gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2    Copyright 1990, 91, 92, 93, 94, 1999 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.  Written by John Gilmore.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #if !defined (TARGET_H)
  22 #define TARGET_H
  23
  24 /* This include file defines the interface between the main part
  25    of the debugger, and the part which is target-specific, or
  26    specific to the communications interface between us and the
  27    target.
  28
  29    A TARGET is an interface between the debugger and a particular
  30    kind of file or process.  Targets can be STACKED in STRATA,
  31    so that more than one target can potentially respond to a request.
  32    In particular, memory accesses will walk down the stack of targets
  33    until they find a target that is interested in handling that particular
  34    address.  STRATA are artificial boundaries on the stack, within
  35    which particular kinds of targets live.  Strata exist so that
  36    people don't get confused by pushing e.g. a process target and then
  37    a file target, and wondering why they can't see the current values
  38    of variables any more (the file target is handling them and they
  39    never get to the process target).  So when you push a file target,
  40    it goes into the file stratum, which is always below the process
  41    stratum.  */
  42
  43 #include "bfd.h"
  44 #include "symtab.h"
  45
  46 enum strata {
  47         dummy_stratum,          /* The lowest of the low */
  48         file_stratum,           /* Executable files, etc */
  49         core_stratum,           /* Core dump files */
  50         download_stratum,       /* Downloading of remote targets */
  51         process_stratum         /* Executing processes */
  52 };
  53
  54 enum thread_control_capabilities {
  55         tc_none = 0,            /* Default: can't control thread execution. */
  56         tc_schedlock = 1,       /* Can lock the thread scheduler. */
  57         tc_switch = 2           /* Can switch the running thread on demand. */
  58 };
  59
  60 /* Stuff for target_wait.  */
  61
  62 /* Generally, what has the program done?  */
  63 enum target_waitkind {
  64   /* The program has exited.  The exit status is in value.integer.  */
  65   TARGET_WAITKIND_EXITED,
  66
  67   /* The program has stopped with a signal.  Which signal is in value.sig.  */
  68   TARGET_WAITKIND_STOPPED,
  69
  70   /* The program has terminated with a signal.  Which signal is in
  71      value.sig.  */
  72   TARGET_WAITKIND_SIGNALLED,
  73
  74   /* The program is letting us know that it dynamically loaded something
  75      (e.g. it called load(2) on AIX).  */
  76   TARGET_WAITKIND_LOADED,
  77
  78   /* The program has forked.  A "related" process' ID is in value.related_pid.
  79      I.e., if the child forks, value.related_pid is the parent's ID.
  80      */
  81   TARGET_WAITKIND_FORKED,
  82
  83   /* The program has vforked.  A "related" process's ID is in value.related_pid.
  84      */
  85   TARGET_WAITKIND_VFORKED,
  86
  87   /* The program has exec'ed a new executable file.  The new file's pathname
  88      is pointed to by value.execd_pathname.
  89      */
  90   TARGET_WAITKIND_EXECD,
  91
  92   /* The program has entered or returned from a system call.  On HP-UX, this
  93      is used in the hardware watchpoint implementation.  The syscall's unique
  94      integer ID number is in value.syscall_id;
  95      */
  96   TARGET_WAITKIND_SYSCALL_ENTRY,
  97   TARGET_WAITKIND_SYSCALL_RETURN,
  98
  99   /* Nothing happened, but we stopped anyway.  This perhaps should be handled
 100      within target_wait, but I'm not sure target_wait should be resuming the
 101      inferior.  */
 102   TARGET_WAITKIND_SPURIOUS
 103   };
 104
 105 /* The numbering of these signals is chosen to match traditional unix
 106    signals (insofar as various unices use the same numbers, anyway).
 107    It is also the numbering of the GDB remote protocol.  Other remote
 108    protocols, if they use a different numbering, should make sure to
 109    translate appropriately.  */
 110
 111 /* This is based strongly on Unix/POSIX signals for several reasons:
 112    (1) This set of signals represents a widely-accepted attempt to
 113    represent events of this sort in a portable fashion, (2) we want a
 114    signal to make it from wait to child_wait to the user intact, (3) many
 115    remote protocols use a similar encoding.  However, it is
 116    recognized that this set of signals has limitations (such as not
 117    distinguishing between various kinds of SIGSEGV, or not
 118    distinguishing hitting a breakpoint from finishing a single step).
 119    So in the future we may get around this either by adding additional
 120    signals for breakpoint, single-step, etc., or by adding signal
 121    codes; the latter seems more in the spirit of what BSD, System V,
 122    etc. are doing to address these issues.  */
 123
 124 /* For an explanation of what each signal means, see
 125    target_signal_to_string.  */
 126
 127 enum target_signal {
 128   /* Used some places (e.g. stop_signal) to record the concept that
 129      there is no signal.  */
 130   TARGET_SIGNAL_0 = 0,
 131   TARGET_SIGNAL_FIRST = 0,
 132   TARGET_SIGNAL_HUP = 1,
 133   TARGET_SIGNAL_INT = 2,
 134   TARGET_SIGNAL_QUIT = 3,
 135   TARGET_SIGNAL_ILL = 4,
 136   TARGET_SIGNAL_TRAP = 5,
 137   TARGET_SIGNAL_ABRT = 6,
 138   TARGET_SIGNAL_EMT = 7,
 139   TARGET_SIGNAL_FPE = 8,
 140   TARGET_SIGNAL_KILL = 9,
 141   TARGET_SIGNAL_BUS = 10,
 142   TARGET_SIGNAL_SEGV = 11,
 143   TARGET_SIGNAL_SYS = 12,
 144   TARGET_SIGNAL_PIPE = 13,
 145   TARGET_SIGNAL_ALRM = 14,
 146   TARGET_SIGNAL_TERM = 15,
 147   TARGET_SIGNAL_URG = 16,
