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,
23 use rustc_data_structures::fx::FxHashMap;
24 use rustc_data_structures::sync::Lrc;
25 use rustc_span::hygiene::{ExpnKind, MacroKind};
27 use std::cmp::{max, min, Reverse};
29 use std::io::prelude::*;
31 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
32 use termcolor::{Buffer, Color, WriteColor};
34 /// Describes the way the content of the `rendered` field of the json output is generated
35 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
36 pub enum HumanReadableErrorType {
38 AnnotateSnippet(ColorConfig),
42 impl HumanReadableErrorType {
43 /// Returns a (`short`, `color`) tuple
44 pub fn unzip(self) -> (bool, ColorConfig) {
46 HumanReadableErrorType::Default(cc) => (false, cc),
47 HumanReadableErrorType::Short(cc) => (true, cc),
48 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
53 dst: Box<dyn Write + Send>,
54 source_map: Option<Lrc<SourceMap>>,
56 terminal_width: Option<usize>,
57 external_macro_backtrace: bool,
59 let (short, color_config) = self.unzip();
60 let color = color_config.suggests_using_colors();
68 external_macro_backtrace,
73 #[derive(Clone, Copy, Debug)]
75 /// The available whitespace in the left that can be consumed when centering.
76 pub whitespace_left: usize,
77 /// The column of the beginning of left-most span.
79 /// The column of the end of right-most span.
80 pub span_right: usize,
81 /// The beginning of the line to be displayed.
82 pub computed_left: usize,
83 /// The end of the line to be displayed.
84 pub computed_right: usize,
85 /// The current width of the terminal. 140 by default and in tests.
86 pub column_width: usize,
87 /// The end column of a span label, including the span. Doesn't account for labels not in the
88 /// same line as the span.
89 pub label_right: usize,
94 whitespace_left: usize,
101 // The 6 is padding to give a bit of room for `...` when displaying:
106 // 16 | ... fn foo(self) -> Self::Bar {
111 whitespace_left: whitespace_left.saturating_sub(6),
112 span_left: span_left.saturating_sub(6),
113 span_right: span_right + 6,
117 label_right: label_right + 6,
119 m.compute(max_line_len);
123 fn was_cut_left(&self) -> bool {
124 self.computed_left > 0
127 fn was_cut_right(&self, line_len: usize) -> bool {
129 if self.computed_right == self.span_right || self.computed_right == self.label_right {
130 // Account for the "..." padding given above. Otherwise we end up with code lines that
131 // do fit but end in "..." as if they were trimmed.
132 self.computed_right - 6
136 right < line_len && self.computed_left + self.column_width < line_len
139 fn compute(&mut self, max_line_len: usize) {
140 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
141 self.computed_left = if self.whitespace_left > 20 {
142 self.whitespace_left - 16 // We want some padding.
146 // We want to show as much as possible, max_line_len is the right-most boundary for the
148 self.computed_right = max(max_line_len, self.computed_left);
150 if self.computed_right - self.computed_left > self.column_width {
151 // Trimming only whitespace isn't enough, let's get craftier.
152 if self.label_right - self.whitespace_left <= self.column_width {
153 // Attempt to fit the code window only trimming whitespace.
154 self.computed_left = self.whitespace_left;
155 self.computed_right = self.computed_left + self.column_width;
156 } else if self.label_right - self.span_left <= self.column_width {
157 // Attempt to fit the code window considering only the spans and labels.
158 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
159 self.computed_left = self.span_left.saturating_sub(padding_left);
160 self.computed_right = self.computed_left + self.column_width;
161 } else if self.span_right - self.span_left <= self.column_width {
162 // Attempt to fit the code window considering the spans and labels plus padding.
163 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
164 self.computed_left = self.span_left.saturating_sub(padding_left);
165 self.computed_right = self.computed_left + self.column_width;
167 // Mostly give up but still don't show the full line.
168 self.computed_left = self.span_left;
169 self.computed_right = self.span_right;
174 fn left(&self, line_len: usize) -> usize {
175 min(self.computed_left, line_len)
178 fn right(&self, line_len: usize) -> usize {
179 if line_len.saturating_sub(self.computed_left) <= self.column_width {
182 min(line_len, self.computed_right)
187 const ANONYMIZED_LINE_NUM: &str = "LL";
189 /// Emitter trait for emitting errors.
191 /// Emit a structured diagnostic.
192 fn emit_diagnostic(&mut self, diag: &Diagnostic);
194 /// Emit a notification that an artifact has been output.
195 /// This is currently only supported for the JSON format,
196 /// other formats can, and will, simply ignore it.
197 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
199 /// Checks if should show explanations about "rustc --explain"
200 fn should_show_explain(&self) -> bool {
204 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
206 /// Formats the substitutions of the primary_span
208 /// The are a lot of conditions to this method, but in short:
210 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
211 /// we format the `help` suggestion depending on the content of the
212 /// substitutions. In that case, we return the modified span only.
214 /// * If the current `Diagnostic` has multiple suggestions,
215 /// we return the original `primary_span` and the original suggestions.
216 fn primary_span_formatted<'a>(
218 diag: &'a Diagnostic,
219 ) -> (MultiSpan, &'a [CodeSuggestion]) {
220 let mut primary_span = diag.span.clone();
221 if let Some((sugg, rest)) = diag.suggestions.split_first() {
222 if rest.is_empty() &&
223 // ^ if there is only one suggestion
224 // don't display multi-suggestions as labels
225 sugg.substitutions.len() == 1 &&
226 // don't display multipart suggestions as labels
227 sugg.substitutions[0].parts.len() == 1 &&
228 // don't display long messages as labels
229 sugg.msg.split_whitespace().count() < 10 &&
230 // don't display multiline suggestions as labels
231 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
233 // when this style is set we want the suggestion to be a message, not inline
234 SuggestionStyle::HideCodeAlways,
235 // trivial suggestion for tooling's sake, never shown
236 SuggestionStyle::CompletelyHidden,
237 // subtle suggestion, never shown inline
238 SuggestionStyle::ShowAlways,
239 ].contains(&sugg.style)
241 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
242 let msg = if substitution.len() == 0 || sugg.style.hide_inline() {
243 // This substitution is only removal OR we explicitly don't want to show the
244 // code inline (`hide_inline`). Therefore, we don't show the substitution.
