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_lint_defs::FutureBreakage;
13 use rustc_span::source_map::SourceMap;
14 use rustc_span::{MultiSpan, SourceFile, Span};
16 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
17 use crate::styled_buffer::StyledBuffer;
18 use crate::{CodeSuggestion, Diagnostic, DiagnosticId, Level, SubDiagnostic, SuggestionStyle};
20 use rustc_lint_defs::pluralize;
22 use rustc_data_structures::fx::FxHashMap;
23 use rustc_data_structures::sync::Lrc;
24 use rustc_span::hygiene::{ExpnKind, MacroKind};
26 use std::cmp::{max, min, Reverse};
28 use std::io::prelude::*;
31 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
32 use termcolor::{Buffer, Color, WriteColor};
35 /// Default column width, used in tests and when terminal dimensions cannot be determined.
36 const DEFAULT_COLUMN_WIDTH: usize = 140;
38 /// Describes the way the content of the `rendered` field of the json output is generated
39 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
40 pub enum HumanReadableErrorType {
42 AnnotateSnippet(ColorConfig),
46 impl HumanReadableErrorType {
47 /// Returns a (`short`, `color`) tuple
48 pub fn unzip(self) -> (bool, ColorConfig) {
50 HumanReadableErrorType::Default(cc) => (false, cc),
51 HumanReadableErrorType::Short(cc) => (true, cc),
52 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
57 dst: Box<dyn Write + Send>,
58 source_map: Option<Lrc<SourceMap>>,
60 terminal_width: Option<usize>,
61 macro_backtrace: bool,
63 let (short, color_config) = self.unzip();
64 let color = color_config.suggests_using_colors();
65 EmitterWriter::new(dst, source_map, short, teach, color, terminal_width, macro_backtrace)
69 #[derive(Clone, Copy, Debug)]
71 /// The available whitespace in the left that can be consumed when centering.
72 pub whitespace_left: usize,
73 /// The column of the beginning of left-most span.
75 /// The column of the end of right-most span.
76 pub span_right: usize,
77 /// The beginning of the line to be displayed.
78 pub computed_left: usize,
79 /// The end of the line to be displayed.
80 pub computed_right: usize,
81 /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default
83 pub column_width: usize,
84 /// The end column of a span label, including the span. Doesn't account for labels not in the
85 /// same line as the span.
86 pub label_right: usize,
91 whitespace_left: usize,
98 // The 6 is padding to give a bit of room for `...` when displaying:
103 // 16 | ... fn foo(self) -> Self::Bar {
108 whitespace_left: whitespace_left.saturating_sub(6),
109 span_left: span_left.saturating_sub(6),
110 span_right: span_right + 6,
114 label_right: label_right + 6,
116 m.compute(max_line_len);
120 fn was_cut_left(&self) -> bool {
121 self.computed_left > 0
124 fn was_cut_right(&self, line_len: usize) -> bool {
126 if self.computed_right == self.span_right || self.computed_right == self.label_right {
127 // Account for the "..." padding given above. Otherwise we end up with code lines that
128 // do fit but end in "..." as if they were trimmed.
129 self.computed_right - 6
133 right < line_len && self.computed_left + self.column_width < line_len
136 fn compute(&mut self, max_line_len: usize) {
137 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
138 self.computed_left = if self.whitespace_left > 20 {
139 self.whitespace_left - 16 // We want some padding.
143 // We want to show as much as possible, max_line_len is the right-most boundary for the
145 self.computed_right = max(max_line_len, self.computed_left);
147 if self.computed_right - self.computed_left > self.column_width {
148 // Trimming only whitespace isn't enough, let's get craftier.
149 if self.label_right - self.whitespace_left <= self.column_width {
150 // Attempt to fit the code window only trimming whitespace.
151 self.computed_left = self.whitespace_left;
152 self.computed_right = self.computed_left + self.column_width;
153 } else if self.label_right - self.span_left <= self.column_width {
154 // Attempt to fit the code window considering only the spans and labels.
155 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
156 self.computed_left = self.span_left.saturating_sub(padding_left);
157 self.computed_right = self.computed_left + self.column_width;
158 } else if self.span_right - self.span_left <= self.column_width {
159 // Attempt to fit the code window considering the spans and labels plus padding.
160 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
161 self.computed_left = self.span_left.saturating_sub(padding_left);
162 self.computed_right = self.computed_left + self.column_width;
164 // Mostly give up but still don't show the full line.
165 self.computed_left = self.span_left;
166 self.computed_right = self.span_right;
171 fn left(&self, line_len: usize) -> usize {
172 min(self.computed_left, line_len)
175 fn right(&self, line_len: usize) -> usize {
176 if line_len.saturating_sub(self.computed_left) <= self.column_width {
179 min(line_len, self.computed_right)
184 const ANONYMIZED_LINE_NUM: &str = "LL";
186 /// Emitter trait for emitting errors.
188 /// Emit a structured diagnostic.
189 fn emit_diagnostic(&mut self, diag: &Diagnostic);
191 /// Emit a notification that an artifact has been output.
192 /// This is currently only supported for the JSON format,
193 /// other formats can, and will, simply ignore it.
194 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
196 fn emit_future_breakage_report(&mut self, _diags: Vec<(FutureBreakage, Diagnostic)>) {}
198 /// Emit list of unused externs
199 fn emit_unused_externs(&mut self, _lint_level: &str, _unused_externs: &[&str]) {}
201 /// Checks if should show explanations about "rustc --explain"
202 fn should_show_explain(&self) -> bool {
206 /// Checks if we can use colors in the current output stream.
207 fn supports_color(&self) -> bool {
211 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
213 /// Formats the substitutions of the primary_span
215 /// The are a lot of conditions to this method, but in short:
217 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
218 /// we format the `help` suggestion depending on the content of the
219 /// substitutions. In that case, we return the modified span only.
221 /// * If the current `Diagnostic` has multiple suggestions,
222 /// we return the original `primary_span` and the original suggestions.
