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, is_here_doc=False):
1071 # type: (Optional[Token], bool, List[word_part_t], bool) -> 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 if ch == "\"" and is_here_doc:
1098 # in here docs \" should not be escaped, staying as literal characters
1099 part = Token(
1100 Id.Lit_Chars,
1101 tok.length,
1102 tok.col, tok.line,
1103 tok.tval
1104 )
1105 else:
1106 part = word_part.EscapedLiteral(tok,
1107 ch) # type: word_part_t
1108 else:
1109 if self.token_type == Id.Lit_BadBackslash:
1110 # echo "\z" is OK in shell, but 'x = "\z" is a syntax error in
1111 # YSH.
1112 # Slight hole: We don't catch 'x = ${undef:-"\z"} because of the
1113 # recursion (unless no_parse_backslash)
1114 if (is_ysh_expr or
1115 self.parse_opts.no_parse_backslash()):
1116 p_die(
1117 "Invalid char escape in double quoted string (OILS-ERR-12)",
1118 self.cur_token)
1119 elif self.token_type == Id.Lit_Dollar:
1120 if is_ysh_expr or self.parse_opts.no_parse_dollar():
1121 p_die("Literal $ should be quoted like \$",
1122 self.cur_token)
1123
1124 part = self.cur_token
1125 out_parts.append(part)
1126
1127 elif self.token_kind == Kind.Left:
1128 if self.token_type == Id.Left_Backtick and is_ysh_expr:
1129 p_die("Backtick should be $(cmd) or \\` (OILS-ERR-18)",
1130 self.cur_token)
1131
1132 part = self._ReadDoubleQuotedLeftParts()
1133 out_parts.append(part)
1134
1135 elif self.token_kind == Kind.VSub:
1136 tok = self.cur_token
1137 part = SimpleVarSub(tok)
1138 out_parts.append(part)
1139 # NOTE: parsing "$f(x)" would BREAK CODE. Could add a more for it
1140 # later.
1141
1142 elif self.token_kind == Kind.Right:
1143 assert self.token_type == Id.Right_DoubleQuote, self.token_type
1144 if left_token:
1145 num_end_tokens += 1
1146
1147 # In a here doc, the right quote is literal!
1148 out_parts.append(self.cur_token)
1149
1150 elif self.token_kind == Kind.Eof:
1151 if left_token:
1152 p_die(
1153 'Unexpected EOF reading double-quoted string that began here',
1154 left_token)
1155 else: # here docs will have an EOF in their token stream
1156 break
1157
1158 else:
1159 raise AssertionError(self.cur_token)
1160
1161 if self.token_kind != Kind.Right:
1162 num_end_tokens = 0 # """ must be CONSECUTIVE
1163
1164 if expected_end_tokens == 1:
1165 out_parts.pop()
1166 elif expected_end_tokens == 3:
1167 out_parts.pop()
1168 out_parts.pop()
1169 out_parts.pop()
1170
1171 # Remove space from """ in both expression mode and command mode
1172 if (left_token and left_token.id
1173 in (Id.Left_TDoubleQuote, Id.Left_DollarTDoubleQuote)):
1174 word_compile.RemoveLeadingSpaceDQ(out_parts)
1175
1176 # Return nothing, since we appended to 'out_parts'
1177
1178 def _ReadDoubleQuoted(self, left_token):
1179 # type: (Token) -> DoubleQuoted
1180 """Helper function for "hello $name".
1181
1182 Args:
1183 eof_type: for stopping at }, Id.Lit_RBrace
1184 here_doc: Whether we are reading in a here doc context
1185
1186 Also ${foo%%a b c} # treat this as double quoted. until you hit
1187 """
1188 parts = [] # type: List[word_part_t]
1189 self._ReadLikeDQ(left_token, False, parts)
1190
1191 right_quote = self.cur_token
1192 return DoubleQuoted(left_token, parts, right_quote)
1193
1194 def ReadDoubleQuoted(self, left_token, parts):
1195 # type: (Token, List[word_part_t]) -> Token
1196 """For expression mode.
1197
1198 Read var x = "${dir:-}/$name"; etc.
1199 """
1200 self._ReadLikeDQ(left_token, True, parts)
1201 return self.cur_token
1202
1203 def _ReadCommandSub(self, left_id, d_quoted=False):
1204 # type: (Id_t, bool) -> CommandSub
1205 """
1206 NOTE: This is not in the grammar, because word parts aren't in the grammar!
1207
1208 command_sub = '$(' command_list ')'
1209 | '@(' command_list ')'
1210 | '<(' command_list ')'
1211 | '>(' command_list ')'
1212 | ` command_list `
1213 """
1214 left_token = self.cur_token
1215
1216 # Set the lexer in a state so ) becomes the EOF token.
1217 if left_id in (Id.Left_DollarParen, Id.Left_AtParen, Id.Left_ProcSubIn,
1218 Id.Left_ProcSubOut):
1219 self._SetNext(lex_mode_e.ShCommand) # advance past $( etc.
1220
1221 right_id = Id.Eof_RParen
1222 self.lexer.PushHint(Id.Op_RParen, right_id)
1223 c_parser = self.parse_ctx.MakeParserForCommandSub(
1224 self.line_reader, self.lexer, right_id)
1225 # NOTE: This doesn't use something like main_loop because we don't want
1226 # to interleave parsing and execution! Unlike 'source' and 'eval'.
1227 node = c_parser.ParseCommandSub()
1228
1229 right_token = c_parser.w_parser.cur_token
1230
1231 elif left_id == Id.Left_Backtick and self.parse_ctx.do_lossless:
1232 # NOTE: This is an APPROXIMATE solution for translation ONLY. See
1233 # test/osh2oil.
