lubomir@307: /**
lubomir@307:  * Back 2 Browser Bytecode Translator
lubomir@307:  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
lubomir@307:  *
lubomir@307:  * This program is free software: you can redistribute it and/or modify
lubomir@307:  * it under the terms of the GNU General Public License as published by
lubomir@307:  * the Free Software Foundation, version 2 of the License.
lubomir@307:  *
lubomir@307:  * This program is distributed in the hope that it will be useful,
lubomir@307:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
lubomir@307:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
lubomir@307:  * GNU General Public License for more details.
lubomir@307:  *
lubomir@307:  * You should have received a copy of the GNU General Public License
lubomir@307:  * along with this program. Look for COPYING file in the top folder.
lubomir@307:  * If not, see http://opensource.org/licenses/GPL-2.0.
lubomir@307:  */
lubomir@307: package org.apidesign.vm4brwsr;
lubomir@307: 
lubomir@307: import java.io.IOException;
lubomir@307: import org.apidesign.javap.RuntimeConstants;
lubomir@307: import org.apidesign.javap.TypeArray;
lubomir@307: 
lubomir@307: public final class LocalsMapper {
lubomir@307:     private final TypeArray argTypeRecords;
lubomir@307:     private final TypeArray localTypeRecords;
lubomir@307: 
lubomir@307:     public LocalsMapper(final TypeArray stackMapArgs) {
lubomir@307:         final TypeArray initTypeRecords = new TypeArray();
lubomir@307:         updateRecords(initTypeRecords, stackMapArgs);
lubomir@307: 
lubomir@307:         argTypeRecords = initTypeRecords;
lubomir@307:         localTypeRecords = new TypeArray(initTypeRecords);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public void outputArguments(final Appendable out) throws IOException {
lubomir@307:         final int argRecordCount = argTypeRecords.getSize();
lubomir@307:         if (argRecordCount > 0) {
lubomir@307:             Variable variable = getVariable(argTypeRecords, 0);
lubomir@307:             out.append(variable);
lubomir@307: 
lubomir@307:             int i = variable.isCategory2() ? 2 : 1;
lubomir@307:             while (i < argRecordCount) {
lubomir@307:                 variable = getVariable(argTypeRecords, i);
lubomir@307:                 out.append(", ");
lubomir@307:                 out.append(variable);
lubomir@307:                 i += variable.isCategory2() ? 2 : 1;
lubomir@307:             }
lubomir@307:         }
lubomir@307:     }
lubomir@307: 
lubomir@307:     public void syncWithFrameLocals(final TypeArray frameLocals) {
lubomir@307:         updateRecords(localTypeRecords, frameLocals);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setI(final int index) {
lubomir@307:         return setT(index, VarType.INTEGER);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setL(final int index) {
lubomir@307:         return setT(index, VarType.LONG);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setF(final int index) {
lubomir@307:         return setT(index, VarType.FLOAT);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setD(final int index) {
lubomir@307:         return setT(index, VarType.DOUBLE);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setA(final int index) {
lubomir@307:         return setT(index, VarType.REFERENCE);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable setT(final int index, final int type) {
lubomir@307:         updateRecord(localTypeRecords, index, type);
lubomir@307:         return Variable.getLocalVariable(type, index);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getI(final int index) {
lubomir@307:         return getT(index, VarType.INTEGER);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getL(final int index) {
lubomir@307:         return getT(index, VarType.LONG);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getF(final int index) {
lubomir@307:         return getT(index, VarType.FLOAT);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getD(final int index) {
lubomir@307:         return getT(index, VarType.DOUBLE);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getA(final int index) {
lubomir@307:         return getT(index, VarType.REFERENCE);
lubomir@307:     }
lubomir@307: 
lubomir@307:     public Variable getT(final int index, final int type) {
lubomir@307:         final int oldRecordValue = localTypeRecords.get(index);
lubomir@307:         if ((oldRecordValue & 0xff) != type) {
lubomir@307:             throw new IllegalStateException("Type mismatch");
lubomir@307:         }
lubomir@307: 
lubomir@307:         return Variable.getLocalVariable(type, index);
lubomir@307:     }
lubomir@307: 
lubomir@307:     private static void updateRecords(final TypeArray typeRecords,
lubomir@307:                                       final TypeArray stackMapTypes) {
lubomir@307:         final int srcSize = stackMapTypes.getSize();
lubomir@307:         for (int i = 0, dstIndex = 0; i < srcSize; ++i) {
lubomir@307:             final int smType = stackMapTypes.get(i);
lubomir@307:             if (smType == RuntimeConstants.ITEM_Bogus) {
lubomir@307:                 ++dstIndex;
lubomir@307:                 continue;
lubomir@307:             }
lubomir@307:             final int varType = VarType.fromStackMapType(smType);
lubomir@307:             updateRecord(typeRecords, dstIndex, varType);
lubomir@307:             dstIndex += VarType.isCategory2(varType) ? 2 : 1;
lubomir@307:         }
lubomir@307:     }
lubomir@307: 
lubomir@307:     private static void updateRecord(final TypeArray typeRecords,
lubomir@307:                                      final int index, final int type) {
lubomir@307:         if (typeRecords.getSize() < (index + 1)) {
lubomir@307:             typeRecords.setSize(index + 1);
lubomir@307:         }
lubomir@307: 
lubomir@307:         final int oldRecordValue = typeRecords.get(index);
lubomir@307:         final int usedTypesMask =
lubomir@307:                 (oldRecordValue >> 8) | (1 << type);
lubomir@307:         typeRecords.set(index, (usedTypesMask << 8) | type);
lubomir@307:     }
lubomir@307: 
lubomir@307:     private static Variable getVariable(final TypeArray typeRecords,
lubomir@307:                                         final int index) {
lubomir@307:         return Variable.getLocalVariable(typeRecords.get(index) & 0xff, index);
lubomir@307:     }
lubomir@307: }