Commit | Line | Data |
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036b1ba8 JB |
1 | /* Ada Ravenscar thread support. |
2 | ||
ecd75fc8 | 3 | Copyright (C) 2004-2014 Free Software Foundation, Inc. |
036b1ba8 JB |
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 "gdbcore.h" | |
22 | #include "gdbthread.h" | |
23 | #include "ada-lang.h" | |
24 | #include "target.h" | |
25 | #include "inferior.h" | |
26 | #include "command.h" | |
27 | #include "ravenscar-thread.h" | |
28 | #include "observer.h" | |
0e9f083f | 29 | #include <string.h> |
036b1ba8 JB |
30 | #include "gdbcmd.h" |
31 | #include "top.h" | |
32 | #include "regcache.h" | |
33 | ||
34 | /* If non-null, ravenscar task support is enabled. */ | |
35 | static int ravenscar_task_support = 1; | |
36 | ||
036b1ba8 JB |
37 | /* This module's target-specific operations. */ |
38 | static struct target_ops ravenscar_ops; | |
39 | ||
40 | /* Some base target uses a special value for the null PID (exempli gratia | |
41 | remote). */ | |
42 | static ptid_t base_magic_null_ptid; | |
43 | ||
44 | /* Ptid of the inferior as seen by the process stratum. */ | |
45 | static ptid_t base_ptid; | |
46 | ||
7f39f34a | 47 | static const char running_thread_name[] = "__gnat_running_thread_table"; |
036b1ba8 JB |
48 | |
49 | static const char known_tasks_name[] = "system__tasking__debug__known_tasks"; | |
6040a59d | 50 | static const char first_task_name[] = "system__tasking__debug__first_task"; |
036b1ba8 | 51 | |
0df8b418 MS |
52 | static const char ravenscar_runtime_initializer[] = |
53 | "system__bb__threads__initialize"; | |
036b1ba8 | 54 | |
036b1ba8 JB |
55 | static void ravenscar_find_new_threads (struct target_ops *ops); |
56 | static ptid_t ravenscar_running_thread (void); | |
57 | static char *ravenscar_extra_thread_info (struct thread_info *tp); | |
58 | static int ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid); | |
59 | static void ravenscar_fetch_registers (struct target_ops *ops, | |
60 | struct regcache *regcache, int regnum); | |
61 | static void ravenscar_store_registers (struct target_ops *ops, | |
62 | struct regcache *regcache, int regnum); | |
f32dbf8c MM |
63 | static void ravenscar_prepare_to_store (struct target_ops *self, |
64 | struct regcache *regcache); | |
036b1ba8 | 65 | static void ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step, |
2ea28649 | 66 | enum gdb_signal siggnal); |
036b1ba8 JB |
67 | static void ravenscar_mourn_inferior (struct target_ops *ops); |
68 | static void ravenscar_update_inferior_ptid (void); | |
69 | static int has_ravenscar_runtime (void); | |
70 | static int ravenscar_runtime_initialized (void); | |
71 | static void ravenscar_inferior_created (struct target_ops *target, | |
72 | int from_tty); | |
73 | ||
74 | /* Fetch the ravenscar running thread from target memory and | |
75 | update inferior_ptid accordingly. */ | |
76 | ||
77 | static void | |
78 | ravenscar_update_inferior_ptid (void) | |
79 | { | |
80 | base_ptid = inferior_ptid; | |
81 | ||
82 | /* If the runtime has not been initialized yet, the inferior_ptid is | |
83 | the only ptid that there is. */ | |
84 | if (!ravenscar_runtime_initialized ()) | |
85 | return; | |
86 | ||
87 | /* Make sure we set base_ptid before calling ravenscar_running_thread | |
88 | as the latter relies on it. */ | |
89 | inferior_ptid = ravenscar_running_thread (); | |
90 | gdb_assert (!ptid_equal (inferior_ptid, null_ptid)); | |
91 | ||
92 | /* The running thread may not have been added to | |
93 | system.tasking.debug's list yet; so ravenscar_find_new_threads | |
94 | may not always add it to the thread list. Add it here. */ | |