245 format!("help: {}", sugg.msg)
247 // Show the default suggestion text with the substitution
253 .map(|sm| is_case_difference(
256 sugg.substitutions[0].parts[0].span,
260 " (notice the capitalization)"
267 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
269 // We return only the modified primary_span
272 // if there are multiple suggestions, print them all in full
273 // to be consistent. We could try to figure out if we can
274 // make one (or the first one) inline, but that would give
275 // undue importance to a semi-random suggestion
276 (primary_span, &diag.suggestions)
279 (primary_span, &diag.suggestions)
283 fn render_multispans_macro_backtrace_and_fix_extern_macros(
285 source_map: &Option<Lrc<SourceMap>>,
286 span: &mut MultiSpan,
287 children: &mut Vec<SubDiagnostic>,
291 self.render_multispans_macro_backtrace(source_map, span, children, backtrace);
294 if self.fix_multispans_in_extern_macros(source_map, span, children) {
295 let msg = if level == &Error {
296 "this error originates in a macro outside of the current crate \
297 (in Nightly builds, run with -Z external-macro-backtrace \
301 "this warning originates in a macro outside of the current crate \
302 (in Nightly builds, run with -Z external-macro-backtrace \
307 children.push(SubDiagnostic {
309 message: vec![(msg, Style::NoStyle)],
310 span: MultiSpan::new(),
317 fn render_multispans_macro_backtrace(
319 source_map: &Option<Lrc<SourceMap>>,
320 span: &mut MultiSpan,
321 children: &mut Vec<SubDiagnostic>,
324 self.render_multispan_macro_backtrace(source_map, span, backtrace);
325 for child in children.iter_mut() {
326 self.render_multispan_macro_backtrace(source_map, &mut child.span, backtrace);
330 fn render_multispan_macro_backtrace(
332 source_map: &Option<Lrc<SourceMap>>,
333 span: &mut MultiSpan,
334 always_backtrace: bool,
336 let sm = match source_map {
341 let mut new_labels: Vec<(Span, String)> = vec![];
343 // First, find all the spans in <*macros> and point instead at their use site
344 for &sp in span.primary_spans() {
348 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
349 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
350 // Only show macro locations that are local
351 // and display them like a span_note
352 if trace.def_site.is_dummy() {
355 if always_backtrace {
359 "in this expansion of `{}`{}",
361 if macro_backtrace.len() > 2 {
362 // if macro_backtrace.len() == 1 it'll be
363 // pointed at by "in this macro invocation"
364 format!(" (#{})", i + 1)
371 // Check to make sure we're not in any <*macros>
372 if !sm.span_to_filename(trace.def_site).is_macros()
373 && matches!(trace.kind, ExpnKind::Macro(MacroKind::Bang, _))
379 "in this macro invocation{}",
380 if macro_backtrace.len() > 2 && always_backtrace {
381 // only specify order when the macro
382 // backtrace is multiple levels deep
383 format!(" (#{})", i + 1)
389 if !always_backtrace {
395 for (label_span, label_text) in new_labels {
396 span.push_span_label(label_span, label_text);
400 // This does a small "fix" for multispans by looking to see if it can find any that
401 // point directly at <*macros>. Since these are often difficult to read, this
402 // will change the span to point at the use site.
403 fn fix_multispans_in_extern_macros(
405 source_map: &Option<Lrc<SourceMap>>,
406 span: &mut MultiSpan,
407 children: &mut Vec<SubDiagnostic>,
409 let mut spans_updated = self.fix_multispan_in_extern_macros(source_map, span);
410 for child in children.iter_mut() {
411 spans_updated |= self.fix_multispan_in_extern_macros(source_map, &mut child.span);
416 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
417 // <*macros>. Since these locations are often difficult to read, we move these Spans from
418 // <*macros> to their corresponding use site.
419 fn fix_multispan_in_extern_macros(
421 source_map: &Option<Lrc<SourceMap>>,
422 span: &mut MultiSpan,
424 let sm = match source_map {
426 None => return false,
429 // First, find all the spans in <*macros> and point instead at their use site
430 let replacements: Vec<(Span, Span)> = span
434 .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
436 if !sp.is_dummy() && sm.span_to_filename(sp).is_macros() {
437 let maybe_callsite = sp.source_callsite();
438 if sp != maybe_callsite {
439 return Some((sp, maybe_callsite));
446 // After we have them, make sure we replace these 'bad' def sites with their use sites
447 let spans_updated = !replacements.is_empty();
448 for (from, to) in replacements {
449 span.replace(from, to);
456 impl Emitter for EmitterWriter {
457 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
461 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
462 let mut children = diag.children.clone();
463 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
465 self.render_multispans_macro_backtrace_and_fix_extern_macros(
470 self.external_macro_backtrace,
473 self.emit_messages_default(
475 &diag.styled_message(),
483 fn should_show_explain(&self) -> bool {
488 /// An emitter that does nothing when emitting a diagnostic.
489 pub struct SilentEmitter;
491 impl Emitter for SilentEmitter {
492 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
495 fn emit_diagnostic(&mut self, _: &Diagnostic) {}
498 /// Maximum number of lines we will print for each error; arbitrary.
