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 {
30 impl HumanReadableErrorType {
31 /// Returns a (`short`, `color`) tuple
32 pub fn unzip(self) -> (bool, ColorConfig) {
34 HumanReadableErrorType::Default(cc) => (false, cc),
35 HumanReadableErrorType::Short(cc) => (true, cc),
40 dst: Box<dyn Write + Send>,
41 source_map: Option<Lrc<SourceMapperDyn>>,
44 let (short, color_config) = self.unzip();
45 EmitterWriter::new(dst, source_map, short, teach, color_config.suggests_using_colors())
49 const ANONYMIZED_LINE_NUM: &str = "LL";
51 /// Emitter trait for emitting errors.
53 /// Emit a structured diagnostic.
54 fn emit_diagnostic(&mut self, db: &DiagnosticBuilder<'_>);
56 /// Emit a notification that an artifact has been output.
57 /// This is currently only supported for the JSON format,
58 /// other formats can, and will, simply ignore it.
59 fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
61 /// Checks if should show explanations about "rustc --explain"
62 fn should_show_explain(&self) -> bool {
67 impl Emitter for EmitterWriter {
68 fn emit_diagnostic(&mut self, db: &DiagnosticBuilder<'_>) {
69 let mut primary_span = db.span.clone();
70 let mut children = db.children.clone();
71 let mut suggestions: &[_] = &[];
73 if let Some((sugg, rest)) = db.suggestions.split_first() {
75 // don't display multi-suggestions as labels
76 sugg.substitutions.len() == 1 &&
77 // don't display multipart suggestions as labels
78 sugg.substitutions[0].parts.len() == 1 &&
79 // don't display long messages as labels
80 sugg.msg.split_whitespace().count() < 10 &&
81 // don't display multiline suggestions as labels
82 !sugg.substitutions[0].parts[0].snippet.contains('\n') &&
83 // when this style is set we want the suggestion to be a message, not inline
84 sugg.style != SuggestionStyle::HideCodeAlways &&
85 // trivial suggestion for tooling's sake, never shown
86 sugg.style != SuggestionStyle::CompletelyHidden
88 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
89 let msg = if substitution.len() == 0 || sugg.style.hide_inline() {
90 // This substitution is only removal or we explicitly don't want to show the
91 // code inline, don't show it
92 format!("help: {}", sugg.msg)
94 format!("help: {}: `{}`", sugg.msg, substitution)
96 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
98 // if there are multiple suggestions, print them all in full
99 // to be consistent. We could try to figure out if we can
100 // make one (or the first one) inline, but that would give
101 // undue importance to a semi-random suggestion
102 suggestions = &db.suggestions;
106 self.fix_multispans_in_std_macros(&mut primary_span,
109 db.handler.flags.external_macro_backtrace);
111 self.emit_messages_default(&db.level,
112 &db.styled_message(),
119 fn should_show_explain(&self) -> bool {
124 /// maximum number of lines we will print for each error; arbitrary.
125 pub const MAX_HIGHLIGHT_LINES: usize = 6;
126 /// maximum number of suggestions to be shown
128 /// Arbitrary, but taken from trait import suggestion limit
129 pub const MAX_SUGGESTIONS: usize = 4;
131 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
132 pub enum ColorConfig {
139 fn to_color_choice(self) -> ColorChoice {
141 ColorConfig::Always => {
142 if atty::is(atty::Stream::Stderr) {
145 ColorChoice::AlwaysAnsi
148 ColorConfig::Never => ColorChoice::Never,
149 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => {
152 ColorConfig::Auto => ColorChoice::Never,
155 fn suggests_using_colors(self) -> bool {
157 | ColorConfig::Always
160 ColorConfig::Never => false,
165 /// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short`
166 pub struct EmitterWriter {
168 sm: Option<Lrc<SourceMapperDyn>>,
175 pub struct FileWithAnnotatedLines {
176 file: Lrc<SourceFile>,
178 multiline_depth: usize,
182 pub fn stderr(color_config: ColorConfig,
183 source_map: Option<Lrc<SourceMapperDyn>>,
187 let dst = Destination::from_stderr(color_config);
198 dst: Box<dyn Write + Send>,
199 source_map: Option<Lrc<SourceMapperDyn>>,
205 dst: Raw(dst, colored),
213 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
214 self.ui_testing = ui_testing;
218 fn maybe_anonymized(&self, line_num: usize) -> String {
220 ANONYMIZED_LINE_NUM.to_string()
226 fn render_source_line(&self,
227 buffer: &mut StyledBuffer,
228 file: Lrc<SourceFile>,
231 code_offset: usize) -> Vec<(usize, Style)> {
232 if line.line_index == 0 {
236 let source_string = match file.get_line(line.line_index - 1) {
238 None => return Vec::new(),
241 let line_offset = buffer.num_lines();
243 // First create the source line we will highlight.
