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