| 1 | """vm.py: Library for executing shell."""
|
| 2 | from __future__ import print_function
|
| 3 |
|
| 4 | from _devbuild.gen.id_kind_asdl import Id
|
| 5 | from _devbuild.gen.runtime_asdl import (CommandStatus, StatusArray, flow_e,
|
| 6 | flow_t)
|
| 7 | from _devbuild.gen.syntax_asdl import Token
|
| 8 | from _devbuild.gen.value_asdl import value, value_t
|
| 9 | from core import error
|
| 10 | from core import pyos
|
| 11 | from mycpp.mylib import log
|
| 12 |
|
| 13 | from typing import List, Any, TYPE_CHECKING
|
| 14 | if TYPE_CHECKING:
|
| 15 | from _devbuild.gen.runtime_asdl import cmd_value, RedirValue
|
| 16 | from _devbuild.gen.syntax_asdl import (command, command_t, CommandSub)
|
| 17 | from frontend import typed_args
|
| 18 | from osh import sh_expr_eval
|
| 19 | from osh.sh_expr_eval import ArithEvaluator
|
| 20 | from osh.sh_expr_eval import BoolEvaluator
|
| 21 | from ysh.expr_eval import ExprEvaluator
|
| 22 | from osh.word_eval import NormalWordEvaluator
|
| 23 | from osh.cmd_eval import CommandEvaluator
|
| 24 | from osh import prompt
|
| 25 | from core import dev
|
| 26 | from core import state
|
| 27 |
|
| 28 | _ = log
|
| 29 |
|
| 30 |
|
| 31 | class ControlFlow(Exception):
|
| 32 | """Internal exception for control flow.
|
| 33 |
|
| 34 | Used by CommandEvaluator and 'source' builtin
|
| 35 |
|
| 36 | break and continue are caught by loops, return is caught by functions.
|
| 37 | """
|
| 38 | pass
|
| 39 |
|
| 40 |
|
| 41 | class IntControlFlow(Exception):
|
| 42 |
|
| 43 | def __init__(self, token, arg):
|
| 44 | # type: (Token, int) -> None
|
| 45 | """
|
| 46 | Args:
|
| 47 | token: the keyword token
|
| 48 | arg: exit code to 'return', or number of levels to break/continue
|
| 49 | """
|
| 50 | self.token = token
|
| 51 | self.arg = arg
|
| 52 |
|
| 53 | def IsReturn(self):
|
| 54 | # type: () -> bool
|
| 55 | return self.token.id == Id.ControlFlow_Return
|
| 56 |
|
| 57 | def IsBreak(self):
|
| 58 | # type: () -> bool
|
| 59 | return self.token.id == Id.ControlFlow_Break
|
| 60 |
|
| 61 | def IsContinue(self):
|
| 62 | # type: () -> bool
|
| 63 | return self.token.id == Id.ControlFlow_Continue
|
| 64 |
|
| 65 | def StatusCode(self):
|
| 66 | # type: () -> int
|
| 67 | assert self.IsReturn()
|
| 68 | # All shells except dash do this truncation.
|
| 69 | # turn 257 into 1, and -1 into 255.
|
| 70 | return self.arg & 0xff
|
| 71 |
|
| 72 | def HandleLoop(self):
|
| 73 | # type: () -> flow_t
|
| 74 | """Mutates this exception and returns what the caller should do."""
|
| 75 |
|
| 76 | if self.IsBreak():
|
| 77 | self.arg -= 1
|
| 78 | if self.arg == 0:
|
| 79 | return flow_e.Break # caller should break out of loop
|
| 80 |
|
| 81 | elif self.IsContinue():
|
| 82 | self.arg -= 1
|
| 83 | if self.arg == 0:
|
| 84 | return flow_e.Nothing # do nothing to continue
|
| 85 |
|
| 86 | # return / break 2 / continue 2 need to pop up more
|
| 87 | return flow_e.Raise
|
| 88 |
|
| 89 | def __repr__(self):
|
| 90 | # type: () -> str
|
| 91 | return '<IntControlFlow %s %s>' % (self.token, self.arg)
|
| 92 |
|
| 93 |
|
| 94 | class ValueControlFlow(Exception):
|
| 95 |
|
| 96 | def __init__(self, token, value):
|
| 97 | # type: (Token, value_t) -> None
|
| 98 | """
|
| 99 | Args:
|
| 100 | token: the keyword token
|
| 101 | value: value_t to 'return' from a function
|
| 102 | """
|
| 103 | self.token = token
|
| 104 | self.value = value
|
| 105 |
|
| 106 | def __repr__(self):
|
| 107 | # type: () -> str
|
| 108 | return '<ValueControlFlow %s %s>' % (self.token, self.value)
|
| 109 |
|
| 110 |
|
| 111 | def InitUnsafeArith(mem, word_ev, unsafe_arith):
|
| 112 | # type: (state.Mem, NormalWordEvaluator, sh_expr_eval.UnsafeArith) -> None
|
| 113 | """Wire up circular dependencies for UnsafeArith."""
