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 "jni_internal.h"
22 #include "mirror/class-inl.h"
23 #include "mirror/method.h"
24 #include "mirror/object-inl.h"
25 #include "reflection.h"
26 #include "scoped_fast_native_object_access.h"
27 #include "well_known_classes.h"
28 
29 namespace art {
30 
31 /*
32  * We can also safely assume the constructor isn't associated
33  * with an interface, array, or primitive class. If this is coming from
34  * native, it is OK to avoid access checks since JNI does not enforce them.
35  */
Constructor_newInstance(JNIEnv * env,jobject javaMethod,jobjectArray javaArgs)36 static jobject Constructor_newInstance(JNIEnv* env, jobject javaMethod, jobjectArray javaArgs) {
37   ScopedFastNativeObjectAccess soa(env);
38   mirror::Constructor* m = soa.Decode<mirror::Constructor*>(javaMethod);
39   StackHandleScope<1> hs(soa.Self());
40   Handle<mirror::Class> c(hs.NewHandle(m->GetDeclaringClass()));
41   if (UNLIKELY(c->IsAbstract())) {
42     soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;", "Can't instantiate %s %s",
43                                    c->IsInterface() ? "interface" : "abstract class",
44                                    PrettyDescriptor(c.Get()).c_str());
45     return nullptr;
46   }
47   // Verify that we can access the class.
48   if (!m->IsAccessible() && !c->IsPublic()) {
49     auto* caller = GetCallingClass(soa.Self(), 1);
50     // If caller is null, then we called from JNI, just avoid the check since JNI avoids most
51     // access checks anyways. TODO: Investigate if this the correct behavior.
52     if (caller != nullptr && !caller->CanAccess(c.Get())) {
53       if (PrettyDescriptor(c.Get()) == "dalvik.system.DexPathList$Element") {
54         // b/20699073.
55         LOG(WARNING) << "The dalvik.system.DexPathList$Element constructor is not accessible by "
56                         "default. This is a temporary workaround for backwards compatibility "
57                         "with class-loader hacks. Please update your application.";
58       } else {
59         soa.Self()->ThrowNewExceptionF(
60             "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
61             PrettyClass(c.Get()).c_str(), PrettyClass(caller).c_str());
62         return nullptr;
63       }
64     }
65   }
66   if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(soa.Self(), c, true, true)) {
67     DCHECK(soa.Self()->IsExceptionPending());
68     return nullptr;
69   }
70   bool movable = true;
71   if (!kMovingClasses && c->IsClassClass()) {
72     movable = false;
73   }
74 
75   // String constructor is replaced by a StringFactory method in InvokeMethod.
76   if (c->IsStringClass()) {
77     return InvokeMethod(soa, javaMethod, nullptr, javaArgs, 1);
78   }
79 
80   mirror::Object* receiver =
81       movable ? c->AllocObject(soa.Self()) : c->AllocNonMovableObject(soa.Self());
82   if (receiver == nullptr) {
83     return nullptr;
84   }
85   jobject javaReceiver = soa.AddLocalReference<jobject>(receiver);
86   InvokeMethod(soa, javaMethod, javaReceiver, javaArgs, 1);
87   // Constructors are ()V methods, so we shouldn't touch the result of InvokeMethod.
88   return javaReceiver;
89 }
90 
91 static JNINativeMethod gMethods[] = {
92   NATIVE_METHOD(Constructor, newInstance, "!([Ljava/lang/Object;)Ljava/lang/Object;"),
93 };
94 
register_java_lang_reflect_Constructor(JNIEnv * env)95 void register_java_lang_reflect_Constructor(JNIEnv* env) {
96   REGISTER_NATIVE_METHODS("java/lang/reflect/Constructor");
97 }
98 
99 }  // namespace art
100