gdb/regcache.h

   1 /* Cache and manage the values of registers for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2017 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 REGCACHE_H
  21 #define REGCACHE_H
  22
  23 #include "common-regcache.h"
  24
  25 struct regcache;
  26 struct regset;
  27 struct gdbarch;
  28 struct address_space;
  29
  30 extern struct regcache *get_current_regcache (void);
  31 extern struct regcache *get_thread_regcache (ptid_t ptid);
  32 extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);
  33 extern struct regcache *get_thread_arch_aspace_regcache (ptid_t,
  34                                                          struct gdbarch *,
  35                                                          struct address_space *);
  36
  37 void regcache_xfree (struct regcache *regcache);
  38 struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
  39 struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
  40                                    struct address_space *aspace);
  41
  42 /* Return REGCACHE's ptid.  */
  43
  44 extern ptid_t regcache_get_ptid (const struct regcache *regcache);
  45
  46 /* Return REGCACHE's architecture.  */
  47
  48 extern struct gdbarch *get_regcache_arch (const struct regcache *regcache);
  49
  50 /* Return REGCACHE's address space.  */
  51
  52 extern struct address_space *get_regcache_aspace (const struct regcache *);
  53
  54 enum register_status regcache_register_status (const struct regcache *regcache,
  55                                                int regnum);
  56
  57 /* Make certain that the register REGNUM in REGCACHE is up-to-date.  */
  58
  59 void regcache_raw_update (struct regcache *regcache, int regnum);
  60
  61 /* Transfer a raw register [0..NUM_REGS) between core-gdb and the
  62    regcache.  The read variants return the status of the register.  */
  63
  64 enum register_status regcache_raw_read (struct regcache *regcache,
  65                                         int rawnum, gdb_byte *buf);
  66 void regcache_raw_write (struct regcache *regcache, int rawnum,
  67                          const gdb_byte *buf);
  68 extern enum register_status
  69   regcache_raw_read_signed (struct regcache *regcache,
  70                             int regnum, LONGEST *val);
  71
  72 extern void regcache_raw_write_signed (struct regcache *regcache,
  73                                        int regnum, LONGEST val);
  74 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  75                                          int regnum, ULONGEST val);
  76
  77 /* Return the register's value in signed or throw if it's not
  78    available.  */
  79
  80 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  81                                         int regnum);
  82
  83 /* Set a raw register's value in the regcache's buffer.  Unlike
  84    regcache_raw_write, this is not write-through.  The intention is
  85    allowing to change the buffer contents of a read-only regcache
  86    allocated with regcache_xmalloc.  */
  87
  88 extern void regcache_raw_set_cached_value
  89   (struct regcache *regcache, int regnum, const gdb_byte *buf);
  90
  91 /* Partial transfer of raw registers.  These perform read, modify,
  92    write style operations.  The read variant returns the status of the
  93    register.  */
  94
  95 extern enum register_status
  96   regcache_raw_read_part (struct regcache *regcache, int regnum,
  97                           int offset, int len, gdb_byte *buf);
  98 void regcache_raw_write_part (struct regcache *regcache, int regnum,
  99                               int offset, int len, const gdb_byte *buf);
 100
 101 void regcache_invalidate (struct regcache *regcache, int regnum);
 102
 103 /* Transfer of pseudo-registers.  The read variants return a register
 104    status, as an indication of when a ``cooked'' register was
 105    constructed from valid, invalid or unavailable ``raw''
 106    registers.  */
 107
 108 /* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
 109 enum register_status regcache_cooked_read (struct regcache *regcache,
 110                                            int rawnum, gdb_byte *buf);
 111 void regcache_cooked_write (struct regcache *regcache, int rawnum,
 112                             const gdb_byte *buf);
 113
 114 /* Read register REGNUM from REGCACHE and return a new value.  This
 115    will call mark_value_bytes_unavailable as appropriate.  */
 116
 117 struct value *regcache_cooked_read_value (struct regcache *regcache,
 118                                           int regnum);
 119
 120 /* Read a register as a signed/unsigned quantity.  */
 121 extern enum register_status
 122   regcache_cooked_read_signed (struct regcache *regcache,
 123                                int regnum, LONGEST *val);
 124 extern enum register_status
 125   regcache_cooked_read_unsigned (struct regcache *regcache,
 126                                  int regnum, ULONGEST *val);
 127 extern void regcache_cooked_write_signed (struct regcache *regcache,
 128                                           int regnum, LONGEST val);
 129 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
 130                                             int regnum, ULONGEST val);
 131
 132 /* Partial transfer of a cooked register.  These perform read, modify,
 133    write style operations.  */
 134
 135 enum register_status regcache_cooked_read_part (struct regcache *regcache,
 136                                                 int regnum, int offset,
 137                                                 int len, gdb_byte *buf);
 138 void regcache_cooked_write_part (struct regcache *regcache, int regnum,
 139                                  int offset, int len, const gdb_byte *buf);
 140
 141 /* Special routines to read/write the PC.  */
 142
 143 /* For regcache_read_pc see common/common-regcache.h.  */
 144 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
 145
 146 /* Transfer a raw register [0..NUM_REGS) between the regcache and the
 147    target.  These functions are called by the target in response to a
 148    target_fetch_registers() or target_store_registers().  */
 149
 150 extern void regcache_raw_supply (struct regcache *regcache,
 151                                  int regnum, const void *buf);
 152 extern void regcache_raw_collect (const struct regcache *regcache,
 153                                   int regnum, void *buf);
 154
 155 /* Mapping between register numbers and offsets in a buffer, for use
 156    in the '*regset' functions below.  In an array of
 157    'regcache_map_entry' each element is interpreted like follows:
 158
 159    - If 'regno' is a register number: Map register 'regno' to the
 160      current offset (starting with 0) and increase the current offset
 161      by 'size' (or the register's size, if 'size' is zero).  Repeat
 162      this with consecutive register numbers up to 'regno+count-1'.
