/* Cache and manage the values of registers

  Copyright (C) 2014-2024 Free Software Foundation, Inc.

  This file is part of GDB.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 3 of the License, or
  (at your option) any later version.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef GDBSUPPORT_COMMON_REGCACHE_H
#define GDBSUPPORT_COMMON_REGCACHE_H

struct reg_buffer_common;

/* This header is a stopgap until we have an independent regcache.  */

enum register_status : signed char
 {
   /* The register value is not in the cache, and we don't know yet
      whether it's available in the target (or traceframe).  */
   REG_UNKNOWN = 0,

   /* The register value is valid and cached.  */
   REG_VALID = 1,

   /* The register value is unavailable.  E.g., we're inspecting a
      traceframe, and this register wasn't collected.  Note that this
      "unavailable" is different from saying the register does not
      exist in the target's architecture --- in that case, the target
      should have given us a target description that does not include
      the register in the first place.  */
   REG_UNAVAILABLE = -1
 };

/* Return a pointer to the register cache associated with the
  thread specified by PTID.  This function must be provided by
  the client.  */

extern reg_buffer_common *get_thread_regcache_for_ptid (ptid_t ptid);

/* Return the size of register numbered N in REGCACHE.  This function
  must be provided by the client.  */

extern int regcache_register_size (const reg_buffer_common *regcache, int n);

/* Read the PC register.  This function must be provided by the
  client.  */

extern CORE_ADDR regcache_read_pc (reg_buffer_common *regcache);

/* Read the PC register.  If PC cannot be read, return 0.
  This is a wrapper around 'regcache_read_pc'.  */

extern CORE_ADDR regcache_read_pc_protected (reg_buffer_common *regcache);

/* Read a raw register into a unsigned integer.  */
extern enum register_status
regcache_raw_read_unsigned (reg_buffer_common *regcache, int regnum,
                           ULONGEST *val);

ULONGEST regcache_raw_get_unsigned (reg_buffer_common *regcache, int regnum);

struct reg_buffer_common
{
 virtual ~reg_buffer_common () = default;

 /* Get the availability status of the value of register REGNUM in this
    buffer.  */
 virtual register_status get_register_status (int regnum) const = 0;

 /* Supply register REGNUM, whose contents are stored in SRC, to this register
    buffer.  */
 virtual void raw_supply (int regnum, gdb::array_view<const gdb_byte> src)
   = 0;

 void raw_supply (int regnum, const uint64_t *src)
 {
   raw_supply (regnum,
               gdb::make_array_view ((const gdb_byte *) src, sizeof (*src)));
 }

 void raw_supply (int regnum, const gdb_byte *src)
 {
   raw_supply (regnum,
               gdb::make_array_view (src,
                                     regcache_register_size (this, regnum)));
 }

 /* Supply part of register REGNUM with zeroed value.  Start at OFFSET in
    the register, with size SIZE.  The rest of the register is left
    untouched.  */
 virtual void raw_supply_part_zeroed (int regnum, int offset, size_t size)
   = 0;

 /* Collect register REGNUM from this register buffer and store its contents in
    DST.  */
 virtual void raw_collect (int regnum, gdb::array_view<gdb_byte> dst) const
   = 0;

 void raw_collect (int regnum, uint64_t *dst) const
 {
   raw_collect (regnum,
                gdb::make_array_view ((gdb_byte *) dst, sizeof (*dst)));
 };

 void raw_collect (int regnum, gdb_byte *dst)
 {
   raw_collect (regnum,
                gdb::make_array_view (dst,
                                      regcache_register_size (this, regnum)));
 }

 /* Compare the contents of the register stored in the regcache (ignoring the
    first OFFSET bytes) to the contents of BUF (without any offset).  Returns
    true if the same.  */
 virtual bool raw_compare (int regnum, const void *buf, int offset) const = 0;
};

#endif /* GDBSUPPORT_COMMON_REGCACHE_H */