gdb/gdbserver/win32-low.c

   1 /* Low level interface to Windows debugging, for gdbserver.
   2    Copyright (C) 2006, 2007 Free Software Foundation, Inc.
   3
   4    Contributed by Leo Zayas.  Based on "win32-nat.c" from GDB.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "server.h"
  24 #include "regcache.h"
  25 #include "gdb/signals.h"
  26
  27 #include <windows.h>
  28 #include <imagehlp.h>
  29 #include <psapi.h>
  30 #include <sys/param.h>
  31 #include <malloc.h>
  32 #include <process.h>
  33
  34 #ifndef USE_WIN32API
  35 #include <sys/cygwin.h>
  36 #endif
  37
  38 #define LOG 0
  39
  40 #define OUTMSG(X) do { printf X; fflush (stdout); } while (0)
  41 #if LOG
  42 #define OUTMSG2(X) do { printf X; fflush (stdout); } while (0)
  43 #else
  44 #define OUTMSG2(X)
  45 #endif
  46
  47 int using_threads = 1;
  48
  49 /* Globals.  */
  50 static HANDLE current_process_handle = NULL;
  51 static DWORD current_process_id = 0;
  52 static enum target_signal last_sig = TARGET_SIGNAL_0;
  53
  54 /* The current debug event from WaitForDebugEvent.  */
  55 static DEBUG_EVENT current_event;
  56
  57 static int debug_registers_changed = 0;
  58 static int debug_registers_used = 0;
  59 static unsigned dr[8];
  60
  61 typedef BOOL winapi_DebugActiveProcessStop (DWORD dwProcessId);
  62 typedef BOOL winapi_DebugSetProcessKillOnExit (BOOL KillOnExit);
  63
  64 #define FLAG_TRACE_BIT 0x100
  65 #define CONTEXT_DEBUGGER (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
  66 #define CONTEXT_DEBUGGER_DR CONTEXT_DEBUGGER | CONTEXT_DEBUG_REGISTERS  \
  67   | CONTEXT_EXTENDED_REGISTERS
  68
  69 /* Thread information structure used to track extra information about
  70    each thread.  */
  71 typedef struct thread_info_struct
  72 {
  73   DWORD tid;
  74   HANDLE h;
  75   int suspend_count;
  76   CONTEXT context;
  77 } thread_info;
  78 static DWORD main_thread_id = 0;
  79
  80 /* Get the thread ID from the current selected inferior (the current
  81    thread).  */
  82 static DWORD
  83 current_inferior_tid (void)
  84 {
  85   thread_info *th = inferior_target_data (current_inferior);
  86   return th->tid;
  87 }
  88
  89 /* Find a thread record given a thread id.  If GET_CONTEXT is set then
  90    also retrieve the context for this thread.  */
  91 static thread_info *
  92 thread_rec (DWORD id, int get_context)
  93 {
  94   struct thread_info *thread;
  95   thread_info *th;
  96
  97   thread = (struct thread_info *) find_inferior_id (&all_threads, id);
  98   if (thread == NULL)
  99     return NULL;
 100
 101   th = inferior_target_data (thread);
 102   if (!th->suspend_count && get_context)
 103     {
 104       if (get_context > 0 && id != current_event.dwThreadId)
 105         th->suspend_count = SuspendThread (th->h) + 1;
 106       else if (get_context < 0)
 107         th->suspend_count = -1;
 108
 109       th->context.ContextFlags = CONTEXT_DEBUGGER_DR;
 110
 111       GetThreadContext (th->h, &th->context);
 112
 113       if (id == current_event.dwThreadId)
 114         {
 115           /* Copy dr values from that thread.  */
 116           dr[0] = th->context.Dr0;
 117           dr[1] = th->context.Dr1;
 118           dr[2] = th->context.Dr2;
 119           dr[3] = th->context.Dr3;
 120           dr[6] = th->context.Dr6;
 121           dr[7] = th->context.Dr7;
 122         }
 123     }
 124
 125   return th;
 126 }
 127
 128 /* Add a thread to the thread list.  */
 129 static thread_info *
 130 child_add_thread (DWORD tid, HANDLE h)
 131 {
 132   thread_info *th;
 133
 134   if ((th = thread_rec (tid, FALSE)))
 135     return th;
 136
 137   th = (thread_info *) malloc (sizeof (*th));
 138   memset (th, 0, sizeof (*th));
 139   th->tid = tid;
 140   th->h = h;
 141
 142   add_thread (tid, th, (unsigned int) tid);
 143   set_inferior_regcache_data ((struct thread_info *)
 144                               find_inferior_id (&all_threads, tid),
 145                               new_register_cache ());
 146
 147   /* Set the debug registers for the new thread if they are used.  */
 148   if (debug_registers_used)
 149     {
 150       /* Only change the value of the debug registers.  */
 151       th->context.ContextFlags = CONTEXT_DEBUGGER_DR;
 152
 153       GetThreadContext (th->h, &th->context);
 154
 155       th->context.Dr0 = dr[0];
 156       th->context.Dr1 = dr[1];
 157       th->context.Dr2 = dr[2];
 158       th->context.Dr3 = dr[3];
 159       /* th->context.Dr6 = dr[6];
 160          FIXME: should we set dr6 also ?? */
 161       th->context.Dr7 = dr[7];
