aboutsummaryrefslogtreecommitdiff
path: root/gdb/regcache.h
blob: 374826cdb822efd7f8fbede38f9c3032f6d7db63 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
/* Cache and manage the values of registers for GDB, the GNU debugger.

   Copyright (C) 1986-2018 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef REGCACHE_H
#define REGCACHE_H

#include "common-regcache.h"
#include <forward_list>

struct regcache;
struct regset;
struct gdbarch;
struct address_space;

extern struct regcache *get_current_regcache (void);
extern struct regcache *get_thread_regcache (ptid_t ptid);

/* Get the regcache of THREAD.  */
extern struct regcache *get_thread_regcache (thread_info *thread);

extern struct regcache *get_thread_arch_regcache (ptid_t, struct gdbarch *);
extern struct regcache *get_thread_arch_aspace_regcache (ptid_t,
							 struct gdbarch *,
							 struct address_space *);

extern enum register_status
  regcache_raw_read_signed (struct regcache *regcache,
			    int regnum, LONGEST *val);

extern void regcache_raw_write_signed (struct regcache *regcache,
				       int regnum, LONGEST val);
extern void regcache_raw_write_unsigned (struct regcache *regcache,
					 int regnum, ULONGEST val);

/* Return the register's value in signed or throw if it's not
   available.  */

extern LONGEST regcache_raw_get_signed (struct regcache *regcache,
					int regnum);

/* Read a register as a signed/unsigned quantity.  */
extern enum register_status
  regcache_cooked_read_signed (struct regcache *regcache,
			       int regnum, LONGEST *val);
extern enum register_status
  regcache_cooked_read_unsigned (struct regcache *regcache,
				 int regnum, ULONGEST *val);
extern void regcache_cooked_write_signed (struct regcache *regcache,
					  int regnum, LONGEST val);
extern void regcache_cooked_write_unsigned (struct regcache *regcache,
					    int regnum, ULONGEST val);

/* Special routines to read/write the PC.  */

/* For regcache_read_pc see common/common-regcache.h.  */
extern void regcache_write_pc (struct regcache *regcache, CORE_ADDR pc);

/* Mapping between register numbers and offsets in a buffer, for use
   in the '*regset' functions below and with traditional frame caches.
   In an array of 'regcache_map_entry' each element is interpreted
   like follows:

   - If 'regno' is a register number: Map register 'regno' to the
     current offset (starting with 0) and increase the current offset
     by 'size' (or the register's size, if 'size' is zero).  Repeat
     this with consecutive register numbers up to 'regno+count-1'.

     For each described register, if 'size' is larger than the
     register's size, the register's value is assumed to be stored in
     the first N (where N is the register size) bytes at the current
     offset.  The remaining 'size' - N bytes are filled with zeroes by
     'regcache_collect_regset' and ignored by other consumers.

     If 'size' is smaller than the register's size, only the first
     'size' bytes of a register's value are assumed to be stored at
     the current offset.  'regcache_collect_regset' copies the first
     'size' bytes of a register's value to the output buffer.
     'regcache_supply_regset' copies the bytes from the input buffer
     into the first 'size' bytes of the register's value leaving the
     remaining bytes of the register's value unchanged.  Frame caches
     read the 'size' bytes from the stack frame and zero extend them
     to generate the register's value.

   - If 'regno' is REGCACHE_MAP_SKIP: Add 'count*size' to the current
     offset.

   - If count=0: End of the map.  */

struct regcache_map_entry
{
  int count;
  int regno;
  int size;
};

/* Special value for the 'regno' field in the struct above.  */

enum
  {
    REGCACHE_MAP_SKIP = -1,
  };

/* Calculate and return the total size of all the registers in a
   regcache_map_entry.  */

static inline int
regcache_map_entry_size (const struct regcache_map_entry *map)
{
  int size = 0;
  for (int i = 0; map[i].count != 0; i++)
    size += (map[i].count * map[i].size);
  return size;
}

/* Transfer a set of registers (as described by REGSET) between
   REGCACHE and BUF.  If REGNUM == -1, transfer all registers
   belonging to the regset, otherwise just the register numbered
   REGNUM.  The REGSET's 'regmap' field must point to an array of
   'struct regcache_map_entry'.

   These functions are suitable for the 'regset_supply' and
   'regset_collect' fields in a regset structure.  */

extern void regcache_supply_regset (const struct regset *regset,
				    struct regcache *regcache,
				    int regnum, const void *buf,
				    size_t size);
extern void regcache_collect_regset (const struct regset *regset,
				     const struct regcache *regcache,
				     int regnum, void *buf, size_t size);


/* The type of a register.  This function is slightly more efficient
   then its gdbarch vector counterpart since it returns a precomputed
   value stored in a table.  */

extern struct type *register_type (struct gdbarch *gdbarch, int regnum);


/* Return the size of register REGNUM.  All registers should have only
   one size.  */
   
extern int register_size (struct gdbarch *gdbarch, int regnum);

typedef gdb::function_view<register_status (int regnum, gdb_byte *buf)>
  register_read_ftype;

