xref: /dragonfly/contrib/gdb-7/gdb/target.c (revision bcb3e04d)
1 /* Select target systems and architectures at runtime for GDB.
2 
3    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5    Free Software Foundation, Inc.
6 
7    Contributed by Cygnus Support.
8 
9    This file is part of GDB.
10 
11    This program is free software; you can redistribute it and/or modify
12    it under the terms of the GNU General Public License as published by
13    the Free Software Foundation; either version 3 of the License, or
14    (at your option) any later version.
15 
16    This program is distributed in the hope that it will be useful,
17    but WITHOUT ANY WARRANTY; without even the implied warranty of
18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19    GNU General Public License for more details.
20 
21    You should have received a copy of the GNU General Public License
22    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
23 
24 #include "defs.h"
25 #include <errno.h>
26 #include "gdb_string.h"
27 #include "target.h"
28 #include "gdbcmd.h"
29 #include "symtab.h"
30 #include "inferior.h"
31 #include "bfd.h"
32 #include "symfile.h"
33 #include "objfiles.h"
34 #include "gdb_wait.h"
35 #include "dcache.h"
36 #include <signal.h>
37 #include "regcache.h"
38 #include "gdb_assert.h"
39 #include "gdbcore.h"
40 #include "exceptions.h"
41 #include "target-descriptions.h"
42 #include "gdbthread.h"
43 #include "solib.h"
44 #include "exec.h"
45 #include "inline-frame.h"
46 
47 static void target_info (char *, int);
48 
49 static void kill_or_be_killed (int);
50 
51 static void default_terminal_info (char *, int);
52 
53 static int default_watchpoint_addr_within_range (struct target_ops *,
54 						 CORE_ADDR, CORE_ADDR, int);
55 
56 static int default_region_ok_for_hw_watchpoint (CORE_ADDR, int);
57 
58 static int nosymbol (char *, CORE_ADDR *);
59 
60 static void tcomplain (void) ATTR_NORETURN;
61 
62 static int nomemory (CORE_ADDR, char *, int, int, struct target_ops *);
63 
64 static int return_zero (void);
65 
66 static int return_one (void);
67 
68 static int return_minus_one (void);
69 
70 void target_ignore (void);
71 
72 static void target_command (char *, int);
73 
74 static struct target_ops *find_default_run_target (char *);
75 
76 static void nosupport_runtime (void);
77 
78 static LONGEST default_xfer_partial (struct target_ops *ops,
79 				     enum target_object object,
80 				     const char *annex, gdb_byte *readbuf,
81 				     const gdb_byte *writebuf,
82 				     ULONGEST offset, LONGEST len);
83 
84 static LONGEST current_xfer_partial (struct target_ops *ops,
85 				     enum target_object object,
86 				     const char *annex, gdb_byte *readbuf,
87 				     const gdb_byte *writebuf,
88 				     ULONGEST offset, LONGEST len);
89 
90 static LONGEST target_xfer_partial (struct target_ops *ops,
91 				    enum target_object object,
92 				    const char *annex,
93 				    void *readbuf, const void *writebuf,
94 				    ULONGEST offset, LONGEST len);
95 
96 static struct gdbarch *default_thread_architecture (struct target_ops *ops,
97 						    ptid_t ptid);
98 
99 static void init_dummy_target (void);
100 
101 static struct target_ops debug_target;
102 
103 static void debug_to_open (char *, int);
104 
105 static void debug_to_prepare_to_store (struct regcache *);
106 
107 static void debug_to_files_info (struct target_ops *);
108 
109 static int debug_to_insert_breakpoint (struct gdbarch *,
110 				       struct bp_target_info *);
111 
112 static int debug_to_remove_breakpoint (struct gdbarch *,
113 				       struct bp_target_info *);
114 
115 static int debug_to_can_use_hw_breakpoint (int, int, int);
116 
117 static int debug_to_insert_hw_breakpoint (struct gdbarch *,
118 					  struct bp_target_info *);
119 
120 static int debug_to_remove_hw_breakpoint (struct gdbarch *,
121 					  struct bp_target_info *);
122 
123 static int debug_to_insert_watchpoint (CORE_ADDR, int, int);
124 
125 static int debug_to_remove_watchpoint (CORE_ADDR, int, int);
126 
127 static int debug_to_stopped_by_watchpoint (void);
128 
129 static int debug_to_stopped_data_address (struct target_ops *, CORE_ADDR *);
130 
131 static int debug_to_watchpoint_addr_within_range (struct target_ops *,
132 						  CORE_ADDR, CORE_ADDR, int);
133 
134 static int debug_to_region_ok_for_hw_watchpoint (CORE_ADDR, int);
135 
136 static void debug_to_terminal_init (void);
137 
138 static void debug_to_terminal_inferior (void);
139 
140 static void debug_to_terminal_ours_for_output (void);
141 
142 static void debug_to_terminal_save_ours (void);
143 
144 static void debug_to_terminal_ours (void);
145 
146 static void debug_to_terminal_info (char *, int);
147 
148 static void debug_to_load (char *, int);
149 
150 static int debug_to_lookup_symbol (char *, CORE_ADDR *);
151 
152 static int debug_to_can_run (void);
153 
154 static void debug_to_notice_signals (ptid_t);
155 
156 static void debug_to_stop (ptid_t);
157 
158 /* NOTE: cagney/2004-09-29: Many targets reference this variable in
159    wierd and mysterious ways.  Putting the variable here lets those
160    wierd and mysterious ways keep building while they are being
161    converted to the inferior inheritance structure.  */
162 struct target_ops deprecated_child_ops;
163 
164 /* Pointer to array of target architecture structures; the size of the
165    array; the current index into the array; the allocated size of the
166    array.  */
167 struct target_ops **target_structs;
168 unsigned target_struct_size;
169 unsigned target_struct_index;
170 unsigned target_struct_allocsize;
171 #define	DEFAULT_ALLOCSIZE	10
172 
173 /* The initial current target, so that there is always a semi-valid
174    current target.  */
175 
176 static struct target_ops dummy_target;
177 
178 /* Top of target stack.  */
179 
180 static struct target_ops *target_stack;
181 
182 /* The target structure we are currently using to talk to a process
183    or file or whatever "inferior" we have.  */
184 
185 struct target_ops current_target;
186 
187 /* Command list for target.  */
188 
189 static struct cmd_list_element *targetlist = NULL;
190 
191 /* Nonzero if we should trust readonly sections from the
192    executable when reading memory.  */
193 
194 static int trust_readonly = 0;
195 
196 /* Nonzero if we should show true memory content including
197    memory breakpoint inserted by gdb.  */
198 
199 static int show_memory_breakpoints = 0;
200 
201 /* Non-zero if we want to see trace of target level stuff.  */
202 
203 static int targetdebug = 0;
204 static void
205 show_targetdebug (struct ui_file *file, int from_tty,
206 		  struct cmd_list_element *c, const char *value)
207 {
208   fprintf_filtered (file, _("Target debugging is %s.\n"), value);
209 }
210 
211 static void setup_target_debug (void);
212 
213 /* The option sets this.  */
214 static int stack_cache_enabled_p_1 = 1;
215 /* And set_stack_cache_enabled_p updates this.
216    The reason for the separation is so that we don't flush the cache for
217    on->on transitions.  */
218 static int stack_cache_enabled_p = 1;
219 
220 /* This is called *after* the stack-cache has been set.
221    Flush the cache for off->on and on->off transitions.
222    There's no real need to flush the cache for on->off transitions,
223    except cleanliness.  */
224 
225 static void
226 set_stack_cache_enabled_p (char *args, int from_tty,
227 			   struct cmd_list_element *c)
228 {
229   if (stack_cache_enabled_p != stack_cache_enabled_p_1)
230     target_dcache_invalidate ();
231 
232   stack_cache_enabled_p = stack_cache_enabled_p_1;
233 }
234 
235 static void
236 show_stack_cache_enabled_p (struct ui_file *file, int from_tty,
237 			    struct cmd_list_element *c, const char *value)
238 {
239   fprintf_filtered (file, _("Cache use for stack accesses is %s.\n"), value);
240 }
241 
242 /* Cache of memory operations, to speed up remote access.  */
243 static DCACHE *target_dcache;
244 
245 /* Invalidate the target dcache.  */
246 
247 void
248 target_dcache_invalidate (void)
249 {
250   dcache_invalidate (target_dcache);
251 }
252 
253 /* The user just typed 'target' without the name of a target.  */
254 
255 static void
256 target_command (char *arg, int from_tty)
257 {
258   fputs_filtered ("Argument required (target name).  Try `help target'\n",
259 		  gdb_stdout);
260 }
261 
262 /* Default target_has_* methods for process_stratum targets.  */
263 
264 int
265 default_child_has_all_memory (struct target_ops *ops)
266 {
267   /* If no inferior selected, then we can't read memory here.  */
268   if (ptid_equal (inferior_ptid, null_ptid))
269     return 0;
270 
271   return 1;
272 }
273 
274 int
275 default_child_has_memory (struct target_ops *ops)
276 {
277   /* If no inferior selected, then we can't read memory here.  */
278   if (ptid_equal (inferior_ptid, null_ptid))
279     return 0;
280 
281   return 1;
282 }
283 
284 int
285 default_child_has_stack (struct target_ops *ops)
286 {
287   /* If no inferior selected, there's no stack.  */
288   if (ptid_equal (inferior_ptid, null_ptid))
289     return 0;
290 
291   return 1;
292 }
293 
294 int
295 default_child_has_registers (struct target_ops *ops)
296 {
297   /* Can't read registers from no inferior.  */
298   if (ptid_equal (inferior_ptid, null_ptid))
299     return 0;
300 
301   return 1;
302 }
303 
304 int
305 default_child_has_execution (struct target_ops *ops)
306 {
307   /* If there's no thread selected, then we can't make it run through
308      hoops.  */
309   if (ptid_equal (inferior_ptid, null_ptid))
310     return 0;
311 
312   return 1;
313 }
314 
315 
316 int
317 target_has_all_memory_1 (void)
318 {
319   struct target_ops *t;
320 
321   for (t = current_target.beneath; t != NULL; t = t->beneath)
322     if (t->to_has_all_memory (t))
323       return 1;
324 
325   return 0;
326 }
327 
328 int
329 target_has_memory_1 (void)
330 {
331   struct target_ops *t;
332 
333   for (t = current_target.beneath; t != NULL; t = t->beneath)
334     if (t->to_has_memory (t))
335       return 1;
336 
337   return 0;
338 }
339 
340 int
341 target_has_stack_1 (void)
342 {
343   struct target_ops *t;
344 
345   for (t = current_target.beneath; t != NULL; t = t->beneath)
346     if (t->to_has_stack (t))
347       return 1;
348 
349   return 0;
350 }
351 
352 int
353 target_has_registers_1 (void)
354 {
355   struct target_ops *t;
356 
357   for (t = current_target.beneath; t != NULL; t = t->beneath)
358     if (t->to_has_registers (t))
359       return 1;
360 
361   return 0;
362 }
363 
364 int
365 target_has_execution_1 (void)
366 {
367   struct target_ops *t;
368 
369   for (t = current_target.beneath; t != NULL; t = t->beneath)
370     if (t->to_has_execution (t))
371       return 1;
372 
373   return 0;
374 }
375 
376 /* Add a possible target architecture to the list.  */
377 
378 void
379 add_target (struct target_ops *t)
380 {
381   /* Provide default values for all "must have" methods.  */
382   if (t->to_xfer_partial == NULL)
383     t->to_xfer_partial = default_xfer_partial;
384 
385   if (t->to_has_all_memory == NULL)
386     t->to_has_all_memory = (int (*) (struct target_ops *)) return_zero;
387 
388   if (t->to_has_memory == NULL)
389     t->to_has_memory = (int (*) (struct target_ops *)) return_zero;
390 
391   if (t->to_has_stack == NULL)
392     t->to_has_stack = (int (*) (struct target_ops *)) return_zero;
393 
394   if (t->to_has_registers == NULL)
395     t->to_has_registers = (int (*) (struct target_ops *)) return_zero;
396 
397   if (t->to_has_execution == NULL)
398     t->to_has_execution = (int (*) (struct target_ops *)) return_zero;
399 
400   if (!target_structs)
401     {
402       target_struct_allocsize = DEFAULT_ALLOCSIZE;
403       target_structs = (struct target_ops **) xmalloc
404 	(target_struct_allocsize * sizeof (*target_structs));
405     }
406   if (target_struct_size >= target_struct_allocsize)
407     {
408       target_struct_allocsize *= 2;
409       target_structs = (struct target_ops **)
410 	xrealloc ((char *) target_structs,
411 		  target_struct_allocsize * sizeof (*target_structs));
412     }
413   target_structs[target_struct_size++] = t;
414 
415   if (targetlist == NULL)
416     add_prefix_cmd ("target", class_run, target_command, _("\
417 Connect to a target machine or process.\n\
418 The first argument is the type or protocol of the target machine.\n\
419 Remaining arguments are interpreted by the target protocol.  For more\n\
420 information on the arguments for a particular protocol, type\n\
421 `help target ' followed by the protocol name."),
422 		    &targetlist, "target ", 0, &cmdlist);
423   add_cmd (t->to_shortname, no_class, t->to_open, t->to_doc, &targetlist);
424 }
425 
426 /* Stub functions */
427 
428 void
429 target_ignore (void)
430 {
431 }
432 
433 void
434 target_kill (void)
435 {
436   struct target_ops *t;
437 
438   for (t = current_target.beneath; t != NULL; t = t->beneath)
439     if (t->to_kill != NULL)
440       {
441 	if (targetdebug)
442 	  fprintf_unfiltered (gdb_stdlog, "target_kill ()\n");
443 
444         t->to_kill (t);
445 	return;
446       }
447 
448   noprocess ();
449 }
450 
451 void
452 target_load (char *arg, int from_tty)
453 {
454   target_dcache_invalidate ();
455   (*current_target.to_load) (arg, from_tty);
456 }
457 
458 void
459 target_create_inferior (char *exec_file, char *args,
460 			char **env, int from_tty)
461 {
462   struct target_ops *t;
463   for (t = current_target.beneath; t != NULL; t = t->beneath)
464     {
465       if (t->to_create_inferior != NULL)
466 	{
467 	  t->to_create_inferior (t, exec_file, args, env, from_tty);
468 	  if (targetdebug)
469 	    fprintf_unfiltered (gdb_stdlog,
470 				"target_create_inferior (%s, %s, xxx, %d)\n",
471 				exec_file, args, from_tty);
472 	  return;
473 	}
474     }
475 
476   internal_error (__FILE__, __LINE__,
477 		  "could not find a target to create inferior");
478 }
479 
480 void
481 target_terminal_inferior (void)
482 {
483   /* A background resume (``run&'') should leave GDB in control of the
484      terminal.  */
485   if (target_is_async_p () && !sync_execution)
486     return;
487 
488   /* If GDB is resuming the inferior in the foreground, install
489      inferior's terminal modes.  */
490   (*current_target.to_terminal_inferior) ();
491 }
492 
493 static int
494 nomemory (CORE_ADDR memaddr, char *myaddr, int len, int write,
495 	  struct target_ops *t)
496 {
497   errno = EIO;			/* Can't read/write this location */
498   return 0;			/* No bytes handled */
499 }
500 
501 static void
502 tcomplain (void)
503 {
504   error (_("You can't do that when your target is `%s'"),
505 	 current_target.to_shortname);
506 }
507 
508 void
509 noprocess (void)
510 {
511   error (_("You can't do that without a process to debug."));
512 }
513 
514 static int
515 nosymbol (char *name, CORE_ADDR *addrp)
516 {
517   return 1;			/* Symbol does not exist in target env */
518 }
519 
520 static void
521 nosupport_runtime (void)
522 {
523   if (ptid_equal (inferior_ptid, null_ptid))
524     noprocess ();
525   else
526     error (_("No run-time support for this"));
527 }
528 
529 
530 static void
531 default_terminal_info (char *args, int from_tty)
532 {
533   printf_unfiltered (_("No saved terminal information.\n"));
534 }
535 
536 /* This is the default target_create_inferior and target_attach function.
