blob: 99d8b424f02db8a4753ba96c29cc83c66d26de9b [file] [log] [blame]
#!/usr/bin/env python
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Extracts native methods from a Java file and generates the JNI bindings.
If you change this, please run and update the tests."""
import collections
import errno
import optparse
import os
import re
import string
from string import Template
import subprocess
import sys
import textwrap
import zipfile
CHROMIUM_SRC = os.path.join(
os.path.dirname(__file__), os.pardir, os.pardir, os.pardir)
BUILD_ANDROID_GYP = os.path.join(
CHROMIUM_SRC, 'build', 'android', 'gyp')
from util import build_utils
class ParseError(Exception):
"""Exception thrown when we can't parse the input file."""
def __init__(self, description, *context_lines):
self.description = description
self.context_lines = context_lines
def __str__(self):
context = '\n'.join(self.context_lines)
return '***\nERROR: %s\n\n%s\n***' % (self.description, context)
class Param(object):
"""Describes a param for a method, either java or native."""
def __init__(self, **kwargs):
self.datatype = kwargs['datatype'] = kwargs['name']
class NativeMethod(object):
"""Describes a C/C++ method that is called by Java code"""
def __init__(self, **kwargs):
self.static = kwargs['static']
self.java_class_name = kwargs['java_class_name']
self.return_type = kwargs['return_type'] = kwargs['name']
self.params = kwargs['params']
if self.params:
assert type(self.params) is list
assert type(self.params[0]) is Param
if (self.params and
self.params[0].datatype == kwargs.get('ptr_type', 'int') and
self.type = 'method'
self.p0_type = self.params[0].name[len('native'):]
if kwargs.get('native_class_name'):
self.p0_type = kwargs['native_class_name']
self.type = 'function'
self.method_id_var_name = kwargs.get('method_id_var_name', None)
class CalledByNative(object):
"""Describes a java method exported to c/c++"""
def __init__(self, **kwargs):
self.system_class = kwargs['system_class']
self.unchecked = kwargs['unchecked']
self.static = kwargs['static']
self.java_class_name = kwargs['java_class_name']
self.return_type = kwargs['return_type'] = kwargs['name']
self.params = kwargs['params']
self.method_id_var_name = kwargs.get('method_id_var_name', None)
self.signature = kwargs.get('signature')
self.is_constructor = kwargs.get('is_constructor', False)
self.env_call = GetEnvCall(self.is_constructor, self.static,
self.static_cast = GetStaticCastForReturnType(self.return_type)
class ConstantField(object):
def __init__(self, **kwargs): = kwargs['name']
self.value = kwargs['value']
def JavaDataTypeToC(java_type):
"""Returns a C datatype for the given java type."""
java_pod_type_map = {
'int': 'jint',
'byte': 'jbyte',
'char': 'jchar',
'short': 'jshort',
'boolean': 'jboolean',
'long': 'jlong',
'double': 'jdouble',
'float': 'jfloat',
java_type_map = {
'void': 'void',
'String': 'jstring',
'Throwable': 'jthrowable',
'java/lang/String': 'jstring',
'java/lang/Class': 'jclass',
'java/lang/Throwable': 'jthrowable',
if java_type in java_pod_type_map:
return java_pod_type_map[java_type]
elif java_type in java_type_map:
return java_type_map[java_type]
elif java_type.endswith('[]'):
if java_type[:-2] in java_pod_type_map:
return java_pod_type_map[java_type[:-2]] + 'Array'
return 'jobjectArray'
elif java_type.startswith('Class'):
# Checking just the start of the name, rather than a direct comparison,
# in order to handle generics.
return 'jclass'
return 'jobject'
def WrapCTypeForDeclaration(c_type):
"""Wrap the C datatype in a JavaRef if required."""
if re.match(RE_SCOPED_JNI_TYPES, c_type):
return 'const base::android::JavaParamRef<' + c_type + '>&'
return c_type
def JavaDataTypeToCForDeclaration(java_type):
"""Returns a JavaRef-wrapped C datatype for the given java type."""
return WrapCTypeForDeclaration(JavaDataTypeToC(java_type))
def JavaDataTypeToCForCalledByNativeParam(java_type):
"""Returns a C datatype to be when calling from native."""
if java_type == 'int':
return 'JniIntWrapper'
c_type = JavaDataTypeToC(java_type)
if re.match(RE_SCOPED_JNI_TYPES, c_type):
return 'const base::android::JavaRefOrBare<' + c_type + '>&'
return c_type
def JavaReturnValueToC(java_type):
"""Returns a valid C return value for the given java type."""
java_pod_type_map = {
'int': '0',
'byte': '0',
'char': '0',
'short': '0',
'boolean': 'false',
'long': '0',
'double': '0',
'float': '0',
'void': ''
return java_pod_type_map.get(java_type, 'NULL')
class JniParams(object):
_imports = []
_fully_qualified_class = ''
_package = ''
_inner_classes = []
_implicit_imports = []
def SetFullyQualifiedClass(fully_qualified_class):
JniParams._fully_qualified_class = 'L' + fully_qualified_class
JniParams._package = '/'.join(fully_qualified_class.split('/')[:-1])
def AddAdditionalImport(class_name):
assert class_name.endswith('.class')
raw_class_name = class_name[:-len('.class')]
if '.' in raw_class_name:
raise SyntaxError('%s cannot be used in @JNIAdditionalImport. '
'Only import unqualified outer classes.' % class_name)
new_import = 'L%s/%s' % (JniParams._package, raw_class_name)
if new_import in JniParams._imports:
raise SyntaxError('Do not use JNIAdditionalImport on an already '
'imported class: %s' % (new_import.replace('/', '.')))
