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;
17 use crate::{CodeSuggestion, Diagnostic, DiagnosticId, Level, SubDiagnostic, SuggestionStyle};
19 use rustc_lint_defs::pluralize;
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 fn emit_future_breakage_report(&mut self, _diags: Vec<Diagnostic>) {}
197 /// Emit list of unused externs
198 fn emit_unused_externs(&mut self, _lint_level: &str, _unused_externs: &[&str]) {}
200 /// Checks if should show explanations about "rustc --explain"
201 fn should_show_explain(&self) -> bool {
205 /// Checks if we can use colors in the current output stream.
206 fn supports_color(&self) -> bool {
210 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
212 /// Formats the substitutions of the primary_span
214 /// The are a lot of conditions to this method, but in short:
216 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
217 /// we format the `help` suggestion depending on the content of the
218 /// substitutions. In that case, we return the modified span only.
220 /// * If the current `Diagnostic` has multiple suggestions,
221 /// we return the original `primary_span` and the original suggestions.
222 fn primary_span_formatted<'a>(
224 diag: &'a Diagnostic,
225 ) -> (MultiSpan, &'a [CodeSuggestion]) {
226 let mut primary_span = diag.span.clone();
227 if let Some((sugg, rest)) = diag.suggestions.split_first() {
228 if rest.is_empty() &&
229 // ^ if there is only one suggestion
230 // don't display multi-suggestions as labels
231 sugg.substitutions.len() == 1 &&
232 // don't display multipart suggestions as labels
233 sugg.substitutions[0].parts.len() == 1 &&
234 // don't display long messages as labels
235 sugg.msg.split_whitespace().count() < 10 &&
236 // don't display multiline suggestions as labels
237 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
239 // when this style is set we want the suggestion to be a message, not inline
240 SuggestionStyle::HideCodeAlways,
241 // trivial suggestion for tooling's sake, never shown
242 SuggestionStyle::CompletelyHidden,
243 // subtle suggestion, never shown inline
244 SuggestionStyle::ShowAlways,
245 ].contains(&sugg.style)
247 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
248 let msg = if substitution.is_empty() || sugg.style.hide_inline() {
249 // This substitution is only removal OR we explicitly don't want to show the
250 // code inline (`hide_inline`). Therefore, we don't show the substitution.
251 format!("help: {}", sugg.msg)
253 // Show the default suggestion text with the substitution
259 .map(|sm| is_case_difference(
262 sugg.substitutions[0].parts[0].span,
266 " (notice the capitalization)"
273 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
275 // We return only the modified primary_span
278 // if there are multiple suggestions, print them all in full
279 // to be consistent. We could try to figure out if we can
280 // make one (or the first one) inline, but that would give
281 // undue importance to a semi-random suggestion
282 (primary_span, &diag.suggestions)
285 (primary_span, &diag.suggestions)
289 fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
291 source_map: &Option<Lrc<SourceMap>>,
292 span: &mut MultiSpan,
293 children: &mut Vec<SubDiagnostic>,
297 // Check for spans in macros, before `fix_multispans_in_extern_macros`
298 // has a chance to replace them.
299 let has_macro_spans = iter::once(&*span)
300 .chain(children.iter().map(|child| &child.span))
301 .flat_map(|span| span.primary_spans())
302 .flat_map(|sp| sp.macro_backtrace())
303 .find_map(|expn_data| {
304 match expn_data.kind {
305 ExpnKind::Root => None,
307 // Skip past non-macro entries, just in case there
308 // are some which do actually involve macros.
309 ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
311 ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)),
316 self.fix_multispans_in_extern_macros(source_map, span, children);
319 self.render_multispans_macro_backtrace(span, children, backtrace);
322 if let Some((macro_kind, name)) = has_macro_spans {
323 let descr = macro_kind.descr();
326 "this {level} originates in the {descr} `{name}` \
327 (in Nightly builds, run with -Z macro-backtrace for more info)",
330 children.push(SubDiagnostic {
332 message: vec![(msg, Style::NoStyle)],
333 span: MultiSpan::new(),
340 fn render_multispans_macro_backtrace(
342 span: &mut MultiSpan,
343 children: &mut Vec<SubDiagnostic>,
346 for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
347 self.render_multispan_macro_backtrace(span, backtrace);
351 fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
352 let mut new_labels: Vec<(Span, String)> = vec![];
354 for &sp in span.primary_spans() {
359 // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
360 // entries we don't want to print, to make sure the indices being
361 // printed are contiguous (or omitted if there's only one entry).
362 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
363 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
364 if trace.def_site.is_dummy() {
368 if always_backtrace && !matches!(trace.kind, ExpnKind::Inlined) {
372 "in this expansion of `{}`{}",
374 if macro_backtrace.len() > 1 {
375 // if macro_backtrace.len() == 1 it'll be
376 // pointed at by "in this macro invocation"
377 format!(" (#{})", i + 1)
385 // Don't add a label on the call site if the diagnostic itself
386 // already points to (a part of) that call site, as the label
387 // is meant for showing the relevant invocation when the actual
388 // diagnostic is pointing to some part of macro definition.
390 // This also handles the case where an external span got replaced
391 // with the call site span by `fix_multispans_in_extern_macros`.
393 // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
394 // "in this expansion of" label above is always added in that mode,
395 // and it needs an "in this macro invocation" label to match that.
