Skip to content

On long spans, trim the middle of them to make them fit in the terminal width #137757

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Mar 8, 2025
Merged

On long spans, trim the middle of them to make them fit in the terminal width #137757

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
d975bd3
Remove highlighting of spans on `-Zteach`
estebank Feb 27, 2025
72326bf
On long spans, trim the middle of them to make them fit in the termin…
estebank Feb 27, 2025
f1c751b
Refactor `emitter` to better account for unicode chars when trimming
estebank Feb 27, 2025
cb82b79
Fix rustdoc test
estebank Feb 27, 2025
c75da0e
Fix multiline span start special case
estebank Feb 27, 2025
a04c47a
Make trimming logic work on more than one span at a time
estebank Feb 28, 2025
db2fb71
fix rebase
estebank Mar 7, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Refactor emitter to better account for unicode chars when trimming 
Change the way that underline positions are calculated by delaying using
the "visual" column position until the last possible moment, instead
using the "file"/byte position in the file, and then calculating visual
positioning as late as possible. This should make the underlines more
resilient to non-1-width unicode chars.

Unfortunately, as part of this change (which fixes some visual bugs)
comes with the loss of some eager tab codepoint handling, but the output
remains legible despite some minor regression on the "margin trimming"
logic.
  • Loading branch information
@estebank
estebank committed Mar 7, 2025
commit f1c751bc1a08e3439a9d0c482cbb0ea0fc8f644f
177 changes: 99 additions & 78 deletions compiler/rustc_errors/src/emitter.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -113,24 +113,11 @@ impl Margin {
self.computed_left > 0
}

fn was_cut_right(&self, line_len: usize) -> bool {
let right =
if self.computed_right == self.span_right || self.computed_right == self.label_right {
// FIXME: This comment refers to the only callsite of this method.
// Rephrase it or refactor it, so it can stand on its own.
// Account for the "..." padding given above. Otherwise we end up with code lines
// that do fit but end in "..." as if they were trimmed.
// FIXME: Don't hard-code this offset. Is this meant to represent
// `2 * str_width(self.margin())`?
self.computed_right - 6
} else {
self.computed_right
};
right < line_len && self.computed_left + self.column_width < line_len
}

fn compute(&mut self, max_line_len: usize) {
// When there's a lot of whitespace (>20), we want to trim it as it is useless.
// FIXME: this doesn't account for '\t', but to do so correctly we need to perform that
// calculation later, right before printing in order to be accurate with both unicode
// handling and trimming of long lines.
self.computed_left = if self.whitespace_left > 20 {
self.whitespace_left - 16 // We want some padding.
} else {
Expand Down Expand Up @@ -668,43 +655,43 @@ impl HumanEmitter {
width_offset: usize,
code_offset: usize,
margin: Margin,
) {
// Tabs are assumed to have been replaced by spaces in calling code.
debug_assert!(!source_string.contains('\t'));
) -> usize {
let line_len = source_string.len();
// Create the source line we will highlight.
let left = margin.left(line_len);
let right = margin.right(line_len);
// FIXME: The following code looks fishy. See #132860.
// On long lines, we strip the source line, accounting for unicode.
let mut taken = 0;
let code: String = source_string
.chars()
.skip(left)
.take_while(|ch| {
// Make sure that the trimming on the right will fall within the terminal width.
let next = char_width(*ch);
if taken + next > right - left {
return false;
}
taken += next;
true
})
.enumerate()
.skip_while(|(i, _)| *i < left)
.take_while(|(i, _)| *i < right)
.map(|(_, c)| c)
.collect();
let code = normalize_whitespace(&code);
let was_cut_right =
source_string.chars().enumerate().skip_while(|(i, _)| *i < right).next().is_some();
buffer.puts(line_offset, code_offset, &code, Style::Quotation);
let placeholder = self.margin();
if margin.was_cut_left() {
// We have stripped some code/whitespace from the beginning, make it clear.
buffer.puts(line_offset, code_offset, placeholder, Style::LineNumber);
}
if margin.was_cut_right(line_len) {
if was_cut_right {
let padding = str_width(placeholder);
// We have stripped some code after the rightmost span end, make it clear we did so.
buffer.puts(line_offset, code_offset + taken - padding, placeholder, Style::LineNumber);
buffer.puts(
line_offset,
code_offset + str_width(&code) - padding,
placeholder,
Style::LineNumber,
);
}
buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber);

self.draw_col_separator_no_space(buffer, line_offset, width_offset - 2);
left
}

#[instrument(level = "trace", skip(self), ret)]
Expand Down Expand Up @@ -736,22 +723,16 @@ impl HumanEmitter {
return Vec::new();
}

let source_string = match file.get_line(line.line_index - 1) {
Some(s) => normalize_whitespace(&s),
None => return Vec::new(),
let Some(source_string) = file.get_line(line.line_index - 1) else {
return Vec::new();
};
trace!(?source_string);

let line_offset = buffer.num_lines();

