1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
|
# -*- coding: utf-8 -*-
#
# QAPI schema parser
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013-2019 Red Hat Inc.
#
# Authors:
# Anthony Liguori <aliguori@us.ibm.com>
# Markus Armbruster <armbru@redhat.com>
# Marc-André Lureau <marcandre.lureau@redhat.com>
# Kevin Wolf <kwolf@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.
# See the COPYING file in the top-level directory.
from collections import OrderedDict
import os
import re
from typing import (
TYPE_CHECKING,
Dict,
List,
Mapping,
Optional,
Set,
Union,
)
from .common import must_match
from .error import QAPISemError, QAPISourceError
from .source import QAPISourceInfo
if TYPE_CHECKING:
# pylint: disable=cyclic-import
# TODO: Remove cycle. [schema -> expr -> parser -> schema]
from .schema import QAPISchemaFeature, QAPISchemaMember
# Return value alias for get_expr().
_ExprValue = Union[List[object], Dict[str, object], str, bool]
class QAPIExpression(Dict[str, object]):
# pylint: disable=too-few-public-methods
def __init__(self,
data: Mapping[str, object],
info: QAPISourceInfo,
doc: Optional['QAPIDoc'] = None):
super().__init__(data)
self.info = info
self.doc: Optional['QAPIDoc'] = doc
class QAPIParseError(QAPISourceError):
"""Error class for all QAPI schema parsing errors."""
def __init__(self, parser: 'QAPISchemaParser', msg: str):
col = 1
for ch in parser.src[parser.line_pos:parser.pos]:
if ch == '\t':
col = (col + 7) % 8 + 1
else:
col += 1
super().__init__(parser.info, msg, col)
class QAPISchemaParser:
"""
Parse QAPI schema source.
Parse a JSON-esque schema file and process directives. See
qapi-code-gen.txt section "Schema Syntax" for the exact syntax.
Grammatical validation is handled later by `expr.check_exprs()`.
:param fname: Source file name.
:param previously_included:
The absolute names of previously included source files,
if being invoked from another parser.
:param incl_info:
`QAPISourceInfo` belonging to the parent module.
``None`` implies this is the root module.
:ivar exprs: Resulting parsed expressions.
:ivar docs: Resulting parsed documentation blocks.
:raise OSError: For problems reading the root schema document.
:raise QAPIError: For errors in the schema source.
"""
def __init__(self,
fname: str,
previously_included: Optional[Set[str]] = None,
incl_info: Optional[QAPISourceInfo] = None):
self._fname = fname
self._included = previously_included or set()
self._included.add(os.path.abspath(self._fname))
self.src = ''
# Lexer state (see `accept` for details):
self.info = QAPISourceInfo(self._fname, incl_info)
self.tok: Union[None, str] = None
self.pos = 0
self.cursor = 0
self.val: Optional[Union[bool, str]] = None
self.line_pos = 0
# Parser output:
self.exprs: List[QAPIExpression] = []
self.docs: List[QAPIDoc] = []
# Showtime!
self._parse()
def _parse(self) -> None:
"""
Parse the QAPI schema document.
:return: None. Results are stored in ``.exprs`` and ``.docs``.
"""
