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 /// Do not use this for messages that end in `\n` – use `println_maybe_styled` instead. See
113 /// `EmitterWriter::print_maybe_styled` for details.
114 macro_rules! print_maybe_styled {
115 ($dst: expr, $style: expr, $($arg: tt)*) => {
116 $dst.print_maybe_styled(format_args!($($arg)*), $style, false)
120 macro_rules! println_maybe_styled {
121 ($dst: expr, $style: expr, $($arg: tt)*) => {
122 $dst.print_maybe_styled(format_args!($($arg)*), $style, true)
127 pub fn stderr(color_config: ColorConfig, code_map: Option<Rc<CodeMapper>>) -> EmitterWriter {
128 if color_config.use_color() {
129 let dst = Destination::from_stderr();
136 dst: Raw(Box::new(io::stderr())),
142 pub fn new(dst: Box<Write + Send>, code_map: Option<Rc<CodeMapper>>) -> EmitterWriter {
149 fn preprocess_annotations(&self, msp: &MultiSpan) -> Vec<FileWithAnnotatedLines> {
150 fn add_annotation_to_file(file_vec: &mut Vec<FileWithAnnotatedLines>,
155 for slot in file_vec.iter_mut() {
156 // Look through each of our files for the one we're adding to
157 if slot.file.name == file.name {
158 // See if we already have a line for it
159 for line_slot in &mut slot.lines {
160 if line_slot.line_index == line_index {
161 line_slot.annotations.push(ann);
165 // We don't have a line yet, create one
166 slot.lines.push(Line {
167 line_index: line_index,
168 annotations: vec![ann],
174 // This is the first time we're seeing the file
175 file_vec.push(FileWithAnnotatedLines {
178 line_index: line_index,
179 annotations: vec![ann],
185 let mut output = vec![];
186 let mut multiline_annotations = vec![];
188 if let Some(ref cm) = self.cm {
189 for span_label in msp.span_labels() {
190 if span_label.span == DUMMY_SP {
193 let lo = cm.lookup_char_pos(span_label.span.lo);
194 let mut hi = cm.lookup_char_pos(span_label.span.hi);
196 // Watch out for "empty spans". If we get a span like 6..6, we
197 // want to just display a `^` at 6, so convert that to
198 // 6..7. This is degenerate input, but it's best to degrade
199 // gracefully -- and the parser likes to supply a span like
200 // that for EOF, in particular.
201 if lo.col == hi.col && lo.line == hi.line {
202 hi.col = CharPos(lo.col.0 + 1);
205 let ann_type = if lo.line != hi.line {
206 let ml = MultilineAnnotation {
212 is_primary: span_label.is_primary,
213 label: span_label.label.clone(),
215 multiline_annotations.push((lo.file.clone(), ml.clone()));
216 AnnotationType::Multiline(ml)
218 AnnotationType::Singleline
220 let ann = Annotation {
223 is_primary: span_label.is_primary,
224 label: span_label.label.clone(),
225 annotation_type: ann_type,
228 if !ann.is_multiline() {
229 add_annotation_to_file(&mut output,
237 // Find overlapping multiline annotations, put them at different depths
238 multiline_annotations.sort_by(|a, b| {
239 (a.1.line_start, a.1.line_end).cmp(&(b.1.line_start, b.1.line_end))
241 for item in multiline_annotations.clone() {
243 for item in multiline_annotations.iter_mut() {
244 let ref mut a = item.1;
245 // Move all other multiline annotations overlapping with this one
246 // one level to the right.
248 num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true)
257 let mut max_depth = 0; // max overlapping multiline spans
258 for (file, ann) in multiline_annotations {
259 if ann.depth > max_depth {
260 max_depth = ann.depth;
262 add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start());
263 let middle = min(ann.line_start + 4, ann.line_end);
264 for line in ann.line_start + 1..middle {
265 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
267 if middle < ann.line_end - 1 {
268 for line in ann.line_end - 1..ann.line_end {
269 add_annotation_to_file(&mut output, file.clone(), line, ann.as_line());
272 add_annotation_to_file(&mut output, file, ann.line_end, ann.as_end());
274 for file_vec in output.iter_mut() {
275 file_vec.multiline_depth = max_depth;
280 fn render_source_line(&self,
281 buffer: &mut StyledBuffer,
285 code_offset: usize) -> Vec<(usize, Style)> {
286 let source_string = match file.get_line(line.line_index - 1) {
288 None => return Vec::new(),
291 let line_offset = buffer.num_lines();
293 // First create the source line we will highlight.
