gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2
   3    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   4    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
   5    Free Software Foundation, Inc.
   6
   7    Contributed by Cygnus Support.  Written by John Gilmore.
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24    Boston, MA 02110-1301, USA.  */
  25
  26 #if !defined (TARGET_H)
  27 #define TARGET_H
  28
  29 struct objfile;
  30 struct ui_file;
  31 struct mem_attrib;
  32 struct target_ops;
  33 struct bp_target_info;
  34
  35 /* This include file defines the interface between the main part
  36    of the debugger, and the part which is target-specific, or
  37    specific to the communications interface between us and the
  38    target.
  39
  40    A TARGET is an interface between the debugger and a particular
  41    kind of file or process.  Targets can be STACKED in STRATA,
  42    so that more than one target can potentially respond to a request.
  43    In particular, memory accesses will walk down the stack of targets
  44    until they find a target that is interested in handling that particular
  45    address.  STRATA are artificial boundaries on the stack, within
  46    which particular kinds of targets live.  Strata exist so that
  47    people don't get confused by pushing e.g. a process target and then
  48    a file target, and wondering why they can't see the current values
  49    of variables any more (the file target is handling them and they
  50    never get to the process target).  So when you push a file target,
  51    it goes into the file stratum, which is always below the process
  52    stratum.  */
  53
  54 #include "bfd.h"
  55 #include "symtab.h"
  56 #include "dcache.h"
  57 #include "memattr.h"
  58
  59 enum strata
  60   {
  61     dummy_stratum,              /* The lowest of the low */
  62     file_stratum,               /* Executable files, etc */
  63     core_stratum,               /* Core dump files */
  64     download_stratum,           /* Downloading of remote targets */
  65     process_stratum,            /* Executing processes */
  66     thread_stratum              /* Executing threads */
  67   };
  68
  69 enum thread_control_capabilities
  70   {
  71     tc_none = 0,                /* Default: can't control thread execution.  */
  72     tc_schedlock = 1,           /* Can lock the thread scheduler.  */
  73     tc_switch = 2               /* Can switch the running thread on demand.  */
  74   };
  75
  76 /* Stuff for target_wait.  */
  77
  78 /* Generally, what has the program done?  */
  79 enum target_waitkind
  80   {
  81     /* The program has exited.  The exit status is in value.integer.  */
  82     TARGET_WAITKIND_EXITED,
  83
  84     /* The program has stopped with a signal.  Which signal is in
  85        value.sig.  */
  86     TARGET_WAITKIND_STOPPED,
  87
  88     /* The program has terminated with a signal.  Which signal is in
  89        value.sig.  */
  90     TARGET_WAITKIND_SIGNALLED,
  91
  92     /* The program is letting us know that it dynamically loaded something
  93        (e.g. it called load(2) on AIX).  */
  94     TARGET_WAITKIND_LOADED,
  95
  96     /* The program has forked.  A "related" process' ID is in
  97        value.related_pid.  I.e., if the child forks, value.related_pid
  98        is the parent's ID.  */
  99
 100     TARGET_WAITKIND_FORKED,
 101
 102     /* The program has vforked.  A "related" process's ID is in
 103        value.related_pid.  */
 104
 105     TARGET_WAITKIND_VFORKED,
 106
 107     /* The program has exec'ed a new executable file.  The new file's
 108        pathname is pointed to by value.execd_pathname.  */
 109
 110     TARGET_WAITKIND_EXECD,
 111
 112     /* The program has entered or returned from a system call.  On
 113        HP-UX, this is used in the hardware watchpoint implementation.
 114        The syscall's unique integer ID number is in value.syscall_id */
 115
 116     TARGET_WAITKIND_SYSCALL_ENTRY,
 117     TARGET_WAITKIND_SYSCALL_RETURN,
 118
 119     /* Nothing happened, but we stopped anyway.  This perhaps should be handled
 120        within target_wait, but I'm not sure target_wait should be resuming the
 121        inferior.  */
 122     TARGET_WAITKIND_SPURIOUS,
 123
 124     /* An event has occured, but we should wait again.
 125        Remote_async_wait() returns this when there is an event
 126        on the inferior, but the rest of the world is not interested in
 127        it. The inferior has not stopped, but has just sent some output
 128        to the console, for instance. In this case, we want to go back
 129        to the event loop and wait there for another event from the
 130        inferior, rather than being stuck in the remote_async_wait()
 131        function. This way the event loop is responsive to other events,
 132        like for instance the user typing.  */
 133     TARGET_WAITKIND_IGNORE
 134   };
 135
 136 struct target_waitstatus
 137   {
 138     enum target_waitkind kind;
 139
 140     /* Forked child pid, execd pathname, exit status or signal number.  */
 141     union
 142       {
 143         int integer;
 144         enum target_signal sig;
 145         int related_pid;
 146         char *execd_pathname;
 147         int syscall_id;
 148       }
 149     value;
 150   };
 151
 152 /* Possible types of events that the inferior handler will have to
 153    deal with.  */
 154 enum inferior_event_type
 155   {
 156     /* There is a request to quit the inferior, abandon it.  */
 157     INF_QUIT_REQ,
 158     /* Process a normal inferior event which will result in target_wait
 159        being called.  */
 160     INF_REG_EVENT,
 161     /* Deal with an error on the inferior.  */
 162     INF_ERROR,
 163     /* We are called because a timer went off.  */
 164     INF_TIMER,
 165     /* We are called to do stuff after the inferior stops.  */
 166     INF_EXEC_COMPLETE,
 167     /* We are called to do some stuff after the inferior stops, but we
 168        are expected to reenter the proceed() and
 169        handle_inferior_event() functions. This is used only in case of
 170        'step n' like commands.  */
 171     INF_EXEC_CONTINUE
 172   };
 173
 174 /* Return the string for a signal.  */
 175 extern char *target_signal_to_string (enum target_signal);
 176
 177 /* Return the name (SIGHUP, etc.) for a signal.  */
 178 extern char *target_signal_to_name (enum target_signal);
 179
 180 /* Given a name (SIGHUP, etc.), return its signal.  */
 181 enum target_signal target_signal_from_name (char *);
 182 \f
 183 /* Target objects which can be transfered using target_read,
 184    target_write, et cetera.  */
 185
 186 enum target_object
 187 {
 188   /* AVR target specific transfer.  See "avr-tdep.c" and "remote.c".  */
 189   TARGET_OBJECT_AVR,
 190   /* Transfer up-to LEN bytes of memory starting at OFFSET.  */
 191   TARGET_OBJECT_MEMORY,
 192   /* Memory, avoiding GDB's data cache and trusting the executable.
