/*
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* Copyright (C) 2015 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#pragma once
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#include <stdint.h>
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#include <async_safe/log.h>
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#include "linker_debug.h"
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// Helper classes for decoding LEB128, used in packed relocation data.
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// http://en.wikipedia.org/wiki/LEB128
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class sleb128_decoder {
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public:
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sleb128_decoder(const uint8_t* buffer, size_t count)
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: current_(buffer), end_(buffer+count) { }
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size_t pop_front() {
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size_t value = 0;
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static const size_t size = CHAR_BIT * sizeof(value);
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size_t shift = 0;
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uint8_t byte;
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do {
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if (current_ >= end_) {
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async_safe_fatal("sleb128_decoder ran out of bounds");
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}
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byte = *current_++;
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value |= (static_cast<size_t>(byte & 127) << shift);
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shift += 7;
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} while (byte & 128);
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if (shift < size && (byte & 64)) {
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value |= -(static_cast<size_t>(1) << shift);
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}
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return value;
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}
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private:
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const uint8_t* current_;
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const uint8_t* const end_;
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};
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