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_subexpr_shorthand():
842 return self._ReadExprSub(lex_mode_e.DQ)
843 else:
844 return self._ReadArithSub(backwards_compatible=True)
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_subexpr_shorthand():
978 return self._ReadExprSub(lex_mode_e.ShCommand)
979 else:
980 return self._ReadArithSub(backwards_compatible=True)
981
982 if self.token_type == Id.Left_DollarBraceZsh:
983 return self._ReadZshVarSub(self.cur_token)
984
985 raise AssertionError(self.cur_token)
986
987 def _ReadExtGlob(self):
988 # type: () -> word_part.ExtGlob
989 """
990 Grammar:
991 Item = CompoundWord | EPSILON # important: @(foo|) is allowed
992 LEFT = '@(' | '*(' | '+(' | '?(' | '!('
993 RIGHT = ')'
994 ExtGlob = LEFT (Item '|')* Item RIGHT # ITEM may be empty
995 Compound includes ExtGlob
996 """
997 left_token = self.cur_token
998 right_token = None # type: Token
999 arms = [] # type: List[CompoundWord]
1000
1001 self.lexer.PushHint(Id.Op_RParen, Id.Right_ExtGlob)
1002 self._SetNext(lex_mode_e.ExtGlob) # advance past LEFT
1003
1004 read_word = False # did we just a read a word? To handle @(||).
1005
1006 while True:
1007 self._GetToken()
1008
1009 if self.token_type == Id.Right_ExtGlob:
1010 if not read_word:
1011 arms.append(CompoundWord([]))
1012 right_token = self.cur_token
1013 break
1014
1015 elif self.token_type == Id.Op_Pipe:
1016 if not read_word:
1017 arms.append(CompoundWord([]))
1018 read_word = False
1019 self._SetNext(lex_mode_e.ExtGlob)
1020
1021 # lex_mode_e.ExtGlob should only produce these 4 kinds of tokens
1022 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub,
1023 Kind.ExtGlob):
1024 w = self._ReadCompoundWord(lex_mode_e.ExtGlob)
1025 arms.append(w)
1026 read_word = True
1027
1028 elif self.token_kind == Kind.Eof:
1029 p_die('Unexpected EOF reading extended glob that began here',
1030 left_token)
1031
1032 else:
1033 raise AssertionError(self.cur_token)
1034
1035 return word_part.ExtGlob(left_token, arms, right_token)
1036
1037 def _ReadBashRegexGroup(self):
1038 # type: () -> word_part.BashRegexGroup
1039 """
1040 Grammar:
1041 BashRegexGroup = '(' WORD? ')
1042 """
1043 left_token = self.cur_token
1044 assert left_token.id == Id.BashRegex_LParen, left_token
1045
1046 arms = [] # type: List[CompoundWord]
1047
1048 self.lexer.PushHint(Id.Op_RParen, Id.Right_BashRegexGroup)
1049 self._SetNext(lex_mode_e.BashRegexFakeInner) # advance past LEFT
1050
1051 self._GetToken()
1052 if self.token_type == Id.Right_BashRegexGroup: # empty ()
1053 return word_part.BashRegexGroup(left_token, None, self.cur_token)
1054
1055 # lex_mode_e.BashRegex should only produce these 4 kinds of tokens
1056 if self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub, Kind.BashRegex):
1057 # Fake lexer mode that translates Id.WS_Space to Id.Lit_Chars
1058 # To allow bash style [[ s =~ (a b) ]]
1059 w = self._ReadCompoundWord(lex_mode_e.BashRegexFakeInner)
1060 arms.append(w)
1061
1062 self._GetToken()
1063 if self.token_type != Id.Right_BashRegexGroup:
1064 p_die('Expected ) to close bash regex group', self.cur_token)
1065
1066 return word_part.BashRegexGroup(left_token, w, self.cur_token)
1067
1068 p_die('Expected word after ( opening bash regex group', self.cur_token)
1069
1070 def _ReadLikeDQ(self, left_token, is_ysh_expr, out_parts):
1071 # type: (Optional[Token], bool, List[word_part_t]) -> None
1072 """
1073 Args:
1074 left_token: A token if we are reading a double quoted part, or None if
1075 we're reading a here doc.
1076 is_ysh_expr: Whether to disallow backticks and invalid char escapes
1077 out_parts: list of word_part to append to
1078 """
1079 if left_token:
1080 if left_token.id in (Id.Left_TDoubleQuote,
1081 Id.Left_DollarTDoubleQuote):
1082 expected_end_tokens = 3
1083 else:
1084 expected_end_tokens = 1
1085 else:
1086 expected_end_tokens = 1000 # here doc will break
1087
1088 num_end_tokens = 0
1089 while num_end_tokens < expected_end_tokens:
1090 self._SetNext(lex_mode_e.DQ)
1091 self._GetToken()
1092
1093 if self.token_kind == Kind.Lit:
1094 if self.token_type == Id.Lit_EscapedChar:
1095 tok = self.cur_token
1096 ch = lexer.TokenSliceLeft(tok, 1)
1097 part = word_part.EscapedLiteral(tok,
1098 ch) # type: word_part_t
1099 else:
1100 if self.token_type == Id.Lit_BadBackslash:
1101 # echo "\z" is OK in shell, but 'x = "\z" is a syntax error in
1102 # YSH.
1103 # Slight hole: We don't catch 'x = ${undef:-"\z"} because of the
1104 # recursion (unless no_parse_backslash)
1105 if (is_ysh_expr or
1106 self.parse_opts.no_parse_backslash()):
1107 p_die(
1108 "Invalid char escape in double quoted string (OILS-ERR-12)",
1109 self.cur_token)
1110 elif self.token_type == Id.Lit_Dollar:
1111 if is_ysh_expr or self.parse_opts.no_parse_dollar():
1112 p_die("Literal $ should be quoted like \$",
1113 self.cur_token)
1114
1115 part = self.cur_token
1116 out_parts.append(part)
1117
1118 elif self.token_kind == Kind.Left:
1119 if self.token_type == Id.Left_Backtick and is_ysh_expr:
1120 p_die("Backtick should be $(cmd) or \\` (OILS-ERR-18)",
1121 self.cur_token)
1122
1123 part = self._ReadDoubleQuotedLeftParts()
1124 out_parts.append(part)
1125
1126 elif self.token_kind == Kind.VSub:
1127 tok = self.cur_token
1128 part = SimpleVarSub(tok)
1129 out_parts.append(part)
1130 # NOTE: parsing "$f(x)" would BREAK CODE. Could add a more for it
1131 # later.
1132
1133 elif self.token_kind == Kind.Right:
1134 assert self.token_type == Id.Right_DoubleQuote, self.token_type
1135 if left_token:
1136 num_end_tokens += 1
1137
1138 # In a here doc, the right quote is literal!
