gdb/regcache.h

   1 /* Cache and manage the values of registers for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2018 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 #include <forward_list>
  25
  26 struct regcache;
  27 struct regset;
  28 struct gdbarch;
  29 struct address_space;
  30
  31 extern struct regcache *get_current_regcache (void);
  32 extern struct regcache *get_thread_regcache (ptid_t ptid);
  33 extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);
  34 extern struct regcache *get_thread_arch_aspace_regcache (ptid_t,
  35                                                          struct gdbarch *,
  36                                                          struct address_space *);
  37
  38 /* Transfer a raw register [0..NUM_REGS) between core-gdb and the
  39    regcache.  The read variants return the status of the register.  */
  40
  41 void regcache_raw_write (struct regcache *regcache, int rawnum,
  42                          const gdb_byte *buf);
  43 extern enum register_status
  44   regcache_raw_read_signed (struct regcache *regcache,
  45                             int regnum, LONGEST *val);
  46
  47 extern void regcache_raw_write_signed (struct regcache *regcache,
  48                                        int regnum, LONGEST val);
  49 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  50                                          int regnum, ULONGEST val);
  51
  52 /* Return the register's value in signed or throw if it's not
  53    available.  */
  54
  55 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  56                                         int regnum);
  57
  58 /* Partial transfer of raw registers.  These perform read, modify,
  59    write style operations.  The read variant returns the status of the
  60    register.  */
  61
  62 extern enum register_status
  63   regcache_raw_read_part (struct regcache *regcache, int regnum,
  64                           int offset, int len, gdb_byte *buf);
  65 void regcache_raw_write_part (struct regcache *regcache, int regnum,
  66                               int offset, int len, const gdb_byte *buf);
  67
  68 void regcache_invalidate (struct regcache *regcache, int regnum);
  69
  70 /* Transfer of pseudo-registers.  The read variants return a register
  71    status, as an indication of when a ``cooked'' register was
  72    constructed from valid, invalid or unavailable ``raw''
  73    registers.  */
  74
  75 /* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
  76 enum register_status regcache_cooked_read (struct regcache *regcache,
  77                                            int rawnum, gdb_byte *buf);
  78 void regcache_cooked_write (struct regcache *regcache, int rawnum,
  79                             const gdb_byte *buf);
  80
  81 /* Read register REGNUM from REGCACHE and return a new value.  This
  82    will call mark_value_bytes_unavailable as appropriate.  */
  83
  84 struct value *regcache_cooked_read_value (struct regcache *regcache,
  85                                           int regnum);
  86
  87 /* Read a register as a signed/unsigned quantity.  */
  88 extern enum register_status
  89   regcache_cooked_read_signed (struct regcache *regcache,
  90                                int regnum, LONGEST *val);
  91 extern enum register_status
  92   regcache_cooked_read_unsigned (struct regcache *regcache,
  93                                  int regnum, ULONGEST *val);
  94 extern void regcache_cooked_write_signed (struct regcache *regcache,
  95                                           int regnum, LONGEST val);
  96 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
  97                                             int regnum, ULONGEST val);
  98
  99 /* Partial transfer of a cooked register.  These perform read, modify,
 100    write style operations.  */
 101
 102 enum register_status regcache_cooked_read_part (struct regcache *regcache,
 103                                                 int regnum, int offset,
 104                                                 int len, gdb_byte *buf);
 105 void regcache_cooked_write_part (struct regcache *regcache, int regnum,
 106                                  int offset, int len, const gdb_byte *buf);
 107
 108 /* Special routines to read/write the PC.  */
 109
 110 /* For regcache_read_pc see common/common-regcache.h.  */
 111 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
 112
 113 /* Transfer a raw register [0..NUM_REGS) between the regcache and the
 114    target.  These functions are called by the target in response to a
 115    target_fetch_registers() or target_store_registers().  */
 116
 117 extern void regcache_raw_supply (struct regcache *regcache,
 118                                  int regnum, const void *buf);
 119 extern void regcache_raw_collect (const struct regcache *regcache,
 120                                   int regnum, void *buf);
 121
 122 /* Mapping between register numbers and offsets in a buffer, for use
 123    in the '*regset' functions below.  In an array of
 124    'regcache_map_entry' each element is interpreted like follows:
 125
 126    - If 'regno' is a register number: Map register 'regno' to the
 127      current offset (starting with 0) and increase the current offset
 128      by 'size' (or the register's size, if 'size' is zero).  Repeat
 129      this with consecutive register numbers up to 'regno+count-1'.
 130
 131    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
 132      offset.
