| # Copyright 2018 Google Inc. All Rights Reserved. |
| # |
| # Licensed under the Apache License, Version 2.0 (the "License"); |
| # you may not use this file except in compliance with the License. |
| # You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| """Allows to use cmd as a shell.""" |
| |
| import re |
| |
| from starboard.tools.toolchain import abstract |
| |
| |
| def _MaybeJoin(shell, command): |
| if isinstance(command, basestring): |
| return command |
| return shell.Join(command) |
| |
| |
| class Shell(abstract.Shell): |
| """Constructs command lines using Cmd syntax.""" |
| |
| def __init__(self, quote=True): |
| # Toggle whether or not to quote command line arguments. |
| self.quote = quote |
| |
| def MaybeQuoteArgument(self, arg): |
| # Rather than attempting to enumerate the bad shell characters, just |
| # whitelist common OK ones and quote anything else. |
| if re.match(r'^[a-zA-Z0-9_=.\\/-]+$', arg): |
| return arg # No quoting necessary. |
| return self.QuoteForRspFile(arg) |
| |
| def QuoteForRspFile(self, arg): |
| """Quote a command line argument. |
| |
| Quote the argument so that it appears as one argument when |
| processed via cmd.exe and parsed by CommandLineToArgvW (as is typical for |
| Windows programs). |
| |
| Args: |
| arg: The argument to quote. |
| |
| Returns: |
| The quoted argument. |
| """ |
| |
| # See http://goo.gl/cuFbX and http://goo.gl/dhPnp including the comment |
| # threads. This is actually the quoting rules for CommandLineToArgvW, not |
| # for the shell, because the shell doesn't do anything in Windows. This |
| # works more or less because most programs (including the compiler, etc.) |
| # use that function to handle command line arguments. |
| |
| # For a literal quote, CommandLineToArgvW requires 2n+1 backslashes |
| # preceding it, and results in n backslashes + the quote. So we substitute |
| # in 2* what we match, +1 more, plus the quote. |
| windows_quoter_regex = re.compile(r'(\\*)"') |
| arg = windows_quoter_regex.sub(lambda mo: 2 * mo.group(1) + '\\"', arg) |
| |
| # %'s also need to be doubled otherwise they're interpreted as batch |
| # positional arguments. Also make sure to escape the % so that they're |
| # passed literally through escaping so they can be singled to just the |
| # original %. Otherwise, trying to pass the literal representation that |
| # looks like an environment variable to the shell (e.g. %PATH%) would fail. |
| arg = arg.replace('%', '%%') |
| |
| # These commands are used in rsp files, so no escaping for the shell (via ^) |
| # is necessary. |
| |
| # Finally, wrap the whole thing in quotes so that the above quote rule |
| # applies and whitespace isn't a word break. |
| return '"' + arg + '"' |
| |
| def Join(self, command): |
| assert not isinstance(command, basestring) |
| if self.quote: |
| return ' '.join(self.MaybeQuoteArgument(argument) for argument in command) |
| else: |
| return ' '.join(command) |
| |
| def And(self, *commands): |
| return ' && '.join(_MaybeJoin(self, command) for command in commands) |
| |
| def Or(self, *commands): |
| return ' || '.join(_MaybeJoin(self, command) for command in commands) |