Index: test/AST/gen_ast_dump_json_test.py
===================================================================
--- test/AST/gen_ast_dump_json_test.py
+++ test/AST/gen_ast_dump_json_test.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+
+from collections import OrderedDict
+from sets import Set
+from shutil import copyfile
+import argparse
+import json
+import os
+import pprint
+import re
+import subprocess
+    
+def normalize(dict_var):
+    for k, v in dict_var.items():
+        if isinstance(v, OrderedDict):
+            normalize(v)
+        elif isinstance(v, list):
+            for e in v:
+                if isinstance(e, OrderedDict):
+                    normalize(e)
+        elif type(v) is unicode:
+            st = v.encode('utf-8')
+            if re.match(r"0x[0-9A-Fa-f]+", v):
+                dict_var[k] = u'0x{{.*}}'
+            elif os.path.isfile(v):
+                dict_var[k] = u'{{.*}}'
+            else:
+                splits = (v.split(u' '))
+                out_splits = []
+                for split in splits:
+                    inner_splits = split.rsplit(u':',2)
+                    if os.path.isfile(inner_splits[0]):
+                        out_splits.append(
+                            u'{{.*}}:%s:%s'
+                            %(inner_splits[1],
+                              inner_splits[2]))
+                        continue
+                    out_splits.append(split)
+
+                dict_var[k] = ' '.join(out_splits)
+
+def filter_json(dict_var, filters, out):
+    for k, v in dict_var.items():
+        if type(v) is unicode:
+            st = v.encode('utf-8')
+            if st in filters:
+                out.append(dict_var)
+                break
+        elif isinstance(v, OrderedDict):
+            filter_json(v, filters, out)
+        elif isinstance(v, list):
+            for e in v:
+                if isinstance(e, OrderedDict):
+                    filter_json(e, filters, out)
+                
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--clang", help="The clang binary (could be a relative or absolute path)",
+                        action="store", required=True)
+    parser.add_argument("--opts", help="other options",
+                        action="store", default='', type=str)
+    parser.add_argument("--source", help="the source file. Command used to generate the json will be of the format <clang> -cc1 -ast-dump=json <opts> <source>",
+                        action="store", required=True)
+    parser.add_argument("--filters", help="comma separated list of AST filters. Ex: --filters=TypedefDecl,BuiltinType",
+                        action="store", default='')
+
+    args = parser.parse_args()
+
+    if not args.source:
+        print("Specify the source file to give to clang.")
+        return -1
+
+    clang_binary = os.path.abspath(args.clang)
+    if not os.path.isfile(clang_binary):
+        print("clang binary specified not present.")
+        return -1
+
+    options = args.opts.split(' ')
+    filters = Set(args.filters.split(',')) if args.filters else Set([])
+    
+    cmd = [clang_binary, "-cc1"]
+    cmd.extend(options)
+
+    using_ast_dump_filter = 'ast-dump-filter' in args.opts
+        
+    cmd.extend(["-ast-dump=json", args.source])
+
+    try:
+        json_str = subprocess.check_output(cmd)
+    except Exception as ex:
+        print("The clang command failed with %s" % ex)
+        return -1
+    
+    out_asts = []
+    if using_ast_dump_filter:
+        splits = re.split('Dumping .*:\n', json_str)
+        if len(splits) > 1:
+            for split in splits[1:]:
+                j = json.loads(split.decode('utf-8'), object_pairs_hook=OrderedDict)
+                normalize(j)
+                out_asts.append(j)
+    else:
+        j = json.loads(json_str.decode('utf-8'), object_pairs_hook=OrderedDict)
+        normalize(j)
+
+        if len(filters) == 0:
+            out_asts.append(j)
+        else:
+            #assert using_ast_dump_filter is False,\
+            #    "Does not support using compiler's ast-dump-filter "\
+            #    "and the tool's filter option at the same time yet."
+        
+            filter_json(j, filters, out_asts)
+        
+    partition = args.source.rpartition('.')
+    dest_path = '%s-json%s%s' % (partition[0], partition[1], partition[2])
+
+    print("Writing json appended source file to %s." %(dest_path))
+    copyfile(args.source, dest_path)    
+    with open(dest_path, "a") as f:
+        for out_ast in out_asts:
+            append_str = json.dumps(out_ast, indent=1, ensure_ascii=False)
+            out_str = '\n\n'
+            index = 0
+            for append_line in append_str.splitlines()[2:]:
+                if index == 0:
+                    out_str += '// CHECK: %s\n' %(append_line)
+                    index += 1
+                else:
+                    out_str += '// CHECK-NEXT: %s\n' %(append_line)
+                    
+            f.write(out_str)
+    
+    return 0
+        
+if __name__ == '__main__':
+    main()