1 //! The current rustc diagnostics emitter.
3 //! An `Emitter` takes care of generating the output from a `DiagnosticBuilder` struct.
5 //! There are various `Emitter` implementations that generate different output formats such as
6 //! JSON and human readable output.
8 //! The output types are defined in `rustc_session::config::ErrorOutputType`.
12 use rustc_span::source_map::SourceMap;
13 use rustc_span::{MultiSpan, SourceFile, Span};
15 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString};
16 use crate::styled_buffer::StyledBuffer;
18 CodeSuggestion, Diagnostic, DiagnosticId, Handler, Level, SubDiagnostic, SubstitutionHighlight,
22 use rustc_lint_defs::pluralize;
24 use rustc_data_structures::fx::FxHashMap;
25 use rustc_data_structures::sync::Lrc;
26 use rustc_span::hygiene::{ExpnKind, MacroKind};
28 use std::cmp::{max, min, Reverse};
30 use std::io::prelude::*;
33 use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream};
34 use termcolor::{Buffer, Color, WriteColor};
37 /// Default column width, used in tests and when terminal dimensions cannot be determined.
38 const DEFAULT_COLUMN_WIDTH: usize = 140;
40 /// Describes the way the content of the `rendered` field of the json output is generated
41 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
42 pub enum HumanReadableErrorType {
44 AnnotateSnippet(ColorConfig),
48 impl HumanReadableErrorType {
49 /// Returns a (`short`, `color`) tuple
50 pub fn unzip(self) -> (bool, ColorConfig) {
52 HumanReadableErrorType::Default(cc) => (false, cc),
53 HumanReadableErrorType::Short(cc) => (true, cc),
54 HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc),
59 dst: Box<dyn Write + Send>,
60 source_map: Option<Lrc<SourceMap>>,
62 terminal_width: Option<usize>,
63 macro_backtrace: bool,
65 let (short, color_config) = self.unzip();
66 let color = color_config.suggests_using_colors();
67 EmitterWriter::new(dst, source_map, short, teach, color, terminal_width, macro_backtrace)
71 #[derive(Clone, Copy, Debug)]
73 /// The available whitespace in the left that can be consumed when centering.
74 pub whitespace_left: usize,
75 /// The column of the beginning of left-most span.
77 /// The column of the end of right-most span.
78 pub span_right: usize,
79 /// The beginning of the line to be displayed.
80 pub computed_left: usize,
81 /// The end of the line to be displayed.
82 pub computed_right: usize,
83 /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default
85 pub column_width: usize,
86 /// The end column of a span label, including the span. Doesn't account for labels not in the
87 /// same line as the span.
88 pub label_right: usize,
93 whitespace_left: usize,
100 // The 6 is padding to give a bit of room for `...` when displaying:
105 // 16 | ... fn foo(self) -> Self::Bar {
110 whitespace_left: whitespace_left.saturating_sub(6),
111 span_left: span_left.saturating_sub(6),
112 span_right: span_right + 6,
116 label_right: label_right + 6,
118 m.compute(max_line_len);
122 fn was_cut_left(&self) -> bool {
123 self.computed_left > 0
126 fn was_cut_right(&self, line_len: usize) -> bool {
128 if self.computed_right == self.span_right || self.computed_right == self.label_right {
129 // Account for the "..." padding given above. Otherwise we end up with code lines that
130 // do fit but end in "..." as if they were trimmed.
131 self.computed_right - 6
135 right < line_len && self.computed_left + self.column_width < line_len
138 fn compute(&mut self, max_line_len: usize) {
139 // When there's a lot of whitespace (>20), we want to trim it as it is useless.
140 self.computed_left = if self.whitespace_left > 20 {
141 self.whitespace_left - 16 // We want some padding.
145 // We want to show as much as possible, max_line_len is the right-most boundary for the
147 self.computed_right = max(max_line_len, self.computed_left);
149 if self.computed_right - self.computed_left > self.column_width {
150 // Trimming only whitespace isn't enough, let's get craftier.
151 if self.label_right - self.whitespace_left <= self.column_width {
152 // Attempt to fit the code window only trimming whitespace.
153 self.computed_left = self.whitespace_left;
154 self.computed_right = self.computed_left + self.column_width;
155 } else if self.label_right - self.span_left <= self.column_width {
156 // Attempt to fit the code window considering only the spans and labels.
157 let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2;
158 self.computed_left = self.span_left.saturating_sub(padding_left);
159 self.computed_right = self.computed_left + self.column_width;
160 } else if self.span_right - self.span_left <= self.column_width {
161 // Attempt to fit the code window considering the spans and labels plus padding.
162 let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2;
163 self.computed_left = self.span_left.saturating_sub(padding_left);
164 self.computed_right = self.computed_left + self.column_width;
166 // Mostly give up but still don't show the full line.
167 self.computed_left = self.span_left;
168 self.computed_right = self.span_right;
173 fn left(&self, line_len: usize) -> usize {
174 min(self.computed_left, line_len)
177 fn right(&self, line_len: usize) -> usize {
178 if line_len.saturating_sub(self.computed_left) <= self.column_width {
181 min(line_len, self.computed_right)
186 const ANONYMIZED_LINE_NUM: &str = "LL";
188 /// Emitter trait for emitting errors.
190 /// Emit a structured diagnostic.
191 fn emit_diagnostic(&mut self, diag: &Diagnostic);
193 /// Emit a notification that an artifact has been output.
194 /// This is currently only supported for the JSON format,
195 /// other formats can, and will, simply ignore it.
196 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
198 fn emit_future_breakage_report(&mut self, _diags: Vec<Diagnostic>) {}
200 /// Emit list of unused externs
201 fn emit_unused_externs(&mut self, _lint_level: &str, _unused_externs: &[&str]) {}
203 /// Checks if should show explanations about "rustc --explain"
204 fn should_show_explain(&self) -> bool {
208 /// Checks if we can use colors in the current output stream.
209 fn supports_color(&self) -> bool {
213 fn source_map(&self) -> Option<&Lrc<SourceMap>>;
215 /// Formats the substitutions of the primary_span
217 /// There are a lot of conditions to this method, but in short:
219 /// * If the current `Diagnostic` has only one visible `CodeSuggestion`,
220 /// we format the `help` suggestion depending on the content of the
221 /// substitutions. In that case, we return the modified span only.
223 /// * If the current `Diagnostic` has multiple suggestions,
224 /// we return the original `primary_span` and the original suggestions.
