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

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