 162       SetThreadContext (th->h, &th->context);
 163       th->context.ContextFlags = 0;
 164     }
 165
 166   return th;
 167 }
 168
 169 /* Delete a thread from the list of threads.  */
 170 static void
 171 delete_thread_info (struct inferior_list_entry *thread)
 172 {
 173   thread_info *th = inferior_target_data ((struct thread_info *) thread);
 174
 175   remove_thread ((struct thread_info *) thread);
 176   CloseHandle (th->h);
 177   free (th);
 178 }
 179
 180 /* Delete a thread from the list of threads.  */
 181 static void
 182 child_delete_thread (DWORD id)
 183 {
 184   struct inferior_list_entry *thread;
 185
 186   /* If the last thread is exiting, just return.  */
 187   if (all_threads.head == all_threads.tail)
 188     return;
 189
 190   thread = find_inferior_id (&all_threads, id);
 191   if (thread == NULL)
 192     return;
 193
 194   delete_thread_info (thread);
 195 }
 196
 197 /* Transfer memory from/to the debugged process.  */
 198 static int
 199 child_xfer_memory (CORE_ADDR memaddr, char *our, int len,
 200                    int write, struct target_ops *target)
 201 {
 202   SIZE_T done;
 203   long addr = (long) memaddr;
 204
 205   if (write)
 206     {
 207       WriteProcessMemory (current_process_handle, (LPVOID) addr,
 208                           (LPCVOID) our, len, &done);
 209       FlushInstructionCache (current_process_handle, (LPCVOID) addr, len);
 210     }
 211   else
 212     {
 213       ReadProcessMemory (current_process_handle, (LPCVOID) addr, (LPVOID) our,
 214                          len, &done);
 215     }
 216   return done;
 217 }
 218
 219 /* Generally, what has the program done?  */
 220 enum target_waitkind
 221 {
 222   /* The program has exited.  The exit status is in value.integer.  */
 223   TARGET_WAITKIND_EXITED,
 224
 225   /* The program has stopped with a signal.  Which signal is in
 226      value.sig.  */
 227   TARGET_WAITKIND_STOPPED,
 228
 229   /* The program is letting us know that it dynamically loaded something
 230      (e.g. it called load(2) on AIX).  */
 231   TARGET_WAITKIND_LOADED,
 232
 233   /* The program has exec'ed a new executable file.  The new file's
 234      pathname is pointed to by value.execd_pathname.  */
 235
 236   TARGET_WAITKIND_EXECD,
 237
 238   /* Nothing happened, but we stopped anyway.  This perhaps should be handled
 239      within target_wait, but I'm not sure target_wait should be resuming the
 240      inferior.  */
 241   TARGET_WAITKIND_SPURIOUS,
 242 };
 243
 244 struct target_waitstatus
 245 {
 246   enum target_waitkind kind;
 247
 248   /* Forked child pid, execd pathname, exit status or signal number.  */
 249   union
 250   {
 251     int integer;
 252     enum target_signal sig;
 253     int related_pid;
 254     char *execd_pathname;
 255     int syscall_id;
 256   }
 257   value;
 258 };
 259
 260 #define NUM_REGS 41
 261 #define FCS_REGNUM 27
 262 #define FOP_REGNUM 31
 263
 264 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 265 static const int mappings[] = {
 266   context_offset (Eax),
 267   context_offset (Ecx),
 268   context_offset (Edx),
 269   context_offset (Ebx),
 270   context_offset (Esp),
 271   context_offset (Ebp),
 272   context_offset (Esi),
 273   context_offset (Edi),
 274   context_offset (Eip),
 275   context_offset (EFlags),
 276   context_offset (SegCs),
 277   context_offset (SegSs),
 278   context_offset (SegDs),
 279   context_offset (SegEs),
 280   context_offset (SegFs),
 281   context_offset (SegGs),
 282   context_offset (FloatSave.RegisterArea[0 * 10]),
 283   context_offset (FloatSave.RegisterArea[1 * 10]),
 284   context_offset (FloatSave.RegisterArea[2 * 10]),
 285   context_offset (FloatSave.RegisterArea[3 * 10]),
 286   context_offset (FloatSave.RegisterArea[4 * 10]),
 287   context_offset (FloatSave.RegisterArea[5 * 10]),
 288   context_offset (FloatSave.RegisterArea[6 * 10]),
 289   context_offset (FloatSave.RegisterArea[7 * 10]),
 290   context_offset (FloatSave.ControlWord),
 291   context_offset (FloatSave.StatusWord),
 292   context_offset (FloatSave.TagWord),
 293   context_offset (FloatSave.ErrorSelector),
 294   context_offset (FloatSave.ErrorOffset),
 295   context_offset (FloatSave.DataSelector),
 296   context_offset (FloatSave.DataOffset),
 297   context_offset (FloatSave.ErrorSelector),
 298   /* XMM0-7 */
 299   context_offset (ExtendedRegisters[10 * 16]),
 300   context_offset (ExtendedRegisters[11 * 16]),
 301   context_offset (ExtendedRegisters[12 * 16]),
 302   context_offset (ExtendedRegisters[13 * 16]),