294 buffer.puts(line_offset, code_offset, &source_string, Style::Quotation);
295 buffer.puts(line_offset,
297 &(line.line_index.to_string()),
300 draw_col_separator(buffer, line_offset, width_offset - 2);
302 // Special case when there's only one annotation involved, it is the start of a multiline
303 // span and there's no text at the beginning of the code line. Instead of doing the whole
312 // we simplify the output to:
318 if line.annotations.len() == 1 {
319 if let Some(ref ann) = line.annotations.get(0) {
320 if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
321 if source_string[0..ann.start_col].trim() == "" {
322 let style = if ann.is_primary {
323 Style::UnderlinePrimary
325 Style::UnderlineSecondary
327 buffer.putc(line_offset,
328 width_offset + depth - 1,
331 return vec![(depth, style)];
337 // We want to display like this:
339 // vec.push(vec.pop().unwrap());
340 // --- ^^^ - previous borrow ends here
342 // | error occurs here
343 // previous borrow of `vec` occurs here
345 // But there are some weird edge cases to be aware of:
347 // vec.push(vec.pop().unwrap());
348 // -------- - previous borrow ends here
350 // |this makes no sense
351 // previous borrow of `vec` occurs here
353 // For this reason, we group the lines into "highlight lines"
354 // and "annotations lines", where the highlight lines have the `^`.
356 // Sort the annotations by (start, end col)
357 let mut annotations = line.annotations.clone();
359 annotations.reverse();
361 // First, figure out where each label will be positioned.
363 // In the case where you have the following annotations:
365 // vec.push(vec.pop().unwrap());
366 // -------- - previous borrow ends here [C]
368 // |this makes no sense [B]
369 // previous borrow of `vec` occurs here [A]
371 // `annotations_position` will hold [(2, A), (1, B), (0, C)].
373 // We try, when possible, to stick the rightmost annotation at the end
374 // of the highlight line:
376 // vec.push(vec.pop().unwrap());
377 // --- --- - previous borrow ends here
379 // But sometimes that's not possible because one of the other
380 // annotations overlaps it. For example, from the test
381 // `span_overlap_label`, we have the following annotations
382 // (written on distinct lines for clarity):
388 // In this case, we can't stick the rightmost-most label on
389 // the highlight line, or we would get:
396 // which is totally weird. Instead we want:
404 // which is...less weird, at least. In fact, in general, if
405 // the rightmost span overlaps with any other span, we should
406 // use the "hang below" version, so we can at least make it
407 // clear where the span *starts*. There's an exception for this
408 // logic, when the labels do not have a message:
423 let mut annotations_position = vec![];
424 let mut line_len = 0;
426 for (i, annotation) in annotations.iter().enumerate() {
427 for (j, next) in annotations.iter().enumerate() {
428 if overlaps(next, annotation, 0) // This label overlaps with another one and both
429 && annotation.has_label() // take space (they have text and are not
430 && j > i // multiline lines).
431 && p == 0 // We're currently on the first line, move the label one line down
433 // This annotation needs a new line in the output.
438 annotations_position.push((p, annotation));
439 for (j, next) in annotations.iter().enumerate() {
441 let l = if let Some(ref label) = next.label {
446 if (overlaps(next, annotation, l) // Do not allow two labels to be in the same
447 // line if they overlap including padding, to
448 // avoid situations like:
455 && annotation.has_label() // Both labels must have some text, otherwise
456 && next.has_label()) // they are not overlapping.
457 // Do not add a new line if this annotation
458 // or the next are vertical line placeholders.
