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-rw-r--r--src/core/file_sys/fs_string_util.h241
1 files changed, 241 insertions, 0 deletions
diff --git a/src/core/file_sys/fs_string_util.h b/src/core/file_sys/fs_string_util.h
new file mode 100644
index 000000000..68114e72c
--- /dev/null
+++ b/src/core/file_sys/fs_string_util.h
@@ -0,0 +1,241 @@
+// SPDX-FileCopyrightText: Copyright 2023 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);
+}
+
+/* std::size() does not support zero-size C arrays. We're fixing that. */
+template <class C>
+constexpr auto size(const C& c) -> decltype(c.size()) {
+ return std::size(c);
+}
+
+template <class C>
+constexpr std::size_t size(const C& c) {
+ if constexpr (sizeof(C) == 0) {
+ return 0;
+ } else {
+ return std::size(c);
+ }
+}
+
+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
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