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 tok = self.cur_token
1093
1094 if self.token_kind == Kind.Lit:
1095 if self.token_type == Id.Lit_EscapedChar:
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_BackslashDoubleQuote:
1101 if left_token:
1102 ch = lexer.TokenSliceLeft(tok, 1)
1103 part = word_part.EscapedLiteral(tok, ch)
1104 else:
1105 # in here docs \" should not be escaped, staying as literal characters
1106 tok.id = Id.Lit_Chars
1107 part = tok
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 tok)
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 \$", tok)
1123
1124 part = tok
1125
1126 out_parts.append(part)
1127
1128 elif self.token_kind == Kind.Left:
1129 if self.token_type == Id.Left_Backtick and is_ysh_expr:
1130 p_die("Backtick should be $(cmd) or \\` (OILS-ERR-18)",
1131 tok)
1132
1133 part = self._ReadDoubleQuotedLeftParts()
1134 out_parts.append(part)
1135
1136 elif self.token_kind == Kind.VSub:
1137 part = SimpleVarSub(tok)
1138 out_parts.append(part)
1139 # NOTE: parsing "$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(tok)
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(tok)
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 if end_id == Id.Arith_RParen:
1576 self.lexer.PushHint(Id.Op_RParen, Id.Right_DollarDParen)
1577
1578 # NOTE: To disambiguate $(( as arith sub vs. command sub and subshell, we
1579 # could save the lexer/reader state here, and retry if the arithmetic parse
1580 # fails. But we can almost always catch this at parse time. There could
1581 # be some exceptions like:
1582 # $((echo * foo)) # looks like multiplication
1583 # $((echo / foo)) # looks like division
1584
1585 # $(( )) is valid
1586 anode = arith_expr.EmptyZero # type: arith_expr_t
1587
1588 self._NextNonSpace()
1589 if self.token_type != Id.Arith_RParen:
1590 anode = self._ReadArithExpr(end_id)
1591
1592 self._SetNext(lex_mode_e.ShCommand)
1593
1594 if end_id == Id.Arith_RParen:
1595 # Ensure we get closing ) if we are looking for double ))
1596 # (In backwards compat mode, ] can also be the closing bracket, and
1597 # it would already be the current token, no need to skip further
1598 self._GetToken()
1599 if self.token_type != Id.Right_DollarDParen:
1600 p_die('Expected second ) to end arith sub', self.cur_token)
1601
1602 right_tok = self.cur_token
1603 return word_part.ArithSub(left_tok, anode, right_tok)
1604
1605 def ReadDParen(self):
1606 # type: () -> Tuple[arith_expr_t, Token]
1607 """Read ((1+ 2)) -- command context.
1608
1609 We're using the word parser because it's very similar to _ReadArithExpr
1610 above.
1611
1612 This also returns the terminating Id.Op_DRightParen token for location
1613 info.
1614 """
1615 # (( )) is valid
1616 anode = arith_expr.EmptyZero # type: arith_expr_t
1617
1618 self.lexer.PushHint(Id.Op_RParen, Id.Op_DRightParen)
1619
1620 self._NextNonSpace()
1621 if self.token_type != Id.Arith_RParen:
1622 anode = self._ReadArithExpr(Id.Arith_RParen)
1623
1624 self._SetNext(lex_mode_e.ShCommand)
1625
1626 # Ensure we get the second )
1627 self._GetToken()
1628 right = self.cur_token
1629 if right.id != Id.Op_DRightParen:
1630 p_die('Expected second ) to end arith statement', right)
1631
1632 self._SetNext(lex_mode_e.ShCommand)
1633
1634 return anode, right
1635
1636 def _NextNonSpace(self):
1637 # type: () -> None
1638 """Advance in lex_mode_e.Arith until non-space token.
1639
1640 Same logic as _ReadWord, but used in
1641 $(( ))
1642 (( ))
1643 for (( ))
1644
1645 You can read self.token_type after this, without calling _GetToken.
1646 """
1647 while True:
1648 self._SetNext(lex_mode_e.Arith)
1649 self._GetToken()
1650 if self.token_kind not in (Kind.Ignored, Kind.WS):
1651 break
1652
1653 def ReadForExpression(self):
1654 # type: () -> command.ForExpr
1655 """Read ((i=0; i<5; ++i)) -- part of command context."""
