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) 1986-2018 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
  57 struct infcall_suspend_state;
  58 struct infcall_control_state;
  59
  60 extern struct infcall_suspend_state *save_infcall_suspend_state (void);
  61 extern struct infcall_control_state *save_infcall_control_state (void);
  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 extern struct cleanup *make_cleanup_restore_infcall_suspend_state
  67                                             (struct infcall_suspend_state *);
  68 extern struct cleanup *make_cleanup_restore_infcall_control_state
  69                                             (struct infcall_control_state *);
  70
  71 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
  72 extern void discard_infcall_control_state (struct infcall_control_state *);
  73
  74 extern readonly_detached_regcache *
  75   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
  76
  77 extern void set_sigint_trap (void);
  78
  79 extern void clear_sigint_trap (void);
  80
  81 /* Set/get file name for default use for standard in/out in the inferior.  */
  82
  83 extern void set_inferior_io_terminal (const char *terminal_name);
  84 extern const char *get_inferior_io_terminal (void);
  85
  86 /* Collected pid, tid, etc. of the debugged inferior.  When there's
  87    no inferior, inferior_ptid.pid () will be 0.  */
  88
  89 extern ptid_t inferior_ptid;
  90
  91 extern void generic_mourn_inferior (void);
  92
  93 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
  94                                               struct type *type,
  95                                               const gdb_byte *buf);
  96 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
  97                                          struct type *type, gdb_byte *buf,
  98                                          CORE_ADDR addr);
  99 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 100                                             struct type *type,
 101                                             const gdb_byte *buf);
 102 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 103                                        struct type *type, gdb_byte *buf,
 104                                        CORE_ADDR addr);
 105
 106 extern void reopen_exec_file (void);
 107
 108 /* From misc files */
 109
 110 extern void default_print_registers_info (struct gdbarch *gdbarch,
 111                                           struct ui_file *file,
 112                                           struct frame_info *frame,
 113                                           int regnum, int all);
 114
 115 /* Default implementation of gdbarch_print_float_info.  Print
 116    the values of all floating point registers.  */
 117
 118 extern void default_print_float_info (struct gdbarch *gdbarch,
 119                                       struct ui_file *file,
 120                                       struct frame_info *frame,
 121                                       const char *args);
 122
 123 extern void child_terminal_info (struct target_ops *self, const char *, int);
 124
 125 extern void info_terminal_command (char *, int);
 126
 127 extern void child_terminal_ours (struct target_ops *self);
 128
 129 extern void child_terminal_ours_for_output (struct target_ops *self);
 130
 131 extern void child_terminal_inferior (struct target_ops *self);
 132
 133 extern void child_terminal_save_inferior (struct target_ops *self);
 134
 135 extern void child_terminal_init (struct target_ops *self);
 136
 137 extern void child_terminal_init_with_pgrp (int pgrp);
 138
 139 extern void child_pass_ctrlc (struct target_ops *self);
 140
 141 extern void child_interrupt (struct target_ops *self);
 142
 143 /* From fork-child.c */
 144
 145 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 146    This function already calls set_executing.  Return the ptid_t from
 147    STARTUP_INFERIOR.  */
 148 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 149
 150 extern char *construct_inferior_arguments (int, char **);
 151
 152 /* From infcmd.c */
 153
 154 /* Initial inferior setup.  Determines the exec file is not yet known,
 155    takes any necessary post-attaching actions, fetches the target
 156    description and syncs the shared library list.  */
 157
 158 extern void setup_inferior (int from_tty);
 159
 160 extern void post_create_inferior (struct target_ops *, int);
 161
 162 extern void attach_command (const char *, int);
 163
 164 extern const char *get_inferior_args (void);
 165
 166 extern void set_inferior_args (const char *);
 167
 168 extern void set_inferior_args_vector (int, char **);
 169
 170 extern void registers_info (const char *, int);
 171
 172 extern void continue_1 (int all_threads);
 173
 174 extern void interrupt_target_1 (int all_threads);
 175
 176 extern void delete_longjmp_breakpoint_cleanup (void *arg);
 177
 178 extern void detach_command (const char *, int);
 179
 180 extern void notice_new_inferior (struct thread_info *, int, int);
 181
 182 extern struct value *get_return_value (struct value *function,
 183                                        struct type *value_type);
 184
 185 /* Prepare for execution command.  TARGET is the target that will run
 186    the command.  BACKGROUND determines whether this is a foreground
 187    (synchronous) or background (asynchronous) command.  */
 188
 189 extern void prepare_execution_command (struct target_ops *target,
 190                                        int background);
 191
 192 /* Whether to start up the debuggee under a shell.