|
| 114 | mem.unsafe_arith = unsafe_arith # for 'declare -n' nameref expansion of a[i]
|
| 115 | word_ev.unsafe_arith = unsafe_arith # for ${!ref} expansion of a[i]
|
| 116 |
|
| 117 |
|
| 118 | def InitCircularDeps(
|
| 119 | arith_ev, # type: ArithEvaluator
|
| 120 | bool_ev, # type: BoolEvaluator
|
| 121 | expr_ev, # type: ExprEvaluator
|
| 122 | word_ev, # type: NormalWordEvaluator
|
| 123 | cmd_ev, # type: CommandEvaluator
|
| 124 | shell_ex, # type: _Executor
|
| 125 | prompt_ev, # type: prompt.Evaluator
|
| 126 | global_io, # type: value.IO
|
| 127 | tracer, # type: dev.Tracer
|
| 128 | ):
|
| 129 | # type: (...) -> None
|
| 130 | """Wire up mutually recursive evaluators and runtime objects."""
|
| 131 | arith_ev.word_ev = word_ev
|
| 132 | bool_ev.word_ev = word_ev
|
| 133 |
|
| 134 | if expr_ev: # for pure OSH
|
| 135 | expr_ev.shell_ex = shell_ex
|
| 136 | expr_ev.cmd_ev = cmd_ev
|
| 137 | expr_ev.word_ev = word_ev
|
| 138 |
|
| 139 | word_ev.arith_ev = arith_ev
|
| 140 | word_ev.expr_ev = expr_ev
|
| 141 | word_ev.prompt_ev = prompt_ev
|
| 142 | word_ev.shell_ex = shell_ex
|
| 143 |
|
| 144 | cmd_ev.shell_ex = shell_ex
|
| 145 | cmd_ev.arith_ev = arith_ev
|
| 146 | cmd_ev.bool_ev = bool_ev
|
| 147 | cmd_ev.expr_ev = expr_ev
|
| 148 | cmd_ev.word_ev = word_ev
|
| 149 | cmd_ev.tracer = tracer
|
| 150 |
|
| 151 | shell_ex.cmd_ev = cmd_ev
|
| 152 |
|
| 153 | prompt_ev.word_ev = word_ev
|
| 154 | prompt_ev.expr_ev = expr_ev
|
| 155 | prompt_ev.global_io = global_io
|
| 156 |
|
| 157 | tracer.word_ev = word_ev
|
| 158 |
|
| 159 | arith_ev.CheckCircularDeps()
|
| 160 | bool_ev.CheckCircularDeps()
|
| 161 | if expr_ev:
|
| 162 | expr_ev.CheckCircularDeps()
|
| 163 | word_ev.CheckCircularDeps()
|
| 164 | cmd_ev.CheckCircularDeps()
|
| 165 | shell_ex.CheckCircularDeps()
|
| 166 | prompt_ev.CheckCircularDeps()
|
| 167 | tracer.CheckCircularDeps()
|
| 168 |
|
| 169 |
|
| 170 | class _Executor(object):
|
| 171 |
|
| 172 | def __init__(self):
|
| 173 | # type: () -> None
|
| 174 | self.cmd_ev = None # type: CommandEvaluator
|
| 175 |
|
| 176 | def CheckCircularDeps(self):
|
| 177 | # type: () -> None
|
| 178 | pass
|
| 179 |
|
| 180 | def RunBuiltin(self, builtin_id, cmd_val):
|
| 181 | # type: (int, cmd_value.Argv) -> int
|
| 182 | """The 'builtin' builtin in osh/builtin_meta.py needs this."""
|
| 183 | return 0
|
| 184 |
|
| 185 | def RunSimpleCommand(self, cmd_val, cmd_st, run_flags):
|
| 186 | # type: (cmd_value.Argv, CommandStatus, int) -> int
|
| 187 | return 0
|
| 188 |
|
| 189 | def RunBackgroundJob(self, node):
|
| 190 | # type: (command_t) -> int
|
| 191 | return 0
|
| 192 |
|
| 193 | def RunPipeline(self, node, status_out):
|
| 194 | # type: (command.Pipeline, CommandStatus) -> None
|
| 195 | pass
|
| 196 |
|
| 197 | def RunSubshell(self, node):
|
| 198 | # type: (command_t) -> int
|
| 199 | return 0
|
| 200 |
|
| 201 | def RunCommandSub(self, cs_part):
|
| 202 | # type: (CommandSub) -> str
|
| 203 | return ''
|
| 204 |
|
| 205 | def RunProcessSub(self, cs_part):
|
| 206 | # type: (CommandSub) -> str
|
| 207 | return ''
|
| 208 |
|
| 209 | def PushRedirects(self, redirects, err_out):
|
| 210 | # type: (List[RedirValue], List[error.IOError_OSError]) -> None
|
| 211 | pass
|
| 212 |
|
| 213 | def PopRedirects(self, num_redirects, err_out):
|
| 214 | # type: (int, List[error.IOError_OSError]) -> None
|
| 215 | pass
|
| 216 |
|
| 217 | def PushProcessSub(self):
|
| 218 | # type: () -> None
|
| 219 | pass
|
| 220 |
|
| 221 | def PopProcessSub(self, compound_st):
|
| 222 | # type: (StatusArray) -> None
|
| 223 | pass
|
| 224 |
|
| 225 |
|
| 226 | #
|
| 227 | # Abstract base classes
|
| 228 | #
|
| 229 |
|
| 230 |
|
| 231 | class _AssignBuiltin(object):
|
| 232 | """Interface for assignment builtins."""
