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Reduce capabilities of Diagnostic.

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Currently many diagnostic modifier methods are available on both
`Diagnostic` and `DiagnosticBuilder`. This commit removes most of them
from `Diagnostic`. To minimize the diff size, it keeps them within
`diagnostic.rs` but changes the surrounding `impl Diagnostic` block to
`impl DiagnosticBuilder`. (I intend to move things around later, to give
a more sensible code layout.)

`Diagnostic` keeps a few methods that it still needs, like `sub`,
`arg`, and `replace_args`.

The `forward!` macro, which defined two additional methods per call
(e.g. `note` and `with_note`), is replaced by the `with_fn!` macro,
which defines one additional method per call (e.g. `with_note`). It's
now also only used when necessary -- not all modifier methods currently
need a `with_*` form. (New ones can be easily added as necessary.)

All this also requires changing `trait AddToDiagnostic` so its methods
take `DiagnosticBuilder` instead of `Diagnostic`, which leads to many
mechanical changes. `SubdiagnosticMessageOp` gains a type parameter `G`.

There are three subdiagnostics -- `DelayedAtWithoutNewline`,
`DelayedAtWithNewline`, and `InvalidFlushedDelayedDiagnosticLevel` --
that are created within the diagnostics machinery and appended to
external diagnostics. These are handled at the `Diagnostic` level, which
means it's now hard to construct them via `derive(Diagnostic)`, so
instead we construct them by hand. This has no effect on what they look
like when printed.

There are lots of new `allow` markers for `untranslatable_diagnostics`
and `diagnostics_outside_of_impl`. This is because
`#[rustc_lint_diagnostics]` annotations were present on the `Diagnostic`
modifier methods, but missing from the `DiagnosticBuilder` modifier
methods. They're now present.
This commit is contained in:
Nicholas Nethercote 2024-02-06 16:44:30 +11:00
parent b18f3e11fa
commit f6f8779843
40 changed files with 502 additions and 395 deletions
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212
compiler/rustc_errors/src/diagnostic.rs
View file

