rust/src/libstd/panicking.rs
2015-06-17 09:06:59 -07:00

70 lines
2.3 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.
use prelude::v1::*;
use io::prelude::*;
use any::Any;
use cell::RefCell;
use rt::{backtrace, unwind};
use sys::stdio::Stderr;
use sys_common::thread_info;
thread_local! {
pub static LOCAL_STDERR: RefCell<Option<Box<Write + Send>>> = {
RefCell::new(None)
}
}
pub fn on_panic(obj: &(Any+Send), file: &'static str, line: u32) {
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 = match Stderr::new() {
Ok(err) => err,
_ => return,
};
let thread = thread_info::current_thread();
let name = thread.as_ref().and_then(|t| t.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);
}
}