https://github.com/JuliaLang/julia
Revision 85164250068bdccf7d22a7fea0d0a3fc55178d8d authored by Jameson Nash on 17 November 2015, 21:09:27 UTC, committed by Jameson Nash on 17 November 2015, 22:25:08 UTC
Instead of making task_done_hook aware of the REPL specifically,
this gives clients (such as the REPL) the ability to register a
handler for any unhandled exception.

In reality, the only unhandled exceptions are those that occur
when trying to run task_done_hook or early on the root task.
Accordingly, the most like error is InterruptException,
but not exclusively.

This approach allows the REPL to print an error and return to a prompt,
even when the Task state of eval_user_input is too inconsistent or
unknown to be called directly.

If the last-chance exception handler returns or throws an error,
that that error is then considered to be finally fatal.
The return value when setting the exception handler allows the user
to chain and reset the handler.
1 parent 4a919e8
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Tip revision: 85164250068bdccf7d22a7fea0d0a3fc55178d8d authored by Jameson Nash on 17 November 2015, 21:09:27 UTC
alternative structured approach to replace the REPL InterruptException hack
Tip revision: 8516425
client.jl
# This file is a part of Julia. License is MIT: http://julialang.org/license

## client.jl - frontend handling command line options, environment setup,
##             and REPL

const ARGS = UTF8String[]

const text_colors = AnyDict(
    :black   => "\033[1m\033[30m",
    :red     => "\033[1m\033[31m",
    :green   => "\033[1m\033[32m",
    :yellow  => "\033[1m\033[33m",
    :blue    => "\033[1m\033[34m",
    :magenta => "\033[1m\033[35m",
    :cyan    => "\033[1m\033[36m",
    :white   => "\033[1m\033[37m",
    :normal  => "\033[0m",
    :bold    => "\033[1m",
)

have_color = false
default_color_warn = :red
default_color_info = :blue
@unix_only default_color_input = :bold
@unix_only default_color_answer = :bold
@windows_only default_color_input = :normal
@windows_only default_color_answer = :normal
color_normal = text_colors[:normal]

function repl_color(key, default)
    c = symbol(get(ENV, key, ""))
    haskey(text_colors, c) ? c : default
end

warn_color()   = repl_color("JULIA_WARN_COLOR", default_color_warn)
info_color()   = repl_color("JULIA_INFO_COLOR", default_color_info)
input_color()  = text_colors[repl_color("JULIA_INPUT_COLOR", default_color_input)]
answer_color() = text_colors[repl_color("JULIA_ANSWER_COLOR", default_color_answer)]

exit(n) = ccall(:jl_exit, Void, (Int32,), n)
exit() = exit(0)
quit() = exit()

function repl_cmd(cmd, out)
    shell = shell_split(get(ENV,"JULIA_SHELL",get(ENV,"SHELL","/bin/sh")))
    # Note that we can't support the fish shell due to its lack of subshells
    #   See this for details: https://github.com/JuliaLang/julia/issues/4918
    if Base.basename(shell[1]) == "fish"
        warn_once("cannot use the fish shell, defaulting to /bin/sh\
         set the JULIA_SHELL environment variable to silence this warning")
        shell = "/bin/sh"
    end

    if isempty(cmd.exec)
        throw(ArgumentError("no cmd to execute"))
    elseif cmd.exec[1] == "cd"
        new_oldpwd = pwd()
        if length(cmd.exec) > 2
            throw(ArgumentError("cd method only takes one argument"))
        elseif length(cmd.exec) == 2
            dir = cmd.exec[2]
            if dir == "-"
                if !haskey(ENV, "OLDPWD")
                    error("cd: OLDPWD not set")
                end
                cd(ENV["OLDPWD"])
            else
                cd(@windows? dir : readchomp(`$shell -c "echo $(shell_escape(dir))"`))
            end
        else
            cd()
        end
        ENV["OLDPWD"] = new_oldpwd
        println(out, pwd())
    else
        run(ignorestatus(@windows? cmd : (isa(STDIN, TTY) ? `$shell -i -c "($(shell_escape(cmd))) && true"` : `$shell -c "($(shell_escape(cmd))) && true"`)))
    end
    nothing
end

