binutils-gdb/gdb/user-regs.c

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/* User visible, per-frame registers, for GDB, the GNU debugger.
Copyright 2002 Free Software Foundation, Inc.
Contributed by Red Hat.
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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "user-regs.h"
#include "gdbtypes.h"
#include "gdb_string.h"
#include "gdb_assert.h"
#include "frame.h"
/* A table of user registers.
User registers have regnum's that live above of the range [0
.. NUM_REGS + NUM_PSEUDO_REGS) (which is controlled by the target).
The target should never see a user register's regnum value.
Always append, never delete. By doing this, the relative regnum
(offset from NUM_REGS + NUM_PSEUDO_REGS) assigned to each user
register never changes. */
struct user_reg
{
const char *name;
struct value *(*read) (struct frame_info * frame);
struct user_reg *next;
};
struct user_regs
{
struct user_reg *first;
struct user_reg **last;
};
static void
append_user_reg (struct user_regs *regs, const char *name,
user_reg_read_ftype *read, struct user_reg *reg)
{
/* The caller is responsible for allocating memory needed to store
the register. By doing this, the function can operate on a
register list stored in the common heap or a specific obstack. */
gdb_assert (reg != NULL);
reg->name = name;
reg->read = read;
reg->next = NULL;
(*regs->last) = reg;
regs->last = &(*regs->last)->next;
}
/* An array of the builtin user registers. */
static struct user_regs builtin_user_regs = { NULL, &builtin_user_regs.first };
void
user_reg_add_builtin (const char *name, user_reg_read_ftype *read)
{
append_user_reg (&builtin_user_regs, name, read,
XMALLOC (struct user_reg));
}
/* Per-architecture user registers. Start with the builtin user
registers and then, again, append. */
static struct gdbarch_data *user_regs_data;
static void *
user_regs_init (struct gdbarch *gdbarch)
{
struct user_reg *reg;
struct user_regs *regs = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_regs);
regs->last = &regs->first;
for (reg = builtin_user_regs.first; reg != NULL; reg = reg->next)
append_user_reg (regs, reg->name, reg->read,
GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg));
return regs;
}
void
user_reg_add (struct gdbarch *gdbarch, const char *name,
user_reg_read_ftype *read)
{
struct user_regs *regs = gdbarch_data (gdbarch, user_regs_data);
if (regs == NULL)
{
/* ULGH, called during architecture initialization. Patch
things up. */
regs = user_regs_init (gdbarch);
set_gdbarch_data (gdbarch, user_regs_data, regs);
}
append_user_reg (regs, name, read,
GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg));
}
int
user_reg_map_name_to_regnum (struct gdbarch *gdbarch, const char *name,
int len)
{
/* Make life easy, set the len to something reasonable. */
if (len < 0)
len = strlen (name);
/* Search register name space first - always let an architecture
specific register override the user registers. */
{
int i;
int maxregs = (gdbarch_num_regs (gdbarch)
+ gdbarch_num_pseudo_regs (gdbarch));
for (i = 0; i < maxregs; i++)
{
const char *regname = gdbarch_register_name (gdbarch, i);
if (regname != NULL && len == strlen (regname)
&& strncmp (regname, name, len) == 0)
{
return i;
}
}
}
/* Search the user name space. */
{
struct user_regs *regs = gdbarch_data (gdbarch, user_regs_data);
struct user_reg *reg;
int nr;
for (nr = 0, reg = regs->first; reg != NULL; reg = reg->next, nr++)
{
if ((len < 0 && strcmp (reg->name, name))
|| (len == strlen (reg->name)
&& strncmp (reg->name, name, len) == 0))
return NUM_REGS + NUM_PSEUDO_REGS + nr;
}
}
return -1;
}
static struct user_reg *
usernum_to_user_reg (struct gdbarch *gdbarch, int usernum)
{
struct user_regs *regs = gdbarch_data (gdbarch, user_regs_data);
struct user_reg *reg;
for (reg = regs->first; reg != NULL; reg = reg->next)
{
if (usernum == 0)
return reg;
usernum--;
}
return NULL;
}
const char *
user_reg_map_regnum_to_name (struct gdbarch *gdbarch, int regnum)
{
int maxregs = (gdbarch_num_regs (gdbarch)
+ gdbarch_num_pseudo_regs (gdbarch));
if (regnum < 0)
return NULL;
else if (regnum < maxregs)
return gdbarch_register_name (gdbarch, regnum);
else
{
struct user_reg *reg = usernum_to_user_reg (gdbarch, regnum - maxregs);
if (reg == NULL)
return NULL;
else
return reg->name;
}
}
struct value *
value_of_user_reg (int regnum, struct frame_info *frame)
{
struct gdbarch *gdbarch = get_frame_arch (frame);
int maxregs = (gdbarch_num_regs (gdbarch)
+ gdbarch_num_pseudo_regs (gdbarch));
struct user_reg *reg = usernum_to_user_reg (gdbarch, regnum - maxregs);
gdb_assert (reg != NULL);
return reg->read (frame);
}
extern initialize_file_ftype _initialize_user_regs; /* -Wmissing-prototypes */
void
_initialize_user_regs (void)
{
user_regs_data = register_gdbarch_data (user_regs_init);
}