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     try
  72       {
  73         restore_infcall_suspend_state (state);
  74       }
  75     catch (const gdb_exception_error &e)
  76       {
  77         /* If we are restoring the inferior state due to an exception,
  78            some error message will be printed.  So, only warn the user
  79            when we cannot restore during normal execution.  */
  80         if (!std::uncaught_exception ())
  81           warning (_("Failed to restore inferior state: %s"), e.what ());
  82       }
  83   }
  84 };
  85
  86 /* A unique_ptr specialization for infcall_suspend_state.  */
  87 typedef std::unique_ptr<infcall_suspend_state, infcall_suspend_state_deleter>
  88     infcall_suspend_state_up;
  89
  90 extern infcall_suspend_state_up save_infcall_suspend_state ();
  91
  92 /* A deleter for infcall_control_state that calls
  93    restore_infcall_control_state.  */
  94 struct infcall_control_state_deleter
  95 {
  96   void operator() (struct infcall_control_state *state) const
  97   {
  98     restore_infcall_control_state (state);
  99   }
 100 };
 101
 102 /* A unique_ptr specialization for infcall_control_state.  */
 103 typedef std::unique_ptr<infcall_control_state, infcall_control_state_deleter>
 104     infcall_control_state_up;
 105
 106 extern infcall_control_state_up save_infcall_control_state ();
 107
 108 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
 109 extern void discard_infcall_control_state (struct infcall_control_state *);
 110
 111 extern readonly_detached_regcache *
 112   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
 113
 114 extern void set_sigint_trap (void);
 115
 116 extern void clear_sigint_trap (void);
 117
 118 /* Set/get file name for default use for standard in/out in the inferior.  */
 119
 120 extern void set_inferior_io_terminal (const char *terminal_name);
 121 extern const char *get_inferior_io_terminal (void);
 122
 123 /* Collected pid, tid, etc. of the debugged inferior.  When there's
 124    no inferior, inferior_ptid.pid () will be 0.  */
 125
 126 extern ptid_t inferior_ptid;
 127
 128 extern void generic_mourn_inferior (void);
 129
 130 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
 131                                               struct type *type,
 132                                               const gdb_byte *buf);
 133 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
 134                                          struct type *type, gdb_byte *buf,
 135                                          CORE_ADDR addr);
 136 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 137                                             struct type *type,
 138                                             const gdb_byte *buf);
 139 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 140                                        struct type *type, gdb_byte *buf,
 141                                        CORE_ADDR addr);
 142
 143 extern void reopen_exec_file (void);
 144
 145 /* From misc files */
 146
 147 extern void default_print_registers_info (struct gdbarch *gdbarch,
 148                                           struct ui_file *file,
 149                                           struct frame_info *frame,
 150                                           int regnum, int all);
 151
 152 /* Default implementation of gdbarch_print_float_info.  Print
 153    the values of all floating point registers.  */
 154
 155 extern void default_print_float_info (struct gdbarch *gdbarch,
 156                                       struct ui_file *file,
 157                                       struct frame_info *frame,
 158                                       const char *args);
 159
 160 extern void child_terminal_info (struct target_ops *self, const char *, int);
 161
 162 extern void info_terminal_command (char *, int);
 163
 164 extern void child_terminal_ours (struct target_ops *self);
 165
 166 extern void child_terminal_ours_for_output (struct target_ops *self);
 167
 168 extern void child_terminal_inferior (struct target_ops *self);
 169
 170 extern void child_terminal_save_inferior (struct target_ops *self);
 171
 172 extern void child_terminal_init (struct target_ops *self);
 173
 174 extern void child_terminal_init_with_pgrp (int pgrp);
 175
 176 extern void child_pass_ctrlc (struct target_ops *self);
 177
 178 extern void child_interrupt (struct target_ops *self);
 179
 180 /* From fork-child.c */
 181
 182 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 183    This function already calls set_executing.  Return the ptid_t from
