1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use self::Destination::*;
13 use syntax_pos::{SourceFile, Span, MultiSpan};
15 use {Level, CodeSuggestion, DiagnosticBuilder, SubDiagnostic, SourceMapperDyn, DiagnosticId};
16 use snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
17 use styled_buffer::StyledBuffer;
19 use rustc_data_structures::fx::FxHashMap;
20 use rustc_data_structures::sync::Lrc;
23 use std::io::prelude::*;
25 use std::cmp::{min, Reverse};
26 use termcolor::{StandardStream, ColorChoice, ColorSpec, BufferWriter};
27 use termcolor::{WriteColor, Color, Buffer};
30 const ANONYMIZED_LINE_NUM: &str = "LL";
32 /// Emitter trait for emitting errors.
34 /// Emit a structured diagnostic.
35 fn emit(&mut self, db: &DiagnosticBuilder);
37 /// Check if should show explanations about "rustc --explain"
38 fn should_show_explain(&self) -> bool {
43 impl Emitter for EmitterWriter {
44 fn emit(&mut self, db: &DiagnosticBuilder) {
45 let mut primary_span = db.span.clone();
46 let mut children = db.children.clone();
47 let mut suggestions: &[_] = &[];
49 if let Some((sugg, rest)) = db.suggestions.split_first() {
51 // don't display multi-suggestions as labels
52 sugg.substitutions.len() == 1 &&
53 // don't display multipart suggestions as labels
54 sugg.substitutions[0].parts.len() == 1 &&
55 // don't display long messages as labels
56 sugg.msg.split_whitespace().count() < 10 &&
57 // don't display multiline suggestions as labels
58 !sugg.substitutions[0].parts[0].snippet.contains('\n') {
59 let substitution = &sugg.substitutions[0].parts[0].snippet.trim();
60 let msg = if substitution.len() == 0 || !sugg.show_code_when_inline {
61 // This substitution is only removal or we explicitly don't want to show the
62 // code inline, don't show it
63 format!("help: {}", sugg.msg)
65 format!("help: {}: `{}`", sugg.msg, substitution)
67 primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg);
69 // if there are multiple suggestions, print them all in full
70 // to be consistent. We could try to figure out if we can
71 // make one (or the first one) inline, but that would give
72 // undue importance to a semi-random suggestion
73 suggestions = &db.suggestions;
77 self.fix_multispans_in_std_macros(&mut primary_span,
79 db.handler.flags.external_macro_backtrace);
81 self.emit_messages_default(&db.level,
89 fn should_show_explain(&self) -> bool {
94 /// maximum number of lines we will print for each error; arbitrary.
95 pub const MAX_HIGHLIGHT_LINES: usize = 6;
96 /// maximum number of suggestions to be shown
98 /// Arbitrary, but taken from trait import suggestion limit
99 pub const MAX_SUGGESTIONS: usize = 4;
101 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
102 pub enum ColorConfig {
109 fn to_color_choice(&self) -> ColorChoice {
111 ColorConfig::Always => {
112 if atty::is(atty::Stream::Stderr) {
115 ColorChoice::AlwaysAnsi
118 ColorConfig::Never => ColorChoice::Never,
119 ColorConfig::Auto if atty::is(atty::Stream::Stderr) => {
122 ColorConfig::Auto => ColorChoice::Never,
127 pub struct EmitterWriter {
129 sm: Option<Lrc<SourceMapperDyn>>,
135 struct FileWithAnnotatedLines {
136 file: Lrc<SourceFile>,
138 multiline_depth: usize,
142 pub fn stderr(color_config: ColorConfig,
143 source_map: Option<Lrc<SourceMapperDyn>>,
147 let dst = Destination::from_stderr(color_config);
157 pub fn new(dst: Box<dyn Write + Send>,
158 source_map: Option<Lrc<SourceMapperDyn>>,
171 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
172 self.ui_testing = ui_testing;
176 fn maybe_anonymized(&self, line_num: usize) -> String {
178 ANONYMIZED_LINE_NUM.to_string()
184 fn preprocess_annotations(&mut self, msp: &MultiSpan) -> Vec<FileWithAnnotatedLines> {
185 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
186 file: Lrc<SourceFile>,
190 for slot in file_vec.iter_mut() {
191 // Look through each of our files for the one we're adding to
192 if slot.file.name == file.name {
193 // See if we already have a line for it
194 for line_slot in &mut slot.lines {
195 if line_slot.line_index == line_index {
196 line_slot.annotations.push(ann);
200 // We don't have a line yet, create one
201 slot.lines.push(Line {
203 annotations: vec![ann],
209 // This is the first time we're seeing the file
210 file_vec.push(FileWithAnnotatedLines {
214 annotations: vec![ann],
220 let mut output = vec![];
221 let mut multiline_annotations = vec![];
223 if let Some(ref sm) = self.sm {
224 for span_label in msp.span_labels() {
225 if span_label.span.is_dummy() {
229 let lo = sm.lookup_char_pos(span_label.span.lo());
230 let mut hi = sm.lookup_char_pos(span_label.span.hi());
232 // Watch out for "empty spans". If we get a span like 6..6, we
233 // want to just display a `^` at 6, so convert that to
234 // 6..7. This is degenerate input, but it's best to degrade
235 // gracefully -- and the parser likes to supply a span like
236 // that for EOF, in particular.
