text: """SCons.Script
  
  This file implements the main() function used by the scons script.
  
  Architecturally, this *is* the scons script, and will likely only be
  called from the external "scons" wrapper.  Consequently, anything here
  should not be, or be considered, part of the build engine.  If it's
  something that we expect other software to want to use, it should go in
  some other module.  If it's specific to the "scons" script invocation,
  it goes here.
  
  """
  
  #
  # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 The SCons Foundation
  #
  # Permission is hereby granted, free of charge, to any person obtaining
  # a copy of this software and associated documentation files (the
  # "Software"), to deal in the Software without restriction, including
  # without limitation the rights to use, copy, modify, merge, publish,
  # distribute, sublicense, and/or sell copies of the Software, and to
  # permit persons to whom the Software is furnished to do so, subject to
  # the following conditions:
  #
  # The above copyright notice and this permission notice shall be included
  # in all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
  # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  #
  
  __revision__ = "src/engine/SCons/Script/Main.py 3842 2008/12/20 22:59:52 scons"
  
  import os
  import os.path
  import string
  import sys
  import time
  import traceback
  
  # Strip the script directory from sys.path() so on case-insensitive
  # (Windows) systems Python doesn't think that the "scons" script is the
  # "SCons" package.  Replace it with our own version directory so, if
  # if they're there, we pick up the right version of the build engine
  # modules.
  #sys.path = [os.path.join(sys.prefix,
  #                         'lib',
  #                         'scons-%d' % SCons.__version__)] + sys.path[1:]
  
  import SCons.CacheDir
  import SCons.Debug
  import SCons.Defaults
  import SCons.Environment
  import SCons.Errors
  import SCons.Job
  import SCons.Node
  import SCons.Node.FS
  import SCons.SConf
  import SCons.Script
  import SCons.Taskmaster
  import SCons.Util
  import SCons.Warnings
  
  import SCons.Script.Interactive
  
  def fetch_win32_parallel_msg():
      # A subsidiary function that exists solely to isolate this import
      # so we don't have to pull it in on all platforms, and so that an
      # in-line "import" statement in the _main() function below doesn't
      # cause warnings about local names shadowing use of the 'SCons'
      # globl in nest scopes and UnboundLocalErrors and the like in some
      # versions (2.1) of Python.
      import SCons.Platform.win32
      return SCons.Platform.win32.parallel_msg
  
  #
  
  class SConsPrintHelpException(Exception):
      pass
  
  display = SCons.Util.display
  progress_display = SCons.Util.DisplayEngine()
  
  first_command_start = None
  last_command_end = None
  
  class Progressor:
      prev = ''
      count = 0
      target_string = '$TARGET'
  
      def __init__(self, obj, interval=1, file=None, overwrite=False):
          if file is None:
              file = sys.stdout
  
          self.obj = obj
          self.file = file
          self.interval = interval
          self.overwrite = overwrite
  
          if callable(obj):
              self.func = obj
          elif SCons.Util.is_List(obj):
              self.func = self.spinner
          elif string.find(obj, self.target_string) != -1:
              self.func = self.replace_string
          else:
              self.func = self.string
  
      def write(self, s):
          self.file.write(s)
          self.file.flush()
          self.prev = s
  
      def erase_previous(self):
          if self.prev:
              length = len(self.prev)
              if self.prev[-1] in ('\n', '\r'):
                  length = length - 1
              self.write(' ' * length + '\r')
              self.prev = ''
  
      def spinner(self, node):
          self.write(self.obj[self.count % len(self.obj)])
  
      def string(self, node):
          self.write(self.obj)
  
      def replace_string(self, node):
          self.write(string.replace(self.obj, self.target_string, str(node)))
  
      def __call__(self, node):
          self.count = self.count + 1
          if (self.count % self.interval) == 0:
              if self.overwrite:
                  self.erase_previous()
              self.func(node)
  
  ProgressObject = SCons.Util.Null()
  
  def Progress(*args, **kw):
      global ProgressObject
      ProgressObject = apply(Progressor, args, kw)
  
  # Task control.
  #
  
  _BuildFailures = []
  
  def GetBuildFailures():
      return _BuildFailures
  
  class BuildTask(SCons.Taskmaster.Task):
      """An SCons build task."""
      progress = ProgressObject
  
      def display(self, message):
          display('scons: ' + message)
  
      def prepare(self):
          self.progress(self.targets[0])
          return SCons.Taskmaster.Task.prepare(self)
  
      def needs_execute(self):
          target = self.targets[0]
          if target.get_state() == SCons.Node.executing:
              return True
          else:
              if self.top and target.has_builder():
                  display("scons: `%s' is up to date." % str(self.node))
              return False
  
      def execute(self):
          if print_time:
              start_time = time.time()
              global first_command_start
              if first_command_start is None:
                  first_command_start = start_time
          SCons.Taskmaster.Task.execute(self)
          if print_time:
              global cumulative_command_time
              global last_command_end
              finish_time = time.time()
              last_command_end = finish_time
              cumulative_command_time = cumulative_command_time+finish_time-start_time
              sys.stdout.write("Command execution time: %f seconds\n"%(finish_time-start_time))
  
      def do_failed(self, status=2):
          _BuildFailures.append(self.exception[1])
          global exit_status
          global this_build_status
          if self.options.ignore_errors:
              SCons.Taskmaster.Task.executed(self)
          elif self.options.keep_going:
              SCons.Taskmaster.Task.fail_continue(self)
              exit_status = status
              this_build_status = status
          else:
              SCons.Taskmaster.Task.fail_stop(self)
              exit_status = status
              this_build_status = status
              