1656 self._NextNonSpace() # skip over ((
1657 cur_id = self.token_type # for end of arith expressions
1658
1659 if cur_id == Id.Arith_Semi: # for (( ; i < 10; i++ ))
1660 init_node = arith_expr.EmptyZero # type: arith_expr_t
1661 else:
1662 init_node = self.a_parser.Parse()
1663 cur_id = self.a_parser.CurrentId()
1664 self._NextNonSpace()
1665
1666 # It's odd to keep track of both cur_id and self.token_type in this
1667 # function, but it works, and is tested in 'test/parse_error.sh
1668 # arith-integration'
1669 if cur_id != Id.Arith_Semi: # for (( x=0 b; ... ))
1670 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1671
1672 self._GetToken()
1673 cur_id = self.token_type
1674
1675 if cur_id == Id.Arith_Semi: # for (( ; ; i++ ))
1676 # empty condition is TRUE
1677 cond_node = arith_expr.EmptyOne # type: arith_expr_t
1678 else:
1679 cond_node = self.a_parser.Parse()
1680 cur_id = self.a_parser.CurrentId()
1681
1682 if cur_id != Id.Arith_Semi: # for (( x=0; x<5 b ))
1683 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1684
1685 self._NextNonSpace()
1686 if self.token_type == Id.Arith_RParen: # for (( ; ; ))
1687 update_node = arith_expr.EmptyZero # type: arith_expr_t
1688 else:
1689 update_node = self._ReadArithExpr(Id.Arith_RParen)
1690
1691 self._NextNonSpace()
1692 if self.token_type != Id.Arith_RParen:
1693 p_die('Expected ) to end for loop expression', self.cur_token)
1694 self._SetNext(lex_mode_e.ShCommand)
1695
1696 # redirects is None, will be assigned in CommandEvaluator
1697 node = command.ForExpr.CreateNull()
1698 node.init = init_node
1699 node.cond = cond_node
1700 node.update = update_node
1701 return node
1702
1703 def _ReadArrayLiteral(self):
1704 # type: () -> word_part_t
1705 """a=(1 2 3)
1706
1707 TODO: See osh/cmd_parse.py:164 for Id.Lit_ArrayLhsOpen, for a[x++]=1
1708
1709 We want:
1710
1711 A=(['x']=1 ["x"]=2 [$x$y]=3)
1712
1713 Maybe allow this as a literal string? Because I think I've seen it before?
1714 Or maybe force people to patch to learn the rule.
1715
1716 A=([x]=4)
1717
1718 Starts with Lit_Other '[', and then it has Lit_ArrayLhsClose
1719 Maybe enforce that ALL have keys or NONE of have keys.
1720 """
1721 self._SetNext(lex_mode_e.ShCommand) # advance past (
1722 self._GetToken()
1723 if self.cur_token.id != Id.Op_LParen:
1724 p_die('Expected ( after =', self.cur_token)
1725 left_token = self.cur_token
1726 right_token = None # type: Token
1727
1728 # MUST use a new word parser (with same lexer).
1729 w_parser = self.parse_ctx.MakeWordParser(self.lexer, self.line_reader)
1730 words = [] # type: List[CompoundWord]
1731 done = False
1732 while not done:
1733 w = w_parser.ReadWord(lex_mode_e.ShCommand)
1734 with tagswitch(w) as case:
1735 if case(word_e.Operator):
1736 tok = cast(Token, w)
1737 if tok.id == Id.Right_Initializer:
1738 right_token = tok
1739 done = True # can't use break here
1740 # Unlike command parsing, array parsing allows embedded \n.
1741 elif tok.id == Id.Op_Newline:
1742 continue
1743 else:
1744 p_die('Unexpected token in array literal', loc.Word(w))
1745
1746 elif case(word_e.Compound):
1747 words.append(cast(CompoundWord, w))
1748
1749 else:
1750 raise AssertionError()
1751
1752 initializer_words = [] # type: List[InitializerWord_t]
1753 for w in words:
1754 pair = word_.DetectAssocPair(w)
1755 if pair is not None:
1756 word_.TildeDetectAssign(pair.value) # pair.value is modified
1757 initializer_words.append(pair)
1758 else:
1759 w2 = braces.BraceDetect(w) # type: word_t
1760 if w2 is None:
1761 w2 = w
1762 w3 = word_.TildeDetect(w2) # type: word_t
1763 if w3 is None:
1764 w3 = w2
1765 initializer_words.append(InitializerWord.ArrayWord(w3))
1766
1767 # invariant List?
