aboutsummaryrefslogtreecommitdiff
path: root/gdb/windows-nat.c
blob: 24d8057cc8fa9ced8254e84055ce41e76360ad11 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
/* Target-vector operations for controlling win32 child processes, for GDB.
   Copyright 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
   Contributed by Cygnus Support.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

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

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.
 */

/* by Steve Chamberlain, sac@cygnus.com */

/* We assume we're being built with and will be used for cygwin.  */

#include "defs.h"
#include "frame.h"		/* required by inferior.h */
#include "inferior.h"
#include "target.h"
#include "wait.h"
#include "gdbcore.h"
#include "command.h"
#include <signal.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdlib.h>

#ifdef _MSC_VER
#include "windefs.h"
#else /* other WIN32 compiler */
#include <windows.h>
#endif

#include "buildsym.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdb_string.h"
#include "gdbthread.h"
#include "gdbcmd.h"
#include <sys/param.h>

/* The ui's event loop. */
extern int (*ui_loop_hook) PARAMS ((int signo));

/* If we're not using the old Cygwin header file set, define the
   following which never should have been in the generic Win32 API
   headers in the first place since they were our own invention... */
#ifndef _GNU_H_WINDOWS_H
#define FLAG_TRACE_BIT 0x100
#define CONTEXT_DEBUGGER (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
#endif

/* The string sent by cygwin when it processes a signal.
   FIXME: This should be in a cygwin include file. */
#define CYGWIN_SIGNAL_STRING "cygwin: signal"

#define CHECK(x) 	check (x, __FILE__,__LINE__)
#define DEBUG_EXEC(x)	if (debug_exec)		printf x
#define DEBUG_EVENTS(x)	if (debug_events)	printf x
#define DEBUG_MEM(x)	if (debug_memory)	printf x
#define DEBUG_EXCEPT(x)	if (debug_exceptions)	printf x

/* Forward declaration */
extern struct target_ops child_ops;

static void child_stop PARAMS ((void));
static int win32_child_thread_alive PARAMS ((int));
void child_kill_inferior PARAMS ((void));

static int last_sig = 0;	/* Set if a signal was received from the
				   debugged process */

/* Thread information structure used to track information that is
   not available in gdb's thread structure. */
typedef struct thread_info_struct
  {
    struct thread_info_struct *next;
    DWORD id;
    HANDLE h;
    char *name;
    int suspend_count;
    CONTEXT context;
  }
thread_info;

static thread_info thread_head =
{NULL};

/* The process and thread handles for the above context. */

static DEBUG_EVENT current_event;	/* The current debug event from
					   WaitForDebugEvent */
static HANDLE current_process_handle;	/* Currently executing process */
static thread_info *current_thread;	/* Info on currently selected thread */
static DWORD main_thread_id;	/* Thread ID of the main thread */

/* Counts of things. */
static int exception_count = 0;
static int event_count = 0;

/* User options. */
static int new_console = 0;
static int new_group = 0;
static int debug_exec = 0;	/* show execution */
static int debug_events = 0;	/* show events from kernel */
static int debug_memory = 0;	/* show target memory accesses */
static int debug_exceptions = 0;	/* show target exceptions */

/* This vector maps GDB's idea of a register's number into an address
   in the win32 exception context vector.

   It also contains the bit mask needed to load the register in question.

   One day we could read a reg, we could inspect the context we
   already have loaded, if it doesn't have the bit set that we need,
   we read that set of registers in using GetThreadContext.  If the
   context already contains what we need, we just unpack it. Then to
   write a register, first we have to ensure that the context contains
   the other regs of the group, and then we copy the info in and set
   out bit. */

#define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
static const int mappings[] =
{
  context_offset (Eax),
  context_offset (Ecx),
  context_offset (Edx),
  context_offset (Ebx),
  context_offset (Esp),
  context_offset (Ebp),
  context_offset (Esi),
  context_offset (Edi),
  context_offset (Eip),
  context_offset (EFlags),
  context_offset (SegCs),
  context_offset (SegSs),
  context_offset (SegDs),
  context_offset (SegEs),
  context_offset (SegFs),
  context_offset (SegGs),
  context_offset (FloatSave.RegisterArea[0 * 10]),
  context_offset (FloatSave.RegisterArea[1 * 10]),
  context_offset (FloatSave.RegisterArea[2 * 10]),
  context_offset (FloatSave.RegisterArea[3 * 10]),
  context_offset (FloatSave.RegisterArea[4 * 10]),
  context_offset (FloatSave.RegisterArea[5 * 10]),
  context_offset (FloatSave.RegisterArea[6 * 10]),
  context_offset (FloatSave.RegisterArea[7 * 10]),
};

