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