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[/] [openrisc/] [trunk/] [gnu-old/] [gdb-7.1/] [gdb/] [infrun.c] - Blame information for rev 825

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1 227 jeremybenn
/* Target-struct-independent code to start (run) and stop an inferior
2
   process.
3
 
4
   Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
5
   1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
6
   2008, 2009, 2010 Free Software Foundation, Inc.
7
 
8
   This file is part of GDB.
9
 
10
   This program is free software; you can redistribute it and/or modify
11
   it under the terms of the GNU General Public License as published by
12
   the Free Software Foundation; either version 3 of the License, or
13
   (at your option) any later version.
14
 
15
   This program is distributed in the hope that it will be useful,
16
   but WITHOUT ANY WARRANTY; without even the implied warranty of
17
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18
   GNU General Public License for more details.
19
 
20
   You should have received a copy of the GNU General Public License
21
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
22
 
23
#include "defs.h"
24
#include "gdb_string.h"
25
#include <ctype.h>
26
#include "symtab.h"
27
#include "frame.h"
28
#include "inferior.h"
29
#include "exceptions.h"
30
#include "breakpoint.h"
31
#include "gdb_wait.h"
32
#include "gdbcore.h"
33
#include "gdbcmd.h"
34
#include "cli/cli-script.h"
35
#include "target.h"
36
#include "gdbthread.h"
37
#include "annotate.h"
38
#include "symfile.h"
39
#include "top.h"
40
#include <signal.h>
41
#include "inf-loop.h"
42
#include "regcache.h"
43
#include "value.h"
44
#include "observer.h"
45
#include "language.h"
46
#include "solib.h"
47
#include "main.h"
48
#include "gdb_assert.h"
49
#include "mi/mi-common.h"
50
#include "event-top.h"
51
#include "record.h"
52
#include "inline-frame.h"
53
#include "jit.h"
54
#include "tracepoint.h"
55
 
56
/* Prototypes for local functions */
57
 
58
static void signals_info (char *, int);
59
 
60
static void handle_command (char *, int);
61
 
62
static void sig_print_info (enum target_signal);
63
 
64
static void sig_print_header (void);
65
 
66
static void resume_cleanups (void *);
67
 
68
static int hook_stop_stub (void *);
69
 
70
static int restore_selected_frame (void *);
71
 
72
static int follow_fork (void);
73
 
74
static void set_schedlock_func (char *args, int from_tty,
75
                                struct cmd_list_element *c);
76
 
77
static int currently_stepping (struct thread_info *tp);
78
 
79
static int currently_stepping_or_nexting_callback (struct thread_info *tp,
80
                                                   void *data);
81
 
82
static void xdb_handle_command (char *args, int from_tty);
83
 
84
static int prepare_to_proceed (int);
85
 
86
void _initialize_infrun (void);
87
 
88
void nullify_last_target_wait_ptid (void);
89
 
90
/* When set, stop the 'step' command if we enter a function which has
91
   no line number information.  The normal behavior is that we step
92
   over such function.  */
93
int step_stop_if_no_debug = 0;
94
static void
95
show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
96
                            struct cmd_list_element *c, const char *value)
97
{
98
  fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
99
}
100
 
101
/* In asynchronous mode, but simulating synchronous execution. */
102
 
103
int sync_execution = 0;
104
 
105
/* wait_for_inferior and normal_stop use this to notify the user
106
   when the inferior stopped in a different thread than it had been
107
   running in.  */
108
 
109
static ptid_t previous_inferior_ptid;
110
 
111
/* Default behavior is to detach newly forked processes (legacy).  */
112
int detach_fork = 1;
113
 
114
int debug_displaced = 0;
115
static void
116
show_debug_displaced (struct ui_file *file, int from_tty,
117
                      struct cmd_list_element *c, const char *value)
118
{
119
  fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
120
}
121
 
122
static int debug_infrun = 0;
123
static void
124
show_debug_infrun (struct ui_file *file, int from_tty,
125
                   struct cmd_list_element *c, const char *value)
126
{
127
  fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
128
}
129
 
130
/* If the program uses ELF-style shared libraries, then calls to
131
   functions in shared libraries go through stubs, which live in a
132
   table called the PLT (Procedure Linkage Table).  The first time the
133
   function is called, the stub sends control to the dynamic linker,
134
   which looks up the function's real address, patches the stub so
135
   that future calls will go directly to the function, and then passes
136
   control to the function.
137
 
138
   If we are stepping at the source level, we don't want to see any of
139
   this --- we just want to skip over the stub and the dynamic linker.
140
   The simple approach is to single-step until control leaves the
141
   dynamic linker.
142
 
143
   However, on some systems (e.g., Red Hat's 5.2 distribution) the
144
   dynamic linker calls functions in the shared C library, so you
145
   can't tell from the PC alone whether the dynamic linker is still
146
   running.  In this case, we use a step-resume breakpoint to get us
147
   past the dynamic linker, as if we were using "next" to step over a
148
   function call.
149
 
150
   in_solib_dynsym_resolve_code() says whether we're in the dynamic
151
   linker code or not.  Normally, this means we single-step.  However,
152
   if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
153
   address where we can place a step-resume breakpoint to get past the
154
   linker's symbol resolution function.
155
 
156
   in_solib_dynsym_resolve_code() can generally be implemented in a
157
   pretty portable way, by comparing the PC against the address ranges
158
   of the dynamic linker's sections.
159
 
160
   SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
161
   it depends on internal details of the dynamic linker.  It's usually
162
   not too hard to figure out where to put a breakpoint, but it
163
   certainly isn't portable.  SKIP_SOLIB_RESOLVER should do plenty of
164
   sanity checking.  If it can't figure things out, returning zero and
165
   getting the (possibly confusing) stepping behavior is better than
166
   signalling an error, which will obscure the change in the
167
   inferior's state.  */
168
 
169
/* This function returns TRUE if pc is the address of an instruction
170
   that lies within the dynamic linker (such as the event hook, or the
171
   dld itself).
172
 
173
   This function must be used only when a dynamic linker event has
174
   been caught, and the inferior is being stepped out of the hook, or
175
   undefined results are guaranteed.  */
176
 
177
#ifndef SOLIB_IN_DYNAMIC_LINKER
178
#define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
179
#endif
180
 
181
 
182
/* Convert the #defines into values.  This is temporary until wfi control
183
   flow is completely sorted out.  */
184
 
185
#ifndef CANNOT_STEP_HW_WATCHPOINTS
186
#define CANNOT_STEP_HW_WATCHPOINTS 0
187
#else
188
#undef  CANNOT_STEP_HW_WATCHPOINTS
189
#define CANNOT_STEP_HW_WATCHPOINTS 1
190
#endif
191
 
192
/* Tables of how to react to signals; the user sets them.  */
193
 
194
static unsigned char *signal_stop;
195
static unsigned char *signal_print;
196
static unsigned char *signal_program;
197
 
198
#define SET_SIGS(nsigs,sigs,flags) \
199
  do { \
200
    int signum = (nsigs); \
201
    while (signum-- > 0) \
202
      if ((sigs)[signum]) \
203
        (flags)[signum] = 1; \
204
  } while (0)
205
 
206
#define UNSET_SIGS(nsigs,sigs,flags) \
207
  do { \
208
    int signum = (nsigs); \
209
    while (signum-- > 0) \
210
      if ((sigs)[signum]) \
211
        (flags)[signum] = 0; \
212
  } while (0)
213
 
214
/* Value to pass to target_resume() to cause all threads to resume */
215
 
216
#define RESUME_ALL minus_one_ptid
217
 
218
/* Command list pointer for the "stop" placeholder.  */
219
 
220
static struct cmd_list_element *stop_command;
221
 
222
/* Function inferior was in as of last step command.  */
223
 
224
static struct symbol *step_start_function;
225
 
226
/* Nonzero if we want to give control to the user when we're notified
227
   of shared library events by the dynamic linker.  */
228
static int stop_on_solib_events;
229
static void
230
show_stop_on_solib_events (struct ui_file *file, int from_tty,
231
                           struct cmd_list_element *c, const char *value)
232
{
233
  fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
234
                    value);
235
}
236
 
237
/* Nonzero means expecting a trace trap
238
   and should stop the inferior and return silently when it happens.  */
239
 
240
int stop_after_trap;
241
 
242
/* Save register contents here when executing a "finish" command or are
243
   about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
244
   Thus this contains the return value from the called function (assuming
245
   values are returned in a register).  */
246
 
247
struct regcache *stop_registers;
248
 
249
/* Nonzero after stop if current stack frame should be printed.  */
250
 
251
static int stop_print_frame;
252
 
253
/* This is a cached copy of the pid/waitstatus of the last event
254
   returned by target_wait()/deprecated_target_wait_hook().  This
255
   information is returned by get_last_target_status().  */
256
static ptid_t target_last_wait_ptid;
257
static struct target_waitstatus target_last_waitstatus;
258
 
259
static void context_switch (ptid_t ptid);
260
 
261
void init_thread_stepping_state (struct thread_info *tss);
262
 
263
void init_infwait_state (void);
264
 
265
static const char follow_fork_mode_child[] = "child";
266
static const char follow_fork_mode_parent[] = "parent";
267
 
268
static const char *follow_fork_mode_kind_names[] = {
269
  follow_fork_mode_child,
270
  follow_fork_mode_parent,
271
  NULL
272
};
273
 
274
static const char *follow_fork_mode_string = follow_fork_mode_parent;
275
static void
276
show_follow_fork_mode_string (struct ui_file *file, int from_tty,
277
                              struct cmd_list_element *c, const char *value)
278
{
279
  fprintf_filtered (file, _("\
280
Debugger response to a program call of fork or vfork is \"%s\".\n"),
281
                    value);
282
}
283
 
284
 
285
/* Tell the target to follow the fork we're stopped at.  Returns true
286
   if the inferior should be resumed; false, if the target for some
287
   reason decided it's best not to resume.  */
288
 
289
static int
290
follow_fork (void)
291
{
292
  int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
293
  int should_resume = 1;
294
  struct thread_info *tp;
295
 
296
  /* Copy user stepping state to the new inferior thread.  FIXME: the
297
     followed fork child thread should have a copy of most of the
298
     parent thread structure's run control related fields, not just these.
299
     Initialized to avoid "may be used uninitialized" warnings from gcc.  */
300
  struct breakpoint *step_resume_breakpoint = NULL;
301
  CORE_ADDR step_range_start = 0;
302
  CORE_ADDR step_range_end = 0;
303
  struct frame_id step_frame_id = { 0 };
304
 
305
  if (!non_stop)
306
    {
307
      ptid_t wait_ptid;
308
      struct target_waitstatus wait_status;
309
 
310
      /* Get the last target status returned by target_wait().  */
311
      get_last_target_status (&wait_ptid, &wait_status);
312
 
313
      /* If not stopped at a fork event, then there's nothing else to
314
         do.  */
315
      if (wait_status.kind != TARGET_WAITKIND_FORKED
316
          && wait_status.kind != TARGET_WAITKIND_VFORKED)
317
        return 1;
318
 
319
      /* Check if we switched over from WAIT_PTID, since the event was
320
         reported.  */
321
      if (!ptid_equal (wait_ptid, minus_one_ptid)
322
          && !ptid_equal (inferior_ptid, wait_ptid))
323
        {
324
          /* We did.  Switch back to WAIT_PTID thread, to tell the
325
             target to follow it (in either direction).  We'll
326
             afterwards refuse to resume, and inform the user what
327
             happened.  */
328
          switch_to_thread (wait_ptid);
329
          should_resume = 0;
330
        }
331
    }
332
 
333
  tp = inferior_thread ();
334
 
335
  /* If there were any forks/vforks that were caught and are now to be
336
     followed, then do so now.  */
337
  switch (tp->pending_follow.kind)
338
    {
339
    case TARGET_WAITKIND_FORKED:
340
    case TARGET_WAITKIND_VFORKED:
341
      {
342
        ptid_t parent, child;
343
 
344
        /* If the user did a next/step, etc, over a fork call,
345
           preserve the stepping state in the fork child.  */
346
        if (follow_child && should_resume)
347
          {
348
            step_resume_breakpoint
349
              = clone_momentary_breakpoint (tp->step_resume_breakpoint);
350
            step_range_start = tp->step_range_start;
351
            step_range_end = tp->step_range_end;
352
            step_frame_id = tp->step_frame_id;
353
 
354
            /* For now, delete the parent's sr breakpoint, otherwise,
355
               parent/child sr breakpoints are considered duplicates,
356
               and the child version will not be installed.  Remove
357
               this when the breakpoints module becomes aware of
358
               inferiors and address spaces.  */
359
            delete_step_resume_breakpoint (tp);
360
            tp->step_range_start = 0;
361
            tp->step_range_end = 0;
362
            tp->step_frame_id = null_frame_id;
363
          }
364
 
365
        parent = inferior_ptid;
366
        child = tp->pending_follow.value.related_pid;
367
 
368
        /* Tell the target to do whatever is necessary to follow
369
           either parent or child.  */
370
        if (target_follow_fork (follow_child))
371
          {
372
            /* Target refused to follow, or there's some other reason
373
               we shouldn't resume.  */
374
            should_resume = 0;
375
          }
376
        else
377
          {
378
            /* This pending follow fork event is now handled, one way
379
               or another.  The previous selected thread may be gone
380
               from the lists by now, but if it is still around, need
381
               to clear the pending follow request.  */
382
            tp = find_thread_ptid (parent);
383
            if (tp)
384
              tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
385
 
386
            /* This makes sure we don't try to apply the "Switched
387
               over from WAIT_PID" logic above.  */
388
            nullify_last_target_wait_ptid ();
389
 
390
            /* If we followed the child, switch to it... */
391
            if (follow_child)
392
              {
393
                switch_to_thread (child);
394
 
395
                /* ... and preserve the stepping state, in case the
396
                   user was stepping over the fork call.  */
397
                if (should_resume)
398
                  {
399
                    tp = inferior_thread ();
400
                    tp->step_resume_breakpoint = step_resume_breakpoint;
401
                    tp->step_range_start = step_range_start;
402
                    tp->step_range_end = step_range_end;
403
                    tp->step_frame_id = step_frame_id;
404
                  }
405
                else
406
                  {
407
                    /* If we get here, it was because we're trying to
408
                       resume from a fork catchpoint, but, the user
409
                       has switched threads away from the thread that
410
                       forked.  In that case, the resume command
411
                       issued is most likely not applicable to the
412
                       child, so just warn, and refuse to resume.  */
413
                    warning (_("\
414
Not resuming: switched threads before following fork child.\n"));
415
                  }
416
 
417
                /* Reset breakpoints in the child as appropriate.  */
418
                follow_inferior_reset_breakpoints ();
419
              }
420
            else
421
              switch_to_thread (parent);
422
          }
423
      }
424
      break;
425
    case TARGET_WAITKIND_SPURIOUS:
426
      /* Nothing to follow.  */
427
      break;
428
    default:
429
      internal_error (__FILE__, __LINE__,
430
                      "Unexpected pending_follow.kind %d\n",
431
                      tp->pending_follow.kind);
432
      break;
433
    }
434
 
435
  return should_resume;
436
}
437
 
438
void
439
follow_inferior_reset_breakpoints (void)
440
{
441
  struct thread_info *tp = inferior_thread ();
442
 
443
  /* Was there a step_resume breakpoint?  (There was if the user
444
     did a "next" at the fork() call.)  If so, explicitly reset its
445
     thread number.
446
 
447
     step_resumes are a form of bp that are made to be per-thread.
448
     Since we created the step_resume bp when the parent process
449
     was being debugged, and now are switching to the child process,
450
     from the breakpoint package's viewpoint, that's a switch of
451
     "threads".  We must update the bp's notion of which thread
452
     it is for, or it'll be ignored when it triggers.  */
453
 
454
  if (tp->step_resume_breakpoint)
455
    breakpoint_re_set_thread (tp->step_resume_breakpoint);
456
 
457
  /* Reinsert all breakpoints in the child.  The user may have set
458
     breakpoints after catching the fork, in which case those
459
     were never set in the child, but only in the parent.  This makes
460
     sure the inserted breakpoints match the breakpoint list.  */
461
 
462
  breakpoint_re_set ();
463
  insert_breakpoints ();
464
}
465
 
466
/* The child has exited or execed: resume threads of the parent the
467
   user wanted to be executing.  */
468
 
469
static int
470
proceed_after_vfork_done (struct thread_info *thread,
471
                          void *arg)
472
{
473
  int pid = * (int *) arg;
474
 
475
  if (ptid_get_pid (thread->ptid) == pid
476
      && is_running (thread->ptid)
477
      && !is_executing (thread->ptid)
478
      && !thread->stop_requested
479
      && thread->stop_signal == TARGET_SIGNAL_0)
480
    {
481
      if (debug_infrun)
482
        fprintf_unfiltered (gdb_stdlog,
483
                            "infrun: resuming vfork parent thread %s\n",
484
                            target_pid_to_str (thread->ptid));
485
 
486
      switch_to_thread (thread->ptid);
487
      clear_proceed_status ();
488
      proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
489
    }
490
 
491
  return 0;
492
}
493
 
494
/* Called whenever we notice an exec or exit event, to handle
495
   detaching or resuming a vfork parent.  */
496
 
497
static void
498
handle_vfork_child_exec_or_exit (int exec)
499
{
500
  struct inferior *inf = current_inferior ();
501
 
502
  if (inf->vfork_parent)
503
    {
504
      int resume_parent = -1;
505
 
506
      /* This exec or exit marks the end of the shared memory region
507
         between the parent and the child.  If the user wanted to
508
         detach from the parent, now is the time.  */
509
 
510
      if (inf->vfork_parent->pending_detach)
511
        {
512
          struct thread_info *tp;
513
          struct cleanup *old_chain;
514
          struct program_space *pspace;
515
          struct address_space *aspace;
516
 
517
          /* follow-fork child, detach-on-fork on */
518
 
519
          old_chain = make_cleanup_restore_current_thread ();
520
 
521
          /* We're letting loose of the parent.  */
522
          tp = any_live_thread_of_process (inf->vfork_parent->pid);
523
          switch_to_thread (tp->ptid);
524
 
525
          /* We're about to detach from the parent, which implicitly
526
             removes breakpoints from its address space.  There's a
527
             catch here: we want to reuse the spaces for the child,
528
             but, parent/child are still sharing the pspace at this
529
             point, although the exec in reality makes the kernel give
530
             the child a fresh set of new pages.  The problem here is
531
             that the breakpoints module being unaware of this, would
532
             likely chose the child process to write to the parent
533
             address space.  Swapping the child temporarily away from
534
             the spaces has the desired effect.  Yes, this is "sort
535
             of" a hack.  */
536
 
537
          pspace = inf->pspace;
538
          aspace = inf->aspace;
539
          inf->aspace = NULL;
540
          inf->pspace = NULL;
541
 
542
          if (debug_infrun || info_verbose)
543
            {
544
              target_terminal_ours ();
545
 
546
              if (exec)
547
                fprintf_filtered (gdb_stdlog,
548
                                  "Detaching vfork parent process %d after child exec.\n",
549
                                  inf->vfork_parent->pid);
550
              else
551
                fprintf_filtered (gdb_stdlog,
552
                                  "Detaching vfork parent process %d after child exit.\n",
553
                                  inf->vfork_parent->pid);
554
            }
555
 
556
          target_detach (NULL, 0);
557
 
558
          /* Put it back.  */
559
          inf->pspace = pspace;
560
          inf->aspace = aspace;
561
 
562
          do_cleanups (old_chain);
563
        }
564
      else if (exec)
565
        {
566
          /* We're staying attached to the parent, so, really give the
567
             child a new address space.  */
568
          inf->pspace = add_program_space (maybe_new_address_space ());
569
          inf->aspace = inf->pspace->aspace;
570
          inf->removable = 1;
571
          set_current_program_space (inf->pspace);
572
 
573
          resume_parent = inf->vfork_parent->pid;
574
 
575
          /* Break the bonds.  */
576
          inf->vfork_parent->vfork_child = NULL;
577
        }
578
      else
579
        {
580
          struct cleanup *old_chain;
581
          struct program_space *pspace;
582
 
583
          /* If this is a vfork child exiting, then the pspace and
584
             aspaces were shared with the parent.  Since we're
585
             reporting the process exit, we'll be mourning all that is
586
             found in the address space, and switching to null_ptid,
587
             preparing to start a new inferior.  But, since we don't
588
             want to clobber the parent's address/program spaces, we
589
             go ahead and create a new one for this exiting
590
             inferior.  */
591
 
592
          /* Switch to null_ptid, so that clone_program_space doesn't want
593
             to read the selected frame of a dead process.  */
594
          old_chain = save_inferior_ptid ();
595
          inferior_ptid = null_ptid;
596
 
597
          /* This inferior is dead, so avoid giving the breakpoints
598
             module the option to write through to it (cloning a
599
             program space resets breakpoints).  */
600
          inf->aspace = NULL;
601
          inf->pspace = NULL;
602
          pspace = add_program_space (maybe_new_address_space ());
603
          set_current_program_space (pspace);
604
          inf->removable = 1;
605
          clone_program_space (pspace, inf->vfork_parent->pspace);
606
          inf->pspace = pspace;
607
          inf->aspace = pspace->aspace;
608
 
609
          /* Put back inferior_ptid.  We'll continue mourning this
610
             inferior. */
611
          do_cleanups (old_chain);
612
 
613
          resume_parent = inf->vfork_parent->pid;
614
          /* Break the bonds.  */
615
          inf->vfork_parent->vfork_child = NULL;
616
        }
617
 
618
      inf->vfork_parent = NULL;
619
 
620
      gdb_assert (current_program_space == inf->pspace);
621
 
622
      if (non_stop && resume_parent != -1)
623
        {
624
          /* If the user wanted the parent to be running, let it go
625
             free now.  */
626
          struct cleanup *old_chain = make_cleanup_restore_current_thread ();
627
 
628
          if (debug_infrun)
629
            fprintf_unfiltered (gdb_stdlog, "infrun: resuming vfork parent process %d\n",
630
                                resume_parent);
631
 
632
          iterate_over_threads (proceed_after_vfork_done, &resume_parent);
633
 
634
          do_cleanups (old_chain);
635
        }
636
    }
637
}
638
 
639
/* Enum strings for "set|show displaced-stepping".  */
640
 
641
static const char follow_exec_mode_new[] = "new";
642
static const char follow_exec_mode_same[] = "same";
643
static const char *follow_exec_mode_names[] =
644
{
645
  follow_exec_mode_new,
646
  follow_exec_mode_same,
647
  NULL,
648
};
649
 
650
static const char *follow_exec_mode_string = follow_exec_mode_same;
651
static void
652
show_follow_exec_mode_string (struct ui_file *file, int from_tty,
653
                              struct cmd_list_element *c, const char *value)
654
{
655
  fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"),  value);
656
}
657
 
658
/* EXECD_PATHNAME is assumed to be non-NULL. */
659
 
660
static void
661
follow_exec (ptid_t pid, char *execd_pathname)
662
{
663
  struct target_ops *tgt;
664
  struct thread_info *th = inferior_thread ();
665
  struct inferior *inf = current_inferior ();
666
 
667
  /* This is an exec event that we actually wish to pay attention to.
668
     Refresh our symbol table to the newly exec'd program, remove any
669
     momentary bp's, etc.
670
 
671
     If there are breakpoints, they aren't really inserted now,
672
     since the exec() transformed our inferior into a fresh set
673
     of instructions.
674
 
675
     We want to preserve symbolic breakpoints on the list, since
676
     we have hopes that they can be reset after the new a.out's
677
     symbol table is read.
678
 
679
     However, any "raw" breakpoints must be removed from the list
680
     (e.g., the solib bp's), since their address is probably invalid
681
     now.
682
 
683
     And, we DON'T want to call delete_breakpoints() here, since
684
     that may write the bp's "shadow contents" (the instruction
685
     value that was overwritten witha TRAP instruction).  Since
686
     we now have a new a.out, those shadow contents aren't valid. */
687
 
688
  mark_breakpoints_out ();
689
 
690
  update_breakpoints_after_exec ();
691
 
692
  /* If there was one, it's gone now.  We cannot truly step-to-next
693
     statement through an exec(). */
694
  th->step_resume_breakpoint = NULL;
695
  th->step_range_start = 0;
696
  th->step_range_end = 0;
697
 
698
  /* The target reports the exec event to the main thread, even if
699
     some other thread does the exec, and even if the main thread was
700
     already stopped --- if debugging in non-stop mode, it's possible
701
     the user had the main thread held stopped in the previous image
702
     --- release it now.  This is the same behavior as step-over-exec
703
     with scheduler-locking on in all-stop mode.  */
704
  th->stop_requested = 0;
705
 
706
  /* What is this a.out's name? */
707
  printf_unfiltered (_("%s is executing new program: %s\n"),
708
                     target_pid_to_str (inferior_ptid),
709
                     execd_pathname);
710
 
711
  /* We've followed the inferior through an exec.  Therefore, the
712
     inferior has essentially been killed & reborn. */
713
 
714
  gdb_flush (gdb_stdout);
715
 
716
  breakpoint_init_inferior (inf_execd);
717
 
718
  if (gdb_sysroot && *gdb_sysroot)
719
    {
720
      char *name = alloca (strlen (gdb_sysroot)
721
                            + strlen (execd_pathname)
722
                            + 1);
723
      strcpy (name, gdb_sysroot);
724
      strcat (name, execd_pathname);
725
      execd_pathname = name;
726
    }
727
 
728
  /* Reset the shared library package.  This ensures that we get a
729
     shlib event when the child reaches "_start", at which point the
730
     dld will have had a chance to initialize the child.  */
731
  /* Also, loading a symbol file below may trigger symbol lookups, and
732
     we don't want those to be satisfied by the libraries of the
733
     previous incarnation of this process.  */
734
  no_shared_libraries (NULL, 0);
735
 
736
  if (follow_exec_mode_string == follow_exec_mode_new)
737
    {
738
      struct program_space *pspace;
739
      struct inferior *new_inf;
740
 
741
      /* The user wants to keep the old inferior and program spaces
742
         around.  Create a new fresh one, and switch to it.  */
743
 
744
      inf = add_inferior (current_inferior ()->pid);
745
      pspace = add_program_space (maybe_new_address_space ());
746
      inf->pspace = pspace;
747
      inf->aspace = pspace->aspace;
748
 
749
      exit_inferior_num_silent (current_inferior ()->num);
750
 
751
      set_current_inferior (inf);
752
      set_current_program_space (pspace);
753
    }
754
 
755
  gdb_assert (current_program_space == inf->pspace);
756
 
757
  /* That a.out is now the one to use. */
758
  exec_file_attach (execd_pathname, 0);
759
 
760
  /* Load the main file's symbols.  */
761
  symbol_file_add_main (execd_pathname, 0);
762
 
763
#ifdef SOLIB_CREATE_INFERIOR_HOOK
764
  SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
765
#else
766
  solib_create_inferior_hook (0);
767
#endif
768
 
769
  jit_inferior_created_hook ();
770
 
771
  /* Reinsert all breakpoints.  (Those which were symbolic have
772
     been reset to the proper address in the new a.out, thanks
773
     to symbol_file_command...) */
774
  insert_breakpoints ();
775
 
776
  /* The next resume of this inferior should bring it to the shlib
777
     startup breakpoints.  (If the user had also set bp's on
778
     "main" from the old (parent) process, then they'll auto-
779
     matically get reset there in the new process.) */
780
}
781
 
782
/* Non-zero if we just simulating a single-step.  This is needed
783
   because we cannot remove the breakpoints in the inferior process
784
   until after the `wait' in `wait_for_inferior'.  */
785
static int singlestep_breakpoints_inserted_p = 0;
786
 
787
/* The thread we inserted single-step breakpoints for.  */
788
static ptid_t singlestep_ptid;
789
 
790
/* PC when we started this single-step.  */
791
static CORE_ADDR singlestep_pc;
792
 
793
/* If another thread hit the singlestep breakpoint, we save the original
794
   thread here so that we can resume single-stepping it later.  */
795
static ptid_t saved_singlestep_ptid;
796
static int stepping_past_singlestep_breakpoint;
797
 
798
/* If not equal to null_ptid, this means that after stepping over breakpoint
799
   is finished, we need to switch to deferred_step_ptid, and step it.
800
 
801
   The use case is when one thread has hit a breakpoint, and then the user
802
   has switched to another thread and issued 'step'. We need to step over
803
   breakpoint in the thread which hit the breakpoint, but then continue
804
   stepping the thread user has selected.  */
805
static ptid_t deferred_step_ptid;
806
 
807
/* Displaced stepping.  */
808
 
809
/* In non-stop debugging mode, we must take special care to manage
810
   breakpoints properly; in particular, the traditional strategy for
811
   stepping a thread past a breakpoint it has hit is unsuitable.
812
   'Displaced stepping' is a tactic for stepping one thread past a
813
   breakpoint it has hit while ensuring that other threads running
814
   concurrently will hit the breakpoint as they should.
815
 
816
   The traditional way to step a thread T off a breakpoint in a
817
   multi-threaded program in all-stop mode is as follows:
818
 
819
   a0) Initially, all threads are stopped, and breakpoints are not
820
       inserted.
821
   a1) We single-step T, leaving breakpoints uninserted.
822
   a2) We insert breakpoints, and resume all threads.
823
 
824
   In non-stop debugging, however, this strategy is unsuitable: we
825
   don't want to have to stop all threads in the system in order to
826
   continue or step T past a breakpoint.  Instead, we use displaced
827
   stepping:
828
 
829
   n0) Initially, T is stopped, other threads are running, and
830
       breakpoints are inserted.
831
   n1) We copy the instruction "under" the breakpoint to a separate
832
       location, outside the main code stream, making any adjustments
833
       to the instruction, register, and memory state as directed by
834
       T's architecture.
835
   n2) We single-step T over the instruction at its new location.
836
   n3) We adjust the resulting register and memory state as directed
837
       by T's architecture.  This includes resetting T's PC to point
838
       back into the main instruction stream.
839
   n4) We resume T.
840
 
841
   This approach depends on the following gdbarch methods:
842
 
843
   - gdbarch_max_insn_length and gdbarch_displaced_step_location
844
     indicate where to copy the instruction, and how much space must
845
     be reserved there.  We use these in step n1.
846
 
847
   - gdbarch_displaced_step_copy_insn copies a instruction to a new
848
     address, and makes any necessary adjustments to the instruction,
849
     register contents, and memory.  We use this in step n1.
850
 
851
   - gdbarch_displaced_step_fixup adjusts registers and memory after
852
     we have successfuly single-stepped the instruction, to yield the
853
     same effect the instruction would have had if we had executed it
854
     at its original address.  We use this in step n3.
855
 
