hotspot/src/jdk.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedJavaFieldImpl.java
/*
* Copyright (c) 2011, 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.hotspot;
import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import jdk.vm.ci.common.JVMCIError;
import jdk.vm.ci.meta.JavaType;
import jdk.vm.ci.meta.LocationIdentity;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ModifiersProvider;
import jdk.vm.ci.meta.ResolvedJavaField;
import jdk.vm.ci.meta.ResolvedJavaType;
import jdk.vm.ci.options.Option;
import jdk.vm.ci.options.OptionType;
import jdk.vm.ci.options.OptionValue;
/**
* Represents a field in a HotSpot type.
*/
class HotSpotResolvedJavaFieldImpl implements HotSpotResolvedJavaField, HotSpotProxified {
static class Options {
//@formatter:off
@Option(help = "Mark well-known stable fields as such.", type = OptionType.Debug)
public static final OptionValue<Boolean> ImplicitStableValues = new OptionValue<>(true);
//@formatter:on
}
private final HotSpotResolvedObjectTypeImpl holder;
private final String name;
private JavaType type;
private final int offset;
/**
* This value contains all flags as stored in the VM including internal ones.
*/
private final int modifiers;
private final LocationIdentity locationIdentity = new FieldLocationIdentity(this);
public static class FieldLocationIdentity extends LocationIdentity {
HotSpotResolvedJavaField inner;
public FieldLocationIdentity(HotSpotResolvedJavaFieldImpl inner) {
this.inner = inner;
}
@Override
public boolean isImmutable() {
return false;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof FieldLocationIdentity) {
FieldLocationIdentity fieldLocationIdentity = (FieldLocationIdentity) obj;
return inner.equals(fieldLocationIdentity.inner);
}
return false;
}
@Override
public int hashCode() {
return inner.hashCode();
}
@Override
public String toString() {
return inner.getName();
}
}
HotSpotResolvedJavaFieldImpl(HotSpotResolvedObjectTypeImpl holder, String name, JavaType type, long offset, int modifiers) {
this.holder = holder;
this.name = name;
this.type = type;
assert offset != -1;
assert offset == (int) offset : "offset larger than int";
this.offset = (int) offset;
this.modifiers = modifiers;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof HotSpotResolvedJavaField) {
HotSpotResolvedJavaFieldImpl that = (HotSpotResolvedJavaFieldImpl) obj;
if (that.offset != this.offset || that.isStatic() != this.isStatic()) {
return false;
} else if (this.holder.equals(that.holder)) {
assert this.name.equals(that.name) && this.type.equals(that.type);
return true;
}
}
return false;
}
@Override
public int hashCode() {
return name.hashCode();
}
@Override
public int getModifiers() {
return modifiers & ModifiersProvider.jvmFieldModifiers();
}
@Override
public boolean isInternal() {
return (modifiers & config().jvmAccFieldInternal) != 0;
}
/**
* Determines if a given object contains this field.
*
* @return true iff this is a non-static field and its declaring class is assignable from
* {@code object}'s class
*/
public boolean isInObject(Object object) {
if (isStatic()) {
return false;
}
return getDeclaringClass().isAssignableFrom(HotSpotResolvedObjectTypeImpl.fromObjectClass(object.getClass()));
}
@Override
public HotSpotResolvedObjectTypeImpl getDeclaringClass() {
return holder;
}
@Override
public String getName() {
return name;
}
@Override
public JavaType getType() {
// Pull field into local variable to prevent a race causing
// a ClassCastException below
JavaType currentType = type;
if (currentType instanceof HotSpotUnresolvedJavaType) {
// Don't allow unresolved types to hang around forever
HotSpotUnresolvedJavaType unresolvedType = (HotSpotUnresolvedJavaType) currentType;
ResolvedJavaType resolved = unresolvedType.reresolve(holder);
if (resolved != null) {
type = resolved;
}
}
return type;
}
public int offset() {
return offset;
}
@Override
public String toString() {
return format("HotSpotField<%H.%n %t:") + offset + ">";
}
@Override
public boolean isSynthetic() {
return (config().jvmAccSynthetic & modifiers) != 0;
}
/**
* Checks if this field has the {@link Stable} annotation.
*
* @return true if field has {@link Stable} annotation, false otherwise
*/
public boolean isStable() {
if ((config().jvmAccFieldStable & modifiers) != 0) {
return true;
}
assert getAnnotation(Stable.class) == null;
if (Options.ImplicitStableValues.getValue() && isImplicitStableField()) {
return true;
}
return false;
}
@Override
public Annotation[] getAnnotations() {
Field javaField = toJava();
if (javaField != null) {
return javaField.getAnnotations();
}
return new Annotation[0];
}
@Override
public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
Field javaField = toJava();
if (javaField != null) {
return javaField.getAnnotation(annotationClass);
}
return null;
}
private Field toJavaCache;
private Field toJava() {
if (toJavaCache != null) {
return toJavaCache;
}
if (isInternal()) {
return null;
}
try {
return toJavaCache = holder.mirror().getDeclaredField(name);
} catch (NoSuchFieldException | NoClassDefFoundError e) {
return null;
}
}
private boolean isArray() {
JavaType fieldType = getType();
return fieldType instanceof ResolvedJavaType && ((ResolvedJavaType) fieldType).isArray();
}
private boolean isImplicitStableField() {
if (isSyntheticEnumSwitchMap()) {
return true;
}
if (isWellKnownImplicitStableField()) {
return true;
}
return false;
}
public boolean isDefaultStable() {
assert this.isStable();
if (isSyntheticEnumSwitchMap()) {
return true;
}
return false;
}
private boolean isSyntheticEnumSwitchMap() {
if (isSynthetic() && isStatic() && isArray()) {
if (isFinal() && name.equals("$VALUES") || name.equals("ENUM$VALUES")) {
// generated int[] field for EnumClass::values()
return true;
} else if (name.startsWith("$SwitchMap$") || name.startsWith("$SWITCH_TABLE$")) {
// javac and ecj generate a static field in an inner class for a switch on an enum
// named $SwitchMap$p$k$g$EnumClass and $SWITCH_TABLE$p$k$g$EnumClass, respectively
return true;
}
}
return false;
}
private boolean isWellKnownImplicitStableField() {
return WellKnownImplicitStableField.test(this);
}
static class WellKnownImplicitStableField {
/**
* @return {@code true} if the field is a well-known stable field.
*/
public static boolean test(HotSpotResolvedJavaField field) {
return field.equals(STRING_VALUE_FIELD);
}
private static final ResolvedJavaField STRING_VALUE_FIELD;
static {
try {
MetaAccessProvider metaAccess = runtime().getHostJVMCIBackend().getMetaAccess();
STRING_VALUE_FIELD = metaAccess.lookupJavaField(String.class.getDeclaredField("value"));
} catch (SecurityException | NoSuchFieldException e) {
throw new JVMCIError(e);
}
}
}
public LocationIdentity getLocationIdentity() {
return locationIdentity;
}
}