1 /* Observers
2 
3    Copyright (C) 2016-2024 Free Software Foundation, Inc.
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 #ifndef OBSERVABLE_H
21 #define OBSERVABLE_H
22 
23 #include "gdbsupport/observable.h"
24 #include "target/waitstatus.h"
25 
26 struct bpstat;
27 struct solib;
28 struct objfile;
29 struct thread_info;
30 struct inferior;
31 struct process_stratum_target;
32 struct target_ops;
33 struct trace_state_variable;
34 struct program_space;
35 
36 namespace gdb
37 {
38 
39 namespace observers
40 {
41 
42 /* The inferior has stopped for real.  The BS argument describes the
43    breakpoints were are stopped at, if any.  Second argument
44    PRINT_FRAME non-zero means display the location where the
45    inferior has stopped.
46 
47    gdb notifies all normal_stop observers when the inferior execution
48    has just stopped, the associated messages and annotations have been
49    printed, and the control is about to be returned to the user.
50 
51    Note that the normal_stop notification is not emitted when the
52    execution stops due to a breakpoint, and this breakpoint has a
53    condition that is not met.  If the breakpoint has any associated
54    commands list, the commands are executed after the notification is
55    emitted.  */
56 extern observable<struct bpstat */* bs */, int /* print_frame */> normal_stop;
57 
58 /* The inferior was stopped by a signal.  */
59 extern observable<enum gdb_signal /* siggnal */> signal_received;
60 
61 /* The target's register contents have changed.  */
62 extern observable<struct target_ops */* target */> target_changed;
63 
64 /* The executable being debugged by GDB in PSPACE has changed: The user
65    decided to debug a different program, or the program he was debugging
66    has been modified since being loaded by the debugger (by being
67    recompiled, for instance).  The path to the new executable can be found
68    by examining PSPACE->exec_filename.
69 
70    When RELOAD is true the path to the executable hasn't changed, but the
71    file does appear to have changed, so GDB reloaded it, e.g. if the user
72    recompiled the executable.  when RELOAD is false then the path to the
73    executable has not changed.  */
74 extern observable<struct program_space */* pspace */,
75                       bool /*reload */> executable_changed;
76 
77 /* gdb has just connected to an inferior.  For 'run', gdb calls this
78    observer while the inferior is still stopped at the entry-point
79    instruction.  For 'attach' and 'core', gdb calls this observer
80    immediately after connecting to the inferior, and before any
81    information on the inferior has been printed.  */
82 extern observable<inferior */* inferior */> inferior_created;
83 
84 /* The inferior EXEC_INF has exec'ed a new executable file.
85 
86    Execution continues in FOLLOW_INF, which may or may not be the same as
87    EXEC_INF, depending on "set follow-exec-mode".  */
88 extern observable<inferior */* exec_inf */, inferior */* follow_inf */>
89     inferior_execd;
90 
91 /* The inferior PARENT_INF has forked.  If we are setting up an inferior for
92    the child (because we follow only the child or we follow both), CHILD_INF
93    is the child inferior.  Otherwise, CHILD_INF is nullptr.
94 
95    FORK_KIND is TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED.  */
96 extern observable<inferior */* parent_inf */, inferior */* child_inf */,
97                       target_waitkind /* fork_kind */> inferior_forked;
98 
99 /* The shared library specified by SOLIB has been loaded.  Note that
100    when gdb calls this observer, the library's symbols probably
101    haven't been loaded yet.  */
102 extern observable<solib &/* solib */> solib_loaded;
103 
104 /* The shared library SOLIB has been unloaded from program space PSPACE.
105    Note  when gdb calls this observer, the library's symbols have not
106    been unloaded yet, and thus are still available.  */
107 extern observable<program_space *, const solib &/* solib */> solib_unloaded;
108 
109 /* The symbol file specified by OBJFILE has been loaded.  */
110 extern observable<struct objfile */* objfile */> new_objfile;
111 
112 /*  All objfiles from PSPACE were removed.  */
113 extern observable<program_space */* pspace */> all_objfiles_removed;
114 
115 /* The object file specified by OBJFILE is about to be freed.  */
116 extern observable<struct objfile */* objfile */> free_objfile;
117 
118 /* The thread specified by T has been created.  */
119 extern observable<struct thread_info */* t */> new_thread;
120 
121 /* The thread specified by T has exited.  EXIT_CODE is the thread's
122    exit code, if available.  The SILENT argument indicates that GDB is
123    removing the thread from its tables without wanting to notify the
124    CLI about it.  */
125 extern observable<thread_info */* t */,
126                       std::optional<ULONGEST> /* exit_code */,
127                       bool /* silent */> thread_exit;
128 
129 /* The thread specified by T has been deleted, with delete_thread.
