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

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