1 //! The current rustc diagnostics emitter.
3 //! An `Emitter` takes care of generating the output from a `DiagnosticBuilder` struct.
5 //! There are various `Emitter` implementations that generate different output formats such as
6 //! JSON and human readable output.
8 //! The output types are defined in `rustc_session::config::ErrorOutputType`.
12 use rustc_span::source_map::SourceMap;
13 use rustc_span::{FileLines, SourceFile, Span};
15 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
16 use crate::styled_buffer::StyledBuffer;
17 use crate::translation::Translate;
19 CodeSuggestion, Diagnostic, DiagnosticId, DiagnosticMessage, FluentBundle, Handler,
20 LazyFallbackBundle, Level, MultiSpan, SubDiagnostic, SubstitutionHighlight, SuggestionStyle,
23 use rustc_lint_defs::pluralize;
25 use rustc_data_structures::fx::FxHashMap;
26 use rustc_data_structures::sync::Lrc;
27 use rustc_error_messages::FluentArgs;
28 use rustc_span::hygiene::{ExpnKind, MacroKind};
30 use std::cmp::{max, min, Reverse};
32 use std::io::prelude::*;
35 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
36 use termcolor::{Buffer, Color, WriteColor};
39 /// Default column width, used in tests and when terminal dimensions cannot be determined.
40 const DEFAULT_COLUMN_WIDTH: usize = 140;
42 /// Describes the way the content of the `rendered` field of the json output is generated
43 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
44 pub enum HumanReadableErrorType {
46 AnnotateSnippet(ColorConfig),
50 impl HumanReadableErrorType {
51 /// Returns a (`short`, `color`) tuple
52 pub fn unzip(self) -> (bool, ColorConfig) {
54 HumanReadableErrorType::Default(cc) => (false, cc),
55 HumanReadableErrorType::Short(cc) => (true, cc),
56 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
61 dst: Box<dyn Write + Send>,
62 source_map: Option<Lrc<SourceMap>>,
63 bundle: Option<Lrc<FluentBundle>>,
64 fallback_bundle: LazyFallbackBundle,
66 diagnostic_width: Option<usize>,
67 macro_backtrace: bool,
69 let (short, color_config) = self.unzip();
70 let color = color_config.suggests_using_colors();
85 #[derive(Clone, Copy, Debug)]
87 /// The available whitespace in the left that can be consumed when centering.
88 pub whitespace_left: usize,
89 /// The column of the beginning of left-most span.
91 /// The column of the end of right-most span.
92 pub span_right: usize,
93 /// The beginning of the line to be displayed.
94 pub computed_left: usize,
95 /// The end of the line to be displayed.
96 pub computed_right: usize,
97 /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default
99 pub column_width: usize,
100 /// The end column of a span label, including the span. Doesn't account for labels not in the
101 /// same line as the span.
102 pub label_right: usize,
107 whitespace_left: usize,
114 // The 6 is padding to give a bit of room for `...` when displaying:
119 // 16 | ... fn foo(self) -> Self::Bar {
124 whitespace_left: whitespace_left.saturating_sub(6),
125 span_left: span_left.saturating_sub(6),
126 span_right: span_right + 6,
130 label_right: label_right + 6,
132 m.compute(max_line_len);
136 fn was_cut_left(&self) -> bool {
137 self.computed_left > 0
140 fn was_cut_right(&self, line_len: usize) -> bool {
142 if self.computed_right == self.span_right || self.computed_right == self.label_right {
143 // Account for the "..." padding given above. Otherwise we end up with code lines that
144 // do fit but end in "..." as if they were trimmed.
145 self.computed_right - 6
149 right < line_len && self.computed_left + self.column_width < line_len
152 fn compute(&mut self, max_line_len: usize) {
153 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
154 self.computed_left = if self.whitespace_left > 20 {
155 self.whitespace_left - 16 // We want some padding.
159 // We want to show as much as possible, max_line_len is the right-most boundary for the
161 self.computed_right = max(max_line_len, self.computed_left);
163 if self.computed_right - self.computed_left > self.column_width {
164 // Trimming only whitespace isn't enough, let's get craftier.
165 if self.label_right - self.whitespace_left <= self.column_width {
166 // Attempt to fit the code window only trimming whitespace.
167 self.computed_left = self.whitespace_left;
168 self.computed_right = self.computed_left + self.column_width;
169 } else if self.label_right - self.span_left <= self.column_width {
170 // Attempt to fit the code window considering only the spans and labels.
171 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
172 self.computed_left = self.span_left.saturating_sub(padding_left);
173 self.computed_right = self.computed_left + self.column_width;
174 } else if self.span_right - self.span_left <= self.column_width {
175 // Attempt to fit the code window considering the spans and labels plus padding.
176 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
177 self.computed_left = self.span_left.saturating_sub(padding_left);
178 self.computed_right = self.computed_left + self.column_width;
180 // Mostly give up but still don't show the full line.
181 self.computed_left = self.span_left;
182 self.computed_right = self.span_right;
187 fn left(&self, line_len: usize) -> usize {
188 min(self.computed_left, line_len)
191 fn right(&self, line_len: usize) -> usize {
192 if line_len.saturating_sub(self.computed_left) <= self.column_width {
195 min(line_len, self.computed_right)
200 const ANONYMIZED_LINE_NUM: &str = "LL";
202 /// Emitter trait for emitting errors.
203 pub trait Emitter: Translate {
204 /// Emit a structured diagnostic.
205 fn emit_diagnostic(&mut self, diag: &Diagnostic);
207 /// Emit a notification that an artifact has been output.
208 /// This is currently only supported for the JSON format,
209 /// other formats can, and will, simply ignore it.
210 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
212 fn emit_future_breakage_report(&mut self, _diags: Vec<Diagnostic>) {}
214 /// Emit list of unused externs
215 fn emit_unused_externs(
217 _lint_level: rustc_lint_defs::Level,
218 _unused_externs: &[&str],
222 /// Checks if should show explanations about "rustc --explain"
223 fn should_show_explain(&self) -> bool {
227 /// Checks if we can use colors in the current output stream.
228 fn supports_color(&self) -> bool {
232 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
234 /// Formats the substitutions of the primary_span
236 /// There are a lot of conditions to this method, but in short:
238 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
239 /// we format the `help` suggestion depending on the content of the
240 /// substitutions. In that case, we return the modified span only.
242 /// * If the current `Diagnostic` has multiple suggestions,
243 /// we return the original `primary_span` and the original suggestions.
244 fn primary_span_formatted<'a>(
246 diag: &'a Diagnostic,
247 fluent_args: &FluentArgs<'_>,
248 ) -> (MultiSpan, &'a [CodeSuggestion]) {
249 let mut primary_span = diag.span.clone();
250 let suggestions = diag.suggestions.as_ref().map_or(&[][..], |suggestions| &suggestions[..]);
251 if let Some((sugg, rest)) = suggestions.split_first() {
252 let msg = self.translate_message(&sugg.msg, fluent_args);
253 if rest.is_empty() &&
254 // ^ if there is only one suggestion
255 // don't display multi-suggestions as labels
256 sugg.substitutions.len() == 1 &&
257 // don't display multipart suggestions as labels
258 sugg.substitutions[0].parts.len() == 1 &&
259 // don't display long messages as labels
260 msg.split_whitespace().count() < 10 &&
261 // don't display multiline suggestions as labels
262 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
264 // when this style is set we want the suggestion to be a message, not inline
265 SuggestionStyle::HideCodeAlways,
266 // trivial suggestion for tooling's sake, never shown
267 SuggestionStyle::CompletelyHidden,
268 // subtle suggestion, never shown inline
269 SuggestionStyle::ShowAlways,
270 ].contains(&sugg.style)
272 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
273 let msg = if substitution.is_empty() || sugg.style.hide_inline() {
274 // This substitution is only removal OR we explicitly don't want to show the
275 // code inline (`hide_inline`). Therefore, we don't show the substitution.
