| 1 | /* User visible, per-frame registers, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2002-2014 Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by Red Hat. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 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. |
| 13 | |
| 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. |
| 18 | |
| 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/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "user-regs.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include <string.h> |
| 26 | #include "gdb_assert.h" |
| 27 | #include "frame.h" |
| 28 | |
| 29 | /* A table of user registers. |
| 30 | |
| 31 | User registers have regnum's that live above of the range [0 |
| 32 | .. gdbarch_num_regs + gdbarch_num_pseudo_regs) |
| 33 | (which is controlled by the target). |
| 34 | The target should never see a user register's regnum value. |
| 35 | |
| 36 | Always append, never delete. By doing this, the relative regnum |
| 37 | (offset from gdbarch_num_regs + gdbarch_num_pseudo_regs) |
| 38 | assigned to each user register never changes. */ |
| 39 | |
| 40 | struct user_reg |
| 41 | { |
| 42 | const char *name; |
| 43 | struct value *(*read) (struct frame_info * frame, const void *baton); |
| 44 | const void *baton; |
| 45 | struct user_reg *next; |
| 46 | }; |
| 47 | |
| 48 | /* This structure is named gdb_user_regs instead of user_regs to avoid |
| 49 | conflicts with any "struct user_regs" in system headers. For instance, |
| 50 | on ARM GNU/Linux native builds, nm-linux.h includes <signal.h> includes |
| 51 | <sys/ucontext.h> includes <sys/procfs.h> includes <sys/user.h>, which |
| 52 | declares "struct user_regs". */ |
| 53 | |
| 54 | struct gdb_user_regs |
| 55 | { |
| 56 | struct user_reg *first; |
| 57 | struct user_reg **last; |
| 58 | }; |
| 59 | |
| 60 | static void |
| 61 | append_user_reg (struct gdb_user_regs *regs, const char *name, |
| 62 | user_reg_read_ftype *read, const void *baton, |
| 63 | struct user_reg *reg) |
| 64 | { |
| 65 | /* The caller is responsible for allocating memory needed to store |
| 66 | the register. By doing this, the function can operate on a |
| 67 | register list stored in the common heap or a specific obstack. */ |
| 68 | gdb_assert (reg != NULL); |
| 69 | reg->name = name; |
| 70 | reg->read = read; |
| 71 | reg->baton = baton; |
| 72 | reg->next = NULL; |
| 73 | (*regs->last) = reg; |
| 74 | regs->last = &(*regs->last)->next; |
| 75 | } |
| 76 | |
| 77 | /* An array of the builtin user registers. */ |
| 78 | |
| 79 | static struct gdb_user_regs builtin_user_regs = { |
| 80 | NULL, &builtin_user_regs.first |
| 81 | }; |
| 82 | |
| 83 | void |
| 84 | user_reg_add_builtin (const char *name, user_reg_read_ftype *read, |
| 85 | const void *baton) |
| 86 | { |
| 87 | append_user_reg (&builtin_user_regs, name, read, baton, |
| 88 | XNEW (struct user_reg)); |
| 89 | } |
| 90 | |
| 91 | /* Per-architecture user registers. Start with the builtin user |
| 92 | registers and then, again, append. */ |
| 93 | |
| 94 | static struct gdbarch_data *user_regs_data; |
| 95 | |
| 96 | static void * |
| 97 | user_regs_init (struct gdbarch *gdbarch) |
| 98 | { |
| 99 | struct user_reg *reg; |
| 100 | struct gdb_user_regs *regs |
| 101 | = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct gdb_user_regs); |
| 102 | |
| 103 | regs->last = ®s->first; |
| 104 | for (reg = builtin_user_regs.first; reg != NULL; reg = reg->next) |
| 105 | append_user_reg (regs, reg->name, reg->read, reg->baton, |
| 106 | GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg)); |
| 107 | return regs; |
| 108 | } |
| 109 | |
| 110 | void |
| 111 | user_reg_add (struct gdbarch *gdbarch, const char *name, |
