Panic hook (#379)

* Panic hook

* Abort on panic in release

polkadot/cli/Cargo.toml

@@ -6,6 +6,7 @@ description = "Polkadot node implementation in Rust."
 
 [dependencies]
 clap = { version = "2.27", features = ["yaml"] }
+backtrace = "0.3"
 env_logger = "0.4"
 error-chain = "0.12"
 log = "0.3"

polkadot/cli/src/lib.rs

@@ -33,6 +33,7 @@ extern crate parking_lot;
 extern crate serde;
 extern crate serde_json;
 extern crate names;
+extern crate backtrace;
 
 extern crate substrate_client as client;
 extern crate substrate_network as network;
@@ -66,6 +67,7 @@ extern crate log;
 pub mod error;
 mod informant;
 mod chain_spec;
+mod panic_hook;
 
 pub use chain_spec::ChainSpec;
 pub use client::error::Error as ClientError;
@@ -166,6 +168,8 @@ pub fn run<I, T, W>(args: I, worker: W) -> error::Result<()> where
 	T: Into<std::ffi::OsString> + Clone,
 	W: Worker,
 {
+	panic_hook::set();
+
 	let yaml = load_yaml!("./cli.yml");
 	let matches = match clap::App::from_yaml(yaml).version(&(crate_version!().to_owned() + "\n")[..]).get_matches_from_safe(args) {
 		Ok(m) => m,

polkadot/cli/src/panic_hook.rs

@@ -0,0 +1,68 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Custom panic hook with bug report link
+
+use backtrace::Backtrace;
+use std::io::{self, Write};
+use std::panic::{self, PanicInfo};
+use std::thread;
+
+/// Set the panic hook
+pub fn set() {
+	panic::set_hook(Box::new(panic_hook));
+}
+
+static ABOUT_PANIC: &str = "
+This is a bug. Please report it at:
+
+    https://github.com/paritytech/polkadot/issues/new
+";
+
+fn panic_hook(info: &PanicInfo) {
+	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, "{:?}", backtrace);
+	let _ = writeln!(stderr, "");
+	let _ = writeln!(
+		stderr,
+		"Thread '{}' panicked at '{}', {}:{}",
+		name, msg, file, line
+	);
+
+	let _ = writeln!(stderr, "{}", ABOUT_PANIC);
+}
+