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
75impl TrapCode {
76    /// Gets the message for this trap code
77    pub fn message(&self) -> &str {
78        match self {
79            Self::StackOverflow => "call stack exhausted",
80            Self::HeapAccessOutOfBounds => "out of bounds memory access",
81            Self::HeapMisaligned => "misaligned heap",
82            Self::TableAccessOutOfBounds => "undefined element: out of bounds table access",
83            Self::IndirectCallToNull => "uninitialized element",
84            Self::BadSignature => "indirect call type mismatch",
85            Self::IntegerOverflow => "integer overflow",
86            Self::IntegerDivisionByZero => "integer divide by zero",
87            Self::BadConversionToInteger => "invalid conversion to integer",
88            Self::UnreachableCodeReached => "unreachable",
89            Self::UnalignedAtomic => "unaligned atomic access",
90            Self::UncaughtException => "uncaught exception",
91            Self::UninitializedExnRef => "uninitialized exnref",
92            Self::YieldOutsideAsyncContext => {
93                "async imported function yielded when not called via `Function::call_async`"
94            }
95        }
96    }
97}
98
99impl Display for TrapCode {
100    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
101        let identifier = match *self {
102            Self::StackOverflow => "stk_ovf",
103            Self::HeapAccessOutOfBounds => "heap_get_oob",
104            Self::HeapMisaligned => "heap_misaligned",
105            Self::TableAccessOutOfBounds => "table_get_oob",
106            Self::IndirectCallToNull => "icall_null",
107            Self::BadSignature => "bad_sig",
108            Self::IntegerOverflow => "int_ovf",
109            Self::IntegerDivisionByZero => "int_divz",
110            Self::BadConversionToInteger => "bad_toint",
111            Self::UnreachableCodeReached => "unreachable",
112            Self::UnalignedAtomic => "unalign_atom",
113            Self::UncaughtException => "uncaught_exception",
114            Self::UninitializedExnRef => "uninitialized_exnref",
115            Self::YieldOutsideAsyncContext => "yield_outside_async_context",
116        };
117        f.write_str(identifier)
118    }
119}
120
121impl FromStr for TrapCode {
122    type Err = ();
123
124    fn from_str(s: &str) -> Result<Self, Self::Err> {
125        match s {
126            "stk_ovf" => Ok(Self::StackOverflow),
127            "heap_get_oob" => Ok(Self::HeapAccessOutOfBounds),
128            "heap_misaligned" => Ok(Self::HeapMisaligned),
129            "table_get_oob" => Ok(Self::TableAccessOutOfBounds),
130            "icall_null" => Ok(Self::IndirectCallToNull),
131            "bad_sig" => Ok(Self::BadSignature),
132            "int_ovf" => Ok(Self::IntegerOverflow),
133            "int_divz" => Ok(Self::IntegerDivisionByZero),
134            "bad_toint" => Ok(Self::BadConversionToInteger),
135            "unreachable" => Ok(Self::UnreachableCodeReached),
136            "unalign_atom" => Ok(Self::UnalignedAtomic),
137            "uncaught_exception" => Ok(Self::UncaughtException),
138            "uninitialized_exnref" => Ok(Self::UninitializedExnRef),
139            "yield_outside_async_context" => Ok(Self::YieldOutsideAsyncContext),
140            _ => Err(()),
141        }
142    }
143}
144
145// TODO: OnCalledAction is needed for asyncify. It will be refactored with https://github.com/wasmerio/wasmer/issues/3451
146/// After the stack is unwound via asyncify what
147/// should the call loop do next
148#[derive(Debug)]
149pub enum OnCalledAction {
150    /// Will call the function again
151    InvokeAgain,
152    /// Will return the result of the invocation
153    Finish,
154    /// Traps with an error
155    Trap(Box<dyn std::error::Error + Send + Sync>),
156}
157
158#[cfg(test)]
159mod tests {
160    use super::*;
161
162    // Everything but user-defined codes.
163    const CODES: [TrapCode; 11] = [
164        TrapCode::StackOverflow,
165        TrapCode::HeapAccessOutOfBounds,
166        TrapCode::HeapMisaligned,
167        TrapCode::TableAccessOutOfBounds,
168        TrapCode::IndirectCallToNull,
169        TrapCode::BadSignature,
170        TrapCode::IntegerOverflow,
171        TrapCode::IntegerDivisionByZero,
172        TrapCode::BadConversionToInteger,
173        TrapCode::UnreachableCodeReached,
174        TrapCode::UnalignedAtomic,
175    ];
176
177    #[test]
178    fn display() {
179        for r in &CODES {
180            let tc = *r;
181            assert_eq!(tc.to_string().parse(), Ok(tc));
182        }
183        assert_eq!("bogus".parse::<TrapCode>(), Err(()));
184
185        // assert_eq!(TrapCode::User(17).to_string(), "user17");
186        // assert_eq!("user22".parse(), Ok(TrapCode::User(22)));
187        assert_eq!("user".parse::<TrapCode>(), Err(()));
188        assert_eq!("user-1".parse::<TrapCode>(), Err(()));
189        assert_eq!("users".parse::<TrapCode>(), Err(()));
190    }
191}
wasmer_types/trapcode.rs

wasmer_types/
trapcode.rs
