gdb/ravenscar-thread.c

   1 /* Ada Ravenscar thread support.
   2
   3    Copyright (C) 2004-2017 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 #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"
  29 #include "gdbcmd.h"
  30 #include "top.h"
  31 #include "regcache.h"
  32 #include "objfiles.h"
  33
  34 /* This module provides support for "Ravenscar" tasks (Ada) when
  35    debugging on bare-metal targets.
  36
  37    The typical situation is when debugging a bare-metal target over
  38    the remote protocol. In that situation, the system does not know
  39    about high-level comcepts such as threads, only about some code
  40    running on one or more CPUs. And since the remote protocol does not
  41    provide any handling for CPUs, the de facto standard for handling
  42    them is to have one thread per CPU, where the thread's ptid has
  43    its lwp field set to the CPU number (eg: 1 for the first CPU,
  44    2 for the second one, etc).  This module will make that assumption.
  45
  46    This module then creates and maintains the list of threads based
  47    on the list of Ada tasks, with one thread per Ada tasks. The convention
  48    is that threads corresponding to the CPUs (see assumption above)
  49    have a ptid_t of the form (PID, LWP, 0), which threads corresponding
  50    to our Ada tasks have a ptid_t of the form (PID, 0, TID) where TID
  51    is the Ada task's ID as extracted from Ada runtime information.
  52
  53    Switching to a given Ada tasks (or its underlying thread) is performed
  54    by fetching the registers of that tasks from the memory area where
  55    the registers were saved.  For any of the other operations, the
  56    operation is performed by first finding the CPU on which the task
  57    is running, switching to its corresponding ptid, and then performing
  58    the operation on that ptid using the target beneath us.  */
  59
  60 /* If non-null, ravenscar task support is enabled.  */
  61 static int ravenscar_task_support = 1;
  62
  63 /* This module's target-specific operations.  */
  64 static struct target_ops ravenscar_ops;
  65
  66 /* PTID of the last thread that received an event.
  67    This can be useful to determine the associated task that received
  68    the event, to make it the current task.  */
  69 static ptid_t base_ptid;
  70
  71 static const char running_thread_name[] = "__gnat_running_thread_table";
  72
  73 static const char known_tasks_name[] = "system__tasking__debug__known_tasks";
  74 static const char first_task_name[] = "system__tasking__debug__first_task";
  75
  76 static const char ravenscar_runtime_initializer[] =
  77   "system__bb__threads__initialize";
  78
  79 static void ravenscar_update_thread_list (struct target_ops *ops);
  80 static ptid_t ravenscar_active_task (int cpu);
  81 static const char *ravenscar_extra_thread_info (struct target_ops *self,
  82                                                 struct thread_info *tp);
  83 static int ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid);
  84 static void ravenscar_fetch_registers (struct target_ops *ops,
  85                                        struct regcache *regcache, int regnum);
  86 static void ravenscar_store_registers (struct target_ops *ops,
  87                                        struct regcache *regcache, int regnum);
  88 static void ravenscar_prepare_to_store (struct target_ops *self,
  89                                         struct regcache *regcache);
  90 static void ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step,
  91                               enum gdb_signal siggnal);
  92 static void ravenscar_mourn_inferior (struct target_ops *ops);
  93 static void ravenscar_update_inferior_ptid (void);
  94 static int has_ravenscar_runtime (void);
  95 static int ravenscar_runtime_initialized (void);
  96 static void ravenscar_inferior_created (struct target_ops *target,
  97                                         int from_tty);
  98
  99 /* Return nonzero iff PTID corresponds to a ravenscar task.  */
 100
 101 static int
 102 is_ravenscar_task (ptid_t ptid)
 103 {
 104   /* By construction, ravenscar tasks have their LWP set to zero.
 105      Also make sure that the TID is nonzero, as some remotes, when
 106      asked for the list of threads, will return the first thread
 107      as having its TID set to zero.  For instance, TSIM version
 108      2.0.48 for LEON3 sends 'm0' as a reply to the 'qfThreadInfo'
 109      query, which the remote protocol layer then treats as a thread
 110      whose TID is 0.  This is obviously not a ravenscar task.  */
 111   return ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) != 0;
 112 }
 113
 114 /* Given PTID, which can be either a ravenscar task or a CPU thread,
 115    return which CPU that ptid is running on.