 193
 194    If startup-with-shell is set, GDB's "run" will attempt to start up
 195    the debuggee under a shell.
 196
 197    This is in order for argument-expansion to occur.  E.g.,
 198
 199    (gdb) run *
 200
 201    The "*" gets expanded by the shell into a list of files.
 202
 203    While this is a nice feature, it may be handy to bypass the shell
 204    in some cases.  To disable this feature, do "set startup-with-shell
 205    false".
 206
 207    The catch-exec traps expected during start-up will be one more if
 208    the target is started up with a shell.  */
 209 extern int startup_with_shell;
 210
 211 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 212
 213 extern enum stop_stack_kind stop_stack_dummy;
 214
 215 /* Nonzero if program stopped due to a random (unexpected) signal in
 216    inferior process.  */
 217
 218 extern int stopped_by_random_signal;
 219
 220 /* Print notices on inferior events (attach, detach, etc.), set with
 221    `set print inferior-events'.  */
 222 extern int print_inferior_events;
 223
 224 /* STEP_OVER_ALL means step over all subroutine calls.
 225    STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
 226    STEP_OVER_NONE means don't step over any subroutine calls.  */
 227
 228 enum step_over_calls_kind
 229   {
 230     STEP_OVER_NONE,
 231     STEP_OVER_ALL,
 232     STEP_OVER_UNDEBUGGABLE
 233   };
 234
 235 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 236    will handle it themselves.  STOP_QUIETLY is used when running in
 237    the shell before the child program has been exec'd and when running
 238    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 239    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 240    except that there is no need to hide a signal.  */
 241
 242 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 243    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 244    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 245    a ptraced process has changed.  Earlier versions of the kernel
 246    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 247    other signal, i.e. it is not muffled.
 248
 249    If the gdb user does a 'continue' after the 'attach', gdb passes
 250    the global variable stop_signal (which stores the signal from the
 251    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 252    problematic, because the kernel doesn't ignore such SIGSTOP
 253    now.  I.e. it is reported back to gdb, which in turn presents it
 254    back to the user.
 255
 256    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 257    gdb to clear the value of stop_signal after the attach, so that it
 258    is not passed back down to the kernel.  */
 259
 260 enum stop_kind
 261   {
 262     NO_STOP_QUIETLY = 0,
 263     STOP_QUIETLY,
 264     STOP_QUIETLY_REMOTE,
 265     STOP_QUIETLY_NO_SIGSTOP
 266   };
 267
 268 \f
 269 /* Possible values for gdbarch_call_dummy_location.  */
 270 #define ON_STACK 1
 271 #define AT_ENTRY_POINT 4
 272
 273 /* Base class for target-specific inferior data.  */
 274
 275 struct private_inferior
 276 {
 277   virtual ~private_inferior () = 0;
 278 };
 279
 280 /* Inferior process specific part of `struct infcall_control_state'.
 281
 282    Inferior thread counterpart is `struct thread_control_state'.  */
 283
 284 struct inferior_control_state
 285 {
 286   /* See the definition of stop_kind above.  */
 287   enum stop_kind stop_soon;
 288 };
 289
 290 /* Return a pointer to the current inferior.  */
 291 extern inferior *current_inferior ();
 292
 293 extern void set_current_inferior (inferior *);
 294
 295 /* GDB represents the state of each program execution with an object
 296    called an inferior.  An inferior typically corresponds to a process
 297    but is more general and applies also to targets that do not have a
 298    notion of processes.  Each run of an executable creates a new
 299    inferior, as does each attachment to an existing process.
 300    Inferiors have unique internal identifiers that are different from
 301    target process ids.  Each inferior may in turn have multiple
 302    threads running in it.
