scons: Make command line arguments effective again.

SConstruct

@@ -33,18 +33,16 @@ if common.default_platform in ('linux', 'freebsd', 'darwin'):
 	default_statetrackers = 'mesa'
 	default_drivers = 'softpipe,failover,i915simple,i965simple'
 	default_winsys = 'xlib'
-	default_dri = 'yes'
 elif common.default_platform in ('winddk',):
 	default_statetrackers = 'none'
 	default_drivers = 'softpipe,i915simple'
 	default_winsys = 'none'
-	default_dri = 'no'
 else:
 	default_drivers = 'all'
 	default_winsys = 'all'
-	default_dri = 'no'
 
-opts = common.Options()
+opts = Options('config.py')
+common.AddOptions(opts)
 opts.Add(ListOption('statetrackers', 'state_trackers to build', default_statetrackers,
                      ['mesa']))
 opts.Add(ListOption('drivers', 'pipe drivers to build', default_drivers,

common.py

@@ -43,11 +43,9 @@ else:
 #######################################################################
 # Common options
 
-def Options():
-	from SCons.Options import Options
+def AddOptions(opts):
 	from SCons.Options.BoolOption import BoolOption
 	from SCons.Options.EnumOption import EnumOption
-	opts = Options('config.py')
 	opts.Add(BoolOption('debug', 'build debug version', 'no'))
 	opts.Add(EnumOption('machine', 'use machine-specific assembly code', default_machine,
 											 allowed_values=('generic', 'x86', 'x86_64')))
@@ -55,7 +53,6 @@ def Options():
 											 allowed_values=('linux', 'cell', 'winddk')))
 	opts.Add(BoolOption('llvm', 'use LLVM', 'no'))
 	opts.Add(BoolOption('dri', 'build DRI drivers', default_dri))
-	return opts
 
 
 #######################################################################