Teach qmake MSVC's compiler options /std:c++[14|17|latest]

This fixes the "could not parse compiler option" warning when
generating VS project files.

Fixes: QTBUG-75275
Change-Id: Idd98ae5fdb8ebf5a4e311cbb6cd3ed1daba74ca4
Reviewed-by: Kai Koehne <kai.koehne@qt.io>

3 files changed, 11 insertions, 0 deletions

diff --git a/qmake/generators/win32/msbuild_objectmodel.cpp b/qmake/generators/win32/msbuild_objectmodel.cpp
index ad2976aa01..87cd560552 100644
--- a/qmake/generators/win32/msbuild_objectmodel.cpp
+++ b/qmake/generators/win32/msbuild_objectmodel.cpp
@@ -143,6 +143,7 @@ const char _InterfaceIdentifierFileName[]       = "InterfaceIdentifierFileName";
 const char _IntermediateDirectory[]             = "IntermediateDirectory";
 const char _KeyContainer[]                      = "KeyContainer";
 const char _KeyFile[]                           = "KeyFile";
+const char _LanguageStandard[]                  = "LanguageStandard";
 const char _LargeAddressAware[]                 = "LargeAddressAware";
 const char _LinkDLL[]                           = "LinkDLL";
 const char _LinkErrorReporting[]                = "LinkErrorReporting";
@@ -1492,6 +1493,7 @@ void VCXProjectWriter::write(XmlOutput &xml, const VCCLCompilerTool &tool)
             << attrTagT(_IntrinsicFunctions, tool.EnableIntrinsicFunctions)
             << attrTagT(_MinimalRebuild, tool.MinimalRebuild)
             << attrTagT(_MultiProcessorCompilation, tool.MultiProcessorCompilation)
+            << attrTagS(_LanguageStandard, tool.LanguageStandard)
             << attrTagS(_ObjectFileName, tool.ObjectFile)
             << attrTagT(_OmitDefaultLibName, tool.OmitDefaultLibName)
             << attrTagT(_OmitFramePointers, tool.OmitFramePointers)
diff --git a/qmake/generators/win32/msvc_objectmodel.cpp b/qmake/generators/win32/msvc_objectmodel.cpp
index 7335211f30..f08554d0f5 100644
--- a/qmake/generators/win32/msvc_objectmodel.cpp
+++ b/qmake/generators/win32/msvc_objectmodel.cpp
@@ -1146,6 +1146,14 @@ bool VCCLCompilerTool::parseOption(const char* option)
             ShowIncludes = _True;
             break;
         }
+        if (strlen(option) > 8 && second == 't' && third == 'd') {
+            const QString version = option + 8;
+            static const QStringList knownVersions = { "14", "17", "latest" };
+            if (knownVersions.contains(version)) {
+                LanguageStandard = "stdcpp" + version;
+                break;
+            }
+        }
         found = false; break;
     case 'u':
         if (!second)
diff --git a/qmake/generators/win32/msvc_objectmodel.h b/qmake/generators/win32/msvc_objectmodel.h
index 41a6ffafa7..f6d1fc8023 100644
--- a/qmake/generators/win32/msvc_objectmodel.h
+++ b/qmake/generators/win32/msvc_objectmodel.h
@@ -526,6 +526,7 @@ public:
     triState                ImproveFloatingPointConsistency;
     inlineExpansionOption   InlineFunctionExpansion;
     triState                KeepComments;
+    QString                 LanguageStandard;
     triState                MinimalRebuild;
     QString                 ObjectFile;
     triState                OmitDefaultLibName;