com.google.devtools.build.android.desugar.CoreLibraryInvocationRewriter.java Source code

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Here is the source code for com.google.devtools.build.android.desugar.CoreLibraryInvocationRewriter.java

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// Copyright 2018 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 com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

/**
 * Rewriter of default and static interface methods defined in some core libraries.
 *
 * <p>This is conceptually similar to call site rewriting in {@link InterfaceDesugaring} but here
 * we're doing it for certain bootclasspath methods and in particular for invokeinterface and
 * invokevirtual, which are ignored in regular {@link InterfaceDesugaring}.
 */
public class CoreLibraryInvocationRewriter extends ClassVisitor {

    private final CoreLibrarySupport support;

    public CoreLibraryInvocationRewriter(ClassVisitor cv, CoreLibrarySupport support) {
        super(Opcodes.ASM6, cv);
        this.support = support;
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
        MethodVisitor result = super.visitMethod(access, name, desc, signature, exceptions);
        return result != null ? new CoreLibraryMethodInvocationRewriter(result) : null;
    }

    private class CoreLibraryMethodInvocationRewriter extends MethodVisitor {
        public CoreLibraryMethodInvocationRewriter(MethodVisitor mv) {
            super(Opcodes.ASM6, mv);
        }

        @Override
        public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) {
            Class<?> coreInterface = support.getCoreInterfaceRewritingTarget(opcode, owner, name, desc, itf);

            if (coreInterface != null) {
                String coreInterfaceName = coreInterface.getName().replace('.', '/');
                name = InterfaceDesugaring.normalizeInterfaceMethodName(name, name.startsWith("lambda$"),
                        opcode == Opcodes.INVOKESTATIC);
                if (opcode == Opcodes.INVOKESTATIC) {
                    checkState(owner.equals(coreInterfaceName));
                } else {
                    desc = InterfaceDesugaring.companionDefaultMethodDescriptor(coreInterfaceName, desc);
                }

                if (opcode == Opcodes.INVOKESTATIC || opcode == Opcodes.INVOKESPECIAL) {
                    checkArgument(itf || opcode == Opcodes.INVOKESPECIAL,
                            "Expected interface to rewrite %s.%s : %s", owner, name, desc);
                    owner = coreInterface.isInterface()
                            ? InterfaceDesugaring.getCompanionClassName(coreInterfaceName)
                            : checkNotNull(support.getMoveTarget(coreInterfaceName, name));
                } else {
                    checkState(coreInterface.isInterface());
                    owner = coreInterfaceName + "$$Dispatch";
                }

                opcode = Opcodes.INVOKESTATIC;
                itf = false;
            } else {
                String newOwner = support.getMoveTarget(owner, name);
                if (newOwner != null) {
                    if (opcode != Opcodes.INVOKESTATIC) {
                        // assuming a static method
                        desc = InterfaceDesugaring.companionDefaultMethodDescriptor(owner, desc);
                        opcode = Opcodes.INVOKESTATIC;
                    }
                    owner = newOwner;
                    itf = false; // assuming a class
                }
            }
            super.visitMethodInsn(opcode, owner, name, desc, itf);
        }
    }
}