/* libc-internal interface for tagged (colored) memory support.
   Copyright (C) 2020-2024 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#ifndef _GENERIC_LIBC_MTAG_H
#define _GENERIC_LIBC_MTAG_H 1

/* Generic bindings for systems that do not support memory tagging.  */

/* Used to ensure additional alignment when objects need to have distinct
   tags.  */
#define __MTAG_GRANULE_SIZE 1

/* Non-zero if memory obtained via morecore (sbrk) is not tagged.  */
#define __MTAG_SBRK_UNTAGGED 0

/* Extra flags to pass to mmap() to request a tagged region of memory.  */
#define __MTAG_MMAP_FLAGS 0

/* Memory tagging target hooks are only called when memory tagging is
   enabled at runtime.  The generic definitions here must not be used.  */
void __libc_mtag_link_error (void);

/* Set the tags for a region of memory, which must have size and alignment
   that are multiples of __MTAG_GRANULE_SIZE.  Size cannot be zero.  */
static inline void *
__libc_mtag_tag_region (void *p, size_t n)
{
  __libc_mtag_link_error ();
  return p;
}

/* Optimized equivalent to __libc_mtag_tag_region followed by memset to 0.  */
static inline void *
__libc_mtag_tag_zero_region (void *p, size_t n)
{
  __libc_mtag_link_error ();
  return memset (p, 0, n);
}

/* Convert address P to a pointer that is tagged correctly for that
   location.  */
static inline void *
__libc_mtag_address_get_tag (void *p)
{
  __libc_mtag_link_error ();
  return p;
}

/* Assign a new (random) tag to a pointer P (does not adjust the tag on
   the memory addressed).  */
static inline void *
__libc_mtag_new_tag (void *p)
{
  __libc_mtag_link_error ();
  return p;
}

#endif /* _GENERIC_LIBC_MTAG_H */