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) 1986-2020 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 child_terminal_ours (struct target_ops *self);
 163
 164 extern void child_terminal_ours_for_output (struct target_ops *self);
 165
 166 extern void child_terminal_inferior (struct target_ops *self);
 167
 168 extern void child_terminal_save_inferior (struct target_ops *self);
 169
 170 extern void child_terminal_init (struct target_ops *self);
 171
 172 extern void child_terminal_init_with_pgrp (int pgrp);
 173
 174 extern void child_pass_ctrlc (struct target_ops *self);
 175
 176 extern void child_interrupt (struct target_ops *self);
 177
 178 /* From fork-child.c */
 179
 180 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 181    This function already calls set_executing.  Return the ptid_t from
 182    STARTUP_INFERIOR.  */
 183 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 184
 185 extern char *construct_inferior_arguments (int, char **);
 186
 187 /* From infcmd.c */
 188
 189 /* Initial inferior setup.  Determines the exec file is not yet known,
 190    takes any necessary post-attaching actions, fetches the target
 191    description and syncs the shared library list.  */
 192
 193 extern void setup_inferior (int from_tty);
 194
 195 extern void post_create_inferior (struct target_ops *, int);
 196
 197 extern void attach_command (const char *, int);
 198
 199 extern const char *get_inferior_args (void);
 200
 201 extern void set_inferior_args (const char *);
 202
 203 extern void set_inferior_args_vector (int, char **);
 204
 205 extern void registers_info (const char *, int);
 206
 207 extern void continue_1 (int all_threads);
 208
 209 extern void interrupt_target_1 (int all_threads);
 210
 211 using delete_longjmp_breakpoint_cleanup
 212   = FORWARD_SCOPE_EXIT (delete_longjmp_breakpoint);
 213
 214 extern void detach_command (const char *, int);
 215
 216 extern void notice_new_inferior (struct thread_info *, int, int);
 217
 218 extern struct value *get_return_value (struct value *function,
 219                                        struct type *value_type);
 220
 221 /* Prepare for execution command.  TARGET is the target that will run
 222    the command.  BACKGROUND determines whether this is a foreground
 223    (synchronous) or background (asynchronous) command.  */
 224
 225 extern void prepare_execution_command (struct target_ops *target,
 226                                        int background);
 227
 228 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 229
 230 extern enum stop_stack_kind stop_stack_dummy;
 231
 232 /* Nonzero if program stopped due to a random (unexpected) signal in
 233    inferior process.  */
 234
 235 extern int stopped_by_random_signal;
 236
 237 /* Print notices on inferior events (attach, detach, etc.), set with
 238    `set print inferior-events'.  */
 239 extern bool print_inferior_events;
 240
 241 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 242    will handle it themselves.  STOP_QUIETLY is used when running in
 243    the shell before the child program has been exec'd and when running
 244    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 245    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 246    except that there is no need to hide a signal.  */
 247
 248 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 249    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 250    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 251    a ptraced process has changed.  Earlier versions of the kernel
 252    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 253    other signal, i.e. it is not muffled.
 254
 255    If the gdb user does a 'continue' after the 'attach', gdb passes
 256    the global variable stop_signal (which stores the signal from the
 257    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 258    problematic, because the kernel doesn't ignore such SIGSTOP
 259    now.  I.e. it is reported back to gdb, which in turn presents it
 260    back to the user.
 261
 262    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 263    gdb to clear the value of stop_signal after the attach, so that it
 264    is not passed back down to the kernel.  */
 265
 266 enum stop_kind
 267   {
 268     NO_STOP_QUIETLY = 0,
 269     STOP_QUIETLY,
 270     STOP_QUIETLY_REMOTE,
 271     STOP_QUIETLY_NO_SIGSTOP
 272   };
 273
 274 \f
 275 /* Possible values for gdbarch_call_dummy_location.  */
 276 #define ON_STACK 1
 277 #define AT_ENTRY_POINT 4
 278
 279 /* Base class for target-specific inferior data.  */
 280
 281 struct private_inferior
 282 {
 283   virtual ~private_inferior () = 0;
 284 };
 285
 286 /* Inferior process specific part of `struct infcall_control_state'.