1139 out_parts.append(self.cur_token)
1140
1141 elif self.token_kind == Kind.Eof:
1142 if left_token:
1143 p_die(
1144 'Unexpected EOF reading double-quoted string that began here',
1145 left_token)
1146 else: # here docs will have an EOF in their token stream
1147 break
1148
1149 else:
1150 raise AssertionError(self.cur_token)
1151
1152 if self.token_kind != Kind.Right:
1153 num_end_tokens = 0 # """ must be CONSECUTIVE
1154
1155 if expected_end_tokens == 1:
1156 out_parts.pop()
1157 elif expected_end_tokens == 3:
1158 out_parts.pop()
1159 out_parts.pop()
1160 out_parts.pop()
1161
1162 # Remove space from """ in both expression mode and command mode
1163 if (left_token and left_token.id
1164 in (Id.Left_TDoubleQuote, Id.Left_DollarTDoubleQuote)):
1165 word_compile.RemoveLeadingSpaceDQ(out_parts)
1166
1167 # Return nothing, since we appended to 'out_parts'
1168
1169 def _ReadDoubleQuoted(self, left_token):
1170 # type: (Token) -> DoubleQuoted
1171 """Helper function for "hello $name".
1172
1173 Args:
1174 eof_type: for stopping at }, Id.Lit_RBrace
1175 here_doc: Whether we are reading in a here doc context
1176
1177 Also ${foo%%a b c} # treat this as double quoted. until you hit
1178 """
1179 parts = [] # type: List[word_part_t]
1180 self._ReadLikeDQ(left_token, False, parts)
1181
1182 right_quote = self.cur_token
1183 return DoubleQuoted(left_token, parts, right_quote)
1184
1185 def ReadDoubleQuoted(self, left_token, parts):
1186 # type: (Token, List[word_part_t]) -> Token
1187 """For expression mode.
1188
1189 Read var x = "${dir:-}/$name"; etc.
1190 """
1191 self._ReadLikeDQ(left_token, True, parts)
1192 return self.cur_token
1193
1194 def _ReadCommandSub(self, left_id, d_quoted=False):
1195 # type: (Id_t, bool) -> CommandSub
1196 """
1197 NOTE: This is not in the grammar, because word parts aren't in the grammar!
1198
1199 command_sub = '$(' command_list ')'
1200 | '@(' command_list ')'
1201 | '<(' command_list ')'
1202 | '>(' command_list ')'
1203 | ` command_list `
1204 """
1205 left_token = self.cur_token
1206
1207 # Set the lexer in a state so ) becomes the EOF token.
1208 if left_id in (Id.Left_DollarParen, Id.Left_AtParen, Id.Left_ProcSubIn,
1209 Id.Left_ProcSubOut):
1210 self._SetNext(lex_mode_e.ShCommand) # advance past $( etc.
1211
1212 right_id = Id.Eof_RParen
1213 self.lexer.PushHint(Id.Op_RParen, right_id)
1214 c_parser = self.parse_ctx.MakeParserForCommandSub(
1215 self.line_reader, self.lexer, right_id)
1216 # NOTE: This doesn't use something like main_loop because we don't want
1217 # to interleave parsing and execution! Unlike 'source' and 'eval'.
1218 node = c_parser.ParseCommandSub()
1219
1220 right_token = c_parser.w_parser.cur_token
1221
1222 elif left_id == Id.Left_Backtick and self.parse_ctx.do_lossless:
1223 # NOTE: This is an APPROXIMATE solution for translation ONLY. See
1224 # test/osh2oil.
1225
1226 right_id = Id.Eof_Backtick
1227 self.lexer.PushHint(Id.Left_Backtick, right_id)
1228 c_parser = self.parse_ctx.MakeParserForCommandSub(
1229 self.line_reader, self.lexer, right_id)
1230 node = c_parser.ParseCommandSub()
1231 right_token = c_parser.w_parser.cur_token
1232
1233 elif left_id == Id.Left_Backtick:
1234 if self.parse_opts.no_parse_backticks():
1235 p_die(
1236 'Backtick should be $(cmd) or \\` (no_parse_backticks, OILS-ERR-18)',
1237 left_token)
1238
1239 self._SetNext(lex_mode_e.Backtick) # advance past `
1240
1241 parts = [] # type: List[str]
1242 while True:
1243 self._GetToken()
1244 #log("TOK %s", self.cur_token)
1245
1246 if self.token_type == Id.Backtick_Quoted:
1247 # Remove leading \
1248 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1249
1250 elif self.token_type == Id.Backtick_DoubleQuote:
1251 # Compatibility: If backticks are double quoted, then double quotes
1252 # within them have to be \"
1253 # Shells aren't smart enough to match nested " and ` quotes (but OSH
1254 # is)
1255 if d_quoted:
1256 # Remove leading \
1257 parts.append(lexer.TokenSliceLeft(self.cur_token, 1))
1258 else:
1259 parts.append(lexer.TokenVal(self.cur_token))
1260
1261 elif self.token_type == Id.Backtick_Other:
1262 parts.append(lexer.TokenVal(self.cur_token))
1263
1264 elif self.token_type == Id.Backtick_Right:
1265 break
1266
1267 elif self.token_type == Id.Eof_Real:
1268 # Note: this parse error is in the ORIGINAL context. No code_str yet.
1269 p_die('Unexpected EOF while looking for closing backtick',
1270 left_token)
1271
1272 else:
1273 raise AssertionError(self.cur_token)
1274
1275 self._SetNext(lex_mode_e.Backtick)
1276
1277 # Calculate right SPID on CommandSub BEFORE re-parsing.
1278 right_token = self.cur_token
1279
1280 code_str = ''.join(parts)
1281 #log('code %r', code_str)
1282
1283 # Save lines into a new, temporary arena, so SnipCodeBlock() isn't
1284 # messed up. Note: This is similar to how we parse aliases in
1285 # osh/cmd_parse.py. It won't have the same location info as
1286 # MakeParserForCommandSub(), because the reader is different.
1287 arena = alloc.Arena()
1288 # TODO: arena.PushSource()?
1289
1290 line_reader = reader.StringLineReader(code_str, arena)
1291 c_parser = self.parse_ctx.MakeOshParser(line_reader)
1292 src = source.Reparsed('backticks', left_token, right_token)
1293 with alloc.ctx_SourceCode(arena, src):
1294 node = c_parser.ParseCommandSub()
1295
1296 else:
1297 raise AssertionError(left_id)
1298
1299 return CommandSub(left_token, node, right_token)
1300
1301 def _ReadExprSub(self, lex_mode):
1302 # type: (lex_mode_t) -> ExprSub
1303 """$[d->key] $[obj.method()] etc."""
1304 left_token = self.cur_token
1305
1306 self._SetNext(lex_mode_e.Expr)
1307 enode, right_token = self.parse_ctx.ParseYshExpr(
1308 self.lexer, grammar_nt.ysh_expr_sub)
1309
1310 self._SetNext(lex_mode) # Move past ]
1311 return ExprSub(left_token, enode, right_token)
1312
1313 def ParseVarDecl(self, kw_token):
1314 # type: (Token) -> VarDecl
1315 """
1316 oil_var_decl: name_type_list '=' testlist end_stmt
1317
1318 Note that assignments must end with \n ; } or EOF. Unlike shell
1319 assignments, we disallow:
1320
1321 var x = 42 | wc -l
1322 var x = 42 && echo hi
1323 """
1324 self._SetNext(lex_mode_e.Expr)
1325 enode, last_token = self.parse_ctx.ParseVarDecl(kw_token, self.lexer)
1326 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1327 # wants
1328 if last_token.id == Id.Op_RBrace:
1329 last_token.id = Id.Lit_RBrace
1330
1331 # Let the CommandParser see the Op_Semi or Op_Newline.
