cranelift_codegen/
result.rs

1//! Result and error types representing the outcome of compiling a function.
2
3use regalloc2::checker::CheckerErrors;
4
5use crate::ir::pcc::PccError;
6use crate::{ir::Function, verifier::VerifierErrors};
7use std::string::String;
8
9/// A compilation error.
10///
11/// When Cranelift fails to compile a function, it will return one of these error codes.
12#[derive(Debug)]
13pub enum CodegenError {
14    /// A list of IR verifier errors.
15    ///
16    /// This always represents a bug, either in the code that generated IR for Cranelift, or a bug
17    /// in Cranelift itself.
18    Verifier(VerifierErrors),
19
20    /// An implementation limit was exceeded.
21    ///
22    /// Cranelift can compile very large and complicated functions, but the [implementation has
23    /// limits][limits] that cause compilation to fail when they are exceeded.
24    ///
25    /// [limits]: https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/docs/ir.md#implementation-limits
26    ImplLimitExceeded,
27
28    /// The code size for the function is too large.
29    ///
30    /// Different target ISAs may impose a limit on the size of a compiled function. If that limit
31    /// is exceeded, compilation fails.
32    CodeTooLarge,
33
34    /// Something is not supported by the code generator. This might be an indication that a
35    /// feature is used without explicitly enabling it, or that something is temporarily
36    /// unsupported by a given target backend.
37    Unsupported(String),
38
39    /// A failure to map Cranelift register representation to a DWARF register representation.
40    #[cfg(feature = "unwind")]
41    RegisterMappingError(crate::isa::unwind::systemv::RegisterMappingError),
42
43    /// Register allocator internal error discovered by the symbolic checker.
44    Regalloc(CheckerErrors),
45
46    /// Proof-carrying-code validation error.
47    Pcc(PccError),
48}
49
50/// A convenient alias for a `Result` that uses `CodegenError` as the error type.
51pub type CodegenResult<T> = Result<T, CodegenError>;
52
53// This is manually implementing Error and Display instead of using thiserror to reduce the amount
54// of dependencies used by Cranelift.
55impl std::error::Error for CodegenError {
56    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
57        match self {
58            CodegenError::Verifier(source) => Some(source),
59            CodegenError::ImplLimitExceeded { .. }
60            | CodegenError::CodeTooLarge { .. }
61            | CodegenError::Unsupported { .. } => None,
62            #[cfg(feature = "unwind")]
63            CodegenError::RegisterMappingError { .. } => None,
64            CodegenError::Regalloc(..) => None,
65            CodegenError::Pcc(..) => None,
66        }
67    }
68}
69
70impl std::fmt::Display for CodegenError {
71    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
72        match self {
73            CodegenError::Verifier(_) => write!(f, "Verifier errors"),
74            CodegenError::ImplLimitExceeded => write!(f, "Implementation limit exceeded"),
75            CodegenError::CodeTooLarge => write!(f, "Code for function is too large"),
76            CodegenError::Unsupported(feature) => write!(f, "Unsupported feature: {feature}"),
77            #[cfg(feature = "unwind")]
78            CodegenError::RegisterMappingError(_0) => write!(f, "Register mapping error"),
79            CodegenError::Regalloc(errors) => write!(f, "Regalloc validation errors: {errors:?}"),
80
81            // NOTE: if this is changed, please update the `is_pcc_error` function defined in
82            // `wasmtime/crates/fuzzing/src/oracles.rs`
83            CodegenError::Pcc(e) => write!(f, "Proof-carrying-code validation error: {e:?}"),
84        }
85    }
86}
87
88impl From<VerifierErrors> for CodegenError {
89    fn from(source: VerifierErrors) -> Self {
90        CodegenError::Verifier { 0: source }
91    }
92}
93
94/// Compilation error, with the accompanying function to help printing it.
95pub struct CompileError<'a> {
96    /// Underlying `CodegenError` that triggered the error.
97    pub inner: CodegenError,
98    /// Function we tried to compile, for display purposes.
99    pub func: &'a Function,
100}
101
102// By default, have `CompileError` be displayed as the internal error, and let consumers care if
103// they want to use the func field for adding details.
104impl<'a> core::fmt::Debug for CompileError<'a> {
105    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
106        self.inner.fmt(f)
107    }
108}
109
110/// A convenient alias for a `Result` that uses `CompileError` as the error type.
111pub type CompileResult<'a, T> = Result<T, CompileError<'a>>;
cranelift_codegen/result.rs

cranelift_codegen/
result.rs