499 pub const MAX_HIGHLIGHT_LINES: usize = 6;
500 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
502 /// This should be replaced with a more involved mechanism to output multiline suggestions that
503 /// more closely mimmics the regular diagnostic output, where irrelevant code lines are elided.
504 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
505 /// Maximum number of suggestions to be shown
507 /// Arbitrary, but taken from trait import suggestion limit
508 pub const MAX_SUGGESTIONS: usize = 4;
510 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
511 pub enum ColorConfig {
518 fn to_color_choice(self) -> ColorChoice {
520 ColorConfig::Always => {
521 if atty::is(atty::Stream::Stderr) {
524 ColorChoice::AlwaysAnsi
527 ColorConfig::Never => ColorChoice::Never,
528 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
529 ColorConfig::Auto => ColorChoice::Never,
532 fn suggests_using_colors(self) -> bool {
534 ColorConfig::Always | ColorConfig::Auto => true,
535 ColorConfig::Never => false,
540 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
541 pub struct EmitterWriter {
543 sm: Option<Lrc<SourceMap>>,
547 terminal_width: Option<usize>,
549 external_macro_backtrace: bool,
553 pub struct FileWithAnnotatedLines {
554 pub file: Lrc<SourceFile>,
555 pub lines: Vec<Line>,
556 multiline_depth: usize,
561 color_config: ColorConfig,
562 source_map: Option<Lrc<SourceMap>>,
565 terminal_width: Option<usize>,
566 external_macro_backtrace: bool,
568 let dst = Destination::from_stderr(color_config);
576 external_macro_backtrace,
581 dst: Box<dyn Write + Send>,
582 source_map: Option<Lrc<SourceMap>>,
586 terminal_width: Option<usize>,
587 external_macro_backtrace: bool,
590 dst: Raw(dst, colored),
596 external_macro_backtrace,
600 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
601 self.ui_testing = ui_testing;
605 fn maybe_anonymized(&self, line_num: usize) -> String {
606 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
611 buffer: &mut StyledBuffer,
619 let line_len = source_string.len();
620 // Create the source line we will highlight.
621 let left = margin.left(line_len);
622 let right = margin.right(line_len);
623 // On long lines, we strip the source line, accounting for unicode.
625 let code: String = source_string
629 // Make sure that the trimming on the right will fall within the terminal width.
630 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
631 // For now, just accept that sometimes the code line will be longer than desired.
632 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
633 if taken + next > right - left {
640 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
641 if margin.was_cut_left() {
642 // We have stripped some code/whitespace from the beginning, make it clear.
643 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
645 if margin.was_cut_right(line_len) {
646 // We have stripped some code after the right-most span end, make it clear we did so.
647 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
649 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
651 draw_col_separator(buffer, line_offset, width_offset - 2);
654 fn render_source_line(
656 buffer: &mut StyledBuffer,
657 file: Lrc<SourceFile>,
662 ) -> Vec<(usize, Style)> {
668 // | secondary span label
670 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
672 // | | | actual code found in your source code and the spans we use to mark it
673 // | | when there's too much wasted space to the left, trim it
674 // | vertical divider between the column number and the code
677 if line.line_index == 0 {
681 let source_string = match file.get_line(line.line_index - 1) {
683 None => return Vec::new(),
686 let line_offset = buffer.num_lines();
688 let left = margin.left(source_string.len()); // Left trim
689 // Account for unicode characters of width !=0 that were removed.
690 let left = source_string
693 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
706 // Special case when there's only one annotation involved, it is the start of a multiline
707 // span and there's no text at the beginning of the code line. Instead of doing the whole
716 // we simplify the output to:
722 if let [ann] = &line.annotations[..] {
723 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
724 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
725 let style = if ann.is_primary {
726 Style::UnderlinePrimary
728 Style::UnderlineSecondary
730 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
731 return vec![(depth, style)];
736 // We want to display like this:
738 // vec.push(vec.pop().unwrap());
739 // --- ^^^ - previous borrow ends here
741 // | error occurs here
742 // previous borrow of `vec` occurs here
744 // But there are some weird edge cases to be aware of:
746 // vec.push(vec.pop().unwrap());
747 // -------- - previous borrow ends here
749 // |this makes no sense
750 // previous borrow of `vec` occurs here
752 // For this reason, we group the lines into "highlight lines"
753 // and "annotations lines", where the highlight lines have the `^`.
755 // Sort the annotations by (start, end col)
756 // The labels are reversed, sort and then reversed again.
757 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
758 // the letter signifies the span. Here we are only sorting by the
759 // span and hence, the order of the elements with the same span will
760 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
761 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
762 // still ordered first to last, but all the elements with different
763 // spans are ordered by their spans in last to first order. Last to
764 // first order is important, because the jiggly lines and | are on
765 // the left, so the rightmost span needs to be rendered first,
766 // otherwise the lines would end up needing to go over a message.
768 let mut annotations = line.annotations.clone();
769 annotations.sort_by_key(|a| Reverse(a.start_col));
771 // First, figure out where each label will be positioned.
773 // In the case where you have the following annotations:
775 // vec.push(vec.pop().unwrap());
776 // -------- - previous borrow ends here [C]
778 // |this makes no sense [B]
779 // previous borrow of `vec` occurs here [A]
781 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
783 // We try, when possible, to stick the rightmost annotation at the end
784 // of the highlight line:
786 // vec.push(vec.pop().unwrap());
787 // --- --- - previous borrow ends here
789 // But sometimes that's not possible because one of the other
790 // annotations overlaps it. For example, from the test
791 // `span_overlap_label`, we have the following annotations
792 // (written on distinct lines for clarity):
798 // In this case, we can't stick the rightmost-most label on
799 // the highlight line, or we would get:
806 // which is totally weird. Instead we want:
814 // which is...less weird, at least. In fact, in general, if
815 // the rightmost span overlaps with any other span, we should
816 // use the "hang below" version, so we can at least make it
817 // clear where the span *starts*. There's an exception for this
818 // logic, when the labels do not have a message:
833 let mut annotations_position = vec![];
834 let mut line_len = 0;
836 for (i, annotation) in annotations.iter().enumerate() {
837 for (j, next) in annotations.iter().enumerate() {
838 if overlaps(next, annotation, 0) // This label overlaps with another one and both
839 && annotation.has_label() // take space (they have text and are not
840 && j > i // multiline lines).
