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::{DUMMY_SP, FileMap, Span, MultiSpan, CharPos};
15 use {Level, CodeSuggestion, DiagnosticBuilder, SubDiagnostic, CodeMapper};
17 use snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
18 use styled_buffer::StyledBuffer;
20 use std::io::prelude::*;
24 use std::collections::HashMap;
27 /// Emitter trait for emitting errors.
29 /// Emit a structured diagnostic.
30 fn emit(&mut self, db: &DiagnosticBuilder);
33 impl Emitter for EmitterWriter {
34 fn emit(&mut self, db: &DiagnosticBuilder) {
35 let mut primary_span = db.span.clone();
36 let mut children = db.children.clone();
38 if let Some((sugg, rest)) = db.suggestions.split_first() {
40 // don't display multipart suggestions as labels
41 sugg.substitution_parts.len() == 1 &&
42 // don't display multi-suggestions as labels
43 sugg.substitutions() == 1 &&
44 // don't display long messages as labels
45 sugg.msg.split_whitespace().count() < 10 &&
46 // don't display multiline suggestions as labels
47 sugg.substitution_parts[0].substitutions[0].find('\n').is_none() {
48 let substitution = &sugg.substitution_parts[0].substitutions[0];
49 let msg = format!("help: {} `{}`", sugg.msg, substitution);
50 primary_span.push_span_label(sugg.substitution_spans().next().unwrap(), msg);
52 // if there are multiple suggestions, print them all in full
53 // to be consistent. We could try to figure out if we can
54 // make one (or the first one) inline, but that would give
55 // undue importance to a semi-random suggestion
56 for sugg in &db.suggestions {
57 children.push(SubDiagnostic {
60 span: MultiSpan::new(),
61 render_span: Some(Suggestion(sugg.clone())),
67 self.fix_multispans_in_std_macros(&mut primary_span, &mut children);
68 self.emit_messages_default(&db.level,
76 /// maximum number of lines we will print for each error; arbitrary.
77 pub const MAX_HIGHLIGHT_LINES: usize = 6;
78 /// maximum number of suggestions to be shown
80 /// Arbitrary, but taken from trait import suggestion limit
81 pub const MAX_SUGGESTIONS: usize = 4;
83 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
84 pub enum ColorConfig {
91 fn use_color(&self) -> bool {
93 ColorConfig::Always => true,
94 ColorConfig::Never => false,
95 ColorConfig::Auto => stderr_isatty(),
100 pub struct EmitterWriter {
102 cm: Option<Rc<CodeMapper>>,
105 struct FileWithAnnotatedLines {
108 multiline_depth: usize,
112 pub fn stderr(color_config: ColorConfig, code_map: Option<Rc<CodeMapper>>) -> EmitterWriter {
113 if color_config.use_color() {
114 let dst = Destination::from_stderr();
121 dst: Raw(Box::new(io::stderr())),
127 pub fn new(dst: Box<Write + Send>, code_map: Option<Rc<CodeMapper>>) -> EmitterWriter {
134 fn preprocess_annotations(&self, msp: &MultiSpan) -> Vec<FileWithAnnotatedLines> {
135 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
140 for slot in file_vec.iter_mut() {
141 // Look through each of our files for the one we're adding to
142 if slot.file.name == file.name {
143 // See if we already have a line for it
144 for line_slot in &mut slot.lines {
145 if line_slot.line_index == line_index {
146 line_slot.annotations.push(ann);
150 // We don't have a line yet, create one
151 slot.lines.push(Line {
152 line_index: line_index,
153 annotations: vec![ann],
159 // This is the first time we're seeing the file
160 file_vec.push(FileWithAnnotatedLines {
163 line_index: line_index,
164 annotations: vec![ann],
170 let mut output = vec![];
171 let mut multiline_annotations = vec![];
173 if let Some(ref cm) = self.cm {
174 for span_label in msp.span_labels() {
175 if span_label.span == DUMMY_SP {
178 let lo = cm.lookup_char_pos(span_label.span.lo);
179 let mut hi = cm.lookup_char_pos(span_label.span.hi);
181 // Watch out for "empty spans". If we get a span like 6..6, we
182 // want to just display a `^` at 6, so convert that to
183 // 6..7. This is degenerate input, but it's best to degrade
184 // gracefully -- and the parser likes to supply a span like
185 // that for EOF, in particular.
