> but you'd likely run into the problem at build time when it tries to create the preprocessed file with the same filename as the original Only if you use -sav

> but you'd likely run into the problem at build time when it tries to create the preprocessed file with the same filename as the original Only if you use -save-temps, which is rarely used (it's there mostly for when you want to debug the preprocessed code). Otherwise, in the common case where you are going from the .S to the .o, the intermediate .s is saved somewhere in /tmp (without -pipe) or exists only in memory (with -pipe).