537    If the current target is executing, it asks whether to kill it off.
538    If this function returns without calling error(), it has killed off
539    the target, and the operation should be attempted.  */
540 
541 static void
542 kill_or_be_killed (int from_tty)
543 {
544   if (target_has_execution)
545     {
546       printf_unfiltered (_("You are already running a program:\n"));
547       target_files_info ();
548       if (query (_("Kill it? ")))
549 	{
550 	  target_kill ();
551 	  if (target_has_execution)
552 	    error (_("Killing the program did not help."));
553 	  return;
554 	}
555       else
556 	{
557 	  error (_("Program not killed."));
558 	}
559     }
560   tcomplain ();
561 }
562 
563 /* A default implementation for the to_get_ada_task_ptid target method.
564 
565    This function builds the PTID by using both LWP and TID as part of
566    the PTID lwp and tid elements.  The pid used is the pid of the
567    inferior_ptid.  */
568 
569 static ptid_t
570 default_get_ada_task_ptid (long lwp, long tid)
571 {
572   return ptid_build (ptid_get_pid (inferior_ptid), lwp, tid);
573 }
574 
575 /* Go through the target stack from top to bottom, copying over zero
576    entries in current_target, then filling in still empty entries.  In
577    effect, we are doing class inheritance through the pushed target
578    vectors.
579 
580    NOTE: cagney/2003-10-17: The problem with this inheritance, as it
581    is currently implemented, is that it discards any knowledge of
582    which target an inherited method originally belonged to.
583    Consequently, new new target methods should instead explicitly and
584    locally search the target stack for the target that can handle the
585    request.  */
586 
587 static void
588 update_current_target (void)
589 {
590   struct target_ops *t;
591 
592   /* First, reset current's contents.  */
593   memset (&current_target, 0, sizeof (current_target));
594 
595 #define INHERIT(FIELD, TARGET) \
596       if (!current_target.FIELD) \
597 	current_target.FIELD = (TARGET)->FIELD
598 
599   for (t = target_stack; t; t = t->beneath)
600     {
601       INHERIT (to_shortname, t);
602       INHERIT (to_longname, t);
603       INHERIT (to_doc, t);
604       /* Do not inherit to_open.  */
605       /* Do not inherit to_close.  */
606       /* Do not inherit to_attach.  */
607       INHERIT (to_post_attach, t);
608       INHERIT (to_attach_no_wait, t);
609       /* Do not inherit to_detach.  */
610       /* Do not inherit to_disconnect.  */
611       /* Do not inherit to_resume.  */
612       /* Do not inherit to_wait.  */
613       /* Do not inherit to_fetch_registers.  */
614       /* Do not inherit to_store_registers.  */
615       INHERIT (to_prepare_to_store, t);
616       INHERIT (deprecated_xfer_memory, t);
617       INHERIT (to_files_info, t);
618       INHERIT (to_insert_breakpoint, t);
619       INHERIT (to_remove_breakpoint, t);
620       INHERIT (to_can_use_hw_breakpoint, t);
621       INHERIT (to_insert_hw_breakpoint, t);
622       INHERIT (to_remove_hw_breakpoint, t);
623       INHERIT (to_insert_watchpoint, t);
624       INHERIT (to_remove_watchpoint, t);
625       INHERIT (to_stopped_data_address, t);
626       INHERIT (to_have_steppable_watchpoint, t);
627       INHERIT (to_have_continuable_watchpoint, t);
628       INHERIT (to_stopped_by_watchpoint, t);
629       INHERIT (to_watchpoint_addr_within_range, t);
630       INHERIT (to_region_ok_for_hw_watchpoint, t);
631       INHERIT (to_terminal_init, t);
632       INHERIT (to_terminal_inferior, t);
633       INHERIT (to_terminal_ours_for_output, t);
634       INHERIT (to_terminal_ours, t);
635       INHERIT (to_terminal_save_ours, t);
636       INHERIT (to_terminal_info, t);
637       /* Do not inherit to_kill.  */
638       INHERIT (to_load, t);
639       INHERIT (to_lookup_symbol, t);
640       /* Do no inherit to_create_inferior.  */
641       INHERIT (to_post_startup_inferior, t);
642       INHERIT (to_acknowledge_created_inferior, t);
643       INHERIT (to_insert_fork_catchpoint, t);
644       INHERIT (to_remove_fork_catchpoint, t);
645       INHERIT (to_insert_vfork_catchpoint, t);
646       INHERIT (to_remove_vfork_catchpoint, t);
647       /* Do not inherit to_follow_fork.  */
648       INHERIT (to_insert_exec_catchpoint, t);
649       INHERIT (to_remove_exec_catchpoint, t);
650       INHERIT (to_set_syscall_catchpoint, t);
651       INHERIT (to_has_exited, t);
652       /* Do not inherit to_mourn_inferiour.  */
653       INHERIT (to_can_run, t);
654       INHERIT (to_notice_signals, t);
655       /* Do not inherit to_thread_alive.  */
656       /* Do not inherit to_find_new_threads.  */
657       /* Do not inherit to_pid_to_str.  */
658       INHERIT (to_extra_thread_info, t);
659       INHERIT (to_stop, t);
660       /* Do not inherit to_xfer_partial.  */
661       INHERIT (to_rcmd, t);
662       INHERIT (to_pid_to_exec_file, t);
663       INHERIT (to_log_command, t);
664       INHERIT (to_stratum, t);
665       /* Do not inherit to_has_all_memory */
666       /* Do not inherit to_has_memory */
667       /* Do not inherit to_has_stack */
668       /* Do not inherit to_has_registers */
669       /* Do not inherit to_has_execution */
670       INHERIT (to_has_thread_control, t);
671       INHERIT (to_can_async_p, t);
672       INHERIT (to_is_async_p, t);
673       INHERIT (to_async, t);
674       INHERIT (to_async_mask, t);
675       INHERIT (to_find_memory_regions, t);
676       INHERIT (to_make_corefile_notes, t);
677       /* Do not inherit to_get_thread_local_address.  */
678       INHERIT (to_can_execute_reverse, t);
679       INHERIT (to_thread_architecture, t);
680       /* Do not inherit to_read_description.  */
681       INHERIT (to_get_ada_task_ptid, t);
682       /* Do not inherit to_search_memory.  */
683       INHERIT (to_supports_multi_process, t);
684       INHERIT (to_magic, t);
685       /* Do not inherit to_memory_map.  */
686       /* Do not inherit to_flash_erase.  */
687       /* Do not inherit to_flash_done.  */
688     }
689 #undef INHERIT
690 
691   /* Clean up a target struct so it no longer has any zero pointers in
692      it.  Some entries are defaulted to a method that print an error,
693      others are hard-wired to a standard recursive default.  */
694 
695 #define de_fault(field, value) \
696   if (!current_target.field)               \
697     current_target.field = value
698 
699   de_fault (to_open,
700 	    (void (*) (char *, int))
701 	    tcomplain);
702   de_fault (to_close,
703 	    (void (*) (int))
704 	    target_ignore);
705   de_fault (to_post_attach,
706 	    (void (*) (int))
707 	    target_ignore);
708   de_fault (to_prepare_to_store,
709 	    (void (*) (struct regcache *))
710 	    noprocess);
711   de_fault (deprecated_xfer_memory,
712 	    (int (*) (CORE_ADDR, gdb_byte *, int, int, struct mem_attrib *, struct target_ops *))
713 	    nomemory);
714   de_fault (to_files_info,
715 	    (void (*) (struct target_ops *))
716 	    target_ignore);
717   de_fault (to_insert_breakpoint,
718 	    memory_insert_breakpoint);
719   de_fault (to_remove_breakpoint,
720 	    memory_remove_breakpoint);
721   de_fault (to_can_use_hw_breakpoint,
722 	    (int (*) (int, int, int))
723 	    return_zero);
724   de_fault (to_insert_hw_breakpoint,
725 	    (int (*) (struct gdbarch *, struct bp_target_info *))
726 	    return_minus_one);
727   de_fault (to_remove_hw_breakpoint,
728 	    (int (*) (struct gdbarch *, struct bp_target_info *))
729 	    return_minus_one);
730   de_fault (to_insert_watchpoint,
731 	    (int (*) (CORE_ADDR, int, int))
732 	    return_minus_one);
733   de_fault (to_remove_watchpoint,
734 	    (int (*) (CORE_ADDR, int, int))
735 	    return_minus_one);
736   de_fault (to_stopped_by_watchpoint,
737 	    (int (*) (void))
738 	    return_zero);
739   de_fault (to_stopped_data_address,
740 	    (int (*) (struct target_ops *, CORE_ADDR *))
741 	    return_zero);
742   de_fault (to_watchpoint_addr_within_range,
743 	    default_watchpoint_addr_within_range);
744   de_fault (to_region_ok_for_hw_watchpoint,
745 	    default_region_ok_for_hw_watchpoint);
746   de_fault (to_terminal_init,
747 	    (void (*) (void))
748 	    target_ignore);
749   de_fault (to_terminal_inferior,
750 	    (void (*) (void))
751 	    target_ignore);
752   de_fault (to_terminal_ours_for_output,
753 	    (void (*) (void))
754 	    target_ignore);
755   de_fault (to_terminal_ours,
756 	    (void (*) (void))
757 	    target_ignore);
758   de_fault (to_terminal_save_ours,
759 	    (void (*) (void))
760 	    target_ignore);
761   de_fault (to_terminal_info,
762 	    default_terminal_info);
763   de_fault (to_load,
764 	    (void (*) (char *, int))
765 	    tcomplain);
766   de_fault (to_lookup_symbol,
767 	    (int (*) (char *, CORE_ADDR *))
768 	    nosymbol);
769   de_fault (to_post_startup_inferior,
770 	    (void (*) (ptid_t))
771 	    target_ignore);
772   de_fault (to_acknowledge_created_inferior,
773 	    (void (*) (int))
774 	    target_ignore);
775   de_fault (to_insert_fork_catchpoint,
776 	    (void (*) (int))
777 	    tcomplain);
778   de_fault (to_remove_fork_catchpoint,
779 	    (int (*) (int))
780 	    tcomplain);
781   de_fault (to_insert_vfork_catchpoint,
782 	    (void (*) (int))
783 	    tcomplain);
784   de_fault (to_remove_vfork_catchpoint,
785 	    (int (*) (int))
786 	    tcomplain);
787   de_fault (to_insert_exec_catchpoint,
788 	    (void (*) (int))
789 	    tcomplain);
790   de_fault (to_remove_exec_catchpoint,
791 	    (int (*) (int))
792 	    tcomplain);
793   de_fault (to_set_syscall_catchpoint,
794 	    (int (*) (int, int, int, int, int *))
795 	    tcomplain);
796   de_fault (to_has_exited,
797 	    (int (*) (int, int, int *))
798 	    return_zero);
799   de_fault (to_can_run,
800 	    return_zero);
801   de_fault (to_notice_signals,
802 	    (void (*) (ptid_t))
803 	    target_ignore);
804   de_fault (to_extra_thread_info,
805 	    (char *(*) (struct thread_info *))
806 	    return_zero);
807   de_fault (to_stop,
808 	    (void (*) (ptid_t))
809 	    target_ignore);
810   current_target.to_xfer_partial = current_xfer_partial;
811   de_fault (to_rcmd,
812 	    (void (*) (char *, struct ui_file *))
813 	    tcomplain);
814   de_fault (to_pid_to_exec_file,
815 	    (char *(*) (int))
816 	    return_zero);
817   de_fault (to_async,
818 	    (void (*) (void (*) (enum inferior_event_type, void*), void*))
819 	    tcomplain);
820   de_fault (to_async_mask,
821 	    (int (*) (int))
822 	    return_one);
823   de_fault (to_thread_architecture,
824 	    default_thread_architecture);
825   current_target.to_read_description = NULL;
826   de_fault (to_get_ada_task_ptid,
827             (ptid_t (*) (long, long))
828             default_get_ada_task_ptid);
829   de_fault (to_supports_multi_process,
830 	    (int (*) (void))
831 	    return_zero);
832 #undef de_fault
833 
834   /* Finally, position the target-stack beneath the squashed
835      "current_target".  That way code looking for a non-inherited
836      target method can quickly and simply find it.  */
837   current_target.beneath = target_stack;
838 
839   if (targetdebug)
840     setup_target_debug ();
841 }
842 
843 /* Push a new target type into the stack of the existing target accessors,
844    possibly superseding some of the existing accessors.
845 
846    Result is zero if the pushed target ended up on top of the stack,
847    nonzero if at least one target is on top of it.
848 
849    Rather than allow an empty stack, we always have the dummy target at
850    the bottom stratum, so we can call the function vectors without
851    checking them.  */
852 
853 int
854 push_target (struct target_ops *t)
855 {
856   struct target_ops **cur;
857 
858   /* Check magic number.  If wrong, it probably means someone changed
859      the struct definition, but not all the places that initialize one.  */
860   if (t->to_magic != OPS_MAGIC)
861     {
862       fprintf_unfiltered (gdb_stderr,
863 			  "Magic number of %s target struct wrong\n",
864 			  t->to_shortname);
865       internal_error (__FILE__, __LINE__, _("failed internal consistency check"));
866     }
867 
868   /* Find the proper stratum to install this target in.  */
869   for (cur = &target_stack; (*cur) != NULL; cur = &(*cur)->beneath)
870     {
871       if ((int) (t->to_stratum) >= (int) (*cur)->to_stratum)
872 	break;
873     }
874 
875   /* If there's already targets at this stratum, remove them.  */
876   /* FIXME: cagney/2003-10-15: I think this should be popping all
877      targets to CUR, and not just those at this stratum level.  */
878   while ((*cur) != NULL && t->to_stratum == (*cur)->to_stratum)
879     {
880       /* There's already something at this stratum level.  Close it,
881          and un-hook it from the stack.  */
882       struct target_ops *tmp = (*cur);
883       (*cur) = (*cur)->beneath;
884       tmp->beneath = NULL;
885       target_close (tmp, 0);
886     }
887 
888   /* We have removed all targets in our stratum, now add the new one.  */
889   t->beneath = (*cur);
890   (*cur) = t;
891 
892   update_current_target ();
893 
894   /* Not on top?  */
895   return (t != target_stack);
896 }
897 
898 /* Remove a target_ops vector from the stack, wherever it may be.