1234
1235 right_id = Id.Eof_Backtick
1236 self.lexer.PushHint(Id.Left_Backtick, right_id)
1237 c_parser = self.parse_ctx.MakeParserForCommandSub(
1238 self.line_reader, self.lexer, right_id)
1239 node = c_parser.ParseCommandSub()
1240 right_token = c_parser.w_parser.cur_token
1241
1242 elif left_id == Id.Left_Backtick:
1243 if self.parse_opts.no_parse_backticks():
1244 p_die(
1245 'Backtick should be $(cmd) or \\` (no_parse_backticks, OILS-ERR-18)',
1246 left_token)
1247
1248 self._SetNext(lex_mode_e.Backtick) # advance past `
1249
1250 parts = [] # type: List[str]
1251 while True:
1252 self._GetToken()
1253 #log("TOK %s", self.cur_token)
1254
1255 if self.token_type == Id.Backtick_Quoted:
1256 # Remove leading \
1257 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1258
1259 elif self.token_type == Id.Backtick_DoubleQuote:
1260 # Compatibility: If backticks are double quoted, then double quotes
1261 # within them have to be \"
1262 # Shells aren't smart enough to match nested " and ` quotes (but OSH
1263 # is)
1264 if d_quoted:
1265 # Remove leading \
1266 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1267 else:
1268 parts.append(lexer.TokenVal(self.cur_token))
1269
1270 elif self.token_type == Id.Backtick_Other:
1271 parts.append(lexer.TokenVal(self.cur_token))
1272
1273 elif self.token_type == Id.Backtick_Right:
1274 break
1275
1276 elif self.token_type == Id.Eof_Real:
1277 # Note: this parse error is in the ORIGINAL context. No code_str yet.
1278 p_die('Unexpected EOF while looking for closing backtick',
1279 left_token)
1280
1281 else:
1282 raise AssertionError(self.cur_token)
1283
1284 self._SetNext(lex_mode_e.Backtick)
1285
1286 # Calculate right SPID on CommandSub BEFORE re-parsing.
1287 right_token = self.cur_token
1288
1289 code_str = ''.join(parts)
1290 #log('code %r', code_str)
1291
1292 # Save lines into a new, temporary arena, so SnipCodeBlock() isn't
1293 # messed up. Note: This is similar to how we parse aliases in
1294 # osh/cmd_parse.py. It won't have the same location info as
1295 # MakeParserForCommandSub(), because the reader is different.
1296 arena = alloc.Arena()
1297 # TODO: arena.PushSource()?
1298
1299 line_reader = reader.StringLineReader(code_str, arena)
1300 c_parser = self.parse_ctx.MakeOshParser(line_reader)
1301 src = source.Reparsed('backticks', left_token, right_token)
1302 with alloc.ctx_SourceCode(arena, src):
1303 node = c_parser.ParseCommandSub()
1304
1305 else:
1306 raise AssertionError(left_id)
1307
1308 return CommandSub(left_token, node, right_token)
1309
1310 def _ReadExprSub(self, lex_mode):
1311 # type: (lex_mode_t) -> ExprSub
1312 """$[d->key] $[obj.method()] etc."""
1313 left_token = self.cur_token
1314
1315 self._SetNext(lex_mode_e.Expr)
1316 enode, right_token = self.parse_ctx.ParseYshExpr(
1317 self.lexer, grammar_nt.ysh_expr_sub)
1318
1319 self._SetNext(lex_mode) # Move past ]
1320 return ExprSub(left_token, enode, right_token)
1321
1322 def ParseVarDecl(self, kw_token):
1323 # type: (Token) -> VarDecl
1324 """
1325 oil_var_decl: name_type_list '=' testlist end_stmt
1326
1327 Note that assignments must end with \n ; } or EOF. Unlike shell
1328 assignments, we disallow:
1329
1330 var x = 42 | wc -l
1331 var x = 42 && echo hi
1332 """
1333 self._SetNext(lex_mode_e.Expr)
1334 enode, last_token = self.parse_ctx.ParseVarDecl(kw_token, self.lexer)
1335 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1336 # wants
1337 if last_token.id == Id.Op_RBrace:
1338 last_token.id = Id.Lit_RBrace
1339
1340 # Let the CommandParser see the Op_Semi or Op_Newline.
1341 self.buffered_word = last_token
1342 self._SetNext(lex_mode_e.ShCommand) # always back to this
1343 return enode
1344
1345 def ParseMutation(self, kw_token, var_checker):
1346 # type: (Token, VarChecker) -> Mutation
1347 """
1348 setvar i = 42
1349 setvar i += 1
1350 setvar a[i] = 42
1351 setvar a[i] += 1
1352 setvar d.key = 42
1353 setvar d.key += 1
1354 """
1355 self._SetNext(lex_mode_e.Expr)
1356 enode, last_token = self.parse_ctx.ParseMutation(kw_token, self.lexer)
1357 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1358 # wants
1359 if last_token.id == Id.Op_RBrace:
1360 last_token.id = Id.Lit_RBrace
1361
1362 for lhs in enode.lhs:
1363 UP_lhs = lhs
1364 with tagswitch(lhs) as case:
1365 if case(y_lhs_e.Var):
1366 lhs = cast(Token, UP_lhs)
1367 var_checker.Check(kw_token.id, lexer.LazyStr(lhs), lhs)
1368
1369 # Note: this does not cover cases like
1370 # setvar (a[0])[1] = v
1371 # setvar (d.key).other = v
1372 # This leaks into catching all typos statically, which may be
1373 # possible if 'use' makes all names explicit.
1374 elif case(y_lhs_e.Subscript):
1375 lhs = cast(Subscript, UP_lhs)
1376 if lhs.obj.tag() == expr_e.Var:
1377 v = cast(expr.Var, lhs.obj)
1378 var_checker.Check(kw_token.id, v.name, v.left)
1379
1380 elif case(y_lhs_e.Attribute):
1381 lhs = cast(Attribute, UP_lhs)
1382 if lhs.obj.tag() == expr_e.Var:
1383 v = cast(expr.Var, lhs.obj)
1384 var_checker.Check(kw_token.id, v.name, v.left)
1385
1386 # Let the CommandParser see the Op_Semi or Op_Newline.
1387 self.buffered_word = last_token
1388 self._SetNext(lex_mode_e.ShCommand) # always back to this
1389 return enode
1390
1391 def ParseBareDecl(self):
1392 # type: () -> expr_t
1393 """
1394 x = {name: val}
1395 """
1396 self._SetNext(lex_mode_e.Expr)
1397 self._GetToken()
1398 enode, last_token = self.parse_ctx.ParseYshExpr(
1399 self.lexer, grammar_nt.command_expr)
1400 if last_token.id == Id.Op_RBrace:
1401 last_token.id = Id.Lit_RBrace
1402 self.buffered_word = last_token
1403 self._SetNext(lex_mode_e.ShCommand)
1404 return enode
1405
1406 def ParseYshExprForCommand(self):
1407 # type: () -> expr_t
1408
1409 # Fudge for this case
1410 # for x in(y) {
1411 # versus
1412 # for x in (y) {
1413 #
1414 # In the former case, ReadWord on 'in' puts the lexer past (.
