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 #include "interps.h"
  33
  34 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  35
  36 /* General function to handle events in the inferior.  So far it just
  37    takes care of detecting errors reported by select() or poll(),
  38    otherwise it assumes that all is OK, and goes on reading data from
  39    the fd.  This however may not always be what we want to do.  */
  40 void
  41 inferior_event_handler (enum inferior_event_type event_type,
  42                         gdb_client_data client_data)
  43 {
  44   struct cleanup *cleanup_if_error = make_bpstat_clear_actions_cleanup ();
  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           bpstat_clear_actions ();
  57           do_all_intermediate_continuations (1);
  58           do_all_continuations (1);
  59           async_enable_stdin ();
  60           display_gdb_prompt (0);
  61         }
  62       break;
  63
  64     case INF_EXEC_COMPLETE:
  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       /* Do all continuations associated with the whole inferior (not
  75          a particular thread).  */
  76       if (!ptid_equal (inferior_ptid, null_ptid))
  77         do_all_inferior_continuations (0);
  78
  79       /* If we were doing a multi-step (eg: step n, next n), but it
  80          got interrupted by a breakpoint, still do the pending
  81          continuations.  The continuation itself is responsible for
  82          distinguishing the cases.  The continuations are allowed to
  83          touch the inferior memory, e.g. to remove breakpoints, so run
  84          them before running breakpoint commands, which may resume the
  85          target.  */
  86       if (non_stop
  87           && target_has_execution
  88           && !ptid_equal (inferior_ptid, null_ptid))
  89         do_all_intermediate_continuations_thread (inferior_thread (), 0);
  90       else
  91         do_all_intermediate_continuations (0);
  92
  93       /* Always finish the previous command before running any
  94          breakpoint commands.  Any stop cancels the previous command.
  95          E.g. a "finish" or "step-n" command interrupted by an
  96          unrelated breakpoint is canceled.  */
  97       if (non_stop
  98           && target_has_execution
  99           && !ptid_equal (inferior_ptid, null_ptid))
 100         do_all_continuations_thread (inferior_thread (), 0);
 101       else
 102         do_all_continuations (0);
 103
 104       /* When running a command list (from a user command, say), these
 105          are only run when the command list is all done.  */
 106       if (interpreter_async)
 107         {
 108           volatile struct gdb_exception e;
 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           exception_print (gdb_stderr, e);
 123         }
 124       break;
 125
 126     case INF_EXEC_CONTINUE:
 127       /* Is there anything left to do for the command issued to
 128          complete?  */
 129
 130       if (non_stop)
 131         do_all_intermediate_continuations_thread (inferior_thread (), 0);
 132       else
 133         do_all_intermediate_continuations (0);
 134       break;
 135
 136     case INF_TIMER:
 137     default:
 138       printf_unfiltered (_("Event type not recognized.\n"));
 139       break;
 140     }
 141
 142   discard_cleanups (cleanup_if_error);
 143 }
 144
 145 static int
 146 fetch_inferior_event_wrapper (gdb_client_data client_data)
 147 {
 148   fetch_inferior_event (client_data);
 149   return 1;
 150 }