OILS / osh / sh_expr_eval.py View on Github | oilshell.org

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1#!/usr/bin/env python2
2# Copyright 2016 Andy Chu. All rights reserved.
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7# http://www.apache.org/licenses/LICENSE-2.0
8"""
9sh_expr_eval.py -- Shell boolean and arithmetic expressions.
10"""
11from __future__ import print_function
12
13from _devbuild.gen.id_kind_asdl import Id
14from _devbuild.gen.runtime_asdl import scope_t
15from _devbuild.gen.syntax_asdl import (
16 word_t,
17 CompoundWord,
18 Token,
19 loc,
20 loc_t,
21 source,
22 arith_expr,
23 arith_expr_e,
24 arith_expr_t,
25 bool_expr,
26 bool_expr_e,
27 bool_expr_t,
28 sh_lhs,
29 sh_lhs_e,
30 sh_lhs_t,
31 BracedVarSub,
32)
33from _devbuild.gen.option_asdl import option_i
34from _devbuild.gen.types_asdl import bool_arg_type_e
35from _devbuild.gen.value_asdl import (
36 value,
37 value_e,
38 value_t,
39 sh_lvalue,
40 sh_lvalue_e,
41 sh_lvalue_t,
42 LeftName,
43 eggex_ops,
44 regex_match,
45 RegexMatch,
46)
47from core import alloc
48from core import error
49from core.error import e_die, e_die_status, e_strict, e_usage
50from core import num
51from core import state
52from core import ui
53from frontend import consts
54from frontend import lexer
55from frontend import location
56from frontend import match
57from frontend import parse_lib
58from frontend import reader
59from mycpp import mops
60from mycpp import mylib
61from mycpp.mylib import log, tagswitch, switch, str_cmp
62from osh import bool_stat
63from osh import word_eval
64
65import libc # for fnmatch
66# Import these names directly because the C++ translation uses macros literally.
67from libc import FNM_CASEFOLD, REG_ICASE
68
69from typing import Tuple, Optional, cast, TYPE_CHECKING
70if TYPE_CHECKING:
71 from core.ui import ErrorFormatter
72 from core import optview
73
74_ = log
75
76#
77# Arith and Command/Word variants of assignment
78#
79# Calls EvalShellLhs()
80# a[$key]=$val # osh/cmd_eval.py:814 (command_e.ShAssignment)
81# Calls EvalArithLhs()
82# (( a[key] = val )) # osh/sh_expr_eval.py:326 (_EvalLhsArith)
83#
84# Calls OldValue()
85# a[$key]+=$val # osh/cmd_eval.py:795 (assign_op_e.PlusEqual)
86# (( a[key] += val )) # osh/sh_expr_eval.py:308 (_EvalLhsAndLookupArith)
87#
88# RHS Indexing
89# val=${a[$key]} # osh/word_eval.py:639 (bracket_op_e.ArrayIndex)
90# (( val = a[key] )) # osh/sh_expr_eval.py:509 (Id.Arith_LBracket)
91#
92
93
94def OldValue(lval, mem, exec_opts):
95 # type: (sh_lvalue_t, state.Mem, Optional[optview.Exec]) -> value_t
96 """Look up for augmented assignment.
97
98 For s+=val and (( i += 1 ))
99
100 Args:
101 lval: value we need to
102 exec_opts: can be None if we don't want to check set -u!
103 Because s+=val doesn't check it.
104
105 TODO: A stricter and less ambiguous version for YSH.
106 - Problem: why does sh_lvalue have Indexed and Keyed, while sh_lhs only has
107 IndexedName?
108 - should I have location.LName and sh_lvalue.Indexed only?
109 - and Indexed uses the index_t type?
110 - well that might be Str or Int
111 """
112 assert isinstance(lval, sh_lvalue_t), lval
113
114 # TODO: refactor sh_lvalue_t to make this simpler
115 UP_lval = lval
116 with tagswitch(lval) as case:
117 if case(sh_lvalue_e.Var): # (( i++ ))
118 lval = cast(LeftName, UP_lval)
119 var_name = lval.name
120 elif case(sh_lvalue_e.Indexed): # (( a[i]++ ))
121 lval = cast(sh_lvalue.Indexed, UP_lval)
122 var_name = lval.name
123 elif case(sh_lvalue_e.Keyed): # (( A['K']++ )) ? I think this works
124 lval = cast(sh_lvalue.Keyed, UP_lval)
125 var_name = lval.name
126 else:
127 raise AssertionError()
128
129 val = mem.GetValue(var_name)
130 if exec_opts and exec_opts.nounset() and val.tag() == value_e.Undef:
131 e_die('Undefined variable %r' % var_name) # TODO: location info
132
133 UP_val = val
134 with tagswitch(lval) as case:
135 if case(sh_lvalue_e.Var):
136 return val
137
138 elif case(sh_lvalue_e.Indexed):
139 lval = cast(sh_lvalue.Indexed, UP_lval)
140
141 array_val = None # type: value.BashArray
142 with tagswitch(val) as case2:
143 if case2(value_e.Undef):
144 array_val = value.BashArray([])
145 elif case2(value_e.BashArray):
146 tmp = cast(value.BashArray, UP_val)
147 # mycpp rewrite: add tmp. cast() creates a new var in inner scope
148 array_val = tmp
149 else:
150 e_die("Can't use [] on value of type %s" % ui.ValType(val))
151
152 s = word_eval.GetArrayItem(array_val.strs, lval.index)
153
154 if s is None:
155 val = value.Str('') # NOTE: Other logic is value.Undef? 0?
