1 //! The current rustc diagnostics emitter.
3 //! An `Emitter` takes care of generating the output from a `DiagnosticBuilder` struct.
5 //! There are various `Emitter` implementations that generate different output formats such as
6 //! JSON and human readable output.
8 //! The output types are defined in `rustc_session::config::ErrorOutputType`.
12 use rustc_span::source_map::SourceMap;
13 use rustc_span::{MultiSpan, SourceFile, Span};
15 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
16 use crate::styled_buffer::StyledBuffer;
18 pluralize, CodeSuggestion, Diagnostic, DiagnosticId, Level, SubDiagnostic, SuggestionStyle,
21 use rustc_data_structures::fx::FxHashMap;
22 use rustc_data_structures::sync::Lrc;
23 use rustc_span::hygiene::{ExpnKind, MacroKind};
25 use std::cmp::{max, min, Reverse};
27 use std::io::prelude::*;
30 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
31 use termcolor::{Buffer, Color, WriteColor};
34 /// Default column width, used in tests and when terminal dimensions cannot be determined.
35 const DEFAULT_COLUMN_WIDTH: usize = 140;
37 /// Describes the way the content of the `rendered` field of the json output is generated
38 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
39 pub enum HumanReadableErrorType {
41 AnnotateSnippet(ColorConfig),
45 impl HumanReadableErrorType {
46 /// Returns a (`short`, `color`) tuple
47 pub fn unzip(self) -> (bool, ColorConfig) {
49 HumanReadableErrorType::Default(cc) => (false, cc),
50 HumanReadableErrorType::Short(cc) => (true, cc),
51 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
56 dst: Box<dyn Write + Send>,
57 source_map: Option<Lrc<SourceMap>>,
59 terminal_width: Option<usize>,
60 macro_backtrace: bool,
62 let (short, color_config) = self.unzip();
63 let color = color_config.suggests_using_colors();
64 EmitterWriter::new(dst, source_map, short, teach, color, terminal_width, macro_backtrace)
68 #[derive(Clone, Copy, Debug)]
70 /// The available whitespace in the left that can be consumed when centering.
71 pub whitespace_left: usize,
72 /// The column of the beginning of left-most span.
74 /// The column of the end of right-most span.
75 pub span_right: usize,
76 /// The beginning of the line to be displayed.
77 pub computed_left: usize,
78 /// The end of the line to be displayed.
79 pub computed_right: usize,
80 /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default
82 pub column_width: usize,
83 /// The end column of a span label, including the span. Doesn't account for labels not in the
84 /// same line as the span.
85 pub label_right: usize,
90 whitespace_left: usize,
97 // The 6 is padding to give a bit of room for `...` when displaying:
102 // 16 | ... fn foo(self) -> Self::Bar {
107 whitespace_left: whitespace_left.saturating_sub(6),
108 span_left: span_left.saturating_sub(6),
109 span_right: span_right + 6,
113 label_right: label_right + 6,
115 m.compute(max_line_len);
119 fn was_cut_left(&self) -> bool {
120 self.computed_left > 0
123 fn was_cut_right(&self, line_len: usize) -> bool {
125 if self.computed_right == self.span_right || self.computed_right == self.label_right {
126 // Account for the "..." padding given above. Otherwise we end up with code lines that
127 // do fit but end in "..." as if they were trimmed.
128 self.computed_right - 6
132 right < line_len && self.computed_left + self.column_width < line_len
135 fn compute(&mut self, max_line_len: usize) {
136 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
137 self.computed_left = if self.whitespace_left > 20 {
138 self.whitespace_left - 16 // We want some padding.
142 // We want to show as much as possible, max_line_len is the right-most boundary for the
144 self.computed_right = max(max_line_len, self.computed_left);
146 if self.computed_right - self.computed_left > self.column_width {
147 // Trimming only whitespace isn't enough, let's get craftier.
148 if self.label_right - self.whitespace_left <= self.column_width {
149 // Attempt to fit the code window only trimming whitespace.
150 self.computed_left = self.whitespace_left;
151 self.computed_right = self.computed_left + self.column_width;
152 } else if self.label_right - self.span_left <= self.column_width {
153 // Attempt to fit the code window considering only the spans and labels.
154 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
155 self.computed_left = self.span_left.saturating_sub(padding_left);
156 self.computed_right = self.computed_left + self.column_width;
157 } else if self.span_right - self.span_left <= self.column_width {
158 // Attempt to fit the code window considering the spans and labels plus padding.
159 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
160 self.computed_left = self.span_left.saturating_sub(padding_left);
161 self.computed_right = self.computed_left + self.column_width;
163 // Mostly give up but still don't show the full line.
164 self.computed_left = self.span_left;
165 self.computed_right = self.span_right;
170 fn left(&self, line_len: usize) -> usize {
171 min(self.computed_left, line_len)
174 fn right(&self, line_len: usize) -> usize {
175 if line_len.saturating_sub(self.computed_left) <= self.column_width {
178 min(line_len, self.computed_right)
183 const ANONYMIZED_LINE_NUM: &str = "LL";
185 /// Emitter trait for emitting errors.
187 /// Emit a structured diagnostic.
188 fn emit_diagnostic(&mut self, diag: &Diagnostic);
190 /// Emit a notification that an artifact has been output.
191 /// This is currently only supported for the JSON format,
192 /// other formats can, and will, simply ignore it.
193 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
195 /// Checks if should show explanations about "rustc --explain"
196 fn should_show_explain(&self) -> bool {
200 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
202 /// Formats the substitutions of the primary_span
204 /// The are a lot of conditions to this method, but in short:
206 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
207 /// we format the `help` suggestion depending on the content of the
208 /// substitutions. In that case, we return the modified span only.
210 /// * If the current `Diagnostic` has multiple suggestions,
211 /// we return the original `primary_span` and the original suggestions.
