Mercurial > hg
view mercurial/fancyopts.py @ 40626:87a872555e90
revlog: detect incomplete revlog reads
_readsegment() is supposed to return N bytes of revlog revision
data starting at a file offset. Surprisingly, its behavior before
this patch never verified that it actually read and returned N
bytes! Instead, it would perform the read(), then return whatever
data was available. And even more surprisingly, nothing in the
call chain appears to have been validating that it received all
the data it was expecting.
This behavior could lead to partial or incomplete revision chunks
being operated on. This could result in e.g. cached deltas being
applied against incomplete base revisions. The delta application
process would happily perform this operation. Only hash
verification would detect the corruption and save us.
This commit changes the behavior of raw revlog reading to validate
that we actually read() the number of bytes that were requested.
We will raise a more specific error faster, rather than possibly
have it go undetected or manifest later in the call stack, at
delta application or hash verification.
Differential Revision: https://phab.mercurial-scm.org/D5266
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 13 Nov 2018 12:30:59 -0800 |
parents | 39e5e346eba7 |
children | 2372284d9457 |
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# fancyopts.py - better command line parsing # # Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import abc import functools from .i18n import _ from . import ( error, pycompat, ) # Set of flags to not apply boolean negation logic on nevernegate = { # avoid --no-noninteractive 'noninteractive', # These two flags are special because they cause hg to do one # thing and then exit, and so aren't suitable for use in things # like aliases anyway. 'help', 'version', } def _earlyoptarg(arg, shortlist, namelist): """Check if the given arg is a valid unabbreviated option Returns (flag_str, has_embedded_value?, embedded_value, takes_value?) >>> def opt(arg): ... return _earlyoptarg(arg, b'R:q', [b'cwd=', b'debugger']) long form: >>> opt(b'--cwd') ('--cwd', False, '', True) >>> opt(b'--cwd=') ('--cwd', True, '', True) >>> opt(b'--cwd=foo') ('--cwd', True, 'foo', True) >>> opt(b'--debugger') ('--debugger', False, '', False) >>> opt(b'--debugger=') # invalid but parsable ('--debugger', True, '', False) short form: >>> opt(b'-R') ('-R', False, '', True) >>> opt(b'-Rfoo') ('-R', True, 'foo', True) >>> opt(b'-q') ('-q', False, '', False) >>> opt(b'-qfoo') # invalid but parsable ('-q', True, 'foo', False) unknown or invalid: >>> opt(b'--unknown') ('', False, '', False) >>> opt(b'-u') ('', False, '', False) >>> opt(b'-ufoo') ('', False, '', False) >>> opt(b'--') ('', False, '', False) >>> opt(b'-') ('', False, '', False) >>> opt(b'-:') ('', False, '', False) >>> opt(b'-:foo') ('', False, '', False) """ if arg.startswith('--'): flag, eq, val = arg.partition('=') if flag[2:] in namelist: return flag, bool(eq), val, False if flag[2:] + '=' in namelist: return flag, bool(eq), val, True elif arg.startswith('-') and arg != '-' and not arg.startswith('-:'): flag, val = arg[:2], arg[2:] i = shortlist.find(flag[1:]) if i >= 0: return flag, bool(val), val, shortlist.startswith(':', i + 1) return '', False, '', False def earlygetopt(args, shortlist, namelist, gnu=False, keepsep=False): """Parse options like getopt, but ignores unknown options and abbreviated forms If gnu=False, this stops processing options as soon as a non/unknown-option argument is encountered. Otherwise, option and non-option arguments may be intermixed, and unknown-option arguments are taken as non-option. If keepsep=True, '--' won't be removed from the list of arguments left. This is useful for stripping early options from a full command arguments. >>> def get(args, gnu=False, keepsep=False): ... return earlygetopt(args, b'R:q', [b'cwd=', b'debugger'], ... gnu=gnu, keepsep=keepsep) default parsing rules for early options: >>> get([b'x', b'--cwd', b'foo', b'-Rbar', b'-q', b'y'], gnu=True) ([('--cwd', 'foo'), ('-R', 'bar'), ('-q', '')], ['x', 'y']) >>> get([b'x', b'--cwd=foo', b'y', b'-R', b'bar', b'--debugger'], gnu=True) ([('--cwd', 'foo'), ('-R', 'bar'), ('--debugger', '')], ['x', 'y']) >>> get([b'--unknown', b'--cwd=foo', b'--', '--debugger'], gnu=True) ([('--cwd', 'foo')], ['--unknown', '--debugger']) restricted parsing rules (early options must come first): >>> get([b'--cwd', b'foo', b'-Rbar', b'x', b'-q', b'y'], gnu=False) ([('--cwd', 'foo'), ('-R', 'bar')], ['x', '-q', 'y']) >>> get([b'--cwd=foo', b'x', b'y', b'-R', b'bar', b'--debugger'], gnu=False) ([('--cwd', 'foo')], ['x', 'y', '-R', 'bar', '--debugger']) >>> get([b'--unknown', b'--cwd=foo', b'--', '--debugger'], gnu=False) ([], ['--unknown', '--cwd=foo', '--', '--debugger']) stripping early options (without loosing '--'): >>> get([b'x', b'-Rbar', b'--', '--debugger'], gnu=True, keepsep=True)[1] ['x', '--', '--debugger'] last argument: >>> get([b'--cwd']) ([], ['--cwd']) >>> get([b'--cwd=foo']) ([('--cwd', 'foo')], []) >>> get([b'-R']) ([], ['-R']) >>> get([b'-Rbar']) ([('-R', 'bar')], []) >>> get([b'-q']) ([('-q', '')], []) >>> get([b'-q', b'--']) ([('-q', '')], []) '--' may be a value: >>> get([b'-R', b'--', b'x']) ([('-R', '--')], ['x']) >>> get([b'--cwd', b'--', b'x']) ([('--cwd', '--')], ['x']) value