1 files changed, 28 insertions, 10 deletions
diff --git a/src/librustc_span/source_map.rs b/src/librustc_span/source_map.rs
index 49e2144b3e3..54d3dc2c867 100644
--- a/src/librustc_span/source_map.rs
+++ b/src/librustc_span/source_map.rs
@@ -98,6 +98,8 @@ impl FileLoader for RealFileLoader {
 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug)]
 pub struct StableSourceFileId(u128);
 
+// FIXME: we need a more globally consistent approach to the problem solved by
+// StableSourceFileId, perhaps built atop source_file.name_hash.
 impl StableSourceFileId {
     pub fn new(source_file: &SourceFile) -> StableSourceFileId {
         StableSourceFileId::new_from_pieces(
@@ -107,14 +109,21 @@ impl StableSourceFileId {
         )
     }
 
-    pub fn new_from_pieces(
+    fn new_from_pieces(
         name: &FileName,
         name_was_remapped: bool,
         unmapped_path: Option<&FileName>,
     ) -> StableSourceFileId {
         let mut hasher = StableHasher::new();
 
-        name.hash(&mut hasher);
+        if let FileName::Real(real_name) = name {
+            // rust-lang/rust#70924: Use the stable (virtualized) name when
+            // available. (We do not want artifacts from transient file system
+            // paths for libstd to leak into our build artifacts.)
+            real_name.stable_name().hash(&mut hasher)
+        } else {
+            name.hash(&mut hasher);
+        }
         name_was_remapped.hash(&mut hasher);
         unmapped_path.hash(&mut hasher);
 
@@ -247,7 +256,7 @@ impl SourceMap {
 
     fn try_new_source_file(
         &self,
-        filename: FileName,
+        mut filename: FileName,
         src: String,
     ) -> Result<Lrc<SourceFile>, OffsetOverflowError> {
         // The path is used to determine the directory for loading submodules and
@@ -257,13 +266,22 @@ impl SourceMap {
         // be empty, so the working directory will be used.
         let unmapped_path = filename.clone();
 
-        let (filename, was_remapped) = match filename {
-            FileName::Real(filename) => {
-                let (filename, was_remapped) = self.path_mapping.map_prefix(filename);
-                (FileName::Real(filename), was_remapped)
+        let was_remapped;
+        if let FileName::Real(real_filename) = &mut filename {
+            match real_filename {
+                RealFileName::Named(path_to_be_remapped)
+                | RealFileName::Devirtualized {
+                    local_path: path_to_be_remapped,
+                    virtual_name: _,
+                } => {
+                    let mapped = self.path_mapping.map_prefix(path_to_be_remapped.clone());
+                    was_remapped = mapped.1;
+                    *path_to_be_remapped = mapped.0;
+                }
             }
-            other => (other, false),
-        };
+        } else {
+            was_remapped = false;
+        }
 
         let file_id =
             StableSourceFileId::new_from_pieces(&filename, was_remapped, Some(&unmapped_path));
@@ -1001,7 +1019,7 @@ impl SourceMap {
     }
     pub fn ensure_source_file_source_present(&self, source_file: Lrc<SourceFile>) -> bool {
         source_file.add_external_src(|| match source_file.name {
-            FileName::Real(ref name) => self.file_loader.read_file(name).ok(),
+            FileName::Real(ref name) => self.file_loader.read_file(name.local_path()).ok(),
             _ => None,
         })
     }