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      1 /*
      2  * Copyright (C) 2008 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 "java_lang_reflect_Constructor.h"
     18 
     19 #include "art_method-inl.h"
     20 #include "class_linker.h"
     21 #include "class_linker-inl.h"
     22 #include "jni_internal.h"
     23 #include "mirror/class-inl.h"
     24 #include "mirror/method.h"
     25 #include "mirror/object-inl.h"
     26 #include "reflection.h"
     27 #include "scoped_fast_native_object_access.h"
     28 #include "well_known_classes.h"
     29 
     30 namespace art {
     31 
     32 static jobject Constructor_getAnnotationNative(JNIEnv* env, jobject javaMethod,
     33                                                jclass annotationType) {
     34   ScopedFastNativeObjectAccess soa(env);
     35   StackHandleScope<1> hs(soa.Self());
     36   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
     37   if (method->IsProxyMethod()) {
     38     return nullptr;
     39   } else {
     40     Handle<mirror::Class> klass(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
     41     return soa.AddLocalReference<jobject>(
     42         method->GetDexFile()->GetAnnotationForMethod(method, klass));
     43   }
     44 }
     45 
     46 static jobjectArray Constructor_getDeclaredAnnotations(JNIEnv* env, jobject javaMethod) {
     47   ScopedFastNativeObjectAccess soa(env);
     48   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
     49   if (method->IsProxyMethod()) {
     50     mirror::Class* class_class = mirror::Class::GetJavaLangClass();
     51     mirror::Class* class_array_class =
     52         Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
     53     if (class_array_class == nullptr) {
     54       return nullptr;
     55     }
     56     mirror::ObjectArray<mirror::Class>* empty_array =
     57         mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
     58     return soa.AddLocalReference<jobjectArray>(empty_array);
     59   } else {
     60     return soa.AddLocalReference<jobjectArray>(
     61         method->GetDexFile()->GetAnnotationsForMethod(method));
     62   }
     63 }
     64 
     65 static jobjectArray Constructor_getExceptionTypes(JNIEnv* env, jobject javaMethod) {
     66   ScopedFastNativeObjectAccess soa(env);
     67   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod)
     68       ->GetInterfaceMethodIfProxy(sizeof(void*));
     69   mirror::ObjectArray<mirror::Class>* result_array =
     70       method->GetDexFile()->GetExceptionTypesForMethod(method);
     71   if (result_array == nullptr) {
     72     // Return an empty array instead of a null pointer.
     73     mirror::Class* class_class = mirror::Class::GetJavaLangClass();
     74     mirror::Class* class_array_class =
     75         Runtime::Current()->GetClassLinker()->FindArrayClass(soa.Self(), &class_class);
     76     if (class_array_class == nullptr) {
     77       return nullptr;
     78     }
     79     mirror::ObjectArray<mirror::Class>* empty_array =
     80         mirror::ObjectArray<mirror::Class>::Alloc(soa.Self(), class_array_class, 0);
     81     return soa.AddLocalReference<jobjectArray>(empty_array);
     82   } else {
     83     return soa.AddLocalReference<jobjectArray>(result_array);
     84   }
     85 }
     86 
     87 static jobjectArray Constructor_getParameterAnnotationsNative(JNIEnv* env, jobject javaMethod) {
     88   ScopedFastNativeObjectAccess soa(env);
     89   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
     90   if (method->IsProxyMethod()) {
     91     return nullptr;
     92   } else {
     93     return soa.AddLocalReference<jobjectArray>(
     94         method->GetDexFile()->GetParameterAnnotations(method));
     95   }
     96 }
     97 
     98 static jboolean Constructor_isAnnotationPresentNative(JNIEnv* env, jobject javaMethod,
     99                                                       jclass annotationType) {
    100   ScopedFastNativeObjectAccess soa(env);
    101   StackHandleScope<1> hs(soa.Self());
    102   ArtMethod* method = ArtMethod::FromReflectedMethod(soa, javaMethod);
    103   if (method->IsProxyMethod()) {
    104     // Proxies have no annotations.
    105     return false;
    106   }
    107   Handle<mirror::Class> klass(hs.NewHandle(soa.Decode<mirror::Class*>(annotationType)));
    108   return method->GetDexFile()->IsMethodAnnotationPresent(method, klass);
    109 }
    110 
    111 /*
    112  * We can also safely assume the constructor isn't associated
    113  * with an interface, array, or primitive class. If this is coming from
    114  * native, it is OK to avoid access checks since JNI does not enforce them.