JniParams._imports += [new_import]
def ExtractImportsAndInnerClasses(contents):
if not JniParams._package:
raise RuntimeError('SetFullyQualifiedClass must be called before '
contents = contents.replace('\n', '')
re_import = re.compile(r'import.*?(?P<class>\S*?);')
for match in re.finditer(re_import, contents):
JniParams._imports += ['L' +'class').replace('.', '/')]
re_inner = re.compile(r'(class|interface)\s+?(?P<name>\w+?)\W')
for match in re.finditer(re_inner, contents):
inner ='name')
if not JniParams._fully_qualified_class.endswith(inner):
JniParams._inner_classes += [JniParams._fully_qualified_class + '$' +
re_additional_imports = re.compile(
for match in re.finditer(re_additional_imports, contents):
for class_name in'class_names').split(','):
def ParseJavaPSignature(signature_line):
prefix = 'Signature: '
index = signature_line.find(prefix)
if index == -1:
prefix = 'descriptor: '
index = signature_line.index(prefix)
return '"%s"' % signature_line[index + len(prefix):]
def JavaToJni(param):
"""Converts a java param into a JNI signature type."""
pod_param_map = {
'int': 'I',
'boolean': 'Z',
'char': 'C',
'short': 'S',
'long': 'J',
'double': 'D',
'float': 'F',
'byte': 'B',
'void': 'V',
object_param_list = [
prefix = ''
# Array?
while param[-2:] == '[]':
prefix += '['
param = param[:-2]
# Generic?
if '<' in param:
param = param[:param.index('<')]
if param in pod_param_map:
return prefix + pod_param_map[param]
if '/' in param:
# Coming from javap, use the fully qualified param directly.
return prefix + 'L' + param + ';'
for qualified_name in (object_param_list +
[JniParams._fully_qualified_class] +
if (qualified_name.endswith('/' + param) or
qualified_name.endswith('$' + param.replace('.', '$')) or
qualified_name == 'L' + param):
return prefix + qualified_name + ';'
# Is it from an import? (e.g. referecing Class from import pkg.Class;
# note that referencing an inner class Inner from import pkg.Class.Inner
# is not supported).
for qualified_name in JniParams._imports:
if qualified_name.endswith('/' + param):
# Ensure it's not an inner class.
components = qualified_name.split('/')
if len(components) > 2 and components[-2][0].isupper():
raise SyntaxError('Inner class (%s) can not be imported '
'and used by JNI (%s). Please import the outer '
'class and use Outer.Inner instead.' %
(qualified_name, param))
return prefix + qualified_name + ';'
# Is it an inner class from an outer class import? (e.g. referencing
# Class.Inner from import pkg.Class).
if '.' in param:
components = param.split('.')
outer = '/'.join(components[:-1])
inner = components[-1]
for qualified_name in JniParams._imports:
if qualified_name.endswith('/' + outer):
return (prefix + qualified_name + '$' + inner + ';')
raise SyntaxError('Inner class (%s) can not be '
'used directly by JNI. Please import the outer '
'class, probably:\n'
'import %s.%s;' %
(param, JniParams._package.replace('/', '.'),
outer.replace('/', '.')))
# Type not found, falling back to same package as this class.
return (prefix + 'L' + JniParams._package + '/' + param + ';')
def _CheckImplicitImports(param):
# Ensure implicit imports, such as java.lang.*, are not being treated
# as being in the same package.
if not JniParams._implicit_imports:
# This file was generated from android.jar and lists
# all classes that are implicitly imported.
with file(os.path.join(os.path.dirname(sys.argv[0]),
'android_jar.classes'), 'r') as f:
JniParams._implicit_imports = f.readlines()
for implicit_import in JniParams._implicit_imports:
implicit_import = implicit_import.strip().replace('.class', '')
implicit_import = implicit_import.replace('/', '.')
if implicit_import.endswith('.' + param):
raise SyntaxError('Ambiguous class (%s) can not be used directly '
'by JNI.\nPlease import it, probably:\n\n'
'import %s;' %
(param, implicit_import))
def Signature(params, returns, wrap):
"""Returns the JNI signature for the given datatypes."""
items = ['(']
items += [JniParams.JavaToJni(param.datatype) for param in params]
items += [')']
items += [JniParams.JavaToJni(returns)]
if wrap:
return '\n' + '\n'.join(['"' + item + '"' for item in items])
return '"' + ''.join(items) + '"'
def Parse(params):
"""Parses the params into a list of Param objects."""