276 format!("help: {}", &msg)
278 // Show the default suggestion text with the substitution
284 .map(|sm| is_case_difference(
287 sugg.substitutions[0].parts[0].span,
291 " (notice the capitalization)"
298 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
300 // We return only the modified primary_span
303 // if there are multiple suggestions, print them all in full
304 // to be consistent. We could try to figure out if we can
305 // make one (or the first one) inline, but that would give
306 // undue importance to a semi-random suggestion
307 (primary_span, suggestions)
310 (primary_span, suggestions)
314 fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
316 source_map: &Option<Lrc<SourceMap>>,
317 span: &mut MultiSpan,
318 children: &mut Vec<SubDiagnostic>,
322 // Check for spans in macros, before `fix_multispans_in_extern_macros`
323 // has a chance to replace them.
324 let has_macro_spans: Vec<_> = iter::once(&*span)
325 .chain(children.iter().map(|child| &child.span))
326 .flat_map(|span| span.primary_spans())
327 .flat_map(|sp| sp.macro_backtrace())
328 .filter_map(|expn_data| {
329 match expn_data.kind {
330 ExpnKind::Root => None,
332 // Skip past non-macro entries, just in case there
333 // are some which do actually involve macros.
334 ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
336 ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)),
342 self.fix_multispans_in_extern_macros(source_map, span, children);
345 self.render_multispans_macro_backtrace(span, children, backtrace);
348 if let Some((macro_kind, name)) = has_macro_spans.first() {
349 // Mark the actual macro this originates from
350 let and_then = if let Some((macro_kind, last_name)) = has_macro_spans.last()
353 let descr = macro_kind.descr();
355 " which comes from the expansion of the {descr} `{last_name}`",
361 let descr = macro_kind.descr();
363 "this {level} originates in the {descr} `{name}`{and_then} \
364 (in Nightly builds, run with -Z macro-backtrace for more info)",
367 children.push(SubDiagnostic {
369 message: vec![(DiagnosticMessage::Str(msg), Style::NoStyle)],
370 span: MultiSpan::new(),
377 fn render_multispans_macro_backtrace(
379 span: &mut MultiSpan,
380 children: &mut Vec<SubDiagnostic>,
383 for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
384 self.render_multispan_macro_backtrace(span, backtrace);
388 fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
389 let mut new_labels: Vec<(Span, String)> = vec![];
391 for &sp in span.primary_spans() {
396 // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
397 // entries we don't want to print, to make sure the indices being
398 // printed are contiguous (or omitted if there's only one entry).
399 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
400 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
401 if trace.def_site.is_dummy() {
405 if always_backtrace && !matches!(trace.kind, ExpnKind::Inlined) {
409 "in this expansion of `{}`{}",
411 if macro_backtrace.len() > 1 {
412 // if macro_backtrace.len() == 1 it'll be
413 // pointed at by "in this macro invocation"
414 format!(" (#{})", i + 1)
422 // Don't add a label on the call site if the diagnostic itself
423 // already points to (a part of) that call site, as the label
424 // is meant for showing the relevant invocation when the actual
425 // diagnostic is pointing to some part of macro definition.
427 // This also handles the case where an external span got replaced
428 // with the call site span by `fix_multispans_in_extern_macros`.
430 // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
431 // "in this expansion of" label above is always added in that mode,
432 // and it needs an "in this macro invocation" label to match that.
433 let redundant_span = trace.call_site.contains(sp);
435 if !redundant_span || always_backtrace {
436 let msg: Cow<'static, _> = match trace.kind {
437 ExpnKind::Macro(MacroKind::Attr, _) => {
438 "this procedural macro expansion".into()
440 ExpnKind::Macro(MacroKind::Derive, _) => {
441 "this derive macro expansion".into()
443 ExpnKind::Macro(MacroKind::Bang, _) => "this macro invocation".into(),
444 ExpnKind::Inlined => "this inlined function call".into(),
445 ExpnKind::Root => "the crate root".into(),
446 ExpnKind::AstPass(kind) => kind.descr().into(),
447 ExpnKind::Desugaring(kind) => {
448 format!("this {} desugaring", kind.descr()).into()
456 if macro_backtrace.len() > 1 && always_backtrace {
457 // only specify order when the macro
458 // backtrace is multiple levels deep
459 format!(" (#{})", i + 1)
466 if !always_backtrace {
472 for (label_span, label_text) in new_labels {
473 span.push_span_label(label_span, label_text);
477 // This does a small "fix" for multispans by looking to see if it can find any that
478 // point directly at external macros. Since these are often difficult to read,
479 // this will change the span to point at the use site.
480 fn fix_multispans_in_extern_macros(
482 source_map: &Option<Lrc<SourceMap>>,
483 span: &mut MultiSpan,
484 children: &mut Vec<SubDiagnostic>,
486 let Some(source_map) = source_map else { return };
487 debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
488 self.fix_multispan_in_extern_macros(source_map, span);
489 for child in children.iter_mut() {
490 self.fix_multispan_in_extern_macros(source_map, &mut child.span);
492 debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
495 // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
496 // Since these locations are often difficult to read,
497 // we move these spans from the external macros to their corresponding use site.
498 fn fix_multispan_in_extern_macros(&self, source_map: &Lrc<SourceMap>, span: &mut MultiSpan) {
499 // First, find all the spans in external macros and point instead at their use site.
500 let replacements: Vec<(Span, Span)> = span
504 .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
506 if !sp.is_dummy() && source_map.is_imported(sp) {
507 let maybe_callsite = sp.source_callsite();
508 if sp != maybe_callsite {
509 return Some((sp, maybe_callsite));
516 // After we have them, make sure we replace these 'bad' def sites with their use sites.
517 for (from, to) in replacements {
518 span.replace(from, to);
523 impl Translate for EmitterWriter {
524 fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
525 self.fluent_bundle.as_ref()
528 fn fallback_fluent_bundle(&self) -> &FluentBundle {
529 &**self.fallback_bundle
533 impl Emitter for EmitterWriter {
534 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
538 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
539 let fluent_args = self.to_fluent_args(diag.args());
541 let mut children = diag.children.clone();
542 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag, &fluent_args);
543 debug!("emit_diagnostic: suggestions={:?}", suggestions);
545 self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
550 self.macro_backtrace,
553 self.emit_messages_default(
564 fn should_show_explain(&self) -> bool {
568 fn supports_color(&self) -> bool {
569 self.dst.supports_color()
573 /// An emitter that does nothing when emitting a non-fatal diagnostic.
574 /// Fatal diagnostics are forwarded to `fatal_handler` to avoid silent
575 /// failures of rustc, as witnessed e.g. in issue #89358.