 148   TARGET_SIGNAL_STOP = 17,
 149   TARGET_SIGNAL_TSTP = 18,
 150   TARGET_SIGNAL_CONT = 19,
 151   TARGET_SIGNAL_CHLD = 20,
 152   TARGET_SIGNAL_TTIN = 21,
 153   TARGET_SIGNAL_TTOU = 22,
 154   TARGET_SIGNAL_IO = 23,
 155   TARGET_SIGNAL_XCPU = 24,
 156   TARGET_SIGNAL_XFSZ = 25,
 157   TARGET_SIGNAL_VTALRM = 26,
 158   TARGET_SIGNAL_PROF = 27,
 159   TARGET_SIGNAL_WINCH = 28,
 160   TARGET_SIGNAL_LOST = 29,
 161   TARGET_SIGNAL_USR1 = 30,
 162   TARGET_SIGNAL_USR2 = 31,
 163   TARGET_SIGNAL_PWR = 32,
 164   /* Similar to SIGIO.  Perhaps they should have the same number.  */
 165   TARGET_SIGNAL_POLL = 33,
 166   TARGET_SIGNAL_WIND = 34,
 167   TARGET_SIGNAL_PHONE = 35,
 168   TARGET_SIGNAL_WAITING = 36,
 169   TARGET_SIGNAL_LWP = 37,
 170   TARGET_SIGNAL_DANGER = 38,
 171   TARGET_SIGNAL_GRANT = 39,
 172   TARGET_SIGNAL_RETRACT = 40,
 173   TARGET_SIGNAL_MSG = 41,
 174   TARGET_SIGNAL_SOUND = 42,
 175   TARGET_SIGNAL_SAK = 43,
 176   TARGET_SIGNAL_PRIO = 44,
 177   TARGET_SIGNAL_REALTIME_33 = 45,
 178   TARGET_SIGNAL_REALTIME_34 = 46,
 179   TARGET_SIGNAL_REALTIME_35 = 47,
 180   TARGET_SIGNAL_REALTIME_36 = 48,
 181   TARGET_SIGNAL_REALTIME_37 = 49,
 182   TARGET_SIGNAL_REALTIME_38 = 50,
 183   TARGET_SIGNAL_REALTIME_39 = 51,
 184   TARGET_SIGNAL_REALTIME_40 = 52,
 185   TARGET_SIGNAL_REALTIME_41 = 53,
 186   TARGET_SIGNAL_REALTIME_42 = 54,
 187   TARGET_SIGNAL_REALTIME_43 = 55,
 188   TARGET_SIGNAL_REALTIME_44 = 56,
 189   TARGET_SIGNAL_REALTIME_45 = 57,
 190   TARGET_SIGNAL_REALTIME_46 = 58,
 191   TARGET_SIGNAL_REALTIME_47 = 59,
 192   TARGET_SIGNAL_REALTIME_48 = 60,
 193   TARGET_SIGNAL_REALTIME_49 = 61,
 194   TARGET_SIGNAL_REALTIME_50 = 62,
 195   TARGET_SIGNAL_REALTIME_51 = 63,
 196   TARGET_SIGNAL_REALTIME_52 = 64,
 197   TARGET_SIGNAL_REALTIME_53 = 65,
 198   TARGET_SIGNAL_REALTIME_54 = 66,
 199   TARGET_SIGNAL_REALTIME_55 = 67,
 200   TARGET_SIGNAL_REALTIME_56 = 68,
 201   TARGET_SIGNAL_REALTIME_57 = 69,
 202   TARGET_SIGNAL_REALTIME_58 = 70,
 203   TARGET_SIGNAL_REALTIME_59 = 71,
 204   TARGET_SIGNAL_REALTIME_60 = 72,
 205   TARGET_SIGNAL_REALTIME_61 = 73,
 206   TARGET_SIGNAL_REALTIME_62 = 74,
 207   TARGET_SIGNAL_REALTIME_63 = 75,
 208 #if defined(MACH) || defined(__MACH__)
 209   /* Mach exceptions */
 210   TARGET_EXC_BAD_ACCESS,
 211   TARGET_EXC_BAD_INSTRUCTION,
 212   TARGET_EXC_ARITHMETIC,
 213   TARGET_EXC_EMULATION,
 214   TARGET_EXC_SOFTWARE,
 215   TARGET_EXC_BREAKPOINT,
 216 #endif
 217   TARGET_SIGNAL_INFO,
 218
 219   /* Some signal we don't know about.  */
 220   TARGET_SIGNAL_UNKNOWN,
 221
 222   /* Use whatever signal we use when one is not specifically specified
 223      (for passing to proceed and so on).  */
 224   TARGET_SIGNAL_DEFAULT,
 225
 226   /* Last and unused enum value, for sizing arrays, etc.  */
 227   TARGET_SIGNAL_LAST
 228 };
 229
 230 struct target_waitstatus {
 231   enum target_waitkind kind;
 232
 233   /* Forked child pid, execd pathname, exit status or signal number.  */
 234   union {
 235     int integer;
 236     enum target_signal sig;
 237     int  related_pid;
 238     char *  execd_pathname;
 239     int  syscall_id;
 240   } value;
 241 };
 242
 243 /* Return the string for a signal.  */
 244 extern char *target_signal_to_string PARAMS ((enum target_signal));
 245
 246 /* Return the name (SIGHUP, etc.) for a signal.  */
 247 extern char *target_signal_to_name PARAMS ((enum target_signal));
 248
 249 /* Given a name (SIGHUP, etc.), return its signal.  */
 250 enum target_signal target_signal_from_name PARAMS ((char *));
 251
 252 \f
 253 /* If certain kinds of activity happen, target_wait should perform
 254    callbacks.  */
 255 /* Right now we just call (*TARGET_ACTIVITY_FUNCTION) if I/O is possible
 256    on TARGET_ACTIVITY_FD.   */
 257 extern int target_activity_fd;
 258 /* Returns zero to leave the inferior alone, one to interrupt it.  */
 259 extern int (*target_activity_function) PARAMS ((void));
 260 \f
 261 struct target_ops
 262 {
 263   char         *to_shortname;   /* Name this target type */
 264   char         *to_longname;    /* Name for printing */
 265   char         *to_doc;         /* Documentation.  Does not include trailing
 266                                    newline, and starts with a one-line descrip-
 267                                    tion (probably similar to to_longname). */
 268   void        (*to_open) PARAMS ((char *, int));
 269   void        (*to_close) PARAMS ((int));
 270   void        (*to_attach) PARAMS ((char *, int));
 271   void        (*to_post_attach) PARAMS ((int));
 272   void        (*to_require_attach) PARAMS ((char *, int));
 273   void        (*to_detach) PARAMS ((char *, int));
 274   void        (*to_require_detach) PARAMS ((int, char *, int));
 275   void        (*to_resume) PARAMS ((int, int, enum target_signal));
 276   int         (*to_wait) PARAMS ((int, struct target_waitstatus *));
 277   void        (*to_post_wait) PARAMS ((int, int));
 278   void        (*to_fetch_registers) PARAMS ((int));
 279   void        (*to_store_registers) PARAMS ((int));
 280   void        (*to_prepare_to_store) PARAMS ((void));
 281
 282   /* Transfer LEN bytes of memory between GDB address MYADDR and
 283      target address MEMADDR.  If WRITE, transfer them to the target, else
 284      transfer them from the target.  TARGET is the target from which we
 285      get this function.
 286
 287      Return value, N, is one of the following:
 288
 289      0 means that we can't handle this.  If errno has been set, it is the
 290      error which prevented us from doing it (FIXME: What about bfd_error?).
 291
 292      positive (call it N) means that we have transferred N bytes
 293      starting at MEMADDR.  We might be able to handle more bytes
 294      beyond this length, but no promises.
