diff --git a/go/loader/loader.go b/go/loader/loader.go
index 2a15359a..37181f26 100644
--- a/go/loader/loader.go
+++ b/go/loader/loader.go
@@ -460,6 +460,16 @@ func (prog *Program) InitialPackages() []*PackageInfo {
 	return infos
 }
 
+// FilePath returns the full path to the specified file.  It returns the empty
+// string if the file does not belong to one of this Program's packages.
+//
+func (prog *Program) FilePath(file *ast.File) string {
+	if f := prog.Fset.File(file.Package); f != nil {
+		return f.Name()
+	}
+	return ""
+}
+
 // ---------- Implementation ----------
 
 // importer holds the working state of the algorithm.