      def executed(self):
          t = self.targets[0]
          if self.top and not t.has_builder() and not t.side_effect:
              if not t.exists():
                  errstr="Do not know how to make target `%s'." % t
                  sys.stderr.write("scons: *** " + errstr)
                  if not self.options.keep_going:
                      sys.stderr.write("  Stop.")
                  sys.stderr.write("\n")
                  try:
                      raise SCons.Errors.BuildError(t, errstr)
                  except KeyboardInterrupt:
                      raise
                  except:
                      self.exception_set()
                  self.do_failed()
              else:
                  print "scons: Nothing to be done for `%s'." % t
                  SCons.Taskmaster.Task.executed(self)
          else:
              SCons.Taskmaster.Task.executed(self)
  
      def failed(self):
          # Handle the failure of a build task.  The primary purpose here
          # is to display the various types of Errors and Exceptions
          # appropriately.
          exc_info = self.exc_info()
          try:
              t, e, tb = exc_info
          except ValueError:
              t, e = exc_info
              tb = None
  
          if t is None:
              # The Taskmaster didn't record an exception for this Task;
              # see if the sys module has one.
              try:
                  t, e, tb = sys.exc_info()[:]
              except ValueError:
                  t, e = exc_info
                  tb = None
                  
          # Deprecated string exceptions will have their string stored
          # in the first entry of the tuple.
          if e is None:
              e = t
  
          buildError = SCons.Errors.convert_to_BuildError(e)
          if not buildError.node:
              buildError.node = self.node
  
          node = buildError.node
          if not SCons.Util.is_List(node):
                  node = [ node ]
          nodename = string.join(map(str, node), ', ')
  
          errfmt = "scons: *** [%s] %s\n"
          sys.stderr.write(errfmt % (nodename, buildError))
  
          if (buildError.exc_info[2] and buildError.exc_info[1] and 
             # TODO(1.5)
             #not isinstance(
             #    buildError.exc_info[1], 
             #    (EnvironmentError, SCons.Errors.StopError, SCons.Errors.UserError))):
             not isinstance(buildError.exc_info[1], EnvironmentError) and
             not isinstance(buildError.exc_info[1], SCons.Errors.StopError) and
             not isinstance(buildError.exc_info[1], SCons.Errors.UserError)):
              type, value, trace = buildError.exc_info
              traceback.print_exception(type, value, trace)
          elif tb and print_stacktrace:
              sys.stderr.write("scons: internal stack trace:\n")
              traceback.print_tb(tb, file=sys.stderr)
  
          self.exception = (e, buildError, tb) # type, value, traceback
          self.do_failed(buildError.exitstatus)
  
          self.exc_clear()
  
      def postprocess(self):
          if self.top:
              t = self.targets[0]
              for tp in self.options.tree_printers:
                  tp.display(t)
              if self.options.debug_includes:
                  tree = t.render_include_tree()
                  if tree:
                      print
                      print tree
          SCons.Taskmaster.Task.postprocess(self)
  
      def make_ready(self):
          """Make a task ready for execution"""
          SCons.Taskmaster.Task.make_ready(self)
          if self.out_of_date and self.options.debug_explain:
              explanation = self.out_of_date[0].explain()
              if explanation:
                  sys.stdout.write("scons: " + explanation)
  
  class CleanTask(SCons.Taskmaster.Task):
      """An SCons clean task."""
      def fs_delete(self, path, pathstr, remove=1):
          try:
              if os.path.exists(path):
                  if os.path.isfile(path):
                      if remove: os.unlink(path)
                      display("Removed " + pathstr)
                  elif os.path.isdir(path) and not os.path.islink(path):
                      # delete everything in the dir
                      entries = os.listdir(path)
                      # Sort for deterministic output (os.listdir() Can
                      # return entries in a random order).
                      entries.sort()
                      for e in entries:
                          p = os.path.join(path, e)
                          s = os.path.join(pathstr, e)
                          if os.path.isfile(p):
                              if remove: os.unlink(p)
                              display("Removed " + s)
                          else:
                              self.fs_delete(p, s, remove)
                      # then delete dir itself
                      if remove: os.rmdir(path)
                      display("Removed directory " + pathstr)
          except (IOError, OSError), e:
              print "scons: Could not remove '%s':" % pathstr, e.strerror
  
      def show(self):
          target = self.targets[0]
          if (target.has_builder() or target.side_effect) and not target.noclean:
              for t in self.targets:
                  if not t.isdir():
                      display("Removed " + str(t))
          if SCons.Environment.CleanTargets.has_key(target):
              files = SCons.Environment.CleanTargets[target]
              for f in files:
                  self.fs_delete(f.abspath, str(f), 0)
  
      def remove(self):
          target = self.targets[0]
          if (target.has_builder() or target.side_effect) and not target.noclean:
              for t in self.targets:
                  try:
                      removed = t.remove()
                  except OSError, e:
                      # An OSError may indicate something like a permissions
                      # issue, an IOError would indicate something like
                      # the file not existing.  In either case, print a
                      # message and keep going to try to remove as many
                      # targets aa possible.
                      print "scons: Could not remove '%s':" % str(t), e.strerror
                  else:
                      if removed:
                          display("Removed " + str(t))
          if SCons.Environment.CleanTargets.has_key(target):
              files = SCons.Environment.CleanTargets[target]
              for f in files:
                  self.fs_delete(f.abspath, str(f))
  
      execute = remove
  
      # We want the Taskmaster to update the Node states (and therefore
      # handle reference counts, etc.), but we don't want to call
      # back to the Node's post-build methods, which would do things
      # we don't want, like store .sconsign information.
      executed = SCons.Taskmaster.Task.executed_without_callbacks
  
