3 use syntax_pos::{SourceFile, Span, MultiSpan};
6 Level, CodeSuggestion, DiagnosticBuilder, SubDiagnostic,
7 SuggestionStyle, SourceMapperDyn, DiagnosticId,
9 use crate::Level::Error;
10 use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
11 use crate::styled_buffer::StyledBuffer;
13 use rustc_data_structures::fx::FxHashMap;
14 use rustc_data_structures::sync::Lrc;
16 use std::io::prelude::*;
18 use std::cmp::{min, Reverse};
20 use termcolor::{StandardStream, ColorChoice, ColorSpec, BufferWriter, Ansi};
21 use termcolor::{WriteColor, Color, Buffer};
23 /// Describes the way the content of the `rendered` field of the json output is generated
24 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
25 pub enum HumanReadableErrorType {
27 AnnotateRs(ColorConfig),
31 impl HumanReadableErrorType {
32 /// Returns a (`short`, `color`) tuple
33 pub fn unzip(self) -> (bool, ColorConfig) {
35 HumanReadableErrorType::Default(cc) => (false, cc),
36 HumanReadableErrorType::Short(cc) => (true, cc),
37 HumanReadableErrorType::AnnotateRs(cc) => (false, cc),
42 dst: Box<dyn Write + Send>,
43 source_map: Option<Lrc<SourceMapperDyn>>,
46 let (short, color_config) = self.unzip();
47 EmitterWriter::new(dst, source_map, short, teach, color_config.suggests_using_colors())
51 const ANONYMIZED_LINE_NUM: &str = "LL";
53 /// Emitter trait for emitting errors.
55 /// Emit a structured diagnostic.
56 fn emit_diagnostic(&mut self, db: &DiagnosticBuilder<'_>);
58 /// Emit a notification that an artifact has been output.
59 /// This is currently only supported for the JSON format,
60 /// other formats can, and will, simply ignore it.
61 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
63 /// Checks if should show explanations about "rustc --explain"
64 fn should_show_explain(&self) -> bool {
69 impl Emitter for EmitterWriter {
70 fn emit_diagnostic(&mut self, db: &DiagnosticBuilder<'_>) {
71 let mut primary_span = db.span.clone();
72 let mut children = db.children.clone();
73 let mut suggestions: &[_] = &[];
75 if let Some((sugg, rest)) = db.suggestions.split_first() {
77 // don't display multi-suggestions as labels
78 sugg.substitutions.len() == 1 &&
79 // don't display multipart suggestions as labels
80 sugg.substitutions[0].parts.len() == 1 &&
81 // don't display long messages as labels
82 sugg.msg.split_whitespace().count() < 10 &&
83 // don't display multiline suggestions as labels
84 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
85 // when this style is set we want the suggestion to be a message, not inline
86 sugg.style != SuggestionStyle::HideCodeAlways &&
87 // trivial suggestion for tooling's sake, never shown
88 sugg.style != SuggestionStyle::CompletelyHidden
90 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
91 let msg = if substitution.len() == 0 || sugg.style.hide_inline() {
92 // This substitution is only removal or we explicitly don't want to show the
93 // code inline, don't show it
94 format!("help: {}", sugg.msg)
96 format!("help: {}: `{}`", sugg.msg, substitution)
98 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
100 // if there are multiple suggestions, print them all in full
101 // to be consistent. We could try to figure out if we can
102 // make one (or the first one) inline, but that would give
103 // undue importance to a semi-random suggestion
104 suggestions = &db.suggestions;
108 self.fix_multispans_in_std_macros(&mut primary_span,
111 db.handler.flags.external_macro_backtrace);
113 self.emit_messages_default(&db.level,
114 &db.styled_message(),
121 fn should_show_explain(&self) -> bool {
126 /// maximum number of lines we will print for each error; arbitrary.
127 pub const MAX_HIGHLIGHT_LINES: usize = 6;
128 /// maximum number of suggestions to be shown
130 /// Arbitrary, but taken from trait import suggestion limit
131 pub const MAX_SUGGESTIONS: usize = 4;
133 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
134 pub enum ColorConfig {
141 fn to_color_choice(self) -> ColorChoice {
143 ColorConfig::Always => {
144 if atty::is(atty::Stream::Stderr) {
147 ColorChoice::AlwaysAnsi
150 ColorConfig::Never => ColorChoice::Never,
151 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => {
154 ColorConfig::Auto => ColorChoice::Never,
157 fn suggests_using_colors(self) -> bool {
159 | ColorConfig::Always
162 ColorConfig::Never => false,
167 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
168 pub struct EmitterWriter {
170 sm: Option<Lrc<SourceMapperDyn>>,
177 pub struct FileWithAnnotatedLines {
178 pub file: Lrc<SourceFile>,
179 pub lines: Vec<Line>,
180 multiline_depth: usize,
184 pub fn stderr(color_config: ColorConfig,
185 source_map: Option<Lrc<SourceMapperDyn>>,
189 let dst = Destination::from_stderr(color_config);
200 dst: Box<dyn Write + Send>,
201 source_map: Option<Lrc<SourceMapperDyn>>,
207 dst: Raw(dst, colored),
215 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
216 self.ui_testing = ui_testing;
220 fn maybe_anonymized(&self, line_num: usize) -> String {
222 ANONYMIZED_LINE_NUM.to_string()
228 fn render_source_line(&self,
229 buffer: &mut StyledBuffer,
230 file: Lrc<SourceFile>,
233 code_offset: usize) -> Vec<(usize, Style)> {
234 if line.line_index == 0 {
238 let source_string = match file.get_line(line.line_index - 1) {
240 None => return Vec::new(),
243 let line_offset = buffer.num_lines();
245 // First create the source line we will highlight.
