gdb/regcache.h

   1 /* Cache and manage the values of registers for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2017 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 void regcache_xfree (struct regcache *regcache);
  39 struct cleanup *make_cleanup_regcache_xfree (struct regcache *regcache);
  40 struct regcache *regcache_xmalloc (struct gdbarch *gdbarch,
  41                                    struct address_space *aspace);
  42
  43 /* Return REGCACHE's ptid.  */
  44
  45 extern ptid_t regcache_get_ptid (const struct regcache *regcache);
  46
  47 /* Return REGCACHE's architecture.  */
  48
  49 extern struct gdbarch *get_regcache_arch (const struct regcache *regcache);
  50
  51 /* Return REGCACHE's address space.  */
  52
  53 extern struct address_space *get_regcache_aspace (const struct regcache *);
  54
  55 enum register_status regcache_register_status (const struct regcache *regcache,
  56                                                int regnum);
  57
  58 /* Make certain that the register REGNUM in REGCACHE is up-to-date.  */
  59
  60 void regcache_raw_update (struct regcache *regcache, int regnum);
  61
  62 /* Transfer a raw register [0..NUM_REGS) between core-gdb and the
  63    regcache.  The read variants return the status of the register.  */
  64
  65 enum register_status regcache_raw_read (struct regcache *regcache,
  66                                         int rawnum, gdb_byte *buf);
  67 void regcache_raw_write (struct regcache *regcache, int rawnum,
  68                          const gdb_byte *buf);
  69 extern enum register_status
  70   regcache_raw_read_signed (struct regcache *regcache,
  71                             int regnum, LONGEST *val);
  72
  73 extern void regcache_raw_write_signed (struct regcache *regcache,
  74                                        int regnum, LONGEST val);
  75 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  76                                          int regnum, ULONGEST val);
  77
  78 /* Return the register's value in signed or throw if it's not
  79    available.  */
  80
  81 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  82                                         int regnum);
  83
  84 /* Set a raw register's value in the regcache's buffer.  Unlike
  85    regcache_raw_write, this is not write-through.  The intention is
  86    allowing to change the buffer contents of a read-only regcache
  87    allocated with regcache_xmalloc.  */
  88
  89 extern void regcache_raw_set_cached_value
  90   (struct regcache *regcache, int regnum, const gdb_byte *buf);
  91
  92 /* Partial transfer of raw registers.  These perform read, modify,
  93    write style operations.  The read variant returns the status of the
  94    register.  */
  95
  96 extern enum register_status
  97   regcache_raw_read_part (struct regcache *regcache, int regnum,
  98                           int offset, int len, gdb_byte *buf);
  99 void regcache_raw_write_part (struct regcache *regcache, int regnum,
 100                               int offset, int len, const gdb_byte *buf);
 101
 102 void regcache_invalidate (struct regcache *regcache, int regnum);
 103
 104 /* Transfer of pseudo-registers.  The read variants return a register
 105    status, as an indication of when a ``cooked'' register was
 106    constructed from valid, invalid or unavailable ``raw''
 107    registers.  */
 108
 109 /* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
 110 enum register_status regcache_cooked_read (struct regcache *regcache,
 111                                            int rawnum, gdb_byte *buf);
 112 void regcache_cooked_write (struct regcache *regcache, int rawnum,
 113                             const gdb_byte *buf);
 114
 115 /* Read register REGNUM from REGCACHE and return a new value.  This
 116    will call mark_value_bytes_unavailable as appropriate.  */
 117
 118 struct value *regcache_cooked_read_value (struct regcache *regcache,
 119                                           int regnum);
 120
 121 /* Read a register as a signed/unsigned quantity.  */
 122 extern enum register_status
 123   regcache_cooked_read_signed (struct regcache *regcache,
 124                                int regnum, LONGEST *val);
 125 extern enum register_status
 126   regcache_cooked_read_unsigned (struct regcache *regcache,
 127                                  int regnum, ULONGEST *val);
 128 extern void regcache_cooked_write_signed (struct regcache *regcache,
 129                                           int regnum, LONGEST val);
 130 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
 131                                             int regnum, ULONGEST val);
 132
 133 /* Partial transfer of a cooked register.  These perform read, modify,
 134    write style operations.  */
 135
 136 enum register_status regcache_cooked_read_part (struct regcache *regcache,
 137                                                 int regnum, int offset,
 138                                                 int len, gdb_byte *buf);
 139 void regcache_cooked_write_part (struct regcache *regcache, int regnum,
 140                                  int offset, int len, const gdb_byte *buf);
 141
 142 /* Special routines to read/write the PC.  */
 143
 144 /* For regcache_read_pc see common/common-regcache.h.  */
 145 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
 146
 147 /* Transfer a raw register [0..NUM_REGS) between the regcache and the
 148    target.  These functions are called by the target in response to a
 149    target_fetch_registers() or target_store_registers().  */
 150
 151 extern void regcache_raw_supply (struct regcache *regcache,
 152                                  int regnum, const void *buf);
 153 extern void regcache_raw_collect (const struct regcache *regcache,
 154                                   int regnum, void *buf);
 155
 156 /* Mapping between register numbers and offsets in a buffer, for use
 157    in the '*regset' functions below.  In an array of
 158    'regcache_map_entry' each element is interpreted like follows:
 159
 160    - If 'regno' is a register number: Map register 'regno' to the
 161      current offset (starting with 0) and increase the current offset
 162      by 'size' (or the register's size, if 'size' is zero).  Repeat
 163      this with consecutive register numbers up to 'regno+count-1'.
