| 1 | """vm.py: Library for executing shell."""
|
| 2 | from __future__ import print_function
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| 3 |
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| 4 | from _devbuild.gen.id_kind_asdl import Id, Id_t, Id_str
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| 5 | from _devbuild.gen.runtime_asdl import (CommandStatus, StatusArray, flow_e,
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| 6 | flow_t)
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| 7 | from _devbuild.gen.syntax_asdl import Token, loc, loc_t
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| 8 | from _devbuild.gen.value_asdl import value, value_e, value_t, Obj
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| 9 | from core import dev
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| 10 | from core import error
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| 11 | from core.error import e_die
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| 12 | from core import pyos
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| 13 | from core import pyutil
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| 14 | from display import ui
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| 15 | from mycpp.mylib import log, tagswitch
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| 16 |
|
| 17 | from typing import List, Dict, Tuple, Optional, Any, cast, TYPE_CHECKING
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| 18 | if TYPE_CHECKING:
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| 19 | from _devbuild.gen.runtime_asdl import cmd_value, RedirValue
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| 20 | from _devbuild.gen.syntax_asdl import (command, command_t, CommandSub)
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| 21 | from builtin import hay_ysh
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| 22 | from core import optview
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| 23 | from core import state
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| 24 | from frontend import typed_args
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| 25 | from osh import sh_expr_eval
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| 26 | from osh.sh_expr_eval import ArithEvaluator
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| 27 | from osh.sh_expr_eval import BoolEvaluator
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| 28 | from osh import word_eval
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| 29 | from osh import cmd_eval
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| 30 | from osh import prompt
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| 31 | from ysh import expr_eval
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| 32 |
|
| 33 | _ = log
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| 34 |
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| 35 |
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| 36 | class ControlFlow(Exception):
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| 37 | """Internal exception for control flow.
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| 38 |
|
| 39 | Used by CommandEvaluator and 'source' builtin
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| 40 |
|
| 41 | break and continue are caught by loops, return is caught by functions.
|
| 42 | """
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| 43 | pass
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| 44 |
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| 45 |
|
| 46 | class IntControlFlow(Exception):
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| 47 |
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| 48 | def __init__(self, keyword_id, keyword_str, keyword_loc, arg):
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| 49 | # type: (Id_t, str, loc_t, int) -> None
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| 50 | """
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| 51 | Args:
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| 52 | token: the keyword token
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| 53 | arg: exit code to 'return', or number of levels to break/continue
|
| 54 | """
|
| 55 | self.keyword_id = keyword_id
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| 56 | self.keyword_str = keyword_str
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| 57 | self.keyword_loc = keyword_loc
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| 58 | self.arg = arg
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| 59 |
|
| 60 | def Keyword(self):
|
| 61 | # type: () -> str
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| 62 | return self.keyword_str
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| 63 |
|
| 64 | def Location(self):
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| 65 | # type: () -> loc_t
|
| 66 | return self.keyword_loc
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| 67 |
|
| 68 | def IsReturn(self):
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| 69 | # type: () -> bool
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| 70 | return self.keyword_id == Id.ControlFlow_Return
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| 71 |
|
| 72 | def IsBreak(self):
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| 73 | # type: () -> bool
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| 74 | return self.keyword_id == Id.ControlFlow_Break
|
| 75 |
|
| 76 | def IsContinue(self):
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| 77 | # type: () -> bool
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| 78 | return self.keyword_id == Id.ControlFlow_Continue
|
| 79 |
|
| 80 | def StatusCode(self):
|
| 81 | # type: () -> int
|
| 82 | assert self.IsReturn()
|
| 83 | # All shells except dash do this truncation.
|
| 84 | # turn 257 into 1, and -1 into 255.
|
| 85 | return self.arg & 0xff
|
| 86 |
|
| 87 | def HandleLoop(self):
|
| 88 | # type: () -> flow_t
|
| 89 | """Mutates this exception and returns what the caller should do."""
