1 /* Handling of inferior events for the event loop for GDB, the GNU debugger. 2 Copyright (C) 1999-2013 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 #include "continuations.h" 31 #include "interps.h" 32 #include "top.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 check_frame_language_change (); 111 112 /* Don't propagate breakpoint commands errors. Either we're 113 stopping or some command resumes the inferior. The user will 114 be informed. */ 115 TRY_CATCH (e, RETURN_MASK_ALL) 116 { 117 bpstat_do_actions (); 118 } 119 exception_print (gdb_stderr, e); 120 } 121 break; 122 123 case INF_EXEC_CONTINUE: 124 /* Is there anything left to do for the command issued to 125 complete? */ 126 127 if (non_stop) 128 do_all_intermediate_continuations_thread (inferior_thread (), 0); 129 else 130 do_all_intermediate_continuations (0); 131 break; 132 133 case INF_TIMER: 134 default: 135 printf_unfiltered (_("Event type not recognized.\n")); 136 break; 137 } 138 139 discard_cleanups (cleanup_if_error); 140 } 141 142 static int 143 fetch_inferior_event_wrapper (gdb_client_data client_data) 144 { 145 fetch_inferior_event (client_data); 146 return 1; 147 } 148