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 ()
 157   {
 158     xfree (m_registers);
 159     xfree (m_register_status);
 160   }
 161 protected:
 162   /* Assert on the range of REGNUM.  */
 163   void assert_regnum (int regnum) const;
 164
 165   int num_raw_registers () const;
 166
 167   gdb_byte *register_buffer (int regnum) const;
 168
 169   /* Save a register cache.  The set of registers saved into the
 170      regcache determined by the save_reggroup.  COOKED_READ returns
 171      zero iff the register's value can't be returned.  */
 172   void save (regcache_cooked_read_ftype *cooked_read, void *src);
 173
 174   struct regcache_descr *m_descr;
 175
 176   bool m_has_pseudo;
 177   /* The register buffers.  */
 178   gdb_byte *m_registers;
 179   /* Register cache status.  */
 180   signed char *m_register_status;
 181
 182   friend class regcache;
 183   friend class detached_regcache;
 184 };
 185
 186 /* An abstract class which only has methods doing read.  */
 187
 188 class readable_regcache : public reg_buffer
 189 {
 190 public:
 191   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 192     : reg_buffer (gdbarch, has_pseudo)
 193   {}
 194
 195   /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
 196      return its value in *BUF and return its availability status.  */
 197
 198   enum register_status raw_read (int regnum, gdb_byte *buf);
 199   template<typename T, typename = RequireLongest<T>>
 200   enum register_status raw_read (int regnum, T *val);
 201
 202   /* Partial transfer of raw registers.  Return the status of the register.  */
 203   enum register_status raw_read_part (int regnum, int offset, int len,
 204                                       gdb_byte *buf);
 205
 206   /* Make certain that the register REGNUM is up-to-date.  */
 207   virtual void raw_update (int regnum) = 0;
 208
 209   /* Transfer a raw register [0..NUM_REGS+NUM_PSEUDO_REGS) from core-gdb to
 210      this regcache, return its value in *BUF and return its availability status.  */
 211   enum register_status cooked_read (int regnum, gdb_byte *buf);
 212   template<typename T, typename = RequireLongest<T>>
 213   enum register_status cooked_read (int regnum, T *val);
 214
 215   /* Partial transfer of a cooked register.  */
 216   enum register_status cooked_read_part (int regnum, int offset, int len,
 217                                          gdb_byte *buf);
 218
 219   /* Read register REGNUM from the regcache and return a new value.  This
 220      will call mark_value_bytes_unavailable as appropriate.  */
 221   struct value *cooked_read_value (int regnum);
 222
 223 protected:
 224   enum register_status read_part (int regnum, int offset, int len, void *in,
 225                                   bool is_raw);
 226 };
 227
 228 /* Buffer of registers, can be read and written.  */
 229
 230 class detached_regcache : public readable_regcache
 231 {
 232 public:
 233   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 234     : readable_regcache (gdbarch, has_pseudo)
 235   {}
 236
 237   /* Supply register REGNUM, whose contents are stored in BUF, to REGCACHE.  */
 238   void raw_supply (int regnum, const void *buf);
 239
 240   void raw_supply (int regnum, const reg_buffer &src)
 241   {
 242     raw_supply (regnum, src.register_buffer (regnum));
 243   }
 244
 245   void raw_update (int regnum) override
 246   {}
 247
 248   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 249                            bool is_signed);
 250
 251   void raw_supply_zeroed (int regnum);
 252
 253   void invalidate (int regnum);
 254
 255   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 256 };
 257
 258 class readonly_detached_regcache;
 259
 260 /* The register cache for storing raw register values.  */
 261
 262 class regcache : public detached_regcache
 263 {
 264 public:
 265   DISABLE_COPY_AND_ASSIGN (regcache);
 266
 267   /* Return REGCACHE's address space.  */
 268   const address_space *aspace () const
 269   {
 270     return m_aspace;
 271   }
 272
 273   /* Restore 'this' regcache.  The set of registers restored into
 274      the regcache determined by the restore_reggroup.