 303   context_offset (ExtendedRegisters[14 * 16]),
 304   context_offset (ExtendedRegisters[15 * 16]),
 305   context_offset (ExtendedRegisters[16 * 16]),
 306   context_offset (ExtendedRegisters[17 * 16]),
 307   /* MXCSR */
 308   context_offset (ExtendedRegisters[24])
 309 };
 310
 311 #undef context_offset
 312
 313 /* Clear out any old thread list and reintialize it to a pristine
 314    state. */
 315 static void
 316 child_init_thread_list (void)
 317 {
 318   for_each_inferior (&all_threads, delete_thread_info);
 319 }
 320
 321 static void
 322 do_initial_child_stuff (DWORD pid)
 323 {
 324   int i;
 325
 326   last_sig = TARGET_SIGNAL_0;
 327
 328   debug_registers_changed = 0;
 329   debug_registers_used = 0;
 330   for (i = 0; i < sizeof (dr) / sizeof (dr[0]); i++)
 331     dr[i] = 0;
 332   memset (&current_event, 0, sizeof (current_event));
 333
 334   child_init_thread_list ();
 335 }
 336
 337 /* Resume all artificially suspended threads if we are continuing
 338    execution.  */
 339 static int
 340 continue_one_thread (struct inferior_list_entry *this_thread, void *id_ptr)
 341 {
 342   struct thread_info *thread = (struct thread_info *) this_thread;
 343   int thread_id = * (int *) id_ptr;
 344   thread_info *th = inferior_target_data (thread);
 345   int i;
 346
 347   if ((thread_id == -1 || thread_id == th->tid)
 348       && th->suspend_count)
 349     {
 350       for (i = 0; i < th->suspend_count; i++)
 351         (void) ResumeThread (th->h);
 352       th->suspend_count = 0;
 353       if (debug_registers_changed)
 354         {
 355           /* Only change the value of the debug registers.  */
 356           th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 357           th->context.Dr0 = dr[0];
 358           th->context.Dr1 = dr[1];
 359           th->context.Dr2 = dr[2];
 360           th->context.Dr3 = dr[3];
 361           /* th->context.Dr6 = dr[6];
 362              FIXME: should we set dr6 also ?? */
 363           th->context.Dr7 = dr[7];
 364           SetThreadContext (th->h, &th->context);
 365           th->context.ContextFlags = 0;
 366         }
 367     }
 368
 369   return 0;
 370 }
 371
 372 static BOOL
 373 child_continue (DWORD continue_status, int thread_id)
 374 {
 375   BOOL res;
 376
 377   res = ContinueDebugEvent (current_event.dwProcessId,
 378                             current_event.dwThreadId, continue_status);
 379   continue_status = 0;
 380   if (res)
 381     find_inferior (&all_threads, continue_one_thread, &thread_id);
 382
 383   debug_registers_changed = 0;
 384   return res;
 385 }
 386
 387 /* Fetch register(s) from gdbserver regcache data.  */
 388 static void
 389 do_child_fetch_inferior_registers (thread_info *th, int r)
 390 {
 391   char *context_offset = ((char *) &th->context) + mappings[r];
 392   long l;
 393   if (r == FCS_REGNUM)
 394     {
 395       l = *((long *) context_offset) & 0xffff;
 396       supply_register (r, (char *) &l);
 397     }
 398   else if (r == FOP_REGNUM)
 399     {
 400       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 401       supply_register (r, (char *) &l);
 402     }
 403   else
 404     supply_register (r, context_offset);
 405 }
 406
 407 /* Fetch register(s) from the current thread context.  */
 408 static void
 409 child_fetch_inferior_registers (int r)
 410 {
 411   int regno;
 412   thread_info *th = thread_rec (current_inferior_tid (), TRUE);
 413   if (r == -1 || r == 0 || r > NUM_REGS)
 414     child_fetch_inferior_registers (NUM_REGS);
 415   else
 416     for (regno = 0; regno < r; regno++)
 417       do_child_fetch_inferior_registers (th, regno);
 418 }
 419
 420 /* Get register from gdbserver regcache data.  */
 421 static void
 422 do_child_store_inferior_registers (thread_info *th, int r)
 423 {
 424   collect_register (r, ((char *) &th->context) + mappings[r]);
 425 }
 426
 427 /* Store a new register value into the current thread context.  We don't
 428    change the program's context until later, when we resume it.  */
 429 static void
 430 child_store_inferior_registers (int r)
 431 {
 432   int regno;
 433   thread_info *th = thread_rec (current_inferior_tid (), TRUE);
 434   if (r == -1 || r == 0 || r > NUM_REGS)
 435     child_store_inferior_registers (NUM_REGS);
 436   else
 437     for (regno = 0; regno < r; regno++)
 438       do_child_store_inferior_registers (th, regno);
 439 }
 440
 441 /* Start a new process.
 442    PROGRAM is a path to the program to execute.
 443    ARGS is a standard NULL-terminated array of arguments,
 444    to be passed to the inferior as ``argv''.