      # Have the taskmaster arrange to "execute" all of the targets, because
      # we'll figure out ourselves (in remove() or show() above) whether
      # anything really needs to be done.
      make_ready = SCons.Taskmaster.Task.make_ready_all
  
      def prepare(self):
          pass
  
  class QuestionTask(SCons.Taskmaster.Task):
      """An SCons task for the -q (question) option."""
      def prepare(self):
          pass
      
      def execute(self):
          if self.targets[0].get_state() != SCons.Node.up_to_date or \
             (self.top and not self.targets[0].exists()):
              global exit_status
              global this_build_status
              exit_status = 1
              this_build_status = 1
              self.tm.stop()
  
      def executed(self):
          pass
  
  
  class TreePrinter:
      def __init__(self, derived=False, prune=False, status=False):
          self.derived = derived
          self.prune = prune
          self.status = status
      def get_all_children(self, node):
          return node.all_children()
      def get_derived_children(self, node):
          children = node.all_children(None)
          return filter(lambda x: x.has_builder(), children)
      def display(self, t):
          if self.derived:
              func = self.get_derived_children
          else:
              func = self.get_all_children
          s = self.status and 2 or 0
          SCons.Util.print_tree(t, func, prune=self.prune, showtags=s)
  
  
  def python_version_string():
      return string.split(sys.version)[0]
  
  def python_version_unsupported(version=sys.version_info):
      return version < (1, 5, 2)
  
  def python_version_deprecated(version=sys.version_info):
      return version < (2, 2, 0)
  
  
  # Global variables
  
  print_objects = 0
  print_memoizer = 0
  print_stacktrace = 0
  print_time = 0
  sconscript_time = 0
  cumulative_command_time = 0
  exit_status = 0 # final exit status, assume success by default
  this_build_status = 0 # "exit status" of an individual build
  num_jobs = None
  delayed_warnings = []
  
  class FakeOptionParser:
      """
      A do-nothing option parser, used for the initial OptionsParser variable.
  
      During normal SCons operation, the OptionsParser is created right
      away by the main() function.  Certain tests scripts however, can
      introspect on different Tool modules, the initialization of which
      can try to add a new, local option to an otherwise uninitialized
      OptionsParser object.  This allows that introspection to happen
      without blowing up.
  
      """
      class FakeOptionValues:
          def __getattr__(self, attr):
              return None
      values = FakeOptionValues()
      def add_local_option(self, *args, **kw):
          pass
  
  OptionsParser = FakeOptionParser()
  
  def AddOption(*args, **kw):
      if not kw.has_key('default'):
          kw['default'] = None
      result = apply(OptionsParser.add_local_option, args, kw)
      return result
  
  def GetOption(name):
      return getattr(OptionsParser.values, name)
  
  def SetOption(name, value):
      return OptionsParser.values.set_option(name, value)
  
  #
  class Stats:
      def __init__(self):
          self.stats = []
          self.labels = []
          self.append = self.do_nothing
          self.print_stats = self.do_nothing
      def enable(self, outfp):
          self.outfp = outfp
          self.append = self.do_append
          self.print_stats = self.do_print
      def do_nothing(self, *args, **kw):
          pass
  
  class CountStats(Stats):
      def do_append(self, label):
          self.labels.append(label)
          self.stats.append(SCons.Debug.fetchLoggedInstances())
      def do_print(self):
          stats_table = {}
          for s in self.stats:
              for n in map(lambda t: t[0], s):
                  stats_table[n] = [0, 0, 0, 0]
          i = 0
          for s in self.stats:
              for n, c in s:
                  stats_table[n][i] = c
              i = i + 1
          keys = stats_table.keys()
          keys.sort()
          self.outfp.write("Object counts:\n")
          pre = ["   "]
          post = ["   %s\n"]
          l = len(self.stats)
          fmt1 = string.join(pre + [' %7s']*l + post, '')
          fmt2 = string.join(pre + [' %7d']*l + post, '')
          labels = self.labels[:l]
          labels.append(("", "Class"))
          self.outfp.write(fmt1 % tuple(map(lambda x: x[0], labels)))
          self.outfp.write(fmt1 % tuple(map(lambda x: x[1], labels)))
          for k in keys:
              r = stats_table[k][:l] + [k]
              self.outfp.write(fmt2 % tuple(r))
  
  count_stats = CountStats()
  
  class MemStats(Stats):
      def do_append(self, label):
          self.labels.append(label)
          self.stats.append(SCons.Debug.memory())
      def do_print(self):
          fmt = 'Memory %-32s %12d\n'
          for label, stats in map(None, self.labels, self.stats):
              self.outfp.write(fmt % (label, stats))
  
  memory_stats = MemStats()
  
  # utility functions
  
  def _scons_syntax_error(e):
      """Handle syntax errors. Print out a message and show where the error
      occurred.
      """
      etype, value, tb = sys.exc_info()
      lines = traceback.format_exception_only(etype, value)
      for line in lines:
          sys.stderr.write(line+'\n')
      sys.exit(2)
  
  def find_deepest_user_frame(tb):
      """
      Find the deepest stack frame that is not part of SCons.
  
