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