1415 # Also see LookPastSpace in CommandParers.
1416 # A simpler solution would be nicer.
1417
1418 if self.token_type == Id.Op_LParen:
1419 self.lexer.MaybeUnreadOne()
1420
1421 enode, _ = self.parse_ctx.ParseYshExpr(self.lexer, grammar_nt.ysh_expr)
1422
1423 self._SetNext(lex_mode_e.ShCommand)
1424 return enode
1425
1426 def ParseCommandExpr(self):
1427 # type: () -> expr_t
1428 """
1429 = 1+2
1430 """
1431 enode, last_token = self.parse_ctx.ParseYshExpr(
1432 self.lexer, grammar_nt.command_expr)
1433
1434 # In some cases, such as the case statement, we expect *the lexer* to be
1435 # pointing at the token right after the expression. But the expression
1436 # parser must have read to the `last_token`. Unreading places the lexer
1437 # back in the expected state. Ie:
1438 #
1439 # case (x) { case (x) {
1440 # (else) { = x } (else) { = x }
1441 # ^ The lexer is here ^ Unread to here
1442 # } }
1443 assert last_token.id in (Id.Op_Newline, Id.Eof_Real, Id.Op_Semi,
1444 Id.Op_RBrace), last_token
1445 if last_token.id != Id.Eof_Real:
1446 # Eof_Real is the only token we cannot unread
1447 self.lexer.MaybeUnreadOne()
1448
1449 return enode
1450
1451 def ParseProc(self, node):
1452 # type: (Proc) -> None
1453
1454 # proc name-with-hyphens() must be accepted
1455 self._SetNext(lex_mode_e.ShCommand)
1456 self._GetToken()
1457 # example: 'proc f[' gets you Lit_ArrayLhsOpen
1458 if self.token_type != Id.Lit_Chars:
1459 p_die('Invalid proc name %s' % ui.PrettyToken(self.cur_token),
1460 self.cur_token)
1461
1462 # TODO: validate this more. Disallow proc 123 { }, which isn't disallowed
1463 # for shell functions. Similar to IsValidVarName().
1464 node.name = self.cur_token
1465
1466 last_token = self.parse_ctx.ParseProc(self.lexer, node)
1467
1468 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1469 assert last_token.id == Id.Op_LBrace
1470 last_token.id = Id.Lit_LBrace
1471 self.buffered_word = last_token
1472
1473 self._SetNext(lex_mode_e.ShCommand)
1474
1475 def ParseFunc(self, node):
1476 # type: (Func) -> None
1477 last_token = self.parse_ctx.ParseFunc(self.lexer, node)
1478
1479 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1480 assert last_token.id == Id.Op_LBrace
1481 last_token.id = Id.Lit_LBrace
1482 self.buffered_word = last_token
1483
1484 self._SetNext(lex_mode_e.ShCommand)
1485
1486 def ParseYshCasePattern(self):
1487 # type: () -> Tuple[pat_t, Token]
1488 pat, left_tok, last_token = self.parse_ctx.ParseYshCasePattern(
1489 self.lexer)
1490
1491 if last_token.id == Id.Op_LBrace:
1492 last_token.id = Id.Lit_LBrace
1493 self.buffered_word = last_token
1494
1495 return pat, left_tok
1496
1497 def NewlineOkForYshCase(self):
1498 # type: () -> Id_t
1499 """Check for optional newline and consume it.
1500
1501 This is a special case of `_NewlineOk` which fixed some "off-by-one" issues
1502 which crop up while parsing Ysh Case Arms. For more details, see
1503 #oil-dev > Progress On YSH Case Grammar on zulip.
1504
1505 Returns a token id which is filled with the choice of
1506
1507 word { echo word }
1508 (3) { echo expr }
1509 /e/ { echo eggex }
1510 } # right brace
1511 """
1512 while True:
1513 next_id = self.lexer.LookAheadOne(lex_mode_e.Expr)
1514
1515 # Cannot lookahead past lines
1516 if next_id == Id.Unknown_Tok:
1517 if not self.lexer.MoveToNextLine(): # Try to move to next line
1518 break # EOF
1519 continue
1520
1521 next_kind = consts.GetKind(next_id)
1522 if next_id != Id.Op_Newline and next_kind != Kind.Ignored:
1523 break
1524
1525 self.lexer.Read(lex_mode_e.Expr)
1526
1527 if next_id in (Id.Op_RBrace, Id.Op_LParen, Id.Arith_Slash):
1528 self._SetNext(lex_mode_e.Expr) # Continue in expression mode
1529 else:
1530 # Consume the trailing Op_Newline
1531 self._SetNext(lex_mode_e.ShCommand)
1532 self._GetToken()
1533
1534 return next_id
1535
1536 def _ReadArithExpr(self, end_id):
1537 # type: (Id_t) -> arith_expr_t
1538 """Read and parse an arithmetic expression in various contexts.
1539
1540 $(( 1+2 ))
1541 (( a=1+2 ))
1542 ${a[ 1+2 ]}
1543 ${a : 1+2 : 1+2}
1544
1545 See tests/arith-context.test.sh for ambiguous cases.
1546
1547 ${a[a[0]]} is valid # VS_RBRACKET vs Id.Arith_RBracket
1548
1549 ${s : a<b?0:1 : 1} # VS_COLON vs Id.Arith_Colon
1550
1551 See the assertion in ArithParser.Parse() -- unexpected extra input.
1552 """
1553 # calls self.ReadWord(lex_mode_e.Arith)
1554 anode = self.a_parser.Parse()
1555 cur_id = self.a_parser.CurrentId()
1556 if end_id != Id.Undefined_Tok and cur_id != end_id:
1557 p_die(
1558 'Unexpected token after arithmetic expression (%s != %s)' %
1559 (ui.PrettyId(cur_id), ui.PrettyId(end_id)),
1560 loc.Word(self.a_parser.cur_word))
1561 return anode
1562
1563 def _ReadArithSub(self, end_id=Id.Arith_RParen):
1564 # type: (Id_t) -> word_part.ArithSub
1565 """Read an arith substitution, which contains an arith expression, e.g.
1566
1567 $((a + 1)).