237 if lo.col_display == hi.col_display && lo.line == hi.line {
241 let ann_type = if lo.line != hi.line {
242 let ml = MultilineAnnotation {
246 start_col: lo.col_display,
247 end_col: hi.col_display,
248 is_primary: span_label.is_primary,
249 label: span_label.label.clone(),
251 multiline_annotations.push((lo.file.clone(), ml.clone()));
252 AnnotationType::Multiline(ml)
254 AnnotationType::Singleline
256 let ann = Annotation {
257 start_col: lo.col_display,
258 end_col: hi.col_display,
259 is_primary: span_label.is_primary,
260 label: span_label.label.clone(),
261 annotation_type: ann_type,
264 if !ann.is_multiline() {
265 add_annotation_to_file(&mut output,
273 // Find overlapping multiline annotations, put them at different depths
274 multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end));
275 for item in multiline_annotations.clone() {
277 for item in multiline_annotations.iter_mut() {
278 let ref mut a = item.1;
279 // Move all other multiline annotations overlapping with this one
280 // one level to the right.
282 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
291 let mut max_depth = 0; // max overlapping multiline spans
292 for (file, ann) in multiline_annotations {
293 if ann.depth > max_depth {
294 max_depth = ann.depth;
296 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
297 let middle = min(ann.line_start + 4, ann.line_end);
298 for line in ann.line_start + 1..middle {
299 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
301 if middle < ann.line_end - 1 {
302 for line in ann.line_end - 1..ann.line_end {
303 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
306 add_annotation_to_file(&mut output, file, ann.line_end, ann.as_end());
308 for file_vec in output.iter_mut() {
309 file_vec.multiline_depth = max_depth;
314 fn render_source_line(&self,
315 buffer: &mut StyledBuffer,
316 file: Lrc<SourceFile>,
319 code_offset: usize) -> Vec<(usize, Style)> {
320 if line.line_index == 0 {
324 let source_string = match file.get_line(line.line_index - 1) {
326 None => return Vec::new(),
329 let line_offset = buffer.num_lines();
331 // First create the source line we will highlight.
332 buffer.puts(line_offset, code_offset, &source_string, Style::Quotation);
333 buffer.puts(line_offset,
335 &self.maybe_anonymized(line.line_index),
338 draw_col_separator(buffer, line_offset, width_offset - 2);
340 // Special case when there's only one annotation involved, it is the start of a multiline
341 // span and there's no text at the beginning of the code line. Instead of doing the whole
350 // we simplify the output to:
356 if line.annotations.len() == 1 {
357 if let Some(ref ann) = line.annotations.get(0) {
358 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
359 if source_string.chars()
361 .all(|c| c.is_whitespace()) {
362 let style = if ann.is_primary {
363 Style::UnderlinePrimary
365 Style::UnderlineSecondary
367 buffer.putc(line_offset,
368 width_offset + depth - 1,
371 return vec![(depth, style)];
377 // We want to display like this:
379 // vec.push(vec.pop().unwrap());
380 // --- ^^^ - previous borrow ends here
382 // | error occurs here
383 // previous borrow of `vec` occurs here
385 // But there are some weird edge cases to be aware of:
387 // vec.push(vec.pop().unwrap());
388 // -------- - previous borrow ends here
390 // |this makes no sense
391 // previous borrow of `vec` occurs here
393 // For this reason, we group the lines into "highlight lines"
394 // and "annotations lines", where the highlight lines have the `^`.
396 // Sort the annotations by (start, end col)
397 // The labels are reversed, sort and then reversed again.
398 // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where
399 // the letter signifies the span. Here we are only sorting by the
400 // span and hence, the order of the elements with the same span will
401 // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get
402 // (C1, C2, B1, B2, A1, A2). All the elements with the same span are
403 // still ordered first to last, but all the elements with different
404 // spans are ordered by their spans in last to first order. Last to
405 // first order is important, because the jiggly lines and | are on
406 // the left, so the rightmost span needs to be rendered first,
407 // otherwise the lines would end up needing to go over a message.
