gdb/inferior.h

   1 /* Variables that describe the inferior process running under GDB:
   2    Where it is, why it stopped, and how to step it.
   3
   4    Copyright (C) 1986-2019 Free Software Foundation, Inc.
   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 #if !defined (INFERIOR_H)
  22 #define INFERIOR_H 1
  23
  24 struct target_waitstatus;
  25 struct frame_info;
  26 struct ui_file;
  27 struct type;
  28 struct gdbarch;
  29 struct regcache;
  30 struct ui_out;
  31 struct terminal_info;
  32 struct target_desc_info;
  33 struct continuation;
  34 struct inferior;
  35 struct thread_info;
  36
  37 /* For bpstat.  */
  38 #include "breakpoint.h"
  39
  40 /* For enum gdb_signal.  */
  41 #include "target.h"
  42
  43 /* For struct frame_id.  */
  44 #include "frame.h"
  45
  46 /* For gdb_environ.  */
  47 #include "gdbsupport/environ.h"
  48
  49 #include "progspace.h"
  50 #include "registry.h"
  51
  52 #include "symfile-add-flags.h"
  53 #include "gdbsupport/refcounted-object.h"
  54 #include "gdbsupport/forward-scope-exit.h"
  55
  56 #include "gdbsupport/common-inferior.h"
  57 #include "gdbthread.h"
  58
  59 struct infcall_suspend_state;
  60 struct infcall_control_state;
  61
  62 extern void restore_infcall_suspend_state (struct infcall_suspend_state *);
  63 extern void restore_infcall_control_state (struct infcall_control_state *);
  64
  65 /* A deleter for infcall_suspend_state that calls
  66    restore_infcall_suspend_state.  */
  67 struct infcall_suspend_state_deleter
  68 {
  69   void operator() (struct infcall_suspend_state *state) const
  70   {
  71     try
  72       {
  73         restore_infcall_suspend_state (state);
  74       }
  75     catch (const gdb_exception_error &e)
  76       {
  77         /* If we are restoring the inferior state due to an exception,
  78            some error message will be printed.  So, only warn the user
  79            when we cannot restore during normal execution.  */
  80         if (!std::uncaught_exception ())
  81           warning (_("Failed to restore inferior state: %s"), e.what ());
  82       }
  83   }
  84 };
  85
  86 /* A unique_ptr specialization for infcall_suspend_state.  */
  87 typedef std::unique_ptr<infcall_suspend_state, infcall_suspend_state_deleter>
  88     infcall_suspend_state_up;
  89
  90 extern infcall_suspend_state_up save_infcall_suspend_state ();
  91
  92 /* A deleter for infcall_control_state that calls
  93    restore_infcall_control_state.  */
  94 struct infcall_control_state_deleter
  95 {
  96   void operator() (struct infcall_control_state *state) const
  97   {
  98     restore_infcall_control_state (state);
  99   }
 100 };
 101
 102 /* A unique_ptr specialization for infcall_control_state.  */
 103 typedef std::unique_ptr<infcall_control_state, infcall_control_state_deleter>
 104     infcall_control_state_up;
 105
 106 extern infcall_control_state_up save_infcall_control_state ();
 107
 108 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
 109 extern void discard_infcall_control_state (struct infcall_control_state *);
 110
 111 extern readonly_detached_regcache *
 112   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
 113
 114 extern void set_sigint_trap (void);
 115
 116 extern void clear_sigint_trap (void);
 117
 118 /* Set/get file name for default use for standard in/out in the inferior.  */
 119
 120 extern void set_inferior_io_terminal (const char *terminal_name);
 121 extern const char *get_inferior_io_terminal (void);
 122
 123 /* Collected pid, tid, etc. of the debugged inferior.  When there's
 124    no inferior, inferior_ptid.pid () will be 0.  */
 125
 126 extern ptid_t inferior_ptid;
 127
 128 extern void generic_mourn_inferior (void);
 129
 130 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
 131                                               struct type *type,
 132                                               const gdb_byte *buf);
 133 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
 134                                          struct type *type, gdb_byte *buf,
 135                                          CORE_ADDR addr);
 136 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 137                                             struct type *type,
 138                                             const gdb_byte *buf);
 139 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 140                                        struct type *type, gdb_byte *buf,
 141                                        CORE_ADDR addr);
 142
 143 extern void reopen_exec_file (void);
 144
 145 /* From misc files */
 146
 147 extern void default_print_registers_info (struct gdbarch *gdbarch,
 148                                           struct ui_file *file,
 149                                           struct frame_info *frame,
 150                                           int regnum, int all);
 151
 152 /* Default implementation of gdbarch_print_float_info.  Print
 153    the values of all floating point registers.  */
 154