1332 self.buffered_word = last_token
1333 self._SetNext(lex_mode_e.ShCommand) # always back to this
1334 return enode
1335
1336 def ParseMutation(self, kw_token, var_checker):
1337 # type: (Token, VarChecker) -> Mutation
1338 """
1339 setvar i = 42
1340 setvar i += 1
1341 setvar a[i] = 42
1342 setvar a[i] += 1
1343 setvar d.key = 42
1344 setvar d.key += 1
1345 """
1346 self._SetNext(lex_mode_e.Expr)
1347 enode, last_token = self.parse_ctx.ParseMutation(kw_token, self.lexer)
1348 # Hack to move } from what the Expr lexer modes gives to what CommandParser
1349 # wants
1350 if last_token.id == Id.Op_RBrace:
1351 last_token.id = Id.Lit_RBrace
1352
1353 for lhs in enode.lhs:
1354 UP_lhs = lhs
1355 with tagswitch(lhs) as case:
1356 if case(y_lhs_e.Var):
1357 lhs = cast(Token, UP_lhs)
1358 var_checker.Check(kw_token.id, lexer.LazyStr(lhs), lhs)
1359
1360 # Note: this does not cover cases like
1361 # setvar (a[0])[1] = v
1362 # setvar (d.key).other = v
1363 # This leaks into catching all typos statically, which may be
1364 # possible if 'use' makes all names explicit.
1365 elif case(y_lhs_e.Subscript):
1366 lhs = cast(Subscript, UP_lhs)
1367 if lhs.obj.tag() == expr_e.Var:
1368 v = cast(expr.Var, lhs.obj)
1369 var_checker.Check(kw_token.id, v.name, v.left)
1370
1371 elif case(y_lhs_e.Attribute):
1372 lhs = cast(Attribute, UP_lhs)
1373 if lhs.obj.tag() == expr_e.Var:
1374 v = cast(expr.Var, lhs.obj)
1375 var_checker.Check(kw_token.id, v.name, v.left)
1376
1377 # Let the CommandParser see the Op_Semi or Op_Newline.
1378 self.buffered_word = last_token
1379 self._SetNext(lex_mode_e.ShCommand) # always back to this
1380 return enode
1381
1382 def ParseBareDecl(self):
1383 # type: () -> expr_t
1384 """
1385 x = {name: val}
1386 """
1387 self._SetNext(lex_mode_e.Expr)
1388 self._GetToken()
1389 enode, last_token = self.parse_ctx.ParseYshExpr(
1390 self.lexer, grammar_nt.command_expr)
1391 if last_token.id == Id.Op_RBrace:
1392 last_token.id = Id.Lit_RBrace
1393 self.buffered_word = last_token
1394 self._SetNext(lex_mode_e.ShCommand)
1395 return enode
1396
1397 def ParseYshExprForCommand(self):
1398 # type: () -> expr_t
1399
1400 # Fudge for this case
1401 # for x in(y) {
1402 # versus
1403 # for x in (y) {
1404 #
1405 # In the former case, ReadWord on 'in' puts the lexer past (.
1406 # Also see LookPastSpace in CommandParers.
1407 # A simpler solution would be nicer.
1408
1409 if self.token_type == Id.Op_LParen:
1410 self.lexer.MaybeUnreadOne()
1411
1412 enode, _ = self.parse_ctx.ParseYshExpr(self.lexer, grammar_nt.ysh_expr)
1413
1414 self._SetNext(lex_mode_e.ShCommand)
1415 return enode
1416
1417 def ParseCommandExpr(self):
1418 # type: () -> expr_t
1419 """
1420 = 1+2
1421 """
1422 enode, last_token = self.parse_ctx.ParseYshExpr(
1423 self.lexer, grammar_nt.command_expr)
1424
1425 # In some cases, such as the case statement, we expect *the lexer* to be
1426 # pointing at the token right after the expression. But the expression
1427 # parser must have read to the `last_token`. Unreading places the lexer
1428 # back in the expected state. Ie:
1429 #
1430 # case (x) { case (x) {
1431 # (else) { = x } (else) { = x }
1432 # ^ The lexer is here ^ Unread to here
1433 # } }
1434 assert last_token.id in (Id.Op_Newline, Id.Eof_Real, Id.Op_Semi,
1435 Id.Op_RBrace), last_token
1436 if last_token.id != Id.Eof_Real:
1437 # Eof_Real is the only token we cannot unread
1438 self.lexer.MaybeUnreadOne()
1439
1440 return enode
1441
1442 def ParseProc(self, node):
1443 # type: (Proc) -> None
1444
1445 # proc name-with-hyphens() must be accepted
1446 self._SetNext(lex_mode_e.ShCommand)
1447 self._GetToken()
1448 # example: 'proc f[' gets you Lit_ArrayLhsOpen
1449 if self.token_type != Id.Lit_Chars:
1450 p_die('Invalid proc name %s' % ui.PrettyToken(self.cur_token),
1451 self.cur_token)
1452
1453 # TODO: validate this more. Disallow proc 123 { }, which isn't disallowed
1454 # for shell functions. Similar to IsValidVarName().
1455 node.name = self.cur_token
1456
1457 last_token = self.parse_ctx.ParseProc(self.lexer, node)
1458
1459 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1460 assert last_token.id == Id.Op_LBrace
1461 last_token.id = Id.Lit_LBrace
1462 self.buffered_word = last_token
1463
1464 self._SetNext(lex_mode_e.ShCommand)
1465
1466 def ParseFunc(self, node):
1467 # type: (Func) -> None
1468 last_token = self.parse_ctx.ParseFunc(self.lexer, node)
1469
1470 # Translate from lex_mode_e.{Expr => ShCommand}, for CommandParser
1471 assert last_token.id == Id.Op_LBrace
1472 last_token.id = Id.Lit_LBrace
1473 self.buffered_word = last_token
1474
1475 self._SetNext(lex_mode_e.ShCommand)
1476
1477 def ParseYshCasePattern(self):
1478 # type: () -> Tuple[pat_t, Token]
1479 pat, left_tok, last_token = self.parse_ctx.ParseYshCasePattern(
1480 self.lexer)
1481
1482 if last_token.id == Id.Op_LBrace:
1483 last_token.id = Id.Lit_LBrace
1484 self.buffered_word = last_token
1485
1486 return pat, left_tok
1487
1488 def NewlineOkForYshCase(self):
1489 # type: () -> Id_t
1490 """Check for optional newline and consume it.