409 let mut annotations = line.annotations.clone();
410 annotations.sort_by_key(|a| Reverse(a.start_col));
412 // First, figure out where each label will be positioned.
414 // In the case where you have the following annotations:
416 // vec.push(vec.pop().unwrap());
417 // -------- - previous borrow ends here [C]
419 // |this makes no sense [B]
420 // previous borrow of `vec` occurs here [A]
422 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
424 // We try, when possible, to stick the rightmost annotation at the end
425 // of the highlight line:
427 // vec.push(vec.pop().unwrap());
428 // --- --- - previous borrow ends here
430 // But sometimes that's not possible because one of the other
431 // annotations overlaps it. For example, from the test
432 // `span_overlap_label`, we have the following annotations
433 // (written on distinct lines for clarity):
439 // In this case, we can't stick the rightmost-most label on
440 // the highlight line, or we would get:
447 // which is totally weird. Instead we want:
455 // which is...less weird, at least. In fact, in general, if
456 // the rightmost span overlaps with any other span, we should
457 // use the "hang below" version, so we can at least make it
458 // clear where the span *starts*. There's an exception for this
459 // logic, when the labels do not have a message:
474 let mut annotations_position = vec![];
475 let mut line_len = 0;
477 for (i, annotation) in annotations.iter().enumerate() {
478 for (j, next) in annotations.iter().enumerate() {
479 if overlaps(next, annotation, 0) // This label overlaps with another one and both
480 && annotation.has_label() // take space (they have text and are not
481 && j > i // multiline lines).
482 && p == 0 // We're currently on the first line, move the label one line down
484 // This annotation needs a new line in the output.
489 annotations_position.push((p, annotation));
490 for (j, next) in annotations.iter().enumerate() {
492 let l = if let Some(ref label) = next.label {
497 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
498 // line if they overlap including padding, to
499 // avoid situations like:
506 && annotation.has_label() // Both labels must have some text, otherwise
507 && next.has_label()) // they are not overlapping.
508 // Do not add a new line if this annotation
509 // or the next are vertical line placeholders.
510 || (annotation.takes_space() // If either this or the next annotation is
511 && next.has_label()) // multiline start/end, move it to a new line
512 || (annotation.has_label() // so as not to overlap the orizontal lines.
513 && next.takes_space())
514 || (annotation.takes_space() && next.takes_space())
515 || (overlaps(next, annotation, l)
516 && next.end_col <= annotation.end_col
518 && p == 0) // Avoid #42595.
520 // This annotation needs a new line in the output.
535 // If there are no annotations or the only annotations on this line are
536 // MultilineLine, then there's only code being shown, stop processing.
537 if line.annotations.iter().all(|a| a.is_line()) {
541 // Write the colunmn separator.
543 // After this we will have:
552 for pos in 0..=line_len {
553 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
554 buffer.putc(line_offset + pos + 1,
560 // Write the horizontal lines for multiline annotations
561 // (only the first and last lines need this).
563 // After this we will have:
572 for &(pos, annotation) in &annotations_position {
573 let style = if annotation.is_primary {
574 Style::UnderlinePrimary
576 Style::UnderlineSecondary
579 match annotation.annotation_type {
580 AnnotationType::MultilineStart(depth) |
581 AnnotationType::MultilineEnd(depth) => {
585 width_offset + depth,
586 code_offset + annotation.start_col,
590 buffer.set_style_range(line_offset,
591 code_offset + annotation.start_col,
592 code_offset + annotation.end_col,
594 annotation.is_primary);
600 // Write the vertical lines for labels that are on a different line as the underline.
602 // After this we will have:
611 for &(pos, annotation) in &annotations_position {
612 let style = if annotation.is_primary {
613 Style::UnderlinePrimary
615 Style::UnderlineSecondary
619 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
620 for p in line_offset + 1..=line_offset + pos {
622 code_offset + annotation.start_col,
627 match annotation.annotation_type {
628 AnnotationType::MultilineStart(depth) => {
629 for p in line_offset + pos + 1..line_offset + line_len + 2 {
631 width_offset + depth - 1,
636 AnnotationType::MultilineEnd(depth) => {
637 for p in line_offset..=line_offset + pos {
639 width_offset + depth - 1,
648 // Write the labels on the annotations that actually have a label.