 163
 164    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
 165      offset.
 166
 167    - If count=0: End of the map.  */
 168
 169 struct regcache_map_entry
 170 {
 171   int count;
 172   int regno;
 173   int size;
 174 };
 175
 176 /* Special value for the 'regno' field in the struct above.  */
 177
 178 enum
 179   {
 180     REGCACHE_MAP_SKIP = -1,
 181   };
 182
 183 /* Transfer a set of registers (as described by REGSET) between
 184    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 185    belonging to the regset, otherwise just the register numbered
 186    REGNUM.  The REGSET's 'regmap' field must point to an array of
 187    'struct regcache_map_entry'.
 188
 189    These functions are suitable for the 'regset_supply' and
 190    'regset_collect' fields in a regset structure.  */
 191
 192 extern void regcache_supply_regset (const struct regset *regset,
 193                                     struct regcache *regcache,
 194                                     int regnum, const void *buf,
 195                                     size_t size);
 196 extern void regcache_collect_regset (const struct regset *regset,
 197                                      const struct regcache *regcache,
 198                                      int regnum, void *buf, size_t size);
 199
 200
 201 /* The type of a register.  This function is slightly more efficient
 202    then its gdbarch vector counterpart since it returns a precomputed
 203    value stored in a table.  */
 204
 205 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 206
 207
 208 /* Return the size of register REGNUM.  All registers should have only
 209    one size.  */
 210
 211 extern int register_size (struct gdbarch *gdbarch, int regnum);
 212
 213
 214 /* Save/restore a register cache.  The set of registers saved /
 215    restored into the DST regcache determined by the save_reggroup /
 216    restore_reggroup respectively.  COOKED_READ returns zero iff the
 217    register's value can't be returned.  */
 218
 219 typedef enum register_status (regcache_cooked_read_ftype) (void *src,
 220                                                            int regnum,
 221                                                            gdb_byte *buf);
 222
 223 extern void regcache_save (struct regcache *dst,
 224                            regcache_cooked_read_ftype *cooked_read,
 225                            void *cooked_read_context);
 226
 227 enum regcache_dump_what
 228 {
 229   regcache_dump_none, regcache_dump_raw,
 230   regcache_dump_cooked, regcache_dump_groups,
 231   regcache_dump_remote
 232 };
 233
 234 /* The register cache for storing raw register values.  */
 235
 236 class regcache
 237 {
 238 public:
 239   regcache (gdbarch *gdbarch, address_space *aspace_)
 240     : regcache (gdbarch, aspace_, true)
 241   {}
 242
 243   struct readonly_t {};
 244   static constexpr readonly_t readonly {};
 245
 246   /* Create a readonly regcache from a non-readonly regcache.  */
 247   regcache (readonly_t, const regcache &src);
 248
 249   regcache (const regcache &) = delete;
 250   void operator= (const regcache &) = delete;
 251
 252   ~regcache ()
 253   {
 254     xfree (m_registers);
 255     xfree (m_register_status);
 256   }
 257
 258   gdbarch *arch () const;
 259
 260   address_space *aspace () const
 261   {
 262     return m_aspace;
 263   }
 264
 265   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 266
 267   enum register_status cooked_read (int regnum, gdb_byte *buf);
 268   void cooked_write (int regnum, const gdb_byte *buf);
 269
 270   enum register_status raw_read (int regnum, gdb_byte *buf);
 271   void raw_write (int regnum, const gdb_byte *buf);
 272
 273   enum register_status raw_read_signed (int regnum, LONGEST *val);
 274
 275   void raw_write_signed (int regnum, LONGEST val);
 276
 277   enum register_status raw_read_unsigned (int regnum, ULONGEST *val);
 278
 279   void raw_write_unsigned (int regnum, ULONGEST val);
 280
 281   struct value *cooked_read_value (int regnum);
 282
 283   enum register_status cooked_read_signed (int regnum, LONGEST *val);
 284
 285   void cooked_write_signed (int regnum, LONGEST val);
 286
 287   enum register_status cooked_read_unsigned (int regnum, ULONGEST *val);
 288
 289   void cooked_write_unsigned (int regnum, ULONGEST val);
