c - What does this mean?: *(int32 *) 0 = 0; -

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in following piece of code, *(int32 *) 0 = 0; mean?

void function (void) {   ...    (;;)      *(int32 *) 0 = 0;     /* line do? */ }

a few notes:

  • the code seems not reachable, there exit statement before particular piece of code.
  • int32 typedef'ed shouldn't care it.
  • this piece of code language's runtime in compiler, interested.

the code doing following:

   (;;) // while(true)      *(int32 *) 0 = 0; // treat 0 address, de-reference 0 address , try , store 0 it.

this should segfault, null pointer de-reference.

edit

compiled , ran further information:

#include <stdio.h> #include <stdlib.h> #include <stdint.h>  int main(void){   *(int32_t *) 0 = 0;   printf("done\n");   return 0; }

gcc -g null.c; ./a.out

program received signal sigsegv, segmentation fault. 0x00000000004004cd in main () @ null.c:7 7         *(int32_t *) 0 = 0;

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