899    Return how many times it was removed (0 or 1).  */
900 
901 int
902 unpush_target (struct target_ops *t)
903 {
904   struct target_ops **cur;
905   struct target_ops *tmp;
906 
907   if (t->to_stratum == dummy_stratum)
908     internal_error (__FILE__, __LINE__,
909 		    "Attempt to unpush the dummy target");
910 
911   /* Look for the specified target.  Note that we assume that a target
912      can only occur once in the target stack. */
913 
914   for (cur = &target_stack; (*cur) != NULL; cur = &(*cur)->beneath)
915     {
916       if ((*cur) == t)
917 	break;
918     }
919 
920   if ((*cur) == NULL)
921     return 0;			/* Didn't find target_ops, quit now */
922 
923   /* NOTE: cagney/2003-12-06: In '94 the close call was made
924      unconditional by moving it to before the above check that the
925      target was in the target stack (something about "Change the way
926      pushing and popping of targets work to support target overlays
927      and inheritance").  This doesn't make much sense - only open
928      targets should be closed.  */
929   target_close (t, 0);
930 
931   /* Unchain the target */
932   tmp = (*cur);
933   (*cur) = (*cur)->beneath;
934   tmp->beneath = NULL;
935 
936   update_current_target ();
937 
938   return 1;
939 }
940 
941 void
942 pop_target (void)
943 {
944   target_close (target_stack, 0);	/* Let it clean up */
945   if (unpush_target (target_stack) == 1)
946     return;
947 
948   fprintf_unfiltered (gdb_stderr,
949 		      "pop_target couldn't find target %s\n",
950 		      current_target.to_shortname);
951   internal_error (__FILE__, __LINE__, _("failed internal consistency check"));
952 }
953 
954 void
955 pop_all_targets_above (enum strata above_stratum, int quitting)
956 {
957   while ((int) (current_target.to_stratum) > (int) above_stratum)
958     {
959       target_close (target_stack, quitting);
960       if (!unpush_target (target_stack))
961 	{
962 	  fprintf_unfiltered (gdb_stderr,
963 			      "pop_all_targets couldn't find target %s\n",
964 			      target_stack->to_shortname);
965 	  internal_error (__FILE__, __LINE__,
966 			  _("failed internal consistency check"));
967 	  break;
968 	}
969     }
970 }
971 
972 void
973 pop_all_targets (int quitting)
974 {
975   pop_all_targets_above (dummy_stratum, quitting);
976 }
977 
978 /* Using the objfile specified in OBJFILE, find the address for the
979    current thread's thread-local storage with offset OFFSET.  */
980 CORE_ADDR
981 target_translate_tls_address (struct objfile *objfile, CORE_ADDR offset)
982 {
983   volatile CORE_ADDR addr = 0;
984   struct target_ops *target;
985 
986   for (target = current_target.beneath;
987        target != NULL;
988        target = target->beneath)
989     {
990       if (target->to_get_thread_local_address != NULL)
991 	break;
992     }
993 
994   if (target != NULL
995       && gdbarch_fetch_tls_load_module_address_p (target_gdbarch))
996     {
997       ptid_t ptid = inferior_ptid;
998       volatile struct gdb_exception ex;
999 
1000       TRY_CATCH (ex, RETURN_MASK_ALL)
1001 	{
1002 	  CORE_ADDR lm_addr;
1003 
1004 	  /* Fetch the load module address for this objfile.  */
1005 	  lm_addr = gdbarch_fetch_tls_load_module_address (target_gdbarch,
1006 	                                                   objfile);
1007 	  /* If it's 0, throw the appropriate exception.  */
1008 	  if (lm_addr == 0)
1009 	    throw_error (TLS_LOAD_MODULE_NOT_FOUND_ERROR,
1010 			 _("TLS load module not found"));
1011 
1012 	  addr = target->to_get_thread_local_address (target, ptid, lm_addr, offset);
1013 	}
1014       /* If an error occurred, print TLS related messages here.  Otherwise,
1015          throw the error to some higher catcher.  */
1016       if (ex.reason < 0)
1017 	{
1018 	  int objfile_is_library = (objfile->flags & OBJF_SHARED);
1019 
1020 	  switch (ex.error)
1021 	    {
1022 	    case TLS_NO_LIBRARY_SUPPORT_ERROR:
1023 	      error (_("Cannot find thread-local variables in this thread library."));
1024 	      break;
1025 	    case TLS_LOAD_MODULE_NOT_FOUND_ERROR:
1026 	      if (objfile_is_library)
1027 		error (_("Cannot find shared library `%s' in dynamic"
1028 		         " linker's load module list"), objfile->name);
1029 	      else
1030 		error (_("Cannot find executable file `%s' in dynamic"
1031 		         " linker's load module list"), objfile->name);
1032 	      break;
1033 	    case TLS_NOT_ALLOCATED_YET_ERROR:
1034 	      if (objfile_is_library)
1035 		error (_("The inferior has not yet allocated storage for"
1036 		         " thread-local variables in\n"
1037 		         "the shared library `%s'\n"
1038 		         "for %s"),
1039 		       objfile->name, target_pid_to_str (ptid));
1040 	      else
1041 		error (_("The inferior has not yet allocated storage for"
1042 		         " thread-local variables in\n"
1043 		         "the executable `%s'\n"
1044 		         "for %s"),
1045 		       objfile->name, target_pid_to_str (ptid));
1046 	      break;
1047 	    case TLS_GENERIC_ERROR:
1048 	      if (objfile_is_library)
1049 		error (_("Cannot find thread-local storage for %s, "
1050 		         "shared library %s:\n%s"),
1051 		       target_pid_to_str (ptid),
1052 		       objfile->name, ex.message);
1053 	      else
1054 		error (_("Cannot find thread-local storage for %s, "
1055 		         "executable file %s:\n%s"),
1056 		       target_pid_to_str (ptid),
1057 		       objfile->name, ex.message);
1058 	      break;
1059 	    default:
1060 	      throw_exception (ex);
1061 	      break;
1062 	    }
1063 	}
1064     }
1065   /* It wouldn't be wrong here to try a gdbarch method, too; finding
1066      TLS is an ABI-specific thing.  But we don't do that yet.  */
1067   else
1068     error (_("Cannot find thread-local variables on this target"));
1069 
1070   return addr;
1071 }
1072 
1073 #undef	MIN
1074 #define MIN(A, B) (((A) <= (B)) ? (A) : (B))
1075 
1076 /* target_read_string -- read a null terminated string, up to LEN bytes,
1077    from MEMADDR in target.  Set *ERRNOP to the errno code, or 0 if successful.
1078    Set *STRING to a pointer to malloc'd memory containing the data; the caller
1079    is responsible for freeing it.  Return the number of bytes successfully
1080    read.  */
1081 
1082 int
1083 target_read_string (CORE_ADDR memaddr, char **string, int len, int *errnop)
1084 {
1085   int tlen, origlen, offset, i;
1086   gdb_byte buf[4];
1087   int errcode = 0;
1088   char *buffer;
1089   int buffer_allocated;
1090   char *bufptr;
1091   unsigned int nbytes_read = 0;
1092 
1093   gdb_assert (string);
1094 
1095   /* Small for testing.  */
1096   buffer_allocated = 4;
1097   buffer = xmalloc (buffer_allocated);
1098   bufptr = buffer;
1099 
1100   origlen = len;
1101 
1102   while (len > 0)
1103     {
1104       tlen = MIN (len, 4 - (memaddr & 3));
1105       offset = memaddr & 3;
1106 
1107       errcode = target_read_memory (memaddr & ~3, buf, sizeof buf);
1108       if (errcode != 0)
1109 	{
1110 	  /* The transfer request might have crossed the boundary to an
1111 	     unallocated region of memory. Retry the transfer, requesting
1112 	     a single byte.  */
1113 	  tlen = 1;
1114 	  offset = 0;
1115 	  errcode = target_read_memory (memaddr, buf, 1);
1116 	  if (errcode != 0)
1117 	    goto done;
1118 	}
1119 
1120       if (bufptr - buffer + tlen > buffer_allocated)
1121 	{
1122 	  unsigned int bytes;
1123 	  bytes = bufptr - buffer;
1124 	  buffer_allocated *= 2;
1125 	  buffer = xrealloc (buffer, buffer_allocated);
1126 	  bufptr = buffer + bytes;
1127 	}
1128 
1129       for (i = 0; i < tlen; i++)
1130 	{
1131 	  *bufptr++ = buf[i + offset];
1132 	  if (buf[i + offset] == '\000')
1133 	    {
1134 	      nbytes_read += i + 1;
1135 	      goto done;
1136 	    }
1137 	}
1138 
1139       memaddr += tlen;
1140       len -= tlen;
1141       nbytes_read += tlen;
1142     }
1143 done:
1144   *string = buffer;
1145   if (errnop != NULL)
1146     *errnop = errcode;
1147   return nbytes_read;
1148 }
1149 
1150 struct target_section_table *
1151 target_get_section_table (struct target_ops *target)
1152 {
1153   struct target_ops *t;
1154 
1155   if (targetdebug)
1156     fprintf_unfiltered (gdb_stdlog, "target_get_section_table ()\n");
1157 
1158   for (t = target; t != NULL; t = t->beneath)
1159     if (t->to_get_section_table != NULL)
1160       return (*t->to_get_section_table) (t);
1161 
1162   return NULL;
1163 }
1164 
1165 /* Find a section containing ADDR.  */
1166 
1167 struct target_section *
1168 target_section_by_addr (struct target_ops *target, CORE_ADDR addr)
1169 {
1170   struct target_section_table *table = target_get_section_table (target);
1171   struct target_section *secp;
1172 
1173   if (table == NULL)
1174     return NULL;
1175 
1176   for (secp = table->sections; secp < table->sections_end; secp++)
1177     {
1178       if (addr >= secp->addr && addr < secp->endaddr)
1179 	return secp;
1180     }
1181   return NULL;
1182 }
1183 
1184 /* Perform a partial memory transfer.  The arguments and return
1185    value are just as for target_xfer_partial.  */
1186 
1187 static LONGEST
1188 memory_xfer_partial (struct target_ops *ops, enum target_object object,
1189 		     void *readbuf, const void *writebuf, ULONGEST memaddr,
1190 		     LONGEST len)
1191 {
1192   LONGEST res;
1193   int reg_len;
1194   struct mem_region *region;
1195   struct inferior *inf;
1196 
1197   /* Zero length requests are ok and require no work.  */
1198   if (len == 0)
1199     return 0;
1200 
1201   /* For accesses to unmapped overlay sections, read directly from
1202      files.  Must do this first, as MEMADDR may need adjustment.  */
1203   if (readbuf != NULL && overlay_debugging)
1204     {
1205       struct obj_section *section = find_pc_overlay (memaddr);
1206       if (pc_in_unmapped_range (memaddr, section))
1207 	{
1208 	  struct target_section_table *table
1209 	    = target_get_section_table (ops);
1210 	  const char *section_name = section->the_bfd_section->name;
1211 	  memaddr = overlay_mapped_address (memaddr, section);
1212 	  return section_table_xfer_memory_partial (readbuf, writebuf,
1213 						    memaddr, len,
1214 						    table->sections,
1215 						    table->sections_end,
1216 						    section_name);
1217 	}
1218     }
1219 
1220   /* Try the executable files, if "trust-readonly-sections" is set.  */
1221   if (readbuf != NULL && trust_readonly)
1222     {
1223       struct target_section *secp;
1224       struct target_section_table *table;
1225 
1226       secp = target_section_by_addr (ops, memaddr);
1227       if (secp != NULL
1228 	  && (bfd_get_section_flags (secp->bfd, secp->the_bfd_section)
1229 	      & SEC_READONLY))
1230 	{
1231 	  table = target_get_section_table (ops);
1232 	  return section_table_xfer_memory_partial (readbuf, writebuf,
1233 						    memaddr, len,
1234 						    table->sections,
1235 						    table->sections_end,
1236 						    NULL);
1237 	}
1238     }
1239 
1240   /* Try GDB's internal data cache.  */
1241   region = lookup_mem_region (memaddr);
1242   /* region->hi == 0 means there's no upper bound.  */
1243   if (memaddr + len < region->hi || region->hi == 0)
1244     reg_len = len;
1245   else
1246     reg_len = region->hi - memaddr;
1247 
1248   switch (region->attrib.mode)
1249     {
1250     case MEM_RO:
1251       if (writebuf != NULL)
1252 	return -1;
1253       break;
1254 
1255     case MEM_WO:
1256       if (readbuf != NULL)
1257 	return -1;
1258       break;
1259 
1260     case MEM_FLASH:
1261       /* We only support writing to flash during "load" for now.  */
1262       if (writebuf != NULL)
1263 	error (_("Writing to flash memory forbidden in this context"));
1264       break;
1265 
1266     case MEM_NONE:
1267       return -1;
1268     }
1269 
1270   inf = find_inferior_pid (ptid_get_pid (inferior_ptid));
1271 
1272   if (inf != NULL
1273       && (region->attrib.cache
1274 	  || (stack_cache_enabled_p && object == TARGET_OBJECT_STACK_MEMORY)))
1275     {
1276       if (readbuf != NULL)
1277 	res = dcache_xfer_memory (ops, target_dcache, memaddr, readbuf,
1278 				  reg_len, 0);
1279       else
1280 	/* FIXME drow/2006-08-09: If we're going to preserve const
1281 	   correctness dcache_xfer_memory should take readbuf and
1282 	   writebuf.  */
1283 	res = dcache_xfer_memory (ops, target_dcache, memaddr,
1284 				  (void *) writebuf,
1285 				  reg_len, 1);
1286       if (res <= 0)
1287 	return -1;
1288       else
1289 	{
1290 	  if (readbuf && !show_memory_breakpoints)
1291 	    breakpoint_restore_shadows (readbuf, memaddr, reg_len);
1292 	  return res;
1293 	}
1294     }
1295 
1296   /* If none of those methods found the memory we wanted, fall back
1297      to a target partial transfer.  Normally a single call to
1298      to_xfer_partial is enough; if it doesn't recognize an object
1299      it will call the to_xfer_partial of the next target down.
1300      But for memory this won't do.  Memory is the only target
1301      object which can be read from more than one valid target.
