diff --git a/utils/lit/LitConfig.py b/utils/lit/LitConfig.py
new file mode 100644
index 0000000..4fb0ccc
--- /dev/null
+++ b/utils/lit/LitConfig.py
@@ -0,0 +1,71 @@
+class LitConfig:
+    """LitConfig - Configuration data for a 'lit' test runner instance, shared
+    across all tests.
+
+    The LitConfig object is also used to communicate with client configuration
+    files, it is always passed in as the global variable 'lit' so that
+    configuration files can access common functionality and internal components
+    easily.
+    """
+
+    # Provide access to built-in formats.
+    import LitFormats as formats
+
+    # Provide access to built-in utility functions.
+    import Util as util
+
+    def __init__(self, progname, path, quiet,
+                 useValgrind, valgrindArgs,
+                 useTclAsSh,
+                 noExecute, debug, isWindows):
+        # The name of the test runner.
+        self.progname = progname
+        # The items to add to the PATH environment variable.
+        self.path = list(map(str, path))
+        self.quiet = bool(quiet)
+        self.useValgrind = bool(useValgrind)
+        self.valgrindArgs = list(valgrindArgs)
+        self.useTclAsSh = bool(useTclAsSh)
+        self.noExecute = noExecute
+        self.debug = debug
+        self.isWindows = bool(isWindows)
+
+        self.numErrors = 0
+        self.numWarnings = 0
+
+    def load_config(self, config, path):
+        """load_config(config, path) - Load a config object from an alternate
+        path."""
+        from TestingConfig import TestingConfig
+        return TestingConfig.frompath(path, config.parent, self,
+                                      mustExist = True,
+                                      config = config)
+
+    def _write_message(self, kind, message):
+        import inspect, os, sys
+
+        # Get the file/line where this message was generated.
+        f = inspect.currentframe()
+        # Step out of _write_message, and then out of wrapper.
+        f = f.f_back.f_back
+        file,line,_,_,_ = inspect.getframeinfo(f)
+        location = '%s:%d' % (os.path.basename(file), line)
+
+        print >>sys.stderr, '%s: %s: %s: %s' % (self.progname, location,
+                                                kind, message)
+
+    def note(self, message):
+        self._write_message('note', message)
+
+    def warning(self, message):
+        self._write_message('warning', message)
+        self.numWarnings += 1
+
+    def error(self, message):
+        self._write_message('error', message)
+        self.numErrors += 1
+
+    def fatal(self, message):
+        import sys
+        self._write_message('fatal', message)
+        sys.exit(2)
diff --git a/utils/lit/LitFormats.py b/utils/lit/LitFormats.py
new file mode 100644
index 0000000..cc00ddc
--- /dev/null
+++ b/utils/lit/LitFormats.py
@@ -0,0 +1,2 @@
+from ShTest import ShTest
+from TclTest import TclTest
diff --git a/utils/lit/ProgressBar.py b/utils/lit/ProgressBar.py
new file mode 100644
index 0000000..85c95f5
--- /dev/null
+++ b/utils/lit/ProgressBar.py
@@ -0,0 +1,267 @@
+#!/usr/bin/env python
+
+# Source: http://code.activestate.com/recipes/475116/, with
+# modifications by Daniel Dunbar.
+
+import sys, re, time
+
+class TerminalController:
+    """
+    A class that can be used to portably generate formatted output to
+    a terminal.  
+    
+    `TerminalController` defines a set of instance variables whose
+    values are initialized to the control sequence necessary to
+    perform a given action.  These can be simply included in normal
+    output to the terminal:
+
+        >>> term = TerminalController()
+        >>> print 'This is '+term.GREEN+'green'+term.NORMAL
+
+    Alternatively, the `render()` method can used, which replaces
+    '${action}' with the string required to perform 'action':
+
+        >>> term = TerminalController()
+        >>> print term.render('This is ${GREEN}green${NORMAL}')
+
+    If the terminal doesn't support a given action, then the value of
+    the corresponding instance variable will be set to ''.  As a
+    result, the above code will still work on terminals that do not
+    support color, except that their output will not be colored.
+    Also, this means that you can test whether the terminal supports a
+    given action by simply testing the truth value of the
+    corresponding instance variable:
+
+        >>> term = TerminalController()
+        >>> if term.CLEAR_SCREEN:
+        ...     print 'This terminal supports clearning the screen.'
+
+    Finally, if the width and height of the terminal are known, then
+    they will be stored in the `COLS` and `LINES` attributes.
+    """
+    # Cursor movement:
+    BOL = ''             #: Move the cursor to the beginning of the line
+    UP = ''              #: Move the cursor up one line
+    DOWN = ''            #: Move the cursor down one line
+    LEFT = ''            #: Move the cursor left one char
+    RIGHT = ''           #: Move the cursor right one char
+
+    # Deletion:
+    CLEAR_SCREEN = ''    #: Clear the screen and move to home position
+    CLEAR_EOL = ''       #: Clear to the end of the line.
+    CLEAR_BOL = ''       #: Clear to the beginning of the line.
+    CLEAR_EOS = ''       #: Clear to the end of the screen
+
+    # Output modes:
+    BOLD = ''            #: Turn on bold mode
+    BLINK = ''           #: Turn on blink mode
+    DIM = ''             #: Turn on half-bright mode
+    REVERSE = ''         #: Turn on reverse-video mode
+    NORMAL = ''          #: Turn off all modes
+
+    # Cursor display:
+    HIDE_CURSOR = ''     #: Make the cursor invisible
+    SHOW_CURSOR = ''     #: Make the cursor visible
+
+    # Terminal size:
+    COLS = None          #: Width of the terminal (None for unknown)
+    LINES = None         #: Height of the terminal (None for unknown)
+
+    # Foreground colors:
+    BLACK = BLUE = GREEN = CYAN = RED = MAGENTA = YELLOW = WHITE = ''
+    
+    # Background colors:
+    BG_BLACK = BG_BLUE = BG_GREEN = BG_CYAN = ''
+    BG_RED = BG_MAGENTA = BG_YELLOW = BG_WHITE = ''
+    
+    _STRING_CAPABILITIES = """
+    BOL=cr UP=cuu1 DOWN=cud1 LEFT=cub1 RIGHT=cuf1
+    CLEAR_SCREEN=clear CLEAR_EOL=el CLEAR_BOL=el1 CLEAR_EOS=ed BOLD=bold
+    BLINK=blink DIM=dim REVERSE=rev UNDERLINE=smul NORMAL=sgr0
+    HIDE_CURSOR=cinvis SHOW_CURSOR=cnorm""".split()
+    _COLORS = """BLACK BLUE GREEN CYAN RED MAGENTA YELLOW WHITE""".split()
+    _ANSICOLORS = "BLACK RED GREEN YELLOW BLUE MAGENTA CYAN WHITE".split()
+
+    def __init__(self, term_stream=sys.stdout):
+        """
+        Create a `TerminalController` and initialize its attributes
+        with appropriate values for the current terminal.
+        `term_stream` is the stream that will be used for terminal
+        output; if this stream is not a tty, then the terminal is
+        assumed to be a dumb terminal (i.e., have no capabilities).
+        """
+        # Curses isn't available on all platforms
+        try: import curses
+        except: return
+
+        # If the stream isn't a tty, then assume it has no capabilities.
+        if not term_stream.isatty(): return
+
+        # Check the terminal type.  If we fail, then assume that the
+        # terminal has no capabilities.
+        try: curses.setupterm()
+        except: return
+
+        # Look up numeric capabilities.
+        self.COLS = curses.tigetnum('cols')
+        self.LINES = curses.tigetnum('lines')
+        
+        # Look up string capabilities.
+        for capability in self._STRING_CAPABILITIES:
+            (attrib, cap_name) = capability.split('=')
+            setattr(self, attrib, self._tigetstr(cap_name) or '')
+
+        # Colors
+        set_fg = self._tigetstr('setf')
+        if set_fg:
+            for i,color in zip(range(len(self._COLORS)), self._COLORS):
+                setattr(self, color, curses.tparm(set_fg, i) or '')
+        set_fg_ansi = self._tigetstr('setaf')
+        if set_fg_ansi:
+            for i,color in zip(range(len(self._ANSICOLORS)), self._ANSICOLORS):
+                setattr(self, color, curses.tparm(set_fg_ansi, i) or '')
+        set_bg = self._tigetstr('setb')
+        if set_bg:
+            for i,color in zip(range(len(self._COLORS)), self._COLORS):
+                setattr(self, 'BG_'+color, curses.tparm(set_bg, i) or '')
+        set_bg_ansi = self._tigetstr('setab')
+        if set_bg_ansi:
+            for i,color in zip(range(len(self._ANSICOLORS)), self._ANSICOLORS):
+                setattr(self, 'BG_'+color, curses.tparm(set_bg_ansi, i) or '')
+
+    def _tigetstr(self, cap_name):
+        # String capabilities can include "delays" of the form "$<2>".
+        # For any modern terminal, we should be able to just ignore
+        # these, so strip them out.
+        import curses
+        cap = curses.tigetstr(cap_name) or ''
+        return re.sub(r'\$<\d+>[/*]?', '', cap)
+
+    def render(self, template):
+        """
+        Replace each $-substitutions in the given template string with
+        the corresponding terminal control string (if it's defined) or
+        '' (if it's not).
+        """
+        return re.sub(r'\$\$|\${\w+}', self._render_sub, template)
+
+    def _render_sub(self, match):
+        s = match.group()
+        if s == '$$': return s
+        else: return getattr(self, s[2:-1])
+
+#######################################################################
+# Example use case: progress bar
+#######################################################################
+
+class SimpleProgressBar:
+    """
+    A simple progress bar which doesn't need any terminal support.
+
+    This prints out a progress bar like:
+      'Header: 0 .. 10.. 20.. ...'
+    """
+
+    def __init__(self, header):
+        self.header = header
+        self.atIndex = None
+
+    def update(self, percent, message):
+        if self.atIndex is None:
+            sys.stdout.write(self.header)
+            self.atIndex = 0
+
+        next = int(percent*50)
+        if next == self.atIndex:
+            return
+
+        for i in range(self.atIndex, next):
+            idx = i % 5
+            if idx == 0:
+                sys.stdout.write('%-2d' % (i*2))
+            elif idx == 1:
+                pass # Skip second char
+            elif idx < 4:
+                sys.stdout.write('.')