225 fn primary_span_formatted<'a>(
227 diag: &'a Diagnostic,
228 ) -> (MultiSpan, &'a [CodeSuggestion]) {
229 let mut primary_span = diag.span.clone();
230 let suggestions = diag.suggestions.as_ref().map_or(&[][..], |suggestions| &suggestions[..]);
231 if let Some((sugg, rest)) = suggestions.split_first() {
232 if rest.is_empty() &&
233 // ^ if there is only one suggestion
234 // don't display multi-suggestions as labels
235 sugg.substitutions.len() == 1 &&
236 // don't display multipart suggestions as labels
237 sugg.substitutions[0].parts.len() == 1 &&
238 // don't display long messages as labels
239 sugg.msg.split_whitespace().count() < 10 &&
240 // don't display multiline suggestions as labels
241 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
243 // when this style is set we want the suggestion to be a message, not inline
244 SuggestionStyle::HideCodeAlways,
245 // trivial suggestion for tooling's sake, never shown
246 SuggestionStyle::CompletelyHidden,
247 // subtle suggestion, never shown inline
248 SuggestionStyle::ShowAlways,
249 ].contains(&sugg.style)
251 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
252 let msg = if substitution.is_empty() || sugg.style.hide_inline() {
253 // This substitution is only removal OR we explicitly don't want to show the
254 // code inline (`hide_inline`). Therefore, we don't show the substitution.
255 format!("help: {}", sugg.msg)
257 // Show the default suggestion text with the substitution
263 .map(|sm| is_case_difference(
266 sugg.substitutions[0].parts[0].span,
270 " (notice the capitalization)"
277 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
279 // We return only the modified primary_span
282 // if there are multiple suggestions, print them all in full
283 // to be consistent. We could try to figure out if we can
284 // make one (or the first one) inline, but that would give
285 // undue importance to a semi-random suggestion
286 (primary_span, suggestions)
289 (primary_span, suggestions)
293 fn fix_multispans_in_extern_macros_and_render_macro_backtrace(
295 source_map: &Option<Lrc<SourceMap>>,
296 span: &mut MultiSpan,
297 children: &mut Vec<SubDiagnostic>,
301 // Check for spans in macros, before `fix_multispans_in_extern_macros`
302 // has a chance to replace them.
303 let has_macro_spans = iter::once(&*span)
304 .chain(children.iter().map(|child| &child.span))
305 .flat_map(|span| span.primary_spans())
306 .flat_map(|sp| sp.macro_backtrace())
307 .find_map(|expn_data| {
308 match expn_data.kind {
309 ExpnKind::Root => None,
311 // Skip past non-macro entries, just in case there
312 // are some which do actually involve macros.
313 ExpnKind::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None,
315 ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)),
320 self.fix_multispans_in_extern_macros(source_map, span, children);
323 self.render_multispans_macro_backtrace(span, children, backtrace);
326 if let Some((macro_kind, name)) = has_macro_spans {
327 let descr = macro_kind.descr();
330 "this {level} originates in the {descr} `{name}` \
331 (in Nightly builds, run with -Z macro-backtrace for more info)",
334 children.push(SubDiagnostic {
336 message: vec![(msg, Style::NoStyle)],
337 span: MultiSpan::new(),
344 fn render_multispans_macro_backtrace(
346 span: &mut MultiSpan,
347 children: &mut Vec<SubDiagnostic>,
350 for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) {
351 self.render_multispan_macro_backtrace(span, backtrace);
355 fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) {
356 let mut new_labels: Vec<(Span, String)> = vec![];
358 for &sp in span.primary_spans() {
363 // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the
364 // entries we don't want to print, to make sure the indices being
365 // printed are contiguous (or omitted if there's only one entry).
366 let macro_backtrace: Vec<_> = sp.macro_backtrace().collect();
367 for (i, trace) in macro_backtrace.iter().rev().enumerate() {
368 if trace.def_site.is_dummy() {
372 if always_backtrace && !matches!(trace.kind, ExpnKind::Inlined) {
376 "in this expansion of `{}`{}",
378 if macro_backtrace.len() > 1 {
379 // if macro_backtrace.len() == 1 it'll be
380 // pointed at by "in this macro invocation"
381 format!(" (#{})", i + 1)
389 // Don't add a label on the call site if the diagnostic itself
390 // already points to (a part of) that call site, as the label
391 // is meant for showing the relevant invocation when the actual
392 // diagnostic is pointing to some part of macro definition.
394 // This also handles the case where an external span got replaced
395 // with the call site span by `fix_multispans_in_extern_macros`.
397 // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the
398 // "in this expansion of" label above is always added in that mode,
399 // and it needs an "in this macro invocation" label to match that.
400 let redundant_span = trace.call_site.contains(sp);
402 if !redundant_span || always_backtrace {
403 let msg: Cow<'static, _> = match trace.kind {
404 ExpnKind::Macro(MacroKind::Attr, _) => {
405 "this procedural macro expansion".into()
407 ExpnKind::Macro(MacroKind::Derive, _) => {
408 "this derive macro expansion".into()
410 ExpnKind::Macro(MacroKind::Bang, _) => "this macro invocation".into(),
411 ExpnKind::Inlined => "this inlined function call".into(),
412 ExpnKind::Root => "the crate root".into(),
413 ExpnKind::AstPass(kind) => kind.descr().into(),
414 ExpnKind::Desugaring(kind) => {
415 format!("this {} desugaring", kind.descr()).into()
423 if macro_backtrace.len() > 1 && always_backtrace {
424 // only specify order when the macro
425 // backtrace is multiple levels deep
426 format!(" (#{})", i + 1)
433 if !always_backtrace {
439 for (label_span, label_text) in new_labels {
440 span.push_span_label(label_span, label_text);
444 // This does a small "fix" for multispans by looking to see if it can find any that
445 // point directly at external macros. Since these are often difficult to read,
446 // this will change the span to point at the use site.
447 fn fix_multispans_in_extern_macros(
449 source_map: &Option<Lrc<SourceMap>>,
450 span: &mut MultiSpan,
451 children: &mut Vec<SubDiagnostic>,
453 let Some(source_map) = source_map else { return };
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 non-fatal diagnostic.
528 /// Fatal diagnostics are forwarded to `fatal_handler` to avoid silent
529 /// failures of rustc, as witnessed e.g. in issue #89358.
530 pub struct SilentEmitter {
531 pub fatal_handler: Handler,
532 pub fatal_note: Option<String>,
535 impl Emitter for SilentEmitter {
536 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
539 fn emit_diagnostic(&mut self, d: &Diagnostic) {
540 if d.level == Level::Fatal {
541 let mut d = d.clone();
542 if let Some(ref note) = self.fatal_note {
545 self.fatal_handler.emit_diagnostic(&d);
550 /// Maximum number of lines we will print for a multiline suggestion; arbitrary.
552 /// This should be replaced with a more involved mechanism to output multiline suggestions that
553 /// more closely mimics the regular diagnostic output, where irrelevant code lines are elided.
