OILS / osh / word_parse.py View on Github | oils.pub

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1# Copyright 2016 Andy Chu. All rights reserved.
2# Licensed under the Apache License, Version 2.0 (the "License");
3# you may not use this file except in compliance with the License.
4# You may obtain a copy of the License at
5#
6# http://www.apache.org/licenses/LICENSE-2.0
7"""
8word_parse.py - Parse the shell word language.
9
10Hairy example:
11
12 hi$((1 + 2))"$(echo hi)"${var:-__"$(echo default)"__}
13
14Substitutions can be nested, but which inner subs are allowed depends on the
15outer sub. Notes:
16
17lex_mode_e.ShCommand (_ReadUnquotedLeftParts)
18 All subs and quotes are allowed:
19 $v ${v} $() `` $(()) '' "" $'' $"" <() >()
20
21lex_mode_e.DQ (_ReadDoubleQuotedLeftParts)
22 Var, Command, Arith, but no quotes.
23 $v ${v} $() `` $(())
24 No process substitution.
25
26lex_mode_e.Arith
27 Similar to DQ: Var, Command, and Arith sub, but no process sub. bash doesn't
28 allow quotes, but OSH does. We allow ALL FOUR kinds of quotes, because we
29 need those for associative array indexing.
30
31lex_mode_e.VSub_ArgUnquoted
32 Like ShCommand, everything is allowed (even process substitutions), but we
33 stop at }, and space is SIGNIFICANT.
34
35 Example: ${a:- b }
36
37 ${X:-$v} ${X:-${v}} ${X:-$(echo hi)} ${X:-`echo hi`} ${X:-$((1+2))}
38 ${X:-'single'} ${X:-"double"} ${X:-$'\n'} ${X:-<(echo hi)}
39
40lex_mode_e.VSub_ArgDQ
41 In contrast to DQ, VS_ARG_DQ accepts nested "" and $'' and $"", e.g.
42 "${x:-"default"}".
43
44 In contrast, VSub_ArgUnquoted respects single quotes and process
45 substitution.
46
47 It's weird that double quotes are allowed. Space is also significant here,
48 e.g. "${x:-a "b"}".
49"""
50
51from _devbuild.gen import grammar_nt
52from _devbuild.gen.id_kind_asdl import Id, Id_t, Id_str, Kind
53from _devbuild.gen.types_asdl import (lex_mode_t, lex_mode_e)
54from _devbuild.gen.syntax_asdl import (
55 ExprSub,
56 BoolParamBox,
57 Token,
58 SimpleVarSub,
59 loc,
60 source,
61 word,
62 DoubleQuoted,
63 SingleQuoted,
64 BracedVarSub,
65 CommandSub,
66 InitializerWord,
67 InitializerWord_t,
68 bracket_op,
69 bracket_op_t,
70 suffix_op,
71 suffix_op_t,
72 rhs_word,
73 rhs_word_e,
74 rhs_word_t,
75 word_e,
76 word_t,
77 CompoundWord,
78 word_part,
79 word_part_t,
80 y_lhs_e,
81 arith_expr_t,
82 command,
83 expr,
84 expr_e,
85 expr_t,
86 pat_t,
87 ArgList,
88 Proc,
89 Func,
90 Subscript,
91 Attribute,
92 arith_expr,
93 VarDecl,
94 Mutation,
95 word_part_e,
96)
97from core import alloc
98from core.error import p_die
99from mycpp.mylib import log
100from core import pyutil
101from display import ui
102from frontend import consts
103from frontend import lexer
104from frontend import reader
105from osh import tdop
106from osh import arith_parse
107from osh import braces
108from osh import word_
109from osh import word_compile
110from mycpp.mylib import tagswitch
111
112from libc import HAVE_FNM_EXTMATCH
113
114from typing import List, Optional, Tuple, cast
115from typing import TYPE_CHECKING
116if TYPE_CHECKING:
117 from frontend.lexer import Lexer
118 from frontend.parse_lib import ParseContext
119 from frontend.reader import _Reader
120 from osh.cmd_parse import VarChecker
121
122unused1 = log
123unused2 = Id_str
124
125KINDS_THAT_END_WORDS = [Kind.Eof, Kind.WS, Kind.Op, Kind.Right]
126
127
128def _IsValidYshWord(w):
129 # type: (CompoundWord) -> bool
130 """YSH word restriction
131
132 Allowed:
133 'foo' r'foo' --flag r'foo'
134 --flag='foo'
135 --flag="foo"
136 Not allowed:
137 --flag=r'bar' NAME=u'value' # ambiguous
138 --flag=b''' multi '''
139 """
140 parts = w.parts
141 n = len(parts)
142
143 if n != 0 and word_.LiteralId(parts[0]) == Id.Lit_Tilde:
144 # ~bob/src/'dir with spaces' is allowed
145 # ~bob/src/u'dir with spaces' is ambiguous, but allowed for simplicity
146 return True # early return
147
148 ok = True
149 if n >= 2:
150 # spec/ysh-TODO-deprecate - allow ''/usr/* workaround!
151 # note: ""/usr/* not allowed
152 part0 = parts[0]
153 if part0.tag() == word_part_e.SingleQuoted:
154 sq = cast(SingleQuoted, part0)
155 # Make sure $''' is still disallowed
156 if (sq.left.id == Id.Left_SingleQuote and len(sq.sval) == 0):
157 return True
158
159 for part in parts:
160 if part.tag() in (word_part_e.SingleQuoted,
161 word_part_e.DoubleQuoted):
162 ok = False
163
164 # Allow special cases:
165 # --flag='val' NAME='bar'
166 # But NOT
167 # --flag=r'val' NAME=r'val'
168 if not ok:
169 if (n == 2 and word_.LiteralId(parts[0]) == Id.Lit_VarLike):
170 ok = True
171 elif (n == 3 and word_.LiteralId(parts[0]) == Id.Lit_Chars and
172 word_.LiteralId(parts[1]) == Id.Lit_Equals):
173 ok = True
174
175 return ok
176
177
178class WordEmitter(object):
179 """Common interface for [ and [["""
180
181 def __init__(self):
182 # type: () -> None
183 """Empty constructor for mycpp."""
184 pass
185
186 def ReadWord(self, lex_mode):
187 # type: (lex_mode_t) -> word_t
188 raise NotImplementedError()
189
190
191class WordParser(WordEmitter):
192
193 def __init__(self, parse_ctx, lexer, line_reader):
194 # type: (ParseContext, Lexer, _Reader) -> None
195 self.parse_ctx = parse_ctx
196 self.lexer = lexer
197 self.line_reader = line_reader
198 self.arena = line_reader.arena
199
200 self.parse_opts = parse_ctx.parse_opts
201 self.a_parser = tdop.TdopParser(arith_parse.Spec(), self,
202 self.parse_opts)
203 self.Reset()
204
205 def Init(self, lex_mode):
206 # type: (lex_mode_t) -> None
207 """Used to parse arithmetic, see ParseContext."""
208 self.next_lex_mode = lex_mode
209
210 def Reset(self):
211 # type: () -> None
212 """Called by interactive loop."""
213 # For _GetToken()
214 self.cur_token = None # type: Token
215 self.token_kind = Kind.Undefined
216 self.token_type = Id.Undefined_Tok
217
218 self.next_lex_mode = lex_mode_e.ShCommand
219
220 # Boolean mutated by CommandParser via word_.ctx_EmitDocToken. For ### doc
221 # comments
222 self.emit_doc_token = False
223 # Boolean mutated by CommandParser via word_.ctx_Multiline. '...' starts
224 # multiline mode.
225 self.multiline = False
226
227 # For detecting invalid \n\n in multiline mode. Counts what we got
228 # directly from the lexer.
229 self.newline_state = 0
230 # For consolidating \n\n -> \n for the CALLER. This simplifies the parsers
231 # that consume words.
232 self.returned_newline = False
233
234 # For integration with pgen2
235 self.buffered_word = None # type: word_t
236
237 def _GetToken(self):
238 # type: () -> None
239 """Call this when you need to make a decision based on any of:
240
241 self.token_type
242 self.token_kind
243 self.cur_token
244 """
245 if self.next_lex_mode == lex_mode_e.Undefined:
246 return # _SetNext() not called, so do nothing
247
248 is_fake = self.next_lex_mode == lex_mode_e.BashRegexFakeInner
249 real_mode = (lex_mode_e.BashRegex if is_fake else self.next_lex_mode)
250
251 self.cur_token = self.lexer.Read(real_mode)
252
253 # MUTATE TOKEN for fake lexer mode.
254 # This is for crazy stuff bash allows, like [[ s =~ (< >) ]]
255 if (is_fake and self.cur_token.id
256 in (Id.WS_Space, Id.BashRegex_AllowedInParens)):
257 self.cur_token.id = Id.Lit_Chars
258
259 self.token_type = self.cur_token.id
260 self.token_kind = consts.GetKind(self.token_type)
261
262 # number of consecutive newlines, ignoring whitespace
263 if self.token_type == Id.Op_Newline:
264 self.newline_state += 1
265 elif self.token_kind != Kind.WS:
266 self.newline_state = 0
267
268 self.parse_ctx.trail.AppendToken(self.cur_token) # For completion
269 self.next_lex_mode = lex_mode_e.Undefined
270
271 def _SetNext(self, lex_mode):
272 # type: (lex_mode_t) -> None
273 """Set the next lex state, but don't actually read a token.
274
275 We need this for proper interactive parsing.
276 """
277 self.next_lex_mode = lex_mode
278
279 def _ReadVarOpArg(self, arg_lex_mode):
280 # type: (lex_mode_t) -> rhs_word_t
281
282 # NOTE: Operators like | and < are not treated as special, so ${a:- | >} is
283 # valid, even when unquoted.
284 self._SetNext(arg_lex_mode)
285 self._GetToken()
286
287 w = self._ReadVarOpArg2(arg_lex_mode, Id.Undefined_Tok,
288 True) # empty_ok
289
290 # If the Compound has no parts, and we're in a double-quoted VarSub
291 # arg, and empty_ok, then return Empty. This is so it can evaluate to
292 # the empty string and not get elided.
293 #
294 # Examples:
295 # - "${s:-}", "${s/%pat/}"
296 # It's similar to LooksLikeShAssignment where we turn x= into x=''. And it
297 # has the same potential problem of not having Token location info.
298 #
299 # NOTE: empty_ok is False only for the PatSub pattern, which means we'll
300 # return a Compound with no parts, which is explicitly checked with a
301 # custom error message.
302 if len(w.parts) == 0 and arg_lex_mode == lex_mode_e.VSub_ArgDQ:
303 return rhs_word.Empty
304
305 return w
306
307 def _ReadVarOpArg2(self, arg_lex_mode, eof_type, empty_ok):
308 # type: (lex_mode_t, Id_t, bool) -> CompoundWord
309 """Helper function for _ReadVarOpArg and _ReadPatSubVarOp"""
310 w = self._ReadCompoundWord3(arg_lex_mode, eof_type, empty_ok)
311 tilde = word_.TildeDetect(w)
312 if tilde:
313 w = tilde
314 return w
315
316 def _ReadSliceVarOp(self):
317 # type: () -> suffix_op.Slice
318 """
319 Looking token after first ':'
320
321 ArithExpr? (':' ArithExpr? )? '}'
322 """
323 self._NextNonSpace()
324
325 cur_id = self.token_type
326
327 if cur_id in (Id.Arith_RBrace, Id.Arith_Colon): # ${a:} or ${a::}
328 begin = arith_expr.EmptyZero # type: arith_expr_t
329 else:
330 begin = self.a_parser.Parse()
331 cur_id = self.a_parser.CurrentId() # advance
332
333 if cur_id == Id.Arith_RBrace: # ${a:1} or ${@:1}
334 # No length specified, so it's N
335 no_length = None # type: Optional[arith_expr_t]
336 return suffix_op.Slice(begin, no_length)
337
338 elif cur_id == Id.Arith_Colon: # ${a:1:} or ${@:1:}
339 colon_tok = self.cur_token
340 self._NextNonSpace()
341
342 if self.token_type == Id.Arith_RBrace:
343 # quirky bash behavior:
344 # ${a:1:} or ${a::} means length ZERO
345 # but ${a:1} or ${a:} means length N
346 if self.parse_opts.strict_parse_slice():
347 p_die(
348 "Slice length: Add explicit zero, or omit : for N (strict_parse_slice)",
349 colon_tok)
350
351 length = arith_expr.EmptyZero # type: arith_expr_t
352 else:
353 length = self._ReadArithExpr(Id.Arith_RBrace)
354
355 return suffix_op.Slice(begin, length)
356
357 else:
358 p_die("Expected : or } in slice", self.cur_token)
359
360 raise AssertionError() # for MyPy
361
362 def _ReadPatSubVarOp(self):
363 # type: () -> suffix_op.PatSub
364 """Looking at the first '/' after VarOf:
365
366 VarSub = ...
367 | VarOf '/' Match ( '/' WORD? )?
