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 `librustc::session::config::ErrorOutputType`.
12 use rustc_span::source_map::SourceMap;
13 use rustc_span::{MultiSpan, SourceFile, Span};
15 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
16 use crate::styled_buffer::StyledBuffer;
17 use crate::Level::Error;
19 pluralize, CodeSuggestion, Diagnostic, DiagnosticId, Level, SubDiagnostic, SuggestionStyle,
22 use rustc_data_structures::fx::FxHashMap;
23 use rustc_data_structures::sync::Lrc;
24 use rustc_span::hygiene::{ExpnKind, MacroKind};
26 use std::cmp::{max, min, Reverse};
28 use std::io::prelude::*;
30 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
31 use termcolor::{Buffer, Color, WriteColor};
33 /// Describes the way the content of the `rendered` field of the json output is generated
34 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
35 pub enum HumanReadableErrorType {
37 AnnotateSnippet(ColorConfig),
41 impl HumanReadableErrorType {
42 /// Returns a (`short`, `color`) tuple
43 pub fn unzip(self) -> (bool, ColorConfig) {
45 HumanReadableErrorType::Default(cc) => (false, cc),
46 HumanReadableErrorType::Short(cc) => (true, cc),
47 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
52 dst: Box<dyn Write + Send>,
53 source_map: Option<Lrc<SourceMap>>,
55 terminal_width: Option<usize>,
56 external_macro_backtrace: bool,
58 let (short, color_config) = self.unzip();
59 let color = color_config.suggests_using_colors();
67 external_macro_backtrace,
72 #[derive(Clone, Copy, Debug)]
74 /// The available whitespace in the left that can be consumed when centering.
75 pub whitespace_left: usize,
76 /// The column of the beginning of left-most span.
78 /// The column of the end of right-most span.
79 pub span_right: usize,
80 /// The beginning of the line to be displayed.
81 pub computed_left: usize,
82 /// The end of the line to be displayed.
83 pub computed_right: usize,
84 /// The current width of the terminal. 140 by default and in tests.
85 pub column_width: usize,
86 /// The end column of a span label, including the span. Doesn't account for labels not in the
87 /// same line as the span.
88 pub label_right: usize,
93 whitespace_left: usize,
100 // The 6 is padding to give a bit of room for `...` when displaying:
105 // 16 | ... fn foo(self) -> Self::Bar {
110 whitespace_left: whitespace_left.saturating_sub(6),
111 span_left: span_left.saturating_sub(6),
112 span_right: span_right + 6,
116 label_right: label_right + 6,
118 m.compute(max_line_len);
122 fn was_cut_left(&self) -> bool {
123 self.computed_left > 0
126 fn was_cut_right(&self, line_len: usize) -> bool {
128 if self.computed_right == self.span_right || self.computed_right == self.label_right {
129 // Account for the "..." padding given above. Otherwise we end up with code lines that
130 // do fit but end in "..." as if they were trimmed.
131 self.computed_right - 6
135 right < line_len && self.computed_left + self.column_width < line_len
138 fn compute(&mut self, max_line_len: usize) {
139 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
140 self.computed_left = if self.whitespace_left > 20 {
141 self.whitespace_left - 16 // We want some padding.
145 // We want to show as much as possible, max_line_len is the right-most boundary for the
147 self.computed_right = max(max_line_len, self.computed_left);
149 if self.computed_right - self.computed_left > self.column_width {
150 // Trimming only whitespace isn't enough, let's get craftier.
151 if self.label_right - self.whitespace_left <= self.column_width {
152 // Attempt to fit the code window only trimming whitespace.
153 self.computed_left = self.whitespace_left;
154 self.computed_right = self.computed_left + self.column_width;
155 } else if self.label_right - self.span_left <= self.column_width {
156 // Attempt to fit the code window considering only the spans and labels.
157 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
158 self.computed_left = self.span_left.saturating_sub(padding_left);
159 self.computed_right = self.computed_left + self.column_width;
160 } else if self.span_right - self.span_left <= self.column_width {
161 // Attempt to fit the code window considering the spans and labels plus padding.
162 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
163 self.computed_left = self.span_left.saturating_sub(padding_left);
164 self.computed_right = self.computed_left + self.column_width;
166 // Mostly give up but still don't show the full line.
167 self.computed_left = self.span_left;
168 self.computed_right = self.span_right;
173 fn left(&self, line_len: usize) -> usize {
174 min(self.computed_left, line_len)
177 fn right(&self, line_len: usize) -> usize {
178 if line_len.saturating_sub(self.computed_left) <= self.column_width {
181 min(line_len, self.computed_right)
186 const ANONYMIZED_LINE_NUM: &str = "LL";
188 /// Emitter trait for emitting errors.
190 /// Emit a structured diagnostic.
191 fn emit_diagnostic(&mut self, diag: &Diagnostic);
193 /// Emit a notification that an artifact has been output.
194 /// This is currently only supported for the JSON format,
195 /// other formats can, and will, simply ignore it.
196 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
198 /// Checks if should show explanations about "rustc --explain"
199 fn should_show_explain(&self) -> bool {
203 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
205 /// Formats the substitutions of the primary_span
207 /// The are a lot of conditions to this method, but in short:
209 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
210 /// we format the `help` suggestion depending on the content of the
211 /// substitutions. In that case, we return the modified span only.
213 /// * If the current `Diagnostic` has multiple suggestions,
214 /// we return the original `primary_span` and the original suggestions.