396 let redundant_span = trace.call_site.contains(sp);
398 if !redundant_span || always_backtrace {
399 let msg: Cow<'static, _> = match trace.kind {
400 ExpnKind::Macro(MacroKind::Attr, _) => {
401 "this procedural macro expansion".into()
403 ExpnKind::Macro(MacroKind::Derive, _) => {
404 "this derive macro expansion".into()
406 ExpnKind::Macro(MacroKind::Bang, _) => "this macro invocation".into(),
407 ExpnKind::Inlined => "the inlined copy of this code".into(),
408 ExpnKind::Root => "in the crate root".into(),
409 ExpnKind::AstPass(kind) => kind.descr().into(),
410 ExpnKind::Desugaring(kind) => {
411 format!("this {} desugaring", kind.descr()).into()
419 if macro_backtrace.len() > 1 && always_backtrace {
420 // only specify order when the macro
421 // backtrace is multiple levels deep
422 format!(" (#{})", i + 1)
429 if !always_backtrace {
435 for (label_span, label_text) in new_labels {
436 span.push_span_label(label_span, label_text);
440 // This does a small "fix" for multispans by looking to see if it can find any that
441 // point directly at external macros. Since these are often difficult to read,
442 // this will change the span to point at the use site.
443 fn fix_multispans_in_extern_macros(
445 source_map: &Option<Lrc<SourceMap>>,
446 span: &mut MultiSpan,
447 children: &mut Vec<SubDiagnostic>,
449 let source_map = if let Some(ref sm) = source_map {
454 debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
455 self.fix_multispan_in_extern_macros(source_map, span);
456 for child in children.iter_mut() {
457 self.fix_multispan_in_extern_macros(source_map, &mut child.span);
459 debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children);
462 // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros.
463 // Since these locations are often difficult to read,
464 // we move these spans from the external macros to their corresponding use site.
465 fn fix_multispan_in_extern_macros(&self, source_map: &Lrc<SourceMap>, span: &mut MultiSpan) {
466 // First, find all the spans in external macros and point instead at their use site.
467 let replacements: Vec<(Span, Span)> = span
471 .chain(span.span_labels().iter().map(|sp_label| sp_label.span))
473 if !sp.is_dummy() && source_map.is_imported(sp) {
474 let maybe_callsite = sp.source_callsite();
475 if sp != maybe_callsite {
476 return Some((sp, maybe_callsite));
483 // After we have them, make sure we replace these 'bad' def sites with their use sites.
484 for (from, to) in replacements {
485 span.replace(from, to);
490 impl Emitter for EmitterWriter {
491 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
495 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
496 let mut children = diag.children.clone();
497 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
498 debug!("emit_diagnostic: suggestions={:?}", suggestions);
500 self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
505 self.macro_backtrace,
508 self.emit_messages_default(
510 &diag.styled_message(),
518 fn should_show_explain(&self) -> bool {
522 fn supports_color(&self) -> bool {
523 self.dst.supports_color()
527 /// An emitter that does nothing when emitting a diagnostic.
528 pub struct SilentEmitter;
530 impl Emitter for SilentEmitter {
531 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
534 fn emit_diagnostic(&mut self, _: &Diagnostic) {}
537 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
539 /// This should be replaced with a more involved mechanism to output multiline suggestions that
540 /// more closely mimics the regular diagnostic output, where irrelevant code lines are elided.
541 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
542 /// Maximum number of suggestions to be shown
544 /// Arbitrary, but taken from trait import suggestion limit
545 pub const MAX_SUGGESTIONS: usize = 4;
547 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
548 pub enum ColorConfig {
555 fn to_color_choice(self) -> ColorChoice {
557 ColorConfig::Always => {
558 if atty::is(atty::Stream::Stderr) {
561 ColorChoice::AlwaysAnsi
564 ColorConfig::Never => ColorChoice::Never,
565 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
566 ColorConfig::Auto => ColorChoice::Never,
569 fn suggests_using_colors(self) -> bool {
571 ColorConfig::Always | ColorConfig::Auto => true,
572 ColorConfig::Never => false,
577 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
578 pub struct EmitterWriter {
580 sm: Option<Lrc<SourceMap>>,
584 terminal_width: Option<usize>,
586 macro_backtrace: bool,
590 pub struct FileWithAnnotatedLines {
591 pub file: Lrc<SourceFile>,
592 pub lines: Vec<Line>,
593 multiline_depth: usize,
598 color_config: ColorConfig,
599 source_map: Option<Lrc<SourceMap>>,
602 terminal_width: Option<usize>,
603 macro_backtrace: bool,
605 let dst = Destination::from_stderr(color_config);
618 dst: Box<dyn Write + Send>,
619 source_map: Option<Lrc<SourceMap>>,
623 terminal_width: Option<usize>,
624 macro_backtrace: bool,
627 dst: Raw(dst, colored),
637 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
638 self.ui_testing = ui_testing;
642 fn maybe_anonymized(&self, line_num: usize) -> String {
643 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
648 buffer: &mut StyledBuffer,
656 // Tabs are assumed to have been replaced by spaces in calling code.
657 debug_assert!(!source_string.contains('\t'));
658 let line_len = source_string.len();
659 // Create the source line we will highlight.
660 let left = margin.left(line_len);
661 let right = margin.right(line_len);
662 // On long lines, we strip the source line, accounting for unicode.
664 let code: String = source_string
668 // Make sure that the trimming on the right will fall within the terminal width.
669 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
670 // For now, just accept that sometimes the code line will be longer than desired.
671 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
672 if taken + next > right - left {
679 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
680 if margin.was_cut_left() {
681 // We have stripped some code/whitespace from the beginning, make it clear.