1568 """
1569 assert end_id in (Id.Arith_RParen, Id.Arith_RBracket)
1570
1571 left_tok = self.cur_token
1572
1573 # The second one needs to be disambiguated in stuff like stuff like:
1574 # $(echo $(( 1+2 )) )
1575 self.lexer.PushHint(Id.Op_RParen, Id.Right_DollarDParen)
1576
1577 # NOTE: To disambiguate $(( as arith sub vs. command sub and subshell, we
1578 # could save the lexer/reader state here, and retry if the arithmetic parse
1579 # fails. But we can almost always catch this at parse time. There could
1580 # be some exceptions like:
1581 # $((echo * foo)) # looks like multiplication
1582 # $((echo / foo)) # looks like division
1583
1584 # $(( )) is valid
1585 anode = arith_expr.EmptyZero # type: arith_expr_t
1586
1587 self._NextNonSpace()
1588 if self.token_type != Id.Arith_RParen:
1589 anode = self._ReadArithExpr(end_id)
1590
1591 self._SetNext(lex_mode_e.ShCommand)
1592
1593 if end_id == Id.Arith_RParen:
1594 # Ensure we get closing ) if we are looking for double ))
1595 # (In backwards compat mode, ] can also be the closing bracket, and
1596 # it would already be the current token, no need to skip further
1597 self._GetToken()
1598 if self.token_type != Id.Right_DollarDParen:
1599 p_die('Expected second ) to end arith sub', self.cur_token)
1600
1601 right_tok = self.cur_token
1602 return word_part.ArithSub(left_tok, anode, right_tok)
1603
1604 def ReadDParen(self):
1605 # type: () -> Tuple[arith_expr_t, Token]
1606 """Read ((1+ 2)) -- command context.
1607
1608 We're using the word parser because it's very similar to _ReadArithExpr
1609 above.
1610
1611 This also returns the terminating Id.Op_DRightParen token for location
1612 info.
1613 """
1614 # (( )) is valid
1615 anode = arith_expr.EmptyZero # type: arith_expr_t
1616
1617 self.lexer.PushHint(Id.Op_RParen, Id.Op_DRightParen)
1618
1619 self._NextNonSpace()
1620 if self.token_type != Id.Arith_RParen:
1621 anode = self._ReadArithExpr(Id.Arith_RParen)
1622
1623 self._SetNext(lex_mode_e.ShCommand)
1624
1625 # Ensure we get the second )
1626 self._GetToken()
1627 right = self.cur_token
1628 if right.id != Id.Op_DRightParen:
1629 p_die('Expected second ) to end arith statement', right)
1630
1631 self._SetNext(lex_mode_e.ShCommand)
1632
1633 return anode, right
1634
1635 def _NextNonSpace(self):
1636 # type: () -> None
1637 """Advance in lex_mode_e.Arith until non-space token.
1638
1639 Same logic as _ReadWord, but used in
1640 $(( ))
1641 (( ))
1642 for (( ))
1643
1644 You can read self.token_type after this, without calling _GetToken.
1645 """
1646 while True:
1647 self._SetNext(lex_mode_e.Arith)
1648 self._GetToken()
1649 if self.token_kind not in (Kind.Ignored, Kind.WS):
1650 break
1651
1652 def ReadForExpression(self):
1653 # type: () -> command.ForExpr
1654 """Read ((i=0; i<5; ++i)) -- part of command context."""
1655 self._NextNonSpace() # skip over ((
1656 cur_id = self.token_type # for end of arith expressions
1657
1658 if cur_id == Id.Arith_Semi: # for (( ; i < 10; i++ ))
1659 init_node = arith_expr.EmptyZero # type: arith_expr_t
1660 else:
1661 init_node = self.a_parser.Parse()
1662 cur_id = self.a_parser.CurrentId()
1663 self._NextNonSpace()
1664
1665 # It's odd to keep track of both cur_id and self.token_type in this
1666 # function, but it works, and is tested in 'test/parse_error.sh
1667 # arith-integration'
1668 if cur_id != Id.Arith_Semi: # for (( x=0 b; ... ))
1669 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1670
1671 self._GetToken()
1672 cur_id = self.token_type
1673
1674 if cur_id == Id.Arith_Semi: # for (( ; ; i++ ))
1675 # empty condition is TRUE
1676 cond_node = arith_expr.EmptyOne # type: arith_expr_t
1677 else:
1678 cond_node = self.a_parser.Parse()
1679 cur_id = self.a_parser.CurrentId()
1680
1681 if cur_id != Id.Arith_Semi: # for (( x=0; x<5 b ))
1682 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1683
1684 self._NextNonSpace()
1685 if self.token_type == Id.Arith_RParen: # for (( ; ; ))
1686 update_node = arith_expr.EmptyZero # type: arith_expr_t
1687 else:
1688 update_node = self._ReadArithExpr(Id.Arith_RParen)
1689
1690 self._NextNonSpace()
1691 if self.token_type != Id.Arith_RParen:
1692 p_die('Expected ) to end for loop expression', self.cur_token)
1693 self._SetNext(lex_mode_e.ShCommand)
1694
1695 # redirects is None, will be assigned in CommandEvaluator
1696 node = command.ForExpr.CreateNull()
1697 node.init = init_node
1698 node.cond = cond_node
1699 node.update = update_node
1700 return node
1701
1702 def _ReadArrayLiteral(self):
1703 # type: () -> word_part_t
1704 """a=(1 2 3)
1705
1706 TODO: See osh/cmd_parse.py:164 for Id.Lit_ArrayLhsOpen, for a[x++]=1
1707
1708 We want:
1709
1710 A=(['x']=1 ["x"]=2 [$x$y]=3)
1711
1712 Maybe allow this as a literal string? Because I think I've seen it before?
1713 Or maybe force people to patch to learn the rule.
1714
1715 A=([x]=4)
1716
1717 Starts with Lit_Other '[', and then it has Lit_ArrayLhsClose
1718 Maybe enforce that ALL have keys or NONE of have keys.
1719 """
1720 self._SetNext(lex_mode_e.ShCommand) # advance past (
1721 self._GetToken()
1722 if self.cur_token.id != Id.Op_LParen:
1723 p_die('Expected ( after =', self.cur_token)
1724 left_token = self.cur_token
1725 right_token = None # type: Token
1726
1727 # MUST use a new word parser (with same lexer).
1728 w_parser = self.parse_ctx.MakeWordParser(self.lexer, self.line_reader)
1729 words = [] # type: List[CompoundWord]
1730 done = False
1731 while not done:
1732 w = w_parser.ReadWord(lex_mode_e.ShCommand)
1733 with tagswitch(w) as case:
1734 if case(word_e.Operator):
1735 tok = cast(Token, w)
1736 if tok.id == Id.Right_Initializer:
1737 right_token = tok
1738 done = True # can't use break here
1739 # Unlike command parsing, array parsing allows embedded \n.
