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
  36 /* For bpstat.  */
  37 #include "breakpoint.h"
  38
  39 /* For enum gdb_signal.  */
  40 #include "target.h"
  41
  42 /* For struct frame_id.  */
  43 #include "frame.h"
  44
  45 /* For gdb_environ.  */
  46 #include "environ.h"
  47
  48 #include "progspace.h"
  49 #include "registry.h"
  50
  51 #include "symfile-add-flags.h"
  52 #include "common/refcounted-object.h"
  53
  54 #include "common-inferior.h"
  55
  56 struct infcall_suspend_state;
  57 struct infcall_control_state;
  58
  59 extern struct infcall_suspend_state *save_infcall_suspend_state (void);
  60 extern struct infcall_control_state *save_infcall_control_state (void);
  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 extern struct cleanup *make_cleanup_restore_infcall_suspend_state
  66                                             (struct infcall_suspend_state *);
  67 extern struct cleanup *make_cleanup_restore_infcall_control_state
  68                                             (struct infcall_control_state *);
  69
  70 extern void discard_infcall_suspend_state (struct infcall_suspend_state *);
  71 extern void discard_infcall_control_state (struct infcall_control_state *);
  72
  73 extern readonly_detached_regcache *
  74   get_infcall_suspend_state_regcache (struct infcall_suspend_state *);
  75
  76 extern void set_sigint_trap (void);
  77
  78 extern void clear_sigint_trap (void);
  79
  80 /* Set/get file name for default use for standard in/out in the inferior.  */
  81
  82 extern void set_inferior_io_terminal (const char *terminal_name);
  83 extern const char *get_inferior_io_terminal (void);
  84
  85 /* Collected pid, tid, etc. of the debugged inferior.  When there's
  86    no inferior, ptid_get_pid (inferior_ptid) will be 0.  */
  87
  88 extern ptid_t inferior_ptid;
  89
  90 extern void generic_mourn_inferior (void);
  91
  92 extern CORE_ADDR unsigned_pointer_to_address (struct gdbarch *gdbarch,
  93                                               struct type *type,
  94                                               const gdb_byte *buf);
  95 extern void unsigned_address_to_pointer (struct gdbarch *gdbarch,
  96                                          struct type *type, gdb_byte *buf,
  97                                          CORE_ADDR addr);
  98 extern CORE_ADDR signed_pointer_to_address (struct gdbarch *gdbarch,
  99                                             struct type *type,
 100                                             const gdb_byte *buf);
 101 extern void address_to_signed_pointer (struct gdbarch *gdbarch,
 102                                        struct type *type, gdb_byte *buf,
 103                                        CORE_ADDR addr);
 104
 105 extern void reopen_exec_file (void);
 106
 107 /* From misc files */
 108
 109 extern void default_print_registers_info (struct gdbarch *gdbarch,
 110                                           struct ui_file *file,
 111                                           struct frame_info *frame,
 112                                           int regnum, int all);
 113
 114 /* Default implementation of gdbarch_print_float_info.  Print
 115    the values of all floating point registers.  */
 116
 117 extern void default_print_float_info (struct gdbarch *gdbarch,
 118                                       struct ui_file *file,
 119                                       struct frame_info *frame,
 120                                       const char *args);
 121
 122 extern void child_terminal_info (struct target_ops *self, const char *, int);
 123
 124 extern void info_terminal_command (char *, int);
 125
 126 extern void child_terminal_ours (struct target_ops *self);
 127
 128 extern void child_terminal_ours_for_output (struct target_ops *self);
 129
 130 extern void child_terminal_inferior (struct target_ops *self);
 131
 132 extern void child_terminal_save_inferior (struct target_ops *self);
 133
 134 extern void child_terminal_init (struct target_ops *self);
 135
 136 extern void child_terminal_init_with_pgrp (int pgrp);
 137
 138 extern void child_pass_ctrlc (struct target_ops *self);
 139
 140 extern void child_interrupt (struct target_ops *self);
 141
 142 /* From fork-child.c */
 143
 144 /* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