244 buffer.puts(line_offset, code_offset, &source_string, Style::Quotation);
245 buffer.puts(line_offset,
247 &self.maybe_anonymized(line.line_index),
250 draw_col_separator(buffer, line_offset, width_offset - 2);
252 // Special case when there's only one annotation involved, it is the start of a multiline
253 // span and there's no text at the beginning of the code line. Instead of doing the whole
262 // we simplify the output to:
268 if line.annotations.len() == 1 {
269 if let Some(ref ann) = line.annotations.get(0) {
270 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
271 if source_string.chars()
273 .all(|c| c.is_whitespace()) {
274 let style = if ann.is_primary {
275 Style::UnderlinePrimary
277 Style::UnderlineSecondary
279 buffer.putc(line_offset,
280 width_offset + depth - 1,
283 return vec![(depth, style)];
289 // We want to display like this:
291 // vec.push(vec.pop().unwrap());
292 // --- ^^^ - previous borrow ends here
294 // | error occurs here
295 // previous borrow of `vec` occurs here
297 // But there are some weird edge cases to be aware of:
299 // vec.push(vec.pop().unwrap());
300 // -------- - previous borrow ends here
302 // |this makes no sense
303 // previous borrow of `vec` occurs here
305 // For this reason, we group the lines into "highlight lines"
306 // and "annotations lines", where the highlight lines have the `^`.
308 // Sort the annotations by (start, end col)
309 // The labels are reversed, sort and then reversed again.
310 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
311 // the letter signifies the span. Here we are only sorting by the
312 // span and hence, the order of the elements with the same span will
313 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
314 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
315 // still ordered first to last, but all the elements with different
316 // spans are ordered by their spans in last to first order. Last to
317 // first order is important, because the jiggly lines and | are on
318 // the left, so the rightmost span needs to be rendered first,
319 // otherwise the lines would end up needing to go over a message.
321 let mut annotations = line.annotations.clone();
322 annotations.sort_by_key(|a| Reverse(a.start_col));
324 // First, figure out where each label will be positioned.
326 // In the case where you have the following annotations:
328 // vec.push(vec.pop().unwrap());
329 // -------- - previous borrow ends here [C]
331 // |this makes no sense [B]
332 // previous borrow of `vec` occurs here [A]
334 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
336 // We try, when possible, to stick the rightmost annotation at the end
337 // of the highlight line:
339 // vec.push(vec.pop().unwrap());
340 // --- --- - previous borrow ends here
342 // But sometimes that's not possible because one of the other
343 // annotations overlaps it. For example, from the test
344 // `span_overlap_label`, we have the following annotations
345 // (written on distinct lines for clarity):
351 // In this case, we can't stick the rightmost-most label on
352 // the highlight line, or we would get:
359 // which is totally weird. Instead we want:
367 // which is...less weird, at least. In fact, in general, if
368 // the rightmost span overlaps with any other span, we should
369 // use the "hang below" version, so we can at least make it
370 // clear where the span *starts*. There's an exception for this
371 // logic, when the labels do not have a message:
386 let mut annotations_position = vec![];
387 let mut line_len = 0;
389 for (i, annotation) in annotations.iter().enumerate() {
390 for (j, next) in annotations.iter().enumerate() {
391 if overlaps(next, annotation, 0) // This label overlaps with another one and both
392 && annotation.has_label() // take space (they have text and are not
393 && j > i // multiline lines).
394 && p == 0 // We're currently on the first line, move the label one line down
396 // If we're overlapping with an un-labelled annotation with the same span
397 // we can just merge them in the output
398 if next.start_col == annotation.start_col
399 && next.end_col == annotation.end_col
405 // This annotation needs a new line in the output.
410 annotations_position.push((p, annotation));
411 for (j, next) in annotations.iter().enumerate() {
413 let l = if let Some(ref label) = next.label {
418 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
419 // line if they overlap including padding, to
420 // avoid situations like:
427 && annotation.has_label() // Both labels must have some text, otherwise
428 && next.has_label()) // they are not overlapping.
429 // Do not add a new line if this annotation
430 // or the next are vertical line placeholders.
431 || (annotation.takes_space() // If either this or the next annotation is
432 && next.has_label()) // multiline start/end, move it to a new line
433 || (annotation.has_label() // so as not to overlap the orizontal lines.
434 && next.takes_space())
435 || (annotation.takes_space() && next.takes_space())
436 || (overlaps(next, annotation, l)
437 && next.end_col <= annotation.end_col
439 && p == 0) // Avoid #42595.
441 // This annotation needs a new line in the output.
456 // If there are no annotations or the only annotations on this line are
457 // MultilineLine, then there's only code being shown, stop processing.
458 if line.annotations.iter().all(|a| a.is_line()) {
462 // Write the colunmn separator.
