text: """SCons.Tool.m4
  
  Tool-specific initialization for m4.
  
  There normally shouldn't be any need to import this module directly.
  It will usually be imported through the generic SCons.Tool.Tool()
  selection method.
  
  """
  
  #
  # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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/Tool/m4.py 4369 2009/09/19 15:58:29 scons"
  
  import SCons.Action
  import SCons.Builder
  import SCons.Util
  
  def generate(env):
      """Add Builders and construction variables for m4 to an Environment."""
      M4Action = SCons.Action.Action('$M4COM', '$M4COMSTR')
      bld = SCons.Builder.Builder(action = M4Action, src_suffix = '.m4')
  
      env['BUILDERS']['M4'] = bld
  
      # .m4 files might include other files, and it would be pretty hard
      # to write a scanner for it, so let's just cd to the dir of the m4
      # file and run from there.
      # The src_suffix setup is like so: file.c.m4 -> file.c,
      # file.cpp.m4 -> file.cpp etc.
      env['M4']      = 'm4'
      env['M4FLAGS'] = SCons.Util.CLVar('-E')
      env['M4COM']   = 'cd ${SOURCE.rsrcdir} && $M4 $M4FLAGS < ${SOURCE.file} > ${TARGET.abspath}'
  
  def exists(env):
      return env.Detect('m4')
  
  # Local Variables:
  # tab-width:4
  # indent-tabs-mode:nil
  # End:
  # vim: set expandtab tabstop=4 shiftwidth=4:
  