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-rw-r--r--compiler/rustc_errors/Cargo.toml27
-rw-r--r--compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs215
-rw-r--r--compiler/rustc_errors/src/diagnostic.rs1016
-rw-r--r--compiler/rustc_errors/src/diagnostic_builder.rs616
-rw-r--r--compiler/rustc_errors/src/emitter.rs2687
-rw-r--r--compiler/rustc_errors/src/json.rs561
-rw-r--r--compiler/rustc_errors/src/json/tests.rs204
-rw-r--r--compiler/rustc_errors/src/lib.rs1589
-rw-r--r--compiler/rustc_errors/src/lock.rs93
-rw-r--r--compiler/rustc_errors/src/registry.rs25
-rw-r--r--compiler/rustc_errors/src/snippet.rs179
-rw-r--r--compiler/rustc_errors/src/styled_buffer.rs151
12 files changed, 7363 insertions, 0 deletions
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
new file mode 100644
index 000000000..7d7e92c52
--- /dev/null
+++ b/compiler/rustc_errors/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name = "rustc_errors"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+doctest = false
+
+[dependencies]
+tracing = "0.1"
+rustc_error_messages = { path = "../rustc_error_messages" }
+rustc_serialize = { path = "../rustc_serialize" }
+rustc_span = { path = "../rustc_span" }
+rustc_macros = { path = "../rustc_macros" }
+rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_hir = { path = "../rustc_hir" }
+rustc_lint_defs = { path = "../rustc_lint_defs" }
+unicode-width = "0.1.4"
+atty = "0.2"
+termcolor = "1.0"
+annotate-snippets = "0.8.0"
+termize = "0.1.1"
+serde = { version = "1.0.125", features = ["derive"] }
+serde_json = "1.0.59"
+
+[target.'cfg(windows)'.dependencies]
+winapi = { version = "0.3", features = ["handleapi", "synchapi", "winbase"] }
diff --git a/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs
new file mode 100644
index 000000000..0fcd61d1e
--- /dev/null
+++ b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs
@@ -0,0 +1,215 @@
+//! Emit diagnostics using the `annotate-snippets` library
+//!
+//! This is the equivalent of `./emitter.rs` but making use of the
+//! [`annotate-snippets`][annotate_snippets] library instead of building the output ourselves.
+//!
+//! [annotate_snippets]: https://docs.rs/crate/annotate-snippets/
+
+use crate::emitter::FileWithAnnotatedLines;
+use crate::snippet::Line;
+use crate::{
+ CodeSuggestion, Diagnostic, DiagnosticId, DiagnosticMessage, Emitter, FluentBundle,
+ LazyFallbackBundle, Level, MultiSpan, Style, SubDiagnostic,
+};
+use annotate_snippets::display_list::{DisplayList, FormatOptions};
+use annotate_snippets::snippet::*;
+use rustc_data_structures::sync::Lrc;
+use rustc_error_messages::FluentArgs;
+use rustc_span::source_map::SourceMap;
+use rustc_span::SourceFile;
+
+/// Generates diagnostics using annotate-snippet
+pub struct AnnotateSnippetEmitterWriter {
+ source_map: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+
+ /// If true, hides the longer explanation text
+ short_message: bool,
+ /// If true, will normalize line numbers with `LL` to prevent noise in UI test diffs.
+ ui_testing: bool,
+
+ macro_backtrace: bool,
+}
+
+impl Emitter for AnnotateSnippetEmitterWriter {
+ /// The entry point for the diagnostics generation
+ fn emit_diagnostic(&mut self, diag: &Diagnostic) {
+ let fluent_args = self.to_fluent_args(diag.args());
+
+ let mut children = diag.children.clone();
+ let (mut primary_span, suggestions) = self.primary_span_formatted(&diag, &fluent_args);
+
+ self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
+ &self.source_map,
+ &mut primary_span,
+ &mut children,
+ &diag.level,
+ self.macro_backtrace,
+ );
+
+ self.emit_messages_default(
+ &diag.level,
+ &diag.message,
+ &fluent_args,
+ &diag.code,
+ &primary_span,
+ &children,
+ &suggestions,
+ );
+ }
+
+ fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+ self.source_map.as_ref()
+ }
+
+ fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+ self.fluent_bundle.as_ref()
+ }
+
+ fn fallback_fluent_bundle(&self) -> &FluentBundle {
+ &**self.fallback_bundle
+ }
+
+ fn should_show_explain(&self) -> bool {
+ !self.short_message
+ }
+}
+
+/// Provides the source string for the given `line` of `file`
+fn source_string(file: Lrc<SourceFile>, line: &Line) -> String {
+ file.get_line(line.line_index - 1).map(|a| a.to_string()).unwrap_or_default()
+}
+
+/// Maps `Diagnostic::Level` to `snippet::AnnotationType`
+fn annotation_type_for_level(level: Level) -> AnnotationType {
+ match level {
+ Level::Bug | Level::DelayedBug | Level::Fatal | Level::Error { .. } => {
+ AnnotationType::Error
+ }
+ Level::Warning(_) => AnnotationType::Warning,
+ Level::Note | Level::OnceNote => AnnotationType::Note,
+ Level::Help => AnnotationType::Help,
+ // FIXME(#59346): Not sure how to map this level
+ Level::FailureNote => AnnotationType::Error,
+ Level::Allow => panic!("Should not call with Allow"),
+ Level::Expect(_) => panic!("Should not call with Expect"),
+ }
+}
+
+impl AnnotateSnippetEmitterWriter {
+ pub fn new(
+ source_map: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ short_message: bool,
+ macro_backtrace: bool,
+ ) -> Self {
+ Self {
+ source_map,
+ fluent_bundle,
+ fallback_bundle,
+ short_message,
+ ui_testing: false,
+ macro_backtrace,
+ }
+ }
+
+ /// Allows to modify `Self` to enable or disable the `ui_testing` flag.
+ ///
+ /// If this is set to true, line numbers will be normalized as `LL` in the output.
+ pub fn ui_testing(mut self, ui_testing: bool) -> Self {
+ self.ui_testing = ui_testing;
+ self
+ }
+
+ fn emit_messages_default(
+ &mut self,
+ level: &Level,
+ messages: &[(DiagnosticMessage, Style)],
+ args: &FluentArgs<'_>,
+ code: &Option<DiagnosticId>,
+ msp: &MultiSpan,
+ _children: &[SubDiagnostic],
+ _suggestions: &[CodeSuggestion],
+ ) {
+ let message = self.translate_messages(messages, args);
+ if let Some(source_map) = &self.source_map {
+ // Make sure our primary file comes first
+ let primary_lo = if let Some(ref primary_span) = msp.primary_span().as_ref() {
+ if primary_span.is_dummy() {
+ // FIXME(#59346): Not sure when this is the case and what
+ // should be done if it happens
+ return;
+ } else {
+ source_map.lookup_char_pos(primary_span.lo())
+ }
+ } else {
+ // FIXME(#59346): Not sure when this is the case and what
+ // should be done if it happens
+ return;
+ };
+ let mut annotated_files = FileWithAnnotatedLines::collect_annotations(self, args, msp);
+ if let Ok(pos) =
+ annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
+ {
+ annotated_files.swap(0, pos);
+ }
+ // owned: line source, line index, annotations
+ type Owned = (String, usize, Vec<crate::snippet::Annotation>);
+ let filename = source_map.filename_for_diagnostics(&primary_lo.file.name);
+ let origin = filename.to_string_lossy();
+ let annotated_files: Vec<Owned> = annotated_files
+ .into_iter()
+ .flat_map(|annotated_file| {
+ let file = annotated_file.file;
+ annotated_file
+ .lines
+ .into_iter()
+ .map(|line| {
+ (source_string(file.clone(), &line), line.line_index, line.annotations)
+ })
+ .collect::<Vec<Owned>>()
+ })
+ .collect();
+ let snippet = Snippet {
+ title: Some(Annotation {
+ label: Some(&message),
+ id: code.as_ref().map(|c| match c {
+ DiagnosticId::Error(val) | DiagnosticId::Lint { name: val, .. } => {
+ val.as_str()
+ }
+ }),
+ annotation_type: annotation_type_for_level(*level),
+ }),
+ footer: vec![],
+ opt: FormatOptions { color: true, anonymized_line_numbers: self.ui_testing },
+ slices: annotated_files
+ .iter()
+ .map(|(source, line_index, annotations)| {
+ Slice {
+ source,
+ line_start: *line_index,
+ origin: Some(&origin),
+ // FIXME(#59346): Not really sure when `fold` should be true or false
+ fold: false,
+ annotations: annotations
+ .iter()
+ .map(|annotation| SourceAnnotation {
+ range: (annotation.start_col, annotation.end_col),
+ label: annotation.label.as_deref().unwrap_or_default(),
+ annotation_type: annotation_type_for_level(*level),
+ })
+ .collect(),
+ }
+ })
+ .collect(),
+ };
+ // FIXME(#59346): Figure out if we can _always_ print to stderr or not.
+ // `emitter.rs` has the `Destination` enum that lists various possible output
+ // destinations.
+ eprintln!("{}", DisplayList::from(snippet))
+ }
+ // FIXME(#59346): Is it ok to return None if there's no source_map?
+ }
+}
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
new file mode 100644
index 000000000..17e6c9e95
--- /dev/null
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -0,0 +1,1016 @@
+use crate::snippet::Style;
+use crate::{
+ CodeSuggestion, DiagnosticMessage, EmissionGuarantee, Level, LintDiagnosticBuilder, MultiSpan,
+ SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
+};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_error_messages::FluentValue;
+use rustc_hir as hir;
+use rustc_lint_defs::{Applicability, LintExpectationId};
+use rustc_span::edition::LATEST_STABLE_EDITION;
+use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::{edition::Edition, Span, DUMMY_SP};
+use std::borrow::Cow;
+use std::fmt;
+use std::hash::{Hash, Hasher};
+
+/// Error type for `Diagnostic`'s `suggestions` field, indicating that
+/// `.disable_suggestions()` was called on the `Diagnostic`.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
+pub struct SuggestionsDisabled;
+
+/// Simplified version of `FluentArg` that can implement `Encodable` and `Decodable`. Collection of
+/// `DiagnosticArg` are converted to `FluentArgs` (consuming the collection) at the start of
+/// diagnostic emission.
+pub type DiagnosticArg<'source> = (Cow<'source, str>, DiagnosticArgValue<'source>);
+
+/// Simplified version of `FluentValue` that can implement `Encodable` and `Decodable`. Converted
+/// to a `FluentValue` by the emitter to be used in diagnostic translation.
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
+pub enum DiagnosticArgValue<'source> {
+ Str(Cow<'source, str>),
+ Number(usize),
+}
+
+/// Converts a value of a type into a `DiagnosticArg` (typically a field of a `SessionDiagnostic`
+/// struct). Implemented as a custom trait rather than `From` so that it is implemented on the type
+/// being converted rather than on `DiagnosticArgValue`, which enables types from other `rustc_*`
+/// crates to implement this.
+pub trait IntoDiagnosticArg {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static>;
+}
+
+pub struct DiagnosticArgFromDisplay<'a>(pub &'a dyn fmt::Display);
+
+impl IntoDiagnosticArg for DiagnosticArgFromDisplay<'_> {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ self.0.to_string().into_diagnostic_arg()
+ }
+}
+
+impl<'a> From<&'a dyn fmt::Display> for DiagnosticArgFromDisplay<'a> {
+ fn from(t: &'a dyn fmt::Display) -> Self {
+ DiagnosticArgFromDisplay(t)
+ }
+}
+
+impl<'a, T: fmt::Display> From<&'a T> for DiagnosticArgFromDisplay<'a> {
+ fn from(t: &'a T) -> Self {
+ DiagnosticArgFromDisplay(t)
+ }
+}
+
+macro_rules! into_diagnostic_arg_using_display {
+ ($( $ty:ty ),+ $(,)?) => {
+ $(
+ impl IntoDiagnosticArg for $ty {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ self.to_string().into_diagnostic_arg()
+ }
+ }
+ )+
+ }
+}
+
+into_diagnostic_arg_using_display!(
+ i8,
+ u8,
+ i16,
+ u16,
+ i32,
+ u32,
+ i64,
+ u64,
+ i128,
+ u128,
+ std::num::NonZeroU32,
+ hir::Target,
+ Edition,
+ Ident,
+);
+
+impl IntoDiagnosticArg for bool {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ if self {
+ DiagnosticArgValue::Str(Cow::Borrowed("true"))
+ } else {
+ DiagnosticArgValue::Str(Cow::Borrowed("false"))
+ }
+ }
+}
+
+impl IntoDiagnosticArg for char {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ DiagnosticArgValue::Str(Cow::Owned(format!("{:?}", self)))
+ }
+}
+
+impl IntoDiagnosticArg for Symbol {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ self.to_ident_string().into_diagnostic_arg()
+ }
+}
+
+impl<'a> IntoDiagnosticArg for &'a str {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ self.to_string().into_diagnostic_arg()
+ }
+}
+
+impl IntoDiagnosticArg for String {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ DiagnosticArgValue::Str(Cow::Owned(self))
+ }
+}
+
+impl IntoDiagnosticArg for usize {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ DiagnosticArgValue::Number(self)
+ }
+}
+
+impl<'source> Into<FluentValue<'source>> for DiagnosticArgValue<'source> {
+ fn into(self) -> FluentValue<'source> {
+ match self {
+ DiagnosticArgValue::Str(s) => From::from(s),
+ DiagnosticArgValue::Number(n) => From::from(n),
+ }
+ }
+}
+
+impl IntoDiagnosticArg for hir::ConstContext {
+ fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+ DiagnosticArgValue::Str(Cow::Borrowed(match self {
+ hir::ConstContext::ConstFn => "constant function",
+ hir::ConstContext::Static(_) => "static",
+ hir::ConstContext::Const => "constant",
+ }))
+ }
+}
+
+/// Trait implemented by error types. This should not be implemented manually. Instead, use
+/// `#[derive(SessionSubdiagnostic)]` -- see [rustc_macros::SessionSubdiagnostic].
+#[rustc_diagnostic_item = "AddSubdiagnostic"]
+pub trait AddSubdiagnostic {
+ /// Add a subdiagnostic to an existing diagnostic.
+ fn add_to_diagnostic(self, diag: &mut Diagnostic);
+}
+
+/// Trait implemented by lint types. This should not be implemented manually. Instead, use
+/// `#[derive(LintDiagnostic)]` -- see [rustc_macros::LintDiagnostic].
+#[rustc_diagnostic_item = "DecorateLint"]
+pub trait DecorateLint<'a, G: EmissionGuarantee> {
+ /// Decorate and emit a lint.
+ fn decorate_lint(self, diag: LintDiagnosticBuilder<'a, G>);
+}
+
+#[must_use]
+#[derive(Clone, Debug, Encodable, Decodable)]
+pub struct Diagnostic {
+ // NOTE(eddyb) this is private to disallow arbitrary after-the-fact changes,
+ // outside of what methods in this crate themselves allow.
+ pub(crate) level: Level,
+
+ pub message: Vec<(DiagnosticMessage, Style)>,
+ pub code: Option<DiagnosticId>,
+ pub span: MultiSpan,
+ pub children: Vec<SubDiagnostic>,
+ pub suggestions: Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
+ args: Vec<DiagnosticArg<'static>>,
+
+ /// This is not used for highlighting or rendering any error message. Rather, it can be used
+ /// as a sort key to sort a buffer of diagnostics. By default, it is the primary span of
+ /// `span` if there is one. Otherwise, it is `DUMMY_SP`.
+ pub sort_span: Span,
+
+ /// If diagnostic is from Lint, custom hash function ignores notes
+ /// otherwise hash is based on the all the fields
+ pub is_lint: bool,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
+pub enum DiagnosticId {
+ Error(String),
+ Lint { name: String, has_future_breakage: bool, is_force_warn: bool },
+}
+
+/// A "sub"-diagnostic attached to a parent diagnostic.
+/// For example, a note attached to an error.
+#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
+pub struct SubDiagnostic {
+ pub level: Level,
+ pub message: Vec<(DiagnosticMessage, Style)>,
+ pub span: MultiSpan,
+ pub render_span: Option<MultiSpan>,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct DiagnosticStyledString(pub Vec<StringPart>);
+
+impl DiagnosticStyledString {
+ pub fn new() -> DiagnosticStyledString {
+ DiagnosticStyledString(vec![])
+ }
+ pub fn push_normal<S: Into<String>>(&mut self, t: S) {
+ self.0.push(StringPart::Normal(t.into()));
+ }
+ pub fn push_highlighted<S: Into<String>>(&mut self, t: S) {
+ self.0.push(StringPart::Highlighted(t.into()));
+ }
+ pub fn push<S: Into<String>>(&mut self, t: S, highlight: bool) {
+ if highlight {
+ self.push_highlighted(t);
+ } else {
+ self.push_normal(t);
+ }
+ }
+ pub fn normal<S: Into<String>>(t: S) -> DiagnosticStyledString {
+ DiagnosticStyledString(vec![StringPart::Normal(t.into())])
+ }
+
+ pub fn highlighted<S: Into<String>>(t: S) -> DiagnosticStyledString {
+ DiagnosticStyledString(vec![StringPart::Highlighted(t.into())])
+ }
+
+ pub fn content(&self) -> String {
+ self.0.iter().map(|x| x.content()).collect::<String>()
+ }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum StringPart {
+ Normal(String),
+ Highlighted(String),
+}
+
+impl StringPart {
+ pub fn content(&self) -> &str {
+ match self {
+ &StringPart::Normal(ref s) | &StringPart::Highlighted(ref s) => s,
+ }
+ }
+}
+
+impl Diagnostic {
+ pub fn new<M: Into<DiagnosticMessage>>(level: Level, message: M) -> Self {
+ Diagnostic::new_with_code(level, None, message)
+ }
+
+ pub fn new_with_code<M: Into<DiagnosticMessage>>(
+ level: Level,
+ code: Option<DiagnosticId>,
+ message: M,
+ ) -> Self {
+ Diagnostic {
+ level,
+ message: vec![(message.into(), Style::NoStyle)],
+ code,
+ span: MultiSpan::new(),
+ children: vec![],
+ suggestions: Ok(vec![]),
+ args: vec![],
+ sort_span: DUMMY_SP,
+ is_lint: false,
+ }
+ }
+
+ #[inline(always)]
+ pub fn level(&self) -> Level {
+ self.level
+ }
+
+ pub fn is_error(&self) -> bool {
+ match self.level {
+ Level::Bug
+ | Level::DelayedBug
+ | Level::Fatal
+ | Level::Error { .. }
+ | Level::FailureNote => true,
+
+ Level::Warning(_)
+ | Level::Note
+ | Level::OnceNote
+ | Level::Help
+ | Level::Allow
+ | Level::Expect(_) => false,
+ }
+ }
+
+ pub fn update_unstable_expectation_id(
+ &mut self,
+ unstable_to_stable: &FxHashMap<LintExpectationId, LintExpectationId>,
+ ) {
+ if let Level::Expect(expectation_id) | Level::Warning(Some(expectation_id)) =
+ &mut self.level
+ {
+ if expectation_id.is_stable() {
+ return;
+ }
+
+ // The unstable to stable map only maps the unstable `AttrId` to a stable `HirId` with an attribute index.
+ // The lint index inside the attribute is manually transferred here.
+ let lint_index = expectation_id.get_lint_index();
+ expectation_id.set_lint_index(None);
+ let mut stable_id = *unstable_to_stable
+ .get(&expectation_id)
+ .expect("each unstable `LintExpectationId` must have a matching stable id");
+
+ stable_id.set_lint_index(lint_index);
+ *expectation_id = stable_id;
+ }
+ }
+
+ pub fn has_future_breakage(&self) -> bool {
+ match self.code {
+ Some(DiagnosticId::Lint { has_future_breakage, .. }) => has_future_breakage,
+ _ => false,
+ }
+ }
+
+ pub fn is_force_warn(&self) -> bool {
+ match self.code {
+ Some(DiagnosticId::Lint { is_force_warn, .. }) => is_force_warn,
+ _ => false,
+ }
+ }
+
+ /// Delay emission of this diagnostic as a bug.
+ ///
+ /// This can be useful in contexts where an error indicates a bug but
+ /// typically this only happens when other compilation errors have already
+ /// happened. In those cases this can be used to defer emission of this
+ /// diagnostic as a bug in the compiler only if no other errors have been
+ /// emitted.
+ ///
+ /// In the meantime, though, callsites are required to deal with the "bug"
+ /// locally in whichever way makes the most sense.
+ #[track_caller]
+ pub fn downgrade_to_delayed_bug(&mut self) -> &mut Self {
+ assert!(
+ self.is_error(),
+ "downgrade_to_delayed_bug: cannot downgrade {:?} to DelayedBug: not an error",
+ self.level
+ );
+ self.level = Level::DelayedBug;
+
+ self
+ }
+
+ /// Adds a span/label to be included in the resulting snippet.
+ ///
+ /// This is pushed onto the [`MultiSpan`] that was created when the diagnostic
+ /// was first built. That means it will be shown together with the original
+ /// span/label, *not* a span added by one of the `span_{note,warn,help,suggestions}` methods.
+ ///
+ /// This span is *not* considered a ["primary span"][`MultiSpan`]; only
+ /// the `Span` supplied when creating the diagnostic is 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));
+ self
+ }
+
+ /// 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: impl AsRef<str>,
+ ) -> &mut Self {
+ let label = label.as_ref();
+ for span in spans {
+ self.span_label(span, label);
+ }
+ self
+ }
+
+ pub fn replace_span_with(&mut self, after: Span) -> &mut Self {
+ let before = self.span.clone();
+ self.set_span(after);
+ for span_label in before.span_labels() {
+ if let Some(label) = span_label.label {
+ self.span.push_span_label(after, label);
+ }
+ }
+ self
+ }
+
+ pub fn note_expected_found(
+ &mut self,
+ expected_label: &dyn fmt::Display,
+ expected: DiagnosticStyledString,
+ found_label: &dyn fmt::Display,
+ found: DiagnosticStyledString,
+ ) -> &mut Self {
+ self.note_expected_found_extra(expected_label, expected, found_label, found, &"", &"")
+ }
+
+ pub fn note_unsuccessful_coercion(
+ &mut self,
+ expected: DiagnosticStyledString,
+ found: DiagnosticStyledString,
+ ) -> &mut Self {
+ let mut msg: Vec<_> = vec![("required when trying to coerce from type `", Style::NoStyle)];
+ msg.extend(expected.0.iter().map(|x| match *x {
+ StringPart::Normal(ref s) => (s.as_str(), Style::NoStyle),
+ StringPart::Highlighted(ref s) => (s.as_str(), Style::Highlight),
+ }));
+ msg.push(("` to type '", Style::NoStyle));
+ msg.extend(found.0.iter().map(|x| match *x {
+ StringPart::Normal(ref s) => (s.as_str(), Style::NoStyle),
+ StringPart::Highlighted(ref s) => (s.as_str(), Style::Highlight),
+ }));
+ msg.push(("`", Style::NoStyle));
+
+ // For now, just attach these as notes
+ self.highlighted_note(msg);
+ self
+ }
+
+ pub fn note_expected_found_extra(
+ &mut self,
+ expected_label: &dyn fmt::Display,
+ expected: DiagnosticStyledString,
+ found_label: &dyn fmt::Display,
+ found: DiagnosticStyledString,
+ expected_extra: &dyn fmt::Display,
+ found_extra: &dyn fmt::Display,
+ ) -> &mut Self {
+ let expected_label = expected_label.to_string();
+ let expected_label = if expected_label.is_empty() {
+ "expected".to_string()
+ } else {
+ format!("expected {}", expected_label)
+ };
+ let found_label = found_label.to_string();
+ let found_label = if found_label.is_empty() {
+ "found".to_string()
+ } else {
+ format!("found {}", found_label)
+ };
+ let (found_padding, expected_padding) = if expected_label.len() > found_label.len() {
+ (expected_label.len() - found_label.len(), 0)
+ } else {
+ (0, found_label.len() - expected_label.len())
+ };
+ let mut msg: Vec<_> =
+ vec![(format!("{}{} `", " ".repeat(expected_padding), expected_label), Style::NoStyle)];
+ msg.extend(expected.0.iter().map(|x| match *x {
+ StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle),
+ StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight),
+ }));
+ msg.push((format!("`{}\n", expected_extra), Style::NoStyle));
+ msg.push((format!("{}{} `", " ".repeat(found_padding), found_label), Style::NoStyle));
+ msg.extend(found.0.iter().map(|x| match *x {
+ StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle),
+ StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight),
+ }));
+ msg.push((format!("`{}", found_extra), Style::NoStyle));
+
+ // For now, just attach these as notes.
+ self.highlighted_note(msg);
+ self
+ }
+
+ pub fn note_trait_signature(&mut self, name: Symbol, signature: String) -> &mut Self {
+ self.highlighted_note(vec![
+ (format!("`{}` from trait: `", name), Style::NoStyle),
+ (signature, Style::Highlight),
+ ("`".to_string(), Style::NoStyle),
+ ]);
+ self
+ }
+
+ /// 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(), None);
+ self
+ }
+
+ pub fn highlighted_note<M: Into<SubdiagnosticMessage>>(
+ &mut self,
+ msg: Vec<(M, Style)>,
+ ) -> &mut Self {
+ self.sub_with_highlights(Level::Note, msg, MultiSpan::new(), None);
+ self
+ }
+
+ /// Prints the span with a note above it.
+ /// This is like [`Diagnostic::note()`], but it gets its own span.
+ pub fn note_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self {
+ self.sub(Level::OnceNote, msg, MultiSpan::new(), None);
+ self
+ }
+
+ /// Prints the span with a note above it.
+ /// This is like [`Diagnostic::note()`], but it gets its own span.
+ #[rustc_lint_diagnostics]
+ pub fn span_note<S: Into<MultiSpan>>(
+ &mut self,
+ sp: S,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self {
+ self.sub(Level::Note, msg, sp.into(), None);
+ self
+ }
+
+ /// Prints the span with a note above it.
+ /// This is like [`Diagnostic::note()`], but it gets its own span.
+ pub fn span_note_once<S: Into<MultiSpan>>(
+ &mut self,
+ sp: S,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self {
+ self.sub(Level::OnceNote, msg, sp.into(), None);
+ self
+ }
+
+ /// 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(None), msg, MultiSpan::new(), None);
+ self
+ }
+
+ /// Prints the span with a warning above it.
+ /// This is like [`Diagnostic::warn()`], but it gets its own span.
+ #[rustc_lint_diagnostics]
+ pub fn span_warn<S: Into<MultiSpan>>(
+ &mut self,
+ sp: S,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self {
+ self.sub(Level::Warning(None), msg, sp.into(), None);
+ self
+ }
+
+ /// 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(), None);
+ self
+ }
+
+ /// Add a help message attached to this diagnostic with a customizable highlighted message.
+ pub fn highlighted_help(&mut self, msg: Vec<(String, Style)>) -> &mut Self {
+ self.sub_with_highlights(Level::Help, msg, MultiSpan::new(), None);
+ self
+ }
+
+ /// Prints the span with some help above it.
+ /// This is like [`Diagnostic::help()`], but it gets its own span.
+ #[rustc_lint_diagnostics]
+ pub fn span_help<S: Into<MultiSpan>>(
+ &mut self,
+ sp: S,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self {
+ self.sub(Level::Help, msg, sp.into(), None);
+ self
+ }
+
+ /// Help the user upgrade to the latest edition.
+ /// This is factored out to make sure it does the right thing with `Cargo.toml`.
+ pub fn help_use_latest_edition(&mut self) -> &mut Self {
+ if std::env::var_os("CARGO").is_some() {
+ self.help(&format!("set `edition = \"{}\"` in `Cargo.toml`", LATEST_STABLE_EDITION));
+ } else {
+ self.help(&format!("pass `--edition {}` to `rustc`", LATEST_STABLE_EDITION));
+ }
+ self.note("for more on editions, read https://doc.rust-lang.org/edition-guide");
+ self
+ }
+
+ /// Disallow attaching suggestions this diagnostic.
+ /// Any suggestions attached e.g. with the `span_suggestion_*` methods
+ /// (before and after the call to `disable_suggestions`) will be ignored.
+ pub fn disable_suggestions(&mut self) -> &mut Self {
+ self.suggestions = Err(SuggestionsDisabled);
+ self
+ }
+
+ /// Clear any existing suggestions.
+ pub fn clear_suggestions(&mut self) -> &mut Self {
+ if let Ok(suggestions) = &mut self.suggestions {
+ suggestions.clear();
+ }
+ self
+ }
+
+ /// Helper for pushing to `self.suggestions`, if available (not disable).
+ fn push_suggestion(&mut self, suggestion: CodeSuggestion) {
+ if let Ok(suggestions) = &mut self.suggestions {
+ suggestions.push(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(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.multipart_suggestion_with_style(
+ msg,
+ suggestion,
+ 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.