// Left trim
let left = margin.left(source_string.len());

// Left trim.
// FIXME: This looks fishy. See #132860.
// Account for unicode characters of width !=0 that were removed.
let left = source_string.chars().take(left).map(|ch| char_width(ch)).sum();

self.draw_line(
let left = self.draw_line(
buffer,
&source_string,
line.line_index,
Expand Down Expand Up @@ -1033,12 +1014,18 @@ impl HumanEmitter {
let pos = pos + 1;
match annotation.annotation_type {
AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => {
let pre: usize = source_string
.chars()
.take(annotation.start_col.file)
.skip(left)
.map(|c| char_width(c))
.sum();
self.draw_range(
buffer,
underline.multiline_horizontal,
line_offset + pos,
width_offset + depth,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset + pre,
underline.style,
);
}
Expand All @@ -1061,11 +1048,18 @@ impl HumanEmitter {
let underline = self.underline(annotation.is_primary);
let pos = pos + 1;

let code_offset = code_offset
+ source_string
.chars()
.take(annotation.start_col.file)
.skip(left)
.map(|c| char_width(c))
.sum::<usize>();
if pos > 1 && (annotation.has_label() || annotation.takes_space()) {
for p in line_offset + 1..=line_offset + pos {
buffer.putc(
p,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset,
match annotation.annotation_type {
AnnotationType::MultilineLine(_) => underline.multiline_vertical,
_ => underline.vertical_text_line,
Expand All @@ -1076,7 +1070,7 @@ impl HumanEmitter {
if let AnnotationType::MultilineStart(_) = annotation.annotation_type {
buffer.putc(
line_offset + pos,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset,
underline.bottom_right,
underline.style,
);
Expand All @@ -1086,7 +1080,7 @@ impl HumanEmitter {
{
buffer.putc(
line_offset + pos,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset,
underline.multiline_bottom_right_with_text,
underline.style,
);
Expand Down Expand Up @@ -1144,13 +1138,30 @@ impl HumanEmitter {
let style =
if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary };
let (pos, col) = if pos == 0 {
if annotation.end_col.display == 0 {
(pos + 1, (annotation.end_col.display + 2).saturating_sub(left))
let pre: usize = source_string
.chars()
.take(annotation.end_col.file)
.skip(left)
.map(|c| char_width(c))
.sum();
if annotation.end_col.file == 0 {
(pos + 1, (pre + 2))
} else {
(pos + 1, (annotation.end_col.display + 1).saturating_sub(left))
let pad = if annotation.end_col.file - annotation.start_col.file == 0 {
2
} else {
1
};
(pos + 1, (pre + pad))
}
} else {
(pos + 2, annotation.start_col.display.saturating_sub(left))
let pre: usize = source_string
.chars()
.take(annotation.start_col.file)
.skip(left)
.map(|c| char_width(c))
.sum();
(pos + 2, pre)
};
if let Some(ref label) = annotation.label {
buffer.puts(line_offset + pos, code_offset + col, label, style);
Expand Down Expand Up @@ -1183,14 +1194,35 @@ impl HumanEmitter {
// | _^ test
for &(pos, annotation) in &annotations_position {
let uline = self.underline(annotation.is_primary);
for p in annotation.start_col.display..annotation.end_col.display {
let width = annotation.end_col.file - annotation.start_col.file;
let previous: String =
source_string.chars().take(annotation.start_col.file).skip(left).collect();
let underlined: String =
source_string.chars().skip(annotation.start_col.file).take(width).collect();
debug!(?previous, ?underlined);
let code_offset = code_offset
+ source_string
.chars()
.take(annotation.start_col.file)
.skip(left)
.map(|c| char_width(c))
.sum::<usize>();
let ann_width: usize = source_string
.chars()
.skip(annotation.start_col.file)
.take(width)
.map(|c| char_width(c))
.sum();
let ann_width = if ann_width == 0
&& matches!(annotation.annotation_type, AnnotationType::Singleline)
{
1
} else {
ann_width
};
for p in 0..ann_width {
// The default span label underline.
buffer.putc(
line_offset + 1,
(code_offset + p).saturating_sub(left),
uline.underline,
uline.style,
);
buffer.putc(line_offset + 1, code_offset + p, uline.underline, uline.style);
}

