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macros: note/help in SessionDiagnostic derive

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Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2022-03-31 12:10:00 +01:00
parent a88717cef0
commit b40ee88a28
4 changed files with 159 additions and 11 deletions
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2
compiler/rustc_macros/src/lib.rs
View file

@ -66,6 +66,8 @@ decl_derive!(
// struct attributes
warning,
error,
note,
help,
// field attributes
skip_arg,
primary_span,

54
compiler/rustc_macros/src/session_diagnostic.rs
View file

@ -362,18 +362,52 @@ struct SessionDiagnosticDeriveBuilder<'a> {
impl<'a> SessionDiagnosticDeriveBuilder<'a> {
/// Establishes state in the `SessionDiagnosticDeriveBuilder` resulting from the struct
/// attributes like `#[error(..)#`, such as the diagnostic kind, slug and code.
///
/// Returns a `proc_macro2::TokenStream` so that the `Err(..)` variant can be transformed into
/// the same type via `to_compile_error`.
/// attributes like `#[error(..)#`, such as the diagnostic kind and slug. Generates
/// diagnostic builder calls for setting error code and creating note/help messages.
fn generate_structure_code(
&mut self,
attr: &syn::Attribute,
) -> Result<proc_macro2::TokenStream, SessionDiagnosticDeriveError> {
let span = attr.span().unwrap();
let name = attr.path.segments.last().unwrap().ident.to_string();
let nested = match attr.parse_meta()? {
let name = attr.path.segments.last().unwrap().ident.to_string();
let name = name.as_str();
let meta = attr.parse_meta()?;
if matches!(name, "help" | "note")
&& matches!(meta, syn::Meta::Path(_) | syn::Meta::NameValue(_))
{
let diag = &self.diag;
let slug = match &self.slug {
Some((slug, _)) => slug.as_str(),
None => throw_span_err!(
span,
&format!(
"`#[{}{}]` must come after `#[error(..)]` or `#[warn(..)]`",
name,
match meta {
syn::Meta::Path(_) => "",
syn::Meta::NameValue(_) => " = ...",
_ => unreachable!(),
}
)
),
};
let id = match meta {
syn::Meta::Path(..) => quote! { #name },
syn::Meta::NameValue(syn::MetaNameValue { lit: syn::Lit::Str(s), .. }) => {
quote! { #s }
}
_ => unreachable!(),
};
let fn_name = proc_macro2::Ident::new(name, attr.span());
return Ok(quote! {
#diag.#fn_name(rustc_errors::DiagnosticMessage::fluent_attr(#slug, #id));
});
}
let nested = match meta {
syn::Meta::List(syn::MetaList { nested, .. }) => nested,
syn::Meta::Path(..) => throw_span_err!(
span,
@ -385,7 +419,7 @@ impl<'a> SessionDiagnosticDeriveBuilder<'a> {
),
};
let kind = match name.as_str() {
let kind = match name {
"error" => SessionDiagnosticKind::Error,
"warning" => SessionDiagnosticKind::Warn,
other => throw_span_err!(
@ -579,9 +613,9 @@ impl<'a> SessionDiagnosticDeriveBuilder<'a> {
#diag.set_span(*#field_binding);
})
}
"label" => {
"label" | "note" | "help" => {
self.report_error_if_not_applied_to_span(attr, info)?;
Ok(self.add_subdiagnostic(field_binding, name, "label"))
Ok(self.add_subdiagnostic(field_binding, name, name))
}
other => throw_span_err!(
attr.span().unwrap(),
@ -589,7 +623,7 @@ impl<'a> SessionDiagnosticDeriveBuilder<'a> {
),
},
syn::Meta::NameValue(syn::MetaNameValue { lit: syn::Lit::Str(s), .. }) => match name {
"label" => {
"label" | "note" | "help" => {
self.report_error_if_not_applied_to_span(attr, info)?;
Ok(self.add_subdiagnostic(field_binding, name, &s.value()))
}