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       target_async (NULL, 0);
  54       pop_target ();
  55       discard_all_intermediate_continuations ();
  56       discard_all_continuations ();
  57       async_enable_stdin ();
  58       break;
  59
  60     case INF_REG_EVENT:
  61       /* Use catch errors for now, until the inner layers of
  62          fetch_inferior_event (i.e. readchar) can return meaningful
  63          error status.  If an error occurs while getting an event from
  64          the target, just get rid of the target. */
  65       if (!catch_errors (fetch_inferior_event_wrapper,
  66                          client_data, "", RETURN_MASK_ALL))
  67         {
  68           target_async (NULL, 0);
  69           pop_target ();
  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       /* If we were doing a multi-step (eg: step n, next n), but it
  95          got interrupted by a breakpoint, still do the pending
  96          continuations.  The continuation itself is responsible for
  97          distinguishing the cases.  The continuations are allowed to
  98          touch the inferior memory, e.g. to remove breakpoints, so run
  99          them before running breakpoint commands, which may resume the
 100          target.  */
 101       if (non_stop
 102           && target_has_execution
 103           && !ptid_equal (inferior_ptid, null_ptid))
 104         do_all_intermediate_continuations_thread (inferior_thread ());
 105       else
 106         do_all_intermediate_continuations ();
 107
 108       /* Always finish the previous command before running any
 109          breakpoint commands.  Any stop cancels the previous command.
 110          E.g. a "finish" or "step-n" command interrupted by an
 111          unrelated breakpoint is canceled.  */
 112       if (non_stop
 113           && target_has_execution
 114           && !ptid_equal (inferior_ptid, null_ptid))
 115         do_all_continuations_thread (inferior_thread ());
 116       else
 117         do_all_continuations ();
 118
 119       if (current_language != expected_language
 120           && language_mode == language_mode_auto)
 121         language_info (1);      /* Print what changed.  */
 122
 123       /* Don't propagate breakpoint commands errors.  Either we're
 124          stopping or some command resumes the inferior.  The user will
 125          be informed.  */
 126       TRY_CATCH (e, RETURN_MASK_ALL)
 127         {
 128           bpstat_do_actions ();
 129         }
 130
 131       if (!was_sync && !is_running (inferior_ptid) && exec_done_display_p)
 132         printf_unfiltered (_("completed.\n"));
 133       break;
 134
 135     case INF_EXEC_CONTINUE:
 136       /* Is there anything left to do for the command issued to
 137          complete? */
 138
 139       if (non_stop)
 140         do_all_intermediate_continuations_thread (inferior_thread ());
 141       else
 142         do_all_intermediate_continuations ();
 143       break;
 144
 145     case INF_QUIT_REQ:
 146       /* FIXME: ezannoni 1999-10-04. This call should really be a
 147          target vector entry, so that it can be used for any kind of
 148          targets. */
 149       async_remote_interrupt_twice (NULL);
 150       break;
 151
 152     case INF_TIMER:
 153     default:
 154       printf_unfiltered (_("Event type not recognized.\n"));
 155       break;
 156     }
 157 }
 158
 159 static int
 160 fetch_inferior_event_wrapper (gdb_client_data client_data)
 161 {
 162   fetch_inferior_event (client_data);
 163   return 1;
 164 }