 287
 288    Inferior thread counterpart is `struct thread_control_state'.  */
 289
 290 struct inferior_control_state
 291 {
 292   inferior_control_state ()
 293     : stop_soon (NO_STOP_QUIETLY)
 294   {
 295   }
 296
 297   explicit inferior_control_state (enum stop_kind when)
 298     : stop_soon (when)
 299   {
 300   }
 301
 302   /* See the definition of stop_kind above.  */
 303   enum stop_kind stop_soon;
 304 };
 305
 306 /* Return a pointer to the current inferior.  */
 307 extern inferior *current_inferior ();
 308
 309 extern void set_current_inferior (inferior *);
 310
 311 /* GDB represents the state of each program execution with an object
 312    called an inferior.  An inferior typically corresponds to a process
 313    but is more general and applies also to targets that do not have a
 314    notion of processes.  Each run of an executable creates a new
 315    inferior, as does each attachment to an existing process.
 316    Inferiors have unique internal identifiers that are different from
 317    target process ids.  Each inferior may in turn have multiple
 318    threads running in it.
 319
 320    Inferiors are intrusively refcounted objects.  Unlike thread
 321    objects, being the user-selected inferior is considered a strong
 322    reference and is thus accounted for in the inferior object's
 323    refcount (see set_current_inferior).  When GDB needs to remember
 324    the selected inferior to later restore it, GDB temporarily bumps
 325    the inferior object's refcount, to prevent something deleting the
 326    inferior object before reverting back (e.g., due to a
 327    "remove-inferiors" command (see
 328    scoped_restore_current_inferior).  All other inferior
 329    references are considered weak references.  Inferiors are always
 330    listed exactly once in the inferior list, so placing an inferior in
 331    the inferior list is an implicit, not counted strong reference.  */
 332
 333 class inferior : public refcounted_object
 334 {
 335 public:
 336   explicit inferior (int pid);
 337   ~inferior ();
 338
 339   /* Returns true if we can delete this inferior.  */
 340   bool deletable () const { return refcount () == 0; }
 341
 342   /* Pointer to next inferior in singly-linked list of inferiors.  */
 343   struct inferior *next = NULL;
 344
 345   /* This inferior's thread list.  */
 346   thread_info *thread_list = nullptr;
 347
 348   /* Returns a range adapter covering the inferior's threads,
 349      including exited threads.  Used like this:
 350
 351        for (thread_info *thr : inf->threads ())
 352          { .... }
 353   */
 354   inf_threads_range threads ()
 355   { return inf_threads_range (this->thread_list); }
 356
 357   /* Returns a range adapter covering the inferior's non-exited
 358      threads.  Used like this:
 359
 360        for (thread_info *thr : inf->non_exited_threads ())
 361          { .... }
 362   */
 363   inf_non_exited_threads_range non_exited_threads ()
 364   { return inf_non_exited_threads_range (this->thread_list); }
 365
 366   /* Like inferior::threads(), but returns a range adapter that can be
 367      used with range-for, safely.  I.e., it is safe to delete the
 368      currently-iterated thread, like this:
 369
 370      for (thread_info *t : inf->threads_safe ())
 371        if (some_condition ())
 372          delete f;
 373   */
 374   inline safe_inf_threads_range threads_safe ()
 375   { return safe_inf_threads_range (this->thread_list); }
 376
 377   /* Convenient handle (GDB inferior id).  Unique across all
 378      inferiors.  */
 379   int num = 0;
 380
 381   /* Actual target inferior id, usually, a process id.  This matches
 382      the ptid_t.pid member of threads of this inferior.  */
 383   int pid = 0;
 384   /* True if the PID was actually faked by GDB.  */
 385   bool fake_pid_p = false;
 386
 387   /* The highest thread number this inferior ever had.  */
 388   int highest_thread_num = 0;
 389
 390   /* State of GDB control of inferior process execution.
 391      See `struct inferior_control_state'.  */
 392   inferior_control_state control;
 393
 394   /* True if this was an auto-created inferior, e.g. created from
 395      following a fork; false, if this inferior was manually added by
 396      the user, and we should not attempt to prune it
 397      automatically.  */
 398   bool removable = false;
 399
 400   /* The address space bound to this inferior.  */
 401   struct address_space *aspace = NULL;
 402
 403   /* The program space bound to this inferior.  */
 404   struct program_space *pspace = NULL;
 405
 406   /* The arguments string to use when running.  */
 407   char *args = NULL;
 408
 409   /* The size of elements in argv.  */
 410   int argc = 0;
 411
 412   /* The vector version of arguments.  If ARGC is nonzero,
 413      then we must compute ARGS from this (via the target).