if not params:
return []
ret = []
for p in [p.strip() for p in params.split(',')]:
items = p.split(' ')
# Remove @Annotations from parameters.
while items[0].startswith('@'):
del items[0]
if 'final' in items:
param = Param(
name=(items[1] if len(items) > 1 else 'p%s' % len(ret)),
ret += [param]
return ret
def ExtractJNINamespace(contents):
re_jni_namespace = re.compile('.*?@JNINamespace\("(.*?)"\)')
m = re.findall(re_jni_namespace, contents)
if not m:
return ''
return m[0]
def ExtractFullyQualifiedJavaClassName(java_file_name, contents):
re_package = re.compile('.*?package (.*?);')
matches = re.findall(re_package, contents)
if not matches:
raise SyntaxError('Unable to find "package" line in %s' % java_file_name)
return (matches[0].replace('.', '/') + '/' +
def ExtractNatives(contents, ptr_type):
"""Returns a list of dict containing information about a native method."""
contents = contents.replace('\n', '')
natives = []
re_native = re.compile(r'(@NativeClassQualifiedName'
'(?P<qualifiers>\w+\s\w+|\w+|\s+)\s*native '
'(?P<return_type>\S*) '
for match in re.finditer(re_native, contents):
native = NativeMethod(
static='static' in'qualifiers'),'java_class_name'),'native_class_name'),'return_type'),'name').replace('native', ''),
natives += [native]
return natives
def IsMainDexJavaClass(contents):
"""Returns "true" if the class is annotated with "@MainDex", "false" if not.
JNI registration doesn't always need to be completed for non-browser processes
since most Java code is only used by the browser process. Classes that are
needed by non-browser processes must explicitly be annotated with @MainDex
to force JNI registration.
re_maindex = re.compile(r'@MainDex[\s\S]*class\s+\w+\s*{')
found =, contents)
return 'true' if found else 'false'
def GetStaticCastForReturnType(return_type):
type_map = { 'String' : 'jstring',
'java/lang/String' : 'jstring',
'Throwable': 'jthrowable',
'java/lang/Throwable': 'jthrowable',
'boolean[]': 'jbooleanArray',
'byte[]': 'jbyteArray',
'char[]': 'jcharArray',
'short[]': 'jshortArray',
'int[]': 'jintArray',
'long[]': 'jlongArray',
'float[]': 'jfloatArray',
'double[]': 'jdoubleArray' }
ret = type_map.get(return_type, None)
if ret:
return ret
if return_type.endswith('[]'):
return 'jobjectArray'
return None
def GetEnvCall(is_constructor, is_static, return_type):
"""Maps the types availabe via env->Call__Method."""
if is_constructor:
return 'NewObject'
env_call_map = {'boolean': 'Boolean',
'byte': 'Byte',
'char': 'Char',
'short': 'Short',
'int': 'Int',
'long': 'Long',
'float': 'Float',
'void': 'Void',
'double': 'Double',
'Object': 'Object',
call = env_call_map.get(return_type, 'Object')
if is_static:
call = 'Static' + call
return 'Call' + call + 'Method'
def GetMangledParam(datatype):
"""Returns a mangled identifier for the datatype."""
if len(datatype) <= 2:
return datatype.replace('[', 'A')
ret = ''
for i in range(1, len(datatype)):
c = datatype[i]
if c == '[':
ret += 'A'
elif c.isupper() or datatype[i - 1] in ['/', 'L']:
ret += c.upper()
return ret
def GetMangledMethodName(name, params, return_type):
"""Returns a mangled method name for the given signature.
The returned name can be used as a C identifier and will be unique for all
valid overloads of the same method.
name: string.
params: list of Param.
return_type: string.
A mangled name.
mangled_items = []
for datatype in [return_type] + [x.datatype for x in params]:
mangled_items += [GetMangledParam(JniParams.JavaToJni(datatype))]
mangled_name = name + '_'.join(mangled_items)
assert re.match(r'[0-9a-zA-Z_]+', mangled_name)
return mangled_name
def MangleCalledByNatives(called_by_natives):
"""Mangles all the overloads from the call_by_natives list."""
method_counts = collections.defaultdict(
lambda: collections.defaultdict(lambda: 0))
for called_by_native in called_by_natives:
java_class_name = called_by_native.java_class_name
name =
method_counts[java_class_name][name] += 1
for called_by_native in called_by_natives:
java_class_name = called_by_native.java_class_name
method_name =
method_id_var_name = method_name
if method_counts[java_class_name][method_name] > 1:
method_id_var_name = GetMangledMethodName(method_name,
called_by_native.method_id_var_name = method_id_var_name
return called_by_natives
# Regex to match the JNI types that should be wrapped in a JavaRef.
RE_SCOPED_JNI_TYPES = re.compile('jobject|jclass|jstring|jthrowable|.*Array')
# Regex to match a string like "@CalledByNative public void foo(int bar)".
RE_CALLED_BY_NATIVE = re.compile(
'\s+(?P<prefix>[\w ]*?)'
'(:?\s*@\w+)?' # Ignore annotations in return types.
# Removes empty lines that are indented (i.e. start with 2x spaces).
def RemoveIndentedEmptyLines(string):
return re.sub('^(?: {2})+$\n', '', string, flags=re.MULTILINE)
def ExtractCalledByNatives(contents):
"""Parses all methods annotated with @CalledByNative.
contents: the contents of the java file.