 295
 296      negative (call its absolute value N) means that we cannot
 297      transfer right at MEMADDR, but we could transfer at least
 298      something at MEMADDR + N.  */
 299
 300   int         (*to_xfer_memory) PARAMS ((CORE_ADDR memaddr, char *myaddr,
 301                                          int len, int write,
 302                                          struct target_ops * target));
 303
 304 #if 0
 305   /* Enable this after 4.12.  */
 306
 307   /* Search target memory.  Start at STARTADDR and take LEN bytes of
 308      target memory, and them with MASK, and compare to DATA.  If they
 309      match, set *ADDR_FOUND to the address we found it at, store the data
 310      we found at LEN bytes starting at DATA_FOUND, and return.  If
 311      not, add INCREMENT to the search address and keep trying until
 312      the search address is outside of the range [LORANGE,HIRANGE).
 313
 314      If we don't find anything, set *ADDR_FOUND to (CORE_ADDR)0 and return.  */
 315   void (*to_search) PARAMS ((int len, char *data, char *mask,
 316                              CORE_ADDR startaddr, int increment,
 317                              CORE_ADDR lorange, CORE_ADDR hirange,
 318                              CORE_ADDR *addr_found, char *data_found));
 319
 320 #define target_search(len, data, mask, startaddr, increment, lorange, hirange, addr_found, data_found)  \
 321   (*current_target.to_search) (len, data, mask, startaddr, increment, \
 322                                 lorange, hirange, addr_found, data_found)
 323 #endif /* 0 */
 324
 325   void        (*to_files_info) PARAMS ((struct target_ops *));
 326   int         (*to_insert_breakpoint) PARAMS ((CORE_ADDR, char *));
 327   int         (*to_remove_breakpoint) PARAMS ((CORE_ADDR, char *));
 328   void        (*to_terminal_init) PARAMS ((void));
 329   void        (*to_terminal_inferior) PARAMS ((void));
 330   void        (*to_terminal_ours_for_output) PARAMS ((void));
 331   void        (*to_terminal_ours) PARAMS ((void));
 332   void        (*to_terminal_info) PARAMS ((char *, int));
 333   void        (*to_kill) PARAMS ((void));
 334   void        (*to_load) PARAMS ((char *, int));
 335   int         (*to_lookup_symbol) PARAMS ((char *, CORE_ADDR *));
 336   void        (*to_create_inferior) PARAMS ((char *, char *, char **));
 337   void        (*to_post_startup_inferior) PARAMS ((int));
 338   void        (*to_acknowledge_created_inferior) PARAMS ((int));
 339   void        (*to_clone_and_follow_inferior) PARAMS ((int, int *));
 340   void        (*to_post_follow_inferior_by_clone) PARAMS ((void));
 341   int         (*to_insert_fork_catchpoint) PARAMS ((int));
 342   int         (*to_remove_fork_catchpoint) PARAMS ((int));
 343   int         (*to_insert_vfork_catchpoint) PARAMS ((int));
 344   int         (*to_remove_vfork_catchpoint) PARAMS ((int));
 345   int         (*to_has_forked) PARAMS ((int, int *));
 346   int         (*to_has_vforked) PARAMS ((int, int *));
 347   int         (*to_can_follow_vfork_prior_to_exec) PARAMS ((void));
 348   void        (*to_post_follow_vfork) PARAMS ((int, int, int, int));
 349   int         (*to_insert_exec_catchpoint) PARAMS ((int));
 350   int         (*to_remove_exec_catchpoint) PARAMS ((int));
 351   int         (*to_has_execd) PARAMS ((int, char **));
 352   int         (*to_reported_exec_events_per_exec_call) PARAMS ((void));
 353   int         (*to_has_syscall_event) PARAMS ((int, enum target_waitkind *, int *));
 354   int         (*to_has_exited) PARAMS ((int, int, int *));
 355   void        (*to_mourn_inferior) PARAMS ((void));
 356   int         (*to_can_run) PARAMS ((void));
 357   void        (*to_notice_signals) PARAMS ((int pid));
 358   int         (*to_thread_alive) PARAMS ((int pid));
 359   void        (*to_find_new_threads) PARAMS ((void));
 360   void        (*to_stop) PARAMS ((void));
 361   int         (*to_query) PARAMS ((int/*char*/, char *, char *, int *));
 362   struct symtab_and_line * (*to_enable_exception_callback) PARAMS ((enum exception_event_kind, int));
 363   struct exception_event_record * (*to_get_current_exception_event) PARAMS ((void));
 364   char *      (*to_pid_to_exec_file) PARAMS ((int pid));
 365   char *      (*to_core_file_to_sym_file) PARAMS ((char *));
 366   enum strata   to_stratum;
 367   struct target_ops
 368                 *DONT_USE;      /* formerly to_next */
 369   int           to_has_all_memory;
 370   int           to_has_memory;
 371   int           to_has_stack;
 372   int           to_has_registers;
 373   int           to_has_execution;
 374   int           to_has_thread_control;  /* control thread execution */
 375   struct section_table
 376                *to_sections;
 377   struct section_table
 378                *to_sections_end;
 379   int           to_magic;
 380   /* Need sub-structure for target machine related rather than comm related? */
 381 };
 382
 383 /* Magic number for checking ops size.  If a struct doesn't end with this
 384    number, somebody changed the declaration but didn't change all the
 385    places that initialize one.  */
 386
 387 #define OPS_MAGIC       3840
 388
 389 /* The ops structure for our "current" target process.  This should
 390    never be NULL.  If there is no target, it points to the dummy_target.  */
 391
 392 extern struct target_ops        current_target;
 393
 394 /* An item on the target stack.  */
 395
 396 struct target_stack_item
 397 {
 398   struct target_stack_item *next;
 399   struct target_ops *target_ops;
 400 };
 401
 402 /* The target stack.  */
 403
 404 extern struct target_stack_item *target_stack;
 405
 406 /* Define easy words for doing these operations on our current target.  */
 407
 408 #define target_shortname        (current_target.to_shortname)
 409 #define target_longname         (current_target.to_longname)
 410
 411 /* The open routine takes the rest of the parameters from the command,
 412    and (if successful) pushes a new target onto the stack.
 413    Targets should supply this routine, if only to provide an error message.  */
 414 #define target_open(name, from_tty)     \
 415         (*current_target.to_open) (name, from_tty)
 416
 417 /* Does whatever cleanup is required for a target that we are no longer
 418    going to be calling.  Argument says whether we are quitting gdb and
 419    should not get hung in case of errors, or whether we want a clean
 420    termination even if it takes a while.  This routine is automatically
 421    always called just before a routine is popped off the target stack.