459 || (annotation.takes_space() // If either this or the next annotation is
460 && next.has_label()) // multiline start/end, move it to a new line
461 || (annotation.has_label() // so as not to overlap the orizontal lines.
462 && next.takes_space())
463 || (annotation.takes_space()
464 && next.takes_space())
466 // This annotation needs a new line in the output.
481 // If there are no annotations or the only annotations on this line are
482 // MultilineLine, then there's only code being shown, stop processing.
483 if line.annotations.is_empty() || line.annotations.iter()
484 .filter(|a| !a.is_line()).collect::<Vec<_>>().len() == 0
489 // Write the colunmn separator.
491 // After this we will have:
500 for pos in 0..line_len + 1 {
501 draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2);
502 buffer.putc(line_offset + pos + 1,
508 // Write the horizontal lines for multiline annotations
509 // (only the first and last lines need this).
511 // After this we will have:
520 for &(pos, annotation) in &annotations_position {
521 let style = if annotation.is_primary {
522 Style::UnderlinePrimary
524 Style::UnderlineSecondary
527 match annotation.annotation_type {
528 AnnotationType::MultilineStart(depth) |
529 AnnotationType::MultilineEnd(depth) => {
533 width_offset + depth,
534 code_offset + annotation.start_col,
541 // Write the vertical lines for labels that are on a different line as the underline.
543 // After this we will have:
552 for &(pos, annotation) in &annotations_position {
553 let style = if annotation.is_primary {
554 Style::UnderlinePrimary
556 Style::UnderlineSecondary
560 if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
561 for p in line_offset + 1..line_offset + pos + 1 {
563 code_offset + annotation.start_col,
568 match annotation.annotation_type {
569 AnnotationType::MultilineStart(depth) => {
570 for p in line_offset + pos + 1..line_offset + line_len + 2 {
572 width_offset + depth - 1,
577 AnnotationType::MultilineEnd(depth) => {
578 for p in line_offset..line_offset + pos + 1 {
580 width_offset + depth - 1,
589 // Write the labels on the annotations that actually have a label.
591 // After this we will have:
596 // | something about `foo`
600 for &(pos, annotation) in &annotations_position {
601 let style = if annotation.is_primary {
604 Style::LabelSecondary
606 let (pos, col) = if pos == 0 {
607 (pos + 1, annotation.end_col + 1)
609 (pos + 2, annotation.start_col)
611 if let Some(ref label) = annotation.label {
612 buffer.puts(line_offset + pos,
619 // Sort from biggest span to smallest span so that smaller spans are
620 // represented in the output:
625 // | | something about `foo`
626 // | something about `fn foo()`
627 annotations_position.sort_by(|a, b| {
629 a.1.len().cmp(&b.1.len()).reverse()
632 // Write the underlines.
634 // After this we will have:
639 // | something about `foo`
643 for &(_, annotation) in &annotations_position {
644 let (underline, style) = if annotation.is_primary {
645 ('^', Style::UnderlinePrimary)
647 ('-', Style::UnderlineSecondary)
649 for p in annotation.start_col..annotation.end_col {
650 buffer.putc(line_offset + 1,
656 annotations_position.iter().filter_map(|&(_, annotation)| {
657 match annotation.annotation_type {
658 AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => {
659 let style = if annotation.is_primary {
662 Style::LabelSecondary
669 }).collect::<Vec<_>>()
672 fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize {
674 if let Some(ref cm) = self.cm {
675 for primary_span in msp.primary_spans() {
676 if primary_span != &DUMMY_SP {
677 let hi = cm.lookup_char_pos(primary_span.hi);
683 for span_label in msp.span_labels() {
684 if span_label.span != DUMMY_SP {
685 let hi = cm.lookup_char_pos(span_label.span.hi);
695 fn get_max_line_num(&mut self, span: &MultiSpan, children: &Vec<SubDiagnostic>) -> usize {
698 let primary = self.get_multispan_max_line_num(span);
699 max = if primary > max { primary } else { max };
701 for sub in children {
702 let sub_result = self.get_multispan_max_line_num(&sub.span);
703 max = if sub_result > max { primary } else { max };
708 // This "fixes" MultiSpans that contain Spans that are pointing to locations inside of
709 // <*macros>. Since these locations are often difficult to read, we move these Spans from
710 // <*macros> to their corresponding use site.
