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) 1986-2017 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 gdb_environ;
  34 struct continuation;
  35 struct inferior;
  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 #include "progspace.h"
  47 #include "registry.h"
  48
  49 #include "symfile-add-flags.h"
  50 #include "common/refcounted-object.h"
  51
  52 #include "common-inferior.h"
  53
  54 struct infcall_suspend_state;
  55 struct infcall_control_state;
  56
  57 extern struct infcall_suspend_state *save_infcall_suspend_state (void);
  58 extern struct infcall_control_state *save_infcall_control_state (void);
  59
  60 extern void restore_infcall_suspend_state (struct infcall_suspend_state *);
  61 extern void restore_infcall_control_state (struct infcall_control_state *);
  62
  63 extern struct cleanup *make_cleanup_restore_infcall_suspend_state
  64                                             (struct infcall_suspend_state *);
  65 extern struct cleanup *make_cleanup_restore_infcall_control_state
  66                                             (struct infcall_control_state *);
  67
  68 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
  69 extern void discard_infcall_control_state (struct infcall_control_state *);
  70
  71 extern struct regcache *
  72   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
  73
  74 /* Save value of inferior_ptid so that it may be restored by
  75    a later call to do_cleanups().  Returns the struct cleanup
  76    pointer needed for later doing the cleanup.  */
  77 extern struct cleanup * save_inferior_ptid (void);
  78
  79 extern void set_sigint_trap (void);
  80
  81 extern void clear_sigint_trap (void);
  82
  83 /* Set/get file name for default use for standard in/out in the inferior.  */
  84
  85 extern void set_inferior_io_terminal (const char *terminal_name);
  86 extern const char *get_inferior_io_terminal (void);
  87
  88 /* Collected pid, tid, etc. of the debugged inferior.  When there's
  89    no inferior, ptid_get_pid (inferior_ptid) will be 0.  */
  90
  91 extern ptid_t inferior_ptid;
  92
  93 extern void generic_mourn_inferior (void);
  94
  95 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
  96                                               struct type *type,
  97                                               const gdb_byte *buf);
  98 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
  99                                          struct type *type, gdb_byte *buf,
 100                                          CORE_ADDR addr);
 101 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
 102                                             struct type *type,
 103                                             const gdb_byte *buf);
 104 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 105                                        struct type *type, gdb_byte *buf,
 106                                        CORE_ADDR addr);
 107
 108 extern void reopen_exec_file (void);
 109
 110 /* From misc files */
 111
 112 extern void default_print_registers_info (struct gdbarch *gdbarch,
 113                                           struct ui_file *file,
 114                                           struct frame_info *frame,
 115                                           int regnum, int all);
 116
 117 /* Default implementation of gdbarch_print_float_info.  Print
 118    the values of all floating point registers.  */
 119
 120 extern void default_print_float_info (struct gdbarch *gdbarch,
 121                                       struct ui_file *file,
 122                                       struct frame_info *frame,
 123                                       const char *args);
 124
 125 extern void child_terminal_info (struct target_ops *self, const char *, int);
 126
 127 extern void term_info (char *, int);
 128
 129 extern void child_terminal_ours (struct target_ops *self);
 130
 131 extern void child_terminal_ours_for_output (struct target_ops *self);
 132
 133 extern void child_terminal_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 /* From fork-child.c */
 140
 141 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 142    This function already calls set_executing.  Return the ptid_t from
 143    STARTUP_INFERIOR.  */
 144 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 145
 146 extern char *construct_inferior_arguments (int, char **);
 147
 148 /* From infcmd.c */
 149
 150 /* Initial inferior setup.  Determines the exec file is not yet known,
 151    takes any necessary post-attaching actions, fetches the target
 152    description and syncs the shared library list.  */
 153
 154 extern void setup_inferior (int from_tty);
 155
 156 extern void post_create_inferior (struct target_ops *, int);
 157
 158 extern void attach_command (char *, int);
 159
 160 extern char *get_inferior_args (void);
 161
 162 extern void set_inferior_args (char *);
 163
 164 extern void set_inferior_args_vector (int, char **);
 165
 166 extern void registers_info (char *, int);
 167
 168 extern void continue_1 (int all_threads);
 169
 170 extern void interrupt_target_1 (int all_threads);
 171
 172 extern void delete_longjmp_breakpoint_cleanup (void *arg);
 173
 174 extern void detach_command (char *, int);
 175
 176 extern void notice_new_inferior (ptid_t, int, int);
 177
 178 extern struct value *get_return_value (struct value *function,
 179                                        struct type *value_type);
 180
 181 /* Prepare for execution command.  TARGET is the target that will run
 182    the command.  BACKGROUND determines whether this is a foreground
 183    (synchronous) or background (asynchronous) command.  */
 184
 185 extern void prepare_execution_command (struct target_ops *target,
 186                                        int background);
 187
 188 /* Whether to start up the debuggee under a shell.