368 Match = '/' WORD # can't be empty
369 | '#' WORD? # may be empty
370 | '%' WORD?
371 """
372 slash_tok = self.cur_token # location info
373 replace_mode = Id.Undefined_Tok # bizarre syntax / # %
374
375 self._SetNext(lex_mode_e.VSub_ArgUnquoted) # advance past /
376
377 self._GetToken()
378 if self.token_type == Id.Right_DollarBrace:
379 pat = CompoundWord([])
380 return suffix_op.PatSub(pat, rhs_word.Empty, replace_mode,
381 slash_tok)
382
383 if self.token_type in (Id.Lit_Slash, Id.Lit_Pound, Id.Lit_Percent):
384 replace_mode = self.token_type
385 self._SetNext(lex_mode_e.VSub_ArgUnquoted)
386
387 # Bash quirk:
388 # echo ${x/#/replace} has an empty pattern
389 # echo ${x////replace} is non-empty; it means echo ${x//'/'/replace}
390 empty_ok = replace_mode != Id.Lit_Slash
391 pat = self._ReadVarOpArg2(lex_mode_e.VSub_ArgUnquoted, Id.Lit_Slash,
392 empty_ok)
393 #log('pat 1 %r', pat)
394
395 if self.token_type == Id.Lit_Slash:
396 # read until }
397 replace = self._ReadVarOpArg(
398 lex_mode_e.VSub_ArgUnquoted) # type: rhs_word_t
399 #log('r 1 %r', replace)
400 else:
401 # e.g. ${v/a} is the same as ${v/a/} -- empty replacement string
402 replace = rhs_word.Empty
403
404 self._GetToken()
405 if self.token_type != Id.Right_DollarBrace:
406 # This happens on invalid code
407 p_die(
408 "Expected } after replacement string, got %s" %
409 ui.PrettyId(self.token_type), self.cur_token)
410
411 return suffix_op.PatSub(pat, replace, replace_mode, slash_tok)
412
413 def _ReadSubscript(self):
414 # type: () -> bracket_op_t
415 """ Subscript = '[' ('@' | '*' | ArithExpr) ']' """
416 # Lookahead to see if we get @ or *. Otherwise read a full arithmetic
417 # expression.
418 next_id = self.lexer.LookPastSpace(lex_mode_e.Arith)
419 if next_id in (Id.Lit_At, Id.Arith_Star):
420 op = bracket_op.WholeArray(next_id) # type: bracket_op_t
421
422 self._SetNext(lex_mode_e.Arith) # skip past [
423 self._GetToken()
424 self._SetNext(lex_mode_e.Arith) # skip past @
425 self._GetToken()
426 else:
427 self._SetNext(lex_mode_e.Arith) # skip past [
428 anode = self._ReadArithExpr(Id.Arith_RBracket)
429 op = bracket_op.ArrayIndex(anode)
430
431 if self.token_type != Id.Arith_RBracket: # Should be looking at ]
432 p_die('Expected ] to close subscript', self.cur_token)
433
434 self._SetNext(lex_mode_e.VSub_2) # skip past ]
435 self._GetToken() # Needed to be in the same spot as no subscript
436
437 return op
438
439 def _ParseVarOf(self):
440 # type: () -> BracedVarSub
441 """
442 VarOf = NAME Subscript?
443 | NUMBER # no subscript allowed, none of these are arrays
444 # ${@[1]} doesn't work, even though slicing does
445 | VarSymbol
446 """
447 self._GetToken()
448 name_token = self.cur_token
449 self._SetNext(lex_mode_e.VSub_2)
450
451 self._GetToken() # Check for []
452 if self.token_type == Id.VOp2_LBracket:
453 bracket_op = self._ReadSubscript()
454 else:
455 bracket_op = None
456
457 part = BracedVarSub.CreateNull()
458 part.name_tok = name_token
459 part.var_name = lexer.TokenVal(name_token)
460 part.bracket_op = bracket_op
461 return part
462
463 def _ParseVarExpr(self, arg_lex_mode, allow_query=False):
464 # type: (lex_mode_t, bool) -> BracedVarSub
465 """Start parsing at the op -- we already skipped past the name."""
466 part = self._ParseVarOf()
467
468 self._GetToken()
469 if self.token_type == Id.Right_DollarBrace:
470 return part # no ops
471
472 op_kind = self.token_kind
473
474 if op_kind == Kind.VTest:
475 tok = self.cur_token
476 arg_word = self._ReadVarOpArg(arg_lex_mode)
477 if self.token_type != Id.Right_DollarBrace:
478 p_die('Expected } to close ${', self.cur_token)
479
480 part.suffix_op = suffix_op.Unary(tok, arg_word)
481
482 elif op_kind == Kind.VOpYsh:
483 tok = self.cur_token
484 arg_word = self._ReadVarOpArg(arg_lex_mode)
485 if self.token_type != Id.Right_DollarBrace:
486 p_die('Expected } to close ${', self.cur_token)
487
488 UP_arg_word = arg_word
489 with tagswitch(arg_word) as case:
490 if case(rhs_word_e.Empty):
491 pass
492 elif case(rhs_word_e.Compound):
493 arg_word = cast(CompoundWord, UP_arg_word)
494 # This handles ${x|html} and ${x %.3f} now
495 # However I think ${x %.3f} should be statically parsed? It can enter
496 # the printf lexer modes.
497 ok, arg, quoted = word_.StaticEval(arg_word)
498 if not ok or quoted:
499 p_die('Expected a constant argument',
500 loc.Word(arg_word))
501
502 part.suffix_op = suffix_op.Static(tok, arg)
503
504 elif op_kind == Kind.VOp0:
505 part.suffix_op = self.cur_token # Nullary
506 self._SetNext(lex_mode_e.VSub_2) # Expecting }
507 self._GetToken()
508
509 elif op_kind == Kind.VOp1: # % %% # ## etc.
510 tok = self.cur_token
511 # Weird exception that all shells have: these operators take a glob
512 # pattern, so they're lexed as VSub_ArgUnquoted, not VSub_ArgDQ
513 arg_word = self._ReadVarOpArg(lex_mode_e.VSub_ArgUnquoted)
514 if self.token_type != Id.Right_DollarBrace:
515 p_die('Expected } to close ${', self.cur_token)
516
517 part.suffix_op = suffix_op.Unary(tok, arg_word)
518
519 elif op_kind == Kind.VOp2: # / : [ ]
520 if self.token_type == Id.VOp2_Slash:
521 patsub_op = self._ReadPatSubVarOp() # type: suffix_op_t
522 part.suffix_op = patsub_op
523
524 # Checked by the method above
525 assert self.token_type == Id.Right_DollarBrace, self.cur_token
526
527 elif self.token_type == Id.VOp2_Colon:
528 part.suffix_op = self._ReadSliceVarOp()
529 # NOTE: } in arithmetic mode.
530 if self.token_type != Id.Arith_RBrace:
531 # Token seems off; doesn't point to X in # ${a:1:2 X
532 p_die('Expected } to close ${', self.cur_token)
533
534 else:
535 # TODO: Does this ever happen?
536 p_die('Unexpected token in ${} (%s)' % 'VOp2', self.cur_token)
537
538 elif op_kind == Kind.VOp3: # ${prefix@} etc.
539 if allow_query:
540 part.suffix_op = self.cur_token # Nullary
541 self._SetNext(lex_mode_e.VSub_2) # Expecting }
542 self._GetToken()
543 else:
544 p_die("Unexpected token in ${} (%s)" % 'VOp3', self.cur_token)
545
546 # NOTE: Arith_RBrace is for slicing, because it reads } in arithmetic
547 # mode. It's redundantly checked above.
548 if self.token_type not in (Id.Right_DollarBrace, Id.Arith_RBrace):
549 # ${a.} or ${!a.}
550 p_die('Expected } to close ${', self.cur_token)
551
552 # Now look for ops
553 return part
554
555 def _ReadZshVarSub(self, left_token):
556 # type: (Token) -> word_part.ZshVarSub
557
558 self._SetNext(lex_mode_e.VSub_Zsh) # Move past ${(foo)
559
560 # Can be empty
561 w = self._ReadCompoundWord3(lex_mode_e.VSub_Zsh, Id.Right_DollarBrace,
562 True)
563 self._GetToken()
564 return word_part.ZshVarSub(left_token, w, self.cur_token)
565
566 def ReadBracedVarSub(self, left_token):
567 # type: (Token) -> Tuple[BracedVarSub, Token]
568 """ For YSH expressions like var x = ${x:-"default"}. """
569 part = self._ReadBracedVarSub(left_token, d_quoted=False)
570 last_token = self.cur_token
571 return part, last_token
572
573 def _ReadBracedVarSub(self, left_token, d_quoted):
574 # type: (Token, bool) -> BracedVarSub
575 """For the ${} expression language.
576
577 NAME = [a-zA-Z_][a-zA-Z0-9_]*
578 NUMBER = [0-9]+ # ${10}, ${11}, ...
579
580 Subscript = '[' ('@' | '*' | ArithExpr) ']'
581 VarSymbol = '!' | '@' | '#' | ...
582 VarOf = NAME Subscript?
583 | NUMBER # no subscript allowed, none of these are arrays
584 # ${@[1]} doesn't work, even though slicing does
585 | VarSymbol
586
587 NULLARY_OP = '@Q' | '@E' | '@P' | '@A' | '@a' # VOp0
588
589 TEST_OP = '-' | ':-' | '=' | ':=' | '+' | ':+' | '?' | ':?'
590 STRIP_OP = '#' | '##' | '%' | '%%'
591 CASE_OP = ',' | ',,' | '^' | '^^'
592 UnaryOp = TEST_OP | STRIP_OP | CASE_OP
593
594 YSH_UNARY = '|' | ' ' # ${x|html} and ${x %.3f}.
595 # SPACE is operator not %
596 Match = ('/' | '#' | '%') WORD # match all / prefix / suffix
597 VarExpr = VarOf
598 | VarOf NULLARY_OP
599 | VarOf UnaryOp WORD
600 | VarOf YSH_UNARY STATIC_WORD
601 | VarOf ':' ArithExpr (':' ArithExpr )?
602 | VarOf '/' Match '/' WORD
603
604 LengthExpr = '#' VarOf # can't apply operators after length
605
606 RefOrKeys = '!' VarExpr # CAN apply operators after a named ref
607 # ${!ref[0]} vs ${!keys[@]} resolved later
608
609 PrefixQuery = '!' NAME ('*' | '@') # list variable names with a prefix
610
611 BuiltinSub = '.' WORD+ # ${.myproc 'builtin' $sub}
612
613 VarSub = LengthExpr
614 | RefOrKeys
615 | PrefixQuery
616 | VarExpr
617 | BuiltinSub
618
619 NOTES:
620 - Arithmetic expressions are used twice, inside subscripts ${a[x+1]} and
621 slicing ${a:x+1:y+2}
622 - ${#} and ${!} need LL(2) lookahead (considering how my tokenizer works)
623 - @ and * are technically arithmetic expressions in this implementation
624 - We don't account for bash 4.4: ${param@operator} -- Q E P A a. Note that
625 it's also vectorized.
