1 //! Diagnostics creation and emission for `rustc`.
3 //! This module contains the code for creating and emitting diagnostics.
5 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
6 #![feature(crate_visibility_modifier)]
8 #![feature(format_args_capture)]
13 extern crate rustc_macros;
15 pub use emitter::ColorConfig;
20 use emitter::{is_case_difference, Emitter, EmitterWriter};
21 use registry::Registry;
22 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
23 use rustc_data_structures::stable_hasher::StableHasher;
24 use rustc_data_structures::sync::{self, Lock, Lrc};
25 use rustc_data_structures::AtomicRef;
26 pub use rustc_lint_defs::{pluralize, Applicability};
27 use rustc_serialize::json::Json;
28 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
29 use rustc_span::source_map::SourceMap;
30 use rustc_span::{Loc, MultiSpan, Span};
33 use std::hash::{Hash, Hasher};
34 use std::num::NonZeroUsize;
37 use std::{error, fmt};
39 use termcolor::{Color, ColorSpec};
41 pub mod annotate_snippet_emitter_writer;
43 mod diagnostic_builder;
50 pub use snippet::Style;
52 pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
54 // `PResult` is used a lot. Make sure it doesn't unintentionally get bigger.
55 // (See also the comment on `DiagnosticBuilderInner`.)
56 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
57 rustc_data_structures::static_assert_size!(PResult<'_, bool>, 16);
59 #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, Encodable, Decodable)]
60 pub enum SuggestionStyle {
61 /// Hide the suggested code when displaying this suggestion inline.
63 /// Always hide the suggested code but display the message.
65 /// Do not display this suggestion in the cli output, it is only meant for tools.
67 /// Always show the suggested code.
68 /// This will *not* show the code if the suggestion is inline *and* the suggested code is
71 /// Always show the suggested code independently.
75 impl SuggestionStyle {
76 fn hide_inline(&self) -> bool {
77 !matches!(*self, SuggestionStyle::ShowCode)
81 #[derive(Clone, Debug, PartialEq, Default)]
82 pub struct ToolMetadata(pub Option<Json>);
85 fn new(json: Json) -> Self {
86 ToolMetadata(Some(json))
89 fn is_set(&self) -> bool {
94 impl Hash for ToolMetadata {
95 fn hash<H: Hasher>(&self, _state: &mut H) {}
98 // Doesn't really need to round-trip
99 impl<D: Decoder> Decodable<D> for ToolMetadata {
100 fn decode(_d: &mut D) -> Result<Self, D::Error> {
101 Ok(ToolMetadata(None))
105 impl<S: Encoder> Encodable<S> for ToolMetadata {
106 fn encode(&self, e: &mut S) -> Result<(), S::Error> {
108 None => e.emit_unit(),
109 Some(json) => json.encode(e),
114 #[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
115 pub struct CodeSuggestion {
116 /// Each substitute can have multiple variants due to multiple
117 /// applicable suggestions
119 /// `foo.bar` might be replaced with `a.b` or `x.y` by replacing
120 /// `foo` and `bar` on their own:
124 /// Substitution { parts: vec![(0..3, "a"), (4..7, "b")] },
125 /// Substitution { parts: vec![(0..3, "x"), (4..7, "y")] },
129 /// or by replacing the entire span:
133 /// Substitution { parts: vec![(0..7, "a.b")] },
134 /// Substitution { parts: vec![(0..7, "x.y")] },
137 pub substitutions: Vec<Substitution>,
139 /// Visual representation of this suggestion.
140 pub style: SuggestionStyle,
141 /// Whether or not the suggestion is approximate
143 /// Sometimes we may show suggestions with placeholders,
144 /// which are useful for users but not useful for
145 /// tools like rustfix
146 pub applicability: Applicability,
147 /// Tool-specific metadata
148 pub tool_metadata: ToolMetadata,
151 #[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
152 /// See the docs on `CodeSuggestion::substitutions`
153 pub struct Substitution {
154 pub parts: Vec<SubstitutionPart>,
157 #[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
158 pub struct SubstitutionPart {
163 impl CodeSuggestion {
164 /// Returns the assembled code suggestions, whether they should be shown with an underline
165 /// and whether the substitution only differs in capitalization.