 193      Target implementations of to_xfer_partial never need to handle
 194      this object, and most callers should not use it.  */
 195   TARGET_OBJECT_RAW_MEMORY,
 196   /* Kernel Unwind Table.  See "ia64-tdep.c".  */
 197   TARGET_OBJECT_UNWIND_TABLE,
 198   /* Transfer auxilliary vector.  */
 199   TARGET_OBJECT_AUXV,
 200   /* StackGhost cookie.  See "sparc-tdep.c".  */
 201   TARGET_OBJECT_WCOOKIE
 202
 203   /* Possible future objects: TARGET_OBJECT_FILE, TARGET_OBJECT_PROC, ... */
 204 };
 205
 206 /* Request that OPS transfer up to LEN 8-bit bytes of the target's
 207    OBJECT.  The OFFSET, for a seekable object, specifies the
 208    starting point.  The ANNEX can be used to provide additional
 209    data-specific information to the target.
 210
 211    Return the number of bytes actually transfered, or -1 if the
 212    transfer is not supported or otherwise fails.  Return of a positive
 213    value less than LEN indicates that no further transfer is possible.
 214    Unlike the raw to_xfer_partial interface, callers of these
 215    functions do not need to retry partial transfers.  */
 216
 217 extern LONGEST target_read (struct target_ops *ops,
 218                             enum target_object object,
 219                             const char *annex, gdb_byte *buf,
 220                             ULONGEST offset, LONGEST len);
 221
 222 extern LONGEST target_write (struct target_ops *ops,
 223                              enum target_object object,
 224                              const char *annex, const gdb_byte *buf,
 225                              ULONGEST offset, LONGEST len);
 226
 227 /* Similar to target_write, except that it also calls PROGRESS
 228    with the number of bytes written and the opaque BATON after
 229    every partial write.  This is useful for progress reporting
 230    and user interaction while writing data.  To abort the transfer,
 231    the progress callback can throw an exception.  */
 232 LONGEST target_write_with_progress (struct target_ops *ops,
 233                                     enum target_object object,
 234                                     const char *annex, const gdb_byte *buf,
 235                                     ULONGEST offset, LONGEST len,
 236                                     void (*progress) (ULONGEST, void *),
 237                                     void *baton);
 238
 239 /* Wrapper to perform a full read of unknown size.  OBJECT/ANNEX will
 240    be read using OPS.  The return value will be -1 if the transfer
 241    fails or is not supported; 0 if the object is empty; or the length
 242    of the object otherwise.  If a positive value is returned, a
 243    sufficiently large buffer will be allocated using xmalloc and
 244    returned in *BUF_P containing the contents of the object.
 245
 246    This method should be used for objects sufficiently small to store
 247    in a single xmalloc'd buffer, when no fixed bound on the object's
 248    size is known in advance.  Don't try to read TARGET_OBJECT_MEMORY
 249    through this function.  */
 250
 251 extern LONGEST target_read_alloc (struct target_ops *ops,
 252                                   enum target_object object,
 253                                   const char *annex, gdb_byte **buf_p);
 254
 255 /* Read OBJECT/ANNEX using OPS.  The result is NUL-terminated and
 256    returned as a string, allocated using xmalloc.  If an error occurs
 257    or the transfer is unsupported, NULL is returned.  Empty objects
 258    are returned as allocated but empty strings.  A warning is issued
 259    if the result contains any embedded NUL bytes.  */
 260
 261 extern char *target_read_stralloc (struct target_ops *ops,
 262                                    enum target_object object,
 263                                    const char *annex);
 264
 265 /* Wrappers to target read/write that perform memory transfers.  They
 266    throw an error if the memory transfer fails.
 267
 268    NOTE: cagney/2003-10-23: The naming schema is lifted from
 269    "frame.h".  The parameter order is lifted from get_frame_memory,
 270    which in turn lifted it from read_memory.  */
 271
 272 extern void get_target_memory (struct target_ops *ops, CORE_ADDR addr,
 273                                gdb_byte *buf, LONGEST len);
 274 extern ULONGEST get_target_memory_unsigned (struct target_ops *ops,
 275                                             CORE_ADDR addr, int len);
 276 \f
 277
 278 /* If certain kinds of activity happen, target_wait should perform
 279    callbacks.  */
 280 /* Right now we just call (*TARGET_ACTIVITY_FUNCTION) if I/O is possible
 281    on TARGET_ACTIVITY_FD.  */
 282 extern int target_activity_fd;
 283 /* Returns zero to leave the inferior alone, one to interrupt it.  */
 284 extern int (*target_activity_function) (void);
 285 \f
 286 struct thread_info;             /* fwd decl for parameter list below: */
 287
 288 struct target_ops
 289   {
 290     struct target_ops *beneath; /* To the target under this one.  */
 291     char *to_shortname;         /* Name this target type */
 292     char *to_longname;          /* Name for printing */
 293     char *to_doc;               /* Documentation.  Does not include trailing
 294                                    newline, and starts with a one-line descrip-
 295                                    tion (probably similar to to_longname).  */
 296     /* Per-target scratch pad.  */
 297     void *to_data;
 298     /* The open routine takes the rest of the parameters from the
 299        command, and (if successful) pushes a new target onto the
 300        stack.  Targets should supply this routine, if only to provide
 301        an error message.  */
 302     void (*to_open) (char *, int);
 303     /* Old targets with a static target vector provide "to_close".
 304        New re-entrant targets provide "to_xclose" and that is expected
 305        to xfree everything (including the "struct target_ops").  */
 306     void (*to_xclose) (struct target_ops *targ, int quitting);
 307     void (*to_close) (int);
 308     void (*to_attach) (char *, int);
 309     void (*to_post_attach) (int);
 310     void (*to_detach) (char *, int);
 311     void (*to_disconnect) (struct target_ops *, char *, int);
 312     void (*to_resume) (ptid_t, int, enum target_signal);
 313     ptid_t (*to_wait) (ptid_t, struct target_waitstatus *);
 314     void (*to_fetch_registers) (int);
 315     void (*to_store_registers) (int);
 316     void (*to_prepare_to_store) (void);
 317
 318     /* Transfer LEN bytes of memory between GDB address MYADDR and
 319        target address MEMADDR.  If WRITE, transfer them to the target, else
 320        transfer them from the target.  TARGET is the target from which we
 321        get this function.