passed to bool options: >>> get([b'--debugger=foo', b'x']) ([], ['--debugger=foo', 'x']) >>> get([b'-qfoo', b'x']) ([], ['-qfoo', 'x']) short option isn't separated with '=': >>> get([b'-R=bar']) ([('-R', '=bar')], []) ':' may be in shortlist, but shouldn't be taken as an option letter: >>> get([b'-:', b'y']) ([], ['-:', 'y']) '-' is a valid non-option argument: >>> get([b'-', b'y']) ([], ['-', 'y']) """ parsedopts = [] parsedargs = [] pos = 0 while pos < len(args): arg = args[pos] if arg == '--': pos += not keepsep break flag, hasval, val, takeval = _earlyoptarg(arg, shortlist, namelist) if not hasval and takeval and pos + 1 >= len(args): # missing last argument break if not flag or hasval and not takeval: # non-option argument or -b/--bool=INVALID_VALUE if gnu: parsedargs.append(arg) pos += 1 else: break elif hasval == takeval: # -b/--bool or -s/--str=VALUE parsedopts.append((flag, val)) pos += 1 else: # -s/--str VALUE parsedopts.append((flag, args[pos + 1])) pos += 2 parsedargs.extend(args[pos:]) return parsedopts, parsedargs class customopt(object): """Manage defaults and mutations for any type of opt.""" __metaclass__ = abc.ABCMeta def __init__(self, defaultvalue): self._defaultvalue = defaultvalue def _isboolopt(self): return False def getdefaultvalue(self): """Returns the default value for this opt. Subclasses should override this to return a new value if the value type is mutable.""" return self._defaultvalue @abc.abstractmethod def newstate(self, oldstate, newparam, abort): """Adds newparam to oldstate and returns the new state. On failure, abort can be called with a string error message.""" class _simpleopt(customopt): def _isboolopt(self): return isinstance(self._defaultvalue, (bool, type(None))) def newstate(self, oldstate, newparam, abort): return newparam class _callableopt(customopt): def __init__(self, callablefn): self.callablefn = callablefn super(_callableopt, self).__init__(None) def newstate(self, oldstate, newparam, abort): return self.callablefn(newparam) class _listopt(customopt): def getdefaultvalue(self): return self._defaultvalue[:] def newstate(self, oldstate, newparam, abort): oldstate.append(newparam) return oldstate class _intopt(customopt): def newstate(self, oldstate, newparam, abort): try: return int(newparam) except ValueError: abort(_('expected int')) def _defaultopt(default): """Returns a default opt implementation, given a default value.""" if isinstance(default, customopt): return default elif callable(default): return _callableopt(default) elif isinstance(default, list): return _listopt(default[:]) elif type(default) is type(1): return _intopt(default) else: return _simpleopt(default) def fancyopts(args, options, state, gnu=False, early=False, optaliases=None): """ read args, parse options, and store options in state each option is a tuple of: short option or '' long option default value description option value label(optional) option types include: boolean or none - option sets variable in state to true string - parameter string is stored in state list - parameter string is added to a list integer - parameter strings is stored as int function - call function with parameter customopt - subclass of 'customopt' optaliases is a mapping from a canonical option name to a list of additional long options. This exists for preserving backward compatibility of early options. If we want to use it extensively, please consider moving the functionality to the options table (e.g separate long options by '|'.) non-option args are returned """ if optaliases is None: optaliases = {} namelist = [] shortlist = '' argmap = {} defmap = {} negations = {} alllong = set(o[1] for o in options) for option in options: if len(option) == 5: short, name, default, comment, dummy = option else: short, name, default, comment = option # convert opts to getopt format onames = [name] onames.extend(optaliases.get(name, [])) name = name.replace('-', '_') argmap['-' + short] = name for n in onames: argmap['--' + n] = name defmap[name] = _defaultopt(default) # copy defaults to state state[name] = defmap[name].getdefaultvalue() # does it take a parameter? if not defmap[name]._isboolopt(): if short: short += ':' onames = [n + '=' for n in onames] elif name not in nevernegate: for n in onames: if n.startswith('no-'): insert = n[3:] else: insert = 'no-' + n # backout (as a practical example) has both --commit and # --no-commit options, so we don't want to allow the # negations of those flags. if insert not in alllong: assert ('--' + n) not in negations negations['--' + insert] = '--' + n namelist.append(insert) if short: shortlist += short if name: namelist.extend(onames) # parse arguments if early: parse = functools.partial(earlygetopt, gnu=gnu) elif gnu: parse = pycompat.gnugetoptb else: parse = pycompat.getoptb opts, args = parse(args, shortlist, namelist) # transfer result to state for opt, val in opts: boolval = True negation = negations.get(opt, False) if negation: opt = negation boolval = False name = argmap[opt] obj = defmap[name] if obj._isboolopt(): state[name] = boolval else: def abort(s): raise error.Abort(_('invalid value %r for option %s, %s') % (pycompat.maybebytestr(val), opt, s)) state[name] = defmap[name].newstate(state[name], val, abort) # return unparsed args return args