650 // After this we will have:
655 // | something about `foo`
659 for &(pos, annotation) in &annotations_position {
660 let style = if annotation.is_primary {
663 Style::LabelSecondary
665 let (pos, col) = if pos == 0 {
666 (pos + 1, annotation.end_col + 1)
668 (pos + 2, annotation.start_col)
670 if let Some(ref label) = annotation.label {
671 buffer.puts(line_offset + pos,
678 // Sort from biggest span to smallest span so that smaller spans are
679 // represented in the output:
684 // | | something about `foo`
685 // | something about `fn foo()`
686 annotations_position.sort_by(|a, b| {
688 a.1.len().cmp(&b.1.len()).reverse()
691 // Write the underlines.
693 // After this we will have:
698 // | something about `foo`
702 for &(_, annotation) in &annotations_position {
703 let (underline, style) = if annotation.is_primary {
704 ('^', Style::UnderlinePrimary)
706 ('-', Style::UnderlineSecondary)
708 for p in annotation.start_col..annotation.end_col {
709 buffer.putc(line_offset + 1,
715 annotations_position.iter().filter_map(|&(_, annotation)| {
716 match annotation.annotation_type {
717 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
718 let style = if annotation.is_primary {
721 Style::LabelSecondary
728 }).collect::<Vec<_>>()
731 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
733 if let Some(ref sm) = self.sm {
734 for primary_span in msp.primary_spans() {
735 if !primary_span.is_dummy() {
736 let hi = sm.lookup_char_pos(primary_span.hi());
742 if !self.short_message {
743 for span_label in msp.span_labels() {
744 if !span_label.span.is_dummy() {
745 let hi = sm.lookup_char_pos(span_label.span.hi());
756 fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize {
759 let primary = self.get_multispan_max_line_num(span);
760 max = if primary > max { primary } else { max };
762 for sub in children {
763 let sub_result = self.get_multispan_max_line_num(&sub.span);
764 max = if sub_result > max { primary } else { max };
769 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
770 // <*macros>. Since these locations are often difficult to read, we move these Spans from
771 // <*macros> to their corresponding use site.
772 fn fix_multispan_in_std_macros(&mut self,
773 span: &mut MultiSpan,
774 always_backtrace: bool) -> bool {
775 let mut spans_updated = false;
777 if let Some(ref sm) = self.sm {
778 let mut before_after: Vec<(Span, Span)> = vec![];
779 let mut new_labels: Vec<(Span, String)> = vec![];
781 // First, find all the spans in <*macros> and point instead at their use site
782 for sp in span.primary_spans() {
786 let call_sp = sm.call_span_if_macro(*sp);
787 if call_sp != *sp && !always_backtrace {
788 before_after.push((*sp, call_sp));
790 let backtrace_len = sp.macro_backtrace().len();
791 for (i, trace) in sp.macro_backtrace().iter().rev().enumerate() {
792 // Only show macro locations that are local
793 // and display them like a span_note
794 if let Some(def_site) = trace.def_site_span {
795 if def_site.is_dummy() {
798 if always_backtrace {
799 new_labels.push((def_site,
800 format!("in this expansion of `{}`{}",
801 trace.macro_decl_name,
802 if backtrace_len > 2 {
803 // if backtrace_len == 1 it'll be pointed
804 // at by "in this macro invocation"
805 format!(" (#{})", i + 1)
810 // Check to make sure we're not in any <*macros>
811 if !sm.span_to_filename(def_site).is_macros() &&
812 !trace.macro_decl_name.starts_with("desugaring of ") &&
813 !trace.macro_decl_name.starts_with("#[") ||
815 new_labels.push((trace.call_site,
816 format!("in this macro invocation{}",
817 if backtrace_len > 2 && always_backtrace {
818 // only specify order when the macro
819 // backtrace is multiple levels deep
820 format!(" (#{})", i + 1)
824 if !always_backtrace {
831 for (label_span, label_text) in new_labels {
832 span.push_span_label(label_span, label_text);
834 for sp_label in span.span_labels() {
835 if sp_label.span.is_dummy() {
838 if sm.span_to_filename(sp_label.span.clone()).is_macros() &&
841 let v = sp_label.span.macro_backtrace();
842 if let Some(use_site) = v.last() {
843 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
847 // After we have them, make sure we replace these 'bad' def sites with their use sites
848 for (before, after) in before_after {
849 span.replace(before, after);
850 spans_updated = true;
857 // This does a small "fix" for multispans by looking to see if it can find any that
858 // point directly at <*macros>. Since these are often difficult to read, this
859 // will change the span to point at the use site.
