d6a10893cd
The way that Qt checks if C++20 is supported by the platform does not work properly on VxWorks. Their toolchain accepts the C++20 switch, because they use clang with a wrapper around it, that (for the time being) does not reject it. The compiler itself claims that it does support C++20. The problem is that the standard library available on VxWorks only supports C++17. This leads to Qt falsely believing that C++20 is supported. This is being discussed as a defect in support case 00152044. Prevent weird compilation errors by failing early if the user passes -feature-c++20 to the configure call. Task-number: QTBUG-115777 Pick-to: 6.7 Change-Id: Ica6686428b01a0638117f853586313be63e5fe99 Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io> (cherry picked from commit a578a09a418c689c9c9a43152961288ad075471b) Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>