| 1 | /* Thread command's finish-state machine, for GDB, the GNU debugger. |
| 2 | Copyright (C) 2015-2019 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #ifndef THREAD_FSM_H |
| 20 | #define THREAD_FSM_H |
| 21 | |
| 22 | #include "mi/mi-common.h" /* For enum async_reply_reason. */ |
| 23 | |
| 24 | struct return_value_info; |
| 25 | struct thread_fsm_ops; |
| 26 | |
| 27 | /* A thread finite-state machine structure contains the necessary info |
| 28 | and callbacks to manage the state machine protocol of a thread's |
| 29 | execution command. */ |
| 30 | |
| 31 | struct thread_fsm |
| 32 | { |
| 33 | explicit thread_fsm (struct interp *cmd_interp) |
| 34 | : command_interp (cmd_interp) |
| 35 | { |
| 36 | } |
| 37 | |
| 38 | /* The destructor. This should simply free heap allocated data |
| 39 | structures. Cleaning up target resources (like, e.g., |
| 40 | breakpoints) should be done in the clean_up method. */ |
| 41 | virtual ~thread_fsm () = default; |
| 42 | |
| 43 | DISABLE_COPY_AND_ASSIGN (thread_fsm); |
| 44 | |
| 45 | /* Called to clean up target resources after the FSM. E.g., if the |
| 46 | FSM created internal breakpoints, this is where they should be |
| 47 | deleted. */ |
| 48 | virtual void clean_up (struct thread_info *thread) |
| 49 | { |
| 50 | } |
| 51 | |
| 52 | /* Called after handle_inferior_event decides the target is done |
| 53 | (that is, after stop_waiting). The FSM is given a chance to |
| 54 | decide whether the command is done and thus the target should |
| 55 | stop, or whether there's still more to do and thus the thread |
| 56 | should be re-resumed. This is a good place to cache target data |
| 57 | too. For example, the "finish" command saves the just-finished |
| 58 | function's return value here. */ |
| 59 | virtual bool should_stop (struct thread_info *thread) = 0; |
| 60 | |
| 61 | /* If this FSM saved a function's return value, you can use this |
| 62 | method to retrieve it. Otherwise, this returns NULL. */ |
| 63 | virtual struct return_value_info *return_value () |
| 64 | { |
| 65 | return nullptr; |
| 66 | } |
| 67 | |
| 68 | enum async_reply_reason async_reply_reason () |
| 69 | { |
| 70 | /* If we didn't finish, then the stop reason must come from |
| 71 | elsewhere. E.g., a breakpoint hit or a signal intercepted. */ |
| 72 | gdb_assert (finished_p ()); |
| 73 | return do_async_reply_reason (); |
| 74 | } |
| 75 | |
| 76 | /* Whether the stop should be notified to the user/frontend. */ |
| 77 | virtual bool should_notify_stop () |
| 78 | { |
| 79 | return true; |
| 80 | } |
| 81 | |
| 82 | void set_finished () |
| 83 | { |
| 84 | finished = true; |
| 85 | } |
| 86 | |
| 87 | bool finished_p () const |
| 88 | { |
| 89 | return finished; |
| 90 | } |
| 91 | |
| 92 | /* The interpreter that issued the execution command that caused |
| 93 | this thread to resume. If the top level interpreter is MI/async, |
| 94 | and the execution command was a CLI command (next/step/etc.), |
| 95 | we'll want to print stop event output to the MI console channel |
| 96 | (the stepped-to line, etc.), as if the user entered the execution |
| 97 | command on a real GDB console. */ |
| 98 | struct interp *command_interp = nullptr; |
| 99 | |
| 100 | protected: |
| 101 | |
| 102 | /* Whether the FSM is done successfully. */ |
| 103 | bool finished = false; |
| 104 | |
| 105 | /* The async_reply_reason that is broadcast to MI clients if this |
| 106 | FSM finishes successfully. */ |
| 107 | virtual enum async_reply_reason do_async_reply_reason () |
| 108 | { |
| 109 | gdb_assert_not_reached (_("should not call async_reply_reason here")); |
| 110 | } |
| 111 | }; |
| 112 | |
| 113 | #endif /* THREAD_FSM_H */ |