576 pub struct SilentEmitter {
577 pub fatal_handler: Handler,
578 pub fatal_note: Option<String>,
581 impl Translate for SilentEmitter {
582 fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
586 fn fallback_fluent_bundle(&self) -> &FluentBundle {
587 panic!("silent emitter attempted to translate message")
591 impl Emitter for SilentEmitter {
592 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
596 fn emit_diagnostic(&mut self, d: &Diagnostic) {
597 if d.level == Level::Fatal {
598 let mut d = d.clone();
599 if let Some(ref note) = self.fatal_note {
602 self.fatal_handler.emit_diagnostic(&mut d);
607 /// Maximum number of suggestions to be shown
609 /// Arbitrary, but taken from trait import suggestion limit
610 pub const MAX_SUGGESTIONS: usize = 4;
612 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
613 pub enum ColorConfig {
620 fn to_color_choice(self) -> ColorChoice {
622 ColorConfig::Always => {
623 if atty::is(atty::Stream::Stderr) {
626 ColorChoice::AlwaysAnsi
629 ColorConfig::Never => ColorChoice::Never,
630 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
631 ColorConfig::Auto => ColorChoice::Never,
634 fn suggests_using_colors(self) -> bool {
636 ColorConfig::Always | ColorConfig::Auto => true,
637 ColorConfig::Never => false,
642 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
643 pub struct EmitterWriter {
645 sm: Option<Lrc<SourceMap>>,
646 fluent_bundle: Option<Lrc<FluentBundle>>,
647 fallback_bundle: LazyFallbackBundle,
651 diagnostic_width: Option<usize>,
653 macro_backtrace: bool,
657 pub struct FileWithAnnotatedLines {
658 pub file: Lrc<SourceFile>,
659 pub lines: Vec<Line>,
660 multiline_depth: usize,
665 color_config: ColorConfig,
666 source_map: Option<Lrc<SourceMap>>,
667 fluent_bundle: Option<Lrc<FluentBundle>>,
668 fallback_bundle: LazyFallbackBundle,
671 diagnostic_width: Option<usize>,
672 macro_backtrace: bool,
674 let dst = Destination::from_stderr(color_config);
689 dst: Box<dyn Write + Send>,
690 source_map: Option<Lrc<SourceMap>>,
691 fluent_bundle: Option<Lrc<FluentBundle>>,
692 fallback_bundle: LazyFallbackBundle,
696 diagnostic_width: Option<usize>,
697 macro_backtrace: bool,
700 dst: Raw(dst, colored),
712 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
713 self.ui_testing = ui_testing;
717 fn maybe_anonymized(&self, line_num: usize) -> Cow<'static, str> {
719 Cow::Borrowed(ANONYMIZED_LINE_NUM)
721 Cow::Owned(line_num.to_string())
727 buffer: &mut StyledBuffer,
735 // Tabs are assumed to have been replaced by spaces in calling code.
736 debug_assert!(!source_string.contains('\t'));
737 let line_len = source_string.len();
738 // Create the source line we will highlight.
739 let left = margin.left(line_len);
740 let right = margin.right(line_len);
741 // On long lines, we strip the source line, accounting for unicode.
743 let code: String = source_string
747 // Make sure that the trimming on the right will fall within the terminal width.
748 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
749 // For now, just accept that sometimes the code line will be longer than desired.
750 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
751 if taken + next > right - left {
758 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
759 if margin.was_cut_left() {
760 // We have stripped some code/whitespace from the beginning, make it clear.
761 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
763 if margin.was_cut_right(line_len) {
764 // We have stripped some code after the right-most span end, make it clear we did so.
765 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
767 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
769 draw_col_separator_no_space(buffer, line_offset, width_offset - 2);
772 fn render_source_line(
774 buffer: &mut StyledBuffer,
775 file: Lrc<SourceFile>,
780 ) -> Vec<(usize, Style)> {
786 // | secondary span label
788 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
790 // | | | actual code found in your source code and the spans we use to mark it
791 // | | when there's too much wasted space to the left, trim it
792 // | vertical divider between the column number and the code
795 if line.line_index == 0 {
799 let source_string = match file.get_line(line.line_index - 1) {
800 Some(s) => normalize_whitespace(&*s),
801 None => return Vec::new(),
804 let line_offset = buffer.num_lines();
807 let left = margin.left(source_string.len());
809 // Account for unicode characters of width !=0 that were removed.
810 let left = source_string
813 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
826 // Special case when there's only one annotation involved, it is the start of a multiline
827 // span and there's no text at the beginning of the code line. Instead of doing the whole
836 // we simplify the output to:
842 if let [ann] = &line.annotations[..] {
843 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
844 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
845 let style = if ann.is_primary {
846 Style::UnderlinePrimary
848 Style::UnderlineSecondary
850 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
851 return vec![(depth, style)];
856 // We want to display like this:
858 // vec.push(vec.pop().unwrap());
859 // --- ^^^ - previous borrow ends here
861 // | error occurs here
862 // previous borrow of `vec` occurs here
864 // But there are some weird edge cases to be aware of:
866 // vec.push(vec.pop().unwrap());
867 // -------- - previous borrow ends here
869 // |this makes no sense
870 // previous borrow of `vec` occurs here
872 // For this reason, we group the lines into "highlight lines"
873 // and "annotations lines", where the highlight lines have the `^`.
875 // Sort the annotations by (start, end col)
876 // The labels are reversed, sort and then reversed again.
877 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
878 // the letter signifies the span. Here we are only sorting by the
879 // span and hence, the order of the elements with the same span will
880 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
881 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
882 // still ordered first to last, but all the elements with different
883 // spans are ordered by their spans in last to first order. Last to
884 // first order is important, because the jiggly lines and | are on
885 // the left, so the rightmost span needs to be rendered first,
886 // otherwise the lines would end up needing to go over a message.
888 let mut annotations = line.annotations.clone();
889 annotations.sort_by_key(|a| Reverse(a.start_col));
891 // First, figure out where each label will be positioned.
893 // In the case where you have the following annotations:
895 // vec.push(vec.pop().unwrap());
896 // -------- - previous borrow ends here [C]
898 // |this makes no sense [B]
899 // previous borrow of `vec` occurs here [A]
901 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
903 // We try, when possible, to stick the rightmost annotation at the end
904 // of the highlight line:
906 // vec.push(vec.pop().unwrap());
907 // --- --- - previous borrow ends here
909 // But sometimes that's not possible because one of the other
910 // annotations overlaps it. For example, from the test
911 // `span_overlap_label`, we have the following annotations
912 // (written on distinct lines for clarity):
918 // In this case, we can't stick the rightmost-most label on
919 // the highlight line, or we would get:
926 // which is totally weird. Instead we want:
934 // which is...less weird, at least. In fact, in general, if
935 // the rightmost span overlaps with any other span, we should
936 // use the "hang below" version, so we can at least make it
937 // clear where the span *starts*. There's an exception for this
938 // logic, when the labels do not have a message:
953 let mut annotations_position = vec![];
954 let mut line_len = 0;
956 for (i, annotation) in annotations.iter().enumerate() {
957 for (j, next) in annotations.iter().enumerate() {
958 if overlaps(next, annotation, 0) // This label overlaps with another one and both
959 && annotation.has_label() // take space (they have text and are not
960 && j > i // multiline lines).
962 // We're currently on the first line, move the label one line down
964 // If we're overlapping with an un-labelled annotation with the same span
965 // we can just merge them in the output
966 if next.start_col == annotation.start_col
967 && next.end_col == annotation.end_col
973 // This annotation needs a new line in the output.
