Pulling in latest software construction toolkit.

site_scons/site_tools/defer.py

 #!/usr/bin/python2.4
 # Copyright 2008, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
@@ skipping 16 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 """Defer tool for SCons."""
 
 
 import os
 import sys
 import types
-
+import SCons.Errors
 
 __defer_groups = {}
 
 
 def _InitializeDefer(self):
   """Re-initializes deferred function handling.
 
   Args:
     self: Parent environment
   """
@@ skipping 18 matching lines @@
         continue        # Still have dependencies
       if group.func_env_cwd:
         # Run all the functions in our named group
         for func, env, cwd in group.func_env_cwd:
           os.chdir(cwd)
           func(env)
       did_work = True
       del __defer_groups[name]
       break
     if not did_work:
-      print 'Error in _ExecuteDefer: dependency cycle detected.'
+      errmsg = 'Error in _ExecuteDefer: dependency cycle detected.\n'
       for name, group in __defer_groups.items():
-        print '   %s after: %s' % (name, group.after)
-      # TODO(rspangler): should throw exception?
-      sys.exit(1)
+        errmsg += '   %s after: %s\n' % (name, group.after)
+      raise SCons.Errors.UserError(errmsg)
 
   # Restore directory
   os.chdir(oldcwd)
 
 
 class DeferFunc(object):
   """Named list of functions to be deferred."""
 
   def __init__(self):
     """Initialize deferred function object."""
@@ skipping 54 matching lines @@
 
   # Get list of names and/or functions this function should defer until after
   after = []
   for a in self.Flatten(kwargs.get('after')):
     if isinstance(a, str):
       after.append(a)
     elif isinstance(a, types.FunctionType):
       after.append(a.__name__)
     elif a is not None:
       # Deferring
-      # TODO(rspangler): should throw an exception
-      print ('Warning: Defer can only wait for functions or names; ignoring'
-             'after = ', a)
+      raise ValueError('Defer after=%r is not a function or name' % a)
 
   # Find the deferred function
   if name not in __defer_groups:
     __defer_groups[name] = DeferFunc()
   group = __defer_groups[name]
 
   # If we were given a function, also save environment and current directory
   if func:
     group.func_env_cwd.append((func, self, os.getcwd()))
 
   # Add dependencies for the function
   group.after.update(after)
 
 
 def generate(env):
   # NOTE: SCons requires the use of this name, which fails gpylint.
   """SCons entry point for this tool."""
 
   env.AddMethod(_InitializeDefer)
   env.AddMethod(_ExecuteDefer)
   env.AddMethod(Defer)