+            else:
+                sys.stdout.write(' ')
+        sys.stdout.flush()
+        self.atIndex = next
+
+    def clear(self):
+        if self.atIndex is not None:
+            sys.stdout.write('\n')
+            sys.stdout.flush()
+            self.atIndex = None
+
+class ProgressBar:
+    """
+    A 3-line progress bar, which looks like::
+    
+                                Header
+        20% [===========----------------------------------]
+                           progress message
+
+    The progress bar is colored, if the terminal supports color
+    output; and adjusts to the width of the terminal.
+    """
+    BAR = '%s${GREEN}[${BOLD}%s%s${NORMAL}${GREEN}]${NORMAL}%s\n'
+    HEADER = '${BOLD}${CYAN}%s${NORMAL}\n\n'
+        
+    def __init__(self, term, header, useETA=True):
+        self.term = term
+        if not (self.term.CLEAR_EOL and self.term.UP and self.term.BOL):
+            raise ValueError("Terminal isn't capable enough -- you "
+                             "should use a simpler progress dispaly.")
+        self.width = self.term.COLS or 75
+        self.bar = term.render(self.BAR)
+        self.header = self.term.render(self.HEADER % header.center(self.width))
+        self.cleared = 1 #: true if we haven't drawn the bar yet.
+        self.useETA = useETA
+        if self.useETA:
+            self.startTime = time.time()
+        self.update(0, '')
+
+    def update(self, percent, message):
+        if self.cleared:
+            sys.stdout.write(self.header)
+            self.cleared = 0
+        prefix = '%3d%% ' % (percent*100,)
+        suffix = ''
+        if self.useETA:
+            elapsed = time.time() - self.startTime
+            if percent > .0001 and elapsed > 1:
+                total = elapsed / percent
+                eta = int(total - elapsed)
+                h = eta//3600.
+                m = (eta//60) % 60
+                s = eta % 60
+                suffix = ' ETA: %02d:%02d:%02d'%(h,m,s)
+        barWidth = self.width - len(prefix) - len(suffix) - 2
+        n = int(barWidth*percent)
+        if len(message) < self.width:
+            message = message + ' '*(self.width - len(message))
+        else:
+            message = '... ' + message[-(self.width-4):]
+        sys.stdout.write(
+            self.term.BOL + self.term.UP + self.term.CLEAR_EOL +
+            (self.bar % (prefix, '='*n, '-'*(barWidth-n), suffix)) +
+            self.term.CLEAR_EOL + message)
+
+    def clear(self):
+        if not self.cleared:
+            sys.stdout.write(self.term.BOL + self.term.CLEAR_EOL +
+                             self.term.UP + self.term.CLEAR_EOL +
+                             self.term.UP + self.term.CLEAR_EOL)
+            self.cleared = 1
+
+def test():
+    import time
+    tc = TerminalController()
+    p = ProgressBar(tc, 'Tests')
+    for i in range(101):
+        p.update(i/100., str(i))        
+        time.sleep(.3)
+
+if __name__=='__main__':
+    test()
diff --git a/utils/lit/ShCommands.py b/utils/lit/ShCommands.py
new file mode 100644
index 0000000..be3e680
--- /dev/null
+++ b/utils/lit/ShCommands.py
@@ -0,0 +1,86 @@
+import ShUtil
+
+class Command:
+    def __init__(self, args, redirects):
+        self.args = list(args)
+        self.redirects = list(redirects)
+
+    def __repr__(self):
+        return 'Command(%r, %r)' % (self.args, self.redirects)
+
+    def __cmp__(self, other):
+        if not isinstance(other, Command):
+            return -1
+
+        return cmp((self.args, self.redirects),
+                   (other.args, other.redirects))
+
+    def toShell(self, file):
+        for arg in self.args:
+            if "'" not in arg:
+                quoted = "'%s'" % arg
+            elif '"' not in arg and '$' not in arg:
+                quoted = '"%s"' % arg
+            else:
+                raise NotImplementedError,'Unable to quote %r' % arg
+            print >>file, quoted,
+
+            # For debugging / validation.
+            dequoted = list(ShUtil.ShLexer(quoted).lex())
+            if dequoted != [arg]:
+                raise NotImplementedError,'Unable to quote %r' % arg
+
+        for r in self.redirects:
+            if len(r[0]) == 1:
+                print >>file, "%s '%s'" % (r[0][0], r[1]),
+            else:
+                print >>file, "%s%s '%s'" % (r[0][1], r[0][0], r[1]),
+
+class Pipeline:
+    def __init__(self, commands, negate=False, pipe_err=False):
+        self.commands = commands
+        self.negate = negate
+        self.pipe_err = pipe_err
+
+    def __repr__(self):
+        return 'Pipeline(%r, %r, %r)' % (self.commands, self.negate,
+                                         self.pipe_err)
+
+    def __cmp__(self, other):
+        if not isinstance(other, Pipeline):
+            return -1
+
+        return cmp((self.commands, self.negate, self.pipe_err),
+                   (other.commands, other.negate, self.pipe_err))
+
+    def toShell(self, file, pipefail=False):
+        if pipefail != self.pipe_err:
+            raise ValueError,'Inconsistent "pipefail" attribute!'
+        if self.negate:
+            print >>file, '!',
+        for cmd in self.commands:
+            cmd.toShell(file)
+            if cmd is not self.commands[-1]:
+                print >>file, '|\n ',
+
+class Seq:
+    def __init__(self, lhs, op, rhs):
+        assert op in (';', '&', '||', '&&')
+        self.op = op
+        self.lhs = lhs
+        self.rhs = rhs
+
+    def __repr__(self):
+        return 'Seq(%r, %r, %r)' % (self.lhs, self.op, self.rhs)
+
+    def __cmp__(self, other):
+        if not isinstance(other, Seq):
+            return -1
+
+        return cmp((self.lhs, self.op, self.rhs),
+                   (other.lhs, other.op, other.rhs))
+
+    def toShell(self, file, pipefail=False):
+        self.lhs.toShell(file, pipefail)
+        print >>file, ' %s\n' % self.op
+        self.rhs.toShell(file, pipefail)
diff --git a/utils/lit/ShTest.py b/utils/lit/ShTest.py
new file mode 100644
index 0000000..fefdf76
--- /dev/null
+++ b/utils/lit/ShTest.py
@@ -0,0 +1,12 @@
+import TestRunner
+
+class ShTest:
+    def __init__(self, execute_external = False, require_and_and = False):
+        self.execute_external = execute_external
+        self.require_and_and = require_and_and
+
+    def execute(self, test, litConfig):
+        return TestRunner.executeShTest(test, litConfig,
+                                        self.execute_external,
+                                        self.require_and_and)
+
diff --git a/utils/lit/ShUtil.py b/utils/lit/ShUtil.py
new file mode 100644
index 0000000..c4bbb3d
--- /dev/null
+++ b/utils/lit/ShUtil.py
@@ -0,0 +1,346 @@
+import itertools
+
+import Util
+from ShCommands import Command, Pipeline, Seq
+
+class ShLexer:
+    def __init__(self, data, win32Escapes = False):
+        self.data = data
+        self.pos = 0
+        self.end = len(data)
+        self.win32Escapes = win32Escapes
+
+    def eat(self):
+        c = self.data[self.pos]
+        self.pos += 1
+        return c
+
+    def look(self):
+        return self.data[self.pos]
+
+    def maybe_eat(self, c):
+        """
+        maybe_eat(c) - Consume the character c if it is the next character,
+        returning True if a character was consumed. """
+        if self.data[self.pos] == c:
+            self.pos += 1
+            return True
+        return False
+
+    def lex_arg_fast(self, c):
+        # Get the leading whitespace free section.
+        chunk = self.data[self.pos - 1:].split(None, 1)[0]
+        
+        # If it has special characters, the fast path failed.
+        if ('|' in chunk or '&' in chunk or 
+            '<' in chunk or '>' in chunk or
+            "'" in chunk or '"' in chunk or
+            '\\' in chunk):
+            return None
+        
+        self.pos = self.pos - 1 + len(chunk)
+        return chunk
+        
+    def lex_arg_slow(self, c):
+        if c in "'\"":
+            str = self.lex_arg_quoted(c)
+        else:
+            str = c
+        while self.pos != self.end:
+            c = self.look()
+            if c.isspace() or c in "|&":
+                break
+            elif c in '><':
+                # This is an annoying case; we treat '2>' as a single token so
+                # we don't have to track whitespace tokens.
+
+                # If the parse string isn't an integer, do the usual thing.
+                if not str.isdigit():
+                    break
+
+                # Otherwise, lex the operator and convert to a redirection
+                # token.
+                num = int(str)
+                tok = self.lex_one_token()
+                assert isinstance(tok, tuple) and len(tok) == 1
+                return (tok[0], num)                    
+            elif c == '"':
+                self.eat()
+                str += self.lex_arg_quoted('"')
+            elif not self.win32Escapes and c == '\\':
+                # Outside of a string, '\\' escapes everything.
+                self.eat()
+                if self.pos == self.end:
+                    Util.warning("escape at end of quoted argument in: %r" % 
+                                 self.data)
+                    return str
+                str += self.eat()
+            else:
+                str += self.eat()
+        return str
+
+    def lex_arg_quoted(self, delim):
+        str = ''
+        while self.pos != self.end:
+            c = self.eat()
+            if c == delim:
+                return str
+            elif c == '\\' and delim == '"':
+                # Inside a '"' quoted string, '\\' only escapes the quote
+                # character and backslash, otherwise it is preserved.
