gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2
   3    Copyright (C) 1990-2012 Free Software Foundation, Inc.
   4
   5    Contributed by Cygnus Support.  Written by John Gilmore.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #if !defined (TARGET_H)
  23 #define TARGET_H
  24
  25 struct objfile;
  26 struct ui_file;
  27 struct mem_attrib;
  28 struct target_ops;
  29 struct bp_location;
  30 struct bp_target_info;
  31 struct regcache;
  32 struct target_section_table;
  33 struct trace_state_variable;
  34 struct trace_status;
  35 struct uploaded_tsv;
  36 struct uploaded_tp;
  37 struct static_tracepoint_marker;
  38 struct traceframe_info;
  39 struct expression;
  40
  41 /* This include file defines the interface between the main part
  42    of the debugger, and the part which is target-specific, or
  43    specific to the communications interface between us and the
  44    target.
  45
  46    A TARGET is an interface between the debugger and a particular
  47    kind of file or process.  Targets can be STACKED in STRATA,
  48    so that more than one target can potentially respond to a request.
  49    In particular, memory accesses will walk down the stack of targets
  50    until they find a target that is interested in handling that particular
  51    address.  STRATA are artificial boundaries on the stack, within
  52    which particular kinds of targets live.  Strata exist so that
  53    people don't get confused by pushing e.g. a process target and then
  54    a file target, and wondering why they can't see the current values
  55    of variables any more (the file target is handling them and they
  56    never get to the process target).  So when you push a file target,
  57    it goes into the file stratum, which is always below the process
  58    stratum.  */
  59
  60 #include "bfd.h"
  61 #include "symtab.h"
  62 #include "memattr.h"
  63 #include "vec.h"
  64 #include "gdb_signals.h"
  65
  66 enum strata
  67   {
  68     dummy_stratum,              /* The lowest of the low */
  69     file_stratum,               /* Executable files, etc */
  70     process_stratum,            /* Executing processes or core dump files */
  71     thread_stratum,             /* Executing threads */
  72     record_stratum,             /* Support record debugging */
  73     arch_stratum                /* Architecture overrides */
  74   };
  75
  76 enum thread_control_capabilities
  77   {
  78     tc_none = 0,                /* Default: can't control thread execution.  */
  79     tc_schedlock = 1,           /* Can lock the thread scheduler.  */
  80   };
  81
  82 /* Stuff for target_wait.  */
  83
  84 /* Generally, what has the program done?  */
  85 enum target_waitkind
  86   {
  87     /* The program has exited.  The exit status is in value.integer.  */
  88     TARGET_WAITKIND_EXITED,
  89
  90     /* The program has stopped with a signal.  Which signal is in
  91        value.sig.  */
  92     TARGET_WAITKIND_STOPPED,
  93
  94     /* The program has terminated with a signal.  Which signal is in
  95        value.sig.  */
  96     TARGET_WAITKIND_SIGNALLED,
  97
  98     /* The program is letting us know that it dynamically loaded something
  99        (e.g. it called load(2) on AIX).  */
 100     TARGET_WAITKIND_LOADED,
 101
 102     /* The program has forked.  A "related" process' PTID is in
 103        value.related_pid.  I.e., if the child forks, value.related_pid
 104        is the parent's ID.  */
 105
 106     TARGET_WAITKIND_FORKED,
 107
 108     /* The program has vforked.  A "related" process's PTID is in
 109        value.related_pid.  */
 110
 111     TARGET_WAITKIND_VFORKED,
 112
 113     /* The program has exec'ed a new executable file.  The new file's
 114        pathname is pointed to by value.execd_pathname.  */
 115
 116     TARGET_WAITKIND_EXECD,
 117
 118     /* The program had previously vforked, and now the child is done
 119        with the shared memory region, because it exec'ed or exited.
 120        Note that the event is reported to the vfork parent.  This is
 121        only used if GDB did not stay attached to the vfork child,
 122        otherwise, a TARGET_WAITKIND_EXECD or
 123        TARGET_WAITKIND_EXIT|SIGNALLED event associated with the child
 124        has the same effect.  */
 125     TARGET_WAITKIND_VFORK_DONE,
 126
 127     /* The program has entered or returned from a system call.  On
 128        HP-UX, this is used in the hardware watchpoint implementation.
 129        The syscall's unique integer ID number is in value.syscall_id.  */
 130
 131     TARGET_WAITKIND_SYSCALL_ENTRY,
 132     TARGET_WAITKIND_SYSCALL_RETURN,
 133
 134     /* Nothing happened, but we stopped anyway.  This perhaps should be handled
 135        within target_wait, but I'm not sure target_wait should be resuming the
 136        inferior.  */
 137     TARGET_WAITKIND_SPURIOUS,
 138
 139     /* An event has occured, but we should wait again.
 140        Remote_async_wait() returns this when there is an event
 141        on the inferior, but the rest of the world is not interested in
 142        it.  The inferior has not stopped, but has just sent some output
 143        to the console, for instance.  In this case, we want to go back
 144        to the event loop and wait there for another event from the
 145        inferior, rather than being stuck in the remote_async_wait()
 146        function. sThis way the event loop is responsive to other events,
 147        like for instance the user typing.  */
 148     TARGET_WAITKIND_IGNORE,
 149
 150     /* The target has run out of history information,
 151        and cannot run backward any further.  */
 152     TARGET_WAITKIND_NO_HISTORY,
 153
 154     /* There are no resumed children left in the program.  */
 155     TARGET_WAITKIND_NO_RESUMED
 156   };
 157
 158 struct target_waitstatus
 159   {
 160     enum target_waitkind kind;
 161
 162     /* Forked child pid, execd pathname, exit status, signal number or
 163        syscall number.  */
 164     union
 165       {
 166         int integer;
 167         enum target_signal sig;
 168         ptid_t related_pid;
 169         char *execd_pathname;
 170         int syscall_number;
 171       }
 172     value;
 173   };
 174
 175 /* Options that can be passed to target_wait.  */
 176
 177 /* Return immediately if there's no event already queued.  If this
 178    options is not requested, target_wait blocks waiting for an
 179    event.  */
 180 #define TARGET_WNOHANG 1
 181
 182 /* The structure below stores information about a system call.
 183    It is basically used in the "catch syscall" command, and in
 184    every function that gives information about a system call.
