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