Index: utils/clangdiag.py
===================================================================
--- /dev/null
+++ utils/clangdiag.py
@@ -0,0 +1,131 @@
+#!/usr/bin/python
+
+#----------------------------------------------------------------------
+# Be sure to add the python path that points to the LLDB shared library.
+#
+# # To use this in the embedded python interpreter using "lldb" just
+# import it with the full path using the "command script import"
+# command
+#   (lldb) command script import /path/to/clandiag.py
+#----------------------------------------------------------------------
+
+import lldb
+import argparse
+import commands
+import shlex
+import os
+import subprocess
+
+class MyParser(argparse.ArgumentParser):
+    def format_help(self):
+        return '''     Commands for operating on clang diagnostic breakpoints
+
+Syntax: clangdiag enable
+        clangdiag disable
+        clangdiag diagtool <path>
+
+The following subcommands are supported:
+
+      enable   -- Enable clang diagnostic breakpoints.
+      disable  -- Disable all clang diagnostic breakpoints.
+      diagtool -- Set diagtool path if not in target directory.
+'''
+
+def create_diag_options():
+    parser = MyParser(prog='clangdiag')
+    subparsers = parser.add_subparsers(
+        title='subcommands',
+        dest='subcommands',
+        metavar='')
+    disable_parser = subparsers.add_parser('disable')
+    enable_parser = subparsers.add_parser('enable')
+    diagtool_parser = subparsers.add_parser('diagtool')
+    diagtool_parser.add_argument('path', nargs=1)
+    return parser
+
+def getDiagtool(target, diagtool = None):
+    if 'diagtool' not in getDiagtool.__dict__:
+        getDiagtool.diagtool = None
+    if diagtool:
+        getDiagtool.diagtool = diagtool
+    elif getDiagtool.diagtool is None:
+        exe = target.GetExecutable()
+        if not exe.Exists():
+            print('clangdiag: Target (%s) not set.' % exe.GetFilename())
+            return
+        diagtool = os.path.join(exe.GetDirectory(), 'diagtool')
+        if os.path.exists(diagtool):
+            getDiagtool.diagtool = diagtool
+        else:
+            print('clangdiag: diagtool not found along side %s' % exe)
+            return
+
+    return getDiagtool.diagtool
+
+def setDiagBreakpoint(frame, bp_loc, dict):
+    id = frame.FindVariable("DiagID").GetValue()
+    if id is None:
+         print('clangdiag: id is None')
+         return False
+
+    # Don't need to test this time, since we did that in enable.
+    target = frame.GetThread().GetProcess().GetTarget()
+    diagtool = getDiagtool(target)
+    name = subprocess.check_output([diagtool, "find-diagnostic-id", id]).rstrip();
+    bp = target.BreakpointCreateBySourceRegex(name, lldb.SBFileSpec())
+    bp.AddName("clang::Diagnostic")
+
+    return False
+
+def enable(exe_ctx, args):
+    # Always disable existing breakpoints
+    disable(exe_ctx)
+
+    target = exe_ctx.GetTarget()
+    # Just make sure we can find diagtool since it gets used in callbacks.
+    diagtool = getDiagtool(target)
+    bp = target.BreakpointCreateByName('DiagnosticsEngine::Report')
+    bp.SetScriptCallbackFunction('clangdiag.setDiagBreakpoint')
+    bp.AddName("clang::Diagnostic")
+
+    return
+
+def disable(exe_ctx):
+    target = exe_ctx.GetTarget()
+    # Remove all diag breakpoints.
+    bkpts = lldb.SBBreakpointList(target)
+    target.FindBreakpointsByName("clang::Diagnostic", bkpts)
+    for i in range(bkpts.GetSize()):
+        target.BreakpointDelete(bkpts.GetBreakpointAtIndex(i).GetID())
+
+    return
+
+def the_diag_command(debugger, command, exe_ctx, result, dict):
+    # Use the Shell Lexer to properly parse up command options just like a
+    # shell would
+    command_args = shlex.split(command)
+    parser = create_diag_options()
+    try:
+        args = parser.parse_args(command_args)
+    except:
+        return
+
+    if args.subcommands == 'enable':
+        enable(exe_ctx, args)
+    elif args.subcommands == 'disable':
+        disable(exe_ctx)
+    else:
+        getDiagtool(exe_ctx.GetTarget(), args.path[0])
+        
+    return
+
+def __lldb_init_module(debugger, dict):
+    # This initializer is being run from LLDB in the embedded command interpreter
+    # Make the options so we can generate the help text for the new LLDB
+    # command line command prior to registering it with LLDB below
+    parser = create_diag_options()
+    the_diag_command.__doc__ = parser.format_help()
+    # Add any commands contained in this module to LLDB
+    debugger.HandleCommand(
+        'command script add -f clangdiag.the_diag_command clangdiag')
+    print 'The "clangdiag" command has been installed, type "help clangdiag" or "clangdiag --help" for detailed help.'