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;
17 use tracing::{debug, info};
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 /// Used to translate between `Span`s and byte positions within a single output line in highlighted
164 /// code of structured suggestions.
165 #[derive(Debug, Clone, Copy)]
166 pub struct SubstitutionHighlight {
171 impl SubstitutionPart {
172 pub fn is_addition(&self, sm: &SourceMap) -> bool {
173 !self.snippet.is_empty()
175 .span_to_snippet(self.span)
176 .map_or(self.span.is_empty(), |snippet| snippet.trim().is_empty())
179 pub fn is_deletion(&self) -> bool {
180 self.snippet.trim().is_empty()
183 pub fn is_replacement(&self, sm: &SourceMap) -> bool {
184 !self.snippet.is_empty()
186 .span_to_snippet(self.span)
187 .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty())
191 impl CodeSuggestion {
192 /// Returns the assembled code suggestions, whether they should be shown with an underline
193 /// and whether the substitution only differs in capitalization.
197 ) -> Vec<(String, Vec<SubstitutionPart>, Vec<Vec<SubstitutionHighlight>>, bool)> {
198 // For the `Vec<Vec<SubstitutionHighlight>>` value, the first level of the vector
199 // corresponds to the output snippet's lines, while the second level corresponds to the
200 // substrings within that line that should be highlighted.
202 use rustc_span::{CharPos, Pos};
204 /// Append to a buffer the remainder of the line of existing source code, and return the
205 /// count of lines that have been added for accurate highlighting.
208 line_opt: Option<&Cow<'_, str>>,
210 hi_opt: Option<&Loc>,
212 let mut line_count = 0;
213 let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
214 if let Some(line) = line_opt {
215 if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) {
216 let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi));
218 Some(hi) if hi > lo => {
219 line_count = line[lo..hi].matches('\n').count();
220 buf.push_str(&line[lo..hi])
224 line_count = line[lo..].matches('\n').count();
225 buf.push_str(&line[lo..])
229 if hi_opt.is_none() {
236 assert!(!self.substitutions.is_empty());
241 // Suggestions coming from macros can have malformed spans. This is a heavy
242 // handed approach to avoid ICEs by ignoring the suggestion outright.
243 let invalid = subst.parts.iter().any(|item| sm.is_valid_span(item.span).is_err());
245 debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
250 .filter_map(|mut substitution| {
251 // Assumption: all spans are in the same file, and all spans
252 // are disjoint. Sort in ascending order.
253 substitution.parts.sort_by_key(|part| part.span.lo());
255 // Find the bounding span.
256 let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?;
257 let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?;
258 let bounding_span = Span::with_root_ctxt(lo, hi);
259 // The different spans might belong to different contexts, if so ignore suggestion.
260 let lines = sm.span_to_lines(bounding_span).ok()?;
261 assert!(!lines.lines.is_empty() || bounding_span.is_dummy());
263 // We can't splice anything if the source is unavailable.
264 if !sm.ensure_source_file_source_present(lines.file.clone()) {
268 let mut highlights = vec![];
269 // To build up the result, we do this for each span:
270 // - push the line segment trailing the previous span
271 // (at the beginning a "phantom" span pointing at the start of the line)
272 // - push lines between the previous and current span (if any)
273 // - if the previous and current span are not on the same line
274 // push the line segment leading up to the current span
275 // - splice in the span substitution
277 // Finally push the trailing line segment of the last span
278 let sf = &lines.file;
279 let mut prev_hi = sm.lookup_char_pos(bounding_span.lo());
280 prev_hi.col = CharPos::from_usize(0);
282 lines.lines.get(0).and_then(|line0| sf.get_line(line0.line_index));
283 let mut buf = String::new();
285 let mut line_highlight = vec![];
286 // We need to keep track of the difference between the existing code and the added
287 // or deleted code in order to point at the correct column *after* substitution.