156 else:
157 assert isinstance(s, str), s
158 val = value.Str(s)
159
160 elif case(sh_lvalue_e.Keyed):
161 lval = cast(sh_lvalue.Keyed, UP_lval)
162
163 assoc_val = None # type: value.BashAssoc
164 with tagswitch(val) as case2:
165 if case2(value_e.Undef):
166 # This never happens, because undef[x]+= is assumed to
167 raise AssertionError()
168 elif case2(value_e.BashAssoc):
169 tmp2 = cast(value.BashAssoc, UP_val)
170 # mycpp rewrite: add tmp. cast() creates a new var in inner scope
171 assoc_val = tmp2
172 else:
173 e_die("Can't use [] on value of type %s" % ui.ValType(val))
174
175 s = assoc_val.d.get(lval.key)
176 if s is None:
177 val = value.Str('')
178 else:
179 val = value.Str(s)
180
181 else:
182 raise AssertionError()
183
184 return val
185
186
187# TODO: Should refactor for int/char-based processing
188if mylib.PYTHON:
189
190 def IsLower(ch):
191 # type: (str) -> bool
192 return 'a' <= ch and ch <= 'z'
193
194 def IsUpper(ch):
195 # type: (str) -> bool
196 return 'A' <= ch and ch <= 'Z'
197
198
199class UnsafeArith(object):
200 """For parsing a[i] at RUNTIME."""
201
202 def __init__(
203 self,
204 mem, # type: state.Mem
205 exec_opts, # type: optview.Exec
206 mutable_opts, # type: state.MutableOpts
207 parse_ctx, # type: parse_lib.ParseContext
208 arith_ev, # type: ArithEvaluator
209 errfmt, # type: ui.ErrorFormatter
210 ):
211 # type: (...) -> None
212 self.mem = mem
213 self.exec_opts = exec_opts
214 self.mutable_opts = mutable_opts
215 self.parse_ctx = parse_ctx
216 self.arith_ev = arith_ev
217 self.errfmt = errfmt
218
219 self.arena = self.parse_ctx.arena
220
221 def ParseLValue(self, s, location):
222 # type: (str, loc_t) -> sh_lvalue_t
223 """Parse sh_lvalue for 'unset' and 'printf -v'.
224
225 It uses the arith parser, so it behaves like the LHS of (( a[i] = x ))
226 """
227 if not self.parse_ctx.parse_opts.parse_sh_arith():
228 # Do something simpler for YSH
229 if not match.IsValidVarName(s):
230 e_die('Invalid variable name %r (parse_sh_arith is off)' % s,
231 location)
232 return LeftName(s, location)
233
234 a_parser = self.parse_ctx.MakeArithParser(s)
235
236 with alloc.ctx_SourceCode(self.arena,
237 source.ArgvWord('dynamic LHS', location)):
238 try:
239 anode = a_parser.Parse()
240 except error.Parse as e:
241 self.errfmt.PrettyPrintError(e)
242 # Exception for builtins 'unset' and 'printf'
243 e_usage('got invalid LHS expression', location)
244
245 # Note: we parse '1+2', and then it becomes a runtime error because
246 # it's not a valid LHS. Could be a parse error.
247
248 if self.exec_opts.eval_unsafe_arith():
249 lval = self.arith_ev.EvalArithLhs(anode)
250 else:
251 # Prevent attacks like these by default:
252 #
253 # unset -v 'A["$(echo K; rm *)"]'
254 with state.ctx_Option(self.mutable_opts,
255 [option_i._allow_command_sub], False):
256 lval = self.arith_ev.EvalArithLhs(anode)
257
258 return lval
259
260 def ParseVarRef(self, ref_str, blame_tok):
261 # type: (str, Token) -> BracedVarSub
262 """Parse and evaluate value for ${!ref}
263
264 This supports:
265 - 0 to 9 for $0 to $9
266 - @ for "$@" etc.
267
268 See grammar in osh/word_parse.py, which is related to grammar in
269 osh/word_parse.py _ReadBracedVarSub
270
271 Note: declare -n allows 'varname' and 'varname[i]' and 'varname[@]', but it
272 does NOT allow 0 to 9, @, *
273
274 NamerefExpr = NAME Subscript? # this allows @ and * too
275
276 _ResolveNameOrRef currently gives you a 'cell'. So it might not support
277 sh_lvalue.Indexed?
278 """
279 line_reader = reader.StringLineReader(ref_str, self.arena)
280 lexer = self.parse_ctx.MakeLexer(line_reader)
281 w_parser = self.parse_ctx.MakeWordParser(lexer, line_reader)
282
283 src = source.VarRef(blame_tok)
284 with alloc.ctx_SourceCode(self.arena, src):
285 try:
286 bvs_part = w_parser.ParseVarRef()
287 except error.Parse as e:
288 # This prints the inner location
289 self.errfmt.PrettyPrintError(e)
290
291 # this affects builtins 'unset' and 'printf'
292 e_die("Invalid var ref expression", blame_tok)
293
294 return bvs_part
295
296
297class ArithEvaluator(object):
298 """Shared between arith and bool evaluators.
299
300 They both:
301
302 1. Convert strings to integers, respecting shopt -s strict_arith.
303 2. Look up variables and evaluate words.