464 // After this we will have:
473 for pos in 0..=line_len {
474 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
475 buffer.putc(line_offset + pos + 1,
481 // Write the horizontal lines for multiline annotations
482 // (only the first and last lines need this).
484 // After this we will have:
493 for &(pos, annotation) in &annotations_position {
494 let style = if annotation.is_primary {
495 Style::UnderlinePrimary
497 Style::UnderlineSecondary
500 match annotation.annotation_type {
501 AnnotationType::MultilineStart(depth) |
502 AnnotationType::MultilineEnd(depth) => {
506 width_offset + depth,
507 code_offset + annotation.start_col,
511 buffer.set_style_range(line_offset,
512 code_offset + annotation.start_col,
513 code_offset + annotation.end_col,
515 annotation.is_primary);
521 // Write the vertical lines for labels that are on a different line as the underline.
523 // After this we will have:
532 for &(pos, annotation) in &annotations_position {
533 let style = if annotation.is_primary {
534 Style::UnderlinePrimary
536 Style::UnderlineSecondary
540 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
541 for p in line_offset + 1..=line_offset + pos {
543 code_offset + annotation.start_col,
548 match annotation.annotation_type {
549 AnnotationType::MultilineStart(depth) => {
550 for p in line_offset + pos + 1..line_offset + line_len + 2 {
552 width_offset + depth - 1,
557 AnnotationType::MultilineEnd(depth) => {
558 for p in line_offset..=line_offset + pos {
560 width_offset + depth - 1,
569 // Write the labels on the annotations that actually have a label.
571 // After this we will have:
576 // | something about `foo`
580 for &(pos, annotation) in &annotations_position {
581 let style = if annotation.is_primary {
584 Style::LabelSecondary
586 let (pos, col) = if pos == 0 {
587 (pos + 1, annotation.end_col + 1)
589 (pos + 2, annotation.start_col)
591 if let Some(ref label) = annotation.label {
592 buffer.puts(line_offset + pos,
599 // Sort from biggest span to smallest span so that smaller spans are
600 // represented in the output:
605 // | | something about `foo`
606 // | something about `fn foo()`
607 annotations_position.sort_by(|a, b| {
608 // Decreasing order. When `a` and `b` are the same length, prefer `Primary`.
609 (a.1.len(), !a.1.is_primary).cmp(&(b.1.len(), !b.1.is_primary)).reverse()
612 // Write the underlines.
614 // After this we will have:
619 // | something about `foo`
623 for &(_, annotation) in &annotations_position {
624 let (underline, style) = if annotation.is_primary {
625 ('^', Style::UnderlinePrimary)
627 ('-', Style::UnderlineSecondary)
629 for p in annotation.start_col..annotation.end_col {
630 buffer.putc(line_offset + 1,
636 annotations_position.iter().filter_map(|&(_, annotation)| {
637 match annotation.annotation_type {
638 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
639 let style = if annotation.is_primary {
642 Style::LabelSecondary
649 }).collect::<Vec<_>>()
652 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
654 if let Some(ref sm) = self.sm {
655 for primary_span in msp.primary_spans() {
656 if !primary_span.is_dummy() {
657 let hi = sm.lookup_char_pos(primary_span.hi());
663 if !self.short_message {
664 for span_label in msp.span_labels() {
665 if !span_label.span.is_dummy() {
666 let hi = sm.lookup_char_pos(span_label.span.hi());
677 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
680 let primary = self.get_multispan_max_line_num(span);
681 max = if primary > max { primary } else { max };
683 for sub in children {
684 let sub_result = self.get_multispan_max_line_num(&sub.span);
685 max = if sub_result > max { primary } else { max };
690 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
691 // <*macros>. Since these locations are often difficult to read, we move these Spans from
692 // <*macros> to their corresponding use site.