 116
 117    This assume that PTID is a valid ptid_t.  Otherwise, a gdb_assert
 118    will be triggered.  */
 119
 120 static int
 121 ravenscar_get_thread_base_cpu (ptid_t ptid)
 122 {
 123   int base_cpu;
 124
 125   if (is_ravenscar_task (ptid))
 126     {
 127       struct ada_task_info *task_info = ada_get_task_info_from_ptid (ptid);
 128
 129       gdb_assert (task_info != NULL);
 130       base_cpu = task_info->base_cpu;
 131     }
 132   else
 133     {
 134       /* We assume that the LWP of the PTID is equal to the CPU number.  */
 135       base_cpu = ptid_get_lwp (ptid);
 136     }
 137
 138   return base_cpu;
 139 }
 140
 141 /* Given a ravenscar task (identified by its ptid_t PTID), return nonzero
 142    if this task is the currently active task on the cpu that task is
 143    running on.
 144
 145    In other words, this function determine which CPU this task is
 146    currently running on, and then return nonzero if the CPU in question
 147    is executing the code for that task.  If that's the case, then
 148    that task's registers are in the CPU bank.  Otherwise, the task
 149    is currently suspended, and its registers have been saved in memory.  */
 150
 151 static int
 152 ravenscar_task_is_currently_active (ptid_t ptid)
 153 {
 154   ptid_t active_task_ptid
 155     = ravenscar_active_task (ravenscar_get_thread_base_cpu (ptid));
 156
 157   return ptid_equal (ptid, active_task_ptid);
 158 }
 159
 160 /* Return the CPU thread (as a ptid_t) on which the given ravenscar
 161    task is running.
 162
 163    This is the thread that corresponds to the CPU on which the task
 164    is running.  */
 165
 166 static ptid_t
 167 get_base_thread_from_ravenscar_task (ptid_t ptid)
 168 {
 169   int base_cpu;
 170
 171   if (!is_ravenscar_task (ptid))
 172     return ptid;
 173
 174   base_cpu = ravenscar_get_thread_base_cpu (ptid);
 175   return ptid_build (ptid_get_pid (ptid), base_cpu, 0);
 176 }
 177
 178 /* Fetch the ravenscar running thread from target memory and
 179    update inferior_ptid accordingly.  */
 180
 181 static void
 182 ravenscar_update_inferior_ptid (void)
 183 {
 184   int base_cpu;
 185
 186   base_ptid = inferior_ptid;
 187
 188   gdb_assert (!is_ravenscar_task (inferior_ptid));
 189   base_cpu = ravenscar_get_thread_base_cpu (base_ptid);
 190
 191   /* If the runtime has not been initialized yet, the inferior_ptid is
 192      the only ptid that there is.  */
 193   if (!ravenscar_runtime_initialized ())
 194     return;
 195
 196   /* Make sure we set base_ptid before calling ravenscar_active_task
 197      as the latter relies on it.  */
 198   inferior_ptid = ravenscar_active_task (base_cpu);
 199   gdb_assert (!ptid_equal (inferior_ptid, null_ptid));
 200
 201   /* The running thread may not have been added to
 202      system.tasking.debug's list yet; so ravenscar_update_thread_list
 203      may not always add it to the thread list.  Add it here.  */
 204   if (!find_thread_ptid (inferior_ptid))
 205     add_thread (inferior_ptid);
 206 }
 207
 208 /* The Ravenscar Runtime exports a symbol which contains the ID of
 209    the thread that is currently running.  Try to locate that symbol
 210    and return its associated minimal symbol.