+                if self.pos == self.end:
+                    Util.warning("escape at end of quoted argument in: %r" % 
+                                 self.data)
+                    return str
+                c = self.eat()
+                if c == '"': # 
+                    str += '"'
+                elif c == '\\':
+                    str += '\\'
+                else:
+                    str += '\\' + c
+            else:
+                str += c
+        Util.warning("missing quote character in %r" % self.data)
+        return str
+    
+    def lex_arg_checked(self, c):
+        pos = self.pos
+        res = self.lex_arg_fast(c)
+        end = self.pos
+
+        self.pos = pos
+        reference = self.lex_arg_slow(c)
+        if res is not None:
+            if res != reference:
+                raise ValueError,"Fast path failure: %r != %r" % (res, reference)
+            if self.pos != end:
+                raise ValueError,"Fast path failure: %r != %r" % (self.pos, end)
+        return reference
+        
+    def lex_arg(self, c):
+        return self.lex_arg_fast(c) or self.lex_arg_slow(c)
+        
+    def lex_one_token(self):
+        """
+        lex_one_token - Lex a single 'sh' token. """
+
+        c = self.eat()
+        if c in ';!':
+            return (c,)
+        if c == '|':
+            if self.maybe_eat('|'):
+                return ('||',)
+            return (c,)
+        if c == '&':
+            if self.maybe_eat('&'):
+                return ('&&',)
+            if self.maybe_eat('>'): 
+                return ('&>',)
+            return (c,)
+        if c == '>':
+            if self.maybe_eat('&'):
+                return ('>&',)
+            if self.maybe_eat('>'):
+                return ('>>',)
+            return (c,)
+        if c == '<':
+            if self.maybe_eat('&'):
+                return ('<&',)
+            if self.maybe_eat('>'):
+                return ('<<',)
+            return (c,)
+
+        return self.lex_arg(c)
+
+    def lex(self):
+        while self.pos != self.end:
+            if self.look().isspace():
+                self.eat()
+            else:
+                yield self.lex_one_token()
+
+###
+ 
+class ShParser:
+    def __init__(self, data, win32Escapes = False):
+        self.data = data
+        self.tokens = ShLexer(data, win32Escapes = win32Escapes).lex()
+    
+    def lex(self):
+        try:
+            return self.tokens.next()
+        except StopIteration:
+            return None
+    
+    def look(self):
+        next = self.lex()
+        if next is not None:
+            self.tokens = itertools.chain([next], self.tokens)
+        return next
+    
+    def parse_command(self):
+        tok = self.lex()
+        if not tok:
+            raise ValueError,"empty command!"
+        if isinstance(tok, tuple):
+            raise ValueError,"syntax error near unexpected token %r" % tok[0]
+        
+        args = [tok]
+        redirects = []
+        while 1:
+            tok = self.look()
+
+            # EOF?
+            if tok is None:
+                break
+
+            # If this is an argument, just add it to the current command.
+            if isinstance(tok, str):
+                args.append(self.lex())
+                continue
+
+            # Otherwise see if it is a terminator.
+            assert isinstance(tok, tuple)
+            if tok[0] in ('|',';','&','||','&&'):
+                break
+            
+            # Otherwise it must be a redirection.
+            op = self.lex()
+            arg = self.lex()
+            if not arg:
+                raise ValueError,"syntax error near token %r" % op[0]
+            redirects.append((op, arg))
+
+        return Command(args, redirects)
+
+    def parse_pipeline(self):
+        negate = False
+        if self.look() == ('!',):
+            self.lex()
+            negate = True
+
+        commands = [self.parse_command()]
+        while self.look() == ('|',):
+            self.lex()
+            commands.append(self.parse_command())
+        return Pipeline(commands, negate)
+            
+    def parse(self):
+        lhs = self.parse_pipeline()
+
+        while self.look():
+            operator = self.lex()
+            assert isinstance(operator, tuple) and len(operator) == 1
+
+            if not self.look():
+                raise ValueError, "missing argument to operator %r" % operator[0]
+            
+            # FIXME: Operator precedence!!
+            lhs = Seq(lhs, operator[0], self.parse_pipeline())
+
+        return lhs
+
+###
+
+import unittest
+
+class TestShLexer(unittest.TestCase):
+    def lex(self, str, *args, **kwargs):
+        return list(ShLexer(str, *args, **kwargs).lex())
+
+    def test_basic(self):
+        self.assertEqual(self.lex('a|b>c&d<e'),
+                         ['a', ('|',), 'b', ('>',), 'c', ('&',), 'd', 
+                          ('<',), 'e'])
+
+    def test_redirection_tokens(self):
+        self.assertEqual(self.lex('a2>c'),
+                         ['a2', ('>',), 'c'])
+        self.assertEqual(self.lex('a 2>c'),
+                         ['a', ('>',2), 'c'])
+        
+    def test_quoting(self):
+        self.assertEqual(self.lex(""" 'a' """),
+                         ['a'])
+        self.assertEqual(self.lex(""" "hello\\"world" """),
+                         ['hello"world'])
+        self.assertEqual(self.lex(""" "hello\\'world" """),
+                         ["hello\\'world"])
+        self.assertEqual(self.lex(""" "hello\\\\world" """),
+                         ["hello\\world"])
+        self.assertEqual(self.lex(""" he"llo wo"rld """),
+                         ["hello world"])
+        self.assertEqual(self.lex(""" a\\ b a\\\\b """),
+                         ["a b", "a\\b"])
+        self.assertEqual(self.lex(""" "" "" """),
+                         ["", ""])
+        self.assertEqual(self.lex(""" a\\ b """, win32Escapes = True),
+                         ['a\\', 'b'])
+
+class TestShParse(unittest.TestCase):
+    def parse(self, str):
+        return ShParser(str).parse()
+
+    def test_basic(self):
+        self.assertEqual(self.parse('echo hello'),
+                         Pipeline([Command(['echo', 'hello'], [])], False))
+        self.assertEqual(self.parse('echo ""'),
+                         Pipeline([Command(['echo', ''], [])], False))
+
+    def test_redirection(self):
+        self.assertEqual(self.parse('echo hello > c'),
+                         Pipeline([Command(['echo', 'hello'], 
+                                           [((('>'),), 'c')])], False))
+        self.assertEqual(self.parse('echo hello > c >> d'),
+                         Pipeline([Command(['echo', 'hello'], [(('>',), 'c'),
+                                                     (('>>',), 'd')])], False))
+        self.assertEqual(self.parse('a 2>&1'),
+                         Pipeline([Command(['a'], [(('>&',2), '1')])], False))
+
+    def test_pipeline(self):
+        self.assertEqual(self.parse('a | b'),
+                         Pipeline([Command(['a'], []),
+                                   Command(['b'], [])],
+                                  False))
+
+        self.assertEqual(self.parse('a | b | c'),
+                         Pipeline([Command(['a'], []),
+                                   Command(['b'], []),
+                                   Command(['c'], [])],
+                                  False))
+
+        self.assertEqual(self.parse('! a'),
+                         Pipeline([Command(['a'], [])],
+                                  True))
+
+    def test_list(self):        
+        self.assertEqual(self.parse('a ; b'),
+                         Seq(Pipeline([Command(['a'], [])], False),
+                             ';',
+                             Pipeline([Command(['b'], [])], False)))
+
+        self.assertEqual(self.parse('a & b'),
+                         Seq(Pipeline([Command(['a'], [])], False),
+                             '&',
+                             Pipeline([Command(['b'], [])], False)))
+
+        self.assertEqual(self.parse('a && b'),
+                         Seq(Pipeline([Command(['a'], [])], False),
+                             '&&',
+                             Pipeline([Command(['b'], [])], False)))
+
+        self.assertEqual(self.parse('a || b'),
+                         Seq(Pipeline([Command(['a'], [])], False),
+                             '||',
+                             Pipeline([Command(['b'], [])], False)))
+
+        self.assertEqual(self.parse('a && b || c'),
+                         Seq(Seq(Pipeline([Command(['a'], [])], False),
+                                 '&&',
+                                 Pipeline([Command(['b'], [])], False)),
+                             '||',
+                             Pipeline([Command(['c'], [])], False)))
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/utils/lit/TODO b/utils/lit/TODO
new file mode 100644
index 0000000..4d00d2c
--- /dev/null
+++ b/utils/lit/TODO
@@ -0,0 +1,19 @@
+ - Move temp directory name into local test config.
+
+ - Add --show-unsupported, don't show by default?
+
+ - Finish documentation.
+
+ - Optionally use multiprocessing.
+
+ - Support llvmc and ocaml tests.
+
+ - Support valgrind in all configs, and LLVM style valgrind.
+
+ - Provide test suite config for running unit tests.
+
+ - Support a timeout / ulimit.
+
+ - Support "disabling" tests? The advantage of making this distinct from XFAIL
+   is it makes it more obvious that it is a temporary measure (and lit can put
+   in a separate category).
diff --git a/utils/lit/TclTest.py b/utils/lit/TclTest.py
new file mode 100644
index 0000000..e79f179
--- /dev/null
+++ b/utils/lit/TclTest.py
@@ -0,0 +1,7 @@
+import TestRunner
+
+class TclTest:
+    def execute(self, test, litConfig):
+        return TestRunner.executeTclTest(test, litConfig)
+
+
diff --git a/utils/lit/TclUtil.py b/utils/lit/TclUtil.py
new file mode 100644
index 0000000..da7659d
--- /dev/null
+++ b/utils/lit/TclUtil.py
@@ -0,0 +1,322 @@
+import itertools
+
+from ShCommands import Command, Pipeline
+
+def tcl_preprocess(data):
+    # Tcl has a preprocessing step to replace escaped newlines.
+    i = data.find('\\\n')
+    if i == -1:
+        return data
+
+    # Replace '\\\n' and subsequent whitespace by a single space.
+    n = len(data)
+    str = data[:i]
+    i += 2
+    while i < n and data[i] in ' \t':
+        i += 1
+    return str + ' ' + data[i:]
+
+class TclLexer:
+    """TclLexer - Lex a string into "words", following the Tcl syntax."""
+
+    def __init__(self, data):
+        self.data = tcl_preprocess(data)
+        self.pos = 0
+        self.end = len(self.data)
+
+    def at_end(self):
+        return self.pos == self.end
+
+    def eat(self):
+        c = self.data[self.pos]
+        self.pos += 1
+        return c
+
+    def look(self):
+        return self.data[self.pos]
+
+    def maybe_eat(self, c):
+        """
+        maybe_eat(c) - Consume the character c if it is the next character,
+        returning True if a character was consumed. """
+        if self.data[self.pos] == c:
+            self.pos += 1
+            return True
+        return False
+
+    def escape(self, c):
+        if c == 'a':
+            return '\x07'
+        elif c == 'b':
+            return '\x08'
+        elif c == 'f':
+            return '\x0c'
+        elif c == 'n':
+            return '\n'
+        elif c == 'r':
+            return '\r'
+        elif c == 't':
+            return '\t'
+        elif c == 'v':
+            return '\x0b'
+        elif c in 'uxo':
+            raise ValueError,'Invalid quoted character %r' % c
+        else:
+            return c
+        
+    def lex_braced(self):
+        # Lex until whitespace or end of string, the opening brace has already
+        # been consumed.