 184    STARTUP_INFERIOR.  */
 185 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 186
 187 extern char *construct_inferior_arguments (int, char **);
 188
 189 /* From infcmd.c */
 190
 191 /* Initial inferior setup.  Determines the exec file is not yet known,
 192    takes any necessary post-attaching actions, fetches the target
 193    description and syncs the shared library list.  */
 194
 195 extern void setup_inferior (int from_tty);
 196
 197 extern void post_create_inferior (struct target_ops *, int);
 198
 199 extern void attach_command (const char *, int);
 200
 201 extern const char *get_inferior_args (void);
 202
 203 extern void set_inferior_args (const char *);
 204
 205 extern void set_inferior_args_vector (int, char **);
 206
 207 extern void registers_info (const char *, int);
 208
 209 extern void continue_1 (int all_threads);
 210
 211 extern void interrupt_target_1 (int all_threads);
 212
 213 using delete_longjmp_breakpoint_cleanup
 214   = FORWARD_SCOPE_EXIT (delete_longjmp_breakpoint);
 215
 216 extern void detach_command (const char *, int);
 217
 218 extern void notice_new_inferior (struct thread_info *, int, int);
 219
 220 extern struct value *get_return_value (struct value *function,
 221                                        struct type *value_type);
 222
 223 /* Prepare for execution command.  TARGET is the target that will run
 224    the command.  BACKGROUND determines whether this is a foreground
 225    (synchronous) or background (asynchronous) command.  */
 226
 227 extern void prepare_execution_command (struct target_ops *target,
 228                                        int background);
 229
 230 /* Whether to start up the debuggee under a shell.
 231
 232    If startup-with-shell is set, GDB's "run" will attempt to start up
 233    the debuggee under a shell.
 234
 235    This is in order for argument-expansion to occur.  E.g.,
 236
 237    (gdb) run *
 238
 239    The "*" gets expanded by the shell into a list of files.
 240
 241    While this is a nice feature, it may be handy to bypass the shell
 242    in some cases.  To disable this feature, do "set startup-with-shell
 243    false".
 244
 245    The catch-exec traps expected during start-up will be one more if
 246    the target is started up with a shell.  */
 247 extern int startup_with_shell;
 248
 249 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 250
 251 extern enum stop_stack_kind stop_stack_dummy;
 252
 253 /* Nonzero if program stopped due to a random (unexpected) signal in
 254    inferior process.  */
 255
 256 extern int stopped_by_random_signal;
 257
 258 /* Print notices on inferior events (attach, detach, etc.), set with
 259    `set print inferior-events'.  */
 260 extern int print_inferior_events;
 261
 262 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 263    will handle it themselves.  STOP_QUIETLY is used when running in
 264    the shell before the child program has been exec'd and when running
 265    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 266    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 267    except that there is no need to hide a signal.  */
 268
 269 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 270    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 271    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 272    a ptraced process has changed.  Earlier versions of the kernel
 273    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 274    other signal, i.e. it is not muffled.
 275
 276    If the gdb user does a 'continue' after the 'attach', gdb passes
 277    the global variable stop_signal (which stores the signal from the
 278    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 279    problematic, because the kernel doesn't ignore such SIGSTOP
 280    now.  I.e. it is reported back to gdb, which in turn presents it
 281    back to the user.
 282
 283    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 284    gdb to clear the value of stop_signal after the attach, so that it
 285    is not passed back down to the kernel.  */
 286
 287 enum stop_kind
 288   {
 289     NO_STOP_QUIETLY = 0,
 290     STOP_QUIETLY,
 291     STOP_QUIETLY_REMOTE,
 292     STOP_QUIETLY_NO_SIGSTOP
 293   };
 294
 295 \f
 296 /* Possible values for gdbarch_call_dummy_location.  */
 297 #define ON_STACK 1
 298 #define AT_ENTRY_POINT 4
 299
 300 /* Base class for target-specific inferior data.  */
 301
 302 struct private_inferior
 303 {
 304   virtual ~private_inferior () = 0;
 305 };
 306
 307 /* Inferior process specific part of `struct infcall_control_state'.
