| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| import com.android.dx.gen.BinaryOp; |
| import com.android.dx.gen.Code; |
| import com.android.dx.gen.DexGenerator; |
| import com.android.dx.gen.FieldId; |
| import com.android.dx.gen.Local; |
| import com.android.dx.gen.MethodId; |
| import com.android.dx.gen.Type; |
| import com.android.dx.rop.code.AccessFlags; |
| import java.io.PrintStream; |
| |
| public class HelloWorldMaker { |
| private static final Type<PrintStream> PRINT_STREAM = Type.get(PrintStream.class); |
| private static final FieldId<System, PrintStream> SYSTEM_OUT |
| = Type.get(System.class).getField(PRINT_STREAM, "out"); |
| private static final MethodId<Integer, String> TO_HEX_STRING |
| = Type.get(Integer.class).getMethod(Type.STRING, "toHexString", Type.INT); |
| private static final MethodId<PrintStream, Void> PRINTLN |
| = PRINT_STREAM.getMethod(Type.VOID, "println", Type.STRING); |
| |
| public static void main(String[] args) throws Exception { |
| |
| /* |
| * This code generates Dalvik bytecode equivalent to the following |
| * program. |
| * |
| * public class HelloWorld { |
| * public static void hello() { |
| * int a = 0xabcd; |
| * int b = 0xaaaa; |
| * int c = a - b; |
| * String s = Integer.toHexString(c); |
| * System.out.println(s); |
| * } |
| * } |
| */ |
| |
| DexGenerator generator = new DexGenerator(); |
| |
| // lookup the symbols of interest |
| Type<?> helloWorld = Type.get("LHelloWorld;"); |
| MethodId hello = helloWorld.getMethod(Type.VOID, "hello"); |
| |
| // create some registers |
| // (I'd like a better syntax for this) |
| Code code = generator.declare(hello, AccessFlags.ACC_STATIC | AccessFlags.ACC_PUBLIC); |
| Local<Integer> a = code.newLocal(Type.INT); |
| Local<Integer> b = code.newLocal(Type.INT); |
| Local<Integer> c = code.newLocal(Type.INT); |
| Local<String> s = code.newLocal(Type.STRING); |
| Local<PrintStream> localSystemOut = code.newLocal(PRINT_STREAM); |
| |
| // specify the code instruction-by-instruction (approximately) |
| code.loadConstant(a, 0xabcd); |
| code.loadConstant(b, 0xaaaa); |
| code.op(BinaryOp.SUBTRACT, c, a, b); |
| code.invokeStatic(TO_HEX_STRING, s, c); |
| code.sget(SYSTEM_OUT, localSystemOut); |
| code.invokeVirtual(PRINTLN, null, localSystemOut, s); |
| code.returnVoid(); |
| |
| // TODO: create the constructor |
| |
| generator.declare(helloWorld, "Generated.java", AccessFlags.ACC_PUBLIC, Type.OBJECT); |
| |
| // load the dex |
| ClassLoader loader = generator.load(HelloWorldMaker.class.getClassLoader()); |
| Class<?> helloWorldClass = loader.loadClass("HelloWorld"); |
| helloWorldClass.getMethod("hello").invoke(null); |
| } |
| } |