| /* |
| * Copyright (c) 2012, 2016, 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 org.graalvm.compiler.core.common.type; |
| |
| import java.util.AbstractList; |
| import java.util.Objects; |
| import java.util.RandomAccess; |
| |
| import jdk.vm.ci.meta.Constant; |
| import jdk.vm.ci.meta.JavaConstant; |
| import jdk.vm.ci.meta.JavaKind; |
| import jdk.vm.ci.meta.MetaAccessProvider; |
| import jdk.vm.ci.meta.ResolvedJavaType; |
| |
| /** |
| * Type describing all pointers to Java objects. |
| */ |
| public abstract class AbstractObjectStamp extends AbstractPointerStamp { |
| |
| private final ResolvedJavaType type; |
| private final boolean exactType; |
| |
| protected AbstractObjectStamp(ResolvedJavaType type, boolean exactType, boolean nonNull, boolean alwaysNull) { |
| super(nonNull, alwaysNull); |
| this.type = type; |
| this.exactType = exactType; |
| } |
| |
| protected abstract AbstractObjectStamp copyWith(ResolvedJavaType newType, boolean newExactType, boolean newNonNull, boolean newAlwaysNull); |
| |
| @Override |
| protected final AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull) { |
| return copyWith(type, exactType, newNonNull, newAlwaysNull); |
| } |
| |
| @Override |
| public Stamp unrestricted() { |
| return copyWith(null, false, false, false); |
| } |
| |
| @Override |
| public Stamp empty() { |
| return copyWith(null, true, true, false); |
| } |
| |
| @Override |
| public Stamp constant(Constant c, MetaAccessProvider meta) { |
| JavaConstant jc = (JavaConstant) c; |
| ResolvedJavaType constType = jc.isNull() ? null : meta.lookupJavaType(jc); |
| return copyWith(constType, jc.isNonNull(), jc.isNonNull(), jc.isNull()); |
| } |
| |
| @Override |
| public boolean hasValues() { |
| return !exactType || (type != null && (isConcreteType(type))); |
| } |
| |
| @Override |
| public JavaKind getStackKind() { |
| return JavaKind.Object; |
| } |
| |
| @Override |
| public ResolvedJavaType javaType(MetaAccessProvider metaAccess) { |
| if (type != null) { |
| return type; |
| } |
| return metaAccess.lookupJavaType(Object.class); |
| } |
| |
| public ResolvedJavaType type() { |
| return type; |
| } |
| |
| public boolean isExactType() { |
| return exactType && type != null; |
| } |
| |
| protected void appendString(StringBuilder str) { |
| if (this.isEmpty()) { |
| str.append(" empty"); |
| } else { |
| str.append(nonNull() ? "!" : "").append(exactType ? "#" : "").append(' ').append(type == null ? "-" : type.getName()).append(alwaysNull() ? " NULL" : ""); |
| } |
| } |
| |
| @Override |
| public Stamp meet(Stamp otherStamp) { |
| if (this == otherStamp) { |
| return this; |
| } |
| AbstractObjectStamp other = (AbstractObjectStamp) otherStamp; |
| if (isEmpty()) { |
| return other; |
| } else if (other.isEmpty()) { |
| return this; |
| } |
| ResolvedJavaType meetType; |
| boolean meetExactType; |
| boolean meetNonNull; |
| boolean meetAlwaysNull; |
| if (other.alwaysNull()) { |
| meetType = type(); |
| meetExactType = exactType; |
| meetNonNull = false; |
| meetAlwaysNull = alwaysNull(); |
| } else if (alwaysNull()) { |
| meetType = other.type(); |
| meetExactType = other.exactType; |
| meetNonNull = false; |
| meetAlwaysNull = other.alwaysNull(); |
| } else { |
| meetType = meetTypes(type(), other.type()); |
| meetExactType = exactType && other.exactType; |
| if (meetExactType && type != null && other.type != null) { |
| // meeting two valid exact types may result in a non-exact type |
| meetExactType = Objects.equals(meetType, type) && Objects.equals(meetType, other.type); |
| } |
| meetNonNull = nonNull() && other.nonNull(); |
| meetAlwaysNull = false; |
| } |
| |
| if (Objects.equals(meetType, type) && meetExactType == exactType && meetNonNull == nonNull() && meetAlwaysNull == alwaysNull()) { |
| return this; |
| } else if (Objects.equals(meetType, other.type) && meetExactType == other.exactType && meetNonNull == other.nonNull() && meetAlwaysNull == other.alwaysNull()) { |
| return other; |
| } else { |
| return copyWith(meetType, meetExactType, meetNonNull, meetAlwaysNull); |
| } |
| } |
| |
| @Override |
| public Stamp join(Stamp otherStamp) { |
| return join0(otherStamp, false); |
| } |
| |
| /** |
| * Returns the stamp representing the type of this stamp after a cast to the type represented by |
| * the {@code to} stamp. While this is very similar to a {@link #join} operation, in the case |
| * where both types are not obviously related, the cast operation will prefer the type of the |
| * {@code to} stamp. This is necessary as long as ObjectStamps are not able to accurately |
| * represent intersection types. |
| * |
| * For example when joining the {@link RandomAccess} type with the {@link AbstractList} type, |
| * without intersection types, this would result in the most generic type ({@link Object} ). For |
| * this reason, in some cases a {@code castTo} operation is preferable in order to keep at least |
| * the {@link AbstractList} type. |
| * |
| * @param other the stamp this stamp should be casted to |
| * @return the new improved stamp or {@code null} if this stamp cannot be improved |
| */ |
| @Override |
| public Stamp improveWith(Stamp other) { |