95 | if (!find_thread_ptid (inferior_ptid)) | |
96 | add_thread (inferior_ptid); | |
97 | } | |
98 | ||
7f39f34a JB |
99 | /* The Ravenscar Runtime exports a symbol which contains the ID of |
100 | the thread that is currently running. Try to locate that symbol | |
101 | and return its associated minimal symbol. | |
102 | Return NULL if not found. */ | |
103 | ||
104 | static struct minimal_symbol * | |
105 | get_running_thread_msymbol (void) | |
106 | { | |
107 | struct minimal_symbol *msym; | |
108 | ||
109 | msym = lookup_minimal_symbol (running_thread_name, NULL, NULL); | |
110 | if (!msym) | |
111 | /* Older versions of the GNAT runtime were using a different | |
112 | (less ideal) name for the symbol where the active thread ID | |
113 | is stored. If we couldn't find the symbol using the latest | |
114 | name, then try the old one. */ | |
115 | msym = lookup_minimal_symbol ("running_thread", NULL, NULL); | |
116 | ||
117 | return msym; | |
118 | } | |
119 | ||
036b1ba8 JB |
120 | /* Return True if the Ada Ravenscar run-time can be found in the |
121 | application. */ | |
122 | ||
123 | static int | |
124 | has_ravenscar_runtime (void) | |
125 | { | |
126 | struct minimal_symbol *msym_ravenscar_runtime_initializer = | |
127 | lookup_minimal_symbol (ravenscar_runtime_initializer, NULL, NULL); | |
128 | struct minimal_symbol *msym_known_tasks = | |
129 | lookup_minimal_symbol (known_tasks_name, NULL, NULL); | |
6040a59d JB |
130 | struct minimal_symbol *msym_first_task = |
131 | lookup_minimal_symbol (first_task_name, NULL, NULL); | |
7f39f34a | 132 | struct minimal_symbol *msym_running_thread = get_running_thread_msymbol (); |
036b1ba8 JB |
133 | |
134 | return (msym_ravenscar_runtime_initializer | |
6040a59d | 135 | && (msym_known_tasks || msym_first_task) |
036b1ba8 JB |
136 | && msym_running_thread); |
137 | } | |
138 | ||
139 | /* Return True if the Ada Ravenscar run-time can be found in the | |
140 | application, and if it has been initialized on target. */ | |
141 | ||
142 | static int | |
143 | ravenscar_runtime_initialized (void) | |
144 | { | |
145 | return (!(ptid_equal (ravenscar_running_thread (), null_ptid))); | |
146 | } | |
147 | ||
7f39f34a JB |
148 | /* Return the ID of the thread that is currently running. |
149 | Return 0 if the ID could not be determined. */ | |
036b1ba8 JB |
150 | |
151 | static CORE_ADDR | |
7f39f34a | 152 | get_running_thread_id (void) |
036b1ba8 | 153 | { |
7f39f34a | 154 | const struct minimal_symbol *object_msym = get_running_thread_msymbol (); |
036b1ba8 JB |
155 | int object_size; |
156 | int buf_size; | |
948f8e3d | 157 | gdb_byte *buf; |
036b1ba8 JB |
158 | CORE_ADDR object_addr; |
159 | struct type *builtin_type_void_data_ptr = | |
f5656ead | 160 | builtin_type (target_gdbarch ())->builtin_data_ptr; |
036b1ba8 JB |
161 | |
162 | if (!object_msym) | |
163 | return 0; | |
164 | ||
165 | object_addr = SYMBOL_VALUE_ADDRESS (object_msym); | |
166 | object_size = TYPE_LENGTH (builtin_type_void_data_ptr); | |
167 | buf_size = object_size; | |
168 | buf = alloca (buf_size); | |
169 | read_memory (object_addr, buf, buf_size); | |
170 | return extract_typed_address (buf, builtin_type_void_data_ptr); | |
171 | } | |
172 | ||
036b1ba8 JB |
173 | static void |
174 | ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step, | |
2ea28649 | 175 | enum gdb_signal siggnal) |
036b1ba8 JB |
176 | { |
177 | struct target_ops *beneath = find_target_beneath (ops); | |
178 | ||
179 | inferior_ptid = base_ptid; | |
180 | beneath->to_resume (beneath, base_ptid, step, siggnal); | |
181 | } | |
182 | ||
183 | static ptid_t | |
