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, ptid_get_pid (inferior_ptid) 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 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 (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 /* Address at which inferior stopped.  */
 212
 213 extern CORE_ADDR stop_pc;
 214
 215 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 216
 217 extern enum stop_stack_kind stop_stack_dummy;
 218
 219 /* Nonzero if program stopped due to a random (unexpected) signal in
 220    inferior process.  */
 221
 222 extern int stopped_by_random_signal;
 223
 224 /* Print notices on inferior events (attach, detach, etc.), set with
 225    `set print inferior-events'.  */
 226 extern int print_inferior_events;
 227
 228 /* STEP_OVER_ALL means step over all subroutine calls.
 229    STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
 230    STEP_OVER_NONE means don't step over any subroutine calls.  */
 231
 232 enum step_over_calls_kind
 233   {
 234     STEP_OVER_NONE,
 235     STEP_OVER_ALL,
 236     STEP_OVER_UNDEBUGGABLE
 237   };
 238
 239 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 240    will handle it themselves.  STOP_QUIETLY is used when running in
 241    the shell before the child program has been exec'd and when running
 242    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 243    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 244    except that there is no need to hide a signal.  */
 245
 246 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 247    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 248    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 249    a ptraced process has changed.  Earlier versions of the kernel
 250    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 251    other signal, i.e. it is not muffled.
 252
 253    If the gdb user does a 'continue' after the 'attach', gdb passes
 254    the global variable stop_signal (which stores the signal from the
 255    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 256    problematic, because the kernel doesn't ignore such SIGSTOP
 257    now.  I.e. it is reported back to gdb, which in turn presents it
 258    back to the user.
 259
 260    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 261    gdb to clear the value of stop_signal after the attach, so that it
 262    is not passed back down to the kernel.  */
 263
 264 enum stop_kind
 265   {
 266     NO_STOP_QUIETLY = 0,
 267     STOP_QUIETLY,
 268     STOP_QUIETLY_REMOTE,
 269     STOP_QUIETLY_NO_SIGSTOP
 270   };
 271
 272 \f
 273 /* Possible values for gdbarch_call_dummy_location.  */
 274 #define ON_STACK 1
 275 #define AT_ENTRY_POINT 4
 276
 277 /* Base class for target-specific inferior data.  */
 278
 279 struct private_inferior
 280 {
 281   virtual ~private_inferior () = 0;
 282 };
 283
 284 /* Inferior process specific part of `struct infcall_control_state'.
 285
 286    Inferior thread counterpart is `struct thread_control_state'.  */
 287
 288 struct inferior_control_state
 289 {
 290   /* See the definition of stop_kind above.  */
 291   enum stop_kind stop_soon;
 292 };
 293
 294 /* Return a pointer to the current inferior.  */
 295 extern inferior *current_inferior ();
 296
 297 extern void set_current_inferior (inferior *);
 298
 299 /* GDB represents the state of each program execution with an object
 300    called an inferior.  An inferior typically corresponds to a process
 301    but is more general and applies also to targets that do not have a
 302    notion of processes.  Each run of an executable creates a new
 303    inferior, as does each attachment to an existing process.
 304    Inferiors have unique internal identifiers that are different from
 305    target process ids.  Each inferior may in turn have multiple
 306    threads running in it.
 307
 308    Inferiors are intrusively refcounted objects.  Unlike thread
 309    objects, being the user-selected inferior is considered a strong
 310    reference and is thus accounted for in the inferior object's
 311    refcount (see set_current_inferior).  When GDB needs to remember
 312    the selected inferior to later restore it, GDB temporarily bumps
 313    the inferior object's refcount, to prevent something deleting the
 314    inferior object before reverting back (e.g., due to a
 315    "remove-inferiors" command (see
 316    make_cleanup_restore_current_thread).  All other inferior
 317    references are considered weak references.  Inferiors are always
 318    listed exactly once in the inferior list, so placing an inferior in
 319    the inferior list is an implicit, not counted strong reference.  */
 320
 321 class inferior : public refcounted_object
 322 {
 323 public:
 324   explicit inferior (int pid);
 325   ~inferior ();
 326
 327   /* Returns true if we can delete this inferior.  */
 328   bool deletable () const { return refcount () == 0; }
 329
 330   /* Pointer to next inferior in singly-linked list of inferiors.  */
 331   struct inferior *next = NULL;
 332
 333   /* Convenient handle (GDB inferior id).  Unique across all
 334      inferiors.  */
 335   int num = 0;
 336
 337   /* Actual target inferior id, usually, a process id.  This matches
 338      the ptid_t.pid member of threads of this inferior.  */
 339   int pid = 0;
 340   /* True if the PID was actually faked by GDB.  */
 341   bool fake_pid_p = false;
 342
 343   /* The highest thread number this inferior ever had.  */
 344   int highest_thread_num = 0;
 345
 346   /* State of GDB control of inferior process execution.