| return join0(other, true); |
| } |
| |
| private Stamp join0(Stamp otherStamp, boolean improve) { |
| if (this == otherStamp) { |
| return this; |
| } |
| AbstractObjectStamp other = (AbstractObjectStamp) otherStamp; |
| if (isEmpty()) { |
| return this; |
| } else if (other.isEmpty()) { |
| return other; |
| } |
| |
| ResolvedJavaType joinType; |
| boolean joinAlwaysNull = alwaysNull() || other.alwaysNull(); |
| boolean joinNonNull = nonNull() || other.nonNull(); |
| boolean joinExactType = exactType || other.exactType; |
| if (Objects.equals(type, other.type)) { |
| joinType = type; |
| } else if (type == null && other.type == null) { |
| joinType = null; |
| } else if (type == null) { |
| joinType = other.type; |
| } else if (other.type == null) { |
| joinType = type; |
| } else { |
| // both types are != null and different |
| if (type.isAssignableFrom(other.type)) { |
| joinType = other.type; |
| if (exactType) { |
| joinAlwaysNull = true; |
| } |
| } else if (other.type.isAssignableFrom(type)) { |
| joinType = type; |
| if (other.exactType) { |
| joinAlwaysNull = true; |
| } |
| } else { |
| if (improve) { |
| joinType = type; |
| joinExactType = exactType; |
| } else { |
| joinType = null; |
| } |
| |
| if (joinExactType || (!isInterfaceOrArrayOfInterface(type) && !isInterfaceOrArrayOfInterface(other.type))) { |
| joinAlwaysNull = true; |
| } |
| } |
| } |
| if (joinAlwaysNull) { |
| joinType = null; |
| joinExactType = false; |
| } |
| if (joinExactType && joinType == null) { |
| return empty(); |
| } |
| if (joinAlwaysNull && joinNonNull) { |
| return empty(); |
| } else if (joinExactType && !isConcreteType(joinType)) { |
| return empty(); |
| } |
| if (Objects.equals(joinType, type) && joinExactType == exactType && joinNonNull == nonNull() && joinAlwaysNull == alwaysNull()) { |
| return this; |
| } else if (Objects.equals(joinType, other.type) && joinExactType == other.exactType && joinNonNull == other.nonNull() && joinAlwaysNull == other.alwaysNull()) { |
| return other; |
| } else { |
| return copyWith(joinType, joinExactType, joinNonNull, joinAlwaysNull); |
| } |
| } |
| |
| private static boolean isInterfaceOrArrayOfInterface(ResolvedJavaType t) { |
| return t.isInterface() || (t.isArray() && t.getElementalType().isInterface()); |
| } |
| |
| public static boolean isConcreteType(ResolvedJavaType type) { |
| return !(type.isAbstract() && !type.isArray()); |
| } |
| |
| private static ResolvedJavaType meetTypes(ResolvedJavaType a, ResolvedJavaType b) { |
| if (Objects.equals(a, b)) { |
| return a; |
| } else if (a == null || b == null) { |
| return null; |
| } else { |
| // The `meetTypes` operation must be commutative. One way to achieve this is to totally |
| // order the types and always call `meetOrderedNonNullTypes` in the same order. We |
| // establish the order by first comparing the hash-codes for performance reasons, and |
| // then comparing the internal names of the types. |
| int hashA = a.getName().hashCode(); |
| int hashB = b.getName().hashCode(); |
| if (hashA < hashB) { |
| return meetOrderedNonNullTypes(a, b); |
| } else if (hashB < hashA) { |
| return meetOrderedNonNullTypes(b, a); |
| } else { |
| int diff = a.getName().compareTo(b.getName()); |
| if (diff <= 0) { |
| return meetOrderedNonNullTypes(a, b); |
| } else { |
| return meetOrderedNonNullTypes(b, a); |
| } |
| } |
| } |
| } |
| |
| private static ResolvedJavaType meetOrderedNonNullTypes(ResolvedJavaType a, ResolvedJavaType b) { |
| ResolvedJavaType result = a.findLeastCommonAncestor(b); |
| if (result.isJavaLangObject() && a.isInterface() && b.isInterface()) { |
| // Both types are incompatible interfaces => search for first possible common |
| // ancestor match among super interfaces. |
| ResolvedJavaType[] interfacesA = a.getInterfaces(); |
| ResolvedJavaType[] interfacesB = b.getInterfaces(); |
| for (int i = 0; i < interfacesA.length; ++i) { |
| ResolvedJavaType interface1 = interfacesA[i]; |
| for (int j = 0; j < interfacesB.length; ++j) { |
| ResolvedJavaType interface2 = interfacesB[j]; |
| ResolvedJavaType leastCommon = meetTypes(interface1, interface2); |
| if (leastCommon.isInterface()) { |
| return leastCommon; |
| } |
| } |
| } |
| } |
| return result; |
| } |
| |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + super.hashCode(); |
| result = prime * result + (exactType ? 1231 : 1237); |
| result = prime * result + ((type == null || type.isJavaLangObject()) ? 0 : type.hashCode()); |
| return result; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) { |
| return true; |
| } |
| if (obj == null || getClass() != obj.getClass()) { |
| return false; |
| } |
| AbstractObjectStamp other = (AbstractObjectStamp) obj; |
| if (exactType != other.exactType) { |
| return false; |
| } |
| // null == java.lang.Object |
| if (type == null) { |
| if (other.type != null && !other.type.isJavaLangObject()) { |
| return false; |
| } |
| } else if (other.type == null) { |
| if (type != null && !type.isJavaLangObject()) { |
| return false; |
| } |
| } else if (!type.equals(other.type)) { |
| return false; |
| } |
| return super.equals(other); |
| } |
| } |