+
+        str = ''        
+        while 1:
+            if self.at_end():
+                raise ValueError,"Unterminated '{' quoted word"
+            
+            c = self.eat()
+            if c == '}':
+                break
+            elif c == '{':
+                str += '{' + self.lex_braced() + '}'
+            elif c == '\\' and self.look() in '{}':
+                str += self.eat()
+            else:
+                str += c
+
+        return str
+
+    def lex_quoted(self):
+        str = ''
+
+        while 1:
+            if self.at_end():
+                raise ValueError,"Unterminated '\"' quoted word"
+            
+            c = self.eat()
+            if c == '"':
+                break
+            elif c == '\\':
+                if self.at_end():
+                    raise ValueError,'Missing quoted character'
+
+                str += self.escape(self.eat())
+            else:
+                str += c
+
+        return str
+
+    def lex_unquoted(self, process_all=False):
+        # Lex until whitespace or end of string.
+        str = ''
+        while not self.at_end():
+            if not process_all:
+                if self.look().isspace() or self.look() == ';':
+                    break
+
+            c = self.eat()
+            if c == '\\':
+                if self.at_end():
+                    raise ValueError,'Missing quoted character'
+
+                str += self.escape(self.eat())
+            elif c == '[':
+                raise NotImplementedError, ('Command substitution is '
+                                            'not supported')
+            elif c == '$' and not self.at_end() and (self.look().isalpha() or
+                                                     self.look() == '{'):
+                raise NotImplementedError, ('Variable substitution is '
+                                            'not supported')
+            else:
+                str += c
+
+        return str
+
+    def lex_one_token(self):
+        if self.maybe_eat('"'):
+            return self.lex_quoted()
+        elif self.maybe_eat('{'):
+            # Check for argument substitution.
+            if not self.maybe_eat('*'):
+                return self.lex_braced()
+
+            if not self.maybe_eat('}'):
+                    return '*' + self.lex_braced()
+                
+            if self.at_end() or self.look().isspace():
+                return '*'
+
+            raise NotImplementedError, "Argument substitution is unsupported"
+        else:
+            return self.lex_unquoted()
+
+    def lex(self):
+        while not self.at_end():
+            c = self.look()
+            if c in ' \t':
+                self.eat()
+            elif c in ';\n':
+                self.eat()
+                yield (';',)
+            else:
+                yield self.lex_one_token()
+
+class TclExecCommand:
+    kRedirectPrefixes1 = ('<', '>')
+    kRedirectPrefixes2 = ('<@', '<<', '2>', '>&', '>>', '>@')
+    kRedirectPrefixes3 = ('2>@', '2>>', '>>&', '>&@')
+    kRedirectPrefixes4 = ('2>@1',)
+
+    def __init__(self, args):
+        self.args = iter(args)
+
+    def lex(self):
+        try:
+            return self.args.next()
+        except StopIteration:
+            return None
+
+    def look(self):
+        next = self.lex()
+        if next is not None:
+            self.args = itertools.chain([next], self.args)
+        return next
+
+    def parse_redirect(self, tok, length):
+        if len(tok) == length:
+            arg = self.lex()
+            if next is None:
+                raise ValueError,'Missing argument to %r redirection' % tok
+        else:
+            tok,arg = tok[:length],tok[length:]
+
+        if tok[0] == '2':
+            op = (tok[1:],2)
+        else:
+            op = (tok,)
+        return (op, arg)
+
+    def parse_pipeline(self):
+        if self.look() is None:
+            raise ValueError,"Expected at least one argument to exec"
+
+        commands = [Command([],[])]
+        while 1:
+            arg = self.lex()
+            if arg is None:
+                break
+            elif arg == '|':
+                commands.append(Command([],[]))
+            elif arg == '|&':
+                # Write this as a redirect of stderr; it must come first because
+                # stdout may have already been redirected.
+                commands[-1].redirects.insert(0, (('>&',2),'1'))
+                commands.append(Command([],[]))
+            elif arg[:4] in TclExecCommand.kRedirectPrefixes4:
+                commands[-1].redirects.append(self.parse_redirect(arg, 4))
+            elif arg[:3] in TclExecCommand.kRedirectPrefixes3:
+                commands[-1].redirects.append(self.parse_redirect(arg, 3))
+            elif arg[:2] in TclExecCommand.kRedirectPrefixes2:
+                commands[-1].redirects.append(self.parse_redirect(arg, 2))
+            elif arg[:1] in TclExecCommand.kRedirectPrefixes1:
+                commands[-1].redirects.append(self.parse_redirect(arg, 1))
+            else:
+                commands[-1].args.append(arg)
+
+        return Pipeline(commands, False, pipe_err=True)
+
+    def parse(self):
+        ignoreStderr = False
+        keepNewline = False
+
+        # Parse arguments.
+        while 1:
+            next = self.look()
+            if not isinstance(next, str) or next[0] != '-':
+                break
+
+            if next == '--':
+                self.lex()
+                break
+            elif next == '-ignorestderr':
+                ignoreStderr = True
+            elif next == '-keepnewline':
+                keepNewline = True
+            else:
+                raise ValueError,"Invalid exec argument %r" % next
+
+        return (ignoreStderr, keepNewline, self.parse_pipeline())
+
+###
+
+import unittest
+
+class TestTclLexer(unittest.TestCase):
+    def lex(self, str, *args, **kwargs):
+        return list(TclLexer(str, *args, **kwargs).lex())
+
+    def test_preprocess(self):
+        self.assertEqual(tcl_preprocess('a b'), 'a b')
+        self.assertEqual(tcl_preprocess('a\\\nb c'), 'a b c')
+
+    def test_unquoted(self):
+        self.assertEqual(self.lex('a b c'),
+                         ['a', 'b', 'c'])
+        self.assertEqual(self.lex(r'a\nb\tc\ '),
+                         ['a\nb\tc '])
+        self.assertEqual(self.lex(r'a \\\$b c $\\'),
+                         ['a', r'\$b', 'c', '$\\'])
+
+    def test_braced(self):
+        self.assertEqual(self.lex('a {b c} {}'),
+                         ['a', 'b c', ''])
+        self.assertEqual(self.lex(r'a {b {c\n}}'),
+                         ['a', 'b {c\\n}'])
+        self.assertEqual(self.lex(r'a {b\{}'),
+                         ['a', 'b{'])
+        self.assertEqual(self.lex(r'{*}'), ['*'])
+        self.assertEqual(self.lex(r'{*} a'), ['*', 'a'])
+        self.assertEqual(self.lex(r'{*} a'), ['*', 'a'])
+        self.assertEqual(self.lex('{a\\\n   b}'),
+                         ['a b'])
+
+    def test_quoted(self):
+        self.assertEqual(self.lex('a "b c"'),
+                         ['a', 'b c'])
+
+    def test_terminators(self):
+        self.assertEqual(self.lex('a\nb'),
+                         ['a', (';',), 'b'])
+        self.assertEqual(self.lex('a;b'),
+                         ['a', (';',), 'b'])
+        self.assertEqual(self.lex('a   ;   b'),
+                         ['a', (';',), 'b'])
+
+class TestTclExecCommand(unittest.TestCase):
+    def parse(self, str):
+        return TclExecCommand(list(TclLexer(str).lex())).parse()
+
+    def test_basic(self):
+        self.assertEqual(self.parse('echo hello'),
+                         (False, False,
+                          Pipeline([Command(['echo', 'hello'], [])],
+                                   False, True)))
+        self.assertEqual(self.parse('echo hello | grep hello'),
+                         (False, False,
+                          Pipeline([Command(['echo', 'hello'], []),
+                                    Command(['grep', 'hello'], [])],
+                                   False, True)))
+
+    def test_redirect(self):
+        self.assertEqual(self.parse('echo hello > a >b >>c 2> d |& e'),
+                         (False, False,
+                          Pipeline([Command(['echo', 'hello'],
+                                            [(('>',),'a'),
+                                             (('>',),'b'),
+                                             (('>>',),'c'),
+                                             (('>',2),'d'),
+                                             (('>&',2),'1')]),
+                                    Command(['e'], [])],
+                                   False, True)))
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/utils/lit/Test.py b/utils/lit/Test.py
new file mode 100644
index 0000000..d3f6274
--- /dev/null
+++ b/utils/lit/Test.py
@@ -0,0 +1,71 @@
+import os
+
+# Test results.
+
+class TestResult:
+    def __init__(self, name, isFailure):
+        self.name = name
+        self.isFailure = isFailure
+
+PASS        = TestResult('PASS', False)
+XFAIL       = TestResult('XFAIL', False)
+FAIL        = TestResult('FAIL', True)
+XPASS       = TestResult('XPASS', True)
+UNRESOLVED  = TestResult('UNRESOLVED', True)
+UNSUPPORTED = TestResult('UNSUPPORTED', False)
+
+# Test classes.
+
+class TestFormat:
+    """TestFormat - Test information provider."""
+
+    def __init__(self, name):
+        self.name = name
+
+class TestSuite:
+    """TestSuite - Information on a group of tests.
+
+    A test suite groups together a set of logically related tests.
+    """
+
+    def __init__(self, name, source_root, exec_root, config):
+        self.name = name
+        self.source_root = source_root
+        self.exec_root = exec_root
+        # The test suite configuration.
+        self.config = config
+
+    def getSourcePath(self, components):
+        return os.path.join(self.source_root, *components)
+
+    def getExecPath(self, components):
+        return os.path.join(self.exec_root, *components)
+
+class Test:
+    """Test - Information on a single test instance."""
+
+    def __init__(self, suite, path_in_suite, config):
+        self.suite = suite
+        self.path_in_suite = path_in_suite
+        self.config = config
+        # The test result code, once complete.
+        self.result = None
+        # Any additional output from the test, once complete.
+        self.output = None
+        # The wall time to execute this test, if timing and once complete.
+        self.elapsed = None
+
+    def setResult(self, result, output, elapsed):
+        assert self.result is None, "Test result already set!"
+        self.result = result
+        self.output = output
+        self.elapsed = elapsed
+
+    def getFullName(self):
+        return self.suite.config.name + '::' + '/'.join(self.path_in_suite)
+
+    def getSourcePath(self):
+        return self.suite.getSourcePath(self.path_in_suite)
+
+    def getExecPath(self):
+        return self.suite.getExecPath(self.path_in_suite)
diff --git a/utils/lit/TestRunner.py b/utils/lit/TestRunner.py
new file mode 100644
index 0000000..954013a
--- /dev/null
+++ b/utils/lit/TestRunner.py
@@ -0,0 +1,460 @@
+import os, signal, subprocess, sys
+import StringIO
+
+import ShUtil
+import Test
+import Util
+
+def executeCommand(command, cwd=None, env=None):
+    p = subprocess.Popen(command, cwd=cwd,
+                         stdin=subprocess.PIPE,
+                         stdout=subprocess.PIPE,
+                         stderr=subprocess.PIPE,
+                         env=env)
+    out,err = p.communicate()
+    exitCode = p.wait()
+
+    # Detect Ctrl-C in subprocess.