711 fn fix_multispan_in_std_macros(&mut self, span: &mut MultiSpan) -> bool {
712 let mut spans_updated = false;
714 if let Some(ref cm) = self.cm {
715 let mut before_after: Vec<(Span, Span)> = vec![];
716 let mut new_labels: Vec<(Span, String)> = vec![];
718 // First, find all the spans in <*macros> and point instead at their use site
719 for sp in span.primary_spans() {
723 if cm.span_to_filename(sp.clone()).contains("macros>") {
724 let v = sp.macro_backtrace();
725 if let Some(use_site) = v.last() {
726 before_after.push((sp.clone(), use_site.call_site.clone()));
729 for trace in sp.macro_backtrace().iter().rev() {
730 // Only show macro locations that are local
731 // and display them like a span_note
732 if let Some(def_site) = trace.def_site_span {
733 if def_site == DUMMY_SP {
736 // Check to make sure we're not in any <*macros>
737 if !cm.span_to_filename(def_site).contains("macros>") &&
738 !trace.macro_decl_name.starts_with("#[") {
739 new_labels.push((trace.call_site,
740 "in this macro invocation".to_string()));
746 for (label_span, label_text) in new_labels {
747 span.push_span_label(label_span, label_text);
749 for sp_label in span.span_labels() {
750 if sp_label.span == DUMMY_SP {
753 if cm.span_to_filename(sp_label.span.clone()).contains("macros>") {
754 let v = sp_label.span.macro_backtrace();
755 if let Some(use_site) = v.last() {
756 before_after.push((sp_label.span.clone(), use_site.call_site.clone()));
760 // After we have them, make sure we replace these 'bad' def sites with their use sites
761 for (before, after) in before_after {
762 span.replace(before, after);
763 spans_updated = true;
770 // This does a small "fix" for multispans by looking to see if it can find any that
771 // point directly at <*macros>. Since these are often difficult to read, this
772 // will change the span to point at the use site.
773 fn fix_multispans_in_std_macros(&mut self,
774 span: &mut MultiSpan,
775 children: &mut Vec<SubDiagnostic>) {
776 let mut spans_updated = self.fix_multispan_in_std_macros(span);
777 for child in children.iter_mut() {
778 spans_updated |= self.fix_multispan_in_std_macros(&mut child.span);
781 children.push(SubDiagnostic {
783 message: vec![("this error originates in a macro outside of the current crate"
784 .to_string(), Style::NoStyle)],
785 span: MultiSpan::new(),
791 /// Add a left margin to every line but the first, given a padding length and the label being
792 /// displayed, keeping the provided highlighting.
793 fn msg_to_buffer(&self,
794 buffer: &mut StyledBuffer,
795 msg: &[(String, Style)],
798 override_style: Option<Style>) {
800 // The extra 5 ` ` is padding that's always needed to align to the `note: `:
813 // | | length of label
815 // `max_line_num_len`
816 let padding = (0..padding + label.len() + 5)
818 .collect::<String>();
820 /// Return wether `style`, or the override if present and the style is `NoStyle`.