856
   - gdbarch_displaced_step_free_closure provides cleanup.
857
 
858
   The gdbarch_displaced_step_copy_insn and
859
   gdbarch_displaced_step_fixup functions must be written so that
860
   copying an instruction with gdbarch_displaced_step_copy_insn,
861
   single-stepping across the copied instruction, and then applying
862
   gdbarch_displaced_insn_fixup should have the same effects on the
863
   thread's memory and registers as stepping the instruction in place
864
   would have.  Exactly which responsibilities fall to the copy and
865
   which fall to the fixup is up to the author of those functions.
866
 
867
   See the comments in gdbarch.sh for details.
868
 
869
   Note that displaced stepping and software single-step cannot
870
   currently be used in combination, although with some care I think
871
   they could be made to.  Software single-step works by placing
872
   breakpoints on all possible subsequent instructions; if the
873
   displaced instruction is a PC-relative jump, those breakpoints
874
   could fall in very strange places --- on pages that aren't
875
   executable, or at addresses that are not proper instruction
876
   boundaries.  (We do generally let other threads run while we wait
877
   to hit the software single-step breakpoint, and they might
878
   encounter such a corrupted instruction.)  One way to work around
879
   this would be to have gdbarch_displaced_step_copy_insn fully
880
   simulate the effect of PC-relative instructions (and return NULL)
881
   on architectures that use software single-stepping.
882
 
883
   In non-stop mode, we can have independent and simultaneous step
884
   requests, so more than one thread may need to simultaneously step
885
   over a breakpoint.  The current implementation assumes there is
886
   only one scratch space per process.  In this case, we have to
887
   serialize access to the scratch space.  If thread A wants to step
888
   over a breakpoint, but we are currently waiting for some other
889
   thread to complete a displaced step, we leave thread A stopped and
890
   place it in the displaced_step_request_queue.  Whenever a displaced
891
   step finishes, we pick the next thread in the queue and start a new
892
   displaced step operation on it.  See displaced_step_prepare and
893
   displaced_step_fixup for details.  */
894
 
895
/* If this is not null_ptid, this is the thread carrying out a
896
   displaced single-step.  This thread's state will require fixing up
897
   once it has completed its step.  */
898
static ptid_t displaced_step_ptid;
899
 
900
struct displaced_step_request
901
{
902
  ptid_t ptid;
903
  struct displaced_step_request *next;
904
};
905
 
906
/* A queue of pending displaced stepping requests.  */
907
struct displaced_step_request *displaced_step_request_queue;
908
 
909
/* The architecture the thread had when we stepped it.  */
910
static struct gdbarch *displaced_step_gdbarch;
911
 
912
/* The closure provided gdbarch_displaced_step_copy_insn, to be used
913
   for post-step cleanup.  */
914
static struct displaced_step_closure *displaced_step_closure;
915
 
916
/* The address of the original instruction, and the copy we made.  */
917
static CORE_ADDR displaced_step_original, displaced_step_copy;
918
 
919
/* Saved contents of copy area.  */
920
static gdb_byte *displaced_step_saved_copy;
921
 
922
/* Enum strings for "set|show displaced-stepping".  */
923
 
924
static const char can_use_displaced_stepping_auto[] = "auto";
925
static const char can_use_displaced_stepping_on[] = "on";
926
static const char can_use_displaced_stepping_off[] = "off";
927
static const char *can_use_displaced_stepping_enum[] =
928
{
929
  can_use_displaced_stepping_auto,
930
  can_use_displaced_stepping_on,
931
  can_use_displaced_stepping_off,
932
  NULL,
933
};
934
 
935
/* If ON, and the architecture supports it, GDB will use displaced
936
   stepping to step over breakpoints.  If OFF, or if the architecture
937
   doesn't support it, GDB will instead use the traditional
938
   hold-and-step approach.  If AUTO (which is the default), GDB will
939
   decide which technique to use to step over breakpoints depending on
940
   which of all-stop or non-stop mode is active --- displaced stepping
941
   in non-stop mode; hold-and-step in all-stop mode.  */
942
 
943
static const char *can_use_displaced_stepping =
944
  can_use_displaced_stepping_auto;
945
 
946
static void
947
show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
948
                                 struct cmd_list_element *c,
949
                                 const char *value)
950
{
951
  if (can_use_displaced_stepping == can_use_displaced_stepping_auto)
952
    fprintf_filtered (file, _("\
953
Debugger's willingness to use displaced stepping to step over \
954
breakpoints is %s (currently %s).\n"),
955
                      value, non_stop ? "on" : "off");
956
  else
957
    fprintf_filtered (file, _("\
958
Debugger's willingness to use displaced stepping to step over \
959
breakpoints is %s.\n"), value);
960
}
961
 
962
/* Return non-zero if displaced stepping can/should be used to step
963
   over breakpoints.  */
964
 
965
static int
966
use_displaced_stepping (struct gdbarch *gdbarch)
967
{
968
  return (((can_use_displaced_stepping == can_use_displaced_stepping_auto
969
            && non_stop)
970
           || can_use_displaced_stepping == can_use_displaced_stepping_on)
971
          && gdbarch_displaced_step_copy_insn_p (gdbarch)
972
          && !RECORD_IS_USED);
973
}
974
 
975
/* Clean out any stray displaced stepping state.  */
976
static void
977
displaced_step_clear (void)
978
{
979
  /* Indicate that there is no cleanup pending.  */
980
  displaced_step_ptid = null_ptid;
981
 
982
  if (displaced_step_closure)
983
    {
984
      gdbarch_displaced_step_free_closure (displaced_step_gdbarch,
985
                                           displaced_step_closure);
986
      displaced_step_closure = NULL;
987
    }
988
}
989
 
990
static void
991
displaced_step_clear_cleanup (void *ignore)
992
{
993
  displaced_step_clear ();
994
}
995
 
996
/* Dump LEN bytes at BUF in hex to FILE, followed by a newline.  */
997
void
998
displaced_step_dump_bytes (struct ui_file *file,
999
                           const gdb_byte *buf,
1000
                           size_t len)
1001
{
1002
  int i;
1003
 
1004
  for (i = 0; i < len; i++)
1005
    fprintf_unfiltered (file, "%02x ", buf[i]);
1006
  fputs_unfiltered ("\n", file);
1007
}
1008
 
1009
/* Prepare to single-step, using displaced stepping.
1010
 
1011
   Note that we cannot use displaced stepping when we have a signal to
1012
   deliver.  If we have a signal to deliver and an instruction to step
1013
   over, then after the step, there will be no indication from the
1014
   target whether the thread entered a signal handler or ignored the
1015
   signal and stepped over the instruction successfully --- both cases
1016
   result in a simple SIGTRAP.  In the first case we mustn't do a
1017
   fixup, and in the second case we must --- but we can't tell which.
1018
   Comments in the code for 'random signals' in handle_inferior_event
1019
   explain how we handle this case instead.
1020
 
1021
   Returns 1 if preparing was successful -- this thread is going to be
1022
   stepped now; or 0 if displaced stepping this thread got queued.  */
1023
static int
1024
displaced_step_prepare (ptid_t ptid)
1025
{
1026
  struct cleanup *old_cleanups, *ignore_cleanups;
1027
  struct regcache *regcache = get_thread_regcache (ptid);
1028
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
1029
  CORE_ADDR original, copy;
1030
  ULONGEST len;
1031
  struct displaced_step_closure *closure;
1032
 
1033
  /* We should never reach this function if the architecture does not
1034
     support displaced stepping.  */
1035
  gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1036
 
1037
  /* For the first cut, we're displaced stepping one thread at a
1038
     time.  */
1039
 
1040
  if (!ptid_equal (displaced_step_ptid, null_ptid))
1041
    {
1042
      /* Already waiting for a displaced step to finish.  Defer this
1043
         request and place in queue.  */
1044
      struct displaced_step_request *req, *new_req;
1045
 
1046
      if (debug_displaced)
1047
        fprintf_unfiltered (gdb_stdlog,
1048
                            "displaced: defering step of %s\n",
1049
                            target_pid_to_str (ptid));
1050
 
1051
      new_req = xmalloc (sizeof (*new_req));
1052
      new_req->ptid = ptid;
1053
      new_req->next = NULL;
1054
 
1055
      if (displaced_step_request_queue)
1056
        {
1057
          for (req = displaced_step_request_queue;
1058
               req && req->next;
1059
               req = req->next)
1060
            ;
1061
          req->next = new_req;
1062
        }
1063
      else
1064
        displaced_step_request_queue = new_req;
1065
 
1066
      return 0;
1067
    }
1068
  else
1069
    {
1070
      if (debug_displaced)
1071
        fprintf_unfiltered (gdb_stdlog,
1072
                            "displaced: stepping %s now\n",
1073
                            target_pid_to_str (ptid));
1074
    }
1075
 
1076
  displaced_step_clear ();
1077
 
1078
  old_cleanups = save_inferior_ptid ();
1079
  inferior_ptid = ptid;
1080
 
1081
  original = regcache_read_pc (regcache);
1082
 
1083
  copy = gdbarch_displaced_step_location (gdbarch);
1084
  len = gdbarch_max_insn_length (gdbarch);
1085
 
1086
  /* Save the original contents of the copy area.  */
1087
  displaced_step_saved_copy = xmalloc (len);
1088
  ignore_cleanups = make_cleanup (free_current_contents,
1089
                                  &displaced_step_saved_copy);
1090
  read_memory (copy, displaced_step_saved_copy, len);
1091
  if (debug_displaced)
1092
    {
1093
      fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1094
                          paddress (gdbarch, copy));
1095
      displaced_step_dump_bytes (gdb_stdlog, displaced_step_saved_copy, len);
1096
    };
1097
 
1098
  closure = gdbarch_displaced_step_copy_insn (gdbarch,
1099
                                              original, copy, regcache);
1100
 
1101
  /* We don't support the fully-simulated case at present.  */
1102
  gdb_assert (closure);
1103
 
1104
  /* Save the information we need to fix things up if the step
1105
     succeeds.  */
1106
  displaced_step_ptid = ptid;
1107
  displaced_step_gdbarch = gdbarch;
1108
  displaced_step_closure = closure;
1109
  displaced_step_original = original;
1110
  displaced_step_copy = copy;
1111
 
1112
  make_cleanup (displaced_step_clear_cleanup, 0);
1113
 
1114
  /* Resume execution at the copy.  */
1115
  regcache_write_pc (regcache, copy);
1116
 
1117
  discard_cleanups (ignore_cleanups);
1118
 
1119
  do_cleanups (old_cleanups);
1120
 
1121
  if (debug_displaced)
1122
    fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1123
                        paddress (gdbarch, copy));
1124
 
1125
  return 1;
1126
}
1127
 
1128
static void
1129
write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, const gdb_byte *myaddr, int len)
1130
{
1131
  struct cleanup *ptid_cleanup = save_inferior_ptid ();
1132
  inferior_ptid = ptid;
1133
  write_memory (memaddr, myaddr, len);
1134
  do_cleanups (ptid_cleanup);
1135
}
1136
 
1137
static void
1138
displaced_step_fixup (ptid_t event_ptid, enum target_signal signal)
1139
{
1140
  struct cleanup *old_cleanups;
1141
 
1142
  /* Was this event for the pid we displaced?  */
1143
  if (ptid_equal (displaced_step_ptid, null_ptid)
1144
      || ! ptid_equal (displaced_step_ptid, event_ptid))
1145
    return;
1146
 
1147
  old_cleanups = make_cleanup (displaced_step_clear_cleanup, 0);
1148
 
1149
  /* Restore the contents of the copy area.  */
1150
  {
1151
    ULONGEST len = gdbarch_max_insn_length (displaced_step_gdbarch);
1152
    write_memory_ptid (displaced_step_ptid, displaced_step_copy,
1153
                       displaced_step_saved_copy, len);
1154
    if (debug_displaced)
1155
      fprintf_unfiltered (gdb_stdlog, "displaced: restored %s\n",
1156
                          paddress (displaced_step_gdbarch,
1157
                                    displaced_step_copy));
1158
  }
1159
 
1160
  /* Did the instruction complete successfully?  */
1161
  if (signal == TARGET_SIGNAL_TRAP)
1162
    {
1163
      /* Fix up the resulting state.  */
1164
      gdbarch_displaced_step_fixup (displaced_step_gdbarch,
1165
                                    displaced_step_closure,
1166
                                    displaced_step_original,
1167
                                    displaced_step_copy,
1168
                                    get_thread_regcache (displaced_step_ptid));
1169
    }
1170
  else
1171
    {
1172
      /* Since the instruction didn't complete, all we can do is
1173
         relocate the PC.  */
1174
      struct regcache *regcache = get_thread_regcache (event_ptid);
1175
      CORE_ADDR pc = regcache_read_pc (regcache);
1176
      pc = displaced_step_original + (pc - displaced_step_copy);
1177
      regcache_write_pc (regcache, pc);
1178
    }
1179
 
1180
  do_cleanups (old_cleanups);
1181
 
1182
  displaced_step_ptid = null_ptid;
1183
 
1184
  /* Are there any pending displaced stepping requests?  If so, run
1185
     one now.  */
1186
  while (displaced_step_request_queue)
1187
    {
1188
      struct displaced_step_request *head;
1189
      ptid_t ptid;
1190
      struct regcache *regcache;
1191
      struct gdbarch *gdbarch;
1192
      CORE_ADDR actual_pc;
1193
      struct address_space *aspace;
1194
 
1195
      head = displaced_step_request_queue;
1196
      ptid = head->ptid;
1197
      displaced_step_request_queue = head->next;
1198
      xfree (head);
1199
 
1200
      context_switch (ptid);
1201
 
1202
      regcache = get_thread_regcache (ptid);
1203
      actual_pc = regcache_read_pc (regcache);
1204
      aspace = get_regcache_aspace (regcache);
1205
 
1206
      if (breakpoint_here_p (aspace, actual_pc))
1207
        {
1208
          if (debug_displaced)
1209
            fprintf_unfiltered (gdb_stdlog,
1210
                                "displaced: stepping queued %s now\n",
1211
                                target_pid_to_str (ptid));
1212
 
1213
          displaced_step_prepare (ptid);
1214
 
1215
          gdbarch = get_regcache_arch (regcache);
1216
 
1217
          if (debug_displaced)
1218
            {
1219
              CORE_ADDR actual_pc = regcache_read_pc (regcache);
1220
              gdb_byte buf[4];
1221
 
1222
              fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1223
                                  paddress (gdbarch, actual_pc));
1224
              read_memory (actual_pc, buf, sizeof (buf));
1225
              displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1226
            }
1227
 
1228
          if (gdbarch_displaced_step_hw_singlestep
1229
                (gdbarch, displaced_step_closure))
1230
            target_resume (ptid, 1, TARGET_SIGNAL_0);
1231
          else
1232
            target_resume (ptid, 0, TARGET_SIGNAL_0);
1233
 
1234
          /* Done, we're stepping a thread.  */
1235
          break;
1236
        }
1237
      else
1238
        {
1239
          int step;
1240
          struct thread_info *tp = inferior_thread ();
1241
 
1242
          /* The breakpoint we were sitting under has since been
1243
             removed.  */
1244
          tp->trap_expected = 0;
1245
 
1246
          /* Go back to what we were trying to do.  */
1247
          step = currently_stepping (tp);
1248
 
1249
          if (debug_displaced)
1250
            fprintf_unfiltered (gdb_stdlog, "breakpoint is gone %s: step(%d)\n",
1251
                                target_pid_to_str (tp->ptid), step);
1252
 
1253
          target_resume (ptid, step, TARGET_SIGNAL_0);
1254
          tp->stop_signal = TARGET_SIGNAL_0;
1255
 
1256
          /* This request was discarded.  See if there's any other
1257
             thread waiting for its turn.  */
1258
        }
1259
    }
1260
}
1261
 
1262
/* Update global variables holding ptids to hold NEW_PTID if they were
1263
   holding OLD_PTID.  */
1264
static void
1265
infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1266
{
1267
  struct displaced_step_request *it;
1268
 
1269
  if (ptid_equal (inferior_ptid, old_ptid))
1270
    inferior_ptid = new_ptid;
1271
 
1272
  if (ptid_equal (singlestep_ptid, old_ptid))
1273
    singlestep_ptid = new_ptid;
1274
 
1275
  if (ptid_equal (displaced_step_ptid, old_ptid))
1276
    displaced_step_ptid = new_ptid;
1277
 
1278
  if (ptid_equal (deferred_step_ptid, old_ptid))
1279
    deferred_step_ptid = new_ptid;
1280
 
1281
  for (it = displaced_step_request_queue; it; it = it->next)
1282
    if (ptid_equal (it->ptid, old_ptid))
1283
      it->ptid = new_ptid;
1284
}
1285
 
1286
 
1287
/* Resuming.  */
1288
 
1289
/* Things to clean up if we QUIT out of resume ().  */
1290
static void
1291
resume_cleanups (void *ignore)
1292
{
1293
  normal_stop ();
1294
}
1295
 
1296
static const char schedlock_off[] = "off";
1297
static const char schedlock_on[] = "on";
1298
static const char schedlock_step[] = "step";
1299
static const char *scheduler_enums[] = {
1300
  schedlock_off,
1301
  schedlock_on,
1302
  schedlock_step,
1303
  NULL
1304
};
1305
static const char *scheduler_mode = schedlock_off;
1306
static void
1307
show_scheduler_mode (struct ui_file *file, int from_tty,
1308
                     struct cmd_list_element *c, const char *value)
1309
{
1310
  fprintf_filtered (file, _("\
1311
Mode for locking scheduler during execution is \"%s\".\n"),
1312
                    value);
1313
}
1314
 
1315
static void
1316
set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1317
{
1318
  if (!target_can_lock_scheduler)
1319
    {
1320
      scheduler_mode = schedlock_off;
1321
      error (_("Target '%s' cannot support this command."), target_shortname);
1322
    }
1323
}
1324
 
1325
/* True if execution commands resume all threads of all processes by
1326
   default; otherwise, resume only threads of the current inferior
1327
   process.  */
1328
int sched_multi = 0;
1329
 
1330
/* Try to setup for software single stepping over the specified location.
1331
   Return 1 if target_resume() should use hardware single step.
1332
 
1333
   GDBARCH the current gdbarch.
1334
   PC the location to step over.  */
1335
 
1336
static int
1337
maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1338
{
1339
  int hw_step = 1;
1340
 
1341
  if (gdbarch_software_single_step_p (gdbarch)
1342
      && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1343
    {
1344
      hw_step = 0;
1345
      /* Do not pull these breakpoints until after a `wait' in
1346
         `wait_for_inferior' */
1347
      singlestep_breakpoints_inserted_p = 1;
1348
      singlestep_ptid = inferior_ptid;
1349
      singlestep_pc = pc;
1350
    }
1351
  return hw_step;
1352
}
1353
 
1354
/* Resume the inferior, but allow a QUIT.  This is useful if the user
1355
   wants to interrupt some lengthy single-stepping operation
1356
   (for child processes, the SIGINT goes to the inferior, and so
1357
   we get a SIGINT random_signal, but for remote debugging and perhaps
1358
   other targets, that's not true).
1359
 
1360
   STEP nonzero if we should step (zero to continue instead).
1361
   SIG is the signal to give the inferior (zero for none).  */
1362
void
1363
resume (int step, enum target_signal sig)
1364
{
1365
  int should_resume = 1;
1366
  struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1367
  struct regcache *regcache = get_current_regcache ();
1368
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
1369
  struct thread_info *tp = inferior_thread ();
1370
  CORE_ADDR pc = regcache_read_pc (regcache);
1371
  struct address_space *aspace = get_regcache_aspace (regcache);
1372
 
1373
  QUIT;
1374
 
1375
  if (debug_infrun)
1376
    fprintf_unfiltered (gdb_stdlog,
1377
                        "infrun: resume (step=%d, signal=%d), "
1378
                        "trap_expected=%d\n",
1379
                        step, sig, tp->trap_expected);
1380
 
1381
  /* Some targets (e.g. Solaris x86) have a kernel bug when stepping
1382
     over an instruction that causes a page fault without triggering
1383
     a hardware watchpoint. The kernel properly notices that it shouldn't
1384
     stop, because the hardware watchpoint is not triggered, but it forgets
1385
     the step request and continues the program normally.
1386
     Work around the problem by removing hardware watchpoints if a step is
1387
     requested, GDB will check for a hardware watchpoint trigger after the
1388
     step anyway.  */
1389
  if (CANNOT_STEP_HW_WATCHPOINTS && step)
1390
    remove_hw_watchpoints ();
1391
 
1392
 
1393
  /* Normally, by the time we reach `resume', the breakpoints are either
1394
     removed or inserted, as appropriate.  The exception is if we're sitting
1395
     at a permanent breakpoint; we need to step over it, but permanent
1396
     breakpoints can't be removed.  So we have to test for it here.  */
1397
  if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1398
    {
1399
      if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1400
        gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1401
      else
1402
        error (_("\
1403
The program is stopped at a permanent breakpoint, but GDB does not know\n\
1404
how to step past a permanent breakpoint on this architecture.  Try using\n\
1405
a command like `return' or `jump' to continue execution."));
1406
    }
1407
 
1408
  /* If enabled, step over breakpoints by executing a copy of the
1409
     instruction at a different address.
1410
 
1411
     We can't use displaced stepping when we have a signal to deliver;
1412
     the comments for displaced_step_prepare explain why.  The
1413
     comments in the handle_inferior event for dealing with 'random
1414
     signals' explain what we do instead.  */
1415
  if (use_displaced_stepping (gdbarch)
1416
      && (tp->trap_expected
1417
          || (step && gdbarch_software_single_step_p (gdbarch)))
1418
      && sig == TARGET_SIGNAL_0)
1419
    {
1420
      if (!displaced_step_prepare (inferior_ptid))
1421
        {
1422
          /* Got placed in displaced stepping queue.  Will be resumed
1423
             later when all the currently queued displaced stepping
1424
             requests finish.  The thread is not executing at this point,
1425
             and the call to set_executing will be made later.  But we
1426
             need to call set_running here, since from frontend point of view,
1427
             the thread is running.  */
1428
          set_running (inferior_ptid, 1);
1429
          discard_cleanups (old_cleanups);
1430
          return;
1431
        }
1432
 
1433
      step = gdbarch_displaced_step_hw_singlestep
1434
               (gdbarch, displaced_step_closure);
1435
    }
1436
 
1437
  /* Do we need to do it the hard way, w/temp breakpoints?  */
1438
  else if (step)
1439
    step = maybe_software_singlestep (gdbarch, pc);
1440
 
1441
  if (should_resume)
1442
    {
1443
      ptid_t resume_ptid;
1444
 
1445
      /* If STEP is set, it's a request to use hardware stepping
1446
         facilities.  But in that case, we should never
1447
         use singlestep breakpoint.  */
1448
      gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1449
 
1450
      /* Decide the set of threads to ask the target to resume.  Start
1451
         by assuming everything will be resumed, than narrow the set
1452
         by applying increasingly restricting conditions.  */
1453
 
1454
      /* By default, resume all threads of all processes.  */
1455
      resume_ptid = RESUME_ALL;
1456
 
1457
      /* Maybe resume only all threads of the current process.  */
1458
      if (!sched_multi && target_supports_multi_process ())
1459
        {
1460
          resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1461
        }
1462
 
1463
      /* Maybe resume a single thread after all.  */
1464
      if (singlestep_breakpoints_inserted_p
1465
          && stepping_past_singlestep_breakpoint)
1466
        {
1467
          /* The situation here is as follows.  In thread T1 we wanted to
1468
             single-step.  Lacking hardware single-stepping we've
1469
             set breakpoint at the PC of the next instruction -- call it
1470
             P.  After resuming, we've hit that breakpoint in thread T2.
1471
             Now we've removed original breakpoint, inserted breakpoint
1472
             at P+1, and try to step to advance T2 past breakpoint.
1473
             We need to step only T2, as if T1 is allowed to freely run,
1474
             it can run past P, and if other threads are allowed to run,
1475
             they can hit breakpoint at P+1, and nested hits of single-step
1476
             breakpoints is not something we'd want -- that's complicated
1477
             to support, and has no value.  */
1478
          resume_ptid = inferior_ptid;
1479
        }
1480
      else if ((step || singlestep_breakpoints_inserted_p)
1481
               && tp->trap_expected)
1482
        {
1483
          /* We're allowing a thread to run past a breakpoint it has
1484
             hit, by single-stepping the thread with the breakpoint
1485
             removed.  In which case, we need to single-step only this
1486
             thread, and keep others stopped, as they can miss this
1487
             breakpoint if allowed to run.
1488
 
1489
             The current code actually removes all breakpoints when
1490
             doing this, not just the one being stepped over, so if we
1491
             let other threads run, we can actually miss any
1492
             breakpoint, not just the one at PC.  */
1493
          resume_ptid = inferior_ptid;
1494
        }
1495
      else if (non_stop)
1496
        {
1497
          /* With non-stop mode on, threads are always handled
1498
             individually.  */
1499
          resume_ptid = inferior_ptid;
1500
        }
1501
      else if ((scheduler_mode == schedlock_on)
1502
               || (scheduler_mode == schedlock_step
1503
                   && (step || singlestep_breakpoints_inserted_p)))
1504
        {
1505
          /* User-settable 'scheduler' mode requires solo thread resume. */
1506
          resume_ptid = inferior_ptid;
1507
        }
1508
 
1509
      if (gdbarch_cannot_step_breakpoint (gdbarch))
1510
        {
1511
          /* Most targets can step a breakpoint instruction, thus
1512
             executing it normally.  But if this one cannot, just
1513
             continue and we will hit it anyway.  */
1514
          if (step && breakpoint_inserted_here_p (aspace, pc))
1515
            step = 0;
1516
        }
1517
 
1518
      if (debug_displaced
1519
          && use_displaced_stepping (gdbarch)
1520
          && tp->trap_expected)
1521
        {
1522
          struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1523
          struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1524
          CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1525
          gdb_byte buf[4];
1526
 
1527
          fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1528
                              paddress (resume_gdbarch, actual_pc));
1529
          read_memory (actual_pc, buf, sizeof (buf));
1530
          displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1531
        }
1532
 
1533
      /* Install inferior's terminal modes.  */
1534
      target_terminal_inferior ();
1535
 
1536
      /* Avoid confusing the next resume, if the next stop/resume
1537
         happens to apply to another thread.  */
1538
      tp->stop_signal = TARGET_SIGNAL_0;
1539
 
1540
      target_resume (resume_ptid, step, sig);
1541
    }
1542
 
1543
  discard_cleanups (old_cleanups);
1544
}
1545
 
1546
/* Proceeding.  */
1547
 
1548
/* Clear out all variables saying what to do when inferior is continued.
1549
   First do this, then set the ones you want, then call `proceed'.  */
1550
 
1551
static void
1552
clear_proceed_status_thread (struct thread_info *tp)
1553
{
1554
  if (debug_infrun)
1555
    fprintf_unfiltered (gdb_stdlog,
1556
                        "infrun: clear_proceed_status_thread (%s)\n",
1557
                        target_pid_to_str (tp->ptid));
1558
 
1559
  tp->trap_expected = 0;
1560
  tp->step_range_start = 0;
1561
  tp->step_range_end = 0;
1562
  tp->step_frame_id = null_frame_id;
1563
  tp->step_stack_frame_id = null_frame_id;
1564
  tp->step_over_calls = STEP_OVER_UNDEBUGGABLE;
1565
  tp->stop_requested = 0;
1566
 
1567
  tp->stop_step = 0;
1568
 
1569
  tp->proceed_to_finish = 0;
1570
 
1571
  /* Discard any remaining commands or status from previous stop.  */
1572
  bpstat_clear (&tp->stop_bpstat);
1573
}
1574
 
1575
static int
1576
clear_proceed_status_callback (struct thread_info *tp, void *data)
1577
{
1578
  if (is_exited (tp->ptid))
1579
    return 0;
1580
 
1581
  clear_proceed_status_thread (tp);
1582
  return 0;
1583
}
1584
 
1585
void
1586
clear_proceed_status (void)
1587
{
1588
  if (!non_stop)
1589
    {
1590
      /* In all-stop mode, delete the per-thread status of all
1591
         threads, even if inferior_ptid is null_ptid, there may be
1592
         threads on the list.  E.g., we may be launching a new
1593
         process, while selecting the executable.  */
1594
      iterate_over_threads (clear_proceed_status_callback, NULL);
1595
    }
1596
 
1597
  if (!ptid_equal (inferior_ptid, null_ptid))
1598
    {
1599
      struct inferior *inferior;
1600
 
1601
      if (non_stop)
1602
        {
1603
          /* If in non-stop mode, only delete the per-thread status of
1604
             the current thread.  */
1605
          clear_proceed_status_thread (inferior_thread ());
1606
        }
1607
 
1608
      inferior = current_inferior ();
1609
      inferior->stop_soon = NO_STOP_QUIETLY;
1610
    }
1611
 
1612
  stop_after_trap = 0;
1613
 
1614
  observer_notify_about_to_proceed ();
1615
 
1616
  if (stop_registers)
1617
    {
1618
      regcache_xfree (stop_registers);
1619
      stop_registers = NULL;
1620
    }
1621
}
1622
 
1623
/* Check the current thread against the thread that reported the most recent
1624
   event.  If a step-over is required return TRUE and set the current thread
1625
   to the old thread.  Otherwise return FALSE.
1626
 
1627
   This should be suitable for any targets that support threads. */
1628
 
1629
static int
1630
prepare_to_proceed (int step)
1631
{
1632
  ptid_t wait_ptid;
1633
  struct target_waitstatus wait_status;
1634
  int schedlock_enabled;
1635
 
1636
  /* With non-stop mode on, threads are always handled individually.  */
1637
  gdb_assert (! non_stop);
1638
 
1639
  /* Get the last target status returned by target_wait().  */
1640
  get_last_target_status (&wait_ptid, &wait_status);
1641
 
1642
  /* Make sure we were stopped at a breakpoint.  */
1643
  if (wait_status.kind != TARGET_WAITKIND_STOPPED
1644
      || (wait_status.value.sig != TARGET_SIGNAL_TRAP
1645
          && wait_status.value.sig != TARGET_SIGNAL_ILL
1646
          && wait_status.value.sig != TARGET_SIGNAL_SEGV
1647
          && wait_status.value.sig != TARGET_SIGNAL_EMT))
1648
    {
1649
      return 0;
1650
    }
1651
 
1652
  schedlock_enabled = (scheduler_mode == schedlock_on
1653
                       || (scheduler_mode == schedlock_step
1654
                           && step));
1655
 
1656
  /* Don't switch over to WAIT_PTID if scheduler locking is on.  */
1657
  if (schedlock_enabled)
1658
    return 0;
1659
 
1660
  /* Don't switch over if we're about to resume some other process
1661
     other than WAIT_PTID's, and schedule-multiple is off.  */
1662
  if (!sched_multi
1663
      && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
1664
    return 0;
1665
 
