2.8.4 does_not_return

#pragma does_not_return (funcname [, funcname])

This pragma is an assertion to the compiler that the calls to the specified routines will not return. This allows the compiler to perform optimizations consistent with that assumption. For example, register life-times will terminate at the call sites which in turn allows more optimizations.

If the specified function does return, then the behavior of the program is undefined. This pragma is permitted only after the specified functions are declared with a prototype or empty parameter list as the following example shows:

extern void exit(int);
#pragma does_not_return(exit)

extern void __assert(int);
#pragma does_not_return(__assert)