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 /* Partial transfer of raw registers.  These perform read, modify,
  54    write style operations.  The read variant returns the status of the
  55    register.  */
  56
  57 extern enum register_status
  58   regcache_raw_read_part (struct regcache *regcache, int regnum,
  59                           int offset, int len, gdb_byte *buf);
  60 void regcache_raw_write_part (struct regcache *regcache, int regnum,
  61                               int offset, int len, const gdb_byte *buf);
  62
  63 void regcache_invalidate (struct regcache *regcache, int regnum);
  64
  65 /* Transfer of pseudo-registers.  The read variants return a register
  66    status, as an indication of when a ``cooked'' register was
  67    constructed from valid, invalid or unavailable ``raw''
  68    registers.  */
  69
  70 /* Transfer a cooked register [0..NUM_REGS+NUM_PSEUDO_REGS).  */
  71 enum register_status regcache_cooked_read (struct regcache *regcache,
  72                                            int rawnum, gdb_byte *buf);
  73 void regcache_cooked_write (struct regcache *regcache, int rawnum,
  74                             const gdb_byte *buf);
  75
  76 /* Read register REGNUM from REGCACHE and return a new value.  This
  77    will call mark_value_bytes_unavailable as appropriate.  */
  78
  79 struct value *regcache_cooked_read_value (struct regcache *regcache,
  80                                           int regnum);
  81
  82 /* Read a register as a signed/unsigned quantity.  */
  83 extern enum register_status
  84   regcache_cooked_read_signed (struct regcache *regcache,
  85                                int regnum, LONGEST *val);
  86 extern enum register_status
  87   regcache_cooked_read_unsigned (struct regcache *regcache,
  88                                  int regnum, ULONGEST *val);
  89 extern void regcache_cooked_write_signed (struct regcache *regcache,
  90                                           int regnum, LONGEST val);
  91 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
  92                                             int regnum, ULONGEST val);
  93
  94 /* Partial transfer of a cooked register.  These perform read, modify,
  95    write style operations.  */
  96
  97 enum register_status regcache_cooked_read_part (struct regcache *regcache,
  98                                                 int regnum, int offset,
  99                                                 int len, gdb_byte *buf);
 100 void regcache_cooked_write_part (struct regcache *regcache, int regnum,
 101                                  int offset, int len, const gdb_byte *buf);
 102
 103 /* Special routines to read/write the PC.  */
 104
 105 /* For regcache_read_pc see common/common-regcache.h.  */
 106 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
 107
 108 /* Transfer a raw register [0..NUM_REGS) between the regcache and the
 109    target.  These functions are called by the target in response to a
 110    target_fetch_registers() or target_store_registers().  */
 111
 112 extern void regcache_raw_supply (struct regcache *regcache,
 113                                  int regnum, const void *buf);
 114 extern void regcache_raw_collect (const struct regcache *regcache,
 115                                   int regnum, void *buf);
 116
 117 /* Mapping between register numbers and offsets in a buffer, for use
 118    in the '*regset' functions below.  In an array of
 119    'regcache_map_entry' each element is interpreted like follows:
 120
 121    - If 'regno' is a register number: Map register 'regno' to the
 122      current offset (starting with 0) and increase the current offset
 123      by 'size' (or the register's size, if 'size' is zero).  Repeat
 124      this with consecutive register numbers up to 'regno+count-1'.
 125
 126    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
 127      offset.
 128
 129    - If count=0: End of the map.  */
 130
 131 struct regcache_map_entry
 132 {
 133   int count;
 134   int regno;
 135   int size;
 136 };
 137
 138 /* Special value for the 'regno' field in the struct above.  */
 139
 140 enum
 141   {
 142     REGCACHE_MAP_SKIP = -1,
 143   };
 144
 145 /* Transfer a set of registers (as described by REGSET) between
 146    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 147    belonging to the regset, otherwise just the register numbered
 148    REGNUM.  The REGSET's 'regmap' field must point to an array of
 149    'struct regcache_map_entry'.
