Make SetOnce nicer to use

This commit is contained in:
Xiretza 2022-09-11 18:30:18 +02:00
parent efb20bc855
commit d4a1a6f698
3 changed files with 39 additions and 26 deletions

View File

@ -18,6 +18,8 @@ use syn::{
};
use synstructure::{BindingInfo, Structure};
use super::utils::SpannedOption;
/// What kind of diagnostic is being derived - a fatal/error/warning or a lint?
#[derive(Copy, Clone, PartialEq, Eq)]
pub(crate) enum DiagnosticDeriveKind {
@ -40,10 +42,10 @@ pub(crate) struct DiagnosticDeriveBuilder {
pub kind: DiagnosticDeriveKind,
/// Slug is a mandatory part of the struct attribute as corresponds to the Fluent message that
/// has the actual diagnostic message.
pub slug: Option<(Path, proc_macro::Span)>,
pub slug: SpannedOption<Path>,
/// Error codes are a optional part of the struct attribute - this is only set to detect
/// multiple specifications.
pub code: Option<(String, proc_macro::Span)>,
pub code: SpannedOption<String>,
}
impl HasFieldMap for DiagnosticDeriveBuilder {
@ -191,7 +193,7 @@ impl DiagnosticDeriveBuilder {
match nested_attr {
NestedMeta::Meta(Meta::Path(path)) => {
if is_diag {
self.slug.set_once((path.clone(), span));
self.slug.set_once(path.clone(), span);
} else {
let fn_name = proc_macro2::Ident::new(name, attr.span());
return Ok(quote! { #diag.#fn_name(rustc_errors::fluent::#path); });
@ -224,8 +226,8 @@ impl DiagnosticDeriveBuilder {
let span = s.span().unwrap();
match nested_name.as_str() {
"code" => {
self.code.set_once((s.value(), span));
let code = &self.code.as_ref().map(|(v, _)| v);
self.code.set_once(s.value(), span);
let code = &self.code.value_ref();
tokens.push(quote! {
#diag.code(rustc_errors::DiagnosticId::Error(#code.to_string()));
});
@ -476,10 +478,10 @@ impl DiagnosticDeriveBuilder {
match nested_name {
"code" => {
let formatted_str = self.build_format(&s.value(), s.span());
code.set_once((formatted_str, span));
code.set_once(formatted_str, span);
}
"applicability" => match Applicability::from_str(&s.value()) {
Ok(v) => applicability.set_once((quote! { #v }, span)),
Ok(v) => applicability.set_once(quote! { #v }, span),
Err(()) => {
span_err(span, "invalid applicability").emit();
}
@ -546,7 +548,7 @@ impl DiagnosticDeriveBuilder {
fn span_and_applicability_of_ty(
&self,
info: FieldInfo<'_>,
) -> Result<(TokenStream, Option<(TokenStream, proc_macro::Span)>), DiagnosticDeriveError> {
) -> Result<(TokenStream, SpannedOption<TokenStream>), DiagnosticDeriveError> {
match &info.ty {
// If `ty` is `Span` w/out applicability, then use `Applicability::Unspecified`.
ty @ Type::Path(..) if type_matches_path(ty, &["rustc_span", "Span"]) => {
@ -570,9 +572,9 @@ impl DiagnosticDeriveBuilder {
for (idx, elem) in tup.elems.iter().enumerate() {
if type_matches_path(elem, &["rustc_span", "Span"]) {
span_idx.set_once((syn::Index::from(idx), elem.span().unwrap()));
span_idx.set_once(syn::Index::from(idx), elem.span().unwrap());
} else if type_matches_path(elem, &["rustc_errors", "Applicability"]) {
applicability_idx.set_once((syn::Index::from(idx), elem.span().unwrap()));
applicability_idx.set_once(syn::Index::from(idx), elem.span().unwrap());
} else {
type_err(&elem.span())?;
}