289 for part in &substitution.parts {
290 let cur_lo = sm.lookup_char_pos(part.span.lo());
291 if prev_hi.line == cur_lo.line {
293 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
295 highlights.push(std::mem::take(&mut line_highlight));
300 highlights.push(std::mem::take(&mut line_highlight));
301 let mut count = push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
303 highlights.push(std::mem::take(&mut line_highlight));
307 // push lines between the previous and current span (if any)
308 for idx in prev_hi.line..(cur_lo.line - 1) {
309 if let Some(line) = sf.get_line(idx) {
310 buf.push_str(line.as_ref());
312 highlights.push(std::mem::take(&mut line_highlight));
316 if let Some(cur_line) = sf.get_line(cur_lo.line - 1) {
317 let end = match cur_line.char_indices().nth(cur_lo.col.to_usize()) {
319 None => cur_line.len(),
321 buf.push_str(&cur_line[..end]);
324 // Add a whole line highlight per line in the snippet.
325 let len = part.snippet.split('\n').next().unwrap_or(&part.snippet).len();
326 line_highlight.push(SubstitutionHighlight {
327 start: (cur_lo.col.0 as isize + acc) as usize,
328 end: (cur_lo.col.0 as isize + acc + len as isize) as usize,
330 buf.push_str(&part.snippet);
331 prev_hi = sm.lookup_char_pos(part.span.hi());
332 if prev_hi.line == cur_lo.line {
333 acc += len as isize - (prev_hi.col.0 - cur_lo.col.0) as isize;
335 prev_line = sf.get_line(prev_hi.line - 1);
336 for line in part.snippet.split('\n').skip(1) {
338 highlights.push(std::mem::take(&mut line_highlight));
339 line_highlight.push(SubstitutionHighlight { start: 0, end: line.len() });
342 highlights.push(std::mem::take(&mut line_highlight));
343 let only_capitalization = is_case_difference(sm, &buf, bounding_span);
344 // if the replacement already ends with a newline, don't print the next line
345 if !buf.ends_with('\n') {
346 push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
348 // remove trailing newlines
349 while buf.ends_with('\n') {
352 info!(?buf, ?highlights);
353 Some((buf, substitution.parts, highlights, only_capitalization))
359 pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
361 /// Signifies that the compiler died with an explicit call to `.bug`
362 /// or `.span_bug` rather than a failed assertion, etc.
363 #[derive(Copy, Clone, Debug)]
364 pub struct ExplicitBug;
366 impl fmt::Display for ExplicitBug {
367 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
368 write!(f, "parser internal bug")
372 impl error::Error for ExplicitBug {}
374 pub use diagnostic::{Diagnostic, DiagnosticId, DiagnosticStyledString, SubDiagnostic};
375 pub use diagnostic_builder::DiagnosticBuilder;
376 use std::backtrace::Backtrace;
378 /// A handler deals with errors and other compiler output.
379 /// Certain errors (fatal, bug, unimpl) may cause immediate exit,
380 /// others log errors for later reporting.
383 inner: Lock<HandlerInner>,
386 /// This inner struct exists to keep it all behind a single lock;
387 /// this is done to prevent possible deadlocks in a multi-threaded compiler,
388 /// as well as inconsistent state observation.
389 struct HandlerInner {
391 /// The number of errors that have been emitted, including duplicates.
393 /// This is not necessarily the count that's reported to the user once
394 /// compilation ends.
397 deduplicated_err_count: usize,
398 emitter: Box<dyn Emitter + sync::Send>,
399 delayed_span_bugs: Vec<Diagnostic>,
400 delayed_good_path_bugs: Vec<DelayedDiagnostic>,
402 /// This set contains the `DiagnosticId` of all emitted diagnostics to avoid
403 /// emitting the same diagnostic with extended help (`--teach`) twice, which
404 /// would be unnecessary repetition.
405 taught_diagnostics: FxHashSet<DiagnosticId>,
407 /// Used to suggest rustc --explain <error code>
408 emitted_diagnostic_codes: FxHashSet<DiagnosticId>,
410 /// This set contains a hash of every diagnostic that has been emitted by
411 /// this handler. These hashes is used to avoid emitting the same error
413 emitted_diagnostics: FxHashSet<u128>,
415 /// Stashed diagnostics emitted in one stage of the compiler that may be
416 /// stolen by other stages (e.g. to improve them and add more information).
417 /// The stashed diagnostics count towards the total error count.
