1 /*
2 * Copyright (c) 2001, 2003, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 #include "jni.h"
27 #include "jvm.h"
28
29 #include <nativehelper/JNIHelp.h>
30
31 #define NATIVE_METHOD(className, functionName, signature) \
32 { #functionName, signature, (void*)(className ## _ ## functionName) }
33
34 static jclass noSuchMethodErrCl;
35
ObjectStreamClass_initNative(JNIEnv * env)36 static void ObjectStreamClass_initNative(JNIEnv *env)
37 {
38 jclass cl = (*env)->FindClass(env, "java/lang/NoSuchMethodError");
39 if (cl == NULL) { /* exception thrown */
40 return;
41 }
42 noSuchMethodErrCl = (*env)->NewGlobalRef(env, cl);
43 }
44
45 /*
46 * Class: java_io_ObjectStreamClass
47 * Method: hasStaticInitializer
48 * Signature: (Ljava/lang/Class;Z)Z
49 *
50 * Returns true if the given class defines a <clinit>()V method; returns false
51 * otherwise.
52 */
53 JNIEXPORT jboolean JNICALL
54 // Android-changed: Added inheritStaticInitializer parameter.
55 // The inheritStaticInitializer parameter is set to JNI_TRUE when behavior compatible with
56 // Android version 23 is required.
ObjectStreamClass_hasStaticInitializer(JNIEnv * env,jclass this,jclass clazz,jboolean inheritStaticInitializer)57 ObjectStreamClass_hasStaticInitializer(JNIEnv *env, jclass this,
58 jclass clazz,
59 jboolean inheritStaticInitializer)
60 {
61 jclass superCl = NULL;
62 jmethodID superClinitId = NULL;
63
64 // Android-changed: Added comment to explain behavior.
65 // Search for a static initializer method in this class and up through its
66 // ancestor super classes, returning the id of the first method found.
67 jmethodID clinitId =
68 (*env)->GetStaticMethodID(env, clazz, "<clinit>", "()V");
69 if (clinitId == NULL) { /* error thrown */
70 jthrowable th = (*env)->ExceptionOccurred(env);
71 (*env)->ExceptionClear(env); /* normal return */
72 if (!(*env)->IsInstanceOf(env, th, noSuchMethodErrCl)) {
73 (*env)->Throw(env, th);
74 }
75 return JNI_FALSE;
76 }
77
78 // BEGIN Android-changed: Exit immediately if version 23 behavior is required.
79 // At this point the class or one of its ancestor super classes has a
80 // static initializer. If inheritStaticInitializer is true then this method
81 // can simply return true. Otherwise, it needs to check that the static
82 // initializer was not inherited (b/29064453).
83 if (inheritStaticInitializer == JNI_TRUE) {
84 return JNI_TRUE;
85 }
86 // END Android-changed: Exit immediately if version 23 behavior is required.
87
88 /*
89 * Check superclass for static initializer as well--if the same method ID
90 * is returned, then the static initializer is from a superclass.
91 * Empirically, this step appears to be unnecessary in 1.4; however, the
92 * JNI spec makes no guarantee that GetStaticMethodID will not return the
93 * ID for a superclass initializer.
94 */
95
96 if ((superCl = (*env)->GetSuperclass(env, clazz)) == NULL) {
97 return JNI_TRUE;
98 }
99 superClinitId =
100 (*env)->GetStaticMethodID(env, superCl, "<clinit>", "()V");
101 if (superClinitId == NULL) { /* error thrown */
102 jthrowable th = (*env)->ExceptionOccurred(env);
103 (*env)->ExceptionClear(env); /* normal return */
104 if (!(*env)->IsInstanceOf(env, th, noSuchMethodErrCl)) {
105 (*env)->Throw(env, th);
106 }
107 return JNI_TRUE;
108 }
109
110 return (clinitId != superClinitId);
111 }
112
113 static JNINativeMethod gMethods[] = {
114 NATIVE_METHOD(ObjectStreamClass, hasStaticInitializer, "(Ljava/lang/Class;Z)Z"),
115 };
116
register_java_io_ObjectStreamClass(JNIEnv * env)117 void register_java_io_ObjectStreamClass(JNIEnv* env) {
118 jniRegisterNativeMethods(env, "java/io/ObjectStreamClass", gMethods, NELEM(gMethods));
119 ObjectStreamClass_initNative(env);
120 }
121