wasmer_compiler/
error.rs

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
use crate::lib::std::string::String;
#[cfg(feature = "std")]
use thiserror::Error;

// Compilation Errors
//
// If `std` feature is enable, we can't use `thiserror` until
// https://github.com/dtolnay/thiserror/pull/64 is merged.

/// The WebAssembly.CompileError object indicates an error during
/// WebAssembly decoding or validation.
///
/// This is based on the [Wasm Compile Error][compile-error] API.
///
/// [compiler-error]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WebAssembly/CompileError
#[derive(Debug)]
#[cfg_attr(feature = "std", derive(Error))]
pub enum CompileError {
    /// A Wasm translation error occured.
    #[cfg_attr(feature = "std", error("WebAssembly translation error: {0}"))]
    Wasm(WasmError),

    /// A compilation error occured.
    #[cfg_attr(feature = "std", error("Compilation error: {0}"))]
    Codegen(String),

    /// The module did not pass validation.
    #[cfg_attr(feature = "std", error("Validation error: {0}"))]
    Validate(String),

    /// The compiler doesn't support a Wasm feature
    #[cfg_attr(feature = "std", error("Feature {0} is not yet supported"))]
    UnsupportedFeature(String),

    /// The compiler cannot compile for the given target.
    /// This can refer to the OS, the chipset or any other aspect of the target system.
    #[cfg_attr(feature = "std", error("The target {0} is not yet supported (see https://docs.wasmer.io/ecosystem/wasmer/wasmer-features)"))]
    UnsupportedTarget(String),

    /// Insufficient resources available for execution.
    #[cfg_attr(feature = "std", error("Insufficient resources: {0}"))]
    Resource(String),

    /// Cannot downcast the engine to a specific type.
    #[cfg_attr(
        feature = "std",
        error("cannot downcast the engine to a specific type")
    )]
    EngineDowncast,
}

impl From<WasmError> for CompileError {
    fn from(original: WasmError) -> Self {
        Self::Wasm(original)
    }
}

/// A error in the middleware.
#[derive(Debug)]
#[cfg_attr(feature = "std", derive(Error))]
#[cfg_attr(feature = "std", error("Error in middleware {name}: {message}"))]
pub struct MiddlewareError {
    /// The name of the middleware where the error was created
    pub name: String,
    /// The error message
    pub message: String,
}

impl MiddlewareError {
    /// Create a new `MiddlewareError`
    pub fn new<A: Into<String>, B: Into<String>>(name: A, message: B) -> Self {
        Self {
            name: name.into(),
            message: message.into(),
        }
    }
}

/// A WebAssembly translation error.
///
/// When a WebAssembly function can't be translated, one of these error codes will be returned
/// to describe the failure.
#[derive(Debug)]
#[cfg_attr(feature = "std", derive(Error))]
pub enum WasmError {
    /// The input WebAssembly code is invalid.
    ///
    /// This error code is used by a WebAssembly translator when it encounters invalid WebAssembly
    /// code. This should never happen for validated WebAssembly code.
    #[cfg_attr(
        feature = "std",
        error("Invalid input WebAssembly code at offset {offset}: {message}")
    )]
    InvalidWebAssembly {
        /// A string describing the validation error.
        message: String,
        /// The bytecode offset where the error occurred.
        offset: usize,
    },

    /// A feature used by the WebAssembly code is not supported by the embedding environment.
    ///
    /// Embedding environments may have their own limitations and feature restrictions.
    #[cfg_attr(feature = "std", error("Unsupported feature: {0}"))]
    Unsupported(String),

    /// An implementation limit was exceeded.
    #[cfg_attr(feature = "std", error("Implementation limit exceeded"))]
    ImplLimitExceeded,

    /// An error from the middleware error.
    #[cfg_attr(feature = "std", error("{0}"))]
    Middleware(MiddlewareError),

    /// A generic error.
    #[cfg_attr(feature = "std", error("{0}"))]
    Generic(String),
}

impl From<MiddlewareError> for WasmError {
    fn from(original: MiddlewareError) -> Self {
        Self::Middleware(original)
    }
}

/// The error that can happen while parsing a `str`
/// to retrieve a [`CpuFeature`](crate::target::CpuFeature).
#[derive(Debug)]
#[cfg_attr(feature = "std", derive(Error))]
pub enum ParseCpuFeatureError {
    /// The provided string feature doesn't exist
    #[cfg_attr(feature = "std", error("CpuFeature {0} not recognized"))]
    Missing(String),
}

/// A convenient alias for a `Result` that uses `WasmError` as the error type.
pub type WasmResult<T> = Result<T, WasmError>;

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn middleware_error_can_be_created() {
        let msg = String::from("Something went wrong");
        let error = MiddlewareError::new("manipulator3000", msg);
        assert_eq!(error.name, "manipulator3000");
        assert_eq!(error.message, "Something went wrong");
    }

    #[test]
    fn middleware_error_be_converted_to_wasm_error() {
        let error = WasmError::from(MiddlewareError::new("manipulator3000", "foo"));
        match error {
            WasmError::Middleware(MiddlewareError { name, message }) => {
                assert_eq!(name, "manipulator3000");
                assert_eq!(message, "foo");
            }
            err => panic!("Unexpected error: {:?}", err),
        }
    }
}