682 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
684 if margin.was_cut_right(line_len) {
685 // We have stripped some code after the right-most span end, make it clear we did so.
686 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
688 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
690 draw_col_separator(buffer, line_offset, width_offset - 2);
693 fn render_source_line(
695 buffer: &mut StyledBuffer,
696 file: Lrc<SourceFile>,
701 ) -> Vec<(usize, Style)> {
707 // | secondary span label
709 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
711 // | | | actual code found in your source code and the spans we use to mark it
712 // | | when there's too much wasted space to the left, trim it
713 // | vertical divider between the column number and the code
716 if line.line_index == 0 {
720 let source_string = match file.get_line(line.line_index - 1) {
721 Some(s) => replace_tabs(&*s),
722 None => return Vec::new(),
725 let line_offset = buffer.num_lines();
727 let left = margin.left(source_string.len()); // Left trim
728 // Account for unicode characters of width !=0 that were removed.
729 let left = source_string
732 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
745 // Special case when there's only one annotation involved, it is the start of a multiline
746 // span and there's no text at the beginning of the code line. Instead of doing the whole
755 // we simplify the output to:
761 if let [ann] = &line.annotations[..] {
762 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
763 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
764 let style = if ann.is_primary {
765 Style::UnderlinePrimary
767 Style::UnderlineSecondary
769 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
770 return vec![(depth, style)];
775 // We want to display like this:
777 // vec.push(vec.pop().unwrap());
778 // --- ^^^ - previous borrow ends here
780 // | error occurs here
781 // previous borrow of `vec` occurs here
783 // But there are some weird edge cases to be aware of:
785 // vec.push(vec.pop().unwrap());
786 // -------- - previous borrow ends here
788 // |this makes no sense
789 // previous borrow of `vec` occurs here
791 // For this reason, we group the lines into "highlight lines"
792 // and "annotations lines", where the highlight lines have the `^`.
794 // Sort the annotations by (start, end col)
795 // The labels are reversed, sort and then reversed again.
796 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
797 // the letter signifies the span. Here we are only sorting by the
798 // span and hence, the order of the elements with the same span will
799 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
800 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
801 // still ordered first to last, but all the elements with different
802 // spans are ordered by their spans in last to first order. Last to
803 // first order is important, because the jiggly lines and | are on
804 // the left, so the rightmost span needs to be rendered first,
805 // otherwise the lines would end up needing to go over a message.
807 let mut annotations = line.annotations.clone();
808 annotations.sort_by_key(|a| Reverse(a.start_col));
810 // First, figure out where each label will be positioned.
812 // In the case where you have the following annotations:
814 // vec.push(vec.pop().unwrap());
815 // -------- - previous borrow ends here [C]
817 // |this makes no sense [B]
818 // previous borrow of `vec` occurs here [A]
820 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
822 // We try, when possible, to stick the rightmost annotation at the end
823 // of the highlight line:
825 // vec.push(vec.pop().unwrap());
826 // --- --- - previous borrow ends here
828 // But sometimes that's not possible because one of the other
829 // annotations overlaps it. For example, from the test
830 // `span_overlap_label`, we have the following annotations
831 // (written on distinct lines for clarity):
837 // In this case, we can't stick the rightmost-most label on
838 // the highlight line, or we would get:
845 // which is totally weird. Instead we want:
853 // which is...less weird, at least. In fact, in general, if
854 // the rightmost span overlaps with any other span, we should
855 // use the "hang below" version, so we can at least make it
856 // clear where the span *starts*. There's an exception for this
857 // logic, when the labels do not have a message:
872 let mut annotations_position = vec![];
873 let mut line_len = 0;
875 for (i, annotation) in annotations.iter().enumerate() {
876 for (j, next) in annotations.iter().enumerate() {
877 if overlaps(next, annotation, 0) // This label overlaps with another one and both
878 && annotation.has_label() // take space (they have text and are not
879 && j > i // multiline lines).
881 // We're currently on the first line, move the label one line down
883 // If we're overlapping with an un-labelled annotation with the same span
884 // we can just merge them in the output
885 if next.start_col == annotation.start_col
886 && next.end_col == annotation.end_col
892 // This annotation needs a new line in the output.
897 annotations_position.push((p, annotation));
898 for (j, next) in annotations.iter().enumerate() {
900 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
901 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
902 // line if they overlap including padding, to
903 // avoid situations like:
910 && annotation.has_label() // Both labels must have some text, otherwise
911 && next.has_label()) // they are not overlapping.
912 // Do not add a new line if this annotation
913 // or the next are vertical line placeholders.
914 || (annotation.takes_space() // If either this or the next annotation is
915 && next.has_label()) // multiline start/end, move it to a new line
916 || (annotation.has_label() // so as not to overlap the horizontal lines.
917 && next.takes_space())
918 || (annotation.takes_space() && next.takes_space())
919 || (overlaps(next, annotation, l)
920 && next.end_col <= annotation.end_col
925 // This annotation needs a new line in the output.
931 line_len = max(line_len, p);
938 // If there are no annotations or the only annotations on this line are
939 // MultilineLine, then there's only code being shown, stop processing.
940 if line.annotations.iter().all(|a| a.is_line()) {
944 // Write the column separator.
946 // After this we will have:
955 for pos in 0..=line_len {
956 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
959 // Write the horizontal lines for multiline annotations
960 // (only the first and last lines need this).
