Mercurial > hg > truffle
view graal/GraalCompiler/src/com/sun/c1x/ir/ExceptionHandler.java @ 2634:4dd0573f510b
FrameState fixes.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
---|---|
date | Wed, 11 May 2011 10:52:37 +0200 |
parents | 46586c77b129 |
children | 4a6518c4d17d |
line wrap: on
line source
/* * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.c1x.ir; import java.util.*; import com.sun.c1x.lir.*; import com.sun.cri.ri.*; /** * The {@code ExceptionHandler} class represents an exception handler for a Java bytecode method. * There is exactly one instance of this class for every exception handler without any specific * reference to an exception-throwing instruction covered by the handler. Then there is one * instance per exception-throwing instruction that is used to record the frame state before * execution of the instruction. The latter is used to generate exception adapter blocks * (see section 3.4 of the paper <a href="http://www.usenix.org/events/vee05/full_papers/p132-wimmer.pdf"> * Optimized Interval Splitting in a Linear Scan Register Allocator</a>) where necessary. * * @author Ben L. Titzer */ public final class ExceptionHandler { public static final List<ExceptionHandler> ZERO_HANDLERS = Collections.emptyList(); public final RiExceptionHandler handler; private BlockBegin entryBlock; private LIRList entryCode; private int entryCodeOffset; private int phiOperand; private int lirOpId; public ExceptionHandler(RiExceptionHandler handler) { this.handler = handler; this.entryCodeOffset = -1; this.phiOperand = -1; this.lirOpId = -1; } public ExceptionHandler(ExceptionHandler other) { this.handler = other.handler; this.entryBlock = other.entryBlock; this.entryCode = other.entryCode; this.entryCodeOffset = other.entryCodeOffset; this.phiOperand = other.phiOperand; this.lirOpId = other.lirOpId; } @Override public String toString() { return "XHandler(Block=" + entryBlock.blockID + ") " + handler; } /** * Gets the compiler interface object that describes this exception handler, * including the bytecode ranges. * @return the compiler interface exception handler */ public RiExceptionHandler handler() { return handler; } /** * Gets the bytecode index of the handler (catch block). * @return the bytecode index of the handler */ public int handlerBCI() { return handler.handlerBCI(); } /** * Utility method to check if this exception handler covers the specified bytecode index. * @param bci the bytecode index to check * @return {@code true} if this exception handler covers the specified bytecode */ public boolean covers(int bci) { return handler.startBCI() <= bci && bci < handler.endBCI(); } /** * Gets the entry block for this exception handler. * @return the entry block */ public BlockBegin entryBlock() { return entryBlock; } /** * Gets the PC offset of the handler entrypoint, which is used by * the runtime to forward exception points to their catch sites. * @return the pc offset of the handler entrypoint */ public int entryCodeOffset() { return entryCodeOffset; } public int phiOperand() { return phiOperand; } public void setEntryBlock(BlockBegin entry) { entryBlock = entry; } public void setEntryCodeOffset(int pco) { entryCodeOffset = pco; } public void setPhiOperand(int phi) { phiOperand = phi; } public boolean isCatchAll() { return handler.catchTypeCPI() == 0; } public static boolean couldCatch(List<ExceptionHandler> exceptionHandlers, RiType klass, boolean typeIsExact) { // the type is unknown so be conservative if (!klass.isResolved()) { return true; } for (int i = 0; i < exceptionHandlers.size(); i++) { ExceptionHandler handler = exceptionHandlers.get(i); if (handler.isCatchAll()) { // catch of ANY return true; } RiType handlerKlass = handler.handler.catchType(); // if it's unknown it might be catchable if (!handlerKlass.isResolved()) { return true; } // if the throw type is definitely a subtype of the catch type // then it can be caught. if (klass.isSubtypeOf(handlerKlass)) { return true; } if (!typeIsExact) { // If the type isn't exactly known then it can also be caught by // catch statements where the inexact type is a subtype of the // catch type. // given: foo extends bar extends Exception // throw bar can be caught by catch foo, catch bar, and catch // Exception, however it can't be caught by any handlers without // bar in its type hierarchy. if (handlerKlass.isSubtypeOf(klass)) { return true; } } } return false; } public int lirOpId() { return lirOpId; } public LIRList entryCode() { return entryCode; } public void setLirOpId(int throwingOpId) { lirOpId = throwingOpId; } public void setEntryCode(LIRList entryCode) { this.entryCode = entryCode; } }