| /* |
| * Copyright (c) 2016, 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 jdk.vm.ci.meta.Assumptions; |
| import jdk.vm.ci.meta.ResolvedJavaType; |
| |
| /** |
| * This class represents a reference to a Java type and whether this reference is referring only to |
| * the represented type or also to its sub types in the class hierarchy. When creating a type |
| * reference, the following options have to be considered: |
| * |
| * <ul> |
| * <li>The reference should always only refer to the given concrete type. Use |
| * {@link #createExactTrusted(ResolvedJavaType)} for this purpose.</li> |
| * <li>The reference should be created without assumptions about the class hierarchy. The returned |
| * reference is exact only when the type is a leaf type (i.e., it cannot have subclasses). Depending |
| * on whether interface types can be trusted for this type reference use |
| * {@link #createWithoutAssumptions} or {@link #createTrustedWithoutAssumptions}.</li> |
| * <li>The reference should be created using assumptions about the class hierarchy. The returned |
| * reference is also exact, when there is only a single concrete sub type for the given type. |
| * Depending on whether interface types can be trusted for this type reference use {@link #create} |
| * or {@link #createTrusted}.</li> |
| * </ul> |
| * |
| * For the methods with untrusted interface types, a {@code null} reference will be constructed for |
| * untrusted interface types. Examples for interface types that cannot be trusted are types for |
| * parameters, fields, and return values. They are not checked by the Java verifier. |
| * |
| */ |
| public final class TypeReference { |
| private final ResolvedJavaType type; |
| private final boolean exactReference; |
| |
| private TypeReference(ResolvedJavaType type, boolean exactReference) { |
| this.type = type; |
| this.exactReference = exactReference; |
| } |
| |
| /** |
| * Creates an exact type reference using the given type. |
| */ |
| public static TypeReference createExactTrusted(ResolvedJavaType type) { |
| if (type == null) { |
| return null; |
| } |
| return new TypeReference(type, true); |
| } |
| |
| /** |
| * Creates a type reference using the given type without assumptions and without trusting |
| * interface types. |
| */ |
| public static TypeReference createWithoutAssumptions(ResolvedJavaType type) { |
| return create(null, type); |
| } |
| |
| /** |
| * Creates a type reference using the given type without assumptions and trusting interface |
| * types. |
| */ |
| public static TypeReference createTrustedWithoutAssumptions(ResolvedJavaType type) { |
| return createTrusted(null, type); |
| } |
| |
| /** |
| * Creates a type reference using the given type with assumptions and without trusting interface |
| * types. |
| */ |
| public static TypeReference create(Assumptions assumptions, ResolvedJavaType type) { |
| return createTrusted(assumptions, filterInterfaceTypesOut(type)); |
| } |
| |
| /** |
| * Create a type reference using the given type with assumptions and trusting interface types. |
| */ |
| public static TypeReference createTrusted(Assumptions assumptions, ResolvedJavaType type) { |
| if (type == null) { |
| return null; |
| } |
| ResolvedJavaType exactType = type.isLeaf() ? type : null; |
| if (exactType == null) { |
| Assumptions.AssumptionResult<ResolvedJavaType> leafConcreteSubtype = type.findLeafConcreteSubtype(); |
| if (leafConcreteSubtype != null && leafConcreteSubtype.canRecordTo(assumptions)) { |
| leafConcreteSubtype.recordTo(assumptions); |
| exactType = leafConcreteSubtype.getResult(); |
| } |
| } |
| if (exactType == null) { |
| return new TypeReference(type, false); |
| } |
| return new TypeReference(exactType, true); |
| } |
| |
| /** |
| * The type this reference refers to. |
| */ |
| public ResolvedJavaType getType() { |
| return type; |
| } |
| |
| /** |
| * @return {@code true} if this reference is exact and only refers to the given type and |
| * {@code false} if it also refers to its sub types. |
| */ |
| public boolean isExact() { |
| return exactReference; |
| } |
| |
| /** |
| * @return A new reference that is guaranteed to be exact. |
| */ |
| public TypeReference asExactReference() { |
| if (isExact()) { |
| return this; |
| } |
| return new TypeReference(type, true); |
| } |
| |
| private static ResolvedJavaType filterInterfaceTypesOut(ResolvedJavaType type) { |
| if (type != null) { |
| if (type.isArray()) { |
| ResolvedJavaType componentType = filterInterfaceTypesOut(type.getComponentType()); |
| if (componentType != null) { |
| return componentType.getArrayClass(); |
| } |
| // Returns Object[].class |
| return type.getSuperclass().getArrayClass(); |
| } |
| if (type.isInterface()) { |
| return null; |
| } |
| } |
| return type; |
| } |
| |
| @Override |
| public String toString() { |
| return (isExact() ? "#" : "") + type; |
| } |
| } |