166 pub fn splice_lines(&self, sm: &SourceMap) -> Vec<(String, Vec<SubstitutionPart>, bool)> {
167 use rustc_span::{CharPos, Pos};
171 line_opt: Option<&Cow<'_, str>>,
173 hi_opt: Option<&Loc>,
175 let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
176 if let Some(line) = line_opt {
177 if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) {
178 let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi));
180 Some(hi) if hi > lo => buf.push_str(&line[lo..hi]),
182 None => buf.push_str(&line[lo..]),
185 if hi_opt.is_none() {
191 assert!(!self.substitutions.is_empty());
196 // Suggestions coming from macros can have malformed spans. This is a heavy
197 // handed approach to avoid ICEs by ignoring the suggestion outright.
198 let invalid = subst.parts.iter().any(|item| sm.is_valid_span(item.span).is_err());
200 debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
205 .filter_map(|mut substitution| {
206 // Assumption: all spans are in the same file, and all spans
207 // are disjoint. Sort in ascending order.
208 substitution.parts.sort_by_key(|part| part.span.lo());
210 // Find the bounding span.
211 let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?;
212 let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?;
213 let bounding_span = Span::with_root_ctxt(lo, hi);
214 // The different spans might belong to different contexts, if so ignore suggestion.
215 let lines = sm.span_to_lines(bounding_span).ok()?;
216 assert!(!lines.lines.is_empty() || bounding_span.is_dummy());
218 // We can't splice anything if the source is unavailable.
219 if !sm.ensure_source_file_source_present(lines.file.clone()) {
223 // To build up the result, we do this for each span:
224 // - push the line segment trailing the previous span
225 // (at the beginning a "phantom" span pointing at the start of the line)
226 // - push lines between the previous and current span (if any)
227 // - if the previous and current span are not on the same line
228 // push the line segment leading up to the current span
229 // - splice in the span substitution
231 // Finally push the trailing line segment of the last span
232 let sf = &lines.file;
233 let mut prev_hi = sm.lookup_char_pos(bounding_span.lo());
234 prev_hi.col = CharPos::from_usize(0);
236 lines.lines.get(0).and_then(|line0| sf.get_line(line0.line_index));
237 let mut buf = String::new();
239 for part in &substitution.parts {
240 let cur_lo = sm.lookup_char_pos(part.span.lo());
241 if prev_hi.line == cur_lo.line {
242 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
244 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
245 // push lines between the previous and current span (if any)
246 for idx in prev_hi.line..(cur_lo.line - 1) {
247 if let Some(line) = sf.get_line(idx) {
248 buf.push_str(line.as_ref());
252 if let Some(cur_line) = sf.get_line(cur_lo.line - 1) {
253 let end = match cur_line.char_indices().nth(cur_lo.col.to_usize()) {
255 None => cur_line.len(),
257 buf.push_str(&cur_line[..end]);
260 buf.push_str(&part.snippet);
261 prev_hi = sm.lookup_char_pos(part.span.hi());
262 prev_line = sf.get_line(prev_hi.line - 1);
264 let only_capitalization = is_case_difference(sm, &buf, bounding_span);
265 // if the replacement already ends with a newline, don't print the next line
266 if !buf.ends_with('\n') {
267 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
269 // remove trailing newlines
270 while buf.ends_with('\n') {
273 Some((buf, substitution.parts, only_capitalization))
279 pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
281 /// Signifies that the compiler died with an explicit call to `.bug`
282 /// or `.span_bug` rather than a failed assertion, etc.
283 #[derive(Copy, Clone, Debug)]
284 pub struct ExplicitBug;
286 impl fmt::Display for ExplicitBug {
287 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
288 write!(f, "parser internal bug")
292 impl error::Error for ExplicitBug {}
294 pub use diagnostic::{Diagnostic, DiagnosticId, DiagnosticStyledString, SubDiagnostic};
295 pub use diagnostic_builder::DiagnosticBuilder;
296 use std::backtrace::Backtrace;
298 /// A handler deals with errors and other compiler output.
299 /// Certain errors (fatal, bug, unimpl) may cause immediate exit,
300 /// others log errors for later reporting.
303 inner: Lock<HandlerInner>,
306 /// This inner struct exists to keep it all behind a single lock;
307 /// this is done to prevent possible deadlocks in a multi-threaded compiler,
308 /// as well as inconsistent state observation.
309 struct HandlerInner {
311 /// The number of errors that have been emitted, including duplicates.
