Beispiel #1
0
def AddProcess(
    b,  # type: Dict[int, vm._Builtin]
    mem,  # type: state.Mem
    shell_ex,  # type: vm._Executor
    ext_prog,  # type: process.ExternalProgram
    fd_state,  # type: process.FdState
    job_state,  # type: process.JobState
    waiter,  # type: process.Waiter
    tracer,  # type: dev.Tracer
    search_path,  # type: state.SearchPath
    errfmt  # type: ui.ErrorFormatter
    ):
    # type: (...) -> None

  # Process
  b[builtin_i.exec_] = builtin_process.Exec(mem, ext_prog, fd_state,
                                            search_path, errfmt)
  b[builtin_i.wait] = builtin_process.Wait(waiter, job_state, mem, tracer,
                                           errfmt)
  b[builtin_i.jobs] = builtin_process.Jobs(job_state)
  b[builtin_i.fg] = builtin_process.Fg(job_state, waiter)
  b[builtin_i.bg] = builtin_process.Bg(job_state)
  b[builtin_i.umask] = builtin_process.Umask()
  b[builtin_i.fork] = builtin_process.Fork(shell_ex)
  b[builtin_i.forkwait] = builtin_process.ForkWait(shell_ex)
Beispiel #2
0
def ShellMain(lang, argv0, argv, login_shell):
    """Used by bin/osh and bin/oil.

  Args:
    lang: 'osh' or 'oil'
    argv0, argv: So we can also invoke bin/osh as 'oil.ovm osh'.  Like busybox.
    login_shell: Was - on the front?
  """
    # Differences between osh and oil:
    # - --help?  I guess Oil has a SUPERSET of OSH options.
    # - oshrc vs oilrc
    # - the parser and executor
    # - Change the prompt in the interactive shell?

    assert lang in ('osh', 'oil'), lang

    arg_r = args.Reader(argv)
    try:
        opts = OSH_SPEC.Parse(arg_r)
    except args.UsageError as e:
        ui.Stderr('osh usage error: %s', e.msg)
        return 2

    # NOTE: This has a side effect of deleting _OVM_* from the environment!
    # TODO: Thread this throughout the program, and get rid of the global
    # variable in core/util.py.  Rename to InitResourceLaoder().  It's now only
    # used for the 'help' builtin and --version.
    loader = pyutil.GetResourceLoader()

    if opts.help:
        builtin.Help(['%s-usage' % lang], loader)
        return 0
    if opts.version:
        # OSH version is the only binary in Oil right now, so it's all one version.
        _ShowVersion()
        return 0

    if arg_r.AtEnd():
        dollar0 = argv0
        has_main = False
    else:
        dollar0 = arg_r.Peek()  # the script name, or the arg after -c
        has_main = True

    arena = alloc.Arena()
    errfmt = ui.ErrorFormatter(arena)

    # NOTE: has_main is only for ${BASH_SOURCE[@} and family.  Could be a
    # required arg.
    mem = state.Mem(dollar0,
                    argv[arg_r.i + 1:],
                    posix.environ,
                    arena,
                    has_main=has_main)
    builtin_funcs.Init(mem)

    procs = {}

    job_state = process.JobState()
    fd_state = process.FdState(errfmt, job_state)
    parse_opts = parse_lib.OilParseOptions()
    exec_opts = state.ExecOpts(mem, parse_opts, line_input)

    if opts.show_options:  # special case: sh -o
        exec_opts.ShowOptions([])
        return 0

    builtin_pure.SetExecOpts(exec_opts, opts.opt_changes, opts.shopt_changes)
    aliases = {}  # feedback between runtime and parser

    oil_grammar = meta.LoadOilGrammar(loader)

    if opts.one_pass_parse and not exec_opts.noexec:
        raise args.UsageError('--one-pass-parse requires noexec (-n)')
    parse_ctx = parse_lib.ParseContext(arena,
                                       parse_opts,
                                       aliases,
                                       oil_grammar,
                                       one_pass_parse=opts.one_pass_parse)

    # Three ParseContext instances SHARE aliases.
    comp_arena = alloc.Arena()
    comp_arena.PushSource(source.Unused('completion'))
    trail1 = parse_lib.Trail()
    # one_pass_parse needs to be turned on to complete inside backticks.  TODO:
    # fix the issue where ` gets erased because it's not part of
    # set_completer_delims().
    comp_ctx = parse_lib.ParseContext(comp_arena,
                                      parse_opts,
                                      aliases,
                                      oil_grammar,
                                      trail=trail1,
                                      one_pass_parse=True)

    hist_arena = alloc.Arena()
    hist_arena.PushSource(source.Unused('history'))
    trail2 = parse_lib.Trail()
    hist_ctx = parse_lib.ParseContext(hist_arena,
                                      parse_opts,
                                      aliases,
                                      oil_grammar,
                                      trail=trail2)

