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