313 /// This is not necessarily the count that's reported to the user once
314 /// compilation ends.
317 deduplicated_err_count: usize,
318 emitter: Box<dyn Emitter + sync::Send>,
319 delayed_span_bugs: Vec<Diagnostic>,
320 delayed_good_path_bugs: Vec<DelayedDiagnostic>,
322 /// This set contains the `DiagnosticId` of all emitted diagnostics to avoid
323 /// emitting the same diagnostic with extended help (`--teach`) twice, which
324 /// would be unnecessary repetition.
325 taught_diagnostics: FxHashSet<DiagnosticId>,
327 /// Used to suggest rustc --explain <error code>
328 emitted_diagnostic_codes: FxHashSet<DiagnosticId>,
330 /// This set contains a hash of every diagnostic that has been emitted by
331 /// this handler. These hashes is used to avoid emitting the same error
333 emitted_diagnostics: FxHashSet<u128>,
335 /// Stashed diagnostics emitted in one stage of the compiler that may be
336 /// stolen by other stages (e.g. to improve them and add more information).
337 /// The stashed diagnostics count towards the total error count.
338 /// When `.abort_if_errors()` is called, these are also emitted.
339 stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>,
341 /// The warning count, used for a recap upon finishing
342 deduplicated_warn_count: usize,
344 future_breakage_diagnostics: Vec<Diagnostic>,
346 /// If set to `true`, no warning or error will be emitted.
350 /// A key denoting where from a diagnostic was stashed.
351 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
356 fn default_track_diagnostic(_: &Diagnostic) {}
358 pub static TRACK_DIAGNOSTICS: AtomicRef<fn(&Diagnostic)> =
359 AtomicRef::new(&(default_track_diagnostic as fn(&_)));
361 #[derive(Copy, Clone, Default)]
362 pub struct HandlerFlags {
363 /// If false, warning-level lints are suppressed.
364 /// (rustc: see `--allow warnings` and `--cap-lints`)
365 pub can_emit_warnings: bool,
366 /// If true, error-level diagnostics are upgraded to bug-level.
367 /// (rustc: see `-Z treat-err-as-bug`)
368 pub treat_err_as_bug: Option<NonZeroUsize>,
369 /// If true, immediately emit diagnostics that would otherwise be buffered.
370 /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
371 pub dont_buffer_diagnostics: bool,
372 /// If true, immediately print bugs registered with `delay_span_bug`.
373 /// (rustc: see `-Z report-delayed-bugs`)
374 pub report_delayed_bugs: bool,
375 /// Show macro backtraces.
376 /// (rustc: see `-Z macro-backtrace`)
377 pub macro_backtrace: bool,
378 /// If true, identical diagnostics are reported only once.
379 pub deduplicate_diagnostics: bool,
382 impl Drop for HandlerInner {
384 self.emit_stashed_diagnostics();
386 if !self.has_errors() {
387 let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new());
388 self.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
391 if !self.has_any_message() {
392 let bugs = std::mem::replace(&mut self.delayed_good_path_bugs, Vec::new());
394 bugs.into_iter().map(DelayedDiagnostic::decorate).collect(),
395 "no warnings or errors encountered even though `delayed_good_path_bugs` issued",
402 pub fn with_tty_emitter(
403 color_config: ColorConfig,
404 can_emit_warnings: bool,
405 treat_err_as_bug: Option<NonZeroUsize>,
406 sm: Option<Lrc<SourceMap>>,
408 Self::with_tty_emitter_and_flags(
411 HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
415 pub fn with_tty_emitter_and_flags(
416 color_config: ColorConfig,
417 sm: Option<Lrc<SourceMap>>,
420 let emitter = Box::new(EmitterWriter::stderr(
426 flags.macro_backtrace,
428 Self::with_emitter_and_flags(emitter, flags)
432 can_emit_warnings: bool,
433 treat_err_as_bug: Option<NonZeroUsize>,
434 emitter: Box<dyn Emitter + sync::Send>,
436 Handler::with_emitter_and_flags(
438 HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
442 pub fn with_emitter_and_flags(
443 emitter: Box<dyn Emitter + sync::Send>,
448 inner: Lock::new(HandlerInner {
452 deduplicated_err_count: 0,
453 deduplicated_warn_count: 0,
455 delayed_span_bugs: Vec::new(),
456 delayed_good_path_bugs: Vec::new(),
457 taught_diagnostics: Default::default(),
458 emitted_diagnostic_codes: Default::default(),
459 emitted_diagnostics: Default::default(),
460 stashed_diagnostics: Default::default(),
461 future_breakage_diagnostics: Vec::new(),
467 pub fn with_disabled_diagnostic<T, F: FnOnce() -> T>(&self, f: F) -> T {
468 let prev = self.inner.borrow_mut().quiet;
469 self.inner.borrow_mut().quiet = true;
471 self.inner.borrow_mut().quiet = prev;
475 // This is here to not allow mutation of flags;
476 // as of this writing it's only used in tests in librustc_middle.