    # Deps helps manages dependencies.  These dependencies are circular:
    # - ex and word_ev, arith_ev -- for command sub, arith sub
    # - arith_ev and word_ev -- for $(( ${a} )) and $x$(( 1 ))
    # - ex and builtins (which execute code, like eval)
    # - prompt_ev needs word_ev for $PS1, which needs prompt_ev for @P
    exec_deps = cmd_exec.Deps()

    # TODO: In general, exec_deps are shared between the mutually recursive
    # evaluators.  Some of the four below are only shared between a builtin and
    # the Executor, so we could put them somewhere else.
    exec_deps.traps = {}
    exec_deps.trap_nodes = []  # TODO: Clear on fork() to avoid duplicates

    exec_deps.job_state = job_state
    # note: exec_opts.interactive set later
    exec_deps.waiter = process.Waiter(job_state, exec_opts)
    exec_deps.errfmt = errfmt

    my_pid = posix.getpid()

    debug_path = ''
    debug_dir = posix.environ.get('OSH_DEBUG_DIR')
    if opts.debug_file:  # --debug-file takes precedence over OSH_DEBUG_DIR
        debug_path = opts.debug_file
    elif debug_dir:
        debug_path = os_path.join(debug_dir, '%d-osh.log' % my_pid)

    if debug_path:
        # This will be created as an empty file if it doesn't exist, or it could be
        # a pipe.
        try:
            debug_f = util.DebugFile(fd_state.Open(debug_path, mode='w'))
        except OSError as e:
            ui.Stderr("osh: Couldn't open %r: %s", debug_path,
                      posix.strerror(e.errno))
            return 2
    else:
        debug_f = util.NullDebugFile()

    exec_deps.debug_f = debug_f

    # Not using datetime for dependency reasons.  TODO: maybe show the date at
    # the beginning of the log, and then only show time afterward?  To save
    # space, and make space for microseconds.  (datetime supports microseconds
    # but time.strftime doesn't).
    iso_stamp = time.strftime("%Y-%m-%d %H:%M:%S")
    debug_f.log('%s [%d] OSH started with argv %s', iso_stamp, my_pid, argv)
    if debug_path:
        debug_f.log('Writing logs to %r', debug_path)

    interp = posix.environ.get('OSH_HIJACK_SHEBANG', '')
    exec_deps.search_path = state.SearchPath(mem)
    exec_deps.ext_prog = process.ExternalProgram(interp, fd_state,
                                                 exec_deps.search_path, errfmt,
                                                 debug_f)

    splitter = split.SplitContext(mem)
    exec_deps.splitter = splitter

    # split() builtin
    builtin_funcs.SetGlobalFunc(mem, 'split',
                                lambda s: splitter.SplitForWordEval(s))

    # This could just be OSH_DEBUG_STREAMS='debug crash' ?  That might be
    # stuffing too much into one, since a .json crash dump isn't a stream.
    crash_dump_dir = posix.environ.get('OSH_CRASH_DUMP_DIR', '')
    exec_deps.dumper = dev.CrashDumper(crash_dump_dir)

    if opts.xtrace_to_debug_file:
        trace_f = debug_f
    else:
        trace_f = util.DebugFile(sys.stderr)
    exec_deps.trace_f = trace_f

    comp_lookup = completion.Lookup()

    # Various Global State objects to work around readline interfaces
    compopt_state = completion.OptionState()
    comp_ui_state = comp_ui.State()
    prompt_state = comp_ui.PromptState()

    dir_stack = state.DirStack()

    new_var = builtin_assign.NewVar(mem, procs, errfmt)

    builtins = {  # Lookup
        builtin_e.ECHO: builtin_pure.Echo(exec_opts),
        builtin_e.PRINTF: builtin_printf.Printf(mem, parse_ctx, errfmt),

        builtin_e.PUSHD: builtin.Pushd(mem, dir_stack, errfmt),
        builtin_e.POPD: builtin.Popd(mem, dir_stack, errfmt),
        builtin_e.DIRS: builtin.Dirs(mem, dir_stack, errfmt),
        builtin_e.PWD: builtin.Pwd(mem, errfmt),

        builtin_e.READ: builtin.Read(splitter, mem),
        builtin_e.HELP: builtin.Help(loader, errfmt),
        builtin_e.HISTORY: builtin.History(line_input),

        # Completion (more added below)
        builtin_e.COMPOPT: builtin_comp.CompOpt(compopt_state, errfmt),
        builtin_e.COMPADJUST: builtin_comp.CompAdjust(mem),

        # test / [ differ by need_right_bracket
        builtin_e.TEST: builtin_bracket.Test(False, errfmt),
        builtin_e.BRACKET: builtin_bracket.Test(True, errfmt),

        # Assignment (which are pure)
        builtin_e.DECLARE: new_var,
        builtin_e.TYPESET: new_var,
        builtin_e.LOCAL: new_var,

        builtin_e.EXPORT: builtin_assign.Export(mem, errfmt),
        builtin_e.READONLY: builtin_assign.Readonly(mem, errfmt),

        builtin_e.UNSET: builtin_assign.Unset(mem, procs, errfmt),
        builtin_e.SHIFT: builtin_assign.Shift(mem),