 322
 323        Return value, N, is one of the following:
 324
 325        0 means that we can't handle this.  If errno has been set, it is the
 326        error which prevented us from doing it (FIXME: What about bfd_error?).
 327
 328        positive (call it N) means that we have transferred N bytes
 329        starting at MEMADDR.  We might be able to handle more bytes
 330        beyond this length, but no promises.
 331
 332        negative (call its absolute value N) means that we cannot
 333        transfer right at MEMADDR, but we could transfer at least
 334        something at MEMADDR + N.
 335
 336        NOTE: cagney/2004-10-01: This has been entirely superseeded by
 337        to_xfer_partial and inferior inheritance.  */
 338
 339     int (*deprecated_xfer_memory) (CORE_ADDR memaddr, gdb_byte *myaddr,
 340                                    int len, int write,
 341                                    struct mem_attrib *attrib,
 342                                    struct target_ops *target);
 343
 344     void (*to_files_info) (struct target_ops *);
 345     int (*to_insert_breakpoint) (struct bp_target_info *);
 346     int (*to_remove_breakpoint) (struct bp_target_info *);
 347     int (*to_can_use_hw_breakpoint) (int, int, int);
 348     int (*to_insert_hw_breakpoint) (struct bp_target_info *);
 349     int (*to_remove_hw_breakpoint) (struct bp_target_info *);
 350     int (*to_remove_watchpoint) (CORE_ADDR, int, int);
 351     int (*to_insert_watchpoint) (CORE_ADDR, int, int);
 352     int (*to_stopped_by_watchpoint) (void);
 353     int to_have_continuable_watchpoint;
 354     int (*to_stopped_data_address) (struct target_ops *, CORE_ADDR *);
 355     int (*to_region_ok_for_hw_watchpoint) (CORE_ADDR, int);
 356     void (*to_terminal_init) (void);
 357     void (*to_terminal_inferior) (void);
 358     void (*to_terminal_ours_for_output) (void);
 359     void (*to_terminal_ours) (void);
 360     void (*to_terminal_save_ours) (void);
 361     void (*to_terminal_info) (char *, int);
 362     void (*to_kill) (void);
 363     void (*to_load) (char *, int);
 364     int (*to_lookup_symbol) (char *, CORE_ADDR *);
 365     void (*to_create_inferior) (char *, char *, char **, int);
 366     void (*to_post_startup_inferior) (ptid_t);
 367     void (*to_acknowledge_created_inferior) (int);
 368     void (*to_insert_fork_catchpoint) (int);
 369     int (*to_remove_fork_catchpoint) (int);
 370     void (*to_insert_vfork_catchpoint) (int);
 371     int (*to_remove_vfork_catchpoint) (int);
 372     int (*to_follow_fork) (struct target_ops *, int);
 373     void (*to_insert_exec_catchpoint) (int);
 374     int (*to_remove_exec_catchpoint) (int);
 375     int (*to_reported_exec_events_per_exec_call) (void);
 376     int (*to_has_exited) (int, int, int *);
 377     void (*to_mourn_inferior) (void);
 378     int (*to_can_run) (void);
 379     void (*to_notice_signals) (ptid_t ptid);
 380     int (*to_thread_alive) (ptid_t ptid);
 381     void (*to_find_new_threads) (void);
 382     char *(*to_pid_to_str) (ptid_t);
 383     char *(*to_extra_thread_info) (struct thread_info *);
 384     void (*to_stop) (void);
 385     void (*to_rcmd) (char *command, struct ui_file *output);
 386     struct symtab_and_line *(*to_enable_exception_callback) (enum
 387                                                              exception_event_kind,
 388                                                              int);
 389     struct exception_event_record *(*to_get_current_exception_event) (void);
 390     char *(*to_pid_to_exec_file) (int pid);
 391     enum strata to_stratum;
 392     int to_has_all_memory;
 393     int to_has_memory;
 394     int to_has_stack;
 395     int to_has_registers;
 396     int to_has_execution;
 397     int to_has_thread_control;  /* control thread execution */
 398     struct section_table
 399      *to_sections;
 400     struct section_table
 401      *to_sections_end;
 402     /* ASYNC target controls */
 403     int (*to_can_async_p) (void);
 404     int (*to_is_async_p) (void);
 405     void (*to_async) (void (*cb) (enum inferior_event_type, void *context),
 406                       void *context);
 407     int to_async_mask_value;
 408     int (*to_find_memory_regions) (int (*) (CORE_ADDR,
 409                                             unsigned long,
 410                                             int, int, int,
 411                                             void *),
 412                                    void *);
 413     char * (*to_make_corefile_notes) (bfd *, int *);
 414
 415     /* Return the thread-local address at OFFSET in the
 416        thread-local storage for the thread PTID and the shared library
 417        or executable file given by OBJFILE.  If that block of
 418        thread-local storage hasn't been allocated yet, this function
 419        may return an error.  */
 420     CORE_ADDR (*to_get_thread_local_address) (ptid_t ptid,
 421                                               CORE_ADDR load_module_addr,
 422                                               CORE_ADDR offset);
 423
 424     /* Request that OPS transfer up to LEN 8-bit bytes of the target's
 425        OBJECT.  The OFFSET, for a seekable object, specifies the
 426        starting point.  The ANNEX can be used to provide additional
 427        data-specific information to the target.
 428
 429        Return the number of bytes actually transfered, zero when no
 430        further transfer is possible, and -1 when the transfer is not
 431        supported.  Return of a positive value smaller than LEN does
 432        not indicate the end of the object, only the end of the
 433        transfer; higher level code should continue transferring if
 434        desired.  This is handled in target.c.
 435
 436        The interface does not support a "retry" mechanism.  Instead it
 437        assumes that at least one byte will be transfered on each
 438        successful call.
 439
 440        NOTE: cagney/2003-10-17: The current interface can lead to
 441        fragmented transfers.  Lower target levels should not implement
 442        hacks, such as enlarging the transfer, in an attempt to
 443        compensate for this.  Instead, the target stack should be
 444        extended so that it implements supply/collect methods and a
 445        look-aside object cache.  With that available, the lowest
 446        target can safely and freely "push" data up the stack.
