Merge remote-tracking branch 'origin/5.12' into dev

Change-Id: I33e0abc771a2a772d3334172d50e7b0efe896590

40 files changed, 606 insertions, 251 deletions

diff --git a/src/corelib/codecs/qtextcodec_p.h b/src/corelib/codecs/qtextcodec_p.h
index f3c2d090c9..be0cab93e6 100644
--- a/src/corelib/codecs/qtextcodec_p.h
+++ b/src/corelib/codecs/qtextcodec_p.h
@@ -59,7 +59,7 @@ QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_TEXTCODEC
 
-#if defined(Q_OS_MAC) || defined(Q_OS_ANDROID) || defined(Q_OS_QNX)
+#if defined(Q_OS_MAC) || defined(Q_OS_ANDROID) || defined(Q_OS_QNX) || defined(Q_OS_WASM)
 #define QT_LOCALE_IS_UTF8
 #endif
 
diff --git a/src/corelib/configure.json b/src/corelib/configure.json
index 18fc22f18f..183eb3a13e 100644
--- a/src/corelib/configure.json
+++ b/src/corelib/configure.json
@@ -481,7 +481,7 @@
         },
         "eventfd": {
             "label": "eventfd",
-            "condition": "tests.eventfd",
+            "condition": "!config.wasm && tests.eventfd",
             "output": [ "feature" ]
         },
         "futimens": {
@@ -592,7 +592,7 @@
         "poll_ppoll": {
             "label": "Native ppoll()",
             "emitIf": "!config.win32",
-            "condition": "tests.ppoll",
+            "condition": "!config.wasm && tests.ppoll",
             "output": [ "privateFeature" ]
         },
         "poll_pollts": {
diff --git a/src/corelib/global/archdetect.cpp b/src/corelib/global/archdetect.cpp
index 6c1a026fa8..422df3ff90 100644
--- a/src/corelib/global/archdetect.cpp
+++ b/src/corelib/global/archdetect.cpp
@@ -51,6 +51,8 @@
 #  define ARCH_PROCESSOR "avr32"
 #elif defined(Q_PROCESSOR_BLACKFIN)
 #  define ARCH_PROCESSOR "bfin"
+#elif defined(Q_PROCESSOR_WASM)
+#  define ARCH_PROCESSOR "wasm"
 #elif defined(Q_PROCESSOR_X86_32)
 #  define ARCH_PROCESSOR "i386"
 #elif defined(Q_PROCESSOR_X86_64)
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index 2b85ea0815..345ab9e8ad 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -206,6 +206,9 @@
 #        define Q_DECL_NS_RETURNS_AUTORELEASED __attribute__((ns_returns_autoreleased))
 #      endif
 #    endif
+#    ifdef __EMSCRIPTEN__
+#      define Q_CC_EMSCRIPTEN
+#    endif
 #  else
 /* Plain GCC */
 #    if Q_CC_GNU >= 405
diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index a931b43220..9f47b8eb98 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -94,6 +94,10 @@
 # include "private/qcore_unix_p.h"
 #endif
 
+#ifdef Q_OS_WASM
+#include <emscripten/emscripten.h>
+#endif
+
 #if QT_CONFIG(regularexpression)
 #  ifdef __UCLIBC__
 #    if __UCLIBC_HAS_BACKTRACE__
@@ -1690,6 +1694,37 @@ static bool win_message_handler(QtMsgType type, const QMessageLogContext &contex
 }
 #endif
 
+#ifdef Q_OS_WASM
+static bool wasm_default_message_handler(QtMsgType type,
+                                  const QMessageLogContext &context,
+                                  const QString &message)
+{
+    if (shouldLogToStderr())
+        return false; // Leave logging up to stderr handler
+
+    QString formattedMessage = qFormatLogMessage(type, context, message);
+    int emOutputFlags = (EM_LOG_CONSOLE | EM_LOG_DEMANGLE);
+    QByteArray localMsg = message.toLocal8Bit();
+    switch (type) {
+    case QtDebugMsg:
+        break;
+    case QtInfoMsg:
+        break;
+    case QtWarningMsg:
+        emOutputFlags |= EM_LOG_WARN;
+        break;
+    case QtCriticalMsg:
+        emOutputFlags |= EM_LOG_ERROR;
+        break;
+    case QtFatalMsg:
+        emOutputFlags |= EM_LOG_ERROR;
+    }
+    emscripten_log(emOutputFlags, "%s\n", qPrintable(formattedMessage));
+
+    return true; // Prevent further output to stderr
+}
+#endif
+
 #endif // Bootstrap check
 
 // --------------------------------------------------------------------------
@@ -1733,8 +1768,9 @@ static void qDefaultMessageHandler(QtMsgType type, const QMessageLogContext &con
 # elif defined(Q_OS_ANDROID) && !defined(Q_OS_ANDROID_EMBEDDED)
     handledStderr |= android_default_message_handler(type, context, message);
 # elif defined(QT_USE_APPLE_UNIFIED_LOGGING)
-    if (__builtin_available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *))
-        handledStderr |= AppleUnifiedLogger::messageHandler(type, context, message);
+    handledStderr |= AppleUnifiedLogger::messageHandler(type, context, message);
+# elif defined Q_OS_WASM
+    handledStderr |= wasm_default_message_handler(type, context, message);
 # endif
 #endif
 
diff --git a/src/corelib/global/qoperatingsystemversion_win.cpp b/src/corelib/global/qoperatingsystemversion_win.cpp
index 7659fb2550..2da190da48 100644
--- a/src/corelib/global/qoperatingsystemversion_win.cpp
+++ b/src/corelib/global/qoperatingsystemversion_win.cpp
@@ -103,7 +103,7 @@ static inline OSVERSIONINFOEX determineWinOsVersion()
 
     // GetVersionEx() has been deprecated in Windows 8.1 and will return
     // only Windows 8 from that version on, so use the kernel API function.
-    pRtlGetVersion((LPOSVERSIONINFO) &result); // always returns STATUS_SUCCESS
+    pRtlGetVersion(reinterpret_cast<LPOSVERSIONINFO>(&result)); // always returns STATUS_SUCCESS
 #else // !Q_OS_WINCE
     GetVersionEx(&result);
 #endif
diff --git a/src/corelib/global/qprocessordetection.h b/src/corelib/global/qprocessordetection.h
index 9a3dfd776d..aaa27dff4a 100644
--- a/src/corelib/global/qprocessordetection.h
+++ b/src/corelib/global/qprocessordetection.h
@@ -320,6 +320,12 @@
 #  endif
 #  define Q_BYTE_ORDER Q_BIG_ENDIAN
 
+// -- Web Assembly --
+#elif defined(__EMSCRIPTEN__)
+#  define Q_PROCESSOR_WASM
+#  define Q_PROCESSOR_X86 6   // enables SIMD support
+#  define Q_BYTE_ORDER Q_LITTLE_ENDIAN
+#  define Q_PROCESSOR_WORDSIZE 8
 #endif
 
 /*
diff --git a/src/corelib/global/qsystemdetection.h b/src/corelib/global/qsystemdetection.h
index cacb95b674..aabe46f3c2 100644
--- a/src/corelib/global/qsystemdetection.h
+++ b/src/corelib/global/qsystemdetection.h
@@ -137,6 +137,8 @@
 #  define Q_OS_HPUX
 #elif defined(__native_client__)
 #  define Q_OS_NACL
+#elif defined(__EMSCRIPTEN__)
+#  define Q_OS_WASM
 #elif defined(__linux__) || defined(__linux)
 #  define Q_OS_LINUX
 #elif defined(__FreeBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
diff --git a/src/corelib/io/qfilesystemengine_unix.cpp b/src/corelib/io/qfilesystemengine_unix.cpp
index 835e6a6a44..0159bc4128 100644
--- a/src/corelib/io/qfilesystemengine_unix.cpp
+++ b/src/corelib/io/qfilesystemengine_unix.cpp
@@ -76,9 +76,7 @@
 #endif
 
 #if defined(Q_OS_DARWIN)
-# if QT_DARWIN_PLATFORM_SDK_EQUAL_OR_ABOVE(101200, 100000, 100000, 30000)
-#  include <sys/clonefile.h>
-# endif
+# include <sys/clonefile.h>
 # include <copyfile.h>
 // We cannot include <Foundation/Foundation.h> (it's an Objective-C header), but
 // we need these declarations:
@@ -860,7 +858,7 @@ QString QFileSystemEngine::resolveUserName(uint userId)
     QVarLengthArray<char, 1024> buf(size_max);
 #endif
 
-#if !defined(Q_OS_INTEGRITY)
+#if !defined(Q_OS_INTEGRITY) && !defined(Q_OS_WASM)
     struct passwd *pw = 0;
 #if QT_CONFIG(thread) && defined(_POSIX_THREAD_SAFE_FUNCTIONS) && !defined(Q_OS_OPENBSD) && !defined(Q_OS_VXWORKS)
     struct passwd entry;
@@ -884,7 +882,7 @@ QString QFileSystemEngine::resolveGroupName(uint groupId)
     QVarLengthArray<char, 1024> buf(size_max);
 #endif
 
-#if !defined(Q_OS_INTEGRITY)
+#if !defined(Q_OS_INTEGRITY) && !defined(Q_OS_WASM)
     struct group *gr = 0;
 #if QT_CONFIG(thread) && defined(_POSIX_THREAD_SAFE_FUNCTIONS) && !defined(Q_OS_OPENBSD) && !defined(Q_OS_VXWORKS) && (!defined(Q_OS_ANDROID) || defined(Q_OS_ANDROID) && (__ANDROID_API__ >= 24))
     size_max = sysconf(_SC_GETGR_R_SIZE_MAX);
@@ -1258,20 +1256,18 @@ bool QFileSystemEngine::createLink(const QFileSystemEntry &source, const QFileSy
 //static
 bool QFileSystemEngine::copyFile(const QFileSystemEntry &source, const QFileSystemEntry &target, QSystemError &error)
 {
-#if QT_DARWIN_PLATFORM_SDK_EQUAL_OR_ABOVE(101200, 100000, 100000, 30000)
-    if (__builtin_available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *)) {
-        if (::clonefile(source.nativeFilePath().constData(),
-                        target.nativeFilePath().constData(), 0) == 0)
-            return true;
-        error = QSystemError(errno, QSystemError::StandardLibraryError);
-        return false;
-    }
+#if defined(Q_OS_DARWIN)
+    if (::clonefile(source.nativeFilePath().constData(),
+                    target.nativeFilePath().constData(), 0) == 0)
+        return true;
+    error = QSystemError(errno, QSystemError::StandardLibraryError);
+    return false;
 #else
     Q_UNUSED(source);
     Q_UNUSED(target);
-#endif
     error = QSystemError(ENOSYS, QSystemError::StandardLibraryError); //Function not implemented
     return false;
+#endif
 }
 