693 fn fix_multispan_in_std_macros(&mut self,
694 span: &mut MultiSpan,
695 always_backtrace: bool) -> bool {
696 let mut spans_updated = false;
698 if let Some(ref sm) = self.sm {
699 let mut before_after: Vec<(Span, Span)> = vec![];
700 let mut new_labels: Vec<(Span, String)> = vec![];
702 // First, find all the spans in <*macros> and point instead at their use site
703 for sp in span.primary_spans() {
707 let call_sp = sm.call_span_if_macro(*sp);
708 if call_sp != *sp && !always_backtrace {
709 before_after.push((*sp, call_sp));
711 let backtrace_len = sp.macro_backtrace().len();
712 for (i, trace) in sp.macro_backtrace().iter().rev().enumerate() {
713 // Only show macro locations that are local
714 // and display them like a span_note
715 if let Some(def_site) = trace.def_site_span {
716 if def_site.is_dummy() {
719 if always_backtrace {
720 new_labels.push((def_site,
721 format!("in this expansion of `{}`{}",
722 trace.macro_decl_name,
723 if backtrace_len > 2 {
724 // if backtrace_len == 1 it'll be pointed
725 // at by "in this macro invocation"
726 format!(" (#{})", i + 1)
731 // Check to make sure we're not in any <*macros>
732 if !sm.span_to_filename(def_site).is_macros() &&
733 !trace.macro_decl_name.starts_with("desugaring of ") &&
734 !trace.macro_decl_name.starts_with("#[") ||
736 new_labels.push((trace.call_site,
737 format!("in this macro invocation{}",
738 if backtrace_len > 2 && always_backtrace {
739 // only specify order when the macro
740 // backtrace is multiple levels deep
741 format!(" (#{})", i + 1)
745 if !always_backtrace {
752 for (label_span, label_text) in new_labels {
753 span.push_span_label(label_span, label_text);
755 for sp_label in span.span_labels() {
756 if sp_label.span.is_dummy() {
759 if sm.span_to_filename(sp_label.span.clone()).is_macros() &&
762 let v = sp_label.span.macro_backtrace();
763 if let Some(use_site) = v.last() {
764 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
768 // After we have them, make sure we replace these 'bad' def sites with their use sites
769 for (before, after) in before_after {
770 span.replace(before, after);
771 spans_updated = true;
778 // This does a small "fix" for multispans by looking to see if it can find any that
779 // point directly at <*macros>. Since these are often difficult to read, this
780 // will change the span to point at the use site.
781 fn fix_multispans_in_std_macros(&mut self,
782 span: &mut MultiSpan,
783 children: &mut Vec<SubDiagnostic>,
786 let mut spans_updated = self.fix_multispan_in_std_macros(span, backtrace);
787 for child in children.iter_mut() {
788 spans_updated |= self.fix_multispan_in_std_macros(&mut child.span, backtrace);
790 let msg = if level == &Error {
791 "this error originates in a macro outside of the current crate \
792 (in Nightly builds, run with -Z external-macro-backtrace \
793 for more info)".to_string()
795 "this warning originates in a macro outside of the current crate \
796 (in Nightly builds, run with -Z external-macro-backtrace \
797 for more info)".to_string()
801 children.push(SubDiagnostic {
807 span: MultiSpan::new(),
813 /// Adds a left margin to every line but the first, given a padding length and the label being
814 /// displayed, keeping the provided highlighting.
815 fn msg_to_buffer(&self,
816 buffer: &mut StyledBuffer,
817 msg: &[(String, Style)],
820 override_style: Option<Style>) {
822 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
835 // | | length of label
837 // `max_line_num_len`
838 let padding = " ".repeat(padding + label.len() + 5);
840 /// Returns `true` if `style`, or the override if present and the style is `NoStyle`.
841 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
842 if let Some(o) = override_style {
843 if style == Style::NoStyle {
850 let mut line_number = 0;
852 // Provided the following diagnostic message:
856 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
857 // ("looks", Style::Highlight),
858 // ("with\nvery ", Style::NoStyle),
859 // ("weird", Style::Highlight),
860 // (" formats\n", Style::NoStyle),
861 // ("see?", Style::Highlight),
864 // the expected output on a note is (* surround the highlighted text)
866 // = note: highlighted multiline
868 // see how it *looks* with
869 // very *weird* formats
871 for &(ref text, ref style) in msg.iter() {
872 let lines = text.split('\n').collect::<Vec<_>>();
874 for (i, line) in lines.iter().enumerate() {
877 buffer.append(line_number, &padding, Style::NoStyle);
879 buffer.append(line_number, line, style_or_override(*style, override_style));
882 buffer.append(line_number, text, style_or_override(*style, override_style));
887 fn emit_message_default(
890 msg: &[(String, Style)],
891 code: &Option<DiagnosticId>,
893 max_line_num_len: usize,
895 ) -> io::Result<()> {
896 let mut buffer = StyledBuffer::new();
897 let header_style = if is_secondary {
903 if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary
904 && !self.short_message {
905 // This is a secondary message with no span info
906 for _ in 0..max_line_num_len {
907 buffer.prepend(0, " ", Style::NoStyle);
909 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
910 let level_str = level.to_string();
911 if !level_str.is_empty() {
912 buffer.append(0, &level_str, Style::MainHeaderMsg);
913 buffer.append(0, ": ", Style::NoStyle);
915 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
917 let level_str = level.to_string();
918 if !level_str.is_empty() {
919 buffer.append(0, &level_str, Style::Level(level.clone()));
921 // only render error codes, not lint codes
922 if let Some(DiagnosticId::Error(ref code)) = *code {
923 buffer.append(0, "[", Style::Level(level.clone()));
924 buffer.append(0, &code, Style::Level(level.clone()));
925 buffer.append(0, "]", Style::Level(level.clone()));
927 if !level_str.is_empty() {
928 buffer.append(0, ": ", header_style);
930 for &(ref text, _) in msg.iter() {
931 buffer.append(0, text, header_style);
935 let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm);
937 // Make sure our primary file comes first
938 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
939 (self.sm.as_ref(), msp.primary_span().as_ref()) {
940 if !primary_span.is_dummy() {
941 (sm.lookup_char_pos(primary_span.lo()), sm)
943 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
947 // If we don't have span information, emit and exit
948 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
952 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
953 annotated_files.swap(0, pos);
956 // Print out the annotate source lines that correspond with the error
957 for annotated_file in annotated_files {
958 // we can't annotate anything if the source is unavailable.