212 fn primary_span_formatted<'a>(
214 diag: &'a Diagnostic,
215 ) -> (MultiSpan, &'a [CodeSuggestion]) {
216 let mut primary_span = diag.span.clone();
217 if let Some((sugg, rest)) = diag.suggestions.split_first() {
218 if rest.is_empty() &&
219 // ^ if there is only one suggestion
220 // don't display multi-suggestions as labels
221 sugg.substitutions.len() == 1 &&
222 // don't display multipart suggestions as labels
223 sugg.substitutions[0].parts.len() == 1 &&
224 // don't display long messages as labels
225 sugg.msg.split_whitespace().count() < 10 &&
226 // don't display multiline suggestions as labels
227 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
229 // when this style is set we want the suggestion to be a message, not inline
230 SuggestionStyle::HideCodeAlways,
231 // trivial suggestion for tooling's sake, never shown
232 SuggestionStyle::CompletelyHidden,
233 // subtle suggestion, never shown inline
234 SuggestionStyle::ShowAlways,
235 ].contains(&sugg.style)
237 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
238 let msg = if substitution.is_empty() || sugg.style.hide_inline() {
239 // This substitution is only removal OR we explicitly don't want to show the
240 // code inline (`hide_inline`). Therefore, we don't show the substitution.
241 format!("help: {}", sugg.msg)
243 // Show the default suggestion text with the substitution
249 .map(|sm| is_case_difference(
252 sugg.substitutions[0].parts[0].span,
256 " (notice the capitalization)"
263 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
265 // We return only the modified primary_span
268 // if there are multiple suggestions, print them all in full
269 // to be consistent. We could try to figure out if we can
270 // make one (or the first one) inline, but that would give
271 // undue importance to a semi-random suggestion
272 (primary_span, &diag.suggestions)
275 (primary_span, &diag.suggestions)
279 fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
281 source_map: &Option<Lrc<SourceMap>>,
282 span: &mut MultiSpan,
283 children: &mut Vec<SubDiagnostic>,
287 // Check for spans in macros, before `fix_multispans_in_extern_macros`
288 // has a chance to replace them.
289 let has_macro_spans = iter::once(&*span)
290 .chain(children.iter().map(|child| &child.span))
291 .flat_map(|span| span.primary_spans())
292 .flat_map(|sp| sp.macro_backtrace())
293 .find_map(|expn_data| {
294 match expn_data.kind {
295 ExpnKind::Root => None,
297 // Skip past non-macro entries, just in case there
298 // are some which do actually involve macros.
299 ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
301 ExpnKind::Macro(macro_kind, _) => Some(macro_kind),
306 self.fix_multispans_in_extern_macros(source_map, span, children);
309 self.render_multispans_macro_backtrace(span, children, backtrace);
312 if let Some(macro_kind) = has_macro_spans {
314 "this {} originates in {} {} \
315 (in Nightly builds, run with -Z macro-backtrace for more info)",
317 macro_kind.article(),
321 children.push(SubDiagnostic {
323 message: vec![(msg, Style::NoStyle)],
324 span: MultiSpan::new(),
331 fn render_multispans_macro_backtrace(
333 span: &mut MultiSpan,
334 children: &mut Vec<SubDiagnostic>,
337 for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
338 self.render_multispan_macro_backtrace(span, backtrace);
342 fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
343 let mut new_labels: Vec<(Span, String)> = vec![];
345 for &sp in span.primary_spans() {
350 // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
351 // entries we don't want to print, to make sure the indices being
352 // printed are contiguous (or omitted if there's only one entry).
353 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
354 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
355 if trace.def_site.is_dummy() {
359 if always_backtrace {
363 "in this expansion of `{}`{}",
365 if macro_backtrace.len() > 1 {
366 // if macro_backtrace.len() == 1 it'll be
367 // pointed at by "in this macro invocation"
368 format!(" (#{})", i + 1)
376 // Don't add a label on the call site if the diagnostic itself
377 // already points to (a part of) that call site, as the label
378 // is meant for showing the relevant invocation when the actual
379 // diagnostic is pointing to some part of macro definition.
381 // This also handles the case where an external span got replaced
382 // with the call site span by `fix_multispans_in_extern_macros`.
384 // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
385 // "in this expansion of" label above is always added in that mode,
386 // and it needs an "in this macro invocation" label to match that.
387 let redundant_span = trace.call_site.contains(sp);
389 if !redundant_span && matches!(trace.kind, ExpnKind::Macro(MacroKind::Bang, _))
395 "in this macro invocation{}",
396 if macro_backtrace.len() > 1 && always_backtrace {
397 // only specify order when the macro
398 // backtrace is multiple levels deep
399 format!(" (#{})", i + 1)
406 if !always_backtrace {
412 for (label_span, label_text) in new_labels {
413 span.push_span_label(label_span, label_text);
417 // This does a small "fix" for multispans by looking to see if it can find any that
418 // point directly at external macros. Since these are often difficult to read,
419 // this will change the span to point at the use site.
420 fn fix_multispans_in_extern_macros(
422 source_map: &Option<Lrc<SourceMap>>,
423 span: &mut MultiSpan,
424 children: &mut Vec<SubDiagnostic>,
426 debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
427 for span in iter::once(&mut *span).chain(children.iter_mut().map(|child| &mut child.span)) {
428 self.fix_multispan_in_extern_macros(source_map, span);
430 debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
433 // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
434 // Since these locations are often difficult to read,
435 // we move these spans from the external macros to their corresponding use site.
436 fn fix_multispan_in_extern_macros(
438 source_map: &Option<Lrc<SourceMap>>,
439 span: &mut MultiSpan,
441 let sm = match source_map {
446 // First, find all the spans in external macros and point instead at their use site.