 447
 448        See target_read and target_write for more information.  One,
 449        and only one, of readbuf or writebuf must be non-NULL.  */
 450
 451     LONGEST (*to_xfer_partial) (struct target_ops *ops,
 452                                 enum target_object object, const char *annex,
 453                                 gdb_byte *readbuf, const gdb_byte *writebuf,
 454                                 ULONGEST offset, LONGEST len);
 455
 456     int to_magic;
 457     /* Need sub-structure for target machine related rather than comm related?
 458      */
 459   };
 460
 461 /* Magic number for checking ops size.  If a struct doesn't end with this
 462    number, somebody changed the declaration but didn't change all the
 463    places that initialize one.  */
 464
 465 #define OPS_MAGIC       3840
 466
 467 /* The ops structure for our "current" target process.  This should
 468    never be NULL.  If there is no target, it points to the dummy_target.  */
 469
 470 extern struct target_ops current_target;
 471
 472 /* Define easy words for doing these operations on our current target.  */
 473
 474 #define target_shortname        (current_target.to_shortname)
 475 #define target_longname         (current_target.to_longname)
 476
 477 /* Does whatever cleanup is required for a target that we are no
 478    longer going to be calling.  QUITTING indicates that GDB is exiting
 479    and should not get hung on an error (otherwise it is important to
 480    perform clean termination, even if it takes a while).  This routine
 481    is automatically always called when popping the target off the
 482    target stack (to_beneath is undefined).  Closing file descriptors
 483    and freeing all memory allocated memory are typical things it
 484    should do.  */
 485
 486 void target_close (struct target_ops *targ, int quitting);
 487
 488 /* Attaches to a process on the target side.  Arguments are as passed
 489    to the `attach' command by the user.  This routine can be called
 490    when the target is not on the target-stack, if the target_can_run
 491    routine returns 1; in that case, it must push itself onto the stack.
 492    Upon exit, the target should be ready for normal operations, and
 493    should be ready to deliver the status of the process immediately
 494    (without waiting) to an upcoming target_wait call.  */
 495
 496 #define target_attach(args, from_tty)   \
 497      (*current_target.to_attach) (args, from_tty)
 498
 499 /* The target_attach operation places a process under debugger control,
 500    and stops the process.
 501
 502    This operation provides a target-specific hook that allows the
 503    necessary bookkeeping to be performed after an attach completes.  */
 504 #define target_post_attach(pid) \
 505      (*current_target.to_post_attach) (pid)
 506
 507 /* Takes a program previously attached to and detaches it.
 508    The program may resume execution (some targets do, some don't) and will
 509    no longer stop on signals, etc.  We better not have left any breakpoints
 510    in the program or it'll die when it hits one.  ARGS is arguments
 511    typed by the user (e.g. a signal to send the process).  FROM_TTY
 512    says whether to be verbose or not.  */
 513
 514 extern void target_detach (char *, int);
 515
 516 /* Disconnect from the current target without resuming it (leaving it
 517    waiting for a debugger).  */
 518
 519 extern void target_disconnect (char *, int);
 520
 521 /* Resume execution of the target process PTID.  STEP says whether to
 522    single-step or to run free; SIGGNAL is the signal to be given to
 523    the target, or TARGET_SIGNAL_0 for no signal.  The caller may not
 524    pass TARGET_SIGNAL_DEFAULT.  */
 525
 526 #define target_resume(ptid, step, siggnal)                              \
 527   do {                                                                  \
 528     dcache_invalidate(target_dcache);                                   \
 529     (*current_target.to_resume) (ptid, step, siggnal);                  \
 530   } while (0)
 531
 532 /* Wait for process pid to do something.  PTID = -1 to wait for any
 533    pid to do something.  Return pid of child, or -1 in case of error;
 534    store status through argument pointer STATUS.  Note that it is
 535    _NOT_ OK to throw_exception() out of target_wait() without popping
 536    the debugging target from the stack; GDB isn't prepared to get back
 537    to the prompt with a debugging target but without the frame cache,
 538    stop_pc, etc., set up.  */
 539
 540 #define target_wait(ptid, status)               \
 541      (*current_target.to_wait) (ptid, status)
 542
 543 /* Fetch at least register REGNO, or all regs if regno == -1.  No result.  */
 544
 545 #define target_fetch_registers(regno)   \
 546      (*current_target.to_fetch_registers) (regno)
 547
 548 /* Store at least register REGNO, or all regs if REGNO == -1.
 549    It can store as many registers as it wants to, so target_prepare_to_store
 550    must have been previously called.  Calls error() if there are problems.  */
 551
 552 #define target_store_registers(regs)    \
 553      (*current_target.to_store_registers) (regs)
 554
 555 /* Get ready to modify the registers array.  On machines which store
 556    individual registers, this doesn't need to do anything.  On machines
 557    which store all the registers in one fell swoop, this makes sure
 558    that REGISTERS contains all the registers from the program being
 559    debugged.  */
 560
 561 #define target_prepare_to_store()       \
 562      (*current_target.to_prepare_to_store) ()
 563
 564 extern DCACHE *target_dcache;
 565
 566 extern int target_read_string (CORE_ADDR, char **, int, int *);
 567
 568 extern int target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
 569
 570 extern int target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr,
 571                                 int len);
 572
 573 extern int xfer_memory (CORE_ADDR, gdb_byte *, int, int,
 574                         struct mem_attrib *, struct target_ops *);
 575
 576 extern int child_xfer_memory (CORE_ADDR, gdb_byte *, int, int,
 577                               struct mem_attrib *, struct target_ops *);
 578
 579 extern char *child_pid_to_exec_file (int);
 580
 581 extern char *child_core_file_to_sym_file (char *);
 582
 583 #if defined(CHILD_POST_ATTACH)
 584 extern void child_post_attach (int);
 585 #endif
 586
 587 extern void child_post_startup_inferior (ptid_t);
 588
 589 extern void child_acknowledge_created_inferior (int);
 590
 591 extern void child_insert_fork_catchpoint (int);
 592
 593 extern int child_remove_fork_catchpoint (int);
 594
 595 extern void child_insert_vfork_catchpoint (int);
 596
 597 extern int child_remove_vfork_catchpoint (int);
 598
 599 extern void child_acknowledge_created_inferior (int);
 600
 601 extern int child_follow_fork (struct target_ops *, int);
 602
 603 extern void child_insert_exec_catchpoint (int);
 604
 605 extern int child_remove_exec_catchpoint (int);
 606
 607 extern int child_reported_exec_events_per_exec_call (void);
 608
 609 extern int child_has_exited (int, int, int *);
 610
 611 extern int child_thread_alive (ptid_t);
 612
 613 /* From infrun.c.  */
 614
 615 extern int inferior_has_forked (int pid, int *child_pid);
 616
 617 extern int inferior_has_vforked (int pid, int *child_pid);
 618
 619 extern int inferior_has_execd (int pid, char **execd_pathname);
 620
 621 /* From exec.c */
 622
 623 extern void print_section_info (struct target_ops *, bfd *);
 624
 625 /* Print a line about the current target.  */
 626
 627 #define target_files_info()     \
 628      (*current_target.to_files_info) (&current_target)
 629
 630 /* Insert a breakpoint at address BP_TGT->placed_address in the target
 631    machine.  Result is 0 for success, or an errno value.  */
 632
 633 #define target_insert_breakpoint(bp_tgt)        \
 634      (*current_target.to_insert_breakpoint) (bp_tgt)
 635
 636 /* Remove a breakpoint at address BP_TGT->placed_address in the target
 637    machine.  Result is 0 for success, or an errno value.  */
 638
 639 #define target_remove_breakpoint(bp_tgt)        \
 640      (*current_target.to_remove_breakpoint) (bp_tgt)
 641
 642 /* Initialize the terminal settings we record for the inferior,
 643    before we actually run the inferior.  */
 644
 645 #define target_terminal_init() \
 646      (*current_target.to_terminal_init) ()
 647
 648 /* Put the inferior's terminal settings into effect.