418 /// When `.abort_if_errors()` is called, these are also emitted.
419 stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>,
421 /// The warning count, used for a recap upon finishing
422 deduplicated_warn_count: usize,
424 future_breakage_diagnostics: Vec<Diagnostic>,
426 /// If set to `true`, no warning or error will be emitted.
430 /// A key denoting where from a diagnostic was stashed.
431 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
436 fn default_track_diagnostic(_: &Diagnostic) {}
438 pub static TRACK_DIAGNOSTICS: AtomicRef<fn(&Diagnostic)> =
439 AtomicRef::new(&(default_track_diagnostic as fn(&_)));
441 #[derive(Copy, Clone, Default)]
442 pub struct HandlerFlags {
443 /// If false, warning-level lints are suppressed.
444 /// (rustc: see `--allow warnings` and `--cap-lints`)
445 pub can_emit_warnings: bool,
446 /// If true, error-level diagnostics are upgraded to bug-level.
447 /// (rustc: see `-Z treat-err-as-bug`)
448 pub treat_err_as_bug: Option<NonZeroUsize>,
449 /// If true, immediately emit diagnostics that would otherwise be buffered.
450 /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
451 pub dont_buffer_diagnostics: bool,
452 /// If true, immediately print bugs registered with `delay_span_bug`.
453 /// (rustc: see `-Z report-delayed-bugs`)
454 pub report_delayed_bugs: bool,
455 /// Show macro backtraces.
456 /// (rustc: see `-Z macro-backtrace`)
457 pub macro_backtrace: bool,
458 /// If true, identical diagnostics are reported only once.
459 pub deduplicate_diagnostics: bool,
462 impl Drop for HandlerInner {
464 self.emit_stashed_diagnostics();
466 if !self.has_errors() {
467 let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new());
468 self.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
471 if !self.has_any_message() {
472 let bugs = std::mem::replace(&mut self.delayed_good_path_bugs, Vec::new());
474 bugs.into_iter().map(DelayedDiagnostic::decorate).collect(),
475 "no warnings or errors encountered even though `delayed_good_path_bugs` issued",
482 pub fn with_tty_emitter(
483 color_config: ColorConfig,
484 can_emit_warnings: bool,
485 treat_err_as_bug: Option<NonZeroUsize>,
486 sm: Option<Lrc<SourceMap>>,
488 Self::with_tty_emitter_and_flags(
491 HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
495 pub fn with_tty_emitter_and_flags(
496 color_config: ColorConfig,
497 sm: Option<Lrc<SourceMap>>,
500 let emitter = Box::new(EmitterWriter::stderr(
506 flags.macro_backtrace,
508 Self::with_emitter_and_flags(emitter, flags)
512 can_emit_warnings: bool,
513 treat_err_as_bug: Option<NonZeroUsize>,
514 emitter: Box<dyn Emitter + sync::Send>,
516 Handler::with_emitter_and_flags(
518 HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
522 pub fn with_emitter_and_flags(
523 emitter: Box<dyn Emitter + sync::Send>,
528 inner: Lock::new(HandlerInner {
532 deduplicated_err_count: 0,
533 deduplicated_warn_count: 0,
535 delayed_span_bugs: Vec::new(),
536 delayed_good_path_bugs: Vec::new(),
537 taught_diagnostics: Default::default(),
538 emitted_diagnostic_codes: Default::default(),
539 emitted_diagnostics: Default::default(),
540 stashed_diagnostics: Default::default(),
541 future_breakage_diagnostics: Vec::new(),
547 pub fn with_disabled_diagnostic<T, F: FnOnce() -> T>(&self, f: F) -> T {
548 let prev = self.inner.borrow_mut().quiet;
549 self.inner.borrow_mut().quiet = true;
551 self.inner.borrow_mut().quiet = prev;
555 // This is here to not allow mutation of flags;
556 // as of this writing it's only used in tests in librustc_middle.
557 pub fn can_emit_warnings(&self) -> bool {
558 self.flags.can_emit_warnings
561 /// Resets the diagnostic error count as well as the cached emitted diagnostics.
563 /// NOTE: *do not* call this function from rustc. It is only meant to be called from external
564 /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
565 /// the overall count of emitted error diagnostics.