@ -12,6 +12,7 @@ use rustc_span::{Span, DUMMY_SP};
use std::borrow::Cow;
use std::fmt::{self, Debug};
use std::hash::{Hash, Hasher};
use std::ops::{Deref, DerefMut};
use std::panic::Location;
/// Error type for `Diagnostic`'s `suggestions` field, indicating that
@ -71,17 +72,21 @@ where
Self: Sized,
{
/// Add a subdiagnostic to an existing diagnostic.
fn add_to_diagnostic(self, diag: &mut Diagnostic) {
fn add_to_diagnostic<G: EmissionGuarantee>(self, diag: &mut DiagnosticBuilder<'_, G>) {
self.add_to_diagnostic_with(diag, |_, m| m);
}
/// Add a subdiagnostic to an existing diagnostic where `f` is invoked on every message used
/// (to optionally perform eager translation).
fn add_to_diagnostic_with<F: SubdiagnosticMessageOp>(self, diag: &mut Diagnostic, f: F);
fn add_to_diagnostic_with<G: EmissionGuarantee, F: SubdiagnosticMessageOp<G>>(
self,
diag: &mut DiagnosticBuilder<'_, G>,
f: F,
);
}
pub trait SubdiagnosticMessageOp =
Fn(&mut Diagnostic, SubdiagnosticMessage) -> SubdiagnosticMessage;
pub trait SubdiagnosticMessageOp<G> =
Fn(&mut DiagnosticBuilder<'_, G>, SubdiagnosticMessage) -> SubdiagnosticMessage;
/// Trait implemented by lint types. This should not be implemented manually. Instead, use
/// `#[derive(LintDiagnostic)]` -- see [rustc_macros::LintDiagnostic].
@ -93,6 +98,10 @@ pub trait DecorateLint<'a, G: EmissionGuarantee> {
fn msg(&self) -> DiagnosticMessage;
}
/// The main part of a diagnostic. Note that `DiagnosticBuilder`, which wraps
/// this type, is used for most operations, and should be used instead whenever
/// possible. This type should only be used when `DiagnosticBuilder`'s lifetime
/// causes difficulties, e.g. when storing diagnostics within `DiagCtxt`.
#[must_use]
#[derive(Clone, Debug, Encodable, Decodable)]
pub struct Diagnostic {
@ -289,6 +298,90 @@ impl Diagnostic {
}
}
// See comment on `DiagnosticBuilder::subdiagnostic_message_to_diagnostic_message`.
pub(crate) fn subdiagnostic_message_to_diagnostic_message(
&self,
attr: impl Into<SubdiagnosticMessage>,
) -> DiagnosticMessage {
let msg =
self.messages.iter().map(|(msg, _)| msg).next().expect("diagnostic with no messages");
msg.with_subdiagnostic_message(attr.into())
}
pub(crate) fn sub(
&mut self,
level: Level,
message: impl Into<SubdiagnosticMessage>,
span: MultiSpan,
) {
let sub = SubDiagnostic {
level,
messages: vec![(
self.subdiagnostic_message_to_diagnostic_message(message),
Style::NoStyle,
)],
span,
};
self.children.push(sub);
}
pub(crate) fn arg(&mut self, name: impl Into<DiagnosticArgName>, arg: impl IntoDiagnosticArg) {
self.args.insert(name.into(), arg.into_diagnostic_arg());
}
pub fn args(&self) -> impl Iterator<Item = DiagnosticArg<'_>> {
self.args.iter()
}
pub fn replace_args(&mut self, args: FxIndexMap<DiagnosticArgName, DiagnosticArgValue>) {
self.args = args;
}
}
/// `DiagnosticBuilder` impls many `&mut self -> &mut Self` methods. Each one
/// modifies an existing diagnostic, either in a standalone fashion, e.g.
/// `err.code(code);`, or in a chained fashion to make multiple modifications,
/// e.g. `err.code(code).span(span);`.
///
/// This macro creates an equivalent `self -> Self` method, with a `with_`
/// prefix. This can be used in a chained fashion when making a new diagnostic,
/// e.g. `let err = struct_err(msg).with_code(code);`, or emitting a new
/// diagnostic, e.g. `struct_err(msg).with_code(code).emit();`.
///
/// Although the latter method can be used to modify an existing diagnostic,
/// e.g. `err = err.with_code(code);`, this should be avoided because the former
/// method gives shorter code, e.g. `err.code(code);`.
///
/// Note: the `with_` methods are added only when needed. If you want to use
/// one and it's not defined, feel free to add it.
///
/// Note: any doc comments must be within the `with_fn!` call.
macro_rules! with_fn {
{
$with_f:ident,
$(#[$attrs:meta])*
pub fn $f:ident(&mut $self:ident, $($name:ident: $ty:ty),* $(,)?) -> &mut Self {
$($body:tt)*
}
} => {
// The original function.
$(#[$attrs])*
#[doc = concat!("See [`DiagnosticBuilder::", stringify!($f), "()`].")]
pub fn $f(&mut $self, $($name: $ty),*) -> &mut Self {
$($body)*
}
// The `with_*` variant.
$(#[$attrs])*
#[doc = concat!("See [`DiagnosticBuilder::", stringify!($f), "()`].")]
pub fn $with_f(mut $self, $($name: $ty),*) -> Self {
$self.$f($($name),*);
$self
}
};
}
impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
/// Delay emission of this diagnostic as a bug.
///
/// This can be useful in contexts where an error indicates a bug but
@ -309,6 +402,7 @@ impl Diagnostic {
self.level = Level::DelayedBug;
}
with_fn! { with_span_label,
/// Appends a labeled span to the diagnostic.
///
/// Labels are used to convey additional context for the diagnostic's primary span. They will
