scons: Add new targets option.

This will likely change. Most probably we'll just add an alias to indvidual
targets and use the regular scons targets arguments.

SConstruct

@@ -53,6 +53,8 @@ opts.Add(ListVariable('drivers', 'pipe drivers to build', default_drivers,
                      ['softpipe', 'failover', 'svga', 'i915', 'i965', 'trace', 'r300', 'identity', 'llvmpipe']))
 opts.Add(ListVariable('winsys', 'winsys drivers to build', default_winsys,
                      ['xlib', 'vmware', 'intel', 'i965', 'gdi', 'radeon']))
+opts.Add(ListVariable('targets', 'target drivers to build', 'all',
+                     ['xlib']))
 
 opts.Add(EnumVariable('MSVS_VERSION', 'MS Visual C++ version', None, allowed_values=('7.1', '8.0', '9.0')))
 

src/SConscript

@@ -1,13 +1,12 @@
 Import('*')
 
 SConscript('glsl/SConscript')
-SConscript('gallium/SConscript')
 
 if 'mesa' in env['statetrackers']:
-	SConscript('mesa/SConscript')
+    SConscript('mesa/SConscript')
 
-SConscript('gallium/winsys/SConscript')
+SConscript('gallium/SConscript')
 
 if platform != 'embedded':
-	SConscript('glut/glx/SConscript')
-	SConscript('glew/SConscript')
+    SConscript('glut/glx/SConscript')
+    SConscript('glew/SConscript')

src/gallium/SConscript

@@ -15,3 +15,7 @@ if platform != 'embedded':
 
 if platform == 'windows':
 	SConscript('state_trackers/wgl/SConscript')
+
+SConscript('winsys/SConscript')
+
+SConscript('targets/SConscript')

src/gallium/targets/SConscript

@@ -5,7 +5,7 @@ Import('*')
 #		'drm/SConscript',
 #	])
 	
-if 'xlib' in env['winsys']:
+if 'xlib' in env['targets']:
 	SConscript([
 		'libgl-xlib/SConscript',
 	])

src/gallium/winsys/xlib/SConscript

@@ -15,13 +15,13 @@ if env['platform'] == 'linux' \
         '#/src/gallium/drivers',
     ])
 
-    st_xlib = env.ConvenienceLibrary(
-	target = 'ws_xlib',
-	source = [
-               'xlib_cell.c',
-               'xlib_llvmpipe.c',
-               'xlib_softpipe.c',
-               'xlib_sw_winsys.c',
-		]
+    ws_xlib = env.ConvenienceLibrary(
+        target = 'ws_xlib',
+        source = [
+           'xlib_cell.c',
+           'xlib_llvmpipe.c',
+           'xlib_softpipe.c',
+           'xlib_sw_winsys.c',
+        ]
     )
     Export('ws_xlib')