1768 return word_part.InitializerLiteral(left_token, initializer_words,
1769 right_token)
1770
1771 def ParseProcCallArgs(self, start_symbol):
1772 # type: (int) -> ArgList
1773 """ json write (x) """
1774 self.lexer.MaybeUnreadOne()
1775
1776 arg_list = ArgList.CreateNull(alloc_lists=True)
1777 arg_list.left = self.cur_token
1778 self.parse_ctx.ParseProcCallArgs(self.lexer, arg_list, start_symbol)
1779 return arg_list
1780
1781 def _MaybeReadWordPart(self, is_first, lex_mode, parts):
1782 # type: (bool, lex_mode_t, List[word_part_t]) -> bool
1783 """Helper for _ReadCompoundWord3."""
1784 done = False
1785
1786 if self.token_type == Id.Lit_EscapedChar:
1787 tok = self.cur_token
1788 assert tok.length == 2
1789 ch = lexer.TokenSliceLeft(tok, 1)
1790 if self.parse_opts.no_parse_backslash():
1791 if not pyutil.IsValidCharEscape(ch):
1792 p_die('Invalid char escape in unquoted word (OILS-ERR-13)',
1793 self.cur_token)
1794
1795 part = word_part.EscapedLiteral(self.cur_token,
1796 ch) # type: word_part_t
1797 else:
1798 part = self.cur_token
1799
1800 if is_first and self.token_type == Id.Lit_VarLike: # foo=
1801 parts.append(part)
1802 # Unfortunately it's awkward to pull the check for a=(1 2) up to
1803 # _ReadWord.
1804 next_id = self.lexer.LookPastSpace(lex_mode)
1805 if next_id == Id.Op_LParen:
1806 self.lexer.PushHint(Id.Op_RParen, Id.Right_Initializer)
1807 part2 = self._ReadArrayLiteral()
1808 parts.append(part2)
1809
1810 # Array literal must be the last part of the word.
1811 self._SetNext(lex_mode)
1812 self._GetToken()
1813 # EOF, whitespace, newline, Right_Subshell
1814 if self.token_kind not in KINDS_THAT_END_WORDS:
1815 p_die('Unexpected token after array literal',
1816 self.cur_token)
1817 done = True
1818
1819 elif (is_first and self.parse_opts.parse_at() and
1820 self.token_type == Id.Lit_Splice):
1821
1822 splice_tok = self.cur_token
1823 part2 = word_part.Splice(splice_tok,
1824 lexer.TokenSliceLeft(splice_tok, 1))
1825
1826 parts.append(part2)
1827
1828 # @words must be the last part of the word
1829 self._SetNext(lex_mode)
1830 self._GetToken()
1831 # EOF, whitespace, newline, Right_Subshell
1832 if self.token_kind not in KINDS_THAT_END_WORDS:
1833 p_die('Unexpected token after array splice', self.cur_token)
1834 done = True
1835
1836 elif (is_first and self.parse_opts.parse_at() and
1837 self.token_type == Id.Lit_AtLBracket): # @[split(x)]
1838 part2 = self._ReadExprSub(lex_mode_e.DQ)
1839 parts.append(part2)
1840
1841 # @[split(x)]
1842 self._SetNext(lex_mode)
1843 self._GetToken()
1844 # EOF, whitespace, newline, Right_Subshell
1845 if self.token_kind not in KINDS_THAT_END_WORDS:
1846 p_die('Unexpected token after Expr splice', self.cur_token)
1847 done = True
1848
1849 elif (is_first and self.parse_opts.parse_at() and
1850 self.token_type == Id.Lit_AtLBraceDot):
1851 p_die('TODO: @{.myproc builtin sub}', self.cur_token)
1852
1853 elif (is_first and self.parse_opts.parse_at_all() and
1854 self.token_type == Id.Lit_At):
1855 # Because $[x] ${x} and perhaps $/x/ are reserved, it makes sense for @
1856 # at the beginning of a word to be reserved.