 //static
@@ -1295,13 +1291,11 @@ bool QFileSystemEngine::renameFile(const QFileSystemEntry &source, const QFileSy
     }
 #endif
 #if defined(Q_OS_DARWIN) && defined(RENAME_EXCL)
-    if (__builtin_available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *)) {
-        if (renameatx_np(AT_FDCWD, srcPath, AT_FDCWD, tgtPath, RENAME_EXCL) == 0)
-            return true;
-        if (errno != ENOTSUP) {
-            error = QSystemError(errno, QSystemError::StandardLibraryError);
-            return false;
-        }
+    if (renameatx_np(AT_FDCWD, srcPath, AT_FDCWD, tgtPath, RENAME_EXCL) == 0)
+        return true;
+    if (errno != ENOTSUP) {
+        error = QSystemError(errno, QSystemError::StandardLibraryError);
+        return false;
     }
 #endif
 
diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index fadc058110..74081b4ffa 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -935,7 +935,7 @@ static bool tryFindFallback(const QFileSystemEntry &fname, QFileSystemMetaData &
 bool QFileSystemEngine::fillMetaData(int fd, QFileSystemMetaData &data,
                                      QFileSystemMetaData::MetaDataFlags what)
 {
-    HANDLE fHandle = (HANDLE)_get_osfhandle(fd);
+    auto fHandle = reinterpret_cast<HANDLE>(_get_osfhandle(fd));
     if (fHandle  != INVALID_HANDLE_VALUE) {
         return fillMetaData(fHandle, data, what);
     }
@@ -1014,7 +1014,8 @@ bool QFileSystemEngine::fillMetaData(const QFileSystemEntry &entry, QFileSystemM
         WIN32_FIND_DATA findData;
         // The memory structure for WIN32_FIND_DATA is same as WIN32_FILE_ATTRIBUTE_DATA
         // for all members used by fillFindData().
-        bool ok = ::GetFileAttributesEx((wchar_t*)fname.nativeFilePath().utf16(), GetFileExInfoStandard,
+        bool ok = ::GetFileAttributesEx(reinterpret_cast<const wchar_t*>(fname.nativeFilePath().utf16()),
+                                        GetFileExInfoStandard,
                                         reinterpret_cast<WIN32_FILE_ATTRIBUTE_DATA *>(&findData));
         if (ok) {
             data.fillFromFindData(findData, false, fname.isDriveRoot());
@@ -1069,19 +1070,22 @@ static bool isDirPath(const QString &dirPath, bool *existed)
     if (path.length() == 2 && path.at(1) == QLatin1Char(':'))
         path += QLatin1Char('\\');
 
+    const QString longPath = QFSFileEnginePrivate::longFileName(path);
 #ifndef Q_OS_WINRT
-    DWORD fileAttrib = ::GetFileAttributes((wchar_t*)QFSFileEnginePrivate::longFileName(path).utf16());
+    DWORD fileAttrib = ::GetFileAttributes(reinterpret_cast<const wchar_t*>(longPath.utf16()));
 #else // Q_OS_WINRT
     DWORD fileAttrib = INVALID_FILE_ATTRIBUTES;
     WIN32_FILE_ATTRIBUTE_DATA data;
-    if (::GetFileAttributesEx((const wchar_t*)QFSFileEnginePrivate::longFileName(path).utf16(), GetFileExInfoStandard, &data))
+    if (::GetFileAttributesEx(reinterpret_cast<const wchar_t*>(longPath.utf16()),
+                              GetFileExInfoStandard, &data)) {
         fileAttrib = data.dwFileAttributes;
+    }
 #endif // Q_OS_WINRT
     if (fileAttrib == INVALID_FILE_ATTRIBUTES) {
         int errorCode = GetLastError();
         if (errorCode == ERROR_ACCESS_DENIED || errorCode == ERROR_SHARING_VIOLATION) {
             WIN32_FIND_DATA findData;
-            if (getFindData(QFSFileEnginePrivate::longFileName(path), findData))
+            if (getFindData(longPath, findData))
                 fileAttrib = findData.dwFileAttributes;
         }
     }
@@ -1411,7 +1415,7 @@ bool QFileSystemEngine::setPermissions(const QFileSystemEntry &entry, QFile::Per
     if (mode == 0) // not supported
         return false;
 
-    bool ret = (::_wchmod((wchar_t*)entry.nativeFilePath().utf16(), mode) == 0);
+    bool ret = ::_wchmod(reinterpret_cast<const wchar_t*>(entry.nativeFilePath().utf16()), mode) == 0;
     if(!ret)
         error = QSystemError(errno, QSystemError::StandardLibraryError);
     return ret;
diff --git a/src/corelib/io/qsettings.cpp b/src/corelib/io/qsettings.cpp
index 1134c6bb85..391d2a49af 100644
--- a/src/corelib/io/qsettings.cpp
+++ b/src/corelib/io/qsettings.cpp
@@ -77,6 +77,10 @@
 #  include <ioLib.h>
 #endif
 
+#ifdef Q_OS_WASM
+#include <emscripten.h>
+#endif
+
 #include <algorithm>
 #include <stdlib.h>
 
@@ -1544,6 +1548,13 @@ void QConfFileSettingsPrivate::syncConfFile(QConfFile *confFile)
                     perms |= QFile::ReadGroup | QFile::ReadOther;
                 QFile(confFile->name).setPermissions(perms);
             }
+#ifdef Q_OS_WASM
+        EM_ASM(
+            // Sync sandbox filesystem to persistent database filesystem. See QTBUG-70002
+            FS.syncfs(false, function(err) {
+            });
+        );
+#endif
         } else {
             setStatus(QSettings::AccessError);
         }
diff --git a/src/corelib/io/qsettings_win.cpp b/src/corelib/io/qsettings_win.cpp
index 43e1411c76..e1922674ef 100644
--- a/src/corelib/io/qsettings_win.cpp
+++ b/src/corelib/io/qsettings_win.cpp
@@ -515,7 +515,7 @@ bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVa
         case REG_SZ: {
             QString s;
             if (dataSize) {
-                s = QString::fromWCharArray(((const wchar_t *)data.constData()));
+                s = QString::fromWCharArray(reinterpret_cast<const wchar_t *>(data.constData()));
             }
             if (value != 0)
                 *value = stringToVariant(s);
@@ -527,7 +527,7 @@ bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVa
             if (dataSize) {
                 int i = 0;
                 for (;;) {
-                    QString s = QString::fromWCharArray((const wchar_t *)data.constData() + i);
+                    QString s = QString::fromWCharArray(reinterpret_cast<const wchar_t *>(data.constData()) + i);
                     i += s.length() + 1;
 
                     if (s.isEmpty())
@@ -544,7 +544,7 @@ bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVa
         case REG_BINARY: {
             QString s;
             if (dataSize) {
-                s = QString::fromWCharArray((const wchar_t *)data.constData(), data.size() / 2);
+                s = QString::fromWCharArray(reinterpret_cast<const wchar_t *>(data.constData()), data.size() / 2);
             }
             if (value != 0)
                 *value = stringToVariant(s);
@@ -555,7 +555,7 @@ bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVa
         case REG_DWORD: {
             Q_ASSERT(data.size() == sizeof(int));
             int i;
-            memcpy((char*)&i, data.constData(), sizeof(int));
+            memcpy(reinterpret_cast<char*>(&i), data.constData(), sizeof(int));
             if (value != 0)
                 *value = i;
             break;
@@ -564,7 +564,7 @@ bool QWinSettingsPrivate::readKey(HKEY parentHandle, const QString &rSubKey, QVa
         case REG_QWORD: {
             Q_ASSERT(data.size() == sizeof(qint64));
             qint64 i;
-            memcpy((char*)&i, data.constData(), sizeof(qint64));
+            memcpy(reinterpret_cast<char*>(&i), data.constData(), sizeof(qint64));
             if (value != 0)
                 *value = i;
             break;
@@ -688,12 +688,12 @@ void QWinSettingsPrivate::set(const QString &uKey, const QVariant &value)
 
             if (type == REG_BINARY) {
                 QString s = variantToString(value);
-                regValueBuff = QByteArray((const char*)s.utf16(), s.length() * 2);
+                regValueBuff = QByteArray(reinterpret_cast<const char*>(s.utf16()), s.length() * 2);
             } else {
                 QStringList::const_iterator it = l.constBegin();
                 for (; it != l.constEnd(); ++it) {
                     const QString &s = *it;
-                    regValueBuff += QByteArray((const char*)s.utf16(), (s.length() + 1) * 2);
+                    regValueBuff += QByteArray(reinterpret_cast<const char*>(s.utf16()), (s.length() + 1) * 2);
                 }
                 regValueBuff.append((char)0);
                 regValueBuff.append((char)0);
@@ -705,7 +705,7 @@ void QWinSettingsPrivate::set(const QString &uKey, const QVariant &value)
         case QVariant::UInt: {
             type = REG_DWORD;
             qint32 i = value.toInt();
-            regValueBuff = QByteArray((const char*)&i, sizeof(qint32));
+            regValueBuff = QByteArray(reinterpret_cast<const char*>(&i), sizeof(qint32));
             break;
         }
 
@@ -713,7 +713,7 @@ void QWinSettingsPrivate::set(const QString &uKey, const QVariant &value)
         case QVariant::ULongLong: {
             type = REG_QWORD;
             qint64 i = value.toLongLong();
-            regValueBuff = QByteArray((const char*)&i, sizeof(qint64));
+            regValueBuff = QByteArray(reinterpret_cast<const char*>(&i), sizeof(qint64));
             break;
         }
 
@@ -725,11 +725,11 @@ void QWinSettingsPrivate::set(const QString &uKey, const QVariant &value)
             // string type. Otherwise we use REG_BINARY.
             QString s = variantToString(value);
             type = s.contains(QChar::Null) ? REG_BINARY : REG_SZ;
-            if (type == REG_BINARY) {
-                regValueBuff = QByteArray((const char*)s.utf16(), s.length() * 2);
-            } else {
-                regValueBuff = QByteArray((const char*)s.utf16(), (s.length() + 1) * 2);
-            }
+            int length = s.length();
+            if (type == REG_SZ)
+                ++length;
+            regValueBuff = QByteArray(reinterpret_cast<const char *>(s.utf16()),
+                                      int(sizeof(wchar_t)) * length);
             break;
         }
     }
diff --git a/src/corelib/kernel/qcore_mac_p.h b/src/corelib/kernel/qcore_mac_p.h
index 8f2714aa12..b14a494296 100644
--- a/src/corelib/kernel/qcore_mac_p.h
+++ b/src/corelib/kernel/qcore_mac_p.h
@@ -59,36 +59,6 @@
 