 133
 134    - If count=0: End of the map.  */
 135
 136 struct regcache_map_entry
 137 {
 138   int count;
 139   int regno;
 140   int size;
 141 };
 142
 143 /* Special value for the 'regno' field in the struct above.  */
 144
 145 enum
 146   {
 147     REGCACHE_MAP_SKIP = -1,
 148   };
 149
 150 /* Transfer a set of registers (as described by REGSET) between
 151    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 152    belonging to the regset, otherwise just the register numbered
 153    REGNUM.  The REGSET's 'regmap' field must point to an array of
 154    'struct regcache_map_entry'.
 155
 156    These functions are suitable for the 'regset_supply' and
 157    'regset_collect' fields in a regset structure.  */
 158
 159 extern void regcache_supply_regset (const struct regset *regset,
 160                                     struct regcache *regcache,
 161                                     int regnum, const void *buf,
 162                                     size_t size);
 163 extern void regcache_collect_regset (const struct regset *regset,
 164                                      const struct regcache *regcache,
 165                                      int regnum, void *buf, size_t size);
 166
 167
 168 /* The type of a register.  This function is slightly more efficient
 169    then its gdbarch vector counterpart since it returns a precomputed
 170    value stored in a table.  */
 171
 172 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 173
 174
 175 /* Return the size of register REGNUM.  All registers should have only
 176    one size.  */
 177
 178 extern int register_size (struct gdbarch *gdbarch, int regnum);
 179
 180 typedef enum register_status (regcache_cooked_read_ftype) (void *src,
 181                                                            int regnum,
 182                                                            gdb_byte *buf);
 183
 184 /* A (register_number, register_value) pair.  */
 185
 186 typedef struct cached_reg
 187 {
 188   int num;
 189   gdb_byte *data;
 190 } cached_reg_t;
 191
 192 /* Buffer of registers.  */
 193
 194 class reg_buffer
 195 {
 196 public:
 197   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 198
 199   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 200
 201   /* Return regcache's architecture.  */
 202   gdbarch *arch () const;
 203
 204   /* Get the availability status of the value of register REGNUM in this
 205      buffer.  */
 206   enum register_status get_register_status (int regnum) const;
 207
 208   virtual ~reg_buffer ()
 209   {
 210     xfree (m_registers);
 211     xfree (m_register_status);
 212   }
 213 protected:
 214   /* Assert on the range of REGNUM.  */
 215   void assert_regnum (int regnum) const;
 216
 217   int num_raw_registers () const;
 218
 219   gdb_byte *register_buffer (int regnum) const;
 220
 221   /* Save a register cache.  The set of registers saved into the
 222      regcache determined by the save_reggroup.  COOKED_READ returns
 223      zero iff the register's value can't be returned.  */
 224   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 225
 226   struct regcache_descr *m_descr;
 227
 228   bool m_has_pseudo;
 229   /* The register buffers.  */
 230   gdb_byte *m_registers;
 231   /* Register cache status.  */
 232   signed char *m_register_status;
 233
 234   friend class regcache;
 235   friend class detached_regcache;
 236 };
 237
 238 /* An abstract class which only has methods doing read.  */
 239
 240 class readable_regcache : public reg_buffer
 241 {
 242 public:
 243   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 244     : reg_buffer (gdbarch, has_pseudo)
 245   {}
 246
 247   /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
 248      return its value in *BUF and return its availability status.  */
 249
 250   enum register_status raw_read (int regnum, gdb_byte *buf);
 251   template<typename T, typename = RequireLongest<T>>
 252   enum register_status raw_read (int regnum, T *val);
 253
 254   enum register_status raw_read_part (int regnum, int offset, int len,
 255                                       gdb_byte *buf);
 256
 257   /* Make certain that the register REGNUM is up-to-date.  */
 258   virtual void raw_update (int regnum) = 0;
 259
 260   enum register_status cooked_read (int regnum, gdb_byte *buf);
 261   template<typename T, typename = RequireLongest<T>>
 262   enum register_status cooked_read (int regnum, T *val);
 263
 264   enum register_status cooked_read_part (int regnum, int offset, int len,
 265                                          gdb_byte *buf);
 266
 267   struct value *cooked_read_value (int regnum);
 268
 269 protected:
 270   enum register_status read_part (int regnum, int offset, int len, void *in,
 271                                   bool is_raw);
 272 };
 273
 274 /* Buffer of registers, can be read and written.  */
 275
 276 class detached_regcache : public readable_regcache
 277 {
 278 public:
 279   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 280     : readable_regcache (gdbarch, has_pseudo)
 281   {}
 282
 283   void raw_supply (int regnum, const void *buf);
 284
 285   void raw_supply (int regnum, const reg_buffer &src)
 286   {
 287     raw_supply (regnum, src.register_buffer (regnum));
 288   }
 289
 290   void raw_update (int regnum) override
 291   {}
 292
 293   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 294                            bool is_signed);
 295
 296   void raw_supply_zeroed (int regnum);
 297
 298   void invalidate (int regnum);
 299
 300   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 301 };
 302
 303 class readonly_detached_regcache;
 304
 305 /* The register cache for storing raw register values.  */
 306
 307 class regcache : public detached_regcache
 308 {
 309 public:
 310   DISABLE_COPY_AND_ASSIGN (regcache);
 311
 312   /* Return REGCACHE's address space.  */
 313   const address_space *aspace () const
 314   {
 315     return m_aspace;
 316   }
 317
 318   /* Restore 'this' regcache.  The set of registers restored into
 319      the regcache determined by the restore_reggroup.