842 // We're currently on the first line, move the label one line down
844 // If we're overlapping with an un-labelled annotation with the same span
845 // we can just merge them in the output
846 if next.start_col == annotation.start_col
847 && next.end_col == annotation.end_col
853 // This annotation needs a new line in the output.
858 annotations_position.push((p, annotation));
859 for (j, next) in annotations.iter().enumerate() {
861 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
862 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
863 // line if they overlap including padding, to
864 // avoid situations like:
871 && annotation.has_label() // Both labels must have some text, otherwise
872 && next.has_label()) // they are not overlapping.
873 // Do not add a new line if this annotation
874 // or the next are vertical line placeholders.
875 || (annotation.takes_space() // If either this or the next annotation is
876 && next.has_label()) // multiline start/end, move it to a new line
877 || (annotation.has_label() // so as not to overlap the orizontal lines.
878 && next.takes_space())
879 || (annotation.takes_space() && next.takes_space())
880 || (overlaps(next, annotation, l)
881 && next.end_col <= annotation.end_col
886 // This annotation needs a new line in the output.
892 line_len = max(line_len, p);
899 // If there are no annotations or the only annotations on this line are
900 // MultilineLine, then there's only code being shown, stop processing.
901 if line.annotations.iter().all(|a| a.is_line()) {
905 // Write the column separator.
907 // After this we will have:
916 for pos in 0..=line_len {
917 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
918 buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber);
921 // Write the horizontal lines for multiline annotations
922 // (only the first and last lines need this).
924 // After this we will have:
933 for &(pos, annotation) in &annotations_position {
934 let style = if annotation.is_primary {
935 Style::UnderlinePrimary
937 Style::UnderlineSecondary
940 match annotation.annotation_type {
941 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
946 width_offset + depth,
947 code_offset + annotation.start_col - left,
952 buffer.set_style_range(
954 code_offset + annotation.start_col - left,
955 code_offset + annotation.end_col - left,
957 annotation.is_primary,
964 // Write the vertical lines for labels that are on a different line as the underline.
966 // After this we will have:
975 for &(pos, annotation) in &annotations_position {
976 let style = if annotation.is_primary {
977 Style::UnderlinePrimary
979 Style::UnderlineSecondary
983 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
984 for p in line_offset + 1..=line_offset + pos {
987 (code_offset + annotation.start_col).saturating_sub(left),
993 match annotation.annotation_type {
994 AnnotationType::MultilineStart(depth) => {
995 for p in line_offset + pos + 1..line_offset + line_len + 2 {
996 buffer.putc(p, width_offset + depth - 1, '|', style);
999 AnnotationType::MultilineEnd(depth) => {
1000 for p in line_offset..=line_offset + pos {
1001 buffer.putc(p, width_offset + depth - 1, '|', style);
1008 // Write the labels on the annotations that actually have a label.
1010 // After this we will have:
1015 // | something about `foo`
1019 for &(pos, annotation) in &annotations_position {
1021 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1022 let (pos, col) = if pos == 0 {
1023 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1025 (pos + 2, annotation.start_col.saturating_sub(left))
1027 if let Some(ref label) = annotation.label {
1028 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1032 // Sort from biggest span to smallest span so that smaller spans are
1033 // represented in the output:
1038 // | | something about `foo`
1039 // | something about `fn foo()`
1040 annotations_position.sort_by_key(|(_, ann)| {
1041 // Decreasing order. When annotations share the same length, prefer `Primary`.
1042 (Reverse(ann.len()), ann.is_primary)
1045 // Write the underlines.
1047 // After this we will have:
1052 // | something about `foo`
1056 for &(_, annotation) in &annotations_position {
1057 let (underline, style) = if annotation.is_primary {
1058 ('^', Style::UnderlinePrimary)
1060 ('-', Style::UnderlineSecondary)
1062 for p in annotation.start_col..annotation.end_col {
1065 (code_offset + p).saturating_sub(left),
1071 annotations_position
1073 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1074 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1075 let style = if annotation.is_primary {
1078 Style::LabelSecondary
1084 .collect::<Vec<_>>()
1087 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1088 let sm = match self.sm {
1094 for primary_span in msp.primary_spans() {
1095 if !primary_span.is_dummy() {
1096 let hi = sm.lookup_char_pos(primary_span.hi());
1097 max = (hi.line).max(max);
1100 if !self.short_message {
1101 for span_label in msp.span_labels() {
1102 if !span_label.span.is_dummy() {
1103 let hi = sm.lookup_char_pos(span_label.span.hi());
1104 max = (hi.line).max(max);
1112 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1113 let primary = self.get_multispan_max_line_num(span);
1116 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1122 /// Adds a left margin to every line but the first, given a padding length and the label being
1123 /// displayed, keeping the provided highlighting.
