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 2.61 is installed in the computer that generates our nightly
dnl snapshots, so we need to be compatible with that.  (Also, some files
dnl in Autoconf 2.62 and 2.63 sources are not GPLv2 compatible.)
AC_PREREQ(2.61)
AC_INIT
AC_CONFIG_SRCDIR([src/main/main.c])
AC_CONFIG_AUX_DIR(config)

PACKAGE=elinks
VERSION=0.13.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"
test -f "$srcdir/$features" && . "$srcdir/$features"
test -f "$builddir/$features" && . "$builddir/$features"
echo "Feature summary:" > features.log

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

AC_PROG_CC
AC_CHECK_TOOL([LD], [ld])
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$CONFIG_DOC" != xno; then
	AC_PATH_PROGS(PYTHON, "python")
	if test "x$PYTHON" != "x"; then
		EL_CONFIG(CONFIG_ASCIIDOC, [AsciiDoc])
		EL_CONFIG(MANUAL_ASCIIDOC, [HTML (one file)])
		EL_CONFIG(MAN_ASCIIDOC, [HTML])
	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(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(wchar.h 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(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([net/if.h], [], [],
[[#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h> /* <net/if.h> on Mac OS X 10.5.4 needs this */
#endif
]])
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
AC_MSG_CHECKING([[for C99-conforming inline]])
AC_COMPILE_IFELSE([[
	int add(int change);

	static int sum;

	inline int
	add(int change)
	{
		sum += change;
		return sum;
	}

	int
	sub(int change)
	{
		return add(-change);
	}]],
	[AC_MSG_RESULT([[yes]])
	 AC_DEFINE([NONSTATIC_INLINE], [inline],
		[Define as inline if the compiler lets you declare a function without inline, then define it with inline, and have that definition refer to identifiers with internal linkage.  This is allowed by C99 6.7.4p6 and 6.7.4p3 together.  Otherwise define as nothing.])],
	[AC_MSG_RESULT([[no]])
	 AC_DEFINE([NONSTATIC_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");])

# ===================================================================
# 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(setitimer, HAVE_SETITIMER=yes)

AC_CHECK_FUNCS([cygwin_conv_to_full_win32_path])

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

AC_CHECK_FUNCS(wcwidth, HAVE_WCWIDTH=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)

AC_CHECK_FUNCS(fpathconf, HAVE_FPATHCONF=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_$1" &&
			   test "x[$]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],
[
	if test "x[$]$1" != xno; then $1=yes; fi
	WITHVAL_$1=

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

# LZMA disabled by default, because of little usability and compilation problems
# with new xz
EL_CONFIG_OPTIONAL_LIBRARY(CONFIG_LZMA, lzma, lzma.h, lzma, lzma_code,
	[  --with-lzma             enable 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 SpiderMonkey, optional even if installed.
# ===================================================================

# This option sets the $with_spidermonkey variable.
AC_ARG_WITH([spidermonkey],
	[AS_HELP_STRING([--without-spidermonkey],
		[disable SpiderMonkey Mozilla JavaScript engine support])])

# CONFIG_SPIDERMONKEY is initially blank.  We change it to "yes" or "no"
# when we know for sure whether we're going to use SpiderMonkey or not.
# (features.conf is not supposed to define it.)
CONFIG_SPIDERMONKEY=
EL_SAVE_FLAGS

case "$with_spidermonkey" in
	no)
		# The user specified --without-spidermonkey.
		# That overrides the other SpiderMonkey options.
		AC_MSG_CHECKING([for SpiderMonkey])
		AC_MSG_RESULT([disabled])
		CONFIG_SPIDERMONKEY="no"
		;;
	"" | yes)
		;;
	*)
		AC_MSG_WARN([This version of ELinks does not support --with-spidermonkey=DIRECTORY.])
		;;
esac