      Input is a "pre-processed" stack trace in the form
      returned by traceback.extract_tb() or traceback.extract_stack()
      """
      
      tb.reverse()
  
      # find the deepest traceback frame that is not part
      # of SCons:
      for frame in tb:
          filename = frame[0]
          if string.find(filename, os.sep+'SCons'+os.sep) == -1:
              return frame
      return tb[0]
  
  def _scons_user_error(e):
      """Handle user errors. Print out a message and a description of the
      error, along with the line number and routine where it occured. 
      The file and line number will be the deepest stack frame that is
      not part of SCons itself.
      """
      global print_stacktrace
      etype, value, tb = sys.exc_info()
      if print_stacktrace:
          traceback.print_exception(etype, value, tb)
      filename, lineno, routine, dummy = find_deepest_user_frame(traceback.extract_tb(tb))
      sys.stderr.write("\nscons: *** %s\n" % value)
      sys.stderr.write('File "%s", line %d, in %s\n' % (filename, lineno, routine))
      sys.exit(2)
  
  def _scons_user_warning(e):
      """Handle user warnings. Print out a message and a description of
      the warning, along with the line number and routine where it occured.
      The file and line number will be the deepest stack frame that is
      not part of SCons itself.
      """
      etype, value, tb = sys.exc_info()
      filename, lineno, routine, dummy = find_deepest_user_frame(traceback.extract_tb(tb))
      sys.stderr.write("\nscons: warning: %s\n" % e)
      sys.stderr.write('File "%s", line %d, in %s\n' % (filename, lineno, routine))
  
  def _scons_internal_warning(e):
      """Slightly different from _scons_user_warning in that we use the
      *current call stack* rather than sys.exc_info() to get our stack trace.
      This is used by the warnings framework to print warnings."""
      filename, lineno, routine, dummy = find_deepest_user_frame(traceback.extract_stack())
      sys.stderr.write("\nscons: warning: %s\n" % e[0])
      sys.stderr.write('File "%s", line %d, in %s\n' % (filename, lineno, routine))
  
  def _scons_internal_error():
      """Handle all errors but user errors. Print out a message telling
      the user what to do in this case and print a normal trace.
      """
      print 'internal error'
      traceback.print_exc()
      sys.exit(2)
  
  def _SConstruct_exists(dirname='', repositories=[], filelist=None):
      """This function checks that an SConstruct file exists in a directory.
      If so, it returns the path of the file. By default, it checks the
      current directory.
      """
      if not filelist:
          filelist = ['SConstruct', 'Sconstruct', 'sconstruct']
      for file in filelist:
          sfile = os.path.join(dirname, file)
          if os.path.isfile(sfile):
              return sfile
          if not os.path.isabs(sfile):
              for rep in repositories:
                  if os.path.isfile(os.path.join(rep, sfile)):
                      return sfile
      return None
  
  def _set_debug_values(options):
      global print_memoizer, print_objects, print_stacktrace, print_time
  
      debug_values = options.debug
  
      if "count" in debug_values:
          # All of the object counts are within "if __debug__:" blocks,
          # which get stripped when running optimized (with python -O or
          # from compiled *.pyo files).  Provide a warning if __debug__ is
          # stripped, so it doesn't just look like --debug=count is broken.
          enable_count = False
          if __debug__: enable_count = True
          if enable_count:
              count_stats.enable(sys.stdout)
          else:
              msg = "--debug=count is not supported when running SCons\n" + \
                    "\twith the python -O option or optimized (.pyo) modules."
              SCons.Warnings.warn(SCons.Warnings.NoObjectCountWarning, msg)
      if "dtree" in debug_values:
          options.tree_printers.append(TreePrinter(derived=True))
      options.debug_explain = ("explain" in debug_values)
      if "findlibs" in debug_values:
          SCons.Scanner.Prog.print_find_libs = "findlibs"
      options.debug_includes = ("includes" in debug_values)
      print_memoizer = ("memoizer" in debug_values)
      if "memory" in debug_values:
          memory_stats.enable(sys.stdout)
      print_objects = ("objects" in debug_values)
      if "presub" in debug_values:
          SCons.Action.print_actions_presub = 1
      if "stacktrace" in debug_values:
          print_stacktrace = 1
      if "stree" in debug_values:
          options.tree_printers.append(TreePrinter(status=True))
      if "time" in debug_values:
          print_time = 1
      if "tree" in debug_values:
          options.tree_printers.append(TreePrinter())
  
  def _create_path(plist):
      path = '.'
      for d in plist:
          if os.path.isabs(d):
              path = d
          else:
              path = path + '/' + d
      return path
  
  def _load_site_scons_dir(topdir, site_dir_name=None):
      """Load the site_scons dir under topdir.
      Adds site_scons to sys.path, imports site_scons/site_init.py,
      and adds site_scons/site_tools to default toolpath."""
      if site_dir_name:
          err_if_not_found = True       # user specified: err if missing
      else:
          site_dir_name = "site_scons"
          err_if_not_found = False
          
      site_dir = os.path.join(topdir.path, site_dir_name)
      if not os.path.exists(site_dir):
          if err_if_not_found:
              raise SCons.Errors.UserError, "site dir %s not found."%site_dir
          return
  
