We're moving a large ARM based project from 2.95 to the 4.2.1 compiler and it generates of type-punning warnings. The 
warnings say

"warning: dereferencing type-punned pointer will break strict aliasing rules"

and always come on PxConfigReadInt() calls like this:

PxConfigReadInt( section, "pwrunits", DPWRW, (int *)&buf->pwrunits);

It seems not to like the (int *) cast on the unary & operator when the pointer references an enum type. Changing the 
code like this eliminates the warning

int tp;
tp = (int) buf->pwrunits;
PxConfigReadInt( section, "pwrunits", DPWRW, &tp);
buf->pwrUnits = tp;

but that seems like stupid-work.

Strict aliasing can be turned off but without fully understanding the issue that seems like a questionable move.

Where is the type-pun in this call? I don't see it, but then I'm no expert at C arcana.