        # Pure
        builtin_e.SET: builtin_pure.Set(exec_opts, mem),
        builtin_e.SHOPT: builtin_pure.Shopt(exec_opts),

        builtin_e.ALIAS: builtin_pure.Alias(aliases, errfmt),
        builtin_e.UNALIAS: builtin_pure.UnAlias(aliases, errfmt),

        builtin_e.TYPE: builtin_pure.Type(procs, aliases, exec_deps.search_path),
        builtin_e.HASH: builtin_pure.Hash(exec_deps.search_path),
        builtin_e.GETOPTS: builtin_pure.GetOpts(mem, errfmt),

        builtin_e.COLON: lambda arg_vec: 0,  # a "special" builtin 
        builtin_e.TRUE: lambda arg_vec: 0,
        builtin_e.FALSE: lambda arg_vec: 1,

        # Process
        builtin_e.WAIT: builtin_process.Wait(exec_deps.waiter,
                                             exec_deps.job_state, mem, errfmt),
        builtin_e.JOBS: builtin_process.Jobs(exec_deps.job_state),
        builtin_e.FG: builtin_process.Fg(exec_deps.job_state, exec_deps.waiter),
        builtin_e.BG: builtin_process.Bg(exec_deps.job_state),
        builtin_e.UMASK: builtin_process.Umask,

        # Oil
        builtin_e.REPR: builtin_oil.Repr(mem, errfmt),
        builtin_e.PUSH: builtin_oil.Push(mem, errfmt),
        builtin_e.USE: builtin_oil.Use(mem, errfmt),
    }

    ex = cmd_exec.Executor(mem, fd_state, procs, builtins, exec_opts,
                           parse_ctx, exec_deps)
    exec_deps.ex = ex

    word_ev = word_eval.NormalWordEvaluator(mem, exec_opts, exec_deps, arena)
    exec_deps.word_ev = word_ev

    arith_ev = osh_expr_eval.ArithEvaluator(mem, exec_opts, word_ev, errfmt)
    exec_deps.arith_ev = arith_ev
    word_ev.arith_ev = arith_ev  # Another circular dependency

    bool_ev = osh_expr_eval.BoolEvaluator(mem, exec_opts, word_ev, errfmt)
    exec_deps.bool_ev = bool_ev

    expr_ev = expr_eval.OilEvaluator(mem, procs, ex, word_ev, errfmt)
    exec_deps.expr_ev = expr_ev

    tracer = dev.Tracer(parse_ctx, exec_opts, mem, word_ev, trace_f)
    exec_deps.tracer = tracer

    # HACK for circular deps
    ex.word_ev = word_ev
    ex.arith_ev = arith_ev
    ex.bool_ev = bool_ev
    ex.expr_ev = expr_ev
    ex.tracer = tracer

    word_ev.expr_ev = expr_ev

    spec_builder = builtin_comp.SpecBuilder(ex, parse_ctx, word_ev, splitter,
                                            comp_lookup)

    # Add some builtins that depend on the executor!
    complete_builtin = builtin_comp.Complete(spec_builder, comp_lookup)
    builtins[builtin_e.COMPLETE] = complete_builtin
    builtins[builtin_e.COMPGEN] = builtin_comp.CompGen(spec_builder)
    builtins[builtin_e.CD] = builtin.Cd(mem, dir_stack, ex, errfmt)
    builtins[builtin_e.JSON] = builtin_oil.Json(mem, ex, errfmt)

    sig_state = process.SignalState()
    sig_state.InitShell()

    builtins[builtin_e.TRAP] = builtin_process.Trap(sig_state, exec_deps.traps,
                                                    exec_deps.trap_nodes, ex,
                                                    errfmt)

    if lang == 'oil':
        # The Oil executor wraps an OSH executor?  It needs to be able to source
        # it.
        ex = oil_cmd_exec.OilExecutor(ex)

    # PromptEvaluator rendering is needed in non-interactive shells for @P.
    prompt_ev = prompt.Evaluator(lang, parse_ctx, ex, mem)
    exec_deps.prompt_ev = prompt_ev
    word_ev.prompt_ev = prompt_ev  # HACK for circular deps