223 fn primary_span_formatted<'a>(
225 diag: &'a Diagnostic,
226 ) -> (MultiSpan, &'a [CodeSuggestion]) {
227 let mut primary_span = diag.span.clone();
228 if let Some((sugg, rest)) = diag.suggestions.split_first() {
229 if rest.is_empty() &&
230 // ^ if there is only one suggestion
231 // don't display multi-suggestions as labels
232 sugg.substitutions.len() == 1 &&
233 // don't display multipart suggestions as labels
234 sugg.substitutions[0].parts.len() == 1 &&
235 // don't display long messages as labels
236 sugg.msg.split_whitespace().count() < 10 &&
237 // don't display multiline suggestions as labels
238 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
240 // when this style is set we want the suggestion to be a message, not inline
241 SuggestionStyle::HideCodeAlways,
242 // trivial suggestion for tooling's sake, never shown
243 SuggestionStyle::CompletelyHidden,
244 // subtle suggestion, never shown inline
245 SuggestionStyle::ShowAlways,
246 ].contains(&sugg.style)
248 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
249 let msg = if substitution.is_empty() || sugg.style.hide_inline() {
250 // This substitution is only removal OR we explicitly don't want to show the
251 // code inline (`hide_inline`). Therefore, we don't show the substitution.
252 format!("help: {}", sugg.msg)
254 // Show the default suggestion text with the substitution
260 .map(|sm| is_case_difference(
263 sugg.substitutions[0].parts[0].span,
267 " (notice the capitalization)"
274 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
276 // We return only the modified primary_span
279 // if there are multiple suggestions, print them all in full
280 // to be consistent. We could try to figure out if we can
281 // make one (or the first one) inline, but that would give
282 // undue importance to a semi-random suggestion
283 (primary_span, &diag.suggestions)
286 (primary_span, &diag.suggestions)
290 fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
292 source_map: &Option<Lrc<SourceMap>>,
293 span: &mut MultiSpan,
294 children: &mut Vec<SubDiagnostic>,
298 // Check for spans in macros, before `fix_multispans_in_extern_macros`
299 // has a chance to replace them.
300 let has_macro_spans = iter::once(&*span)
301 .chain(children.iter().map(|child| &child.span))
302 .flat_map(|span| span.primary_spans())
303 .flat_map(|sp| sp.macro_backtrace())
304 .find_map(|expn_data| {
305 match expn_data.kind {
306 ExpnKind::Root => None,
308 // Skip past non-macro entries, just in case there
309 // are some which do actually involve macros.
310 ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
312 ExpnKind::Macro { kind: macro_kind, name, proc_macro: _ } => {
313 Some((macro_kind, name))
319 self.fix_multispans_in_extern_macros(source_map, span, children);
322 self.render_multispans_macro_backtrace(span, children, backtrace);
325 if let Some((macro_kind, name)) = has_macro_spans {
326 let descr = macro_kind.descr();
329 "this {level} originates in the {descr} `{name}` \
330 (in Nightly builds, run with -Z macro-backtrace for more info)",
333 children.push(SubDiagnostic {
335 message: vec![(msg, Style::NoStyle)],
336 span: MultiSpan::new(),
343 fn render_multispans_macro_backtrace(
345 span: &mut MultiSpan,
346 children: &mut Vec<SubDiagnostic>,
349 for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
350 self.render_multispan_macro_backtrace(span, backtrace);
354 fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
355 let mut new_labels: Vec<(Span, String)> = vec![];
357 for &sp in span.primary_spans() {
362 // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
363 // entries we don't want to print, to make sure the indices being
364 // printed are contiguous (or omitted if there's only one entry).
365 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
366 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
367 if trace.def_site.is_dummy() {
371 if matches!(trace.kind, ExpnKind::Inlined) {
373 .push((trace.call_site, "in the inlined copy of this code".to_string()));
374 } else if always_backtrace {
375 let proc_macro = if let ExpnKind::Macro { kind: _, name: _, proc_macro: true } =
386 "in this expansion of {}`{}`{}",
389 if macro_backtrace.len() > 1 {
390 // if macro_backtrace.len() == 1 it'll be
391 // pointed at by "in this macro invocation"
392 format!(" (#{})", i + 1)
400 // Don't add a label on the call site if the diagnostic itself
401 // already points to (a part of) that call site, as the label
402 // is meant for showing the relevant invocation when the actual
403 // diagnostic is pointing to some part of macro definition.
405 // This also handles the case where an external span got replaced
406 // with the call site span by `fix_multispans_in_extern_macros`.
408 // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
409 // "in this expansion of" label above is always added in that mode,
410 // and it needs an "in this macro invocation" label to match that.
411 let redundant_span = trace.call_site.contains(sp);
416 ExpnKind::Macro { kind: MacroKind::Bang, name: _, proc_macro: _ }
423 "in this macro invocation{}",
424 if macro_backtrace.len() > 1 && always_backtrace {
425 // only specify order when the macro
426 // backtrace is multiple levels deep
427 format!(" (#{})", i + 1)
434 if !always_backtrace {
440 for (label_span, label_text) in new_labels {
441 span.push_span_label(label_span, label_text);
445 // This does a small "fix" for multispans by looking to see if it can find any that
446 // point directly at external macros. Since these are often difficult to read,
447 // this will change the span to point at the use site.
448 fn fix_multispans_in_extern_macros(
450 source_map: &Option<Lrc<SourceMap>>,
451 span: &mut MultiSpan,
452 children: &mut Vec<SubDiagnostic>,
454 let source_map = if let Some(ref sm) = source_map {
459 debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
460 self.fix_multispan_in_extern_macros(source_map, span);
461 for child in children.iter_mut() {
462 self.fix_multispan_in_extern_macros(source_map, &mut child.span);
464 debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
467 // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
468 // Since these locations are often difficult to read,
469 // we move these spans from the external macros to their corresponding use site.
470 fn fix_multispan_in_extern_macros(&self, source_map: &Lrc<SourceMap>, span: &mut MultiSpan) {
471 // First, find all the spans in external macros and point instead at their use site.