# The SpiderMonkey 1.8.5 standalone sources install mozjs185.pc,
# but the Debian libmozjs-dev package installs mozilla-js.pc.
# Check mozjs185 first, because it has the version number in the name
# and therefore is less likely to be a newer incompatible version.
# (This configure script rejects older incompatible versions
# but can let newer ones through.)
for package in mozjs185 mozilla-js; do
	if test -n "$CONFIG_SPIDERMONKEY"; then
		break
	else
		AC_MSG_CHECKING([for SpiderMonkey (1.8.5 or later) in pkg-config $package])
		# In pkg-config 0.25, pkg-config --exists mozjs185
		# returns 0 (success) even if mozjs185 depends on
		# nspr, which has not been installed.  However,
		# pkg-config --cflags mozjs185 returns 1 then.
		if pkg-config --cflags --libs $package > /dev/null 2>&AS_MESSAGE_LOG_FD; then
			SPIDERMONKEY_LIBS="$(pkg-config --libs $package)"
			SPIDERMONKEY_CFLAGS="$(pkg-config --cflags $package)"
			LIBS="$SPIDERMONKEY_LIBS $LIBS_X"
			CFLAGS="$CFLAGS_X $SPIDERMONKEY_CFLAGS"
			CPPFLAGS="$CPPFLAGS_X $SPIDERMONKEY_CFLAGS"
			AC_LINK_IFELSE(
				[AC_LANG_PROGRAM([[
					/* mozilla-js.pc may have -DXP_UNIX or similar in Cflags.
					 * Avoid warnings about conflicting definitions.  */
					#if !defined(XP_BEOS) && !defined(XP_OS2) && !defined(XP_UNIX) && !defined(XP_WIN)
					# define XP_UNIX 1
					#endif
					#include <jsapi.h>
					#ifndef JS_VERSION
					# error <jsapi.h> did not define JS_VERSION
					#elif JS_VERSION < 185
					# error too old
					#endif]], [])],
				[CONFIG_SPIDERMONKEY=yes
				 AC_MSG_RESULT([yes])],
				[# Leave CONFIG_SPIDERMONKEY blank, to continue the search.
				 AC_MSG_RESULT([found but unusable])])
		else
			AC_MSG_RESULT([no])
		fi
	fi
done

if test -z "$CONFIG_SPIDERMONKEY"; then
	# Didn't find SpiderMonkey anywhere.
	CONFIG_SPIDERMONKEY=no
fi

if test "$CONFIG_SPIDERMONKEY" = "yes"; then
	# LIBS, CFLAGS, and CPPFLAGS still include the SpiderMonkey options.
	AC_CHECK_FUNCS([JS_ReportAllocationOverflow])
	AC_CHECK_FUNCS([JS_SetBranchCallback])
	AC_CHECK_FUNCS([JS_TriggerOperationCallback], [HAVE_JS_TRIGGEROPERATIONCALLBACK=yes])
elif test -n "$with_spidermonkey" && test "x$with_spidermonkey" != "xno"; then
	AC_MSG_WARN([SpiderMonkey was not found even though you specified --with-spidermonkey.])
fi
EL_RESTORE_FLAGS

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

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

if test "x$CONFIG_ECMASCRIPT_SMJS" = xyes &&
   test "x$HAVE_JS_TRIGGEROPERATIONCALLBACK" = xyes &&
   test "x$HAVE_SETITIMER" = xyes; then
	EL_CONFIG(CONFIG_ECMASCRIPT_SMJS_HEARTBEAT, [ECMAScript heartbeat support])
else
	CONFIG_ECMASCRIPT_SMJS_HEARTBEAT=no
fi
AC_SUBST(CONFIG_ECMASCRIPT_SMJS_HEARTBEAT)


# ===================================================================
# 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 "$withval" "" /usr /usr/local; do
		for suffix in "" 5.1 51; do
			if test "$cf_result" = no && ( test -f "$luadir/include/lua.h" || \
			   test -f "$luadir/include/lua$suffix/lua.h" ) ; then
				LUA_LIBS="-L$luadir/lib -llua$suffix -lm"
				LUA_CFLAGS="-I$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 <lauxlib.h>]
						#include <lua.h>
						#include <lualib.h>
						], [[	lua_State *L = luaL_newstate();
						luaL_openlibs(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 TRE library
# ===================================================================
#
# This section only checks that --without-tre is not given and the
# library seems to work, and sets TRE_CFLAGS, TRE_LIBS, and
# tre_log.  It does not define CONFIG_TRE, and always resets
# LIBS and CFLAGS back to their original values.
#
# After any --enable-utf-8 and --disable-utf-8 options have been
# handled, a separate section decides whether to actually use TRE.
#
# tre version 0.8.0 or higher is required which have the "tre_" prefix
# for functions.

