I am using Visual Studio mainly for programming in C/C++ and at the moment I am messing around with devkitpro (has compilers and more for many nintendo systems) to programm games for the GBA. Because the GBA-compiler needs its own folder structure I don't want to create a whole Visual Studio project but rather just open and edit the single files within VS.
However if I open a .c/.h/.cpp file directly the red underlines for errors within the code don't show up and the error-window doesn't show errors either.
I looked into tools → options → Text Editor → C/C++ → advanced if the corresponding settings are correct and they are. Nothing is deactivated everything is as usual.
Any ideas how to toggle on errors for single files?