Remove unneeded JNI registrations.

base/android/jni_generator/jni_generator.py

Index: base/android/jni_generator/jni_generator.py
diff --git a/base/android/jni_generator/jni_generator.py b/base/android/jni_generator/jni_generator.py
index 27335834953a3e006647d27d98b301deb5b1fbf2..23b4b76fe3c7bde515f64008b0122cb4a8872d52 100755
--- a/base/android/jni_generator/jni_generator.py
+++ b/base/android/jni_generator/jni_generator.py
@@ -673,18 +673,18 @@ $METHOD_ID_DEFINITIONS
 }  // namespace
 
 $OPEN_NAMESPACE
+extern "C"{
 $FORWARD_DECLARATIONS
 
 $CONSTANT_FIELDS
 
 // Step 2: method stubs.
 $METHOD_STUBS
+};
 
 // Step 3: RegisterNatives.
-$JNI_NATIVE_METHODS
 $REGISTER_NATIVES
 $CLOSE_NAMESPACE
-$JNI_REGISTER_NATIVES
 #endif  // ${HEADER_GUARD}
 """)
     values = {
@@ -696,12 +696,10 @@ $JNI_REGISTER_NATIVES
         '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(),
-        'JNI_REGISTER_NATIVES': self.GetJNIRegisterNativesString()
     }
     return WrapOutput(template.substitute(values))
 
@@ -780,29 +778,6 @@ jmethodID g_${JAVA_CLASS}_${METHOD_ID_VAR_NAME} = NULL;""")
         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."""
-    template = Template("""\
-static const JNINativeMethod kMethods${JAVA_CLASS}[] = {
-${KMETHODS}
-};
-""")
-    return self.SubstituteNativeMethods(template)
-
   def GetRegisterCalledByNativesImplString(self):
     """Returns the code for registering the called by native methods."""
     if not self.options.eager_called_by_natives:
@@ -825,10 +800,12 @@ ${KMETHODS}
 
   def GetRegisterNativesString(self):
     """Returns the code for RegisterNatives."""
+
+    if not self.called_by_natives and not self.options.eager_called_by_natives :
+        return ''
     template = Template("""\
 ${REGISTER_NATIVES_SIGNATURE} {
 ${CLASSES}
-${NATIVES}
 ${CALLED_BY_NATIVES}
   return true;
 }
@@ -839,30 +816,13 @@ ${CALLED_BY_NATIVES}
     else:
       signature += ')'
 
-    natives = self.GetRegisterNativesImplString()
     called_by_natives = self.GetRegisterCalledByNativesImplString()
     values = {'REGISTER_NATIVES_SIGNATURE': signature,
               'CLASSES': self.GetFindClasses(),
-              'NATIVES': natives,
               'CALLED_BY_NATIVES': called_by_natives,
              }
     return template.substitute(values)
 
-  def GetRegisterNativesImplString(self):
-    """Returns the shared implementation for RegisterNatives."""
-    template = Template("""\
-  const int kMethods${JAVA_CLASS}Size = arraysize(kMethods${JAVA_CLASS});
-
-  if (env->RegisterNatives(g_${JAVA_CLASS}_clazz,
-                           kMethods${JAVA_CLASS},
-                           kMethods${JAVA_CLASS}Size) < 0) {
-    jni_generator::HandleRegistrationError(
-        env, g_${JAVA_CLASS}_clazz, __FILE__);
-    return false;
-  }
-""")
-    return self.SubstituteNativeMethods(template)
-
   def GetJNIRegisterNativesString(self):
     """Returns the implementation for the JNI registration of native methods."""
     if not self.init_native:
@@ -881,7 +841,6 @@ Java_${FULLY_QUALIFIED_CLASS}_${INIT_NATIVE_NAME}(JNIEnv* env, jclass clazz) {
     values = {'FULLY_QUALIFIED_CLASS': fully_qualified_class,
               'INIT_NATIVE_NAME': 'native' + self.init_native.name,
               'NAMESPACE': namespace,
-              'REGISTER_NATIVES_IMPL': self.GetRegisterNativesImplString()
              }
     return template.substitute(values)
 
