Merged in dirkbaechle/scons (pull request #208)

A few simple refactorings and optimizations

5 files changed, 28 insertions, 43 deletions

diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index 1c746be1..eecea11b 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -99,8 +99,6 @@ way for wrapping up the functions.
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import SCons.compat
-
 import dis
 import os
 # compat layer imports "cPickle" for us if it's available.
@@ -112,7 +110,6 @@ import subprocess
 import SCons.Debug
 from SCons.Debug import logInstanceCreation
 import SCons.Errors
-import SCons.Executor
 import SCons.Util
 import SCons.Subst
 
@@ -357,21 +354,6 @@ def _do_create_action(act, kw):
     if isinstance(act, ActionBase):
         return act
 
-    if is_List(act):
-        return CommandAction(act, **kw)
-
-    if callable(act):
-        try:
-            gen = kw['generator']
-            del kw['generator']
-        except KeyError:
-            gen = 0
-        if gen:
-            action_type = CommandGeneratorAction
-        else:
-            action_type = FunctionAction
-        return action_type(act, kw)
-
     if is_String(act):
         var=SCons.Util.get_environment_var(act)
         if var:
@@ -388,6 +370,22 @@ def _do_create_action(act, kw):
         # The list of string commands may include a LazyAction, so we
         # reprocess them via _do_create_list_action.
         return _do_create_list_action(commands, kw)
+    
+    if is_List(act):
+        return CommandAction(act, **kw)
+
+    if callable(act):
+        try:
+            gen = kw['generator']
+            del kw['generator']
+        except KeyError:
+            gen = 0
+        if gen:
+            action_type = CommandGeneratorAction
+        else:
+            action_type = FunctionAction
+        return action_type(act, kw)
+
     # Catch a common error case with a nice message:
     if isinstance(act, int) or isinstance(act, float):
         raise TypeError("Don't know how to create an Action from a number (%s)"%act)
diff --git a/src/engine/SCons/ActionTests.py b/src/engine/SCons/ActionTests.py
index b46347df..e069d51d 100644
--- a/src/engine/SCons/ActionTests.py
+++ b/src/engine/SCons/ActionTests.py
@@ -23,8 +23,6 @@
 
 __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
 
-import SCons.compat
-
 # Define a null function and a null class for use as builder actions.
 # Where these are defined in the file seems to affect their byte-code
 # contents, so try to minimize changes by defining them here, before we
diff --git a/src/engine/SCons/Builder.py b/src/engine/SCons/Builder.py
index ed7650a8..c82f6ac6 100644
--- a/src/engine/SCons/Builder.py
+++ b/src/engine/SCons/Builder.py
@@ -107,8 +107,6 @@ from SCons.Debug import logInstanceCreation
 from SCons.Errors import InternalError, UserError
 import SCons.Executor
 import SCons.Memoize
-import SCons.Node
-import SCons.Node.FS
 import SCons.Util
 import SCons.Warnings
 
@@ -862,7 +860,7 @@ class CompositeBuilder(SCons.Util.Proxy):
         self.set_src_suffix(self.cmdgen.src_suffixes())
 
 def is_a_Builder(obj):
-    """"Returns True iff the specified obj is one of our Builder classes.
+    """"Returns True if the specified obj is one of our Builder classes.
 
     The test is complicated a bit by the fact that CompositeBuilder
     is a proxy, not a subclass of BuilderBase.
diff --git a/src/engine/SCons/Executor.py b/src/engine/SCons/Executor.py
index 051d275f..388f8acb 100644
--- a/src/engine/SCons/Executor.py
+++ b/src/engine/SCons/Executor.py
@@ -554,19 +554,20 @@ def AddBatchExecutor(key, executor):
 nullenv = None
 
 
+import SCons.Util
+class NullEnvironment(SCons.Util.Null):
+    import SCons.CacheDir
+    _CacheDir_path = None
+    _CacheDir = SCons.CacheDir.CacheDir(None)
+    def get_CacheDir(self):
+        return self._CacheDir
+
+
 def get_NullEnvironment():
     """Use singleton pattern for Null Environments."""
     global nullenv
 
-    import SCons.Util
-    class NullEnvironment(SCons.Util.Null):
-        import SCons.CacheDir
-        _CacheDir_path = None
-        _CacheDir = SCons.CacheDir.CacheDir(None)
-        def get_CacheDir(self):
-            return self._CacheDir
-
-    if not nullenv:
+    if nullenv is None:
         nullenv = NullEnvironment()
     return nullenv
 
diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index e73dd924..4db1cb33 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -2230,17 +2230,7 @@ class RootDir(Dir):
                 raise SCons.Errors.UserError(msg)
             # There is no Node for this path name, and we're allowed
             # to create it.
-            # (note: would like to use p.rsplit('/',1) here but
-            # that's not in python 2.3)
-            # e.g.: dir_name, file_name = p.rsplit('/',1)
-            last_slash = p.rindex('/')
-            if (last_slash >= 0):
-                dir_name  = p[:last_slash]
-                file_name = p[last_slash+1:]
-            else:
-                dir_name  = p         # shouldn't happen, just in case
-                file_name = ''
-
+            dir_name, file_name = p.rsplit('/',1)
             dir_node = self._lookup_abs(dir_name, Dir)
             result = klass(file_name, dir_node, self.fs)