 145    This function already calls set_executing.  Return the ptid_t from
 146    STARTUP_INFERIOR.  */
 147 extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 148
 149 extern char *construct_inferior_arguments (int, char **);
 150
 151 /* From infcmd.c */
 152
 153 /* Initial inferior setup.  Determines the exec file is not yet known,
 154    takes any necessary post-attaching actions, fetches the target
 155    description and syncs the shared library list.  */
 156
 157 extern void setup_inferior (int from_tty);
 158
 159 extern void post_create_inferior (struct target_ops *, int);
 160
 161 extern void attach_command (const char *, int);
 162
 163 extern char *get_inferior_args (void);
 164
 165 extern void set_inferior_args (const char *);
 166
 167 extern void set_inferior_args_vector (int, char **);
 168
 169 extern void registers_info (const char *, int);
 170
 171 extern void continue_1 (int all_threads);
 172
 173 extern void interrupt_target_1 (int all_threads);
 174
 175 extern void delete_longjmp_breakpoint_cleanup (void *arg);
 176
 177 extern void detach_command (const char *, int);
 178
 179 extern void notice_new_inferior (ptid_t, int, int);
 180
 181 extern struct value *get_return_value (struct value *function,
 182                                        struct type *value_type);
 183
 184 /* Prepare for execution command.  TARGET is the target that will run
 185    the command.  BACKGROUND determines whether this is a foreground
 186    (synchronous) or background (asynchronous) command.  */
 187
 188 extern void prepare_execution_command (struct target_ops *target,
 189                                        int background);
 190
 191 /* Whether to start up the debuggee under a shell.
 192
 193    If startup-with-shell is set, GDB's "run" will attempt to start up
 194    the debuggee under a shell.
 195
 196    This is in order for argument-expansion to occur.  E.g.,
 197
 198    (gdb) run *
 199
 200    The "*" gets expanded by the shell into a list of files.
 201
 202    While this is a nice feature, it may be handy to bypass the shell
 203    in some cases.  To disable this feature, do "set startup-with-shell
 204    false".
 205
 206    The catch-exec traps expected during start-up will be one more if
 207    the target is started up with a shell.  */
 208 extern int startup_with_shell;
 209
 210 /* Address at which inferior stopped.  */
 211
 212 extern CORE_ADDR stop_pc;
 213
 214 /* Nonzero if stopped due to completion of a stack dummy routine.  */
 215
 216 extern enum stop_stack_kind stop_stack_dummy;
 217
 218 /* Nonzero if program stopped due to a random (unexpected) signal in
 219    inferior process.  */
 220
 221 extern int stopped_by_random_signal;
 222
 223 /* STEP_OVER_ALL means step over all subroutine calls.
 224    STEP_OVER_UNDEBUGGABLE means step over calls to undebuggable functions.
 225    STEP_OVER_NONE means don't step over any subroutine calls.  */
 226
 227 enum step_over_calls_kind
 228   {
 229     STEP_OVER_NONE,
 230     STEP_OVER_ALL,
 231     STEP_OVER_UNDEBUGGABLE
 232   };
 233
 234 /* Anything but NO_STOP_QUIETLY means we expect a trap and the caller
 235    will handle it themselves.  STOP_QUIETLY is used when running in
 236    the shell before the child program has been exec'd and when running
 237    through shared library loading.  STOP_QUIETLY_REMOTE is used when
 238    setting up a remote connection; it is like STOP_QUIETLY_NO_SIGSTOP
 239    except that there is no need to hide a signal.  */
 240
 241 /* STOP_QUIETLY_NO_SIGSTOP is used to handle a tricky situation with attach.
 242    When doing an attach, the kernel stops the debuggee with a SIGSTOP.
 243    On newer GNU/Linux kernels (>= 2.5.61) the handling of SIGSTOP for
 244    a ptraced process has changed.  Earlier versions of the kernel
 245    would ignore these SIGSTOPs, while now SIGSTOP is treated like any
 246    other signal, i.e. it is not muffled.
 247
 248    If the gdb user does a 'continue' after the 'attach', gdb passes
 249    the global variable stop_signal (which stores the signal from the
 250    attach, SIGSTOP) to the ptrace(PTRACE_CONT,...)  call.  This is
 251    problematic, because the kernel doesn't ignore such SIGSTOP
 252    now.  I.e. it is reported back to gdb, which in turn presents it
 253    back to the user.
