| 1 | /* Traditional frame unwind support, for GDB the GNU Debugger. |
| 2 | |
| 3 | Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 20 | Boston, MA 02110-1301, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "frame.h" |
| 24 | #include "trad-frame.h" |
| 25 | #include "regcache.h" |
| 26 | |
| 27 | struct trad_frame_cache |
| 28 | { |
| 29 | struct frame_info *next_frame; |
| 30 | CORE_ADDR this_base; |
| 31 | struct trad_frame_saved_reg *prev_regs; |
| 32 | struct frame_id this_id; |
| 33 | }; |
| 34 | |
| 35 | struct trad_frame_cache * |
| 36 | trad_frame_cache_zalloc (struct frame_info *next_frame) |
| 37 | { |
| 38 | struct trad_frame_cache *this_trad_cache; |
| 39 | |
| 40 | this_trad_cache = FRAME_OBSTACK_ZALLOC (struct trad_frame_cache); |
| 41 | this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (next_frame); |
| 42 | this_trad_cache->next_frame = next_frame; |
| 43 | return this_trad_cache; |
| 44 | } |
| 45 | |
| 46 | /* A traditional frame is unwound by analysing the function prologue |
| 47 | and using the information gathered to track registers. For |
| 48 | non-optimized frames, the technique is reliable (just need to check |
| 49 | for all potential instruction sequences). */ |
| 50 | |
| 51 | struct trad_frame_saved_reg * |
| 52 | trad_frame_alloc_saved_regs (struct frame_info *next_frame) |
| 53 | { |
| 54 | int regnum; |
| 55 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 56 | int numregs = NUM_REGS + NUM_PSEUDO_REGS; |
| 57 | struct trad_frame_saved_reg *this_saved_regs |
| 58 | = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg); |
| 59 | for (regnum = 0; regnum < numregs; regnum++) |
| 60 | { |
| 61 | this_saved_regs[regnum].realreg = regnum; |
| 62 | this_saved_regs[regnum].addr = -1; |
| 63 | } |
| 64 | return this_saved_regs; |
| 65 | } |
| 66 | |
| 67 | enum { REG_VALUE = -1, REG_UNKNOWN = -2 }; |
| 68 | |
| 69 | int |
| 70 | trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) |
| 71 | { |
| 72 | return (this_saved_regs[regnum].realreg == REG_VALUE); |
| 73 | } |
| 74 | |
| 75 | int |
| 76 | trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) |
| 77 | { |
| 78 | return (this_saved_regs[regnum].realreg >= 0 |
| 79 | && this_saved_regs[regnum].addr != -1); |
| 80 | } |
| 81 | |
| 82 | int |
| 83 | trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[], |
| 84 | int regnum) |
| 85 | { |
| 86 | return (this_saved_regs[regnum].realreg >= 0 |
| 87 | && this_saved_regs[regnum].addr == -1); |
| 88 | } |
| 89 | |
| 90 | void |
| 91 | trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[], |
| 92 | int regnum, LONGEST val) |
| 93 | { |
| 94 | /* Make the REALREG invalid, indicating that the ADDR contains the |
| 95 | register's value. */ |
| 96 | this_saved_regs[regnum].realreg = REG_VALUE; |
| 97 | this_saved_regs[regnum].addr = val; |
| 98 | } |
| 99 | |
| 100 | void |
| 101 | trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache, |
| 102 | int regnum, LONGEST val) |
| 103 | { |
| 104 | /* External interface for users of trad_frame_cache |
| 105 | (who cannot access the prev_regs object directly). */ |
| 106 | trad_frame_set_value (this_trad_cache->prev_regs, regnum, val); |
| 107 | } |
| 108 | |
| 109 | void |
| 110 | trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache, |
| 111 | int regnum, int realreg) |
| 112 | { |
| 113 | this_trad_cache->prev_regs[regnum].realreg = realreg; |
| 114 | this_trad_cache->prev_regs[regnum].addr = -1; |
| 115 | } |
| 116 | |
| 117 | void |
