diff options
Diffstat (limited to 'compiler/rustc_error_messages/src/lib.rs')
| -rw-r--r-- | compiler/rustc_error_messages/src/lib.rs | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs new file mode 100644 index 000000000..02bb04d98 --- /dev/null +++ b/compiler/rustc_error_messages/src/lib.rs @@ -0,0 +1,489 @@ +#![feature(let_chains)] +#![feature(once_cell)] +#![feature(rustc_attrs)] +#![feature(type_alias_impl_trait)] + +use fluent_bundle::FluentResource; +use fluent_syntax::parser::ParserError; +use rustc_data_structures::sync::Lrc; +use rustc_macros::{fluent_messages, Decodable, Encodable}; +use rustc_span::Span; +use std::borrow::Cow; +use std::error::Error; +use std::fmt; +use std::fs; +use std::io; +use std::path::{Path, PathBuf}; +use tracing::{instrument, trace}; + +#[cfg(not(parallel_compiler))] +use std::cell::LazyCell as Lazy; +#[cfg(parallel_compiler)] +use std::sync::LazyLock as Lazy; + +#[cfg(parallel_compiler)] +use intl_memoizer::concurrent::IntlLangMemoizer; +#[cfg(not(parallel_compiler))] +use intl_memoizer::IntlLangMemoizer; + +pub use fluent_bundle::{FluentArgs, FluentError, FluentValue}; +pub use unic_langid::{langid, LanguageIdentifier}; + +// Generates `DEFAULT_LOCALE_RESOURCES` static and `fluent_generated` module. +fluent_messages! { + borrowck => "../locales/en-US/borrowck.ftl", + builtin_macros => "../locales/en-US/builtin_macros.ftl", + const_eval => "../locales/en-US/const_eval.ftl", + expand => "../locales/en-US/expand.ftl", + lint => "../locales/en-US/lint.ftl", + parser => "../locales/en-US/parser.ftl", + passes => "../locales/en-US/passes.ftl", + privacy => "../locales/en-US/privacy.ftl", + typeck => "../locales/en-US/typeck.ftl", +} + +pub use fluent_generated::{self as fluent, DEFAULT_LOCALE_RESOURCES}; + +pub type FluentBundle = fluent_bundle::bundle::FluentBundle<FluentResource, IntlLangMemoizer>; + +#[cfg(parallel_compiler)] +fn new_bundle(locales: Vec<LanguageIdentifier>) -> FluentBundle { + FluentBundle::new_concurrent(locales) +} + +#[cfg(not(parallel_compiler))] +fn new_bundle(locales: Vec<LanguageIdentifier>) -> FluentBundle { + FluentBundle::new(locales) +} + +#[derive(Debug)] +pub enum TranslationBundleError { + /// Failed to read from `.ftl` file. + ReadFtl(io::Error), + /// Failed to parse contents of `.ftl` file. + ParseFtl(ParserError), + /// Failed to add `FluentResource` to `FluentBundle`. + AddResource(FluentError), + /// `$sysroot/share/locale/$locale` does not exist. + MissingLocale, + /// Cannot read directory entries of `$sysroot/share/locale/$locale`. + ReadLocalesDir(io::Error), + /// Cannot read directory entry of `$sysroot/share/locale/$locale`. + ReadLocalesDirEntry(io::Error), + /// `$sysroot/share/locale/$locale` is not a directory. + LocaleIsNotDir, +} + +impl fmt::Display for TranslationBundleError { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + TranslationBundleError::ReadFtl(e) => write!(f, "could not read ftl file: {}", e), + TranslationBundleError::ParseFtl(e) => { + write!(f, "could not parse ftl file: {}", e) + } + TranslationBundleError::AddResource(e) => write!(f, "failed to add resource: {}", e), + TranslationBundleError::MissingLocale => write!(f, "missing locale directory"), + TranslationBundleError::ReadLocalesDir(e) => { + write!(f, "could not read locales dir: {}", e) + } + TranslationBundleError::ReadLocalesDirEntry(e) => { + write!(f, "could not read locales dir entry: {}", e) + } + TranslationBundleError::LocaleIsNotDir => { + write!(f, "`$sysroot/share/locales/$locale` is not a directory") + } + } + } +} + +impl Error for TranslationBundleError { + fn source(&self) -> Option<&(dyn Error + 'static)> { + match self { + TranslationBundleError::ReadFtl(e) => Some(e), + TranslationBundleError::ParseFtl(e) => Some(e), + TranslationBundleError::AddResource(e) => Some(e), + TranslationBundleError::MissingLocale => None, + TranslationBundleError::ReadLocalesDir(e) => Some(e), + TranslationBundleError::ReadLocalesDirEntry(e) => Some(e), + TranslationBundleError::LocaleIsNotDir => None, + } + } +} + +impl From<(FluentResource, Vec<ParserError>)> for TranslationBundleError { + fn from((_, mut errs): (FluentResource, Vec<ParserError>)) -> Self { + TranslationBundleError::ParseFtl(errs.pop().expect("failed ftl parse with no errors")) + } +} + +impl From<Vec<FluentError>> for TranslationBundleError { + fn from(mut errs: Vec<FluentError>) -> Self { + TranslationBundleError::AddResource( + errs.pop().expect("failed adding resource to bundle with no errors"), + ) + } +} + +/// Returns Fluent bundle with the user's locale resources from +/// `$sysroot/share/locale/$requested_locale/*.ftl`. +/// +/// If `-Z additional-ftl-path` was provided, load that resource and add it to the bundle +/// (overriding any conflicting messages). +#[instrument(level = "trace")] +pub fn fluent_bundle( + mut user_provided_sysroot: Option<PathBuf>, + mut sysroot_candidates: Vec<PathBuf>, + requested_locale: Option<LanguageIdentifier>, + additional_ftl_path: Option<&Path>, + with_directionality_markers: bool, +) -> Result<Option<Lrc<FluentBundle>>, TranslationBundleError> { + if requested_locale.is_none() && additional_ftl_path.is_none() { + return Ok(None); + } + + let fallback_locale = langid!("en-US"); + let requested_fallback_locale = requested_locale.as_ref() == Some(&fallback_locale); + + // If there is only `-Z additional-ftl-path`, assume locale is "en-US", otherwise use user + // provided locale. + let locale = requested_locale.clone().unwrap_or(fallback_locale); + trace!(?locale); + let mut bundle = new_bundle(vec![locale]); + + // Fluent diagnostics can insert directionality isolation markers around interpolated variables + // indicating that there may be a shift from right-to-left to left-to-right text (or + // vice-versa). These are disabled because they are sometimes visible in the error output, but + // may be worth investigating in future (for example: if type names are left-to-right and the + // surrounding diagnostic messages are right-to-left, then these might be helpful). + bundle.set_use_isolating(with_directionality_markers); + + // If the user requests the default locale then don't try to load anything. + if !requested_fallback_locale && let Some(requested_locale) = requested_locale { + let mut found_resources = false; + for sysroot in user_provided_sysroot.iter_mut().chain(sysroot_candidates.iter_mut()) { + sysroot.push("share"); + sysroot.push("locale"); + sysroot.push(requested_locale.to_string()); + trace!(?sysroot); + + if !sysroot.exists() { + trace!("skipping"); + continue; + } + + if !sysroot.is_dir() { + return Err(TranslationBundleError::LocaleIsNotDir); + } + + for entry in sysroot.read_dir().map_err(TranslationBundleError::ReadLocalesDir)? { + let entry = entry.map_err(TranslationBundleError::ReadLocalesDirEntry)?; + let path = entry.path(); + trace!(?path); + if path.extension().and_then(|s| s.to_str()) != Some("ftl") { + trace!("skipping"); + continue; + } + + let resource_str = + fs::read_to_string(path).map_err(TranslationBundleError::ReadFtl)?; + let resource = + FluentResource::try_new(resource_str).map_err(TranslationBundleError::from)?; + trace!(?resource); + bundle.add_resource(resource).map_err(TranslationBundleError::from)?; + found_resources = true; + } + } + + if !found_resources { + return Err(TranslationBundleError::MissingLocale); + } + } + + if let Some(additional_ftl_path) = additional_ftl_path { + let resource_str = + fs::read_to_string(additional_ftl_path).map_err(TranslationBundleError::ReadFtl)?; + let resource = + FluentResource::try_new(resource_str).map_err(TranslationBundleError::from)?; + trace!(?resource); + bundle.add_resource_overriding(resource); + } + + let bundle = Lrc::new(bundle); + Ok(Some(bundle)) +} + +/// Type alias for the result of `fallback_fluent_bundle` - a reference-counted pointer to a lazily +/// evaluated fluent bundle. +pub type LazyFallbackBundle = Lrc<Lazy<FluentBundle, impl FnOnce() -> FluentBundle>>; + +/// Return the default `FluentBundle` with standard "en-US" diagnostic messages. +#[instrument(level = "trace")] +pub fn fallback_fluent_bundle( + resources: &'static [&'static str], + with_directionality_markers: bool, +) -> LazyFallbackBundle { + Lrc::new(Lazy::new(move || { + let mut fallback_bundle = new_bundle(vec![langid!("en-US")]); + // See comment in `fluent_bundle`. + fallback_bundle.set_use_isolating(with_directionality_markers); + + for resource in resources { + let resource = FluentResource::try_new(resource.to_string()) + .expect("failed to parse fallback fluent resource"); + trace!