/* A (register_number, register_value) pair.  */

typedef struct cached_reg
{
  int num;
  gdb_byte *data;
} cached_reg_t;

/* Buffer of registers.  */

class reg_buffer : public reg_buffer_common
{
public:
  reg_buffer (gdbarch *gdbarch, bool has_pseudo);

  DISABLE_COPY_AND_ASSIGN (reg_buffer);

  /* Return regcache's architecture.  */
  gdbarch *arch () const;

  /* See common/common-regcache.h.  */
  enum register_status get_register_status (int regnum) const override;

  /* See common/common-regcache.h.  */
  void raw_collect (int regnum, void *buf) const override;

  /* Collect register REGNUM from REGCACHE.  Store collected value as an integer
     at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
     If ADDR_LEN is greater than the register size, then the integer will be
     sign or zero extended.  If ADDR_LEN is smaller than the register size, then
     the most significant bytes of the integer will be truncated.  */
  void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
			    bool is_signed) const;

  /* Collect register REGNUM from REGCACHE, starting at OFFSET in register,
     reading only LEN.  */
  void raw_collect_part (int regnum, int offset, int len, gdb_byte *out) const;

  /* See common/common-regcache.h.  */
  void raw_supply (int regnum, const void *buf) override;

  void raw_supply (int regnum, const reg_buffer &src)
  {
    raw_supply (regnum, src.register_buffer (regnum));
  }

  /* Supply register REGNUM to REGCACHE.  Value to supply is an integer stored
     at address ADDR, in target endian, with length ADDR_LEN and sign IS_SIGNED.
     If the register size is greater than ADDR_LEN, then the integer will be
     sign or zero extended.  If the register size is smaller than the integer,
     then the most significant bytes of the integer will be truncated.  */
  void raw_supply_integer (int regnum, const gdb_byte *addr, int addr_len,
			   bool is_signed);

  /* Supply register REGNUM with zeroed value to REGCACHE.  This is not the same
     as calling raw_supply with NULL (which will set the state to
     unavailable).  */
  void raw_supply_zeroed (int regnum);

  /* Supply register REGNUM to REGCACHE, starting at OFFSET in register, writing
     only LEN, without editing the rest of the register.  */
  void raw_supply_part (int regnum, int offset, int len, const gdb_byte *in);

  void invalidate (int regnum);

  virtual ~reg_buffer () = default;

  /* See common/common-regcache.h.  */
  bool raw_compare (int regnum, const void *buf, int offset) const override;

protected:
  /* Assert on the range of REGNUM.  */
  void assert_regnum (int regnum) const;

  int num_raw_registers () const;

  gdb_byte *register_buffer (int regnum) const;

  /* Save a register cache.  The set of registers saved into the
     regcache determined by the save_reggroup.  COOKED_READ returns
     zero iff the register's value can't be returned.  */
  void save (register_read_ftype cooked_read);

  struct regcache_descr *m_descr;

  bool m_has_pseudo;
  /* The register buffers.  */
  std::unique_ptr<gdb_byte[]> m_registers;
  /* Register cache status.  */
  std::unique_ptr<register_status[]> m_register_status;

  friend class regcache;
  friend class detached_regcache;
};

/* An abstract class which only has methods doing read.  */

class readable_regcache : public reg_buffer
{
public:
  readable_regcache (gdbarch *gdbarch, bool has_pseudo)
    : reg_buffer (gdbarch, has_pseudo)
  {}

  /* Transfer a raw register [0..NUM_REGS) from core-gdb to this regcache,
     return its value in *BUF and return its availability status.  */

  enum register_status raw_read (int regnum, gdb_byte *buf);
  template<typename T, typename = RequireLongest<T>>
  enum register_status raw_read (int regnum, T *val);

  /* Partial transfer of raw registers.  Return the status of the register.  */
  enum register_status raw_read_part (int regnum, int offset, int len,
				      gdb_byte *buf);

  /* Make certain that the register REGNUM is up-to-date.  */
  virtual void raw_update (int regnum) = 0;

  /* Transfer a raw register [0..NUM_REGS+NUM_PSEUDO_REGS) from core-gdb to
     this regcache, return its value in *BUF and return its availability status.  */
  enum register_status cooked_read (int regnum, gdb_byte *buf);
  template<typename T, typename = RequireLongest<T>>
  enum register_status cooked_read (int regnum, T *val);

  /* Partial transfer of a cooked register.  */
  enum register_status cooked_read_part (int regnum, int offset, int len,
					 gdb_byte *buf);

  /* Read register REGNUM from the regcache and return a new value.  This
     will call mark_value_bytes_unavailable as appropriate.  */
  struct value *cooked_read_value (int regnum);

protected:

  /* Perform a partial register transfer using a read, modify, write
     operation.  Will fail if register is currently invalid.  */
  enum register_status read_part (int regnum, int offset, int len,
				  gdb_byte *out, bool is_raw);
};

