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 "common/environ.h"
  48
  49 #include "progspace.h"
  50 #include "registry.h"
  51
  52 #include "symfile-add-flags.h"
  53 #include "common/refcounted-object.h"
  54 #include "common/forward-scope-exit.h"
  55
  56 #include "common/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     restore_infcall_suspend_state (state);
  72   }
  73 };
  74
  75 /* A unique_ptr specialization for infcall_suspend_state.  */
  76 typedef std::unique_ptr<infcall_suspend_state, infcall_suspend_state_deleter>
  77     infcall_suspend_state_up;
  78
  79 extern infcall_suspend_state_up save_infcall_suspend_state ();
  80
  81 /* A deleter for infcall_control_state that calls
  82    restore_infcall_control_state.  */
  83 struct infcall_control_state_deleter
  84 {
  85   void operator() (struct infcall_control_state *state) const
  86   {
  87     restore_infcall_control_state (state);
  88   }
  89 };
  90
  91 /* A unique_ptr specialization for infcall_control_state.  */
  92 typedef std::unique_ptr<infcall_control_state, infcall_control_state_deleter>
  93     infcall_control_state_up;
  94
  95 extern infcall_control_state_up save_infcall_control_state ();
  96
  97 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
  98 extern void discard_infcall_control_state (struct infcall_control_state *);
  99
 100 extern readonly_detached_regcache *
 101   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
 102
 103 extern void set_sigint_trap (void);
 104
 105 extern void clear_sigint_trap (void);
 106
 107 /* Set/get file name for default use for standard in/out in the inferior.  */
 108
 109 extern void set_inferior_io_terminal (const char *terminal_name);
 110 extern const char *get_inferior_io_terminal (void);
 111
 112 /* Collected pid, tid, etc. of the debugged inferior.  When there's
 113    no inferior, inferior_ptid.pid () will be 0.  */
 114
 115 extern ptid_t inferior_ptid;
 116
 117 extern void generic_mourn_inferior (void);
 118
 119 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
 120                                               struct type *type,
 121                                               const gdb_byte *buf);
 122 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
 123                                          struct type *type, gdb_byte *buf,
 124                                          CORE_ADDR addr);
 125 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 126                                             struct type *type,
 127                                             const gdb_byte *buf);
 128 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 129                                        struct type *type, gdb_byte *buf,
 130                                        CORE_ADDR addr);
 131
 132 extern void reopen_exec_file (void);
 133
 134 /* From misc files */
 135
 136 extern void default_print_registers_info (struct gdbarch *gdbarch,
 137                                           struct ui_file *file,
 138                                           struct frame_info *frame,
 139                                           int regnum, int all);
 140
 141 /* Default implementation of gdbarch_print_float_info.  Print
 142    the values of all floating point registers.  */
 143
 144 extern void default_print_float_info (struct gdbarch *gdbarch,
 145                                       struct ui_file *file,
 146                                       struct frame_info *frame,
 147                                       const char *args);
 148
 149 extern void child_terminal_info (struct target_ops *self, const char *, int);
 150
 151 extern void info_terminal_command (char *, int);
 152
 153 extern void child_terminal_ours (struct target_ops *self);
 154
 155 extern void child_terminal_ours_for_output (struct target_ops *self);
 156
 157 extern void child_terminal_inferior (struct target_ops *self);
 158
 159 extern void child_terminal_save_inferior (struct target_ops *self);
 160
 161 extern void child_terminal_init (struct target_ops *self);
 162
 163 extern void child_terminal_init_with_pgrp (int pgrp);
 164
 165 extern void child_pass_ctrlc (struct target_ops *self);
 166
 167 extern void child_interrupt (struct target_ops *self);
 168
 169 /* From fork-child.c */
 170
 171 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 172    This function already calls set_executing.  Return the ptid_t from
 173    STARTUP_INFERIOR.  */
 174 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 175