1666
  /* Switched over from WAIT_PID.  */
1667
  if (!ptid_equal (wait_ptid, minus_one_ptid)
1668
      && !ptid_equal (inferior_ptid, wait_ptid))
1669
    {
1670
      struct regcache *regcache = get_thread_regcache (wait_ptid);
1671
 
1672
      if (breakpoint_here_p (get_regcache_aspace (regcache),
1673
                             regcache_read_pc (regcache)))
1674
        {
1675
          /* If stepping, remember current thread to switch back to.  */
1676
          if (step)
1677
            deferred_step_ptid = inferior_ptid;
1678
 
1679
          /* Switch back to WAIT_PID thread.  */
1680
          switch_to_thread (wait_ptid);
1681
 
1682
          /* We return 1 to indicate that there is a breakpoint here,
1683
             so we need to step over it before continuing to avoid
1684
             hitting it straight away. */
1685
          return 1;
1686
        }
1687
    }
1688
 
1689
  return 0;
1690
}
1691
 
1692
/* Basic routine for continuing the program in various fashions.
1693
 
1694
   ADDR is the address to resume at, or -1 for resume where stopped.
1695
   SIGGNAL is the signal to give it, or 0 for none,
1696
   or -1 for act according to how it stopped.
1697
   STEP is nonzero if should trap after one instruction.
1698
   -1 means return after that and print nothing.
1699
   You should probably set various step_... variables
1700
   before calling here, if you are stepping.
1701
 
1702
   You should call clear_proceed_status before calling proceed.  */
1703
 
1704
void
1705
proceed (CORE_ADDR addr, enum target_signal siggnal, int step)
1706
{
1707
  struct regcache *regcache;
1708
  struct gdbarch *gdbarch;
1709
  struct thread_info *tp;
1710
  CORE_ADDR pc;
1711
  struct address_space *aspace;
1712
  int oneproc = 0;
1713
 
1714
  /* If we're stopped at a fork/vfork, follow the branch set by the
1715
     "set follow-fork-mode" command; otherwise, we'll just proceed
1716
     resuming the current thread.  */
1717
  if (!follow_fork ())
1718
    {
1719
      /* The target for some reason decided not to resume.  */
1720
      normal_stop ();
1721
      return;
1722
    }
1723
 
1724
  regcache = get_current_regcache ();
1725
  gdbarch = get_regcache_arch (regcache);
1726
  aspace = get_regcache_aspace (regcache);
1727
  pc = regcache_read_pc (regcache);
1728
 
1729
  if (step > 0)
1730
    step_start_function = find_pc_function (pc);
1731
  if (step < 0)
1732
    stop_after_trap = 1;
1733
 
1734
  if (addr == (CORE_ADDR) -1)
1735
    {
1736
      if (pc == stop_pc && breakpoint_here_p (aspace, pc)
1737
          && execution_direction != EXEC_REVERSE)
1738
        /* There is a breakpoint at the address we will resume at,
1739
           step one instruction before inserting breakpoints so that
1740
           we do not stop right away (and report a second hit at this
1741
           breakpoint).
1742
 
1743
           Note, we don't do this in reverse, because we won't
1744
           actually be executing the breakpoint insn anyway.
1745
           We'll be (un-)executing the previous instruction.  */
1746
 
1747
        oneproc = 1;
1748
      else if (gdbarch_single_step_through_delay_p (gdbarch)
1749
               && gdbarch_single_step_through_delay (gdbarch,
1750
                                                     get_current_frame ()))
1751
        /* We stepped onto an instruction that needs to be stepped
1752
           again before re-inserting the breakpoint, do so.  */
1753
        oneproc = 1;
1754
    }
1755
  else
1756
    {
1757
      regcache_write_pc (regcache, addr);
1758
    }
1759
 
1760
  if (debug_infrun)
1761
    fprintf_unfiltered (gdb_stdlog,
1762
                        "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
1763
                        paddress (gdbarch, addr), siggnal, step);
1764
 
1765
  /* We're handling a live event, so make sure we're doing live
1766
     debugging.  If we're looking at traceframes while the target is
1767
     running, we're going to need to get back to that mode after
1768
     handling the event.  */
1769
  if (non_stop)
1770
    {
1771
      make_cleanup_restore_current_traceframe ();
1772
      set_traceframe_number (-1);
1773
    }
1774
 
1775
  if (non_stop)
1776
    /* In non-stop, each thread is handled individually.  The context
1777
       must already be set to the right thread here.  */
1778
    ;
1779
  else
1780
    {
1781
      /* In a multi-threaded task we may select another thread and
1782
         then continue or step.
1783
 
1784
         But if the old thread was stopped at a breakpoint, it will
1785
         immediately cause another breakpoint stop without any
1786
         execution (i.e. it will report a breakpoint hit incorrectly).
1787
         So we must step over it first.
1788
 
1789
         prepare_to_proceed checks the current thread against the
1790
         thread that reported the most recent event.  If a step-over
1791
         is required it returns TRUE and sets the current thread to
1792
         the old thread. */
1793
      if (prepare_to_proceed (step))
1794
        oneproc = 1;
1795
    }
1796
 
1797
  /* prepare_to_proceed may change the current thread.  */
1798
  tp = inferior_thread ();
1799
 
1800
  if (oneproc)
1801
    {
1802
      tp->trap_expected = 1;
1803
      /* If displaced stepping is enabled, we can step over the
1804
         breakpoint without hitting it, so leave all breakpoints
1805
         inserted.  Otherwise we need to disable all breakpoints, step
1806
         one instruction, and then re-add them when that step is
1807
         finished.  */
1808
      if (!use_displaced_stepping (gdbarch))
1809
        remove_breakpoints ();
1810
    }
1811
 
1812
  /* We can insert breakpoints if we're not trying to step over one,
1813
     or if we are stepping over one but we're using displaced stepping
1814
     to do so.  */
1815
  if (! tp->trap_expected || use_displaced_stepping (gdbarch))
1816
    insert_breakpoints ();
1817
 
1818
  if (!non_stop)
1819
    {
1820
      /* Pass the last stop signal to the thread we're resuming,
1821
         irrespective of whether the current thread is the thread that
1822
         got the last event or not.  This was historically GDB's
1823
         behaviour before keeping a stop_signal per thread.  */
1824
 
1825
      struct thread_info *last_thread;
1826
      ptid_t last_ptid;
1827
      struct target_waitstatus last_status;
1828
 
1829
      get_last_target_status (&last_ptid, &last_status);
1830
      if (!ptid_equal (inferior_ptid, last_ptid)
1831
          && !ptid_equal (last_ptid, null_ptid)
1832
          && !ptid_equal (last_ptid, minus_one_ptid))
1833
        {
1834
          last_thread = find_thread_ptid (last_ptid);
1835
          if (last_thread)
1836
            {
1837
              tp->stop_signal = last_thread->stop_signal;
1838
              last_thread->stop_signal = TARGET_SIGNAL_0;
1839
            }
1840
        }
1841
    }
1842
 
1843
  if (siggnal != TARGET_SIGNAL_DEFAULT)
1844
    tp->stop_signal = siggnal;
1845
  /* If this signal should not be seen by program,
1846
     give it zero.  Used for debugging signals.  */
1847
  else if (!signal_program[tp->stop_signal])
1848
    tp->stop_signal = TARGET_SIGNAL_0;
1849
 
1850
  annotate_starting ();
1851
 
1852
  /* Make sure that output from GDB appears before output from the
1853
     inferior.  */
1854
  gdb_flush (gdb_stdout);
1855
 
1856
  /* Refresh prev_pc value just prior to resuming.  This used to be
1857
     done in stop_stepping, however, setting prev_pc there did not handle
1858
     scenarios such as inferior function calls or returning from
1859
     a function via the return command.  In those cases, the prev_pc
1860
     value was not set properly for subsequent commands.  The prev_pc value
1861
     is used to initialize the starting line number in the ecs.  With an
1862
     invalid value, the gdb next command ends up stopping at the position
1863
     represented by the next line table entry past our start position.
1864
     On platforms that generate one line table entry per line, this
1865
     is not a problem.  However, on the ia64, the compiler generates
1866
     extraneous line table entries that do not increase the line number.
1867
     When we issue the gdb next command on the ia64 after an inferior call
1868
     or a return command, we often end up a few instructions forward, still
1869
     within the original line we started.
1870
 
1871
     An attempt was made to refresh the prev_pc at the same time the
1872
     execution_control_state is initialized (for instance, just before
1873
     waiting for an inferior event).  But this approach did not work
1874
     because of platforms that use ptrace, where the pc register cannot
1875
     be read unless the inferior is stopped.  At that point, we are not
1876
     guaranteed the inferior is stopped and so the regcache_read_pc() call
1877
     can fail.  Setting the prev_pc value here ensures the value is updated
1878
     correctly when the inferior is stopped.  */
1879
  tp->prev_pc = regcache_read_pc (get_current_regcache ());
1880
 
1881
  /* Fill in with reasonable starting values.  */
1882
  init_thread_stepping_state (tp);
1883
 
1884
  /* Reset to normal state.  */
1885
  init_infwait_state ();
1886
 
1887
  /* Resume inferior.  */
1888
  resume (oneproc || step || bpstat_should_step (), tp->stop_signal);
1889
 
1890
  /* Wait for it to stop (if not standalone)
1891
     and in any case decode why it stopped, and act accordingly.  */
1892
  /* Do this only if we are not using the event loop, or if the target
1893
     does not support asynchronous execution. */
1894
  if (!target_can_async_p ())
1895
    {
1896
      wait_for_inferior (0);
1897
      normal_stop ();
1898
    }
1899
}
1900
 
1901
 
1902
/* Start remote-debugging of a machine over a serial link.  */
1903
 
1904
void
1905
start_remote (int from_tty)
1906
{
1907
  struct inferior *inferior;
1908
  init_wait_for_inferior ();
1909
 
1910
  inferior = current_inferior ();
1911
  inferior->stop_soon = STOP_QUIETLY_REMOTE;
1912
 
1913
  /* Always go on waiting for the target, regardless of the mode. */
1914
  /* FIXME: cagney/1999-09-23: At present it isn't possible to
1915
     indicate to wait_for_inferior that a target should timeout if
1916
     nothing is returned (instead of just blocking).  Because of this,
1917
     targets expecting an immediate response need to, internally, set
1918
     things up so that the target_wait() is forced to eventually
1919
     timeout. */
1920
  /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
1921
     differentiate to its caller what the state of the target is after
1922
     the initial open has been performed.  Here we're assuming that
1923
     the target has stopped.  It should be possible to eventually have
1924
     target_open() return to the caller an indication that the target
1925
     is currently running and GDB state should be set to the same as
1926
     for an async run. */
1927
  wait_for_inferior (0);
1928
 
1929
  /* Now that the inferior has stopped, do any bookkeeping like
1930
     loading shared libraries.  We want to do this before normal_stop,
1931
     so that the displayed frame is up to date.  */
1932
  post_create_inferior (&current_target, from_tty);
1933
 
1934
  normal_stop ();
1935
}
1936
 
1937
/* Initialize static vars when a new inferior begins.  */
1938
 
1939
void
1940
init_wait_for_inferior (void)
1941
{
1942
  /* These are meaningless until the first time through wait_for_inferior.  */
1943
 
1944
  breakpoint_init_inferior (inf_starting);
1945
 
1946
  clear_proceed_status ();
1947
 
1948
  stepping_past_singlestep_breakpoint = 0;
1949
  deferred_step_ptid = null_ptid;
1950
 
1951
  target_last_wait_ptid = minus_one_ptid;
1952
 
1953
  previous_inferior_ptid = null_ptid;
1954
  init_infwait_state ();
1955
 
1956
  displaced_step_clear ();
1957
 
1958
  /* Discard any skipped inlined frames.  */
1959
  clear_inline_frame_state (minus_one_ptid);
1960
}
1961
 
1962
 
1963
/* This enum encodes possible reasons for doing a target_wait, so that
1964
   wfi can call target_wait in one place.  (Ultimately the call will be
1965
   moved out of the infinite loop entirely.) */
1966
 
1967
enum infwait_states
1968
{
1969
  infwait_normal_state,
1970
  infwait_thread_hop_state,
1971
  infwait_step_watch_state,
1972
  infwait_nonstep_watch_state
1973
};
1974
 
1975
/* Why did the inferior stop? Used to print the appropriate messages
1976
   to the interface from within handle_inferior_event(). */
1977
enum inferior_stop_reason
1978
{
1979
  /* Step, next, nexti, stepi finished. */
1980
  END_STEPPING_RANGE,
1981
  /* Inferior terminated by signal. */
1982
  SIGNAL_EXITED,
1983
  /* Inferior exited. */
1984
  EXITED,
1985
  /* Inferior received signal, and user asked to be notified. */
1986
  SIGNAL_RECEIVED,
1987
  /* Reverse execution -- target ran out of history info.  */
1988
  NO_HISTORY
1989
};
1990
 
1991
/* The PTID we'll do a target_wait on.*/
1992
ptid_t waiton_ptid;
1993
 
1994
/* Current inferior wait state.  */
1995
enum infwait_states infwait_state;
1996
 
1997
/* Data to be passed around while handling an event.  This data is
1998
   discarded between events.  */
1999
struct execution_control_state
2000
{
2001
  ptid_t ptid;
2002
  /* The thread that got the event, if this was a thread event; NULL
2003
     otherwise.  */
2004
  struct thread_info *event_thread;
2005
 
2006
  struct target_waitstatus ws;
2007
  int random_signal;
2008
  CORE_ADDR stop_func_start;
2009
  CORE_ADDR stop_func_end;
2010
  char *stop_func_name;
2011
  int new_thread_event;
2012
  int wait_some_more;
2013
};
2014
 
2015
static void handle_inferior_event (struct execution_control_state *ecs);
2016
 
2017
static void handle_step_into_function (struct gdbarch *gdbarch,
2018
                                       struct execution_control_state *ecs);
2019
static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2020
                                                struct execution_control_state *ecs);
2021
static void insert_step_resume_breakpoint_at_frame (struct frame_info *step_frame);
2022
static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
2023
static void insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
2024
                                                  struct symtab_and_line sr_sal,
2025
                                                  struct frame_id sr_id);
2026
static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
2027
 
2028
static void stop_stepping (struct execution_control_state *ecs);
2029
static void prepare_to_wait (struct execution_control_state *ecs);
2030
static void keep_going (struct execution_control_state *ecs);
2031
static void print_stop_reason (enum inferior_stop_reason stop_reason,
2032
                               int stop_info);
2033
 
2034
/* Callback for iterate over threads.  If the thread is stopped, but
2035
   the user/frontend doesn't know about that yet, go through
2036
   normal_stop, as if the thread had just stopped now.  ARG points at
2037
   a ptid.  If PTID is MINUS_ONE_PTID, applies to all threads.  If
2038
   ptid_is_pid(PTID) is true, applies to all threads of the process
2039
   pointed at by PTID.  Otherwise, apply only to the thread pointed by
2040
   PTID.  */
2041
 
2042
static int
2043
infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2044
{
2045
  ptid_t ptid = * (ptid_t *) arg;
2046
 
2047
  if ((ptid_equal (info->ptid, ptid)
2048
       || ptid_equal (minus_one_ptid, ptid)
2049
       || (ptid_is_pid (ptid)
2050
           && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2051
      && is_running (info->ptid)
2052
      && !is_executing (info->ptid))
2053
    {
2054
      struct cleanup *old_chain;
2055
      struct execution_control_state ecss;
2056
      struct execution_control_state *ecs = &ecss;
2057
 
2058
      memset (ecs, 0, sizeof (*ecs));
2059
 
2060
      old_chain = make_cleanup_restore_current_thread ();
2061
 
2062
      switch_to_thread (info->ptid);
2063
 
2064
      /* Go through handle_inferior_event/normal_stop, so we always
2065
         have consistent output as if the stop event had been
2066
         reported.  */
2067
      ecs->ptid = info->ptid;
2068
      ecs->event_thread = find_thread_ptid (info->ptid);
2069
      ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2070
      ecs->ws.value.sig = TARGET_SIGNAL_0;
2071
 
2072
      handle_inferior_event (ecs);
2073
 
2074
      if (!ecs->wait_some_more)
2075
        {
2076
          struct thread_info *tp;
2077
 
2078
          normal_stop ();
2079
 
2080
          /* Finish off the continuations.  The continations
2081
             themselves are responsible for realising the thread
2082
             didn't finish what it was supposed to do.  */
2083
          tp = inferior_thread ();
2084
          do_all_intermediate_continuations_thread (tp);
2085
          do_all_continuations_thread (tp);
2086
        }
2087
 
2088
      do_cleanups (old_chain);
2089
    }
2090
 
2091
  return 0;
2092
}
2093
 
2094
/* This function is attached as a "thread_stop_requested" observer.
2095
   Cleanup local state that assumed the PTID was to be resumed, and
2096
   report the stop to the frontend.  */
2097
 
2098
static void
2099
infrun_thread_stop_requested (ptid_t ptid)
2100
{
2101
  struct displaced_step_request *it, *next, *prev = NULL;
2102
 
2103
  /* PTID was requested to stop.  Remove it from the displaced
2104
     stepping queue, so we don't try to resume it automatically.  */
2105
  for (it = displaced_step_request_queue; it; it = next)
2106
    {
2107
      next = it->next;
2108
 
2109
      if (ptid_equal (it->ptid, ptid)
2110
          || ptid_equal (minus_one_ptid, ptid)
2111
          || (ptid_is_pid (ptid)
2112
              && ptid_get_pid (ptid) == ptid_get_pid (it->ptid)))
2113
        {
2114
          if (displaced_step_request_queue == it)
2115
            displaced_step_request_queue = it->next;
2116
          else
2117
            prev->next = it->next;
2118
 
2119
          xfree (it);
2120
        }
2121
      else
2122
        prev = it;
2123
    }
2124
 
2125
  iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2126
}
2127
 
2128
static void
2129
infrun_thread_thread_exit (struct thread_info *tp, int silent)
2130
{
2131
  if (ptid_equal (target_last_wait_ptid, tp->ptid))
2132
    nullify_last_target_wait_ptid ();
2133
}
2134
 
2135
/* Callback for iterate_over_threads.  */
2136
 
2137
static int
2138
delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2139
{
2140
  if (is_exited (info->ptid))
2141
    return 0;
2142
 
2143
  delete_step_resume_breakpoint (info);
2144
  return 0;
2145
}
2146
 
2147
/* In all-stop, delete the step resume breakpoint of any thread that
2148
   had one.  In non-stop, delete the step resume breakpoint of the
2149
   thread that just stopped.  */
2150
 
2151
static void
2152
delete_step_thread_step_resume_breakpoint (void)
2153
{
2154
  if (!target_has_execution
2155
      || ptid_equal (inferior_ptid, null_ptid))
2156
    /* If the inferior has exited, we have already deleted the step
2157
       resume breakpoints out of GDB's lists.  */
2158
    return;
2159
 
2160
  if (non_stop)
2161
    {
2162
      /* If in non-stop mode, only delete the step-resume or
2163
         longjmp-resume breakpoint of the thread that just stopped
2164
         stepping.  */
2165
      struct thread_info *tp = inferior_thread ();
2166
      delete_step_resume_breakpoint (tp);
2167
    }
2168
  else
2169
    /* In all-stop mode, delete all step-resume and longjmp-resume
2170
       breakpoints of any thread that had them.  */
2171
    iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2172
}
2173
 
2174
/* A cleanup wrapper. */
2175
 
2176
static void
2177
delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2178
{
2179
  delete_step_thread_step_resume_breakpoint ();
2180
}
2181
 
2182
/* Pretty print the results of target_wait, for debugging purposes.  */
2183
 
2184
static void
2185
print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2186
                           const struct target_waitstatus *ws)
2187
{
2188
  char *status_string = target_waitstatus_to_string (ws);
2189
  struct ui_file *tmp_stream = mem_fileopen ();
2190
  char *text;
2191
 
2192
  /* The text is split over several lines because it was getting too long.
2193
     Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2194
     output as a unit; we want only one timestamp printed if debug_timestamp
2195
     is set.  */
2196
 
2197
  fprintf_unfiltered (tmp_stream,
2198
                      "infrun: target_wait (%d", PIDGET (waiton_ptid));
2199
  if (PIDGET (waiton_ptid) != -1)
2200
    fprintf_unfiltered (tmp_stream,
2201
                        " [%s]", target_pid_to_str (waiton_ptid));
2202
  fprintf_unfiltered (tmp_stream, ", status) =\n");
2203
  fprintf_unfiltered (tmp_stream,
2204
                      "infrun:   %d [%s],\n",
2205
                      PIDGET (result_ptid), target_pid_to_str (result_ptid));
2206
  fprintf_unfiltered (tmp_stream,
2207
                      "infrun:   %s\n",
2208
                      status_string);
2209
 
2210
  text = ui_file_xstrdup (tmp_stream, NULL);
2211
 
2212
  /* This uses %s in part to handle %'s in the text, but also to avoid
2213
     a gcc error: the format attribute requires a string literal.  */
2214
  fprintf_unfiltered (gdb_stdlog, "%s", text);
2215
 
2216
  xfree (status_string);
2217
  xfree (text);
2218
  ui_file_delete (tmp_stream);
2219
}
2220
 
2221
/* Wait for control to return from inferior to debugger.
2222
 
2223
   If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals
2224
   as if they were SIGTRAP signals.  This can be useful during
2225
   the startup sequence on some targets such as HP/UX, where
2226
   we receive an EXEC event instead of the expected SIGTRAP.
2227
 
2228
   If inferior gets a signal, we may decide to start it up again
2229
   instead of returning.  That is why there is a loop in this function.
2230
   When this function actually returns it means the inferior
2231
   should be left stopped and GDB should read more commands.  */
2232
 
2233
void
2234
wait_for_inferior (int treat_exec_as_sigtrap)
2235
{
2236
  struct cleanup *old_cleanups;
2237
  struct execution_control_state ecss;
2238
  struct execution_control_state *ecs;
2239
 
2240
  if (debug_infrun)
2241
    fprintf_unfiltered
2242
      (gdb_stdlog, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n",
2243
       treat_exec_as_sigtrap);
2244
 
2245
  old_cleanups =
2246
    make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2247
 
2248
  ecs = &ecss;
2249
  memset (ecs, 0, sizeof (*ecs));
2250
 
2251
  /* We'll update this if & when we switch to a new thread.  */
2252
  previous_inferior_ptid = inferior_ptid;
2253
 
2254
  while (1)
2255
    {
2256
      struct cleanup *old_chain;
2257
 
2258
      /* We have to invalidate the registers BEFORE calling target_wait
2259
         because they can be loaded from the target while in target_wait.
2260
         This makes remote debugging a bit more efficient for those
2261
         targets that provide critical registers as part of their normal
2262
         status mechanism. */
2263
 
2264
      overlay_cache_invalid = 1;
2265
      registers_changed ();
2266
 
2267
      if (deprecated_target_wait_hook)
2268
        ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2269
      else
2270
        ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2271
 
2272
      if (debug_infrun)
2273
        print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2274
 
2275
      if (treat_exec_as_sigtrap && ecs->ws.kind == TARGET_WAITKIND_EXECD)
2276
        {
2277
          xfree (ecs->ws.value.execd_pathname);
2278
          ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2279
          ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
2280
        }
2281
 
2282
      /* If an error happens while handling the event, propagate GDB's
2283
         knowledge of the executing state to the frontend/user running
2284
         state.  */
2285
      old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2286
 
2287
      if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY
2288
          || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN)
2289
        ecs->ws.value.syscall_number = UNKNOWN_SYSCALL;
2290
 
2291
      /* Now figure out what to do with the result of the result.  */
2292
      handle_inferior_event (ecs);
2293
 
2294
      /* No error, don't finish the state yet.  */
2295
      discard_cleanups (old_chain);
2296
 
2297
      if (!ecs->wait_some_more)
2298
        break;
2299
    }
2300
 
2301
  do_cleanups (old_cleanups);
2302
}
2303
 
2304
/* Asynchronous version of wait_for_inferior. It is called by the
2305
   event loop whenever a change of state is detected on the file
2306
   descriptor corresponding to the target. It can be called more than
2307
   once to complete a single execution command. In such cases we need
2308
   to keep the state in a global variable ECSS. If it is the last time
2309
   that this function is called for a single execution command, then
2310
   report to the user that the inferior has stopped, and do the
2311
   necessary cleanups. */
2312
 
2313
void
2314
fetch_inferior_event (void *client_data)
2315
{
2316
  struct execution_control_state ecss;
2317
  struct execution_control_state *ecs = &ecss;
2318
  struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2319
  struct cleanup *ts_old_chain;
2320
  int was_sync = sync_execution;
2321
 
2322
  memset (ecs, 0, sizeof (*ecs));
2323
 
2324
  /* We'll update this if & when we switch to a new thread.  */
2325
  previous_inferior_ptid = inferior_ptid;
2326
 
2327
  if (non_stop)
2328
    /* In non-stop mode, the user/frontend should not notice a thread
2329
       switch due to internal events.  Make sure we reverse to the
2330
       user selected thread and frame after handling the event and
2331
       running any breakpoint commands.  */
2332
    make_cleanup_restore_current_thread ();
2333
 
2334
  /* We have to invalidate the registers BEFORE calling target_wait
2335
     because they can be loaded from the target while in target_wait.
2336
     This makes remote debugging a bit more efficient for those
2337
     targets that provide critical registers as part of their normal
2338
     status mechanism. */
2339
 
2340
  overlay_cache_invalid = 1;
2341
  registers_changed ();
2342
 
2343
  if (deprecated_target_wait_hook)
2344
    ecs->ptid =
2345
      deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2346
  else
2347
    ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2348
 
2349
  if (debug_infrun)
2350
    print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2351
 
2352
  if (non_stop
2353
      && ecs->ws.kind != TARGET_WAITKIND_IGNORE
2354
      && ecs->ws.kind != TARGET_WAITKIND_EXITED
2355
      && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2356
    /* In non-stop mode, each thread is handled individually.  Switch
2357
       early, so the global state is set correctly for this
2358
       thread.  */
2359
    context_switch (ecs->ptid);
2360
 
2361
  /* If an error happens while handling the event, propagate GDB's
2362
     knowledge of the executing state to the frontend/user running
2363
     state.  */
2364
  if (!non_stop)
2365
    ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2366
  else
2367
    ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2368
 
2369
  /* Now figure out what to do with the result of the result.  */
2370
  handle_inferior_event (ecs);
2371
 
2372
  if (!ecs->wait_some_more)
2373
    {
2374
      struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2375
 
2376
      delete_step_thread_step_resume_breakpoint ();
2377
 
2378
      /* We may not find an inferior if this was a process exit.  */
2379
      if (inf == NULL || inf->stop_soon == NO_STOP_QUIETLY)
2380
        normal_stop ();
2381
 
2382
      if (target_has_execution
2383
          && ecs->ws.kind != TARGET_WAITKIND_EXITED
2384
          && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2385
          && ecs->event_thread->step_multi
2386
          && ecs->event_thread->stop_step)
2387
        inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2388
      else
2389
        inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2390
    }
2391
 
2392
  /* No error, don't finish the thread states yet.  */
2393
  discard_cleanups (ts_old_chain);
2394
 
2395
  /* Revert thread and frame.  */
2396
  do_cleanups (old_chain);
2397
 
2398
  /* If the inferior was in sync execution mode, and now isn't,
2399
     restore the prompt.  */
2400
  if (was_sync && !sync_execution)
2401
    display_gdb_prompt (0);
2402
}
2403
 
2404
/* Record the frame and location we're currently stepping through.  */
2405
void
2406
set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2407
{
2408
  struct thread_info *tp = inferior_thread ();
2409
 
2410
  tp->step_frame_id = get_frame_id (frame);
2411
  tp->step_stack_frame_id = get_stack_frame_id (frame);
2412
 
2413
  tp->current_symtab = sal.symtab;
2414
  tp->current_line = sal.line;
2415
}
2416
 
2417
/* Clear context switchable stepping state.  */
2418
 
2419
void
2420
init_thread_stepping_state (struct thread_info *tss)
2421
{
2422
  tss->stepping_over_breakpoint = 0;
2423
  tss->step_after_step_resume_breakpoint = 0;
2424
  tss->stepping_through_solib_after_catch = 0;
2425
  tss->stepping_through_solib_catchpoints = NULL;
2426
}
2427
 
2428
/* Return the cached copy of the last pid/waitstatus returned by
2429
   target_wait()/deprecated_target_wait_hook().  The data is actually
2430
   cached by handle_inferior_event(), which gets called immediately
2431
   after target_wait()/deprecated_target_wait_hook().  */
2432
 
2433
void
2434
get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2435
{
2436
  *ptidp = target_last_wait_ptid;
2437
  *status = target_last_waitstatus;
2438
}
2439
 
2440
void
2441
nullify_last_target_wait_ptid (void)
2442
{
2443
  target_last_wait_ptid = minus_one_ptid;
2444
}
2445
 
2446
/* Switch thread contexts.  */
2447
 
2448
static void
2449
context_switch (ptid_t ptid)
2450
{
2451
  if (debug_infrun)
2452
    {
2453
      fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2454
                          target_pid_to_str (inferior_ptid));
2455
      fprintf_unfiltered (gdb_stdlog, "to %s\n",
2456
                          target_pid_to_str (ptid));
2457
    }
2458
 
2459
  switch_to_thread (ptid);
2460
}
2461
 
2462
static void
2463
adjust_pc_after_break (struct execution_control_state *ecs)
2464
{
2465
  struct regcache *regcache;
2466
  struct gdbarch *gdbarch;
2467
  struct address_space *aspace;
2468
  CORE_ADDR breakpoint_pc;
2469
 
2470
  /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP.  If
2471
     we aren't, just return.
2472
 
2473
     We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2474
     affected by gdbarch_decr_pc_after_break.  Other waitkinds which are
2475
     implemented by software breakpoints should be handled through the normal
2476
     breakpoint layer.
2477
 
2478
     NOTE drow/2004-01-31: On some targets, breakpoints may generate
2479
     different signals (SIGILL or SIGEMT for instance), but it is less
2480
     clear where the PC is pointing afterwards.  It may not match
2481
     gdbarch_decr_pc_after_break.  I don't know any specific target that
2482
     generates these signals at breakpoints (the code has been in GDB since at
2483
     least 1992) so I can not guess how to handle them here.
2484
 
2485
     In earlier versions of GDB, a target with
2486
     gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2487
     watchpoint affected by gdbarch_decr_pc_after_break.  I haven't found any
2488
     target with both of these set in GDB history, and it seems unlikely to be
2489
     correct, so gdbarch_have_nonsteppable_watchpoint is not checked here.  */
2490
 
2491
  if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2492
    return;
2493
 
2494
  if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP)
2495
    return;
2496
 
2497
  /* In reverse execution, when a breakpoint is hit, the instruction
2498
     under it has already been de-executed.  The reported PC always
2499
     points at the breakpoint address, so adjusting it further would
2500
     be wrong.  E.g., consider this case on a decr_pc_after_break == 1
2501
     architecture:
2502
 