304 """
305
306 def __init__(
307 self,
308 mem, # type: state.Mem
309 exec_opts, # type: optview.Exec
310 mutable_opts, # type: state.MutableOpts
311 parse_ctx, # type: Optional[parse_lib.ParseContext]
312 errfmt, # type: ErrorFormatter
313 ):
314 # type: (...) -> None
315 self.word_ev = None # type: word_eval.StringWordEvaluator
316 self.mem = mem
317 self.exec_opts = exec_opts
318 self.mutable_opts = mutable_opts
319 self.parse_ctx = parse_ctx
320 self.errfmt = errfmt
321
322 def CheckCircularDeps(self):
323 # type: () -> None
324 assert self.word_ev is not None
325
326 def _StringToBigInt(self, s, blame_loc):
327 # type: (str, loc_t) -> mops.BigInt
328 """Use bash-like rules to coerce a string to an integer.
329
330 Runtime parsing enables silly stuff like $(( $(echo 1)$(echo 2) + 1 )) => 13
331
332 0xAB -- hex constant
333 042 -- octal constant
334 42 -- decimal constant
335 64#z -- arbitrary base constant
336
337 bare word: variable
338 quoted word: string (not done?)
339 """
340 if s.startswith('0x'):
341 try:
342 integer = mops.FromStr(s, 16)
343 except ValueError:
344 e_strict('Invalid hex constant %r' % s, blame_loc)
345 # TODO: don't truncate
346 return integer
347
348 if s.startswith('0'):
349 try:
350 integer = mops.FromStr(s, 8)
351 except ValueError:
352 e_strict('Invalid octal constant %r' % s, blame_loc)
353 return integer
354
355 b, digits = mylib.split_once(s, '#') # see if it has #
356 if digits is not None:
357 try:
358 base = int(b) # machine integer, not BigInt
359 except ValueError:
360 e_strict('Invalid base for numeric constant %r' % b, blame_loc)
361
362 integer = mops.ZERO
363 for ch in digits:
364 if IsLower(ch):
365 digit = ord(ch) - ord('a') + 10
366 elif IsUpper(ch):
367 digit = ord(ch) - ord('A') + 36
368 elif ch == '@': # horrible syntax
369 digit = 62
370 elif ch == '_':
371 digit = 63
372 elif ch.isdigit():
373 digit = int(ch)
374 else:
375 e_strict('Invalid digits for numeric constant %r' % digits,
376 blame_loc)
377
378 if digit >= base:
379 e_strict(
380 'Digits %r out of range for base %d' % (digits, base),
381 blame_loc)
382
383 #integer = integer * base + digit
384 integer = mops.Add(mops.Mul(integer, mops.BigInt(base)),
385 mops.BigInt(digit))
386 return integer
387
388 try:
389 # Normal base 10 integer. This includes negative numbers like '-42'.
390 integer = mops.FromStr(s)
391 except ValueError:
392 # doesn't look like an integer
393
394 # note: 'test' and '[' never evaluate recursively
395 if self.parse_ctx:
396 arena = self.parse_ctx.arena
397
398 # Special case so we don't get EOF error
399 if len(s.strip()) == 0:
400 return mops.ZERO
401
402 # For compatibility: Try to parse it as an expression and evaluate it.
403 a_parser = self.parse_ctx.MakeArithParser(s)
404
405 # TODO: Fill in the variable name
406 with alloc.ctx_SourceCode(arena,
407 source.Variable(None, blame_loc)):
408 try:
409 node2 = a_parser.Parse() # may raise error.Parse
410 except error.Parse as e:
411 self.errfmt.PrettyPrintError(e)
412 e_die('Parse error in recursive arithmetic',
413 e.location)
414
415 # Prevent infinite recursion of $(( 1x )) -- it's a word that evaluates
416 # to itself, and you don't want to reparse it as a word.
417 if node2.tag() == arith_expr_e.Word:
418 e_die("Invalid integer constant %r" % s, blame_loc)
419
420 if self.exec_opts.eval_unsafe_arith():
421 integer = self.EvalToBigInt(node2)
422 else:
423 # BoolEvaluator doesn't have parse_ctx or mutable_opts
424 assert self.mutable_opts is not None
425
426 # We don't need to flip _allow_process_sub, because they can't be
427 # parsed. See spec/bugs.test.sh.
428 with state.ctx_Option(self.mutable_opts,
429 [option_i._allow_command_sub],
430 False):
431 integer = self.EvalToBigInt(node2)
432
433 else:
434 if len(s.strip()) == 0 or match.IsValidVarName(s):
435 # x42 could evaluate to 0
436 e_strict("Invalid integer constant %r" % s, blame_loc)
437 else:
438 # 42x is always fatal!
439 e_die("Invalid integer constant %r" % s, blame_loc)
440
441 return integer
442
443 def _ValToIntOrError(self, val, blame):
444 # type: (value_t, arith_expr_t) -> mops.BigInt
445 try:
446 UP_val = val
447 with tagswitch(val) as case:
448 if case(value_e.Undef):
449 # 'nounset' already handled before got here
450 # Happens upon a[undefined]=42, which unfortunately turns into a[0]=42.
451 e_strict('Undefined value in arithmetic context',
452 loc.Arith(blame))
453
454 elif case(value_e.Int):
455 val = cast(value.Int, UP_val)
456 return val.i
457
458 elif case(value_e.Str):
459 val = cast(value.Str, UP_val)
460 # calls e_strict
461 return self._StringToBigInt(val.s, loc.Arith(blame))
462
463 except error.Strict as e:
464 if self.exec_opts.strict_arith():
465 raise
466 else:
467 return mops.ZERO
468
469 # Arrays and associative arrays always fail -- not controlled by
470 # strict_arith.