 189
 190    If startup-with-shell is set, GDB's "run" will attempt to start up
 191    the debuggee under a shell.
 192
 193    This is in order for argument-expansion to occur.  E.g.,
 194
 195    (gdb) run *
 196
 197    The "*" gets expanded by the shell into a list of files.
 198
 199    While this is a nice feature, it may be handy to bypass the shell
 200    in some cases.  To disable this feature, do "set startup-with-shell
 201    false".
 202
 203    The catch-exec traps expected during start-up will be one more if
 204    the target is started up with a shell.  */
 205 extern int startup_with_shell;
 206
 207 /* Address at which inferior stopped.  */
 208
 209 extern CORE_ADDR stop_pc;
 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 /* STEP_OVER_ALL means step over all subroutine calls.
 221    STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
 222    STEP_OVER_NONE means don't step over any subroutine calls.  */
 223
 224 enum step_over_calls_kind
 225   {
 226     STEP_OVER_NONE,
 227     STEP_OVER_ALL,
 228     STEP_OVER_UNDEBUGGABLE
 229   };
 230
 231 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 232    will handle it themselves.  STOP_QUIETLY is used when running in
 233    the shell before the child program has been exec'd and when running
 234    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 235    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 236    except that there is no need to hide a signal.  */
 237
 238 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 239    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 240    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 241    a ptraced process has changed.  Earlier versions of the kernel
 242    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 243    other signal, i.e. it is not muffled.
 244
 245    If the gdb user does a 'continue' after the 'attach', gdb passes
 246    the global variable stop_signal (which stores the signal from the
 247    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 248    problematic, because the kernel doesn't ignore such SIGSTOP
 249    now.  I.e. it is reported back to gdb, which in turn presents it
 250    back to the user.
 251
 252    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 253    gdb to clear the value of stop_signal after the attach, so that it
 254    is not passed back down to the kernel.  */
 255
 256 enum stop_kind
 257   {
 258     NO_STOP_QUIETLY = 0,
 259     STOP_QUIETLY,
 260     STOP_QUIETLY_REMOTE,
 261     STOP_QUIETLY_NO_SIGSTOP
 262   };
 263
 264 \f
 265 /* Possible values for gdbarch_call_dummy_location.  */
 266 #define ON_STACK 1
 267 #define AT_ENTRY_POINT 4
 268
 269 struct private_inferior;
 270
 271 /* Inferior process specific part of `struct infcall_control_state'.
 272
 273    Inferior thread counterpart is `struct thread_control_state'.  */
 274
 275 struct inferior_control_state
 276 {
 277   /* See the definition of stop_kind above.  */
 278   enum stop_kind stop_soon;
 279 };
 280
 281 /* Return a pointer to the current inferior.  */
 282 extern inferior *current_inferior ();
 283
 284 extern void set_current_inferior (inferior *);
 285
 286 /* GDB represents the state of each program execution with an object
 287    called an inferior.  An inferior typically corresponds to a process
 288    but is more general and applies also to targets that do not have a
 289    notion of processes.  Each run of an executable creates a new
 290    inferior, as does each attachment to an existing process.
 291    Inferiors have unique internal identifiers that are different from
 292    target process ids.  Each inferior may in turn have multiple
 293    threads running in it.
 294
 295    Inferiors are intrusively refcounted objects.  Unlike thread
 296    objects, being the user-selected inferior is considered a strong
 297    reference and is thus accounted for in the inferior object's
 298    refcount (see set_current_inferior).  When GDB needs to remember
 299    the selected inferior to later restore it, GDB temporarily bumps
 300    the inferior object's refcount, to prevent something deleting the
 301    inferior object before reverting back (e.g., due to a
 302    "remove-inferiors" command (see
 303    make_cleanup_restore_current_thread).  All other inferior
 304    references are considered weak references.  Inferiors are always
 305    listed exactly once in the inferior list, so placing an inferior in
 306    the inferior list is an implicit, not counted strong reference.  */
 307
 308 class inferior : public refcounted_object
 309 {
 310 public:
 311   explicit inferior (int pid);
 312   ~inferior ();
 313
 314   /* Returns true if we can delete this inferior.  */
 315   bool deletable () const { return refcount () == 0; }
 316
 317   /* Pointer to next inferior in singly-linked list of inferiors.  */
 318   struct inferior *next = NULL;
 319
 320   /* Convenient handle (GDB inferior id).  Unique across all
 321      inferiors.  */
 322   int num = 0;
 323
 324   /* Actual target inferior id, usually, a process id.  This matches
 325      the ptid_t.pid member of threads of this inferior.  */
 326   int pid = 0;
 327   /* True if the PID was actually faked by GDB.  */
 328   bool fake_pid_p = false;
 329
 330   /* The highest thread number this inferior ever had.  */
 331   int highest_thread_num = 0;
 332
 333   /* State of GDB control of inferior process execution.