 422    Closing file descriptors and freeing memory are typical things it should
 423    do.  */
 424
 425 #define target_close(quitting)  \
 426         (*current_target.to_close) (quitting)
 427
 428 /* Attaches to a process on the target side.  Arguments are as passed
 429    to the `attach' command by the user.  This routine can be called
 430    when the target is not on the target-stack, if the target_can_run
 431    routine returns 1; in that case, it must push itself onto the stack.
 432    Upon exit, the target should be ready for normal operations, and
 433    should be ready to deliver the status of the process immediately
 434    (without waiting) to an upcoming target_wait call.  */
 435
 436 #define target_attach(args, from_tty)   \
 437         (*current_target.to_attach) (args, from_tty)
 438
 439 /* The target_attach operation places a process under debugger control,
 440    and stops the process.
 441
 442    This operation provides a target-specific hook that allows the
 443    necessary bookkeeping to be performed after an attach completes.
 444    */
 445 #define target_post_attach(pid) \
 446         (*current_target.to_post_attach) (pid)
 447
 448 /* Attaches to a process on the target side, if not already attached.
 449    (If already attached, takes no action.)
 450
 451    This operation can be used to follow the child process of a fork.
 452    On some targets, such child processes of an original inferior process
 453    are automatically under debugger control, and thus do not require an
 454    actual attach operation.  */
 455
 456 #define target_require_attach(args, from_tty)   \
 457         (*current_target.to_require_attach) (args, from_tty)
 458
 459 /* Takes a program previously attached to and detaches it.
 460    The program may resume execution (some targets do, some don't) and will
 461    no longer stop on signals, etc.  We better not have left any breakpoints
 462    in the program or it'll die when it hits one.  ARGS is arguments
 463    typed by the user (e.g. a signal to send the process).  FROM_TTY
 464    says whether to be verbose or not.  */
 465
 466 extern void
 467 target_detach PARAMS ((char *, int));
 468
 469 /* Detaches from a process on the target side, if not already dettached.
 470    (If already detached, takes no action.)
 471
 472    This operation can be used to follow the parent process of a fork.
 473    On some targets, such child processes of an original inferior process
 474    are automatically under debugger control, and thus do require an actual
 475    detach operation.
 476
 477    PID is the process id of the child to detach from.
 478    ARGS is arguments typed by the user (e.g. a signal to send the process).
 479    FROM_TTY says whether to be verbose or not.  */
 480
 481 #define target_require_detach(pid, args, from_tty) \
 482         (*current_target.to_require_detach) (pid, args, from_tty)
 483
 484 /* Resume execution of the target process PID.  STEP says whether to
 485    single-step or to run free; SIGGNAL is the signal to be given to
 486    the target, or TARGET_SIGNAL_0 for no signal.  The caller may not
 487    pass TARGET_SIGNAL_DEFAULT.  */
 488
 489 #define target_resume(pid, step, siggnal)       \
 490         (*current_target.to_resume) (pid, step, siggnal)
 491
 492 /* Wait for process pid to do something.  Pid = -1 to wait for any pid
 493    to do something.  Return pid of child, or -1 in case of error;
 494    store status through argument pointer STATUS.  Note that it is
 495    *not* OK to return_to_top_level out of target_wait without popping
 496    the debugging target from the stack; GDB isn't prepared to get back
 497    to the prompt with a debugging target but without the frame cache,
 498    stop_pc, etc., set up.  */
 499
 500 #define target_wait(pid, status)                \
 501         (*current_target.to_wait) (pid, status)
 502
 503 /* The target_wait operation waits for a process event to occur, and
 504    thereby stop the process.
 505
 506    On some targets, certain events may happen in sequences.  gdb's
 507    correct response to any single event of such a sequence may require
 508    knowledge of what earlier events in the sequence have been seen.
 509
 510    This operation provides a target-specific hook that allows the
 511    necessary bookkeeping to be performed to track such sequences.
 512    */
 513
 514 #define target_post_wait(pid, status) \
 515         (*current_target.to_post_wait) (pid, status)
 516
 517 /* Fetch register REGNO, or all regs if regno == -1.  No result.  */
 518
 519 #define target_fetch_registers(regno)   \
 520         (*current_target.to_fetch_registers) (regno)
 521
 522 /* Store at least register REGNO, or all regs if REGNO == -1.
 523    It can store as many registers as it wants to, so target_prepare_to_store
 524    must have been previously called.  Calls error() if there are problems.  */
 525
 526 #define target_store_registers(regs)    \
 527         (*current_target.to_store_registers) (regs)
 528
 529 /* Get ready to modify the registers array.  On machines which store
 530    individual registers, this doesn't need to do anything.  On machines
 531    which store all the registers in one fell swoop, this makes sure
 532    that REGISTERS contains all the registers from the program being
 533    debugged.  */
 534
 535 #define target_prepare_to_store()       \
 536         (*current_target.to_prepare_to_store) ()
 537
 538 extern int target_read_string PARAMS ((CORE_ADDR, char **, int, int *));
 539
 540 extern int
 541 target_read_memory PARAMS ((CORE_ADDR memaddr, char *myaddr, int len));
 542
 543 extern int
 544 target_read_memory_section PARAMS ((CORE_ADDR memaddr, char *myaddr, int len,
 545                                     asection *bfd_section));
 546
 547 extern int
 548 target_read_memory_partial PARAMS ((CORE_ADDR, char *, int, int *));
 549
 550 extern int
 551 target_write_memory PARAMS ((CORE_ADDR, char *, int));
 552
 553 extern int
 554 xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 555
 556 extern int
 557 child_xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 558
 559 extern char *
 560 child_pid_to_exec_file PARAMS ((int));
 561
 562 extern char *
 563 child_core_file_to_sym_file PARAMS ((char *));
 564
 565 #if defined(CHILD_POST_ATTACH)
 566 extern void
 567 child_post_attach PARAMS ((int));
 568 #endif
 569
 570 extern void
 571 child_post_wait PARAMS ((int, int));
 572
 573 extern void
 574 child_post_startup_inferior PARAMS ((int));
 575
 576 extern void
 577 child_acknowledge_created_inferior PARAMS ((int));
 578
 579 extern void
 580 child_clone_and_follow_inferior PARAMS ((int, int *));
 581
 582 extern void
 583 child_post_follow_inferior_by_clone PARAMS ((void));
 584
 585 extern int
 586 child_insert_fork_catchpoint PARAMS ((int));
 587
 588 extern int
 589 child_remove_fork_catchpoint PARAMS ((int));
 590
 591 extern int
 592 child_insert_vfork_catchpoint PARAMS ((int));
 593
 594 extern int
 595 child_remove_vfork_catchpoint PARAMS ((int));
 596
 597 extern int
 598 child_has_forked PARAMS ((int, int *));
 599
 600 extern int
 601 child_has_vforked PARAMS ((int, int *));
 602
 603 extern void
 604 child_acknowledge_created_inferior PARAMS ((int));
 605
 606 extern int
 607 child_can_follow_vfork_prior_to_exec PARAMS ((void));
 608
 609 extern void
 610 child_post_follow_vfork PARAMS ((int, int, int, int));
 611
 612 extern int
 613 child_insert_exec_catchpoint PARAMS ((int));
 614
 615 extern int
 616 child_remove_exec_catchpoint PARAMS ((int));
 617
 618 extern int
 619 child_has_execd PARAMS ((int, char **));
 620
 621 extern int
 622 child_reported_exec_events_per_exec_call PARAMS ((void));
 623
 624 extern int
 625 child_has_syscall_event PARAMS ((int, enum target_waitkind *, int *));
 626
 627 extern int
 628 child_has_exited PARAMS ((int, int, int *));
 629
 630 extern int
 631 child_thread_alive PARAMS ((int));
 632
 633 /* From exec.c */
 634
 635 extern void
 636 print_section_info PARAMS ((struct target_ops *, bfd *));
 637
 638 /* Print a line about the current target.  */
 639
 640 #define target_files_info()     \
 641         (*current_target.to_files_info) (&current_target)
 642
 643 /* Insert a breakpoint at address ADDR in the target machine.