 // --------------------------------------------------------------------------
 
-#if !defined(QT_BOOTSTRAPPED) && (QT_MACOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__MAC_10_12) || !defined(Q_OS_MACOS))
-#define QT_USE_APPLE_ACTIVITIES
-
-#if defined(OS_ACTIVITY_OBJECT_API)
-#error The file <os/activity.h> has already been included
-#endif
-
-// We runtime-check all use of the activity APIs, so we can safely build
-// with them included, even if the deployment target is macOS 10.11
-#if QT_MACOS_DEPLOYMENT_TARGET_BELOW(__MAC_10_12)
-#undef __MAC_OS_X_VERSION_MIN_REQUIRED
-#define __MAC_OS_X_VERSION_MIN_REQUIRED __MAC_10_12
-#define DID_OVERRIDE_DEPLOYMENT_TARGET
-#endif
-
-#include <os/activity.h>
-#if !OS_ACTIVITY_OBJECT_API
-#error "Expected activity API to be available"
-#endif
-
-#if defined(DID_OVERRIDE_DEPLOYMENT_TARGET)
-#undef __MAC_OS_X_VERSION_MIN_REQUIRED
-#define __MAC_OS_X_VERSION_MIN_REQUIRED __MAC_10_11
-#undef DID_OVERRIDE_DEPLOYMENT_TARGET
-#endif
-
-#endif
-
-// --------------------------------------------------------------------------
-
 #if defined(QT_BOOTSTRAPPED)
 #include <ApplicationServices/ApplicationServices.h>
 #else
@@ -220,41 +190,31 @@ Q_CORE_EXPORT AppleApplication *qt_apple_sharedApplication();
 
 // --------------------------------------------------------------------------
 
-#if !defined(QT_BOOTSTRAPPED) && (QT_MACOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__MAC_10_12) || !defined(Q_OS_MACOS))
+#if !defined(QT_BOOTSTRAPPED)
 #define QT_USE_APPLE_UNIFIED_LOGGING
 
 QT_END_NAMESPACE
 #include <os/log.h>
-
-// The compiler isn't smart enough to realize that we're calling these functions
-// guarded by __builtin_available, so we need to also tag each function with the
-// runtime requirements.
-#include <os/availability.h>
-#define OS_LOG_AVAILABILITY API_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0))
 QT_BEGIN_NAMESPACE
 
 class Q_CORE_EXPORT AppleUnifiedLogger
 {
 public:
     static bool messageHandler(QtMsgType msgType, const QMessageLogContext &context, const QString &message,
-        const QString &subsystem = QString()) OS_LOG_AVAILABILITY;
+        const QString &subsystem = QString());
 private:
-    static os_log_type_t logTypeForMessageType(QtMsgType msgType) OS_LOG_AVAILABILITY;
-    static os_log_t cachedLog(const QString &subsystem, const QString &category) OS_LOG_AVAILABILITY;
+    static os_log_type_t logTypeForMessageType(QtMsgType msgType);
+    static os_log_t cachedLog(const QString &subsystem, const QString &category);
 };
 
-#undef OS_LOG_AVAILABILITY
-
 #endif
 
 // --------------------------------------------------------------------------
 
-#if defined(QT_USE_APPLE_ACTIVITIES)
+#if !defined(QT_BOOTSTRAPPED)
 
 QT_END_NAMESPACE
-#include <os/availability.h>
-#define OS_ACTIVITY_AVAILABILITY API_AVAILABLE(macos(10.12), ios(10.0), tvos(10.0), watchos(3.0))
-#define OS_ACTIVITY_AVAILABILITY_CHECK __builtin_available(macOS 10.12, iOS 10, tvOS 10, watchOS 3, *)
+#include <os/activity.h>
 QT_BEGIN_NAMESPACE
 
 template <typename T> using QAppleOsType = QAppleRefCounted<T, void *, os_retain, os_release>;
@@ -263,7 +223,7 @@ class Q_CORE_EXPORT QAppleLogActivity
 {
 public:
     QAppleLogActivity() : activity(nullptr) {}
-    QAppleLogActivity(os_activity_t activity) OS_ACTIVITY_AVAILABILITY : activity(activity) {}
+    QAppleLogActivity(os_activity_t activity) : activity(activity) {}
     ~QAppleLogActivity() { if (activity) leave(); }
 
     QAppleLogActivity(const QAppleLogActivity &) = delete;
@@ -284,21 +244,17 @@ public:
 
     QAppleLogActivity&& enter()
     {
-        if (activity) {
-            if (OS_ACTIVITY_AVAILABILITY_CHECK)
-                os_activity_scope_enter(static_cast<os_activity_t>(*this), &state);
-        }
+        if (activity)
+            os_activity_scope_enter(static_cast<os_activity_t>(*this), &state);
         return std::move(*this);
     }
 
     void leave() {
-        if (activity) {
-            if (OS_ACTIVITY_AVAILABILITY_CHECK)
-                os_activity_scope_leave(&state);
-        }
+        if (activity)
+            os_activity_scope_leave(&state);
     }
 
-    operator os_activity_t() OS_ACTIVITY_AVAILABILITY
+    operator os_activity_t()
     {
         return reinterpret_cast<os_activity_t>(static_cast<void *>(activity));
     }
@@ -312,9 +268,7 @@ private:
 #define QT_APPLE_LOG_ACTIVITY_CREATE(condition, description, parent) []() { \
         if (!(condition)) \
             return QAppleLogActivity(); \
-        if (OS_ACTIVITY_AVAILABILITY_CHECK) \
-            return QAppleLogActivity(os_activity_create(description, parent, OS_ACTIVITY_FLAG_DEFAULT)); \
-        return QAppleLogActivity(); \
+        return QAppleLogActivity(os_activity_create(description, parent, OS_ACTIVITY_FLAG_DEFAULT)); \
     }()
 
 #define QT_VA_ARGS_CHOOSE(_1, _2, _3, _4, _5, _6, _7, _8, _9, N, ...) N
@@ -335,12 +289,7 @@ QT_MAC_WEAK_IMPORT(_os_activity_current);
 
 #define QT_APPLE_SCOPED_LOG_ACTIVITY(...) QAppleLogActivity scopedLogActivity = QT_APPLE_LOG_ACTIVITY(__VA_ARGS__).enter();
 
-#else
-// No-ops for macOS 10.11. We don't need to provide QT_APPLE_SCOPED_LOG_ACTIVITY,
-// as all the call sites for that are in code that's only built on 10.12 and above.
-#define QT_APPLE_LOG_ACTIVITY_WITH_PARENT(...)
-#define QT_APPLE_LOG_ACTIVITY(...)
-#endif // QT_DARWIN_PLATFORM_SDK_EQUAL_OR_ABOVE
+#endif // !defined(QT_BOOTSTRAPPED)
 
 // -------------------------------------------------------------------------
 
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 0303916c11..1350a7aa94 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -118,6 +118,10 @@
 #  include <taskLib.h>
 #endif
 
+#ifdef Q_OS_WASM
+#include <emscripten.h>
+#endif
+
 #ifdef QT_BOOTSTRAPPED
 #include <private/qtrace_p.h>
 #else
@@ -486,6 +490,13 @@ QCoreApplicationPrivate::QCoreApplicationPrivate(int &aargc, char **aargv, uint
 
 QCoreApplicationPrivate::~QCoreApplicationPrivate()
 {
+#ifdef Q_OS_WASM
+    EM_ASM(
+        // unmount persistent directory as IDBFS
+        // see also QTBUG-70002
+        FS.unmount('/home/web_user');
+    );
+#endif
 #ifndef QT_NO_QOBJECT
     cleanupThreadData();
 #endif
@@ -777,6 +788,17 @@ void QCoreApplicationPrivate::init()
     Q_ASSERT_X(!QCoreApplication::self, "QCoreApplication", "there should be only one application object");
     QCoreApplication::self = q;
 
+#ifdef Q_OS_WASM
+    EM_ASM(
+        // mount and sync persistent filesystem to sandbox
+        FS.mount(IDBFS, {}, '/home/web_user');
+        FS.syncfs(true, function(err) {
+            if (err)
+                Module.print(err);
+        });
+    );
+#endif
+
     // Store app name/version (so they're still available after QCoreApplication is destroyed)
     if (!coreappdata()->applicationNameSet)
         coreappdata()->application = appName();
diff --git a/src/corelib/kernel/qeventdispatcher_unix.cpp b/src/corelib/kernel/qeventdispatcher_unix.cpp
index a28f2e3f0a..535f86fefe 100644
--- a/src/corelib/kernel/qeventdispatcher_unix.cpp
+++ b/src/corelib/kernel/qeventdispatcher_unix.cpp
@@ -130,7 +130,7 @@ static void initThreadPipeFD(int fd)
 
 bool QThreadPipe::init()
 {
-#if defined(Q_OS_NACL)
+#if defined(Q_OS_NACL) || defined(Q_OS_WASM)
    // do nothing.
 #elif defined(Q_OS_VXWORKS)
     qsnprintf(name, sizeof(name), "/pipe/qt_%08x", int(taskIdSelf()));
diff --git a/src/corelib/kernel/qeventdispatcher_win.cpp b/src/corelib/kernel/qeventdispatcher_win.cpp
index f1a4088d98..2862f42b2b 100644
--- a/src/corelib/kernel/qeventdispatcher_win.cpp
+++ b/src/corelib/kernel/qeventdispatcher_win.cpp
@@ -120,7 +120,7 @@ void WINAPI QT_WIN_CALLBACK qt_fast_timer_proc(uint timerId, uint /*reserved*/,
 {
     if (!timerId) // sanity check
         return;
-    WinTimerInfo *t = (WinTimerInfo*)user;
+    auto t = reinterpret_cast<WinTimerInfo*>(user);
     Q_ASSERT(t);
     QCoreApplication::postEvent(t->dispatcher, new QTimerEvent(t->timerId));
 }
@@ -146,9 +146,9 @@ LRESULT QT_WIN_CALLBACK qt_internal_proc(HWND hwnd, UINT message, WPARAM wp, LPA
     }
 
 #ifdef GWLP_USERDATA
-    QEventDispatcherWin32 *q = (QEventDispatcherWin32 *) GetWindowLongPtr(hwnd, GWLP_USERDATA);
+    auto q = reinterpret_cast<QEventDispatcherWin32 *>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
 #else
-    QEventDispatcherWin32 *q = (QEventDispatcherWin32 *) GetWindowLong(hwnd, GWL_USERDATA);
+    auto q = reinterpret_cast<QEventDispatcherWin32 *>(GetWindowLong(hwnd, GWL_USERDATA));
 #endif
     QEventDispatcherWin32Private *d = 0;
     if (q != 0)
@@ -369,9 +369,9 @@ static HWND qt_create_internal_window(const QEventDispatcherWin32 *eventDispatch
     }
 