626
627 Strictness over bash:
628 - echo ${a[0][0]} doesn't do anything useful, so we disallow it from the
629 grammar
630 - ! and # prefixes can't be composed, even though named refs can be
631 composed with other operators
632 - '#' means 4 different things: length prefix, VarSymbol, UnaryOp to strip
633 a prefix, and it can also be a literal part of WORD.
634
635 From the parser's point of view, the prefix # can't be combined with
636 UnaryOp/slicing/matching, and the ! can. However
637
638 - ${a[@]:1:2} is not allowed
639 - ${#a[@]:1:2} is allowed, but gives the wrong answer
640 """
641 if d_quoted:
642 arg_lex_mode = lex_mode_e.VSub_ArgDQ
643 else:
644 arg_lex_mode = lex_mode_e.VSub_ArgUnquoted
645
646 self._SetNext(lex_mode_e.VSub_1)
647 self._GetToken()
648
649 ty = self.token_type
650 first_tok = self.cur_token
651
652 if ty == Id.VSub_Pound:
653 # Disambiguate
654 next_id = self.lexer.LookPastSpace(lex_mode_e.VSub_1)
655 if next_id not in (Id.Unknown_Tok, Id.Right_DollarBrace):
656 # e.g. a name, '#' is the prefix
657 self._SetNext(lex_mode_e.VSub_1)
658 part = self._ParseVarOf()
659
660 self._GetToken()
661 if self.token_type != Id.Right_DollarBrace:
662 p_die('Expected } after length expression', self.cur_token)
663
664 part.prefix_op = first_tok
665
666 else: # not a prefix, '#' is the variable
667 part = self._ParseVarExpr(arg_lex_mode)
668
669 elif ty == Id.VSub_Bang:
670 next_id = self.lexer.LookPastSpace(lex_mode_e.VSub_1)
671 if next_id not in (Id.Unknown_Tok, Id.Right_DollarBrace):
672 # e.g. a name, '!' is the prefix
673 # ${!a} -- this is a ref
674 # ${!3} -- this is ref
675 # ${!a[1]} -- this is a ref
676 # ${!a[@]} -- this is a keys
677 # No lookahead -- do it in a second step, or at runtime
678 self._SetNext(lex_mode_e.VSub_1)
679 part = self._ParseVarExpr(arg_lex_mode, allow_query=True)
680
681 part.prefix_op = first_tok
682
683 else: # not a prefix, '!' is the variable
684 part = self._ParseVarExpr(arg_lex_mode)
685
686 elif ty == Id.VSub_Dot:
687 # Note: this will become a new builtin_sub type, so this method must
688 # return word_part_t rather than BracedVarSub. I don't think that
689 # should cause problems.
690 p_die('TODO: ${.myproc builtin sub}', self.cur_token)
691
692 # VS_NAME, VS_NUMBER, symbol that isn't # or !
693 elif self.token_kind == Kind.VSub:
694 part = self._ParseVarExpr(arg_lex_mode)
695
696 else:
697 # e.g. ${^}
698 p_die('Unexpected token in ${}', self.cur_token)
699
700 part.left = left_token # attach the argument
701 part.right = self.cur_token
702 return part
703
704 def _ReadSingleQuoted(self, left_token, lex_mode):
705 # type: (Token, lex_mode_t) -> SingleQuoted
706 """Internal method to read a word_part."""
707 tokens = [] # type: List[Token]
708 # In command mode, we never disallow backslashes like '\'
709 right_quote = self.ReadSingleQuoted(lex_mode, left_token, tokens,
710 False)
711 sval = word_compile.EvalSingleQuoted(left_token.id, tokens)
712 node = SingleQuoted(left_token, sval, right_quote)
713 return node
714
715 def ReadSingleQuoted(self, lex_mode, left_token, out_tokens, is_ysh_expr):
716 # type: (lex_mode_t, Token, List[Token], bool) -> Token
717 """Appends to out_tokens; returns last token
718
719 Used by expr_parse.py
720 """
721 if (left_token.id == Id.Left_DollarSingleQuote and
722 self.parse_opts.no_parse_osh()):
723 p_die("Instead of $'', use J8 strings like b'' (no_parse_osh)",
724 left_token)
725
726 # echo '\' is allowed, but x = '\' is invalid, in favor of x = r'\'
727 # enforce for triple-quoted strings: ''' \u ''' requires r''' \u '''
728 no_backslashes = is_ysh_expr and left_token.id in (
729 Id.Left_SingleQuote, Id.Left_TSingleQuote)
730
731 expected_end_tokens = 3 if left_token.id in (
732 Id.Left_TSingleQuote, Id.Left_RTSingleQuote, Id.Left_UTSingleQuote,
733 Id.Left_BTSingleQuote) else 1
734 num_end_tokens = 0
735
736 # TODO: could we directly append to out_tokens?
737 tokens = [] # type: List[Token]
738 while num_end_tokens < expected_end_tokens:
739 self._SetNext(lex_mode)
740 self._GetToken()
741
742 # Kind.Char emitted in lex_mode.SQ_C
743 if self.token_kind in (Kind.Lit, Kind.Char):
744 tok = self.cur_token
745 # Happens in lex_mode_e.SQ: 'one\two' is ambiguous, should be
746 # r'one\two' or c'one\\two'
747 if no_backslashes and lexer.TokenContains(tok, '\\'):
748 p_die(
749 "Ambiguous backslash: add explicit r'' or u'' prefix (OILS-ERR-20)",
750 tok)
751
752 if is_ysh_expr:
753 # Disallow var x = $'\001'. Arguably we don't need these
754 # checks because u'\u{1}' is the way to write it.
755 if self.token_type == Id.Char_Octal3:
756 p_die(
757 r"Use \xhh or \u{...} instead of octal escapes in YSH strings",
758 tok)
759
760 if self.token_type == Id.Char_Hex and self.cur_token.length != 4:
761 # disallow \xH
762 p_die(
763 r'Invalid hex escape in YSH string (must be \xHH)',
764 tok)
765
766 tokens.append(tok)
767
768 elif self.token_kind == Kind.Unknown:
769 tok = self.cur_token
770 assert tok.id == Id.Unknown_Backslash, tok
771
772 # x = $'\z' is disallowed; ditto for echo $'\z' if shopt --set no_parse_backslash
773 if is_ysh_expr or self.parse_opts.no_parse_backslash():
774 p_die(
775 "Invalid char escape in C-style string literal (OILS-ERR-11)",
776 tok)
777
778 tokens.append(tok)
779
780 elif self.token_kind == Kind.Eof:
781 p_die('Unexpected EOF in single-quoted string that began here',
782 left_token)
783
784 elif self.token_kind == Kind.Right:
785 # assume Id.Right_SingleQuote
786 num_end_tokens += 1
787 tokens.append(self.cur_token)
788
789 else:
790 raise AssertionError(self.cur_token)
791
792 if self.token_kind != Kind.Right:
793 num_end_tokens = 0 # we need three in a ROW
794
795 if expected_end_tokens == 1:
796 tokens.pop()
797 elif expected_end_tokens == 3: # Get rid of spurious end tokens
798 tokens.pop()
799 tokens.pop()
800 tokens.pop()
801
802 # Remove space from ''' r''' $''' in both expression mode and command mode
803 if left_token.id in (Id.Left_TSingleQuote, Id.Left_RTSingleQuote,
804 Id.Left_UTSingleQuote, Id.Left_BTSingleQuote):
805 word_compile.RemoveLeadingSpaceSQ(tokens)
806
807 # Validation after lexing - same 2 checks in j8.LexerDecoder
808 is_u_string = left_token.id in (Id.Left_USingleQuote,
809 Id.Left_UTSingleQuote)
810
811 for tok in tokens:
812 # u'\yff' is not valid, but b'\yff' is
813 if is_u_string and tok.id == Id.Char_YHex:
814 p_die(
815 r"%s escapes not allowed in u'' strings" %
816 lexer.TokenVal(tok), tok)
817
818 out_tokens.extend(tokens)
819 return self.cur_token
820
821 def _ReadDoubleQuotedLeftParts(self):
822 # type: () -> word_part_t
823 """Read substitution parts in a double quoted context."""
824 if self.token_type in (Id.Left_DollarParen, Id.Left_Backtick):
825 return self._ReadCommandSub(self.token_type, d_quoted=True)
826
827 if self.token_type == Id.Left_DollarBrace:
828 return self._ReadBracedVarSub(self.cur_token, d_quoted=True)
829
830 if self.token_type == Id.Left_DollarDParen:
831 # TODO: Uncomment this after another regtest/aports run
832 # if (self.LookAheadDParens(shift_back=1)):
833 return self._ReadArithSub()
834 # else:
835 # Mutate token - we treat this '$((' as '$( ('
836 # self.cur_token.id = Id.Left_DollarParen
837 # return self._ReadCommandSub(Id.Left_DollarParen, d_quoted=True)
838
839 if self.token_type == Id.Left_DollarBracket:
840
841 if self.parse_opts.parse_ysh_expr_sub():
842 return self._ReadExprSub(lex_mode_e.DQ)
843 else:
844 return self._ReadArithSub(end_id=Id.Arith_RBracket)
845
846 if self.token_type == Id.Left_DollarBraceZsh:
847 return self._ReadZshVarSub(self.cur_token)
848
849 raise AssertionError(self.cur_token)
850
851 def _ReadYshSingleQuoted(self, left_id):
852 # type: (Id_t) -> CompoundWord
853 """Read YSH style strings
854
855 r'' u'' b''
856 r''' ''' u''' ''' b''' '''
857 """
858 #log('BEF self.cur_token %s', self.cur_token)
859 if left_id == Id.Left_RSingleQuote:
860 lexer_mode = lex_mode_e.SQ_Raw
861 triple_left_id = Id.Left_RTSingleQuote
862 elif left_id == Id.Left_USingleQuote:
863 lexer_mode = lex_mode_e.J8_Str
864 triple_left_id = Id.Left_UTSingleQuote
865 elif left_id == Id.Left_BSingleQuote:
866 lexer_mode = lex_mode_e.J8_Str
867 triple_left_id = Id.Left_BTSingleQuote
868 else:
869 raise AssertionError(left_id)
870
871 # Needed for syntax checks
872 left_tok = self.cur_token
873 left_tok.id = left_id
874
875 sq_part = self._ReadSingleQuoted(left_tok, lexer_mode)
876
877 if (len(sq_part.sval) == 0 and self.lexer.ByteLookAhead() == "'"):
878 self._SetNext(lex_mode_e.ShCommand)
879 self._GetToken()
880
881 assert self.token_type == Id.Left_SingleQuote
882 # HACK: magically transform the third ' in u''' to
883 # Id.Left_UTSingleQuote, so that ''' is the terminator
884 left_tok = self.cur_token
885 left_tok.id = triple_left_id
886
887 # Handles stripping leading whitespace
888 sq_part = self._ReadSingleQuoted(left_tok, lexer_mode)
889
890 # Advance and validate
891 self._SetNext(lex_mode_e.ShCommand)
892
893 self._GetToken()
894 if self.token_kind not in KINDS_THAT_END_WORDS:
895 p_die('Unexpected token after YSH single-quoted string',
896 self.cur_token)
897
898 return CompoundWord([sq_part])
899
900 def _ReadUnquotedLeftParts(self, triple_out):
901 # type: (Optional[BoolParamBox]) -> word_part_t
902 """Read substitutions and quoted strings (for lex_mode_e.ShCommand).