(?resource); + fallback_bundle.add_resource_overriding(resource); + } + + fallback_bundle + })) +} + +/// Identifier for the Fluent message/attribute corresponding to a diagnostic message. +type FluentId = Cow<'static, str>; + +/// Abstraction over a message in a subdiagnostic (i.e. label, note, help, etc) to support both +/// translatable and non-translatable diagnostic messages. +/// +/// Translatable messages for subdiagnostics are typically attributes attached to a larger Fluent +/// message so messages of this type must be combined with a `DiagnosticMessage` (using +/// `DiagnosticMessage::with_subdiagnostic_message`) before rendering. However, subdiagnostics from +/// the `SessionSubdiagnostic` derive refer to Fluent identifiers directly. +#[rustc_diagnostic_item = "SubdiagnosticMessage"] +pub enum SubdiagnosticMessage { + /// Non-translatable diagnostic message. + // FIXME(davidtwco): can a `Cow<'static, str>` be used here? + Str(String), + /// Identifier of a Fluent message. Instances of this variant are generated by the + /// `SessionSubdiagnostic` derive. + FluentIdentifier(FluentId), + /// Attribute of a Fluent message. Needs to be combined with a Fluent identifier to produce an + /// actual translated message. Instances of this variant are generated by the `fluent_messages` + /// macro. + /// + /// <https://projectfluent.org/fluent/guide/attributes.html> + FluentAttr(FluentId), +} + +/// `From` impl that enables existing diagnostic calls to functions which now take +/// `impl Into<SubdiagnosticMessage>` to continue to work as before. +impl<S: Into<String>> From<S> for SubdiagnosticMessage { + fn from(s: S) -> Self { + SubdiagnosticMessage::Str(s.into()) + } +} + +/// Abstraction over a message in a diagnostic to support both translatable and non-translatable +/// diagnostic messages. +/// +/// Intended to be removed once diagnostics are entirely translatable. +#[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)] +#[rustc_diagnostic_item = "DiagnosticMessage"] +pub enum DiagnosticMessage { + /// Non-translatable diagnostic message. + // FIXME(davidtwco): can a `Cow<'static, str>` be used here? + Str(String), + /// Identifier for a Fluent message (with optional attribute) corresponding to the diagnostic + /// message. + /// + /// <https://projectfluent.org/fluent/guide/hello.html> + /// <https://projectfluent.org/fluent/guide/attributes.html> + FluentIdentifier(FluentId, Option<FluentId>), +} + +impl DiagnosticMessage { + /// Given a `SubdiagnosticMessage` which may contain a Fluent attribute, create a new + /// `DiagnosticMessage` that combines that attribute with the Fluent identifier of `self`. + /// + /// - If the `SubdiagnosticMessage` is non-translatable then return the message as a + /// `DiagnosticMessage`. + /// - If `self` is non-translatable then return `self`'s message. + pub fn with_subdiagnostic_message(&self, sub: SubdiagnosticMessage) -> Self { + let attr = match sub { + SubdiagnosticMessage::Str(s) => return DiagnosticMessage::Str(s), + SubdiagnosticMessage::FluentIdentifier(id) => { + return DiagnosticMessage::FluentIdentifier(id, None); + } + SubdiagnosticMessage::FluentAttr(attr) => attr, + }; + + match self { + DiagnosticMessage::Str(s) => DiagnosticMessage::Str(s.clone()), + DiagnosticMessage::FluentIdentifier(id, _) => { + DiagnosticMessage::FluentIdentifier(id.clone(), Some(attr)) + } + } + } + + /// Returns the `String` contained within the `DiagnosticMessage::Str` variant, assuming that + /// this diagnostic message is of the legacy, non-translatable variety. Panics if this + /// assumption does not hold. + /// + /// Don't use this - it exists to support some places that do comparison with diagnostic + /// strings. + pub fn expect_str(&self) -> &str { + match self { + DiagnosticMessage::Str(s) => s, + _ => panic!("expected non-translatable diagnostic message"), + } + } +} + +/// `From` impl that enables existing diagnostic calls to functions which now take +/// `impl Into<DiagnosticMessage>` to continue to work as before. +impl<S: Into<String>> From<S> for DiagnosticMessage { + fn from(s: S) -> Self { + DiagnosticMessage::Str(s.into()) + } +} + +/// Translating *into* a subdiagnostic message from a diagnostic message is a little strange - but +/// the subdiagnostic functions (e.g. `span_label`) take a `SubdiagnosticMessage` and the +/// subdiagnostic derive refers to typed identifiers that are `DiagnosticMessage`s, so need to be +/// able to convert between these, as much as they'll be converted back into `DiagnosticMessage` +/// using `with_subdiagnostic_message` eventually. Don't