554 pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6;
555 /// Maximum number of suggestions to be shown
557 /// Arbitrary, but taken from trait import suggestion limit
558 pub const MAX_SUGGESTIONS: usize = 4;
560 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
561 pub enum ColorConfig {
568 fn to_color_choice(self) -> ColorChoice {
570 ColorConfig::Always => {
571 if atty::is(atty::Stream::Stderr) {
574 ColorChoice::AlwaysAnsi
577 ColorConfig::Never => ColorChoice::Never,
578 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto,
579 ColorConfig::Auto => ColorChoice::Never,
582 fn suggests_using_colors(self) -> bool {
584 ColorConfig::Always | ColorConfig::Auto => true,
585 ColorConfig::Never => false,
590 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
591 pub struct EmitterWriter {
593 sm: Option<Lrc<SourceMap>>,
597 terminal_width: Option<usize>,
599 macro_backtrace: bool,
603 pub struct FileWithAnnotatedLines {
604 pub file: Lrc<SourceFile>,
605 pub lines: Vec<Line>,
606 multiline_depth: usize,
611 color_config: ColorConfig,
612 source_map: Option<Lrc<SourceMap>>,
615 terminal_width: Option<usize>,
616 macro_backtrace: bool,
618 let dst = Destination::from_stderr(color_config);
631 dst: Box<dyn Write + Send>,
632 source_map: Option<Lrc<SourceMap>>,
636 terminal_width: Option<usize>,
637 macro_backtrace: bool,
640 dst: Raw(dst, colored),
650 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
651 self.ui_testing = ui_testing;
655 fn maybe_anonymized(&self, line_num: usize) -> String {
656 if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() }
661 buffer: &mut StyledBuffer,
669 // Tabs are assumed to have been replaced by spaces in calling code.
670 debug_assert!(!source_string.contains('\t'));
671 let line_len = source_string.len();
672 // Create the source line we will highlight.
673 let left = margin.left(line_len);
674 let right = margin.right(line_len);
675 // On long lines, we strip the source line, accounting for unicode.
677 let code: String = source_string
681 // Make sure that the trimming on the right will fall within the terminal width.
682 // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is.
683 // For now, just accept that sometimes the code line will be longer than desired.
684 let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1);
685 if taken + next > right - left {
692 buffer.puts(line_offset, code_offset, &code, Style::Quotation);
693 if margin.was_cut_left() {
694 // We have stripped some code/whitespace from the beginning, make it clear.
695 buffer.puts(line_offset, code_offset, "...", Style::LineNumber);
697 if margin.was_cut_right(line_len) {
698 // We have stripped some code after the right-most span end, make it clear we did so.
699 buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber);
701 buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);
703 draw_col_separator(buffer, line_offset, width_offset - 2);
706 fn render_source_line(
708 buffer: &mut StyledBuffer,
709 file: Lrc<SourceFile>,
714 ) -> Vec<(usize, Style)> {
720 // | secondary span label
722 // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it
724 // | | | actual code found in your source code and the spans we use to mark it
725 // | | when there's too much wasted space to the left, trim it
726 // | vertical divider between the column number and the code
729 if line.line_index == 0 {
733 let source_string = match file.get_line(line.line_index - 1) {
734 Some(s) => normalize_whitespace(&*s),
735 None => return Vec::new(),
738 let line_offset = buffer.num_lines();
741 let left = margin.left(source_string.len());
743 // Account for unicode characters of width !=0 that were removed.
744 let left = source_string
747 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
760 // Special case when there's only one annotation involved, it is the start of a multiline
761 // span and there's no text at the beginning of the code line. Instead of doing the whole
770 // we simplify the output to:
776 if let [ann] = &line.annotations[..] {
777 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
778 if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) {
779 let style = if ann.is_primary {
780 Style::UnderlinePrimary
782 Style::UnderlineSecondary
784 buffer.putc(line_offset, width_offset + depth - 1, '/', style);
785 return vec![(depth, style)];
790 // We want to display like this:
792 // vec.push(vec.pop().unwrap());
793 // --- ^^^ - previous borrow ends here
795 // | error occurs here
796 // previous borrow of `vec` occurs here
798 // But there are some weird edge cases to be aware of:
800 // vec.push(vec.pop().unwrap());
801 // -------- - previous borrow ends here
803 // |this makes no sense
804 // previous borrow of `vec` occurs here
806 // For this reason, we group the lines into "highlight lines"
807 // and "annotations lines", where the highlight lines have the `^`.
809 // Sort the annotations by (start, end col)
810 // The labels are reversed, sort and then reversed again.
811 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
812 // the letter signifies the span. Here we are only sorting by the
813 // span and hence, the order of the elements with the same span will
814 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
815 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
816 // still ordered first to last, but all the elements with different
817 // spans are ordered by their spans in last to first order. Last to
818 // first order is important, because the jiggly lines and | are on
819 // the left, so the rightmost span needs to be rendered first,
820 // otherwise the lines would end up needing to go over a message.
822 let mut annotations = line.annotations.clone();
823 annotations.sort_by_key(|a| Reverse(a.start_col));
825 // First, figure out where each label will be positioned.
827 // In the case where you have the following annotations:
829 // vec.push(vec.pop().unwrap());
830 // -------- - previous borrow ends here [C]
832 // |this makes no sense [B]
833 // previous borrow of `vec` occurs here [A]
835 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
837 // We try, when possible, to stick the rightmost annotation at the end
838 // of the highlight line:
840 // vec.push(vec.pop().unwrap());
841 // --- --- - previous borrow ends here
843 // But sometimes that's not possible because one of the other
844 // annotations overlaps it. For example, from the test
845 // `span_overlap_label`, we have the following annotations
846 // (written on distinct lines for clarity):
852 // In this case, we can't stick the rightmost-most label on
853 // the highlight line, or we would get:
860 // which is totally weird. Instead we want:
868 // which is...less weird, at least. In fact, in general, if
869 // the rightmost span overlaps with any other span, we should
870 // use the "hang below" version, so we can at least make it
871 // clear where the span *starts*. There's an exception for this
872 // logic, when the labels do not have a message:
887 let mut annotations_position = vec![];
888 let mut line_len = 0;
890 for (i, annotation) in annotations.iter().enumerate() {
891 for (j, next) in annotations.iter().enumerate() {
892 if overlaps(next, annotation, 0) // This label overlaps with another one and both
893 && annotation.has_label() // take space (they have text and are not
894 && j > i // multiline lines).
896 // We're currently on the first line, move the label one line down
898 // If we're overlapping with an un-labelled annotation with the same span
899 // we can just merge them in the output
900 if next.start_col == annotation.start_col
901 && next.end_col == annotation.end_col
907 // This annotation needs a new line in the output.
912 annotations_position.push((p, annotation));
913 for (j, next) in annotations.iter().enumerate() {
915 let l = next.label.as_ref().map_or(0, |label| label.len() + 2);
916 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
917 // line if they overlap including padding, to
918 // avoid situations like:
925 && annotation.has_label() // Both labels must have some text, otherwise
926 && next.has_label()) // they are not overlapping.