 185
 186    It's also good to mention that its fields represent everything
 187    that we currently know about a syscall in GDB.  */
 188 struct syscall
 189   {
 190     /* The syscall number.  */
 191     int number;
 192
 193     /* The syscall name.  */
 194     const char *name;
 195   };
 196
 197 /* Return a pretty printed form of target_waitstatus.
 198    Space for the result is malloc'd, caller must free.  */
 199 extern char *target_waitstatus_to_string (const struct target_waitstatus *);
 200
 201 /* Possible types of events that the inferior handler will have to
 202    deal with.  */
 203 enum inferior_event_type
 204   {
 205     /* Process a normal inferior event which will result in target_wait
 206        being called.  */
 207     INF_REG_EVENT,
 208     /* We are called because a timer went off.  */
 209     INF_TIMER,
 210     /* We are called to do stuff after the inferior stops.  */
 211     INF_EXEC_COMPLETE,
 212     /* We are called to do some stuff after the inferior stops, but we
 213        are expected to reenter the proceed() and
 214        handle_inferior_event() functions.  This is used only in case of
 215        'step n' like commands.  */
 216     INF_EXEC_CONTINUE
 217   };
 218 \f
 219 /* Target objects which can be transfered using target_read,
 220    target_write, et cetera.  */
 221
 222 enum target_object
 223 {
 224   /* AVR target specific transfer.  See "avr-tdep.c" and "remote.c".  */
 225   TARGET_OBJECT_AVR,
 226   /* SPU target specific transfer.  See "spu-tdep.c".  */
 227   TARGET_OBJECT_SPU,
 228   /* Transfer up-to LEN bytes of memory starting at OFFSET.  */
 229   TARGET_OBJECT_MEMORY,
 230   /* Memory, avoiding GDB's data cache and trusting the executable.
 231      Target implementations of to_xfer_partial never need to handle
 232      this object, and most callers should not use it.  */
 233   TARGET_OBJECT_RAW_MEMORY,
 234   /* Memory known to be part of the target's stack.  This is cached even
 235      if it is not in a region marked as such, since it is known to be
 236      "normal" RAM.  */
 237   TARGET_OBJECT_STACK_MEMORY,
 238   /* Kernel Unwind Table.  See "ia64-tdep.c".  */
 239   TARGET_OBJECT_UNWIND_TABLE,
 240   /* Transfer auxilliary vector.  */
 241   TARGET_OBJECT_AUXV,
 242   /* StackGhost cookie.  See "sparc-tdep.c".  */
 243   TARGET_OBJECT_WCOOKIE,
 244   /* Target memory map in XML format.  */
 245   TARGET_OBJECT_MEMORY_MAP,
 246   /* Flash memory.  This object can be used to write contents to
 247      a previously erased flash memory.  Using it without erasing
 248      flash can have unexpected results.  Addresses are physical
 249      address on target, and not relative to flash start.  */
 250   TARGET_OBJECT_FLASH,
 251   /* Available target-specific features, e.g. registers and coprocessors.
 252      See "target-descriptions.c".  ANNEX should never be empty.  */
 253   TARGET_OBJECT_AVAILABLE_FEATURES,
 254   /* Currently loaded libraries, in XML format.  */
 255   TARGET_OBJECT_LIBRARIES,
 256   /* Currently loaded libraries specific for SVR4 systems, in XML format.  */
 257   TARGET_OBJECT_LIBRARIES_SVR4,
 258   /* Get OS specific data.  The ANNEX specifies the type (running
 259      processes, etc.).  The data being transfered is expected to follow
 260      the DTD specified in features/osdata.dtd.  */
 261   TARGET_OBJECT_OSDATA,
 262   /* Extra signal info.  Usually the contents of `siginfo_t' on unix
 263      platforms.  */
 264   TARGET_OBJECT_SIGNAL_INFO,
 265   /* The list of threads that are being debugged.  */
 266   TARGET_OBJECT_THREADS,
 267   /* Collected static trace data.  */
 268   TARGET_OBJECT_STATIC_TRACE_DATA,
 269   /* The HP-UX registers (those that can be obtained or modified by using
 270      the TT_LWP_RUREGS/TT_LWP_WUREGS ttrace requests).  */
 271   TARGET_OBJECT_HPUX_UREGS,
 272   /* The HP-UX shared library linkage pointer.  ANNEX should be a string
 273      image of the code address whose linkage pointer we are looking for.
 274
 275      The size of the data transfered is always 8 bytes (the size of an
 276      address on ia64).  */
 277   TARGET_OBJECT_HPUX_SOLIB_GOT,
 278   /* Traceframe info, in XML format.  */
 279   TARGET_OBJECT_TRACEFRAME_INFO,
 280   /* Load maps for FDPIC systems.  */
 281   TARGET_OBJECT_FDPIC,
 282   /* Darwin dynamic linker info data.  */
 283   TARGET_OBJECT_DARWIN_DYLD_INFO,
 284   /* OpenVMS Unwind Information Block.  */
 285   TARGET_OBJECT_OPENVMS_UIB
 286   /* Possible future objects: TARGET_OBJECT_FILE, ...  */
 287 };
 288
 289 /* Enumeration of the kinds of traceframe searches that a target may
 290    be able to perform.  */
 291
 292 enum trace_find_type
 293   {
 294     tfind_number,
 295     tfind_pc,
 296     tfind_tp,
 297     tfind_range,
 298     tfind_outside,
 299   };
 300
 301 typedef struct static_tracepoint_marker *static_tracepoint_marker_p;
 302 DEF_VEC_P(static_tracepoint_marker_p);
 303
 304 /* Request that OPS transfer up to LEN 8-bit bytes of the target's
 305    OBJECT.  The OFFSET, for a seekable object, specifies the
 306    starting point.  The ANNEX can be used to provide additional
 307    data-specific information to the target.
 308
 309    Return the number of bytes actually transfered, or -1 if the
 310    transfer is not supported or otherwise fails.  Return of a positive
 311    value less than LEN indicates that no further transfer is possible.