471 # In bash, (( a )) is like (( a[0] )), but I don't want that.
472 # And returning '0' gives different results.
473 e_die(
474 "Expected a value convertible to integer, got %s" %
475 ui.ValType(val), loc.Arith(blame))
476
477 def _EvalLhsAndLookupArith(self, node):
478 # type: (arith_expr_t) -> Tuple[mops.BigInt, sh_lvalue_t]
479 """ For x = y and x += y and ++x """
480
481 lval = self.EvalArithLhs(node)
482 val = OldValue(lval, self.mem, self.exec_opts)
483
484 # BASH_LINENO, arr (array name without strict_array), etc.
485 if (val.tag() in (value_e.BashArray, value_e.BashAssoc) and
486 lval.tag() == sh_lvalue_e.Var):
487 named_lval = cast(LeftName, lval)
488 if word_eval.ShouldArrayDecay(named_lval.name, self.exec_opts):
489 if val.tag() == value_e.BashArray:
490 lval = sh_lvalue.Indexed(named_lval.name, 0, loc.Missing)
491 elif val.tag() == value_e.BashAssoc:
492 lval = sh_lvalue.Keyed(named_lval.name, '0', loc.Missing)
493 val = word_eval.DecayArray(val)
494
495 # This error message could be better, but we already have one
496 #if val.tag() == value_e.BashArray:
497 # e_die("Can't use assignment like ++ or += on arrays")
498
499 i = self._ValToIntOrError(val, node)
500 return i, lval
501
502 def _Store(self, lval, new_int):
503 # type: (sh_lvalue_t, mops.BigInt) -> None
504 val = value.Str(mops.ToStr(new_int))
505 state.OshLanguageSetValue(self.mem, lval, val)
506
507 def EvalToBigInt(self, node):
508 # type: (arith_expr_t) -> mops.BigInt
509 """Used externally by ${a[i+1]} and ${a:start:len}.
510
511 Also used internally.
512 """
513 val = self.Eval(node)
514
515 # BASH_LINENO, arr (array name without strict_array), etc.
516 if (val.tag() in (value_e.BashArray, value_e.BashAssoc) and
517 node.tag() == arith_expr_e.VarSub):
518 vsub = cast(Token, node)
519 if word_eval.ShouldArrayDecay(lexer.LazyStr(vsub), self.exec_opts):
520 val = word_eval.DecayArray(val)
521
522 i = self._ValToIntOrError(val, node)
523 return i
524
525 def EvalToInt(self, node):
526 # type: (arith_expr_t) -> int
527 return mops.BigTruncate(self.EvalToBigInt(node))
528
529 def Eval(self, node):
530 # type: (arith_expr_t) -> value_t
531 """
532 Returns:
533 None for Undef (e.g. empty cell) TODO: Don't return 0!
534 int for Str
535 List[int] for BashArray
536 Dict[str, str] for BashAssoc (TODO: Should we support this?)
537
538 NOTE: (( A['x'] = 'x' )) and (( x = A['x'] )) are syntactically valid in
539 bash, but don't do what you'd think. 'x' sometimes a variable name and
540 sometimes a key.
541 """
542 # OSH semantics: Variable NAMES cannot be formed dynamically; but INTEGERS
543 # can. ${foo:-3}4 is OK. $? will be a compound word too, so we don't have
544 # to handle that as a special case.
545
546 UP_node = node
547 with tagswitch(node) as case:
548 if case(arith_expr_e.EmptyZero): # $(( ))
549 return value.Int(mops.ZERO) # Weird axiom
550
551 elif case(arith_expr_e.EmptyOne): # for (( ; ; ))
552 return value.Int(mops.ONE)
553
554 elif case(arith_expr_e.VarSub): # $(( x )) (can be array)
555 vsub = cast(Token, UP_node)
556 var_name = lexer.LazyStr(vsub)
557 val = self.mem.GetValue(var_name)
558 if val.tag() == value_e.Undef and self.exec_opts.nounset():
559 e_die('Undefined variable %r' % var_name, vsub)
560 return val
561
562 elif case(arith_expr_e.Word): # $(( $x )) $(( ${x}${y} )), etc.
563 w = cast(CompoundWord, UP_node)
564 return self.word_ev.EvalWordToString(w)
565
566 elif case(arith_expr_e.UnaryAssign): # a++
567 node = cast(arith_expr.UnaryAssign, UP_node)
568
569 op_id = node.op_id
570 old_big, lval = self._EvalLhsAndLookupArith(node.child)
571
572 if op_id == Id.Node_PostDPlus: # post-increment
573 new_big = mops.Add(old_big, mops.ONE)
574 result = old_big
575
576 elif op_id == Id.Node_PostDMinus: # post-decrement
577 new_big = mops.Sub(old_big, mops.ONE)
578 result = old_big
579
580 elif op_id == Id.Arith_DPlus: # pre-increment
581 new_big = mops.Add(old_big, mops.ONE)
582 result = new_big
583
584 elif op_id == Id.Arith_DMinus: # pre-decrement
585 new_big = mops.Sub(old_big, mops.ONE)
586 result = new_big
587
588 else:
589 raise AssertionError(op_id)
590
591 self._Store(lval, new_big)
592 return value.Int(result)
593
594 elif case(arith_expr_e.BinaryAssign): # a=1, a+=5, a[1]+=5
595 node = cast(arith_expr.BinaryAssign, UP_node)
596 op_id = node.op_id
597
598 if op_id == Id.Arith_Equal:
599 # Don't really need a span ID here, because tdop.CheckLhsExpr should
600 # have done all the validation.