962 // After this we will have:
971 for &(pos, annotation) in &annotations_position {
972 let style = if annotation.is_primary {
973 Style::UnderlinePrimary
975 Style::UnderlineSecondary
978 match annotation.annotation_type {
979 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
984 width_offset + depth,
985 (code_offset + annotation.start_col).saturating_sub(left),
990 buffer.set_style_range(
992 (code_offset + annotation.start_col).saturating_sub(left),
993 (code_offset + annotation.end_col).saturating_sub(left),
995 annotation.is_primary,
1002 // Write the vertical lines for labels that are on a different line as the underline.
1004 // After this we will have:
1013 for &(pos, annotation) in &annotations_position {
1014 let style = if annotation.is_primary {
1015 Style::UnderlinePrimary
1017 Style::UnderlineSecondary
1021 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
1022 for p in line_offset + 1..=line_offset + pos {
1025 (code_offset + annotation.start_col).saturating_sub(left),
1031 match annotation.annotation_type {
1032 AnnotationType::MultilineStart(depth) => {
1033 for p in line_offset + pos + 1..line_offset + line_len + 2 {
1034 buffer.putc(p, width_offset + depth - 1, '|', style);
1037 AnnotationType::MultilineEnd(depth) => {
1038 for p in line_offset..=line_offset + pos {
1039 buffer.putc(p, width_offset + depth - 1, '|', style);
1046 // Write the labels on the annotations that actually have a label.
1048 // After this we will have:
1053 // | something about `foo`
1057 for &(pos, annotation) in &annotations_position {
1059 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1060 let (pos, col) = if pos == 0 {
1061 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1063 (pos + 2, annotation.start_col.saturating_sub(left))
1065 if let Some(ref label) = annotation.label {
1066 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1070 // Sort from biggest span to smallest span so that smaller spans are
1071 // represented in the output:
1076 // | | something about `foo`
1077 // | something about `fn foo()`
1078 annotations_position.sort_by_key(|(_, ann)| {
1079 // Decreasing order. When annotations share the same length, prefer `Primary`.
1080 (Reverse(ann.len()), ann.is_primary)
1083 // Write the underlines.
1085 // After this we will have:
1090 // | something about `foo`
1094 for &(_, annotation) in &annotations_position {
1095 let (underline, style) = if annotation.is_primary {
1096 ('^', Style::UnderlinePrimary)
1098 ('-', Style::UnderlineSecondary)
1100 for p in annotation.start_col..annotation.end_col {
1103 (code_offset + p).saturating_sub(left),
1109 annotations_position
1111 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1112 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1113 let style = if annotation.is_primary {
1116 Style::LabelSecondary
1122 .collect::<Vec<_>>()
1125 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1126 let sm = match self.sm {
1132 for primary_span in msp.primary_spans() {
1133 if !primary_span.is_dummy() {
1134 let hi = sm.lookup_char_pos(primary_span.hi());
1135 max = (hi.line).max(max);
1138 if !self.short_message {
1139 for span_label in msp.span_labels() {
1140 if !span_label.span.is_dummy() {
1141 let hi = sm.lookup_char_pos(span_label.span.hi());
1142 max = (hi.line).max(max);
1150 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1151 let primary = self.get_multispan_max_line_num(span);
1154 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1160 /// Adds a left margin to every line but the first, given a padding length and the label being
1161 /// displayed, keeping the provided highlighting.
1164 buffer: &mut StyledBuffer,
1165 msg: &[(String, Style)],
1168 override_style: Option<Style>,
1170 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1173 // --> file.rs:13:20
1178 // = note: multiline
1183 // | | length of label
1185 // `max_line_num_len`
1186 let padding = " ".repeat(padding + label.len() + 5);
1188 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1189 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1190 match (style, override_) {
1191 (Style::NoStyle, Some(override_)) => override_,
1196 let mut line_number = 0;
1198 // Provided the following diagnostic message:
1202 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1203 // ("looks", Style::Highlight),
1204 // ("with\nvery ", Style::NoStyle),
1205 // ("weird", Style::Highlight),
1206 // (" formats\n", Style::NoStyle),
1207 // ("see?", Style::Highlight),
1210 // the expected output on a note is (* surround the highlighted text)
1212 // = note: highlighted multiline
1214 // see how it *looks* with
1215 // very *weird* formats
1217 for &(ref text, ref style) in msg.iter() {
1218 let lines = text.split('\n').collect::<Vec<_>>();
1219 if lines.len() > 1 {
1220 for (i, line) in lines.iter().enumerate() {
1223 buffer.append(line_number, &padding, Style::NoStyle);
1225 buffer.append(line_number, line, style_or_override(*style, override_style));
1228 buffer.append(line_number, text, style_or_override(*style, override_style));
1233 fn emit_message_default(
1236 msg: &[(String, Style)],
1237 code: &Option<DiagnosticId>,
1239 max_line_num_len: usize,
1241 ) -> io::Result<()> {
1242 let mut buffer = StyledBuffer::new();
1244 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1246 // This is a secondary message with no span info
1247 for _ in 0..max_line_num_len {
1248 buffer.prepend(0, " ", Style::NoStyle);
1250 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1251 if *level != Level::FailureNote {
1252 buffer.append(0, level.to_str(), Style::MainHeaderMsg);
1253 buffer.append(0, ": ", Style::NoStyle);
1255 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1257 // The failure note level itself does not provide any useful diagnostic information
1258 if *level != Level::FailureNote {
1259 buffer.append(0, level.to_str(), Style::Level(*level));
1261 // only render error codes, not lint codes
1262 if let Some(DiagnosticId::Error(ref code)) = *code {
1263 buffer.append(0, "[", Style::Level(*level));
1264 buffer.append(0, &code, Style::Level(*level));
1265 buffer.append(0, "]", Style::Level(*level));
1267 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1268 if *level != Level::FailureNote {
1269 buffer.append(0, ": ", header_style);
1271 for &(ref text, _) in msg.iter() {
1272 buffer.append(0, &replace_tabs(text), header_style);
1276 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1278 // Make sure our primary file comes first
1279 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1280 (self.sm.as_ref(), msp.primary_span().as_ref())
1282 if !primary_span.is_dummy() {
1283 (sm.lookup_char_pos(primary_span.lo()), sm)
1285 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1289 // If we don't have span information, emit and exit
1290 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1294 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1296 annotated_files.swap(0, pos);
1299 // Print out the annotate source lines that correspond with the error
1300 for annotated_file in annotated_files {
1301 // we can't annotate anything if the source is unavailable.
