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