215 fn primary_span_formatted<'a>(
217 diag: &'a Diagnostic,
218 ) -> (MultiSpan, &'a [CodeSuggestion]) {
219 let mut primary_span = diag.span.clone();
220 if let Some((sugg, rest)) = diag.suggestions.split_first() {
221 if rest.is_empty() &&
222 // ^ if there is only one suggestion
223 // don't display multi-suggestions as labels
224 sugg.substitutions.len() == 1 &&
225 // don't display multipart suggestions as labels
226 sugg.substitutions[0].parts.len() == 1 &&
227 // don't display long messages as labels
228 sugg.msg.split_whitespace().count() < 10 &&
229 // don't display multiline suggestions as labels
230 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
232 // when this style is set we want the suggestion to be a message, not inline
233 SuggestionStyle::HideCodeAlways,
234 // trivial suggestion for tooling's sake, never shown
235 SuggestionStyle::CompletelyHidden,
236 // subtle suggestion, never shown inline
237 SuggestionStyle::ShowAlways,
238 ].contains(&sugg.style)
240 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
241 let msg = if substitution.len() == 0 || sugg.style.hide_inline() {
242 // This substitution is only removal OR we explicitly don't want to show the
243 // code inline (`hide_inline`). Therefore, we don't show the substitution.
244 format!("help: {}", sugg.msg)
246 // Show the default suggestion text with the substitution
252 .map(|sm| is_case_difference(
255 sugg.substitutions[0].parts[0].span,
259 " (notice the capitalization)"
266 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
268 // We return only the modified primary_span
271 // if there are multiple suggestions, print them all in full
272 // to be consistent. We could try to figure out if we can
273 // make one (or the first one) inline, but that would give
274 // undue importance to a semi-random suggestion
275 (primary_span, &diag.suggestions)
278 (primary_span, &diag.suggestions)
282 // This does a small "fix" for multispans by looking to see if it can find any that
283 // point directly at <*macros>. Since these are often difficult to read, this
284 // will change the span to point at the use site.
285 fn fix_multispans_in_std_macros(
287 source_map: &Option<Lrc<SourceMap>>,
288 span: &mut MultiSpan,
289 children: &mut Vec<SubDiagnostic>,
293 let mut spans_updated = self.fix_multispan_in_std_macros(source_map, span, backtrace);
294 for child in children.iter_mut() {
296 self.fix_multispan_in_std_macros(source_map, &mut child.span, backtrace);
298 let msg = if level == &Error {
299 "this error originates in a macro outside of the current crate \
300 (in Nightly builds, run with -Z external-macro-backtrace \
304 "this warning originates in a macro outside of the current crate \
305 (in Nightly builds, run with -Z external-macro-backtrace \
311 children.push(SubDiagnostic {
313 message: vec![(msg, Style::NoStyle)],
314 span: MultiSpan::new(),
320 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
321 // <*macros>. Since these locations are often difficult to read, we move these Spans from
322 // <*macros> to their corresponding use site.
323 fn fix_multispan_in_std_macros(
325 source_map: &Option<Lrc<SourceMap>>,
326 span: &mut MultiSpan,
327 always_backtrace: bool,
329 let sm = match source_map {
331 None => return false,
334 let mut before_after: Vec<(Span, Span)> = vec![];
335 let mut new_labels: Vec<(Span, String)> = vec![];
337 // First, find all the spans in <*macros> and point instead at their use site
338 for sp in span.primary_spans() {
342 let call_sp = sm.call_span_if_macro(*sp);
343 if call_sp != *sp && !always_backtrace {
344 before_after.push((*sp, call_sp));
346 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
347 let backtrace_len = macro_backtrace.len();
348 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
349 // Only show macro locations that are local
350 // and display them like a span_note
351 if trace.def_site.is_dummy() {
354 if always_backtrace {
358 "in this expansion of `{}`{}",
360 if backtrace_len > 2 {
361 // if backtrace_len == 1 it'll be pointed
362 // at by "in this macro invocation"
363 format!(" (#{})", i + 1)
370 // Check to make sure we're not in any <*macros>
371 if !sm.span_to_filename(trace.def_site).is_macros()
372 && matches!(trace.kind, ExpnKind::Macro(MacroKind::Bang, _))
378 "in this macro invocation{}",
379 if backtrace_len > 2 && always_backtrace {
380 // only specify order when the macro
381 // backtrace is multiple levels deep
382 format!(" (#{})", i + 1)
388 if !always_backtrace {
394 for (label_span, label_text) in new_labels {
395 span.push_span_label(label_span, label_text);
397 for sp_label in span.span_labels() {
398 if sp_label.span.is_dummy() {
401 if sm.span_to_filename(sp_label.span.clone()).is_macros() && !always_backtrace {
402 if let Some(use_site) = sp_label.span.macro_backtrace().last() {
403 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
407 // After we have them, make sure we replace these 'bad' def sites with their use sites
408 let spans_updated = !before_after.is_empty();
409 for (before, after) in before_after {
410 span.replace(before, after);
417 impl Emitter for EmitterWriter {
418 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
422 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
423 let mut children = diag.children.clone();
424 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
426 self.fix_multispans_in_std_macros(
431 self.external_macro_backtrace,
434 self.emit_messages_default(
436 &diag.styled_message(),
444 fn should_show_explain(&self) -> bool {
449 /// An emitter that does nothing when emitting a diagnostic.
450 pub struct SilentEmitter;
452 impl Emitter for SilentEmitter {
453 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
456 fn emit_diagnostic(&mut self, _: &Diagnostic) {}
459 /// Maximum number of lines we will print for each error; arbitrary.
460 pub const MAX_HIGHLIGHT_LINES: usize = 6;
461 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
463 /// This should be replaced with a more involved mechanism to output multiline suggestions that
464 /// more closely mimmics the regular diagnostic output, where irrelevant code lines are elided.