display_error(er) = display_error(er, [])
function display_error(er, bt)
    with_output_color(:red, STDERR) do io
        print(io, "ERROR: ")
        showerror(io, er, bt)
        println(io)
    end
end

function eval_user_input(ast::ANY, show_value)
    errcount, lasterr, bt = 0, (), nothing
    while true
        try
            if have_color
                print(color_normal)
            end
            if errcount > 0
                display_error(lasterr,bt)
                errcount, lasterr = 0, ()
            else
                ast = expand(ast)
                value = eval(Main,ast)
                eval(Main, :(ans = $(Expr(:quote, value))))
                if !is(value,nothing) && show_value
                    if have_color
                        print(answer_color())
                    end
                    try display(value)
                    catch err
                        println(STDERR, "Evaluation succeeded, but an error occurred while showing value of type ", typeof(value), ":")
                        rethrow(err)
                    end
                    println()
                end
            end
            break
        catch err
            if errcount > 0
                println(STDERR, "SYSTEM: show(lasterr) caused an error")
            end
            errcount, lasterr = errcount+1, err
            if errcount > 2
                println(STDERR, "WARNING: it is likely that something important is broken, and Julia will not be able to continue normally")
                break
            end
            bt = catch_backtrace()
        end
    end
    isa(STDIN,TTY) && println()
end

syntax_deprecation_warnings(warn::Bool) =
    ccall(:jl_parse_depwarn, Cint, (Cint,), warn) == 1

function syntax_deprecation_warnings(f::Function, warn::Bool)
    prev = syntax_deprecation_warnings(warn)
    try
        f()
    finally
        syntax_deprecation_warnings(prev)
    end
end

function parse_input_line(s::ByteString)
    # (expr, pos) = parse(s, 1)
    # (ex, pos) = ccall(:jl_parse_string, Any,
    #                   (Ptr{UInt8},Csize_t,Int32,Int32),
    #                   s, sizeof(s), pos-1, 1)
    # if !is(ex,())
    #     throw(ParseError("extra input after end of expression"))
    # end
    # expr
    ccall(:jl_parse_input_line, Any, (Ptr{UInt8}, Csize_t), s, sizeof(s))
end
parse_input_line(s::AbstractString) = parse_input_line(bytestring(s))

function parse_input_line(io::IO)
    s = ""
    while !eof(io)
        s = s*readline(io)
        e = parse_input_line(s)
        if !(isa(e,Expr) && e.head === :incomplete)
            return e
        end
    end
end

# detect the reason which caused an :incomplete expression
# from the error message
# NOTE: the error messages are defined in src/julia-parser.scm
incomplete_tag(ex) = :none
function incomplete_tag(ex::Expr)
    Meta.isexpr(ex, :incomplete) || return :none
    msg = ex.args[1]
    contains(msg, "string") && return :string
    contains(msg, "comment") && return :comment
    contains(msg, "requires end") && return :block
    contains(msg, "\"`\"") && return :cmd
    contains(msg, "character") && return :char
    return :other
end