/* This vector maps the target's idea of an exception (extracted
   from the DEBUG_EVENT structure) to GDB's idea. */

struct xlate_exception
  {
    int them;
    enum target_signal us;
  };

static const struct xlate_exception
  xlate[] =
{
  {EXCEPTION_ACCESS_VIOLATION, TARGET_SIGNAL_SEGV},
  {STATUS_STACK_OVERFLOW, TARGET_SIGNAL_SEGV},
  {EXCEPTION_BREAKPOINT, TARGET_SIGNAL_TRAP},
  {DBG_CONTROL_C, TARGET_SIGNAL_INT},
  {EXCEPTION_SINGLE_STEP, TARGET_SIGNAL_TRAP},
  {-1, -1}};

/* Find a thread record given a thread id.
   If get_context then also retrieve the context for this
   thread. */
static thread_info *
thread_rec (DWORD id, int get_context)
{
  thread_info *th;

  for (th = &thread_head; (th = th->next) != NULL;)
    if (th->id == id)
      {
	if (!th->suspend_count && get_context)
	  {
	    if (get_context > 0)
	      th->suspend_count = SuspendThread (th->h) + 1;
	    else if (get_context < 0)
	      th->suspend_count = -1;

	    th->context.ContextFlags = CONTEXT_DEBUGGER;
	    GetThreadContext (th->h, &th->context);
	  }
	return th;
      }

  return NULL;
}

/* Add a thread to the thread list */
static thread_info *
child_add_thread (DWORD id, HANDLE h)
{
  thread_info *th;

  if ((th = thread_rec (id, FALSE)))
    return th;

  th = (thread_info *) xmalloc (sizeof (*th));
  memset (th, 0, sizeof (*th));
  th->id = id;
  th->h = h;
  th->next = thread_head.next;
  thread_head.next = th;
  add_thread (id);
  return th;
}

/* Clear out any old thread list and reintialize it to a
   pristine state. */
static void
child_init_thread_list ()
{
  thread_info *th = &thread_head;

  DEBUG_EVENTS (("gdb: child_init_thread_list\n"));
  init_thread_list ();
  while (th->next != NULL)
    {
      thread_info *here = th->next;
      th->next = here->next;
      (void) CloseHandle (here->h);
      free (here);
    }
}

/* Delete a thread from the list of threads */
static void
child_delete_thread (DWORD id)
{
  thread_info *th;

  if (info_verbose)
    printf_unfiltered ("[Deleting %s]\n", target_pid_to_str (id));
  delete_thread (id);

  for (th = &thread_head;
       th->next != NULL && th->next->id != id;
       th = th->next)
    continue;

  if (th->next != NULL)
    {
      thread_info *here = th->next;
      th->next = here->next;
      CloseHandle (here->h);
      free (here);
    }
}

static void
check (BOOL ok, const char *file, int line)
{
  if (!ok)
    printf_filtered ("error return %s:%d was %d\n", file, line, GetLastError ());
}

static void
do_child_fetch_inferior_registers (int r)
{
  if (r >= 0)
    supply_register (r, ((char *) &current_thread->context) + mappings[r]);
  else
    {
      for (r = 0; r < NUM_REGS; r++)
	do_child_fetch_inferior_registers (r);
    }
}

static void
child_fetch_inferior_registers (int r)
{
  current_thread = thread_rec (inferior_pid, TRUE);
  do_child_fetch_inferior_registers (r);
}

static void
do_child_store_inferior_registers (int r)
{
  if (r >= 0)
    read_register_gen (r, ((char *) &current_thread->context) + mappings[r]);
  else
    {
      for (r = 0; r < NUM_REGS; r++)
	do_child_store_inferior_registers (r);
    }
}

/* Store a new register value into the current thread context */
static void
child_store_inferior_registers (int r)
{
  current_thread = thread_rec (inferior_pid, TRUE);
  do_child_store_inferior_registers (r);
}