2503
       B1         0x08000000 :   INSN1
2504
       B2         0x08000001 :   INSN2
2505
                  0x08000002 :   INSN3
2506
            PC -> 0x08000003 :   INSN4
2507
 
2508
     Say you're stopped at 0x08000003 as above.  Reverse continuing
2509
     from that point should hit B2 as below.  Reading the PC when the
2510
     SIGTRAP is reported should read 0x08000001 and INSN2 should have
2511
     been de-executed already.
2512
 
2513
       B1         0x08000000 :   INSN1
2514
       B2   PC -> 0x08000001 :   INSN2
2515
                  0x08000002 :   INSN3
2516
                  0x08000003 :   INSN4
2517
 
2518
     We can't apply the same logic as for forward execution, because
2519
     we would wrongly adjust the PC to 0x08000000, since there's a
2520
     breakpoint at PC - 1.  We'd then report a hit on B1, although
2521
     INSN1 hadn't been de-executed yet.  Doing nothing is the correct
2522
     behaviour.  */
2523
  if (execution_direction == EXEC_REVERSE)
2524
    return;
2525
 
2526
  /* If this target does not decrement the PC after breakpoints, then
2527
     we have nothing to do.  */
2528
  regcache = get_thread_regcache (ecs->ptid);
2529
  gdbarch = get_regcache_arch (regcache);
2530
  if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2531
    return;
2532
 
2533
  aspace = get_regcache_aspace (regcache);
2534
 
2535
  /* Find the location where (if we've hit a breakpoint) the
2536
     breakpoint would be.  */
2537
  breakpoint_pc = regcache_read_pc (regcache)
2538
                  - gdbarch_decr_pc_after_break (gdbarch);
2539
 
2540
  /* Check whether there actually is a software breakpoint inserted at
2541
     that location.
2542
 
2543
     If in non-stop mode, a race condition is possible where we've
2544
     removed a breakpoint, but stop events for that breakpoint were
2545
     already queued and arrive later.  To suppress those spurious
2546
     SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2547
     and retire them after a number of stop events are reported.  */
2548
  if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
2549
      || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
2550
    {
2551
      struct cleanup *old_cleanups = NULL;
2552
      if (RECORD_IS_USED)
2553
        old_cleanups = record_gdb_operation_disable_set ();
2554
 
2555
      /* When using hardware single-step, a SIGTRAP is reported for both
2556
         a completed single-step and a software breakpoint.  Need to
2557
         differentiate between the two, as the latter needs adjusting
2558
         but the former does not.
2559
 
2560
         The SIGTRAP can be due to a completed hardware single-step only if
2561
          - we didn't insert software single-step breakpoints
2562
          - the thread to be examined is still the current thread
2563
          - this thread is currently being stepped
2564
 
2565
         If any of these events did not occur, we must have stopped due
2566
         to hitting a software breakpoint, and have to back up to the
2567
         breakpoint address.
2568
 
2569
         As a special case, we could have hardware single-stepped a
2570
         software breakpoint.  In this case (prev_pc == breakpoint_pc),
2571
         we also need to back up to the breakpoint address.  */
2572
 
2573
      if (singlestep_breakpoints_inserted_p
2574
          || !ptid_equal (ecs->ptid, inferior_ptid)
2575
          || !currently_stepping (ecs->event_thread)
2576
          || ecs->event_thread->prev_pc == breakpoint_pc)
2577
        regcache_write_pc (regcache, breakpoint_pc);
2578
 
2579
      if (RECORD_IS_USED)
2580
        do_cleanups (old_cleanups);
2581
    }
2582
}
2583
 
2584
void
2585
init_infwait_state (void)
2586
{
2587
  waiton_ptid = pid_to_ptid (-1);
2588
  infwait_state = infwait_normal_state;
2589
}
2590
 
2591
void
2592
error_is_running (void)
2593
{
2594
  error (_("\
2595
Cannot execute this command while the selected thread is running."));
2596
}
2597
 
2598
void
2599
ensure_not_running (void)
2600
{
2601
  if (is_running (inferior_ptid))
2602
    error_is_running ();
2603
}
2604
 
2605
static int
2606
stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
2607
{
2608
  for (frame = get_prev_frame (frame);
2609
       frame != NULL;
2610
       frame = get_prev_frame (frame))
2611
    {
2612
      if (frame_id_eq (get_frame_id (frame), step_frame_id))
2613
        return 1;
2614
      if (get_frame_type (frame) != INLINE_FRAME)
2615
        break;
2616
    }
2617
 
2618
  return 0;
2619
}
2620
 
2621
/* Auxiliary function that handles syscall entry/return events.
2622
   It returns 1 if the inferior should keep going (and GDB
2623
   should ignore the event), or 0 if the event deserves to be
2624
   processed.  */
2625
 
2626
static int
2627
handle_syscall_event (struct execution_control_state *ecs)
2628
{
2629
  struct regcache *regcache;
2630
  struct gdbarch *gdbarch;
2631
  int syscall_number;
2632
 
2633
  if (!ptid_equal (ecs->ptid, inferior_ptid))
2634
    context_switch (ecs->ptid);
2635
 
2636
  regcache = get_thread_regcache (ecs->ptid);
2637
  gdbarch = get_regcache_arch (regcache);
2638
  syscall_number = gdbarch_get_syscall_number (gdbarch, ecs->ptid);
2639
  stop_pc = regcache_read_pc (regcache);
2640
 
2641
  target_last_waitstatus.value.syscall_number = syscall_number;
2642
 
2643
  if (catch_syscall_enabled () > 0
2644
      && catching_syscall_number (syscall_number) > 0)
2645
    {
2646
      if (debug_infrun)
2647
        fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
2648
                            syscall_number);
2649
 
2650
      ecs->event_thread->stop_bpstat
2651
        = bpstat_stop_status (get_regcache_aspace (regcache),
2652
                              stop_pc, ecs->ptid);
2653
      ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
2654
 
2655
      if (!ecs->random_signal)
2656
        {
2657
          /* Catchpoint hit.  */
2658
          ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
2659
          return 0;
2660
        }
2661
    }
2662
 
2663
  /* If no catchpoint triggered for this, then keep going.  */
2664
  ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
2665
  keep_going (ecs);
2666
  return 1;
2667
}
2668
 
2669
/* Given an execution control state that has been freshly filled in
2670
   by an event from the inferior, figure out what it means and take
2671
   appropriate action.  */
2672
 
2673
static void
2674
handle_inferior_event (struct execution_control_state *ecs)
2675
{
2676
  struct frame_info *frame;
2677
  struct gdbarch *gdbarch;
2678
  int sw_single_step_trap_p = 0;
2679
  int stopped_by_watchpoint;
2680
  int stepped_after_stopped_by_watchpoint = 0;
2681
  struct symtab_and_line stop_pc_sal;
2682
  enum stop_kind stop_soon;
2683
 
2684
  if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
2685
    {
2686
      /* We had an event in the inferior, but we are not interested in
2687
         handling it at this level.  The lower layers have already
2688
         done what needs to be done, if anything.
2689
 
2690
         One of the possible circumstances for this is when the
2691
         inferior produces output for the console.  The inferior has
2692
         not stopped, and we are ignoring the event.  Another possible
2693
         circumstance is any event which the lower level knows will be
2694
         reported multiple times without an intervening resume.  */
2695
      if (debug_infrun)
2696
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
2697
      prepare_to_wait (ecs);
2698
      return;
2699
    }
2700
 
2701
  if (ecs->ws.kind != TARGET_WAITKIND_EXITED
2702
      && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2703
    {
2704
      struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2705
      gdb_assert (inf);
2706
      stop_soon = inf->stop_soon;
2707
    }
2708
  else
2709
    stop_soon = NO_STOP_QUIETLY;
2710
 
2711
  /* Cache the last pid/waitstatus. */
2712
  target_last_wait_ptid = ecs->ptid;
2713
  target_last_waitstatus = ecs->ws;
2714
 
2715
  /* Always clear state belonging to the previous time we stopped.  */
2716
  stop_stack_dummy = 0;
2717
 
2718
  /* If it's a new process, add it to the thread database */
2719
 
2720
  ecs->new_thread_event = (!ptid_equal (ecs->ptid, inferior_ptid)
2721
                           && !ptid_equal (ecs->ptid, minus_one_ptid)
2722
                           && !in_thread_list (ecs->ptid));
2723
 
2724
  if (ecs->ws.kind != TARGET_WAITKIND_EXITED
2725
      && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event)
2726
    add_thread (ecs->ptid);
2727
 
2728
  ecs->event_thread = find_thread_ptid (ecs->ptid);
2729
 
2730
  /* Dependent on valid ECS->EVENT_THREAD.  */
2731
  adjust_pc_after_break (ecs);
2732
 
2733
  /* Dependent on the current PC value modified by adjust_pc_after_break.  */
2734
  reinit_frame_cache ();
2735
 
2736
  breakpoint_retire_moribund ();
2737
 
2738
  /* First, distinguish signals caused by the debugger from signals
2739
     that have to do with the program's own actions.  Note that
2740
     breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
2741
     on the operating system version.  Here we detect when a SIGILL or
2742
     SIGEMT is really a breakpoint and change it to SIGTRAP.  We do
2743
     something similar for SIGSEGV, since a SIGSEGV will be generated
2744
     when we're trying to execute a breakpoint instruction on a
2745
     non-executable stack.  This happens for call dummy breakpoints
2746
     for architectures like SPARC that place call dummies on the
2747
     stack.  */
2748
  if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
2749
      && (ecs->ws.value.sig == TARGET_SIGNAL_ILL
2750
          || ecs->ws.value.sig == TARGET_SIGNAL_SEGV
2751
          || ecs->ws.value.sig == TARGET_SIGNAL_EMT))
2752
    {
2753
      struct regcache *regcache = get_thread_regcache (ecs->ptid);
2754
 
2755
      if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2756
                                      regcache_read_pc (regcache)))
2757
        {
2758
          if (debug_infrun)
2759
            fprintf_unfiltered (gdb_stdlog,
2760
                                "infrun: Treating signal as SIGTRAP\n");
2761
          ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
2762
        }
2763
    }
2764
 
2765
  /* Mark the non-executing threads accordingly.  In all-stop, all
2766
     threads of all processes are stopped when we get any event
2767
     reported.  In non-stop mode, only the event thread stops.  If
2768
     we're handling a process exit in non-stop mode, there's nothing
2769
     to do, as threads of the dead process are gone, and threads of
2770
     any other process were left running.  */
2771
  if (!non_stop)
2772
    set_executing (minus_one_ptid, 0);
2773
  else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2774
           && ecs->ws.kind != TARGET_WAITKIND_EXITED)
2775
    set_executing (inferior_ptid, 0);
2776
 
2777
  switch (infwait_state)
2778
    {
2779
    case infwait_thread_hop_state:
2780
      if (debug_infrun)
2781
        fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
2782
      break;
2783
 
2784
    case infwait_normal_state:
2785
      if (debug_infrun)
2786
        fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
2787
      break;
2788
 
2789
    case infwait_step_watch_state:
2790
      if (debug_infrun)
2791
        fprintf_unfiltered (gdb_stdlog,
2792
                            "infrun: infwait_step_watch_state\n");
2793
 
2794
      stepped_after_stopped_by_watchpoint = 1;
2795
      break;
2796
 
2797
    case infwait_nonstep_watch_state:
2798
      if (debug_infrun)
2799
        fprintf_unfiltered (gdb_stdlog,
2800
                            "infrun: infwait_nonstep_watch_state\n");
2801
      insert_breakpoints ();
2802
 
2803
      /* FIXME-maybe: is this cleaner than setting a flag?  Does it
2804
         handle things like signals arriving and other things happening
2805
         in combination correctly?  */
2806
      stepped_after_stopped_by_watchpoint = 1;
2807
      break;
2808
 
2809
    default:
2810
      internal_error (__FILE__, __LINE__, _("bad switch"));
2811
    }
2812
 
2813
  infwait_state = infwait_normal_state;
2814
  waiton_ptid = pid_to_ptid (-1);
2815
 
2816
  switch (ecs->ws.kind)
2817
    {
2818
    case TARGET_WAITKIND_LOADED:
2819
      if (debug_infrun)
2820
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
2821
      /* Ignore gracefully during startup of the inferior, as it might
2822
         be the shell which has just loaded some objects, otherwise
2823
         add the symbols for the newly loaded objects.  Also ignore at
2824
         the beginning of an attach or remote session; we will query
2825
         the full list of libraries once the connection is
2826
         established.  */
2827
      if (stop_soon == NO_STOP_QUIETLY)
2828
        {
2829
          /* Check for any newly added shared libraries if we're
2830
             supposed to be adding them automatically.  Switch
2831
             terminal for any messages produced by
2832
             breakpoint_re_set.  */
2833
          target_terminal_ours_for_output ();
2834
          /* NOTE: cagney/2003-11-25: Make certain that the target
2835
             stack's section table is kept up-to-date.  Architectures,
2836
             (e.g., PPC64), use the section table to perform
2837
             operations such as address => section name and hence
2838
             require the table to contain all sections (including
2839
             those found in shared libraries).  */
2840
#ifdef SOLIB_ADD
2841
          SOLIB_ADD (NULL, 0, &current_target, auto_solib_add);
2842
#else
2843
          solib_add (NULL, 0, &current_target, auto_solib_add);
2844
#endif
2845
          target_terminal_inferior ();
2846
 
2847
          /* If requested, stop when the dynamic linker notifies
2848
             gdb of events.  This allows the user to get control
2849
             and place breakpoints in initializer routines for
2850
             dynamically loaded objects (among other things).  */
2851
          if (stop_on_solib_events)
2852
            {
2853
              /* Make sure we print "Stopped due to solib-event" in
2854
                 normal_stop.  */
2855
              stop_print_frame = 1;
2856
 
2857
              stop_stepping (ecs);
2858
              return;
2859
            }
2860
 
2861
          /* NOTE drow/2007-05-11: This might be a good place to check
2862
             for "catch load".  */
2863
        }
2864
 
2865
      /* If we are skipping through a shell, or through shared library
2866
         loading that we aren't interested in, resume the program.  If
2867
         we're running the program normally, also resume.  But stop if
2868
         we're attaching or setting up a remote connection.  */
2869
      if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
2870
        {
2871
          /* Loading of shared libraries might have changed breakpoint
2872
             addresses.  Make sure new breakpoints are inserted.  */
2873
          if (stop_soon == NO_STOP_QUIETLY
2874
              && !breakpoints_always_inserted_mode ())
2875
            insert_breakpoints ();
2876
          resume (0, TARGET_SIGNAL_0);
2877
          prepare_to_wait (ecs);
2878
          return;
2879
        }
2880
 
2881
      break;
2882
 
2883
    case TARGET_WAITKIND_SPURIOUS:
2884
      if (debug_infrun)
2885
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
2886
      resume (0, TARGET_SIGNAL_0);
2887
      prepare_to_wait (ecs);
2888
      return;
2889
 
2890
    case TARGET_WAITKIND_EXITED:
2891
      if (debug_infrun)
2892
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n");
2893
      inferior_ptid = ecs->ptid;
2894
      set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
2895
      set_current_program_space (current_inferior ()->pspace);
2896
      handle_vfork_child_exec_or_exit (0);
2897
      target_terminal_ours ();  /* Must do this before mourn anyway */
2898
      print_stop_reason (EXITED, ecs->ws.value.integer);
2899
 
2900
      /* Record the exit code in the convenience variable $_exitcode, so
2901
         that the user can inspect this again later.  */
2902
      set_internalvar_integer (lookup_internalvar ("_exitcode"),
2903
                               (LONGEST) ecs->ws.value.integer);
2904
      gdb_flush (gdb_stdout);
2905
      target_mourn_inferior ();
2906
      singlestep_breakpoints_inserted_p = 0;
2907
      stop_print_frame = 0;
2908
      stop_stepping (ecs);
2909
      return;
2910
 
2911
    case TARGET_WAITKIND_SIGNALLED:
2912
      if (debug_infrun)
2913
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n");
2914
      inferior_ptid = ecs->ptid;
2915
      set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
2916
      set_current_program_space (current_inferior ()->pspace);
2917
      handle_vfork_child_exec_or_exit (0);
2918
      stop_print_frame = 0;
2919
      target_terminal_ours ();  /* Must do this before mourn anyway */
2920
 
2921
      /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
2922
         reach here unless the inferior is dead.  However, for years
2923
         target_kill() was called here, which hints that fatal signals aren't
2924
         really fatal on some systems.  If that's true, then some changes
2925
         may be needed. */
2926
      target_mourn_inferior ();
2927
 
2928
      print_stop_reason (SIGNAL_EXITED, ecs->ws.value.sig);
2929
      singlestep_breakpoints_inserted_p = 0;
2930
      stop_stepping (ecs);
2931
      return;
2932
 
2933
      /* The following are the only cases in which we keep going;
2934
         the above cases end in a continue or goto. */
2935
    case TARGET_WAITKIND_FORKED:
2936
    case TARGET_WAITKIND_VFORKED:
2937
      if (debug_infrun)
2938
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
2939
 
2940
      if (!ptid_equal (ecs->ptid, inferior_ptid))
2941
        {
2942
          context_switch (ecs->ptid);
2943
          reinit_frame_cache ();
2944
        }
2945
 
2946
      /* Immediately detach breakpoints from the child before there's
2947
         any chance of letting the user delete breakpoints from the
2948
         breakpoint lists.  If we don't do this early, it's easy to
2949
         leave left over traps in the child, vis: "break foo; catch
2950
         fork; c; <fork>; del; c; <child calls foo>".  We only follow
2951
         the fork on the last `continue', and by that time the
2952
         breakpoint at "foo" is long gone from the breakpoint table.
2953
         If we vforked, then we don't need to unpatch here, since both
2954
         parent and child are sharing the same memory pages; we'll
2955
         need to unpatch at follow/detach time instead to be certain
2956
         that new breakpoints added between catchpoint hit time and
2957
         vfork follow are detached.  */
2958
      if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
2959
        {
2960
          int child_pid = ptid_get_pid (ecs->ws.value.related_pid);
2961
 
2962
          /* This won't actually modify the breakpoint list, but will
2963
             physically remove the breakpoints from the child.  */
2964
          detach_breakpoints (child_pid);
2965
        }
2966
 
2967
      /* In case the event is caught by a catchpoint, remember that
2968
         the event is to be followed at the next resume of the thread,
2969
         and not immediately.  */
2970
      ecs->event_thread->pending_follow = ecs->ws;
2971
 
2972
      stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
2973
 
2974
      ecs->event_thread->stop_bpstat
2975
        = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
2976
                              stop_pc, ecs->ptid);
2977
 
2978
      /* Note that we're interested in knowing the bpstat actually
2979
         causes a stop, not just if it may explain the signal.
2980
         Software watchpoints, for example, always appear in the
2981
         bpstat.  */
2982
      ecs->random_signal = !bpstat_causes_stop (ecs->event_thread->stop_bpstat);
2983
 
2984
      /* If no catchpoint triggered for this, then keep going.  */
2985
      if (ecs->random_signal)
2986
        {
2987
          ptid_t parent;
2988
          ptid_t child;
2989
          int should_resume;
2990
          int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
2991
 
2992
          ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
2993
 
2994
          should_resume = follow_fork ();
2995
 
2996
          parent = ecs->ptid;
2997
          child = ecs->ws.value.related_pid;
2998
 
2999
          /* In non-stop mode, also resume the other branch.  */
3000
          if (non_stop && !detach_fork)
3001
            {
3002
              if (follow_child)
3003
                switch_to_thread (parent);
3004
              else
3005
                switch_to_thread (child);
3006
 
3007
              ecs->event_thread = inferior_thread ();
3008
              ecs->ptid = inferior_ptid;
3009
              keep_going (ecs);
3010
            }
3011
 
3012
          if (follow_child)
3013
            switch_to_thread (child);
3014
          else
3015
            switch_to_thread (parent);
3016
 
3017
          ecs->event_thread = inferior_thread ();
3018
          ecs->ptid = inferior_ptid;
3019
 
3020
          if (should_resume)
3021
            keep_going (ecs);
3022
          else
3023
            stop_stepping (ecs);
3024
          return;
3025
        }
3026
      ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3027
      goto process_event_stop_test;
3028
 
3029
    case TARGET_WAITKIND_VFORK_DONE:
3030
      /* Done with the shared memory region.  Re-insert breakpoints in
3031
         the parent, and keep going.  */
3032
 
3033
      if (debug_infrun)
3034
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3035
 
3036
      if (!ptid_equal (ecs->ptid, inferior_ptid))
3037
        context_switch (ecs->ptid);
3038
 
3039
      current_inferior ()->waiting_for_vfork_done = 0;
3040
      current_inferior ()->pspace->breakpoints_not_allowed = 0;
3041
      /* This also takes care of reinserting breakpoints in the
3042
         previously locked inferior.  */
3043
      keep_going (ecs);
3044
      return;
3045
 
3046
    case TARGET_WAITKIND_EXECD:
3047
      if (debug_infrun)
3048
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3049
 
3050
      if (!ptid_equal (ecs->ptid, inferior_ptid))
3051
        {
3052
          context_switch (ecs->ptid);
3053
          reinit_frame_cache ();
3054
        }
3055
 
3056
      stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3057
 
3058
      /* Do whatever is necessary to the parent branch of the vfork.  */
3059
      handle_vfork_child_exec_or_exit (1);
3060
 
3061
      /* This causes the eventpoints and symbol table to be reset.
3062
         Must do this now, before trying to determine whether to
3063
         stop.  */
3064
      follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3065
 
3066
      ecs->event_thread->stop_bpstat
3067
        = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3068
                              stop_pc, ecs->ptid);
3069
      ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
3070
 
3071
      /* Note that this may be referenced from inside
3072
         bpstat_stop_status above, through inferior_has_execd.  */
3073
      xfree (ecs->ws.value.execd_pathname);
3074
      ecs->ws.value.execd_pathname = NULL;
3075
 
3076
      /* If no catchpoint triggered for this, then keep going.  */
3077
      if (ecs->random_signal)
3078
        {
3079
          ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3080
          keep_going (ecs);
3081
          return;
3082
        }
3083
      ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3084
      goto process_event_stop_test;
3085
 
3086
      /* Be careful not to try to gather much state about a thread
3087
         that's in a syscall.  It's frequently a losing proposition.  */
3088
    case TARGET_WAITKIND_SYSCALL_ENTRY:
3089
      if (debug_infrun)
3090
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3091
      /* Getting the current syscall number */
3092
      if (handle_syscall_event (ecs) != 0)
3093
        return;
3094
      goto process_event_stop_test;
3095
 
3096
      /* Before examining the threads further, step this thread to
3097
         get it entirely out of the syscall.  (We get notice of the
3098
         event when the thread is just on the verge of exiting a
3099
         syscall.  Stepping one instruction seems to get it back
3100
         into user code.)  */
3101
    case TARGET_WAITKIND_SYSCALL_RETURN:
3102
      if (debug_infrun)
3103
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3104
      if (handle_syscall_event (ecs) != 0)
3105
        return;
3106
      goto process_event_stop_test;
3107
 
3108
    case TARGET_WAITKIND_STOPPED:
3109
      if (debug_infrun)
3110
        fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3111
      ecs->event_thread->stop_signal = ecs->ws.value.sig;
3112
      break;
3113
 
3114
    case TARGET_WAITKIND_NO_HISTORY:
3115
      /* Reverse execution: target ran out of history info.  */
3116
      stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3117
      print_stop_reason (NO_HISTORY, 0);
3118
      stop_stepping (ecs);
3119
      return;
3120
    }
3121
 
3122
  if (ecs->new_thread_event)
3123
    {
3124
      if (non_stop)
3125
        /* Non-stop assumes that the target handles adding new threads
3126
           to the thread list.  */
3127
        internal_error (__FILE__, __LINE__, "\
3128
targets should add new threads to the thread list themselves in non-stop mode.");
3129
 
3130
      /* We may want to consider not doing a resume here in order to
3131
         give the user a chance to play with the new thread.  It might
3132
         be good to make that a user-settable option.  */
3133
 
3134
      /* At this point, all threads are stopped (happens automatically
3135
         in either the OS or the native code).  Therefore we need to
3136
         continue all threads in order to make progress.  */
3137
 
3138
      if (!ptid_equal (ecs->ptid, inferior_ptid))
3139
        context_switch (ecs->ptid);
3140
      target_resume (RESUME_ALL, 0, TARGET_SIGNAL_0);
3141
      prepare_to_wait (ecs);
3142
      return;
3143
    }
3144
 
3145
  if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3146
    {
3147
      /* Do we need to clean up the state of a thread that has
3148
         completed a displaced single-step?  (Doing so usually affects
3149
         the PC, so do it here, before we set stop_pc.)  */
3150
      displaced_step_fixup (ecs->ptid, ecs->event_thread->stop_signal);
3151
 
3152
      /* If we either finished a single-step or hit a breakpoint, but
3153
         the user wanted this thread to be stopped, pretend we got a
3154
         SIG0 (generic unsignaled stop).  */
3155
 
3156
      if (ecs->event_thread->stop_requested
3157
          && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3158
        ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3159
    }
3160
 
3161
  stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3162
 
3163
  if (debug_infrun)
3164
    {
3165
      struct regcache *regcache = get_thread_regcache (ecs->ptid);
3166
      struct gdbarch *gdbarch = get_regcache_arch (regcache);
3167
      struct cleanup *old_chain = save_inferior_ptid ();
3168
 
3169
      inferior_ptid = ecs->ptid;
3170
 
3171
      fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3172
                          paddress (gdbarch, stop_pc));
3173
      if (target_stopped_by_watchpoint ())
3174
        {
3175
          CORE_ADDR addr;
3176
          fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3177
 
3178
          if (target_stopped_data_address (&current_target, &addr))
3179
            fprintf_unfiltered (gdb_stdlog,
3180
                                "infrun: stopped data address = %s\n",
3181
                                paddress (gdbarch, addr));
3182
          else
3183
            fprintf_unfiltered (gdb_stdlog,
3184
                                "infrun: (no data address available)\n");
3185
        }
3186
 
3187
      do_cleanups (old_chain);
3188
    }
3189
 
3190
  if (stepping_past_singlestep_breakpoint)
3191
    {
3192
      gdb_assert (singlestep_breakpoints_inserted_p);
3193
      gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3194
      gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3195
 
3196
      stepping_past_singlestep_breakpoint = 0;
3197
 
3198
      /* We've either finished single-stepping past the single-step
3199
         breakpoint, or stopped for some other reason.  It would be nice if
3200
         we could tell, but we can't reliably.  */
3201
      if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3202
        {
3203
          if (debug_infrun)
3204
            fprintf_unfiltered (gdb_stdlog, "infrun: stepping_past_singlestep_breakpoint\n");
3205
          /* Pull the single step breakpoints out of the target.  */
3206
          remove_single_step_breakpoints ();
3207
          singlestep_breakpoints_inserted_p = 0;
3208
 
3209
          ecs->random_signal = 0;
3210
          ecs->event_thread->trap_expected = 0;
3211
 
3212
          context_switch (saved_singlestep_ptid);
3213
          if (deprecated_context_hook)
3214
            deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3215
 
3216
          resume (1, TARGET_SIGNAL_0);
3217
          prepare_to_wait (ecs);
3218
          return;
3219
        }
3220
    }
3221
 
3222
  if (!ptid_equal (deferred_step_ptid, null_ptid))
3223
    {
3224
      /* In non-stop mode, there's never a deferred_step_ptid set.  */
3225
      gdb_assert (!non_stop);
3226
 
3227
      /* If we stopped for some other reason than single-stepping, ignore
3228
         the fact that we were supposed to switch back.  */
3229
      if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3230
        {
3231
          if (debug_infrun)
3232
            fprintf_unfiltered (gdb_stdlog,
3233
                                "infrun: handling deferred step\n");
3234
 
3235
          /* Pull the single step breakpoints out of the target.  */
3236
          if (singlestep_breakpoints_inserted_p)
3237
            {
3238
              remove_single_step_breakpoints ();
3239
              singlestep_breakpoints_inserted_p = 0;
3240
            }
3241
 
3242
          /* Note: We do not call context_switch at this point, as the
3243
             context is already set up for stepping the original thread.  */
3244
          switch_to_thread (deferred_step_ptid);
3245
          deferred_step_ptid = null_ptid;
3246
          /* Suppress spurious "Switching to ..." message.  */
3247
          previous_inferior_ptid = inferior_ptid;
3248
 
3249
          resume (1, TARGET_SIGNAL_0);
3250
          prepare_to_wait (ecs);
3251
          return;
3252
        }
3253
 
3254
      deferred_step_ptid = null_ptid;
3255
    }
3256
 
3257
  /* See if a thread hit a thread-specific breakpoint that was meant for
3258
     another thread.  If so, then step that thread past the breakpoint,
3259
     and continue it.  */
3260
 
3261
  if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3262
    {
3263
      int thread_hop_needed = 0;
3264
      struct address_space *aspace =
3265
        get_regcache_aspace (get_thread_regcache (ecs->ptid));
3266
 
3267
      /* Check if a regular breakpoint has been hit before checking
3268
         for a potential single step breakpoint. Otherwise, GDB will
3269
         not see this breakpoint hit when stepping onto breakpoints.  */
3270
      if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3271
        {
3272
          ecs->random_signal = 0;
3273
          if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3274
            thread_hop_needed = 1;
3275
        }
3276
      else if (singlestep_breakpoints_inserted_p)
3277
        {
3278
          /* We have not context switched yet, so this should be true
3279
             no matter which thread hit the singlestep breakpoint.  */
3280
          gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3281
          if (debug_infrun)
3282
            fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3283
                                "trap for %s\n",
3284
                                target_pid_to_str (ecs->ptid));
3285
 
3286
          ecs->random_signal = 0;
3287
          /* The call to in_thread_list is necessary because PTIDs sometimes
3288
             change when we go from single-threaded to multi-threaded.  If
3289
             the singlestep_ptid is still in the list, assume that it is
3290
             really different from ecs->ptid.  */
3291
          if (!ptid_equal (singlestep_ptid, ecs->ptid)
3292
              && in_thread_list (singlestep_ptid))
3293
            {
3294
              /* If the PC of the thread we were trying to single-step
3295
                 has changed, discard this event (which we were going
3296
                 to ignore anyway), and pretend we saw that thread
3297
                 trap.  This prevents us continuously moving the
3298
                 single-step breakpoint forward, one instruction at a
3299
                 time.  If the PC has changed, then the thread we were
3300
                 trying to single-step has trapped or been signalled,
3301
                 but the event has not been reported to GDB yet.
3302
 