472 let replacements: Vec<(Span, Span)> = span
476 .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
478 if !sp.is_dummy() && source_map.is_imported(sp) {
479 let maybe_callsite = sp.source_callsite();
480 if sp != maybe_callsite {
481 return Some((sp, maybe_callsite));
488 // After we have them, make sure we replace these 'bad' def sites with their use sites.
489 for (from, to) in replacements {
490 span.replace(from, to);
495 impl Emitter for EmitterWriter {
496 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
500 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
501 let mut children = diag.children.clone();
502 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
503 debug!("emit_diagnostic: suggestions={:?}", suggestions);
505 self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
510 self.macro_backtrace,
513 self.emit_messages_default(
515 &diag.styled_message(),
523 fn should_show_explain(&self) -> bool {
527 fn supports_color(&self) -> bool {
528 self.dst.supports_color()
532 /// An emitter that does nothing when emitting a diagnostic.
533 pub struct SilentEmitter;
535 impl Emitter for SilentEmitter {
536 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
539 fn emit_diagnostic(&mut self, _: &Diagnostic) {}
542 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
544 /// This should be replaced with a more involved mechanism to output multiline suggestions that
545 /// more closely mimics the regular diagnostic output, where irrelevant code lines are elided.
546 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
547 /// Maximum number of suggestions to be shown
549 /// Arbitrary, but taken from trait import suggestion limit
550 pub const MAX_SUGGESTIONS: usize = 4;
552 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
553 pub enum ColorConfig {
560 fn to_color_choice(self) -> ColorChoice {
562 ColorConfig::Always => {
563 if atty::is(atty::Stream::Stderr) {
566 ColorChoice::AlwaysAnsi
569 ColorConfig::Never => ColorChoice::Never,
570 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
571 ColorConfig::Auto => ColorChoice::Never,
574 fn suggests_using_colors(self) -> bool {
576 ColorConfig::Always | ColorConfig::Auto => true,
577 ColorConfig::Never => false,
582 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
583 pub struct EmitterWriter {
585 sm: Option<Lrc<SourceMap>>,
589 terminal_width: Option<usize>,
591 macro_backtrace: bool,
595 pub struct FileWithAnnotatedLines {
596 pub file: Lrc<SourceFile>,
597 pub lines: Vec<Line>,
598 multiline_depth: usize,
603 color_config: ColorConfig,
604 source_map: Option<Lrc<SourceMap>>,
607 terminal_width: Option<usize>,
608 macro_backtrace: bool,
610 let dst = Destination::from_stderr(color_config);
623 dst: Box<dyn Write + Send>,
624 source_map: Option<Lrc<SourceMap>>,
628 terminal_width: Option<usize>,
629 macro_backtrace: bool,
632 dst: Raw(dst, colored),
642 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
643 self.ui_testing = ui_testing;
647 fn maybe_anonymized(&self, line_num: usize) -> String {
648 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
653 buffer: &mut StyledBuffer,
661 // Tabs are assumed to have been replaced by spaces in calling code.
662 debug_assert!(!source_string.contains('\t'));
663 let line_len = source_string.len();
664 // Create the source line we will highlight.
665 let left = margin.left(line_len);
666 let right = margin.right(line_len);
667 // On long lines, we strip the source line, accounting for unicode.
669 let code: String = source_string
673 // Make sure that the trimming on the right will fall within the terminal width.
674 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
675 // For now, just accept that sometimes the code line will be longer than desired.
676 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
677 if taken + next > right - left {
684 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
685 if margin.was_cut_left() {
686 // We have stripped some code/whitespace from the beginning, make it clear.
687 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
689 if margin.was_cut_right(line_len) {
690 // We have stripped some code after the right-most span end, make it clear we did so.
691 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
693 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
695 draw_col_separator(buffer, line_offset, width_offset - 2);
698 fn render_source_line(
700 buffer: &mut StyledBuffer,
701 file: Lrc<SourceFile>,
706 ) -> Vec<(usize, Style)> {
712 // | secondary span label
714 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
716 // | | | actual code found in your source code and the spans we use to mark it
717 // | | when there's too much wasted space to the left, trim it
718 // | vertical divider between the column number and the code
721 if line.line_index == 0 {
725 let source_string = match file.get_line(line.line_index - 1) {
726 Some(s) => replace_tabs(&*s),
727 None => return Vec::new(),
730 let line_offset = buffer.num_lines();
732 let left = margin.left(source_string.len()); // Left trim
733 // Account for unicode characters of width !=0 that were removed.
734 let left = source_string
737 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
750 // Special case when there's only one annotation involved, it is the start of a multiline
751 // span and there's no text at the beginning of the code line. Instead of doing the whole
760 // we simplify the output to:
766 if let [ann] = &line.annotations[..] {
767 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
768 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
769 let style = if ann.is_primary {
770 Style::UnderlinePrimary
772 Style::UnderlineSecondary
774 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
775 return vec![(depth, style)];
780 // We want to display like this:
782 // vec.push(vec.pop().unwrap());
783 // --- ^^^ - previous borrow ends here
785 // | error occurs here
786 // previous borrow of `vec` occurs here
788 // But there are some weird edge cases to be aware of:
790 // vec.push(vec.pop().unwrap());
791 // -------- - previous borrow ends here
793 // |this makes no sense
794 // previous borrow of `vec` occurs here
796 // For this reason, we group the lines into "highlight lines"
797 // and "annotations lines", where the highlight lines have the `^`.
799 // Sort the annotations by (start, end col)
800 // The labels are reversed, sort and then reversed again.
801 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
802 // the letter signifies the span. Here we are only sorting by the
803 // span and hence, the order of the elements with the same span will
804 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
805 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
806 // still ordered first to last, but all the elements with different
807 // spans are ordered by their spans in last to first order. Last to
808 // first order is important, because the jiggly lines and | are on
809 // the left, so the rightmost span needs to be rendered first,
810 // otherwise the lines would end up needing to go over a message.
812 let mut annotations = line.annotations.clone();
813 annotations.sort_by_key(|a| Reverse(a.start_col));
815 // First, figure out where each label will be positioned.