860 fn fix_multispans_in_std_macros(&mut self,
861 span: &mut MultiSpan,
862 children: &mut Vec<SubDiagnostic>,
864 let mut spans_updated = self.fix_multispan_in_std_macros(span, backtrace);
865 for child in children.iter_mut() {
866 spans_updated |= self.fix_multispan_in_std_macros(&mut child.span, backtrace);
869 children.push(SubDiagnostic {
872 ("this error originates in a macro outside of the current crate \
873 (in Nightly builds, run with -Z external-macro-backtrace \
874 for more info)".to_string(),
877 span: MultiSpan::new(),
883 /// Add a left margin to every line but the first, given a padding length and the label being
884 /// displayed, keeping the provided highlighting.
885 fn msg_to_buffer(&self,
886 buffer: &mut StyledBuffer,
887 msg: &[(String, Style)],
890 override_style: Option<Style>) {
892 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
905 // | | length of label
907 // `max_line_num_len`
908 let padding = " ".repeat(padding + label.len() + 5);
910 /// Return whether `style`, or the override if present and the style is `NoStyle`.
911 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
912 if let Some(o) = override_style {
913 if style == Style::NoStyle {
920 let mut line_number = 0;
922 // Provided the following diagnostic message:
926 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
927 // ("looks", Style::Highlight),
928 // ("with\nvery ", Style::NoStyle),
929 // ("weird", Style::Highlight),
930 // (" formats\n", Style::NoStyle),
931 // ("see?", Style::Highlight),
934 // the expected output on a note is (* surround the highlighted text)
936 // = note: highlighted multiline
938 // see how it *looks* with
939 // very *weird* formats
941 for &(ref text, ref style) in msg.iter() {
942 let lines = text.split('\n').collect::<Vec<_>>();
944 for (i, line) in lines.iter().enumerate() {
947 buffer.append(line_number, &padding, Style::NoStyle);
949 buffer.append(line_number, line, style_or_override(*style, override_style));
952 buffer.append(line_number, text, style_or_override(*style, override_style));
957 fn emit_message_default(&mut self,
959 msg: &[(String, Style)],
960 code: &Option<DiagnosticId>,
962 max_line_num_len: usize,
965 let mut buffer = StyledBuffer::new();
966 let header_style = if is_secondary {
972 if msp.primary_spans().is_empty() && msp.span_labels().is_empty() && is_secondary
973 && !self.short_message {
974 // This is a secondary message with no span info
975 for _ in 0..max_line_num_len {
976 buffer.prepend(0, " ", Style::NoStyle);
978 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
979 let level_str = level.to_string();
980 if !level_str.is_empty() {
981 buffer.append(0, &level_str, Style::MainHeaderMsg);
982 buffer.append(0, ": ", Style::NoStyle);
984 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
986 let level_str = level.to_string();
987 if !level_str.is_empty() {
988 buffer.append(0, &level_str, Style::Level(level.clone()));
990 // only render error codes, not lint codes
991 if let Some(DiagnosticId::Error(ref code)) = *code {
992 buffer.append(0, "[", Style::Level(level.clone()));
993 buffer.append(0, &code, Style::Level(level.clone()));
994 buffer.append(0, "]", Style::Level(level.clone()));
996 if !level_str.is_empty() {
997 buffer.append(0, ": ", header_style);
999 for &(ref text, _) in msg.iter() {
1000 buffer.append(0, text, header_style);
1004 // Preprocess all the annotations so that they are grouped by file and by line number
1005 // This helps us quickly iterate over the whole message (including secondary file spans)
1006 let mut annotated_files = self.preprocess_annotations(msp);
1008 // Make sure our primary file comes first
1009 let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) =
1010 (self.sm.as_ref(), msp.primary_span().as_ref()) {
1011 if !primary_span.is_dummy() {
1012 (sm.lookup_char_pos(primary_span.lo()), sm)
1014 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1018 // If we don't have span information, emit and exit
1019 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1023 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
1024 annotated_files.swap(0, pos);
1027 // Print out the annotate source lines that correspond with the error
1028 for annotated_file in annotated_files {
1029 // we can't annotate anything if the source is unavailable.