 445    Returns the new PID on success, -1 on failure.  Registers the new
 446    process with the process list.  */
 447 static int
 448 win32_create_inferior (char *program, char **program_args)
 449 {
 450 #ifndef USE_WIN32API
 451   char real_path[MAXPATHLEN];
 452   char *orig_path, *new_path, *path_ptr;
 453 #endif
 454   char *winenv = NULL;
 455   STARTUPINFO si;
 456   PROCESS_INFORMATION pi;
 457   BOOL ret;
 458   DWORD flags;
 459   char *args;
 460   int argslen;
 461   int argc;
 462
 463   if (!program)
 464     error ("No executable specified, specify executable to debug.\n");
 465
 466   memset (&si, 0, sizeof (si));
 467   si.cb = sizeof (si);
 468
 469   flags = DEBUG_PROCESS | DEBUG_ONLY_THIS_PROCESS;
 470
 471 #ifndef USE_WIN32API
 472   orig_path = NULL;
 473   path_ptr = getenv ("PATH");
 474   if (path_ptr)
 475     {
 476       orig_path = alloca (strlen (path_ptr) + 1);
 477       new_path = alloca (cygwin_posix_to_win32_path_list_buf_size (path_ptr));
 478       strcpy (orig_path, path_ptr);
 479       cygwin_posix_to_win32_path_list (path_ptr, new_path);
 480       setenv ("PATH", new_path, 1);
 481     }
 482   cygwin_conv_to_win32_path (program, real_path);
 483   program = real_path;
 484 #endif
 485
 486   argslen = strlen (program) + 1;
 487   for (argc = 1; program_args[argc]; argc++)
 488     argslen += strlen (program_args[argc]) + 1;
 489   args = alloca (argslen);
 490   strcpy (args, program);
 491   for (argc = 1; program_args[argc]; argc++)
 492     {
 493       /* FIXME: Can we do better about quoting?  How does Cygwin
 494          handle this?  */
 495       strcat (args, " ");
 496       strcat (args, program_args[argc]);
 497     }
 498   OUTMSG2 (("Command line is %s\n", args));
 499
 500   flags |= CREATE_NEW_PROCESS_GROUP;
 501
 502   ret = CreateProcess (0, args, /* command line */
 503                        NULL,    /* Security */
 504                        NULL,    /* thread */
 505                        TRUE,    /* inherit handles */
 506                        flags,   /* start flags */
 507                        winenv, NULL,    /* current directory */
 508                        &si, &pi);
 509
 510 #ifndef USE_WIN32API
 511   if (orig_path)
 512     setenv ("PATH", orig_path, 1);
 513 #endif
 514
 515   if (!ret)
 516     {
 517       error ("Error creating process %s, (error %d): %s\n", args,
 518              (int) GetLastError (), strerror (GetLastError ()));
 519     }
 520   else
 521     {
 522       OUTMSG2 (("Process created: %s\n", (char *) args));
 523     }
 524
 525   CloseHandle (pi.hThread);
 526
 527   current_process_handle = pi.hProcess;
 528   current_process_id = pi.dwProcessId;
 529
 530   do_initial_child_stuff (current_process_id);
 531
 532   return current_process_id;
 533 }
 534
 535 /* Attach to a running process.
 536    PID is the process ID to attach to, specified by the user
 537    or a higher layer.  */
 538 static int
 539 win32_attach (unsigned long pid)
 540 {
 541   int res = 0;
 542   HMODULE kernel32 = LoadLibrary ("KERNEL32.DLL");
 543   winapi_DebugActiveProcessStop *DebugActiveProcessStop = NULL;
 544   winapi_DebugSetProcessKillOnExit *DebugSetProcessKillOnExit = NULL;
 545
 546   DebugActiveProcessStop =
 547     (winapi_DebugActiveProcessStop *) GetProcAddress (kernel32,
 548                                                       "DebugActiveProcessStop");
 549   DebugSetProcessKillOnExit =
 550     (winapi_DebugSetProcessKillOnExit *) GetProcAddress (kernel32,
 551                                                          "DebugSetProcessKillOnExit");
 552
 553   res = DebugActiveProcess (pid) ? 1 : 0;
 554
 555   if (!res)
 556     error ("Attach to process failed.");
 557
 558   if (DebugSetProcessKillOnExit != NULL)
 559     DebugSetProcessKillOnExit (FALSE);
 560
 561   current_process_id = pid;
 562   current_process_handle = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pid);
 563
 564   if (current_process_handle == NULL)
 565     {
 566       res = 0;
 567       if (DebugActiveProcessStop != NULL)
 568         DebugActiveProcessStop (current_process_id);
 569     }
 570
 571   if (res)
 572     do_initial_child_stuff (pid);
 573
 574   FreeLibrary (kernel32);
 575
 576   return res;
 577 }
 578
 579 /* Handle OUTPUT_DEBUG_STRING_EVENT from child process.  */
 580 static void
 581 handle_output_debug_string (struct target_waitstatus *ourstatus)
 582 {
 583 #define READ_BUFFER_LEN 1024
 584   CORE_ADDR addr;
 585   char s[READ_BUFFER_LEN + 1] = { 0 };
 586   DWORD nbytes = current_event.u.DebugString.nDebugStringLength;
 587
 588   if (nbytes == 0)
 589     return;
 590
 591   if (nbytes > READ_BUFFER_LEN)
 592     nbytes = READ_BUFFER_LEN;
 593
 594   addr = (CORE_ADDR) (size_t) current_event.u.DebugString.lpDebugStringData;
 595
 596   if (current_event.u.DebugString.fUnicode)
 597     {
 598       /* The event tells us how many bytes, not chars, even
 599          in Unicode.  */
 600       WCHAR buffer[(READ_BUFFER_LEN + 1) / sizeof (WCHAR)] = { 0 };
