desruisseaux commented on code in PR #1144: URL: https://github.com/apache/maven-compiler-plugin/pull/1144#discussion_r4179320666
########## src/main/java/org/apache/maven/plugin/compiler/incremental/ClassAnalyzer.java: ########## @@ -0,0 +1,250 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.maven.plugin.compiler.incremental; + +import java.io.IOException; +import java.nio.file.Files; +import java.nio.file.Path; +import java.util.Collections; +import java.util.List; +import java.util.Set; + +/** + * Abstract base for analyzing compiled {@code .class} files. + * + * <p>The single built-in implementation is: + * <ul> + * <li>{@code ClassfileClassAnalyzer} — uses the standard + * {@code java.lang.classfile} API introduced in JDK 24; loaded + * reflectively at runtime. Requires JDK 24 or later.</li> + * </ul> + * + * <p>Use {@link BytecodeAnalyzer#analyze(byte[])} which selects the best + * available implementation automatically. + * + * @see BytecodeAnalyzer + */ +public abstract class ClassAnalyzer { + + // JVM spec access flag constants — shared by both implementations + protected static final int ACC_PUBLIC = 0x0001; + protected static final int ACC_PRIVATE = 0x0002; + protected static final int ACC_PROTECTED = 0x0004; + protected static final int ACC_STATIC = 0x0008; + protected static final int ACC_FINAL = 0x0010; + protected static final int ACC_INTERFACE = 0x0200; + protected static final int ACC_ABSTRACT = 0x0400; + protected static final int ACC_SYNTHETIC = 0x1000; + protected static final int ACC_ENUM = 0x4000; + + protected static final Set<String> EXCLUDED_SUPERTYPES = + Set.of("java.lang.Object", "java.lang.Enum", "java.lang.Record"); + + /** + * A non-private, non-synthetic field extracted from a class file. + * + * @param access JVM access flags bitmask + * @param name field name + * @param descriptor JVM type descriptor + * @param constantValue compile-time constant value, or {@code null} + * @param signature generic signature from the Signature attribute, or {@code null} + */ + protected record FieldInfo(int access, String name, String descriptor, Object constantValue, String signature) + implements Comparable<FieldInfo> { + @Override + public int compareTo(FieldInfo o) { + return name.compareTo(o.name); + } + } + + /** + * A non-private, non-synthetic method extracted from a class file. + * + * @param access JVM access flags bitmask + * @param name method name + * @param descriptor JVM method descriptor + * @param signature generic signature from the Signature attribute, or {@code null} + */ + protected record MethodInfo(int access, String name, String descriptor, String signature) + implements Comparable<MethodInfo> { + @Override + public int compareTo(MethodInfo o) { + int c = name.compareTo(o.name); + return c != 0 ? c : descriptor.compareTo(o.descriptor); + } + } + + /** + * Analyzes the given class file bytes. + * + * @param classBytes raw {@code .class} file content + * @return analysis result containing class name, ABI fingerprint, canonical + * form, and referenced type names + */ + public abstract BytecodeAnalyzer.ClassAnalysis analyze(byte[] classBytes); + + /** + * Analyzes the class file at the given path. + * + * @param classFile path to the {@code .class} file + * @return analysis result + * @throws IOException if reading the file fails + */ + public BytecodeAnalyzer.ClassAnalysis analyze(Path classFile) throws IOException { + return analyze(Files.readAllBytes(classFile)); + } + + /** + * Builds the ABI canonical form from extracted class metadata. + * The format is deterministic and identical across both analyzer + * implementations, ensuring consistent fingerprints. + * + * @param classAccess JVM access flags for the class + * @param className fully-qualified class name (dot-separated) + * @param classSignature generic signature of the class, or {@code null} + * @param superName fully-qualified superclass name, or {@code null} + * @param interfaces fully-qualified interface names (dot-separated) + * @param fields non-private, non-synthetic fields (will be sorted) + * @param methods non-private, non-synthetic methods (will be sorted) + * @return the canonical ABI string + */ + protected static String buildCanonicalForm( + int classAccess, + String className, + String classSignature, + String superName, + List<String> interfaces, + List<FieldInfo> fields, + List<MethodInfo> methods) { + + Collections.sort(fields); + Collections.sort(methods); + + var sb = new StringBuilder(); + + appendAccessFlags(sb, classAccess); + if ((classAccess & ACC_INTERFACE) != 0) { + sb.append("interface "); + } else if ((classAccess & ACC_ENUM) != 0) { + sb.append("enum "); + } else { + sb.append("class "); + } + sb.append(className); + if (classSignature != null) { + sb.append(" <sig: ").append(classSignature).append('>'); + } + sb.append('\n'); + + if (superName != null && !EXCLUDED_SUPERTYPES.contains(superName)) { + sb.append(" extends ").append(superName).append('\n'); + } + + for (String iface : interfaces) { + sb.append(" implements ").append(iface).append('\n'); + } + + for (var f : fields) { + sb.append(" "); + appendAccessFlags(sb, f.access); + sb.append(BytecodeAnalyzer.descriptorToReadable(f.descriptor)).append(' '); + sb.append(f.name); + if (f.constantValue != null) { + sb.append(" = ").append(f.constantValue); + } + if (f.signature != null) { + sb.append(" <sig: ").append(f.signature).append('>'); + } + sb.append('\n'); + } + + for (var m : methods) { + sb.append(" "); + appendAccessFlags(sb, m.access); + sb.append(m.name); + sb.append('(').append(BytecodeAnalyzer.parseParams(m.descriptor)).append(')'); + String ret = BytecodeAnalyzer.parseReturn(m.descriptor); + if (!"void".equals(ret)) { + sb.append(" -> ").append(ret); + } + if (m.signature != null) { + sb.append(" <sig: ").append(m.signature).append('>'); + } + sb.append('\n'); + } + + return sb.toString(); + } + + /** + * Appends the human-readable access flag names (public, protected, abstract, + * static, final) to the builder, in the canonical order. + */ + protected static void appendAccessFlags(StringBuilder sb, int access) { Review Comment: Just store the `int` flag in binary, no need to make it human-readable. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
