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