1 #!/usr/bin/env python2
2 """Option_def.py."""
3 from __future__ import print_function
4
5 from typing import List, Dict, Optional, Any
6
7
8 class Option(object):
9 def __init__(self,
10 index,
11 name,
12 short_flag=None,
13 builtin='shopt',
14 default=False,
15 implemented=True,
16 groups=None):
17 # type: (int, str, str, Optional[str], bool, bool, List[str]) -> None
18 self.index = index
19 self.name = name # e.g. 'errexit'
20 self.short_flag = short_flag # 'e' for -e
21
22 if short_flag:
23 self.builtin = 'set'
24 else:
25 # The 'interactive' option is the only one where builtin is None. It has
26 # a cell but you can't change it. Only the shell can.
27 self.builtin = builtin
28
29 self.default = default # default value is True in some cases
30 self.implemented = implemented
31 self.groups = groups or [] # list of groups
32
33 # for optview
34 self.is_parse = name.startswith('parse_') or name == 'expand_aliases'
35 # interactive() is an accessor
36 self.is_exec = implemented and not self.is_parse
37
38
39 class _OptionDef(object):
40 """Description of all shell options.
41
42 Similar to id_kind_def.IdSpec
43 """
44
45 def __init__(self):
46 # type: () -> None
47 self.opts = [] # type: List[Option]
48 self.index = 1 # start with 1
49 self.array_size = -1
50
51 def Add(self, *args, **kwargs):
52 # type: (Any, Any) -> None
53 self.opts.append(Option(self.index, *args, **kwargs))
54 self.index += 1
55
56 def DoneWithImplementedOptions(self):
57 # type: () -> None
58 self.array_size = self.index
59
60
61 # Used by builtin
62 _OTHER_SET_OPTIONS = [
63 # NOTE: set -i and +i is explicitly disallowed. Only osh -i or +i is valid
64 # https://unix.stackexchange.com/questions/339506/can-an-interactive-shell-become-non-interactive-or-vice-versa
65 ('n', 'noexec'),
66 ('x', 'xtrace'),
67 ('v', 'verbose'), # like xtrace, but prints unevaluated commands
68 ('f', 'noglob'),
69 ('C', 'noclobber'),
70
71 # A no-op for modernish.
72 (None, 'posix'),
73 (None, 'vi'),
74 (None, 'emacs'),
75 ]
76
77 # These are RUNTIME strict options. We also have parse time ones like
78 # parse_backslash.
79 _STRICT_OPTION_NAMES = [
80 'strict_argv', # empty argv not allowed
81 'strict_arith', # string to integer conversions, e.g. x=foo; echo $(( x ))
82
83 # No implicit conversions between string and array.
84 # - foo="$@" not allowed because it decays. Should be foo=( "$@" ).
85 # - ${a} not ${a[0]} (not implemented)
86 # sane-array? compare arrays like [[ "$@" == "${a[@]}" ]], which is
87 # incompatible because bash coerces
88 # default: do not allow
89 'strict_array',
90 'strict_control_flow', # break/continue at top level is fatal
91 # 'return $empty' and return "" are NOT accepted
92 'strict_errexit', # errexit can't be disabled in compound commands
93 'strict_nameref', # trap invalid variable names
94 'strict_word_eval', # negative slices, unicode
95 'strict_tilde', # ~nonexistent is an error (like zsh)
96
97 # Not implemented
98 'strict_glob', # glob_.py GlobParser has warnings
99 ]
100
101 # These will break some programs, but the fix should be simple.
102
103 # command_sub_errexit makes 'local foo=$(false)' and echo $(false) fail.
104 # By default, we have mimic bash's undesirable behavior of ignoring
105 # these failures, since ash copied it, and Alpine's abuild relies on it.
106 #
107 # Note that inherit_errexit is a strict option.
108
109 _BASIC_RUNTIME_OPTIONS = [
110 ('simple_word_eval', False), # No splitting; arity isn't data-dependent
111 # Don't reparse program data as globs
112 ('dashglob', True), # do globs return files starting with - ?
113
114 # Turn this off so we can statically parse. Because bash has it off
115 # non-interactively, this shouldn't break much.
116 ('expand_aliases', True),
117
118 # TODO: Should these be in strict mode?
119 # The logic was that strict_errexit improves your bash programs, but these
120 # would lead you to remove error handling. But the same could be said for
121 # strict_array?
122 ('command_sub_errexit', False), # check after command sub
123 ('process_sub_fail', False), # like pipefail, but for <(sort foo.txt)
124 ('xtrace_rich', False), # Hierarchical trace with PIDs
125 ('xtrace_details', True), # Legacy set -x stuff
126
127 # Whether status 141 in pipelines is turned into 0
128 ('sigpipe_status_ok', False),
129
130 # Can procs and shell functions be redefined? On in OSH, off in YSH batch,
131 # on in interactive shell
132 ('redefine_proc_func', True),
133 ]
134
135 # TODO: Add strict_arg_parse? For example, 'trap 1 2 3' shouldn't be
136 # valid, because it has an extra argument. Builtins are inconsistent about
137 # checking this.
