/* * This file is part of the Jikes RVM project (http://jikesrvm.org). * * This file is licensed to You under the Eclipse Public License (EPL); * You may not use this file except in compliance with the License. You * may obtain a copy of the License at * * http://www.opensource.org/licenses/eclipse-1.0.php * * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. */ package org.jikesrvm.compilers.common; import org.jikesrvm.VM; import org.jikesrvm.classloader.DynamicTypeCheck; import org.jikesrvm.classloader.RVMType; import org.jikesrvm.objectmodel.TIB; import org.jikesrvm.util.Services; import org.vmmagic.pragma.Uninterruptible; import org.vmmagic.pragma.Unpreemptible; import org.vmmagic.unboxed.Offset; /** * Encoding of try ranges in the final machinecode and the * corresponding exception type and catch block start. */ public abstract class ExceptionTable { /** * An eTable array encodes the exception tables using 4 ints for each */ protected static final int TRY_START = 0; protected static final int TRY_END = 1; protected static final int CATCH_START = 2; protected static final int EX_TYPE = 3; /** * Return the machine code offset for the catch block that will handle * the argument exceptionType,or -1 if no such catch block exists. * * @param eTable the encoded exception table to search * @param instructionOffset the offset of the instruction after the PEI. * @param exceptionType the type of exception that was raised * @return the machine code offset of the catch block. */ @Unpreemptible public static int findCatchBlockForInstruction(int[] eTable, Offset instructionOffset, RVMType exceptionType) { for (int i = 0, n = eTable.length; i < n; i += 4) { // note that instructionOffset points to the instruction after the PEI // so the range check here must be "offset > beg && offset <= end" // and not "offset >= beg && offset < end" // // offset starts are sorted by starting point if (instructionOffset.sGT(Offset.fromIntSignExtend(eTable[i + TRY_START])) && instructionOffset.sLE(Offset.fromIntSignExtend(eTable[i + TRY_END]))) { RVMType lhs = RVMType.getType(eTable[i + EX_TYPE]); if (lhs == exceptionType) { return eTable[i + CATCH_START]; } else if (lhs.isInitialized()) { TIB rhsTIB = exceptionType.getTypeInformationBlock(); if (DynamicTypeCheck.instanceOfClass(lhs.asClass(), rhsTIB)) { return eTable[i + CATCH_START]; } } } } return -1; } /** * Print an encoded exception table. * @param eTable the encoded exception table to print. */ public static void printExceptionTable(int[] eTable) { writeExceptionTableHeader(); int length = eTable.length; for (int i = 0; i < length; i += 4) { printNicelyFormattedAndInterruptible(eTable, i); } } @Uninterruptible private static void writeExceptionTableHeader() { VM.sysWriteln("Exception Table:"); VM.sysWriteln(" trystart tryend catch type"); } private static void printNicelyFormattedAndInterruptible(int[] eTable, int i) { VM.sysWriteln(" " + Services.getHexString(eTable[i + TRY_START], true) + " " + Services.getHexString(eTable[i + TRY_END], true) + " " + Services.getHexString(eTable[i + CATCH_START], true) + " " + RVMType.getType(eTable[i + EX_TYPE])); } /** * Prints an exception table. * <p> * This method does the same thing as {@link #printExceptionTable(int[])} but * with less nicely formatted output because of the constraints imposed by * the requirements for uninterruptible code. * * @param eTable the exception table to print */ @Uninterruptible public static void printExceptionTableUninterruptible(int[] eTable) { writeExceptionTableHeader(); int length = eTable.length; for (int i = 0; i < length; i += 4) { printLessNicelyFormattedAndUninterruptible(eTable, i); } } @Uninterruptible private static void printLessNicelyFormattedAndUninterruptible(int[] eTable, int i) { VM.sysWrite(" "); VM.sysWriteHex(eTable[i + TRY_START]); VM.sysWrite(" "); VM.sysWriteHex(eTable[i + TRY_END]); VM.sysWrite(" "); VM.sysWriteHex(eTable[i + CATCH_START]); VM.sysWrite(" "); VM.sysWrite(RVMType.getType(eTable[i + EX_TYPE]).getDescriptor()); VM.sysWriteln(); } }