5 files changed, 39 insertions, 4 deletions
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 01f534cc0f..12d76c0dca 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -4030,9 +4030,8 @@ bool qunsetenv(const char *varName)
 
     \list
     \li \c Q_PRIMITIVE_TYPE specifies that \a Type is a POD (plain old
-       data) type with no constructor or destructor, or else a type where
-       every bit pattern is a valid object and memcpy() creates a valid
-       independent copy of the object.
+       data) type with no constructor or destructor, and for which memcpy()ing
+       creates a valid independent copy of the object.
     \li \c Q_MOVABLE_TYPE specifies that \a Type has a constructor
        and/or a destructor but can be moved in memory using \c
        memcpy(). Note: despite the name, this has nothing to do with move
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index 5634d6e6c3..f2ada4ab30 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -709,10 +709,14 @@ QT_END_NAMESPACE
 
 #include "private/qcoreapplication_p.h"
 
+QT_WARNING_DISABLE_GCC("-Wattributes")
+QT_WARNING_DISABLE_CLANG("-Wattributes")
+QT_WARNING_DISABLE_INTEL(2621)
+
 extern const char qt_core_interpreter[] __attribute__((section(".interp")))
     = ELF_INTERPRETER;
 
-extern "C" void qt_core_boilerplate();
+extern "C" void qt_core_boilerplate() __attribute__((force_align_arg_pointer));
 void qt_core_boilerplate()
 {
     printf("This is the QtCore library version " QT_BUILD_STR "\n"
diff --git a/src/corelib/global/qoperatingsystemversion.cpp b/src/corelib/global/qoperatingsystemversion.cpp
index bc6adb54dc..a0ea801ba1 100644
--- a/src/corelib/global/qoperatingsystemversion.cpp
+++ b/src/corelib/global/qoperatingsystemversion.cpp
@@ -42,6 +42,10 @@
 #include "qoperatingsystemversion_p.h"
 #endif
 
+#if defined(Q_OS_DARWIN)
+#include <QtCore/private/qcore_mac_p.h>
+#endif
+
 #include <qversionnumber.h>
 #include <qdebug.h>
 
@@ -446,6 +450,27 @@ const QOperatingSystemVersion QOperatingSystemVersion::MacOSCatalina =
     QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 10, 15);
 
 /*!
+    \variable QOperatingSystemVersion::MacOSBigSur
+    \brief a version corresponding to macOS Big Sur
+
+    The actual version number depends on whether the application was built
+    using the Xcode 12 SDK. If it was, the version number corresponds
+    to macOS 11.0. If not it will correspond to macOS 10.16.
+
+    By comparing QOperatingSystemVersion::current() to this constant
+    you will always end up comparing to the right version number.
+    \since 6.0
+ */
+const QOperatingSystemVersion QOperatingSystemVersion::MacOSBigSur = [] {
+#if defined(Q_OS_DARWIN)
+    if (QMacVersion::buildSDK(QMacVersion::ApplicationBinary) >= QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 10, 16))
+        return QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 11, 0);
+    else
+#endif
+        return QOperatingSystemVersion(QOperatingSystemVersion::MacOS, 10, 16);
+}();
+
+/*!
     \variable QOperatingSystemVersion::AndroidJellyBean
     \brief a version corresponding to Android Jelly Bean (version 4.1, API level 16).
     \since 5.9
diff --git a/src/corelib/global/qoperatingsystemversion.h b/src/corelib/global/qoperatingsystemversion.h
index 89c60c4960..db4da1a9ae 100644
--- a/src/corelib/global/qoperatingsystemversion.h
+++ b/src/corelib/global/qoperatingsystemversion.h
@@ -72,6 +72,7 @@ public:
     static const QOperatingSystemVersion MacOSHighSierra;
     static const QOperatingSystemVersion MacOSMojave;
     static const QOperatingSystemVersion MacOSCatalina;
+    static const QOperatingSystemVersion MacOSBigSur;
 
     static const QOperatingSystemVersion AndroidJellyBean;
     static const QOperatingSystemVersion AndroidJellyBean_MR1;
diff --git a/src/corelib/global/qsystemdetection.h b/src/corelib/global/qsystemdetection.h
index 3e38e6790b..d87e181e5c 100644
--- a/src/corelib/global/qsystemdetection.h
+++ b/src/corelib/global/qsystemdetection.h
@@ -234,6 +234,9 @@
 #  if !defined(__MAC_10_15)
 #       define __MAC_10_15 101500
 #  endif
+#  if !defined(__MAC_10_16)
+#       define __MAC_10_16 101600
+#  endif
 #  if !defined(MAC_OS_X_VERSION_10_11)
 #       define MAC_OS_X_VERSION_10_11 __MAC_10_11
 #  endif
@@ -249,6 +252,9 @@
 #  if !defined(MAC_OS_X_VERSION_10_15)
 #       define MAC_OS_X_VERSION_10_15 __MAC_10_15
 #  endif
+#  if !defined(MAC_OS_X_VERSION_10_16)
+#       define MAC_OS_X_VERSION_10_16 __MAC_10_16
+#  endif
 #
 #  if !defined(__IPHONE_10_0)
 #       define __IPHONE_10_0 100000