wasmer_types/
trapcode.rs

1// This file contains code from external sources.
2// Attributions: https://github.com/wasmerio/wasmer/blob/main/docs/ATTRIBUTIONS.md
3
4//! Trap codes describing the reason for a trap.
5
6use core::fmt::{self, Display, Formatter};
7use core::str::FromStr;
8use rkyv::{Archive, Deserialize as RkyvDeserialize, Serialize as RkyvSerialize};
9#[cfg(feature = "enable-serde")]
10use serde::{Deserialize, Serialize};
11use thiserror::Error;
12
13/// A trap code describing the reason for a trap.
14///
15/// All trap instructions have an explicit trap code.
16#[derive(
17    Clone, Copy, PartialEq, Eq, Debug, Hash, Error, RkyvSerialize, RkyvDeserialize, Archive,
18)]
19#[cfg_attr(feature = "enable-serde", derive(Serialize, Deserialize))]
20#[cfg_attr(feature = "artifact-size", derive(loupe::MemoryUsage))]
21#[rkyv(derive(Debug), compare(PartialEq))]
22#[repr(u32)]
23pub enum TrapCode {
24    /// The current stack space was exhausted.
25    ///
26    /// On some platforms, a stack overflow may also be indicated by a segmentation fault from the
27    /// stack guard page.
28    StackOverflow = 0,
29
30    /// A `heap_addr` instruction detected an out-of-bounds error.
31    ///
32    /// Note that not all out-of-bounds heap accesses are reported this way;
33    /// some are detected by a segmentation fault on the heap unmapped or
34    /// offset-guard pages.
35    HeapAccessOutOfBounds = 1,
36
37    /// A `heap_addr` instruction was misaligned.
38    HeapMisaligned = 2,
39
40    /// A `table_addr` instruction detected an out-of-bounds error.
41    TableAccessOutOfBounds = 3,
42
43    /// Indirect call to a null table entry.
44    IndirectCallToNull = 4,
45
46    /// Signature mismatch on indirect call.
47    BadSignature = 5,
48
49    /// An integer arithmetic operation caused an overflow.
50    IntegerOverflow = 6,
51
52    /// An integer division by zero.
53    IntegerDivisionByZero = 7,
54
55    /// Failed float-to-int conversion.
56    BadConversionToInteger = 8,
57
58    /// Code that was supposed to have been unreachable was reached.
59    UnreachableCodeReached = 9,
60
61    /// An atomic memory access was attempted with an unaligned pointer.
62    UnalignedAtomic = 10,
63
64    /// An exception was thrown but it was left uncaught.
65    UncaughtException = 11,
66
67    /// A throw_ref was executed but the exnref was not initialized.
68    UninitializedExnRef = 12,
69
70    /// An async imported function tried to yield when not called
71    /// via `Function::call_async`.
72    YieldOutsideAsyncContext = 13,
73
74    /// Another host thread requested interruption of running WASM.
75    HostInterrupt = 14,
76}
77
78impl TrapCode {
79    /// Gets the message for this trap code
80    pub fn message(&self) -> &str {
81        match self {
82            Self::StackOverflow => "call stack exhausted",
83            Self::HeapAccessOutOfBounds => "out of bounds memory access",
84            Self::HeapMisaligned => "misaligned heap",
85            Self::TableAccessOutOfBounds => "undefined element: out of bounds table access",
86            Self::IndirectCallToNull => "uninitialized element",
87            Self::BadSignature => "indirect call type mismatch",
88            Self::IntegerOverflow => "integer overflow",
89            Self::IntegerDivisionByZero => "integer divide by zero",
90            Self::BadConversionToInteger => "invalid conversion to integer",
91            Self::UnreachableCodeReached => "unreachable",
92            Self::UnalignedAtomic => "unaligned atomic access",
93            Self::UncaughtException => "uncaught exception",
94            Self::UninitializedExnRef => "uninitialized exnref",
95            Self::YieldOutsideAsyncContext => {
96                "async imported function yielded when not called via `Function::call_async`"
97            }
98            Self::HostInterrupt => "interrupted by host",
99        }
100    }
101}
102