927 // Do not add a new line if this annotation
928 // or the next are vertical line placeholders.
929 || (annotation.takes_space() // If either this or the next annotation is
930 && next.has_label()) // multiline start/end, move it to a new line
931 || (annotation.has_label() // so as not to overlap the horizontal lines.
932 && next.takes_space())
933 || (annotation.takes_space() && next.takes_space())
934 || (overlaps(next, annotation, l)
935 && next.end_col <= annotation.end_col
940 // This annotation needs a new line in the output.
946 line_len = max(line_len, p);
953 // If there are no annotations or the only annotations on this line are
954 // MultilineLine, then there's only code being shown, stop processing.
955 if line.annotations.iter().all(|a| a.is_line()) {
959 // Write the column separator.
961 // After this we will have:
970 for pos in 0..=line_len {
971 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
974 // Write the horizontal lines for multiline annotations
975 // (only the first and last lines need this).
977 // After this we will have:
986 for &(pos, annotation) in &annotations_position {
987 let style = if annotation.is_primary {
988 Style::UnderlinePrimary
990 Style::UnderlineSecondary
993 match annotation.annotation_type {
994 AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
999 width_offset + depth,
1000 (code_offset + annotation.start_col).saturating_sub(left),
1004 _ if self.teach => {
1005 buffer.set_style_range(
1007 (code_offset + annotation.start_col).saturating_sub(left),
1008 (code_offset + annotation.end_col).saturating_sub(left),
1010 annotation.is_primary,
1017 // Write the vertical lines for labels that are on a different line as the underline.
1019 // After this we will have:
1028 for &(pos, annotation) in &annotations_position {
1029 let style = if annotation.is_primary {
1030 Style::UnderlinePrimary
1032 Style::UnderlineSecondary
1036 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
1037 for p in line_offset + 1..=line_offset + pos {
1040 (code_offset + annotation.start_col).saturating_sub(left),
1046 match annotation.annotation_type {
1047 AnnotationType::MultilineStart(depth) => {
1048 for p in line_offset + pos + 1..line_offset + line_len + 2 {
1049 buffer.putc(p, width_offset + depth - 1, '|', style);
1052 AnnotationType::MultilineEnd(depth) => {
1053 for p in line_offset..=line_offset + pos {
1054 buffer.putc(p, width_offset + depth - 1, '|', style);
1061 // Write the labels on the annotations that actually have a label.
1063 // After this we will have:
1068 // | something about `foo`
1072 for &(pos, annotation) in &annotations_position {
1074 if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
1075 let (pos, col) = if pos == 0 {
1076 (pos + 1, (annotation.end_col + 1).saturating_sub(left))
1078 (pos + 2, annotation.start_col.saturating_sub(left))
1080 if let Some(ref label) = annotation.label {
1081 buffer.puts(line_offset + pos, code_offset + col, &label, style);
1085 // Sort from biggest span to smallest span so that smaller spans are
1086 // represented in the output:
1091 // | | something about `foo`
1092 // | something about `fn foo()`
1093 annotations_position.sort_by_key(|(_, ann)| {
1094 // Decreasing order. When annotations share the same length, prefer `Primary`.
1095 (Reverse(ann.len()), ann.is_primary)
1098 // Write the underlines.
1100 // After this we will have:
1105 // | something about `foo`
1109 for &(_, annotation) in &annotations_position {
1110 let (underline, style) = if annotation.is_primary {
1111 ('^', Style::UnderlinePrimary)
1113 ('-', Style::UnderlineSecondary)
1115 for p in annotation.start_col..annotation.end_col {
1118 (code_offset + p).saturating_sub(left),
1124 annotations_position
1126 .filter_map(|&(_, annotation)| match annotation.annotation_type {
1127 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
1128 let style = if annotation.is_primary {
1131 Style::LabelSecondary
1137 .collect::<Vec<_>>()
1140 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
1141 let Some(ref sm) = self.sm else {
1146 for primary_span in msp.primary_spans() {
1147 if !primary_span.is_dummy() {
1148 let hi = sm.lookup_char_pos(primary_span.hi());
1149 max = (hi.line).max(max);
1152 if !self.short_message {
1153 for span_label in msp.span_labels() {
1154 if !span_label.span.is_dummy() {
1155 let hi = sm.lookup_char_pos(span_label.span.hi());
1156 max = (hi.line).max(max);
1164 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
1165 let primary = self.get_multispan_max_line_num(span);
1168 .map(|sub| self.get_multispan_max_line_num(&sub.span))
1174 /// Adds a left margin to every line but the first, given a padding length and the label being
1175 /// displayed, keeping the provided highlighting.
1178 buffer: &mut StyledBuffer,
1179 msg: &[(String, Style)],
1182 override_style: Option<Style>,
1184 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
1187 // --> file.rs:13:20
1192 // = note: multiline
1197 // | | length of label
1199 // `max_line_num_len`
1200 let padding = " ".repeat(padding + label.len() + 5);
1202 /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise
1203 fn style_or_override(style: Style, override_: Option<Style>) -> Style {
1204 match (style, override_) {
1205 (Style::NoStyle, Some(override_)) => override_,
1210 let mut line_number = 0;
1212 // Provided the following diagnostic message:
1216 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
1217 // ("looks", Style::Highlight),
1218 // ("with\nvery ", Style::NoStyle),
1219 // ("weird", Style::Highlight),
1220 // (" formats\n", Style::NoStyle),
1221 // ("see?", Style::Highlight),
1224 // the expected output on a note is (* surround the highlighted text)
1226 // = note: highlighted multiline
1228 // see how it *looks* with
1229 // very *weird* formats
1231 for &(ref text, ref style) in msg.iter() {
1232 let lines = text.split('\n').collect::<Vec<_>>();
1233 if lines.len() > 1 {
1234 for (i, line) in lines.iter().enumerate() {
1237 buffer.append(line_number, &padding, Style::NoStyle);
1239 buffer.append(line_number, line, style_or_override(*style, override_style));
1242 buffer.append(line_number, text, style_or_override(*style, override_style));
1247 fn emit_message_default(
1250 msg: &[(String, Style)],
1251 code: &Option<DiagnosticId>,
1253 max_line_num_len: usize,
1255 ) -> io::Result<()> {
1256 let mut buffer = StyledBuffer::new();
1258 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message
1260 // This is a secondary message with no span info
1261 for _ in 0..max_line_num_len {
1262 buffer.prepend(0, " ", Style::NoStyle);
1264 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
1265 if *level != Level::FailureNote {
1266 buffer.append(0, level.to_str(), Style::MainHeaderMsg);
1267 buffer.append(0, ": ", Style::NoStyle);
1269 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
1271 let mut label_width = 0;
1272 // The failure note level itself does not provide any useful diagnostic information
1273 if *level != Level::FailureNote {
1274 buffer.append(0, level.to_str(), Style::Level(*level));
1275 label_width += level.to_str().len();
1277 // only render error codes, not lint codes
1278 if let Some(DiagnosticId::Error(ref code)) = *code {
1279 buffer.append(0, "[", Style::Level(*level));
1280 buffer.append(0, &code, Style::Level(*level));
1281 buffer.append(0, "]", Style::Level(*level));
1282 label_width += 2 + code.len();
1284 let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg };
1285 if *level != Level::FailureNote {
1286 buffer.append(0, ": ", header_style);
1289 for &(ref text, _) in msg.iter() {
1290 // Account for newlines to align output to its label.