 303
 304    Inferiors are intrusively refcounted objects.  Unlike thread
 305    objects, being the user-selected inferior is considered a strong
 306    reference and is thus accounted for in the inferior object's
 307    refcount (see set_current_inferior).  When GDB needs to remember
 308    the selected inferior to later restore it, GDB temporarily bumps
 309    the inferior object's refcount, to prevent something deleting the
 310    inferior object before reverting back (e.g., due to a
 311    "remove-inferiors" command (see
 312    make_cleanup_restore_current_thread).  All other inferior
 313    references are considered weak references.  Inferiors are always
 314    listed exactly once in the inferior list, so placing an inferior in
 315    the inferior list is an implicit, not counted strong reference.  */
 316
 317 class inferior : public refcounted_object
 318 {
 319 public:
 320   explicit inferior (int pid);
 321   ~inferior ();
 322
 323   /* Returns true if we can delete this inferior.  */
 324   bool deletable () const { return refcount () == 0; }
 325
 326   /* Pointer to next inferior in singly-linked list of inferiors.  */
 327   struct inferior *next = NULL;
 328
 329   /* Convenient handle (GDB inferior id).  Unique across all
 330      inferiors.  */
 331   int num = 0;
 332
 333   /* Actual target inferior id, usually, a process id.  This matches
 334      the ptid_t.pid member of threads of this inferior.  */
 335   int pid = 0;
 336   /* True if the PID was actually faked by GDB.  */
 337   bool fake_pid_p = false;
 338
 339   /* The highest thread number this inferior ever had.  */
 340   int highest_thread_num = 0;
 341
 342   /* State of GDB control of inferior process execution.
 343      See `struct inferior_control_state'.  */
 344   inferior_control_state control {NO_STOP_QUIETLY};
 345
 346   /* True if this was an auto-created inferior, e.g. created from
 347      following a fork; false, if this inferior was manually added by
 348      the user, and we should not attempt to prune it
 349      automatically.  */
 350   bool removable = false;
 351
 352   /* The address space bound to this inferior.  */
 353   struct address_space *aspace = NULL;
 354
 355   /* The program space bound to this inferior.  */
 356   struct program_space *pspace = NULL;
 357
 358   /* The arguments string to use when running.  */
 359   char *args = NULL;
 360
 361   /* The size of elements in argv.  */
 362   int argc = 0;
 363
 364   /* The vector version of arguments.  If ARGC is nonzero,
 365      then we must compute ARGS from this (via the target).
 366      This is always coming from main's argv and therefore
 367      should never be freed.  */
 368   char **argv = NULL;
 369
 370   /* The current working directory that will be used when starting
 371      this inferior.  */
 372   gdb::unique_xmalloc_ptr<char> cwd;
 373
 374   /* The name of terminal device to use for I/O.  */
 375   char *terminal = NULL;
 376
 377   /* The terminal state as set by the last target_terminal::terminal_*
 378      call.  */
 379   target_terminal_state terminal_state = target_terminal_state::is_ours;
 380
 381   /* Environment to use for running inferior,
 382      in format described in environ.h.  */
 383   gdb_environ environment;
 384
 385   /* True if this child process was attached rather than forked.  */
 386   bool attach_flag = false;
 387
 388   /* If this inferior is a vfork child, then this is the pointer to
 389      its vfork parent, if GDB is still attached to it.  */
 390   inferior *vfork_parent = NULL;
 391
 392   /* If this process is a vfork parent, this is the pointer to the
 393      child.  Since a vfork parent is left frozen by the kernel until
 394      the child execs or exits, a process can only have one vfork child
 395      at a given time.  */
 396   inferior *vfork_child = NULL;
 397
 398   /* True if this inferior should be detached when it's vfork sibling
 399      exits or execs.  */
 400   bool pending_detach = false;
 401
 402   /* True if this inferior is a vfork parent waiting for a vfork child
 403      not under our control to be done with the shared memory region,
 404      either by exiting or execing.  */
 405   bool waiting_for_vfork_done = false;
 406
 407   /* True if we're in the process of detaching from this inferior.  */
 408   bool detaching = false;
 409
 410   /* What is left to do for an execution command after any thread of
 411      this inferior stops.  For continuations associated with a
 412      specific thread, see `struct thread_info'.  */
 413   continuation *continuations = NULL;
 414
 415   /* True if setup_inferior wasn't called for this inferior yet.
 416      Until that is done, we must not access inferior memory or
 417      registers, as we haven't determined the target
 418      architecture/description.  */
 419   bool needs_setup = false;
 420
 421   /* Private data used by the target vector implementation.  */
 422   std::unique_ptr<private_inferior> priv;
 423
 424   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 425      In this case, the EXIT_CODE field is also valid.  */
 426   bool has_exit_code = false;
 427   LONGEST exit_code = 0;
 428
 429   /* Default flags to pass to the symbol reading functions.  These are
 430      used whenever a new objfile is created.  */
 431   symfile_add_flags symfile_flags = 0;
 432
 433   /* Info about an inferior's target description (if it's fetched; the
 434      user supplied description's filename, if any; etc.).  */
 435   target_desc_info *tdesc_info = NULL;
 436
 437   /* The architecture associated with the inferior through the
 438      connection to the target.