 211    Return NULL if not found.  */
 212
 213 static struct bound_minimal_symbol
 214 get_running_thread_msymbol (void)
 215 {
 216   struct bound_minimal_symbol msym;
 217
 218   msym = lookup_minimal_symbol (running_thread_name, NULL, NULL);
 219   if (!msym.minsym)
 220     /* Older versions of the GNAT runtime were using a different
 221        (less ideal) name for the symbol where the active thread ID
 222        is stored.  If we couldn't find the symbol using the latest
 223        name, then try the old one.  */
 224     msym = lookup_minimal_symbol ("running_thread", NULL, NULL);
 225
 226   return msym;
 227 }
 228
 229 /* Return True if the Ada Ravenscar run-time can be found in the
 230    application.  */
 231
 232 static int
 233 has_ravenscar_runtime (void)
 234 {
 235   struct bound_minimal_symbol msym_ravenscar_runtime_initializer =
 236     lookup_minimal_symbol (ravenscar_runtime_initializer, NULL, NULL);
 237   struct bound_minimal_symbol msym_known_tasks =
 238     lookup_minimal_symbol (known_tasks_name, NULL, NULL);
 239   struct bound_minimal_symbol msym_first_task =
 240     lookup_minimal_symbol (first_task_name, NULL, NULL);
 241   struct bound_minimal_symbol msym_running_thread
 242     = get_running_thread_msymbol ();
 243
 244   return (msym_ravenscar_runtime_initializer.minsym
 245           && (msym_known_tasks.minsym || msym_first_task.minsym)
 246           && msym_running_thread.minsym);
 247 }
 248
 249 /* Return True if the Ada Ravenscar run-time can be found in the
 250    application, and if it has been initialized on target.  */
 251
 252 static int
 253 ravenscar_runtime_initialized (void)
 254 {
 255   return (!(ptid_equal (ravenscar_active_task (1), null_ptid)));
 256 }
 257
 258 /* Return the ID of the thread that is currently running.
 259    Return 0 if the ID could not be determined.  */
 260
 261 static CORE_ADDR
 262 get_running_thread_id (int cpu)
 263 {
 264   struct bound_minimal_symbol object_msym = get_running_thread_msymbol ();
 265   int object_size;
 266   int buf_size;
 267   gdb_byte *buf;
 268   CORE_ADDR object_addr;
 269   struct type *builtin_type_void_data_ptr =
 270     builtin_type (target_gdbarch ())->builtin_data_ptr;
 271
 272   if (!object_msym.minsym)
 273     return 0;
 274
 275   object_size = TYPE_LENGTH (builtin_type_void_data_ptr);
 276   object_addr = (BMSYMBOL_VALUE_ADDRESS (object_msym)
 277                  + (cpu - 1) * object_size);
 278   buf_size = object_size;
 279   buf = (gdb_byte *) alloca (buf_size);
 280   read_memory (object_addr, buf, buf_size);
 281   return extract_typed_address (buf, builtin_type_void_data_ptr);
 282 }
 283
 284 static void
 285 ravenscar_resume (struct target_ops *ops, ptid_t ptid, int step,
 286                   enum gdb_signal siggnal)
 287 {
 288   struct target_ops *beneath = find_target_beneath (ops);
 289
 290   inferior_ptid = base_ptid;
 291   beneath->to_resume (beneath, base_ptid, step, siggnal);
 292 }
 293
 294 static ptid_t
 295 ravenscar_wait (struct target_ops *ops, ptid_t ptid,
 296                 struct target_waitstatus *status,
 297                 int options)
 298 {
 299   struct target_ops *beneath = find_target_beneath (ops);
 300   ptid_t event_ptid;
 301
 302   inferior_ptid = base_ptid;
 303   event_ptid = beneath->to_wait (beneath, base_ptid, status, 0);
 304   /* Find any new threads that might have been created, and update
 305      inferior_ptid to the active thread.