1126 buffer: &mut StyledBuffer,
1127 msg: &[(String, Style)],
1130 override_style: Option<Style>,
1132 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1135 // --> file.rs:13:20
1140 // = note: multiline
1145 // | | length of label
1147 // `max_line_num_len`
1148 let padding = " ".repeat(padding + label.len() + 5);
1150 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1151 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1152 match (style, override_) {
1153 (Style::NoStyle, Some(override_)) => override_,
1158 let mut line_number = 0;
1160 // Provided the following diagnostic message:
1164 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1165 // ("looks", Style::Highlight),
1166 // ("with\nvery ", Style::NoStyle),
1167 // ("weird", Style::Highlight),
1168 // (" formats\n", Style::NoStyle),
1169 // ("see?", Style::Highlight),
1172 // the expected output on a note is (* surround the highlighted text)
1174 // = note: highlighted multiline
1176 // see how it *looks* with
1177 // very *weird* formats
1179 for &(ref text, ref style) in msg.iter() {
1180 let lines = text.split('\n').collect::<Vec<_>>();
1181 if lines.len() > 1 {
1182 for (i, line) in lines.iter().enumerate() {
1185 buffer.append(line_number, &padding, Style::NoStyle);
1187 buffer.append(line_number, line, style_or_override(*style, override_style));
1190 buffer.append(line_number, text, style_or_override(*style, override_style));
1195 fn emit_message_default(
1198 msg: &[(String, Style)],
1199 code: &Option<DiagnosticId>,
1201 max_line_num_len: usize,
1203 ) -> io::Result<()> {
1204 let mut buffer = StyledBuffer::new();
1205 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1207 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1209 // This is a secondary message with no span info
1210 for _ in 0..max_line_num_len {
1211 buffer.prepend(0, " ", Style::NoStyle);
1213 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1214 if *level != Level::FailureNote {
1215 let level_str = level.to_string();
1216 if !level_str.is_empty() {
1217 buffer.append(0, &level_str, Style::MainHeaderMsg);
1218 buffer.append(0, ": ", Style::NoStyle);
1221 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1223 let level_str = level.to_string();
1224 // The failure note level itself does not provide any useful diagnostic information
1225 if *level != Level::FailureNote && !level_str.is_empty() {
1226 buffer.append(0, &level_str, Style::Level(*level));
1228 // only render error codes, not lint codes
1229 if let Some(DiagnosticId::Error(ref code)) = *code {
1230 buffer.append(0, "[", Style::Level(*level));
1231 buffer.append(0, &code, Style::Level(*level));
1232 buffer.append(0, "]", Style::Level(*level));
1234 if *level != Level::FailureNote && !level_str.is_empty() {
1235 buffer.append(0, ": ", header_style);
1237 for &(ref text, _) in msg.iter() {
1238 buffer.append(0, text, header_style);
1242 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1244 // Make sure our primary file comes first
1245 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1246 (self.sm.as_ref(), msp.primary_span().as_ref())
1248 if !primary_span.is_dummy() {
1249 (sm.lookup_char_pos(primary_span.lo()), sm)
1251 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1255 // If we don't have span information, emit and exit
1256 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1260 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1262 annotated_files.swap(0, pos);
1265 // Print out the annotate source lines that correspond with the error
1266 for annotated_file in annotated_files {
1267 // we can't annotate anything if the source is unavailable.
1268 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1272 // print out the span location and spacer before we print the annotated source
1273 // to do this, we need to know if this span will be primary
1274 let is_primary = primary_lo.file.name == annotated_file.file.name;
1276 let loc = primary_lo.clone();
1277 if !self.short_message {
1278 // remember where we are in the output buffer for easy reference
1279 let buffer_msg_line_offset = buffer.num_lines();
1281 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1283 buffer_msg_line_offset,
1287 sm.doctest_offset_line(&loc.file.name, loc.line),
1290 Style::LineAndColumn,
1292 for _ in 0..max_line_num_len {
1293 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1301 sm.doctest_offset_line(&loc.file.name, loc.line),
1304 Style::LineAndColumn,
1307 } else if !self.short_message {
1308 // remember where we are in the output buffer for easy reference
1309 let buffer_msg_line_offset = buffer.num_lines();
1312 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1314 // Then, the secondary file indicator
1315 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1316 let loc = if let Some(first_line) = annotated_file.lines.first() {
1317 let col = if let Some(first_annotation) = first_line.annotations.first() {
1318 format!(":{}", first_annotation.start_col + 1)
1324 annotated_file.file.name,
1325 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1329 annotated_file.file.name.to_string()
1331 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1332 for _ in 0..max_line_num_len {
1333 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1337 if !self.short_message {
1338 // Put in the spacer between the location and annotated source
1339 let buffer_msg_line_offset = buffer.num_lines();
1340 draw_col_separator_no_space(
1342 buffer_msg_line_offset,
1343 max_line_num_len + 1,
1346 // Contains the vertical lines' positions for active multiline annotations
1347 let mut multilines = FxHashMap::default();
1349 // Get the left-side margin to remove it
1350 let mut whitespace_margin = std::usize::MAX;
1351 for line_idx in 0..annotated_file.lines.len() {
1352 let file = annotated_file.file.clone();
1353 let line = &annotated_file.lines[line_idx];
1354 if let Some(source_string) = file.get_line(line.line_index - 1) {
1355 let leading_whitespace =
1356 source_string.chars().take_while(|c| c.is_whitespace()).count();
1357 if source_string.chars().any(|c| !c.is_whitespace()) {
1358 whitespace_margin = min(whitespace_margin, leading_whitespace);
1362 if whitespace_margin == std::usize::MAX {
1363 whitespace_margin = 0;
1366 // Left-most column any visible span points at.
1367 let mut span_left_margin = std::usize::MAX;
1368 for line in &annotated_file.lines {
1369 for ann in &line.annotations {
1370 span_left_margin = min(span_left_margin, ann.start_col);
1371 span_left_margin = min(span_left_margin, ann.end_col);
1374 if span_left_margin == std::usize::MAX {
1375 span_left_margin = 0;
1378 // Right-most column any visible span points at.
