cranelift_codegen/
result.rs

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

cranelift_codegen/
result.rs
