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 /* Switch inferior (and program space) to INF, and switch to no thread
 312    selected.  */
 313 extern void switch_to_inferior_no_thread (inferior *inf);
 314
 315 /* GDB represents the state of each program execution with an object
 316    called an inferior.  An inferior typically corresponds to a process
 317    but is more general and applies also to targets that do not have a
 318    notion of processes.  Each run of an executable creates a new
 319    inferior, as does each attachment to an existing process.
 320    Inferiors have unique internal identifiers that are different from
 321    target process ids.  Each inferior may in turn have multiple
 322    threads running in it.
 323
 324    Inferiors are intrusively refcounted objects.  Unlike thread
 325    objects, being the user-selected inferior is considered a strong
 326    reference and is thus accounted for in the inferior object's
 327    refcount (see set_current_inferior).  When GDB needs to remember
 328    the selected inferior to later restore it, GDB temporarily bumps
 329    the inferior object's refcount, to prevent something deleting the
 330    inferior object before reverting back (e.g., due to a
 331    "remove-inferiors" command (see
 332    scoped_restore_current_inferior).  All other inferior
 333    references are considered weak references.  Inferiors are always
 334    listed exactly once in the inferior list, so placing an inferior in
 335    the inferior list is an implicit, not counted strong reference.  */
 336
 337 class inferior : public refcounted_object
 338 {
 339 public:
 340   explicit inferior (int pid);
 341   ~inferior ();
 342
 343   /* Returns true if we can delete this inferior.  */
 344   bool deletable () const { return refcount () == 0; }
 345
 346   bool has_execution ()
 347   { return target_has_execution_1 (this); }
 348
 349   /* Pointer to next inferior in singly-linked list of inferiors.  */
 350   struct inferior *next = NULL;
 351
 352   /* This inferior's thread list.  */
 353   thread_info *thread_list = nullptr;
 354
 355   /* Returns a range adapter covering the inferior's threads,
 356      including exited threads.  Used like this:
 357
 358        for (thread_info *thr : inf->threads ())
 359          { .... }
 360   */
 361   inf_threads_range threads ()
 362   { return inf_threads_range (this->thread_list); }
 363
 364   /* Returns a range adapter covering the inferior's non-exited
 365      threads.  Used like this:
 366
 367        for (thread_info *thr : inf->non_exited_threads ())
 368          { .... }
 369   */
 370   inf_non_exited_threads_range non_exited_threads ()
 371   { return inf_non_exited_threads_range (this->thread_list); }
 372
 373   /* Like inferior::threads(), but returns a range adapter that can be
 374      used with range-for, safely.  I.e., it is safe to delete the
 375      currently-iterated thread, like this:
 376
 377      for (thread_info *t : inf->threads_safe ())
 378        if (some_condition ())
 379          delete f;
 380   */
 381   inline safe_inf_threads_range threads_safe ()
 382   { return safe_inf_threads_range (this->thread_list); }
 383
 384   /* Convenient handle (GDB inferior id).  Unique across all
 385      inferiors.  */
 386   int num = 0;
 387
 388   /* Actual target inferior id, usually, a process id.  This matches
 389      the ptid_t.pid member of threads of this inferior.  */
 390   int pid = 0;
 391   /* True if the PID was actually faked by GDB.  */
 392   bool fake_pid_p = false;
 393
 394   /* The highest thread number this inferior ever had.  */
 395   int highest_thread_num = 0;
 396
 397   /* State of GDB control of inferior process execution.
 398      See `struct inferior_control_state'.  */
 399   inferior_control_state control;
 400
 401   /* True if this was an auto-created inferior, e.g. created from
 402      following a fork; false, if this inferior was manually added by
 403      the user, and we should not attempt to prune it
 404      automatically.  */
 405   bool removable = false;
 406
 407   /* The address space bound to this inferior.  */
 408   struct address_space *aspace = NULL;
 409
 410   /* The program space bound to this inferior.  */
 411   struct program_space *pspace = NULL;
 412
 413   /* The arguments string to use when running.  */
 414   char *args = NULL;
 415
 416   /* The size of elements in argv.  */
 417   int argc = 0;
 418
 419   /* The vector version of arguments.  If ARGC is nonzero,
 420      then we must compute ARGS from this (via the target).