 155 extern void default_print_float_info (struct gdbarch *gdbarch,
 156                                       struct ui_file *file,
 157                                       struct frame_info *frame,
 158                                       const char *args);
 159
 160 extern void child_terminal_info (struct target_ops *self, const char *, int);
 161
 162 extern void info_terminal_command (char *, int);
 163
 164 extern void child_terminal_ours (struct target_ops *self);
 165
 166 extern void child_terminal_ours_for_output (struct target_ops *self);
 167
 168 extern void child_terminal_inferior (struct target_ops *self);
 169
 170 extern void child_terminal_save_inferior (struct target_ops *self);
 171
 172 extern void child_terminal_init (struct target_ops *self);
 173
 174 extern void child_terminal_init_with_pgrp (int pgrp);
 175
 176 extern void child_pass_ctrlc (struct target_ops *self);
 177
 178 extern void child_interrupt (struct target_ops *self);
 179
 180 /* From fork-child.c */
 181
 182 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 183    This function already calls set_executing.  Return the ptid_t from
 184    STARTUP_INFERIOR.  */
 185 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 186
 187 extern char *construct_inferior_arguments (int, char **);
 188
 189 /* From infcmd.c */
 190
 191 /* Initial inferior setup.  Determines the exec file is not yet known,
 192    takes any necessary post-attaching actions, fetches the target
 193    description and syncs the shared library list.  */
 194
 195 extern void setup_inferior (int from_tty);
 196
 197 extern void post_create_inferior (struct target_ops *, int);
 198
 199 extern void attach_command (const char *, int);
 200
 201 extern const char *get_inferior_args (void);
 202
 203 extern void set_inferior_args (const char *);
 204
 205 extern void set_inferior_args_vector (int, char **);
 206
 207 extern void registers_info (const char *, int);
 208
 209 extern void continue_1 (int all_threads);
 210
 211 extern void interrupt_target_1 (int all_threads);
 212
 213 using delete_longjmp_breakpoint_cleanup
 214   = FORWARD_SCOPE_EXIT (delete_longjmp_breakpoint);
 215
 216 extern void detach_command (const char *, int);
 217
 218 extern void notice_new_inferior (struct thread_info *, int, int);
 219
 220 extern struct value *get_return_value (struct value *function,
 221                                        struct type *value_type);
 222
 223 /* Prepare for execution command.  TARGET is the target that will run
 224    the command.  BACKGROUND determines whether this is a foreground
 225    (synchronous) or background (asynchronous) command.  */
 226
 227 extern void prepare_execution_command (struct target_ops *target,
 228                                        int background);
 229
 230 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 231
 232 extern enum stop_stack_kind stop_stack_dummy;
 233
 234 /* Nonzero if program stopped due to a random (unexpected) signal in
 235    inferior process.  */
 236
 237 extern int stopped_by_random_signal;
 238
 239 /* Print notices on inferior events (attach, detach, etc.), set with
 240    `set print inferior-events'.  */
 241 extern bool print_inferior_events;
 242
 243 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 244    will handle it themselves.  STOP_QUIETLY is used when running in
 245    the shell before the child program has been exec'd and when running
 246    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 247    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 248    except that there is no need to hide a signal.  */
 249
 250 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 251    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 252    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 253    a ptraced process has changed.  Earlier versions of the kernel
 254    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 255    other signal, i.e. it is not muffled.
 256
 257    If the gdb user does a 'continue' after the 'attach', gdb passes
 258    the global variable stop_signal (which stores the signal from the
 259    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 260    problematic, because the kernel doesn't ignore such SIGSTOP
 261    now.  I.e. it is reported back to gdb, which in turn presents it
 262    back to the user.
 263
 264    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 265    gdb to clear the value of stop_signal after the attach, so that it
 266    is not passed back down to the kernel.  */
 267
 268 enum stop_kind
 269   {
 270     NO_STOP_QUIETLY = 0,
 271     STOP_QUIETLY,
 272     STOP_QUIETLY_REMOTE,
 273     STOP_QUIETLY_NO_SIGSTOP
 274   };
 275
 276 \f
 277 /* Possible values for gdbarch_call_dummy_location.  */
 278 #define ON_STACK 1
 279 #define AT_ENTRY_POINT 4
 280
 281 /* Base class for target-specific inferior data.  */
 282
 283 struct private_inferior
 284 {
 285   virtual ~private_inferior () = 0;
 286 };
 287
 288 /* Inferior process specific part of `struct infcall_control_state'.