 414      This is always coming from main's argv and therefore
 415      should never be freed.  */
 416   char **argv = NULL;
 417
 418   /* The current working directory that will be used when starting
 419      this inferior.  */
 420   gdb::unique_xmalloc_ptr<char> cwd;
 421
 422   /* The name of terminal device to use for I/O.  */
 423   char *terminal = NULL;
 424
 425   /* The terminal state as set by the last target_terminal::terminal_*
 426      call.  */
 427   target_terminal_state terminal_state = target_terminal_state::is_ours;
 428
 429   /* Environment to use for running inferior,
 430      in format described in environ.h.  */
 431   gdb_environ environment;
 432
 433   /* True if this child process was attached rather than forked.  */
 434   bool attach_flag = false;
 435
 436   /* If this inferior is a vfork child, then this is the pointer to
 437      its vfork parent, if GDB is still attached to it.  */
 438   inferior *vfork_parent = NULL;
 439
 440   /* If this process is a vfork parent, this is the pointer to the
 441      child.  Since a vfork parent is left frozen by the kernel until
 442      the child execs or exits, a process can only have one vfork child
 443      at a given time.  */
 444   inferior *vfork_child = NULL;
 445
 446   /* True if this inferior should be detached when it's vfork sibling
 447      exits or execs.  */
 448   bool pending_detach = false;
 449
 450   /* True if this inferior is a vfork parent waiting for a vfork child
 451      not under our control to be done with the shared memory region,
 452      either by exiting or execing.  */
 453   bool waiting_for_vfork_done = false;
 454
 455   /* True if we're in the process of detaching from this inferior.  */
 456   bool detaching = false;
 457
 458   /* What is left to do for an execution command after any thread of
 459      this inferior stops.  For continuations associated with a
 460      specific thread, see `struct thread_info'.  */
 461   continuation *continuations = NULL;
 462
 463   /* True if setup_inferior wasn't called for this inferior yet.
 464      Until that is done, we must not access inferior memory or
 465      registers, as we haven't determined the target
 466      architecture/description.  */
 467   bool needs_setup = false;
 468
 469   /* Private data used by the target vector implementation.  */
 470   std::unique_ptr<private_inferior> priv;
 471
 472   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 473      In this case, the EXIT_CODE field is also valid.  */
 474   bool has_exit_code = false;
 475   LONGEST exit_code = 0;
 476
 477   /* Default flags to pass to the symbol reading functions.  These are
 478      used whenever a new objfile is created.  */
 479   symfile_add_flags symfile_flags = 0;
 480
 481   /* Info about an inferior's target description (if it's fetched; the
 482      user supplied description's filename, if any; etc.).  */
 483   target_desc_info *tdesc_info = NULL;
 484
 485   /* The architecture associated with the inferior through the
 486      connection to the target.
 487
 488      The architecture vector provides some information that is really
 489      a property of the inferior, accessed through a particular target:
 490      ptrace operations; the layout of certain RSP packets; the
 491      solib_ops vector; etc.  To differentiate architecture accesses to
 492      per-inferior/target properties from
 493      per-thread/per-frame/per-objfile properties, accesses to
 494      per-inferior/target properties should be made through
 495      this gdbarch.  */
 496   struct gdbarch *gdbarch = NULL;
 497
 498   /* Data related to displaced stepping.  */
 499   displaced_step_inferior_state displaced_step_state;
 500
 501   /* Per inferior data-pointers required by other GDB modules.  */
 502   REGISTRY_FIELDS;
 503 };
 504
 505 /* Keep a registry of per-inferior data-pointers required by other GDB
 506    modules.  */
 507
 508 DECLARE_REGISTRY (inferior);
 509
 510 /* Add an inferior to the inferior list, print a message that a new
 511    inferior is found, and return the pointer to the new inferior.