+ pub fn multipart_suggestion_verbose(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.multipart_suggestion_with_style(
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::ShowAlways,
+ )
+ }
+ /// [`Diagnostic::multipart_suggestion()`] but you can set the [`SuggestionStyle`].
+ pub fn multipart_suggestion_with_style(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ style: SuggestionStyle,
+ ) -> &mut Self {
+ assert!(!suggestion.is_empty());
+ self.push_suggestion(CodeSuggestion {
+ substitutions: vec![Substitution {
+ parts: suggestion
+ .into_iter()
+ .map(|(span, snippet)| SubstitutionPart { snippet, span })
+ .collect(),
+ }],
+ msg: self.subdiagnostic_message_to_diagnostic_message(msg),
+ style,
+ applicability,
+ });
+ self
+ }
+
+ /// Prints out a message with for a multipart suggestion without showing the suggested code.
+ ///
+ /// This is intended to be used for suggestions that are obvious in what the changes need to
+ /// be from the message, showing the span label inline would be visually unpleasant
+ /// (marginally overlapping spans or multiline spans) and showing the snippet window wouldn't
+ /// improve understandability.
+ pub fn tool_only_multipart_suggestion(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self {
+ assert!(!suggestion.is_empty());
+ self.push_suggestion(CodeSuggestion {
+ substitutions: vec![Substitution {
+ parts: suggestion
+ .into_iter()
+ .map(|(span, snippet)| SubstitutionPart { snippet, span })
+ .collect(),
+ }],
+ msg: self.subdiagnostic_message_to_diagnostic_message(msg),
+ style: SuggestionStyle::CompletelyHidden,
+ applicability,
+ });
+ self
+ }
+
+ /// 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:
+ ///
+ /// ```text
+ /// try adding parentheses: `(tup.0).1`
+ /// ```
+ ///
+ /// The message
+ ///
+ /// * should not end in any punctuation (a `:` is added automatically)
+ /// * should not be a question (avoid language like "did you mean")
+ /// * should not contain any phrases like "the following", "as shown", etc.
+ /// * may look like "to do xyz, use" or "to do xyz, use abc"
+ /// * may contain a name of a function, variable, or type, but not whole expressions
+ ///
+ /// See `CodeSuggestion` for more information.
+ pub fn span_suggestion(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.span_suggestion_with_style(
+ sp,
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::ShowCode,
+ );
+ self
+ }
+
+ /// [`Diagnostic::span_suggestion()`] but you can set the [`SuggestionStyle`].
+ pub fn span_suggestion_with_style(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ style: SuggestionStyle,
+ ) -> &mut Self {
+ self.push_suggestion(CodeSuggestion {
+ substitutions: vec![Substitution {
+ parts: vec![SubstitutionPart { snippet: suggestion.to_string(), span: sp }],
+ }],
+ msg: self.subdiagnostic_message_to_diagnostic_message(msg),
+ style,
+ applicability,
+ });
+ self
+ }
+
+ /// Always show the suggested change.
+ pub fn span_suggestion_verbose(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.span_suggestion_with_style(
+ sp,
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::ShowAlways,
+ );
+ self
+ }
+
+ /// Prints out a message with multiple suggested edits of the code.
+ /// See also [`Diagnostic::span_suggestion()`].
+ pub fn span_suggestions(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestions: impl Iterator<Item = String>,
+ applicability: Applicability,
+ ) -> &mut Self {
+ let mut suggestions: Vec<_> = suggestions.collect();
+ suggestions.sort();
+ let substitutions = suggestions
+ .into_iter()
+ .map(|snippet| Substitution { parts: vec![SubstitutionPart { snippet, span: sp }] })
+ .collect();
+ self.push_suggestion(CodeSuggestion {
+ substitutions,
+ msg: self.subdiagnostic_message_to_diagnostic_message(msg),
+ style: SuggestionStyle::ShowCode,
+ applicability,
+ });
+ self
+ }
+
+ /// Prints out a message with multiple suggested edits of the code.
+ /// See also [`Diagnostic::span_suggestion()`].
+ pub fn multipart_suggestions(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestions: impl Iterator<Item = Vec<(Span, String)>>,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.push_suggestion(CodeSuggestion {
+ substitutions: suggestions
+ .map(|sugg| Substitution {
+ parts: sugg
+ .into_iter()
+ .map(|(span, snippet)| SubstitutionPart { snippet, span })
+ .collect(),
+ })
+ .collect(),
+ msg: self.subdiagnostic_message_to_diagnostic_message(msg),
+ style: SuggestionStyle::ShowCode,
+ applicability,
+ });
+ self
+ }
+ /// 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.
+ ///
+ /// See `CodeSuggestion` for more information.
+ pub fn span_suggestion_short(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.span_suggestion_with_style(
+ sp,
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::HideCodeInline,
+ );
+ self
+ }
+
+ /// Prints out a message for a suggestion without showing the suggested code.
+ ///
+ /// This is intended to be used for suggestions that are obvious in what the changes need to
+ /// be from the message, showing the span label inline would be visually unpleasant
+ /// (marginally overlapping spans or multiline spans) and showing the snippet window wouldn't
+ /// improve understandability.
+ pub fn span_suggestion_hidden(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.span_suggestion_with_style(
+ sp,
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::HideCodeAlways,
+ );
+ self
+ }
+
+ /// 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
+ /// need to be from the message, but we still want other tools to be able to apply them.
+ pub fn tool_only_span_suggestion(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self {
+ self.span_suggestion_with_style(
+ sp,
+ msg,
+ suggestion,
+ applicability,
+ SuggestionStyle::CompletelyHidden,
+ );
+ self
+ }
+
+ /// Add a subdiagnostic from a type that implements `SessionSubdiagnostic` - see
+ /// [rustc_macros::SessionSubdiagnostic].
+ pub fn subdiagnostic(&mut self, subdiagnostic: impl AddSubdiagnostic) -> &mut Self {
+ subdiagnostic.add_to_diagnostic(self);
+ self
+ }
+
+ pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self {
+ self.span = sp.into();
+ if let Some(span) = self.span.primary_span() {
+ self.sort_span = span;
+ }
+ self
+ }
+
+ pub fn set_is_lint(&mut self) -> &mut Self {
+ self.is_lint = true;
+ self
+ }
+
+ pub fn code(&mut self, s: DiagnosticId) -> &mut Self {
+ self.code = Some(s);
+ self
+ }
+
+ pub fn clear_code(&mut self) -> &mut Self {
+ self.code = None;
+ self
+ }
+
+ pub fn get_code(&self) -> Option<DiagnosticId> {
+ self.code.clone()
+ }
+
+ pub fn set_primary_message(&mut self, msg: impl Into<DiagnosticMessage>) -> &mut Self {
+ self.message[0] = (msg.into(), Style::NoStyle);
+ self
+ }
+
+ pub fn args(&self) -> &[DiagnosticArg<'static>] {
+ &self.args
+ }
+
+ pub fn set_arg(
+ &mut self,
+ name: impl Into<Cow<'static, str>>,
+ arg: impl IntoDiagnosticArg,
+ ) -> &mut Self {
+ self.args.push((name.into(), arg.into_diagnostic_arg()));
+ self
+ }
+
+ pub fn styled_message(&self) -> &[(DiagnosticMessage, Style)] {
+ &self.message
+ }
+
+ /// 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
+ /// passes the user's string along).
+ fn subdiagnostic_message_to_diagnostic_message(
+ &self,
+ attr: impl Into<SubdiagnosticMessage>,
+ ) -> DiagnosticMessage {
+ let msg =
+ self.message.iter().map(|(msg, _)| msg).next().expect("diagnostic with no messages");
+ msg.with_subdiagnostic_message(attr.into())
+ }
+
+ /// Convenience function for internal use, clients should use one of the
+ /// public methods above.
+ ///
+ /// Used by `proc_macro_server` for implementing `server::Diagnostic`.
+ pub fn sub(
+ &mut self,
+ level: Level,
+ message: impl Into<SubdiagnosticMessage>,
+ span: MultiSpan,
+ render_span: Option<MultiSpan>,
+ ) {
+ let sub = SubDiagnostic {
+ level,
+ message: vec![(
+ self.subdiagnostic_message_to_diagnostic_message(message),
+ Style::NoStyle,
+ )],
+ span,
+ render_span,
+ };
+ self.children.push(sub);
+ }
+
+ /// Convenience function for internal use, clients should use one of the
+ /// public methods above.
+ fn sub_with_highlights<M: Into<SubdiagnosticMessage>>(
+ &mut self,
+ level: Level,
+ mut message: Vec<(M, Style)>,
+ span: MultiSpan,
+ render_span: Option<MultiSpan>,
+ ) {
+ let message = message
+ .drain(..)
+ .map(|m| (self.subdiagnostic_message_to_diagnostic_message(m.0), m.1))
+ .collect();
+ let sub = SubDiagnostic { level, message, span, render_span };
+ self.children.push(sub);
+ }
+
+ /// Fields used for Hash, and PartialEq trait
+ fn keys(
+ &self,
+ ) -> (
+ &Level,
+ &[(DiagnosticMessage, Style)],
+ &Option<DiagnosticId>,
+ &MultiSpan,
+ &Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
+ Option<&[SubDiagnostic]>,
+ ) {
+ (
+ &self.level,
+ &self.message,
+ &self.code,
+ &self.span,
+ &self.suggestions,
+ (if self.is_lint { None } else { Some(&self.children) }),
+ )
+ }
+}
+
+impl Hash for Diagnostic {
+ fn hash<H>(&self, state: &mut H)
+ where
+ H: Hasher,
+ {
+ self.keys().hash(state);
+ }
+}
+
+impl PartialEq for Diagnostic {
+ fn eq(&self, other: &Self) -> bool {
+ self.keys() == other.keys()
+ }
+}
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
new file mode 100644
index 000000000..9e68ee282
--- /dev/null
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -0,0 +1,616 @@
+use crate::diagnostic::IntoDiagnosticArg;
+use crate::{
+ Diagnostic, DiagnosticId, DiagnosticMessage, DiagnosticStyledString, ErrorGuaranteed,
+ SubdiagnosticMessage,
+};
+use crate::{Handler, Level, MultiSpan, StashKey};
+use rustc_lint_defs::Applicability;
+
+use rustc_span::Span;
+use std::borrow::Cow;
+use std::fmt::{self, Debug};
+use std::marker::PhantomData;
+use std::ops::{Deref, DerefMut};
+use std::thread::panicking;
+use tracing::debug;
+
+/// Used for emitting structured error messages and other diagnostic information.
+///
+/// If there is some state in a downstream crate you would like to
+/// access in the methods of `DiagnosticBuilder` here, consider
+/// extending `HandlerFlags`, accessed via `self.handler.flags`.
+#[must_use]
+#[derive(Clone)]
+pub struct DiagnosticBuilder<'a, G: EmissionGuarantee> {
+ inner: DiagnosticBuilderInner<'a>,
+ _marker: PhantomData<G>,
+}
+
+/// This type exists only for `DiagnosticBuilder::forget_guarantee`, because it:
+/// 1. lacks the `G` parameter and therefore `DiagnosticBuilder<G1>` can be
+/// converted into `DiagnosticBuilder<G2>` while reusing the `inner` field
+/// 2. can implement the `Drop` "bomb" instead of `DiagnosticBuilder`, as it
+/// contains all of the data (`state` + `diagnostic`) of `DiagnosticBuilder`
+///
+/// The `diagnostic` field is not `Copy` and can't be moved out of whichever
+/// type implements the `Drop` "bomb", but because of the above two facts, that
+/// never needs to happen - instead, the whole `inner: DiagnosticBuilderInner`
+/// can be moved out of a `DiagnosticBuilder` and into another.
+#[must_use]
+#[derive(Clone)]
+struct DiagnosticBuilderInner<'a> {
+ state: DiagnosticBuilderState<'a>,
+
+ /// `Diagnostic` is a large type, and `DiagnosticBuilder` is often used as a
+ /// return value, especially within the frequently-used `PResult` type.
+ /// In theory, return value optimization (RVO) should avoid unnecessary
+ /// copying. In practice, it does not (at the time of writing).
+ diagnostic: Box<Diagnostic>,
+}
+
+#[derive(Clone)]
+enum DiagnosticBuilderState<'a> {
+ /// Initial state of a `DiagnosticBuilder`, before `.emit()` or `.cancel()`.
+ ///
+ /// The `Diagnostic` will be emitted through this `Handler`.
+ Emittable(&'a Handler),
+
+ /// State of a `DiagnosticBuilder`, after `.emit()` or *during* `.cancel()`.
+ ///
+ /// The `Diagnostic` will be ignored when calling `.emit()`, and it can be
+ /// assumed that `.emit()` was previously called, to end up in this state.
+ ///
+ /// While this is also used by `.cancel()`, this state is only observed by
+ /// the `Drop` `impl` of `DiagnosticBuilderInner`, as `.cancel()` takes
+ /// `self` by-value specifically to prevent any attempts to `.emit()`.
+ ///
+ // FIXME(eddyb) currently this doesn't prevent extending the `Diagnostic`,
+ // despite that being potentially lossy, if important information is added
+ // *after* the original `.emit()` call.
+ AlreadyEmittedOrDuringCancellation,
+}
+
+// `DiagnosticBuilderState` should be pointer-sized.
+rustc_data_structures::static_assert_size!(
+ DiagnosticBuilderState<'_>,
+ std::mem::size_of::<&Handler>()
+);
+
+/// Trait for types that `DiagnosticBuilder::emit` can return as a "guarantee"
+/// (or "proof") token that the emission happened.
+pub trait EmissionGuarantee: Sized {
+ /// Implementation of `DiagnosticBuilder::emit`, fully controlled by each
+ /// `impl` of `EmissionGuarantee`, to make it impossible to create a value
+ /// of `Self` without actually performing the emission.
+ #[track_caller]
+ fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self;
+}
+
+/// Private module for sealing the `IsError` helper trait.
+mod sealed_level_is_error {
+ use crate::Level;
+
+ /// Sealed helper trait for statically checking that a `Level` is an error.
+ pub(crate) trait IsError<const L: Level> {}
+
+ impl IsError<{ Level::Bug }> for () {}
+ impl IsError<{ Level::DelayedBug }> for () {}
+ impl IsError<{ Level::Fatal }> for () {}
+ // NOTE(eddyb) `Level::Error { lint: true }` is also an error, but lints
+ // don't need error guarantees, as their levels are always dynamic.
+ impl IsError<{ Level::Error { lint: false } }> for () {}
+}
+
+impl<'a> DiagnosticBuilder<'a, ErrorGuaranteed> {
+ /// Convenience function for internal use, clients should use one of the
+ /// `struct_*` methods on [`Handler`].
+ pub(crate) fn new_guaranteeing_error<M: Into<DiagnosticMessage>, const L: Level>(
+ handler: &'a Handler,
+ message: M,
+ ) -> Self
+ where
+ (): sealed_level_is_error::IsError<L>,
+ {
+ Self {
+ inner: DiagnosticBuilderInner {
+ state: DiagnosticBuilderState::Emittable(handler),
+ diagnostic: Box::new(Diagnostic::new_with_code(L, None, message)),
+ },
+ _marker: PhantomData,
+ }
+ }
+
+ /// Discard the guarantee `.emit()` would return, in favor of having the
+ /// type `DiagnosticBuilder<'a, ()>`. This may be necessary whenever there
+ /// is a common codepath handling both errors and warnings.
+ pub fn forget_guarantee(self) -> DiagnosticBuilder<'a, ()> {
+ DiagnosticBuilder { inner: self.inner, _marker: PhantomData }
+ }
+}
+
+// FIXME(eddyb) make `ErrorGuaranteed` impossible to create outside `.emit()`.
+impl EmissionGuarantee for ErrorGuaranteed {
+ fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self {
+ match db.inner.state {
+ // First `.emit()` call, the `&Handler` is still available.
+ DiagnosticBuilderState::Emittable(handler) => {
+ db.inner.state = DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation;
+
+ let guar = handler.emit_diagnostic(&mut db.inner.diagnostic);
+
+ // Only allow a guarantee if the `level` wasn't switched to a
+ // non-error - the field isn't `pub`, but the whole `Diagnostic`
+ // can be overwritten with a new one, thanks to `DerefMut`.
+ assert!(
+ db.inner.diagnostic.is_error(),
+ "emitted non-error ({:?}) diagnostic \
+ from `DiagnosticBuilder<ErrorGuaranteed>`",
+ db.inner.diagnostic.level,
+ );
+ guar.unwrap()
+ }
+ // `.emit()` was previously called, disallowed from repeating it,
+ // but can take advantage of the previous `.emit()`'s guarantee
+ // still being applicable (i.e. as a form of idempotency).
+ DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {
+ // Only allow a guarantee if the `level` wasn't switched to a
+ // non-error - the field isn't `pub`, but the whole `Diagnostic`
+ // can be overwritten with a new one, thanks to `DerefMut`.
+ assert!(
+ db.inner.diagnostic.is_error(),
+ "`DiagnosticBuilder<ErrorGuaranteed>`'s diagnostic \
+ became non-error ({:?}), after original `.emit()`",
+ db.inner.diagnostic.level,
+ );
+ ErrorGuaranteed::unchecked_claim_error_was_emitted()
+ }
+ }
+ }
+}
+
+impl<'a> DiagnosticBuilder<'a, ()> {
+ /// Convenience function for internal use, clients should use one of the
+ /// `struct_*` methods on [`Handler`].
+ pub(crate) fn new<M: Into<DiagnosticMessage>>(
+ handler: &'a Handler,
+ level: Level,
+ message: M,
+ ) -> Self {
+ let diagnostic = Diagnostic::new_with_code(level, None, message);
+ Self::new_diagnostic(handler, diagnostic)
+ }
+
+ /// Creates a new `DiagnosticBuilder` with an already constructed
+ /// diagnostic.
+ pub(crate) fn new_diagnostic(handler: &'a Handler, diagnostic: Diagnostic) -> Self {
+ debug!("Created new diagnostic");
+ Self {
+ inner: DiagnosticBuilderInner {
+ state: DiagnosticBuilderState::Emittable(handler),
+ diagnostic: Box::new(diagnostic),
+ },
+ _marker: PhantomData,
+ }
+ }
+}
+
+// FIXME(eddyb) should there be a `Option<ErrorGuaranteed>` impl as well?
+impl EmissionGuarantee for () {
+ fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self {
+ match db.inner.state {
+ // First `.emit()` call, the `&Handler` is still available.
+ DiagnosticBuilderState::Emittable(handler) => {
+ db.inner.state = DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation;
+
+ handler.emit_diagnostic(&mut db.inner.diagnostic);
+ }
+ // `.emit()` was previously called, disallowed from repeating it.
+ DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
+ }
+ }
+}
+
+impl<'a> DiagnosticBuilder<'a, !> {
+ /// Convenience function for internal use, clients should use one of the
+ /// `struct_*` methods on [`Handler`].
+ pub(crate) fn new_fatal(handler: &'a Handler, message: impl Into<DiagnosticMessage>) -> Self {
+ let diagnostic = Diagnostic::new_with_code(Level::Fatal, None, message);
+ Self::new_diagnostic_fatal(handler, diagnostic)
+ }
+
+ /// Creates a new `DiagnosticBuilder` with an already constructed
+ /// diagnostic.
+ pub(crate) fn new_diagnostic_fatal(handler: &'a Handler, diagnostic: Diagnostic) -> Self {
+ debug!("Created new diagnostic");
+ Self {
+ inner: DiagnosticBuilderInner {
+ state: DiagnosticBuilderState::Emittable(handler),
+ diagnostic: Box::new(diagnostic),
+ },
+ _marker: PhantomData,
+ }
+ }
+}
+
+impl EmissionGuarantee for ! {
+ fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self {
+ match db.inner.state {
+ // First `.emit()` call, the `&Handler` is still available.
+ DiagnosticBuilderState::Emittable(handler) => {
+ db.inner.state = DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation;
+
+ handler.emit_diagnostic(&mut db.inner.diagnostic);
+ }
+ // `.emit()` was previously called, disallowed from repeating it.
+ DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
+ }
+ // Then fatally error, returning `!`
+ crate::FatalError.raise()
+ }
+}
+
+/// In general, the `DiagnosticBuilder` uses deref to allow access to
+/// the fields and methods of the embedded `diagnostic` in a
+/// transparent way. *However,* many of the methods are intended to
+/// be used in a chained way, and hence ought to return `self`. In
+/// that case, we can't just naively forward to the method on the
+/// `diagnostic`, because the return type would be a `&Diagnostic`
+/// instead of a `&DiagnosticBuilder<'a>`. This `forward!` macro makes
+/// it easy to declare such methods on the builder.
+macro_rules! forward {
+ // Forward pattern for &mut self -> &mut Self
+ (
+ $(#[$attrs:meta])*
+ pub fn $n:ident(&mut self, $($name:ident: $ty:ty),* $(,)?) -> &mut Self
+ ) => {
+ $(#[$attrs])*
+ #[doc = concat!("See [`Diagnostic::", stringify!($n), "()`].")]
+ pub fn $n(&mut self, $($name: $ty),*) -> &mut Self {
+ self.inner.diagnostic.$n($($name),*);
+ self
+ }
+ };
+}
+
+impl<G: EmissionGuarantee> Deref for DiagnosticBuilder<'_, G> {
+ type Target = Diagnostic;
+
+ fn deref(&self) -> &Diagnostic {
+ &self.inner.diagnostic
+ }
+}
+
+impl<G: EmissionGuarantee> DerefMut for DiagnosticBuilder<'_, G> {
+ fn deref_mut(&mut self) -> &mut Diagnostic {
+ &mut self.inner.diagnostic
+ }
+}
+
+impl<'a, G: EmissionGuarantee> DiagnosticBuilder<'a, G> {
+ /// Emit the diagnostic.
+ #[track_caller]
+ pub fn emit(&mut self) -> G {
+ G::diagnostic_builder_emit_producing_guarantee(self)
+ }
+
+ /// Emit the diagnostic unless `delay` is true,
+ /// in which case the emission will be delayed as a bug.
+ ///
+ /// See `emit` and `delay_as_bug` for details.
+ #[track_caller]
+ pub fn emit_unless(&mut self, delay: bool) -> G {
+ if delay {
+ self.downgrade_to_delayed_bug();
+ }
+ self.emit()
+ }
+
+ /// Cancel the diagnostic (a structured diagnostic must either be emitted or
+ /// cancelled or it will panic when dropped).
+ ///
+ /// This method takes `self` by-value to disallow calling `.emit()` on it,
+ /// which may be expected to *guarantee* the emission of an error, either
+ /// at the time of the call, or through a prior `.emit()` call.
+ pub fn cancel(mut self) {
+ self.inner.state = DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation;
+ drop(self);
+ }
+
+ /// Stashes diagnostic for possible later improvement in a different,
+ /// later stage of the compiler. The diagnostic can be accessed with
+ /// the provided `span` and `key` through [`Handler::steal_diagnostic()`].
+ ///
+ /// As with `buffer`, this is unless the handler has disabled such buffering.
+ pub fn stash(self, span: Span, key: StashKey) {
+ if let Some((diag, handler)) = self.into_diagnostic() {
+ handler.stash_diagnostic(span, key, diag);
+ }
+ }
+
+ /// Converts the builder to a `Diagnostic` for later emission,
+ /// unless handler has disabled such buffering, or `.emit()` was called.
+ pub fn into_diagnostic(mut self) -> Option<(Diagnostic, &'a Handler)> {
+ let handler = match self.inner.state {
+ // No `.emit()` calls, the `&Handler` is still available.
+ DiagnosticBuilderState::Emittable(handler) => handler,
+ // `.emit()` was previously called, nothing we can do.
+ DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {
+ return None;
+ }
+ };
+
+ if handler.flags.dont_buffer_diagnostics || handler.flags.treat_err_as_bug.is_some() {
+ self.emit();
+ return None;
+ }
+
+ // Take the `Diagnostic` by replacing it with a dummy.
+ let dummy = Diagnostic::new(Level::Allow, DiagnosticMessage::Str("".to_string()));
+ let diagnostic = std::mem::replace(&mut *self.inner.diagnostic, dummy);
+
+ // Disable the ICE on `Drop`.
+ self.cancel();
+
+ // Logging here is useful to help track down where in logs an error was
+ // actually emitted.
+ debug!("buffer: diagnostic={:?}", diagnostic);
+
+ Some((diagnostic, handler))
+ }
+
+ /// Buffers the diagnostic for later emission,
+ /// unless handler has disabled such buffering.
+ pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>) {
+ buffered_diagnostics.extend(self.into_diagnostic().map(|(diag, _)| diag));
+ }
+
+ /// Delay emission of this diagnostic as a bug.
+ ///
+ /// This can be useful in contexts where an error indicates a bug but
+ /// typically this only happens when other compilation errors have already
+ /// happened. In those cases this can be used to defer emission of this
+ /// diagnostic as a bug in the compiler only if no other errors have been
+ /// emitted.
+ ///
+ /// In the meantime, though, callsites are required to deal with the "bug"
+ /// locally in whichever way makes the most sense.
+ #[track_caller]
+ pub fn delay_as_bug(&mut self) {
+ self.downgrade_to_delayed_bug();
+ self.emit();
+ }
+
+ forward!(
+ #[track_caller]
+ pub fn downgrade_to_delayed_bug(&mut self,) -> &mut Self
+ );
+
+ forward!(
+ /// Appends a labeled span to the diagnostic.
+ ///
+ /// Labels are used to convey additional context for the diagnostic's primary span. They will
+ /// be shown together with the original diagnostic's span, *not* with spans added by
+ /// `span_note`, `span_help`, etc. Therefore, if the primary span is not displayable (because
+ /// the span is `DUMMY_SP` or the source code isn't found), labels will not be displayed
+ /// either.
+ ///
+ /// Implementation-wise, the label span is pushed onto the [`MultiSpan`] that was created when
+ /// the diagnostic was constructed. However, the label span is *not* considered a
+ /// ["primary span"][`MultiSpan`]; only the `Span` supplied when creating the diagnostic is
+ /// primary.
+ pub fn span_label(&mut self, span: Span, label: impl Into<SubdiagnosticMessage>) -> &mut Self);
+
+ forward!(
+ /// Labels all the given spans with the provided label.
+ /// See [`Diagnostic::span_label()`] for more information.
+ pub fn span_labels(
+ &mut self,
+ spans: impl IntoIterator<Item = Span>,
+ label: impl AsRef<str>,
+ ) -> &mut Self);
+
+ forward!(pub fn note_expected_found(
+ &mut self,
+ expected_label: &dyn fmt::Display,
+ expected: DiagnosticStyledString,
+ found_label: &dyn fmt::Display,
+ found: DiagnosticStyledString,
+ ) -> &mut Self);
+
+ forward!(pub fn note_expected_found_extra(
+ &mut self,
+ expected_label: &dyn fmt::Display,
+ expected: DiagnosticStyledString,
+ found_label: &dyn fmt::Display,
+ found: DiagnosticStyledString,
+ expected_extra: &dyn fmt::Display,
+ found_extra: &dyn fmt::Display,
+ ) -> &mut Self);
+
+ forward!(pub fn note_unsuccessful_coercion(
+ &mut self,
+ expected: DiagnosticStyledString,
+ found: DiagnosticStyledString,
+ ) -> &mut Self);
+
+ forward!(pub fn note(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
+ forward!(pub fn note_once(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
+ forward!(pub fn span_note(
+ &mut self,
+ sp: impl Into<MultiSpan>,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self);
+ forward!(pub fn span_note_once(
+ &mut self,
+ sp: impl Into<MultiSpan>,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self);
+ forward!(pub fn warn(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
+ forward!(pub fn span_warn(
+ &mut self,
+ sp: impl Into<MultiSpan>,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self);
+ forward!(pub fn help(&mut self, msg: impl Into<SubdiagnosticMessage>) -> &mut Self);
+ forward!(pub fn span_help(
+ &mut self,
+ sp: impl Into<MultiSpan>,
+ msg: impl Into<SubdiagnosticMessage>,
+ ) -> &mut Self);
+ forward!(pub fn help_use_latest_edition(&mut self,) -> &mut Self);
+ forward!(pub fn set_is_lint(&mut self,) -> &mut Self);
+
+ forward!(pub fn disable_suggestions(&mut self,) -> &mut Self);
+ forward!(pub fn clear_suggestions(&mut self,) -> &mut Self);
+
+ forward!(pub fn multipart_suggestion(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn multipart_suggestion_verbose(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn tool_only_multipart_suggestion(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: Vec<(Span, String)>,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn span_suggestion(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn span_suggestions(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestions: impl Iterator<Item = String>,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn multipart_suggestions(
+ &mut self,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestions: impl Iterator<Item = Vec<(Span, String)>>,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn span_suggestion_short(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn span_suggestion_verbose(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn span_suggestion_hidden(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self);
+ forward!(pub fn tool_only_span_suggestion(
+ &mut self,
+ sp: Span,
+ msg: impl Into<SubdiagnosticMessage>,
+ suggestion: impl ToString,
+ applicability: Applicability,
+ ) -> &mut Self);
+
+ forward!(pub fn set_primary_message(&mut self, msg: impl Into<DiagnosticMessage>) -> &mut Self);
+ forward!(pub fn set_span(&mut self, sp: impl Into<MultiSpan>) -> &mut Self);
+ forward!(pub fn code(&mut self, s: DiagnosticId) -> &mut Self);
+ forward!(pub fn set_arg(
+ &mut self,
+ name: impl Into<Cow<'static, str>>,
+ arg: impl IntoDiagnosticArg,
+ ) -> &mut Self);
+
+ forward!(pub fn subdiagnostic(
+ &mut self,
+ subdiagnostic: impl crate::AddSubdiagnostic
+ ) -> &mut Self);
+}
+
+impl<G: EmissionGuarantee> Debug for DiagnosticBuilder<'_, G> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.inner.diagnostic.fmt(f)
+ }
+}
+
+/// Destructor bomb - a `DiagnosticBuilder` must be either emitted or cancelled
+/// or we emit a bug.
