| // Copyright 2017 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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 com.google.devtools.build.android.desugar; |
| |
| import static org.objectweb.asm.Opcodes.INVOKESTATIC; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.devtools.build.android.desugar.io.CoreLibraryRewriter; |
| import org.objectweb.asm.ClassVisitor; |
| import org.objectweb.asm.MethodVisitor; |
| import org.objectweb.asm.Opcodes; |
| |
| /** This class rewrites (or removes) some trivial primitive wrapper methods. */ |
| public class PrimitiveWrapperRewriter extends ClassVisitor { |
| |
| /** Classes with no-op {@code hashCode(primitive)} static methods, and their descriptors. */ |
| private static final ImmutableMap<String, String> NOOP_HASHCODE_DESC = |
| ImmutableMap.of( |
| "java/lang/Integer", "(I)I", |
| "java/lang/Short", "(S)I", |
| "java/lang/Byte", "(B)I", |
| "java/lang/Character", "(C)I"); |
| |
| private final CoreLibraryRewriter rewriter; |
| |
| public PrimitiveWrapperRewriter(ClassVisitor cv, CoreLibraryRewriter rewriter) { |
| super(Opcodes.ASM7, cv); |
| this.rewriter = rewriter; |
| } |
| |
| @Override |
| public MethodVisitor visitMethod( |
| int access, String name, String desc, String signature, String[] exceptions) { |
| MethodVisitor visitor = super.cv.visitMethod(access, name, desc, signature, exceptions); |
| return visitor == null ? visitor : new PrimitiveWrapperMethodVisitor(visitor); |
| } |
| |
| private class PrimitiveWrapperMethodVisitor extends MethodVisitor { |
| |
| public PrimitiveWrapperMethodVisitor(MethodVisitor visitor) { |
| super(Opcodes.ASM7, visitor); |
| } |
| |
| @Override |
| public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) { |
| String noopDescriptor = NOOP_HASHCODE_DESC.get(rewriter.unprefix(owner)); |
| if (opcode == INVOKESTATIC |
| && !itf |
| && name.equals("hashCode") |
| && noopDescriptor != null |
| && noopDescriptor.equals(desc)) { |
| return; // skip: use original primitive value as its hash (b/147139686) |
| } |
| super.visitMethodInsn(opcode, owner, name, desc, itf); |
| } |
| } |
| } |