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