bjoernager/rust
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macros: reuse SetOnce trait in diagnostic derive

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`SetOnce` trait was introduced in the subdiagnostic derive to simplify
the code a little bit, re-use it in the diagnostic derive too.

Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2022-04-27 04:28:21 +01:00
parent 36a396ce51
commit 2647a4812c
3 changed files with 102 additions and 96 deletions
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71
compiler/rustc_macros/src/diagnostics/diagnostic.rs
View file

@ -5,7 +5,8 @@ use crate::diagnostics::error::{
SessionDiagnosticDeriveError,
};
use crate::diagnostics::utils::{
option_inner_ty, report_error_if_not_applied_to_span, type_matches_path, FieldInfo, HasFieldMap,
option_inner_ty, report_error_if_not_applied_to_span, type_matches_path, FieldInfo,
HasFieldMap, SetOnce,
};
use proc_macro2::TokenStream;
use quote::{format_ident, quote};
@ -240,7 +241,7 @@ struct SessionDiagnosticDeriveBuilder {
slug: Option<(String, proc_macro::Span)>,
/// Error codes are a optional part of the struct attribute - this is only set to detect
/// multiple specifications.
code: Option<proc_macro::Span>,
code: Option<(String, proc_macro::Span)>,
}
impl HasFieldMap for SessionDiagnosticDeriveBuilder {
@ -306,7 +307,7 @@ impl SessionDiagnosticDeriveBuilder {
diag.help("only `error` and `warning` are valid attributes")
}),
};
self.set_kind_once(kind, span)?;
self.kind.set_once((kind, span));
let mut tokens = Vec::new();
for nested_attr in nested {
@ -321,12 +322,17 @@ impl SessionDiagnosticDeriveBuilder {
// Struct attributes are only allowed to be applied once, and the diagnostic
// changes will be set in the initialisation code.
Meta::NameValue(MetaNameValue { lit: syn::Lit::Str(s), .. }) => {
let span = s.span().unwrap();
match nested_name.as_str() {
"slug" => {
self.set_slug_once(s.value(), s.span().unwrap());
self.slug.set_once((s.value(), span));
}
"code" => {
tokens.push(self.set_code_once(s.value(), s.span().unwrap()));
self.code.set_once((s.value(), span));
let (diag, code) = (&self.diag, &self.code.as_ref().map(|(v, _)| v));
tokens.push(quote! {
#diag.code(rustc_errors::DiagnosticId::Error(#code.to_string()));
});
}
_ => invalid_nested_attr(attr, &nested_attr)
.help("only `slug` and `code` are valid nested attributes")
@ -340,61 +346,6 @@ impl SessionDiagnosticDeriveBuilder {
Ok(tokens.drain(..).collect())
}
#[must_use]
fn set_kind_once(
&mut self,
kind: SessionDiagnosticKind,
span: proc_macro::Span,
) -> Result<(), SessionDiagnosticDeriveError> {
match self.kind {
None => {
self.kind = Some((kind, span));
Ok(())
}
Some((prev_kind, prev_span)) => {
let existing = prev_kind.descr();
let current = kind.descr();
let msg = if current == existing {
format!("`{}` specified multiple times", existing)
} else {
format!("`{}` specified when `{}` was already specified", current, existing)
};
throw_span_err!(span, &msg, |diag| diag
.span_note(prev_span, "previously specified here"));
}
}
}
fn set_code_once(&mut self, code: String, span: proc_macro::Span) -> TokenStream {
match self.code {
None => {
self.code = Some(span);
}
Some(prev_span) => {
span_err(span, "`code` specified multiple times")
.span_note(prev_span, "previously specified here")
.emit();
}
}
let diag = &self.diag;
quote! { #diag.code(rustc_errors::DiagnosticId::Error(#code.to_string())); }
}
fn set_slug_once(&mut self, slug: String, span: proc_macro::Span) {
match self.slug {
None => {
self.slug = Some((slug, span));
}
Some((_, prev_span)) => {
span_err(span, "`slug` specified multiple times")
.span_note(prev_span, "previously specified here")
.emit();
}
}
}
fn generate_field_attr_code(
&mut self,
attr: &syn::Attribute,