AC_ARG_WITH([[tre]], [[  --without-tre           disable TRE regex search support]])
if test "$with_tre" = no; then
	AC_MSG_CHECKING([[for TRE]])
	AC_MSG_RESULT([[disabled]])
	tre_log="no (explicitly disabled)"
else
	AC_MSG_CHECKING([[for TRE in pkg-config]])
	if pkg-config tre; then
		TRE_CFLAGS=`pkg-config --cflags tre`
		TRE_LIBS=`pkg-config --libs tre`
		AC_MSG_RESULT([[yes]])
	else
		# <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=513055>
		# "libtre-dev: /usr/lib/pkgconfig/tre.pc missing"
		# so we look for the library even if pkg-config doesn't know about it.
		TRE_CFLAGS=
		TRE_LIBS=-ltre
		AC_MSG_RESULT([[no, but let's try defaults]])
	fi

	AC_MSG_CHECKING([[for TRE header and library]])
	EL_SAVE_FLAGS
	CFLAGS="$TRE_CFLAGS $CFLAGS"
	LIBS="$TRE_LIBS $LIBS" # must be first, because of regfree conflict
	AC_TRY_LINK([#include <tre/tre.h>],
		    [regex_t re;
		     regmatch_t match[1];
		     tre_regwcomp(&re, L"zap", REG_ICASE);
		     tre_regwexec(&re, L"ELIZAPROGRAM", 1, match, 0);],
		    [AC_MSG_RESULT([[yes]])
		     tre_log="available"],
		    [AC_MSG_RESULT([[no]])
		     tre_log="no (TRE not found)"])
	EL_RESTORE_FLAGS
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

chosen_ssl_library=""

AC_ARG_WITH(gnutls, [[  --without-gnutls        disable GNUTLS SSL support]])
AC_ARG_WITH(gnutls, [[  --with-gnutls           enable GNUTLS SSL support]],
	    [case "$with_gnutls" in
		"no")	: ;;
		"yes")	chosen_ssl_library="GNUTLS" ;;
		*)	chosen_ssl_library="GNUTLS"
			AC_MSG_WARN([[Support for --with-gnutls=DIR has been removed.
You may have to set the PKG_CONFIG_PATH environment variable instead.]]) ;;
	     esac])

AC_ARG_WITH(openssl, [[  --without-openssl       disable OpenSSL support]])
AC_ARG_WITH(openssl, [[  --with-openssl[=DIR]    enable OpenSSL support (default)]],
	    [case "$with_openssl" in
		"no")	: ;;
		*)	chosen_ssl_library="OpenSSL" ;;
	     esac])

AC_ARG_WITH(nss_compat_ossl, [[  --with-nss_compat_ossl[=DIR]
                          NSS compatibility SSL libraries/include files]],
	    [case "$with_nss_compat_ossl" in
		"no")	: ;;
		*)	chosen_ssl_library="nss_compat_ossl" ;;
	     esac])