465 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
466 /// Maximum number of suggestions to be shown
468 /// Arbitrary, but taken from trait import suggestion limit
469 pub const MAX_SUGGESTIONS: usize = 4;
471 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
472 pub enum ColorConfig {
479 fn to_color_choice(self) -> ColorChoice {
481 ColorConfig::Always => {
482 if atty::is(atty::Stream::Stderr) {
485 ColorChoice::AlwaysAnsi
488 ColorConfig::Never => ColorChoice::Never,
489 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
490 ColorConfig::Auto => ColorChoice::Never,
493 fn suggests_using_colors(self) -> bool {
495 ColorConfig::Always | ColorConfig::Auto => true,
496 ColorConfig::Never => false,
501 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
502 pub struct EmitterWriter {
504 sm: Option<Lrc<SourceMap>>,
508 terminal_width: Option<usize>,
510 external_macro_backtrace: bool,
514 pub struct FileWithAnnotatedLines {
515 pub file: Lrc<SourceFile>,
516 pub lines: Vec<Line>,
517 multiline_depth: usize,
522 color_config: ColorConfig,
523 source_map: Option<Lrc<SourceMap>>,
526 terminal_width: Option<usize>,
527 external_macro_backtrace: bool,
529 let dst = Destination::from_stderr(color_config);
537 external_macro_backtrace,
542 dst: Box<dyn Write + Send>,
543 source_map: Option<Lrc<SourceMap>>,
547 terminal_width: Option<usize>,
548 external_macro_backtrace: bool,
551 dst: Raw(dst, colored),
557 external_macro_backtrace,
561 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
562 self.ui_testing = ui_testing;
566 fn maybe_anonymized(&self, line_num: usize) -> String {
567 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
572 buffer: &mut StyledBuffer,
580 let line_len = source_string.len();
581 // Create the source line we will highlight.
582 let left = margin.left(line_len);
583 let right = margin.right(line_len);
584 // On long lines, we strip the source line, accounting for unicode.
586 let code: String = source_string
590 // Make sure that the trimming on the right will fall within the terminal width.
591 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
592 // For now, just accept that sometimes the code line will be longer than desired.
593 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
594 if taken + next > right - left {
601 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
602 if margin.was_cut_left() {
603 // We have stripped some code/whitespace from the beginning, make it clear.
604 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
606 if margin.was_cut_right(line_len) {
607 // We have stripped some code after the right-most span end, make it clear we did so.
608 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
610 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
612 draw_col_separator(buffer, line_offset, width_offset - 2);
615 fn render_source_line(
617 buffer: &mut StyledBuffer,
618 file: Lrc<SourceFile>,
623 ) -> Vec<(usize, Style)> {
629 // | secondary span label
631 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
633 // | | | actual code found in your source code and the spans we use to mark it
634 // | | when there's too much wasted space to the left, trim it
635 // | vertical divider between the column number and the code
638 if line.line_index == 0 {
642 let source_string = match file.get_line(line.line_index - 1) {
644 None => return Vec::new(),
647 let line_offset = buffer.num_lines();
649 let left = margin.left(source_string.len()); // Left trim
650 // Account for unicode characters of width !=0 that were removed.
651 let left = source_string
654 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
667 // Special case when there's only one annotation involved, it is the start of a multiline
668 // span and there's no text at the beginning of the code line. Instead of doing the whole
677 // we simplify the output to:
683 if let [ann] = &line.annotations[..] {
684 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
685 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
686 let style = if ann.is_primary {
687 Style::UnderlinePrimary
689 Style::UnderlineSecondary
691 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
692 return vec![(depth, style)];
697 // We want to display like this:
699 // vec.push(vec.pop().unwrap());
700 // --- ^^^ - previous borrow ends here
702 // | error occurs here
703 // previous borrow of `vec` occurs here
705 // But there are some weird edge cases to be aware of:
707 // vec.push(vec.pop().unwrap());
708 // -------- - previous borrow ends here
710 // |this makes no sense
711 // previous borrow of `vec` occurs here
713 // For this reason, we group the lines into "highlight lines"
714 // and "annotations lines", where the highlight lines have the `^`.
716 // Sort the annotations by (start, end col)
717 // The labels are reversed, sort and then reversed again.
718 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
719 // the letter signifies the span. Here we are only sorting by the
720 // span and hence, the order of the elements with the same span will
721 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
722 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
723 // still ordered first to last, but all the elements with different
724 // spans are ordered by their spans in last to first order. Last to
725 // first order is important, because the jiggly lines and | are on
726 // the left, so the rightmost span needs to be rendered first,
727 // otherwise the lines would end up needing to go over a message.
729 let mut annotations = line.annotations.clone();
730 annotations.sort_by_key(|a| Reverse(a.start_col));
732 // First, figure out where each label will be positioned.
734 // In the case where you have the following annotations:
736 // vec.push(vec.pop().unwrap());
737 // -------- - previous borrow ends here [C]
739 // |this makes no sense [B]
740 // previous borrow of `vec` occurs here [A]
742 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
744 // We try, when possible, to stick the rightmost annotation at the end
745 // of the highlight line:
747 // vec.push(vec.pop().unwrap());
748 // --- --- - previous borrow ends here
750 // But sometimes that's not possible because one of the other
751 // annotations overlaps it. For example, from the test
752 // `span_overlap_label`, we have the following annotations
753 // (written on distinct lines for clarity):
759 // In this case, we can't stick the rightmost-most label on
760 // the highlight line, or we would get:
767 // which is totally weird. Instead we want:
775 // which is...less weird, at least. In fact, in general, if
776 // the rightmost span overlaps with any other span, we should
777 // use the "hang below" version, so we can at least make it
778 // clear where the span *starts*. There's an exception for this
779 // logic, when the labels do not have a message:
794 let mut annotations_position = vec![];
795 let mut line_len = 0;
797 for (i, annotation) in annotations.iter().enumerate() {
798 for (j, next) in annotations.iter().enumerate() {
799 if overlaps(next, annotation, 0) // This label overlaps with another one and both
800 && annotation.has_label() // take space (they have text and are not
801 && j > i // multiline lines).