if pos == 0
Expand All @@ -1202,7 +1234,7 @@ impl HumanEmitter {
// The beginning of a multiline span with its leftward moving line on the same line.
buffer.putc(
line_offset + 1,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset,
match annotation.annotation_type {
AnnotationType::MultilineStart(_) => uline.top_right_flat,
AnnotationType::MultilineEnd(_) => uline.multiline_end_same_line,
Expand All @@ -1220,7 +1252,7 @@ impl HumanEmitter {
// so we start going down first.
buffer.putc(
line_offset + 1,
(code_offset + annotation.start_col.display).saturating_sub(left),
code_offset,
match annotation.annotation_type {
AnnotationType::MultilineStart(_) => uline.multiline_start_down,
AnnotationType::MultilineEnd(_) => uline.multiline_end_up,
Expand All @@ -1230,12 +1262,7 @@ impl HumanEmitter {
);
} else if pos != 0 && annotation.has_label() {
// The beginning of a span label with an actual label, we'll point down.
buffer.putc(
line_offset + 1,
(code_offset + annotation.start_col.display).saturating_sub(left),
uline.label_start,
uline.style,
);
buffer.putc(line_offset + 1, code_offset, uline.label_start, uline.style);
}
}

Expand Down Expand Up @@ -1718,17 +1745,11 @@ impl HumanEmitter {
// non-rustc_lexer::is_whitespace() chars are reported as an
// error (ex. no-break-spaces \u{a0}), and thus can't be considered
// for removal during error reporting.
// FIXME: doesn't account for '\t' properly.
let leading_whitespace = source_string
.chars()
.take_while(|c| rustc_lexer::is_whitespace(*c))
.map(|c| {
match c {
// Tabs are displayed as 4 spaces
'\t' => 4,
_ => 1,
}
})
.sum();
.count();
if source_string.chars().any(|c| !rustc_lexer::is_whitespace(c)) {
whitespace_margin = min(whitespace_margin, leading_whitespace);
}
Expand All @@ -1742,8 +1763,8 @@ impl HumanEmitter {
let mut span_left_margin = usize::MAX;
for line in &annotated_file.lines {
for ann in &line.annotations {
span_left_margin = min(span_left_margin, ann.start_col.display);
span_left_margin = min(span_left_margin, ann.end_col.display);
span_left_margin = min(span_left_margin, ann.start_col.file);
span_left_margin = min(span_left_margin, ann.end_col.file);
}
}
if span_left_margin == usize::MAX {
Expand All @@ -1763,12 +1784,12 @@ impl HumanEmitter {
.map_or(0, |s| s.len()),
);
for ann in &line.annotations {
span_right_margin = max(span_right_margin, ann.start_col.display);
span_right_margin = max(span_right_margin, ann.end_col.display);
span_right_margin = max(span_right_margin, ann.start_col.file);
span_right_margin = max(span_right_margin, ann.end_col.file);
// FIXME: account for labels not in the same line
let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1);
label_right_margin =
max(label_right_margin, ann.end_col.display + label_right);
max(label_right_margin, ann.end_col.file + label_right);
}
}

Expand Down
2 changes: 1 addition & 1 deletion tests/ui/codemap_tests/tab_2.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ error[E0765]: unterminated double quote string
LL | """;
| ___________________^
LL | | }
| |_^
| |__^

error: aborting due to 1 previous error

Expand Down
2 changes: 1 addition & 1 deletion tests/ui/diagnostic-width/long-span.long.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
error[E0308]: mismatched types
╭▸ $DIR/long-span.rs:7:15
│
LL │ …u8 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, …, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]…
LL │ …u8 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, …, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
╰╴ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━…━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ expected `u8`, found `[{integer}; 1680]`

error: aborting due to 1 previous error
Expand Down
2 changes: 1 addition & 1 deletion tests/ui/diagnostic-width/long-span.longest.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
error[E0308]: mismatched types
--> $DIR/long-span.rs:7:15
|
LL | ... = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,... 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...
LL | ... = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,... 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^...^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `u8`, found `[{integer}; 1680]`

error: aborting due to 1 previous error
Expand Down
2 changes: 1 addition & 1 deletion tests/ui/diagnostic-width/long-span.short.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
error[E0308]: mismatched types
╭▸ $DIR/long-span.rs:7:15
│
LL │ …u8 = [0, 0, 0…0]…
LL │ …u8 = [0, 0, 0…0];
╰╴ ━━━━━━━━…━━ expected `u8`, found `[{integer}; 1680]`

error: aborting due to 1 previous error
Expand Down
2 changes: 1 addition & 1 deletion tests/ui/diagnostic-width/long-span.shortest.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
error[E0308]: mismatched types
--> $DIR/long-span.rs:7:15
|
LL | ... = [0, 0, 0......
LL | ... = [0, 0, 0...0];
| ^^^^^^^^...^^ expected `u8`, found `[{integer}; 1680]`

error: aborting due to 1 previous error
Expand Down
Loading