 #ifdef GWLP_USERDATA
-    SetWindowLongPtr(wnd, GWLP_USERDATA, (LONG_PTR)eventDispatcher);
+    SetWindowLongPtr(wnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(eventDispatcher));
 #else
-    SetWindowLong(wnd, GWL_USERDATA, (LONG)eventDispatcher);
+    SetWindowLong(wnd, GWL_USERDATA, reinterpret_cast<LONG>(eventDispatcher));
 #endif
 
     return wnd;
@@ -603,7 +603,7 @@ bool QEventDispatcherWin32::processEvents(QEventLoop::ProcessEventsFlags flags)
             if (haveMessage) {
                 // WinCE doesn't support hooks at all, so we have to call this by hand :(
                 if (!d->getMessageHook)
-                    (void) qt_GetMessageHook(0, PM_REMOVE, (LPARAM) &msg);
+                    (void) qt_GetMessageHook(0, PM_REMOVE, reinterpret_cast<LPARAM>(&msg));
 
                 if (d->internalHwnd == msg.hwnd && msg.message == WM_QT_SENDPOSTEDEVENTS) {
                     if (seenWM_QT_SENDPOSTEDEVENTS) {
diff --git a/src/corelib/kernel/qeventloop.cpp b/src/corelib/kernel/qeventloop.cpp
index f1d32b15d1..a6cc51621a 100644
--- a/src/corelib/kernel/qeventloop.cpp
+++ b/src/corelib/kernel/qeventloop.cpp
@@ -48,6 +48,10 @@
 #include "qeventloop_p.h"
 #include <private/qthread_p.h>
 
+#ifdef Q_OS_WASM
+#include <emscripten.h>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -208,6 +212,15 @@ int QEventLoop::exec(ProcessEventsFlags flags)
     if (app && app->thread() == thread())
         QCoreApplication::removePostedEvents(app, QEvent::Quit);
 
+#ifdef Q_OS_WASM
+    // Partial support for nested event loops: Make the runtime throw a JavaSrcript
+    // exception, which returns control to the browser while preserving the C++ stack.
+    // Event processing then continues as normal. The sleep call below never returns.
+    // QTBUG-70185
+    if (d->threadData->loopLevel > 1)
+        emscripten_sleep(1);
+#endif
+
     while (!d->exit.loadAcquire())
         processEvents(flags | WaitForMoreEvents | EventLoopExec);
 
@@ -269,6 +282,17 @@ void QEventLoop::exit(int returnCode)
     d->returnCode.store(returnCode);
     d->exit.storeRelease(true);
     d->threadData->eventDispatcher.load()->interrupt();
+
+#ifdef Q_OS_WASM
+    // QEventLoop::exec() never returns in emscripten. We implement approximate behavior here.
+    // QTBUG-70185
+    if (d->threadData->loopLevel == 1) {
+        emscripten_force_exit(returnCode);
+    } else {
+        d->inExec = false;
+        --d->threadData->loopLevel;
+    }
+#endif
 }
 
 /*!
diff --git a/src/corelib/kernel/qmetaobject_p.h b/src/corelib/kernel/qmetaobject_p.h
index 4df9a8de77..522bd78e42 100644
--- a/src/corelib/kernel/qmetaobject_p.h
+++ b/src/corelib/kernel/qmetaobject_p.h
@@ -60,6 +60,8 @@
 #include <QtCore/qvarlengtharray.h>
 
 QT_BEGIN_NAMESPACE
+// ### TODO Qt6: add a proper namespace with Q_NAMESPACE and use scoped enums
+// A namespace and scoped are needed to avoid enum clashes
 
 enum PropertyFlags  {
     Invalid = 0x00000000,
@@ -103,7 +105,7 @@ enum MethodFlags  {
     MethodRevisioned = 0x80
 };
 
-enum MetaObjectFlags {
+enum MetaObjectFlags { // keep it in sync with QMetaObjectBuilder::MetaObjectFlag enum
     DynamicMetaObject = 0x01,
     RequiresVariantMetaObject = 0x02,
     PropertyAccessInStaticMetaCall = 0x04 // since Qt 5.5, property code is in the static metacall
diff --git a/src/corelib/kernel/qmetaobjectbuilder_p.h b/src/corelib/kernel/qmetaobjectbuilder_p.h
index 781d206e0b..115ec835aa 100644
--- a/src/corelib/kernel/qmetaobjectbuilder_p.h
+++ b/src/corelib/kernel/qmetaobjectbuilder_p.h
@@ -93,8 +93,11 @@ public:
     };
     Q_DECLARE_FLAGS(AddMembers, AddMember)
 
-    enum MetaObjectFlag {
-        DynamicMetaObject = 0x01
+    // ### TODO Qt6: remove me and use the MetaObjectFlags enum from qmetaobject_p.h
+    enum MetaObjectFlag { // keep it in sync with enum MetaObjectFlags from qmetaobject_p.h
+        DynamicMetaObject = 0x01,
+        RequiresVariantMetaObject = 0x02,
+        PropertyAccessInStaticMetaCall = 0x04 // since Qt 5.5, property code is in the static metacall
     };
     Q_DECLARE_FLAGS(MetaObjectFlags, MetaObjectFlag)
 
diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 76e3d0d014..82952919dd 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -1054,45 +1054,40 @@ int QMetaType::registerType(const char *typeName, Deleter deleter,
     return registerNormalizedType(normalizedTypeName, deleter, creator, destructor, constructor, size, flags, metaObject);
 }
 
-
 /*!
-  \internal
-  \since 5.0
-  \overload
-  Don't use, kept for binary compatibility
+    \internal
+    \since 5.12
 
-  ### TODO Qt6: remove me
-*/
-int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName, Deleter deleter,
-                            Creator creator,
-                            Destructor destructor,
-                            Constructor constructor,
-                            int size, TypeFlags flags, const QMetaObject *metaObject)
+    Registers a user type for marshalling, with \a typeName, a \a
+    \a destructor, a \a constructor, and a \a size. Returns the
+    type's handle, or -1 if the type could not be registered.
+ */
+int QMetaType::registerType(const char *typeName,
+                            TypedDestructor destructor,
+                            TypedConstructor constructor,
+                            int size,
+                            TypeFlags flags,
+                            const QMetaObject *metaObject)
 {
-    Q_UNUSED(deleter);
-    Q_UNUSED(creator);
+#ifdef QT_NO_QOBJECT
+    NS(QByteArray) normalizedTypeName = typeName;
+#else
+    NS(QByteArray) normalizedTypeName = QMetaObject::normalizedType(typeName);
+#endif
+
     return registerNormalizedType(normalizedTypeName, destructor, constructor, size, flags, metaObject);
 }
 
 
-/*!
-    \internal
-    \since 5.5
-
-    Registers a user type for marshalling, with \a normalizedTypeName,
-    a \a destructor, a \a constructor, and a \a size. Returns the type's
-    handle, or -1 if the type could not be registered.
-
-    \note normalizedTypeName is not checked for conformance with
-    Qt's normalized format, so it must already conform.
- */
-int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
-                            Destructor destructor,
-                            Constructor constructor,
-                            int size, TypeFlags flags, const QMetaObject *metaObject)
+static int registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
+                                  QMetaType::Destructor destructor,
+                                  QMetaType::Constructor constructor,
+                                  QMetaType::TypedDestructor typedDestructor,
+                                  QMetaType::TypedConstructor typedConstructor,
+                                  int size, QMetaType::TypeFlags flags, const QMetaObject *metaObject)
 {
     QVector<QCustomTypeInfo> *ct = customTypes();
-    if (!ct || normalizedTypeName.isEmpty() || !destructor || !constructor)
+    if (!ct || normalizedTypeName.isEmpty() || (!destructor && !typedDestructor) || (!constructor && !typedConstructor))
         return -1;
 
     int idx = qMetaTypeStaticType(normalizedTypeName.constData(),
@@ -1100,13 +1095,13 @@ int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
 
     int previousSize = 0;
     QMetaType::TypeFlags::Int previousFlags = 0;
-    if (idx == UnknownType) {
+    if (idx == QMetaType::UnknownType) {
         QWriteLocker locker(customTypesLock());
         int posInVector = -1;
         idx = qMetaTypeCustomType_unlocked(normalizedTypeName.constData(),
                                            normalizedTypeName.size(),
                                            &posInVector);
-        if (idx == UnknownType) {
+        if (idx == QMetaType::UnknownType) {
             QCustomTypeInfo inf;
             inf.typeName = normalizedTypeName;
 #ifndef QT_NO_DATASTREAM
@@ -1114,30 +1109,32 @@ int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
             inf.saveOp = 0;
 #endif
             inf.alias = -1;
+            inf.typedConstructor = typedConstructor;
+            inf.typedDestructor = typedDestructor;
             inf.constructor = constructor;
             inf.destructor = destructor;
             inf.size = size;
             inf.flags = flags;
             inf.metaObject = metaObject;
             if (posInVector == -1) {
-                idx = ct->size() + User;
+                idx = ct->size() + QMetaType::User;
                 ct->append(inf);
             } else {
-                idx = posInVector + User;
+                idx = posInVector + QMetaType::User;
                 ct->data()[posInVector] = inf;
             }
             return idx;
         }
 
-        if (idx >= User) {
-            previousSize = ct->at(idx - User).size;
-            previousFlags = ct->at(idx - User).flags;
+        if (idx >= QMetaType::User) {
+            previousSize = ct->at(idx - QMetaType::User).size;
+            previousFlags = ct->at(idx - QMetaType::User).flags;
 
             // Set new/additional flags in case of old library/app.
             // Ensures that older code works in conjunction with new Qt releases
             // requiring the new flags.
             if (flags != previousFlags) {
-                QCustomTypeInfo &inf = ct->data()[idx - User];
+                QCustomTypeInfo &inf = ct->data()[idx - QMetaType::User];
                 inf.flags |= flags;
                 if (metaObject)
                     inf.metaObject = metaObject;
@@ -1145,7 +1142,7 @@ int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
         }
     }
 
-    if (idx < User) {
+    if (idx < QMetaType::User) {
         previousSize = QMetaType::sizeOf(idx);
         previousFlags = QMetaType::typeFlags(idx);
     }
@@ -1158,8 +1155,8 @@ int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
     }
 
     // these flags cannot change in a binary compatible way:
-    const int binaryCompatibilityFlag = PointerToQObject | IsEnumeration | SharedPointerToQObject
-                                                | WeakPointerToQObject | TrackingPointerToQObject;
+    const int binaryCompatibilityFlag = QMetaType::PointerToQObject | QMetaType::IsEnumeration | QMetaType::SharedPointerToQObject
+                                                | QMetaType::WeakPointerToQObject | QMetaType::TrackingPointerToQObject;
     if (Q_UNLIKELY((previousFlags ^ flags) & binaryCompatibilityFlag)) {
 
         const char *msg = "QMetaType::registerType: Binary compatibility break. "
@@ -1173,6 +1170,66 @@ int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
 }
 
