've no idea about their historical background, but I keep them here
# just in the case they will help later. --pasky
AC_CHECK_FUNCS(getpid, HAVE_GETPID=yes)
AC_CHECK_FUNCS(setpgid getpgid setpgrp getpgrp)
AC_CHECK_FUNCS(raise, HAVE_RAISE=yes)
AC_CHECK_FUNCS(kill, HAVE_KILL=yes)

if test x"$HAVE_RAISE" = x; then
	if test x"$HAVE_KILL" = x || test x"$HAVE_GETPID" = x; then
		AC_MSG_ERROR([Unable to emulate raise()])
	fi
fi

AC_CACHE_CHECK([for __va_copy],el_cv_HAVE_VA_COPY,[
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdarg.h>
va_list ap1,ap2;]], [[__va_copy(ap1,ap2);]])],[el_cv_HAVE_VA_COPY=yes],[el_cv_HAVE_VA_COPY=no])])
if test x"$el_cv_HAVE_VA_COPY" = x"yes"; then
	EL_DEFINE(HAVE_VA_COPY, __va_copy)
fi

AC_CACHE_CHECK([for sysconf(_SC_PAGE_SIZE)],el_cv_HAVE_SC_PAGE_SIZE,[
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>
]], [[int page_size = sysconf(_SC_PAGE_SIZE);]])],[el_cv_HAVE_SC_PAGE_SIZE=yes],[el_cv_HAVE_SC_PAGE_SIZE=no])])
if test x"$el_cv_HAVE_SC_PAGE_SIZE" = x"yes"; then
	EL_DEFINE(HAVE_SC_PAGE_SIZE, _SC_PAGE_SIZE)
fi

AC_CACHE_CHECK([for C99 vsnprintf],el_cv_HAVE_C99_VSNPRINTF,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

char buf[8];

int bar(char *buf, const char *format, va_list ap)
{
       return vsnprintf(buf, 0, format, ap);
}

void foo(const char *format, ...) {
       va_list ap;
       int len;

       va_start(ap, format);
       len = bar(buf, format, ap);
       va_end(ap);
       if ((len != 6) && (len != 7)) exit(1); /* \n -> \r\n */

       va_start(ap, format);
       len = bar(buf, format, ap);
       va_end(ap);
       if ((len != 6) && (len != 7)) exit(1);

       if (snprintf(buf, 3, "hello") != 5 || strcmp(buf, "he") != 0) exit(1);

       exit(0);
}
main() { foo("hello\n"); }
]])],[el_cv_HAVE_C99_VSNPRINTF=yes],[el_cv_HAVE_C99_VSNPRINTF=no],[el_cv_HAVE_C99_VSNPRINTF=cross])])
if test x"$el_cv_HAVE_C99_VSNPRINTF" = x"yes"; then
	EL_DEFINE(HAVE_C99_VSNPRINTF, [C99 compliant vsnprintf()])
fi

# OpenSSL and Lua frequently need dlopen
AC_CHECK_LIB(dl, dlopen)

# ===================================================================
# Checks for libraries.
# ===================================================================

AC_CHECK_FUNC(socket, cf_result=yes, cf_result=no)
if test "$cf_result" = no; then
	AC_CHECK_LIB(socket, socket)
fi

AC_CHECK_FUNC(setsockopt, cf_result=yes, cf_result=no)
if test "$cf_result" = no; then
	AC_CHECK_LIB(socket, setsockopt)
fi

AC_CHECK_FUNC(gethostbyname, cf_result=yes, cf_result=no)
if test "$cf_result" = no; then
	AC_CHECK_LIB(socket, gethostbyname, cf_result=yes, cf_result=no)
	if test "$cf_result" = no; then
		AC_CHECK_LIB(nsl, gethostbyname)
	else
		test -z "`echo $LIBS | grep -- -lsocket`" && LIBS="$LIBS -lsocket"
	fi
fi

# ===================================================================
# Checks for packaging specific options.
# ===================================================================

AC_ARG_WITH(xterm, [  --with-xterm            how to invoke the X terminal emulator],
            [ if test "$withval" != no && test "$withval" != yes; then
		AC_DEFINE_UNQUOTED(XTERM, "$withval", [How to invoke XTerm])
	      fi ])

# ===================================================================
# Checks for a libraries, optional even if installed.
# ===================================================================

dnl EL_CHECK_OPTIONAL_LIBRARY(define, name, header, lib, function)
AC_DEFUN([EL_CHECK_OPTIONAL_LIBRARY],
[
	AC_MSG_CHECKING([for $2 support])

	if test "[$]$1" != no; then
		AC_MSG_RESULT(yes)
		EL_SAVE_FLAGS
		if test -n "$withval" && test -d "$withval"; then
			# Be a little more careful when setting
			# include and lib directories. This way
			# $withval will work when includes are
			# there but the library is in the common
			# /usr/lib ... Does the right thing when
			# looking for gc on Debian.
			if test -d "$withval/include"; then
				CFLAGS="$CFLAGS -I$withval/include"
				CPPFLAGS="$CPPFLAGS -I$withval/include"
			else
				CFLAGS="$CFLAGS -I$withval"
				CPPFLAGS="$CPPFLAGS -I$withval"
			fi
			if test -d "$withval/lib"; then
				LDFLAGS="$LDFLAGS -L$withval/lib"
			fi
		fi

		AC_CHECK_HEADERS([$3], [$1=yes], [$1=no; break;])
		if test "[$]$1" = yes; then
			AC_CHECK_LIB([$4], [$5], [$1=yes], [$1=no])
		fi

		if test "[$]$1" = yes; then
			EL_CONFIG([$1], [$2])
			LIBS="$LIBS -l$4"
		else
			if test -n "[$]WITHVAL_$1" &&
			   test "[$]WITHVAL_$1" != xno; then
				AC_MSG_ERROR([$2 not found])
			fi
			EL_RESTORE_FLAGS
		fi
	else
		AC_MSG_RESULT(disabled)
	fi
])

dnl EL_CONFIG_OPTIONAL_LIBRARY(define, name, header, lib, function, confhelp)
AC_DEFUN([EL_CONFIG_OPTIONAL_LIBRARY],
[
	$1=yes
	WITHVAL_$1=

	AC_ARG_WITH([$2], [$6], [WITHVAL_$1="[$]withval"])
	if test "x[$]WITHVAL_$1" = xno; then $1=no; fi

	EL_CHECK_OPTIONAL_LIBRARY([$1], [$2], [$3], [$4], [$5])

	EL_LOG_CONFIG([$1], [$2], [])
])

EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_GPM, gpm, gpm.h, gpm, Gpm_Open,
	[  --without-gpm           disable gpm (mouse) support])

# ELinks calls deflateInit2 with windowBits = MAX_WBITS | 32, to
# enable automatic decoding of both zlib and gzip headers.  This
# feature was added in zlib 1.2.0.2; earlier versions return an error.
# The gzclearerr function was also added in zlib 1.2.0.2, so check for
# that, even though ELinks does not actually call gzclearerr.
EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_GZIP, zlib, zlib.h, z, gzclearerr,
	[  --without-zlib          disable zlib support])

EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_BZIP2, bzlib, bzlib.h, bz2, BZ2_bzReadOpen,
	[  --without-bzlib         disable bzlib support])

EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_IDN, idn, idna.h, idn, stringprep_check_version,
	[  --without-idn           disable international domain names support])

if test "x{with_gc}" != xno; then
	EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_GC, gc, gc.h, gc, GC_init,
		[  --with-gc               enable Boehm's garbage collector])
fi

EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_LZMA, lzma, lzma.h, lzma, lzma_code,
	[  --without-lzma          disable lzma encoding support])

# ===================================================================
# Check for GSSAPI, optional even if installed.
# ===================================================================

enable_gssapi="no";

AC_ARG_WITH(gssapi, [  --with-gssapi           enable GSSAPI support],
            [ if test "x$withval" != xno; then enable_gssapi=yes; fi ])

AC_MSG_CHECKING([for GSSAPI])

if test "$enable_gssapi" = "yes"; then
	AC_MSG_RESULT(yes)
	GSSAPI_CFLAGS=`krb5-config --cflags gssapi`
	GSSAPI_LIBS=`krb5-config --libs gssapi`
	CFLAGS="$GSSAPI_CFLAGS $CFLAGS"
	LIBS="$GSSAPI_LIBS $LIBS"
 	EL_CONFIG(CONFIG_GSSAPI, [GssApi])
else
	AC_MSG_RESULT(no)
fi

AC_SUBST(CONFIG_GSSAPI)

# ===================================================================
# Bookmark and XBEL support
# ===================================================================

EL_SAVE_FLAGS

EL_ARG_ENABLE(CONFIG_BOOKMARKS, bookmarks, [Bookmarks],
	      [  --disable-bookmarks     disable bookmark support])

# Check whether --enable-xbel or --disable-xbel was given.
if test "x${enable_xbel}" != xno; then
	AC_CHECK_HEADERS(expat.h, HAVE_LIBEXPAT=yes, HAVE_LIBEXPAT=no)

	if test "$HAVE_LIBEXPAT" = yes; then
		AC_CHECK_LIB(expat, XML_ParserCreate, HAVE_LIBEXPAT=yes, HAVE_LIBEXPAT=no)
		if test "$HAVE_LIBEXPAT" = yes; then
			LIBS="$LIBS -lexpat"
		fi
	fi
fi


EL_ARG_DEPEND(CONFIG_XBEL_BOOKMARKS, xbel, [CONFIG_BOOKMARKS:yes HAVE_LIBEXPAT:yes],
	      [XBEL bookmarks],
	      [  --disable-xbel          disable XBEL bookmark support (requires expat)])

if test "$CONFIG_XBEL_BOOKMARKS" != yes; then
	EL_RESTORE_FLAGS
fi

# ===================================================================
# Checks for BSD sysmouse
# ===================================================================

HAVE_SYSMOUSE_HEADER="no"

# Either of these header files provides the (same) sysmouse interface
AC_CHECK_HEADERS(sys/consio.h machine/console.h, [HAVE_SYSMOUSE_HEADER="yes"])

# ===================================================================
# Checks for OS/2
# ===================================================================

if test "$CONFIG_OS_OS2" = yes; then
	EL_CONFIG_OS_OS2
fi

# ===================================================================
# Checks for Win32
# ===================================================================

if test "$CONFIG_OS_WIN32" = yes; then
	EL_CONFIG_OS_WIN32
fi

# ===================================================================
# Check for SEE (Simple Ecmascript Engine)
# ===================================================================
AC_ARG_WITH(see, [  --with-see              enable Simple Ecmascript Engine (SEE) support],
            [ if test "x$withval" != xno; then enable_see=yes; fi ])

# The following is probably bad, ugly and so on. Stolen from Guile's (1.4)
# SEE_FLAGS but I really don't want to require people to have Guile in order
# to compile CVS. Also, the macro seems to be really stupid regarding searching
# for Guile in $PATH etc. --pasky

CONFIG_ECMASCRIPT_SEE=no

if test "$enable_see" = "yes"; then
	if test -d "$withval"; then
		SEE_PATH="$withval:$PATH"
	else
		SEE_PATH="$PATH"
	fi

	AC_PATH_PROG(SEE_CONFIG, libsee-config, no, $SEE_PATH)
	AC_MSG_CHECKING([for SEE (2.0.1131 or later)])
	if test "$SEE_CONFIG" != no; then
		EL_SAVE_FLAGS
		SEE_LIBS="`$SEE_CONFIG --libs`"
		SEE_CFLAGS="`$SEE_CONFIG --cppflags`"
		CPPFLAGS="$SEE_CFLAGS $CPPFLAGS"
		LIBS="$SEE_LIBS $LIBS_X"
		AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <see/see.h>]], [[#if SEE_VERSION_API_MAJOR < 2
			#error SEE too old
			#endif
		]])],[cf_result=yes],[cf_result=no])
		EL_RESTORE_FLAGS
		if test "$cf_result" = yes; then
			LIBS="$SEE_LIBS $LIBS"
			EL_CONFIG(CONFIG_ECMASCRIPT_SEE, [SEE])
			AC_SUBST(SEE_CFLAGS)
		fi
		AC_MSG_RESULT($cf_result)
	else
		if test -n "$withval" && test "x$withval" != xno; then
			AC_MSG_ERROR([SEE not found])
		else
			AC_MSG_WARN([SEE support disabled])
		fi
	fi
fi

# ===================================================================
# Check for SpiderMonkey, optional even if installed.
# ===================================================================

AC_ARG_WITH(spidermonkey, [  --without-spidermonkey  disable SpiderMonkey Mozilla JavaScript engine support],
            [if test "$withval" = no; then disable_spidermonkey=yes; fi])
AC_MSG_CHECKING([for SpiderMonkey (1.5 RC3a or later)])