978 annotations_position.push((p, annotation));
979 for (j, next) in annotations.iter().enumerate() {
981 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
982 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
983 // line if they overlap including padding, to
984 // avoid situations like:
991 && annotation.has_label() // Both labels must have some text, otherwise
992 && next.has_label()) // they are not overlapping.
993 // Do not add a new line if this annotation
994 // or the next are vertical line placeholders.
995 || (annotation.takes_space() // If either this or the next annotation is
996 && next.has_label()) // multiline start/end, move it to a new line
997 || (annotation.has_label() // so as not to overlap the horizontal lines.
998 && next.takes_space())
999 || (annotation.takes_space() && next.takes_space())
1000 || (overlaps(next, annotation, l)
1001 && next.end_col <= annotation.end_col
1006 // This annotation needs a new line in the output.
1012 line_len = max(line_len, p);
1019 // If there are no annotations or the only annotations on this line are
1020 // MultilineLine, then there's only code being shown, stop processing.
1021 if line.annotations.iter().all(|a| a.is_line()) {
1025 // Write the column separator.
1027 // After this we will have:
1036 for pos in 0..=line_len {
1037 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
1040 // Write the horizontal lines for multiline annotations
1041 // (only the first and last lines need this).
1043 // After this we will have:
1052 for &(pos, annotation) in &annotations_position {
1053 let style = if annotation.is_primary {
1054 Style::UnderlinePrimary
1056 Style::UnderlineSecondary
1059 match annotation.annotation_type {
1060 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
1065 width_offset + depth,
1066 (code_offset + annotation.start_col).saturating_sub(left),
1070 _ if self.teach => {
1071 buffer.set_style_range(
1073 (code_offset + annotation.start_col).saturating_sub(left),
1074 (code_offset + annotation.end_col).saturating_sub(left),
1076 annotation.is_primary,
1083 // Write the vertical lines for labels that are on a different line as the underline.
1085 // After this we will have:
1094 for &(pos, annotation) in &annotations_position {
1095 let style = if annotation.is_primary {
1096 Style::UnderlinePrimary
1098 Style::UnderlineSecondary
1102 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
1103 for p in line_offset + 1..=line_offset + pos {
1106 (code_offset + annotation.start_col).saturating_sub(left),
1112 match annotation.annotation_type {
1113 AnnotationType::MultilineStart(depth) => {
1114 for p in line_offset + pos + 1..line_offset + line_len + 2 {
1115 buffer.putc(p, width_offset + depth - 1, '|', style);
1118 AnnotationType::MultilineEnd(depth) => {
1119 for p in line_offset..=line_offset + pos {
1120 buffer.putc(p, width_offset + depth - 1, '|', style);
1127 // Write the labels on the annotations that actually have a label.
1129 // After this we will have:
1134 // | something about `foo`
1138 for &(pos, annotation) in &annotations_position {
1140 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1141 let (pos, col) = if pos == 0 {
1142 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1144 (pos + 2, annotation.start_col.saturating_sub(left))
1146 if let Some(ref label) = annotation.label {
1147 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1151 // Sort from biggest span to smallest span so that smaller spans are
1152 // represented in the output:
1157 // | | something about `foo`
1158 // | something about `fn foo()`
1159 annotations_position.sort_by_key(|(_, ann)| {
1160 // Decreasing order. When annotations share the same length, prefer `Primary`.
1161 (Reverse(ann.len()), ann.is_primary)
1164 // Write the underlines.
1166 // After this we will have:
1171 // | something about `foo`
1175 for &(_, annotation) in &annotations_position {
1176 let (underline, style) = if annotation.is_primary {
1177 ('^', Style::UnderlinePrimary)
1179 ('-', Style::UnderlineSecondary)
1181 for p in annotation.start_col..annotation.end_col {
1184 (code_offset + p).saturating_sub(left),
1190 annotations_position
1192 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1193 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1194 let style = if annotation.is_primary {
1197 Style::LabelSecondary
1203 .collect::<Vec<_>>()
1206 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1207 let Some(ref sm) = self.sm else {
1211 let will_be_emitted = |span: Span| {
1212 !span.is_dummy() && {
1213 let file = sm.lookup_source_file(span.hi());
1214 sm.ensure_source_file_source_present(file)
1219 for primary_span in msp.primary_spans() {
1220 if will_be_emitted(*primary_span) {
1221 let hi = sm.lookup_char_pos(primary_span.hi());
1222 max = (hi.line).max(max);
1225 if !self.short_message {
1226 for span_label in msp.span_labels() {
1227 if will_be_emitted(span_label.span) {
1228 let hi = sm.lookup_char_pos(span_label.span.hi());
1229 max = (hi.line).max(max);
1237 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1238 let primary = self.get_multispan_max_line_num(span);
1241 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1247 /// Adds a left margin to every line but the first, given a padding length and the label being
1248 /// displayed, keeping the provided highlighting.
1251 buffer: &mut StyledBuffer,
1252 msg: &[(DiagnosticMessage, Style)],
1253 args: &FluentArgs<'_>,
1256 override_style: Option<Style>,
1258 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1261 // --> file.rs:13:20
1266 // = note: multiline
1271 // | | length of label
1273 // `max_line_num_len`
1274 let padding = " ".repeat(padding + label.len() + 5);
1276 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1277 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1278 match (style, override_) {
1279 (Style::NoStyle, Some(override_)) => override_,
1284 let mut line_number = 0;
1286 // Provided the following diagnostic message:
1290 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1291 // ("looks", Style::Highlight),
1292 // ("with\nvery ", Style::NoStyle),
1293 // ("weird", Style::Highlight),
1294 // (" formats\n", Style::NoStyle),
1295 // ("see?", Style::Highlight),
1298 // the expected output on a note is (* surround the highlighted text)
1300 // = note: highlighted multiline
1302 // see how it *looks* with
1303 // very *weird* formats
1305 for &(ref text, ref style) in msg.iter() {
1306 let text = self.translate_message(text, args);
1307 let lines = text.split('\n').collect::<Vec<_>>();
1308 if lines.len() > 1 {
1309 for (i, line) in lines.iter().enumerate() {
1312 buffer.append(line_number, &padding, Style::NoStyle);
1314 buffer.append(line_number, line, style_or_override(*style, override_style));
1317 buffer.append(line_number, &text, style_or_override(*style, override_style));
1322 fn emit_message_default(
1325 msg: &[(DiagnosticMessage, Style)],
1326 args: &FluentArgs<'_>,
1327 code: &Option<DiagnosticId>,
1329 max_line_num_len: usize,
1331 ) -> io::Result<()> {
1332 let mut buffer = StyledBuffer::new();
1334 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1336 // This is a secondary message with no span info
1337 for _ in 0..max_line_num_len {
1338 buffer.prepend(0, " ", Style::NoStyle);
1340 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1341 if *level != Level::FailureNote {
1342 buffer.append(0, level.to_str(), Style::MainHeaderMsg);
1343 buffer.append(0, ": ", Style::NoStyle);
1345 self.msg_to_buffer(&mut buffer, msg, args, max_line_num_len, "note", None);
1347 let mut label_width = 0;
1348 // The failure note level itself does not provide any useful diagnostic information
1349 if *level != Level::FailureNote {
1350 buffer.append(0, level.to_str(), Style::Level(*level));
1351 label_width += level.to_str().len();
1353 // only render error codes, not lint codes
1354 if let Some(DiagnosticId::Error(ref code)) = *code {
1355 buffer.append(0, "[", Style::Level(*level));
1356 buffer.append(0, &code, Style::Level(*level));
1357 buffer.append(0, "]", Style::Level(*level));
1358 label_width += 2 + code.len();
1360 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1361 if *level != Level::FailureNote {
1362 buffer.append(0, ": ", header_style);
1365 for &(ref text, _) in msg.iter() {
1366 let text = self.translate_message(text, args);
1367 // Account for newlines to align output to its label.