/* Wait for child to do something.  Return pid of child, or -1 in case
   of error; store status through argument pointer OURSTATUS.  */

static int
handle_load_dll (PTR dummy)
{
  LOAD_DLL_DEBUG_INFO *event = &current_event.u.LoadDll;
  DWORD dll_name_ptr;
  DWORD done;
  char dll_buf[MAX_PATH + 1];
  char *p, *dll_name = NULL;
  struct objfile *objfile;
  MEMORY_BASIC_INFORMATION minfo;
  struct section_addr_info section_addrs;

  memset (&section_addrs, 0, sizeof (section_addrs));
  dll_buf[0] = dll_buf[sizeof (dll_buf) - 1] = '\0';

  /* The following code attempts to find the name of the dll by reading the
     name from the processes memory.  Unfortunately it doesn't work right.
     Doing this the "right way" for Windows is very difficult.  FIXME */
#ifdef DOESNT_WORK
  memset (&minfo, 0, sizeof minfo);
  if (VirtualQueryEx (current_process_handle, (LPCVOID) event->lpBaseOfDll,
		      &minfo, sizeof (minfo)) && minfo.BaseAddress)
    {
      DWORD len;
      IMAGE_DOS_HEADER *hmm0 = (IMAGE_DOS_HEADER *) minfo.BaseAddress;
      HMODULE hmm = (HMODULE) (((DWORD) hmm0) + hmm0->e_lfanew);

      if ((len = GetModuleFileName (hmm, dll_buf, MAX_PATH)))
	{
	  dll_name = dll_buf;
	  dll_name[len] = '\0';
	}
    }
#endif

  /* Attempt to read the name of the dll that was detected.
     This is documented to work only when actively debugging
     a program.  It will not work for attached processes. */
  if (dll_name == NULL || *dll_name == '\0')
    {
      int size = event->fUnicode ? sizeof (WCHAR) : sizeof (char);
      int len = 0;
      char b[2];

      ReadProcessMemory (current_process_handle,
			 (LPCVOID) event->lpImageName,
			 (char *) &dll_name_ptr,
			 sizeof (dll_name_ptr), &done);

      /* See if we could read the address of a string, and that the
         address isn't null. */

      if (done != sizeof (dll_name_ptr) || !dll_name_ptr)
	return 1;

      do
	{
	  ReadProcessMemory (current_process_handle,
			     (LPCVOID) (dll_name_ptr + len * size),
			     &b,
			     size,
			     &done);
	  len++;
	}
      while ((b[0] != 0 || b[size - 1] != 0) && done == size);

      dll_name = alloca (len);

      if (event->fUnicode)
	{
	  WCHAR *unicode_dll_name = (WCHAR *) alloca (len * sizeof (WCHAR));
	  ReadProcessMemory (current_process_handle,
			     (LPCVOID) dll_name_ptr,
			     unicode_dll_name,
			     len * sizeof (WCHAR),
			     &done);

	  WideCharToMultiByte (CP_ACP, 0,
			       unicode_dll_name, len,
			       dll_name, len, 0, 0);
	}
      else
	{
	  ReadProcessMemory (current_process_handle,
			     (LPCVOID) dll_name_ptr,
			     dll_name,
			     len,
			     &done);
	}
    }

  if (!dll_name)
    return 1;

  while ((p = strchr (dll_name, '\\')))
    *p = '/';

  /* The symbols in a dll are offset by 0x1000, which is the
     the offset from 0 of the first byte in an image - because
     of the file header and the section alignment.

     FIXME: Is this the real reason that we need the 0x1000 ? */

  printf_unfiltered ("%x:%s", event->lpBaseOfDll, dll_name);
  section_addrs.text_addr = (int) event->lpBaseOfDll + 0x1000;
  symbol_file_add (dll_name, 0, &section_addrs, 0, OBJF_SHARED);
  printf_unfiltered ("\n");

  return 1;
}

/* Handle DEBUG_STRING output from child process.
   Cygwin prepends its messages with a "cygwin:".  Interpret this as
   a Cygwin signal.  Otherwise just print the string as a warning. */
static int
handle_output_debug_string (struct target_waitstatus *ourstatus)
{
  char *s;
  int gotasig = FALSE;

  if (!target_read_string
    ((CORE_ADDR) current_event.u.DebugString.lpDebugStringData, &s, 1024, 0)
      || !s || !*s)
    return gotasig;