 312    Unlike the raw to_xfer_partial interface, callers of these
 313    functions do not need to retry partial transfers.  */
 314
 315 extern LONGEST target_read (struct target_ops *ops,
 316                             enum target_object object,
 317                             const char *annex, gdb_byte *buf,
 318                             ULONGEST offset, LONGEST len);
 319
 320 struct memory_read_result
 321   {
 322     /* First address that was read.  */
 323     ULONGEST begin;
 324     /* Past-the-end address.  */
 325     ULONGEST end;
 326     /* The data.  */
 327     gdb_byte *data;
 328 };
 329 typedef struct memory_read_result memory_read_result_s;
 330 DEF_VEC_O(memory_read_result_s);
 331
 332 extern void free_memory_read_result_vector (void *);
 333
 334 extern VEC(memory_read_result_s)* read_memory_robust (struct target_ops *ops,
 335                                                       ULONGEST offset,
 336                                                       LONGEST len);
 337
 338 extern LONGEST target_write (struct target_ops *ops,
 339                              enum target_object object,
 340                              const char *annex, const gdb_byte *buf,
 341                              ULONGEST offset, LONGEST len);
 342
 343 /* Similar to target_write, except that it also calls PROGRESS with
 344    the number of bytes written and the opaque BATON after every
 345    successful partial write (and before the first write).  This is
 346    useful for progress reporting and user interaction while writing
 347    data.  To abort the transfer, the progress callback can throw an
 348    exception.  */
 349
 350 LONGEST target_write_with_progress (struct target_ops *ops,
 351                                     enum target_object object,
 352                                     const char *annex, const gdb_byte *buf,
 353                                     ULONGEST offset, LONGEST len,
 354                                     void (*progress) (ULONGEST, void *),
 355                                     void *baton);
 356
 357 /* Wrapper to perform a full read of unknown size.  OBJECT/ANNEX will
 358    be read using OPS.  The return value will be -1 if the transfer
 359    fails or is not supported; 0 if the object is empty; or the length
 360    of the object otherwise.  If a positive value is returned, a
 361    sufficiently large buffer will be allocated using xmalloc and
 362    returned in *BUF_P containing the contents of the object.
 363
 364    This method should be used for objects sufficiently small to store
 365    in a single xmalloc'd buffer, when no fixed bound on the object's
 366    size is known in advance.  Don't try to read TARGET_OBJECT_MEMORY
 367    through this function.  */
 368
 369 extern LONGEST target_read_alloc (struct target_ops *ops,
 370                                   enum target_object object,
 371                                   const char *annex, gdb_byte **buf_p);
 372
 373 /* Read OBJECT/ANNEX using OPS.  The result is NUL-terminated and
 374    returned as a string, allocated using xmalloc.  If an error occurs
 375    or the transfer is unsupported, NULL is returned.  Empty objects
 376    are returned as allocated but empty strings.  A warning is issued
 377    if the result contains any embedded NUL bytes.  */
 378
 379 extern char *target_read_stralloc (struct target_ops *ops,
 380                                    enum target_object object,
 381                                    const char *annex);
 382
 383 /* Wrappers to target read/write that perform memory transfers.  They
 384    throw an error if the memory transfer fails.
 385
 386    NOTE: cagney/2003-10-23: The naming schema is lifted from
 387    "frame.h".  The parameter order is lifted from get_frame_memory,
 388    which in turn lifted it from read_memory.  */
 389
 390 extern void get_target_memory (struct target_ops *ops, CORE_ADDR addr,
 391                                gdb_byte *buf, LONGEST len);
 392 extern ULONGEST get_target_memory_unsigned (struct target_ops *ops,
 393                                             CORE_ADDR addr, int len,
 394                                             enum bfd_endian byte_order);
 395 \f
 396 struct thread_info;             /* fwd decl for parameter list below: */
 397
 398 struct target_ops
 399   {
 400     struct target_ops *beneath; /* To the target under this one.  */
 401     char *to_shortname;         /* Name this target type */
 402     char *to_longname;          /* Name for printing */
 403     char *to_doc;               /* Documentation.  Does not include trailing
 404                                    newline, and starts with a one-line descrip-
 405                                    tion (probably similar to to_longname).  */
 406     /* Per-target scratch pad.  */
 407     void *to_data;
 408     /* The open routine takes the rest of the parameters from the
 409        command, and (if successful) pushes a new target onto the
 410        stack.  Targets should supply this routine, if only to provide
 411        an error message.  */
 412     void (*to_open) (char *, int);
 413     /* Old targets with a static target vector provide "to_close".
 414        New re-entrant targets provide "to_xclose" and that is expected
 415        to xfree everything (including the "struct target_ops").  */
 416     void (*to_xclose) (struct target_ops *targ, int quitting);
 417     void (*to_close) (int);
 418     void (*to_attach) (struct target_ops *ops, char *, int);
 419     void (*to_post_attach) (int);
 420     void (*to_detach) (struct target_ops *ops, char *, int);
 421     void (*to_disconnect) (struct target_ops *, char *, int);
 422     void (*to_resume) (struct target_ops *, ptid_t, int, enum target_signal);
 423     ptid_t (*to_wait) (struct target_ops *,
 424                        ptid_t, struct target_waitstatus *, int);
 425     void (*to_fetch_registers) (struct target_ops *, struct regcache *, int);
 426     void (*to_store_registers) (struct target_ops *, struct regcache *, int);
 427     void (*to_prepare_to_store) (struct regcache *);
 428
 429     /* Transfer LEN bytes of memory between GDB address MYADDR and
 430        target address MEMADDR.  If WRITE, transfer them to the target, else
 431        transfer them from the target.  TARGET is the target from which we
 432        get this function.
 433
 434        Return value, N, is one of the following:
 435
 436        0 means that we can't handle this.  If errno has been set, it is the
 437        error which prevented us from doing it (FIXME: What about bfd_error?).
 438
 439        positive (call it N) means that we have transferred N bytes
 440        starting at MEMADDR.  We might be able to handle more bytes
 441        beyond this length, but no promises.
 442
 443        negative (call its absolute value N) means that we cannot
 444        transfer right at MEMADDR, but we could transfer at least
 445        something at MEMADDR + N.