1368 for (line, text) in normalize_whitespace(&text).lines().enumerate() {
1373 if line == 0 { String::new() } else { " ".repeat(label_width) },
1382 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(self, args, msp);
1384 // Make sure our primary file comes first
1385 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1386 (self.sm.as_ref(), msp.primary_span().as_ref())
1388 if !primary_span.is_dummy() {
1389 (sm.lookup_char_pos(primary_span.lo()), sm)
1391 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1395 // If we don't have span information, emit and exit
1396 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1400 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1402 annotated_files.swap(0, pos);
1405 // Print out the annotate source lines that correspond with the error
1406 for annotated_file in annotated_files {
1407 // we can't annotate anything if the source is unavailable.
1408 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1412 // print out the span location and spacer before we print the annotated source
1413 // to do this, we need to know if this span will be primary
1414 let is_primary = primary_lo.file.name == annotated_file.file.name;
1416 let loc = primary_lo.clone();
1417 if !self.short_message {
1418 // remember where we are in the output buffer for easy reference
1419 let buffer_msg_line_offset = buffer.num_lines();
1421 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1423 buffer_msg_line_offset,
1426 sm.filename_for_diagnostics(&loc.file.name),
1427 sm.doctest_offset_line(&loc.file.name, loc.line),
1430 Style::LineAndColumn,
1432 for _ in 0..max_line_num_len {
1433 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1440 sm.filename_for_diagnostics(&loc.file.name),
1441 sm.doctest_offset_line(&loc.file.name, loc.line),
1444 Style::LineAndColumn,
1447 } else if !self.short_message {
1448 // remember where we are in the output buffer for easy reference
1449 let buffer_msg_line_offset = buffer.num_lines();
1452 draw_col_separator_no_space(
1454 buffer_msg_line_offset,
1455 max_line_num_len + 1,
1458 // Then, the secondary file indicator
1459 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1460 let loc = if let Some(first_line) = annotated_file.lines.first() {
1461 let col = if let Some(first_annotation) = first_line.annotations.first() {
1462 format!(":{}", first_annotation.start_col + 1)
1468 sm.filename_for_diagnostics(&annotated_file.file.name),
1469 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1473 format!("{}", sm.filename_for_diagnostics(&annotated_file.file.name))
1475 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1476 for _ in 0..max_line_num_len {
1477 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1481 if !self.short_message {
1482 // Put in the spacer between the location and annotated source
1483 let buffer_msg_line_offset = buffer.num_lines();
1484 draw_col_separator_no_space(
1486 buffer_msg_line_offset,
1487 max_line_num_len + 1,
1490 // Contains the vertical lines' positions for active multiline annotations
1491 let mut multilines = FxHashMap::default();
1493 // Get the left-side margin to remove it
1494 let mut whitespace_margin = usize::MAX;
1495 for line_idx in 0..annotated_file.lines.len() {
1496 let file = annotated_file.file.clone();
1497 let line = &annotated_file.lines[line_idx];
1498 if let Some(source_string) = file.get_line(line.line_index - 1) {
1499 let leading_whitespace = source_string
1501 .take_while(|c| c.is_whitespace())
1504 // Tabs are displayed as 4 spaces
1510 if source_string.chars().any(|c| !c.is_whitespace()) {
1511 whitespace_margin = min(whitespace_margin, leading_whitespace);
1515 if whitespace_margin == usize::MAX {
1516 whitespace_margin = 0;
1519 // Left-most column any visible span points at.
1520 let mut span_left_margin = usize::MAX;
1521 for line in &annotated_file.lines {
1522 for ann in &line.annotations {
1523 span_left_margin = min(span_left_margin, ann.start_col);
1524 span_left_margin = min(span_left_margin, ann.end_col);
1527 if span_left_margin == usize::MAX {
1528 span_left_margin = 0;
1531 // Right-most column any visible span points at.
1532 let mut span_right_margin = 0;
1533 let mut label_right_margin = 0;
1534 let mut max_line_len = 0;
1535 for line in &annotated_file.lines {
1538 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1540 for ann in &line.annotations {
1541 span_right_margin = max(span_right_margin, ann.start_col);
1542 span_right_margin = max(span_right_margin, ann.end_col);
1543 // FIXME: account for labels not in the same line
1544 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1545 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1549 let width_offset = 3 + max_line_num_len;
1550 let code_offset = if annotated_file.multiline_depth == 0 {
1553 width_offset + annotated_file.multiline_depth + 1
1556 let column_width = if let Some(width) = self.diagnostic_width {
1557 width.saturating_sub(code_offset)
1558 } else if self.ui_testing {
1559 DEFAULT_COLUMN_WIDTH
1561 termize::dimensions()
1562 .map(|(w, _)| w.saturating_sub(code_offset))
1563 .unwrap_or(DEFAULT_COLUMN_WIDTH)
1566 let margin = Margin::new(
1575 // Next, output the annotate source for this file
1576 for line_idx in 0..annotated_file.lines.len() {
1577 let previous_buffer_line = buffer.num_lines();
1579 let depths = self.render_source_line(
1581 annotated_file.file.clone(),
1582 &annotated_file.lines[line_idx],
1588 let mut to_add = FxHashMap::default();
1590 for (depth, style) in depths {
1591 if multilines.remove(&depth).is_none() {
1592 to_add.insert(depth, style);
1596 // Set the multiline annotation vertical lines to the left of
1597 // the code in this line.
1598 for (depth, style) in &multilines {
1599 for line in previous_buffer_line..buffer.num_lines() {
1600 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1603 // check to see if we need to print out or elide lines that come between
1604 // this annotated line and the next one.
1605 if line_idx < (annotated_file.lines.len() - 1) {
1606 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1607 - annotated_file.lines[line_idx].line_index;
1608 if line_idx_delta > 2 {
1609 let last_buffer_line_num = buffer.num_lines();
1610 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1612 // Set the multiline annotation vertical lines on `...` bridging line.
1613 for (depth, style) in &multilines {
1614 draw_multiline_line(
1616 last_buffer_line_num,
1622 } else if line_idx_delta == 2 {
1623 let unannotated_line = annotated_file
1625 .get_line(annotated_file.lines[line_idx].line_index)
1626 .unwrap_or_else(|| Cow::from(""));
1628 let last_buffer_line_num = buffer.num_lines();
1632 &normalize_whitespace(&unannotated_line),
1633 annotated_file.lines[line_idx + 1].line_index - 1,
1634 last_buffer_line_num,
1640 for (depth, style) in &multilines {
1641 draw_multiline_line(
1643 last_buffer_line_num,
1652 multilines.extend(&to_add);
1657 // final step: take our styled buffer, render it, then output it
1658 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1663 fn emit_suggestion_default(
1666 suggestion: &CodeSuggestion,
1667 args: &FluentArgs<'_>,
1669 max_line_num_len: usize,
1670 ) -> io::Result<()> {
1671 let Some(ref sm) = self.sm else {
1675 // Render the replacements for each suggestion
1676 let suggestions = suggestion.splice_lines(&**sm);
1677 debug!("emit_suggestion_default: suggestions={:?}", suggestions);
1679 if suggestions.is_empty() {
1680 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1681 // approach to avoid ICEs by ignoring the suggestion outright.