566 pub fn reset_err_count(&self) {
567 let mut inner = self.inner.borrow_mut();
569 inner.warn_count = 0;
570 inner.deduplicated_err_count = 0;
571 inner.deduplicated_warn_count = 0;
573 // actually free the underlying memory (which `clear` would not do)
574 inner.delayed_span_bugs = Default::default();
575 inner.delayed_good_path_bugs = Default::default();
576 inner.taught_diagnostics = Default::default();
577 inner.emitted_diagnostic_codes = Default::default();
578 inner.emitted_diagnostics = Default::default();
579 inner.stashed_diagnostics = Default::default();
582 /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
583 pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
584 let mut inner = self.inner.borrow_mut();
585 // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
586 // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
587 // See the PR for a discussion.
588 inner.stashed_diagnostics.insert((span, key), diag);
591 /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
592 pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_>> {
596 .remove(&(span, key))
597 .map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
600 /// Emit all stashed diagnostics.
601 pub fn emit_stashed_diagnostics(&self) {
602 self.inner.borrow_mut().emit_stashed_diagnostics();
605 /// Construct a dummy builder with `Level::Cancelled`.
607 /// Using this will neither report anything to the user (e.g. a warning),
608 /// nor will compilation cancel as a result.
609 pub fn struct_dummy(&self) -> DiagnosticBuilder<'_> {
610 DiagnosticBuilder::new(self, Level::Cancelled, "")
613 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
615 /// The builder will be canceled if warnings cannot be emitted.
616 pub fn struct_span_warn(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
617 let mut result = self.struct_warn(msg);
618 result.set_span(span);
622 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
624 /// This will "force" the warning meaning it will not be canceled even
625 /// if warnings cannot be emitted.
626 pub fn struct_span_force_warn(
628 span: impl Into<MultiSpan>,
630 ) -> DiagnosticBuilder<'_> {
631 let mut result = self.struct_force_warn(msg);
632 result.set_span(span);
636 /// Construct a builder at the `Allow` level at the given `span` and with the `msg`.
637 pub fn struct_span_allow(
639 span: impl Into<MultiSpan>,
641 ) -> DiagnosticBuilder<'_> {
642 let mut result = self.struct_allow(msg);
643 result.set_span(span);
647 /// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
648 /// Also include a code.
649 pub fn struct_span_warn_with_code(
651 span: impl Into<MultiSpan>,
654 ) -> DiagnosticBuilder<'_> {
655 let mut result = self.struct_span_warn(span, msg);
660 /// Construct a builder at the `Warning` level with the `msg`.
662 /// The builder will be canceled if warnings cannot be emitted.
663 pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
664 let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
665 if !self.flags.can_emit_warnings {
671 /// Construct a builder at the `Warning` level with the `msg`.
673 /// This will "force" a warning meaning it will not be canceled even
674 /// if warnings cannot be emitted.
675 pub fn struct_force_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
676 DiagnosticBuilder::new(self, Level::Warning, msg)
679 /// Construct a builder at the `Allow` level with the `msg`.
680 pub fn struct_allow(&self, msg: &str) -> DiagnosticBuilder<'_> {
681 DiagnosticBuilder::new(self, Level::Allow, msg)
684 /// Construct a builder at the `Error` level at the given `span` and with the `msg`.
685 pub fn struct_span_err(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
686 let mut result = self.struct_err(msg);
687 result.set_span(span);
691 /// Construct a builder at the `Error` level at the given `span`, with the `msg`, and `code`.
692 pub fn struct_span_err_with_code(
694 span: impl Into<MultiSpan>,
697 ) -> DiagnosticBuilder<'_> {
698 let mut result = self.struct_span_err(span, msg);
703 /// Construct a builder at the `Error` level with the `msg`.
704 // FIXME: This method should be removed (every error should have an associated error code).
705 pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
706 DiagnosticBuilder::new(self, Level::Error, msg)
709 /// Construct a builder at the `Error` level with the `msg` and the `code`.