1491
1492 This is a special case of `_NewlineOk` which fixed some "off-by-one" issues
1493 which crop up while parsing Ysh Case Arms. For more details, see
1494 #oil-dev > Progress On YSH Case Grammar on zulip.
1495
1496 Returns a token id which is filled with the choice of
1497
1498 word { echo word }
1499 (3) { echo expr }
1500 /e/ { echo eggex }
1501 } # right brace
1502 """
1503 while True:
1504 next_id = self.lexer.LookAheadOne(lex_mode_e.Expr)
1505
1506 # Cannot lookahead past lines
1507 if next_id == Id.Unknown_Tok:
1508 if not self.lexer.MoveToNextLine(): # Try to move to next line
1509 break # EOF
1510 continue
1511
1512 next_kind = consts.GetKind(next_id)
1513 if next_id != Id.Op_Newline and next_kind != Kind.Ignored:
1514 break
1515
1516 self.lexer.Read(lex_mode_e.Expr)
1517
1518 if next_id in (Id.Op_RBrace, Id.Op_LParen, Id.Arith_Slash):
1519 self._SetNext(lex_mode_e.Expr) # Continue in expression mode
1520 else:
1521 # Consume the trailing Op_Newline
1522 self._SetNext(lex_mode_e.ShCommand)
1523 self._GetToken()
1524
1525 return next_id
1526
1527 def _ReadArithExpr(self, end_id):
1528 # type: (Id_t) -> arith_expr_t
1529 """Read and parse an arithmetic expression in various contexts.
1530
1531 $(( 1+2 ))
1532 (( a=1+2 ))
1533 ${a[ 1+2 ]}
1534 ${a : 1+2 : 1+2}
1535
1536 See tests/arith-context.test.sh for ambiguous cases.
1537
1538 ${a[a[0]]} is valid # VS_RBRACKET vs Id.Arith_RBracket
1539
1540 ${s : a<b?0:1 : 1} # VS_COLON vs Id.Arith_Colon
1541
1542 See the assertion in ArithParser.Parse() -- unexpected extra input.
1543 """
1544 # calls self.ReadWord(lex_mode_e.Arith)
1545 anode = self.a_parser.Parse()
1546 cur_id = self.a_parser.CurrentId()
1547 if end_id != Id.Undefined_Tok and cur_id != end_id:
1548 p_die(
1549 'Unexpected token after arithmetic expression (%s != %s)' %
1550 (ui.PrettyId(cur_id), ui.PrettyId(end_id)),
1551 loc.Word(self.a_parser.cur_word))
1552 return anode
1553
1554 def _ReadArithSub(self, backwards_compatible=False):
1555 # type: (bool) -> word_part.ArithSub
1556 """Read an arith substitution, which contains an arith expression, e.g.
1557
1558 $((a + 1)).
1559 """
1560 left_tok = self.cur_token
1561
1562 # The second one needs to be disambiguated in stuff like stuff like:
1563 # $(echo $(( 1+2 )) )
1564 self.lexer.PushHint(Id.Op_RParen, Id.Right_DollarDParen)
1565
1566 # NOTE: To disambiguate $(( as arith sub vs. command sub and subshell, we
1567 # could save the lexer/reader state here, and retry if the arithmetic parse
1568 # fails. But we can almost always catch this at parse time. There could
1569 # be some exceptions like:
1570 # $((echo * foo)) # looks like multiplication
1571 # $((echo / foo)) # looks like division
1572
1573 # $(( )) is valid
1574 anode = arith_expr.EmptyZero # type: arith_expr_t
1575
1576 self._NextNonSpace()
1577 if self.token_type != Id.Arith_RParen:
1578 endid = Id.Arith_RBracket if backwards_compatible else Id.Arith_RParen
1579 anode = self._ReadArithExpr(endid)
1580
1581 self._SetNext(lex_mode_e.ShCommand)
1582
1583 if not backwards_compatible:
1584 # Ensure we get closing ) if we are looking for double ))
1585 # (In backwards compat mode, ] can also be the closing bracket, and
1586 # it would already be the current token, no need to skip further
1587 self._GetToken()
1588 if self.token_type != Id.Right_DollarDParen:
1589 p_die('Expected second ) to end arith sub', self.cur_token)
1590
1591 right_tok = self.cur_token
1592 return word_part.ArithSub(left_tok, anode, right_tok)
1593
1594 def ReadDParen(self):
1595 # type: () -> Tuple[arith_expr_t, Token]
1596 """Read ((1+ 2)) -- command context.
1597
1598 We're using the word parser because it's very similar to _ReadArithExpr
1599 above.
1600
1601 This also returns the terminating Id.Op_DRightParen token for location
1602 info.
1603 """
1604 # (( )) is valid
1605 anode = arith_expr.EmptyZero # type: arith_expr_t
1606
1607 self.lexer.PushHint(Id.Op_RParen, Id.Op_DRightParen)
1608
1609 self._NextNonSpace()
1610 if self.token_type != Id.Arith_RParen:
1611 anode = self._ReadArithExpr(Id.Arith_RParen)
1612
1613 self._SetNext(lex_mode_e.ShCommand)
1614
1615 # Ensure we get the second )
1616 self._GetToken()
1617 right = self.cur_token
1618 if right.id != Id.Op_DRightParen:
1619 p_die('Expected second ) to end arith statement', right)
1620
1621 self._SetNext(lex_mode_e.ShCommand)
1622
1623 return anode, right
1624
1625 def _NextNonSpace(self):
1626 # type: () -> None
1627 """Advance in lex_mode_e.Arith until non-space token.
1628
1629 Same logic as _ReadWord, but used in
1630 $(( ))
1631 (( ))
1632 for (( ))
1633
1634 You can read self.token_type after this, without calling _GetToken.
1635 """
1636 while True:
1637 self._SetNext(lex_mode_e.Arith)
1638 self._GetToken()
1639 if self.token_kind not in (Kind.Ignored, Kind.WS):
1640 break
1641
1642 def ReadForExpression(self):
1643 # type: () -> command.ForExpr
1644 """Read ((i=0; i<5; ++i)) -- part of command context."""