# try to include() a file, ignoring if not found
try_include(path::AbstractString) = isfile(path) && include(path)

# initialize the local proc network address / port
function init_bind_addr()
    opts = JLOptions()
    if opts.bindto != C_NULL
        bind_to = split(bytestring(opts.bindto), ":")
        bind_addr = string(parseip(bind_to[1]))
        if length(bind_to) > 1
            bind_port = parse(Int,bind_to[2])
        else
            bind_port = 0
        end
    else
        bind_port = 0
        try
            bind_addr = string(getipaddr())
        catch
            # All networking is unavailable, initialize bind_addr to the loopback address
            # Will cause an exception to be raised only when used.
            bind_addr = "127.0.0.1"
        end
    end
    global LPROC
    LPROC.bind_addr = bind_addr
    LPROC.bind_port = UInt16(bind_port)
end

function process_options(opts::JLOptions, args::Vector{UTF8String})
    if !isempty(args)
        arg = first(args)
        idxs = find(x -> x == "--", args)
        if length(idxs) > 1
            println(STDERR, "julia: redundant option terminator `--`")
            exit(1)
        end
        deleteat!(ARGS, idxs)
    end
    repl                  = true
    startup               = (opts.startupfile != 2)
    history_file          = (opts.historyfile != 0)
    quiet                 = (opts.quiet != 0)
    color_set             = (opts.color != 0)
    global have_color     = (opts.color == 1)
    global is_interactive = (opts.isinteractive != 0)
    while true
        # load ~/.juliarc file
        startup && load_juliarc()

        # startup worker
        if opts.worker != 0
            start_worker() # does not return
        end
        # add processors
        if opts.nprocs > 0
            addprocs(opts.nprocs)
        end
        # load processes from machine file
        if opts.machinefile != C_NULL
            addprocs(load_machine_file(bytestring(opts.machinefile)))
        end
        # load file immediately on all processors
        if opts.load != C_NULL
            @sync for p in procs()
                @async remotecall_fetch(include, p, bytestring(opts.load))
            end
        end
        # eval expression
        if opts.eval != C_NULL
            repl = false
            eval(Main, parse_input_line(bytestring(opts.eval)))
            break
        end
        # eval expression and show result
        if opts.print != C_NULL
            repl = false
            show(eval(Main, parse_input_line(bytestring(opts.print))))
            println()
            break
        end
        # eval expression but don't disable interactive mode
        if opts.postboot != C_NULL
            eval(Main, parse_input_line(bytestring(opts.postboot)))
        end
        # load file
        if !isempty(args) && !isempty(args[1])
            # program
            repl = false
            # remove filename from ARGS
            shift!(ARGS)
            if !is_interactive
                ccall(:jl_exit_on_sigint, Void, (Cint,), 1)
            end
            include(args[1])
        end
        break
    end
    repl |= is_interactive
    return (quiet,repl,startup,color_set,history_file)
end

const roottask = current_task()

is_interactive = false
isinteractive() = (is_interactive::Bool)

const LOAD_PATH = ByteString[]
const LOAD_CACHE_PATH = ByteString[]
function init_load_path()
    vers = "v$(VERSION.major).$(VERSION.minor)"
    if haskey(ENV,"JULIA_LOAD_PATH")
        prepend!(LOAD_PATH, split(ENV["JULIA_LOAD_PATH"], @windows? ';' : ':'))
    end
    push!(LOAD_PATH,abspath(JULIA_HOME,"..","local","share","julia","site",vers))
    push!(LOAD_PATH,abspath(JULIA_HOME,"..","share","julia","site",vers))
    push!(LOAD_CACHE_PATH,abspath(Pkg.Dir._pkgroot(),"lib",vers))
    push!(LOAD_CACHE_PATH,abspath(JULIA_HOME,"..","usr","lib","julia")) #TODO: fixme
end

function load_juliarc()
    # If the user built us with a specific Base.SYSCONFDIR, check that location first for a juliarc.jl file
    #   If it is not found, then continue on to the relative path based on JULIA_HOME
    if !isempty(Base.SYSCONFDIR) && isfile(joinpath(JULIA_HOME,Base.SYSCONFDIR,"julia","juliarc.jl"))
        include(abspath(JULIA_HOME,Base.SYSCONFDIR,"julia","juliarc.jl"))
    else
        try_include(abspath(JULIA_HOME,"..","etc","julia","juliarc.jl"))
    end
    try_include(abspath(homedir(),".juliarc.jl"))
end

