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 #include "continuations.h"
  32
  33 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  34
  35 /* General function to handle events in the inferior.  So far it just
  36    takes care of detecting errors reported by select() or poll(),
  37    otherwise it assumes that all is OK, and goes on reading data from
  38    the fd.  This however may not always be what we want to do.  */
  39 void
  40 inferior_event_handler (enum inferior_event_type event_type,
  41                         gdb_client_data client_data)
  42 {
  43   struct gdb_exception e;
  44   int was_sync = 0;
  45
  46   switch (event_type)
  47     {
  48     case INF_REG_EVENT:
  49       /* Use catch errors for now, until the inner layers of
  50          fetch_inferior_event (i.e. readchar) can return meaningful
  51          error status.  If an error occurs while getting an event from
  52          the target, just cancel the current command.  */
  53       if (!catch_errors (fetch_inferior_event_wrapper,
  54                          client_data, "", RETURN_MASK_ALL))
  55         {
  56           do_all_intermediate_continuations (1);
  57           do_all_continuations (1);
  58           async_enable_stdin ();
  59           display_gdb_prompt (0);
  60         }
  61       break;
  62
  63     case INF_EXEC_COMPLETE:
  64
  65       if (!non_stop)
  66         {
  67           /* Unregister the inferior from the event loop.  This is done
  68              so that when the inferior is not running we don't get
  69              distracted by spurious inferior output.  */
  70           if (target_has_execution)
  71             target_async (NULL, 0);
  72         }
  73
  74       /* The call to async_enable_stdin below resets 'sync_execution'.
  75          However, if sync_execution is 1 now, we also need to show the
  76          prompt below, so save the current value.  */
  77       was_sync = sync_execution;
  78       async_enable_stdin ();
  79
  80       /* Do all continuations associated with the whole inferior (not
  81          a particular thread).  */
  82       if (!ptid_equal (inferior_ptid, null_ptid))
  83         do_all_inferior_continuations (0);
  84
  85       /* If we were doing a multi-step (eg: step n, next n), but it
  86          got interrupted by a breakpoint, still do the pending
  87          continuations.  The continuation itself is responsible for
  88          distinguishing the cases.  The continuations are allowed to
  89          touch the inferior memory, e.g. to remove breakpoints, so run
  90          them before running breakpoint commands, which may resume the
  91          target.  */
  92       if (non_stop
  93           && target_has_execution
  94           && !ptid_equal (inferior_ptid, null_ptid))
  95         do_all_intermediate_continuations_thread (inferior_thread (), 0);
  96       else
  97         do_all_intermediate_continuations (0);
  98
  99       /* Always finish the previous command before running any
 100          breakpoint commands.  Any stop cancels the previous command.
 101          E.g. a "finish" or "step-n" command interrupted by an
 102          unrelated breakpoint is canceled.  */
 103       if (non_stop
 104           && target_has_execution
 105           && !ptid_equal (inferior_ptid, null_ptid))
 106         do_all_continuations_thread (inferior_thread (), 0);
 107       else
 108         do_all_continuations (0);
 109
 110       if (info_verbose
 111           && current_language != expected_language
 112           && language_mode == language_mode_auto)
 113         language_info (1);      /* Print what changed.  */
 114
 115       /* Don't propagate breakpoint commands errors.  Either we're
 116          stopping or some command resumes the inferior.  The user will
 117          be informed.  */
 118       TRY_CATCH (e, RETURN_MASK_ALL)
 119         {
 120           bpstat_do_actions ();
 121         }
 122
 123       if (!was_sync
 124           && exec_done_display_p
 125           && (ptid_equal (inferior_ptid, null_ptid)
 126               || !is_running (inferior_ptid)))
 127         printf_unfiltered (_("completed.\n"));
 128       break;
 129
 130     case INF_EXEC_CONTINUE:
 131       /* Is there anything left to do for the command issued to
 132          complete?  */
 133
 134       if (non_stop)
 135         do_all_intermediate_continuations_thread (inferior_thread (), 0);
 136       else
 137         do_all_intermediate_continuations (0);
 138       break;
 139
 140     case INF_TIMER:
 141     default:
 142       printf_unfiltered (_("Event type not recognized.\n"));
 143       break;
 144     }
 145 }
 146
 147 static int
 148 fetch_inferior_event_wrapper (gdb_client_data client_data)
 149 {
 150   fetch_inferior_event (client_data);
 151   return 1;
 152 }