186 if lo.col == hi.col && lo.line == hi.line {
187 hi.col = CharPos(lo.col.0 + 1);
190 let ann_type = if lo.line != hi.line {
191 let ml = MultilineAnnotation {
197 is_primary: span_label.is_primary,
198 label: span_label.label.clone(),
200 multiline_annotations.push((lo.file.clone(), ml.clone()));
201 AnnotationType::Multiline(ml)
203 AnnotationType::Singleline
205 let ann = Annotation {
208 is_primary: span_label.is_primary,
209 label: span_label.label.clone(),
210 annotation_type: ann_type,
213 if !ann.is_multiline() {
214 add_annotation_to_file(&mut output,
222 // Find overlapping multiline annotations, put them at different depths
223 multiline_annotations.sort_by(|a, b| {
224 (a.1.line_start, a.1.line_end).cmp(&(b.1.line_start, b.1.line_end))
226 for item in multiline_annotations.clone() {
228 for item in multiline_annotations.iter_mut() {
229 let ref mut a = item.1;
230 // Move all other multiline annotations overlapping with this one
231 // one level to the right.
233 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
242 let mut max_depth = 0; // max overlapping multiline spans
243 for (file, ann) in multiline_annotations {
244 if ann.depth > max_depth {
245 max_depth = ann.depth;
247 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
248 let middle = min(ann.line_start + 4, ann.line_end);
249 for line in ann.line_start + 1..middle {
250 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
252 if middle < ann.line_end - 1 {
253 for line in ann.line_end - 1..ann.line_end {
254 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
257 add_annotation_to_file(&mut output, file, ann.line_end, ann.as_end());
259 for file_vec in output.iter_mut() {
260 file_vec.multiline_depth = max_depth;
265 fn render_source_line(&self,
266 buffer: &mut StyledBuffer,
270 code_offset: usize) -> Vec<(usize, Style)> {
271 let source_string = match file.get_line(line.line_index - 1) {
273 None => return Vec::new(),
276 let line_offset = buffer.num_lines();
278 // First create the source line we will highlight.
279 buffer.puts(line_offset, code_offset, &source_string, Style::Quotation);
280 buffer.puts(line_offset,
282 &(line.line_index.to_string()),
285 draw_col_separator(buffer, line_offset, width_offset - 2);
287 // Special case when there's only one annotation involved, it is the start of a multiline
288 // span and there's no text at the beginning of the code line. Instead of doing the whole
297 // we simplify the output to:
303 if line.annotations.len() == 1 {
304 if let Some(ref ann) = line.annotations.get(0) {
305 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
306 if source_string[0..ann.start_col].trim() == "" {
307 let style = if ann.is_primary {
308 Style::UnderlinePrimary
310 Style::UnderlineSecondary
312 buffer.putc(line_offset,
313 width_offset + depth - 1,
316 return vec![(depth, style)];
322 // We want to display like this:
324 // vec.push(vec.pop().unwrap());
325 // --- ^^^ - previous borrow ends here
327 // | error occurs here
328 // previous borrow of `vec` occurs here
330 // But there are some weird edge cases to be aware of:
332 // vec.push(vec.pop().unwrap());
333 // -------- - previous borrow ends here
335 // |this makes no sense
336 // previous borrow of `vec` occurs here
338 // For this reason, we group the lines into "highlight lines"
339 // and "annotations lines", where the highlight lines have the `^`.
341 // Sort the annotations by (start, end col)
342 let mut annotations = line.annotations.clone();
344 annotations.reverse();
346 // First, figure out where each label will be positioned.