    # History evaluation is a no-op if line_input is None.
    hist_ev = history.Evaluator(line_input, hist_ctx, debug_f)

    if opts.c is not None:
        arena.PushSource(source.CFlag())
        line_reader = reader.StringLineReader(opts.c, arena)
        if opts.i:  # -c and -i can be combined
            exec_opts.interactive = True

    elif opts.i:  # force interactive
        arena.PushSource(source.Stdin(' -i'))
        line_reader = reader.InteractiveLineReader(arena, prompt_ev, hist_ev,
                                                   line_input, prompt_state,
                                                   sig_state)
        exec_opts.interactive = True

    else:
        try:
            script_name = arg_r.Peek()
        except IndexError:
            if sys.stdin.isatty():
                arena.PushSource(source.Interactive())
                line_reader = reader.InteractiveLineReader(
                    arena, prompt_ev, hist_ev, line_input, prompt_state,
                    sig_state)
                exec_opts.interactive = True
            else:
                arena.PushSource(source.Stdin(''))
                line_reader = reader.FileLineReader(sys.stdin, arena)
        else:
            arena.PushSource(source.MainFile(script_name))
            try:
                f = fd_state.Open(script_name)
            except OSError as e:
                ui.Stderr("osh: Couldn't open %r: %s", script_name,
                          posix.strerror(e.errno))
                return 1
            line_reader = reader.FileLineReader(f, arena)

    # TODO: assert arena.NumSourcePaths() == 1
    # TODO: .rc file needs its own arena.
    if lang == 'osh':
        c_parser = parse_ctx.MakeOshParser(line_reader)
    else:
        c_parser = parse_ctx.MakeOilParser(line_reader)

    if exec_opts.interactive:
        # Calculate ~/.config/oil/oshrc or oilrc
        # Use ~/.config/oil to avoid cluttering the user's home directory.  Some
        # users may want to ln -s ~/.config/oil/oshrc ~/oshrc or ~/.oshrc.

        # https://unix.stackexchange.com/questions/24347/why-do-some-applications-use-config-appname-for-their-config-data-while-other
        home_dir = process.GetHomeDir()
        assert home_dir is not None
        rc_path = opts.rcfile or os_path.join(home_dir, '.config/oil',
                                              lang + 'rc')

        history_filename = os_path.join(home_dir, '.config/oil',
                                        'history_' + lang)

        if line_input:
            # NOTE: We're using a different WordEvaluator here.
            ev = word_eval.CompletionWordEvaluator(mem, exec_opts, exec_deps,
                                                   arena)
            root_comp = completion.RootCompleter(ev, mem, comp_lookup,
                                                 compopt_state, comp_ui_state,
                                                 comp_ctx, debug_f)

            term_width = 0
            if opts.completion_display == 'nice':
                try:
                    term_width = libc.get_terminal_width()
                except IOError:  # stdin not a terminal
                    pass

            if term_width != 0:
                display = comp_ui.NiceDisplay(term_width, comp_ui_state,
                                              prompt_state, debug_f,
                                              line_input)
            else:
                display = comp_ui.MinimalDisplay(comp_ui_state, prompt_state,
                                                 debug_f)

            _InitReadline(line_input, history_filename, root_comp, display,
                          debug_f)
            _InitDefaultCompletions(ex, complete_builtin, comp_lookup)

        else:  # Without readline module
            display = comp_ui.MinimalDisplay(comp_ui_state, prompt_state,
                                             debug_f)

        sig_state.InitInteractiveShell(display)

        # NOTE: Call this AFTER _InitDefaultCompletions.
        try:
            SourceStartupFile(rc_path, lang, parse_ctx, ex)
        except util.UserExit as e:
            return e.status

        line_reader.Reset()  # After sourcing startup file, render $PS1

        prompt_plugin = prompt.UserPlugin(mem, parse_ctx, ex)
        try:
            status = main_loop.Interactive(opts, ex, c_parser, display,
                                           prompt_plugin, errfmt)
            if ex.MaybeRunExitTrap():
                status = ex.LastStatus()
        except util.UserExit as e:
            status = e.status
        return status

    nodes_out = [] if exec_opts.noexec else None

    if nodes_out is None and opts.parser_mem_dump:
        raise args.UsageError('--parser-mem-dump can only be used with -n')

    _tlog('Execute(node)')
    try:
        status = main_loop.Batch(ex, c_parser, arena, nodes_out=nodes_out)
        if ex.MaybeRunExitTrap():
            status = ex.LastStatus()
    except util.UserExit as e:
        status = e.status

    # Only print nodes if the whole parse succeeded.
    if nodes_out is not None and status == 0:
        if opts.parser_mem_dump:  # only valid in -n mode
            # This might be superstition, but we want to let the value stabilize
            # after parsing.  bash -c 'cat /proc/$$/status' gives different results
            # with a sleep.
            time.sleep(0.001)
            input_path = '/proc/%d/status' % posix.getpid()
            with open(input_path) as f, open(opts.parser_mem_dump, 'w') as f2:
                contents = f.read()
                f2.write(contents)
                log('Wrote %s to %s (--parser-mem-dump)', input_path,
                    opts.parser_mem_dump)

        ui.PrintAst(nodes_out, opts)

    # NOTE: 'exit 1' is ControlFlow and gets here, but subshell/commandsub
    # don't because they call sys.exit().
    if opts.runtime_mem_dump:
        # This might be superstition, but we want to let the value stabilize
        # after parsing.  bash -c 'cat /proc/$$/status' gives different results
        # with a sleep.
        time.sleep(0.001)
        input_path = '/proc/%d/status' % posix.getpid()
        with open(input_path) as f, open(opts.runtime_mem_dump, 'w') as f2:
            contents = f.read()
            f2.write(contents)
            log('Wrote %s to %s (--runtime-mem-dump)', input_path,
                opts.runtime_mem_dump)

    # NOTE: We haven't closed the file opened with fd_state.Open
    return status
Beispiel #3
0
def ShellMain(lang, argv0, argv, login_shell):
    # type: (str, str, List[str], bool) -> int
    """Used by bin/osh and bin/oil.