 347      See `struct inferior_control_state'.  */
 348   inferior_control_state control {NO_STOP_QUIETLY};
 349
 350   /* True if this was an auto-created inferior, e.g. created from
 351      following a fork; false, if this inferior was manually added by
 352      the user, and we should not attempt to prune it
 353      automatically.  */
 354   bool removable = false;
 355
 356   /* The address space bound to this inferior.  */
 357   struct address_space *aspace = NULL;
 358
 359   /* The program space bound to this inferior.  */
 360   struct program_space *pspace = NULL;
 361
 362   /* The arguments string to use when running.  */
 363   char *args = NULL;
 364
 365   /* The size of elements in argv.  */
 366   int argc = 0;
 367
 368   /* The vector version of arguments.  If ARGC is nonzero,
 369      then we must compute ARGS from this (via the target).
 370      This is always coming from main's argv and therefore
 371      should never be freed.  */
 372   char **argv = NULL;
 373
 374   /* The current working directory that will be used when starting
 375      this inferior.  */
 376   gdb::unique_xmalloc_ptr<char> cwd;
 377
 378   /* The name of terminal device to use for I/O.  */
 379   char *terminal = NULL;
 380
 381   /* The terminal state as set by the last target_terminal::terminal_*
 382      call.  */
 383   target_terminal_state terminal_state = target_terminal_state::is_ours;
 384
 385   /* Environment to use for running inferior,
 386      in format described in environ.h.  */
 387   gdb_environ environment;
 388
 389   /* True if this child process was attached rather than forked.  */
 390   bool attach_flag = false;
 391
 392   /* If this inferior is a vfork child, then this is the pointer to
 393      its vfork parent, if GDB is still attached to it.  */
 394   inferior *vfork_parent = NULL;
 395
 396   /* If this process is a vfork parent, this is the pointer to the
 397      child.  Since a vfork parent is left frozen by the kernel until
 398      the child execs or exits, a process can only have one vfork child
 399      at a given time.  */
 400   inferior *vfork_child = NULL;
 401
 402   /* True if this inferior should be detached when it's vfork sibling
 403      exits or execs.  */
 404   bool pending_detach = false;
 405
 406   /* True if this inferior is a vfork parent waiting for a vfork child
 407      not under our control to be done with the shared memory region,
 408      either by exiting or execing.  */
 409   bool waiting_for_vfork_done = false;
 410
 411   /* True if we're in the process of detaching from this inferior.  */
 412   bool detaching = false;
 413
 414   /* What is left to do for an execution command after any thread of
 415      this inferior stops.  For continuations associated with a
 416      specific thread, see `struct thread_info'.  */
 417   continuation *continuations = NULL;
 418
 419   /* True if setup_inferior wasn't called for this inferior yet.
 420      Until that is done, we must not access inferior memory or
 421      registers, as we haven't determined the target
 422      architecture/description.  */
 423   bool needs_setup = false;
 424
 425   /* Private data used by the target vector implementation.  */
 426   std::unique_ptr<private_inferior> priv;
 427
 428   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 429      In this case, the EXIT_CODE field is also valid.  */
 430   bool has_exit_code = false;
 431   LONGEST exit_code = 0;
 432
 433   /* Default flags to pass to the symbol reading functions.  These are
 434      used whenever a new objfile is created.  */
 435   symfile_add_flags symfile_flags = 0;
 436
 437   /* Info about an inferior's target description (if it's fetched; the
 438      user supplied description's filename, if any; etc.).  */
 439   target_desc_info *tdesc_info = NULL;
 440
 441   /* The architecture associated with the inferior through the
 442      connection to the target.