710 pub fn struct_err_with_code(&self, msg: &str, code: DiagnosticId) -> DiagnosticBuilder<'_> {
711 let mut result = self.struct_err(msg);
716 /// Construct a builder at the `Fatal` level at the given `span` and with the `msg`.
717 pub fn struct_span_fatal(
719 span: impl Into<MultiSpan>,
721 ) -> DiagnosticBuilder<'_> {
722 let mut result = self.struct_fatal(msg);
723 result.set_span(span);
727 /// Construct a builder at the `Fatal` level at the given `span`, with the `msg`, and `code`.
728 pub fn struct_span_fatal_with_code(
730 span: impl Into<MultiSpan>,
733 ) -> DiagnosticBuilder<'_> {
734 let mut result = self.struct_span_fatal(span, msg);
739 /// Construct a builder at the `Error` level with the `msg`.
740 pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
741 DiagnosticBuilder::new(self, Level::Fatal, msg)
744 /// Construct a builder at the `Help` level with the `msg`.
745 pub fn struct_help(&self, msg: &str) -> DiagnosticBuilder<'_> {
746 DiagnosticBuilder::new(self, Level::Help, msg)
749 /// Construct a builder at the `Note` level with the `msg`.
750 pub fn struct_note_without_error(&self, msg: &str) -> DiagnosticBuilder<'_> {
751 DiagnosticBuilder::new(self, Level::Note, msg)
754 pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: &str) -> ! {
755 self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span);
759 pub fn span_fatal_with_code(
761 span: impl Into<MultiSpan>,
765 self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span);
769 pub fn span_err(&self, span: impl Into<MultiSpan>, msg: &str) {
770 self.emit_diag_at_span(Diagnostic::new(Error, msg), span);
773 pub fn span_err_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
774 self.emit_diag_at_span(Diagnostic::new_with_code(Error, Some(code), msg), span);
777 pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: &str) {
778 self.emit_diag_at_span(Diagnostic::new(Warning, msg), span);
781 pub fn span_warn_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
782 self.emit_diag_at_span(Diagnostic::new_with_code(Warning, Some(code), msg), span);
785 pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: &str) -> ! {
786 self.inner.borrow_mut().span_bug(span, msg)
790 pub fn delay_span_bug(&self, span: impl Into<MultiSpan>, msg: &str) {
791 self.inner.borrow_mut().delay_span_bug(span, msg)
794 pub fn delay_good_path_bug(&self, msg: &str) {
795 self.inner.borrow_mut().delay_good_path_bug(msg)
798 pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: &str) {
799 self.emit_diag_at_span(Diagnostic::new(Bug, msg), span);
802 pub fn span_note_without_error(&self, span: impl Into<MultiSpan>, msg: &str) {
803 self.emit_diag_at_span(Diagnostic::new(Note, msg), span);
806 pub fn span_note_diag(&self, span: Span, msg: &str) -> DiagnosticBuilder<'_> {
807 let mut db = DiagnosticBuilder::new(self, Note, msg);
812 // NOTE: intentionally doesn't raise an error so rustc_codegen_ssa only reports fatal errors in the main thread
813 pub fn fatal(&self, msg: &str) -> FatalError {
814 self.inner.borrow_mut().fatal(msg)
817 pub fn err(&self, msg: &str) {
818 self.inner.borrow_mut().err(msg);
821 pub fn warn(&self, msg: &str) {
822 let mut db = DiagnosticBuilder::new(self, Warning, msg);
826 pub fn note_without_error(&self, msg: &str) {
827 DiagnosticBuilder::new(self, Note, msg).emit();
830 pub fn bug(&self, msg: &str) -> ! {
831 self.inner.borrow_mut().bug(msg)
835 pub fn err_count(&self) -> usize {
836 self.inner.borrow().err_count()
839 pub fn has_errors(&self) -> bool {
840 self.inner.borrow().has_errors()
842 pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
843 self.inner.borrow().has_errors_or_delayed_span_bugs()
846 pub fn print_error_count(&self, registry: &Registry) {
847 self.inner.borrow_mut().print_error_count(registry)
850 pub fn take_future_breakage_diagnostics(&self) -> Vec<Diagnostic> {
851 std::mem::take(&mut self.inner.borrow_mut().future_breakage_diagnostics)
854 pub fn abort_if_errors(&self) {
855 self.inner.borrow_mut().abort_if_errors()
858 /// `true` if we haven't taught a diagnostic with this code already.