1291 for (line, text) in normalize_whitespace(text).lines().enumerate() {
1296 if line == 0 { String::new() } else { " ".repeat(label_width) },
1305 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
1307 // Make sure our primary file comes first
1308 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1309 (self.sm.as_ref(), msp.primary_span().as_ref())
1311 if !primary_span.is_dummy() {
1312 (sm.lookup_char_pos(primary_span.lo()), sm)
1314 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1318 // If we don't have span information, emit and exit
1319 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1323 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
1325 annotated_files.swap(0, pos);
1328 // Print out the annotate source lines that correspond with the error
1329 for annotated_file in annotated_files {
1330 // we can't annotate anything if the source is unavailable.
1331 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1335 // print out the span location and spacer before we print the annotated source
1336 // to do this, we need to know if this span will be primary
1337 let is_primary = primary_lo.file.name == annotated_file.file.name;
1339 let loc = primary_lo.clone();
1340 if !self.short_message {
1341 // remember where we are in the output buffer for easy reference
1342 let buffer_msg_line_offset = buffer.num_lines();
1344 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1346 buffer_msg_line_offset,
1349 sm.filename_for_diagnostics(&loc.file.name),
1350 sm.doctest_offset_line(&loc.file.name, loc.line),
1353 Style::LineAndColumn,
1355 for _ in 0..max_line_num_len {
1356 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1363 sm.filename_for_diagnostics(&loc.file.name),
1364 sm.doctest_offset_line(&loc.file.name, loc.line),
1367 Style::LineAndColumn,
1370 } else if !self.short_message {
1371 // remember where we are in the output buffer for easy reference
1372 let buffer_msg_line_offset = buffer.num_lines();
1375 draw_col_separator_no_space(
1377 buffer_msg_line_offset,
1378 max_line_num_len + 1,
1381 // Then, the secondary file indicator
1382 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1383 let loc = if let Some(first_line) = annotated_file.lines.first() {
1384 let col = if let Some(first_annotation) = first_line.annotations.first() {
1385 format!(":{}", first_annotation.start_col + 1)
1391 sm.filename_for_diagnostics(&annotated_file.file.name),
1392 sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
1396 format!("{}", sm.filename_for_diagnostics(&annotated_file.file.name))
1398 buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn);
1399 for _ in 0..max_line_num_len {
1400 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1404 if !self.short_message {
1405 // Put in the spacer between the location and annotated source
1406 let buffer_msg_line_offset = buffer.num_lines();
1407 draw_col_separator_no_space(
1409 buffer_msg_line_offset,
1410 max_line_num_len + 1,
1413 // Contains the vertical lines' positions for active multiline annotations
1414 let mut multilines = FxHashMap::default();
1416 // Get the left-side margin to remove it
1417 let mut whitespace_margin = usize::MAX;
1418 for line_idx in 0..annotated_file.lines.len() {
1419 let file = annotated_file.file.clone();
1420 let line = &annotated_file.lines[line_idx];
1421 if let Some(source_string) = file.get_line(line.line_index - 1) {
1422 let leading_whitespace = source_string
1424 .take_while(|c| c.is_whitespace())
1427 // Tabs are displayed as 4 spaces
1433 if source_string.chars().any(|c| !c.is_whitespace()) {
1434 whitespace_margin = min(whitespace_margin, leading_whitespace);
1438 if whitespace_margin == usize::MAX {
1439 whitespace_margin = 0;
1442 // Left-most column any visible span points at.
1443 let mut span_left_margin = usize::MAX;
1444 for line in &annotated_file.lines {
1445 for ann in &line.annotations {
1446 span_left_margin = min(span_left_margin, ann.start_col);
1447 span_left_margin = min(span_left_margin, ann.end_col);
1450 if span_left_margin == usize::MAX {
1451 span_left_margin = 0;
1454 // Right-most column any visible span points at.
1455 let mut span_right_margin = 0;
1456 let mut label_right_margin = 0;
1457 let mut max_line_len = 0;
1458 for line in &annotated_file.lines {
1461 annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()),
1463 for ann in &line.annotations {
1464 span_right_margin = max(span_right_margin, ann.start_col);
1465 span_right_margin = max(span_right_margin, ann.end_col);
1466 // FIXME: account for labels not in the same line
1467 let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
1468 label_right_margin = max(label_right_margin, ann.end_col + label_right);
1472 let width_offset = 3 + max_line_num_len;
1473 let code_offset = if annotated_file.multiline_depth == 0 {
1476 width_offset + annotated_file.multiline_depth + 1
1479 let column_width = if let Some(width) = self.terminal_width {
1480 width.saturating_sub(code_offset)
1481 } else if self.ui_testing {
1482 DEFAULT_COLUMN_WIDTH
1484 termize::dimensions()
1485 .map(|(w, _)| w.saturating_sub(code_offset))
1486 .unwrap_or(DEFAULT_COLUMN_WIDTH)
1489 let margin = Margin::new(
1498 // Next, output the annotate source for this file
1499 for line_idx in 0..annotated_file.lines.len() {
1500 let previous_buffer_line = buffer.num_lines();
1502 let depths = self.render_source_line(
1504 annotated_file.file.clone(),
1505 &annotated_file.lines[line_idx],
1511 let mut to_add = FxHashMap::default();
1513 for (depth, style) in depths {
1514 if multilines.remove(&depth).is_none() {
1515 to_add.insert(depth, style);
1519 // Set the multiline annotation vertical lines to the left of
1520 // the code in this line.
1521 for (depth, style) in &multilines {
1522 for line in previous_buffer_line..buffer.num_lines() {
1523 draw_multiline_line(&mut buffer, line, width_offset, *depth, *style);
1526 // check to see if we need to print out or elide lines that come between
1527 // this annotated line and the next one.
1528 if line_idx < (annotated_file.lines.len() - 1) {
1529 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index
1530 - annotated_file.lines[line_idx].line_index;
1531 if line_idx_delta > 2 {
1532 let last_buffer_line_num = buffer.num_lines();
1533 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1535 // Set the multiline annotation vertical lines on `...` bridging line.
