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
  50   switch (event_type)
  51     {
  52     case INF_ERROR:
  53       printf_unfiltered (_("error detected from target.\n"));
  54       pop_all_targets_above (file_stratum, 0);
  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           pop_all_targets_above (file_stratum, 0);
  69           discard_all_intermediate_continuations ();
  70           discard_all_continuations ();
  71           async_enable_stdin ();
  72           display_gdb_prompt (0);
  73         }
  74       break;
  75
  76     case INF_EXEC_COMPLETE:
  77
  78       if (!non_stop)
  79         {
  80           /* Unregister the inferior from the event loop. This is done
  81              so that when the inferior is not running we don't get
  82              distracted by spurious inferior output.  */
  83           if (target_has_execution)
  84             target_async (NULL, 0);
  85         }
  86
  87       /* The call to async_enable_stdin below resets 'sync_execution'.
  88          However, if sync_execution is 1 now, we also need to show the
  89          prompt below, so save the current value.  */
  90       was_sync = sync_execution;
  91       async_enable_stdin ();
  92
  93       /* Do all continuations associated with the whole inferior (not
  94          a particular thread).  */
  95       if (!ptid_equal (inferior_ptid, null_ptid))
  96         do_all_inferior_continuations ();
  97
  98       /* If we were doing a multi-step (eg: step n, next n), but it
  99          got interrupted by a breakpoint, still do the pending
 100          continuations.  The continuation itself is responsible for
 101          distinguishing the cases.  The continuations are allowed to
 102          touch the inferior memory, e.g. to remove breakpoints, so run
 103          them before running breakpoint commands, which may resume the
 104          target.  */
 105       if (non_stop
 106           && target_has_execution
 107           && !ptid_equal (inferior_ptid, null_ptid))
 108         do_all_intermediate_continuations_thread (inferior_thread ());
 109       else
 110         do_all_intermediate_continuations ();
 111
 112       /* Always finish the previous command before running any
 113          breakpoint commands.  Any stop cancels the previous command.
 114          E.g. a "finish" or "step-n" command interrupted by an
 115          unrelated breakpoint is canceled.  */
 116       if (non_stop
 117           && target_has_execution
 118           && !ptid_equal (inferior_ptid, null_ptid))
 119         do_all_continuations_thread (inferior_thread ());
 120       else
 121         do_all_continuations ();
 122
 123       if (current_language != expected_language
 124           && language_mode == language_mode_auto)
 125         language_info (1);      /* Print what changed.  */
 126
 127       /* Don't propagate breakpoint commands errors.  Either we're
 128          stopping or some command resumes the inferior.  The user will
 129          be informed.  */
 130       TRY_CATCH (e, RETURN_MASK_ALL)
 131         {
 132           bpstat_do_actions ();
 133         }
 134
 135       if (!was_sync
 136           && exec_done_display_p
 137           && (ptid_equal (inferior_ptid, null_ptid)
 138               || !is_running (inferior_ptid)))
 139         printf_unfiltered (_("completed.\n"));
 140       break;
 141
 142     case INF_EXEC_CONTINUE:
 143       /* Is there anything left to do for the command issued to
 144          complete? */
 145
 146       if (non_stop)
 147         do_all_intermediate_continuations_thread (inferior_thread ());
 148       else
 149         do_all_intermediate_continuations ();
 150       break;
 151
 152     case INF_QUIT_REQ:
 153       /* FIXME: ezannoni 1999-10-04. This call should really be a
 154          target vector entry, so that it can be used for any kind of
 155          targets. */
 156       async_remote_interrupt_twice (NULL);
 157       break;
 158
 159     case INF_TIMER:
 160     default:
 161       printf_unfiltered (_("Event type not recognized.\n"));
 162       break;
 163     }
 164 }
 165
 166 static int
 167 fetch_inferior_event_wrapper (gdb_client_data client_data)
 168 {
 169   fetch_inferior_event (client_data);
 170   return 1;
 171 }