601 lval = self.EvalArithLhs(node.left)
602 rhs_big = self.EvalToBigInt(node.right)
603
604 self._Store(lval, rhs_big)
605 return value.Int(rhs_big)
606
607 old_big, lval = self._EvalLhsAndLookupArith(node.left)
608 rhs_big = self.EvalToBigInt(node.right)
609
610 if op_id == Id.Arith_PlusEqual:
611 new_big = mops.Add(old_big, rhs_big)
612 elif op_id == Id.Arith_MinusEqual:
613 new_big = mops.Sub(old_big, rhs_big)
614 elif op_id == Id.Arith_StarEqual:
615 new_big = mops.Mul(old_big, rhs_big)
616
617 elif op_id == Id.Arith_SlashEqual:
618 if mops.Equal(rhs_big, mops.ZERO):
619 e_die('Divide by zero') # TODO: location
620 new_big = num.IntDivide(old_big, rhs_big)
621
622 elif op_id == Id.Arith_PercentEqual:
623 if mops.Equal(rhs_big, mops.ZERO):
624 e_die('Divide by zero') # TODO: location
625 new_big = num.IntRemainder(old_big, rhs_big)
626
627 elif op_id == Id.Arith_DGreatEqual:
628 new_big = mops.RShift(old_big, rhs_big)
629 elif op_id == Id.Arith_DLessEqual:
630 new_big = mops.LShift(old_big, rhs_big)
631 elif op_id == Id.Arith_AmpEqual:
632 new_big = mops.BitAnd(old_big, rhs_big)
633 elif op_id == Id.Arith_PipeEqual:
634 new_big = mops.BitOr(old_big, rhs_big)
635 elif op_id == Id.Arith_CaretEqual:
636 new_big = mops.BitXor(old_big, rhs_big)
637 else:
638 raise AssertionError(op_id) # shouldn't get here
639
640 self._Store(lval, new_big)
641 return value.Int(new_big)
642
643 elif case(arith_expr_e.Unary):
644 node = cast(arith_expr.Unary, UP_node)
645 op_id = node.op_id
646
647 i = self.EvalToBigInt(node.child)
648
649 if op_id == Id.Node_UnaryPlus: # +i
650 result = i
651 elif op_id == Id.Node_UnaryMinus: # -i
652 result = mops.Sub(mops.ZERO, i)
653
654 elif op_id == Id.Arith_Bang: # logical negation
655 if mops.Equal(i, mops.ZERO):
656 result = mops.ONE
657 else:
658 result = mops.ZERO
659 elif op_id == Id.Arith_Tilde: # bitwise complement
660 result = mops.BitNot(i)
661 else:
662 raise AssertionError(op_id) # shouldn't get here
663
664 return value.Int(result)
665
666 elif case(arith_expr_e.Binary):
667 node = cast(arith_expr.Binary, UP_node)
668 op_id = node.op.id
669
670 # Short-circuit evaluation for || and &&.
671 if op_id == Id.Arith_DPipe:
672 lhs_big = self.EvalToBigInt(node.left)
673 if mops.Equal(lhs_big, mops.ZERO):
674 rhs_big = self.EvalToBigInt(node.right)
675 if mops.Equal(rhs_big, mops.ZERO):
676 result = mops.ZERO # false
677 else:
678 result = mops.ONE # true
679 else:
680 result = mops.ONE # true
681 return value.Int(result)
682
683 if op_id == Id.Arith_DAmp:
684 lhs_big = self.EvalToBigInt(node.left)
685 if mops.Equal(lhs_big, mops.ZERO):
686 result = mops.ZERO # false
687 else:
688 rhs_big = self.EvalToBigInt(node.right)
689 if mops.Equal(rhs_big, mops.ZERO):
690 result = mops.ZERO # false
691 else:
692 result = mops.ONE # true
693 return value.Int(result)
694
695 if op_id == Id.Arith_LBracket:
696 # NOTE: Similar to bracket_op_e.ArrayIndex in osh/word_eval.py
697
698 left = self.Eval(node.left)
699 UP_left = left
700 with tagswitch(left) as case:
701 if case(value_e.BashArray):
702 array_val = cast(value.BashArray, UP_left)
703 small_i = mops.BigTruncate(
704 self.EvalToBigInt(node.right))
705 s = word_eval.GetArrayItem(array_val.strs, small_i)
706
707 elif case(value_e.BashAssoc):
708 left = cast(value.BashAssoc, UP_left)
709 key = self.EvalWordToString(node.right)
710 s = left.d.get(key)
711
712 elif case(value_e.Str):
713 left = cast(value.Str, UP_left)
714 if self.exec_opts.strict_arith():
715 e_die(
716 "Value of type Str can't be indexed (strict_arith)",
717 node.op)
718 index = self.EvalToBigInt(node.right)
719 # s[0] evaluates to s
720 # s[1] evaluates to Undef
721 s = left.s if mops.Equal(index, mops.ZERO) else None
722
723 elif case(value_e.Undef):
724 if self.exec_opts.strict_arith():
725 e_die(
726 "Value of type Undef can't be indexed (strict_arith)",
727 node.op)
728 s = None # value.Undef
729
730 # There isn't a way to distinguish Undef vs. empty
731 # string, even with set -o nounset?