 446
 447        NOTE: cagney/2004-10-01: This has been entirely superseeded by
 448        to_xfer_partial and inferior inheritance.  */
 449
 450     int (*deprecated_xfer_memory) (CORE_ADDR memaddr, gdb_byte *myaddr,
 451                                    int len, int write,
 452                                    struct mem_attrib *attrib,
 453                                    struct target_ops *target);
 454
 455     void (*to_files_info) (struct target_ops *);
 456     int (*to_insert_breakpoint) (struct gdbarch *, struct bp_target_info *);
 457     int (*to_remove_breakpoint) (struct gdbarch *, struct bp_target_info *);
 458     int (*to_can_use_hw_breakpoint) (int, int, int);
 459     int (*to_ranged_break_num_registers) (struct target_ops *);
 460     int (*to_insert_hw_breakpoint) (struct gdbarch *, struct bp_target_info *);
 461     int (*to_remove_hw_breakpoint) (struct gdbarch *, struct bp_target_info *);
 462
 463     /* Documentation of what the two routines below are expected to do is
 464        provided with the corresponding target_* macros.  */
 465     int (*to_remove_watchpoint) (CORE_ADDR, int, int, struct expression *);
 466     int (*to_insert_watchpoint) (CORE_ADDR, int, int, struct expression *);
 467
 468     int (*to_insert_mask_watchpoint) (struct target_ops *,
 469                                       CORE_ADDR, CORE_ADDR, int);
 470     int (*to_remove_mask_watchpoint) (struct target_ops *,
 471                                       CORE_ADDR, CORE_ADDR, int);
 472     int (*to_stopped_by_watchpoint) (void);
 473     int to_have_steppable_watchpoint;
 474     int to_have_continuable_watchpoint;
 475     int (*to_stopped_data_address) (struct target_ops *, CORE_ADDR *);
 476     int (*to_watchpoint_addr_within_range) (struct target_ops *,
 477                                             CORE_ADDR, CORE_ADDR, int);
 478
 479     /* Documentation of this routine is provided with the corresponding
 480        target_* macro.  */
 481     int (*to_region_ok_for_hw_watchpoint) (CORE_ADDR, int);
 482
 483     int (*to_can_accel_watchpoint_condition) (CORE_ADDR, int, int,
 484                                               struct expression *);
 485     int (*to_masked_watch_num_registers) (struct target_ops *,
 486                                           CORE_ADDR, CORE_ADDR);
 487     void (*to_terminal_init) (void);
 488     void (*to_terminal_inferior) (void);
 489     void (*to_terminal_ours_for_output) (void);
 490     void (*to_terminal_ours) (void);
 491     void (*to_terminal_save_ours) (void);
 492     void (*to_terminal_info) (char *, int);
 493     void (*to_kill) (struct target_ops *);
 494     void (*to_load) (char *, int);
 495     void (*to_create_inferior) (struct target_ops *,
 496                                 char *, char *, char **, int);
 497     void (*to_post_startup_inferior) (ptid_t);
 498     int (*to_insert_fork_catchpoint) (int);
 499     int (*to_remove_fork_catchpoint) (int);
 500     int (*to_insert_vfork_catchpoint) (int);
 501     int (*to_remove_vfork_catchpoint) (int);
 502     int (*to_follow_fork) (struct target_ops *, int);
 503     int (*to_insert_exec_catchpoint) (int);
 504     int (*to_remove_exec_catchpoint) (int);
 505     int (*to_set_syscall_catchpoint) (int, int, int, int, int *);
 506     int (*to_has_exited) (int, int, int *);
 507     void (*to_mourn_inferior) (struct target_ops *);
 508     int (*to_can_run) (void);
 509
 510     /* Documentation of this routine is provided with the corresponding
 511        target_* macro.  */
 512     void (*to_pass_signals) (int, unsigned char *);
 513
 514     int (*to_thread_alive) (struct target_ops *, ptid_t ptid);
 515     void (*to_find_new_threads) (struct target_ops *);
 516     char *(*to_pid_to_str) (struct target_ops *, ptid_t);
 517     char *(*to_extra_thread_info) (struct thread_info *);
 518     char *(*to_thread_name) (struct thread_info *);
 519     void (*to_stop) (ptid_t);
 520     void (*to_rcmd) (char *command, struct ui_file *output);
 521     char *(*to_pid_to_exec_file) (int pid);
 522     void (*to_log_command) (const char *);
 523     struct target_section_table *(*to_get_section_table) (struct target_ops *);
 524     enum strata to_stratum;
 525     int (*to_has_all_memory) (struct target_ops *);
 526     int (*to_has_memory) (struct target_ops *);
 527     int (*to_has_stack) (struct target_ops *);
 528     int (*to_has_registers) (struct target_ops *);
 529     int (*to_has_execution) (struct target_ops *, ptid_t);
 530     int to_has_thread_control;  /* control thread execution */
 531     int to_attach_no_wait;
 532     /* ASYNC target controls */
 533     int (*to_can_async_p) (void);
 534     int (*to_is_async_p) (void);
 535     void (*to_async) (void (*) (enum inferior_event_type, void *), void *);
 536     int (*to_supports_non_stop) (void);
 537     /* find_memory_regions support method for gcore */
 538     int (*to_find_memory_regions) (find_memory_region_ftype func, void *data);
 539     /* make_corefile_notes support method for gcore */
 540     char * (*to_make_corefile_notes) (bfd *, int *);
 541     /* get_bookmark support method for bookmarks */
 542     gdb_byte * (*to_get_bookmark) (char *, int);
 543     /* goto_bookmark support method for bookmarks */
 544     void (*to_goto_bookmark) (gdb_byte *, int);
 545     /* Return the thread-local address at OFFSET in the
 546        thread-local storage for the thread PTID and the shared library
 547        or executable file given by OBJFILE.  If that block of
 548        thread-local storage hasn't been allocated yet, this function
 549        may return an error.  */
 550     CORE_ADDR (*to_get_thread_local_address) (struct target_ops *ops,
 551                                               ptid_t ptid,
 552                                               CORE_ADDR load_module_addr,
 553                                               CORE_ADDR offset);
 554
 555     /* Request that OPS transfer up to LEN 8-bit bytes of the target's
 556        OBJECT.  The OFFSET, for a seekable object, specifies the
 557        starting point.  The ANNEX can be used to provide additional
 558        data-specific information to the target.
 559
 560        Return the number of bytes actually transfered, zero when no
 561        further transfer is possible, and -1 when the transfer is not
 562        supported.  Return of a positive value smaller than LEN does
 563        not indicate the end of the object, only the end of the
 564        transfer; higher level code should continue transferring if
 565        desired.  This is handled in target.c.
 566
 567        The interface does not support a "retry" mechanism.  Instead it
 568        assumes that at least one byte will be transfered on each
 569        successful call.
 570
 571        NOTE: cagney/2003-10-17: The current interface can lead to
 572        fragmented transfers.  Lower target levels should not implement
 573        hacks, such as enlarging the transfer, in an attempt to
 574        compensate for this.  Instead, the target stack should be
 575        extended so that it implements supply/collect methods and a
 576        look-aside object cache.  With that available, the lowest
 577        target can safely and freely "push" data up the stack.