1030 if !sm.ensure_source_file_source_present(annotated_file.file.clone()) {
1034 // print out the span location and spacer before we print the annotated source
1035 // to do this, we need to know if this span will be primary
1036 let is_primary = primary_lo.file.name == annotated_file.file.name;
1038 let loc = primary_lo.clone();
1039 if !self.short_message {
1040 // remember where we are in the output buffer for easy reference
1041 let buffer_msg_line_offset = buffer.num_lines();
1043 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
1044 buffer.append(buffer_msg_line_offset,
1045 &format!("{}:{}:{}",
1047 sm.doctest_offset_line(&loc.file.name, loc.line),
1049 Style::LineAndColumn);
1050 for _ in 0..max_line_num_len {
1051 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
1055 &format!("{}:{}:{}: ",
1057 sm.doctest_offset_line(&loc.file.name, loc.line),
1059 Style::LineAndColumn);
1061 } else if !self.short_message {
1062 // remember where we are in the output buffer for easy reference
1063 let buffer_msg_line_offset = buffer.num_lines();
1066 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
1068 // Then, the secondary file indicator
1069 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
1070 let loc = if let Some(first_line) = annotated_file.lines.first() {
1071 let col = if let Some(first_annotation) = first_line.annotations.first() {
1072 format!(":{}", first_annotation.start_col + 1)
1077 annotated_file.file.name,
1078 sm.doctest_offset_line(
1079 &annotated_file.file.name, first_line.line_index),
1082 annotated_file.file.name.to_string()
1084 buffer.append(buffer_msg_line_offset + 1,
1086 Style::LineAndColumn);
1087 for _ in 0..max_line_num_len {
1088 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
1092 if !self.short_message {
1093 // Put in the spacer between the location and annotated source
1094 let buffer_msg_line_offset = buffer.num_lines();
1095 draw_col_separator_no_space(&mut buffer,
1096 buffer_msg_line_offset,
1097 max_line_num_len + 1);
1099 // Contains the vertical lines' positions for active multiline annotations
1100 let mut multilines = FxHashMap::default();
1102 // Next, output the annotate source for this file
1103 for line_idx in 0..annotated_file.lines.len() {
1104 let previous_buffer_line = buffer.num_lines();
1106 let width_offset = 3 + max_line_num_len;
1107 let code_offset = if annotated_file.multiline_depth == 0 {
1110 width_offset + annotated_file.multiline_depth + 1
1113 let depths = self.render_source_line(&mut buffer,
1114 annotated_file.file.clone(),
1115 &annotated_file.lines[line_idx],
1119 let mut to_add = FxHashMap::default();
1121 for (depth, style) in depths {
1122 if multilines.get(&depth).is_some() {
1123 multilines.remove(&depth);
1125 to_add.insert(depth, style);
1129 // Set the multiline annotation vertical lines to the left of
1130 // the code in this line.
1131 for (depth, style) in &multilines {
1132 for line in previous_buffer_line..buffer.num_lines() {
1133 draw_multiline_line(&mut buffer,
1140 // check to see if we need to print out or elide lines that come between
1141 // this annotated line and the next one.
1142 if line_idx < (annotated_file.lines.len() - 1) {
1143 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
1144 annotated_file.lines[line_idx].line_index;
1145 if line_idx_delta > 2 {
1146 let last_buffer_line_num = buffer.num_lines();
1147 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1149 // Set the multiline annotation vertical lines on `...` bridging line.
1150 for (depth, style) in &multilines {
1151 draw_multiline_line(&mut buffer,
1152 last_buffer_line_num,
1157 } else if line_idx_delta == 2 {
1158 let unannotated_line = annotated_file.file
1159 .get_line(annotated_file.lines[line_idx].line_index)
1160 .unwrap_or_else(|| Cow::from(""));
1162 let last_buffer_line_num = buffer.num_lines();
1164 buffer.puts(last_buffer_line_num,
1166 &self.maybe_anonymized(annotated_file.lines[line_idx + 1]
1169 draw_col_separator(&mut buffer,
1170 last_buffer_line_num,
1171 1 + max_line_num_len);
1172 buffer.puts(last_buffer_line_num,
1177 for (depth, style) in &multilines {
1178 draw_multiline_line(&mut buffer,
1179 last_buffer_line_num,
1187 multilines.extend(&to_add);
1192 // final step: take our styled buffer, render it, then output it
1193 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1199 fn emit_suggestion_default(&mut self,
1200 suggestion: &CodeSuggestion,
1202 max_line_num_len: usize)
1204 if let Some(ref sm) = self.sm {
1205 let mut buffer = StyledBuffer::new();
1207 // Render the suggestion message
1208 let level_str = level.to_string();
1209 if !level_str.is_empty() {
1210 buffer.append(0, &level_str, Style::Level(level.clone()));
1211 buffer.append(0, ": ", Style::HeaderMsg);
1213 self.msg_to_buffer(&mut buffer,
1214 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1217 Some(Style::HeaderMsg));
1219 // Render the replacements for each suggestion
1220 let suggestions = suggestion.splice_lines(&**sm);
1222 let mut row_num = 2;
1223 for &(ref complete, ref parts) in suggestions.iter().take(MAX_SUGGESTIONS) {
1224 // Only show underline if the suggestion spans a single line and doesn't cover the
1225 // entirety of the code output. If you have multiple replacements in the same line
1226 // of code, show the underline.