959 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
963 // print out the span location and spacer before we print the annotated source
964 // to do this, we need to know if this span will be primary
965 let is_primary = primary_lo.file.name == annotated_file.file.name;
967 let loc = primary_lo.clone();
968 if !self.short_message {
969 // remember where we are in the output buffer for easy reference
970 let buffer_msg_line_offset = buffer.num_lines();
972 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
973 buffer.append(buffer_msg_line_offset,
976 sm.doctest_offset_line(&loc.file.name, loc.line),
978 Style::LineAndColumn);
979 for _ in 0..max_line_num_len {
980 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
984 &format!("{}:{}:{}: ",
986 sm.doctest_offset_line(&loc.file.name, loc.line),
988 Style::LineAndColumn);
990 } else if !self.short_message {
991 // remember where we are in the output buffer for easy reference
992 let buffer_msg_line_offset = buffer.num_lines();
995 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
997 // Then, the secondary file indicator
998 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
999 let loc = if let Some(first_line) = annotated_file.lines.first() {
1000 let col = if let Some(first_annotation) = first_line.annotations.first() {
1001 format!(":{}", first_annotation.start_col + 1)
1006 annotated_file.file.name,
1007 sm.doctest_offset_line(
1008 &annotated_file.file.name, first_line.line_index),
1011 annotated_file.file.name.to_string()
1013 buffer.append(buffer_msg_line_offset + 1,
1015 Style::LineAndColumn);
1016 for _ in 0..max_line_num_len {
1017 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1021 if !self.short_message {
1022 // Put in the spacer between the location and annotated source
1023 let buffer_msg_line_offset = buffer.num_lines();
1024 draw_col_separator_no_space(&mut buffer,
1025 buffer_msg_line_offset,
1026 max_line_num_len + 1);
1028 // Contains the vertical lines' positions for active multiline annotations
1029 let mut multilines = FxHashMap::default();
1031 // Next, output the annotate source for this file
1032 for line_idx in 0..annotated_file.lines.len() {
1033 let previous_buffer_line = buffer.num_lines();
1035 let width_offset = 3 + max_line_num_len;
1036 let code_offset = if annotated_file.multiline_depth == 0 {
1039 width_offset + annotated_file.multiline_depth + 1
1042 let depths = self.render_source_line(&mut buffer,
1043 annotated_file.file.clone(),
1044 &annotated_file.lines[line_idx],
1048 let mut to_add = FxHashMap::default();
1050 for (depth, style) in depths {
1051 if multilines.get(&depth).is_some() {
1052 multilines.remove(&depth);
1054 to_add.insert(depth, style);
1058 // Set the multiline annotation vertical lines to the left of
1059 // the code in this line.
1060 for (depth, style) in &multilines {
1061 for line in previous_buffer_line..buffer.num_lines() {
1062 draw_multiline_line(&mut buffer,
1069 // check to see if we need to print out or elide lines that come between
1070 // this annotated line and the next one.
1071 if line_idx < (annotated_file.lines.len() - 1) {
1072 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
1073 annotated_file.lines[line_idx].line_index;
1074 if line_idx_delta > 2 {
1075 let last_buffer_line_num = buffer.num_lines();
1076 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1078 // Set the multiline annotation vertical lines on `...` bridging line.
1079 for (depth, style) in &multilines {
1080 draw_multiline_line(&mut buffer,
1081 last_buffer_line_num,
1086 } else if line_idx_delta == 2 {
1087 let unannotated_line = annotated_file.file
1088 .get_line(annotated_file.lines[line_idx].line_index)
1089 .unwrap_or_else(|| Cow::from(""));
1091 let last_buffer_line_num = buffer.num_lines();
1093 buffer.puts(last_buffer_line_num,
1095 &self.maybe_anonymized(annotated_file.lines[line_idx + 1]
1098 draw_col_separator(&mut buffer,
1099 last_buffer_line_num,
1100 1 + max_line_num_len);
1101 buffer.puts(last_buffer_line_num,
1106 for (depth, style) in &multilines {
1107 draw_multiline_line(&mut buffer,
1108 last_buffer_line_num,
1116 multilines.extend(&to_add);
1121 // final step: take our styled buffer, render it, then output it
1122 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1128 fn emit_suggestion_default(
1130 suggestion: &CodeSuggestion,
1132 max_line_num_len: usize,
1133 ) -> io::Result<()> {
1134 if let Some(ref sm) = self.sm {
1135 let mut buffer = StyledBuffer::new();
1137 // Render the suggestion message
1138 let level_str = level.to_string();
1139 if !level_str.is_empty() {
1140 buffer.append(0, &level_str, Style::Level(level.clone()));
1141 buffer.append(0, ": ", Style::HeaderMsg);
1145 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1148 Some(Style::HeaderMsg),
1151 // Render the replacements for each suggestion
1152 let suggestions = suggestion.splice_lines(&**sm);
1154 let mut row_num = 2;
1155 for &(ref complete, ref parts) in suggestions.iter().take(MAX_SUGGESTIONS) {
1156 // Only show underline if the suggestion spans a single line and doesn't cover the
1157 // entirety of the code output. If you have multiple replacements in the same line
1158 // of code, show the underline.
