1 /*
2  * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
3  * Copyright (c) 2018, 2019, Google and/or its affiliates. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.
9  *
10  * This code is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License version
17  * 2 along with this work; if not, write to the Free Software Foundation,
18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21  * or visit www.oracle.com if you need additional information or have any
22  * questions.
23  */
24 #ifndef NSK_EXCEPTIONCHECKINGJNIENV_DEFINED
25 #define NSK_EXCEPTIONCHECKINGJNIENV_DEFINED
26 
27 #include <jni.h>
28 
29 /**
30  * ExceptionCheckingJniEnv wraps around the JNIEnv data structure and
31  * methods to enable automatic exception checking. This allows test writers
32  * and readers to concentrate on what the test is to do and leave the
33  * error checking and throwing to this data structure and subsystem.
34  *
35  * For example:
36  *
37  * ... JNIEnv* env ...
38  *  jclass klass = env->GetObjectClass(o);
39  *  if (klass == NULL) {
40  *      printf("Error: GetObjectClass returned NULL\n");
41  *      return;
42  *  }
43  *  if (env->ExceptionCheck()) {
44  *    ...
45  *  }
46  *
47  *  Can be simplified to:
48  * ... ExceptionCheckingJniEnv* env ...
49  *  jclass klass = env->GetObjectClass(o, TRACE_JNI_CALL);
50  *
51  *  Where now the JNI Exception checking and the NULL return checking are done
52  *  internally and will perform whatever action the ErrorHandler requires.
53  *
54  *  Note the TRACE_JNI_CALL parameter that allows to trace where the call is
55  *  happening from for debugging.
56  *
57  *  By default, the error handler describes the exception via the JNI
58  *  ExceptionDescribe method and calls FatalError.
59  */
60 
61 #define TRACE_JNI_CALL __LINE__, __FILE__
62 #define TRACE_JNI_CALL_VARARGS(...) __LINE__, __FILE__, __VA_ARGS__
63 
64 class ExceptionCheckingJniEnv {
65  public:
66   // JNIEnv API redefinitions.
67   jclass FindClass(const char *name, int line, const char* file_name);
68 
69   jfieldID GetStaticFieldID(jclass klass, const char* name, const char* type,
70                             int line, const char* file_name);
71   jfieldID GetFieldID(jclass klass, const char* name, const char* type,
72                       int line, const char* file_name);
73   jmethodID GetStaticMethodID(jclass klass, const char* name, const char* sig,
74                               int line, const char* file_name);
75   jmethodID GetMethodID(jclass klass, const char* name, const char* sig,
76                         int line, const char* file_name);
77 
78   jclass GetObjectClass(jobject obj, int line, const char* file_name);
79   jobject GetObjectField(jobject obj, jfieldID field, int line, const char* file_name);
80   jobject GetStaticObjectField(jclass kls, jfieldID field, int line, const char* file_name);
81   void SetObjectField(jobject obj, jfieldID field, jobject value,
82                       int line, const char* file_name);
83 
84   jsize GetArrayLength(jarray array, int line, const char* file_name);
85   jsize GetStringLength(jstring str, int line, const char* file_name);
86 
87   void* GetPrimitiveArrayCritical(jarray array, jboolean* isCopy,
88                                   int line, const char* file_name);
89   void ReleasePrimitiveArrayCritical(jarray array, void* carray, jint mode,
90                                      int line, const char* file_name);
91   const jchar* GetStringCritical(jstring str, jboolean* isCopy,
92                                  int line, const char* file_name);
93   void ReleaseStringCritical(jstring str, const jchar* carray,
94                              int line, const char* file_name);
95 
96   jbyte* GetByteArrayElements(jbyteArray array, jboolean* isCopy,
97                               int line, const char* file_name);
98   void ReleaseByteArrayElements(jbyteArray array, jbyte* byte_array, jint mode,
99                                 int line, const char* file_name);
100   jint RegisterNatives(jclass clazz, const JNINativeMethod *methods, jint nMethods,
101                        int line, const char* file_name);
102 
103   jobject NewObject(jclass kls, jmethodID methodID,
104                     int line, const char* file_name, ...);
105   jobject NewGlobalRef(jobject obj, int line, const char* file_name);
106   void DeleteGlobalRef(jobject obj, int line, const char* file_name);
107   jobject NewLocalRef(jobject ref, int line, const char* file_name);
108   void DeleteLocalRef(jobject ref, int line, const char* file_name);
109   jweak NewWeakGlobalRef(jobject obj, int line, const char* file_name);
110   void DeleteWeakGlobalRef(jweak obj, int line, const char* file_name);
111 
112   jboolean IsSameObject(jobject ref1, jobject ref2, int line,
113                         const char* file_name);
114 
115   jobject CallObjectMethod(jobject obj, jmethodID methodID, int line,
116                            const char* file_name, ...);
117   void CallVoidMethod(jobject obj, jmethodID methodID, int line,
118                       const char* file_name, ...);
119 
120   // ExceptionCheckingJniEnv methods.
GetJNIEnv()121   JNIEnv* GetJNIEnv() {
122     return _jni_env;
123   }
124 
HandleError(const char * msg)125   void HandleError(const char* msg) {
126     if (_error_handler) {
127       _error_handler(_jni_env, msg);
128     }
129   }
130 
131   typedef void (*ErrorHandler)(JNIEnv* env, const char* error_message);
132 
FatalError(JNIEnv * env,const char * message)133   static void FatalError(JNIEnv* env, const char* message) {
134     if (env->ExceptionCheck()) {
135       env->ExceptionDescribe();
136     }
137     env->FatalError(message);
138   }
139 
ExceptionCheckingJniEnv(JNIEnv * jni_env,ErrorHandler error_handler)140   ExceptionCheckingJniEnv(JNIEnv* jni_env, ErrorHandler error_handler) :
141     _jni_env(jni_env), _error_handler(error_handler) {}
142 
143  private:
144   JNIEnv* _jni_env;
145   ErrorHandler _error_handler;
146 };
147 
148 // We cannot use unique_ptr due to this being gnu98++, so use this instead:
149 class ExceptionCheckingJniEnvPtr {
150  private:
151   ExceptionCheckingJniEnv _env;
152 
153  public:
operator ->()154   ExceptionCheckingJniEnv* operator->() {
155     return &_env;
156   }
157 
ExceptionCheckingJniEnvPtr(JNIEnv * jni_env,ExceptionCheckingJniEnv::ErrorHandler error_handler=ExceptionCheckingJniEnv::FatalError)158   ExceptionCheckingJniEnvPtr(
159       JNIEnv* jni_env,
160       ExceptionCheckingJniEnv::ErrorHandler error_handler = ExceptionCheckingJniEnv::FatalError) :
161           _env(jni_env, error_handler) {
162   }
163 };
164 
165 #endif
166