1645 self._NextNonSpace() # skip over ((
1646 cur_id = self.token_type # for end of arith expressions
1647
1648 if cur_id == Id.Arith_Semi: # for (( ; i < 10; i++ ))
1649 init_node = arith_expr.EmptyZero # type: arith_expr_t
1650 else:
1651 init_node = self.a_parser.Parse()
1652 cur_id = self.a_parser.CurrentId()
1653 self._NextNonSpace()
1654
1655 # It's odd to keep track of both cur_id and self.token_type in this
1656 # function, but it works, and is tested in 'test/parse_error.sh
1657 # arith-integration'
1658 if cur_id != Id.Arith_Semi: # for (( x=0 b; ... ))
1659 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1660
1661 self._GetToken()
1662 cur_id = self.token_type
1663
1664 if cur_id == Id.Arith_Semi: # for (( ; ; i++ ))
1665 # empty condition is TRUE
1666 cond_node = arith_expr.EmptyOne # type: arith_expr_t
1667 else:
1668 cond_node = self.a_parser.Parse()
1669 cur_id = self.a_parser.CurrentId()
1670
1671 if cur_id != Id.Arith_Semi: # for (( x=0; x<5 b ))
1672 p_die("Expected ; here", loc.Word(self.a_parser.cur_word))
1673
1674 self._NextNonSpace()
1675 if self.token_type == Id.Arith_RParen: # for (( ; ; ))
1676 update_node = arith_expr.EmptyZero # type: arith_expr_t
1677 else:
1678 update_node = self._ReadArithExpr(Id.Arith_RParen)
1679
1680 self._NextNonSpace()
1681 if self.token_type != Id.Arith_RParen:
1682 p_die('Expected ) to end for loop expression', self.cur_token)
1683 self._SetNext(lex_mode_e.ShCommand)
1684
1685 # redirects is None, will be assigned in CommandEvaluator
1686 node = command.ForExpr.CreateNull()
1687 node.init = init_node
1688 node.cond = cond_node
1689 node.update = update_node
1690 return node
1691
1692 def _ReadArrayLiteral(self):
1693 # type: () -> word_part_t
1694 """a=(1 2 3)
1695
1696 TODO: See osh/cmd_parse.py:164 for Id.Lit_ArrayLhsOpen, for a[x++]=1
1697
1698 We want:
1699
1700 A=(['x']=1 ["x"]=2 [$x$y]=3)
1701
1702 Maybe allow this as a literal string? Because I think I've seen it before?
1703 Or maybe force people to patch to learn the rule.
1704
1705 A=([x]=4)
1706
1707 Starts with Lit_Other '[', and then it has Lit_ArrayLhsClose
1708 Maybe enforce that ALL have keys or NONE of have keys.
1709 """
1710 self._SetNext(lex_mode_e.ShCommand) # advance past (
1711 self._GetToken()
1712 if self.cur_token.id != Id.Op_LParen:
1713 p_die('Expected ( after =', self.cur_token)
1714 left_token = self.cur_token
1715 right_token = None # type: Token
1716
1717 # MUST use a new word parser (with same lexer).
1718 w_parser = self.parse_ctx.MakeWordParser(self.lexer, self.line_reader)
1719 words = [] # type: List[CompoundWord]
1720 done = False
1721 while not done:
1722 w = w_parser.ReadWord(lex_mode_e.ShCommand)
1723 with tagswitch(w) as case:
1724 if case(word_e.Operator):
1725 tok = cast(Token, w)
1726 if tok.id == Id.Right_Initializer:
1727 right_token = tok
1728 done = True # can't use break here
1729 # Unlike command parsing, array parsing allows embedded \n.
1730 elif tok.id == Id.Op_Newline:
1731 continue
1732 else:
1733 p_die('Unexpected token in array literal', loc.Word(w))
1734
1735 elif case(word_e.Compound):
1736 words.append(cast(CompoundWord, w))
1737
1738 else:
1739 raise AssertionError()
1740
1741 initializer_words = [] # type: List[InitializerWord_t]
1742 for w in words:
1743 pair = word_.DetectAssocPair(w)
1744 if pair is not None:
1745 word_.TildeDetectAssign(pair.value) # pair.value is modified
1746 initializer_words.append(pair)
1747 else:
1748 w2 = braces.BraceDetect(w) # type: word_t
1749 if w2 is None:
1750 w2 = w
1751 w3 = word_.TildeDetect(w2) # type: word_t
1752 if w3 is None:
1753 w3 = w2
1754 initializer_words.append(InitializerWord.ArrayWord(w3))
1755
1756 # invariant List?
1757 return word_part.InitializerLiteral(left_token, initializer_words,
1758 right_token)
1759
1760 def ParseProcCallArgs(self, start_symbol):
1761 # type: (int) -> ArgList
1762 """ json write (x) """
1763 self.lexer.MaybeUnreadOne()
1764
1765 arg_list = ArgList.CreateNull(alloc_lists=True)
1766 arg_list.left = self.cur_token
1767 self.parse_ctx.ParseProcCallArgs(self.lexer, arg_list, start_symbol)
1768 return arg_list
1769
1770 def _MaybeReadWordPart(self, is_first, lex_mode, parts):
1771 # type: (bool, lex_mode_t, List[word_part_t]) -> bool
1772 """Helper for _ReadCompoundWord3."""
1773 done = False
1774
1775 if self.token_type == Id.Lit_EscapedChar:
1776 tok = self.cur_token
1777 assert tok.length == 2
1778 ch = lexer.TokenSliceLeft(tok, 1)
1779 if self.parse_opts.no_parse_backslash():
1780 if not pyutil.IsValidCharEscape(ch):
1781 p_die('Invalid char escape in unquoted word (OILS-ERR-13)',
1782 self.cur_token)
1783
1784 part = word_part.EscapedLiteral(self.cur_token,
1785 ch) # type: word_part_t
1786 else:
1787 part = self.cur_token
1788
1789 if is_first and self.token_type == Id.Lit_VarLike: # foo=
1790 parts.append(part)
1791 # Unfortunately it's awkward to pull the check for a=(1 2) up to
1792 # _ReadWord.
1793 next_id = self.lexer.LookPastSpace(lex_mode)
1794 if next_id == Id.Op_LParen:
1795 self.lexer.PushHint(Id.Op_RParen, Id.Right_Initializer)
1796 part2 = self._ReadArrayLiteral()
1797 parts.append(part2)
1798
1799 # Array literal must be the last part of the word.
1800 self._SetNext(lex_mode)
1801 self._GetToken()
1802 # EOF, whitespace, newline, Right_Subshell
1803 if self.token_kind not in KINDS_THAT_END_WORDS:
1804 p_die('Unexpected token after array literal',
1805 self.cur_token)
1806 done = True
1807
1808 elif (is_first and self.parse_opts.parse_at() and
1809 self.token_type == Id.Lit_Splice):
1810
1811 splice_tok = self.cur_token
1812 part2 = word_part.Splice(splice_tok,
1813 lexer.TokenSliceLeft(splice_tok, 1))
1814
1815 parts.append(part2)
1816
1817 # @words must be the last part of the word
1818 self._SetNext(lex_mode)
1819 self._GetToken()
1820 # EOF, whitespace, newline, Right_Subshell
1821 if self.token_kind not in KINDS_THAT_END_WORDS:
1822 p_die('Unexpected token after array splice', self.cur_token)
1823 done = True
1824
1825 elif (is_first and self.parse_opts.parse_at() and
1826 self.token_type == Id.Lit_AtLBracket): # @[split(x)]
1827 part2 = self._ReadExprSub(lex_mode_e.DQ)
1828 parts.append(part2)
1829
1830 # @[split(x)]
1831 self._SetNext(lex_mode)
1832 self._GetToken()
1833 # EOF, whitespace, newline, Right_Subshell
1834 if self.token_kind not in KINDS_THAT_END_WORDS:
1835 p_die('Unexpected token after Expr splice', self.cur_token)
1836 done = True
1837
1838 elif (is_first and self.parse_opts.parse_at() and
1839 self.token_type == Id.Lit_AtLBraceDot):
1840 p_die('TODO: @{.myproc builtin sub}', self.cur_token)
1841
1842 elif (is_first and self.parse_opts.parse_at_all() and
1843 self.token_type == Id.Lit_At):
1844 # Because $[x] ${x} and perhaps $/x/ are reserved, it makes sense for @
1845 # at the beginning of a word to be reserved.