803 // We're currently on the first line, move the label one line down
805 // If we're overlapping with an un-labelled annotation with the same span
806 // we can just merge them in the output
807 if next.start_col == annotation.start_col
808 && next.end_col == annotation.end_col
814 // This annotation needs a new line in the output.
819 annotations_position.push((p, annotation));
820 for (j, next) in annotations.iter().enumerate() {
822 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
823 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
824 // line if they overlap including padding, to
825 // avoid situations like:
832 && annotation.has_label() // Both labels must have some text, otherwise
833 && next.has_label()) // they are not overlapping.
834 // Do not add a new line if this annotation
835 // or the next are vertical line placeholders.
836 || (annotation.takes_space() // If either this or the next annotation is
837 && next.has_label()) // multiline start/end, move it to a new line
838 || (annotation.has_label() // so as not to overlap the orizontal lines.
839 && next.takes_space())
840 || (annotation.takes_space() && next.takes_space())
841 || (overlaps(next, annotation, l)
842 && next.end_col <= annotation.end_col
847 // This annotation needs a new line in the output.
853 line_len = max(line_len, p);
860 // If there are no annotations or the only annotations on this line are
861 // MultilineLine, then there's only code being shown, stop processing.
862 if line.annotations.iter().all(|a| a.is_line()) {
866 // Write the column separator.
868 // After this we will have:
877 for pos in 0..=line_len {
878 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
879 buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber);
882 // Write the horizontal lines for multiline annotations
883 // (only the first and last lines need this).
885 // After this we will have:
894 for &(pos, annotation) in &annotations_position {
895 let style = if annotation.is_primary {
896 Style::UnderlinePrimary
898 Style::UnderlineSecondary
901 match annotation.annotation_type {
902 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
907 width_offset + depth,
908 code_offset + annotation.start_col - left,
913 buffer.set_style_range(
915 code_offset + annotation.start_col - left,
916 code_offset + annotation.end_col - left,
918 annotation.is_primary,
925 // Write the vertical lines for labels that are on a different line as the underline.
927 // After this we will have:
936 for &(pos, annotation) in &annotations_position {
937 let style = if annotation.is_primary {
938 Style::UnderlinePrimary
940 Style::UnderlineSecondary
944 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
945 for p in line_offset + 1..=line_offset + pos {
948 (code_offset + annotation.start_col).saturating_sub(left),
954 match annotation.annotation_type {
955 AnnotationType::MultilineStart(depth) => {
956 for p in line_offset + pos + 1..line_offset + line_len + 2 {
957 buffer.putc(p, width_offset + depth - 1, '|', style);
960 AnnotationType::MultilineEnd(depth) => {
961 for p in line_offset..=line_offset + pos {
962 buffer.putc(p, width_offset + depth - 1, '|', style);
969 // Write the labels on the annotations that actually have a label.
971 // After this we will have:
976 // | something about `foo`
980 for &(pos, annotation) in &annotations_position {
982 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
983 let (pos, col) = if pos == 0 {
984 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
986 (pos + 2, annotation.start_col.saturating_sub(left))
988 if let Some(ref label) = annotation.label {
989 buffer.puts(line_offset + pos, code_offset + col, &label, style);
993 // Sort from biggest span to smallest span so that smaller spans are
994 // represented in the output:
999 // | | something about `foo`
1000 // | something about `fn foo()`
1001 annotations_position.sort_by_key(|(_, ann)| {
1002 // Decreasing order. When annotations share the same length, prefer `Primary`.
1003 (Reverse(ann.len()), ann.is_primary)
1006 // Write the underlines.
1008 // After this we will have:
1013 // | something about `foo`
1017 for &(_, annotation) in &annotations_position {
1018 let (underline, style) = if annotation.is_primary {
1019 ('^', Style::UnderlinePrimary)
1021 ('-', Style::UnderlineSecondary)
1023 for p in annotation.start_col..annotation.end_col {
1026 (code_offset + p).saturating_sub(left),
1032 annotations_position
1034 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1035 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1036 let style = if annotation.is_primary {
1039 Style::LabelSecondary
1045 .collect::<Vec<_>>()
1048 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1049 let sm = match self.sm {
1055 for primary_span in msp.primary_spans() {
1056 if !primary_span.is_dummy() {
1057 let hi = sm.lookup_char_pos(primary_span.hi());
1058 max = (hi.line).max(max);
1061 if !self.short_message {
1062 for span_label in msp.span_labels() {
1063 if !span_label.span.is_dummy() {
1064 let hi = sm.lookup_char_pos(span_label.span.hi());
1065 max = (hi.line).max(max);
1073 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1074 let primary = self.get_multispan_max_line_num(span);
1077 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1083 /// Adds a left margin to every line but the first, given a padding length and the label being
1084 /// displayed, keeping the provided highlighting.