 601       if (read_inferior_memory (addr, (unsigned char *) buffer, nbytes) != 0)
 602         return;
 603       wcstombs (s, buffer, (nbytes + 1) / sizeof (WCHAR));
 604     }
 605   else
 606     {
 607       if (read_inferior_memory (addr, (unsigned char *) s, nbytes) != 0)
 608         return;
 609     }
 610
 611   if (strncmp (s, "cYg", 3) != 0)
 612     monitor_output (s);
 613 #undef READ_BUFFER_LEN
 614 }
 615
 616 /* Kill all inferiors.  */
 617 static void
 618 win32_kill (void)
 619 {
 620   if (current_process_handle == NULL)
 621     return;
 622
 623   TerminateProcess (current_process_handle, 0);
 624   for (;;)
 625     {
 626       if (!child_continue (DBG_CONTINUE, -1))
 627         break;
 628       if (!WaitForDebugEvent (&current_event, INFINITE))
 629         break;
 630       if (current_event.dwDebugEventCode == EXIT_PROCESS_DEBUG_EVENT)
 631         break;
 632       else if (current_event.dwDebugEventCode == OUTPUT_DEBUG_STRING_EVENT)
 633         {
 634           struct target_waitstatus our_status = { 0 };
 635           handle_output_debug_string (&our_status);
 636         }
 637     }
 638 }
 639
 640 /* Detach from all inferiors.  */
 641 static void
 642 win32_detach (void)
 643 {
 644   HMODULE kernel32 = LoadLibrary ("KERNEL32.DLL");
 645   winapi_DebugActiveProcessStop *DebugActiveProcessStop = NULL;
 646   winapi_DebugSetProcessKillOnExit *DebugSetProcessKillOnExit = NULL;
 647
 648   DebugActiveProcessStop =
 649     (winapi_DebugActiveProcessStop *) GetProcAddress (kernel32,
 650                                                       "DebugActiveProcessStop");
 651   DebugSetProcessKillOnExit =
 652     (winapi_DebugSetProcessKillOnExit *) GetProcAddress (kernel32,
 653                                                          "DebugSetProcessKillOnExit");
 654
 655   if (DebugSetProcessKillOnExit != NULL)
 656     DebugSetProcessKillOnExit (FALSE);
 657
 658   if (DebugActiveProcessStop != NULL)
 659     DebugActiveProcessStop (current_process_id);
 660   else
 661     win32_kill ();
 662
 663   FreeLibrary (kernel32);
 664 }
 665
 666 /* Return 1 iff the thread with thread ID TID is alive.  */
 667 static int
 668 win32_thread_alive (unsigned long tid)
 669 {
 670   int res;
 671
 672   /* Our thread list is reliable; don't bother to poll target
 673      threads.  */
 674   if (find_inferior_id (&all_threads, tid) != NULL)
 675     res = 1;
 676   else
 677     res = 0;
 678   return res;
 679 }
 680
 681 /* Resume the inferior process.  RESUME_INFO describes how we want
 682    to resume.  */
 683 static void
 684 win32_resume (struct thread_resume *resume_info)
 685 {
 686   DWORD tid;
 687   enum target_signal sig;
 688   int step;
 689   thread_info *th;
 690   DWORD continue_status = DBG_CONTINUE;
 691
 692   /* This handles the very limited set of resume packets that GDB can
 693      currently produce.  */
 694
 695   if (resume_info[0].thread == -1)
 696     tid = -1;
 697   else if (resume_info[1].thread == -1 && !resume_info[1].leave_stopped)
 698     tid = -1;
 699   else
 700     /* Yes, we're ignoring resume_info[0].thread.  It'd be tricky to make
 701        the Windows resume code do the right thing for thread switching.  */
 702     tid = current_event.dwThreadId;
 703
 704   if (resume_info[0].thread != -1)
 705     {
 706       sig = resume_info[0].sig;
 707       step = resume_info[0].step;
 708     }
 709   else
 710     {
 711       sig = 0;
 712       step = 0;
 713     }
 714
 715   if (sig != TARGET_SIGNAL_0)
 716     {
 717       if (current_event.dwDebugEventCode != EXCEPTION_DEBUG_EVENT)
 718         {
 719           OUTMSG (("Cannot continue with signal %d here.\n", sig));
 720         }
 721       else if (sig == last_sig)
 722         continue_status = DBG_EXCEPTION_NOT_HANDLED;
 723       else
 724         OUTMSG (("Can only continue with recieved signal %d.\n", last_sig));
 725     }
 726
 727   last_sig = TARGET_SIGNAL_0;
 728
 729   /* Get context for the currently selected thread.  */
 730   th = thread_rec (current_event.dwThreadId, FALSE);
 731   if (th)
 732     {
 733       if (th->context.ContextFlags)
 734         {
 735           if (debug_registers_changed)
 736             {
 737               th->context.Dr0 = dr[0];
 738               th->context.Dr1 = dr[1];
 739               th->context.Dr2 = dr[2];
 740               th->context.Dr3 = dr[3];
 741               /* th->context.Dr6 = dr[6];
 742                  FIXME: should we set dr6 also ?? */
 743               th->context.Dr7 = dr[7];
 744             }
 745
 746           /* Move register values from the inferior into the thread
 747              context structure.  */
 748           regcache_invalidate ();
 749
 750           if (step)
 751             th->context.EFlags |= FLAG_TRACE_BIT;
 752
 753           SetThreadContext (th->h, &th->context);
 754           th->context.ContextFlags = 0;
 755         }
 756     }
 757
 758   /* Allow continuing with the same signal that interrupted us.
