dart-sdk/build/gn_helpers.py
Lasse Reichstein Holst Nielsen 28c784d87b Fix gn helper script to create *valid* strings for settings containing backslashes.
The current script stores some environment variable values as GN declarations.
It replaces `"` inside the value with `\"` because it creates a `"`-delimited
string, but it doesn't replace `\` with `\\` as it rightly should to preserve
the meaning of the original string.
That affects **Windows paths**. If your path ends in `\`, the created "string literal"
will end (or rather, not end) with `\"` and not be valid.
Similarly if it contains `\"` originally, it will become `\\"` and end the string
early.

It's easy to have a path ending in something like `C:\something\something\`,
and you can't compile Dart if you have that.

Change-Id: Iaa3cdf0c8113fe2f09e7eb3ac7435bf770d8b478
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/200641
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Lasse R.H. Nielsen <lrn@google.com>
2021-05-19 12:35:16 +00:00

58 lines
2 KiB
Python

# 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):
pass
# 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)
else:
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))