A list of dict with information about the annotated methods.
TODO(bulach): return a CalledByNative object.
ParseError: if unable to parse.
called_by_natives = []
for match in re.finditer(RE_CALLED_BY_NATIVE, contents):
called_by_natives += [CalledByNative(
unchecked='Unchecked' in'Unchecked'),
static='static' in'prefix'),'annotation') or '','return_type'),'name'),
# Check for any @CalledByNative occurrences that weren't matched.
unmatched_lines = re.sub(RE_CALLED_BY_NATIVE, '', contents).split('\n')
for line1, line2 in zip(unmatched_lines, unmatched_lines[1:]):
if '@CalledByNative' in line1:
raise ParseError('could not parse @CalledByNative method signature',
line1, line2)
return MangleCalledByNatives(called_by_natives)
class JNIFromJavaP(object):
"""Uses 'javap' to parse a .class file and generate the JNI header file."""
def __init__(self, contents, options):
self.contents = contents
self.namespace = options.namespace
for line in contents:
class_name = re.match(
'.*?(public).*?(class|interface) (?P<class_name>\S+?)( |\Z)',
if class_name:
self.fully_qualified_class ='class_name')
self.fully_qualified_class = self.fully_qualified_class.replace('.', '/')
# Java 7's javap includes type parameters in output, like HashSet<T>. Strip
# away the <...> and use the raw class name that Java 6 would've given us.
self.fully_qualified_class = self.fully_qualified_class.split('<', 1)[0]
self.java_class_name = self.fully_qualified_class.split('/')[-1]
if not self.namespace:
self.namespace = 'JNI_' + self.java_class_name
re_method = re.compile('(?P<prefix>.*?)(?P<return_type>\S+?) (?P<name>\w+?)'
self.called_by_natives = []
for lineno, content in enumerate(contents[2:], 2):
match = re.match(re_method, content)
if not match:
self.called_by_natives += [CalledByNative(
static='static' in'prefix'),
java_class_name='','return_type').replace('.', '/'),'name'),
params=JniParams.Parse('params').replace('.', '/')),
signature=JniParams.ParseJavaPSignature(contents[lineno + 1]))]
re_constructor = re.compile('(.*?)public ' +
self.fully_qualified_class.replace('/', '.') +
for lineno, content in enumerate(contents[2:], 2):
match = re.match(re_constructor, content)
if not match:
self.called_by_natives += [CalledByNative(
params=JniParams.Parse('params').replace('.', '/')),
signature=JniParams.ParseJavaPSignature(contents[lineno + 1]),
self.called_by_natives = MangleCalledByNatives(self.called_by_natives)
self.constant_fields = []
re_constant_field = re.compile('.*?public static final int (?P<name>.*?);')
re_constant_field_value = re.compile(
'.*?Constant(Value| value): int (?P<value>(-*[0-9]+)?)')
for lineno, content in enumerate(contents[2:], 2):
match = re.match(re_constant_field, content)
if not match:
value = re.match(re_constant_field_value, contents[lineno + 2])
if not value:
value = re.match(re_constant_field_value, contents[lineno + 3])
if value:
self.inl_header_file_generator = InlHeaderFileGenerator(
self.namespace, self.fully_qualified_class, [], self.called_by_natives,
self.constant_fields, options)
def GetContent(self):
return self.inl_header_file_generator.GetContent()
def CreateFromClass(class_file, options):
class_name = os.path.splitext(os.path.basename(class_file))[0]
p = subprocess.Popen(args=[options.javap, '-c', '-verbose',
'-s', class_name],
stdout, _ = p.communicate()
jni_from_javap = JNIFromJavaP(stdout.split('\n'), options)
return jni_from_javap
class JNIFromJavaSource(object):
"""Uses the given java source file to generate the JNI header file."""
# Match single line comments, multiline comments, character literals, and
# double-quoted strings.
_comment_remover_regex = re.compile(
def __init__(self, contents, fully_qualified_class, options):
contents = self._RemoveComments(contents)
jni_namespace = ExtractJNINamespace(contents) or options.namespace
natives = ExtractNatives(contents, options.ptr_type)
called_by_natives = ExtractCalledByNatives(contents)
maindex = IsMainDexJavaClass(contents)
if len(natives) == 0 and len(called_by_natives) == 0:
raise SyntaxError('Unable to find any JNI methods for %s.' %
inl_header_file_generator = InlHeaderFileGenerator(
jni_namespace, fully_qualified_class, natives, called_by_natives, [],
options, maindex)
self.content = inl_header_file_generator.GetContent()
def _RemoveComments(cls, contents):
# We need to support both inline and block comments, and we need to handle
# strings that contain '//' or '/*'.
# TODO(bulach): This is a bit hacky. It would be cleaner to use a real Java
# parser. Maybe we could ditch JNIFromJavaSource and just always use
# JNIFromJavaP; or maybe we could rewrite this script in Java and use APT.
def replacer(match):
# Replace matches that are comments with nothing; return literals/strings
# unchanged.
s =
if s.startswith('/'):
return ''
return s
return cls._comment_remover_regex.sub(replacer, contents)
def GetContent(self):
return self.content
def CreateFromFile(java_file_name, options):
contents = file(java_file_name).read()
fully_qualified_class = ExtractFullyQualifiedJavaClassName(java_file_name,
return JNIFromJavaSource(contents, fully_qualified_class, options)
class InlHeaderFileGenerator(object):
"""Generates an inline header file for JNI integration."""