@@ -933,9 +892,16 @@ Java_${FULLY_QUALIFIED_CLASS}_${INIT_NATIVE_NAME}(JNIEnv* env, jclass clazz) {
   def GetForwardDeclaration(self, native):
     template = Template("""
 static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS});
+__attribute__((alias("${NAME}"), visibility("default"))) ${RETURN}
+    Java_${JAVA_NAME}_native${NAME}(JNIEnv* env, ${PARAMS});
 """)
+    java_name = JniParams.RemapClassName(self.fully_qualified_class).replace('_', '_1').replace('/', '_')
+    if native.java_class_name:
+      java_name += "_00024" + native.java_class_name
+
     values = {'RETURN': JavaDataTypeToC(native.return_type),
               'NAME': native.name,
+              'JAVA_NAME': java_name,
               'PARAMS': self.GetParamsInDeclaration(native)}
     return template.substitute(values)
 
@@ -947,6 +913,9 @@ static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS_IN_DECLARATION}) {
   CHECK_NATIVE_PTR(env, jcaller, native, "${NAME}"${OPTIONAL_ERROR_RETURN});
   return native->${NAME}(${PARAMS_IN_CALL})${POST_CALL};
 }
+__attribute__((alias("${NAME}"), visibility("default")))
+  ${RETURN} Java_${JAVA_NAME}_native${NAME}(JNIEnv* env,
+      ${PARAMS_IN_DECLARATION});
 """)
     params = []
     if not self.options.pure_native_methods:
@@ -960,9 +929,13 @@ static ${RETURN} ${NAME}(JNIEnv* env, ${PARAMS_IN_DECLARATION}) {
     post_call = ''
     if re.match(RE_SCOPED_JNI_RETURN_TYPES, return_type):
       post_call = '.Release()'
+    java_name = JniParams.RemapClassName(self.fully_qualified_class).replace('_', '_1').replace('/', '_')
+    if native.java_class_name:
+      java_name += "_00024" + native.java_class_name
     values = {
         'RETURN': return_type,
         'OPTIONAL_ERROR_RETURN': optional_error_return,
+        'JAVA_NAME': java_name,
         'NAME': native.name,
         'PARAMS_IN_DECLARATION': self.GetParamsInDeclaration(native),
         'PARAM0_NAME': native.params[0].name,
@@ -1098,12 +1071,11 @@ ${FUNCTION_HEADER}
   def GetClassPathDefinitions(self):
     """Returns the ClassPath constants."""
     ret = []
+    if not self.called_by_natives:
+      return ''
     template = Template("""\
 const char k${JAVA_CLASS}ClassPath[] = "${JNI_CLASS_PATH}";""")
-    native_classes = self.GetUniqueClasses(self.natives)
-    called_by_native_classes = self.GetUniqueClasses(self.called_by_natives)
-    all_classes = native_classes
-    all_classes.update(called_by_native_classes)
+    all_classes = self.GetUniqueClasses(self.called_by_natives)
     for clazz in all_classes:
       values = {
           'JAVA_CLASS': clazz,
@@ -1111,7 +1083,7 @@ const char k${JAVA_CLASS}ClassPath[] = "${JNI_CLASS_PATH}";""")
       }
       ret += [template.substitute(values)]
     ret += ''
-    for clazz in called_by_native_classes:
+    for clazz in all_classes:
       template = Template("""\
 // Leaking this jclass as we cannot use LazyInstance from some threads.
 jclass g_${JAVA_CLASS}_clazz = NULL;""")
@@ -1122,6 +1094,8 @@ jclass g_${JAVA_CLASS}_clazz = NULL;""")
     return '\n'.join(ret)
 
   def GetFindClasses(self):
+    if not self.called_by_natives:
+      return ''
     """Returns the imlementation of FindClass for all known classes."""
     if self.init_native:
       template = Template("""\