| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #ifndef _LINKER_SLEB128_H |
| #define _LINKER_SLEB128_H |
| |
| #include <assert.h> |
| #include <stdint.h> |
| |
| // Helper classes for decoding LEB128, used in packed relocation data. |
| // http://en.wikipedia.org/wiki/LEB128 |
| |
| class sleb128_decoder { |
| public: |
| sleb128_decoder(const uint8_t* buffer, size_t count) |
| : current_(buffer) |
| #ifndef NDEBUG |
| , |
| end_(buffer + count) |
| #endif |
| { |
| } |
| size_t pop_front() { |
| size_t value = 0; |
| static const size_t size = CHAR_BIT * sizeof(value); |
| |
| size_t shift = 0; |
| uint8_t byte; |
| |
| do { |
| assert(current_ < end_); |
| byte = *current_++; |
| value |= (static_cast<size_t>(byte & 127) << shift); |
| shift += 7; |
| } while (byte & 128); |
| |
| if (shift < size && (byte & 64)) { |
| value |= -(static_cast<size_t>(1) << shift); |
| } |
| |
| return value; |
| } |
| |
| private: |
| const uint8_t* current_; |
| #ifndef NDEBUG |
| const uint8_t* const end_; |
| #endif |
| }; |
| |
| #endif // __LINKER_SLEB128_H |