SCons: How can I attach a listener?

Question

I need to attach to the SCons build in order to be notified when things happened during it: file compilation, files linkage, etc.

I know similar is possible for ANT builds via -listener option. Could you please tell how to do it for SCons builds?

Answer 1

When targets are built in SCons, you can associate a post action via the AddPostAction(target, action) function as documented here.

Here is a simple example with a python function action:

# Create yourAction here:
#   can be a python function or external (shell) command line

def helloWorldAction(target = None, source = None, env = None):
    '''
      target: a Node object representing the target file
      source: a Node object representing the source file
      env: the construction environment used for building the target file
      The target and source arguments may be lists of Node objects if there 
      is more than one target file or source file.
    '''

    print "PostAction for target: %s" % str(target)

    # you can get a map of the source files like this:
    # source_file_names = map(lambda x: str(x), source)
    # compilation options, etc can be retrieved from the env

    return 0

env = Environment()
progTarget = env.Program(target = "helloWorld", source = "helloWorld.cc")
env.AddPostAction(progTarget, helloWorldAction)
# Or create the action object like this:
# a = Action(helloWorldAction)

Then, each time helloWorld is built, the helloWorldAction python function will be executed afterwords.

Regarding doing this without modifying the given SConstruct, I dont see how that would be possible.