 578
 579        See target_read and target_write for more information.  One,
 580        and only one, of readbuf or writebuf must be non-NULL.  */
 581
 582     LONGEST (*to_xfer_partial) (struct target_ops *ops,
 583                                 enum target_object object, const char *annex,
 584                                 gdb_byte *readbuf, const gdb_byte *writebuf,
 585                                 ULONGEST offset, LONGEST len);
 586
 587     /* Returns the memory map for the target.  A return value of NULL
 588        means that no memory map is available.  If a memory address
 589        does not fall within any returned regions, it's assumed to be
 590        RAM.  The returned memory regions should not overlap.
 591
 592        The order of regions does not matter; target_memory_map will
 593        sort regions by starting address.  For that reason, this
 594        function should not be called directly except via
 595        target_memory_map.
 596
 597        This method should not cache data; if the memory map could
 598        change unexpectedly, it should be invalidated, and higher
 599        layers will re-fetch it.  */
 600     VEC(mem_region_s) *(*to_memory_map) (struct target_ops *);
 601
 602     /* Erases the region of flash memory starting at ADDRESS, of
 603        length LENGTH.
 604
 605        Precondition: both ADDRESS and ADDRESS+LENGTH should be aligned
 606        on flash block boundaries, as reported by 'to_memory_map'.  */
 607     void (*to_flash_erase) (struct target_ops *,
 608                            ULONGEST address, LONGEST length);
 609
 610     /* Finishes a flash memory write sequence.  After this operation
 611        all flash memory should be available for writing and the result
 612        of reading from areas written by 'to_flash_write' should be
 613        equal to what was written.  */
 614     void (*to_flash_done) (struct target_ops *);
 615
 616     /* Describe the architecture-specific features of this target.
 617        Returns the description found, or NULL if no description
 618        was available.  */
 619     const struct target_desc *(*to_read_description) (struct target_ops *ops);
 620
 621     /* Build the PTID of the thread on which a given task is running,
 622        based on LWP and THREAD.  These values are extracted from the
 623        task Private_Data section of the Ada Task Control Block, and
 624        their interpretation depends on the target.  */
 625     ptid_t (*to_get_ada_task_ptid) (long lwp, long thread);
 626
 627     /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
 628        Return 0 if *READPTR is already at the end of the buffer.
 629        Return -1 if there is insufficient buffer for a whole entry.
 630        Return 1 if an entry was read into *TYPEP and *VALP.  */
 631     int (*to_auxv_parse) (struct target_ops *ops, gdb_byte **readptr,
 632                          gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp);
 633
 634     /* Search SEARCH_SPACE_LEN bytes beginning at START_ADDR for the
 635        sequence of bytes in PATTERN with length PATTERN_LEN.
 636
 637        The result is 1 if found, 0 if not found, and -1 if there was an error
 638        requiring halting of the search (e.g. memory read error).
 639        If the pattern is found the address is recorded in FOUND_ADDRP.  */
 640     int (*to_search_memory) (struct target_ops *ops,
 641                              CORE_ADDR start_addr, ULONGEST search_space_len,
 642                              const gdb_byte *pattern, ULONGEST pattern_len,
 643                              CORE_ADDR *found_addrp);
 644
 645     /* Can target execute in reverse?  */
 646     int (*to_can_execute_reverse) (void);
 647
 648     /* The direction the target is currently executing.  Must be
 649        implemented on targets that support reverse execution and async
 650        mode.  The default simply returns forward execution.  */
 651     enum exec_direction_kind (*to_execution_direction) (void);
 652
 653     /* Does this target support debugging multiple processes
 654        simultaneously?  */
 655     int (*to_supports_multi_process) (void);
 656
 657     /* Does this target support enabling and disabling tracepoints while a trace
 658        experiment is running?  */
 659     int (*to_supports_enable_disable_tracepoint) (void);
 660
 661     /* Does this target support disabling address space randomization?  */
 662     int (*to_supports_disable_randomization) (void);
 663
 664     /* Does this target support the tracenz bytecode for string collection?  */
 665     int (*to_supports_string_tracing) (void);
 666
 667     /* Does this target support evaluation of breakpoint conditions on its
 668        end?  */
 669     int (*to_supports_evaluation_of_breakpoint_conditions) (void);
 670
 671     /* Determine current architecture of thread PTID.
 672
 673        The target is supposed to determine the architecture of the code where
 674        the target is currently stopped at (on Cell, if a target is in spu_run,
 675        to_thread_architecture would return SPU, otherwise PPC32 or PPC64).
 676        This is architecture used to perform decr_pc_after_break adjustment,
 677        and also determines the frame architecture of the innermost frame.
 678        ptrace operations need to operate according to target_gdbarch.
 679
 680        The default implementation always returns target_gdbarch.  */
 681     struct gdbarch *(*to_thread_architecture) (struct target_ops *, ptid_t);
 682
 683     /* Determine current address space of thread PTID.
 684
 685        The default implementation always returns the inferior's
 686        address space.  */
 687     struct address_space *(*to_thread_address_space) (struct target_ops *,
 688                                                       ptid_t);
 689
 690     /* Target file operations.  */
 691
 692     /* Open FILENAME on the target, using FLAGS and MODE.  Return a
 693        target file descriptor, or -1 if an error occurs (and set
 694        *TARGET_ERRNO).  */
 695     int (*to_fileio_open) (const char *filename, int flags, int mode,
 696                            int *target_errno);
 697
 698     /* Write up to LEN bytes from WRITE_BUF to FD on the target.
 699        Return the number of bytes written, or -1 if an error occurs
 700        (and set *TARGET_ERRNO).  */
 701     int (*to_fileio_pwrite) (int fd, const gdb_byte *write_buf, int len,
 702                              ULONGEST offset, int *target_errno);
 703
 704     /* Read up to LEN bytes FD on the target into READ_BUF.
