/*-------------------------------------------------------------------------

 * link-canary.c

 *    Detect whether src/common functions came from frontend or backend.

 *

 * Copyright (c) 2018-2025, PostgreSQL Global Development Group

 *

 * IDENTIFICATION

 *    src/common/link-canary.c

 *

 *-------------------------------------------------------------------------

 */

#include "c.h"

#include "common/link-canary.h"

/*

 * This function just reports whether this file was compiled for frontend

 * or backend environment.  We need this because in some systems, mainly

 * ELF-based platforms, it is possible for a shlib (such as libpq) loaded

 * into the backend to call a backend function named XYZ in preference to

 * the shlib's own function XYZ.  That's bad if the two functions don't

 * act identically.  This exact situation comes up for many functions in

 * src/common and src/port, where the same function names exist in both

 * libpq and the backend but they don't act quite identically.  To verify

 * that appropriate measures have been taken to prevent incorrect symbol

 * resolution, libpq should test that this function returns true.

 */

bool

pg_link_canary_is_frontend(void)

{

#ifdef FRONTEND

  return true;

#else

  return false;

#endif

}