1 /*
 2  * Copyright (c) 2026, 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 package jdk.incubator.code.dialect.java;
26 
27 import jdk.incubator.code.Block;
28 import jdk.incubator.code.CodeContext;
29 import jdk.incubator.code.CodeTransformer;
30 import jdk.incubator.code.Op;
31 
32 import java.lang.invoke.MethodHandles;
33 import java.util.Optional;
34 
35 import static jdk.incubator.code.dialect.core.CoreOp.constant;
36 import static jdk.incubator.code.dialect.java.JavaOp.ConstantExpressionEvaluator;
37 
38 /**
39  * A transformer that replaces every operation that models a constant expression with a constant operation
40  * whose value is the result of evaluating that constant expression.
41  */
42 public class ConstantExpressionTransformer implements CodeTransformer {
43     private final ConstantExpressionEvaluator constantExpressionEvaluator;
44 
45     private ConstantExpressionTransformer(ConstantExpressionEvaluator constantExpressionEvaluator) {
46         this.constantExpressionEvaluator = constantExpressionEvaluator;
47     }
48 
49     @Override
50     public Block.Builder acceptOp(Block.Builder b, Op op) {
51         Optional<Object> v = constantExpressionEvaluator.evaluate(op.result());
52         if (v.isPresent()) {
53             Op.Result c = b.add(constant(op.resultType(), v.get()));
54             b.context().mapValue(op.result(), c);
55         } else {
56             b.add(op);
57         }
58         return b;
59     }
60 
61     /**
62      * Transforms an operation, replacing an operation that models a constant expression with a constant operation
63      * whose value is the result of evaluating that constant expression.
64      *
65      * @param l  the lookup to use for reflective access
66      * @param op the operation to transform
67      * @return the transformed operation
68      */
69     public static Op transform(MethodHandles.Lookup l, Op op) {
70         return op.transform(CodeContext.create(), new ConstantExpressionTransformer(new ConstantExpressionEvaluator(l)));
71     }
72 }