348 // In the case where you have the following annotations:
350 // vec.push(vec.pop().unwrap());
351 // -------- - previous borrow ends here [C]
353 // |this makes no sense [B]
354 // previous borrow of `vec` occurs here [A]
356 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
358 // We try, when possible, to stick the rightmost annotation at the end
359 // of the highlight line:
361 // vec.push(vec.pop().unwrap());
362 // --- --- - previous borrow ends here
364 // But sometimes that's not possible because one of the other
365 // annotations overlaps it. For example, from the test
366 // `span_overlap_label`, we have the following annotations
367 // (written on distinct lines for clarity):
373 // In this case, we can't stick the rightmost-most label on
374 // the highlight line, or we would get:
381 // which is totally weird. Instead we want:
389 // which is...less weird, at least. In fact, in general, if
390 // the rightmost span overlaps with any other span, we should
391 // use the "hang below" version, so we can at least make it
392 // clear where the span *starts*. There's an exception for this
393 // logic, when the labels do not have a message:
408 let mut annotations_position = vec![];
409 let mut line_len = 0;
411 for (i, annotation) in annotations.iter().enumerate() {
412 for (j, next) in annotations.iter().enumerate() {
413 if overlaps(next, annotation, 0) // This label overlaps with another one and both
414 && annotation.has_label() // take space (they have text and are not
415 && j > i // multiline lines).
416 && p == 0 // We're currently on the first line, move the label one line down
418 // This annotation needs a new line in the output.
423 annotations_position.push((p, annotation));
424 for (j, next) in annotations.iter().enumerate() {
426 let l = if let Some(ref label) = next.label {
431 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
432 // line if they overlap including padding, to
433 // avoid situations like:
440 && annotation.has_label() // Both labels must have some text, otherwise
441 && next.has_label()) // they are not overlapping.
442 // Do not add a new line if this annotation
443 // or the next are vertical line placeholders.
444 || (annotation.takes_space() // If either this or the next annotation is
445 && next.has_label()) // multiline start/end, move it to a new line
446 || (annotation.has_label() // so as not to overlap the orizontal lines.
447 && next.takes_space())
448 || (annotation.takes_space() && next.takes_space())
449 || (overlaps(next, annotation, l)
450 && next.end_col <= annotation.end_col
452 && p == 0) // Avoid #42595.
454 // This annotation needs a new line in the output.
469 // If there are no annotations or the only annotations on this line are
470 // MultilineLine, then there's only code being shown, stop processing.
471 if line.annotations.is_empty() || line.annotations.iter()
472 .filter(|a| !a.is_line()).collect::<Vec<_>>().len() == 0
477 // Write the colunmn separator.
479 // After this we will have:
488 for pos in 0..line_len + 1 {
489 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
490 buffer.putc(line_offset + pos + 1,
496 // Write the horizontal lines for multiline annotations
497 // (only the first and last lines need this).
499 // After this we will have:
508 for &(pos, annotation) in &annotations_position {
509 let style = if annotation.is_primary {
510 Style::UnderlinePrimary
512 Style::UnderlineSecondary
515 match annotation.annotation_type {
516 AnnotationType::MultilineStart(depth) |
517 AnnotationType::MultilineEnd(depth) => {
521 width_offset + depth,
522 code_offset + annotation.start_col,
529 // Write the vertical lines for labels that are on a different line as the underline.
531 // After this we will have:
540 for &(pos, annotation) in &annotations_position {
541 let style = if annotation.is_primary {
542 Style::UnderlinePrimary
544 Style::UnderlineSecondary
548 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
549 for p in line_offset + 1..line_offset + pos + 1 {
551 code_offset + annotation.start_col,
556 match annotation.annotation_type {
557 AnnotationType::MultilineStart(depth) => {
558 for p in line_offset + pos + 1..line_offset + line_len + 2 {
560 width_offset + depth - 1,
565 AnnotationType::MultilineEnd(depth) => {
566 for p in line_offset..line_offset + pos + 1 {
568 width_offset + depth - 1,
577 // Write the labels on the annotations that actually have a label.