1857
1858 # Although should we relax 'echo @' ? I'm tempted to have a shortcut for
1859 # @_argv and
1860 p_die('Literal @ starting a word must be quoted (parse_at_all)',
1861 self.cur_token)
1862
1863 else:
1864 # not a literal with lookahead; append it
1865 parts.append(part)
1866
1867 return done
1868
1869 def _ReadCompoundWord(self, lex_mode):
1870 # type: (lex_mode_t) -> CompoundWord
1871
1872 # This is the ONLY lexer mode that can return word.Redir
1873 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1874
1875 w = self._ReadCompoundOrRedir(lex_mode)
1876 assert w.tag() == word_e.Compound, w
1877 return cast(CompoundWord, w)
1878
1879 def _ReadCompoundWord3(self, lex_mode, eof_type, empty_ok):
1880 # type: (lex_mode_t, Id_t, bool) -> CompoundWord
1881
1882 # This is the ONLY lexer mode that can return word.Redir
1883 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1884
1885 w = self._ReadCompoundOrRedir3(lex_mode, eof_type, empty_ok)
1886 assert w.tag() == word_e.Compound, w
1887 return cast(CompoundWord, w)
1888
1889 def _ReadCompoundOrRedir(self, lex_mode):
1890 # type: (lex_mode_t) -> word_t
1891 """Returns either word.Compound or word.Redir"""
1892 return self._ReadCompoundOrRedir3(lex_mode, Id.Undefined_Tok, True)
1893
1894 def _ReadCompoundOrRedir3(self, lex_mode, eof_type, empty_ok):
1895 # type: (lex_mode_t, Id_t, bool) -> word_t
1896 """
1897 Precondition: Looking at the first token of the first word part
1898 Postcondition: Looking at the token after, e.g. space or operator
1899
1900 NOTE: eof_type is necessary because / is a literal, i.e. Lit_Slash, but it
1901 could be an operator delimiting a compound word. Can we change lexer modes
1902 and remove this special case?
1903
1904 Returns either word.Compound or word.Redir
1905 """
1906 w = CompoundWord([])
1907 num_parts = 0
1908 brace_count = 0
1909 done = False
1910 is_triple_quoted = None # type: Optional[BoolParamBox]
1911 saw_redir_left_tok = False
1912
1913 while not done:
1914 self._GetToken()
1915
1916 allow_done = empty_ok or num_parts != 0
1917 if allow_done and self.token_type == eof_type:
1918 done = True # e.g. for ${foo//pat/replace}
1919
1920 # Keywords like "for" are treated like literals
1921 elif self.token_kind in (Kind.Lit, Kind.History, Kind.KW,
1922 Kind.ControlFlow, Kind.BoolUnary,
1923 Kind.BoolBinary):
1924
1925 # Syntax error for { and }
1926 if self.token_type == Id.Lit_LBrace:
1927 brace_count += 1
1928 elif self.token_type == Id.Lit_RBrace:
1929 brace_count -= 1
1930 elif self.token_type == Id.Lit_Dollar:
1931 if self.parse_opts.no_parse_dollar():
1932 if num_parts == 0 and lex_mode == lex_mode_e.ShCommand:
1933 next_byte = self.lexer.ByteLookAhead()
1934 # TODO: switch lexer modes and parse $/d+/. But not ${a:-$/d+/}
1935 if next_byte == '/':
1936 #log('next_byte %r', next_byte)
1937 pass
1938
1939 p_die(
1940 'Literal $ should be quoted like \$ (no_parse_dollar)',
1941 self.cur_token)
1942 elif self.token_type in (Id.Lit_Number, Id.Lit_RedirVarName):
1943 saw_redir_left_tok = True
1944
1945 done = self._MaybeReadWordPart(num_parts == 0, lex_mode,
1946 w.parts)
1947
1948 elif self.token_kind == Kind.VSub:
1949 vsub_token = self.cur_token
1950
1951 part = SimpleVarSub(vsub_token) # type: word_part_t
1952 w.parts.append(part)
1953
1954 elif self.token_kind == Kind.ExtGlob:
1955 # If parse_at, we can take over @( to start @(seq 3)
1956 # Users can also use look at ,(*.py|*.sh)
1957 if (self.parse_opts.parse_at() and
1958 self.token_type == Id.ExtGlob_At and num_parts == 0):
1959 cs_part = self._ReadCommandSub(Id.Left_AtParen,
1960 d_quoted=False)
1961 # RARE mutation of tok.id!
