rust/compiler/rustc_error_messages/src/lib.rs
2023-07-30 13:18:33 +02:00

644 lines
25 KiB
Rust

#![feature(let_chains)]
#![feature(lazy_cell)]
#![feature(rustc_attrs)]
#![feature(type_alias_impl_trait)]
#![deny(rustc::untranslatable_diagnostic)]
#![deny(rustc::diagnostic_outside_of_impl)]
#[macro_use]
extern crate tracing;
use fluent_bundle::FluentResource;
use fluent_syntax::parser::ParserError;
use icu_provider_adapters::fallback::{LocaleFallbackProvider, LocaleFallbacker};
use rustc_data_structures::sync::{IntoDynSyncSend, Lrc};
use rustc_fluent_macro::fluent_messages;
use rustc_macros::{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};
#[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::{self, types::FluentType, FluentArgs, FluentError, FluentValue};
pub use unic_langid::{langid, LanguageIdentifier};
fluent_messages! { "../messages.ftl" }
pub type FluentBundle =
IntoDynSyncSend<fluent_bundle::bundle::FluentBundle<FluentResource, IntlLangMemoizer>>;
#[cfg(not(parallel_compiler))]
fn new_bundle(locales: Vec<LanguageIdentifier>) -> FluentBundle {
IntoDynSyncSend(fluent_bundle::bundle::FluentBundle::new(locales))
}
#[cfg(parallel_compiler)]
fn new_bundle(locales: Vec<LanguageIdentifier>) -> FluentBundle {
IntoDynSyncSend(fluent_bundle::bundle::FluentBundle::new_concurrent(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);
trace!(?requested_fallback_locale);
if requested_fallback_locale && additional_ftl_path.is_none() {
return Ok(None);
}
// 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]);
// Add convenience functions available to ftl authors.
register_functions(&mut bundle);
// 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 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))
}
fn register_functions(bundle: &mut FluentBundle) {
bundle
.add_function("STREQ", |positional, _named| match positional {
[FluentValue::String(a), FluentValue::String(b)] => format!("{}", (a == b)).into(),
_ => FluentValue::Error,
})
.expect("Failed to add a function to the 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", skip(resources))]
pub fn fallback_fluent_bundle(
resources: Vec<&'static str>,
with_directionality_markers: bool,
) -> LazyFallbackBundle {
Lrc::new(Lazy::new(move || {
let mut fallback_bundle = new_bundle(vec![langid!("en-US")]);
register_functions(&mut fallback_bundle);
// 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");
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 `Subdiagnostic` derive refer to Fluent identifiers directly.
#[rustc_diagnostic_item = "SubdiagnosticMessage"]
pub enum SubdiagnosticMessage {
/// Non-translatable diagnostic message.
Str(Cow<'static, str>),
/// Translatable message which has already been translated eagerly.
///
/// Some diagnostics have repeated subdiagnostics where the same interpolated variables would
/// be instantiated multiple times with different values. As translation normally happens
/// immediately prior to emission, after the diagnostic and subdiagnostic derive logic has run,
/// the setting of diagnostic arguments in the derived code will overwrite previous variable
/// values and only the final value will be set when translation occurs - resulting in
/// incorrect diagnostics. Eager translation results in translation for a subdiagnostic
/// happening immediately after the subdiagnostic derive's logic has been run. This variant
/// stores messages which have been translated eagerly.
Eager(Cow<'static, str>),
/// Identifier of a Fluent message. Instances of this variant are generated by the
/// `Subdiagnostic` 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),
}
impl From<String> for SubdiagnosticMessage {
fn from(s: String) -> Self {
SubdiagnosticMessage::Str(Cow::Owned(s))
}
}
impl From<&'static str> for SubdiagnosticMessage {
fn from(s: &'static str) -> Self {
SubdiagnosticMessage::Str(Cow::Borrowed(s))
}
}
impl From<Cow<'static, str>> for SubdiagnosticMessage {
fn from(s: Cow<'static, str>) -> Self {
SubdiagnosticMessage::Str(s)
}
}
/// 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.
Str(Cow<'static, str>),
/// Translatable message which has already been translated eagerly.
///
/// Some diagnostics have repeated subdiagnostics where the same interpolated variables would
/// be instantiated multiple times with different values. As translation normally happens
/// immediately prior to emission, after the diagnostic and subdiagnostic derive logic has run,
/// the setting of diagnostic arguments in the derived code will overwrite previous variable
/// values and only the final value will be set when translation occurs - resulting in
/// incorrect diagnostics. Eager translation results in translation for a subdiagnostic
/// happening immediately after the subdiagnostic derive's logic has been run. This variant
/// stores messages which have been translated eagerly.
