1/* Register support routines for the remote server for GDB.
2   Copyright (C) 2001-2020 Free Software Foundation, Inc.
3
4   This file is part of GDB.
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 3 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18
19#include "server.h"
20#include "regdef.h"
21#include "gdbthread.h"
22#include "tdesc.h"
23#include "gdbsupport/rsp-low.h"
24#ifndef IN_PROCESS_AGENT
25
26struct regcache *
27get_thread_regcache (struct thread_info *thread, int fetch)
28{
29  struct regcache *regcache;
30
31  regcache = thread_regcache_data (thread);
32
33  /* Threads' regcaches are created lazily, because biarch targets add
34     the main thread/lwp before seeing it stop for the first time, and
35     it is only after the target sees the thread stop for the first
36     time that the target has a chance of determining the process's
37     architecture.  IOW, when we first add the process's main thread
38     we don't know which architecture/tdesc its regcache should
39     have.  */
40  if (regcache == NULL)
41    {
42      struct process_info *proc = get_thread_process (thread);
43
44      gdb_assert (proc->tdesc != NULL);
45
46      regcache = new_register_cache (proc->tdesc);
47      set_thread_regcache_data (thread, regcache);
48    }
49
50  if (fetch && regcache->registers_valid == 0)
51    {
52      struct thread_info *saved_thread = current_thread;
53
54      current_thread = thread;
55      /* Invalidate all registers, to prevent stale left-overs.  */
56      memset (regcache->register_status, REG_UNAVAILABLE,
57	      regcache->tdesc->reg_defs.size ());
58      fetch_inferior_registers (regcache, -1);
59      current_thread = saved_thread;
60      regcache->registers_valid = 1;
61    }
62
63  return regcache;
64}
65
66/* See gdbsupport/common-regcache.h.  */
67
68struct regcache *
69get_thread_regcache_for_ptid (ptid_t ptid)
70{
71  return get_thread_regcache (find_thread_ptid (ptid), 1);
72}
73
74void
75regcache_invalidate_thread (struct thread_info *thread)
76{
77  struct regcache *regcache;
78
79  regcache = thread_regcache_data (thread);
80
81  if (regcache == NULL)
82    return;
83
84  if (regcache->registers_valid)
85    {
86      struct thread_info *saved_thread = current_thread;
87
88      current_thread = thread;
89      store_inferior_registers (regcache, -1);
90      current_thread = saved_thread;
91    }
92
93  regcache->registers_valid = 0;
94}
95
96/* See regcache.h.  */
97
98void
99regcache_invalidate_pid (int pid)
100{
101  /* Only invalidate the regcaches of threads of this process.  */
102  for_each_thread (pid, regcache_invalidate_thread);
103}
104
105/* See regcache.h.  */
106
107void
108regcache_invalidate (void)
109{
110  /* Only update the threads of the current process.  */
111  int pid = current_thread->id.pid ();
112
113  regcache_invalidate_pid (pid);
114}
115
116#endif
117
118struct regcache *
119init_register_cache (struct regcache *regcache,
120		     const struct target_desc *tdesc,
121		     unsigned char *regbuf)
122{
123  if (regbuf == NULL)
124    {
125#ifndef IN_PROCESS_AGENT
126      /* Make sure to zero-initialize the register cache when it is
127	 created, in case there are registers the target never
128	 fetches.  This way they'll read as zero instead of
129	 garbage.  */
130      regcache->tdesc = tdesc;
131      regcache->registers
132	= (unsigned char *) xcalloc (1, tdesc->registers_size);
133      regcache->registers_owned = 1;
134      regcache->register_status
135	= (unsigned char *) xmalloc (tdesc->reg_defs.size ());
136      memset ((void *) regcache->register_status, REG_UNAVAILABLE,
137	      tdesc->reg_defs.size ());
138#else
139      gdb_assert_not_reached ("can't allocate memory from the heap");
140#endif
141    }
142  else
143    {
144      regcache->tdesc = tdesc;
145      regcache->registers = regbuf;
146      regcache->registers_owned = 0;
147#ifndef IN_PROCESS_AGENT
148      regcache->register_status = NULL;
149#endif
150    }
151
152  regcache->registers_valid = 0;
153
154  return regcache;
155}
156
157#ifndef IN_PROCESS_AGENT
158
159struct regcache *
160new_register_cache (const struct target_desc *tdesc)
161{
162  struct regcache *regcache = new struct regcache;
163
164  gdb_assert (tdesc->registers_size != 0);
165
166  return init_register_cache (regcache, tdesc, NULL);
167}
168
169void
170free_register_cache (struct regcache *regcache)
