title: How to compile in two steps using SCons?
body: <p>I will like to compile files in the following steps using SCons:</p>
  
  <p>.c -> .asm(assembly file) -> .o</p>
  
  <p>I tried to define different builders for this.</p>
  
  <p>I managed to do something like:  .asm -> .o and .c -> .o </p>
  
  <p>I don't know how to make SCons aware of the .asm files generated from .c files and then to use the object builder.</p>
  
  <p>Is there any possibility to use current SCons implementation for this ?</p>
  
  <p><strong>EDIT:</strong> This is what I tried :</p>
  
  <p>-> To define two builders: Builder 1 (c_to_asm) is intended to do .c -> .asm step
                             Builder 2 (asm_to_o) is intended to do .asm -> .o . After these two builders are executed for all the files defined in my SConscript I expect the Program builder to create the final executable.</p>
  
  <pre><code>SCons.Tool.createProgBuilder(env)
  
  c_to_asm = SCons.Builder.Builder(action = {},
                                   emitter = {}, 
                                   prefix = '', 
                                   suffix = '.asm',
                                   src_builder = '',
                                   source_scanner = '',
                                   single_source = 1)
  c_to_asm_action = SCons.Action.Action('c to asm command line', 'Executing .c to .asm builder')
  
  c_to_asm.add_action('.c', c_to_asm_action)
  
  
  asm_to_o = SCons.Builder.Builder(action = {},
                                   emitter = {},
                                   prefix = '',
                                   suffix = '.o',
                                   src_builder = ['CTOASM'],
                                   source_scanner = '',
                                   single_source = 1)
  
  asm_to_o_action = SCons.Action.Action('asm to o command line', 'Executing .asm to .o builder...')
  asm_to_o.add_action('.asm', asm_to_o_action)
  
  
  
  
  
  env['BUILDERS']['CTOASM'] = c_to_asm
  env['BUILDERS']['Object'] = asm_to_o
  </code></pre>
  
  <p>I see the execution string for each builder but no command is executed.</p>
  
  <p>I don't know how to establish in which order these builders execute actions and how to trigger this builders. </p>