Index: lldb/trunk/include/lldb/Target/Target.h
===================================================================
--- lldb/trunk/include/lldb/Target/Target.h
+++ lldb/trunk/include/lldb/Target/Target.h
@@ -126,6 +126,8 @@
 
   FileSpecList &GetDebugFileSearchPaths();
 
+  FileSpec &GetClangModulesCachePath();
+
   FileSpecList &GetClangModuleSearchPaths();
 
   bool GetEnableAutoImportClangModules() const;
Index: lldb/trunk/packages/Python/lldbsuite/test/lldbtest.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/lldbtest.py
+++ lldb/trunk/packages/Python/lldbsuite/test/lldbtest.py
@@ -1914,6 +1914,14 @@
         # decorators.
         Base.setUp(self)
 
+        # Set the clang modules cache path.
+        if self.child:
+            assert(self.getDebugInfo() == 'default')
+            mod_cache = os.path.join(self.getBuildDir(), "module-cache")
+            self.runCmd("settings set target.clang-modules-cache-path "
+                        + mod_cache)
+
+
         if "LLDB_MAX_LAUNCH_COUNT" in os.environ:
             self.maxLaunchCount = int(os.environ["LLDB_MAX_LAUNCH_COUNT"])
 
Index: lldb/trunk/packages/Python/lldbsuite/test/macosx/nslog/TestDarwinNSLogOutput.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/macosx/nslog/TestDarwinNSLogOutput.py
+++ lldb/trunk/packages/Python/lldbsuite/test/macosx/nslog/TestDarwinNSLogOutput.py
@@ -15,21 +15,20 @@
 import sys
 
 from lldbsuite.test.decorators import *
-from lldbsuite.test import lldbtest
+from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbtest_config
 
 
-class DarwinNSLogOutputTestCase(lldbtest.TestBase):
+class DarwinNSLogOutputTestCase(TestBase):
     NO_DEBUG_INFO_TESTCASE = True
-
-    mydir = lldbtest.TestBase.compute_mydir(__file__)
+    mydir = TestBase.compute_mydir(__file__)
 
     @skipUnlessDarwin
     @skipIfRemote   # this test is currently written using lldb commands & assumes running on local system
 
     def setUp(self):
         # Call super's setUp().
-        super(DarwinNSLogOutputTestCase, self).setUp()
+        TestBase.setUp(self)
         self.child = None
         self.child_prompt = '(lldb) '
         self.strict_sources = False
@@ -42,7 +41,7 @@
         self.d = {'OBJC_SOURCES': self.source, 'EXE': self.exe_name}
 
         # Locate breakpoint.
-        self.line = lldbtest.line_number(self.source, '// break here')
+        self.line = line_number(self.source, '// break here')
 
     def tearDown(self):
         # Shut down the process if it's still running.
Index: lldb/trunk/source/Plugins/ExpressionParser/Clang/CMakeLists.txt
===================================================================
--- lldb/trunk/source/Plugins/ExpressionParser/Clang/CMakeLists.txt
+++ lldb/trunk/source/Plugins/ExpressionParser/Clang/CMakeLists.txt
@@ -23,6 +23,7 @@
   LINK_LIBS
     clangAST
     clangCodeGen
+    clangDriver
     clangEdit
     clangFrontend
     clangLex
Index: lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp
===================================================================
--- lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp
+++ lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.cpp
@@ -13,6 +13,7 @@
 
 // Other libraries and framework includes
 #include "clang/Basic/TargetInfo.h"
+#include "clang/Driver/Driver.h"
 #include "clang/Frontend/CompilerInstance.h"
 #include "clang/Frontend/FrontendActions.h"
 #include "clang/Lex/Preprocessor.h"
@@ -590,14 +591,12 @@
   // Add additional search paths with { "-I", path } or { "-F", path } here.
 
   {
-    llvm::SmallString<128> DefaultModuleCache;
-    const bool erased_on_reboot = false;
-    llvm::sys::path::system_temp_directory(erased_on_reboot,
-                                           DefaultModuleCache);
-    llvm::sys::path::append(DefaultModuleCache, "org.llvm.clang");
-    llvm::sys::path::append(DefaultModuleCache, "ModuleCache");
+    llvm::SmallString<128> Path;
+    target.GetClangModulesCachePath().GetPath(Path);
+    if (Path.empty())
+      clang::driver::Driver::getDefaultModuleCachePath(Path);
     std::string module_cache_argument("-fmodules-cache-path=");
-    module_cache_argument.append(DefaultModuleCache.str().str());
+    module_cache_argument.append(Path.str());
     compiler_invocation_arguments.push_back(module_cache_argument);
   }
 
Index: lldb/trunk/source/Target/Target.cpp
===================================================================
--- lldb/trunk/source/Target/Target.cpp
+++ lldb/trunk/source/Target/Target.cpp
@@ -3509,6 +3509,9 @@
      OptionValue::eTypeString, nullptr, nullptr,
      "A list of trap handler function names, e.g. a common Unix user process "
      "one is _sigtramp."},
+    {"clang-modules-cache-path",
+     OptionValue::eTypeFileSpec, false, 0, nullptr, nullptr,
+     "The path to the clang modules cache directory (-fmodules-cache-path)."},
     {"display-runtime-support-values", OptionValue::eTypeBoolean, false, false,
      nullptr, nullptr, "If true, LLDB will show variables that are meant to "
                        "support the operation of a language's runtime "
@@ -3558,6 +3561,7 @@
   ePropertyMemoryModuleLoadLevel,
   ePropertyDisplayExpressionsInCrashlogs,
   ePropertyTrapHandlerNames,
+  ePropertyClangModulesCachePath,
   ePropertyDisplayRuntimeSupportValues,
   ePropertyNonStopModeEnabled,
   ePropertyExperimental
@@ -3937,6 +3941,15 @@
   return option_value->GetCurrentValue();
 }
 
+FileSpec &TargetProperties::GetClangModulesCachePath() {
+  const uint32_t idx = ePropertyClangModulesCachePath;
+  OptionValueFileSpec *option_value =
+      m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpec(nullptr, false,
+                                                               idx);
+  assert(option_value);
+  return option_value->GetCurrentValue();
+}
+
 FileSpecList &TargetProperties::GetClangModuleSearchPaths() {
   const uint32_t idx = ePropertyClangModuleSearchPaths;
   OptionValueFileSpecList *option_value =