gdbthread.h revision 1.3
1/* Multi-process/thread control defs for GDB, the GNU debugger. 2 Copyright (C) 1987-2015 Free Software Foundation, Inc. 3 Contributed by Lynx Real-Time Systems, Inc. Los Gatos, CA. 4 5 6 This file is part of GDB. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 20 21#ifndef GDBTHREAD_H 22#define GDBTHREAD_H 23 24struct symtab; 25 26#include "breakpoint.h" 27#include "frame.h" 28#include "ui-out.h" 29#include "inferior.h" 30#include "btrace.h" 31#include "common/vec.h" 32 33/* Frontend view of the thread state. Possible extensions: stepping, 34 finishing, until(ling),... */ 35enum thread_state 36{ 37 THREAD_STOPPED, 38 THREAD_RUNNING, 39 THREAD_EXITED, 40}; 41 42/* Inferior thread specific part of `struct infcall_control_state'. 43 44 Inferior process counterpart is `struct inferior_control_state'. */ 45 46struct thread_control_state 47{ 48 /* User/external stepping state. */ 49 50 /* Step-resume or longjmp-resume breakpoint. */ 51 struct breakpoint *step_resume_breakpoint; 52 53 /* Exception-resume breakpoint. */ 54 struct breakpoint *exception_resume_breakpoint; 55 56 /* Breakpoints used for software single stepping. Plural, because 57 it may have multiple locations. E.g., if stepping over a 58 conditional branch instruction we can't decode the condition for, 59 we'll need to put a breakpoint at the branch destination, and 60 another at the instruction after the branch. */ 61 struct breakpoint *single_step_breakpoints; 62 63 /* Range to single step within. 64 65 If this is nonzero, respond to a single-step signal by continuing 66 to step if the pc is in this range. 67 68 If step_range_start and step_range_end are both 1, it means to 69 step for a single instruction (FIXME: it might clean up 70 wait_for_inferior in a minor way if this were changed to the 71 address of the instruction and that address plus one. But maybe 72 not). */ 73 CORE_ADDR step_range_start; /* Inclusive */ 74 CORE_ADDR step_range_end; /* Exclusive */ 75 76 /* If GDB issues a target step request, and this is nonzero, the 77 target should single-step this thread once, and then continue 78 single-stepping it without GDB core involvement as long as the 79 thread stops in the step range above. If this is zero, the 80 target should ignore the step range, and only issue one single 81 step. */ 82 int may_range_step; 83 84 /* Stack frame address as of when stepping command was issued. 85 This is how we know when we step into a subroutine call, and how 86 to set the frame for the breakpoint used to step out. */ 87 struct frame_id step_frame_id; 88 89 /* Similarly, the frame ID of the underlying stack frame (skipping 90 any inlined frames). */ 91 struct frame_id step_stack_frame_id; 92 93 /* Nonzero if we are presently stepping over a breakpoint. 94 95 If we hit a breakpoint or watchpoint, and then continue, we need 96 to single step the current thread with breakpoints disabled, to 97 avoid hitting the same breakpoint or watchpoint again. And we 98 should step just a single thread and keep other threads stopped, 99 so that other threads don't miss breakpoints while they are 100 removed. 101 102 So, this variable simultaneously means that we need to single 103 step the current thread, keep other threads stopped, and that 104 breakpoints should be removed while we step. 105 106 This variable is set either: 107 - in proceed, when we resume inferior on user's explicit request 108 - in keep_going, if handle_inferior_event decides we need to 109 step over breakpoint. 110 111 The variable is cleared in normal_stop. The proceed calls 112 wait_for_inferior, which calls handle_inferior_event in a loop, 113 and until wait_for_inferior exits, this variable is changed only 114 by keep_going. */ 115 int trap_expected; 116 117 /* Nonzero if the thread is being proceeded for a "finish" command 118 or a similar situation when stop_registers should be saved. */ 119 int proceed_to_finish; 120 121 /* Nonzero if the thread is being proceeded for an inferior function 122 call. */ 123 int in_infcall; 124 125 enum step_over_calls_kind step_over_calls; 126 127 /* Nonzero if stopped due to a step command. */ 128 int stop_step; 129 130 /* Chain containing status of breakpoint(s) the thread stopped 131 at. */ 132 bpstat stop_bpstat; 133 134 /* The interpreter that issued the execution command. NULL if the 135 thread was resumed as a result of a command applied to some other 136 thread (e.g., "next" with scheduler-locking off). */ 137 struct interp *command_interp; 138}; 139 140/* Inferior thread specific part of `struct infcall_suspend_state'. 