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 syntax_pos::{SourceFile, Span, MultiSpan};
15 Level, CodeSuggestion, Diagnostic, SubDiagnostic,
16 SuggestionStyle, SourceMapperDyn, DiagnosticId,
18 use crate::Level::Error;
19 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
20 use crate::styled_buffer::StyledBuffer;
22 use rustc_data_structures::fx::FxHashMap;
23 use rustc_data_structures::sync::Lrc;
25 use std::io::prelude::*;
27 use std::cmp::{min, max, Reverse};
29 use termcolor::{StandardStream, ColorChoice, ColorSpec, BufferWriter, Ansi};
30 use termcolor::{WriteColor, Color, Buffer};
32 /// Describes the way the content of the `rendered` field of the json output is generated
33 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
34 pub enum HumanReadableErrorType {
36 AnnotateSnippet(ColorConfig),
40 impl HumanReadableErrorType {
41 /// Returns a (`short`, `color`) tuple
42 pub fn unzip(self) -> (bool, ColorConfig) {
44 HumanReadableErrorType::Default(cc) => (false, cc),
45 HumanReadableErrorType::Short(cc) => (true, cc),
46 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
51 dst: Box<dyn Write + Send>,
52 source_map: Option<Lrc<SourceMapperDyn>>,
54 terminal_width: Option<usize>,
55 external_macro_backtrace: bool,
57 let (short, color_config) = self.unzip();
58 let color = color_config.suggests_using_colors();
59 EmitterWriter::new(dst, source_map, short, teach, color, terminal_width,
60 external_macro_backtrace)
64 #[derive(Clone, Copy, Debug)]
66 /// The available whitespace in the left that can be consumed when centering.
67 pub whitespace_left: usize,
68 /// The column of the beginning of left-most span.
70 /// The column of the end of right-most span.
71 pub span_right: usize,
72 /// The beginning of the line to be displayed.
73 pub computed_left: usize,
74 /// The end of the line to be displayed.
75 pub computed_right: usize,
76 /// The current width of the terminal. 140 by default and in tests.
77 pub column_width: usize,
78 /// The end column of a span label, including the span. Doesn't account for labels not in the
79 /// same line as the span.
80 pub label_right: usize,
85 whitespace_left: usize,
92 // The 6 is padding to give a bit of room for `...` when displaying:
97 // 16 | ... fn foo(self) -> Self::Bar {
102 whitespace_left: whitespace_left.saturating_sub(6),
103 span_left: span_left.saturating_sub(6),
104 span_right: span_right + 6,
108 label_right: label_right + 6,
110 m.compute(max_line_len);
114 fn was_cut_left(&self) -> bool {
115 self.computed_left > 0
118 fn was_cut_right(&self, line_len: usize) -> bool {
119 let right = if self.computed_right == self.span_right ||
120 self.computed_right == self.label_right
122 // Account for the "..." padding given above. Otherwise we end up with code lines that
123 // do fit but end in "..." as if they were trimmed.
124 self.computed_right - 6
128 right < line_len && line_len > self.computed_left + self.column_width
131 fn compute(&mut self, max_line_len: usize) {
132 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
133 self.computed_left = if self.whitespace_left > 20 {
134 self.whitespace_left - 16 // We want some padding.
138 // We want to show as much as possible, max_line_len is the right-most boundary for the
140 self.computed_right = max(max_line_len, self.computed_left);
142 if self.computed_right - self.computed_left > self.column_width {
143 // Trimming only whitespace isn't enough, let's get craftier.
144 if self.label_right - self.whitespace_left <= self.column_width {
145 // Attempt to fit the code window only trimming whitespace.
146 self.computed_left = self.whitespace_left;
147 self.computed_right = self.computed_left + self.column_width;
148 } else if self.label_right - self.span_left <= self.column_width {
149 // Attempt to fit the code window considering only the spans and labels.
150 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
151 self.computed_left = self.span_left.saturating_sub(padding_left);
152 self.computed_right = self.computed_left + self.column_width;
153 } else if self.span_right - self.span_left <= self.column_width {
154 // Attempt to fit the code window considering the spans and labels plus padding.
155 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
156 self.computed_left = self.span_left.saturating_sub(padding_left);
157 self.computed_right = self.computed_left + self.column_width;
158 } else { // Mostly give up but still don't show the full line.
159 self.computed_left = self.span_left;
160 self.computed_right = self.span_right;
165 fn left(&self, line_len: usize) -> usize {
166 min(self.computed_left, line_len)
169 fn right(&self, line_len: usize) -> usize {
170 if line_len.saturating_sub(self.computed_left) <= self.column_width {
172 } else if self.computed_right > line_len {
180 const ANONYMIZED_LINE_NUM: &str = "LL";
182 /// Emitter trait for emitting errors.
184 /// Emit a structured diagnostic.
185 fn emit_diagnostic(&mut self, db: &Diagnostic);
187 /// Emit a notification that an artifact has been output.
188 /// This is currently only supported for the JSON format,
189 /// other formats can, and will, simply ignore it.
190 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
192 /// Checks if should show explanations about "rustc --explain"
193 fn should_show_explain(&self) -> bool {
197 /// Formats the substitutions of the primary_span
199 /// The are a lot of conditions to this method, but in short:
201 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
202 /// we format the `help` suggestion depending on the content of the
203 /// substitutions. In that case, we return the modified span only.
205 /// * If the current `Diagnostic` has multiple suggestions,
206 /// we return the original `primary_span` and the original suggestions.