      site_init_filename = "site_init.py"
      site_init_modname = "site_init"
      site_tools_dirname = "site_tools"
      sys.path = [os.path.abspath(site_dir)] + sys.path
      site_init_file = os.path.join(site_dir, site_init_filename)
      site_tools_dir = os.path.join(site_dir, site_tools_dirname)
      if os.path.exists(site_init_file):
          import imp
          try:
              fp, pathname, description = imp.find_module(site_init_modname,
                                                          [site_dir])
              try:
                  imp.load_module(site_init_modname, fp, pathname, description)
              finally:
                  if fp:
                      fp.close()
          except ImportError, e:
              sys.stderr.write("Can't import site init file '%s': %s\n"%(site_init_file, e))
              raise
          except Exception, e:
              sys.stderr.write("Site init file '%s' raised exception: %s\n"%(site_init_file, e))
              raise
      if os.path.exists(site_tools_dir):
          SCons.Tool.DefaultToolpath.append(os.path.abspath(site_tools_dir))
  
  def version_string(label, module):
      version = module.__version__
      build = module.__build__
      if build:
          if build[0] != '.':
              build = '.' + build
          version = version + build
      fmt = "\t%s: v%s, %s, by %s on %s\n"
      return fmt % (label,
                    version,
                    module.__date__,
                    module.__developer__,
                    module.__buildsys__)
  
  def _main(parser):
      global exit_status
      global this_build_status
  
      options = parser.values
  
      # Here's where everything really happens.
  
      # First order of business:  set up default warnings and then
      # handle the user's warning options, so that we can issue (or
      # suppress) appropriate warnings about anything that might happen,
      # as configured by the user.
  
      default_warnings = [ SCons.Warnings.CorruptSConsignWarning,
                           SCons.Warnings.DeprecatedWarning,
                           SCons.Warnings.DuplicateEnvironmentWarning,
                           SCons.Warnings.FutureReservedVariableWarning,
                           SCons.Warnings.LinkWarning,
                           SCons.Warnings.MissingSConscriptWarning,
                           SCons.Warnings.NoMD5ModuleWarning,
                           SCons.Warnings.NoMetaclassSupportWarning,
                           SCons.Warnings.NoObjectCountWarning,
                           SCons.Warnings.NoParallelSupportWarning,
                           SCons.Warnings.MisleadingKeywordsWarning,
                           SCons.Warnings.ReservedVariableWarning,
                           SCons.Warnings.StackSizeWarning,
                         ]
  
      for warning in default_warnings:
          SCons.Warnings.enableWarningClass(warning)
      SCons.Warnings._warningOut = _scons_internal_warning
      SCons.Warnings.process_warn_strings(options.warn)
  
      # Now that we have the warnings configuration set up, we can actually
      # issue (or suppress) any warnings about warning-worthy things that
      # occurred while the command-line options were getting parsed.
      try:
          dw = options.delayed_warnings
      except AttributeError:
          pass
      else:
          delayed_warnings.extend(dw)
      for warning_type, message in delayed_warnings:
          SCons.Warnings.warn(warning_type, message)
  
      if options.diskcheck:
          SCons.Node.FS.set_diskcheck(options.diskcheck)
  
      # Next, we want to create the FS object that represents the outside
      # world's file system, as that's central to a lot of initialization.
      # To do this, however, we need to be in the directory from which we
      # want to start everything, which means first handling any relevant
      # options that might cause us to chdir somewhere (-C, -D, -U, -u).
      if options.directory:
          cdir = _create_path(options.directory)
          try:
              os.chdir(cdir)
          except OSError:
              sys.stderr.write("Could not change directory to %s\n" % cdir)
  
      target_top = None
      if options.climb_up:
          target_top = '.'  # directory to prepend to targets
          script_dir = os.getcwd()  # location of script
          while script_dir and not _SConstruct_exists(script_dir,
                                                      options.repository,
                                                      options.file):
              script_dir, last_part = os.path.split(script_dir)
              if last_part:
                  target_top = os.path.join(last_part, target_top)
              else:
                  script_dir = ''
          if script_dir and script_dir != os.getcwd():
              display("scons: Entering directory `%s'" % script_dir)
              os.chdir(script_dir)
  
      # Now that we're in the top-level SConstruct directory, go ahead
      # and initialize the FS object that represents the file system,
      # and make it the build engine default.
      fs = SCons.Node.FS.get_default_fs()
  
      for rep in options.repository:
          fs.Repository(rep)
  
      # Now that we have the FS object, the next order of business is to
      # check for an SConstruct file (or other specified config file).
      # If there isn't one, we can bail before doing any more work.
      scripts = []
      if options.file:
          scripts.extend(options.file)
      if not scripts:
          sfile = _SConstruct_exists(repositories=options.repository,
                                     filelist=options.file)
          if sfile:
              scripts.append(sfile)
  
      if not scripts:
          if options.help:
              # There's no SConstruct, but they specified -h.
              # Give them the options usage now, before we fail
              # trying to read a non-existent SConstruct file.
              raise SConsPrintHelpException
          raise SCons.Errors.UserError, "No SConstruct file found."
  
      if scripts[0] == "-":
          d = fs.getcwd()
      else:
          d = fs.File(scripts[0]).dir
      fs.set_SConstruct_dir(d)
  
