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 /* A (register_number, register_value) pair.  */
 198
 199 typedef struct cached_reg
 200 {
 201   int num;
 202   gdb_byte *data;
 203 } cached_reg_t;
 204
 205 /* Buffer of registers.  */
 206
 207 class reg_buffer
 208 {
 209 public:
 210   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 211
 212   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 213
 214   /* Return regcache's architecture.  */
 215   gdbarch *arch () const;
 216
 217   enum register_status get_register_status (int regnum) const;
 218
 219   virtual ~reg_buffer ()
 220   {
 221     xfree (m_registers);
 222     xfree (m_register_status);
 223   }
 224 protected:
 225   /* Assert on the range of REGNUM.  */
 226   void assert_regnum (int regnum) const;
 227
 228   int num_raw_registers () const;
 229
 230   gdb_byte *register_buffer (int regnum) const;
 231
 232   /* Save a register cache.  The set of registers saved into the
 233      regcache determined by the save_reggroup.  COOKED_READ returns
 234      zero iff the register's value can't be returned.  */
 235   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 236
 237   struct regcache_descr *m_descr;
 238
 239   bool m_has_pseudo;
 240   /* The register buffers.  */
 241   gdb_byte *m_registers;
 242   /* Register cache status.  */
 243   signed char *m_register_status;
 244
 245   friend class regcache;
 246   friend class detached_regcache;
 247 };
 248
 249 /* An abstract class which only has methods doing read.  */
 250
 251 class readable_regcache : public reg_buffer
 252 {
 253 public:
 254   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 255     : reg_buffer (gdbarch, has_pseudo)
 256   {}
 257
 258   enum register_status raw_read (int regnum, gdb_byte *buf);
 259   template<typename T, typename = RequireLongest<T>>
 260   enum register_status raw_read (int regnum, T *val);
 261
 262   enum register_status raw_read_part (int regnum, int offset, int len,
 263                                       gdb_byte *buf);
 264
 265   virtual void raw_update (int regnum) = 0;
 266
 267   enum register_status cooked_read (int regnum, gdb_byte *buf);
 268   template<typename T, typename = RequireLongest<T>>
 269   enum register_status cooked_read (int regnum, T *val);
 270
 271   enum register_status cooked_read_part (int regnum, int offset, int len,
 272                                          gdb_byte *buf);
 273
 274   struct value *cooked_read_value (int regnum);
 275
 276 protected:
 277   enum register_status read_part (int regnum, int offset, int len, void *in,
 278                                   bool is_raw);
 279 };
 280
 281 /* Buffer of registers, can be read and written.  */
 282
 283 class detached_regcache : public readable_regcache
 284 {
 285 public:
 286   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 287     : readable_regcache (gdbarch, has_pseudo)
 288   {}
 289
 290   void raw_supply (int regnum, const void *buf);
 291
 292   void raw_supply (int regnum, const reg_buffer &src)
 293   {
 294     raw_supply (regnum, src.register_buffer (regnum));
 295   }
 296
 297   void raw_update (int regnum) override
 298   {}
 299
 300   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 301 };
 302
 303 class readonly_detached_regcache;
 304
 305 /* The register cache for storing raw register values.  */
 306
 307 class regcache : public detached_regcache
 308 {
 309 public:
 310   DISABLE_COPY_AND_ASSIGN (regcache);
 311
 312   /* Return REGCACHE's address space.  */
 313   const address_space *aspace () const
 314   {
 315     return m_aspace;
 316   }
 317
 318   /* Restore 'this' regcache.  The set of registers restored into
 319      the regcache determined by the restore_reggroup.
 320      Writes to regcache will go through to the target.  SRC is a
 321      read-only register cache.  */
 322   void restore (readonly_detached_regcache *src);
 323
 324   void cooked_write (int regnum, const gdb_byte *buf);
 325
 326   void raw_write (int regnum, const gdb_byte *buf);
 327
 328   template<typename T, typename = RequireLongest<T>>
 329   void raw_write (int regnum, T val);
 330
 331   template<typename T, typename = RequireLongest<T>>
 332   void cooked_write (int regnum, T val);
 333
 334   void raw_update (int regnum) override;
 335
 336   void raw_collect (int regnum, void *buf) const;
 337
 338   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 339                             bool is_signed) const;
 340
 341   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 342                            bool is_signed);
 343
 344   void raw_supply_zeroed (int regnum);
 345
 346   void invalidate (int regnum);
 347
 348   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 349
 350   void cooked_write_part (int regnum, int offset, int len,
 351                           const gdb_byte *buf);
 352
 353   void supply_regset (const struct regset *regset,
 354                       int regnum, const void *buf, size_t size);
 355
 356
 357   void collect_regset (const struct regset *regset, int regnum,
 358                        void *buf, size_t size) const;
 359
 360   ptid_t ptid () const
 361   {
 362     return m_ptid;
 363   }
 364
 365   void set_ptid (const ptid_t ptid)
 366   {
 367     this->m_ptid = ptid;
 368   }
 369
 370 /* Dump the contents of a register from the register cache to the target
 371    debug.  */
 372   void debug_print_register (const char *func, int regno);
 373
 374   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 375 protected:
 376   regcache (gdbarch *gdbarch, const address_space *aspace_, bool readonly_p_);
 377   static std::forward_list<regcache *> current_regcache;
 378
 379 private:
 380
 381   void transfer_regset (const struct regset *regset,
 382                         struct regcache *out_regcache,
 383                         int regnum, const void *in_buf,
 384                         void *out_buf, size_t size) const;
 385
 386   enum register_status write_part (int regnum, int offset, int len,
 387                                    const void *out, bool is_raw);
 388
 389
 390   /* The address space of this register cache (for registers where it
 391      makes sense, like PC or SP).  */
 392   const address_space * const m_aspace;
 393
 394   /* Is this a read-only cache?  A read-only cache is used for saving
 395      the target's register state (e.g, across an inferior function
 396      call or just before forcing a function return).  A read-only
 397      cache can only be created via a constructor.  The actual contents
 398      are determined by the save and restore methods.  */
 399   const bool m_readonly_p;
 400   /* If this is a read-write cache, which thread's registers is
 401      it connected to?  */
 402   ptid_t m_ptid;
 403
 404   friend struct regcache *
 405   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 406                                    struct address_space *aspace);
 407
 408   friend void
 409   registers_changed_ptid (ptid_t ptid);
 410 };
 411
 412 class readonly_detached_regcache : public readable_regcache
 413 {
 414 public:
 415   readonly_detached_regcache (const regcache &src);
 416
 417   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 418
 419   readonly_detached_regcache (gdbarch *gdbarch,
 420                               regcache_cooked_read_ftype *cooked_read,
 421                               void *src)
 422     : readable_regcache (gdbarch, true)
 423   {
 424     save (cooked_read, src);
 425   }
 426
 427   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 428
 429   void raw_update (int regnum) override
 430   {}
 431 };
 432
 433 extern void registers_changed (void);
 434 extern void registers_changed_ptid (ptid_t);
 435
 436 #endif /* REGCACHE_H */