 705        Return the number of bytes read, or -1 if an error occurs
 706        (and set *TARGET_ERRNO).  */
 707     int (*to_fileio_pread) (int fd, gdb_byte *read_buf, int len,
 708                             ULONGEST offset, int *target_errno);
 709
 710     /* Close FD on the target.  Return 0, or -1 if an error occurs
 711        (and set *TARGET_ERRNO).  */
 712     int (*to_fileio_close) (int fd, int *target_errno);
 713
 714     /* Unlink FILENAME on the target.  Return 0, or -1 if an error
 715        occurs (and set *TARGET_ERRNO).  */
 716     int (*to_fileio_unlink) (const char *filename, int *target_errno);
 717
 718     /* Read value of symbolic link FILENAME on the target.  Return a
 719        null-terminated string allocated via xmalloc, or NULL if an error
 720        occurs (and set *TARGET_ERRNO).  */
 721     char *(*to_fileio_readlink) (const char *filename, int *target_errno);
 722
 723
 724     /* Implement the "info proc" command.  */
 725     void (*to_info_proc) (struct target_ops *, char *, enum info_proc_what);
 726
 727     /* Tracepoint-related operations.  */
 728
 729     /* Prepare the target for a tracing run.  */
 730     void (*to_trace_init) (void);
 731
 732     /* Send full details of a tracepoint location to the target.  */
 733     void (*to_download_tracepoint) (struct bp_location *location);
 734
 735     /* Is the target able to download tracepoint locations in current
 736        state?  */
 737     int (*to_can_download_tracepoint) (void);
 738
 739     /* Send full details of a trace state variable to the target.  */
 740     void (*to_download_trace_state_variable) (struct trace_state_variable *tsv);
 741
 742     /* Enable a tracepoint on the target.  */
 743     void (*to_enable_tracepoint) (struct bp_location *location);
 744
 745     /* Disable a tracepoint on the target.  */
 746     void (*to_disable_tracepoint) (struct bp_location *location);
 747
 748     /* Inform the target info of memory regions that are readonly
 749        (such as text sections), and so it should return data from
 750        those rather than look in the trace buffer.  */
 751     void (*to_trace_set_readonly_regions) (void);
 752
 753     /* Start a trace run.  */
 754     void (*to_trace_start) (void);
 755
 756     /* Get the current status of a tracing run.  */
 757     int (*to_get_trace_status) (struct trace_status *ts);
 758
 759     void (*to_get_tracepoint_status) (struct breakpoint *tp,
 760                                       struct uploaded_tp *utp);
 761
 762     /* Stop a trace run.  */
 763     void (*to_trace_stop) (void);
 764
 765    /* Ask the target to find a trace frame of the given type TYPE,
 766       using NUM, ADDR1, and ADDR2 as search parameters.  Returns the
 767       number of the trace frame, and also the tracepoint number at
 768       TPP.  If no trace frame matches, return -1.  May throw if the
 769       operation fails.  */
 770     int (*to_trace_find) (enum trace_find_type type, int num,
 771                           ULONGEST addr1, ULONGEST addr2, int *tpp);
 772
 773     /* Get the value of the trace state variable number TSV, returning
 774        1 if the value is known and writing the value itself into the
 775        location pointed to by VAL, else returning 0.  */
 776     int (*to_get_trace_state_variable_value) (int tsv, LONGEST *val);
 777
 778     int (*to_save_trace_data) (const char *filename);
 779
 780     int (*to_upload_tracepoints) (struct uploaded_tp **utpp);
 781
 782     int (*to_upload_trace_state_variables) (struct uploaded_tsv **utsvp);
 783
 784     LONGEST (*to_get_raw_trace_data) (gdb_byte *buf,
 785                                       ULONGEST offset, LONGEST len);
 786
 787     /* Get the minimum length of instruction on which a fast tracepoint
 788        may be set on the target.  If this operation is unsupported,
 789        return -1.  If for some reason the minimum length cannot be
 790        determined, return 0.  */
 791     int (*to_get_min_fast_tracepoint_insn_len) (void);
 792
 793     /* Set the target's tracing behavior in response to unexpected
 794        disconnection - set VAL to 1 to keep tracing, 0 to stop.  */
 795     void (*to_set_disconnected_tracing) (int val);
 796     void (*to_set_circular_trace_buffer) (int val);
 797
 798     /* Add/change textual notes about the trace run, returning 1 if
 799        successful, 0 otherwise.  */
 800     int (*to_set_trace_notes) (char *user, char *notes, char* stopnotes);
 801
 802     /* Return the processor core that thread PTID was last seen on.
 803        This information is updated only when:
 804        - update_thread_list is called
 805        - thread stops
 806        If the core cannot be determined -- either for the specified
 807        thread, or right now, or in this debug session, or for this
 808        target -- return -1.  */
 809     int (*to_core_of_thread) (struct target_ops *, ptid_t ptid);
 810
 811     /* Verify that the memory in the [MEMADDR, MEMADDR+SIZE) range
 812        matches the contents of [DATA,DATA+SIZE).  Returns 1 if there's
 813        a match, 0 if there's a mismatch, and -1 if an error is
 814        encountered while reading memory.  */
 815     int (*to_verify_memory) (struct target_ops *, const gdb_byte *data,
 816                              CORE_ADDR memaddr, ULONGEST size);
 817
 818     /* Return the address of the start of the Thread Information Block
 819        a Windows OS specific feature.  */
 820     int (*to_get_tib_address) (ptid_t ptid, CORE_ADDR *addr);
 821
 822     /* Send the new settings of write permission variables.  */
 823     void (*to_set_permissions) (void);
 824
 825     /* Look for a static tracepoint marker at ADDR, and fill in MARKER
 826        with its details.  Return 1 on success, 0 on failure.  */
 827     int (*to_static_tracepoint_marker_at) (CORE_ADDR,
 828                                            struct static_tracepoint_marker *marker);
 829
 830     /* Return a vector of all tracepoints markers string id ID, or all
 831        markers if ID is NULL.  */
 832     VEC(static_tracepoint_marker_p) *(*to_static_tracepoint_markers_by_strid)
 833       (const char *id);
 834
 835     /* Return a traceframe info object describing the current
 836        traceframe's contents.  This method should not cache data;
 837        higher layers take care of caching, invalidating, and
 838        re-fetching when necessary.  */
 839     struct traceframe_info *(*to_traceframe_info) (void);
 840
 841     /* Ask the target to use or not to use agent according to USE.  Return 1
 842        successful, 0 otherwise.  */
 843     int (*to_use_agent) (int use);
 844
 845     /* Is the target able to use agent in current state?  */
 846     int (*to_can_use_agent) (void);
 847
 848     int to_magic;
 849     /* Need sub-structure for target machine related rather than comm related?