 /*!
+  \internal
+  \since 5.0
+  \overload
+  Don't use, kept for binary compatibility
+
+  ### TODO Qt6: remove me
+*/
+int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName, Deleter deleter,
+                            Creator creator,
+                            Destructor destructor,
+                            Constructor constructor,
+                            int size, TypeFlags flags, const QMetaObject *metaObject)
+{
+    Q_UNUSED(deleter);
+    Q_UNUSED(creator);
+    return registerNormalizedType(normalizedTypeName, destructor, constructor, size, flags, metaObject);
+}
+
+
+/*!
+    \internal
+    \since 5.5
+
+    Registers a user type for marshalling, with \a normalizedTypeName,
+    a \a destructor, a \a constructor, and a \a size. Returns the type's
+    handle, or -1 if the type could not be registered.
+
+    \note normalizedTypeName is not checked for conformance with
+    Qt's normalized format, so it must already conform.
+
+    ### TODO Qt6: remove me
+ */
+int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
+                            Destructor destructor,
+                            Constructor constructor,
+                            int size, TypeFlags flags, const QMetaObject *metaObject)
+{
+    return NS(registerNormalizedType)(normalizedTypeName, destructor, constructor, nullptr, nullptr, size, flags, metaObject);
+}
+
+/*!
+    \internal
+    \since 5.12
+
+    Registers a user type for marshalling, with \a normalizedTypeName,
+    a \a destructor, a \a constructor, and a \a size. Returns the type's
+    handle, or -1 if the type could not be registered.
+
+    \note normalizedTypeName is not checked for conformance with
+    Qt's normalized format, so it must already conform.
+ */
+int QMetaType::registerNormalizedType(const NS(QByteArray) &normalizedTypeName,
+                            TypedDestructor destructor,
+                            TypedConstructor constructor,
+                            int size, TypeFlags flags, const QMetaObject *metaObject)
+{
+    return NS(registerNormalizedType)(normalizedTypeName, nullptr, nullptr, destructor, constructor, size, flags, metaObject);
+}
+
+/*!
     \internal
     \since 4.7
 
@@ -1850,14 +1907,19 @@ private:
     static void *customTypeConstructor(const int type, void *where, const void *copy)
     {
         QMetaType::Constructor ctor;
+        QMetaType::TypedConstructor tctor;
         const QVector<QCustomTypeInfo> * const ct = customTypes();
         {
             QReadLocker locker(customTypesLock());
             if (Q_UNLIKELY(type < QMetaType::User || !ct || ct->count() <= type - QMetaType::User))
                 return 0;
-            ctor = ct->at(type - QMetaType::User).constructor;
+            const auto &typeInfo = ct->at(type - QMetaType::User);
+            ctor = typeInfo.constructor;
+            tctor = typeInfo.typedConstructor;
         }
-        Q_ASSERT_X(ctor, "void *QMetaType::construct(int type, void *where, const void *copy)", "The type was not properly registered");
+        Q_ASSERT_X((ctor || tctor) , "void *QMetaType::construct(int type, void *where, const void *copy)", "The type was not properly registered");
+        if (Q_UNLIKELY(tctor))
+            return tctor(type, where, copy);
         return ctor(where, copy);
     }
 
@@ -1943,14 +2005,19 @@ private:
     static void customTypeDestructor(const int type, void *where)
     {
         QMetaType::Destructor dtor;
+        QMetaType::TypedDestructor tdtor;
         const QVector<QCustomTypeInfo> * const ct = customTypes();
         {
             QReadLocker locker(customTypesLock());
             if (Q_UNLIKELY(type < QMetaType::User || !ct || ct->count() <= type - QMetaType::User))
                 return;
-            dtor = ct->at(type - QMetaType::User).destructor;
+            const auto &typeInfo = ct->at(type - QMetaType::User);
+            dtor = typeInfo.destructor;
+            tdtor = typeInfo.typedDestructor;
         }
-        Q_ASSERT_X(dtor, "void QMetaType::destruct(int type, void *where)", "The type was not properly registered");
+        Q_ASSERT_X((dtor || tdtor), "void QMetaType::destruct(int type, void *where)", "The type was not properly registered");
+        if (Q_UNLIKELY(tdtor))
+            return tdtor(type, where);
         dtor(where);
     }
 
@@ -2363,10 +2430,12 @@ QMetaType QMetaType::typeInfo(const int type)
 {
     TypeInfo typeInfo(type);
     QMetaTypeSwitcher::switcher<void>(typeInfo, type, 0);
-    return typeInfo.info.constructor ? QMetaType(static_cast<ExtensionFlag>(QMetaType::CreateEx | QMetaType::DestroyEx)
-                                 , static_cast<const QMetaTypeInterface *>(0) // typeInfo::info is a temporary variable, we can't return address of it.
-                                 , 0 // unused
-                                 , 0 // unused
+    return (typeInfo.info.constructor || typeInfo.info.typedConstructor)
+                ? QMetaType(static_cast<ExtensionFlag>(QMetaType::CreateEx | QMetaType::DestroyEx |
+                                                       (typeInfo.info.typedConstructor ? QMetaType::ConstructEx | QMetaType::DestructEx : 0))
+                                 , static_cast<const QMetaTypeInterface *>(nullptr) // typeInfo::info is a temporary variable, we can't return address of it.
+                                 , typeInfo.info.typedConstructor
+                                 , typeInfo.info.typedDestructor
                                  , typeInfo.info.saveOp
                                  , typeInfo.info.loadOp
                                  , typeInfo.info.constructor
@@ -2408,8 +2477,8 @@ QMetaType::QMetaType(const int typeId)
      Copy constructs a QMetaType object.
 */
 QMetaType::QMetaType(const QMetaType &other)
-    : m_creator_unused(other.m_creator_unused)
-    , m_deleter_unused(other.m_deleter_unused)
+    : m_typedConstructor(other.m_typedConstructor)
+    , m_typedDestructor(other.m_typedDestructor)
     , m_saveOp(other.m_saveOp)
     , m_loadOp(other.m_loadOp)
     , m_constructor(other.m_constructor)
@@ -2424,8 +2493,8 @@ QMetaType::QMetaType(const QMetaType &other)
 
 QMetaType &QMetaType::operator =(const QMetaType &other)
 {
-    m_creator_unused = other.m_creator_unused;
-    m_deleter_unused = other.m_deleter_unused;
+    m_typedConstructor = other.m_typedConstructor;
+    m_typedDestructor = other.m_typedDestructor;
     m_saveOp = other.m_saveOp;
     m_loadOp = other.m_loadOp;
     m_constructor = other.m_constructor;
@@ -2481,6 +2550,8 @@ void *QMetaType::createExtended(const void *copy) const
 {
     if (m_typeId == QMetaType::UnknownType)
         return 0;
+    if (Q_UNLIKELY(m_typedConstructor && !m_constructor))
+        return m_typedConstructor(m_typeId, operator new(m_size), copy);
     return m_constructor(operator new(m_size), copy);
 }
 
@@ -2495,7 +2566,10 @@ void *QMetaType::createExtended(const void *copy) const
 */
 void QMetaType::destroyExtended(void *data) const
 {
-    m_destructor(data);
+    if (Q_UNLIKELY(m_typedDestructor && !m_destructor))
+        m_typedDestructor(m_typeId, data);
+    else
+        m_destructor(data);
     operator delete(data);
 }
 
@@ -2508,9 +2582,9 @@ void QMetaType::destroyExtended(void *data) const
 */
 void *QMetaType::constructExtended(void *where, const void *copy) const
 {
-    Q_UNUSED(where);
-    Q_UNUSED(copy);
-    return 0;
+    if (m_typedConstructor && !m_constructor)
+        return m_typedConstructor(m_typeId, where, copy);
+    return nullptr;
 }
 
 /*!
@@ -2522,7 +2596,8 @@ void *QMetaType::constructExtended(void *where, const void *copy) const
 */
 void QMetaType::destructExtended(void *data) const
 {
-    Q_UNUSED(data);
+    if (m_typedDestructor && !m_destructor)
+        m_typedDestructor(m_typeId, data);
 }
 
 /*!
diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 48cbe7f00b..ed7feee775 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -493,8 +493,12 @@ public:
     typedef void (*Deleter)(void *);
     typedef void *(*Creator)(const void *);
 
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     typedef void (*Destructor)(void *);
-    typedef void *(*Constructor)(void *, const void *);
+    typedef void *(*Constructor)(void *, const void *); // TODO Qt6: remove me
+#endif
+    typedef void (*TypedDestructor)(int, void *);
+    typedef void *(*TypedConstructor)(int, void *, const void *);
 
     typedef void (*SaveOperator)(QDataStream &, const void *);
     typedef void (*LoadOperator)(QDataStream &, void *);
@@ -513,6 +517,12 @@ public:
                             int size,
                             QMetaType::TypeFlags flags,
                             const QMetaObject *metaObject);
+    static int registerType(const char *typeName,
+                            TypedDestructor destructor,
+                            TypedConstructor constructor,
+                            int size,
+                            QMetaType::TypeFlags flags,
+                            const QMetaObject *metaObject);
     static bool unregisterType(int type);
     static int registerNormalizedType(const QT_PREPEND_NAMESPACE(QByteArray) &normalizedTypeName, Deleter deleter,
                             Creator creator,
@@ -526,6 +536,11 @@ public:
                             int size,
                             QMetaType::TypeFlags flags,
                             const QMetaObject *metaObject);
+    static int registerNormalizedType(const QT_PREPEND_NAMESPACE(QByteArray) &normalizedTypeName, TypedDestructor destructor,
+                            TypedConstructor constructor,
+                            int size,
+                            QMetaType::TypeFlags flags,
+                            const QMetaObject *metaObject);
     static int registerTypedef(const char *typeName, int aliasId);
     static int registerNormalizedTypedef(const QT_PREPEND_NAMESPACE(QByteArray) &normalizedTypeName, int aliasId);
     static int type(const char *typeName);
@@ -683,8 +698,8 @@ public:
 private:
     static QMetaType typeInfo(const int type);
     inline QMetaType(const ExtensionFlag extensionFlags, const QMetaTypeInterface *info,
-                     Creator creator,
-                     Deleter deleter,
+                     TypedConstructor creator,
+                     TypedDestructor deleter,
                      SaveOperator saveOp,
                      LoadOperator loadOp,
                      Constructor constructor,
@@ -731,8 +746,8 @@ public:
     static void unregisterConverterFunction(int from, int to);
 private:
 
