1#!/usr/bin/env python
2# Copyright (c) 2012 The Chromium Authors. All rights reserved.
3# Use of this source code is governed by a BSD-style license that can be
4# found in the LICENSE file.
5
6"""Formats as a .C file for compilation.
7"""
8
9import os
10import re
11import types
12
13from grit import util
14
15
16def _FormatHeader(root, output_dir):
17  """Returns the required preamble for C files."""
18  # Find the location of the resource header file, so that we can include
19  # it.
20  resource_header = 'resource.h'  # fall back to this
21  for output in root.GetOutputFiles():
22    if output.attrs['type'] == 'rc_header':
23      resource_header = os.path.abspath(output.GetOutputFilename())
24      resource_header = util.MakeRelativePath(output_dir, resource_header)
25  return """// This file is automatically generated by GRIT.  Do not edit.
26
27#include "%s"
28
29// All strings are UTF-8
30""" % (resource_header)
31# end _FormatHeader() function
32
33
34def Format(root, lang='en', output_dir='.'):
35  """Outputs a C switch statement representing the string table."""
36  from grit.node import message
37  assert isinstance(lang, types.StringTypes)
38
39  yield _FormatHeader(root, output_dir)
40
41  yield 'const char* GetString(int id) {\n  switch (id) {'
42
43  for item in root.ActiveDescendants():
44    with item:
45      if isinstance(item, message.MessageNode):
46        yield _FormatMessage(item, lang)
47
48  yield '\n    default:\n      return 0;\n  }\n}'
49
50
51def _HexToOct(match):
52  "Return the octal form of the hex numbers"
53  hex = match.group("hex")
54  result = ""
55  while len(hex):
56    next_num = int(hex[2:4], 16)
57    result += "\\" + '%03d' % int(oct(next_num), 10)
58    hex = hex[4:]
59  return match.group("escaped_backslashes") + result
60
61
62def _FormatMessage(item, lang):
63  """Format a single <message> element."""
64
65  message = item.ws_at_start + item.Translate(lang) + item.ws_at_end
66  # output message with non-ascii chars escaped as octal numbers
67  # C's grammar allows escaped hexadecimal numbers to be infinite,
68  # but octal is always of the form \OOO
69  message = message.encode('utf-8').encode('string_escape')
70  # an escaped char is (\xHH)+ but only if the initial
71  # backslash is not escaped.
72  not_a_backslash = r"(^|[^\\])"  # beginning of line or a non-backslash char
73  escaped_backslashes = not_a_backslash + r"(\\\\)*"
74  hex_digits = r"((\\x)[0-9a-f]{2})+"
75  two_digit_hex_num = re.compile(
76    r"(?P<escaped_backslashes>%s)(?P<hex>%s)"
77    % (escaped_backslashes, hex_digits))
78  message = two_digit_hex_num.sub(_HexToOct, message)
79  # unescape \ (convert \\ back to \)
80  message = message.replace('\\\\', '\\')
81  message = message.replace('"', '\\"')
82  message = util.LINEBREAKS.sub(r'\\n', message)
83
84  name_attr = item.GetTextualIds()[0]
85
86  return '\n    case %s:\n      return "%s";' % (name_attr, message)
87