817 // In the case where you have the following annotations:
819 // vec.push(vec.pop().unwrap());
820 // -------- - previous borrow ends here [C]
822 // |this makes no sense [B]
823 // previous borrow of `vec` occurs here [A]
825 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
827 // We try, when possible, to stick the rightmost annotation at the end
828 // of the highlight line:
830 // vec.push(vec.pop().unwrap());
831 // --- --- - previous borrow ends here
833 // But sometimes that's not possible because one of the other
834 // annotations overlaps it. For example, from the test
835 // `span_overlap_label`, we have the following annotations
836 // (written on distinct lines for clarity):
842 // In this case, we can't stick the rightmost-most label on
843 // the highlight line, or we would get:
850 // which is totally weird. Instead we want:
858 // which is...less weird, at least. In fact, in general, if
859 // the rightmost span overlaps with any other span, we should
860 // use the "hang below" version, so we can at least make it
861 // clear where the span *starts*. There's an exception for this
862 // logic, when the labels do not have a message:
877 let mut annotations_position = vec![];
878 let mut line_len = 0;
880 for (i, annotation) in annotations.iter().enumerate() {
881 for (j, next) in annotations.iter().enumerate() {
882 if overlaps(next, annotation, 0) // This label overlaps with another one and both
883 && annotation.has_label() // take space (they have text and are not
884 && j > i // multiline lines).
886 // We're currently on the first line, move the label one line down
888 // If we're overlapping with an un-labelled annotation with the same span
889 // we can just merge them in the output
890 if next.start_col == annotation.start_col
891 && next.end_col == annotation.end_col
897 // This annotation needs a new line in the output.
902 annotations_position.push((p, annotation));
903 for (j, next) in annotations.iter().enumerate() {
905 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
906 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
907 // line if they overlap including padding, to
908 // avoid situations like:
915 && annotation.has_label() // Both labels must have some text, otherwise
916 && next.has_label()) // they are not overlapping.
917 // Do not add a new line if this annotation
918 // or the next are vertical line placeholders.
919 || (annotation.takes_space() // If either this or the next annotation is
920 && next.has_label()) // multiline start/end, move it to a new line
921 || (annotation.has_label() // so as not to overlap the horizontal lines.
922 && next.takes_space())
923 || (annotation.takes_space() && next.takes_space())
924 || (overlaps(next, annotation, l)
925 && next.end_col <= annotation.end_col
930 // This annotation needs a new line in the output.
936 line_len = max(line_len, p);
943 // If there are no annotations or the only annotations on this line are
944 // MultilineLine, then there's only code being shown, stop processing.
945 if line.annotations.iter().all(|a| a.is_line()) {
949 // Write the column separator.
951 // After this we will have:
960 for pos in 0..=line_len {
961 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
962 buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber);
965 // Write the horizontal lines for multiline annotations
966 // (only the first and last lines need this).
968 // After this we will have:
977 for &(pos, annotation) in &annotations_position {
978 let style = if annotation.is_primary {
979 Style::UnderlinePrimary
981 Style::UnderlineSecondary
984 match annotation.annotation_type {
985 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
990 width_offset + depth,
991 (code_offset + annotation.start_col).saturating_sub(left),
996 buffer.set_style_range(
998 (code_offset + annotation.start_col).saturating_sub(left),
999 (code_offset + annotation.end_col).saturating_sub(left),
1001 annotation.is_primary,
1008 // Write the vertical lines for labels that are on a different line as the underline.
1010 // After this we will have:
1019 for &(pos, annotation) in &annotations_position {
1020 let style = if annotation.is_primary {
1021 Style::UnderlinePrimary
1023 Style::UnderlineSecondary
1027 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
1028 for p in line_offset + 1..=line_offset + pos {
1031 (code_offset + annotation.start_col).saturating_sub(left),
1037 match annotation.annotation_type {
1038 AnnotationType::MultilineStart(depth) => {
1039 for p in line_offset + pos + 1..line_offset + line_len + 2 {
1040 buffer.putc(p, width_offset + depth - 1, '|', style);
1043 AnnotationType::MultilineEnd(depth) => {
1044 for p in line_offset..=line_offset + pos {
1045 buffer.putc(p, width_offset + depth - 1, '|', style);
1052 // Write the labels on the annotations that actually have a label.
1054 // After this we will have:
1059 // | something about `foo`
1063 for &(pos, annotation) in &annotations_position {
1065 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1066 let (pos, col) = if pos == 0 {
1067 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1069 (pos + 2, annotation.start_col.saturating_sub(left))
1071 if let Some(ref label) = annotation.label {
1072 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1076 // Sort from biggest span to smallest span so that smaller spans are
1077 // represented in the output:
1082 // | | something about `foo`
1083 // | something about `fn foo()`
1084 annotations_position.sort_by_key(|(_, ann)| {
1085 // Decreasing order. When annotations share the same length, prefer `Primary`.
1086 (Reverse(ann.len()), ann.is_primary)
1089 // Write the underlines.
1091 // After this we will have:
1096 // | something about `foo`
1100 for &(_, annotation) in &annotations_position {
1101 let (underline, style) = if annotation.is_primary {
1102 ('^', Style::UnderlinePrimary)
1104 ('-', Style::UnderlineSecondary)
1106 for p in annotation.start_col..annotation.end_col {
1109 (code_offset + p).saturating_sub(left),
1115 annotations_position
1117 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1118 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1119 let style = if annotation.is_primary {
1122 Style::LabelSecondary
1128 .collect::<Vec<_>>()
1131 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1132 let sm = match self.sm {
1138 for primary_span in msp.primary_spans() {
1139 if !primary_span.is_dummy() {
1140 let hi = sm.lookup_char_pos(primary_span.hi());
1141 max = (hi.line).max(max);
1144 if !self.short_message {
1145 for span_label in msp.span_labels() {
1146 if !span_label.span.is_dummy() {
1147 let hi = sm.lookup_char_pos(span_label.span.hi());
1148 max = (hi.line).max(max);
1156 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1157 let primary = self.get_multispan_max_line_num(span);
1160 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1166 /// Adds a left margin to every line but the first, given a padding length and the label being
1167 /// displayed, keeping the provided highlighting.
