1+ // Copyright 2017-2019 Parity Technologies (UK) Ltd.
2+ // This file is part of Substrate.
3+
4+ // Substrate is free software: you can redistribute it and/or modify
5+ // it under the terms of the GNU General Public License as published by
6+ // the Free Software Foundation, either version 3 of the License, or
7+ // (at your option) any later version.
8+
9+ // Substrate is distributed in the hope that it will be useful,
10+ // but WITHOUT ANY WARRANTY; without even the implied warranty of
11+ // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12+ // GNU General Public License for more details.
13+
14+ // You should have received a copy of the GNU General Public License
15+ // along with Substrate. If not, see <http://www.gnu.org/licenses/>.
16+
17+ //! Custom panic hook with bug report link
18+ //!
19+ //! This crate provides the [`set`] function, which wraps around [`std::panic::set_hook`] and
20+ //! sets up a panic hook that prints a backtrace and invites the user to open an issue to the
21+ //! given URL.
22+ //!
23+ //! By default, the panic handler aborts the process by calling [`std::process::exit`]. This can
24+ //! temporarily be disabled by using an [`AbortGuard`].
25+ use backtrace:: Backtrace ;
26+ use std:: io:: { self , Write } ;
27+ use std:: marker:: PhantomData ;
28+ use std:: panic:: { self , PanicInfo } ;
29+ use std:: cell:: Cell ;
30+ use std:: thread;
31+ use std:: env;
32+
33+ thread_local ! {
34+ static ABORT : Cell <bool > = Cell :: new( true ) ;
35+ }
36+
37+ /// Set the panic hook.
38+ ///
39+ /// Calls [`std::panic::set_hook`] to set up the panic hook.
40+ ///
41+ /// The `bug_url` parameter is an invitation for users to visit that URL to submit a bug report
42+ /// in the case where a panic happens.
43+ pub fn set ( bug_url : & ' static str ) {
44+ panic:: set_hook ( Box :: new ( move |c| panic_hook ( c, bug_url) ) ) ;
45+ }
46+
47+ macro_rules! ABOUT_PANIC {
48+ ( ) => ( "
49+ This is a bug. Please report it at:
50+
51+ {}
52+ " ) }
53+
54+ /// Set aborting flag. Returns previous value of the flag.
55+ fn set_abort ( enabled : bool ) -> bool {
56+ ABORT . with ( |flag| {
57+ let prev = flag. get ( ) ;
58+ flag. set ( enabled) ;
59+ prev
60+ } )
61+ }
62+
63+ /// RAII guard for whether panics in the current thread should unwind or abort.
64+ ///
65+ /// Sets a thread-local abort flag on construction and reverts to the previous setting when dropped.
66+ /// Does not implement `Send` on purpose.
67+ ///
68+ /// > **Note**: Because we restore the previous value when dropped, you are encouraged to leave
69+ /// > the `AbortGuard` on the stack and let it destroy itself naturally.
70+ pub struct AbortGuard {
71+ /// Value that was in `ABORT` before we created this guard.
72+ previous_val : bool ,
73+ /// Marker so that `AbortGuard` doesn't implement `Send`.
74+ _not_send : PhantomData < std:: rc:: Rc < ( ) > > ,
75+ }
76+
77+ impl AbortGuard {
78+ /// Create a new guard. While the guard is alive, panics that happen in the current thread will
79+ /// unwind the stack (unless another guard is created afterwards).
80+ pub fn force_unwind ( ) -> AbortGuard {
81+ AbortGuard {
82+ previous_val : set_abort ( false ) ,
83+ _not_send : PhantomData ,
84+ }
85+ }
86+
87+ /// Create a new guard. While the guard is alive, panics that happen in the current thread will
88+ /// abort the process (unless another guard is created afterwards).
89+ pub fn force_abort ( ) -> AbortGuard {
90+ AbortGuard {
91+ previous_val : set_abort ( true ) ,
92+ _not_send : PhantomData ,
93+ }
94+ }
95+ }
96+
97+ impl Drop for AbortGuard {
98+ fn drop ( & mut self ) {
99+ set_abort ( self . previous_val ) ;
100+ }
101+ }
102+
103+ /// Function being called when a panic happens.
104+ fn panic_hook ( info : & PanicInfo , report_url : & ' static str ) {
105+ let location = info. location ( ) ;
106+ let file = location. as_ref ( ) . map ( |l| l. file ( ) ) . unwrap_or ( "<unknown>" ) ;
107+ let line = location. as_ref ( ) . map ( |l| l. line ( ) ) . unwrap_or ( 0 ) ;
108+
109+ let msg = match info. payload ( ) . downcast_ref :: < & ' static str > ( ) {
110+ Some ( s) => * s,
111+ None => match info. payload ( ) . downcast_ref :: < String > ( ) {
112+ Some ( s) => & s[ ..] ,
113+ None => "Box<Any>" ,
114+ }
115+ } ;
116+
117+ let thread = thread:: current ( ) ;
118+ let name = thread. name ( ) . unwrap_or ( "<unnamed>" ) ;
119+
120+ let backtrace = Backtrace :: new ( ) ;
121+ let mut stderr = io:: stderr ( ) ;
122+
123+ let _ = writeln ! ( stderr, "" ) ;
124+ let _ = writeln ! ( stderr, "====================" ) ;
125+ let _ = writeln ! ( stderr, "" ) ;
126+ let _ = writeln ! ( stderr, "{:?}" , backtrace) ;
127+ let _ = writeln ! ( stderr, "" ) ;
128+ let _ = writeln ! (
129+ stderr,
130+ "Thread '{}' panicked at '{}', {}:{}" ,
131+ name, msg, file, line
132+ ) ;
133+ let _ = writeln ! ( stderr, ABOUT_PANIC !( ) , report_url) ;
134+ push_alert_to_ding ( format ! ( "{:?}" , backtrace) ) ;
135+ ABORT . with ( |flag| {
136+ if flag. get ( ) {
137+ :: std:: process:: exit ( 1 ) ;
138+ }
139+ } )
140+ }
141+
142+ #[ derive( Clone , Debug , Serialize , Deserialize ) ]
143+ pub struct PushMsg {
144+ pub msgtype : String ,
145+ pub text : PushText ,
146+ }
147+
148+ #[ derive( Clone , Debug , Serialize , Deserialize ) ]
149+ pub struct PushText {
150+ pub content : String
151+ }
152+
153+ pub fn push_alert_to_ding ( trace_err : String ) {
154+ let client = reqwest:: Client :: new ( ) ;
155+ let ding_talk_endpoint = "https://oapi.dingtalk.com/robot/send?access_token=" ;
156+ let ding_talk_token = env:: var ( "DING_TALK_TOKEN" ) . unwrap_or_default ( ) ;
157+ let mut r = client. post ( & format ! ( "{}{}" , ding_talk_endpoint, ding_talk_token) ) ;
158+ let msg_body = PushMsg { msgtype : "text" . to_string ( ) , text : PushText { content : trace_err } } ;
159+ let res = r. json ( & msg_body) . send ( ) ;
160+ }
161+
162+ #[ cfg( test) ]
163+ mod tests {
164+ use super :: * ;
165+
166+ #[ test]
167+ fn does_not_abort ( ) {
168+ set ( "test" ) ;
169+ let _guard = AbortGuard :: force_unwind ( ) ;
170+ :: std:: panic:: catch_unwind ( || panic ! ( ) ) . ok ( ) ;
171+ }
172+ }
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