@ -323,10 +417,12 @@ impl Diagnostic {
/// primary.
#[rustc_lint_diagnostics]
pub fn span_label(&mut self, span: Span, label: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.span.push_span_label(span, self.subdiagnostic_message_to_diagnostic_message(label));
let msg = self.subdiagnostic_message_to_diagnostic_message(label);
self.span.push_span_label(span, msg);
self
}
} }
with_fn! { with_span_labels,
/// Labels all the given spans with the provided label.
/// See [`Self::span_label()`] for more information.
pub fn span_labels(&mut self, spans: impl IntoIterator<Item = Span>, label: &str) -> &mut Self {
@ -334,7 +430,7 @@ impl Diagnostic {
self.span_label(span, label.to_string());
}
self
}
} }
pub fn replace_span_with(&mut self, after: Span, keep_label: bool) -> &mut Self {
let before = self.span.clone();
@ -412,39 +508,40 @@ impl Diagnostic {
self
}
with_fn! { with_note,
/// Add a note attached to this diagnostic.
#[rustc_lint_diagnostics]
pub fn note(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.sub(Level::Note, msg, MultiSpan::new());
self
}
} }
fn highlighted_note(&mut self, msg: Vec<StringPart>) -> &mut Self {
self.sub_with_highlights(Level::Note, msg, MultiSpan::new());
self
}
/// Prints the span with a note above it.
/// This is like [`Diagnostic::note()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::note()`], but it's only printed once.
pub fn note_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.sub(Level::OnceNote, msg, MultiSpan::new());
self
}
with_fn! { with_span_note,
/// Prints the span with a note above it.
/// This is like [`Diagnostic::note()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::note()`], but it gets its own span.
#[rustc_lint_diagnostics]
pub fn span_note<S: Into<MultiSpan>>(
pub fn span_note(
&mut self,
sp: S,
sp: impl Into<MultiSpan>,
msg: impl Into<SubdiagnosticMessage>,
) -> &mut Self {
self.sub(Level::Note, msg, sp.into());
self
}
} }
/// Prints the span with a note above it.
/// This is like [`Diagnostic::note()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::note_once()`], but it gets its own span.
pub fn span_note_once<S: Into<MultiSpan>>(
&mut self,
sp: S,
@ -454,15 +551,16 @@ impl Diagnostic {
self
}
with_fn! { with_warn,
/// Add a warning attached to this diagnostic.
#[rustc_lint_diagnostics]
pub fn warn(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.sub(Level::Warning, msg, MultiSpan::new());
self
}
} }
/// Prints the span with a warning above it.
/// This is like [`Diagnostic::warn()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::warn()`], but it gets its own span.
#[rustc_lint_diagnostics]
pub fn span_warn<S: Into<MultiSpan>>(
&mut self,
@ -473,15 +571,15 @@ impl Diagnostic {
self
}
with_fn! { with_help,
/// Add a help message attached to this diagnostic.
#[rustc_lint_diagnostics]
pub fn help(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.sub(Level::Help, msg, MultiSpan::new());
self
}
} }
/// Prints the span with a help above it.
/// This is like [`Diagnostic::help()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::help()`], but it's only printed once.
pub fn help_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
self.sub(Level::OnceHelp, msg, MultiSpan::new());
self
@ -494,7 +592,7 @@ impl Diagnostic {
}
/// Prints the span with some help above it.
/// This is like [`Diagnostic::help()`], but it gets its own span.
/// This is like [`DiagnosticBuilder::help()`], but it gets its own span.
#[rustc_lint_diagnostics]
pub fn span_help<S: Into<MultiSpan>>(
&mut self,
@ -531,6 +629,7 @@ impl Diagnostic {
}
}
with_fn! { with_multipart_suggestion,
/// Show a suggestion that has multiple parts to it.
/// In other words, multiple changes need to be applied as part of this suggestion.
pub fn multipart_suggestion(
@ -545,7 +644,7 @@ impl Diagnostic {
applicability,
SuggestionStyle::ShowCode,
)
}
} }
/// Show a suggestion that has multiple parts to it, always as it's own subdiagnostic.
/// In other words, multiple changes need to be applied as part of this suggestion.
@ -562,7 +661,8 @@ impl Diagnostic {
SuggestionStyle::ShowAlways,
)
}
/// [`Diagnostic::multipart_suggestion()`] but you can set the [`SuggestionStyle`].
/// [`DiagnosticBuilder::multipart_suggestion()`] but you can set the [`SuggestionStyle`].
pub fn multipart_suggestion_with_style(
&mut self,
msg: impl Into<SubdiagnosticMessage>,
@ -619,6 +719,7 @@ impl Diagnostic {
)
}
with_fn! { with_span_suggestion,
/// Prints out a message with a suggested edit of the code.
///
/// In case of short messages and a simple suggestion, rustc displays it as a label:
@ -651,9 +752,9 @@ impl Diagnostic {
SuggestionStyle::ShowCode,
);
self
}
} }