1962 cs_part.left_token.id = Id.Left_AtParen
1963 part = cs_part # for type safety
1964
1965 # Same check as _MaybeReadWordPart. @(seq 3)x is illegal, just like
1966 # a=(one two)x and @arrayfunc(3)x.
1967 self._GetToken()
1968 if self.token_kind not in KINDS_THAT_END_WORDS:
1969 p_die('Unexpected token after @()', self.cur_token)
1970 done = True
1971
1972 else:
1973 if HAVE_FNM_EXTMATCH == 0:
1974 p_die(
1975 "Extended glob won't work without FNM_EXTMATCH support in libc",
1976 self.cur_token)
1977 part = self._ReadExtGlob()
1978 w.parts.append(part)
1979
1980 elif self.token_kind == Kind.BashRegex:
1981 if self.token_type == Id.BashRegex_LParen: # Opening (
1982 part = self._ReadBashRegexGroup()
1983 w.parts.append(part)
1984 else:
1985 assert self.token_type == Id.BashRegex_AllowedInParens
1986 p_die('Invalid token in bash regex', self.cur_token)
1987
1988 elif self.token_kind == Kind.Left:
1989 try_triple_quote = (self.parse_opts.parse_triple_quote() and
1990 lex_mode == lex_mode_e.ShCommand and
1991 num_parts == 0)
1992
1993 # Save allocation
1994 if try_triple_quote:
1995 is_triple_quoted = BoolParamBox(False)
1996
1997 part = self._ReadUnquotedLeftParts(is_triple_quoted)
1998 w.parts.append(part)
1999
2000 # NOT done yet, will advance below
2001 elif self.token_kind == Kind.Right:
2002 # Still part of the word; will be done on the next iter.
2003 if self.token_type == Id.Right_DoubleQuote:
2004 pass
2005 # Never happens, no PushHint for this case.
2006 #elif self.token_type == Id.Right_DollarParen:
2007 # pass
2008 elif self.token_type == Id.Right_Subshell:
2009 # LEXER HACK for (case x in x) ;; esac )
2010 # Rewind before it's used
2011 assert self.next_lex_mode == lex_mode_e.Undefined
2012 if self.lexer.MaybeUnreadOne():
2013 self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
2014 self._SetNext(lex_mode)
2015 done = True
2016 else:
2017 done = True
2018
2019 elif self.token_kind == Kind.Redir:
2020 # Check if the previous token was a possible left_tok to a
2021 # redirect operator, attach it to the word.Redir. And return
2022 # it instead of the CompoundWord.
2023
2024 # &> and &>> don't have a leading descriptor (2 is implied)
2025 if (saw_redir_left_tok and num_parts == 1 and self.token_type
2026 not in (Id.Redir_AndGreat, Id.Redir_AndDGreat)):
2027
2028 self._SetNext(lex_mode)
2029 left_tok = cast(Token, w.parts.pop())
2030 r = word.Redir(left_tok, self.cur_token)
2031 return r # EARLY RETURN
2032
2033 done = True
2034
2035 elif self.token_kind == Kind.Ignored:
2036 done = True
2037
2038 else:
2039 # LEXER HACK for unbalanced case clause. 'case foo in esac' is valid,
2040 # so to test for ESAC, we can read ) before getting a chance to
2041 # PushHint(Id.Op_RParen, Id.Right_CasePat). So here we unread one
2042 # token and do it again.
