2 * Back 2 Browser Bytecode Translator
3 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, version 2 of the License.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. Look for COPYING file in the top folder.
16 * If not, see http://opensource.org/licenses/GPL-2.0.
18 package org.apidesign.vm4brwsr;
20 import java.io.IOException;
21 import org.apidesign.vm4brwsr.ByteCodeParser.TypeArray;
23 final class StackMapper {
24 private final TypeArray stackTypeIndexPairs;
25 private final StringArray stackValues;
27 public StackMapper() {
28 stackTypeIndexPairs = new TypeArray();
29 stackValues = new StringArray();
33 stackTypeIndexPairs.clear();
37 public void syncWithFrameStack(final TypeArray frameStack) {
40 final int size = frameStack.getSize();
41 for (int i = 0; i < size; ++i) {
42 pushTypeImpl(VarType.fromStackMapType(frameStack.get(i)));
46 public Variable pushI() {
47 return pushT(VarType.INTEGER);
50 public Variable pushL() {
51 return pushT(VarType.LONG);
54 public Variable pushF() {
55 return pushT(VarType.FLOAT);
58 public Variable pushD() {
59 return pushT(VarType.DOUBLE);
62 public Variable pushA() {
63 return pushT(VarType.REFERENCE);
66 public Variable pushT(final int type) {
67 return getVariable(pushTypeImpl(type));
70 void assign(Appendable out, int varType, CharSequence s) throws IOException {
71 pushTypeAndValue(varType, s);
75 void flush(Appendable out) throws IOException {
76 int count = stackTypeIndexPairs.getSize();
77 for (int i = 0; i < count; i++) {
78 String val = stackValues.getAndClear(i);
82 CharSequence var = getVariable(stackTypeIndexPairs.get(i));
83 ByteCodeToJavaScript.emitImpl(out, "var @1 = @2;", var, val);
87 public Variable popI() {
88 return popT(VarType.INTEGER);
91 public Variable popL() {
92 return popT(VarType.LONG);
95 public Variable popF() {
96 return popT(VarType.FLOAT);
99 public Variable popD() {
100 return popT(VarType.DOUBLE);
103 public Variable popA() {
104 return popT(VarType.REFERENCE);
107 public Variable popT(final int type) {
108 final Variable variable = getT(0, type);
113 public Variable pop() {
114 final Variable variable = get(0);
119 public void pop(final int count) {
120 final int stackSize = stackTypeIndexPairs.getSize();
121 if (count > stackSize) {
122 throw new IllegalStateException("Stack underflow");
127 public Variable getI(final int indexFromTop) {
128 return getT(indexFromTop, VarType.INTEGER);
131 public Variable getL(final int indexFromTop) {
132 return getT(indexFromTop, VarType.LONG);
135 public Variable getF(final int indexFromTop) {
136 return getT(indexFromTop, VarType.FLOAT);
139 public Variable getD(final int indexFromTop) {
140 return getT(indexFromTop, VarType.DOUBLE);
143 public Variable getA(final int indexFromTop) {
144 return getT(indexFromTop, VarType.REFERENCE);
147 public Variable getT(final int indexFromTop, final int type) {
148 final int stackSize = stackTypeIndexPairs.getSize();
149 if (indexFromTop >= stackSize) {
150 throw new IllegalStateException("Stack underflow");
152 final int stackValue =
153 stackTypeIndexPairs.get(stackSize - indexFromTop - 1);
154 if ((stackValue & 0xff) != type) {
155 throw new IllegalStateException("Type mismatch");
158 return getVariable(stackValue);
161 public Variable get(final int indexFromTop) {
162 final int stackSize = stackTypeIndexPairs.getSize();
163 if (indexFromTop >= stackSize) {
164 throw new IllegalStateException("Stack underflow");
166 final int stackValue =
167 stackTypeIndexPairs.get(stackSize - indexFromTop - 1);
169 return getVariable(stackValue);
172 private int pushTypeImpl(final int type) {
173 final int count = stackTypeIndexPairs.getSize();
174 final int value = (count << 8) | (type & 0xff);
175 stackTypeIndexPairs.add(value);
177 addStackValue(count, null);
181 private void pushTypeAndValue(final int type, CharSequence v) {
182 final int count = stackTypeIndexPairs.getSize();
183 final int value = (count << 8) | (type & 0xff);
184 stackTypeIndexPairs.add(value);
185 final String val = v.toString();
186 addStackValue(count, val);
189 private void addStackValue(int at, final String val) {
190 final String[] arr = stackValues.toArray();
191 if (arr.length > at) {
194 stackValues.add(val);
198 private void popImpl(final int count) {
199 final int stackSize = stackTypeIndexPairs.getSize();
200 stackTypeIndexPairs.setSize(stackSize - count);
203 public Variable getVariable(final int typeAndIndex) {
204 final int type = typeAndIndex & 0xff;
205 final int index = typeAndIndex >> 8;
207 return Variable.getStackVariable(type, index);