  if (strncmp (s, CYGWIN_SIGNAL_STRING, sizeof (CYGWIN_SIGNAL_STRING) - 1))
    {
      warning (s);
    }
  else
    {
      char *p;
      /*last_sig = */ strtol (s + sizeof (CYGWIN_SIGNAL_STRING) - 1, &p, 0);
      gotasig = target_signal_from_host (last_sig);
      ourstatus->value.sig = gotasig;
      if (gotasig)
	ourstatus->kind = TARGET_WAITKIND_STOPPED;
    }

  free (s);
  return gotasig;
}

static int
handle_exception (struct target_waitstatus *ourstatus)
{
  int i;
  int done = 0;
  thread_info *th;

  ourstatus->kind = TARGET_WAITKIND_STOPPED;

  /* Record the context of the current thread */
  th = thread_rec (current_event.dwThreadId, -1);

  switch (current_event.u.Exception.ExceptionRecord.ExceptionCode)
    {
    case EXCEPTION_ACCESS_VIOLATION:
      DEBUG_EXCEPT (("gdb: Target exception ACCESS_VIOLATION at 0x%08x\n",
	       current_event.u.Exception.ExceptionRecord.ExceptionAddress));
      ourstatus->value.sig = TARGET_SIGNAL_SEGV;
      break;
    case STATUS_STACK_OVERFLOW:
      DEBUG_EXCEPT (("gdb: Target exception STACK_OVERFLOW at 0x%08x\n",
	       current_event.u.Exception.ExceptionRecord.ExceptionAddress));
      ourstatus->value.sig = TARGET_SIGNAL_SEGV;
      break;
    case EXCEPTION_BREAKPOINT:
      DEBUG_EXCEPT (("gdb: Target exception BREAKPOINT at 0x%08x\n",
	       current_event.u.Exception.ExceptionRecord.ExceptionAddress));
      ourstatus->value.sig = TARGET_SIGNAL_TRAP;
      break;
    case DBG_CONTROL_C:
      DEBUG_EXCEPT (("gdb: Target exception CONTROL_C at 0x%08x\n",
	       current_event.u.Exception.ExceptionRecord.ExceptionAddress));
      ourstatus->value.sig = TARGET_SIGNAL_INT;
      /* User typed CTRL-C.  Continue with this status */
      last_sig = SIGINT;	/* FIXME - should check pass state */
      break;
    case EXCEPTION_SINGLE_STEP:
      DEBUG_EXCEPT (("gdb: Target exception SINGLE_STEP at 0x%08x\n",
	       current_event.u.Exception.ExceptionRecord.ExceptionAddress));
      ourstatus->value.sig = TARGET_SIGNAL_TRAP;
      break;
    default:
      /* This may be a structured exception handling exception.  In
         that case, we want to let the program try to handle it, and
         only break if we see the exception a second time.  */
      if (current_event.u.Exception.dwFirstChance)
	return 0;

      printf_unfiltered ("gdb: unknown target exception 0x%08x at 0x%08x\n",
		    current_event.u.Exception.ExceptionRecord.ExceptionCode,
		current_event.u.Exception.ExceptionRecord.ExceptionAddress);
      ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
      break;
    }
  exception_count++;
  return 1;
}

/* Resume all artificially suspended threads if we are continuing
   execution */
static BOOL
child_continue (DWORD continue_status, int id)
{
  int i;
  thread_info *th;
  BOOL res;

  DEBUG_EVENTS (("ContinueDebugEvent (cpid=%d, ctid=%d, DBG_CONTINUE);\n",
		 current_event.dwProcessId, current_event.dwThreadId));
  res = ContinueDebugEvent (current_event.dwProcessId,
			    current_event.dwThreadId,
			    continue_status);
  if (res)
    for (th = &thread_head; (th = th->next) != NULL;)
      if (((id == -1) || (id == th->id)) && th->suspend_count)
	{
	  for (i = 0; i < th->suspend_count; i++)
	    (void) ResumeThread (th->h);
	  th->suspend_count = 0;
	}

  return res;
}

static int
child_wait (int pid, struct target_waitstatus *ourstatus)
{
  /* We loop when we get a non-standard exception rather than return
     with a SPURIOUS because resume can try and step or modify things,
     which needs a current_thread->h.  But some of these exceptions mark
     the birth or death of threads, which mean that the current thread
     isn't necessarily what you think it is. */