EL_SAVE_FLAGS
cf_result=no

if test -z "$disable_spidermonkey"; then
	if test ! -d "$withval"; then
		withval="";
	fi
	for spidermonkeydir in "$withval" "" /usr /usr/local /opt/spidermonkey /opt/js; do
		for spidermonkeyinclude in "/include" "/include/js" "/include/smjs" "/include/mozjs"; do
			for spidermonkeylib in js smjs mozjs; do
				if test "$cf_result" = no &&
				   test -f "$spidermonkeydir$spidermonkeyinclude/jsapi.h"; then
					SPIDERMONKEY_LIBS="-L$spidermonkeydir/lib -l$spidermonkeylib"
					SPIDERMONKEY_CFLAGS="-I$spidermonkeydir$spidermonkeyinclude"

					LIBS="$SPIDERMONKEY_LIBS $LIBS_X"
					CFLAGS="$CFLAGS_X $SPIDERMONKEY_CFLAGS"
					CPPFLAGS="$CPPFLAGS_X $SPIDERMONKEY_CFLAGS"

					AC_LINK_IFELSE([AC_LANG_PROGRAM([[#define XP_UNIX
						     #include <jsapi.h>]], [[JS_GetReservedSlot(NULL, NULL, 0, NULL)]])],[cf_result=yes],[cf_result=no])
				fi
			done
		done
	done
fi

AC_MSG_RESULT($cf_result)
CONFIG_SPIDERMONKEY="$cf_result"
EL_RESTORE_FLAGS

if test "x$CONFIG_SPIDERMONKEY" = xyes &&
   test "x$CONFIG_ECMASCRIPT_SEE" != xyes; then
	EL_CONFIG(CONFIG_ECMASCRIPT_SMJS, [SpiderMonkey document scripting])
else
	CONFIG_ECMASCRIPT_SMJS=no
fi

EL_CONFIG_DEPENDS(CONFIG_ECMASCRIPT, [CONFIG_ECMASCRIPT_SEE CONFIG_ECMASCRIPT_SMJS], [ECMAScript (JavaScript)])
AC_SUBST(CONFIG_ECMASCRIPT_SEE)
AC_SUBST(CONFIG_ECMASCRIPT_SMJS)


# ===================================================================
# Optional Spidermonkey-based ECMAScript browser scripting
# ===================================================================

AC_ARG_ENABLE(sm-scripting,
	      [  --disable-sm-scripting  ECMAScript browser scripting (requires Spidermonkey)],
	      [if test "$enableval" != no; then enableval="yes"; fi
	       CONFIG_SCRIPTING_SPIDERMONKEY="$enableval";])

if test "x$CONFIG_SPIDERMONKEY" = xyes &&
   test "x$CONFIG_SCRIPTING_SPIDERMONKEY" = xyes; then
	EL_CONFIG(CONFIG_SCRIPTING_SPIDERMONKEY, [SpiderMonkey])
else
	CONFIG_SCRIPTING_SPIDERMONKEY=no
fi

if test "x$CONFIG_ECMASCRIPT_SMJS" = xyes ||
   test "x$CONFIG_SCRIPTING_SPIDERMONKEY" = xyes; then
	LIBS="$LIBS $SPIDERMONKEY_LIBS"
	AC_SUBST(SPIDERMONKEY_LIBS)
	AC_SUBST(SPIDERMONKEY_CFLAGS)
	AC_SUBST(CONFIG_SPIDERMONKEY)
fi

# ===================================================================
# Check for Guile, optional even if installed.
# ===================================================================

enable_guile="no";

AC_ARG_WITH(guile, [  --with-guile            enable Guile support],
            [ if test "x$withval" != xno; then enable_guile=yes; fi ])

# The following is probably bad, ugly and so on. Stolen from Guile's (1.4)
# GUILE_FLAGS but I really don't want to require people to have Guile in order
# to compile CVS. Also, the macro seems to be really stupid regarding searching
# for Guile in $PATH etc. --pasky

AC_MSG_CHECKING([for Guile])

if test "$enable_guile" = "yes"; then
	AC_MSG_RESULT(yes);
	## Based on the GUILE_FLAGS macro.

	if test -d "$withval"; then
		GUILE_PATH="$withval:$PATH"
	else
		GUILE_PATH="$PATH"
	fi

	AC_PATH_PROG(GUILE_CONFIG, guile-config, no, $GUILE_PATH)

	## First, let's just see if we can find Guile at all.
	if test "$GUILE_CONFIG" != no; then
		cf_result="yes";

		GUILE_LIBS="`guile-config link`"
		GUILE_CFLAGS="`guile-config compile`"
		LIBS="$GUILE_LIBS $LIBS"
		EL_CONFIG(CONFIG_SCRIPTING_GUILE, [Guile])
		AC_SUBST(GUILE_CFLAGS)
		cat <<EOF
***********************************************************************
The Guile support is incomplete and not so well integrated to ELinks
yet. That means, e.g., that you have no Guile console and there might
not be all the necessary hooks. Also, the Guile interface is not too
well tested (success stories heartily welcomed!).  See
src/scripting/guile/README for further details and hints.
***********************************************************************
EOF
	else
		if test -n "$withval" && test "x$withval" != xno; then
			AC_MSG_ERROR([Guile not found])
		else
			AC_MSG_WARN([Guile support disabled])
		fi
	fi
else
	AC_MSG_RESULT(no);
fi

# ===================================================================
# Check for Perl
# ===================================================================
enable_perl="no";

AC_ARG_WITH(perl, [  --with-perl             enable Perl support],
            [
if test "$withval" = yes; then
	# FIXME: If withval is a valid directory append it to PATH
	# so that you can specify one of several perl installations.
	withval="";
	enable_perl=yes;
fi
	    ])

AC_MSG_CHECKING([for Perl])

cf_result=no

EL_SAVE_FLAGS

if test "$enable_perl" = "yes"; then
	PERL_LIBS="`perl -MExtUtils::Embed -e ldopts`"
	PERL_CFLAGS="`perl -MExtUtils::Embed -e ccopts`"
	LIBS="$PERL_LIBS $LIBS"
	CFLAGS="$PERL_CFLAGS $CFLAGS"
	CPPFLAGS="$CPPFLAGS $PERL_CFLAGS"
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#include <EXTERN.h>
#include <perl.h>
#include <perlapi.h>
]], [[PerlInterpreter *my_perl = perl_alloc();]])],[cf_result=yes],[cf_result=no])
fi

if test "$cf_result"; then AC_MSG_RESULT($cf_result); fi

AC_MSG_CHECKING([whether POPpx works without an n_a variable])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <EXTERN.h>
#include <perl.h>
extern PerlInterpreter *my_perl;
]], [[dSP; (void) POPpx;]])],[AC_MSG_RESULT([yes])
AC_DEFINE([CONFIG_PERL_POPPX_WITHOUT_N_A], [1],
		[Define if using Perl 5.8.8 or later, where the "POPpx" macro
no longer needs an "n_a" variable like it did in 5.8.7])],[AC_MSG_RESULT([no])])

if test "$cf_result" != "yes"; then
	EL_RESTORE_FLAGS
else
	EL_CONFIG(CONFIG_SCRIPTING_PERL, [Perl])