 649    This is preparation for starting or resuming the inferior.  */
 650
 651 #define target_terminal_inferior() \
 652      (*current_target.to_terminal_inferior) ()
 653
 654 /* Put some of our terminal settings into effect,
 655    enough to get proper results from our output,
 656    but do not change into or out of RAW mode
 657    so that no input is discarded.
 658
 659    After doing this, either terminal_ours or terminal_inferior
 660    should be called to get back to a normal state of affairs.  */
 661
 662 #define target_terminal_ours_for_output() \
 663      (*current_target.to_terminal_ours_for_output) ()
 664
 665 /* Put our terminal settings into effect.
 666    First record the inferior's terminal settings
 667    so they can be restored properly later.  */
 668
 669 #define target_terminal_ours() \
 670      (*current_target.to_terminal_ours) ()
 671
 672 /* Save our terminal settings.
 673    This is called from TUI after entering or leaving the curses
 674    mode.  Since curses modifies our terminal this call is here
 675    to take this change into account.  */
 676
 677 #define target_terminal_save_ours() \
 678      (*current_target.to_terminal_save_ours) ()
 679
 680 /* Print useful information about our terminal status, if such a thing
 681    exists.  */
 682
 683 #define target_terminal_info(arg, from_tty) \
 684      (*current_target.to_terminal_info) (arg, from_tty)
 685
 686 /* Kill the inferior process.   Make it go away.  */
 687
 688 #define target_kill() \
 689      (*current_target.to_kill) ()
 690
 691 /* Load an executable file into the target process.  This is expected
 692    to not only bring new code into the target process, but also to
 693    update GDB's symbol tables to match.
 694
 695    ARG contains command-line arguments, to be broken down with
 696    buildargv ().  The first non-switch argument is the filename to
 697    load, FILE; the second is a number (as parsed by strtoul (..., ...,
 698    0)), which is an offset to apply to the load addresses of FILE's
 699    sections.  The target may define switches, or other non-switch
 700    arguments, as it pleases.  */
 701
 702 extern void target_load (char *arg, int from_tty);
 703
 704 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 705    name.  ADDRP is a CORE_ADDR * pointing to where the value of the
 706    symbol should be returned.  The result is 0 if successful, nonzero
 707    if the symbol does not exist in the target environment.  This
 708    function should not call error() if communication with the target
 709    is interrupted, since it is called from symbol reading, but should
 710    return nonzero, possibly doing a complain().  */
 711
 712 #define target_lookup_symbol(name, addrp) \
 713      (*current_target.to_lookup_symbol) (name, addrp)
 714
 715 /* Start an inferior process and set inferior_ptid to its pid.
 716    EXEC_FILE is the file to run.
 717    ALLARGS is a string containing the arguments to the program.
 718    ENV is the environment vector to pass.  Errors reported with error().
 719    On VxWorks and various standalone systems, we ignore exec_file.  */
 720
 721 #define target_create_inferior(exec_file, args, env, FROM_TTY)  \
 722      (*current_target.to_create_inferior) (exec_file, args, env, (FROM_TTY))
 723
 724
 725 /* Some targets (such as ttrace-based HPUX) don't allow us to request
 726    notification of inferior events such as fork and vork immediately
 727    after the inferior is created.  (This because of how gdb gets an
 728    inferior created via invoking a shell to do it.  In such a scenario,
 729    if the shell init file has commands in it, the shell will fork and
 730    exec for each of those commands, and we will see each such fork
 731    event.  Very bad.)
 732
 733    Such targets will supply an appropriate definition for this function.  */
 734
 735 #define target_post_startup_inferior(ptid) \
 736      (*current_target.to_post_startup_inferior) (ptid)
 737
 738 /* On some targets, the sequence of starting up an inferior requires
 739    some synchronization between gdb and the new inferior process, PID.  */
 740
 741 #define target_acknowledge_created_inferior(pid) \
 742      (*current_target.to_acknowledge_created_inferior) (pid)
 743
 744 /* On some targets, we can catch an inferior fork or vfork event when
 745    it occurs.  These functions insert/remove an already-created
 746    catchpoint for such events.  */
 747
 748 #define target_insert_fork_catchpoint(pid) \
 749      (*current_target.to_insert_fork_catchpoint) (pid)
 750
 751 #define target_remove_fork_catchpoint(pid) \
 752      (*current_target.to_remove_fork_catchpoint) (pid)
 753
 754 #define target_insert_vfork_catchpoint(pid) \
 755      (*current_target.to_insert_vfork_catchpoint) (pid)
 756
 757 #define target_remove_vfork_catchpoint(pid) \
 758      (*current_target.to_remove_vfork_catchpoint) (pid)
 759
 760 /* If the inferior forks or vforks, this function will be called at
 761    the next resume in order to perform any bookkeeping and fiddling
 762    necessary to continue debugging either the parent or child, as
 763    requested, and releasing the other.  Information about the fork
 764    or vfork event is available via get_last_target_status ().