447 let replacements: Vec<(Span, Span)> = span
451 .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
453 if !sp.is_dummy() && sm.is_imported(sp) {
454 let maybe_callsite = sp.source_callsite();
455 if sp != maybe_callsite {
456 return Some((sp, maybe_callsite));
463 // After we have them, make sure we replace these 'bad' def sites with their use sites.
464 for (from, to) in replacements {
465 span.replace(from, to);
470 impl Emitter for EmitterWriter {
471 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
475 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
476 let mut children = diag.children.clone();
477 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
478 debug!("emit_diagnostic: suggestions={:?}", suggestions);
480 self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
485 self.macro_backtrace,
488 self.emit_messages_default(
490 &diag.styled_message(),
498 fn should_show_explain(&self) -> bool {
503 /// An emitter that does nothing when emitting a diagnostic.
504 pub struct SilentEmitter;
506 impl Emitter for SilentEmitter {
507 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
510 fn emit_diagnostic(&mut self, _: &Diagnostic) {}
513 /// Maximum number of lines we will print for each error; arbitrary.
514 pub const MAX_HIGHLIGHT_LINES: usize = 6;
515 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
517 /// This should be replaced with a more involved mechanism to output multiline suggestions that
518 /// more closely mimmics the regular diagnostic output, where irrelevant code lines are elided.
519 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
520 /// Maximum number of suggestions to be shown
522 /// Arbitrary, but taken from trait import suggestion limit
523 pub const MAX_SUGGESTIONS: usize = 4;
525 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
526 pub enum ColorConfig {
533 fn to_color_choice(self) -> ColorChoice {
535 ColorConfig::Always => {
536 if atty::is(atty::Stream::Stderr) {
539 ColorChoice::AlwaysAnsi
542 ColorConfig::Never => ColorChoice::Never,
543 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
544 ColorConfig::Auto => ColorChoice::Never,
547 fn suggests_using_colors(self) -> bool {
549 ColorConfig::Always | ColorConfig::Auto => true,
550 ColorConfig::Never => false,
555 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
556 pub struct EmitterWriter {
558 sm: Option<Lrc<SourceMap>>,
562 terminal_width: Option<usize>,
564 macro_backtrace: bool,
568 pub struct FileWithAnnotatedLines {
569 pub file: Lrc<SourceFile>,
570 pub lines: Vec<Line>,
571 multiline_depth: usize,
576 color_config: ColorConfig,
577 source_map: Option<Lrc<SourceMap>>,
580 terminal_width: Option<usize>,
581 macro_backtrace: bool,
583 let dst = Destination::from_stderr(color_config);
596 dst: Box<dyn Write + Send>,
597 source_map: Option<Lrc<SourceMap>>,
601 terminal_width: Option<usize>,
602 macro_backtrace: bool,
605 dst: Raw(dst, colored),
615 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
616 self.ui_testing = ui_testing;
620 fn maybe_anonymized(&self, line_num: usize) -> String {
621 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
626 buffer: &mut StyledBuffer,
634 let line_len = source_string.len();
635 // Create the source line we will highlight.
636 let left = margin.left(line_len);
637 let right = margin.right(line_len);
638 // On long lines, we strip the source line, accounting for unicode.
640 let code: String = source_string
644 // Make sure that the trimming on the right will fall within the terminal width.
645 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
646 // For now, just accept that sometimes the code line will be longer than desired.
647 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
648 if taken + next > right - left {
655 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
656 if margin.was_cut_left() {
657 // We have stripped some code/whitespace from the beginning, make it clear.
658 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
660 if margin.was_cut_right(line_len) {
661 // We have stripped some code after the right-most span end, make it clear we did so.
662 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
664 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
666 draw_col_separator(buffer, line_offset, width_offset - 2);
669 fn render_source_line(
671 buffer: &mut StyledBuffer,
672 file: Lrc<SourceFile>,
677 ) -> Vec<(usize, Style)> {
683 // | secondary span label
685 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
687 // | | | actual code found in your source code and the spans we use to mark it
688 // | | when there's too much wasted space to the left, trim it
689 // | vertical divider between the column number and the code
692 if line.line_index == 0 {
696 let source_string = match file.get_line(line.line_index - 1) {
698 None => return Vec::new(),
701 let line_offset = buffer.num_lines();
703 let left = margin.left(source_string.len()); // Left trim
704 // Account for unicode characters of width !=0 that were removed.
705 let left = source_string
708 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
721 // Special case when there's only one annotation involved, it is the start of a multiline
722 // span and there's no text at the beginning of the code line. Instead of doing the whole
731 // we simplify the output to:
737 if let [ann] = &line.annotations[..] {
738 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
739 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
740 let style = if ann.is_primary {
741 Style::UnderlinePrimary
743 Style::UnderlineSecondary
745 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
746 return vec![(depth, style)];
751 // We want to display like this:
753 // vec.push(vec.pop().unwrap());
754 // --- ^^^ - previous borrow ends here
756 // | error occurs here
757 // previous borrow of `vec` occurs here
759 // But there are some weird edge cases to be aware of:
761 // vec.push(vec.pop().unwrap());
762 // -------- - previous borrow ends here
764 // |this makes no sense
765 // previous borrow of `vec` occurs here
767 // For this reason, we group the lines into "highlight lines"
768 // and "annotations lines", where the highlight lines have the `^`.
770 // Sort the annotations by (start, end col)
771 // The labels are reversed, sort and then reversed again.
772 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
773 // the letter signifies the span. Here we are only sorting by the
774 // span and hence, the order of the elements with the same span will
775 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
776 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
777 // still ordered first to last, but all the elements with different
778 // spans are ordered by their spans in last to first order. Last to
779 // first order is important, because the jiggly lines and | are on
780 // the left, so the rightmost span needs to be rendered first,
781 // otherwise the lines would end up needing to go over a message.
783 let mut annotations = line.annotations.clone();
784 annotations.sort_by_key(|a| Reverse(a.start_col));
786 // First, figure out where each label will be positioned.