 176 extern char *construct_inferior_arguments (int, char **);
 177
 178 /* From infcmd.c */
 179
 180 /* Initial inferior setup.  Determines the exec file is not yet known,
 181    takes any necessary post-attaching actions, fetches the target
 182    description and syncs the shared library list.  */
 183
 184 extern void setup_inferior (int from_tty);
 185
 186 extern void post_create_inferior (struct target_ops *, int);
 187
 188 extern void attach_command (const char *, int);
 189
 190 extern const char *get_inferior_args (void);
 191
 192 extern void set_inferior_args (const char *);
 193
 194 extern void set_inferior_args_vector (int, char **);
 195
 196 extern void registers_info (const char *, int);
 197
 198 extern void continue_1 (int all_threads);
 199
 200 extern void interrupt_target_1 (int all_threads);
 201
 202 using delete_longjmp_breakpoint_cleanup
 203   = FORWARD_SCOPE_EXIT (delete_longjmp_breakpoint);
 204
 205 extern void detach_command (const char *, int);
 206
 207 extern void notice_new_inferior (struct thread_info *, int, int);
 208
 209 extern struct value *get_return_value (struct value *function,
 210                                        struct type *value_type);
 211
 212 /* Prepare for execution command.  TARGET is the target that will run
 213    the command.  BACKGROUND determines whether this is a foreground
 214    (synchronous) or background (asynchronous) command.  */
 215
 216 extern void prepare_execution_command (struct target_ops *target,
 217                                        int background);
 218
 219 /* Whether to start up the debuggee under a shell.
 220
 221    If startup-with-shell is set, GDB's "run" will attempt to start up
 222    the debuggee under a shell.
 223
 224    This is in order for argument-expansion to occur.  E.g.,
 225
 226    (gdb) run *
 227
 228    The "*" gets expanded by the shell into a list of files.
 229
 230    While this is a nice feature, it may be handy to bypass the shell
 231    in some cases.  To disable this feature, do "set startup-with-shell
 232    false".
 233
 234    The catch-exec traps expected during start-up will be one more if
 235    the target is started up with a shell.  */
 236 extern int startup_with_shell;
 237
 238 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 239
 240 extern enum stop_stack_kind stop_stack_dummy;
 241
 242 /* Nonzero if program stopped due to a random (unexpected) signal in
 243    inferior process.  */
 244
 245 extern int stopped_by_random_signal;
 246
 247 /* Print notices on inferior events (attach, detach, etc.), set with
 248    `set print inferior-events'.  */
 249 extern int print_inferior_events;
 250
 251 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 252    will handle it themselves.  STOP_QUIETLY is used when running in
 253    the shell before the child program has been exec'd and when running
 254    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 255    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 256    except that there is no need to hide a signal.  */
 257
 258 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 259    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 260    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 261    a ptraced process has changed.  Earlier versions of the kernel
 262    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 263    other signal, i.e. it is not muffled.
 264
 265    If the gdb user does a 'continue' after the 'attach', gdb passes
 266    the global variable stop_signal (which stores the signal from the
 267    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 268    problematic, because the kernel doesn't ignore such SIGSTOP
 269    now.  I.e. it is reported back to gdb, which in turn presents it
 270    back to the user.
 271
 272    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 273    gdb to clear the value of stop_signal after the attach, so that it
 274    is not passed back down to the kernel.  */
 275
 276 enum stop_kind
 277   {
 278     NO_STOP_QUIETLY = 0,
 279     STOP_QUIETLY,
 280     STOP_QUIETLY_REMOTE,
 281     STOP_QUIETLY_NO_SIGSTOP
 282   };
 283
 284 \f
 285 /* Possible values for gdbarch_call_dummy_location.  */
 286 #define ON_STACK 1
 287 #define AT_ENTRY_POINT 4
 288
 289 /* Base class for target-specific inferior data.  */
 290
 291 struct private_inferior
 292 {
 293   virtual ~private_inferior () = 0;
 294 };
 295
 296 /* Inferior process specific part of `struct infcall_control_state'.