-    Creator m_creator_unused;
-    Deleter m_deleter_unused;
+    TypedConstructor m_typedConstructor;
+    TypedDestructor m_typedDestructor;
     SaveOperator m_saveOp;
     LoadOperator m_loadOp;
     Constructor m_constructor;
@@ -2163,8 +2178,8 @@ QT_BEGIN_NAMESPACE
 #undef Q_DECLARE_METATYPE_TEMPLATE_SMART_POINTER_ITER
 
 inline QMetaType::QMetaType(const ExtensionFlag extensionFlags, const QMetaTypeInterface *info,
-                            Creator creator,
-                            Deleter deleter,
+                            TypedConstructor creator,
+                            TypedDestructor deleter,
                             SaveOperator saveOp,
                             LoadOperator loadOp,
                             Constructor constructor,
@@ -2173,8 +2188,8 @@ inline QMetaType::QMetaType(const ExtensionFlag extensionFlags, const QMetaTypeI
                             uint theTypeFlags,
                             int typeId,
                             const QMetaObject *_metaObject)
-    : m_creator_unused(creator)
-    , m_deleter_unused(deleter)
+    : m_typedConstructor(creator)
+    , m_typedDestructor(deleter)
     , m_saveOp(saveOp)
     , m_loadOp(loadOp)
     , m_constructor(constructor)
diff --git a/src/corelib/kernel/qmetatype_p.h b/src/corelib/kernel/qmetatype_p.h
index 76f43db8d7..94e9228778 100644
--- a/src/corelib/kernel/qmetatype_p.h
+++ b/src/corelib/kernel/qmetatype_p.h
@@ -126,11 +126,13 @@ class QMetaTypeInterface
 public:
     QMetaType::SaveOperator saveOp;
     QMetaType::LoadOperator loadOp;
-    QMetaType::Constructor constructor;
+    QMetaType::Constructor constructor; // TODO Qt6: remove me
     QMetaType::Destructor destructor;
     int size;
     QMetaType::TypeFlags::Int flags;
     const QMetaObject *metaObject;
+    QMetaType::TypedConstructor typedConstructor;
+    QMetaType::TypedDestructor typedDestructor;
 };
 
 #ifndef QT_NO_DATASTREAM
@@ -161,7 +163,9 @@ public:
     /*destructor*/(QtMetaTypePrivate::QMetaTypeFunctionHelper<Type, QtMetaTypePrivate::TypeDefinition<Type>::IsAvailable>::Destruct), \
     /*size*/(QTypeInfo<Type>::sizeOf), \
     /*flags*/QtPrivate::QMetaTypeTypeFlags<Type>::Flags, \
-    /*metaObject*/METAOBJECT_DELEGATE(Type) \
+    /*metaObject*/METAOBJECT_DELEGATE(Type), \
+    /*typedConstructor*/ nullptr, \
+    /*typedDestructor*/ nullptr \
 }
 
 
@@ -184,7 +188,9 @@ public:
     /*destructor*/ 0, \
     /*size*/ 0, \
     /*flags*/ 0, \
-    /*metaObject*/ 0 \
+    /*metaObject*/ 0 , \
+    /*typedConstructor*/ nullptr, \
+    /*typedDestructor*/ nullptr \
 }
 
 namespace QtMetaTypePrivate {
diff --git a/src/corelib/kernel/qsharedmemory_win.cpp b/src/corelib/kernel/qsharedmemory_win.cpp
index be42a369c2..467398e039 100644
--- a/src/corelib/kernel/qsharedmemory_win.cpp
+++ b/src/corelib/kernel/qsharedmemory_win.cpp
@@ -101,7 +101,8 @@ HANDLE QSharedMemoryPrivate::handle()
 #if defined(Q_OS_WINRT)
         hand = OpenFileMappingFromApp(FILE_MAP_ALL_ACCESS, FALSE, reinterpret_cast<PCWSTR>(nativeKey.utf16()));
 #else
-        hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false, (wchar_t*)nativeKey.utf16());
+        hand = OpenFileMapping(FILE_MAP_ALL_ACCESS, false,
+                               reinterpret_cast<const wchar_t*>(nativeKey.utf16()));
 #endif
         if (!hand) {
             setErrorString(function);
@@ -133,9 +134,11 @@ bool QSharedMemoryPrivate::create(int size)
 
     // Create the file mapping.
 #if defined(Q_OS_WINRT)
-    hand = CreateFileMappingFromApp(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, size, (PCWSTR)nativeKey.utf16());
+    hand = CreateFileMappingFromApp(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, size,
+                                    reinterpret_cast<PCWSTR>(nativeKey.utf16()));
 #else
-    hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size, (wchar_t*)nativeKey.utf16());
+    hand = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, size,
+                             reinterpret_cast<const wchar_t*>(nativeKey.utf16()));
 #endif
     setErrorString(function);
 
diff --git a/src/corelib/kernel/qsystemsemaphore_win.cpp b/src/corelib/kernel/qsystemsemaphore_win.cpp
index 3395f5641e..2b35803291 100644
--- a/src/corelib/kernel/qsystemsemaphore_win.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_win.cpp
@@ -86,9 +86,12 @@ HANDLE QSystemSemaphorePrivate::handle(QSystemSemaphore::AccessMode)
     // Create it if it doesn't already exists.
     if (semaphore == 0) {
 #if defined(Q_OS_WINRT)
-        semaphore = CreateSemaphoreEx(0, initialValue, MAXLONG, (wchar_t*)fileName.utf16(), 0, SEMAPHORE_ALL_ACCESS);
+        semaphore = CreateSemaphoreEx(0, initialValue, MAXLONG,
+                                      reinterpret_cast<const wchar_t*>(fileName.utf16()),
+                                      0, SEMAPHORE_ALL_ACCESS);
 #else
-        semaphore = CreateSemaphore(0, initialValue, MAXLONG, (wchar_t*)fileName.utf16());
+        semaphore = CreateSemaphore(0, initialValue, MAXLONG,
+                                    reinterpret_cast<const wchar_t*>(fileName.utf16()));
 #endif
         if (semaphore == NULL)
             setErrorString(QLatin1String("QSystemSemaphore::handle"));
diff --git a/src/corelib/mimetypes/qmimedatabase.cpp b/src/corelib/mimetypes/qmimedatabase.cpp
index a58698af53..10b5c8eafd 100644
--- a/src/corelib/mimetypes/qmimedatabase.cpp
+++ b/src/corelib/mimetypes/qmimedatabase.cpp
@@ -151,7 +151,9 @@ void QMimeDatabasePrivate::loadProviders()
 
 QVector<QMimeProviderBase *> QMimeDatabasePrivate::providers()
 {
+#ifndef Q_OS_WASM // stub implementation always returns true
     Q_ASSERT(!mutex.tryLock()); // caller should have locked mutex
+#endif
     if (m_providers.isEmpty()) {
         loadProviders();
         m_lastCheck.start();
diff --git a/src/corelib/plugin/plugin.pri b/src/corelib/plugin/plugin.pri
index a0e0d76044..13153e8d0a 100644
--- a/src/corelib/plugin/plugin.pri
+++ b/src/corelib/plugin/plugin.pri
@@ -4,6 +4,7 @@ HEADERS += \
     plugin/qfactoryinterface.h \
     plugin/qpluginloader.h \
     plugin/qplugin.h \
+    plugin/qplugin_p.h \
     plugin/quuid.h \
     plugin/qfactoryloader_p.h
 
diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp
index 0b35f41ca3..35c64180d4 100644
--- a/src/corelib/plugin/qfactoryloader.cpp
+++ b/src/corelib/plugin/qfactoryloader.cpp
@@ -47,9 +47,12 @@
 #include <qdebug.h>
 #include "qmutex.h"
 #include "qplugin.h"
+#include "qplugin_p.h"
 #include "qpluginloader.h"
 #include "private/qobject_p.h"
 #include "private/qcoreapplication_p.h"
+#include "qcbormap.h"
+#include "qcborvalue.h"
 #include "qjsondocument.h"
 #include "qjsonvalue.h"
 #include "qjsonobject.h"
@@ -64,22 +67,86 @@ static inline int metaDataSignatureLength()
     return sizeof("QTMETADATA  ") - 1;
 }
 
-QJsonDocument qJsonFromRawLibraryMetaData(const char *raw, qsizetype sectionSize)
+static QJsonDocument jsonFromCborMetaData(const char *raw, qsizetype size, QString *errMsg)
+{
+    // extract the keys not stored in CBOR
+    int qt_metadataVersion = quint8(raw[0]);
+    int qt_version = qFromBigEndian<quint16>(raw + 1);
+    int qt_archRequirements = quint8(raw[3]);
+    if (Q_UNLIKELY(raw[-1] != '!' || qt_metadataVersion != 0)) {
+        *errMsg = QStringLiteral("Invalid metadata version");
+        return QJsonDocument();
+    }
+
+    raw += 4;
+    size -= 4;
+    QByteArray ba = QByteArray::fromRawData(raw, int(size));
+    QCborParserError err;
+    QCborValue metadata = QCborValue::fromCbor(ba, &err);
+
+    if (err.error != QCborError::NoError) {
+        *errMsg = QLatin1String("Metadata parsing error: ") + err.error.toString();
+        return QJsonDocument();
+    }
+
+    if (!metadata.isMap()) {
+        *errMsg = QStringLiteral("Unexpected metadata contents");
+        return QJsonDocument();
+    }
+
+    QJsonObject o;
+    o.insert(QLatin1String("version"), qt_version << 8);
+    o.insert(QLatin1String("debug"), bool(qt_archRequirements & 1));
+    o.insert(QLatin1String("archreq"), qt_archRequirements);
+
+    // convert the top-level map integer keys
+    for (auto it : metadata.toMap()) {
+        QString key;
+        if (it.first.isInteger()) {
+            switch (it.first.toInteger()) {
+#define CONVERT_TO_STRING(IntKey, StringKey, Description) \
+            case int(IntKey): key = QStringLiteral(StringKey); break;
+                QT_PLUGIN_FOREACH_METADATA(CONVERT_TO_STRING)
+#undef CONVERT_TO_STRING
+
+            case int(QtPluginMetaDataKeys::Requirements):
+                // special case: recreate the debug key
+                o.insert(QLatin1String("debug"), bool(it.second.toInteger() & 1));
+                key = QStringLiteral("archreq");
+                break;
+            }
+        } else {
+            key = it.first.toString();
+        }
+
+        if (!key.isEmpty())
+            o.insert(key, it.second.toJsonValue());
+    }
+    return QJsonDocument(o);
+}
+
+QJsonDocument qJsonFromRawLibraryMetaData(const char *raw, qsizetype sectionSize, QString *errMsg)
 {
     raw += metaDataSignatureLength();
     sectionSize -= metaDataSignatureLength();
 
-    // the size of the embedded JSON object can be found 8 bytes into the data (see qjson_p.h)
-    uint size = qFromLittleEndian<uint>(raw + 8);
-    // but the maximum size of binary JSON is 128 MB
-    size = qMin(size, 128U * 1024 * 1024);
-    // and it doesn't include the size of the header (8 bytes)
-    size += 8;
-    // finally, it can't be bigger than the file or section size
-    size = qMin(sectionSize, qsizetype(size));
-
-    QByteArray json(raw, size);
-    return QJsonDocument::fromBinaryData(json);
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    if (Q_UNLIKELY(raw[-1] == ' ')) {
+        // the size of the embedded JSON object can be found 8 bytes into the data (see qjson_p.h)
+        uint size = qFromLittleEndian<uint>(raw + 8);
+        // but the maximum size of binary JSON is 128 MB
+        size = qMin(size, 128U * 1024 * 1024);
+        // and it doesn't include the size of the header (8 bytes)
+        size += 8;
+        // finally, it can't be bigger than the file or section size
+        size = qMin(sectionSize, qsizetype(size));
+
+        QByteArray json(raw, size);
+        return QJsonDocument::fromBinaryData(json);
+    }
+#endif
+
+    return jsonFromCborMetaData(raw, sectionSize, errMsg);
 }
 
 class QFactoryLoaderPrivate : public QObjectPrivate
diff --git a/src/corelib/plugin/qfactoryloader_p.h b/src/corelib/plugin/qfactoryloader_p.h
index fe722999ae..7815ea0b5d 100644
--- a/src/corelib/plugin/qfactoryloader_p.h
+++ b/src/corelib/plugin/qfactoryloader_p.h
@@ -56,6 +56,7 @@
 
