wasmtime_types/
error.rs

1use alloc::string::String;
2use core::fmt;
3
4/// A WebAssembly translation error.
5///
6/// When a WebAssembly function can't be translated, one of these error codes will be returned
7/// to describe the failure.
8#[derive(Debug)]
9pub enum WasmError {
10    /// The input WebAssembly code is invalid.
11    ///
12    /// This error code is used by a WebAssembly translator when it encounters invalid WebAssembly
13    /// code. This should never happen for validated WebAssembly code.
14    InvalidWebAssembly {
15        /// A string describing the validation error.
16        message: String,
17        /// The bytecode offset where the error occurred.
18        offset: usize,
19    },
20
21    /// A feature used by the WebAssembly code is not supported by the embedding environment.
22    ///
23    /// Embedding environments may have their own limitations and feature restrictions.
24    Unsupported(String),
25
26    /// An implementation limit was exceeded.
27    ///
28    /// Cranelift can compile very large and complicated functions, but the [implementation has
29    /// limits][limits] that cause compilation to fail when they are exceeded.
30    ///
31    /// [limits]: https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/docs/ir.md#implementation-limits
32    ImplLimitExceeded,
33
34    /// Any user-defined error.
35    User(String),
36}
37
38/// Return an `Err(WasmError::Unsupported(msg))` where `msg` the string built by calling `format!`
39/// on the arguments to this macro.
40#[macro_export]
41macro_rules! wasm_unsupported {
42    ($($arg:tt)*) => { $crate::WasmError::Unsupported($crate::__format!($($arg)*)) }
43}
44
45impl From<wasmparser::BinaryReaderError> for WasmError {
46    /// Convert from a `BinaryReaderError` to a `WasmError`.
47    fn from(e: wasmparser::BinaryReaderError) -> Self {
48        Self::InvalidWebAssembly {
49            message: e.message().into(),
50            offset: e.offset(),
51        }
52    }
53}
54
55/// A convenient alias for a `Result` that uses `WasmError` as the error type.
56pub type WasmResult<T> = Result<T, WasmError>;
57
58impl fmt::Display for WasmError {
59    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
60        match self {
61            WasmError::InvalidWebAssembly { message, offset } => {
62                write!(
63                    f,
64                    "Invalid input WebAssembly code at offset {offset}: {message}"
65                )
66            }
67            WasmError::Unsupported(s) => {
68                write!(f, "Unsupported feature: {s}")
69            }
70            WasmError::ImplLimitExceeded => {
71                write!(f, "Implementation limit exceeded")
72            }
73            WasmError::User(s) => {
74                write!(f, "User error: {s}")
75            }
76        }
77    }
78}
79
80#[cfg(feature = "std")]
81impl std::error::Error for WasmError {}
wasmtime_types/error.rs

wasmtime_types/
error.rs
