Remove unneeded @available check for macOS <= 10.14 and iOS <= 13

All versions down to Qt 6.2 require macOS 10.14 or iOS 13.

Change-Id: I5048921ea5a149346a0fa84228227d9156004675
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
(cherry picked from commit 1e97a44e765a61305f3d8ffbca5d33c05008744c)
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/corelib/kernel/qcore_mac.mm

@@ -263,16 +263,9 @@ QMacAutoReleasePool::QMacAutoReleasePool()
 
 #ifdef QT_DEBUG
     void *poolFrame = nullptr;
-    if (__builtin_available(macOS 10.14, iOS 12.0, tvOS 12.0, watchOS 5.0, *)) {
     void *frame;
     if (backtrace_from_fp(__builtin_frame_address(0), &frame, 1))
         poolFrame = frame;
-    } else {
-        static const int maxFrames = 3;
-        void *callstack[maxFrames];
-        if (backtrace(callstack, maxFrames) == maxFrames)
-            poolFrame = callstack[maxFrames - 1];
-    }
 
     if (poolFrame) {
         Dl_info info;
@@ -343,12 +336,9 @@ QDebug operator<<(QDebug debug, const QCFString &string)
 #ifdef Q_OS_MACOS
 bool qt_mac_applicationIsInDarkMode()
 {
-    if (__builtin_available(macOS 10.14, *)) {
     auto appearance = [NSApp.effectiveAppearance bestMatchFromAppearancesWithNames:
             @[ NSAppearanceNameAqua, NSAppearanceNameDarkAqua ]];
     return [appearance isEqualToString:NSAppearanceNameDarkAqua];
-    }
-    return false;
 }
 
 bool qt_mac_runningUnderRosetta()

src/plugins/platforms/cocoa/qcocoatheme.mm

@@ -98,14 +98,9 @@ static QPalette *qt_mac_createSystemPalette()
     // System palette initialization:
     QBrush br = qt_mac_toQBrush([NSColor selectedControlColor]);
     palette->setBrush(QPalette::Active, QPalette::Highlight, br);
-    if (__builtin_available(macOS 10.14, *)) {
     const auto inactiveHighlight = qt_mac_toQBrush([NSColor unemphasizedSelectedContentBackgroundColor]);
     palette->setBrush(QPalette::Inactive, QPalette::Highlight, inactiveHighlight);
     palette->setBrush(QPalette::Disabled, QPalette::Highlight, inactiveHighlight);
-    } else {
-        palette->setBrush(QPalette::Inactive, QPalette::Highlight, br);
-        palette->setBrush(QPalette::Disabled, QPalette::Highlight, br);
-    }
 
     palette->setBrush(QPalette::Shadow, qt_mac_toQColor([NSColor shadowColor]));
 
@@ -190,17 +185,8 @@ static QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
         }
         if (mac_widget_colors[i].paletteRole == QPlatformTheme::MenuPalette
                 || mac_widget_colors[i].paletteRole == QPlatformTheme::MenuBarPalette) {
-            NSColor *selectedMenuItemColor = nil;
-            if (__builtin_available(macOS 10.14, *)) {
             // Cheap approximation for NSVisualEffectView (see deprecation note for selectedMenuItemTextColor)
-                selectedMenuItemColor = [[NSColor selectedContentBackgroundColor] highlightWithLevel:0.4];
+            auto selectedMenuItemColor = [[NSColor selectedContentBackgroundColor] highlightWithLevel:0.4];
-            } else {
-                // selectedMenuItemColor would presumably be the correct color to use as the background
-                // for selected menu items. But that color is always blue, and doesn't follow the
-                // appearance color in system preferences. So we therefore deliberately choose to use
-                // keyboardFocusIndicatorColor instead, which appears to have the same color value.
-                selectedMenuItemColor = [NSColor keyboardFocusIndicatorColor];
-            }
             pal.setBrush(QPalette::Highlight, qt_mac_toQColor(selectedMenuItemColor));
             qc = qt_mac_toQColor([NSColor labelColor]);
             pal.setBrush(QPalette::ButtonText, qc);
@@ -221,17 +207,10 @@ static QHash<QPlatformTheme::Palette, QPalette*> qt_mac_createRolePalettes()
         } else if (mac_widget_colors[i].paletteRole == QPlatformTheme::ItemViewPalette) {
             NSArray<NSColor *> *baseColors = nil;
             NSColor *activeHighlightColor = nil;
-            if (__builtin_available(macOS 10.14, *)) {
             baseColors = [NSColor alternatingContentBackgroundColors];
             activeHighlightColor = [NSColor selectedContentBackgroundColor];
             pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
                          qt_mac_toQBrush([NSColor unemphasizedSelectedTextColor]));
-            } else {
-                baseColors = [NSColor controlAlternatingRowBackgroundColors];
-                activeHighlightColor = [NSColor alternateSelectedControlColor];
-                pal.setBrush(QPalette::Inactive, QPalette::HighlightedText,
-                             pal.brush(QPalette::Active, QPalette::Text));
-            }
             pal.setBrush(QPalette::Base, qt_mac_toQBrush(baseColors[0]));
             pal.setBrush(QPalette::AlternateBase, qt_mac_toQBrush(baseColors[1]));
             pal.setBrush(QPalette::Active, QPalette::Highlight,
@@ -267,9 +246,7 @@ QCocoaTheme::QCocoaTheme()
 {
     if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::MacOSMojave) {
         m_appearanceObserver = QMacKeyValueObserver(NSApp, @"effectiveAppearance", [this] {
-            if (__builtin_available(macOS 10.14, *))
             NSAppearance.currentAppearance = NSApp.effectiveAppearance;
-
             handleSystemThemeChange();
         });
     }

src/plugins/platforms/ios/qiosdocumentpickercontroller.mm

@@ -77,7 +77,6 @@
         if (m_fileDialog->options()->fileMode() == QFileDialogOptions::ExistingFiles)
             self.allowsMultipleSelection = YES;
 