141 142 Inferior process counterpart is `struct inferior_suspend_state'. */ 143 144struct thread_suspend_state 145{ 146 /* Last signal that the inferior received (why it stopped). When 147 the thread is resumed, this signal is delivered. Note: the 148 target should not check whether the signal is in pass state, 149 because the signal may have been explicitly passed with the 150 "signal" command, which overrides "handle nopass". If the signal 151 should be suppressed, the core will take care of clearing this 152 before the target is resumed. */ 153 enum gdb_signal stop_signal; 154}; 155 156typedef struct value *value_ptr; 157DEF_VEC_P (value_ptr); 158typedef VEC (value_ptr) value_vec; 159 160struct thread_info 161{ 162 struct thread_info *next; 163 ptid_t ptid; /* "Actual process id"; 164 In fact, this may be overloaded with 165 kernel thread id, etc. */ 166 int num; /* Convenient handle (GDB thread id) */ 167 168 /* The name of the thread, as specified by the user. This is NULL 169 if the thread does not have a user-given name. */ 170 char *name; 171 172 /* Non-zero means the thread is executing. Note: this is different 173 from saying that there is an active target and we are stopped at 174 a breakpoint, for instance. This is a real indicator whether the 175 thread is off and running. */ 176 int executing; 177 178 /* Frontend view of the thread state. Note that the THREAD_RUNNING/ 179 THREAD_STOPPED states are different from EXECUTING. When the 180 thread is stopped internally while handling an internal event, 181 like a software single-step breakpoint, EXECUTING will be false, 182 but STATE will still be THREAD_RUNNING. */ 183 enum thread_state state; 184 185 /* If this is > 0, then it means there's code out there that relies 186 on this thread being listed. Don't delete it from the lists even 187 if we detect it exiting. */ 188 int refcount; 189 190 /* State of GDB control of inferior thread execution. 191 See `struct thread_control_state'. */ 192 struct thread_control_state control; 193 194 /* State of inferior thread to restore after GDB is done with an inferior 195 call. See `struct thread_suspend_state'. */ 196 struct thread_suspend_state suspend; 197 198 int current_line; 199 struct symtab *current_symtab; 200 201 /* Internal stepping state. */ 202 203 /* Record the pc of the thread the last time it stopped. This is 204 maintained by proceed and keep_going, and used in 205 adjust_pc_after_break to distinguish a hardware single-step 206 SIGTRAP from a breakpoint SIGTRAP. */ 207 CORE_ADDR prev_pc; 208 209 /* Did we set the thread stepping a breakpoint instruction? This is 210 used in conjunction with PREV_PC to decide whether to adjust the 211 PC. */ 212 int stepped_breakpoint; 213 214 /* Should we step over breakpoint next time keep_going is called? */ 215 int stepping_over_breakpoint; 216 217 /* Should we step over a watchpoint next time keep_going is called? 218 This is needed on targets with non-continuable, non-steppable 219 watchpoints. */ 220 int stepping_over_watchpoint; 221 222 /* Set to TRUE if we should finish single-stepping over a breakpoint 223 after hitting the current step-resume breakpoint. The context here 224 is that GDB is to do `next' or `step' while signal arrives. 225 When stepping over a breakpoint and signal arrives, GDB will attempt 226 to skip signal handler, so it inserts a step_resume_breakpoint at the 227 signal return address, and resume inferior. 228 step_after_step_resume_breakpoint is set to TRUE at this moment in 229 order to keep GDB in mind that there is still a breakpoint to step over 230 when GDB gets back SIGTRAP from step_resume_breakpoint. */ 231 int step_after_step_resume_breakpoint; 232 233 /* Per-thread command support. */ 234 235 /* Pointer to what is left to do for an execution command after the 236 target stops. Used only in asynchronous mode, by targets that 237 support async execution. Several execution commands use it. */ 238 struct continuation *continuations; 239 240 /* Similar to the above, but used when a single execution command 241 requires several resume/stop iterations. Used by the step 242 command. */ 243 struct continuation *intermediate_continuations; 244 245 /* If stepping, nonzero means step count is > 1 so don't print frame 246 next time inferior stops if it stops due to stepping. */ 247 int step_multi; 248 249 /* This is used to remember when a fork or vfork event was caught by 250 a catchpoint, and thus the event is to be followed at the next 251 resume of the thread, and not immediately. */ 252 struct