1 /* User visible, per-frame registers, for GDB, the GNU debugger.
3 Copyright (C) 2002-2024 Free Software Foundation, Inc.
5 Contributed by Red Hat.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "user-regs.h"
26 #include "arch-utils.h"
28 #include "cli/cli-cmds.h"
30 /* A table of user registers.
32 User registers have regnum's that live above of the range [0
33 .. gdbarch_num_regs + gdbarch_num_pseudo_regs)
34 (which is controlled by the target).
35 The target should never see a user register's regnum value.
37 Always append, never delete. By doing this, the relative regnum
38 (offset from gdbarch_num_regs + gdbarch_num_pseudo_regs)
39 assigned to each user register never changes. */
44 /* Avoid the "read" symbol name as it conflicts with a preprocessor symbol
45 in the NetBSD header for Stack Smashing Protection, that wraps the read(2)
47 struct value
*(*xread
) (frame_info_ptr frame
, const void *baton
);
49 struct user_reg
*next
;
52 /* This structure is named gdb_user_regs instead of user_regs to avoid
53 conflicts with any "struct user_regs" in system headers. For instance,
54 on ARM GNU/Linux native builds, nm-linux.h includes <signal.h> includes
55 <sys/ucontext.h> includes <sys/procfs.h> includes <sys/user.h>, which
56 declares "struct user_regs". */
60 struct user_reg
*first
= nullptr;
61 struct user_reg
**last
= nullptr;
65 append_user_reg (struct gdb_user_regs
*regs
, const char *name
,
66 user_reg_read_ftype
*xread
, const void *baton
,
69 /* The caller is responsible for allocating memory needed to store
70 the register. By doing this, the function can operate on a
71 register list stored in the common heap or a specific obstack. */
72 gdb_assert (reg
!= NULL
);
77 if (regs
->last
== nullptr)
78 regs
->last
= ®s
->first
;
80 regs
->last
= &(*regs
->last
)->next
;
83 /* An array of the builtin user registers. */
85 static struct gdb_user_regs builtin_user_regs
;
88 user_reg_add_builtin (const char *name
, user_reg_read_ftype
*xread
,
91 append_user_reg (&builtin_user_regs
, name
, xread
, baton
,
92 XNEW (struct user_reg
));
95 /* Per-architecture user registers. Start with the builtin user
96 registers and then, again, append. */
98 static const registry
<gdbarch
>::key
<gdb_user_regs
> user_regs_data
;
100 static gdb_user_regs
*
101 get_user_regs (struct gdbarch
*gdbarch
)
103 struct gdb_user_regs
*regs
= user_regs_data
.get (gdbarch
);
106 regs
= new struct gdb_user_regs
;
108 struct obstack
*obstack
= gdbarch_obstack (gdbarch
);
109 regs
->last
= ®s
->first
;
110 for (user_reg
*reg
= builtin_user_regs
.first
;
113 append_user_reg (regs
, reg
->name
, reg
->xread
, reg
->baton
,
114 OBSTACK_ZALLOC (obstack
, struct user_reg
));
115 user_regs_data
.set (gdbarch
, regs
);
122 user_reg_add (struct gdbarch
*gdbarch
, const char *name
,
123 user_reg_read_ftype
*xread
, const void *baton
)
125 struct gdb_user_regs
*regs
= get_user_regs (gdbarch
);
126 gdb_assert (regs
!= NULL
);
127 append_user_reg (regs
, name
, xread
, baton
,
128 GDBARCH_OBSTACK_ZALLOC (gdbarch
, struct user_reg
));
132 user_reg_map_name_to_regnum (struct gdbarch
*gdbarch
, const char *name
,
135 /* Make life easy, set the len to something reasonable. */
139 /* Search register name space first - always let an architecture
140 specific register override the user registers. */
142 int maxregs
= gdbarch_num_cooked_regs (gdbarch
);
144 for (int i
= 0; i
< maxregs
; i
++)
146 const char *regname
= gdbarch_register_name (gdbarch
, i
);
148 if (len
== strlen (regname
) && strncmp (regname
, name
, len
) == 0)
153 /* Search the user name space. */
155 struct gdb_user_regs
*regs
= get_user_regs (gdbarch
);
156 struct user_reg
*reg
;
159 for (nr
= 0, reg
= regs
->first
; reg
!= NULL
; reg
= reg
->next
, nr
++)
161 if ((len
< 0 && strcmp (reg
->name
, name
))
162 || (len
== strlen (reg
->name
)
163 && strncmp (reg
->name
, name
, len
) == 0))
164 return gdbarch_num_cooked_regs (gdbarch
) + nr
;
171 static struct user_reg
*
172 usernum_to_user_reg (struct gdbarch
*gdbarch
, int usernum
)
174 struct gdb_user_regs
*regs
= get_user_regs (gdbarch
);
175 struct user_reg
*reg
;
177 for (reg
= regs
->first
; reg
!= NULL
; reg
= reg
->next
)
187 user_reg_map_regnum_to_name (struct gdbarch
*gdbarch
, int regnum
)
189 int maxregs
= gdbarch_num_cooked_regs (gdbarch
);
193 else if (regnum
< maxregs
)
194 return gdbarch_register_name (gdbarch
, regnum
);
197 struct user_reg
*reg
= usernum_to_user_reg (gdbarch
, regnum
- maxregs
);
206 value_of_user_reg (int regnum
, frame_info_ptr frame
)
208 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
209 int maxregs
= gdbarch_num_cooked_regs (gdbarch
);
210 struct user_reg
*reg
= usernum_to_user_reg (gdbarch
, regnum
- maxregs
);
212 gdb_assert (reg
!= NULL
);
213 return reg
->xread (frame
, reg
->baton
);
217 maintenance_print_user_registers (const char *args
, int from_tty
)
219 struct gdbarch
*gdbarch
= get_current_arch ();
220 struct user_reg
*reg
;
223 struct gdb_user_regs
*regs
= get_user_regs (gdbarch
);
224 regnum
= gdbarch_num_cooked_regs (gdbarch
);
226 gdb_printf (" %-11s %3s\n", "Name", "Nr");
227 for (reg
= regs
->first
; reg
!= NULL
; reg
= reg
->next
, ++regnum
)
228 gdb_printf (" %-11s %3d\n", reg
->name
, regnum
);
231 void _initialize_user_regs ();
233 _initialize_user_regs ()
235 add_cmd ("user-registers", class_maintenance
,
236 maintenance_print_user_registers
,
237 _("List the names of the current user registers."),
238 &maintenanceprintlist
);