788 // In the case where you have the following annotations:
790 // vec.push(vec.pop().unwrap());
791 // -------- - previous borrow ends here [C]
793 // |this makes no sense [B]
794 // previous borrow of `vec` occurs here [A]
796 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
798 // We try, when possible, to stick the rightmost annotation at the end
799 // of the highlight line:
801 // vec.push(vec.pop().unwrap());
802 // --- --- - previous borrow ends here
804 // But sometimes that's not possible because one of the other
805 // annotations overlaps it. For example, from the test
806 // `span_overlap_label`, we have the following annotations
807 // (written on distinct lines for clarity):
813 // In this case, we can't stick the rightmost-most label on
814 // the highlight line, or we would get:
821 // which is totally weird. Instead we want:
829 // which is...less weird, at least. In fact, in general, if
830 // the rightmost span overlaps with any other span, we should
831 // use the "hang below" version, so we can at least make it
832 // clear where the span *starts*. There's an exception for this
833 // logic, when the labels do not have a message:
848 let mut annotations_position = vec![];
849 let mut line_len = 0;
851 for (i, annotation) in annotations.iter().enumerate() {
852 for (j, next) in annotations.iter().enumerate() {
853 if overlaps(next, annotation, 0) // This label overlaps with another one and both
854 && annotation.has_label() // take space (they have text and are not
855 && j > i // multiline lines).
857 // We're currently on the first line, move the label one line down
859 // If we're overlapping with an un-labelled annotation with the same span
860 // we can just merge them in the output
861 if next.start_col == annotation.start_col
862 && next.end_col == annotation.end_col
868 // This annotation needs a new line in the output.
873 annotations_position.push((p, annotation));
874 for (j, next) in annotations.iter().enumerate() {
876 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
877 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
878 // line if they overlap including padding, to
879 // avoid situations like:
886 && annotation.has_label() // Both labels must have some text, otherwise
887 && next.has_label()) // they are not overlapping.
888 // Do not add a new line if this annotation
889 // or the next are vertical line placeholders.
890 || (annotation.takes_space() // If either this or the next annotation is
891 && next.has_label()) // multiline start/end, move it to a new line
892 || (annotation.has_label() // so as not to overlap the orizontal lines.
893 && next.takes_space())
894 || (annotation.takes_space() && next.takes_space())
895 || (overlaps(next, annotation, l)
896 && next.end_col <= annotation.end_col
901 // This annotation needs a new line in the output.
907 line_len = max(line_len, p);
914 // If there are no annotations or the only annotations on this line are
915 // MultilineLine, then there's only code being shown, stop processing.
916 if line.annotations.iter().all(|a| a.is_line()) {
920 // Write the column separator.
922 // After this we will have:
931 for pos in 0..=line_len {
932 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
933 buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber);
936 // Write the horizontal lines for multiline annotations
937 // (only the first and last lines need this).
939 // After this we will have:
948 for &(pos, annotation) in &annotations_position {
949 let style = if annotation.is_primary {
950 Style::UnderlinePrimary
952 Style::UnderlineSecondary
955 match annotation.annotation_type {
956 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
961 width_offset + depth,
962 (code_offset + annotation.start_col).saturating_sub(left),
967 buffer.set_style_range(
969 (code_offset + annotation.start_col).saturating_sub(left),
970 (code_offset + annotation.end_col).saturating_sub(left),
972 annotation.is_primary,
979 // Write the vertical lines for labels that are on a different line as the underline.
981 // After this we will have:
990 for &(pos, annotation) in &annotations_position {
991 let style = if annotation.is_primary {
992 Style::UnderlinePrimary
994 Style::UnderlineSecondary
998 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
999 for p in line_offset + 1..=line_offset + pos {
1002 (code_offset + annotation.start_col).saturating_sub(left),
1008 match annotation.annotation_type {
1009 AnnotationType::MultilineStart(depth) => {
1010 for p in line_offset + pos + 1..line_offset + line_len + 2 {
1011 buffer.putc(p, width_offset + depth - 1, '|', style);
1014 AnnotationType::MultilineEnd(depth) => {
1015 for p in line_offset..=line_offset + pos {
1016 buffer.putc(p, width_offset + depth - 1, '|', style);
1023 // Write the labels on the annotations that actually have a label.
1025 // After this we will have:
1030 // | something about `foo`
1034 for &(pos, annotation) in &annotations_position {
1036 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1037 let (pos, col) = if pos == 0 {
1038 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1040 (pos + 2, annotation.start_col.saturating_sub(left))
1042 if let Some(ref label) = annotation.label {
1043 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1047 // Sort from biggest span to smallest span so that smaller spans are
1048 // represented in the output:
1053 // | | something about `foo`
1054 // | something about `fn foo()`
1055 annotations_position.sort_by_key(|(_, ann)| {
1056 // Decreasing order. When annotations share the same length, prefer `Primary`.
1057 (Reverse(ann.len()), ann.is_primary)
1060 // Write the underlines.
1062 // After this we will have:
1067 // | something about `foo`
1071 for &(_, annotation) in &annotations_position {
1072 let (underline, style) = if annotation.is_primary {
1073 ('^', Style::UnderlinePrimary)
1075 ('-', Style::UnderlineSecondary)
1077 for p in annotation.start_col..annotation.end_col {
1080 (code_offset + p).saturating_sub(left),
1086 annotations_position
1088 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1089 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1090 let style = if annotation.is_primary {
1093 Style::LabelSecondary
1099 .collect::<Vec<_>>()
1102 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1103 let sm = match self.sm {
1109 for primary_span in msp.primary_spans() {
1110 if !primary_span.is_dummy() {
1111 let hi = sm.lookup_char_pos(primary_span.hi());
1112 max = (hi.line).max(max);
1115 if !self.short_message {
1116 for span_label in msp.span_labels() {
1117 if !span_label.span.is_dummy() {
1118 let hi = sm.lookup_char_pos(span_label.span.hi());
1119 max = (hi.line).max(max);
1127 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1128 let primary = self.get_multispan_max_line_num(span);
1131 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1137 /// Adds a left margin to every line but the first, given a padding length and the label being
1138 /// displayed, keeping the provided highlighting.