1227 let show_underline = !(parts.len() == 1
1228 && parts[0].snippet.trim() == complete.trim())
1229 && complete.lines().count() == 1;
1231 let lines = sm.span_to_lines(parts[0].span).unwrap();
1233 assert!(!lines.lines.is_empty());
1235 let line_start = sm.lookup_char_pos(parts[0].span.lo()).line;
1236 draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
1237 let mut line_pos = 0;
1238 let mut lines = complete.lines();
1239 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1240 // Print the span column to avoid confusion
1241 buffer.puts(row_num,
1243 &self.maybe_anonymized(line_start + line_pos),
1245 // print the suggestion
1246 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1247 buffer.append(row_num, line, Style::NoStyle);
1252 // This offset and the ones below need to be signed to account for replacement code
1253 // that is shorter than the original code.
1254 let mut offset: isize = 0;
1255 // Only show an underline in the suggestions if the suggestion is not the
1256 // entirety of the code being shown and the displayed code is not multiline.
1258 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1260 let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
1261 let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
1263 // Do not underline the leading...
1264 let start = part.snippet.len()
1265 .saturating_sub(part.snippet.trim_start().len());
1266 // ...or trailing spaces. Account for substitutions containing unicode
1268 let sub_len = part.snippet.trim().chars().fold(0, |acc, ch| {
1269 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0)
1272 let underline_start = (span_start_pos + start) as isize + offset;
1273 let underline_end = (span_start_pos + start + sub_len) as isize + offset;
1274 for p in underline_start..underline_end {
1275 buffer.putc(row_num,
1276 max_line_num_len + 3 + p as usize,
1278 Style::UnderlinePrimary);
1280 // underline removals too
1281 if underline_start == underline_end {
1282 for p in underline_start-1..underline_start+1 {
1283 buffer.putc(row_num,
1284 max_line_num_len + 3 + p as usize,
1286 Style::UnderlineSecondary);
1290 // length of the code after substitution
1291 let full_sub_len = part.snippet.chars().fold(0, |acc, ch| {
1292 acc + unicode_width::UnicodeWidthChar::width(ch).unwrap_or(0) as isize
1295 // length of the code to be substituted
1296 let snippet_len = span_end_pos as isize - span_start_pos as isize;
1297 // For multiple substitutions, use the position *after* the previous
1298 // substitutions have happened.
1299 offset += full_sub_len - snippet_len;
1304 // if we elided some lines, add an ellipsis
1305 if lines.next().is_some() {
1306 buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
1307 } else if !show_underline {
1308 draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1);
1312 if suggestions.len() > MAX_SUGGESTIONS {
1313 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1314 buffer.puts(row_num, 0, &msg, Style::NoStyle);
1316 emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?;
1321 fn emit_messages_default(&mut self,
1323 message: &[(String, Style)],
1324 code: &Option<DiagnosticId>,
1326 children: &[SubDiagnostic],
1327 suggestions: &[CodeSuggestion]) {
1328 let max_line_num_len = if self.ui_testing {
1329 ANONYMIZED_LINE_NUM.len()
1331 self.get_max_line_num(span, children).to_string().len()
1334 match self.emit_message_default(span,
1341 if !children.is_empty() {
1342 let mut buffer = StyledBuffer::new();
1343 if !self.short_message {
1344 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1346 match emit_to_destination(&buffer.render(), level, &mut self.dst,
1347 self.short_message) {
1349 Err(e) => panic!("failed to emit error: {}", e)
1352 if !self.short_message {
1353 for child in children {
1354 let span = child.render_span.as_ref().unwrap_or(&child.span);
1355 match self.emit_message_default(&span,
1356 &child.styled_message(),
1361 Err(e) => panic!("failed to emit error: {}", e),
1365 for sugg in suggestions {
1366 match self.emit_suggestion_default(sugg,
1369 Err(e) => panic!("failed to emit error: {}", e),
1375 Err(e) => panic!("failed to emit error: {}", e),
1378 let mut dst = self.dst.writable();
1379 match write!(dst, "\n") {
1380 Err(e) => panic!("failed to emit error: {}", e),
1383 Err(e) => panic!("failed to emit error: {}", e),
1391 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1392 buffer.puts(line, col, "| ", Style::LineNumber);
1395 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1396 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1399 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1403 buffer.putc(line, col, '|', style);
1406 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1407 col_from: usize, col_to: usize, style: Style) {
1408 for col in col_from..col_to {
1409 buffer.putc(line, col, symbol, style);
1413 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1414 buffer.puts(line, col, "= ", Style::LineNumber);
1417 fn draw_multiline_line(buffer: &mut StyledBuffer,
1423 buffer.putc(line, offset + depth - 1, '|', style);
1426 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1427 let extra = if inclusive {
1432 (b_start..b_end + extra).contains(&a_start) ||
1433 (a_start..a_end + extra).contains(&b_start)
1435 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1436 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1439 fn emit_to_destination(rendered_buffer: &[Vec<StyledString>],
1441 dst: &mut Destination,
1442 short_message: bool)
1446 let mut dst = dst.writable();
1448 // In order to prevent error message interleaving, where multiple error lines get intermixed
1449 // when multiple compiler processes error simultaneously, we emit errors with additional
1452 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1453 // the .flush() is called we take the buffer created from the buffered writes and write it at
1454 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1455 // scheme, this buffered approach works and maintains the styling.