1685 let mut buffer = StyledBuffer::new();
1687 // Render the suggestion message
1688 buffer.append(0, level.to_str(), Style::Level(*level));
1689 buffer.append(0, ": ", Style::HeaderMsg);
1693 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1697 Some(Style::HeaderMsg),
1700 let mut row_num = 2;
1701 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1702 let mut notice_capitalization = false;
1703 for (complete, parts, highlights, only_capitalization) in
1704 suggestions.iter().take(MAX_SUGGESTIONS)
1706 notice_capitalization |= only_capitalization;
1708 let has_deletion = parts.iter().any(|p| p.is_deletion());
1709 let is_multiline = complete.lines().count() > 1;
1711 if let Some(span) = span.primary_span() {
1712 // Compare the primary span of the diagnostic with the span of the suggestion
1713 // being emitted. If they belong to the same file, we don't *need* to show the
1714 // file name, saving in verbosity, but if it *isn't* we do need it, otherwise we're
1715 // telling users to make a change but not clarifying *where*.
1716 let loc = sm.lookup_char_pos(parts[0].span.lo());
1717 if loc.file.name != sm.span_to_filename(span) && loc.file.name.is_real() {
1718 buffer.puts(row_num - 1, 0, "--> ", Style::LineNumber);
1723 sm.filename_for_diagnostics(&loc.file.name),
1724 sm.doctest_offset_line(&loc.file.name, loc.line),
1727 Style::LineAndColumn,
1729 for _ in 0..max_line_num_len {
1730 buffer.prepend(row_num - 1, " ", Style::NoStyle);
1735 let show_code_change = if has_deletion && !is_multiline {
1736 DisplaySuggestion::Diff
1737 } else if (parts.len() != 1 || parts[0].snippet.trim() != complete.trim())
1740 DisplaySuggestion::Underline
1742 DisplaySuggestion::None
1745 if let DisplaySuggestion::Diff = show_code_change {
1750 .span_to_lines(parts[0].span)
1751 .expect("span_to_lines failed when emitting suggestion");
1753 assert!(!file_lines.lines.is_empty() || parts[0].span.is_dummy());
1755 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1756 draw_col_separator_no_space(&mut buffer, row_num - 1, max_line_num_len + 1);
1757 let mut lines = complete.lines();
1758 if lines.clone().next().is_none() {
1759 // Account for a suggestion to completely remove a line(s) with whitespace (#94192).
1760 let line_end = sm.lookup_char_pos(parts[0].span.hi()).line;
1761 for line in line_start..=line_end {
1763 row_num - 1 + line - line_start,
1765 &self.maybe_anonymized(line),
1769 row_num - 1 + line - line_start,
1770 max_line_num_len + 1,
1775 row_num - 1 + line - line_start,
1776 max_line_num_len + 3,
1777 &normalize_whitespace(&*file_lines.file.get_line(line - 1).unwrap()),
1781 row_num += line_end - line_start;
1783 let mut unhighlighted_lines = Vec::new();
1784 for (line_pos, (line, highlight_parts)) in lines.by_ref().zip(highlights).enumerate() {
1785 debug!(%line_pos, %line, ?highlight_parts);
1787 // Remember lines that are not highlighted to hide them if needed
1788 if highlight_parts.is_empty() {
1789 unhighlighted_lines.push((line_pos, line));
1793 match unhighlighted_lines.len() {
1795 // Since we show first line, "..." line and last line,
1796 // There is no reason to hide if there are 3 or less lines
1797 // (because then we just replace a line with ... which is
1799 n if n <= 3 => unhighlighted_lines.drain(..).for_each(|(p, l)| {
1800 self.draw_code_line(
1813 // Print first unhighlighted line, "..." and last unhighlighted line, like so:
1815 // LL | this line was highlighted
1816 // LL | this line is just for context
1818 // LL | this line is just for context
1819 // LL | this line was highlighted
1821 let last_line = unhighlighted_lines.pop();
1822 let first_line = unhighlighted_lines.drain(..).next();
1824 first_line.map(|(p, l)| {
1825 self.draw_code_line(
1839 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1842 last_line.map(|(p, l)| {
1843 self.draw_code_line(
1859 self.draw_code_line(
1873 // This offset and the ones below need to be signed to account for replacement code
1874 // that is shorter than the original code.
1875 let mut offsets: Vec<(usize, isize)> = Vec::new();
1876 // Only show an underline in the suggestions if the suggestion is not the
1877 // entirety of the code being shown and the displayed code is not multiline.
1878 if let DisplaySuggestion::Diff | DisplaySuggestion::Underline = show_code_change {
1879 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1881 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1882 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1884 // Do not underline the leading...
1885 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1886 // ...or trailing spaces. Account for substitutions containing unicode
1888 let sub_len: usize = part
1892 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1895 let offset: isize = offsets
1898 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1901 let underline_start = (span_start_pos + start) as isize + offset;
1902 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1903 assert!(underline_start >= 0 && underline_end >= 0);
1904 let padding: usize = max_line_num_len + 3;
1905 for p in underline_start..underline_end {
1906 if let DisplaySuggestion::Underline = show_code_change {
1907 // If this is a replacement, underline with `^`, if this is an addition
1908 // underline with `+`.
1911 (padding as isize + p) as usize,
1912 if part.is_addition(&sm) { '+' } else { '~' },
1917 if let DisplaySuggestion::Diff = show_code_change {
1918 // Colorize removal with red in diff format.
1919 buffer.set_style_range(
1921 (padding as isize + span_start_pos as isize) as usize,
1922 (padding as isize + span_end_pos as isize) as usize,
1928 // length of the code after substitution
1929 let full_sub_len = part
1932 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1933 .sum::<usize>() as isize;
1935 // length of the code to be substituted
1936 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1937 // For multiple substitutions, use the position *after* the previous
1938 // substitutions have happened, only when further substitutions are
1939 // located strictly after.
