1 /*
2 * Copyright (c) 2011, 2013, 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 package com.apple.jobjc;
26
27 import java.io.StringWriter;
28 import java.lang.reflect.Method;
29 import java.util.HashSet;
30 import java.util.Set;
31
32 import com.apple.jobjc.Coder.PrimitivePointerCoder;
33 import com.apple.jobjc.Coder.VoidCoder;
34 import com.apple.jobjc.Invoke.MsgSend;
35
36
37 final class Subclassing {
38 static native long allocateClassPair(long superClass, String name);
39 static native boolean addIVarForJObj(long clazz);
40 static native boolean patchAlloc(long classPtr);
41 static native boolean addMethod(long cls, String name, Method jMethod, CIF cif, long cifPtr, String objCEncodedType);
42 static native void registerClassPair(long clazz);
43
44 static native <T extends ID> T getJObjectFromIVar(long objPtr);
45 static native void initJObjectToIVar(long objPtr, ID object);
46
47 final Set<Long> registeredUserSubclasses = new HashSet<Long>();
48 final JObjCRuntime runtime;
49
50 Subclassing(JObjCRuntime runtime){
51 this.runtime = runtime;
52 }
53
54 boolean registerUserClass(final Class<? extends ID> clazz, final Class<? extends NSClass> clazzClazz) {
55 final String nativeClassName = clazz.getSimpleName();
56 // Is it already registered?
57 if(0 != NSClass.getNativeClassByName(nativeClassName))
58 return false;
59
60 if(clazz.isAnonymousClass())
61 throw new RuntimeException("JObjC cannot register anonymous classes.");
62
63 // Verify superclass
64 long superClass = NSClass.getNativeClassByName(clazz.getSuperclass().getSimpleName());
65 if(0 == superClass)
66 throw new RuntimeException(clazz.getSuperclass() + ", the superclass of " + clazz + ", must be a registered class.");
67
68 runtime.registerPackage(clazz.getPackage().getName());
69
70 // Create class
71 long classPtr = Subclassing.allocateClassPair(superClass, nativeClassName);
72 if(classPtr == 0) throw new RuntimeException("objc_allocateClassPair returned 0.");
73
74 // Add ivar to hold jobject
75 boolean addedI = Subclassing.addIVarForJObj(classPtr);
76 if(!addedI) throw new RuntimeException("class_addIvar returned false.");
77
78 // Verify constructor
79 try {
80 clazz.getConstructor(ID.CTOR_ARGS);
81 } catch (Exception e) {
82 throw new RuntimeException("Could not access required constructor: " + ID.CTOR_ARGS, e);
83 }
84
85 // Patch alloc to create corresponding jobject on invoke
86 patchAlloc(classPtr);
87
88 // Add methods
89 Set<String> takenSelNames = new HashSet<String>();
90 for(Method method : clazz.getDeclaredMethods()){
91 // No overloading
92 String selName = SEL.selectorName(method.getName(), method.getParameterTypes().length > 0);
93 if(takenSelNames.contains(selName))
94 throw new RuntimeException("Obj-C does not allow method overloading. The Objective-C selector '"
95 + selName + "' appears more than once in class " + clazz.getCanonicalName() + " / " + nativeClassName + ".");
96
97 method.setAccessible(true);
98
99 // Divine CIF
100 Coder returnCoder = Coder.getCoderAtRuntimeForType(method.getReturnType());
101 Class[] paramTypes = method.getParameterTypes();
102 Coder[] argCoders = new Coder[paramTypes.length];
103 for(int i = 0; i < paramTypes.length; i++)
104 argCoders[i] = Coder.getCoderAtRuntimeForType(paramTypes[i]);
105
106 CIF cif = new MsgSend(runtime, selName, returnCoder, argCoders).funCall.cif;
107
108 // .. and objc encoding
109 StringWriter encType = new StringWriter();
110 encType.append(returnCoder.getObjCEncoding());
111 encType.append("@:");
112 for(int i = 0; i < argCoders.length; i++)
113 encType.append(argCoders[i].getObjCEncoding());
114
115 // Add it!
116 boolean addedM = Subclassing.addMethod(classPtr, selName, method, cif, cif.cif.bufferPtr, encType.toString());
117 if(!addedM) throw new RuntimeException("Failed to add method.");
118 takenSelNames.add(selName);
119 }
120
121 // Seal it
122 Subclassing.registerClassPair(classPtr);
123 registeredUserSubclasses.add(classPtr);
124
125 return true;
126 }
127
128 boolean isUserClass(long clsPtr) {
129 return registeredUserSubclasses.contains(clsPtr);
130 }
131
132 // Called from JNI
133
134 private static void initJObject(final long objPtr){
135 // System.err.println("initJObject " + objPtr + " / " + Long.toHexString(objPtr));
136 ID newObj = ID.createNewObjCObjectFor(JObjCRuntime.inst(), objPtr, NSClass.getClass(objPtr));
137 // System.err.println("... " + newObj);
138 initJObjectToIVar(objPtr, newObj);
139 }
140
141 private static void invokeFromJNI(ID obj, Method method, CIF cif, long result, long args){
142 assert obj != null;
143 assert obj.getClass().equals(method.getDeclaringClass()) :
144 obj.getClass().toString() + " != " + method.getDeclaringClass().toString();
145
146 final int argCount = method.getParameterTypes().length;
147
148 // The first two args & coders are for objc id and sel. Skip them.
149 final Object[] argObjects = new Object[argCount];
150 for(int i = 0; i < argCount; i++){
151 final long argAddrAddr = args + ((i+2) * JObjCRuntime.PTR_LEN);
152 final long argAddr = PrimitivePointerCoder.INST.popPtr(obj.runtime, argAddrAddr);
153 argObjects[i] = cif.argCoders[i + 2].pop(obj.runtime, argAddr);
154 }
155
156 Object retVal;
157 try {
158 retVal = method.invoke(obj, argObjects);
159 } catch (Exception e) {
160 e.printStackTrace();
161 throw new RuntimeException(e);
162 }
163
164 if(!(cif.returnCoder instanceof VoidCoder))
165 cif.returnCoder.push(obj.runtime, result, retVal);
166 }
167 }