1302      A core file, for instance, could have some of memory but
1303      delegate other bits to the target below it.  So, we must
1304      manually try all targets.  */
1305 
1306   do
1307     {
1308       res = ops->to_xfer_partial (ops, TARGET_OBJECT_MEMORY, NULL,
1309 				  readbuf, writebuf, memaddr, reg_len);
1310       if (res > 0)
1311 	break;
1312 
1313       /* We want to continue past core files to executables, but not
1314 	 past a running target's memory.  */
1315       if (ops->to_has_all_memory (ops))
1316 	break;
1317 
1318       ops = ops->beneath;
1319     }
1320   while (ops != NULL);
1321 
1322   if (readbuf && !show_memory_breakpoints)
1323     breakpoint_restore_shadows (readbuf, memaddr, reg_len);
1324 
1325   /* Make sure the cache gets updated no matter what - if we are writing
1326      to the stack.  Even if this write is not tagged as such, we still need
1327      to update the cache.  */
1328 
1329   if (res > 0
1330       && inf != NULL
1331       && writebuf != NULL
1332       && !region->attrib.cache
1333       && stack_cache_enabled_p
1334       && object != TARGET_OBJECT_STACK_MEMORY)
1335     {
1336       dcache_update (target_dcache, memaddr, (void *) writebuf, res);
1337     }
1338 
1339   /* If we still haven't got anything, return the last error.  We
1340      give up.  */
1341   return res;
1342 }
1343 
1344 static void
1345 restore_show_memory_breakpoints (void *arg)
1346 {
1347   show_memory_breakpoints = (uintptr_t) arg;
1348 }
1349 
1350 struct cleanup *
1351 make_show_memory_breakpoints_cleanup (int show)
1352 {
1353   int current = show_memory_breakpoints;
1354   show_memory_breakpoints = show;
1355 
1356   return make_cleanup (restore_show_memory_breakpoints,
1357 		       (void *) (uintptr_t) current);
1358 }
1359 
1360 static LONGEST
1361 target_xfer_partial (struct target_ops *ops,
1362 		     enum target_object object, const char *annex,
1363 		     void *readbuf, const void *writebuf,
1364 		     ULONGEST offset, LONGEST len)
1365 {
1366   LONGEST retval;
1367 
1368   gdb_assert (ops->to_xfer_partial != NULL);
1369 
1370   /* If this is a memory transfer, let the memory-specific code
1371      have a look at it instead.  Memory transfers are more
1372      complicated.  */
1373   if (object == TARGET_OBJECT_MEMORY || object == TARGET_OBJECT_STACK_MEMORY)
1374     retval = memory_xfer_partial (ops, object, readbuf,
1375 				  writebuf, offset, len);
1376   else
1377     {
1378       enum target_object raw_object = object;
1379 
1380       /* If this is a raw memory transfer, request the normal
1381 	 memory object from other layers.  */
1382       if (raw_object == TARGET_OBJECT_RAW_MEMORY)
1383 	raw_object = TARGET_OBJECT_MEMORY;
1384 
1385       retval = ops->to_xfer_partial (ops, raw_object, annex, readbuf,
1386 				     writebuf, offset, len);
1387     }
1388 
1389   if (targetdebug)
1390     {
1391       const unsigned char *myaddr = NULL;
1392 
1393       fprintf_unfiltered (gdb_stdlog,
1394 			  "%s:target_xfer_partial (%d, %s, %s, %s, %s, %s) = %s",
1395 			  ops->to_shortname,
1396 			  (int) object,
1397 			  (annex ? annex : "(null)"),
1398 			  host_address_to_string (readbuf),
1399 			  host_address_to_string (writebuf),
1400 			  core_addr_to_string_nz (offset),
1401 			  plongest (len), plongest (retval));
1402 
1403       if (readbuf)
1404 	myaddr = readbuf;
1405       if (writebuf)
1406 	myaddr = writebuf;
1407       if (retval > 0 && myaddr != NULL)
1408 	{
1409 	  int i;
1410 
1411 	  fputs_unfiltered (", bytes =", gdb_stdlog);
1412 	  for (i = 0; i < retval; i++)
1413 	    {
1414 	      if ((((intptr_t) &(myaddr[i])) & 0xf) == 0)
1415 		{
1416 		  if (targetdebug < 2 && i > 0)
1417 		    {
1418 		      fprintf_unfiltered (gdb_stdlog, " ...");
1419 		      break;
1420 		    }
1421 		  fprintf_unfiltered (gdb_stdlog, "\n");
1422 		}
1423 
1424 	      fprintf_unfiltered (gdb_stdlog, " %02x", myaddr[i] & 0xff);
1425 	    }
1426 	}
1427 
1428       fputc_unfiltered ('\n', gdb_stdlog);
1429     }
1430   return retval;
1431 }
1432 
1433 /* Read LEN bytes of target memory at address MEMADDR, placing the results in
1434    GDB's memory at MYADDR.  Returns either 0 for success or an errno value
1435    if any error occurs.
1436 
1437    If an error occurs, no guarantee is made about the contents of the data at
1438    MYADDR.  In particular, the caller should not depend upon partial reads
1439    filling the buffer with good data.  There is no way for the caller to know
1440    how much good data might have been transfered anyway.  Callers that can
1441    deal with partial reads should call target_read (which will retry until
1442    it makes no progress, and then return how much was transferred). */
1443 
1444 int
1445 target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
1446 {
1447   /* Dispatch to the topmost target, not the flattened current_target.
1448      Memory accesses check target->to_has_(all_)memory, and the
1449      flattened target doesn't inherit those.  */
1450   if (target_read (current_target.beneath, TARGET_OBJECT_MEMORY, NULL,
1451 		   myaddr, memaddr, len) == len)
1452     return 0;
1453   else
1454     return EIO;
1455 }
1456 
1457 /* Like target_read_memory, but specify explicitly that this is a read from
1458    the target's stack.  This may trigger different cache behavior.  */
1459 
1460 int
1461 target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
1462 {
1463   /* Dispatch to the topmost target, not the flattened current_target.
1464      Memory accesses check target->to_has_(all_)memory, and the
1465      flattened target doesn't inherit those.  */
1466 
1467   if (target_read (current_target.beneath, TARGET_OBJECT_STACK_MEMORY, NULL,
1468 		   myaddr, memaddr, len) == len)
1469     return 0;
1470   else
1471     return EIO;
1472 }
1473 
1474 int
1475 target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr, int len)
1476 {
1477   /* Dispatch to the topmost target, not the flattened current_target.
1478      Memory accesses check target->to_has_(all_)memory, and the
1479      flattened target doesn't inherit those.  */
1480   if (target_write (current_target.beneath, TARGET_OBJECT_MEMORY, NULL,
1481 		    myaddr, memaddr, len) == len)
1482     return 0;
1483   else
1484     return EIO;
1485 }
1486 
1487 /* Fetch the target's memory map.  */
1488 
1489 VEC(mem_region_s) *
1490 target_memory_map (void)
1491 {
1492   VEC(mem_region_s) *result;
1493   struct mem_region *last_one, *this_one;
1494   int ix;
1495   struct target_ops *t;
1496 
1497   if (targetdebug)
1498     fprintf_unfiltered (gdb_stdlog, "target_memory_map ()\n");
1499 
1500   for (t = current_target.beneath; t != NULL; t = t->beneath)
1501     if (t->to_memory_map != NULL)
1502       break;
1503 
1504   if (t == NULL)
1505     return NULL;
1506 
1507   result = t->to_memory_map (t);
1508   if (result == NULL)
1509     return NULL;
1510 
1511   qsort (VEC_address (mem_region_s, result),
1512 	 VEC_length (mem_region_s, result),
1513 	 sizeof (struct mem_region), mem_region_cmp);
1514 
1515   /* Check that regions do not overlap.  Simultaneously assign
1516      a numbering for the "mem" commands to use to refer to
1517      each region.  */
1518   last_one = NULL;
1519   for (ix = 0; VEC_iterate (mem_region_s, result, ix, this_one); ix++)
1520     {
1521       this_one->number = ix;
1522 
1523       if (last_one && last_one->hi > this_one->lo)
1524 	{
1525 	  warning (_("Overlapping regions in memory map: ignoring"));
1526 	  VEC_free (mem_region_s, result);
1527 	  return NULL;
1528 	}
1529       last_one = this_one;
1530     }
1531 
1532   return result;
1533 }
1534 
1535 void
1536 target_flash_erase (ULONGEST address, LONGEST length)
1537 {
1538   struct target_ops *t;
1539 
1540   for (t = current_target.beneath; t != NULL; t = t->beneath)
1541     if (t->to_flash_erase != NULL)
1542 	{
1543 	  if (targetdebug)
1544 	    fprintf_unfiltered (gdb_stdlog, "target_flash_erase (%s, %s)\n",
1545                                 hex_string (address), phex (length, 0));
1546 	  t->to_flash_erase (t, address, length);
1547 	  return;
1548 	}
1549 
1550   tcomplain ();
1551 }
1552 
1553 void
1554 target_flash_done (void)
1555 {
1556   struct target_ops *t;
1557 
1558   for (t = current_target.beneath; t != NULL; t = t->beneath)
1559     if (t->to_flash_done != NULL)
1560 	{
1561 	  if (targetdebug)
1562 	    fprintf_unfiltered (gdb_stdlog, "target_flash_done\n");
1563 	  t->to_flash_done (t);
1564 	  return;
1565 	}
1566 
1567   tcomplain ();
1568 }
1569 
1570 static void
1571 show_trust_readonly (struct ui_file *file, int from_tty,
1572 		     struct cmd_list_element *c, const char *value)
1573 {
1574   fprintf_filtered (file, _("\
1575 Mode for reading from readonly sections is %s.\n"),
1576 		    value);
1577 }
1578 
1579 /* More generic transfers.  */
1580 
1581 static LONGEST
1582 default_xfer_partial (struct target_ops *ops, enum target_object object,
1583 		      const char *annex, gdb_byte *readbuf,
1584 		      const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
1585 {
1586   if (object == TARGET_OBJECT_MEMORY
1587       && ops->deprecated_xfer_memory != NULL)
1588     /* If available, fall back to the target's
1589        "deprecated_xfer_memory" method.  */
1590     {
1591       int xfered = -1;
1592       errno = 0;
1593       if (writebuf != NULL)
1594 	{
1595 	  void *buffer = xmalloc (len);
1596 	  struct cleanup *cleanup = make_cleanup (xfree, buffer);
1597 	  memcpy (buffer, writebuf, len);
1598 	  xfered = ops->deprecated_xfer_memory (offset, buffer, len,
1599 						1/*write*/, NULL, ops);
1600 	  do_cleanups (cleanup);
1601 	}
1602       if (readbuf != NULL)
1603 	xfered = ops->deprecated_xfer_memory (offset, readbuf, len,
1604 					      0/*read*/, NULL, ops);
1605       if (xfered > 0)
1606 	return xfered;
1607       else if (xfered == 0 && errno == 0)
1608 	/* "deprecated_xfer_memory" uses 0, cross checked against
1609            ERRNO as one indication of an error.  */
1610 	return 0;
1611       else
1612 	return -1;
1613     }
1614   else if (ops->beneath != NULL)
1615     return ops->beneath->to_xfer_partial (ops->beneath, object, annex,
1616 					  readbuf, writebuf, offset, len);
1617   else
1618     return -1;
1619 }
1620 
1621 /* The xfer_partial handler for the topmost target.  Unlike the default,
1622    it does not need to handle memory specially; it just passes all
1623    requests down the stack.  */
1624 
1625 static LONGEST
1626 current_xfer_partial (struct target_ops *ops, enum target_object object,
1627 		      const char *annex, gdb_byte *readbuf,
1628 		      const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
1629 {
1630   if (ops->beneath != NULL)
1631     return ops->beneath->to_xfer_partial (ops->beneath, object, annex,
1632 					  readbuf, writebuf, offset, len);
1633   else
1634     return -1;
1635 }
1636 
1637 /* Target vector read/write partial wrapper functions.
1638 
1639    NOTE: cagney/2003-10-21: I wonder if having "to_xfer_partial
1640    (inbuf, outbuf)", instead of separate read/write methods, make life
1641    easier.  */
1642 
1643 static LONGEST
1644 target_read_partial (struct target_ops *ops,
1645 		     enum target_object object,
1646 		     const char *annex, gdb_byte *buf,
1647 		     ULONGEST offset, LONGEST len)
1648 {
1649   return target_xfer_partial (ops, object, annex, buf, NULL, offset, len);
1650 }
1651 
1652 static LONGEST
1653 target_write_partial (struct target_ops *ops,
1654 		      enum target_object object,
1655 		      const char *annex, const gdb_byte *buf,
1656 		      ULONGEST offset, LONGEST len)
1657 {
1658   return target_xfer_partial (ops, object, annex, NULL, buf, offset, len);
1659 }
1660 
1661 /* Wrappers to perform the full transfer.  */
1662 LONGEST
1663 target_read (struct target_ops *ops,
1664 	     enum target_object object,
1665 	     const char *annex, gdb_byte *buf,
1666 	     ULONGEST offset, LONGEST len)
1667 {
1668   LONGEST xfered = 0;
1669   while (xfered < len)
1670     {
1671       LONGEST xfer = target_read_partial (ops, object, annex,
1672 					  (gdb_byte *) buf + xfered,
1673 					  offset + xfered, len - xfered);
1674       /* Call an observer, notifying them of the xfer progress?  */
1675       if (xfer == 0)
1676 	return xfered;
1677       if (xfer < 0)
1678 	return -1;
1679       xfered += xfer;
1680       QUIT;
1681     }
1682   return len;
1683 }
1684 
1685 LONGEST
1686 target_read_until_error (struct target_ops *ops,
1687 			 enum target_object object,
1688 			 const char *annex, gdb_byte *buf,
1689 			 ULONGEST offset, LONGEST len)
1690 {
1691   LONGEST xfered = 0;
1692   while (xfered < len)
1693     {
1694       LONGEST xfer = target_read_partial (ops, object, annex,
1695 					  (gdb_byte *) buf + xfered,
1696 					  offset + xfered, len - xfered);
1697       /* Call an observer, notifying them of the xfer progress?  */
1698       if (xfer == 0)
1699 	return xfered;
1700       if (xfer < 0)
1701 	{
1702 	  /* We've got an error.  Try to read in smaller blocks.  */
1703 	  ULONGEST start = offset + xfered;
1704 	  ULONGEST remaining = len - xfered;
1705 	  ULONGEST half;
1706 
1707 	  /* If an attempt was made to read a random memory address,
1708 	     it's likely that the very first byte is not accessible.