246 buffer.puts(line_offset, code_offset, &source_string, Style::Quotation);
247 buffer.puts(line_offset,
249 &self.maybe_anonymized(line.line_index),
252 draw_col_separator(buffer, line_offset, width_offset - 2);
254 // Special case when there's only one annotation involved, it is the start of a multiline
255 // span and there's no text at the beginning of the code line. Instead of doing the whole
264 // we simplify the output to:
270 if line.annotations.len() == 1 {
271 if let Some(ref ann) = line.annotations.get(0) {
272 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
273 if source_string.chars()
275 .all(|c| c.is_whitespace()) {
276 let style = if ann.is_primary {
277 Style::UnderlinePrimary
279 Style::UnderlineSecondary
281 buffer.putc(line_offset,
282 width_offset + depth - 1,
285 return vec![(depth, style)];
291 // We want to display like this:
293 // vec.push(vec.pop().unwrap());
294 // --- ^^^ - previous borrow ends here
296 // | error occurs here
297 // previous borrow of `vec` occurs here
299 // But there are some weird edge cases to be aware of:
301 // vec.push(vec.pop().unwrap());
302 // -------- - previous borrow ends here
304 // |this makes no sense
305 // previous borrow of `vec` occurs here
307 // For this reason, we group the lines into "highlight lines"
308 // and "annotations lines", where the highlight lines have the `^`.
310 // Sort the annotations by (start, end col)
311 // The labels are reversed, sort and then reversed again.
312 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
313 // the letter signifies the span. Here we are only sorting by the
314 // span and hence, the order of the elements with the same span will
315 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
316 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
317 // still ordered first to last, but all the elements with different
318 // spans are ordered by their spans in last to first order. Last to
319 // first order is important, because the jiggly lines and | are on
320 // the left, so the rightmost span needs to be rendered first,
321 // otherwise the lines would end up needing to go over a message.
323 let mut annotations = line.annotations.clone();
324 annotations.sort_by_key(|a| Reverse(a.start_col));
326 // First, figure out where each label will be positioned.
328 // In the case where you have the following annotations:
330 // vec.push(vec.pop().unwrap());
331 // -------- - previous borrow ends here [C]
333 // |this makes no sense [B]
334 // previous borrow of `vec` occurs here [A]
336 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
338 // We try, when possible, to stick the rightmost annotation at the end
339 // of the highlight line:
341 // vec.push(vec.pop().unwrap());
342 // --- --- - previous borrow ends here
344 // But sometimes that's not possible because one of the other
345 // annotations overlaps it. For example, from the test
346 // `span_overlap_label`, we have the following annotations
347 // (written on distinct lines for clarity):
353 // In this case, we can't stick the rightmost-most label on
354 // the highlight line, or we would get:
361 // which is totally weird. Instead we want:
369 // which is...less weird, at least. In fact, in general, if
370 // the rightmost span overlaps with any other span, we should
371 // use the "hang below" version, so we can at least make it
372 // clear where the span *starts*. There's an exception for this
373 // logic, when the labels do not have a message:
388 let mut annotations_position = vec![];
389 let mut line_len = 0;
391 for (i, annotation) in annotations.iter().enumerate() {
392 for (j, next) in annotations.iter().enumerate() {
393 if overlaps(next, annotation, 0) // This label overlaps with another one and both
394 && annotation.has_label() // take space (they have text and are not
395 && j > i // multiline lines).
396 && p == 0 // We're currently on the first line, move the label one line down
398 // If we're overlapping with an un-labelled annotation with the same span
399 // we can just merge them in the output
400 if next.start_col == annotation.start_col
401 && next.end_col == annotation.end_col
407 // This annotation needs a new line in the output.
412 annotations_position.push((p, annotation));
413 for (j, next) in annotations.iter().enumerate() {
415 let l = if let Some(ref label) = next.label {
420 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
421 // line if they overlap including padding, to
422 // avoid situations like:
429 && annotation.has_label() // Both labels must have some text, otherwise
430 && next.has_label()) // they are not overlapping.
