1 /* Traditional frame unwind support, for GDB the GNU Debugger. 2 3 Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010, 2011 4 Free Software Foundation, Inc. 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21 #include "defs.h" 22 #include "frame.h" 23 #include "trad-frame.h" 24 #include "regcache.h" 25 #include "frame-unwind.h" 26 #include "value.h" 27 28 struct trad_frame_cache 29 { 30 struct frame_info *this_frame; 31 CORE_ADDR this_base; 32 struct trad_frame_saved_reg *prev_regs; 33 struct frame_id this_id; 34 }; 35 36 struct trad_frame_cache * 37 trad_frame_cache_zalloc (struct frame_info *this_frame) 38 { 39 struct trad_frame_cache *this_trad_cache; 40 41 this_trad_cache = FRAME_OBSTACK_ZALLOC (struct trad_frame_cache); 42 this_trad_cache->prev_regs = trad_frame_alloc_saved_regs (this_frame); 43 this_trad_cache->this_frame = this_frame; 44 return this_trad_cache; 45 } 46 47 /* A traditional frame is unwound by analysing the function prologue 48 and using the information gathered to track registers. For 49 non-optimized frames, the technique is reliable (just need to check 50 for all potential instruction sequences). */ 51 52 struct trad_frame_saved_reg * 53 trad_frame_alloc_saved_regs (struct frame_info *this_frame) 54 { 55 int regnum; 56 struct gdbarch *gdbarch = get_frame_arch (this_frame); 57 int numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); 58 struct trad_frame_saved_reg *this_saved_regs 59 = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg); 60 61 for (regnum = 0; regnum < numregs; regnum++) 62 { 63 this_saved_regs[regnum].realreg = regnum; 64 this_saved_regs[regnum].addr = -1; 65 } 66 return this_saved_regs; 67 } 68 69 enum { TF_REG_VALUE = -1, TF_REG_UNKNOWN = -2 }; 70 71 int 72 trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) 73 { 74 return (this_saved_regs[regnum].realreg == TF_REG_VALUE); 75 } 76 77 int 78 trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum) 79 { 80 return (this_saved_regs[regnum].realreg >= 0 81 && this_saved_regs[regnum].addr != -1); 82 } 83 84 int 85 trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[], 86 int regnum) 87 { 88 return (this_saved_regs[regnum].realreg >= 0 89 && this_saved_regs[regnum].addr == -1); 90 } 91 92 void 93 trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[], 94 int regnum, LONGEST val) 95 { 96 /* Make the REALREG invalid, indicating that the ADDR contains the 97 register's value. */ 98 this_saved_regs[regnum].realreg = TF_REG_VALUE; 99 this_saved_regs[regnum].addr = val; 100 } 101 102 void 103 trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache, 104 int regnum, LONGEST val) 105 { 106 /* External interface for users of trad_frame_cache 107 (who cannot access the prev_regs object directly). */ 108 trad_frame_set_value (this_trad_cache->prev_regs, regnum, val); 109 } 110 111 void 112 trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache, 113 int regnum, int realreg) 114 { 115 this_trad_cache->prev_regs[regnum].realreg = realreg; 116 this_trad_cache->prev_regs[regnum].addr = -1; 117 } 118 119 void 120 trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache, 121 int regnum, CORE_ADDR addr) 122 { 123 this_trad_cache->prev_regs[regnum].addr = addr; 124 } 125 126 void 127 trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[], 128 int regnum) 129 { 130 /* Make the REALREG invalid, indicating that the value is not known. */ 131 this_saved_regs[regnum].realreg = TF_REG_UNKNOWN; 132 this_saved_regs[regnum].addr = -1; 133 } 134 135 struct value * 136 trad_frame_get_prev_register (struct frame_info *this_frame, 137 struct trad_frame_saved_reg this_saved_regs[], 138 int regnum) 139 { 140 if (trad_frame_addr_p (this_saved_regs, regnum)) 141 /* The register was saved in memory. */ 142 return frame_unwind_got_memory (this_frame, regnum, 143 this_saved_regs[regnum].addr); 144 else if (trad_frame_realreg_p (this_saved_regs, regnum)) 145 return frame_unwind_got_register (this_frame, regnum, 146 this_saved_regs[regnum].realreg); 147 else if (trad_frame_value_p (this_saved_regs, regnum)) 148 /* The register's value is available. */ 149 return frame_unwind_got_constant (this_frame, regnum, 150 this_saved_regs[regnum].addr); 151 else 152 return frame_unwind_got_optimized (this_frame, regnum); 153 } 154 155 struct value * 156 trad_frame_get_register (struct trad_frame_cache *this_trad_cache, 157 struct frame_info *this_frame, 158 int regnum) 159 { 160 return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs, 161 regnum); 162 } 163 164 void 165 trad_frame_set_id (struct trad_frame_cache *this_trad_cache, 166 struct frame_id this_id) 167 { 168 this_trad_cache->this_id = this_id; 169 } 170 171 void 172 trad_frame_get_id (struct trad_frame_cache *this_trad_cache, 173 struct frame_id *this_id) 174 { 175 (*this_id) = this_trad_cache->this_id; 176 } 177 178 void 179 trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache, 180 CORE_ADDR this_base) 181 { 182 this_trad_cache->this_base = this_base; 183 } 184 185 CORE_ADDR 186 trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache) 187 { 188 return this_trad_cache->this_base; 189 } 190