FibonacciMaker.java revision 0e49fb9243b7463835ab80ef7cc62435f55846ce 
1/*
2 * Copyright (C) 2012 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
17package com.google.dexmaker.examples;
18
19import com.google.dexmaker.BinaryOp;
20import com.google.dexmaker.Code;
21import com.google.dexmaker.Comparison;
22import com.google.dexmaker.DexMaker;
23import com.google.dexmaker.Label;
24import com.google.dexmaker.Local;
25import com.google.dexmaker.MethodId;
26import com.google.dexmaker.TypeId;
27import java.io.File;
28import java.lang.reflect.Method;
29import java.lang.reflect.Modifier;
30
31public final class FibonacciMaker {
32    public static void main(String[] args) throws Exception {
33        DexMaker dexMaker = new DexMaker();
34        TypeId<?> fibonacci = TypeId.get("Lcom/google/dexmaker/examples/Fibonacci;");
35        String fileName = "Fibonacci.generated";
36        dexMaker.declare(fibonacci, fileName, Modifier.PUBLIC, TypeId.OBJECT);
37
38        MethodId<?, Integer> fib = fibonacci.getMethod(TypeId.INT, "fib", TypeId.INT);
39        Code code = dexMaker.declare(fib, Modifier.PUBLIC | Modifier.STATIC);
40        Local<Integer> i = code.getParameter(0, TypeId.INT);
41        Local<Integer> constant1 = code.newLocal(TypeId.INT);
42        Local<Integer> constant2 = code.newLocal(TypeId.INT);
43        Local<Integer> a = code.newLocal(TypeId.INT);
44        Local<Integer> b = code.newLocal(TypeId.INT);
45        Local<Integer> c = code.newLocal(TypeId.INT);
46        Local<Integer> d = code.newLocal(TypeId.INT);
47        Local<Integer> result = code.newLocal(TypeId.INT);
48        code.loadConstant(constant1, 1);
49        code.loadConstant(constant2, 2);
50        Label baseCase = code.newLabel();
51        code.compare(Comparison.LT, baseCase, i, constant2);
52        code.op(BinaryOp.SUBTRACT, a, i, constant1);
53        code.op(BinaryOp.SUBTRACT, b, i, constant2);
54        code.invokeStatic(fib, c, a);
55        code.invokeStatic(fib, d, b);
56        code.op(BinaryOp.ADD, result, c, d);
57        code.returnValue(result);
58        code.mark(baseCase);
59        code.returnValue(i);
60
61        ClassLoader loader = dexMaker.generateAndLoad(
62                FibonacciMaker.class.getClassLoader(), getDataDirectory(), getDataDirectory());
63        Class<?> fibonacciClass = loader.loadClass("com.google.dexmaker.examples.Fibonacci");
64        Method fibMethod = fibonacciClass.getMethod("fib", int.class);
65        System.out.println(fibMethod.invoke(null, 8));
66    }
67
68    public static File getDataDirectory() throws Exception {
69        Class<?> environmentClass = Class.forName("android.os.Environment");
70        Method method = environmentClass.getMethod("getDataDirectory");
71        Object dataDirectory = method.invoke(null);
72        return (File) dataDirectory;
73    }
74}
75