|
| 90 |
|
| 91 | if self.IsBreak():
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| 92 | self.arg -= 1
|
| 93 | if self.arg == 0:
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| 94 | return flow_e.Break # caller should break out of loop
|
| 95 |
|
| 96 | elif self.IsContinue():
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| 97 | self.arg -= 1
|
| 98 | if self.arg == 0:
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| 99 | return flow_e.Nothing # do nothing to continue
|
| 100 |
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| 101 | # return / break 2 / continue 2 need to pop up more
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| 102 | return flow_e.Raise
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| 103 |
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| 104 | def __repr__(self):
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| 105 | # type: () -> str
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| 106 | return '<IntControlFlow %s %s>' % (Id_str(self.keyword_id), self.arg)
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| 107 |
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| 108 |
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| 109 | class ValueControlFlow(Exception):
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| 110 |
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| 111 | def __init__(self, token, value):
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| 112 | # type: (Token, value_t) -> None
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| 113 | """
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| 114 | Args:
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| 115 | token: the keyword token
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| 116 | value: value_t to 'return' from a function
|
| 117 | """
|
| 118 | self.token = token
|
| 119 | self.value = value
|
| 120 |
|
| 121 | def __repr__(self):
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| 122 | # type: () -> str
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| 123 | return '<ValueControlFlow %s %s>' % (self.token, self.value)
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| 124 |
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| 125 |
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| 126 | def InitUnsafeArith(mem, word_ev, unsafe_arith):
|
| 127 | # type: (state.Mem, word_eval.NormalWordEvaluator, sh_expr_eval.UnsafeArith) -> None
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| 128 | """Wire up circular dependencies for UnsafeArith."""
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| 129 | mem.unsafe_arith = unsafe_arith # for 'declare -n' nameref expansion of a[i]
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| 130 | word_ev.unsafe_arith = unsafe_arith # for ${!ref} expansion of a[i]
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| 131 |
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| 132 |
|
| 133 | def InitCircularDeps(
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| 134 | arith_ev, # type: ArithEvaluator
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| 135 | bool_ev, # type: BoolEvaluator
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| 136 | expr_ev, # type: expr_eval.ExprEvaluator
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| 137 | word_ev, # type: word_eval.NormalWordEvaluator
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| 138 | cmd_ev, # type: cmd_eval.CommandEvaluator
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| 139 | shell_ex, # type: _Executor
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| 140 | pure_ex, # type: _Executor
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| 141 | prompt_ev, # type: prompt.Evaluator
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| 142 | global_io, # type: Obj
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| 143 | tracer, # type: dev.Tracer
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| 144 | ):
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| 145 | # type: (...) -> None
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| 146 | """Wire up mutually recursive evaluators and runtime objects."""
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| 147 | arith_ev.word_ev = word_ev
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| 148 | bool_ev.word_ev = word_ev
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| 149 |
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| 150 | if expr_ev: # for pure OSH
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| 151 | expr_ev.shell_ex = shell_ex
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| 152 | expr_ev.cmd_ev = cmd_ev
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| 153 | expr_ev.word_ev = word_ev
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| 154 |
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| 155 | word_ev.arith_ev = arith_ev
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| 156 | word_ev.expr_ev = expr_ev
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| 157 | word_ev.prompt_ev = prompt_ev
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| 158 | word_ev.shell_ex = shell_ex
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| 159 |
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| 160 | cmd_ev.shell_ex = shell_ex
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| 161 | cmd_ev.arith_ev = arith_ev
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| 162 | cmd_ev.bool_ev = bool_ev
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| 163 | cmd_ev.expr_ev = expr_ev
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| 164 | cmd_ev.word_ev = word_ev
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| 165 | cmd_ev.tracer = tracer
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| 166 |
