use backtrace::Backtrace;
use std::io::{self, Write};
use std::marker::PhantomData;
use std::panic::{self, PanicInfo};
use std::cell::Cell;
use std::thread;
thread_local! {
static ON_PANIC: Cell<OnPanic> = Cell::new(OnPanic::Abort);
}
#[derive(Debug, Clone, Copy, PartialEq)]
enum OnPanic {
Abort,
Unwind,
NeverAbort,
}
pub fn set(bug_url: &str, version: &str) {
panic::set_hook(Box::new({
let version = version.to_string();
let bug_url = bug_url.to_string();
move |c| {
panic_hook(c, &bug_url, &version)
}
}));
}
macro_rules! ABOUT_PANIC {
() => ("
This is a bug. Please report it at:
{}
")}
fn set_abort(on_panic: OnPanic) -> OnPanic {
ON_PANIC.with(|val| {
let prev = val.get();
match prev {
OnPanic::Abort | OnPanic::Unwind => val.set(on_panic),
OnPanic::NeverAbort => (),
}
prev
})
}
pub struct AbortGuard {
previous_val: OnPanic,
_not_send: PhantomData<std::rc::Rc<()>>
}
impl AbortGuard {
pub fn force_unwind() -> AbortGuard {
AbortGuard {
previous_val: set_abort(OnPanic::Unwind),
_not_send: PhantomData
}
}
pub fn force_abort() -> AbortGuard {
AbortGuard {
previous_val: set_abort(OnPanic::Abort),
_not_send: PhantomData
}
}
pub fn never_abort() -> AbortGuard {
AbortGuard {
previous_val: set_abort(OnPanic::NeverAbort),
_not_send: PhantomData
}
}
}
impl Drop for AbortGuard {
fn drop(&mut self) {
set_abort(self.previous_val);
}
}
fn panic_hook(info: &PanicInfo, report_url: &str, version: &str) {
let location = info.location();
let file = location.as_ref().map(|l| l.file()).unwrap_or("<unknown>");
let line = location.as_ref().map(|l| l.line()).unwrap_or(0);
let msg = match info.payload().downcast_ref::<&'static str>() {
Some(s) => *s,
None => match info.payload().downcast_ref::<String>() {
Some(s) => &s[..],
None => "Box<Any>",
}
};
let thread = thread::current();
let name = thread.name().unwrap_or("<unnamed>");
let backtrace = Backtrace::new();
let mut stderr = io::stderr();
let _ = writeln!(stderr, "");
let _ = writeln!(stderr, "====================");
let _ = writeln!(stderr, "");
let _ = writeln!(stderr, "Version: {}", version);
let _ = writeln!(stderr, "");
let _ = writeln!(stderr, "{:?}", backtrace);
let _ = writeln!(stderr, "");
let _ = writeln!(
stderr,
"Thread '{}' panicked at '{}', {}:{}",
name, msg, file, line
);
let _ = writeln!(stderr, ABOUT_PANIC!(), report_url);
ON_PANIC.with(|val| {
if val.get() == OnPanic::Abort {
::std::process::exit(1);
}
})
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn does_not_abort() {
set("test", "1.2.3");
let _guard = AbortGuard::force_unwind();
::std::panic::catch_unwind(|| panic!()).ok();
}
#[test]
fn does_not_abort_after_never_abort() {
set("test", "1.2.3");
let _guard = AbortGuard::never_abort();
let _guard = AbortGuard::force_abort();
std::panic::catch_unwind(|| panic!()).ok();
}
}