 759      Otherwise complain.  */
 760
 761   child_continue (continue_status, tid);
 762 }
 763
 764 static int
 765 handle_exception (struct target_waitstatus *ourstatus)
 766 {
 767   thread_info *th;
 768   DWORD code = current_event.u.Exception.ExceptionRecord.ExceptionCode;
 769
 770   ourstatus->kind = TARGET_WAITKIND_STOPPED;
 771
 772   /* Record the context of the current thread.  */
 773   th = thread_rec (current_event.dwThreadId, -1);
 774
 775   switch (code)
 776     {
 777     case EXCEPTION_ACCESS_VIOLATION:
 778       OUTMSG2 (("EXCEPTION_ACCESS_VIOLATION"));
 779       ourstatus->value.sig = TARGET_SIGNAL_SEGV;
 780       break;
 781     case STATUS_STACK_OVERFLOW:
 782       OUTMSG2 (("STATUS_STACK_OVERFLOW"));
 783       ourstatus->value.sig = TARGET_SIGNAL_SEGV;
 784       break;
 785     case STATUS_FLOAT_DENORMAL_OPERAND:
 786       OUTMSG2 (("STATUS_FLOAT_DENORMAL_OPERAND"));
 787       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 788       break;
 789     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 790       OUTMSG2 (("EXCEPTION_ARRAY_BOUNDS_EXCEEDED"));
 791       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 792       break;
 793     case STATUS_FLOAT_INEXACT_RESULT:
 794       OUTMSG2 (("STATUS_FLOAT_INEXACT_RESULT"));
 795       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 796       break;
 797     case STATUS_FLOAT_INVALID_OPERATION:
 798       OUTMSG2 (("STATUS_FLOAT_INVALID_OPERATION"));
 799       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 800       break;
 801     case STATUS_FLOAT_OVERFLOW:
 802       OUTMSG2 (("STATUS_FLOAT_OVERFLOW"));
 803       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 804       break;
 805     case STATUS_FLOAT_STACK_CHECK:
 806       OUTMSG2 (("STATUS_FLOAT_STACK_CHECK"));
 807       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 808       break;
 809     case STATUS_FLOAT_UNDERFLOW:
 810       OUTMSG2 (("STATUS_FLOAT_UNDERFLOW"));
 811       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 812       break;
 813     case STATUS_FLOAT_DIVIDE_BY_ZERO:
 814       OUTMSG2 (("STATUS_FLOAT_DIVIDE_BY_ZERO"));
 815       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 816       break;
 817     case STATUS_INTEGER_DIVIDE_BY_ZERO:
 818       OUTMSG2 (("STATUS_INTEGER_DIVIDE_BY_ZERO"));
 819       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 820       break;
 821     case STATUS_INTEGER_OVERFLOW:
 822       OUTMSG2 (("STATUS_INTEGER_OVERFLOW"));
 823       ourstatus->value.sig = TARGET_SIGNAL_FPE;
 824       break;
 825     case EXCEPTION_BREAKPOINT:
 826       OUTMSG2 (("EXCEPTION_BREAKPOINT"));
 827       ourstatus->value.sig = TARGET_SIGNAL_TRAP;
 828       break;
 829     case DBG_CONTROL_C:
 830       OUTMSG2 (("DBG_CONTROL_C"));
 831       ourstatus->value.sig = TARGET_SIGNAL_INT;
 832       break;
 833     case DBG_CONTROL_BREAK:
 834       OUTMSG2 (("DBG_CONTROL_BREAK"));
 835       ourstatus->value.sig = TARGET_SIGNAL_INT;
 836       break;
 837     case EXCEPTION_SINGLE_STEP:
 838       OUTMSG2 (("EXCEPTION_SINGLE_STEP"));
 839       ourstatus->value.sig = TARGET_SIGNAL_TRAP;
 840       break;
 841     case EXCEPTION_ILLEGAL_INSTRUCTION:
 842       OUTMSG2 (("EXCEPTION_ILLEGAL_INSTRUCTION"));
 843       ourstatus->value.sig = TARGET_SIGNAL_ILL;
 844       break;
 845     case EXCEPTION_PRIV_INSTRUCTION:
 846       OUTMSG2 (("EXCEPTION_PRIV_INSTRUCTION"));
 847       ourstatus->value.sig = TARGET_SIGNAL_ILL;
 848       break;
 849     case EXCEPTION_NONCONTINUABLE_EXCEPTION:
 850       OUTMSG2 (("EXCEPTION_NONCONTINUABLE_EXCEPTION"));
 851       ourstatus->value.sig = TARGET_SIGNAL_ILL;
 852       break;
 853     default:
 854       if (current_event.u.Exception.dwFirstChance)
 855         return 0;
 856       OUTMSG2 (("gdbserver: unknown target exception 0x%08lx at 0x%08lx",
 857                 current_event.u.Exception.ExceptionRecord.ExceptionCode,
 858                 (DWORD) current_event.u.Exception.ExceptionRecord.