target_waitstatus pending_follow; 253 254 /* True if this thread has been explicitly requested to stop. */ 255 int stop_requested; 256 257 /* The initiating frame of a nexting operation, used for deciding 258 which exceptions to intercept. If it is null_frame_id no 259 bp_longjmp or bp_exception but longjmp has been caught just for 260 bp_longjmp_call_dummy. */ 261 struct frame_id initiating_frame; 262 263 /* Private data used by the target vector implementation. */ 264 struct private_thread_info *private; 265 266 /* Function that is called to free PRIVATE. If this is NULL, then 267 xfree will be called on PRIVATE. */ 268 void (*private_dtor) (struct private_thread_info *); 269 270 /* Branch trace information for this thread. */ 271 struct btrace_thread_info btrace; 272 273 /* Flag which indicates that the stack temporaries should be stored while 274 evaluating expressions. */ 275 int stack_temporaries_enabled; 276 277 /* Values that are stored as temporaries on stack while evaluating 278 expressions. */ 279 value_vec *stack_temporaries; 280}; 281 282/* Create an empty thread list, or empty the existing one. */ 283extern void init_thread_list (void); 284 285/* Add a thread to the thread list, print a message 286 that a new thread is found, and return the pointer to 287 the new thread. Caller my use this pointer to 288 initialize the private thread data. */ 289extern struct thread_info *add_thread (ptid_t ptid); 290 291/* Same as add_thread, but does not print a message 292 about new thread. */ 293extern struct thread_info *add_thread_silent (ptid_t ptid); 294 295/* Same as add_thread, and sets the private info. */ 296extern struct thread_info *add_thread_with_info (ptid_t ptid, 297 struct private_thread_info *); 298 299/* Delete an existing thread list entry. */ 300extern void delete_thread (ptid_t); 301 302/* Delete an existing thread list entry, and be quiet about it. Used 303 after the process this thread having belonged to having already 304 exited, for example. */ 305extern void delete_thread_silent (ptid_t); 306 307/* Delete a step_resume_breakpoint from the thread database. */ 308extern void delete_step_resume_breakpoint (struct thread_info *); 309 310/* Delete an exception_resume_breakpoint from the thread database. */ 311extern void delete_exception_resume_breakpoint (struct thread_info *); 312 313/* Delete the single-step breakpoints of thread TP, if any. */ 314extern void delete_single_step_breakpoints (struct thread_info *tp); 315 316/* Check if the thread has software single stepping breakpoints 317 set. */ 318extern int thread_has_single_step_breakpoints_set (struct thread_info *tp); 319 320/* Check whether the thread has software single stepping breakpoints 321 set at PC. */ 322extern int thread_has_single_step_breakpoint_here (struct thread_info *tp, 323 struct address_space *aspace, 324 CORE_ADDR addr); 325 326/* Translate the integer thread id (GDB's homegrown id, not the system's) 327 into a "pid" (which may be overloaded with extra thread information). */ 328extern ptid_t thread_id_to_pid (int); 329 330/* Translate a 'pid' (which may be overloaded with extra thread information) 331 into the integer thread id (GDB's homegrown id, not the system's). */ 332extern int pid_to_thread_id (ptid_t ptid); 333 334/* Boolean test for an already-known pid (which may be overloaded with 335 extra thread information). */ 336extern int in_thread_list (ptid_t ptid); 337 338/* Boolean test for an already-known thread id (GDB's homegrown id, 339 not the system's). */ 340extern int valid_thread_id (int thread); 341 342/* Search function to lookup a thread by 'pid'. */ 343extern struct thread_info *find_thread_ptid (ptid_t ptid); 344 345/* Find thread by GDB user-visible thread number. */ 346struct thread_info *find_thread_id (int num); 347 348/* Finds the first thread of the inferior given by PID. If PID is -1, 349 returns the first thread in the list. */ 350struct thread_info *first_thread_of_process (int pid); 351 352/* Returns any thread of process PID, giving preference to the current 353 thread. */ 354extern struct thread_info *any_thread_of_process (int pid); 355 356/* Returns any non-exited thread of process PID, giving preference to 357 the current thread, and to not executing threads. */ 358extern struct thread_info *any_live_thread_of_process (int pid); 359 360/* Change the ptid of thread OLD_PTID to NEW_PTID. */ 361void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid); 362 363/* Iterator function to call a user-provided callback function 364 once for each known thread. */ 