config: add comments for main statements

configure.ac

@@ -20,18 +20,18 @@
 #
 # Process this file with autoconf to produce a configure script
 
+# Initialize Autoconf
 AC_PREREQ([2.60])
 AC_INIT([xf86-video-dummy],
         [0.3.4],
         [https://bugs.freedesktop.org/enter_bug.cgi?product=xorg],
         [xf86-video-dummy])
-
 AC_CONFIG_SRCDIR([Makefile.am])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_AUX_DIR(.)
 
+# Initialize Automake
 AM_INIT_AUTOMAKE([foreign dist-bzip2])
-
 AM_MAINTAINER_MODE
 
 # Require xorg-macros: XORG_DEFAULT_OPTIONS
@@ -40,25 +40,26 @@ m4_ifndef([XORG_MACROS_VERSION],
 XORG_MACROS_VERSION(1.3)
 XORG_DEFAULT_OPTIONS
 
-# Checks for programs.
+# Initialize libtool
 AC_DISABLE_STATIC
 AC_PROG_LIBTOOL
 
 AH_TOP([#include "xorg-server.h"])
 
+# Define a configure option for an alternate module directory
 AC_ARG_WITH(xorg-module-dir, [  --with-xorg-module-dir=DIR ],
                              [ moduledir="$withval" ],
                              [ moduledir="$libdir/xorg/modules" ])
 AC_SUBST(moduledir)
 
 
-# Checks for extensions
+# Store the list of server defined optional extensions in REQUIRED_MODULES
 XORG_DRIVER_CHECK_EXT(RANDR, randrproto)
 XORG_DRIVER_CHECK_EXT(RENDER, renderproto)
 XORG_DRIVER_CHECK_EXT(XV, videoproto)
 XORG_DRIVER_CHECK_EXT(XFreeXDGA, xf86dgaproto)
 
-# Checks for pkg-config packages
+# Obtain compiler/linker options for the driver dependencies
 PKG_CHECK_MODULES(XORG, [xorg-server >= 1.0.99.901] xproto fontsproto $REQUIRED_MODULES)
 
 # Checks for libraries.