1457 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1458 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1459 // enough to output the full error message, then we release.
1460 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1461 for (pos, line) in rendered_buffer.iter().enumerate() {
1463 dst.apply_style(lvl.clone(), part.style)?;
1464 write!(dst, "{}", part.text)?;
1467 if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) {
1475 pub enum Destination {
1476 Terminal(StandardStream),
1477 Buffered(BufferWriter),
1478 Raw(Box<dyn Write + Send>),
1481 pub enum WritableDst<'a> {
1482 Terminal(&'a mut StandardStream),
1483 Buffered(&'a mut BufferWriter, Buffer),
1484 Raw(&'a mut Box<dyn Write + Send>),
1488 fn from_stderr(color: ColorConfig) -> Destination {
1489 let choice = color.to_color_choice();
1490 // On Windows we'll be performing global synchronization on the entire
1491 // system for emitting rustc errors, so there's no need to buffer
1494 // On non-Windows we rely on the atomicity of `write` to ensure errors
1495 // don't get all jumbled up.
1497 Terminal(StandardStream::stderr(choice))
1499 Buffered(BufferWriter::stderr(choice))
1503 fn writable<'a>(&'a mut self) -> WritableDst<'a> {
1505 Destination::Terminal(ref mut t) => WritableDst::Terminal(t),
1506 Destination::Buffered(ref mut t) => {
1507 let buf = t.buffer();
1508 WritableDst::Buffered(t, buf)
1510 Destination::Raw(ref mut t) => WritableDst::Raw(t),
1515 impl<'a> WritableDst<'a> {
1516 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1517 let mut spec = ColorSpec::new();
1519 Style::LineAndColumn => {}
1520 Style::LineNumber => {
1521 spec.set_bold(true);
1522 spec.set_intense(true);
1524 spec.set_fg(Some(Color::Cyan));
1526 spec.set_fg(Some(Color::Blue));
1529 Style::Quotation => {}
1530 Style::OldSchoolNoteText | Style::MainHeaderMsg => {
1531 spec.set_bold(true);
1533 spec.set_intense(true)
1534 .set_fg(Some(Color::White));
1537 Style::UnderlinePrimary | Style::LabelPrimary => {
1539 spec.set_bold(true);
1541 Style::UnderlineSecondary |
1542 Style::LabelSecondary => {
1546 spec.set_fg(Some(Color::Cyan));
1548 spec.set_fg(Some(Color::Blue));
1552 Style::NoStyle => {}
1553 Style::Level(lvl) => {
1555 spec.set_bold(true);
1557 Style::Highlight => {
1558 spec.set_bold(true);
1561 self.set_color(&spec)
1564 fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> {
1566 WritableDst::Terminal(ref mut t) => t.set_color(color),
1567 WritableDst::Buffered(_, ref mut t) => t.set_color(color),
1568 WritableDst::Raw(_) => Ok(())
1572 fn reset(&mut self) -> io::Result<()> {
1574 WritableDst::Terminal(ref mut t) => t.reset(),
1575 WritableDst::Buffered(_, ref mut t) => t.reset(),
1576 WritableDst::Raw(_) => Ok(()),
1581 impl<'a> Write for WritableDst<'a> {
1582 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
1584 WritableDst::Terminal(ref mut t) => t.write(bytes),
1585 WritableDst::Buffered(_, ref mut buf) => buf.write(bytes),
1586 WritableDst::Raw(ref mut w) => w.write(bytes),
1590 fn flush(&mut self) -> io::Result<()> {
1592 WritableDst::Terminal(ref mut t) => t.flush(),
1593 WritableDst::Buffered(_, ref mut buf) => buf.flush(),
1594 WritableDst::Raw(ref mut w) => w.flush(),
1599 impl<'a> Drop for WritableDst<'a> {
1600 fn drop(&mut self) {
1602 WritableDst::Buffered(ref mut dst, ref mut buf) => {
1603 drop(dst.print(buf));