184 | ravenscar_wait (struct target_ops *ops, ptid_t ptid, | |
185 | struct target_waitstatus *status, | |
186 | int options) | |
187 | { | |
188 | struct target_ops *beneath = find_target_beneath (ops); | |
189 | ||
190 | inferior_ptid = base_ptid; | |
191 | beneath->to_wait (beneath, base_ptid, status, 0); | |
bed0c243 JB |
192 | /* Find any new threads that might have been created, and update |
193 | inferior_ptid to the active thread. | |
194 | ||
195 | Only do it if the program is still alive, though. Otherwise, | |
196 | this causes problems when debugging through the remote protocol, | |
197 | because we might try switching threads (and thus sending packets) | |
198 | after the remote has disconnected. */ | |
199 | if (status->kind != TARGET_WAITKIND_EXITED | |
200 | && status->kind != TARGET_WAITKIND_SIGNALLED) | |
201 | { | |
202 | ravenscar_find_new_threads (ops); | |
203 | ravenscar_update_inferior_ptid (); | |
204 | } | |
036b1ba8 JB |
205 | return inferior_ptid; |
206 | } | |
207 | ||
208 | /* Add the thread associated to the given TASK to the thread list | |
209 | (if the thread has already been added, this is a no-op). */ | |
210 | ||
211 | static void | |
212 | ravenscar_add_thread (struct ada_task_info *task) | |
213 | { | |
214 | if (find_thread_ptid (task->ptid) == NULL) | |
215 | add_thread (task->ptid); | |
216 | } | |
217 | ||
218 | static void | |
219 | ravenscar_find_new_threads (struct target_ops *ops) | |
220 | { | |
79779fa9 | 221 | ada_build_task_list (); |
036b1ba8 JB |
222 | |
223 | /* Do not clear the thread list before adding the Ada task, to keep | |
224 | the thread that the process stratum has included into it | |
225 | (base_ptid) and the running thread, that may not have been included | |
226 | to system.tasking.debug's list yet. */ | |
227 | ||
228 | iterate_over_live_ada_tasks (ravenscar_add_thread); | |
229 | } | |
230 | ||
231 | static ptid_t | |
232 | ravenscar_running_thread (void) | |
233 | { | |
7f39f34a | 234 | CORE_ADDR tid = get_running_thread_id (); |
036b1ba8 JB |
235 | |
236 | if (tid == 0) | |
237 | return null_ptid; | |
238 | else | |
239 | return ptid_build (ptid_get_pid (base_ptid), 0, tid); | |
240 | } | |
241 | ||
242 | static char * | |
243 | ravenscar_extra_thread_info (struct thread_info *tp) | |
244 | { | |
245 | return "Ravenscar task"; | |
246 | } | |
247 | ||
248 | static int | |
249 | ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid) | |
250 | { | |
251 | /* Ravenscar tasks are non-terminating. */ | |
252 | return 1; | |
253 | } | |
254 | ||
255 | static char * | |
256 | ravenscar_pid_to_str (struct target_ops *ops, ptid_t ptid) | |
257 | { | |
258 | static char buf[30]; | |
259 | ||
260 | snprintf (buf, sizeof (buf), "Thread %#x", (int) ptid_get_tid (ptid)); | |
261 | return buf; | |
262 | } | |
263 | ||
264 | static void | |
265 | ravenscar_fetch_registers (struct target_ops *ops, | |
266 | struct regcache *regcache, int regnum) | |
267 | { | |
268 | struct target_ops *beneath = find_target_beneath (ops); | |
269 | ||
270 | if (!ravenscar_runtime_initialized () | |
271 | || ptid_equal (inferior_ptid, base_magic_null_ptid) | |
272 | || ptid_equal (inferior_ptid, ravenscar_running_thread ())) | |
273 | beneath->to_fetch_registers (beneath, regcache, regnum); | |
274 | else | |
7e35103a JB |
275 | { |
276 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
277 | struct ravenscar_arch_ops *arch_ops | |
278 | = gdbarch_ravenscar_ops (gdbarch); | |
279 | ||
280 | arch_ops->to_fetch_registers (regcache, regnum); | |
281 | } | |
036b1ba8 JB |
282 | } |
283 | ||
284 | static void | |
