From 38597dd08083f1f5cbf947cd3b0290065f2872c6 Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Sat, 10 Mar 2018 11:17:47 -0800
Subject: [PATCH] Atomic: silence MSVC warning in the generic fetchAndSub

MSVC atomics still use the generic version, instead of qatomic_cxx11.h.
The implementation of fetchAndSub is implemented on top of fetchAndAdd,
but produced a warning with unsigned types.

Change-Id: I72f5230ad59948f784eafffd151aa53435b75298
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/corelib/thread/qgenericatomic.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/corelib/thread/qgenericatomic.h b/src/corelib/thread/qgenericatomic.h
index 5c4c02a2ec..89c4fe9a11 100644
--- a/src/corelib/thread/qgenericatomic.h
+++ b/src/corelib/thread/qgenericatomic.h
@@ -253,12 +253,15 @@ template <typename BaseClass> struct QGenericAtomicOps
         return BaseClass::fetchAndAddRelaxed(_q_value, valueToAdd);
     }
 
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_MSVC(4146)   // unary minus operator applied to unsigned type, result still unsigned
     template <typename T> static Q_ALWAYS_INLINE
     T fetchAndSubRelaxed(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW
     {
         // implement fetchAndSub on top of fetchAndAdd
         return fetchAndAddRelaxed(_q_value, -operand);
     }
+QT_WARNING_POP
 
     template <typename T> static Q_ALWAYS_INLINE
     T fetchAndSubAcquire(T &_q_value, typename QAtomicAdditiveType<T>::AdditiveT operand) Q_DECL_NOTHROW