 254
 255    To avoid the problem, we use STOP_QUIETLY_NO_SIGSTOP, which allows
 256    gdb to clear the value of stop_signal after the attach, so that it
 257    is not passed back down to the kernel.  */
 258
 259 enum stop_kind
 260   {
 261     NO_STOP_QUIETLY = 0,
 262     STOP_QUIETLY,
 263     STOP_QUIETLY_REMOTE,
 264     STOP_QUIETLY_NO_SIGSTOP
 265   };
 266
 267 \f
 268 /* Possible values for gdbarch_call_dummy_location.  */
 269 #define ON_STACK 1
 270 #define AT_ENTRY_POINT 4
 271
 272 /* Base class for target-specific inferior data.  */
 273
 274 struct private_inferior
 275 {
 276   virtual ~private_inferior () = 0;
 277 };
 278
 279 /* Inferior process specific part of `struct infcall_control_state'.
 280
 281    Inferior thread counterpart is `struct thread_control_state'.  */
 282
 283 struct inferior_control_state
 284 {
 285   /* See the definition of stop_kind above.  */
 286   enum stop_kind stop_soon;
 287 };
 288
 289 /* Return a pointer to the current inferior.  */
 290 extern inferior *current_inferior ();
 291
 292 extern void set_current_inferior (inferior *);
 293
 294 /* GDB represents the state of each program execution with an object
 295    called an inferior.  An inferior typically corresponds to a process
 296    but is more general and applies also to targets that do not have a
 297    notion of processes.  Each run of an executable creates a new
 298    inferior, as does each attachment to an existing process.
 299    Inferiors have unique internal identifiers that are different from
 300    target process ids.  Each inferior may in turn have multiple
 301    threads running in it.
 302
 303    Inferiors are intrusively refcounted objects.  Unlike thread
 304    objects, being the user-selected inferior is considered a strong
 305    reference and is thus accounted for in the inferior object's
 306    refcount (see set_current_inferior).  When GDB needs to remember
 307    the selected inferior to later restore it, GDB temporarily bumps
 308    the inferior object's refcount, to prevent something deleting the
 309    inferior object before reverting back (e.g., due to a
 310    "remove-inferiors" command (see
 311    make_cleanup_restore_current_thread).  All other inferior
 312    references are considered weak references.  Inferiors are always
 313    listed exactly once in the inferior list, so placing an inferior in
 314    the inferior list is an implicit, not counted strong reference.  */
 315
 316 class inferior : public refcounted_object
 317 {
 318 public:
 319   explicit inferior (int pid);
 320   ~inferior ();
 321
 322   /* Returns true if we can delete this inferior.  */
 323   bool deletable () const { return refcount () == 0; }
 324
 325   /* Pointer to next inferior in singly-linked list of inferiors.  */
 326   struct inferior *next = NULL;
 327
 328   /* Convenient handle (GDB inferior id).  Unique across all
 329      inferiors.  */
 330   int num = 0;
 331
 332   /* Actual target inferior id, usually, a process id.  This matches
 333      the ptid_t.pid member of threads of this inferior.  */
 334   int pid = 0;
 335   /* True if the PID was actually faked by GDB.  */
 336   bool fake_pid_p = false;
 337
 338   /* The highest thread number this inferior ever had.  */
 339   int highest_thread_num = 0;
 340
 341   /* State of GDB control of inferior process execution.
 342      See `struct inferior_control_state'.  */
 343   inferior_control_state control {NO_STOP_QUIETLY};
 344
 345   /* True if this was an auto-created inferior, e.g. created from
 346      following a fork; false, if this inferior was manually added by
 347      the user, and we should not attempt to prune it
 348      automatically.  */
 349   bool removable = false;
 350
 351   /* The address space bound to this inferior.  */
 352   struct address_space *aspace = NULL;
 353
 354   /* The program space bound to this inferior.  */
 355   struct program_space *pspace = NULL;
 356
 357   /* The arguments string to use when running.  */
 358   char *args = NULL;
 359
 360   /* The size of elements in argv.  */
 361   int argc = 0;
 362
 363   /* The vector version of arguments.  If ARGC is nonzero,
 364      then we must compute ARGS from this (via the target).