+impl Drop for DiagnosticBuilderInner<'_> {
+ fn drop(&mut self) {
+ match self.state {
+ // No `.emit()` or `.cancel()` calls.
+ DiagnosticBuilderState::Emittable(handler) => {
+ if !panicking() {
+ handler.emit_diagnostic(&mut Diagnostic::new(
+ Level::Bug,
+ DiagnosticMessage::Str(
+ "the following error was constructed but not emitted".to_string(),
+ ),
+ ));
+ handler.emit_diagnostic(&mut self.diagnostic);
+ panic!();
+ }
+ }
+ // `.emit()` was previously called, or maybe we're during `.cancel()`.
+ DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
+ }
+ }
+}
+
+#[macro_export]
+macro_rules! struct_span_err {
+ ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
+ $session.struct_span_err_with_code(
+ $span,
+ &format!($($message)*),
+ $crate::error_code!($code),
+ )
+ })
+}
+
+#[macro_export]
+macro_rules! error_code {
+ ($code:ident) => {{ $crate::DiagnosticId::Error(stringify!($code).to_owned()) }};
+}
+
+/// Wrapper around a `DiagnosticBuilder` for creating lints.
+pub struct LintDiagnosticBuilder<'a, G: EmissionGuarantee>(DiagnosticBuilder<'a, G>);
+
+impl<'a, G: EmissionGuarantee> LintDiagnosticBuilder<'a, G> {
+ #[rustc_lint_diagnostics]
+ /// Return the inner `DiagnosticBuilder`, first setting the primary message to `msg`.
+ pub fn build(mut self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'a, G> {
+ self.0.set_primary_message(msg);
+ self.0.set_is_lint();
+ self.0
+ }
+
+ /// Create a `LintDiagnosticBuilder` from some existing `DiagnosticBuilder`.
+ pub fn new(err: DiagnosticBuilder<'a, G>) -> LintDiagnosticBuilder<'a, G> {
+ LintDiagnosticBuilder(err)
+ }
+}
+
+impl<'a> LintDiagnosticBuilder<'a, ErrorGuaranteed> {
+ pub fn forget_guarantee(self) -> LintDiagnosticBuilder<'a, ()> {
+ LintDiagnosticBuilder(self.0.forget_guarantee())
+ }
+}
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
new file mode 100644
index 000000000..61d953cd6
--- /dev/null
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -0,0 +1,2687 @@
+//! The current rustc diagnostics emitter.
+//!
+//! An `Emitter` takes care of generating the output from a `DiagnosticBuilder` struct.
+//!
+//! There are various `Emitter` implementations that generate different output formats such as
+//! JSON and human readable output.
+//!
+//! The output types are defined in `rustc_session::config::ErrorOutputType`.
+
+use Destination::*;
+
+use rustc_span::source_map::SourceMap;
+use rustc_span::{FileLines, SourceFile, Span};
+
+use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
+use crate::styled_buffer::StyledBuffer;
+use crate::{
+ CodeSuggestion, Diagnostic, DiagnosticArg, DiagnosticId, DiagnosticMessage, FluentBundle,
+ Handler, LazyFallbackBundle, Level, MultiSpan, SubDiagnostic, SubstitutionHighlight,
+ SuggestionStyle,
+};
+
+use rustc_lint_defs::pluralize;
+
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sync::Lrc;
+use rustc_error_messages::FluentArgs;
+use rustc_span::hygiene::{ExpnKind, MacroKind};
+use std::borrow::Cow;
+use std::cmp::{max, min, Reverse};
+use std::io;
+use std::io::prelude::*;
+use std::iter;
+use std::path::Path;
+use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
+use termcolor::{Buffer, Color, WriteColor};
+use tracing::*;
+
+/// Default column width, used in tests and when terminal dimensions cannot be determined.
+const DEFAULT_COLUMN_WIDTH: usize = 140;
+
+/// Describes the way the content of the `rendered` field of the json output is generated
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum HumanReadableErrorType {
+ Default(ColorConfig),
+ AnnotateSnippet(ColorConfig),
+ Short(ColorConfig),
+}
+
+impl HumanReadableErrorType {
+ /// Returns a (`short`, `color`) tuple
+ pub fn unzip(self) -> (bool, ColorConfig) {
+ match self {
+ HumanReadableErrorType::Default(cc) => (false, cc),
+ HumanReadableErrorType::Short(cc) => (true, cc),
+ HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
+ }
+ }
+ pub fn new_emitter(
+ self,
+ dst: Box<dyn Write + Send>,
+ source_map: Option<Lrc<SourceMap>>,
+ bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ teach: bool,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> EmitterWriter {
+ let (short, color_config) = self.unzip();
+ let color = color_config.suggests_using_colors();
+ EmitterWriter::new(
+ dst,
+ source_map,
+ bundle,
+ fallback_bundle,
+ short,
+ teach,
+ color,
+ diagnostic_width,
+ macro_backtrace,
+ )
+ }
+}
+
+#[derive(Clone, Copy, Debug)]
+struct Margin {
+ /// The available whitespace in the left that can be consumed when centering.
+ pub whitespace_left: usize,
+ /// The column of the beginning of left-most span.
+ pub span_left: usize,
+ /// The column of the end of right-most span.
+ pub span_right: usize,
+ /// The beginning of the line to be displayed.
+ pub computed_left: usize,
+ /// The end of the line to be displayed.
+ pub computed_right: usize,
+ /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default
+ /// and in tests.
+ pub column_width: usize,
+ /// The end column of a span label, including the span. Doesn't account for labels not in the
+ /// same line as the span.
+ pub label_right: usize,
+}
+
+impl Margin {
+ fn new(
+ whitespace_left: usize,
+ span_left: usize,
+ span_right: usize,
+ label_right: usize,
+ column_width: usize,
+ max_line_len: usize,
+ ) -> Self {
+ // The 6 is padding to give a bit of room for `...` when displaying:
+ // ```
+ // error: message
+ // --> file.rs:16:58
+ // |
+ // 16 | ... fn foo(self) -> Self::Bar {
+ // | ^^^^^^^^^
+ // ```
+
+ let mut m = Margin {
+ whitespace_left: whitespace_left.saturating_sub(6),
+ span_left: span_left.saturating_sub(6),
+ span_right: span_right + 6,
+ computed_left: 0,
+ computed_right: 0,
+ column_width,
+ label_right: label_right + 6,
+ };
+ m.compute(max_line_len);
+ m
+ }
+
+ fn was_cut_left(&self) -> bool {
+ self.computed_left > 0
+ }
+
+ fn was_cut_right(&self, line_len: usize) -> bool {
+ let right =
+ if self.computed_right == self.span_right || self.computed_right == self.label_right {
+ // Account for the "..." padding given above. Otherwise we end up with code lines that
+ // do fit but end in "..." as if they were trimmed.
+ self.computed_right - 6
+ } else {
+ self.computed_right
+ };
+ right < line_len && self.computed_left + self.column_width < line_len
+ }
+
+ fn compute(&mut self, max_line_len: usize) {
+ // When there's a lot of whitespace (>20), we want to trim it as it is useless.
+ self.computed_left = if self.whitespace_left > 20 {
+ self.whitespace_left - 16 // We want some padding.
+ } else {
+ 0
+ };
+ // We want to show as much as possible, max_line_len is the right-most boundary for the
+ // relevant code.
+ self.computed_right = max(max_line_len, self.computed_left);
+
+ if self.computed_right - self.computed_left > self.column_width {
+ // Trimming only whitespace isn't enough, let's get craftier.
+ if self.label_right - self.whitespace_left <= self.column_width {
+ // Attempt to fit the code window only trimming whitespace.
+ self.computed_left = self.whitespace_left;
+ self.computed_right = self.computed_left + self.column_width;
+ } else if self.label_right - self.span_left <= self.column_width {
+ // Attempt to fit the code window considering only the spans and labels.
+ let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
+ self.computed_left = self.span_left.saturating_sub(padding_left);
+ self.computed_right = self.computed_left + self.column_width;
+ } else if self.span_right - self.span_left <= self.column_width {
+ // Attempt to fit the code window considering the spans and labels plus padding.
+ let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
+ self.computed_left = self.span_left.saturating_sub(padding_left);
+ self.computed_right = self.computed_left + self.column_width;
+ } else {
+ // Mostly give up but still don't show the full line.
+ self.computed_left = self.span_left;
+ self.computed_right = self.span_right;
+ }
+ }
+ }
+
+ fn left(&self, line_len: usize) -> usize {
+ min(self.computed_left, line_len)
+ }
+
+ fn right(&self, line_len: usize) -> usize {
+ if line_len.saturating_sub(self.computed_left) <= self.column_width {
+ line_len
+ } else {
+ min(line_len, self.computed_right)
+ }
+ }
+}
+
+const ANONYMIZED_LINE_NUM: &str = "LL";
+
+/// Emitter trait for emitting errors.
+pub trait Emitter {
+ /// Emit a structured diagnostic.
+ fn emit_diagnostic(&mut self, diag: &Diagnostic);
+
+ /// Emit a notification that an artifact has been output.
+ /// This is currently only supported for the JSON format,
+ /// other formats can, and will, simply ignore it.
+ fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
+
+ fn emit_future_breakage_report(&mut self, _diags: Vec<Diagnostic>) {}
+
+ /// Emit list of unused externs
+ fn emit_unused_externs(
+ &mut self,
+ _lint_level: rustc_lint_defs::Level,
+ _unused_externs: &[&str],
+ ) {
+ }
+
+ /// Checks if should show explanations about "rustc --explain"
+ fn should_show_explain(&self) -> bool {
+ true
+ }
+
+ /// Checks if we can use colors in the current output stream.
+ fn supports_color(&self) -> bool {
+ false
+ }
+
+ fn source_map(&self) -> Option<&Lrc<SourceMap>>;
+
+ /// Return `FluentBundle` with localized diagnostics for the locale requested by the user. If no
+ /// language was requested by the user then this will be `None` and `fallback_fluent_bundle`
+ /// should be used.
+ fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>>;
+
+ /// Return `FluentBundle` with localized diagnostics for the default locale of the compiler.
+ /// Used when the user has not requested a specific language or when a localized diagnostic is
+ /// unavailable for the requested locale.
+ fn fallback_fluent_bundle(&self) -> &FluentBundle;
+
+ /// Convert diagnostic arguments (a rustc internal type that exists to implement
+ /// `Encodable`/`Decodable`) into `FluentArgs` which is necessary to perform translation.
+ ///
+ /// Typically performed once for each diagnostic at the start of `emit_diagnostic` and then
+ /// passed around as a reference thereafter.
+ fn to_fluent_args<'arg>(&self, args: &[DiagnosticArg<'arg>]) -> FluentArgs<'arg> {
+ FromIterator::from_iter(args.to_vec().drain(..))
+ }
+
+ /// Convert `DiagnosticMessage`s to a string, performing translation if necessary.
+ fn translate_messages(
+ &self,
+ messages: &[(DiagnosticMessage, Style)],
+ args: &FluentArgs<'_>,
+ ) -> Cow<'_, str> {
+ Cow::Owned(
+ messages.iter().map(|(m, _)| self.translate_message(m, args)).collect::<String>(),
+ )
+ }
+
+ /// Convert a `DiagnosticMessage` to a string, performing translation if necessary.
+ fn translate_message<'a>(
+ &'a self,
+ message: &'a DiagnosticMessage,
+ args: &'a FluentArgs<'_>,
+ ) -> Cow<'_, str> {
+ trace!(?message, ?args);
+ let (identifier, attr) = match message {
+ DiagnosticMessage::Str(msg) => return Cow::Borrowed(&msg),
+ DiagnosticMessage::FluentIdentifier(identifier, attr) => (identifier, attr),
+ };
+
+ let bundle = match self.fluent_bundle() {
+ Some(bundle) if bundle.has_message(&identifier) => bundle,
+ _ => self.fallback_fluent_bundle(),
+ };
+
+ let message = bundle.get_message(&identifier).expect("missing diagnostic in fluent bundle");
+ let value = match attr {
+ Some(attr) => {
+ if let Some(attr) = message.get_attribute(attr) {
+ attr.value()
+ } else {
+ panic!("missing attribute `{attr}` in fluent message `{identifier}`")
+ }
+ }
+ None => {
+ if let Some(value) = message.value() {
+ value
+ } else {
+ panic!("missing value in fluent message `{identifier}`")
+ }
+ }
+ };
+
+ let mut err = vec![];
+ let translated = bundle.format_pattern(value, Some(&args), &mut err);
+ trace!(?translated, ?err);
+ debug_assert!(
+ err.is_empty(),
+ "identifier: {:?}, args: {:?}, errors: {:?}",
+ identifier,
+ args,
+ err
+ );
+ translated
+ }
+
+ /// Formats the substitutions of the primary_span
+ ///
+ /// There are a lot of conditions to this method, but in short:
+ ///
+ /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
+ /// we format the `help` suggestion depending on the content of the
+ /// substitutions. In that case, we return the modified span only.
+ ///
+ /// * If the current `Diagnostic` has multiple suggestions,
+ /// we return the original `primary_span` and the original suggestions.
+ fn primary_span_formatted<'a>(
+ &mut self,
+ diag: &'a Diagnostic,
+ fluent_args: &FluentArgs<'_>,
+ ) -> (MultiSpan, &'a [CodeSuggestion]) {
+ let mut primary_span = diag.span.clone();
+ let suggestions = diag.suggestions.as_ref().map_or(&[][..], |suggestions| &suggestions[..]);
+ if let Some((sugg, rest)) = suggestions.split_first() {
+ let msg = self.translate_message(&sugg.msg, fluent_args);
+ if rest.is_empty() &&
+ // ^ if there is only one suggestion
+ // don't display multi-suggestions as labels
+ sugg.substitutions.len() == 1 &&
+ // don't display multipart suggestions as labels
+ sugg.substitutions[0].parts.len() == 1 &&
+ // don't display long messages as labels
+ msg.split_whitespace().count() < 10 &&
+ // don't display multiline suggestions as labels
+ !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
+ ![
+ // when this style is set we want the suggestion to be a message, not inline
+ SuggestionStyle::HideCodeAlways,
+ // trivial suggestion for tooling's sake, never shown
+ SuggestionStyle::CompletelyHidden,
+ // subtle suggestion, never shown inline
+ SuggestionStyle::ShowAlways,
+ ].contains(&sugg.style)
+ {
+ let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
+ let msg = if substitution.is_empty() || sugg.style.hide_inline() {
+ // This substitution is only removal OR we explicitly don't want to show the
+ // code inline (`hide_inline`). Therefore, we don't show the substitution.
+ format!("help: {}", &msg)
+ } else {
+ // Show the default suggestion text with the substitution
+ format!(
+ "help: {}{}: `{}`",
+ &msg,
+ if self
+ .source_map()
+ .map(|sm| is_case_difference(
+ &**sm,
+ substitution,
+ sugg.substitutions[0].parts[0].span,
+ ))
+ .unwrap_or(false)
+ {
+ " (notice the capitalization)"
+ } else {
+ ""
+ },
+ substitution,
+ )
+ };
+ primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
+
+ // We return only the modified primary_span
+ (primary_span, &[])
+ } else {
+ // if there are multiple suggestions, print them all in full
+ // to be consistent. We could try to figure out if we can
+ // make one (or the first one) inline, but that would give
+ // undue importance to a semi-random suggestion
+ (primary_span, suggestions)
+ }
+ } else {
+ (primary_span, suggestions)
+ }
+ }
+
+ fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
+ &self,
+ source_map: &Option<Lrc<SourceMap>>,
+ span: &mut MultiSpan,
+ children: &mut Vec<SubDiagnostic>,
+ level: &Level,
+ backtrace: bool,
+ ) {
+ // Check for spans in macros, before `fix_multispans_in_extern_macros`
+ // has a chance to replace them.
+ let has_macro_spans: Vec<_> = iter::once(&*span)
+ .chain(children.iter().map(|child| &child.span))
+ .flat_map(|span| span.primary_spans())
+ .flat_map(|sp| sp.macro_backtrace())
+ .filter_map(|expn_data| {
+ match expn_data.kind {
+ ExpnKind::Root => None,
+
+ // Skip past non-macro entries, just in case there
+ // are some which do actually involve macros.
+ ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
+
+ ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)),
+ }
+ })
+ .collect();
+
+ if !backtrace {
+ self.fix_multispans_in_extern_macros(source_map, span, children);
+ }
+
+ self.render_multispans_macro_backtrace(span, children, backtrace);
+
+ if !backtrace {
+ if let Some((macro_kind, name)) = has_macro_spans.first() {
+ // Mark the actual macro this originates from
+ let and_then = if let Some((macro_kind, last_name)) = has_macro_spans.last()
+ && last_name != name
+ {
+ let descr = macro_kind.descr();
+ format!(
+ " which comes from the expansion of the {descr} `{last_name}`",
+ )
+ } else {
+ "".to_string()
+ };
+
+ let descr = macro_kind.descr();
+ let msg = format!(
+ "this {level} originates in the {descr} `{name}`{and_then} \
+ (in Nightly builds, run with -Z macro-backtrace for more info)",
+ );
+
+ children.push(SubDiagnostic {
+ level: Level::Note,
+ message: vec![(DiagnosticMessage::Str(msg), Style::NoStyle)],
+ span: MultiSpan::new(),
+ render_span: None,
+ });
+ }
+ }
+ }
+
+ fn render_multispans_macro_backtrace(
+ &self,
+ span: &mut MultiSpan,
+ children: &mut Vec<SubDiagnostic>,
+ backtrace: bool,
+ ) {
+ for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
+ self.render_multispan_macro_backtrace(span, backtrace);
+ }
+ }
+
+ fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
+ let mut new_labels: Vec<(Span, String)> = vec![];
+
+ for &sp in span.primary_spans() {
+ if sp.is_dummy() {
+ continue;
+ }
+
+ // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
+ // entries we don't want to print, to make sure the indices being
+ // printed are contiguous (or omitted if there's only one entry).
+ let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
+ for (i, trace) in macro_backtrace.iter().rev().enumerate() {
+ if trace.def_site.is_dummy() {
+ continue;
+ }
+
+ if always_backtrace && !matches!(trace.kind, ExpnKind::Inlined) {
+ new_labels.push((
+ trace.def_site,
+ format!(
+ "in this expansion of `{}`{}",
+ trace.kind.descr(),
+ if macro_backtrace.len() > 1 {
+ // if macro_backtrace.len() == 1 it'll be
+ // pointed at by "in this macro invocation"
+ format!(" (#{})", i + 1)
+ } else {
+ String::new()
+ },
+ ),
+ ));
+ }
+
+ // Don't add a label on the call site if the diagnostic itself
+ // already points to (a part of) that call site, as the label
+ // is meant for showing the relevant invocation when the actual
+ // diagnostic is pointing to some part of macro definition.
+ //
+ // This also handles the case where an external span got replaced
+ // with the call site span by `fix_multispans_in_extern_macros`.
+ //
+ // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
+ // "in this expansion of" label above is always added in that mode,
+ // and it needs an "in this macro invocation" label to match that.
+ let redundant_span = trace.call_site.contains(sp);
+
+ if !redundant_span || always_backtrace {
+ let msg: Cow<'static, _> = match trace.kind {
+ ExpnKind::Macro(MacroKind::Attr, _) => {
+ "this procedural macro expansion".into()
+ }
+ ExpnKind::Macro(MacroKind::Derive, _) => {
+ "this derive macro expansion".into()
+ }
+ ExpnKind::Macro(MacroKind::Bang, _) => "this macro invocation".into(),
+ ExpnKind::Inlined => "this inlined function call".into(),
+ ExpnKind::Root => "the crate root".into(),
+ ExpnKind::AstPass(kind) => kind.descr().into(),
+ ExpnKind::Desugaring(kind) => {
+ format!("this {} desugaring", kind.descr()).into()
+ }
+ };
+ new_labels.push((
+ trace.call_site,
+ format!(
+ "in {}{}",
+ msg,
+ if macro_backtrace.len() > 1 && always_backtrace {
+ // only specify order when the macro
+ // backtrace is multiple levels deep
+ format!(" (#{})", i + 1)
+ } else {
+ String::new()
+ },
+ ),
+ ));
+ }
+ if !always_backtrace {
+ break;
+ }
+ }
+ }
+
+ for (label_span, label_text) in new_labels {
+ span.push_span_label(label_span, label_text);
+ }
+ }
+
+ // This does a small "fix" for multispans by looking to see if it can find any that
+ // point directly at external macros. Since these are often difficult to read,
+ // this will change the span to point at the use site.
+ fn fix_multispans_in_extern_macros(
+ &self,
+ source_map: &Option<Lrc<SourceMap>>,
+ span: &mut MultiSpan,
+ children: &mut Vec<SubDiagnostic>,
+ ) {
+ let Some(source_map) = source_map else { return };
+ debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
+ self.fix_multispan_in_extern_macros(source_map, span);
+ for child in children.iter_mut() {
+ self.fix_multispan_in_extern_macros(source_map, &mut child.span);
+ }
+ debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
+ }
+
+ // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
+ // Since these locations are often difficult to read,
+ // we move these spans from the external macros to their corresponding use site.
+ fn fix_multispan_in_extern_macros(&self, source_map: &Lrc<SourceMap>, span: &mut MultiSpan) {
+ // First, find all the spans in external macros and point instead at their use site.
+ let replacements: Vec<(Span, Span)> = span
+ .primary_spans()
+ .iter()
+ .copied()
+ .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
+ .filter_map(|sp| {
+ if !sp.is_dummy() && source_map.is_imported(sp) {
+ let maybe_callsite = sp.source_callsite();
+ if sp != maybe_callsite {
+ return Some((sp, maybe_callsite));
+ }
+ }
+ None
+ })
+ .collect();
+
+ // After we have them, make sure we replace these 'bad' def sites with their use sites.
+ for (from, to) in replacements {
+ span.replace(from, to);
+ }
+ }
+}
+
+impl Emitter for EmitterWriter {
+ fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+ self.sm.as_ref()
+ }
+
+ fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+ self.fluent_bundle.as_ref()
+ }
+
+ fn fallback_fluent_bundle(&self) -> &FluentBundle {
+ &**self.fallback_bundle
+ }
+
+ fn emit_diagnostic(&mut self, diag: &Diagnostic) {
+ let fluent_args = self.to_fluent_args(diag.args());
+
+ let mut children = diag.children.clone();
+ let (mut primary_span, suggestions) = self.primary_span_formatted(&diag, &fluent_args);
+ debug!("emit_diagnostic: suggestions={:?}", suggestions);
+
+ self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
+ &self.sm,
+ &mut primary_span,
+ &mut children,
+ &diag.level,
+ self.macro_backtrace,
+ );
+
+ self.emit_messages_default(
+ &diag.level,
+ &diag.message,
+ &fluent_args,
+ &diag.code,
+ &primary_span,
+ &children,
+ &suggestions,
+ );
+ }
+
+ fn should_show_explain(&self) -> bool {
+ !self.short_message
+ }
+
+ fn supports_color(&self) -> bool {
+ self.dst.supports_color()
+ }
+}
+
+/// An emitter that does nothing when emitting a non-fatal diagnostic.
+/// Fatal diagnostics are forwarded to `fatal_handler` to avoid silent
+/// failures of rustc, as witnessed e.g. in issue #89358.
+pub struct SilentEmitter {
+ pub fatal_handler: Handler,
+ pub fatal_note: Option<String>,
+}
+
+impl Emitter for SilentEmitter {
+ fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+ None
+ }
+
+ fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+ None
+ }
+
+ fn fallback_fluent_bundle(&self) -> &FluentBundle {
+ panic!("silent emitter attempted to translate message")
+ }
+
+ fn emit_diagnostic(&mut self, d: &Diagnostic) {
+ if d.level == Level::Fatal {
+ let mut d = d.clone();
+ if let Some(ref note) = self.fatal_note {
+ d.note(note);
+ }
+ self.fatal_handler.emit_diagnostic(&mut d);
+ }
+ }
+}
+
+/// Maximum number of suggestions to be shown
+///
+/// Arbitrary, but taken from trait import suggestion limit
+pub const MAX_SUGGESTIONS: usize = 4;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ColorConfig {
+ Auto,
+ Always,
+ Never,
+}
+
+impl ColorConfig {
+ fn to_color_choice(self) -> ColorChoice {
+ match self {
+ ColorConfig::Always => {
+ if atty::is(atty::Stream::Stderr) {
+ ColorChoice::Always
+ } else {
+ ColorChoice::AlwaysAnsi
+ }
+ }
+ ColorConfig::Never => ColorChoice::Never,
+ ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
+ ColorConfig::Auto => ColorChoice::Never,
+ }
+ }
+ fn suggests_using_colors(self) -> bool {
+ match self {
+ ColorConfig::Always | ColorConfig::Auto => true,
+ ColorConfig::Never => false,
+ }
+ }
+}
+
+/// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
+pub struct EmitterWriter {
+ dst: Destination,
+ sm: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ short_message: bool,
+ teach: bool,
+ ui_testing: bool,
+ diagnostic_width: Option<usize>,
+
+ macro_backtrace: bool,
+}
+
+#[derive(Debug)]
+pub struct FileWithAnnotatedLines {
+ pub file: Lrc<SourceFile>,
+ pub lines: Vec<Line>,
+ multiline_depth: usize,
+}
+
+impl EmitterWriter {
+ pub fn stderr(
+ color_config: ColorConfig,
+ source_map: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ short_message: bool,
+ teach: bool,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> EmitterWriter {
+ let dst = Destination::from_stderr(color_config);
+ EmitterWriter {
+ dst,
+ sm: source_map,
+ fluent_bundle,
+ fallback_bundle,
+ short_message,
+ teach,
+ ui_testing: false,
+ diagnostic_width,
+ macro_backtrace,
+ }
+ }
+
+ pub fn new(
+ dst: Box<dyn Write + Send>,
+ source_map: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ short_message: bool,
+ teach: bool,
+ colored: bool,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> EmitterWriter {
+ EmitterWriter {
+ dst: Raw(dst, colored),
+ sm: source_map,
+ fluent_bundle,
+ fallback_bundle,
+ short_message,
+ teach,
+ ui_testing: false,
+ diagnostic_width,
+ macro_backtrace,
+ }
+ }
+
+ pub fn ui_testing(mut self, ui_testing: bool) -> Self {
+ self.ui_testing = ui_testing;
+ self
+ }
+
+ fn maybe_anonymized(&self, line_num: usize) -> Cow<'static, str> {
+ if self.ui_testing {
+ Cow::Borrowed(ANONYMIZED_LINE_NUM)
+ } else {
+ Cow::Owned(line_num.to_string())
+ }
+ }
+
+ fn draw_line(
+ &self,
+ buffer: &mut StyledBuffer,
+ source_string: &str,
+ line_index: usize,
+ line_offset: usize,
+ width_offset: usize,
+ code_offset: usize,
+ margin: Margin,
+ ) {
+ // Tabs are assumed to have been replaced by spaces in calling code.
+ debug_assert!(!source_string.contains('\t'));
+ let line_len = source_string.len();
+ // Create the source line we will highlight.
+ let left = margin.left(line_len);
+ let right = margin.right(line_len);
+ // On long lines, we strip the source line, accounting for unicode.
+ let mut taken = 0;
+ let code: String = source_string
+ .chars()
+ .skip(left)
+ .take_while(|ch| {
+ // Make sure that the trimming on the right will fall within the terminal width.
+ // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
+ // For now, just accept that sometimes the code line will be longer than desired.