1302 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1306 // print out the span location and spacer before we print the annotated source
1307 // to do this, we need to know if this span will be primary
1308 let is_primary = primary_lo.file.name == annotated_file.file.name;
1310 let loc = primary_lo.clone();
1311 if !self.short_message {
1312 // remember where we are in the output buffer for easy reference
1313 let buffer_msg_line_offset = buffer.num_lines();
1315 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1317 buffer_msg_line_offset,
1320 loc.file.name.prefer_local(),
1321 sm.doctest_offset_line(&loc.file.name, loc.line),
1324 Style::LineAndColumn,
1326 for _ in 0..max_line_num_len {
1327 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1334 loc.file.name.prefer_local(),
1335 sm.doctest_offset_line(&loc.file.name, loc.line),
1338 Style::LineAndColumn,
1341 } else if !self.short_message {
1342 // remember where we are in the output buffer for easy reference
1343 let buffer_msg_line_offset = buffer.num_lines();
1346 draw_col_separator_no_space(
1348 buffer_msg_line_offset,
1349 max_line_num_len + 1,
1352 // Then, the secondary file indicator
1353 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1354 let loc = if let Some(first_line) = annotated_file.lines.first() {
1355 let col = if let Some(first_annotation) = first_line.annotations.first() {
1356 format!(":{}", first_annotation.start_col + 1)
1362 annotated_file.file.name.prefer_local(),
1363 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1367 format!("{}", annotated_file.file.name.prefer_local())
1369 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1370 for _ in 0..max_line_num_len {
1371 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1375 if !self.short_message {
1376 // Put in the spacer between the location and annotated source
1377 let buffer_msg_line_offset = buffer.num_lines();
1378 draw_col_separator_no_space(
1380 buffer_msg_line_offset,
1381 max_line_num_len + 1,
1384 // Contains the vertical lines' positions for active multiline annotations
1385 let mut multilines = FxHashMap::default();
1387 // Get the left-side margin to remove it
1388 let mut whitespace_margin = usize::MAX;
1389 for line_idx in 0..annotated_file.lines.len() {
1390 let file = annotated_file.file.clone();
1391 let line = &annotated_file.lines[line_idx];
1392 if let Some(source_string) = file.get_line(line.line_index - 1) {
1393 let leading_whitespace = source_string
1395 .take_while(|c| c.is_whitespace())
1398 // Tabs are displayed as 4 spaces
1404 if source_string.chars().any(|c| !c.is_whitespace()) {
1405 whitespace_margin = min(whitespace_margin, leading_whitespace);
1409 if whitespace_margin == usize::MAX {
1410 whitespace_margin = 0;
1413 // Left-most column any visible span points at.
1414 let mut span_left_margin = usize::MAX;
1415 for line in &annotated_file.lines {
1416 for ann in &line.annotations {
1417 span_left_margin = min(span_left_margin, ann.start_col);
1418 span_left_margin = min(span_left_margin, ann.end_col);
1421 if span_left_margin == usize::MAX {
1422 span_left_margin = 0;
1425 // Right-most column any visible span points at.
1426 let mut span_right_margin = 0;
1427 let mut label_right_margin = 0;
1428 let mut max_line_len = 0;
1429 for line in &annotated_file.lines {
1432 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1434 for ann in &line.annotations {
1435 span_right_margin = max(span_right_margin, ann.start_col);
1436 span_right_margin = max(span_right_margin, ann.end_col);
1437 // FIXME: account for labels not in the same line
1438 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1439 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1443 let width_offset = 3 + max_line_num_len;
1444 let code_offset = if annotated_file.multiline_depth == 0 {
1447 width_offset + annotated_file.multiline_depth + 1
1450 let column_width = if let Some(width) = self.terminal_width {
1451 width.saturating_sub(code_offset)
1452 } else if self.ui_testing {
1453 DEFAULT_COLUMN_WIDTH
1455 termize::dimensions()
1456 .map(|(w, _)| w.saturating_sub(code_offset))
1457 .unwrap_or(DEFAULT_COLUMN_WIDTH)
1460 let margin = Margin::new(
1469 // Next, output the annotate source for this file
1470 for line_idx in 0..annotated_file.lines.len() {
1471 let previous_buffer_line = buffer.num_lines();
1473 let depths = self.render_source_line(
1475 annotated_file.file.clone(),
1476 &annotated_file.lines[line_idx],
1482 let mut to_add = FxHashMap::default();
1484 for (depth, style) in depths {
1485 if multilines.remove(&depth).is_none() {
1486 to_add.insert(depth, style);
1490 // Set the multiline annotation vertical lines to the left of
1491 // the code in this line.
1492 for (depth, style) in &multilines {
1493 for line in previous_buffer_line..buffer.num_lines() {
1494 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1497 // check to see if we need to print out or elide lines that come between
1498 // this annotated line and the next one.