579 // After this we will have:
584 // | something about `foo`
588 for &(pos, annotation) in &annotations_position {
589 let style = if annotation.is_primary {
592 Style::LabelSecondary
594 let (pos, col) = if pos == 0 {
595 (pos + 1, annotation.end_col + 1)
597 (pos + 2, annotation.start_col)
599 if let Some(ref label) = annotation.label {
600 buffer.puts(line_offset + pos,
607 // Sort from biggest span to smallest span so that smaller spans are
608 // represented in the output:
613 // | | something about `foo`
614 // | something about `fn foo()`
615 annotations_position.sort_by(|a, b| {
617 a.1.len().cmp(&b.1.len()).reverse()
620 // Write the underlines.
622 // After this we will have:
627 // | something about `foo`
631 for &(_, annotation) in &annotations_position {
632 let (underline, style) = if annotation.is_primary {
633 ('^', Style::UnderlinePrimary)
635 ('-', Style::UnderlineSecondary)
637 for p in annotation.start_col..annotation.end_col {
638 buffer.putc(line_offset + 1,
644 annotations_position.iter().filter_map(|&(_, annotation)| {
645 match annotation.annotation_type {
646 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
647 let style = if annotation.is_primary {
650 Style::LabelSecondary
657 }).collect::<Vec<_>>()
660 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
662 if let Some(ref cm) = self.cm {
663 for primary_span in msp.primary_spans() {
664 if primary_span != &DUMMY_SP {
665 let hi = cm.lookup_char_pos(primary_span.hi);
671 for span_label in msp.span_labels() {
672 if span_label.span != DUMMY_SP {
673 let hi = cm.lookup_char_pos(span_label.span.hi);
683 fn get_max_line_num(&mut self, span: &MultiSpan, children: &Vec<SubDiagnostic>) -> usize {
686 let primary = self.get_multispan_max_line_num(span);
687 max = if primary > max { primary } else { max };
689 for sub in children {
690 let sub_result = self.get_multispan_max_line_num(&sub.span);
691 max = if sub_result > max { primary } else { max };
696 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
697 // <*macros>. Since these locations are often difficult to read, we move these Spans from
698 // <*macros> to their corresponding use site.
699 fn fix_multispan_in_std_macros(&mut self, span: &mut MultiSpan) -> bool {
700 let mut spans_updated = false;
702 if let Some(ref cm) = self.cm {
703 let mut before_after: Vec<(Span, Span)> = vec![];
704 let mut new_labels: Vec<(Span, String)> = vec![];
706 // First, find all the spans in <*macros> and point instead at their use site
707 for sp in span.primary_spans() {
711 let call_sp = cm.call_span_if_macro(*sp);
713 before_after.push((sp.clone(), call_sp));
715 for trace in sp.macro_backtrace().iter().rev() {
716 // Only show macro locations that are local
717 // and display them like a span_note
718 if let Some(def_site) = trace.def_site_span {
719 if def_site == DUMMY_SP {
722 // Check to make sure we're not in any <*macros>
723 if !cm.span_to_filename(def_site).contains("macros>") &&
724 !trace.macro_decl_name.starts_with("#[") {
725 new_labels.push((trace.call_site,
726 "in this macro invocation".to_string()));
732 for (label_span, label_text) in new_labels {
733 span.push_span_label(label_span, label_text);
735 for sp_label in span.span_labels() {
736 if sp_label.span == DUMMY_SP {
739 if cm.span_to_filename(sp_label.span.clone()).contains("macros>") {
740 let v = sp_label.span.macro_backtrace();
741 if let Some(use_site) = v.last() {
742 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
746 // After we have them, make sure we replace these 'bad' def sites with their use sites
747 for (before, after) in before_after {
748 span.replace(before, after);
749 spans_updated = true;
756 // This does a small "fix" for multispans by looking to see if it can find any that
757 // point directly at <*macros>. Since these are often difficult to read, this
758 // will change the span to point at the use site.