1087 buffer: &mut StyledBuffer,
1088 msg: &[(String, Style)],
1091 override_style: Option<Style>,
1093 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1096 // --> file.rs:13:20
1101 // = note: multiline
1106 // | | length of label
1108 // `max_line_num_len`
1109 let padding = " ".repeat(padding + label.len() + 5);
1111 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1112 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1113 match (style, override_) {
1114 (Style::NoStyle, Some(override_)) => override_,
1119 let mut line_number = 0;
1121 // Provided the following diagnostic message:
1125 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1126 // ("looks", Style::Highlight),
1127 // ("with\nvery ", Style::NoStyle),
1128 // ("weird", Style::Highlight),
1129 // (" formats\n", Style::NoStyle),
1130 // ("see?", Style::Highlight),
1133 // the expected output on a note is (* surround the highlighted text)
1135 // = note: highlighted multiline
1137 // see how it *looks* with
1138 // very *weird* formats
1140 for &(ref text, ref style) in msg.iter() {
1141 let lines = text.split('\n').collect::<Vec<_>>();
1142 if lines.len() > 1 {
1143 for (i, line) in lines.iter().enumerate() {
1146 buffer.append(line_number, &padding, Style::NoStyle);
1148 buffer.append(line_number, line, style_or_override(*style, override_style));
1151 buffer.append(line_number, text, style_or_override(*style, override_style));
1156 fn emit_message_default(
1159 msg: &[(String, Style)],
1160 code: &Option<DiagnosticId>,
1162 max_line_num_len: usize,
1164 ) -> io::Result<()> {
1165 let mut buffer = StyledBuffer::new();
1166 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1168 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1170 // This is a secondary message with no span info
1171 for _ in 0..max_line_num_len {
1172 buffer.prepend(0, " ", Style::NoStyle);
1174 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1175 if *level != Level::FailureNote {
1176 let level_str = level.to_string();
1177 if !level_str.is_empty() {
1178 buffer.append(0, &level_str, Style::MainHeaderMsg);
1179 buffer.append(0, ": ", Style::NoStyle);
1182 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1184 let level_str = level.to_string();
1185 // The failure note level itself does not provide any useful diagnostic information
1186 if *level != Level::FailureNote && !level_str.is_empty() {
1187 buffer.append(0, &level_str, Style::Level(level.clone()));
1189 // only render error codes, not lint codes
1190 if let Some(DiagnosticId::Error(ref code)) = *code {
1191 buffer.append(0, "[", Style::Level(level.clone()));
1192 buffer.append(0, &code, Style::Level(level.clone()));
1193 buffer.append(0, "]", Style::Level(level.clone()));
1195 if *level != Level::FailureNote && !level_str.is_empty() {
1196 buffer.append(0, ": ", header_style);
1198 for &(ref text, _) in msg.iter() {
1199 buffer.append(0, text, header_style);
1203 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1205 // Make sure our primary file comes first
1206 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1207 (self.sm.as_ref(), msp.primary_span().as_ref())
1209 if !primary_span.is_dummy() {
1210 (sm.lookup_char_pos(primary_span.lo()), sm)
1212 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1216 // If we don't have span information, emit and exit
1217 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1221 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1223 annotated_files.swap(0, pos);
1226 // Print out the annotate source lines that correspond with the error
1227 for annotated_file in annotated_files {
1228 // we can't annotate anything if the source is unavailable.
1229 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1233 // print out the span location and spacer before we print the annotated source
1234 // to do this, we need to know if this span will be primary
1235 let is_primary = primary_lo.file.name == annotated_file.file.name;
1237 let loc = primary_lo.clone();
1238 if !self.short_message {
1239 // remember where we are in the output buffer for easy reference
1240 let buffer_msg_line_offset = buffer.num_lines();
1242 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1244 buffer_msg_line_offset,
1248 sm.doctest_offset_line(&loc.file.name, loc.line),
1251 Style::LineAndColumn,
1253 for _ in 0..max_line_num_len {
1254 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1262 sm.doctest_offset_line(&loc.file.name, loc.line),
1265 Style::LineAndColumn,
1268 } else if !self.short_message {
1269 // remember where we are in the output buffer for easy reference
1270 let buffer_msg_line_offset = buffer.num_lines();
1273 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1275 // Then, the secondary file indicator
1276 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1277 let loc = if let Some(first_line) = annotated_file.lines.first() {
1278 let col = if let Some(first_annotation) = first_line.annotations.first() {
1279 format!(":{}", first_annotation.start_col + 1)
1285 annotated_file.file.name,
1286 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1290 annotated_file.file.name.to_string()
1292 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1293 for _ in 0..max_line_num_len {
1294 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1298 if !self.short_message {
1299 // Put in the spacer between the location and annotated source
1300 let buffer_msg_line_offset = buffer.num_lines();
1301 draw_col_separator_no_space(
1303 buffer_msg_line_offset,
1304 max_line_num_len + 1,
1307 // Contains the vertical lines' positions for active multiline annotations
1308 let mut multilines = FxHashMap::default();
1310 // Get the left-side margin to remove it
1311 let mut whitespace_margin = std::usize::MAX;
1312 for line_idx in 0..annotated_file.lines.len() {
1313 let file = annotated_file.file.clone();
1314 let line = &annotated_file.lines[line_idx];
1315 if let Some(source_string) = file.get_line(line.line_index - 1) {
1316 let leading_whitespace =
1317 source_string.chars().take_while(|c| c.is_whitespace()).count();
1318 if source_string.chars().any(|c| !c.is_whitespace()) {
1319 whitespace_margin = min(whitespace_margin, leading_whitespace);
1323 if whitespace_margin == std::usize::MAX {
1324 whitespace_margin = 0;
1327 // Left-most column any visible span points at.
1328 let mut span_left_margin = std::usize::MAX;
1329 for line in &annotated_file.lines {
1330 for ann in &line.annotations {
1331 span_left_margin = min(span_left_margin, ann.start_col);
1332 span_left_margin = min(span_left_margin, ann.end_col);
1335 if span_left_margin == std::usize::MAX {
1336 span_left_margin = 0;
1339 // Right-most column any visible span points at.
