bjoernager/rust
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macros: support adding warnings to diags

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Both diagnostic and subdiagnostic derives were missing the ability to
add warnings to diagnostics - this is made more difficult by the `warn`
attribute already existing, so this name being unavailable for the
derives to use. `#[warn_]` is used instead, which requires
special-casing so that `{span_,}warn` is called instead of
`{span_,}warn_`.

Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2022-07-11 18:46:24 +01:00
parent 88c11c5bff
commit 81cf2294b4
8 changed files with 70 additions and 25 deletions
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51
compiler/rustc_macros/src/diagnostics/diagnostic_builder.rs
View file

@ -8,7 +8,7 @@ use crate::diagnostics::utils::{
report_error_if_not_applied_to_span, report_type_error, type_is_unit, type_matches_path,
Applicability, FieldInfo, FieldInnerTy, HasFieldMap, SetOnce,
};
use proc_macro2::{Ident, TokenStream};
use proc_macro2::{Ident, Span, TokenStream};
use quote::{format_ident, quote};
use std::collections::HashMap;
use std::str::FromStr;
@ -156,7 +156,7 @@ impl DiagnosticDeriveBuilder {
let name = name.as_str();
let meta = attr.parse_meta()?;
let is_help_or_note = matches!(name, "help" | "note");
let is_help_note_or_warn = matches!(name, "help" | "note" | "warn_");
let nested = match meta {
// Most attributes are lists, like `#[error(..)]`/`#[warning(..)]` for most cases or
@ -164,8 +164,12 @@ impl DiagnosticDeriveBuilder {
Meta::List(MetaList { ref nested, .. }) => nested,
// Subdiagnostics without spans can be applied to the type too, and these are just
// paths: `#[help]` and `#[note]`
Meta::Path(_) if is_help_or_note => {
let fn_name = proc_macro2::Ident::new(name, attr.span());
Meta::Path(_) if is_help_note_or_warn => {
let fn_name = if name == "warn_" {
Ident::new("warn", attr.span())
} else {
Ident::new(name, attr.span())
};
return Ok(quote! { #diag.#fn_name(rustc_errors::fluent::_subdiag::#fn_name); });
}
_ => throw_invalid_attr!(attr, &meta),
@ -177,9 +181,11 @@ impl DiagnosticDeriveBuilder {
"error" => self.kind.set_once((DiagnosticDeriveKind::Error, span)),
"warning" => self.kind.set_once((DiagnosticDeriveKind::Warn, span)),
"lint" => self.kind.set_once((DiagnosticDeriveKind::Lint, span)),
"help" | "note" => (),
"help" | "note" | "warn_" => (),
_ => throw_invalid_attr!(attr, &meta, |diag| {
diag.help("only `error`, `warning`, `help` and `note` are valid attributes")
diag.help(
"only `error`, `warning`, `help`, `note` and `warn_` are valid attributes",
)
}),
}
@ -188,14 +194,16 @@ impl DiagnosticDeriveBuilder {
let mut nested_iter = nested.into_iter();
if let Some(nested_attr) = nested_iter.next() {
// Report an error if there are any other list items after the path.
if is_help_or_note && nested_iter.next().is_some() {
if is_help_note_or_warn && nested_iter.next().is_some() {
throw_invalid_nested_attr!(attr, &nested_attr, |diag| {
diag.help("`help` and `note` struct attributes can only have one argument")
diag.help(
"`help`, `note` and `warn_` struct attributes can only have one argument",
)
});
}
match nested_attr {
NestedMeta::Meta(Meta::Path(path)) if is_help_or_note => {
NestedMeta::Meta(Meta::Path(path)) if is_help_note_or_warn => {
let fn_name = proc_macro2::Ident::new(name, attr.span());
return Ok(quote! { #diag.#fn_name(rustc_errors::fluent::#path); });
}
@ -203,7 +211,7 @@ impl DiagnosticDeriveBuilder {
self.slug.set_once((path.clone(), span));
}
NestedMeta::Meta(meta @ Meta::NameValue(_))
if !is_help_or_note
if !is_help_note_or_warn
&& meta.path().segments.last().unwrap().ident.to_string() == "code" =>
{
// don't error for valid follow-up attributes
@ -347,10 +355,12 @@ impl DiagnosticDeriveBuilder {
report_error_if_not_applied_to_span(attr, &info)?;
Ok(self.add_spanned_subdiagnostic(binding, ident, parse_quote! { _subdiag::label }))
}
"note" | "help" => {
let path = match name {
"note" => parse_quote! { _subdiag::note },
"help" => parse_quote! { _subdiag::help },
"note" | "help" | "warn_" => {
let warn_ident = Ident::new("warn", Span::call_site());
let (ident, path) = match name {
"note" => (ident, parse_quote! { _subdiag::note }),
"help" => (ident, parse_quote! { _subdiag::help }),
"warn_" => (&warn_ident, parse_quote! { _subdiag::warn }),
_ => unreachable!(),
};
if type_matches_path(&info.ty, &["rustc_span", "Span"]) {
@ -387,10 +397,10 @@ impl DiagnosticDeriveBuilder {
"suggestion" | "suggestion_short" | "suggestion_hidden" | "suggestion_verbose" => {
return self.generate_inner_field_code_suggestion(attr, info);
}
"label" | "help" | "note" => (),
"label" | "help" | "note" | "warn_" => (),
_ => throw_invalid_attr!(attr, &meta, |diag| {
diag.help(
"only `label`, `note`, `help` or `suggestion{,_short,_hidden,_verbose}` are \
"only `label`, `help`, `note`, `warn` or `suggestion{,_short,_hidden,_verbose}` are \
valid field attributes",
)
}),
@ -419,7 +429,14 @@ impl DiagnosticDeriveBuilder {
Ok(self.add_spanned_subdiagnostic(binding, ident, msg))
}
"note" | "help" if type_is_unit(&info.ty) => Ok(self.add_subdiagnostic(ident, msg)),
"note" | "help" => report_type_error(attr, "`Span` or `()`")?,
// `warn_` must be special-cased because the attribute `warn` already has meaning and
// so isn't used, despite the diagnostic API being named `warn`.
"warn_" if type_matches_path(&info.ty, &["rustc_span", "Span"]) => Ok(self
.add_spanned_subdiagnostic(binding, &Ident::new("warn", Span::call_site()), msg)),
"warn_" if type_is_unit(&info.ty) => {
Ok(self.add_subdiagnostic(&Ident::new("warn", Span::call_site()), msg))
}
"note" | "help" | "warn_" => report_type_error(attr, "`Span` or `()`")?,
_ => unreachable!(),
}
}