 306
 307      Only do it if the program is still alive, though.  Otherwise,
 308      this causes problems when debugging through the remote protocol,
 309      because we might try switching threads (and thus sending packets)
 310      after the remote has disconnected.  */
 311   if (status->kind != TARGET_WAITKIND_EXITED
 312       && status->kind != TARGET_WAITKIND_SIGNALLED)
 313     {
 314       inferior_ptid = event_ptid;
 315       ravenscar_update_thread_list (ops);
 316       ravenscar_update_inferior_ptid ();
 317     }
 318   return inferior_ptid;
 319 }
 320
 321 /* Add the thread associated to the given TASK to the thread list
 322    (if the thread has already been added, this is a no-op).  */
 323
 324 static void
 325 ravenscar_add_thread (struct ada_task_info *task)
 326 {
 327   if (find_thread_ptid (task->ptid) == NULL)
 328     add_thread (task->ptid);
 329 }
 330
 331 static void
 332 ravenscar_update_thread_list (struct target_ops *ops)
 333 {
 334   ada_build_task_list ();
 335
 336   /* Do not clear the thread list before adding the Ada task, to keep
 337      the thread that the process stratum has included into it
 338      (base_ptid) and the running thread, that may not have been included
 339      to system.tasking.debug's list yet.  */
 340
 341   iterate_over_live_ada_tasks (ravenscar_add_thread);
 342 }
 343
 344 static ptid_t
 345 ravenscar_active_task (int cpu)
 346 {
 347   CORE_ADDR tid = get_running_thread_id (cpu);
 348
 349   if (tid == 0)
 350     return null_ptid;
 351   else
 352     return ptid_build (ptid_get_pid (base_ptid), 0, tid);
 353 }
 354
 355 static const char *
 356 ravenscar_extra_thread_info (struct target_ops *self, struct thread_info *tp)
 357 {
 358   return "Ravenscar task";
 359 }
 360
 361 static int
 362 ravenscar_thread_alive (struct target_ops *ops, ptid_t ptid)
 363 {
 364   /* Ravenscar tasks are non-terminating.  */
 365   return 1;
 366 }
 367
 368 static const char *
 369 ravenscar_pid_to_str (struct target_ops *ops, ptid_t ptid)
 370 {
 371   static char buf[30];
 372
 373   snprintf (buf, sizeof (buf), "Thread %#x", (int) ptid_get_tid (ptid));
 374   return buf;
 375 }
 376
 377 static void
 378 ravenscar_fetch_registers (struct target_ops *ops,
 379                            struct regcache *regcache, int regnum)
 380 {
 381   struct target_ops *beneath = find_target_beneath (ops);
 382   ptid_t ptid = regcache_get_ptid (regcache);
 383
 384   if (ravenscar_runtime_initialized ()
 385       && is_ravenscar_task (ptid)
 386       && !ravenscar_task_is_currently_active (ptid))
 387     {
 388       struct gdbarch *gdbarch = regcache->arch ();
 389       struct ravenscar_arch_ops *arch_ops
 390         = gdbarch_ravenscar_ops (gdbarch);
 391
 392       arch_ops->to_fetch_registers (regcache, regnum);
 393     }
 394   else
 395     beneath->to_fetch_registers (beneath, regcache, regnum);
 396 }
 397
 398 static void
 399 ravenscar_store_registers (struct target_ops *ops,
 400                            struct regcache *regcache, int regnum)
 401 {
 402   struct target_ops *beneath = find_target_beneath (ops);
 403   ptid_t ptid = regcache_get_ptid (regcache);
 404
 405   if (ravenscar_runtime_initialized ()
 406       && is_ravenscar_task (ptid)
 407       && !ravenscar_task_is_currently_active (ptid))
 408     {
 409       struct gdbarch *gdbarch = regcache->arch ();
 410       struct ravenscar_arch_ops *arch_ops
 411         = gdbarch_ravenscar_ops (gdbarch);
 412
 413       arch_ops->to_store_registers (regcache, regnum);
 414     }
 415   else
 416     beneath->to_store_registers (beneath, regcache, regnum);
 417 }
 418
 419 static void
 420 ravenscar_prepare_to_store (struct target_ops *self,
 421                             struct regcache *regcache)
 422 {
 423   struct target_ops *beneath = find_target_beneath (self);
 424   ptid_t ptid = regcache_get_ptid (regcache);
 425
 426   if (ravenscar_runtime_initialized ()
 427       && is_ravenscar_task (ptid)
 428       && !ravenscar_task_is_currently_active (ptid))
 429     {
 430       struct gdbarch *gdbarch = regcache->arch ();
 431       struct ravenscar_arch_ops *arch_ops
 432         = gdbarch_ravenscar_ops (gdbarch);