-        if (@available(ios 13.0, *))
         self.directoryURL = m_fileDialog->options()->initialDirectory().toNSURL();
     }
     return self;

src/plugins/platforms/ios/qiosscreen.mm

@@ -213,14 +213,12 @@ static QIOSScreen* qtPlatformScreenFor(UIScreen *uiScreen)
 {
     [super traitCollectionDidChange:previousTraitCollection];
 
-    if (@available(iOS 12, *)) {
     if (self.screen == UIScreen.mainScreen) {
         if (previousTraitCollection.userInterfaceStyle != self.traitCollection.userInterfaceStyle) {
             QIOSTheme::initializeSystemPalette();
             QWindowSystemInterface::handleThemeChange<QWindowSystemInterface::SynchronousDelivery>(nullptr);
         }
     }
-    }
 }
 
 @end

src/plugins/platforms/ios/qiostheme.mm

@@ -79,7 +79,6 @@ void QIOSTheme::initializeSystemPalette()
     Q_DECL_IMPORT QPalette qt_fusionPalette(void);
     s_systemPalette = qt_fusionPalette();
 
-    if (@available(ios 13.0, *)) {
     s_systemPalette.setBrush(QPalette::Window, qt_mac_toQBrush(UIColor.systemGroupedBackgroundColor.CGColor));
     s_systemPalette.setBrush(QPalette::Active, QPalette::WindowText, qt_mac_toQBrush(UIColor.labelColor.CGColor));
 
@@ -97,10 +96,6 @@ void QIOSTheme::initializeSystemPalette()
 
     s_systemPalette.setBrush(QPalette::Highlight, QColor(11, 70, 150, 60));
     s_systemPalette.setBrush(QPalette::HighlightedText, qt_mac_toQBrush(UIColor.labelColor.CGColor));
-    } else {
-        s_systemPalette.setBrush(QPalette::Highlight, QColor(204, 221, 237));
-        s_systemPalette.setBrush(QPalette::HighlightedText, Qt::black);
-    }
 }
 
 const QPalette *QIOSTheme::palette(QPlatformTheme::Palette type) const

src/plugins/platforms/ios/quiview.mm

@@ -747,15 +747,7 @@ Q_LOGGING_CATEGORY(lcQpaTablet, "qt.qpa.input.tablet")
 
 + (Class)layerClass
 {
-#ifdef TARGET_IPHONE_SIMULATOR
-    if (@available(ios 13.0, *))
-#endif
-
     return [CAMetalLayer class];
-
-#ifdef TARGET_IPHONE_SIMULATOR
-    return nil;
-#endif
 }
 
 @end

src/plugins/styles/mac/qmacstyle_mac.mm

@@ -1849,14 +1849,10 @@ NSView *QMacStylePrivate::cocoaControl(CocoaControl widget) const
         || widget.size == QStyleHelper::SizeDefault)
         return nil;
 
-    if (widget.type == Box) {
+    if (widget.type == Box && isDarkMode()) {
-        if (__builtin_available(macOS 10.14, *)) {
-            if (isDarkMode()) {
         // See render code in drawPrimitive(PE_FrameTabWidget)
         widget.type = Box_Dark;
     }
-        }
-    }
 
     NSView *bv = cocoaControls.value(widget, nil);
     if (!bv) {

src/plugins/tls/securetransport/qtls_st.cpp

@@ -354,7 +354,6 @@ void TlsCryptographSecureTransport::continueHandshake()
     // (and send it during handshake) and then receive what our peer has sent to us.
     // And here we can finally try to find a match (if any).
     const auto &configuration = q->sslConfiguration();
-    if (__builtin_available(macOS 10.13, iOS 11.0, tvOS 11.0, watchOS 4.0, *)) {
     const auto &requestedProtocols = configuration.allowedNextProtocols();
     if (const int requestedCount = requestedProtocols.size()) {
         QTlsBackend::setAlpnStatus(d, QSslConfiguration::NextProtocolNegotiationNone);
@@ -382,7 +381,6 @@ void TlsCryptographSecureTransport::continueHandshake()
             }
         }
     }
-    }
 
     if (!renegotiating)
         emit q->encrypted();
@@ -723,7 +721,6 @@ bool TlsCryptographSecureTransport::initSslContext()
         return false;
     }
 
-    if (__builtin_available(macOS 10.13, iOS 11.0, tvOS 11.0, watchOS 4.0, *)) {
     const auto protocolNames = configuration.allowedNextProtocols();
     QCFType<CFMutableArrayRef> cfNames(CFArrayCreateMutable(nullptr, 0, &kCFTypeArrayCallBacks));
     if (cfNames) {
@@ -749,7 +746,6 @@ bool TlsCryptographSecureTransport::initSslContext()
     } else {
         qCWarning(lcSecureTransport) << "failed to allocate ALPN names array";
     }
-    }
 
     if (mode == QSslSocket::SslClientMode) {
         // enable Server Name Indication (SNI)