+    if exitCode == -signal.SIGINT:
+        raise KeyboardInterrupt
+
+    return out, err, exitCode
+
+def executeShCmd(cmd, cfg, cwd, results):
+    if isinstance(cmd, ShUtil.Seq):
+        if cmd.op == ';':
+            res = executeShCmd(cmd.lhs, cfg, cwd, results)
+            return executeShCmd(cmd.rhs, cfg, cwd, results)
+
+        if cmd.op == '&':
+            raise NotImplementedError,"unsupported test command: '&'"
+
+        if cmd.op == '||':
+            res = executeShCmd(cmd.lhs, cfg, cwd, results)
+            if res != 0:
+                res = executeShCmd(cmd.rhs, cfg, cwd, results)
+            return res
+        if cmd.op == '&&':
+            res = executeShCmd(cmd.lhs, cfg, cwd, results)
+            if res is None:
+                return res
+
+            if res == 0:
+                res = executeShCmd(cmd.rhs, cfg, cwd, results)
+            return res
+
+        raise ValueError,'Unknown shell command: %r' % cmd.op
+
+    assert isinstance(cmd, ShUtil.Pipeline)
+    procs = []
+    input = subprocess.PIPE
+    for j in cmd.commands:
+        redirects = [(0,), (1,), (2,)]
+        for r in j.redirects:
+            if r[0] == ('>',2):
+                redirects[2] = [r[1], 'w', None]
+            elif r[0] == ('>&',2) and r[1] in '012':
+                redirects[2] = redirects[int(r[1])]
+            elif r[0] == ('>&',) or r[0] == ('&>',):
+                redirects[1] = redirects[2] = [r[1], 'w', None]
+            elif r[0] == ('>',):
+                redirects[1] = [r[1], 'w', None]
+            elif r[0] == ('<',):
+                redirects[0] = [r[1], 'r', None]
+            else:
+                raise NotImplementedError,"Unsupported redirect: %r" % (r,)
+
+        final_redirects = []
+        for index,r in enumerate(redirects):
+            if r == (0,):
+                result = input
+            elif r == (1,):
+                if index == 0:
+                    raise NotImplementedError,"Unsupported redirect for stdin"
+                elif index == 1:
+                    result = subprocess.PIPE
+                else:
+                    result = subprocess.STDOUT
+            elif r == (2,):
+                if index != 2:
+                    raise NotImplementedError,"Unsupported redirect on stdout"
+                result = subprocess.PIPE
+            else:
+                if r[2] is None:
+                    r[2] = open(r[0], r[1])
+                result = r[2]
+            final_redirects.append(result)
+
+        stdin, stdout, stderr = final_redirects
+
+        # If stderr wants to come from stdout, but stdout isn't a pipe, then put
+        # stderr on a pipe and treat it as stdout.
+        if (stderr == subprocess.STDOUT and stdout != subprocess.PIPE):
+            stderr = subprocess.PIPE
+            stderrIsStdout = True
+        else:
+            stderrIsStdout = False
+        procs.append(subprocess.Popen(j.args, cwd=cwd,
+                                      stdin = stdin,
+                                      stdout = stdout,
+                                      stderr = stderr,
+                                      env = cfg.environment,
+                                      close_fds = True))
+
+        # Immediately close stdin for any process taking stdin from us.
+        if stdin == subprocess.PIPE:
+            procs[-1].stdin.close()
+            procs[-1].stdin = None
+
+        # Update the current stdin source.
+        if stdout == subprocess.PIPE:
+            input = procs[-1].stdout
+        elif stderrIsStdout:
+            input = procs[-1].stderr
+        else:
+            input = subprocess.PIPE
+
+    # FIXME: There is a potential for deadlock here, when we have a pipe and
+    # some process other than the last one ends up blocked on stderr.
+    procData = [None] * len(procs)
+    procData[-1] = procs[-1].communicate()
+    for i in range(len(procs) - 1):
+        if procs[i].stdout is not None:
+            out = procs[i].stdout.read()
+        else:
+            out = ''
+        if procs[i].stderr is not None:
+            err = procs[i].stderr.read()
+        else:
+            err = ''
+        procData[i] = (out,err)
+
+    exitCode = None
+    for i,(out,err) in enumerate(procData):
+        res = procs[i].wait()
+        # Detect Ctrl-C in subprocess.
+        if res == -signal.SIGINT:
+            raise KeyboardInterrupt
+
+        results.append((cmd.commands[i], out, err, res))
+        if cmd.pipe_err:
+            # Python treats the exit code as a signed char.
+            if res < 0:
+                exitCode = min(exitCode, res)
+            else:
+                exitCode = max(exitCode, res)
+        else:
+            exitCode = res
+
+    if cmd.negate:
+        exitCode = not exitCode
+
+    return exitCode
+
+def executeScriptInternal(test, litConfig, tmpBase, commands, cwd):
+    ln = ' &&\n'.join(commands)
+    try:
+        cmd = ShUtil.ShParser(ln, litConfig.isWindows).parse()
+    except:
+        return (Test.FAIL, "shell parser error on: %r" % ln)
+
+    results = []
+    exitCode = executeShCmd(cmd, test.config, cwd, results)
+
+    out = err = ''
+    for i,(cmd, cmd_out,cmd_err,res) in enumerate(results):
+        out += 'Command %d: %s\n' % (i, ' '.join('"%s"' % s for s in cmd.args))
+        out += 'Command %d Result: %r\n' % (i, res)
+        out += 'Command %d Output:\n%s\n\n' % (i, cmd_out)
+        out += 'Command %d Stderr:\n%s\n\n' % (i, cmd_err)
+
+    return out, err, exitCode
+
+def executeTclScriptInternal(test, litConfig, tmpBase, commands, cwd):
+    import TclUtil
+    cmds = []
+    for ln in commands:
+        # Given the unfortunate way LLVM's test are written, the line gets
+        # backslash substitution done twice.
+        ln = TclUtil.TclLexer(ln).lex_unquoted(process_all = True)
+
+        try:
+            tokens = list(TclUtil.TclLexer(ln).lex())
+        except:
+            return (Test.FAIL, "Tcl lexer error on: %r" % ln)
+
+        # Validate there are no control tokens.
+        for t in tokens:
+            if not isinstance(t, str):
+                return (Test.FAIL,
+                        "Invalid test line: %r containing %r" % (ln, t))
+
+        try:
+            cmds.append(TclUtil.TclExecCommand(tokens).parse_pipeline())
+        except:
+            return (TestStatus.Fail, "Tcl 'exec' parse error on: %r" % ln)
+
+    cmd = cmds[0]
+    for c in cmds[1:]:
+        cmd = ShUtil.Seq(cmd, '&&', c)
+
+    if litConfig.useTclAsSh:
+        script = tmpBase + '.script'
+
+        # Write script file
+        f = open(script,'w')
+        print >>f, 'set -o pipefail'
+        cmd.toShell(f, pipefail = True)
+        f.close()
+
+        if 0:
+            print >>sys.stdout, cmd
+            print >>sys.stdout, open(script).read()
+            print >>sys.stdout
+            return '', '', 0
+
+        command = ['/bin/sh', script]
+        out,err,exitCode = executeCommand(command, cwd=cwd,
+                                          env=test.config.environment)
+
+        # Tcl commands fail on standard error output.
+        if err:
+            exitCode = 1
+            out = 'Command has output on stderr!\n\n' + out
+
+        return out,err,exitCode
+    else:
+        results = []
+        exitCode = executeShCmd(cmd, test.config, cwd, results)
+
+    out = err = ''
+
+    # Tcl commands fail on standard error output.
+    if [True for _,_,err,res in results if err]:
+        exitCode = 1
+        out += 'Command has output on stderr!\n\n'
+
+    for i,(cmd, cmd_out, cmd_err, res) in enumerate(results):
+        out += 'Command %d: %s\n' % (i, ' '.join('"%s"' % s for s in cmd.args))
+        out += 'Command %d Result: %r\n' % (i, res)
+        out += 'Command %d Output:\n%s\n\n' % (i, cmd_out)
+        out += 'Command %d Stderr:\n%s\n\n' % (i, cmd_err)
+
+    return out, err, exitCode
+
+def executeScript(test, litConfig, tmpBase, commands, cwd):
+    script = tmpBase + '.script'
+    if litConfig.isWindows:
+        script += '.bat'
+
+    # Write script file
+    f = open(script,'w')
+    if litConfig.isWindows:
+        f.write('\nif %ERRORLEVEL% NEQ 0 EXIT\n'.join(commands))
+    else:
+        f.write(' &&\n'.join(commands))
+    f.write('\n')
+    f.close()
+
+    if litConfig.isWindows:
+        command = ['cmd','/c', script]
+    else:
+        command = ['/bin/sh', script]
+        if litConfig.useValgrind:
+            # FIXME: Running valgrind on sh is overkill. We probably could just
+            # run on clang with no real loss.
+            valgrindArgs = ['valgrind', '-q',
+                            '--tool=memcheck', '--trace-children=yes',
+                            '--error-exitcode=123']
+            valgrindArgs.extend(litConfig.valgrindArgs)
+
+            command = valgrindArgs + command
+
+    return executeCommand(command, cwd=cwd, env=test.config.environment)
+
+def parseIntegratedTestScript(test, xfailHasColon, requireAndAnd):
+    """parseIntegratedTestScript - Scan an LLVM/Clang style integrated test
+    script and extract the lines to 'RUN' as well as 'XFAIL' and 'XTARGET'
+    information. The RUN lines also will have variable substitution performed.
+    """
+
+    # Get the temporary location, this is always relative to the test suite
+    # root, not test source root.
+    #
+    # FIXME: This should not be here?
+    sourcepath = test.getSourcePath()
+    execpath = test.getExecPath()
+    execdir,execbase = os.path.split(execpath)
+    tmpBase = os.path.join(execdir, 'Output', execbase)
+
+    # We use #_MARKER_# to hide %% while we do the other substitutions.
