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
  34 /* Get the regcache of THREAD.  */
  35 extern struct regcache *get_thread_regcache (thread_info *thread);
  36
  37 extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);
  38 extern struct regcache *get_thread_arch_aspace_regcache (ptid_t,
  39                                                          struct gdbarch *,
  40                                                          struct address_space *);
  41
  42 extern enum register_status
  43   regcache_raw_read_signed (struct regcache *regcache,
  44                             int regnum, LONGEST *val);
  45
  46 extern void regcache_raw_write_signed (struct regcache *regcache,
  47                                        int regnum, LONGEST val);
  48 extern void regcache_raw_write_unsigned (struct regcache *regcache,
  49                                          int regnum, ULONGEST val);
  50
  51 /* Return the register's value in signed or throw if it's not
  52    available.  */
  53
  54 extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
  55                                         int regnum);
  56
  57 /* Read a register as a signed/unsigned quantity.  */
  58 extern enum register_status
  59   regcache_cooked_read_signed (struct regcache *regcache,
  60                                int regnum, LONGEST *val);
  61 extern enum register_status
  62   regcache_cooked_read_unsigned (struct regcache *regcache,
  63                                  int regnum, ULONGEST *val);
  64 extern void regcache_cooked_write_signed (struct regcache *regcache,
  65                                           int regnum, LONGEST val);
  66 extern void regcache_cooked_write_unsigned (struct regcache *regcache,
  67                                             int regnum, ULONGEST val);
  68
  69 /* Special routines to read/write the PC.  */
  70
  71 /* For regcache_read_pc see common/common-regcache.h.  */
  72 extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);
  73
  74 /* Mapping between register numbers and offsets in a buffer, for use
  75    in the '*regset' functions below.  In an array of
  76    'regcache_map_entry' each element is interpreted like follows:
  77
  78    - If 'regno' is a register number: Map register 'regno' to the
  79      current offset (starting with 0) and increase the current offset
  80      by 'size' (or the register's size, if 'size' is zero).  Repeat
  81      this with consecutive register numbers up to 'regno+count-1'.
  82
  83    - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
  84      offset.
  85
  86    - If count=0: End of the map.  */
  87
  88 struct regcache_map_entry
  89 {
  90   int count;
  91   int regno;
  92   int size;
  93 };
  94
  95 /* Special value for the 'regno' field in the struct above.  */
  96
  97 enum
  98   {
  99     REGCACHE_MAP_SKIP = -1,
 100   };
 101
 102 /* Transfer a set of registers (as described by REGSET) between
 103    REGCACHE and BUF.  If REGNUM == -1, transfer all registers
 104    belonging to the regset, otherwise just the register numbered
 105    REGNUM.  The REGSET's 'regmap' field must point to an array of
 106    'struct regcache_map_entry'.
 107
 108    These functions are suitable for the 'regset_supply' and
 109    'regset_collect' fields in a regset structure.  */
 110
 111 extern void regcache_supply_regset (const struct regset *regset,
 112                                     struct regcache *regcache,
 113                                     int regnum, const void *buf,
 114                                     size_t size);
 115 extern void regcache_collect_regset (const struct regset *regset,
 116                                      const struct regcache *regcache,
 117                                      int regnum, void *buf, size_t size);
 118
 119
 120 /* The type of a register.  This function is slightly more efficient
 121    then its gdbarch vector counterpart since it returns a precomputed
 122    value stored in a table.  */
 123
 124 extern struct type *register_type (struct gdbarch *gdbarch, int regnum);
 125
 126
 127 /* Return the size of register REGNUM.  All registers should have only
 128    one size.  */
 129
 130 extern int register_size (struct gdbarch *gdbarch, int regnum);
 131
 132 typedef gdb::function_view<register_status (int regnum, gdb_byte *buf)>
 133   register_read_ftype;
 134
 135 /* A (register_number, register_value) pair.  */
 136
 137 typedef struct cached_reg
 138 {
 139   int num;
 140   gdb_byte *data;
 141 } cached_reg_t;
 142
 143 /* Buffer of registers.  */
 144
 145 class reg_buffer : public reg_buffer_common
 146 {
 147 public:
 148   reg_buffer (gdbarch *gdbarch, bool has_pseudo);
 149
 150   DISABLE_COPY_AND_ASSIGN (reg_buffer);
 151
 152   /* Return regcache's architecture.  */
 153   gdbarch *arch () const;
 154
 155   /* See common/common-regcache.h.  */
 156   enum register_status get_register_status (int regnum) const override;
 157
 158   /* See common/common-regcache.h.  */
 159   void raw_collect (int regnum, void *buf) const override;
 160
 161   /* Collect register REGNUM from REGCACHE.  Store collected value as an integer
 162      at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
