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 "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
  55 #include "common-inferior.h"
  56 #include "gdbthread.h"
  57
  58 struct infcall_suspend_state;
  59 struct infcall_control_state;
  60
  61 extern void restore_infcall_suspend_state (struct infcall_suspend_state *);
  62 extern void restore_infcall_control_state (struct infcall_control_state *);
  63
  64 /* A deleter for infcall_suspend_state that calls
  65    restore_infcall_suspend_state.  */
  66 struct infcall_suspend_state_deleter
  67 {
  68   void operator() (struct infcall_suspend_state *state) const
  69   {
  70     restore_infcall_suspend_state (state);
  71   }
  72 };
  73
  74 /* A unique_ptr specialization for infcall_suspend_state.  */
  75 typedef std::unique_ptr<infcall_suspend_state, infcall_suspend_state_deleter>
  76     infcall_suspend_state_up;
  77
  78 extern infcall_suspend_state_up save_infcall_suspend_state ();
  79
  80 /* A deleter for infcall_control_state that calls
  81    restore_infcall_control_state.  */
  82 struct infcall_control_state_deleter
  83 {
  84   void operator() (struct infcall_control_state *state) const
  85   {
  86     restore_infcall_control_state (state);
  87   }
  88 };
  89
  90 /* A unique_ptr specialization for infcall_control_state.  */
  91 typedef std::unique_ptr<infcall_control_state, infcall_control_state_deleter>
  92     infcall_control_state_up;
  93
  94 extern infcall_control_state_up save_infcall_control_state ();
  95
  96 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
  97 extern void discard_infcall_control_state (struct infcall_control_state *);
  98
  99 extern readonly_detached_regcache *
 100   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
 101
 102 extern void set_sigint_trap (void);
 103
 104 extern void clear_sigint_trap (void);
 105
 106 /* Set/get file name for default use for standard in/out in the inferior.  */
 107
 108 extern void set_inferior_io_terminal (const char *terminal_name);
 109 extern const char *get_inferior_io_terminal (void);
 110
 111 /* Collected pid, tid, etc. of the debugged inferior.  When there's
 112    no inferior, inferior_ptid.pid () will be 0.  */
 113
 114 extern ptid_t inferior_ptid;
 115
 116 extern void generic_mourn_inferior (void);
 117
 118 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
 119                                               struct type *type,
 120                                               const gdb_byte *buf);
 121 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
 122                                          struct type *type, gdb_byte *buf,
 123                                          CORE_ADDR addr);
 124 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 125                                             struct type *type,
 126                                             const gdb_byte *buf);
 127 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 128                                        struct type *type, gdb_byte *buf,
 129                                        CORE_ADDR addr);
 130
 131 extern void reopen_exec_file (void);
 132
 133 /* From misc files */
 134
 135 extern void default_print_registers_info (struct gdbarch *gdbarch,
 136                                           struct ui_file *file,
 137                                           struct frame_info *frame,
 138                                           int regnum, int all);
 139
 140 /* Default implementation of gdbarch_print_float_info.  Print
 141    the values of all floating point registers.  */
 142
 143 extern void default_print_float_info (struct gdbarch *gdbarch,
 144                                       struct ui_file *file,
 145                                       struct frame_info *frame,
 146                                       const char *args);
 147
 148 extern void child_terminal_info (struct target_ops *self, const char *, int);
 149
 150 extern void info_terminal_command (char *, int);
 151
 152 extern void child_terminal_ours (struct target_ops *self);
 153
 154 extern void child_terminal_ours_for_output (struct target_ops *self);
 155
 156 extern void child_terminal_inferior (struct target_ops *self);
 157
 158 extern void child_terminal_save_inferior (struct target_ops *self);
 159
 160 extern void child_terminal_init (struct target_ops *self);
 161
 162 extern void child_terminal_init_with_pgrp (int pgrp);
 163
 164 extern void child_pass_ctrlc (struct target_ops *self);
 165
 166 extern void child_interrupt (struct target_ops *self);
 167
 168 /* From fork-child.c */
 169