3303
                 There might be some cases where this loses signal
3304
                 information, if a signal has arrived at exactly the
3305
                 same time that the PC changed, but this is the best
3306
                 we can do with the information available.  Perhaps we
3307
                 should arrange to report all events for all threads
3308
                 when they stop, or to re-poll the remote looking for
3309
                 this particular thread (i.e. temporarily enable
3310
                 schedlock).  */
3311
 
3312
             CORE_ADDR new_singlestep_pc
3313
               = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3314
 
3315
             if (new_singlestep_pc != singlestep_pc)
3316
               {
3317
                 enum target_signal stop_signal;
3318
 
3319
                 if (debug_infrun)
3320
                   fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3321
                                       " but expected thread advanced also\n");
3322
 
3323
                 /* The current context still belongs to
3324
                    singlestep_ptid.  Don't swap here, since that's
3325
                    the context we want to use.  Just fudge our
3326
                    state and continue.  */
3327
                 stop_signal = ecs->event_thread->stop_signal;
3328
                 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3329
                 ecs->ptid = singlestep_ptid;
3330
                 ecs->event_thread = find_thread_ptid (ecs->ptid);
3331
                 ecs->event_thread->stop_signal = stop_signal;
3332
                 stop_pc = new_singlestep_pc;
3333
               }
3334
             else
3335
               {
3336
                 if (debug_infrun)
3337
                   fprintf_unfiltered (gdb_stdlog,
3338
                                       "infrun: unexpected thread\n");
3339
 
3340
                 thread_hop_needed = 1;
3341
                 stepping_past_singlestep_breakpoint = 1;
3342
                 saved_singlestep_ptid = singlestep_ptid;
3343
               }
3344
            }
3345
        }
3346
 
3347
      if (thread_hop_needed)
3348
        {
3349
          struct regcache *thread_regcache;
3350
          int remove_status = 0;
3351
 
3352
          if (debug_infrun)
3353
            fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3354
 
3355
          /* Switch context before touching inferior memory, the
3356
             previous thread may have exited.  */
3357
          if (!ptid_equal (inferior_ptid, ecs->ptid))
3358
            context_switch (ecs->ptid);
3359
 
3360
          /* Saw a breakpoint, but it was hit by the wrong thread.
3361
             Just continue. */
3362
 
3363
          if (singlestep_breakpoints_inserted_p)
3364
            {
3365
              /* Pull the single step breakpoints out of the target. */
3366
              remove_single_step_breakpoints ();
3367
              singlestep_breakpoints_inserted_p = 0;
3368
            }
3369
 
3370
          /* If the arch can displace step, don't remove the
3371
             breakpoints.  */
3372
          thread_regcache = get_thread_regcache (ecs->ptid);
3373
          if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3374
            remove_status = remove_breakpoints ();
3375
 
3376
          /* Did we fail to remove breakpoints?  If so, try
3377
             to set the PC past the bp.  (There's at least
3378
             one situation in which we can fail to remove
3379
             the bp's: On HP-UX's that use ttrace, we can't
3380
             change the address space of a vforking child
3381
             process until the child exits (well, okay, not
3382
             then either :-) or execs. */
3383
          if (remove_status != 0)
3384
            error (_("Cannot step over breakpoint hit in wrong thread"));
3385
          else
3386
            {                   /* Single step */
3387
              if (!non_stop)
3388
                {
3389
                  /* Only need to require the next event from this
3390
                     thread in all-stop mode.  */
3391
                  waiton_ptid = ecs->ptid;
3392
                  infwait_state = infwait_thread_hop_state;
3393
                }
3394
 
3395
              ecs->event_thread->stepping_over_breakpoint = 1;
3396
              keep_going (ecs);
3397
              return;
3398
            }
3399
        }
3400
      else if (singlestep_breakpoints_inserted_p)
3401
        {
3402
          sw_single_step_trap_p = 1;
3403
          ecs->random_signal = 0;
3404
        }
3405
    }
3406
  else
3407
    ecs->random_signal = 1;
3408
 
3409
  /* See if something interesting happened to the non-current thread.  If
3410
     so, then switch to that thread.  */
3411
  if (!ptid_equal (ecs->ptid, inferior_ptid))
3412
    {
3413
      if (debug_infrun)
3414
        fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3415
 
3416
      context_switch (ecs->ptid);
3417
 
3418
      if (deprecated_context_hook)
3419
        deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3420
    }
3421
 
3422
  /* At this point, get hold of the now-current thread's frame.  */
3423
  frame = get_current_frame ();
3424
  gdbarch = get_frame_arch (frame);
3425
 
3426
  if (singlestep_breakpoints_inserted_p)
3427
    {
3428
      /* Pull the single step breakpoints out of the target. */
3429
      remove_single_step_breakpoints ();
3430
      singlestep_breakpoints_inserted_p = 0;
3431
    }
3432
 
3433
  if (stepped_after_stopped_by_watchpoint)
3434
    stopped_by_watchpoint = 0;
3435
  else
3436
    stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
3437
 
3438
  /* If necessary, step over this watchpoint.  We'll be back to display
3439
     it in a moment.  */
3440
  if (stopped_by_watchpoint
3441
      && (target_have_steppable_watchpoint
3442
          || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
3443
    {
3444
      /* At this point, we are stopped at an instruction which has
3445
         attempted to write to a piece of memory under control of
3446
         a watchpoint.  The instruction hasn't actually executed
3447
         yet.  If we were to evaluate the watchpoint expression
3448
         now, we would get the old value, and therefore no change
3449
         would seem to have occurred.
3450
 
3451
         In order to make watchpoints work `right', we really need
3452
         to complete the memory write, and then evaluate the
3453
         watchpoint expression.  We do this by single-stepping the
3454
         target.
3455
 
3456
         It may not be necessary to disable the watchpoint to stop over
3457
         it.  For example, the PA can (with some kernel cooperation)
3458
         single step over a watchpoint without disabling the watchpoint.
3459
 
3460
         It is far more common to need to disable a watchpoint to step
3461
         the inferior over it.  If we have non-steppable watchpoints,
3462
         we must disable the current watchpoint; it's simplest to
3463
         disable all watchpoints and breakpoints.  */
3464
      int hw_step = 1;
3465
 
3466
      if (!target_have_steppable_watchpoint)
3467
        remove_breakpoints ();
3468
        /* Single step */
3469
      hw_step = maybe_software_singlestep (gdbarch, stop_pc);
3470
      target_resume (ecs->ptid, hw_step, TARGET_SIGNAL_0);
3471
      waiton_ptid = ecs->ptid;
3472
      if (target_have_steppable_watchpoint)
3473
        infwait_state = infwait_step_watch_state;
3474
      else
3475
        infwait_state = infwait_nonstep_watch_state;
3476
      prepare_to_wait (ecs);
3477
      return;
3478
    }
3479
 
3480
  ecs->stop_func_start = 0;
3481
  ecs->stop_func_end = 0;
3482
  ecs->stop_func_name = 0;
3483
  /* Don't care about return value; stop_func_start and stop_func_name
3484
     will both be 0 if it doesn't work.  */
3485
  find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3486
                            &ecs->stop_func_start, &ecs->stop_func_end);
3487
  ecs->stop_func_start
3488
    += gdbarch_deprecated_function_start_offset (gdbarch);
3489
  ecs->event_thread->stepping_over_breakpoint = 0;
3490
  bpstat_clear (&ecs->event_thread->stop_bpstat);
3491
  ecs->event_thread->stop_step = 0;
3492
  stop_print_frame = 1;
3493
  ecs->random_signal = 0;
3494
  stopped_by_random_signal = 0;
3495
 
3496
  /* Hide inlined functions starting here, unless we just performed stepi or
3497
     nexti.  After stepi and nexti, always show the innermost frame (not any
3498
     inline function call sites).  */
3499
  if (ecs->event_thread->step_range_end != 1)
3500
    skip_inline_frames (ecs->ptid);
3501
 
3502
  if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3503
      && ecs->event_thread->trap_expected
3504
      && gdbarch_single_step_through_delay_p (gdbarch)
3505
      && currently_stepping (ecs->event_thread))
3506
    {
3507
      /* We're trying to step off a breakpoint.  Turns out that we're
3508
         also on an instruction that needs to be stepped multiple
3509
         times before it's been fully executing. E.g., architectures
3510
         with a delay slot.  It needs to be stepped twice, once for
3511
         the instruction and once for the delay slot.  */
3512
      int step_through_delay
3513
        = gdbarch_single_step_through_delay (gdbarch, frame);
3514
      if (debug_infrun && step_through_delay)
3515
        fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
3516
      if (ecs->event_thread->step_range_end == 0 && step_through_delay)
3517
        {
3518
          /* The user issued a continue when stopped at a breakpoint.
3519
             Set up for another trap and get out of here.  */
3520
         ecs->event_thread->stepping_over_breakpoint = 1;
3521
         keep_going (ecs);
3522
         return;
3523
        }
3524
      else if (step_through_delay)
3525
        {
3526
          /* The user issued a step when stopped at a breakpoint.
3527
             Maybe we should stop, maybe we should not - the delay
3528
             slot *might* correspond to a line of source.  In any
3529
             case, don't decide that here, just set
3530
             ecs->stepping_over_breakpoint, making sure we
3531
             single-step again before breakpoints are re-inserted.  */
3532
          ecs->event_thread->stepping_over_breakpoint = 1;
3533
        }
3534
    }
3535
 
3536
  /* Look at the cause of the stop, and decide what to do.
3537
     The alternatives are:
3538
     1) stop_stepping and return; to really stop and return to the debugger,
3539
     2) keep_going and return to start up again
3540
     (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3541
     3) set ecs->random_signal to 1, and the decision between 1 and 2
3542
     will be made according to the signal handling tables.  */
3543
 
3544
  if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3545
      || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
3546
      || stop_soon == STOP_QUIETLY_REMOTE)
3547
    {
3548
      if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP && stop_after_trap)
3549
        {
3550
          if (debug_infrun)
3551
            fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
3552
          stop_print_frame = 0;
3553
          stop_stepping (ecs);
3554
          return;
3555
        }
3556
 
3557
      /* This is originated from start_remote(), start_inferior() and
3558
         shared libraries hook functions.  */
3559
      if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
3560
        {
3561
          if (debug_infrun)
3562
            fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3563
          stop_stepping (ecs);
3564
          return;
3565
        }
3566
 
3567
      /* This originates from attach_command().  We need to overwrite
3568
         the stop_signal here, because some kernels don't ignore a
3569
         SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
3570
         See more comments in inferior.h.  On the other hand, if we
3571
         get a non-SIGSTOP, report it to the user - assume the backend
3572
         will handle the SIGSTOP if it should show up later.
3573
 
3574
         Also consider that the attach is complete when we see a
3575
         SIGTRAP.  Some systems (e.g. Windows), and stubs supporting
3576
         target extended-remote report it instead of a SIGSTOP
3577
         (e.g. gdbserver).  We already rely on SIGTRAP being our
3578
         signal, so this is no exception.
3579
 
3580
         Also consider that the attach is complete when we see a
3581
         TARGET_SIGNAL_0.  In non-stop mode, GDB will explicitly tell
3582
         the target to stop all threads of the inferior, in case the
3583
         low level attach operation doesn't stop them implicitly.  If
3584
         they weren't stopped implicitly, then the stub will report a
3585
         TARGET_SIGNAL_0, meaning: stopped for no particular reason
3586
         other than GDB's request.  */
3587
      if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3588
          && (ecs->event_thread->stop_signal == TARGET_SIGNAL_STOP
3589
              || ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3590
              || ecs->event_thread->stop_signal == TARGET_SIGNAL_0))
3591
        {
3592
          stop_stepping (ecs);
3593
          ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3594
          return;
3595
        }
3596
 
3597
      /* See if there is a breakpoint at the current PC.  */
3598
      ecs->event_thread->stop_bpstat
3599
        = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3600
                              stop_pc, ecs->ptid);
3601
 
3602
      /* Following in case break condition called a
3603
         function.  */
3604
      stop_print_frame = 1;
3605
 
3606
      /* This is where we handle "moribund" watchpoints.  Unlike
3607
         software breakpoints traps, hardware watchpoint traps are
3608
         always distinguishable from random traps.  If no high-level
3609
         watchpoint is associated with the reported stop data address
3610
         anymore, then the bpstat does not explain the signal ---
3611
         simply make sure to ignore it if `stopped_by_watchpoint' is
3612
         set.  */
3613
 
3614
      if (debug_infrun
3615
          && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3616
          && !bpstat_explains_signal (ecs->event_thread->stop_bpstat)
3617
          && stopped_by_watchpoint)
3618
        fprintf_unfiltered (gdb_stdlog, "\
3619
infrun: no user watchpoint explains watchpoint SIGTRAP, ignoring\n");
3620
 
3621
      /* NOTE: cagney/2003-03-29: These two checks for a random signal
3622
         at one stage in the past included checks for an inferior
3623
         function call's call dummy's return breakpoint.  The original
3624
         comment, that went with the test, read:
3625
 
3626
         ``End of a stack dummy.  Some systems (e.g. Sony news) give
3627
         another signal besides SIGTRAP, so check here as well as
3628
         above.''
3629
 
3630
         If someone ever tries to get call dummys on a
3631
         non-executable stack to work (where the target would stop
3632
         with something like a SIGSEGV), then those tests might need
3633
         to be re-instated.  Given, however, that the tests were only
3634
         enabled when momentary breakpoints were not being used, I
3635
         suspect that it won't be the case.
3636
 
3637
         NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
3638
         be necessary for call dummies on a non-executable stack on
3639
         SPARC.  */
3640
 
3641
      if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3642
        ecs->random_signal
3643
          = !(bpstat_explains_signal (ecs->event_thread->stop_bpstat)
3644
              || stopped_by_watchpoint
3645
              || ecs->event_thread->trap_expected
3646
              || (ecs->event_thread->step_range_end
3647
                  && ecs->event_thread->step_resume_breakpoint == NULL));
3648
      else
3649
        {
3650
          ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
3651
          if (!ecs->random_signal)
3652
            ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3653
        }
3654
    }
3655
 
3656
  /* When we reach this point, we've pretty much decided
3657
     that the reason for stopping must've been a random
3658
     (unexpected) signal. */
3659
 
3660
  else
3661
    ecs->random_signal = 1;
3662
 
3663
process_event_stop_test:
3664
 
3665
  /* Re-fetch current thread's frame in case we did a
3666
     "goto process_event_stop_test" above.  */
3667
  frame = get_current_frame ();
3668
  gdbarch = get_frame_arch (frame);
3669
 
3670
  /* For the program's own signals, act according to
3671
     the signal handling tables.  */
3672
 
3673
  if (ecs->random_signal)
3674
    {
3675
      /* Signal not for debugging purposes.  */
3676
      int printed = 0;
3677
 
3678
      if (debug_infrun)
3679
         fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
3680
                             ecs->event_thread->stop_signal);
3681
 
3682
      stopped_by_random_signal = 1;
3683
 
3684
      if (signal_print[ecs->event_thread->stop_signal])
3685
        {
3686
          printed = 1;
3687
          target_terminal_ours_for_output ();
3688
          print_stop_reason (SIGNAL_RECEIVED, ecs->event_thread->stop_signal);
3689
        }
3690
      /* Always stop on signals if we're either just gaining control
3691
         of the program, or the user explicitly requested this thread
3692
         to remain stopped.  */
3693
      if (stop_soon != NO_STOP_QUIETLY
3694
          || ecs->event_thread->stop_requested
3695
          || signal_stop_state (ecs->event_thread->stop_signal))
3696
        {
3697
          stop_stepping (ecs);
3698
          return;
3699
        }
3700
      /* If not going to stop, give terminal back
3701
         if we took it away.  */
3702
      else if (printed)
3703
        target_terminal_inferior ();
3704
 
3705
      /* Clear the signal if it should not be passed.  */
3706
      if (signal_program[ecs->event_thread->stop_signal] == 0)
3707
        ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3708
 
3709
      if (ecs->event_thread->prev_pc == stop_pc
3710
          && ecs->event_thread->trap_expected
3711
          && ecs->event_thread->step_resume_breakpoint == NULL)
3712
        {
3713
          /* We were just starting a new sequence, attempting to
3714
             single-step off of a breakpoint and expecting a SIGTRAP.
3715
             Instead this signal arrives.  This signal will take us out
3716
             of the stepping range so GDB needs to remember to, when
3717
             the signal handler returns, resume stepping off that
3718
             breakpoint.  */
3719
          /* To simplify things, "continue" is forced to use the same
3720
             code paths as single-step - set a breakpoint at the
3721
             signal return address and then, once hit, step off that
3722
             breakpoint.  */
3723
          if (debug_infrun)
3724
            fprintf_unfiltered (gdb_stdlog,
3725
                                "infrun: signal arrived while stepping over "
3726
                                "breakpoint\n");
3727
 
3728
          insert_step_resume_breakpoint_at_frame (frame);
3729
          ecs->event_thread->step_after_step_resume_breakpoint = 1;
3730
          keep_going (ecs);
3731
          return;
3732
        }
3733
 
3734
      if (ecs->event_thread->step_range_end != 0
3735
          && ecs->event_thread->stop_signal != TARGET_SIGNAL_0
3736
          && (ecs->event_thread->step_range_start <= stop_pc
3737
              && stop_pc < ecs->event_thread->step_range_end)
3738
          && frame_id_eq (get_stack_frame_id (frame),
3739
                          ecs->event_thread->step_stack_frame_id)
3740
          && ecs->event_thread->step_resume_breakpoint == NULL)
3741
        {
3742
          /* The inferior is about to take a signal that will take it
3743
             out of the single step range.  Set a breakpoint at the
3744
             current PC (which is presumably where the signal handler
3745
             will eventually return) and then allow the inferior to
3746
             run free.
3747
 
3748
             Note that this is only needed for a signal delivered
3749
             while in the single-step range.  Nested signals aren't a
3750
             problem as they eventually all return.  */
3751
          if (debug_infrun)
3752
            fprintf_unfiltered (gdb_stdlog,
3753
                                "infrun: signal may take us out of "
3754
                                "single-step range\n");
3755
 
3756
          insert_step_resume_breakpoint_at_frame (frame);
3757
          keep_going (ecs);
3758
          return;
3759
        }
3760
 
3761
      /* Note: step_resume_breakpoint may be non-NULL.  This occures
3762
         when either there's a nested signal, or when there's a
3763
         pending signal enabled just as the signal handler returns
3764
         (leaving the inferior at the step-resume-breakpoint without
3765
         actually executing it).  Either way continue until the
3766
         breakpoint is really hit.  */
3767
      keep_going (ecs);
3768
      return;
3769
    }
3770
 
3771
  /* Handle cases caused by hitting a breakpoint.  */
3772
  {
3773
    CORE_ADDR jmp_buf_pc;
3774
    struct bpstat_what what;
3775
 
3776
    what = bpstat_what (ecs->event_thread->stop_bpstat);
3777
 
3778
    if (what.call_dummy)
3779
      {
3780
        stop_stack_dummy = 1;
3781
      }
3782
 
3783
    switch (what.main_action)
3784
      {
3785
      case BPSTAT_WHAT_SET_LONGJMP_RESUME:
3786
        /* If we hit the breakpoint at longjmp while stepping, we
3787
           install a momentary breakpoint at the target of the
3788
           jmp_buf.  */
3789
 
3790
        if (debug_infrun)
3791
          fprintf_unfiltered (gdb_stdlog,
3792
                              "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
3793
 
3794
        ecs->event_thread->stepping_over_breakpoint = 1;
3795
 
3796
        if (!gdbarch_get_longjmp_target_p (gdbarch)
3797
            || !gdbarch_get_longjmp_target (gdbarch, frame, &jmp_buf_pc))
3798
          {
3799
            if (debug_infrun)
3800
              fprintf_unfiltered (gdb_stdlog, "\
3801
infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n");
3802
            keep_going (ecs);
3803
            return;
3804
          }
3805
 
3806
        /* We're going to replace the current step-resume breakpoint
3807
           with a longjmp-resume breakpoint.  */
3808
        delete_step_resume_breakpoint (ecs->event_thread);
3809
 
3810
        /* Insert a breakpoint at resume address.  */
3811
        insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
3812
 
3813
        keep_going (ecs);
3814
        return;
3815
 
3816
      case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
3817
        if (debug_infrun)
3818
          fprintf_unfiltered (gdb_stdlog,
3819
                              "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
3820
 
3821
        gdb_assert (ecs->event_thread->step_resume_breakpoint != NULL);
3822
        delete_step_resume_breakpoint (ecs->event_thread);
3823
 
3824
        ecs->event_thread->stop_step = 1;
3825
        print_stop_reason (END_STEPPING_RANGE, 0);
3826
        stop_stepping (ecs);
3827
        return;
3828
 
3829
      case BPSTAT_WHAT_SINGLE:
3830
        if (debug_infrun)
3831
          fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
3832
        ecs->event_thread->stepping_over_breakpoint = 1;
3833
        /* Still need to check other stuff, at least the case
3834
           where we are stepping and step out of the right range.  */
3835
        break;
3836
 
3837
      case BPSTAT_WHAT_STOP_NOISY:
3838
        if (debug_infrun)
3839
          fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
3840
        stop_print_frame = 1;
3841
 
3842
        /* We are about to nuke the step_resume_breakpointt via the
3843
           cleanup chain, so no need to worry about it here.  */
3844
 
3845
        stop_stepping (ecs);
3846
        return;
3847
 
3848
      case BPSTAT_WHAT_STOP_SILENT:
3849
        if (debug_infrun)
3850
          fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
3851
        stop_print_frame = 0;
3852
 
3853
        /* We are about to nuke the step_resume_breakpoin via the
3854
           cleanup chain, so no need to worry about it here.  */
3855
 
3856
        stop_stepping (ecs);
3857
        return;
3858
 
3859
      case BPSTAT_WHAT_STEP_RESUME:
3860
        if (debug_infrun)
3861
          fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
3862
 
3863
        delete_step_resume_breakpoint (ecs->event_thread);
3864
        if (ecs->event_thread->step_after_step_resume_breakpoint)
3865
          {
3866
            /* Back when the step-resume breakpoint was inserted, we
3867
               were trying to single-step off a breakpoint.  Go back
3868
               to doing that.  */
3869
            ecs->event_thread->step_after_step_resume_breakpoint = 0;
3870
            ecs->event_thread->stepping_over_breakpoint = 1;
3871
            keep_going (ecs);
3872
            return;
3873
          }
3874
        if (stop_pc == ecs->stop_func_start
3875
            && execution_direction == EXEC_REVERSE)
3876
          {
3877
            /* We are stepping over a function call in reverse, and
3878
               just hit the step-resume breakpoint at the start
3879
               address of the function.  Go back to single-stepping,
3880
               which should take us back to the function call.  */
3881
            ecs->event_thread->stepping_over_breakpoint = 1;
3882
            keep_going (ecs);
3883
            return;
3884
          }
3885
        break;
3886
 
3887
      case BPSTAT_WHAT_CHECK_SHLIBS:
3888
        {
3889
          if (debug_infrun)
3890
            fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
3891
 
3892
          /* Check for any newly added shared libraries if we're
3893
             supposed to be adding them automatically.  Switch
3894
             terminal for any messages produced by
3895
             breakpoint_re_set.  */
3896
          target_terminal_ours_for_output ();
3897
          /* NOTE: cagney/2003-11-25: Make certain that the target
3898
             stack's section table is kept up-to-date.  Architectures,
3899
             (e.g., PPC64), use the section table to perform
3900
             operations such as address => section name and hence
3901
             require the table to contain all sections (including
3902
             those found in shared libraries).  */
3903
#ifdef SOLIB_ADD
3904
          SOLIB_ADD (NULL, 0, &current_target, auto_solib_add);
3905
#else
3906
          solib_add (NULL, 0, &current_target, auto_solib_add);
3907
#endif
3908
          target_terminal_inferior ();
3909
 
3910
          /* If requested, stop when the dynamic linker notifies
3911
             gdb of events.  This allows the user to get control
3912
             and place breakpoints in initializer routines for
3913
             dynamically loaded objects (among other things).  */
3914
          if (stop_on_solib_events || stop_stack_dummy)
3915
            {
3916
              stop_stepping (ecs);
3917
              return;
3918
            }
3919
          else
3920
            {
3921
              /* We want to step over this breakpoint, then keep going.  */
3922
              ecs->event_thread->stepping_over_breakpoint = 1;
3923
              break;
3924
            }
3925
        }
3926
        break;
3927
 
3928
      case BPSTAT_WHAT_CHECK_JIT:
3929
        if (debug_infrun)
3930
          fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_JIT\n");
3931
 
3932
        /* Switch terminal for any messages produced by breakpoint_re_set.  */
3933
        target_terminal_ours_for_output ();
3934
 
3935
        jit_event_handler (gdbarch);
3936
 
3937
        target_terminal_inferior ();
3938
 
3939
        /* We want to step over this breakpoint, then keep going.  */
3940
        ecs->event_thread->stepping_over_breakpoint = 1;
3941
 
3942
        break;
3943
 
3944
      case BPSTAT_WHAT_LAST:
3945
        /* Not a real code, but listed here to shut up gcc -Wall.  */
3946
 
3947
      case BPSTAT_WHAT_KEEP_CHECKING:
3948
        break;
3949
      }
3950
  }
3951
 
3952
  /* We come here if we hit a breakpoint but should not
3953
     stop for it.  Possibly we also were stepping
3954
     and should stop for that.  So fall through and
3955
     test for stepping.  But, if not stepping,
3956
     do not stop.  */
3957
 
3958
  /* In all-stop mode, if we're currently stepping but have stopped in
3959
     some other thread, we need to switch back to the stepped thread.  */
3960
  if (!non_stop)
3961
    {
3962
      struct thread_info *tp;
3963
      tp = iterate_over_threads (currently_stepping_or_nexting_callback,
3964
                                 ecs->event_thread);
3965
      if (tp)
3966
        {
3967
          /* However, if the current thread is blocked on some internal
3968
             breakpoint, and we simply need to step over that breakpoint
3969
             to get it going again, do that first.  */
3970
          if ((ecs->event_thread->trap_expected
3971
               && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP)
3972
              || ecs->event_thread->stepping_over_breakpoint)
3973
            {
3974
              keep_going (ecs);
3975
              return;
3976
            }
3977
 
3978
          /* If the stepping thread exited, then don't try to switch
3979
             back and resume it, which could fail in several different
3980
             ways depending on the target.  Instead, just keep going.
3981
 
3982
             We can find a stepping dead thread in the thread list in
3983
             two cases:
3984
 
3985
             - The target supports thread exit events, and when the
3986
             target tries to delete the thread from the thread list,
3987
             inferior_ptid pointed at the exiting thread.  In such
3988
             case, calling delete_thread does not really remove the
3989
             thread from the list; instead, the thread is left listed,
3990
             with 'exited' state.
3991
 
3992
             - The target's debug interface does not support thread
3993
             exit events, and so we have no idea whatsoever if the
3994
             previously stepping thread is still alive.  For that
3995
             reason, we need to synchronously query the target
3996
             now.  */
3997
          if (is_exited (tp->ptid)
3998
              || !target_thread_alive (tp->ptid))
3999
            {
4000
              if (debug_infrun)
4001
                fprintf_unfiltered (gdb_stdlog, "\
4002
infrun: not switching back to stepped thread, it has vanished\n");
4003
 
4004
              delete_thread (tp->ptid);
4005
              keep_going (ecs);
4006
              return;
4007
            }
4008
 
4009
          /* Otherwise, we no longer expect a trap in the current thread.
4010
             Clear the trap_expected flag before switching back -- this is
4011
             what keep_going would do as well, if we called it.  */
4012
          ecs->event_thread->trap_expected = 0;
4013
 
4014
          if (debug_infrun)
4015
            fprintf_unfiltered (gdb_stdlog,
4016
                                "infrun: switching back to stepped thread\n");
4017
 
4018
          ecs->event_thread = tp;
4019
          ecs->ptid = tp->ptid;
4020
          context_switch (ecs->ptid);
4021
          keep_going (ecs);
4022
          return;
4023
        }
4024
    }
4025
 
4026
  /* Are we stepping to get the inferior out of the dynamic linker's
4027
     hook (and possibly the dld itself) after catching a shlib
4028
     event?  */
4029
  if (ecs->event_thread->stepping_through_solib_after_catch)
4030
    {
4031
#if defined(SOLIB_ADD)
4032
      /* Have we reached our destination?  If not, keep going. */
4033
      if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs->ptid), stop_pc))
4034
        {
4035
          if (debug_infrun)
4036
            fprintf_unfiltered (gdb_stdlog, "infrun: stepping in dynamic linker\n");
4037
          ecs->event_thread->stepping_over_breakpoint = 1;
4038
          keep_going (ecs);
4039
          return;
4040
        }
4041
#endif
4042
      if (debug_infrun)
4043
         fprintf_unfiltered (gdb_stdlog, "infrun: step past dynamic linker\n");
4044
      /* Else, stop and report the catchpoint(s) whose triggering
4045
         caused us to begin stepping. */
4046
      ecs->event_thread->stepping_through_solib_after_catch = 0;
4047
      bpstat_clear (&ecs->event_thread->stop_bpstat);
4048
      ecs->event_thread->stop_bpstat
4049
        = bpstat_copy (ecs->event_thread->stepping_through_solib_catchpoints);
4050
      bpstat_clear (&ecs->event_thread->stepping_through_solib_catchpoints);
4051
      stop_print_frame = 1;
4052
      stop_stepping (ecs);
4053
      return;
4054
    }
4055
 
4056
  if (ecs->event_thread->step_resume_breakpoint)
4057
    {
4058
      if (debug_infrun)
4059
         fprintf_unfiltered (gdb_stdlog,
4060
                             "infrun: step-resume breakpoint is inserted\n");
4061
 
4062
      /* Having a step-resume breakpoint overrides anything
4063
         else having to do with stepping commands until
4064
         that breakpoint is reached.  */
4065
      keep_going (ecs);
4066
      return;
4067
    }
4068
 
4069
  if (ecs->event_thread->step_range_end == 0)
4070
    {
4071
      if (debug_infrun)
4072
         fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4073
      /* Likewise if we aren't even stepping.  */
4074
      keep_going (ecs);
4075
      return;
4076
    }
4077
 
4078
  /* Re-fetch current thread's frame in case the code above caused
4079
     the frame cache to be re-initialized, making our FRAME variable
4080
     a dangling pointer.  */
4081
  frame = get_current_frame ();
4082
 
4083
  /* If stepping through a line, keep going if still within it.
4084
 
4085
     Note that step_range_end is the address of the first instruction
4086
     beyond the step range, and NOT the address of the last instruction
4087
     within it!
4088
 
4089
     Note also that during reverse execution, we may be stepping
4090
     through a function epilogue and therefore must detect when
4091
     the current-frame changes in the middle of a line.  */
4092
 
