Canonicalize file path when creating a FileName::Real

Author: LeSeulArtichaut

src/librustc_interface/passes.rs

@@ -557,13 +557,13 @@ fn write_out_deps(
                 for cnum in resolver.cstore().crates_untracked() {
                     let source = resolver.cstore().crate_source_untracked(cnum);
                     if let Some((path, _)) = source.dylib {
-                        files.push(escape_dep_filename(&FileName::Real(path)));
+                        files.push(escape_dep_filename(&path.into()));
                     }
                     if let Some((path, _)) = source.rlib {
-                        files.push(escape_dep_filename(&FileName::Real(path)));
+                        files.push(escape_dep_filename(&path.into()));
                     }
                     if let Some((path, _)) = source.rmeta {
-                        files.push(escape_dep_filename(&FileName::Real(path)));
+                        files.push(escape_dep_filename(&path.into()));
                     }
                 }
             });

src/librustc_span/lib.rs

@@ -123,7 +123,11 @@ impl std::fmt::Display for FileName {
 impl From<PathBuf> for FileName {
     fn from(p: PathBuf) -> Self {
         assert!(!p.to_string_lossy().ends_with('>'));
-        FileName::Real(p)
+        if cfg!(not(windows)) {
+            FileName::Real(p.canonlicalize().unwrap_or(p))
+        } else {
+            FileName::Real(p)
+        }
     }
 }