 765    This function returns 1 if the inferior should not be resumed
 766    (i.e. there is another event pending).  */
 767
 768 int target_follow_fork (int follow_child);
 769
 770 /* On some targets, we can catch an inferior exec event when it
 771    occurs.  These functions insert/remove an already-created
 772    catchpoint for such events.  */
 773
 774 #define target_insert_exec_catchpoint(pid) \
 775      (*current_target.to_insert_exec_catchpoint) (pid)
 776
 777 #define target_remove_exec_catchpoint(pid) \
 778      (*current_target.to_remove_exec_catchpoint) (pid)
 779
 780 /* Returns the number of exec events that are reported when a process
 781    invokes a flavor of the exec() system call on this target, if exec
 782    events are being reported.  */
 783
 784 #define target_reported_exec_events_per_exec_call() \
 785      (*current_target.to_reported_exec_events_per_exec_call) ()
 786
 787 /* Returns TRUE if PID has exited.  And, also sets EXIT_STATUS to the
 788    exit code of PID, if any.  */
 789
 790 #define target_has_exited(pid,wait_status,exit_status) \
 791      (*current_target.to_has_exited) (pid,wait_status,exit_status)
 792
 793 /* The debugger has completed a blocking wait() call.  There is now
 794    some process event that must be processed.  This function should
 795    be defined by those targets that require the debugger to perform
 796    cleanup or internal state changes in response to the process event.  */
 797
 798 /* The inferior process has died.  Do what is right.  */
 799
 800 #define target_mourn_inferior() \
 801      (*current_target.to_mourn_inferior) ()
 802
 803 /* Does target have enough data to do a run or attach command? */
 804
 805 #define target_can_run(t) \
 806      ((t)->to_can_run) ()
 807
 808 /* post process changes to signal handling in the inferior.  */
 809
 810 #define target_notice_signals(ptid) \
 811      (*current_target.to_notice_signals) (ptid)
 812
 813 /* Check to see if a thread is still alive.  */
 814
 815 #define target_thread_alive(ptid) \
 816      (*current_target.to_thread_alive) (ptid)
 817
 818 /* Query for new threads and add them to the thread list.  */
 819
 820 #define target_find_new_threads() \
 821      (*current_target.to_find_new_threads) (); \
 822
 823 /* Make target stop in a continuable fashion.  (For instance, under
 824    Unix, this should act like SIGSTOP).  This function is normally
 825    used by GUIs to implement a stop button.  */
 826
 827 #define target_stop current_target.to_stop
 828
 829 /* Send the specified COMMAND to the target's monitor
 830    (shell,interpreter) for execution.  The result of the query is
 831    placed in OUTBUF.  */
 832
 833 #define target_rcmd(command, outbuf) \
 834      (*current_target.to_rcmd) (command, outbuf)
 835
 836
 837 /* Get the symbol information for a breakpointable routine called when
 838    an exception event occurs.
 839    Intended mainly for C++, and for those
 840    platforms/implementations where such a callback mechanism is available,
 841    e.g. HP-UX with ANSI C++ (aCC).  Some compilers (e.g. g++) support
 842    different mechanisms for debugging exceptions.  */
 843
 844 #define target_enable_exception_callback(kind, enable) \
 845      (*current_target.to_enable_exception_callback) (kind, enable)
 846
 847 /* Get the current exception event kind -- throw or catch, etc.  */
 848
 849 #define target_get_current_exception_event() \
 850      (*current_target.to_get_current_exception_event) ()
 851
 852 /* Does the target include all of memory, or only part of it?  This
 853    determines whether we look up the target chain for other parts of
 854    memory if this target can't satisfy a request.  */
 855
 856 #define target_has_all_memory   \
 857      (current_target.to_has_all_memory)
 858
 859 /* Does the target include memory?  (Dummy targets don't.)  */
 860
 861 #define target_has_memory       \
 862      (current_target.to_has_memory)
 863
 864 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 865    we start a process.)  */
 866
 867 #define target_has_stack        \
 868      (current_target.to_has_stack)
 869
 870 /* Does the target have registers?  (Exec files don't.)  */
 871
 872 #define target_has_registers    \
 873      (current_target.to_has_registers)
 874
 875 /* Does the target have execution?  Can we make it jump (through
 876    hoops), or pop its stack a few times?  FIXME: If this is to work that
 877    way, it needs to check whether an inferior actually exists.
 878    remote-udi.c and probably other targets can be the current target
 879    when the inferior doesn't actually exist at the moment.  Right now
 880    this just tells us whether this target is *capable* of execution.  */
 881
 882 #define target_has_execution    \
 883      (current_target.to_has_execution)
 884
 885 /* Can the target support the debugger control of thread execution?
 886    a) Can it lock the thread scheduler?
 887    b) Can it switch the currently running thread?  */
 888
 889 #define target_can_lock_scheduler \
 890      (current_target.to_has_thread_control & tc_schedlock)
 891
 892 #define target_can_switch_threads \
 893      (current_target.to_has_thread_control & tc_switch)
 894
 895 /* Can the target support asynchronous execution? */
 896 #define target_can_async_p() (current_target.to_can_async_p ())
 897
 898 /* Is the target in asynchronous execution mode? */
 899 #define target_is_async_p() (current_target.to_is_async_p())
 900
 901 /* Put the target in async mode with the specified callback function. */
 902 #define target_async(CALLBACK,CONTEXT) \
 903      (current_target.to_async((CALLBACK), (CONTEXT)))
