gdb/inf-loop.c

   1 /* Handling of inferior events for the event loop for GDB, the GNU debugger.
   2    Copyright (C) 1999, 2007, 2008 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       /* If we were doing a multi-step (eg: step n, next n), but it
  93          got interrupted by a breakpoint, still do the pending
  94          continuations.  The continuation itself is responsible for
  95          distinguishing the cases.  The continuations are allowed to
  96          touch the inferior memory, e.g. to remove breakpoints, so run
  97          them before running breakpoint commands, which may resume the
  98          target.  */
  99       if (non_stop
 100           && target_has_execution
 101           && !ptid_equal (inferior_ptid, null_ptid))
 102         do_all_intermediate_continuations_thread (inferior_thread ());
 103       else
 104         do_all_intermediate_continuations ();
 105
 106       /* Always finish the previous command before running any
 107          breakpoint commands.  Any stop cancels the previous command.
 108          E.g. a "finish" or "step-n" command interrupted by an
 109          unrelated breakpoint is canceled.  */
 110       if (non_stop
 111           && target_has_execution
 112           && !ptid_equal (inferior_ptid, null_ptid))
 113         do_all_continuations_thread (inferior_thread ());
 114       else
 115         do_all_continuations ();
 116
 117       if (current_language != expected_language
 118           && language_mode == language_mode_auto)
 119         language_info (1);      /* Print what changed.  */
 120
 121       /* Don't propagate breakpoint commands errors.  Either we're
 122          stopping or some command resumes the inferior.  The user will
 123          be informed.  */
 124       TRY_CATCH (e, RETURN_MASK_ALL)
 125         {
 126           bpstat_do_actions ();
 127         }
 128
 129       if (!was_sync && !is_running (inferior_ptid) && exec_done_display_p)
 130         printf_unfiltered (_("completed.\n"));
 131       break;
 132
 133     case INF_EXEC_CONTINUE:
 134       /* Is there anything left to do for the command issued to
 135          complete? */
 136
 137       if (non_stop)
 138         do_all_intermediate_continuations_thread (inferior_thread ());
 139       else
 140         do_all_intermediate_continuations ();
 141       break;
 142
 143     case INF_QUIT_REQ:
 144       /* FIXME: ezannoni 1999-10-04. This call should really be a
 145          target vector entry, so that it can be used for any kind of
 146          targets. */
 147       async_remote_interrupt_twice (NULL);
 148       break;
 149
 150     case INF_TIMER:
 151     default:
 152       printf_unfiltered (_("Event type not recognized.\n"));
 153       break;
 154     }
 155 }
 156
 157 static int
 158 fetch_inferior_event_wrapper (gdb_client_data client_data)
 159 {
 160   fetch_inferior_event (client_data);
 161   return 1;
 162 }