  Args:
    lang: 'osh' or 'oil'
    argv0, argv: So we can also invoke bin/osh as 'oil.ovm osh'.  Like busybox.
    login_shell: Was - on the front?
  """
    # Differences between osh and oil:
    # - --help?  I guess Oil has a SUPERSET of OSH options.
    # - oshrc vs oilrc
    # - the parser and executor
    # - Change the prompt in the interactive shell?

    assert lang in ('osh', 'oil'), lang

    arg_r = args.Reader(argv)
    try:
        opts = OSH_SPEC.Parse(arg_r)
    except args.UsageError as e:
        ui.Stderr('osh usage error: %s', e.msg)
        return 2

    # NOTE: This has a side effect of deleting _OVM_* from the environment!
    # TODO: Thread this throughout the program, and get rid of the global
    # variable in core/util.py.  Rename to InitResourceLaoder().  It's now only
    # used for the 'help' builtin and --version.
    loader = pyutil.GetResourceLoader()

    if opts.help:
        builtin_misc.Help(['%s-usage' % lang], loader)
        return 0
    if opts.version:
        # OSH version is the only binary in Oil right now, so it's all one version.
        _ShowVersion()
        return 0

    no_str = None  # type: str

    debug_stack = []
    if arg_r.AtEnd():
        dollar0 = argv0
    else:
        dollar0 = arg_r.Peek()  # the script name, or the arg after -c

        # Copy quirky bash behavior.
        frame0 = state.DebugFrame(dollar0, 'main', no_str, state.LINE_ZERO, 0,
                                  0)
        debug_stack.append(frame0)

    # Copy quirky bash behavior.
    frame1 = state.DebugFrame(no_str, no_str, no_str, runtime.NO_SPID, 0, 0)
    debug_stack.append(frame1)

    arena = alloc.Arena()
    errfmt = ui.ErrorFormatter(arena)

    mem = state.Mem(dollar0, argv[arg_r.i + 1:], arena, debug_stack)
    state.InitMem(mem, posix.environ)
    builtin_funcs.Init(mem)

    procs = {}

    job_state = process.JobState()
    fd_state = process.FdState(errfmt, job_state)

    opt_hook = ShellOptHook(line_input)
    parse_opts, exec_opts, mutable_opts = state.MakeOpts(mem, opt_hook)
    # TODO: only MutableOpts needs mem, so it's not a true circular dep.
    mem.exec_opts = exec_opts  # circular dep

    if opts.show_options:  # special case: sh -o
        mutable_opts.ShowOptions([])
        return 0

    # Set these BEFORE processing flags, so they can be overridden.
    if lang == 'oil':
        mutable_opts.SetShoptOption('oil:all', True)

    builtin_pure.SetShellOpts(mutable_opts, opts.opt_changes,
                              opts.shopt_changes)
    aliases = {}  # feedback between runtime and parser

    oil_grammar = meta.LoadOilGrammar(loader)

    if opts.one_pass_parse and not exec_opts.noexec():
        raise args.UsageError('--one-pass-parse requires noexec (-n)')
    parse_ctx = parse_lib.ParseContext(arena, parse_opts, aliases, oil_grammar)
    parse_ctx.Init_OnePassParse(opts.one_pass_parse)

    # Three ParseContext instances SHARE aliases.
    comp_arena = alloc.Arena()
    comp_arena.PushSource(source.Unused('completion'))
    trail1 = parse_lib.Trail()
    # one_pass_parse needs to be turned on to complete inside backticks.  TODO:
    # fix the issue where ` gets erased because it's not part of
    # set_completer_delims().
    comp_ctx = parse_lib.ParseContext(comp_arena, parse_opts, aliases,
                                      oil_grammar)
    comp_ctx.Init_Trail(trail1)
    comp_ctx.Init_OnePassParse(True)

    hist_arena = alloc.Arena()
    hist_arena.PushSource(source.Unused('history'))
    trail2 = parse_lib.Trail()
    hist_ctx = parse_lib.ParseContext(hist_arena, parse_opts, aliases,
                                      oil_grammar)
    hist_ctx.Init_Trail(trail2)

    # Deps helps manages dependencies.  These dependencies are circular:
    # - ex and word_ev, arith_ev -- for command sub, arith sub
    # - arith_ev and word_ev -- for $(( ${a} )) and $x$(( 1 ))
    # - ex and builtins (which execute code, like eval)
    # - prompt_ev needs word_ev for $PS1, which needs prompt_ev for @P
    exec_deps = cmd_exec.Deps()
    exec_deps.mutable_opts = mutable_opts