 290
 291   void raw_update (int regnum);
 292
 293   void raw_collect (int regnum, void *buf) const;
 294
 295   void raw_supply (int regnum, const void *buf);
 296
 297   void raw_supply_zeroed (int regnum);
 298
 299   enum register_status get_register_status (int regnum) const;
 300
 301   void raw_set_cached_value (int regnum, const gdb_byte *buf);
 302
 303   void invalidate (int regnum);
 304
 305   enum register_status raw_read_part (int regnum, int offset, int len,
 306                                       gdb_byte *buf);
 307
 308   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 309
 310   enum register_status cooked_read_part (int regnum, int offset, int len,
 311                                          gdb_byte *buf);
 312
 313   void cooked_write_part (int regnum, int offset, int len,
 314                           const gdb_byte *buf);
 315
 316   void supply_regset (const struct regset *regset,
 317                       int regnum, const void *buf, size_t size);
 318
 319
 320   void collect_regset (const struct regset *regset, int regnum,
 321                        void *buf, size_t size) const;
 322
 323   void dump (ui_file *file, enum regcache_dump_what what_to_dump);
 324
 325   ptid_t ptid () const
 326   {
 327     return m_ptid;
 328   }
 329
 330   void set_ptid (const ptid_t ptid)
 331   {
 332     this->m_ptid = ptid;
 333   }
 334
 335 /* Dump the contents of a register from the register cache to the target
 336    debug.  */
 337   void debug_print_register (const char *func, int regno);
 338
 339 private:
 340   regcache (gdbarch *gdbarch, address_space *aspace_, bool readonly_p_);
 341
 342   gdb_byte *register_buffer (int regnum) const;
 343
 344   void restore (struct regcache *src);
 345
 346   void cpy_no_passthrough (struct regcache *src);
 347
 348   enum register_status xfer_part (int regnum, int offset, int len, void *in,
 349                                   const void *out,
 350                                   decltype (regcache_raw_read) read,
 351                                   decltype (regcache_raw_write) write);
 352
 353   void transfer_regset (const struct regset *regset,
 354                         struct regcache *out_regcache,
 355                         int regnum, const void *in_buf,
 356                         void *out_buf, size_t size) const;
 357
 358   struct regcache_descr *m_descr;
 359
 360   /* The address space of this register cache (for registers where it
 361      makes sense, like PC or SP).  */
 362   struct address_space *m_aspace;
 363
 364   /* The register buffers.  A read-only register cache can hold the
 365      full [0 .. gdbarch_num_regs + gdbarch_num_pseudo_regs) while a read/write
 366      register cache can only hold [0 .. gdbarch_num_regs).  */
 367   gdb_byte *m_registers;
 368   /* Register cache status.  */
 369   signed char *m_register_status;
 370   /* Is this a read-only cache?  A read-only cache is used for saving
 371      the target's register state (e.g, across an inferior function
 372      call or just before forcing a function return).  A read-only
 373      cache can only be updated via the methods regcache_dup() and
 374      regcache_cpy().  The actual contents are determined by the
 375      reggroup_save and reggroup_restore methods.  */
 376   bool m_readonly_p;
 377   /* If this is a read-write cache, which thread's registers is
 378      it connected to?  */
 379   ptid_t m_ptid;
 380
 381   friend struct regcache *
 382   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 383                                    struct address_space *aspace);
 384
 385   friend void
 386   regcache_cpy (struct regcache *dst, struct regcache *src);
 387 };
 388
 389 /* Copy/duplicate the contents of a register cache.  By default, the
 390    operation is pass-through.  Writes to DST and reads from SRC will
 391    go through to the target.  See also regcache_cpy_no_passthrough.
 392
 393    regcache_cpy can not have overlapping SRC and DST buffers.  */
 394
 395 extern struct regcache *regcache_dup (struct regcache *regcache);
 396 extern void regcache_cpy (struct regcache *dest, struct regcache *src);
 397
 398 extern void registers_changed (void);
 399 extern void registers_changed_ptid (ptid_t);
 400
 401 #endif /* REGCACHE_H */