Deduplicate lines in long const-eval stack trace

This commit is contained in:
Michael Goulet 2022-01-11 17:55:56 -08:00
parent cfa4ac66c1
commit 73ad8df70d
3 changed files with 71 additions and 1 deletions

View file

@ -156,9 +156,37 @@ impl<'tcx> ConstEvalErr<'tcx> {
}
// Add spans for the stacktrace. Don't print a single-line backtrace though.
if self.stacktrace.len() > 1 {
// Helper closure to print duplicated lines.
let mut flush_last_line = |last_frame, times| {
if let Some((line, span)) = last_frame {
err.span_label(span, &line);
// Don't print [... additional calls ...] if the number of lines is small
if times < 3 {
for _ in 0..times {
err.span_label(span, &line);
}
} else {
err.span_label(
span,
format!("[... {} additional calls {} ...]", times, &line),
);
}
}
};
let mut last_frame = None;
let mut times = 0;
for frame_info in &self.stacktrace {
err.span_label(frame_info.span, frame_info.to_string());
let frame = (frame_info.to_string(), frame_info.span);
if last_frame.as_ref() == Some(&frame) {
times += 1;
} else {
flush_last_line(last_frame, times);
last_frame = Some(frame);
times = 0;
}
}
flush_last_line(last_frame, times);
}
// Let the caller finish the job.
emit(err)