207 fn primary_span_formatted<'a>(
210 ) -> (MultiSpan, &'a [CodeSuggestion]) {
211 let mut primary_span = db.span.clone();
212 if let Some((sugg, rest)) = db.suggestions.split_first() {
213 if rest.is_empty() &&
214 // ^ if there is only one suggestion
215 // don't display multi-suggestions as labels
216 sugg.substitutions.len() == 1 &&
217 // don't display multipart suggestions as labels
218 sugg.substitutions[0].parts.len() == 1 &&
219 // don't display long messages as labels
220 sugg.msg.split_whitespace().count() < 10 &&
221 // don't display multiline suggestions as labels
222 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
223 // when this style is set we want the suggestion to be a message, not inline
224 sugg.style != SuggestionStyle::HideCodeAlways &&
225 // trivial suggestion for tooling's sake, never shown
226 sugg.style != SuggestionStyle::CompletelyHidden
228 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
229 let msg = if substitution.len() == 0 || sugg.style.hide_inline() {
230 // This substitution is only removal OR we explicitly don't want to show the
231 // code inline (`hide_inline`). Therefore, we don't show the substitution.
232 format!("help: {}", sugg.msg)
234 // Show the default suggestion text with the substitution
235 format!("help: {}: `{}`", sugg.msg, substitution)
237 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
239 // We return only the modified primary_span
242 // if there are multiple suggestions, print them all in full
243 // to be consistent. We could try to figure out if we can
244 // make one (or the first one) inline, but that would give
245 // undue importance to a semi-random suggestion
246 (primary_span, &db.suggestions)
249 (primary_span, &db.suggestions)
253 // This does a small "fix" for multispans by looking to see if it can find any that
254 // point directly at <*macros>. Since these are often difficult to read, this
255 // will change the span to point at the use site.
256 fn fix_multispans_in_std_macros(&self,
257 source_map: &Option<Lrc<SourceMapperDyn>>,
258 span: &mut MultiSpan,
259 children: &mut Vec<SubDiagnostic>,
262 let mut spans_updated = self.fix_multispan_in_std_macros(source_map, span, backtrace);
263 for child in children.iter_mut() {
264 spans_updated |= self.fix_multispan_in_std_macros(
270 let msg = if level == &Error {
271 "this error originates in a macro outside of the current crate \
272 (in Nightly builds, run with -Z external-macro-backtrace \
273 for more info)".to_string()
275 "this warning originates in a macro outside of the current crate \
276 (in Nightly builds, run with -Z external-macro-backtrace \
277 for more info)".to_string()
281 children.push(SubDiagnostic {
287 span: MultiSpan::new(),
293 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
294 // <*macros>. Since these locations are often difficult to read, we move these Spans from
295 // <*macros> to their corresponding use site.
296 fn fix_multispan_in_std_macros(&self,
297 source_map: &Option<Lrc<SourceMapperDyn>>,
298 span: &mut MultiSpan,
299 always_backtrace: bool) -> bool {
300 let mut spans_updated = false;
302 if let Some(ref sm) = source_map {
303 let mut before_after: Vec<(Span, Span)> = vec![];
304 let mut new_labels: Vec<(Span, String)> = vec![];
306 // First, find all the spans in <*macros> and point instead at their use site
307 for sp in span.primary_spans() {
311 let call_sp = sm.call_span_if_macro(*sp);
312 if call_sp != *sp && !always_backtrace {
313 before_after.push((*sp, call_sp));
315 let backtrace_len = sp.macro_backtrace().len();
316 for (i, trace) in sp.macro_backtrace().iter().rev().enumerate() {
317 // Only show macro locations that are local
318 // and display them like a span_note
319 if trace.def_site_span.is_dummy() {
322 if always_backtrace {
323 new_labels.push((trace.def_site_span,
324 format!("in this expansion of `{}`{}",
325 trace.macro_decl_name,
326 if backtrace_len > 2 {
327 // if backtrace_len == 1 it'll be pointed
328 // at by "in this macro invocation"
329 format!(" (#{})", i + 1)
334 // Check to make sure we're not in any <*macros>
335 if !sm.span_to_filename(trace.def_site_span).is_macros() &&
336 !trace.macro_decl_name.starts_with("desugaring of ") &&
337 !trace.macro_decl_name.starts_with("#[") ||
339 new_labels.push((trace.call_site,
340 format!("in this macro invocation{}",
341 if backtrace_len > 2 && always_backtrace {
342 // only specify order when the macro
343 // backtrace is multiple levels deep
344 format!(" (#{})", i + 1)
348 if !always_backtrace {
354 for (label_span, label_text) in new_labels {
355 span.push_span_label(label_span, label_text);
357 for sp_label in span.span_labels() {
358 if sp_label.span.is_dummy() {
361 if sm.span_to_filename(sp_label.span.clone()).is_macros() &&
364 let v = sp_label.span.macro_backtrace();
365 if let Some(use_site) = v.last() {
366 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
370 // After we have them, make sure we replace these 'bad' def sites with their use sites
371 for (before, after) in before_after {
372 span.replace(before, after);
373 spans_updated = true;
381 impl Emitter for EmitterWriter {
382 fn emit_diagnostic(&mut self, db: &Diagnostic) {
383 let mut children = db.children.clone();
384 let (mut primary_span, suggestions) = self.primary_span_formatted(&db);
386 self.fix_multispans_in_std_macros(&self.sm,
390 self.external_macro_backtrace);
392 self.emit_messages_default(&db.level,
393 &db.styled_message(),
400 fn should_show_explain(&self) -> bool {
405 /// maximum number of lines we will print for each error; arbitrary.