 439
 440      The architecture vector provides some information that is really
 441      a property of the inferior, accessed through a particular target:
 442      ptrace operations; the layout of certain RSP packets; the
 443      solib_ops vector; etc.  To differentiate architecture accesses to
 444      per-inferior/target properties from
 445      per-thread/per-frame/per-objfile properties, accesses to
 446      per-inferior/target properties should be made through
 447      this gdbarch.  */
 448   struct gdbarch *gdbarch = NULL;
 449
 450   /* Per inferior data-pointers required by other GDB modules.  */
 451   REGISTRY_FIELDS;
 452 };
 453
 454 /* Keep a registry of per-inferior data-pointers required by other GDB
 455    modules.  */
 456
 457 DECLARE_REGISTRY (inferior);
 458
 459 /* Add an inferior to the inferior list, print a message that a new
 460    inferior is found, and return the pointer to the new inferior.
 461    Caller may use this pointer to initialize the private inferior
 462    data.  */
 463 extern struct inferior *add_inferior (int pid);
 464
 465 /* Same as add_inferior, but don't print new inferior notifications to
 466    the CLI.  */
 467 extern struct inferior *add_inferior_silent (int pid);
 468
 469 extern void delete_inferior (struct inferior *todel);
 470
 471 /* Delete an existing inferior list entry, due to inferior detaching.  */
 472 extern void detach_inferior (inferior *inf);
 473
 474 extern void exit_inferior (inferior *inf);
 475
 476 extern void exit_inferior_silent (inferior *inf);
 477
 478 extern void exit_inferior_num_silent (int num);
 479
 480 extern void inferior_appeared (struct inferior *inf, int pid);
 481
 482 /* Get rid of all inferiors.  */
 483 extern void discard_all_inferiors (void);
 484
 485 /* Search function to lookup an inferior by target 'pid'.  */
 486 extern struct inferior *find_inferior_pid (int pid);
 487
 488 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 489 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 490
 491 /* Search function to lookup an inferior by GDB 'num'.  */
 492 extern struct inferior *find_inferior_id (int num);
 493
 494 /* Find an inferior bound to PSPACE, giving preference to the current
 495    inferior.  */
 496 extern struct inferior *
 497   find_inferior_for_program_space (struct program_space *pspace);
 498
 499 /* Inferior iterator function.
 500
 501    Calls a callback function once for each inferior, so long as the
 502    callback function returns false.  If the callback function returns
 503    true, the iteration will end and the current inferior will be
 504    returned.  This can be useful for implementing a search for a
 505    inferior with arbitrary attributes, or for applying some operation
 506    to every inferior.
 507
 508    It is safe to delete the iterated inferior from the callback.  */
 509 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 510                                                          void *),
 511                                                 void *);
 512
 513 /* Returns true if the inferior list is not empty.  */
 514 extern int have_inferiors (void);
 515
 516 /* Returns the number of live inferiors (real live processes).  */
 517 extern int number_of_live_inferiors (void);
 518
 519 /* Returns true if there are any live inferiors in the inferior list
 520    (not cores, not executables, real live processes).  */
 521 extern int have_live_inferiors (void);
 522
 523 /* Save/restore the current inferior.  */
 524
 525 class scoped_restore_current_inferior
 526 {
 527 public:
 528   scoped_restore_current_inferior ()
 529     : m_saved_inf (current_inferior ())
 530   {}
 531
 532   ~scoped_restore_current_inferior ()
 533   { set_current_inferior (m_saved_inf); }
 534
 535   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 536
 537 private:
 538   inferior *m_saved_inf;
 539 };
 540
 541
 542 /* Traverse all inferiors.  */
 543
 544 #define ALL_INFERIORS(I) \
 545   for ((I) = inferior_list; (I); (I) = (I)->next)
 546
 547 /* Traverse all non-exited inferiors.  */
 548
 549 #define ALL_NON_EXITED_INFERIORS(I) \
 550   ALL_INFERIORS (I)                 \
 551     if ((I)->pid != 0)
 552
 553 extern struct inferior *inferior_list;
 554
 555 /* Prune away automatically added inferiors that aren't required
 556    anymore.  */
 557 extern void prune_inferiors (void);
 558
 559 extern int number_of_inferiors (void);
 560
 561 extern struct inferior *add_inferior_with_spaces (void);
 562
 563 /* Print the current selected inferior.  */
 564 extern void print_selected_inferior (struct ui_out *uiout);
 565
 566 #endif /* !defined (INFERIOR_H) */