cur_doc = None
# May raise OSError; allow the caller to handle it.
with open(self._fname, 'r', encoding='utf-8') as fp:
self.src = fp.read()
if self.src == '' or self.src[-1] != '\n':
self.src += '\n'
# Prime the lexer:
self.accept()
# Parse until done:
while self.tok is not None:
info = self.info
if self.tok == '#':
self.reject_expr_doc(cur_doc)
for cur_doc in self.get_doc(info):
self.docs.append(cur_doc)
continue
expr = self.get_expr()
if not isinstance(expr, dict):
raise QAPISemError(
info, "top-level expression must be an object")
if 'include' in expr:
self.reject_expr_doc(cur_doc)
if len(expr) != 1:
raise QAPISemError(info, "invalid 'include' directive")
include = expr['include']
if not isinstance(include, str):
raise QAPISemError(info,
"value of 'include' must be a string")
incl_fname = os.path.join(os.path.dirname(self._fname),
include)
self._add_expr(OrderedDict({'include': incl_fname}), info)
exprs_include = self._include(include, info, incl_fname,
self._included)
if exprs_include:
self.exprs.extend(exprs_include.exprs)
self.docs.extend(exprs_include.docs)
elif "pragma" in expr:
self.reject_expr_doc(cur_doc)
if len(expr) != 1:
raise QAPISemError(info, "invalid 'pragma' directive")
pragma = expr['pragma']
if not isinstance(pragma, dict):
raise QAPISemError(
info, "value of 'pragma' must be an object")
for name, value in pragma.items():
self._pragma(name, value, info)
else:
if cur_doc and not cur_doc.symbol:
raise QAPISemError(
cur_doc.info, "definition documentation required")
self._add_expr(expr, info, cur_doc)
cur_doc = None
self.reject_expr_doc(cur_doc)
def _add_expr(self, expr: Mapping[str, object],
info: QAPISourceInfo,
doc: Optional['QAPIDoc'] = None) -> None:
self.exprs.append(QAPIExpression(expr, info, doc))
@staticmethod
def reject_expr_doc(doc: Optional['QAPIDoc']) -> None:
if doc and doc.symbol:
raise QAPISemError(
doc.info,
"documentation for '%s' is not followed by the definition"
% doc.symbol)
@staticmethod
def _include(include: str,
info: QAPISourceInfo,
incl_fname: str,
previously_included: Set[str]
) -> Optional['QAPISchemaParser']:
incl_abs_fname = os.path.abspath(incl_fname)
# catch inclusion cycle
inf: Optional[QAPISourceInfo] = info
while inf:
if incl_abs_fname == os.path.abspath(inf.fname):
raise QAPISemError(info, "inclusion loop for %s" % include)
inf = inf.parent
# skip multiple include of the same file
if incl_abs_fname in previously_included:
return None
try:
return QAPISchemaParser(incl_fname, previously_included, info)
except OSError as err:
raise QAPISemError(
info,
f"can't read include file '{incl_fname}': {err.strerror}"
) from err
@staticmethod
def _pragma(name: str, value: object, info: QAPISourceInfo) -> None:
def check_list_str(name: str, value: object) -> List[str]:
if (not isinstance(value, list) or
any(not isinstance(elt, str) for elt in value)):
raise QAPISemError(
info,
"pragma %s must be a list of strings" % name)
return value
pragma = info.pragma
if name == 'doc-required':
if not isinstance(value, bool):
raise QAPISemError(info,
"pragma 'doc-required' must be boolean")
pragma.doc_required = value
elif name == 'command-name-exceptions':
pragma.command_name_exceptions = check_list_str(name, value)
elif name == 'command-returns-exceptions':
pragma.command_returns_exceptions = check_list_str(name, value)
elif name == 'member-name-exceptions':
pragma.member_name_exceptions = check_list_str(name, value)
else:
raise QAPISemError(info, "unknown pragma '%s'" % name)
def accept(self, skip_comment: bool = True) -> None:
"""
Read and store the next token.
:param skip_comment:
When false, return COMMENT tokens ("#").
This is used when reading documentation blocks.
:return:
None. Several instance attributes are updated instead:
- ``.tok`` represents the token type. See below for values.
- ``.info`` describes the token's source location.
- ``.val`` is the token's value, if any. See below.
- ``.pos`` is the buffer index of the first character of
the token.
* Single-character tokens:
These are "{", "}", ":", ",", "[", and "]".
``.tok`` holds the single character and ``.val`` is None.
* Multi-character tokens:
* COMMENT:
This token is not normally returned by the lexer, but it can
be when ``skip_comment`` is False. ``.tok`` is "#", and
``.val`` is a string including all chars until end-of-line,
including the "#" itself.
* STRING:
``.tok`` is "'", the single quote. ``.val`` contains the
string, excluding the surrounding quotes.
* TRUE and FALSE:
``.tok`` is either "t" or "f", ``.val`` will be the
corresponding bool value.
* EOF:
``.tok`` and ``.val`` will both be None at EOF.