406 pub const MAX_HIGHLIGHT_LINES: usize = 6;
407 /// maximum number of suggestions to be shown
409 /// Arbitrary, but taken from trait import suggestion limit
410 pub const MAX_SUGGESTIONS: usize = 4;
412 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
413 pub enum ColorConfig {
420 fn to_color_choice(self) -> ColorChoice {
422 ColorConfig::Always => {
423 if atty::is(atty::Stream::Stderr) {
426 ColorChoice::AlwaysAnsi
429 ColorConfig::Never => ColorChoice::Never,
430 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => {
433 ColorConfig::Auto => ColorChoice::Never,
436 fn suggests_using_colors(self) -> bool {
438 | ColorConfig::Always
441 ColorConfig::Never => false,
446 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
447 pub struct EmitterWriter {
449 sm: Option<Lrc<SourceMapperDyn>>,
453 terminal_width: Option<usize>,
455 external_macro_backtrace: bool,
459 pub struct FileWithAnnotatedLines {
460 pub file: Lrc<SourceFile>,
461 pub lines: Vec<Line>,
462 multiline_depth: usize,
467 color_config: ColorConfig,
468 source_map: Option<Lrc<SourceMapperDyn>>,
471 terminal_width: Option<usize>,
472 external_macro_backtrace: bool,
474 let dst = Destination::from_stderr(color_config);
482 external_macro_backtrace,
487 dst: Box<dyn Write + Send>,
488 source_map: Option<Lrc<SourceMapperDyn>>,
492 terminal_width: Option<usize>,
493 external_macro_backtrace: bool,
496 dst: Raw(dst, colored),
502 external_macro_backtrace,
506 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
507 self.ui_testing = ui_testing;
511 fn maybe_anonymized(&self, line_num: usize) -> String {
513 ANONYMIZED_LINE_NUM.to_string()
521 buffer: &mut StyledBuffer,
529 let line_len = source_string.len();
530 // Create the source line we will highlight.
531 let left = margin.left(line_len);
532 let right = margin.right(line_len);
533 // On long lines, we strip the source line, accounting for unicode.
535 let code: String = source_string.chars().skip(left).take_while(|ch| {
536 // Make sure that the trimming on the right will fall within the terminal width.
537 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
538 // For now, just accept that sometimes the code line will be longer than desired.
539 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
540 if taken + next > right - left {
546 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
547 if margin.was_cut_left() {
548 // We have stripped some code/whitespace from the beginning, make it clear.
549 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
551 if margin.was_cut_right(line_len) {
552 // We have stripped some code after the right-most span end, make it clear we did so.
553 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
555 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
557 draw_col_separator(buffer, line_offset, width_offset - 2);
560 fn render_source_line(
562 buffer: &mut StyledBuffer,
563 file: Lrc<SourceFile>,
568 ) -> Vec<(usize, Style)> {
574 // | secondary span label
576 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
578 // | | | actual code found in your source code and the spans we use to mark it
579 // | | when there's too much wasted space to the left, trim it
580 // | vertical divider between the column number and the code
583 if line.line_index == 0 {
587 let source_string = match file.get_line(line.line_index - 1) {
589 None => return Vec::new(),
592 let line_offset = buffer.num_lines();
594 let left = margin.left(source_string.len()); // Left trim
595 // Account for unicode characters of width !=0 that were removed.
596 let left = source_string.chars().take(left).fold(0, |acc, ch| {
597 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1)
610 // Special case when there's only one annotation involved, it is the start of a multiline
611 // span and there's no text at the beginning of the code line. Instead of doing the whole
620 // we simplify the output to:
626 if line.annotations.len() == 1 {
627 if let Some(ref ann) = line.annotations.get(0) {
628 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
629 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
630 let style = if ann.is_primary {
631 Style::UnderlinePrimary
633 Style::UnderlineSecondary
635 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
636 return vec![(depth, style)];
642 // We want to display like this:
644 // vec.push(vec.pop().unwrap());
645 // --- ^^^ - previous borrow ends here
647 // | error occurs here
648 // previous borrow of `vec` occurs here
650 // But there are some weird edge cases to be aware of:
652 // vec.push(vec.pop().unwrap());
653 // -------- - previous borrow ends here
655 // |this makes no sense
656 // previous borrow of `vec` occurs here
658 // For this reason, we group the lines into "highlight lines"
659 // and "annotations lines", where the highlight lines have the `^`.
661 // Sort the annotations by (start, end col)
662 // The labels are reversed, sort and then reversed again.
663 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
664 // the letter signifies the span. Here we are only sorting by the
665 // span and hence, the order of the elements with the same span will
666 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
667 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
668 // still ordered first to last, but all the elements with different
669 // spans are ordered by their spans in last to first order. Last to
670 // first order is important, because the jiggly lines and | are on
671 // the left, so the rightmost span needs to be rendered first,
672 // otherwise the lines would end up needing to go over a message.
674 let mut annotations = line.annotations.clone();
675 annotations.sort_by_key(|a| Reverse(a.start_col));
677 // First, figure out where each label will be positioned.
679 // In the case where you have the following annotations:
681 // vec.push(vec.pop().unwrap());
682 // -------- - previous borrow ends here [C]
684 // |this makes no sense [B]
685 // previous borrow of `vec` occurs here [A]
687 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
689 // We try, when possible, to stick the rightmost annotation at the end
690 // of the highlight line:
692 // vec.push(vec.pop().unwrap());
693 // --- --- - previous borrow ends here
695 // But sometimes that's not possible because one of the other
696 // annotations overlaps it. For example, from the test
697 // `span_overlap_label`, we have the following annotations
698 // (written on distinct lines for clarity):
704 // In this case, we can't stick the rightmost-most label on
705 // the highlight line, or we would get:
712 // which is totally weird. Instead we want:
720 // which is...less weird, at least. In fact, in general, if
721 // the rightmost span overlaps with any other span, we should
722 // use the "hang below" version, so we can at least make it
723 // clear where the span *starts*. There's an exception for this
724 // logic, when the labels do not have a message:
739 let mut annotations_position = vec![];
740 let mut line_len = 0;
742 for (i, annotation) in annotations.iter().enumerate() {
743 for (j, next) in annotations.iter().enumerate() {
744 if overlaps(next, annotation, 0) // This label overlaps with another one and both
745 && annotation.has_label() // take space (they have text and are not
746 && j > i // multiline lines).