def __init__(self, namespace, fully_qualified_class, natives,
called_by_natives, constant_fields, options, maindex='false'):
self.namespace = namespace
self.fully_qualified_class = fully_qualified_class
self.class_name = self.fully_qualified_class.split('/')[-1]
self.natives = natives
self.called_by_natives = called_by_natives
self.header_guard = fully_qualified_class.replace('/', '_') + '_JNI'
self.constant_fields = constant_fields
self.maindex = maindex
self.options = options
def GetContent(self):
"""Returns the content of the JNI binding file."""
template = Template("""\
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This file is autogenerated by
// For
#ifndef ${HEADER_GUARD}
#define ${HEADER_GUARD}
#include <jni.h>
#include "base/android/jni_int_wrapper.h"
// Step 1: forward declarations.
namespace {
} // namespace
// Step 2: method stubs.
// Step 3: RegisterNatives.
#endif // ${HEADER_GUARD}
values = {
'SCRIPT_NAME': self.options.script_name,
'FULLY_QUALIFIED_CLASS': self.fully_qualified_class,
'CLASS_PATH_DEFINITIONS': self.GetClassPathDefinitionsString(),
'CONSTANT_FIELDS': self.GetConstantFieldsString(),
'METHOD_STUBS': self.GetMethodStubsString(),
'OPEN_NAMESPACE': self.GetOpenNamespaceString(),
'JNI_NATIVE_METHODS': self.GetJNINativeMethodsString(),
'REGISTER_NATIVES': self.GetRegisterNativesString(),
'CLOSE_NAMESPACE': self.GetCloseNamespaceString(),
'HEADER_GUARD': self.header_guard,
'INCLUDES': self.GetIncludesString(),
assert ((values['JNI_NATIVE_METHODS'] == '') ==
(values['REGISTER_NATIVES'] == ''))
return WrapOutput(template.substitute(values))
def GetClassPathDefinitionsString(self):
ret = []
ret += [self.GetClassPathDefinitions()]
return '\n'.join(ret)
def GetConstantFieldsString(self):
if not self.constant_fields:
return ''
ret = ['enum Java_%s_constant_fields {' % self.class_name]
for c in self.constant_fields:
ret += [' %s = %s,' % (, c.value)]
ret += ['};']
return '\n'.join(ret)
def GetMethodStubsString(self):
"""Returns the code corresponding to method stubs."""
ret = []
for native in self.natives:
ret += [self.GetNativeStub(native)]
ret += self.GetLazyCalledByNativeMethodStubs()
return '\n'.join(ret)
def GetLazyCalledByNativeMethodStubs(self):
return [self.GetLazyCalledByNativeMethodStub(called_by_native)
for called_by_native in self.called_by_natives]
def GetIncludesString(self):
if not self.options.includes:
return ''
includes = self.options.includes.split(',')
return '\n'.join('#include "%s"' % x for x in includes)
def GetKMethodsString(self, clazz):
ret = []
for native in self.natives:
if (native.java_class_name == clazz or
(not native.java_class_name and clazz == self.class_name)):
ret += [self.GetKMethodArrayEntry(native)]
return '\n'.join(ret)
def SubstituteNativeMethods(self, template):
"""Substitutes JAVA_CLASS and KMETHODS in the provided template."""
ret = []
all_classes = self.GetUniqueClasses(self.natives)
all_classes[self.class_name] = self.fully_qualified_class
for clazz in all_classes:
kmethods = self.GetKMethodsString(clazz)
if kmethods:
values = {'JAVA_CLASS': clazz,
'KMETHODS': kmethods}
ret += [template.substitute(values)]
if not ret: return ''
return '\n' + '\n'.join(ret)
def GetJNINativeMethodsString(self):
"""Returns the implementation of the array of native methods."""
if not self.options.native_exports_optional:
return ''
template = Template("""\
static const JNINativeMethod kMethods${JAVA_CLASS}[] = {
return self.SubstituteNativeMethods(template)
def GetRegisterNativesString(self):
"""Returns the code for RegisterNatives."""
natives = self.GetRegisterNativesImplString()
if not natives:
return ''
template = Template("""\
return true;
signature = 'static bool RegisterNativesImpl(JNIEnv* env)'
early_exit = ''
if self.options.native_exports_optional:
early_exit = """\
if (jni_generator::ShouldSkipJniRegistration(%s))
return true;
""" % self.maindex
values = {'REGISTER_NATIVES_SIGNATURE': signature,
'EARLY_EXIT': early_exit,
'NATIVES': natives,
return template.substitute(values)
def GetRegisterNativesImplString(self):
"""Returns the shared implementation for RegisterNatives."""