759 fn fix_multispans_in_std_macros(&mut self,
760 span: &mut MultiSpan,
761 children: &mut Vec<SubDiagnostic>) {
762 let mut spans_updated = self.fix_multispan_in_std_macros(span);
763 for child in children.iter_mut() {
764 spans_updated |= self.fix_multispan_in_std_macros(&mut child.span);
767 children.push(SubDiagnostic {
769 message: vec![("this error originates in a macro outside of the current crate"
770 .to_string(), Style::NoStyle)],
771 span: MultiSpan::new(),
777 /// Add a left margin to every line but the first, given a padding length and the label being
778 /// displayed, keeping the provided highlighting.
779 fn msg_to_buffer(&self,
780 buffer: &mut StyledBuffer,
781 msg: &[(String, Style)],
784 override_style: Option<Style>) {
786 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
799 // | | length of label
801 // `max_line_num_len`
802 let padding = (0..padding + label.len() + 5)
804 .collect::<String>();
806 /// Return wether `style`, or the override if present and the style is `NoStyle`.
807 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
808 if let Some(o) = override_style {
809 if style == Style::NoStyle {
816 let mut line_number = 0;
818 // Provided the following diagnostic message:
822 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
823 // ("looks", Style::Highlight),
824 // ("with\nvery ", Style::NoStyle),
825 // ("weird", Style::Highlight),
826 // (" formats\n", Style::NoStyle),
827 // ("see?", Style::Highlight),
830 // the expected output on a note is (* surround the highlighted text)
832 // = note: highlighted multiline
834 // see how it *looks* with
835 // very *weird* formats
837 for &(ref text, ref style) in msg.iter() {
838 let lines = text.split('\n').collect::<Vec<_>>();
840 for (i, line) in lines.iter().enumerate() {
843 buffer.append(line_number, &padding, Style::NoStyle);
845 buffer.append(line_number, line, style_or_override(*style, override_style));
848 buffer.append(line_number, text, style_or_override(*style, override_style));
853 fn emit_message_default(&mut self,
855 msg: &Vec<(String, Style)>,
856 code: &Option<String>,
858 max_line_num_len: usize,
861 let mut buffer = StyledBuffer::new();
863 if msp.primary_spans().is_empty() && msp.span_labels().is_empty() && is_secondary {
864 // This is a secondary message with no span info
865 for _ in 0..max_line_num_len {
866 buffer.prepend(0, " ", Style::NoStyle);
868 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
869 buffer.append(0, &level.to_string(), Style::HeaderMsg);
870 buffer.append(0, ": ", Style::NoStyle);
871 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
873 buffer.append(0, &level.to_string(), Style::Level(level.clone()));
876 buffer.append(0, "[", Style::Level(level.clone()));
877 buffer.append(0, &code, Style::Level(level.clone()));
878 buffer.append(0, "]", Style::Level(level.clone()));
882 buffer.append(0, ": ", Style::HeaderMsg);
883 for &(ref text, _) in msg.iter() {
884 buffer.append(0, text, Style::HeaderMsg);
888 // Preprocess all the annotations so that they are grouped by file and by line number
889 // This helps us quickly iterate over the whole message (including secondary file spans)
890 let mut annotated_files = self.preprocess_annotations(msp);
892 // Make sure our primary file comes first
893 let primary_lo = if let (Some(ref cm), Some(ref primary_span)) =
894 (self.cm.as_ref(), msp.primary_span().as_ref()) {
895 if primary_span != &&DUMMY_SP {
896 cm.lookup_char_pos(primary_span.lo)
898 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
902 // If we don't have span information, emit and exit
903 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
907 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
908 annotated_files.swap(0, pos);
911 // Print out the annotate source lines that correspond with the error
912 for annotated_file in annotated_files {
913 // we can't annotate anything if the source is unavailable.