431 // Do not add a new line if this annotation
432 // or the next are vertical line placeholders.
433 || (annotation.takes_space() // If either this or the next annotation is
434 && next.has_label()) // multiline start/end, move it to a new line
435 || (annotation.has_label() // so as not to overlap the orizontal lines.
436 && next.takes_space())
437 || (annotation.takes_space() && next.takes_space())
438 || (overlaps(next, annotation, l)
439 && next.end_col <= annotation.end_col
441 && p == 0) // Avoid #42595.
443 // This annotation needs a new line in the output.
458 // If there are no annotations or the only annotations on this line are
459 // MultilineLine, then there's only code being shown, stop processing.
460 if line.annotations.iter().all(|a| a.is_line()) {
464 // Write the colunmn separator.
466 // After this we will have:
475 for pos in 0..=line_len {
476 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
477 buffer.putc(line_offset + pos + 1,
483 // Write the horizontal lines for multiline annotations
484 // (only the first and last lines need this).
486 // After this we will have:
495 for &(pos, annotation) in &annotations_position {
496 let style = if annotation.is_primary {
497 Style::UnderlinePrimary
499 Style::UnderlineSecondary
502 match annotation.annotation_type {
503 AnnotationType::MultilineStart(depth) |
504 AnnotationType::MultilineEnd(depth) => {
508 width_offset + depth,
509 code_offset + annotation.start_col,
513 buffer.set_style_range(line_offset,
514 code_offset + annotation.start_col,
515 code_offset + annotation.end_col,
517 annotation.is_primary);
523 // Write the vertical lines for labels that are on a different line as the underline.
525 // After this we will have:
534 for &(pos, annotation) in &annotations_position {
535 let style = if annotation.is_primary {
536 Style::UnderlinePrimary
538 Style::UnderlineSecondary
542 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
543 for p in line_offset + 1..=line_offset + pos {
545 code_offset + annotation.start_col,
550 match annotation.annotation_type {
551 AnnotationType::MultilineStart(depth) => {
552 for p in line_offset + pos + 1..line_offset + line_len + 2 {
554 width_offset + depth - 1,
559 AnnotationType::MultilineEnd(depth) => {
560 for p in line_offset..=line_offset + pos {
562 width_offset + depth - 1,
571 // Write the labels on the annotations that actually have a label.
573 // After this we will have:
578 // | something about `foo`
582 for &(pos, annotation) in &annotations_position {
583 let style = if annotation.is_primary {
586 Style::LabelSecondary
588 let (pos, col) = if pos == 0 {
589 (pos + 1, annotation.end_col + 1)
591 (pos + 2, annotation.start_col)
593 if let Some(ref label) = annotation.label {
594 buffer.puts(line_offset + pos,
601 // Sort from biggest span to smallest span so that smaller spans are
602 // represented in the output:
607 // | | something about `foo`
608 // | something about `fn foo()`
609 annotations_position.sort_by(|a, b| {
610 // Decreasing order. When `a` and `b` are the same length, prefer `Primary`.
611 (a.1.len(), !a.1.is_primary).cmp(&(b.1.len(), !b.1.is_primary)).reverse()
614 // Write the underlines.
616 // After this we will have:
621 // | something about `foo`
625 for &(_, annotation) in &annotations_position {
626 let (underline, style) = if annotation.is_primary {
627 ('^', Style::UnderlinePrimary)
629 ('-', Style::UnderlineSecondary)
631 for p in annotation.start_col..annotation.end_col {
632 buffer.putc(line_offset + 1,
638 annotations_position.iter().filter_map(|&(_, annotation)| {
639 match annotation.annotation_type {
640 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
641 let style = if annotation.is_primary {
644 Style::LabelSecondary
651 }).collect::<Vec<_>>()
654 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
656 if let Some(ref sm) = self.sm {
657 for primary_span in msp.primary_spans() {
658 if !primary_span.is_dummy() {
659 let hi = sm.lookup_char_pos(primary_span.hi());
665 if !self.short_message {
666 for span_label in msp.span_labels() {
667 if !span_label.span.is_dummy() {
668 let hi = sm.lookup_char_pos(span_label.span.hi());
679 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
682 let primary = self.get_multispan_max_line_num(span);
683 max = if primary > max { primary } else { max };
685 for sub in children {
686 let sub_result = self.get_multispan_max_line_num(&sub.span);
687 max = if sub_result > max { primary } else { max };
692 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
693 // <*macros>. Since these locations are often difficult to read, we move these Spans from
694 // <*macros> to their corresponding use site.