1846
1847 # Although should we relax 'echo @' ? I'm tempted to have a shortcut for
1848 # @_argv and
1849 p_die('Literal @ starting a word must be quoted (parse_at_all)',
1850 self.cur_token)
1851
1852 else:
1853 # not a literal with lookahead; append it
1854 parts.append(part)
1855
1856 return done
1857
1858 def _ReadCompoundWord(self, lex_mode):
1859 # type: (lex_mode_t) -> CompoundWord
1860
1861 # This is the ONLY lexer mode that can return word.Redir
1862 assert lex_mode != lex_mode_e.ShCommand, lex_mode
1863
1864 w = self._ReadCompoundOrRedir(lex_mode)
1865 assert w.tag() == word_e.Compound, w
1866 return cast(CompoundWord, w)
1867
1868 def _ReadCompoundWord3(self, lex_mode, eof_type, empty_ok):
1869 # type: (lex_mode_t, Id_t, bool) -> 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._ReadCompoundOrRedir3(lex_mode, eof_type, empty_ok)
1875 assert w.tag() == word_e.Compound, w
1876 return cast(CompoundWord, w)
1877
1878 def _ReadCompoundOrRedir(self, lex_mode):
1879 # type: (lex_mode_t) -> word_t
1880 """Returns either word.Compound or word.Redir"""
1881 return self._ReadCompoundOrRedir3(lex_mode, Id.Undefined_Tok, True)
1882
1883 def _ReadCompoundOrRedir3(self, lex_mode, eof_type, empty_ok):
1884 # type: (lex_mode_t, Id_t, bool) -> word_t
1885 """
1886 Precondition: Looking at the first token of the first word part
1887 Postcondition: Looking at the token after, e.g. space or operator
1888
1889 NOTE: eof_type is necessary because / is a literal, i.e. Lit_Slash, but it
1890 could be an operator delimiting a compound word. Can we change lexer modes
1891 and remove this special case?
1892
1893 Returns either word.Compound or word.Redir
1894 """
1895 w = CompoundWord([])
1896 num_parts = 0
1897 brace_count = 0
1898 done = False
1899 is_triple_quoted = None # type: Optional[BoolParamBox]
1900 saw_redir_left_tok = False
1901
1902 while not done:
1903 self._GetToken()
1904
1905 allow_done = empty_ok or num_parts != 0
1906 if allow_done and self.token_type == eof_type:
1907 done = True # e.g. for ${foo//pat/replace}
1908
1909 # Keywords like "for" are treated like literals
1910 elif self.token_kind in (Kind.Lit, Kind.History, Kind.KW,
1911 Kind.ControlFlow, Kind.BoolUnary,
1912 Kind.BoolBinary):
1913
1914 # Syntax error for { and }
1915 if self.token_type == Id.Lit_LBrace:
1916 brace_count += 1
1917 elif self.token_type == Id.Lit_RBrace:
1918 brace_count -= 1
1919 elif self.token_type == Id.Lit_Dollar:
1920 if self.parse_opts.no_parse_dollar():
1921 if num_parts == 0 and lex_mode == lex_mode_e.ShCommand:
1922 next_byte = self.lexer.ByteLookAhead()
1923 # TODO: switch lexer modes and parse $/d+/. But not ${a:-$/d+/}
1924 if next_byte == '/':
1925 #log('next_byte %r', next_byte)
1926 pass
1927
1928 p_die(
1929 'Literal $ should be quoted like \$ (no_parse_dollar)',
1930 self.cur_token)
1931 elif self.token_type in (Id.Lit_Number, Id.Lit_RedirVarName):
1932 saw_redir_left_tok = True
1933
1934 done = self._MaybeReadWordPart(num_parts == 0, lex_mode,
1935 w.parts)
1936
1937 elif self.token_kind == Kind.VSub:
1938 vsub_token = self.cur_token
1939
1940 part = SimpleVarSub(vsub_token) # type: word_part_t
1941 w.parts.append(part)
1942
1943 elif self.token_kind == Kind.ExtGlob:
1944 # If parse_at, we can take over @( to start @(seq 3)
1945 # Users can also use look at ,(*.py|*.sh)
1946 if (self.parse_opts.parse_at() and
1947 self.token_type == Id.ExtGlob_At and num_parts == 0):
1948 cs_part = self._ReadCommandSub(Id.Left_AtParen,
1949 d_quoted=False)
1950 # RARE mutation of tok.id!
1951 cs_part.left_token.id = Id.Left_AtParen
1952 part = cs_part # for type safety
1953
1954 # Same check as _MaybeReadWordPart. @(seq 3)x is illegal, just like
1955 # a=(one two)x and @arrayfunc(3)x.
1956 self._GetToken()
1957 if self.token_kind not in KINDS_THAT_END_WORDS:
1958 p_die('Unexpected token after @()', self.cur_token)
1959 done = True
1960
1961 else:
1962 if HAVE_FNM_EXTMATCH == 0:
1963 p_die(
1964 "Extended glob won't work without FNM_EXTMATCH support in libc",
1965 self.cur_token)
1966 part = self._ReadExtGlob()
1967 w.parts.append(part)
1968
1969 elif self.token_kind == Kind.BashRegex:
1970 if self.token_type == Id.BashRegex_LParen: # Opening (
1971 part = self._ReadBashRegexGroup()
1972 w.parts.append(part)
1973 else:
1974 assert self.token_type == Id.BashRegex_AllowedInParens
1975 p_die('Invalid token in bash regex', self.cur_token)
1976
1977 elif self.token_kind == Kind.Left:
1978 try_triple_quote = (self.parse_opts.parse_triple_quote() and
1979 lex_mode == lex_mode_e.ShCommand and
1980 num_parts == 0)
1981
1982 # Save allocation
1983 if try_triple_quote:
1984 is_triple_quoted = BoolParamBox(False)
1985
1986 part = self._ReadUnquotedLeftParts(is_triple_quoted)
1987 w.parts.append(part)
1988
1989 # NOT done yet, will advance below
1990 elif self.token_kind == Kind.Right:
1991 # Still part of the word; will be done on the next iter.
1992 if self.token_type == Id.Right_DoubleQuote:
1993 pass
1994 # Never happens, no PushHint for this case.