1499 if line_idx < (annotated_file.lines.len() - 1) {
1500 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1501 - annotated_file.lines[line_idx].line_index;
1502 if line_idx_delta > 2 {
1503 let last_buffer_line_num = buffer.num_lines();
1504 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1506 // Set the multiline annotation vertical lines on `...` bridging line.
1507 for (depth, style) in &multilines {
1508 draw_multiline_line(
1510 last_buffer_line_num,
1516 } else if line_idx_delta == 2 {
1517 let unannotated_line = annotated_file
1519 .get_line(annotated_file.lines[line_idx].line_index)
1520 .unwrap_or_else(|| Cow::from(""));
1522 let last_buffer_line_num = buffer.num_lines();
1526 &replace_tabs(&unannotated_line),
1527 annotated_file.lines[line_idx + 1].line_index - 1,
1528 last_buffer_line_num,
1534 for (depth, style) in &multilines {
1535 draw_multiline_line(
1537 last_buffer_line_num,
1546 multilines.extend(&to_add);
1551 // final step: take our styled buffer, render it, then output it
1552 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1557 fn emit_suggestion_default(
1559 suggestion: &CodeSuggestion,
1561 max_line_num_len: usize,
1562 ) -> io::Result<()> {
1563 let sm = match self.sm {
1565 None => return Ok(()),
1568 // Render the replacements for each suggestion
1569 let suggestions = suggestion.splice_lines(&**sm);
1570 debug!("emit_suggestion_default: suggestions={:?}", suggestions);
1572 if suggestions.is_empty() {
1573 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1574 // approach to avoid ICEs by ignoring the suggestion outright.
1578 let mut buffer = StyledBuffer::new();
1580 // Render the suggestion message
1581 buffer.append(0, level.to_str(), Style::Level(*level));
1582 buffer.append(0, ": ", Style::HeaderMsg);
1586 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1589 Some(Style::HeaderMsg),
1592 let mut row_num = 2;
1593 let mut notice_capitalization = false;
1594 for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) {
1595 notice_capitalization |= only_capitalization;
1596 // Only show underline if the suggestion spans a single line and doesn't cover the
1597 // entirety of the code output. If you have multiple replacements in the same line
1598 // of code, show the underline.
1599 let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim())
1600 && complete.lines().count() == 1;
1603 .span_to_lines(parts[0].span)
1604 .expect("span_to_lines failed when emitting suggestion");
1606 assert!(!lines.lines.is_empty() || parts[0].span.is_dummy());
1608 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1609 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1610 let mut lines = complete.lines();
1611 for (line_pos, line) in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES).enumerate()
1613 // Print the span column to avoid confusion
1617 &self.maybe_anonymized(line_start + line_pos),
1620 // print the suggestion
1621 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1622 buffer.append(row_num, &replace_tabs(line), Style::NoStyle);
1626 // This offset and the ones below need to be signed to account for replacement code
1627 // that is shorter than the original code.
1628 let mut offsets: Vec<(usize, isize)> = Vec::new();
1629 // Only show an underline in the suggestions if the suggestion is not the
1630 // entirety of the code being shown and the displayed code is not multiline.
1632 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1634 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1635 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1637 // Do not underline the leading...
1638 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1639 // ...or trailing spaces. Account for substitutions containing unicode
1641 let sub_len: usize = part
1645 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1648 let offset: isize = offsets
1651 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1654 let underline_start = (span_start_pos + start) as isize + offset;
1655 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1656 assert!(underline_start >= 0 && underline_end >= 0);
1657 for p in underline_start..underline_end {
1660 ((max_line_num_len + 3) as isize + p) as usize,
1662 Style::UnderlinePrimary,
1665 // underline removals too
1666 if underline_start == underline_end {
1667 for p in underline_start - 1..underline_start + 1 {
1670 ((max_line_num_len + 3) as isize + p) as usize,
1672 Style::UnderlineSecondary,
1677 // length of the code after substitution
1678 let full_sub_len = part
1681 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1682 .sum::<usize>() as isize;
1684 // length of the code to be substituted
1685 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1686 // For multiple substitutions, use the position *after* the previous
1687 // substitutions have happened, only when further substitutions are
1688 // located strictly after.