2043
2044 # We get Id.Op_RParen at top level: case x in x) ;; esac
2045 # We get Id.Eof_RParen inside ComSub: $(case x in x) ;; esac )
2046 if self.token_type in (Id.Op_RParen, Id.Eof_RParen):
2047 # Rewind before it's used
2048 assert self.next_lex_mode == lex_mode_e.Undefined
2049 if self.lexer.MaybeUnreadOne():
2050 if self.token_type == Id.Eof_RParen:
2051 # Redo translation
2052 self.lexer.PushHint(Id.Op_RParen, Id.Eof_RParen)
2053 self._SetNext(lex_mode)
2054
2055 done = True # anything we don't recognize means we're done
2056
2057 if not done:
2058 self._SetNext(lex_mode)
2059 num_parts += 1
2060
2061 if (self.parse_opts.parse_brace() and num_parts > 1 and
2062 brace_count != 0):
2063 # accept { and }, but not foo{
2064 p_die(
2065 'Word has unbalanced { }. Maybe add a space or quote it like \{',
2066 loc.Word(w))
2067
2068 if is_triple_quoted and is_triple_quoted.b and num_parts > 1:
2069 p_die('Unexpected parts after triple quoted string',
2070 loc.WordPart(w.parts[-1]))
2071
2072 if 0:
2073 from _devbuild.gen.syntax_asdl import word_part_str
2074 word_key = ' '.join(word_part_str(p.tag()) for p in w.parts)
2075 WORD_HIST[word_key] += 1
2076
2077 # YSH word restriction
2078 # (r'' u'' b'' are stripped on shopt -s parse_ysh_string)
2079 if self.parse_opts.no_parse_word_join() and not _IsValidYshWord(w):
2080 p_die("Invalid quoted word part in YSH (OILS-ERR-17)",
2081 loc.WordPart(part))
2082
2083 return w
2084
2085 def _ReadArithWord(self):
2086 # type: () -> Optional[word_t]
2087 """ Helper for ReadArithWord() """
2088 self._GetToken()
2089
2090 if self.token_kind == Kind.Unknown:
2091 # e.g. happened during dynamic parsing of unset 'a[$foo]' in gherkin
2092 p_die(
2093 'Unexpected token while parsing arithmetic: %r' %
2094 lexer.TokenVal(self.cur_token), self.cur_token)
2095
2096 elif self.token_kind == Kind.Eof:
2097 return self.cur_token
2098
2099 elif self.token_kind == Kind.Ignored:
2100 # Space should be ignored.
2101 self._SetNext(lex_mode_e.Arith)
2102 return None
2103
2104 elif self.token_kind in (Kind.Arith, Kind.Right):
2105 # Id.Right_DollarDParen IS just a normal token, handled by ArithParser
2106 self._SetNext(lex_mode_e.Arith)
2107 return self.cur_token
2108
2109 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub):
2110 return self._ReadCompoundWord(lex_mode_e.Arith)
2111
2112 else:
2113 raise AssertionError(self.cur_token)
2114
2115 def _ReadWord(self, word_mode):
2116 # type: (lex_mode_t) -> Optional[word_t]
2117 """Helper function for ReadWord()."""
2118
2119 # Change the pseudo lexer mode to a real lexer mode
2120 if word_mode == lex_mode_e.ShCommandFakeBrack:
2121 lex_mode = lex_mode_e.ShCommand
2122 else:
2123 lex_mode = word_mode
2124
2125 self._GetToken()
2126
2127 if self.token_kind == Kind.Eof:
2128 # No advance
2129 return self.cur_token
2130
2131 elif self.token_kind == Kind.Redir:
2132 self._SetNext(lex_mode)
2133 # This is >out -- 3>out is handled below
2134 return word.Redir(None, self.cur_token)
2135
2136 # Allow Arith for ) at end of for loop?
2137 elif self.token_kind in (Kind.Op, Kind.Arith):
2138 self._SetNext(lex_mode)
2139
2140 # Newlines are complicated. See 3x2 matrix in the comment about
2141 # self.multiline and self.newline_state above.
