In Visual Studio, there’s a choice of choosing different solution configurations: Debug Game, Debug Game Editor, Development, Development Editor, Shipping. I wonder what the difference between these choices. I guess making different configurations give you different macro settings?
Another question is, if it is not about macro settings, then where can I set the macros? Is setting them in the code the only way?
The different solutions define how the project is compiled and debugged. In general, Development Editor is what the game is built with during development by the editor. Debug Game Editor is good to use when you’ve got to debug a bug, though, I often still use Development Editor for that. and shipping is for actually building the game for shipping. (I actually haven’t used that one yet.)
For your other question, you don’t want to make any changes to any of your project or solution files. My best guess is to create a file specifically for your custom build symbols and include in your project header.