477 pub fn can_emit_warnings(&self) -> bool {
478 self.flags.can_emit_warnings
481 /// Resets the diagnostic error count as well as the cached emitted diagnostics.
483 /// NOTE: *do not* call this function from rustc. It is only meant to be called from external
484 /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
485 /// the overall count of emitted error diagnostics.
486 pub fn reset_err_count(&self) {
487 let mut inner = self.inner.borrow_mut();
489 inner.warn_count = 0;
490 inner.deduplicated_err_count = 0;
491 inner.deduplicated_warn_count = 0;
493 // actually free the underlying memory (which `clear` would not do)
494 inner.delayed_span_bugs = Default::default();
495 inner.delayed_good_path_bugs = Default::default();
496 inner.taught_diagnostics = Default::default();
497 inner.emitted_diagnostic_codes = Default::default();
498 inner.emitted_diagnostics = Default::default();
499 inner.stashed_diagnostics = Default::default();
502 /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
503 pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
504 let mut inner = self.inner.borrow_mut();
505 // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
506 // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
507 // See the PR for a discussion.
508 inner.stashed_diagnostics.insert((span, key), diag);
511 /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
512 pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_>> {
516 .remove(&(span, key))
517 .map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
520 /// Emit all stashed diagnostics.
521 pub fn emit_stashed_diagnostics(&self) {
522 self.inner.borrow_mut().emit_stashed_diagnostics();
525 /// Construct a dummy builder with `Level::Cancelled`.
527 /// Using this will neither report anything to the user (e.g. a warning),
528 /// nor will compilation cancel as a result.
529 pub fn struct_dummy(&self) -> DiagnosticBuilder<'_> {
530 DiagnosticBuilder::new(self, Level::Cancelled, "")
533 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
535 /// The builder will be canceled if warnings cannot be emitted.
536 pub fn struct_span_warn(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
537 let mut result = self.struct_warn(msg);
538 result.set_span(span);
542 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
544 /// This will "force" the warning meaning it will not be canceled even
545 /// if warnings cannot be emitted.
546 pub fn struct_span_force_warn(
548 span: impl Into<MultiSpan>,
550 ) -> DiagnosticBuilder<'_> {
551 let mut result = self.struct_force_warn(msg);
552 result.set_span(span);
556 /// Construct a builder at the `Allow` level at the given `span` and with the `msg`.
557 pub fn struct_span_allow(
559 span: impl Into<MultiSpan>,
561 ) -> DiagnosticBuilder<'_> {
562 let mut result = self.struct_allow(msg);
563 result.set_span(span);
567 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
568 /// Also include a code.
569 pub fn struct_span_warn_with_code(
571 span: impl Into<MultiSpan>,
574 ) -> DiagnosticBuilder<'_> {
575 let mut result = self.struct_span_warn(span, msg);
580 /// Construct a builder at the `Warning` level with the `msg`.
582 /// The builder will be canceled if warnings cannot be emitted.
583 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
584 let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
585 if !self.flags.can_emit_warnings {
591 /// Construct a builder at the `Warning` level with the `msg`.
593 /// This will "force" a warning meaning it will not be canceled even
594 /// if warnings cannot be emitted.
595 pub fn struct_force_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
596 DiagnosticBuilder::new(self, Level::Warning, msg)
599 /// Construct a builder at the `Allow` level with the `msg`.
600 pub fn struct_allow(&self, msg: &str) -> DiagnosticBuilder<'_> {
601 DiagnosticBuilder::new(self, Level::Allow, msg)
604 /// Construct a builder at the `Error` level at the given `span` and with the `msg`.
