Index: utils/lit/lit/TestRunner.py
===================================================================
--- utils/lit/lit/TestRunner.py
+++ utils/lit/lit/TestRunner.py
@@ -700,11 +700,14 @@
     substitutions = []
     substitutions.extend([('%%', '#_MARKER_#')])
     substitutions.extend(test.config.substitutions)
+    tmpName = tmpBase + '.tmp'
+    baseName = os.path.basename(tmpBase)
     substitutions.extend([('%s', sourcepath),
                           ('%S', sourcedir),
                           ('%p', sourcedir),
                           ('%{pathsep}', os.pathsep),
-                          ('%t', tmpBase + '.tmp'),
+                          ('%t', tmpName),
+                          ('%basename', baseName),
                           ('%T', tmpDir),
                           ('#_MARKER_#', '%')])