 320      Writes to regcache will go through to the target.  SRC is a
 321      read-only register cache.  */
 322   void restore (readonly_detached_regcache *src);
 323
 324   void cooked_write (int regnum, const gdb_byte *buf);
 325
 326   void raw_write (int regnum, const gdb_byte *buf);
 327
 328   template<typename T, typename = RequireLongest<T>>
 329   void raw_write (int regnum, T val);
 330
 331   template<typename T, typename = RequireLongest<T>>
 332   void cooked_write (int regnum, T val);
 333
 334   void raw_update (int regnum) override;
 335
 336   void raw_collect (int regnum, void *buf) const;
 337
 338   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 339                             bool is_signed) const;
 340
 341   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 342
 343   void cooked_write_part (int regnum, int offset, int len,
 344                           const gdb_byte *buf);
 345
 346   void supply_regset (const struct regset *regset,
 347                       int regnum, const void *buf, size_t size);
 348
 349
 350   void collect_regset (const struct regset *regset, int regnum,
 351                        void *buf, size_t size) const;
 352
 353   /* Return REGCACHE's ptid.  */
 354
 355   ptid_t ptid () const
 356   {
 357     gdb_assert (m_ptid != minus_one_ptid);
 358
 359     return m_ptid;
 360   }
 361
 362   void set_ptid (const ptid_t ptid)
 363   {
 364     this->m_ptid = ptid;
 365   }
 366
 367 /* Dump the contents of a register from the register cache to the target
 368    debug.  */
 369   void debug_print_register (const char *func, int regno);
 370
 371   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 372 protected:
 373   regcache (gdbarch *gdbarch, const address_space *aspace_);
 374   static std::forward_list<regcache *> current_regcache;
 375
 376 private:
 377
 378   void transfer_regset (const struct regset *regset,
 379                         struct regcache *out_regcache,
 380                         int regnum, const void *in_buf,
 381                         void *out_buf, size_t size) const;
 382
 383   enum register_status write_part (int regnum, int offset, int len,
 384                                    const void *out, bool is_raw);
 385
 386
 387   /* The address space of this register cache (for registers where it
 388      makes sense, like PC or SP).  */
 389   const address_space * const m_aspace;
 390
 391   /* If this is a read-write cache, which thread's registers is
 392      it connected to?  */
 393   ptid_t m_ptid;
 394
 395   friend struct regcache *
 396   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 397                                    struct address_space *aspace);
 398
 399   friend void
 400   registers_changed_ptid (ptid_t ptid);
 401 };
 402
 403 class readonly_detached_regcache : public readable_regcache
 404 {
 405 public:
 406   readonly_detached_regcache (const regcache &src);
 407
 408   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 409
 410   readonly_detached_regcache (gdbarch *gdbarch,
 411                               regcache_cooked_read_ftype *cooked_read,
 412                               void *src)
 413     : readable_regcache (gdbarch, true)
 414   {
 415     save (cooked_read, src);
 416   }
 417
 418   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 419
 420   void raw_update (int regnum) override
 421   {}
 422 };
 423
 424 extern void registers_changed (void);
 425 extern void registers_changed_ptid (ptid_t);
 426
 427 /* An abstract base class for register dump.  */
 428
 429 class register_dump
 430 {
 431 public:
 432   void dump (ui_file *file);
 433   virtual ~register_dump () = default;
 434
 435 protected:
 436   register_dump (gdbarch *arch)
 437     : m_gdbarch (arch)
 438   {}
 439
 440   /* Dump the register REGNUM contents.  If REGNUM is -1, print the
 441      header.  */
 442   virtual void dump_reg (ui_file *file, int regnum) = 0;
 443
 444   gdbarch *m_gdbarch;
 445 };
 446
 447 #endif /* REGCACHE_H */