lubomir@221: /*
lubomir@221:  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
lubomir@221:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
lubomir@221:  *
lubomir@221:  * This code is free software; you can redistribute it and/or modify it
lubomir@221:  * under the terms of the GNU General Public License version 2 only, as
lubomir@221:  * published by the Free Software Foundation.  Oracle designates this
lubomir@221:  * particular file as subject to the "Classpath" exception as provided
lubomir@221:  * by Oracle in the LICENSE file that accompanied this code.
lubomir@221:  *
lubomir@221:  * This code is distributed in the hope that it will be useful, but WITHOUT
lubomir@221:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
lubomir@221:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
lubomir@221:  * version 2 for more details (a copy is included in the LICENSE file that
lubomir@221:  * accompanied this code).
lubomir@221:  *
lubomir@221:  * You should have received a copy of the GNU General Public License version
lubomir@221:  * 2 along with this work; if not, write to the Free Software Foundation,
lubomir@221:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
lubomir@221:  *
lubomir@221:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
lubomir@221:  * or visit www.oracle.com if you need additional information or have any
lubomir@221:  * questions.
lubomir@221:  */
lubomir@221: 
lubomir@221: package org.apidesign.javap;
lubomir@221: 
lubomir@307: import static org.apidesign.javap.RuntimeConstants.ITEM_Integer;
lubomir@307: import static org.apidesign.javap.RuntimeConstants.ITEM_Float;
lubomir@307: import static org.apidesign.javap.RuntimeConstants.ITEM_Double;
lubomir@307: import static org.apidesign.javap.RuntimeConstants.ITEM_Long;
lubomir@307: import static org.apidesign.javap.RuntimeConstants.ITEM_Object;
lubomir@307: 
lubomir@221: public final class StackMapIterator {
lubomir@221:     private final StackMapTableData[] stackMapTable;
lubomir@307:     private final TypeArray argTypes;
lubomir@281:     private final TypeArray localTypes;
lubomir@281:     private final TypeArray stackTypes;
lubomir@221: 
lubomir@221:     private int nextFrameIndex;
lubomir@221:     private int lastFrameByteCodeOffset;
lubomir@221: 
lubomir@221:     private int byteCodeOffset;
lubomir@221: 
lubomir@307:     StackMapIterator(final MethodData methodData) {
lubomir@307:         this(methodData.getStackMapTable(),
lubomir@307:              methodData.getInternalSig(),
lubomir@307:              methodData.isStatic());
lubomir@307:     }
lubomir@307: 
lubomir@307:     StackMapIterator(final StackMapTableData[] stackMapTable,
lubomir@307:                      final String methodSignature,
lubomir@307:                      final boolean isStaticMethod) {
lubomir@221:         this.stackMapTable = (stackMapTable != null)
lubomir@221:                                  ? stackMapTable
lubomir@221:                                  : new StackMapTableData[0];
lubomir@281: 
lubomir@307:         argTypes = getArgTypes(methodSignature, isStaticMethod);
lubomir@281:         localTypes = new TypeArray();
lubomir@281:         stackTypes = new TypeArray();
lubomir@307: 
lubomir@307:         localTypes.addAll(argTypes);
lubomir@307: 
lubomir@281:         lastFrameByteCodeOffset = -1;
lubomir@221:         advanceBy(0);
lubomir@221:     }
lubomir@221: 
lubomir@221:     public String getFrameAsString() {
lubomir@307:         return (nextFrameIndex == 0)
lubomir@307:                    ? StackMapTableData.toString("INITIAL", 0, null, null)
lubomir@307:                    : stackMapTable[nextFrameIndex - 1].toString();
lubomir@221:     }
lubomir@221: 
lubomir@221:     public int getFrameIndex() {
lubomir@221:         return nextFrameIndex;
lubomir@221:     }
lubomir@221: 
lubomir@281:     public TypeArray getFrameStack() {
lubomir@281:         return stackTypes;
lubomir@221:     }
lubomir@221: 
lubomir@307:     public TypeArray getFrameLocals() {
lubomir@307:         return localTypes;
lubomir@307:     }
lubomir@307: 
lubomir@307:     public TypeArray getArguments() {
lubomir@307:         return argTypes;