  while (1)
    {
      DWORD continue_status;
      BOOL debug_event = WaitForDebugEvent (&current_event, 20);
      char *p;
      thread_info *th;
      int sig;

      if (debug_event)
	{
	  event_count++;

	  continue_status = DBG_CONTINUE;

	  switch (current_event.dwDebugEventCode)
	    {
	    case CREATE_THREAD_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%x code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "CREATE_THREAD_DEBUG_EVENT"));
	      /* Record the existence of this thread */
	      child_add_thread (current_event.dwThreadId,
				current_event.u.CreateThread.hThread);
	      if (info_verbose)
		printf_unfiltered ("[New %s]\n",
			      target_pid_to_str (current_event.dwThreadId));
	      break;

	    case EXIT_THREAD_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "EXIT_THREAD_DEBUG_EVENT"));
	      child_delete_thread (current_event.dwThreadId);
	      break;

	    case CREATE_PROCESS_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "CREATE_PROCESS_DEBUG_EVENT"));
	      current_process_handle = current_event.u.CreateProcessInfo.hProcess;

	      main_thread_id = inferior_pid = current_event.dwThreadId;
	      /* Add the main thread */
	      current_thread = child_add_thread (inferior_pid,
				 current_event.u.CreateProcessInfo.hThread);
	      break;

	    case EXIT_PROCESS_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "EXIT_PROCESS_DEBUG_EVENT"));
	      ourstatus->kind = TARGET_WAITKIND_EXITED;
	      ourstatus->value.integer = current_event.u.ExitProcess.dwExitCode;
	      CloseHandle (current_process_handle);
	      return current_event.dwProcessId;
	      break;

	    case LOAD_DLL_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "LOAD_DLL_DEBUG_EVENT"));
	      catch_errors (handle_load_dll, NULL, "", RETURN_MASK_ALL);
	      registers_changed ();	/* mark all regs invalid */
	      break;

	    case UNLOAD_DLL_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "UNLOAD_DLL_DEBUG_EVENT"));
	      break;		/* FIXME: don't know what to do here */

	    case EXCEPTION_DEBUG_EVENT:
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "EXCEPTION_DEBUG_EVENT"));
	      if (handle_exception (ourstatus))
		return current_event.dwThreadId;
	      continue_status = DBG_EXCEPTION_NOT_HANDLED;
	      break;

	    case OUTPUT_DEBUG_STRING_EVENT:	/* message from the kernel */
	      DEBUG_EVENTS (("gdb: kernel event for pid=%d tid=%d code=%s)\n",
			current_event.dwProcessId, current_event.dwThreadId,
			     "OUTPUT_DEBUG_STRING_EVENT"));
	      if (handle_output_debug_string (ourstatus))
		return main_thread_id;
	      break;
	    default:
	      printf_unfiltered ("gdb: kernel event for pid=%d tid=%d\n",
				 current_event.dwProcessId,
				 current_event.dwThreadId);
	      printf_unfiltered ("                 unknown event code %d\n",
				 current_event.dwDebugEventCode);
	      break;
	    }

	  CHECK (child_continue (continue_status, -1));
	}
      else
	{
	  int detach = 0;

	  if (ui_loop_hook != NULL)
	    detach = ui_loop_hook (0);

	  if (detach)
	    child_kill_inferior ();
	}
    }
}

/* Attach to process PID, then initialize for debugging it.  */

static void
child_attach (args, from_tty)
     char *args;
     int from_tty;
{
  BOOL ok;

  if (!args)
    error_no_arg ("process-id to attach");

  current_event.dwProcessId = strtoul (args, 0, 0);

  ok = DebugActiveProcess (current_event.dwProcessId);

  if (!ok)
    error ("Can't attach to process.");

  exception_count = 0;
  event_count = 0;

  if (from_tty)
    {
      char *exec_file = (char *) get_exec_file (0);

      if (exec_file)
	printf_unfiltered ("Attaching to program `%s', %s\n", exec_file,
			   target_pid_to_str (current_event.dwProcessId));
      else
	printf_unfiltered ("Attaching to %s\n",
			   target_pid_to_str (current_event.dwProcessId));

      gdb_flush (gdb_stdout);
    }

  push_target (&child_ops);
}

static void
child_detach (args, from_tty)
     char *args;
     int from_tty;
{
  if (from_tty)
    {
      char *exec_file = get_exec_file (0);
      if (exec_file == 0)
	exec_file = "";
      printf_unfiltered ("Detaching from program: %s %s\n", exec_file,
			 target_pid_to_str (inferior_pid));
      gdb_flush (gdb_stdout);
    }
  inferior_pid = 0;
  unpush_target (&child_ops);
}