285 | ravenscar_store_registers (struct target_ops *ops, | |
286 | struct regcache *regcache, int regnum) | |
287 | { | |
288 | struct target_ops *beneath = find_target_beneath (ops); | |
289 | ||
290 | if (!ravenscar_runtime_initialized () | |
291 | || ptid_equal (inferior_ptid, base_magic_null_ptid) | |
292 | || ptid_equal (inferior_ptid, ravenscar_running_thread ())) | |
293 | beneath->to_store_registers (beneath, regcache, regnum); | |
294 | else | |
7e35103a JB |
295 | { |
296 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
297 | struct ravenscar_arch_ops *arch_ops | |
298 | = gdbarch_ravenscar_ops (gdbarch); | |
299 | ||
300 | arch_ops->to_store_registers (regcache, regnum); | |
301 | } | |
036b1ba8 JB |
302 | } |
303 | ||
304 | static void | |
f32dbf8c MM |
305 | ravenscar_prepare_to_store (struct target_ops *self, |
306 | struct regcache *regcache) | |
036b1ba8 JB |
307 | { |
308 | struct target_ops *beneath = find_target_beneath (&ravenscar_ops); | |
309 | ||
310 | if (!ravenscar_runtime_initialized () | |
311 | || ptid_equal (inferior_ptid, base_magic_null_ptid) | |
312 | || ptid_equal (inferior_ptid, ravenscar_running_thread ())) | |
f32dbf8c | 313 | beneath->to_prepare_to_store (beneath, regcache); |
036b1ba8 | 314 | else |
7e35103a JB |
315 | { |
316 | struct gdbarch *gdbarch = get_regcache_arch (regcache); | |
317 | struct ravenscar_arch_ops *arch_ops | |
318 | = gdbarch_ravenscar_ops (gdbarch); | |
319 | ||
320 | arch_ops->to_prepare_to_store (regcache); | |
321 | } | |
036b1ba8 JB |
322 | } |
323 | ||
324 | static void | |
325 | ravenscar_mourn_inferior (struct target_ops *ops) | |
326 | { | |
327 | struct target_ops *beneath = find_target_beneath (&ravenscar_ops); | |
328 | ||
329 | base_ptid = null_ptid; | |
330 | beneath->to_mourn_inferior (beneath); | |
331 | unpush_target (&ravenscar_ops); | |
332 | } | |
333 | ||
334 | /* Observer on inferior_created: push ravenscar thread stratum if needed. */ | |
335 | ||
336 | static void | |
337 | ravenscar_inferior_created (struct target_ops *target, int from_tty) | |
338 | { | |
7e35103a JB |
339 | struct ravenscar_arch_ops *ops; |
340 | ||
341 | if (!ravenscar_task_support | |
342 | || gdbarch_ravenscar_ops (current_inferior ()->gdbarch) == NULL | |
343 | || !has_ravenscar_runtime ()) | |
25abf4de JB |
344 | return; |
345 | ||
346 | base_magic_null_ptid = inferior_ptid; | |
347 | ravenscar_update_inferior_ptid (); | |
348 | push_target (&ravenscar_ops); | |
036b1ba8 JB |
349 | } |
350 | ||
036b1ba8 JB |
351 | static ptid_t |
352 | ravenscar_get_ada_task_ptid (long lwp, long thread) | |
353 | { | |
354 | return ptid_build (ptid_get_pid (base_ptid), 0, thread); | |
355 | } | |
356 | ||
357 | static void | |
358 | init_ravenscar_thread_ops (void) | |
359 | { | |
360 | ravenscar_ops.to_shortname = "ravenscar"; | |
361 | ravenscar_ops.to_longname = "Ravenscar tasks."; | |
362 | ravenscar_ops.to_doc = "Ravenscar tasks support."; | |
036b1ba8 JB |
363 | ravenscar_ops.to_resume = ravenscar_resume; |
364 | ravenscar_ops.to_wait = ravenscar_wait; | |
365 | ravenscar_ops.to_fetch_registers = ravenscar_fetch_registers; | |
366 | ravenscar_ops.to_store_registers = ravenscar_store_registers; | |
367 | ravenscar_ops.to_prepare_to_store = ravenscar_prepare_to_store; | |
368 | ravenscar_ops.to_thread_alive = ravenscar_thread_alive; | |
369 | ravenscar_ops.to_find_new_threads = ravenscar_find_new_threads; | |
370 | ravenscar_ops.to_pid_to_str = ravenscar_pid_to_str; | |
371 | ravenscar_ops.to_extra_thread_info = ravenscar_extra_thread_info; | |
372 | ravenscar_ops.to_get_ada_task_ptid = ravenscar_get_ada_task_ptid; | |