1340 let mut span_right_margin = 0;
1341 let mut label_right_margin = 0;
1342 let mut max_line_len = 0;
1343 for line in &annotated_file.lines {
1346 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1348 for ann in &line.annotations {
1349 span_right_margin = max(span_right_margin, ann.start_col);
1350 span_right_margin = max(span_right_margin, ann.end_col);
1351 // FIXME: account for labels not in the same line
1352 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1353 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1357 let width_offset = 3 + max_line_num_len;
1358 let code_offset = if annotated_file.multiline_depth == 0 {
1361 width_offset + annotated_file.multiline_depth + 1
1364 let column_width = if let Some(width) = self.terminal_width {
1365 width.saturating_sub(code_offset)
1366 } else if self.ui_testing {
1369 term_size::dimensions()
1370 .map(|(w, _)| w.saturating_sub(code_offset))
1371 .unwrap_or(std::usize::MAX)
1374 let margin = Margin::new(
1383 // Next, output the annotate source for this file
1384 for line_idx in 0..annotated_file.lines.len() {
1385 let previous_buffer_line = buffer.num_lines();
1387 let depths = self.render_source_line(
1389 annotated_file.file.clone(),
1390 &annotated_file.lines[line_idx],
1396 let mut to_add = FxHashMap::default();
1398 for (depth, style) in depths {
1399 if multilines.get(&depth).is_some() {
1400 multilines.remove(&depth);
1402 to_add.insert(depth, style);
1406 // Set the multiline annotation vertical lines to the left of
1407 // the code in this line.
1408 for (depth, style) in &multilines {
1409 for line in previous_buffer_line..buffer.num_lines() {
1410 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1413 // check to see if we need to print out or elide lines that come between
1414 // this annotated line and the next one.
1415 if line_idx < (annotated_file.lines.len() - 1) {
1416 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1417 - annotated_file.lines[line_idx].line_index;
1418 if line_idx_delta > 2 {
1419 let last_buffer_line_num = buffer.num_lines();
1420 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1422 // Set the multiline annotation vertical lines on `...` bridging line.
1423 for (depth, style) in &multilines {
1424 draw_multiline_line(
1426 last_buffer_line_num,
1432 } else if line_idx_delta == 2 {
1433 let unannotated_line = annotated_file
1435 .get_line(annotated_file.lines[line_idx].line_index)
1436 .unwrap_or_else(|| Cow::from(""));
1438 let last_buffer_line_num = buffer.num_lines();
1443 annotated_file.lines[line_idx + 1].line_index - 1,
1444 last_buffer_line_num,
1450 for (depth, style) in &multilines {
1451 draw_multiline_line(
1453 last_buffer_line_num,
1462 multilines.extend(&to_add);
1467 // final step: take our styled buffer, render it, then output it
1468 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1473 fn emit_suggestion_default(
1475 suggestion: &CodeSuggestion,
1477 max_line_num_len: usize,
1478 ) -> io::Result<()> {
1479 let sm = match self.sm {
1481 None => return Ok(()),
1484 // Render the replacements for each suggestion
1485 let suggestions = suggestion.splice_lines(&**sm);
1487 if suggestions.is_empty() {
1488 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1489 // approach to avoid ICEs by ignoring the suggestion outright.
1493 let mut buffer = StyledBuffer::new();
1495 // Render the suggestion message
1496 let level_str = level.to_string();
1497 if !level_str.is_empty() {
1498 buffer.append(0, &level_str, Style::Level(level.clone()));
1499 buffer.append(0, ": ", Style::HeaderMsg);
1503 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1506 Some(Style::HeaderMsg),
1509 let mut row_num = 2;
1510 let mut notice_capitalization = false;
1511 for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
1512 notice_capitalization |= only_capitalization;
1513 // Only show underline if the suggestion spans a single line and doesn't cover the
1514 // entirety of the code output. If you have multiple replacements in the same line
1515 // of code, show the underline.
1516 let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
1517 && complete.lines().count() == 1;
1520 .span_to_lines(parts[0].span)
1521 .expect("span_to_lines failed when emitting suggestion");
1523 assert!(!lines.lines.is_empty());
1525 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1526 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1527 let mut line_pos = 0;
1528 let mut lines = complete.lines();
1529 for line in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES) {
1530 // Print the span column to avoid confusion
1534 &self.maybe_anonymized(line_start + line_pos),
1537 // print the suggestion
1538 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1539 buffer.append(row_num, line, Style::NoStyle);
1544 // This offset and the ones below need to be signed to account for replacement code
1545 // that is shorter than the original code.
1546 let mut offsets: Vec<(usize, isize)> = Vec::new();
1547 // Only show an underline in the suggestions if the suggestion is not the
1548 // entirety of the code being shown and the displayed code is not multiline.
1550 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1552 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1553 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1555 // Do not underline the leading...
1556 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1557 // ...or trailing spaces. Account for substitutions containing unicode
1559 let sub_len: usize = part
1563 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1566 let offset: isize = offsets
1569 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1572 let underline_start = (span_start_pos + start) as isize + offset;
1573 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1574 assert!(underline_start >= 0 && underline_end >= 0);
1575 for p in underline_start..underline_end {
1578 ((max_line_num_len + 3) as isize + p) as usize,
1580 Style::UnderlinePrimary,
1583 // underline removals too
1584 if underline_start == underline_end {
1585 for p in underline_start - 1..underline_start + 1 {
1588 ((max_line_num_len + 3) as isize + p) as usize,
1590 Style::UnderlineSecondary,
1595 // length of the code after substitution
1596 let full_sub_len = part
1599 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1600 .sum::<usize>() as isize;
1602 // length of the code to be substituted
1603 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1604 // For multiple substitutions, use the position *after* the previous
1605 // substitutions have happened, only when further substitutions are
1606 // located strictly after.