if not self.options.native_exports_optional:
return ''
template = Template("""\
const int kMethods${JAVA_CLASS}Size = arraysize(kMethods${JAVA_CLASS});
if (env->RegisterNatives(${JAVA_CLASS}_clazz(env),
kMethods${JAVA_CLASS}Size) < 0) {
env, ${JAVA_CLASS}_clazz(env), __FILE__);
return false;
return self.SubstituteNativeMethods(template)
def GetOpenNamespaceString(self):
if self.namespace:
all_namespaces = ['namespace %s {' % ns
for ns in self.namespace.split('::')]
return '\n'.join(all_namespaces)
return ''
def GetCloseNamespaceString(self):
if self.namespace:
all_namespaces = ['} // namespace %s' % ns
for ns in self.namespace.split('::')]
return '\n'.join(all_namespaces) + '\n'
return ''
def GetJNIFirstParamType(self, native):
if native.type == 'method':
return 'jobject'
elif native.type == 'function':
if native.static:
return 'jclass'
return 'jobject'
def GetJNIFirstParam(self, native, for_declaration):
c_type = self.GetJNIFirstParamType(native)
if for_declaration:
c_type = WrapCTypeForDeclaration(c_type)
return [c_type + ' jcaller']
def GetParamsInDeclaration(self, native):
"""Returns the params for the forward declaration.
native: the native dictionary describing the method.
A string containing the params.
return ',\n '.join(self.GetJNIFirstParam(native, True) +
[JavaDataTypeToCForDeclaration(param.datatype) + ' ' +
for param in native.params])
def GetParamsInStub(self, native):
"""Returns the params for the stub declaration.
native: the native dictionary describing the method.
A string containing the params.
return ',\n '.join(self.GetJNIFirstParam(native, False) +
[JavaDataTypeToC(param.datatype) + ' ' +
for param in native.params])
def GetCalledByNativeParamsInDeclaration(self, called_by_native):
return ',\n '.join([
JavaDataTypeToCForCalledByNativeParam(param.datatype) + ' ' +
for param in called_by_native.params])
def GetStubName(self, native):
"""Return the name of the stub function for this native method.
native: the native dictionary describing the method.
A string with the stub function name (used by the JVM).
template = Template("Java_${JAVA_NAME}_native${NAME}")
java_name = self.fully_qualified_class.replace('_', '_1').replace('/', '_')
if native.java_class_name:
java_name += '_00024' + native.java_class_name
values = {'NAME':,
'JAVA_NAME': java_name}
return template.substitute(values)
def GetJavaParamRefForCall(self, c_type, name):
return Template(
'base::android::JavaParamRef<${TYPE}>(env, ${NAME})').substitute({
'TYPE': c_type,
'NAME': name,
def GetJNIFirstParamForCall(self, native):
c_type = self.GetJNIFirstParamType(native)
return [self.GetJavaParamRefForCall(c_type, 'jcaller')]
def GetNativeStub(self, native):
is_method = native.type == 'method'
if is_method:
params = native.params[1:]
params = native.params
params_in_call = ['env'] + self.GetJNIFirstParamForCall(native)
for p in params:
c_type = JavaDataTypeToC(p.datatype)
if re.match(RE_SCOPED_JNI_TYPES, c_type):
params_in_call = ', '.join(params_in_call)
return_type = return_declaration = JavaDataTypeToC(native.return_type)
post_call = ''
if re.match(RE_SCOPED_JNI_TYPES, return_type):
post_call = '.Release()'
return_declaration = ('base::android::ScopedJavaLocalRef<' + return_type +
profiling_entered_native = ''
if self.options.enable_profiling:
profiling_entered_native = 'JNI_LINK_SAVED_FRAME_POINTER;'
values = {
'RETURN': return_type,
'RETURN_DECLARATION': return_declaration,
'PARAMS': self.GetParamsInDeclaration(native),
'PARAMS_IN_STUB': self.GetParamsInStub(native),
'PARAMS_IN_CALL': params_in_call,
'POST_CALL': post_call,
'STUB_NAME': self.GetStubName(native),
'PROFILING_ENTERED_NATIVE': profiling_entered_native,
if is_method:
optional_error_return = JavaReturnValueToC(native.return_type)
if optional_error_return:
optional_error_return = ', ' + optional_error_return
'OPTIONAL_ERROR_RETURN': optional_error_return,
'PARAM0_NAME': native.params[0].name,
'P0_TYPE': native.p0_type,
template = Template("""\
${P0_TYPE}* native = reinterpret_cast<${P0_TYPE}*>(${PARAM0_NAME});
CHECK_NATIVE_PTR(env, jcaller, native, "${NAME}"${OPTIONAL_ERROR_RETURN});
return native->${NAME}(${PARAMS_IN_CALL})${POST_CALL};
template = Template("""
return RemoveIndentedEmptyLines(template.substitute(values))
def GetArgument(self, param):
if param.datatype == 'int':
return 'as_jint(' + + ')'
elif re.match(RE_SCOPED_JNI_TYPES, JavaDataTypeToC(param.datatype)):
return + '.obj()'
def GetArgumentsInCall(self, params):
"""Return a string of arguments to call from native into Java"""
return [self.GetArgument(p) for p in params]
def GetCalledByNativeValues(self, called_by_native):
"""Fills in necessary values for the CalledByNative methods."""
