1 /*
2 * Copyright (C) 2018 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 "jni.h"
18 #include "core_jni_helpers.h"
19
20 #include <sstream>
21 #include <iostream>
22 #include <unicode/putil.h>
23 #include <unordered_map>
24 #include <vector>
25
26 using namespace std;
27
28 /*
29 * This is responsible for setting up the JNI environment for communication between
30 * the Java and native parts of layoutlib, including registering native methods.
31 * This is mostly achieved by copying the way it is done in the platform
32 * (see AndroidRuntime.cpp).
33 */
34
35 static JavaVM* javaVM;
36
37 namespace android {
38
39 extern int register_android_animation_PropertyValuesHolder(JNIEnv *env);
40 extern int register_android_content_AssetManager(JNIEnv* env);
41 extern int register_android_content_StringBlock(JNIEnv* env);
42 extern int register_android_content_XmlBlock(JNIEnv* env);
43 extern int register_android_content_res_ApkAssets(JNIEnv* env);
44 extern int register_android_os_FileObserver(JNIEnv* env);
45 extern int register_android_os_MessageQueue(JNIEnv* env);
46 extern int register_android_os_SystemClock(JNIEnv* env);
47 extern int register_android_os_SystemProperties(JNIEnv* env);
48 extern int register_android_os_Trace(JNIEnv* env);
49 extern int register_android_text_AndroidCharacter(JNIEnv* env);
50 extern int register_android_util_EventLog(JNIEnv* env);
51 extern int register_android_util_Log(JNIEnv* env);
52 extern int register_android_util_jar_StrictJarFile(JNIEnv* env);
53 extern int register_com_android_internal_util_VirtualRefBasePtr(JNIEnv *env);
54
55 #define REG_JNI(name) { name }
56 struct RegJNIRec {
57 int (*mProc)(JNIEnv*);
58 };
59
60 // Map of all possible class names to register to their corresponding JNI registration function pointer
61 // The actual list of registered classes will be determined at runtime via the 'native_classes' System property
62 static const std::unordered_map<std::string, RegJNIRec> gRegJNIMap = {
63 {"android.animation.PropertyValuesHolder",
64 REG_JNI(register_android_animation_PropertyValuesHolder)},
65 #ifdef __linux__
66 {"android.content.res.ApkAssets", REG_JNI(register_android_content_res_ApkAssets)},
67 {"android.content.res.AssetManager", REG_JNI(register_android_content_AssetManager)},
68 #endif
69 {"android.content.res.StringBlock", REG_JNI(register_android_content_StringBlock)},
70 {"android.content.res.XmlBlock", REG_JNI(register_android_content_XmlBlock)},
71 #ifdef __linux__
72 {"android.os.FileObserver", REG_JNI(register_android_os_FileObserver)},
73 {"android.os.MessageQueue", REG_JNI(register_android_os_MessageQueue)},
74 #endif
75 {"android.os.SystemClock", REG_JNI(register_android_os_SystemClock)},
76 {"android.os.SystemProperties", REG_JNI(register_android_os_SystemProperties)},
77 {"android.os.Trace", REG_JNI(register_android_os_Trace)},
78 {"android.text.AndroidCharacter", REG_JNI(register_android_text_AndroidCharacter)},
79 {"android.util.EventLog", REG_JNI(register_android_util_EventLog)},
80 {"android.util.Log", REG_JNI(register_android_util_Log)},
81 {"android.util.jar.StrictJarFile", REG_JNI(register_android_util_jar_StrictJarFile)},
82 {"com.android.internal.util.VirtualRefBasePtr",
83 REG_JNI(register_com_android_internal_util_VirtualRefBasePtr)},
84 };
85 // Vector to store the names of classes that need delegates of their native methods
86 static vector<string> classesToDelegate;
87
register_jni_procs(const std::unordered_map<std::string,RegJNIRec> & jniRegMap,const vector<string> & classesToRegister,JNIEnv * env)88 static int register_jni_procs(const std::unordered_map<std::string, RegJNIRec>& jniRegMap,
89 const vector<string>& classesToRegister, JNIEnv* env) {
90
91 for (const string& className : classesToRegister) {
92 if (jniRegMap.at(className).mProc(env) < 0) {
93 return -1;
94 }
95 }
96 return 0;
97 }
98
registerNativeMethods(JNIEnv * env,const char * className,const JNINativeMethod * gMethods,int numMethods)99 int AndroidRuntime::registerNativeMethods(JNIEnv* env,
100 const char* className, const JNINativeMethod* gMethods, int numMethods) {
101 string classNameString = string(className);
102 if (find(classesToDelegate.begin(), classesToDelegate.end(), classNameString)
103 != classesToDelegate.end()) {
104 // Register native methods to the delegate class <classNameString>_NativeDelegate
105 // by adding _Original to the name of each method.
