1 /* Traditional frame unwind support, for GDB the GNU Debugger. 2 3 Copyright (C) 2003, 2004, 2007, 2008, 2009 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 3 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, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "frame.h" 22 #include "trad-frame.h" 23 #include "regcache.h" 24 #include "frame-unwind.h" 25 #include "value.h" 26 27 struct trad_frame_cache 28 { 29 struct frame_info *this_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 *this_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 (this_frame); 42 this_trad_cache->this_frame = this_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 *this_frame) 53 { 54 int regnum; 55 struct gdbarch *gdbarch = get_frame_arch (this_frame); 56 int numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); 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 struct value * 134 trad_frame_get_prev_register (struct frame_info *this_frame, 135 struct trad_frame_saved_reg this_saved_regs[], 136 int regnum) 137 { 138 struct gdbarch *gdbarch = get_frame_arch (this_frame); 139 if (trad_frame_addr_p (this_saved_regs, regnum)) 140 /* The register was saved in memory. */ 141 return frame_unwind_got_memory (this_frame, regnum, 142 this_saved_regs[regnum].addr); 143 else if (trad_frame_realreg_p (this_saved_regs, regnum)) 144 return frame_unwind_got_register (this_frame, regnum, 145 this_saved_regs[regnum].realreg); 146 else if (trad_frame_value_p (this_saved_regs, regnum)) 147 /* The register's value is available. */ 148 return frame_unwind_got_constant (this_frame, regnum, 149 this_saved_regs[regnum].addr); 150 else 151 return frame_unwind_got_optimized (this_frame, regnum); 152 } 153 154 struct value * 155 trad_frame_get_register (struct trad_frame_cache *this_trad_cache, 156 struct frame_info *this_frame, 157 int regnum) 158 { 159 return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs, 160 regnum); 161 } 162 163 void 164 trad_frame_set_id (struct trad_frame_cache *this_trad_cache, 165 struct frame_id this_id) 166 { 167 this_trad_cache->this_id = this_id; 168 } 169 170 void 171 trad_frame_get_id (struct trad_frame_cache *this_trad_cache, 172 struct frame_id *this_id) 173 { 174 (*this_id) = this_trad_cache->this_id; 175 } 176 177 void 178 trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache, 179 CORE_ADDR this_base) 180 { 181 this_trad_cache->this_base = this_base; 182 } 183 184 CORE_ADDR 185 trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache) 186 { 187 return this_trad_cache->this_base; 188 } 189