821 fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
822 if let Some(o) = override_style {
823 if style == Style::NoStyle {
830 let mut line_number = 0;
832 // Provided the following diagnostic message:
836 // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle),
837 // ("looks", Style::Highlight),
838 // ("with\nvery ", Style::NoStyle),
839 // ("weird", Style::Highlight),
840 // (" formats\n", Style::NoStyle),
841 // ("see?", Style::Highlight),
844 // the expected output on a note is (* surround the highlighted text)
846 // = note: highlighted multiline
848 // see how it *looks* with
849 // very *weird* formats
851 for &(ref text, ref style) in msg.iter() {
852 let lines = text.split('\n').collect::<Vec<_>>();
854 for (i, line) in lines.iter().enumerate() {
857 buffer.append(line_number, &padding, Style::NoStyle);
859 buffer.append(line_number, line, style_or_override(*style, override_style));
862 buffer.append(line_number, text, style_or_override(*style, override_style));
867 fn emit_message_default(&mut self,
869 msg: &Vec<(String, Style)>,
870 code: &Option<String>,
872 max_line_num_len: usize,
875 let mut buffer = StyledBuffer::new();
877 if msp.primary_spans().is_empty() && msp.span_labels().is_empty() && is_secondary {
878 // This is a secondary message with no span info
879 for _ in 0..max_line_num_len {
880 buffer.prepend(0, " ", Style::NoStyle);
882 draw_note_separator(&mut buffer, 0, max_line_num_len + 1);
883 buffer.append(0, &level.to_string(), Style::HeaderMsg);
884 buffer.append(0, ": ", Style::NoStyle);
885 self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None);
887 buffer.append(0, &level.to_string(), Style::Level(level.clone()));
890 buffer.append(0, "[", Style::Level(level.clone()));
891 buffer.append(0, &code, Style::Level(level.clone()));
892 buffer.append(0, "]", Style::Level(level.clone()));
896 buffer.append(0, ": ", Style::HeaderMsg);
897 for &(ref text, _) in msg.iter() {
898 buffer.append(0, text, Style::HeaderMsg);
902 // Preprocess all the annotations so that they are grouped by file and by line number
903 // This helps us quickly iterate over the whole message (including secondary file spans)
904 let mut annotated_files = self.preprocess_annotations(msp);
906 // Make sure our primary file comes first
907 let primary_lo = if let (Some(ref cm), Some(ref primary_span)) =
908 (self.cm.as_ref(), msp.primary_span().as_ref()) {
909 if primary_span != &&DUMMY_SP {
910 cm.lookup_char_pos(primary_span.lo)
912 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
916 // If we don't have span information, emit and exit
917 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
921 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) {
922 annotated_files.swap(0, pos);
925 // Print out the annotate source lines that correspond with the error
926 for annotated_file in annotated_files {
927 // we can't annotate anything if the source is unavailable.
928 if annotated_file.file.src.is_none() {
932 // print out the span location and spacer before we print the annotated source
933 // to do this, we need to know if this span will be primary
934 let is_primary = primary_lo.file.name == annotated_file.file.name;
936 // remember where we are in the output buffer for easy reference
937 let buffer_msg_line_offset = buffer.num_lines();
939 buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber);
940 let loc = primary_lo.clone();
941 buffer.append(buffer_msg_line_offset,
942 &format!("{}:{}:{}", loc.file.name, loc.line, loc.col.0 + 1),
943 Style::LineAndColumn);
944 for _ in 0..max_line_num_len {
945 buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle);
948 // remember where we are in the output buffer for easy reference
949 let buffer_msg_line_offset = buffer.num_lines();
952 draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
954 // Then, the secondary file indicator
955 buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber);
956 buffer.append(buffer_msg_line_offset + 1,
957 &annotated_file.file.name,
958 Style::LineAndColumn);
959 for _ in 0..max_line_num_len {
960 buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle);
964 // Put in the spacer between the location and annotated source
965 let buffer_msg_line_offset = buffer.num_lines();
966 draw_col_separator_no_space(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1);
968 // Contains the vertical lines' positions for active multiline annotations
969 let mut multilines = HashMap::new();
971 // Next, output the annotate source for this file
972 for line_idx in 0..annotated_file.lines.len() {
973 let previous_buffer_line = buffer.num_lines();
975 let width_offset = 3 + max_line_num_len;
976 let code_offset = if annotated_file.multiline_depth == 0 {
979 width_offset + annotated_file.multiline_depth + 1
982 let depths = self.render_source_line(&mut buffer,
983 annotated_file.file.clone(),
984 &annotated_file.lines[line_idx],
988 let mut to_add = HashMap::new();
990 for (depth, style) in depths {
991 if multilines.get(&depth).is_some() {
992 multilines.remove(&depth);
994 to_add.insert(depth, style);
998 // Set the multiline annotation vertical lines to the left of
999 // the code in this line.