1689 offsets.push((span_end_pos, full_sub_len - snippet_len));
1694 // if we elided some lines, add an ellipsis
1695 if lines.next().is_some() {
1696 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1697 } else if !show_underline {
1698 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1702 if suggestions.len() > MAX_SUGGESTIONS {
1703 let others = suggestions.len() - MAX_SUGGESTIONS;
1704 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1705 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1706 } else if notice_capitalization {
1707 let msg = "notice the capitalization difference";
1708 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1710 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1714 fn emit_messages_default(
1717 message: &[(String, Style)],
1718 code: &Option<DiagnosticId>,
1720 children: &[SubDiagnostic],
1721 suggestions: &[CodeSuggestion],
1723 let max_line_num_len = if self.ui_testing {
1724 ANONYMIZED_LINE_NUM.len()
1726 let n = self.get_max_line_num(span, children);
1727 num_decimal_digits(n)
1730 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1732 if !children.is_empty()
1733 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1735 let mut buffer = StyledBuffer::new();
1736 if !self.short_message {
1737 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1739 if let Err(e) = emit_to_destination(
1745 panic!("failed to emit error: {}", e)
1748 if !self.short_message {
1749 for child in children {
1750 let span = child.render_span.as_ref().unwrap_or(&child.span);
1751 if let Err(err) = self.emit_message_default(
1753 &child.styled_message(),
1759 panic!("failed to emit error: {}", err);
1762 for sugg in suggestions {
1763 if sugg.style == SuggestionStyle::CompletelyHidden {
1764 // do not display this suggestion, it is meant only for tools
1765 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1766 if let Err(e) = self.emit_message_default(
1768 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1774 panic!("failed to emit error: {}", e);
1776 } else if let Err(e) =
1777 self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1779 panic!("failed to emit error: {}", e);
1784 Err(e) => panic!("failed to emit error: {}", e),
1787 let mut dst = self.dst.writable();
1788 match writeln!(dst) {
1789 Err(e) => panic!("failed to emit error: {}", e),
1791 if let Err(e) = dst.flush() {
1792 panic!("failed to emit error: {}", e)
1799 impl FileWithAnnotatedLines {
1800 /// Preprocess all the annotations so that they are grouped by file and by line number
1801 /// This helps us quickly iterate over the whole message (including secondary file spans)
1802 pub fn collect_annotations(
1804 source_map: &Option<Lrc<SourceMap>>,
1805 ) -> Vec<FileWithAnnotatedLines> {
1806 fn add_annotation_to_file(
1807 file_vec: &mut Vec<FileWithAnnotatedLines>,
1808 file: Lrc<SourceFile>,
1812 for slot in file_vec.iter_mut() {
1813 // Look through each of our files for the one we're adding to
1814 if slot.file.name == file.name {
1815 // See if we already have a line for it
1816 for line_slot in &mut slot.lines {
1817 if line_slot.line_index == line_index {
1818 line_slot.annotations.push(ann);
1822 // We don't have a line yet, create one
1823 slot.lines.push(Line { line_index, annotations: vec![ann] });
1828 // This is the first time we're seeing the file
1829 file_vec.push(FileWithAnnotatedLines {
1831 lines: vec![Line { line_index, annotations: vec![ann] }],
1836 let mut output = vec![];
1837 let mut multiline_annotations = vec![];
1839 if let Some(ref sm) = source_map {
1840 for span_label in msp.span_labels() {
1841 if span_label.span.is_dummy() {
1845 let lo = sm.lookup_char_pos(span_label.span.lo());
1846 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1848 // Watch out for "empty spans". If we get a span like 6..6, we
1849 // want to just display a `^` at 6, so convert that to
1850 // 6..7. This is degenerate input, but it's best to degrade
1851 // gracefully -- and the parser likes to supply a span like
1852 // that for EOF, in particular.
1854 if lo.col_display == hi.col_display && lo.line == hi.line {
1855 hi.col_display += 1;
1858 if lo.line != hi.line {
1859 let ml = MultilineAnnotation {
1861 line_start: lo.line,
1863 start_col: lo.col_display,
1864 end_col: hi.col_display,
1865 is_primary: span_label.is_primary,
1866 label: span_label.label,
1867 overlaps_exactly: false,
1869 multiline_annotations.push((lo.file, ml));
1871 let ann = Annotation {
1872 start_col: lo.col_display,
1873 end_col: hi.col_display,
1874 is_primary: span_label.is_primary,
1875 label: span_label.label,
1876 annotation_type: AnnotationType::Singleline,
1878 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1883 // Find overlapping multiline annotations, put them at different depths
1884 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1885 for (_, ann) in multiline_annotations.clone() {
1886 for (_, a) in multiline_annotations.iter_mut() {
1887 // Move all other multiline annotations overlapping with this one
1888 // one level to the right.
1889 if !(ann.same_span(a))
1890 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1893 } else if ann.same_span(a) && &ann != a {
1894 a.overlaps_exactly = true;
1901 let mut max_depth = 0; // max overlapping multiline spans
1902 for (file, ann) in multiline_annotations {
1903 max_depth = max(max_depth, ann.depth);
1904 let mut end_ann = ann.as_end();
1905 if !ann.overlaps_exactly {
1906 // avoid output like
1928 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1929 // 4 is the minimum vertical length of a multiline span when presented: two lines
1930 // of code and two lines of underline. This is not true for the special case where
1931 // the beginning doesn't have an underline, but the current logic seems to be
1932 // working correctly.
1933 let middle = min(ann.line_start + 4, ann.line_end);
1934 for line in ann.line_start + 1..middle {
1935 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1936 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1938 let line_end = ann.line_end - 1;
1939 if middle < line_end {
1940 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
1943 end_ann.annotation_type = AnnotationType::Singleline;
1945 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1947 for file_vec in output.iter_mut() {
1948 file_vec.multiline_depth = max_depth;
1954 // instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
1955 // we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
1956 // is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
1957 // This is also why we need the max number of decimal digits within a `usize`.