+    substitutions = [('%%', '#_MARKER_#')]
+    substitutions.extend(test.config.substitutions)
+    substitutions.extend([('%s', sourcepath),
+                          ('%S', os.path.dirname(sourcepath)),
+                          ('%p', os.path.dirname(sourcepath)),
+                          ('%t', tmpBase + '.tmp'),
+                          ('#_MARKER_#', '%')])
+
+    # Collect the test lines from the script.
+    script = []
+    xfails = []
+    xtargets = []
+    for ln in open(sourcepath):
+        if 'RUN:' in ln:
+            # Isolate the command to run.
+            index = ln.index('RUN:')
+            ln = ln[index+4:]
+
+            # Trim trailing whitespace.
+            ln = ln.rstrip()
+
+            # Collapse lines with trailing '\\'.
+            if script and script[-1][-1] == '\\':
+                script[-1] = script[-1][:-1] + ln
+            else:
+                script.append(ln)
+        elif xfailHasColon and 'XFAIL:' in ln:
+            items = ln[ln.index('XFAIL:') + 6:].split(',')
+            xfails.extend([s.strip() for s in items])
+        elif not xfailHasColon and 'XFAIL' in ln:
+            items = ln[ln.index('XFAIL') + 5:].split(',')
+            xfails.extend([s.strip() for s in items])
+        elif 'XTARGET:' in ln:
+            items = ln[ln.index('XTARGET:') + 8:].split(',')
+            xtargets.extend([s.strip() for s in items])
+        elif 'END.' in ln:
+            # Check for END. lines.
+            if ln[ln.index('END.'):].strip() == 'END.':
+                break
+
+    # Apply substitutions to the script.
+    def processLine(ln):
+        # Apply substitutions
+        for a,b in substitutions:
+            ln = ln.replace(a,b)
+
+        # Strip the trailing newline and any extra whitespace.
+        return ln.strip()
+    script = map(processLine, script)
+
+    # Verify the script contains a run line.
+    if not script:
+        return (Test.UNRESOLVED, "Test has no run line!")
+
+    if script[-1][-1] == '\\':
+        return (Test.UNRESOLVED, "Test has unterminated run lines (with '\\')")
+
+    # Validate interior lines for '&&', a lovely historical artifact.
+    if requireAndAnd:
+        for i in range(len(script) - 1):
+            ln = script[i]
+
+            if not ln.endswith('&&'):
+                return (Test.FAIL,
+                        ("MISSING \'&&\': %s\n"  +
+                         "FOLLOWED BY   : %s\n") % (ln, script[i + 1]))
+
+            # Strip off '&&'
+            script[i] = ln[:-2]
+
+    return script,xfails,xtargets,tmpBase,execdir
+
+def formatTestOutput(status, out, err, exitCode, script):
+    output = StringIO.StringIO()
+    print >>output, "Script:"
+    print >>output, "--"
+    print >>output, '\n'.join(script)
+    print >>output, "--"
+    print >>output, "Exit Code: %r" % exitCode
+    print >>output, "Command Output (stdout):"
+    print >>output, "--"
+    output.write(out)
+    print >>output, "--"
+    print >>output, "Command Output (stderr):"
+    print >>output, "--"
+    output.write(err)
+    print >>output, "--"
+    return (status, output.getvalue())
+
+def executeTclTest(test, litConfig):
+    if test.config.unsupported:
+        return (Test.UNSUPPORTED, 'Test is unsupported')
+
+    res = parseIntegratedTestScript(test, True, False)
+    if len(res) == 2:
+        return res
+
+    script, xfails, xtargets, tmpBase, execdir = res
+
+    if litConfig.noExecute:
+        return (Test.PASS, '')
+
+    # Create the output directory if it does not already exist.
+    Util.mkdir_p(os.path.dirname(tmpBase))
+
+    res = executeTclScriptInternal(test, litConfig, tmpBase, script, execdir)
+    if len(res) == 2:
+        return res
+
+    isXFail = False
+    for item in xfails:
+        if item == '*' or item in test.suite.config.target_triple:
+            isXFail = True
+            break
+
+    # If this is XFAIL, see if it is expected to pass on this target.
+    if isXFail:
+        for item in xtargets:
+            if item == '*' or item in test.suite.config.target_triple:
+                isXFail = False
+                break
+
+    out,err,exitCode = res
+    if isXFail:
+        ok = exitCode != 0
+        status = (Test.XPASS, Test.XFAIL)[ok]
+    else:
+        ok = exitCode == 0
+        status = (Test.FAIL, Test.PASS)[ok]
+
+    if ok:
+        return (status,'')
+
+    return formatTestOutput(status, out, err, exitCode, script)
+
+def executeShTest(test, litConfig, useExternalSh, requireAndAnd):
+    if test.config.unsupported:
+        return (Test.UNSUPPORTED, 'Test is unsupported')
+
+    res = parseIntegratedTestScript(test, False, requireAndAnd)
+    if len(res) == 2:
+        return res
+
+    script, xfails, xtargets, tmpBase, execdir = res
+
+    if litConfig.noExecute:
+        return (Test.PASS, '')
+
+    # Create the output directory if it does not already exist.
+    Util.mkdir_p(os.path.dirname(tmpBase))
+
+    if useExternalSh:
+        res = executeScript(test, litConfig, tmpBase, script, execdir)
+    else:
+        res = executeScriptInternal(test, litConfig, tmpBase, script, execdir)
+    if len(res) == 2:
+        return res
+
+    out,err,exitCode = res
+    if xfails:
+        ok = exitCode != 0
+        status = (Test.XPASS, Test.XFAIL)[ok]
+    else:
+        ok = exitCode == 0
+        status = (Test.FAIL, Test.PASS)[ok]
+
+    if ok:
+        return (status,'')
+
+    return formatTestOutput(status, out, err, exitCode, script)
diff --git a/utils/lit/TestingConfig.py b/utils/lit/TestingConfig.py
new file mode 100644
index 0000000..bfe23b2
--- /dev/null
+++ b/utils/lit/TestingConfig.py
@@ -0,0 +1,95 @@
+import os
+
+class TestingConfig:
+    """"
+    TestingConfig - Information on the tests inside a suite.
+    """
+
+    @staticmethod
+    def frompath(path, parent, litConfig, mustExist, config = None):
+        if config is None:
+            # Set the environment based on the command line arguments.
+            environment = {
+                'PATH' : os.pathsep.join(litConfig.path +
+                                         [os.environ.get('PATH','')]),
+                'SYSTEMROOT' : os.environ.get('SYSTEMROOT',''),
+                }
+
+            config = TestingConfig(parent,
+                                   name = '<unnamed>',
+                                   suffixes = set(),
+                                   test_format = None,
+                                   environment = environment,
+                                   substitutions = [],
+                                   unsupported = False,
+                                   on_clone = None,
+                                   test_exec_root = None,
+                                   test_source_root = None,
+                                   excludes = [])
+
+        if os.path.exists(path):
+            # FIXME: Improve detection and error reporting of errors in the
+            # config file.
+            f = open(path)
+            cfg_globals = dict(globals())
+            cfg_globals['config'] = config
+            cfg_globals['lit'] = litConfig
+            cfg_globals['__file__'] = path
+            try:
+                exec f in cfg_globals
+            except SystemExit,status:
+                # We allow normal system exit inside a config file to just
+                # return control without error.
+                if status.args:
+                    raise
+            f.close()
+        elif mustExist:
+            litConfig.fatal('unable to load config from %r ' % path)
+
+        config.finish(litConfig)
+        return config
+
+    def __init__(self, parent, name, suffixes, test_format,
+                 environment, substitutions, unsupported, on_clone,
+                 test_exec_root, test_source_root, excludes):
+        self.parent = parent
+        self.name = str(name)
+        self.suffixes = set(suffixes)
+        self.test_format = test_format
+        self.environment = dict(environment)
+        self.substitutions = list(substitutions)
+        self.unsupported = unsupported
+        self.on_clone = on_clone
+        self.test_exec_root = test_exec_root
+        self.test_source_root = test_source_root
+        self.excludes = set(excludes)
+
+    def clone(self, path):
+        # FIXME: Chain implementations?
+        #
+        # FIXME: Allow extra parameters?
+        cfg = TestingConfig(self, self.name, self.suffixes, self.test_format,
+                            self.environment, self.substitutions,
+                            self.unsupported, self.on_clone,
+                            self.test_exec_root, self.test_source_root,
+                            self.excludes)
+        if cfg.on_clone:
+            cfg.on_clone(self, cfg, path)
+        return cfg
+
+    def finish(self, litConfig):
+        """finish() - Finish this config object, after loading is complete."""
+
+        self.name = str(self.name)
+        self.suffixes = set(self.suffixes)
+        self.environment = dict(self.environment)
+        self.substitutions = list(self.substitutions)
+        if self.test_exec_root is not None:
+            # FIXME: This should really only be suite in test suite config
+            # files. Should we distinguish them?
+            self.test_exec_root = str(self.test_exec_root)
+        if self.test_source_root is not None:
+            # FIXME: This should really only be suite in test suite config
+            # files. Should we distinguish them?
+            self.test_source_root = str(self.test_source_root)
+        self.excludes = set(self.excludes)
diff --git a/utils/lit/Util.py b/utils/lit/Util.py
new file mode 100644
index 0000000..e62a8ed
--- /dev/null
+++ b/utils/lit/Util.py
@@ -0,0 +1,124 @@
+import os, sys
+
+def detectCPUs():
+    """
+    Detects the number of CPUs on a system. Cribbed from pp.
+    """
+    # Linux, Unix and MacOS:
+    if hasattr(os, "sysconf"):
+        if os.sysconf_names.has_key("SC_NPROCESSORS_ONLN"):
+            # Linux & Unix:
+            ncpus = os.sysconf("SC_NPROCESSORS_ONLN")
+            if isinstance(ncpus, int) and ncpus > 0:
+                return ncpus
+        else: # OSX:
+            return int(os.popen2("sysctl -n hw.ncpu")[1].read())
+    # Windows:
+    if os.environ.has_key("NUMBER_OF_PROCESSORS"):
+        ncpus = int(os.environ["NUMBER_OF_PROCESSORS"]);
+        if ncpus > 0:
+            return ncpus
+    return 1 # Default
+
+def mkdir_p(path):
+    """mkdir_p(path) - Make the "path" directory, if it does not exist; this
+    will also make directories for any missing parent directories."""
+    import errno
+
+    if not path or os.path.exists(path):
+        return
+
+    parent = os.path.dirname(path) 
+    if parent != path:
+        mkdir_p(parent)
+
+    try:
+        os.mkdir(path)
+    except OSError,e:
+        # Ignore EEXIST, which may occur during a race condition.