106 replace(classNameString.begin(), classNameString.end(), '$', '_');
107 string delegateClassName = classNameString + "_NativeDelegate";
108 jclass clazz = env->FindClass(delegateClassName.c_str());
109 JNINativeMethod gTypefaceDelegateMethods[numMethods];
110 for (int i = 0; i < numMethods; i++) {
111 JNINativeMethod gTypefaceMethod = gMethods[i];
112 string newName = string(gTypefaceMethod.name) + "_Original";
113 gTypefaceDelegateMethods[i].name = strdup(newName.c_str());
114 gTypefaceDelegateMethods[i].signature = gTypefaceMethod.signature;
115 gTypefaceDelegateMethods[i].fnPtr = gTypefaceMethod.fnPtr;
116 }
117 int result = env->RegisterNatives(clazz, gTypefaceDelegateMethods, numMethods);
118 for (int i = 0; i < numMethods; i++) {
119 free((char*)gTypefaceDelegateMethods[i].name);
120 }
121 return result;
122 }
123
124 jclass clazz = env->FindClass(className);
125 return env->RegisterNatives(clazz, gMethods, numMethods);
126 }
127
getJNIEnv()128 JNIEnv* AndroidRuntime::getJNIEnv() {
129 JNIEnv* env;
130 if (javaVM->GetEnv((void**) &env, JNI_VERSION_1_6) != JNI_OK)
131 return nullptr;
132 return env;
133 }
134
getJavaVM()135 JavaVM* AndroidRuntime::getJavaVM() {
136 return javaVM;
137 }
138
parseCsv(const string & csvString)139 static vector<string> parseCsv(const string& csvString) {
140 vector<string> result;
141 istringstream stream(csvString);
142 string segment;
143 while(getline(stream, segment, ','))
144 {
145 result.push_back(segment);
146 }
147 return result;
148 }
149
parseCsv(JNIEnv * env,jstring csvJString)150 static vector<string> parseCsv(JNIEnv* env, jstring csvJString) {
151 const char* charArray = env->GetStringUTFChars(csvJString, 0);
152 string csvString(charArray);
153 vector<string> result = parseCsv(csvString);
154 env->ReleaseStringUTFChars(csvJString, charArray);
155 return result;
156 }
157
158 } // namespace android
159
160 using namespace android;
161
JNI_OnLoad(JavaVM * vm,void *)162 JNIEXPORT jint JNI_OnLoad(JavaVM* vm, void*) {
163 javaVM = vm;
164 JNIEnv* env = nullptr;
165 if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
166 return JNI_ERR;
167 }
168
169 // Configuration is stored as java System properties.
170 // Get a reference to System.getProperty
171 jclass system = FindClassOrDie(env, "java/lang/System");
172 jmethodID getPropertyMethod = GetStaticMethodIDOrDie(env, system, "getProperty",
173 "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;");
174
175 // Get the names of classes that have to delegate their native methods
176 auto delegateNativesToNativesString =
177 (jstring) env->CallStaticObjectMethod(system,
178 getPropertyMethod, env->NewStringUTF("delegate_natives_to_natives"),
179 env->NewStringUTF(""));
180 classesToDelegate = parseCsv(env, delegateNativesToNativesString);
181
182 // Get the names of classes that need to register their native methods
183 auto nativesClassesJString =
184 (jstring) env->CallStaticObjectMethod(system,
185 getPropertyMethod, env->NewStringUTF("native_classes"),
186 env->NewStringUTF(""));
187 vector<string> classesToRegister = parseCsv(env, nativesClassesJString);
188
189 if (register_jni_procs(gRegJNIMap, classesToRegister, env) < 0) {
190 return JNI_ERR;
191 }
192
193 // Set the location of ICU data
194 auto stringPath = (jstring) env->CallStaticObjectMethod(system,
195 getPropertyMethod, env->NewStringUTF("icu.dir"),
196 env->NewStringUTF(""));
197 const char* path = env->GetStringUTFChars(stringPath, 0);
198 u_setDataDirectory(path);
199 env->ReleaseStringUTFChars(stringPath, path);
200
201
202 return JNI_VERSION_1_6;
203 }
204
205