    # TODO: In general, exec_deps are shared between the mutually recursive
    # evaluators.  Some of the four below are only shared between a builtin and
    # the Executor, so we could put them somewhere else.
    exec_deps.traps = {}
    exec_deps.trap_nodes = []  # TODO: Clear on fork() to avoid duplicates

    exec_deps.job_state = job_state
    exec_deps.waiter = process.Waiter(job_state, exec_opts)
    exec_deps.errfmt = errfmt

    my_pid = posix.getpid()

    debug_path = ''
    debug_dir = posix.environ.get('OSH_DEBUG_DIR')
    if opts.debug_file:  # --debug-file takes precedence over OSH_DEBUG_DIR
        debug_path = opts.debug_file
    elif debug_dir:
        debug_path = os_path.join(debug_dir, '%d-osh.log' % my_pid)

    if debug_path:
        # This will be created as an empty file if it doesn't exist, or it could be
        # a pipe.
        try:
            debug_f = util.DebugFile(fd_state.Open(debug_path, mode='w'))
        except OSError as e:
            ui.Stderr("osh: Couldn't open %r: %s", debug_path,
                      posix.strerror(e.errno))
            return 2
    else:
        debug_f = util.NullDebugFile()

    exec_deps.debug_f = debug_f

    # Not using datetime for dependency reasons.  TODO: maybe show the date at
    # the beginning of the log, and then only show time afterward?  To save
    # space, and make space for microseconds.  (datetime supports microseconds
    # but time.strftime doesn't).
    iso_stamp = time.strftime("%Y-%m-%d %H:%M:%S")
    debug_f.log('%s [%d] OSH started with argv %s', iso_stamp, my_pid, argv)
    if debug_path:
        debug_f.log('Writing logs to %r', debug_path)

    interp = posix.environ.get('OSH_HIJACK_SHEBANG', '')
    exec_deps.search_path = state.SearchPath(mem)
    exec_deps.ext_prog = process.ExternalProgram(interp, fd_state,
                                                 exec_deps.search_path, errfmt,
                                                 debug_f)

    splitter = split.SplitContext(mem)

    # split() builtin
    # TODO: Accept IFS as a named arg?  split('a b', IFS=' ')
    builtin_funcs.SetGlobalFunc(
        mem,
        'split',
        lambda s, ifs=None: splitter.SplitForWordEval(s, ifs=ifs))

    # glob() builtin
    # TODO: This is instantiation is duplicated in osh/word_eval.py
    globber = glob_.Globber(exec_opts)
    builtin_funcs.SetGlobalFunc(mem, 'glob', lambda s: globber.OilFuncCall(s))

    # This could just be OSH_DEBUG_STREAMS='debug crash' ?  That might be
    # stuffing too much into one, since a .json crash dump isn't a stream.
    crash_dump_dir = posix.environ.get('OSH_CRASH_DUMP_DIR', '')
    exec_deps.dumper = dev.CrashDumper(crash_dump_dir)

    if opts.xtrace_to_debug_file:
        trace_f = debug_f
    else:
        trace_f = util.DebugFile(sys.stderr)
    exec_deps.trace_f = trace_f

    comp_lookup = completion.Lookup()

    # Various Global State objects to work around readline interfaces
    compopt_state = completion.OptionState()
    comp_ui_state = comp_ui.State()
    prompt_state = comp_ui.PromptState()

    dir_stack = state.DirStack()

    new_var = builtin_assign.NewVar(mem, procs, errfmt)

    builtins = {  # Lookup
        builtin_i.echo: builtin_pure.Echo(exec_opts),
        builtin_i.printf: builtin_printf.Printf(mem, parse_ctx, errfmt),

        builtin_i.pushd: builtin_misc.Pushd(mem, dir_stack, errfmt),
        builtin_i.popd: builtin_misc.Popd(mem, dir_stack, errfmt),
        builtin_i.dirs: builtin_misc.Dirs(mem, dir_stack, errfmt),
        builtin_i.pwd: builtin_misc.Pwd(mem, errfmt),

        builtin_i.times: builtin_misc.Times(),
        builtin_i.read: builtin_misc.Read(splitter, mem),
        builtin_i.help: builtin_misc.Help(loader, errfmt),
        builtin_i.history: builtin_misc.History(line_input),

        # Completion (more added below)
        builtin_i.compopt: builtin_comp.CompOpt(compopt_state, errfmt),
        builtin_i.compadjust: builtin_comp.CompAdjust(mem),

        # test / [ differ by need_right_bracket
        builtin_i.test: builtin_bracket.Test(False, exec_opts, errfmt),
        builtin_i.bracket: builtin_bracket.Test(True, exec_opts, errfmt),