    115  */
    116 static jobject Constructor_newInstance0(JNIEnv* env, jobject javaMethod, jobjectArray javaArgs) {
    117   ScopedFastNativeObjectAccess soa(env);
    118   mirror::Constructor* m = soa.Decode<mirror::Constructor*>(javaMethod);
    119   StackHandleScope<1> hs(soa.Self());
    120   Handle<mirror::Class> c(hs.NewHandle(m->GetDeclaringClass()));
    121   if (UNLIKELY(c->IsAbstract())) {
    122     soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;", "Can't instantiate %s %s",
    123                                    c->IsInterface() ? "interface" : "abstract class",
    124                                    PrettyDescriptor(c.Get()).c_str());
    125     return nullptr;
    126   }
    127   // Verify that we can access the class.
    128   if (!m->IsAccessible() && !c->IsPublic()) {
    129     // Go 2 frames back, this method is always called from newInstance0, which is called from
    130     // Constructor.newInstance(Object... args).
    131     auto* caller = GetCallingClass(soa.Self(), 2);
    132     // If caller is null, then we called from JNI, just avoid the check since JNI avoids most
    133     // access checks anyways. TODO: Investigate if this the correct behavior.
    134     if (caller != nullptr && !caller->CanAccess(c.Get())) {
    135       if (PrettyDescriptor(c.Get()) == "dalvik.system.DexPathList$Element") {
    136         // b/20699073.
    137         LOG(WARNING) << "The dalvik.system.DexPathList$Element constructor is not accessible by "
    138                         "default. This is a temporary workaround for backwards compatibility "
    139                         "with class-loader hacks. Please update your application.";
    140       } else {
    141         soa.Self()->ThrowNewExceptionF(
    142             "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
    143             PrettyClass(c.Get()).c_str(), PrettyClass(caller).c_str());
    144         return nullptr;
    145       }
    146     }
    147   }
    148   if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(soa.Self(), c, true, true)) {
    149     DCHECK(soa.Self()->IsExceptionPending());
    150     return nullptr;
    151   }
    152   bool movable = true;
    153   if (!kMovingClasses && c->IsClassClass()) {
    154     movable = false;
    155   }
    156 
    157   // String constructor is replaced by a StringFactory method in InvokeMethod.
    158   if (c->IsStringClass()) {
    159     return InvokeMethod(soa, javaMethod, nullptr, javaArgs, 2);
    160   }
    161 
    162   mirror::Object* receiver =
    163       movable ? c->AllocObject(soa.Self()) : c->AllocNonMovableObject(soa.Self());
    164   if (receiver == nullptr) {
    165     return nullptr;
    166   }
    167   jobject javaReceiver = soa.AddLocalReference<jobject>(receiver);
    168   InvokeMethod(soa, javaMethod, javaReceiver, javaArgs, 2);
    169   // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
    170   return javaReceiver;
    171 }
    172 
    173 static jobject Constructor_newInstanceFromSerialization(JNIEnv* env, jclass unused ATTRIBUTE_UNUSED,
    174                                                         jclass ctorClass, jclass allocClass) {
    175     jmethodID ctor = env->GetMethodID(ctorClass, "<init>", "()V");
    176     DCHECK(ctor != NULL);
    177     return env->NewObject(allocClass, ctor);
    178 }
    179 
    180 static JNINativeMethod gMethods[] = {
    181   NATIVE_METHOD(Constructor, getAnnotationNative,
    182                 "!(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;"),
    183   NATIVE_METHOD(Constructor, getDeclaredAnnotations, "!()[Ljava/lang/annotation/Annotation;"),
    184   NATIVE_METHOD(Constructor, getExceptionTypes, "!()[Ljava/lang/Class;"),
    185   NATIVE_METHOD(Constructor, getParameterAnnotationsNative,
    186                 "!()[[Ljava/lang/annotation/Annotation;"),
    187   NATIVE_METHOD(Constructor, isAnnotationPresentNative, "!(Ljava/lang/Class;)Z"),
    188   NATIVE_METHOD(Constructor, newInstance0, "!([Ljava/lang/Object;)Ljava/lang/Object;"),
    189   NATIVE_METHOD(Constructor, newInstanceFromSerialization, "!(Ljava/lang/Class;Ljava/lang/Class;)Ljava/lang/Object;"),
    190 };
    191 
    192 void register_java_lang_reflect_Constructor(JNIEnv* env) {
    193   REGISTER_NATIVE_METHODS("java/lang/reflect/Constructor");
    194 }
    195 
    196 }  // namespace art
    197