Eager(Cow<'static, str>),
/// 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::Eager(s) => return DiagnosticMessage::Eager(s),
SubdiagnosticMessage::FluentIdentifier(id) => {
return DiagnosticMessage::FluentIdentifier(id, None);
}
SubdiagnosticMessage::FluentAttr(attr) => attr,
};
match self {
DiagnosticMessage::Str(s) => DiagnosticMessage::Str(s.clone()),
DiagnosticMessage::Eager(s) => DiagnosticMessage::Eager(s.clone()),
DiagnosticMessage::FluentIdentifier(id, _) => {
DiagnosticMessage::FluentIdentifier(id.clone(), Some(attr))
}
}
}
pub fn as_str(&self) -> Option<&str> {
match self {
DiagnosticMessage::Eager(s) | DiagnosticMessage::Str(s) => Some(s),
DiagnosticMessage::FluentIdentifier(_, _) => None,
}
}
}
impl From<String> for DiagnosticMessage {
fn from(s: String) -> Self {
DiagnosticMessage::Str(Cow::Owned(s))
}
}
impl From<&'static str> for DiagnosticMessage {
fn from(s: &'static str) -> Self {
DiagnosticMessage::Str(Cow::Borrowed(s))
}
}
impl From<Cow<'static, str>> for DiagnosticMessage {
fn from(s: Cow<'static, str>) -> Self {
DiagnosticMessage::Str(s)
}
}
/// A workaround for "good path" ICEs when formatting types in disabled lints.
///
/// Delays formatting until `.into(): DiagnosticMessage` is used.
pub struct DelayDm<F>(pub F);
impl<F: FnOnce() -> String> From<DelayDm<F>> for DiagnosticMessage {
fn from(DelayDm(f): DelayDm<F>) -> Self {
DiagnosticMessage::from(f())
}
}
/// 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::Eager(s) => SubdiagnosticMessage::Eager(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
}
pub fn pop_span_label(&mut self) -> Option<(Span, DiagnosticMessage)> {
self.span_labels.pop()
}
/// 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())
}
/// Clone this `MultiSpan` without keeping any of the span labels - sometimes a `MultiSpan` is
/// to be re-used in another diagnostic, but includes `span_labels` which have translated
/// messages. These translated messages would fail to translate without their diagnostic
/// arguments which are unlikely to be cloned alongside the `Span`.
pub fn clone_ignoring_labels(&self) -> Self {
Self { primary_spans: self.primary_spans.clone(), ..MultiSpan::new() }
}
}
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)
}
}
fn icu_locale_from_unic_langid(lang: LanguageIdentifier) -> Option<icu_locid::Locale> {
icu_locid::Locale::try_from_bytes(lang.to_string().as_bytes()).ok()
}
pub fn fluent_value_from_str_list_sep_by_and(l: Vec<Cow<'_, str>>) -> FluentValue<'_> {
// Fluent requires 'static value here for its AnyEq usages.
#[derive(Clone, PartialEq, Debug)]
struct FluentStrListSepByAnd(Vec<String>);
impl FluentType for FluentStrListSepByAnd {
fn duplicate(&self) -> Box<dyn FluentType + Send> {
Box::new(self.clone())
}
fn as_string(&self, intls: &intl_memoizer::IntlLangMemoizer) -> Cow<'static, str> {
let result = intls
.with_try_get::<MemoizableListFormatter, _, _>((), |list_formatter| {
list_formatter.format_to_string(self.0.iter())
})
.unwrap();
Cow::Owned(result)
}
#[cfg(not(parallel_compiler))]
fn as_string_threadsafe(
&self,
_intls: &intl_memoizer::concurrent::IntlLangMemoizer,
) -> Cow<'static, str> {
unreachable!("`as_string_threadsafe` is not used in non-parallel rustc")
}
#[cfg(parallel_compiler)]
fn as_string_threadsafe(
&self,
intls: &intl_memoizer::concurrent::IntlLangMemoizer,
) -> Cow<'static, str> {
let result = intls
.with_try_get::<MemoizableListFormatter, _, _>((), |list_formatter| {
list_formatter.format_to_string(self.0.iter())
})
.unwrap();
Cow::Owned(result)
}
}
struct MemoizableListFormatter(icu_list::ListFormatter);
impl std::ops::Deref for MemoizableListFormatter {
type Target = icu_list::ListFormatter;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl intl_memoizer::Memoizable for MemoizableListFormatter {
type Args = ();
type Error = ();
fn construct(lang: LanguageIdentifier, _args: Self::Args) -> Result<Self, Self::Error>
where
Self: Sized,
{
let baked_data_provider = rustc_baked_icu_data::baked_data_provider();
let locale_fallbacker =
LocaleFallbacker::try_new_with_any_provider(&baked_data_provider)
.expect("Failed to create fallback provider");
let data_provider =
LocaleFallbackProvider::new_with_fallbacker(baked_data_provider, locale_fallbacker);
let locale = icu_locale_from_unic_langid(lang)
.unwrap_or_else(|| rustc_baked_icu_data::supported_locales::EN);
let list_formatter =
icu_list::ListFormatter::try_new_and_with_length_with_any_provider(
&data_provider,
&locale.into(),
icu_list::ListLength::Wide,
)
.expect("Failed to create list formatter");
Ok(MemoizableListFormatter(list_formatter))
}
}
let l = l.into_iter().map(|x| x.into_owned()).collect();
FluentValue::Custom(Box::new(FluentStrListSepByAnd(l)))
}