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 /* Return REGCACHE's ptid.  */
  39
  40 extern ptid_t regcache_get_ptid (const struct regcache *regcache);
  41
  42 enum register_status regcache_register_status (const struct regcache *regcache,
  43                                                int regnum);
  44
  45 /* Make certain that the register REGNUM in REGCACHE is up-to-date.  */
  46
  47 void regcache_raw_update (struct regcache *regcache, int regnum);
  48
  49 /* Transfer a raw register [0..NUM_REGS) between core-gdb and the
  50    regcache.  The read variants return the status of the register.  */
  51
  52 enum register_status regcache_raw_read (struct regcache *regcache,
  53                                         int rawnum, gdb_byte *buf);
  54 void regcache_raw_write (struct regcache *regcache, int rawnum,
  55                          const gdb_byte *buf);
  56 extern enum register_status
  57   regcache_raw_read_signed (struct regcache *regcache,
  58                             int regnum, LONGEST *val);
  59
  60 extern void regcache_raw_write_signed (struct regcache *regcache,
  61                                        int regnum, LONGEST val);
  62 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  63                                          int regnum, ULONGEST val);
  64
  65 /* Return the register's value in signed or throw if it's not
  66    available.  */
  67
  68 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  69                                         int regnum);
  70
  71 /* Partial transfer of raw registers.  These perform read, modify,
  72    write style operations.  The read variant returns the status of the
  73    register.  */
  74
  75 extern enum register_status
  76   regcache_raw_read_part (struct regcache *regcache, int regnum,
  77                           int offset, int len, gdb_byte *buf);
  78 void regcache_raw_write_part (struct regcache *regcache, int regnum,
  79                               int offset, int len, const gdb_byte *buf);
  80
  81 void regcache_invalidate (struct regcache *regcache, int regnum);
  82
  83 /* Transfer of pseudo-registers.  The read variants return a register
  84    status, as an indication of when a ``cooked'' register was
  85    constructed from valid, invalid or unavailable ``raw''
  86    registers.  */
  87
  88 /* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
  89 enum register_status regcache_cooked_read (struct regcache *regcache,
  90                                            int rawnum, gdb_byte *buf);
  91 void regcache_cooked_write (struct regcache *regcache, int rawnum,
  92                             const gdb_byte *buf);
  93
  94 /* Read register REGNUM from REGCACHE and return a new value.  This
  95    will call mark_value_bytes_unavailable as appropriate.  */
  96
  97 struct value *regcache_cooked_read_value (struct regcache *regcache,
  98                                           int regnum);
  99
 100 /* Read a register as a signed/unsigned quantity.  */
 101 extern enum register_status
 102   regcache_cooked_read_signed (struct regcache *regcache,
 103                                int regnum, LONGEST *val);
 104 extern enum register_status
 105   regcache_cooked_read_unsigned (struct regcache *regcache,
 106                                  int regnum, ULONGEST *val);
 107 extern void regcache_cooked_write_signed (struct regcache *regcache,
 108                                           int regnum, LONGEST val);
 109 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
 110                                             int regnum, ULONGEST val);
 111
 112 /* Partial transfer of a cooked register.  These perform read, modify,
 113    write style operations.  */
 114
 115 enum register_status regcache_cooked_read_part (struct regcache *regcache,
 116                                                 int regnum, int offset,
 117                                                 int len, gdb_byte *buf);
 118 void regcache_cooked_write_part (struct regcache *regcache, int regnum,
 119                                  int offset, int len, const gdb_byte *buf);
 120
 121 /* Special routines to read/write the PC.  */
 122
 123 /* For regcache_read_pc see common/common-regcache.h.  */
 124 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
 125
 126 /* Transfer a raw register [0..NUM_REGS) between the regcache and the
 127    target.  These functions are called by the target in response to a
 128    target_fetch_registers() or target_store_registers().  */
 129
 130 extern void regcache_raw_supply (struct regcache *regcache,
 131                                  int regnum, const void *buf);
 132 extern void regcache_raw_collect (const struct regcache *regcache,
 133                                   int regnum, void *buf);
 134
 135 /* Mapping between register numbers and offsets in a buffer, for use
 136    in the '*regset' functions below.  In an array of
 137    'regcache_map_entry' each element is interpreted like follows:
 138
 139    - If 'regno' is a register number: Map register 'regno' to the
 140      current offset (starting with 0) and increase the current offset
 141      by 'size' (or the register's size, if 'size' is zero).  Repeat
 142      this with consecutive register numbers up to 'regno+count-1'.
 143
 144    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
 145      offset.