747 && p == 0 // We're currently on the first line, move the label one line down
749 // If we're overlapping with an un-labelled annotation with the same span
750 // we can just merge them in the output
751 if next.start_col == annotation.start_col
752 && next.end_col == annotation.end_col
758 // This annotation needs a new line in the output.
763 annotations_position.push((p, annotation));
764 for (j, next) in annotations.iter().enumerate() {
766 let l = if let Some(ref label) = next.label {
771 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
772 // line if they overlap including padding, to
773 // avoid situations like:
780 && annotation.has_label() // Both labels must have some text, otherwise
781 && next.has_label()) // they are not overlapping.
782 // Do not add a new line if this annotation
783 // or the next are vertical line placeholders.
784 || (annotation.takes_space() // If either this or the next annotation is
785 && next.has_label()) // multiline start/end, move it to a new line
786 || (annotation.has_label() // so as not to overlap the orizontal lines.
787 && next.takes_space())
788 || (annotation.takes_space() && next.takes_space())
789 || (overlaps(next, annotation, l)
790 && next.end_col <= annotation.end_col
792 && p == 0) // Avoid #42595.
794 // This annotation needs a new line in the output.
809 // If there are no annotations or the only annotations on this line are
810 // MultilineLine, then there's only code being shown, stop processing.
811 if line.annotations.iter().all(|a| a.is_line()) {
815 // Write the colunmn separator.
817 // After this we will have:
826 for pos in 0..=line_len {
827 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
828 buffer.putc(line_offset + pos + 1,
834 // Write the horizontal lines for multiline annotations
835 // (only the first and last lines need this).
837 // After this we will have:
846 for &(pos, annotation) in &annotations_position {
847 let style = if annotation.is_primary {
848 Style::UnderlinePrimary
850 Style::UnderlineSecondary
853 match annotation.annotation_type {
854 AnnotationType::MultilineStart(depth) |
855 AnnotationType::MultilineEnd(depth) => {
860 width_offset + depth,
861 code_offset + annotation.start_col - left,
866 buffer.set_style_range(
868 code_offset + annotation.start_col - left,
869 code_offset + annotation.end_col - left,
871 annotation.is_primary,
878 // Write the vertical lines for labels that are on a different line as the underline.
880 // After this we will have:
889 for &(pos, annotation) in &annotations_position {
890 let style = if annotation.is_primary {
891 Style::UnderlinePrimary
893 Style::UnderlineSecondary
897 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
898 for p in line_offset + 1..=line_offset + pos {
900 code_offset + annotation.start_col - margin.computed_left,
905 match annotation.annotation_type {
906 AnnotationType::MultilineStart(depth) => {
907 for p in line_offset + pos + 1..line_offset + line_len + 2 {
909 width_offset + depth - 1,
914 AnnotationType::MultilineEnd(depth) => {
915 for p in line_offset..=line_offset + pos {
917 width_offset + depth - 1,
926 // Write the labels on the annotations that actually have a label.
928 // After this we will have:
933 // | something about `foo`
937 for &(pos, annotation) in &annotations_position {
938 let style = if annotation.is_primary {
941 Style::LabelSecondary
943 let (pos, col) = if pos == 0 {
944 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
946 (pos + 2, annotation.start_col.saturating_sub(left))
948 if let Some(ref label) = annotation.label {
949 buffer.puts(line_offset + pos, code_offset + col, &label, style);
953 // Sort from biggest span to smallest span so that smaller spans are
954 // represented in the output:
959 // | | something about `foo`
960 // | something about `fn foo()`
961 annotations_position.sort_by(|a, b| {
962 // Decreasing order. When `a` and `b` are the same length, prefer `Primary`.
963 (a.1.len(), !a.1.is_primary).cmp(&(b.1.len(), !b.1.is_primary)).reverse()
966 // Write the underlines.
968 // After this we will have:
973 // | something about `foo`
977 for &(_, annotation) in &annotations_position {
978 let (underline, style) = if annotation.is_primary {
979 ('^', Style::UnderlinePrimary)
981 ('-', Style::UnderlineSecondary)
983 for p in annotation.start_col..annotation.end_col {
986 (code_offset + p).saturating_sub(left),
992 annotations_position.iter().filter_map(|&(_, annotation)| {
993 match annotation.annotation_type {
994 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
995 let style = if annotation.is_primary {
998 Style::LabelSecondary
1005 }).collect::<Vec<_>>()
1008 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1010 if let Some(ref sm) = self.sm {
1011 for primary_span in msp.primary_spans() {
1012 if !primary_span.is_dummy() {
1013 let hi = sm.lookup_char_pos(primary_span.hi());
1019 if !self.short_message {
1020 for span_label in msp.span_labels() {
1021 if !span_label.span.is_dummy() {
1022 let hi = sm.lookup_char_pos(span_label.span.hi());
1033 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1035 let primary = self.get_multispan_max_line_num(span);
1036 let mut max = primary;
1038 for sub in children {
1039 let sub_result = self.get_multispan_max_line_num(&sub.span);
1040 max = std::cmp::max(sub_result, max);
1045 /// Adds a left margin to every line but the first, given a padding length and the label being
1046 /// displayed, keeping the provided highlighting.
1047 fn msg_to_buffer(&self,
1048 buffer: &mut StyledBuffer,
1049 msg: &[(String, Style)],
1052 override_style: Option<Style>) {
1054 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1057 // --> file.rs:13:20
1062 // = note: multiline
1067 // | | length of label
1069 // `max_line_num_len`
1070 let padding = " ".repeat(padding + label.len() + 5);
1072 /// Returns `true` if `style`, or the override if present and the style is `NoStyle`.