1379 let mut span_right_margin = 0;
1380 let mut label_right_margin = 0;
1381 let mut max_line_len = 0;
1382 for line in &annotated_file.lines {
1385 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1387 for ann in &line.annotations {
1388 span_right_margin = max(span_right_margin, ann.start_col);
1389 span_right_margin = max(span_right_margin, ann.end_col);
1390 // FIXME: account for labels not in the same line
1391 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1392 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1396 let width_offset = 3 + max_line_num_len;
1397 let code_offset = if annotated_file.multiline_depth == 0 {
1400 width_offset + annotated_file.multiline_depth + 1
1403 let column_width = if let Some(width) = self.terminal_width {
1404 width.saturating_sub(code_offset)
1405 } else if self.ui_testing {
1408 termize::dimensions()
1409 .map(|(w, _)| w.saturating_sub(code_offset))
1410 .unwrap_or(std::usize::MAX)
1413 let margin = Margin::new(
1422 // Next, output the annotate source for this file
1423 for line_idx in 0..annotated_file.lines.len() {
1424 let previous_buffer_line = buffer.num_lines();
1426 let depths = self.render_source_line(
1428 annotated_file.file.clone(),
1429 &annotated_file.lines[line_idx],
1435 let mut to_add = FxHashMap::default();
1437 for (depth, style) in depths {
1438 if multilines.get(&depth).is_some() {
1439 multilines.remove(&depth);
1441 to_add.insert(depth, style);
1445 // Set the multiline annotation vertical lines to the left of
1446 // the code in this line.
1447 for (depth, style) in &multilines {
1448 for line in previous_buffer_line..buffer.num_lines() {
1449 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1452 // check to see if we need to print out or elide lines that come between
1453 // this annotated line and the next one.
1454 if line_idx < (annotated_file.lines.len() - 1) {
1455 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1456 - annotated_file.lines[line_idx].line_index;
1457 if line_idx_delta > 2 {
1458 let last_buffer_line_num = buffer.num_lines();
1459 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1461 // Set the multiline annotation vertical lines on `...` bridging line.
1462 for (depth, style) in &multilines {
1463 draw_multiline_line(
1465 last_buffer_line_num,
1471 } else if line_idx_delta == 2 {
1472 let unannotated_line = annotated_file
1474 .get_line(annotated_file.lines[line_idx].line_index)
1475 .unwrap_or_else(|| Cow::from(""));
1477 let last_buffer_line_num = buffer.num_lines();
1482 annotated_file.lines[line_idx + 1].line_index - 1,
1483 last_buffer_line_num,
1489 for (depth, style) in &multilines {
1490 draw_multiline_line(
1492 last_buffer_line_num,
1501 multilines.extend(&to_add);
1506 // final step: take our styled buffer, render it, then output it
1507 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1512 fn emit_suggestion_default(
1514 suggestion: &CodeSuggestion,
1516 max_line_num_len: usize,
1517 ) -> io::Result<()> {
1518 let sm = match self.sm {
1520 None => return Ok(()),
1523 // Render the replacements for each suggestion
1524 let suggestions = suggestion.splice_lines(&**sm);
1526 if suggestions.is_empty() {
1527 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1528 // approach to avoid ICEs by ignoring the suggestion outright.
1532 let mut buffer = StyledBuffer::new();
1534 // Render the suggestion message
1535 let level_str = level.to_string();
1536 if !level_str.is_empty() {
1537 buffer.append(0, &level_str, Style::Level(*level));
1538 buffer.append(0, ": ", Style::HeaderMsg);
1542 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1545 Some(Style::HeaderMsg),
1548 let mut row_num = 2;
1549 let mut notice_capitalization = false;
1550 for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
1551 notice_capitalization |= only_capitalization;
1552 // Only show underline if the suggestion spans a single line and doesn't cover the
1553 // entirety of the code output. If you have multiple replacements in the same line
1554 // of code, show the underline.
1555 let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
1556 && complete.lines().count() == 1;
1559 .span_to_lines(parts[0].span)
1560 .expect("span_to_lines failed when emitting suggestion");
1562 assert!(!lines.lines.is_empty());
1564 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1565 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1566 let mut line_pos = 0;
1567 let mut lines = complete.lines();
1568 for line in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES) {
1569 // Print the span column to avoid confusion
1573 &self.maybe_anonymized(line_start + line_pos),
1576 // print the suggestion
1577 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1578 buffer.append(row_num, line, Style::NoStyle);
1583 // This offset and the ones below need to be signed to account for replacement code
1584 // that is shorter than the original code.
1585 let mut offsets: Vec<(usize, isize)> = Vec::new();
1586 // Only show an underline in the suggestions if the suggestion is not the
1587 // entirety of the code being shown and the displayed code is not multiline.
1589 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1591 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1592 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1594 // Do not underline the leading...
1595 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1596 // ...or trailing spaces. Account for substitutions containing unicode
1598 let sub_len: usize = part
1602 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1605 let offset: isize = offsets
1608 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1611 let underline_start = (span_start_pos + start) as isize + offset;
1612 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1613 assert!(underline_start >= 0 && underline_end >= 0);
1614 for p in underline_start..underline_end {
1617 ((max_line_num_len + 3) as isize + p) as usize,
1619 Style::UnderlinePrimary,
1622 // underline removals too
1623 if underline_start == underline_end {
1624 for p in underline_start - 1..underline_start + 1 {
1627 ((max_line_num_len + 3) as isize + p) as usize,
1629 Style::UnderlineSecondary,
1634 // length of the code after substitution
1635 let full_sub_len = part
1638 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1639 .sum::<usize>() as isize;
1641 // length of the code to be substituted
1642 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1643 // For multiple substitutions, use the position *after* the previous
1644 // substitutions have happened, only when further substitutions are
1645 // located strictly after.