605 pub fn struct_span_err(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
606 let mut result = self.struct_err(msg);
607 result.set_span(span);
611 /// Construct a builder at the `Error` level at the given `span`, with the `msg`, and `code`.
612 pub fn struct_span_err_with_code(
614 span: impl Into<MultiSpan>,
617 ) -> DiagnosticBuilder<'_> {
618 let mut result = self.struct_span_err(span, msg);
623 /// Construct a builder at the `Error` level with the `msg`.
624 // FIXME: This method should be removed (every error should have an associated error code).
625 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
626 DiagnosticBuilder::new(self, Level::Error, msg)
629 /// Construct a builder at the `Error` level with the `msg` and the `code`.
630 pub fn struct_err_with_code(&self, msg: &str, code: DiagnosticId) -> DiagnosticBuilder<'_> {
631 let mut result = self.struct_err(msg);
636 /// Construct a builder at the `Fatal` level at the given `span` and with the `msg`.
637 pub fn struct_span_fatal(
639 span: impl Into<MultiSpan>,
641 ) -> DiagnosticBuilder<'_> {
642 let mut result = self.struct_fatal(msg);
643 result.set_span(span);
647 /// Construct a builder at the `Fatal` level at the given `span`, with the `msg`, and `code`.
648 pub fn struct_span_fatal_with_code(
650 span: impl Into<MultiSpan>,
653 ) -> DiagnosticBuilder<'_> {
654 let mut result = self.struct_span_fatal(span, msg);
659 /// Construct a builder at the `Error` level with the `msg`.
660 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
661 DiagnosticBuilder::new(self, Level::Fatal, msg)
664 /// Construct a builder at the `Help` level with the `msg`.
665 pub fn struct_help(&self, msg: &str) -> DiagnosticBuilder<'_> {
666 DiagnosticBuilder::new(self, Level::Help, msg)
669 /// Construct a builder at the `Note` level with the `msg`.
670 pub fn struct_note_without_error(&self, msg: &str) -> DiagnosticBuilder<'_> {
671 DiagnosticBuilder::new(self, Level::Note, msg)
674 pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: &str) -> ! {
675 self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span);
679 pub fn span_fatal_with_code(
681 span: impl Into<MultiSpan>,
685 self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span);
689 pub fn span_err(&self, span: impl Into<MultiSpan>, msg: &str) {
690 self.emit_diag_at_span(Diagnostic::new(Error, msg), span);
693 pub fn span_err_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
694 self.emit_diag_at_span(Diagnostic::new_with_code(Error, Some(code), msg), span);
697 pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: &str) {
698 self.emit_diag_at_span(Diagnostic::new(Warning, msg), span);
701 pub fn span_warn_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
702 self.emit_diag_at_span(Diagnostic::new_with_code(Warning, Some(code), msg), span);
705 pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: &str) -> ! {
706 self.inner.borrow_mut().span_bug(span, msg)
710 pub fn delay_span_bug(&self, span: impl Into<MultiSpan>, msg: &str) {
711 self.inner.borrow_mut().delay_span_bug(span, msg)
714 pub fn delay_good_path_bug(&self, msg: &str) {
715 self.inner.borrow_mut().delay_good_path_bug(msg)
718 pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: &str) {
719 self.emit_diag_at_span(Diagnostic::new(Bug, msg), span);
722 pub fn span_note_without_error(&self, span: impl Into<MultiSpan>, msg: &str) {
723 self.emit_diag_at_span(Diagnostic::new(Note, msg), span);
726 pub fn span_note_diag(&self, span: Span, msg: &str) -> DiagnosticBuilder<'_> {
727 let mut db = DiagnosticBuilder::new(self, Note, msg);
732 // NOTE: intentionally doesn't raise an error so rustc_codegen_ssa only reports fatal errors in the main thread
733 pub fn fatal(&self, msg: &str) -> FatalError {
734 self.inner.borrow_mut().fatal(msg)
737 pub fn err(&self, msg: &str) {
738 self.inner.borrow_mut().err(msg);
741 pub fn warn(&self, msg: &str) {
742 let mut db = DiagnosticBuilder::new(self, Warning, msg);
746 pub fn note_without_error(&self, msg: &str) {
747 DiagnosticBuilder::new(self, Note, msg).emit();
750 pub fn bug(&self, msg: &str) -> ! {
751 self.inner.borrow_mut().bug(msg)
755 pub fn err_count(&self) -> usize {
756 self.inner.borrow().err_count()
759 pub fn has_errors(&self) -> bool {
760 self.inner.borrow().has_errors()
762 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
763 self.inner.borrow().has_errors_or_delayed_span_bugs()
766 pub fn print_error_count(&self, registry: &Registry) {
767 self.inner.borrow_mut().print_error_count(registry)
770 pub fn take_future_breakage_diagnostics(&self) -> Vec<Diagnostic> {
771 std::mem::take(&mut self.inner.borrow_mut().future_breakage_diagnostics)
774 pub fn abort_if_errors(&self) {
775 self.inner.borrow_mut().abort_if_errors()
778 /// `true` if we haven't taught a diagnostic with this code already.