      _set_debug_values(options)
      SCons.Node.implicit_cache = options.implicit_cache
      SCons.Node.implicit_deps_changed = options.implicit_deps_changed
      SCons.Node.implicit_deps_unchanged = options.implicit_deps_unchanged
  
      if options.no_exec:
          SCons.SConf.dryrun = 1
          SCons.Action.execute_actions = None
      if options.question:
          SCons.SConf.dryrun = 1
      if options.clean:
          SCons.SConf.SetBuildType('clean')
      if options.help:
          SCons.SConf.SetBuildType('help')
      SCons.SConf.SetCacheMode(options.config)
      SCons.SConf.SetProgressDisplay(progress_display)
  
      if options.no_progress or options.silent:
          progress_display.set_mode(0)
  
      if options.site_dir:
          _load_site_scons_dir(d, options.site_dir)
      elif not options.no_site_dir:
          _load_site_scons_dir(d)
          
      if options.include_dir:
          sys.path = options.include_dir + sys.path
  
      # That should cover (most of) the options.  Next, set up the variables
      # that hold command-line arguments, so the SConscript files that we
      # read and execute have access to them.
      targets = []
      xmit_args = []
      for a in parser.largs:
          if a[0] == '-':
              continue
          if '=' in a:
              xmit_args.append(a)
          else:
              targets.append(a)
      SCons.Script._Add_Targets(targets + parser.rargs)
      SCons.Script._Add_Arguments(xmit_args)
  
      # If stdout is not a tty, replace it with a wrapper object to call flush
      # after every write.
      #
      # Tty devices automatically flush after every newline, so the replacement
      # isn't necessary.  Furthermore, if we replace sys.stdout, the readline
      # module will no longer work.  This affects the behavior during
      # --interactive mode.  --interactive should only be used when stdin and
      # stdout refer to a tty.
      if not sys.stdout.isatty():
          sys.stdout = SCons.Util.Unbuffered(sys.stdout)
      if not sys.stderr.isatty():
          sys.stderr = SCons.Util.Unbuffered(sys.stderr)
  
      memory_stats.append('before reading SConscript files:')
      count_stats.append(('pre-', 'read'))
  
      # And here's where we (finally) read the SConscript files.
  
      progress_display("scons: Reading SConscript files ...")
  
      start_time = time.time()
      try:
          for script in scripts:
              SCons.Script._SConscript._SConscript(fs, script)
      except SCons.Errors.StopError, e:
          # We had problems reading an SConscript file, such as it
          # couldn't be copied in to the VariantDir.  Since we're just
          # reading SConscript files and haven't started building
          # things yet, stop regardless of whether they used -i or -k
          # or anything else.
          sys.stderr.write("scons: *** %s  Stop.\n" % e)
          exit_status = 2
          sys.exit(exit_status)
      global sconscript_time
      sconscript_time = time.time() - start_time
  
      progress_display("scons: done reading SConscript files.")
  
      memory_stats.append('after reading SConscript files:')
      count_stats.append(('post-', 'read'))
  
      # Re-{enable,disable} warnings in case they disabled some in
      # the SConscript file.
      #
      # We delay enabling the PythonVersionWarning class until here so that,
      # if they explicity disabled it in either in the command line or in
      # $SCONSFLAGS, or in the SConscript file, then the search through
      # the list of deprecated warning classes will find that disabling
      # first and not issue the warning.
      SCons.Warnings.enableWarningClass(SCons.Warnings.PythonVersionWarning)
      SCons.Warnings.process_warn_strings(options.warn)
  
      # Now that we've read the SConscript files, we can check for the
      # warning about deprecated Python versions--delayed until here
      # in case they disabled the warning in the SConscript files.
      if python_version_deprecated():
          msg = "Support for pre-2.2 Python (%s) is deprecated.\n" + \
                "    If this will cause hardship, contact dev@scons.tigris.org."
          SCons.Warnings.warn(SCons.Warnings.PythonVersionWarning,
                              msg % python_version_string())
  
      if not options.help:
          SCons.SConf.CreateConfigHBuilder(SCons.Defaults.DefaultEnvironment())
  
      # Now re-parse the command-line options (any to the left of a '--'
      # argument, that is) with any user-defined command-line options that
      # the SConscript files may have added to the parser object.  This will
      # emit the appropriate error message and exit if any unknown option
      # was specified on the command line.
  
      parser.preserve_unknown_options = False
      parser.parse_args(parser.largs, options)
  
      if options.help:
          help_text = SCons.Script.help_text
          if help_text is None:
              # They specified -h, but there was no Help() inside the
              # SConscript files.  Give them the options usage.
              raise SConsPrintHelpException
          else:
              print help_text
              print "Use scons -H for help about command-line options."
          exit_status = 0
          return
  
      # Change directory to the top-level SConstruct directory, then tell
      # the Node.FS subsystem that we're all done reading the SConscript
      # files and calling Repository() and VariantDir() and changing
      # directories and the like, so it can go ahead and start memoizing
      # the string values of file system nodes.
  
      fs.chdir(fs.Top)
  
      SCons.Node.FS.save_strings(1)
  
      # Now that we've read the SConscripts we can set the options
      # that are SConscript settable:
      SCons.Node.implicit_cache = options.implicit_cache
      SCons.Node.FS.set_duplicate(options.duplicate)
      fs.set_max_drift(options.max_drift)
  
      SCons.Job.explicit_stack_size = options.stack_size
  
      if options.md5_chunksize:
          SCons.Node.FS.File.md5_chunksize = options.md5_chunksize
  
      platform = SCons.Platform.platform_module()
  
      if options.interactive:
          SCons.Script.Interactive.interact(fs, OptionsParser, options,
                                            targets, target_top)
  
      else:
  