/// [`Diagnostic::span_suggestion()`] but you can set the [`SuggestionStyle`].
/// [`DiagnosticBuilder::span_suggestion()`] but you can set the [`SuggestionStyle`].
pub fn span_suggestion_with_style(
&mut self,
sp: Span,
@ -677,6 +778,7 @@ impl Diagnostic {
self
}
with_fn! { with_span_suggestion_verbose,
/// Always show the suggested change.
pub fn span_suggestion_verbose(
&mut self,
@ -693,10 +795,11 @@ impl Diagnostic {
SuggestionStyle::ShowAlways,
);
self
}
} }
with_fn! { with_span_suggestions,
/// Prints out a message with multiple suggested edits of the code.
/// See also [`Diagnostic::span_suggestion()`].
/// See also [`DiagnosticBuilder::span_suggestion()`].
pub fn span_suggestions(
&mut self,
sp: Span,
@ -711,9 +814,8 @@ impl Diagnostic {
applicability,
SuggestionStyle::ShowCode,
)
}
} }
/// [`Diagnostic::span_suggestions()`] but you can set the [`SuggestionStyle`].
pub fn span_suggestions_with_style(
&mut self,
sp: Span,
@ -743,7 +845,7 @@ impl Diagnostic {
/// Prints out a message with multiple suggested edits of the code, where each edit consists of
/// multiple parts.
/// See also [`Diagnostic::multipart_suggestion()`].
/// See also [`DiagnosticBuilder::multipart_suggestion()`].
pub fn multipart_suggestions(
&mut self,
msg: impl Into<SubdiagnosticMessage>,
@ -785,6 +887,7 @@ impl Diagnostic {
self
}
with_fn! { with_span_suggestion_short,
/// Prints out a message with a suggested edit of the code. If the suggestion is presented
/// inline, it will only show the message and not the suggestion.
///
@ -804,7 +907,7 @@ impl Diagnostic {
SuggestionStyle::HideCodeInline,
);
self
}
} }
/// Prints out a message for a suggestion without showing the suggested code.
///
@ -829,6 +932,7 @@ impl Diagnostic {
self
}
with_fn! { with_tool_only_span_suggestion,
/// Adds a suggestion to the JSON output that will not be shown in the CLI.
///
/// This is intended to be used for suggestions that are *very* obvious in what the changes
@ -849,7 +953,7 @@ impl Diagnostic {
SuggestionStyle::CompletelyHidden,
);
self
}
} }
/// Add a subdiagnostic from a type that implements `Subdiagnostic` (see
/// [rustc_macros::Subdiagnostic]). Performs eager translation of any translatable messages
@ -868,45 +972,45 @@ impl Diagnostic {
self
}
pub fn span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self {
with_fn! { with_span,
/// Add a span.
pub fn span(&mut self, sp: impl Into<MultiSpan>) -> &mut Self {
self.span = sp.into();
if let Some(span) = self.span.primary_span() {
self.sort_span = span;
}
self
}
} }
pub fn is_lint(&mut self, name: String, has_future_breakage: bool) -> &mut Self {
self.is_lint = Some(IsLint { name, has_future_breakage });
self
}
with_fn! { with_code,
/// Add an error code.
pub fn code(&mut self, code: ErrCode) -> &mut Self {
self.code = Some(code);
self
}
} }
with_fn! { with_primary_message,
/// Add a primary message.
pub fn primary_message(&mut self, msg: impl Into<DiagnosticMessage>) -> &mut Self {
self.messages[0] = (msg.into(), Style::NoStyle);
self
}
pub fn args(&self) -> impl Iterator<Item = DiagnosticArg<'_>> {
self.args.iter()
}
} }
with_fn! { with_arg,
/// Add an argument.
pub fn arg(
&mut self,
name: impl Into<DiagnosticArgName>,
arg: impl IntoDiagnosticArg,
) -> &mut Self {
self.args.insert(name.into(), arg.into_diagnostic_arg());
self.deref_mut().arg(name, arg);
self
}
pub fn replace_args(&mut self, args: FxIndexMap<DiagnosticArgName, DiagnosticArgValue>) {
self.args = args;
}
} }
/// Helper function that takes a `SubdiagnosticMessage` and returns a `DiagnosticMessage` by
/// combining it with the primary message of the diagnostic (if translatable, otherwise it just
@ -915,9 +1019,7 @@ impl Diagnostic {
&self,
attr: impl Into<SubdiagnosticMessage>,
) -> DiagnosticMessage {
let msg =
self.messages.iter().map(|(msg, _)| msg).next().expect("diagnostic with no messages");
msg.with_subdiagnostic_message(attr.into())
self.deref().subdiagnostic_message_to_diagnostic_message(attr)
}
/// Convenience function for internal use, clients should use one of the
@ -925,15 +1027,7 @@ impl Diagnostic {
///
/// Used by `proc_macro_server` for implementing `server::Diagnostic`.
pub fn sub(&mut self, level: Level, message: impl Into<SubdiagnosticMessage>, span: MultiSpan) {
let sub = SubDiagnostic {
level,
messages: vec![(
self.subdiagnostic_message_to_diagnostic_message(message),
Style::NoStyle,
)],
span,
};
self.children.push(sub);
self.deref_mut().sub(level, message, span);
}
/// Convenience function for internal use, clients should use one of the
@ -946,7 +1040,9 @@ impl Diagnostic {
let sub = SubDiagnostic { level, messages, span };
self.children.push(sub);
}
}
impl Diagnostic {
/// Fields used for Hash, and PartialEq trait
fn keys(
&self,