        # ShAssignment (which are pure)
        builtin_i.declare: new_var,
        builtin_i.typeset: new_var,
        builtin_i.local: new_var,

        builtin_i.export_: builtin_assign.Export(mem, errfmt),
        builtin_i.readonly: builtin_assign.Readonly(mem, errfmt),

        builtin_i.unset: builtin_assign.Unset(mem, procs, errfmt),
        builtin_i.shift: builtin_assign.Shift(mem),

        # Pure
        builtin_i.set: builtin_pure.Set(mutable_opts, mem),
        builtin_i.shopt: builtin_pure.Shopt(mutable_opts),

        builtin_i.alias: builtin_pure.Alias(aliases, errfmt),
        builtin_i.unalias: builtin_pure.UnAlias(aliases, errfmt),

        builtin_i.type: builtin_pure.Type(procs, aliases, exec_deps.search_path),
        builtin_i.hash: builtin_pure.Hash(exec_deps.search_path),
        builtin_i.getopts: builtin_pure.GetOpts(mem, errfmt),

        builtin_i.colon: builtin_pure.Boolean(0),  # a "special" builtin 
        builtin_i.true_: builtin_pure.Boolean(0),
        builtin_i.false_: builtin_pure.Boolean(1),

        # Process
        builtin_i.wait: builtin_process.Wait(exec_deps.waiter,
                                             exec_deps.job_state, mem, errfmt),
        builtin_i.jobs: builtin_process.Jobs(exec_deps.job_state),
        builtin_i.fg: builtin_process.Fg(exec_deps.job_state, exec_deps.waiter),
        builtin_i.bg: builtin_process.Bg(exec_deps.job_state),
        builtin_i.umask: builtin_process.Umask(),

        # Oil
        builtin_i.push: builtin_oil.Push(mem, errfmt),
        builtin_i.append: builtin_oil.Append(mem, errfmt),

        builtin_i.write: builtin_oil.Write(mem, errfmt),
        builtin_i.getline: builtin_oil.Getline(mem, errfmt),

        builtin_i.repr: builtin_oil.Repr(mem, errfmt),
        builtin_i.use: builtin_oil.Use(mem, errfmt),
        builtin_i.opts: builtin_oil.Opts(mem, errfmt),
    }

    arith_ev = sh_expr_eval.ArithEvaluator(mem, exec_opts, errfmt)
    bool_ev = sh_expr_eval.BoolEvaluator(mem, exec_opts, errfmt)
    expr_ev = expr_eval.OilEvaluator(mem, procs, errfmt)
    word_ev = word_eval.NormalWordEvaluator(mem, exec_opts, splitter, errfmt)
    ex = cmd_exec.Executor(mem, fd_state, procs, builtins, exec_opts,
                           parse_ctx, exec_deps)
    # PromptEvaluator rendering is needed in non-interactive shells for @P.
    prompt_ev = prompt.Evaluator(lang, parse_ctx, mem)
    tracer = dev.Tracer(parse_ctx, exec_opts, mutable_opts, mem, word_ev,
                        trace_f)

    # Wire up circular dependencies.
    vm.InitCircularDeps(arith_ev, bool_ev, expr_ev, word_ev, ex, prompt_ev,
                        tracer)

    spec_builder = builtin_comp.SpecBuilder(ex, parse_ctx, word_ev, splitter,
                                            comp_lookup)

    # Add some builtins that depend on the executor!
    complete_builtin = builtin_comp.Complete(spec_builder, comp_lookup)
    builtins[builtin_i.complete] = complete_builtin
    builtins[builtin_i.compgen] = builtin_comp.CompGen(spec_builder)
    builtins[builtin_i.cd] = builtin_misc.Cd(mem, dir_stack, ex, errfmt)
    builtins[builtin_i.json] = builtin_oil.Json(mem, ex, errfmt)

    sig_state = process.SignalState()
    sig_state.InitShell()

    builtins[builtin_i.trap] = builtin_process.Trap(sig_state, exec_deps.traps,
                                                    exec_deps.trap_nodes, ex,
                                                    errfmt)

    # History evaluation is a no-op if line_input is None.
    hist_ev = history.Evaluator(line_input, hist_ctx, debug_f)

    if opts.c is not None:
        arena.PushSource(source.CFlag())
        line_reader = reader.StringLineReader(opts.c, arena)
        if opts.i:  # -c and -i can be combined
            mutable_opts.set_interactive()

    elif opts.i:  # force interactive
        arena.PushSource(source.Stdin(' -i'))
        line_reader = py_reader.InteractiveLineReader(arena, prompt_ev,
                                                      hist_ev, line_input,
                                                      prompt_state)
        mutable_opts.set_interactive()

    else:
        script_name = arg_r.Peek()
        if script_name is None:
            if sys.stdin.isatty():
                arena.PushSource(source.Interactive())
                line_reader = py_reader.InteractiveLineReader(
                    arena, prompt_ev, hist_ev, line_input, prompt_state)
                mutable_opts.set_interactive()
            else:
                arena.PushSource(source.Stdin(''))
                line_reader = reader.FileLineReader(sys.stdin, arena)
        else:
            arena.PushSource(source.MainFile(script_name))
            try:
                f = fd_state.Open(script_name)
            except OSError as e:
                ui.Stderr("osh: Couldn't open %r: %s", script_name,
                          posix.strerror(e.errno))
                return 1
            line_reader = reader.FileLineReader(f, arena)