 150
 151    These functions are suitable for the 'regset_supply' and
 152    'regset_collect' fields in a regset structure.  */
 153
 154 extern void regcache_supply_regset (const struct regset *regset,
 155                                     struct regcache *regcache,
 156                                     int regnum, const void *buf,
 157                                     size_t size);
 158 extern void regcache_collect_regset (const struct regset *regset,
 159                                      const struct regcache *regcache,
 160                                      int regnum, void *buf, size_t size);
 161
 162
 163 /* The type of a register.  This function is slightly more efficient
 164    then its gdbarch vector counterpart since it returns a precomputed
 165    value stored in a table.  */
 166
 167 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 168
 169
 170 /* Return the size of register REGNUM.  All registers should have only
 171    one size.  */
 172
 173 extern int register_size (struct gdbarch *gdbarch, int regnum);
 174
 175 typedef enum register_status (regcache_cooked_read_ftype) (void *src,
 176                                                            int regnum,
 177                                                            gdb_byte *buf);
 178
 179 /* A (register_number, register_value) pair.  */
 180
 181 typedef struct cached_reg
 182 {
 183   int num;
 184   gdb_byte *data;
 185 } cached_reg_t;
 186
 187 /* Buffer of registers.  */
 188
 189 class reg_buffer
 190 {
 191 public:
 192   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 193
 194   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 195
 196   /* Return regcache's architecture.  */
 197   gdbarch *arch () const;
 198
 199   /* Get the availability status of the value of register REGNUM in this
 200      buffer.  */
 201   enum register_status get_register_status (int regnum) const;
 202
 203   virtual ~reg_buffer ()
 204   {
 205     xfree (m_registers);
 206     xfree (m_register_status);
 207   }
 208 protected:
 209   /* Assert on the range of REGNUM.  */
 210   void assert_regnum (int regnum) const;
 211
 212   int num_raw_registers () const;
 213
 214   gdb_byte *register_buffer (int regnum) const;
 215
 216   /* Save a register cache.  The set of registers saved into the
 217      regcache determined by the save_reggroup.  COOKED_READ returns
 218      zero iff the register's value can't be returned.  */
 219   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 220
 221   struct regcache_descr *m_descr;
 222
 223   bool m_has_pseudo;
 224   /* The register buffers.  */
 225   gdb_byte *m_registers;
 226   /* Register cache status.  */
 227   signed char *m_register_status;
 228
 229   friend class regcache;
 230   friend class detached_regcache;
 231 };
 232
 233 /* An abstract class which only has methods doing read.  */
 234
 235 class readable_regcache : public reg_buffer
 236 {
 237 public:
 238   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 239     : reg_buffer (gdbarch, has_pseudo)
 240   {}
 241
 242   /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
 243      return its value in *BUF and return its availability status.  */
 244
 245   enum register_status raw_read (int regnum, gdb_byte *buf);
 246   template<typename T, typename = RequireLongest<T>>
 247   enum register_status raw_read (int regnum, T *val);
 248
 249   enum register_status raw_read_part (int regnum, int offset, int len,
 250                                       gdb_byte *buf);
 251
 252   /* Make certain that the register REGNUM is up-to-date.  */
 253   virtual void raw_update (int regnum) = 0;
 254
 255   enum register_status cooked_read (int regnum, gdb_byte *buf);
 256   template<typename T, typename = RequireLongest<T>>
 257   enum register_status cooked_read (int regnum, T *val);
 258
 259   enum register_status cooked_read_part (int regnum, int offset, int len,
 260                                          gdb_byte *buf);
 261
 262   struct value *cooked_read_value (int regnum);
 263
 264 protected:
 265   enum register_status read_part (int regnum, int offset, int len, void *in,
 266                                   bool is_raw);
 267 };
 268
 269 /* Buffer of registers, can be read and written.  */
 270
 271 class detached_regcache : public readable_regcache
 272 {
 273 public:
 274   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 275     : readable_regcache (gdbarch, has_pseudo)
 276   {}
 277
 278   void raw_supply (int regnum, const void *buf);
 279
 280   void raw_supply (int regnum, const reg_buffer &src)
 281   {
 282     raw_supply (regnum, src.register_buffer (regnum));
 283   }
 284
 285   void raw_update (int regnum) override
 286   {}
 287
 288   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 289                            bool is_signed);
 290
 291   void raw_supply_zeroed (int regnum);
 292
 293   void invalidate (int regnum);
 294
 295   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 296 };
 297
 298 class readonly_detached_regcache;
 299
 300 /* The register cache for storing raw register values.  */
 301
 302 class regcache : public detached_regcache
 303 {
 304 public:
 305   DISABLE_COPY_AND_ASSIGN (regcache);
 306
 307   /* Return REGCACHE's address space.  */
 308   const address_space *aspace () const
 309   {
 310     return m_aspace;
 311   }
 312
 313   /* Restore 'this' regcache.  The set of registers restored into
 314      the regcache determined by the restore_reggroup.
