1 files changed, 10 insertions, 1 deletions
diff --git a/lldb/lit/lit.cfg.py b/lldb/lit/lit.cfg.py
index 9b78ba35c16..86cc9022101 100644
--- a/lldb/lit/lit.cfg.py
+++ b/lldb/lit/lit.cfg.py
@@ -4,9 +4,9 @@ import os
 import sys
 import re
 import platform
+import shutil
 import subprocess
 
-
 import lit.util
 import lit.formats
 from lit.llvm import llvm_config
@@ -124,3 +124,12 @@ llvm_config.feature_config(
      ('--build-mode', {'DEBUG': 'debug'}),
      ('--targets-built', calculate_arch_features)
      ])
+
+# Clean the module caches in the test build directory.  This is
+# necessary in an incremental build whenever clang changes underneath,
+# so doing it once per lit.py invocation is close enough.
+for i in ['module-cache-clang']:
+    cachedir = os.path.join(config.llvm_obj_root, 'lldb-test-build.noindex', i)
+    if os.path.isdir(cachedir):
+        print("Deleting module cache at %s."%cachedir)
+        shutil.rmtree(cachedir)