/* Cache and manage the values of registers for GDB, the GNU debugger.

   Copyright (C) 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001,
   2002, 2007, 2008, 2009, 2010, 2011 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 REGCACHE_H
#define REGCACHE_H

struct regcache;
struct gdbarch;
struct address_space;

extern struct regcache *get_current_regcache (void);
extern struct regcache *get_thread_regcache (ptid_t ptid);
extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);

void regcache_xfree (struct regcache *regcache);
struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
				   struct address_space *aspace);

/* Return REGCACHE's architecture.  */

extern struct gdbarch *get_regcache_arch (const struct regcache *regcache);

/* Return REGCACHE's address space.  */

extern struct address_space *get_regcache_aspace (const struct regcache *);

enum register_status
  {
    /* 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
       is different a different "unavailable" 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
  };

enum register_status regcache_register_status (const struct regcache *regcache,
					       int regnum);

/* Transfer a raw register [0..NUM_REGS) between core-gdb and the
   regcache.  */

void regcache_raw_read (struct regcache *regcache, int rawnum, gdb_byte *buf);
void regcache_raw_write (struct regcache *regcache, int rawnum,
			 const gdb_byte *buf);
extern void regcache_raw_read_signed (struct regcache *regcache,
				      int regnum, LONGEST *val);
extern void regcache_raw_read_unsigned (struct regcache *regcache,
					int regnum, ULONGEST *val);
extern void regcache_raw_write_signed (struct regcache *regcache,
				       int regnum, LONGEST val);
extern void regcache_raw_write_unsigned (struct regcache *regcache,
					 int regnum, ULONGEST val);

/* Partial transfer of a raw registers.  These perform read, modify,
   write style operations.  */

void regcache_raw_read_part (struct regcache *regcache, int regnum,
			     int offset, int len, gdb_byte *buf);
void regcache_raw_write_part (struct regcache *regcache, int regnum,
			      int offset, int len, const gdb_byte *buf);

void regcache_invalidate (struct regcache *regcache, int regnum);

/* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
void regcache_cooked_read (struct regcache *regcache, int rawnum,
			   gdb_byte *buf);
void regcache_cooked_write (struct regcache *regcache, int rawnum,
			    const gdb_byte *buf);

/* NOTE: cagney/2002-08-13: At present GDB has no reliable mechanism
   for indicating when a ``cooked'' register was constructed from
   invalid or unavailable ``raw'' registers.  One fairly easy way of
   adding such a mechanism would be for the cooked functions to return
   a register valid indication.  Given the possibility of such a
   change, the extract functions below use a reference parameter,
   rather than a function result.  */

/* Read a register as a signed/unsigned quantity.  */
extern void regcache_cooked_read_signed (struct regcache *regcache,
					 int regnum, LONGEST *val);
extern void regcache_cooked_read_unsigned (struct regcache *regcache,
					   int regnum, ULONGEST *val);
extern void regcache_cooked_write_signed (struct regcache *regcache,
					  int regnum, LONGEST val);
extern void regcache_cooked_write_unsigned (struct regcache *regcache,
					    int regnum, ULONGEST val);

/* Partial transfer of a cooked register.  These perform read, modify,
   write style operations.  */

void regcache_cooked_read_part (struct regcache *regcache, int regnum,
				int offset, int len, gdb_byte *buf);
void regcache_cooked_write_part (struct regcache *regcache, int regnum,
				 int offset, int len, const gdb_byte *buf);

/* Special routines to read/write the PC.  */

extern CORE_ADDR regcache_read_pc (struct regcache *regcache);
extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);

/* Transfer a raw register [0..NUM_REGS) between the regcache and the
   target.  These functions are called by the target in response to a
   target_fetch_registers() or target_store_registers().  */

extern void regcache_raw_supply (struct regcache *regcache,
				 int regnum, const void *buf);
extern void regcache_raw_collect (const struct regcache *regcache,
				  int regnum, void *buf);


/* The type of a register.  This function is slightly more efficient
   then its gdbarch vector counterpart since it returns a precomputed
   value stored in a table.  */

extern struct type *register_type (struct gdbarch *gdbarch, int regnum);


/* Return the size of register REGNUM.  All registers should have only
   one size.  */
   
extern int register_size (struct gdbarch *gdbarch, int regnum);


/* Save/restore a register cache.  The set of registers saved /
   restored into the DST regcache determined by the save_reggroup /
   restore_reggroup respectively.  COOKED_READ returns zero iff the
   register's value can't be returned.  */

typedef int (regcache_cooked_read_ftype) (void *src, int regnum,
					  gdb_byte *buf);

extern void regcache_save (struct regcache *dst,
			   regcache_cooked_read_ftype *cooked_read,
			   void *cooked_read_context);
extern void regcache_restore (struct regcache *dst,
			      regcache_cooked_read_ftype *cooked_read,
			      void *cooked_read_context);

/* Copy/duplicate the contents of a register cache.  By default, the
   operation is pass-through.  Writes to DST and reads from SRC will
   go through to the target.

   The ``cpy'' functions can not have overlapping SRC and DST buffers.

   ``no passthrough'' versions do not go through to the target.  They
   only transfer values already in the cache.  */

extern struct regcache *regcache_dup (struct regcache *regcache);
extern void regcache_cpy (struct regcache *dest, struct regcache *src);
extern void regcache_cpy_no_passthrough (struct regcache *dest,
					 struct regcache *src);

extern void registers_changed (void);
extern void registers_changed_ptid (ptid_t);

#endif /* REGCACHE_H */