 850      */
 851   };
 852
 853 /* Magic number for checking ops size.  If a struct doesn't end with this
 854    number, somebody changed the declaration but didn't change all the
 855    places that initialize one.  */
 856
 857 #define OPS_MAGIC       3840
 858
 859 /* The ops structure for our "current" target process.  This should
 860    never be NULL.  If there is no target, it points to the dummy_target.  */
 861
 862 extern struct target_ops current_target;
 863
 864 /* Define easy words for doing these operations on our current target.  */
 865
 866 #define target_shortname        (current_target.to_shortname)
 867 #define target_longname         (current_target.to_longname)
 868
 869 /* Does whatever cleanup is required for a target that we are no
 870    longer going to be calling.  QUITTING indicates that GDB is exiting
 871    and should not get hung on an error (otherwise it is important to
 872    perform clean termination, even if it takes a while).  This routine
 873    is automatically always called after popping the target off the
 874    target stack - the target's own methods are no longer available
 875    through the target vector.  Closing file descriptors and freeing all
 876    memory allocated memory are typical things it should do.  */
 877
 878 void target_close (struct target_ops *targ, int quitting);
 879
 880 /* Attaches to a process on the target side.  Arguments are as passed
 881    to the `attach' command by the user.  This routine can be called
 882    when the target is not on the target-stack, if the target_can_run
 883    routine returns 1; in that case, it must push itself onto the stack.
 884    Upon exit, the target should be ready for normal operations, and
 885    should be ready to deliver the status of the process immediately
 886    (without waiting) to an upcoming target_wait call.  */
 887
 888 void target_attach (char *, int);
 889
 890 /* Some targets don't generate traps when attaching to the inferior,
 891    or their target_attach implementation takes care of the waiting.
 892    These targets must set to_attach_no_wait.  */
 893
 894 #define target_attach_no_wait \
 895      (current_target.to_attach_no_wait)
 896
 897 /* The target_attach operation places a process under debugger control,
 898    and stops the process.
 899
 900    This operation provides a target-specific hook that allows the
 901    necessary bookkeeping to be performed after an attach completes.  */
 902 #define target_post_attach(pid) \
 903      (*current_target.to_post_attach) (pid)
 904
 905 /* Takes a program previously attached to and detaches it.
 906    The program may resume execution (some targets do, some don't) and will
 907    no longer stop on signals, etc.  We better not have left any breakpoints
 908    in the program or it'll die when it hits one.  ARGS is arguments
 909    typed by the user (e.g. a signal to send the process).  FROM_TTY
 910    says whether to be verbose or not.  */
 911
 912 extern void target_detach (char *, int);
 913
 914 /* Disconnect from the current target without resuming it (leaving it
 915    waiting for a debugger).  */
 916
 917 extern void target_disconnect (char *, int);
 918
 919 /* Resume execution of the target process PTID.  STEP says whether to
 920    single-step or to run free; SIGGNAL is the signal to be given to
 921    the target, or TARGET_SIGNAL_0 for no signal.  The caller may not
 922    pass TARGET_SIGNAL_DEFAULT.  */
 923
 924 extern void target_resume (ptid_t ptid, int step, enum target_signal signal);
 925
 926 /* Wait for process pid to do something.  PTID = -1 to wait for any
 927    pid to do something.  Return pid of child, or -1 in case of error;
 928    store status through argument pointer STATUS.  Note that it is
 929    _NOT_ OK to throw_exception() out of target_wait() without popping
 930    the debugging target from the stack; GDB isn't prepared to get back
 931    to the prompt with a debugging target but without the frame cache,
 932    stop_pc, etc., set up.  OPTIONS is a bitwise OR of TARGET_W*
 933    options.  */
 934
 935 extern ptid_t target_wait (ptid_t ptid, struct target_waitstatus *status,
 936                            int options);
 937
 938 /* Fetch at least register REGNO, or all regs if regno == -1.  No result.  */
 939
 940 extern void target_fetch_registers (struct regcache *regcache, int regno);
 941
 942 /* Store at least register REGNO, or all regs if REGNO == -1.
 943    It can store as many registers as it wants to, so target_prepare_to_store
 944    must have been previously called.  Calls error() if there are problems.  */
 945
 946 extern void target_store_registers (struct regcache *regcache, int regs);
 947
 948 /* Get ready to modify the registers array.  On machines which store
 949    individual registers, this doesn't need to do anything.  On machines
 950    which store all the registers in one fell swoop, this makes sure
 951    that REGISTERS contains all the registers from the program being
 952    debugged.  */
 953
 954 #define target_prepare_to_store(regcache)       \
 955      (*current_target.to_prepare_to_store) (regcache)
 956
 957 /* Determine current address space of thread PTID.  */
 958
 959 struct address_space *target_thread_address_space (ptid_t);
 960
 961 /* Implement the "info proc" command.  */
 962
 963 void target_info_proc (char *, enum info_proc_what);
 964
 965 /* Returns true if this target can debug multiple processes
 966    simultaneously.  */
 967
 968 #define target_supports_multi_process() \
 969      (*current_target.to_supports_multi_process) ()
 970
 971 /* Returns true if this target can disable address space randomization.  */
 972
 973 int target_supports_disable_randomization (void);
 974
 975 /* Returns true if this target can enable and disable tracepoints
 976    while a trace experiment is running.  */
 977
 978 #define target_supports_enable_disable_tracepoint() \
 979   (*current_target.to_supports_enable_disable_tracepoint) ()
 980
 981 #define target_supports_string_tracing() \
 982   (*current_target.to_supports_string_tracing) ()
 983
 984 /* Returns true if this target can handle breakpoint conditions
 985    on its end.  */
 986
 987 #define target_supports_evaluation_of_breakpoint_conditions() \
 988   (*current_target.to_supports_evaluation_of_breakpoint_conditions) ()
 989
 990 /* Invalidate all target dcaches.  */
 991 extern void target_dcache_invalidate (void);
 992
 993 extern int target_read_string (CORE_ADDR, char **, int, int *);
 994
 995 extern int target_read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
 996
 997 extern int target_read_stack (CORE_ADDR memaddr, gdb_byte *myaddr, int len);
 998
 999 extern int target_write_memory (CORE_ADDR memaddr, const gdb_byte *myaddr,
1000                                 int len);
1001
1002 extern int target_write_raw_memory (CORE_ADDR memaddr, const gdb_byte *myaddr,
1003                                     int len);
1004
1005 /* Fetches the target's memory map.  If one is found it is sorted
1006    and returned, after some consistency checking.  Otherwise, NULL
1007    is returned.  */
1008 VEC(mem_region_s) *target_memory_map (void);
1009
1010 /* Erase the specified flash region.  */
1011 void target_flash_erase (ULONGEST address, LONGEST length);
1012
1013 /* Finish a sequence of flash operations.  */
1014 void target_flash_done (void);
1015
1016 /* Describes a request for a memory write operation.  */
1017 struct memory_write_request
1018   {
1019     /* Begining address that must be written.  */
1020     ULONGEST begin;
1021     /* Past-the-end address.  */
1022     ULONGEST end;
1023     /* The data to write.  */
1024     gdb_byte *data;
1025     /* A callback baton for progress reporting for this request.  */
1026     void *baton;
1027   };
1028 typedef struct memory_write_request memory_write_request_s;
1029 DEF_VEC_O(memory_write_request_s);
1030
1031 /* Enumeration specifying different flash preservation behaviour.  */
1032 enum flash_preserve_mode
1033   {
1034     flash_preserve,
1035     flash_discard
1036   };
1037
1038 /* Write several memory blocks at once.  This version can be more
1039    efficient than making several calls to target_write_memory, in
1040    particular because it can optimize accesses to flash memory.
