1 /* Traditional frame unwind support, for GDB the GNU Debugger.
3 Copyright (C) 2003-2018 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
22 #include "trad-frame.h"
24 #include "frame-unwind.h"
27 struct trad_frame_cache
29 struct frame_info *this_frame;
31 struct trad_frame_saved_reg *prev_regs;
32 struct frame_id this_id;
35 struct trad_frame_cache *
36 trad_frame_cache_zalloc (struct frame_info *this_frame)
38 struct trad_frame_cache *this_trad_cache;
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;
46 struct trad_frame_saved_reg *
47 trad_frame_alloc_saved_regs (struct gdbarch *gdbarch)
50 int numregs = gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
51 struct trad_frame_saved_reg *this_saved_regs
52 = FRAME_OBSTACK_CALLOC (numregs, struct trad_frame_saved_reg);
54 for (regnum = 0; regnum < numregs; regnum++)
56 this_saved_regs[regnum].realreg = regnum;
57 this_saved_regs[regnum].addr = -1;
59 return this_saved_regs;
62 /* A traditional frame is unwound by analysing the function prologue
63 and using the information gathered to track registers. For
64 non-optimized frames, the technique is reliable (just need to check
65 for all potential instruction sequences). */
67 struct trad_frame_saved_reg *
68 trad_frame_alloc_saved_regs (struct frame_info *this_frame)
70 struct gdbarch *gdbarch = get_frame_arch (this_frame);
72 return trad_frame_alloc_saved_regs (gdbarch);
75 enum { TF_REG_VALUE = -1, TF_REG_UNKNOWN = -2 };
78 trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
80 return (this_saved_regs[regnum].realreg == TF_REG_VALUE);
84 trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[], int regnum)
86 return (this_saved_regs[regnum].realreg >= 0
87 && this_saved_regs[regnum].addr != -1);
91 trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[],
94 return (this_saved_regs[regnum].realreg >= 0
95 && this_saved_regs[regnum].addr == -1);
99 trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[],
100 int regnum, LONGEST val)
102 /* Make the REALREG invalid, indicating that the ADDR contains the
104 this_saved_regs[regnum].realreg = TF_REG_VALUE;
105 this_saved_regs[regnum].addr = val;
108 /* See trad-frame.h. */
111 trad_frame_set_realreg (struct trad_frame_saved_reg this_saved_regs[],
112 int regnum, int realreg)
114 this_saved_regs[regnum].realreg = realreg;
115 this_saved_regs[regnum].addr = -1;
118 /* See trad-frame.h. */
121 trad_frame_set_addr (struct trad_frame_saved_reg this_saved_regs[],
122 int regnum, CORE_ADDR addr)
124 this_saved_regs[regnum].realreg = regnum;
125 this_saved_regs[regnum].addr = addr;
129 trad_frame_set_reg_value (struct trad_frame_cache *this_trad_cache,
130 int regnum, LONGEST val)
132 /* External interface for users of trad_frame_cache
133 (who cannot access the prev_regs object directly). */
134 trad_frame_set_value (this_trad_cache->prev_regs, regnum, val);
138 trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache,
139 int regnum, int realreg)
141 trad_frame_set_realreg (this_trad_cache->prev_regs, regnum, realreg);
145 trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache,
146 int regnum, CORE_ADDR addr)
148 trad_frame_set_addr (this_trad_cache->prev_regs, regnum, addr);
152 trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[],
155 /* Make the REALREG invalid, indicating that the value is not known. */
156 this_saved_regs[regnum].realreg = TF_REG_UNKNOWN;
157 this_saved_regs[regnum].addr = -1;
161 trad_frame_get_prev_register (struct frame_info *this_frame,
162 struct trad_frame_saved_reg this_saved_regs[],
165 if (trad_frame_addr_p (this_saved_regs, regnum))
166 /* The register was saved in memory. */
167 return frame_unwind_got_memory (this_frame, regnum,
168 this_saved_regs[regnum].addr);
169 else if (trad_frame_realreg_p (this_saved_regs, regnum))
170 return frame_unwind_got_register (this_frame, regnum,
171 this_saved_regs[regnum].realreg);
172 else if (trad_frame_value_p (this_saved_regs, regnum))
173 /* The register's value is available. */
174 return frame_unwind_got_constant (this_frame, regnum,
175 this_saved_regs[regnum].addr);
177 return frame_unwind_got_optimized (this_frame, regnum);
181 trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
182 struct frame_info *this_frame,
185 return trad_frame_get_prev_register (this_frame, this_trad_cache->prev_regs,
190 trad_frame_set_id (struct trad_frame_cache *this_trad_cache,
191 struct frame_id this_id)
193 this_trad_cache->this_id = this_id;
197 trad_frame_get_id (struct trad_frame_cache *this_trad_cache,
198 struct frame_id *this_id)
200 (*this_id) = this_trad_cache->this_id;
204 trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache,
207 this_trad_cache->this_base = this_base;
211 trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache)
213 return this_trad_cache->this_base;