 315      Writes to regcache will go through to the target.  SRC is a
 316      read-only register cache.  */
 317   void restore (readonly_detached_regcache *src);
 318
 319   void cooked_write (int regnum, const gdb_byte *buf);
 320
 321   /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and
 322      transfer its value to core-gdb.  */
 323
 324   void raw_write (int regnum, const gdb_byte *buf);
 325
 326   template<typename T, typename = RequireLongest<T>>
 327   void raw_write (int regnum, T val);
 328
 329   template<typename T, typename = RequireLongest<T>>
 330   void cooked_write (int regnum, T val);
 331
 332   void raw_update (int regnum) override;
 333
 334   void raw_collect (int regnum, void *buf) const;
 335
 336   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 337                             bool is_signed) const;
 338
 339   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 340
 341   void cooked_write_part (int regnum, int offset, int len,
 342                           const gdb_byte *buf);
 343
 344   void supply_regset (const struct regset *regset,
 345                       int regnum, const void *buf, size_t size);
 346
 347
 348   void collect_regset (const struct regset *regset, int regnum,
 349                        void *buf, size_t size) const;
 350
 351   /* Return REGCACHE's ptid.  */
 352
 353   ptid_t ptid () const
 354   {
 355     gdb_assert (m_ptid != minus_one_ptid);
 356
 357     return m_ptid;
 358   }
 359
 360   void set_ptid (const ptid_t ptid)
 361   {
 362     this->m_ptid = ptid;
 363   }
 364
 365 /* Dump the contents of a register from the register cache to the target
 366    debug.  */
 367   void debug_print_register (const char *func, int regno);
 368
 369   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 370 protected:
 371   regcache (gdbarch *gdbarch, const address_space *aspace_);
 372   static std::forward_list<regcache *> current_regcache;
 373
 374 private:
 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   enum register_status write_part (int regnum, int offset, int len,
 382                                    const void *out, bool is_raw);
 383
 384
 385   /* The address space of this register cache (for registers where it
 386      makes sense, like PC or SP).  */
 387   const address_space * const m_aspace;
 388
 389   /* If this is a read-write cache, which thread's registers is
 390      it connected to?  */
 391   ptid_t m_ptid;
 392
 393   friend struct regcache *
 394   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 395                                    struct address_space *aspace);
 396
 397   friend void
 398   registers_changed_ptid (ptid_t ptid);
 399 };
 400
 401 class readonly_detached_regcache : public readable_regcache
 402 {
 403 public:
 404   readonly_detached_regcache (const regcache &src);
 405
 406   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 407
 408   readonly_detached_regcache (gdbarch *gdbarch,
 409                               regcache_cooked_read_ftype *cooked_read,
 410                               void *src)
 411     : readable_regcache (gdbarch, true)
 412   {
 413     save (cooked_read, src);
 414   }
 415
 416   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 417
 418   void raw_update (int regnum) override
 419   {}
 420 };
 421
 422 extern void registers_changed (void);
 423 extern void registers_changed_ptid (ptid_t);
 424
 425 /* An abstract base class for register dump.  */
 426
 427 class register_dump
 428 {
 429 public:
 430   void dump (ui_file *file);
 431   virtual ~register_dump () = default;
 432
 433 protected:
 434   register_dump (gdbarch *arch)
 435     : m_gdbarch (arch)
 436   {}
 437
 438   /* Dump the register REGNUM contents.  If REGNUM is -1, print the
 439      header.  */
 440   virtual void dump_reg (ui_file *file, int regnum) = 0;
 441
 442   gdbarch *m_gdbarch;
 443 };
 444
 445 #endif /* REGCACHE_H */