lubomir@307:     }
lubomir@307: 
lubomir@221:     public void advanceBy(final int numByteCodes) {
lubomir@221:         if (numByteCodes < 0) {
lubomir@221:             throw new IllegalStateException("Forward only iterator");
lubomir@221:         }
lubomir@221: 
lubomir@221:         byteCodeOffset += numByteCodes;
lubomir@221:         while ((nextFrameIndex < stackMapTable.length)
lubomir@221:                     && ((byteCodeOffset - lastFrameByteCodeOffset)
lubomir@221:                             >= (stackMapTable[nextFrameIndex].offsetDelta
lubomir@221:                                     + 1))) {
lubomir@281:             final StackMapTableData nextFrame = stackMapTable[nextFrameIndex];
lubomir@281: 
lubomir@281:             lastFrameByteCodeOffset += nextFrame.offsetDelta + 1;
lubomir@281:             nextFrame.applyTo(localTypes, stackTypes);
lubomir@281: 
lubomir@221:             ++nextFrameIndex;
lubomir@221:         }
lubomir@221:     }
lubomir@221: 
lubomir@221:     public void advanceTo(final int nextByteCodeOffset) {
lubomir@221:         advanceBy(nextByteCodeOffset - byteCodeOffset);
lubomir@221:     }
lubomir@221: 
lubomir@307:     private static TypeArray getArgTypes(final String methodSignature,
lubomir@307:                                          final boolean isStaticMethod) {
lubomir@307:         final TypeArray argTypes = new TypeArray();
lubomir@307: 
lubomir@307:         if (!isStaticMethod) {
lubomir@307:             argTypes.add(ITEM_Object);
lubomir@307:         }
lubomir@307: 
lubomir@307:         if (methodSignature.charAt(0) != '(') {
lubomir@307:             throw new IllegalArgumentException("Invalid method signature");
lubomir@307:         }
lubomir@307: 
lubomir@307:         final int length = methodSignature.length();
lubomir@472:         boolean skipType = false;
lubomir@307:         int argType;
lubomir@307:         for (int i = 1; i < length; ++i) {
lubomir@307:             switch (methodSignature.charAt(i)) {
lubomir@307:                 case 'B':
lubomir@307:                 case 'C':
lubomir@307:                 case 'S':
lubomir@307:                 case 'Z':
lubomir@307:                 case 'I':
lubomir@307:                     argType = ITEM_Integer;
lubomir@307:                     break;
lubomir@307:                 case 'J':
lubomir@307:                     argType = ITEM_Long;
lubomir@307:                     break;
lubomir@307:                 case 'F':
lubomir@307:                     argType = ITEM_Float;
lubomir@307:                     break;
lubomir@307:                 case 'D':
lubomir@307:                     argType = ITEM_Double;
lubomir@307:                     break;
lubomir@307:                 case 'L': {
lubomir@307:                     i = methodSignature.indexOf(';', i + 1);
lubomir@307:                     if (i == -1) {
lubomir@307:                         throw new IllegalArgumentException(
lubomir@307:                                       "Invalid method signature");
lubomir@307:                     }
lubomir@307:                     argType = ITEM_Object;
lubomir@307:                     break;
lubomir@307:                 }
lubomir@307:                 case ')':
lubomir@307:                     // not interested in the return value type
lubomir@307:                     return argTypes;
lubomir@307:                 case '[':
lubomir@472:                     if (!skipType) {
lubomir@307:                         argTypes.add(ITEM_Object);
lubomir@472:                         skipType = true;
lubomir@307:                     }
lubomir@307:                     continue;
lubomir@307: 
lubomir@307:                 default:
lubomir@307:                     throw new IllegalArgumentException(
lubomir@307:                                   "Invalid method signature");
lubomir@307:             }
lubomir@307: 
lubomir@472:             if (!skipType) {
lubomir@307:                 argTypes.add(argType);
lubomir@307:             } else {
lubomir@472:                 skipType = false;
lubomir@307:             }
lubomir@307:         }
lubomir@307: 
lubomir@307:         return argTypes;
lubomir@221:     }
lubomir@221: }