use this other than for the derive. +impl Into<SubdiagnosticMessage> for DiagnosticMessage { + fn into(self) -> SubdiagnosticMessage { + match self { + DiagnosticMessage::Str(s) => SubdiagnosticMessage::Str(s), + DiagnosticMessage::FluentIdentifier(id, None) => { + SubdiagnosticMessage::FluentIdentifier(id) + } + // There isn't really a sensible behaviour for this because it loses information but + // this is the most sensible of the behaviours. + DiagnosticMessage::FluentIdentifier(_, Some(attr)) => { + SubdiagnosticMessage::FluentAttr(attr) + } + } + } +} + +/// A span together with some additional data. +#[derive(Clone, Debug)] +pub struct SpanLabel { + /// The span we are going to include in the final snippet. + pub span: Span, + + /// Is this a primary span? This is the "locus" of the message, + /// and is indicated with a `^^^^` underline, versus `----`. + pub is_primary: bool, + + /// What label should we attach to this span (if any)? + pub label: Option<DiagnosticMessage>, +} + +/// A collection of `Span`s. +/// +/// Spans have two orthogonal attributes: +/// +/// - They can be *primary spans*. In this case they are the locus of +/// the error, and would be rendered with `^^^`. +/// - They can have a *label*. In this case, the label is written next +/// to the mark in the snippet when we render. +#[derive(Clone, Debug, Hash, PartialEq, Eq, Encodable, Decodable)] +pub struct MultiSpan { + primary_spans: Vec<Span>, + span_labels: Vec<(Span, DiagnosticMessage)>, +} + +impl MultiSpan { + #[inline] + pub fn new() -> MultiSpan { + MultiSpan { primary_spans: vec![], span_labels: vec![] } + } + + pub fn from_span(primary_span: Span) -> MultiSpan { + MultiSpan { primary_spans: vec![primary_span], span_labels: vec![] } + } + + pub fn from_spans(mut vec: Vec<Span>) -> MultiSpan { + vec.sort(); + MultiSpan { primary_spans: vec, span_labels: vec![] } + } + + pub fn push_span_label(&mut self, span: Span, label: impl Into<DiagnosticMessage>) { + self.span_labels.push((span, label.into())); + } + + /// Selects the first primary span (if any). + pub fn primary_span(&self) -> Option<Span> { + self.primary_spans.first().cloned() + } + + /// Returns all primary spans. + pub fn primary_spans(&self) -> &[Span] { + &self.primary_spans + } + + /// Returns `true` if any of the primary spans are displayable. + pub fn has_primary_spans(&self) -> bool { + !self.is_dummy() + } + + /// Returns `true` if this contains only a dummy primary span with any hygienic context. + pub fn is_dummy(&self) -> bool { + self.primary_spans.iter().all(|sp| sp.is_dummy()) + } + + /// Replaces all occurrences of one Span with another. Used to move `Span`s in areas that don't + /// display well (like std macros). Returns whether replacements occurred. + pub fn replace(&mut self, before: Span, after: Span) -> bool { + let mut replacements_occurred = false; + for primary_span in &mut self.primary_spans { + if *primary_span == before { + *primary_span = after; + replacements_occurred = true; + } + } + for span_label in &mut self.span_labels { + if span_label.0 == before { + span_label.0 = after; + replacements_occurred = true; + } + } + replacements_occurred + } + + /// Returns the strings to highlight. We always ensure that there + /// is an entry for each of the primary spans -- for each primary + /// span `P`, if there is at least one label with span `P`, we return + /// those labels (marked as primary). But otherwise we return + /// `SpanLabel` instances with empty labels. + pub fn span_labels(&self) -> Vec<SpanLabel> { + let is_primary = |span| self.primary_spans.contains(&span); + + let mut span_labels = self + .span_labels + .iter() + .map(|&(span, ref label)| SpanLabel { + span, + is_primary: is_primary(span), + label: Some(label.clone()), + }) + .collect::<Vec<_>>(); + + for &span in &self.primary_spans { + if !span_labels.iter().any(|sl| sl.span == span) { + span_labels.push(SpanLabel { span, is_primary: true, label: None }); + } + } + + span_labels + } + + /// Returns `true` if any of the span labels is displayable. + pub fn has_span_labels(&self) -> bool { + self.span_labels.iter().any(|(sp, _)| !sp.is_dummy()) + } +} + +impl From<Span> for MultiSpan { + fn from(span: Span) -> MultiSpan { + MultiSpan::from_span(span) + } +} + +impl From<Vec<Span>> for MultiSpan { + fn from(spans: Vec<Span>) -> MultiSpan { + MultiSpan::from_spans(spans) + } +} |