1709 	     Try reading the first byte, to avoid doing log N tries
1710 	     below.  */
1711 	  xfer = target_read_partial (ops, object, annex,
1712 				      (gdb_byte *) buf + xfered, start, 1);
1713 	  if (xfer <= 0)
1714 	    return xfered;
1715 	  start += 1;
1716 	  remaining -= 1;
1717 	  half = remaining/2;
1718 
1719 	  while (half > 0)
1720 	    {
1721 	      xfer = target_read_partial (ops, object, annex,
1722 					  (gdb_byte *) buf + xfered,
1723 					  start, half);
1724 	      if (xfer == 0)
1725 		return xfered;
1726 	      if (xfer < 0)
1727 		{
1728 		  remaining = half;
1729 		}
1730 	      else
1731 		{
1732 		  /* We have successfully read the first half.  So, the
1733 		     error must be in the second half.  Adjust start and
1734 		     remaining to point at the second half.  */
1735 		  xfered += xfer;
1736 		  start += xfer;
1737 		  remaining -= xfer;
1738 		}
1739 	      half = remaining/2;
1740 	    }
1741 
1742 	  return xfered;
1743 	}
1744       xfered += xfer;
1745       QUIT;
1746     }
1747   return len;
1748 }
1749 
1750 
1751 /* An alternative to target_write with progress callbacks.  */
1752 
1753 LONGEST
1754 target_write_with_progress (struct target_ops *ops,
1755 			    enum target_object object,
1756 			    const char *annex, const gdb_byte *buf,
1757 			    ULONGEST offset, LONGEST len,
1758 			    void (*progress) (ULONGEST, void *), void *baton)
1759 {
1760   LONGEST xfered = 0;
1761 
1762   /* Give the progress callback a chance to set up.  */
1763   if (progress)
1764     (*progress) (0, baton);
1765 
1766   while (xfered < len)
1767     {
1768       LONGEST xfer = target_write_partial (ops, object, annex,
1769 					   (gdb_byte *) buf + xfered,
1770 					   offset + xfered, len - xfered);
1771 
1772       if (xfer == 0)
1773 	return xfered;
1774       if (xfer < 0)
1775 	return -1;
1776 
1777       if (progress)
1778 	(*progress) (xfer, baton);
1779 
1780       xfered += xfer;
1781       QUIT;
1782     }
1783   return len;
1784 }
1785 
1786 LONGEST
1787 target_write (struct target_ops *ops,
1788 	      enum target_object object,
1789 	      const char *annex, const gdb_byte *buf,
1790 	      ULONGEST offset, LONGEST len)
1791 {
1792   return target_write_with_progress (ops, object, annex, buf, offset, len,
1793 				     NULL, NULL);
1794 }
1795 
1796 /* Read OBJECT/ANNEX using OPS.  Store the result in *BUF_P and return
1797    the size of the transferred data.  PADDING additional bytes are
1798    available in *BUF_P.  This is a helper function for
1799    target_read_alloc; see the declaration of that function for more
1800    information.  */
1801 
1802 static LONGEST
1803 target_read_alloc_1 (struct target_ops *ops, enum target_object object,
1804 		     const char *annex, gdb_byte **buf_p, int padding)
1805 {
1806   size_t buf_alloc, buf_pos;
1807   gdb_byte *buf;
1808   LONGEST n;
1809 
1810   /* This function does not have a length parameter; it reads the
1811      entire OBJECT).  Also, it doesn't support objects fetched partly
1812      from one target and partly from another (in a different stratum,
1813      e.g. a core file and an executable).  Both reasons make it
1814      unsuitable for reading memory.  */
1815   gdb_assert (object != TARGET_OBJECT_MEMORY);
1816 
1817   /* Start by reading up to 4K at a time.  The target will throttle
1818      this number down if necessary.  */
1819   buf_alloc = 4096;
1820   buf = xmalloc (buf_alloc);
1821   buf_pos = 0;
1822   while (1)
1823     {
1824       n = target_read_partial (ops, object, annex, &buf[buf_pos],
1825 			       buf_pos, buf_alloc - buf_pos - padding);
1826       if (n < 0)
1827 	{
1828 	  /* An error occurred.  */
1829 	  xfree (buf);
1830 	  return -1;
1831 	}
1832       else if (n == 0)
1833 	{
1834 	  /* Read all there was.  */
1835 	  if (buf_pos == 0)
1836 	    xfree (buf);
1837 	  else
1838 	    *buf_p = buf;
1839 	  return buf_pos;
1840 	}
1841 
1842       buf_pos += n;
1843 
1844       /* If the buffer is filling up, expand it.  */
1845       if (buf_alloc < buf_pos * 2)
1846 	{
1847 	  buf_alloc *= 2;
1848 	  buf = xrealloc (buf, buf_alloc);
1849 	}
1850 
1851       QUIT;
1852     }
1853 }
1854 
1855 /* Read OBJECT/ANNEX using OPS.  Store the result in *BUF_P and return
1856    the size of the transferred data.  See the declaration in "target.h"
1857    function for more information about the return value.  */
1858 
1859 LONGEST
1860 target_read_alloc (struct target_ops *ops, enum target_object object,
1861 		   const char *annex, gdb_byte **buf_p)
1862 {
1863   return target_read_alloc_1 (ops, object, annex, buf_p, 0);
1864 }
1865 
1866 /* Read OBJECT/ANNEX using OPS.  The result is NUL-terminated and
1867    returned as a string, allocated using xmalloc.  If an error occurs
1868    or the transfer is unsupported, NULL is returned.  Empty objects
1869    are returned as allocated but empty strings.  A warning is issued
1870    if the result contains any embedded NUL bytes.  */
1871 
1872 char *
1873 target_read_stralloc (struct target_ops *ops, enum target_object object,
1874 		      const char *annex)
1875 {
1876   gdb_byte *buffer;
1877   LONGEST transferred;
1878 
1879   transferred = target_read_alloc_1 (ops, object, annex, &buffer, 1);
1880 
1881   if (transferred < 0)
1882     return NULL;
1883 
1884   if (transferred == 0)
1885     return xstrdup ("");
1886 
1887   buffer[transferred] = 0;
1888   if (strlen (buffer) < transferred)
1889     warning (_("target object %d, annex %s, "
1890 	       "contained unexpected null characters"),
1891 	     (int) object, annex ? annex : "(none)");
1892 
1893   return (char *) buffer;
1894 }
1895 
1896 /* Memory transfer methods.  */
1897 
1898 void
1899 get_target_memory (struct target_ops *ops, CORE_ADDR addr, gdb_byte *buf,
1900 		   LONGEST len)
1901 {
1902   /* This method is used to read from an alternate, non-current
1903      target.  This read must bypass the overlay support (as symbols
1904      don't match this target), and GDB's internal cache (wrong cache
1905      for this target).  */
1906   if (target_read (ops, TARGET_OBJECT_RAW_MEMORY, NULL, buf, addr, len)
1907       != len)
1908     memory_error (EIO, addr);
1909 }
1910 
1911 ULONGEST
1912 get_target_memory_unsigned (struct target_ops *ops,
1913 			    CORE_ADDR addr, int len, enum bfd_endian byte_order)
1914 {
1915   gdb_byte buf[sizeof (ULONGEST)];
1916 
1917   gdb_assert (len <= sizeof (buf));
1918   get_target_memory (ops, addr, buf, len);
1919   return extract_unsigned_integer (buf, len, byte_order);
1920 }
1921 
1922 static void
1923 target_info (char *args, int from_tty)
1924 {
1925   struct target_ops *t;
1926   int has_all_mem = 0;
1927 
1928   if (symfile_objfile != NULL)
1929     printf_unfiltered (_("Symbols from \"%s\".\n"), symfile_objfile->name);
1930 
1931   for (t = target_stack; t != NULL; t = t->beneath)
1932     {
1933       if (!(*t->to_has_memory) (t))
1934 	continue;
1935 
1936       if ((int) (t->to_stratum) <= (int) dummy_stratum)
1937 	continue;
1938       if (has_all_mem)
1939 	printf_unfiltered (_("\tWhile running this, GDB does not access memory from...\n"));
1940       printf_unfiltered ("%s:\n", t->to_longname);
1941       (t->to_files_info) (t);
1942       has_all_mem = (*t->to_has_all_memory) (t);
1943     }
1944 }
1945 
1946 /* This function is called before any new inferior is created, e.g.
1947    by running a program, attaching, or connecting to a target.
1948    It cleans up any state from previous invocations which might
1949    change between runs.  This is a subset of what target_preopen
1950    resets (things which might change between targets).  */
1951 
1952 void
1953 target_pre_inferior (int from_tty)
1954 {
1955   /* Clear out solib state. Otherwise the solib state of the previous
1956      inferior might have survived and is entirely wrong for the new
1957      target.  This has been observed on GNU/Linux using glibc 2.3. How
1958      to reproduce:
1959 
1960      bash$ ./foo&
1961      [1] 4711
1962      bash$ ./foo&
1963      [1] 4712
1964      bash$ gdb ./foo
1965      [...]
1966      (gdb) attach 4711
1967      (gdb) detach
1968      (gdb) attach 4712
1969      Cannot access memory at address 0xdeadbeef
1970   */
1971 
1972   /* In some OSs, the shared library list is the same/global/shared
1973      across inferiors.  If code is shared between processes, so are
1974      memory regions and features.  */
1975   if (!gdbarch_has_global_solist (target_gdbarch))
1976     {
1977       no_shared_libraries (NULL, from_tty);
1978 
1979       invalidate_target_mem_regions ();
1980 
1981       target_clear_description ();
1982     }
1983 }
1984 
1985 /* Callback for iterate_over_inferiors.  Gets rid of the given
1986    inferior.  */
1987 
1988 static int
1989 dispose_inferior (struct inferior *inf, void *args)
1990 {
1991   struct thread_info *thread;
1992 
1993   thread = any_thread_of_process (inf->pid);
1994   if (thread)
1995     {
1996       switch_to_thread (thread->ptid);
1997 
1998       /* Core inferiors actually should be detached, not killed.  */
1999       if (target_has_execution)
2000 	target_kill ();
2001       else
2002 	target_detach (NULL, 0);
2003     }
2004 
2005   return 0;
2006 }
2007 
2008 /* This is to be called by the open routine before it does
2009    anything.  */
2010 
2011 void
2012 target_preopen (int from_tty)
2013 {
2014   dont_repeat ();
2015 
2016   if (have_inferiors ())
2017     {
2018       if (!from_tty
2019 	  || !have_live_inferiors ()
2020 	  || query (_("A program is being debugged already.  Kill it? ")))
2021 	iterate_over_inferiors (dispose_inferior, NULL);
2022       else
2023 	error (_("Program not killed."));
2024     }
2025 
2026   /* Calling target_kill may remove the target from the stack.  But if
2027      it doesn't (which seems like a win for UDI), remove it now.  */
2028   /* Leave the exec target, though.  The user may be switching from a
2029      live process to a core of the same program.  */
2030   pop_all_targets_above (file_stratum, 0);
2031 
2032   target_pre_inferior (from_tty);
2033 }
2034 
2035 /* Detach a target after doing deferred register stores.  */
2036 
2037 void
2038 target_detach (char *args, int from_tty)
2039 {
2040   struct target_ops* t;
2041 
2042   if (gdbarch_has_global_breakpoints (target_gdbarch))
2043     /* Don't remove global breakpoints here.  They're removed on
2044        disconnection from the target.  */
2045     ;
2046   else
2047     /* If we're in breakpoints-always-inserted mode, have to remove
2048        them before detaching.  */
2049     remove_breakpoints ();
2050 
2051   for (t = current_target.beneath; t != NULL; t = t->beneath)
2052     {
2053       if (t->to_detach != NULL)
2054 	{
2055 	  t->to_detach (t, args, from_tty);
2056 	  if (targetdebug)
2057 	    fprintf_unfiltered (gdb_stdlog, "target_detach (%s, %d)\n",
2058 				args, from_tty);
2059 	  return;
2060 	}
2061     }
2062 
2063   internal_error (__FILE__, __LINE__, "could not find a target to detach");
2064 }
2065 
2066 void
2067 target_disconnect (char *args, int from_tty)
2068 {
2069   struct target_ops *t;
2070 
2071   /* If we're in breakpoints-always-inserted mode or if breakpoints
2072      are global across processes, we have to remove them before
2073      disconnecting.  */
2074   remove_breakpoints ();
2075 
2076   for (t = current_target.beneath; t != NULL; t = t->beneath)
2077     if (t->to_disconnect != NULL)
2078 	{
2079 	  if (targetdebug)
2080 	    fprintf_unfiltered (gdb_stdlog, "target_disconnect (%s, %d)\n",
2081 				args, from_tty);
2082 	  t->to_disconnect (t, args, from_tty);
2083 	  return;
2084 	}
2085 
2086   tcomplain ();
2087 }
2088 
2089 ptid_t
2090 target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
2091 {
2092   struct target_ops *t;
2093 
2094   for (t = current_target.beneath; t != NULL; t = t->beneath)
2095     {
2096       if (t->to_wait != NULL)
2097 	{
2098 	  ptid_t retval = (*t->to_wait) (t, ptid, status, options);
2099 
2100 	  if (targetdebug)
2101 	    {
2102 	      char *status_string;
2103 
2104 	      status_string = target_waitstatus_to_string (status);
2105 	      fprintf_unfiltered (gdb_stdlog,
2106 				  "target_wait (%d, status) = %d,   %s\n",
2107 				  PIDGET (ptid), PIDGET (retval),
2108 				  status_string);
2109 	      xfree (status_string);
2110 	    }
2111 
2112 	  return retval;
2113 	}
2114     }
2115 
2116   noprocess ();
2117 }
2118 
2119 char *
2120 target_pid_to_str (ptid_t ptid)
2121 {
2122   struct target_ops *t;
2123 
2124   for (t = current_target.beneath; t != NULL; t = t->beneath)
2125     {
2126       if (t->to_pid_to_str != NULL)
2127 	return (*t->to_pid_to_str) (t, ptid);
2128     }
2129 
2130   return normal_pid_to_str (ptid);
2131 }
2132 
2133 void
2134 target_resume (ptid_t ptid, int step, enum target_signal signal)
2135 {
2136   struct target_ops *t;
2137 
2138   target_dcache_invalidate ();
2139 
2140   for (t = current_target.beneath; t != NULL; t = t->beneath)
2141     {
2142       if (t->to_resume != NULL)
2143 	{
2144 	  t->to_resume (t, ptid, step, signal);
2145 	  if (targetdebug)
2146 	    fprintf_unfiltered (gdb_stdlog, "target_resume (%d, %s, %s)\n",
2147 				PIDGET (ptid),
2148 				step ? "step" : "continue",
2149 				target_signal_to_name (signal));
2150 
2151 	  set_executing (ptid, 1);
2152 	  set_running (ptid, 1);
2153 	  clear_inline_frame_state (ptid);
2154 	  return;
2155 	}
2156     }
2157 
2158   noprocess ();
2159 }
2160 /* Look through the list of possible targets for a target that can
2161    follow forks.  */
2162 
2163 int
2164 target_follow_fork (int follow_child)
2165 {
2166   struct target_ops *t;
2167 
2168   for (t = current_target.beneath; t != NULL; t = t->beneath)
2169     {
2170       if (t->to_follow_fork != NULL)
2171 	{
2172 	  int retval = t->to_follow_fork (t, follow_child);
2173 	  if (targetdebug)
2174 	    fprintf_unfiltered (gdb_stdlog, "target_follow_fork (%d) = %d\n",
2175 				follow_child, retval);
2176 	  return retval;
2177 	}
2178     }
2179 
2180   /* Some target returned a fork event, but did not know how to follow it.  */
2181   internal_error (__FILE__, __LINE__,
2182 		  "could not find a target to follow fork");
2183 }
2184 
2185 void
2186 target_mourn_inferior (void)
2187 {
2188   struct target_ops *t;
2189   for (t = current_target.beneath; t != NULL; t = t->beneath)
2190     {
2191       if (t->to_mourn_inferior != NULL)
2192 	{
2193 	  t->to_mourn_inferior (t);
2194 	  if (targetdebug)
2195 	    fprintf_unfiltered (gdb_stdlog, "target_mourn_inferior ()\n");
2196 
2197           /* We no longer need to keep handles on any of the object files.
2198              Make sure to release them to avoid unnecessarily locking any
2199              of them while we're not actually debugging.  */
2200           bfd_cache_close_all ();
2201 
2202 	  return;
2203 	}
2204     }
2205 
2206   internal_error (__FILE__, __LINE__,
2207 		  "could not find a target to follow mourn inferiour");
2208 }
2209 
2210 /* Look for a target which can describe architectural features, starting
2211    from TARGET.  If we find one, return its description.  */
2212 
2213 const struct target_desc *
2214 target_read_description (struct target_ops *target)
2215 {
2216   struct target_ops *t;
2217 
2218   for (t = target; t != NULL; t = t->beneath)
2219     if (t->to_read_description != NULL)
2220       {
2221 	const struct target_desc *tdesc;
2222 
2223 	tdesc = t->to_read_description (t);
2224 	if (tdesc)
2225 	  return tdesc;
2226       }
2227 
2228   return NULL;
2229 }
2230 
2231 /* The default implementation of to_search_memory.
2232    This implements a basic search of memory, reading target memory and
2233    performing the search here (as opposed to performing the search in on the
2234    target side with, for example, gdbserver).  */
2235 
2236 int
2237 simple_search_memory (struct target_ops *ops,
2238 		      CORE_ADDR start_addr, ULONGEST search_space_len,
2239 		      const gdb_byte *pattern, ULONGEST pattern_len,
2240 		      CORE_ADDR *found_addrp)
2241 {
2242   /* NOTE: also defined in find.c testcase.  */
2243 #define SEARCH_CHUNK_SIZE 16000
2244   const unsigned chunk_size = SEARCH_CHUNK_SIZE;
2245   /* Buffer to hold memory contents for searching.  */
2246   gdb_byte *search_buf;
2247   unsigned search_buf_size;
2248   struct cleanup *old_cleanups;
2249 
2250   search_buf_size = chunk_size + pattern_len - 1;
2251 
2252   /* No point in trying to allocate a buffer larger than the search space.  */
2253   if (search_space_len < search_buf_size)
2254     search_buf_size = search_space_len;
2255 
2256   search_buf = malloc (search_buf_size);
2257   if (search_buf == NULL)
2258     error (_("Unable to allocate memory to perform the search."));
2259   old_cleanups = make_cleanup (free_current_contents, &search_buf);
2260 
2261   /* Prime the search buffer.  */
2262 
2263   if (target_read (ops, TARGET_OBJECT_MEMORY, NULL,
2264 		   search_buf, start_addr, search_buf_size) != search_buf_size)
2265     {
2266       warning (_("Unable to access target memory at %s, halting search."),
2267 	       hex_string (start_addr));
2268       do_cleanups (old_cleanups);
2269       return -1;
2270     }
2271 
2272   /* Perform the search.