 146
 147    - If count=0: End of the map.  */
 148
 149 struct regcache_map_entry
 150 {
 151   int count;
 152   int regno;
 153   int size;
 154 };
 155
 156 /* Special value for the 'regno' field in the struct above.  */
 157
 158 enum
 159   {
 160     REGCACHE_MAP_SKIP = -1,
 161   };
 162
 163 /* Transfer a set of registers (as described by REGSET) between
 164    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 165    belonging to the regset, otherwise just the register numbered
 166    REGNUM.  The REGSET's 'regmap' field must point to an array of
 167    'struct regcache_map_entry'.
 168
 169    These functions are suitable for the 'regset_supply' and
 170    'regset_collect' fields in a regset structure.  */
 171
 172 extern void regcache_supply_regset (const struct regset *regset,
 173                                     struct regcache *regcache,
 174                                     int regnum, const void *buf,
 175                                     size_t size);
 176 extern void regcache_collect_regset (const struct regset *regset,
 177                                      const struct regcache *regcache,
 178                                      int regnum, void *buf, size_t size);
 179
 180
 181 /* The type of a register.  This function is slightly more efficient
 182    then its gdbarch vector counterpart since it returns a precomputed
 183    value stored in a table.  */
 184
 185 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 186
 187
 188 /* Return the size of register REGNUM.  All registers should have only
 189    one size.  */
 190
 191 extern int register_size (struct gdbarch *gdbarch, int regnum);
 192
 193 typedef enum register_status (regcache_cooked_read_ftype) (void *src,
 194                                                            int regnum,
 195                                                            gdb_byte *buf);
 196
 197 enum regcache_dump_what
 198 {
 199   regcache_dump_none, regcache_dump_raw,
 200   regcache_dump_cooked, regcache_dump_groups,
 201   regcache_dump_remote
 202 };
 203
 204 /* A (register_number, register_value) pair.  */
 205
 206 typedef struct cached_reg
 207 {
 208   int num;
 209   gdb_byte *data;
 210 } cached_reg_t;
 211
 212 /* Buffer of registers.  */
 213
 214 class reg_buffer
 215 {
 216 public:
 217   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 218
 219   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 220
 221   /* Return regcache's architecture.  */
 222   gdbarch *arch () const;
 223
 224   enum register_status get_register_status (int regnum) const;
 225
 226   virtual ~reg_buffer ()
 227   {
 228     xfree (m_registers);
 229     xfree (m_register_status);
 230   }
 231 protected:
 232   /* Assert on the range of REGNUM.  */
 233   void assert_regnum (int regnum) const;
 234
 235   int num_raw_registers () const;
 236
 237   gdb_byte *register_buffer (int regnum) const;
 238
 239   /* Save a register cache.  The set of registers saved into the
 240      regcache determined by the save_reggroup.  COOKED_READ returns
 241      zero iff the register's value can't be returned.  */
 242   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 243
 244   struct regcache_descr *m_descr;
 245
 246   bool m_has_pseudo;
 247   /* The register buffers.  */
 248   gdb_byte *m_registers;
 249   /* Register cache status.  */
 250   signed char *m_register_status;
 251
 252   friend class regcache;
 253   friend class detached_regcache;
 254 };
 255
 256 /* An abstract class which only has methods doing read.  */
 257
 258 class readable_regcache : public reg_buffer
 259 {
 260 public:
 261   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 262     : reg_buffer (gdbarch, has_pseudo)
 263   {}
 264
 265   enum register_status raw_read (int regnum, gdb_byte *buf);
 266   template<typename T, typename = RequireLongest<T>>
 267   enum register_status raw_read (int regnum, T *val);
 268
 269   enum register_status raw_read_part (int regnum, int offset, int len,
 270                                       gdb_byte *buf);
 271
 272   virtual void raw_update (int regnum) = 0;
 273
 274   enum register_status cooked_read (int regnum, gdb_byte *buf);
 275   template<typename T, typename = RequireLongest<T>>
 276   enum register_status cooked_read (int regnum, T *val);
 277
 278   enum register_status cooked_read_part (int regnum, int offset, int len,
 279                                          gdb_byte *buf);
 280
 281   struct value *cooked_read_value (int regnum);
 282
 283 protected:
 284   enum register_status read_part (int regnum, int offset, int len, void *in,
 285                                   bool is_raw);
 286 };
 287
 288 /* Buffer of registers, can be read and written.  */
 289
 290 class detached_regcache : public readable_regcache
 291 {
 292 public:
 293   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 294     : readable_regcache (gdbarch, has_pseudo)
 295   {}
 296
 297   void raw_supply (int regnum, const void *buf);
 298
 299   void raw_supply (int regnum, const reg_buffer &src)
 300   {
 301     raw_supply (regnum, src.register_buffer (regnum));
 302   }
 303
 304   void raw_update (int regnum) override
 305   {}
 306
 307   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 308 };
 309
 310 class readonly_detached_regcache;
 311
 312 /* The register cache for storing raw register values.  */
 313
 314 class regcache : public detached_regcache
 315 {
 316 public:
 317   regcache (gdbarch *gdbarch)
 318     : regcache (gdbarch, nullptr, true)
 319   {}
 320
 321   struct readonly_t {};
 322   static constexpr readonly_t readonly {};
 323
 324   /* Create a readonly regcache from a non-readonly regcache.  */
 325   regcache (readonly_t, const regcache &src);
 326
 327   DISABLE_COPY_AND_ASSIGN (regcache);
 328
 329   /* Return REGCACHE's address space.  */
 330   const address_space *aspace () const
 331   {
 332     return m_aspace;
 333   }
 334
 335   /* Restore 'this' regcache.  The set of registers restored into
 336      the regcache determined by the restore_reggroup.