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| 167 | shell_ex.cmd_ev = cmd_ev
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| 168 | pure_ex.cmd_ev = cmd_ev
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| 169 |
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| 170 | prompt_ev.word_ev = word_ev
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| 171 | prompt_ev.expr_ev = expr_ev
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| 172 | prompt_ev.global_io = global_io
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| 173 |
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| 174 | tracer.word_ev = word_ev
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| 175 |
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| 176 | arith_ev.CheckCircularDeps()
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| 177 | bool_ev.CheckCircularDeps()
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| 178 | if expr_ev:
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| 179 | expr_ev.CheckCircularDeps()
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| 180 | word_ev.CheckCircularDeps()
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| 181 | cmd_ev.CheckCircularDeps()
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| 182 | shell_ex.CheckCircularDeps()
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| 183 | pure_ex.CheckCircularDeps()
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| 184 | prompt_ev.CheckCircularDeps()
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| 185 | tracer.CheckCircularDeps()
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| 186 |
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| 187 |
|
| 188 | class _Executor(object):
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| 189 |
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| 190 | def __init__(
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| 191 | self,
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| 192 | mem, # type: state.Mem
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| 193 | exec_opts, # type: optview.Exec
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| 194 | mutable_opts, # type: state.MutableOpts
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| 195 | procs, # type: state.Procs
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| 196 | hay_state, # type: hay_ysh.HayState
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| 197 | builtins, # type: Dict[int, _Builtin]
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| 198 | tracer, # type: dev.Tracer
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| 199 | errfmt # type: ui.ErrorFormatter
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| 200 | ):
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| 201 | self.mem = mem
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| 202 | self.exec_opts = exec_opts
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| 203 | self.mutable_opts = mutable_opts # for IsDisabled(), not mutating
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| 204 | self.procs = procs
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| 205 | self.hay_state = hay_state
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| 206 | self.builtins = builtins
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| 207 | self.tracer = tracer
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| 208 | self.errfmt = errfmt
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| 209 |
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| 210 | # Not a constructor argument
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| 211 | self.cmd_ev = None # type: cmd_eval.CommandEvaluator
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| 212 |
|
| 213 | def CheckCircularDeps(self):
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| 214 | # type: () -> None
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| 215 | assert self.cmd_ev is not None
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| 216 |
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| 217 | def RunSimpleCommand(self, cmd_val, cmd_st, run_flags):
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| 218 | # type: (cmd_value.Argv, CommandStatus, int) -> int
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| 219 | """Shared between ShellExecutor and PureExecutor"""
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| 220 | if len(cmd_val.arg_locs):
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| 221 | arg0_loc = cmd_val.arg_locs[0] # type: loc_t
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| 222 | else:
|
| 223 | arg0_loc = loc.Missing
|
| 224 |
|
| 225 | argv = cmd_val.argv
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| 226 | # This happens when you write "$@" but have no arguments.
|
| 227 | if len(argv) == 0:
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| 228 | if self.exec_opts.strict_argv():
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| 229 | e_die("Command evaluated to an empty argv array", arg0_loc)
|
| 230 | else:
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| 231 | return 0 # do nothing
|
| 232 |
|
| 233 | return self._RunSimpleCommand(argv[0], arg0_loc, cmd_val, cmd_st,
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| 234 | run_flags)
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| 235 |
|
| 236 | def _RunSimpleCommand(self, arg0, arg0_loc, cmd_val, cmd_st, run_flags):
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| 237 | # type: (str, loc_t, cmd_value.Argv, CommandStatus, int) -> int
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| 238 | raise NotImplementedError()
|
| 239 |
|
| 240 | def RunBuiltin(self, builtin_id, cmd_val):
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| 241 | # type: (int, cmd_value.Argv) -> int
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| 242 | """Run a builtin.