779 /// The caller must then teach the user about such a diagnostic.
781 /// Used to suppress emitting the same error multiple times with extended explanation when
782 /// calling `-Zteach`.
783 pub fn must_teach(&self, code: &DiagnosticId) -> bool {
784 self.inner.borrow_mut().must_teach(code)
787 pub fn force_print_diagnostic(&self, db: Diagnostic) {
788 self.inner.borrow_mut().force_print_diagnostic(db)
791 pub fn emit_diagnostic(&self, diagnostic: &Diagnostic) {
792 self.inner.borrow_mut().emit_diagnostic(diagnostic)
795 fn emit_diag_at_span(&self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
796 let mut inner = self.inner.borrow_mut();
797 inner.emit_diagnostic(diag.set_span(sp));
800 pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
801 self.inner.borrow_mut().emit_artifact_notification(path, artifact_type)
804 pub fn emit_future_breakage_report(&self, diags: Vec<Diagnostic>) {
805 self.inner.borrow_mut().emitter.emit_future_breakage_report(diags)
808 pub fn emit_unused_externs(&self, lint_level: &str, unused_externs: &[&str]) {
809 self.inner.borrow_mut().emit_unused_externs(lint_level, unused_externs)
812 pub fn delay_as_bug(&self, diagnostic: Diagnostic) {
813 self.inner.borrow_mut().delay_as_bug(diagnostic)
818 fn must_teach(&mut self, code: &DiagnosticId) -> bool {
819 self.taught_diagnostics.insert(code.clone())
822 fn force_print_diagnostic(&mut self, db: Diagnostic) {
823 self.emitter.emit_diagnostic(&db);
826 /// Emit all stashed diagnostics.
827 fn emit_stashed_diagnostics(&mut self) {
828 let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>();
829 diags.iter().for_each(|diag| self.emit_diagnostic(diag));
832 fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) {
833 if diagnostic.cancelled() || self.quiet {
837 if diagnostic.has_future_breakage() {
838 self.future_breakage_diagnostics.push(diagnostic.clone());
841 if diagnostic.level == Warning
842 && !self.flags.can_emit_warnings
843 && !diagnostic.is_force_warn()
845 if diagnostic.has_future_breakage() {
846 (*TRACK_DIAGNOSTICS)(diagnostic);
851 (*TRACK_DIAGNOSTICS)(diagnostic);
853 if diagnostic.level == Allow {
857 if let Some(ref code) = diagnostic.code {
858 self.emitted_diagnostic_codes.insert(code.clone());
861 let already_emitted = |this: &mut Self| {
862 let mut hasher = StableHasher::new();
863 diagnostic.hash(&mut hasher);
864 let diagnostic_hash = hasher.finish();
865 !this.emitted_diagnostics.insert(diagnostic_hash)
868 // Only emit the diagnostic if we've been asked to deduplicate and
869 // haven't already emitted an equivalent diagnostic.