1141 buffer: &mut StyledBuffer,
1142 msg: &[(String, Style)],
1145 override_style: Option<Style>,
1147 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1150 // --> file.rs:13:20
1155 // = note: multiline
1160 // | | length of label
1162 // `max_line_num_len`
1163 let padding = " ".repeat(padding + label.len() + 5);
1165 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1166 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1167 match (style, override_) {
1168 (Style::NoStyle, Some(override_)) => override_,
1173 let mut line_number = 0;
1175 // Provided the following diagnostic message:
1179 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1180 // ("looks", Style::Highlight),
1181 // ("with\nvery ", Style::NoStyle),
1182 // ("weird", Style::Highlight),
1183 // (" formats\n", Style::NoStyle),
1184 // ("see?", Style::Highlight),
1187 // the expected output on a note is (* surround the highlighted text)
1189 // = note: highlighted multiline
1191 // see how it *looks* with
1192 // very *weird* formats
1194 for &(ref text, ref style) in msg.iter() {
1195 let lines = text.split('\n').collect::<Vec<_>>();
1196 if lines.len() > 1 {
1197 for (i, line) in lines.iter().enumerate() {
1200 buffer.append(line_number, &padding, Style::NoStyle);
1202 buffer.append(line_number, line, style_or_override(*style, override_style));
1205 buffer.append(line_number, text, style_or_override(*style, override_style));
1210 fn emit_message_default(
1213 msg: &[(String, Style)],
1214 code: &Option<DiagnosticId>,
1216 max_line_num_len: usize,
1218 ) -> io::Result<()> {
1219 let mut buffer = StyledBuffer::new();
1220 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1222 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1224 // This is a secondary message with no span info
1225 for _ in 0..max_line_num_len {
1226 buffer.prepend(0, " ", Style::NoStyle);
1228 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1229 if *level != Level::FailureNote {
1230 buffer.append(0, level.to_str(), Style::MainHeaderMsg);
1231 buffer.append(0, ": ", Style::NoStyle);
1233 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1235 // The failure note level itself does not provide any useful diagnostic information
1236 if *level != Level::FailureNote {
1237 buffer.append(0, level.to_str(), Style::Level(*level));
1239 // only render error codes, not lint codes
1240 if let Some(DiagnosticId::Error(ref code)) = *code {
1241 buffer.append(0, "[", Style::Level(*level));
1242 buffer.append(0, &code, Style::Level(*level));
1243 buffer.append(0, "]", Style::Level(*level));
1245 if *level != Level::FailureNote {
1246 buffer.append(0, ": ", header_style);
1248 for &(ref text, _) in msg.iter() {
1249 buffer.append(0, text, header_style);
1253 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1255 // Make sure our primary file comes first
1256 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1257 (self.sm.as_ref(), msp.primary_span().as_ref())
1259 if !primary_span.is_dummy() {
1260 (sm.lookup_char_pos(primary_span.lo()), sm)
1262 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1266 // If we don't have span information, emit and exit
1267 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1271 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1273 annotated_files.swap(0, pos);
1276 // Print out the annotate source lines that correspond with the error
1277 for annotated_file in annotated_files {
1278 // we can't annotate anything if the source is unavailable.
1279 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1283 // print out the span location and spacer before we print the annotated source
1284 // to do this, we need to know if this span will be primary
1285 let is_primary = primary_lo.file.name == annotated_file.file.name;
1287 let loc = primary_lo.clone();
1288 if !self.short_message {
1289 // remember where we are in the output buffer for easy reference
1290 let buffer_msg_line_offset = buffer.num_lines();
1292 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1294 buffer_msg_line_offset,
1298 sm.doctest_offset_line(&loc.file.name, loc.line),
1301 Style::LineAndColumn,
1303 for _ in 0..max_line_num_len {
1304 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1312 sm.doctest_offset_line(&loc.file.name, loc.line),
1315 Style::LineAndColumn,
1318 } else if !self.short_message {
1319 // remember where we are in the output buffer for easy reference
1320 let buffer_msg_line_offset = buffer.num_lines();
1323 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1325 // Then, the secondary file indicator
1326 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1327 let loc = if let Some(first_line) = annotated_file.lines.first() {
1328 let col = if let Some(first_annotation) = first_line.annotations.first() {
1329 format!(":{}", first_annotation.start_col + 1)
1335 annotated_file.file.name,
1336 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1340 annotated_file.file.name.to_string()
1342 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1343 for _ in 0..max_line_num_len {
1344 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1348 if !self.short_message {
1349 // Put in the spacer between the location and annotated source
1350 let buffer_msg_line_offset = buffer.num_lines();
1351 draw_col_separator_no_space(
1353 buffer_msg_line_offset,
1354 max_line_num_len + 1,
1357 // Contains the vertical lines' positions for active multiline annotations
1358 let mut multilines = FxHashMap::default();
1360 // Get the left-side margin to remove it
1361 let mut whitespace_margin = usize::MAX;
1362 for line_idx in 0..annotated_file.lines.len() {
1363 let file = annotated_file.file.clone();
1364 let line = &annotated_file.lines[line_idx];
1365 if let Some(source_string) = file.get_line(line.line_index - 1) {
1366 let leading_whitespace =
1367 source_string.chars().take_while(|c| c.is_whitespace()).count();
1368 if source_string.chars().any(|c| !c.is_whitespace()) {
1369 whitespace_margin = min(whitespace_margin, leading_whitespace);
1373 if whitespace_margin == usize::MAX {
1374 whitespace_margin = 0;
1377 // Left-most column any visible span points at.
