rust/src/libstd/panicking.rs
2015-02-18 17:36:03 -05:00

77 lines
2.4 KiB
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![unstable(feature = "std_misc")]
use prelude::v1::*;
use any::Any;
use cell::RefCell;
use old_io::IoResult;
use rt::{backtrace, unwind};
use rt::util::{Stderr, Stdio};
use thread;
// Defined in this module instead of old_io::stdio so that the unwinding
thread_local! {
pub static LOCAL_STDERR: RefCell<Option<Box<Writer + Send>>> = {
RefCell::new(None)
}
}
impl Writer for Stdio {
fn write_all(&mut self, bytes: &[u8]) -> IoResult<()> {
let _ = self.write_bytes(bytes);
Ok(())
}
}
pub fn on_panic(obj: &(Any+Send), file: &'static str, line: uint) {
let msg = match obj.downcast_ref::<&'static str>() {
Some(s) => *s,
None => match obj.downcast_ref::<String>() {
Some(s) => &s[..],
None => "Box<Any>",
}
};
let mut err = Stderr;
let thread = thread::current();
let name = thread.name().unwrap_or("<unnamed>");
let prev = LOCAL_STDERR.with(|s| s.borrow_mut().take());
match prev {
Some(mut stderr) => {
// FIXME: what to do when the thread printing panics?
let _ = writeln!(stderr,
"thread '{}' panicked at '{}', {}:{}\n",
name, msg, file, line);
if backtrace::log_enabled() {
let _ = backtrace::write(&mut *stderr);
}
let mut s = Some(stderr);
LOCAL_STDERR.with(|slot| {
*slot.borrow_mut() = s.take();
});
}
None => {
let _ = writeln!(&mut err, "thread '{}' panicked at '{}', {}:{}",
name, msg, file, line);
if backtrace::log_enabled() {
let _ = backtrace::write(&mut err);
}
}
}
// If this is a double panic, make sure that we printed a backtrace
// for this panic.
if unwind::panicking() && !backtrace::log_enabled() {
let _ = backtrace::write(&mut err);
}
}