 512    Caller may use this pointer to initialize the private inferior
 513    data.  */
 514 extern struct inferior *add_inferior (int pid);
 515
 516 /* Same as add_inferior, but don't print new inferior notifications to
 517    the CLI.  */
 518 extern struct inferior *add_inferior_silent (int pid);
 519
 520 extern void delete_inferior (struct inferior *todel);
 521
 522 /* Delete an existing inferior list entry, due to inferior detaching.  */
 523 extern void detach_inferior (inferior *inf);
 524
 525 extern void exit_inferior (inferior *inf);
 526
 527 extern void exit_inferior_silent (inferior *inf);
 528
 529 extern void exit_inferior_num_silent (int num);
 530
 531 extern void inferior_appeared (struct inferior *inf, int pid);
 532
 533 /* Get rid of all inferiors.  */
 534 extern void discard_all_inferiors (void);
 535
 536 /* Search function to lookup an inferior by target 'pid'.  */
 537 extern struct inferior *find_inferior_pid (int pid);
 538
 539 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 540 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 541
 542 /* Search function to lookup an inferior by GDB 'num'.  */
 543 extern struct inferior *find_inferior_id (int num);
 544
 545 /* Find an inferior bound to PSPACE, giving preference to the current
 546    inferior.  */
 547 extern struct inferior *
 548   find_inferior_for_program_space (struct program_space *pspace);
 549
 550 /* Inferior iterator function.
 551
 552    Calls a callback function once for each inferior, so long as the
 553    callback function returns false.  If the callback function returns
 554    true, the iteration will end and the current inferior will be
 555    returned.  This can be useful for implementing a search for a
 556    inferior with arbitrary attributes, or for applying some operation
 557    to every inferior.
 558
 559    It is safe to delete the iterated inferior from the callback.  */
 560 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 561                                                          void *),
 562                                                 void *);
 563
 564 /* Returns true if the inferior list is not empty.  */
 565 extern int have_inferiors (void);
 566
 567 /* Returns the number of live inferiors (real live processes).  */
 568 extern int number_of_live_inferiors (void);
 569
 570 /* Returns true if there are any live inferiors in the inferior list
 571    (not cores, not executables, real live processes).  */
 572 extern int have_live_inferiors (void);
 573
 574 /* Save/restore the current inferior.  */
 575
 576 class scoped_restore_current_inferior
 577 {
 578 public:
 579   scoped_restore_current_inferior ()
 580     : m_saved_inf (current_inferior ())
 581   {}
 582
 583   ~scoped_restore_current_inferior ()
 584   { set_current_inferior (m_saved_inf); }
 585
 586   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 587
 588 private:
 589   inferior *m_saved_inf;
 590 };
 591
 592
 593 /* Traverse all inferiors.  */
 594
 595 extern struct inferior *inferior_list;
 596
 597 /* Pull in the internals of the inferiors ranges and iterators.  Must
 598    be done after struct inferior is defined.  */
 599 #include "inferior-iter.h"
 600
 601 /* Return a range that can be used to walk over all inferiors
 602    inferiors, with range-for, safely.  I.e., it is safe to delete the
 603    currently-iterated inferior.  When combined with range-for, this
 604    allow convenient patterns like this:
 605
 606      for (inferior *inf : all_inferiors_safe ())
 607        if (some_condition ())
 608          delete inf;
 609 */
 610
 611 inline all_inferiors_safe_range
 612 all_inferiors_safe ()
 613 {
 614   return {};
 615 }
 616
 617 /* Returns a range representing all inferiors, suitable to use with
 618    range-for, like this:
 619
 620    for (inferior *inf : all_inferiors ())
 621      [...]
 622 */
 623
 624 inline all_inferiors_range
 625 all_inferiors ()
 626 {
 627   return {};
 628 }
 629
 630 /* Return a range that can be used to walk over all inferiors with PID
 631    not zero, with range-for.  */
 632
 633 inline all_non_exited_inferiors_range
 634 all_non_exited_inferiors ()
 635 {
 636   return {};
 637 }
 638
 639 /* Prune away automatically added inferiors that aren't required
 640    anymore.  */
 641 extern void prune_inferiors (void);
 642
 643 extern int number_of_inferiors (void);
 644
 645 extern struct inferior *add_inferior_with_spaces (void);
 646
 647 /* Print the current selected inferior.  */
 648 extern void print_selected_inferior (struct ui_out *uiout);
 649
 650 #endif /* !defined (INFERIOR_H) */