1995 #elif self.token_type == Id.Right_DollarParen:
1996 # pass
1997 elif self.token_type == Id.Right_Subshell:
1998 # LEXER HACK for (case x in x) ;; esac )
1999 # Rewind before it's used
2000 assert self.next_lex_mode == lex_mode_e.Undefined
2001 if self.lexer.MaybeUnreadOne():
2002 self.lexer.PushHint(Id.Op_RParen, Id.Right_Subshell)
2003 self._SetNext(lex_mode)
2004 done = True
2005 else:
2006 done = True
2007
2008 elif self.token_kind == Kind.Redir:
2009 # Check if the previous token was a possible left_tok to a
2010 # redirect operator, attach it to the word.Redir. And return
2011 # it instead of the CompoundWord.
2012
2013 # &> and &>> don't have a leading descriptor (2 is implied)
2014 if (saw_redir_left_tok and num_parts == 1 and self.token_type
2015 not in (Id.Redir_AndGreat, Id.Redir_AndDGreat)):
2016
2017 self._SetNext(lex_mode)
2018 left_tok = cast(Token, w.parts.pop())
2019 r = word.Redir(left_tok, self.cur_token)
2020 return r # EARLY RETURN
2021
2022 done = True
2023
2024 elif self.token_kind == Kind.Ignored:
2025 done = True
2026
2027 else:
2028 # LEXER HACK for unbalanced case clause. 'case foo in esac' is valid,
2029 # so to test for ESAC, we can read ) before getting a chance to
2030 # PushHint(Id.Op_RParen, Id.Right_CasePat). So here we unread one
2031 # token and do it again.
2032
2033 # We get Id.Op_RParen at top level: case x in x) ;; esac
2034 # We get Id.Eof_RParen inside ComSub: $(case x in x) ;; esac )
2035 if self.token_type in (Id.Op_RParen, Id.Eof_RParen):
2036 # Rewind before it's used
2037 assert self.next_lex_mode == lex_mode_e.Undefined
2038 if self.lexer.MaybeUnreadOne():
2039 if self.token_type == Id.Eof_RParen:
2040 # Redo translation
2041 self.lexer.PushHint(Id.Op_RParen, Id.Eof_RParen)
2042 self._SetNext(lex_mode)
2043
2044 done = True # anything we don't recognize means we're done
2045
2046 if not done:
2047 self._SetNext(lex_mode)
2048 num_parts += 1
2049
2050 if (self.parse_opts.parse_brace() and num_parts > 1 and
2051 brace_count != 0):
2052 # accept { and }, but not foo{
2053 p_die(
2054 'Word has unbalanced { }. Maybe add a space or quote it like \{',
2055 loc.Word(w))
2056
2057 if is_triple_quoted and is_triple_quoted.b and num_parts > 1:
2058 p_die('Unexpected parts after triple quoted string',
2059 loc.WordPart(w.parts[-1]))
2060
2061 if 0:
2062 from _devbuild.gen.syntax_asdl import word_part_str
2063 word_key = ' '.join(word_part_str(p.tag()) for p in w.parts)
2064 WORD_HIST[word_key] += 1
2065
2066 # YSH word restriction
2067 # (r'' u'' b'' are stripped on shopt -s parse_ysh_string)
2068 if self.parse_opts.no_parse_word_join() and not _IsValidYshWord(w):
2069 p_die("Invalid quoted word part in YSH (OILS-ERR-17)",
2070 loc.WordPart(part))
2071
2072 return w
2073
2074 def _ReadArithWord(self):
2075 # type: () -> Optional[word_t]
2076 """ Helper for ReadArithWord() """
2077 self._GetToken()
2078
2079 if self.token_kind == Kind.Unknown:
2080 # e.g. happened during dynamic parsing of unset 'a[$foo]' in gherkin
2081 p_die(
2082 'Unexpected token while parsing arithmetic: %r' %
2083 lexer.TokenVal(self.cur_token), self.cur_token)
2084
2085 elif self.token_kind == Kind.Eof:
2086 return self.cur_token
2087
2088 elif self.token_kind == Kind.Ignored:
2089 # Space should be ignored.
2090 self._SetNext(lex_mode_e.Arith)
2091 return None
2092
2093 elif self.token_kind in (Kind.Arith, Kind.Right):
2094 # Id.Right_DollarDParen IS just a normal token, handled by ArithParser
2095 self._SetNext(lex_mode_e.Arith)
2096 return self.cur_token
2097
2098 elif self.token_kind in (Kind.Lit, Kind.Left, Kind.VSub):
2099 return self._ReadCompoundWord(lex_mode_e.Arith)
2100
2101 else:
2102 raise AssertionError(self.cur_token)
2103
2104 def _ReadWord(self, word_mode):
2105 # type: (lex_mode_t) -> Optional[word_t]
2106 """Helper function for ReadWord()."""
2107
2108 # Change the pseudo lexer mode to a real lexer mode
2109 if word_mode == lex_mode_e.ShCommandFakeBrack:
2110 lex_mode = lex_mode_e.ShCommand
2111 else:
2112 lex_mode = word_mode
2113
2114 self._GetToken()
2115
2116 if self.token_kind == Kind.Eof:
2117 # No advance
2118 return self.cur_token
2119
2120 elif self.token_kind == Kind.Redir:
2121 self._SetNext(lex_mode)
2122 # This is >out -- 3>out is handled below
2123 return word.Redir(None, self.cur_token)
2124
2125 # Allow Arith for ) at end of for loop?
2126 elif self.token_kind in (Kind.Op, Kind.Arith):
2127 self._SetNext(lex_mode)
2128
2129 # Newlines are complicated. See 3x2 matrix in the comment about
2130 # self.multiline and self.newline_state above.
2131 if self.token_type == Id.Op_Newline:
2132 if self.multiline:
2133 if self.newline_state > 1:
2134 # This points at a blank line, but at least it gives the line number
2135 p_die('Invalid blank line in multiline mode',
2136 self.cur_token)
2137 return None
2138
2139 if self.returned_newline: # skip
2140 return None
2141
2142 return self.cur_token
2143
2144 elif self.token_kind == Kind.Right:
2145 if self.token_type not in (Id.Right_Subshell, Id.Right_ShFunction,
2146 Id.Right_CasePat, Id.Right_Initializer):
2147 raise AssertionError(self.cur_token)
2148
2149 self._SetNext(lex_mode)
2150 return self.cur_token
2151
2152 elif self.token_kind in (Kind.Ignored, Kind.WS):
2153 self._SetNext(lex_mode)
2154 return None
2155
2156 else:
2157 assert self.token_kind in (Kind.VSub, Kind.Lit, Kind.History,
2158 Kind.Left, Kind.KW, Kind.ControlFlow,
2159 Kind.BoolUnary, Kind.BoolBinary,
2160 Kind.ExtGlob,
2161 Kind.BashRegex), 'Unhandled token kind'
2162
2163 if (word_mode == lex_mode_e.ShCommandFakeBrack and
2164 self.parse_opts.parse_bracket() and
2165 self.token_type == Id.Lit_LBracket):
2166 # Change [ from Kind.Lit -> Kind.Op
2167 # So CommandParser can treat
2168 # assert [42 === x]
2169 # like
2170 # json write (x)
2171 bracket_word = self.cur_token
2172 bracket_word.id = Id.Op_LBracket
2173
2174 self._SetNext(lex_mode)
2175 return bracket_word
2176
2177 # We're beginning a word. If we see Id.Lit_Pound, change to
2178 # lex_mode_e.Comment and read until end of line.
