import re
import os

# The regular expression for freeze directives. These are comments with the
# word macfreeze immedeately followed by a colon, followed by a directive,
# followed by argument(s)
#
# The directives supported are
# include - Include a module or file
# exclude - Exclude a module
# optional - Include a module if it is found, but don't complain if it isn't
# path - Add sys.path entries. Relative paths are relative to the source file.
#
# See the macfreeze.py main program for a real live example.
#
DIRECTIVE_RE=r'^\s*#\s*macfreeze:\s*(\S*)\s*(.*)\s*$'
REPROG=re.compile(DIRECTIVE_RE)

def findfreezedirectives(program):
	extra_modules = []
	exclude_modules = []
	optional_modules = []
	extra_path = []
	progdir, filename = os.path.split(program)
	fp = open(program)
	for line in fp.readlines():
		match = REPROG.match(line)
		if match:
			directive = match.group(1)
			argument = match.group(2)
			if directive == 'include':
				extra_modules.append(argument)
			elif directive == 'exclude':
				exclude_modules.append(argument)
			elif directive == 'optional':
				optional_modules.append(argument)
			elif directive == 'path':
				argument = os.path.join(progdir, argument)
				extra_path.append(argument)
			else:
				print '** Unknown directive', line
	return extra_modules, exclude_modules, optional_modules, extra_path
	