1000 for (depth, style) in &multilines {
1001 for line in previous_buffer_line..buffer.num_lines() {
1002 draw_multiline_line(&mut buffer,
1009 // check to see if we need to print out or elide lines that come between
1010 // this annotated line and the next one.
1011 if line_idx < (annotated_file.lines.len() - 1) {
1012 let line_idx_delta = annotated_file.lines[line_idx + 1].line_index -
1013 annotated_file.lines[line_idx].line_index;
1014 if line_idx_delta > 2 {
1015 let last_buffer_line_num = buffer.num_lines();
1016 buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber);
1018 // Set the multiline annotation vertical lines on `...` bridging line.
1019 for (depth, style) in &multilines {
1020 draw_multiline_line(&mut buffer,
1021 last_buffer_line_num,
1026 } else if line_idx_delta == 2 {
1027 let unannotated_line = annotated_file.file
1028 .get_line(annotated_file.lines[line_idx].line_index)
1031 let last_buffer_line_num = buffer.num_lines();
1033 buffer.puts(last_buffer_line_num,
1035 &(annotated_file.lines[line_idx + 1].line_index - 1)
1038 draw_col_separator(&mut buffer, last_buffer_line_num, 1 + max_line_num_len);
1039 buffer.puts(last_buffer_line_num,
1044 for (depth, style) in &multilines {
1045 draw_multiline_line(&mut buffer,
1046 last_buffer_line_num,
1054 multilines.extend(&to_add);
1058 // final step: take our styled buffer, render it, then output it
1059 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
1063 fn emit_suggestion_default(&mut self,
1064 suggestion: &CodeSuggestion,
1066 max_line_num_len: usize)
1068 use std::borrow::Borrow;
1070 let primary_span = suggestion.substitution_spans().next().unwrap();
1071 if let Some(ref cm) = self.cm {
1072 let mut buffer = StyledBuffer::new();
1074 let lines = cm.span_to_lines(primary_span).unwrap();
1076 assert!(!lines.lines.is_empty());
1078 buffer.append(0, &level.to_string(), Style::Level(level.clone()));
1079 buffer.append(0, ": ", Style::HeaderMsg);
1080 self.msg_to_buffer(&mut buffer,
1081 &[(suggestion.msg.to_owned(), Style::NoStyle)],
1084 Some(Style::HeaderMsg));
1086 let suggestions = suggestion.splice_lines(cm.borrow());
1087 let mut row_num = 1;
1088 for complete in suggestions.iter().take(MAX_SUGGESTIONS) {
1090 // print the suggestion without any line numbers, but leave
1091 // space for them. This helps with lining up with previous
1092 // snippets from the actual error being reported.