1740 elif tok.id == Id.Op_Newline:
1741 continue
1742 else:
1743 p_die('Unexpected token in array literal', loc.Word(w))
1744
1745 elif case(word_e.Compound):
1746 words.append(cast(CompoundWord, w))
1747
1748 else:
1749 raise AssertionError()
1750
1751 initializer_words = [] # type: List[InitializerWord_t]
1752 for w in words:
1753 pair = word_.DetectAssocPair(w)
1754 if pair is not None:
1755 word_.TildeDetectAssign(pair.value) # pair.value is modified
1756 initializer_words.append(pair)
1757 else:
1758 w2 = braces.BraceDetect(w) # type: word_t
1759 if w2 is None:
1760 w2 = w
1761 w3 = word_.TildeDetect(w2) # type: word_t
1762 if w3 is None:
1763 w3 = w2
1764 initializer_words.append(InitializerWord.ArrayWord(w3))
1765
1766 # invariant List?
1767 return word_part.InitializerLiteral(left_token, initializer_words,
1768 right_token)
1769
1770 def ParseProcCallArgs(self, start_symbol):
1771 # type: (int) -> ArgList
1772 """ json write (x) """
1773 self.lexer.MaybeUnreadOne()
1774
1775 arg_list = ArgList.CreateNull(alloc_lists=True)
1776 arg_list.left = self.cur_token
1777 self.parse_ctx.ParseProcCallArgs(self.lexer, arg_list, start_symbol)
1778 return arg_list
1779
1780 def _MaybeReadWordPart(self, is_first, lex_mode, parts):
1781 # type: (bool, lex_mode_t, List[word_part_t]) -> bool
1782 """Helper for _ReadCompoundWord3."""
1783 done = False
1784
1785 if self.token_type == Id.Lit_EscapedChar:
1786 tok = self.cur_token
1787 assert tok.length == 2
1788 ch = lexer.TokenSliceLeft(tok, 1)
1789 if self.parse_opts.no_parse_backslash():
1790 if not pyutil.IsValidCharEscape(ch):
1791 p_die('Invalid char escape in unquoted word (OILS-ERR-13)',
1792 self.cur_token)
1793
1794 part = word_part.EscapedLiteral(self.cur_token,
1795 ch) # type: word_part_t
1796 else:
1797 part = self.cur_token
1798
1799 if is_first and self.token_type == Id.Lit_VarLike: # foo=
1800 parts.append(part)
1801 # Unfortunately it's awkward to pull the check for a=(1 2) up to
1802 # _ReadWord.
1803 next_id = self.lexer.LookPastSpace(lex_mode)
1804 if next_id == Id.Op_LParen:
1805 self.lexer.PushHint(Id.Op_RParen, Id.Right_Initializer)
1806 part2 = self._ReadArrayLiteral()
1807 parts.append(part2)
1808
1809 # Array literal must be the last part of the word.
1810 self._SetNext(lex_mode)
1811 self._GetToken()
1812 # EOF, whitespace, newline, Right_Subshell
1813 if self.token_kind not in KINDS_THAT_END_WORDS:
1814 p_die('Unexpected token after array literal',
1815 self.cur_token)
1816 done = True
1817
1818 elif (is_first and self.parse_opts.parse_at() and
1819 self.token_type == Id.Lit_Splice):
1820
1821 splice_tok = self.cur_token
1822 part2 = word_part.Splice(splice_tok,
1823 lexer.TokenSliceLeft(splice_tok, 1))
1824
1825 parts.append(part2)
1826
1827 # @words must be the last part of the word
1828 self._SetNext(lex_mode)
1829 self._GetToken()
1830 # EOF, whitespace, newline, Right_Subshell
1831 if self.token_kind not in KINDS_THAT_END_WORDS:
1832 p_die('Unexpected token after array splice', self.cur_token)
1833 done = True
1834
1835 elif (is_first and self.parse_opts.parse_at() and
1836 self.token_type == Id.Lit_AtLBracket): # @[split(x)]
1837 part2 = self._ReadExprSub(lex_mode_e.DQ)
1838 parts.append(part2)
1839
1840 # @[split(x)]
1841 self._SetNext(lex_mode)
1842 self._GetToken()
1843 # EOF, whitespace, newline, Right_Subshell
1844 if self.token_kind not in KINDS_THAT_END_WORDS:
1845 p_die('Unexpected token after Expr splice', self.cur_token)
1846 done = True
1847
1848 elif (is_first and self.parse_opts.parse_at() and
1849 self.token_type == Id.Lit_AtLBraceDot):
1850 p_die('TODO: @{.myproc builtin sub}', self.cur_token)
1851
1852 elif (is_first and self.parse_opts.parse_at_all() and
1853 self.token_type == Id.Lit_At):
1854 # Because $[x] ${x} and perhaps $/x/ are reserved, it makes sense for @
1855 # at the beginning of a word to be reserved.
1856
1857 # Although should we relax 'echo @' ? I'm tempted to have a shortcut for
1858 # @_argv and
1859 p_die('Literal @ starting a word must be quoted (parse_at_all)',
1860 self.cur_token)
1861
1862 else:
1863 # not a literal with lookahead; append it
1864 parts.append(part)
1865
1866 return done
1867
1868 def _ReadCompoundWord(self, lex_mode):
1869 # type: (lex_mode_t) -> CompoundWord
1870
1871 # This is the ONLY lexer mode that can return word.Redir
1872 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1873
1874 w = self._ReadCompoundOrRedir(lex_mode)
1875 assert w.tag() == word_e.Compound, w
1876 return cast(CompoundWord, w)
1877
1878 def _ReadCompoundWord3(self, lex_mode, eof_type, empty_ok):
1879 # type: (lex_mode_t, Id_t, bool) -> CompoundWord
1880
1881 # This is the ONLY lexer mode that can return word.Redir
1882 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1883
1884 w = self._ReadCompoundOrRedir3(lex_mode, eof_type, empty_ok)
1885 assert w.tag() == word_e.Compound, w
1886 return cast(CompoundWord, w)
1887
1888 def _ReadCompoundOrRedir(self, lex_mode):
1889 # type: (lex_mode_t) -> word_t
1890 """Returns either word.Compound or word.Redir"""
1891 return self._ReadCompoundOrRedir3(lex_mode, Id.Undefined_Tok, True)
1892
1893 def _ReadCompoundOrRedir3(self, lex_mode, eof_type, empty_ok):
1894 # type: (lex_mode_t, Id_t, bool) -> word_t
1895 """
1896 Precondition: Looking at the first token of the first word part
1897 Postcondition: Looking at the token after, e.g. space or operator
1898
1899 NOTE: eof_type is necessary because / is a literal, i.e. Lit_Slash, but it
1900 could be an operator delimiting a compound word. Can we change lexer modes
1901 and remove this special case?