# ---- nss_compat_ossl

if test "$with_nss_compat_ossl" = no; then
	# explicitly disabled
	:
elif test -n "$chosen_ssl_library" && test "$chosen_ssl_library" != "nss_compat_ossl"; then
	# not used, because $chosen_ssl_library was chosen
	:
elif test -z "${with_nss_compat_ossl+set}"; then
	# SSL_library_init() in nss_compat_ossl 0.9.2 calls exit(1)
	# with no error message if there is no certificate database.
	# https://bugzilla.redhat.com/show_bug.cgi?id=463437
	# So ELinks uses nss_compat_ossl only if explicitly requested.
	:
else
	EL_SAVE_FLAGS
	if test "$with_nss_compat_ossl" = yes; then
		if pkg-config nss; then
			CFLAGS="$CFLAGS_X `pkg-config --cflags nss`"
			LIBS="$LIBS_X `pkg-config --libs nss`"
		else
			with_nss_compat_ossl=no
		fi
	else
		# Without pkg-config, we'll kludge in some defaults
		CFLAGS="$CFLAGS_X -I$with_nss_compat_ossl/include -I/usr/include/nss3 -I/usr/include/nspr4"
		LIBS="$LIBS_X -L$with_nss_compat_ossl/lib -lssl3 -lsmime3 -lnss3 -lplds4 -lplc4 -lnspr4 -lpthread -ldl"
	fi
	AC_CHECK_HEADERS(nss_compat_ossl/nss_compat_ossl.h,, [with_nss_compat_ossl=no], [#define NSS_COMPAT_OSSL_H])
	AC_CHECK_LIB(nss_compat_ossl, X509_free,, [with_nss_compat_ossl=no])

	if test "$with_nss_compat_ossl" = "no"; then
		EL_RESTORE_FLAGS
	else
		LIBS="$LIBS -lnss_compat_ossl"
		EL_CONFIG(CONFIG_NSS_COMPAT_OSSL, [nss_compat_ossl])
		chosen_ssl_library="nss_compat_ossl"
	fi
fi

# ---- OpenSSL

AC_MSG_CHECKING([for OpenSSL])

EL_SAVE_FLAGS

if test "$with_openssl" = no; then
	cf_result="explicitly disabled"

elif test -n "$chosen_ssl_library" && test "$chosen_ssl_library" != "OpenSSL"; then
	cf_result="not used, because $chosen_ssl_library was chosen"

else
	cf_result=no
	for ssldir in "$with_openssl" "" /usr /usr/local/openssl \
			 /usr/lib/openssl /usr/local/ssl \
			 /usr/local/www /usr/lib/ssl /usr/local \
			 /usr/pkg /opt /opt/openssl; do
		if test "$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 "$cf_result" != yes; then
		if test "${with_openssl-no}" != "no"; then
			AC_MSG_ERROR([OpenSSL not found])
		fi
		EL_RESTORE_FLAGS
	else
		EL_CONFIG(CONFIG_OPENSSL, [OpenSSL])
		chosen_ssl_library="OpenSSL"

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

AC_MSG_RESULT($cf_result)

# ---- GNU TLS

# GnuTLS 2.2.0 changed libgnutls-openssl from GPLv2+
# to GPLv3+.  Don't link that with the GPLv2 ELinks.
# ELinks will use its internal MD5 code instead.
CONFIG_GNUTLS_OPENSSL_COMPAT=no

if test "$with_gnutls" = no; then
	AC_MSG_CHECKING([[for GNUTLS]])
	AC_MSG_RESULT([[explicitly disabled]])

elif test -n "$chosen_ssl_library" && test "$chosen_ssl_library" != "GNUTLS"; then
	AC_MSG_CHECKING([[for GNUTLS]])
	AC_MSG_RESULT([[not used, because $chosen_ssl_library was chosen]])

else
	cf_result=no
	AC_MSG_CHECKING([[for GNUTLS (1.2 or later) in pkg-config]])
	if pkg-config --atleast-version=1.2 gnutls; then
		GNUTLS_CFLAGS=`pkg-config --cflags gnutls`
		GNUTLS_LIBS=`pkg-config --libs gnutls`
		AC_MSG_RESULT([[yes: $GNUTLS_CFLAGS $GNUTLS_LIBS]])