 289
 290    Inferior thread counterpart is `struct thread_control_state'.  */
 291
 292 struct inferior_control_state
 293 {
 294   inferior_control_state ()
 295     : stop_soon (NO_STOP_QUIETLY)
 296   {
 297   }
 298
 299   explicit inferior_control_state (enum stop_kind when)
 300     : stop_soon (when)
 301   {
 302   }
 303
 304   /* See the definition of stop_kind above.  */
 305   enum stop_kind stop_soon;
 306 };
 307
 308 /* Return a pointer to the current inferior.  */
 309 extern inferior *current_inferior ();
 310
 311 extern void set_current_inferior (inferior *);
 312
 313 /* GDB represents the state of each program execution with an object
 314    called an inferior.  An inferior typically corresponds to a process
 315    but is more general and applies also to targets that do not have a
 316    notion of processes.  Each run of an executable creates a new
 317    inferior, as does each attachment to an existing process.
 318    Inferiors have unique internal identifiers that are different from
 319    target process ids.  Each inferior may in turn have multiple
 320    threads running in it.
 321
 322    Inferiors are intrusively refcounted objects.  Unlike thread
 323    objects, being the user-selected inferior is considered a strong
 324    reference and is thus accounted for in the inferior object's
 325    refcount (see set_current_inferior).  When GDB needs to remember
 326    the selected inferior to later restore it, GDB temporarily bumps
 327    the inferior object's refcount, to prevent something deleting the
 328    inferior object before reverting back (e.g., due to a
 329    "remove-inferiors" command (see
 330    scoped_restore_current_inferior).  All other inferior
 331    references are considered weak references.  Inferiors are always
 332    listed exactly once in the inferior list, so placing an inferior in
 333    the inferior list is an implicit, not counted strong reference.  */
 334
 335 class inferior : public refcounted_object
 336 {
 337 public:
 338   explicit inferior (int pid);
 339   ~inferior ();
 340
 341   /* Returns true if we can delete this inferior.  */
 342   bool deletable () const { return refcount () == 0; }
 343
 344   /* Pointer to next inferior in singly-linked list of inferiors.  */
 345   struct inferior *next = NULL;
 346
 347   /* This inferior's thread list.  */
 348   thread_info *thread_list = nullptr;
 349
 350   /* Returns a range adapter covering the inferior's threads,
 351      including exited threads.  Used like this:
 352
 353        for (thread_info *thr : inf->threads ())
 354          { .... }
 355   */
 356   inf_threads_range threads ()
 357   { return inf_threads_range (this->thread_list); }
 358
 359   /* Returns a range adapter covering the inferior's non-exited
 360      threads.  Used like this:
 361
 362        for (thread_info *thr : inf->non_exited_threads ())
 363          { .... }
 364   */
 365   inf_non_exited_threads_range non_exited_threads ()
 366   { return inf_non_exited_threads_range (this->thread_list); }
 367
 368   /* Like inferior::threads(), but returns a range adapter that can be
 369      used with range-for, safely.  I.e., it is safe to delete the
 370      currently-iterated thread, like this:
 371
 372      for (thread_info *t : inf->threads_safe ())
 373        if (some_condition ())
 374          delete f;
 375   */
 376   inline safe_inf_threads_range threads_safe ()
 377   { return safe_inf_threads_range (this->thread_list); }
 378
 379   /* Convenient handle (GDB inferior id).  Unique across all
 380      inferiors.  */
 381   int num = 0;
 382
 383   /* Actual target inferior id, usually, a process id.  This matches
 384      the ptid_t.pid member of threads of this inferior.  */
 385   int pid = 0;
 386   /* True if the PID was actually faked by GDB.  */
 387   bool fake_pid_p = false;
 388
 389   /* The highest thread number this inferior ever had.  */
 390   int highest_thread_num = 0;
 391
 392   /* State of GDB control of inferior process execution.