 170 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 171    This function already calls set_executing.  Return the ptid_t from
 172    STARTUP_INFERIOR.  */
 173 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 174
 175 extern char *construct_inferior_arguments (int, char **);
 176
 177 /* From infcmd.c */
 178
 179 /* Initial inferior setup.  Determines the exec file is not yet known,
 180    takes any necessary post-attaching actions, fetches the target
 181    description and syncs the shared library list.  */
 182
 183 extern void setup_inferior (int from_tty);
 184
 185 extern void post_create_inferior (struct target_ops *, int);
 186
 187 extern void attach_command (const char *, int);
 188
 189 extern const char *get_inferior_args (void);
 190
 191 extern void set_inferior_args (const char *);
 192
 193 extern void set_inferior_args_vector (int, char **);
 194
 195 extern void registers_info (const char *, int);
 196
 197 extern void continue_1 (int all_threads);
 198
 199 extern void interrupt_target_1 (int all_threads);
 200
 201 extern void delete_longjmp_breakpoint_cleanup (void *arg);
 202
 203 extern void detach_command (const char *, int);
 204
 205 extern void notice_new_inferior (struct thread_info *, int, int);
 206
 207 extern struct value *get_return_value (struct value *function,
 208                                        struct type *value_type);
 209
 210 /* Prepare for execution command.  TARGET is the target that will run
 211    the command.  BACKGROUND determines whether this is a foreground
 212    (synchronous) or background (asynchronous) command.  */
 213
 214 extern void prepare_execution_command (struct target_ops *target,
 215                                        int background);
 216
 217 /* Whether to start up the debuggee under a shell.
 218
 219    If startup-with-shell is set, GDB's "run" will attempt to start up
 220    the debuggee under a shell.
 221
 222    This is in order for argument-expansion to occur.  E.g.,
 223
 224    (gdb) run *
 225
 226    The "*" gets expanded by the shell into a list of files.
 227
 228    While this is a nice feature, it may be handy to bypass the shell
 229    in some cases.  To disable this feature, do "set startup-with-shell
 230    false".
 231
 232    The catch-exec traps expected during start-up will be one more if
 233    the target is started up with a shell.  */
 234 extern int startup_with_shell;
 235
 236 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 237
 238 extern enum stop_stack_kind stop_stack_dummy;
 239
 240 /* Nonzero if program stopped due to a random (unexpected) signal in
 241    inferior process.  */
 242
 243 extern int stopped_by_random_signal;
 244
 245 /* Print notices on inferior events (attach, detach, etc.), set with
 246    `set print inferior-events'.  */
 247 extern int print_inferior_events;
 248
 249 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 250    will handle it themselves.  STOP_QUIETLY is used when running in
 251    the shell before the child program has been exec'd and when running
 252    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 253    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 254    except that there is no need to hide a signal.  */
 255
 256 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 257    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 258    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 259    a ptraced process has changed.  Earlier versions of the kernel
 260    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 261    other signal, i.e. it is not muffled.
 262
 263    If the gdb user does a 'continue' after the 'attach', gdb passes
 264    the global variable stop_signal (which stores the signal from the
 265    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 266    problematic, because the kernel doesn't ignore such SIGSTOP
 267    now.  I.e. it is reported back to gdb, which in turn presents it
 268    back to the user.
 269
 270    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 271    gdb to clear the value of stop_signal after the attach, so that it
 272    is not passed back down to the kernel.  */
 273
 274 enum stop_kind
 275   {
 276     NO_STOP_QUIETLY = 0,
 277     STOP_QUIETLY,
 278     STOP_QUIETLY_REMOTE,
 279     STOP_QUIETLY_NO_SIGSTOP
 280   };
 281
 282 \f
 283 /* Possible values for gdbarch_call_dummy_location.  */
 284 #define ON_STACK 1
 285 #define AT_ENTRY_POINT 4
 286
 287 /* Base class for target-specific inferior data.  */
 288
 289 struct private_inferior
 290 {
 291   virtual ~private_inferior () = 0;
 292 };
 293
 294 /* Inferior process specific part of `struct infcall_control_state'.