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| 243 |
|
| 244 | Also called by the 'builtin' builtin, in builtin/meta_oils.py
|
| 245 | """
|
| 246 | self.tracer.OnBuiltin(builtin_id, cmd_val.argv)
|
| 247 | builtin_proc = self.builtins[builtin_id]
|
| 248 | return self._RunBuiltinProc(builtin_proc, cmd_val)
|
| 249 |
|
| 250 | def _RunBuiltinProc(self, builtin_proc, cmd_val):
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| 251 | # type: (_Builtin, cmd_value.Argv) -> int
|
| 252 |
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| 253 | io_errors = [] # type: List[error.IOError_OSError]
|
| 254 | with ctx_FlushStdout(io_errors):
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| 255 | # note: could be second word, like 'builtin read'
|
| 256 | with ui.ctx_Location(self.errfmt, cmd_val.arg_locs[0]):
|
| 257 | try:
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| 258 | status = builtin_proc.Run(cmd_val)
|
| 259 | assert isinstance(status, int)
|
| 260 | except (IOError, OSError) as e:
|
| 261 | self.errfmt.PrintMessage(
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| 262 | '%s builtin I/O error: %s' %
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| 263 | (cmd_val.argv[0], pyutil.strerror(e)),
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| 264 | cmd_val.arg_locs[0])
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| 265 | return 1
|
| 266 | except error.Usage as e:
|
| 267 | arg0 = cmd_val.argv[0]
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| 268 | # e.g. 'type' doesn't accept flag '-x'
|
| 269 | self.errfmt.PrefixPrint(e.msg, '%r ' % arg0, e.location)
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| 270 | return 2 # consistent error code for usage error
|
| 271 |
|
| 272 | if len(io_errors): # e.g. disk full, ulimit
|
| 273 | self.errfmt.PrintMessage(
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| 274 | '%s builtin I/O error: %s' %
|
| 275 | (cmd_val.argv[0], pyutil.strerror(io_errors[0])),
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| 276 | cmd_val.arg_locs[0])
|
| 277 | return 1
|
| 278 |
|
| 279 | return status
|
| 280 |
|
| 281 | def _RunInvokable(self, proc_val, self_obj, arg0_loc, cmd_val):
|
| 282 | # type: (value_t, Optional[Obj], loc_t, cmd_value.Argv) -> int
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| 283 |
|
| 284 | cmd_val.self_obj = self_obj # MAYBE bind self
|
| 285 |
|
| 286 | if self.exec_opts.strict_errexit():
|
| 287 | disabled_tok = self.mutable_opts.ErrExitDisabledToken()
|
| 288 | if disabled_tok:
|
| 289 | self.errfmt.Print_('errexit was disabled for this construct',
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| 290 | disabled_tok)
|
| 291 | self.errfmt.StderrLine('')
|
| 292 | e_die(
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| 293 | "Can't run functions or procs while errexit is disabled (OILS-ERR-301)",
|
| 294 | arg0_loc)
|
| 295 |
|
| 296 | with tagswitch(proc_val) as case:
|
| 297 | if case(value_e.BuiltinProc):
|
| 298 | # Handle the special case of the BUILTIN proc
|
| 299 | # module_ysh.ModuleInvoke, which is returned on the Obj
|
| 300 | # created by 'use util.ysh'
|
| 301 | builtin_proc = cast(value.BuiltinProc, proc_val)
|
| 302 | b = cast(_Builtin, builtin_proc.builtin)
|
| 303 | status = self._RunBuiltinProc(b, cmd_val)
|
| 304 |
|
| 305 | elif case(value_e.Proc):
|
| 306 | proc = cast(value.Proc, proc_val)
|
| 307 | with dev.ctx_Tracer(self.tracer, 'proc', cmd_val.argv):
|
| 308 | # NOTE: Functions could call 'exit 42' directly, etc.
