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
  30 static int fetch_inferior_event_wrapper (gdb_client_data client_data);
  31
  32 void
  33 inferior_event_handler_wrapper (gdb_client_data client_data)
  34 {
  35   inferior_event_handler (INF_QUIT_REQ, client_data);
  36 }
  37
  38 /* General function to handle events in the inferior. So far it just
  39    takes care of detecting errors reported by select() or poll(),
  40    otherwise it assumes that all is OK, and goes on reading data from
  41    the fd. This however may not always be what we want to do. */
  42 void
  43 inferior_event_handler (enum inferior_event_type event_type,
  44                         gdb_client_data client_data)
  45 {
  46   struct gdb_exception e;
  47   int was_sync = 0;
  48   switch (event_type)
  49     {
  50     case INF_ERROR:
  51       printf_unfiltered (_("error detected from target.\n"));
  52       target_async (NULL, 0);
  53       pop_target ();
  54       do_all_continuations (1);
  55       async_enable_stdin ();
  56       break;
  57
  58     case INF_REG_EVENT:
  59       /* Use catch errors for now, until the inner layers of
  60          fetch_inferior_event (i.e. readchar) can return meaningful
  61          error status.  If an error occurs while getting an event from
  62          the target, just get rid of the target. */
  63       if (!catch_errors (fetch_inferior_event_wrapper,
  64                          client_data, "", RETURN_MASK_ALL))
  65         {
  66           target_async (NULL, 0);
  67           pop_target ();
  68           do_all_continuations (1);
  69           async_enable_stdin ();
  70           display_gdb_prompt (0);
  71         }
  72       break;
  73
  74     case INF_EXEC_COMPLETE:
  75
  76       /* This is the first thing to do -- so that continuations know that
  77          the target is stopped.  For example, command_line_handler_continuation
  78          will run breakpoint commands, and if we think that the target is
  79          running, we'll refuse to execute most commands.  MI continuation
  80          presently uses target_executing to either print or not print *stopped.  */
  81       target_executing = 0;
  82
  83       /* Unregister the inferior from the event loop. This is done so that
  84          when the inferior is not running we don't get distracted by
  85          spurious inferior output.  */
  86       if (target_has_execution)
  87         target_async (NULL, 0);
  88
  89       /* The call to async_enable_stdin below resets 'sync_execution'.
  90          However, if sync_execution is 1 now, we also need to show the
  91          prompt below, so save the current value.  */
  92       was_sync = sync_execution;
  93       async_enable_stdin ();
  94
  95       /* If we were doing a multi-step (eg: step n, next n), but it
  96          got interrupted by a breakpoint, still do the pending
  97          continuations.  The continuation itself is responsible for
  98          distinguishing the cases.  The continuations are allowed to
  99          touch the inferior memory, e.g. to remove breakpoints, so run
 100          them before running breakpoint commands, which may resume the
 101          target.  */
 102       do_all_intermediate_continuations (0);
 103
 104       /* Always finish the previous command before running any
 105          breakpoint commands.  Any stop cancels the previous command.
 106          E.g. a "finish" or "step-n" command interrupted by an
 107          unrelated breakpoint is canceled.  */
 108       do_all_continuations (0);
 109
 110       if (current_language != expected_language
 111           && language_mode == language_mode_auto)
 112         language_info (1);      /* Print what changed.  */
 113
 114       /* Don't propagate breakpoint commands errors.  Either we're
 115          stopping or some command resumes the inferior.  The user will
 116          be informed.  */
 117       TRY_CATCH (e, RETURN_MASK_ALL)
 118         {
 119           bpstat_do_actions (&stop_bpstat);
 120         }
 121
 122       /* If no breakpoint command resumed the inferior, prepare for
 123          interaction with the user.  */
 124       if (!target_executing)
 125         {
 126           if (was_sync)
 127             {
 128               display_gdb_prompt (0);
 129             }
 130           else
 131             {
 132               if (exec_done_display_p)
 133                 printf_unfiltered (_("completed.\n"));
 134             }
 135         }
 136       break;
 137
 138     case INF_EXEC_CONTINUE:
 139       /* Is there anything left to do for the command issued to
 140          complete? */
 141       do_all_intermediate_continuations (0);
 142       break;
 143
 144     case INF_QUIT_REQ:
 145       /* FIXME: ezannoni 1999-10-04. This call should really be a
 146          target vector entry, so that it can be used for any kind of
 147          targets. */
 148       async_remote_interrupt_twice (NULL);
 149       break;
 150
 151     case INF_TIMER:
 152     default:
 153       printf_unfiltered (_("Event type not recognized.\n"));
 154       break;
 155     }
 156 }
 157
 158 static int
 159 fetch_inferior_event_wrapper (gdb_client_data client_data)
 160 {
 161   fetch_inferior_event (client_data);
 162   return 1;
 163 }