/* Print status information about what we're accessing.  */

static void
child_files_info (ignore)
     struct target_ops *ignore;
{
  printf_unfiltered ("\tUsing the running image of %s %s.\n",
      attach_flag ? "attached" : "child", target_pid_to_str (inferior_pid));
}

/* ARGSUSED */
static void
child_open (arg, from_tty)
     char *arg;
     int from_tty;
{
  error ("Use the \"run\" command to start a Unix child process.");
}

/* Start an inferior win32 child process and sets inferior_pid to its pid.
   EXEC_FILE is the file to run.
   ALLARGS is a string containing the arguments to the program.
   ENV is the environment vector to pass.  Errors reported with error().  */

static void
child_create_inferior (exec_file, allargs, env)
     char *exec_file;
     char *allargs;
     char **env;
{
  char real_path[MAXPATHLEN];
  char *winenv;
  char *temp;
  int envlen;
  int i;

  STARTUPINFO si;
  PROCESS_INFORMATION pi;
  struct target_waitstatus dummy;
  BOOL ret;
  DWORD flags;
  char *args;

  if (!exec_file)
    {
      error ("No executable specified, use `target exec'.\n");
    }

  memset (&si, 0, sizeof (si));
  si.cb = sizeof (si);

  cygwin32_conv_to_win32_path (exec_file, real_path);

  flags = DEBUG_ONLY_THIS_PROCESS;

  if (new_group)
    flags |= CREATE_NEW_PROCESS_GROUP;

  if (new_console)
    flags |= CREATE_NEW_CONSOLE;

  args = alloca (strlen (real_path) + strlen (allargs) + 2);

  strcpy (args, real_path);

  strcat (args, " ");
  strcat (args, allargs);

  /* Prepare the environment vars for CreateProcess.  */
  {
    /* This code use to assume all env vars were file names and would
       translate them all to win32 style.  That obviously doesn't work in the
       general case.  The current rule is that we only translate PATH.
       We need to handle PATH because we're about to call CreateProcess and
       it uses PATH to find DLL's.  Fortunately PATH has a well-defined value
       in both posix and win32 environments.  cygwin.dll will change it back
       to posix style if necessary.  */

    static const char *conv_path_names[] =
    {
      "PATH=",
      0
    };

    /* CreateProcess takes the environment list as a null terminated set of
       strings (i.e. two nulls terminate the list).  */

    /* Get total size for env strings.  */
    for (envlen = 0, i = 0; env[i] && *env[i]; i++)
      {
	int j, len;

	for (j = 0; conv_path_names[j]; j++)
	  {
	    len = strlen (conv_path_names[j]);
	    if (strncmp (conv_path_names[j], env[i], len) == 0)
	      {
		if (cygwin32_posix_path_list_p (env[i] + len))
		  envlen += len
		    + cygwin32_posix_to_win32_path_list_buf_size (env[i] + len);
		else
		  envlen += strlen (env[i]) + 1;
		break;
	      }
	  }
	if (conv_path_names[j] == NULL)
	  envlen += strlen (env[i]) + 1;
      }

    winenv = alloca (envlen + 1);

    /* Copy env strings into new buffer.  */
    for (temp = winenv, i = 0; env[i] && *env[i]; i++)
      {
	int j, len;

	for (j = 0; conv_path_names[j]; j++)
	  {
	    len = strlen (conv_path_names[j]);
	    if (strncmp (conv_path_names[j], env[i], len) == 0)
	      {
		if (cygwin32_posix_path_list_p (env[i] + len))
		  {
		    memcpy (temp, env[i], len);
		    cygwin32_posix_to_win32_path_list (env[i] + len, temp + len);
		  }
		else
		  strcpy (temp, env[i]);
		break;
	      }
	  }
	if (conv_path_names[j] == NULL)
	  strcpy (temp, env[i]);