695 fn fix_multispan_in_std_macros(&mut self,
696 span: &mut MultiSpan,
697 always_backtrace: bool) -> bool {
698 let mut spans_updated = false;
700 if let Some(ref sm) = self.sm {
701 let mut before_after: Vec<(Span, Span)> = vec![];
702 let mut new_labels: Vec<(Span, String)> = vec![];
704 // First, find all the spans in <*macros> and point instead at their use site
705 for sp in span.primary_spans() {
709 let call_sp = sm.call_span_if_macro(*sp);
710 if call_sp != *sp && !always_backtrace {
711 before_after.push((*sp, call_sp));
713 let backtrace_len = sp.macro_backtrace().len();
714 for (i, trace) in sp.macro_backtrace().iter().rev().enumerate() {
715 // Only show macro locations that are local
716 // and display them like a span_note
717 if let Some(def_site) = trace.def_site_span {
718 if def_site.is_dummy() {
721 if always_backtrace {
722 new_labels.push((def_site,
723 format!("in this expansion of `{}`{}",
724 trace.macro_decl_name,
725 if backtrace_len > 2 {
726 // if backtrace_len == 1 it'll be pointed
727 // at by "in this macro invocation"
728 format!(" (#{})", i + 1)
733 // Check to make sure we're not in any <*macros>
734 if !sm.span_to_filename(def_site).is_macros() &&
735 !trace.macro_decl_name.starts_with("desugaring of ") &&
736 !trace.macro_decl_name.starts_with("#[") ||
738 new_labels.push((trace.call_site,
739 format!("in this macro invocation{}",
740 if backtrace_len > 2 && always_backtrace {
741 // only specify order when the macro
742 // backtrace is multiple levels deep
743 format!(" (#{})", i + 1)
747 if !always_backtrace {
754 for (label_span, label_text) in new_labels {
755 span.push_span_label(label_span, label_text);
757 for sp_label in span.span_labels() {
758 if sp_label.span.is_dummy() {
761 if sm.span_to_filename(sp_label.span.clone()).is_macros() &&
764 let v = sp_label.span.macro_backtrace();
765 if let Some(use_site) = v.last() {
766 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
770 // After we have them, make sure we replace these 'bad' def sites with their use sites
771 for (before, after) in before_after {
772 span.replace(before, after);
773 spans_updated = true;
780 // This does a small "fix" for multispans by looking to see if it can find any that
781 // point directly at <*macros>. Since these are often difficult to read, this
782 // will change the span to point at the use site.
783 fn fix_multispans_in_std_macros(&mut self,
784 span: &mut MultiSpan,
785 children: &mut Vec<SubDiagnostic>,
788 let mut spans_updated = self.fix_multispan_in_std_macros(span, backtrace);
789 for child in children.iter_mut() {
790 spans_updated |= self.fix_multispan_in_std_macros(&mut child.span, backtrace);
792 let msg = if level == &Error {
793 "this error originates in a macro outside of the current crate \
794 (in Nightly builds, run with -Z external-macro-backtrace \
795 for more info)".to_string()
797 "this warning originates in a macro outside of the current crate \
798 (in Nightly builds, run with -Z external-macro-backtrace \
799 for more info)".to_string()
803 children.push(SubDiagnostic {
809 span: MultiSpan::new(),
815 /// Adds a left margin to every line but the first, given a padding length and the label being
816 /// displayed, keeping the provided highlighting.
817 fn msg_to_buffer(&self,
818 buffer: &mut StyledBuffer,
819 msg: &[(String, Style)],
822 override_style: Option<Style>) {
824 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
837 // | | length of label
839 // `max_line_num_len`
840 let padding = " ".repeat(padding + label.len() + 5);
842 /// Returns `true` if `style`, or the override if present and the style is `NoStyle`.
843 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
844 if let Some(o) = override_style {
845 if style == Style::NoStyle {
852 let mut line_number = 0;
854 // Provided the following diagnostic message:
858 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
859 // ("looks", Style::Highlight),
860 // ("with\nvery ", Style::NoStyle),
861 // ("weird", Style::Highlight),
862 // (" formats\n", Style::NoStyle),
863 // ("see?", Style::Highlight),
866 // the expected output on a note is (* surround the highlighted text)
868 // = note: highlighted multiline
870 // see how it *looks* with
871 // very *weird* formats
873 for &(ref text, ref style) in msg.iter() {
874 let lines = text.split('\n').collect::<Vec<_>>();
876 for (i, line) in lines.iter().enumerate() {
879 buffer.append(line_number, &padding, Style::NoStyle);
881 buffer.append(line_number, line, style_or_override(*style, override_style));
884 buffer.append(line_number, text, style_or_override(*style, override_style));
889 fn emit_message_default(
892 msg: &[(String, Style)],
893 code: &Option<DiagnosticId>,
895 max_line_num_len: usize,
897 ) -> io::Result<()> {
898 let mut buffer = StyledBuffer::new();
899 let header_style = if is_secondary {
905 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary
906 && !self.short_message {
907 // This is a secondary message with no span info
908 for _ in 0..max_line_num_len {
909 buffer.prepend(0, " ", Style::NoStyle);
911 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
912 let level_str = level.to_string();
913 if !level_str.is_empty() {
914 buffer.append(0, &level_str, Style::MainHeaderMsg);
915 buffer.append(0, ": ", Style::NoStyle);
917 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
919 let level_str = level.to_string();
920 if !level_str.is_empty() {
921 buffer.append(0, &level_str, Style::Level(level.clone()));
923 // only render error codes, not lint codes
924 if let Some(DiagnosticId::Error(ref code)) = *code {
925 buffer.append(0, "[", Style::Level(level.clone()));
926 buffer.append(0, &code, Style::Level(level.clone()));
927 buffer.append(0, "]", Style::Level(level.clone()));
929 if !level_str.is_empty() {
930 buffer.append(0, ": ", header_style);
932 for &(ref text, _) in msg.iter() {
933 buffer.append(0, text, header_style);
937 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
939 // Make sure our primary file comes first
940 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
941 (self.sm.as_ref(), msp.primary_span().as_ref()) {
942 if !primary_span.is_dummy() {
943 (sm.lookup_char_pos(primary_span.lo()), sm)
945 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
949 // If we don't have span information, emit and exit
950 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
954 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
955 annotated_files.swap(0, pos);
958 // Print out the annotate source lines that correspond with the error
959 for annotated_file in annotated_files {
960 // we can't annotate anything if the source is unavailable.