 393      See `struct inferior_control_state'.  */
 394   inferior_control_state control;
 395
 396   /* True if this was an auto-created inferior, e.g. created from
 397      following a fork; false, if this inferior was manually added by
 398      the user, and we should not attempt to prune it
 399      automatically.  */
 400   bool removable = false;
 401
 402   /* The address space bound to this inferior.  */
 403   struct address_space *aspace = NULL;
 404
 405   /* The program space bound to this inferior.  */
 406   struct program_space *pspace = NULL;
 407
 408   /* The arguments string to use when running.  */
 409   char *args = NULL;
 410
 411   /* The size of elements in argv.  */
 412   int argc = 0;
 413
 414   /* The vector version of arguments.  If ARGC is nonzero,
 415      then we must compute ARGS from this (via the target).
 416      This is always coming from main's argv and therefore
 417      should never be freed.  */
 418   char **argv = NULL;
 419
 420   /* The current working directory that will be used when starting
 421      this inferior.  */
 422   gdb::unique_xmalloc_ptr<char> cwd;
 423
 424   /* The name of terminal device to use for I/O.  */
 425   char *terminal = NULL;
 426
 427   /* The terminal state as set by the last target_terminal::terminal_*
 428      call.  */
 429   target_terminal_state terminal_state = target_terminal_state::is_ours;
 430
 431   /* Environment to use for running inferior,
 432      in format described in environ.h.  */
 433   gdb_environ environment;
 434
 435   /* True if this child process was attached rather than forked.  */
 436   bool attach_flag = false;
 437
 438   /* If this inferior is a vfork child, then this is the pointer to
 439      its vfork parent, if GDB is still attached to it.  */
 440   inferior *vfork_parent = NULL;
 441
 442   /* If this process is a vfork parent, this is the pointer to the
 443      child.  Since a vfork parent is left frozen by the kernel until
 444      the child execs or exits, a process can only have one vfork child
 445      at a given time.  */
 446   inferior *vfork_child = NULL;
 447
 448   /* True if this inferior should be detached when it's vfork sibling
 449      exits or execs.  */
 450   bool pending_detach = false;
 451
 452   /* True if this inferior is a vfork parent waiting for a vfork child
 453      not under our control to be done with the shared memory region,
 454      either by exiting or execing.  */
 455   bool waiting_for_vfork_done = false;
 456
 457   /* True if we're in the process of detaching from this inferior.  */
 458   bool detaching = false;
 459
 460   /* What is left to do for an execution command after any thread of
 461      this inferior stops.  For continuations associated with a
 462      specific thread, see `struct thread_info'.  */
 463   continuation *continuations = NULL;
 464
 465   /* True if setup_inferior wasn't called for this inferior yet.
 466      Until that is done, we must not access inferior memory or
 467      registers, as we haven't determined the target
 468      architecture/description.  */
 469   bool needs_setup = false;
 470
 471   /* Private data used by the target vector implementation.  */
 472   std::unique_ptr<private_inferior> priv;
 473
 474   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 475      In this case, the EXIT_CODE field is also valid.  */
 476   bool has_exit_code = false;
 477   LONGEST exit_code = 0;
 478
 479   /* Default flags to pass to the symbol reading functions.  These are
 480      used whenever a new objfile is created.  */
 481   symfile_add_flags symfile_flags = 0;
 482
 483   /* Info about an inferior's target description (if it's fetched; the
 484      user supplied description's filename, if any; etc.).  */
 485   target_desc_info *tdesc_info = NULL;
 486
 487   /* The architecture associated with the inferior through the
 488      connection to the target.
 489
 490      The architecture vector provides some information that is really
 491      a property of the inferior, accessed through a particular target:
 492      ptrace operations; the layout of certain RSP packets; the
 493      solib_ops vector; etc.  To differentiate architecture accesses to
 494      per-inferior/target properties from
 495      per-thread/per-frame/per-objfile properties, accesses to
 496      per-inferior/target properties should be made through
 497      this gdbarch.  */
 498   struct gdbarch *gdbarch = NULL;
 499
 500   /* Data related to displaced stepping.  */
 501   displaced_step_inferior_state displaced_step_state;
 502
 503   /* Per inferior data-pointers required by other GDB modules.  */
 504   REGISTRY_FIELDS;
 505 };
 506
 507 /* Keep a registry of per-inferior data-pointers required by other GDB
 508    modules.  */
 509
 510 DECLARE_REGISTRY (inferior);
 511
 512 /* Add an inferior to the inferior list, print a message that a new
 513    inferior is found, and return the pointer to the new inferior.