	temp += strlen (temp) + 1;
      }

    /* Final nil string to terminate new env.  */
    *temp = 0;
  }

  ret = CreateProcess (0,
		       args,	/* command line */
		       NULL,	/* Security */
		       NULL,	/* thread */
		       TRUE,	/* inherit handles */
		       flags,	/* start flags */
		       winenv,
		       NULL,	/* current directory */
		       &si,
		       &pi);
  if (!ret)
    error ("Error creating process %s, (error %d)\n", exec_file, GetLastError ());

  exception_count = 0;
  event_count = 0;

  current_process_handle = pi.hProcess;
  current_event.dwProcessId = pi.dwProcessId;
  memset (&current_event, 0, sizeof (current_event));
  inferior_pid = current_event.dwThreadId = pi.dwThreadId;
  push_target (&child_ops);
  child_init_thread_list ();
  init_wait_for_inferior ();
  clear_proceed_status ();
  target_terminal_init ();
  target_terminal_inferior ();

  /* Ignore the first trap */
  child_wait (inferior_pid, &dummy);

  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
}

static void
child_mourn_inferior ()
{
  (void) child_continue (DBG_CONTINUE, -1);
  unpush_target (&child_ops);
  generic_mourn_inferior ();
}

/* Send a SIGINT to the process group.  This acts just like the user typed a
   ^C on the controlling terminal. */

static void
child_stop ()
{
  DEBUG_EVENTS (("gdb: GenerateConsoleCtrlEvent (CTRLC_EVENT, 0)\n"));
  CHECK (GenerateConsoleCtrlEvent (CTRL_C_EVENT, 0));
  registers_changed ();		/* refresh register state */
}

int
child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
		   int write, struct target_ops *target)
{
  DWORD done;
  if (write)
    {
      DEBUG_MEM (("gdb: write target memory, %d bytes at 0x%08x\n",
		  len, memaddr));
      WriteProcessMemory (current_process_handle, (LPVOID) memaddr, our,
			  len, &done);
      FlushInstructionCache (current_process_handle, (LPCVOID) memaddr, len);
    }
  else
    {
      DEBUG_MEM (("gdb: read target memory, %d bytes at 0x%08x\n",
		  len, memaddr));
      ReadProcessMemory (current_process_handle, (LPCVOID) memaddr, our, len,
			 &done);
    }
  return done;
}

void
child_kill_inferior (void)
{
  CHECK (TerminateProcess (current_process_handle, 0));

  for (;;)
    {
      if (!child_continue (DBG_CONTINUE, -1))
	break;
      if (!WaitForDebugEvent (&current_event, INFINITE))
	break;
      if (current_event.dwDebugEventCode == EXIT_PROCESS_DEBUG_EVENT)
	break;
    }

  CHECK (CloseHandle (current_process_handle));

  /* this may fail in an attached process so don't check. */
  (void) CloseHandle (current_thread->h);
  target_mourn_inferior ();	/* or just child_mourn_inferior? */
}

void
child_resume (int pid, int step, enum target_signal sig)
{
  int i;
  thread_info *th;
  DWORD continue_status = last_sig > 0 && last_sig < NSIG ?
  DBG_EXCEPTION_NOT_HANDLED : DBG_CONTINUE;

  DEBUG_EXEC (("gdb: child_resume (pid=%d, step=%d, sig=%d);\n",
	       pid, step, sig));

  /* Get context for currently selected thread */
  th = thread_rec (current_event.dwThreadId, FALSE);
  if (step)
    {
#ifdef i386
      /* Single step by setting t bit */
      child_fetch_inferior_registers (PS_REGNUM);
      th->context.EFlags |= FLAG_TRACE_BIT;
#endif
    }

  if (th->context.ContextFlags)
    {
      CHECK (SetThreadContext (th->h, &th->context));
      th->context.ContextFlags = 0;
    }