 #include "QtCore/qobject.h"
 #include "QtCore/qstringlist.h"
+#include "QtCore/qcborvalue.h"
 #include "QtCore/qjsonobject.h"
 #include "QtCore/qjsondocument.h"
 #include "QtCore/qmap.h"
@@ -66,7 +67,7 @@
 
 QT_BEGIN_NAMESPACE
 
-QJsonDocument qJsonFromRawLibraryMetaData(const char *raw, qsizetype size);
+QJsonDocument qJsonFromRawLibraryMetaData(const char *raw, qsizetype size, QString *errMsg);
 
 class QFactoryLoaderPrivate;
 class Q_CORE_EXPORT QFactoryLoader : public QObject
diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index 869ef6181f..aa63ed1a6b 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -268,7 +268,7 @@ static bool findPatternUnloaded(const QString &library, QLibraryPrivate *lib)
     */
     bool hasMetaData = false;
     qsizetype pos = 0;
-    char pattern[] = "qTMETADATA  ";
+    char pattern[] = "qTMETADATA ";
     pattern[0] = 'Q'; // Ensure the pattern "QTMETADATA" is not found in this library should QPluginLoader ever encounter it.
     const ulong plen = qstrlen(pattern);
 #if defined (Q_OF_ELF) && defined(Q_CC_GNU)
@@ -314,10 +314,14 @@ static bool findPatternUnloaded(const QString &library, QLibraryPrivate *lib)
 
     bool ret = false;
 
-    if (pos >= 0) {
-        if (hasMetaData) {
-            const char *data = filedata + pos;
-            QJsonDocument doc = qJsonFromRawLibraryMetaData(data, qsizetype(fdlen));
+    if (pos >= 0 && hasMetaData) {
+        const char *data = filedata + pos;
+        QString errMsg;
+        QJsonDocument doc = qJsonFromRawLibraryMetaData(data, fdlen, &errMsg);
+        if (doc.isNull()) {
+            qWarning("Found invalid metadata in lib %s: %s",
+                     qPrintable(library), qPrintable(errMsg));
+        } else {
             lib->metaData = doc.object();
             if (qt_debug_component())
                 qWarning("Found metadata in lib %s, metadata=\n%s\n",
@@ -679,20 +683,26 @@ bool QLibrary::isLibrary(const QString &fileName)
 #endif
 }
 
-typedef const char * (*QtPluginQueryVerificationDataFunction)();
-
-static bool qt_get_metadata(QtPluginQueryVerificationDataFunction pfn, QLibraryPrivate *priv)
+static bool qt_get_metadata(QLibraryPrivate *priv, QString *errMsg)
 {
-    const char *szData = 0;
-    if (!pfn)
-        return false;
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    auto getMetaData = [](QFunctionPointer fptr) {
+        auto f = reinterpret_cast<const char * (*)()>(fptr);
+        return qMakePair<const char *, size_t>(f(), INT_MAX);
+    };
+#else
+    auto getMetaData = [](QFunctionPointer fptr) {
+        auto f = reinterpret_cast<QPair<const char *, size_t> (*)()>(fptr);
+        return f();
+    };
+#endif
 
-    szData = pfn();
-    if (!szData)
+    QFunctionPointer pfn = priv->resolve("qt_plugin_query_metadata");
+    if (!pfn)
         return false;
 
-    // the data is already loaded, so the size doesn't matter
-    QJsonDocument doc = qJsonFromRawLibraryMetaData(szData, INT_MAX);
+    auto metaData = getMetaData(pfn);
+    QJsonDocument doc = qJsonFromRawLibraryMetaData(metaData.first, metaData.second, errMsg);
     if (doc.isNull())
         return false;
     priv->metaData = doc.object();
@@ -735,9 +745,7 @@ void QLibraryPrivate::updatePluginState()
     } else {
         // library is already loaded (probably via QLibrary)
         // simply get the target function and call it.
-        QtPluginQueryVerificationDataFunction getMetaData = NULL;
-        getMetaData = (QtPluginQueryVerificationDataFunction) resolve("qt_plugin_query_metadata");
-        success = qt_get_metadata(getMetaData, this);
+        success = qt_get_metadata(this, &errorString);
     }
 
     if (!success) {
diff --git a/src/corelib/plugin/qlibrary_win.cpp b/src/corelib/plugin/qlibrary_win.cpp
index 9368e53b3f..05a93d467e 100644
--- a/src/corelib/plugin/qlibrary_win.cpp
+++ b/src/corelib/plugin/qlibrary_win.cpp
@@ -97,10 +97,10 @@ bool QLibraryPrivate::load_sys()
 
     for (const QString &attempt : qAsConst(attempts)) {
 #ifndef Q_OS_WINRT
-        pHnd = LoadLibrary((wchar_t*)QDir::toNativeSeparators(attempt).utf16());
+        pHnd = LoadLibrary(reinterpret_cast<const wchar_t*>(QDir::toNativeSeparators(attempt).utf16()));
 #else // Q_OS_WINRT
         QString path = QDir::toNativeSeparators(QDir::current().relativeFilePath(attempt));
-        pHnd = LoadPackagedLibrary((LPCWSTR)path.utf16(), 0);
+        pHnd = LoadPackagedLibrary(reinterpret_cast<LPCWSTR>(path.utf16()), 0);
         if (pHnd)
             qualifiedFileName = attempt;
 #endif // !Q_OS_WINRT
diff --git a/src/corelib/plugin/qplugin.h b/src/corelib/plugin/qplugin.h
index c8200afeeb..676b5047d6 100644
--- a/src/corelib/plugin/qplugin.h
+++ b/src/corelib/plugin/qplugin.h
@@ -56,6 +56,21 @@ QT_BEGIN_NAMESPACE
 #  endif
 #endif
 
+inline constexpr unsigned char qPluginArchRequirements()
+{
+    return 0
+#ifndef QT_NO_DEBUG
+            | 1
+#endif
+#ifdef __AVX2__
+            | 2
+#  ifdef __AVX512F__
+            | 4
+#  endif
+#endif
+    ;
+}
+
 typedef QObject *(*QtPluginInstanceFunction)();
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 typedef const char *(*QtPluginMetaDataFunction)();
diff --git a/src/corelib/plugin/qplugin_p.h b/src/corelib/plugin/qplugin_p.h
new file mode 100644
index 0000000000..717129268b
--- /dev/null
+++ b/src/corelib/plugin/qplugin_p.h
@@ -0,0 +1,75 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QPLUGIN_P_H
+#define QPLUGIN_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of the QLibrary class.  This header file may change from
+// version to version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qglobal_p.h>
+
+QT_BEGIN_NAMESPACE
+
+enum class QtPluginMetaDataKeys {
+    QtVersion,
+    Requirements,
+    IID,
+    ClassName,
+    MetaData
+};
+
+// F(IntKey, StringKey, Description)
+// Keep this list sorted in the order moc should output.
+#define QT_PLUGIN_FOREACH_METADATA(F) \
+    F(QtPluginMetaDataKeys::IID, "IID", "Plugin's Interface ID")                \
+    F(QtPluginMetaDataKeys::ClassName, "className", "Plugin class name")        \
+    F(QtPluginMetaDataKeys::MetaData, "MetaData", "Other meta data")
+
+QT_END_NAMESPACE
+
+#endif // QPLUGIN_P_H
diff --git a/src/corelib/plugin/qpluginloader.cpp b/src/corelib/plugin/qpluginloader.cpp
index 83cbcd2b44..0f94bb6adf 100644
--- a/src/corelib/plugin/qpluginloader.cpp
+++ b/src/corelib/plugin/qpluginloader.cpp
@@ -475,10 +475,19 @@ QVector<QStaticPlugin> QPluginLoader::staticPlugins()
 */
 QJsonObject QStaticPlugin::metaData() const
 {
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     // the data is already loaded, so this doesn't matter
     qsizetype rawMetaDataSize = INT_MAX;
+    const char *ptr = rawMetaData();
+#else
+    auto ptr = static_cast<const char *>(rawMetaData);
+#endif
 
-    return qJsonFromRawLibraryMetaData(rawMetaData(), rawMetaDataSize).object();
+    QString errMsg;
+    QJsonDocument doc = qJsonFromRawLibraryMetaData(ptr, rawMetaDataSize, &errMsg);
+    Q_ASSERT(doc.isObject());
+    Q_ASSERT(errMsg.isEmpty());
+    return doc.object();
 }
 
 QT_END_NAMESPACE
diff --git a/src/corelib/plugin/qsystemlibrary.cpp b/src/corelib/plugin/qsystemlibrary.cpp
index 7c80fbbd42..1f8cef790c 100644
--- a/src/corelib/plugin/qsystemlibrary.cpp
+++ b/src/corelib/plugin/qsystemlibrary.cpp
@@ -121,7 +121,7 @@ HINSTANCE QSystemLibrary::load(const wchar_t *libraryName, bool onlySystemDirect
             fullPathAttempt.append(QLatin1Char('\\'));
         }
         fullPathAttempt.append(fileName);
-        HINSTANCE inst = ::LoadLibrary((const wchar_t *)fullPathAttempt.utf16());
+        HINSTANCE inst = ::LoadLibrary(reinterpret_cast<const wchar_t *>(fullPathAttempt.utf16()));
         if (inst != 0)
             return inst;
     }
diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index 57ae671897..5714f5236c 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -318,7 +318,8 @@ void qt_set_thread_name(HANDLE threadId, LPCSTR threadName)
 