/* Buffer of registers, can be read and written.  */

class detached_regcache : public readable_regcache
{
public:
  detached_regcache (gdbarch *gdbarch, bool has_pseudo)
    : readable_regcache (gdbarch, has_pseudo)
  {}

  void raw_update (int regnum) override
  {}

  DISABLE_COPY_AND_ASSIGN (detached_regcache);
};

class readonly_detached_regcache;

/* The register cache for storing raw register values.  */

class regcache : public detached_regcache
{
public:
  DISABLE_COPY_AND_ASSIGN (regcache);

  /* Return REGCACHE's address space.  */
  const address_space *aspace () const
  {
    return m_aspace;
  }

  /* Restore 'this' regcache.  The set of registers restored into
     the regcache determined by the restore_reggroup.
     Writes to regcache will go through to the target.  SRC is a
     read-only register cache.  */
  void restore (readonly_detached_regcache *src);

  /* Update the value of raw register REGNUM (in the range [0..NUM_REGS)) and
     transfer its value to core-gdb.  */

  void raw_write (int regnum, const gdb_byte *buf);

  template<typename T, typename = RequireLongest<T>>
  void raw_write (int regnum, T val);

  /* Transfer of pseudo-registers.  */
  void cooked_write (int regnum, const gdb_byte *buf);

  template<typename T, typename = RequireLongest<T>>
  void cooked_write (int regnum, T val);

  void raw_update (int regnum) override;

  /* Partial transfer of raw registers.  Perform read, modify, write style
     operations.  */
  void raw_write_part (int regnum, int offset, int len, const gdb_byte *buf);

  /* Partial transfer of a cooked register.  Perform read, modify, write style
     operations.  */
  void cooked_write_part (int regnum, int offset, int len,
			  const gdb_byte *buf);

  void supply_regset (const struct regset *regset,
		      int regnum, const void *buf, size_t size);


  void collect_regset (const struct regset *regset, int regnum,
		       void *buf, size_t size) const;

  /* Return REGCACHE's ptid.  */

  ptid_t ptid () const
  {
    gdb_assert (m_ptid != minus_one_ptid);

    return m_ptid;
  }

  void set_ptid (const ptid_t ptid)
  {
    this->m_ptid = ptid;
  }

/* Dump the contents of a register from the register cache to the target
   debug.  */
  void debug_print_register (const char *func, int regno);

  static void regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid);
protected:
  regcache (gdbarch *gdbarch, const address_space *aspace_);

  static std::forward_list<regcache *> current_regcache;

private:

  /* Helper function for transfer_regset.  Copies across a single register.  */
  void transfer_regset_register (struct regcache *out_regcache, int regnum,
				 const gdb_byte *in_buf, gdb_byte *out_buf,
				 int slot_size, int offs) const;

  /* Transfer a single or all registers belonging to a certain register
     set to or from a buffer.  This is the main worker function for
     regcache_supply_regset and regcache_collect_regset.  */
  void transfer_regset (const struct regset *regset,
			struct regcache *out_regcache,
			int regnum, const gdb_byte *in_buf,
			gdb_byte *out_buf, size_t size) const;

  /* Perform a partial register transfer using a read, modify, write
     operation.  */
  enum register_status write_part (int regnum, int offset, int len,
				   const gdb_byte *in, bool is_raw);

  /* The address space of this register cache (for registers where it
     makes sense, like PC or SP).  */
  const address_space * const m_aspace;

  /* If this is a read-write cache, which thread's registers is
     it connected to?  */
  ptid_t m_ptid;

  friend struct regcache *
  get_thread_arch_aspace_regcache (ptid_t ptid, struct gdbarch *gdbarch,
				   struct address_space *aspace);

  friend void
  registers_changed_ptid (ptid_t ptid);
};

class readonly_detached_regcache : public readable_regcache
{
public:
  readonly_detached_regcache (regcache &src);

  /* Create a readonly regcache by getting contents from COOKED_READ.  */

  readonly_detached_regcache (gdbarch *gdbarch, register_read_ftype cooked_read)
    : readable_regcache (gdbarch, true)
  {
    save (cooked_read);
  }

  DISABLE_COPY_AND_ASSIGN (readonly_detached_regcache);

  void raw_update (int regnum) override
  {}
};

extern void registers_changed (void);
extern void registers_changed_ptid (ptid_t);

/* Indicate that registers of THREAD may have changed, so invalidate
   the cache.  */
extern void registers_changed_thread (thread_info *thread);

/* An abstract base class for register dump.  */

class register_dump
{
public:
  void dump (ui_file *file);
  virtual ~register_dump () = default;

protected:
  register_dump (gdbarch *arch)
    : m_gdbarch (arch)
  {}

  /* Dump the register REGNUM contents.  If REGNUM is -1, print the
     header.  */
  virtual void dump_reg (ui_file *file, int regnum) = 0;

  gdbarch *m_gdbarch;
};

#endif /* REGCACHE_H */