870 if !(self.flags.deduplicate_diagnostics && already_emitted(self)) {
871 self.emitter.emit_diagnostic(diagnostic);
872 if diagnostic.is_error() {
873 self.deduplicated_err_count += 1;
874 } else if diagnostic.level == Warning {
875 self.deduplicated_warn_count += 1;
878 if diagnostic.is_error() {
879 self.bump_err_count();
881 self.bump_warn_count();
885 fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) {
886 self.emitter.emit_artifact_notification(path, artifact_type);
889 fn emit_unused_externs(&mut self, lint_level: &str, unused_externs: &[&str]) {
890 self.emitter.emit_unused_externs(lint_level, unused_externs);
893 fn treat_err_as_bug(&self) -> bool {
894 self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() >= c.get())
897 fn print_error_count(&mut self, registry: &Registry) {
898 self.emit_stashed_diagnostics();
900 let warnings = match self.deduplicated_warn_count {
902 1 => "1 warning emitted".to_string(),
903 count => format!("{} warnings emitted", count),
905 let errors = match self.deduplicated_err_count {
907 1 => "aborting due to previous error".to_string(),
908 count => format!("aborting due to {} previous errors", count),
910 if self.treat_err_as_bug() {
914 match (errors.len(), warnings.len()) {
916 (0, _) => self.emitter.emit_diagnostic(&Diagnostic::new(Level::Warning, &warnings)),
918 let _ = self.fatal(&errors);
921 let _ = self.fatal(&format!("{}; {}", &errors, &warnings));
925 let can_show_explain = self.emitter.should_show_explain();
926 let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty();
927 if can_show_explain && are_there_diagnostics {
928 let mut error_codes = self
929 .emitted_diagnostic_codes
931 .filter_map(|x| match &x {
932 DiagnosticId::Error(s) => {
933 if let Ok(Some(_explanation)) = registry.try_find_description(s) {
941 .collect::<Vec<_>>();
942 if !error_codes.is_empty() {
944 if error_codes.len() > 1 {
945 let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
946 self.failure(&format!(
947 "Some errors have detailed explanations: {}{}",
948 error_codes[..limit].join(", "),
949 if error_codes.len() > 9 { "..." } else { "." }
951 self.failure(&format!(
952 "For more information about an error, try \
953 `rustc --explain {}`.",
957 self.failure(&format!(
958 "For more information about this error, try \
959 `rustc --explain {}`.",
968 fn err_count(&self) -> usize {
969 self.err_count + self.stashed_diagnostics.len()
972 fn has_errors(&self) -> bool {
975 fn has_errors_or_delayed_span_bugs(&self) -> bool {
976 self.has_errors() || !self.delayed_span_bugs.is_empty()
978 fn has_any_message(&self) -> bool {
979 self.err_count() > 0 || self.warn_count > 0
982 fn abort_if_errors(&mut self) {
983 self.emit_stashed_diagnostics();
985 if self.has_errors() {
990 fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) -> ! {
991 self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp);
992 panic::panic_any(ExplicitBug);
995 fn emit_diag_at_span(&mut self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
996 self.emit_diagnostic(diag.set_span(sp));
1000 fn delay_span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) {
1001 // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
1002 // incrementing `err_count` by one, so we need to +1 the comparing.
1003 // FIXME: Would be nice to increment err_count in a more coherent way.
1004 if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c.get()) {
1005 // FIXME: don't abort here if report_delayed_bugs is off
1006 self.span_bug(sp, msg);
1008 let mut diagnostic = Diagnostic::new(Level::Bug, msg);
1009 diagnostic.set_span(sp.into());
1010 diagnostic.note(&format!("delayed at {}", std::panic::Location::caller()));
1011 self.delay_as_bug(diagnostic)
1014 fn delay_good_path_bug(&mut self, msg: &str) {
1015 let diagnostic = Diagnostic::new(Level::Bug, msg);
1016 if self.flags.report_delayed_bugs {
1017 self.emit_diagnostic(&diagnostic);
1019 let backtrace = std::backtrace::Backtrace::force_capture();
1020 self.delayed_good_path_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace));
1023 fn failure(&mut self, msg: &str) {
1024 self.emit_diagnostic(&Diagnostic::new(FailureNote, msg));
1027 fn fatal(&mut self, msg: &str) -> FatalError {
1028 self.emit_error(Fatal, msg);
1032 fn err(&mut self, msg: &str) {
1033 self.emit_error(Error, msg);
1036 /// Emit an error; level should be `Error` or `Fatal`.