1940 offsets.push((span_end_pos, full_sub_len - snippet_len));
1945 // if we elided some lines, add an ellipsis
1946 if lines.next().is_some() {
1947 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1948 } else if let DisplaySuggestion::None = show_code_change {
1949 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1953 if suggestions.len() > MAX_SUGGESTIONS {
1954 let others = suggestions.len() - MAX_SUGGESTIONS;
1955 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1956 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1957 } else if notice_capitalization {
1958 let msg = "notice the capitalization difference";
1959 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1961 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1965 fn emit_messages_default(
1968 message: &[(DiagnosticMessage, Style)],
1969 args: &FluentArgs<'_>,
1970 code: &Option<DiagnosticId>,
1972 children: &[SubDiagnostic],
1973 suggestions: &[CodeSuggestion],
1975 let max_line_num_len = if self.ui_testing {
1976 ANONYMIZED_LINE_NUM.len()
1978 let n = self.get_max_line_num(span, children);
1979 num_decimal_digits(n)
1982 match self.emit_message_default(span, message, args, code, level, max_line_num_len, false) {
1984 if !children.is_empty()
1985 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1987 let mut buffer = StyledBuffer::new();
1988 if !self.short_message {
1989 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1991 if let Err(e) = emit_to_destination(
1997 panic!("failed to emit error: {}", e)
2000 if !self.short_message {
2001 for child in children {
2002 let span = child.render_span.as_ref().unwrap_or(&child.span);
2003 if let Err(err) = self.emit_message_default(
2012 panic!("failed to emit error: {}", err);
2015 for sugg in suggestions {
2016 if sugg.style == SuggestionStyle::CompletelyHidden {
2017 // do not display this suggestion, it is meant only for tools
2018 } else if sugg.style == SuggestionStyle::HideCodeAlways {
2019 if let Err(e) = self.emit_message_default(
2021 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
2028 panic!("failed to emit error: {}", e);
2030 } else if let Err(e) = self.emit_suggestion_default(
2037 panic!("failed to emit error: {}", e);
2042 Err(e) => panic!("failed to emit error: {}", e),
2045 let mut dst = self.dst.writable();
2046 match writeln!(dst) {
2047 Err(e) => panic!("failed to emit error: {}", e),
2049 if let Err(e) = dst.flush() {
2050 panic!("failed to emit error: {}", e)
2058 buffer: &mut StyledBuffer,
2059 row_num: &mut usize,
2060 highlight_parts: &Vec<SubstitutionHighlight>,
2064 show_code_change: DisplaySuggestion,
2065 max_line_num_len: usize,
2066 file_lines: &FileLines,
2069 // Print the span column to avoid confusion
2070 buffer.puts(*row_num, 0, &self.maybe_anonymized(line_start + line_pos), Style::LineNumber);
2071 if let DisplaySuggestion::Diff = show_code_change {
2072 // Add the line number for both addition and removal to drive the point home.
2074 // N - fn foo<A: T>(bar: A) {
2075 // N + fn foo(bar: impl T) {
2079 &self.maybe_anonymized(line_start + line_pos),
2082 buffer.puts(*row_num - 1, max_line_num_len + 1, "- ", Style::Removal);
2085 max_line_num_len + 3,
2086 &normalize_whitespace(
2087 &*file_lines.file.get_line(file_lines.lines[line_pos].line_index).unwrap(),
2091 buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
2092 } else if is_multiline {
2093 match &highlight_parts[..] {
2094 [SubstitutionHighlight { start: 0, end }] if *end == line.len() => {
2095 buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
2098 draw_col_separator(buffer, *row_num, max_line_num_len + 1);
2101 buffer.puts(*row_num, max_line_num_len + 1, "~ ", Style::Addition);
2105 draw_col_separator(buffer, *row_num, max_line_num_len + 1);
2108 // print the suggestion
2109 buffer.append(*row_num, &normalize_whitespace(line), Style::NoStyle);
2111 // Colorize addition/replacements with green.
2112 for &SubstitutionHighlight { start, end } in highlight_parts {
2113 // Account for tabs when highlighting (#87972).
2114 let tabs: usize = line
2117 .map(|ch| match ch {
2122 buffer.set_style_range(
2124 max_line_num_len + 3 + start + tabs,
2125 max_line_num_len + 3 + end + tabs,
2134 #[derive(Clone, Copy)]
2135 enum DisplaySuggestion {
2141 impl FileWithAnnotatedLines {
2142 /// Preprocess all the annotations so that they are grouped by file and by line number
2143 /// This helps us quickly iterate over the whole message (including secondary file spans)
2144 pub fn collect_annotations(
2145 emitter: &dyn Emitter,
2146 args: &FluentArgs<'_>,
2148 ) -> Vec<FileWithAnnotatedLines> {
2149 fn add_annotation_to_file(
2150 file_vec: &mut Vec<FileWithAnnotatedLines>,
2151 file: Lrc<SourceFile>,
2155 for slot in file_vec.iter_mut() {
2156 // Look through each of our files for the one we're adding to
2157 if slot.file.name == file.name {
2158 // See if we already have a line for it
2159 for line_slot in &mut slot.lines {
2160 if line_slot.line_index == line_index {
2161 line_slot.annotations.push(ann);
2165 // We don't have a line yet, create one
2166 slot.lines.push(Line { line_index, annotations: vec![ann] });
2171 // This is the first time we're seeing the file
2172 file_vec.push(FileWithAnnotatedLines {
2174 lines: vec![Line { line_index, annotations: vec![ann] }],
2179 let mut output = vec![];
2180 let mut multiline_annotations = vec![];
2182 if let Some(ref sm) = emitter.source_map() {
2183 for span_label in msp.span_labels() {
2184 if span_label.span.is_dummy() {
2188 let lo = sm.lookup_char_pos(span_label.span.lo());
2189 let mut hi = sm.lookup_char_pos(span_label.span.hi());
2191 // Watch out for "empty spans". If we get a span like 6..6, we
2192 // want to just display a `^` at 6, so convert that to
2193 // 6..7. This is degenerate input, but it's best to degrade
2194 // gracefully -- and the parser likes to supply a span like
2195 // that for EOF, in particular.
2197 if lo.col_display == hi.col_display && lo.line == hi.line {
2198 hi.col_display += 1;
2201 if lo.line != hi.line {
2202 let ml = MultilineAnnotation {
2204 line_start: lo.line,
2206 start_col: lo.col_display,
2207 end_col: hi.col_display,
2208 is_primary: span_label.is_primary,
2212 .map(|m| emitter.translate_message(m, args).to_string()),
2213 overlaps_exactly: false,
2215 multiline_annotations.push((lo.file, ml));
2217 let ann = Annotation {
2218 start_col: lo.col_display,
2219 end_col: hi.col_display,
2220 is_primary: span_label.is_primary,
2224 .map(|m| emitter.translate_message(m, args).to_string()),
2225 annotation_type: AnnotationType::Singleline,
2227 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
2232 // Find overlapping multiline annotations, put them at different depths
2233 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
2234 for (_, ann) in multiline_annotations.clone() {
2235 for (_, a) in multiline_annotations.iter_mut() {
2236 // Move all other multiline annotations overlapping with this one
2237 // one level to the right.
2238 if !(ann.same_span(a))
2239 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
2242 } else if ann.same_span(a) && &ann != a {
2243 a.overlaps_exactly = true;
2250 let mut max_depth = 0; // max overlapping multiline spans
2251 for (file, ann) in multiline_annotations {
2252 max_depth = max(max_depth, ann.depth);
2253 let mut end_ann = ann.as_end();
2254 if !ann.overlaps_exactly {
2255 // avoid output like
2277 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
2278 // 4 is the minimum vertical length of a multiline span when presented: two lines
2279 // of code and two lines of underline. This is not true for the special case where
2280 // the beginning doesn't have an underline, but the current logic seems to be
2281 // working correctly.
2282 let middle = min(ann.line_start + 4, ann.line_end);
2283 for line in ann.line_start + 1..middle {
2284 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
2285 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
2287 let line_end = ann.line_end - 1;
2288 if middle < line_end {
2289 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
2292 end_ann.annotation_type = AnnotationType::Singleline;
2294 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
2296 for file_vec in output.iter_mut() {
2297 file_vec.multiline_depth = max_depth;
2303 // instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
2304 // we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
2305 // is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
2306 // This is also why we need the max number of decimal digits within a `usize`.