 644    SAVE is a pointer to memory allocated for saving the
 645    target contents.  It is guaranteed by the caller to be long enough
 646    to save "sizeof BREAKPOINT" bytes.  Result is 0 for success, or
 647    an errno value.  */
 648
 649 #define target_insert_breakpoint(addr, save)    \
 650         (*current_target.to_insert_breakpoint) (addr, save)
 651
 652 /* Remove a breakpoint at address ADDR in the target machine.
 653    SAVE is a pointer to the same save area
 654    that was previously passed to target_insert_breakpoint.
 655    Result is 0 for success, or an errno value.  */
 656
 657 #define target_remove_breakpoint(addr, save)    \
 658         (*current_target.to_remove_breakpoint) (addr, save)
 659
 660 /* Initialize the terminal settings we record for the inferior,
 661    before we actually run the inferior.  */
 662
 663 #define target_terminal_init() \
 664         (*current_target.to_terminal_init) ()
 665
 666 /* Put the inferior's terminal settings into effect.
 667    This is preparation for starting or resuming the inferior.  */
 668
 669 #define target_terminal_inferior() \
 670         (*current_target.to_terminal_inferior) ()
 671
 672 /* Put some of our terminal settings into effect,
 673    enough to get proper results from our output,
 674    but do not change into or out of RAW mode
 675    so that no input is discarded.
 676
 677    After doing this, either terminal_ours or terminal_inferior
 678    should be called to get back to a normal state of affairs.  */
 679
 680 #define target_terminal_ours_for_output() \
 681         (*current_target.to_terminal_ours_for_output) ()
 682
 683 /* Put our terminal settings into effect.
 684    First record the inferior's terminal settings
 685    so they can be restored properly later.  */
 686
 687 #define target_terminal_ours() \
 688         (*current_target.to_terminal_ours) ()
 689
 690 /* Print useful information about our terminal status, if such a thing
 691    exists.  */
 692
 693 #define target_terminal_info(arg, from_tty) \
 694         (*current_target.to_terminal_info) (arg, from_tty)
 695
 696 /* Kill the inferior process.   Make it go away.  */
 697
 698 #define target_kill() \
 699         (*current_target.to_kill) ()
 700
 701 /* Load an executable file into the target process.  This is expected to
 702    not only bring new code into the target process, but also to update
 703    GDB's symbol tables to match.  */
 704
 705 #define target_load(arg, from_tty) \
 706         (*current_target.to_load) (arg, from_tty)
 707
 708 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 709    name.  ADDRP is a CORE_ADDR * pointing to where the value of the symbol
 710    should be returned.  The result is 0 if successful, nonzero if the
 711    symbol does not exist in the target environment.  This function should
 712    not call error() if communication with the target is interrupted, since
 713    it is called from symbol reading, but should return nonzero, possibly
 714    doing a complain().  */
 715
 716 #define target_lookup_symbol(name, addrp)       \
 717   (*current_target.to_lookup_symbol) (name, addrp)
 718
 719 /* Start an inferior process and set inferior_pid to its pid.
 720    EXEC_FILE is the file to run.
 721    ALLARGS is a string containing the arguments to the program.
 722    ENV is the environment vector to pass.  Errors reported with error().
 723    On VxWorks and various standalone systems, we ignore exec_file.  */
 724
 725 #define target_create_inferior(exec_file, args, env)    \
 726         (*current_target.to_create_inferior) (exec_file, args, env)
 727
 728
 729 /* Some targets (such as ttrace-based HPUX) don't allow us to request
 730    notification of inferior events such as fork and vork immediately
 731    after the inferior is created.  (This because of how gdb gets an
 732    inferior created via invoking a shell to do it.  In such a scenario,
 733    if the shell init file has commands in it, the shell will fork and
 734    exec for each of those commands, and we will see each such fork
 735    event.  Very bad.)
 736
 737    Such targets will supply an appropriate definition for this function.
 738    */
 739 #define target_post_startup_inferior(pid) \
 740         (*current_target.to_post_startup_inferior) (pid)
 741
 742 /* On some targets, the sequence of starting up an inferior requires
 743    some synchronization between gdb and the new inferior process, PID.
 744    */
 745 #define target_acknowledge_created_inferior(pid) \
 746         (*current_target.to_acknowledge_created_inferior) (pid)
 747
 748 /* An inferior process has been created via a fork() or similar
 749    system call.  This function will clone the debugger, then ensure
 750    that CHILD_PID is attached to by that debugger.
 751
 752    FOLLOWED_CHILD is set TRUE on return *for the clone debugger only*,
 753    and FALSE otherwise.  (The original and clone debuggers can use this
 754    to determine which they are, if need be.)
 755
 756    (This is not a terribly useful feature without a GUI to prevent
 757    the two debuggers from competing for shell input.)
 758    */
 759 #define target_clone_and_follow_inferior(child_pid,followed_child) \
 760         (*current_target.to_clone_and_follow_inferior) (child_pid, followed_child)
 761
 762 /* This operation is intended to be used as the last in a sequence of
 763    steps taken when following both parent and child of a fork.  This
 764    is used by a clone of the debugger, which will follow the child.
 765
 766    The original debugger has detached from this process, and the
 767    clone has attached to it.
 768
 769    On some targets, this requires a bit of cleanup to make it work
 770    correctly.
 771    */
 772 #define target_post_follow_inferior_by_clone() \
 773         (*current_target.to_post_follow_inferior_by_clone) ()
 774
 775 /* On some targets, we can catch an inferior fork or vfork event when it
 776    occurs.  These functions insert/remove an already-created catchpoint for
 777    such events.
