From 4cd527f496afda258a9fa2341181956b0946c119 Mon Sep 17 00:00:00 2001
From: Nikolai Kosjar <nikolai.kosjar@qt.io>
Date: Mon, 8 Oct 2018 14:10:20 +0200
Subject: [PATCH] ProjectExplorer/MSVC: Ignore warning options when looking for
 predefined macros

...since they should not have any effect on the macros. This potentially
also reduces the cache.

Change-Id: If50cfa50ce0fb29dff291bf2c329532fc6284644
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>
---
 src/plugins/projectexplorer/abstractmsvctoolchain.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
index 3983734c753..49f59dac2db 100644
--- a/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
+++ b/src/plugins/projectexplorer/abstractmsvctoolchain.cpp
@@ -146,10 +146,15 @@ LanguageVersion static languageVersionForMsvc(const Core::Id &language, const Ma
     }
 }
 
-bool static hasFlagEffectOnMacros(const QString &arg)
+bool static hasFlagEffectOnMacros(const QString &flag)
 {
-    if (arg.startsWith("-I"))
-        return false;
+    if (flag.startsWith("-") || flag.startsWith("/")) {
+        const QString f = flag.mid(1);
+        if (f.startsWith("I"))
+            return false; // Skip include paths
+        if (f.startsWith("w", Qt::CaseInsensitive))
+            return false; // Skip warning options
+    }
     return true;
 }