          # Build the targets
          nodes = _build_targets(fs, options, targets, target_top)
          if not nodes:
              exit_status = 2
  
  def _build_targets(fs, options, targets, target_top):
  
      global this_build_status
      this_build_status = 0
  
      progress_display.set_mode(not (options.no_progress or options.silent))
      display.set_mode(not options.silent)
      SCons.Action.print_actions          = not options.silent
      SCons.Action.execute_actions        = not options.no_exec
      SCons.Node.FS.do_store_info         = not options.no_exec
      SCons.SConf.dryrun                  = options.no_exec
  
      if options.diskcheck:
          SCons.Node.FS.set_diskcheck(options.diskcheck)
  
      SCons.CacheDir.cache_enabled = not options.cache_disable
      SCons.CacheDir.cache_debug = options.cache_debug
      SCons.CacheDir.cache_force = options.cache_force
      SCons.CacheDir.cache_show = options.cache_show
  
      if options.no_exec:
          CleanTask.execute = CleanTask.show
      else:
          CleanTask.execute = CleanTask.remove
  
      lookup_top = None
      if targets or SCons.Script.BUILD_TARGETS != SCons.Script._build_plus_default:
          # They specified targets on the command line or modified
          # BUILD_TARGETS in the SConscript file(s), so if they used -u,
          # -U or -D, we have to look up targets relative to the top,
          # but we build whatever they specified.
          if target_top:
              lookup_top = fs.Dir(target_top)
              target_top = None
  
          targets = SCons.Script.BUILD_TARGETS
      else:
          # There are no targets specified on the command line,
          # so if they used -u, -U or -D, we may have to restrict
          # what actually gets built.
          d = None
          if target_top:
              if options.climb_up == 1:
                  # -u, local directory and below
                  target_top = fs.Dir(target_top)
                  lookup_top = target_top
              elif options.climb_up == 2:
                  # -D, all Default() targets
                  target_top = None
                  lookup_top = None
              elif options.climb_up == 3:
                  # -U, local SConscript Default() targets
                  target_top = fs.Dir(target_top)
                  def check_dir(x, target_top=target_top):
                      if hasattr(x, 'cwd') and not x.cwd is None:
                          cwd = x.cwd.srcnode()
                          return cwd == target_top
                      else:
                          # x doesn't have a cwd, so it's either not a target,
                          # or not a file, so go ahead and keep it as a default
                          # target and let the engine sort it out:
                          return 1                
                  d = filter(check_dir, SCons.Script.DEFAULT_TARGETS)
                  SCons.Script.DEFAULT_TARGETS[:] = d
                  target_top = None
                  lookup_top = None
  
          targets = SCons.Script._Get_Default_Targets(d, fs)
  
      if not targets:
          sys.stderr.write("scons: *** No targets specified and no Default() targets found.  Stop.\n")
          return None
  
      def Entry(x, ltop=lookup_top, ttop=target_top, fs=fs):
          if isinstance(x, SCons.Node.Node):
              node = x
          else:
              node = None
              # Why would ltop be None? Unfortunately this happens.
              if ltop == None: ltop = ''
              # Curdir becomes important when SCons is called with -u, -C,
              # or similar option that changes directory, and so the paths
              # of targets given on the command line need to be adjusted.
              curdir = os.path.join(os.getcwd(), str(ltop))
              for lookup in SCons.Node.arg2nodes_lookups:
                  node = lookup(x, curdir=curdir)
                  if node != None:
                      break
              if node is None:
                  node = fs.Entry(x, directory=ltop, create=1)
          if ttop and not node.is_under(ttop):
              if isinstance(node, SCons.Node.FS.Dir) and ttop.is_under(node):
                  node = ttop
              else:
                  node = None
          return node
  
      nodes = filter(None, map(Entry, targets))
  
      task_class = BuildTask      # default action is to build targets
      opening_message = "Building targets ..."
      closing_message = "done building targets."
      if options.keep_going:
          failure_message = "done building targets (errors occurred during build)."
      else:
          failure_message = "building terminated because of errors."
      if options.question:
          task_class = QuestionTask
      try:
          if options.clean:
              task_class = CleanTask
              opening_message = "Cleaning targets ..."
              closing_message = "done cleaning targets."
              if options.keep_going:
                  failure_message = "done cleaning targets (errors occurred during clean)."
              else:
                  failure_message = "cleaning terminated because of errors."
      except AttributeError:
          pass
  
      task_class.progress = ProgressObject
  
      if options.random:
          def order(dependencies):
              """Randomize the dependencies."""
              import random
              # This is cribbed from the implementation of
              # random.shuffle() in Python 2.X.
              d = dependencies
              for i in xrange(len(d)-1, 0, -1):
                  j = int(random.random() * (i+1))
                  d[i], d[j] = d[j], d[i]
              return d
      else:
          def order(dependencies):
              """Leave the order of dependencies alone."""
              return dependencies
  
      if options.taskmastertrace_file == '-':
          tmtrace = sys.stdout
      elif options.taskmastertrace_file:
          tmtrace = open(options.taskmastertrace_file, 'wb')
      else:
          tmtrace = None
      taskmaster = SCons.Taskmaster.Taskmaster(nodes, task_class, order, tmtrace)
  