2142 if self.token_type == Id.Op_Newline:
2143 if self.multiline:
2144 if self.newline_state > 1:
2145 # This points at a blank line, but at least it gives the line number
2146 p_die('Invalid blank line in multiline mode',
2147 self.cur_token)
2148 return None
2149
2150 if self.returned_newline: # skip
2151 return None
2152
2153 return self.cur_token
2154
2155 elif self.token_kind == Kind.Right:
2156 if self.token_type not in (Id.Right_Subshell, Id.Right_ShFunction,
2157 Id.Right_CasePat, Id.Right_Initializer):
2158 raise AssertionError(self.cur_token)
2159
2160 self._SetNext(lex_mode)
2161 return self.cur_token
2162
2163 elif self.token_kind in (Kind.Ignored, Kind.WS):
2164 self._SetNext(lex_mode)
2165 return None
2166
2167 else:
2168 assert self.token_kind in (Kind.VSub, Kind.Lit, Kind.History,
2169 Kind.Left, Kind.KW, Kind.ControlFlow,
2170 Kind.BoolUnary, Kind.BoolBinary,
2171 Kind.ExtGlob,
2172 Kind.BashRegex), 'Unhandled token kind'
2173
2174 if (word_mode == lex_mode_e.ShCommandFakeBrack and
2175 self.parse_opts.parse_bracket() and
2176 self.token_type == Id.Lit_LBracket):
2177 # Change [ from Kind.Lit -> Kind.Op
2178 # So CommandParser can treat
2179 # assert [42 === x]
2180 # like
2181 # json write (x)
2182 bracket_word = self.cur_token
2183 bracket_word.id = Id.Op_LBracket
2184
2185 self._SetNext(lex_mode)
2186 return bracket_word
2187
2188 # We're beginning a word. If we see Id.Lit_Pound, change to
2189 # lex_mode_e.Comment and read until end of line.
2190 if self.token_type == Id.Lit_Pound:
2191 self._SetNext(lex_mode_e.Comment)
2192 self._GetToken()
2193
2194 # NOTE: The # could be the last character in the file. It can't be
2195 # Eof_{RParen,Backtick} because #) and #` are comments.
2196 assert self.token_type in (Id.Ignored_Comment, Id.Eof_Real), \
2197 self.cur_token
2198
2199 # The next iteration will go into Kind.Ignored and set lex state to
2200 # lex_mode_e.ShCommand/etc.
2201 return None # tell ReadWord() to try again after comment
2202
2203 elif self.token_type == Id.Lit_TPound: ### doc comment
2204 self._SetNext(lex_mode_e.Comment)
2205 self._GetToken()
2206
2207 if self.token_type == Id.Ignored_Comment and self.emit_doc_token:
2208 return self.cur_token
2209
2210 return None # tell ReadWord() to try again after comment
2211
2212 else:
2213 # r'' u'' b'' at the beginning of a word
2214 if (self.token_type == Id.Lit_Chars and
2215 self.lexer.LookAheadOne(
2216 lex_mode_e.ShCommand) == Id.Left_SingleQuote):
2217
2218 # When shopt -s parse_ysh_string:
2219 # echo r'hi' is like echo 'hi'
2220 #
2221 # echo u'\u{3bc}' b'\yff' works
2222
2223 tok = self.cur_token
2224 if self.parse_opts.parse_ysh_string():
2225 if lexer.TokenEquals(tok, 'r'):
2226 left_id = Id.Left_RSingleQuote
2227 elif lexer.TokenEquals(tok, 'u'):
2228 left_id = Id.Left_USingleQuote
2229 elif lexer.TokenEquals(tok, 'b'):
2230 left_id = Id.Left_BSingleQuote
2231 else:
2232 left_id = Id.Undefined_Tok
2233
2234 if left_id != Id.Undefined_Tok:
2235 # skip the r, and then 'foo' will be read as normal
2236 self._SetNext(lex_mode_e.ShCommand)
2237
2238 self._GetToken()
2239 assert self.token_type == Id.Left_SingleQuote, self.token_type
2240
2241 # Read the word in a different lexer mode
2242 return self._ReadYshSingleQuoted(left_id)
2243
2244 return self._ReadCompoundOrRedir(lex_mode)
2245
2246 def ParseVarRef(self):
2247 # type: () -> BracedVarSub
2248 """DYNAMIC parsing of what's inside ${!ref}
2249
2250 # Same as VarOf production
2251 VarRefExpr = VarOf EOF
2252 """
2253 self._SetNext(lex_mode_e.VSub_1)
2254
2255 self._GetToken()
2256 if self.token_kind != Kind.VSub:
2257 p_die('Expected var name', self.cur_token)
2258
2259 part = self._ParseVarOf()
2260 # NOTE: no ${ } means no part.left and part.right
2261 part.left = part.name_tok # cheat to make test pass
2262 part.right = part.name_tok
2263
2264 self._GetToken()
2265 if self.token_type != Id.Eof_Real:
2266 p_die('Expected end of var ref expression', self.cur_token)
2267 return part
2268
2269 def LookPastSpace(self):
2270 # type: () -> Id_t
2271 """Look ahead to the next token.