1170 buffer: &mut StyledBuffer,
1171 msg: &[(String, Style)],
1174 override_style: Option<Style>,
1176 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1179 // --> file.rs:13:20
1184 // = note: multiline
1189 // | | length of label
1191 // `max_line_num_len`
1192 let padding = " ".repeat(padding + label.len() + 5);
1194 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1195 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1196 match (style, override_) {
1197 (Style::NoStyle, Some(override_)) => override_,
1202 let mut line_number = 0;
1204 // Provided the following diagnostic message:
1208 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1209 // ("looks", Style::Highlight),
1210 // ("with\nvery ", Style::NoStyle),
1211 // ("weird", Style::Highlight),
1212 // (" formats\n", Style::NoStyle),
1213 // ("see?", Style::Highlight),
1216 // the expected output on a note is (* surround the highlighted text)
1218 // = note: highlighted multiline
1220 // see how it *looks* with
1221 // very *weird* formats
1223 for &(ref text, ref style) in msg.iter() {
1224 let lines = text.split('\n').collect::<Vec<_>>();
1225 if lines.len() > 1 {
1226 for (i, line) in lines.iter().enumerate() {
1229 buffer.append(line_number, &padding, Style::NoStyle);
1231 buffer.append(line_number, line, style_or_override(*style, override_style));
1234 buffer.append(line_number, text, style_or_override(*style, override_style));
1239 fn emit_message_default(
1242 msg: &[(String, Style)],
1243 code: &Option<DiagnosticId>,
1245 max_line_num_len: usize,
1247 ) -> io::Result<()> {
1248 let mut buffer = StyledBuffer::new();
1250 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1252 // This is a secondary message with no span info
1253 for _ in 0..max_line_num_len {
1254 buffer.prepend(0, " ", Style::NoStyle);
1256 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1257 if *level != Level::FailureNote {
1258 buffer.append(0, level.to_str(), Style::MainHeaderMsg);
1259 buffer.append(0, ": ", Style::NoStyle);
1261 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1263 // The failure note level itself does not provide any useful diagnostic information
1264 if *level != Level::FailureNote {
1265 buffer.append(0, level.to_str(), Style::Level(*level));
1267 // only render error codes, not lint codes
1268 if let Some(DiagnosticId::Error(ref code)) = *code {
1269 buffer.append(0, "[", Style::Level(*level));
1270 buffer.append(0, &code, Style::Level(*level));
1271 buffer.append(0, "]", Style::Level(*level));
1273 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1274 if *level != Level::FailureNote {
1275 buffer.append(0, ": ", header_style);
1277 for &(ref text, _) in msg.iter() {
1278 buffer.append(0, &replace_tabs(text), header_style);
1282 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1284 // Make sure our primary file comes first
1285 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1286 (self.sm.as_ref(), msp.primary_span().as_ref())
1288 if !primary_span.is_dummy() {
1289 (sm.lookup_char_pos(primary_span.lo()), sm)
1291 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1295 // If we don't have span information, emit and exit
1296 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1300 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1302 annotated_files.swap(0, pos);
1305 // Print out the annotate source lines that correspond with the error
1306 for annotated_file in annotated_files {
1307 // we can't annotate anything if the source is unavailable.
1308 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1312 // print out the span location and spacer before we print the annotated source
1313 // to do this, we need to know if this span will be primary
1314 let is_primary = primary_lo.file.name == annotated_file.file.name;
1316 let loc = primary_lo.clone();
1317 if !self.short_message {
1318 // remember where we are in the output buffer for easy reference
1319 let buffer_msg_line_offset = buffer.num_lines();
1321 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1323 buffer_msg_line_offset,
1326 loc.file.name.prefer_local(),
1327 sm.doctest_offset_line(&loc.file.name, loc.line),
1330 Style::LineAndColumn,
1332 for _ in 0..max_line_num_len {
1333 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1340 loc.file.name.prefer_local(),
1341 sm.doctest_offset_line(&loc.file.name, loc.line),
1344 Style::LineAndColumn,
1347 } else if !self.short_message {
1348 // remember where we are in the output buffer for easy reference
1349 let buffer_msg_line_offset = buffer.num_lines();
1352 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1354 // Then, the secondary file indicator
1355 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1356 let loc = if let Some(first_line) = annotated_file.lines.first() {
1357 let col = if let Some(first_annotation) = first_line.annotations.first() {
1358 format!(":{}", first_annotation.start_col + 1)
1364 annotated_file.file.name.prefer_local(),
1365 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1369 format!("{}", annotated_file.file.name.prefer_local())
1371 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1372 for _ in 0..max_line_num_len {
1373 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1377 if !self.short_message {
1378 // Put in the spacer between the location and annotated source
1379 let buffer_msg_line_offset = buffer.num_lines();
1380 draw_col_separator_no_space(
1382 buffer_msg_line_offset,
1383 max_line_num_len + 1,
1386 // Contains the vertical lines' positions for active multiline annotations
1387 let mut multilines = FxHashMap::default();
1389 // Get the left-side margin to remove it
1390 let mut whitespace_margin = usize::MAX;
1391 for line_idx in 0..annotated_file.lines.len() {
1392 let file = annotated_file.file.clone();
1393 let line = &annotated_file.lines[line_idx];
1394 if let Some(source_string) = file.get_line(line.line_index - 1) {
1395 let leading_whitespace = source_string
1397 .take_while(|c| c.is_whitespace())
1400 // Tabs are displayed as 4 spaces
1406 if source_string.chars().any(|c| !c.is_whitespace()) {
1407 whitespace_margin = min(whitespace_margin, leading_whitespace);
1411 if whitespace_margin == usize::MAX {
1412 whitespace_margin = 0;
1415 // Left-most column any visible span points at.
1416 let mut span_left_margin = usize::MAX;
1417 for line in &annotated_file.lines {
1418 for ann in &line.annotations {
1419 span_left_margin = min(span_left_margin, ann.start_col);
1420 span_left_margin = min(span_left_margin, ann.end_col);
1423 if span_left_margin == usize::MAX {
1424 span_left_margin = 0;
1427 // Right-most column any visible span points at.