|
| 233 |
|
| 234 | def __init__(self):
|
| 235 | # type: () -> None
|
| 236 | """Empty constructor for mycpp."""
|
| 237 | pass
|
| 238 |
|
| 239 | def Run(self, cmd_val):
|
| 240 | # type: (cmd_value.Assign) -> int
|
| 241 | raise NotImplementedError()
|
| 242 |
|
| 243 |
|
| 244 | class _Builtin(object):
|
| 245 | """All builtins except 'command' obey this interface.
|
| 246 |
|
| 247 | Assignment builtins use cmd_value.Assign; others use cmd_value.Argv.
|
| 248 | """
|
| 249 |
|
| 250 | def __init__(self):
|
| 251 | # type: () -> None
|
| 252 | """Empty constructor for mycpp."""
|
| 253 | pass
|
| 254 |
|
| 255 | def Run(self, cmd_val):
|
| 256 | # type: (cmd_value.Argv) -> int
|
| 257 | raise NotImplementedError()
|
| 258 |
|
| 259 |
|
| 260 | class _Callable(object):
|
| 261 | """Interface for functions in the runtime."""
|
| 262 |
|
| 263 | def __init__(self):
|
| 264 | # type: () -> None
|
| 265 | """Empty constructor for mycpp."""
|
| 266 | pass
|
| 267 |
|
| 268 | def Call(self, args):
|
| 269 | # type: (typed_args.Reader) -> value_t
|
| 270 | raise NotImplementedError()
|
| 271 |
|
| 272 |
|
| 273 | class ctx_Redirect(object):
|
| 274 | """For closing files.
|
| 275 |
|
| 276 | This is asymmetric because if PushRedirects fails, then we don't execute
|
| 277 | the command at all.
|
| 278 |
|
| 279 | Example:
|
| 280 | { seq 3 > foo.txt; echo 4; } > bar.txt
|
| 281 | """
|
| 282 |
|
| 283 | def __init__(self, shell_ex, num_redirects, err_out):
|
| 284 | # type: (_Executor, int, List[error.IOError_OSError]) -> None
|
| 285 | self.shell_ex = shell_ex
|
| 286 | self.num_redirects = num_redirects
|
| 287 | self.err_out = err_out
|
| 288 |
|
| 289 | def __enter__(self):
|
| 290 | # type: () -> None
|
| 291 | pass
|
| 292 |
|
| 293 | def __exit__(self, type, value, traceback):
|
| 294 | # type: (Any, Any, Any) -> None
|
| 295 | self.shell_ex.PopRedirects(self.num_redirects, self.err_out)
|
| 296 |
|
| 297 |
|
| 298 | class ctx_ProcessSub(object):
|
| 299 | """For waiting on processes started during word evaluation.
|
| 300 |
|
| 301 | Example:
|
| 302 | diff <(seq 3) <(seq 4) > >(tac)
|
| 303 | """
|
| 304 |
|
| 305 | def __init__(self, shell_ex, process_sub_status):
|
| 306 | # type: (_Executor, StatusArray) -> None
|
| 307 | shell_ex.PushProcessSub()
|
| 308 | self.shell_ex = shell_ex
|
| 309 | self.process_sub_status = process_sub_status
|
| 310 |
|
| 311 | def __enter__(self):
|
| 312 | # type: () -> None
|
| 313 | pass
|
| 314 |
|
| 315 | def __exit__(self, type, value, traceback):
|
| 316 | # type: (Any, Any, Any) -> None
|
| 317 |
|
| 318 | # Wait and return array to set _process_sub_status
|
| 319 | self.shell_ex.PopProcessSub(self.process_sub_status)
|
| 320 |
|
| 321 |
|
| 322 | class ctx_FlushStdout(object):
|
| 323 |
|
| 324 | def __init__(self, err_out):
|
| 325 | # type: (List[error.IOError_OSError]) -> None
|
| 326 | self.err_out = err_out
|
| 327 |
|
| 328 | def __enter__(self):
|
| 329 | # type: () -> None
|
| 330 | pass
|
| 331 |
|
| 332 | def __exit__(self, type, value, traceback):
|
| 333 | # type: (Any, Any, Any) -> None
|
| 334 |
|
| 335 | # Can't raise exception in destructor! So we append it to out param.
|
| 336 | err = pyos.FlushStdout()
|
| 337 | if err is not None:
|
| 338 | self.err_out.append(err)
|