	CFLAGS="$CFLAGS_X"
	CPPFLAGS="$CPPFLAGS_X"
	AC_SUBST(PERL_LIBS)
	AC_SUBST(PERL_CFLAGS)
fi

# ===================================================================
# Check for Python
# ===================================================================
enable_python="no";

AC_ARG_WITH(python, [  --with-python=[DIR]     enable Python support],
            [ if test "x$withval" != xno; then enable_python=yes; fi ])

EL_SAVE_FLAGS
cf_result=no

AC_MSG_CHECKING([for Python])

if test "$enable_python" = "yes"; then
	AC_MSG_RESULT(yes);

	if test -d "$withval"; then
		PYTHON_PATH="$withval:$PATH"
	else
		PYTHON_PATH="$PATH"
	fi

	AC_PATH_PROG(PYTHON, python, no, $PYTHON_PATH)

	if test "$PYTHON" != no; then
		cf_result="yes";

		PYTHON_CFLAGS="`$PYTHON -c 'from distutils import sysconfig; print "-I%s -I%s" % (sysconfig.get_python_inc(), sysconfig.get_python_inc(plat_specific=True))'`"
		PYTHON_LIBS="`$PYTHON -c 'from distutils import sysconfig; var = sysconfig.get_config_var; print "%s %s %s -L%s -lpython%s" % (var("LINKFORSHARED"), var("LIBS"), var("SYSLIBS"), var("LIBPL"), var("VERSION"))'`"
		LIBS="$PYTHON_LIBS $LIBS"
		CPPFLAGS="$CPPFLAGS $PYTHON_CFLAGS"
		AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <Python.h>]], [[Py_Initialize();]])],[cf_result=yes],[cf_result=no])

		if test "$cf_result" != "yes"; then
			EL_RESTORE_FLAGS
		else
			EL_CONFIG(CONFIG_SCRIPTING_PYTHON, [Python])
			AC_SUBST(PYTHON_LIBS)
			AC_SUBST(PYTHON_CFLAGS)
			CPPFLAGS="$CPPFLAGS_X"
			cat <<EOF
***********************************************************************
The Python support is incomplete and not so well integrated to ELinks
yet. That means, e.g., that you have no Python console and there might
not be all the necessary hooks. Also, the Python interface is not too
well tested (success stories heartily welcomed!).
***********************************************************************
EOF
		fi
	else
		if test -n "$withval" && test "x$withval" != xno; then
			AC_MSG_ERROR([Python not found])
		else
			AC_MSG_WARN([Python support disabled])
		fi
	fi
else
	AC_MSG_RESULT(no);
fi


# ===================================================================
# Check for Lua, optional even if installed.
# ===================================================================

# Do this the long way, as FreeBSD reportedly needs -L<dir> for
# anything other than /usr/lib, and Lua is very often in /usr/local/lib.

AC_ARG_WITH(lua, [  --without-lua           disable Lua support],
            [if test "$withval" = no; then disable_lua=yes; fi])
AC_MSG_CHECKING([for Lua])

EL_SAVE_FLAGS
cf_result=no

if test -z "$disable_lua"; then
	if test ! -d "$withval"; then
		withval="";
	fi
	for luadir in "$withval" "" /usr /usr/local; do
		for suffix in "" 50; do
			if test "$cf_result" = no && ( test -f "$luadir/include/lua.h" || \
			   test -f "$luadir/include/lua$suffix/lua.h" ) ; then
				LUA_LIBS="-L$luadir/lib -llua$suffix -llualib$suffix -lm"
				LUA_CFLAGS="-I$luadir/include -I$luadir/include/lua$suffix"

				LIBS="$LUA_LIBS $LIBS_X"
				CFLAGS="$CFLAGS_X $LUA_CFLAGS"
				CPPFLAGS="$CPPFLAGS_X $LUA_CFLAGS"

				# Check that it is a compatible Lua version
				AC_LINK_IFELSE([AC_LANG_PROGRAM([[	#include <lua.h>
						#include <lualib.h>]], [[	lua_State *L = lua_open();
						luaopen_base(L);
						luaopen_table(L);
						luaopen_io(L);
						luaopen_string(L);
						luaopen_math(L);
						lua_pushboolean(L, 1);
						lua_close(L);]])],[cf_result=yes],[cf_result=no])
			fi
		done
	done
fi

AC_MSG_RESULT($cf_result)

if test "$cf_result" != yes; then
	EL_RESTORE_FLAGS
else
	EL_CONFIG(CONFIG_SCRIPTING_LUA, [Lua])
	AC_CHECK_HEADERS(lauxlib.h)

	CFLAGS="$CFLAGS_X"
	CPPFLAGS="$CPPFLAGS_X"
	AC_SUBST(LUA_LIBS)
	AC_SUBST(LUA_CFLAGS)
fi


# ===================================================================
# Check for Ruby, optional even if installed.
# ===================================================================

EL_CONFIG_SCRIPTING_RUBY

# ===================================================================
# Setup global scripting
# ===================================================================

EL_CONFIG_DEPENDS(CONFIG_SCRIPTING, [CONFIG_SCRIPTING_GUILE CONFIG_SCRIPTING_LUA CONFIG_SCRIPTING_PERL CONFIG_SCRIPTING_PYTHON CONFIG_SCRIPTING_RUBY CONFIG_SCRIPTING_SPIDERMONKEY], [Browser scripting])
AC_SUBST(CONFIG_SCRIPTING_GUILE)
AC_SUBST(CONFIG_SCRIPTING_LUA)
AC_SUBST(CONFIG_SCRIPTING_PERL)
AC_SUBST(CONFIG_SCRIPTING_PYTHON)
AC_SUBST(CONFIG_SCRIPTING_RUBY)
AC_SUBST(CONFIG_SCRIPTING_SPIDERMONKEY)
AC_SUBST(CONFIG_SCRIPTING)


# ===================================================================
# Check for SSL support.
# ===================================================================

# We by default use OpenSSL, and we always prefer it. However, when GNUTLS
# is enabled, we won't try to use OpenSSL anymore.