1428 let mut span_right_margin = 0;
1429 let mut label_right_margin = 0;
1430 let mut max_line_len = 0;
1431 for line in &annotated_file.lines {
1434 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1436 for ann in &line.annotations {
1437 span_right_margin = max(span_right_margin, ann.start_col);
1438 span_right_margin = max(span_right_margin, ann.end_col);
1439 // FIXME: account for labels not in the same line
1440 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1441 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1445 let width_offset = 3 + max_line_num_len;
1446 let code_offset = if annotated_file.multiline_depth == 0 {
1449 width_offset + annotated_file.multiline_depth + 1
1452 let column_width = if let Some(width) = self.terminal_width {
1453 width.saturating_sub(code_offset)
1454 } else if self.ui_testing {
1455 DEFAULT_COLUMN_WIDTH
1457 termize::dimensions()
1458 .map(|(w, _)| w.saturating_sub(code_offset))
1459 .unwrap_or(DEFAULT_COLUMN_WIDTH)
1462 let margin = Margin::new(
1471 // Next, output the annotate source for this file
1472 for line_idx in 0..annotated_file.lines.len() {
1473 let previous_buffer_line = buffer.num_lines();
1475 let depths = self.render_source_line(
1477 annotated_file.file.clone(),
1478 &annotated_file.lines[line_idx],
1484 let mut to_add = FxHashMap::default();
1486 for (depth, style) in depths {
1487 if multilines.remove(&depth).is_none() {
1488 to_add.insert(depth, style);
1492 // Set the multiline annotation vertical lines to the left of
1493 // the code in this line.
1494 for (depth, style) in &multilines {
1495 for line in previous_buffer_line..buffer.num_lines() {
1496 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1499 // check to see if we need to print out or elide lines that come between
1500 // this annotated line and the next one.
1501 if line_idx < (annotated_file.lines.len() - 1) {
1502 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1503 - annotated_file.lines[line_idx].line_index;
1504 if line_idx_delta > 2 {
1505 let last_buffer_line_num = buffer.num_lines();
1506 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1508 // Set the multiline annotation vertical lines on `...` bridging line.
1509 for (depth, style) in &multilines {
1510 draw_multiline_line(
1512 last_buffer_line_num,
1518 } else if line_idx_delta == 2 {
1519 let unannotated_line = annotated_file
1521 .get_line(annotated_file.lines[line_idx].line_index)
1522 .unwrap_or_else(|| Cow::from(""));
1524 let last_buffer_line_num = buffer.num_lines();
1528 &replace_tabs(&unannotated_line),
1529 annotated_file.lines[line_idx + 1].line_index - 1,
1530 last_buffer_line_num,
1536 for (depth, style) in &multilines {
1537 draw_multiline_line(
1539 last_buffer_line_num,
1548 multilines.extend(&to_add);
1553 // final step: take our styled buffer, render it, then output it
1554 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1559 fn emit_suggestion_default(
1561 suggestion: &CodeSuggestion,
1563 max_line_num_len: usize,
1564 ) -> io::Result<()> {
1565 let sm = match self.sm {
1567 None => return Ok(()),
1570 // Render the replacements for each suggestion
1571 let suggestions = suggestion.splice_lines(&**sm);
1572 debug!("emit_suggestion_default: suggestions={:?}", suggestions);
1574 if suggestions.is_empty() {
1575 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1576 // approach to avoid ICEs by ignoring the suggestion outright.
1580 let mut buffer = StyledBuffer::new();
1582 // Render the suggestion message
1583 buffer.append(0, level.to_str(), Style::Level(*level));
1584 buffer.append(0, ": ", Style::HeaderMsg);
1588 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1591 Some(Style::HeaderMsg),
1594 let mut row_num = 2;
1595 let mut notice_capitalization = false;
1596 for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
1597 notice_capitalization |= only_capitalization;
1598 // Only show underline if the suggestion spans a single line and doesn't cover the
1599 // entirety of the code output. If you have multiple replacements in the same line
1600 // of code, show the underline.
1601 let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
1602 && complete.lines().count() == 1;
1605 .span_to_lines(parts[0].span)
1606 .expect("span_to_lines failed when emitting suggestion");
1608 assert!(!lines.lines.is_empty() || parts[0].span.is_dummy());
1610 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1611 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1612 let mut lines = complete.lines();
1613 for (line_pos, line) in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES).enumerate()
1615 // Print the span column to avoid confusion
1619 &self.maybe_anonymized(line_start + line_pos),
1622 // print the suggestion
1623 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1624 buffer.append(row_num, &replace_tabs(line), Style::NoStyle);
1628 // This offset and the ones below need to be signed to account for replacement code
1629 // that is shorter than the original code.
1630 let mut offsets: Vec<(usize, isize)> = Vec::new();
1631 // Only show an underline in the suggestions if the suggestion is not the
1632 // entirety of the code being shown and the displayed code is not multiline.
1634 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1636 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1637 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1639 // Do not underline the leading...
1640 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1641 // ...or trailing spaces. Account for substitutions containing unicode
1643 let sub_len: usize = part
1647 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1650 let offset: isize = offsets
1653 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1656 let underline_start = (span_start_pos + start) as isize + offset;
1657 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1658 assert!(underline_start >= 0 && underline_end >= 0);
1659 for p in underline_start..underline_end {
1662 ((max_line_num_len + 3) as isize + p) as usize,
1664 Style::UnderlinePrimary,
1667 // underline removals too
1668 if underline_start == underline_end {
1669 for p in underline_start - 1..underline_start + 1 {
1672 ((max_line_num_len + 3) as isize + p) as usize,
1674 Style::UnderlineSecondary,
1679 // length of the code after substitution
1680 let full_sub_len = part
1683 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1684 .sum::<usize>() as isize;
1686 // length of the code to be substituted
1687 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1688 // For multiple substitutions, use the position *after* the previous
1689 // substitutions have happened, only when further substitutions are
1690 // located strictly after.