1378 let mut span_left_margin = usize::MAX;
1379 for line in &annotated_file.lines {
1380 for ann in &line.annotations {
1381 span_left_margin = min(span_left_margin, ann.start_col);
1382 span_left_margin = min(span_left_margin, ann.end_col);
1385 if span_left_margin == usize::MAX {
1386 span_left_margin = 0;
1389 // Right-most column any visible span points at.
1390 let mut span_right_margin = 0;
1391 let mut label_right_margin = 0;
1392 let mut max_line_len = 0;
1393 for line in &annotated_file.lines {
1396 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1398 for ann in &line.annotations {
1399 span_right_margin = max(span_right_margin, ann.start_col);
1400 span_right_margin = max(span_right_margin, ann.end_col);
1401 // FIXME: account for labels not in the same line
1402 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1403 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1407 let width_offset = 3 + max_line_num_len;
1408 let code_offset = if annotated_file.multiline_depth == 0 {
1411 width_offset + annotated_file.multiline_depth + 1
1414 let column_width = if let Some(width) = self.terminal_width {
1415 width.saturating_sub(code_offset)
1416 } else if self.ui_testing {
1417 DEFAULT_COLUMN_WIDTH
1419 termize::dimensions()
1420 .map(|(w, _)| w.saturating_sub(code_offset))
1421 .unwrap_or(DEFAULT_COLUMN_WIDTH)
1424 let margin = Margin::new(
1433 // Next, output the annotate source for this file
1434 for line_idx in 0..annotated_file.lines.len() {
1435 let previous_buffer_line = buffer.num_lines();
1437 let depths = self.render_source_line(
1439 annotated_file.file.clone(),
1440 &annotated_file.lines[line_idx],
1446 let mut to_add = FxHashMap::default();
1448 for (depth, style) in depths {
1449 if multilines.get(&depth).is_some() {
1450 multilines.remove(&depth);
1452 to_add.insert(depth, style);
1456 // Set the multiline annotation vertical lines to the left of
1457 // the code in this line.
1458 for (depth, style) in &multilines {
1459 for line in previous_buffer_line..buffer.num_lines() {
1460 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1463 // check to see if we need to print out or elide lines that come between
1464 // this annotated line and the next one.
1465 if line_idx < (annotated_file.lines.len() - 1) {
1466 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1467 - annotated_file.lines[line_idx].line_index;
1468 if line_idx_delta > 2 {
1469 let last_buffer_line_num = buffer.num_lines();
1470 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1472 // Set the multiline annotation vertical lines on `...` bridging line.
1473 for (depth, style) in &multilines {
1474 draw_multiline_line(
1476 last_buffer_line_num,
1482 } else if line_idx_delta == 2 {
1483 let unannotated_line = annotated_file
1485 .get_line(annotated_file.lines[line_idx].line_index)
1486 .unwrap_or_else(|| Cow::from(""));
1488 let last_buffer_line_num = buffer.num_lines();
1493 annotated_file.lines[line_idx + 1].line_index - 1,
1494 last_buffer_line_num,
1500 for (depth, style) in &multilines {
1501 draw_multiline_line(
1503 last_buffer_line_num,
1512 multilines.extend(&to_add);
1517 // final step: take our styled buffer, render it, then output it
1518 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1523 fn emit_suggestion_default(
1525 suggestion: &CodeSuggestion,
1527 max_line_num_len: usize,
1528 ) -> io::Result<()> {
1529 let sm = match self.sm {
1531 None => return Ok(()),
1534 // Render the replacements for each suggestion
1535 let suggestions = suggestion.splice_lines(&**sm);
1536 debug!("emit_suggestion_default: suggestions={:?}", suggestions);
1538 if suggestions.is_empty() {
1539 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1540 // approach to avoid ICEs by ignoring the suggestion outright.
1544 let mut buffer = StyledBuffer::new();
1546 // Render the suggestion message
1547 buffer.append(0, level.to_str(), Style::Level(*level));
1548 buffer.append(0, ": ", Style::HeaderMsg);
1552 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1555 Some(Style::HeaderMsg),
1558 let mut row_num = 2;
1559 let mut notice_capitalization = false;
1560 for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
1561 notice_capitalization |= only_capitalization;
1562 // Only show underline if the suggestion spans a single line and doesn't cover the
1563 // entirety of the code output. If you have multiple replacements in the same line
1564 // of code, show the underline.
1565 let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
1566 && complete.lines().count() == 1;
1569 .span_to_lines(parts[0].span)
1570 .expect("span_to_lines failed when emitting suggestion");
1572 assert!(!lines.lines.is_empty() || parts[0].span.is_dummy());
1574 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1575 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1576 let mut lines = complete.lines();
1577 for (line_pos, line) in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES).enumerate()
1579 // Print the span column to avoid confusion
1583 &self.maybe_anonymized(line_start + line_pos),
1586 // print the suggestion
1587 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1588 buffer.append(row_num, line, Style::NoStyle);
1592 // This offset and the ones below need to be signed to account for replacement code
1593 // that is shorter than the original code.
1594 let mut offsets: Vec<(usize, isize)> = Vec::new();
1595 // Only show an underline in the suggestions if the suggestion is not the
1596 // entirety of the code being shown and the displayed code is not multiline.
1598 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1600 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1601 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1603 // Do not underline the leading...
1604 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1605 // ...or trailing spaces. Account for substitutions containing unicode
1607 let sub_len: usize = part
1611 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1614 let offset: isize = offsets
1617 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1620 let underline_start = (span_start_pos + start) as isize + offset;
1621 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1622 assert!(underline_start >= 0 && underline_end >= 0);
1623 for p in underline_start..underline_end {
1626 ((max_line_num_len + 3) as isize + p) as usize,
1628 Style::UnderlinePrimary,
1631 // underline removals too
1632 if underline_start == underline_end {
1633 for p in underline_start - 1..underline_start + 1 {
1636 ((max_line_num_len + 3) as isize + p) as usize,
1638 Style::UnderlineSecondary,
1643 // length of the code after substitution
1644 let full_sub_len = part
1647 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1648 .sum::<usize>() as isize;
1650 // length of the code to be substituted
1651 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1652 // For multiple substitutions, use the position *after* the previous
1653 // substitutions have happened, only when further substitutions are
1654 // located strictly after.
