com.facebook.buck.macho.LinkEditDataCommandUtils.java Source code

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Here is the source code for com.facebook.buck.macho.LinkEditDataCommandUtils.java

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/*
 * Copyright 2016-present Facebook, Inc.
 *
 * 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.facebook.buck.macho;

import com.google.common.base.Preconditions;
import com.google.common.primitives.UnsignedInteger;

import java.nio.ByteBuffer;

public class LinkEditDataCommandUtils {
    private LinkEditDataCommandUtils() {
    }

    public static LinkEditDataCommand createFromBuffer(ByteBuffer buffer) {
        return LinkEditDataCommand.of(LoadCommandCommonFieldsUtils.createFromBuffer(buffer),
                UnsignedInteger.fromIntBits(buffer.getInt()), UnsignedInteger.fromIntBits(buffer.getInt()));
    }

    public static void writeCommandToBuffer(LinkEditDataCommand command, ByteBuffer buffer) {
        LoadCommandCommonFieldsUtils.writeCommandToBuffer(command.getLoadCommandCommonFields(), buffer);
        buffer.putInt(command.getDataoff().intValue()).putInt(command.getDatasize().intValue());
    }

    public static void updateLinkEditDataCommand(ByteBuffer buffer, LinkEditDataCommand old,
            LinkEditDataCommand updated) {
        Preconditions.checkArgument(old.getLoadCommandCommonFields().getOffsetInBinary() == updated
                .getLoadCommandCommonFields().getOffsetInBinary());
        buffer.position(updated.getLoadCommandCommonFields().getOffsetInBinary());
        writeCommandToBuffer(updated, buffer);
    }

    public static int alignCodeSignatureOffsetValue(int value) {
        /**
         * Code signature offset is expected to be aligned by 16 bytes:
         * https://opensource.apple.com/source/cctools/cctools-782/libstuff/checkout.c
         * (look for "code signature data out of place" error)
         */
        int alignment = 15;
        value += alignment;
        value &= ~alignment;
        return value;
    }
}