+        if e.errno != errno.EEXIST:
+            raise
+
+def capture(args):
+    import subprocess
+    """capture(command) - Run the given command (or argv list) in a shell and
+    return the standard output."""
+    p = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    out,_ = p.communicate()
+    return out
+
+def which(command, paths = None):
+    """which(command, [paths]) - Look up the given command in the paths string
+    (or the PATH environment variable, if unspecified)."""
+
+    if paths is None:
+        paths = os.environ.get('PATH','')
+
+    # Check for absolute match first.
+    if os.path.exists(command):
+        return command
+
+    # Would be nice if Python had a lib function for this.
+    if not paths:
+        paths = os.defpath
+
+    # Get suffixes to search.
+    pathext = os.environ.get('PATHEXT', '').split(os.pathsep)
+
+    # Search the paths...
+    for path in paths.split(os.pathsep):
+        for ext in pathext:
+            p = os.path.join(path, command + ext)
+            if os.path.exists(p):
+                return p
+
+    return None
+
+def printHistogram(items, title = 'Items'):
+    import itertools, math
+
+    items.sort(key = lambda (_,v): v)
+
+    maxValue = max([v for _,v in items])
+
+    # Select first "nice" bar height that produces more than 10 bars.
+    power = int(math.ceil(math.log(maxValue, 10)))
+    for inc in itertools.cycle((5, 2, 2.5, 1)):
+        barH = inc * 10**power
+        N = int(math.ceil(maxValue / barH))
+        if N > 10:
+            break
+        elif inc == 1:
+            power -= 1
+
+    histo = [set() for i in range(N)]
+    for name,v in items:
+        bin = min(int(N * v/maxValue), N-1)
+        histo[bin].add(name)
+
+    barW = 40
+    hr = '-' * (barW + 34)
+    print '\nSlowest %s:' % title
+    print hr
+    for name,value in items[-20:]:
+        print '%.2fs: %s' % (value, name)
+    print '\n%s Times:' % title
+    print hr
+    pDigits = int(math.ceil(math.log(maxValue, 10)))
+    pfDigits = max(0, 3-pDigits)
+    if pfDigits:
+        pDigits += pfDigits + 1
+    cDigits = int(math.ceil(math.log(len(items), 10)))
+    print "[%s] :: [%s] :: [%s]" % ('Range'.center((pDigits+1)*2 + 3),
+                                    'Percentage'.center(barW),
+                                    'Count'.center(cDigits*2 + 1))
+    print hr
+    for i,row in enumerate(histo):
+        pct = float(len(row)) / len(items)
+        w = int(barW * pct)
+        print "[%*.*fs,%*.*fs)" % (pDigits, pfDigits, i*barH,
+                                   pDigits, pfDigits, (i+1)*barH),
+        print ":: [%s%s] :: [%*d/%*d]" % ('*'*w, ' '*(barW-w),
+                                          cDigits, len(row),
+                                          cDigits, len(items))
+
diff --git a/utils/lit/lit.py b/utils/lit/lit.py
new file mode 100755
index 0000000..62ebf51
--- /dev/null
+++ b/utils/lit/lit.py
@@ -0,0 +1,519 @@
+#!/usr/bin/env python
+
+"""
+lit - LLVM Integrated Tester.
+
+See lit.pod for more information.
+"""
+
+import math, os, platform, random, re, sys, time, threading, traceback
+
+import ProgressBar
+import TestRunner
+import Util
+
+from TestingConfig import TestingConfig
+import LitConfig
+import Test
+
+# FIXME: Rename to 'config.lit', 'site.lit', and 'local.lit' ?
+kConfigName = 'lit.cfg'
+kSiteConfigName = 'lit.site.cfg'
+kLocalConfigName = 'lit.local.cfg'
+
+class TestingProgressDisplay:
+    def __init__(self, opts, numTests, progressBar=None):
+        self.opts = opts
+        self.numTests = numTests
+        self.current = None
+        self.lock = threading.Lock()
+        self.progressBar = progressBar
+        self.completed = 0
+
+    def update(self, test):
+        # Avoid locking overhead in quiet mode
+        if self.opts.quiet and not test.result.isFailure:
+            return
+
+        # Output lock.
+        self.lock.acquire()
+        try:
+            self.handleUpdate(test)
+        finally:
+            self.lock.release()
+
+    def finish(self):
+        if self.progressBar:
+            self.progressBar.clear()
+        elif self.opts.quiet:
+            pass
+        elif self.opts.succinct:
+            sys.stdout.write('\n')
+
+    def handleUpdate(self, test):
+        self.completed += 1
+        if self.progressBar:
+            self.progressBar.update(float(self.completed)/self.numTests,
+                                    test.getFullName())
+
+        if self.opts.succinct and not test.result.isFailure:
+            return
+
+        if self.progressBar:
+            self.progressBar.clear()
+
+        print '%s: %s (%d of %d)' % (test.result.name, test.getFullName(),
+                                     self.completed, self.numTests)
+
+        if test.result.isFailure and self.opts.showOutput:
+            print "%s TEST '%s' FAILED %s" % ('*'*20, test.getFullName(),
+                                              '*'*20)
+            print test.output
+            print "*" * 20
+
+        sys.stdout.flush()
+
+class TestProvider:
+    def __init__(self, tests, maxTime):
+        self.maxTime = maxTime
+        self.iter = iter(tests)
+        self.lock = threading.Lock()
+        self.startTime = time.time()
+
+    def get(self):
+        # Check if we have run out of time.
+        if self.maxTime is not None:
+            if time.time() - self.startTime > self.maxTime:
+                return None
+
+        # Otherwise take the next test.
+        self.lock.acquire()
+        try:
+            item = self.iter.next()
+        except StopIteration:
+            item = None
+        self.lock.release()
+        return item
+
+class Tester(threading.Thread):
+    def __init__(self, litConfig, provider, display):
+        threading.Thread.__init__(self)
+        self.litConfig = litConfig
+        self.provider = provider
+        self.display = display
+
+    def run(self):
+        while 1:
+            item = self.provider.get()
+            if item is None:
+                break
+            self.runTest(item)
+
+    def runTest(self, test):
+        result = None
+        startTime = time.time()
+        try:
+            result, output = test.config.test_format.execute(test,
+                                                             self.litConfig)
+        except KeyboardInterrupt:
+            # This is a sad hack. Unfortunately subprocess goes
+            # bonkers with ctrl-c and we start forking merrily.
+            print '\nCtrl-C detected, goodbye.'
+            os.kill(0,9)
+        except:
+            if self.litConfig.debug:
+                raise
+            result = Test.UNRESOLVED
+            output = 'Exception during script execution:\n'
+            output += traceback.format_exc()
+            output += '\n'
+        elapsed = time.time() - startTime
+
+        test.setResult(result, output, elapsed)
+        self.display.update(test)
+
+def dirContainsTestSuite(path):
+    cfgpath = os.path.join(path, kSiteConfigName)
+    if os.path.exists(cfgpath):
+        return cfgpath
+    cfgpath = os.path.join(path, kConfigName)
+    if os.path.exists(cfgpath):
+        return cfgpath
+
+def getTestSuite(item, litConfig, cache):
+    """getTestSuite(item, litConfig, cache) -> (suite, relative_path)
+
+    Find the test suite containing @arg item.
+
+    @retval (None, ...) - Indicates no test suite contains @arg item.
+    @retval (suite, relative_path) - The suite that @arg item is in, and its
+    relative path inside that suite.
+    """
+    def search1(path):
+        # Check for a site config or a lit config.
+        cfgpath = dirContainsTestSuite(path)
+
+        # If we didn't find a config file, keep looking.
+        if not cfgpath:
+            parent,base = os.path.split(path)
+            if parent == item:
+                return (None, ())
+
+            ts, relative = search(parent)
+            return (ts, relative + (base,))
+
+        # We found a config file, load it.
+        if litConfig.debug:
+            litConfig.note('loading suite config %r' % cfgpath)
+
+        cfg = TestingConfig.frompath(cfgpath, None, litConfig, mustExist = True)
+        source_root = os.path.realpath(cfg.test_source_root or path)
+        exec_root = os.path.realpath(cfg.test_exec_root or path)
+        return Test.TestSuite(cfg.name, source_root, exec_root, cfg), ()
+
+    def search(path):
+        # Check for an already instantiated test suite.
+        res = cache.get(path)
+        if res is None:
+            cache[path] = res = search1(path)
+        return res
+
+    # Canonicalize the path.
+    item = os.path.realpath(item)
+
+    # Skip files and virtual components.
+    components = []
+    while not os.path.isdir(item):
+        parent,base = os.path.split(item)
+        if parent == item:
+            return (None, ())
+        components.append(base)
+        item = parent
+    components.reverse()
+
+    ts, relative = search(item)
+    return ts, tuple(relative + tuple(components))
+
+def getLocalConfig(ts, path_in_suite, litConfig, cache):
+    def search1(path_in_suite):
+        # Get the parent config.
+        if not path_in_suite:
+            parent = ts.config
+        else:
+            parent = search(path_in_suite[:-1])
+
+        # Load the local configuration.
+        source_path = ts.getSourcePath(path_in_suite)
+        cfgpath = os.path.join(source_path, kLocalConfigName)
+        if litConfig.debug:
+            litConfig.note('loading local config %r' % cfgpath)
+        return TestingConfig.frompath(cfgpath, parent, litConfig,
+                                    mustExist = False,
+                                    config = parent.clone(cfgpath))
+
+    def search(path_in_suite):
+        key = (ts, path_in_suite)
+        res = cache.get(key)
+        if res is None:
+            cache[key] = res = search1(path_in_suite)
+        return res
+
+    return search(path_in_suite)
+
+def getTests(path, litConfig, testSuiteCache, localConfigCache):
+    # Find the test suite for this input and its relative path.
+    ts,path_in_suite = getTestSuite(path, litConfig, testSuiteCache)
+    if ts is None:
+        litConfig.warning('unable to find test suite for %r' % path)
+        return ()
+
+    if litConfig.debug:
+        litConfig.note('resolved input %r to %r::%r' % (path, ts.name,
+                                                        path_in_suite))
+
+    return getTestsInSuite(ts, path_in_suite, litConfig,
+                           testSuiteCache, localConfigCache)
+
+def getTestsInSuite(ts, path_in_suite, litConfig,
+                    testSuiteCache, localConfigCache):
+    # Check that the source path exists (errors here are reported by the
+    # caller).