 421      This is always coming from main's argv and therefore
 422      should never be freed.  */
 423   char **argv = NULL;
 424
 425   /* The current working directory that will be used when starting
 426      this inferior.  */
 427   gdb::unique_xmalloc_ptr<char> cwd;
 428
 429   /* The name of terminal device to use for I/O.  */
 430   char *terminal = NULL;
 431
 432   /* The terminal state as set by the last target_terminal::terminal_*
 433      call.  */
 434   target_terminal_state terminal_state = target_terminal_state::is_ours;
 435
 436   /* Environment to use for running inferior,
 437      in format described in environ.h.  */
 438   gdb_environ environment;
 439
 440   /* True if this child process was attached rather than forked.  */
 441   bool attach_flag = false;
 442
 443   /* If this inferior is a vfork child, then this is the pointer to
 444      its vfork parent, if GDB is still attached to it.  */
 445   inferior *vfork_parent = NULL;
 446
 447   /* If this process is a vfork parent, this is the pointer to the
 448      child.  Since a vfork parent is left frozen by the kernel until
 449      the child execs or exits, a process can only have one vfork child
 450      at a given time.  */
 451   inferior *vfork_child = NULL;
 452
 453   /* True if this inferior should be detached when it's vfork sibling
 454      exits or execs.  */
 455   bool pending_detach = false;
 456
 457   /* True if this inferior is a vfork parent waiting for a vfork child
 458      not under our control to be done with the shared memory region,
 459      either by exiting or execing.  */
 460   bool waiting_for_vfork_done = false;
 461
 462   /* True if we're in the process of detaching from this inferior.  */
 463   bool detaching = false;
 464
 465   /* What is left to do for an execution command after any thread of
 466      this inferior stops.  For continuations associated with a
 467      specific thread, see `struct thread_info'.  */
 468   continuation *continuations = NULL;
 469
 470   /* True if setup_inferior wasn't called for this inferior yet.
 471      Until that is done, we must not access inferior memory or
 472      registers, as we haven't determined the target
 473      architecture/description.  */
 474   bool needs_setup = false;
 475
 476   /* Private data used by the target vector implementation.  */
 477   std::unique_ptr<private_inferior> priv;
 478
 479   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 480      In this case, the EXIT_CODE field is also valid.  */
 481   bool has_exit_code = false;
 482   LONGEST exit_code = 0;
 483
 484   /* Default flags to pass to the symbol reading functions.  These are
 485      used whenever a new objfile is created.  */
 486   symfile_add_flags symfile_flags = 0;
 487
 488   /* Info about an inferior's target description (if it's fetched; the
 489      user supplied description's filename, if any; etc.).  */
 490   target_desc_info *tdesc_info = NULL;
 491
 492   /* The architecture associated with the inferior through the
 493      connection to the target.
 494
 495      The architecture vector provides some information that is really
 496      a property of the inferior, accessed through a particular target:
 497      ptrace operations; the layout of certain RSP packets; the
 498      solib_ops vector; etc.  To differentiate architecture accesses to
 499      per-inferior/target properties from
 500      per-thread/per-frame/per-objfile properties, accesses to
 501      per-inferior/target properties should be made through
 502      this gdbarch.  */
 503   struct gdbarch *gdbarch = NULL;
 504
 505   /* Data related to displaced stepping.  */
 506   displaced_step_inferior_state displaced_step_state;
 507
 508   /* Per inferior data-pointers required by other GDB modules.  */
 509   REGISTRY_FIELDS;
 510 };
 511
 512 /* Keep a registry of per-inferior data-pointers required by other GDB
 513    modules.  */
 514
 515 DECLARE_REGISTRY (inferior);
 516
 517 /* Add an inferior to the inferior list, print a message that a new
 518    inferior is found, and return the pointer to the new inferior.
