test24.c: In function 'func1':
test24.c:33:5: warning: Using variable 'ptr1' without checking for null pointer
     ptr1();
     ^
test24.c: In function 'func3':
test24.c:45:5: warning: Using variable 'data' without checking for null pointer
     data->fptr1(ptr1);
     ^
test24.c:45:5: warning: Using variable 'data->fptr1' without checking for null pointer
test24.c: In function 'func4':
test24.c:51:5: warning: Using variable 'ptr1' without checking for null pointer
     ptr1->fptr1(ptr2);
     ^
test24.c:51:5: warning: Using variable 'ptr1->fptr1' without checking for null pointer
test24.c: In function 'func5':
test24.c:58:5: warning: Using variable 'data' without checking for null pointer
     (*data->fptr2[1])(ptr1);
     ^
test24.c:58:5: warning: Using variable 'data->fptr2' without checking for null pointer
test24.c:58:5: warning: Using variable 'data' without checking for null pointer
test24.c:58:5: warning: Using variable 'data->fptr2' without checking for null pointer
test24.c:58:5: warning: Using variable 'ptr1' without checking for null pointer
test24.c: In function 'func6':
test24.c:64:11: warning: Using variable 'ptr1' without checking for null pointer
     (*ptr1[1])(data);
           ^
test24.c:64:5: warning: Using variable 'data' without checking for null pointer
     (*ptr1[1])(data);
     ^
test24.c: In function 'func7':
test24.c:80:13: warning: Using variable 'w1' without checking for null pointer
         if ((*fptr[i])(w1,w2))
             ^
test24.c: In function 'func8':
test24.c:87:9: warning: Using variable 'fptr' without checking for null pointer
     fptr[1]("", "");
         ^