1691 offsets.push((span_end_pos, full_sub_len - snippet_len));
1696 // if we elided some lines, add an ellipsis
1697 if lines.next().is_some() {
1698 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1699 } else if !show_underline {
1700 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1704 if suggestions.len() > MAX_SUGGESTIONS {
1705 let others = suggestions.len() - MAX_SUGGESTIONS;
1706 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1707 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1708 } else if notice_capitalization {
1709 let msg = "notice the capitalization difference";
1710 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1712 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1716 fn emit_messages_default(
1719 message: &[(String, Style)],
1720 code: &Option<DiagnosticId>,
1722 children: &[SubDiagnostic],
1723 suggestions: &[CodeSuggestion],
1725 let max_line_num_len = if self.ui_testing {
1726 ANONYMIZED_LINE_NUM.len()
1728 let n = self.get_max_line_num(span, children);
1729 num_decimal_digits(n)
1732 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1734 if !children.is_empty()
1735 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1737 let mut buffer = StyledBuffer::new();
1738 if !self.short_message {
1739 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1741 if let Err(e) = emit_to_destination(
1747 panic!("failed to emit error: {}", e)
1750 if !self.short_message {
1751 for child in children {
1752 let span = child.render_span.as_ref().unwrap_or(&child.span);
1753 if let Err(err) = self.emit_message_default(
1755 &child.styled_message(),
1761 panic!("failed to emit error: {}", err);
1764 for sugg in suggestions {
1765 if sugg.style == SuggestionStyle::CompletelyHidden {
1766 // do not display this suggestion, it is meant only for tools
1767 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1768 if let Err(e) = self.emit_message_default(
1770 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1776 panic!("failed to emit error: {}", e);
1778 } else if let Err(e) =
1779 self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1781 panic!("failed to emit error: {}", e);
1786 Err(e) => panic!("failed to emit error: {}", e),
1789 let mut dst = self.dst.writable();
1790 match writeln!(dst) {
1791 Err(e) => panic!("failed to emit error: {}", e),
1793 if let Err(e) = dst.flush() {
1794 panic!("failed to emit error: {}", e)
1801 impl FileWithAnnotatedLines {
1802 /// Preprocess all the annotations so that they are grouped by file and by line number
1803 /// This helps us quickly iterate over the whole message (including secondary file spans)
1804 pub fn collect_annotations(
1806 source_map: &Option<Lrc<SourceMap>>,
1807 ) -> Vec<FileWithAnnotatedLines> {
1808 fn add_annotation_to_file(
1809 file_vec: &mut Vec<FileWithAnnotatedLines>,
1810 file: Lrc<SourceFile>,
1814 for slot in file_vec.iter_mut() {
1815 // Look through each of our files for the one we're adding to
1816 if slot.file.name == file.name {
1817 // See if we already have a line for it
1818 for line_slot in &mut slot.lines {
1819 if line_slot.line_index == line_index {
1820 line_slot.annotations.push(ann);
1824 // We don't have a line yet, create one
1825 slot.lines.push(Line { line_index, annotations: vec![ann] });
1830 // This is the first time we're seeing the file
1831 file_vec.push(FileWithAnnotatedLines {
1833 lines: vec![Line { line_index, annotations: vec![ann] }],
1838 let mut output = vec![];
1839 let mut multiline_annotations = vec![];
1841 if let Some(ref sm) = source_map {
1842 for span_label in msp.span_labels() {
1843 if span_label.span.is_dummy() {
1847 let lo = sm.lookup_char_pos(span_label.span.lo());
1848 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1850 // Watch out for "empty spans". If we get a span like 6..6, we
1851 // want to just display a `^` at 6, so convert that to
1852 // 6..7. This is degenerate input, but it's best to degrade
1853 // gracefully -- and the parser likes to supply a span like
1854 // that for EOF, in particular.
1856 if lo.col_display == hi.col_display && lo.line == hi.line {
1857 hi.col_display += 1;
1860 if lo.line != hi.line {
1861 let ml = MultilineAnnotation {
1863 line_start: lo.line,
1865 start_col: lo.col_display,
1866 end_col: hi.col_display,
1867 is_primary: span_label.is_primary,
1868 label: span_label.label,
1869 overlaps_exactly: false,
1871 multiline_annotations.push((lo.file, ml));
1873 let ann = Annotation {
1874 start_col: lo.col_display,
1875 end_col: hi.col_display,
1876 is_primary: span_label.is_primary,
1877 label: span_label.label,
1878 annotation_type: AnnotationType::Singleline,
1880 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1885 // Find overlapping multiline annotations, put them at different depths
1886 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1887 for (_, ann) in multiline_annotations.clone() {
1888 for (_, a) in multiline_annotations.iter_mut() {
1889 // Move all other multiline annotations overlapping with this one
1890 // one level to the right.
1891 if !(ann.same_span(a))
1892 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1895 } else if ann.same_span(a) && &ann != a {
1896 a.overlaps_exactly = true;
1903 let mut max_depth = 0; // max overlapping multiline spans
1904 for (file, ann) in multiline_annotations {
1905 max_depth = max(max_depth, ann.depth);
1906 let mut end_ann = ann.as_end();
1907 if !ann.overlaps_exactly {
1908 // avoid output like
1930 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1931 // 4 is the minimum vertical length of a multiline span when presented: two lines
1932 // of code and two lines of underline. This is not true for the special case where
1933 // the beginning doesn't have an underline, but the current logic seems to be
1934 // working correctly.
1935 let middle = min(ann.line_start + 4, ann.line_end);
1936 for line in ann.line_start + 1..middle {
1937 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1938 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1940 let line_end = ann.line_end - 1;
1941 if middle < line_end {
1942 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
1945 end_ann.annotation_type = AnnotationType::Singleline;
1947 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1949 for file_vec in output.iter_mut() {
1950 file_vec.multiline_depth = max_depth;
1956 // instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
1957 // we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
1958 // is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
1959 // This is also why we need the max number of decimal digits within a `usize`.