1607 offsets.push((span_end_pos, full_sub_len - snippet_len));
1612 // if we elided some lines, add an ellipsis
1613 if lines.next().is_some() {
1614 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1615 } else if !show_underline {
1616 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1620 if suggestions.len() > MAX_SUGGESTIONS {
1621 let others = suggestions.len() - MAX_SUGGESTIONS;
1622 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1623 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1624 } else if notice_capitalization {
1625 let msg = "notice the capitalization difference";
1626 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1628 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1632 fn emit_messages_default(
1635 message: &[(String, Style)],
1636 code: &Option<DiagnosticId>,
1638 children: &[SubDiagnostic],
1639 suggestions: &[CodeSuggestion],
1641 let max_line_num_len = if self.ui_testing {
1642 ANONYMIZED_LINE_NUM.len()
1644 self.get_max_line_num(span, children).to_string().len()
1647 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1649 if !children.is_empty()
1650 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1652 let mut buffer = StyledBuffer::new();
1653 if !self.short_message {
1654 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1656 match emit_to_destination(
1663 Err(e) => panic!("failed to emit error: {}", e),
1666 if !self.short_message {
1667 for child in children {
1668 let span = child.render_span.as_ref().unwrap_or(&child.span);
1669 match self.emit_message_default(
1671 &child.styled_message(),
1677 Err(e) => panic!("failed to emit error: {}", e),
1681 for sugg in suggestions {
1682 if sugg.style == SuggestionStyle::CompletelyHidden {
1683 // do not display this suggestion, it is meant only for tools
1684 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1685 match self.emit_message_default(
1687 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1693 Err(e) => panic!("failed to emit error: {}", e),
1697 match self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1699 Err(e) => panic!("failed to emit error: {}", e),
1706 Err(e) => panic!("failed to emit error: {}", e),
1709 let mut dst = self.dst.writable();
1710 match writeln!(dst) {
1711 Err(e) => panic!("failed to emit error: {}", e),
1712 _ => match dst.flush() {
1713 Err(e) => panic!("failed to emit error: {}", e),
1720 impl FileWithAnnotatedLines {
1721 /// Preprocess all the annotations so that they are grouped by file and by line number
1722 /// This helps us quickly iterate over the whole message (including secondary file spans)
1723 pub fn collect_annotations(
1725 source_map: &Option<Lrc<SourceMap>>,
1726 ) -> Vec<FileWithAnnotatedLines> {
1727 fn add_annotation_to_file(
1728 file_vec: &mut Vec<FileWithAnnotatedLines>,
1729 file: Lrc<SourceFile>,
1733 for slot in file_vec.iter_mut() {
1734 // Look through each of our files for the one we're adding to
1735 if slot.file.name == file.name {
1736 // See if we already have a line for it
1737 for line_slot in &mut slot.lines {
1738 if line_slot.line_index == line_index {
1739 line_slot.annotations.push(ann);
1743 // We don't have a line yet, create one
1744 slot.lines.push(Line { line_index, annotations: vec![ann] });
1749 // This is the first time we're seeing the file
1750 file_vec.push(FileWithAnnotatedLines {
1752 lines: vec![Line { line_index, annotations: vec![ann] }],
1757 let mut output = vec![];
1758 let mut multiline_annotations = vec![];
1760 if let Some(ref sm) = source_map {
1761 for span_label in msp.span_labels() {
1762 if span_label.span.is_dummy() {
1766 let lo = sm.lookup_char_pos(span_label.span.lo());
1767 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1769 // Watch out for "empty spans". If we get a span like 6..6, we
1770 // want to just display a `^` at 6, so convert that to
1771 // 6..7. This is degenerate input, but it's best to degrade
1772 // gracefully -- and the parser likes to supply a span like
1773 // that for EOF, in particular.
1775 if lo.col_display == hi.col_display && lo.line == hi.line {
1776 hi.col_display += 1;
1779 if lo.line != hi.line {
1780 let ml = MultilineAnnotation {
1782 line_start: lo.line,
1784 start_col: lo.col_display,
1785 end_col: hi.col_display,
1786 is_primary: span_label.is_primary,
1787 label: span_label.label,
1788 overlaps_exactly: false,
1790 multiline_annotations.push((lo.file, ml));
1792 let ann = Annotation {
1793 start_col: lo.col_display,
1794 end_col: hi.col_display,
1795 is_primary: span_label.is_primary,
1796 label: span_label.label,
1797 annotation_type: AnnotationType::Singleline,
1799 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1804 // Find overlapping multiline annotations, put them at different depths
1805 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1806 for (_, ann) in multiline_annotations.clone() {
1807 for (_, a) in multiline_annotations.iter_mut() {
1808 // Move all other multiline annotations overlapping with this one
1809 // one level to the right.
1810 if !(ann.same_span(a))
1811 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1814 } else if ann.same_span(a) && &ann != a {
1815 a.overlaps_exactly = true;
1822 let mut max_depth = 0; // max overlapping multiline spans
1823 for (file, ann) in multiline_annotations {
1824 max_depth = max(max_depth, ann.depth);
1825 let mut end_ann = ann.as_end();
1826 if !ann.overlaps_exactly {
1827 // avoid output like
1849 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1850 // 4 is the minimum vertical length of a multiline span when presented: two lines
1851 // of code and two lines of underline. This is not true for the special case where
1852 // the beginning doesn't have an underline, but the current logic seems to be
1853 // working correctly.
