/* |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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/* |
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* This file is available under and governed by the GNU General Public |
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* License version 2 only, as published by the Free Software Foundation. |
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* However, the following notice accompanied the original version of this |
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* file: |
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* |
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* ASM: a very small and fast Java bytecode manipulation framework |
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* Copyright (c) 2000-2011 INRIA, France Telecom |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* 3. Neither the name of the copyright holders nor the names of its |
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* contributors may be used to endorse or promote products derived from |
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* this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
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* THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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package jdk.internal.org.objectweb.asm; |
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/** |
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* Information about an exception handler. Corresponds to an element of the exception_table array of |
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* a Code attribute, as defined in the Java Virtual Machine Specification (JVMS). Handler instances |
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* can be chained together, with their {@link #nextHandler} field, to describe a full JVMS |
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* exception_table array. |
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* |
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* @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.3">JVMS |
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* 4.7.3</a> |
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* @author Eric Bruneton |
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*/ |
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final class Handler { |
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/** |
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* The start_pc field of this JVMS exception_table entry. Corresponds to the beginning of the |
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* exception handler's scope (inclusive). |
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*/ |
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final Label startPc; |
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/** |
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* The end_pc field of this JVMS exception_table entry. Corresponds to the end of the exception |
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* handler's scope (exclusive). |
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*/ |
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final Label endPc; |
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/** |
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* The handler_pc field of this JVMS exception_table entry. Corresponding to the beginning of the |
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* exception handler's code. |
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*/ |
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final Label handlerPc; |
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/** |
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* The catch_type field of this JVMS exception_table entry. This is the constant pool index of the |
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* internal name of the type of exceptions handled by this handler, or 0 to catch any exceptions. |
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*/ |
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final int catchType; |
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/** |
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* The internal name of the type of exceptions handled by this handler, or {@literal null} to |
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* catch any exceptions. |
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*/ |
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final String catchTypeDescriptor; |
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/** The next exception handler. */ |
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Handler nextHandler; |
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/** |
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* Constructs a new Handler. |
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* |
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* @param startPc the start_pc field of this JVMS exception_table entry. |
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* @param endPc the end_pc field of this JVMS exception_table entry. |
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* @param handlerPc the handler_pc field of this JVMS exception_table entry. |
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* @param catchType The catch_type field of this JVMS exception_table entry. |
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* @param catchTypeDescriptor The internal name of the type of exceptions handled by this handler, |
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* or {@literal null} to catch any exceptions. |
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*/ |
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Handler( |
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final Label startPc, |
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final Label endPc, |
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final Label handlerPc, |
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final int catchType, |
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final String catchTypeDescriptor) { |
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this.startPc = startPc; |
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this.endPc = endPc; |
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this.handlerPc = handlerPc; |
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this.catchType = catchType; |
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this.catchTypeDescriptor = catchTypeDescriptor; |
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} |
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/** |
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* Constructs a new Handler from the given one, with a different scope. |
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* |
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* @param handler an existing Handler. |
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* @param startPc the start_pc field of this JVMS exception_table entry. |
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* @param endPc the end_pc field of this JVMS exception_table entry. |
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*/ |
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Handler(final Handler handler, final Label startPc, final Label endPc) { |
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this(startPc, endPc, handler.handlerPc, handler.catchType, handler.catchTypeDescriptor); |
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this.nextHandler = handler.nextHandler; |
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} |
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/** |
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* Removes the range between start and end from the Handler list that begins with the given |
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* element. |
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* |
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* @param firstHandler the beginning of a Handler list. May be {@literal null}. |
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* @param start the start of the range to be removed. |
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* @param end the end of the range to be removed. Maybe {@literal null}. |
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* @return the exception handler list with the start-end range removed. |
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*/ |
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static Handler removeRange(final Handler firstHandler, final Label start, final Label end) { |
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if (firstHandler == null) { |
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return null; |
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} else { |
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firstHandler.nextHandler = removeRange(firstHandler.nextHandler, start, end); |
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} |
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int handlerStart = firstHandler.startPc.bytecodeOffset; |
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int handlerEnd = firstHandler.endPc.bytecodeOffset; |
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int rangeStart = start.bytecodeOffset; |
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int rangeEnd = end == null ? Integer.MAX_VALUE : end.bytecodeOffset; |
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// Return early if [handlerStart,handlerEnd[ and [rangeStart,rangeEnd[ don't intersect. |
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if (rangeStart >= handlerEnd || rangeEnd <= handlerStart) { |
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return firstHandler; |
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} |
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if (rangeStart <= handlerStart) { |
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if (rangeEnd >= handlerEnd) { |
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// If [handlerStart,handlerEnd[ is included in [rangeStart,rangeEnd[, remove firstHandler. |
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return firstHandler.nextHandler; |
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} else { |
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// [handlerStart,handlerEnd[ - [rangeStart,rangeEnd[ = [rangeEnd,handlerEnd[ |
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return new Handler(firstHandler, end, firstHandler.endPc); |
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} |
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} else if (rangeEnd >= handlerEnd) { |
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// [handlerStart,handlerEnd[ - [rangeStart,rangeEnd[ = [handlerStart,rangeStart[ |
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return new Handler(firstHandler, firstHandler.startPc, start); |
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} else { |
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// [handlerStart,handlerEnd[ - [rangeStart,rangeEnd[ = |
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// [handlerStart,rangeStart[ + [rangeEnd,handerEnd[ |
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firstHandler.nextHandler = new Handler(firstHandler, end, firstHandler.endPc); |
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return new Handler(firstHandler, firstHandler.startPc, start); |
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} |
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} |
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/** |
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* Returns the number of elements of the Handler list that begins with the given element. |
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* |
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* @param firstHandler the beginning of a Handler list. May be {@literal null}. |
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* @return the number of elements of the Handler list that begins with 'handler'. |
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*/ |
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static int getExceptionTableLength(final Handler firstHandler) { |
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int length = 0; |
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Handler handler = firstHandler; |
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while (handler != null) { |
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length++; |
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handler = handler.nextHandler; |
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} |
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return length; |
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} |
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/** |
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* Returns the size in bytes of the JVMS exception_table corresponding to the Handler list that |
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* begins with the given element. <i>This includes the exception_table_length field.</i> |
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* |
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* @param firstHandler the beginning of a Handler list. May be {@literal null}. |
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* @return the size in bytes of the exception_table_length and exception_table structures. |
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*/ |
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static int getExceptionTableSize(final Handler firstHandler) { |
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return 2 + 8 * getExceptionTableLength(firstHandler); |
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} |
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/** |
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* Puts the JVMS exception_table corresponding to the Handler list that begins with the given |
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* element. <i>This includes the exception_table_length field.</i> |
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* |
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* @param firstHandler the beginning of a Handler list. May be {@literal null}. |
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* @param output where the exception_table_length and exception_table structures must be put. |
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*/ |
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static void putExceptionTable(final Handler firstHandler, final ByteVector output) { |
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output.putShort(getExceptionTableLength(firstHandler)); |
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Handler handler = firstHandler; |
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while (handler != null) { |
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output |
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.putShort(handler.startPc.bytecodeOffset) |
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.putShort(handler.endPc.bytecodeOffset) |
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.putShort(handler.handlerPc.bytecodeOffset) |
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.putShort(handler.catchType); |
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handler = handler.nextHandler; |
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} |
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} |
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} |