138
139 _AGGRESSIVE_RUNTIME_OPTIONS = [
140 ('simple_echo', False), # echo takes 0 or 1 arguments
141 ('simple_eval_builtin', False), # eval takes exactly 1 argument
142
143 # only file tests (no strings), remove [, status 2
144 ('simple_test_builtin', False),
145
146 # TODO: simple_trap
147 ]
148
149 # Stuff that doesn't break too many programs.
150 _BASIC_PARSE_OPTIONS = [
151 'parse_at', # @foo, @array(a, b)
152 'parse_proc', # proc p { ... }
153 'parse_func', # func f(x) { ... }
154 'parse_brace', # cd /bin { ... }
155
156 # bare assignment 'x = 42' is allowed in Hay { } blocks, but disallowed
157 # everywhere else. It's not a command 'x' with arg '='.
158 'parse_equals',
159 'parse_paren', # if (x > 0) ...
160 'parse_raw_string', # echo r'\'
161 'parse_triple_quote', # for ''' and """
162 ]
163
164 # Extra stuff that breaks too many programs.
165 _AGGRESSIVE_PARSE_OPTIONS = [
166 ('parse_at_all', False), # @ starting any word, e.g. @[] @{} @@ @_ @-
167
168 # Legacy syntax that is removed. These options are distinct from strict_*
169 # because they don't help you avoid bugs in bash programs. They just makes
170 # the language more consistent.
171 ('parse_backslash', True),
172 ('parse_backticks', True),
173 ('parse_dollar', True),
174 ('parse_ignored', True),
175 ('parse_sh_arith', True), # disallow all shell arithmetic, $(( )) etc.
176 ('parse_dparen', True), # disallow bash's ((
177 ('parse_bare_word', True), # 'case bare' and 'for x in bare'
178 ]
179
180 # No-ops for bash compatibility
181 _NO_OPS = [
182 'lastpipe', # this feature is always on
183
184 # Handled one by one
185 'progcomp',
186 'histappend', # stubbed out for issue #218
187 'hostcomplete', # complete words with '@' ?
188 'cmdhist', # multi-line commands in history
189
190 # Copied from https://www.gnu.org/software/bash/manual/bash.txt
191 # except 'compat*' because they were deemed too ugly
192 'assoc_expand_once',
193 'autocd',
194 'cdable_vars',
195 'cdspell',
196 'checkhash',
197 'checkjobs',
198 'checkwinsize',
199 'complete_fullquote', # Set by default
200 # If set, Bash quotes all shell metacharacters in filenames and
201 # directory names when performing completion. If not set, Bash
202 # removes metacharacters such as the dollar sign from the set of
203 # characters that will be quoted in completed filenames when
204 # these metacharacters appear in shell variable references in
205 # words to be completed. This means that dollar signs in
206 # variable names that expand to directories will not be quoted;
207 # however, any dollar signs appearing in filenames will not be
208 # quoted, either. This is active only when bash is using
209 # backslashes to quote completed filenames. This variable is
210 # set by default, which is the default Bash behavior in versions
211 # through 4.2.
212 'direxpand',
213 'dirspell',
214 'dotglob',
215 'execfail',
216 'extdebug', # for --debugger?
217 'extquote',
218 'force_fignore',
219 'globasciiranges',
220 'globstar', # TODO: implement **
221 'gnu_errfmt',
222 'histreedit',
223 'histverify',
224 'huponexit',
225 'interactive_comments',
226 'lithist',
227 'localvar_inherit',
228 'localvar_unset',
229 'login_shell',
230 'mailwarn',
231 'no_empty_cmd_completion',
232 'nocaseglob',
233 'nocasematch',
234 'progcomp_alias',
235 'promptvars',
236 'restricted_shell',
237 'shift_verbose',
238 'sourcepath',
239 'xpg_echo',
240 ]
241
242
243 def _Init(opt_def):
244 # type: (_OptionDef) -> None
245
246 opt_def.Add('errexit',
247 short_flag='e',
248 builtin='set',
249 groups=['ysh:upgrade', 'ysh:all'])
250 opt_def.Add('nounset',
251 short_flag='u',
252 builtin='set',
253 groups=['ysh:upgrade', 'ysh:all'])
254 opt_def.Add('pipefail', builtin='set', groups=['ysh:upgrade', 'ysh:all'])
255
256 opt_def.Add('inherit_errexit', groups=['ysh:upgrade', 'ysh:all'])
257 # Hm is this subsumed by simple_word_eval?
258 opt_def.Add('nullglob', groups=['ysh:upgrade', 'ysh:all'])
259 opt_def.Add('verbose_errexit', groups=['ysh:upgrade', 'ysh:all'])
260
261 # set -o noclobber, etc.
262 for short_flag, name in _OTHER_SET_OPTIONS:
263 opt_def.Add(name, short_flag=short_flag, builtin='set')
264
265 # The only one where builtin=None. Only the shell can change it.