1646 offsets.push((span_end_pos, full_sub_len - snippet_len));
1651 // if we elided some lines, add an ellipsis
1652 if lines.next().is_some() {
1653 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1654 } else if !show_underline {
1655 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1659 if suggestions.len() > MAX_SUGGESTIONS {
1660 let others = suggestions.len() - MAX_SUGGESTIONS;
1661 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1662 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1663 } else if notice_capitalization {
1664 let msg = "notice the capitalization difference";
1665 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1667 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1671 fn emit_messages_default(
1674 message: &[(String, Style)],
1675 code: &Option<DiagnosticId>,
1677 children: &[SubDiagnostic],
1678 suggestions: &[CodeSuggestion],
1680 let max_line_num_len = if self.ui_testing {
1681 ANONYMIZED_LINE_NUM.len()
1683 self.get_max_line_num(span, children).to_string().len()
1686 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1688 if !children.is_empty()
1689 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1691 let mut buffer = StyledBuffer::new();
1692 if !self.short_message {
1693 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1695 match emit_to_destination(
1702 Err(e) => panic!("failed to emit error: {}", e),
1705 if !self.short_message {
1706 for child in children {
1707 let span = child.render_span.as_ref().unwrap_or(&child.span);
1708 match self.emit_message_default(
1710 &child.styled_message(),
1716 Err(e) => panic!("failed to emit error: {}", e),
1720 for sugg in suggestions {
1721 if sugg.style == SuggestionStyle::CompletelyHidden {
1722 // do not display this suggestion, it is meant only for tools
1723 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1724 match self.emit_message_default(
1726 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1732 Err(e) => panic!("failed to emit error: {}", e),
1736 match self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1738 Err(e) => panic!("failed to emit error: {}", e),
1745 Err(e) => panic!("failed to emit error: {}", e),
1748 let mut dst = self.dst.writable();
1749 match writeln!(dst) {
1750 Err(e) => panic!("failed to emit error: {}", e),
1751 _ => match dst.flush() {
1752 Err(e) => panic!("failed to emit error: {}", e),
1759 impl FileWithAnnotatedLines {
1760 /// Preprocess all the annotations so that they are grouped by file and by line number
1761 /// This helps us quickly iterate over the whole message (including secondary file spans)
1762 pub fn collect_annotations(
1764 source_map: &Option<Lrc<SourceMap>>,
1765 ) -> Vec<FileWithAnnotatedLines> {
1766 fn add_annotation_to_file(
1767 file_vec: &mut Vec<FileWithAnnotatedLines>,
1768 file: Lrc<SourceFile>,
1772 for slot in file_vec.iter_mut() {
1773 // Look through each of our files for the one we're adding to
1774 if slot.file.name == file.name {
1775 // See if we already have a line for it
1776 for line_slot in &mut slot.lines {
1777 if line_slot.line_index == line_index {
1778 line_slot.annotations.push(ann);
1782 // We don't have a line yet, create one
1783 slot.lines.push(Line { line_index, annotations: vec![ann] });
1788 // This is the first time we're seeing the file
1789 file_vec.push(FileWithAnnotatedLines {
1791 lines: vec![Line { line_index, annotations: vec![ann] }],
1796 let mut output = vec![];
1797 let mut multiline_annotations = vec![];
1799 if let Some(ref sm) = source_map {
1800 for span_label in msp.span_labels() {
1801 if span_label.span.is_dummy() {
1805 let lo = sm.lookup_char_pos(span_label.span.lo());
1806 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1808 // Watch out for "empty spans". If we get a span like 6..6, we
1809 // want to just display a `^` at 6, so convert that to
1810 // 6..7. This is degenerate input, but it's best to degrade
1811 // gracefully -- and the parser likes to supply a span like
1812 // that for EOF, in particular.
1814 if lo.col_display == hi.col_display && lo.line == hi.line {
1815 hi.col_display += 1;
1818 if lo.line != hi.line {
1819 let ml = MultilineAnnotation {
1821 line_start: lo.line,
1823 start_col: lo.col_display,
1824 end_col: hi.col_display,
1825 is_primary: span_label.is_primary,
1826 label: span_label.label,
1827 overlaps_exactly: false,
1829 multiline_annotations.push((lo.file, ml));
1831 let ann = Annotation {
1832 start_col: lo.col_display,
1833 end_col: hi.col_display,
1834 is_primary: span_label.is_primary,
1835 label: span_label.label,
1836 annotation_type: AnnotationType::Singleline,
1838 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1843 // Find overlapping multiline annotations, put them at different depths
1844 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1845 for (_, ann) in multiline_annotations.clone() {
1846 for (_, a) in multiline_annotations.iter_mut() {
1847 // Move all other multiline annotations overlapping with this one
1848 // one level to the right.
1849 if !(ann.same_span(a))
1850 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1853 } else if ann.same_span(a) && &ann != a {
1854 a.overlaps_exactly = true;
1861 let mut max_depth = 0; // max overlapping multiline spans
1862 for (file, ann) in multiline_annotations {
1863 max_depth = max(max_depth, ann.depth);
1864 let mut end_ann = ann.as_end();
1865 if !ann.overlaps_exactly {
1866 // avoid output like
1888 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1889 // 4 is the minimum vertical length of a multiline span when presented: two lines
1890 // of code and two lines of underline. This is not true for the special case where
1891 // the beginning doesn't have an underline, but the current logic seems to be
1892 // working correctly.