2307 fn num_decimal_digits(num: usize) -> usize {
2308 #[cfg(target_pointer_width = "64")]
2309 const MAX_DIGITS: usize = 20;
2311 #[cfg(target_pointer_width = "32")]
2312 const MAX_DIGITS: usize = 10;
2314 #[cfg(target_pointer_width = "16")]
2315 const MAX_DIGITS: usize = 5;
2318 for num_digits in 1..MAX_DIGITS {
2322 lim = lim.wrapping_mul(10);
2327 // We replace some characters so the CLI output is always consistent and underlines aligned.
2328 const OUTPUT_REPLACEMENTS: &[(char, &str)] = &[
2329 ('\t', " "), // We do our own tab replacement
2330 ('\u{200D}', ""), // Replace ZWJ with nothing for consistent terminal output of grapheme clusters.
2331 ('\u{202A}', ""), // The following unicode text flow control characters are inconsistently
2332 ('\u{202B}', ""), // supported across CLIs and can cause confusion due to the bytes on disk
2333 ('\u{202D}', ""), // not corresponding to the visible source code, so we replace them always.
2342 fn normalize_whitespace(str: &str) -> String {
2343 let mut s = str.to_string();
2344 for (c, replacement) in OUTPUT_REPLACEMENTS {
2345 s = s.replace(*c, replacement);
2350 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2351 buffer.puts(line, col, "| ", Style::LineNumber);
2354 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
2355 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
2358 fn draw_col_separator_no_space_with_style(
2359 buffer: &mut StyledBuffer,
2364 buffer.putc(line, col, '|', style);
2368 buffer: &mut StyledBuffer,
2375 for col in col_from..col_to {
2376 buffer.putc(line, col, symbol, style);
2380 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2381 buffer.puts(line, col, "= ", Style::LineNumber);
2384 fn draw_multiline_line(
2385 buffer: &mut StyledBuffer,
2391 buffer.putc(line, offset + depth - 1, '|', style);
2401 let extra = if inclusive { 1 } else { 0 };
2402 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
2404 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
2405 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
2408 fn emit_to_destination(
2409 rendered_buffer: &[Vec<StyledString>],
2411 dst: &mut Destination,
2412 short_message: bool,
2413 ) -> io::Result<()> {
2416 let mut dst = dst.writable();
2418 // In order to prevent error message interleaving, where multiple error lines get intermixed
2419 // when multiple compiler processes error simultaneously, we emit errors with additional
2422 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
2423 // the .flush() is called we take the buffer created from the buffered writes and write it at
2424 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
2425 // scheme, this buffered approach works and maintains the styling.
2427 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
2428 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
2429 // enough to output the full error message, then we release.
2430 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
2431 for (pos, line) in rendered_buffer.iter().enumerate() {
2433 dst.apply_style(*lvl, part.style)?;
2434 write!(dst, "{}", part.text)?;
2437 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2445 pub enum Destination {
2446 Terminal(StandardStream),
2447 Buffered(BufferWriter),
2448 // The bool denotes whether we should be emitting ansi color codes or not
2449 Raw(Box<(dyn Write + Send)>, bool),
2452 pub enum WritableDst<'a> {
2453 Terminal(&'a mut StandardStream),
2454 Buffered(&'a mut BufferWriter, Buffer),
2455 Raw(&'a mut (dyn Write + Send)),
2456 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2460 fn from_stderr(color: ColorConfig) -> Destination {
2461 let choice = color.to_color_choice();
2462 // On Windows we'll be performing global synchronization on the entire
2463 // system for emitting rustc errors, so there's no need to buffer
2466 // On non-Windows we rely on the atomicity of `write` to ensure errors
2467 // don't get all jumbled up.
2469 Terminal(StandardStream::stderr(choice))
2471 Buffered(BufferWriter::stderr(choice))
2475 fn writable(&mut self) -> WritableDst<'_> {
2477 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2478 Destination::Buffered(ref mut t) => {
2479 let buf = t.buffer();
2480 WritableDst::Buffered(t, buf)
2482 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2483 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2487 fn supports_color(&self) -> bool {
2489 Self::Terminal(ref stream) => stream.supports_color(),
2490 Self::Buffered(ref buffer) => buffer.buffer().supports_color(),
2491 Self::Raw(_, supports_color) => supports_color,
2496 impl<'a> WritableDst<'a> {
2497 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2498 let mut spec = ColorSpec::new();
2500 Style::Addition => {
2501 spec.set_fg(Some(Color::Green)).set_intense(true);
2504 spec.set_fg(Some(Color::Red)).set_intense(true);
2506 Style::LineAndColumn => {}
2507 Style::LineNumber => {
2508 spec.set_bold(true);
2509 spec.set_intense(true);
2511 spec.set_fg(Some(Color::Cyan));
2513 spec.set_fg(Some(Color::Blue));
2516 Style::Quotation => {}
2517 Style::MainHeaderMsg => {
2518 spec.set_bold(true);
2520 spec.set_intense(true).set_fg(Some(Color::White));
2523 Style::UnderlinePrimary | Style::LabelPrimary => {
2525 spec.set_bold(true);
2527 Style::UnderlineSecondary | Style::LabelSecondary => {
2528 spec.set_bold(true).set_intense(true);
2530 spec.set_fg(Some(Color::Cyan));
2532 spec.set_fg(Some(Color::Blue));
2535 Style::HeaderMsg | Style::NoStyle => {}
2536 Style::Level(lvl) => {
2538 spec.set_bold(true);
2540 Style::Highlight => {
2541 spec.set_bold(true);
2544 self.set_color(&spec)
2547 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2549 WritableDst::Terminal(ref mut t) => t.set_color(color),
2550 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2551 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2552 WritableDst::Raw(_) => Ok(()),
2556 fn reset(&mut self) -> io::Result<()> {
2558 WritableDst::Terminal(ref mut t) => t.reset(),
2559 WritableDst::Buffered(_, ref mut t) => t.reset(),
2560 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2561 WritableDst::Raw(_) => Ok(()),
2566 impl<'a> Write for WritableDst<'a> {
2567 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2569 WritableDst::Terminal(ref mut t) => t.write(bytes),
2570 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2571 WritableDst::Raw(ref mut w) => w.write(bytes),
2572 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2576 fn flush(&mut self) -> io::Result<()> {
2578 WritableDst::Terminal(ref mut t) => t.flush(),
2579 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2580 WritableDst::Raw(ref mut w) => w.flush(),
2581 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2586 impl<'a> Drop for WritableDst<'a> {
2587 fn drop(&mut self) {
2588 if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
2589 drop(dst.print(buf));
2594 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2595 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2596 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2597 let found = match sm.span_to_snippet(sp) {
2598 Ok(snippet) => snippet,
2600 warn!(error = ?e, "Invalid span {:?}", sp);
2604 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2605 // All the chars that differ in capitalization are confusable (above):
2606 let confusable = iter::zip(found.chars(), suggested.chars())
2607 .filter(|(f, s)| f != s)
2608 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2609 confusable && found.to_lowercase() == suggested.to_lowercase()
2610 // FIXME: We sometimes suggest the same thing we already have, which is a
2611 // bug, but be defensive against that here.
2612 && found != suggested