Use C++20 in RemoteVstPlugin (#7916)

- Build RemoteVstPlugin in C++20 mode
- Avoids using std::wstring due to strange issues with it when built
with wineg++. See https://bugs.winehq.org/show_bug.cgi?id=58465
- Fix some memory leaks + minor cleanup of RemoteVstPlugin code
- Rename `F_OPEN_UTF8` to `fopenUtf8`
- Use C++20 in our `determine_version_from_source` CMake function
- Update ZynAddSubFX submodule

include/IoHelper.h

@@ -22,24 +22,31 @@
  *
  */
 
+// NOTE: The LMMS/zynaddsubfx repo contains a copy of this header.
+//       If you modify this file, consider modifying it there as well.
+
 #ifndef LMMS_IO_HELPER_H
 #define LMMS_IO_HELPER_H
 
-#include "lmmsconfig.h"
-
 #include <cstdio>
+#include <limits>
+#include <memory>
+#include <stdexcept>
+#include <string>
+#include <string_view>
 
 #ifdef _WIN32
-#include <windows.h>
+#	ifndef NOMINMAX
+#		define NOMINMAX
+#	endif
+#	include <windows.h>
 #endif
 
-#ifdef LMMS_BUILD_WIN32
-#include <io.h>
-#else
-#ifdef LMMS_HAVE_UNISTD_H
-#include <unistd.h>
+#if defined(_WIN32) && !defined(__WINE__)
+#	include <io.h>
+#elif __has_include(<unistd.h>)
+#	include <unistd.h>
 #endif
-#endif // LMMS_BUILD_WIN32
 
 namespace lmms
 {
@@ -47,43 +54,67 @@ namespace lmms
 
 #ifdef _WIN32
 
-inline std::wstring toWString(const std::string& s)
+/**
+ * UTF-8 to wide string conversion
+ * NOTE: Avoids using std::wstring because it does not work correctly with wineg++
+ */
+inline std::unique_ptr<wchar_t[]> toWString(std::string_view utf8)
 {
-	std::wstring ret;
-	int len = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, s.data(),
-			s.length(), nullptr, 0);
-	if (len == 0)
+	std::unique_ptr<wchar_t[]> ret;
+	if (utf8.empty())
 	{
+		ret = std::make_unique<wchar_t[]>(1);
 		return ret;
 	}
-	ret.resize(len);
-	MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, s.data(), s.length(), &ret[0], len);
+
+	if (utf8.length() > static_cast<std::size_t>(std::numeric_limits<int>::max()))
+	{
+		throw std::overflow_error{"toWString: input string is too long"};
+	}
+	const auto utf8Len = static_cast<int>(utf8.length());
+
+	int result = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.data(), utf8Len, nullptr, 0);
+	if (result <= 0)
+	{
+		const DWORD error = ::GetLastError();
+		throw std::invalid_argument{"toWString: failed to get size of result string. error code: " + std::to_string(error)};
+	}
+
+	ret = std::make_unique<wchar_t[]>(result + 1); // includes null terminator
+	result = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.data(), utf8Len, ret.get(), result);
+	if (result <= 0)
+	{
+		const DWORD error = ::GetLastError();
+		throw std::invalid_argument{"toWString: failed to convert. error code: " + std::to_string(error)};
+	}
+
 	return ret;
 }
 
-#endif
+#endif // _WIN32
 
-
-inline FILE* F_OPEN_UTF8(std::string const& fname, const char* mode){
-#ifdef LMMS_BUILD_WIN32
-	return _wfopen(toWString(fname).data(), toWString(mode).data());
+//! std::fopen wrapper that expects UTF-8 encoded `filename` and `mode`
+inline std::FILE* fopenUtf8(const std::string& filename, const char* mode)
+{
+#if defined(_WIN32) && !defined(__WINE__)
+	return _wfopen(toWString(filename).get(), toWString(mode).get());
 #else
-	return fopen(fname.data(), mode);
+	return std::fopen(filename.c_str(), mode);
 #endif
 }
 
-
-inline int fileToDescriptor(FILE* f, bool closeFile = true)
+//! Returns the POSIX file descriptor of the given FILE
+inline int fileToDescriptor(std::FILE* file, bool closeFile = true)
 {
-	if (f == nullptr) {return -1;}
+	if (file == nullptr) { return -1; }
 
