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