961 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
965 // print out the span location and spacer before we print the annotated source
966 // to do this, we need to know if this span will be primary
967 let is_primary = primary_lo.file.name == annotated_file.file.name;
969 let loc = primary_lo.clone();
970 if !self.short_message {
971 // remember where we are in the output buffer for easy reference
972 let buffer_msg_line_offset = buffer.num_lines();
974 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
975 buffer.append(buffer_msg_line_offset,
978 sm.doctest_offset_line(&loc.file.name, loc.line),
980 Style::LineAndColumn);
981 for _ in 0..max_line_num_len {
982 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
986 &format!("{}:{}:{}: ",
988 sm.doctest_offset_line(&loc.file.name, loc.line),
990 Style::LineAndColumn);
992 } else if !self.short_message {
993 // remember where we are in the output buffer for easy reference
994 let buffer_msg_line_offset = buffer.num_lines();
997 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
999 // Then, the secondary file indicator
1000 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1001 let loc = if let Some(first_line) = annotated_file.lines.first() {
1002 let col = if let Some(first_annotation) = first_line.annotations.first() {
1003 format!(":{}", first_annotation.start_col + 1)
1008 annotated_file.file.name,
1009 sm.doctest_offset_line(
1010 &annotated_file.file.name, first_line.line_index),
1013 annotated_file.file.name.to_string()
1015 buffer.append(buffer_msg_line_offset + 1,
1017 Style::LineAndColumn);
1018 for _ in 0..max_line_num_len {
1019 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1023 if !self.short_message {
1024 // Put in the spacer between the location and annotated source
1025 let buffer_msg_line_offset = buffer.num_lines();
1026 draw_col_separator_no_space(&mut buffer,
1027 buffer_msg_line_offset,
1028 max_line_num_len + 1);
1030 // Contains the vertical lines' positions for active multiline annotations
1031 let mut multilines = FxHashMap::default();
1033 // Next, output the annotate source for this file
1034 for line_idx in 0..annotated_file.lines.len() {
1035 let previous_buffer_line = buffer.num_lines();
1037 let width_offset = 3 + max_line_num_len;
1038 let code_offset = if annotated_file.multiline_depth == 0 {
1041 width_offset + annotated_file.multiline_depth + 1
1044 let depths = self.render_source_line(&mut buffer,
1045 annotated_file.file.clone(),
1046 &annotated_file.lines[line_idx],
1050 let mut to_add = FxHashMap::default();
1052 for (depth, style) in depths {
1053 if multilines.get(&depth).is_some() {
1054 multilines.remove(&depth);
1056 to_add.insert(depth, style);
1060 // Set the multiline annotation vertical lines to the left of
1061 // the code in this line.
1062 for (depth, style) in &multilines {
1063 for line in previous_buffer_line..buffer.num_lines() {
1064 draw_multiline_line(&mut buffer,
1071 // check to see if we need to print out or elide lines that come between
1072 // this annotated line and the next one.
1073 if line_idx < (annotated_file.lines.len() - 1) {
1074 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
1075 annotated_file.lines[line_idx].line_index;
1076 if line_idx_delta > 2 {
1077 let last_buffer_line_num = buffer.num_lines();
1078 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1080 // Set the multiline annotation vertical lines on `...` bridging line.