1093 let mut lines = complete.lines();
1094 for line in lines.by_ref().take(MAX_HIGHLIGHT_LINES) {
1095 draw_col_separator(&mut buffer, row_num, max_line_num_len + 1);
1096 buffer.append(row_num, line, Style::NoStyle);
1100 // if we elided some lines, add an ellipsis
1101 if let Some(_) = lines.next() {
1102 buffer.append(row_num, "...", Style::NoStyle);
1105 if suggestions.len() > MAX_SUGGESTIONS {
1106 let msg = format!("and {} other candidates", suggestions.len() - MAX_SUGGESTIONS);
1107 buffer.append(row_num, &msg, Style::NoStyle);
1109 emit_to_destination(&buffer.render(), level, &mut self.dst)?;
1113 fn emit_messages_default(&mut self,
1115 message: &Vec<(String, Style)>,
1116 code: &Option<String>,
1118 children: &Vec<SubDiagnostic>) {
1119 let max_line_num = self.get_max_line_num(span, children);
1120 let max_line_num_len = max_line_num.to_string().len();
1122 match self.emit_message_default(span, message, code, level, max_line_num_len, false) {
1124 if !children.is_empty() {
1125 let mut buffer = StyledBuffer::new();
1126 draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1);
1127 match emit_to_destination(&buffer.render(), level, &mut self.dst) {
1129 Err(e) => panic!("failed to emit error: {}", e)
1132 for child in children {
1133 match child.render_span {
1134 Some(FullSpan(ref msp)) => {
1135 match self.emit_message_default(msp,
1136 &child.styled_message(),
1141 Err(e) => panic!("failed to emit error: {}", e),
1145 Some(Suggestion(ref cs)) => {
1146 match self.emit_suggestion_default(cs,
1149 Err(e) => panic!("failed to emit error: {}", e),
1154 match self.emit_message_default(&child.span,
1155 &child.styled_message(),
1160 Err(e) => panic!("failed to emit error: {}", e),
1167 Err(e) => panic!("failed to emit error: {}", e),
1169 match write!(&mut self.dst, "\n") {
1170 Err(e) => panic!("failed to emit error: {}", e),
1172 match self.dst.flush() {
1173 Err(e) => panic!("failed to emit error: {}", e),
1181 fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1182 buffer.puts(line, col, "| ", Style::LineNumber);
1185 fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) {
1186 draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber);
1189 fn draw_col_separator_no_space_with_style(buffer: &mut StyledBuffer,
1193 buffer.putc(line, col, '|', style);
1196 fn draw_range(buffer: &mut StyledBuffer, symbol: char, line: usize,
1197 col_from: usize, col_to: usize, style: Style) {
1198 for col in col_from..col_to {
1199 buffer.putc(line, col, symbol, style);
1203 fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) {
1204 buffer.puts(line, col, "= ", Style::LineNumber);
1207 fn draw_multiline_line(buffer: &mut StyledBuffer,
1213 buffer.putc(line, offset + depth - 1, '|', style);
1216 fn num_overlap(a_start: usize, a_end: usize, b_start: usize, b_end:usize, inclusive: bool) -> bool {
1217 let extra = if inclusive {
1222 (b_start..b_end + extra).contains(a_start) ||
1223 (a_start..a_end + extra).contains(b_start)
1225 fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool {
1226 num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false)
1229 fn emit_to_destination(rendered_buffer: &Vec<Vec<StyledString>>,
1231 dst: &mut Destination)
1235 // In order to prevent error message interleaving, where multiple error lines get intermixed
1236 // when multiple compiler processes error simultaneously, we emit errors with additional
1239 // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When
1240 // the .flush() is called we take the buffer created from the buffered writes and write it at
1241 // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling
1242 // scheme, this buffered approach works and maintains the styling.
1244 // On Windows, styling happens through calls to a terminal API. This prevents us from using the
1245 // same buffering approach. Instead, we use a global Windows mutex, which we acquire long
1246 // enough to output the full error message, then we release.
1247 let _buffer_lock = lock::acquire_global_lock("rustc_errors");
1248 for line in rendered_buffer {
1250 dst.apply_style(lvl.clone(), part.style)?;
1251 write!(dst, "{}", part.text)?;
1261 fn stderr_isatty() -> bool {
1263 unsafe { libc::isatty(libc::STDERR_FILENO) != 0 }
1266 fn stderr_isatty() -> bool {
1269 type HANDLE = *mut u8;
1270 const STD_ERROR_HANDLE: DWORD = -12i32 as DWORD;
1272 fn GetStdHandle(which: DWORD) -> HANDLE;
1273 fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: *mut DWORD) -> BOOL;
1276 let handle = GetStdHandle(STD_ERROR_HANDLE);
1278 GetConsoleMode(handle, &mut out) != 0
1282 pub type BufferedStderr = term::Terminal<Output = BufferedWriter> + Send;
1284 pub enum Destination {
1285 Terminal(Box<term::StderrTerminal>),
1286 BufferedTerminal(Box<BufferedStderr>),
1287 Raw(Box<Write + Send>),
1290 /// Buffered writer gives us a way on Unix to buffer up an entire error message before we output
1291 /// it. This helps to prevent interleaving of multiple error messages when multiple compiler
1292 /// processes error simultaneously
1293 pub struct BufferedWriter {
1297 impl BufferedWriter {
1298 // note: we use _new because the conditional compilation at its use site may make this
1299 // this function unused on some platforms
1300 fn _new() -> BufferedWriter {
1301 BufferedWriter { buffer: vec![] }
1305 impl Write for BufferedWriter {
1306 fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
1308 self.buffer.push(*b);
1312 fn flush(&mut self) -> io::Result<()> {
1313 let mut stderr = io::stderr();
1315 stderr.write_all(&self.buffer)?;
1318 self.buffer.clear();
1324 #[cfg(not(windows))]
1325 /// When not on Windows, prefer the buffered terminal so that we can buffer an entire error
1326 /// to be emitted at one time.