903
904 If triple_out is set, then we try parsing triple quoted strings,
905 and set its value to True if we got one.
906 """
907 if self.token_type in (Id.Left_DoubleQuote, Id.Left_DollarDoubleQuote):
908 # Note: $"" is a synonym for "". It might make sense if it added
909 # \n \0 \x00 \u{123} etc. But that's not what bash does!
910 dq_part = self._ReadDoubleQuoted(self.cur_token)
911 # Got empty word "" and there's a " after
912 if (triple_out and len(dq_part.parts) == 0 and
913 self.lexer.ByteLookAhead() == '"'):
914
915 self._SetNext(lex_mode_e.ShCommand)
916 self._GetToken()
917 # HACK: magically transform the third " in """ to
918 # Id.Left_TDoubleQuote, so that """ is the terminator
919 left_dq_token = self.cur_token
920 left_dq_token.id = Id.Left_TDoubleQuote
921 triple_out.b = True # let caller know we got it
922 return self._ReadDoubleQuoted(left_dq_token)
923
924 return dq_part
925
926 if self.token_type in (Id.Left_SingleQuote, Id.Left_RSingleQuote,
927 Id.Left_DollarSingleQuote):
928 if self.token_type == Id.Left_SingleQuote:
929 lexer_mode = lex_mode_e.SQ_Raw
930 triple_left_id = Id.Left_TSingleQuote
931 elif self.token_type == Id.Left_RSingleQuote:
932 lexer_mode = lex_mode_e.SQ_Raw
933 triple_left_id = Id.Left_RTSingleQuote
934 else:
935 lexer_mode = lex_mode_e.SQ_C
936 # there is no such thing as $'''
937 triple_left_id = Id.Undefined_Tok
938
939 sq_part = self._ReadSingleQuoted(self.cur_token, lexer_mode)
940
941 # Got empty '' or r'' and there's a ' after
942 # u'' and b'' are handled in _ReadYshSingleQuoted
943 if (triple_left_id != Id.Undefined_Tok and
944 triple_out is not None and len(sq_part.sval) == 0 and
945 self.lexer.ByteLookAhead() == "'"):
946
947 self._SetNext(lex_mode_e.ShCommand)
948 self._GetToken()
949
950 # HACK: magically transform the third ' in ''' to
951 # Id.Left_TSingleQuote, so that ''' is the terminator
952 left_sq_token = self.cur_token
953 left_sq_token.id = triple_left_id
954
955 triple_out.b = True # let caller know we got it
956 return self._ReadSingleQuoted(left_sq_token, lexer_mode)
957
958 return sq_part
959
960 if self.token_type in (Id.Left_DollarParen, Id.Left_Backtick,
961 Id.Left_ProcSubIn, Id.Left_ProcSubOut):
962 return self._ReadCommandSub(self.token_type, d_quoted=False)
963
964 if self.token_type == Id.Left_DollarBrace:
965 return self._ReadBracedVarSub(self.cur_token, d_quoted=False)
966
967 if self.token_type == Id.Left_DollarDParen:
968 # TODO: Uncomment this after another regtest/aports run
969 # if (self.LookAheadDParens(shift_back=1)):
970 return self._ReadArithSub()
971 # else:
972 # Mutate token - we treat this '$((' as '$( ('
973 # self.cur_token.id = Id.Left_DollarParen
974 # return self._ReadCommandSub(Id.Left_DollarParen, d_quoted=True)
975
976 if self.token_type == Id.Left_DollarBracket:
977 if self.parse_opts.parse_ysh_expr_sub():
978 return self._ReadExprSub(lex_mode_e.ShCommand)
979 else:
980 return self._ReadArithSub(end_id=Id.Arith_RBracket)
981
982 if self.token_type == Id.Left_DollarBraceZsh:
983 return self._ReadZshVarSub(self.cur_token)
984
985 raise AssertionError(self.cur_token)
986
987 def _ReadExtGlob(self):
988 # type: () -> word_part.ExtGlob
989 """
990 Grammar:
991 Item = CompoundWord | EPSILON # important: @(foo|) is allowed
992 LEFT = '@(' | '*(' | '+(' | '?(' | '!('
993 RIGHT = ')'
994 ExtGlob = LEFT (Item '|')* Item RIGHT # ITEM may be empty
995 Compound includes ExtGlob
996 """
997 left_token = self.cur_token
998 right_token = None # type: Token
999 arms = [] # type: List[CompoundWord]
1000
1001 self.lexer.PushHint(Id.Op_RParen, Id.Right_ExtGlob)
1002 self._SetNext(lex_mode_e.ExtGlob) # advance past LEFT
1003
1004 read_word = False # did we just a read a word? To handle @(||).
1005
1006 while True:
1007 self._GetToken()
1008
1009 if self.token_type == Id.Right_ExtGlob:
1010 if not read_word:
1011 arms.append(CompoundWord([]))
1012 right_token = self.cur_token
1013 break
1014
1015 elif self.token_type == Id.Op_Pipe:
1016 if not read_word:
1017 arms.append(CompoundWord([]))
1018 read_word = False
1019 self._SetNext(lex_mode_e.ExtGlob)
1020
1021 # lex_mode_e.ExtGlob should only produce these 4 kinds of tokens
1022 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub,
1023 Kind.ExtGlob):
1024 w = self._ReadCompoundWord(lex_mode_e.ExtGlob)
1025 arms.append(w)
1026 read_word = True
1027
1028 elif self.token_kind == Kind.Eof:
1029 p_die('Unexpected EOF reading extended glob that began here',
1030 left_token)
1031
1032 else:
1033 raise AssertionError(self.cur_token)
1034
1035 return word_part.ExtGlob(left_token, arms, right_token)
1036
1037 def _ReadBashRegexGroup(self):
1038 # type: () -> word_part.BashRegexGroup
1039 """
1040 Grammar:
1041 BashRegexGroup = '(' WORD? ')
1042 """
1043 left_token = self.cur_token
1044 assert left_token.id == Id.BashRegex_LParen, left_token
1045
1046 arms = [] # type: List[CompoundWord]
1047
1048 self.lexer.PushHint(Id.Op_RParen, Id.Right_BashRegexGroup)
1049 self._SetNext(lex_mode_e.BashRegexFakeInner) # advance past LEFT
1050
1051 self._GetToken()
1052 if self.token_type == Id.Right_BashRegexGroup: # empty ()
1053 return word_part.BashRegexGroup(left_token, None, self.cur_token)
1054
1055 # lex_mode_e.BashRegex should only produce these 4 kinds of tokens
1056 if self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub, Kind.BashRegex):
1057 # Fake lexer mode that translates Id.WS_Space to Id.Lit_Chars
1058 # To allow bash style [[ s =~ (a b) ]]
1059 w = self._ReadCompoundWord(lex_mode_e.BashRegexFakeInner)
1060 arms.append(w)
1061
1062 self._GetToken()
1063 if self.token_type != Id.Right_BashRegexGroup:
1064 p_die('Expected ) to close bash regex group', self.cur_token)
1065
1066 return word_part.BashRegexGroup(left_token, w, self.cur_token)
1067
1068 p_die('Expected word after ( opening bash regex group', self.cur_token)
1069
1070 def _ReadLikeDQ(self, left_token, is_ysh_expr, out_parts):
1071 # type: (Optional[Token], bool, List[word_part_t]) -> None
1072 """
1073 Args:
1074 left_token: A token if we are reading a double quoted part, or None if
1075 we're reading a here doc.
1076 is_ysh_expr: Whether to disallow backticks and invalid char escapes
1077 out_parts: list of word_part to append to
1078 """
1079 if left_token:
1080 if left_token.id in (Id.Left_TDoubleQuote,
1081 Id.Left_DollarTDoubleQuote):
1082 expected_end_tokens = 3
1083 else:
1084 expected_end_tokens = 1
1085 else:
1086 expected_end_tokens = 1000 # here doc will break
1087
1088 num_end_tokens = 0
1089 while num_end_tokens < expected_end_tokens:
1090 self._SetNext(lex_mode_e.DQ)
1091 self._GetToken()
1092
1093 if self.token_kind == Kind.Lit:
1094 if self.token_type == Id.Lit_EscapedChar:
1095 tok = self.cur_token
1096 ch = lexer.TokenSliceLeft(tok, 1)
1097 part = word_part.EscapedLiteral(tok,
1098 ch) # type: word_part_t
1099
1100 elif self.token_type == Id.Lit_EscapedDoubleQuote:
1101 if left_token:
1102 part = word_part.EscapedLiteral(tok, "\"")
1103 else:
1104 # in here docs \" should not be escaped, staying as literal characters
1105 tok = self.cur_token
1106 part = Token(Id.Lit_Chars, tok.length, tok.col,
1107 tok.line, tok.tval)
1108
1109 else:
1110 if self.token_type == Id.Lit_BadBackslash:
1111 # echo "\z" is OK in shell, but 'x = "\z" is a syntax error in
1112 # YSH.
1113 # Slight hole: We don't catch 'x = ${undef:-"\z"} because of the
1114 # recursion (unless no_parse_backslash)
1115 if (is_ysh_expr or
1116 self.parse_opts.no_parse_backslash()):
1117 p_die(
1118 "Invalid char escape in double quoted string (OILS-ERR-12)",
1119 self.cur_token)
1120 elif self.token_type == Id.Lit_Dollar:
1121 if is_ysh_expr or self.parse_opts.no_parse_dollar():
1122 p_die("Literal $ should be quoted like \$",
1123 self.cur_token)
1124
1125 part = self.cur_token
1126
1127 out_parts.append(part)
1128
1129 elif self.token_kind == Kind.Left:
1130 if self.token_type == Id.Left_Backtick and is_ysh_expr:
1131 p_die("Backtick should be $(cmd) or \\` (OILS-ERR-18)",
1132 self.cur_token)
1133
1134 part = self._ReadDoubleQuotedLeftParts()
1135 out_parts.append(part)
1136
1137 elif self.token_kind == Kind.VSub:
1138 tok = self.cur_token
1139 part = SimpleVarSub(tok)
1140 out_parts.append(part)
1141 # NOTE: parsing "$f(x)" would BREAK CODE. Could add a more for it
1142 # later.
1143
1144 elif self.token_kind == Kind.Right:
1145 assert self.token_type == Id.Right_DoubleQuote, self.token_type
1146 if left_token:
1147 num_end_tokens += 1
1148
1149 # In a here doc, the right quote is literal!
1150 out_parts.append(self.cur_token)
1151
1152 elif self.token_kind == Kind.Eof:
1153 if left_token:
1154 p_die(
1155 'Unexpected EOF reading double-quoted string that began here',
1156 left_token)
1157 else: # here docs will have an EOF in their token stream
1158 break
1159
1160 else:
1161 raise AssertionError(self.cur_token)
1162
1163 if self.token_kind != Kind.Right:
1164 num_end_tokens = 0 # """ must be CONSECUTIVE
1165
1166 if expected_end_tokens == 1:
1167 out_parts.pop()
1168 elif expected_end_tokens == 3:
1169 out_parts.pop()
1170 out_parts.pop()
1171 out_parts.pop()
1172
1173 # Remove space from """ in both expression mode and command mode
1174 if (left_token and left_token.id
1175 in (Id.Left_TDoubleQuote, Id.Left_DollarTDoubleQuote)):
1176 word_compile.RemoveLeadingSpaceDQ(out_parts)
1177
1178 # Return nothing, since we appended to 'out_parts'
1179
1180 def _ReadDoubleQuoted(self, left_token):
1181 # type: (Token) -> DoubleQuoted
1182 """Helper function for "hello $name".