4093
  if (stop_pc >= ecs->event_thread->step_range_start
4094
      && stop_pc < ecs->event_thread->step_range_end
4095
      && (execution_direction != EXEC_REVERSE
4096
          || frame_id_eq (get_frame_id (frame),
4097
                          ecs->event_thread->step_frame_id)))
4098
    {
4099
      if (debug_infrun)
4100
        fprintf_unfiltered
4101
          (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4102
           paddress (gdbarch, ecs->event_thread->step_range_start),
4103
           paddress (gdbarch, ecs->event_thread->step_range_end));
4104
 
4105
      /* When stepping backward, stop at beginning of line range
4106
         (unless it's the function entry point, in which case
4107
         keep going back to the call point).  */
4108
      if (stop_pc == ecs->event_thread->step_range_start
4109
          && stop_pc != ecs->stop_func_start
4110
          && execution_direction == EXEC_REVERSE)
4111
        {
4112
          ecs->event_thread->stop_step = 1;
4113
          print_stop_reason (END_STEPPING_RANGE, 0);
4114
          stop_stepping (ecs);
4115
        }
4116
      else
4117
        keep_going (ecs);
4118
 
4119
      return;
4120
    }
4121
 
4122
  /* We stepped out of the stepping range.  */
4123
 
4124
  /* If we are stepping at the source level and entered the runtime
4125
     loader dynamic symbol resolution code...
4126
 
4127
     EXEC_FORWARD: we keep on single stepping until we exit the run
4128
     time loader code and reach the callee's address.
4129
 
4130
     EXEC_REVERSE: we've already executed the callee (backward), and
4131
     the runtime loader code is handled just like any other
4132
     undebuggable function call.  Now we need only keep stepping
4133
     backward through the trampoline code, and that's handled further
4134
     down, so there is nothing for us to do here.  */
4135
 
4136
  if (execution_direction != EXEC_REVERSE
4137
      && ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4138
      && in_solib_dynsym_resolve_code (stop_pc))
4139
    {
4140
      CORE_ADDR pc_after_resolver =
4141
        gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4142
 
4143
      if (debug_infrun)
4144
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into dynsym resolve code\n");
4145
 
4146
      if (pc_after_resolver)
4147
        {
4148
          /* Set up a step-resume breakpoint at the address
4149
             indicated by SKIP_SOLIB_RESOLVER.  */
4150
          struct symtab_and_line sr_sal;
4151
          init_sal (&sr_sal);
4152
          sr_sal.pc = pc_after_resolver;
4153
          sr_sal.pspace = get_frame_program_space (frame);
4154
 
4155
          insert_step_resume_breakpoint_at_sal (gdbarch,
4156
                                                sr_sal, null_frame_id);
4157
        }
4158
 
4159
      keep_going (ecs);
4160
      return;
4161
    }
4162
 
4163
  if (ecs->event_thread->step_range_end != 1
4164
      && (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4165
          || ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4166
      && get_frame_type (frame) == SIGTRAMP_FRAME)
4167
    {
4168
      if (debug_infrun)
4169
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into signal trampoline\n");
4170
      /* The inferior, while doing a "step" or "next", has ended up in
4171
         a signal trampoline (either by a signal being delivered or by
4172
         the signal handler returning).  Just single-step until the
4173
         inferior leaves the trampoline (either by calling the handler
4174
         or returning).  */
4175
      keep_going (ecs);
4176
      return;
4177
    }
4178
 
4179
  /* Check for subroutine calls.  The check for the current frame
4180
     equalling the step ID is not necessary - the check of the
4181
     previous frame's ID is sufficient - but it is a common case and
4182
     cheaper than checking the previous frame's ID.
4183
 
4184
     NOTE: frame_id_eq will never report two invalid frame IDs as
4185
     being equal, so to get into this block, both the current and
4186
     previous frame must have valid frame IDs.  */
4187
  /* The outer_frame_id check is a heuristic to detect stepping
4188
     through startup code.  If we step over an instruction which
4189
     sets the stack pointer from an invalid value to a valid value,
4190
     we may detect that as a subroutine call from the mythical
4191
     "outermost" function.  This could be fixed by marking
4192
     outermost frames as !stack_p,code_p,special_p.  Then the
4193
     initial outermost frame, before sp was valid, would
4194
     have code_addr == &_start.  See the comment in frame_id_eq
4195
     for more.  */
4196
  if (!frame_id_eq (get_stack_frame_id (frame),
4197
                    ecs->event_thread->step_stack_frame_id)
4198
      && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4199
                       ecs->event_thread->step_stack_frame_id)
4200
          && (!frame_id_eq (ecs->event_thread->step_stack_frame_id,
4201
                            outer_frame_id)
4202
              || step_start_function != find_pc_function (stop_pc))))
4203
    {
4204
      CORE_ADDR real_stop_pc;
4205
 
4206
      if (debug_infrun)
4207
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4208
 
4209
      if ((ecs->event_thread->step_over_calls == STEP_OVER_NONE)
4210
          || ((ecs->event_thread->step_range_end == 1)
4211
              && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4212
                              ecs->stop_func_start)))
4213
        {
4214
          /* I presume that step_over_calls is only 0 when we're
4215
             supposed to be stepping at the assembly language level
4216
             ("stepi").  Just stop.  */
4217
          /* Also, maybe we just did a "nexti" inside a prolog, so we
4218
             thought it was a subroutine call but it was not.  Stop as
4219
             well.  FENN */
4220
          /* And this works the same backward as frontward.  MVS */
4221
          ecs->event_thread->stop_step = 1;
4222
          print_stop_reason (END_STEPPING_RANGE, 0);
4223
          stop_stepping (ecs);
4224
          return;
4225
        }
4226
 
4227
      /* Reverse stepping through solib trampolines.  */
4228
 
4229
      if (execution_direction == EXEC_REVERSE
4230
          && ecs->event_thread->step_over_calls != STEP_OVER_NONE
4231
          && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4232
              || (ecs->stop_func_start == 0
4233
                  && in_solib_dynsym_resolve_code (stop_pc))))
4234
        {
4235
          /* Any solib trampoline code can be handled in reverse
4236
             by simply continuing to single-step.  We have already
4237
             executed the solib function (backwards), and a few
4238
             steps will take us back through the trampoline to the
4239
             caller.  */
4240
          keep_going (ecs);
4241
          return;
4242
        }
4243
 
4244
      if (ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4245
        {
4246
          /* We're doing a "next".
4247
 
4248
             Normal (forward) execution: set a breakpoint at the
4249
             callee's return address (the address at which the caller
4250
             will resume).
4251
 
4252
             Reverse (backward) execution.  set the step-resume
4253
             breakpoint at the start of the function that we just
4254
             stepped into (backwards), and continue to there.  When we
4255
             get there, we'll need to single-step back to the caller.  */
4256
 
4257
          if (execution_direction == EXEC_REVERSE)
4258
            {
4259
              struct symtab_and_line sr_sal;
4260
 
4261
              /* Normal function call return (static or dynamic).  */
4262
              init_sal (&sr_sal);
4263
              sr_sal.pc = ecs->stop_func_start;
4264
              sr_sal.pspace = get_frame_program_space (frame);
4265
              insert_step_resume_breakpoint_at_sal (gdbarch,
4266
                                                    sr_sal, null_frame_id);
4267
            }
4268
          else
4269
            insert_step_resume_breakpoint_at_caller (frame);
4270
 
4271
          keep_going (ecs);
4272
          return;
4273
        }
4274
 
4275
      /* If we are in a function call trampoline (a stub between the
4276
         calling routine and the real function), locate the real
4277
         function.  That's what tells us (a) whether we want to step
4278
         into it at all, and (b) what prologue we want to run to the
4279
         end of, if we do step into it.  */
4280
      real_stop_pc = skip_language_trampoline (frame, stop_pc);
4281
      if (real_stop_pc == 0)
4282
        real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4283
      if (real_stop_pc != 0)
4284
        ecs->stop_func_start = real_stop_pc;
4285
 
4286
      if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4287
        {
4288
          struct symtab_and_line sr_sal;
4289
          init_sal (&sr_sal);
4290
          sr_sal.pc = ecs->stop_func_start;
4291
          sr_sal.pspace = get_frame_program_space (frame);
4292
 
4293
          insert_step_resume_breakpoint_at_sal (gdbarch,
4294
                                                sr_sal, null_frame_id);
4295
          keep_going (ecs);
4296
          return;
4297
        }
4298
 
4299
      /* If we have line number information for the function we are
4300
         thinking of stepping into, step into it.
4301
 
4302
         If there are several symtabs at that PC (e.g. with include
4303
         files), just want to know whether *any* of them have line
4304
         numbers.  find_pc_line handles this.  */
4305
      {
4306
        struct symtab_and_line tmp_sal;
4307
 
4308
        tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4309
        tmp_sal.pspace = get_frame_program_space (frame);
4310
        if (tmp_sal.line != 0)
4311
          {
4312
            if (execution_direction == EXEC_REVERSE)
4313
              handle_step_into_function_backward (gdbarch, ecs);
4314
            else
4315
              handle_step_into_function (gdbarch, ecs);
4316
            return;
4317
          }
4318
      }
4319
 
4320
      /* If we have no line number and the step-stop-if-no-debug is
4321
         set, we stop the step so that the user has a chance to switch
4322
         in assembly mode.  */
4323
      if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4324
          && step_stop_if_no_debug)
4325
        {
4326
          ecs->event_thread->stop_step = 1;
4327
          print_stop_reason (END_STEPPING_RANGE, 0);
4328
          stop_stepping (ecs);
4329
          return;
4330
        }
4331
 
4332
      if (execution_direction == EXEC_REVERSE)
4333
        {
4334
          /* Set a breakpoint at callee's start address.
4335
             From there we can step once and be back in the caller.  */
4336
          struct symtab_and_line sr_sal;
4337
          init_sal (&sr_sal);
4338
          sr_sal.pc = ecs->stop_func_start;
4339
          sr_sal.pspace = get_frame_program_space (frame);
4340
          insert_step_resume_breakpoint_at_sal (gdbarch,
4341
                                                sr_sal, null_frame_id);
4342
        }
4343
      else
4344
        /* Set a breakpoint at callee's return address (the address
4345
           at which the caller will resume).  */
4346
        insert_step_resume_breakpoint_at_caller (frame);
4347
 
4348
      keep_going (ecs);
4349
      return;
4350
    }
4351
 
4352
  /* Reverse stepping through solib trampolines.  */
4353
 
4354
  if (execution_direction == EXEC_REVERSE
4355
      && ecs->event_thread->step_over_calls != STEP_OVER_NONE)
4356
    {
4357
      if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4358
          || (ecs->stop_func_start == 0
4359
              && in_solib_dynsym_resolve_code (stop_pc)))
4360
        {
4361
          /* Any solib trampoline code can be handled in reverse
4362
             by simply continuing to single-step.  We have already
4363
             executed the solib function (backwards), and a few
4364
             steps will take us back through the trampoline to the
4365
             caller.  */
4366
          keep_going (ecs);
4367
          return;
4368
        }
4369
      else if (in_solib_dynsym_resolve_code (stop_pc))
4370
        {
4371
          /* Stepped backward into the solib dynsym resolver.
4372
             Set a breakpoint at its start and continue, then
4373
             one more step will take us out.  */
4374
          struct symtab_and_line sr_sal;
4375
          init_sal (&sr_sal);
4376
          sr_sal.pc = ecs->stop_func_start;
4377
          sr_sal.pspace = get_frame_program_space (frame);
4378
          insert_step_resume_breakpoint_at_sal (gdbarch,
4379
                                                sr_sal, null_frame_id);
4380
          keep_going (ecs);
4381
          return;
4382
        }
4383
    }
4384
 
4385
  /* If we're in the return path from a shared library trampoline,
4386
     we want to proceed through the trampoline when stepping.  */
4387
  if (gdbarch_in_solib_return_trampoline (gdbarch,
4388
                                          stop_pc, ecs->stop_func_name))
4389
    {
4390
      /* Determine where this trampoline returns.  */
4391
      CORE_ADDR real_stop_pc;
4392
      real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4393
 
4394
      if (debug_infrun)
4395
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into solib return tramp\n");
4396
 
4397
      /* Only proceed through if we know where it's going.  */
4398
      if (real_stop_pc)
4399
        {
4400
          /* And put the step-breakpoint there and go until there. */
4401
          struct symtab_and_line sr_sal;
4402
 
4403
          init_sal (&sr_sal);   /* initialize to zeroes */
4404
          sr_sal.pc = real_stop_pc;
4405
          sr_sal.section = find_pc_overlay (sr_sal.pc);
4406
          sr_sal.pspace = get_frame_program_space (frame);
4407
 
4408
          /* Do not specify what the fp should be when we stop since
4409
             on some machines the prologue is where the new fp value
4410
             is established.  */
4411
          insert_step_resume_breakpoint_at_sal (gdbarch,
4412
                                                sr_sal, null_frame_id);
4413
 
4414
          /* Restart without fiddling with the step ranges or
4415
             other state.  */
4416
          keep_going (ecs);
4417
          return;
4418
        }
4419
    }
4420
 
4421
  stop_pc_sal = find_pc_line (stop_pc, 0);
4422
 
4423
  /* NOTE: tausq/2004-05-24: This if block used to be done before all
4424
     the trampoline processing logic, however, there are some trampolines
4425
     that have no names, so we should do trampoline handling first.  */
4426
  if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4427
      && ecs->stop_func_name == NULL
4428
      && stop_pc_sal.line == 0)
4429
    {
4430
      if (debug_infrun)
4431
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into undebuggable function\n");
4432
 
4433
      /* The inferior just stepped into, or returned to, an
4434
         undebuggable function (where there is no debugging information
4435
         and no line number corresponding to the address where the
4436
         inferior stopped).  Since we want to skip this kind of code,
4437
         we keep going until the inferior returns from this
4438
         function - unless the user has asked us not to (via
4439
         set step-mode) or we no longer know how to get back
4440
         to the call site.  */
4441
      if (step_stop_if_no_debug
4442
          || !frame_id_p (frame_unwind_caller_id (frame)))
4443
        {
4444
          /* If we have no line number and the step-stop-if-no-debug
4445
             is set, we stop the step so that the user has a chance to
4446
             switch in assembly mode.  */
4447
          ecs->event_thread->stop_step = 1;
4448
          print_stop_reason (END_STEPPING_RANGE, 0);
4449
          stop_stepping (ecs);
4450
          return;
4451
        }
4452
      else
4453
        {
4454
          /* Set a breakpoint at callee's return address (the address
4455
             at which the caller will resume).  */
4456
          insert_step_resume_breakpoint_at_caller (frame);
4457
          keep_going (ecs);
4458
          return;
4459
        }
4460
    }
4461
 
4462
  if (ecs->event_thread->step_range_end == 1)
4463
    {
4464
      /* It is stepi or nexti.  We always want to stop stepping after
4465
         one instruction.  */
4466
      if (debug_infrun)
4467
         fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
4468
      ecs->event_thread->stop_step = 1;
4469
      print_stop_reason (END_STEPPING_RANGE, 0);
4470
      stop_stepping (ecs);
4471
      return;
4472
    }
4473
 
4474
  if (stop_pc_sal.line == 0)
4475
    {
4476
      /* We have no line number information.  That means to stop
4477
         stepping (does this always happen right after one instruction,
4478
         when we do "s" in a function with no line numbers,
4479
         or can this happen as a result of a return or longjmp?).  */
4480
      if (debug_infrun)
4481
         fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
4482
      ecs->event_thread->stop_step = 1;
4483
      print_stop_reason (END_STEPPING_RANGE, 0);
4484
      stop_stepping (ecs);
4485
      return;
4486
    }
4487
 
4488
  /* Look for "calls" to inlined functions, part one.  If the inline
4489
     frame machinery detected some skipped call sites, we have entered
4490
     a new inline function.  */
4491
 
4492
  if (frame_id_eq (get_frame_id (get_current_frame ()),
4493
                   ecs->event_thread->step_frame_id)
4494
      && inline_skipped_frames (ecs->ptid))
4495
    {
4496
      struct symtab_and_line call_sal;
4497
 
4498
      if (debug_infrun)
4499
        fprintf_unfiltered (gdb_stdlog,
4500
                            "infrun: stepped into inlined function\n");
4501
 
4502
      find_frame_sal (get_current_frame (), &call_sal);
4503
 
4504
      if (ecs->event_thread->step_over_calls != STEP_OVER_ALL)
4505
        {
4506
          /* For "step", we're going to stop.  But if the call site
4507
             for this inlined function is on the same source line as
4508
             we were previously stepping, go down into the function
4509
             first.  Otherwise stop at the call site.  */
4510
 
4511
          if (call_sal.line == ecs->event_thread->current_line
4512
              && call_sal.symtab == ecs->event_thread->current_symtab)
4513
            step_into_inline_frame (ecs->ptid);
4514
 
4515
          ecs->event_thread->stop_step = 1;
4516
          print_stop_reason (END_STEPPING_RANGE, 0);
4517
          stop_stepping (ecs);
4518
          return;
4519
        }
4520
      else
4521
        {
4522
          /* For "next", we should stop at the call site if it is on a
4523
             different source line.  Otherwise continue through the
4524
             inlined function.  */
4525
          if (call_sal.line == ecs->event_thread->current_line
4526
              && call_sal.symtab == ecs->event_thread->current_symtab)
4527
            keep_going (ecs);
4528
          else
4529
            {
4530
              ecs->event_thread->stop_step = 1;
4531
              print_stop_reason (END_STEPPING_RANGE, 0);
4532
              stop_stepping (ecs);
4533
            }
4534
          return;
4535
        }
4536
    }
4537
 
4538
  /* Look for "calls" to inlined functions, part two.  If we are still
4539
     in the same real function we were stepping through, but we have
4540
     to go further up to find the exact frame ID, we are stepping
4541
     through a more inlined call beyond its call site.  */
4542
 
4543
  if (get_frame_type (get_current_frame ()) == INLINE_FRAME
4544
      && !frame_id_eq (get_frame_id (get_current_frame ()),
4545
                       ecs->event_thread->step_frame_id)
4546
      && stepped_in_from (get_current_frame (),
4547
                          ecs->event_thread->step_frame_id))
4548
    {
4549
      if (debug_infrun)
4550
        fprintf_unfiltered (gdb_stdlog,
4551
                            "infrun: stepping through inlined function\n");
4552
 
4553
      if (ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4554
        keep_going (ecs);
4555
      else
4556
        {
4557
          ecs->event_thread->stop_step = 1;
4558
          print_stop_reason (END_STEPPING_RANGE, 0);
4559
          stop_stepping (ecs);
4560
        }
4561
      return;
4562
    }
4563
 
4564
  if ((stop_pc == stop_pc_sal.pc)
4565
      && (ecs->event_thread->current_line != stop_pc_sal.line
4566
          || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
4567
    {
4568
      /* We are at the start of a different line.  So stop.  Note that
4569
         we don't stop if we step into the middle of a different line.
4570
         That is said to make things like for (;;) statements work
4571
         better.  */
4572
      if (debug_infrun)
4573
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped to a different line\n");
4574
      ecs->event_thread->stop_step = 1;
4575
      print_stop_reason (END_STEPPING_RANGE, 0);
4576
      stop_stepping (ecs);
4577
      return;
4578
    }
4579
 
4580
  /* We aren't done stepping.
4581
 
4582
     Optimize by setting the stepping range to the line.
4583
     (We might not be in the original line, but if we entered a
4584
     new line in mid-statement, we continue stepping.  This makes
4585
     things like for(;;) statements work better.)  */
4586
 
4587
  ecs->event_thread->step_range_start = stop_pc_sal.pc;
4588
  ecs->event_thread->step_range_end = stop_pc_sal.end;
4589
  set_step_info (frame, stop_pc_sal);
4590
 
4591
  if (debug_infrun)
4592
     fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
4593
  keep_going (ecs);
4594
}
4595
 
4596
/* Is thread TP in the middle of single-stepping?  */
4597
 
4598
static int
4599
currently_stepping (struct thread_info *tp)
4600
{
4601
  return ((tp->step_range_end && tp->step_resume_breakpoint == NULL)
4602
          || tp->trap_expected
4603
          || tp->stepping_through_solib_after_catch
4604
          || bpstat_should_step ());
4605
}
4606
 
4607
/* Returns true if any thread *but* the one passed in "data" is in the
4608
   middle of stepping or of handling a "next".  */
4609
 
4610
static int
4611
currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
4612
{
4613
  if (tp == data)
4614
    return 0;
4615
 
4616
  return (tp->step_range_end
4617
          || tp->trap_expected
4618
          || tp->stepping_through_solib_after_catch);
4619
}
4620
 
4621
/* Inferior has stepped into a subroutine call with source code that
4622
   we should not step over.  Do step to the first line of code in
4623
   it.  */
4624
 
4625
static void
4626
handle_step_into_function (struct gdbarch *gdbarch,
4627
                           struct execution_control_state *ecs)
4628
{
4629
  struct symtab *s;
4630
  struct symtab_and_line stop_func_sal, sr_sal;
4631
 
4632
  s = find_pc_symtab (stop_pc);
4633
  if (s && s->language != language_asm)
4634
    ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
4635
                                                  ecs->stop_func_start);
4636
 
4637
  stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
4638
  /* Use the step_resume_break to step until the end of the prologue,
4639
     even if that involves jumps (as it seems to on the vax under
4640
     4.2).  */
4641
  /* If the prologue ends in the middle of a source line, continue to
4642
     the end of that source line (if it is still within the function).
4643
     Otherwise, just go to end of prologue.  */
4644
  if (stop_func_sal.end
4645
      && stop_func_sal.pc != ecs->stop_func_start
4646
      && stop_func_sal.end < ecs->stop_func_end)
4647
    ecs->stop_func_start = stop_func_sal.end;
4648
 
4649
  /* Architectures which require breakpoint adjustment might not be able
4650
     to place a breakpoint at the computed address.  If so, the test
4651
     ``ecs->stop_func_start == stop_pc'' will never succeed.  Adjust
4652
     ecs->stop_func_start to an address at which a breakpoint may be
4653
     legitimately placed.
4654
 
4655
     Note:  kevinb/2004-01-19:  On FR-V, if this adjustment is not
4656
     made, GDB will enter an infinite loop when stepping through
4657
     optimized code consisting of VLIW instructions which contain
4658
     subinstructions corresponding to different source lines.  On
4659
     FR-V, it's not permitted to place a breakpoint on any but the
4660
     first subinstruction of a VLIW instruction.  When a breakpoint is
4661
     set, GDB will adjust the breakpoint address to the beginning of
4662
     the VLIW instruction.  Thus, we need to make the corresponding
4663
     adjustment here when computing the stop address.  */
4664
 
4665
  if (gdbarch_adjust_breakpoint_address_p (gdbarch))
4666
    {
4667
      ecs->stop_func_start
4668
        = gdbarch_adjust_breakpoint_address (gdbarch,
4669
                                             ecs->stop_func_start);
4670
    }
4671
 
4672
  if (ecs->stop_func_start == stop_pc)
4673
    {
4674
      /* We are already there: stop now.  */
4675
      ecs->event_thread->stop_step = 1;
4676
      print_stop_reason (END_STEPPING_RANGE, 0);
4677
      stop_stepping (ecs);
4678
      return;
4679
    }
4680
  else
4681
    {
4682
      /* Put the step-breakpoint there and go until there.  */
4683
      init_sal (&sr_sal);       /* initialize to zeroes */
4684
      sr_sal.pc = ecs->stop_func_start;
4685
      sr_sal.section = find_pc_overlay (ecs->stop_func_start);
4686
      sr_sal.pspace = get_frame_program_space (get_current_frame ());
4687
 
4688
      /* Do not specify what the fp should be when we stop since on
4689
         some machines the prologue is where the new fp value is
4690
         established.  */
4691
      insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
4692
 
4693
      /* And make sure stepping stops right away then.  */
4694
      ecs->event_thread->step_range_end = ecs->event_thread->step_range_start;
4695
    }
4696
  keep_going (ecs);
4697
}
4698
 
4699
/* Inferior has stepped backward into a subroutine call with source
4700
   code that we should not step over.  Do step to the beginning of the
4701
   last line of code in it.  */
4702
 
4703
static void
4704
handle_step_into_function_backward (struct gdbarch *gdbarch,
4705
                                    struct execution_control_state *ecs)
4706
{
4707
  struct symtab *s;
4708
  struct symtab_and_line stop_func_sal, sr_sal;
4709
 
4710
  s = find_pc_symtab (stop_pc);
4711
  if (s && s->language != language_asm)
4712
    ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
4713
                                                  ecs->stop_func_start);
4714
 
4715
  stop_func_sal = find_pc_line (stop_pc, 0);
4716
 
4717
  /* OK, we're just going to keep stepping here.  */
4718
  if (stop_func_sal.pc == stop_pc)
4719
    {
4720
      /* We're there already.  Just stop stepping now.  */
4721
      ecs->event_thread->stop_step = 1;
4722
      print_stop_reason (END_STEPPING_RANGE, 0);
4723
      stop_stepping (ecs);
4724
    }
4725
  else
4726
    {
4727
      /* Else just reset the step range and keep going.
4728
         No step-resume breakpoint, they don't work for
4729
         epilogues, which can have multiple entry paths.  */
4730
      ecs->event_thread->step_range_start = stop_func_sal.pc;
4731
      ecs->event_thread->step_range_end = stop_func_sal.end;
4732
      keep_going (ecs);
4733
    }
4734
  return;
4735
}
4736
 
4737
/* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
4738
   This is used to both functions and to skip over code.  */
4739
 
4740
static void
4741
insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
4742
                                      struct symtab_and_line sr_sal,
4743
                                      struct frame_id sr_id)
4744
{
4745
  /* There should never be more than one step-resume or longjmp-resume
4746
     breakpoint per thread, so we should never be setting a new
4747
     step_resume_breakpoint when one is already active.  */
4748
  gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
4749
 
4750
  if (debug_infrun)
4751
    fprintf_unfiltered (gdb_stdlog,
4752
                        "infrun: inserting step-resume breakpoint at %s\n",
4753
                        paddress (gdbarch, sr_sal.pc));
4754
 
4755
  inferior_thread ()->step_resume_breakpoint
4756
    = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, bp_step_resume);
4757
}
4758
 
4759
/* Insert a "step-resume breakpoint" at RETURN_FRAME.pc.  This is used
4760
   to skip a potential signal handler.
4761
 
4762
   This is called with the interrupted function's frame.  The signal
4763
   handler, when it returns, will resume the interrupted function at
4764
   RETURN_FRAME.pc.  */
4765
 
4766
static void
4767
insert_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
4768
{
4769
  struct symtab_and_line sr_sal;
4770
  struct gdbarch *gdbarch;
4771
 
4772
  gdb_assert (return_frame != NULL);
4773
  init_sal (&sr_sal);           /* initialize to zeros */
4774
 
4775
  gdbarch = get_frame_arch (return_frame);
4776
  sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
4777
  sr_sal.section = find_pc_overlay (sr_sal.pc);
4778
  sr_sal.pspace = get_frame_program_space (return_frame);
4779
 
4780
  insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
4781
                                        get_stack_frame_id (return_frame));
4782
}
4783
 
4784
/* Similar to insert_step_resume_breakpoint_at_frame, except
4785
   but a breakpoint at the previous frame's PC.  This is used to
4786
   skip a function after stepping into it (for "next" or if the called
4787
   function has no debugging information).
4788
 
4789
   The current function has almost always been reached by single
4790
   stepping a call or return instruction.  NEXT_FRAME belongs to the
4791
   current function, and the breakpoint will be set at the caller's
4792
   resume address.
4793
 
4794
   This is a separate function rather than reusing
4795
   insert_step_resume_breakpoint_at_frame in order to avoid
4796
   get_prev_frame, which may stop prematurely (see the implementation
4797
   of frame_unwind_caller_id for an example).  */
4798
 
4799
static void
4800
insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
4801
{
4802
  struct symtab_and_line sr_sal;
4803
  struct gdbarch *gdbarch;
4804
 
4805
  /* We shouldn't have gotten here if we don't know where the call site
4806
     is.  */
4807
  gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
4808
 
4809
  init_sal (&sr_sal);           /* initialize to zeros */
4810
 
4811
  gdbarch = frame_unwind_caller_arch (next_frame);
4812
  sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
4813
                                        frame_unwind_caller_pc (next_frame));
4814
  sr_sal.section = find_pc_overlay (sr_sal.pc);
4815
  sr_sal.pspace = frame_unwind_program_space (next_frame);
4816
 
4817
  insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
4818
                                        frame_unwind_caller_id (next_frame));
4819
}
4820
 
4821
/* Insert a "longjmp-resume" breakpoint at PC.  This is used to set a
4822
   new breakpoint at the target of a jmp_buf.  The handling of
4823
   longjmp-resume uses the same mechanisms used for handling
4824
   "step-resume" breakpoints.  */
4825
 
4826
static void
4827
insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
4828
{
4829
  /* There should never be more than one step-resume or longjmp-resume
4830
     breakpoint per thread, so we should never be setting a new
4831
     longjmp_resume_breakpoint when one is already active.  */
4832
  gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
4833
 
4834
  if (debug_infrun)
4835
    fprintf_unfiltered (gdb_stdlog,
4836
                        "infrun: inserting longjmp-resume breakpoint at %s\n",
4837
                        paddress (gdbarch, pc));
4838
 
4839
  inferior_thread ()->step_resume_breakpoint =
4840
    set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
4841
}
4842
 
4843
static void
4844
stop_stepping (struct execution_control_state *ecs)
4845
{
4846
  if (debug_infrun)
4847
    fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
4848
 
4849
  /* Let callers know we don't want to wait for the inferior anymore.  */
4850
  ecs->wait_some_more = 0;
4851
}
4852
 
4853
/* This function handles various cases where we need to continue
4854
   waiting for the inferior.  */
4855
/* (Used to be the keep_going: label in the old wait_for_inferior) */
4856
 
4857
static void
4858
keep_going (struct execution_control_state *ecs)
4859
{
4860
  /* Make sure normal_stop is called if we get a QUIT handled before
4861
     reaching resume.  */
4862
  struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
4863
 
4864
  /* Save the pc before execution, to compare with pc after stop.  */
4865
  ecs->event_thread->prev_pc
4866
    = regcache_read_pc (get_thread_regcache (ecs->ptid));
4867
 
4868
  /* If we did not do break;, it means we should keep running the
4869
     inferior and not return to debugger.  */
4870
 
4871
  if (ecs->event_thread->trap_expected
4872
      && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP)
4873
    {
4874
      /* We took a signal (which we are supposed to pass through to
4875
         the inferior, else we'd not get here) and we haven't yet
4876
         gotten our trap.  Simply continue.  */
4877
 
4878
      discard_cleanups (old_cleanups);
4879
      resume (currently_stepping (ecs->event_thread),
4880
              ecs->event_thread->stop_signal);
4881
    }
4882
  else
4883
    {
4884
      /* Either the trap was not expected, but we are continuing
4885
         anyway (the user asked that this signal be passed to the
4886
         child)
4887
         -- or --
4888
         The signal was SIGTRAP, e.g. it was our signal, but we
4889
         decided we should resume from it.
4890
 