 164
 165    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
 166      offset.
 167
 168    - If count=0: End of the map.  */
 169
 170 struct regcache_map_entry
 171 {
 172   int count;
 173   int regno;
 174   int size;
 175 };
 176
 177 /* Special value for the 'regno' field in the struct above.  */
 178
 179 enum
 180   {
 181     REGCACHE_MAP_SKIP = -1,
 182   };
 183
 184 /* Transfer a set of registers (as described by REGSET) between
 185    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 186    belonging to the regset, otherwise just the register numbered
 187    REGNUM.  The REGSET's 'regmap' field must point to an array of
 188    'struct regcache_map_entry'.
 189
 190    These functions are suitable for the 'regset_supply' and
 191    'regset_collect' fields in a regset structure.  */
 192
 193 extern void regcache_supply_regset (const struct regset *regset,
 194                                     struct regcache *regcache,
 195                                     int regnum, const void *buf,
 196                                     size_t size);
 197 extern void regcache_collect_regset (const struct regset *regset,
 198                                      const struct regcache *regcache,
 199                                      int regnum, void *buf, size_t size);
 200
 201
 202 /* The type of a register.  This function is slightly more efficient
 203    then its gdbarch vector counterpart since it returns a precomputed
 204    value stored in a table.  */
 205
 206 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 207
 208
 209 /* Return the size of register REGNUM.  All registers should have only
 210    one size.  */
 211
 212 extern int register_size (struct gdbarch *gdbarch, int regnum);
 213
 214
 215 /* Save/restore a register cache.  The set of registers saved /
 216    restored into the DST regcache determined by the save_reggroup /
 217    restore_reggroup respectively.  COOKED_READ returns zero iff the
 218    register's value can't be returned.  */
 219
 220 typedef enum register_status (regcache_cooked_read_ftype) (void *src,
 221                                                            int regnum,
 222                                                            gdb_byte *buf);
 223
 224 extern void regcache_save (struct regcache *dst,
 225                            regcache_cooked_read_ftype *cooked_read,
 226                            void *cooked_read_context);
 227
 228 enum regcache_dump_what
 229 {
 230   regcache_dump_none, regcache_dump_raw,
 231   regcache_dump_cooked, regcache_dump_groups,
 232   regcache_dump_remote
 233 };
 234
 235 /* A (register_number, register_value) pair.  */
 236
 237 typedef struct cached_reg
 238 {
 239   int num;
 240   gdb_byte *data;
 241 } cached_reg_t;
 242
 243 /* The register cache for storing raw register values.  */
 244
 245 class regcache
 246 {
 247 public:
 248   regcache (gdbarch *gdbarch, address_space *aspace_)
 249     : regcache (gdbarch, aspace_, true)
 250   {}
 251
 252   struct readonly_t {};
 253   static constexpr readonly_t readonly {};
 254
 255   /* Create a readonly regcache from a non-readonly regcache.  */
 256   regcache (readonly_t, const regcache &src);
 257
 258   DISABLE_COPY_AND_ASSIGN (regcache);
 259
 260   /* class regcache is only extended in unit test, so only mark it
 261      virtual when selftest is enabled.  */
 262 #if GDB_SELF_TEST
 263   virtual
 264 #endif
 265   ~regcache ()
 266   {
 267     xfree (m_registers);
 268     xfree (m_register_status);
 269   }
 270
 271   gdbarch *arch () const;
 272
 273   address_space *aspace () const
 274   {
 275     return m_aspace;
 276   }
 277
 278   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 279
 280   enum register_status cooked_read (int regnum, gdb_byte *buf);
 281   void cooked_write (int regnum, const gdb_byte *buf);
 282
 283   enum register_status raw_read (int regnum, gdb_byte *buf);
 284
 285   /* class regcache is only extended in unit test, so only mark it
 286      virtual when selftest is enabled.  */
 287 #if GDB_SELF_TEST
 288   virtual
 289 #endif
 290   void raw_write (int regnum, const gdb_byte *buf);
 291
 292   template<typename T, typename = RequireLongest<T>>
 293   enum register_status raw_read (int regnum, T *val);
 294
 295   template<typename T, typename = RequireLongest<T>>
 296   void raw_write (int regnum, T val);
 297
 298   struct value *cooked_read_value (int regnum);
 299
 300   template<typename T, typename = RequireLongest<T>>