View File

@ -15,6 +15,8 @@ use std::str::FromStr;
use syn::{spanned::Spanned, Attribute, Meta, MetaList, MetaNameValue, NestedMeta, Path};
use synstructure::{BindingInfo, Structure, VariantInfo};
use super::utils::SpannedOption;
/// Which kind of suggestion is being created?
#[derive(Clone, Copy)]
enum SubdiagnosticSuggestionKind {
@ -195,10 +197,10 @@ struct SubdiagnosticDeriveBuilder<'a> {
fields: HashMap<String, TokenStream>,
/// Identifier for the binding to the `#[primary_span]` field.
span_field: Option<(proc_macro2::Ident, proc_macro::Span)>,
span_field: SpannedOption<proc_macro2::Ident>,
/// If a suggestion, the identifier for the binding to the `#[applicability]` field or a
/// `rustc_errors::Applicability::*` variant directly.
applicability: Option<(TokenStream, proc_macro::Span)>,
applicability: SpannedOption<TokenStream>,
/// Set to true when a `#[suggestion_part]` field is encountered, used to generate an error
/// during finalization if still `false`.
@ -283,7 +285,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
if let Some(nested_attr) = nested_iter.next() {
match nested_attr {
NestedMeta::Meta(Meta::Path(path)) => {
slug.set_once((path.clone(), span));
slug.set_once(path.clone(), span);
}
NestedMeta::Meta(meta @ Meta::NameValue(_))
if matches!(
@ -326,7 +328,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
"code" => {
if matches!(kind, SubdiagnosticKind::Suggestion { .. }) {
let formatted_str = self.build_format(&value.value(), value.span());
code.set_once((formatted_str, span));
code.set_once(formatted_str, span);
} else {
span_err(
span,
@ -349,7 +351,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
span_err(span, "invalid applicability").emit();
Applicability::Unspecified
});
self.applicability.set_once((quote! { #value }, span));
self.applicability.set_once(quote! { #value }, span);
} else {
span_err(
span,
@ -485,7 +487,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
report_error_if_not_applied_to_span(attr, &info)?;
let binding = info.binding.binding.clone();
self.span_field.set_once((binding, span));
self.span_field.set_once(binding, span);
Ok(quote! {})
}
@ -509,7 +511,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
report_error_if_not_applied_to_applicability(attr, &info)?;
let binding = info.binding.binding.clone();
self.applicability.set_once((quote! { #binding }, span));
self.applicability.set_once(quote! { #binding }, span);
} else {
span_err(span, "`#[applicability]` is only valid on suggestions").emit();
}
@ -577,7 +579,7 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
match nested_name {
"code" => {
let formatted_str = self.build_format(&value.value(), value.span());
code.set_once((formatted_str, span));
code.set_once(formatted_str, span);
}
_ => throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
diag.help("`code` is the only valid nested attribute")
@ -635,11 +637,12 @@ impl<'a> SubdiagnosticDeriveBuilder<'a> {
.map(|binding| self.generate_field_attr_code(binding, kind_stats))
.collect();
let span_field = self.span_field.as_ref().map(|(span, _)| span);
let applicability = self.applicability.take().map_or_else(
|| quote! { rustc_errors::Applicability::Unspecified },
|(applicability, _)| applicability,
);
let span_field = self.span_field.value_ref();
let applicability = self
.applicability
.take()
.value()
.unwrap_or_else(|| quote! { rustc_errors::Applicability::Unspecified });
let diag = &self.diag;
let mut calls = TokenStream::new();

View File

@ -172,13 +172,17 @@ pub(crate) struct FieldInfo<'a> {
/// Small helper trait for abstracting over `Option` fields that contain a value and a `Span`
/// for error reporting if they are set more than once.
pub(crate) trait SetOnce<T> {
fn set_once(&mut self, _: (T, Span));
fn set_once(&mut self, value: T, span: Span);
fn value(self) -> Option<T>;
fn value_ref(&self) -> Option<&T>;
}
impl<T> SetOnce<T> for Option<(T, Span)> {
fn set_once(&mut self, (value, span): (T, Span)) {
/// An [`Option<T>`] that keeps track of the span that caused it to be set; used with [`SetOnce`].
pub(super) type SpannedOption<T> = Option<(T, Span)>;
impl<T> SetOnce<T> for SpannedOption<T> {
fn set_once(&mut self, value: T, span: Span) {
match self {
None => {
*self = Some((value, span));
@ -194,6 +198,10 @@ impl<T> SetOnce<T> for Option<(T, Span)> {
fn value(self) -> Option<T> {
self.map(|(v, _)| v)
}
fn value_ref(&self) -> Option<&T> {
self.as_ref().map(|(v, _)| v)
}
}
pub(crate) trait HasFieldMap {