4891
         We're going to run this baby now!
4892
 
4893
         Note that insert_breakpoints won't try to re-insert
4894
         already inserted breakpoints.  Therefore, we don't
4895
         care if breakpoints were already inserted, or not.  */
4896
 
4897
      if (ecs->event_thread->stepping_over_breakpoint)
4898
        {
4899
          struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
4900
          if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
4901
            /* Since we can't do a displaced step, we have to remove
4902
               the breakpoint while we step it.  To keep things
4903
               simple, we remove them all.  */
4904
            remove_breakpoints ();
4905
        }
4906
      else
4907
        {
4908
          struct gdb_exception e;
4909
          /* Stop stepping when inserting breakpoints
4910
             has failed.  */
4911
          TRY_CATCH (e, RETURN_MASK_ERROR)
4912
            {
4913
              insert_breakpoints ();
4914
            }
4915
          if (e.reason < 0)
4916
            {
4917
              exception_print (gdb_stderr, e);
4918
              stop_stepping (ecs);
4919
              return;
4920
            }
4921
        }
4922
 
4923
      ecs->event_thread->trap_expected = ecs->event_thread->stepping_over_breakpoint;
4924
 
4925
      /* Do not deliver SIGNAL_TRAP (except when the user explicitly
4926
         specifies that such a signal should be delivered to the
4927
         target program).
4928
 
4929
         Typically, this would occure when a user is debugging a
4930
         target monitor on a simulator: the target monitor sets a
4931
         breakpoint; the simulator encounters this break-point and
4932
         halts the simulation handing control to GDB; GDB, noteing
4933
         that the break-point isn't valid, returns control back to the
4934
         simulator; the simulator then delivers the hardware
4935
         equivalent of a SIGNAL_TRAP to the program being debugged. */
4936
 
4937
      if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
4938
          && !signal_program[ecs->event_thread->stop_signal])
4939
        ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
4940
 
4941
      discard_cleanups (old_cleanups);
4942
      resume (currently_stepping (ecs->event_thread),
4943
              ecs->event_thread->stop_signal);
4944
    }
4945
 
4946
  prepare_to_wait (ecs);
4947
}
4948
 
4949
/* This function normally comes after a resume, before
4950
   handle_inferior_event exits.  It takes care of any last bits of
4951
   housekeeping, and sets the all-important wait_some_more flag.  */
4952
 
4953
static void
4954
prepare_to_wait (struct execution_control_state *ecs)
4955
{
4956
  if (debug_infrun)
4957
    fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
4958
 
4959
  /* This is the old end of the while loop.  Let everybody know we
4960
     want to wait for the inferior some more and get called again
4961
     soon.  */
4962
  ecs->wait_some_more = 1;
4963
}
4964
 
4965
/* Print why the inferior has stopped. We always print something when
4966
   the inferior exits, or receives a signal. The rest of the cases are
4967
   dealt with later on in normal_stop() and print_it_typical().  Ideally
4968
   there should be a call to this function from handle_inferior_event()
4969
   each time stop_stepping() is called.*/
4970
static void
4971
print_stop_reason (enum inferior_stop_reason stop_reason, int stop_info)
4972
{
4973
  switch (stop_reason)
4974
    {
4975
    case END_STEPPING_RANGE:
4976
      /* We are done with a step/next/si/ni command. */
4977
      /* For now print nothing. */
4978
      /* Print a message only if not in the middle of doing a "step n"
4979
         operation for n > 1 */
4980
      if (!inferior_thread ()->step_multi
4981
          || !inferior_thread ()->stop_step)
4982
        if (ui_out_is_mi_like_p (uiout))
4983
          ui_out_field_string
4984
            (uiout, "reason",
4985
             async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
4986
      break;
4987
    case SIGNAL_EXITED:
4988
      /* The inferior was terminated by a signal. */
4989
      annotate_signalled ();
4990
      if (ui_out_is_mi_like_p (uiout))
4991
        ui_out_field_string
4992
          (uiout, "reason",
4993
           async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
4994
      ui_out_text (uiout, "\nProgram terminated with signal ");
4995
      annotate_signal_name ();
4996
      ui_out_field_string (uiout, "signal-name",
4997
                           target_signal_to_name (stop_info));
4998
      annotate_signal_name_end ();
4999
      ui_out_text (uiout, ", ");
5000
      annotate_signal_string ();
5001
      ui_out_field_string (uiout, "signal-meaning",
5002
                           target_signal_to_string (stop_info));
5003
      annotate_signal_string_end ();
5004
      ui_out_text (uiout, ".\n");
5005
      ui_out_text (uiout, "The program no longer exists.\n");
5006
      break;
5007
    case EXITED:
5008
      /* The inferior program is finished. */
5009
      annotate_exited (stop_info);
5010
      if (stop_info)
5011
        {
5012
          if (ui_out_is_mi_like_p (uiout))
5013
            ui_out_field_string (uiout, "reason",
5014
                                 async_reason_lookup (EXEC_ASYNC_EXITED));
5015
          ui_out_text (uiout, "\nProgram exited with code ");
5016
          ui_out_field_fmt (uiout, "exit-code", "0%o",
5017
                            (unsigned int) stop_info);
5018
          ui_out_text (uiout, ".\n");
5019
        }
5020
      else
5021
        {
5022
          if (ui_out_is_mi_like_p (uiout))
5023
            ui_out_field_string
5024
              (uiout, "reason",
5025
               async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5026
          ui_out_text (uiout, "\nProgram exited normally.\n");
5027
        }
5028
      /* Support the --return-child-result option.  */
5029
      return_child_result_value = stop_info;
5030
      break;
5031
    case SIGNAL_RECEIVED:
5032
      /* Signal received.  The signal table tells us to print about
5033
         it. */
5034
      annotate_signal ();
5035
 
5036
      if (stop_info == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5037
        {
5038
          struct thread_info *t = inferior_thread ();
5039
 
5040
          ui_out_text (uiout, "\n[");
5041
          ui_out_field_string (uiout, "thread-name",
5042
                               target_pid_to_str (t->ptid));
5043
          ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5044
          ui_out_text (uiout, " stopped");
5045
        }
5046
      else
5047
        {
5048
          ui_out_text (uiout, "\nProgram received signal ");
5049
          annotate_signal_name ();
5050
          if (ui_out_is_mi_like_p (uiout))
5051
            ui_out_field_string
5052
              (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5053
          ui_out_field_string (uiout, "signal-name",
5054
                               target_signal_to_name (stop_info));
5055
          annotate_signal_name_end ();
5056
          ui_out_text (uiout, ", ");
5057
          annotate_signal_string ();
5058
          ui_out_field_string (uiout, "signal-meaning",
5059
                               target_signal_to_string (stop_info));
5060
          annotate_signal_string_end ();
5061
        }
5062
      ui_out_text (uiout, ".\n");
5063
      break;
5064
    case NO_HISTORY:
5065
      /* Reverse execution: target ran out of history info.  */
5066
      ui_out_text (uiout, "\nNo more reverse-execution history.\n");
5067
      break;
5068
    default:
5069
      internal_error (__FILE__, __LINE__,
5070
                      _("print_stop_reason: unrecognized enum value"));
5071
      break;
5072
    }
5073
}
5074
 
5075
 
5076
/* Here to return control to GDB when the inferior stops for real.
5077
   Print appropriate messages, remove breakpoints, give terminal our modes.
5078
 
5079
   STOP_PRINT_FRAME nonzero means print the executing frame
5080
   (pc, function, args, file, line number and line text).
5081
   BREAKPOINTS_FAILED nonzero means stop was due to error
5082
   attempting to insert breakpoints.  */
5083
 
5084
void
5085
normal_stop (void)
5086
{
5087
  struct target_waitstatus last;
5088
  ptid_t last_ptid;
5089
  struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5090
 
5091
  get_last_target_status (&last_ptid, &last);
5092
 
5093
  /* If an exception is thrown from this point on, make sure to
5094
     propagate GDB's knowledge of the executing state to the
5095
     frontend/user running state.  A QUIT is an easy exception to see
5096
     here, so do this before any filtered output.  */
5097
  if (!non_stop)
5098
    make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5099
  else if (last.kind != TARGET_WAITKIND_SIGNALLED
5100
           && last.kind != TARGET_WAITKIND_EXITED)
5101
    make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5102
 
5103
  /* In non-stop mode, we don't want GDB to switch threads behind the
5104
     user's back, to avoid races where the user is typing a command to
5105
     apply to thread x, but GDB switches to thread y before the user
5106
     finishes entering the command.  */
5107
 
5108
  /* As with the notification of thread events, we want to delay
5109
     notifying the user that we've switched thread context until
5110
     the inferior actually stops.
5111
 
5112
     There's no point in saying anything if the inferior has exited.
5113
     Note that SIGNALLED here means "exited with a signal", not
5114
     "received a signal".  */
5115
  if (!non_stop
5116
      && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5117
      && target_has_execution
5118
      && last.kind != TARGET_WAITKIND_SIGNALLED
5119
      && last.kind != TARGET_WAITKIND_EXITED)
5120
    {
5121
      target_terminal_ours_for_output ();
5122
      printf_filtered (_("[Switching to %s]\n"),
5123
                       target_pid_to_str (inferior_ptid));
5124
      annotate_thread_changed ();
5125
      previous_inferior_ptid = inferior_ptid;
5126
    }
5127
 
5128
  if (!breakpoints_always_inserted_mode () && target_has_execution)
5129
    {
5130
      if (remove_breakpoints ())
5131
        {
5132
          target_terminal_ours_for_output ();
5133
          printf_filtered (_("\
5134
Cannot remove breakpoints because program is no longer writable.\n\
5135
Further execution is probably impossible.\n"));
5136
        }
5137
    }
5138
 
5139
  /* If an auto-display called a function and that got a signal,
5140
     delete that auto-display to avoid an infinite recursion.  */
5141
 
5142
  if (stopped_by_random_signal)
5143
    disable_current_display ();
5144
 
5145
  /* Don't print a message if in the middle of doing a "step n"
5146
     operation for n > 1 */
5147
  if (target_has_execution
5148
      && last.kind != TARGET_WAITKIND_SIGNALLED
5149
      && last.kind != TARGET_WAITKIND_EXITED
5150
      && inferior_thread ()->step_multi
5151
      && inferior_thread ()->stop_step)
5152
    goto done;
5153
 
5154
  target_terminal_ours ();
5155
 
5156
  /* Set the current source location.  This will also happen if we
5157
     display the frame below, but the current SAL will be incorrect
5158
     during a user hook-stop function.  */
5159
  if (has_stack_frames () && !stop_stack_dummy)
5160
    set_current_sal_from_frame (get_current_frame (), 1);
5161
 
5162
  /* Let the user/frontend see the threads as stopped.  */
5163
  do_cleanups (old_chain);
5164
 
5165
  /* Look up the hook_stop and run it (CLI internally handles problem
5166
     of stop_command's pre-hook not existing).  */
5167
  if (stop_command)
5168
    catch_errors (hook_stop_stub, stop_command,
5169
                  "Error while running hook_stop:\n", RETURN_MASK_ALL);
5170
 
5171
  if (!has_stack_frames ())
5172
    goto done;
5173
 
5174
  if (last.kind == TARGET_WAITKIND_SIGNALLED
5175
      || last.kind == TARGET_WAITKIND_EXITED)
5176
    goto done;
5177
 
5178
  /* Select innermost stack frame - i.e., current frame is frame 0,
5179
     and current location is based on that.
5180
     Don't do this on return from a stack dummy routine,
5181
     or if the program has exited. */
5182
 
5183
  if (!stop_stack_dummy)
5184
    {
5185
      select_frame (get_current_frame ());
5186
 
5187
      /* Print current location without a level number, if
5188
         we have changed functions or hit a breakpoint.
5189
         Print source line if we have one.
5190
         bpstat_print() contains the logic deciding in detail
5191
         what to print, based on the event(s) that just occurred. */
5192
 
5193
      /* If --batch-silent is enabled then there's no need to print the current
5194
         source location, and to try risks causing an error message about
5195
         missing source files.  */
5196
      if (stop_print_frame && !batch_silent)
5197
        {
5198
          int bpstat_ret;
5199
          int source_flag;
5200
          int do_frame_printing = 1;
5201
          struct thread_info *tp = inferior_thread ();
5202
 
5203
          bpstat_ret = bpstat_print (tp->stop_bpstat);
5204
          switch (bpstat_ret)
5205
            {
5206
            case PRINT_UNKNOWN:
5207
              /* If we had hit a shared library event breakpoint,
5208
                 bpstat_print would print out this message.  If we hit
5209
                 an OS-level shared library event, do the same
5210
                 thing.  */
5211
              if (last.kind == TARGET_WAITKIND_LOADED)
5212
                {
5213
                  printf_filtered (_("Stopped due to shared library event\n"));
5214
                  source_flag = SRC_LINE;       /* something bogus */
5215
                  do_frame_printing = 0;
5216
                  break;
5217
                }
5218
 
5219
              /* FIXME: cagney/2002-12-01: Given that a frame ID does
5220
                 (or should) carry around the function and does (or
5221
                 should) use that when doing a frame comparison.  */
5222
              if (tp->stop_step
5223
                  && frame_id_eq (tp->step_frame_id,
5224
                                  get_frame_id (get_current_frame ()))
5225
                  && step_start_function == find_pc_function (stop_pc))
5226
                source_flag = SRC_LINE; /* finished step, just print source line */
5227
              else
5228
                source_flag = SRC_AND_LOC;      /* print location and source line */
5229
              break;
5230
            case PRINT_SRC_AND_LOC:
5231
              source_flag = SRC_AND_LOC;        /* print location and source line */
5232
              break;
5233
            case PRINT_SRC_ONLY:
5234
              source_flag = SRC_LINE;
5235
              break;
5236
            case PRINT_NOTHING:
5237
              source_flag = SRC_LINE;   /* something bogus */
5238
              do_frame_printing = 0;
5239
              break;
5240
            default:
5241
              internal_error (__FILE__, __LINE__, _("Unknown value."));
5242
            }
5243
 
5244
          /* The behavior of this routine with respect to the source
5245
             flag is:
5246
             SRC_LINE: Print only source line
5247
             LOCATION: Print only location
5248
             SRC_AND_LOC: Print location and source line */
5249
          if (do_frame_printing)
5250
            print_stack_frame (get_selected_frame (NULL), 0, source_flag);
5251
 
5252
          /* Display the auto-display expressions.  */
5253
          do_displays ();
5254
        }
5255
    }
5256
 
5257
  /* Save the function value return registers, if we care.
5258
     We might be about to restore their previous contents.  */
5259
  if (inferior_thread ()->proceed_to_finish)
5260
    {
5261
      /* This should not be necessary.  */
5262
      if (stop_registers)
5263
        regcache_xfree (stop_registers);
5264
 
5265
      /* NB: The copy goes through to the target picking up the value of
5266
         all the registers.  */
5267
      stop_registers = regcache_dup (get_current_regcache ());
5268
    }
5269
 
5270
  if (stop_stack_dummy)
5271
    {
5272
      /* Pop the empty frame that contains the stack dummy.
5273
         This also restores inferior state prior to the call
5274
         (struct inferior_thread_state).  */
5275
      struct frame_info *frame = get_current_frame ();
5276
      gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
5277
      frame_pop (frame);
5278
      /* frame_pop() calls reinit_frame_cache as the last thing it does
5279
         which means there's currently no selected frame.  We don't need
5280
         to re-establish a selected frame if the dummy call returns normally,
5281
         that will be done by restore_inferior_status.  However, we do have
5282
         to handle the case where the dummy call is returning after being
5283
         stopped (e.g. the dummy call previously hit a breakpoint).  We
5284
         can't know which case we have so just always re-establish a
5285
         selected frame here.  */
5286
      select_frame (get_current_frame ());
5287
    }
5288
 
5289
done:
5290
  annotate_stopped ();
5291
 
5292
  /* Suppress the stop observer if we're in the middle of:
5293
 
5294
     - a step n (n > 1), as there still more steps to be done.
5295
 
5296
     - a "finish" command, as the observer will be called in
5297
       finish_command_continuation, so it can include the inferior
5298
       function's return value.
5299
 
5300
     - calling an inferior function, as we pretend we inferior didn't
5301
       run at all.  The return value of the call is handled by the
5302
       expression evaluator, through call_function_by_hand.  */
5303
 
5304
  if (!target_has_execution
5305
      || last.kind == TARGET_WAITKIND_SIGNALLED
5306
      || last.kind == TARGET_WAITKIND_EXITED
5307
      || (!inferior_thread ()->step_multi
5308
          && !(inferior_thread ()->stop_bpstat
5309
               && inferior_thread ()->proceed_to_finish)
5310
          && !inferior_thread ()->in_infcall))
5311
    {
5312
      if (!ptid_equal (inferior_ptid, null_ptid))
5313
        observer_notify_normal_stop (inferior_thread ()->stop_bpstat,
5314
                                     stop_print_frame);
5315
      else
5316
        observer_notify_normal_stop (NULL, stop_print_frame);
5317
    }
5318
 
5319
  if (target_has_execution)
5320
    {
5321
      if (last.kind != TARGET_WAITKIND_SIGNALLED
5322
          && last.kind != TARGET_WAITKIND_EXITED)
5323
        /* Delete the breakpoint we stopped at, if it wants to be deleted.
5324
           Delete any breakpoint that is to be deleted at the next stop.  */
5325
        breakpoint_auto_delete (inferior_thread ()->stop_bpstat);
5326
    }
5327
 
5328
  /* Try to get rid of automatically added inferiors that are no
5329
     longer needed.  Keeping those around slows down things linearly.
5330
     Note that this never removes the current inferior.  */
5331
  prune_inferiors ();
5332
}
5333
 
5334
static int
5335
hook_stop_stub (void *cmd)
5336
{
5337
  execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
5338
  return (0);
5339
}
5340
 
5341
int
5342
signal_stop_state (int signo)
5343
{
5344
  return signal_stop[signo];
5345
}
5346
 
5347
int
5348
signal_print_state (int signo)
5349
{
5350
  return signal_print[signo];
5351
}
5352
 
5353
int
5354
signal_pass_state (int signo)
5355
{
5356
  return signal_program[signo];
5357
}
5358
 
5359
int
5360
signal_stop_update (int signo, int state)
5361
{
5362
  int ret = signal_stop[signo];
5363
  signal_stop[signo] = state;
5364
  return ret;
5365
}
5366
 
5367
int
5368
signal_print_update (int signo, int state)
5369
{
5370
  int ret = signal_print[signo];
5371
  signal_print[signo] = state;
5372
  return ret;
5373
}
5374
 
5375
int
5376
signal_pass_update (int signo, int state)
5377
{
5378
  int ret = signal_program[signo];
5379
  signal_program[signo] = state;
5380
  return ret;
5381
}
5382
 
5383
static void
5384
sig_print_header (void)
5385
{
5386
  printf_filtered (_("\
5387
Signal        Stop\tPrint\tPass to program\tDescription\n"));
5388
}
5389
 
5390
static void
5391
sig_print_info (enum target_signal oursig)
5392
{
5393
  const char *name = target_signal_to_name (oursig);
5394
  int name_padding = 13 - strlen (name);
5395
 
5396
  if (name_padding <= 0)
5397
    name_padding = 0;
5398
 
5399
  printf_filtered ("%s", name);
5400
  printf_filtered ("%*.*s ", name_padding, name_padding, "                 ");
5401
  printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
5402
  printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
5403
  printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
5404
  printf_filtered ("%s\n", target_signal_to_string (oursig));
5405
}
5406
 
5407
/* Specify how various signals in the inferior should be handled.  */
5408
 
5409
static void
5410
handle_command (char *args, int from_tty)
5411
{
5412
  char **argv;
5413
  int digits, wordlen;
5414
  int sigfirst, signum, siglast;
5415
  enum target_signal oursig;
5416
  int allsigs;
5417
  int nsigs;
5418
  unsigned char *sigs;
5419
  struct cleanup *old_chain;
5420
 
5421
  if (args == NULL)
5422
    {
5423
      error_no_arg (_("signal to handle"));
5424
    }
5425
 
5426
  /* Allocate and zero an array of flags for which signals to handle. */
5427
 
5428
  nsigs = (int) TARGET_SIGNAL_LAST;
5429
  sigs = (unsigned char *) alloca (nsigs);
5430
  memset (sigs, 0, nsigs);
5431
 
5432
  /* Break the command line up into args. */
5433
 
5434
  argv = gdb_buildargv (args);
5435
  old_chain = make_cleanup_freeargv (argv);
5436
 
5437
  /* Walk through the args, looking for signal oursigs, signal names, and
5438
     actions.  Signal numbers and signal names may be interspersed with
5439
     actions, with the actions being performed for all signals cumulatively
5440
     specified.  Signal ranges can be specified as <LOW>-<HIGH>. */
5441
 
5442
  while (*argv != NULL)
5443
    {
5444
      wordlen = strlen (*argv);
5445
      for (digits = 0; isdigit ((*argv)[digits]); digits++)
5446
        {;
5447
        }
5448
      allsigs = 0;
5449
      sigfirst = siglast = -1;
5450
 
5451
      if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
5452
        {
5453
          /* Apply action to all signals except those used by the
5454
             debugger.  Silently skip those. */
5455
          allsigs = 1;
5456
          sigfirst = 0;
5457
          siglast = nsigs - 1;
5458
        }
5459
      else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
5460
        {
5461
          SET_SIGS (nsigs, sigs, signal_stop);
5462
          SET_SIGS (nsigs, sigs, signal_print);
5463
        }
5464
      else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
5465
        {
5466
          UNSET_SIGS (nsigs, sigs, signal_program);
5467
        }
5468
      else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
5469
        {
5470
          SET_SIGS (nsigs, sigs, signal_print);
5471
        }
5472
      else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
5473
        {
5474
          SET_SIGS (nsigs, sigs, signal_program);
5475
        }
5476
      else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
5477
        {
5478
          UNSET_SIGS (nsigs, sigs, signal_stop);
5479
        }
5480
      else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
5481
        {
5482
          SET_SIGS (nsigs, sigs, signal_program);
5483
        }
5484
      else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
5485
        {
5486
          UNSET_SIGS (nsigs, sigs, signal_print);
5487
          UNSET_SIGS (nsigs, sigs, signal_stop);
5488
        }
5489
      else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
5490
        {
5491
          UNSET_SIGS (nsigs, sigs, signal_program);
5492
        }
5493
      else if (digits > 0)
5494
        {
5495
          /* It is numeric.  The numeric signal refers to our own
5496
             internal signal numbering from target.h, not to host/target
5497
             signal  number.  This is a feature; users really should be
5498
             using symbolic names anyway, and the common ones like
5499
             SIGHUP, SIGINT, SIGALRM, etc. will work right anyway.  */
5500
 
5501
          sigfirst = siglast = (int)
5502
            target_signal_from_command (atoi (*argv));
5503
          if ((*argv)[digits] == '-')
5504
            {
5505
              siglast = (int)
5506
                target_signal_from_command (atoi ((*argv) + digits + 1));
5507
            }
5508
          if (sigfirst > siglast)
5509
            {
5510
              /* Bet he didn't figure we'd think of this case... */
5511
              signum = sigfirst;
5512
              sigfirst = siglast;
5513
              siglast = signum;
5514
            }
5515
        }
5516
      else
5517
        {
5518
          oursig = target_signal_from_name (*argv);
5519
          if (oursig != TARGET_SIGNAL_UNKNOWN)
5520
            {
5521
              sigfirst = siglast = (int) oursig;
5522
            }
5523
          else
5524
            {
5525
              /* Not a number and not a recognized flag word => complain.  */
5526
              error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
5527
            }
5528
        }
5529
 
5530
      /* If any signal numbers or symbol names were found, set flags for
5531
         which signals to apply actions to. */
5532
 
5533
      for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
5534
        {
5535
          switch ((enum target_signal) signum)
5536
            {
5537
            case TARGET_SIGNAL_TRAP:
5538
            case TARGET_SIGNAL_INT:
5539
              if (!allsigs && !sigs[signum])
5540
                {
5541
                  if (query (_("%s is used by the debugger.\n\
5542
Are you sure you want to change it? "), target_signal_to_name ((enum target_signal) signum)))
5543
                    {
5544
                      sigs[signum] = 1;
5545
                    }
5546
                  else
5547
                    {
5548
                      printf_unfiltered (_("Not confirmed, unchanged.\n"));
5549
                      gdb_flush (gdb_stdout);
5550
                    }
5551
                }
5552
              break;
5553
            case TARGET_SIGNAL_0:
5554
            case TARGET_SIGNAL_DEFAULT:
5555
            case TARGET_SIGNAL_UNKNOWN:
5556
              /* Make sure that "all" doesn't print these.  */
5557
              break;
5558
            default:
5559
              sigs[signum] = 1;
5560
              break;
5561
            }
5562
        }
5563
 
5564
      argv++;
5565
    }
5566
 
5567
  for (signum = 0; signum < nsigs; signum++)
5568
    if (sigs[signum])
5569
      {
5570
        target_notice_signals (inferior_ptid);
5571
 
5572
        if (from_tty)
5573
          {
5574
            /* Show the results.  */
5575
            sig_print_header ();
5576
            for (; signum < nsigs; signum++)
5577
              if (sigs[signum])
5578
                sig_print_info (signum);
5579
          }
5580
 
5581
        break;
5582
      }
5583
 
5584
  do_cleanups (old_chain);
5585
}
5586
 
5587
static void
5588
xdb_handle_command (char *args, int from_tty)
5589
{
5590
  char **argv;
5591
  struct cleanup *old_chain;
5592
 
5593
  if (args == NULL)
5594
    error_no_arg (_("xdb command"));
5595
 
5596
  /* Break the command line up into args. */
5597
 
5598
  argv = gdb_buildargv (args);
5599
  old_chain = make_cleanup_freeargv (argv);
5600
  if (argv[1] != (char *) NULL)
5601
    {
5602
      char *argBuf;
5603
      int bufLen;
5604
 
5605
      bufLen = strlen (argv[0]) + 20;
5606
      argBuf = (char *) xmalloc (bufLen);
5607
      if (argBuf)
5608
        {
5609
          int validFlag = 1;
5610
          enum target_signal oursig;
5611
 
5612
          oursig = target_signal_from_name (argv[0]);
5613
          memset (argBuf, 0, bufLen);
5614
          if (strcmp (argv[1], "Q") == 0)
5615
            sprintf (argBuf, "%s %s", argv[0], "noprint");
5616
          else
5617
            {
5618
              if (strcmp (argv[1], "s") == 0)
5619
                {
5620
                  if (!signal_stop[oursig])
5621
                    sprintf (argBuf, "%s %s", argv[0], "stop");
5622
                  else
5623
                    sprintf (argBuf, "%s %s", argv[0], "nostop");
5624
                }
5625
              else if (strcmp (argv[1], "i") == 0)
5626
                {
5627
                  if (!signal_program[oursig])
5628
                    sprintf (argBuf, "%s %s", argv[0], "pass");
5629
                  else
5630
                    sprintf (argBuf, "%s %s", argv[0], "nopass");
5631
                }
5632
              else if (strcmp (argv[1], "r") == 0)
5633
                {
5634
                  if (!signal_print[oursig])
5635
                    sprintf (argBuf, "%s %s", argv[0], "print");
5636
                  else
5637
                    sprintf (argBuf, "%s %s", argv[0], "noprint");
5638
                }
5639
              else
5640
                validFlag = 0;
5641
            }
5642
          if (validFlag)
5643
            handle_command (argBuf, from_tty);
5644
          else
5645
            printf_filtered (_("Invalid signal handling flag.\n"));
5646
          if (argBuf)
5647
            xfree (argBuf);
5648
        }
5649
    }
5650
  do_cleanups (old_chain);
5651
}
5652
 
5653
/* Print current contents of the tables set by the handle command.
5654
   It is possible we should just be printing signals actually used
5655
   by the current target (but for things to work right when switching
5656
   targets, all signals should be in the signal tables).  */
5657
 
5658
static void
5659
signals_info (char *signum_exp, int from_tty)
5660
{
5661
  enum target_signal oursig;
5662
  sig_print_header ();
5663
 
5664
  if (signum_exp)
5665
    {
5666
      /* First see if this is a symbol name.  */
5667
      oursig = target_signal_from_name (signum_exp);
5668
      if (oursig == TARGET_SIGNAL_UNKNOWN)
5669
        {
5670
          /* No, try numeric.  */
5671
          oursig =
5672
            target_signal_from_command (parse_and_eval_long (signum_exp));
5673
        }
5674
      sig_print_info (oursig);
5675
      return;
5676
    }
5677
 
5678
  printf_filtered ("\n");
5679
  /* These ugly casts brought to you by the native VAX compiler.  */
5680
  for (oursig = TARGET_SIGNAL_FIRST;
5681
       (int) oursig < (int) TARGET_SIGNAL_LAST;
5682
       oursig = (enum target_signal) ((int) oursig + 1))
5683
    {
5684
      QUIT;
5685
 
5686
      if (oursig != TARGET_SIGNAL_UNKNOWN
5687
          && oursig != TARGET_SIGNAL_DEFAULT && oursig != TARGET_SIGNAL_0)
5688
        sig_print_info (oursig);
5689
    }
5690
 
5691
  printf_filtered (_("\nUse the \"handle\" command to change these tables.\n"));
5692
}
5693
 
5694
/* The $_siginfo convenience variable is a bit special.  We don't know
5695
   for sure the type of the value until we actually have a chance to
5696
   fetch the data.  The type can change depending on gdbarch, so it it
5697
   also dependent on which thread you have selected.
5698
 
5699
     1. making $_siginfo be an internalvar that creates a new value on
5700
     access.
5701
 
5702
     2. making the value of $_siginfo be an lval_computed value.  */
5703
 
5704
/* This function implements the lval_computed support for reading a
5705
   $_siginfo value.  */
5706
 
5707
static void
5708
siginfo_value_read (struct value *v)
5709
{
5710
  LONGEST transferred;
5711
 
5712
  transferred =
5713
    target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO,
5714
                 NULL,
5715
                 value_contents_all_raw (v),
5716
                 value_offset (v),
5717
                 TYPE_LENGTH (value_type (v)));
5718
 
5719
  if (transferred != TYPE_LENGTH (value_type (v)))
5720
    error (_("Unable to read siginfo"));
5721
}
5722
 
5723
/* This function implements the lval_computed support for writing a
5724
   $_siginfo value.  */
5725
 
5726
static void
5727
siginfo_value_write (struct value *v, struct value *fromval)
5728
{
5729
  LONGEST transferred;
5730
 