 365      This is always coming from main's argv and therefore
 366      should never be freed.  */
 367   char **argv = NULL;
 368
 369   /* The current working directory that will be used when starting
 370      this inferior.  */
 371   gdb::unique_xmalloc_ptr<char> cwd;
 372
 373   /* The name of terminal device to use for I/O.  */
 374   char *terminal = NULL;
 375
 376   /* The terminal state as set by the last target_terminal::terminal_*
 377      call.  */
 378   target_terminal_state terminal_state = target_terminal_state::is_ours;
 379
 380   /* Environment to use for running inferior,
 381      in format described in environ.h.  */
 382   gdb_environ environment;
 383
 384   /* True if this child process was attached rather than forked.  */
 385   bool attach_flag = false;
 386
 387   /* If this inferior is a vfork child, then this is the pointer to
 388      its vfork parent, if GDB is still attached to it.  */
 389   inferior *vfork_parent = NULL;
 390
 391   /* If this process is a vfork parent, this is the pointer to the
 392      child.  Since a vfork parent is left frozen by the kernel until
 393      the child execs or exits, a process can only have one vfork child
 394      at a given time.  */
 395   inferior *vfork_child = NULL;
 396
 397   /* True if this inferior should be detached when it's vfork sibling
 398      exits or execs.  */
 399   bool pending_detach = false;
 400
 401   /* True if this inferior is a vfork parent waiting for a vfork child
 402      not under our control to be done with the shared memory region,
 403      either by exiting or execing.  */
 404   bool waiting_for_vfork_done = false;
 405
 406   /* True if we're in the process of detaching from this inferior.  */
 407   bool detaching = false;
 408
 409   /* What is left to do for an execution command after any thread of
 410      this inferior stops.  For continuations associated with a
 411      specific thread, see `struct thread_info'.  */
 412   continuation *continuations = NULL;
 413
 414   /* True if setup_inferior wasn't called for this inferior yet.
 415      Until that is done, we must not access inferior memory or
 416      registers, as we haven't determined the target
 417      architecture/description.  */
 418   bool needs_setup = false;
 419
 420   /* Private data used by the target vector implementation.  */
 421   std::unique_ptr<private_inferior> priv;
 422
 423   /* HAS_EXIT_CODE is true if the inferior exited with an exit code.
 424      In this case, the EXIT_CODE field is also valid.  */
 425   bool has_exit_code = false;
 426   LONGEST exit_code = 0;
 427
 428   /* Default flags to pass to the symbol reading functions.  These are
 429      used whenever a new objfile is created.  */
 430   symfile_add_flags symfile_flags = 0;
 431
 432   /* Info about an inferior's target description (if it's fetched; the
 433      user supplied description's filename, if any; etc.).  */
 434   target_desc_info *tdesc_info = NULL;
 435
 436   /* The architecture associated with the inferior through the
 437      connection to the target.
 438
 439      The architecture vector provides some information that is really
 440      a property of the inferior, accessed through a particular target:
 441      ptrace operations; the layout of certain RSP packets; the
 442      solib_ops vector; etc.  To differentiate architecture accesses to
 443      per-inferior/target properties from
 444      per-thread/per-frame/per-objfile properties, accesses to
 445      per-inferior/target properties should be made through
 446      this gdbarch.  */
 447   struct gdbarch *gdbarch = NULL;
 448
 449   /* Per inferior data-pointers required by other GDB modules.  */
 450   REGISTRY_FIELDS;
 451 };
 452
 453 /* Keep a registry of per-inferior data-pointers required by other GDB
 454    modules.  */
 455
 456 DECLARE_REGISTRY (inferior);
 457
 458 /* Add an inferior to the inferior list, print a message that a new
 459    inferior is found, and return the pointer to the new inferior.
