gdb/inf-loop.c

   1 /* Handling of inferior events for the event loop for GDB, the GNU debugger.
   2    Copyright (C) 1999-2014 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"
  22 #include "infrun.h"
  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 #include "interps.h"
  33 #include "top.h"
  34
  35 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  36
  37 /* General function to handle events in the inferior.  So far it just
  38    takes care of detecting errors reported by select() or poll(),
  39    otherwise it assumes that all is OK, and goes on reading data from
  40    the fd.  This however may not always be what we want to do.  */
  41 void
  42 inferior_event_handler (enum inferior_event_type event_type,
  43                         gdb_client_data client_data)
  44 {
  45   struct cleanup *cleanup_if_error = make_bpstat_clear_actions_cleanup ();
  46
  47   switch (event_type)
  48     {
  49     case INF_REG_EVENT:
  50       /* Use catch errors for now, until the inner layers of
  51          fetch_inferior_event (i.e. readchar) can return meaningful
  52          error status.  If an error occurs while getting an event from
  53          the target, just cancel the current command.  */
  54       if (!catch_errors (fetch_inferior_event_wrapper,
  55                          client_data, "", RETURN_MASK_ALL))
  56         {
  57           bpstat_clear_actions ();
  58           do_all_intermediate_continuations (1);
  59           do_all_continuations (1);
  60           async_enable_stdin ();
  61           display_gdb_prompt (0);
  62         }
  63       break;
  64
  65     case INF_EXEC_COMPLETE:
  66       if (!non_stop)
  67         {
  68           /* Unregister the inferior from the event loop.  This is done
  69              so that when the inferior is not running we don't get
  70              distracted by spurious inferior output.  */
  71           if (target_has_execution)
  72             target_async (NULL, 0);
  73         }
  74
  75       /* Do all continuations associated with the whole inferior (not
  76          a particular thread).  */
  77       if (!ptid_equal (inferior_ptid, null_ptid))
  78         do_all_inferior_continuations (0);
  79
  80       /* If we were doing a multi-step (eg: step n, next n), but it
  81          got interrupted by a breakpoint, still do the pending
  82          continuations.  The continuation itself is responsible for
  83          distinguishing the cases.  The continuations are allowed to
  84          touch the inferior memory, e.g. to remove breakpoints, so run
  85          them before running breakpoint commands, which may resume the
  86          target.  */
  87       if (non_stop
  88           && target_has_execution
  89           && !ptid_equal (inferior_ptid, null_ptid))
  90         do_all_intermediate_continuations_thread (inferior_thread (), 0);
  91       else
  92         do_all_intermediate_continuations (0);
  93
  94       /* Always finish the previous command before running any
  95          breakpoint commands.  Any stop cancels the previous command.
  96          E.g. a "finish" or "step-n" command interrupted by an
  97          unrelated breakpoint is canceled.  */
  98       if (non_stop
  99           && target_has_execution
 100           && !ptid_equal (inferior_ptid, null_ptid))
 101         do_all_continuations_thread (inferior_thread (), 0);
 102       else
 103         do_all_continuations (0);
 104
 105       /* When running a command list (from a user command, say), these
 106          are only run when the command list is all done.  */
 107       if (interpreter_async)
 108         {
 109           volatile struct gdb_exception e;
 110
 111           check_frame_language_change ();
 112
 113           /* Don't propagate breakpoint commands errors.  Either we're
 114              stopping or some command resumes the inferior.  The user will
 115              be informed.  */
 116           TRY_CATCH (e, RETURN_MASK_ALL)
 117             {
 118               bpstat_do_actions ();
 119             }
 120           exception_print (gdb_stderr, e);
 121         }
 122       break;
 123
 124     case INF_EXEC_CONTINUE:
 125       /* Is there anything left to do for the command issued to
 126          complete?  */
 127
 128       if (non_stop)
 129         do_all_intermediate_continuations_thread (inferior_thread (), 0);
 130       else
 131         do_all_intermediate_continuations (0);
 132       break;
 133
 134     case INF_TIMER:
 135     default:
 136       printf_unfiltered (_("Event type not recognized.\n"));
 137       break;
 138     }
 139
 140   discard_cleanups (cleanup_if_error);
 141 }
 142
 143 static int
 144 fetch_inferior_event_wrapper (gdb_client_data client_data)
 145 {
 146   fetch_inferior_event (client_data);
 147   return 1;
 148 }