+ let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
+ if taken + next > right - left {
+ return false;
+ }
+ taken += next;
+ true
+ })
+ .collect();
+ buffer.puts(line_offset, code_offset, &code, Style::Quotation);
+ if margin.was_cut_left() {
+ // We have stripped some code/whitespace from the beginning, make it clear.
+ buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
+ }
+ if margin.was_cut_right(line_len) {
+ // We have stripped some code after the right-most span end, make it clear we did so.
+ buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
+ }
+ buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
+
+ draw_col_separator_no_space(buffer, line_offset, width_offset - 2);
+ }
+
+ fn render_source_line(
+ &self,
+ buffer: &mut StyledBuffer,
+ file: Lrc<SourceFile>,
+ line: &Line,
+ width_offset: usize,
+ code_offset: usize,
+ margin: Margin,
+ ) -> Vec<(usize, Style)> {
+ // Draw:
+ //
+ // LL | ... code ...
+ // | ^^-^ span label
+ // | |
+ // | secondary span label
+ //
+ // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
+ // | | | |
+ // | | | actual code found in your source code and the spans we use to mark it
+ // | | when there's too much wasted space to the left, trim it
+ // | vertical divider between the column number and the code
+ // column number
+
+ if line.line_index == 0 {
+ return Vec::new();
+ }
+
+ let source_string = match file.get_line(line.line_index - 1) {
+ Some(s) => normalize_whitespace(&*s),
+ None => return Vec::new(),
+ };
+
+ let line_offset = buffer.num_lines();
+
+ // Left trim
+ let left = margin.left(source_string.len());
+
+ // Account for unicode characters of width !=0 that were removed.
+ let left = source_string
+ .chars()
+ .take(left)
+ .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
+ .sum();
+
+ self.draw_line(
+ buffer,
+ &source_string,
+ line.line_index,
+ line_offset,
+ width_offset,
+ code_offset,
+ margin,
+ );
+
+ // Special case when there's only one annotation involved, it is the start of a multiline
+ // span and there's no text at the beginning of the code line. Instead of doing the whole
+ // graph:
+ //
+ // 2 | fn foo() {
+ // | _^
+ // 3 | |
+ // 4 | | }
+ // | |_^ test
+ //
+ // we simplify the output to:
+ //
+ // 2 | / fn foo() {
+ // 3 | |
+ // 4 | | }
+ // | |_^ test
+ if let [ann] = &line.annotations[..] {
+ if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
+ if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
+ let style = if ann.is_primary {
+ Style::UnderlinePrimary
+ } else {
+ Style::UnderlineSecondary
+ };
+ buffer.putc(line_offset, width_offset + depth - 1, '/', style);
+ return vec![(depth, style)];
+ }
+ }
+ }
+
+ // We want to display like this:
+ //
+ // vec.push(vec.pop().unwrap());
+ // --- ^^^ - previous borrow ends here
+ // | |
+ // | error occurs here
+ // previous borrow of `vec` occurs here
+ //
+ // But there are some weird edge cases to be aware of:
+ //
+ // vec.push(vec.pop().unwrap());
+ // -------- - previous borrow ends here
+ // ||
+ // |this makes no sense
+ // previous borrow of `vec` occurs here
+ //
+ // For this reason, we group the lines into "highlight lines"
+ // and "annotations lines", where the highlight lines have the `^`.
+
+ // Sort the annotations by (start, end col)
+ // The labels are reversed, sort and then reversed again.
+ // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
+ // the letter signifies the span. Here we are only sorting by the
+ // span and hence, the order of the elements with the same span will
+ // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
+ // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
+ // still ordered first to last, but all the elements with different
+ // spans are ordered by their spans in last to first order. Last to
+ // first order is important, because the jiggly lines and | are on
+ // the left, so the rightmost span needs to be rendered first,
+ // otherwise the lines would end up needing to go over a message.
+
+ let mut annotations = line.annotations.clone();
+ annotations.sort_by_key(|a| Reverse(a.start_col));
+
+ // First, figure out where each label will be positioned.
+ //
+ // In the case where you have the following annotations:
+ //
+ // vec.push(vec.pop().unwrap());
+ // -------- - previous borrow ends here [C]
+ // ||
+ // |this makes no sense [B]
+ // previous borrow of `vec` occurs here [A]
+ //
+ // `annotations_position` will hold [(2, A), (1, B), (0, C)].
+ //
+ // We try, when possible, to stick the rightmost annotation at the end
+ // of the highlight line:
+ //
+ // vec.push(vec.pop().unwrap());
+ // --- --- - previous borrow ends here
+ //
+ // But sometimes that's not possible because one of the other
+ // annotations overlaps it. For example, from the test
+ // `span_overlap_label`, we have the following annotations
+ // (written on distinct lines for clarity):
+ //
+ // fn foo(x: u32) {
+ // --------------
+ // -
+ //
+ // In this case, we can't stick the rightmost-most label on
+ // the highlight line, or we would get:
+ //
+ // fn foo(x: u32) {
+ // -------- x_span
+ // |
+ // fn_span
+ //
+ // which is totally weird. Instead we want:
+ //
+ // fn foo(x: u32) {
+ // --------------
+ // | |
+ // | x_span
+ // fn_span
+ //
+ // which is...less weird, at least. In fact, in general, if
+ // the rightmost span overlaps with any other span, we should
+ // use the "hang below" version, so we can at least make it
+ // clear where the span *starts*. There's an exception for this
+ // logic, when the labels do not have a message:
+ //
+ // fn foo(x: u32) {
+ // --------------
+ // |
+ // x_span
+ //
+ // instead of:
+ //
+ // fn foo(x: u32) {
+ // --------------
+ // | |
+ // | x_span
+ // <EMPTY LINE>
+ //
+ let mut annotations_position = vec![];
+ let mut line_len = 0;
+ let mut p = 0;
+ for (i, annotation) in annotations.iter().enumerate() {
+ for (j, next) in annotations.iter().enumerate() {
+ if overlaps(next, annotation, 0) // This label overlaps with another one and both
+ && annotation.has_label() // take space (they have text and are not
+ && j > i // multiline lines).
+ && p == 0
+ // We're currently on the first line, move the label one line down
+ {
+ // If we're overlapping with an un-labelled annotation with the same span
+ // we can just merge them in the output
+ if next.start_col == annotation.start_col
+ && next.end_col == annotation.end_col
+ && !next.has_label()
+ {
+ continue;
+ }
+
+ // This annotation needs a new line in the output.
+ p += 1;
+ break;
+ }
+ }
+ annotations_position.push((p, annotation));
+ for (j, next) in annotations.iter().enumerate() {
+ if j > i {
+ let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
+ if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
+ // line if they overlap including padding, to
+ // avoid situations like:
+ //
+ // fn foo(x: u32) {
+ // -------^------
+ // | |
+ // fn_spanx_span
+ //
+ && annotation.has_label() // Both labels must have some text, otherwise
+ && next.has_label()) // they are not overlapping.
+ // Do not add a new line if this annotation
+ // or the next are vertical line placeholders.
+ || (annotation.takes_space() // If either this or the next annotation is
+ && next.has_label()) // multiline start/end, move it to a new line
+ || (annotation.has_label() // so as not to overlap the horizontal lines.
+ && next.takes_space())
+ || (annotation.takes_space() && next.takes_space())
+ || (overlaps(next, annotation, l)
+ && next.end_col <= annotation.end_col
+ && next.has_label()
+ && p == 0)
+ // Avoid #42595.
+ {
+ // This annotation needs a new line in the output.
+ p += 1;
+ break;
+ }
+ }
+ }
+ line_len = max(line_len, p);
+ }
+
+ if line_len != 0 {
+ line_len += 1;
+ }
+
+ // If there are no annotations or the only annotations on this line are
+ // MultilineLine, then there's only code being shown, stop processing.
+ if line.annotations.iter().all(|a| a.is_line()) {
+ return vec![];
+ }
+
+ // Write the column separator.
+ //
+ // After this we will have:
+ //
+ // 2 | fn foo() {
+ // |
+ // |
+ // |
+ // 3 |
+ // 4 | }
+ // |
+ for pos in 0..=line_len {
+ draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
+ }
+
+ // Write the horizontal lines for multiline annotations
+ // (only the first and last lines need this).
+ //
+ // After this we will have:
+ //
+ // 2 | fn foo() {
+ // | __________
+ // |
+ // |
+ // 3 |
+ // 4 | }
+ // | _
+ for &(pos, annotation) in &annotations_position {
+ let style = if annotation.is_primary {
+ Style::UnderlinePrimary
+ } else {
+ Style::UnderlineSecondary
+ };
+ let pos = pos + 1;
+ match annotation.annotation_type {
+ AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
+ draw_range(
+ buffer,
+ '_',
+ line_offset + pos,
+ width_offset + depth,
+ (code_offset + annotation.start_col).saturating_sub(left),
+ style,
+ );
+ }
+ _ if self.teach => {
+ buffer.set_style_range(
+ line_offset,
+ (code_offset + annotation.start_col).saturating_sub(left),
+ (code_offset + annotation.end_col).saturating_sub(left),
+ style,
+ annotation.is_primary,
+ );
+ }
+ _ => {}
+ }
+ }
+
+ // Write the vertical lines for labels that are on a different line as the underline.
+ //
+ // After this we will have:
+ //
+ // 2 | fn foo() {
+ // | __________
+ // | | |
+ // | |
+ // 3 | |
+ // 4 | | }
+ // | |_
+ for &(pos, annotation) in &annotations_position {
+ let style = if annotation.is_primary {
+ Style::UnderlinePrimary
+ } else {
+ Style::UnderlineSecondary
+ };
+ let pos = pos + 1;
+
+ if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
+ for p in line_offset + 1..=line_offset + pos {
+ buffer.putc(
+ p,
+ (code_offset + annotation.start_col).saturating_sub(left),
+ '|',
+ style,
+ );
+ }
+ }
+ match annotation.annotation_type {
+ AnnotationType::MultilineStart(depth) => {
+ for p in line_offset + pos + 1..line_offset + line_len + 2 {
+ buffer.putc(p, width_offset + depth - 1, '|', style);
+ }
+ }
+ AnnotationType::MultilineEnd(depth) => {
+ for p in line_offset..=line_offset + pos {
+ buffer.putc(p, width_offset + depth - 1, '|', style);
+ }
+ }
+ _ => (),
+ }
+ }
+
+ // Write the labels on the annotations that actually have a label.
+ //
+ // After this we will have:
+ //
+ // 2 | fn foo() {
+ // | __________
+ // | |
+ // | something about `foo`
+ // 3 |
+ // 4 | }
+ // | _ test
+ for &(pos, annotation) in &annotations_position {
+ let style =
+ if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
+ let (pos, col) = if pos == 0 {
+ (pos + 1, (annotation.end_col + 1).saturating_sub(left))
+ } else {
+ (pos + 2, annotation.start_col.saturating_sub(left))
+ };
+ if let Some(ref label) = annotation.label {
+ buffer.puts(line_offset + pos, code_offset + col, &label, style);
+ }
+ }
+
+ // Sort from biggest span to smallest span so that smaller spans are
+ // represented in the output:
+ //
+ // x | fn foo()
+ // | ^^^---^^
+ // | | |
+ // | | something about `foo`
+ // | something about `fn foo()`
+ annotations_position.sort_by_key(|(_, ann)| {
+ // Decreasing order. When annotations share the same length, prefer `Primary`.
+ (Reverse(ann.len()), ann.is_primary)
+ });
+
+ // Write the underlines.
+ //
+ // After this we will have:
+ //
+ // 2 | fn foo() {
+ // | ____-_____^
+ // | |
+ // | something about `foo`
+ // 3 |
+ // 4 | }
+ // | _^ test
+ for &(_, annotation) in &annotations_position {
+ let (underline, style) = if annotation.is_primary {
+ ('^', Style::UnderlinePrimary)
+ } else {
+ ('-', Style::UnderlineSecondary)
+ };
+ for p in annotation.start_col..annotation.end_col {
+ buffer.putc(
+ line_offset + 1,
+ (code_offset + p).saturating_sub(left),
+ underline,
+ style,
+ );
+ }
+ }
+ annotations_position
+ .iter()
+ .filter_map(|&(_, annotation)| match annotation.annotation_type {
+ AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
+ let style = if annotation.is_primary {
+ Style::LabelPrimary
+ } else {
+ Style::LabelSecondary
+ };
+ Some((p, style))
+ }
+ _ => None,
+ })
+ .collect::<Vec<_>>()
+ }
+
+ fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
+ let Some(ref sm) = self.sm else {
+ return 0;
+ };
+
+ let will_be_emitted = |span: Span| {
+ !span.is_dummy() && {
+ let file = sm.lookup_source_file(span.hi());
+ sm.ensure_source_file_source_present(file)
+ }
+ };
+
+ let mut max = 0;
+ for primary_span in msp.primary_spans() {
+ if will_be_emitted(*primary_span) {
+ let hi = sm.lookup_char_pos(primary_span.hi());
+ max = (hi.line).max(max);
+ }
+ }
+ if !self.short_message {
+ for span_label in msp.span_labels() {
+ if will_be_emitted(span_label.span) {
+ let hi = sm.lookup_char_pos(span_label.span.hi());
+ max = (hi.line).max(max);
+ }
+ }
+ }
+
+ max
+ }
+
+ fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
+ let primary = self.get_multispan_max_line_num(span);
+ children
+ .iter()
+ .map(|sub| self.get_multispan_max_line_num(&sub.span))
+ .max()
+ .unwrap_or(0)
+ .max(primary)
+ }
+
+ /// Adds a left margin to every line but the first, given a padding length and the label being
+ /// displayed, keeping the provided highlighting.
+ fn msg_to_buffer(
+ &self,
+ buffer: &mut StyledBuffer,
+ msg: &[(DiagnosticMessage, Style)],
+ args: &FluentArgs<'_>,
+ padding: usize,
+ label: &str,
+ override_style: Option<Style>,
+ ) {
+ // The extra 5 ` ` is padding that's always needed to align to the `note: `:
+ //
+ // error: message
+ // --> file.rs:13:20
+ // |
+ // 13 | <CODE>
+ // | ^^^^
+ // |
+ // = note: multiline
+ // message
+ // ++^^^----xx
+ // | | | |
+ // | | | magic `2`
+ // | | length of label
+ // | magic `3`
+ // `max_line_num_len`
+ let padding = " ".repeat(padding + label.len() + 5);
+
+ /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
+ fn style_or_override(style: Style, override_: Option<Style>) -> Style {
+ match (style, override_) {
+ (Style::NoStyle, Some(override_)) => override_,
+ _ => style,
+ }
+ }
+
+ let mut line_number = 0;
+
+ // Provided the following diagnostic message:
+ //
+ // let msg = vec![
+ // ("
+ // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
+ // ("looks", Style::Highlight),
+ // ("with\nvery ", Style::NoStyle),
+ // ("weird", Style::Highlight),
+ // (" formats\n", Style::NoStyle),
+ // ("see?", Style::Highlight),
+ // ];
+ //
+ // the expected output on a note is (* surround the highlighted text)
+ //
+ // = note: highlighted multiline
+ // string to
+ // see how it *looks* with
+ // very *weird* formats
+ // see?
+ for &(ref text, ref style) in msg.iter() {
+ let text = self.translate_message(text, args);
+ let lines = text.split('\n').collect::<Vec<_>>();
+ if lines.len() > 1 {
+ for (i, line) in lines.iter().enumerate() {
+ if i != 0 {
+ line_number += 1;
+ buffer.append(line_number, &padding, Style::NoStyle);
+ }
+ buffer.append(line_number, line, style_or_override(*style, override_style));
+ }
+ } else {
+ buffer.append(line_number, &text, style_or_override(*style, override_style));
+ }
+ }
+ }
+
+ fn emit_message_default(
+ &mut self,
+ msp: &MultiSpan,
+ msg: &[(DiagnosticMessage, Style)],
+ args: &FluentArgs<'_>,
+ code: &Option<DiagnosticId>,
+ level: &Level,
+ max_line_num_len: usize,
+ is_secondary: bool,
+ ) -> io::Result<()> {
+ let mut buffer = StyledBuffer::new();
+
+ if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
+ {
+ // This is a secondary message with no span info
+ for _ in 0..max_line_num_len {
+ buffer.prepend(0, " ", Style::NoStyle);
+ }
+ draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
+ if *level != Level::FailureNote {
+ buffer.append(0, level.to_str(), Style::MainHeaderMsg);
+ buffer.append(0, ": ", Style::NoStyle);
+ }
+ self.msg_to_buffer(&mut buffer, msg, args, max_line_num_len, "note", None);
+ } else {
+ let mut label_width = 0;
+ // The failure note level itself does not provide any useful diagnostic information
+ if *level != Level::FailureNote {
+ buffer.append(0, level.to_str(), Style::Level(*level));
+ label_width += level.to_str().len();
+ }
+ // only render error codes, not lint codes
+ if let Some(DiagnosticId::Error(ref code)) = *code {
+ buffer.append(0, "[", Style::Level(*level));
+ buffer.append(0, &code, Style::Level(*level));
+ buffer.append(0, "]", Style::Level(*level));
+ label_width += 2 + code.len();
+ }
+ let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
+ if *level != Level::FailureNote {
+ buffer.append(0, ": ", header_style);
+ label_width += 2;
+ }
+ for &(ref text, _) in msg.iter() {
+ let text = self.translate_message(text, args);
+ // Account for newlines to align output to its label.
+ for (line, text) in normalize_whitespace(&text).lines().enumerate() {
+ buffer.append(
+ 0 + line,
+ &format!(
+ "{}{}",
+ if line == 0 { String::new() } else { " ".repeat(label_width) },
+ text
+ ),
+ header_style,
+ );
+ }
+ }
+ }
+
+ let mut annotated_files = FileWithAnnotatedLines::collect_annotations(self, args, msp);
+
+ // Make sure our primary file comes first
+ let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
+ (self.sm.as_ref(), msp.primary_span().as_ref())
+ {
+ if !primary_span.is_dummy() {
+ (sm.lookup_char_pos(primary_span.lo()), sm)
+ } else {
+ emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
+ return Ok(());
+ }
+ } else {
+ // If we don't have span information, emit and exit
+ emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
+ return Ok(());
+ };
+ if let Ok(pos) =
+ annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
+ {
+ annotated_files.swap(0, pos);
+ }
+
+ // Print out the annotate source lines that correspond with the error
+ for annotated_file in annotated_files {
+ // we can't annotate anything if the source is unavailable.
+ if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
+ continue;
+ }
+
+ // print out the span location and spacer before we print the annotated source
+ // to do this, we need to know if this span will be primary
+ let is_primary = primary_lo.file.name == annotated_file.file.name;
+ if is_primary {
+ let loc = primary_lo.clone();
+ if !self.short_message {
+ // remember where we are in the output buffer for easy reference
+ let buffer_msg_line_offset = buffer.num_lines();
+
+ buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
+ buffer.append(
+ buffer_msg_line_offset,
+ &format!(
+ "{}:{}:{}",
+ sm.filename_for_diagnostics(&loc.file.name),
+ sm.doctest_offset_line(&loc.file.name, loc.line),
+ loc.col.0 + 1,
+ ),
+ Style::LineAndColumn,
+ );
+ for _ in 0..max_line_num_len {
+ buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
+ }
+ } else {
+ buffer.prepend(
+ 0,
+ &format!(
+ "{}:{}:{}: ",
+ sm.filename_for_diagnostics(&loc.file.name),
+ sm.doctest_offset_line(&loc.file.name, loc.line),
+ loc.col.0 + 1,
+ ),
+ Style::LineAndColumn,
+ );
+ }
+ } else if !self.short_message {
+ // remember where we are in the output buffer for easy reference
+ let buffer_msg_line_offset = buffer.num_lines();
+
+ // Add spacing line
+ draw_col_separator_no_space(
+ &mut buffer,
+ buffer_msg_line_offset,
+ max_line_num_len + 1,
+ );
+
+ // Then, the secondary file indicator
+ buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
+ let loc = if let Some(first_line) = annotated_file.lines.first() {
+ let col = if let Some(first_annotation) = first_line.annotations.first() {
+ format!(":{}", first_annotation.start_col + 1)
+ } else {
+ String::new()
+ };
+ format!(
+ "{}:{}{}",
+ sm.filename_for_diagnostics(&annotated_file.file.name),
+ sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
+ col
+ )
+ } else {
+ format!("{}", sm.filename_for_diagnostics(&annotated_file.file.name))
+ };
+ buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
+ for _ in 0..max_line_num_len {
+ buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
+ }
+ }
+
+ if !self.short_message {
+ // Put in the spacer between the location and annotated source
+ let buffer_msg_line_offset = buffer.num_lines();
+ draw_col_separator_no_space(
+ &mut buffer,
+ buffer_msg_line_offset,
+ max_line_num_len + 1,
+ );
+
+ // Contains the vertical lines' positions for active multiline annotations
+ let mut multilines = FxHashMap::default();
+
+ // Get the left-side margin to remove it
+ let mut whitespace_margin = usize::MAX;
+ for line_idx in 0..annotated_file.lines.len() {
+ let file = annotated_file.file.clone();
+ let line = &annotated_file.lines[line_idx];
+ if let Some(source_string) = file.get_line(line.line_index - 1) {
+ let leading_whitespace = source_string
+ .chars()
+ .take_while(|c| c.is_whitespace())
+ .map(|c| {
+ match c {
+ // Tabs are displayed as 4 spaces
+ '\t' => 4,
+ _ => 1,
+ }
+ })
+ .sum();
+ if source_string.chars().any(|c| !c.is_whitespace()) {
+ whitespace_margin = min(whitespace_margin, leading_whitespace);
+ }
+ }
+ }
+ if whitespace_margin == usize::MAX {
+ whitespace_margin = 0;
+ }
+
+ // Left-most column any visible span points at.
+ let mut span_left_margin = usize::MAX;
+ for line in &annotated_file.lines {
+ for ann in &line.annotations {
+ span_left_margin = min(span_left_margin, ann.start_col);
+ span_left_margin = min(span_left_margin, ann.end_col);
+ }
+ }
+ if span_left_margin == usize::MAX {
+ span_left_margin = 0;
+ }
+
+ // Right-most column any visible span points at.
+ let mut span_right_margin = 0;
+ let mut label_right_margin = 0;
+ let mut max_line_len = 0;
+ for line in &annotated_file.lines {
+ max_line_len = max(
+ max_line_len,
+ annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
+ );
+ for ann in &line.annotations {
+ span_right_margin = max(span_right_margin, ann.start_col);
+ span_right_margin = max(span_right_margin, ann.end_col);
+ // FIXME: account for labels not in the same line
+ let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
+ label_right_margin = max(label_right_margin, ann.end_col + label_right);
+ }
+ }
+
+ let width_offset = 3 + max_line_num_len;
+ let code_offset = if annotated_file.multiline_depth == 0 {
+ width_offset
+ } else {
+ width_offset + annotated_file.multiline_depth + 1
+ };
+
+ let column_width = if let Some(width) = self.diagnostic_width {
+ width.saturating_sub(code_offset)
+ } else if self.ui_testing {
+ DEFAULT_COLUMN_WIDTH
+ } else {
+ termize::dimensions()
+ .map(|(w, _)| w.saturating_sub(code_offset))
+ .unwrap_or(DEFAULT_COLUMN_WIDTH)
+ };
+
+ let margin = Margin::new(
+ whitespace_margin,
+ span_left_margin,
+ span_right_margin,
+ label_right_margin,
+ column_width,
+ max_line_len,
+ );
+
+ // Next, output the annotate source for this file
+ for line_idx in 0..annotated_file.lines.len() {
+ let previous_buffer_line = buffer.num_lines();
+
+ let depths = self.render_source_line(
+ &mut buffer,
+ annotated_file.file.clone(),
+ &annotated_file.lines[line_idx],
+ width_offset,
+ code_offset,
+ margin,
+ );
+
+ let mut to_add = FxHashMap::default();
+
+ for (depth, style) in depths {
+ if multilines.remove(&depth).is_none() {
+ to_add.insert(depth, style);
+ }
+ }
+
+ // Set the multiline annotation vertical lines to the left of
+ // the code in this line.
+ for (depth, style) in &multilines {
+ for line in previous_buffer_line..buffer.num_lines() {
+ draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
+ }
+ }
+ // check to see if we need to print out or elide lines that come between
+ // this annotated line and the next one.
+ if line_idx < (annotated_file.lines.len() - 1) {
+ let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
+ - annotated_file.lines[line_idx].line_index;
+ if line_idx_delta > 2 {
+ let last_buffer_line_num = buffer.num_lines();
+ buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
+
+ // Set the multiline annotation vertical lines on `...` bridging line.
+ for (depth, style) in &multilines {
+ draw_multiline_line(
+ &mut buffer,
+ last_buffer_line_num,
+ width_offset,
+ *depth,
+ *style,
+ );
+ }
+ } else if line_idx_delta == 2 {
+ let unannotated_line = annotated_file
+ .file
+ .get_line(annotated_file.lines[line_idx].line_index)
+ .unwrap_or_else(|| Cow::from(""));
+
+ let last_buffer_line_num = buffer.num_lines();
+
+ self.draw_line(
+ &mut buffer,
+ &normalize_whitespace(&unannotated_line),
+ annotated_file.lines[line_idx + 1].line_index - 1,
+ last_buffer_line_num,
+ width_offset,
+ code_offset,
+ margin,
+ );
+
+ for (depth, style) in &multilines {
+ draw_multiline_line(
+ &mut buffer,
+ last_buffer_line_num,
+ width_offset,
+ *depth,
+ *style,
+ );
+ }
+ }
+ }
+
+ multilines.extend(&to_add);
+ }
+ }
+ }
+
+ // final step: take our styled buffer, render it, then output it
+ emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
+
+ Ok(())
+ }
+
+ fn emit_suggestion_default(
+ &mut self,
+ span: &MultiSpan,
+ suggestion: &CodeSuggestion,
+ args: &FluentArgs<'_>,
+ level: &Level,
+ max_line_num_len: usize,
+ ) -> io::Result<()> {
+ let Some(ref sm) = self.sm else {
+ return Ok(());
+ };
+
+ // Render the replacements for each suggestion
+ let suggestions = suggestion.splice_lines(&**sm);
+ debug!("emit_suggestion_default: suggestions={:?}", suggestions);
+
+ if suggestions.is_empty() {
+ // Suggestions coming from macros can have malformed spans. This is a heavy handed
+ // approach to avoid ICEs by ignoring the suggestion outright.
+ return Ok(());
+ }
+
+ let mut buffer = StyledBuffer::new();
+
+ // Render the suggestion message
+ buffer.append(0, level.to_str(), Style::Level(*level));
+ buffer.append(0, ": ", Style::HeaderMsg);
+
+ self.msg_to_buffer(
+ &mut buffer,
+ &[(suggestion.msg.to_owned(), Style::NoStyle)],
+ args,
+ max_line_num_len,
+ "suggestion",
+ Some(Style::HeaderMsg),
+ );
+
+ let mut row_num = 2;
+ draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
+ let mut notice_capitalization = false;
+ for (complete, parts, highlights, only_capitalization) in
+ suggestions.iter().take(MAX_SUGGESTIONS)
+ {
+ notice_capitalization |= only_capitalization;
+
+ let has_deletion = parts.iter().any(|p| p.is_deletion());
+ let is_multiline = complete.lines().count() > 1;
+
+ if let Some(span) = span.primary_span() {
+ // Compare the primary span of the diagnostic with the span of the suggestion
+ // being emitted. If they belong to the same file, we don't *need* to show the
+ // file name, saving in verbosity, but if it *isn't* we do need it, otherwise we're
+ // telling users to make a change but not clarifying *where*.
+ let loc = sm.lookup_char_pos(parts[0].span.lo());
+ if loc.file.name != sm.span_to_filename(span) && loc.file.name.is_real() {
+ buffer.puts(row_num - 1, 0, "--> ", Style::LineNumber);
+ buffer.append(
+ row_num - 1,
+ &format!(
+ "{}:{}:{}",
+ sm.filename_for_diagnostics(&loc.file.name),
+ sm.doctest_offset_line(&loc.file.name, loc.line),
+ loc.col.0 + 1,
+ ),
+ Style::LineAndColumn,
+ );
+ for _ in 0..max_line_num_len {
+ buffer.prepend(row_num - 1, " ", Style::NoStyle);
+ }
+ row_num += 1;
+ }
+ }
+ let show_code_change = if has_deletion && !is_multiline {
+ DisplaySuggestion::Diff
+ } else if (parts.len() != 1 || parts[0].snippet.trim() != complete.trim())
+ && !is_multiline
+ {
+ DisplaySuggestion::Underline
+ } else {
+ DisplaySuggestion::None
+ };
+
+ if let DisplaySuggestion::Diff = show_code_change {
+ row_num += 1;
+ }
+
+ let file_lines = sm
+ .span_to_lines(parts[0].span)
+ .expect("span_to_lines failed when emitting suggestion");
+
+ assert!(!file_lines.lines.is_empty() || parts[0].span.is_dummy());
+
+ let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
+ draw_col_separator_no_space(&mut buffer, row_num - 1, max_line_num_len + 1);
+ let mut lines = complete.lines();
+ if lines.clone().next().is_none() {
+ // Account for a suggestion to completely remove a line(s) with whitespace (#94192).