 859                 ExceptionAddress));
 860       ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
 861       break;
 862     }
 863   OUTMSG2 (("\n"));
 864   last_sig = ourstatus->value.sig;
 865   return 1;
 866 }
 867
 868 /* Get the next event from the child.  Return 1 if the event requires
 869    handling.  */
 870 static int
 871 get_child_debug_event (struct target_waitstatus *ourstatus)
 872 {
 873   BOOL debug_event;
 874   DWORD continue_status, event_code;
 875   thread_info *th = NULL;
 876   static thread_info dummy_thread_info;
 877   int retval = 0;
 878
 879 in:
 880
 881   last_sig = TARGET_SIGNAL_0;
 882   ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
 883
 884   if (!(debug_event = WaitForDebugEvent (&current_event, 1000)))
 885     goto out;
 886
 887   current_inferior =
 888     (struct thread_info *) find_inferior_id (&all_threads,
 889                                              current_event.dwThreadId);
 890
 891   continue_status = DBG_CONTINUE;
 892   event_code = current_event.dwDebugEventCode;
 893
 894   switch (event_code)
 895     {
 896     case CREATE_THREAD_DEBUG_EVENT:
 897       OUTMSG2 (("gdbserver: kernel event CREATE_THREAD_DEBUG_EVENT "
 898                 "for pid=%d tid=%x)\n",
 899                 (unsigned) current_event.dwProcessId,
 900                 (unsigned) current_event.dwThreadId));
 901
 902       /* Record the existence of this thread.  */
 903       th = child_add_thread (current_event.dwThreadId,
 904                              current_event.u.CreateThread.hThread);
 905
 906       retval = current_event.dwThreadId;
 907       break;
 908
 909     case EXIT_THREAD_DEBUG_EVENT:
 910       OUTMSG2 (("gdbserver: kernel event EXIT_THREAD_DEBUG_EVENT "
 911                 "for pid=%d tid=%x\n",
 912                 (unsigned) current_event.dwProcessId,
 913                 (unsigned) current_event.dwThreadId));
 914       child_delete_thread (current_event.dwThreadId);
 915       th = &dummy_thread_info;
 916       break;
 917
 918     case CREATE_PROCESS_DEBUG_EVENT:
 919       OUTMSG2 (("gdbserver: kernel event CREATE_PROCESS_DEBUG_EVENT "
 920                 "for pid=%d tid=%x\n",
 921                 (unsigned) current_event.dwProcessId,
 922                 (unsigned) current_event.dwThreadId));
 923       CloseHandle (current_event.u.CreateProcessInfo.hFile);
 924
 925       current_process_handle = current_event.u.CreateProcessInfo.hProcess;
 926       main_thread_id = current_event.dwThreadId;
 927
 928       ourstatus->kind = TARGET_WAITKIND_EXECD;
 929       ourstatus->value.execd_pathname = "Main executable";
 930
 931       /* Add the main thread.  */
 932       th =
 933         child_add_thread (main_thread_id,
 934                           current_event.u.CreateProcessInfo.hThread);
 935
 936       retval = ourstatus->value.related_pid = current_event.dwThreadId;
 937       break;
 938
 939     case EXIT_PROCESS_DEBUG_EVENT:
 940       OUTMSG2 (("gdbserver: kernel event EXIT_PROCESS_DEBUG_EVENT "
 941                 "for pid=%d tid=%x\n",
 942                 (unsigned) current_event.dwProcessId,
 943                 (unsigned) current_event.dwThreadId));
 944       ourstatus->kind = TARGET_WAITKIND_EXITED;
 945       ourstatus->value.integer = current_event.u.ExitProcess.dwExitCode;
 946       CloseHandle (current_process_handle);
 947       current_process_handle = NULL;
 948       retval = main_thread_id;
 949       break;
 950
 951     case LOAD_DLL_DEBUG_EVENT:
 952       OUTMSG2 (("gdbserver: kernel event LOAD_DLL_DEBUG_EVENT "
 953                 "for pid=%d tid=%x\n",
 954                 (unsigned) current_event.dwProcessId,
 955                 (unsigned) current_event.dwThreadId));
 956       CloseHandle (current_event.u.LoadDll.hFile);
 957
 958       ourstatus->kind = TARGET_WAITKIND_LOADED;
 959       ourstatus->value.integer = 0;
 960       retval = main_thread_id;
 961       break;
 962
 963     case UNLOAD_DLL_DEBUG_EVENT:
 964       OUTMSG2 (("gdbserver: kernel event UNLOAD_DLL_DEBUG_EVENT "
 965                 "for pid=%d tid=%x\n",
 966                 (unsigned) current_event.dwProcessId,
 967                 (unsigned) current_event.dwThreadId));
 968       break;
 969
 970     case EXCEPTION_DEBUG_EVENT:
 971       OUTMSG2 (("gdbserver: kernel event EXCEPTION_DEBUG_EVENT "
 972                 "for pid=%d tid=%x\n",
 973                 (unsigned) current_event.dwProcessId,
 974                 (unsigned) current_event.dwThreadId));
 975       retval = handle_exception (ourstatus);
 976       break;
 977
 978     case OUTPUT_DEBUG_STRING_EVENT:
 979       /* A message from the kernel (or Cygwin).  */
 980       OUTMSG2 (("gdbserver: kernel event OUTPUT_DEBUG_STRING_EVENT "
 981                 "for pid=%d tid=%x\n",
 982                 (unsigned) current_event.dwProcessId,
 983                 (unsigned) current_event.dwThreadId));
 984       handle_output_debug_string (ourstatus);
 985       break;
 986
 987     default:
 988       OUTMSG2 (("gdbserver: kernel event unknown "
 989                 "for pid=%d tid=%x code=%ld\n",
 990                 (unsigned) current_event.dwProcessId,
 991                 (unsigned) current_event.dwThreadId,
 992                 current_event.dwDebugEventCode));
 993       break;
 994     }
 995
 996   current_inferior =
 997     (struct thread_info *) find_inferior_id (&all_threads,
 998                                              current_event.dwThreadId);
 999
1000   if (!retval || (event_code != EXCEPTION_DEBUG_EVENT && event_code != EXIT_PROCESS_DEBUG_EVENT))
1001     {
1002       child_continue (continue_status, -1);
1003       goto in;
1004     }
1005
1006   if (th == NULL)
1007     thread_rec (current_event.dwThreadId, TRUE);
1008
1009 out:
1010   return retval;
1011 }
1012
1013 /* Wait for the inferior process to change state.
