diff -r 000000000000 -r 6474c204b198 build/gen_mach_buildprops.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/build/gen_mach_buildprops.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,115 @@
+#!/usr/bin/python
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import sys
+import os
+import hashlib
+import json
+import re
+import errno
+from argparse import ArgumentParser
+
+def getFileHashAndSize(filename):
+    sha512Hash = 'UNKNOWN'
+    size = 'UNKNOWN'
+
+    try:
+        # open in binary mode to make sure we get consistent results
+        # across all platforms
+        f = open(filename, "rb")
+        shaObj = hashlib.sha512(f.read())
+        sha512Hash = shaObj.hexdigest()
+
+        size = os.path.getsize(filename)
+    except:
+        pass
+
+    return (sha512Hash, size)
+
+def getMarProperties(filename, partial=False):
+    if not os.path.exists(filename):
+        return {}
+    (mar_hash, mar_size) = getFileHashAndSize(filename)
+    martype = 'partial' if partial else 'complete'
+    return {
+        '%sMarFilename' % martype: os.path.basename(filename),
+        '%sMarSize' % martype: mar_size,
+        '%sMarHash' % martype: mar_hash,
+    }
+
+def getUrlProperties(filename):
+    # let's create a switch case using name-spaces/dict
+    # rather than a long if/else with duplicate code
+    property_conditions = [
+        # key: property name, value: condition
+        ('symbolsUrl', lambda m: m.endswith('crashreporter-symbols.zip') or
+                       m.endswith('crashreporter-symbols-full.zip')),
+        ('testsUrl', lambda m: m.endswith(('tests.tar.bz2', 'tests.zip'))),
+        ('unsignedApkUrl', lambda m: m.endswith('apk') and
+                           'unsigned-unaligned' in m),
+        ('robocopApkUrl', lambda m: m.endswith('apk') and 'robocop' in m),
+        ('jsshellUrl', lambda m: 'jsshell-' in m and m.endswith('.zip')),
+        ('completeMarUrl', lambda m: m.endswith('.complete.mar')),
+        ('partialMarUrl', lambda m: m.endswith('.mar') and '.partial.' in m),
+        # packageUrl must be last!
+        ('packageUrl', lambda m: True),
+    ]
+    url_re = re.compile(r'''^(https?://.*?\.(?:tar\.bz2|dmg|zip|apk|rpm|mar|tar\.gz))$''')
+    properties = {}
+
+    try:
+        with open(filename) as f:
+            for line in f:
+                m = url_re.match(line)
+                if m:
+                    m = m.group(1)
+                    for prop, condition in property_conditions:
+                        if condition(m):
+                            properties.update({prop: m})
+                            break
+    except IOError as e:
+        if e.errno != errno.ENOENT:
+            raise
+        properties = {prop: 'UNKNOWN' for prop, condition in property_conditions}
+    return properties
+
+def getPartialInfo(props):
+    return [{
+        "from_buildid": props.get("previous_buildid"),
+        "size": props.get("partialMarSize"),
+        "hash": props.get("partialMarHash"),
+        "url": props.get("partialMarUrl"),
+    }]
+
+if __name__ == '__main__':
+    parser = ArgumentParser(description='Generate mach_build_properties.json for automation builds.')
+    parser.add_argument("--complete-mar-file", required=True,
+                        action="store", dest="complete_mar_file",
+                        help="Path to the complete MAR file, relative to the objdir.")
+    parser.add_argument("--partial-mar-file", required=False,
+                        action="store", dest="partial_mar_file",
+                        help="Path to the partial MAR file, relative to the objdir.")
+    parser.add_argument("--upload-output", required=True,
+                        action="store", dest="upload_output",
+                        help="Path to the text output of 'make upload'")
+    args = parser.parse_args()
+
+    json_data = getMarProperties(args.complete_mar_file)
+    json_data.update(getUrlProperties(args.upload_output))
+    if args.partial_mar_file:
+        json_data.update(getMarProperties(args.partial_mar_file, partial=True))
+
+        # Pull the previous buildid from the partial mar filename.
+        res = re.match(r'.*\.([0-9]+)-[0-9]+.mar', args.partial_mar_file)
+        if res:
+            json_data['previous_buildid'] = res.group(1)
+
+            # Set partialInfo to be a collection of the partial mar properties
+            # useful for balrog.
+            json_data['partialInfo'] = getPartialInfo(json_data)
+
+    with open('mach_build_properties.json', 'w') as outfile:
+        json.dump(json_data, outfile, indent=4)