1902
1903 Returns either word.Compound or word.Redir
1904 """
1905 w = CompoundWord([])
1906 num_parts = 0
1907 brace_count = 0
1908 done = False
1909 is_triple_quoted = None # type: Optional[BoolParamBox]
1910 saw_redir_left_tok = False
1911
1912 while not done:
1913 self._GetToken()
1914
1915 allow_done = empty_ok or num_parts != 0
1916 if allow_done and self.token_type == eof_type:
1917 done = True # e.g. for ${foo//pat/replace}
1918
1919 # Keywords like "for" are treated like literals
1920 elif self.token_kind in (Kind.Lit, Kind.History, Kind.KW,
1921 Kind.ControlFlow, Kind.BoolUnary,
1922 Kind.BoolBinary):
1923
1924 # Syntax error for { and }
1925 if self.token_type == Id.Lit_LBrace:
1926 brace_count += 1
1927 elif self.token_type == Id.Lit_RBrace:
1928 brace_count -= 1
1929 elif self.token_type == Id.Lit_Dollar:
1930 if self.parse_opts.no_parse_dollar():
1931 if num_parts == 0 and lex_mode == lex_mode_e.ShCommand:
1932 next_byte = self.lexer.ByteLookAhead()
1933 # TODO: switch lexer modes and parse $/d+/. But not ${a:-$/d+/}
1934 if next_byte == '/':
1935 #log('next_byte %r', next_byte)
1936 pass
1937
1938 p_die(
1939 'Literal $ should be quoted like \$ (no_parse_dollar)',
1940 self.cur_token)
1941 elif self.token_type in (Id.Lit_Number, Id.Lit_RedirVarName):
1942 saw_redir_left_tok = True
1943
1944 done = self._MaybeReadWordPart(num_parts == 0, lex_mode,
1945 w.parts)
1946
1947 elif self.token_kind == Kind.VSub:
1948 vsub_token = self.cur_token
1949
1950 part = SimpleVarSub(vsub_token) # type: word_part_t
1951 w.parts.append(part)
1952
1953 elif self.token_kind == Kind.ExtGlob:
1954 # If parse_at, we can take over @( to start @(seq 3)
1955 # Users can also use look at ,(*.py|*.sh)
1956 if (self.parse_opts.parse_at() and
1957 self.token_type == Id.ExtGlob_At and num_parts == 0):
1958 cs_part = self._ReadCommandSub(Id.Left_AtParen,
1959 d_quoted=False)
1960 # RARE mutation of tok.id!
1961 cs_part.left_token.id = Id.Left_AtParen
1962 part = cs_part # for type safety
1963
1964 # Same check as _MaybeReadWordPart. @(seq 3)x is illegal, just like
1965 # a=(one two)x and @arrayfunc(3)x.
1966 self._GetToken()
1967 if self.token_kind not in KINDS_THAT_END_WORDS:
1968 p_die('Unexpected token after @()', self.cur_token)
1969 done = True
1970
1971 else:
1972 if HAVE_FNM_EXTMATCH == 0:
1973 p_die(
1974 "Extended glob won't work without FNM_EXTMATCH support in libc",
1975 self.cur_token)
1976 part = self._ReadExtGlob()
1977 w.parts.append(part)
1978
1979 elif self.token_kind == Kind.BashRegex:
1980 if self.token_type == Id.BashRegex_LParen: # Opening (
1981 part = self._ReadBashRegexGroup()
1982 w.parts.append(part)
1983 else:
1984 assert self.token_type == Id.BashRegex_AllowedInParens
1985 p_die('Invalid token in bash regex', self.cur_token)
1986
1987 elif self.token_kind == Kind.Left:
1988 try_triple_quote = (self.parse_opts.parse_triple_quote() and
1989 lex_mode == lex_mode_e.ShCommand and
1990 num_parts == 0)
1991
1992 # Save allocation
1993 if try_triple_quote:
1994 is_triple_quoted = BoolParamBox(False)
1995
1996 part = self._ReadUnquotedLeftParts(is_triple_quoted)
1997 w.parts.append(part)
1998
1999 # NOT done yet, will advance below
2000 elif self.token_kind == Kind.Right:
2001 # Still part of the word; will be done on the next iter.
2002 if self.token_type == Id.Right_DoubleQuote:
2003 pass
2004 # Never happens, no PushHint for this case.
2005 #elif self.token_type == Id.Right_DollarParen:
2006 # pass
2007 elif self.token_type == Id.Right_Subshell:
2008 # LEXER HACK for (case x in x) ;; esac )
2009 # Rewind before it's used
2010 assert self.next_lex_mode == lex_mode_e.Undefined
2011 if self.lexer.MaybeUnreadOne():
2012 self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
2013 self._SetNext(lex_mode)
2014 done = True
2015 else:
2016 done = True
2017
2018 elif self.token_kind == Kind.Redir:
2019 # Check if the previous token was a possible left_tok to a
2020 # redirect operator, attach it to the word.Redir. And return
2021 # it instead of the CompoundWord.
2022
2023 # &> and &>> don't have a leading descriptor (2 is implied)
2024 if (saw_redir_left_tok and num_parts == 1 and self.token_type
2025 not in (Id.Redir_AndGreat, Id.Redir_AndDGreat)):
2026
2027 self._SetNext(lex_mode)
2028 left_tok = cast(Token, w.parts.pop())
2029 r = word.Redir(left_tok, self.cur_token)
2030 return r # EARLY RETURN
2031
2032 done = True
2033
2034 elif self.token_kind == Kind.Ignored:
2035 done = True
2036
2037 else:
2038 # LEXER HACK for unbalanced case clause. 'case foo in esac' is valid,
2039 # so to test for ESAC, we can read ) before getting a chance to
2040 # PushHint(Id.Op_RParen, Id.Right_CasePat). So here we unread one
2041 # token and do it again.
