blob: b1fc036e1e4253260d07797392d12b750cf796c7 [file] [log] [blame]
# Copyright 2014 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Helper functions useful when writing scripts that are run from GN's
exec_script function."""
import sys
class GNException(Exception):
# Computes ASCII code of an element of encoded Python 2 str / Python 3 bytes.
_Ord = ord if sys.version_info.major < 3 else lambda c: c
def _TranslateToGnChars(s):
for decoded_ch in s.encode('utf-8'): # str in Python 2, bytes in Python 3.
code = _Ord(decoded_ch) # int
if code in (34, 36, 92): # For '"', '$', or '\\'.
yield '\\' + chr(code)
elif 32 <= code < 127:
yield chr(code)
yield '$0x%02X' % code
def ToGNString(value, allow_dicts=True):
"""Returns a stringified GN equivalent of a Python value.
allow_dicts indicates if this function will allow converting dictionaries
to GN scopes. This is only possible at the top level, you can't nest a
GN scope in a list, so this should be set to False for recursive calls."""
if isinstance(value, str) or isinstance(value, unicode):
if value.find('\n') >= 0:
raise GNException("Trying to print a string with a newline in it.")
return '"' + ''.join(_TranslateToGnChars(value)) + '"'
if isinstance(value, list):
return '[ %s ]' % ', '.join(ToGNString(v, False) for v in value)
if isinstance(value, dict):
if not allow_dicts:
raise GNException("Attempting to recursively print a dictionary.")
result = ""
for key in value:
if not isinstance(key, str):
raise GNException("Dictionary key is not a string.")
result += "%s = %s\n" % (key, ToGNString(value[key], False))
return result
if isinstance(value, int):
return str(value)
raise GNException("Unsupported type %s (value %s) when printing to GN." %
(type(value), value))