1081 for (depth, style) in &multilines {
1082 draw_multiline_line(&mut buffer,
1083 last_buffer_line_num,
1088 } else if line_idx_delta == 2 {
1089 let unannotated_line = annotated_file.file
1090 .get_line(annotated_file.lines[line_idx].line_index)
1091 .unwrap_or_else(|| Cow::from(""));
1093 let last_buffer_line_num = buffer.num_lines();
1095 buffer.puts(last_buffer_line_num,
1097 &self.maybe_anonymized(annotated_file.lines[line_idx + 1]
1100 draw_col_separator(&mut buffer,
1101 last_buffer_line_num,
1102 1 + max_line_num_len);
1103 buffer.puts(last_buffer_line_num,
1108 for (depth, style) in &multilines {
1109 draw_multiline_line(&mut buffer,
1110 last_buffer_line_num,
1118 multilines.extend(&to_add);
1123 // final step: take our styled buffer, render it, then output it
1124 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1130 fn emit_suggestion_default(
1132 suggestion: &CodeSuggestion,
1134 max_line_num_len: usize,
1135 ) -> io::Result<()> {
1136 if let Some(ref sm) = self.sm {
1137 let mut buffer = StyledBuffer::new();
1139 // Render the suggestion message
1140 let level_str = level.to_string();
1141 if !level_str.is_empty() {
1142 buffer.append(0, &level_str, Style::Level(level.clone()));
1143 buffer.append(0, ": ", Style::HeaderMsg);
1147 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1150 Some(Style::HeaderMsg),
1153 // Render the replacements for each suggestion
1154 let suggestions = suggestion.splice_lines(&**sm);
1156 let mut row_num = 2;
1157 for &(ref complete, ref parts) in suggestions.iter().take(MAX_SUGGESTIONS) {
1158 // Only show underline if the suggestion spans a single line and doesn't cover the
1159 // entirety of the code output. If you have multiple replacements in the same line
1160 // of code, show the underline.
1161 let show_underline = !(parts.len() == 1
1162 && parts[0].snippet.trim() == complete.trim())
1163 && complete.lines().count() == 1;
1165 let lines = sm.span_to_lines(parts[0].span).unwrap();
1167 assert!(!lines.lines.is_empty());
1169 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1170 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1171 let mut line_pos = 0;
1172 let mut lines = complete.lines();
1173 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1174 // Print the span column to avoid confusion
1175 buffer.puts(row_num,
1177 &self.maybe_anonymized(line_start + line_pos),
1179 // print the suggestion
1180 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1181 buffer.append(row_num, line, Style::NoStyle);
1186 // This offset and the ones below need to be signed to account for replacement code
1187 // that is shorter than the original code.
1188 let mut offset: isize = 0;
1189 // Only show an underline in the suggestions if the suggestion is not the
1190 // entirety of the code being shown and the displayed code is not multiline.
1192 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1194 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1195 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1197 // Do not underline the leading...
1198 let start = part.snippet.len()
1199 .saturating_sub(part.snippet.trim_start().len());
1200 // ...or trailing spaces. Account for substitutions containing unicode
1202 let sub_len = part.snippet.trim().chars().fold(0, |acc, ch| {
1203 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0)
1206 let underline_start = (span_start_pos + start) as isize + offset;
1207 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1208 for p in underline_start..underline_end {
1209 buffer.putc(row_num,
1210 max_line_num_len + 3 + p as usize,
1212 Style::UnderlinePrimary);
1214 // underline removals too
1215 if underline_start == underline_end {
1216 for p in underline_start-1..underline_start+1 {
1217 buffer.putc(row_num,
1218 max_line_num_len + 3 + p as usize,
1220 Style::UnderlineSecondary);
1224 // length of the code after substitution
1225 let full_sub_len = part.snippet.chars().fold(0, |acc, ch| {
1226 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0) as isize
1229 // length of the code to be substituted
1230 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1231 // For multiple substitutions, use the position *after* the previous
1232 // substitutions have happened.