2273 
2274      The loop is kept simple by allocating [N + pattern-length - 1] bytes.
2275      When we've scanned N bytes we copy the trailing bytes to the start and
2276      read in another N bytes.  */
2277 
2278   while (search_space_len >= pattern_len)
2279     {
2280       gdb_byte *found_ptr;
2281       unsigned nr_search_bytes = min (search_space_len, search_buf_size);
2282 
2283       found_ptr = memmem (search_buf, nr_search_bytes,
2284 			  pattern, pattern_len);
2285 
2286       if (found_ptr != NULL)
2287 	{
2288 	  CORE_ADDR found_addr = start_addr + (found_ptr - search_buf);
2289 	  *found_addrp = found_addr;
2290 	  do_cleanups (old_cleanups);
2291 	  return 1;
2292 	}
2293 
2294       /* Not found in this chunk, skip to next chunk.  */
2295 
2296       /* Don't let search_space_len wrap here, it's unsigned.  */
2297       if (search_space_len >= chunk_size)
2298 	search_space_len -= chunk_size;
2299       else
2300 	search_space_len = 0;
2301 
2302       if (search_space_len >= pattern_len)
2303 	{
2304 	  unsigned keep_len = search_buf_size - chunk_size;
2305 	  CORE_ADDR read_addr = start_addr + keep_len;
2306 	  int nr_to_read;
2307 
2308 	  /* Copy the trailing part of the previous iteration to the front
2309 	     of the buffer for the next iteration.  */
2310 	  gdb_assert (keep_len == pattern_len - 1);
2311 	  memcpy (search_buf, search_buf + chunk_size, keep_len);
2312 
2313 	  nr_to_read = min (search_space_len - keep_len, chunk_size);
2314 
2315 	  if (target_read (ops, TARGET_OBJECT_MEMORY, NULL,
2316 			   search_buf + keep_len, read_addr,
2317 			   nr_to_read) != nr_to_read)
2318 	    {
2319 	      warning (_("Unable to access target memory at %s, halting search."),
2320 		       hex_string (read_addr));
2321 	      do_cleanups (old_cleanups);
2322 	      return -1;
2323 	    }
2324 
2325 	  start_addr += chunk_size;
2326 	}
2327     }
2328 
2329   /* Not found.  */
2330 
2331   do_cleanups (old_cleanups);
2332   return 0;
2333 }
2334 
2335 /* Search SEARCH_SPACE_LEN bytes beginning at START_ADDR for the
2336    sequence of bytes in PATTERN with length PATTERN_LEN.
2337 
2338    The result is 1 if found, 0 if not found, and -1 if there was an error
2339    requiring halting of the search (e.g. memory read error).
2340    If the pattern is found the address is recorded in FOUND_ADDRP.  */
2341 
2342 int
2343 target_search_memory (CORE_ADDR start_addr, ULONGEST search_space_len,
2344 		      const gdb_byte *pattern, ULONGEST pattern_len,
2345 		      CORE_ADDR *found_addrp)
2346 {
2347   struct target_ops *t;
2348   int found;
2349 
2350   /* We don't use INHERIT to set current_target.to_search_memory,
2351      so we have to scan the target stack and handle targetdebug
2352      ourselves.  */
2353 
2354   if (targetdebug)
2355     fprintf_unfiltered (gdb_stdlog, "target_search_memory (%s, ...)\n",
2356 			hex_string (start_addr));
2357 
2358   for (t = current_target.beneath; t != NULL; t = t->beneath)
2359     if (t->to_search_memory != NULL)
2360       break;
2361 
2362   if (t != NULL)
2363     {
2364       found = t->to_search_memory (t, start_addr, search_space_len,
2365 				   pattern, pattern_len, found_addrp);
2366     }
2367   else
2368     {
2369       /* If a special version of to_search_memory isn't available, use the
2370 	 simple version.  */
2371       found = simple_search_memory (current_target.beneath,
2372 				    start_addr, search_space_len,
2373 				    pattern, pattern_len, found_addrp);
2374     }
2375 
2376   if (targetdebug)
2377     fprintf_unfiltered (gdb_stdlog, "  = %d\n", found);
2378 
2379   return found;
2380 }
2381 
2382 /* Look through the currently pushed targets.  If none of them will
2383    be able to restart the currently running process, issue an error
2384    message.  */
2385 
2386 void
2387 target_require_runnable (void)
2388 {
2389   struct target_ops *t;
2390 
2391   for (t = target_stack; t != NULL; t = t->beneath)
2392     {
2393       /* If this target knows how to create a new program, then
2394 	 assume we will still be able to after killing the current
2395 	 one.  Either killing and mourning will not pop T, or else
2396 	 find_default_run_target will find it again.  */
2397       if (t->to_create_inferior != NULL)
2398 	return;
2399 
2400       /* Do not worry about thread_stratum targets that can not
2401 	 create inferiors.  Assume they will be pushed again if
2402 	 necessary, and continue to the process_stratum.  */
2403       if (t->to_stratum == thread_stratum
2404 	  || t->to_stratum == arch_stratum)
2405 	continue;
2406 
2407       error (_("\
2408 The \"%s\" target does not support \"run\".  Try \"help target\" or \"continue\"."),
2409 	     t->to_shortname);
2410     }
2411 
2412   /* This function is only called if the target is running.  In that
2413      case there should have been a process_stratum target and it
2414      should either know how to create inferiors, or not... */
2415   internal_error (__FILE__, __LINE__, "No targets found");
2416 }
2417 
2418 /* Look through the list of possible targets for a target that can
2419    execute a run or attach command without any other data.  This is
2420    used to locate the default process stratum.
2421 
2422    If DO_MESG is not NULL, the result is always valid (error() is
2423    called for errors); else, return NULL on error.  */
2424 
2425 static struct target_ops *
2426 find_default_run_target (char *do_mesg)
2427 {
2428   struct target_ops **t;
2429   struct target_ops *runable = NULL;
2430   int count;
2431 
2432   count = 0;
2433 
2434   for (t = target_structs; t < target_structs + target_struct_size;
2435        ++t)
2436     {
2437       if ((*t)->to_can_run && target_can_run (*t))
2438 	{
2439 	  runable = *t;
2440 	  ++count;
2441 	}
2442     }
2443 
2444   if (count != 1)
2445     {
2446       if (do_mesg)
2447 	error (_("Don't know how to %s.  Try \"help target\"."), do_mesg);
2448       else
2449 	return NULL;
2450     }
2451 
2452   return runable;
2453 }
2454 
2455 void
2456 find_default_attach (struct target_ops *ops, char *args, int from_tty)
2457 {
2458   struct target_ops *t;
2459 
2460   t = find_default_run_target ("attach");
2461   (t->to_attach) (t, args, from_tty);
2462   return;
2463 }
2464 
2465 void
2466 find_default_create_inferior (struct target_ops *ops,
2467 			      char *exec_file, char *allargs, char **env,
2468 			      int from_tty)
2469 {
2470   struct target_ops *t;
2471 
2472   t = find_default_run_target ("run");
2473   (t->to_create_inferior) (t, exec_file, allargs, env, from_tty);
2474   return;
2475 }
2476 
2477 static int
2478 find_default_can_async_p (void)
2479 {
2480   struct target_ops *t;
2481 
2482   /* This may be called before the target is pushed on the stack;
2483      look for the default process stratum.  If there's none, gdb isn't
2484      configured with a native debugger, and target remote isn't
2485      connected yet.  */
2486   t = find_default_run_target (NULL);
2487   if (t && t->to_can_async_p)
2488     return (t->to_can_async_p) ();
2489   return 0;
2490 }
2491 
2492 static int
2493 find_default_is_async_p (void)
2494 {
2495   struct target_ops *t;
2496 
2497   /* This may be called before the target is pushed on the stack;
2498      look for the default process stratum.  If there's none, gdb isn't
2499      configured with a native debugger, and target remote isn't
2500      connected yet.  */
2501   t = find_default_run_target (NULL);
2502   if (t && t->to_is_async_p)
2503     return (t->to_is_async_p) ();
2504   return 0;
2505 }
2506 
2507 static int
2508 find_default_supports_non_stop (void)
2509 {
2510   struct target_ops *t;
2511 
2512   t = find_default_run_target (NULL);
2513   if (t && t->to_supports_non_stop)
2514     return (t->to_supports_non_stop) ();
2515   return 0;
2516 }
2517 
2518 int
2519 target_supports_non_stop (void)
2520 {
2521   struct target_ops *t;
2522   for (t = &current_target; t != NULL; t = t->beneath)
2523     if (t->to_supports_non_stop)
2524       return t->to_supports_non_stop ();
2525 
2526   return 0;
2527 }
2528 
2529 
2530 char *
2531 target_get_osdata (const char *type)
2532 {
2533   char *document;
2534   struct target_ops *t;
2535 
2536   /* If we're already connected to something that can get us OS
2537      related data, use it.  Otherwise, try using the native
2538      target.  */
2539   if (current_target.to_stratum >= process_stratum)
2540     t = current_target.beneath;
2541   else
2542     t = find_default_run_target ("get OS data");
2543 
2544   if (!t)
2545     return NULL;
2546 
2547   return target_read_stralloc (t, TARGET_OBJECT_OSDATA, type);
2548 }
2549 
2550 static int
2551 default_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
2552 {
2553   return (len <= gdbarch_ptr_bit (target_gdbarch) / TARGET_CHAR_BIT);
2554 }
2555 
2556 static int
2557 default_watchpoint_addr_within_range (struct target_ops *target,
2558 				      CORE_ADDR addr,
2559 				      CORE_ADDR start, int length)
2560 {
2561   return addr >= start && addr < start + length;
2562 }
2563 
2564 static struct gdbarch *
2565 default_thread_architecture (struct target_ops *ops, ptid_t ptid)
2566 {
2567   return target_gdbarch;
2568 }
2569 
2570 static int
2571 return_zero (void)
2572 {
2573   return 0;
2574 }
2575 
2576 static int
2577 return_one (void)
2578 {
2579   return 1;
2580 }
2581 
2582 static int
2583 return_minus_one (void)
2584 {
2585   return -1;
2586 }
2587 
2588 /* Find a single runnable target in the stack and return it.  If for
2589    some reason there is more than one, return NULL.  */
2590 
2591 struct target_ops *
2592 find_run_target (void)
2593 {
2594   struct target_ops **t;
2595   struct target_ops *runable = NULL;
2596   int count;
2597 
2598   count = 0;
2599 
2600   for (t = target_structs; t < target_structs + target_struct_size; ++t)
2601     {
2602       if ((*t)->to_can_run && target_can_run (*t))
2603 	{
2604 	  runable = *t;
2605 	  ++count;
2606 	}
2607     }
2608 
2609   return (count == 1 ? runable : NULL);
2610 }
2611 
2612 /* Find a single core_stratum target in the list of targets and return it.
2613    If for some reason there is more than one, return NULL.  */
2614 
2615 struct target_ops *
2616 find_core_target (void)
2617 {
2618   struct target_ops **t;
2619   struct target_ops *runable = NULL;
2620   int count;
2621 
2622   count = 0;
2623 
2624   for (t = target_structs; t < target_structs + target_struct_size;
2625        ++t)
2626     {
2627       if ((*t)->to_stratum == core_stratum)
2628 	{
2629 	  runable = *t;
2630 	  ++count;
2631 	}
2632     }
2633 
2634   return (count == 1 ? runable : NULL);
2635 }
2636 
2637 /*
2638  * Find the next target down the stack from the specified target.
2639  */
2640 
2641 struct target_ops *
2642 find_target_beneath (struct target_ops *t)
2643 {
2644   return t->beneath;
2645 }
2646 
2647 
2648 /* The inferior process has died.  Long live the inferior!  */
2649 
2650 void
2651 generic_mourn_inferior (void)
2652 {
2653   ptid_t ptid;
2654 
2655   ptid = inferior_ptid;
2656   inferior_ptid = null_ptid;
2657 
2658   if (!ptid_equal (ptid, null_ptid))
2659     {
2660       int pid = ptid_get_pid (ptid);
2661       delete_inferior (pid);
2662     }
2663 
2664   breakpoint_init_inferior (inf_exited);
2665   registers_changed ();
2666 
2667   reopen_exec_file ();
2668   reinit_frame_cache ();
2669 
2670   if (deprecated_detach_hook)
2671     deprecated_detach_hook ();
2672 }
2673 
2674 /* Helper function for child_wait and the derivatives of child_wait.
2675    HOSTSTATUS is the waitstatus from wait() or the equivalent; store our
2676    translation of that in OURSTATUS.  */
2677 void
2678 store_waitstatus (struct target_waitstatus *ourstatus, int hoststatus)
2679 {
2680   if (WIFEXITED (hoststatus))
2681     {
2682       ourstatus->kind = TARGET_WAITKIND_EXITED;
2683       ourstatus->value.integer = WEXITSTATUS (hoststatus);
2684     }
2685   else if (!WIFSTOPPED (hoststatus))
2686     {
2687       ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
2688       ourstatus->value.sig = target_signal_from_host (WTERMSIG (hoststatus));
2689     }
2690   else
2691     {
2692       ourstatus->kind = TARGET_WAITKIND_STOPPED;
2693       ourstatus->value.sig = target_signal_from_host (WSTOPSIG (hoststatus));
2694     }
2695 }
2696 
2697 /* Convert a normal process ID to a string.  Returns the string in a
2698    static buffer.  */
2699 
2700 char *
2701 normal_pid_to_str (ptid_t ptid)
2702 {
2703   static char buf[32];
2704 
2705   xsnprintf (buf, sizeof buf, "process %d", ptid_get_pid (ptid));
2706   return buf;
2707 }
2708 
2709 static char *
2710 dummy_pid_to_str (struct target_ops *ops, ptid_t ptid)
2711 {
2712   return normal_pid_to_str (ptid);
2713 }
2714 
2715 /* Error-catcher for target_find_memory_regions */
2716 static int dummy_find_memory_regions (int (*ignore1) (), void *ignore2)
2717 {
2718   error (_("No target."));
2719   return 0;
2720 }
2721 
2722 /* Error-catcher for target_make_corefile_notes */
2723 static char * dummy_make_corefile_notes (bfd *ignore1, int *ignore2)
2724 {
2725   error (_("No target."));
2726   return NULL;
2727 }
2728 
2729 /* Set up the handful of non-empty slots needed by the dummy target
2730    vector.  */
2731 
2732 static void
2733 init_dummy_target (void)
2734 {
2735   dummy_target.to_shortname = "None";
2736   dummy_target.to_longname = "None";
2737   dummy_target.to_doc = "";
2738   dummy_target.to_attach = find_default_attach;
2739   dummy_target.to_detach =
2740     (void (*)(struct target_ops *, char *, int))target_ignore;
2741   dummy_target.to_create_inferior = find_default_create_inferior;
2742   dummy_target.to_can_async_p = find_default_can_async_p;
2743   dummy_target.to_is_async_p = find_default_is_async_p;
2744   dummy_target.to_supports_non_stop = find_default_supports_non_stop;
2745   dummy_target.to_pid_to_str = dummy_pid_to_str;
2746   dummy_target.to_stratum = dummy_stratum;
2747   dummy_target.to_find_memory_regions = dummy_find_memory_regions;
2748   dummy_target.to_make_corefile_notes = dummy_make_corefile_notes;
2749   dummy_target.to_xfer_partial = default_xfer_partial;
2750   dummy_target.to_has_all_memory = (int (*) (struct target_ops *)) return_zero;
2751   dummy_target.to_has_memory = (int (*) (struct target_ops *)) return_zero;
2752   dummy_target.to_has_stack = (int (*) (struct target_ops *)) return_zero;
2753   dummy_target.to_has_registers = (int (*) (struct target_ops *)) return_zero;
2754   dummy_target.to_has_execution = (int (*) (struct target_ops *)) return_zero;
2755   dummy_target.to_magic = OPS_MAGIC;
2756 }
2757 
2758 static void
2759 debug_to_open (char *args, int from_tty)
2760 {
2761   debug_target.to_open (args, from_tty);
2762 
2763   fprintf_unfiltered (gdb_stdlog, "target_open (%s, %d)\n", args, from_tty);
2764 }
2765 
2766 void
2767 target_close (struct target_ops *targ, int quitting)
2768 {
2769   if (targ->to_xclose != NULL)
2770     targ->to_xclose (targ, quitting);
2771   else if (targ->to_close != NULL)
2772     targ->to_close (quitting);
2773 
2774   if (targetdebug)
2775     fprintf_unfiltered (gdb_stdlog, "target_close (%d)\n", quitting);
2776 }
2777 
2778 void
2779 target_attach (char *args, int from_tty)
2780 {
2781   struct target_ops *t;
2782   for (t = current_target.beneath; t != NULL; t = t->beneath)
2783     {
2784       if (t->to_attach != NULL)
2785 	{
2786 	  t->to_attach (t, args, from_tty);
2787 	  if (targetdebug)
2788 	    fprintf_unfiltered (gdb_stdlog, "target_attach (%s, %d)\n",
2789 				args, from_tty);
2790 	  return;
2791 	}
2792     }
2793 
2794   internal_error (__FILE__, __LINE__,
2795 		  "could not find a target to attach");
2796 }
2797 
2798 int
2799 target_thread_alive (ptid_t ptid)
2800 {
2801   struct target_ops *t;
2802   for (t = current_target.beneath; t != NULL; t = t->beneath)
2803     {
2804       if (t->to_thread_alive != NULL)
2805 	{
2806 	  int retval;
2807 
2808 	  retval = t->to_thread_alive (t, ptid);
2809 	  if (targetdebug)
2810 	    fprintf_unfiltered (gdb_stdlog, "target_thread_alive (%d) = %d\n",
2811 				PIDGET (ptid), retval);
2812 
2813 	  return retval;
2814 	}
2815     }
2816 
2817   return 0;
2818 }
2819 
2820 void
2821 target_find_new_threads (void)
2822 {
2823   struct target_ops *t;
2824   for (t = current_target.beneath; t != NULL; t = t->beneath)
2825     {
2826       if (t->to_find_new_threads != NULL)
2827 	{
2828 	  t->to_find_new_threads (t);
2829 	  if (targetdebug)
2830 	    fprintf_unfiltered (gdb_stdlog, "target_find_new_threads ()\n");
2831 
2832 	  return;
2833 	}
2834     }
2835 }
2836 
2837 static void
2838 debug_to_post_attach (int pid)
2839 {
2840   debug_target.to_post_attach (pid);
2841 
2842   fprintf_unfiltered (gdb_stdlog, "target_post_attach (%d)\n", pid);
2843 }
2844 
2845 /* Return a pretty printed form of target_waitstatus.