 443
 444      The architecture vector provides some information that is really
 445      a property of the inferior, accessed through a particular target:
 446      ptrace operations; the layout of certain RSP packets; the
 447      solib_ops vector; etc.  To differentiate architecture accesses to
 448      per-inferior/target properties from
 449      per-thread/per-frame/per-objfile properties, accesses to
 450      per-inferior/target properties should be made through
 451      this gdbarch.  */
 452   struct gdbarch *gdbarch = NULL;
 453
 454   /* Per inferior data-pointers required by other GDB modules.  */
 455   REGISTRY_FIELDS;
 456 };
 457
 458 /* Keep a registry of per-inferior data-pointers required by other GDB
 459    modules.  */
 460
 461 DECLARE_REGISTRY (inferior);
 462
 463 /* Add an inferior to the inferior list, print a message that a new
 464    inferior is found, and return the pointer to the new inferior.
 465    Caller may use this pointer to initialize the private inferior
 466    data.  */
 467 extern struct inferior *add_inferior (int pid);
 468
 469 /* Same as add_inferior, but don't print new inferior notifications to
 470    the CLI.  */
 471 extern struct inferior *add_inferior_silent (int pid);
 472
 473 extern void delete_inferior (struct inferior *todel);
 474
 475 /* Delete an existing inferior list entry, due to inferior detaching.  */
 476 extern void detach_inferior (inferior *inf);
 477
 478 extern void exit_inferior (inferior *inf);
 479
 480 extern void exit_inferior_silent (inferior *inf);
 481
 482 extern void exit_inferior_num_silent (int num);
 483
 484 extern void inferior_appeared (struct inferior *inf, int pid);
 485
 486 /* Get rid of all inferiors.  */
 487 extern void discard_all_inferiors (void);
 488
 489 /* Search function to lookup an inferior by target 'pid'.  */
 490 extern struct inferior *find_inferior_pid (int pid);
 491
 492 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 493 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 494
 495 /* Search function to lookup an inferior by GDB 'num'.  */
 496 extern struct inferior *find_inferior_id (int num);
 497
 498 /* Find an inferior bound to PSPACE, giving preference to the current
 499    inferior.  */
 500 extern struct inferior *
 501   find_inferior_for_program_space (struct program_space *pspace);
 502
 503 /* Inferior iterator function.
 504
 505    Calls a callback function once for each inferior, so long as the
 506    callback function returns false.  If the callback function returns
 507    true, the iteration will end and the current inferior will be
 508    returned.  This can be useful for implementing a search for a
 509    inferior with arbitrary attributes, or for applying some operation
 510    to every inferior.
 511
 512    It is safe to delete the iterated inferior from the callback.  */
 513 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 514                                                          void *),
 515                                                 void *);
 516
 517 /* Returns true if the inferior list is not empty.  */
 518 extern int have_inferiors (void);
 519
 520 /* Returns the number of live inferiors (real live processes).  */
 521 extern int number_of_live_inferiors (void);
 522
 523 /* Returns true if there are any live inferiors in the inferior list
 524    (not cores, not executables, real live processes).  */
 525 extern int have_live_inferiors (void);
 526
 527 /* Save/restore the current inferior.  */
 528
 529 class scoped_restore_current_inferior
 530 {
 531 public:
 532   scoped_restore_current_inferior ()
 533     : m_saved_inf (current_inferior ())
 534   {}
 535
 536   ~scoped_restore_current_inferior ()
 537   { set_current_inferior (m_saved_inf); }
 538
 539   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 540
 541 private:
 542   inferior *m_saved_inf;
 543 };
 544
 545
 546 /* Traverse all inferiors.  */
 547
 548 #define ALL_INFERIORS(I) \
 549   for ((I) = inferior_list; (I); (I) = (I)->next)
 550
 551 /* Traverse all non-exited inferiors.  */
 552
 553 #define ALL_NON_EXITED_INFERIORS(I) \
 554   ALL_INFERIORS (I)                 \
 555     if ((I)->pid != 0)
 556
 557 extern struct inferior *inferior_list;
 558
 559 /* Prune away automatically added inferiors that aren't required
 560    anymore.  */
 561 extern void prune_inferiors (void);
 562
 563 extern int number_of_inferiors (void);
 564
 565 extern struct inferior *add_inferior_with_spaces (void);
 566
 567 /* Print the current selected inferior.  */
 568 extern void print_selected_inferior (struct ui_out *uiout);
 569
 570 #endif /* !defined (INFERIOR_H) */