1327 fn from_stderr() -> Destination {
1328 let stderr: Option<Box<BufferedStderr>> =
1329 term::TerminfoTerminal::new(BufferedWriter::_new())
1330 .map(|t| Box::new(t) as Box<BufferedStderr>);
1333 Some(t) => BufferedTerminal(t),
1334 None => Raw(Box::new(io::stderr())),
1339 /// Return a normal, unbuffered terminal when on Windows.
1340 fn from_stderr() -> Destination {
1341 let stderr: Option<Box<term::StderrTerminal>> = term::TerminfoTerminal::new(io::stderr())
1342 .map(|t| Box::new(t) as Box<term::StderrTerminal>)
1344 term::WinConsole::new(io::stderr())
1346 .map(|t| Box::new(t) as Box<term::StderrTerminal>)
1350 Some(t) => Terminal(t),
1351 None => Raw(Box::new(io::stderr())),
1355 fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> {
1357 Style::FileNameStyle | Style::LineAndColumn => {}
1358 Style::LineNumber => {
1359 self.start_attr(term::Attr::Bold)?;
1361 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_CYAN))?;
1363 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
1366 Style::ErrorCode => {
1367 self.start_attr(term::Attr::Bold)?;
1368 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_MAGENTA))?;
1370 Style::Quotation => {}
1371 Style::OldSchoolNote => {
1372 self.start_attr(term::Attr::Bold)?;
1373 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_GREEN))?;
1375 Style::OldSchoolNoteText | Style::HeaderMsg => {
1376 self.start_attr(term::Attr::Bold)?;
1378 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_WHITE))?;
1381 Style::UnderlinePrimary | Style::LabelPrimary => {
1382 self.start_attr(term::Attr::Bold)?;
1383 self.start_attr(term::Attr::ForegroundColor(lvl.color()))?;
1385 Style::UnderlineSecondary |
1386 Style::LabelSecondary => {
1387 self.start_attr(term::Attr::Bold)?;
1389 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_CYAN))?;
1391 self.start_attr(term::Attr::ForegroundColor(term::color::BRIGHT_BLUE))?;
1394 Style::NoStyle => {}
1395 Style::Level(l) => {
1396 self.start_attr(term::Attr::Bold)?;
1397 self.start_attr(term::Attr::ForegroundColor(l.color()))?;
1399 Style::Highlight => self.start_attr(term::Attr::Bold)?,
1404 fn start_attr(&mut self, attr: term::Attr) -> io::Result<()> {
1406 Terminal(ref mut t) => {
1409 BufferedTerminal(ref mut t) => {
1417 fn reset_attrs(&mut self) -> io::Result<()> {
1419 Terminal(ref mut t) => {
1422 BufferedTerminal(ref mut t) => {
1431 impl Write for Destination {
1432 fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
1434 Terminal(ref mut t) => t.write(bytes),
1435 BufferedTerminal(ref mut t) => t.write(bytes),
1436 Raw(ref mut w) => w.write(bytes),
1439 fn flush(&mut self) -> io::Result<()> {
1441 Terminal(ref mut t) => t.flush(),
1442 BufferedTerminal(ref mut t) => t.flush(),
1443 Raw(ref mut w) => w.flush(),