 163      If ADDR_LEN is greater than the register size, then the integer will be
 164      sign or zero extended.  If ADDR_LEN is smaller than the register size, then
 165      the most significant bytes of the integer will be truncated.  */
 166   void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
 167                             bool is_signed) const;
 168
 169   /* See common/common-regcache.h.  */
 170   void raw_supply (int regnum, const void *buf) override;
 171
 172   void raw_supply (int regnum, const reg_buffer &src)
 173   {
 174     raw_supply (regnum, src.register_buffer (regnum));
 175   }
 176
 177   /* Supply register REGNUM to REGCACHE.  Value to supply is an integer stored
 178      at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
 179      If the register size is greater than ADDR_LEN, then the integer will be
 180      sign or zero extended.  If the register size is smaller than the integer,
 181      then the most significant bytes of the integer will be truncated.  */
 182   void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
 183                            bool is_signed);
 184
 185   /* Supply register REGNUM with zeroed value to REGCACHE.  This is not the same
 186      as calling raw_supply with NULL (which will set the state to
 187      unavailable).  */
 188   void raw_supply_zeroed (int regnum);
 189
 190   void invalidate (int regnum);
 191
 192   virtual ~reg_buffer () = default;
 193
 194   /* See common/common-regcache.h.  */
 195   bool raw_compare (int regnum, const void *buf, int offset) const override;
 196
 197 protected:
 198   /* Assert on the range of REGNUM.  */
 199   void assert_regnum (int regnum) const;
 200
 201   int num_raw_registers () const;
 202
 203   gdb_byte *register_buffer (int regnum) const;
 204
 205   /* Save a register cache.  The set of registers saved into the
 206      regcache determined by the save_reggroup.  COOKED_READ returns
 207      zero iff the register's value can't be returned.  */
 208   void save (register_read_ftype cooked_read);
 209
 210   struct regcache_descr *m_descr;
 211
 212   bool m_has_pseudo;
 213   /* The register buffers.  */
 214   std::unique_ptr<gdb_byte[]> m_registers;
 215   /* Register cache status.  */
 216   std::unique_ptr<register_status[]> m_register_status;
 217
 218   friend class regcache;
 219   friend class detached_regcache;
 220 };
 221
 222 /* An abstract class which only has methods doing read.  */
 223
 224 class readable_regcache : public reg_buffer
 225 {
 226 public:
 227   readable_regcache (gdbarch *gdbarch, bool has_pseudo)
 228     : reg_buffer (gdbarch, has_pseudo)
 229   {}
 230
 231   /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
 232      return its value in *BUF and return its availability status.  */
 233
 234   enum register_status raw_read (int regnum, gdb_byte *buf);
 235   template<typename T, typename = RequireLongest<T>>
 236   enum register_status raw_read (int regnum, T *val);
 237
 238   /* Partial transfer of raw registers.  Return the status of the register.  */
 239   enum register_status raw_read_part (int regnum, int offset, int len,
 240                                       gdb_byte *buf);
 241
 242   /* Make certain that the register REGNUM is up-to-date.  */
 243   virtual void raw_update (int regnum) = 0;
 244
 245   /* Transfer a raw register [0..NUM_REGS+NUM_PSEUDO_REGS) from core-gdb to
 246      this regcache, return its value in *BUF and return its availability status.  */
 247   enum register_status cooked_read (int regnum, gdb_byte *buf);
 248   template<typename T, typename = RequireLongest<T>>
 249   enum register_status cooked_read (int regnum, T *val);
 250
 251   /* Partial transfer of a cooked register.  */
 252   enum register_status cooked_read_part (int regnum, int offset, int len,
 253                                          gdb_byte *buf);
 254
 255   /* Read register REGNUM from the regcache and return a new value.  This
 256      will call mark_value_bytes_unavailable as appropriate.  */
 257   struct value *cooked_read_value (int regnum);
 258
 259 protected:
 260
 261   /* Perform a partial register transfer using a read, modify, write
 262      operation.  Will fail if register is currently invalid.  */
 263   enum register_status read_part (int regnum, int offset, int len,
 264                                   gdb_byte *out, bool is_raw);
 265 };
 266
 267 /* Buffer of registers, can be read and written.  */
 268
 269 class detached_regcache : public readable_regcache
 270 {
 271 public:
 272   detached_regcache (gdbarch *gdbarch, bool has_pseudo)
 273     : readable_regcache (gdbarch, has_pseudo)
 274   {}
 275
 276   void raw_update (int regnum) override
 277   {}
 278
 279   DISABLE_COPY_AND_ASSIGN (detached_regcache);
 280 };
 281
 282 class readonly_detached_regcache;
 283
 284 /* The register cache for storing raw register values.  */
 285
 286 class regcache : public detached_regcache
 287 {
 288 public:
 289   DISABLE_COPY_AND_ASSIGN (regcache);
 290
 291   /* Return REGCACHE's address space.  */
 292   const address_space *aspace () const
 293   {
 294     return m_aspace;
 295   }
 296
 297   /* Restore 'this' regcache.  The set of registers restored into
 298      the regcache determined by the restore_reggroup.
