1 /* Traditional frame unwind support, for GDB the GNU Debugger. 2 3 Copyright (C) 2003-2013 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 60 for (regnum = 0; regnum < numregs; regnum++) 61 { 62 this_saved_regs[regnum].realreg = regnum; 63 this_saved_regs[regnum].addr = -1; 64 } 65 return this_saved_regs; 66 } 67 68 enum { TF_REG_VALUE = -1, TF_REG_UNKNOWN = -2 }; 69 70 int 71 trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) 72 { 73 return (this_saved_regs[regnum].realreg == TF_REG_VALUE); 74 } 75 76 int 77 trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) 78 { 79 return (this_saved_regs[regnum].realreg >= 0 80 && this_saved_regs[regnum].addr != -1); 81 } 82 83 int 84 trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[], 85 int regnum) 86 { 87 return (this_saved_regs[regnum].realreg >= 0 88 && this_saved_regs[regnum].addr == -1); 89 } 90 91 void 92 trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[], 93 int regnum, LONGEST val) 94 { 95 /* Make the REALREG invalid, indicating that the ADDR contains the 96 register's value. */ 97 this_saved_regs[regnum].realreg = TF_REG_VALUE; 98 this_saved_regs[regnum].addr = val; 99 } 100 101 void 102 trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache, 103 int regnum, LONGEST val) 104 { 105 /* External interface for users of trad_frame_cache 106 (who cannot access the prev_regs object directly). */ 107 trad_frame_set_value (this_trad_cache->prev_regs, regnum, val); 108 } 109 110 void 111 trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache, 112 int regnum, int realreg) 113 { 114 this_trad_cache->prev_regs[regnum].realreg = realreg; 115 this_trad_cache->prev_regs[regnum].addr = -1; 116 } 117 118 void 119 trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache, 120 int regnum, CORE_ADDR addr) 121 { 122 this_trad_cache->prev_regs[regnum].addr = addr; 123 } 124 125 void 126 trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[], 127 int regnum) 128 { 129 /* Make the REALREG invalid, indicating that the value is not known. */ 130 this_saved_regs[regnum].realreg = TF_REG_UNKNOWN; 131 this_saved_regs[regnum].addr = -1; 132 } 133 134 struct value * 135 trad_frame_get_prev_register (struct frame_info *this_frame, 136 struct trad_frame_saved_reg this_saved_regs[], 137 int regnum) 138 { 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