1073 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
1074 if let Some(o) = override_style {
1075 if style == Style::NoStyle {
1082 let mut line_number = 0;
1084 // Provided the following diagnostic message:
1088 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1089 // ("looks", Style::Highlight),
1090 // ("with\nvery ", Style::NoStyle),
1091 // ("weird", Style::Highlight),
1092 // (" formats\n", Style::NoStyle),
1093 // ("see?", Style::Highlight),
1096 // the expected output on a note is (* surround the highlighted text)
1098 // = note: highlighted multiline
1100 // see how it *looks* with
1101 // very *weird* formats
1103 for &(ref text, ref style) in msg.iter() {
1104 let lines = text.split('\n').collect::<Vec<_>>();
1105 if lines.len() > 1 {
1106 for (i, line) in lines.iter().enumerate() {
1109 buffer.append(line_number, &padding, Style::NoStyle);
1111 buffer.append(line_number, line, style_or_override(*style, override_style));
1114 buffer.append(line_number, text, style_or_override(*style, override_style));
1119 fn emit_message_default(
1122 msg: &[(String, Style)],
1123 code: &Option<DiagnosticId>,
1125 max_line_num_len: usize,
1127 ) -> io::Result<()> {
1128 let mut buffer = StyledBuffer::new();
1129 let header_style = if is_secondary {
1132 Style::MainHeaderMsg
1135 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary
1136 && !self.short_message {
1137 // This is a secondary message with no span info
1138 for _ in 0..max_line_num_len {
1139 buffer.prepend(0, " ", Style::NoStyle);
1141 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1142 if *level != Level::FailureNote {
1143 let level_str = level.to_string();
1144 if !level_str.is_empty() {
1145 buffer.append(0, &level_str, Style::MainHeaderMsg);
1146 buffer.append(0, ": ", Style::NoStyle);
1149 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1151 let level_str = level.to_string();
1152 // The failure note level itself does not provide any useful diagnostic information
1153 if *level != Level::FailureNote && !level_str.is_empty() {
1154 buffer.append(0, &level_str, Style::Level(level.clone()));
1156 // only render error codes, not lint codes
1157 if let Some(DiagnosticId::Error(ref code)) = *code {
1158 buffer.append(0, "[", Style::Level(level.clone()));
1159 buffer.append(0, &code, Style::Level(level.clone()));
1160 buffer.append(0, "]", Style::Level(level.clone()));
1162 if *level != Level::FailureNote && !level_str.is_empty() {
1163 buffer.append(0, ": ", header_style);
1165 for &(ref text, _) in msg.iter() {
1166 buffer.append(0, text, header_style);
1170 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1172 // Make sure our primary file comes first
1173 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1174 (self.sm.as_ref(), msp.primary_span().as_ref()) {
1175 if !primary_span.is_dummy() {
1176 (sm.lookup_char_pos(primary_span.lo()), sm)
1178 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1182 // If we don't have span information, emit and exit
1183 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1187 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
1188 annotated_files.swap(0, pos);
1191 // Print out the annotate source lines that correspond with the error
1192 for annotated_file in annotated_files {
1193 // we can't annotate anything if the source is unavailable.
1194 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1198 // print out the span location and spacer before we print the annotated source
1199 // to do this, we need to know if this span will be primary
1200 let is_primary = primary_lo.file.name == annotated_file.file.name;
1202 let loc = primary_lo.clone();
1203 if !self.short_message {
1204 // remember where we are in the output buffer for easy reference
1205 let buffer_msg_line_offset = buffer.num_lines();
1207 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1209 buffer_msg_line_offset,
1213 sm.doctest_offset_line(&loc.file.name, loc.line),
1216 Style::LineAndColumn,
1218 for _ in 0..max_line_num_len {
1219 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1227 sm.doctest_offset_line(&loc.file.name, loc.line),
1230 Style::LineAndColumn,
1233 } else if !self.short_message {
1234 // remember where we are in the output buffer for easy reference
1235 let buffer_msg_line_offset = buffer.num_lines();
1238 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1240 // Then, the secondary file indicator
1241 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1242 let loc = if let Some(first_line) = annotated_file.lines.first() {
1243 let col = if let Some(first_annotation) = first_line.annotations.first() {
1244 format!(":{}", first_annotation.start_col + 1)
1249 annotated_file.file.name,
1250 sm.doctest_offset_line(
1251 &annotated_file.file.name, first_line.line_index),
1254 annotated_file.file.name.to_string()
1256 buffer.append(buffer_msg_line_offset + 1,
1258 Style::LineAndColumn);
1259 for _ in 0..max_line_num_len {
1260 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1264 if !self.short_message {
1265 // Put in the spacer between the location and annotated source
1266 let buffer_msg_line_offset = buffer.num_lines();
1267 draw_col_separator_no_space(&mut buffer,
1268 buffer_msg_line_offset,
1269 max_line_num_len + 1);
1271 // Contains the vertical lines' positions for active multiline annotations
1272 let mut multilines = FxHashMap::default();
1274 // Get the left-side margin to remove it
1275 let mut whitespace_margin = std::usize::MAX;
1276 for line_idx in 0..annotated_file.lines.len() {
1277 let file = annotated_file.file.clone();
1278 let line = &annotated_file.lines[line_idx];
1279 if let Some(source_string) = file.get_line(line.line_index - 1) {
1280 let leading_whitespace = source_string
1282 .take_while(|c| c.is_whitespace())
1284 if source_string.chars().any(|c| !c.is_whitespace()) {
1285 whitespace_margin = min(
1292 if whitespace_margin == std::usize::MAX {
1293 whitespace_margin = 0;
1296 // Left-most column any visible span points at.