1183
1184 Args:
1185 eof_type: for stopping at }, Id.Lit_RBrace
1186 here_doc: Whether we are reading in a here doc context
1187
1188 Also ${foo%%a b c} # treat this as double quoted. until you hit
1189 """
1190 parts = [] # type: List[word_part_t]
1191 self._ReadLikeDQ(left_token, False, parts)
1192
1193 right_quote = self.cur_token
1194 return DoubleQuoted(left_token, parts, right_quote)
1195
1196 def ReadDoubleQuoted(self, left_token, parts):
1197 # type: (Token, List[word_part_t]) -> Token
1198 """For expression mode.
1199
1200 Read var x = "${dir:-}/$name"; etc.
1201 """
1202 self._ReadLikeDQ(left_token, True, parts)
1203 return self.cur_token
1204
1205 def _ReadCommandSub(self, left_id, d_quoted=False):
1206 # type: (Id_t, bool) -> CommandSub
1207 """
1208 NOTE: This is not in the grammar, because word parts aren't in the grammar!
1209
1210 command_sub = '$(' command_list ')'
1211 | '@(' command_list ')'
1212 | '<(' command_list ')'
1213 | '>(' command_list ')'
1214 | ` command_list `
1215 """
1216 left_token = self.cur_token
1217
1218 # Set the lexer in a state so ) becomes the EOF token.
1219 if left_id in (Id.Left_DollarParen, Id.Left_AtParen, Id.Left_ProcSubIn,
1220 Id.Left_ProcSubOut):
1221 self._SetNext(lex_mode_e.ShCommand) # advance past $( etc.
1222
1223 right_id = Id.Eof_RParen
1224 self.lexer.PushHint(Id.Op_RParen, right_id)
1225 c_parser = self.parse_ctx.MakeParserForCommandSub(
1226 self.line_reader, self.lexer, right_id)
1227 # NOTE: This doesn't use something like main_loop because we don't want
1228 # to interleave parsing and execution! Unlike 'source' and 'eval'.
1229 node = c_parser.ParseCommandSub()
1230
1231 right_token = c_parser.w_parser.cur_token
1232
1233 elif left_id == Id.Left_Backtick and self.parse_ctx.do_lossless:
1234 # NOTE: This is an APPROXIMATE solution for translation ONLY. See
1235 # test/osh2oil.
1236
1237 right_id = Id.Eof_Backtick
1238 self.lexer.PushHint(Id.Left_Backtick, right_id)
1239 c_parser = self.parse_ctx.MakeParserForCommandSub(
1240 self.line_reader, self.lexer, right_id)
1241 node = c_parser.ParseCommandSub()
1242 right_token = c_parser.w_parser.cur_token
1243
1244 elif left_id == Id.Left_Backtick:
1245 if self.parse_opts.no_parse_backticks():
1246 p_die(
1247 'Backtick should be $(cmd) or \\` (no_parse_backticks, OILS-ERR-18)',
1248 left_token)
1249
1250 self._SetNext(lex_mode_e.Backtick) # advance past `
1251
1252 parts = [] # type: List[str]
1253 while True:
1254 self._GetToken()
1255 #log("TOK %s", self.cur_token)
1256
1257 if self.token_type == Id.Backtick_Quoted:
1258 # Remove leading \
1259 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1260
1261 elif self.token_type == Id.Backtick_DoubleQuote:
1262 # Compatibility: If backticks are double quoted, then double quotes
1263 # within them have to be \"
1264 # Shells aren't smart enough to match nested " and ` quotes (but OSH
1265 # is)
1266 if d_quoted:
1267 # Remove leading \
1268 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1269 else:
1270 parts.append(lexer.TokenVal(self.cur_token))
1271
1272 elif self.token_type == Id.Backtick_Other:
1273 parts.append(lexer.TokenVal(self.cur_token))
1274
1275 elif self.token_type == Id.Backtick_Right:
1276 break
1277
1278 elif self.token_type == Id.Eof_Real:
1279 # Note: this parse error is in the ORIGINAL context. No code_str yet.
1280 p_die('Unexpected EOF while looking for closing backtick',
1281 left_token)
1282
1283 else:
1284 raise AssertionError(self.cur_token)
1285
1286 self._SetNext(lex_mode_e.Backtick)
1287
1288 # Calculate right SPID on CommandSub BEFORE re-parsing.
1289 right_token = self.cur_token
1290
1291 code_str = ''.join(parts)
1292 #log('code %r', code_str)
1293
1294 # Save lines into a new, temporary arena, so SnipCodeBlock() isn't
1295 # messed up. Note: This is similar to how we parse aliases in
1296 # osh/cmd_parse.py. It won't have the same location info as
1297 # MakeParserForCommandSub(), because the reader is different.
1298 arena = alloc.Arena()
1299 # TODO: arena.PushSource()?
1300
1301 line_reader = reader.StringLineReader(code_str, arena)
1302 c_parser = self.parse_ctx.MakeOshParser(line_reader)
1303 src = source.Reparsed('backticks', left_token, right_token)
1304 with alloc.ctx_SourceCode(arena, src):
1305 node = c_parser.ParseCommandSub()
1306
1307 else:
1308 raise AssertionError(left_id)
1309
1310 return CommandSub(left_token, node, right_token)
1311
1312 def _ReadExprSub(self, lex_mode):
1313 # type: (lex_mode_t) -> ExprSub
1314 """$[d->key] $[obj.method()] etc."""
1315 left_token = self.cur_token
1316
1317 self._SetNext(lex_mode_e.Expr)
1318 enode, right_token = self.parse_ctx.ParseYshExpr(
1319 self.lexer, grammar_nt.ysh_expr_sub)
1320
1321 self._SetNext(lex_mode) # Move past ]
1322 return ExprSub(left_token, enode, right_token)
1323
1324 def ParseVarDecl(self, kw_token):
1325 # type: (Token) -> VarDecl
1326 """
1327 oil_var_decl: name_type_list '=' testlist end_stmt
1328
1329 Note that assignments must end with \n ; } or EOF. Unlike shell
1330 assignments, we disallow:
1331
1332 var x = 42 | wc -l
1333 var x = 42 && echo hi
1334 """
1335 self._SetNext(lex_mode_e.Expr)
1336 enode, last_token = self.parse_ctx.ParseVarDecl(kw_token, self.lexer)
1337 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1338 # wants
1339 if last_token.id == Id.Op_RBrace:
1340 last_token.id = Id.Lit_RBrace
1341
1342 # Let the CommandParser see the Op_Semi or Op_Newline.
1343 self.buffered_word = last_token
1344 self._SetNext(lex_mode_e.ShCommand) # always back to this
1345 return enode
1346
1347 def ParseMutation(self, kw_token, var_checker):
1348 # type: (Token, VarChecker) -> Mutation
1349 """
1350 setvar i = 42
1351 setvar i += 1
1352 setvar a[i] = 42
1353 setvar a[i] += 1
1354 setvar d.key = 42
1355 setvar d.key += 1
1356 """
1357 self._SetNext(lex_mode_e.Expr)
1358 enode, last_token = self.parse_ctx.ParseMutation(kw_token, self.lexer)
1359 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1360 # wants
1361 if last_token.id == Id.Op_RBrace:
1362 last_token.id = Id.Lit_RBrace
1363
1364 for lhs in enode.lhs:
1365 UP_lhs = lhs
1366 with tagswitch(lhs) as case:
1367 if case(y_lhs_e.Var):
1368 lhs = cast(Token, UP_lhs)
1369 var_checker.Check(kw_token.id, lexer.LazyStr(lhs), lhs)
1370
1371 # Note: this does not cover cases like
1372 # setvar (a[0])[1] = v
1373 # setvar (d.key).other = v
1374 # This leaks into catching all typos statically, which may be
1375 # possible if 'use' makes all names explicit.
1376 elif case(y_lhs_e.Subscript):
1377 lhs = cast(Subscript, UP_lhs)
1378 if lhs.obj.tag() == expr_e.Var:
1379 v = cast(expr.Var, lhs.obj)
1380 var_checker.Check(kw_token.id, v.name, v.left)
1381
1382 elif case(y_lhs_e.Attribute):
1383 lhs = cast(Attribute, UP_lhs)
1384 if lhs.obj.tag() == expr_e.Var:
1385 v = cast(expr.Var, lhs.obj)
1386 var_checker.Check(kw_token.id, v.name, v.left)
1387
1388 # Let the CommandParser see the Op_Semi or Op_Newline.
1389 self.buffered_word = last_token
1390 self._SetNext(lex_mode_e.ShCommand) # always back to this
1391 return enode
1392
1393 def ParseBareDecl(self):
1394 # type: () -> expr_t
1395 """
1396 x = {name: val}
1397 """
1398 self._SetNext(lex_mode_e.Expr)
1399 self._GetToken()
1400 enode, last_token = self.parse_ctx.ParseYshExpr(
1401 self.lexer, grammar_nt.command_expr)
1402 if last_token.id == Id.Op_RBrace:
1403 last_token.id = Id.Lit_RBrace
1404 self.buffered_word = last_token
1405 self._SetNext(lex_mode_e.ShCommand)
1406 return enode
1407
1408 def ParseYshExprForCommand(self):
1409 # type: () -> expr_t
1410
1411 # Fudge for this case
1412 # for x in(y) {
1413 # versus
1414 # for x in (y) {
1415 #
1416 # In the former case, ReadWord on 'in' puts the lexer past (.
1417 # Also see LookPastSpace in CommandParers.
1418 # A simpler solution would be nicer.
1419
1420 if self.token_type == Id.Op_LParen:
1421 self.lexer.MaybeUnreadOne()
1422
1423 enode, _ = self.parse_ctx.ParseYshExpr(self.lexer, grammar_nt.ysh_expr)
1424
1425 self._SetNext(lex_mode_e.ShCommand)
1426 return enode
1427
1428 def ParseCommandExpr(self):
1429 # type: () -> expr_t
1430 """
1431 = 1+2
1432 """
1433 enode, last_token = self.parse_ctx.ParseYshExpr(
1434 self.lexer, grammar_nt.command_expr)
1435
1436 # In some cases, such as the case statement, we expect *the lexer* to be
1437 # pointing at the token right after the expression. But the expression
1438 # parser must have read to the `last_token`. Unreading places the lexer
1439 # back in the expected state. Ie:
1440 #
1441 # case (x) { case (x) {
1442 # (else) { = x } (else) { = x }
1443 # ^ The lexer is here ^ Unread to here
1444 # } }
1445 assert last_token.id in (Id.Op_Newline, Id.Eof_Real, Id.Op_Semi,
1446 Id.Op_RBrace), last_token
1447 if last_token.id != Id.Eof_Real:
1448 # Eof_Real is the only token we cannot unread
1449 self.lexer.MaybeUnreadOne()
1450
1451 return enode
1452
1453 def ParseProc(self, node):
1454 # type: (Proc) -> None
1455
1456 # proc name-with-hyphens() must be accepted
1457 self._SetNext(lex_mode_e.ShCommand)
1458 self._GetToken()
1459 # example: 'proc f[' gets you Lit_ArrayLhsOpen
1460 if self.token_type != Id.Lit_Chars:
1461 p_die('Invalid proc name %s' % ui.PrettyToken(self.cur_token),
1462 self.cur_token)
1463
1464 # TODO: validate this more. Disallow proc 123 { }, which isn't disallowed
1465 # for shell functions. Similar to IsValidVarName().
