source: doc/theses/andrew_beach_MMath/code/fixup-empty-r.cfa@ a3cadfc

// Resume Across Empty Function
#include <clock.hfa>
#include <exception.hfa>
#include <fstream.hfa>
#include <stdlib.hfa>                                                                   // strto

exception fixup_exception {
        int & fixup;
};
vtable(fixup_exception) fixup_vt;

int nounwind_empty(unsigned int frames) {
        if (frames) {
                int rtn = nounwind_empty(frames - 1);
                if ( rtn == 42 ) printf( "42" );                                // make non-tail recursive
                return rtn;
        } else {
                int fixup = 17;
                throwResume (fixup_exception){&fixup_vt, fixup}; // change bad fixup
                return fixup;
        }
}

int main(int argc, char * argv[]) {
        unsigned int times = 1;
        unsigned int total_frames = 1;
        if (1 < argc) {
                times = strto(argv[1], 0p, 10);
        }
        if (2 < argc) {
                total_frames = strto(argv[2], 0p, 10);
        }

        Time start_time = timeHiRes();
        for (unsigned int count = 0 ; count < times ; ++count) {
                try {
                        nounwind_empty(total_frames);
                } catchResume (fixup_exception * ex) {
                        ex->fixup = total_frames + 42;
                }
        }
        Time end_time = timeHiRes();
        sout | "Run-Time (s): " | wd(0,1, (end_time - start_time)`ns / 1_000_000_000.);
}