130    This is called just before the thread_info object is destroyed with
131    operator delete.  */
132 extern observable<thread_info */* t */> thread_deleted;
133 
134 /* An explicit stop request was issued to PTID.  If PTID equals
135    minus_one_ptid, the request applied to all threads.  If
136    ptid_is_pid(PTID) returns true, the request applied to all
137    threads of the process pointed at by PTID.  Otherwise, the
138    request applied to the single thread pointed at by PTID.  */
139 extern observable<ptid_t /* ptid */> thread_stop_requested;
140 
141 /* The target was resumed.  The PTID parameter specifies which
142    thread was resume, and may be RESUME_ALL if all threads are
143    resumed.  */
144 extern observable<ptid_t /* ptid */> target_resumed;
145 
146 /* The target is about to be proceeded.  */
147 extern observable<> about_to_proceed;
148 
149 /* A new breakpoint B has been created.  */
150 extern observable<struct breakpoint */* b */> breakpoint_created;
151 
152 /* A breakpoint has been destroyed.  The argument B is the
153    pointer to the destroyed breakpoint.  */
154 extern observable<struct breakpoint */* b */> breakpoint_deleted;
155 
156 /* A breakpoint has been modified in some way.  The argument B
157    is the modified breakpoint.  */
158 extern observable<struct breakpoint */* b */> breakpoint_modified;
159 
160 /* GDB has instantiated a new architecture, NEWARCH is a pointer to the new
161    architecture.  */
162 extern observable<struct gdbarch */* newarch */> new_architecture;
163 
164 /* The thread's ptid has changed.  The OLD_PTID parameter specifies
165    the old value, and NEW_PTID specifies the new value.  */
166 extern observable<process_stratum_target * /* target */,
167                       ptid_t /* old_ptid */, ptid_t /* new_ptid */>
168   thread_ptid_changed;
169 
170 /* The inferior INF has been added to the list of inferiors.  At
171    this point, it might not be associated with any process.  */
172 extern observable<struct inferior */* inf */> inferior_added;
173 
174 /* The inferior identified by INF has been attached to a
175    process.  */
176 extern observable<struct inferior */* inf */> inferior_appeared;
177 
178 /* Inferior INF is about to be detached.  */
179 extern observable<struct inferior */* inf */> inferior_pre_detach;
180 
181 /* Either the inferior associated with INF has been detached from
182    the process, or the process has exited.  */
183 extern observable<struct inferior */* inf */> inferior_exit;
184 
185 /* The inferior INF has been removed from the list of inferiors.
186    This method is called immediately before freeing INF.  */
187 extern observable<struct inferior */* inf */> inferior_removed;
188 
189 /* The inferior CLONE has been created by cloning INF.  */
190 extern observable<struct inferior */* inf */, struct inferior */* clone */>
191     inferior_cloned;
192 
193 /* Bytes from DATA to DATA + LEN have been written to the inferior
194    at ADDR.  */
195 extern observable<struct inferior */* inferior */, CORE_ADDR /* addr */,
196                       ssize_t /* len */, const bfd_byte */* data */>
197     memory_changed;
198 
199 /* Called before a top-level prompt is displayed.  CURRENT_PROMPT is
200    the current top-level prompt.  */
201 extern observable<const char */* current_prompt */> before_prompt;
202 
203 /* Variable gdb_datadir has been set.  The value may not necessarily
204    change.  */
205 extern observable<> gdb_datadir_changed;
206 
207 /* An inferior function at ADDRESS is about to be called in thread
208    THREAD.  */
209 extern observable<ptid_t /* thread */, CORE_ADDR /* address */>
210     inferior_call_pre;
211 
212 /* The inferior function at ADDRESS has just been called.  This
213    observer is called even if the inferior exits during the call.
214    THREAD is the thread in which the function was called, which may
215    be different from the current thread.  */
216 extern observable<ptid_t /* thread */, CORE_ADDR /* address */>
217     inferior_call_post;
218 
219 /* A register in the inferior has been modified by the gdb user.  */
220 extern observable<const frame_info_ptr &/* frame */, int /* regnum */>
221     register_changed;
222 
223 /* The user-selected inferior, thread and/or frame has changed.  The
224    user_select_what flag specifies if the inferior, thread and/or
225    frame has changed.  */
226 extern observable<user_selected_what /* selection */>
227     user_selected_context_changed;
228 
229 /* This is notified when a styling setting has changed, content may need
230    to be updated based on the new settings.  */
231 extern observable<> styling_changed;
232 
233 /* The CLI's notion of the current source has changed.  This differs
234    from user_selected_context_changed in that it is also set by the
235    "list" command.  */
236 extern observable<> current_source_symtab_and_line_changed;
237 
238 /* Called when GDB is about to exit.  */
239 extern observable<int> gdb_exiting;
240 
241 /* When a connection is removed.  */
242 extern observable<process_stratum_target */* target */> connection_removed;
243 
244 /* About to enter target_wait (). */
245 extern observable <ptid_t /* ptid */> target_pre_wait;
246 
247 /* About to leave target_wait (). */
248 extern observable <ptid_t /* event_ptid */> target_post_wait;
249 
250 /* New program space PSPACE was created.  */
251 extern observable <program_space */* pspace */> new_program_space;
252 
253 /* The program space PSPACE is about to be deleted.  */
254 extern observable <program_space */* pspace */> free_program_space;
255 
256 } /* namespace observers */
257 
258 } /* namespace gdb */
259 
260 #endif /* OBSERVABLE_H */
261