    # TODO: assert arena.NumSourcePaths() == 1
    # TODO: .rc file needs its own arena.
    c_parser = parse_ctx.MakeOshParser(line_reader)

    if exec_opts.interactive():
        # Calculate ~/.config/oil/oshrc or oilrc
        # Use ~/.config/oil to avoid cluttering the user's home directory.  Some
        # users may want to ln -s ~/.config/oil/oshrc ~/oshrc or ~/.oshrc.

        # https://unix.stackexchange.com/questions/24347/why-do-some-applications-use-config-appname-for-their-config-data-while-other
        home_dir = passwd.GetMyHomeDir()
        assert home_dir is not None
        rc_path = opts.rcfile or os_path.join(home_dir, '.config/oil',
                                              lang + 'rc')

        history_filename = os_path.join(home_dir, '.config/oil',
                                        'history_' + lang)

        if line_input:
            # NOTE: We're using a different WordEvaluator here.
            ev = word_eval.CompletionWordEvaluator(mem, exec_opts, splitter,
                                                   errfmt)

            ev.arith_ev = arith_ev
            ev.expr_ev = expr_ev
            ev.prompt_ev = prompt_ev
            ev.CheckCircularDeps()

            root_comp = completion.RootCompleter(ev, mem, comp_lookup,
                                                 compopt_state, comp_ui_state,
                                                 comp_ctx, debug_f)

            term_width = 0
            if opts.completion_display == 'nice':
                try:
                    term_width = libc.get_terminal_width()
                except IOError:  # stdin not a terminal
                    pass

            if term_width != 0:
                display = comp_ui.NiceDisplay(term_width, comp_ui_state,
                                              prompt_state, debug_f,
                                              line_input)
            else:
                display = comp_ui.MinimalDisplay(comp_ui_state, prompt_state,
                                                 debug_f)

            _InitReadline(line_input, history_filename, root_comp, display,
                          debug_f)
            _InitDefaultCompletions(ex, complete_builtin, comp_lookup)

        else:  # Without readline module
            display = comp_ui.MinimalDisplay(comp_ui_state, prompt_state,
                                             debug_f)

        sig_state.InitInteractiveShell(display)

        # NOTE: Call this AFTER _InitDefaultCompletions.
        try:
            SourceStartupFile(rc_path, lang, parse_ctx, ex)
        except util.UserExit as e:
            return e.status

        line_reader.Reset()  # After sourcing startup file, render $PS1

        prompt_plugin = prompt.UserPlugin(mem, parse_ctx, ex)
        try:
            status = main_loop.Interactive(opts, ex, c_parser, display,
                                           prompt_plugin, errfmt)
            if ex.MaybeRunExitTrap():
                status = ex.LastStatus()
        except util.UserExit as e:
            status = e.status
        return status

    nodes_out = [] if exec_opts.noexec() else None

    if nodes_out is None and opts.parser_mem_dump:
        raise args.UsageError('--parser-mem-dump can only be used with -n')

    _tlog('Execute(node)')
    try:
        status = main_loop.Batch(ex, c_parser, arena, nodes_out=nodes_out)
        if ex.MaybeRunExitTrap():
            status = ex.LastStatus()
    except util.UserExit as e:
        status = e.status

    # Only print nodes if the whole parse succeeded.
    if nodes_out is not None and status == 0:
        if opts.parser_mem_dump:  # only valid in -n mode
            # This might be superstition, but we want to let the value stabilize
            # after parsing.  bash -c 'cat /proc/$$/status' gives different results
            # with a sleep.
            time.sleep(0.001)
            input_path = '/proc/%d/status' % posix.getpid()
            with open(input_path) as f, open(opts.parser_mem_dump, 'w') as f2:
                contents = f.read()
                f2.write(contents)
                log('Wrote %s to %s (--parser-mem-dump)', input_path,
                    opts.parser_mem_dump)

        ui.PrintAst(nodes_out, opts)

    # NOTE: 'exit 1' is ControlFlow and gets here, but subshell/commandsub
    # don't because they call sys.exit().
    if opts.runtime_mem_dump:
        # This might be superstition, but we want to let the value stabilize
        # after parsing.  bash -c 'cat /proc/$$/status' gives different results
        # with a sleep.
        time.sleep(0.001)
        input_path = '/proc/%d/status' % posix.getpid()
        with open(input_path) as f, open(opts.runtime_mem_dump, 'w') as f2:
            contents = f.read()
            f2.write(contents)
            log('Wrote %s to %s (--runtime-mem-dump)', input_path,
                opts.runtime_mem_dump)

    # NOTE: We haven't closed the file opened with fd_state.Open
    return status