		EL_SAVE_FLAGS
		LIBS="$GNUTLS_LIBS $LIBS"
		CFLAGS="$CFLAGS $GNUTLS_CFLAGS"
		CPPFLAGS="$CPPFLAGS $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_MSG_CHECKING([[whether GNUTLS can be linked with]])
		AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <gnutls/gnutls.h>]],
						[[gnutls_session_t dummy;
						  gnutls_check_version(NULL)]])],
			       [cf_result=yes],
			       [cf_result=no])
		AC_MSG_RESULT([[$cf_result]])

		if test "$cf_result" = yes; then
			# According to gnutls/NEWS, the function was originally
			# added as gnutls_set_default_priority2 in GNUTLS 2.1.4
			# (released 2007-10-27) and then renamed to
			# gnutls_priority_set_direct in GNUTLS 2.1.7 (released
			# 2007-11-29).
			AC_CHECK_FUNCS([gnutls_priority_set_direct])
		fi

		EL_RESTORE_FLAGS
	else
		AC_MSG_RESULT([[$cf_result]])
	fi

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

		# gcry_create_nounce is part of libgcrypt
		LIBGCRYPT_CFLAGS=`libgcrypt-config --cflags`
		LIBGCRYPT_LIBS=`libgcrypt-config --libs`

		LIBS="$LIBGCRYPT_LIBS $GNUTLS_LIBS $LIBS"
		AC_SUBST(LIBGCRYPT_CFLAGS)
		AC_SUBST(GNUTLS_CFLAGS)

	elif test "${with_gnutls-no}" != "no"; then
		AC_MSG_ERROR([[GNUTLS (1.2 or later) not found.  ELinks no longer supports GNUTLS 1.1.]])
	fi
fi

# Final SSL setup

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

#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

# iconv is always used
LIBS="$LIBS $LIBICONV"

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])

EL_ARG_DEPEND(CONFIG_COMBINE, combining, [CONFIG_UTF8:yes HAVE_WCWIDTH:yes], [Combining characters],
	      [  --enable-combining      support Unicode combining characters (experimental)])


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


# ===================================================================
# Decide whether to use TRE
# ===================================================================
#
# This must be done after the CONFIG_UTF8 check above.
# The first part of the TRE check is separate, to get
# the configure --help output in a sensible order.
#
# After this section, nothing else must be added to the
# beginning of $LIBS.

if test "$tre_log" = "available"; then
	if test "$CONFIG_UTF8" = "yes"; then
		# When CONFIG_UTF8 and CONFIG_TRE are both defined,
		# src/viewer/text/search.c makes a string of
		# unicode_val_T and gives it to regwexec(), which
		# expects a string of wchar_t.  If the unicode_val_T
		# and wchar_t types are too different, this won't
		# work, so try to detect that and disable regexp
		# operations entirely in that case.
		#
		# Currently, this code only compares the sizes of the
		# types.  src/intl/charsets.h defines unicode_val_T as
		# uint32_t, so we check whether wchar_t has exactly 32
		# bits.  But don't use AC_CHECK_SIZEOF for this, because
		# there doesn't seem to be a documented way to get the
		# result of that for use in the configure script.
		#
		# C99 says the implementation can define
		# __STDC_ISO_10646__ if wchar_t values match ISO 10646
		# (or Unicode) numbers in all locales.  Do not check
		# that macro here, because it is too restrictive: it
		# should be enough for ELinks if the values match in
		# the locales where ELinks is actually run.
		AC_MSG_CHECKING([[whether wchar_t is exactly 32-bit]])
		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <limits.h>
#include <stddef.h>
int dummy[(sizeof(wchar_t) * CHAR_BIT == 32) ? 1 : -1];]], [])],
			[AC_MSG_RESULT([[yes]])
			 tre_log="TRE"],
			[AC_MSG_RESULT([[no]])
			 tre_log="no (unsuitable wchar_t)"])
	else
		# If UTF-8 is not used, then wchar_t doesn't matter.
		tre_log="TRE"
	fi
fi