     __try
     {
-        RaiseException(0x406D1388, 0, sizeof(info)/sizeof(DWORD), (const ULONG_PTR*)&info);
+        RaiseException(0x406D1388, 0, sizeof(info)/sizeof(DWORD),
+                       reinterpret_cast<const ULONG_PTR*>(&info));
     }
     __except (EXCEPTION_CONTINUE_EXECUTION)
     {
@@ -365,7 +366,7 @@ unsigned int __stdcall QT_ENSURE_STACK_ALIGNED_FOR_SSE QThreadPrivate::start(voi
 #if !defined(QT_NO_DEBUG) && defined(Q_CC_MSVC) && !defined(Q_OS_WINRT)
     // sets the name of the current thread.
     QByteArray objectName = thr->objectName().toLocal8Bit();
-    qt_set_thread_name((HANDLE)-1,
+    qt_set_thread_name(HANDLE(-1),
                        objectName.isEmpty() ?
                        thr->metaObject()->className() : objectName.constData());
 #endif
@@ -508,8 +509,9 @@ void QThread::start(Priority priority)
                                             this, CREATE_SUSPENDED, &(d->id));
 #else
     // MSVC -MD or -MDd or MinGW build
-    d->handle = (Qt::HANDLE) CreateThread(NULL, d->stackSize, (LPTHREAD_START_ROUTINE)QThreadPrivate::start,
-                                            this, CREATE_SUSPENDED, reinterpret_cast<LPDWORD>(&d->id));
+    d->handle = CreateThread(nullptr, d->stackSize,
+                             reinterpret_cast<LPTHREAD_START_ROUTINE>(QThreadPrivate::start),
+                             this, CREATE_SUSPENDED, reinterpret_cast<LPDWORD>(&d->id));
 #endif // Q_OS_WINRT
 
     if (!d->handle) {
diff --git a/src/corelib/tools/qlocale_win.cpp b/src/corelib/tools/qlocale_win.cpp
index 30aefb71c1..e1a61fa9d7 100644
--- a/src/corelib/tools/qlocale_win.cpp
+++ b/src/corelib/tools/qlocale_win.cpp
@@ -274,7 +274,7 @@ QSystemLocalePrivate::SubstitutionType QSystemLocalePrivate::substitution()
 QString &QSystemLocalePrivate::substituteDigits(QString &string)
 {
     ushort zero = zeroDigit().unicode();
-    ushort *qch = (ushort *)string.data();
+    ushort *qch = reinterpret_cast<ushort *>(string.data());
     for (ushort *end = qch + string.size(); qch != end; ++qch) {
         if (*qch >= '0' && *qch <= '9')
             *qch = zero + (*qch - '0');
diff --git a/src/corelib/tools/qsimd.cpp b/src/corelib/tools/qsimd.cpp
index 85efd3cded..07a8b022bc 100644
--- a/src/corelib/tools/qsimd.cpp
+++ b/src/corelib/tools/qsimd.cpp
@@ -190,7 +190,9 @@ static inline quint64 detectProcessorFeatures()
 
 static int maxBasicCpuidSupported()
 {
-#if defined(Q_CC_GNU)
+#if defined(Q_CC_EMSCRIPTEN)
+    return 6; // All features supported by Emscripten
+#elif defined(Q_CC_GNU)
     qregisterint tmp1;
 
 # if Q_PROCESSOR_X86 < 5
@@ -235,7 +237,7 @@ static int maxBasicCpuidSupported()
 
 static void cpuidFeatures01(uint &ecx, uint &edx)
 {
-#if defined(Q_CC_GNU)
+#if defined(Q_CC_GNU) && !defined(Q_CC_EMSCRIPTEN)
     qregisterint tmp1;
     asm ("xchg " PICreg", %2\n"
          "cpuid\n"
@@ -252,6 +254,9 @@ static void cpuidFeatures01(uint &ecx, uint &edx)
     __CPUID(1, info);
     ecx = info[2];
     edx = info[3];
+#else
+    Q_UNUSED(ecx);
+    Q_UNUSED(edx);
 #endif
 }
 
@@ -261,7 +266,7 @@ inline void __cpuidex(int info[4], int, __int64) { memset(info, 0, 4*sizeof(int)
 
 static void cpuidFeatures07_00(uint &ebx, uint &ecx, uint &edx)
 {
-#if defined(Q_CC_GNU)
+#if defined(Q_CC_GNU) && !defined(Q_CC_EMSCRIPTEN)
     qregisteruint rbx; // in case it's 64-bit
     qregisteruint rcx = 0;
     qregisteruint rdx = 0;
@@ -294,7 +299,7 @@ inline quint64 _xgetbv(__int64) { return 0; }
 #endif
 static void xgetbv(uint in, uint &eax, uint &edx)
 {
-#if defined(Q_CC_GNU) || defined(Q_CC_GHS)
+#if (defined(Q_CC_GNU) && !defined(Q_CC_EMSCRIPTEN)) || defined(Q_CC_GHS)
     asm (".byte 0x0F, 0x01, 0xD0" // xgetbv instruction
         : "=a" (eax), "=d" (edx)
         : "c" (in));
@@ -302,6 +307,10 @@ static void xgetbv(uint in, uint &eax, uint &edx)
     quint64 result = _xgetbv(in);
     eax = result;
     edx = result >> 32;
+#else
+    Q_UNUSED(in);
+    Q_UNUSED(eax);
+    Q_UNUSED(edx);
 #endif
 }
 
diff --git a/src/corelib/tools/qtimezoneprivate_win.cpp b/src/corelib/tools/qtimezoneprivate_win.cpp
index ec91b7e8a8..ca7ea24fc5 100644
--- a/src/corelib/tools/qtimezoneprivate_win.cpp
+++ b/src/corelib/tools/qtimezoneprivate_win.cpp
@@ -140,15 +140,15 @@ bool equalTzi(const TIME_ZONE_INFORMATION &tzi1, const TIME_ZONE_INFORMATION &tz
 #ifdef QT_USE_REGISTRY_TIMEZONE
 bool openRegistryKey(const QString &keyPath, HKEY *key)
 {
-    return (RegOpenKeyEx(HKEY_LOCAL_MACHINE, (const wchar_t*)keyPath.utf16(), 0, KEY_READ, key)
-            == ERROR_SUCCESS);
+    return RegOpenKeyEx(HKEY_LOCAL_MACHINE, reinterpret_cast<const wchar_t*>(keyPath.utf16()),
+                        0, KEY_READ, key) == ERROR_SUCCESS;
 }
 
 QString readRegistryString(const HKEY &key, const wchar_t *value)
 {
     wchar_t buffer[MAX_PATH] = {0};
     DWORD size = sizeof(wchar_t) * MAX_PATH;
-    RegQueryValueEx(key, (LPCWSTR)value, NULL, NULL, (LPBYTE)buffer, &size);
+    RegQueryValueEx(key, value, nullptr, nullptr, reinterpret_cast<LPBYTE>(buffer), &size);
     return QString::fromWCharArray(buffer);
 }
 
@@ -156,7 +156,7 @@ int readRegistryValue(const HKEY &key, const wchar_t *value)
 {
     DWORD buffer;
     DWORD size = sizeof(buffer);
-    RegQueryValueEx(key, (LPCWSTR)value, NULL, NULL, (LPBYTE)&buffer, &size);
+    RegQueryValueEx(key, value, nullptr, nullptr, reinterpret_cast<LPBYTE>(&buffer), &size);
     return buffer;
 }
 
@@ -167,7 +167,7 @@ QWinTimeZonePrivate::QWinTransitionRule readRegistryRule(const HKEY &key,
     QWinTimeZonePrivate::QWinTransitionRule rule;
     REG_TZI_FORMAT tzi;
     DWORD tziSize = sizeof(tzi);
-    if (RegQueryValueEx(key, (LPCWSTR)value, NULL, NULL, (BYTE *)&tzi, &tziSize)
+    if (RegQueryValueEx(key, value, nullptr, nullptr, reinterpret_cast<BYTE *>(&tzi), &tziSize)
         == ERROR_SUCCESS) {
         rule.startYear = 0;
         rule.standardTimeBias = tzi.Bias + tzi.StandardBias;
@@ -192,12 +192,12 @@ TIME_ZONE_INFORMATION getRegistryTzi(const QByteArray &windowsId, bool *ok)
     if (openRegistryKey(tziKeyPath, &key)) {
 
         DWORD size = sizeof(tzi.DaylightName);
-        RegQueryValueEx(key, L"Dlt", NULL, NULL, (LPBYTE)tzi.DaylightName, &size);
+        RegQueryValueEx(key, L"Dlt", nullptr, nullptr, reinterpret_cast<LPBYTE>(tzi.DaylightName), &size);
 
         size = sizeof(tzi.StandardName);
-        RegQueryValueEx(key, L"Std", NULL, NULL, (LPBYTE)tzi.StandardName, &size);
+        RegQueryValueEx(key, L"Std", nullptr, nullptr, reinterpret_cast<LPBYTE>(tzi.StandardName), &size);
 
-        if (RegQueryValueEx(key, L"TZI", NULL, NULL, (BYTE *) &regTzi, &regTziSize)
+        if (RegQueryValueEx(key, L"TZI", nullptr, nullptr, reinterpret_cast<BYTE *>(&regTzi), &regTziSize)
             == ERROR_SUCCESS) {
             tzi.Bias = regTzi.Bias;
             tzi.StandardBias = regTzi.StandardBias;
@@ -590,7 +590,7 @@ void QWinTimeZonePrivate::init(const QByteArray &ianaId)
                 for (int year = startYear; year <= endYear; ++year) {
                     bool ruleOk;
                     QWinTransitionRule rule = readRegistryRule(dynamicKey,
-                                                               (LPCWSTR)QString::number(year).utf16(),
+                                                               reinterpret_cast<LPCWSTR>(QString::number(year).utf16()),
                                                                &ruleOk);
                     if (ruleOk
                         // Don't repeat a recurrent rule:
diff --git a/src/corelib/tools/qunicodetables_p.h b/src/corelib/tools/qunicodetables_p.h
index f3fb6ec1b0..3f2e91a9b2 100644
--- a/src/corelib/tools/qunicodetables_p.h
+++ b/src/corelib/tools/qunicodetables_p.h
@@ -72,6 +72,9 @@ struct Properties {
     signed short mirrorDiff    : 16;
     ushort lowerCaseSpecial    : 1;
     signed short lowerCaseDiff : 15;
+#ifdef Q_OS_WASM
+    unsigned char              : 0; //wasm 64 packing trick
+#endif
     ushort upperCaseSpecial    : 1;
     signed short upperCaseDiff : 15;
     ushort titleCaseSpecial    : 1;
@@ -80,6 +83,9 @@ struct Properties {
     signed short caseFoldDiff  : 15;
     ushort unicodeVersion      : 8; /* 5 used */
     ushort nfQuickCheck        : 8;
+#ifdef Q_OS_WASM
+    unsigned char              : 0; //wasm 64 packing trick
+#endif
     ushort graphemeBreakClass  : 5; /* 5 used */
     ushort wordBreakClass      : 5; /* 5 used */
     ushort sentenceBreakClass  : 8; /* 4 used */
diff --git a/src/corelib/tools/tools.pri b/src/corelib/tools/tools.pri
index 6b180602c2..995bab694e 100644
--- a/src/corelib/tools/tools.pri
+++ b/src/corelib/tools/tools.pri
@@ -221,7 +221,7 @@ qtConfig(system-doubleconversion) {
 }
 
 # Note: libm should be present by default becaue this is C++
-unix:!macx-icc:!vxworks:!haiku:!integrity: LIBS_PRIVATE += -lm
+unix:!macx-icc:!vxworks:!haiku:!integrity:!wasm: LIBS_PRIVATE += -lm
 
 TR_EXCLUDE += ../3rdparty/*