859 /// The caller must then teach the user about such a diagnostic.
861 /// Used to suppress emitting the same error multiple times with extended explanation when
862 /// calling `-Zteach`.
863 pub fn must_teach(&self, code: &DiagnosticId) -> bool {
864 self.inner.borrow_mut().must_teach(code)
867 pub fn force_print_diagnostic(&self, db: Diagnostic) {
868 self.inner.borrow_mut().force_print_diagnostic(db)
871 pub fn emit_diagnostic(&self, diagnostic: &Diagnostic) {
872 self.inner.borrow_mut().emit_diagnostic(diagnostic)
875 fn emit_diag_at_span(&self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
876 let mut inner = self.inner.borrow_mut();
877 inner.emit_diagnostic(diag.set_span(sp));
880 pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
881 self.inner.borrow_mut().emit_artifact_notification(path, artifact_type)
884 pub fn emit_future_breakage_report(&self, diags: Vec<Diagnostic>) {
885 self.inner.borrow_mut().emitter.emit_future_breakage_report(diags)
888 pub fn emit_unused_externs(&self, lint_level: &str, unused_externs: &[&str]) {
889 self.inner.borrow_mut().emit_unused_externs(lint_level, unused_externs)
892 pub fn delay_as_bug(&self, diagnostic: Diagnostic) {
893 self.inner.borrow_mut().delay_as_bug(diagnostic)
898 fn must_teach(&mut self, code: &DiagnosticId) -> bool {
899 self.taught_diagnostics.insert(code.clone())
902 fn force_print_diagnostic(&mut self, db: Diagnostic) {
903 self.emitter.emit_diagnostic(&db);
906 /// Emit all stashed diagnostics.
907 fn emit_stashed_diagnostics(&mut self) {
908 let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>();
909 diags.iter().for_each(|diag| self.emit_diagnostic(diag));
912 fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) {
913 if diagnostic.cancelled() || self.quiet {
917 if diagnostic.has_future_breakage() {
918 self.future_breakage_diagnostics.push(diagnostic.clone());
921 if diagnostic.level == Warning
922 && !self.flags.can_emit_warnings
923 && !diagnostic.is_force_warn()
925 if diagnostic.has_future_breakage() {
926 (*TRACK_DIAGNOSTICS)(diagnostic);
931 (*TRACK_DIAGNOSTICS)(diagnostic);
933 if diagnostic.level == Allow {
937 if let Some(ref code) = diagnostic.code {
938 self.emitted_diagnostic_codes.insert(code.clone());
941 let already_emitted = |this: &mut Self| {
942 let mut hasher = StableHasher::new();
943 diagnostic.hash(&mut hasher);
944 let diagnostic_hash = hasher.finish();
945 !this.emitted_diagnostics.insert(diagnostic_hash)
948 // Only emit the diagnostic if we've been asked to deduplicate and
949 // haven't already emitted an equivalent diagnostic.