 295
 296    Inferior thread counterpart is `struct thread_control_state'.  */
 297
 298 struct inferior_control_state
 299 {
 300   inferior_control_state ()
 301     : stop_soon (NO_STOP_QUIETLY)
 302   {
 303   }
 304
 305   explicit inferior_control_state (enum stop_kind when)
 306     : stop_soon (when)
 307   {
 308   }
 309
 310   /* See the definition of stop_kind above.  */
 311   enum stop_kind stop_soon;
 312 };
 313
 314 /* Return a pointer to the current inferior.  */
 315 extern inferior *current_inferior ();
 316
 317 extern void set_current_inferior (inferior *);
 318
 319 /* GDB represents the state of each program execution with an object
 320    called an inferior.  An inferior typically corresponds to a process
 321    but is more general and applies also to targets that do not have a
 322    notion of processes.  Each run of an executable creates a new
 323    inferior, as does each attachment to an existing process.
 324    Inferiors have unique internal identifiers that are different from
 325    target process ids.  Each inferior may in turn have multiple
 326    threads running in it.
 327
 328    Inferiors are intrusively refcounted objects.  Unlike thread
 329    objects, being the user-selected inferior is considered a strong
 330    reference and is thus accounted for in the inferior object's
 331    refcount (see set_current_inferior).  When GDB needs to remember
 332    the selected inferior to later restore it, GDB temporarily bumps
 333    the inferior object's refcount, to prevent something deleting the
 334    inferior object before reverting back (e.g., due to a
 335    "remove-inferiors" command (see
 336    make_cleanup_restore_current_thread).  All other inferior
 337    references are considered weak references.  Inferiors are always
 338    listed exactly once in the inferior list, so placing an inferior in
 339    the inferior list is an implicit, not counted strong reference.  */
 340
 341 class inferior : public refcounted_object
 342 {
 343 public:
 344   explicit inferior (int pid);
 345   ~inferior ();
 346
 347   /* Returns true if we can delete this inferior.  */
 348   bool deletable () const { return refcount () == 0; }
 349
 350   /* Pointer to next inferior in singly-linked list of inferiors.  */
 351   struct inferior *next = NULL;
 352
 353   /* This inferior's thread list.  */
 354   thread_info *thread_list = nullptr;
 355
 356   /* Returns a range adapter covering the inferior's threads,
 357      including exited threads.  Used like this:
 358
 359        for (thread_info *thr : inf->threads ())
 360          { .... }
 361   */
 362   inf_threads_range threads ()
 363   { return inf_threads_range (this->thread_list); }
 364
 365   /* Returns a range adapter covering the inferior's non-exited
 366      threads.  Used like this:
 367
 368        for (thread_info *thr : inf->non_exited_threads ())
 369          { .... }
 370   */
 371   inf_non_exited_threads_range non_exited_threads ()
 372   { return inf_non_exited_threads_range (this->thread_list); }
 373
 374   /* Like inferior::threads(), but returns a range adapter that can be
 375      used with range-for, safely.  I.e., it is safe to delete the
 376      currently-iterated thread, like this:
 377
 378      for (thread_info *t : inf->threads_safe ())
 379        if (some_condition ())
 380          delete f;
 381   */
 382   inline safe_inf_threads_range threads_safe ()
 383   { return safe_inf_threads_range (this->thread_list); }
 384
 385   /* Convenient handle (GDB inferior id).  Unique across all
 386      inferiors.  */
 387   int num = 0;
 388
 389   /* Actual target inferior id, usually, a process id.  This matches
 390      the ptid_t.pid member of threads of this inferior.  */
 391   int pid = 0;
 392   /* True if the PID was actually faked by GDB.  */
 393   bool fake_pid_p = false;
 394
 395   /* The highest thread number this inferior ever had.  */
 396   int highest_thread_num = 0;
 397
 398   /* State of GDB control of inferior process execution.
 399      See `struct inferior_control_state'.  */
 400   inferior_control_state control;
 401
 402   /* True if this was an auto-created inferior, e.g. created from
 403      following a fork; false, if this inferior was manually added by
 404      the user, and we should not attempt to prune it
 405      automatically.  */
 406   bool removable = false;
 407
 408   /* The address space bound to this inferior.  */
 409   struct address_space *aspace = NULL;
 410
 411   /* The program space bound to this inferior.  */
 412   struct program_space *pspace = NULL;
 413
 414   /* The arguments string to use when running.  */
 415   char *args = NULL;
 416
 417   /* The size of elements in argv.  */
 418   int argc = 0;
 419
 420   /* The vector version of arguments.  If ARGC is nonzero,
 421      then we must compute ARGS from this (via the target).