914 if annotated_file.file.src.is_none() {
918 // print out the span location and spacer before we print the annotated source
919 // to do this, we need to know if this span will be primary
920 let is_primary = primary_lo.file.name == annotated_file.file.name;
922 // remember where we are in the output buffer for easy reference
923 let buffer_msg_line_offset = buffer.num_lines();
925 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
926 let loc = primary_lo.clone();
927 buffer.append(buffer_msg_line_offset,
928 &format!("{}:{}:{}", loc.file.name, loc.line, loc.col.0 + 1),
929 Style::LineAndColumn);
930 for _ in 0..max_line_num_len {
931 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
934 // remember where we are in the output buffer for easy reference
935 let buffer_msg_line_offset = buffer.num_lines();
938 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
940 // Then, the secondary file indicator
941 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
942 buffer.append(buffer_msg_line_offset + 1,
943 &annotated_file.file.name,
944 Style::LineAndColumn);
945 for _ in 0..max_line_num_len {
946 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
950 // Put in the spacer between the location and annotated source
951 let buffer_msg_line_offset = buffer.num_lines();
952 draw_col_separator_no_space(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
954 // Contains the vertical lines' positions for active multiline annotations
955 let mut multilines = HashMap::new();
957 // Next, output the annotate source for this file
958 for line_idx in 0..annotated_file.lines.len() {
959 let previous_buffer_line = buffer.num_lines();
961 let width_offset = 3 + max_line_num_len;
962 let code_offset = if annotated_file.multiline_depth == 0 {
965 width_offset + annotated_file.multiline_depth + 1
968 let depths = self.render_source_line(&mut buffer,
969 annotated_file.file.clone(),
970 &annotated_file.lines[line_idx],
974 let mut to_add = HashMap::new();
976 for (depth, style) in depths {
977 if multilines.get(&depth).is_some() {
978 multilines.remove(&depth);
980 to_add.insert(depth, style);
984 // Set the multiline annotation vertical lines to the left of
985 // the code in this line.
986 for (depth, style) in &multilines {
987 for line in previous_buffer_line..buffer.num_lines() {
988 draw_multiline_line(&mut buffer,
995 // check to see if we need to print out or elide lines that come between
996 // this annotated line and the next one.
997 if line_idx < (annotated_file.lines.len() - 1) {
998 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
999 annotated_file.lines[line_idx].line_index;
1000 if line_idx_delta > 2 {
1001 let last_buffer_line_num = buffer.num_lines();
1002 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1004 // Set the multiline annotation vertical lines on `...` bridging line.
1005 for (depth, style) in &multilines {
1006 draw_multiline_line(&mut buffer,
1007 last_buffer_line_num,
1012 } else if line_idx_delta == 2 {
1013 let unannotated_line = annotated_file.file
1014 .get_line(annotated_file.lines[line_idx].line_index)
1017 let last_buffer_line_num = buffer.num_lines();
1019 buffer.puts(last_buffer_line_num,
1021 &(annotated_file.lines[line_idx + 1].line_index - 1)
1024 draw_col_separator(&mut buffer, last_buffer_line_num, 1 + max_line_num_len);
1025 buffer.puts(last_buffer_line_num,
1030 for (depth, style) in &multilines {
1031 draw_multiline_line(&mut buffer,
1032 last_buffer_line_num,
1040 multilines.extend(&to_add);
1044 // final step: take our styled buffer, render it, then output it
1045 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
1049 fn emit_suggestion_default(&mut self,
1050 suggestion: &CodeSuggestion,
1052 max_line_num_len: usize)
1054 use std::borrow::Borrow;
1056 let primary_span = suggestion.substitution_spans().next().unwrap();
1057 if let Some(ref cm) = self.cm {
1058 let mut buffer = StyledBuffer::new();
1060 let lines = cm.span_to_lines(primary_span).unwrap();
1062 assert!(!lines.lines.is_empty());
1064 buffer.append(0, &level.to_string(), Style::Level(level.clone()));
1065 buffer.append(0, ": ", Style::HeaderMsg);
1066 self.msg_to_buffer(&mut buffer,
1067 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1070 Some(Style::HeaderMsg));
1072 let suggestions = suggestion.splice_lines(cm.borrow());
1073 let mut row_num = 1;
1074 for complete in suggestions.iter().take(MAX_SUGGESTIONS) {
1076 // print the suggestion without any line numbers, but leave
1077 // space for them. This helps with lining up with previous
1078 // snippets from the actual error being reported.