5731
  transferred = target_write (&current_target,
5732
                              TARGET_OBJECT_SIGNAL_INFO,
5733
                              NULL,
5734
                              value_contents_all_raw (fromval),
5735
                              value_offset (v),
5736
                              TYPE_LENGTH (value_type (fromval)));
5737
 
5738
  if (transferred != TYPE_LENGTH (value_type (fromval)))
5739
    error (_("Unable to write siginfo"));
5740
}
5741
 
5742
static struct lval_funcs siginfo_value_funcs =
5743
  {
5744
    siginfo_value_read,
5745
    siginfo_value_write
5746
  };
5747
 
5748
/* Return a new value with the correct type for the siginfo object of
5749
   the current thread using architecture GDBARCH.  Return a void value
5750
   if there's no object available.  */
5751
 
5752
static struct value *
5753
siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var)
5754
{
5755
  if (target_has_stack
5756
      && !ptid_equal (inferior_ptid, null_ptid)
5757
      && gdbarch_get_siginfo_type_p (gdbarch))
5758
    {
5759
      struct type *type = gdbarch_get_siginfo_type (gdbarch);
5760
      return allocate_computed_value (type, &siginfo_value_funcs, NULL);
5761
    }
5762
 
5763
  return allocate_value (builtin_type (gdbarch)->builtin_void);
5764
}
5765
 
5766
 
5767
/* Inferior thread state.
5768
   These are details related to the inferior itself, and don't include
5769
   things like what frame the user had selected or what gdb was doing
5770
   with the target at the time.
5771
   For inferior function calls these are things we want to restore
5772
   regardless of whether the function call successfully completes
5773
   or the dummy frame has to be manually popped.  */
5774
 
5775
struct inferior_thread_state
5776
{
5777
  enum target_signal stop_signal;
5778
  CORE_ADDR stop_pc;
5779
  struct regcache *registers;
5780
};
5781
 
5782
struct inferior_thread_state *
5783
save_inferior_thread_state (void)
5784
{
5785
  struct inferior_thread_state *inf_state = XMALLOC (struct inferior_thread_state);
5786
  struct thread_info *tp = inferior_thread ();
5787
 
5788
  inf_state->stop_signal = tp->stop_signal;
5789
  inf_state->stop_pc = stop_pc;
5790
 
5791
  inf_state->registers = regcache_dup (get_current_regcache ());
5792
 
5793
  return inf_state;
5794
}
5795
 
5796
/* Restore inferior session state to INF_STATE.  */
5797
 
5798
void
5799
restore_inferior_thread_state (struct inferior_thread_state *inf_state)
5800
{
5801
  struct thread_info *tp = inferior_thread ();
5802
 
5803
  tp->stop_signal = inf_state->stop_signal;
5804
  stop_pc = inf_state->stop_pc;
5805
 
5806
  /* The inferior can be gone if the user types "print exit(0)"
5807
     (and perhaps other times).  */
5808
  if (target_has_execution)
5809
    /* NB: The register write goes through to the target.  */
5810
    regcache_cpy (get_current_regcache (), inf_state->registers);
5811
  regcache_xfree (inf_state->registers);
5812
  xfree (inf_state);
5813
}
5814
 
5815
static void
5816
do_restore_inferior_thread_state_cleanup (void *state)
5817
{
5818
  restore_inferior_thread_state (state);
5819
}
5820
 
5821
struct cleanup *
5822
make_cleanup_restore_inferior_thread_state (struct inferior_thread_state *inf_state)
5823
{
5824
  return make_cleanup (do_restore_inferior_thread_state_cleanup, inf_state);
5825
}
5826
 
5827
void
5828
discard_inferior_thread_state (struct inferior_thread_state *inf_state)
5829
{
5830
  regcache_xfree (inf_state->registers);
5831
  xfree (inf_state);
5832
}
5833
 
5834
struct regcache *
5835
get_inferior_thread_state_regcache (struct inferior_thread_state *inf_state)
5836
{
5837
  return inf_state->registers;
5838
}
5839
 
5840
/* Session related state for inferior function calls.
5841
   These are the additional bits of state that need to be restored
5842
   when an inferior function call successfully completes.  */
5843
 
5844
struct inferior_status
5845
{
5846
  bpstat stop_bpstat;
5847
  int stop_step;
5848
  int stop_stack_dummy;
5849
  int stopped_by_random_signal;
5850
  int stepping_over_breakpoint;
5851
  CORE_ADDR step_range_start;
5852
  CORE_ADDR step_range_end;
5853
  struct frame_id step_frame_id;
5854
  struct frame_id step_stack_frame_id;
5855
  enum step_over_calls_kind step_over_calls;
5856
  CORE_ADDR step_resume_break_address;
5857
  int stop_after_trap;
5858
  int stop_soon;
5859
 
5860
  /* ID if the selected frame when the inferior function call was made.  */
5861
  struct frame_id selected_frame_id;
5862
 
5863
  int proceed_to_finish;
5864
  int in_infcall;
5865
};
5866
 
5867
/* Save all of the information associated with the inferior<==>gdb
5868
   connection.  */
5869
 
5870
struct inferior_status *
5871
save_inferior_status (void)
5872
{
5873
  struct inferior_status *inf_status = XMALLOC (struct inferior_status);
5874
  struct thread_info *tp = inferior_thread ();
5875
  struct inferior *inf = current_inferior ();
5876
 
5877
  inf_status->stop_step = tp->stop_step;
5878
  inf_status->stop_stack_dummy = stop_stack_dummy;
5879
  inf_status->stopped_by_random_signal = stopped_by_random_signal;
5880
  inf_status->stepping_over_breakpoint = tp->trap_expected;
5881
  inf_status->step_range_start = tp->step_range_start;
5882
  inf_status->step_range_end = tp->step_range_end;
5883
  inf_status->step_frame_id = tp->step_frame_id;
5884
  inf_status->step_stack_frame_id = tp->step_stack_frame_id;
5885
  inf_status->step_over_calls = tp->step_over_calls;
5886
  inf_status->stop_after_trap = stop_after_trap;
5887
  inf_status->stop_soon = inf->stop_soon;
5888
  /* Save original bpstat chain here; replace it with copy of chain.
5889
     If caller's caller is walking the chain, they'll be happier if we
5890
     hand them back the original chain when restore_inferior_status is
5891
     called.  */
5892
  inf_status->stop_bpstat = tp->stop_bpstat;
5893
  tp->stop_bpstat = bpstat_copy (tp->stop_bpstat);
5894
  inf_status->proceed_to_finish = tp->proceed_to_finish;
5895
  inf_status->in_infcall = tp->in_infcall;
5896
 
5897
  inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
5898
 
5899
  return inf_status;
5900
}
5901
 
5902
static int
5903
restore_selected_frame (void *args)
5904
{
5905
  struct frame_id *fid = (struct frame_id *) args;
5906
  struct frame_info *frame;
5907
 
5908
  frame = frame_find_by_id (*fid);
5909
 
5910
  /* If inf_status->selected_frame_id is NULL, there was no previously
5911
     selected frame.  */
5912
  if (frame == NULL)
5913
    {
5914
      warning (_("Unable to restore previously selected frame."));
5915
      return 0;
5916
    }
5917
 
5918
  select_frame (frame);
5919
 
5920
  return (1);
5921
}
5922
 
5923
/* Restore inferior session state to INF_STATUS.  */
5924
 
5925
void
5926
restore_inferior_status (struct inferior_status *inf_status)
5927
{
5928
  struct thread_info *tp = inferior_thread ();
5929
  struct inferior *inf = current_inferior ();
5930
 
5931
  tp->stop_step = inf_status->stop_step;
5932
  stop_stack_dummy = inf_status->stop_stack_dummy;
5933
  stopped_by_random_signal = inf_status->stopped_by_random_signal;
5934
  tp->trap_expected = inf_status->stepping_over_breakpoint;
5935
  tp->step_range_start = inf_status->step_range_start;
5936
  tp->step_range_end = inf_status->step_range_end;
5937
  tp->step_frame_id = inf_status->step_frame_id;
5938
  tp->step_stack_frame_id = inf_status->step_stack_frame_id;
5939
  tp->step_over_calls = inf_status->step_over_calls;
5940
  stop_after_trap = inf_status->stop_after_trap;
5941
  inf->stop_soon = inf_status->stop_soon;
5942
  bpstat_clear (&tp->stop_bpstat);
5943
  tp->stop_bpstat = inf_status->stop_bpstat;
5944
  inf_status->stop_bpstat = NULL;
5945
  tp->proceed_to_finish = inf_status->proceed_to_finish;
5946
  tp->in_infcall = inf_status->in_infcall;
5947
 
5948
  if (target_has_stack)
5949
    {
5950
      /* The point of catch_errors is that if the stack is clobbered,
5951
         walking the stack might encounter a garbage pointer and
5952
         error() trying to dereference it.  */
5953
      if (catch_errors
5954
          (restore_selected_frame, &inf_status->selected_frame_id,
5955
           "Unable to restore previously selected frame:\n",
5956
           RETURN_MASK_ERROR) == 0)
5957
        /* Error in restoring the selected frame.  Select the innermost
5958
           frame.  */
5959
        select_frame (get_current_frame ());
5960
    }
5961
 
5962
  xfree (inf_status);
5963
}
5964
 
5965
static void
5966
do_restore_inferior_status_cleanup (void *sts)
5967
{
5968
  restore_inferior_status (sts);
5969
}
5970
 
5971
struct cleanup *
5972
make_cleanup_restore_inferior_status (struct inferior_status *inf_status)
5973
{
5974
  return make_cleanup (do_restore_inferior_status_cleanup, inf_status);
5975
}
5976
 
5977
void
5978
discard_inferior_status (struct inferior_status *inf_status)
5979
{
5980
  /* See save_inferior_status for info on stop_bpstat. */
5981
  bpstat_clear (&inf_status->stop_bpstat);
5982
  xfree (inf_status);
5983
}
5984
 
5985
int
5986
inferior_has_forked (ptid_t pid, ptid_t *child_pid)
5987
{
5988
  struct target_waitstatus last;
5989
  ptid_t last_ptid;
5990
 
5991
  get_last_target_status (&last_ptid, &last);
5992
 
5993
  if (last.kind != TARGET_WAITKIND_FORKED)
5994
    return 0;
5995
 
5996
  if (!ptid_equal (last_ptid, pid))
5997
    return 0;
5998
 
5999
  *child_pid = last.value.related_pid;
6000
  return 1;
6001
}
6002
 
6003
int
6004
inferior_has_vforked (ptid_t pid, ptid_t *child_pid)
6005
{
6006
  struct target_waitstatus last;
6007
  ptid_t last_ptid;
6008
 
6009
  get_last_target_status (&last_ptid, &last);
6010
 
6011
  if (last.kind != TARGET_WAITKIND_VFORKED)
6012
    return 0;
6013
 
6014
  if (!ptid_equal (last_ptid, pid))
6015
    return 0;
6016
 
6017
  *child_pid = last.value.related_pid;
6018
  return 1;
6019
}
6020
 
6021
int
6022
inferior_has_execd (ptid_t pid, char **execd_pathname)
6023
{
6024
  struct target_waitstatus last;
6025
  ptid_t last_ptid;
6026
 
6027
  get_last_target_status (&last_ptid, &last);
6028
 
6029
  if (last.kind != TARGET_WAITKIND_EXECD)
6030
    return 0;
6031
 
6032
  if (!ptid_equal (last_ptid, pid))
6033
    return 0;
6034
 
6035
  *execd_pathname = xstrdup (last.value.execd_pathname);
6036
  return 1;
6037
}
6038
 
6039
int
6040
inferior_has_called_syscall (ptid_t pid, int *syscall_number)
6041
{
6042
  struct target_waitstatus last;
6043
  ptid_t last_ptid;
6044
 
6045
  get_last_target_status (&last_ptid, &last);
6046
 
6047
  if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY &&
6048
      last.kind != TARGET_WAITKIND_SYSCALL_RETURN)
6049
    return 0;
6050
 
6051
  if (!ptid_equal (last_ptid, pid))
6052
    return 0;
6053
 
6054
  *syscall_number = last.value.syscall_number;
6055
  return 1;
6056
}
6057
 
6058
/* Oft used ptids */
6059
ptid_t null_ptid;
6060
ptid_t minus_one_ptid;
6061
 
6062
/* Create a ptid given the necessary PID, LWP, and TID components.  */
6063
 
6064
ptid_t
6065
ptid_build (int pid, long lwp, long tid)
6066
{
6067
  ptid_t ptid;
6068
 
6069
  ptid.pid = pid;
6070
  ptid.lwp = lwp;
6071
  ptid.tid = tid;
6072
  return ptid;
6073
}
6074
 
6075
/* Create a ptid from just a pid.  */
6076
 
6077
ptid_t
6078
pid_to_ptid (int pid)
6079
{
6080
  return ptid_build (pid, 0, 0);
6081
}
6082
 
6083
/* Fetch the pid (process id) component from a ptid.  */
6084
 
6085
int
6086
ptid_get_pid (ptid_t ptid)
6087
{
6088
  return ptid.pid;
6089
}
6090
 
6091
/* Fetch the lwp (lightweight process) component from a ptid.  */
6092
 
6093
long
6094
ptid_get_lwp (ptid_t ptid)
6095
{
6096
  return ptid.lwp;
6097
}
6098
 
6099
/* Fetch the tid (thread id) component from a ptid.  */
6100
 
6101
long
6102
ptid_get_tid (ptid_t ptid)
6103
{
6104
  return ptid.tid;
6105
}
6106
 
6107
/* ptid_equal() is used to test equality of two ptids.  */
6108
 
6109
int
6110
ptid_equal (ptid_t ptid1, ptid_t ptid2)
6111
{
6112
  return (ptid1.pid == ptid2.pid && ptid1.lwp == ptid2.lwp
6113
          && ptid1.tid == ptid2.tid);
6114
}
6115
 
6116
/* Returns true if PTID represents a process.  */
6117
 
6118
int
6119
ptid_is_pid (ptid_t ptid)
6120
{
6121
  if (ptid_equal (minus_one_ptid, ptid))
6122
    return 0;
6123
  if (ptid_equal (null_ptid, ptid))
6124
    return 0;
6125
 
6126
  return (ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) == 0);
6127
}
6128
 
6129
/* restore_inferior_ptid() will be used by the cleanup machinery
6130
   to restore the inferior_ptid value saved in a call to
6131
   save_inferior_ptid().  */
6132
 
6133
static void
6134
restore_inferior_ptid (void *arg)
6135
{
6136
  ptid_t *saved_ptid_ptr = arg;
6137
  inferior_ptid = *saved_ptid_ptr;
6138
  xfree (arg);
6139
}
6140
 
6141
/* Save the value of inferior_ptid so that it may be restored by a
6142
   later call to do_cleanups().  Returns the struct cleanup pointer
6143
   needed for later doing the cleanup.  */
6144
 
6145
struct cleanup *
6146
save_inferior_ptid (void)
6147
{
6148
  ptid_t *saved_ptid_ptr;
6149
 
6150
  saved_ptid_ptr = xmalloc (sizeof (ptid_t));
6151
  *saved_ptid_ptr = inferior_ptid;
6152
  return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
6153
}
6154
 
6155
 
6156
/* User interface for reverse debugging:
6157
   Set exec-direction / show exec-direction commands
6158
   (returns error unless target implements to_set_exec_direction method).  */
6159
 
6160
enum exec_direction_kind execution_direction = EXEC_FORWARD;
6161
static const char exec_forward[] = "forward";
6162
static const char exec_reverse[] = "reverse";
6163
static const char *exec_direction = exec_forward;
6164
static const char *exec_direction_names[] = {
6165
  exec_forward,
6166
  exec_reverse,
6167
  NULL
6168
};
6169
 
6170
static void
6171
set_exec_direction_func (char *args, int from_tty,
6172
                         struct cmd_list_element *cmd)
6173
{
6174
  if (target_can_execute_reverse)
6175
    {
6176
      if (!strcmp (exec_direction, exec_forward))
6177
        execution_direction = EXEC_FORWARD;
6178
      else if (!strcmp (exec_direction, exec_reverse))
6179
        execution_direction = EXEC_REVERSE;
6180
    }
6181
}
6182
 
6183
static void
6184
show_exec_direction_func (struct ui_file *out, int from_tty,
6185
                          struct cmd_list_element *cmd, const char *value)
6186
{
6187
  switch (execution_direction) {
6188
  case EXEC_FORWARD:
6189
    fprintf_filtered (out, _("Forward.\n"));
6190
    break;
6191
  case EXEC_REVERSE:
6192
    fprintf_filtered (out, _("Reverse.\n"));
6193
    break;
6194
  case EXEC_ERROR:
6195
  default:
6196
    fprintf_filtered (out,
6197
                      _("Forward (target `%s' does not support exec-direction).\n"),
6198
                      target_shortname);
6199
    break;
6200
  }
6201
}
6202
 
6203
/* User interface for non-stop mode.  */
6204
 
6205
int non_stop = 0;
6206
static int non_stop_1 = 0;
6207
 
6208
static void
6209
set_non_stop (char *args, int from_tty,
6210
              struct cmd_list_element *c)
6211
{
6212
  if (target_has_execution)
6213
    {
6214
      non_stop_1 = non_stop;
6215
      error (_("Cannot change this setting while the inferior is running."));
6216
    }
6217
 
6218
  non_stop = non_stop_1;
6219
}
6220
 
6221
static void
6222
show_non_stop (struct ui_file *file, int from_tty,
6223
               struct cmd_list_element *c, const char *value)
6224
{
6225
  fprintf_filtered (file,
6226
                    _("Controlling the inferior in non-stop mode is %s.\n"),
6227
                    value);
6228
}
6229
 
6230
static void
6231
show_schedule_multiple (struct ui_file *file, int from_tty,
6232
                        struct cmd_list_element *c, const char *value)
6233
{
6234
  fprintf_filtered (file, _("\
6235
Resuming the execution of threads of all processes is %s.\n"), value);
6236
}
6237
 
6238
void
6239
_initialize_infrun (void)
6240
{
6241
  int i;
6242
  int numsigs;
6243
  struct cmd_list_element *c;
6244
 
6245
  add_info ("signals", signals_info, _("\
6246
What debugger does when program gets various signals.\n\
6247
Specify a signal as argument to print info on that signal only."));
6248
  add_info_alias ("handle", "signals", 0);
6249
 
6250
  add_com ("handle", class_run, handle_command, _("\
6251
Specify how to handle a signal.\n\
6252
Args are signals and actions to apply to those signals.\n\
6253
Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6254
from 1-15 are allowed for compatibility with old versions of GDB.\n\
6255
Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6256
The special arg \"all\" is recognized to mean all signals except those\n\
6257
used by the debugger, typically SIGTRAP and SIGINT.\n\
6258
Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
6259
\"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
6260
Stop means reenter debugger if this signal happens (implies print).\n\
6261
Print means print a message if this signal happens.\n\
6262
Pass means let program see this signal; otherwise program doesn't know.\n\
6263
Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
6264
Pass and Stop may be combined."));
6265
  if (xdb_commands)
6266
    {
6267
      add_com ("lz", class_info, signals_info, _("\
6268
What debugger does when program gets various signals.\n\
6269
Specify a signal as argument to print info on that signal only."));
6270
      add_com ("z", class_run, xdb_handle_command, _("\
6271
Specify how to handle a signal.\n\
6272
Args are signals and actions to apply to those signals.\n\
6273
Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6274
from 1-15 are allowed for compatibility with old versions of GDB.\n\
6275
Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6276
The special arg \"all\" is recognized to mean all signals except those\n\
6277
used by the debugger, typically SIGTRAP and SIGINT.\n\
6278
Recognized actions include \"s\" (toggles between stop and nostop), \n\
6279
\"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
6280
nopass), \"Q\" (noprint)\n\
6281
Stop means reenter debugger if this signal happens (implies print).\n\
6282
Print means print a message if this signal happens.\n\
6283
Pass means let program see this signal; otherwise program doesn't know.\n\
6284
Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
6285
Pass and Stop may be combined."));
6286
    }
6287
 
6288
  if (!dbx_commands)
6289
    stop_command = add_cmd ("stop", class_obscure,
6290
                            not_just_help_class_command, _("\
6291
There is no `stop' command, but you can set a hook on `stop'.\n\
6292
This allows you to set a list of commands to be run each time execution\n\
6293
of the program stops."), &cmdlist);
6294
 
6295
  add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
6296
Set inferior debugging."), _("\
6297
Show inferior debugging."), _("\
6298
When non-zero, inferior specific debugging is enabled."),
6299
                            NULL,
6300
                            show_debug_infrun,
6301
                            &setdebuglist, &showdebuglist);
6302
 
6303
  add_setshow_boolean_cmd ("displaced", class_maintenance, &debug_displaced, _("\
6304
Set displaced stepping debugging."), _("\
6305
Show displaced stepping debugging."), _("\
6306
When non-zero, displaced stepping specific debugging is enabled."),
6307
                            NULL,
6308
                            show_debug_displaced,
6309
                            &setdebuglist, &showdebuglist);
6310
 
6311
  add_setshow_boolean_cmd ("non-stop", no_class,
6312
                           &non_stop_1, _("\
6313
Set whether gdb controls the inferior in non-stop mode."), _("\
6314
Show whether gdb controls the inferior in non-stop mode."), _("\
6315
When debugging a multi-threaded program and this setting is\n\
6316
off (the default, also called all-stop mode), when one thread stops\n\
6317
(for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
6318
all other threads in the program while you interact with the thread of\n\
6319
interest.  When you continue or step a thread, you can allow the other\n\
6320
threads to run, or have them remain stopped, but while you inspect any\n\
6321
thread's state, all threads stop.\n\
6322
\n\
6323
In non-stop mode, when one thread stops, other threads can continue\n\
6324
to run freely.  You'll be able to step each thread independently,\n\
6325
leave it stopped or free to run as needed."),
6326
                           set_non_stop,
6327
                           show_non_stop,
6328
                           &setlist,
6329
                           &showlist);
6330
 
6331
  numsigs = (int) TARGET_SIGNAL_LAST;
6332
  signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
6333
  signal_print = (unsigned char *)
6334
    xmalloc (sizeof (signal_print[0]) * numsigs);
6335
  signal_program = (unsigned char *)
6336
    xmalloc (sizeof (signal_program[0]) * numsigs);
6337
  for (i = 0; i < numsigs; i++)
6338
    {
6339
      signal_stop[i] = 1;
6340
      signal_print[i] = 1;
6341
      signal_program[i] = 1;
6342
    }
6343
 
6344
  /* Signals caused by debugger's own actions
6345
     should not be given to the program afterwards.  */
6346
  signal_program[TARGET_SIGNAL_TRAP] = 0;
6347
  signal_program[TARGET_SIGNAL_INT] = 0;
6348
 
6349
  /* Signals that are not errors should not normally enter the debugger.  */
6350
  signal_stop[TARGET_SIGNAL_ALRM] = 0;
6351
  signal_print[TARGET_SIGNAL_ALRM] = 0;
6352
  signal_stop[TARGET_SIGNAL_VTALRM] = 0;
6353
  signal_print[TARGET_SIGNAL_VTALRM] = 0;
6354
  signal_stop[TARGET_SIGNAL_PROF] = 0;
6355
  signal_print[TARGET_SIGNAL_PROF] = 0;
6356
  signal_stop[TARGET_SIGNAL_CHLD] = 0;
6357
  signal_print[TARGET_SIGNAL_CHLD] = 0;
6358
  signal_stop[TARGET_SIGNAL_IO] = 0;
6359
  signal_print[TARGET_SIGNAL_IO] = 0;
6360
  signal_stop[TARGET_SIGNAL_POLL] = 0;
6361
  signal_print[TARGET_SIGNAL_POLL] = 0;
6362
  signal_stop[TARGET_SIGNAL_URG] = 0;
6363
  signal_print[TARGET_SIGNAL_URG] = 0;
6364
  signal_stop[TARGET_SIGNAL_WINCH] = 0;
6365
  signal_print[TARGET_SIGNAL_WINCH] = 0;
6366
 
6367
  /* These signals are used internally by user-level thread
6368
     implementations.  (See signal(5) on Solaris.)  Like the above
6369
     signals, a healthy program receives and handles them as part of
6370
     its normal operation.  */
6371
  signal_stop[TARGET_SIGNAL_LWP] = 0;
6372
  signal_print[TARGET_SIGNAL_LWP] = 0;
6373
  signal_stop[TARGET_SIGNAL_WAITING] = 0;
6374
  signal_print[TARGET_SIGNAL_WAITING] = 0;
6375
  signal_stop[TARGET_SIGNAL_CANCEL] = 0;
6376
  signal_print[TARGET_SIGNAL_CANCEL] = 0;
6377
 
6378
  add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
6379
                            &stop_on_solib_events, _("\
6380
Set stopping for shared library events."), _("\
6381
Show stopping for shared library events."), _("\
6382
If nonzero, gdb will give control to the user when the dynamic linker\n\
6383
notifies gdb of shared library events.  The most common event of interest\n\
6384
to the user would be loading/unloading of a new library."),
6385
                            NULL,
6386
                            show_stop_on_solib_events,
6387
                            &setlist, &showlist);
6388
 
6389
  add_setshow_enum_cmd ("follow-fork-mode", class_run,
6390
                        follow_fork_mode_kind_names,
6391
                        &follow_fork_mode_string, _("\
6392
Set debugger response to a program call of fork or vfork."), _("\
6393
Show debugger response to a program call of fork or vfork."), _("\
6394
A fork or vfork creates a new process.  follow-fork-mode can be:\n\
6395
  parent  - the original process is debugged after a fork\n\
6396
  child   - the new process is debugged after a fork\n\
6397
The unfollowed process will continue to run.\n\
6398
By default, the debugger will follow the parent process."),
6399
                        NULL,
6400
                        show_follow_fork_mode_string,
6401
                        &setlist, &showlist);
6402
 
6403
  add_setshow_enum_cmd ("follow-exec-mode", class_run,
6404
                        follow_exec_mode_names,
6405
                        &follow_exec_mode_string, _("\
6406
Set debugger response to a program call of exec."), _("\
6407
Show debugger response to a program call of exec."), _("\
6408
An exec call replaces the program image of a process.\n\
6409
\n\
6410
follow-exec-mode can be:\n\
6411
\n\
6412
  new - the debugger creates a new inferior and rebinds the process \n\
6413
to this new inferior.  The program the process was running before\n\
6414
the exec call can be restarted afterwards by restarting the original\n\
6415
inferior.\n\
6416
\n\
6417
  same - the debugger keeps the process bound to the same inferior.\n\
6418
The new executable image replaces the previous executable loaded in\n\
6419
the inferior.  Restarting the inferior after the exec call restarts\n\
6420
the executable the process was running after the exec call.\n\
6421
\n\
6422
By default, the debugger will use the same inferior."),
6423
                        NULL,
6424
                        show_follow_exec_mode_string,
6425
                        &setlist, &showlist);
6426
 
6427
  add_setshow_enum_cmd ("scheduler-locking", class_run,
6428
                        scheduler_enums, &scheduler_mode, _("\
6429
Set mode for locking scheduler during execution."), _("\
6430
Show mode for locking scheduler during execution."), _("\
6431
off  == no locking (threads may preempt at any time)\n\
6432
on   == full locking (no thread except the current thread may run)\n\
6433
step == scheduler locked during every single-step operation.\n\
6434
        In this mode, no other thread may run during a step command.\n\
6435
        Other threads may run while stepping over a function call ('next')."),
6436
                        set_schedlock_func,     /* traps on target vector */
6437
                        show_scheduler_mode,
6438
                        &setlist, &showlist);
6439
 
6440
  add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
6441
Set mode for resuming threads of all processes."), _("\
6442
Show mode for resuming threads of all processes."), _("\
6443
When on, execution commands (such as 'continue' or 'next') resume all\n\
6444
threads of all processes.  When off (which is the default), execution\n\
6445
commands only resume the threads of the current process.  The set of\n\
6446
threads that are resumed is further refined by the scheduler-locking\n\
6447
mode (see help set scheduler-locking)."),
6448
                           NULL,
6449
                           show_schedule_multiple,
6450
                           &setlist, &showlist);
6451
 
6452
  add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
6453
Set mode of the step operation."), _("\
6454
Show mode of the step operation."), _("\
6455
When set, doing a step over a function without debug line information\n\
6456
will stop at the first instruction of that function. Otherwise, the\n\
6457
function is skipped and the step command stops at a different source line."),
6458
                           NULL,
6459
                           show_step_stop_if_no_debug,
6460
                           &setlist, &showlist);
6461
 
6462
  add_setshow_enum_cmd ("displaced-stepping", class_run,
6463
                        can_use_displaced_stepping_enum,
6464
                        &can_use_displaced_stepping, _("\
6465
Set debugger's willingness to use displaced stepping."), _("\
6466
Show debugger's willingness to use displaced stepping."), _("\
6467
If on, gdb will use displaced stepping to step over breakpoints if it is\n\
6468
supported by the target architecture.  If off, gdb will not use displaced\n\
6469
stepping to step over breakpoints, even if such is supported by the target\n\
6470
architecture.  If auto (which is the default), gdb will use displaced stepping\n\
6471
if the target architecture supports it and non-stop mode is active, but will not\n\
6472
use it in all-stop mode (see help set non-stop)."),
6473
                        NULL,
6474
                        show_can_use_displaced_stepping,
6475
                        &setlist, &showlist);
6476
 
6477
  add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
6478
                        &exec_direction, _("Set direction of execution.\n\
6479
Options are 'forward' or 'reverse'."),
6480
                        _("Show direction of execution (forward/reverse)."),
6481
                        _("Tells gdb whether to execute forward or backward."),
6482
                        set_exec_direction_func, show_exec_direction_func,
6483
                        &setlist, &showlist);
6484
 
6485
  /* Set/show detach-on-fork: user-settable mode.  */
6486
 
6487
  add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
6488
Set whether gdb will detach the child of a fork."), _("\
6489
Show whether gdb will detach the child of a fork."), _("\
6490
Tells gdb whether to detach the child of a fork."),
6491
                           NULL, NULL, &setlist, &showlist);
6492
 
6493
  /* ptid initializations */
6494
  null_ptid = ptid_build (0, 0, 0);
6495
  minus_one_ptid = ptid_build (-1, 0, 0);
6496
  inferior_ptid = null_ptid;
6497
  target_last_wait_ptid = minus_one_ptid;
6498
  displaced_step_ptid = null_ptid;
6499
 
6500
  observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
6501
  observer_attach_thread_stop_requested (infrun_thread_stop_requested);
6502
  observer_attach_thread_exit (infrun_thread_thread_exit);
6503
 
6504
  /* Explicitly create without lookup, since that tries to create a
6505
     value with a void typed value, and when we get here, gdbarch
6506
     isn't initialized yet.  At this point, we're quite sure there
6507
     isn't another convenience variable of the same name.  */
6508
  create_internalvar_type_lazy ("_siginfo", siginfo_make_value);
6509
}

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