// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include "common/assert.h"
namespace FileSys {
template <typename T>
constexpr int Strlen(const T* str) {
ASSERT(str != nullptr);
int length = 0;
while (*str++) {
++length;
}
return length;
}
template <typename T>
constexpr int Strnlen(const T* str, int count) {
ASSERT(str != nullptr);
ASSERT(count >= 0);
int length = 0;
while (count-- && *str++) {
++length;
}
return length;
}
template <typename T>
constexpr int Strncmp(const T* lhs, const T* rhs, int count) {
ASSERT(lhs != nullptr);
ASSERT(rhs != nullptr);
ASSERT(count >= 0);
if (count == 0) {
return 0;
}
T l, r;
do {
l = *(lhs++);
r = *(rhs++);
} while (l && (l == r) && (--count));
return l - r;
}
template <typename T>
static constexpr int Strlcpy(T* dst, const T* src, int count) {
ASSERT(dst != nullptr);
ASSERT(src != nullptr);
const T* cur = src;
if (count > 0) {
while ((--count) && *cur) {
*(dst++) = *(cur++);
}
*dst = 0;
}
while (*cur) {
cur++;
}
return static_cast<int>(cur - src);
}
enum CharacterEncodingResult {
CharacterEncodingResult_Success = 0,
CharacterEncodingResult_InsufficientLength = 1,
CharacterEncodingResult_InvalidFormat = 2,
};
namespace impl {
class CharacterEncodingHelper {
public:
static constexpr int8_t Utf8NBytesInnerTable[0x100 + 1] = {
-1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 8,
};
static constexpr char GetUtf8NBytes(size_t i) {
return static_cast<char>(Utf8NBytesInnerTable[1 + i]);
}
};
} // namespace impl
constexpr inline CharacterEncodingResult ConvertCharacterUtf8ToUtf32(u32* dst, const char* src) {
// Check pre-conditions
ASSERT(dst != nullptr);
ASSERT(src != nullptr);
// Perform the conversion
const auto* p = src;
switch (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[0]))) {
case 1:
*dst = static_cast<u32>(p[0]);
return CharacterEncodingResult_Success;
case 2:
if ((static_cast<u32>(p[0]) & 0x1E) != 0) {
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) ==
0) {
*dst = (static_cast<u32>(p[0] & 0x1F) << 6) | (static_cast<u32>(p[1] & 0x3F) << 0);
return CharacterEncodingResult_Success;
}
}
break;
case 3:
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[2])) == 0) {
const u32 c = (static_cast<u32>(p[0] & 0xF) << 12) |
(static_cast<u32>(p[1] & 0x3F) << 6) |
(static_cast<u32>(p[2] & 0x3F) << 0);
if ((c & 0xF800) != 0 && (c & 0xF800) != 0xD800) {
*dst = c;
return CharacterEncodingResult_Success;
}
}
return CharacterEncodingResult_InvalidFormat;
case 4:
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[2])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[3])) == 0) {
const u32 c =
(static_cast<u32>(p[0] & 0x7) << 18) | (static_cast<u32>(p[1] & 0x3F) << 12) |
(static_cast<u32>(p[2] & 0x3F) << 6) | (static_cast<u32>(p[3] & 0x3F) << 0);
if (c >= 0x10000 && c < 0x110000) {
*dst = c;
return CharacterEncodingResult_Success;
}
}
return CharacterEncodingResult_InvalidFormat;
default:
break;
}
// We failed to convert
return CharacterEncodingResult_InvalidFormat;
}
constexpr inline CharacterEncodingResult PickOutCharacterFromUtf8String(char* dst,
const char** str) {
// Check pre-conditions
ASSERT(dst != nullptr);
ASSERT(str != nullptr);
ASSERT(*str != nullptr);
// Clear the output
dst[0] = 0;
dst[1] = 0;
dst[2] = 0;
dst[3] = 0;
// Perform the conversion
const auto* p = *str;
u32 c = static_cast<u32>(*p);
switch (impl::CharacterEncodingHelper::GetUtf8NBytes(c)) {
case 1:
dst[0] = (*str)[0];
++(*str);
break;
case 2:
if ((p[0] & 0x1E) != 0) {
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) ==
0) {
c = (static_cast<u32>(p[0] & 0x1F) << 6) | (static_cast<u32>(p[1] & 0x3F) << 0);
dst[0] = (*str)[0];
dst[1] = (*str)[1];
(*str) += 2;
break;
}
}
return CharacterEncodingResult_InvalidFormat;
case 3:
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[2])) == 0) {
c = (static_cast<u32>(p[0] & 0xF) << 12) | (static_cast<u32>(p[1] & 0x3F) << 6) |
(static_cast<u32>(p[2] & 0x3F) << 0);
if ((c & 0xF800) != 0 && (c & 0xF800) != 0xD800) {
dst[0] = (*str)[0];
dst[1] = (*str)[1];
dst[2] = (*str)[2];
(*str) += 3;
break;
}
}
return CharacterEncodingResult_InvalidFormat;
case 4:
if (impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[1])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[2])) == 0 &&
impl::CharacterEncodingHelper::GetUtf8NBytes(static_cast<unsigned char>(p[3])) == 0) {
c = (static_cast<u32>(p[0] & 0x7) << 18) | (static_cast<u32>(p[1] & 0x3F) << 12) |
(static_cast<u32>(p[2] & 0x3F) << 6) | (static_cast<u32>(p[3] & 0x3F) << 0);
if (c >= 0x10000 && c < 0x110000) {
dst[0] = (*str)[0];
dst[1] = (*str)[1];
dst[2] = (*str)[2];
dst[3] = (*str)[3];
(*str) += 4;
break;
}
}
return CharacterEncodingResult_InvalidFormat;
default:
return CharacterEncodingResult_InvalidFormat;
}
return CharacterEncodingResult_Success;
}
} // namespace FileSys