1233 offset += full_sub_len - snippet_len;
1238 // if we elided some lines, add an ellipsis
1239 if lines.next().is_some() {
1240 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1241 } else if !show_underline {
1242 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1246 if suggestions.len() > MAX_SUGGESTIONS {
1247 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1248 buffer.puts(row_num, 0, &msg, Style::NoStyle);
1250 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1255 fn emit_messages_default(&mut self,
1257 message: &[(String, Style)],
1258 code: &Option<DiagnosticId>,
1260 children: &[SubDiagnostic],
1261 suggestions: &[CodeSuggestion]) {
1262 let max_line_num_len = if self.ui_testing {
1263 ANONYMIZED_LINE_NUM.len()
1265 self.get_max_line_num(span, children).to_string().len()
1268 match self.emit_message_default(span,
1275 if !children.is_empty() {
1276 let mut buffer = StyledBuffer::new();
1277 if !self.short_message {
1278 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1280 match emit_to_destination(&buffer.render(), level, &mut self.dst,
1281 self.short_message) {
1283 Err(e) => panic!("failed to emit error: {}", e)
1286 if !self.short_message {
1287 for child in children {
1288 let span = child.render_span.as_ref().unwrap_or(&child.span);
1289 match self.emit_message_default(
1291 &child.styled_message(),
1297 Err(e) => panic!("failed to emit error: {}", e),
1301 for sugg in suggestions {
1302 if sugg.style == SuggestionStyle::CompletelyHidden {
1303 // do not display this suggestion, it is meant only for tools
1304 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1305 match self.emit_message_default(
1307 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1313 Err(e) => panic!("failed to emit error: {}", e),
1317 match self.emit_suggestion_default(
1322 Err(e) => panic!("failed to emit error: {}", e),
1329 Err(e) => panic!("failed to emit error: {}", e),
1332 let mut dst = self.dst.writable();
1333 match write!(dst, "\n") {
1334 Err(e) => panic!("failed to emit error: {}", e),
1337 Err(e) => panic!("failed to emit error: {}", e),
1345 impl FileWithAnnotatedLines {
1346 /// Preprocess all the annotations so that they are grouped by file and by line number
1347 /// This helps us quickly iterate over the whole message (including secondary file spans)
1348 pub fn collect_annotations(
1350 source_map: &Option<Lrc<SourceMapperDyn>>
1351 ) -> Vec<FileWithAnnotatedLines> {
1352 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
1353 file: Lrc<SourceFile>,
1357 for slot in file_vec.iter_mut() {
1358 // Look through each of our files for the one we're adding to
1359 if slot.file.name == file.name {
1360 // See if we already have a line for it
1361 for line_slot in &mut slot.lines {
1362 if line_slot.line_index == line_index {
1363 line_slot.annotations.push(ann);
1367 // We don't have a line yet, create one
1368 slot.lines.push(Line {
1370 annotations: vec![ann],
1376 // This is the first time we're seeing the file
1377 file_vec.push(FileWithAnnotatedLines {
1381 annotations: vec![ann],
1387 let mut output = vec![];
1388 let mut multiline_annotations = vec![];
1390 if let Some(ref sm) = source_map {
1391 for span_label in msp.span_labels() {
1392 if span_label.span.is_dummy() {
1396 let lo = sm.lookup_char_pos(span_label.span.lo());
1397 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1399 // Watch out for "empty spans". If we get a span like 6..6, we
1400 // want to just display a `^` at 6, so convert that to
1401 // 6..7. This is degenerate input, but it's best to degrade
1402 // gracefully -- and the parser likes to supply a span like
1403 // that for EOF, in particular.
1405 if lo.col_display == hi.col_display && lo.line == hi.line {
1406 hi.col_display += 1;
1409 let ann_type = if lo.line != hi.line {
1410 let ml = MultilineAnnotation {
1412 line_start: lo.line,
1414 start_col: lo.col_display,
1415 end_col: hi.col_display,
1416 is_primary: span_label.is_primary,
1417 label: span_label.label.clone(),
1418 overlaps_exactly: false,
1420 multiline_annotations.push((lo.file.clone(), ml.clone()));
1421 AnnotationType::Multiline(ml)
1423 AnnotationType::Singleline
1425 let ann = Annotation {
1426 start_col: lo.col_display,
1427 end_col: hi.col_display,
1428 is_primary: span_label.is_primary,
1429 label: span_label.label.clone(),
1430 annotation_type: ann_type,
1433 if !ann.is_multiline() {
1434 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1439 // Find overlapping multiline annotations, put them at different depths
1440 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1441 for item in multiline_annotations.clone() {
1443 for item in multiline_annotations.iter_mut() {
1444 let ref mut a = item.1;
1445 // Move all other multiline annotations overlapping with this one
1446 // one level to the right.
1447 if !(ann.same_span(a)) &&
1448 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1451 } else if ann.same_span(a) && &ann != a {
1452 a.overlaps_exactly = true;
1459 let mut max_depth = 0; // max overlapping multiline spans
1460 for (file, ann) in multiline_annotations {
1461 if ann.depth > max_depth {
1462 max_depth = ann.depth;
1464 let mut end_ann = ann.as_end();
1465 if !ann.overlaps_exactly {
1466 // avoid output like
1488 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1489 // 4 is the minimum vertical length of a multiline span when presented: two lines
1490 // of code and two lines of underline. This is not true for the special case where
1491 // the beginning doesn't have an underline, but the current logic seems to be
1492 // working correctly.
