#!/usr/bin/env python
# encoding: utf-8
# John O'Meara, 2006
# Thomas Nagy 2009

"Bison processing"

import Task
from TaskGen import extension

bison = '${BISON} ${BISONFLAGS} ${SRC[0].abspath()} -o ${TGT[0].name}'
cls = Task.simple_task_type('bison', bison, 'GREEN', ext_in='.yc .y .yy', ext_out='.c .cxx .h .l', before='cxx', shell=False)

@extension(['.y', '.yc', '.yy'])
def big_bison(self, node):
	"""when it becomes complicated (unlike flex), the old recipes work better (cwd)"""
	has_h = '-d' in self.env['BISONFLAGS']

	outs = []
	if node.name.endswith('.yc'):
		outs.append(node.change_ext('.tab.cc'))
		if has_h:
			outs.append(node.change_ext('.tab.hh'))
	else:
		outs.append(node.change_ext('.tab.c'))
		if has_h:
			outs.append(node.change_ext('.tab.h'))

	tsk = self.create_task('bison', node, outs)
	tsk.cwd = node.bld_dir(tsk.env)

	# and the c/cxx file must be compiled too
	self.allnodes.append(outs[0])

def detect(conf):
	bison = conf.find_program('bison', var='BISON', mandatory=True)
	v = conf.env
	v['BISONFLAGS'] = '-d'