 308
 309    Inferior thread counterpart is `struct thread_control_state'.  */
 310
 311 struct inferior_control_state
 312 {
 313   inferior_control_state ()
 314     : stop_soon (NO_STOP_QUIETLY)
 315   {
 316   }
 317
 318   explicit inferior_control_state (enum stop_kind when)
 319     : stop_soon (when)
 320   {
 321   }
 322
 323   /* See the definition of stop_kind above.  */
 324   enum stop_kind stop_soon;
 325 };
 326
 327 /* Return a pointer to the current inferior.  */
 328 extern inferior *current_inferior ();
 329
 330 extern void set_current_inferior (inferior *);
 331
 332 /* GDB represents the state of each program execution with an object
 333    called an inferior.  An inferior typically corresponds to a process
 334    but is more general and applies also to targets that do not have a
 335    notion of processes.  Each run of an executable creates a new
 336    inferior, as does each attachment to an existing process.
 337    Inferiors have unique internal identifiers that are different from
 338    target process ids.  Each inferior may in turn have multiple
 339    threads running in it.
 340
 341    Inferiors are intrusively refcounted objects.  Unlike thread
 342    objects, being the user-selected inferior is considered a strong
 343    reference and is thus accounted for in the inferior object's
 344    refcount (see set_current_inferior).  When GDB needs to remember
 345    the selected inferior to later restore it, GDB temporarily bumps
 346    the inferior object's refcount, to prevent something deleting the
 347    inferior object before reverting back (e.g., due to a
 348    "remove-inferiors" command (see
 349    scoped_restore_current_inferior).  All other inferior
 350    references are considered weak references.  Inferiors are always
 351    listed exactly once in the inferior list, so placing an inferior in
 352    the inferior list is an implicit, not counted strong reference.  */
 353
 354 class inferior : public refcounted_object
 355 {
 356 public:
 357   explicit inferior (int pid);
 358   ~inferior ();
 359
 360   /* Returns true if we can delete this inferior.  */
 361   bool deletable () const { return refcount () == 0; }
 362
 363   /* Pointer to next inferior in singly-linked list of inferiors.  */
 364   struct inferior *next = NULL;
 365
 366   /* This inferior's thread list.  */
 367   thread_info *thread_list = nullptr;
 368
 369   /* Returns a range adapter covering the inferior's threads,
 370      including exited threads.  Used like this:
 371
 372        for (thread_info *thr : inf->threads ())
 373          { .... }
 374   */
 375   inf_threads_range threads ()
 376   { return inf_threads_range (this->thread_list); }
 377
 378   /* Returns a range adapter covering the inferior's non-exited
 379      threads.  Used like this:
 380
 381        for (thread_info *thr : inf->non_exited_threads ())
 382          { .... }
 383   */
 384   inf_non_exited_threads_range non_exited_threads ()
 385   { return inf_non_exited_threads_range (this->thread_list); }
 386
 387   /* Like inferior::threads(), but returns a range adapter that can be
 388      used with range-for, safely.  I.e., it is safe to delete the
 389      currently-iterated thread, like this:
 390
 391      for (thread_info *t : inf->threads_safe ())
 392        if (some_condition ())
 393          delete f;
 394   */
 395   inline safe_inf_threads_range threads_safe ()
 396   { return safe_inf_threads_range (this->thread_list); }
 397
 398   /* Convenient handle (GDB inferior id).  Unique across all
 399      inferiors.  */
 400   int num = 0;
 401
 402   /* Actual target inferior id, usually, a process id.  This matches
 403      the ptid_t.pid member of threads of this inferior.  */
 404   int pid = 0;
 405   /* True if the PID was actually faked by GDB.  */
 406   bool fake_pid_p = false;
 407
 408   /* The highest thread number this inferior ever had.  */
 409   int highest_thread_num = 0;
 410
 411   /* State of GDB control of inferior process execution.
 412      See `struct inferior_control_state'.  */
 413   inferior_control_state control;
 414
 415   /* True if this was an auto-created inferior, e.g. created from
 416      following a fork; false, if this inferior was manually added by
 417      the user, and we should not attempt to prune it
 418      automatically.  */
 419   bool removable = false;
 420
 421   /* The address space bound to this inferior.  */
 422   struct address_space *aspace = NULL;
 423
 424   /* The program space bound to this inferior.  */
 425   struct program_space *pspace = NULL;
 426
 427   /* The arguments string to use when running.  */
 428   char *args = NULL;
 429
 430   /* The size of elements in argv.  */
 431   int argc = 0;
 432
 433   /* The vector version of arguments.  If ARGC is nonzero,
 434      then we must compute ARGS from this (via the target).