1159 let show_underline = !(parts.len() == 1
1160 && parts[0].snippet.trim() == complete.trim())
1161 && complete.lines().count() == 1;
1163 let lines = sm.span_to_lines(parts[0].span).unwrap();
1165 assert!(!lines.lines.is_empty());
1167 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1168 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1169 let mut line_pos = 0;
1170 let mut lines = complete.lines();
1171 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1172 // Print the span column to avoid confusion
1173 buffer.puts(row_num,
1175 &self.maybe_anonymized(line_start + line_pos),
1177 // print the suggestion
1178 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1179 buffer.append(row_num, line, Style::NoStyle);
1184 // This offset and the ones below need to be signed to account for replacement code
1185 // that is shorter than the original code.
1186 let mut offset: isize = 0;
1187 // Only show an underline in the suggestions if the suggestion is not the
1188 // entirety of the code being shown and the displayed code is not multiline.
1190 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1192 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1193 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1195 // Do not underline the leading...
1196 let start = part.snippet.len()
1197 .saturating_sub(part.snippet.trim_start().len());
1198 // ...or trailing spaces. Account for substitutions containing unicode
1200 let sub_len = part.snippet.trim().chars().fold(0, |acc, ch| {
1201 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0)
1204 let underline_start = (span_start_pos + start) as isize + offset;
1205 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1206 for p in underline_start..underline_end {
1207 buffer.putc(row_num,
1208 max_line_num_len + 3 + p as usize,
1210 Style::UnderlinePrimary);
1212 // underline removals too
1213 if underline_start == underline_end {
1214 for p in underline_start-1..underline_start+1 {
1215 buffer.putc(row_num,
1216 max_line_num_len + 3 + p as usize,
1218 Style::UnderlineSecondary);
1222 // length of the code after substitution
1223 let full_sub_len = part.snippet.chars().fold(0, |acc, ch| {
1224 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0) as isize
1227 // length of the code to be substituted
1228 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1229 // For multiple substitutions, use the position *after* the previous
1230 // substitutions have happened.
1231 offset += full_sub_len - snippet_len;
1236 // if we elided some lines, add an ellipsis
1237 if lines.next().is_some() {
1238 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1239 } else if !show_underline {
1240 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1244 if suggestions.len() > MAX_SUGGESTIONS {
1245 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1246 buffer.puts(row_num, 0, &msg, Style::NoStyle);
1248 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1253 fn emit_messages_default(&mut self,
1255 message: &[(String, Style)],
1256 code: &Option<DiagnosticId>,
1258 children: &[SubDiagnostic],
1259 suggestions: &[CodeSuggestion]) {
1260 let max_line_num_len = if self.ui_testing {
1261 ANONYMIZED_LINE_NUM.len()
1263 self.get_max_line_num(span, children).to_string().len()
1266 match self.emit_message_default(span,
1273 if !children.is_empty() {
1274 let mut buffer = StyledBuffer::new();
1275 if !self.short_message {
1276 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1278 match emit_to_destination(&buffer.render(), level, &mut self.dst,
1279 self.short_message) {
1281 Err(e) => panic!("failed to emit error: {}", e)
1284 if !self.short_message {
1285 for child in children {
1286 let span = child.render_span.as_ref().unwrap_or(&child.span);
1287 match self.emit_message_default(
1289 &child.styled_message(),
1295 Err(e) => panic!("failed to emit error: {}", e),
1299 for sugg in suggestions {
1300 if sugg.style == SuggestionStyle::CompletelyHidden {
1301 // do not display this suggestion, it is meant only for tools
1302 } else if sugg.style == SuggestionStyle::HideCodeAlways {
1303 match self.emit_message_default(
1305 &[(sugg.msg.to_owned(), Style::HeaderMsg)],
1311 Err(e) => panic!("failed to emit error: {}", e),
1315 match self.emit_suggestion_default(
1320 Err(e) => panic!("failed to emit error: {}", e),
1327 Err(e) => panic!("failed to emit error: {}", e),
1330 let mut dst = self.dst.writable();
1331 match write!(dst, "\n") {
1332 Err(e) => panic!("failed to emit error: {}", e),
1335 Err(e) => panic!("failed to emit error: {}", e),
1343 impl FileWithAnnotatedLines {
1344 /// Preprocess all the annotations so that they are grouped by file and by line number
1345 /// This helps us quickly iterate over the whole message (including secondary file spans)
1346 pub fn collect_annotations(
1348 source_map: &Option<Lrc<SourceMapperDyn>>
1349 ) -> Vec<FileWithAnnotatedLines> {
1350 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
1351 file: Lrc<SourceFile>,
1355 for slot in file_vec.iter_mut() {
1356 // Look through each of our files for the one we're adding to
1357 if slot.file.name == file.name {
1358 // See if we already have a line for it