171{
172  if (regcache)
173    {
174      if (regcache->registers_owned)
175	free (regcache->registers);
176      free (regcache->register_status);
177      delete regcache;
178    }
179}
180
181#endif
182
183void
184regcache_cpy (struct regcache *dst, struct regcache *src)
185{
186  gdb_assert (src != NULL && dst != NULL);
187  gdb_assert (src->tdesc == dst->tdesc);
188  gdb_assert (src != dst);
189
190  memcpy (dst->registers, src->registers, src->tdesc->registers_size);
191#ifndef IN_PROCESS_AGENT
192  if (dst->register_status != NULL && src->register_status != NULL)
193    memcpy (dst->register_status, src->register_status,
194	    src->tdesc->reg_defs.size ());
195#endif
196  dst->registers_valid = src->registers_valid;
197}
198
199/* Return a reference to the description of register N.  */
200
201static const struct gdb::reg &
202find_register_by_number (const struct target_desc *tdesc, int n)
203{
204  return tdesc->reg_defs[n];
205}
206
207#ifndef IN_PROCESS_AGENT
208
209void
210registers_to_string (struct regcache *regcache, char *buf)
211{
212  unsigned char *registers = regcache->registers;
213  const struct target_desc *tdesc = regcache->tdesc;
214
215  for (int i = 0; i < tdesc->reg_defs.size (); ++i)
216    {
217      if (regcache->register_status[i] == REG_VALID)
218	{
219	  bin2hex (registers, buf, register_size (tdesc, i));
220	  buf += register_size (tdesc, i) * 2;
221	}
222      else
223	{
224	  memset (buf, 'x', register_size (tdesc, i) * 2);
225	  buf += register_size (tdesc, i) * 2;
226	}
227      registers += register_size (tdesc, i);
228    }
229  *buf = '\0';
230}
231
232void
233registers_from_string (struct regcache *regcache, char *buf)
234{
235  int len = strlen (buf);
236  unsigned char *registers = regcache->registers;
237  const struct target_desc *tdesc = regcache->tdesc;
238
239  if (len != tdesc->registers_size * 2)
240    {
241      warning ("Wrong sized register packet (expected %d bytes, got %d)",
242	       2 * tdesc->registers_size, len);
243      if (len > tdesc->registers_size * 2)
244	len = tdesc->registers_size * 2;
245    }
246  hex2bin (buf, registers, len / 2);
247}
248
249int
250find_regno (const struct target_desc *tdesc, const char *name)
251{
252  for (int i = 0; i < tdesc->reg_defs.size (); ++i)
253    {
254      if (strcmp (name, find_register_by_number (tdesc, i).name) == 0)
255	return i;
256    }
257  internal_error (__FILE__, __LINE__, "Unknown register %s requested",
258		  name);
259}
260
261static void
262free_register_cache_thread (struct thread_info *thread)
263{
264  struct regcache *regcache = thread_regcache_data (thread);
265
266  if (regcache != NULL)
267    {
268      regcache_invalidate_thread (thread);
269      free_register_cache (regcache);
270      set_thread_regcache_data (thread, NULL);
271    }
272}
273
274void
275regcache_release (void)
276{
277  /* Flush and release all pre-existing register caches.  */
278  for_each_thread (free_register_cache_thread);
279}
280#endif
281
282int
283register_cache_size (const struct target_desc *tdesc)
284{
285  return tdesc->registers_size;
286}
287
288int
289register_size (const struct target_desc *tdesc, int n)
290{
291  return find_register_by_number (tdesc, n).size / 8;
292}
293
294/* See gdbsupport/common-regcache.h.  */
295
296int
297regcache_register_size (const struct regcache *regcache, int n)
298{
299  return register_size (regcache->tdesc, n);
300}
301
302static unsigned char *
303register_data (const struct regcache *regcache, int n, int fetch)
304{
305  return (regcache->registers
306	  + find_register_by_number (regcache->tdesc, n).offset / 8);
307}
308
309void
310supply_register (struct regcache *regcache, int n, const void *buf)
311{
312  return regcache->raw_supply (n, buf);
313}
314
315/* See gdbsupport/common-regcache.h.  */
316
317void
318regcache::raw_supply (int n, const void *buf)
319{
320  if (buf)
321    {
322      memcpy (register_data (this, n, 0), buf, register_size (tdesc, n));
323#ifndef IN_PROCESS_AGENT
324      if (register_status != NULL)
325	register_status[n] = REG_VALID;
326#endif
327    }
328  else
329    {
330      memset (register_data (this, n, 0), 0, register_size (tdesc, n));
331#ifndef IN_PROCESS_AGENT
332      if (register_status != NULL)
333	register_status[n] = REG_UNAVAILABLE;
334#endif
335    }
336}
337
338/* Supply register N with value zero to REGCACHE.  */
