1 files changed, 22 insertions, 3 deletions
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index cef4c6f79..7e61f2f9f 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -259,6 +259,10 @@ impl RealFileName {
             FileNameDisplayPreference::Remapped => {
                 self.remapped_path_if_available().to_string_lossy()
             }
+            FileNameDisplayPreference::Short => self
+                .local_path_if_available()
+                .file_name()
+                .map_or_else(|| "".into(), |f| f.to_string_lossy()),
         }
     }
 }
@@ -302,6 +306,9 @@ pub enum FileNameDisplayPreference {
     /// Display the path before the application of rewrite rules provided via `--remap-path-prefix`.
     /// This is appropriate for use in user-facing output (such as diagnostics).
     Local,
+    /// Display only the filename, as a way to reduce the verbosity of the output.
+    /// This is appropriate for use in user-facing output (such as diagnostics).
+    Short,
 }
 
 pub struct FileNameDisplay<'a> {
@@ -322,7 +329,7 @@ impl fmt::Display for FileNameDisplay<'_> {
             ProcMacroSourceCode(_) => write!(fmt, "<proc-macro source code>"),
             CfgSpec(_) => write!(fmt, "<cfgspec>"),
             CliCrateAttr(_) => write!(fmt, "<crate attribute>"),
-            Custom(ref s) => write!(fmt, "<{}>", s),
+            Custom(ref s) => write!(fmt, "<{s}>"),
             DocTest(ref path, _) => write!(fmt, "{}", path.display()),
             InlineAsm(_) => write!(fmt, "<inline asm>"),
         }
@@ -491,6 +498,10 @@ impl SpanData {
     pub fn is_dummy(self) -> bool {
         self.lo.0 == 0 && self.hi.0 == 0
     }
+    #[inline]
+    pub fn is_visible(self, sm: &SourceMap) -> bool {
+        !self.is_dummy() && sm.is_span_accessible(self.span())
+    }
     /// Returns `true` if `self` fully encloses `other`.
     pub fn contains(self, other: Self) -> bool {
         self.lo <= other.lo && other.hi <= self.hi
@@ -556,6 +567,11 @@ impl Span {
         self.data_untracked().is_dummy()
     }
 
+    #[inline]
+    pub fn is_visible(self, sm: &SourceMap) -> bool {
+        self.data_untracked().is_visible(sm)
+    }
+
     /// Returns `true` if this span comes from any kind of macro, desugaring or inlining.
     #[inline]
     pub fn from_expansion(self) -> bool {
@@ -780,6 +796,9 @@ impl Span {
 
     /// Returns a `Span` that would enclose both `self` and `end`.
     ///
+    /// Note that this can also be used to extend the span "backwards":
+    /// `start.to(end)` and `end.to(start)` return the same `Span`.
+    ///
     /// ```text
     ///     ____             ___
     ///     self lorem ipsum end
@@ -1055,7 +1074,7 @@ impl NonNarrowChar {
             0 => NonNarrowChar::ZeroWidth(pos),
             2 => NonNarrowChar::Wide(pos),
             4 => NonNarrowChar::Tab(pos),
-            _ => panic!("width {} given for non-narrow character", width),
+            _ => panic!("width {width} given for non-narrow character"),
         }
     }
 
@@ -1372,7 +1391,7 @@ impl<S: Encoder> Encodable<S> for SourceFile {
                     4 => {
                         raw_diffs = Vec::with_capacity(bytes_per_diff * num_diffs);
                         for diff in diff_iter {
-                            raw_diffs.extend_from_slice(&(diff.0 as u32).to_le_bytes());
+                            raw_diffs.extend_from_slice(&(diff.0).to_le_bytes());
                         }
                     }
                     _ => unreachable!(),