-#ifdef LMMS_BUILD_WIN32
-	int fh = _dup(_fileno(f));
+#if defined(_WIN32) && !defined(__WINE__)
+	int fh = _dup(_fileno(file));
 #else
-	int fh = dup(fileno(f));
+	int fh = dup(fileno(file));
 #endif
 
-	if (closeFile) {fclose(f);}
+	if (closeFile) { std::fclose(file); }
 	return fh;
 }
 

include/LocaleHelper.h

@@ -25,6 +25,9 @@
  *
  */
 
+// NOTE: The LMMS/zynaddsubfx repo contains a copy of this header.
+//       If you modify this file, consider modifying it there as well.
+
 #ifndef LMMS_LOCALEHELPER_H
 #define LMMS_LOCALEHELPER_H
 
@@ -36,7 +39,7 @@
 namespace lmms::LocaleHelper
 {
 
-inline double toDouble(QString str, bool* ok = nullptr)
+inline double toDouble(const QString& str, bool* ok = nullptr)
 {
 	bool isOkay;
 	QLocale c(QLocale::C);
@@ -48,16 +51,16 @@ inline double toDouble(QString str, bool* ok = nullptr)
 		german.setNumberOptions(QLocale::RejectGroupSeparator);
 		value = german.toDouble(str, &isOkay);
 	}
-	if (ok != nullptr) {*ok = isOkay;}
+	if (ok != nullptr) { *ok = isOkay; }
 	return value;
 }
 
-inline float toFloat(QString str, bool* ok = nullptr)
+inline float toFloat(const QString& str, bool* ok = nullptr)
 {
 	double d = toDouble(str, ok);
 	if (!std::isinf(d) && std::fabs(d) > std::numeric_limits<float>::max())
 	{
-		if (ok != nullptr) {*ok = false;}
+		if (ok != nullptr) { *ok = false; }
 		return 0.0f;
 	}
 	return static_cast<float>(d);

include/RemotePluginClient.h

@@ -259,8 +259,8 @@ bool RemotePluginClient::processMessage( const message & _m )
 				debugMessage(std::string{"Failed to attach sync data: "} + error.what() + '\n');
 				std::exit(EXIT_FAILURE);
 			}
-			m_bufferSize = m_vstSyncData->m_bufferSize;
-			m_sampleRate = m_vstSyncData->m_sampleRate;
+			m_bufferSize = m_vstSyncData->bufferSize;
+			m_sampleRate = m_vstSyncData->sampleRate;
 			reply_message.id = IdHostInfoGotten;
 			reply = true;
 			break;

include/VstSyncData.h

@@ -48,13 +48,13 @@ struct VstSyncData
 	bool isCycle;
 	float cycleStart;
 	float cycleEnd;
-	bool m_playbackJumped;
-	int m_bufferSize;
-	int m_sampleRate;
-	int m_bpm;
+	bool playbackJumped;
+	int bufferSize;
+	int sampleRate;
+	int bpm;
 
 #ifdef VST_SNC_LATENCY
-	float m_latency;
+	float latency;
 #endif
 } ;
 

include/aeffectx.h

@@ -107,6 +107,7 @@ constexpr int effOpen = 0;
 constexpr int effClose = 1; // currently unused
 constexpr int effSetProgram = 2; // currently unused
 constexpr int effGetProgram = 3; // currently unused
+constexpr int effSetProgramName = 4;
 constexpr int effGetProgramName = 5; // currently unused
 constexpr int effGetParamLabel = 6;
 constexpr int effGetParamDisplay = 7;
@@ -119,8 +120,10 @@ constexpr int effEditOpen = 14;
 constexpr int effEditClose = 15;
 constexpr int effEditIdle = 19;
 constexpr int effEditTop = 20;
+constexpr int effGetChunk = 23;
 constexpr int effSetChunk = 24;
 constexpr int effProcessEvents = 25;
+constexpr int effGetProgramNameIndexed = 29;
 constexpr int effGetEffectName = 45;
 constexpr int effGetVendorString = 47;
 constexpr int effGetProductString = 48;