"Priya Sinha" <pucsd.priya@xxxxxxxxx> writes: > in coretypes.h the def of rtx is there as > > #define rtx struct _dont_use_rtx_here; > > but i don't know where this struct _dont_use_rtx_here is defined. It is not defined anywhere. You have to look at the #ifdef sequence. The correct definition of rtx is found earlier in coretypes.h. Ian