732 # s = ''
733
734 else:
735 # TODO: Add error context
736 e_die(
737 "Value of type %s can't be indexed" %
738 ui.ValType(left), node.op)
739
740 if s is None:
741 val = value.Undef
742 else:
743 val = value.Str(s)
744
745 return val
746
747 if op_id == Id.Arith_Comma:
748 self.EvalToBigInt(node.left) # throw away result
749 result = self.EvalToBigInt(node.right)
750 return value.Int(result)
751
752 # Rest are integers
753 lhs_big = self.EvalToBigInt(node.left)
754 rhs_big = self.EvalToBigInt(node.right)
755
756 if op_id == Id.Arith_Plus:
757 result = mops.Add(lhs_big, rhs_big)
758 elif op_id == Id.Arith_Minus:
759 result = mops.Sub(lhs_big, rhs_big)
760 elif op_id == Id.Arith_Star:
761 result = mops.Mul(lhs_big, rhs_big)
762 elif op_id == Id.Arith_Slash:
763 if mops.Equal(rhs_big, mops.ZERO):
764 e_die('Divide by zero', node.op)
765 result = num.IntDivide(lhs_big, rhs_big)
766
767 elif op_id == Id.Arith_Percent:
768 if mops.Equal(rhs_big, mops.ZERO):
769 e_die('Divide by zero', node.op)
770 result = num.IntRemainder(lhs_big, rhs_big)
771
772 elif op_id == Id.Arith_DStar:
773 if mops.Greater(mops.ZERO, rhs_big):
774 e_die("Exponent can't be a negative number",
775 loc.Arith(node.right))
776 result = num.Exponent(lhs_big, rhs_big)
777
778 elif op_id == Id.Arith_DEqual:
779 result = mops.FromBool(mops.Equal(lhs_big, rhs_big))
780 elif op_id == Id.Arith_NEqual:
781 result = mops.FromBool(not mops.Equal(lhs_big, rhs_big))
782 elif op_id == Id.Arith_Great:
783 result = mops.FromBool(mops.Greater(lhs_big, rhs_big))
784 elif op_id == Id.Arith_GreatEqual:
785 result = mops.FromBool(
786 mops.Greater(lhs_big, rhs_big) or
787 mops.Equal(lhs_big, rhs_big))
788 elif op_id == Id.Arith_Less:
789 result = mops.FromBool(mops.Greater(rhs_big, lhs_big))
790 elif op_id == Id.Arith_LessEqual:
791 result = mops.FromBool(
792 mops.Greater(rhs_big, lhs_big) or
793 mops.Equal(lhs_big, rhs_big))
794
795 elif op_id == Id.Arith_Pipe:
796 result = mops.BitOr(lhs_big, rhs_big)
797 elif op_id == Id.Arith_Amp:
798 result = mops.BitAnd(lhs_big, rhs_big)
799 elif op_id == Id.Arith_Caret:
800 result = mops.BitXor(lhs_big, rhs_big)
801
802 # Note: how to define shift of negative numbers?
803 elif op_id == Id.Arith_DLess:
804 result = mops.LShift(lhs_big, rhs_big)
805 elif op_id == Id.Arith_DGreat:
806 result = mops.RShift(lhs_big, rhs_big)
807 else:
808 raise AssertionError(op_id)
809
810 return value.Int(result)
811
812 elif case(arith_expr_e.TernaryOp):
813 node = cast(arith_expr.TernaryOp, UP_node)
814
815 cond = self.EvalToBigInt(node.cond)
816 if mops.Equal(cond, mops.ZERO):
817 return self.Eval(node.false_expr)
818 else:
819 return self.Eval(node.true_expr)
820
821 else:
822 raise AssertionError(node.tag())
823
824 raise AssertionError('for -Wreturn-type in C++')
825
826 def EvalWordToString(self, node, blame_loc=loc.Missing):
827 # type: (arith_expr_t, loc_t) -> str
828 """
829 Raises:
830 error.FatalRuntime if the expression isn't a string
831 or if it contains a bare variable like a[x]
832
833 These are allowed because they're unambiguous, unlike a[x]
834
835 a[$x] a["$x"] a["x"] a['x']
836 """
837 UP_node = node
838 if node.tag() == arith_expr_e.Word: # $(( $x )) $(( ${x}${y} )), etc.
839 w = cast(CompoundWord, UP_node)
840 val = self.word_ev.EvalWordToString(w)
841 return val.s
842 else:
843 # A[x] is the "Parsing Bash is Undecidable" problem
844 # It is a string or var name?
845 # (It's parsed as arith_expr.VarSub)
846 e_die(
847 "Assoc array keys must be strings: $x 'x' \"$x\" etc. (OILS-ERR-101)",
848 blame_loc)
849
850 def EvalShellLhs(self, node, which_scopes):