 435      This is always coming from main's argv and therefore
 436      should never be freed.  */
 437   char **argv = NULL;
 438
 439   /* The current working directory that will be used when starting
 440      this inferior.  */
 441   gdb::unique_xmalloc_ptr<char> cwd;
 442
 443   /* The name of terminal device to use for I/O.  */
 444   char *terminal = NULL;
 445
 446   /* The terminal state as set by the last target_terminal::terminal_*
 447      call.  */
 448   target_terminal_state terminal_state = target_terminal_state::is_ours;
 449
 450   /* Environment to use for running inferior,
 451      in format described in environ.h.  */
 452   gdb_environ environment;
 453
 454   /* True if this child process was attached rather than forked.  */
 455   bool attach_flag = false;
 456
 457   /* If this inferior is a vfork child, then this is the pointer to
 458      its vfork parent, if GDB is still attached to it.  */
 459   inferior *vfork_parent = NULL;
 460
 461   /* If this process is a vfork parent, this is the pointer to the
 462      child.  Since a vfork parent is left frozen by the kernel until
 463      the child execs or exits, a process can only have one vfork child
 464      at a given time.  */
 465   inferior *vfork_child = NULL;
 466
 467   /* True if this inferior should be detached when it's vfork sibling
 468      exits or execs.  */
 469   bool pending_detach = false;
 470
 471   /* True if this inferior is a vfork parent waiting for a vfork child
 472      not under our control to be done with the shared memory region,
 473      either by exiting or execing.  */
 474   bool waiting_for_vfork_done = false;
 475
 476   /* True if we're in the process of detaching from this inferior.  */
 477   bool detaching = false;
 478
 479   /* What is left to do for an execution command after any thread of
 480      this inferior stops.  For continuations associated with a
 481      specific thread, see `struct thread_info'.  */
 482   continuation *continuations = NULL;
 483
 484   /* True if setup_inferior wasn't called for this inferior yet.
 485      Until that is done, we must not access inferior memory or
 486      registers, as we haven't determined the target
 487      architecture/description.  */
 488   bool needs_setup = false;
 489
 490   /* Private data used by the target vector implementation.  */
 491   std::unique_ptr<private_inferior> priv;
 492
 493   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 494      In this case, the EXIT_CODE field is also valid.  */
 495   bool has_exit_code = false;
 496   LONGEST exit_code = 0;
 497
 498   /* Default flags to pass to the symbol reading functions.  These are
 499      used whenever a new objfile is created.  */
 500   symfile_add_flags symfile_flags = 0;
 501
 502   /* Info about an inferior's target description (if it's fetched; the
 503      user supplied description's filename, if any; etc.).  */
 504   target_desc_info *tdesc_info = NULL;
 505
 506   /* The architecture associated with the inferior through the
 507      connection to the target.
 508
 509      The architecture vector provides some information that is really
 510      a property of the inferior, accessed through a particular target:
 511      ptrace operations; the layout of certain RSP packets; the
 512      solib_ops vector; etc.  To differentiate architecture accesses to
 513      per-inferior/target properties from
 514      per-thread/per-frame/per-objfile properties, accesses to
 515      per-inferior/target properties should be made through
 516      this gdbarch.  */
 517   struct gdbarch *gdbarch = NULL;
 518
 519   /* Data related to displaced stepping.  */
 520   displaced_step_inferior_state displaced_step_state;
 521
 522   /* Per inferior data-pointers required by other GDB modules.  */
 523   REGISTRY_FIELDS;
 524 };
 525
 526 /* Keep a registry of per-inferior data-pointers required by other GDB
 527    modules.  */
 528
 529 DECLARE_REGISTRY (inferior);
 530
 531 /* Add an inferior to the inferior list, print a message that a new
 532    inferior is found, and return the pointer to the new inferior.
