N3_sub/modules/waf/playground/strip/strip_hack.py

#! /usr/bin/env python

"""
This is a hack; In general two tasks should not provide
the same output nodes (bad abstraction), and this cannot
scale to more than one operation

In this case, the strip task has the same inputs as outputs
so the constraints added by Task.set_file_constraints
to prevent race conditions:

- By setting the input node to be the link task output node
  the strip tasks will run after their link tasks
- By setting the output node to be the link task output node,
  any other task that also uses this output node will wait
  for the strip task to finish too
- By overriding the runnable_status method, the strip task
  will avoid the deadlock and force itself to run only when
  the link task has run
"""

def configure(conf):
	conf.find_program('strip')

from waflib import Task, TaskGen
class strip(Task.Task):
	run_str = '${STRIP} ${SRC}'
	color   = 'BLUE'
	no_errcheck_out = True

	def keyword(self):
		return 'Stripping'

	def runnable_status(self):
		if self in self.run_after:
			self.run_after.remove(self)
		ret = super(strip, self).runnable_status()
		if ret == Task.ASK_LATER:
			return ret

		if self.generator.link_task.hasrun == Task.SUCCESS:
			# ensure that stripping always runs
			# when a binary is written
			return Task.RUN_ME
		return Task.SKIP_ME

@TaskGen.feature('cshlib', 'cxxshlib', 'cprogram', 'cxxprogram', 'fcprogram', 'fcshlib')
@TaskGen.after('apply_link')
def add_strip_task(self):
	if getattr(self, 'link_task', None):
		exe_node = self.link_task.outputs[0]
		# special case: same inputs and outputs for a task
		self.create_task('strip', exe_node, exe_node)