| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| #ifndef _LINKER_SLEB128_H |
| #define _LINKER_SLEB128_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), end_(buffer+count) { } |
| |
| 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 { |
| if (current_ >= end_) { |
| __libc_fatal("sleb128_decoder ran out of bounds"); |
| } |
| 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_; |
| const uint8_t* const end_; |
| }; |
| |
| #endif // __LINKER_SLEB128_H |