 904
 905 /* This is to be used ONLY within call_function_by_hand(). It provides
 906    a workaround, to have inferior function calls done in sychronous
 907    mode, even though the target is asynchronous. After
 908    target_async_mask(0) is called, calls to target_can_async_p() will
 909    return FALSE , so that target_resume() will not try to start the
 910    target asynchronously. After the inferior stops, we IMMEDIATELY
 911    restore the previous nature of the target, by calling
 912    target_async_mask(1). After that, target_can_async_p() will return
 913    TRUE. ANY OTHER USE OF THIS FEATURE IS DEPRECATED.
 914
 915    FIXME ezannoni 1999-12-13: we won't need this once we move
 916    the turning async on and off to the single execution commands,
 917    from where it is done currently, in remote_resume().  */
 918
 919 #define target_async_mask_value \
 920      (current_target.to_async_mask_value)
 921
 922 extern int target_async_mask (int mask);
 923
 924 /* Converts a process id to a string.  Usually, the string just contains
 925    `process xyz', but on some systems it may contain
 926    `process xyz thread abc'.  */
 927
 928 #undef target_pid_to_str
 929 #define target_pid_to_str(PID) current_target.to_pid_to_str (PID)
 930
 931 #ifndef target_tid_to_str
 932 #define target_tid_to_str(PID) \
 933      target_pid_to_str (PID)
 934 extern char *normal_pid_to_str (ptid_t ptid);
 935 #endif
 936
 937 /* Return a short string describing extra information about PID,
 938    e.g. "sleeping", "runnable", "running on LWP 3".  Null return value
 939    is okay.  */
 940
 941 #define target_extra_thread_info(TP) \
 942      (current_target.to_extra_thread_info (TP))
 943
 944 /*
 945  * New Objfile Event Hook:
 946  *
 947  * Sometimes a GDB component wants to get notified whenever a new
 948  * objfile is loaded.  Mainly this is used by thread-debugging
 949  * implementations that need to know when symbols for the target
 950  * thread implemenation are available.
 951  *
 952  * The old way of doing this is to define a macro 'target_new_objfile'
 953  * that points to the function that you want to be called on every
 954  * objfile/shlib load.
 955
 956    The new way is to grab the function pointer,
 957    'deprecated_target_new_objfile_hook', and point it to the function
 958    that you want to be called on every objfile/shlib load.
 959
 960    If multiple clients are willing to be cooperative, they can each
 961    save a pointer to the previous value of
 962    deprecated_target_new_objfile_hook before modifying it, and arrange
 963    for their function to call the previous function in the chain.  In
 964    that way, multiple clients can receive this notification (something
 965    like with signal handlers).  */
 966
 967 extern void (*deprecated_target_new_objfile_hook) (struct objfile *);
 968
 969 #ifndef target_pid_or_tid_to_str
 970 #define target_pid_or_tid_to_str(ID) \
 971      target_pid_to_str (ID)
 972 #endif
 973
 974 /* Attempts to find the pathname of the executable file
 975    that was run to create a specified process.
 976
 977    The process PID must be stopped when this operation is used.
 978
 979    If the executable file cannot be determined, NULL is returned.
 980
 981    Else, a pointer to a character string containing the pathname
 982    is returned.  This string should be copied into a buffer by
 983    the client if the string will not be immediately used, or if
 984    it must persist.  */
 985
 986 #define target_pid_to_exec_file(pid) \
 987      (current_target.to_pid_to_exec_file) (pid)
 988
 989 /*
 990  * Iterator function for target memory regions.
 991  * Calls a callback function once for each memory region 'mapped'
 992  * in the child process.  Defined as a simple macro rather than
 993  * as a function macro so that it can be tested for nullity.
 994  */
 995
 996 #define target_find_memory_regions(FUNC, DATA) \
 997      (current_target.to_find_memory_regions) (FUNC, DATA)
 998
 999 /*
1000  * Compose corefile .note section.
1001  */
1002
1003 #define target_make_corefile_notes(BFD, SIZE_P) \
1004      (current_target.to_make_corefile_notes) (BFD, SIZE_P)
1005
1006 /* Thread-local values.  */
1007 #define target_get_thread_local_address \
1008     (current_target.to_get_thread_local_address)
1009 #define target_get_thread_local_address_p() \
1010     (target_get_thread_local_address != NULL)
1011
1012 /* Hook to call target dependent code just after inferior target process has
1013    started.  */
1014
1015 #ifndef TARGET_CREATE_INFERIOR_HOOK
1016 #define TARGET_CREATE_INFERIOR_HOOK(PID)
1017 #endif
1018
1019 /* Hardware watchpoint interfaces.  */
1020
1021 /* Returns non-zero if we were stopped by a hardware watchpoint (memory read or
1022    write).  */
1023
1024 #ifndef STOPPED_BY_WATCHPOINT
1025 #define STOPPED_BY_WATCHPOINT(w) \
1026    (*current_target.to_stopped_by_watchpoint) ()
1027 #endif
1028
1029 /* Non-zero if we have continuable watchpoints  */
1030
1031 #ifndef HAVE_CONTINUABLE_WATCHPOINT
1032 #define HAVE_CONTINUABLE_WATCHPOINT \
1033    (current_target.to_have_continuable_watchpoint)
1034 #endif
1035
1036 /* Provide defaults for hardware watchpoint functions.  */
1037
1038 /* If the *_hw_beakpoint functions have not been defined
1039    elsewhere use the definitions in the target vector.  */
1040
1041 /* Returns non-zero if we can set a hardware watchpoint of type TYPE.  TYPE is
1042    one of bp_hardware_watchpoint, bp_read_watchpoint, bp_write_watchpoint, or
1043    bp_hardware_breakpoint.  CNT is the number of such watchpoints used so far
1044    (including this one?).  OTHERTYPE is who knows what...  */
1045
1046 #ifndef TARGET_CAN_USE_HARDWARE_WATCHPOINT
1047 #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(TYPE,CNT,OTHERTYPE) \
1048  (*current_target.to_can_use_hw_breakpoint) (TYPE, CNT, OTHERTYPE);
1049 #endif
1050
1051 #ifndef TARGET_REGION_OK_FOR_HW_WATCHPOINT
1052 #define TARGET_REGION_OK_FOR_HW_WATCHPOINT(addr, len) \
1053     (*current_target.to_region_ok_for_hw_watchpoint) (addr, len)
1054 #endif
1055
1056
1057 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.  TYPE is 0
1058    for write, 1 for read, and 2 for read/write accesses.  Returns 0 for
1059    success, non-zero for failure.  */
1060
1061 #ifndef target_insert_watchpoint
1062 #define target_insert_watchpoint(addr, len, type)       \
1063      (*current_target.to_insert_watchpoint) (addr, len, type)
1064
1065 #define target_remove_watchpoint(addr, len, type)       \
1066      (*current_target.to_remove_watchpoint) (addr, len, type)
1067 #endif
1068
1069 #ifndef target_insert_hw_breakpoint
1070 #define target_insert_hw_breakpoint(bp_tgt) \
1071      (*current_target.to_insert_hw_breakpoint) (bp_tgt)
1072
1073 #define target_remove_hw_breakpoint(bp_tgt) \
1074      (*current_target.to_remove_hw_breakpoint) (bp_tgt)
1075 #endif
1076
1077 extern int target_stopped_data_address_p (struct target_ops *);
1078
1079 #ifndef target_stopped_data_address
1080 #define target_stopped_data_address(target, x) \
1081     (*target.to_stopped_data_address) (target, x)
1082 #else
1083 /* Horrible hack to get around existing macros :-(.  */
1084 #define target_stopped_data_address_p(CURRENT_TARGET) (1)
1085 #endif
1086
1087 /* This will only be defined by a target that supports catching vfork events,
1088    such as HP-UX.
