#!/usr/bin/python
# -*- coding: utf-8 -*-
# Tool to embed file into objects

__author__ = __maintainer__ = "Jérôme Carretero <cJ-waf@zougloub.eu>"
__copyright__ = "Jérôme Carretero, 2014"

"""

This tool allows to embed file contents in object files (.o).
It is not exactly portable, and the file contents are reachable
using various non-portable fashions.
The goal here is to provide a functional interface to the embedding
of file data in objects.
See the ``playground/embedded_resources`` example for an example.

Usage::

   bld(
    name='pipeline',
     # ^ Reference this in use="..." for things using the generated code
    features='file_to_object',
    source='some.file',
     # ^ Name of the file to embed in binary section.
   )

Known issues:

- Currently only handles elf files with GNU ld.

- Destination is named like source, with extension renamed to .o
  eg. some.file -> some.o

"""

import os

from waflib import Task, Utils, TaskGen, Errors

class file_to_object(Task.Task):
	color = 'CYAN'
	dep_vars = ('DEST_CPU', 'DEST_BINFMT')

	def run(self):
		name = []
		for i, x in enumerate(self.inputs[0].name):
			if x.isalnum():
				name.append(x)
			else:
				name.append('_')
		file = self.inputs[0].abspath()
		size = os.path.getsize(file)
		if self.env.DEST_CPU in ('x86_64', 'ia', 'aarch64'):
			unit = 'quad'
			align = 8
		elif self.env.DEST_CPU in ('x86','arm', 'thumb', 'm68k'):
			unit = 'long'
			align = 4
		else:
			raise Errors.WafError("Unsupported DEST_CPU, please report bug!")

		name = "_binary_" + "".join(name)
		rodata = ".section .rodata"
		if self.env.DEST_BINFMT == "mac-o":
			name = "_" + name
			rodata = ".section __TEXT,__const"

		with open(self.outputs[0].abspath(), 'w') as f:
			f.write(\
"""
	.global %(name)s_start
	.global %(name)s_end
	.global %(name)s_size
	%(rodata)s
%(name)s_start:
	.incbin "%(file)s"
%(name)s_end:
	.align %(align)d
%(name)s_size:
	.%(unit)s 0x%(size)x
""" % locals())

@TaskGen.feature('file_to_object')
@TaskGen.before_method('process_source')
def tg_file_to_object(self):
	bld = self.bld
	src = self.to_nodes(self.source)
	assert len(src) == 1
	src = src[0]
	tgt = src.change_ext('-wrap.S')
	task = self.create_task('file_to_object',
	 src, tgt, cwd=src.parent.abspath())
	self.source = [tgt]

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