 297
 298    Inferior thread counterpart is `struct thread_control_state'.  */
 299
 300 struct inferior_control_state
 301 {
 302   inferior_control_state ()
 303     : stop_soon (NO_STOP_QUIETLY)
 304   {
 305   }
 306
 307   explicit inferior_control_state (enum stop_kind when)
 308     : stop_soon (when)
 309   {
 310   }
 311
 312   /* See the definition of stop_kind above.  */
 313   enum stop_kind stop_soon;
 314 };
 315
 316 /* Return a pointer to the current inferior.  */
 317 extern inferior *current_inferior ();
 318
 319 extern void set_current_inferior (inferior *);
 320
 321 /* GDB represents the state of each program execution with an object
 322    called an inferior.  An inferior typically corresponds to a process
 323    but is more general and applies also to targets that do not have a
 324    notion of processes.  Each run of an executable creates a new
 325    inferior, as does each attachment to an existing process.
 326    Inferiors have unique internal identifiers that are different from
 327    target process ids.  Each inferior may in turn have multiple
 328    threads running in it.
 329
 330    Inferiors are intrusively refcounted objects.  Unlike thread
 331    objects, being the user-selected inferior is considered a strong
 332    reference and is thus accounted for in the inferior object's
 333    refcount (see set_current_inferior).  When GDB needs to remember
 334    the selected inferior to later restore it, GDB temporarily bumps
 335    the inferior object's refcount, to prevent something deleting the
 336    inferior object before reverting back (e.g., due to a
 337    "remove-inferiors" command (see
 338    scoped_restore_current_inferior).  All other inferior
 339    references are considered weak references.  Inferiors are always
 340    listed exactly once in the inferior list, so placing an inferior in
 341    the inferior list is an implicit, not counted strong reference.  */
 342
 343 class inferior : public refcounted_object
 344 {
 345 public:
 346   explicit inferior (int pid);
 347   ~inferior ();
 348
 349   /* Returns true if we can delete this inferior.  */
 350   bool deletable () const { return refcount () == 0; }
 351
 352   /* Pointer to next inferior in singly-linked list of inferiors.  */
 353   struct inferior *next = NULL;
 354
 355   /* This inferior's thread list.  */
 356   thread_info *thread_list = nullptr;
 357
 358   /* Returns a range adapter covering the inferior's threads,
 359      including exited threads.  Used like this:
 360
 361        for (thread_info *thr : inf->threads ())
 362          { .... }
 363   */
 364   inf_threads_range threads ()
 365   { return inf_threads_range (this->thread_list); }
 366
 367   /* Returns a range adapter covering the inferior's non-exited
 368      threads.  Used like this:
 369
 370        for (thread_info *thr : inf->non_exited_threads ())
 371          { .... }
 372   */
 373   inf_non_exited_threads_range non_exited_threads ()
 374   { return inf_non_exited_threads_range (this->thread_list); }
 375
 376   /* Like inferior::threads(), but returns a range adapter that can be
 377      used with range-for, safely.  I.e., it is safe to delete the
 378      currently-iterated thread, like this:
 379
 380      for (thread_info *t : inf->threads_safe ())
 381        if (some_condition ())
 382          delete f;
 383   */
 384   inline safe_inf_threads_range threads_safe ()
 385   { return safe_inf_threads_range (this->thread_list); }
 386
 387   /* Convenient handle (GDB inferior id).  Unique across all
 388      inferiors.  */
 389   int num = 0;
 390
 391   /* Actual target inferior id, usually, a process id.  This matches
 392      the ptid_t.pid member of threads of this inferior.  */
 393   int pid = 0;
 394   /* True if the PID was actually faked by GDB.  */
 395   bool fake_pid_p = false;
 396
 397   /* The highest thread number this inferior ever had.  */
 398   int highest_thread_num = 0;
 399
 400   /* State of GDB control of inferior process execution.
 401      See `struct inferior_control_state'.  */
 402   inferior_control_state control;
 403
 404   /* True if this was an auto-created inferior, e.g. created from
 405      following a fork; false, if this inferior was manually added by
 406      the user, and we should not attempt to prune it
 407      automatically.  */
 408   bool removable = false;
 409
 410   /* The address space bound to this inferior.  */
 411   struct address_space *aspace = NULL;
 412
 413   /* The program space bound to this inferior.  */
 414   struct program_space *pspace = NULL;
 415
 416   /* The arguments string to use when running.  */
 417   char *args = NULL;
 418
 419   /* The size of elements in argv.  */
 420   int argc = 0;
 421
 422   /* The vector version of arguments.  If ARGC is nonzero,
 423      then we must compute ARGS from this (via the target).