1359 for line_slot in &mut slot.lines {
1360 if line_slot.line_index == line_index {
1361 line_slot.annotations.push(ann);
1365 // We don't have a line yet, create one
1366 slot.lines.push(Line {
1368 annotations: vec![ann],
1374 // This is the first time we're seeing the file
1375 file_vec.push(FileWithAnnotatedLines {
1379 annotations: vec![ann],
1385 let mut output = vec![];
1386 let mut multiline_annotations = vec![];
1388 if let Some(ref sm) = source_map {
1389 for span_label in msp.span_labels() {
1390 if span_label.span.is_dummy() {
1394 let lo = sm.lookup_char_pos(span_label.span.lo());
1395 let mut hi = sm.lookup_char_pos(span_label.span.hi());
1397 // Watch out for "empty spans". If we get a span like 6..6, we
1398 // want to just display a `^` at 6, so convert that to
1399 // 6..7. This is degenerate input, but it's best to degrade
1400 // gracefully -- and the parser likes to supply a span like
1401 // that for EOF, in particular.
1403 if lo.col_display == hi.col_display && lo.line == hi.line {
1404 hi.col_display += 1;
1407 let ann_type = if lo.line != hi.line {
1408 let ml = MultilineAnnotation {
1410 line_start: lo.line,
1412 start_col: lo.col_display,
1413 end_col: hi.col_display,
1414 is_primary: span_label.is_primary,
1415 label: span_label.label.clone(),
1416 overlaps_exactly: false,
1418 multiline_annotations.push((lo.file.clone(), ml.clone()));
1419 AnnotationType::Multiline(ml)
1421 AnnotationType::Singleline
1423 let ann = Annotation {
1424 start_col: lo.col_display,
1425 end_col: hi.col_display,
1426 is_primary: span_label.is_primary,
1427 label: span_label.label.clone(),
1428 annotation_type: ann_type,
1431 if !ann.is_multiline() {
1432 add_annotation_to_file(&mut output, lo.file, lo.line, ann);
1437 // Find overlapping multiline annotations, put them at different depths
1438 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
1439 for item in multiline_annotations.clone() {
1441 for item in multiline_annotations.iter_mut() {
1442 let ref mut a = item.1;
1443 // Move all other multiline annotations overlapping with this one
1444 // one level to the right.
1445 if !(ann.same_span(a)) &&
1446 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
1449 } else if ann.same_span(a) && &ann != a {
1450 a.overlaps_exactly = true;
1457 let mut max_depth = 0; // max overlapping multiline spans
1458 for (file, ann) in multiline_annotations {
1459 if ann.depth > max_depth {
1460 max_depth = ann.depth;
1462 let mut end_ann = ann.as_end();
1463 if !ann.overlaps_exactly {
1464 // avoid output like
1486 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
1487 // 4 is the minimum vertical length of a multiline span when presented: two lines
1488 // of code and two lines of underline. This is not true for the special case where
1489 // the beginning doesn't have an underline, but the current logic seems to be
1490 // working correctly.
1491 let middle = min(ann.line_start + 4, ann.line_end);
1492 for line in ann.line_start + 1..middle {
1493 // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`).
1494 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1496 if middle < ann.line_end - 1 {
1497 for line in ann.line_end - 1..ann.line_end {
1498 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
1502 end_ann.annotation_type = AnnotationType::Singleline;
1504 add_annotation_to_file(&mut output, file, ann.line_end, end_ann);
1506 for file_vec in output.iter_mut() {
1507 file_vec.multiline_depth = max_depth;
1513 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1514 buffer.puts(line, col, "| ", Style::LineNumber);
1517 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1518 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1521 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1525 buffer.putc(line, col, '|', style);
1528 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1529 col_from: usize, col_to: usize, style: Style) {
1530 for col in col_from..col_to {
1531 buffer.putc(line, col, symbol, style);
1535 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1536 buffer.puts(line, col, "= ", Style::LineNumber);
1539 fn draw_multiline_line(buffer: &mut StyledBuffer,
1545 buffer.putc(line, offset + depth - 1, '|', style);
1548 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1549 let extra = if inclusive {
1554 (b_start..b_end + extra).contains(&a_start) ||
1555 (a_start..a_end + extra).contains(&b_start)
1557 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1558 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1561 fn emit_to_destination(rendered_buffer: &[Vec<StyledString>],
1563 dst: &mut Destination,
1564 short_message: bool)
1568 let mut dst = dst.writable();
1570 // In order to prevent error message interleaving, where multiple error lines get intermixed
1571 // when multiple compiler processes error simultaneously, we emit errors with additional
1574 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1575 // the .flush() is called we take the buffer created from the buffered writes and write it at
1576 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1577 // scheme, this buffered approach works and maintains the styling.
