1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "art_method-inl.h"
18 #include "base/logging.h"
19 #include "entrypoints/entrypoint_utils.h"
20 #include "java_vm_ext.h"
21 #include "mirror/object-inl.h"
22 #include "scoped_thread_state_change-inl.h"
23 #include "thread.h"
24 
25 namespace art {
26 
27 // Used by the JNI dlsym stub to find the native method to invoke if none is registered.
28 #if defined(__arm__) || defined(__aarch64__)
artFindNativeMethod()29 extern "C" const void* artFindNativeMethod() {
30   Thread* self = Thread::Current();
31 #else
32 extern "C" const void* artFindNativeMethod(Thread* self) {
33   DCHECK_EQ(self, Thread::Current());
34 #endif
35   Locks::mutator_lock_->AssertNotHeld(self);  // We come here as Native.
36   ScopedObjectAccess soa(self);
37 
38   ArtMethod* method = self->GetCurrentMethod(nullptr);
39   DCHECK(method != nullptr);
40 
41   // Lookup symbol address for method, on failure we'll return null with an exception set,
42   // otherwise we return the address of the method we found.
43   void* native_code = soa.Vm()->FindCodeForNativeMethod(method);
44   if (native_code == nullptr) {
45     DCHECK(self->IsExceptionPending());
46     return nullptr;
47   } else {
48     // Register so that future calls don't come here
49     return method->RegisterNative(native_code, false);
50   }
51 }
52 
53 }  // namespace art
54