 337      Writes to regcache will go through to the target.  SRC is a
 338      read-only register cache.  */
 339   void restore (readonly_detached_regcache *src);
 340
 341   void cooked_write (int regnum, const gdb_byte *buf);
 342
 343   void raw_write (int regnum, const gdb_byte *buf);
 344
 345   template<typename T, typename = RequireLongest<T>>
 346   void raw_write (int regnum, T val);
 347
 348   template<typename T, typename = RequireLongest<T>>
 349   void cooked_write (int regnum, T val);
 350
 351   void raw_update (int regnum) override;
 352
 353   void raw_collect (int regnum, void *buf) const;
 354
 355   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 356                             bool is_signed) const;
 357
 358   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 359                            bool is_signed);
 360
 361   void raw_supply_zeroed (int regnum);
 362
 363   void invalidate (int regnum);
 364
 365   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 366
 367   void cooked_write_part (int regnum, int offset, int len,
 368                           const gdb_byte *buf);
 369
 370   void supply_regset (const struct regset *regset,
 371                       int regnum, const void *buf, size_t size);
 372
 373
 374   void collect_regset (const struct regset *regset, int regnum,
 375                        void *buf, size_t size) const;
 376
 377   void dump (ui_file *file, enum regcache_dump_what what_to_dump);
 378
 379   ptid_t ptid () const
 380   {
 381     return m_ptid;
 382   }
 383
 384   void set_ptid (const ptid_t ptid)
 385   {
 386     this->m_ptid = ptid;
 387   }
 388
 389 /* Dump the contents of a register from the register cache to the target
 390    debug.  */
 391   void debug_print_register (const char *func, int regno);
 392
 393   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 394 protected:
 395   regcache (gdbarch *gdbarch, const address_space *aspace_, bool readonly_p_);
 396   static std::forward_list<regcache *> current_regcache;
 397
 398 private:
 399
 400   void transfer_regset (const struct regset *regset,
 401                         struct regcache *out_regcache,
 402                         int regnum, const void *in_buf,
 403                         void *out_buf, size_t size) const;
 404
 405   enum register_status write_part (int regnum, int offset, int len,
 406                                    const void *out, bool is_raw);
 407
 408
 409   /* The address space of this register cache (for registers where it
 410      makes sense, like PC or SP).  */
 411   const address_space * const m_aspace;
 412
 413   /* Is this a read-only cache?  A read-only cache is used for saving
 414      the target's register state (e.g, across an inferior function
 415      call or just before forcing a function return).  A read-only
 416      cache can only be created via a constructor.  The actual contents
 417      are determined by the save and restore methods.  */
 418   const bool m_readonly_p;
 419   /* If this is a read-write cache, which thread's registers is
 420      it connected to?  */
 421   ptid_t m_ptid;
 422
 423   friend struct regcache *
 424   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 425                                    struct address_space *aspace);
 426
 427   friend void
 428   registers_changed_ptid (ptid_t ptid);
 429 };
 430
 431 class readonly_detached_regcache : public readable_regcache
 432 {
 433 public:
 434   readonly_detached_regcache (const regcache &src);
 435
 436   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 437
 438   readonly_detached_regcache (gdbarch *gdbarch,
 439                               regcache_cooked_read_ftype *cooked_read,
 440                               void *src)
 441     : readable_regcache (gdbarch, true)
 442   {
 443     save (cooked_read, src);
 444   }
 445
 446   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 447
 448   void raw_update (int regnum) override
 449   {}
 450 };
 451
 452 extern void registers_changed (void);
 453 extern void registers_changed_ptid (ptid_t);
 454
 455 #endif /* REGCACHE_H */