| 118 | trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache, |
| 119 | int regnum, CORE_ADDR addr) |
| 120 | { |
| 121 | this_trad_cache->prev_regs[regnum].addr = addr; |
| 122 | } |
| 123 | |
| 124 | void |
| 125 | trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[], |
| 126 | int regnum) |
| 127 | { |
| 128 | /* Make the REALREG invalid, indicating that the value is not known. */ |
| 129 | this_saved_regs[regnum].realreg = REG_UNKNOWN; |
| 130 | this_saved_regs[regnum].addr = -1; |
| 131 | } |
| 132 | |
| 133 | void |
| 134 | trad_frame_get_prev_register (struct frame_info *next_frame, |
| 135 | struct trad_frame_saved_reg this_saved_regs[], |
| 136 | int regnum, int *optimizedp, |
| 137 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 138 | int *realregp, gdb_byte *bufferp) |
| 139 | { |
| 140 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 141 | if (trad_frame_addr_p (this_saved_regs, regnum)) |
| 142 | { |
| 143 | /* The register was saved in memory. */ |
| 144 | *optimizedp = 0; |
| 145 | *lvalp = lval_memory; |
| 146 | *addrp = this_saved_regs[regnum].addr; |
| 147 | *realregp = -1; |
| 148 | if (bufferp != NULL) |
| 149 | { |
| 150 | /* Read the value in from memory. */ |
| 151 | get_frame_memory (next_frame, this_saved_regs[regnum].addr, bufferp, |
| 152 | register_size (gdbarch, regnum)); |
| 153 | } |
| 154 | } |
| 155 | else if (trad_frame_realreg_p (this_saved_regs, regnum)) |
| 156 | { |
| 157 | *optimizedp = 0; |
| 158 | *lvalp = lval_register; |
| 159 | *addrp = 0; |
| 160 | *realregp = this_saved_regs[regnum].realreg; |
| 161 | /* Ask the next frame to return the value of the register. */ |
| 162 | if (bufferp) |
| 163 | frame_unwind_register (next_frame, (*realregp), bufferp); |
| 164 | } |
| 165 | else if (trad_frame_value_p (this_saved_regs, regnum)) |
| 166 | { |
| 167 | /* The register's value is available. */ |
| 168 | *optimizedp = 0; |
| 169 | *lvalp = not_lval; |
| 170 | *addrp = 0; |
| 171 | *realregp = -1; |
| 172 | if (bufferp != NULL) |
| 173 | store_unsigned_integer (bufferp, register_size (gdbarch, regnum), |
| 174 | this_saved_regs[regnum].addr); |
| 175 | } |
| 176 | else |
| 177 | { |
| 178 | error (_("Register %s not available"), |
| 179 | gdbarch_register_name (gdbarch, regnum)); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | void |
| 184 | trad_frame_get_register (struct trad_frame_cache *this_trad_cache, |
| 185 | struct frame_info *next_frame, |
| 186 | int regnum, int *optimizedp, |
| 187 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 188 | int *realregp, gdb_byte *bufferp) |
| 189 | { |
| 190 | trad_frame_get_prev_register (next_frame, this_trad_cache->prev_regs, |
| 191 | regnum, optimizedp, lvalp, addrp, realregp, |
| 192 | bufferp); |
| 193 | } |
| 194 | |
| 195 | void |
| 196 | trad_frame_set_id (struct trad_frame_cache *this_trad_cache, |
| 197 | struct frame_id this_id) |
| 198 | { |
| 199 | this_trad_cache->this_id = this_id; |
| 200 | } |
| 201 | |
| 202 | void |
| 203 | trad_frame_get_id (struct trad_frame_cache *this_trad_cache, |
| 204 | struct frame_id *this_id) |
| 205 | { |
| 206 | (*this_id) = this_trad_cache->this_id; |
| 207 | } |
| 208 | |
| 209 | void |
| 210 | trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache, |
| 211 | CORE_ADDR this_base) |
| 212 | { |
| 213 | this_trad_cache->this_base = this_base; |
| 214 | } |
| 215 | |
| 216 | CORE_ADDR |
| 217 | trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache) |
| 218 | { |
| 219 | return this_trad_cache->this_base; |
| 220 | } |