7828c3dd28
https://github.com/rust-lang/rfcs/pull/221 The current terminology of "task failure" often causes problems when writing or speaking about code. You often want to talk about the possibility of an operation that returns a Result "failing", but cannot because of the ambiguity with task failure. Instead, you have to speak of "the failing case" or "when the operation does not succeed" or other circumlocutions. Likewise, we use a "Failure" header in rustdoc to describe when operations may fail the task, but it would often be helpful to separate out a section describing the "Err-producing" case. We have been steadily moving away from task failure and toward Result as an error-handling mechanism, so we should optimize our terminology accordingly: Result-producing functions should be easy to describe. To update your code, rename any call to `fail!` to `panic!` instead. Assuming you have not created your own macro named `panic!`, this will work on UNIX based systems: grep -lZR 'fail!' . | xargs -0 -l sed -i -e 's/fail!/panic!/g' You can of course also do this by hand. [breaking-change]
105 lines
3.6 KiB
Rust
105 lines
3.6 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![experimental]
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use alloc::boxed::Box;
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use any::{Any, AnyRefExt};
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use fmt;
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use io::{Writer, IoResult};
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use kinds::Send;
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use option::{Some, None};
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use result::Ok;
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use rt::backtrace;
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use rt::{Stderr, Stdio};
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use rustrt::local::Local;
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use rustrt::task::Task;
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use str::Str;
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use string::String;
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// Defined in this module instead of io::stdio so that the unwinding
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local_data_key!(pub local_stderr: Box<Writer + Send>)
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impl Writer for Stdio {
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fn write(&mut self, bytes: &[u8]) -> IoResult<()> {
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fn fmt_write<F: fmt::FormatWriter>(f: &mut F, bytes: &[u8]) {
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let _ = f.write(bytes);
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}
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fmt_write(self, bytes);
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Ok(())
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}
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}
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pub fn on_fail(obj: &Any + Send, file: &'static str, line: uint) {
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let msg = match obj.downcast_ref::<&'static str>() {
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Some(s) => *s,
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None => match obj.downcast_ref::<String>() {
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Some(s) => s.as_slice(),
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None => "Box<Any>",
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}
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};
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let mut err = Stderr;
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// It is assumed that all reasonable rust code will have a local task at
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// all times. This means that this `exists` will return true almost all of
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// the time. There are border cases, however, when the runtime has
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// *almost* set up the local task, but hasn't quite gotten there yet. In
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// order to get some better diagnostics, we print on panic and
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// immediately abort the whole process if there is no local task
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// available.
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if !Local::exists(None::<Task>) {
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let _ = writeln!(&mut err, "panicked at '{}', {}:{}", msg, file, line);
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if backtrace::log_enabled() {
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let _ = backtrace::write(&mut err);
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} else {
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let _ = writeln!(&mut err, "run with `RUST_BACKTRACE=1` to \
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see a backtrace");
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}
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return
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}
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// Peel the name out of local task so we can print it. We've got to be sure
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// that the local task is in TLS while we're printing as I/O may occur.
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let (name, unwinding) = {
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let mut t = Local::borrow(None::<Task>);
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(t.name.take(), t.unwinder.unwinding())
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};
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{
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let n = name.as_ref().map(|n| n.as_slice()).unwrap_or("<unnamed>");
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match local_stderr.replace(None) {
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Some(mut stderr) => {
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// FIXME: what to do when the task printing panics?
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let _ = writeln!(stderr,
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"task '{}' panicked at '{}', {}:{}\n",
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n, msg, file, line);
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if backtrace::log_enabled() {
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let _ = backtrace::write(&mut *stderr);
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}
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local_stderr.replace(Some(stderr));
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}
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None => {
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let _ = writeln!(&mut err, "task '{}' panicked at '{}', {}:{}",
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n, msg, file, line);
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if backtrace::log_enabled() {
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let _ = backtrace::write(&mut err);
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}
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}
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}
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// If this is a double panic, make sure that we printed a backtrace
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// for this panic.
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if unwinding && !backtrace::log_enabled() {
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let _ = backtrace::write(&mut err);
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}
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}
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Local::borrow(None::<Task>).name = name;
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}
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