1536 for (depth, style) in &multilines {
1537 draw_multiline_line(
1539 last_buffer_line_num,
1545 } else if line_idx_delta == 2 {
1546 let unannotated_line = annotated_file
1548 .get_line(annotated_file.lines[line_idx].line_index)
1549 .unwrap_or_else(|| Cow::from(""));
1551 let last_buffer_line_num = buffer.num_lines();
1555 &normalize_whitespace(&unannotated_line),
1556 annotated_file.lines[line_idx + 1].line_index - 1,
1557 last_buffer_line_num,
1563 for (depth, style) in &multilines {
1564 draw_multiline_line(
1566 last_buffer_line_num,
1575 multilines.extend(&to_add);
1580 // final step: take our styled buffer, render it, then output it
1581 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1586 fn emit_suggestion_default(
1588 suggestion: &CodeSuggestion,
1590 max_line_num_len: usize,
1591 ) -> io::Result<()> {
1592 let Some(ref sm) = self.sm else {
1596 // Render the replacements for each suggestion
1597 let suggestions = suggestion.splice_lines(&**sm);
1598 debug!("emit_suggestion_default: suggestions={:?}", suggestions);
1600 if suggestions.is_empty() {
1601 // Suggestions coming from macros can have malformed spans. This is a heavy handed
1602 // approach to avoid ICEs by ignoring the suggestion outright.
1606 let mut buffer = StyledBuffer::new();
1608 // Render the suggestion message
1609 buffer.append(0, level.to_str(), Style::Level(*level));
1610 buffer.append(0, ": ", Style::HeaderMsg);
1614 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1617 Some(Style::HeaderMsg),
1620 let mut row_num = 2;
1621 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1622 let mut notice_capitalization = false;
1623 for (complete, parts, highlights, only_capitalization) in
1624 suggestions.iter().take(MAX_SUGGESTIONS)
1626 notice_capitalization |= only_capitalization;
1628 let has_deletion = parts.iter().any(|p| p.is_deletion());
1629 let is_multiline = complete.lines().count() > 1;
1631 enum DisplaySuggestion {
1637 let show_code_change = if has_deletion && !is_multiline {
1638 DisplaySuggestion::Diff
1639 } else if (parts.len() != 1 || parts[0].snippet.trim() != complete.trim())
1642 DisplaySuggestion::Underline
1644 DisplaySuggestion::None
1647 if let DisplaySuggestion::Diff = show_code_change {
1652 .span_to_lines(parts[0].span)
1653 .expect("span_to_lines failed when emitting suggestion");
1655 assert!(!file_lines.lines.is_empty() || parts[0].span.is_dummy());
1657 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1658 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1659 let mut lines = complete.lines();
1660 if lines.clone().next().is_none() {
1661 // Account for a suggestion to completely remove a line(s) with whitespace (#94192).
1662 let line_end = sm.lookup_char_pos(parts[0].span.hi()).line;
1663 for line in line_start..=line_end {
1665 row_num - 1 + line - line_start,
1667 &self.maybe_anonymized(line),
1671 row_num - 1 + line - line_start,
1672 max_line_num_len + 1,
1677 row_num - 1 + line - line_start,
1678 max_line_num_len + 3,
1679 &normalize_whitespace(&*file_lines.file.get_line(line - 1).unwrap()),
1683 row_num += line_end - line_start;
1685 for (line_pos, (line, highlight_parts)) in
1686 lines.by_ref().zip(highlights).take(MAX_SUGGESTION_HIGHLIGHT_LINES).enumerate()
1688 // Print the span column to avoid confusion
1692 &self.maybe_anonymized(line_start + line_pos),
1695 if let DisplaySuggestion::Diff = show_code_change {
1696 // Add the line number for both addition and removal to drive the point home.
1698 // N - fn foo<A: T>(bar: A) {
1699 // N + fn foo(bar: impl T) {
1703 &self.maybe_anonymized(line_start + line_pos),
1706 buffer.puts(row_num - 1, max_line_num_len + 1, "- ", Style::Removal);
1709 max_line_num_len + 3,
1710 &normalize_whitespace(
1713 .get_line(file_lines.lines[line_pos].line_index)
1718 buffer.puts(row_num, max_line_num_len + 1, "+ ", Style::Addition);
1719 } else if is_multiline {
1720 match &highlight_parts[..] {
1721 [SubstitutionHighlight { start: 0, end }] if *end == line.len() => {
1722 buffer.puts(row_num, max_line_num_len + 1, "+ ", Style::Addition);
1725 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1728 buffer.puts(row_num, max_line_num_len + 1, "~ ", Style::Addition);
1732 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1735 // print the suggestion
1736 buffer.append(row_num, &normalize_whitespace(line), Style::NoStyle);
1738 // Colorize addition/replacements with green.
1739 for &SubstitutionHighlight { start, end } in highlight_parts {
1740 // Account for tabs when highlighting (#87972).
1741 let tabs: usize = line
1744 .map(|ch| match ch {
1749 buffer.set_style_range(
1751 max_line_num_len + 3 + start + tabs,
1752 max_line_num_len + 3 + end + tabs,
1760 // This offset and the ones below need to be signed to account for replacement code
1761 // that is shorter than the original code.
1762 let mut offsets: Vec<(usize, isize)> = Vec::new();
1763 // Only show an underline in the suggestions if the suggestion is not the
1764 // entirety of the code being shown and the displayed code is not multiline.
1765 if let DisplaySuggestion::Diff | DisplaySuggestion::Underline = show_code_change {
1766 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1768 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1769 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1771 // Do not underline the leading...
1772 let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len());
1773 // ...or trailing spaces. Account for substitutions containing unicode
1775 let sub_len: usize = part
1779 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1782 let offset: isize = offsets
1785 |(start, v)| if span_start_pos <= *start { None } else { Some(v) },
1788 let underline_start = (span_start_pos + start) as isize + offset;
1789 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1790 assert!(underline_start >= 0 && underline_end >= 0);
1791 let padding: usize = max_line_num_len + 3;
1792 for p in underline_start..underline_end {
1793 if let DisplaySuggestion::Underline = show_code_change {
1794 // If this is a replacement, underline with `^`, if this is an addition
1795 // underline with `+`.
1798 (padding as isize + p) as usize,
1799 if part.is_addition(&sm) { '+' } else { '~' },
1804 if let DisplaySuggestion::Diff = show_code_change {
1805 // Colorize removal with red in diff format.
1806 buffer.set_style_range(
1808 (padding as isize + span_start_pos as isize) as usize,
1809 (padding as isize + span_end_pos as isize) as usize,
1815 // length of the code after substitution
1816 let full_sub_len = part
1819 .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1))
1820 .sum::<usize>() as isize;
1822 // length of the code to be substituted
1823 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1824 // For multiple substitutions, use the position *after* the previous
1825 // substitutions have happened, only when further substitutions are
1826 // located strictly after.