 299      Writes to regcache will go through to the target.  SRC is a
 300      read-only register cache.  */
 301   void restore (readonly_detached_regcache *src);
 302
 303   /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and
 304      transfer its value to core-gdb.  */
 305
 306   void raw_write (int regnum, const gdb_byte *buf);
 307
 308   template<typename T, typename = RequireLongest<T>>
 309   void raw_write (int regnum, T val);
 310
 311   /* Transfer of pseudo-registers.  */
 312   void cooked_write (int regnum, const gdb_byte *buf);
 313
 314   template<typename T, typename = RequireLongest<T>>
 315   void cooked_write (int regnum, T val);
 316
 317   void raw_update (int regnum) override;
 318
 319   /* Partial transfer of raw registers.  Perform read, modify, write style
 320      operations.  */
 321   void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);
 322
 323   /* Partial transfer of a cooked register.  Perform read, modify, write style
 324      operations.  */
 325   void cooked_write_part (int regnum, int offset, int len,
 326                           const gdb_byte *buf);
 327
 328   void supply_regset (const struct regset *regset,
 329                       int regnum, const void *buf, size_t size);
 330
 331
 332   void collect_regset (const struct regset *regset, int regnum,
 333                        void *buf, size_t size) const;
 334
 335   /* Return REGCACHE's ptid.  */
 336
 337   ptid_t ptid () const
 338   {
 339     gdb_assert (m_ptid != minus_one_ptid);
 340
 341     return m_ptid;
 342   }
 343
 344   void set_ptid (const ptid_t ptid)
 345   {
 346     this->m_ptid = ptid;
 347   }
 348
 349 /* Dump the contents of a register from the register cache to the target
 350    debug.  */
 351   void debug_print_register (const char *func, int regno);
 352
 353   static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
 354 protected:
 355   regcache (gdbarch *gdbarch, const address_space *aspace_);
 356
 357   static std::forward_list<regcache *> current_regcache;
 358
 359 private:
 360
 361   void transfer_regset (const struct regset *regset,
 362                         struct regcache *out_regcache,
 363                         int regnum, const void *in_buf,
 364                         void *out_buf, size_t size) const;
 365
 366   /* Perform a partial register transfer using a read, modify, write
 367      operation.  */
 368   enum register_status write_part (int regnum, int offset, int len,
 369                                    const gdb_byte *in, bool is_raw);
 370
 371   /* The address space of this register cache (for registers where it
 372      makes sense, like PC or SP).  */
 373   const address_space * const m_aspace;
 374
 375   /* If this is a read-write cache, which thread's registers is
 376      it connected to?  */
 377   ptid_t m_ptid;
 378
 379   friend struct regcache *
 380   get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
 381                                    struct address_space *aspace);
 382
 383   friend void
 384   registers_changed_ptid (ptid_t ptid);
 385 };
 386
 387 class readonly_detached_regcache : public readable_regcache
 388 {
 389 public:
 390   readonly_detached_regcache (regcache &src);
 391
 392   /* Create a readonly regcache by getting contents from COOKED_READ.  */
 393
 394   readonly_detached_regcache (gdbarch *gdbarch, register_read_ftype cooked_read)
 395     : readable_regcache (gdbarch, true)
 396   {
 397     save (cooked_read);
 398   }
 399
 400   DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);
 401
 402   void raw_update (int regnum) override
 403   {}
 404 };
 405
 406 extern void registers_changed (void);
 407 extern void registers_changed_ptid (ptid_t);
 408
 409 /* Indicate that registers of THREAD may have changed, so invalidate
 410    the cache.  */
 411 extern void registers_changed_thread (thread_info *thread);
 412
 413 /* An abstract base class for register dump.  */
 414
 415 class register_dump
 416 {
 417 public:
 418   void dump (ui_file *file);
 419   virtual ~register_dump () = default;
 420
 421 protected:
 422   register_dump (gdbarch *arch)
 423     : m_gdbarch (arch)
 424   {}
 425
 426   /* Dump the register REGNUM contents.  If REGNUM is -1, print the
 427      header.  */
 428   virtual void dump_reg (ui_file *file, int regnum) = 0;
 429
 430   gdbarch *m_gdbarch;
 431 };
 432
 433 #endif /* REGCACHE_H */