 301   enum register_status cooked_read (int regnum, T *val);
 302
 303   template<typename T, typename = RequireLongest<T>>
 304   void cooked_write (int regnum, T val);
 305
 306   void raw_update (int regnum);
 307
 308   void raw_collect (int regnum, void *buf) const;
 309
 310   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 311                             bool is_signed) const;
 312
 313   void raw_supply (int regnum, const void *buf);
 314
 315   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 316                            bool is_signed);
 317
 318   void raw_supply_zeroed (int regnum);
 319
 320   enum register_status get_register_status (int regnum) const;
 321
 322   void raw_set_cached_value (int regnum, const gdb_byte *buf);
 323
 324   void invalidate (int regnum);
 325
 326   enum register_status raw_read_part (int regnum, int offset, int len,
 327                                       gdb_byte *buf);
 328
 329   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 330
 331   enum register_status cooked_read_part (int regnum, int offset, int len,
 332                                          gdb_byte *buf);
 333
 334   void cooked_write_part (int regnum, int offset, int len,
 335                           const gdb_byte *buf);
 336
 337   void supply_regset (const struct regset *regset,
 338                       int regnum, const void *buf, size_t size);
 339
 340
 341   void collect_regset (const struct regset *regset, int regnum,
 342                        void *buf, size_t size) const;
 343
 344   void dump (ui_file *file, enum regcache_dump_what what_to_dump);
 345
 346   ptid_t ptid () const
 347   {
 348     return m_ptid;
 349   }
 350
 351   void set_ptid (const ptid_t ptid)
 352   {
 353     this->m_ptid = ptid;
 354   }
 355
 356 /* Dump the contents of a register from the register cache to the target
 357    debug.  */
 358   void debug_print_register (const char *func, int regno);
 359
 360   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 361 protected:
 362   regcache (gdbarch *gdbarch, address_space *aspace_, bool readonly_p_);
 363
 364   static std::forward_list<regcache *> current_regcache;
 365
 366 private:
 367   gdb_byte *register_buffer (int regnum) const;
 368
 369   void restore (struct regcache *src);
 370
 371   enum register_status xfer_part (int regnum, int offset, int len, void *in,
 372                                   const void *out,
 373                                   decltype (regcache_raw_read) read,
 374                                   decltype (regcache_raw_write) write);
 375
 376   void transfer_regset (const struct regset *regset,
 377                         struct regcache *out_regcache,
 378                         int regnum, const void *in_buf,
 379                         void *out_buf, size_t size) const;
 380
 381   struct regcache_descr *m_descr;
 382
 383   /* The address space of this register cache (for registers where it
 384      makes sense, like PC or SP).  */
 385   struct address_space *m_aspace;
 386
 387   /* The register buffers.  A read-only register cache can hold the
 388      full [0 .. gdbarch_num_regs + gdbarch_num_pseudo_regs) while a read/write
 389      register cache can only hold [0 .. gdbarch_num_regs).  */
 390   gdb_byte *m_registers;
 391   /* Register cache status.  */
 392   signed char *m_register_status;
 393   /* Is this a read-only cache?  A read-only cache is used for saving
 394      the target's register state (e.g, across an inferior function
 395      call or just before forcing a function return).  A read-only
 396      cache can only be updated via the methods regcache_dup() and
 397      regcache_cpy().  The actual contents are determined by the
 398      reggroup_save and reggroup_restore methods.  */
 399   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   friend void
 412   regcache_cpy (struct regcache *dst, struct regcache *src);
 413 };
 414
 415 /* Duplicate the contents of a register cache to a read-only register
 416    cache.  The operation is pass-through.  */
 417 extern struct regcache *regcache_dup (struct regcache *regcache);
 418
 419 /* Writes to DEST will go through to the target.  SRC is a read-only
 420    register cache.  */
 421 extern void regcache_cpy (struct regcache *dest, struct regcache *src);
 422
 423 extern void registers_changed (void);
 424 extern void registers_changed_ptid (ptid_t);
 425
 426 #endif /* REGCACHE_H */