java_class = called_by_native.java_class_name or self.class_name
if called_by_native.static or called_by_native.is_constructor:
first_param_in_declaration = ''
first_param_in_call = ('%s_clazz(env)' % java_class)
first_param_in_declaration = (
', const base::android::JavaRefOrBare<jobject>& obj')
first_param_in_call = 'obj.obj()'
params_in_declaration = self.GetCalledByNativeParamsInDeclaration(
if params_in_declaration:
params_in_declaration = ', ' + params_in_declaration
params_in_call = ', '.join(self.GetArgumentsInCall(called_by_native.params))
if params_in_call:
params_in_call = ', ' + params_in_call
pre_call = ''
post_call = ''
if called_by_native.static_cast:
pre_call = 'static_cast<%s>(' % called_by_native.static_cast
post_call = ')'
check_exception = ''
if not called_by_native.unchecked:
check_exception = 'jni_generator::CheckException(env);'
return_type = JavaDataTypeToC(called_by_native.return_type)
optional_error_return = JavaReturnValueToC(called_by_native.return_type)
if optional_error_return:
optional_error_return = ', ' + optional_error_return
return_declaration = ''
return_clause = ''
if return_type != 'void':
pre_call = ' ' + pre_call
return_declaration = return_type + ' ret ='
if re.match(RE_SCOPED_JNI_TYPES, return_type):
return_type = 'base::android::ScopedJavaLocalRef<' + return_type + '>'
return_clause = 'return ' + return_type + '(env, ret);'
return_clause = 'return ret;'
profiling_leaving_native = ''
if self.options.enable_profiling:
profiling_leaving_native = 'JNI_SAVE_FRAME_POINTER;'
return {
'JAVA_CLASS': java_class,
'RETURN_TYPE': return_type,
'OPTIONAL_ERROR_RETURN': optional_error_return,
'RETURN_DECLARATION': return_declaration,
'RETURN_CLAUSE': return_clause,
'FIRST_PARAM_IN_DECLARATION': first_param_in_declaration,
'PARAMS_IN_DECLARATION': params_in_declaration,
'PRE_CALL': pre_call,
'POST_CALL': post_call,
'ENV_CALL': called_by_native.env_call,
'FIRST_PARAM_IN_CALL': first_param_in_call,
'PARAMS_IN_CALL': params_in_call,
'METHOD_ID_VAR_NAME': called_by_native.method_id_var_name,
'CHECK_EXCEPTION': check_exception,
'GET_METHOD_ID_IMPL': self.GetMethodIDImpl(called_by_native),
'PROFILING_LEAVING_NATIVE': profiling_leaving_native,
def GetLazyCalledByNativeMethodStub(self, called_by_native):
"""Returns a string."""
function_signature_template = Template("""\
function_header_template = Template("""\
function_header_with_unused_template = Template("""\
${FUNCTION_SIGNATURE} __attribute__ ((unused));
template = Template("""
static base::subtle::AtomicWord g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} = 0;
jmethodID method_id =
values = self.GetCalledByNativeValues(called_by_native)
if called_by_native.system_class:
values['FUNCTION_HEADER'] = (
values['FUNCTION_HEADER'] = function_header_template.substitute(values)
return RemoveIndentedEmptyLines(template.substitute(values))
def GetKMethodArrayEntry(self, native):
template = Template(' { "native${NAME}", ${JNI_SIGNATURE}, ' +
'reinterpret_cast<void*>(${STUB_NAME}) },')
values = {'NAME':,
'JNI_SIGNATURE': JniParams.Signature(native.params,
'STUB_NAME': self.GetStubName(native)}
return template.substitute(values)
def GetUniqueClasses(self, origin):
ret = {self.class_name: self.fully_qualified_class}
for entry in origin:
class_name = self.class_name
jni_class_path = self.fully_qualified_class
if entry.java_class_name:
class_name = entry.java_class_name
jni_class_path = self.fully_qualified_class + '$' + class_name
ret[class_name] = jni_class_path
return ret
def GetClassPathDefinitions(self):
"""Returns the ClassPath constants."""
ret = []
template = Template("""\
const char k${JAVA_CLASS}ClassPath[] = "${JNI_CLASS_PATH}";""")
all_classes = self.GetUniqueClasses(self.called_by_natives)
if self.options.native_exports_optional:
for clazz in all_classes:
values = {
'JAVA_CLASS': clazz,
'JNI_CLASS_PATH': all_classes[clazz],
ret += [template.substitute(values)]
ret += ''
template = Template("""\
// Leaking this jclass as we cannot use LazyInstance from some threads.
base::subtle::AtomicWord g_${JAVA_CLASS}_clazz __attribute__((unused)) = 0;
#define ${JAVA_CLASS}_clazz(env) \
base::android::LazyGetClass(env, k${JAVA_CLASS}ClassPath, \
for clazz in all_classes:
values = {
'JAVA_CLASS': clazz,
ret += [template.substitute(values)]
return '\n'.join(ret)
def GetMethodIDImpl(self, called_by_native):
"""Returns the implementation of GetMethodID."""