if test "$tre_log" = "TRE"; then
	AC_DEFINE([CONFIG_TRE], [1],
		[Define as 1 to use the TRE library for regular expression searching.  This requires the <tre/regex.h> header file.  If you define CONFIG_UTF8 too, then wchar_t must be exactly 32-bit so that it matches unicode_val_T.])
	# TRE_CFLAGS will be used only where needed.
	#
	# Bug 1081: If both TRE and libc define the regfree function,
	# ELinks needs to use the version defined by TRE because
	# that's the one compatible with regex_t initialized by the
	# regwcomp function of TRE.  Therefore put $TRE_LIBS at the
	# very beginning of $LIBS so that the linker hopefully finds
	# regfree there before it examines libc.  In particular,
	# $PERL_LIBS appears to often include "-lc".
	#
	# This scheme still risks a crash if ELinks is linked with
	# some static library that uses GNU <regex.h> extensions that
	# TRE does not implement.  For example, the library might call
	# re_compile_pattern, which is found in GNU libc, and then
	# regfree, which is found in TRE and probably crashes with the
	# GNU-initialized regex_t.  Ways to avoid such crashes:
	#
	# - Change TRE so it defines only tre_... functions and does
	#   not attempt to override the POSIX names by default.
	#
	# - Change ELinks to access TRE only via dlopen and dlsym.
	#   The problem then is how to find the correct file name.
	#   There might be libtre.so.4 and libtre.so.5 with different
	#   ABI.  How can this configure script detect which of them
	#   matches the <tre/regex.h> in the include path?
	#
	# - Replace the static library with a shared library.  At
	#   least on GNU/Linux, when the shared library is built, the
	#   linker should note that e.g. regfree is defined in libc
	#   and has the GLIBC_2.0 version there, and write that
	#   version string to the shared library as well; because TRE
	#   does not provide regfree with that version, any regfree
	#   calls at run time should then get resolved to libc.
	LIBS="$TRE_LIBS $LIBS"
else
	TRE_LIBS=
	TRE_CFLAGS=
fi
AC_SUBST(TRE_CFLAGS)
AC_SUBST(TRE_LIBS)
EL_LOG_CONFIG([CONFIG_TRE], [[Regexp searching]], [[$tre_log]])


# ===================================================================
# Further LDFLAGS tweaks
# ===================================================================

# == EMX hack

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


# 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".)
#
# With Sun Studio 11 on Solaris 9, we get "cc: Warning: illegal option
# -dynamic"; then, cc proceeds anyway, but the option can prevent the
# linker from finding the libraries listed in -l operands.  So this
# -rdynamic check needs to happen after the libraries have already
# been added to $LDFLAGS.
AC_MSG_CHECKING([for -rdynamic])
LDFLAGS_X="$LDFLAGS"
LDFLAGS="-rdynamic $LDFLAGS"
AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[have_rdynamic=yes],[have_rdynamic=no])
test "$have_rdynamic" = no && LDFLAGS="$LDFLAGS_X"
AC_MSG_RESULT($have_rdynamic)

# ===================================================================
# 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], [])


AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h>
]], [[#if !defined(__TINYC__) || !defined(alloca)
	#error not tcc
	#endif ]])],[cf_result=yes],[cf_result=no])

if test "$cf_result" = "yes"; then
	AC_DEFINE([HAVE_ALLOCA])
	AC_DEFINE([_ALLOCA_H], [1], [Define as 1 if you are using Tiny C Compiler
		with the GNU C Library,	and <alloca.h> of glibc would otherwise
		override the alloca macro defined in <stddef.h> of TCC.
		If <alloca.h> of glibc sees the _ALLOCA_H macro, it assumes
		it has already been included, and does not redefine alloca.
		This might not work in future glibc versions though, because
		the names of the #include guard macros are not documented.
		The incompatibility has been reported to the tinycc-devel
		mailing list on 2008-07-14.  If a future version of TCC provides
		an <alloca.h> of its own, this hack won't be needed.])
fi
# ===================================================================
# 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"
      ;;
    4.5*)
      CFLAGS="$CFLAGS -fno-strict-aliasing -Wno-pointer-sign -Wno-enum-compare"
      ;;
    4.*)
      # Do not show warnings related to (char * | unsigned char *) type
      # difference.
      CFLAGS="$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