851 # type: (sh_lhs_t, scope_t) -> sh_lvalue_t
852 """Evaluate a shell LHS expression
853
854 For a=b and a[x]=b etc.
855 """
856 assert isinstance(node, sh_lhs_t), node
857
858 UP_node = node
859 lval = None # type: sh_lvalue_t
860 with tagswitch(node) as case:
861 if case(sh_lhs_e.Name): # a=x
862 node = cast(sh_lhs.Name, UP_node)
863 assert node.name is not None
864
865 lval1 = LeftName(node.name, node.left)
866 lval = lval1
867
868 elif case(sh_lhs_e.IndexedName): # a[1+2]=x
869 node = cast(sh_lhs.IndexedName, UP_node)
870 assert node.name is not None
871
872 if self.mem.IsBashAssoc(node.name):
873 key = self.EvalWordToString(node.index,
874 blame_loc=node.left)
875 # node.left points to A[ in A[x]=1
876 lval2 = sh_lvalue.Keyed(node.name, key, node.left)
877 lval = lval2
878 else:
879 index = mops.BigTruncate(self.EvalToBigInt(node.index))
880 lval3 = sh_lvalue.Indexed(node.name, index, node.left)
881 lval = lval3
882
883 else:
884 raise AssertionError(node.tag())
885
886 return lval
887
888 def _VarNameOrWord(self, anode):
889 # type: (arith_expr_t) -> Tuple[Optional[str], loc_t]
890 """
891 Returns a variable name if the arith node can be interpreted that way.
892 """
893 UP_anode = anode
894 with tagswitch(anode) as case:
895 if case(arith_expr_e.VarSub):
896 tok = cast(Token, UP_anode)
897 return (lexer.LazyStr(tok), tok)
898
899 elif case(arith_expr_e.Word):
900 w = cast(CompoundWord, UP_anode)
901 var_name = self.EvalWordToString(w)
902 return (var_name, w)
903
904 no_str = None # type: str
905 return (no_str, loc.Missing)
906
907 def EvalArithLhs(self, anode):
908 # type: (arith_expr_t) -> sh_lvalue_t
909 """
910 For (( a[x] = 1 )) etc.
911 """
912 UP_anode = anode
913 if anode.tag() == arith_expr_e.Binary:
914 anode = cast(arith_expr.Binary, UP_anode)
915 if anode.op.id == Id.Arith_LBracket:
916 var_name, blame_loc = self._VarNameOrWord(anode.left)
917
918 # (( 1[2] = 3 )) isn't valid
919 if not match.IsValidVarName(var_name):
920 e_die('Invalid variable name %r' % var_name, blame_loc)
921
922 if var_name is not None:
923 if self.mem.IsBashAssoc(var_name):
924 arith_loc = location.TokenForArith(anode)
925 key = self.EvalWordToString(anode.right,
926 blame_loc=arith_loc)
927 return sh_lvalue.Keyed(var_name, key, blame_loc)
928 else:
929 index = mops.BigTruncate(self.EvalToBigInt(
930 anode.right))
931 return sh_lvalue.Indexed(var_name, index, blame_loc)
932
933 var_name, blame_loc = self._VarNameOrWord(anode)
934 if var_name is not None:
935 return LeftName(var_name, blame_loc)
936
937 # e.g. unset 'x-y'. status 2 for runtime parse error
938 e_die_status(2, 'Invalid LHS to modify', blame_loc)
939
940
941class BoolEvaluator(ArithEvaluator):
942 """This is also an ArithEvaluator because it has to understand.
943
944 [[ x -eq 3 ]]
945
946 where x='1+2'
947 """
948
949 def __init__(
950 self,
951 mem, # type: state.Mem
952 exec_opts, # type: optview.Exec
953 mutable_opts, # type: Optional[state.MutableOpts]
954 parse_ctx, # type: Optional[parse_lib.ParseContext]
955 errfmt, # type: ErrorFormatter
956 always_strict=False # type: bool
957 ):
958 # type: (...) -> None
959 ArithEvaluator.__init__(self, mem, exec_opts, mutable_opts, parse_ctx,
960 errfmt)
961 self.always_strict = always_strict
962
963 def _StringToBigIntOrError(self, s, blame_word=None):
964 # type: (str, Optional[word_t]) -> mops.BigInt
965 """Used by both [[ $x -gt 3 ]] and (( $x ))."""
966 if blame_word:
967 location = loc.Word(blame_word) # type: loc_t
968 else:
969 location = loc.Missing
970
971 try:
972 i = self._StringToBigInt(s, location)
973 except error.Strict as e:
974 if self.always_strict or self.exec_opts.strict_arith():
975 raise
976 else:
977 i = mops.ZERO
978 return i
979
980 def _EvalCompoundWord(self, word, eval_flags=0):
981 # type: (word_t, int) -> str
982 val = self.word_ev.EvalWordToString(word, eval_flags)
983 return val.s
984
985 def EvalB(self, node):
986 # type: (bool_expr_t) -> bool
987
988 UP_node = node
989 with tagswitch(node) as case:
990 if case(bool_expr_e.WordTest):
991 node = cast(bool_expr.WordTest, UP_node)
992 s = self._EvalCompoundWord(node.w)
993 return bool(s)
994
995 elif case(bool_expr_e.LogicalNot):
996 node = cast(bool_expr.LogicalNot, UP_node)
997 b = self.EvalB(node.child)
998 return not b
999
1000 elif case(bool_expr_e.LogicalAnd):
1001 node = cast(bool_expr.LogicalAnd, UP_node)
1002 # Short-circuit evaluation
1003 if self.EvalB(node.left):
1004 return self.EvalB(node.right)
1005 else:
1006 return False
1007
1008 elif case(bool_expr_e.LogicalOr):
1009 node = cast(bool_expr.LogicalOr, UP_node)
1010 if self.EvalB(node.left):
1011 return True
1012 else:
1013 return self.EvalB(node.right)
1014
1015 elif case(bool_expr_e.Unary):
1016 node = cast(bool_expr.Unary, UP_node)
1017 op_id = node.op_id
1018 s = self._EvalCompoundWord(node.child)
1019
1020 # Now dispatch on arg type
1021 arg_type = consts.BoolArgType(
1022 op_id) # could be static in the LST?
