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