  /* Allow continuing with the same signal that interrupted us.
     Otherwise complain. */
  if (sig && sig != last_sig)
    fprintf_unfiltered (gdb_stderr, "Can't send signals to the child.  signal %d\n", sig);

  last_sig = 0;
  child_continue (continue_status, pid);
}

static void
child_prepare_to_store ()
{
  /* Do nothing, since we can store individual regs */
}

static int
child_can_run ()
{
  return 1;
}

static void
child_close ()
{
  DEBUG_EVENTS (("gdb: child_close, inferior_pid=%d\n", inferior_pid));
}

struct target_ops child_ops;

static void
init_child_ops (void)
{
  child_ops.to_shortname = "child";
  child_ops.to_longname = "Win32 child process";
  child_ops.to_doc = "Win32 child process (started by the \"run\" command).";
  child_ops.to_open = child_open;
  child_ops.to_close = child_close;
  child_ops.to_attach = child_attach;
  child_ops.to_detach = child_detach;
  child_ops.to_resume = child_resume;
  child_ops.to_wait = child_wait;
  child_ops.to_fetch_registers = child_fetch_inferior_registers;
  child_ops.to_store_registers = child_store_inferior_registers;
  child_ops.to_prepare_to_store = child_prepare_to_store;
  child_ops.to_xfer_memory = child_xfer_memory;
  child_ops.to_files_info = child_files_info;
  child_ops.to_insert_breakpoint = memory_insert_breakpoint;
  child_ops.to_remove_breakpoint = memory_remove_breakpoint;
  child_ops.to_terminal_init = terminal_init_inferior;
  child_ops.to_terminal_inferior = terminal_inferior;
  child_ops.to_terminal_ours_for_output = terminal_ours_for_output;
  child_ops.to_terminal_ours = terminal_ours;
  child_ops.to_terminal_info = child_terminal_info;
  child_ops.to_kill = child_kill_inferior;
  child_ops.to_load = 0;
  child_ops.to_lookup_symbol = 0;
  child_ops.to_create_inferior = child_create_inferior;
  child_ops.to_mourn_inferior = child_mourn_inferior;
  child_ops.to_can_run = child_can_run;
  child_ops.to_notice_signals = 0;
  child_ops.to_thread_alive = win32_child_thread_alive;
  child_ops.to_stop = child_stop;
  child_ops.to_stratum = process_stratum;
  child_ops.DONT_USE = 0;
  child_ops.to_has_all_memory = 1;
  child_ops.to_has_memory = 1;
  child_ops.to_has_stack = 1;
  child_ops.to_has_registers = 1;
  child_ops.to_has_execution = 1;
  child_ops.to_sections = 0;
  child_ops.to_sections_end = 0;
  child_ops.to_magic = OPS_MAGIC;
}

void
_initialize_inftarg ()
{
  struct cmd_list_element *c;
  init_child_ops ();

  add_show_from_set
    (add_set_cmd ("new-console", class_support, var_boolean,
		  (char *) &new_console,
		  "Set creation of new console when creating child process.",
		  &setlist),
     &showlist);

  add_show_from_set
    (add_set_cmd ("new-group", class_support, var_boolean,
		  (char *) &new_group,
		  "Set creation of new group when creating child process.",
		  &setlist),
     &showlist);

  add_show_from_set
    (add_set_cmd ("debugexec", class_support, var_boolean,
		  (char *) &debug_exec,
		  "Set whether to display execution in child process.",
		  &setlist),
     &showlist);

  add_show_from_set
    (add_set_cmd ("debugevents", class_support, var_boolean,
		  (char *) &debug_events,
		  "Set whether to display kernel events in child process.",
		  &setlist),
     &showlist);

  add_show_from_set
    (add_set_cmd ("debugmemory", class_support, var_boolean,
		  (char *) &debug_memory,
		  "Set whether to display memory accesses in child process.",
		  &setlist),
     &showlist);

  add_show_from_set
    (add_set_cmd ("debugexceptions", class_support, var_boolean,
		  (char *) &debug_exceptions,
	       "Set whether to display kernel exceptions in child process.",
		  &setlist),
     &showlist);

  add_target (&child_ops);
}

/* Determine if the thread referenced by "pid" is alive
   by "polling" it.  If WaitForSingleObject returns WAIT_OBJECT_0
   it means that the pid has died.  Otherwise it is assumed to be alive. */
static int
win32_child_thread_alive (int pid)
{
  return WaitForSingleObject (thread_rec (pid, FALSE)->h, 0) == WAIT_OBJECT_0 ?
    FALSE : TRUE;
}

/* Convert pid to printable format. */
char *
cygwin_pid_to_str (int pid)
{
  static char buf[80];
  if (pid == current_event.dwProcessId)
    sprintf (buf, "process %d", pid);
  else
    sprintf (buf, "thread %d.0x%x", current_event.dwProcessId, pid);
  return buf;
}