quoted

quoted

What you probably mean is that the compiler has to assume any code
it cannot currently see can do anything (insofar as allowed by the
relevant standards etc.)

I think this was just terminology confusion here again. Isn't "any code
that it cannot currently see" the same as "another compilation unit",

It is not; try  gcc -combine  or the upcoming link-time optimisation
stuff, for example.

and wouldn't the "compilation unit" itself expand if we ask gcc to
compile more than one unit at once? Or is there some more specific
"definition" for "compilation unit" (in gcc lingo, possibly?)

"compilation unit" is a C standard term.  It typically boils down
to "single .c file".


Segher