gdb/inf-loop.c

   1 /* Handling of inferior events for the event loop for GDB, the GNU debugger.
   2    Copyright (C) 1999, 2007, 2008, 2009, 2010, 2011
   3    Free Software Foundation, Inc.
   4    Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"           /* For fetch_inferior_event.  */
  23 #include "target.h"             /* For enum inferior_event_type.  */
  24 #include "event-loop.h"
  25 #include "event-top.h"
  26 #include "inf-loop.h"
  27 #include "remote.h"
  28 #include "exceptions.h"
  29 #include "language.h"
  30 #include "gdbthread.h"
  31
  32 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  33
  34 void
  35 inferior_event_handler_wrapper (gdb_client_data client_data)
  36 {
  37   inferior_event_handler (INF_QUIT_REQ, client_data);
  38 }
  39
  40 /* General function to handle events in the inferior.  So far it just
  41    takes care of detecting errors reported by select() or poll(),
  42    otherwise it assumes that all is OK, and goes on reading data from
  43    the fd.  This however may not always be what we want to do.  */
  44 void
  45 inferior_event_handler (enum inferior_event_type event_type,
  46                         gdb_client_data client_data)
  47 {
  48   struct gdb_exception e;
  49   int was_sync = 0;
  50
  51   switch (event_type)
  52     {
  53     case INF_ERROR:
  54       printf_unfiltered (_("error detected from target.\n"));
  55       pop_all_targets_above (file_stratum, 0);
  56       discard_all_intermediate_continuations ();
  57       discard_all_continuations ();
  58       async_enable_stdin ();
  59       break;
  60
  61     case INF_REG_EVENT:
  62       /* Use catch errors for now, until the inner layers of
  63          fetch_inferior_event (i.e. readchar) can return meaningful
  64          error status.  If an error occurs while getting an event from
  65          the target, just get rid of the target.  */
  66       if (!catch_errors (fetch_inferior_event_wrapper,
  67                          client_data, "", RETURN_MASK_ALL))
  68         {
  69           pop_all_targets_above (file_stratum, 0);
  70           discard_all_intermediate_continuations ();
  71           discard_all_continuations ();
  72           async_enable_stdin ();
  73           display_gdb_prompt (0);
  74         }
  75       break;
  76
  77     case INF_EXEC_COMPLETE:
  78
  79       if (!non_stop)
  80         {
  81           /* Unregister the inferior from the event loop.  This is done
  82              so that when the inferior is not running we don't get
  83              distracted by spurious inferior output.  */
  84           if (target_has_execution)
  85             target_async (NULL, 0);
  86         }
  87
  88       /* The call to async_enable_stdin below resets 'sync_execution'.
  89          However, if sync_execution is 1 now, we also need to show the
  90          prompt below, so save the current value.  */
  91       was_sync = sync_execution;
  92       async_enable_stdin ();
  93
  94       /* Do all continuations associated with the whole inferior (not
  95          a particular thread).  */
  96       if (!ptid_equal (inferior_ptid, null_ptid))
  97         do_all_inferior_continuations ();
  98
  99       /* If we were doing a multi-step (eg: step n, next n), but it
 100          got interrupted by a breakpoint, still do the pending
 101          continuations.  The continuation itself is responsible for
 102          distinguishing the cases.  The continuations are allowed to
 103          touch the inferior memory, e.g. to remove breakpoints, so run
 104          them before running breakpoint commands, which may resume the
 105          target.  */
 106       if (non_stop
 107           && target_has_execution
 108           && !ptid_equal (inferior_ptid, null_ptid))
 109         do_all_intermediate_continuations_thread (inferior_thread ());
 110       else
 111         do_all_intermediate_continuations ();
 112
 113       /* Always finish the previous command before running any
 114          breakpoint commands.  Any stop cancels the previous command.
 115          E.g. a "finish" or "step-n" command interrupted by an
 116          unrelated breakpoint is canceled.  */
 117       if (non_stop
 118           && target_has_execution
 119           && !ptid_equal (inferior_ptid, null_ptid))
 120         do_all_continuations_thread (inferior_thread ());
 121       else
 122         do_all_continuations ();
 123
 124       if (info_verbose
 125           && current_language != expected_language
 126           && language_mode == language_mode_auto)
 127         language_info (1);      /* Print what changed.  */
 128
 129       /* Don't propagate breakpoint commands errors.  Either we're
 130          stopping or some command resumes the inferior.  The user will
 131          be informed.  */
 132       TRY_CATCH (e, RETURN_MASK_ALL)
 133         {
 134           bpstat_do_actions ();
 135         }
 136
 137       if (!was_sync
 138           && exec_done_display_p
 139           && (ptid_equal (inferior_ptid, null_ptid)
 140               || !is_running (inferior_ptid)))
 141         printf_unfiltered (_("completed.\n"));
 142       break;
 143
 144     case INF_EXEC_CONTINUE:
 145       /* Is there anything left to do for the command issued to
 146          complete?  */
 147
 148       if (non_stop)
 149         do_all_intermediate_continuations_thread (inferior_thread ());
 150       else
 151         do_all_intermediate_continuations ();
 152       break;
 153
 154     case INF_QUIT_REQ:
 155       /* FIXME: ezannoni 1999-10-04.  This call should really be a
 156          target vector entry, so that it can be used for any kind of
 157          targets.  */
 158       async_remote_interrupt_twice (NULL);
 159       break;
 160
 161     case INF_TIMER:
 162     default:
 163       printf_unfiltered (_("Event type not recognized.\n"));
 164       break;
 165     }
 166 }
 167
 168 static int
 169 fetch_inferior_event_wrapper (gdb_client_data client_data)
 170 {
 171   fetch_inferior_event (client_data);
 172   return 1;
 173 }