Mercurial > hg > graal-jvmci-8
view jvmci/jdk.vm.ci.code/src/jdk/vm/ci/code/BytecodeFrame.java @ 23320:d9ae6a4319be
add support for MX_ALT_OUTPUT_ROOT
author | Doug Simon <doug.simon@oracle.com> |
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date | Fri, 11 Mar 2016 16:53:36 +0100 |
parents | 1bbd4a7c274b |
children | 1d4ce2d19e52 |
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/* * Copyright (c) 2009, 2015, 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 jdk.vm.ci.code; import java.util.Arrays; import jdk.vm.ci.meta.JavaKind; import jdk.vm.ci.meta.JavaValue; import jdk.vm.ci.meta.ResolvedJavaMethod; import jdk.vm.ci.meta.Value; /** * Represents the Java bytecode frame state(s) at a given position including {@link Value locations} * where to find the local variables, operand stack values and locked objects of the bytecode * frame(s). */ public class BytecodeFrame extends BytecodePosition { /** * An array of values representing how to reconstruct the state of the Java frame. This is array * is partitioned as follows: * <p> * <table summary="" border="1" cellpadding="5" frame="void" rules="all"> * <tr> * <th>Start index (inclusive)</th> * <th>End index (exclusive)</th> * <th>Description</th> * </tr> * <tr> * <td>0</td> * <td>numLocals</td> * <td>Local variables</td> * </tr> * <tr> * <td>numLocals</td> * <td>numLocals + numStack</td> * <td>Operand stack</td> * </tr> * <tr> * <td>numLocals + numStack</td> * <td>values.length</td> * <td>Locked objects</td> * </tr> * </table> * <p> * Note that the number of locals and the number of stack slots may be smaller than the maximum * number of locals and stack slots as specified in the compiled method. */ public final JavaValue[] values; /** * An array describing the Java kind of the {@link #values}. It records a kind for the locals * and the operand stack. */ public final JavaKind[] slotKinds; /** * The number of locals in the values array. */ public final int numLocals; /** * The number of stack slots in the values array. */ public final int numStack; /** * The number of locks in the values array. */ public final int numLocks; /** * True if this is a position inside an exception handler before the exception object has been * consumed. In this case, {@link #numStack} {@code == 1} and {@link #getStackValue(int) * getStackValue(0)} is the location of the exception object. If deoptimization happens at this * position, the interpreter will rethrow the exception instead of executing the bytecode * instruction at this position. */ public final boolean rethrowException; public final boolean duringCall; /** * This BCI should be used for frame states that are built for code with no meaningful BCI. */ public static final int UNKNOWN_BCI = -5; /** * The BCI for exception unwind. This is synthetic code and has no representation in bytecode. * In contrast with {@link #AFTER_EXCEPTION_BCI}, at this point, if the method is synchronized, * the monitor is still held. */ public static final int UNWIND_BCI = -1; /** * The BCI for the state before starting to execute a method. Note that if the method is * synchronized, the monitor is not yet held. */ public static final int BEFORE_BCI = -2; /** * The BCI for the state after finishing the execution of a method and returning normally. Note * that if the method was synchronized the monitor is already released. */ public static final int AFTER_BCI = -3; /** * The BCI for exception unwind. This is synthetic code and has no representation in bytecode. * In contrast with {@link #UNWIND_BCI}, at this point, if the method is synchronized, the * monitor is already released. */ public static final int AFTER_EXCEPTION_BCI = -4; /** * This BCI should be used for states that cannot be the target of a deoptimization, like * snippet frame states. */ public static final int INVALID_FRAMESTATE_BCI = -6; /** * Determines if a given BCI matches one of the placeholder BCI constants defined in this class. */ public static boolean isPlaceholderBci(int bci) { return bci < 0; } /** * Gets the name of a given placeholder BCI. */ public static String getPlaceholderBciName(int bci) { assert isPlaceholderBci(bci); if (bci == BytecodeFrame.AFTER_BCI) { return "AFTER_BCI"; } else if (bci == BytecodeFrame.AFTER_EXCEPTION_BCI) { return "AFTER_EXCEPTION_BCI"; } else if (bci == BytecodeFrame.INVALID_FRAMESTATE_BCI) { return "INVALID_FRAMESTATE_BCI"; } else if (bci == BytecodeFrame.BEFORE_BCI) { return "BEFORE_BCI"; } else if (bci == BytecodeFrame.UNKNOWN_BCI) { return "UNKNOWN_BCI"; } else { assert bci == BytecodeFrame.UNWIND_BCI; return "UNWIND_BCI"; } } /** * Creates a new frame object. * * @param caller the caller frame (which may be {@code null}) * @param method the method * @param bci a BCI within the method * @param rethrowException specifies if the VM should re-throw the pending exception when * deopt'ing using this frame * @param values the frame state {@link #values} * @param numLocals the number of local variables * @param numStack the depth of the stack * @param numLocks the number of locked objects */ public BytecodeFrame(BytecodeFrame caller, ResolvedJavaMethod method, int bci, boolean rethrowException, boolean duringCall, JavaValue[] values, JavaKind[] slotKinds, int numLocals, int numStack, int numLocks) { super(caller, method, bci); assert values != null; this.rethrowException = rethrowException; this.duringCall = duringCall; this.values = values; this.slotKinds = slotKinds; this.numLocals = numLocals; this.numStack = numStack; this.numLocks = numLocks; assert !rethrowException || numStack == 1 : "must have exception on top of the stack"; } /** * Ensure that the frame state is formatted as expected by the JVM, with null or Illegal in the * slot following a double word item. This should really be checked in FrameState itself but * because of Word type rewriting and alternative backends that can't be done. */ public boolean validateFormat() { if (caller() != null) { caller().validateFormat(); } for (int i = 0; i < numLocals + numStack; i++) { if (values[i] != null) { JavaKind kind = slotKinds[i]; if (kind.needsTwoSlots()) { assert slotKinds.length > i + 1 : String.format("missing second word %s", this); assert slotKinds[i + 1] == JavaKind.Illegal : this; } } } return true; } /** * Gets the value representing the specified local variable. * * @param i the local variable index * @return the value that can be used to reconstruct the local's current value */ public JavaValue getLocalValue(int i) { return values[i]; } /** * Gets the value representing the specified stack slot. * * @param i the stack index * @return the value that can be used to reconstruct the stack slot's current value */ public JavaValue getStackValue(int i) { return values[i + numLocals]; } /** * Gets the value representing the specified lock. * * @param i the lock index * @return the value that can be used to reconstruct the lock's current value */ public JavaValue getLockValue(int i) { return values[i + numLocals + numStack]; } /** * Gets the caller of this frame. * * @return {@code null} if this frame has no caller */ public BytecodeFrame caller() { return (BytecodeFrame) getCaller(); } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj instanceof BytecodeFrame && super.equals(obj)) { BytecodeFrame that = (BytecodeFrame) obj; // @formatter:off if (this.duringCall == that.duringCall && this.rethrowException == that.rethrowException && this.numLocals == that.numLocals && this.numLocks == that.numLocks && this.numStack == that.numStack && Arrays.equals(this.values, that.values)) { return true; } // @formatter:off return true; } return false; } @Override public String toString() { return CodeUtil.append(new StringBuilder(100), this).toString(); } }