Index: llvm/utils/lit/lit/LitConfig.py
===================================================================
--- llvm/utils/lit/lit/LitConfig.py
+++ llvm/utils/lit/lit/LitConfig.py
@@ -67,6 +67,28 @@
         self.parallelism_groups = parallelism_groups
         self.echo_all_commands = echo_all_commands
 
+        self._suite_setup_callbacks = []
+        self._suite_teardown_callbacks = []
+    
+    def __getstate__(self):
+        # An instance of LitConfig may be shared between multiple processes
+        # when using parallelism, which requires pickling that instance.
+        # However, pickling function objects is not always possible (or, in this
+        # case, always impossible), so we remove the callbacks from
+        # pickled instances.
+        # This is okay, because we only set them and run them in the parent
+        # lit.py process. Accessing them from subprocesses would be weird,
+        # so it's not supported.
+        state = dict(self.__dict__)
+        del state['_suite_setup_callbacks']
+        del state['_suite_teardown_callbacks']
+        return state
+
+    def __setstate__(self, state):
+        self.__dict__.update(state)
+        self._suite_setup_callbacks = []
+        self._suite_teardown_callbacks = []
+
     @property
     def maxIndividualTestTime(self):
         """
@@ -159,6 +181,42 @@
             self.bashPath = ''
 
         return dir
+    
+    def suite_setup(self, callback):
+        '''
+        Adds the callback to the list of setup callbacks that will be run
+        before running the test suite.
+
+        Can be used as a decorator in lit configuration files like this:
+
+            @lit_config.suite_setup
+            def setup():
+                ...
+        '''
+        self._suite_setup_callbacks.append(callback)
+        return callback
+    
+    def suite_teardown(self, callback):
+        '''
+        Adds the callback to the list of teardown callbacks that will be run
+        after the test suite completes.
+
+        Can be used as a decorator in lit configuration files like this:
+
+            @lit_config.suite_teardown
+            def teardown():
+                ...
+        '''
+        self._suite_teardown_callbacks.append(callback)
+        return callback
+    
+    def run_suite_setup_callbacks(self):
+        for callback in self._suite_setup_callbacks:
+            callback()
+    
+    def run_suite_teardown_callbacks(self):
+        for callback in self._suite_teardown_callbacks:
+            callback()
 
     def _write_message(self, kind, message):
         # Get the file/line where this message was generated.
Index: llvm/utils/lit/lit/run.py
===================================================================
--- llvm/utils/lit/lit/run.py
+++ llvm/utils/lit/lit/run.py
@@ -58,12 +58,19 @@
         timeout = self.timeout or one_week
         deadline = time.time() + timeout
 
-        self._execute(deadline)
+        try:
+            self.lit_config.run_suite_setup_callbacks()
+            self._execute(deadline)
+        finally:
+            self.lit_config.run_suite_teardown_callbacks()
 
         # Mark any tests that weren't run as UNRESOLVED.
         for test in self.tests:
             if test.result is None:
                 test.setResult(lit.Test.Result(lit.Test.UNRESOLVED, '', 0.0))
+    
+    def _execute(self, deadline):
+        raise NotImplementedError("Should be implemented in a subclass")
 
     # TODO(yln): as the comment says.. this is racing with the main thread waiting
     # for results
Index: llvm/utils/lit/tests/Inputs/setup-teardown/lit.cfg
===================================================================
--- /dev/null
+++ llvm/utils/lit/tests/Inputs/setup-teardown/lit.cfg
@@ -0,0 +1,14 @@
+import lit.formats
+config.name = 'setup-teardown'
+config.suffixes = ['.txt']
+config.test_format = lit.formats.ShTest()
+config.test_source_root = None
+config.test_exec_root = None
+
+@lit_config.suite_setup
+def setup():
+    print("Running setup code...")
+
+@lit_config.suite_teardown
+def teardown():
+    print("Running teardown code...")
Index: llvm/utils/lit/tests/Inputs/setup-teardown/test1.txt
===================================================================
--- /dev/null
+++ llvm/utils/lit/tests/Inputs/setup-teardown/test1.txt
@@ -0,0 +1 @@
+# RUN: true
Index: llvm/utils/lit/tests/Inputs/setup-teardown/test2.txt
===================================================================
--- /dev/null
+++ llvm/utils/lit/tests/Inputs/setup-teardown/test2.txt
@@ -0,0 +1 @@
+# RUN: false
Index: llvm/utils/lit/tests/setup-teardown.py
===================================================================
--- /dev/null
+++ llvm/utils/lit/tests/setup-teardown.py
@@ -0,0 +1,9 @@
+# RUN: not %{lit} -j1 %{inputs}/setup-teardown | FileCheck %s
+
+# CHECK: -- Testing: 2 tests, 1 workers --
+# CHECK: Running setup code...
+# CHECK: PASS: setup-teardown :: test1.txt
+# CHECK: FAIL: setup-teardown :: test2.txt
+# CHECK: Running teardown code...
+# CHECK: Expected Passes    : 1
+# CHECK: Unexpected Failures: 1