Mercurial > hg > graal-jvmci-8
view graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/ConstantReflectionProvider.java @ 18472:de179c27cad3
Add support for stable array constants
author | Andreas Woess <andreas.woess@jku.at> |
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date | Thu, 20 Nov 2014 13:22:12 +0100 |
parents | f0a8b72315c1 |
children | b8a622c3e99f |
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/* * Copyright (c) 2012, 2014, 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.oracle.graal.api.meta; import java.lang.invoke.*; /** * Reflection operations on values represented as {@linkplain JavaConstant constants}. All methods * in this interface require the VM to access the actual object encapsulated in {@link Kind#Object * object} constants. This access is not always possible, depending on kind of VM and the state that * the VM is in. Therefore, all methods can return {@code null} at any time, to indicate that the * result is not available at this point. The caller is responsible to check for {@code null} * results and handle them properly, e.g., not perform an optimization. */ public interface ConstantReflectionProvider extends Remote { /** * Compares two constants for equality. The equality relationship is symmetric. Returns * {@link Boolean#TRUE true} if the two constants represent the same run time value, * {@link Boolean#FALSE false} if they are different. Returns {@code null} if the constants * cannot be compared at this point. */ Boolean constantEquals(Constant x, Constant y); /** * Returns the length of the array constant. Returns {@code null} if the constant is not an * array, or if the array length is not available at this point. */ Integer readArrayLength(JavaConstant array); /** * Reads a value from the given array at the given index. Returns {@code null} if the constant * is not an array, if the index is out of bounds, or if the value is not available at this * point. */ JavaConstant readArrayElement(JavaConstant array, int index); /** * Reads a value from the given array at the given index if it is a stable array. Returns * {@code null} if the constant is not a stable array, if it is a default value, if the index is * out of bounds, or if the value is not available at this point. */ JavaConstant readConstantArrayElement(JavaConstant array, int index); /** * Gets the constant value of this field. Note that a {@code static final} field may not be * considered constant if its declaring class is not yet initialized or if it is a well known * field that can be updated via other means (e.g., {@link System#setOut(java.io.PrintStream)}). * * @param receiver object from which this field's value is to be read. This value is ignored if * this field is static. * @return the constant value of this field or {@code null} if this field is not considered * constant by the runtime */ JavaConstant readConstantFieldValue(JavaField field, JavaConstant receiver); /** * Gets the current value of this field for a given object, if available. * * There is no guarantee that the same value will be returned by this method for a field unless * the field is considered to be {@linkplain #readConstantFieldValue(JavaField, JavaConstant) * constant} by the runtime. * * @param receiver object from which this field's value is to be read. This value is ignored if * this field is static. * @return the value of this field or {@code null} if the value is not available (e.g., because * the field holder is not yet initialized). */ JavaConstant readFieldValue(JavaField field, JavaConstant receiver); /** * Gets the current value of this field for a given object, if available. Like * {@link #readFieldValue(JavaField, JavaConstant)} but treats array fields as stable. * * There is no guarantee that the same value will be returned by this method for a field unless * the field is considered to be {@linkplain #readConstantFieldValue(JavaField, JavaConstant) * constant} by the runtime. * * @param receiver object from which this field's value is to be read. This value is ignored if * this field is static. * @param isDefaultStable if {@code true}, default values are considered stable * @return the value of this field or {@code null} if the value is not available (e.g., because * the field holder is not yet initialized). */ JavaConstant readStableFieldValue(JavaField field, JavaConstant receiver, boolean isDefaultStable); /** * Reads a value of this kind using a base address and a displacement. No bounds checking or * type checking is performed. Returns {@code null} if the value is not available at this point. * * @param base the base address from which the value is read. * @param displacement the displacement within the object in bytes * @return the read value encapsulated in a {@link JavaConstant} object, or {@code null} if the * value cannot be read. */ JavaConstant readUnsafeConstant(Kind kind, JavaConstant base, long displacement); /** * Reads a primitive value using a base address and a displacement. * * @param kind the {@link Kind} of the returned {@link JavaConstant} object * @param base the base address from which the value is read * @param displacement the displacement within the object in bytes * @param bits the number of bits to read from memory * @return the read value encapsulated in a {@link Constant} object of {@link Kind} kind */ JavaConstant readRawConstant(Kind kind, Constant base, long displacement, int bits); /** * Reads a pointer value using a base address and a displacement. * * @param type the {@link PointerType} of the returned {@link Constant} object * @param base the base address from which the value is read * @param displacement the displacement within the object in bytes * @return the read value encapsulated in a {@link Constant} object */ Constant readPointerConstant(PointerType type, Constant base, long displacement); /** * Converts the given {@link Kind#isPrimitive() primitive} constant to a boxed * {@link Kind#Object object} constant, according to the Java boxing rules. Returns {@code null} * if the source is is not a primitive constant, or the boxed value is not available at this * point. */ JavaConstant boxPrimitive(JavaConstant source); /** * Converts the given {@link Kind#Object object} constant to a {@link Kind#isPrimitive() * primitive} constant, according to the Java unboxing rules. Returns {@code null} if the source * is is not an object constant that can be unboxed, or the unboxed value is not available at * this point. */ JavaConstant unboxPrimitive(JavaConstant source); /** * Gets a string as a {@link JavaConstant}. */ JavaConstant forString(String value); /** * Returns the {@link ResolvedJavaType} for a {@link Class} object (or any other object regarded * as a class by the VM) encapsulated in the given constant. Returns {@code null} if the * constant does not encapsulate a class, or if the type is not available at this point. */ ResolvedJavaType asJavaType(JavaConstant constant); /** * Gets access to the internals of {@link MethodHandle}. */ MethodHandleAccessProvider getMethodHandleAccess(); }