2272
2273 For the CommandParser to recognize
2274 array= (1 2 3)
2275 YSH for ( versus bash for ((
2276 YSH if ( versus if test
2277 YSH while ( versus while test
2278 YSH bare assignment 'grep =' versus 'grep foo'
2279 """
2280 assert self.token_type != Id.Undefined_Tok
2281 if self.cur_token.id == Id.WS_Space:
2282 id_ = self.lexer.LookPastSpace(lex_mode_e.ShCommand)
2283 else:
2284 id_ = self.cur_token.id
2285 return id_
2286
2287 def LookAheadDParens(self, shift_back=0):
2288 # type: (int) -> bool
2289 """Special lookahead for (( )), to make sure it's an arithmetic
2290 expression (i.e. that the closing parens are a single token, not
2291 separated by anything).
2292 """
2293 assert self.token_type in (Id.Op_DLeftParen, Id.Left_DollarDParen)
2294
2295 return self.lexer.LookAheadDParens(shift_back)
2296
2297 def LookAheadFuncParens(self):
2298 # type: () -> bool
2299 """Special lookahead for f( ) { echo hi; } to check for ( )"""
2300 assert self.token_type != Id.Undefined_Tok
2301
2302 # We have to handle 2 cases because we buffer a token
2303 if self.cur_token.id == Id.Op_LParen: # saw funcname(
2304 return self.lexer.LookAheadFuncParens(1) # go back one char
2305
2306 elif self.cur_token.id == Id.WS_Space: # saw funcname WHITESPACE
2307 return self.lexer.LookAheadFuncParens(0)
2308
2309 else:
2310 return False
2311
2312 def ReadWord(self, word_mode):
2313 # type: (lex_mode_t) -> word_t
2314 """Read the next word, using the given lexer mode.
2315
2316 This is a stateful wrapper for the stateless _ReadWord function.
2317 """
2318 assert word_mode in (lex_mode_e.ShCommand,
2319 lex_mode_e.ShCommandFakeBrack,
2320 lex_mode_e.DBracket, lex_mode_e.BashRegex)
2321
2322 if self.buffered_word: # For integration with pgen2
2323 w = self.buffered_word
2324 self.buffered_word = None
2325 else:
2326 while True:
2327 w = self._ReadWord(word_mode)
2328 if w is not None:
2329 break
2330
2331 self.returned_newline = (word_.CommandId(w) == Id.Op_Newline)
2332 return w
2333
2334 def ReadArithWord(self):
2335 # type: () -> word_t
2336 while True:
2337 w = self._ReadArithWord()
2338 if w is not None:
2339 break
2340 return w
2341
2342 def ReadHereDocBody(self, parts):
2343 # type: (List[word_part_t]) -> None
2344 """
2345 A here doc is like a double quoted context, except " and \" aren't special.
2346 """
2347 self._ReadLikeDQ(None, False, parts)
2348 # Returns nothing
2349
2350 def ReadForPlugin(self):
2351 # type: () -> CompoundWord
2352 """For $PS1, $PS4, etc.
2353
2354 This is just like reading a here doc line. "\n" is allowed, as
2355 well as the typical substitutions ${x} $(echo hi) $((1 + 2)).
2356 """
2357 w = CompoundWord([])
2358 self._ReadLikeDQ(None, False, w.parts)
2359 return w
2360
2361 def EmitDocToken(self, b):
2362 # type: (bool) -> None
2363 self.emit_doc_token = b
2364
2365 def Multiline(self, b):
2366 # type: (bool) -> None
2367 self.multiline = b
2368
2369
2370if 0:
2371 import collections
2372 WORD_HIST = collections.Counter()
2373
2374# vim: sw=4