|
| 309 | status = self.cmd_ev.RunProc(proc, cmd_val)
|
| 310 |
|
| 311 | else:
|
| 312 | # GetInvokable() should only return 1 of 2 things
|
| 313 | raise AssertionError()
|
| 314 |
|
| 315 | return status
|
| 316 |
|
| 317 | def RunBackgroundJob(self, node):
|
| 318 | # type: (command_t) -> int
|
| 319 | return 0
|
| 320 |
|
| 321 | def RunPipeline(self, node, status_out):
|
| 322 | # type: (command.Pipeline, CommandStatus) -> None
|
| 323 | pass
|
| 324 |
|
| 325 | def RunSubshell(self, node):
|
| 326 | # type: (command_t) -> int
|
| 327 | return 0
|
| 328 |
|
| 329 | def CaptureStdout(self, node):
|
| 330 | # type: (command_t) -> Tuple[int, str]
|
| 331 | return 0, ''
|
| 332 |
|
| 333 | def Capture3(self, node):
|
| 334 | # type: (command_t) -> Tuple[int, str, str]
|
| 335 | return 0, '', ''
|
| 336 |
|
| 337 | def RunCommandSub(self, cs_part):
|
| 338 | # type: (CommandSub) -> str
|
| 339 | return ''
|
| 340 |
|
| 341 | def RunProcessSub(self, cs_part):
|
| 342 | # type: (CommandSub) -> str
|
| 343 | return ''
|
| 344 |
|
| 345 | def PushRedirects(self, redirects, err_out):
|
| 346 | # type: (List[RedirValue], List[error.IOError_OSError]) -> None
|
| 347 | pass
|
| 348 |
|
| 349 | def PopRedirects(self, num_redirects, err_out):
|
| 350 | # type: (int, List[error.IOError_OSError]) -> None
|
| 351 | pass
|
| 352 |
|
| 353 | def PushProcessSub(self):
|
| 354 | # type: () -> None
|
| 355 | pass
|
| 356 |
|
| 357 | def PopProcessSub(self, compound_st):
|
| 358 | # type: (StatusArray) -> None
|
| 359 | pass
|
| 360 |
|
| 361 |
|
| 362 | #
|
| 363 | # Abstract base classes
|
| 364 | #
|
| 365 |
|
| 366 |
|
| 367 | class _AssignBuiltin(object):
|
| 368 | """Interface for assignment builtins."""
|
| 369 |
|
| 370 | def __init__(self):
|
| 371 | # type: () -> None
|
| 372 | """Empty constructor for mycpp."""
|
| 373 | pass
|
| 374 |
|
| 375 | def Run(self, cmd_val):
|
| 376 | # type: (cmd_value.Assign) -> int
|
| 377 | raise NotImplementedError()
|
| 378 |
|
| 379 |
|
| 380 | class _Builtin(object):
|
| 381 | """All builtins except 'command' obey this interface.
|
| 382 |
|
| 383 | Assignment builtins use cmd_value.Assign; others use cmd_value.Argv.
|
| 384 | """
|
| 385 |
|
| 386 | def __init__(self):
|
| 387 | # type: () -> None
|
| 388 | """Empty constructor for mycpp."""
|
| 389 | pass
|
| 390 |
|
| 391 | def Run(self, cmd_val):
|
| 392 | # type: (cmd_value.Argv) -> int
|
| 393 | raise NotImplementedError()
|
| 394 |
|
| 395 |
|
| 396 | class _Callable(object):
|
| 397 | """Interface for functions in the runtime."""
|
| 398 |
|
| 399 | def __init__(self):
|
| 400 | # type: () -> None
|
| 401 | """Empty constructor for mycpp."""
|
| 402 | pass
|
| 403 |
|
| 404 | def Call(self, args):
|
| 405 | # type: (typed_args.Reader) -> value_t
|
| 406 | raise NotImplementedError()
|
| 407 |
|
| 408 |
|
| 409 | class ctx_MaybePure(object):
|
| 410 | """Enforce purity of the shell interpreter
|
| 411 |
|
| 412 | Use this for:
|
| 413 |
|
| 414 | --eval-pure
|
| 415 | func - pure functions
|
| 416 | eval() evalToDict() - builtin pure functions, not methods
|
| 417 | """
|
| 418 |
|
| 419 | def __init__(
|
| 420 | self,
|
| 421 | pure_ex, # type: Optional[_Executor]
|
| 422 | cmd_ev, # type: cmd_eval.CommandEvaluator
