scons: Move common code to a separate file.

SConstruct

 #######################################################################
 # Top-level SConstruct
-
-import os
-import os.path
-import sys
-import platform as _platform
-
-
-#######################################################################
-# Configuration options
 #
 # For example, invoke scons as 
 #
@@ -29,33 +20,21 @@ import platform as _platform
 # to get the full list of options. See scons manpage for more info.
 #  
 
-platform_map = {
-	'linux2': 'linux',
-	'win32': 'winddk',
-}
-default_platform = sys.platform
-default_platform = platform_map.get(default_platform, default_platform)
-
-machine_map = {
-	'x86': 'x86',
-	'i386': 'x86',
-	'i486': 'x86',
-	'i586': 'x86',
-	'i686': 'x86',
-	'x86_64': 'x86_64',
-}
-if 'PROCESSOR_ARCHITECTURE' in os.environ:
-	default_machine = os.environ['PROCESSOR_ARCHITECTURE']
-else:
-	default_machine = _platform.machine()
-default_machine = machine_map.get(default_machine, 'generic')
+import os
+import os.path
+import sys
+
+import common
+
+#######################################################################
+# Configuration options
 
-if default_platform in ('linux', 'freebsd', 'darwin'):
+if common.default_platform in ('linux', 'freebsd', 'darwin'):
 	default_statetrackers = 'mesa'
 	default_drivers = 'softpipe,failover,i915simple,i965simple'
 	default_winsys = 'xlib'
 	default_dri = 'yes'
-elif default_platform in ('winddk',):
+elif common.default_platform in ('winddk',):
 	default_statetrackers = 'none'
 	default_drivers = 'softpipe,i915simple'
 	default_winsys = 'none'
@@ -65,36 +44,13 @@ else:
 	default_winsys = 'all'
 	default_dri = 'no'
 
-
-# TODO: auto-detect defaults
-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')))
-opts.Add(EnumOption('platform', 'target platform', default_platform,
-                     allowed_values=('linux', 'cell', 'winddk')))
+opts = common.Options()
 opts.Add(ListOption('statetrackers', 'state_trackers to build', default_statetrackers,
-                     [
-                     	'mesa', 
-                     ],
-                     ))
+                     ['mesa']))
 opts.Add(ListOption('drivers', 'pipe drivers to build', default_drivers,
-                     [
-                     	'softpipe', 
-                     	'failover', 
-                     	'i915simple', 
-                     	'i965simple', 
-                     	'cell',
-                     ],
-                     ))
+                     ['softpipe', 'failover', 'i915simple', 'i965simple', 'cell']))
 opts.Add(ListOption('winsys', 'winsys drivers to build', default_winsys,
-                     [
-                     	'xlib', 
-                     	'intel',
-                     ],
-                     ))
-opts.Add(BoolOption('llvm', 'use LLVM', 'no'))
-opts.Add(BoolOption('dri', 'build DRI drivers', default_dri))
+                     ['xlib', 'intel'])) 
 
 env = Environment(
 	options = opts, 
@@ -264,64 +220,20 @@ if platform not in ('winddk',):
 		'Xfixes',
 	])
 
-Export('env')
-
-
-#######################################################################
-# Convenience Library Builder
-# based on the stock StaticLibrary and SharedLibrary builders
-
-def createConvenienceLibBuilder(env):
-    """This is a utility function that creates the ConvenienceLibrary
-    Builder in an Environment if it is not there already.
-
-    If it is already there, we return the existing one.
-    """
-
-    try:
-        convenience_lib = env['BUILDERS']['ConvenienceLibrary']
-    except KeyError:
-        action_list = [ Action("$ARCOM", "$ARCOMSTR") ]
-        if env.Detect('ranlib'):
-            ranlib_action = Action("$RANLIBCOM", "$RANLIBCOMSTR")
-            action_list.append(ranlib_action)
+# Convenience library support
+common.createConvenienceLibBuilder(env)
 
-        convenience_lib = Builder(action = action_list,
-                                  emitter = '$LIBEMITTER',
-                                  prefix = '$LIBPREFIX',
-                                  suffix = '$LIBSUFFIX',
-                                  src_suffix = '$SHOBJSUFFIX',
-                                  src_builder = 'SharedObject')
-        env['BUILDERS']['ConvenienceLibrary'] = convenience_lib
-        env['BUILDERS']['Library'] = convenience_lib
-
-    return convenience_lib
-
-createConvenienceLibBuilder(env)
+Export('env')
 
