gdb/trad-frame.h

   1 /* Traditional frame unwind support, for GDB the GNU Debugger.
   2
   3    Copyright (C) 2003-2020 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 #ifndef TRAD_FRAME_H
  21 #define TRAD_FRAME_H
  22
  23 #include "frame.h"              /* For "struct frame_id".  */
  24
  25 struct frame_info;
  26 struct regcache_map_entry;
  27 struct trad_frame_cache;
  28
  29 /* A simple, or traditional frame cache.
  30
  31    The entire cache is populated in a single pass and then generic
  32    routines are used to extract the various cache values.  */
  33
  34 struct trad_frame_cache *trad_frame_cache_zalloc (struct frame_info *);
  35
  36 /* This frame's ID.  */
  37 void trad_frame_set_id (struct trad_frame_cache *this_trad_cache,
  38                         struct frame_id this_id);
  39 void trad_frame_get_id (struct trad_frame_cache *this_trad_cache,
  40                         struct frame_id *this_id);
  41 void trad_frame_set_this_base (struct trad_frame_cache *this_trad_cache,
  42                                CORE_ADDR this_base);
  43 CORE_ADDR trad_frame_get_this_base (struct trad_frame_cache *this_trad_cache);
  44
  45 void trad_frame_set_reg_realreg (struct trad_frame_cache *this_trad_cache,
  46                                  int regnum, int realreg);
  47 void trad_frame_set_reg_addr (struct trad_frame_cache *this_trad_cache,
  48                               int regnum, CORE_ADDR addr);
  49 void trad_frame_set_reg_regmap (struct trad_frame_cache *this_trad_cache,
  50                                 const struct regcache_map_entry *regmap,
  51                                 CORE_ADDR addr, size_t size);
  52 void trad_frame_set_reg_value (struct trad_frame_cache *this_cache,
  53                                int regnum, LONGEST val);
  54
  55 struct value *trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
  56                                        struct frame_info *this_frame,
  57                                        int regnum);
  58
  59 /* A traditional saved regs table, indexed by REGNUM, encoding where
  60    the value of REGNUM for the previous frame can be found in this
  61    frame.
  62
  63    The table is initialized with an identity encoding (ADDR == -1,
  64    REALREG == REGNUM) indicating that the value of REGNUM in the
  65    previous frame can be found in register REGNUM (== REALREG) in this
  66    frame.
  67
  68    The initial encoding can then be changed:
  69
  70    Modify ADDR (REALREG >= 0, ADDR != -1) to indicate that the value
  71    of register REGNUM in the previous frame can be found in memory at
  72    ADDR in this frame (addr_p, !realreg_p, !value_p).
  73
  74    Modify REALREG (REALREG >= 0, ADDR == -1) to indicate that the
  75    value of register REGNUM in the previous frame is found in register
  76    REALREG in this frame (!addr_p, realreg_p, !value_p).
  77
  78    Call trad_frame_set_value (REALREG == -1) to indicate that the
  79    value of register REGNUM in the previous frame is found in ADDR
  80    (!addr_p, !realreg_p, value_p).
  81
  82    Call trad_frame_set_unknown (REALREG == -2) to indicate that the
  83    register's value is not known.  */
  84
  85 struct trad_frame_saved_reg
  86 {
  87   LONGEST addr; /* A CORE_ADDR fits in a longest.  */
  88   int realreg;
  89 };
  90
  91 /* Encode REGNUM value in the trad-frame.  */
  92 void trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[],
  93                            int regnum, LONGEST val);
  94
  95 /* Encode REGNUM is in REALREG in the trad-frame.  */
  96 void trad_frame_set_realreg (struct trad_frame_saved_reg this_saved_regs[],
  97                              int regnum, int realreg);
  98
  99 /* Encode REGNUM is at address ADDR in the trad-frame.  */
 100 void trad_frame_set_addr (struct trad_frame_saved_reg this_trad_cache[],
 101                           int regnum, CORE_ADDR addr);
 102
 103 /* Mark REGNUM as unknown.  */
 104 void trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[],
 105                              int regnum);
 106
 107 /* Convenience functions, return non-zero if the register has been
 108    encoded as specified.  */
 109 int trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[],
 110                         int regnum);
 111 int trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[],
 112                        int regnum);
 113 int trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[],
 114                           int regnum);
 115
 116 /* Reset the save regs cache, setting register values to -1.  */
 117 void trad_frame_reset_saved_regs (struct gdbarch *gdbarch,
 118                                   struct trad_frame_saved_reg *regs);
 119
 120 /* Return a freshly allocated (and initialized) trad_frame array.  */
 121 struct trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct frame_info *);
 122 struct trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct gdbarch *);
 123
 124 /* Given the trad_frame info, return the location of the specified
 125    register.  */
 126 struct value *trad_frame_get_prev_register (struct frame_info *this_frame,
 127                                             struct trad_frame_saved_reg this_saved_regs[],
 128                                             int regnum);
 129
 130 #endif