gdb/trad-frame.h

   1 /* Traditional frame unwind support, for GDB the GNU Debugger.
   2
   3    Copyright (C) 2003-2021 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 /* Given the cache in THIS_TRAD_CACHE, set the value of REGNUM to the bytes
  56    contained in BYTES with size SIZE.  */
  57 void trad_frame_set_reg_value_bytes (struct trad_frame_cache *this_trad_cache,
  58                                      int regnum, const gdb_byte *bytes,
  59                                      size_t size);
  60
  61 struct value *trad_frame_get_register (struct trad_frame_cache *this_trad_cache,
  62                                        struct frame_info *this_frame,
  63                                        int regnum);
  64
  65 /* A traditional saved regs table, indexed by REGNUM, encoding where
  66    the value of REGNUM for the previous frame can be found in this
  67    frame.
  68
  69    The table is initialized with an identity encoding (ADDR == -1,
  70    REALREG == REGNUM) indicating that the value of REGNUM in the
  71    previous frame can be found in register REGNUM (== REALREG) in this
  72    frame.
  73
  74    The initial encoding can then be changed:
  75
  76    Modify ADDR (REALREG >= 0, ADDR != -1) to indicate that the value
  77    of register REGNUM in the previous frame can be found in memory at
  78    ADDR in this frame (addr_p, !realreg_p, !value_p).
  79
  80    Modify REALREG (REALREG >= 0, ADDR == -1) to indicate that the
  81    value of register REGNUM in the previous frame is found in register
  82    REALREG in this frame (!addr_p, realreg_p, !value_p).
  83
  84    Call trad_frame_set_value (REALREG == -1) to indicate that the
  85    value of register REGNUM in the previous frame is found in ADDR
  86    (!addr_p, !realreg_p, value_p).
  87
  88    Call trad_frame_set_unknown (REALREG == -2) to indicate that the
  89    register's value is not known.  */
  90
  91 struct trad_frame_saved_reg
  92 {
  93   LONGEST addr; /* A CORE_ADDR fits in a longest.  */
  94   int realreg;
  95   /* Register data (for values that don't fit in ADDR).  */
  96   gdb_byte *data;
  97 };
  98
  99 /* Encode REGNUM value in the trad-frame.  */
 100 void trad_frame_set_value (struct trad_frame_saved_reg this_saved_regs[],
 101                            int regnum, LONGEST val);
 102
 103 /* Encode REGNUM is in REALREG in the trad-frame.  */
 104 void trad_frame_set_realreg (struct trad_frame_saved_reg this_saved_regs[],
 105                              int regnum, int realreg);
 106
 107 /* Encode REGNUM is at address ADDR in the trad-frame.  */
 108 void trad_frame_set_addr (struct trad_frame_saved_reg this_trad_cache[],
 109                           int regnum, CORE_ADDR addr);
 110
 111 /* Mark REGNUM as unknown.  */
 112 void trad_frame_set_unknown (struct trad_frame_saved_reg this_saved_regs[],
 113                              int regnum);
 114
 115 /* Encode REGNUM value in the trad-frame as a sequence of bytes.  This is
 116    useful when the value is larger than what primitive types can hold.  */
 117 void trad_frame_set_value_bytes (struct trad_frame_saved_reg this_saved_regs[],
 118                                  int regnum, const gdb_byte *bytes,
 119                                  size_t size);
 120
 121 /* Convenience functions, return non-zero if the register has been
 122    encoded as specified.  */
 123 int trad_frame_value_p (struct trad_frame_saved_reg this_saved_regs[],
 124                         int regnum);
 125 int trad_frame_addr_p (struct trad_frame_saved_reg this_saved_regs[],
 126                        int regnum);
 127 int trad_frame_realreg_p (struct trad_frame_saved_reg this_saved_regs[],
 128                           int regnum);
 129
 130 /* Return TRUE if REGNUM is stored as a sequence of bytes, and FALSE
 131    otherwise.  */
 132 bool trad_frame_value_bytes_p (struct trad_frame_saved_reg this_saved_regs[],
 133                               int regnum);
 134
 135 /* Reset the save regs cache, setting register values to -1.  */
 136 void trad_frame_reset_saved_regs (struct gdbarch *gdbarch,
 137                                   struct trad_frame_saved_reg *regs);
 138
 139 /* Return a freshly allocated (and initialized) trad_frame array.  */
 140 struct trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct frame_info *);
 141 struct trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct gdbarch *);
 142
 143 /* Given the trad_frame info, return the location of the specified
 144    register.  */
 145 struct value *trad_frame_get_prev_register (struct frame_info *this_frame,
 146                                             struct trad_frame_saved_reg this_saved_regs[],
 147                                             int regnum);
 148
 149 #endif