1827 offsets.push((span_end_pos, full_sub_len - snippet_len));
1832 // if we elided some lines, add an ellipsis
1833 if lines.next().is_some() {
1834 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1835 } else if let DisplaySuggestion::None = show_code_change {
1836 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1840 if suggestions.len() > MAX_SUGGESTIONS {
1841 let others = suggestions.len() - MAX_SUGGESTIONS;
1842 let msg = format!("and {} other candidate{}", others, pluralize!(others));
1843 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1844 } else if notice_capitalization {
1845 let msg = "notice the capitalization difference";
1846 buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle);
1848 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1852 fn emit_messages_default(
1855 message: &[(String, Style)],
1856 code: &Option<DiagnosticId>,
1858 children: &[SubDiagnostic],
1859 suggestions: &[CodeSuggestion],
1861 let max_line_num_len = if self.ui_testing {
1862 ANONYMIZED_LINE_NUM.len()
1864 let n = self.get_max_line_num(span, children);
1865 num_decimal_digits(n)
1868 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1870 if !children.is_empty()
1871 || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden)
1873 let mut buffer = StyledBuffer::new();
1874 if !self.short_message {
1875 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1877 if let Err(e) = emit_to_destination(
1883 panic!("failed to emit error: {}", e)
1886 if !self.short_message {
1887 for child in children {
1888 let span = child.render_span.as_ref().unwrap_or(&child.span);
1889 if let Err(err) = self.emit_message_default(
1891 &child.styled_message(),
1897 panic!("failed to emit error: {}", err);
1900 for sugg in suggestions {
1901 if sugg.style == SuggestionStyle::CompletelyHidden {
1902 // do not display this suggestion, it is meant only for tools
1903 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1904 if let Err(e) = self.emit_message_default(
1906 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1912 panic!("failed to emit error: {}", e);
1914 } else if let Err(e) =
1915 self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len)
1917 panic!("failed to emit error: {}", e);
1922 Err(e) => panic!("failed to emit error: {}", e),
1925 let mut dst = self.dst.writable();
1926 match writeln!(dst) {
1927 Err(e) => panic!("failed to emit error: {}", e),
1929 if let Err(e) = dst.flush() {
1930 panic!("failed to emit error: {}", e)
1937 impl FileWithAnnotatedLines {
1938 /// Preprocess all the annotations so that they are grouped by file and by line number
1939 /// This helps us quickly iterate over the whole message (including secondary file spans)
1940 pub fn collect_annotations(
1942 source_map: &Option<Lrc<SourceMap>>,
1943 ) -> Vec<FileWithAnnotatedLines> {
1944 fn add_annotation_to_file(
1945 file_vec: &mut Vec<FileWithAnnotatedLines>,
1946 file: Lrc<SourceFile>,
1950 for slot in file_vec.iter_mut() {
1951 // Look through each of our files for the one we're adding to
1952 if slot.file.name == file.name {
1953 // See if we already have a line for it
1954 for line_slot in &mut slot.lines {
1955 if line_slot.line_index == line_index {
1956 line_slot.annotations.push(ann);
1960 // We don't have a line yet, create one
1961 slot.lines.push(Line { line_index, annotations: vec![ann] });
1966 // This is the first time we're seeing the file
1967 file_vec.push(FileWithAnnotatedLines {
1969 lines: vec![Line { line_index, annotations: vec![ann] }],
1974 let mut output = vec![];
1975 let mut multiline_annotations = vec![];
1977 if let Some(ref sm) = source_map {
1978 for span_label in msp.span_labels() {
1979 if span_label.span.is_dummy() {
1983 let lo = sm.lookup_char_pos(span_label.span.lo());
1984 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1986 // Watch out for "empty spans". If we get a span like 6..6, we
1987 // want to just display a `^` at 6, so convert that to
1988 // 6..7. This is degenerate input, but it's best to degrade
1989 // gracefully -- and the parser likes to supply a span like
1990 // that for EOF, in particular.
1992 if lo.col_display == hi.col_display && lo.line == hi.line {
1993 hi.col_display += 1;
1996 if lo.line != hi.line {
1997 let ml = MultilineAnnotation {
1999 line_start: lo.line,
2001 start_col: lo.col_display,
2002 end_col: hi.col_display,
2003 is_primary: span_label.is_primary,
2004 label: span_label.label,
2005 overlaps_exactly: false,
2007 multiline_annotations.push((lo.file, ml));
2009 let ann = Annotation {
2010 start_col: lo.col_display,
2011 end_col: hi.col_display,
2012 is_primary: span_label.is_primary,
2013 label: span_label.label,
2014 annotation_type: AnnotationType::Singleline,
2016 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
2021 // Find overlapping multiline annotations, put them at different depths
2022 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
2023 for (_, ann) in multiline_annotations.clone() {
2024 for (_, a) in multiline_annotations.iter_mut() {
2025 // Move all other multiline annotations overlapping with this one
2026 // one level to the right.
2027 if !(ann.same_span(a))
2028 && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
2031 } else if ann.same_span(a) && &ann != a {
2032 a.overlaps_exactly = true;
2039 let mut max_depth = 0; // max overlapping multiline spans
2040 for (file, ann) in multiline_annotations {
2041 max_depth = max(max_depth, ann.depth);
2042 let mut end_ann = ann.as_end();
2043 if !ann.overlaps_exactly {
2044 // avoid output like
2066 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
2067 // 4 is the minimum vertical length of a multiline span when presented: two lines
2068 // of code and two lines of underline. This is not true for the special case where
2069 // the beginning doesn't have an underline, but the current logic seems to be
2070 // working correctly.
2071 let middle = min(ann.line_start + 4, ann.line_end);
2072 for line in ann.line_start + 1..middle {
2073 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
2074 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
2076 let line_end = ann.line_end - 1;
2077 if middle < line_end {
2078 add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line());
2081 end_ann.annotation_type = AnnotationType::Singleline;
2083 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
2085 for file_vec in output.iter_mut() {
2086 file_vec.multiline_depth = max_depth;
2092 // instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
2093 // we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
2094 // is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
2095 // This is also why we need the max number of decimal digits within a `usize`.
2096 fn num_decimal_digits(num: usize) -> usize {
2097 #[cfg(target_pointer_width = "64")]
2098 const MAX_DIGITS: usize = 20;
2100 #[cfg(target_pointer_width = "32")]
2101 const MAX_DIGITS: usize = 10;
2103 #[cfg(target_pointer_width = "16")]
2104 const MAX_DIGITS: usize = 5;
2107 for num_digits in 1..MAX_DIGITS {
2111 lim = lim.wrapping_mul(10);
2116 // We replace some characters so the CLI output is always consistent and underlines aligned.
2117 const OUTPUT_REPLACEMENTS: &[(char, &str)] = &[
2118 ('\t', " "), // We do our own tab replacement
2119 ('\u{200D}', ""), // Replace ZWJ with nothing for consistent terminal output of grapheme clusters.