function load_machine_file(path::AbstractString)
    machines = []
    for line in split(readall(path),'\n'; keep=false)
        s = map!(strip, split(line,'*'; keep=false))
        if length(s) > 1
            cnt = isnumber(s[1]) ? parse(Int,s[1]) : symbol(s[1])
            push!(machines,(s[2], cnt))
        else
            push!(machines,line)
        end
    end
    return machines
end

function early_init()
    global const JULIA_HOME = ccall(:jl_get_julia_home, Any, ())
    # make sure OpenBLAS does not set CPU affinity (#1070, #9639)
    ENV["OPENBLAS_MAIN_FREE"] = get(ENV, "OPENBLAS_MAIN_FREE",
                                    get(ENV, "GOTOBLAS_MAIN_FREE", "1"))
    Sys.init_sysinfo()
    if CPU_CORES > 8 && !("OPENBLAS_NUM_THREADS" in keys(ENV)) && !("OMP_NUM_THREADS" in keys(ENV))
        # Prevent openblas from starting too many threads, unless/until specifically requested
        ENV["OPENBLAS_NUM_THREADS"] = 8
    end
end

function init_parallel()
    start_gc_msgs_task()
    atexit(terminate_all_workers)

    init_bind_addr()

    # start in "head node" mode, if worker, will override later.
    global PGRP
    global LPROC
    LPROC.id = 1
    assert(isempty(PGRP.workers))
    register_worker(LPROC)
end

import .Terminals
import .REPL

const repl_hooks = []

atreplinit(f::Function) = (unshift!(repl_hooks, f); nothing)

function _atreplinit(repl)
    for f in repl_hooks
        try
            f(repl)
        catch err
            show(STDERR, err)
            println(STDERR)
        end
    end
end

function _start()
    empty!(ARGS)
    append!(ARGS, Core.ARGS)
    opts = JLOptions()
    try
        (quiet,repl,startup,color_set,history_file) = process_options(opts,copy(ARGS))

        local term
        global active_repl
        global active_repl_backend
        if repl
            if !isa(STDIN,TTY)
                global is_interactive |= !isa(STDIN,Union{File,IOStream})
                color_set || (global have_color = false)
            else
                term = Terminals.TTYTerminal(get(ENV,"TERM",@windows? "" : "dumb"),STDIN,STDOUT,STDERR)
                global is_interactive = true
                color_set || (global have_color = Terminals.hascolor(term))
                quiet || REPL.banner(term,term)
                if term.term_type == "dumb"
                    active_repl = REPL.BasicREPL(term)
                    quiet || warn("Terminal not fully functional")
                else
                    active_repl = REPL.LineEditREPL(term, true)
                    active_repl.history_file = history_file
                    active_repl.hascolor = have_color
                end
                # Make sure any displays pushed in .juliarc.jl ends up above the
                # REPLDisplay
                pushdisplay(REPL.REPLDisplay(active_repl))
            end
        end

        if repl
            if !isa(STDIN,TTY)
                # note: currently IOStream is used for file STDIN
                if isa(STDIN,File) || isa(STDIN,IOStream)
                    # reading from a file, behave like include
                    eval(Main,parse_input_line(readall(STDIN)))
                else
                    # otherwise behave repl-like
                    while !eof(STDIN)
                        eval_user_input(parse_input_line(STDIN), true)
                    end
                end
            else
                _atreplinit(active_repl)
                REPL.run_repl(active_repl, backend->(global active_repl_backend = backend))
            end
        end
    catch err
        display_error(err,catch_backtrace())
        exit(1)
    end
    if is_interactive && have_color
        print(color_normal)
    end
end

const atexit_hooks = []

atexit(f::Function) = (unshift!(atexit_hooks, f); nothing)

function _atexit()
    for f in atexit_hooks
        try
            f()
        catch err
            show(STDERR, err)
            println(STDERR)
        end
    end
end
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