 422      This is always coming from main's argv and therefore
 423      should never be freed.  */
 424   char **argv = NULL;
 425
 426   /* The current working directory that will be used when starting
 427      this inferior.  */
 428   gdb::unique_xmalloc_ptr<char> cwd;
 429
 430   /* The name of terminal device to use for I/O.  */
 431   char *terminal = NULL;
 432
 433   /* The terminal state as set by the last target_terminal::terminal_*
 434      call.  */
 435   target_terminal_state terminal_state = target_terminal_state::is_ours;
 436
 437   /* Environment to use for running inferior,
 438      in format described in environ.h.  */
 439   gdb_environ environment;
 440
 441   /* True if this child process was attached rather than forked.  */
 442   bool attach_flag = false;
 443
 444   /* If this inferior is a vfork child, then this is the pointer to
 445      its vfork parent, if GDB is still attached to it.  */
 446   inferior *vfork_parent = NULL;
 447
 448   /* If this process is a vfork parent, this is the pointer to the
 449      child.  Since a vfork parent is left frozen by the kernel until
 450      the child execs or exits, a process can only have one vfork child
 451      at a given time.  */
 452   inferior *vfork_child = NULL;
 453
 454   /* True if this inferior should be detached when it's vfork sibling
 455      exits or execs.  */
 456   bool pending_detach = false;
 457
 458   /* True if this inferior is a vfork parent waiting for a vfork child
 459      not under our control to be done with the shared memory region,
 460      either by exiting or execing.  */
 461   bool waiting_for_vfork_done = false;
 462
 463   /* True if we're in the process of detaching from this inferior.  */
 464   bool detaching = false;
 465
 466   /* What is left to do for an execution command after any thread of
 467      this inferior stops.  For continuations associated with a
 468      specific thread, see `struct thread_info'.  */
 469   continuation *continuations = NULL;
 470
 471   /* True if setup_inferior wasn't called for this inferior yet.
 472      Until that is done, we must not access inferior memory or
 473      registers, as we haven't determined the target
 474      architecture/description.  */
 475   bool needs_setup = false;
 476
 477   /* Private data used by the target vector implementation.  */
 478   std::unique_ptr<private_inferior> priv;
 479
 480   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 481      In this case, the EXIT_CODE field is also valid.  */
 482   bool has_exit_code = false;
 483   LONGEST exit_code = 0;
 484
 485   /* Default flags to pass to the symbol reading functions.  These are
 486      used whenever a new objfile is created.  */
 487   symfile_add_flags symfile_flags = 0;
 488
 489   /* Info about an inferior's target description (if it's fetched; the
 490      user supplied description's filename, if any; etc.).  */
 491   target_desc_info *tdesc_info = NULL;
 492
 493   /* The architecture associated with the inferior through the
 494      connection to the target.
 495
 496      The architecture vector provides some information that is really
 497      a property of the inferior, accessed through a particular target:
 498      ptrace operations; the layout of certain RSP packets; the
 499      solib_ops vector; etc.  To differentiate architecture accesses to
 500      per-inferior/target properties from
 501      per-thread/per-frame/per-objfile properties, accesses to
 502      per-inferior/target properties should be made through
 503      this gdbarch.  */
 504   struct gdbarch *gdbarch = NULL;
 505
 506   /* Data related to displaced stepping.  */
 507   displaced_step_inferior_state displaced_step_state;
 508
 509   /* Per inferior data-pointers required by other GDB modules.  */
 510   REGISTRY_FIELDS;
 511 };
 512
 513 /* Keep a registry of per-inferior data-pointers required by other GDB
 514    modules.  */
 515
 516 DECLARE_REGISTRY (inferior);
 517
 518 /* Add an inferior to the inferior list, print a message that a new
 519    inferior is found, and return the pointer to the new inferior.