2120 ('\u{202A}', ""), // The following unicode text flow control characters are inconsistently
2121 ('\u{202B}', ""), // supported across CLIs and can cause confusion due to the bytes on disk
2122 ('\u{202D}', ""), // not corresponding to the visible source code, so we replace them always.
2131 fn normalize_whitespace(str: &str) -> String {
2132 let mut s = str.to_string();
2133 for (c, replacement) in OUTPUT_REPLACEMENTS {
2134 s = s.replace(*c, replacement);
2139 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2140 buffer.puts(line, col, "| ", Style::LineNumber);
2143 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
2144 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
2147 fn draw_col_separator_no_space_with_style(
2148 buffer: &mut StyledBuffer,
2153 buffer.putc(line, col, '|', style);
2157 buffer: &mut StyledBuffer,
2164 for col in col_from..col_to {
2165 buffer.putc(line, col, symbol, style);
2169 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
2170 buffer.puts(line, col, "= ", Style::LineNumber);
2173 fn draw_multiline_line(
2174 buffer: &mut StyledBuffer,
2180 buffer.putc(line, offset + depth - 1, '|', style);
2190 let extra = if inclusive { 1 } else { 0 };
2191 (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start)
2193 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
2194 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
2197 fn emit_to_destination(
2198 rendered_buffer: &[Vec<StyledString>],
2200 dst: &mut Destination,
2201 short_message: bool,
2202 ) -> io::Result<()> {
2205 let mut dst = dst.writable();
2207 // In order to prevent error message interleaving, where multiple error lines get intermixed
2208 // when multiple compiler processes error simultaneously, we emit errors with additional
2211 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
2212 // the .flush() is called we take the buffer created from the buffered writes and write it at
2213 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
2214 // scheme, this buffered approach works and maintains the styling.
2216 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
2217 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
2218 // enough to output the full error message, then we release.
2219 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
2220 for (pos, line) in rendered_buffer.iter().enumerate() {
2222 dst.apply_style(*lvl, part.style)?;
2223 write!(dst, "{}", part.text)?;
2226 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
2234 pub enum Destination {
2235 Terminal(StandardStream),
2236 Buffered(BufferWriter),
2237 // The bool denotes whether we should be emitting ansi color codes or not
2238 Raw(Box<(dyn Write + Send)>, bool),
2241 pub enum WritableDst<'a> {
2242 Terminal(&'a mut StandardStream),
2243 Buffered(&'a mut BufferWriter, Buffer),
2244 Raw(&'a mut (dyn Write + Send)),
2245 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
2249 fn from_stderr(color: ColorConfig) -> Destination {
2250 let choice = color.to_color_choice();
2251 // On Windows we'll be performing global synchronization on the entire
2252 // system for emitting rustc errors, so there's no need to buffer
2255 // On non-Windows we rely on the atomicity of `write` to ensure errors
2256 // don't get all jumbled up.
2258 Terminal(StandardStream::stderr(choice))
2260 Buffered(BufferWriter::stderr(choice))
2264 fn writable(&mut self) -> WritableDst<'_> {
2266 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
2267 Destination::Buffered(ref mut t) => {
2268 let buf = t.buffer();
2269 WritableDst::Buffered(t, buf)
2271 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
2272 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
2276 fn supports_color(&self) -> bool {
2278 Self::Terminal(ref stream) => stream.supports_color(),
2279 Self::Buffered(ref buffer) => buffer.buffer().supports_color(),
2280 Self::Raw(_, supports_color) => supports_color,
2285 impl<'a> WritableDst<'a> {
2286 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
2287 let mut spec = ColorSpec::new();
2289 Style::Addition => {
2290 spec.set_fg(Some(Color::Green)).set_intense(true);
2293 spec.set_fg(Some(Color::Red)).set_intense(true);
2295 Style::LineAndColumn => {}
2296 Style::LineNumber => {
2297 spec.set_bold(true);
2298 spec.set_intense(true);
2300 spec.set_fg(Some(Color::Cyan));
2302 spec.set_fg(Some(Color::Blue));
2305 Style::Quotation => {}
2306 Style::MainHeaderMsg => {
2307 spec.set_bold(true);
2309 spec.set_intense(true).set_fg(Some(Color::White));
2312 Style::UnderlinePrimary | Style::LabelPrimary => {
2314 spec.set_bold(true);
2316 Style::UnderlineSecondary | Style::LabelSecondary => {
2317 spec.set_bold(true).set_intense(true);
2319 spec.set_fg(Some(Color::Cyan));
2321 spec.set_fg(Some(Color::Blue));
2324 Style::HeaderMsg | Style::NoStyle => {}
2325 Style::Level(lvl) => {
2327 spec.set_bold(true);
2329 Style::Highlight => {
2330 spec.set_bold(true);
2333 self.set_color(&spec)
2336 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
2338 WritableDst::Terminal(ref mut t) => t.set_color(color),
2339 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
2340 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
2341 WritableDst::Raw(_) => Ok(()),
2345 fn reset(&mut self) -> io::Result<()> {
2347 WritableDst::Terminal(ref mut t) => t.reset(),
2348 WritableDst::Buffered(_, ref mut t) => t.reset(),
2349 WritableDst::ColoredRaw(ref mut t) => t.reset(),
2350 WritableDst::Raw(_) => Ok(()),
2355 impl<'a> Write for WritableDst<'a> {
2356 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
2358 WritableDst::Terminal(ref mut t) => t.write(bytes),
2359 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
2360 WritableDst::Raw(ref mut w) => w.write(bytes),
2361 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
2365 fn flush(&mut self) -> io::Result<()> {
2367 WritableDst::Terminal(ref mut t) => t.flush(),
2368 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
2369 WritableDst::Raw(ref mut w) => w.flush(),
2370 WritableDst::ColoredRaw(ref mut w) => w.flush(),
2375 impl<'a> Drop for WritableDst<'a> {
2376 fn drop(&mut self) {
2377 if let WritableDst::Buffered(ref mut dst, ref mut buf) = self {
2378 drop(dst.print(buf));
2383 /// Whether the original and suggested code are visually similar enough to warrant extra wording.
2384 pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool {
2385 // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode.
2386 let found = match sm.span_to_snippet(sp) {
2387 Ok(snippet) => snippet,
2389 warn!(error = ?e, "Invalid span {:?}", sp);
2393 let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z'];
2394 // All the chars that differ in capitalization are confusable (above):
2395 let confusable = iter::zip(found.chars(), suggested.chars())
2396 .filter(|(f, s)| f != s)
2397 .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s)));
2398 confusable && found.to_lowercase() == suggested.to_lowercase()
2399 // FIXME: We sometimes suggest the same thing we already have, which is a
2400 // bug, but be defensive against that here.
2401 && found != suggested