2846    Space for the result is malloc'd, caller must free.  */
2847 
2848 char *
2849 target_waitstatus_to_string (const struct target_waitstatus *ws)
2850 {
2851   const char *kind_str = "status->kind = ";
2852 
2853   switch (ws->kind)
2854     {
2855     case TARGET_WAITKIND_EXITED:
2856       return xstrprintf ("%sexited, status = %d",
2857 			 kind_str, ws->value.integer);
2858     case TARGET_WAITKIND_STOPPED:
2859       return xstrprintf ("%sstopped, signal = %s",
2860 			 kind_str, target_signal_to_name (ws->value.sig));
2861     case TARGET_WAITKIND_SIGNALLED:
2862       return xstrprintf ("%ssignalled, signal = %s",
2863 			 kind_str, target_signal_to_name (ws->value.sig));
2864     case TARGET_WAITKIND_LOADED:
2865       return xstrprintf ("%sloaded", kind_str);
2866     case TARGET_WAITKIND_FORKED:
2867       return xstrprintf ("%sforked", kind_str);
2868     case TARGET_WAITKIND_VFORKED:
2869       return xstrprintf ("%svforked", kind_str);
2870     case TARGET_WAITKIND_EXECD:
2871       return xstrprintf ("%sexecd", kind_str);
2872     case TARGET_WAITKIND_SYSCALL_ENTRY:
2873       return xstrprintf ("%sentered syscall", kind_str);
2874     case TARGET_WAITKIND_SYSCALL_RETURN:
2875       return xstrprintf ("%sexited syscall", kind_str);
2876     case TARGET_WAITKIND_SPURIOUS:
2877       return xstrprintf ("%sspurious", kind_str);
2878     case TARGET_WAITKIND_IGNORE:
2879       return xstrprintf ("%signore", kind_str);
2880     case TARGET_WAITKIND_NO_HISTORY:
2881       return xstrprintf ("%sno-history", kind_str);
2882     default:
2883       return xstrprintf ("%sunknown???", kind_str);
2884     }
2885 }
2886 
2887 static void
2888 debug_print_register (const char * func,
2889 		      struct regcache *regcache, int regno)
2890 {
2891   struct gdbarch *gdbarch = get_regcache_arch (regcache);
2892   fprintf_unfiltered (gdb_stdlog, "%s ", func);
2893   if (regno >= 0 && regno < gdbarch_num_regs (gdbarch)
2894       && gdbarch_register_name (gdbarch, regno) != NULL
2895       && gdbarch_register_name (gdbarch, regno)[0] != '\0')
2896     fprintf_unfiltered (gdb_stdlog, "(%s)",
2897 			gdbarch_register_name (gdbarch, regno));
2898   else
2899     fprintf_unfiltered (gdb_stdlog, "(%d)", regno);
2900   if (regno >= 0 && regno < gdbarch_num_regs (gdbarch))
2901     {
2902       enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2903       int i, size = register_size (gdbarch, regno);
2904       unsigned char buf[MAX_REGISTER_SIZE];
2905       regcache_raw_collect (regcache, regno, buf);
2906       fprintf_unfiltered (gdb_stdlog, " = ");
2907       for (i = 0; i < size; i++)
2908 	{
2909 	  fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
2910 	}
2911       if (size <= sizeof (LONGEST))
2912 	{
2913 	  ULONGEST val = extract_unsigned_integer (buf, size, byte_order);
2914 	  fprintf_unfiltered (gdb_stdlog, " %s %s",
2915 			      core_addr_to_string_nz (val), plongest (val));
2916 	}
2917     }
2918   fprintf_unfiltered (gdb_stdlog, "\n");
2919 }
2920 
2921 void
2922 target_fetch_registers (struct regcache *regcache, int regno)
2923 {
2924   struct target_ops *t;
2925   for (t = current_target.beneath; t != NULL; t = t->beneath)
2926     {
2927       if (t->to_fetch_registers != NULL)
2928 	{
2929 	  t->to_fetch_registers (t, regcache, regno);
2930 	  if (targetdebug)
2931 	    debug_print_register ("target_fetch_registers", regcache, regno);
2932 	  return;
2933 	}
2934     }
2935 }
2936 
2937 void
2938 target_store_registers (struct regcache *regcache, int regno)
2939 {
2940 
2941   struct target_ops *t;
2942   for (t = current_target.beneath; t != NULL; t = t->beneath)
2943     {
2944       if (t->to_store_registers != NULL)
2945 	{
2946 	  t->to_store_registers (t, regcache, regno);
2947 	  if (targetdebug)
2948 	    {
2949 	      debug_print_register ("target_store_registers", regcache, regno);
2950 	    }
2951 	  return;
2952 	}
2953     }
2954 
2955   noprocess ();
2956 }
2957 
2958 static void
2959 debug_to_prepare_to_store (struct regcache *regcache)
2960 {
2961   debug_target.to_prepare_to_store (regcache);
2962 
2963   fprintf_unfiltered (gdb_stdlog, "target_prepare_to_store ()\n");
2964 }
2965 
2966 static int
2967 deprecated_debug_xfer_memory (CORE_ADDR memaddr, bfd_byte *myaddr, int len,
2968 			      int write, struct mem_attrib *attrib,
2969 			      struct target_ops *target)
2970 {
2971   int retval;
2972 
2973   retval = debug_target.deprecated_xfer_memory (memaddr, myaddr, len, write,
2974 						attrib, target);
2975 
2976   fprintf_unfiltered (gdb_stdlog,
2977 		      "target_xfer_memory (%s, xxx, %d, %s, xxx) = %d",
2978 		      paddress (target_gdbarch, memaddr), len,
2979 		      write ? "write" : "read", retval);
2980 
2981   if (retval > 0)
2982     {
2983       int i;
2984 
2985       fputs_unfiltered (", bytes =", gdb_stdlog);
2986       for (i = 0; i < retval; i++)
2987 	{
2988 	  if ((((intptr_t) &(myaddr[i])) & 0xf) == 0)
2989 	    {
2990 	      if (targetdebug < 2 && i > 0)
2991 		{
2992 		  fprintf_unfiltered (gdb_stdlog, " ...");
2993 		  break;
2994 		}
2995 	      fprintf_unfiltered (gdb_stdlog, "\n");
2996 	    }
2997 
2998 	  fprintf_unfiltered (gdb_stdlog, " %02x", myaddr[i] & 0xff);
2999 	}
3000     }
3001 
3002   fputc_unfiltered ('\n', gdb_stdlog);
3003 
3004   return retval;
3005 }
3006 
3007 static void
3008 debug_to_files_info (struct target_ops *target)
3009 {
3010   debug_target.to_files_info (target);
3011 
3012   fprintf_unfiltered (gdb_stdlog, "target_files_info (xxx)\n");
3013 }
3014 
3015 static int
3016 debug_to_insert_breakpoint (struct gdbarch *gdbarch,
3017 			    struct bp_target_info *bp_tgt)
3018 {
3019   int retval;
3020 
3021   retval = debug_target.to_insert_breakpoint (gdbarch, bp_tgt);
3022 
3023   fprintf_unfiltered (gdb_stdlog,
3024 		      "target_insert_breakpoint (0x%lx, xxx) = %ld\n",
3025 		      (unsigned long) bp_tgt->placed_address,
3026 		      (unsigned long) retval);
3027   return retval;
3028 }
3029 
3030 static int
3031 debug_to_remove_breakpoint (struct gdbarch *gdbarch,
3032 			    struct bp_target_info *bp_tgt)
3033 {
3034   int retval;
3035 
3036   retval = debug_target.to_remove_breakpoint (gdbarch, bp_tgt);
3037 
3038   fprintf_unfiltered (gdb_stdlog,
3039 		      "target_remove_breakpoint (0x%lx, xxx) = %ld\n",
3040 		      (unsigned long) bp_tgt->placed_address,
3041 		      (unsigned long) retval);
3042   return retval;
3043 }
3044 
3045 static int
3046 debug_to_can_use_hw_breakpoint (int type, int cnt, int from_tty)
3047 {
3048   int retval;
3049 
3050   retval = debug_target.to_can_use_hw_breakpoint (type, cnt, from_tty);
3051 
3052   fprintf_unfiltered (gdb_stdlog,
3053 		      "target_can_use_hw_breakpoint (%ld, %ld, %ld) = %ld\n",
3054 		      (unsigned long) type,
3055 		      (unsigned long) cnt,
3056 		      (unsigned long) from_tty,
3057 		      (unsigned long) retval);
3058   return retval;
3059 }
3060 
3061 static int
3062 debug_to_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
3063 {
3064   CORE_ADDR retval;
3065 
3066   retval = debug_target.to_region_ok_for_hw_watchpoint (addr, len);
3067 
3068   fprintf_unfiltered (gdb_stdlog,
3069 		      "target_region_ok_for_hw_watchpoint (%ld, %ld) = 0x%lx\n",
3070 		      (unsigned long) addr,
3071 		      (unsigned long) len,
3072 		      (unsigned long) retval);
3073   return retval;
3074 }
3075 
3076 static int
3077 debug_to_stopped_by_watchpoint (void)
3078 {
3079   int retval;
3080 
3081   retval = debug_target.to_stopped_by_watchpoint ();
3082 
3083   fprintf_unfiltered (gdb_stdlog,
3084 		      "target_stopped_by_watchpoint () = %ld\n",
3085 		      (unsigned long) retval);
3086   return retval;
3087 }
3088 
3089 static int
3090 debug_to_stopped_data_address (struct target_ops *target, CORE_ADDR *addr)
3091 {
3092   int retval;
3093 
3094   retval = debug_target.to_stopped_data_address (target, addr);
3095 
3096   fprintf_unfiltered (gdb_stdlog,
3097 		      "target_stopped_data_address ([0x%lx]) = %ld\n",
3098 		      (unsigned long)*addr,
3099 		      (unsigned long)retval);
3100   return retval;
3101 }
3102 
3103 static int
3104 debug_to_watchpoint_addr_within_range (struct target_ops *target,
3105 				       CORE_ADDR addr,
3106 				       CORE_ADDR start, int length)
3107 {
3108   int retval;
3109 
3110   retval = debug_target.to_watchpoint_addr_within_range (target, addr,
3111 							 start, length);
3112 
3113   fprintf_filtered (gdb_stdlog,
3114 		    "target_watchpoint_addr_within_range (0x%lx, 0x%lx, %d) = %d\n",
3115 		    (unsigned long) addr, (unsigned long) start, length,
3116 		    retval);
3117   return retval;
3118 }
3119 
3120 static int
3121 debug_to_insert_hw_breakpoint (struct gdbarch *gdbarch,
3122 			       struct bp_target_info *bp_tgt)
3123 {
3124   int retval;
3125 
3126   retval = debug_target.to_insert_hw_breakpoint (gdbarch, bp_tgt);
3127 
3128   fprintf_unfiltered (gdb_stdlog,
3129 		      "target_insert_hw_breakpoint (0x%lx, xxx) = %ld\n",
3130 		      (unsigned long) bp_tgt->placed_address,
3131 		      (unsigned long) retval);
3132   return retval;
3133 }
3134 
3135 static int
3136 debug_to_remove_hw_breakpoint (struct gdbarch *gdbarch,
3137 			       struct bp_target_info *bp_tgt)
3138 {
3139   int retval;
3140 
3141   retval = debug_target.to_remove_hw_breakpoint (gdbarch, bp_tgt);
3142 
3143   fprintf_unfiltered (gdb_stdlog,
3144 		      "target_remove_hw_breakpoint (0x%lx, xxx) = %ld\n",
3145 		      (unsigned long) bp_tgt->placed_address,
3146 		      (unsigned long) retval);
3147   return retval;
3148 }
3149 
3150 static int
3151 debug_to_insert_watchpoint (CORE_ADDR addr, int len, int type)
3152 {
3153   int retval;
3154 
3155   retval = debug_target.to_insert_watchpoint (addr, len, type);
3156 
3157   fprintf_unfiltered (gdb_stdlog,
3158 		      "target_insert_watchpoint (0x%lx, %d, %d) = %ld\n",
3159 		      (unsigned long) addr, len, type, (unsigned long) retval);
3160   return retval;
3161 }
3162 
3163 static int
3164 debug_to_remove_watchpoint (CORE_ADDR addr, int len, int type)
3165 {
3166   int retval;
3167 
3168   retval = debug_target.to_remove_watchpoint (addr, len, type);
3169 
3170   fprintf_unfiltered (gdb_stdlog,
3171 		      "target_remove_watchpoint (0x%lx, %d, %d) = %ld\n",
3172 		      (unsigned long) addr, len, type, (unsigned long) retval);
3173   return retval;
3174 }
3175 
3176 static void
3177 debug_to_terminal_init (void)
3178 {
3179   debug_target.to_terminal_init ();
3180 
3181   fprintf_unfiltered (gdb_stdlog, "target_terminal_init ()\n");
3182 }
3183 
3184 static void
3185 debug_to_terminal_inferior (void)
3186 {
3187   debug_target.to_terminal_inferior ();
3188 
3189   fprintf_unfiltered (gdb_stdlog, "target_terminal_inferior ()\n");
3190 }
3191 
3192 static void
3193 debug_to_terminal_ours_for_output (void)
3194 {
3195   debug_target.to_terminal_ours_for_output ();
3196 
3197   fprintf_unfiltered (gdb_stdlog, "target_terminal_ours_for_output ()\n");
3198 }
3199 
3200 static void
3201 debug_to_terminal_ours (void)
3202 {
3203   debug_target.to_terminal_ours ();
3204 
3205   fprintf_unfiltered (gdb_stdlog, "target_terminal_ours ()\n");
3206 }
3207 
3208 static void
3209 debug_to_terminal_save_ours (void)
3210 {
3211   debug_target.to_terminal_save_ours ();
3212 
3213   fprintf_unfiltered (gdb_stdlog, "target_terminal_save_ours ()\n");
3214 }
3215 
3216 static void
3217 debug_to_terminal_info (char *arg, int from_tty)
3218 {
3219   debug_target.to_terminal_info (arg, from_tty);
3220 
3221   fprintf_unfiltered (gdb_stdlog, "target_terminal_info (%s, %d)\n", arg,
3222 		      from_tty);
3223 }
3224 
3225 static void
3226 debug_to_load (char *args, int from_tty)
3227 {
3228   debug_target.to_load (args, from_tty);
3229 
3230   fprintf_unfiltered (gdb_stdlog, "target_load (%s, %d)\n", args, from_tty);
3231 }
3232 
3233 static int
3234 debug_to_lookup_symbol (char *name, CORE_ADDR *addrp)
3235 {
3236   int retval;
3237 
3238   retval = debug_target.to_lookup_symbol (name, addrp);
3239 