373 | ravenscar_ops.to_mourn_inferior = ravenscar_mourn_inferior; | |
374 | ravenscar_ops.to_has_all_memory = default_child_has_all_memory; | |
375 | ravenscar_ops.to_has_memory = default_child_has_memory; | |
376 | ravenscar_ops.to_has_stack = default_child_has_stack; | |
377 | ravenscar_ops.to_has_registers = default_child_has_registers; | |
378 | ravenscar_ops.to_has_execution = default_child_has_execution; | |
379 | ravenscar_ops.to_stratum = thread_stratum; | |
380 | ravenscar_ops.to_magic = OPS_MAGIC; | |
381 | } | |
382 | ||
383 | /* Command-list for the "set/show ravenscar" prefix command. */ | |
384 | static struct cmd_list_element *set_ravenscar_list; | |
385 | static struct cmd_list_element *show_ravenscar_list; | |
386 | ||
387 | /* Implement the "set ravenscar" prefix command. */ | |
388 | ||
389 | static void | |
390 | set_ravenscar_command (char *arg, int from_tty) | |
391 | { | |
392 | printf_unfiltered (_(\ | |
393 | "\"set ravenscar\" must be followed by the name of a setting.\n")); | |
394 | help_list (set_ravenscar_list, "set ravenscar ", -1, gdb_stdout); | |
395 | } | |
396 | ||
397 | /* Implement the "show ravenscar" prefix command. */ | |
398 | ||
399 | static void | |
400 | show_ravenscar_command (char *args, int from_tty) | |
401 | { | |
402 | cmd_show_list (show_ravenscar_list, from_tty, ""); | |
403 | } | |
404 | ||
405 | /* Implement the "show ravenscar task-switching" command. */ | |
406 | ||
407 | static void | |
408 | show_ravenscar_task_switching_command (struct ui_file *file, int from_tty, | |
409 | struct cmd_list_element *c, | |
410 | const char *value) | |
411 | { | |
412 | if (ravenscar_task_support) | |
413 | fprintf_filtered (file, _("\ | |
b64edec4 | 414 | Support for Ravenscar task/thread switching is enabled\n")); |
036b1ba8 JB |
415 | else |
416 | fprintf_filtered (file, _("\ | |
b64edec4 | 417 | Support for Ravenscar task/thread switching is disabled\n")); |
036b1ba8 JB |
418 | } |
419 | ||
8d037db9 JB |
420 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
421 | extern void _initialize_ravenscar (void); | |
422 | ||
036b1ba8 JB |
423 | /* Module startup initialization function, automagically called by |
424 | init.c. */ | |
425 | ||
426 | void | |
427 | _initialize_ravenscar (void) | |
428 | { | |
429 | init_ravenscar_thread_ops (); | |
430 | base_ptid = null_ptid; | |
431 | ||
432 | /* Notice when the inferior is created in order to push the | |
433 | ravenscar ops if needed. */ | |
434 | observer_attach_inferior_created (ravenscar_inferior_created); | |
435 | ||
12070676 | 436 | complete_target_initialization (&ravenscar_ops); |
036b1ba8 JB |
437 | |
438 | add_prefix_cmd ("ravenscar", no_class, set_ravenscar_command, | |
439 | _("Prefix command for changing Ravenscar-specific settings"), | |
440 | &set_ravenscar_list, "set ravenscar ", 0, &setlist); | |
441 | ||
442 | add_prefix_cmd ("ravenscar", no_class, show_ravenscar_command, | |
443 | _("Prefix command for showing Ravenscar-specific settings"), | |
04f9d4d0 | 444 | &show_ravenscar_list, "show ravenscar ", 0, &showlist); |
036b1ba8 JB |
445 | |
446 | add_setshow_boolean_cmd ("task-switching", class_obscure, | |
447 | &ravenscar_task_support, _("\ | |
448 | Enable or disable support for GNAT Ravenscar tasks"), _("\ | |
449 | Show whether support for GNAT Ravenscar tasks is enabled"), | |
450 | _("\ | |
451 | Enable or disable support for task/thread switching with the GNAT\n\ | |
452 | Ravenscar run-time library for bareboard configuration."), | |
453 | NULL, show_ravenscar_task_switching_command, | |
454 | &set_ravenscar_list, &show_ravenscar_list); | |
455 | } |