1089
1090    On some targets (such as HP-UX 10.20 and earlier), resuming a newly vforked
1091    child process after it has exec'd, causes the parent process to resume as
1092    well.  To prevent the parent from running spontaneously, such targets should
1093    define this to a function that prevents that from happening.  */
1094 #if !defined(ENSURE_VFORKING_PARENT_REMAINS_STOPPED)
1095 #define ENSURE_VFORKING_PARENT_REMAINS_STOPPED(PID) (0)
1096 #endif
1097
1098 /* This will only be defined by a target that supports catching vfork events,
1099    such as HP-UX.
1100
1101    On some targets (such as HP-UX 10.20 and earlier), a newly vforked child
1102    process must be resumed when it delivers its exec event, before the parent
1103    vfork event will be delivered to us.  */
1104
1105 #if !defined(RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK)
1106 #define RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK() (0)
1107 #endif
1108
1109 /* Routines for maintenance of the target structures...
1110
1111    add_target:   Add a target to the list of all possible targets.
1112
1113    push_target:  Make this target the top of the stack of currently used
1114    targets, within its particular stratum of the stack.  Result
1115    is 0 if now atop the stack, nonzero if not on top (maybe
1116    should warn user).
1117
1118    unpush_target: Remove this from the stack of currently used targets,
1119    no matter where it is on the list.  Returns 0 if no
1120    change, 1 if removed from stack.
1121
1122    pop_target:   Remove the top thing on the stack of current targets.  */
1123
1124 extern void add_target (struct target_ops *);
1125
1126 extern int push_target (struct target_ops *);
1127
1128 extern int unpush_target (struct target_ops *);
1129
1130 extern void target_preopen (int);
1131
1132 extern void pop_target (void);
1133
1134 /* Struct section_table maps address ranges to file sections.  It is
1135    mostly used with BFD files, but can be used without (e.g. for handling
1136    raw disks, or files not in formats handled by BFD).  */
1137
1138 struct section_table
1139   {
1140     CORE_ADDR addr;             /* Lowest address in section */
1141     CORE_ADDR endaddr;          /* 1+highest address in section */
1142
1143     struct bfd_section *the_bfd_section;
1144
1145     bfd *bfd;                   /* BFD file pointer */
1146   };
1147
1148 /* Return the "section" containing the specified address.  */
1149 struct section_table *target_section_by_addr (struct target_ops *target,
1150                                               CORE_ADDR addr);
1151
1152
1153 /* From mem-break.c */
1154
1155 extern int memory_remove_breakpoint (struct bp_target_info *);
1156
1157 extern int memory_insert_breakpoint (struct bp_target_info *);
1158
1159 extern int default_memory_remove_breakpoint (struct bp_target_info *);
1160
1161 extern int default_memory_insert_breakpoint (struct bp_target_info *);
1162
1163
1164 /* From target.c */
1165
1166 extern void initialize_targets (void);
1167
1168 extern void noprocess (void);
1169
1170 extern void find_default_attach (char *, int);
1171
1172 extern void find_default_create_inferior (char *, char *, char **, int);
1173
1174 extern struct target_ops *find_run_target (void);
1175
1176 extern struct target_ops *find_core_target (void);
1177
1178 extern struct target_ops *find_target_beneath (struct target_ops *);
1179
1180 extern int target_resize_to_sections (struct target_ops *target,
1181                                       int num_added);
1182
1183 extern void remove_target_sections (bfd *abfd);
1184
1185 \f
1186 /* Stuff that should be shared among the various remote targets.  */
1187
1188 /* Debugging level.  0 is off, and non-zero values mean to print some debug
1189    information (higher values, more information).  */
1190 extern int remote_debug;
1191
1192 /* Speed in bits per second, or -1 which means don't mess with the speed.  */
1193 extern int baud_rate;
1194 /* Timeout limit for response from target. */
1195 extern int remote_timeout;
1196
1197 \f
1198 /* Functions for helping to write a native target.  */
1199
1200 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
1201 extern void store_waitstatus (struct target_waitstatus *, int);
1202
1203 /* Predicate to target_signal_to_host(). Return non-zero if the enum
1204    targ_signal SIGNO has an equivalent ``host'' representation.  */
1205 /* FIXME: cagney/1999-11-22: The name below was chosen in preference
1206    to the shorter target_signal_p() because it is far less ambigious.
1207    In this context ``target_signal'' refers to GDB's internal
1208    representation of the target's set of signals while ``host signal''
1209    refers to the target operating system's signal.  Confused?  */
1210
1211 extern int target_signal_to_host_p (enum target_signal signo);
1212
1213 /* Convert between host signal numbers and enum target_signal's.
1214    target_signal_to_host() returns 0 and prints a warning() on GDB's
1215    console if SIGNO has no equivalent host representation.  */
1216 /* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
1217    refering to the target operating system's signal numbering.
1218    Similarly, ``enum target_signal'' is named incorrectly, ``enum
1219    gdb_signal'' would probably be better as it is refering to GDB's
1220    internal representation of a target operating system's signal.  */
1221
1222 extern enum target_signal target_signal_from_host (int);
1223 extern int target_signal_to_host (enum target_signal);
1224
1225 /* Convert from a number used in a GDB command to an enum target_signal.  */
1226 extern enum target_signal target_signal_from_command (int);
1227
1228 /* Any target can call this to switch to remote protocol (in remote.c). */
1229 extern void push_remote_target (char *name, int from_tty);
1230 \f
1231 /* Imported from machine dependent code */
1232
1233 /* Blank target vector entries are initialized to target_ignore. */
1234 void target_ignore (void);
1235
1236 extern struct target_ops deprecated_child_ops;
1237
1238 #endif /* !defined (TARGET_H) */