 275      Writes to regcache will go through to the target.  SRC is a
 276      read-only register cache.  */
 277   void restore (readonly_detached_regcache *src);
 278
 279   /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and
 280      transfer its value to core-gdb.  */
 281
 282   void raw_write (int regnum, const gdb_byte *buf);
 283
 284   template<typename T, typename = RequireLongest<T>>
 285   void raw_write (int regnum, T val);
 286
 287   /* Transfer of pseudo-registers.  */
 288   void cooked_write (int regnum, const gdb_byte *buf);
 289
 290   template<typename T, typename = RequireLongest<T>>
 291   void cooked_write (int regnum, T val);
 292
 293   void raw_update (int regnum) override;
 294
 295   /* Collect register REGNUM from REGCACHE and store its contents in BUF.  */
 296   void raw_collect (int regnum, void *buf) const;
 297
 298   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 299                             bool is_signed) const;
 300
 301   /* Partial transfer of raw registers.  Perform read, modify, write style
 302      operations.  */
 303   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 304
 305   /* Partial transfer of a cooked register.  Perform read, modify, write style
 306      operations.  */
 307   void cooked_write_part (int regnum, int offset, int len,
 308                           const gdb_byte *buf);
 309
 310   void supply_regset (const struct regset *regset,
 311                       int regnum, const void *buf, size_t size);
 312
 313
 314   void collect_regset (const struct regset *regset, int regnum,
 315                        void *buf, size_t size) const;
 316
 317   /* Return REGCACHE's ptid.  */
 318
 319   ptid_t ptid () const
 320   {
 321     gdb_assert (m_ptid != minus_one_ptid);
 322
 323     return m_ptid;
 324   }
 325
 326   void set_ptid (const ptid_t ptid)
 327   {
 328     this->m_ptid = ptid;
 329   }
 330
 331 /* Dump the contents of a register from the register cache to the target
 332    debug.  */
 333   void debug_print_register (const char *func, int regno);
 334
 335   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 336 protected:
 337   regcache (gdbarch *gdbarch, const address_space *aspace_);
 338   static std::forward_list<regcache *> current_regcache;
 339
 340 private:
 341
 342   void transfer_regset (const struct regset *regset,
 343                         struct regcache *out_regcache,
 344                         int regnum, const void *in_buf,
 345                         void *out_buf, size_t size) const;
 346
 347   enum register_status write_part (int regnum, int offset, int len,
 348                                    const void *out, bool is_raw);
 349
 350
 351   /* The address space of this register cache (for registers where it
 352      makes sense, like PC or SP).  */
 353   const address_space * const m_aspace;
 354
 355   /* If this is a read-write cache, which thread's registers is
 356      it connected to?  */
 357   ptid_t m_ptid;
 358
 359   friend struct regcache *
 360   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 361                                    struct address_space *aspace);
 362
 363   friend void
 364   registers_changed_ptid (ptid_t ptid);
 365 };
 366
 367 class readonly_detached_regcache : public readable_regcache
 368 {
 369 public:
 370   readonly_detached_regcache (const regcache &src);
 371
 372   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 373
 374   readonly_detached_regcache (gdbarch *gdbarch,
 375                               regcache_cooked_read_ftype *cooked_read,
 376                               void *src)
 377     : readable_regcache (gdbarch, true)
 378   {
 379     save (cooked_read, src);
 380   }
 381
 382   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 383
 384   void raw_update (int regnum) override
 385   {}
 386 };
 387
 388 extern void registers_changed (void);
 389 extern void registers_changed_ptid (ptid_t);
 390
 391 /* An abstract base class for register dump.  */
 392
 393 class register_dump
 394 {
 395 public:
 396   void dump (ui_file *file);
 397   virtual ~register_dump () = default;
 398
 399 protected:
 400   register_dump (gdbarch *arch)
 401     : m_gdbarch (arch)
 402   {}
 403
 404   /* Dump the register REGNUM contents.  If REGNUM is -1, print the
 405      header.  */
 406   virtual void dump_reg (ui_file *file, int regnum) = 0;
 407
 408   gdbarch *m_gdbarch;
 409 };
 410
 411 #endif /* REGCACHE_H */