365typedef int (*thread_callback_func) (struct thread_info *, void *); 366extern struct thread_info *iterate_over_threads (thread_callback_func, void *); 367 368/* Traverse all threads, except those that have THREAD_EXITED 369 state. */ 370 371#define ALL_NON_EXITED_THREADS(T) \ 372 for (T = thread_list; T; T = T->next) \ 373 if ((T)->state != THREAD_EXITED) 374 375/* Like ALL_NON_EXITED_THREADS, but allows deleting the currently 376 iterated thread. */ 377#define ALL_NON_EXITED_THREADS_SAFE(T, TMP) \ 378 for ((T) = thread_list; \ 379 (T) != NULL ? ((TMP) = (T)->next, 1): 0; \ 380 (T) = (TMP)) \ 381 if ((T)->state != THREAD_EXITED) 382 383extern int thread_count (void); 384 385/* Switch from one thread to another. */ 386extern void switch_to_thread (ptid_t ptid); 387 388/* Marks thread PTID is running, or stopped. 389 If PTID is minus_one_ptid, marks all threads. */ 390extern void set_running (ptid_t ptid, int running); 391 392/* Marks or clears thread(s) PTID as having been requested to stop. 393 If PTID is MINUS_ONE_PTID, applies to all threads. If 394 ptid_is_pid(PTID) is true, applies to all threads of the process 395 pointed at by PTID. If STOP, then the THREAD_STOP_REQUESTED 396 observer is called with PTID as argument. */ 397extern void set_stop_requested (ptid_t ptid, int stop); 398 399/* NOTE: Since the thread state is not a boolean, most times, you do 400 not want to check it with negation. If you really want to check if 401 the thread is stopped, 402 403 use (good): 404 405 if (is_stopped (ptid)) 406 407 instead of (bad): 408 409 if (!is_running (ptid)) 410 411 The latter also returns true on exited threads, most likelly not 412 what you want. */ 413 414/* Reports if in the frontend's perpective, thread PTID is running. */ 415extern int is_running (ptid_t ptid); 416 417/* Is this thread listed, but known to have exited? We keep it listed 418 (but not visible) until it's safe to delete. */ 419extern int is_exited (ptid_t ptid); 420 421/* In the frontend's perpective, is this thread stopped? */ 422extern int is_stopped (ptid_t ptid); 423 424/* Marks thread PTID as executing, or not. If PTID is minus_one_ptid, 425 marks all threads. 426 427 Note that this is different from the running state. See the 428 description of state and executing fields of struct 429 thread_info. */ 430extern void set_executing (ptid_t ptid, int executing); 431 432/* Reports if thread PTID is executing. */ 433extern int is_executing (ptid_t ptid); 434 435/* True if any (known or unknown) thread is or may be executing. */ 436extern int threads_are_executing (void); 437 438/* Merge the executing property of thread PTID over to its thread 439 state property (frontend running/stopped view). 440 441 "not executing" -> "stopped" 442 "executing" -> "running" 443 "exited" -> "exited" 444 445 If PTID is minus_one_ptid, go over all threads. 446 447 Notifications are only emitted if the thread state did change. */ 448extern void finish_thread_state (ptid_t ptid); 449 450/* Same as FINISH_THREAD_STATE, but with an interface suitable to be 451 registered as a cleanup. PTID_P points to the ptid_t that is 452 passed to FINISH_THREAD_STATE. */ 453extern void finish_thread_state_cleanup (void *ptid_p); 454 455/* Commands with a prefix of `thread'. */ 456extern struct cmd_list_element *thread_cmd_list; 457 458/* Print notices on thread events (attach, detach, etc.), set with 459 `set print thread-events'. */ 460extern int print_thread_events; 461 462extern void print_thread_info (struct ui_out *uiout, char *threads, 463 int pid); 464 465extern struct cleanup *make_cleanup_restore_current_thread (void); 466 467/* Returns a pointer into the thread_info corresponding to 468 INFERIOR_PTID. INFERIOR_PTID *must* be in the thread list. */ 469extern struct thread_info* inferior_thread (void); 470 471extern void update_thread_list (void); 472 473/* Delete any thread the target says is no longer alive. */ 474 475extern void prune_threads (void); 476 477/* Return true if PC is in the stepping range of THREAD. */ 478 479int pc_in_thread_step_range (CORE_ADDR pc, struct thread_info *thread); 480 481extern struct cleanup *enable_thread_stack_temporaries (ptid_t ptid); 482 483extern int thread_stack_temporaries_enabled_p (ptid_t ptid); 484 485extern void push_thread_stack_temporary (ptid_t ptid, struct value *v); 486 487extern struct value *get_last_thread_stack_temporary (ptid_t); 488 489extern int value_in_thread_stack_temporaries (struct value *, ptid_t); 490 491extern struct thread_info *thread_list; 492 493#endif /* GDBTHREAD_H */ 494