1960 fn num_decimal_digits(num: usize) -> usize {
1961 #[cfg(target_pointer_width = "64")]
1962 const MAX_DIGITS: usize = 20;
1964 #[cfg(target_pointer_width = "32")]
1965 const MAX_DIGITS: usize = 10;
1967 #[cfg(target_pointer_width = "16")]
1968 const MAX_DIGITS: usize = 5;
1971 for num_digits in 1..MAX_DIGITS {
1975 lim = lim.wrapping_mul(10);
1980 fn replace_tabs(str: &str) -> String {
1981 str.replace('\t', " ")
1984 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1985 buffer.puts(line, col, "| ", Style::LineNumber);
1988 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1989 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1992 fn draw_col_separator_no_space_with_style(
1993 buffer: &mut StyledBuffer,
1998 buffer.putc(line, col, '|', style);
2002 buffer: &mut StyledBuffer,
2009 for col in col_from..col_to {
2010 buffer.putc(line, col, symbol, style);
2014 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2015 buffer.puts(line, col, "= ", Style::LineNumber);
2018 fn draw_multiline_line(
2019 buffer: &mut StyledBuffer,
2025 buffer.putc(line, offset + depth - 1, '|', style);
2035 let extra = if inclusive { 1 } else { 0 };
2036 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
2038 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
2039 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
2042 fn emit_to_destination(
2043 rendered_buffer: &[Vec<StyledString>],
2045 dst: &mut Destination,
2046 short_message: bool,
2047 ) -> io::Result<()> {
2050 let mut dst = dst.writable();
2052 // In order to prevent error message interleaving, where multiple error lines get intermixed
2053 // when multiple compiler processes error simultaneously, we emit errors with additional
2056 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
2057 // the .flush() is called we take the buffer created from the buffered writes and write it at
2058 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
2059 // scheme, this buffered approach works and maintains the styling.
2061 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
2062 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
2063 // enough to output the full error message, then we release.
2064 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
2065 for (pos, line) in rendered_buffer.iter().enumerate() {
2067 dst.apply_style(*lvl, part.style)?;
2068 write!(dst, "{}", part.text)?;
2071 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2079 pub enum Destination {
2080 Terminal(StandardStream),
2081 Buffered(BufferWriter),
2082 // The bool denotes whether we should be emitting ansi color codes or not
2083 Raw(Box<(dyn Write + Send)>, bool),
2086 pub enum WritableDst<'a> {
2087 Terminal(&'a mut StandardStream),
2088 Buffered(&'a mut BufferWriter, Buffer),
2089 Raw(&'a mut (dyn Write + Send)),
2090 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2094 fn from_stderr(color: ColorConfig) -> Destination {
2095 let choice = color.to_color_choice();
2096 // On Windows we'll be performing global synchronization on the entire
2097 // system for emitting rustc errors, so there's no need to buffer
2100 // On non-Windows we rely on the atomicity of `write` to ensure errors
2101 // don't get all jumbled up.
2103 Terminal(StandardStream::stderr(choice))
2105 Buffered(BufferWriter::stderr(choice))
2109 fn writable(&mut self) -> WritableDst<'_> {
2111 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2112 Destination::Buffered(ref mut t) => {
2113 let buf = t.buffer();
2114 WritableDst::Buffered(t, buf)
2116 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2117 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2121 fn supports_color(&self) -> bool {
2123 Self::Terminal(ref stream) => stream.supports_color(),
2124 Self::Buffered(ref buffer) => buffer.buffer().supports_color(),
2125 Self::Raw(_, supports_color) => supports_color,
2130 impl<'a> WritableDst<'a> {
2131 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2132 let mut spec = ColorSpec::new();
2134 Style::LineAndColumn => {}
2135 Style::LineNumber => {
2136 spec.set_bold(true);
2137 spec.set_intense(true);
2139 spec.set_fg(Some(Color::Cyan));
2141 spec.set_fg(Some(Color::Blue));
2144 Style::Quotation => {}
2145 Style::MainHeaderMsg => {
2146 spec.set_bold(true);
2148 spec.set_intense(true).set_fg(Some(Color::White));
2151 Style::UnderlinePrimary | Style::LabelPrimary => {
2153 spec.set_bold(true);
2155 Style::UnderlineSecondary | Style::LabelSecondary => {
2156 spec.set_bold(true).set_intense(true);
2158 spec.set_fg(Some(Color::Cyan));
2160 spec.set_fg(Some(Color::Blue));
2163 Style::HeaderMsg | Style::NoStyle => {}
2164 Style::Level(lvl) => {
2166 spec.set_bold(true);
2168 Style::Highlight => {
2169 spec.set_bold(true);
2172 self.set_color(&spec)
2175 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2177 WritableDst::Terminal(ref mut t) => t.set_color(color),
2178 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2179 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2180 WritableDst::Raw(_) => Ok(()),
2184 fn reset(&mut self) -> io::Result<()> {
2186 WritableDst::Terminal(ref mut t) => t.reset(),
2187 WritableDst::Buffered(_, ref mut t) => t.reset(),
2188 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2189 WritableDst::Raw(_) => Ok(()),
2194 impl<'a> Write for WritableDst<'a> {
2195 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2197 WritableDst::Terminal(ref mut t) => t.write(bytes),
2198 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2199 WritableDst::Raw(ref mut w) => w.write(bytes),
2200 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2204 fn flush(&mut self) -> io::Result<()> {
2206 WritableDst::Terminal(ref mut t) => t.flush(),
2207 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2208 WritableDst::Raw(ref mut w) => w.flush(),
2209 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2214 impl<'a> Drop for WritableDst<'a> {
2215 fn drop(&mut self) {
2216 if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
2217 drop(dst.print(buf));
2222 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2223 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2224 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2225 let found = match sm.span_to_snippet(sp) {
2226 Ok(snippet) => snippet,
2228 warn!("Invalid span {:?}. Err={:?}", sp, e);
2232 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2233 // All the chars that differ in capitalization are confusable (above):
2234 let confusable = iter::zip(found.chars(), suggested.chars())
2235 .filter(|(f, s)| f != s)
2236 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2237 confusable && found.to_lowercase() == suggested.to_lowercase()
2238 // FIXME: We sometimes suggest the same thing we already have, which is a
2239 // bug, but be defensive against that here.
2240 && found != suggested