Common: Rename UTF16ToUTF8

This function does *not* always convert from UTF-16. It converts
from UTF-16 on Windows and UTF-32 on other operating systems.

Also renaming UTF8ToUTF16 for consistency, even though it
technically doesn't have the same problem since it only was
implemented on Windows.

Source/Core/Common/FileUtil.cpp

@@ -114,7 +114,7 @@ bool Exists(const std::string& path)
 bool IsDirectory(const std::string& path)
 {
 #ifdef _WIN32
-  return PathIsDirectory(UTF8ToUTF16(path).c_str());
+  return PathIsDirectory(UTF8ToWString(path).c_str());
 #else
   return FileInfo(path).IsDirectory();
 #endif

Source/Core/Common/Logging/ConsoleListenerWin.cpp

@@ -17,5 +17,5 @@ ConsoleListener::~ConsoleListener()
 
 void ConsoleListener::Log([[maybe_unused]] Common::Log::LOG_LEVELS level, const char* text)
 {
-  ::OutputDebugStringW(UTF8ToUTF16(text).c_str());
+  ::OutputDebugStringW(UTF8ToWString(text).c_str());
 }

Source/Core/Common/StringUtil.cpp

@@ -457,29 +457,29 @@ std::string UTF16ToCP(u32 code_page, std::wstring_view input)
   return output;
 }
 
-std::wstring UTF8ToUTF16(std::string_view input)
+std::wstring UTF8ToWString(std::string_view input)
 {
   return CPToUTF16(CP_UTF8, input);
 }
 
-std::string UTF16ToUTF8(std::wstring_view input)
+std::string WStringToUTF8(std::wstring_view input)
 {
   return UTF16ToCP(CP_UTF8, input);
 }
 
 std::string SHIFTJISToUTF8(std::string_view input)
 {
-  return UTF16ToUTF8(CPToUTF16(CODEPAGE_SHIFT_JIS, input));
+  return WStringToUTF8(CPToUTF16(CODEPAGE_SHIFT_JIS, input));
 }
 
 std::string UTF8ToSHIFTJIS(std::string_view input)
 {
-  return UTF16ToCP(CODEPAGE_SHIFT_JIS, UTF8ToUTF16(input));
+  return UTF16ToCP(CODEPAGE_SHIFT_JIS, UTF8ToWString(input));
 }
 
 std::string CP1252ToUTF8(std::string_view input)
 {
-  return UTF16ToUTF8(CPToUTF16(CODEPAGE_WINDOWS_1252, input));
+  return WStringToUTF8(CPToUTF16(CODEPAGE_WINDOWS_1252, input));
 }
 
 std::string UTF16BEToUTF8(const char16_t* str, size_t max_size)
@@ -487,7 +487,7 @@ std::string UTF16BEToUTF8(const char16_t* str, size_t max_size)
   const char16_t* str_end = std::find(str, str + max_size, '\0');
   std::wstring result(static_cast<size_t>(str_end - str), '\0');
   std::transform(str, str_end, result.begin(), static_cast<u16 (&)(u16)>(Common::swap16));
-  return UTF16ToUTF8(result);
+  return WStringToUTF8(result);
 }
 
 #else
@@ -572,7 +572,7 @@ std::string UTF8ToSHIFTJIS(std::string_view input)
   return CodeTo("SJIS", "UTF-8", input);
 }
 
-std::string UTF16ToUTF8(std::wstring_view input)
+std::string WStringToUTF8(std::wstring_view input)
 {
   std::wstring_convert<std::codecvt_utf8<wchar_t>, wchar_t> converter;
   return converter.to_bytes(input.data(), input.data() + input.size());
@@ -591,7 +591,7 @@ std::string UTF16BEToUTF8(const char16_t* str, size_t max_size)
 std::filesystem::path StringToPath(std::string_view path)
 {
 #ifdef _MSC_VER
-  return std::filesystem::path(UTF8ToUTF16(path));
+  return std::filesystem::path(UTF8ToWString(path));
 #else
   return std::filesystem::path(path);
 #endif
@@ -602,7 +602,7 @@ std::filesystem::path StringToPath(std::string_view path)
 std::string PathToString(const std::filesystem::path& path)
 {
 #ifdef _MSC_VER
-  return UTF16ToUTF8(path.native());
+  return WStringToUTF8(path.native());
 #else
   return path.native();
 #endif

Source/Core/Common/StringUtil.h

@@ -171,22 +171,22 @@ void StringPopBackIf(std::string* s, char c);
 std::string CP1252ToUTF8(std::string_view str);
 std::string SHIFTJISToUTF8(std::string_view str);
 std::string UTF8ToSHIFTJIS(std::string_view str);
-std::string UTF16ToUTF8(std::wstring_view str);
+std::string WStringToUTF8(std::wstring_view str);
 std::string UTF16BEToUTF8(const char16_t* str, size_t max_size);  // Stops at \0
 
 #ifdef _WIN32
 
-std::wstring UTF8ToUTF16(std::string_view str);
+std::wstring UTF8ToWString(std::string_view str);
 
 #ifdef _UNICODE
 inline std::string TStrToUTF8(std::wstring_view str)
 {
-  return UTF16ToUTF8(str);
+  return WStringToUTF8(str);
 }
 
 inline std::wstring UTF8ToTStr(std::string_view str)
 {
-  return UTF8ToUTF16(str);
+  return UTF8ToWString(str);
 }
 #else
 inline std::string TStrToUTF8(std::string_view str)
@@ -220,7 +220,7 @@ std::string ThousandSeparate(I value, int spaces = 0)
   stream << std::setw(spaces) << value;
 
 #ifdef _WIN32
-  return UTF16ToUTF8(stream.str());
+  return WStringToUTF8(stream.str());
 #else
   return stream.str();
 #endif

Source/Core/Common/Timer.cpp

@@ -218,7 +218,7 @@ std::string Timer::GetTimeFormatted()
 #ifdef _WIN32
   struct timeb tp;
   (void)::ftime(&tp);
-  return UTF16ToUTF8(tmp) + fmt::format(":{:03}", tp.millitm);
+  return WStringToUTF8(tmp) + fmt::format(":{:03}", tp.millitm);
 #elif defined __APPLE__
   struct timeval t;
   (void)gettimeofday(&t, nullptr);
@@ -276,7 +276,7 @@ std::string Timer::GetDateTimeFormatted(double time)
 #ifdef _WIN32
   wchar_t tmp[32] = {};
   wcsftime(tmp, sizeof(tmp), L"%x %X", localTime);
-  return UTF16ToUTF8(tmp);
+  return WStringToUTF8(tmp);
 #else
   char tmp[32] = {};
   strftime(tmp, sizeof(tmp), "%x %X", localTime);