1466 node.name = self.cur_token
1467
1468 last_token = self.parse_ctx.ParseProc(self.lexer, node)
1469
1470 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1471 assert last_token.id == Id.Op_LBrace
1472 last_token.id = Id.Lit_LBrace
1473 self.buffered_word = last_token
1474
1475 self._SetNext(lex_mode_e.ShCommand)
1476
1477 def ParseFunc(self, node):
1478 # type: (Func) -> None
1479 last_token = self.parse_ctx.ParseFunc(self.lexer, node)
1480
1481 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1482 assert last_token.id == Id.Op_LBrace
1483 last_token.id = Id.Lit_LBrace
1484 self.buffered_word = last_token
1485
1486 self._SetNext(lex_mode_e.ShCommand)
1487
1488 def ParseYshCasePattern(self):
1489 # type: () -> Tuple[pat_t, Token]
1490 pat, left_tok, last_token = self.parse_ctx.ParseYshCasePattern(
1491 self.lexer)
1492
1493 if last_token.id == Id.Op_LBrace:
1494 last_token.id = Id.Lit_LBrace
1495 self.buffered_word = last_token
1496
1497 return pat, left_tok
1498
1499 def NewlineOkForYshCase(self):
1500 # type: () -> Id_t
1501 """Check for optional newline and consume it.
1502
1503 This is a special case of `_NewlineOk` which fixed some "off-by-one" issues
1504 which crop up while parsing Ysh Case Arms. For more details, see
1505 #oil-dev > Progress On YSH Case Grammar on zulip.
1506
1507 Returns a token id which is filled with the choice of
1508
1509 word { echo word }
1510 (3) { echo expr }
1511 /e/ { echo eggex }
1512 } # right brace
1513 """
1514 while True:
1515 next_id = self.lexer.LookAheadOne(lex_mode_e.Expr)
1516
1517 # Cannot lookahead past lines
1518 if next_id == Id.Unknown_Tok:
1519 if not self.lexer.MoveToNextLine(): # Try to move to next line
1520 break # EOF
1521 continue
1522
1523 next_kind = consts.GetKind(next_id)
1524 if next_id != Id.Op_Newline and next_kind != Kind.Ignored:
1525 break
1526
1527 self.lexer.Read(lex_mode_e.Expr)
1528
1529 if next_id in (Id.Op_RBrace, Id.Op_LParen, Id.Arith_Slash):
1530 self._SetNext(lex_mode_e.Expr) # Continue in expression mode
1531 else:
1532 # Consume the trailing Op_Newline
1533 self._SetNext(lex_mode_e.ShCommand)
1534 self._GetToken()
1535
1536 return next_id
1537
1538 def _ReadArithExpr(self, end_id):
1539 # type: (Id_t) -> arith_expr_t
1540 """Read and parse an arithmetic expression in various contexts.
1541
1542 $(( 1+2 ))
1543 (( a=1+2 ))
1544 ${a[ 1+2 ]}
1545 ${a : 1+2 : 1+2}
1546
1547 See tests/arith-context.test.sh for ambiguous cases.
1548
1549 ${a[a[0]]} is valid # VS_RBRACKET vs Id.Arith_RBracket
1550
1551 ${s : a<b?0:1 : 1} # VS_COLON vs Id.Arith_Colon
1552
1553 See the assertion in ArithParser.Parse() -- unexpected extra input.
1554 """
1555 # calls self.ReadWord(lex_mode_e.Arith)
1556 anode = self.a_parser.Parse()
1557 cur_id = self.a_parser.CurrentId()
1558 if end_id != Id.Undefined_Tok and cur_id != end_id:
1559 p_die(
1560 'Unexpected token after arithmetic expression (%s != %s)' %
1561 (ui.PrettyId(cur_id), ui.PrettyId(end_id)),
1562 loc.Word(self.a_parser.cur_word))
1563 return anode
1564
1565 def _ReadArithSub(self, end_id=Id.Arith_RParen):
1566 # type: (Id_t) -> word_part.ArithSub
1567 """Read an arith substitution, which contains an arith expression, e.g.
1568
1569 $((a + 1)).
1570 """
1571 assert end_id in (Id.Arith_RParen, Id.Arith_RBracket)
1572
1573 left_tok = self.cur_token
1574
1575 # The second one needs to be disambiguated in stuff like stuff like:
1576 # $(echo $(( 1+2 )) )
1577 if end_id == Id.Arith_RParen:
1578 self.lexer.PushHint(Id.Op_RParen, Id.Right_DollarDParen)
1579
1580 # NOTE: To disambiguate $(( as arith sub vs. command sub and subshell, we
1581 # could save the lexer/reader state here, and retry if the arithmetic parse
1582 # fails. But we can almost always catch this at parse time. There could
1583 # be some exceptions like:
1584 # $((echo * foo)) # looks like multiplication
1585 # $((echo / foo)) # looks like division
1586
1587 # $(( )) is valid
1588 anode = arith_expr.EmptyZero # type: arith_expr_t
1589
1590 self._NextNonSpace()
1591 if self.token_type != Id.Arith_RParen:
1592 anode = self._ReadArithExpr(end_id)
1593
1594 self._SetNext(lex_mode_e.ShCommand)
1595
1596 if end_id == Id.Arith_RParen:
1597 # Ensure we get closing ) if we are looking for double ))
1598 # (In backwards compat mode, ] can also be the closing bracket, and
1599 # it would already be the current token, no need to skip further
1600 self._GetToken()
1601 if self.token_type != Id.Right_DollarDParen:
1602 p_die('Expected second ) to end arith sub', self.cur_token)
1603
1604 right_tok = self.cur_token
1605 return word_part.ArithSub(left_tok, anode, right_tok)
1606
1607 def ReadDParen(self):
1608 # type: () -> Tuple[arith_expr_t, Token]
1609 """Read ((1+ 2)) -- command context.
1610
1611 We're using the word parser because it's very similar to _ReadArithExpr
1612 above.
1613
1614 This also returns the terminating Id.Op_DRightParen token for location
1615 info.
1616 """
1617 # (( )) is valid
1618 anode = arith_expr.EmptyZero # type: arith_expr_t
1619
1620 self.lexer.PushHint(Id.Op_RParen, Id.Op_DRightParen)
1621
1622 self._NextNonSpace()
1623 if self.token_type != Id.Arith_RParen:
1624 anode = self._ReadArithExpr(Id.Arith_RParen)
1625
1626 self._SetNext(lex_mode_e.ShCommand)
1627
1628 # Ensure we get the second )
1629 self._GetToken()
1630 right = self.cur_token
1631 if right.id != Id.Op_DRightParen:
1632 p_die('Expected second ) to end arith statement', right)
1633
1634 self._SetNext(lex_mode_e.ShCommand)
1635
1636 return anode, right
1637
1638 def _NextNonSpace(self):
1639 # type: () -> None
1640 """Advance in lex_mode_e.Arith until non-space token.
1641
1642 Same logic as _ReadWord, but used in
1643 $(( ))
1644 (( ))
1645 for (( ))
1646
1647 You can read self.token_type after this, without calling _GetToken.
1648 """
1649 while True:
1650 self._SetNext(lex_mode_e.Arith)
1651 self._GetToken()
1652 if self.token_kind not in (Kind.Ignored, Kind.WS):
1653 break
1654
1655 def ReadForExpression(self):
1656 # type: () -> command.ForExpr
1657 """Read ((i=0; i<5; ++i)) -- part of command context."""
1658 self._NextNonSpace() # skip over ((
1659 cur_id = self.token_type # for end of arith expressions
1660
1661 if cur_id == Id.Arith_Semi: # for (( ; i < 10; i++ ))
1662 init_node = arith_expr.EmptyZero # type: arith_expr_t
1663 else:
1664 init_node = self.a_parser.Parse()
1665 cur_id = self.a_parser.CurrentId()
1666 self._NextNonSpace()
1667
1668 # It's odd to keep track of both cur_id and self.token_type in this
1669 # function, but it works, and is tested in 'test/parse_error.sh
1670 # arith-integration'
1671 if cur_id != Id.Arith_Semi: # for (( x=0 b; ... ))
1672 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1673
1674 self._GetToken()
1675 cur_id = self.token_type
1676
1677 if cur_id == Id.Arith_Semi: # for (( ; ; i++ ))
1678 # empty condition is TRUE
1679 cond_node = arith_expr.EmptyOne # type: arith_expr_t
1680 else:
1681 cond_node = self.a_parser.Parse()
1682 cur_id = self.a_parser.CurrentId()
1683
1684 if cur_id != Id.Arith_Semi: # for (( x=0; x<5 b ))
1685 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1686
1687 self._NextNonSpace()
1688 if self.token_type == Id.Arith_RParen: # for (( ; ; ))
1689 update_node = arith_expr.EmptyZero # type: arith_expr_t
1690 else:
1691 update_node = self._ReadArithExpr(Id.Arith_RParen)
1692
1693 self._NextNonSpace()
1694 if self.token_type != Id.Arith_RParen:
1695 p_die('Expected ) to end for loop expression', self.cur_token)
1696 self._SetNext(lex_mode_e.ShCommand)
1697
1698 # redirects is None, will be assigned in CommandEvaluator
1699 node = command.ForExpr.CreateNull()
1700 node.init = init_node
1701 node.cond = cond_node
1702 node.update = update_node
1703 return node
1704
1705 def _ReadArrayLiteral(self):
1706 # type: () -> word_part_t
1707 """a=(1 2 3)
1708
1709 TODO: See osh/cmd_parse.py:164 for Id.Lit_ArrayLhsOpen, for a[x++]=1
1710
1711 We want:
1712
1713 A=(['x']=1 ["x"]=2 [$x$y]=3)
1714
1715 Maybe allow this as a literal string? Because I think I've seen it before?
1716 Or maybe force people to patch to learn the rule.
1717
1718 A=([x]=4)
1719
1720 Starts with Lit_Other '[', and then it has Lit_ArrayLhsClose
1721 Maybe enforce that ALL have keys or NONE of have keys.
1722 """
1723 self._SetNext(lex_mode_e.ShCommand) # advance past (
1724 self._GetToken()
1725 if self.cur_token.id != Id.Op_LParen:
1726 p_die('Expected ( after =', self.cur_token)
1727 left_token = self.cur_token
1728 right_token = None # type: Token
1729
1730 # MUST use a new word parser (with same lexer).
1731 w_parser = self.parse_ctx.MakeWordParser(self.lexer, self.line_reader)
1732 words = [] # type: List[CompoundWord]
1733 done = False
1734 while not done:
1735 w = w_parser.ReadWord(lex_mode_e.ShCommand)
1736 with tagswitch(w) as case:
1737 if case(word_e.Operator):
1738 tok = cast(Token, w)
1739 if tok.id == Id.Right_Initializer:
1740 right_token = tok
1741 done = True # can't use break here
1742 # Unlike command parsing, array parsing allows embedded \n.
1743 elif tok.id == Id.Op_Newline:
1744 continue
1745 else:
1746 p_die('Unexpected token in array literal', loc.Word(w))
1747
1748 elif case(word_e.Compound):
1749 words.append(cast(CompoundWord, w))
1750
1751 else:
1752 raise AssertionError()
1753
1754 initializer_words = [] # type: List[InitializerWord_t]
1755 for w in words:
1756 pair = word_.DetectAssocPair(w)
1757 if pair is not None:
1758 word_.TildeDetectAssign(pair.value) # pair.value is modified
1759 initializer_words.append(pair)
1760 else:
1761 w2 = braces.BraceDetect(w) # type: word_t
1762 if w2 is None:
1763 w2 = w
1764 w3 = word_.TildeDetect(w2) # type: word_t
1765 if w3 is None:
1766 w3 = w2
1767 initializer_words.append(InitializerWord.ArrayWord(w3))
1768
1769 # invariant List?
1770 return word_part.InitializerLiteral(left_token, initializer_words,
1771 right_token)
1772
1773 def ParseProcCallArgs(self, start_symbol):
1774 # type: (int) -> ArgList
1775 """ json write (x) """
1776 self.lexer.MaybeUnreadOne()
1777
1778 arg_list = ArgList.CreateNull(alloc_lists=True)
1779 arg_list.left = self.cur_token
1780 self.parse_ctx.ParseProcCallArgs(self.lexer, arg_list, start_symbol)
1781 return arg_list
1782
1783 def _MaybeReadWordPart(self, is_first, lex_mode, parts):
1784 # type: (bool, lex_mode_t, List[word_part_t]) -> bool
1785 """Helper for _ReadCompoundWord3."""
