Index: utils/lit/lit/LitConfig.py
===================================================================
--- utils/lit/lit/LitConfig.py
+++ utils/lit/lit/LitConfig.py
@@ -21,7 +21,7 @@
     def __init__(self, progname, path, quiet,
                  useQEMU, qemuArgs, useValgrind, valgrindLeakCheck, valgrindArgs,
                  noExecute, debug, isWindows,
-                 params, config_prefix = None):
+                 params, config_prefix = None, timeout = None):
         # The name of the test runner.
         self.progname = progname
         # The items to add to the PATH environment variable.
@@ -63,6 +63,7 @@
                 self.valgrindArgs.append('--leak-check=no')
             self.valgrindArgs.extend(self.valgrindUserArgs)
 
+        self.timeout = timeout
 
     def load_config(self, config, path):
         """load_config(config, path) - Load a config object from an alternate
Index: utils/lit/lit/TestRunner.py
===================================================================
--- utils/lit/lit/TestRunner.py
+++ utils/lit/lit/TestRunner.py
@@ -305,7 +305,8 @@
             command = litConfig.valgrindArgs + command
 
     return lit.util.executeCommand(command, cwd=cwd,
-                                   env=test.config.environment)
+                                   env=test.config.environment,
+                                   timeout=litConfig.timeout)
 
 def parseIntegratedTestScriptCommands(source_path):
     """
Index: utils/lit/lit/formats/base.py
===================================================================
--- utils/lit/lit/formats/base.py
+++ utils/lit/lit/formats/base.py
@@ -101,7 +101,7 @@
         else:
             cmd.append(test.getSourcePath())
 
-        out, err, exitCode = lit.util.executeCommand(cmd)
+        out, err, exitCode = lit.util.executeCommand(cmd, timeout=litConfig.timeout)
 
         diags = out + err
         if not exitCode and not diags.strip():
Index: utils/lit/lit/main.py
===================================================================
--- utils/lit/lit/main.py
+++ utils/lit/lit/main.py
@@ -214,6 +214,9 @@
     group.add_option("", "--max-time", dest="maxTime", metavar="N",
                      help="Maximum time to spend testing (in seconds)",
                      action="store", type=float, default=None)
+    group.add_option("", "--timeout", dest="timeout", metavar="N",
+                     help="Maximum time to spend in any given test (in seconds)",
+                     action="store", type=float, default=None)
     group.add_option("", "--shuffle", dest="shuffle",
                      help="Run tests in random order",
                      action="store_true", default=False)
@@ -289,7 +292,8 @@
         debug = opts.debug,
         isWindows = isWindows,
         params = userParams,
-        config_prefix = opts.configPrefix)
+        config_prefix = opts.configPrefix,
+        timeout = opts.timeout)
 
     # Perform test discovery.
     run = lit.run.Run(litConfig,
Index: utils/lit/lit/util.py
===================================================================
--- utils/lit/lit/util.py
+++ utils/lit/lit/util.py
@@ -6,7 +6,10 @@
 import signal
 import subprocess
 import sys
+import threading
 
+import Test
+
 def detectCPUs():
     """
     Detects the number of CPUs on a system. Cribbed from pp.
@@ -143,15 +146,46 @@
 # Close extra file handles on UNIX (on Windows this cannot be done while
 # also redirecting input).
 kUseCloseFDs = not (platform.system() == 'Windows')
-def executeCommand(command, cwd=None, env=None):
+def executeCommand(command, cwd=None, env=None, timeout=None):
     p = subprocess.Popen(command, cwd=cwd,
                          stdin=subprocess.PIPE,
                          stdout=subprocess.PIPE,
                          stderr=subprocess.PIPE,
                          env=env, close_fds=kUseCloseFDs)
+
+    class Watchdog(object):
+        def __init__(self, popen, timeout):
+            self.timeout_tripped = False
+            self.timer = None
+            if timeout is not None:
+                def timeout_handler():
+                    try:
+                        popen.kill()
+                    except OSError, e:
+                        # The Popen already terminated before the watchdog
+                        # got acqauinted with it. Too bad they couldn't be
+                        # friends
+                        pass
+                    self.timeout_tripped = True
+                timer = threading.Timer(timeout, timeout_handler)
+                timer.start()
+
+        def cancel(self):
+            if self.timer is not None:
+                self.timer.cancel()
+
+        def timed_out(self):
+            return self.timeout_tripped
+
+    wd = Watchdog(p, timeout)
+
     out,err = p.communicate()
     exitCode = p.wait()
 
+    if wd.timed_out():
+      err += 'Test timed out after %d seconds\n' % (timeout)
+    wd.cancel()
+
     # Detect Ctrl-C in subprocess.
     if exitCode == -signal.SIGINT:
         raise KeyboardInterrupt