 424      This is always coming from main's argv and therefore
 425      should never be freed.  */
 426   char **argv = NULL;
 427
 428   /* The current working directory that will be used when starting
 429      this inferior.  */
 430   gdb::unique_xmalloc_ptr<char> cwd;
 431
 432   /* The name of terminal device to use for I/O.  */
 433   char *terminal = NULL;
 434
 435   /* The terminal state as set by the last target_terminal::terminal_*
 436      call.  */
 437   target_terminal_state terminal_state = target_terminal_state::is_ours;
 438
 439   /* Environment to use for running inferior,
 440      in format described in environ.h.  */
 441   gdb_environ environment;
 442
 443   /* True if this child process was attached rather than forked.  */
 444   bool attach_flag = false;
 445
 446   /* If this inferior is a vfork child, then this is the pointer to
 447      its vfork parent, if GDB is still attached to it.  */
 448   inferior *vfork_parent = NULL;
 449
 450   /* If this process is a vfork parent, this is the pointer to the
 451      child.  Since a vfork parent is left frozen by the kernel until
 452      the child execs or exits, a process can only have one vfork child
 453      at a given time.  */
 454   inferior *vfork_child = NULL;
 455
 456   /* True if this inferior should be detached when it's vfork sibling
 457      exits or execs.  */
 458   bool pending_detach = false;
 459
 460   /* True if this inferior is a vfork parent waiting for a vfork child
 461      not under our control to be done with the shared memory region,
 462      either by exiting or execing.  */
 463   bool waiting_for_vfork_done = false;
 464
 465   /* True if we're in the process of detaching from this inferior.  */
 466   bool detaching = false;
 467
 468   /* What is left to do for an execution command after any thread of
 469      this inferior stops.  For continuations associated with a
 470      specific thread, see `struct thread_info'.  */
 471   continuation *continuations = NULL;
 472
 473   /* True if setup_inferior wasn't called for this inferior yet.
 474      Until that is done, we must not access inferior memory or
 475      registers, as we haven't determined the target
 476      architecture/description.  */
 477   bool needs_setup = false;
 478
 479   /* Private data used by the target vector implementation.  */
 480   std::unique_ptr<private_inferior> priv;
 481
 482   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 483      In this case, the EXIT_CODE field is also valid.  */
 484   bool has_exit_code = false;
 485   LONGEST exit_code = 0;
 486
 487   /* Default flags to pass to the symbol reading functions.  These are
 488      used whenever a new objfile is created.  */
 489   symfile_add_flags symfile_flags = 0;
 490
 491   /* Info about an inferior's target description (if it's fetched; the
 492      user supplied description's filename, if any; etc.).  */
 493   target_desc_info *tdesc_info = NULL;
 494
 495   /* The architecture associated with the inferior through the
 496      connection to the target.
 497
 498      The architecture vector provides some information that is really
 499      a property of the inferior, accessed through a particular target:
 500      ptrace operations; the layout of certain RSP packets; the
 501      solib_ops vector; etc.  To differentiate architecture accesses to
 502      per-inferior/target properties from
 503      per-thread/per-frame/per-objfile properties, accesses to
 504      per-inferior/target properties should be made through
 505      this gdbarch.  */
 506   struct gdbarch *gdbarch = NULL;
 507
 508   /* Data related to displaced stepping.  */
 509   displaced_step_inferior_state displaced_step_state;
 510
 511   /* Per inferior data-pointers required by other GDB modules.  */
 512   REGISTRY_FIELDS;
 513 };
 514
 515 /* Keep a registry of per-inferior data-pointers required by other GDB
 516    modules.  */
 517
 518 DECLARE_REGISTRY (inferior);
 519
 520 /* Add an inferior to the inferior list, print a message that a new
 521    inferior is found, and return the pointer to the new inferior.