2179 if self.token_type == Id.Lit_Pound:
2180 self._SetNext(lex_mode_e.Comment)
2181 self._GetToken()
2182
2183 # NOTE: The # could be the last character in the file. It can't be
2184 # Eof_{RParen,Backtick} because #) and #` are comments.
2185 assert self.token_type in (Id.Ignored_Comment, Id.Eof_Real), \
2186 self.cur_token
2187
2188 # The next iteration will go into Kind.Ignored and set lex state to
2189 # lex_mode_e.ShCommand/etc.
2190 return None # tell ReadWord() to try again after comment
2191
2192 elif self.token_type == Id.Lit_TPound: ### doc comment
2193 self._SetNext(lex_mode_e.Comment)
2194 self._GetToken()
2195
2196 if self.token_type == Id.Ignored_Comment and self.emit_doc_token:
2197 return self.cur_token
2198
2199 return None # tell ReadWord() to try again after comment
2200
2201 else:
2202 # r'' u'' b'' at the beginning of a word
2203 if (self.token_type == Id.Lit_Chars and
2204 self.lexer.LookAheadOne(
2205 lex_mode_e.ShCommand) == Id.Left_SingleQuote):
2206
2207 # When shopt -s parse_ysh_string:
2208 # echo r'hi' is like echo 'hi'
2209 #
2210 # echo u'\u{3bc}' b'\yff' works
2211
2212 tok = self.cur_token
2213 if self.parse_opts.parse_ysh_string():
2214 if lexer.TokenEquals(tok, 'r'):
2215 left_id = Id.Left_RSingleQuote
2216 elif lexer.TokenEquals(tok, 'u'):
2217 left_id = Id.Left_USingleQuote
2218 elif lexer.TokenEquals(tok, 'b'):
2219 left_id = Id.Left_BSingleQuote
2220 else:
2221 left_id = Id.Undefined_Tok
2222
2223 if left_id != Id.Undefined_Tok:
2224 # skip the r, and then 'foo' will be read as normal
2225 self._SetNext(lex_mode_e.ShCommand)
2226
2227 self._GetToken()
2228 assert self.token_type == Id.Left_SingleQuote, self.token_type
2229
2230 # Read the word in a different lexer mode
2231 return self._ReadYshSingleQuoted(left_id)
2232
2233 return self._ReadCompoundOrRedir(lex_mode)
2234
2235 def ParseVarRef(self):
2236 # type: () -> BracedVarSub
2237 """DYNAMIC parsing of what's inside ${!ref}
2238
2239 # Same as VarOf production
2240 VarRefExpr = VarOf EOF
2241 """
2242 self._SetNext(lex_mode_e.VSub_1)
2243
2244 self._GetToken()
2245 if self.token_kind != Kind.VSub:
2246 p_die('Expected var name', self.cur_token)
2247
2248 part = self._ParseVarOf()
2249 # NOTE: no ${ } means no part.left and part.right
2250 part.left = part.name_tok # cheat to make test pass
2251 part.right = part.name_tok
2252
2253 self._GetToken()
2254 if self.token_type != Id.Eof_Real:
2255 p_die('Expected end of var ref expression', self.cur_token)
2256 return part
2257
2258 def LookPastSpace(self):
2259 # type: () -> Id_t
2260 """Look ahead to the next token.
2261
2262 For the CommandParser to recognize
2263 array= (1 2 3)
2264 YSH for ( versus bash for ((
2265 YSH if ( versus if test
2266 YSH while ( versus while test
2267 YSH bare assignment 'grep =' versus 'grep foo'
2268 """
2269 assert self.token_type != Id.Undefined_Tok
2270 if self.cur_token.id == Id.WS_Space:
2271 id_ = self.lexer.LookPastSpace(lex_mode_e.ShCommand)
2272 else:
2273 id_ = self.cur_token.id
2274 return id_
2275
2276 def LookAheadDParens(self, shift_back=0):
2277 # type: (int) -> bool
2278 """Special lookahead for (( )), to make sure it's an arithmetic
2279 expression (i.e. that the closing parens are a single token, not
2280 separated by anything).
2281 """
2282 assert self.token_type in (Id.Op_DLeftParen, Id.Left_DollarDParen)
2283
2284 return self.lexer.LookAheadDParens(shift_back)
2285
2286 def LookAheadFuncParens(self):
2287 # type: () -> bool
2288 """Special lookahead for f( ) { echo hi; } to check for ( )"""
2289 assert self.token_type != Id.Undefined_Tok
2290
2291 # We have to handle 2 cases because we buffer a token
2292 if self.cur_token.id == Id.Op_LParen: # saw funcname(
2293 return self.lexer.LookAheadFuncParens(1) # go back one char
2294
2295 elif self.cur_token.id == Id.WS_Space: # saw funcname WHITESPACE
2296 return self.lexer.LookAheadFuncParens(0)
2297
2298 else:
2299 return False
2300
2301 def ReadWord(self, word_mode):
2302 # type: (lex_mode_t) -> word_t
2303 """Read the next word, using the given lexer mode.
2304
2305 This is a stateful wrapper for the stateless _ReadWord function.
2306 """
2307 assert word_mode in (lex_mode_e.ShCommand,
2308 lex_mode_e.ShCommandFakeBrack,
2309 lex_mode_e.DBracket, lex_mode_e.BashRegex)
2310
2311 if self.buffered_word: # For integration with pgen2
2312 w = self.buffered_word
2313 self.buffered_word = None
2314 else:
2315 while True:
2316 w = self._ReadWord(word_mode)
2317 if w is not None:
2318 break
2319
2320 self.returned_newline = (word_.CommandId(w) == Id.Op_Newline)
2321 return w
2322
2323 def ReadArithWord(self):
2324 # type: () -> word_t
2325 while True:
2326 w = self._ReadArithWord()
2327 if w is not None:
2328 break
2329 return w
2330
2331 def ReadHereDocBody(self, parts):
2332 # type: (List[word_part_t]) -> None
2333 """
2334 A here doc is like a double quoted context, except " isn't special.
2335 """
2336 self._ReadLikeDQ(None, False, parts)
2337 # Returns nothing
2338
2339 def ReadForPlugin(self):
2340 # type: () -> CompoundWord
2341 """For $PS1, $PS4, etc.
2342
2343 This is just like reading a here doc line. "\n" is allowed, as
2344 well as the typical substitutions ${x} $(echo hi) $((1 + 2)).
2345 """
2346 w = CompoundWord([])
2347 self._ReadLikeDQ(None, False, w.parts)
2348 return w
2349
2350 def EmitDocToken(self, b):
2351 # type: (bool) -> None
2352 self.emit_doc_token = b
2353
2354 def Multiline(self, b):
2355 # type: (bool) -> None
2356 self.multiline = b
2357
2358
2359if 0:
2360 import collections
2361 WORD_HIST = collections.Counter()
2362
2363# vim: sw=4