 520    Caller may use this pointer to initialize the private inferior
 521    data.  */
 522 extern struct inferior *add_inferior (int pid);
 523
 524 /* Same as add_inferior, but don't print new inferior notifications to
 525    the CLI.  */
 526 extern struct inferior *add_inferior_silent (int pid);
 527
 528 extern void delete_inferior (struct inferior *todel);
 529
 530 /* Delete an existing inferior list entry, due to inferior detaching.  */
 531 extern void detach_inferior (inferior *inf);
 532
 533 extern void exit_inferior (inferior *inf);
 534
 535 extern void exit_inferior_silent (inferior *inf);
 536
 537 extern void exit_inferior_num_silent (int num);
 538
 539 extern void inferior_appeared (struct inferior *inf, int pid);
 540
 541 /* Get rid of all inferiors.  */
 542 extern void discard_all_inferiors (void);
 543
 544 /* Search function to lookup an inferior by target 'pid'.  */
 545 extern struct inferior *find_inferior_pid (int pid);
 546
 547 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 548 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 549
 550 /* Search function to lookup an inferior by GDB 'num'.  */
 551 extern struct inferior *find_inferior_id (int num);
 552
 553 /* Find an inferior bound to PSPACE, giving preference to the current
 554    inferior.  */
 555 extern struct inferior *
 556   find_inferior_for_program_space (struct program_space *pspace);
 557
 558 /* Inferior iterator function.
 559
 560    Calls a callback function once for each inferior, so long as the
 561    callback function returns false.  If the callback function returns
 562    true, the iteration will end and the current inferior will be
 563    returned.  This can be useful for implementing a search for a
 564    inferior with arbitrary attributes, or for applying some operation
 565    to every inferior.
 566
 567    It is safe to delete the iterated inferior from the callback.  */
 568 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 569                                                          void *),
 570                                                 void *);
 571
 572 /* Returns true if the inferior list is not empty.  */
 573 extern int have_inferiors (void);
 574
 575 /* Returns the number of live inferiors (real live processes).  */
 576 extern int number_of_live_inferiors (void);
 577
 578 /* Returns true if there are any live inferiors in the inferior list
 579    (not cores, not executables, real live processes).  */
 580 extern int have_live_inferiors (void);
 581
 582 /* Save/restore the current inferior.  */
 583
 584 class scoped_restore_current_inferior
 585 {
 586 public:
 587   scoped_restore_current_inferior ()
 588     : m_saved_inf (current_inferior ())
 589   {}
 590
 591   ~scoped_restore_current_inferior ()
 592   { set_current_inferior (m_saved_inf); }
 593
 594   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 595
 596 private:
 597   inferior *m_saved_inf;
 598 };
 599
 600
 601 /* Traverse all inferiors.  */
 602
 603 extern struct inferior *inferior_list;
 604
 605 /* Pull in the internals of the inferiors ranges and iterators.  Must
 606    be done after struct inferior is defined.  */
 607 #include "inferior-iter.h"
 608
 609 /* Return a range that can be used to walk over all inferiors
 610    inferiors, with range-for, safely.  I.e., it is safe to delete the
 611    currently-iterated inferior.  When combined with range-for, this
 612    allow convenient patterns like this:
 613
 614      for (inferior *inf : all_inferiors_safe ())
 615        if (some_condition ())
 616          delete inf;
 617 */
 618
 619 inline all_inferiors_safe_range
 620 all_inferiors_safe ()
 621 {
 622   return {};
 623 }
 624
 625 /* Returns a range representing all inferiors, suitable to use with
 626    range-for, like this:
 627
 628    for (inferior *inf : all_inferiors ())
 629      [...]
 630 */
 631
 632 inline all_inferiors_range
 633 all_inferiors ()
 634 {
 635   return {};
 636 }
 637
 638 /* Return a range that can be used to walk over all inferiors with PID
 639    not zero, with range-for.  */
 640
 641 inline all_non_exited_inferiors_range
 642 all_non_exited_inferiors ()
 643 {
 644   return {};
 645 }
 646
 647 /* Prune away automatically added inferiors that aren't required
 648    anymore.  */
 649 extern void prune_inferiors (void);
 650
 651 extern int number_of_inferiors (void);
 652
 653 extern struct inferior *add_inferior_with_spaces (void);
 654
 655 /* Print the current selected inferior.  */
 656 extern void print_selected_inferior (struct ui_out *uiout);
 657
 658 #endif /* !defined (INFERIOR_H) */