* configure.ac: New option --disable-features.

(OPTION_DEFAULT_ON): Change to use enable_features.
* INSTALL: Explain --disable-features.

ChangeLog

+2012-08-07  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	* configure.ac: New option --disable-features.
+	(OPTION_DEFAULT_ON): Change to use enable_features.
+	* INSTALL: Explain --disable-features.
+
 2012-08-07  Glenn Morris  <rgm@gnu.org>
 
 	* configure.ac: Require automake 1.11 (fairly arbitrarily).

INSTALL

@@ -319,6 +319,20 @@ systems which support that.
 
 Use --without-sound to disable sound support.
 
+Use --disable-features if you want to build small executable with
+the minimal dependencies from an external libraries, at the cost
+of disabling most of the features which are enabled by default.
+Using --disable-features is equivalent to --without-sound --without-dbus
+--without-libotf --without-selinux --without-xft --without-gsettings
+--without-gnutls --without-rsvg --without-xml2 --without-gconf
+--without-imagemagick --without-m17n-flt --without-jpeg --without-tiff
+--without-gif --without-png --without-gpm.  Note that --disable-features
+leaves X support enabled, and using GTK2 or GTK3 toolkit creates a lot
+of library dependencies.  So if you want to build small executable with
+the very basic X support, use --disable-features --with-x-toolkit=no.
+For the smallest possible executable without X, use --disable-features
+--without-x.
+
 Use --with-wide-int to implement Emacs values with the type 'long long',
 even on hosts where a narrower type would do.  With this option, on a
 typical 32-bit host, Emacs integers have 62 bits instead of 30.

configure.ac

@@ -48,6 +48,14 @@ archlibdir='${libexecdir}/emacs/${version}/${configuration}'
 docdir='${datadir}/emacs/${version}/etc'
 gamedir='${localstatedir}/games/emacs'
 
+dnl Do not omit a lot of the nice features by default.
+AC_ARG_ENABLE(features,
+[AS_HELP_STRING([--disable-features],
+		[omit almost all features and build
+		small executable with minimal dependencies])],
+  enable_features=$enableval,
+  enable_features=yes)
+
 dnl OPTION_DEFAULT_OFF(NAME, HELP-STRING)
 dnl Create a new --with option that defaults to being disabled.
 dnl NAME is the base name of the option.  The shell variable with_NAME
@@ -63,8 +71,8 @@ AC_DEFUN([OPTION_DEFAULT_OFF], [dnl
 ])dnl
 
 dnl OPTION_DEFAULT_ON(NAME, HELP-STRING)
-dnl Create a new --with option that defaults to being enabled.  NAME
-dnl   is the base name of the option.  The shell variable with_NAME
+dnl Create a new --with option that defaults to $enable_features.
+dnl NAME is the base name of the option.  The shell variable with_NAME
 dnl   will be set either to 'no' (for a plain --without-NAME) or to
 dnl   'yes' (if the option is not specified).  Note that the shell
 dnl   variable name is constructed as autoconf does, by replacing
@@ -72,7 +80,7 @@ dnl   non-alphanumeric characters with "_".
 dnl HELP-STRING is the help text for the option.
 AC_DEFUN([OPTION_DEFAULT_ON], [dnl
   AC_ARG_WITH([$1],[AS_HELP_STRING([--without-$1],[$2])],[],[dnl
-   m4_bpatsubst([with_$1], [[^0-9a-z]], [_])=yes])dnl
+   m4_bpatsubst([with_$1], [[^0-9a-z]], [_])=$enable_features])dnl
 ])dnl
 
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