 519    Caller may use this pointer to initialize the private inferior
 520    data.  */
 521 extern struct inferior *add_inferior (int pid);
 522
 523 /* Same as add_inferior, but don't print new inferior notifications to
 524    the CLI.  */
 525 extern struct inferior *add_inferior_silent (int pid);
 526
 527 extern void delete_inferior (struct inferior *todel);
 528
 529 /* Delete an existing inferior list entry, due to inferior detaching.  */
 530 extern void detach_inferior (inferior *inf);
 531
 532 extern void exit_inferior (inferior *inf);
 533
 534 extern void exit_inferior_silent (inferior *inf);
 535
 536 extern void exit_inferior_num_silent (int num);
 537
 538 extern void inferior_appeared (struct inferior *inf, int pid);
 539
 540 /* Get rid of all inferiors.  */
 541 extern void discard_all_inferiors (void);
 542
 543 /* Search function to lookup an inferior by target 'pid'.  */
 544 extern struct inferior *find_inferior_pid (int pid);
 545
 546 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 547 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 548
 549 /* Search function to lookup an inferior by GDB 'num'.  */
 550 extern struct inferior *find_inferior_id (int num);
 551
 552 /* Find an inferior bound to PSPACE, giving preference to the current
 553    inferior.  */
 554 extern struct inferior *
 555   find_inferior_for_program_space (struct program_space *pspace);
 556
 557 /* Inferior iterator function.
 558
 559    Calls a callback function once for each inferior, so long as the
 560    callback function returns false.  If the callback function returns
 561    true, the iteration will end and the current inferior will be
 562    returned.  This can be useful for implementing a search for a
 563    inferior with arbitrary attributes, or for applying some operation
 564    to every inferior.
 565
 566    It is safe to delete the iterated inferior from the callback.  */
 567 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 568                                                          void *),
 569                                                 void *);
 570
 571 /* Returns true if the inferior list is not empty.  */
 572 extern int have_inferiors (void);
 573
 574 /* Returns the number of live inferiors (real live processes).  */
 575 extern int number_of_live_inferiors (void);
 576
 577 /* Returns true if there are any live inferiors in the inferior list
 578    (not cores, not executables, real live processes).  */
 579 extern int have_live_inferiors (void);
 580
 581 /* Save/restore the current inferior.  */
 582
 583 class scoped_restore_current_inferior
 584 {
 585 public:
 586   scoped_restore_current_inferior ()
 587     : m_saved_inf (current_inferior ())
 588   {}
 589
 590   ~scoped_restore_current_inferior ()
 591   { set_current_inferior (m_saved_inf); }
 592
 593   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 594
 595 private:
 596   inferior *m_saved_inf;
 597 };
 598
 599
 600 /* Traverse all inferiors.  */
 601
 602 extern struct inferior *inferior_list;
 603
 604 /* Pull in the internals of the inferiors ranges and iterators.  Must
 605    be done after struct inferior is defined.  */
 606 #include "inferior-iter.h"
 607
 608 /* Return a range that can be used to walk over all inferiors
 609    inferiors, with range-for, safely.  I.e., it is safe to delete the
 610    currently-iterated inferior.  When combined with range-for, this
 611    allow convenient patterns like this:
 612
 613      for (inferior *inf : all_inferiors_safe ())
 614        if (some_condition ())
 615          delete inf;
 616 */
 617
 618 inline all_inferiors_safe_range
 619 all_inferiors_safe ()
 620 {
 621   return {};
 622 }
 623
 624 /* Returns a range representing all inferiors, suitable to use with
 625    range-for, like this:
 626
 627    for (inferior *inf : all_inferiors ())
 628      [...]
 629 */
 630
 631 inline all_inferiors_range
 632 all_inferiors ()
 633 {
 634   return {};
 635 }
 636
 637 /* Return a range that can be used to walk over all inferiors with PID
 638    not zero, with range-for.  */
 639
 640 inline all_non_exited_inferiors_range
 641 all_non_exited_inferiors ()
 642 {
 643   return {};
 644 }
 645
 646 /* Prune away automatically added inferiors that aren't required
 647    anymore.  */
 648 extern void prune_inferiors (void);
 649
 650 extern int number_of_inferiors (void);
 651
 652 extern struct inferior *add_inferior_with_spaces (void);
 653
 654 /* Print the current selected inferior.  */
 655 extern void print_selected_inferior (struct ui_out *uiout);
 656
 657 #endif /* !defined (INFERIOR_H) */