| 112 | user_reg_read_ftype *read, const void *baton) |
| 113 | { |
| 114 | struct gdb_user_regs *regs = gdbarch_data (gdbarch, user_regs_data); |
| 115 | |
| 116 | if (regs == NULL) |
| 117 | { |
| 118 | /* ULGH, called during architecture initialization. Patch |
| 119 | things up. */ |
| 120 | regs = user_regs_init (gdbarch); |
| 121 | deprecated_set_gdbarch_data (gdbarch, user_regs_data, regs); |
| 122 | } |
| 123 | append_user_reg (regs, name, read, baton, |
| 124 | GDBARCH_OBSTACK_ZALLOC (gdbarch, struct user_reg)); |
| 125 | } |
| 126 | |
| 127 | int |
| 128 | user_reg_map_name_to_regnum (struct gdbarch *gdbarch, const char *name, |
| 129 | int len) |
| 130 | { |
| 131 | /* Make life easy, set the len to something reasonable. */ |
| 132 | if (len < 0) |
| 133 | len = strlen (name); |
| 134 | |
| 135 | /* Search register name space first - always let an architecture |
| 136 | specific register override the user registers. */ |
| 137 | { |
| 138 | int i; |
| 139 | int maxregs = (gdbarch_num_regs (gdbarch) |
| 140 | + gdbarch_num_pseudo_regs (gdbarch)); |
| 141 | |
| 142 | for (i = 0; i < maxregs; i++) |
| 143 | { |
| 144 | const char *regname = gdbarch_register_name (gdbarch, i); |
| 145 | |
| 146 | if (regname != NULL && len == strlen (regname) |
| 147 | && strncmp (regname, name, len) == 0) |
| 148 | { |
| 149 | return i; |
| 150 | } |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /* Search the user name space. */ |
| 155 | { |
| 156 | struct gdb_user_regs *regs = gdbarch_data (gdbarch, user_regs_data); |
| 157 | struct user_reg *reg; |
| 158 | int nr; |
| 159 | |
| 160 | for (nr = 0, reg = regs->first; reg != NULL; reg = reg->next, nr++) |
| 161 | { |
| 162 | if ((len < 0 && strcmp (reg->name, name)) |
| 163 | || (len == strlen (reg->name) |
| 164 | && strncmp (reg->name, name, len) == 0)) |
| 165 | return gdbarch_num_regs (gdbarch) |
| 166 | + gdbarch_num_pseudo_regs (gdbarch) + nr; |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | return -1; |
| 171 | } |
| 172 | |
| 173 | static struct user_reg * |
| 174 | usernum_to_user_reg (struct gdbarch *gdbarch, int usernum) |
| 175 | { |
| 176 | struct gdb_user_regs *regs = gdbarch_data (gdbarch, user_regs_data); |
| 177 | struct user_reg *reg; |
| 178 | |
| 179 | for (reg = regs->first; reg != NULL; reg = reg->next) |
| 180 | { |
| 181 | if (usernum == 0) |
| 182 | return reg; |
| 183 | usernum--; |
| 184 | } |
| 185 | return NULL; |
| 186 | } |
| 187 | |
| 188 | const char * |
| 189 | user_reg_map_regnum_to_name (struct gdbarch *gdbarch, int regnum) |
| 190 | { |
| 191 | int maxregs = (gdbarch_num_regs (gdbarch) |
| 192 | + gdbarch_num_pseudo_regs (gdbarch)); |
| 193 | |
| 194 | if (regnum < 0) |
| 195 | return NULL; |
| 196 | else if (regnum < maxregs) |
| 197 | return gdbarch_register_name (gdbarch, regnum); |
| 198 | else |
| 199 | { |
| 200 | struct user_reg *reg = usernum_to_user_reg (gdbarch, regnum - maxregs); |
| 201 | if (reg == NULL) |
| 202 | return NULL; |
| 203 | else |
| 204 | return reg->name; |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | struct value * |
| 209 | value_of_user_reg (int regnum, struct frame_info *frame) |
| 210 | { |
| 211 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 212 | int maxregs = (gdbarch_num_regs (gdbarch) |
| 213 | + gdbarch_num_pseudo_regs (gdbarch)); |
| 214 | struct user_reg *reg = usernum_to_user_reg (gdbarch, regnum - maxregs); |
| 215 | |
| 216 | gdb_assert (reg != NULL); |
| 217 | return reg->read (frame, reg->baton); |
| 218 | } |
| 219 | |
| 220 | extern initialize_file_ftype _initialize_user_regs; /* -Wmissing-prototypes */ |
| 221 | |
| 222 | void |
| 223 | _initialize_user_regs (void) |
| 224 | { |
| 225 | user_regs_data = gdbarch_data_register_post_init (user_regs_init); |
| 226 | } |