103impl Display for TrapCode {
104    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
105        let identifier = match *self {
106            Self::StackOverflow => "stk_ovf",
107            Self::HeapAccessOutOfBounds => "heap_get_oob",
108            Self::HeapMisaligned => "heap_misaligned",
109            Self::TableAccessOutOfBounds => "table_get_oob",
110            Self::IndirectCallToNull => "icall_null",
111            Self::BadSignature => "bad_sig",
112            Self::IntegerOverflow => "int_ovf",
113            Self::IntegerDivisionByZero => "int_divz",
114            Self::BadConversionToInteger => "bad_toint",
115            Self::UnreachableCodeReached => "unreachable",
116            Self::UnalignedAtomic => "unalign_atom",
117            Self::UncaughtException => "uncaught_exception",
118            Self::UninitializedExnRef => "uninitialized_exnref",
119            Self::YieldOutsideAsyncContext => "yield_outside_async_context",
120            Self::HostInterrupt => "host_interrupt",
121        };
122        f.write_str(identifier)
123    }
124}
125
126impl FromStr for TrapCode {
127    type Err = ();
128
129    fn from_str(s: &str) -> Result<Self, Self::Err> {
130        match s {
131            "stk_ovf" => Ok(Self::StackOverflow),
132            "heap_get_oob" => Ok(Self::HeapAccessOutOfBounds),
133            "heap_misaligned" => Ok(Self::HeapMisaligned),
134            "table_get_oob" => Ok(Self::TableAccessOutOfBounds),
135            "icall_null" => Ok(Self::IndirectCallToNull),
136            "bad_sig" => Ok(Self::BadSignature),
137            "int_ovf" => Ok(Self::IntegerOverflow),
138            "int_divz" => Ok(Self::IntegerDivisionByZero),
139            "bad_toint" => Ok(Self::BadConversionToInteger),
140            "unreachable" => Ok(Self::UnreachableCodeReached),
141            "unalign_atom" => Ok(Self::UnalignedAtomic),
142            "uncaught_exception" => Ok(Self::UncaughtException),
143            "uninitialized_exnref" => Ok(Self::UninitializedExnRef),
144            "yield_outside_async_context" => Ok(Self::YieldOutsideAsyncContext),
145            "host_interrupt" => Ok(Self::HostInterrupt),
146            _ => Err(()),
147        }
148    }
149}
150
151// TODO: OnCalledAction is needed for asyncify. It will be refactored with https://github.com/wasmerio/wasmer/issues/3451
152/// After the stack is unwound via asyncify what
153/// should the call loop do next
154#[derive(Debug)]
155pub enum OnCalledAction {
156    /// Will call the function again
157    InvokeAgain,
158    /// Will return the result of the invocation
159    Finish,
160    /// Traps with an error
161    Trap(Box<dyn std::error::Error + Send + Sync>),
162}
163
164#[cfg(test)]
165mod tests {
166    use super::*;
167
168    // Everything but user-defined codes.
169    const CODES: [TrapCode; 11] = [
170        TrapCode::StackOverflow,
171        TrapCode::HeapAccessOutOfBounds,
172        TrapCode::HeapMisaligned,
173        TrapCode::TableAccessOutOfBounds,
174        TrapCode::IndirectCallToNull,
175        TrapCode::BadSignature,
176        TrapCode::IntegerOverflow,
177        TrapCode::IntegerDivisionByZero,
178        TrapCode::BadConversionToInteger,
179        TrapCode::UnreachableCodeReached,
180        TrapCode::UnalignedAtomic,
181    ];
182
183    #[test]
184    fn display() {
185        for r in &CODES {
186            let tc = *r;
187            assert_eq!(tc.to_string().parse(), Ok(tc));
188        }
189        assert_eq!("bogus".parse::<TrapCode>(), Err(()));
190
191        // assert_eq!(TrapCode::User(17).to_string(), "user17");
192        // assert_eq!("user22".parse(), Ok(TrapCode::User(22)));
193        assert_eq!("user".parse::<TrapCode>(), Err(()));
194        assert_eq!("user-1".parse::<TrapCode>(), Err(()));
195        assert_eq!("users".parse::<TrapCode>(), Err(()));
196    }
197}
wasmer_types/trapcode.rs

wasmer_types/
trapcode.rs