 778    */
 779 #define target_insert_fork_catchpoint(pid) \
 780         (*current_target.to_insert_fork_catchpoint) (pid)
 781
 782 #define target_remove_fork_catchpoint(pid) \
 783         (*current_target.to_remove_fork_catchpoint) (pid)
 784
 785 #define target_insert_vfork_catchpoint(pid) \
 786         (*current_target.to_insert_vfork_catchpoint) (pid)
 787
 788 #define target_remove_vfork_catchpoint(pid) \
 789         (*current_target.to_remove_vfork_catchpoint) (pid)
 790
 791 /* Returns TRUE if PID has invoked the fork() system call.  And,
 792    also sets CHILD_PID to the process id of the other ("child")
 793    inferior process that was created by that call.
 794    */
 795 #define target_has_forked(pid,child_pid) \
 796         (*current_target.to_has_forked) (pid,child_pid)
 797
 798 /* Returns TRUE if PID has invoked the vfork() system call.  And,
 799    also sets CHILD_PID to the process id of the other ("child")
 800    inferior process that was created by that call.
 801    */
 802 #define target_has_vforked(pid,child_pid) \
 803         (*current_target.to_has_vforked) (pid,child_pid)
 804
 805 /* Some platforms (such as pre-10.20 HP-UX) don't allow us to do
 806    anything to a vforked child before it subsequently calls exec().
 807    On such platforms, we say that the debugger cannot "follow" the
 808    child until it has vforked.
 809
 810    This function should be defined to return 1 by those targets
 811    which can allow the debugger to immediately follow a vforked
 812    child, and 0 if they cannot.
 813    */
 814 #define target_can_follow_vfork_prior_to_exec() \
 815         (*current_target.to_can_follow_vfork_prior_to_exec) ()
 816
 817 /* An inferior process has been created via a vfork() system call.
 818    The debugger has followed the parent, the child, or both.  The
 819    process of setting up for that follow may have required some
 820    target-specific trickery to track the sequence of reported events.
 821    If so, this function should be defined by those targets that
 822    require the debugger to perform cleanup or initialization after
 823    the vfork follow.
 824    */
 825 #define target_post_follow_vfork(parent_pid,followed_parent,child_pid,followed_child) \
 826         (*current_target.to_post_follow_vfork) (parent_pid,followed_parent,child_pid,followed_child)
 827
 828 /* On some targets, we can catch an inferior exec event when it
 829    occurs.  These functions insert/remove an already-created catchpoint
 830    for such events.
 831    */
 832 #define target_insert_exec_catchpoint(pid) \
 833         (*current_target.to_insert_exec_catchpoint) (pid)
 834
 835 #define target_remove_exec_catchpoint(pid) \
 836         (*current_target.to_remove_exec_catchpoint) (pid)
 837
 838 /* Returns TRUE if PID has invoked a flavor of the exec() system call.
 839    And, also sets EXECD_PATHNAME to the pathname of the executable file
 840    that was passed to exec(), and is now being executed.
 841    */
 842 #define target_has_execd(pid,execd_pathname) \
 843         (*current_target.to_has_execd) (pid,execd_pathname)
 844
 845 /* Returns the number of exec events that are reported when a process
 846    invokes a flavor of the exec() system call on this target, if exec
 847    events are being reported.
 848    */
 849 #define target_reported_exec_events_per_exec_call() \
 850         (*current_target.to_reported_exec_events_per_exec_call) ()
 851
 852 /* Returns TRUE if PID has reported a syscall event.  And, also sets
 853    KIND to the appropriate TARGET_WAITKIND_, and sets SYSCALL_ID to
 854    the unique integer ID of the syscall.
 855    */
 856 #define target_has_syscall_event(pid,kind,syscall_id) \
 857   (*current_target.to_has_syscall_event) (pid,kind,syscall_id)
 858
 859 /* Returns TRUE if PID has exited.  And, also sets EXIT_STATUS to the
 860    exit code of PID, if any.
 861    */
 862 #define target_has_exited(pid,wait_status,exit_status) \
 863         (*current_target.to_has_exited) (pid,wait_status,exit_status)
 864
 865 /* The debugger has completed a blocking wait() call.  There is now
 866    some process event that must be processed.  This function should
 867    be defined by those targets that require the debugger to perform
 868    cleanup or internal state changes in response to the process event.
 869    */
 870
 871 /* The inferior process has died.  Do what is right.  */
 872
 873 #define target_mourn_inferior() \
 874         (*current_target.to_mourn_inferior) ()
 875
 876 /* Does target have enough data to do a run or attach command? */
 877
 878 #define target_can_run(t) \
 879         ((t)->to_can_run) ()
 880
 881 /* post process changes to signal handling in the inferior.  */
 882
 883 #define target_notice_signals(pid) \
 884         (*current_target.to_notice_signals) (pid)
 885
 886 /* Check to see if a thread is still alive.  */
 887
 888 #define target_thread_alive(pid) \
 889         (*current_target.to_thread_alive) (pid)
 890
 891 /* Query for new threads and add them to the thread list.  */
 892
 893 #define target_find_new_threads() \
 894      do { \
 895        if (current_target.to_find_new_threads) \
 896          (*current_target.to_find_new_threads) (); \
 897      } while (0);
 898
 899 /* Make target stop in a continuable fashion.  (For instance, under Unix, this
 900    should act like SIGSTOP).  This function is normally used by GUIs to
 901    implement a stop button.  */
 902
 903 #define target_stop current_target.to_stop
 904
 905 /* Queries the target side for some information.  The first argument is a
 906    letter specifying the type of the query, which is used to determine who
 907    should process it.  The second argument is a string that specifies which
 908    information is desired and the third is a buffer that carries back the
 909    response from the target side. The fourth parameter is the size of the
 910    output buffer supplied. */
 911
 912 #define target_query(query_type, query, resp_buffer, bufffer_size)      \
 913         (*current_target.to_query) (query_type, query, resp_buffer, bufffer_size)
 914
 915 /* Get the symbol information for a breakpointable routine called when
 916    an exception event occurs.
 917    Intended mainly for C++, and for those
 918    platforms/implementations where such a callback mechanism is available,
 919    e.g. HP-UX with ANSI C++ (aCC).  Some compilers (e.g. g++) support
 920    different mechanisms for debugging exceptions. */
 921
 922 #define target_enable_exception_callback(kind, enable) \
 923         (*current_target.to_enable_exception_callback) (kind, enable)
 924
 925 /* Get the current exception event kind -- throw or catch, etc. */
 926
 927 #define target_get_current_exception_event() \
 928         (*current_target.to_get_current_exception_event) ()
 929
 930 /* Pointer to next target in the chain, e.g. a core file and an exec file.  */
 931
 932 #define target_next \
 933         (current_target.to_next)
 934
 935 /* Does the target include all of memory, or only part of it?  This
 936    determines whether we look up the target chain for other parts of
 937    memory if this target can't satisfy a request.  */
 938
 939 #define target_has_all_memory   \
 940         (current_target.to_has_all_memory)
 941
 942 /* Does the target include memory?  (Dummy targets don't.)  */
 943
 944 #define target_has_memory       \
 945         (current_target.to_has_memory)
 946
 947 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 948    we start a process.)  */
 949
 950 #define target_has_stack        \
 951         (current_target.to_has_stack)
 952
 953 /* Does the target have registers?  (Exec files don't.)  */
 954
 955 #define target_has_registers    \
 956         (current_target.to_has_registers)
 957
 958 /* Does the target have execution?  Can we make it jump (through
 959    hoops), or pop its stack a few times?  FIXME: If this is to work that
 960    way, it needs to check whether an inferior actually exists.