266 opt_def.Add('interactive', builtin=None)
267
268 # bash --norc -c 'set -o' shows this is on by default
269 opt_def.Add('hashall', short_flag='h', builtin='set', default=True)
270
271 #
272 # shopt
273 # (bash uses $BASHOPTS rather than $SHELLOPTS)
274 #
275
276 # shopt options that aren't in any groups.
277 opt_def.Add('failglob')
278 opt_def.Add('extglob')
279
280 # Compatibility
281 opt_def.Add(
282 'eval_unsafe_arith') # recursive parsing and evaluation (ble.sh)
283
284 # For implementing strict_errexit
285 opt_def.Add('_allow_command_sub', default=True)
286 opt_def.Add('_allow_process_sub', default=True)
287
288 # For implementing 'proc'
289 opt_def.Add('dynamic_scope', default=True)
290
291 # On in interactive shell
292 opt_def.Add('redefine_module', default=False)
293
294 # For disabling strict_errexit while running traps. Because we run in the
295 # main loop, the value can be "off". Prefix with _ because it's undocumented
296 # and users shouldn't fiddle with it. We need a stack so this is a
297 # convenient place.
298 opt_def.Add('_running_trap')
299 opt_def.Add('_running_hay')
300
301 # shopt -s strict_arith, etc.
302 for name in _STRICT_OPTION_NAMES:
303 opt_def.Add(name, groups=['strict:all', 'ysh:all'])
304
305 #
306 # Options that enable YSH features
307 #
308
309 for name in _BASIC_PARSE_OPTIONS:
310 opt_def.Add(name, groups=['ysh:upgrade', 'ysh:all'])
311 # shopt -s simple_word_eval, etc.
312 for name, default in _BASIC_RUNTIME_OPTIONS:
313 opt_def.Add(name, default=default, groups=['ysh:upgrade', 'ysh:all'])
314
315 for name, default in _AGGRESSIVE_PARSE_OPTIONS:
316 opt_def.Add(name, default=default, groups=['ysh:all'])
317 for name, default in _AGGRESSIVE_RUNTIME_OPTIONS:
318 opt_def.Add(name, default=default, groups=['ysh:all'])
319
320 # Off by default.
321 opt_def.Add('parse_tea')
322
323 opt_def.DoneWithImplementedOptions()
324
325 # NO_OPS
326
327 # Stubs for shopt -s xpg_echo, etc.
328 for name in _NO_OPS:
329 opt_def.Add(name, implemented=False)
330
331
332 def All():
333 # type: () -> List[Option]
334 """Return a list of options with metadata.
335
336 - Used by osh/builtin_pure.py to construct the arg spec.
337 - Used by frontend/lexer_gen.py to construct the lexer/matcher
338 """
339 return _OPTION_DEF.opts
340
341
342 def ArraySize():
343 # type: () -> int
344 """Unused now, since we use opt_num::ARRAY_SIZE.
345
346 We could get rid of unimplemented options and shrink the array.
347 """
348 return _OPTION_DEF.array_size
349
350
351 def OptionDict():
352 # type: () -> Dict[str, int]
353 """For the slow path in frontend/match.py."""
354 return dict((opt.name, opt.index) for opt in _OPTION_DEF.opts)
355
356
357 def ParseOptNames():
358 # type: () -> List[str]
359 """Used by core/optview*.py."""
360 return [opt.name for opt in _OPTION_DEF.opts if opt.is_parse]
361
362
363 def ExecOptNames():
364 # type: () -> List[str]
365 """Used by core/optview*.py."""
366 return [opt.name for opt in _OPTION_DEF.opts if opt.is_exec]
367
368
369 _OPTION_DEF = _OptionDef()
370
371 _Init(_OPTION_DEF)
372
373 # Sort by name because we print options.
374 # TODO: for MEMBERSHIP queries, we could sort by the most common? errexit
375 # first?
376 _SORTED = sorted(_OPTION_DEF.opts, key=lambda opt: opt.name)
377
378 PARSE_OPTION_NUMS = [opt.index for opt in _SORTED if opt.is_parse]
379
380 # Sorted because 'shopt -o -p' should be sorted, etc.
381 VISIBLE_SHOPT_NUMS = [
382 opt.index for opt in _SORTED if opt.builtin == 'shopt' and opt.implemented
383 ]
384
385 YSH_UPGRADE = [opt.index for opt in _SORTED if 'ysh:upgrade' in opt.groups]
386 YSH_ALL = [opt.index for opt in _SORTED if 'ysh:all' in opt.groups]
387 STRICT_ALL = [opt.index for opt in _SORTED if 'strict:all' in opt.groups]
388 DEFAULT_TRUE = [opt.index for opt in _SORTED if opt.default]
389 #print([opt.name for opt in _SORTED if opt.default])
390
391 META_OPTIONS = ['strict:all', 'ysh:upgrade', 'ysh:all'] # Passed to flag parser
392
393 # For printing option names to stdout. Wrapped by frontend/consts.
394 OPTION_NAMES = dict((opt.index, opt.name) for opt in _SORTED)