|
| 423 | ):
|
| 424 | # type: (...) -> None
|
| 425 | self.pure_ex = pure_ex
|
| 426 | if not pure_ex:
|
| 427 | return # do nothing
|
| 428 |
|
| 429 | word_ev = cmd_ev.word_ev
|
| 430 | expr_ev = cmd_ev.expr_ev
|
| 431 |
|
| 432 | # Save the Shell Executor
|
| 433 | self.saved = cmd_ev.shell_ex
|
| 434 | assert self.saved is word_ev.shell_ex
|
| 435 | assert self.saved is expr_ev.shell_ex
|
| 436 |
|
| 437 | # Patch evaluators to use the Pure Executor
|
| 438 | cmd_ev.shell_ex = pure_ex
|
| 439 | word_ev.shell_ex = pure_ex
|
| 440 | expr_ev.shell_ex = pure_ex
|
| 441 |
|
| 442 | self.cmd_ev = cmd_ev
|
| 443 |
|
| 444 | def __enter__(self):
|
| 445 | # type: () -> None
|
| 446 | pass
|
| 447 |
|
| 448 | def __exit__(self, type, value, traceback):
|
| 449 | # type: (Any, Any, Any) -> None
|
| 450 | if not self.pure_ex:
|
| 451 | return
|
| 452 |
|
| 453 | # Unpatch the evaluators
|
| 454 | self.cmd_ev.shell_ex = self.saved
|
| 455 | self.cmd_ev.word_ev.shell_ex = self.saved
|
| 456 | self.cmd_ev.expr_ev.shell_ex = self.saved
|
| 457 |
|
| 458 |
|
| 459 | class ctx_Redirect(object):
|
| 460 | """For closing files.
|
| 461 |
|
| 462 | This is asymmetric because if PushRedirects fails, then we don't execute
|
| 463 | the command at all.
|
| 464 |
|
| 465 | Example:
|
| 466 | { seq 3 > foo.txt; echo 4; } > bar.txt
|
| 467 | """
|
| 468 |
|
| 469 | def __init__(self, shell_ex, num_redirects, err_out):
|
| 470 | # type: (_Executor, int, List[error.IOError_OSError]) -> None
|
| 471 | self.shell_ex = shell_ex
|
| 472 | self.num_redirects = num_redirects
|
| 473 | self.err_out = err_out
|
| 474 |
|
| 475 | def __enter__(self):
|
| 476 | # type: () -> None
|
| 477 | pass
|
| 478 |
|
| 479 | def __exit__(self, type, value, traceback):
|
| 480 | # type: (Any, Any, Any) -> None
|
| 481 | self.shell_ex.PopRedirects(self.num_redirects, self.err_out)
|
| 482 |
|
| 483 |
|
| 484 | class ctx_ProcessSub(object):
|
| 485 | """For waiting on processes started during word evaluation.
|
| 486 |
|
| 487 | Example:
|
| 488 | diff <(seq 3) <(seq 4) > >(tac)
|
| 489 | """
|
| 490 |
|
| 491 | def __init__(self, shell_ex, process_sub_status):
|
| 492 | # type: (_Executor, StatusArray) -> None
|
| 493 | shell_ex.PushProcessSub()
|
| 494 | self.shell_ex = shell_ex
|
| 495 | self.process_sub_status = process_sub_status
|
| 496 |
|
| 497 | def __enter__(self):
|
| 498 | # type: () -> None
|
| 499 | pass
|
| 500 |
|
| 501 | def __exit__(self, type, value, traceback):
|
| 502 | # type: (Any, Any, Any) -> None
|
| 503 |
|
| 504 | # Wait and return array to set _process_sub_status
|
| 505 | self.shell_ex.PopProcessSub(self.process_sub_status)
|
| 506 |
|
| 507 |
|
| 508 | class ctx_FlushStdout(object):
|
| 509 |
|
| 510 | def __init__(self, err_out):
|
| 511 | # type: (List[error.IOError_OSError]) -> None
|
| 512 | self.err_out = err_out
|
| 513 |
|
| 514 | def __enter__(self):
|
| 515 | # type: () -> None
|
| 516 | pass
|
| 517 |
|
| 518 | def __exit__(self, type, value, traceback):
|
| 519 | # type: (Any, Any, Any) -> None
|
| 520 |
|
| 521 | # Can't raise exception in destructor! So we append it to out param.
|
| 522 | err = pyos.FlushStdout()
|
| 523 | if err is not None:
|
| 524 | self.err_out.append(err)
|