1958 fn num_decimal_digits(num: usize) -> usize {
1959 #[cfg(target_pointer_width = "64")]
1960 const MAX_DIGITS: usize = 20;
1962 #[cfg(target_pointer_width = "32")]
1963 const MAX_DIGITS: usize = 10;
1965 #[cfg(target_pointer_width = "16")]
1966 const MAX_DIGITS: usize = 5;
1969 for num_digits in 1..MAX_DIGITS {
1973 lim = lim.wrapping_mul(10);
1978 fn replace_tabs(str: &str) -> String {
1979 str.replace('\t', " ")
1982 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1983 buffer.puts(line, col, "| ", Style::LineNumber);
1986 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1987 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1990 fn draw_col_separator_no_space_with_style(
1991 buffer: &mut StyledBuffer,
1996 buffer.putc(line, col, '|', style);
2000 buffer: &mut StyledBuffer,
2007 for col in col_from..col_to {
2008 buffer.putc(line, col, symbol, style);
2012 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2013 buffer.puts(line, col, "= ", Style::LineNumber);
2016 fn draw_multiline_line(
2017 buffer: &mut StyledBuffer,
2023 buffer.putc(line, offset + depth - 1, '|', style);
2033 let extra = if inclusive { 1 } else { 0 };
2034 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
2036 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
2037 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
2040 fn emit_to_destination(
2041 rendered_buffer: &[Vec<StyledString>],
2043 dst: &mut Destination,
2044 short_message: bool,
2045 ) -> io::Result<()> {
2048 let mut dst = dst.writable();
2050 // In order to prevent error message interleaving, where multiple error lines get intermixed
2051 // when multiple compiler processes error simultaneously, we emit errors with additional
2054 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
2055 // the .flush() is called we take the buffer created from the buffered writes and write it at
2056 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
2057 // scheme, this buffered approach works and maintains the styling.
2059 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
2060 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
2061 // enough to output the full error message, then we release.
2062 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
2063 for (pos, line) in rendered_buffer.iter().enumerate() {
2065 dst.apply_style(*lvl, part.style)?;
2066 write!(dst, "{}", part.text)?;
2069 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2077 pub enum Destination {
2078 Terminal(StandardStream),
2079 Buffered(BufferWriter),
2080 // The bool denotes whether we should be emitting ansi color codes or not
2081 Raw(Box<(dyn Write + Send)>, bool),
2084 pub enum WritableDst<'a> {
2085 Terminal(&'a mut StandardStream),
2086 Buffered(&'a mut BufferWriter, Buffer),
2087 Raw(&'a mut (dyn Write + Send)),
2088 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2092 fn from_stderr(color: ColorConfig) -> Destination {
2093 let choice = color.to_color_choice();
2094 // On Windows we'll be performing global synchronization on the entire
2095 // system for emitting rustc errors, so there's no need to buffer
2098 // On non-Windows we rely on the atomicity of `write` to ensure errors
2099 // don't get all jumbled up.
2101 Terminal(StandardStream::stderr(choice))
2103 Buffered(BufferWriter::stderr(choice))
2107 fn writable(&mut self) -> WritableDst<'_> {
2109 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2110 Destination::Buffered(ref mut t) => {
2111 let buf = t.buffer();
2112 WritableDst::Buffered(t, buf)
2114 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2115 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2119 fn supports_color(&self) -> bool {
2121 Self::Terminal(ref stream) => stream.supports_color(),
2122 Self::Buffered(ref buffer) => buffer.buffer().supports_color(),
2123 Self::Raw(_, supports_color) => supports_color,
2128 impl<'a> WritableDst<'a> {
2129 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2130 let mut spec = ColorSpec::new();
2132 Style::LineAndColumn => {}
2133 Style::LineNumber => {
2134 spec.set_bold(true);
2135 spec.set_intense(true);
2137 spec.set_fg(Some(Color::Cyan));
2139 spec.set_fg(Some(Color::Blue));
2142 Style::Quotation => {}
2143 Style::MainHeaderMsg => {
2144 spec.set_bold(true);
2146 spec.set_intense(true).set_fg(Some(Color::White));
2149 Style::UnderlinePrimary | Style::LabelPrimary => {
2151 spec.set_bold(true);
2153 Style::UnderlineSecondary | Style::LabelSecondary => {
2154 spec.set_bold(true).set_intense(true);
2156 spec.set_fg(Some(Color::Cyan));
2158 spec.set_fg(Some(Color::Blue));
2161 Style::HeaderMsg | Style::NoStyle => {}
2162 Style::Level(lvl) => {
2164 spec.set_bold(true);
2166 Style::Highlight => {
2167 spec.set_bold(true);
2170 self.set_color(&spec)
2173 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2175 WritableDst::Terminal(ref mut t) => t.set_color(color),
2176 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2177 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2178 WritableDst::Raw(_) => Ok(()),
2182 fn reset(&mut self) -> io::Result<()> {
2184 WritableDst::Terminal(ref mut t) => t.reset(),
2185 WritableDst::Buffered(_, ref mut t) => t.reset(),
2186 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2187 WritableDst::Raw(_) => Ok(()),
2192 impl<'a> Write for WritableDst<'a> {
2193 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2195 WritableDst::Terminal(ref mut t) => t.write(bytes),
2196 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2197 WritableDst::Raw(ref mut w) => w.write(bytes),
2198 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2202 fn flush(&mut self) -> io::Result<()> {
2204 WritableDst::Terminal(ref mut t) => t.flush(),
2205 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2206 WritableDst::Raw(ref mut w) => w.flush(),
2207 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2212 impl<'a> Drop for WritableDst<'a> {
2213 fn drop(&mut self) {
2214 if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
2215 drop(dst.print(buf));
2220 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2221 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2222 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2223 let found = match sm.span_to_snippet(sp) {
2224 Ok(snippet) => snippet,
2226 warn!("Invalid span {:?}. Err={:?}", sp, e);
2230 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2231 // All the chars that differ in capitalization are confusable (above):
2232 let confusable = iter::zip(found.chars(), suggested.chars())
2233 .filter(|(f, s)| f != s)
2234 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2235 confusable && found.to_lowercase() == suggested.to_lowercase()
2236 // FIXME: We sometimes suggest the same thing we already have, which is a
2237 // bug, but be defensive against that here.
2238 && found != suggested