 533    Caller may use this pointer to initialize the private inferior
 534    data.  */
 535 extern struct inferior *add_inferior (int pid);
 536
 537 /* Same as add_inferior, but don't print new inferior notifications to
 538    the CLI.  */
 539 extern struct inferior *add_inferior_silent (int pid);
 540
 541 extern void delete_inferior (struct inferior *todel);
 542
 543 /* Delete an existing inferior list entry, due to inferior detaching.  */
 544 extern void detach_inferior (inferior *inf);
 545
 546 extern void exit_inferior (inferior *inf);
 547
 548 extern void exit_inferior_silent (inferior *inf);
 549
 550 extern void exit_inferior_num_silent (int num);
 551
 552 extern void inferior_appeared (struct inferior *inf, int pid);
 553
 554 /* Get rid of all inferiors.  */
 555 extern void discard_all_inferiors (void);
 556
 557 /* Search function to lookup an inferior by target 'pid'.  */
 558 extern struct inferior *find_inferior_pid (int pid);
 559
 560 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 561 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 562
 563 /* Search function to lookup an inferior by GDB 'num'.  */
 564 extern struct inferior *find_inferior_id (int num);
 565
 566 /* Find an inferior bound to PSPACE, giving preference to the current
 567    inferior.  */
 568 extern struct inferior *
 569   find_inferior_for_program_space (struct program_space *pspace);
 570
 571 /* Inferior iterator function.
 572
 573    Calls a callback function once for each inferior, so long as the
 574    callback function returns false.  If the callback function returns
 575    true, the iteration will end and the current inferior will be
 576    returned.  This can be useful for implementing a search for a
 577    inferior with arbitrary attributes, or for applying some operation
 578    to every inferior.
 579
 580    It is safe to delete the iterated inferior from the callback.  */
 581 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 582                                                          void *),
 583                                                 void *);
 584
 585 /* Returns true if the inferior list is not empty.  */
 586 extern int have_inferiors (void);
 587
 588 /* Returns the number of live inferiors (real live processes).  */
 589 extern int number_of_live_inferiors (void);
 590
 591 /* Returns true if there are any live inferiors in the inferior list
 592    (not cores, not executables, real live processes).  */
 593 extern int have_live_inferiors (void);
 594
 595 /* Save/restore the current inferior.  */
 596
 597 class scoped_restore_current_inferior
 598 {
 599 public:
 600   scoped_restore_current_inferior ()
 601     : m_saved_inf (current_inferior ())
 602   {}
 603
 604   ~scoped_restore_current_inferior ()
 605   { set_current_inferior (m_saved_inf); }
 606
 607   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 608
 609 private:
 610   inferior *m_saved_inf;
 611 };
 612
 613
 614 /* Traverse all inferiors.  */
 615
 616 extern struct inferior *inferior_list;
 617
 618 /* Pull in the internals of the inferiors ranges and iterators.  Must
 619    be done after struct inferior is defined.  */
 620 #include "inferior-iter.h"
 621
 622 /* Return a range that can be used to walk over all inferiors
 623    inferiors, with range-for, safely.  I.e., it is safe to delete the
 624    currently-iterated inferior.  When combined with range-for, this
 625    allow convenient patterns like this:
 626
 627      for (inferior *inf : all_inferiors_safe ())
 628        if (some_condition ())
 629          delete inf;
 630 */
 631
 632 inline all_inferiors_safe_range
 633 all_inferiors_safe ()
 634 {
 635   return {};
 636 }
 637
 638 /* Returns a range representing all inferiors, suitable to use with
 639    range-for, like this:
 640
 641    for (inferior *inf : all_inferiors ())
 642      [...]
 643 */
 644
 645 inline all_inferiors_range
 646 all_inferiors ()
 647 {
 648   return {};
 649 }
 650
 651 /* Return a range that can be used to walk over all inferiors with PID
 652    not zero, with range-for.  */
 653
 654 inline all_non_exited_inferiors_range
 655 all_non_exited_inferiors ()
 656 {
 657   return {};
 658 }
 659
 660 /* Prune away automatically added inferiors that aren't required
 661    anymore.  */
 662 extern void prune_inferiors (void);
 663
 664 extern int number_of_inferiors (void);
 665
 666 extern struct inferior *add_inferior_with_spaces (void);
 667
 668 /* Print the current selected inferior.  */
 669 extern void print_selected_inferior (struct ui_out *uiout);
 670
 671 #endif /* !defined (INFERIOR_H) */