1655 offsets.push((span_end_pos, full_sub_len - snippet_len));
1660 // if we elided some lines, add an ellipsis
1661 if lines.next().is_some() {
1662 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1663 } else if !show_underline {
1664 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1668 if suggestions.len() > MAX_SUGGESTIONS {
1669 let others = suggestions.len() - MAX_SUGGESTIONS;
1670 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1671 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1672 } else if notice_capitalization {
1673 let msg = "notice the capitalization difference";
1674 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1676 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1680 fn emit_messages_default(
1683 message: &[(String, Style)],
1684 code: &Option<DiagnosticId>,
1686 children: &[SubDiagnostic],
1687 suggestions: &[CodeSuggestion],
1689 let max_line_num_len = if self.ui_testing {
1690 ANONYMIZED_LINE_NUM.len()
1692 self.get_max_line_num(span, children).to_string().len()
1695 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1697 if !children.is_empty()
1698 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1700 let mut buffer = StyledBuffer::new();
1701 if !self.short_message {
1702 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1704 match emit_to_destination(
1711 Err(e) => panic!("failed to emit error: {}", e),
1714 if !self.short_message {
1715 for child in children {
1716 let span = child.render_span.as_ref().unwrap_or(&child.span);
1717 if let Err(err) = self.emit_message_default(
1719 &child.styled_message(),
1725 panic!("failed to emit error: {}", err);
1728 for sugg in suggestions {
1729 if sugg.style == SuggestionStyle::CompletelyHidden {
1730 // do not display this suggestion, it is meant only for tools
1731 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1732 if let Err(e) = self.emit_message_default(
1734 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1740 panic!("failed to emit error: {}", e);
1742 } else if let Err(e) =
1743 self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1745 panic!("failed to emit error: {}", e);
1750 Err(e) => panic!("failed to emit error: {}", e),
1753 let mut dst = self.dst.writable();
1754 match writeln!(dst) {
1755 Err(e) => panic!("failed to emit error: {}", e),
1757 if let Err(e) = dst.flush() {
1758 panic!("failed to emit error: {}", e)
1765 impl FileWithAnnotatedLines {
1766 /// Preprocess all the annotations so that they are grouped by file and by line number
1767 /// This helps us quickly iterate over the whole message (including secondary file spans)
1768 pub fn collect_annotations(
1770 source_map: &Option<Lrc<SourceMap>>,
1771 ) -> Vec<FileWithAnnotatedLines> {
1772 fn add_annotation_to_file(
1773 file_vec: &mut Vec<FileWithAnnotatedLines>,
1774 file: Lrc<SourceFile>,
1778 for slot in file_vec.iter_mut() {
1779 // Look through each of our files for the one we're adding to
1780 if slot.file.name == file.name {
1781 // See if we already have a line for it
1782 for line_slot in &mut slot.lines {
1783 if line_slot.line_index == line_index {
1784 line_slot.annotations.push(ann);
1788 // We don't have a line yet, create one
1789 slot.lines.push(Line { line_index, annotations: vec![ann] });
1794 // This is the first time we're seeing the file
1795 file_vec.push(FileWithAnnotatedLines {
1797 lines: vec![Line { line_index, annotations: vec![ann] }],
1802 let mut output = vec![];
1803 let mut multiline_annotations = vec![];
1805 if let Some(ref sm) = source_map {
1806 for span_label in msp.span_labels() {
1807 if span_label.span.is_dummy() {
1811 let lo = sm.lookup_char_pos(span_label.span.lo());
1812 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1814 // Watch out for "empty spans". If we get a span like 6..6, we
1815 // want to just display a `^` at 6, so convert that to
1816 // 6..7. This is degenerate input, but it's best to degrade
1817 // gracefully -- and the parser likes to supply a span like
1818 // that for EOF, in particular.
1820 if lo.col_display == hi.col_display && lo.line == hi.line {
1821 hi.col_display += 1;
1824 if lo.line != hi.line {
1825 let ml = MultilineAnnotation {
1827 line_start: lo.line,
1829 start_col: lo.col_display,
1830 end_col: hi.col_display,
1831 is_primary: span_label.is_primary,
1832 label: span_label.label,
1833 overlaps_exactly: false,
1835 multiline_annotations.push((lo.file, ml));
1837 let ann = Annotation {
1838 start_col: lo.col_display,
1839 end_col: hi.col_display,
1840 is_primary: span_label.is_primary,
1841 label: span_label.label,
1842 annotation_type: AnnotationType::Singleline,
1844 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1849 // Find overlapping multiline annotations, put them at different depths
1850 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1851 for (_, ann) in multiline_annotations.clone() {
1852 for (_, a) in multiline_annotations.iter_mut() {
1853 // Move all other multiline annotations overlapping with this one
1854 // one level to the right.
1855 if !(ann.same_span(a))
1856 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1859 } else if ann.same_span(a) && &ann != a {
1860 a.overlaps_exactly = true;
1867 let mut max_depth = 0; // max overlapping multiline spans
1868 for (file, ann) in multiline_annotations {
1869 max_depth = max(max_depth, ann.depth);
1870 let mut end_ann = ann.as_end();
1871 if !ann.overlaps_exactly {
1872 // avoid output like
1894 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1895 // 4 is the minimum vertical length of a multiline span when presented: two lines
1896 // of code and two lines of underline. This is not true for the special case where
1897 // the beginning doesn't have an underline, but the current logic seems to be
1898 // working correctly.