+    source_path = ts.getSourcePath(path_in_suite)
+    if not os.path.exists(source_path):
+        return
+
+    # Check if the user named a test directly.
+    if not os.path.isdir(source_path):
+        lc = getLocalConfig(ts, path_in_suite[:-1], litConfig, localConfigCache)
+        yield Test.Test(ts, path_in_suite, lc)
+        return
+
+    # Otherwise we have a directory to search for tests, start by getting the
+    # local configuration.
+    lc = getLocalConfig(ts, path_in_suite, litConfig, localConfigCache)
+    for filename in os.listdir(source_path):
+        # FIXME: This doesn't belong here?
+        if filename == 'Output' or filename in lc.excludes:
+            continue
+
+        filepath = os.path.join(source_path, filename)
+        if os.path.isdir(filepath):
+            # If this directory contains a test suite, reload it.
+            if dirContainsTestSuite(filepath):
+                for res in getTests(filepath, litConfig,
+                                    testSuiteCache, localConfigCache):
+                    yield res
+            else:
+                # Otherwise, continue loading from inside this test suite.
+                for res in getTestsInSuite(ts, path_in_suite + (filename,),
+                                           litConfig, testSuiteCache,
+                                           localConfigCache):
+                    yield res
+        else:
+            # Otherwise add tests for matching suffixes.
+            base,ext = os.path.splitext(filename)
+            if ext in lc.suffixes:
+                yield Test.Test(ts, path_in_suite + (filename,), lc)
+
+def runTests(numThreads, litConfig, provider, display):
+    # If only using one testing thread, don't use threads at all; this lets us
+    # profile, among other things.
+    if numThreads == 1:
+        t = Tester(litConfig, provider, display)
+        t.run()
+        return
+
+    # Otherwise spin up the testing threads and wait for them to finish.
+    testers = [Tester(litConfig, provider, display)
+               for i in range(numThreads)]
+    for t in testers:
+        t.start()
+    try:
+        for t in testers:
+            t.join()
+    except KeyboardInterrupt:
+        sys.exit(2)
+
+def main():
+    global options
+    from optparse import OptionParser, OptionGroup
+    parser = OptionParser("usage: %prog [options] {file-or-path}")
+
+    parser.add_option("-j", "--threads", dest="numThreads", metavar="N",
+                      help="Number of testing threads",
+                      type=int, action="store", default=None)
+
+    group = OptionGroup(parser, "Output Format")
+    # FIXME: I find these names very confusing, although I like the
+    # functionality.
+    group.add_option("-q", "--quiet", dest="quiet",
+                     help="Suppress no error output",
+                     action="store_true", default=False)
+    group.add_option("-s", "--succinct", dest="succinct",
+                     help="Reduce amount of output",
+                     action="store_true", default=False)
+    group.add_option("-v", "--verbose", dest="showOutput",
+                     help="Show all test output",
+                     action="store_true", default=False)
+    group.add_option("", "--no-progress-bar", dest="useProgressBar",
+                     help="Do not use curses based progress bar",
+                     action="store_false", default=True)
+    parser.add_option_group(group)
+
+    group = OptionGroup(parser, "Test Execution")
+    group.add_option("", "--path", dest="path",
+                     help="Additional paths to add to testing environment",
+                     action="append", type=str, default=[])
+    group.add_option("", "--vg", dest="useValgrind",
+                     help="Run tests under valgrind",
+                     action="store_true", default=False)
+    group.add_option("", "--vg-arg", dest="valgrindArgs", metavar="ARG",
+                     help="Specify an extra argument for valgrind",
+                     type=str, action="append", default=[])
+    group.add_option("", "--time-tests", dest="timeTests",
+                     help="Track elapsed wall time for each test",
+                     action="store_true", default=False)
+    group.add_option("", "--no-execute", dest="noExecute",
+                     help="Don't execute any tests (assume PASS)",
+                     action="store_true", default=False)
+    parser.add_option_group(group)
+
+    group = OptionGroup(parser, "Test Selection")
+    group.add_option("", "--max-tests", dest="maxTests", metavar="N",
+                     help="Maximum number of tests to run",
+                     action="store", type=int, default=None)
+    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("", "--shuffle", dest="shuffle",
+                     help="Run tests in random order",
+                     action="store_true", default=False)
+    parser.add_option_group(group)
+
+    group = OptionGroup(parser, "Debug and Experimental Options")
+    group.add_option("", "--debug", dest="debug",
+                      help="Enable debugging (for 'lit' development)",
+                      action="store_true", default=False)
+    group.add_option("", "--show-suites", dest="showSuites",
+                      help="Show discovered test suites",
+                      action="store_true", default=False)
+    group.add_option("", "--no-tcl-as-sh", dest="useTclAsSh",
+                      help="Don't run Tcl scripts using 'sh'",
+                      action="store_false", default=True)
+    parser.add_option_group(group)
+
+    (opts, args) = parser.parse_args()
+
+    if not args:
+        parser.error('No inputs specified')
+
+    if opts.numThreads is None:
+        opts.numThreads = Util.detectCPUs()
+
+    inputs = args
+
+    # Create the global config object.
+    litConfig = LitConfig.LitConfig(progname = os.path.basename(sys.argv[0]),
+                                    path = opts.path,
+                                    quiet = opts.quiet,
+                                    useValgrind = opts.useValgrind,
+                                    valgrindArgs = opts.valgrindArgs,
+                                    useTclAsSh = opts.useTclAsSh,
+                                    noExecute = opts.noExecute,
+                                    debug = opts.debug,
+                                    isWindows = (platform.system()=='Windows'))
+
+    # Load the tests from the inputs.
+    tests = []
+    testSuiteCache = {}
+    localConfigCache = {}
+    for input in inputs:
+        prev = len(tests)
+        tests.extend(getTests(input, litConfig,
+                              testSuiteCache, localConfigCache))
+        if prev == len(tests):
+            litConfig.warning('input %r contained no tests' % input)
+
+    # If there were any errors during test discovery, exit now.
+    if litConfig.numErrors:
+        print >>sys.stderr, '%d errors, exiting.' % litConfig.numErrors
+        sys.exit(2)
+
+    if opts.showSuites:
+        suitesAndTests = dict([(ts,[])
+                               for ts,_ in testSuiteCache.values()])
+        for t in tests:
+            suitesAndTests[t.suite].append(t)
+
+        print '-- Test Suites --'
+        suitesAndTests = suitesAndTests.items()
+        suitesAndTests.sort(key = lambda (ts,_): ts.name)
+        for ts,tests in suitesAndTests:
+            print '  %s - %d tests' %(ts.name, len(tests))
+            print '    Source Root: %s' % ts.source_root
+            print '    Exec Root  : %s' % ts.exec_root
+
+    # Select and order the tests.
+    numTotalTests = len(tests)
+    if opts.shuffle:
+        random.shuffle(tests)
+    else:
+        tests.sort(key = lambda t: t.getFullName())
+    if opts.maxTests is not None:
+        tests = tests[:opts.maxTests]
+
+    extra = ''
+    if len(tests) != numTotalTests:
+        extra = ' of %d' % numTotalTests
+    header = '-- Testing: %d%s tests, %d threads --'%(len(tests),extra,
+                                                      opts.numThreads)
+
+    progressBar = None
+    if not opts.quiet:
+        if opts.succinct and opts.useProgressBar:
+            try:
+                tc = ProgressBar.TerminalController()
+                progressBar = ProgressBar.ProgressBar(tc, header)
+            except ValueError:
+                print header
+                progressBar = ProgressBar.SimpleProgressBar('Testing: ')
+        else:
+            print header
+
+    # Don't create more threads than tests.
+    opts.numThreads = min(len(tests), opts.numThreads)
+
+    startTime = time.time()
+    display = TestingProgressDisplay(opts, len(tests), progressBar)
+    provider = TestProvider(tests, opts.maxTime)
+    runTests(opts.numThreads, litConfig, provider, display)
+    display.finish()
+
+    if not opts.quiet:
+        print 'Testing Time: %.2fs'%(time.time() - startTime)
+
+    # Update results for any tests which weren't run.
+    for t in tests:
+        if t.result is None:
+            t.setResult(Test.UNRESOLVED, '', 0.0)
+
+    # List test results organized by kind.
+    hasFailures = False
+    byCode = {}
+    for t in tests:
+        if t.result not in byCode:
+            byCode[t.result] = []
+        byCode[t.result].append(t)
+        if t.result.isFailure:
+            hasFailures = True
+
+    # FIXME: Show unresolved and (optionally) unsupported tests.
+    for title,code in (('Unexpected Passing Tests', Test.XPASS),
+                       ('Failing Tests', Test.FAIL)):
+        elts = byCode.get(code)
+        if not elts:
+            continue
+        print '*'*20
+        print '%s (%d):' % (title, len(elts))
+        for t in elts:
+            print '    %s' % t.getFullName()
+        print
+
+    if opts.timeTests:
+        byTime = list(tests)
+        byTime.sort(key = lambda t: t.elapsed)
+        if byTime:
+            Util.printHistogram([(t.getFullName(), t.elapsed) for t in byTime],
+                                title='Tests')
+
+    for name,code in (('Expected Passes    ', Test.PASS),
+                      ('Expected Failures  ', Test.XFAIL),
+                      ('Unsupported Tests  ', Test.UNSUPPORTED),
+                      ('Unresolved Tests   ', Test.UNRESOLVED),
+                      ('Unexpected Passes  ', Test.XPASS),
+                      ('Unexpected Failures', Test.FAIL),):
+        if opts.quiet and not code.isFailure:
+            continue
+        N = len(byCode.get(code,[]))
+        if N:
+            print '  %s: %d' % (name,N)
+
+    # If we encountered any additional errors, exit abnormally.
+    if litConfig.numErrors:
+        print >>sys.stderr, '\n%d error(s), exiting.' % litConfig.numErrors
+        sys.exit(2)
+
+    # Warn about warnings.
+    if litConfig.numWarnings:
+        print >>sys.stderr, '\n%d warning(s) in tests.' % litConfig.numWarnings
+
+    if hasFailures:
+        sys.exit(1)
+    sys.exit(0)
+
+if __name__=='__main__':
+    # Bump the GIL check interval, its more important to get any one thread to a
+    # blocking operation (hopefully exec) than to try and unblock other threads.
+    import sys
+    sys.setcheckinterval(1000)
+    main()