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
71impl TrapCode {
72    /// Gets the message for this trap code
73    pub fn message(&self) -> &str {
74        match self {
75            Self::StackOverflow => "call stack exhausted",
76            Self::HeapAccessOutOfBounds => "out of bounds memory access",
77            Self::HeapMisaligned => "misaligned heap",
78            Self::TableAccessOutOfBounds => "undefined element: out of bounds table access",
79            Self::IndirectCallToNull => "uninitialized element",
80            Self::BadSignature => "indirect call type mismatch",
81            Self::IntegerOverflow => "integer overflow",
82            Self::IntegerDivisionByZero => "integer divide by zero",
83            Self::BadConversionToInteger => "invalid conversion to integer",
84            Self::UnreachableCodeReached => "unreachable",
85            Self::UnalignedAtomic => "unaligned atomic access",
86            Self::UncaughtException => "uncaught exception",
87            Self::UninitializedExnRef => "uninitialized exnref",
88        }
89    }
90}
91
92impl Display for TrapCode {
93    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
94        let identifier = match *self {
95            Self::StackOverflow => "stk_ovf",
96            Self::HeapAccessOutOfBounds => "heap_get_oob",
97            Self::HeapMisaligned => "heap_misaligned",
98            Self::TableAccessOutOfBounds => "table_get_oob",
99            Self::IndirectCallToNull => "icall_null",
100            Self::BadSignature => "bad_sig",
101            Self::IntegerOverflow => "int_ovf",
102            Self::IntegerDivisionByZero => "int_divz",
103            Self::BadConversionToInteger => "bad_toint",
104            Self::UnreachableCodeReached => "unreachable",
105            Self::UnalignedAtomic => "unalign_atom",
106            Self::UncaughtException => "uncaught_exception",
107            Self::UninitializedExnRef => "uninitialized_exnref",
108        };
109        f.write_str(identifier)
110    }
111}
112
113impl FromStr for TrapCode {
114    type Err = ();
115
116    fn from_str(s: &str) -> Result<Self, Self::Err> {
117        match s {
118            "stk_ovf" => Ok(Self::StackOverflow),
119            "heap_get_oob" => Ok(Self::HeapAccessOutOfBounds),
120            "heap_misaligned" => Ok(Self::HeapMisaligned),
121            "table_get_oob" => Ok(Self::TableAccessOutOfBounds),
122            "icall_null" => Ok(Self::IndirectCallToNull),
123            "bad_sig" => Ok(Self::BadSignature),
124            "int_ovf" => Ok(Self::IntegerOverflow),
125            "int_divz" => Ok(Self::IntegerDivisionByZero),
126            "bad_toint" => Ok(Self::BadConversionToInteger),
127            "unreachable" => Ok(Self::UnreachableCodeReached),
128            "unalign_atom" => Ok(Self::UnalignedAtomic),
129            "uncaught_exception" => Ok(Self::UncaughtException),
130            "uninitialized_exnref" => Ok(Self::UninitializedExnRef),
131            _ => Err(()),
132        }
133    }
134}
135
136// TODO: OnCalledAction is needed for asyncify. It will be refactored with https://github.com/wasmerio/wasmer/issues/3451
137/// After the stack is unwound via asyncify what
138/// should the call loop do next
139#[derive(Debug)]
140pub enum OnCalledAction {
141    /// Will call the function again
142    InvokeAgain,
143    /// Will return the result of the invocation
144    Finish,
145    /// Traps with an error
146    Trap(Box<dyn std::error::Error + Send + Sync>),
147}
148
149#[cfg(test)]
150mod tests {
151    use super::*;
152
153    // Everything but user-defined codes.
154    const CODES: [TrapCode; 11] = [
155        TrapCode::StackOverflow,
156        TrapCode::HeapAccessOutOfBounds,
157        TrapCode::HeapMisaligned,
158        TrapCode::TableAccessOutOfBounds,
159        TrapCode::IndirectCallToNull,
160        TrapCode::BadSignature,
161        TrapCode::IntegerOverflow,
162        TrapCode::IntegerDivisionByZero,
163        TrapCode::BadConversionToInteger,
164        TrapCode::UnreachableCodeReached,
165        TrapCode::UnalignedAtomic,
166    ];
167
168    #[test]
169    fn display() {
170        for r in &CODES {
171            let tc = *r;
172            assert_eq!(tc.to_string().parse(), Ok(tc));
173        }
174        assert_eq!("bogus".parse::<TrapCode>(), Err(()));
175
176        // assert_eq!(TrapCode::User(17).to_string(), "user17");
177        // assert_eq!("user22".parse(), Ok(TrapCode::User(22)));
178        assert_eq!("user".parse::<TrapCode>(), Err(()));
179        assert_eq!("user-1".parse::<TrapCode>(), Err(()));
180        assert_eq!("users".parse::<TrapCode>(), Err(()));
181    }
182}
wasmer_types/trapcode.rs

wasmer_types/
trapcode.rs