3240   fprintf_unfiltered (gdb_stdlog, "target_lookup_symbol (%s, xxx)\n", name);
3241 
3242   return retval;
3243 }
3244 
3245 static void
3246 debug_to_post_startup_inferior (ptid_t ptid)
3247 {
3248   debug_target.to_post_startup_inferior (ptid);
3249 
3250   fprintf_unfiltered (gdb_stdlog, "target_post_startup_inferior (%d)\n",
3251 		      PIDGET (ptid));
3252 }
3253 
3254 static void
3255 debug_to_acknowledge_created_inferior (int pid)
3256 {
3257   debug_target.to_acknowledge_created_inferior (pid);
3258 
3259   fprintf_unfiltered (gdb_stdlog, "target_acknowledge_created_inferior (%d)\n",
3260 		      pid);
3261 }
3262 
3263 static void
3264 debug_to_insert_fork_catchpoint (int pid)
3265 {
3266   debug_target.to_insert_fork_catchpoint (pid);
3267 
3268   fprintf_unfiltered (gdb_stdlog, "target_insert_fork_catchpoint (%d)\n",
3269 		      pid);
3270 }
3271 
3272 static int
3273 debug_to_remove_fork_catchpoint (int pid)
3274 {
3275   int retval;
3276 
3277   retval = debug_target.to_remove_fork_catchpoint (pid);
3278 
3279   fprintf_unfiltered (gdb_stdlog, "target_remove_fork_catchpoint (%d) = %d\n",
3280 		      pid, retval);
3281 
3282   return retval;
3283 }
3284 
3285 static void
3286 debug_to_insert_vfork_catchpoint (int pid)
3287 {
3288   debug_target.to_insert_vfork_catchpoint (pid);
3289 
3290   fprintf_unfiltered (gdb_stdlog, "target_insert_vfork_catchpoint (%d)\n",
3291 		      pid);
3292 }
3293 
3294 static int
3295 debug_to_remove_vfork_catchpoint (int pid)
3296 {
3297   int retval;
3298 
3299   retval = debug_target.to_remove_vfork_catchpoint (pid);
3300 
3301   fprintf_unfiltered (gdb_stdlog, "target_remove_vfork_catchpoint (%d) = %d\n",
3302 		      pid, retval);
3303 
3304   return retval;
3305 }
3306 
3307 static void
3308 debug_to_insert_exec_catchpoint (int pid)
3309 {
3310   debug_target.to_insert_exec_catchpoint (pid);
3311 
3312   fprintf_unfiltered (gdb_stdlog, "target_insert_exec_catchpoint (%d)\n",
3313 		      pid);
3314 }
3315 
3316 static int
3317 debug_to_remove_exec_catchpoint (int pid)
3318 {
3319   int retval;
3320 
3321   retval = debug_target.to_remove_exec_catchpoint (pid);
3322 
3323   fprintf_unfiltered (gdb_stdlog, "target_remove_exec_catchpoint (%d) = %d\n",
3324 		      pid, retval);
3325 
3326   return retval;
3327 }
3328 
3329 static int
3330 debug_to_has_exited (int pid, int wait_status, int *exit_status)
3331 {
3332   int has_exited;
3333 
3334   has_exited = debug_target.to_has_exited (pid, wait_status, exit_status);
3335 
3336   fprintf_unfiltered (gdb_stdlog, "target_has_exited (%d, %d, %d) = %d\n",
3337 		      pid, wait_status, *exit_status, has_exited);
3338 
3339   return has_exited;
3340 }
3341 
3342 static int
3343 debug_to_can_run (void)
3344 {
3345   int retval;
3346 
3347   retval = debug_target.to_can_run ();
3348 
3349   fprintf_unfiltered (gdb_stdlog, "target_can_run () = %d\n", retval);
3350 
3351   return retval;
3352 }
3353 
3354 static void
3355 debug_to_notice_signals (ptid_t ptid)
3356 {
3357   debug_target.to_notice_signals (ptid);
3358 
3359   fprintf_unfiltered (gdb_stdlog, "target_notice_signals (%d)\n",
3360                       PIDGET (ptid));
3361 }
3362 
3363 static struct gdbarch *
3364 debug_to_thread_architecture (struct target_ops *ops, ptid_t ptid)
3365 {
3366   struct gdbarch *retval;
3367 
3368   retval = debug_target.to_thread_architecture (ops, ptid);
3369 
3370   fprintf_unfiltered (gdb_stdlog, "target_thread_architecture (%s) = %p [%s]\n",
3371 		      target_pid_to_str (ptid), retval,
3372 		      gdbarch_bfd_arch_info (retval)->printable_name);
3373   return retval;
3374 }
3375 
3376 static void
3377 debug_to_stop (ptid_t ptid)
3378 {
3379   debug_target.to_stop (ptid);
3380 
3381   fprintf_unfiltered (gdb_stdlog, "target_stop (%s)\n",
3382 		      target_pid_to_str (ptid));
3383 }
3384 
3385 static void
3386 debug_to_rcmd (char *command,
3387 	       struct ui_file *outbuf)
3388 {
3389   debug_target.to_rcmd (command, outbuf);
3390   fprintf_unfiltered (gdb_stdlog, "target_rcmd (%s, ...)\n", command);
3391 }
3392 
3393 static char *
3394 debug_to_pid_to_exec_file (int pid)
3395 {
3396   char *exec_file;
3397 
3398   exec_file = debug_target.to_pid_to_exec_file (pid);
3399 
3400   fprintf_unfiltered (gdb_stdlog, "target_pid_to_exec_file (%d) = %s\n",
3401 		      pid, exec_file);
3402 
3403   return exec_file;
3404 }
3405 
3406 static void
3407 setup_target_debug (void)
3408 {
3409   memcpy (&debug_target, &current_target, sizeof debug_target);
3410 
3411   current_target.to_open = debug_to_open;
3412   current_target.to_post_attach = debug_to_post_attach;
3413   current_target.to_prepare_to_store = debug_to_prepare_to_store;
3414   current_target.deprecated_xfer_memory = deprecated_debug_xfer_memory;
3415   current_target.to_files_info = debug_to_files_info;
3416   current_target.to_insert_breakpoint = debug_to_insert_breakpoint;
3417   current_target.to_remove_breakpoint = debug_to_remove_breakpoint;
3418   current_target.to_can_use_hw_breakpoint = debug_to_can_use_hw_breakpoint;
3419   current_target.to_insert_hw_breakpoint = debug_to_insert_hw_breakpoint;
3420   current_target.to_remove_hw_breakpoint = debug_to_remove_hw_breakpoint;
3421   current_target.to_insert_watchpoint = debug_to_insert_watchpoint;
3422   current_target.to_remove_watchpoint = debug_to_remove_watchpoint;
3423   current_target.to_stopped_by_watchpoint = debug_to_stopped_by_watchpoint;
3424   current_target.to_stopped_data_address = debug_to_stopped_data_address;
3425   current_target.to_watchpoint_addr_within_range = debug_to_watchpoint_addr_within_range;
3426   current_target.to_region_ok_for_hw_watchpoint = debug_to_region_ok_for_hw_watchpoint;
3427   current_target.to_terminal_init = debug_to_terminal_init;
3428   current_target.to_terminal_inferior = debug_to_terminal_inferior;
3429   current_target.to_terminal_ours_for_output = debug_to_terminal_ours_for_output;
3430   current_target.to_terminal_ours = debug_to_terminal_ours;
3431   current_target.to_terminal_save_ours = debug_to_terminal_save_ours;
3432   current_target.to_terminal_info = debug_to_terminal_info;
3433   current_target.to_load = debug_to_load;
3434   current_target.to_lookup_symbol = debug_to_lookup_symbol;
3435   current_target.to_post_startup_inferior = debug_to_post_startup_inferior;
3436   current_target.to_acknowledge_created_inferior = debug_to_acknowledge_created_inferior;
3437   current_target.to_insert_fork_catchpoint = debug_to_insert_fork_catchpoint;
3438   current_target.to_remove_fork_catchpoint = debug_to_remove_fork_catchpoint;
3439   current_target.to_insert_vfork_catchpoint = debug_to_insert_vfork_catchpoint;
3440   current_target.to_remove_vfork_catchpoint = debug_to_remove_vfork_catchpoint;
3441   current_target.to_insert_exec_catchpoint = debug_to_insert_exec_catchpoint;
3442   current_target.to_remove_exec_catchpoint = debug_to_remove_exec_catchpoint;
3443   current_target.to_has_exited = debug_to_has_exited;
3444   current_target.to_can_run = debug_to_can_run;
3445   current_target.to_notice_signals = debug_to_notice_signals;
3446   current_target.to_stop = debug_to_stop;
3447   current_target.to_rcmd = debug_to_rcmd;
3448   current_target.to_pid_to_exec_file = debug_to_pid_to_exec_file;
3449   current_target.to_thread_architecture = debug_to_thread_architecture;
3450 }
3451 
3452 
3453 static char targ_desc[] =
3454 "Names of targets and files being debugged.\n\
3455 Shows the entire stack of targets currently in use (including the exec-file,\n\
3456 core-file, and process, if any), as well as the symbol file name.";
3457 
3458 static void
3459 do_monitor_command (char *cmd,
3460 		 int from_tty)
3461 {
3462   if ((current_target.to_rcmd
3463        == (void (*) (char *, struct ui_file *)) tcomplain)
3464       || (current_target.to_rcmd == debug_to_rcmd
3465 	  && (debug_target.to_rcmd
3466 	      == (void (*) (char *, struct ui_file *)) tcomplain)))
3467     error (_("\"monitor\" command not supported by this target."));
3468   target_rcmd (cmd, gdb_stdtarg);
3469 }
3470 
3471 /* Print the name of each layers of our target stack.  */
3472 
3473 static void
3474 maintenance_print_target_stack (char *cmd, int from_tty)
3475 {
3476   struct target_ops *t;
3477 
3478   printf_filtered (_("The current target stack is:\n"));
3479 
3480   for (t = target_stack; t != NULL; t = t->beneath)
3481     {
3482       printf_filtered ("  - %s (%s)\n", t->to_shortname, t->to_longname);
3483     }
3484 }
3485 
3486 /* Controls if async mode is permitted.  */
3487 int target_async_permitted = 0;
3488 
3489 /* The set command writes to this variable.  If the inferior is
3490    executing, linux_nat_async_permitted is *not* updated.  */
3491 static int target_async_permitted_1 = 0;
3492 
3493 static void
3494 set_maintenance_target_async_permitted (char *args, int from_tty,
3495 					struct cmd_list_element *c)
3496 {
3497   if (have_live_inferiors ())
3498     {
3499       target_async_permitted_1 = target_async_permitted;
3500       error (_("Cannot change this setting while the inferior is running."));
3501     }
3502 
3503   target_async_permitted = target_async_permitted_1;
3504 }
3505 
3506 static void
3507 show_maintenance_target_async_permitted (struct ui_file *file, int from_tty,
3508 					 struct cmd_list_element *c,
3509 					 const char *value)
3510 {
3511   fprintf_filtered (file, _("\
3512 Controlling the inferior in asynchronous mode is %s.\n"), value);
3513 }
3514 
3515 void
3516 initialize_targets (void)
3517 {
3518   init_dummy_target ();
3519   push_target (&dummy_target);
3520 
3521   add_info ("target", target_info, targ_desc);
3522   add_info ("files", target_info, targ_desc);
3523 
3524   add_setshow_zinteger_cmd ("target", class_maintenance, &targetdebug, _("\
3525 Set target debugging."), _("\
3526 Show target debugging."), _("\
3527 When non-zero, target debugging is enabled.  Higher numbers are more\n\
3528 verbose.  Changes do not take effect until the next \"run\" or \"target\"\n\
3529 command."),
3530 			    NULL,
3531 			    show_targetdebug,
3532 			    &setdebuglist, &showdebuglist);
3533 
3534   add_setshow_boolean_cmd ("trust-readonly-sections", class_support,
3535 			   &trust_readonly, _("\
3536 Set mode for reading from readonly sections."), _("\
3537 Show mode for reading from readonly sections."), _("\
3538 When this mode is on, memory reads from readonly sections (such as .text)\n\
3539 will be read from the object file instead of from the target.  This will\n\
3540 result in significant performance improvement for remote targets."),
3541 			   NULL,
3542 			   show_trust_readonly,
3543 			   &setlist, &showlist);
3544 
3545   add_com ("monitor", class_obscure, do_monitor_command,
3546 	   _("Send a command to the remote monitor (remote targets only)."));
3547 
3548   add_cmd ("target-stack", class_maintenance, maintenance_print_target_stack,
3549            _("Print the name of each layer of the internal target stack."),
3550            &maintenanceprintlist);
3551 
3552   add_setshow_boolean_cmd ("target-async", no_class,
3553 			   &target_async_permitted_1, _("\
3554 Set whether gdb controls the inferior in asynchronous mode."), _("\
3555 Show whether gdb controls the inferior in asynchronous mode."), _("\
3556 Tells gdb whether to control the inferior in asynchronous mode."),
3557 			   set_maintenance_target_async_permitted,
3558 			   show_maintenance_target_async_permitted,
3559 			   &setlist,
3560 			   &showlist);
3561 
3562   add_setshow_boolean_cmd ("stack-cache", class_support,
3563 			   &stack_cache_enabled_p_1, _("\
3564 Set cache use for stack access."), _("\
3565 Show cache use for stack access."), _("\
3566 When on, use the data cache for all stack access, regardless of any\n\
3567 configured memory regions.  This improves remote performance significantly.\n\
3568 By default, caching for stack access is on."),
3569 			   set_stack_cache_enabled_p,
3570 			   show_stack_cache_enabled_p,
3571 			   &setlist, &showlist);
3572 
3573   target_dcache = dcache_init ();
3574 }
3575