1023
1024 if arg_type == bool_arg_type_e.Path:
1025 return bool_stat.DoUnaryOp(op_id, s)
1026
1027 if arg_type == bool_arg_type_e.Str:
1028 if op_id == Id.BoolUnary_z:
1029 return not bool(s)
1030 if op_id == Id.BoolUnary_n:
1031 return bool(s)
1032
1033 raise AssertionError(op_id) # should never happen
1034
1035 if arg_type == bool_arg_type_e.Other:
1036 if op_id == Id.BoolUnary_t:
1037 return bool_stat.isatty(s, node.child)
1038
1039 # See whether 'set -o' options have been set
1040 if op_id == Id.BoolUnary_o:
1041 index = consts.OptionNum(s)
1042 if index == 0:
1043 return False
1044 else:
1045 return self.exec_opts.opt0_array[index]
1046
1047 if op_id == Id.BoolUnary_v:
1048 val = self.mem.GetValue(s)
1049 return val.tag() != value_e.Undef
1050
1051 e_die("%s isn't implemented" %
1052 ui.PrettyId(op_id)) # implicit location
1053
1054 raise AssertionError(arg_type)
1055
1056 elif case(bool_expr_e.Binary):
1057 node = cast(bool_expr.Binary, UP_node)
1058
1059 op_id = node.op_id
1060 # Whether to glob escape
1061 eval_flags = 0
1062 with switch(op_id) as case2:
1063 if case2(Id.BoolBinary_GlobEqual, Id.BoolBinary_GlobDEqual,
1064 Id.BoolBinary_GlobNEqual):
1065 eval_flags |= word_eval.QUOTE_FNMATCH
1066 elif case2(Id.BoolBinary_EqualTilde):
1067 eval_flags |= word_eval.QUOTE_ERE
1068
1069 s1 = self._EvalCompoundWord(node.left)
1070 s2 = self._EvalCompoundWord(node.right, eval_flags)
1071
1072 # Now dispatch on arg type
1073 arg_type = consts.BoolArgType(op_id)
1074
1075 if arg_type == bool_arg_type_e.Path:
1076 return bool_stat.DoBinaryOp(op_id, s1, s2)
1077
1078 if arg_type == bool_arg_type_e.Int:
1079 # NOTE: We assume they are constants like [[ 3 -eq 3 ]].
1080 # Bash also allows [[ 1+2 -eq 3 ]].
1081 i1 = self._StringToBigIntOrError(s1, blame_word=node.left)
1082 i2 = self._StringToBigIntOrError(s2, blame_word=node.right)
1083
1084 if op_id == Id.BoolBinary_eq:
1085 return mops.Equal(i1, i2)
1086 if op_id == Id.BoolBinary_ne:
1087 return not mops.Equal(i1, i2)
1088 if op_id == Id.BoolBinary_gt:
1089 return mops.Greater(i1, i2)
1090 if op_id == Id.BoolBinary_ge:
1091 return mops.Greater(i1, i2) or mops.Equal(i1, i2)
1092 if op_id == Id.BoolBinary_lt:
1093 return mops.Greater(i2, i1)
1094 if op_id == Id.BoolBinary_le:
1095 return mops.Greater(i2, i1) or mops.Equal(i1, i2)
1096
1097 raise AssertionError(op_id) # should never happen
1098
1099 if arg_type == bool_arg_type_e.Str:
1100 fnmatch_flags = (FNM_CASEFOLD
1101 if self.exec_opts.nocasematch() else 0)
1102
1103 if op_id in (Id.BoolBinary_GlobEqual,
1104 Id.BoolBinary_GlobDEqual):
1105 #log('Matching %s against pattern %s', s1, s2)
1106 return libc.fnmatch(s2, s1, fnmatch_flags)
1107
1108 if op_id == Id.BoolBinary_GlobNEqual:
1109 return not libc.fnmatch(s2, s1, fnmatch_flags)
1110
1111 if op_id in (Id.BoolBinary_Equal, Id.BoolBinary_DEqual):
1112 return s1 == s2
1113
1114 if op_id == Id.BoolBinary_NEqual:
1115 return s1 != s2
1116
1117 if op_id == Id.BoolBinary_EqualTilde:
1118 # TODO: This should go to --debug-file
1119 #log('Matching %r against regex %r', s1, s2)
1120 regex_flags = (REG_ICASE
1121 if self.exec_opts.nocasematch() else 0)
1122
1123 try:
1124 indices = libc.regex_search(s2, regex_flags, s1, 0)
1125 except ValueError as e:
1126 # Status 2 indicates a regex parse error. This is fatal in OSH but
1127 # not in bash, which treats [[ like a command with an exit code.
1128 e_die_status(2, e.message, loc.Word(node.right))
1129
1130 if indices is not None:
1131 self.mem.SetRegexMatch(
1132 RegexMatch(s1, indices, eggex_ops.No))
1133 return True
1134 else:
1135 self.mem.SetRegexMatch(regex_match.No)
1136 return False
1137
1138 if op_id == Id.Op_Less:
1139 return str_cmp(s1, s2) < 0
1140
1141 if op_id == Id.Op_Great:
1142 return str_cmp(s1, s2) > 0
1143
1144 raise AssertionError(op_id) # should never happen
1145
1146 raise AssertionError(node.tag())