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 Free Software Foundation, Inc.
   3    Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  19
  20 #include "defs.h"
  21 #include "inferior.h"           /* For fetch_inferior_event. */
  22 #include "target.h"             /* For enum inferior_event_type. */
  23 #include "event-loop.h"
  24 #include "event-top.h"
  25 #include "inf-loop.h"
  26 #include "remote.h"
  27 #include "exceptions.h"
  28 #include "language.h"
  29 #include "gdbthread.h"
  30
  31 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  32
  33 void
  34 inferior_event_handler_wrapper (gdb_client_data client_data)
  35 {
  36   inferior_event_handler (INF_QUIT_REQ, client_data);
  37 }
  38
  39 /* General function to handle events in the inferior. So far it just
  40    takes care of detecting errors reported by select() or poll(),
  41    otherwise it assumes that all is OK, and goes on reading data from
  42    the fd. This however may not always be what we want to do. */
  43 void
  44 inferior_event_handler (enum inferior_event_type event_type,
  45                         gdb_client_data client_data)
  46 {
  47   struct gdb_exception e;
  48   int was_sync = 0;
  49   switch (event_type)
  50     {
  51     case INF_ERROR:
  52       printf_unfiltered (_("error detected from target.\n"));
  53       pop_all_targets_above (file_stratum, 0);
  54       discard_all_intermediate_continuations ();
  55       discard_all_continuations ();
  56       async_enable_stdin ();
  57       break;
  58
  59     case INF_REG_EVENT:
  60       /* Use catch errors for now, until the inner layers of
  61          fetch_inferior_event (i.e. readchar) can return meaningful
  62          error status.  If an error occurs while getting an event from
  63          the target, just get rid of the target. */
  64       if (!catch_errors (fetch_inferior_event_wrapper,
  65                          client_data, "", RETURN_MASK_ALL))
  66         {
  67           pop_all_targets_above (file_stratum, 0);
  68           discard_all_intermediate_continuations ();
  69           discard_all_continuations ();
  70           async_enable_stdin ();
  71           display_gdb_prompt (0);
  72         }
  73       break;
  74
  75     case INF_EXEC_COMPLETE:
  76
  77       if (!non_stop)
  78         {
  79           /* Unregister the inferior from the event loop. This is done
  80              so that when the inferior is not running we don't get
  81              distracted by spurious inferior output.  */
  82           if (target_has_execution)
  83             target_async (NULL, 0);
  84         }
  85
  86       /* The call to async_enable_stdin below resets 'sync_execution'.
  87          However, if sync_execution is 1 now, we also need to show the
  88          prompt below, so save the current value.  */
  89       was_sync = sync_execution;
  90       async_enable_stdin ();
  91
  92       /* Do all continuations associated with the whole inferior (not
  93          a particular thread).  */
  94       if (!ptid_equal (inferior_ptid, null_ptid))
  95         do_all_inferior_continuations ();
  96
  97       /* If we were doing a multi-step (eg: step n, next n), but it
  98          got interrupted by a breakpoint, still do the pending
  99          continuations.  The continuation itself is responsible for
 100          distinguishing the cases.  The continuations are allowed to
 101          touch the inferior memory, e.g. to remove breakpoints, so run
 102          them before running breakpoint commands, which may resume the
 103          target.  */
 104       if (non_stop
 105           && target_has_execution
 106           && !ptid_equal (inferior_ptid, null_ptid))
 107         do_all_intermediate_continuations_thread (inferior_thread ());
 108       else
 109         do_all_intermediate_continuations ();
 110
 111       /* Always finish the previous command before running any
 112          breakpoint commands.  Any stop cancels the previous command.
 113          E.g. a "finish" or "step-n" command interrupted by an
 114          unrelated breakpoint is canceled.  */
 115       if (non_stop
 116           && target_has_execution
 117           && !ptid_equal (inferior_ptid, null_ptid))
 118         do_all_continuations_thread (inferior_thread ());
 119       else
 120         do_all_continuations ();
 121
 122       if (current_language != expected_language
 123           && language_mode == language_mode_auto)
 124         language_info (1);      /* Print what changed.  */
 125
 126       /* Don't propagate breakpoint commands errors.  Either we're
 127          stopping or some command resumes the inferior.  The user will
 128          be informed.  */
 129       TRY_CATCH (e, RETURN_MASK_ALL)
 130         {
 131           bpstat_do_actions ();
 132         }
 133
 134       if (!was_sync
 135           && exec_done_display_p
 136           && (ptid_equal (inferior_ptid, null_ptid)
 137               || !is_running (inferior_ptid)))
 138         printf_unfiltered (_("completed.\n"));
 139       break;
 140
 141     case INF_EXEC_CONTINUE:
 142       /* Is there anything left to do for the command issued to
 143          complete? */
 144
 145       if (non_stop)
 146         do_all_intermediate_continuations_thread (inferior_thread ());
 147       else
 148         do_all_intermediate_continuations ();
 149       break;
 150
 151     case INF_QUIT_REQ:
 152       /* FIXME: ezannoni 1999-10-04. This call should really be a
 153          target vector entry, so that it can be used for any kind of
 154          targets. */
 155       async_remote_interrupt_twice (NULL);
 156       break;
 157
 158     case INF_TIMER:
 159     default:
 160       printf_unfiltered (_("Event type not recognized.\n"));
 161       break;
 162     }
 163 }
 164
 165 static int
 166 fetch_inferior_event_wrapper (gdb_client_data client_data)
 167 {
 168   fetch_inferior_event (client_data);
 169   return 1;
 170 }