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