1079 let mut lines = complete.lines();
1080 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1081 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1082 buffer.append(row_num, line, Style::NoStyle);
1086 // if we elided some lines, add an ellipsis
1087 if let Some(_) = lines.next() {
1088 buffer.append(row_num, "...", Style::NoStyle);
1091 if suggestions.len() > MAX_SUGGESTIONS {
1092 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1093 buffer.append(row_num, &msg, Style::NoStyle);
1095 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
1099 fn emit_messages_default(&mut self,
1101 message: &Vec<(String, Style)>,
1102 code: &Option<String>,
1104 children: &Vec<SubDiagnostic>) {
1105 let max_line_num = self.get_max_line_num(span, children);
1106 let max_line_num_len = max_line_num.to_string().len();
1108 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1110 if !children.is_empty() {
1111 let mut buffer = StyledBuffer::new();
1112 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1113 match emit_to_destination(&buffer.render(), level, &mut self.dst) {
1115 Err(e) => panic!("failed to emit error: {}", e)
1118 for child in children {
1119 match child.render_span {
1120 Some(FullSpan(ref msp)) => {
1121 match self.emit_message_default(msp,
1122 &child.styled_message(),
1127 Err(e) => panic!("failed to emit error: {}", e),
1131 Some(Suggestion(ref cs)) => {
1132 match self.emit_suggestion_default(cs,
1135 Err(e) => panic!("failed to emit error: {}", e),
1140 match self.emit_message_default(&child.span,
1141 &child.styled_message(),
1146 Err(e) => panic!("failed to emit error: {}", e),
1153 Err(e) => panic!("failed to emit error: {}", e),
1155 match write!(&mut self.dst, "\n") {
1156 Err(e) => panic!("failed to emit error: {}", e),
1158 match self.dst.flush() {
1159 Err(e) => panic!("failed to emit error: {}", e),
1167 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1168 buffer.puts(line, col, "| ", Style::LineNumber);
1171 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1172 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1175 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1179 buffer.putc(line, col, '|', style);
1182 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1183 col_from: usize, col_to: usize, style: Style) {
1184 for col in col_from..col_to {
1185 buffer.putc(line, col, symbol, style);
1189 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1190 buffer.puts(line, col, "= ", Style::LineNumber);
1193 fn draw_multiline_line(buffer: &mut StyledBuffer,
1199 buffer.putc(line, offset + depth - 1, '|', style);
1202 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1203 let extra = if inclusive {
1208 (b_start..b_end + extra).contains(a_start) ||
1209 (a_start..a_end + extra).contains(b_start)
1211 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1212 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1215 fn emit_to_destination(rendered_buffer: &Vec<Vec<StyledString>>,
1217 dst: &mut Destination)
1221 // In order to prevent error message interleaving, where multiple error lines get intermixed
1222 // when multiple compiler processes error simultaneously, we emit errors with additional
1225 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1226 // the .flush() is called we take the buffer created from the buffered writes and write it at
1227 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1228 // scheme, this buffered approach works and maintains the styling.
1230 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1231 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1232 // enough to output the full error message, then we release.
1233 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1234 for line in rendered_buffer {
1236 dst.apply_style(lvl.clone(), part.style)?;
1237 write!(dst, "{}", part.text)?;
1247 fn stderr_isatty() -> bool {
1249 unsafe { libc::isatty(libc::STDERR_FILENO) != 0 }
1252 fn stderr_isatty() -> bool {
1255 type HANDLE = *mut u8;
1256 const STD_ERROR_HANDLE: DWORD = -12i32 as DWORD;
1258 fn GetStdHandle(which: DWORD) -> HANDLE;
1259 fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: *mut DWORD) -> BOOL;
1262 let handle = GetStdHandle(STD_ERROR_HANDLE);
1264 GetConsoleMode(handle, &mut out) != 0
1268 pub type BufferedStderr = term::Terminal<Output = BufferedWriter> + Send;
1270 pub enum Destination {
1271 Terminal(Box<term::StderrTerminal>),
1272 BufferedTerminal(Box<BufferedStderr>),
1273 Raw(Box<Write + Send>),
1276 /// Buffered writer gives us a way on Unix to buffer up an entire error message before we output
1277 /// it. This helps to prevent interleaving of multiple error messages when multiple compiler
1278 /// processes error simultaneously
1279 pub struct BufferedWriter {
1283 impl BufferedWriter {
1284 // note: we use _new because the conditional compilation at its use site may make this
1285 // this function unused on some platforms
1286 fn _new() -> BufferedWriter {
1287 BufferedWriter { buffer: vec![] }
1291 impl Write for BufferedWriter {
1292 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
1294 self.buffer.push(*b);
1298 fn flush(&mut self) -> io::Result<()> {
1299 let mut stderr = io::stderr();
1300 let result = stderr.write_all(&self.buffer)
1301 .and_then(|_| stderr.flush());
1302 self.buffer.clear();
1308 #[cfg(not(windows))]
1309 /// When not on Windows, prefer the buffered terminal so that we can buffer an entire error
1310 /// to be emitted at one time.