# For wiping SSL hooks..
#ifdef CONFIG_SSL

disable_openssl=""
disable_gnutls=""
enable_gnutls=""

AC_ARG_WITH(gnutls, [  --without-gnutls        disable GNUTLS SSL support],
	    [if test "$with_gnutls" = no;  then disable_gnutls=yes; fi])
AC_ARG_WITH(gnutls, [  --with-gnutls[=DIR]     enable GNUTLS SSL support],
	    [if test "$with_gnutls" != no;  then enable_gnutls=yes; fi])
gnutls_withval="$withval"

if test "$enable_gnutls" = yes; then
	disable_openssl=yes;
fi

AC_ARG_WITH(openssl, [  --without-openssl       disable OpenSSL support],
	    [if test "$with_openssl" = no;  then disable_openssl=yes; fi])
AC_ARG_WITH(openssl, [  --with-openssl[=DIR]    enable OpenSSL support (default)])
openssl_withval="$withval"

# ---- OpenSSL

AC_MSG_CHECKING([for OpenSSL])

EL_SAVE_FLAGS
cf_result="no"

if test "$disable_openssl" = yes; then
	cf_result="not used"
else
	for ssldir in "$openssl_withval" "" /usr /usr/local/openssl \
			 /usr/lib/openssl /usr/local/ssl \
			 /usr/local/www /usr/lib/ssl /usr/local \
			 /usr/pkg /opt /opt/openssl; do
		if test "$cf_result" = no; then
			if test -d "$ssldir"; then
				OPENSSL_CFLAGS="-I$ssldir/include"
				LIBS="-L$ssldir/lib -lssl -lcrypto $LIBS_X"
				CFLAGS="$CFLAGS_X $OPENSSL_CFLAGS"
				CPPFLAGS="$CPPFLAGS_X $OPENSSL_CFLAGS"
#				# FIXME: This created serious portability problems. --pasky
#				if test "$CC" == "gcc"; then
#					# I'm not sure about compatibility here. --pasky
#					LIBS="$LIBS -R$ssldir/lib"
#				fi
			else
				LIBS="-lssl -lcrypto $LIBS_X"
			fi
			AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <openssl/ssl.h>]], [[OpenSSL_add_all_algorithms()]])],[cf_result=yes],[cf_result=no])
			if test "$cf_result" != yes; then
				AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <openssl/ssl.h>]], [[SSLeay_add_ssl_algorithms()]])],[cf_result=yes],[cf_result=no])
			fi
		fi
	done

	if test "$cf_result" != yes; then
		if test -n "$openssl_withval" && test "x$openssl_withval" != xno; then
			AC_MSG_ERROR([OpenSSL not found])
		fi
		EL_RESTORE_FLAGS
	else
		EL_CONFIG(CONFIG_OPENSSL, [OpenSSL])

		CFLAGS="$CFLAGS_X"
		AC_SUBST(OPENSSL_CFLAGS)
	fi
fi

AC_MSG_RESULT($cf_result)

CONFIG_GNUTLS_OPENSSL_COMPAT=no
# ---- GNU TLS
dnl We can't have AC_MSG_CHECKING here, because AC_PATH_PROG prints its own and
dnl it looks ugly then.

if test "$cf_result" = yes; then
	cf_result="not used"

else
	EL_SAVE_FLAGS
	cf_result="no"

	if test -z "$disable_gnutls"; then
		# Sure, we maybe _could_ use their macro, but how to ensure
		# that the ./configure script won't fail if the macro won't be
		# found..? :( --pasky

		GNUTLS_PATH="$PATH:/usr/local/gnutls:/opt:/opt/gnutls"

		if test -d "$gnutls_withval"; then
			GNUTLS_PATH="$gnutls_withval:$GNUTLS_PATH"
		fi

		AC_PATH_PROG(LIBGNUTLS_CONFIG, libgnutls-config, no, $GNUTLS_PATH)

		if test "$LIBGNUTLS_CONFIG" = "no" ; then
			cf_result=no
		else
			GNUTLS_CFLAGS=`$LIBGNUTLS_CONFIG --cflags`
			GNUTLS_LIBS=`$LIBGNUTLS_CONFIG --libs`

			LIBS="$GNUTLS_LIBS $LIBS_X"
			CFLAGS="$CFLAGS_X $GNUTLS_CFLAGS"
			CPPFLAGS="$CPPFLAGS_X $GNUTLS_CFLAGS"

			# Verify if it's really usable.  gnutls_session was
			# renamed to gnutls_session_t before GNU TLS 1.2.0
			# (on 2004-06-13); ELinks now requires this.
			AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <gnutls/gnutls.h>]], [[gnutls_session_t dummy;
				     gnutls_check_version(NULL)]])],[cf_result=yes],[cf_result=no])
		fi

		if test "$cf_result" = yes; then
			EL_CONFIG(CONFIG_GNUTLS, [GNUTLS])

			CFLAGS="$CFLAGS_X"
			AC_SUBST(GNUTLS_CFLAGS)

			# Verify if the MD5 compatibility layer is usable.
			CONFIG_GNUTLS_OPENSSL_COMPAT=yes
			EL_CHECK_OPTIONAL_LIBRARY(CONFIG_GNUTLS_OPENSSL_COMPAT,
						  [GNU TLS OpenSSL compatibility],
						  gnutls/openssl.h, gnutls-openssl,
						  MD5_Init)
		else
			if test -n "$gnutls_withval" && test "x$gnutls_withval" != xno; then
				AC_MSG_ERROR([GNUTLS (1.2 or later) not found.  ELinks no longer supports GNUTLS 1.1.])
			fi
			EL_RESTORE_FLAGS
		fi
	fi
fi

AC_MSG_CHECKING([for GNU TLS (1.2 or later)])
AC_MSG_RESULT($cf_result)

# Final SSL setup

EL_CONFIG_DEPENDS(CONFIG_SSL, [CONFIG_OPENSSL CONFIG_GNUTLS], [SSL])
AC_SUBST(CONFIG_GNUTLS_OPENSSL_COMPAT)
AC_SUBST(CONFIG_OPENSSL)
AC_SUBST(CONFIG_GNUTLS)

#endif

AC_MSG_CHECKING([whether to be or not to be])
AC_MSG_RESULT([needs to be determined experimentally])

# ===================================================================
# Check for IPv6 support and related functions.
# ===================================================================

EL_CHECK_NET_TYPE(struct sockaddr_storage, HAVE_SA_STORAGE, [])
EL_CHECK_NET_TYPE(struct sockaddr_in6, HAVE_SA_IN6, [#include <netinet/in.h>])
EL_CHECK_NET_TYPE(struct addrinfo, HAVE_ADDRINFO, [#include <netdb.h>])