 961    remote-udi.c and probably other targets can be the current target
 962    when the inferior doesn't actually exist at the moment.  Right now
 963    this just tells us whether this target is *capable* of execution.  */
 964
 965 #define target_has_execution    \
 966         (current_target.to_has_execution)
 967
 968 /* Can the target support the debugger control of thread execution?
 969    a) Can it lock the thread scheduler?
 970    b) Can it switch the currently running thread?  */
 971
 972 #define target_can_lock_scheduler \
 973         (current_target.to_has_thread_control & tc_schedlock)
 974
 975 #define target_can_switch_threads \
 976         (current_target.to_has_thread_control & tc_switch)
 977
 978 extern void target_link PARAMS ((char *, CORE_ADDR *));
 979
 980 /* Converts a process id to a string.  Usually, the string just contains
 981    `process xyz', but on some systems it may contain
 982    `process xyz thread abc'.  */
 983
 984 #ifndef target_pid_to_str
 985 #define target_pid_to_str(PID) \
 986         normal_pid_to_str (PID)
 987 extern char *normal_pid_to_str PARAMS ((int pid));
 988 #endif
 989
 990 #ifndef target_tid_to_str
 991 #define target_tid_to_str(PID) \
 992         normal_pid_to_str (PID)
 993 extern char *normal_pid_to_str PARAMS ((int pid));
 994 #endif
 995
 996
 997 #ifndef target_new_objfile
 998 #define target_new_objfile(OBJFILE)
 999 #endif
1000
1001 #ifndef target_pid_or_tid_to_str
1002 #define target_pid_or_tid_to_str(ID) \
1003         normal_pid_to_str (ID)
1004 #endif
1005
1006 /* Attempts to find the pathname of the executable file
1007    that was run to create a specified process.
1008
1009    The process PID must be stopped when this operation is used.
1010
1011    If the executable file cannot be determined, NULL is returned.
1012
1013    Else, a pointer to a character string containing the pathname
1014    is returned.  This string should be copied into a buffer by
1015    the client if the string will not be immediately used, or if
1016    it must persist.
1017    */
1018
1019 #define target_pid_to_exec_file(pid) \
1020         (current_target.to_pid_to_exec_file) (pid)
1021
1022 /* Hook to call target-dependant code after reading in a new symbol table. */
1023
1024 #ifndef TARGET_SYMFILE_POSTREAD
1025 #define TARGET_SYMFILE_POSTREAD(OBJFILE)
1026 #endif
1027
1028 /* Hook to call target dependant code just after inferior target process has
1029    started.  */
1030
1031 #ifndef TARGET_CREATE_INFERIOR_HOOK
1032 #define TARGET_CREATE_INFERIOR_HOOK(PID)
1033 #endif
1034
1035 /* Hardware watchpoint interfaces.  */
1036
1037 /* Returns non-zero if we were stopped by a hardware watchpoint (memory read or
1038    write).  */
1039
1040 #ifndef STOPPED_BY_WATCHPOINT
1041 #define STOPPED_BY_WATCHPOINT(w) 0
1042 #endif
1043
1044 /* HP-UX supplies these operations, which respectively disable and enable
1045    the memory page-protections that are used to implement hardware watchpoints
1046    on that platform.  See wait_for_inferior's use of these.
1047    */
1048 #if !defined(TARGET_DISABLE_HW_WATCHPOINTS)
1049 #define TARGET_DISABLE_HW_WATCHPOINTS(pid)
1050 #endif
1051
1052 #if !defined(TARGET_ENABLE_HW_WATCHPOINTS)
1053 #define TARGET_ENABLE_HW_WATCHPOINTS(pid)
1054 #endif
1055
1056 /* Provide defaults for systems that don't support hardware watchpoints. */
1057
1058 #ifndef TARGET_HAS_HARDWARE_WATCHPOINTS
1059
1060 /* Returns non-zero if we can set a hardware watchpoint of type TYPE.  TYPE is
1061    one of bp_hardware_watchpoint, bp_read_watchpoint, bp_write_watchpoint, or
1062    bp_hardware_breakpoint.  CNT is the number of such watchpoints used so far
1063    (including this one?).  OTHERTYPE is who knows what...  */
1064
1065 #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(TYPE,CNT,OTHERTYPE) 0
1066
1067 #if !defined(TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT)
1068 #define TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT(byte_count) \
1069         (LONGEST)(byte_count) <= REGISTER_SIZE
1070 #endif
1071
1072 /* However, some addresses may not be profitable to use hardware to watch,
1073    or may be difficult to understand when the addressed object is out of
1074    scope, and hence should be unwatched.  On some targets, this may have
1075    severe performance penalties, such that we might as well use regular
1076    watchpoints, and save (possibly precious) hardware watchpoints for other
1077    locations.
1078    */
1079 #if !defined(TARGET_RANGE_PROFITABLE_FOR_HW_WATCHPOINT)
1080 #define TARGET_RANGE_PROFITABLE_FOR_HW_WATCHPOINT(pid,start,len) 0
1081 #endif
1082
1083
1084 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.  TYPE is 0
1085    for write, 1 for read, and 2 for read/write accesses.  Returns 0 for
1086    success, non-zero for failure.  */
1087
1088 #define target_remove_watchpoint(ADDR,LEN,TYPE) -1
1089 #define target_insert_watchpoint(ADDR,LEN,TYPE) -1
1090
1091 #endif /* TARGET_HAS_HARDWARE_WATCHPOINTS */
1092
1093 #ifndef target_insert_hw_breakpoint
1094 #define target_remove_hw_breakpoint(ADDR,SHADOW) -1
1095 #define target_insert_hw_breakpoint(ADDR,SHADOW) -1
1096 #endif
1097
1098 #ifndef target_stopped_data_address
1099 #define target_stopped_data_address() 0
1100 #endif
1101
1102 /* If defined, then we need to decr pc by this much after a hardware break-
1103    point.  Presumably this overrides DECR_PC_AFTER_BREAK...  */
1104
1105 #ifndef DECR_PC_AFTER_HW_BREAK
1106 #define DECR_PC_AFTER_HW_BREAK 0
1107 #endif
1108
1109 /* Sometimes gdb may pick up what appears to be a valid target address
1110    from a minimal symbol, but the value really means, essentially,
1111    "This is an index into a table which is populated when the inferior
1112    is run.  Therefore, do not attempt to use this as a PC."
