New upstream version 1.62.1+dfsg1

[rustc.git] / compiler / rustc_span / src / source_map.rs

diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs
index 95177102dcf8678df118ab6d58cc65750219d8be..505c0af953af1e85e0921b636bb35ef799848162 100644 (file)
--- a/compiler/rustc_span/src/source_map.rs
+++ b/compiler/rustc_span/src/source_map.rs
@@ -1058,10 +1058,11 @@ impl SourceMap {
 
     /// Tries to find the span of the semicolon of a macro call statement.
     /// The input must be the *call site* span of a statement from macro expansion.
-    ///
-    ///           v output
-    ///     mac!();
-    ///     ^^^^^^ input
+    /// ```ignore (illustrative)
+    /// //       v output
+    ///    mac!();
+    /// // ^^^^^^ input
+    /// ```
     pub fn mac_call_stmt_semi_span(&self, mac_call: Span) -> Option<Span> {
         let span = self.span_extend_while(mac_call, char::is_whitespace).ok()?;
         let span = span.shrink_to_hi().with_hi(BytePos(span.hi().0.checked_add(1)?));
@@ -1102,7 +1103,19 @@ impl FilePathMapping {
         //       take precedence.
         for &(ref from, ref to) in self.mapping.iter().rev() {
             if let Ok(rest) = path.strip_prefix(from) {
-                return (to.join(rest), true);
+                let remapped = if rest.as_os_str().is_empty() {
+                    // This is subtle, joining an empty path onto e.g. `foo/bar` will
+                    // result in `foo/bar/`, that is, there'll be an additional directory
+                    // separator at the end. This can lead to duplicated directory separators
+                    // in remapped paths down the line.
+                    // So, if we have an exact match, we just return that without a call
+                    // to `Path::join()`.
+                    to.clone()
+                } else {
+                    to.join(rest)
+                };
+
+                return (remapped, true);
             }
         }