1899 let middle = min(ann.line_start + 4, ann.line_end);
1900 for line in ann.line_start + 1..middle {
1901 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1902 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1904 let line_end = ann.line_end - 1;
1905 if middle < line_end {
1906 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
1909 end_ann.annotation_type = AnnotationType::Singleline;
1911 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1913 for file_vec in output.iter_mut() {
1914 file_vec.multiline_depth = max_depth;
1920 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1921 buffer.puts(line, col, "| ", Style::LineNumber);
1924 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1925 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1928 fn draw_col_separator_no_space_with_style(
1929 buffer: &mut StyledBuffer,
1934 buffer.putc(line, col, '|', style);
1938 buffer: &mut StyledBuffer,
1945 for col in col_from..col_to {
1946 buffer.putc(line, col, symbol, style);
1950 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1951 buffer.puts(line, col, "= ", Style::LineNumber);
1954 fn draw_multiline_line(
1955 buffer: &mut StyledBuffer,
1961 buffer.putc(line, offset + depth - 1, '|', style);
1971 let extra = if inclusive { 1 } else { 0 };
1972 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
1974 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1975 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1978 fn emit_to_destination(
1979 rendered_buffer: &[Vec<StyledString>],
1981 dst: &mut Destination,
1982 short_message: bool,
1983 ) -> io::Result<()> {
1986 let mut dst = dst.writable();
1988 // In order to prevent error message interleaving, where multiple error lines get intermixed
1989 // when multiple compiler processes error simultaneously, we emit errors with additional
1992 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1993 // the .flush() is called we take the buffer created from the buffered writes and write it at
1994 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1995 // scheme, this buffered approach works and maintains the styling.
1997 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1998 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1999 // enough to output the full error message, then we release.
2000 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
2001 for (pos, line) in rendered_buffer.iter().enumerate() {
2003 dst.apply_style(*lvl, part.style)?;
2004 write!(dst, "{}", part.text)?;
2007 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2015 pub enum Destination {
2016 Terminal(StandardStream),
2017 Buffered(BufferWriter),
2018 // The bool denotes whether we should be emitting ansi color codes or not
2019 Raw(Box<(dyn Write + Send)>, bool),
2022 pub enum WritableDst<'a> {
2023 Terminal(&'a mut StandardStream),
2024 Buffered(&'a mut BufferWriter, Buffer),
2025 Raw(&'a mut (dyn Write + Send)),
2026 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2030 fn from_stderr(color: ColorConfig) -> Destination {
2031 let choice = color.to_color_choice();
2032 // On Windows we'll be performing global synchronization on the entire
2033 // system for emitting rustc errors, so there's no need to buffer
2036 // On non-Windows we rely on the atomicity of `write` to ensure errors
2037 // don't get all jumbled up.
2039 Terminal(StandardStream::stderr(choice))
2041 Buffered(BufferWriter::stderr(choice))
2045 fn writable(&mut self) -> WritableDst<'_> {
2047 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2048 Destination::Buffered(ref mut t) => {
2049 let buf = t.buffer();
2050 WritableDst::Buffered(t, buf)
2052 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2053 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2058 impl<'a> WritableDst<'a> {
2059 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2060 let mut spec = ColorSpec::new();
2062 Style::LineAndColumn => {}
2063 Style::LineNumber => {
2064 spec.set_bold(true);
2065 spec.set_intense(true);
2067 spec.set_fg(Some(Color::Cyan));
2069 spec.set_fg(Some(Color::Blue));
2072 Style::Quotation => {}
2073 Style::MainHeaderMsg => {
2074 spec.set_bold(true);
2076 spec.set_intense(true).set_fg(Some(Color::White));
2079 Style::UnderlinePrimary | Style::LabelPrimary => {
2081 spec.set_bold(true);
2083 Style::UnderlineSecondary | Style::LabelSecondary => {
2084 spec.set_bold(true).set_intense(true);
2086 spec.set_fg(Some(Color::Cyan));
2088 spec.set_fg(Some(Color::Blue));
2091 Style::HeaderMsg | Style::NoStyle => {}
2092 Style::Level(lvl) => {
2094 spec.set_bold(true);
2096 Style::Highlight => {
2097 spec.set_bold(true);
2100 self.set_color(&spec)
2103 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2105 WritableDst::Terminal(ref mut t) => t.set_color(color),
2106 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2107 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2108 WritableDst::Raw(_) => Ok(()),
2112 fn reset(&mut self) -> io::Result<()> {
2114 WritableDst::Terminal(ref mut t) => t.reset(),
2115 WritableDst::Buffered(_, ref mut t) => t.reset(),
2116 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2117 WritableDst::Raw(_) => Ok(()),
2122 impl<'a> Write for WritableDst<'a> {
2123 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2125 WritableDst::Terminal(ref mut t) => t.write(bytes),
2126 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2127 WritableDst::Raw(ref mut w) => w.write(bytes),
2128 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2132 fn flush(&mut self) -> io::Result<()> {
2134 WritableDst::Terminal(ref mut t) => t.flush(),
2135 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2136 WritableDst::Raw(ref mut w) => w.flush(),
2137 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2142 impl<'a> Drop for WritableDst<'a> {
2143 fn drop(&mut self) {
2144 if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
2145 drop(dst.print(buf));
2150 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2151 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2152 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2153 let found = match sm.span_to_snippet(sp) {
2154 Ok(snippet) => snippet,
2156 warn!("Invalid span {:?}. Err={:?}", sp, e);
2160 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2161 // All the chars that differ in capitalization are confusable (above):
2162 let confusable = found
2164 .zip(suggested.chars())
2165 .filter(|(f, s)| f != s)
2166 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2167 confusable && found.to_lowercase() == suggested.to_lowercase()
2168 // FIXME: We sometimes suggest the same thing we already have, which is a
2169 // bug, but be defensive against that here.
2170 && found != suggested