950 if !(self.flags.deduplicate_diagnostics && already_emitted(self)) {
951 self.emitter.emit_diagnostic(diagnostic);
952 if diagnostic.is_error() {
953 self.deduplicated_err_count += 1;
954 } else if diagnostic.level == Warning {
955 self.deduplicated_warn_count += 1;
958 if diagnostic.is_error() {
959 self.bump_err_count();
961 self.bump_warn_count();
965 fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) {
966 self.emitter.emit_artifact_notification(path, artifact_type);
969 fn emit_unused_externs(&mut self, lint_level: &str, unused_externs: &[&str]) {
970 self.emitter.emit_unused_externs(lint_level, unused_externs);
973 fn treat_err_as_bug(&self) -> bool {
974 self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() >= c.get())
977 fn print_error_count(&mut self, registry: &Registry) {
978 self.emit_stashed_diagnostics();
980 let warnings = match self.deduplicated_warn_count {
982 1 => "1 warning emitted".to_string(),
983 count => format!("{} warnings emitted", count),
985 let errors = match self.deduplicated_err_count {
987 1 => "aborting due to previous error".to_string(),
988 count => format!("aborting due to {} previous errors", count),
990 if self.treat_err_as_bug() {
994 match (errors.len(), warnings.len()) {
996 (0, _) => self.emitter.emit_diagnostic(&Diagnostic::new(Level::Warning, &warnings)),
998 let _ = self.fatal(&errors);
1001 let _ = self.fatal(&format!("{}; {}", &errors, &warnings));
1005 let can_show_explain = self.emitter.should_show_explain();
1006 let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty();
1007 if can_show_explain && are_there_diagnostics {
1008 let mut error_codes = self
1009 .emitted_diagnostic_codes
1011 .filter_map(|x| match &x {
1012 DiagnosticId::Error(s) => {
1013 if let Ok(Some(_explanation)) = registry.try_find_description(s) {
1021 .collect::<Vec<_>>();
1022 if !error_codes.is_empty() {
1024 if error_codes.len() > 1 {
1025 let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
1026 self.failure(&format!(
1027 "Some errors have detailed explanations: {}{}",
1028 error_codes[..limit].join(", "),
1029 if error_codes.len() > 9 { "..." } else { "." }
1031 self.failure(&format!(
1032 "For more information about an error, try \
1033 `rustc --explain {}`.",
1037 self.failure(&format!(
1038 "For more information about this error, try \
1039 `rustc --explain {}`.",
1048 fn err_count(&self) -> usize {
1049 self.err_count + self.stashed_diagnostics.len()
1052 fn has_errors(&self) -> bool {
1053 self.err_count() > 0
1055 fn has_errors_or_delayed_span_bugs(&self) -> bool {
1056 self.has_errors() || !self.delayed_span_bugs.is_empty()
1058 fn has_any_message(&self) -> bool {
1059 self.err_count() > 0 || self.warn_count > 0
1062 fn abort_if_errors(&mut self) {
1063 self.emit_stashed_diagnostics();
1065 if self.has_errors() {
1070 fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) -> ! {
1071 self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp);
1072 panic::panic_any(ExplicitBug);
1075 fn emit_diag_at_span(&mut self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
1076 self.emit_diagnostic(diag.set_span(sp));
1080 fn delay_span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) {
1081 // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
1082 // incrementing `err_count` by one, so we need to +1 the comparing.
1083 // FIXME: Would be nice to increment err_count in a more coherent way.
1084 if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c.get()) {
1085 // FIXME: don't abort here if report_delayed_bugs is off
1086 self.span_bug(sp, msg);
1088 let mut diagnostic = Diagnostic::new(Level::Bug, msg);
1089 diagnostic.set_span(sp.into());
1090 diagnostic.note(&format!("delayed at {}", std::panic::Location::caller()));
1091 self.delay_as_bug(diagnostic)
1094 fn delay_good_path_bug(&mut self, msg: &str) {
1095 let diagnostic = Diagnostic::new(Level::Bug, msg);
1096 if self.flags.report_delayed_bugs {
1097 self.emit_diagnostic(&diagnostic);
1099 let backtrace = std::backtrace::Backtrace::force_capture();
1100 self.delayed_good_path_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace));
1103 fn failure(&mut self, msg: &str) {
1104 self.emit_diagnostic(&Diagnostic::new(FailureNote, msg));
1107 fn fatal(&mut self, msg: &str) -> FatalError {
1108 self.emit_error(Fatal, msg);
1112 fn err(&mut self, msg: &str) {
1113 self.emit_error(Error, msg);
1116 /// Emit an error; level should be `Error` or `Fatal`.