1786 done = False
1787
1788 if self.token_type == Id.Lit_EscapedChar:
1789 tok = self.cur_token
1790 assert tok.length == 2
1791 ch = lexer.TokenSliceLeft(tok, 1)
1792 if self.parse_opts.no_parse_backslash():
1793 if not pyutil.IsValidCharEscape(ch):
1794 p_die('Invalid char escape in unquoted word (OILS-ERR-13)',
1795 self.cur_token)
1796
1797 part = word_part.EscapedLiteral(self.cur_token,
1798 ch) # type: word_part_t
1799 else:
1800 part = self.cur_token
1801
1802 if is_first and self.token_type == Id.Lit_VarLike: # foo=
1803 parts.append(part)
1804 # Unfortunately it's awkward to pull the check for a=(1 2) up to
1805 # _ReadWord.
1806 next_id = self.lexer.LookPastSpace(lex_mode)
1807 if next_id == Id.Op_LParen:
1808 self.lexer.PushHint(Id.Op_RParen, Id.Right_Initializer)
1809 part2 = self._ReadArrayLiteral()
1810 parts.append(part2)
1811
1812 # Array literal must be the last part of the word.
1813 self._SetNext(lex_mode)
1814 self._GetToken()
1815 # EOF, whitespace, newline, Right_Subshell
1816 if self.token_kind not in KINDS_THAT_END_WORDS:
1817 p_die('Unexpected token after array literal',
1818 self.cur_token)
1819 done = True
1820
1821 elif (is_first and self.parse_opts.parse_at() and
1822 self.token_type == Id.Lit_Splice):
1823
1824 splice_tok = self.cur_token
1825 part2 = word_part.Splice(splice_tok,
1826 lexer.TokenSliceLeft(splice_tok, 1))
1827
1828 parts.append(part2)
1829
1830 # @words must be the last part of the word
1831 self._SetNext(lex_mode)
1832 self._GetToken()
1833 # EOF, whitespace, newline, Right_Subshell
1834 if self.token_kind not in KINDS_THAT_END_WORDS:
1835 p_die('Unexpected token after array splice', self.cur_token)
1836 done = True
1837
1838 elif (is_first and self.parse_opts.parse_at() and
1839 self.token_type == Id.Lit_AtLBracket): # @[split(x)]
1840 part2 = self._ReadExprSub(lex_mode_e.DQ)
1841 parts.append(part2)
1842
1843 # @[split(x)]
1844 self._SetNext(lex_mode)
1845 self._GetToken()
1846 # EOF, whitespace, newline, Right_Subshell
1847 if self.token_kind not in KINDS_THAT_END_WORDS:
1848 p_die('Unexpected token after Expr splice', self.cur_token)
1849 done = True
1850
1851 elif (is_first and self.parse_opts.parse_at() and
1852 self.token_type == Id.Lit_AtLBraceDot):
1853 p_die('TODO: @{.myproc builtin sub}', self.cur_token)
1854
1855 elif (is_first and self.parse_opts.parse_at_all() and
1856 self.token_type == Id.Lit_At):
1857 # Because $[x] ${x} and perhaps $/x/ are reserved, it makes sense for @
1858 # at the beginning of a word to be reserved.
1859
1860 # Although should we relax 'echo @' ? I'm tempted to have a shortcut for
1861 # @_argv and
1862 p_die('Literal @ starting a word must be quoted (parse_at_all)',
1863 self.cur_token)
1864
1865 else:
1866 # not a literal with lookahead; append it
1867 parts.append(part)
1868
1869 return done
1870
1871 def _ReadCompoundWord(self, lex_mode):
1872 # type: (lex_mode_t) -> CompoundWord
1873
1874 # This is the ONLY lexer mode that can return word.Redir
1875 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1876
1877 w = self._ReadCompoundOrRedir(lex_mode)
1878 assert w.tag() == word_e.Compound, w
1879 return cast(CompoundWord, w)
1880
1881 def _ReadCompoundWord3(self, lex_mode, eof_type, empty_ok):
1882 # type: (lex_mode_t, Id_t, bool) -> CompoundWord
1883
1884 # This is the ONLY lexer mode that can return word.Redir
1885 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1886
1887 w = self._ReadCompoundOrRedir3(lex_mode, eof_type, empty_ok)
1888 assert w.tag() == word_e.Compound, w
1889 return cast(CompoundWord, w)
1890
1891 def _ReadCompoundOrRedir(self, lex_mode):
1892 # type: (lex_mode_t) -> word_t
1893 """Returns either word.Compound or word.Redir"""
1894 return self._ReadCompoundOrRedir3(lex_mode, Id.Undefined_Tok, True)
1895
1896 def _ReadCompoundOrRedir3(self, lex_mode, eof_type, empty_ok):
1897 # type: (lex_mode_t, Id_t, bool) -> word_t
1898 """
1899 Precondition: Looking at the first token of the first word part
1900 Postcondition: Looking at the token after, e.g. space or operator
1901
1902 NOTE: eof_type is necessary because / is a literal, i.e. Lit_Slash, but it
1903 could be an operator delimiting a compound word. Can we change lexer modes
1904 and remove this special case?
1905
1906 Returns either word.Compound or word.Redir
1907 """
1908 w = CompoundWord([])
1909 num_parts = 0
1910 brace_count = 0
1911 done = False
1912 is_triple_quoted = None # type: Optional[BoolParamBox]
1913 saw_redir_left_tok = False
1914
1915 while not done:
1916 self._GetToken()
1917
1918 allow_done = empty_ok or num_parts != 0
1919 if allow_done and self.token_type == eof_type:
1920 done = True # e.g. for ${foo//pat/replace}
1921
1922 # Keywords like "for" are treated like literals
1923 elif self.token_kind in (Kind.Lit, Kind.History, Kind.KW,
1924 Kind.ControlFlow, Kind.BoolUnary,
1925 Kind.BoolBinary):
1926
1927 # Syntax error for { and }
1928 if self.token_type == Id.Lit_LBrace:
1929 brace_count += 1
1930 elif self.token_type == Id.Lit_RBrace:
1931 brace_count -= 1
1932 elif self.token_type == Id.Lit_Dollar:
1933 if self.parse_opts.no_parse_dollar():
1934 if num_parts == 0 and lex_mode == lex_mode_e.ShCommand:
1935 next_byte = self.lexer.ByteLookAhead()
1936 # TODO: switch lexer modes and parse $/d+/. But not ${a:-$/d+/}
1937 if next_byte == '/':
1938 #log('next_byte %r', next_byte)
1939 pass
1940
1941 p_die(
1942 'Literal $ should be quoted like \$ (no_parse_dollar)',
1943 self.cur_token)
1944 elif self.token_type in (Id.Lit_Number, Id.Lit_RedirVarName):
1945 saw_redir_left_tok = True
1946
1947 done = self._MaybeReadWordPart(num_parts == 0, lex_mode,
1948 w.parts)
1949
1950 elif self.token_kind == Kind.VSub:
1951 vsub_token = self.cur_token
1952
1953 part = SimpleVarSub(vsub_token) # type: word_part_t
1954 w.parts.append(part)
1955
1956 elif self.token_kind == Kind.ExtGlob:
1957 # If parse_at, we can take over @( to start @(seq 3)
1958 # Users can also use look at ,(*.py|*.sh)
1959 if (self.parse_opts.parse_at() and
1960 self.token_type == Id.ExtGlob_At and num_parts == 0):
1961 cs_part = self._ReadCommandSub(Id.Left_AtParen,
1962 d_quoted=False)
1963 # RARE mutation of tok.id!
1964 cs_part.left_token.id = Id.Left_AtParen
1965 part = cs_part # for type safety
1966
1967 # Same check as _MaybeReadWordPart. @(seq 3)x is illegal, just like
1968 # a=(one two)x and @arrayfunc(3)x.
1969 self._GetToken()
1970 if self.token_kind not in KINDS_THAT_END_WORDS:
1971 p_die('Unexpected token after @()', self.cur_token)
1972 done = True
1973
1974 else:
1975 if HAVE_FNM_EXTMATCH == 0:
1976 p_die(
1977 "Extended glob won't work without FNM_EXTMATCH support in libc",
1978 self.cur_token)
1979 part = self._ReadExtGlob()
1980 w.parts.append(part)
1981
1982 elif self.token_kind == Kind.BashRegex:
1983 if self.token_type == Id.BashRegex_LParen: # Opening (
1984 part = self._ReadBashRegexGroup()
1985 w.parts.append(part)
1986 else:
1987 assert self.token_type == Id.BashRegex_AllowedInParens
1988 p_die('Invalid token in bash regex', self.cur_token)
1989
1990 elif self.token_kind == Kind.Left:
1991 try_triple_quote = (self.parse_opts.parse_triple_quote() and
1992 lex_mode == lex_mode_e.ShCommand and
1993 num_parts == 0)
1994
1995 # Save allocation
1996 if try_triple_quote:
1997 is_triple_quoted = BoolParamBox(False)
1998
1999 part = self._ReadUnquotedLeftParts(is_triple_quoted)
2000 w.parts.append(part)
2001
2002 # NOT done yet, will advance below
2003 elif self.token_kind == Kind.Right:
2004 # Still part of the word; will be done on the next iter.
2005 if self.token_type == Id.Right_DoubleQuote:
2006 pass
2007 # Never happens, no PushHint for this case.
2008 #elif self.token_type == Id.Right_DollarParen:
2009 # pass
2010 elif self.token_type == Id.Right_Subshell:
2011 # LEXER HACK for (case x in x) ;; esac )
2012 # Rewind before it's used
2013 assert self.next_lex_mode == lex_mode_e.Undefined
2014 if self.lexer.MaybeUnreadOne():
2015 self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
2016 self._SetNext(lex_mode)
2017 done = True
2018 else:
2019 done = True
2020
2021 elif self.token_kind == Kind.Redir:
2022 # Check if the previous token was a possible left_tok to a
2023 # redirect operator, attach it to the word.Redir. And return
2024 # it instead of the CompoundWord.
2025
2026 # &> and &>> don't have a leading descriptor (2 is implied)
2027 if (saw_redir_left_tok and num_parts == 1 and self.token_type
2028 not in (Id.Redir_AndGreat, Id.Redir_AndDGreat)):
2029
2030 self._SetNext(lex_mode)
2031 left_tok = cast(Token, w.parts.pop())
2032 r = word.Redir(left_tok, self.cur_token)
2033 return r # EARLY RETURN
2034
2035 done = True
2036
2037 elif self.token_kind == Kind.Ignored:
2038 done = True
2039
2040 else:
2041 # LEXER HACK for unbalanced case clause. 'case foo in esac' is valid,
2042 # so to test for ESAC, we can read ) before getting a chance to
2043 # PushHint(Id.Op_RParen, Id.Right_CasePat). So here we unread one
2044 # token and do it again.
