mirror of
https://github.com/wpilibsuite/allwpilib
synced 2026-06-22 01:11:42 +00:00
fbdc810887
* Use explicit this capture required by C++20 * Use C++20 span * Replace wpi::numbers with std::numbers * Fix C++20 clang-tidy warning false positive in fmt * Remove ciso646 include since C++20 removed that header * Fix global-buffer-overflow asan warnings in ntcore tests * Add DIOSetProxy constructor to HAL * Upgrade MSVC compiler to 2022 * Bump native-utils to 2023.2.7 (changes to std=c++20) Co-authored-by: Peter Johnson <johnson.peter@gmail.com>
119 lines
2.1 KiB
C++
119 lines
2.1 KiB
C++
// Copyright (c) FIRST and other WPILib contributors.
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// Open Source Software; you can modify and/or share it under the terms of
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// the WPILib BSD license file in the root directory of this project.
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#include "wpi/leb128.h"
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#include "wpi/SpanExtras.h"
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#include "wpi/raw_istream.h"
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#include "wpi/raw_ostream.h"
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namespace wpi {
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uint64_t SizeUleb128(uint64_t val) {
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size_t count = 0;
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do {
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val >>= 7;
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++count;
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} while (val != 0);
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return count;
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}
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uint64_t WriteUleb128(SmallVectorImpl<char>& dest, uint64_t val) {
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size_t count = 0;
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do {
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uint8_t byte = val & 0x7f;
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val >>= 7;
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if (val != 0) {
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byte |= 0x80; // mark this byte to show that more bytes will follow
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}
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dest.push_back(byte);
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count++;
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} while (val != 0);
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return count;
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}
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void WriteUleb128(raw_ostream& os, uint64_t val) {
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do {
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uint8_t byte = val & 0x7f;
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val >>= 7;
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if (val != 0) {
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byte |= 0x80; // mark this byte to show that more bytes will follow
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}
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os << byte;
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} while (val != 0);
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}
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uint64_t ReadUleb128(const char* addr, uint64_t* ret) {
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uint64_t result = 0;
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int shift = 0;
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size_t count = 0;
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while (1) {
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unsigned char byte = *reinterpret_cast<const unsigned char*>(addr);
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addr++;
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count++;
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result |= (byte & 0x7fULL) << shift;
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shift += 7;
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if (!(byte & 0x80)) {
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break;
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}
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}
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*ret = result;
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return count;
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}
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bool ReadUleb128(raw_istream& is, uint64_t* ret) {
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uint64_t result = 0;
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int shift = 0;
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while (1) {
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unsigned char byte;
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is.read(reinterpret_cast<char*>(&byte), 1);
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if (is.has_error()) {
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return false;
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}
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result |= (byte & 0x7fULL) << shift;
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shift += 7;
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if (!(byte & 0x80)) {
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break;
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}
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}
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*ret = result;
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return true;
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}
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std::optional<uint64_t> Uleb128Reader::ReadOne(std::span<const uint8_t>* in) {
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while (!in->empty()) {
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uint8_t byte = in->front();
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*in = wpi::drop_front(*in);
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m_result |= (byte & 0x7fULL) << m_shift;
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m_shift += 7;
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if (!(byte & 0x80)) {
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uint64_t result = m_result;
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m_result = 0;
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m_shift = 0;
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return result;
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}
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}
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return std::nullopt;
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}
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} // namespace wpi
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