gdbsupport/common-regcache.h

   1 /* Cache and manage the values of registers
   2
   3    Copyright (C) 2014-2024 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 GDBSUPPORT_COMMON_REGCACHE_H
  21 #define GDBSUPPORT_COMMON_REGCACHE_H
  22
  23 struct reg_buffer_common;
  24
  25 /* This header is a stopgap until we have an independent regcache.  */
  26
  27 enum register_status : signed char
  28   {
  29     /* The register value is not in the cache, and we don't know yet
  30        whether it's available in the target (or traceframe).  */
  31     REG_UNKNOWN = 0,
  32
  33     /* The register value is valid and cached.  */
  34     REG_VALID = 1,
  35
  36     /* The register value is unavailable.  E.g., we're inspecting a
  37        traceframe, and this register wasn't collected.  Note that this
  38        "unavailable" is different from saying the register does not
  39        exist in the target's architecture --- in that case, the target
  40        should have given us a target description that does not include
  41        the register in the first place.  */
  42     REG_UNAVAILABLE = -1
  43   };
  44
  45 /* Return a pointer to the register cache associated with the
  46    thread specified by PTID.  This function must be provided by
  47    the client.  */
  48
  49 extern reg_buffer_common *get_thread_regcache_for_ptid (ptid_t ptid);
  50
  51 /* Read the PC register.  This function must be provided by the
  52    client.  */
  53
  54 extern CORE_ADDR regcache_read_pc (reg_buffer_common *regcache);
  55
  56 /* Read the PC register.  If PC cannot be read, return 0.
  57    This is a wrapper around 'regcache_read_pc'.  */
  58
  59 extern CORE_ADDR regcache_read_pc_protected (reg_buffer_common *regcache);
  60
  61 /* Read a raw register into a unsigned integer.  */
  62 extern enum register_status
  63 regcache_raw_read_unsigned (reg_buffer_common *regcache, int regnum,
  64                             ULONGEST *val);
  65
  66 ULONGEST regcache_raw_get_unsigned (reg_buffer_common *regcache, int regnum);
  67
  68 struct reg_buffer_common
  69 {
  70   virtual ~reg_buffer_common () = default;
  71
  72   /* Get the availability status of the value of register REGNUM in this
  73      buffer.  */
  74   virtual register_status get_register_status (int regnum) const = 0;
  75
  76   /* Return the size of register numbered REGNUM in this buffer.  */
  77   virtual int register_size (int regnum) const = 0;
  78
  79   /* Supply register REGNUM, whose contents are stored in SRC, to this register
  80      buffer.  */
  81   virtual void raw_supply (int regnum, gdb::array_view<const gdb_byte> src)
  82     = 0;
  83
  84   void raw_supply (int regnum, const uint64_t *src)
  85   {
  86     raw_supply (regnum,
  87                 gdb::make_array_view ((const gdb_byte *) src, sizeof (*src)));
  88   }
  89
  90   void raw_supply (int regnum, const gdb_byte *src)
  91   { raw_supply (regnum, gdb::make_array_view (src, register_size (regnum))); }
  92
  93   /* Supply part of register REGNUM with zeroed value.  Start at OFFSET in
  94      the register, with size SIZE.  The rest of the register is left
  95      untouched.  */
  96   virtual void raw_supply_part_zeroed (int regnum, int offset, size_t size)
  97     = 0;
  98
  99   /* Collect register REGNUM from this register buffer and store its contents in
 100      DST.  */
 101   virtual void raw_collect (int regnum, gdb::array_view<gdb_byte> dst) const
 102     = 0;
 103
 104   void raw_collect (int regnum, uint64_t *dst) const
 105   {
 106     raw_collect (regnum,
 107                  gdb::make_array_view ((gdb_byte *) dst, sizeof (*dst)));
 108   };
 109
 110   void raw_collect (int regnum, gdb_byte *dst)
 111   { raw_collect (regnum, gdb::make_array_view (dst, register_size (regnum))); }
 112
 113   /* Compare the contents of the register stored in the regcache (ignoring the
 114      first OFFSET bytes) to the contents of BUF (without any offset).  Returns
 115      true if the same.  */
 116   virtual bool raw_compare (int regnum, const void *buf, int offset) const = 0;
 117 };
 118
 119 #endif /* GDBSUPPORT_COMMON_REGCACHE_H */