AC_CHECK_FUNC(getaddrinfo, HAVE_GETADDRINFO=yes, HAVE_GETADDRINFO=no)
if test "$HAVE_GETADDRINFO" != yes; then
	AC_CHECK_LIB(inet6, getaddrinfo, HAVE_GETADDRINFO=yes, HAVE_GETADDRINFO=no)
	if test "$HAVE_GETADDRINFO" = yes; then
		LIBS="$LIBS -linet6"
	fi
fi


# ===================================================================
# Checking for X11 (window title restoring).
# ===================================================================

AC_PATH_X
if test x"$no_x" != xyes; then
	EL_SAVE_FLAGS
	if test -n "$x_includes"; then
		X_CFLAGS="-I$x_includes"
		CPPFLAGS="$CPPLAGS $X_CFLAGS"
		CFLAGS="$CFLAGS $X_CFLAGS"
	fi
	if test -n "$x_libraries"; then
		LDFLAGS="$LDFLAGS -L$x_libraries"
	fi
	LIBS="-lX11 $LIBS"
	AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <X11/Xlib.h>]], [[XrmInitialize()]])],[cf_result=yes],[cf_result=no])
	EL_RESTORE_FLAGS
	if test "$cf_result" = yes; then
		if test -n "$x_libraries"; then
			LDFLAGS="$LDFLAGS -L$x_libraries"
		fi
		LIBS="-lX11 $LIBS"
		EL_DEFINE(HAVE_X11, [X11 for restoring window titles])
		AC_SUBST(X_CFLAGS)
	fi
fi


# ===================================================================
# Backtraces displaying support.
# ===================================================================

AC_CHECK_HEADERS(execinfo.h, HAVE_EXECINFO=yes, HAVE_EXECINFO=no)
# possible checks for other system-specific means go here


# ===================================================================
# Gettext grey zone. Beware.
# ===================================================================

ALL_LINGUAS="af be bg ca cs da de el es et fi fr gl hr hu id is it lt nl nb pl pt pt_BR ro ru sk sr sv tr uk"

AM_GNU_GETTEXT

dnl AC_MSG_CHECKING([how many characters your English alphabet has])
dnl # f33r d4 l33t... I hope it's portable. :)
dnl cf_result=$((48#z - 48#a + 1));
dnl AC_MSG_RESULT($cf_result)


# ===================================================================
# Compile-time features control
# ===================================================================

EL_ARG_ENABLE(CONFIG_COOKIES, cookies, [Cookies],
	      [  --disable-cookies       disable cookie support])

EL_ARG_ENABLE(CONFIG_FORMHIST, formhist, [Form history],
	      [  --disable-formhist      disable form history support])

EL_ARG_ENABLE(CONFIG_GLOBHIST, globhist, [Global history],
	      [  --disable-globhist      disable global history support])


EL_ARG_ENABLE(CONFIG_MAILCAP, mailcap, [Mailcap],
	      [  --disable-mailcap       disable mailcap support])

EL_ARG_ENABLE(CONFIG_MIMETYPES, mimetypes, [Mimetypes files],
	      [  --disable-mimetypes     disable mimetypes files support])


EL_ARG_DEPEND(CONFIG_IPV6, ipv6,
	      [HAVE_SA_STORAGE:yes HAVE_SA_IN6:yes HAVE_ADDRINFO:yes HAVE_GETADDRINFO:yes],
	      [IPv6],
	      [  --disable-ipv6          disable IPv6 support])

EL_ARG_ENABLE(CONFIG_BITTORRENT, bittorrent, [BitTorrent protocol],
	      [  --enable-bittorrent     enable BitTorrent protocol support])

EL_ARG_ENABLE(CONFIG_DATA, data, [Data protocol],
	      [  --disable-data          disable data protocol support])

EL_ARG_ENABLE(CONFIG_URI_REWRITE, uri-rewrite, [URI rewriting],
	      [  --disable-uri-rewrite   disable URI rewrite support])

EL_ARG_DEPEND(CONFIG_CGI, cgi, [HAVE_SETENV_OR_PUTENV:yes], [Local CGI],
	      [  --enable-cgi            enable local CGI support])

EL_ARG_ENABLE(CONFIG_FINGER, finger, [Finger protocol],
	      [  --enable-finger         enable finger protocol support])

# ===================================================================
# FSP protocol
# ===================================================================
EL_SAVE_FLAGS

if test "x${enable_fsp}" != xno; then
	AC_CHECK_HEADERS(fsplib.h, HAVE_FSPLIB=yes, HAVE_FSPLIB=no)

	if test "$HAVE_FSPLIB" = yes; then
		AC_CHECK_LIB(fsplib, fsp_open_session, HAVE_FSPLIB=yes, HAVE_FSPLIB=no)
		if test "$HAVE_FSPLIB" = yes; then
			LIBS="$LIBS -lfsplib"
		else
			AC_CHECK_LIB(fsp, fsp_open_session, HAVE_FSPLIB=yes, HAVE_FSPLIB=no)
			if test "$HAVE_FSPLIB" = yes; then
				LIBS="$LIBS -lfsp"
			fi
		fi
	fi
fi

EL_ARG_DEPEND(CONFIG_FSP, fsp, [HAVE_FSPLIB:yes], [FSP protocol],
	      [  --enable-fsp            enable FSP protocol support])

if test "x$CONFIG_FSP" = xno; then
	EL_RESTORE_FLAGS
fi

EL_ARG_ENABLE(CONFIG_FTP, ftp, [FTP protocol],
	      [  --disable-ftp           disable ftp protocol support])

EL_ARG_ENABLE(CONFIG_GOPHER, gopher, [Gopher protocol],
	      [  --enable-gopher         enable gopher protocol support])

EL_ARG_ENABLE(CONFIG_NNTP, nntp, [NNTP protocol],
	      [  --enable-nntp           enable nntp protocol support])

# ===================================================================
# SMB protocol support.
# ===================================================================
EL_SAVE_FLAGS

if test "x${enable_smb}" != xno; then
	AC_CHECK_HEADERS(libsmbclient.h, HAVE_SMBCLIENT=yes, HAVE_SMBCLIENT=no)

	if test "$HAVE_SMBCLIENT" = yes; then
		AC_CHECK_LIB(smbclient, smbc_init, HAVE_SMBCLIENT=yes, HAVE_SMBCLIENT=no)
		if test "$HAVE_SMBCLIENT" = yes; then
			LIBS="$LIBS -lsmbclient"
		fi
	fi
fi

