sig_fpu_trigger1.cpp
Posted by Anonymous on Wed 2nd Feb 2022 10:15
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view followups (newest first): sig_fpu_trigger1.cpp by Anonymous and sig_fpu_trigger1.cpp.ltrace.log by Anonymous
modification of post by Anonymous (view diff)

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <setjmp.h>
#include <signal.h>
#include <math.h>
#include <fenv.h>

#include <stdexcept>
#include <iostream>


static sigjmp_buf jmp_env;
static volatile siginfo_t saved_siginfo;

static void sigfpe_handler(int num, siginfo_t *info, void *ucontext)
{
        (void)num;
        (void)ucontext;

        (void)feclearexcept(FE_ALL_EXCEPT);
        (void)memcpy((void *)&saved_siginfo, info, sizeof(saved_siginfo));

#if 0
        siglongjmp(jmp_env, 1);
#else
        throw std::invalid_argument( "you violated the fp math rules" );
#endif
}

int main(int ac, char *av[])
{
        struct sigaction action;
        int ret;
        int i = 0, j = 0;

        (void)puts("#start.");

        (void)memset(&action, 0, sizeof action);

        action.sa_sigaction = sigfpe_handler;
        (void)sigemptyset(&action.sa_mask);
        action.sa_flags = SA_SIGINFO;
        (void)sigaction(SIGFPE, &action, NULL);


        try
        {
                ret = sigsetjmp(jmp_env, 1);
                if (ret) {
                        (void)puts("#got_signal");
                }
                else
                {
                        (void)puts("#begin_math");
                        i = i / j;
                        (void)puts("#end_math");
                }
        }
        catch( const std::invalid_argument &e )
        {
                std::cout << std::string("#got_exception ")+e.what()+" \n";
        }

        (void)printf("i=%d, j=%d\n", i, j);

        (void)puts("#end.");
        return EXIT_SUCCESS;
}