 433
 434       arch_ops->to_prepare_to_store (regcache);
 435     }
 436   else
 437     beneath->to_prepare_to_store (beneath, regcache);
 438 }
 439
 440 /* Implement the to_stopped_by_sw_breakpoint target_ops "method".  */
 441
 442 static int
 443 ravenscar_stopped_by_sw_breakpoint (struct target_ops *ops)
 444 {
 445   ptid_t saved_ptid = inferior_ptid;
 446   struct target_ops *beneath = find_target_beneath (ops);
 447   int result;
 448
 449   inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
 450   result = beneath->to_stopped_by_sw_breakpoint (beneath);
 451   inferior_ptid = saved_ptid;
 452   return result;
 453 }
 454
 455 /* Implement the to_stopped_by_hw_breakpoint target_ops "method".  */
 456
 457 static int
 458 ravenscar_stopped_by_hw_breakpoint (struct target_ops *ops)
 459 {
 460   ptid_t saved_ptid = inferior_ptid;
 461   struct target_ops *beneath = find_target_beneath (ops);
 462   int result;
 463
 464   inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
 465   result = beneath->to_stopped_by_hw_breakpoint (beneath);
 466   inferior_ptid = saved_ptid;
 467   return result;
 468 }
 469
 470 /* Implement the to_stopped_by_watchpoint target_ops "method".  */
 471
 472 static int
 473 ravenscar_stopped_by_watchpoint (struct target_ops *ops)
 474 {
 475   ptid_t saved_ptid = inferior_ptid;
 476   struct target_ops *beneath = find_target_beneath (ops);
 477   int result;
 478
 479   inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
 480   result = beneath->to_stopped_by_watchpoint (beneath);
 481   inferior_ptid = saved_ptid;
 482   return result;
 483 }
 484
 485 /* Implement the to_stopped_data_address target_ops "method".  */
 486
 487 static int
 488 ravenscar_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
 489 {
 490   ptid_t saved_ptid = inferior_ptid;
 491   struct target_ops *beneath = find_target_beneath (ops);
 492   int result;
 493
 494   inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
 495   result = beneath->to_stopped_data_address (beneath, addr_p);
 496   inferior_ptid = saved_ptid;
 497   return result;
 498 }
 499
 500 static void
 501 ravenscar_mourn_inferior (struct target_ops *ops)
 502 {
 503   struct target_ops *beneath = find_target_beneath (ops);
 504
 505   base_ptid = null_ptid;
 506   beneath->to_mourn_inferior (beneath);
 507   unpush_target (&ravenscar_ops);
 508 }
 509
 510 /* Implement the to_core_of_thread target_ops "method".  */
 511
 512 static int
 513 ravenscar_core_of_thread (struct target_ops *ops, ptid_t ptid)
 514 {
 515   ptid_t saved_ptid = inferior_ptid;
 516   struct target_ops *beneath = find_target_beneath (ops);
 517   int result;
 518
 519   inferior_ptid = get_base_thread_from_ravenscar_task (saved_ptid);
 520   result = beneath->to_core_of_thread (beneath, inferior_ptid);
 521   inferior_ptid = saved_ptid;
 522   return result;
 523 }
 524
 525 /* Observer on inferior_created: push ravenscar thread stratum if needed.  */
 526
 527 static void
 528 ravenscar_inferior_created (struct target_ops *target, int from_tty)
 529 {
 530   const char *err_msg;
 531
 532   if (!ravenscar_task_support
 533       || gdbarch_ravenscar_ops (target_gdbarch ()) == NULL
 534       || !has_ravenscar_runtime ())
 535     return;
 536
 537   err_msg = ada_get_tcb_types_info ();
 538   if (err_msg != NULL)
 539     {
 540       warning (_("%s. Task/thread support disabled."), err_msg);
 541       return;
 542     }
 543
 544   ravenscar_update_inferior_ptid ();
 545   push_target (&ravenscar_ops);
 546 }
 547
 548 static ptid_t
 549 ravenscar_get_ada_task_ptid (struct target_ops *self, long lwp, long thread)
 550 {
 551   return ptid_build (ptid_get_pid (base_ptid), 0, thread);
 552 }
 553
 554 static void
 555 init_ravenscar_thread_ops (void)
 556 {
 557   ravenscar_ops.to_shortname = "ravenscar";
 558   ravenscar_ops.to_longname = "Ravenscar tasks.";
 559   ravenscar_ops.to_doc = "Ravenscar tasks support.";
 560   ravenscar_ops.to_resume = ravenscar_resume;
 561   ravenscar_ops.to_wait = ravenscar_wait;
 562   ravenscar_ops.to_fetch_registers = ravenscar_fetch_registers;
 563   ravenscar_ops.to_store_registers = ravenscar_store_registers;
