1 /*
2 * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.reflect.code.op;
27
28 import java.lang.reflect.code.*;
29 import java.util.HashMap;
30 import java.util.List;
31 import java.util.Map;
32 import java.util.function.Function;
33
34 /**
35 * An operation that supports externalization of its content and reconstruction
36 * via an instance of {@link ExternalizedOp}.
37 * <p>
38 * The specific content of an externalizable operation can be externalized to a
39 * map of {@link #attributes attributes}, and is reconstructed from the
40 * attributes component of an instance of {@link ExternalizedOp}.
41 * <p>
42 * An externalizable operation could be externalized via serialization to
43 * a textual representation. That textual representation could then be deserialized,
44 * via parsing, into an instance of {@link ExternalizedOp} from which a new
45 * externalizable operation can be reconstructed that is identical to one that
46 * was serialized.
47 */
48 public abstract class ExternalizableOp extends Op {
49
50 /**
51 * An operation's externalized content (a record) that can be utilized to construct an instance
52 * of an {@link ExternalizableOp} associated with the operation's name.
53 *
54 * @param name the operation name
55 * @param operands the list of operands
56 * @param successors the list of successors
57 * @param resultType the operation result type
58 * @param attributes the operation's specific content as an attributes map, modifiable
59 * @param bodyDefinitions the list of body builders for building the operation's bodies
60 * @apiNote Deserializers of operations may utilize this record to construct operations,
61 * thereby separating the specifics of deserializing from construction.
62 */
63 public record ExternalizedOp(String name,
64 List<Value> operands,
65 List<Block.Reference> successors,
66 TypeElement resultType,
67 Map<String, Object> attributes,
68 List<Body.Builder> bodyDefinitions) {
69
70 /**
71 * Removes an attribute value from the attributes map, converts the value by applying it
72 * to mapping function, and returns the result.
73 *
74 * <p>If the attribute is a default attribute then this method first attempts to
75 * remove the attribute whose name is the empty string, otherwise if there is no such
76 * attribute present or the attribute is not a default attribute then this method
77 * attempts to remove the attribute with the given name.
78 *
79 * <p>On successful removal of the attribute its value is converted by applying the value
80 * to the mapping function.
81 *
82 * @param name the attribute name.
83 * @param isDefault true if the attribute is a default attribute
84 * @param <T> the converted attribute value type
85 * @return the converted attribute value
86 * @throws IllegalArgumentException if there is no attribute present
87 */
88 public <T> T extractAttributeValue(String name, boolean isDefault, Function<Object, T> mapper) {
89 Object value = attributes.remove(isDefault ? "" : name);
90 if (value == null) {
91 if (!isDefault) {
92 throw new IllegalArgumentException("Required attribute not present: "
93 + name);
94 }
95
96 value = attributes.remove(name);
97 }
98
99 return mapper.apply(value);
100 }
101
102 /**
103 * Externalizes an operation's content.
104 * <p>
105 * If the operation is an instanceof {@code ExternalizableOp} then the operation's
106 * specific content is externalized to an attribute map, otherwise the attribute map
107 * is empty.
108 *
109 * @param cc the copy context
110 * @param op the operation
111 * @return the operation's content.
112 */
113 public static ExternalizedOp externalizeOp(CopyContext cc, Op op) {
114 return new ExternalizedOp(
115 op.opName(),
116 cc.getValues(op.operands()),
117 op.successors().stream().map(cc::getSuccessorOrCreate).toList(),
118 op.resultType(),
119 op instanceof ExternalizableOp exop ? new HashMap<>(exop.attributes()) : new HashMap<>(),
120 op.bodies().stream().map(b -> b.copy(cc)).toList()
121 );
122 }
123 }
124
125 /**
126 * The attribute name associated with the location attribute.
127 */
128 public static final String ATTRIBUTE_LOCATION = "loc";
129
130 /**
131 * The attribute value that represents the external null value.
132 */
133 public static final Object NULL_ATTRIBUTE_VALUE = new Object();
134
135 /**
136 * Constructs an operation by copying given operation.
137 *
138 * @param that the operation to copy.
139 * @param cc the copy context.
140 * @implSpec The default implementation calls the constructor with the operation's name, result type, and a list
141 * values computed, in order, by mapping the operation's operands using the copy context.
142 */
143 protected ExternalizableOp(Op that, CopyContext cc) {
144 super(that, cc);
145 }
146
147 /**
148 * Constructs an operation with a name, operation result type, and list of operands.
149 *
150 * @param name the operation name.
151 * @param operands the list of operands, a copy of the list is performed if required.
152 */
153 protected ExternalizableOp(String name, List<? extends Value> operands) {
154 super(name, operands);
155 }
156
157 /**
158 * Constructs an operation from its external content.
159 *
160 * @param def the operation's external content.
161 * @implSpec This implementation invokes the {@link Op#Op(String, List) constructor}
162 * accepting the non-optional components of the operation's content, {@code name},
163 * and {@code operands}:
164 * <pre> {@code
165 * this(def.name(), def.operands());
166 * }</pre>
167 */
168 @SuppressWarnings("this-escape")
169 protected ExternalizableOp(ExternalizedOp def) {
170 super(def.name(), def.operands());
171 setLocation(extractLocation(def));
172 }
173
174 static Location extractLocation(ExternalizedOp def) {
175 Object v = def.attributes().get(ATTRIBUTE_LOCATION);
176 return switch (v) {
177 case String s -> Location.fromString(s);
178 case Location loc -> loc;
179 case null -> null;
180 default -> throw new UnsupportedOperationException("Unsupported location value:" + v);
181 };
182 }
183
184 /**
185 * Externalizes the operation's specific content as a map of attributes.
186 *
187 * <p>A null attribute value is represented by the constant
188 * value {@link #NULL_ATTRIBUTE_VALUE}.
189 *
190 * @return the operation's attributes, as an unmodifiable map
191 */
192 public Map<String, Object> attributes() {
193 Location l = location();
194 return l == null ? Map.of() : Map.of(ATTRIBUTE_LOCATION, l);
195 }
196 }