"""
while True:
self.tok = self.src[self.cursor]
self.pos = self.cursor
self.cursor += 1
self.val = None
if self.tok == '#':
if self.src[self.cursor] == '#':
# Start of doc comment
skip_comment = False
self.cursor = self.src.find('\n', self.cursor)
if not skip_comment:
self.val = self.src[self.pos:self.cursor]
return
elif self.tok in '{}:,[]':
return
elif self.tok == "'":
# Note: we accept only printable ASCII
string = ''
esc = False
while True:
ch = self.src[self.cursor]
self.cursor += 1
if ch == '\n':
raise QAPIParseError(self, "missing terminating \"'\"")
if esc:
# Note: we recognize only \\ because we have
# no use for funny characters in strings
if ch != '\\':
raise QAPIParseError(self,
"unknown escape \\%s" % ch)
esc = False
elif ch == '\\':
esc = True
continue
elif ch == "'":
self.val = string
return
if ord(ch) < 32 or ord(ch) >= 127:
raise QAPIParseError(
self, "funny character in string")
string += ch
elif self.src.startswith('true', self.pos):
self.val = True
self.cursor += 3
return
elif self.src.startswith('false', self.pos):
self.val = False
self.cursor += 4
return
elif self.tok == '\n':
if self.cursor == len(self.src):
self.tok = None
return
self.info = self.info.next_line()
self.line_pos = self.cursor
elif not self.tok.isspace():
# Show up to next structural, whitespace or quote
# character
match = must_match('[^[\\]{}:,\\s\']+',
self.src[self.cursor-1:])
raise QAPIParseError(self, "stray '%s'" % match.group(0))
def get_members(self) -> Dict[str, object]:
expr: Dict[str, object] = OrderedDict()
if self.tok == '}':
self.accept()
return expr
if self.tok != "'":
raise QAPIParseError(self, "expected string or '}'")
while True:
key = self.val
assert isinstance(key, str) # Guaranteed by tok == "'"
self.accept()
if self.tok != ':':
raise QAPIParseError(self, "expected ':'")
self.accept()
if key in expr:
raise QAPIParseError(self, "duplicate key '%s'" % key)
expr[key] = self.get_expr()
if self.tok == '}':
self.accept()
return expr
if self.tok != ',':
raise QAPIParseError(self, "expected ',' or '}'")
self.accept()
if self.tok != "'":
raise QAPIParseError(self, "expected string")
def get_values(self) -> List[object]:
expr: List[object] = []
if self.tok == ']':
self.accept()
return expr
if self.tok not in tuple("{['tf"):
raise QAPIParseError(
self, "expected '{', '[', ']', string, or boolean")
while True:
expr.append(self.get_expr())
if self.tok == ']':
self.accept()
return expr
if self.tok != ',':
raise QAPIParseError(self, "expected ',' or ']'")
self.accept()
def get_expr(self) -> _ExprValue:
expr: _ExprValue
if self.tok == '{':
self.accept()
expr = self.get_members()
elif self.tok == '[':
self.accept()
expr = self.get_values()
elif self.tok in tuple("'tf"):
assert isinstance(self.val, (str, bool))
expr = self.val
self.accept()
else:
raise QAPIParseError(
self, "expected '{', '[', string, or boolean")
return expr
def get_doc(self, info: QAPISourceInfo) -> List['QAPIDoc']:
if self.val != '##':
raise QAPIParseError(
self, "junk after '##' at start of documentation comment")
docs = []
cur_doc = QAPIDoc(self, info)
self.accept(False)
while self.tok == '#':
assert isinstance(self.val, str)
if self.val.startswith('##'):
# End of doc comment
if self.val != '##':
raise QAPIParseError(
self,
"junk after '##' at end of documentation comment")
cur_doc.end_comment()
docs.append(cur_doc)
self.accept()
return docs
if self.val.startswith('# ='):
if cur_doc.symbol:
raise QAPIParseError(
self,
"unexpected '=' markup in definition documentation")
if cur_doc.body.text:
cur_doc.end_comment()
docs.append(cur_doc)
cur_doc = QAPIDoc(self, info)
cur_doc.append(self.val)
self.accept(False)
raise QAPIParseError(self, "documentation comment must end with '##'")
class QAPIDoc:
"""
A documentation comment block, either definition or free-form
Definition documentation blocks consist of
* a body section: one line naming the definition, followed by an
overview (any number of lines)
* argument sections: a description of each argument (for commands
and events) or member (for structs, unions and alternates)
* features sections: a description of each feature flag
* additional (non-argument) sections, possibly tagged
Free-form documentation blocks consist only of a body section.