EL_ARG_DEPEND(CONFIG_SMB, smb, [HAVE_SMBCLIENT:yes], [Samba protocol],
	      [  --enable-smb            enable Samba protocol support])

if test "x$CONFIG_SMB" = xno; then
	EL_RESTORE_FLAGS
fi


EL_ARG_ENABLE(CONFIG_MOUSE, mouse, [Mouse handling],
	      [  --disable-mouse         disable mouse support])

# GPM mouse is Linux specific, so ...
CONFIG_SYSMOUSE=yes
EL_ARG_DEPEND(CONFIG_SYSMOUSE, sysmouse,
	      [CONFIG_MOUSE:yes CONFIG_GPM:no HAVE_SYSMOUSE_HEADER:yes],
	      [BSD sysmouse],
	      [  --disable-sysmouse      disable BSD sysmouse support])

EL_ARG_ENABLE(CONFIG_88_COLORS, 88-colors, [88 colors],
	      [  --enable-88-colors      enable 88 color support])

EL_ARG_ENABLE(CONFIG_256_COLORS, 256-colors, [256 colors],
	      [  --enable-256-colors     enable 256 color support])

EL_ARG_ENABLE(CONFIG_TRUE_COLOR, true-color, [true color],
	      [  --enable-true-color     enable true color support])

EL_ARG_ENABLE(CONFIG_EXMODE, exmode, [Exmode interface],
	      [  --enable-exmode         enable exmode (CLI) interface])

EL_ARG_ENABLE(CONFIG_LEDS, leds, [LEDs],
	      [  --disable-leds          disable LEDs support])

EL_ARG_ENABLE(CONFIG_MARKS, marks, [Marks],
	      [  --disable-marks         disable document marks support])


EL_ARG_ENABLE(CONFIG_CSS, css, [Cascading Style Sheets],
	      [  --disable-css           disable Cascading Style Sheet support])

EL_ARG_DEPEND(CONFIG_HTML_HIGHLIGHT, html-highlight, [CONFIG_CSS:yes], [HTML highlighting],
	      [  --enable-html-highlight HTML highlighting using DOM engine])

# Everything in the tree already uses CONFIG_DOM
# so resolve CONFIG_HTML_HIGHLIGHT to CONFIG_DOM
EL_CONFIG_DEPENDS(CONFIG_DOM, [CONFIG_HTML_HIGHLIGHT], [DOM engine])

EL_ARG_DEPEND(CONFIG_BACKTRACE, backtrace, [HAVE_EXECINFO:yes], [Backtrace],
	      [  --disable-backtrace     disable backtrace support])

EL_ARG_DEPEND(CONFIG_NO_ROOT_EXEC, no-root, [HAVE_GETUID:yes HAVE_GETEUID:yes], [No root exec],
	      [  --enable-no-root        enable prevention of usage by root])


EL_ARG_ENABLE(CONFIG_DEBUG, debug, [Debug mode],
	      [  --enable-debug          enable leak debug and internal error checking])

EL_ARG_DEPEND(CONFIG_FASTMEM, fastmem, [CONFIG_DEBUG:no], [Fast mode],
              [  --enable-fastmem        enable direct use of system allocation functions, not usable with --enable-debug])

EL_ARG_ENABLE(CONFIG_OWN_LIBC, own-libc, [Own libc stubs],
              [  --enable-own-libc       force use of internal functions instead of those of system libc])

EL_ARG_ENABLE(CONFIG_SMALL, small, [Small binary],
	      [  --enable-small          reduce binary size as far as possible (but see the bottom of doc/small.txt!)])

EL_ARG_ENABLE(CONFIG_UTF8, utf-8, [UTF-8],
	      [  --disable-utf-8         disable UTF-8 support])


AC_ARG_ENABLE(weehoofooboomookerchoo,
              [
    Also check out the features.conf file for more information about features!
	      ],
	      [AC_MSG_ERROR(Are you strange, or what?)])


# == EMX hack

test "$CONFIG_OS_OS2" = yes && LDFLAGS="$LDFLAGS -Zexe"
test "$CONFIG_OS_OS2" = yes && LDFLAGS=`echo "$LDFLAGS" | sed "s/-Zbin-files//g"`


# ===================================================================
# Export directory paths
# ===================================================================

# Set up the ``entry points'' if they were not supplied by builder
test "x$prefix" = xNONE && prefix=$ac_default_prefix
test "x$exec_prefix" = xNONE && exec_prefix=${prefix}

# Create CONFDIR #define for config.h

# XXX: This may be dependent on a particular version of autoconf. Whatever,
# it's autoconf fault to force us to do such hacks ;p.
if test x"$sysconfdir" = x"\${prefix}/etc"; then
  # sysconfdir is set to its default value... fine, let's append /elinks/
  # XXX: We can't modify listing of the default in ./configure --help :-(
  sysconfdir_n=`eval echo "$sysconfdir"`
  sysconfdir=$sysconfdir_n
  (echo "$sysconfdir" | grep elinks >/dev/null 2>/dev/null) || \
	sysconfdir="$sysconfdir/elinks"
fi

CONFDIR=$sysconfdir
AC_DEFINE_UNQUOTED(CONFDIR, "$CONFDIR", [Directory containing default config])
AC_SUBST(CONFDIR)

# Create LOCALEDIR #define for config.h
LOCALEDIR=`eval echo "$datadir/locale"`
while echo "$LOCALEDIR" | grep "\\$"
do
	LOCALEDIR=`eval echo "$LOCALEDIR"`
done > /dev/null 2> /dev/null
AC_DEFINE_UNQUOTED(LOCALEDIR, "$LOCALEDIR", [Directory containing locales])
AC_SUBST(LOCALEDIR)

# Create LIBDIR #define for config.h
LIBDIR=`eval echo "$libdir"`
AC_DEFINE_UNQUOTED(LIBDIR, "$LIBDIR", [Directory containing libraries])
AC_SUBST(LIBDIR)

EL_LOG_CONFIG(CONFDIR, [System configuration directory], [])
EL_LOG_CONFIG(LOCALEDIR, [Locale catalogs directory], [])