1117 fn emit_error(&mut self, level: Level, msg: &str) {
1118 if self.treat_err_as_bug() {
1121 self.emit_diagnostic(&Diagnostic::new(level, msg));
1124 fn bug(&mut self, msg: &str) -> ! {
1125 self.emit_diagnostic(&Diagnostic::new(Bug, msg));
1126 panic::panic_any(ExplicitBug);
1129 fn delay_as_bug(&mut self, diagnostic: Diagnostic) {
1133 if self.flags.report_delayed_bugs {
1134 self.emit_diagnostic(&diagnostic);
1136 self.delayed_span_bugs.push(diagnostic);
1139 fn flush_delayed(&mut self, bugs: Vec<Diagnostic>, explanation: &str) {
1140 let has_bugs = !bugs.is_empty();
1142 self.emit_diagnostic(&bug);
1145 panic!("{}", explanation);
1149 fn bump_err_count(&mut self) {
1150 self.err_count += 1;
1151 self.panic_if_treat_err_as_bug();
1154 fn bump_warn_count(&mut self) {
1155 self.warn_count += 1;
1158 fn panic_if_treat_err_as_bug(&self) {
1159 if self.treat_err_as_bug() {
1160 match (self.err_count(), self.flags.treat_err_as_bug.map(|c| c.get()).unwrap_or(0)) {
1161 (1, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
1162 (0, _) | (1, _) => {}
1163 (count, as_bug) => panic!(
1164 "aborting after {} errors due to `-Z treat-err-as-bug={}`",
1172 struct DelayedDiagnostic {
1177 impl DelayedDiagnostic {
1178 fn with_backtrace(diagnostic: Diagnostic, backtrace: Backtrace) -> Self {
1179 DelayedDiagnostic { inner: diagnostic, note: backtrace }
1182 fn decorate(mut self) -> Diagnostic {
1183 self.inner.note(&format!("delayed at {}", self.note));
1188 #[derive(Copy, PartialEq, Clone, Hash, Debug, Encodable, Decodable)]
1201 impl fmt::Display for Level {
1202 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1203 self.to_str().fmt(f)
1208 fn color(self) -> ColorSpec {
1209 let mut spec = ColorSpec::new();
1211 Bug | Fatal | Error => {
1212 spec.set_fg(Some(Color::Red)).set_intense(true);
1215 spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows));
1218 spec.set_fg(Some(Color::Green)).set_intense(true);
1221 spec.set_fg(Some(Color::Cyan)).set_intense(true);
1224 Allow | Cancelled => unreachable!(),
1229 pub fn to_str(self) -> &'static str {
1231 Bug => "error: internal compiler error",
1232 Fatal | Error => "error",
1233 Warning => "warning",
1236 FailureNote => "failure-note",
1237 Cancelled => panic!("Shouldn't call on cancelled error"),
1238 Allow => panic!("Shouldn't call on allowed error"),
1242 pub fn is_failure_note(&self) -> bool {
1243 matches!(*self, FailureNote)
1247 pub fn add_elided_lifetime_in_path_suggestion(
1248 source_map: &SourceMap,
1249 db: &mut DiagnosticBuilder<'_>,
1252 incl_angl_brckt: bool,
1253 insertion_span: Span,
1256 let (replace_span, suggestion) = if incl_angl_brckt {
1257 (insertion_span, anon_lts)
1259 // When possible, prefer a suggestion that replaces the whole
1260 // `Path<T>` expression with `Path<'_, T>`, rather than inserting `'_, `
1261 // at a point (which makes for an ugly/confusing label)
1262 if let Ok(snippet) = source_map.span_to_snippet(path_span) {
1263 // But our spans can get out of whack due to macros; if the place we think
1264 // we want to insert `'_` isn't even within the path expression's span, we
1265 // should bail out of making any suggestion rather than panicking on a
1266 // subtract-with-overflow or string-slice-out-out-bounds (!)
1267 // FIXME: can we do better?
1268 if insertion_span.lo().0 < path_span.lo().0 {
1271 let insertion_index = (insertion_span.lo().0 - path_span.lo().0) as usize;
1272 if insertion_index > snippet.len() {
1275 let (before, after) = snippet.split_at(insertion_index);
1276 (path_span, format!("{}{}{}", before, anon_lts, after))
1278 (insertion_span, anon_lts)
1283 &format!("indicate the anonymous lifetime{}", pluralize!(n)),
1285 Applicability::MachineApplicable,
1289 // Useful type to use with `Result<>` indicate that an error has already
1290 // been reported to the user, so no need to continue checking.
1291 #[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq)]
1292 pub struct ErrorReported;
1294 rustc_data_structures::impl_stable_hash_via_hash!(ErrorReported);