template = Template("""\
env, ${JAVA_CLASS}_clazz(env),
jni_name =
jni_return_type = called_by_native.return_type
if called_by_native.is_constructor:
jni_name = '<init>'
jni_return_type = 'void'
if called_by_native.signature:
signature = called_by_native.signature
signature = JniParams.Signature(called_by_native.params,
values = {
'JAVA_CLASS': called_by_native.java_class_name or self.class_name,
'JNI_NAME': jni_name,
'METHOD_ID_VAR_NAME': called_by_native.method_id_var_name,
'STATIC': 'STATIC' if called_by_native.static else 'INSTANCE',
'JNI_SIGNATURE': signature,
return template.substitute(values)
def WrapOutput(output):
ret = []
for line in output.splitlines():
# Do not wrap lines under 80 characters or preprocessor directives.
if len(line) < 80 or line.lstrip()[:1] == '#':
stripped = line.rstrip()
if len(ret) == 0 or len(ret[-1]) or len(stripped):
first_line_indent = ' ' * (len(line) - len(line.lstrip()))
subsequent_indent = first_line_indent + ' ' * 4
if line.startswith('//'):
subsequent_indent = '//' + subsequent_indent
wrapper = textwrap.TextWrapper(width=80,
ret += [wrapped.rstrip() for wrapped in wrapper.wrap(line)]
ret += ['']
return '\n'.join(ret)
def ExtractJarInputFile(jar_file, input_file, out_dir):
"""Extracts input file from jar and returns the filename.
The input file is extracted to the same directory that the generated jni
headers will be placed in. This is passed as an argument to script.
jar_file: the jar file containing the input files to extract.
input_files: the list of files to extract from the jar file.
out_dir: the name of the directories to extract to.
the name of extracted input file.
jar_file = zipfile.ZipFile(jar_file)
out_dir = os.path.join(out_dir, os.path.dirname(input_file))
except OSError as e:
if e.errno != errno.EEXIST:
extracted_file_name = os.path.join(out_dir, os.path.basename(input_file))
with open(extracted_file_name, 'w') as outfile:
return extracted_file_name
def GenerateJNIHeader(input_file, output_file, options):
if os.path.splitext(input_file)[1] == '.class':
jni_from_javap = JNIFromJavaP.CreateFromClass(input_file, options)
content = jni_from_javap.GetContent()
jni_from_java_source = JNIFromJavaSource.CreateFromFile(
input_file, options)
content = jni_from_java_source.GetContent()
except ParseError, e:
print e
if output_file:
if not os.path.exists(os.path.dirname(os.path.abspath(output_file))):
if options.optimize_generation and os.path.exists(output_file):
with file(output_file, 'r') as f:
existing_content =
if existing_content == content:
with file(output_file, 'w') as f:
print content
def GetScriptName():
script_components = os.path.abspath(sys.argv[0]).split(os.path.sep)
base_index = 0
for idx, value in enumerate(script_components):
if value == 'base' or value == 'third_party':
base_index = idx
return os.sep.join(script_components[base_index:])
def main(argv):
usage = """usage: %prog [OPTIONS]
This script will parse the given java source code extracting the native
declarations and print the header file to stdout (or a file).
See for more details.
option_parser = optparse.OptionParser(usage=usage)
option_parser.add_option('-j', '--jar_file', dest='jar_file',
help='Extract the list of input files from'
' a specified jar file.'
' Uses javap to extract the methods from a'
' pre-compiled class. --input should point'
' to pre-compiled Java .class files.')
option_parser.add_option('-n', dest='namespace',
help='Uses as a namespace in the generated header '
'instead of the javap class name, or when there is '
'no JNINamespace annotation in the java source.')
help='Single input file name. The output file name '
'will be derived from it. Must be used with '
help='The output directory. Must be used with '
option_parser.add_option('--optimize_generation', type="int",
default=0, help='Whether we should optimize JNI '
'generation by not regenerating files if they have '
'not changed.')
option_parser.add_option('--script_name', default=GetScriptName(),
help='The name of this script in the generated '
help='The comma-separated list of header files to '
'include in the generated header.')
option_parser.add_option('--ptr_type', default='int',
type='choice', choices=['int', 'long'],
help='The type used to represent native pointers in '
'Java code. For 32-bit, use int; '
'for 64-bit, use long.')
option_parser.add_option('--cpp', default='cpp',
help='The path to cpp command.')
option_parser.add_option('--javap', default='javap',
help='The path to javap command.')
option_parser.add_option('--native_exports_optional', action='store_true',
help='Support both explicit and native method'
option_parser.add_option('--enable_profiling', action='store_true',
help='Add additional profiling instrumentation.')
options, args = option_parser.parse_args(argv)
if options.jar_file:
input_file = ExtractJarInputFile(options.jar_file, options.input_file,
elif options.input_file:
input_file = options.input_file
print '\nError: Must specify --jar_file or --input_file.'
return 1
output_file = None
if options.output_dir:
root_name = os.path.splitext(os.path.basename(input_file))[0]
output_file = os.path.join(options.output_dir, root_name) + '_jni.h'
GenerateJNIHeader(input_file, output_file, options)
if options.depfile:
build_utils.WriteDepfile(options.depfile, output_file)
if __name__ == '__main__':