memcheck/tests/realloc_size_zero.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <errno.h>
   4
   5 int main(void)
   6 {
   7
   8    char* p = malloc(1024);
   9    p[0] = '\0';
  10    errno = 0;
  11    p = realloc(p, 0);
  12    if (p) {
  13       printf("p not NULL after realloc 0\n");
  14    } else {
  15       printf("p is NULL after realloc 0\n");
  16    }
  17    if (errno) {
  18       perror("realloc(something, 0):");
  19    }
  20    if (p) {
  21       free(p);
  22    }
  23
  24    errno = 0;
  25    void *ptr = NULL;
  26    volatile size_t size = 0U;
  27    char *p2 = realloc(ptr, size);
  28    if (p2) {
  29       printf("p2 not NULL after realloc 0\n");
  30    } else {
  31       printf("p2 is NULL after realloc 0\n");
  32    }
  33    if (errno) {
  34       perror("realloc(NULL, 0):");
  35    }
  36    if (p2) {
  37       free(p2);
  38    }
  39 }