 
 #######################################################################
 # Invoke SConscripts
 
-# Put build output in a separate dir, which depends on the current configuration
-# See also http://www.scons.org/wiki/AdvancedBuildExample
-build_topdir = 'build'
-build_subdir = platform
-if dri:
-	build_subdir += "-dri"
-if llvm:
-	build_subdir += "-llvm"
-if env['machine'] != 'generic':
-	build_subdir += '-' + env['machine']
-if debug:
-	build_subdir += "-debug"
-build_dir = os.path.join(build_topdir, build_subdir)
-
 # TODO: Build several variants at the same time?
 # http://www.scons.org/wiki/SimultaneousVariantBuilds
 
 SConscript(
 	'src/SConscript',
-	build_dir = build_dir,
+	build_dir = common.make_build_dir(env),
 	duplicate = 0 # http://www.scons.org/doc/0.97/HTML/scons-user/x2261.html
 )

common.py

+#######################################################################
+# Common SCons code
+
+import os
+import os.path
+import sys
+import platform as _platform
+
+
+#######################################################################
+# Defaults
+
+_platform_map = {
+	'linux2': 'linux',
+	'win32': 'winddk',
+}
+
+default_platform = sys.platform
+default_platform = _platform_map.get(default_platform, default_platform)
+
+_machine_map = {
+	'x86': 'x86',
+	'i386': 'x86',
+	'i486': 'x86',
+	'i586': 'x86',
+	'i686': 'x86',
+	'x86_64': 'x86_64',
+}
+if 'PROCESSOR_ARCHITECTURE' in os.environ:
+	default_machine = os.environ['PROCESSOR_ARCHITECTURE']
+else:
+	default_machine = _platform.machine()
+default_machine = _machine_map.get(default_machine, 'generic')
+
+if default_platform in ('linux', 'freebsd', 'darwin'):
+	default_dri = 'yes'
+elif default_platform in ('winddk',):
+	default_dri = 'no'
+else:
+	default_dri = 'no'
+
+
+#######################################################################
+# Common options
+
+def Options():
+	from SCons.Options import Options
+	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')))
+	opts.Add(EnumOption('platform', 'target platform', default_platform,
+											 allowed_values=('linux', 'cell', 'winddk')))
+	opts.Add(BoolOption('llvm', 'use LLVM', 'no'))
+	opts.Add(BoolOption('dri', 'build DRI drivers', default_dri))
+	return opts
+
+
+#######################################################################
+# Convenience Library Builder
+# based on the stock StaticLibrary and SharedLibrary builders
+
+import SCons.Action
+import SCons.Builder
+
+def createConvenienceLibBuilder(env):
+    """This is a utility function that creates the ConvenienceLibrary
+    Builder in an Environment if it is not there already.
+
+    If it is already there, we return the existing one.
+    """
+
+    try:
+        convenience_lib = env['BUILDERS']['ConvenienceLibrary']
+    except KeyError:
+        action_list = [ SCons.Action.Action("$ARCOM", "$ARCOMSTR") ]
+        if env.Detect('ranlib'):
+            ranlib_action = SCons.Action.Action("$RANLIBCOM", "$RANLIBCOMSTR")
+            action_list.append(ranlib_action)
+
+        convenience_lib = SCons.Builder.Builder(action = action_list,
+                                  emitter = '$LIBEMITTER',
+                                  prefix = '$LIBPREFIX',
+                                  suffix = '$LIBSUFFIX',
+                                  src_suffix = '$SHOBJSUFFIX',
+                                  src_builder = 'SharedObject')
+        env['BUILDERS']['ConvenienceLibrary'] = convenience_lib
+        env['BUILDERS']['Library'] = convenience_lib
+
+    return convenience_lib
+
+
+#######################################################################
+# Build
+
+def make_build_dir(env):
+	# Put build output in a separate dir, which depends on the current configuration
+	# See also http://www.scons.org/wiki/AdvancedBuildExample
+	build_topdir = 'build'
+	build_subdir = env['platform']
+	if env['dri']:
+		build_subdir += "-dri"
+	if env['llvm']:
+		build_subdir += "-llvm"
+	if env['machine'] != 'generic':
+		build_subdir += '-' + env['machine']
+	if env['debug']:
+		build_subdir += "-debug"
+	build_dir = os.path.join(build_topdir, build_subdir)
+	return build_dir
+