1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
use crate::frame_info::{GlobalFrameInfo, FRAME_INFO};
use crate::FrameInfo;
use backtrace::Backtrace;
use std::fmt;
use std::sync::Arc;
use wasmtime_environ::ir::TrapCode;
#[derive(Clone)]
pub struct Trap {
inner: Arc<TrapInner>,
}
struct TrapInner {
message: String,
wasm_trace: Vec<FrameInfo>,
native_trace: Backtrace,
}
fn _assert_trap_is_sync_and_send(t: &Trap) -> (&dyn Sync, &dyn Send) {
(t, t)
}
impl Trap {
pub fn new<I: Into<String>>(message: I) -> Self {
let info = FRAME_INFO.read().unwrap();
Trap::new_with_trace(&info, None, message.into(), Backtrace::new_unresolved())
}
pub(crate) fn from_jit(jit: wasmtime_runtime::Trap) -> Self {
let info = FRAME_INFO.read().unwrap();
match jit {
wasmtime_runtime::Trap::User(error) => {
*error
.downcast()
.expect("only `Trap` user errors are supported")
}
wasmtime_runtime::Trap::Jit {
pc,
backtrace,
maybe_interrupted,
} => {
let mut code = info
.lookup_trap_info(pc)
.map(|info| info.trap_code)
.unwrap_or(TrapCode::StackOverflow);
if maybe_interrupted && code == TrapCode::StackOverflow {
code = TrapCode::Interrupt;
}
Trap::new_wasm(&info, Some(pc), code, backtrace)
}
wasmtime_runtime::Trap::Wasm {
trap_code,
backtrace,
} => Trap::new_wasm(&info, None, trap_code, backtrace),
wasmtime_runtime::Trap::OOM { backtrace } => {
Trap::new_with_trace(&info, None, "out of memory".to_string(), backtrace)
}
}
}
fn new_wasm(
info: &GlobalFrameInfo,
trap_pc: Option<usize>,
code: TrapCode,
backtrace: Backtrace,
) -> Self {
use wasmtime_environ::ir::TrapCode::*;
let desc = match code {
StackOverflow => "call stack exhausted",
HeapOutOfBounds => "out of bounds memory access",
TableOutOfBounds => "undefined element: out of bounds table access",
OutOfBounds => "out of bounds",
IndirectCallToNull => "uninitialized element",
BadSignature => "indirect call type mismatch",
IntegerOverflow => "integer overflow",
IntegerDivisionByZero => "integer divide by zero",
BadConversionToInteger => "invalid conversion to integer",
UnreachableCodeReached => "unreachable",
Interrupt => "interrupt",
User(_) => unreachable!(),
};
let msg = format!("wasm trap: {}", desc);
Trap::new_with_trace(info, trap_pc, msg, backtrace)
}
fn new_with_trace(
info: &GlobalFrameInfo,
trap_pc: Option<usize>,
message: String,
native_trace: Backtrace,
) -> Self {
let mut wasm_trace = Vec::new();
for frame in native_trace.frames() {
let pc = frame.ip() as usize;
if pc == 0 {
continue;
}
let pc_to_lookup = if Some(pc) == trap_pc { pc } else { pc - 1 };
if let Some(info) = info.lookup_frame_info(pc_to_lookup) {
wasm_trace.push(info);
}
}
Trap {
inner: Arc::new(TrapInner {
message,
wasm_trace,
native_trace,
}),
}
}
pub fn message(&self) -> &str {
&self.inner.message
}
pub fn trace(&self) -> &[FrameInfo] {
&self.inner.wasm_trace
}
}
impl fmt::Debug for Trap {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Trap")
.field("message", &self.inner.message)
.field("wasm_trace", &self.inner.wasm_trace)
.field("native_trace", &self.inner.native_trace)
.finish()
}
}
impl fmt::Display for Trap {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.inner.message)?;
let trace = self.trace();
if trace.is_empty() {
return Ok(());
}
writeln!(f, "\nwasm backtrace:")?;
for (i, frame) in self.trace().iter().enumerate() {
let name = frame.module_name().unwrap_or("<unknown>");
write!(f, " {}: {:#6x} - {}!", i, frame.module_offset(), name)?;
match frame.func_name() {
Some(name) => match rustc_demangle::try_demangle(name) {
Ok(name) => write!(f, "{}", name)?,
Err(_) => write!(f, "{}", name)?,
},
None => write!(f, "<wasm function {}>", frame.func_index())?,
}
writeln!(f, "")?;
}
Ok(())
}
}
impl std::error::Error for Trap {}