 514    Caller may use this pointer to initialize the private inferior
 515    data.  */
 516 extern struct inferior *add_inferior (int pid);
 517
 518 /* Same as add_inferior, but don't print new inferior notifications to
 519    the CLI.  */
 520 extern struct inferior *add_inferior_silent (int pid);
 521
 522 extern void delete_inferior (struct inferior *todel);
 523
 524 /* Delete an existing inferior list entry, due to inferior detaching.  */
 525 extern void detach_inferior (inferior *inf);
 526
 527 extern void exit_inferior (inferior *inf);
 528
 529 extern void exit_inferior_silent (inferior *inf);
 530
 531 extern void exit_inferior_num_silent (int num);
 532
 533 extern void inferior_appeared (struct inferior *inf, int pid);
 534
 535 /* Get rid of all inferiors.  */
 536 extern void discard_all_inferiors (void);
 537
 538 /* Search function to lookup an inferior by target 'pid'.  */
 539 extern struct inferior *find_inferior_pid (int pid);
 540
 541 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 542 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 543
 544 /* Search function to lookup an inferior by GDB 'num'.  */
 545 extern struct inferior *find_inferior_id (int num);
 546
 547 /* Find an inferior bound to PSPACE, giving preference to the current
 548    inferior.  */
 549 extern struct inferior *
 550   find_inferior_for_program_space (struct program_space *pspace);
 551
 552 /* Inferior iterator function.
 553
 554    Calls a callback function once for each inferior, so long as the
 555    callback function returns false.  If the callback function returns
 556    true, the iteration will end and the current inferior will be
 557    returned.  This can be useful for implementing a search for a
 558    inferior with arbitrary attributes, or for applying some operation
 559    to every inferior.
 560
 561    It is safe to delete the iterated inferior from the callback.  */
 562 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 563                                                          void *),
 564                                                 void *);
 565
 566 /* Returns true if the inferior list is not empty.  */
 567 extern int have_inferiors (void);
 568
 569 /* Returns the number of live inferiors (real live processes).  */
 570 extern int number_of_live_inferiors (void);
 571
 572 /* Returns true if there are any live inferiors in the inferior list
 573    (not cores, not executables, real live processes).  */
 574 extern int have_live_inferiors (void);
 575
 576 /* Save/restore the current inferior.  */
 577
 578 class scoped_restore_current_inferior
 579 {
 580 public:
 581   scoped_restore_current_inferior ()
 582     : m_saved_inf (current_inferior ())
 583   {}
 584
 585   ~scoped_restore_current_inferior ()
 586   { set_current_inferior (m_saved_inf); }
 587
 588   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 589
 590 private:
 591   inferior *m_saved_inf;
 592 };
 593
 594
 595 /* Traverse all inferiors.  */
 596
 597 extern struct inferior *inferior_list;
 598
 599 /* Pull in the internals of the inferiors ranges and iterators.  Must
 600    be done after struct inferior is defined.  */
 601 #include "inferior-iter.h"
 602
 603 /* Return a range that can be used to walk over all inferiors
 604    inferiors, with range-for, safely.  I.e., it is safe to delete the
 605    currently-iterated inferior.  When combined with range-for, this
 606    allow convenient patterns like this:
 607
 608      for (inferior *inf : all_inferiors_safe ())
 609        if (some_condition ())
 610          delete inf;
 611 */
 612
 613 inline all_inferiors_safe_range
 614 all_inferiors_safe ()
 615 {
 616   return {};
 617 }
 618
 619 /* Returns a range representing all inferiors, suitable to use with
 620    range-for, like this:
 621
 622    for (inferior *inf : all_inferiors ())
 623      [...]
 624 */
 625
 626 inline all_inferiors_range
 627 all_inferiors ()
 628 {
 629   return {};
 630 }
 631
 632 /* Return a range that can be used to walk over all inferiors with PID
 633    not zero, with range-for.  */
 634
 635 inline all_non_exited_inferiors_range
 636 all_non_exited_inferiors ()
 637 {
 638   return {};
 639 }
 640
 641 /* Prune away automatically added inferiors that aren't required
 642    anymore.  */
 643 extern void prune_inferiors (void);
 644
 645 extern int number_of_inferiors (void);
 646
 647 extern struct inferior *add_inferior_with_spaces (void);
 648
 649 /* Print the current selected inferior.  */
 650 extern void print_selected_inferior (struct ui_out *uiout);
 651
 652 #endif /* !defined (INFERIOR_H) */