"""
class Section:
# pylint: disable=too-few-public-methods
def __init__(self, parser: QAPISchemaParser,
name: Optional[str] = None):
# parser, for error messages about indentation
self._parser = parser
# optional section name (argument/member or section name)
self.name = name
# section text without section name
self.text = ''
# indentation to strip (None means indeterminate)
self._indent = None if self.name else 0
def append(self, line: str) -> None:
line = line.rstrip()
if line:
indent = must_match(r'\s*', line).end()
if self._indent is None:
# indeterminate indentation
if self.text != '':
# non-blank, non-first line determines indentation
self._indent = indent
elif indent < self._indent:
raise QAPIParseError(
self._parser,
"unexpected de-indent (expected at least %d spaces)" %
self._indent)
line = line[self._indent:]
self.text += line + '\n'
class ArgSection(Section):
def __init__(self, parser: QAPISchemaParser,
name: str):
super().__init__(parser, name)
self.member: Optional['QAPISchemaMember'] = None
def connect(self, member: 'QAPISchemaMember') -> None:
self.member = member
class NullSection(Section):
"""
Immutable dummy section for use at the end of a doc block.
"""
# pylint: disable=too-few-public-methods
def append(self, line: str) -> None:
assert False, "Text appended after end_comment() called."
def __init__(self, parser: QAPISchemaParser, info: QAPISourceInfo):
# self._parser is used to report errors with QAPIParseError. The
# resulting error position depends on the state of the parser.
# It happens to be the beginning of the comment. More or less
# servicable, but action at a distance.
self._parser = parser
self.info = info
self.symbol: Optional[str] = None
self.body = QAPIDoc.Section(parser)
# dicts mapping parameter/feature names to their ArgSection
self.args: Dict[str, QAPIDoc.ArgSection] = OrderedDict()
self.features: Dict[str, QAPIDoc.ArgSection] = OrderedDict()
self.sections: List[QAPIDoc.Section] = []
# the current section
self._section = self.body
self._append_line = self._append_body_line
def has_section(self, name: str) -> bool:
"""Return True if we have a section with this name."""
for i in self.sections:
if i.name == name:
return True
return False
def append(self, line: str) -> None:
"""
Parse a comment line and add it to the documentation.
The way that the line is dealt with depends on which part of
the documentation we're parsing right now:
* The body section: ._append_line is ._append_body_line
* An argument section: ._append_line is ._append_args_line
* A features section: ._append_line is ._append_features_line
* An additional section: ._append_line is ._append_various_line
"""
line = line[1:]
if not line:
self._append_freeform(line)
return
if line[0] != ' ':
raise QAPIParseError(self._parser, "missing space after #")
line = line[1:]
self._append_line(line)
def end_comment(self) -> None:
self._switch_section(QAPIDoc.NullSection(self._parser))
@staticmethod
def _match_at_name_colon(string: str):
return re.match(r'@([^:]*): *', string)
@staticmethod
def _match_section_tag(string: str):
return re.match(r'(Returns|Since|Notes?|Examples?|TODO): *', string)
def _append_body_line(self, line: str) -> None:
"""
Process a line of documentation text in the body section.
If this a symbol line and it is the section's first line, this
is a definition documentation block for that symbol.
If it's a definition documentation block, another symbol line
begins the argument section for the argument named by it, and
a section tag begins an additional section. Start that
section and append the line to it.
Else, append the line to the current section.
"""
# FIXME not nice: things like '# @foo:' and '# @foo: ' aren't
# recognized, and get silently treated as ordinary text
if not self.symbol and not self.body.text and line.startswith('@'):
if not line.endswith(':'):
raise QAPIParseError(self._parser, "line should end with ':'")
self.symbol = line[1:-1]
# Invalid names are not checked here, but the name provided MUST
# match the following definition, which *is* validated in expr.py.
if not self.symbol:
raise QAPIParseError(
self._parser, "name required after '@'")
elif self.symbol:
# This is a definition documentation block
if self._match_at_name_colon(line):
self._append_line = self._append_args_line
self._append_args_line(line)
elif line == 'Features:':
self._append_line = self._append_features_line
elif self._match_section_tag(line):
self._append_line = self._append_various_line
self._append_various_line(line)
else:
self._append_freeform(line)
else:
# This is a free-form documentation block
self._append_freeform(line)
def _append_args_line(self, line: str) -> None:
"""
Process a line of documentation text in an argument section.
A symbol line begins the next argument section, a section tag
section or a non-indented line after a blank line begins an
additional section. Start that section and append the line to
it.
Else, append the line to the current section.