+ let line_end = sm.lookup_char_pos(parts[0].span.hi()).line;
+ for line in line_start..=line_end {
+ buffer.puts(
+ row_num - 1 + line - line_start,
+ 0,
+ &self.maybe_anonymized(line),
+ Style::LineNumber,
+ );
+ buffer.puts(
+ row_num - 1 + line - line_start,
+ max_line_num_len + 1,
+ "- ",
+ Style::Removal,
+ );
+ buffer.puts(
+ row_num - 1 + line - line_start,
+ max_line_num_len + 3,
+ &normalize_whitespace(&*file_lines.file.get_line(line - 1).unwrap()),
+ Style::Removal,
+ );
+ }
+ row_num += line_end - line_start;
+ }
+ let mut unhighlighted_lines = Vec::new();
+ for (line_pos, (line, highlight_parts)) in lines.by_ref().zip(highlights).enumerate() {
+ debug!(%line_pos, %line, ?highlight_parts);
+
+ // Remember lines that are not highlighted to hide them if needed
+ if highlight_parts.is_empty() {
+ unhighlighted_lines.push((line_pos, line));
+ continue;
+ }
+
+ match unhighlighted_lines.len() {
+ 0 => (),
+ // Since we show first line, "..." line and last line,
+ // There is no reason to hide if there are 3 or less lines
+ // (because then we just replace a line with ... which is
+ // not helpful)
+ n if n <= 3 => unhighlighted_lines.drain(..).for_each(|(p, l)| {
+ self.draw_code_line(
+ &mut buffer,
+ &mut row_num,
+ &Vec::new(),
+ p,
+ l,
+ line_start,
+ show_code_change,
+ max_line_num_len,
+ &file_lines,
+ is_multiline,
+ )
+ }),
+ // Print first unhighlighted line, "..." and last unhighlighted line, like so:
+ //
+ // LL | this line was highlighted
+ // LL | this line is just for context
+ // ...
+ // LL | this line is just for context
+ // LL | this line was highlighted
+ _ => {
+ let last_line = unhighlighted_lines.pop();
+ let first_line = unhighlighted_lines.drain(..).next();
+
+ first_line.map(|(p, l)| {
+ self.draw_code_line(
+ &mut buffer,
+ &mut row_num,
+ &Vec::new(),
+ p,
+ l,
+ line_start,
+ show_code_change,
+ max_line_num_len,
+ &file_lines,
+ is_multiline,
+ )
+ });
+
+ buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
+ row_num += 1;
+
+ last_line.map(|(p, l)| {
+ self.draw_code_line(
+ &mut buffer,
+ &mut row_num,
+ &Vec::new(),
+ p,
+ l,
+ line_start,
+ show_code_change,
+ max_line_num_len,
+ &file_lines,
+ is_multiline,
+ )
+ });
+ }
+ }
+
+ self.draw_code_line(
+ &mut buffer,
+ &mut row_num,
+ highlight_parts,
+ line_pos,
+ line,
+ line_start,
+ show_code_change,
+ max_line_num_len,
+ &file_lines,
+ is_multiline,
+ )
+ }
+
+ // This offset and the ones below need to be signed to account for replacement code
+ // that is shorter than the original code.
+ let mut offsets: Vec<(usize, isize)> = Vec::new();
+ // Only show an underline in the suggestions if the suggestion is not the
+ // entirety of the code being shown and the displayed code is not multiline.
+ if let DisplaySuggestion::Diff | DisplaySuggestion::Underline = show_code_change {
+ draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
+ for part in parts {
+ let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
+ let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
+
+ // Do not underline the leading...
+ let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
+ // ...or trailing spaces. Account for substitutions containing unicode
+ // characters.
+ let sub_len: usize = part
+ .snippet
+ .trim()
+ .chars()
+ .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
+ .sum();
+
+ let offset: isize = offsets
+ .iter()
+ .filter_map(
+ |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
+ )
+ .sum();
+ let underline_start = (span_start_pos + start) as isize + offset;
+ let underline_end = (span_start_pos + start + sub_len) as isize + offset;
+ assert!(underline_start >= 0 && underline_end >= 0);
+ let padding: usize = max_line_num_len + 3;
+ for p in underline_start..underline_end {
+ if let DisplaySuggestion::Underline = show_code_change {
+ // If this is a replacement, underline with `^`, if this is an addition
+ // underline with `+`.
+ buffer.putc(
+ row_num,
+ (padding as isize + p) as usize,
+ if part.is_addition(&sm) { '+' } else { '~' },
+ Style::Addition,
+ );
+ }
+ }
+ if let DisplaySuggestion::Diff = show_code_change {
+ // Colorize removal with red in diff format.
+ buffer.set_style_range(
+ row_num - 2,
+ (padding as isize + span_start_pos as isize) as usize,
+ (padding as isize + span_end_pos as isize) as usize,
+ Style::Removal,
+ true,
+ );
+ }
+
+ // length of the code after substitution
+ let full_sub_len = part
+ .snippet
+ .chars()
+ .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
+ .sum::<usize>() as isize;
+
+ // length of the code to be substituted
+ let snippet_len = span_end_pos as isize - span_start_pos as isize;
+ // For multiple substitutions, use the position *after* the previous
+ // substitutions have happened, only when further substitutions are
+ // located strictly after.
+ offsets.push((span_end_pos, full_sub_len - snippet_len));
+ }
+ row_num += 1;
+ }
+
+ // if we elided some lines, add an ellipsis
+ if lines.next().is_some() {
+ buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
+ } else if let DisplaySuggestion::None = show_code_change {
+ draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
+ row_num += 1;
+ }
+ }
+ if suggestions.len() > MAX_SUGGESTIONS {
+ let others = suggestions.len() - MAX_SUGGESTIONS;
+ let msg = format!("and {} other candidate{}", others, pluralize!(others));
+ buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
+ } else if notice_capitalization {
+ let msg = "notice the capitalization difference";
+ buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
+ }
+ emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
+ Ok(())
+ }
+
+ fn emit_messages_default(
+ &mut self,
+ level: &Level,
+ message: &[(DiagnosticMessage, Style)],
+ args: &FluentArgs<'_>,
+ code: &Option<DiagnosticId>,
+ span: &MultiSpan,
+ children: &[SubDiagnostic],
+ suggestions: &[CodeSuggestion],
+ ) {
+ let max_line_num_len = if self.ui_testing {
+ ANONYMIZED_LINE_NUM.len()
+ } else {
+ let n = self.get_max_line_num(span, children);
+ num_decimal_digits(n)
+ };
+
+ match self.emit_message_default(span, message, args, code, level, max_line_num_len, false) {
+ Ok(()) => {
+ if !children.is_empty()
+ || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
+ {
+ let mut buffer = StyledBuffer::new();
+ if !self.short_message {
+ draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
+ }
+ if let Err(e) = emit_to_destination(
+ &buffer.render(),
+ level,
+ &mut self.dst,
+ self.short_message,
+ ) {
+ panic!("failed to emit error: {}", e)
+ }
+ }
+ if !self.short_message {
+ for child in children {
+ let span = child.render_span.as_ref().unwrap_or(&child.span);
+ if let Err(err) = self.emit_message_default(
+ &span,
+ &child.message,
+ args,
+ &None,
+ &child.level,
+ max_line_num_len,
+ true,
+ ) {
+ panic!("failed to emit error: {}", err);
+ }
+ }
+ for sugg in suggestions {
+ if sugg.style == SuggestionStyle::CompletelyHidden {
+ // do not display this suggestion, it is meant only for tools
+ } else if sugg.style == SuggestionStyle::HideCodeAlways {
+ if let Err(e) = self.emit_message_default(
+ &MultiSpan::new(),
+ &[(sugg.msg.to_owned(), Style::HeaderMsg)],
+ args,
+ &None,
+ &Level::Help,
+ max_line_num_len,
+ true,
+ ) {
+ panic!("failed to emit error: {}", e);
+ }
+ } else if let Err(e) = self.emit_suggestion_default(
+ span,
+ sugg,
+ args,
+ &Level::Help,
+ max_line_num_len,
+ ) {
+ panic!("failed to emit error: {}", e);
+ };
+ }
+ }
+ }
+ Err(e) => panic!("failed to emit error: {}", e),
+ }
+
+ let mut dst = self.dst.writable();
+ match writeln!(dst) {
+ Err(e) => panic!("failed to emit error: {}", e),
+ _ => {
+ if let Err(e) = dst.flush() {
+ panic!("failed to emit error: {}", e)
+ }
+ }
+ }
+ }
+
+ fn draw_code_line(
+ &self,
+ buffer: &mut StyledBuffer,
+ row_num: &mut usize,
+ highlight_parts: &Vec<SubstitutionHighlight>,
+ line_pos: usize,
+ line: &str,
+ line_start: usize,
+ show_code_change: DisplaySuggestion,
+ max_line_num_len: usize,
+ file_lines: &FileLines,
+ is_multiline: bool,
+ ) {
+ // Print the span column to avoid confusion
+ buffer.puts(*row_num, 0, &self.maybe_anonymized(line_start + line_pos), Style::LineNumber);
+ if let DisplaySuggestion::Diff = show_code_change {
+ // Add the line number for both addition and removal to drive the point home.
+ //
+ // N - fn foo<A: T>(bar: A) {
+ // N + fn foo(bar: impl T) {
+ buffer.puts(
+ *row_num - 1,
+ 0,
+ &self.maybe_anonymized(line_start + line_pos),
+ Style::LineNumber,
+ );
+ buffer.puts(*row_num - 1, max_line_num_len + 1, "- ", Style::Removal);
+ buffer.puts(
+ *row_num - 1,
+ max_line_num_len + 3,
+ &normalize_whitespace(
+ &*file_lines.file.get_line(file_lines.lines[line_pos].line_index).unwrap(),
+ ),
+ Style::NoStyle,
+ );
+ buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
+ } else if is_multiline {
+ match &highlight_parts[..] {
+ [SubstitutionHighlight { start: 0, end }] if *end == line.len() => {
+ buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
+ }
+ [] => {
+ draw_col_separator(buffer, *row_num, max_line_num_len + 1);
+ }
+ _ => {
+ buffer.puts(*row_num, max_line_num_len + 1, "~ ", Style::Addition);
+ }
+ }
+ } else {
+ draw_col_separator(buffer, *row_num, max_line_num_len + 1);
+ }
+
+ // print the suggestion
+ buffer.append(*row_num, &normalize_whitespace(line), Style::NoStyle);
+
+ // Colorize addition/replacements with green.
+ for &SubstitutionHighlight { start, end } in highlight_parts {
+ // Account for tabs when highlighting (#87972).
+ let tabs: usize = line
+ .chars()
+ .take(start)
+ .map(|ch| match ch {
+ '\t' => 3,
+ _ => 0,
+ })
+ .sum();
+ buffer.set_style_range(
+ *row_num,
+ max_line_num_len + 3 + start + tabs,
+ max_line_num_len + 3 + end + tabs,
+ Style::Addition,
+ true,
+ );
+ }
+ *row_num += 1;
+ }
+}
+
+#[derive(Clone, Copy)]
+enum DisplaySuggestion {
+ Underline,
+ Diff,
+ None,
+}
+
+impl FileWithAnnotatedLines {
+ /// Preprocess all the annotations so that they are grouped by file and by line number
+ /// This helps us quickly iterate over the whole message (including secondary file spans)
+ pub fn collect_annotations(
+ emitter: &dyn Emitter,
+ args: &FluentArgs<'_>,
+ msp: &MultiSpan,
+ ) -> Vec<FileWithAnnotatedLines> {
+ fn add_annotation_to_file(
+ file_vec: &mut Vec<FileWithAnnotatedLines>,
+ file: Lrc<SourceFile>,
+ line_index: usize,
+ ann: Annotation,
+ ) {
+ for slot in file_vec.iter_mut() {
+ // Look through each of our files for the one we're adding to
+ if slot.file.name == file.name {
+ // See if we already have a line for it
+ for line_slot in &mut slot.lines {
+ if line_slot.line_index == line_index {
+ line_slot.annotations.push(ann);
+ return;
+ }
+ }
+ // We don't have a line yet, create one
+ slot.lines.push(Line { line_index, annotations: vec![ann] });
+ slot.lines.sort();
+ return;
+ }
+ }
+ // This is the first time we're seeing the file
+ file_vec.push(FileWithAnnotatedLines {
+ file,
+ lines: vec![Line { line_index, annotations: vec![ann] }],
+ multiline_depth: 0,
+ });
+ }
+
+ let mut output = vec![];
+ let mut multiline_annotations = vec![];
+
+ if let Some(ref sm) = emitter.source_map() {
+ for span_label in msp.span_labels() {
+ if span_label.span.is_dummy() {
+ continue;
+ }
+
+ let lo = sm.lookup_char_pos(span_label.span.lo());
+ let mut hi = sm.lookup_char_pos(span_label.span.hi());
+
+ // Watch out for "empty spans". If we get a span like 6..6, we
+ // want to just display a `^` at 6, so convert that to
+ // 6..7. This is degenerate input, but it's best to degrade
+ // gracefully -- and the parser likes to supply a span like
+ // that for EOF, in particular.
+
+ if lo.col_display == hi.col_display && lo.line == hi.line {
+ hi.col_display += 1;
+ }
+
+ if lo.line != hi.line {
+ let ml = MultilineAnnotation {
+ depth: 1,
+ line_start: lo.line,
+ line_end: hi.line,
+ start_col: lo.col_display,
+ end_col: hi.col_display,
+ is_primary: span_label.is_primary,
+ label: span_label
+ .label
+ .as_ref()
+ .map(|m| emitter.translate_message(m, args).to_string()),
+ overlaps_exactly: false,
+ };
+ multiline_annotations.push((lo.file, ml));
+ } else {
+ let ann = Annotation {
+ start_col: lo.col_display,
+ end_col: hi.col_display,
+ is_primary: span_label.is_primary,
+ label: span_label
+ .label
+ .as_ref()
+ .map(|m| emitter.translate_message(m, args).to_string()),
+ annotation_type: AnnotationType::Singleline,
+ };
+ add_annotation_to_file(&mut output, lo.file, lo.line, ann);
+ };
+ }
+ }
+
+ // Find overlapping multiline annotations, put them at different depths
+ multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
+ for (_, ann) in multiline_annotations.clone() {
+ for (_, a) in multiline_annotations.iter_mut() {
+ // Move all other multiline annotations overlapping with this one
+ // one level to the right.
+ if !(ann.same_span(a))
+ && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
+ {
+ a.increase_depth();
+ } else if ann.same_span(a) && &ann != a {
+ a.overlaps_exactly = true;
+ } else {
+ break;
+ }
+ }
+ }
+
+ let mut max_depth = 0; // max overlapping multiline spans
+ for (file, ann) in multiline_annotations {
+ max_depth = max(max_depth, ann.depth);
+ let mut end_ann = ann.as_end();
+ if !ann.overlaps_exactly {
+ // avoid output like
+ //
+ // | foo(
+ // | _____^
+ // | |_____|
+ // | || bar,
+ // | || );
+ // | || ^
+ // | ||______|
+ // | |______foo
+ // | baz
+ //
+ // and instead get
+ //
+ // | foo(
+ // | _____^
+ // | | bar,
+ // | | );
+ // | | ^
+ // | | |
+ // | |______foo
+ // | baz
+ add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
+ // 4 is the minimum vertical length of a multiline span when presented: two lines
+ // of code and two lines of underline. This is not true for the special case where
+ // the beginning doesn't have an underline, but the current logic seems to be
+ // working correctly.
+ let middle = min(ann.line_start + 4, ann.line_end);
+ for line in ann.line_start + 1..middle {
+ // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
+ add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
+ }
+ let line_end = ann.line_end - 1;
+ if middle < line_end {
+ add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
+ }
+ } else {
+ end_ann.annotation_type = AnnotationType::Singleline;
+ }
+ add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
+ }
+ for file_vec in output.iter_mut() {
+ file_vec.multiline_depth = max_depth;
+ }
+ output
+ }
+}
+
+// instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
+// we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
+// is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
+// This is also why we need the max number of decimal digits within a `usize`.
+fn num_decimal_digits(num: usize) -> usize {
+ #[cfg(target_pointer_width = "64")]
+ const MAX_DIGITS: usize = 20;
+
+ #[cfg(target_pointer_width = "32")]
+ const MAX_DIGITS: usize = 10;
+
+ #[cfg(target_pointer_width = "16")]
+ const MAX_DIGITS: usize = 5;
+
+ let mut lim = 10;
+ for num_digits in 1..MAX_DIGITS {
+ if num < lim {
+ return num_digits;
+ }
+ lim = lim.wrapping_mul(10);
+ }
+ MAX_DIGITS
+}
+
+// We replace some characters so the CLI output is always consistent and underlines aligned.
+const OUTPUT_REPLACEMENTS: &[(char, &str)] = &[
+ ('\t', " "), // We do our own tab replacement
+ ('\u{200D}', ""), // Replace ZWJ with nothing for consistent terminal output of grapheme clusters.
+ ('\u{202A}', ""), // The following unicode text flow control characters are inconsistently
+ ('\u{202B}', ""), // supported across CLIs and can cause confusion due to the bytes on disk
+ ('\u{202D}', ""), // not corresponding to the visible source code, so we replace them always.
+ ('\u{202E}', ""),
+ ('\u{2066}', ""),
+ ('\u{2067}', ""),
+ ('\u{2068}', ""),
+ ('\u{202C}', ""),
+ ('\u{2069}', ""),
+];
+
+fn normalize_whitespace(str: &str) -> String {
+ let mut s = str.to_string();
+ for (c, replacement) in OUTPUT_REPLACEMENTS {
+ s = s.replace(*c, replacement);
+ }
+ s
+}
+
+fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
+ buffer.puts(line, col, "| ", Style::LineNumber);
+}
+
+fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
+ draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
+}
+
+fn draw_col_separator_no_space_with_style(
+ buffer: &mut StyledBuffer,
+ line: usize,
+ col: usize,
+ style: Style,
+) {
+ buffer.putc(line, col, '|', style);
+}
+
+fn draw_range(
+ buffer: &mut StyledBuffer,
+ symbol: char,
+ line: usize,
+ col_from: usize,
+ col_to: usize,
+ style: Style,
+) {
+ for col in col_from..col_to {
+ buffer.putc(line, col, symbol, style);
+ }
+}
+
+fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
+ buffer.puts(line, col, "= ", Style::LineNumber);
+}
+
+fn draw_multiline_line(
+ buffer: &mut StyledBuffer,
+ line: usize,
+ offset: usize,
+ depth: usize,
+ style: Style,
+) {
+ buffer.putc(line, offset + depth - 1, '|', style);
+}
+
+fn num_overlap(
+ a_start: usize,
+ a_end: usize,
+ b_start: usize,
+ b_end: usize,
+ inclusive: bool,
+) -> bool {
+ let extra = if inclusive { 1 } else { 0 };
+ (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
+}
+fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
+ num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
+}
+
+fn emit_to_destination(
+ rendered_buffer: &[Vec<StyledString>],
+ lvl: &Level,
+ dst: &mut Destination,
+ short_message: bool,
+) -> io::Result<()> {
+ use crate::lock;
+
+ let mut dst = dst.writable();
+
+ // In order to prevent error message interleaving, where multiple error lines get intermixed
+ // when multiple compiler processes error simultaneously, we emit errors with additional
+ // steps.
+ //
+ // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
+ // the .flush() is called we take the buffer created from the buffered writes and write it at
+ // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
+ // scheme, this buffered approach works and maintains the styling.
+ //
+ // On Windows, styling happens through calls to a terminal API. This prevents us from using the
+ // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
+ // enough to output the full error message, then we release.
+ let _buffer_lock = lock::acquire_global_lock("rustc_errors");
+ for (pos, line) in rendered_buffer.iter().enumerate() {
+ for part in line {
+ dst.apply_style(*lvl, part.style)?;
+ write!(dst, "{}", part.text)?;
+ dst.reset()?;
+ }
+ if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
+ writeln!(dst)?;
+ }
+ }
+ dst.flush()?;
+ Ok(())
+}
+
+pub enum Destination {
+ Terminal(StandardStream),
+ Buffered(BufferWriter),
+ // The bool denotes whether we should be emitting ansi color codes or not
+ Raw(Box<(dyn Write + Send)>, bool),
+}
+
+pub enum WritableDst<'a> {
+ Terminal(&'a mut StandardStream),
+ Buffered(&'a mut BufferWriter, Buffer),
+ Raw(&'a mut (dyn Write + Send)),
+ ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
+}
+
+impl Destination {
+ fn from_stderr(color: ColorConfig) -> Destination {
+ let choice = color.to_color_choice();
+ // On Windows we'll be performing global synchronization on the entire
+ // system for emitting rustc errors, so there's no need to buffer
+ // anything.
+ //
+ // On non-Windows we rely on the atomicity of `write` to ensure errors
+ // don't get all jumbled up.
+ if cfg!(windows) {
+ Terminal(StandardStream::stderr(choice))
+ } else {
+ Buffered(BufferWriter::stderr(choice))
+ }
+ }
+
+ fn writable(&mut self) -> WritableDst<'_> {
+ match *self {
+ Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
+ Destination::Buffered(ref mut t) => {
+ let buf = t.buffer();
+ WritableDst::Buffered(t, buf)
+ }
+ Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
+ Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
+ }
+ }
+
+ fn supports_color(&self) -> bool {
+ match *self {
+ Self::Terminal(ref stream) => stream.supports_color(),
+ Self::Buffered(ref buffer) => buffer.buffer().supports_color(),
+ Self::Raw(_, supports_color) => supports_color,
+ }
+ }
+}
+
+impl<'a> WritableDst<'a> {
+ fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
+ let mut spec = ColorSpec::new();
+ match style {
+ Style::Addition => {
+ spec.set_fg(Some(Color::Green)).set_intense(true);
+ }
+ Style::Removal => {
+ spec.set_fg(Some(Color::Red)).set_intense(true);
+ }
+ Style::LineAndColumn => {}
+ Style::LineNumber => {
+ spec.set_bold(true);
+ spec.set_intense(true);
+ if cfg!(windows) {
+ spec.set_fg(Some(Color::Cyan));
+ } else {
+ spec.set_fg(Some(Color::Blue));
+ }
+ }
+ Style::Quotation => {}
+ Style::MainHeaderMsg => {
+ spec.set_bold(true);
+ if cfg!(windows) {
+ spec.set_intense(true).set_fg(Some(Color::White));
+ }
+ }
+ Style::UnderlinePrimary | Style::LabelPrimary => {
+ spec = lvl.color();
+ spec.set_bold(true);
+ }
+ Style::UnderlineSecondary | Style::LabelSecondary => {
+ spec.set_bold(true).set_intense(true);
+ if cfg!(windows) {
+ spec.set_fg(Some(Color::Cyan));
+ } else {
+ spec.set_fg(Some(Color::Blue));
+ }
+ }
+ Style::HeaderMsg | Style::NoStyle => {}
+ Style::Level(lvl) => {
+ spec = lvl.color();
+ spec.set_bold(true);
+ }
+ Style::Highlight => {
+ spec.set_bold(true);
+ }
+ }
+ self.set_color(&spec)
+ }
+
+ fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
+ match *self {
+ WritableDst::Terminal(ref mut t) => t.set_color(color),
+ WritableDst::Buffered(_, ref mut t) => t.set_color(color),
+ WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
+ WritableDst::Raw(_) => Ok(()),
+ }
+ }
+
+ fn reset(&mut self) -> io::Result<()> {
+ match *self {
+ WritableDst::Terminal(ref mut t) => t.reset(),
+ WritableDst::Buffered(_, ref mut t) => t.reset(),
+ WritableDst::ColoredRaw(ref mut t) => t.reset(),
+ WritableDst::Raw(_) => Ok(()),
+ }
+ }
+}
+
+impl<'a> Write for WritableDst<'a> {
+ fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
+ match *self {
+ WritableDst::Terminal(ref mut t) => t.write(bytes),
+ WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
+ WritableDst::Raw(ref mut w) => w.write(bytes),
+ WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
+ }
+ }
+
+ fn flush(&mut self) -> io::Result<()> {
+ match *self {
+ WritableDst::Terminal(ref mut t) => t.flush(),
+ WritableDst::Buffered(_, ref mut buf) => buf.flush(),
+ WritableDst::Raw(ref mut w) => w.flush(),
+ WritableDst::ColoredRaw(ref mut w) => w.flush(),
+ }
+ }
+}
+
+impl<'a> Drop for WritableDst<'a> {
+ fn drop(&mut self) {
+ if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
+ drop(dst.print(buf));
+ }
+ }
+}
+
+/// Whether the original and suggested code are visually similar enough to warrant extra wording.
+pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
+ // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
+ let found = match sm.span_to_snippet(sp) {
+ Ok(snippet) => snippet,
+ Err(e) => {
+ warn!(error = ?e, "Invalid span {:?}", sp);
+ return false;
+ }
+ };
+ let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
+ // All the chars that differ in capitalization are confusable (above):
+ let confusable = iter::zip(found.chars(), suggested.chars())
+ .filter(|(f, s)| f != s)
+ .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
+ confusable && found.to_lowercase() == suggested.to_lowercase()
+ // FIXME: We sometimes suggest the same thing we already have, which is a
+ // bug, but be defensive against that here.
+ && found != suggested
+}
diff --git a/compiler/rustc_errors/src/json.rs b/compiler/rustc_errors/src/json.rs
new file mode 100644
index 000000000..b8cd334b4
--- /dev/null
+++ b/compiler/rustc_errors/src/json.rs
@@ -0,0 +1,561 @@
+//! A JSON emitter for errors.
+//!
+//! This works by converting errors to a simplified structural format (see the
+//! structs at the start of the file) and then serializing them. These should
+//! contain as much information about the error as possible.
+//!
+//! The format of the JSON output should be considered *unstable*. For now the
+//! structs at the end of this file (Diagnostic*) specify the error format.
+
+// FIXME: spec the JSON output properly.