339
340void
341supply_register_zeroed (struct regcache *regcache, int n)
342{
343  memset (register_data (regcache, n, 0), 0,
344	  register_size (regcache->tdesc, n));
345#ifndef IN_PROCESS_AGENT
346  if (regcache->register_status != NULL)
347    regcache->register_status[n] = REG_VALID;
348#endif
349}
350
351#ifndef IN_PROCESS_AGENT
352
353/* Supply register called NAME with value zero to REGCACHE.  */
354
355void
356supply_register_by_name_zeroed (struct regcache *regcache,
357				const char *name)
358{
359  supply_register_zeroed (regcache, find_regno (regcache->tdesc, name));
360}
361
362#endif
363
364/* Supply the whole register set whose contents are stored in BUF, to
365   REGCACHE.  If BUF is NULL, all the registers' values are recorded
366   as unavailable.  */
367
368void
369supply_regblock (struct regcache *regcache, const void *buf)
370{
371  if (buf)
372    {
373      const struct target_desc *tdesc = regcache->tdesc;
374
375      memcpy (regcache->registers, buf, tdesc->registers_size);
376#ifndef IN_PROCESS_AGENT
377      {
378	int i;
379
380	for (i = 0; i < tdesc->reg_defs.size (); i++)
381	  regcache->register_status[i] = REG_VALID;
382      }
383#endif
384    }
385  else
386    {
387      const struct target_desc *tdesc = regcache->tdesc;
388
389      memset (regcache->registers, 0, tdesc->registers_size);
390#ifndef IN_PROCESS_AGENT
391      {
392	int i;
393
394	for (i = 0; i < tdesc->reg_defs.size (); i++)
395	  regcache->register_status[i] = REG_UNAVAILABLE;
396      }
397#endif
398    }
399}
400
401#ifndef IN_PROCESS_AGENT
402
403void
404supply_register_by_name (struct regcache *regcache,
405			 const char *name, const void *buf)
406{
407  supply_register (regcache, find_regno (regcache->tdesc, name), buf);
408}
409
410#endif
411
412void
413collect_register (struct regcache *regcache, int n, void *buf)
414{
415  regcache->raw_collect (n, buf);
416}
417
418/* See gdbsupport/common-regcache.h.  */
419
420void
421regcache::raw_collect (int n, void *buf) const
422{
423  memcpy (buf, register_data (this, n, 1), register_size (tdesc, n));
424}
425
426enum register_status
427regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
428			    ULONGEST *val)
429{
430  int size;
431
432  gdb_assert (regcache != NULL);
433  gdb_assert (regnum >= 0
434	      && regnum < regcache->tdesc->reg_defs.size ());
435
436  size = register_size (regcache->tdesc, regnum);
437
438  if (size > (int) sizeof (ULONGEST))
439    error (_("That operation is not available on integers of more than"
440            "%d bytes."),
441          (int) sizeof (ULONGEST));
442
443  *val = 0;
444  collect_register (regcache, regnum, val);
445
446  return REG_VALID;
447}
448
449#ifndef IN_PROCESS_AGENT
450
451/* See regcache.h.  */
452
453ULONGEST
454regcache_raw_get_unsigned_by_name (struct regcache *regcache,
455				   const char *name)
456{
457  return regcache_raw_get_unsigned (regcache,
458				    find_regno (regcache->tdesc, name));
459}
460
461void
462collect_register_as_string (struct regcache *regcache, int n, char *buf)
463{
464  bin2hex (register_data (regcache, n, 1), buf,
465	   register_size (regcache->tdesc, n));
466}
467
468void
469collect_register_by_name (struct regcache *regcache,
470			  const char *name, void *buf)
471{
472  collect_register (regcache, find_regno (regcache->tdesc, name), buf);
473}
474
475/* Special handling for register PC.  */
476
477CORE_ADDR
478regcache_read_pc (struct regcache *regcache)
479{
480  return the_target->read_pc (regcache);
481}
482
483void
484regcache_write_pc (struct regcache *regcache, CORE_ADDR pc)
485{
486  the_target->write_pc (regcache, pc);
487}
488
489#endif
490
491/* See gdbsupport/common-regcache.h.  */
492
493enum register_status
494regcache::get_register_status (int regnum) const
495{
496#ifndef IN_PROCESS_AGENT
497  gdb_assert (regnum >= 0 && regnum < tdesc->reg_defs.size ());
498  return (enum register_status) (register_status[regnum]);
499#else
500  return REG_VALID;
501#endif
502}
503
504/* See gdbsupport/common-regcache.h.  */
505
506bool
507regcache::raw_compare (int regnum, const void *buf, int offset) const
508{
509  gdb_assert (buf != NULL);
510
511  const unsigned char *regbuf = register_data (this, regnum, 1);
512  int size = register_size (tdesc, regnum);
513  gdb_assert (size >= offset);
514
515  return (memcmp (buf, regbuf + offset, size - offset) == 0);
516}
517