1854 let middle = min(ann.line_start + 4, ann.line_end);
1855 for line in ann.line_start + 1..middle {
1856 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1857 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1859 let line_end = ann.line_end - 1;
1860 if middle < line_end {
1861 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
1864 end_ann.annotation_type = AnnotationType::Singleline;
1866 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1868 for file_vec in output.iter_mut() {
1869 file_vec.multiline_depth = max_depth;
1875 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1876 buffer.puts(line, col, "| ", Style::LineNumber);
1879 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1880 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1883 fn draw_col_separator_no_space_with_style(
1884 buffer: &mut StyledBuffer,
1889 buffer.putc(line, col, '|', style);
1893 buffer: &mut StyledBuffer,
1900 for col in col_from..col_to {
1901 buffer.putc(line, col, symbol, style);
1905 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1906 buffer.puts(line, col, "= ", Style::LineNumber);
1909 fn draw_multiline_line(
1910 buffer: &mut StyledBuffer,
1916 buffer.putc(line, offset + depth - 1, '|', style);
1926 let extra = if inclusive { 1 } else { 0 };
1927 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
1929 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1930 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1933 fn emit_to_destination(
1934 rendered_buffer: &[Vec<StyledString>],
1936 dst: &mut Destination,
1937 short_message: bool,
1938 ) -> io::Result<()> {
1941 let mut dst = dst.writable();
1943 // In order to prevent error message interleaving, where multiple error lines get intermixed
1944 // when multiple compiler processes error simultaneously, we emit errors with additional
1947 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1948 // the .flush() is called we take the buffer created from the buffered writes and write it at
1949 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1950 // scheme, this buffered approach works and maintains the styling.
1952 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1953 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1954 // enough to output the full error message, then we release.
1955 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1956 for (pos, line) in rendered_buffer.iter().enumerate() {
1958 dst.apply_style(lvl.clone(), part.style)?;
1959 write!(dst, "{}", part.text)?;
1962 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
1970 pub enum Destination {
1971 Terminal(StandardStream),
1972 Buffered(BufferWriter),
1973 // The bool denotes whether we should be emitting ansi color codes or not
1974 Raw(Box<(dyn Write + Send)>, bool),
1977 pub enum WritableDst<'a> {
1978 Terminal(&'a mut StandardStream),
1979 Buffered(&'a mut BufferWriter, Buffer),
1980 Raw(&'a mut (dyn Write + Send)),
1981 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
1985 fn from_stderr(color: ColorConfig) -> Destination {
1986 let choice = color.to_color_choice();
1987 // On Windows we'll be performing global synchronization on the entire
1988 // system for emitting rustc errors, so there's no need to buffer
1991 // On non-Windows we rely on the atomicity of `write` to ensure errors
1992 // don't get all jumbled up.
1994 Terminal(StandardStream::stderr(choice))
1996 Buffered(BufferWriter::stderr(choice))
2000 fn writable(&mut self) -> WritableDst<'_> {
2002 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2003 Destination::Buffered(ref mut t) => {
2004 let buf = t.buffer();
2005 WritableDst::Buffered(t, buf)
2007 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2008 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2013 impl<'a> WritableDst<'a> {
2014 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2015 let mut spec = ColorSpec::new();
2017 Style::LineAndColumn => {}
2018 Style::LineNumber => {
2019 spec.set_bold(true);
2020 spec.set_intense(true);
2022 spec.set_fg(Some(Color::Cyan));
2024 spec.set_fg(Some(Color::Blue));
2027 Style::Quotation => {}
2028 Style::MainHeaderMsg => {
2029 spec.set_bold(true);
2031 spec.set_intense(true).set_fg(Some(Color::White));
2034 Style::UnderlinePrimary | Style::LabelPrimary => {
2036 spec.set_bold(true);
2038 Style::UnderlineSecondary | Style::LabelSecondary => {
2039 spec.set_bold(true).set_intense(true);
2041 spec.set_fg(Some(Color::Cyan));
2043 spec.set_fg(Some(Color::Blue));
2046 Style::HeaderMsg | Style::NoStyle => {}
2047 Style::Level(lvl) => {
2049 spec.set_bold(true);
2051 Style::Highlight => {
2052 spec.set_bold(true);
2055 self.set_color(&spec)
2058 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2060 WritableDst::Terminal(ref mut t) => t.set_color(color),
2061 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2062 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2063 WritableDst::Raw(_) => Ok(()),
2067 fn reset(&mut self) -> io::Result<()> {
2069 WritableDst::Terminal(ref mut t) => t.reset(),
2070 WritableDst::Buffered(_, ref mut t) => t.reset(),
2071 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2072 WritableDst::Raw(_) => Ok(()),
2077 impl<'a> Write for WritableDst<'a> {
2078 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2080 WritableDst::Terminal(ref mut t) => t.write(bytes),
2081 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2082 WritableDst::Raw(ref mut w) => w.write(bytes),
2083 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2087 fn flush(&mut self) -> io::Result<()> {
2089 WritableDst::Terminal(ref mut t) => t.flush(),
2090 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2091 WritableDst::Raw(ref mut w) => w.flush(),
2092 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2097 impl<'a> Drop for WritableDst<'a> {
2098 fn drop(&mut self) {
2100 WritableDst::Buffered(ref mut dst, ref mut buf) => {
2101 drop(dst.print(buf));
2108 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2109 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2110 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2111 let found = sm.span_to_snippet(sp).unwrap();
2112 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2113 // All the chars that differ in capitalization are confusable (above):
2114 let confusable = found
2116 .zip(suggested.chars())
2117 .filter(|(f, s)| f != s)
2118 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2119 confusable && found.to_lowercase() == suggested.to_lowercase()
2120 // FIXME: We sometimes suggest the same thing we already have, which is a
2121 // bug, but be defensive against that here.
2122 && found != suggested