Java tutorial
/* * Copyright 2015 Google Inc. * * 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. */ package com.google.template.soy.jbcsrc; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.Label; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; import org.objectweb.asm.Type; import org.objectweb.asm.commons.GeneratorAdapter; import org.objectweb.asm.commons.LocalVariablesSorter; import org.objectweb.asm.commons.Method; import org.objectweb.asm.commons.TableSwitchGenerator; import javax.annotation.Nullable; /** * A {@link MethodVisitor} that acts as a substitute for {@link GeneratorAdapter}. * * <p>{@link GeneratorAdapter} has lots of convient methods (like * {@link GeneratorAdapter#push(int)}), however it is a subtype of {@link LocalVariablesSorter} * which automatically renumbers local variables. This is actually fine (i think), but the problem * is that it makes our debugging information (like {@link ClassData#toString()} or * {@link Expression#trace()}) very misleading since none of the local variable indices in the debug * information match the indexes in the generated code, so the debug data just looks wrong. * * <p>So instead we use forwarding to reuse the safe subset of the {@link GeneratorAdapter} api and * this allows us to skip past all the local variable munging. */ final class CodeBuilder extends MethodVisitor { private final GeneratorAdapter adapter; CodeBuilder(int access, Method method, MethodVisitor mv) { this(mv, access, method.getName(), method.getDescriptor()); } CodeBuilder(int access, Method method, @Nullable Type[] exceptions, ClassVisitor cv) { this(access, method, cv.visitMethod(access, method.getName(), method.getDescriptor(), null /* generic signature */, getInternalNames(exceptions))); } CodeBuilder(MethodVisitor mv, int access, String name, String desc) { super(Opcodes.ASM5, mv); this.adapter = new GeneratorAdapter(mv, access, name, desc); } private static String[] getInternalNames(@Nullable Type[] types) { if (types == null) { return null; } String[] names = new String[types.length]; for (int i = 0; i < names.length; ++i) { names[i] = types[i].getInternalName(); } return names; } /** See {@link GeneratorAdapter#push(boolean)} */ public void pushBoolean(boolean value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(int)} */ public void pushInt(int value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(long)} */ public void pushLong(long value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(float)} */ public void pushFloat(float value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(double)} */ public void pushDouble(double value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(String)} */ public void pushString(String value) { adapter.push(value); } /** See {@link GeneratorAdapter#push(Type)} */ public void pushType(Type value) { adapter.push(value); } /** See {@link GeneratorAdapter#loadThis()} */ public void loadThis() { adapter.loadThis(); } /** See {@link GeneratorAdapter#loadArgs()} */ public void loadArgs() { adapter.loadArgs(); } /** See {@link GeneratorAdapter#pop()} */ public void pop() { adapter.pop(); } /** See {@link GeneratorAdapter#pop2()} */ public void pop2() { adapter.pop2(); } /** See {@link GeneratorAdapter#dup()} */ public void dup() { adapter.dup(); } /** See {@link GeneratorAdapter#dupX1()} */ public void dupX1() { adapter.dupX1(); } /** See {@link GeneratorAdapter#dupX2()} */ public void dupX2() { adapter.dupX2(); } /** See {@link GeneratorAdapter#dup2()} */ public void dup2() { adapter.dup2(); } /** See {@link GeneratorAdapter#dup2X1()} */ public void dup2X1() { adapter.dup2X1(); } /** See {@link GeneratorAdapter#dup2X2()} */ public void dup2X2() { adapter.dup2X2(); } /** See {@link GeneratorAdapter#iinc(int, int)} */ public void iinc(int local, int amount) { adapter.iinc(local, amount); } /** See {@link GeneratorAdapter#cast} */ public void cast(Type from, Type to) { adapter.cast(from, to); } /** See {@link GeneratorAdapter#box(Type)} */ public void box(Type type) { adapter.box(type); } /** See {@link GeneratorAdapter#valueOf(Type)} */ public void valueOf(Type type) { adapter.valueOf(type); } /** See {@link GeneratorAdapter#unbox(Type)} */ public void unbox(Type type) { adapter.unbox(type); } /** See {@link GeneratorAdapter#newLabel()} */ public Label newLabel() { return adapter.newLabel(); } /** See {@link GeneratorAdapter#mark(Label)} */ public void mark(Label label) { adapter.mark(label); } /** See {@link GeneratorAdapter#mark()} */ public Label mark() { return adapter.mark(); } /** See {@link GeneratorAdapter#ifCmp} */ public void ifCmp(Type type, int mode, Label label) { adapter.ifCmp(type, mode, label); } /** See {@link GeneratorAdapter#ifICmp(int, Label)} */ public void ifICmp(int mode, Label label) { adapter.ifICmp(mode, label); } /** See {@link GeneratorAdapter#ifZCmp(int, Label)} */ public void ifZCmp(int mode, Label label) { adapter.ifZCmp(mode, label); } /** See {@link GeneratorAdapter#ifNull(Label)} */ public void ifNull(Label label) { adapter.ifNull(label); } /** See {@link GeneratorAdapter#ifNonNull(Label)} */ public void ifNonNull(Label label) { adapter.ifNonNull(label); } /** See {@link GeneratorAdapter#goTo(Label)} */ public void goTo(Label label) { adapter.goTo(label); } /** See {@link GeneratorAdapter#tableSwitch(int[], TableSwitchGenerator)} */ public void tableSwitch(int[] keys, TableSwitchGenerator generator) { adapter.tableSwitch(keys, generator); } /** See {@link GeneratorAdapter#tableSwitch(int[], TableSwitchGenerator, boolean)} */ public void tableSwitch(int[] keys, TableSwitchGenerator generator, boolean useTable) { adapter.tableSwitch(keys, generator, useTable); } /** See {@link GeneratorAdapter#returnValue()} */ public void returnValue() { adapter.returnValue(); } /** See {@link GeneratorAdapter#getStatic(Type, String, Type)} */ public void getStatic(Type owner, String name, Type type) { adapter.getStatic(owner, name, type); } /** See {@link GeneratorAdapter#getField(Type, String, Type)} */ public void getField(Type owner, String name, Type type) { adapter.getField(owner, name, type); } /** See {@link GeneratorAdapter#putField(Type, String, Type)} */ public void putField(Type owner, String name, Type type) { adapter.putField(owner, name, type); } /** See {@link GeneratorAdapter#putStatic(Type, String, Type)} */ public void putStatic(Type owner, String name, Type type) { adapter.putStatic(owner, name, type); } /** See {@link GeneratorAdapter#invokeVirtual(Type, Method)} */ public void invokeVirtual(Type owner, Method method) { adapter.invokeVirtual(owner, method); } /** See {@link GeneratorAdapter#invokeConstructor(Type, Method)} */ public void invokeConstructor(Type type, Method method) { adapter.invokeConstructor(type, method); } /** See {@link GeneratorAdapter#newInstance(Type)} */ public void newInstance(Type type) { adapter.newInstance(type); } /** See {@link GeneratorAdapter#newArray(Type)} */ public void newArray(Type type) { adapter.newArray(type); } /** See {@link GeneratorAdapter#arrayLength()} */ public void arrayLength() { adapter.arrayLength(); } /** See {@link GeneratorAdapter#throwException()} */ public void throwException() { adapter.throwException(); } /** See {@link GeneratorAdapter#throwException(Type, String)} */ public void throwException(Type type, String msg) { adapter.throwException(type, msg); } /** See {@link GeneratorAdapter#checkCast(Type)} */ public void checkCast(Type type) { adapter.checkCast(type); } /** See {@link GeneratorAdapter#endMethod()} */ public void endMethod() { adapter.endMethod(); } /** See {@link GeneratorAdapter#swap()} */ public void swap() { adapter.swap(); } }