2045
2046 # We get Id.Op_RParen at top level: case x in x) ;; esac
2047 # We get Id.Eof_RParen inside ComSub: $(case x in x) ;; esac )
2048 if self.token_type in (Id.Op_RParen, Id.Eof_RParen):
2049 # Rewind before it's used
2050 assert self.next_lex_mode == lex_mode_e.Undefined
2051 if self.lexer.MaybeUnreadOne():
2052 if self.token_type == Id.Eof_RParen:
2053 # Redo translation
2054 self.lexer.PushHint(Id.Op_RParen, Id.Eof_RParen)
2055 self._SetNext(lex_mode)
2056
2057 done = True # anything we don't recognize means we're done
2058
2059 if not done:
2060 self._SetNext(lex_mode)
2061 num_parts += 1
2062
2063 if (self.parse_opts.parse_brace() and num_parts > 1 and
2064 brace_count != 0):
2065 # accept { and }, but not foo{
2066 p_die(
2067 'Word has unbalanced { }. Maybe add a space or quote it like \{',
2068 loc.Word(w))
2069
2070 if is_triple_quoted and is_triple_quoted.b and num_parts > 1:
2071 p_die('Unexpected parts after triple quoted string',
2072 loc.WordPart(w.parts[-1]))
2073
2074 if 0:
2075 from _devbuild.gen.syntax_asdl import word_part_str
2076 word_key = ' '.join(word_part_str(p.tag()) for p in w.parts)
2077 WORD_HIST[word_key] += 1
2078
2079 # YSH word restriction
2080 # (r'' u'' b'' are stripped on shopt -s parse_ysh_string)
2081 if self.parse_opts.no_parse_word_join() and not _IsValidYshWord(w):
2082 p_die("Invalid quoted word part in YSH (OILS-ERR-17)",
2083 loc.WordPart(part))
2084
2085 return w
2086
2087 def _ReadArithWord(self):
2088 # type: () -> Optional[word_t]
2089 """ Helper for ReadArithWord() """
2090 self._GetToken()
2091
2092 if self.token_kind == Kind.Unknown:
2093 # e.g. happened during dynamic parsing of unset 'a[$foo]' in gherkin
2094 p_die(
2095 'Unexpected token while parsing arithmetic: %r' %
2096 lexer.TokenVal(self.cur_token), self.cur_token)
2097
2098 elif self.token_kind == Kind.Eof:
2099 return self.cur_token
2100
2101 elif self.token_kind == Kind.Ignored:
2102 # Space should be ignored.
2103 self._SetNext(lex_mode_e.Arith)
2104 return None
2105
2106 elif self.token_kind in (Kind.Arith, Kind.Right):
2107 # Id.Right_DollarDParen IS just a normal token, handled by ArithParser
2108 self._SetNext(lex_mode_e.Arith)
2109 return self.cur_token
2110
2111 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub):
2112 return self._ReadCompoundWord(lex_mode_e.Arith)
2113
2114 else:
2115 raise AssertionError(self.cur_token)
2116
2117 def _ReadWord(self, word_mode):
2118 # type: (lex_mode_t) -> Optional[word_t]
2119 """Helper function for ReadWord()."""
2120
2121 # Change the pseudo lexer mode to a real lexer mode
2122 if word_mode == lex_mode_e.ShCommandFakeBrack:
2123 lex_mode = lex_mode_e.ShCommand
2124 else:
2125 lex_mode = word_mode
2126
2127 self._GetToken()
2128
2129 if self.token_kind == Kind.Eof:
2130 # No advance
2131 return self.cur_token
2132
2133 elif self.token_kind == Kind.Redir:
2134 self._SetNext(lex_mode)
2135 # This is >out -- 3>out is handled below
2136 return word.Redir(None, self.cur_token)
2137
2138 # Allow Arith for ) at end of for loop?
2139 elif self.token_kind in (Kind.Op, Kind.Arith):
2140 self._SetNext(lex_mode)
2141
2142 # Newlines are complicated. See 3x2 matrix in the comment about
2143 # self.multiline and self.newline_state above.
2144 if self.token_type == Id.Op_Newline:
2145 if self.multiline:
2146 if self.newline_state > 1:
2147 # This points at a blank line, but at least it gives the line number
2148 p_die('Invalid blank line in multiline mode',
2149 self.cur_token)
2150 return None
2151
2152 if self.returned_newline: # skip
2153 return None
2154
2155 return self.cur_token
2156
2157 elif self.token_kind == Kind.Right:
2158 if self.token_type not in (Id.Right_Subshell, Id.Right_ShFunction,
2159 Id.Right_CasePat, Id.Right_Initializer):
2160 raise AssertionError(self.cur_token)
2161
2162 self._SetNext(lex_mode)
2163 return self.cur_token
2164
2165 elif self.token_kind in (Kind.Ignored, Kind.WS):
2166 self._SetNext(lex_mode)
2167 return None
2168
2169 else:
2170 assert self.token_kind in (Kind.VSub, Kind.Lit, Kind.History,
2171 Kind.Left, Kind.KW, Kind.ControlFlow,
2172 Kind.BoolUnary, Kind.BoolBinary,
2173 Kind.ExtGlob,
2174 Kind.BashRegex), 'Unhandled token kind'
2175
2176 if (word_mode == lex_mode_e.ShCommandFakeBrack and
2177 self.parse_opts.parse_bracket() and
2178 self.token_type == Id.Lit_LBracket):
2179 # Change [ from Kind.Lit -> Kind.Op
2180 # So CommandParser can treat
2181 # assert [42 === x]
2182 # like
2183 # json write (x)
2184 bracket_word = self.cur_token
2185 bracket_word.id = Id.Op_LBracket
2186
2187 self._SetNext(lex_mode)
2188 return bracket_word
2189
2190 # We're beginning a word. If we see Id.Lit_Pound, change to
2191 # lex_mode_e.Comment and read until end of line.
2192 if self.token_type == Id.Lit_Pound:
2193 self._SetNext(lex_mode_e.Comment)
2194 self._GetToken()
2195
2196 # NOTE: The # could be the last character in the file. It can't be
2197 # Eof_{RParen,Backtick} because #) and #` are comments.
2198 assert self.token_type in (Id.Ignored_Comment, Id.Eof_Real), \
2199 self.cur_token
2200
2201 # The next iteration will go into Kind.Ignored and set lex state to
2202 # lex_mode_e.ShCommand/etc.
2203 return None # tell ReadWord() to try again after comment
2204
2205 elif self.token_type == Id.Lit_TPound: ### doc comment
2206 self._SetNext(lex_mode_e.Comment)
2207 self._GetToken()
2208
2209 if self.token_type == Id.Ignored_Comment and self.emit_doc_token:
2210 return self.cur_token
2211
2212 return None # tell ReadWord() to try again after comment
2213
2214 else:
2215 # r'' u'' b'' at the beginning of a word
2216 if (self.token_type == Id.Lit_Chars and
2217 self.lexer.LookAheadOne(
2218 lex_mode_e.ShCommand) == Id.Left_SingleQuote):
2219
2220 # When shopt -s parse_ysh_string:
2221 # echo r'hi' is like echo 'hi'
2222 #
2223 # echo u'\u{3bc}' b'\yff' works
2224
2225 tok = self.cur_token
2226 if self.parse_opts.parse_ysh_string():
2227 if lexer.TokenEquals(tok, 'r'):
2228 left_id = Id.Left_RSingleQuote
2229 elif lexer.TokenEquals(tok, 'u'):
2230 left_id = Id.Left_USingleQuote
2231 elif lexer.TokenEquals(tok, 'b'):
2232 left_id = Id.Left_BSingleQuote
2233 else:
2234 left_id = Id.Undefined_Tok
2235
2236 if left_id != Id.Undefined_Tok:
2237 # skip the r, and then 'foo' will be read as normal
2238 self._SetNext(lex_mode_e.ShCommand)
2239
2240 self._GetToken()
2241 assert self.token_type == Id.Left_SingleQuote, self.token_type
2242
2243 # Read the word in a different lexer mode
2244 return self._ReadYshSingleQuoted(left_id)
2245
2246 return self._ReadCompoundOrRedir(lex_mode)
2247
2248 def ParseVarRef(self):
2249 # type: () -> BracedVarSub
2250 """DYNAMIC parsing of what's inside ${!ref}
2251
2252 # Same as VarOf production
2253 VarRefExpr = VarOf EOF
2254 """
2255 self._SetNext(lex_mode_e.VSub_1)
2256
2257 self._GetToken()
2258 if self.token_kind != Kind.VSub:
2259 p_die('Expected var name', self.cur_token)
2260
2261 part = self._ParseVarOf()
2262 # NOTE: no ${ } means no part.left and part.right
2263 part.left = part.name_tok # cheat to make test pass
2264 part.right = part.name_tok
2265
2266 self._GetToken()
2267 if self.token_type != Id.Eof_Real:
2268 p_die('Expected end of var ref expression', self.cur_token)
2269 return part
2270
2271 def LookPastSpace(self):
2272 # type: () -> Id_t
2273 """Look ahead to the next token.
2274
2275 For the CommandParser to recognize
2276 array= (1 2 3)
2277 YSH for ( versus bash for ((
2278 YSH if ( versus if test
2279 YSH while ( versus while test
2280 YSH bare assignment 'grep =' versus 'grep foo'
2281 """
2282 assert self.token_type != Id.Undefined_Tok
2283 if self.cur_token.id == Id.WS_Space:
2284 id_ = self.lexer.LookPastSpace(lex_mode_e.ShCommand)
2285 else:
2286 id_ = self.cur_token.id
2287 return id_
2288
2289 def LookAheadDParens(self, shift_back=0):
2290 # type: (int) -> bool
2291 """Special lookahead for (( )), to make sure it's an arithmetic
2292 expression (i.e. that the closing parens are a single token, not
2293 separated by anything).
2294 """
2295 assert self.token_type in (Id.Op_DLeftParen, Id.Left_DollarDParen)
2296
2297 return self.lexer.LookAheadDParens(shift_back)
2298
2299 def LookAheadFuncParens(self):
2300 # type: () -> bool
2301 """Special lookahead for f( ) { echo hi; } to check for ( )"""
2302 assert self.token_type != Id.Undefined_Tok
2303
2304 # We have to handle 2 cases because we buffer a token
2305 if self.cur_token.id == Id.Op_LParen: # saw funcname(
2306 return self.lexer.LookAheadFuncParens(1) # go back one char
2307
2308 elif self.cur_token.id == Id.WS_Space: # saw funcname WHITESPACE
2309 return self.lexer.LookAheadFuncParens(0)
2310
2311 else:
2312 return False
2313
2314 def ReadWord(self, word_mode):
2315 # type: (lex_mode_t) -> word_t
2316 """Read the next word, using the given lexer mode.
2317
2318 This is a stateful wrapper for the stateless _ReadWord function.
2319 """
2320 assert word_mode in (lex_mode_e.ShCommand,
2321 lex_mode_e.ShCommandFakeBrack,
2322 lex_mode_e.DBracket, lex_mode_e.BashRegex)
2323
2324 if self.buffered_word: # For integration with pgen2
2325 w = self.buffered_word
2326 self.buffered_word = None
2327 else:
2328 while True:
2329 w = self._ReadWord(word_mode)
2330 if w is not None:
2331 break
2332
2333 self.returned_newline = (word_.CommandId(w) == Id.Op_Newline)
2334 return w
2335
2336 def ReadArithWord(self):
2337 # type: () -> word_t
2338 while True:
2339 w = self._ReadArithWord()
2340 if w is not None:
2341 break
2342 return w
2343
2344 def ReadHereDocBody(self, parts):
2345 # type: (List[word_part_t]) -> None
2346 """
2347 A here doc is like a double quoted context, except " and \" aren't special.
2348 """
2349 self._ReadLikeDQ(None, False, parts)
2350 # Returns nothing
2351
2352 def ReadForPlugin(self):
2353 # type: () -> CompoundWord
2354 """For $PS1, $PS4, etc.
2355
2356 This is just like reading a here doc line. "\n" is allowed, as
2357 well as the typical substitutions ${x} $(echo hi) $((1 + 2)).
2358 """
2359 w = CompoundWord([])
2360 self._ReadLikeDQ(None, False, w.parts)
2361 return w
2362
2363 def EmitDocToken(self, b):
2364 # type: (bool) -> None
2365 self.emit_doc_token = b
2366
2367 def Multiline(self, b):
2368 # type: (bool) -> None
2369 self.multiline = b
2370
2371
2372if 0:
2373 import collections
2374 WORD_HIST = collections.Counter()
2375
2376# vim: sw=4