+
+use rustc_span::source_map::{FilePathMapping, SourceMap};
+
+use crate::emitter::{Emitter, HumanReadableErrorType};
+use crate::registry::Registry;
+use crate::DiagnosticId;
+use crate::{
+ CodeSuggestion, FluentBundle, LazyFallbackBundle, MultiSpan, SpanLabel, SubDiagnostic,
+};
+use rustc_lint_defs::Applicability;
+
+use rustc_data_structures::sync::Lrc;
+use rustc_error_messages::FluentArgs;
+use rustc_span::hygiene::ExpnData;
+use rustc_span::Span;
+use std::io::{self, Write};
+use std::path::Path;
+use std::sync::{Arc, Mutex};
+use std::vec;
+
+use serde::Serialize;
+
+#[cfg(test)]
+mod tests;
+
+pub struct JsonEmitter {
+ dst: Box<dyn Write + Send>,
+ registry: Option<Registry>,
+ sm: Lrc<SourceMap>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ pretty: bool,
+ ui_testing: bool,
+ json_rendered: HumanReadableErrorType,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+}
+
+impl JsonEmitter {
+ pub fn stderr(
+ registry: Option<Registry>,
+ source_map: Lrc<SourceMap>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ pretty: bool,
+ json_rendered: HumanReadableErrorType,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> JsonEmitter {
+ JsonEmitter {
+ dst: Box::new(io::BufWriter::new(io::stderr())),
+ registry,
+ sm: source_map,
+ fluent_bundle,
+ fallback_bundle,
+ pretty,
+ ui_testing: false,
+ json_rendered,
+ diagnostic_width,
+ macro_backtrace,
+ }
+ }
+
+ pub fn basic(
+ pretty: bool,
+ json_rendered: HumanReadableErrorType,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> JsonEmitter {
+ let file_path_mapping = FilePathMapping::empty();
+ JsonEmitter::stderr(
+ None,
+ Lrc::new(SourceMap::new(file_path_mapping)),
+ fluent_bundle,
+ fallback_bundle,
+ pretty,
+ json_rendered,
+ diagnostic_width,
+ macro_backtrace,
+ )
+ }
+
+ pub fn new(
+ dst: Box<dyn Write + Send>,
+ registry: Option<Registry>,
+ source_map: Lrc<SourceMap>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ pretty: bool,
+ json_rendered: HumanReadableErrorType,
+ diagnostic_width: Option<usize>,
+ macro_backtrace: bool,
+ ) -> JsonEmitter {
+ JsonEmitter {
+ dst,
+ registry,
+ sm: source_map,
+ fluent_bundle,
+ fallback_bundle,
+ pretty,
+ ui_testing: false,
+ json_rendered,
+ diagnostic_width,
+ macro_backtrace,
+ }
+ }
+
+ pub fn ui_testing(self, ui_testing: bool) -> Self {
+ Self { ui_testing, ..self }
+ }
+}
+
+impl Emitter for JsonEmitter {
+ fn emit_diagnostic(&mut self, diag: &crate::Diagnostic) {
+ let data = Diagnostic::from_errors_diagnostic(diag, self);
+ let result = if self.pretty {
+ writeln!(&mut self.dst, "{}", serde_json::to_string_pretty(&data).unwrap())
+ } else {
+ writeln!(&mut self.dst, "{}", serde_json::to_string(&data).unwrap())
+ }
+ .and_then(|_| self.dst.flush());
+ if let Err(e) = result {
+ panic!("failed to print diagnostics: {:?}", e);
+ }
+ }
+
+ fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) {
+ let data = ArtifactNotification { artifact: path, emit: artifact_type };
+ let result = if self.pretty {
+ writeln!(&mut self.dst, "{}", serde_json::to_string_pretty(&data).unwrap())
+ } else {
+ writeln!(&mut self.dst, "{}", serde_json::to_string(&data).unwrap())
+ }
+ .and_then(|_| self.dst.flush());
+ if let Err(e) = result {
+ panic!("failed to print notification: {:?}", e);
+ }
+ }
+
+ fn emit_future_breakage_report(&mut self, diags: Vec<crate::Diagnostic>) {
+ let data: Vec<FutureBreakageItem> = diags
+ .into_iter()
+ .map(|mut diag| {
+ if diag.level == crate::Level::Allow {
+ diag.level = crate::Level::Warning(None);
+ }
+ FutureBreakageItem { diagnostic: Diagnostic::from_errors_diagnostic(&diag, self) }
+ })
+ .collect();
+ let report = FutureIncompatReport { future_incompat_report: data };
+ let result = if self.pretty {
+ writeln!(&mut self.dst, "{}", serde_json::to_string_pretty(&report).unwrap())
+ } else {
+ writeln!(&mut self.dst, "{}", serde_json::to_string(&report).unwrap())
+ }
+ .and_then(|_| self.dst.flush());
+ if let Err(e) = result {
+ panic!("failed to print future breakage report: {:?}", e);
+ }
+ }
+
+ fn emit_unused_externs(&mut self, lint_level: rustc_lint_defs::Level, unused_externs: &[&str]) {
+ let lint_level = lint_level.as_str();
+ let data = UnusedExterns { lint_level, unused_extern_names: unused_externs };
+ let result = if self.pretty {
+ writeln!(&mut self.dst, "{}", serde_json::to_string_pretty(&data).unwrap())
+ } else {
+ writeln!(&mut self.dst, "{}", serde_json::to_string(&data).unwrap())
+ }
+ .and_then(|_| self.dst.flush());
+ if let Err(e) = result {
+ panic!("failed to print unused externs: {:?}", e);
+ }
+ }
+
+ fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+ Some(&self.sm)
+ }
+
+ fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+ self.fluent_bundle.as_ref()
+ }
+
+ fn fallback_fluent_bundle(&self) -> &FluentBundle {
+ &**self.fallback_bundle
+ }
+
+ fn should_show_explain(&self) -> bool {
+ !matches!(self.json_rendered, HumanReadableErrorType::Short(_))
+ }
+}
+
+// The following data types are provided just for serialisation.
+
+#[derive(Serialize)]
+struct Diagnostic {
+ /// The primary error message.
+ message: String,
+ code: Option<DiagnosticCode>,
+ /// "error: internal compiler error", "error", "warning", "note", "help".
+ level: &'static str,
+ spans: Vec<DiagnosticSpan>,
+ /// Associated diagnostic messages.
+ children: Vec<Diagnostic>,
+ /// The message as rustc would render it.
+ rendered: Option<String>,
+}
+
+#[derive(Serialize)]
+struct DiagnosticSpan {
+ file_name: String,
+ byte_start: u32,
+ byte_end: u32,
+ /// 1-based.
+ line_start: usize,
+ line_end: usize,
+ /// 1-based, character offset.
+ column_start: usize,
+ column_end: usize,
+ /// Is this a "primary" span -- meaning the point, or one of the points,
+ /// where the error occurred?
+ is_primary: bool,
+ /// Source text from the start of line_start to the end of line_end.
+ text: Vec<DiagnosticSpanLine>,
+ /// Label that should be placed at this location (if any)
+ label: Option<String>,
+ /// If we are suggesting a replacement, this will contain text
+ /// that should be sliced in atop this span.
+ suggested_replacement: Option<String>,
+ /// If the suggestion is approximate
+ suggestion_applicability: Option<Applicability>,
+ /// Macro invocations that created the code at this span, if any.
+ expansion: Option<Box<DiagnosticSpanMacroExpansion>>,
+}
+
+#[derive(Serialize)]
+struct DiagnosticSpanLine {
+ text: String,
+
+ /// 1-based, character offset in self.text.
+ highlight_start: usize,
+
+ highlight_end: usize,
+}
+
+#[derive(Serialize)]
+struct DiagnosticSpanMacroExpansion {
+ /// span where macro was applied to generate this code; note that
+ /// this may itself derive from a macro (if
+ /// `span.expansion.is_some()`)
+ span: DiagnosticSpan,
+
+ /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]")
+ macro_decl_name: String,
+
+ /// span where macro was defined (if known)
+ def_site_span: DiagnosticSpan,
+}
+
+#[derive(Serialize)]
+struct DiagnosticCode {
+ /// The code itself.
+ code: String,
+ /// An explanation for the code.
+ explanation: Option<&'static str>,
+}
+
+#[derive(Serialize)]
+struct ArtifactNotification<'a> {
+ /// The path of the artifact.
+ artifact: &'a Path,
+ /// What kind of artifact we're emitting.
+ emit: &'a str,
+}
+
+#[derive(Serialize)]
+struct FutureBreakageItem {
+ diagnostic: Diagnostic,
+}
+
+#[derive(Serialize)]
+struct FutureIncompatReport {
+ future_incompat_report: Vec<FutureBreakageItem>,
+}
+
+// NOTE: Keep this in sync with the equivalent structs in rustdoc's
+// doctest component (as well as cargo).
+// We could unify this struct the one in rustdoc but they have different
+// ownership semantics, so doing so would create wasteful allocations.
+#[derive(Serialize)]
+struct UnusedExterns<'a, 'b, 'c> {
+ /// The severity level of the unused dependencies lint
+ lint_level: &'a str,
+ /// List of unused externs by their names.
+ unused_extern_names: &'b [&'c str],
+}
+
+impl Diagnostic {
+ fn from_errors_diagnostic(diag: &crate::Diagnostic, je: &JsonEmitter) -> Diagnostic {
+ let args = je.to_fluent_args(diag.args());
+ let sugg = diag.suggestions.iter().flatten().map(|sugg| {
+ let translated_message = je.translate_message(&sugg.msg, &args);
+ Diagnostic {
+ message: translated_message.to_string(),
+ code: None,
+ level: "help",
+ spans: DiagnosticSpan::from_suggestion(sugg, &args, je),
+ children: vec![],
+ rendered: None,
+ }
+ });
+
+ // generate regular command line output and store it in the json
+
+ // A threadsafe buffer for writing.
+ #[derive(Default, Clone)]
+ struct BufWriter(Arc<Mutex<Vec<u8>>>);
+
+ impl Write for BufWriter {
+ fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+ self.0.lock().unwrap().write(buf)
+ }
+ fn flush(&mut self) -> io::Result<()> {
+ self.0.lock().unwrap().flush()
+ }
+ }
+ let buf = BufWriter::default();
+ let output = buf.clone();
+ je.json_rendered
+ .new_emitter(
+ Box::new(buf),
+ Some(je.sm.clone()),
+ je.fluent_bundle.clone(),
+ je.fallback_bundle.clone(),
+ false,
+ je.diagnostic_width,
+ je.macro_backtrace,
+ )
+ .ui_testing(je.ui_testing)
+ .emit_diagnostic(diag);
+ let output = Arc::try_unwrap(output.0).unwrap().into_inner().unwrap();
+ let output = String::from_utf8(output).unwrap();
+
+ let translated_message = je.translate_messages(&diag.message, &args);
+ Diagnostic {
+ message: translated_message.to_string(),
+ code: DiagnosticCode::map_opt_string(diag.code.clone(), je),
+ level: diag.level.to_str(),
+ spans: DiagnosticSpan::from_multispan(&diag.span, &args, je),
+ children: diag
+ .children
+ .iter()
+ .map(|c| Diagnostic::from_sub_diagnostic(c, &args, je))
+ .chain(sugg)
+ .collect(),
+ rendered: Some(output),
+ }
+ }
+
+ fn from_sub_diagnostic(
+ diag: &SubDiagnostic,
+ args: &FluentArgs<'_>,
+ je: &JsonEmitter,
+ ) -> Diagnostic {
+ let translated_message = je.translate_messages(&diag.message, args);
+ Diagnostic {
+ message: translated_message.to_string(),
+ code: None,
+ level: diag.level.to_str(),
+ spans: diag
+ .render_span
+ .as_ref()
+ .map(|sp| DiagnosticSpan::from_multispan(sp, args, je))
+ .unwrap_or_else(|| DiagnosticSpan::from_multispan(&diag.span, args, je)),
+ children: vec![],
+ rendered: None,
+ }
+ }
+}
+
+impl DiagnosticSpan {
+ fn from_span_label(
+ span: SpanLabel,
+ suggestion: Option<(&String, Applicability)>,
+ args: &FluentArgs<'_>,
+ je: &JsonEmitter,
+ ) -> DiagnosticSpan {
+ Self::from_span_etc(
+ span.span,
+ span.is_primary,
+ span.label.as_ref().map(|m| je.translate_message(m, args)).map(|m| m.to_string()),
+ suggestion,
+ je,
+ )
+ }
+
+ fn from_span_etc(
+ span: Span,
+ is_primary: bool,
+ label: Option<String>,
+ suggestion: Option<(&String, Applicability)>,
+ je: &JsonEmitter,
+ ) -> DiagnosticSpan {
+ // obtain the full backtrace from the `macro_backtrace`
+ // helper; in some ways, it'd be better to expand the
+ // backtrace ourselves, but the `macro_backtrace` helper makes
+ // some decision, such as dropping some frames, and I don't
+ // want to duplicate that logic here.
+ let backtrace = span.macro_backtrace();
+ DiagnosticSpan::from_span_full(span, is_primary, label, suggestion, backtrace, je)
+ }
+
+ fn from_span_full(
+ span: Span,
+ is_primary: bool,
+ label: Option<String>,
+ suggestion: Option<(&String, Applicability)>,
+ mut backtrace: impl Iterator<Item = ExpnData>,
+ je: &JsonEmitter,
+ ) -> DiagnosticSpan {
+ let start = je.sm.lookup_char_pos(span.lo());
+ let end = je.sm.lookup_char_pos(span.hi());
+ let backtrace_step = backtrace.next().map(|bt| {
+ let call_site = Self::from_span_full(bt.call_site, false, None, None, backtrace, je);
+ let def_site_span = Self::from_span_full(
+ je.sm.guess_head_span(bt.def_site),
+ false,
+ None,
+ None,
+ [].into_iter(),
+ je,
+ );
+ Box::new(DiagnosticSpanMacroExpansion {
+ span: call_site,
+ macro_decl_name: bt.kind.descr(),
+ def_site_span,
+ })
+ });
+
+ DiagnosticSpan {
+ file_name: je.sm.filename_for_diagnostics(&start.file.name).to_string(),
+ byte_start: start.file.original_relative_byte_pos(span.lo()).0,
+ byte_end: start.file.original_relative_byte_pos(span.hi()).0,
+ line_start: start.line,
+ line_end: end.line,
+ column_start: start.col.0 + 1,
+ column_end: end.col.0 + 1,
+ is_primary,
+ text: DiagnosticSpanLine::from_span(span, je),
+ suggested_replacement: suggestion.map(|x| x.0.clone()),
+ suggestion_applicability: suggestion.map(|x| x.1),
+ expansion: backtrace_step,
+ label,
+ }
+ }
+
+ fn from_multispan(
+ msp: &MultiSpan,
+ args: &FluentArgs<'_>,
+ je: &JsonEmitter,
+ ) -> Vec<DiagnosticSpan> {
+ msp.span_labels()
+ .into_iter()
+ .map(|span_str| Self::from_span_label(span_str, None, args, je))
+ .collect()
+ }
+
+ fn from_suggestion(
+ suggestion: &CodeSuggestion,
+ args: &FluentArgs<'_>,
+ je: &JsonEmitter,
+ ) -> Vec<DiagnosticSpan> {
+ suggestion
+ .substitutions
+ .iter()
+ .flat_map(|substitution| {
+ substitution.parts.iter().map(move |suggestion_inner| {
+ let span_label =
+ SpanLabel { span: suggestion_inner.span, is_primary: true, label: None };
+ DiagnosticSpan::from_span_label(
+ span_label,
+ Some((&suggestion_inner.snippet, suggestion.applicability)),
+ args,
+ je,
+ )
+ })
+ })
+ .collect()
+ }
+}
+
+impl DiagnosticSpanLine {
+ fn line_from_source_file(
+ sf: &rustc_span::SourceFile,
+ index: usize,
+ h_start: usize,
+ h_end: usize,
+ ) -> DiagnosticSpanLine {
+ DiagnosticSpanLine {
+ text: sf.get_line(index).map_or_else(String::new, |l| l.into_owned()),
+ highlight_start: h_start,
+ highlight_end: h_end,
+ }
+ }
+
+ /// Creates a list of DiagnosticSpanLines from span - each line with any part
+ /// of `span` gets a DiagnosticSpanLine, with the highlight indicating the
+ /// `span` within the line.
+ fn from_span(span: Span, je: &JsonEmitter) -> Vec<DiagnosticSpanLine> {
+ je.sm
+ .span_to_lines(span)
+ .map(|lines| {
+ // We can't get any lines if the source is unavailable.
+ if !je.sm.ensure_source_file_source_present(lines.file.clone()) {
+ return vec![];
+ }
+
+ let sf = &*lines.file;
+ lines
+ .lines
+ .iter()
+ .map(|line| {
+ DiagnosticSpanLine::line_from_source_file(
+ sf,
+ line.line_index,
+ line.start_col.0 + 1,
+ line.end_col.0 + 1,
+ )
+ })
+ .collect()
+ })
+ .unwrap_or_else(|_| vec![])
+ }
+}
+
+impl DiagnosticCode {
+ fn map_opt_string(s: Option<DiagnosticId>, je: &JsonEmitter) -> Option<DiagnosticCode> {
+ s.map(|s| {
+ let s = match s {
+ DiagnosticId::Error(s) => s,
+ DiagnosticId::Lint { name, .. } => name,
+ };
+ let je_result =
+ je.registry.as_ref().map(|registry| registry.try_find_description(&s)).unwrap();
+
+ DiagnosticCode { code: s, explanation: je_result.unwrap_or(None) }
+ })
+ }
+}
diff --git a/compiler/rustc_errors/src/json/tests.rs b/compiler/rustc_errors/src/json/tests.rs
new file mode 100644
index 000000000..d940d14e1
--- /dev/null
+++ b/compiler/rustc_errors/src/json/tests.rs
@@ -0,0 +1,204 @@
+use super::*;
+
+use crate::json::JsonEmitter;
+use rustc_span::source_map::{FilePathMapping, SourceMap};
+
+use crate::emitter::{ColorConfig, HumanReadableErrorType};
+use crate::Handler;
+use rustc_span::{BytePos, Span};
+
+use std::str;
+
+use serde::Deserialize;
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+struct TestData {
+ spans: Vec<SpanTestData>,
+}
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+struct SpanTestData {
+ pub byte_start: u32,
+ pub byte_end: u32,
+ pub line_start: u32,
+ pub column_start: u32,
+ pub line_end: u32,
+ pub column_end: u32,
+}
+
+struct Shared<T> {
+ data: Arc<Mutex<T>>,
+}
+
+impl<T: Write> Write for Shared<T> {
+ fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+ self.data.lock().unwrap().write(buf)
+ }
+
+ fn flush(&mut self) -> io::Result<()> {
+ self.data.lock().unwrap().flush()
+ }
+}
+
+/// Test the span yields correct positions in JSON.
+fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
+ rustc_span::create_default_session_globals_then(|| {
+ let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+ sm.new_source_file(Path::new("test.rs").to_owned().into(), code.to_owned());
+ let fallback_bundle =
+ crate::fallback_fluent_bundle(rustc_error_messages::DEFAULT_LOCALE_RESOURCES, false);
+
+ let output = Arc::new(Mutex::new(Vec::new()));
+ let je = JsonEmitter::new(
+ Box::new(Shared { data: output.clone() }),
+ None,
+ sm,
+ None,
+ fallback_bundle,
+ true,
+ HumanReadableErrorType::Short(ColorConfig::Never),
+ None,
+ false,
+ );
+
+ let span = Span::with_root_ctxt(BytePos(span.0), BytePos(span.1));
+ let handler = Handler::with_emitter(true, None, Box::new(je));
+ handler.span_err(span, "foo");
+
+ let bytes = output.lock().unwrap();
+ let actual_output = str::from_utf8(&bytes).unwrap();
+ let actual_output: TestData = serde_json::from_str(actual_output).unwrap();
+ let spans = actual_output.spans;
+ assert_eq!(spans.len(), 1);
+
+ assert_eq!(expected_output, spans[0])
+ })
+}
+
+#[test]
+fn empty() {
+ test_positions(
+ " ",
+ (0, 1),
+ SpanTestData {
+ byte_start: 0,
+ byte_end: 1,
+ line_start: 1,
+ column_start: 1,
+ line_end: 1,
+ column_end: 2,
+ },
+ )
+}
+
+#[test]
+fn bom() {
+ test_positions(
+ "\u{feff} ",
+ (0, 1),
+ SpanTestData {
+ byte_start: 3,
+ byte_end: 4,
+ line_start: 1,
+ column_start: 1,
+ line_end: 1,
+ column_end: 2,
+ },
+ )
+}
+
+#[test]
+fn lf_newlines() {
+ test_positions(
+ "\nmod foo;\nmod bar;\n",
+ (5, 12),
+ SpanTestData {
+ byte_start: 5,
+ byte_end: 12,
+ line_start: 2,
+ column_start: 5,
+ line_end: 3,
+ column_end: 3,
+ },
+ )
+}
+
+#[test]
+fn crlf_newlines() {
+ test_positions(
+ "\r\nmod foo;\r\nmod bar;\r\n",
+ (5, 12),
+ SpanTestData {
+ byte_start: 6,
+ byte_end: 14,
+ line_start: 2,
+ column_start: 5,
+ line_end: 3,
+ column_end: 3,
+ },
+ )
+}
+
+#[test]
+fn crlf_newlines_with_bom() {
+ test_positions(
+ "\u{feff}\r\nmod foo;\r\nmod bar;\r\n",
+ (5, 12),
+ SpanTestData {
+ byte_start: 9,
+ byte_end: 17,
+ line_start: 2,
+ column_start: 5,
+ line_end: 3,
+ column_end: 3,
+ },
+ )
+}
+
+#[test]
+fn span_before_crlf() {
+ test_positions(
+ "foo\r\nbar",
+ (2, 3),
+ SpanTestData {
+ byte_start: 2,
+ byte_end: 3,
+ line_start: 1,
+ column_start: 3,
+ line_end: 1,
+ column_end: 4,
+ },
+ )
+}
+
+#[test]
+fn span_on_crlf() {
+ test_positions(
+ "foo\r\nbar",
+ (3, 4),
+ SpanTestData {
+ byte_start: 3,
+ byte_end: 5,
+ line_start: 1,
+ column_start: 4,
+ line_end: 2,
+ column_end: 1,
+ },
+ )
+}
+
+#[test]
+fn span_after_crlf() {
+ test_positions(
+ "foo\r\nbar",
+ (4, 5),
+ SpanTestData {
+ byte_start: 5,
+ byte_end: 6,
+ line_start: 2,
+ column_start: 1,
+ line_end: 2,
+ column_end: 2,
+ },
+ )
+}
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
new file mode 100644
index 000000000..2409c0b5a
--- /dev/null
+++ b/compiler/rustc_errors/src/lib.rs
@@ -0,0 +1,1589 @@
+//! Diagnostics creation and emission for `rustc`.
+//!
+//! This module contains the code for creating and emitting diagnostics.
+
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(drain_filter)]
+#![feature(backtrace)]
+#![feature(if_let_guard)]
+#![feature(let_chains)]
+#![feature(let_else)]
+#![feature(never_type)]
+#![feature(adt_const_params)]
+#![feature(rustc_attrs)]
+#![allow(incomplete_features)]
+#![allow(rustc::potential_query_instability)]
+
+#[macro_use]
+extern crate rustc_macros;
+
+#[macro_use]
+extern crate tracing;
+
+pub use emitter::ColorConfig;
+
+use rustc_lint_defs::LintExpectationId;
+use Level::*;
+
+use emitter::{is_case_difference, Emitter, EmitterWriter};
+use registry::Registry;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::stable_hasher::StableHasher;
+use rustc_data_structures::sync::{self, Lock, Lrc};
+use rustc_data_structures::AtomicRef;
+pub use rustc_error_messages::{
+ fallback_fluent_bundle, fluent, fluent_bundle, DiagnosticMessage, FluentBundle,
+ LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagnosticMessage,
+ DEFAULT_LOCALE_RESOURCES,
+};
+pub use rustc_lint_defs::{pluralize, Applicability};
+use rustc_span::source_map::SourceMap;
+use rustc_span::HashStableContext;
+use rustc_span::{Loc, Span};
+
+use std::borrow::Cow;
+use std::hash::Hash;
+use std::num::NonZeroUsize;
+use std::panic;
+use std::path::Path;
+use std::{error, fmt};
+
+use termcolor::{Color, ColorSpec};
+
+pub mod annotate_snippet_emitter_writer;
+mod diagnostic;
+mod diagnostic_builder;
+pub mod emitter;
+pub mod json;
+mod lock;
+pub mod registry;
+mod snippet;
+mod styled_buffer;
+
+pub use snippet::Style;
+
+pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a, ErrorGuaranteed>>;
+
+// `PResult` is used a lot. Make sure it doesn't unintentionally get bigger.
+// (See also the comment on `DiagnosticBuilder`'s `diagnostic` field.)
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
+rustc_data_structures::static_assert_size!(PResult<'_, ()>, 16);
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
+rustc_data_structures::static_assert_size!(PResult<'_, bool>, 24);
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, Encodable, Decodable)]
+pub enum SuggestionStyle {
+ /// Hide the suggested code when displaying this suggestion inline.
+ HideCodeInline,
+ /// Always hide the suggested code but display the message.
+ HideCodeAlways,
+ /// Do not display this suggestion in the cli output, it is only meant for tools.
+ CompletelyHidden,
+ /// Always show the suggested code.
+ /// This will *not* show the code if the suggestion is inline *and* the suggested code is
+ /// empty.
+ ShowCode,
+ /// Always show the suggested code independently.
+ ShowAlways,
+}
+
+impl SuggestionStyle {
+ fn hide_inline(&self) -> bool {
+ !matches!(*self, SuggestionStyle::ShowCode)
+ }
+}
+
+#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
+pub struct CodeSuggestion {
+ /// Each substitute can have multiple variants due to multiple
+ /// applicable suggestions
+ ///
+ /// `foo.bar` might be replaced with `a.b` or `x.y` by replacing
+ /// `foo` and `bar` on their own:
+ ///
+ /// ```ignore (illustrative)
+ /// vec![
+ /// Substitution { parts: vec![(0..3, "a"), (4..7, "b")] },
+ /// Substitution { parts: vec![(0..3, "x"), (4..7, "y")] },
+ /// ]
+ /// ```
+ ///
+ /// or by replacing the entire span:
+ ///
+ /// ```ignore (illustrative)
+ /// vec![
+ /// Substitution { parts: vec![(0..7, "a.b")] },
+ /// Substitution { parts: vec![(0..7, "x.y")] },
+ /// ]
+ /// ```
+ pub substitutions: Vec<Substitution>,
+ pub msg: DiagnosticMessage,
+ /// Visual representation of this suggestion.
+ pub style: SuggestionStyle,
+ /// Whether or not the suggestion is approximate
+ ///
+ /// Sometimes we may show suggestions with placeholders,
+ /// which are useful for users but not useful for
+ /// tools like rustfix
+ pub applicability: Applicability,
+}
+
+#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
+/// See the docs on `CodeSuggestion::substitutions`
+pub struct Substitution {
+ pub parts: Vec<SubstitutionPart>,
+}
+
+#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
+pub struct SubstitutionPart {
+ pub span: Span,
+ pub snippet: String,
+}
+
+/// Used to translate between `Span`s and byte positions within a single output line in highlighted
+/// code of structured suggestions.
+#[derive(Debug, Clone, Copy)]
+pub struct SubstitutionHighlight {
+ start: usize,
+ end: usize,
+}
+
+impl SubstitutionPart {
+ pub fn is_addition(&self, sm: &SourceMap) -> bool {
+ !self.snippet.is_empty()
+ && sm
+ .span_to_snippet(self.span)
+ .map_or(self.span.is_empty(), |snippet| snippet.trim().is_empty())
+ }
+
+ pub fn is_deletion(&self) -> bool {
+ self.snippet.trim().is_empty()
+ }
+
+ pub fn is_replacement(&self, sm: &SourceMap) -> bool {
+ !self.snippet.is_empty()
+ && sm
+ .span_to_snippet(self.span)
+ .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
+ }
+}
+
+impl CodeSuggestion {
+ /// Returns the assembled code suggestions, whether they should be shown with an underline
+ /// and whether the substitution only differs in capitalization.
+ pub fn splice_lines(
+ &self,
+ sm: &SourceMap,
+ ) -> Vec<(String, Vec<SubstitutionPart>, Vec<Vec<SubstitutionHighlight>>, bool)> {
+ // For the `Vec<Vec<SubstitutionHighlight>>` value, the first level of the vector
+ // corresponds to the output snippet's lines, while the second level corresponds to the
+ // substrings within that line that should be highlighted.
+
+ use rustc_span::{CharPos, Pos};
+
+ /// Append to a buffer the remainder of the line of existing source code, and return the
+ /// count of lines that have been added for accurate highlighting.
+ fn push_trailing(
+ buf: &mut String,
+ line_opt: Option<&Cow<'_, str>>,
+ lo: &Loc,
+ hi_opt: Option<&Loc>,
+ ) -> usize {
+ let mut line_count = 0;
+ let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
+ if let Some(line) = line_opt {
+ if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) {
+ let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi));
+ match hi_opt {
+ Some(hi) if hi > lo => {
+ line_count = line[lo..hi].matches('\n').count();
+ buf.push_str(&line[lo..hi])
+ }
+ Some(_) => (),
+ None => {
+ line_count = line[lo..].matches('\n').count();
+ buf.push_str(&line[lo..])
+ }
+ }
+ }
+ if hi_opt.is_none() {
+ buf.push('\n');
+ }
+ }
+ line_count
+ }
+
+ assert!(!self.substitutions.is_empty());
+
+ self.substitutions
+ .iter()
+ .filter(|subst| {
+ // Suggestions coming from macros can have malformed spans. This is a heavy
+ // handed approach to avoid ICEs by ignoring the suggestion outright.
+ let invalid = subst.parts.iter().any(|item| sm.is_valid_span(item.span).is_err());
+ if invalid {
+ debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
+ }
+ !invalid
+ })
+ .cloned()
+ .filter_map(|mut substitution| {
+ // Assumption: all spans are in the same file, and all spans
+ // are disjoint. Sort in ascending order.
+ substitution.parts.sort_by_key(|part| part.span.lo());
+
+ // Find the bounding span.
+ let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?;
+ let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?;
+ let bounding_span = Span::with_root_ctxt(lo, hi);
+ // The different spans might belong to different contexts, if so ignore suggestion.
+ let lines = sm.span_to_lines(bounding_span).ok()?;
+ assert!(!lines.lines.is_empty() || bounding_span.is_dummy());
+
+ // We can't splice anything if the source is unavailable.
