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,
  59                                      gdb::array_view<const gdb_byte> bytes);
  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 /* Describes the kind of encoding a stored register has.  */
  66 enum class trad_frame_saved_reg_kind
  67 {
  68   /* Register value is unknown.  */
  69   UNKNOWN = 0,
  70   /* Register value is a constant.  */
  71   VALUE,
  72   /* Register value is in another register.  */
  73   REALREG,
  74   /* Register value is at an address.  */
  75   ADDR,
  76   /* Register value is a sequence of bytes.  */
  77   VALUE_BYTES
  78 };
  79
  80 /* A struct that describes a saved register in a frame.  */
  81
  82 struct trad_frame_saved_reg
  83 {
  84   /* Setters */
  85
  86   /* Encode that the saved register's value is constant VAL in the
  87      trad-frame.  */
  88   void set_value (LONGEST val)
  89   {
  90     m_kind = trad_frame_saved_reg_kind::VALUE;
  91     m_reg.value = val;
  92   }
  93
  94   /* Encode that the saved register's value is stored in register REALREG.  */
  95   void set_realreg (int realreg)
  96   {
  97     m_kind = trad_frame_saved_reg_kind::REALREG;
  98     m_reg.realreg = realreg;
  99   }
 100
 101   /* Encode that the saved register's value is stored in memory at ADDR.  */
 102   void set_addr (LONGEST addr)
 103   {
 104     m_kind = trad_frame_saved_reg_kind::ADDR;
 105     m_reg.addr = addr;
 106   }
 107
 108   /* Encode that the saved register's value is unknown.  */
 109   void set_unknown ()
 110   {
 111     m_kind = trad_frame_saved_reg_kind::UNKNOWN;
 112   }
 113
 114   /* Encode that the saved register's value is stored as a sequence of bytes.
 115      This is useful when the value is larger than what primitive types
 116      can hold.  */
 117   void set_value_bytes (gdb::array_view<const gdb_byte> bytes)
 118   {
 119     /* Allocate the space and copy the data bytes.  */
 120     gdb_byte *data = FRAME_OBSTACK_CALLOC (bytes.size (), gdb_byte);
 121     memcpy (data, bytes.data (), bytes.size ());
 122
 123     m_kind = trad_frame_saved_reg_kind::VALUE_BYTES;
 124     m_reg.value_bytes = data;
 125   }
 126
 127   /* Getters */
 128
 129   LONGEST value () const
 130   {
 131     gdb_assert (m_kind == trad_frame_saved_reg_kind::VALUE);
 132     return m_reg.value;
 133   }
 134
 135   int realreg () const
 136   {
 137     gdb_assert (m_kind == trad_frame_saved_reg_kind::REALREG);
 138     return m_reg.realreg;
 139   }
 140
 141   LONGEST addr () const
 142   {
 143     gdb_assert (m_kind == trad_frame_saved_reg_kind::ADDR);
 144     return m_reg.addr;
 145   }
 146
 147   const gdb_byte *value_bytes () const
 148   {
 149     gdb_assert (m_kind == trad_frame_saved_reg_kind::VALUE_BYTES);
 150     return m_reg.value_bytes;
 151   }
 152
 153   /* Convenience functions, return true if the register has been
 154      encoded as specified.  Return false otherwise.  */
 155   bool is_value () const
 156   {
 157     return m_kind == trad_frame_saved_reg_kind::VALUE;
 158   }
 159
 160   bool is_realreg () const
 161   {
 162     return m_kind == trad_frame_saved_reg_kind::REALREG;
 163   }
 164
 165   bool is_addr () const
 166   {
 167     return m_kind == trad_frame_saved_reg_kind::ADDR;
 168   }
 169
 170   bool is_unknown () const
 171   {
 172     return m_kind == trad_frame_saved_reg_kind::UNKNOWN;
 173   }
 174
 175   bool is_value_bytes () const
 176   {
 177     return m_kind == trad_frame_saved_reg_kind::VALUE_BYTES;
 178   }
 179
 180 private:
 181
 182   trad_frame_saved_reg_kind m_kind;
 183
 184   union {
 185     LONGEST value;
 186     int realreg;
 187     LONGEST addr;
 188     const gdb_byte *value_bytes;
 189   } m_reg;
 190 };
 191
 192 /* Reset the saved regs cache, setting register values to REALREG.  */
 193 void trad_frame_reset_saved_regs (struct gdbarch *gdbarch,
 194                                   trad_frame_saved_reg *regs);
 195
 196 /* Return a freshly allocated (and initialized) trad_frame array.  */
 197 trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct frame_info *);
 198 trad_frame_saved_reg *trad_frame_alloc_saved_regs (struct gdbarch *);
 199
 200 /* Given the trad_frame info, return the location of the specified
 201    register.  */
 202 struct value *trad_frame_get_prev_register (struct frame_info *this_frame,
 203                                             trad_frame_saved_reg this_saved_regs[],
 204                                             int regnum);
 205
 206 #endif