 564   ravenscar_ops.to_prepare_to_store = ravenscar_prepare_to_store;
 565   ravenscar_ops.to_stopped_by_sw_breakpoint
 566     = ravenscar_stopped_by_sw_breakpoint;
 567   ravenscar_ops.to_stopped_by_hw_breakpoint
 568     = ravenscar_stopped_by_hw_breakpoint;
 569   ravenscar_ops.to_stopped_by_watchpoint = ravenscar_stopped_by_watchpoint;
 570   ravenscar_ops.to_stopped_data_address = ravenscar_stopped_data_address;
 571   ravenscar_ops.to_thread_alive = ravenscar_thread_alive;
 572   ravenscar_ops.to_update_thread_list = ravenscar_update_thread_list;
 573   ravenscar_ops.to_pid_to_str = ravenscar_pid_to_str;
 574   ravenscar_ops.to_extra_thread_info = ravenscar_extra_thread_info;
 575   ravenscar_ops.to_get_ada_task_ptid = ravenscar_get_ada_task_ptid;
 576   ravenscar_ops.to_mourn_inferior = ravenscar_mourn_inferior;
 577   ravenscar_ops.to_has_all_memory = default_child_has_all_memory;
 578   ravenscar_ops.to_has_memory = default_child_has_memory;
 579   ravenscar_ops.to_has_stack = default_child_has_stack;
 580   ravenscar_ops.to_has_registers = default_child_has_registers;
 581   ravenscar_ops.to_has_execution = default_child_has_execution;
 582   ravenscar_ops.to_stratum = thread_stratum;
 583   ravenscar_ops.to_core_of_thread = ravenscar_core_of_thread;
 584   ravenscar_ops.to_magic = OPS_MAGIC;
 585 }
 586
 587 /* Command-list for the "set/show ravenscar" prefix command.  */
 588 static struct cmd_list_element *set_ravenscar_list;
 589 static struct cmd_list_element *show_ravenscar_list;
 590
 591 /* Implement the "set ravenscar" prefix command.  */
 592
 593 static void
 594 set_ravenscar_command (const char *arg, int from_tty)
 595 {
 596   printf_unfiltered (_(\
 597 "\"set ravenscar\" must be followed by the name of a setting.\n"));
 598   help_list (set_ravenscar_list, "set ravenscar ", all_commands, gdb_stdout);
 599 }
 600
 601 /* Implement the "show ravenscar" prefix command.  */
 602
 603 static void
 604 show_ravenscar_command (const char *args, int from_tty)
 605 {
 606   cmd_show_list (show_ravenscar_list, from_tty, "");
 607 }
 608
 609 /* Implement the "show ravenscar task-switching" command.  */
 610
 611 static void
 612 show_ravenscar_task_switching_command (struct ui_file *file, int from_tty,
 613                                        struct cmd_list_element *c,
 614                                        const char *value)
 615 {
 616   if (ravenscar_task_support)
 617     fprintf_filtered (file, _("\
 618 Support for Ravenscar task/thread switching is enabled\n"));
 619   else
 620     fprintf_filtered (file, _("\
 621 Support for Ravenscar task/thread switching is disabled\n"));
 622 }
 623
 624 /* Module startup initialization function, automagically called by
 625    init.c.  */
 626
 627 void
 628 _initialize_ravenscar (void)
 629 {
 630   init_ravenscar_thread_ops ();
 631   base_ptid = null_ptid;
 632
 633   /* Notice when the inferior is created in order to push the
 634      ravenscar ops if needed.  */
 635   observer_attach_inferior_created (ravenscar_inferior_created);
 636
 637   complete_target_initialization (&ravenscar_ops);
 638
 639   add_prefix_cmd ("ravenscar", no_class, set_ravenscar_command,
 640                   _("Prefix command for changing Ravenscar-specific settings"),
 641                   &set_ravenscar_list, "set ravenscar ", 0, &setlist);
 642
 643   add_prefix_cmd ("ravenscar", no_class, show_ravenscar_command,
 644                   _("Prefix command for showing Ravenscar-specific settings"),
 645                   &show_ravenscar_list, "show ravenscar ", 0, &showlist);
 646
 647   add_setshow_boolean_cmd ("task-switching", class_obscure,
 648                            &ravenscar_task_support, _("\
 649 Enable or disable support for GNAT Ravenscar tasks"), _("\
 650 Show whether support for GNAT Ravenscar tasks is enabled"),
 651                            _("\
 652 Enable or disable support for task/thread switching with the GNAT\n\
 653 Ravenscar run-time library for bareboard configuration."),
 654                            NULL, show_ravenscar_task_switching_command,
 655                            &set_ravenscar_list, &show_ravenscar_list);
 656 }