2042
2043 # We get Id.Op_RParen at top level: case x in x) ;; esac
2044 # We get Id.Eof_RParen inside ComSub: $(case x in x) ;; esac )
2045 if self.token_type in (Id.Op_RParen, Id.Eof_RParen):
2046 # Rewind before it's used
2047 assert self.next_lex_mode == lex_mode_e.Undefined
2048 if self.lexer.MaybeUnreadOne():
2049 if self.token_type == Id.Eof_RParen:
2050 # Redo translation
2051 self.lexer.PushHint(Id.Op_RParen, Id.Eof_RParen)
2052 self._SetNext(lex_mode)
2053
2054 done = True # anything we don't recognize means we're done
2055
2056 if not done:
2057 self._SetNext(lex_mode)
2058 num_parts += 1
2059
2060 if (self.parse_opts.parse_brace() and num_parts > 1 and
2061 brace_count != 0):
2062 # accept { and }, but not foo{
2063 p_die(
2064 'Word has unbalanced { }. Maybe add a space or quote it like \{',
2065 loc.Word(w))
2066
2067 if is_triple_quoted and is_triple_quoted.b and num_parts > 1:
2068 p_die('Unexpected parts after triple quoted string',
2069 loc.WordPart(w.parts[-1]))
2070
2071 if 0:
2072 from _devbuild.gen.syntax_asdl import word_part_str
2073 word_key = ' '.join(word_part_str(p.tag()) for p in w.parts)
2074 WORD_HIST[word_key] += 1
2075
2076 # YSH word restriction
2077 # (r'' u'' b'' are stripped on shopt -s parse_ysh_string)
2078 if self.parse_opts.no_parse_word_join() and not _IsValidYshWord(w):
2079 p_die("Invalid quoted word part in YSH (OILS-ERR-17)",
2080 loc.WordPart(part))
2081
2082 return w
2083
2084 def _ReadArithWord(self):
2085 # type: () -> Optional[word_t]
2086 """ Helper for ReadArithWord() """
2087 self._GetToken()
2088
2089 if self.token_kind == Kind.Unknown:
2090 # e.g. happened during dynamic parsing of unset 'a[$foo]' in gherkin
2091 p_die(
2092 'Unexpected token while parsing arithmetic: %r' %
2093 lexer.TokenVal(self.cur_token), self.cur_token)
2094
2095 elif self.token_kind == Kind.Eof:
2096 return self.cur_token
2097
2098 elif self.token_kind == Kind.Ignored:
2099 # Space should be ignored.
2100 self._SetNext(lex_mode_e.Arith)
2101 return None
2102
2103 elif self.token_kind in (Kind.Arith, Kind.Right):
2104 # Id.Right_DollarDParen IS just a normal token, handled by ArithParser
2105 self._SetNext(lex_mode_e.Arith)
2106 return self.cur_token
2107
2108 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub):
2109 return self._ReadCompoundWord(lex_mode_e.Arith)
2110
2111 else:
2112 raise AssertionError(self.cur_token)
2113
2114 def _ReadWord(self, word_mode):
2115 # type: (lex_mode_t) -> Optional[word_t]
2116 """Helper function for ReadWord()."""
2117
2118 # Change the pseudo lexer mode to a real lexer mode
2119 if word_mode == lex_mode_e.ShCommandFakeBrack:
2120 lex_mode = lex_mode_e.ShCommand
2121 else:
2122 lex_mode = word_mode
2123
2124 self._GetToken()
2125
2126 if self.token_kind == Kind.Eof:
2127 # No advance
2128 return self.cur_token
2129
2130 elif self.token_kind == Kind.Redir:
2131 self._SetNext(lex_mode)
2132 # This is >out -- 3>out is handled below
2133 return word.Redir(None, self.cur_token)
2134
2135 # Allow Arith for ) at end of for loop?
2136 elif self.token_kind in (Kind.Op, Kind.Arith):
2137 self._SetNext(lex_mode)
2138
2139 # Newlines are complicated. See 3x2 matrix in the comment about
2140 # self.multiline and self.newline_state above.
2141 if self.token_type == Id.Op_Newline:
2142 if self.multiline:
2143 if self.newline_state > 1:
2144 # This points at a blank line, but at least it gives the line number
2145 p_die('Invalid blank line in multiline mode',
2146 self.cur_token)
2147 return None
2148
2149 if self.returned_newline: # skip
2150 return None
2151
2152 return self.cur_token
2153
2154 elif self.token_kind == Kind.Right:
2155 if self.token_type not in (Id.Right_Subshell, Id.Right_ShFunction,
2156 Id.Right_CasePat, Id.Right_Initializer):
2157 raise AssertionError(self.cur_token)
2158
2159 self._SetNext(lex_mode)
2160 return self.cur_token
2161
2162 elif self.token_kind in (Kind.Ignored, Kind.WS):
2163 self._SetNext(lex_mode)
2164 return None
2165
2166 else:
2167 assert self.token_kind in (Kind.VSub, Kind.Lit, Kind.History,
2168 Kind.Left, Kind.KW, Kind.ControlFlow,
2169 Kind.BoolUnary, Kind.BoolBinary,
2170 Kind.ExtGlob,
2171 Kind.BashRegex), 'Unhandled token kind'
2172
2173 if (word_mode == lex_mode_e.ShCommandFakeBrack and
2174 self.parse_opts.parse_bracket() and
2175 self.token_type == Id.Lit_LBracket):
2176 # Change [ from Kind.Lit -> Kind.Op
2177 # So CommandParser can treat
2178 # assert [42 === x]
2179 # like
2180 # json write (x)
2181 bracket_word = self.cur_token
2182 bracket_word.id = Id.Op_LBracket
2183
2184 self._SetNext(lex_mode)
2185 return bracket_word
2186
2187 # We're beginning a word. If we see Id.Lit_Pound, change to
2188 # lex_mode_e.Comment and read until end of line.
2189 if self.token_type == Id.Lit_Pound:
2190 self._SetNext(lex_mode_e.Comment)
2191 self._GetToken()
2192
2193 # NOTE: The # could be the last character in the file. It can't be
2194 # Eof_{RParen,Backtick} because #) and #` are comments.
2195 assert self.token_type in (Id.Ignored_Comment, Id.Eof_Real), \
2196 self.cur_token
2197
2198 # The next iteration will go into Kind.Ignored and set lex state to
2199 # lex_mode_e.ShCommand/etc.