1113    */
1114 #if !defined(PC_REQUIRES_RUN_BEFORE_USE)
1115 #define PC_REQUIRES_RUN_BEFORE_USE(pc) (0)
1116 #endif
1117
1118 /* This will only be defined by a target that supports catching vfork events,
1119    such as HP-UX.
1120
1121    On some targets (such as HP-UX 10.20 and earlier), resuming a newly vforked
1122    child process after it has exec'd, causes the parent process to resume as
1123    well.  To prevent the parent from running spontaneously, such targets should
1124    define this to a function that prevents that from happening.
1125    */
1126 #if !defined(ENSURE_VFORKING_PARENT_REMAINS_STOPPED)
1127 #define ENSURE_VFORKING_PARENT_REMAINS_STOPPED(PID) (0)
1128 #endif
1129
1130 /* This will only be defined by a target that supports catching vfork events,
1131    such as HP-UX.
1132
1133    On some targets (such as HP-UX 10.20 and earlier), a newly vforked child
1134    process must be resumed when it delivers its exec event, before the parent
1135    vfork event will be delivered to us.
1136    */
1137 #if !defined(RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK)
1138 #define RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK() (0)
1139 #endif
1140
1141 /* Routines for maintenance of the target structures...
1142
1143    add_target:   Add a target to the list of all possible targets.
1144
1145    push_target:  Make this target the top of the stack of currently used
1146                  targets, within its particular stratum of the stack.  Result
1147                  is 0 if now atop the stack, nonzero if not on top (maybe
1148                  should warn user).
1149
1150    unpush_target: Remove this from the stack of currently used targets,
1151                  no matter where it is on the list.  Returns 0 if no
1152                  change, 1 if removed from stack.
1153
1154    pop_target:   Remove the top thing on the stack of current targets.  */
1155
1156 extern void
1157 add_target PARAMS ((struct target_ops *));
1158
1159 extern int
1160 push_target PARAMS ((struct target_ops *));
1161
1162 extern int
1163 unpush_target PARAMS ((struct target_ops *));
1164
1165 extern void
1166 target_preopen PARAMS ((int));
1167
1168 extern void
1169 pop_target PARAMS ((void));
1170
1171 /* Struct section_table maps address ranges to file sections.  It is
1172    mostly used with BFD files, but can be used without (e.g. for handling
1173    raw disks, or files not in formats handled by BFD).  */
1174
1175 struct section_table {
1176   CORE_ADDR addr;               /* Lowest address in section */
1177   CORE_ADDR endaddr;            /* 1+highest address in section */
1178
1179   sec_ptr the_bfd_section;
1180
1181   bfd      *bfd;                /* BFD file pointer */
1182 };
1183
1184 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
1185    Returns 0 if OK, 1 on error.  */
1186
1187 extern int
1188 build_section_table PARAMS ((bfd *, struct section_table **,
1189                              struct section_table **));
1190
1191 /* From mem-break.c */
1192
1193 extern int memory_remove_breakpoint PARAMS ((CORE_ADDR, char *));
1194
1195 extern int memory_insert_breakpoint PARAMS ((CORE_ADDR, char *));
1196
1197 extern breakpoint_from_pc_fn memory_breakpoint_from_pc;
1198 #ifndef BREAKPOINT_FROM_PC
1199 #define BREAKPOINT_FROM_PC(pcptr, lenptr) memory_breakpoint_from_pc (pcptr, lenptr)
1200 #endif
1201
1202
1203 /* From target.c */
1204
1205 extern void
1206 initialize_targets PARAMS ((void));
1207
1208 extern void
1209 noprocess PARAMS ((void));
1210
1211 extern void
1212 find_default_attach PARAMS ((char *, int));
1213
1214 void
1215 find_default_require_attach PARAMS ((char *, int));
1216
1217 void
1218 find_default_require_detach PARAMS ((int, char *, int));
1219
1220 extern void
1221 find_default_create_inferior PARAMS ((char *, char *, char **));
1222
1223 void
1224 find_default_clone_and_follow_inferior PARAMS ((int, int *));
1225
1226 extern struct target_ops *find_run_target PARAMS ((void));
1227
1228 extern struct target_ops *
1229 find_core_target PARAMS ((void));
1230 \f
1231 /* Stuff that should be shared among the various remote targets.  */
1232
1233 /* Debugging level.  0 is off, and non-zero values mean to print some debug
1234    information (higher values, more information).  */
1235 extern int remote_debug;
1236
1237 /* Speed in bits per second, or -1 which means don't mess with the speed.  */
1238 extern int baud_rate;
1239 /* Timeout limit for response from target. */
1240 extern int remote_timeout;
1241
1242 extern asection *target_memory_bfd_section;
1243 \f
1244 /* Functions for helping to write a native target.  */
1245
1246 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
1247 extern void store_waitstatus PARAMS ((struct target_waitstatus *, int));
1248
1249 /* Convert between host signal numbers and enum target_signal's.  */
1250 extern enum target_signal target_signal_from_host PARAMS ((int));
1251 extern int target_signal_to_host PARAMS ((enum target_signal));
1252
1253 /* Convert from a number used in a GDB command to an enum target_signal.  */
1254 extern enum target_signal target_signal_from_command PARAMS ((int));
1255
1256 /* Any target can call this to switch to remote protocol (in remote.c). */
1257 extern void push_remote_target PARAMS ((char *name, int from_tty));
1258 \f
1259 /* Imported from machine dependent code */
1260
1261 #ifndef SOFTWARE_SINGLE_STEP_P
1262 #define SOFTWARE_SINGLE_STEP_P 0
1263 #define SOFTWARE_SINGLE_STEP(sig,bp_p) abort ()
1264 #endif /* SOFTWARE_SINGLE_STEP_P */
1265
1266 /* Blank target vector entries are initialized to target_ignore. */
1267 void target_ignore PARAMS ((void));
1268
1269 /* Macro for getting target's idea of a frame pointer.
1270    FIXME: GDB's whole scheme for dealing with "frames" and
1271    "frame pointers" needs a serious shakedown.  */
1272 #ifndef TARGET_VIRTUAL_FRAME_POINTER
1273 #define TARGET_VIRTUAL_FRAME_POINTER(ADDR, REGP, OFFP) \
1274    do { *(REGP) = FP_REGNUM; *(OFFP) =  0; } while (0)
1275 #endif /* TARGET_VIRTUAL_FRAME_POINTER */
1276
1277 #endif  /* !defined (TARGET_H) */