 460    Caller may use this pointer to initialize the private inferior
 461    data.  */
 462 extern struct inferior *add_inferior (int pid);
 463
 464 /* Same as add_inferior, but don't print new inferior notifications to
 465    the CLI.  */
 466 extern struct inferior *add_inferior_silent (int pid);
 467
 468 extern void delete_inferior (struct inferior *todel);
 469
 470 /* Delete an existing inferior list entry, due to inferior detaching.  */
 471 extern void detach_inferior (inferior *inf);
 472
 473 /* Same as the above, but with the inferior specified by PID.  */
 474 extern void detach_inferior (int pid);
 475
 476 extern void exit_inferior (int pid);
 477
 478 extern void exit_inferior_silent (int pid);
 479
 480 extern void exit_inferior_num_silent (int num);
 481
 482 extern void inferior_appeared (struct inferior *inf, int pid);
 483
 484 /* Get rid of all inferiors.  */
 485 extern void discard_all_inferiors (void);
 486
 487 /* Translate the integer inferior id (GDB's homegrown id, not the system's)
 488    into a "pid" (which may be overloaded with extra inferior information).  */
 489 extern int gdb_inferior_id_to_pid (int);
 490
 491 /* Translate a target 'pid' into the integer inferior id (GDB's
 492    homegrown id, not the system's).  */
 493 extern int pid_to_gdb_inferior_id (int pid);
 494
 495 /* Boolean test for an already-known pid.  */
 496 extern int in_inferior_list (int pid);
 497
 498 /* Boolean test for an already-known inferior id (GDB's homegrown id,
 499    not the system's).  */
 500 extern int valid_gdb_inferior_id (int num);
 501
 502 /* Search function to lookup an inferior by target 'pid'.  */
 503 extern struct inferior *find_inferior_pid (int pid);
 504
 505 /* Search function to lookup an inferior whose pid is equal to 'ptid.pid'. */
 506 extern struct inferior *find_inferior_ptid (ptid_t ptid);
 507
 508 /* Search function to lookup an inferior by GDB 'num'.  */
 509 extern struct inferior *find_inferior_id (int num);
 510
 511 /* Find an inferior bound to PSPACE, giving preference to the current
 512    inferior.  */
 513 extern struct inferior *
 514   find_inferior_for_program_space (struct program_space *pspace);
 515
 516 /* Inferior iterator function.
 517
 518    Calls a callback function once for each inferior, so long as the
 519    callback function returns false.  If the callback function returns
 520    true, the iteration will end and the current inferior will be
 521    returned.  This can be useful for implementing a search for a
 522    inferior with arbitrary attributes, or for applying some operation
 523    to every inferior.
 524
 525    It is safe to delete the iterated inferior from the callback.  */
 526 extern struct inferior *iterate_over_inferiors (int (*) (struct inferior *,
 527                                                          void *),
 528                                                 void *);
 529
 530 /* Returns true if the inferior list is not empty.  */
 531 extern int have_inferiors (void);
 532
 533 /* Returns the number of live inferiors (real live processes).  */
 534 extern int number_of_live_inferiors (void);
 535
 536 /* Returns true if there are any live inferiors in the inferior list
 537    (not cores, not executables, real live processes).  */
 538 extern int have_live_inferiors (void);
 539
 540 /* Save/restore the current inferior.  */
 541
 542 class scoped_restore_current_inferior
 543 {
 544 public:
 545   scoped_restore_current_inferior ()
 546     : m_saved_inf (current_inferior ())
 547   {}
 548
 549   ~scoped_restore_current_inferior ()
 550   { set_current_inferior (m_saved_inf); }
 551
 552   DISABLE_COPY_AND_ASSIGN (scoped_restore_current_inferior);
 553
 554 private:
 555   inferior *m_saved_inf;
 556 };
 557
 558
 559 /* Traverse all inferiors.  */
 560
 561 #define ALL_INFERIORS(I) \
 562   for ((I) = inferior_list; (I); (I) = (I)->next)
 563
 564 /* Traverse all non-exited inferiors.  */
 565
 566 #define ALL_NON_EXITED_INFERIORS(I) \
 567   ALL_INFERIORS (I)                 \
 568     if ((I)->pid != 0)
 569
 570 extern struct inferior *inferior_list;
 571
 572 /* Prune away automatically added inferiors that aren't required
 573    anymore.  */
 574 extern void prune_inferiors (void);
 575
 576 extern int number_of_inferiors (void);
 577
 578 extern struct inferior *add_inferior_with_spaces (void);
 579
 580 /* Print the current selected inferior.  */
 581 extern void print_selected_inferior (struct ui_out *uiout);
 582
 583 #endif /* !defined (INFERIOR_H) */