 522    Caller may use this pointer to initialize the private inferior
 523    data.  */
 524 extern struct inferior *add_inferior (int pid);
 525
 526 /* Same as add_inferior, but don't print new inferior notifications to
 527    the CLI.  */
 528 extern struct inferior *add_inferior_silent (int pid);
 529
 530 extern void delete_inferior (struct inferior *todel);
 531
 532 /* Delete an existing inferior list entry, due to inferior detaching.  */
 533 extern void detach_inferior (inferior *inf);
 534
 535 extern void exit_inferior (inferior *inf);
 536
 537 extern void exit_inferior_silent (inferior *inf);
 538
 539 extern void exit_inferior_num_silent (int num);
 540
 541 extern void inferior_appeared (struct inferior *inf, int pid);
 542
 543 /* Get rid of all inferiors.  */
 544 extern void discard_all_inferiors (void);
 545
 546 /* Search function to lookup an inferior by target 'pid'.  */
 547 extern struct inferior *find_inferior_pid (int pid);
 548
 549 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 550 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 551
 552 /* Search function to lookup an inferior by GDB 'num'.  */
 553 extern struct inferior *find_inferior_id (int num);
 554
 555 /* Find an inferior bound to PSPACE, giving preference to the current
 556    inferior.  */
 557 extern struct inferior *
 558   find_inferior_for_program_space (struct program_space *pspace);
 559
 560 /* Inferior iterator function.
 561
 562    Calls a callback function once for each inferior, so long as the
 563    callback function returns false.  If the callback function returns
 564    true, the iteration will end and the current inferior will be
 565    returned.  This can be useful for implementing a search for a
 566    inferior with arbitrary attributes, or for applying some operation
 567    to every inferior.
 568
 569    It is safe to delete the iterated inferior from the callback.  */
 570 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 571                                                          void *),
 572                                                 void *);
 573
 574 /* Returns true if the inferior list is not empty.  */
 575 extern int have_inferiors (void);
 576
 577 /* Returns the number of live inferiors (real live processes).  */
 578 extern int number_of_live_inferiors (void);
 579
 580 /* Returns true if there are any live inferiors in the inferior list
 581    (not cores, not executables, real live processes).  */
 582 extern int have_live_inferiors (void);
 583
 584 /* Save/restore the current inferior.  */
 585
 586 class scoped_restore_current_inferior
 587 {
 588 public:
 589   scoped_restore_current_inferior ()
 590     : m_saved_inf (current_inferior ())
 591   {}
 592
 593   ~scoped_restore_current_inferior ()
 594   { set_current_inferior (m_saved_inf); }
 595
 596   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 597
 598 private:
 599   inferior *m_saved_inf;
 600 };
 601
 602
 603 /* Traverse all inferiors.  */
 604
 605 extern struct inferior *inferior_list;
 606
 607 /* Pull in the internals of the inferiors ranges and iterators.  Must
 608    be done after struct inferior is defined.  */
 609 #include "inferior-iter.h"
 610
 611 /* Return a range that can be used to walk over all inferiors
 612    inferiors, with range-for, safely.  I.e., it is safe to delete the
 613    currently-iterated inferior.  When combined with range-for, this
 614    allow convenient patterns like this:
 615
 616      for (inferior *inf : all_inferiors_safe ())
 617        if (some_condition ())
 618          delete inf;
 619 */
 620
 621 inline all_inferiors_safe_range
 622 all_inferiors_safe ()
 623 {
 624   return {};
 625 }
 626
 627 /* Returns a range representing all inferiors, suitable to use with
 628    range-for, like this:
 629
 630    for (inferior *inf : all_inferiors ())
 631      [...]
 632 */
 633
 634 inline all_inferiors_range
 635 all_inferiors ()
 636 {
 637   return {};
 638 }
 639
 640 /* Return a range that can be used to walk over all inferiors with PID
 641    not zero, with range-for.  */
 642
 643 inline all_non_exited_inferiors_range
 644 all_non_exited_inferiors ()
 645 {
 646   return {};
 647 }
 648
 649 /* Prune away automatically added inferiors that aren't required
 650    anymore.  */
 651 extern void prune_inferiors (void);
 652
 653 extern int number_of_inferiors (void);
 654
 655 extern struct inferior *add_inferior_with_spaces (void);
 656
 657 /* Print the current selected inferior.  */
 658 extern void print_selected_inferior (struct ui_out *uiout);
 659
 660 #endif /* !defined (INFERIOR_H) */