1014    STATUS will be filled in with a response code to send to GDB.
1015    Returns the signal which caused the process to stop. */
1016 static unsigned char
1017 win32_wait (char *status)
1018 {
1019   struct target_waitstatus our_status;
1020
1021   *status = 'T';
1022
1023   while (1)
1024     {
1025       get_child_debug_event (&our_status);
1026
1027       if (our_status.kind == TARGET_WAITKIND_EXITED)
1028         {
1029           OUTMSG2 (("Child exited with retcode = %x\n",
1030                     our_status.value.integer));
1031
1032           *status = 'W';
1033
1034           child_fetch_inferior_registers (-1);
1035
1036           return our_status.value.integer;
1037         }
1038       else if (our_status.kind == TARGET_WAITKIND_STOPPED)
1039         {
1040           OUTMSG2 (("Child Stopped with signal = %x \n",
1041                     WSTOPSIG (our_status.value.sig)));
1042
1043           *status = 'T';
1044
1045           child_fetch_inferior_registers (-1);
1046
1047           return our_status.value.sig;
1048         }
1049       else
1050         OUTMSG (("Ignoring unknown internal event, %d\n", our_status.kind));
1051
1052       {
1053         struct thread_resume resume;
1054         resume.thread = -1;
1055         resume.step = 0;
1056         resume.sig = 0;
1057         resume.leave_stopped = 0;
1058         win32_resume (&resume);
1059       }
1060     }
1061 }
1062
1063 /* Fetch registers from the inferior process.
1064    If REGNO is -1, fetch all registers; otherwise, fetch at least REGNO.  */
1065 static void
1066 win32_fetch_inferior_registers (int regno)
1067 {
1068   child_fetch_inferior_registers (regno);
1069 }
1070
1071 /* Store registers to the inferior process.
1072    If REGNO is -1, store all registers; otherwise, store at least REGNO.  */
1073 static void
1074 win32_store_inferior_registers (int regno)
1075 {
1076   child_store_inferior_registers (regno);
1077 }
1078
1079 /* Read memory from the inferior process.  This should generally be
1080    called through read_inferior_memory, which handles breakpoint shadowing.
1081    Read LEN bytes at MEMADDR into a buffer at MYADDR.  */
1082 static int
1083 win32_read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len)
1084 {
1085   return child_xfer_memory (memaddr, myaddr, len, 0, 0) != len;
1086 }
1087
1088 /* Write memory to the inferior process.  This should generally be
1089    called through write_inferior_memory, which handles breakpoint shadowing.
1090    Write LEN bytes from the buffer at MYADDR to MEMADDR.
1091    Returns 0 on success and errno on failure.  */
1092 static int
1093 win32_write_inferior_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
1094                              int len)
1095 {
1096   return child_xfer_memory (memaddr, (char *) myaddr, len, 1, 0) != len;
1097 }
1098
1099 static const char *
1100 win32_arch_string (void)
1101 {
1102   return "i386";
1103 }
1104
1105 static struct target_ops win32_target_ops = {
1106   win32_create_inferior,
1107   win32_attach,
1108   win32_kill,
1109   win32_detach,
1110   win32_thread_alive,
1111   win32_resume,
1112   win32_wait,
1113   win32_fetch_inferior_registers,
1114   win32_store_inferior_registers,
1115   win32_read_inferior_memory,
1116   win32_write_inferior_memory,
1117   NULL,
1118   NULL,
1119   NULL,
1120   NULL,
1121   NULL,
1122   NULL,
1123   NULL,
1124   NULL,
1125   NULL,
1126   win32_arch_string
1127 };
1128
1129 /* Initialize the Win32 backend.  */
1130 void
1131 initialize_low (void)
1132 {
1133   set_target_ops (&win32_target_ops);
1134
1135   init_registers ();
1136 }