From 1184b79381c4dd12a46ad1065becfa48203b1f4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tor=20Arne=20Vestb=C3=B8?= <tor.arne.vestbo@qt.io>
Date: Wed, 8 Jul 2020 13:52:36 +0200
Subject: [PATCH] macOS: Don't assume platform has objc_msgSendSuper_stret

It's not used on arm64, and the template magic is not enough to
avoid compilation failures due to references to the undefined
function.

Task-number: QTBUG-85279
Change-Id: Iac94f59a863c7be1860b51def0fc2de2d8812cf8
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
(cherry picked from commit b10f8ba3506c6c8c941826aee0225192aa4cd1af)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/plugins/platforms/cocoa/qcocoahelpers.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.h b/src/plugins/platforms/cocoa/qcocoahelpers.h
index 69aa7937b66..2aaff8c4ce9 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.h
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.h
@@ -254,14 +254,16 @@ template <typename T>
 struct objc_msgsend_requires_stret
 { static const bool value =
 #if defined(Q_PROCESSOR_X86)
+    #define PLATFORM_USES_SEND_SUPER_STRET 1
     // Any return value larger than two registers on i386/x86_64
     sizeof(T) > sizeof(void*) * 2;
 #elif defined(Q_PROCESSOR_ARM_32)
+    #define PLATFORM_USES_SEND_SUPER_STRET 1
     // Any return value larger than a single register on arm
-    sizeof(T) >  sizeof(void*);
+    sizeof(T) > sizeof(void*);
 #elif defined(Q_PROCESSOR_ARM_64)
-    // Stret not used on arm64
-    false;
+    #define PLATFORM_USES_SEND_SUPER_STRET 0
+    false; // Stret not used on arm64
 #endif
 };
 
@@ -281,6 +283,7 @@ ReturnType qt_msgSendSuper(id receiver, SEL selector, Args... args)
     return superFn(&sup, selector, args...);
 }
 
+#if PLATFORM_USES_SEND_SUPER_STRET
 template <typename ReturnType, typename... Args>
 ReturnType qt_msgSendSuper_stret(id receiver, SEL selector, Args... args)
 {
@@ -295,6 +298,7 @@ ReturnType qt_msgSendSuper_stret(id receiver, SEL selector, Args... args)
     superStretFn(&ret, &sup, selector, args...);
     return ret;
 }
+#endif
 
 template<typename... Args>
 class QSendSuperHelper {
@@ -335,11 +339,13 @@ private:
         return qt_msgSendSuper<ReturnType>(m_receiver, m_selector, std::get<Is>(args)...);
     }
 
+#if PLATFORM_USES_SEND_SUPER_STRET
     template <typename ReturnType, int... Is>
     if_requires_stret<ReturnType, true> msgSendSuper(std::tuple<Args...>& args, QtPrivate::IndexesList<Is...>)
     {
         return qt_msgSendSuper_stret<ReturnType>(m_receiver, m_selector, std::get<Is>(args)...);
     }
+#endif
 
     template <typename ReturnType>
     ReturnType msgSendSuper(std::tuple<Args...>& args)