"""
match = self._match_at_name_colon(line)
if match:
line = line[match.end():]
self._start_args_section(match.group(1))
elif self._match_section_tag(line):
self._append_line = self._append_various_line
self._append_various_line(line)
return
elif (self._section.text.endswith('\n\n')
and line and not line[0].isspace()):
if line == 'Features:':
self._append_line = self._append_features_line
else:
self._start_section()
self._append_line = self._append_various_line
self._append_various_line(line)
return
self._append_freeform(line)
def _append_features_line(self, line: str) -> None:
match = self._match_at_name_colon(line)
if match:
line = line[match.end():]
self._start_features_section(match.group(1))
elif self._match_section_tag(line):
self._append_line = self._append_various_line
self._append_various_line(line)
return
elif (self._section.text.endswith('\n\n')
and line and not line[0].isspace()):
self._start_section()
self._append_line = self._append_various_line
self._append_various_line(line)
return
self._append_freeform(line)
def _append_various_line(self, line: str) -> None:
"""
Process a line of documentation text in an additional section.
A symbol line is an error.
A section tag begins an additional section. Start that
section and append the line to it.
Else, append the line to the current section.
"""
match = self._match_at_name_colon(line)
if match:
raise QAPIParseError(self._parser,
"description of '@%s:' follows a section"
% match.group(1))
match = self._match_section_tag(line)
if match:
line = line[match.end():]
self._start_section(match.group(1))
self._append_freeform(line)
def _start_symbol_section(
self,
symbols_dict: Dict[str, 'QAPIDoc.ArgSection'],
name: str) -> None:
# FIXME invalid names other than the empty string aren't flagged
if not name:
raise QAPIParseError(self._parser, "invalid parameter name")
if name in symbols_dict:
raise QAPIParseError(self._parser,
"'%s' parameter name duplicated" % name)
assert not self.sections
new_section = QAPIDoc.ArgSection(self._parser, name)
self._switch_section(new_section)
symbols_dict[name] = new_section
def _start_args_section(self, name: str) -> None:
self._start_symbol_section(self.args, name)
def _start_features_section(self, name: str) -> None:
self._start_symbol_section(self.features, name)
def _start_section(self, name: Optional[str] = None) -> None:
if name in ('Returns', 'Since') and self.has_section(name):
raise QAPIParseError(self._parser,
"duplicated '%s' section" % name)
new_section = QAPIDoc.Section(self._parser, name)
self._switch_section(new_section)
self.sections.append(new_section)
def _switch_section(self, new_section: 'QAPIDoc.Section') -> None:
text = self._section.text = self._section.text.strip('\n')
# Only the 'body' section is allowed to have an empty body.
# All other sections, including anonymous ones, must have text.
if self._section != self.body and not text:
# We do not create anonymous sections unless there is
# something to put in them; this is a parser bug.
assert self._section.name
raise QAPIParseError(
self._parser,
"empty doc section '%s'" % self._section.name)
self._section = new_section
def _append_freeform(self, line: str) -> None:
match = re.match(r'(@\S+:)', line)
if match:
raise QAPIParseError(self._parser,
"'%s' not allowed in free-form documentation"
% match.group(1))
self._section.append(line)
def connect_member(self, member: 'QAPISchemaMember') -> None:
if member.name not in self.args:
# Undocumented TODO outlaw
self.args[member.name] = QAPIDoc.ArgSection(self._parser,
member.name)
self.args[member.name].connect(member)
def connect_feature(self, feature: 'QAPISchemaFeature') -> None:
if feature.name not in self.features:
raise QAPISemError(feature.info,
"feature '%s' lacks documentation"
% feature.name)
self.features[feature.name].connect(feature)
def check_expr(self, expr: QAPIExpression) -> None:
if self.has_section('Returns') and 'command' not in expr:
raise QAPISemError(self.info,
"'Returns:' is only valid for commands")
def check(self) -> None:
def check_args_section(
args: Dict[str, QAPIDoc.ArgSection], what: str
) -> None:
bogus = [name for name, section in args.items()
if not section.member]
if bogus:
raise QAPISemError(
self.info,
"documented %s%s '%s' %s not exist" % (
what,
"s" if len(bogus) > 1 else "",
"', '".join(bogus),
"do" if len(bogus) > 1 else "does"
))
check_args_section(self.args, 'member')
check_args_section(self.features, 'feature')
|