1493 let middle = min(ann.line_start + 4, ann.line_end);
1494 for line in ann.line_start + 1..middle {
1495 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1496 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1498 if middle < ann.line_end - 1 {
1499 for line in ann.line_end - 1..ann.line_end {
1500 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1504 end_ann.annotation_type = AnnotationType::Singleline;
1506 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1508 for file_vec in output.iter_mut() {
1509 file_vec.multiline_depth = max_depth;
1515 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1516 buffer.puts(line, col, "| ", Style::LineNumber);
1519 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1520 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1523 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1527 buffer.putc(line, col, '|', style);
1530 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1531 col_from: usize, col_to: usize, style: Style) {
1532 for col in col_from..col_to {
1533 buffer.putc(line, col, symbol, style);
1537 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1538 buffer.puts(line, col, "= ", Style::LineNumber);
1541 fn draw_multiline_line(buffer: &mut StyledBuffer,
1547 buffer.putc(line, offset + depth - 1, '|', style);
1550 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1551 let extra = if inclusive {
1556 (b_start..b_end + extra).contains(&a_start) ||
1557 (a_start..a_end + extra).contains(&b_start)
1559 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1560 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1563 fn emit_to_destination(rendered_buffer: &[Vec<StyledString>],
1565 dst: &mut Destination,
1566 short_message: bool)
1570 let mut dst = dst.writable();
1572 // In order to prevent error message interleaving, where multiple error lines get intermixed
1573 // when multiple compiler processes error simultaneously, we emit errors with additional
1576 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1577 // the .flush() is called we take the buffer created from the buffered writes and write it at
1578 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1579 // scheme, this buffered approach works and maintains the styling.
1581 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1582 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1583 // enough to output the full error message, then we release.
1584 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1585 for (pos, line) in rendered_buffer.iter().enumerate() {
1587 dst.apply_style(lvl.clone(), part.style)?;
1588 write!(dst, "{}", part.text)?;
1591 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
1599 pub enum Destination {
1600 Terminal(StandardStream),
1601 Buffered(BufferWriter),
1602 // The bool denotes whether we should be emitting ansi color codes or not
1603 Raw(Box<(dyn Write + Send)>, bool),
1606 pub enum WritableDst<'a> {
1607 Terminal(&'a mut StandardStream),
1608 Buffered(&'a mut BufferWriter, Buffer),
1609 Raw(&'a mut (dyn Write + Send)),
1610 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
1614 fn from_stderr(color: ColorConfig) -> Destination {
1615 let choice = color.to_color_choice();
1616 // On Windows we'll be performing global synchronization on the entire
1617 // system for emitting rustc errors, so there's no need to buffer
1620 // On non-Windows we rely on the atomicity of `write` to ensure errors
1621 // don't get all jumbled up.
1623 Terminal(StandardStream::stderr(choice))
1625 Buffered(BufferWriter::stderr(choice))
1629 fn writable<'a>(&'a mut self) -> WritableDst<'a> {
1631 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
1632 Destination::Buffered(ref mut t) => {
1633 let buf = t.buffer();
1634 WritableDst::Buffered(t, buf)
1636 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
1637 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
1642 impl<'a> WritableDst<'a> {
1643 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1644 let mut spec = ColorSpec::new();
1646 Style::LineAndColumn => {}
1647 Style::LineNumber => {
1648 spec.set_bold(true);
1649 spec.set_intense(true);
1651 spec.set_fg(Some(Color::Cyan));
1653 spec.set_fg(Some(Color::Blue));
1656 Style::Quotation => {}
1657 Style::MainHeaderMsg => {
1658 spec.set_bold(true);
1660 spec.set_intense(true)
1661 .set_fg(Some(Color::White));
1664 Style::UnderlinePrimary | Style::LabelPrimary => {
1666 spec.set_bold(true);
1668 Style::UnderlineSecondary |
1669 Style::LabelSecondary => {
1673 spec.set_fg(Some(Color::Cyan));
1675 spec.set_fg(Some(Color::Blue));
1679 Style::NoStyle => {}
1680 Style::Level(lvl) => {
1682 spec.set_bold(true);
1684 Style::Highlight => {
1685 spec.set_bold(true);
1688 self.set_color(&spec)
1691 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
1693 WritableDst::Terminal(ref mut t) => t.set_color(color),
1694 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
1695 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
1696 WritableDst::Raw(_) => Ok(())
1700 fn reset(&mut self) -> io::Result<()> {
1702 WritableDst::Terminal(ref mut t) => t.reset(),
1703 WritableDst::Buffered(_, ref mut t) => t.reset(),
1704 WritableDst::ColoredRaw(ref mut t) => t.reset(),
1705 WritableDst::Raw(_) => Ok(()),
1710 impl<'a> Write for WritableDst<'a> {
1711 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
1713 WritableDst::Terminal(ref mut t) => t.write(bytes),
1714 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
1715 WritableDst::Raw(ref mut w) => w.write(bytes),
1716 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
1720 fn flush(&mut self) -> io::Result<()> {
1722 WritableDst::Terminal(ref mut t) => t.flush(),
1723 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
1724 WritableDst::Raw(ref mut w) => w.flush(),
1725 WritableDst::ColoredRaw(ref mut w) => w.flush(),
1730 impl<'a> Drop for WritableDst<'a> {
1731 fn drop(&mut self) {
1733 WritableDst::Buffered(ref mut dst, ref mut buf) => {
1734 drop(dst.print(buf));