61 lines
1.9 KiB
Rust
61 lines
1.9 KiB
Rust
|
use proc_macro::{Diagnostic, Level, MultiSpan};
|
||
|
|
use proc_macro2::TokenStream;
|
||
|
|
use quote::quote;
|
||
|
|
use syn;
|
||
|
|
|
||
|
|
#[derive(Debug)]
|
||
|
|
pub(crate) enum SessionDiagnosticDeriveError {
|
||
|
|
SynError(syn::Error),
|
||
|
|
ErrorHandled,
|
||
|
|
}
|
||
|
|
|
||
|
|
impl SessionDiagnosticDeriveError {
|
||
|
|
pub(crate) fn to_compile_error(self) -> TokenStream {
|
||
|
|
match self {
|
||
|
|
SessionDiagnosticDeriveError::SynError(e) => e.to_compile_error(),
|
||
|
|
SessionDiagnosticDeriveError::ErrorHandled => {
|
||
|
|
// Return ! to avoid having to create a blank DiagnosticBuilder to return when an
|
||
|
|
// error has already been emitted to the compiler.
|
||
|
|
quote! {
|
||
|
|
{ unreachable!(); }
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
pub(crate) fn span_err(span: impl MultiSpan, msg: &str) -> Diagnostic {
|
||
|
|
Diagnostic::spanned(span, Level::Error, msg)
|
||
|
|
}
|
||
|
|
|
||
|
|
/// For methods that return a `Result<_, SessionDiagnosticDeriveError>`:
|
||
|
|
///
|
||
|
|
/// Emit a diagnostic on span `$span` with msg `$msg` (optionally performing additional decoration
|
||
|
|
/// using the `FnOnce` passed in `diag`) and return `Err(ErrorHandled)`.
|
||
|
|
macro_rules! throw_span_err {
|
||
|
|
($span:expr, $msg:expr) => {{ throw_span_err!($span, $msg, |diag| diag) }};
|
||
|
|
($span:expr, $msg:expr, $f:expr) => {{
|
||
|
|
return Err(crate::diagnostics::error::_throw_span_err($span, $msg, $f));
|
||
|
|
}};
|
||
|
|
}
|
||
|
|
|
||
|
|
pub(crate) use throw_span_err;
|
||
|
|
|
||
|
|
/// When possible, prefer using `throw_span_err!` over using this function directly. This only
|
||
|
|
/// exists as a function to constrain `f` to an `impl FnOnce`.
|
||
|
|
pub(crate) fn _throw_span_err(
|
||
|
|
span: impl MultiSpan,
|
||
|
|
msg: &str,
|
||
|
|
f: impl FnOnce(Diagnostic) -> Diagnostic,
|
||
|
|
) -> SessionDiagnosticDeriveError {
|
||
|
|
let diag = span_err(span, msg);
|
||
|
|
f(diag).emit();
|
||
|
|
SessionDiagnosticDeriveError::ErrorHandled
|
||
|
|
}
|
||
|
|
|
||
|
|
impl From<syn::Error> for SessionDiagnosticDeriveError {
|
||
|
|
fn from(e: syn::Error) -> Self {
|
||
|
|
SessionDiagnosticDeriveError::SynError(e)
|
||
|
|
}
|
||
|
|
}
|