 334      See `struct inferior_control_state'.  */
 335   inferior_control_state control {NO_STOP_QUIETLY};
 336
 337   /* True if this was an auto-created inferior, e.g. created from
 338      following a fork; false, if this inferior was manually added by
 339      the user, and we should not attempt to prune it
 340      automatically.  */
 341   bool removable = false;
 342
 343   /* The address space bound to this inferior.  */
 344   struct address_space *aspace = NULL;
 345
 346   /* The program space bound to this inferior.  */
 347   struct program_space *pspace = NULL;
 348
 349   /* The arguments string to use when running.  */
 350   char *args = NULL;
 351
 352   /* The size of elements in argv.  */
 353   int argc = 0;
 354
 355   /* The vector version of arguments.  If ARGC is nonzero,
 356      then we must compute ARGS from this (via the target).
 357      This is always coming from main's argv and therefore
 358      should never be freed.  */
 359   char **argv = NULL;
 360
 361   /* The name of terminal device to use for I/O.  */
 362   char *terminal = NULL;
 363
 364   /* Environment to use for running inferior,
 365      in format described in environ.h.  */
 366   gdb_environ *environment = NULL;
 367
 368   /* True if this child process was attached rather than forked.  */
 369   bool attach_flag = false;
 370
 371   /* If this inferior is a vfork child, then this is the pointer to
 372      its vfork parent, if GDB is still attached to it.  */
 373   inferior *vfork_parent = NULL;
 374
 375   /* If this process is a vfork parent, this is the pointer to the
 376      child.  Since a vfork parent is left frozen by the kernel until
 377      the child execs or exits, a process can only have one vfork child
 378      at a given time.  */
 379   inferior *vfork_child = NULL;
 380
 381   /* True if this inferior should be detached when it's vfork sibling
 382      exits or execs.  */
 383   bool pending_detach = false;
 384
 385   /* True if this inferior is a vfork parent waiting for a vfork child
 386      not under our control to be done with the shared memory region,
 387      either by exiting or execing.  */
 388   bool waiting_for_vfork_done = false;
 389
 390   /* True if we're in the process of detaching from this inferior.  */
 391   bool detaching = false;
 392
 393   /* What is left to do for an execution command after any thread of
 394      this inferior stops.  For continuations associated with a
 395      specific thread, see `struct thread_info'.  */
 396   continuation *continuations = NULL;
 397
 398   /* True if setup_inferior wasn't called for this inferior yet.
 399      Until that is done, we must not access inferior memory or
 400      registers, as we haven't determined the target
 401      architecture/description.  */
 402   bool needs_setup = false;
 403
 404   /* Private data used by the target vector implementation.  */
 405   private_inferior *priv = NULL;
 406
 407   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 408      In this case, the EXIT_CODE field is also valid.  */
 409   bool has_exit_code = false;
 410   LONGEST exit_code = 0;
 411
 412   /* Default flags to pass to the symbol reading functions.  These are
 413      used whenever a new objfile is created.  */
 414   symfile_add_flags symfile_flags = 0;
 415
 416   /* Info about an inferior's target description (if it's fetched; the
 417      user supplied description's filename, if any; etc.).  */
 418   target_desc_info *tdesc_info = NULL;
 419
 420   /* The architecture associated with the inferior through the
 421      connection to the target.
 422
 423      The architecture vector provides some information that is really
 424      a property of the inferior, accessed through a particular target:
 425      ptrace operations; the layout of certain RSP packets; the
 426      solib_ops vector; etc.  To differentiate architecture accesses to
 427      per-inferior/target properties from
 428      per-thread/per-frame/per-objfile properties, accesses to
 429      per-inferior/target properties should be made through
 430      this gdbarch.  */
 431   struct gdbarch *gdbarch = NULL;
 432
 433   /* Per inferior data-pointers required by other GDB modules.  */
 434   REGISTRY_FIELDS;
 435 };
 436
 437 /* Keep a registry of per-inferior data-pointers required by other GDB
 438    modules.  */
 439
 440 DECLARE_REGISTRY (inferior);
 441
 442 /* Add an inferior to the inferior list, print a message that a new
 443    inferior is found, and return the pointer to the new inferior.