1893 let middle = min(ann.line_start + 4, ann.line_end);
1894 for line in ann.line_start + 1..middle {
1895 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1896 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1898 let line_end = ann.line_end - 1;
1899 if middle < line_end {
1900 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
1903 end_ann.annotation_type = AnnotationType::Singleline;
1905 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1907 for file_vec in output.iter_mut() {
1908 file_vec.multiline_depth = max_depth;
1914 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1915 buffer.puts(line, col, "| ", Style::LineNumber);
1918 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1919 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1922 fn draw_col_separator_no_space_with_style(
1923 buffer: &mut StyledBuffer,
1928 buffer.putc(line, col, '|', style);
1932 buffer: &mut StyledBuffer,
1939 for col in col_from..col_to {
1940 buffer.putc(line, col, symbol, style);
1944 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1945 buffer.puts(line, col, "= ", Style::LineNumber);
1948 fn draw_multiline_line(
1949 buffer: &mut StyledBuffer,
1955 buffer.putc(line, offset + depth - 1, '|', style);
1965 let extra = if inclusive { 1 } else { 0 };
1966 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
1968 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1969 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1972 fn emit_to_destination(
1973 rendered_buffer: &[Vec<StyledString>],
1975 dst: &mut Destination,
1976 short_message: bool,
1977 ) -> io::Result<()> {
1980 let mut dst = dst.writable();
1982 // In order to prevent error message interleaving, where multiple error lines get intermixed
1983 // when multiple compiler processes error simultaneously, we emit errors with additional
1986 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1987 // the .flush() is called we take the buffer created from the buffered writes and write it at
1988 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1989 // scheme, this buffered approach works and maintains the styling.
1991 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1992 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1993 // enough to output the full error message, then we release.
1994 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1995 for (pos, line) in rendered_buffer.iter().enumerate() {
1997 dst.apply_style(lvl.clone(), part.style)?;
1998 write!(dst, "{}", part.text)?;
2001 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2009 pub enum Destination {
2010 Terminal(StandardStream),
2011 Buffered(BufferWriter),
2012 // The bool denotes whether we should be emitting ansi color codes or not
2013 Raw(Box<(dyn Write + Send)>, bool),
2016 pub enum WritableDst<'a> {
2017 Terminal(&'a mut StandardStream),
2018 Buffered(&'a mut BufferWriter, Buffer),
2019 Raw(&'a mut (dyn Write + Send)),
2020 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2024 fn from_stderr(color: ColorConfig) -> Destination {
2025 let choice = color.to_color_choice();
2026 // On Windows we'll be performing global synchronization on the entire
2027 // system for emitting rustc errors, so there's no need to buffer
2030 // On non-Windows we rely on the atomicity of `write` to ensure errors
2031 // don't get all jumbled up.
2033 Terminal(StandardStream::stderr(choice))
2035 Buffered(BufferWriter::stderr(choice))
2039 fn writable(&mut self) -> WritableDst<'_> {
2041 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2042 Destination::Buffered(ref mut t) => {
2043 let buf = t.buffer();
2044 WritableDst::Buffered(t, buf)
2046 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2047 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2052 impl<'a> WritableDst<'a> {
2053 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2054 let mut spec = ColorSpec::new();
2056 Style::LineAndColumn => {}
2057 Style::LineNumber => {
2058 spec.set_bold(true);
2059 spec.set_intense(true);
2061 spec.set_fg(Some(Color::Cyan));
2063 spec.set_fg(Some(Color::Blue));
2066 Style::Quotation => {}
2067 Style::MainHeaderMsg => {
2068 spec.set_bold(true);
2070 spec.set_intense(true).set_fg(Some(Color::White));
2073 Style::UnderlinePrimary | Style::LabelPrimary => {
2075 spec.set_bold(true);
2077 Style::UnderlineSecondary | Style::LabelSecondary => {
2078 spec.set_bold(true).set_intense(true);
2080 spec.set_fg(Some(Color::Cyan));
2082 spec.set_fg(Some(Color::Blue));
2085 Style::HeaderMsg | Style::NoStyle => {}
2086 Style::Level(lvl) => {
2088 spec.set_bold(true);
2090 Style::Highlight => {
2091 spec.set_bold(true);
2094 self.set_color(&spec)
2097 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2099 WritableDst::Terminal(ref mut t) => t.set_color(color),
2100 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2101 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2102 WritableDst::Raw(_) => Ok(()),
2106 fn reset(&mut self) -> io::Result<()> {
2108 WritableDst::Terminal(ref mut t) => t.reset(),
2109 WritableDst::Buffered(_, ref mut t) => t.reset(),
2110 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2111 WritableDst::Raw(_) => Ok(()),
2116 impl<'a> Write for WritableDst<'a> {
2117 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2119 WritableDst::Terminal(ref mut t) => t.write(bytes),
2120 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2121 WritableDst::Raw(ref mut w) => w.write(bytes),
2122 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2126 fn flush(&mut self) -> io::Result<()> {
2128 WritableDst::Terminal(ref mut t) => t.flush(),
2129 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2130 WritableDst::Raw(ref mut w) => w.flush(),
2131 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2136 impl<'a> Drop for WritableDst<'a> {
2137 fn drop(&mut self) {
2139 WritableDst::Buffered(ref mut dst, ref mut buf) => {
2140 drop(dst.print(buf));
2147 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2148 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2149 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2150 let found = match sm.span_to_snippet(sp) {
2151 Ok(snippet) => snippet,
2153 warn!("Invalid span {:?}. Err={:?}", sp, e);
2157 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2158 // All the chars that differ in capitalization are confusable (above):
2159 let confusable = found
2161 .zip(suggested.chars())
2162 .filter(|(f, s)| f != s)
2163 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2164 confusable && found.to_lowercase() == suggested.to_lowercase()
2165 // FIXME: We sometimes suggest the same thing we already have, which is a
2166 // bug, but be defensive against that here.
2167 && found != suggested