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