On short error format, append primary span label to message

The `error-format=short` output only displays the path, error code and
main error message all in the same line. We now add the primary span label
as well after the error message, to provide more context.

1 files changed, 21 insertions, 1 deletions

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 8963b009c31..c22375795e5 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1346,10 +1346,11 @@ impl HumanEmitter {
                 buffer.append(0, ": ", header_style);
                 label_width += 2;
             }
+            let mut line = 0;
             for (text, _) in msgs.iter() {
                 let text = self.translate_message(text, args).map_err(Report::new).unwrap();
                 // Account for newlines to align output to its label.
-                for (line, text) in normalize_whitespace(&text).lines().enumerate() {
+                for text in normalize_whitespace(&text).lines() {
                     buffer.append(
                         line,
                         &format!(
@@ -1359,6 +1360,25 @@ impl HumanEmitter {
                         ),
                         header_style,
                     );
+                    line += 1;
+                }
+            }
+            if self.short_message {
+                let labels = msp
+                    .span_labels()
+                    .into_iter()
+                    .filter_map(|label| match label.label {
+                        Some(msg) if label.is_primary => {
+                            let text = self.translate_message(&msg, args).ok()?;
+                            if !text.trim().is_empty() { Some(text.to_string()) } else { None }
+                        }
+                        _ => None,
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                if !labels.is_empty() {
+                    buffer.append(line, ": ", Style::NoStyle);
+                    buffer.append(line, &labels, Style::NoStyle);
                 }
             }
         }