+ if !sm.ensure_source_file_source_present(lines.file.clone()) {
+ return None;
+ }
+
+ let mut highlights = vec![];
+ // To build up the result, we do this for each span:
+ // - push the line segment trailing the previous span
+ // (at the beginning a "phantom" span pointing at the start of the line)
+ // - push lines between the previous and current span (if any)
+ // - if the previous and current span are not on the same line
+ // push the line segment leading up to the current span
+ // - splice in the span substitution
+ //
+ // Finally push the trailing line segment of the last span
+ let sf = &lines.file;
+ let mut prev_hi = sm.lookup_char_pos(bounding_span.lo());
+ prev_hi.col = CharPos::from_usize(0);
+ let mut prev_line =
+ lines.lines.get(0).and_then(|line0| sf.get_line(line0.line_index));
+ let mut buf = String::new();
+
+ let mut line_highlight = vec![];
+ // We need to keep track of the difference between the existing code and the added
+ // or deleted code in order to point at the correct column *after* substitution.
+ let mut acc = 0;
+ for part in &substitution.parts {
+ let cur_lo = sm.lookup_char_pos(part.span.lo());
+ if prev_hi.line == cur_lo.line {
+ let mut count =
+ push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
+ while count > 0 {
+ highlights.push(std::mem::take(&mut line_highlight));
+ acc = 0;
+ count -= 1;
+ }
+ } else {
+ acc = 0;
+ highlights.push(std::mem::take(&mut line_highlight));
+ let mut count = push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
+ while count > 0 {
+ highlights.push(std::mem::take(&mut line_highlight));
+ count -= 1;
+ }
+ // push lines between the previous and current span (if any)
+ for idx in prev_hi.line..(cur_lo.line - 1) {
+ if let Some(line) = sf.get_line(idx) {
+ buf.push_str(line.as_ref());
+ buf.push('\n');
+ highlights.push(std::mem::take(&mut line_highlight));
+ }
+ }
+ if let Some(cur_line) = sf.get_line(cur_lo.line - 1) {
+ let end = match cur_line.char_indices().nth(cur_lo.col.to_usize()) {
+ Some((i, _)) => i,
+ None => cur_line.len(),
+ };
+ buf.push_str(&cur_line[..end]);
+ }
+ }
+ // Add a whole line highlight per line in the snippet.
+ let len: isize = part
+ .snippet
+ .split('\n')
+ .next()
+ .unwrap_or(&part.snippet)
+ .chars()
+ .map(|c| match c {
+ '\t' => 4,
+ _ => 1,
+ })
+ .sum();
+ line_highlight.push(SubstitutionHighlight {
+ start: (cur_lo.col.0 as isize + acc) as usize,
+ end: (cur_lo.col.0 as isize + acc + len) as usize,
+ });
+ buf.push_str(&part.snippet);
+ let cur_hi = sm.lookup_char_pos(part.span.hi());
+ if prev_hi.line == cur_lo.line && cur_hi.line == cur_lo.line {
+ // Account for the difference between the width of the current code and the
+ // snippet being suggested, so that the *later* suggestions are correctly
+ // aligned on the screen.
+ acc += len as isize - (cur_hi.col.0 - cur_lo.col.0) as isize;
+ }
+ prev_hi = cur_hi;
+ prev_line = sf.get_line(prev_hi.line - 1);
+ for line in part.snippet.split('\n').skip(1) {
+ acc = 0;
+ highlights.push(std::mem::take(&mut line_highlight));
+ let end: usize = line
+ .chars()
+ .map(|c| match c {
+ '\t' => 4,
+ _ => 1,
+ })
+ .sum();
+ line_highlight.push(SubstitutionHighlight { start: 0, end });
+ }
+ }
+ highlights.push(std::mem::take(&mut line_highlight));
+ let only_capitalization = is_case_difference(sm, &buf, bounding_span);
+ // if the replacement already ends with a newline, don't print the next line
+ if !buf.ends_with('\n') {
+ push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
+ }
+ // remove trailing newlines
+ while buf.ends_with('\n') {
+ buf.pop();
+ }
+ Some((buf, substitution.parts, highlights, only_capitalization))
+ })
+ .collect()
+ }
+}
+
+pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
+
+/// Signifies that the compiler died with an explicit call to `.bug`
+/// or `.span_bug` rather than a failed assertion, etc.
+#[derive(Copy, Clone, Debug)]
+pub struct ExplicitBug;
+
+impl fmt::Display for ExplicitBug {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "parser internal bug")
+ }
+}
+
+impl error::Error for ExplicitBug {}
+
+pub use diagnostic::{
+ AddSubdiagnostic, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgFromDisplay,
+ DiagnosticArgValue, DiagnosticId, DiagnosticStyledString, IntoDiagnosticArg, SubDiagnostic,
+};
+pub use diagnostic_builder::{DiagnosticBuilder, EmissionGuarantee, LintDiagnosticBuilder};
+use std::backtrace::Backtrace;
+
+/// A handler deals with errors and other compiler output.
+/// Certain errors (fatal, bug, unimpl) may cause immediate exit,
+/// others log errors for later reporting.
+pub struct Handler {
+ flags: HandlerFlags,
+ inner: Lock<HandlerInner>,
+}
+
+/// This inner struct exists to keep it all behind a single lock;
+/// this is done to prevent possible deadlocks in a multi-threaded compiler,
+/// as well as inconsistent state observation.
+struct HandlerInner {
+ flags: HandlerFlags,
+ /// The number of lint errors that have been emitted.
+ lint_err_count: usize,
+ /// The number of errors that have been emitted, including duplicates.
+ ///
+ /// This is not necessarily the count that's reported to the user once
+ /// compilation ends.
+ err_count: usize,
+ warn_count: usize,
+ deduplicated_err_count: usize,
+ emitter: Box<dyn Emitter + sync::Send>,
+ delayed_span_bugs: Vec<Diagnostic>,
+ delayed_good_path_bugs: Vec<DelayedDiagnostic>,
+ /// This flag indicates that an expected diagnostic was emitted and suppressed.
+ /// This is used for the `delayed_good_path_bugs` check.
+ suppressed_expected_diag: bool,
+
+ /// This set contains the `DiagnosticId` of all emitted diagnostics to avoid
+ /// emitting the same diagnostic with extended help (`--teach`) twice, which
+ /// would be unnecessary repetition.
+ taught_diagnostics: FxHashSet<DiagnosticId>,
+
+ /// Used to suggest rustc --explain <error code>
+ emitted_diagnostic_codes: FxHashSet<DiagnosticId>,
+
+ /// This set contains a hash of every diagnostic that has been emitted by
+ /// this handler. These hashes is used to avoid emitting the same error
+ /// twice.
+ emitted_diagnostics: FxHashSet<u128>,
+
+ /// Stashed diagnostics emitted in one stage of the compiler that may be
+ /// stolen by other stages (e.g. to improve them and add more information).
+ /// The stashed diagnostics count towards the total error count.
+ /// When `.abort_if_errors()` is called, these are also emitted.
+ stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>,
+
+ /// The warning count, used for a recap upon finishing
+ deduplicated_warn_count: usize,
+
+ future_breakage_diagnostics: Vec<Diagnostic>,
+
+ /// The [`Self::unstable_expect_diagnostics`] should be empty when this struct is
+ /// dropped. However, it can have values if the compilation is stopped early
+ /// or is only partially executed. To avoid ICEs, like in rust#94953 we only
+ /// check if [`Self::unstable_expect_diagnostics`] is empty, if the expectation ids
+ /// have been converted.
+ check_unstable_expect_diagnostics: bool,
+
+ /// Expected [`Diagnostic`]s store a [`LintExpectationId`] as part of
+ /// the lint level. [`LintExpectationId`]s created early during the compilation
+ /// (before `HirId`s have been defined) are not stable and can therefore not be
+ /// stored on disk. This buffer stores these diagnostics until the ID has been
+ /// replaced by a stable [`LintExpectationId`]. The [`Diagnostic`]s are the
+ /// submitted for storage and added to the list of fulfilled expectations.
+ unstable_expect_diagnostics: Vec<Diagnostic>,
+
+ /// expected diagnostic will have the level `Expect` which additionally
+ /// carries the [`LintExpectationId`] of the expectation that can be
+ /// marked as fulfilled. This is a collection of all [`LintExpectationId`]s
+ /// that have been marked as fulfilled this way.
+ ///
+ /// [RFC-2383]: https://rust-lang.github.io/rfcs/2383-lint-reasons.html
+ fulfilled_expectations: FxHashSet<LintExpectationId>,
+}
+
+/// A key denoting where from a diagnostic was stashed.
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub enum StashKey {
+ ItemNoType,
+}
+
+fn default_track_diagnostic(_: &Diagnostic) {}
+
+pub static TRACK_DIAGNOSTICS: AtomicRef<fn(&Diagnostic)> =
+ AtomicRef::new(&(default_track_diagnostic as fn(&_)));
+
+#[derive(Copy, Clone, Default)]
+pub struct HandlerFlags {
+ /// If false, warning-level lints are suppressed.
+ /// (rustc: see `--allow warnings` and `--cap-lints`)
+ pub can_emit_warnings: bool,
+ /// If true, error-level diagnostics are upgraded to bug-level.
+ /// (rustc: see `-Z treat-err-as-bug`)
+ pub treat_err_as_bug: Option<NonZeroUsize>,
+ /// If true, immediately emit diagnostics that would otherwise be buffered.
+ /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
+ pub dont_buffer_diagnostics: bool,
+ /// If true, immediately print bugs registered with `delay_span_bug`.
+ /// (rustc: see `-Z report-delayed-bugs`)
+ pub report_delayed_bugs: bool,
+ /// Show macro backtraces.
+ /// (rustc: see `-Z macro-backtrace`)
+ pub macro_backtrace: bool,
+ /// If true, identical diagnostics are reported only once.
+ pub deduplicate_diagnostics: bool,
+}
+
+impl Drop for HandlerInner {
+ fn drop(&mut self) {
+ self.emit_stashed_diagnostics();
+
+ if !self.has_errors() {
+ let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new());
+ self.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
+ }
+
+ // FIXME(eddyb) this explains what `delayed_good_path_bugs` are!
+ // They're `delayed_span_bugs` but for "require some diagnostic happened"
+ // instead of "require some error happened". Sadly that isn't ideal, as
+ // lints can be `#[allow]`'d, potentially leading to this triggering.
+ // Also, "good path" should be replaced with a better naming.
+ if !self.has_any_message() && !self.suppressed_expected_diag {
+ let bugs = std::mem::replace(&mut self.delayed_good_path_bugs, Vec::new());
+ self.flush_delayed(
+ bugs.into_iter().map(DelayedDiagnostic::decorate),
+ "no warnings or errors encountered even though `delayed_good_path_bugs` issued",
+ );
+ }
+
+ if self.check_unstable_expect_diagnostics {
+ assert!(
+ self.unstable_expect_diagnostics.is_empty(),
+ "all diagnostics with unstable expectations should have been converted",
+ );
+ }
+ }
+}
+
+impl Handler {
+ pub fn with_tty_emitter(
+ color_config: ColorConfig,
+ can_emit_warnings: bool,
+ treat_err_as_bug: Option<NonZeroUsize>,
+ sm: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ ) -> Self {
+ Self::with_tty_emitter_and_flags(
+ color_config,
+ sm,
+ fluent_bundle,
+ fallback_bundle,
+ HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
+ )
+ }
+
+ pub fn with_tty_emitter_and_flags(
+ color_config: ColorConfig,
+ sm: Option<Lrc<SourceMap>>,
+ fluent_bundle: Option<Lrc<FluentBundle>>,
+ fallback_bundle: LazyFallbackBundle,
+ flags: HandlerFlags,
+ ) -> Self {
+ let emitter = Box::new(EmitterWriter::stderr(
+ color_config,
+ sm,
+ fluent_bundle,
+ fallback_bundle,
+ false,
+ false,
+ None,
+ flags.macro_backtrace,
+ ));
+ Self::with_emitter_and_flags(emitter, flags)
+ }
+
+ pub fn with_emitter(
+ can_emit_warnings: bool,
+ treat_err_as_bug: Option<NonZeroUsize>,
+ emitter: Box<dyn Emitter + sync::Send>,
+ ) -> Self {
+ Handler::with_emitter_and_flags(
+ emitter,
+ HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
+ )
+ }
+
+ pub fn with_emitter_and_flags(
+ emitter: Box<dyn Emitter + sync::Send>,
+ flags: HandlerFlags,
+ ) -> Self {
+ Self {
+ flags,
+ inner: Lock::new(HandlerInner {
+ flags,
+ lint_err_count: 0,
+ err_count: 0,
+ warn_count: 0,
+ deduplicated_err_count: 0,
+ deduplicated_warn_count: 0,
+ emitter,
+ delayed_span_bugs: Vec::new(),
+ delayed_good_path_bugs: Vec::new(),
+ suppressed_expected_diag: false,
+ taught_diagnostics: Default::default(),
+ emitted_diagnostic_codes: Default::default(),
+ emitted_diagnostics: Default::default(),
+ stashed_diagnostics: Default::default(),
+ future_breakage_diagnostics: Vec::new(),
+ check_unstable_expect_diagnostics: false,
+ unstable_expect_diagnostics: Vec::new(),
+ fulfilled_expectations: Default::default(),
+ }),
+ }
+ }
+
+ // This is here to not allow mutation of flags;
+ // as of this writing it's only used in tests in librustc_middle.
+ pub fn can_emit_warnings(&self) -> bool {
+ self.flags.can_emit_warnings
+ }
+
+ /// Resets the diagnostic error count as well as the cached emitted diagnostics.
+ ///
+ /// NOTE: *do not* call this function from rustc. It is only meant to be called from external
+ /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
+ /// the overall count of emitted error diagnostics.
+ pub fn reset_err_count(&self) {
+ let mut inner = self.inner.borrow_mut();
+ inner.err_count = 0;
+ inner.warn_count = 0;
+ inner.deduplicated_err_count = 0;
+ inner.deduplicated_warn_count = 0;
+
+ // actually free the underlying memory (which `clear` would not do)
+ inner.delayed_span_bugs = Default::default();
+ inner.delayed_good_path_bugs = Default::default();
+ inner.taught_diagnostics = Default::default();
+ inner.emitted_diagnostic_codes = Default::default();
+ inner.emitted_diagnostics = Default::default();
+ inner.stashed_diagnostics = Default::default();
+ }
+
+ /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
+ pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
+ let mut inner = self.inner.borrow_mut();
+ // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
+ // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
+ // See the PR for a discussion.
+ inner.stashed_diagnostics.insert((span, key), diag);
+ }
+
+ /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
+ pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_, ()>> {
+ self.inner
+ .borrow_mut()
+ .stashed_diagnostics
+ .remove(&(span, key))
+ .map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
+ }
+
+ /// Emit all stashed diagnostics.
+ pub fn emit_stashed_diagnostics(&self) -> Option<ErrorGuaranteed> {
+ self.inner.borrow_mut().emit_stashed_diagnostics()
+ }
+
+ /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
+ ///
+ /// Attempting to `.emit()` the builder will only emit if either:
+ /// * `can_emit_warnings` is `true`
+ /// * `is_force_warn` was set in `DiagnosticId::Lint`
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_warn(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut result = self.struct_warn(msg);
+ result.set_span(span);
+ result
+ }
+
+ /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
+ /// The `id` is used for lint emissions which should also fulfill a lint expectation.
+ ///
+ /// Attempting to `.emit()` the builder will only emit if either:
+ /// * `can_emit_warnings` is `true`
+ /// * `is_force_warn` was set in `DiagnosticId::Lint`
+ pub fn struct_span_warn_with_expectation(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ id: LintExpectationId,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut result = self.struct_warn_with_expectation(msg, id);
+ result.set_span(span);
+ result
+ }
+
+ /// Construct a builder at the `Allow` level at the given `span` and with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_allow(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut result = self.struct_allow(msg);
+ result.set_span(span);
+ result
+ }
+
+ /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
+ /// Also include a code.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_warn_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut result = self.struct_span_warn(span, msg);
+ result.code(code);
+ result
+ }
+
+ /// Construct a builder at the `Warning` level with the `msg`.
+ ///
+ /// Attempting to `.emit()` the builder will only emit if either:
+ /// * `can_emit_warnings` is `true`
+ /// * `is_force_warn` was set in `DiagnosticId::Lint`
+ #[rustc_lint_diagnostics]
+ pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Warning(None), msg)
+ }
+
+ /// Construct a builder at the `Warning` level with the `msg`. The `id` is used for
+ /// lint emissions which should also fulfill a lint expectation.
+ ///
+ /// Attempting to `.emit()` the builder will only emit if either:
+ /// * `can_emit_warnings` is `true`
+ /// * `is_force_warn` was set in `DiagnosticId::Lint`
+ pub fn struct_warn_with_expectation(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ id: LintExpectationId,
+ ) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Warning(Some(id)), msg)
+ }
+
+ /// Construct a builder at the `Allow` level with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_allow(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Allow, msg)
+ }
+
+ /// Construct a builder at the `Expect` level with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_expect(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ id: LintExpectationId,
+ ) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Expect(id), msg)
+ }
+
+ /// Construct a builder at the `Error` level at the given `span` and with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_err(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+ let mut result = self.struct_err(msg);
+ result.set_span(span);
+ result
+ }
+
+ /// Construct a builder at the `Error` level at the given `span`, with the `msg`, and `code`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_err_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+ let mut result = self.struct_span_err(span, msg);
+ result.code(code);
+ result
+ }
+
+ /// Construct a builder at the `Error` level with the `msg`.
+ // FIXME: This method should be removed (every error should have an associated error code).
+ #[rustc_lint_diagnostics]
+ pub fn struct_err(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+ DiagnosticBuilder::new_guaranteeing_error::<_, { Level::Error { lint: false } }>(self, msg)
+ }
+
+ /// This should only be used by `rustc_middle::lint::struct_lint_level`. Do not use it for hard errors.
+ #[doc(hidden)]
+ pub fn struct_err_lint(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Error { lint: true }, msg)
+ }
+
+ /// Construct a builder at the `Error` level with the `msg` and the `code`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_err_with_code(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+ let mut result = self.struct_err(msg);
+ result.code(code);
+ result
+ }
+
+ /// Construct a builder at the `Warn` level with the `msg` and the `code`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_warn_with_code(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut result = self.struct_warn(msg);
+ result.code(code);
+ result
+ }
+
+ /// Construct a builder at the `Fatal` level at the given `span` and with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_fatal(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, !> {
+ let mut result = self.struct_fatal(msg);
+ result.set_span(span);
+ result
+ }
+
+ /// Construct a builder at the `Fatal` level at the given `span`, with the `msg`, and `code`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_span_fatal_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> DiagnosticBuilder<'_, !> {
+ let mut result = self.struct_span_fatal(span, msg);
+ result.code(code);
+ result
+ }
+
+ /// Construct a builder at the `Error` level with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_fatal(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, !> {
+ DiagnosticBuilder::new_fatal(self, msg)
+ }
+
+ /// Construct a builder at the `Help` level with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_help(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Help, msg)
+ }
+
+ /// Construct a builder at the `Note` level with the `msg`.
+ #[rustc_lint_diagnostics]
+ pub fn struct_note_without_error(
+ &self,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ()> {
+ DiagnosticBuilder::new(self, Level::Note, msg)
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+ self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span);
+ FatalError.raise()
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_fatal_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) -> ! {
+ self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span);
+ FatalError.raise()
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_err(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> ErrorGuaranteed {
+ self.emit_diag_at_span(Diagnostic::new(Error { lint: false }, msg), span).unwrap()
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_err_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) {
+ self.emit_diag_at_span(
+ Diagnostic::new_with_code(Error { lint: false }, Some(code), msg),
+ span,
+ );
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+ self.emit_diag_at_span(Diagnostic::new(Warning(None), msg), span);
+ }
+
+ #[rustc_lint_diagnostics]
+ pub fn span_warn_with_code(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ code: DiagnosticId,
+ ) {
+ self.emit_diag_at_span(Diagnostic::new_with_code(Warning(None), Some(code), msg), span);
+ }
+
+ pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+ self.inner.borrow_mut().span_bug(span, msg)
+ }
+
+ #[track_caller]
+ pub fn delay_span_bug(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> ErrorGuaranteed {
+ self.inner.borrow_mut().delay_span_bug(span, msg)
+ }
+
+ // FIXME(eddyb) note the comment inside `impl Drop for HandlerInner`, that's
+ // where the explanation of what "good path" is (also, it should be renamed).
+ pub fn delay_good_path_bug(&self, msg: impl Into<DiagnosticMessage>) {
+ self.inner.borrow_mut().delay_good_path_bug(msg)
+ }
+
+ pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+ self.emit_diag_at_span(Diagnostic::new(Bug, msg), span);
+ }
+
+ pub fn span_note_without_error(
+ &self,
+ span: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) {
+ self.emit_diag_at_span(Diagnostic::new(Note, msg), span);
+ }
+
+ pub fn span_note_diag(
+ &self,
+ span: Span,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> DiagnosticBuilder<'_, ()> {
+ let mut db = DiagnosticBuilder::new(self, Note, msg);
+ db.set_span(span);
+ db
+ }
+
+ // NOTE: intentionally doesn't raise an error so rustc_codegen_ssa only reports fatal errors in the main thread
+ pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> FatalError {
+ self.inner.borrow_mut().fatal(msg)
+ }
+
+ pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+ self.inner.borrow_mut().err(msg)
+ }
+
+ pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
+ let mut db = DiagnosticBuilder::new(self, Warning(None), msg);
+ db.emit();
+ }
+
+ pub fn note_without_error(&self, msg: impl Into<DiagnosticMessage>) {
+ DiagnosticBuilder::new(self, Note, msg).emit();
+ }
+
+ pub fn bug(&self, msg: impl Into<DiagnosticMessage>) -> ! {
+ self.inner.borrow_mut().bug(msg)
+ }
+
+ #[inline]
+ pub fn err_count(&self) -> usize {
+ self.inner.borrow().err_count()
+ }
+
+ pub fn has_errors(&self) -> Option<ErrorGuaranteed> {
+ if self.inner.borrow().has_errors() { Some(ErrorGuaranteed(())) } else { None }
+ }
+ pub fn has_errors_or_lint_errors(&self) -> Option<ErrorGuaranteed> {
+ if self.inner.borrow().has_errors_or_lint_errors() {
+ Some(ErrorGuaranteed(()))
+ } else {
+ None
+ }
+ }
+ pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
+ self.inner.borrow().has_errors_or_delayed_span_bugs()
+ }
+
+ pub fn print_error_count(&self, registry: &Registry) {
+ self.inner.borrow_mut().print_error_count(registry)
+ }
+
+ pub fn take_future_breakage_diagnostics(&self) -> Vec<Diagnostic> {
+ std::mem::take(&mut self.inner.borrow_mut().future_breakage_diagnostics)
+ }
+
+ pub fn abort_if_errors(&self) {
+ self.inner.borrow_mut().abort_if_errors()
+ }
+
+ /// `true` if we haven't taught a diagnostic with this code already.
+ /// The caller must then teach the user about such a diagnostic.
+ ///
+ /// Used to suppress emitting the same error multiple times with extended explanation when
+ /// calling `-Zteach`.
+ pub fn must_teach(&self, code: &DiagnosticId) -> bool {
+ self.inner.borrow_mut().must_teach(code)
+ }
+
+ pub fn force_print_diagnostic(&self, db: Diagnostic) {
+ self.inner.borrow_mut().force_print_diagnostic(db)
+ }
+
+ pub fn emit_diagnostic(&self, diagnostic: &mut Diagnostic) -> Option<ErrorGuaranteed> {
+ self.inner.borrow_mut().emit_diagnostic(diagnostic)
+ }
+
+ fn emit_diag_at_span(
+ &self,
+ mut diag: Diagnostic,
+ sp: impl Into<MultiSpan>,
+ ) -> Option<ErrorGuaranteed> {
+ let mut inner = self.inner.borrow_mut();
+ inner.emit_diagnostic(diag.set_span(sp))
+ }
+
+ pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
+ self.inner.borrow_mut().emit_artifact_notification(path, artifact_type)
+ }
+
+ pub fn emit_future_breakage_report(&self, diags: Vec<Diagnostic>) {
+ self.inner.borrow_mut().emitter.emit_future_breakage_report(diags)
+ }
+
+ pub fn emit_unused_externs(
+ &self,
+ lint_level: rustc_lint_defs::Level,
+ loud: bool,
+ unused_externs: &[&str],
+ ) {
+ let mut inner = self.inner.borrow_mut();
+
+ if loud && lint_level.is_error() {
+ inner.bump_err_count();
+ }
+
+ inner.emit_unused_externs(lint_level, unused_externs)
+ }
+
+ pub fn update_unstable_expectation_id(
+ &self,
+ unstable_to_stable: &FxHashMap<LintExpectationId, LintExpectationId>,
+ ) {
+ let mut inner = self.inner.borrow_mut();
+ let diags = std::mem::take(&mut inner.unstable_expect_diagnostics);
+ inner.check_unstable_expect_diagnostics = true;
+
+ if !diags.is_empty() {
+ inner.suppressed_expected_diag = true;
+ for mut diag in diags.into_iter() {
+ diag.update_unstable_expectation_id(unstable_to_stable);
+
+ // Here the diagnostic is given back to `emit_diagnostic` where it was first
+ // intercepted. Now it should be processed as usual, since the unstable expectation
+ // id is now stable.
+ inner.emit_diagnostic(&mut diag);
+ }
+ }
+
+ inner
+ .stashed_diagnostics
+ .values_mut()
+ .for_each(|diag| diag.update_unstable_expectation_id(unstable_to_stable));
+ inner
+ .future_breakage_diagnostics
+ .iter_mut()
+ .for_each(|diag| diag.update_unstable_expectation_id(unstable_to_stable));
+ }
+
+ /// This methods steals all [`LintExpectationId`]s that are stored inside
+ /// [`HandlerInner`] and indicate that the linked expectation has been fulfilled.
+ #[must_use]
+ pub fn steal_fulfilled_expectation_ids(&self) -> FxHashSet<LintExpectationId> {
+ assert!(
+ self.inner.borrow().unstable_expect_diagnostics.is_empty(),
+ "`HandlerInner::unstable_expect_diagnostics` should be empty at this point",
+ );
+ std::mem::take(&mut self.inner.borrow_mut().fulfilled_expectations)
+ }
+}
+
+impl HandlerInner {
+ fn must_teach(&mut self, code: &DiagnosticId) -> bool {
+ self.taught_diagnostics.insert(code.clone())
+ }
+
+ fn force_print_diagnostic(&mut self, mut db: Diagnostic) {
+ self.emitter.emit_diagnostic(&mut db);
+ }
+
+ /// Emit all stashed diagnostics.
+ fn emit_stashed_diagnostics(&mut self) -> Option<ErrorGuaranteed> {
+ let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>();
+ let mut reported = None;
+ for mut diag in diags {
+ if diag.is_error() {
+ reported = Some(ErrorGuaranteed(()));
+ }
+ self.emit_diagnostic(&mut diag);
+ }
+ reported
+ }
+
+ // FIXME(eddyb) this should ideally take `diagnostic` by value.
+ fn emit_diagnostic(&mut self, diagnostic: &mut Diagnostic) -> Option<ErrorGuaranteed> {
+ // The `LintExpectationId` can be stable or unstable depending on when it was created.
+ // Diagnostics created before the definition of `HirId`s are unstable and can not yet
+ // be stored. Instead, they are buffered until the `LintExpectationId` is replaced by
+ // a stable one by the `LintLevelsBuilder`.
+ if let Some(LintExpectationId::Unstable { .. }) = diagnostic.level.get_expectation_id() {
+ self.unstable_expect_diagnostics.push(diagnostic.clone());
+ return None;
+ }
+
+ if diagnostic.level == Level::DelayedBug {
+ // FIXME(eddyb) this should check for `has_errors` and stop pushing
+ // once *any* errors were emitted (and truncate `delayed_span_bugs`
+ // when an error is first emitted, also), but maybe there's a case
+ // in which that's not sound? otherwise this is really inefficient.
+ self.delayed_span_bugs.push(diagnostic.clone());
+
+ if !self.flags.report_delayed_bugs {
+ return Some(ErrorGuaranteed::unchecked_claim_error_was_emitted());
+ }
+ }
+
+ if diagnostic.has_future_breakage() {
+ self.future_breakage_diagnostics.push(diagnostic.clone());
+ }
+
+ if let Some(expectation_id) = diagnostic.level.get_expectation_id() {
+ self.suppressed_expected_diag = true;
+ self.fulfilled_expectations.insert(expectation_id);
+ }
+
+ if matches!(diagnostic.level, Warning(_))
+ && !self.flags.can_emit_warnings
+ && !diagnostic.is_force_warn()
+ {
+ if diagnostic.has_future_breakage() {
+ (*TRACK_DIAGNOSTICS)(diagnostic);
+ }
+ return None;
+ }
+
+ (*TRACK_DIAGNOSTICS)(diagnostic);
+
+ if matches!(diagnostic.level, Level::Expect(_) | Level::Allow) {
+ return None;
+ }
+
+ if let Some(ref code) = diagnostic.code {
+ self.emitted_diagnostic_codes.insert(code.clone());
+ }
+
+ let already_emitted = |this: &mut Self| {
+ let mut hasher = StableHasher::new();
+ diagnostic.hash(&mut hasher);
+ let diagnostic_hash = hasher.finish();
+ !this.emitted_diagnostics.insert(diagnostic_hash)
+ };
+
+ // Only emit the diagnostic if we've been asked to deduplicate or
+ // haven't already emitted an equivalent diagnostic.