1311 fn from_stderr() -> Destination {
1312 let stderr: Option<Box<BufferedStderr>> =
1313 term::TerminfoTerminal::new(BufferedWriter::_new())
1314 .map(|t| Box::new(t) as Box<BufferedStderr>);
1317 Some(t) => BufferedTerminal(t),
1318 None => Raw(Box::new(io::stderr())),
1323 /// Return a normal, unbuffered terminal when on Windows.
1324 fn from_stderr() -> Destination {
1325 let stderr: Option<Box<term::StderrTerminal>> = term::TerminfoTerminal::new(io::stderr())
1326 .map(|t| Box::new(t) as Box<term::StderrTerminal>)
1328 term::WinConsole::new(io::stderr())
1330 .map(|t| Box::new(t) as Box<term::StderrTerminal>)
1334 Some(t) => Terminal(t),
1335 None => Raw(Box::new(io::stderr())),
1339 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1341 Style::FileNameStyle | Style::LineAndColumn => {}
1342 Style::LineNumber => {
1343 self.start_attr(term::Attr::Bold)?;
1345 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_CYAN))?;
1347 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
1350 Style::ErrorCode => {
1351 self.start_attr(term::Attr::Bold)?;
1352 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_MAGENTA))?;
1354 Style::Quotation => {}
1355 Style::OldSchoolNote => {
1356 self.start_attr(term::Attr::Bold)?;
1357 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_GREEN))?;
1359 Style::OldSchoolNoteText | Style::HeaderMsg => {
1360 self.start_attr(term::Attr::Bold)?;
1362 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_WHITE))?;
1365 Style::UnderlinePrimary | Style::LabelPrimary => {
1366 self.start_attr(term::Attr::Bold)?;
1367 self.start_attr(term::Attr::ForegroundColor(lvl.color()))?;
1369 Style::UnderlineSecondary |
1370 Style::LabelSecondary => {
1371 self.start_attr(term::Attr::Bold)?;
1373 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_CYAN))?;
1375 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
1378 Style::NoStyle => {}
1379 Style::Level(l) => {
1380 self.start_attr(term::Attr::Bold)?;
1381 self.start_attr(term::Attr::ForegroundColor(l.color()))?;
1383 Style::Highlight => self.start_attr(term::Attr::Bold)?,
1388 fn start_attr(&mut self, attr: term::Attr) -> io::Result<()> {
1390 Terminal(ref mut t) => {
1393 BufferedTerminal(ref mut t) => {
1401 fn reset_attrs(&mut self) -> io::Result<()> {
1403 Terminal(ref mut t) => {
1406 BufferedTerminal(ref mut t) => {
1415 impl Write for Destination {
1416 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
1418 Terminal(ref mut t) => t.write(bytes),
1419 BufferedTerminal(ref mut t) => t.write(bytes),
1420 Raw(ref mut w) => w.write(bytes),
1423 fn flush(&mut self) -> io::Result<()> {
1425 Terminal(ref mut t) => t.flush(),
1426 BufferedTerminal(ref mut t) => t.flush(),
1427 Raw(ref mut w) => w.flush(),