It depends what seeing you have enabled, like sandboxing every application and so on. For normal applications thats no issue but GLBasic contains compiler, linker and other tools that can interfere into existing applications? (like inject icon), Bitdefender sees that and because GLBasic isn't well known tool (like many other development tools) it's flagged as virus. So just disable when installing, and should be ok.
About compilation it's similar, at default settings: Avast, AVG, GData and others that I used will temporary block newly compiled applications (pick up to sandbox, scan app, check if it doesn't do any harm to OS and then run it normally), and that can also affect normal c++ tools. Generally I just disable anti-virus software during developing. But you can check what heuristic level is set in your AV, also that directory exclude option should work - if it doesn't than AV has a bug.