1 /* Handling of inferior events for the event loop for GDB, the GNU debugger. 2 Copyright (C) 1999-2015 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 "language.h" 29 #include "gdbthread.h" 30 #include "continuations.h" 31 #include "interps.h" 32 #include "top.h" 33 #include "observer.h" 34 35 /* General function to handle events in the inferior. So far it just 36 takes care of detecting errors reported by select() or poll(), 37 otherwise it assumes that all is OK, and goes on reading data from 38 the fd. This however may not always be what we want to do. */ 39 void 40 inferior_event_handler (enum inferior_event_type event_type, 41 gdb_client_data client_data) 42 { 43 struct cleanup *cleanup_if_error = make_bpstat_clear_actions_cleanup (); 44 45 switch (event_type) 46 { 47 case INF_REG_EVENT: 48 /* Catch errors for now, until the inner layers of 49 fetch_inferior_event (i.e. readchar) can return meaningful 50 error status. If an error occurs while getting an event from 51 the target, just cancel the current command. */ 52 { 53 volatile struct gdb_exception ex; 54 55 TRY_CATCH (ex, RETURN_MASK_ALL) 56 { 57 fetch_inferior_event (client_data); 58 } 59 if (ex.reason < 0) 60 { 61 bpstat_clear_actions (); 62 do_all_intermediate_continuations (1); 63 do_all_continuations (1); 64 65 throw_exception (ex); 66 } 67 } 68 break; 69 70 case INF_EXEC_COMPLETE: 71 if (!non_stop) 72 { 73 /* Unregister the inferior from the event loop. This is done 74 so that when the inferior is not running we don't get 75 distracted by spurious inferior output. */ 76 if (target_has_execution) 77 target_async (NULL, 0); 78 } 79 80 /* Do all continuations associated with the whole inferior (not 81 a particular thread). */ 82 if (!ptid_equal (inferior_ptid, null_ptid)) 83 do_all_inferior_continuations (0); 84 85 /* If we were doing a multi-step (eg: step n, next n), but it 86 got interrupted by a breakpoint, still do the pending 87 continuations. The continuation itself is responsible for 88 distinguishing the cases. The continuations are allowed to 89 touch the inferior memory, e.g. to remove breakpoints, so run 90 them before running breakpoint commands, which may resume the 91 target. */ 92 if (non_stop 93 && target_has_execution 94 && !ptid_equal (inferior_ptid, null_ptid)) 95 do_all_intermediate_continuations_thread (inferior_thread (), 0); 96 else 97 do_all_intermediate_continuations (0); 98 99 /* Always finish the previous command before running any 100 breakpoint commands. Any stop cancels the previous command. 101 E.g. a "finish" or "step-n" command interrupted by an 102 unrelated breakpoint is canceled. */ 103 if (non_stop 104 && target_has_execution 105 && !ptid_equal (inferior_ptid, null_ptid)) 106 do_all_continuations_thread (inferior_thread (), 0); 107 else 108 do_all_continuations (0); 109 110 /* When running a command list (from a user command, say), these 111 are only run when the command list is all done. */ 112 if (interpreter_async) 113 { 114 volatile struct gdb_exception e; 115 116 check_frame_language_change (); 117 118 /* Don't propagate breakpoint commands errors. Either we're 119 stopping or some command resumes the inferior. The user will 120 be informed. */ 121 TRY_CATCH (e, RETURN_MASK_ALL) 122 { 123 bpstat_do_actions (); 124 } 125 exception_print (gdb_stderr, e); 126 } 127 break; 128 129 case INF_EXEC_CONTINUE: 130 /* Is there anything left to do for the command issued to 131 complete? */ 132 133 if (non_stop) 134 do_all_intermediate_continuations_thread (inferior_thread (), 0); 135 else 136 do_all_intermediate_continuations (0); 137 break; 138 139 case INF_TIMER: 140 default: 141 printf_unfiltered (_("Event type not recognized.\n")); 142 break; 143 } 144 145 discard_cleanups (cleanup_if_error); 146 } 147