 444    Caller may use this pointer to initialize the private inferior
 445    data.  */
 446 extern struct inferior *add_inferior (int pid);
 447
 448 /* Same as add_inferior, but don't print new inferior notifications to
 449    the CLI.  */
 450 extern struct inferior *add_inferior_silent (int pid);
 451
 452 extern void delete_inferior (struct inferior *todel);
 453
 454 /* Delete an existing inferior list entry, due to inferior detaching.  */
 455 extern void detach_inferior (int pid);
 456
 457 extern void exit_inferior (int pid);
 458
 459 extern void exit_inferior_silent (int pid);
 460
 461 extern void exit_inferior_num_silent (int num);
 462
 463 extern void inferior_appeared (struct inferior *inf, int pid);
 464
 465 /* Get rid of all inferiors.  */
 466 extern void discard_all_inferiors (void);
 467
 468 /* Translate the integer inferior id (GDB's homegrown id, not the system's)
 469    into a "pid" (which may be overloaded with extra inferior information).  */
 470 extern int gdb_inferior_id_to_pid (int);
 471
 472 /* Translate a target 'pid' into the integer inferior id (GDB's
 473    homegrown id, not the system's).  */
 474 extern int pid_to_gdb_inferior_id (int pid);
 475
 476 /* Boolean test for an already-known pid.  */
 477 extern int in_inferior_list (int pid);
 478
 479 /* Boolean test for an already-known inferior id (GDB's homegrown id,
 480    not the system's).  */
 481 extern int valid_gdb_inferior_id (int num);
 482
 483 /* Search function to lookup an inferior by target 'pid'.  */
 484 extern struct inferior *find_inferior_pid (int pid);
 485
 486 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 487 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 488
 489 /* Search function to lookup an inferior by GDB 'num'.  */
 490 extern struct inferior *find_inferior_id (int num);
 491
 492 /* Find an inferior bound to PSPACE, giving preference to the current
 493    inferior.  */
 494 extern struct inferior *
 495   find_inferior_for_program_space (struct program_space *pspace);
 496
 497 /* Inferior iterator function.
 498
 499    Calls a callback function once for each inferior, so long as the
 500    callback function returns false.  If the callback function returns
 501    true, the iteration will end and the current inferior will be
 502    returned.  This can be useful for implementing a search for a
 503    inferior with arbitrary attributes, or for applying some operation
 504    to every inferior.
 505
 506    It is safe to delete the iterated inferior from the callback.  */
 507 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 508                                                          void *),
 509                                                 void *);
 510
 511 /* Returns true if the inferior list is not empty.  */
 512 extern int have_inferiors (void);
 513
 514 /* Returns the number of live inferiors (real live processes).  */
 515 extern int number_of_live_inferiors (void);
 516
 517 /* Returns true if there are any live inferiors in the inferior list
 518    (not cores, not executables, real live processes).  */
 519 extern int have_live_inferiors (void);
 520
 521 /* Save/restore the current inferior.  */
 522
 523 class scoped_restore_current_inferior
 524 {
 525 public:
 526   scoped_restore_current_inferior ()
 527     : m_saved_inf (current_inferior ())
 528   {}
 529
 530   ~scoped_restore_current_inferior ()
 531   { set_current_inferior (m_saved_inf); }
 532
 533   /* Disable copy.  */
 534   scoped_restore_current_inferior
 535     (const scoped_restore_current_inferior &) = delete;
 536   void operator=
 537     (const scoped_restore_current_inferior &) = delete;
 538
 539 private:
 540   inferior *m_saved_inf;
 541 };
 542
 543
 544 /* Traverse all inferiors.  */
 545
 546 #define ALL_INFERIORS(I) \
 547   for ((I) = inferior_list; (I); (I) = (I)->next)
 548
 549 /* Traverse all non-exited inferiors.  */
 550
 551 #define ALL_NON_EXITED_INFERIORS(I) \
 552   ALL_INFERIORS (I)                 \
 553     if ((I)->pid != 0)
 554
 555 extern struct inferior *inferior_list;
 556
 557 /* Prune away automatically added inferiors that aren't required
 558    anymore.  */
 559 extern void prune_inferiors (void);
 560
 561 extern int number_of_inferiors (void);
 562
 563 extern struct inferior *add_inferior_with_spaces (void);
 564
 565 /* Print the current selected inferior.  */
 566 extern void print_selected_inferior (struct ui_out *uiout);
 567
 568 #endif /* !defined (INFERIOR_H) */