diff -r 000000000000 -r 6474c204b198 mobile/android/base/jni-generator.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/jni-generator.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,109 @@
+# 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 argparse
+import re
+
+STUB_TEMPLATE = '''
+typedef %(returnType)s (*%(functionName)s_t)(%(paramTypes)s);
+static %(functionName)s_t f_%(functionName)s;
+extern "C" NS_EXPORT %(returnType)s JNICALL
+%(functionName)s(%(parameterList)s) {
+    if (!f_%(functionName)s) {
+        arg0->ThrowNew(arg0->FindClass("java/lang/UnsupportedOperationException"),
+                       "JNI Function called before it was loaded");
+        return %(returnValue)s;
+    }
+    %(returnKeyword)s f_%(functionName)s(%(arguments)s);
+}
+'''
+BINDING_TEMPLATE = '  xul_dlsym("%(functionName)s", &f_%(functionName)s);\n'
+
+
+class Generator:
+    """
+    Class to convert a javah-produced JNI stub file into stubs/bindings files
+    for inclusion into mozglue.
+    """
+    def __init__(self, outputfile):
+        self.outputfile = outputfile
+
+    def write(self, guard, stuff):
+        self.outputfile.write('#ifdef %s\n' % guard)
+        self.outputfile.write(stuff)
+        self.outputfile.write('#endif\n\n')
+
+    def process(self, inputfile):
+        self.outputfile.write('/* WARNING - This file is autogenerated by '
+                              + 'mobile/android/base/jni-generator.py. '
+                              + 'Do not edit manually! */\n')
+
+        # this matches lines such as:
+        # JNIEXPORT void JNICALL Java_org_mozilla_gecko_GeckoAppShell_onResume
+        # and extracts the return type and the function name
+        nameRegex = re.compile('''JNIEXPORT \s+
+                                  (?P<returnType>\S+) \s+
+                                  JNICALL \s+
+                                  (?P<functionName>\S+)''', re.VERBOSE)
+
+        # this matches lines such as:
+        #   (JNIEnv *, jclass);
+        # and extracts everything within the parens; this will be split
+        # on commas to get the argument types.
+        paramsRegex = re.compile('\((.*)\);')
+
+        for line in inputfile:
+            line = line.strip()
+
+            match = re.match(nameRegex, line)
+            if match:
+                returnType = match.group('returnType')
+                functionName = match.group('functionName')
+
+            match = re.match(paramsRegex, line)
+            if match:
+                paramTypes = re.split('\s*,\s*', match.group(1))
+                paramNames = ['arg%d' % i for i in range(0, len(paramTypes))]
+                if returnType == 'void':
+                    returnValue = ''
+                elif returnType in ('jobject', 'jstring'):
+                    returnValue = 'nullptr'
+                elif returnType in ('jint', 'jfloat', 'jdouble', 'jlong'):
+                    returnValue = '0'
+                elif returnType == 'jboolean':
+                    returnValue = 'false'
+                else:
+                    raise Exception(('Unsupported JNI return type %s found; '
+                                     + 'please update mobile/android/base/'
+                                     + 'jni-generator.py to handle this case!')
+                                    % returnType)
+
+                self.write('JNI_STUBS', STUB_TEMPLATE % {
+                    'returnType': returnType,
+                    'functionName': functionName,
+                    'paramTypes': ', '.join(paramTypes),
+                    'parameterList': ', '.join('%s %s' % param
+                                     for param in zip(paramTypes, paramNames)),
+                    'arguments': ', '.join(paramNames),
+                    'returnValue': returnValue,
+                    'returnKeyword': 'return' if returnType != 'void' else ''})
+                self.write('JNI_BINDINGS', BINDING_TEMPLATE % {
+                    'functionName': functionName})
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description='Generate mozglue bindings for JNI functions.')
+    parser.add_argument('inputfile', type=argparse.FileType('r'))
+    parser.add_argument('outputfile', type=argparse.FileType('w'))
+    args = parser.parse_args()
+    gen = Generator(args.outputfile)
+    try:
+        gen.process(args.inputfile)
+    finally:
+        args.outputfile.close()
+        args.inputfile.close()
+
+if __name__ == '__main__':
+    main()