Files
wasmtime/cranelift/codegen/src/result.rs
Benjamin Bouvier ff37c9d8a4 [cranelift] Rejigger the compile API (#4540)
* Move `emit_to_memory` to `MachCompileResult`

This small refactoring makes it clearer to me that emitting to memory
doesn't require anything else from the compilation `Context`. While it's
a trivial change, it's a small public API change that shouldn't cause
too much trouble, and doesn't seem RFC-worthy. Happy to hear different
opinions about this, though!

* hide the MachCompileResult behind a method

* Add a `CompileError` wrapper type that references a `Function`

* Rename MachCompileResult to CompiledCode

* Additionally remove the last unsafe API in cranelift-codegen
2022-08-02 12:05:40 -07:00

103 lines
4.0 KiB
Rust

//! Result and error types representing the outcome of compiling a function.
use regalloc2::checker::CheckerErrors;
use crate::{ir::Function, verifier::VerifierErrors};
use std::string::String;
/// A compilation error.
///
/// When Cranelift fails to compile a function, it will return one of these error codes.
#[derive(Debug)]
pub enum CodegenError {
/// A list of IR verifier errors.
///
/// This always represents a bug, either in the code that generated IR for Cranelift, or a bug
/// in Cranelift itself.
Verifier(VerifierErrors),
/// An implementation limit was exceeded.
///
/// Cranelift can compile very large and complicated functions, but the [implementation has
/// limits][limits] that cause compilation to fail when they are exceeded.
///
/// [limits]: https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/docs/ir.md#implementation-limits
ImplLimitExceeded,
/// The code size for the function is too large.
///
/// Different target ISAs may impose a limit on the size of a compiled function. If that limit
/// is exceeded, compilation fails.
CodeTooLarge,
/// Something is not supported by the code generator. This might be an indication that a
/// feature is used without explicitly enabling it, or that something is temporarily
/// unsupported by a given target backend.
Unsupported(String),
/// A failure to map Cranelift register representation to a DWARF register representation.
#[cfg(feature = "unwind")]
RegisterMappingError(crate::isa::unwind::systemv::RegisterMappingError),
/// Register allocator internal error discovered by the symbolic checker.
Regalloc(CheckerErrors),
}
/// A convenient alias for a `Result` that uses `CodegenError` as the error type.
pub type CodegenResult<T> = Result<T, CodegenError>;
// This is manually implementing Error and Display instead of using thiserror to reduce the amount
// of dependencies used by Cranelift.
impl std::error::Error for CodegenError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
match self {
CodegenError::Verifier(source) => Some(source),
CodegenError::ImplLimitExceeded { .. }
| CodegenError::CodeTooLarge { .. }
| CodegenError::Unsupported { .. } => None,
#[cfg(feature = "unwind")]
CodegenError::RegisterMappingError { .. } => None,
CodegenError::Regalloc(..) => None,
}
}
}
impl std::fmt::Display for CodegenError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
CodegenError::Verifier(_) => write!(f, "Verifier errors"),
CodegenError::ImplLimitExceeded => write!(f, "Implementation limit exceeded"),
CodegenError::CodeTooLarge => write!(f, "Code for function is too large"),
CodegenError::Unsupported(feature) => write!(f, "Unsupported feature: {}", feature),
#[cfg(feature = "unwind")]
CodegenError::RegisterMappingError(_0) => write!(f, "Register mapping error"),
CodegenError::Regalloc(errors) => write!(f, "Regalloc validation errors: {:?}", errors),
}
}
}
impl From<VerifierErrors> for CodegenError {
fn from(source: VerifierErrors) -> Self {
CodegenError::Verifier { 0: source }
}
}
/// Compilation error, with the accompanying function to help printing it.
pub struct CompileError<'a> {
/// Underlying `CodegenError` that triggered the error.
pub inner: CodegenError,
/// Function we tried to compile, for display purposes.
pub func: &'a Function,
}
// By default, have `CompileError` be displayed as the internal error, and let consumers care if
// they want to use the func field for adding details.
impl<'a> core::fmt::Debug for CompileError<'a> {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
self.inner.fmt(f)
}
}
/// A convenient alias for a `Result` that uses `CompileError` as the error type.
pub type CompileResult<'a, T> = Result<T, CompileError<'a>>;