Jason Dictos <jdictos@xxxxxxxxxxxxx> writes: > 1. Does the .gch file have to exist in the same directory as the .h in > order for gcc to use it? No, but if it is in a different directory it has to come earlier in the header search path. > 2. How can we check to see if gcc is using a .gch file, and conversely > how can we check to see if gcc is not using a .gch file? The -H option will list all the included files. Ian