#! /usr/bin/env python
# encoding: utf-8
# Thomas Nagy, 2006-2010 (ita)

"""
Add a pre-build hook to remove all build files
which do not have a corresponding target

This can be used for example to remove the targets
that have changed name without performing
a full 'waf clean'

Of course, it will only work if there are no dynamically generated
nodes/tasks, in which case the method will have to be modified
to exclude some folders for example.
"""

VERSION='0.0.1'
APPNAME='cc_test'

top = '.'

def options(opt):
	opt.load('compiler_c')
	opt.load('gnu_dirs')

def configure(conf):
	conf.load('compiler_c')

def build(bld):
	import random
	if random.randint(0, 1):
		bld(rule='touch ${TGT}', target='foo.h')
	else:
		bld(rule='touch ${TGT}', target='bar.h')

from waflib import Logs
from waflib.Runner import Parallel
old = Parallel.refill_task_list
def refill_task_list(self):
	iit = old(self)
	bld = self.bld
	if bld.options.targets and bld.options.targets != '*':
		return iit

	# execute only once
	if getattr(self, 'clean', False):
		return iit
	self.clean = True

	# obtain the nodes to use during the build
	nodes = []
	for i in range(len(bld.groups)):
		tasks = bld.get_tasks_group(i)
		for x in tasks:
			try:
				nodes.extend(x.outputs)
			except:
				pass

	# recursion over the nodes to find the stale files
	def iter(node):
		if getattr(node, 'children', []):
			for x in node.children.values():
				iter(x)
		else:
			if not node in nodes:
				Logs.warn("stale file found -> %s" % node.abspath())
				node.delete()
	iter(bld.bldnode)
	return iit

Parallel.refill_task_list = refill_task_list