Problem while executing a custom testcase inside testsuite

[Akshat Garg]

Hello all,

I have been trying to run a test which assigns a value from non-atomic to
an atomic pointer type. The code is as follows:

/* File: xyz.c  */
/* { dg-do compile } */
/* { dg-options "-std=c11 -pedantic-errors" } */

#include <stdatomic.h>

typedef __SIZE_TYPE__ size_t;
extern void abort (void);
extern void exit (int);
extern void *malloc (size_t);


struct rcutest
{
  int a;
  int b;
  int c;
};

_Atomic struct rcutest *gp;

#define rcu_assign_pointer(p,v) \
  atomic_store_explicit(&(p), (v), memory_order_release);

#define rcu_dereference(p) \
  atomic_load_explicit(&(p), memory_order_consume);

void thread0 ()
{
  struct rcutest *p;
  p = (struct rcutest *)malloc (sizeof (*p));
  if (p)
    abort();
  p->a = 42;
  if (p->a == 43)
    abort();
  rcu_assign_pointer (gp,p);
}

The test is inside the gcc.dg directory of the testsuite.
The command used to run the specific test: make -k check-c
RUNTESTFLAG="dg.exp=xyz.c"

I believe I should be getting a warning like:
warning: initialization from incompatible pointer type
[-Wincompatible-pointer-types]
but in the gcc.log file, I found this:
error: initialization of '_Atomic struct rcutest *' from incompatible
pointer type 'struct rcutest *' [-Wincompatible-pointer-types]

Can anyone please explain to me why this is considered as an error, not a
warning?

Thanks,
Akshat