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

cranelift_codegen/
result.rs