1579 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1580 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1581 // enough to output the full error message, then we release.
1582 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1583 for (pos, line) in rendered_buffer.iter().enumerate() {
1585 dst.apply_style(lvl.clone(), part.style)?;
1586 write!(dst, "{}", part.text)?;
1589 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
1597 pub enum Destination {
1598 Terminal(StandardStream),
1599 Buffered(BufferWriter),
1600 // The bool denotes whether we should be emitting ansi color codes or not
1601 Raw(Box<(dyn Write + Send)>, bool),
1604 pub enum WritableDst<'a> {
1605 Terminal(&'a mut StandardStream),
1606 Buffered(&'a mut BufferWriter, Buffer),
1607 Raw(&'a mut (dyn Write + Send)),
1608 ColoredRaw(Ansi<&'a mut (dyn Write + Send)>),
1612 fn from_stderr(color: ColorConfig) -> Destination {
1613 let choice = color.to_color_choice();
1614 // On Windows we'll be performing global synchronization on the entire
1615 // system for emitting rustc errors, so there's no need to buffer
1618 // On non-Windows we rely on the atomicity of `write` to ensure errors
1619 // don't get all jumbled up.
1621 Terminal(StandardStream::stderr(choice))
1623 Buffered(BufferWriter::stderr(choice))
1627 fn writable<'a>(&'a mut self) -> WritableDst<'a> {
1629 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
1630 Destination::Buffered(ref mut t) => {
1631 let buf = t.buffer();
1632 WritableDst::Buffered(t, buf)
1634 Destination::Raw(ref mut t, false) => WritableDst::Raw(t),
1635 Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)),
1640 impl<'a> WritableDst<'a> {
1641 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1642 let mut spec = ColorSpec::new();
1644 Style::LineAndColumn => {}
1645 Style::LineNumber => {
1646 spec.set_bold(true);
1647 spec.set_intense(true);
1649 spec.set_fg(Some(Color::Cyan));
1651 spec.set_fg(Some(Color::Blue));
1654 Style::Quotation => {}
1655 Style::MainHeaderMsg => {
1656 spec.set_bold(true);
1658 spec.set_intense(true)
1659 .set_fg(Some(Color::White));
1662 Style::UnderlinePrimary | Style::LabelPrimary => {
1664 spec.set_bold(true);
1666 Style::UnderlineSecondary |
1667 Style::LabelSecondary => {
1671 spec.set_fg(Some(Color::Cyan));
1673 spec.set_fg(Some(Color::Blue));
1677 Style::NoStyle => {}
1678 Style::Level(lvl) => {
1680 spec.set_bold(true);
1682 Style::Highlight => {
1683 spec.set_bold(true);
1686 self.set_color(&spec)
1689 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
1691 WritableDst::Terminal(ref mut t) => t.set_color(color),
1692 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
1693 WritableDst::ColoredRaw(ref mut t) => t.set_color(color),
1694 WritableDst::Raw(_) => Ok(())
1698 fn reset(&mut self) -> io::Result<()> {
1700 WritableDst::Terminal(ref mut t) => t.reset(),
1701 WritableDst::Buffered(_, ref mut t) => t.reset(),
1702 WritableDst::ColoredRaw(ref mut t) => t.reset(),
1703 WritableDst::Raw(_) => Ok(()),
1708 impl<'a> Write for WritableDst<'a> {
1709 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
1711 WritableDst::Terminal(ref mut t) => t.write(bytes),
1712 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
1713 WritableDst::Raw(ref mut w) => w.write(bytes),
1714 WritableDst::ColoredRaw(ref mut t) => t.write(bytes),
1718 fn flush(&mut self) -> io::Result<()> {
1720 WritableDst::Terminal(ref mut t) => t.flush(),
1721 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
1722 WritableDst::Raw(ref mut w) => w.flush(),
1723 WritableDst::ColoredRaw(ref mut w) => w.flush(),
1728 impl<'a> Drop for WritableDst<'a> {
1729 fn drop(&mut self) {
1731 WritableDst::Buffered(ref mut dst, ref mut buf) => {
1732 drop(dst.print(buf));