1297 let mut span_left_margin = std::usize::MAX;
1298 for line in &annotated_file.lines {
1299 for ann in &line.annotations {
1300 span_left_margin = min(span_left_margin, ann.start_col);
1301 span_left_margin = min(span_left_margin, ann.end_col);
1304 if span_left_margin == std::usize::MAX {
1305 span_left_margin = 0;
1308 // Right-most column any visible span points at.
1309 let mut span_right_margin = 0;
1310 let mut label_right_margin = 0;
1311 let mut max_line_len = 0;
1312 for line in &annotated_file.lines {
1313 max_line_len = max(max_line_len, annotated_file.file
1314 .get_line(line.line_index - 1)
1317 for ann in &line.annotations {
1318 span_right_margin = max(span_right_margin, ann.start_col);
1319 span_right_margin = max(span_right_margin, ann.end_col);
1320 // FIXME: account for labels not in the same line
1321 let label_right = ann.label.as_ref().map(|l| l.len() + 1).unwrap_or(0);
1322 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1326 let width_offset = 3 + max_line_num_len;
1327 let code_offset = if annotated_file.multiline_depth == 0 {
1330 width_offset + annotated_file.multiline_depth + 1
1333 let column_width = if let Some(width) = self.terminal_width {
1334 width.saturating_sub(code_offset)
1335 } else if self.ui_testing {
1338 term_size::dimensions()
1339 .map(|(w, _)| w.saturating_sub(code_offset))
1340 .unwrap_or(std::usize::MAX)
1343 let margin = Margin::new(
1352 // Next, output the annotate source for this file
1353 for line_idx in 0..annotated_file.lines.len() {
1354 let previous_buffer_line = buffer.num_lines();
1356 let depths = self.render_source_line(
1358 annotated_file.file.clone(),
1359 &annotated_file.lines[line_idx],
1365 let mut to_add = FxHashMap::default();
1367 for (depth, style) in depths {
1368 if multilines.get(&depth).is_some() {
1369 multilines.remove(&depth);
1371 to_add.insert(depth, style);
1375 // Set the multiline annotation vertical lines to the left of
1376 // the code in this line.
1377 for (depth, style) in &multilines {
1378 for line in previous_buffer_line..buffer.num_lines() {
1379 draw_multiline_line(&mut buffer,
1386 // check to see if we need to print out or elide lines that come between
1387 // this annotated line and the next one.
1388 if line_idx < (annotated_file.lines.len() - 1) {
1389 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
1390 annotated_file.lines[line_idx].line_index;
1391 if line_idx_delta > 2 {
1392 let last_buffer_line_num = buffer.num_lines();
1393 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1395 // Set the multiline annotation vertical lines on `...` bridging line.
1396 for (depth, style) in &multilines {
1397 draw_multiline_line(&mut buffer,
1398 last_buffer_line_num,
1403 } else if line_idx_delta == 2 {
1404 let unannotated_line = annotated_file.file
1405 .get_line(annotated_file.lines[line_idx].line_index)
1406 .unwrap_or_else(|| Cow::from(""));
1408 let last_buffer_line_num = buffer.num_lines();
1413 annotated_file.lines[line_idx + 1].line_index - 1,
1414 last_buffer_line_num,
1420 for (depth, style) in &multilines {
1421 draw_multiline_line(
1423 last_buffer_line_num,
1432 multilines.extend(&to_add);
1437 // final step: take our styled buffer, render it, then output it
1438 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1444 fn emit_suggestion_default(
1446 suggestion: &CodeSuggestion,
1448 max_line_num_len: usize,
1449 ) -> io::Result<()> {
1450 if let Some(ref sm) = self.sm {
1451 let mut buffer = StyledBuffer::new();
1453 // Render the suggestion message
1454 let level_str = level.to_string();
1455 if !level_str.is_empty() {
1456 buffer.append(0, &level_str, Style::Level(level.clone()));
1457 buffer.append(0, ": ", Style::HeaderMsg);
1461 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1464 Some(Style::HeaderMsg),
1467 // Render the replacements for each suggestion
1468 let suggestions = suggestion.splice_lines(&**sm);
1470 let mut row_num = 2;
1471 for &(ref complete, ref parts) in suggestions.iter().take(MAX_SUGGESTIONS) {
1472 // Only show underline if the suggestion spans a single line and doesn't cover the
1473 // entirety of the code output. If you have multiple replacements in the same line
1474 // of code, show the underline.
1475 let show_underline = !(parts.len() == 1
1476 && parts[0].snippet.trim() == complete.trim())
1477 && complete.lines().count() == 1;
1479 let lines = sm.span_to_lines(parts[0].span).unwrap();
1481 assert!(!lines.lines.is_empty());
1483 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1484 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1485 let mut line_pos = 0;
1486 let mut lines = complete.lines();
1487 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1488 // Print the span column to avoid confusion
1489 buffer.puts(row_num,
1491 &self.maybe_anonymized(line_start + line_pos),
1493 // print the suggestion
1494 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1495 buffer.append(row_num, line, Style::NoStyle);
1500 // This offset and the ones below need to be signed to account for replacement code
1501 // that is shorter than the original code.
1502 let mut offset: isize = 0;
1503 // Only show an underline in the suggestions if the suggestion is not the
1504 // entirety of the code being shown and the displayed code is not multiline.
1506 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1508 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1509 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1511 // Do not underline the leading...