2200 return None # tell ReadWord() to try again after comment
2201
2202 elif self.token_type == Id.Lit_TPound: ### doc comment
2203 self._SetNext(lex_mode_e.Comment)
2204 self._GetToken()
2205
2206 if self.token_type == Id.Ignored_Comment and self.emit_doc_token:
2207 return self.cur_token
2208
2209 return None # tell ReadWord() to try again after comment
2210
2211 else:
2212 # r'' u'' b'' at the beginning of a word
2213 if (self.token_type == Id.Lit_Chars and
2214 self.lexer.LookAheadOne(
2215 lex_mode_e.ShCommand) == Id.Left_SingleQuote):
2216
2217 # When shopt -s parse_ysh_string:
2218 # echo r'hi' is like echo 'hi'
2219 #
2220 # echo u'\u{3bc}' b'\yff' works
2221
2222 tok = self.cur_token
2223 if self.parse_opts.parse_ysh_string():
2224 if lexer.TokenEquals(tok, 'r'):
2225 left_id = Id.Left_RSingleQuote
2226 elif lexer.TokenEquals(tok, 'u'):
2227 left_id = Id.Left_USingleQuote
2228 elif lexer.TokenEquals(tok, 'b'):
2229 left_id = Id.Left_BSingleQuote
2230 else:
2231 left_id = Id.Undefined_Tok
2232
2233 if left_id != Id.Undefined_Tok:
2234 # skip the r, and then 'foo' will be read as normal
2235 self._SetNext(lex_mode_e.ShCommand)
2236
2237 self._GetToken()
2238 assert self.token_type == Id.Left_SingleQuote, self.token_type
2239
2240 # Read the word in a different lexer mode
2241 return self._ReadYshSingleQuoted(left_id)
2242
2243 return self._ReadCompoundOrRedir(lex_mode)
2244
2245 def ParseVarRef(self):
2246 # type: () -> BracedVarSub
2247 """DYNAMIC parsing of what's inside ${!ref}
2248
2249 # Same as VarOf production
2250 VarRefExpr = VarOf EOF
2251 """
2252 self._SetNext(lex_mode_e.VSub_1)
2253
2254 self._GetToken()
2255 if self.token_kind != Kind.VSub:
2256 p_die('Expected var name', self.cur_token)
2257
2258 part = self._ParseVarOf()
2259 # NOTE: no ${ } means no part.left and part.right
2260 part.left = part.name_tok # cheat to make test pass
2261 part.right = part.name_tok
2262
2263 self._GetToken()
2264 if self.token_type != Id.Eof_Real:
2265 p_die('Expected end of var ref expression', self.cur_token)
2266 return part
2267
2268 def LookPastSpace(self):
2269 # type: () -> Id_t
2270 """Look ahead to the next token.
2271
2272 For the CommandParser to recognize
2273 array= (1 2 3)
2274 YSH for ( versus bash for ((
2275 YSH if ( versus if test
2276 YSH while ( versus while test
2277 YSH bare assignment 'grep =' versus 'grep foo'
2278 """
2279 assert self.token_type != Id.Undefined_Tok
2280 if self.cur_token.id == Id.WS_Space:
2281 id_ = self.lexer.LookPastSpace(lex_mode_e.ShCommand)
2282 else:
2283 id_ = self.cur_token.id
2284 return id_
2285
2286 def LookAheadDParens(self, shift_back=0):
2287 # type: (int) -> bool
2288 """Special lookahead for (( )), to make sure it's an arithmetic
2289 expression (i.e. that the closing parens are a single token, not
2290 separated by anything).
2291 """
2292 assert self.token_type in (Id.Op_DLeftParen, Id.Left_DollarDParen)
2293
2294 return self.lexer.LookAheadDParens(shift_back)
2295
2296 def LookAheadFuncParens(self):
2297 # type: () -> bool
2298 """Special lookahead for f( ) { echo hi; } to check for ( )"""
2299 assert self.token_type != Id.Undefined_Tok
2300
2301 # We have to handle 2 cases because we buffer a token
2302 if self.cur_token.id == Id.Op_LParen: # saw funcname(
2303 return self.lexer.LookAheadFuncParens(1) # go back one char
2304
2305 elif self.cur_token.id == Id.WS_Space: # saw funcname WHITESPACE
2306 return self.lexer.LookAheadFuncParens(0)
2307
2308 else:
2309 return False
2310
2311 def ReadWord(self, word_mode):
2312 # type: (lex_mode_t) -> word_t
2313 """Read the next word, using the given lexer mode.
2314
2315 This is a stateful wrapper for the stateless _ReadWord function.
2316 """
2317 assert word_mode in (lex_mode_e.ShCommand,
2318 lex_mode_e.ShCommandFakeBrack,
2319 lex_mode_e.DBracket, lex_mode_e.BashRegex)
2320
2321 if self.buffered_word: # For integration with pgen2
2322 w = self.buffered_word
2323 self.buffered_word = None
2324 else:
2325 while True:
2326 w = self._ReadWord(word_mode)
2327 if w is not None:
2328 break
2329
2330 self.returned_newline = (word_.CommandId(w) == Id.Op_Newline)
2331 return w
2332
2333 def ReadArithWord(self):
2334 # type: () -> word_t
2335 while True:
2336 w = self._ReadArithWord()
2337 if w is not None:
2338 break
2339 return w
2340
2341 def ReadHereDocBody(self, parts):
2342 # type: (List[word_part_t]) -> None
2343 """
2344 A here doc is like a double quoted context, except " and \" aren't special.
2345 """
2346 self._ReadLikeDQ(None, False, parts, is_here_doc=True)
2347 # Returns nothing
2348
2349 def ReadForPlugin(self):
2350 # type: () -> CompoundWord
2351 """For $PS1, $PS4, etc.
2352
2353 This is just like reading a here doc line. "\n" is allowed, as
2354 well as the typical substitutions ${x} $(echo hi) $((1 + 2)).
2355 """
2356 w = CompoundWord([])
2357 self._ReadLikeDQ(None, False, w.parts)
2358 return w
2359
2360 def EmitDocToken(self, b):
2361 # type: (bool) -> None
2362 self.emit_doc_token = b
2363
2364 def Multiline(self, b):
2365 # type: (bool) -> None
2366 self.multiline = b
2367
2368
2369if 0:
2370 import collections
2371 WORD_HIST = collections.Counter()
2372
2373# vim: sw=4