# ===================================================================
# A little fine tuning of gcc specific options (continued)
# ===================================================================

if test "x$ac_cv_c_compiler_gnu" = "xyes"; then
  if test "$CONFIG_DEBUG" = "yes"; then
    # We want to see all warnings and live with none (in debug mode).
    CFLAGS="$CFLAGS -Werror"
  fi

  case "`$CC -dumpversion`" in
    3.0|3.1|3.2)
      # These should be ok using -Werror
      ;;
    3.*)
      # If gcc is version 3.3 (or higher?) it emits lots of false positive
      # "dereferencing type-punned pointer will break strict-aliasing rules"
      # warnings. Disable them by not doing any strict-aliasing. The
      # alternative is just too ugly. Thanks gcc guys!! ;)
      CFLAGS="$CFLAGS -fno-strict-aliasing"
      ;;
    4.*)
      # Do not show warnings related to (char * | unsigned char *) type
      # difference.
      CFLAGS="$CFLAGS -fno-strict-aliasing -Wno-pointer-sign"
      ;;
    *)
      # These should be ok using -Werror
      ;;
  esac

  # GCC 4.2.1 warns if we use the address of an object in Boolean context:
  # warning: the address of `builtin_modules' will always evaluate as `true'
  # This hits the object_lock and foreach_module macros in particular.
  # It would be okay to put something in the macros to avoid the warning,
  # but currently this seems to require defining parallel macros that skip
  # the NULL check, and that's too ugly.  So we instead disable the warning.
  # GCC 4.2.1 needs -Wno-address, but GCC 4.2 snapshots need -Wno-always-true.
  # GCC 4.1.3 recognizes neither and exits with code 1 if they are given.
  for warning_flag in -Wno-address -Wno-always-true; do
    AC_MSG_CHECKING([whether $CC accepts $warning_flag])
    EL_SAVE_FLAGS
    CFLAGS="$CFLAGS $warning_flag"
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
      [AC_MSG_RESULT([yes])
       break],
      [AC_MSG_RESULT([no])])
    EL_RESTORE_FLAGS
  done

  # Bug 1012: Some parts of ELinks do arithmetic with signed integers
  # in such a way that an overflow is possible.  GCC 4.2.1 warns
  # "warning: assuming signed overflow does not occur when assuming
  # that (X + c) > X is always true", which may be an incorrect
  # optimization (although allowed by the standard), and breaks the
  # build with -Werror.
  #
  # All of the following tests included -S -Wall -Wextra:
  #
  # GCC: (GNU) 4.0.4 20060507 (prerelease) (Debian 4.0.3-3)
  # * gcc-4.0 -O0: OK, compares the values
  # * gcc-4.0 -O2: assumes no overflow, does not warn
  # * gcc-4.0 -O0 -fno-strict-overflow: unrecognized command line option
  # * gcc-4.0 -O0 -fwrapv: OK, compares the values
  # * gcc-4.0 -O2 -fwrapv: OK, compares the values
  # * gcc-4.0 -O0 -ftrapv: OK, calls __addvsi3
  # * gcc-4.0 -O2 -ftrapv: assumes no overflow, does not warn
  # * gcc-4.0 -O0 -fwrapv -ftrapv: OK, calls __addvsi3
  # * gcc-4.0 -O2 -fwrapv -ftrapv: compares the values
  #
  # GCC: (GNU) 4.1.3 20070812 (prerelease) (Debian 4.1.2-15)
  # * gcc-4.1 -O0: assumes no overflow, does not warn
  # * gcc-4.1 -O2: assumes no overflow, does not warn
  # * gcc-4.1 -O0 -fno-strict-overflow: unrecognized command line option
  # * gcc-4.1 -O0 -fwrapv: OK, compares the values
  # * gcc-4.1 -O2 -fwrapv: OK, compares the values
  # * gcc-4.1 -O0 -ftrapv: OK, calls __addvsi3
  # * gcc-4.1 -O2 -ftrapv: compares the values
  # * gcc-4.1 -O0 -fwrapv -ftrapv: OK, calls __addvsi3
  # * gcc-4.1 -O2 -fwrapv -ftrapv: compares the values
  #
  # GCC: (GNU) 4.2.1 (Debian 4.2.1-5)
  # * gcc-4.2 -O0: OK, compares the values
  # * gcc-4.2 -O2: assumes no overflow, warns about it
  # * gcc-4.2 -O0 -fno-strict-overflow: OK, compares the values
  # * gcc-4.2 -O2 -fno-strict-overflow: OK, compares the values
  # * gcc-4.2 -O0 -fwrapv: OK, compares the values
  # * gcc-4.2 -O2 -fwrapv: OK, compares the values
  # * gcc-4.2 -O0 -ftrapv: OK, calls __addvsi3
  # * gcc-4.2 -O2 -ftrapv: compares the values
  # * gcc-4.2 -O0 -fwrapv -ftrapv: OK, calls __addvsi3
  # * gcc-4.2 -O2 -fwrapv -ftrapv: compares the values
  #
  # Apparently, -ftrapv does not work reliably at all.
  for overflow_flag in -fno-strict-overflow -fwrapv; do
    AC_MSG_CHECKING([whether $CC accepts $overflow_flag])
    EL_SAVE_FLAGS
    CFLAGS="$CFLAGS $overflow_flag"
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
      [AC_MSG_RESULT([yes])
       break],
      [AC_MSG_RESULT([no])])
    EL_RESTORE_FLAGS
  done
fi

EL_LOG_CONFIG(CFLAGS, [Compiler flags (CFLAGS)], [])
EL_LOG_CONFIG(CPPFLAGS, [Preprocessor flags (CPPFLAGS)], [])
EL_LOG_CONFIG(LDFLAGS, [Linker flags (LDFLAGS)], [])
EL_LOG_CONFIG(LIBS, [Library flags (LIBS)], [])

# ===================================================================
# Colored make output
# ===================================================================

if test $(`which tput` colors) -ge 4; then
	MAKE_COLOR=1
	AC_SUBST(MAKE_COLOR)
fi

# ===================================================================
# Generated files
# ===================================================================

AC_CONFIG_FILES([ \
 Makefile.config \
 contrib/elinks.spec \
 contrib/lua/hooks.lua \
 contrib/conv/w3m2links.awk \
 doc/Doxyfile \
 doc/man/man1/elinks.1 \
 src/intl/gettext/ref-add.sed \
 src/intl/gettext/ref-del.sed
])
AC_OUTPUT

abs_srcdir="$(cd "$srcdir" && pwd)"
# builddir is always absolute!
if test "$abs_srcdir" != "$builddir"; then
	# Bootstrap the Makefile creation
	echo "include $abs_srcdir/Makefile" > "$builddir/Makefile"
	"$MAKE" "SRC=$abs_srcdir" init

	# Make cg-status ignore this build directory
	echo "*" > "$builddir/.gitignore"
fi

# ===================================================================
# Configuration summary
# ===================================================================

AC_MSG_RESULT(The following feature summary has been saved to features.log)
cat features.log