      # Let the BuildTask objects get at the options to respond to the
      # various print_* settings, tree_printer list, etc.
      BuildTask.options = options
  
      global num_jobs
      num_jobs = options.num_jobs
      jobs = SCons.Job.Jobs(num_jobs, taskmaster)
      if num_jobs > 1:
          msg = None
          if jobs.num_jobs == 1:
              msg = "parallel builds are unsupported by this version of Python;\n" + \
                    "\tignoring -j or num_jobs option.\n"
          elif sys.platform == 'win32':
              msg = fetch_win32_parallel_msg()
          if msg:
              SCons.Warnings.warn(SCons.Warnings.NoParallelSupportWarning, msg)
  
      memory_stats.append('before building targets:')
      count_stats.append(('pre-', 'build'))
  
      def jobs_postfunc(
          jobs=jobs,
          options=options,
          closing_message=closing_message,
          failure_message=failure_message
          ):
          if jobs.were_interrupted():
              progress_display("scons: Build interrupted.")
              global exit_status
              global this_build_status
              exit_status = 2
              this_build_status = 2
  
          if this_build_status:
              progress_display("scons: " + failure_message)
          else:
              progress_display("scons: " + closing_message)
          if not options.no_exec:
              if jobs.were_interrupted():
                  progress_display("scons: writing .sconsign file.")
              SCons.SConsign.write()
  
      progress_display("scons: " + opening_message)
      jobs.run(postfunc = jobs_postfunc)
  
      memory_stats.append('after building targets:')
      count_stats.append(('post-', 'build'))
  
      return nodes
  
  def _exec_main(parser, values):
      sconsflags = os.environ.get('SCONSFLAGS', '')
      all_args = string.split(sconsflags) + sys.argv[1:]
  
      options, args = parser.parse_args(all_args, values)
  
      if type(options.debug) == type([]) and "pdb" in options.debug:
          import pdb
          pdb.Pdb().runcall(_main, parser)
      elif options.profile_file:
          try:
              from cProfile import Profile
          except ImportError, e:
              from profile import Profile
  
          # Some versions of Python 2.4 shipped a profiler that had the
          # wrong 'c_exception' entry in its dispatch table.  Make sure
          # we have the right one.  (This may put an unnecessary entry
          # in the table in earlier versions of Python, but its presence
          # shouldn't hurt anything).
          try:
              dispatch = Profile.dispatch
          except AttributeError:
              pass
          else:
              dispatch['c_exception'] = Profile.trace_dispatch_return
  
          prof = Profile()
          try:
              prof.runcall(_main, parser)
          except SConsPrintHelpException, e:
              prof.dump_stats(options.profile_file)
              raise e
          except SystemExit:
              pass
          prof.dump_stats(options.profile_file)
      else:
          _main(parser)
  
  def main():
      global OptionsParser
      global exit_status
      global first_command_start
  
      # Check up front for a Python version we do not support.  We
      # delay the check for deprecated Python versions until later,
      # after the SConscript files have been read, in case they
      # disable that warning.
      if python_version_unsupported():
          msg = "scons: *** SCons version %s does not run under Python version %s.\n"
          sys.stderr.write(msg % (SCons.__version__, python_version_string()))
          sys.exit(1)
  
      parts = ["SCons by Steven Knight et al.:\n"]
      try:
          import __main__
          parts.append(version_string("script", __main__))
      except (ImportError, AttributeError):
          # On Windows there is no scons.py, so there is no
          # __main__.__version__, hence there is no script version.
          pass 
      parts.append(version_string("engine", SCons))
      parts.append("Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 The SCons Foundation")
      version = string.join(parts, '')
  
      import SConsOptions
      parser = SConsOptions.Parser(version)
      values = SConsOptions.SConsValues(parser.get_default_values())
  
      OptionsParser = parser
      
      try:
          _exec_main(parser, values)
      except SystemExit, s:
          if s:
              exit_status = s
      except KeyboardInterrupt:
          print("scons: Build interrupted.")
          sys.exit(2)
      except SyntaxError, e:
          _scons_syntax_error(e)
      except SCons.Errors.InternalError:
          _scons_internal_error()
      except SCons.Errors.UserError, e:
          _scons_user_error(e)
      except SConsPrintHelpException:
          parser.print_help()
          exit_status = 0
      except SCons.Errors.BuildError, e:
          exit_status = e.exitstatus
      except:
          # An exception here is likely a builtin Python exception Python
          # code in an SConscript file.  Show them precisely what the
          # problem was and where it happened.
          SCons.Script._SConscript.SConscript_exception()
          sys.exit(2)
  
      memory_stats.print_stats()
      count_stats.print_stats()
  
      if print_objects:
          SCons.Debug.listLoggedInstances('*')
          #SCons.Debug.dumpLoggedInstances('*')
  
      if print_memoizer:
          SCons.Memoize.Dump("Memoizer (memory cache) hits and misses:")
  
      # Dump any development debug info that may have been enabled.
      # These are purely for internal debugging during development, so
      # there's no need to control them with --debug= options; they're
      # controlled by changing the source code.
      SCons.Debug.dump_caller_counts()
      SCons.Taskmaster.dump_stats()
  
      if print_time:
          total_time = time.time() - SCons.Script.start_time
          if num_jobs == 1:
              ct = cumulative_command_time
          else:
              if last_command_end is None or first_command_start is None:
                  ct = 0.0
              else:
                  ct = last_command_end - first_command_start
          scons_time = total_time - sconscript_time - ct
          print "Total build time: %f seconds"%total_time
          print "Total SConscript file execution time: %f seconds"%sconscript_time
          print "Total SCons execution time: %f seconds"%scons_time
          print "Total command execution time: %f seconds"%ct
  
      sys.exit(exit_status)
  