1037 fn emit_error(&mut self, level: Level, msg: &str) {
1038 if self.treat_err_as_bug() {
1041 self.emit_diagnostic(&Diagnostic::new(level, msg));
1044 fn bug(&mut self, msg: &str) -> ! {
1045 self.emit_diagnostic(&Diagnostic::new(Bug, msg));
1046 panic::panic_any(ExplicitBug);
1049 fn delay_as_bug(&mut self, diagnostic: Diagnostic) {
1053 if self.flags.report_delayed_bugs {
1054 self.emit_diagnostic(&diagnostic);
1056 self.delayed_span_bugs.push(diagnostic);
1059 fn flush_delayed(&mut self, bugs: Vec<Diagnostic>, explanation: &str) {
1060 let has_bugs = !bugs.is_empty();
1062 self.emit_diagnostic(&bug);
1065 panic!("{}", explanation);
1069 fn bump_err_count(&mut self) {
1070 self.err_count += 1;
1071 self.panic_if_treat_err_as_bug();
1074 fn bump_warn_count(&mut self) {
1075 self.warn_count += 1;
1078 fn panic_if_treat_err_as_bug(&self) {
1079 if self.treat_err_as_bug() {
1080 match (self.err_count(), self.flags.treat_err_as_bug.map(|c| c.get()).unwrap_or(0)) {
1081 (1, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
1082 (0, _) | (1, _) => {}
1083 (count, as_bug) => panic!(
1084 "aborting after {} errors due to `-Z treat-err-as-bug={}`",
1092 struct DelayedDiagnostic {
1097 impl DelayedDiagnostic {
1098 fn with_backtrace(diagnostic: Diagnostic, backtrace: Backtrace) -> Self {
1099 DelayedDiagnostic { inner: diagnostic, note: backtrace }
1102 fn decorate(mut self) -> Diagnostic {
1103 self.inner.note(&format!("delayed at {}", self.note));
1108 #[derive(Copy, PartialEq, Clone, Hash, Debug, Encodable, Decodable)]
1121 impl fmt::Display for Level {
1122 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1123 self.to_str().fmt(f)
1128 fn color(self) -> ColorSpec {
1129 let mut spec = ColorSpec::new();
1131 Bug | Fatal | Error => {
1132 spec.set_fg(Some(Color::Red)).set_intense(true);
1135 spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows));
1138 spec.set_fg(Some(Color::Green)).set_intense(true);
1141 spec.set_fg(Some(Color::Cyan)).set_intense(true);
1144 Allow | Cancelled => unreachable!(),
1149 pub fn to_str(self) -> &'static str {
1151 Bug => "error: internal compiler error",
1152 Fatal | Error => "error",
1153 Warning => "warning",
1156 FailureNote => "failure-note",
1157 Cancelled => panic!("Shouldn't call on cancelled error"),
1158 Allow => panic!("Shouldn't call on allowed error"),
1162 pub fn is_failure_note(&self) -> bool {
1163 matches!(*self, FailureNote)
1167 pub fn add_elided_lifetime_in_path_suggestion(
1168 source_map: &SourceMap,
1169 db: &mut DiagnosticBuilder<'_>,
1172 incl_angl_brckt: bool,
1173 insertion_span: Span,
1176 let (replace_span, suggestion) = if incl_angl_brckt {
1177 (insertion_span, anon_lts)
1179 // When possible, prefer a suggestion that replaces the whole
1180 // `Path<T>` expression with `Path<'_, T>`, rather than inserting `'_, `
1181 // at a point (which makes for an ugly/confusing label)
1182 if let Ok(snippet) = source_map.span_to_snippet(path_span) {
1183 // But our spans can get out of whack due to macros; if the place we think
1184 // we want to insert `'_` isn't even within the path expression's span, we
1185 // should bail out of making any suggestion rather than panicking on a
1186 // subtract-with-overflow or string-slice-out-out-bounds (!)
1187 // FIXME: can we do better?
1188 if insertion_span.lo().0 < path_span.lo().0 {
1191 let insertion_index = (insertion_span.lo().0 - path_span.lo().0) as usize;
1192 if insertion_index > snippet.len() {
1195 let (before, after) = snippet.split_at(insertion_index);
1196 (path_span, format!("{}{}{}", before, anon_lts, after))
1198 (insertion_span, anon_lts)
1203 &format!("indicate the anonymous lifetime{}", pluralize!(n)),
1205 Applicability::MachineApplicable,
1209 // Useful type to use with `Result<>` indicate that an error has already
1210 // been reported to the user, so no need to continue checking.
1211 #[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq)]
1212 pub struct ErrorReported;
1214 rustc_data_structures::impl_stable_hash_via_hash!(ErrorReported);