1512 let start = part.snippet.len()
1513 .saturating_sub(part.snippet.trim_start().len());
1514 // ...or trailing spaces. Account for substitutions containing unicode
1516 let sub_len = part.snippet.trim().chars().fold(0, |acc, ch| {
1517 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1)
1520 let underline_start = (span_start_pos + start) as isize + offset;
1521 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1522 for p in underline_start..underline_end {
1523 buffer.putc(row_num,
1524 max_line_num_len + 3 + p as usize,
1526 Style::UnderlinePrimary);
1528 // underline removals too
1529 if underline_start == underline_end {
1530 for p in underline_start-1..underline_start+1 {
1531 buffer.putc(row_num,
1532 max_line_num_len + 3 + p as usize,
1534 Style::UnderlineSecondary);
1538 // length of the code after substitution
1539 let full_sub_len = part.snippet.chars().fold(0, |acc, ch| {
1540 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1) as isize
1543 // length of the code to be substituted
1544 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1545 // For multiple substitutions, use the position *after* the previous
1546 // substitutions have happened.
1547 offset += full_sub_len - snippet_len;
1552 // if we elided some lines, add an ellipsis
1553 if lines.next().is_some() {
1554 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1555 } else if !show_underline {
1556 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1560 if suggestions.len() > MAX_SUGGESTIONS {
1561 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1562 buffer.puts(row_num, 0, &msg, Style::NoStyle);
1564 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1569 fn emit_messages_default(&mut self,
1571 message: &[(String, Style)],
1572 code: &Option<DiagnosticId>,
1574 children: &[SubDiagnostic],
1575 suggestions: &[CodeSuggestion]) {
1576 let max_line_num_len = if self.ui_testing {
1577 ANONYMIZED_LINE_NUM.len()
1579 self.get_max_line_num(span, children).to_string().len()
1582 match self.emit_message_default(span,
1589 if !children.is_empty() {
1590 let mut buffer = StyledBuffer::new();
1591 if !self.short_message {
1592 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1594 match emit_to_destination(&buffer.render(), level, &mut self.dst,
1595 self.short_message) {
1597 Err(e) => panic!("failed to emit error: {}", e)
1600 if !self.short_message {
1601 for child in children {
1602 let span = child.render_span.as_ref().unwrap_or(&child.span);
1603 match self.emit_message_default(
1605 &child.styled_message(),
1611 Err(e) => panic!("failed to emit error: {}", e),
1615 for sugg in suggestions {
1616 if sugg.style == SuggestionStyle::CompletelyHidden {
1617 // do not display this suggestion, it is meant only for tools
1618 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1619 match self.emit_message_default(
1621 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1627 Err(e) => panic!("failed to emit error: {}", e),
1631 match self.emit_suggestion_default(
1636 Err(e) => panic!("failed to emit error: {}", e),
1643 Err(e) => panic!("failed to emit error: {}", e),
1646 let mut dst = self.dst.writable();
1647 match writeln!(dst) {
1648 Err(e) => panic!("failed to emit error: {}", e),
1651 Err(e) => panic!("failed to emit error: {}", e),
1659 impl FileWithAnnotatedLines {
1660 /// Preprocess all the annotations so that they are grouped by file and by line number
1661 /// This helps us quickly iterate over the whole message (including secondary file spans)
1662 pub fn collect_annotations(
1664 source_map: &Option<Lrc<SourceMapperDyn>>
1665 ) -> Vec<FileWithAnnotatedLines> {
1666 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
1667 file: Lrc<SourceFile>,
1671 for slot in file_vec.iter_mut() {
1672 // Look through each of our files for the one we're adding to
1673 if slot.file.name == file.name {
1674 // See if we already have a line for it
1675 for line_slot in &mut slot.lines {
1676 if line_slot.line_index == line_index {
1677 line_slot.annotations.push(ann);
1681 // We don't have a line yet, create one
1682 slot.lines.push(Line {
1684 annotations: vec![ann],
1690 // This is the first time we're seeing the file
1691 file_vec.push(FileWithAnnotatedLines {
1695 annotations: vec![ann],
1701 let mut output = vec![];
1702 let mut multiline_annotations = vec![];
1704 if let Some(ref sm) = source_map {
1705 for span_label in msp.span_labels() {
1706 if span_label.span.is_dummy() {
1710 let lo = sm.lookup_char_pos(span_label.span.lo());
1711 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1713 // Watch out for "empty spans". If we get a span like 6..6, we
1714 // want to just display a `^` at 6, so convert that to
1715 // 6..7. This is degenerate input, but it's best to degrade
1716 // gracefully -- and the parser likes to supply a span like
1717 // that for EOF, in particular.
1719 if lo.col_display == hi.col_display && lo.line == hi.line {
1720 hi.col_display += 1;
1723 let ann_type = if lo.line != hi.line {
1724 let ml = MultilineAnnotation {
1726 line_start: lo.line,
1728 start_col: lo.col_display,
1729 end_col: hi.col_display,
1730 is_primary: span_label.is_primary,
1731 label: span_label.label.clone(),
1732 overlaps_exactly: false,
1734 multiline_annotations.push((lo.file.clone(), ml.clone()));
1735 AnnotationType::Multiline(ml)
1737 AnnotationType::Singleline
1739 let ann = Annotation {
1740 start_col: lo.col_display,
1741 end_col: hi.col_display,
1742 is_primary: span_label.is_primary,
1743 label: span_label.label.clone(),
1744 annotation_type: ann_type,
1747 if !ann.is_multiline() {
1748 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1753 // Find overlapping multiline annotations, put them at different depths
1754 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1755 for item in multiline_annotations.clone() {
1757 for item in multiline_annotations.iter_mut() {
1758 let ref mut a = item.1;
1759 // Move all other multiline annotations overlapping with this one
1760 // one level to the right.