+ if !(self.flags.deduplicate_diagnostics && already_emitted(self)) {
+ debug!(?diagnostic);
+ debug!(?self.emitted_diagnostics);
+ let already_emitted_sub = |sub: &mut SubDiagnostic| {
+ debug!(?sub);
+ if sub.level != Level::OnceNote {
+ return false;
+ }
+ let mut hasher = StableHasher::new();
+ sub.hash(&mut hasher);
+ let diagnostic_hash = hasher.finish();
+ debug!(?diagnostic_hash);
+ !self.emitted_diagnostics.insert(diagnostic_hash)
+ };
+
+ diagnostic.children.drain_filter(already_emitted_sub).for_each(|_| {});
+
+ self.emitter.emit_diagnostic(&diagnostic);
+ if diagnostic.is_error() {
+ self.deduplicated_err_count += 1;
+ } else if let Warning(_) = diagnostic.level {
+ self.deduplicated_warn_count += 1;
+ }
+ }
+ if diagnostic.is_error() {
+ if matches!(diagnostic.level, Level::Error { lint: true }) {
+ self.bump_lint_err_count();
+ } else {
+ self.bump_err_count();
+ }
+
+ Some(ErrorGuaranteed::unchecked_claim_error_was_emitted())
+ } else {
+ self.bump_warn_count();
+
+ None
+ }
+ }
+
+ fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) {
+ self.emitter.emit_artifact_notification(path, artifact_type);
+ }
+
+ fn emit_unused_externs(&mut self, lint_level: rustc_lint_defs::Level, unused_externs: &[&str]) {
+ self.emitter.emit_unused_externs(lint_level, unused_externs);
+ }
+
+ fn treat_err_as_bug(&self) -> bool {
+ self.flags
+ .treat_err_as_bug
+ .map_or(false, |c| self.err_count() + self.lint_err_count >= c.get())
+ }
+
+ fn print_error_count(&mut self, registry: &Registry) {
+ self.emit_stashed_diagnostics();
+
+ let warnings = match self.deduplicated_warn_count {
+ 0 => String::new(),
+ 1 => "1 warning emitted".to_string(),
+ count => format!("{count} warnings emitted"),
+ };
+ let errors = match self.deduplicated_err_count {
+ 0 => String::new(),
+ 1 => "aborting due to previous error".to_string(),
+ count => format!("aborting due to {count} previous errors"),
+ };
+ if self.treat_err_as_bug() {
+ return;
+ }
+
+ match (errors.len(), warnings.len()) {
+ (0, 0) => return,
+ (0, _) => self.emitter.emit_diagnostic(&Diagnostic::new(
+ Level::Warning(None),
+ DiagnosticMessage::Str(warnings),
+ )),
+ (_, 0) => {
+ let _ = self.fatal(&errors);
+ }
+ (_, _) => {
+ let _ = self.fatal(&format!("{}; {}", &errors, &warnings));
+ }
+ }
+
+ let can_show_explain = self.emitter.should_show_explain();
+ let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty();
+ if can_show_explain && are_there_diagnostics {
+ let mut error_codes = self
+ .emitted_diagnostic_codes
+ .iter()
+ .filter_map(|x| match &x {
+ DiagnosticId::Error(s)
+ if registry.try_find_description(s).map_or(false, |o| o.is_some()) =>
+ {
+ Some(s.clone())
+ }
+ _ => None,
+ })
+ .collect::<Vec<_>>();
+ if !error_codes.is_empty() {
+ error_codes.sort();
+ if error_codes.len() > 1 {
+ let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
+ self.failure(&format!(
+ "Some errors have detailed explanations: {}{}",
+ error_codes[..limit].join(", "),
+ if error_codes.len() > 9 { "..." } else { "." }
+ ));
+ self.failure(&format!(
+ "For more information about an error, try \
+ `rustc --explain {}`.",
+ &error_codes[0]
+ ));
+ } else {
+ self.failure(&format!(
+ "For more information about this error, try \
+ `rustc --explain {}`.",
+ &error_codes[0]
+ ));
+ }
+ }
+ }
+ }
+
+ #[inline]
+ fn err_count(&self) -> usize {
+ self.err_count + self.stashed_diagnostics.len()
+ }
+
+ fn has_errors(&self) -> bool {
+ self.err_count() > 0
+ }
+ fn has_errors_or_lint_errors(&self) -> bool {
+ self.has_errors() || self.lint_err_count > 0
+ }
+ fn has_errors_or_delayed_span_bugs(&self) -> bool {
+ self.has_errors() || !self.delayed_span_bugs.is_empty()
+ }
+ fn has_any_message(&self) -> bool {
+ self.err_count() > 0 || self.lint_err_count > 0 || self.warn_count > 0
+ }
+
+ fn abort_if_errors(&mut self) {
+ self.emit_stashed_diagnostics();
+
+ if self.has_errors() {
+ FatalError.raise();
+ }
+ }
+
+ fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+ self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp);
+ panic::panic_any(ExplicitBug);
+ }
+
+ fn emit_diag_at_span(&mut self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
+ self.emit_diagnostic(diag.set_span(sp));
+ }
+
+ #[track_caller]
+ fn delay_span_bug(
+ &mut self,
+ sp: impl Into<MultiSpan>,
+ msg: impl Into<DiagnosticMessage>,
+ ) -> ErrorGuaranteed {
+ // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
+ // incrementing `err_count` by one, so we need to +1 the comparing.
+ // FIXME: Would be nice to increment err_count in a more coherent way.
+ if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c.get()) {
+ // FIXME: don't abort here if report_delayed_bugs is off
+ self.span_bug(sp, msg);
+ }
+ let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg);
+ diagnostic.set_span(sp.into());
+ diagnostic.note(&format!("delayed at {}", std::panic::Location::caller()));
+ self.emit_diagnostic(&mut diagnostic).unwrap()
+ }
+
+ // FIXME(eddyb) note the comment inside `impl Drop for HandlerInner`, that's
+ // where the explanation of what "good path" is (also, it should be renamed).
+ fn delay_good_path_bug(&mut self, msg: impl Into<DiagnosticMessage>) {
+ let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg);
+ if self.flags.report_delayed_bugs {
+ self.emit_diagnostic(&mut diagnostic);
+ }
+ let backtrace = std::backtrace::Backtrace::force_capture();
+ self.delayed_good_path_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace));
+ }
+
+ fn failure(&mut self, msg: impl Into<DiagnosticMessage>) {
+ self.emit_diagnostic(&mut Diagnostic::new(FailureNote, msg));
+ }
+
+ fn fatal(&mut self, msg: impl Into<DiagnosticMessage>) -> FatalError {
+ self.emit(Fatal, msg);
+ FatalError
+ }
+
+ fn err(&mut self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+ self.emit(Error { lint: false }, msg)
+ }
+
+ /// Emit an error; level should be `Error` or `Fatal`.
+ fn emit(&mut self, level: Level, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
+ if self.treat_err_as_bug() {
+ self.bug(msg);
+ }
+ self.emit_diagnostic(&mut Diagnostic::new(level, msg)).unwrap()
+ }
+
+ fn bug(&mut self, msg: impl Into<DiagnosticMessage>) -> ! {
+ self.emit_diagnostic(&mut Diagnostic::new(Bug, msg));
+ panic::panic_any(ExplicitBug);
+ }
+
+ fn flush_delayed(
+ &mut self,
+ bugs: impl IntoIterator<Item = Diagnostic>,
+ explanation: impl Into<DiagnosticMessage> + Copy,
+ ) {
+ let mut no_bugs = true;
+ for mut bug in bugs {
+ if no_bugs {
+ // Put the overall explanation before the `DelayedBug`s, to
+ // frame them better (e.g. separate warnings from them).
+ self.emit_diagnostic(&mut Diagnostic::new(Bug, explanation));
+ no_bugs = false;
+ }
+
+ // "Undelay" the `DelayedBug`s (into plain `Bug`s).
+ if bug.level != Level::DelayedBug {
+ // NOTE(eddyb) not panicking here because we're already producing
+ // an ICE, and the more information the merrier.
+ bug.note(&format!(
+ "`flushed_delayed` got diagnostic with level {:?}, \
+ instead of the expected `DelayedBug`",
+ bug.level,
+ ));
+ }
+ bug.level = Level::Bug;
+
+ self.emit_diagnostic(&mut bug);
+ }
+
+ // Panic with `ExplicitBug` to avoid "unexpected panic" messages.
+ if !no_bugs {
+ panic::panic_any(ExplicitBug);
+ }
+ }
+
+ fn bump_lint_err_count(&mut self) {
+ self.lint_err_count += 1;
+ self.panic_if_treat_err_as_bug();
+ }
+
+ fn bump_err_count(&mut self) {
+ self.err_count += 1;
+ self.panic_if_treat_err_as_bug();
+ }
+
+ fn bump_warn_count(&mut self) {
+ self.warn_count += 1;
+ }
+
+ fn panic_if_treat_err_as_bug(&self) {
+ if self.treat_err_as_bug() {
+ match (
+ self.err_count() + self.lint_err_count,
+ self.flags.treat_err_as_bug.map(|c| c.get()).unwrap_or(0),
+ ) {
+ (1, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
+ (0 | 1, _) => {}
+ (count, as_bug) => panic!(
+ "aborting after {} errors due to `-Z treat-err-as-bug={}`",
+ count, as_bug,
+ ),
+ }
+ }
+ }
+}
+
+struct DelayedDiagnostic {
+ inner: Diagnostic,
+ note: Backtrace,
+}
+
+impl DelayedDiagnostic {
+ fn with_backtrace(diagnostic: Diagnostic, backtrace: Backtrace) -> Self {
+ DelayedDiagnostic { inner: diagnostic, note: backtrace }
+ }
+
+ fn decorate(mut self) -> Diagnostic {
+ self.inner.note(&format!("delayed at {}", self.note));
+ self.inner
+ }
+}
+
+#[derive(Copy, PartialEq, Eq, Clone, Hash, Debug, Encodable, Decodable)]
+pub enum Level {
+ Bug,
+ DelayedBug,
+ Fatal,
+ Error {
+ /// If this error comes from a lint, don't abort compilation even when abort_if_errors() is called.
+ lint: bool,
+ },
+ /// This [`LintExpectationId`] is used for expected lint diagnostics, which should
+ /// also emit a warning due to the `force-warn` flag. In all other cases this should
+ /// be `None`.
+ Warning(Option<LintExpectationId>),
+ Note,
+ /// A note that is only emitted once.
+ OnceNote,
+ Help,
+ FailureNote,
+ Allow,
+ Expect(LintExpectationId),
+}
+
+impl fmt::Display for Level {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.to_str().fmt(f)
+ }
+}
+
+impl Level {
+ fn color(self) -> ColorSpec {
+ let mut spec = ColorSpec::new();
+ match self {
+ Bug | DelayedBug | Fatal | Error { .. } => {
+ spec.set_fg(Some(Color::Red)).set_intense(true);
+ }
+ Warning(_) => {
+ spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows));
+ }
+ Note | OnceNote => {
+ spec.set_fg(Some(Color::Green)).set_intense(true);
+ }
+ Help => {
+ spec.set_fg(Some(Color::Cyan)).set_intense(true);
+ }
+ FailureNote => {}
+ Allow | Expect(_) => unreachable!(),
+ }
+ spec
+ }
+
+ pub fn to_str(self) -> &'static str {
+ match self {
+ Bug | DelayedBug => "error: internal compiler error",
+ Fatal | Error { .. } => "error",
+ Warning(_) => "warning",
+ Note | OnceNote => "note",
+ Help => "help",
+ FailureNote => "failure-note",
+ Allow => panic!("Shouldn't call on allowed error"),
+ Expect(_) => panic!("Shouldn't call on expected error"),
+ }
+ }
+
+ pub fn is_failure_note(&self) -> bool {
+ matches!(*self, FailureNote)
+ }
+
+ pub fn get_expectation_id(&self) -> Option<LintExpectationId> {
+ match self {
+ Level::Expect(id) | Level::Warning(Some(id)) => Some(*id),
+ _ => None,
+ }
+ }
+}
+
+// FIXME(eddyb) this doesn't belong here AFAICT, should be moved to callsite.
+pub fn add_elided_lifetime_in_path_suggestion(
+ source_map: &SourceMap,
+ diag: &mut Diagnostic,
+ n: usize,
+ path_span: Span,
+ incl_angl_brckt: bool,
+ insertion_span: Span,
+) {
+ diag.span_label(path_span, format!("expected lifetime parameter{}", pluralize!(n)));
+ if !source_map.is_span_accessible(insertion_span) {
+ // Do not try to suggest anything if generated by a proc-macro.
+ return;
+ }
+ let anon_lts = vec!["'_"; n].join(", ");
+ let suggestion =
+ if incl_angl_brckt { format!("<{}>", anon_lts) } else { format!("{}, ", anon_lts) };
+ diag.span_suggestion_verbose(
+ insertion_span.shrink_to_hi(),
+ &format!("indicate the anonymous lifetime{}", pluralize!(n)),
+ suggestion,
+ Applicability::MachineApplicable,
+ );
+}
+
+/// Useful type to use with `Result<>` indicate that an error has already
+/// been reported to the user, so no need to continue checking.
+#[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(HashStable_Generic)]
+pub struct ErrorGuaranteed(());
+
+impl ErrorGuaranteed {
+ /// To be used only if you really know what you are doing... ideally, we would find a way to
+ /// eliminate all calls to this method.
+ pub fn unchecked_claim_error_was_emitted() -> Self {
+ ErrorGuaranteed(())
+ }
+}
diff --git a/compiler/rustc_errors/src/lock.rs b/compiler/rustc_errors/src/lock.rs
new file mode 100644
index 000000000..a73472021
--- /dev/null
+++ b/compiler/rustc_errors/src/lock.rs
@@ -0,0 +1,93 @@
+//! Bindings to acquire a global named lock.
+//!
+//! This is intended to be used to synchronize multiple compiler processes to
+//! ensure that we can output complete errors without interleaving on Windows.
+//! Note that this is currently only needed for allowing only one 32-bit MSVC
+//! linker to execute at once on MSVC hosts, so this is only implemented for
+//! `cfg(windows)`. Also note that this may not always be used on Windows,
+//! only when targeting 32-bit MSVC.
+//!
+//! For more information about why this is necessary, see where this is called.
+
+use std::any::Any;
+
+#[cfg(windows)]
+pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
+ use std::ffi::CString;
+ use std::io;
+
+ use winapi::shared::ntdef::HANDLE;
+ use winapi::um::handleapi::CloseHandle;
+ use winapi::um::synchapi::{CreateMutexA, ReleaseMutex, WaitForSingleObject};
+ use winapi::um::winbase::{INFINITE, WAIT_ABANDONED, WAIT_OBJECT_0};
+
+ struct Handle(HANDLE);
+
+ impl Drop for Handle {
+ fn drop(&mut self) {
+ unsafe {
+ CloseHandle(self.0);
+ }
+ }
+ }
+
+ struct Guard(Handle);
+
+ impl Drop for Guard {
+ fn drop(&mut self) {
+ unsafe {
+ ReleaseMutex((self.0).0);
+ }
+ }
+ }
+
+ let cname = CString::new(name).unwrap();
+ unsafe {
+ // Create a named mutex, with no security attributes and also not
+ // acquired when we create it.
+ //
+ // This will silently create one if it doesn't already exist, or it'll
+ // open up a handle to one if it already exists.
+ let mutex = CreateMutexA(std::ptr::null_mut(), 0, cname.as_ptr());
+ if mutex.is_null() {
+ panic!(
+ "failed to create global mutex named `{}`: {}",
+ name,
+ io::Error::last_os_error()
+ );
+ }
+ let mutex = Handle(mutex);
+
+ // Acquire the lock through `WaitForSingleObject`.
+ //
+ // A return value of `WAIT_OBJECT_0` means we successfully acquired it.
+ //
+ // A return value of `WAIT_ABANDONED` means that the previous holder of
+ // the thread exited without calling `ReleaseMutex`. This can happen,
+ // for example, when the compiler crashes or is interrupted via ctrl-c
+ // or the like. In this case, however, we are still transferred
+ // ownership of the lock so we continue.
+ //
+ // If an error happens.. well... that's surprising!
+ match WaitForSingleObject(mutex.0, INFINITE) {
+ WAIT_OBJECT_0 | WAIT_ABANDONED => {}
+ code => {
+ panic!(
+ "WaitForSingleObject failed on global mutex named \
+ `{}`: {} (ret={:x})",
+ name,
+ io::Error::last_os_error(),
+ code
+ );
+ }
+ }
+
+ // Return a guard which will call `ReleaseMutex` when dropped.
+ Box::new(Guard(mutex))
+ }
+}
+
+#[cfg(not(windows))]
+pub fn acquire_global_lock(_name: &str) -> Box<dyn Any> {
+ Box::new(())
+}
diff --git a/compiler/rustc_errors/src/registry.rs b/compiler/rustc_errors/src/registry.rs
new file mode 100644
index 000000000..da764d993
--- /dev/null
+++ b/compiler/rustc_errors/src/registry.rs
@@ -0,0 +1,25 @@
+use rustc_data_structures::fx::FxHashMap;
+
+#[derive(Debug)]
+pub struct InvalidErrorCode;
+
+#[derive(Clone)]
+pub struct Registry {
+ long_descriptions: FxHashMap<&'static str, Option<&'static str>>,
+}
+
+impl Registry {
+ pub fn new(long_descriptions: &[(&'static str, Option<&'static str>)]) -> Registry {
+ Registry { long_descriptions: long_descriptions.iter().copied().collect() }
+ }
+
+ /// Returns `InvalidErrorCode` if the code requested does not exist in the
+ /// registry. Otherwise, returns an `Option` where `None` means the error
+ /// code is valid but has no extended information.
+ pub fn try_find_description(
+ &self,
+ code: &str,
+ ) -> Result<Option<&'static str>, InvalidErrorCode> {
+ self.long_descriptions.get(code).copied().ok_or(InvalidErrorCode)
+ }
+}
diff --git a/compiler/rustc_errors/src/snippet.rs b/compiler/rustc_errors/src/snippet.rs
new file mode 100644
index 000000000..e4cc44c41
--- /dev/null
+++ b/compiler/rustc_errors/src/snippet.rs
@@ -0,0 +1,179 @@
+// Code for annotating snippets.
+
+use crate::Level;
+
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+pub struct Line {
+ pub line_index: usize,
+ pub annotations: Vec<Annotation>,
+}
+
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+pub struct MultilineAnnotation {
+ pub depth: usize,
+ pub line_start: usize,
+ pub line_end: usize,
+ pub start_col: usize,
+ pub end_col: usize,
+ pub is_primary: bool,
+ pub label: Option<String>,
+ pub overlaps_exactly: bool,
+}
+
+impl MultilineAnnotation {
+ pub fn increase_depth(&mut self) {
+ self.depth += 1;
+ }
+
+ /// Compare two `MultilineAnnotation`s considering only the `Span` they cover.
+ pub fn same_span(&self, other: &MultilineAnnotation) -> bool {
+ self.line_start == other.line_start
+ && self.line_end == other.line_end
+ && self.start_col == other.start_col
+ && self.end_col == other.end_col
+ }
+
+ pub fn as_start(&self) -> Annotation {
+ Annotation {
+ start_col: self.start_col,
+ end_col: self.start_col + 1,
+ is_primary: self.is_primary,
+ label: None,
+ annotation_type: AnnotationType::MultilineStart(self.depth),
+ }
+ }
+
+ pub fn as_end(&self) -> Annotation {
+ Annotation {
+ start_col: self.end_col.saturating_sub(1),
+ end_col: self.end_col,
+ is_primary: self.is_primary,
+ label: self.label.clone(),
+ annotation_type: AnnotationType::MultilineEnd(self.depth),
+ }
+ }
+
+ pub fn as_line(&self) -> Annotation {
+ Annotation {
+ start_col: 0,
+ end_col: 0,
+ is_primary: self.is_primary,
+ label: None,
+ annotation_type: AnnotationType::MultilineLine(self.depth),
+ }
+ }
+}
+
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+pub enum AnnotationType {
+ /// Annotation under a single line of code
+ Singleline,
+
+ // The Multiline type above is replaced with the following three in order
+ // to reuse the current label drawing code.
+ //
+ // Each of these corresponds to one part of the following diagram:
+ //
+ // x | foo(1 + bar(x,
+ // | _________^ < MultilineStart
+ // x | | y), < MultilineLine
+ // | |______________^ label < MultilineEnd
+ // x | z);
+ /// Annotation marking the first character of a fully shown multiline span
+ MultilineStart(usize),
+ /// Annotation marking the last character of a fully shown multiline span
+ MultilineEnd(usize),
+ /// Line at the left enclosing the lines of a fully shown multiline span
+ // Just a placeholder for the drawing algorithm, to know that it shouldn't skip the first 4
+ // and last 2 lines of code. The actual line is drawn in `emit_message_default` and not in
+ // `draw_multiline_line`.
+ MultilineLine(usize),
+}
+
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+pub struct Annotation {
+ /// Start column, 0-based indexing -- counting *characters*, not
+ /// utf-8 bytes. Note that it is important that this field goes
+ /// first, so that when we sort, we sort orderings by start
+ /// column.
+ pub start_col: usize,
+
+ /// End column within the line (exclusive)
+ pub end_col: usize,
+
+ /// Is this annotation derived from primary span
+ pub is_primary: bool,
+
+ /// Optional label to display adjacent to the annotation.
+ pub label: Option<String>,
+
+ /// Is this a single line, multiline or multiline span minimized down to a
+ /// smaller span.
+ pub annotation_type: AnnotationType,
+}
+
+impl Annotation {
+ /// Whether this annotation is a vertical line placeholder.
+ pub fn is_line(&self) -> bool {
+ matches!(self.annotation_type, AnnotationType::MultilineLine(_))
+ }
+
+ pub fn len(&self) -> usize {
+ // Account for usize underflows
+ if self.end_col > self.start_col {
+ self.end_col - self.start_col
+ } else {
+ self.start_col - self.end_col
+ }
+ }
+
+ pub fn has_label(&self) -> bool {
+ if let Some(ref label) = self.label {
+ // Consider labels with no text as effectively not being there
+ // to avoid weird output with unnecessary vertical lines, like:
+ //
+ // X | fn foo(x: u32) {
+ // | -------^------
+ // | | |
+ // | |
+ // |
+ //
+ // Note that this would be the complete output users would see.
+ !label.is_empty()
+ } else {
+ false
+ }
+ }
+
+ pub fn takes_space(&self) -> bool {
+ // Multiline annotations always have to keep vertical space.
+ matches!(
+ self.annotation_type,
+ AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_)
+ )
+ }
+}
+
+#[derive(Debug)]
+pub struct StyledString {
+ pub text: String,
+ pub style: Style,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
+pub enum Style {
+ MainHeaderMsg,
+ HeaderMsg,
+ LineAndColumn,
+ LineNumber,
+ Quotation,
+ UnderlinePrimary,
+ UnderlineSecondary,
+ LabelPrimary,
+ LabelSecondary,
+ NoStyle,
+ Level(Level),
+ Highlight,
+ Addition,
+ Removal,
+}
diff --git a/compiler/rustc_errors/src/styled_buffer.rs b/compiler/rustc_errors/src/styled_buffer.rs
new file mode 100644
index 000000000..9abdb5fc9
--- /dev/null
+++ b/compiler/rustc_errors/src/styled_buffer.rs
@@ -0,0 +1,151 @@
+// Code for creating styled buffers
+
+use crate::snippet::{Style, StyledString};
+
+#[derive(Debug)]
+pub struct StyledBuffer {
+ lines: Vec<Vec<StyledChar>>,
+}
+
+#[derive(Debug, Clone)]
+struct StyledChar {
+ chr: char,
+ style: Style,
+}
+
+impl StyledChar {
+ const SPACE: Self = StyledChar::new(' ', Style::NoStyle);
+
+ const fn new(chr: char, style: Style) -> Self {
+ StyledChar { chr, style }
+ }
+}
+
+impl StyledBuffer {
+ pub fn new() -> StyledBuffer {
+ StyledBuffer { lines: vec![] }
+ }
+
+ /// Returns content of `StyledBuffer` split by lines and line styles
+ pub fn render(&self) -> Vec<Vec<StyledString>> {
+ // Tabs are assumed to have been replaced by spaces in calling code.
+ debug_assert!(self.lines.iter().all(|r| !r.iter().any(|sc| sc.chr == '\t')));
+
+ let mut output: Vec<Vec<StyledString>> = vec![];
+ let mut styled_vec: Vec<StyledString> = vec![];
+
+ for styled_line in &self.lines {
+ let mut current_style = Style::NoStyle;
+ let mut current_text = String::new();
+
+ for sc in styled_line {
+ if sc.style != current_style {
+ if !current_text.is_empty() {
+ styled_vec.push(StyledString { text: current_text, style: current_style });
+ }
+ current_style = sc.style;
+ current_text = String::new();
+ }
+ current_text.push(sc.chr);
+ }
+ if !current_text.is_empty() {
+ styled_vec.push(StyledString { text: current_text, style: current_style });
+ }
+
+ // We're done with the row, push and keep going
+ output.push(styled_vec);
+
+ styled_vec = vec![];
+ }
+
+ output
+ }
+
+ fn ensure_lines(&mut self, line: usize) {
+ if line >= self.lines.len() {
+ self.lines.resize(line + 1, Vec::new());
+ }
+ }
+
+ /// Sets `chr` with `style` for given `line`, `col`.
+ /// If `line` does not exist in our buffer, adds empty lines up to the given
+ /// and fills the last line with unstyled whitespace.
+ pub fn putc(&mut self, line: usize, col: usize, chr: char, style: Style) {
+ self.ensure_lines(line);
+ if col >= self.lines[line].len() {
+ self.lines[line].resize(col + 1, StyledChar::SPACE);
+ }
+ self.lines[line][col] = StyledChar::new(chr, style);
+ }
+
+ /// Sets `string` with `style` for given `line`, starting from `col`.
+ /// If `line` does not exist in our buffer, adds empty lines up to the given
+ /// and fills the last line with unstyled whitespace.
+ pub fn puts(&mut self, line: usize, col: usize, string: &str, style: Style) {
+ let mut n = col;
+ for c in string.chars() {
+ self.putc(line, n, c, style);
+ n += 1;
+ }
+ }
+
+ /// For given `line` inserts `string` with `style` before old content of that line,
+ /// adding lines if needed
+ pub fn prepend(&mut self, line: usize, string: &str, style: Style) {
+ self.ensure_lines(line);
+ let string_len = string.chars().count();
+
+ if !self.lines[line].is_empty() {
+ // Push the old content over to make room for new content
+ for _ in 0..string_len {
+ self.lines[line].insert(0, StyledChar::SPACE);
+ }
+ }
+
+ self.puts(line, 0, string, style);
+ }
+
+ /// For given `line` inserts `string` with `style` after old content of that line,
+ /// adding lines if needed
+ pub fn append(&mut self, line: usize, string: &str, style: Style) {
+ if line >= self.lines.len() {
+ self.puts(line, 0, string, style);
+ } else {
+ let col = self.lines[line].len();
+ self.puts(line, col, string, style);
+ }
+ }
+
+ pub fn num_lines(&self) -> usize {
+ self.lines.len()
+ }
+
+ /// Set `style` for `line`, `col_start..col_end` range if:
+ /// 1. That line and column range exist in `StyledBuffer`
+ /// 2. `overwrite` is `true` or existing style is `Style::NoStyle` or `Style::Quotation`
+ pub fn set_style_range(
+ &mut self,
+ line: usize,
+ col_start: usize,
+ col_end: usize,
+ style: Style,
+ overwrite: bool,
+ ) {
+ for col in col_start..col_end {
+ self.set_style(line, col, style, overwrite);
+ }
+ }
+
+ /// Set `style` for `line`, `col` if:
+ /// 1. That line and column exist in `StyledBuffer`
+ /// 2. `overwrite` is `true` or existing style is `Style::NoStyle` or `Style::Quotation`
+ pub fn set_style(&mut self, line: usize, col: usize, style: Style, overwrite: bool) {
+ if let Some(ref mut line) = self.lines.get_mut(line) {
+ if let Some(StyledChar { style: s, .. }) = line.get_mut(col) {
+ if overwrite || *s == Style::NoStyle || *s == Style::Quotation {
+ *s = style;
+ }
+ }
+ }
+ }
+}