1761 if !(ann.same_span(a)) &&
1762 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1765 } else if ann.same_span(a) && &ann != a {
1766 a.overlaps_exactly = true;
1773 let mut max_depth = 0; // max overlapping multiline spans
1774 for (file, ann) in multiline_annotations {
1775 if ann.depth > max_depth {
1776 max_depth = ann.depth;
1778 let mut end_ann = ann.as_end();
1779 if !ann.overlaps_exactly {
1780 // avoid output like
1802 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1803 // 4 is the minimum vertical length of a multiline span when presented: two lines
1804 // of code and two lines of underline. This is not true for the special case where
1805 // the beginning doesn't have an underline, but the current logic seems to be
1806 // working correctly.
1807 let middle = min(ann.line_start + 4, ann.line_end);
1808 for line in ann.line_start + 1..middle {
1809 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1810 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1812 if middle < ann.line_end - 1 {
1813 for line in ann.line_end - 1..ann.line_end {
1814 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1818 end_ann.annotation_type = AnnotationType::Singleline;
1820 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1822 for file_vec in output.iter_mut() {
1823 file_vec.multiline_depth = max_depth;
1829 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1830 buffer.puts(line, col, "| ", Style::LineNumber);
1833 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1834 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1837 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1841 buffer.putc(line, col, '|', style);
1844 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1845 col_from: usize, col_to: usize, style: Style) {
1846 for col in col_from..col_to {
1847 buffer.putc(line, col, symbol, style);
1851 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1852 buffer.puts(line, col, "= ", Style::LineNumber);
1855 fn draw_multiline_line(buffer: &mut StyledBuffer,
1861 buffer.putc(line, offset + depth - 1, '|', style);
1864 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1865 let extra = if inclusive {
1870 (b_start..b_end + extra).contains(&a_start) ||
1871 (a_start..a_end + extra).contains(&b_start)
1873 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1874 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1877 fn emit_to_destination(rendered_buffer: &[Vec<StyledString>],
1879 dst: &mut Destination,
1880 short_message: bool)
1884 let mut dst = dst.writable();
1886 // In order to prevent error message interleaving, where multiple error lines get intermixed
1887 // when multiple compiler processes error simultaneously, we emit errors with additional
1890 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1891 // the .flush() is called we take the buffer created from the buffered writes and write it at
1892 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1893 // scheme, this buffered approach works and maintains the styling.
1895 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1896 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1897 // enough to output the full error message, then we release.
1898 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1899 for (pos, line) in rendered_buffer.iter().enumerate() {
1901 dst.apply_style(lvl.clone(), part.style)?;
1902 write!(dst, "{}", part.text)?;
1905 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
1913 pub enum Destination {
1914 Terminal(StandardStream),
1915 Buffered(BufferWriter),
1916 // The bool denotes whether we should be emitting ansi color codes or not
1917 Raw(Box<(dyn Write + Send)>, bool),
1920 pub enum WritableDst<'a> {
1921 Terminal(&'a mut StandardStream),
1922 Buffered(&'a mut BufferWriter, Buffer),
1923 Raw(&'a mut (dyn Write + Send)),
1924 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
1928 fn from_stderr(color: ColorConfig) -> Destination {
1929 let choice = color.to_color_choice();
1930 // On Windows we'll be performing global synchronization on the entire
1931 // system for emitting rustc errors, so there's no need to buffer
1934 // On non-Windows we rely on the atomicity of `write` to ensure errors
1935 // don't get all jumbled up.
1937 Terminal(StandardStream::stderr(choice))
1939 Buffered(BufferWriter::stderr(choice))
1943 fn writable(&mut self) -> WritableDst<'_> {
1945 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
1946 Destination::Buffered(ref mut t) => {
1947 let buf = t.buffer();
1948 WritableDst::Buffered(t, buf)
1950 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
1951 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
1956 impl<'a> WritableDst<'a> {
1957 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1958 let mut spec = ColorSpec::new();
1960 Style::LineAndColumn => {}
1961 Style::LineNumber => {
1962 spec.set_bold(true);
1963 spec.set_intense(true);
1965 spec.set_fg(Some(Color::Cyan));
1967 spec.set_fg(Some(Color::Blue));
1970 Style::Quotation => {}
1971 Style::MainHeaderMsg => {
1972 spec.set_bold(true);
1974 spec.set_intense(true)
1975 .set_fg(Some(Color::White));
1978 Style::UnderlinePrimary | Style::LabelPrimary => {
1980 spec.set_bold(true);
1982 Style::UnderlineSecondary |
1983 Style::LabelSecondary => {
1987 spec.set_fg(Some(Color::Cyan));
1989 spec.set_fg(Some(Color::Blue));
1993 Style::NoStyle => {}
1994 Style::Level(lvl) => {
1996 spec.set_bold(true);
1998 Style::Highlight => {
1999 spec.set_bold(true);
2002 self.set_color(&spec)
2005 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2007 WritableDst::Terminal(ref mut t) => t.set_color(color),
2008 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2009 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2010 WritableDst::Raw(_) => Ok(())
2014 fn reset(&mut self) -> io::Result<()> {
2016 WritableDst::Terminal(ref mut t) => t.reset(),
2017 WritableDst::Buffered(_, ref mut t) => t.reset(),
2018 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2019 WritableDst::Raw(_) => Ok(()),
2024 impl<'a> Write for WritableDst<'a> {
2025 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2027 WritableDst::Terminal(ref mut t) => t.write(bytes),
2028 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2029 WritableDst::Raw(ref mut w) => w.write(bytes),
2030 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2034 fn flush(&mut self) -> io::Result<()> {
2036 WritableDst::Terminal(ref mut t) => t.flush(),
2037 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2038 WritableDst::Raw(ref mut w) => w.flush(),
2039 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2044 impl<'a> Drop for WritableDst<'a> {
2045 fn drop(&mut self) {
2047 WritableDst::Buffered(ref mut dst, ref mut buf) => {
2048 drop(dst.print(buf));