1041
1042    Moreover, this is currently the only memory access function in gdb
1043    that supports writing to flash memory, and it should be used for
1044    all cases where access to flash memory is desirable.
1045
1046    REQUESTS is the vector (see vec.h) of memory_write_request.
1047    PRESERVE_FLASH_P indicates what to do with blocks which must be
1048      erased, but not completely rewritten.
1049    PROGRESS_CB is a function that will be periodically called to provide
1050      feedback to user.  It will be called with the baton corresponding
1051      to the request currently being written.  It may also be called
1052      with a NULL baton, when preserved flash sectors are being rewritten.
1053
1054    The function returns 0 on success, and error otherwise.  */
1055 int target_write_memory_blocks (VEC(memory_write_request_s) *requests,
1056                                 enum flash_preserve_mode preserve_flash_p,
1057                                 void (*progress_cb) (ULONGEST, void *));
1058
1059 /* From infrun.c.  */
1060
1061 extern int inferior_has_forked (ptid_t pid, ptid_t *child_pid);
1062
1063 extern int inferior_has_vforked (ptid_t pid, ptid_t *child_pid);
1064
1065 extern int inferior_has_execd (ptid_t pid, char **execd_pathname);
1066
1067 extern int inferior_has_called_syscall (ptid_t pid, int *syscall_number);
1068
1069 /* Print a line about the current target.  */
1070
1071 #define target_files_info()     \
1072      (*current_target.to_files_info) (&current_target)
1073
1074 /* Insert a breakpoint at address BP_TGT->placed_address in the target
1075    machine.  Result is 0 for success, or an errno value.  */
1076
1077 extern int target_insert_breakpoint (struct gdbarch *gdbarch,
1078                                      struct bp_target_info *bp_tgt);
1079
1080 /* Remove a breakpoint at address BP_TGT->placed_address in the target
1081    machine.  Result is 0 for success, or an errno value.  */
1082
1083 extern int target_remove_breakpoint (struct gdbarch *gdbarch,
1084                                      struct bp_target_info *bp_tgt);
1085
1086 /* Initialize the terminal settings we record for the inferior,
1087    before we actually run the inferior.  */
1088
1089 #define target_terminal_init() \
1090      (*current_target.to_terminal_init) ()
1091
1092 /* Put the inferior's terminal settings into effect.
1093    This is preparation for starting or resuming the inferior.  */
1094
1095 extern void target_terminal_inferior (void);
1096
1097 /* Put some of our terminal settings into effect,
1098    enough to get proper results from our output,
1099    but do not change into or out of RAW mode
1100    so that no input is discarded.
1101
1102    After doing this, either terminal_ours or terminal_inferior
1103    should be called to get back to a normal state of affairs.  */
1104
1105 #define target_terminal_ours_for_output() \
1106      (*current_target.to_terminal_ours_for_output) ()
1107
1108 /* Put our terminal settings into effect.
1109    First record the inferior's terminal settings
1110    so they can be restored properly later.  */
1111
1112 #define target_terminal_ours() \
1113      (*current_target.to_terminal_ours) ()
1114
1115 /* Save our terminal settings.
1116    This is called from TUI after entering or leaving the curses
1117    mode.  Since curses modifies our terminal this call is here
1118    to take this change into account.  */
1119
1120 #define target_terminal_save_ours() \
1121      (*current_target.to_terminal_save_ours) ()
1122
1123 /* Print useful information about our terminal status, if such a thing
1124    exists.  */
1125
1126 #define target_terminal_info(arg, from_tty) \
1127      (*current_target.to_terminal_info) (arg, from_tty)
1128
1129 /* Kill the inferior process.   Make it go away.  */
1130
1131 extern void target_kill (void);
1132
1133 /* Load an executable file into the target process.  This is expected
1134    to not only bring new code into the target process, but also to
1135    update GDB's symbol tables to match.
1136
1137    ARG contains command-line arguments, to be broken down with
1138    buildargv ().  The first non-switch argument is the filename to
1139    load, FILE; the second is a number (as parsed by strtoul (..., ...,
1140    0)), which is an offset to apply to the load addresses of FILE's
1141    sections.  The target may define switches, or other non-switch
1142    arguments, as it pleases.  */
1143
1144 extern void target_load (char *arg, int from_tty);
1145
1146 /* Start an inferior process and set inferior_ptid to its pid.
1147    EXEC_FILE is the file to run.
1148    ALLARGS is a string containing the arguments to the program.
1149    ENV is the environment vector to pass.  Errors reported with error().
1150    On VxWorks and various standalone systems, we ignore exec_file.  */
1151
1152 void target_create_inferior (char *exec_file, char *args,
1153                              char **env, int from_tty);
1154
1155 /* Some targets (such as ttrace-based HPUX) don't allow us to request
1156    notification of inferior events such as fork and vork immediately
1157    after the inferior is created.  (This because of how gdb gets an
1158    inferior created via invoking a shell to do it.  In such a scenario,
1159    if the shell init file has commands in it, the shell will fork and
1160    exec for each of those commands, and we will see each such fork
1161    event.  Very bad.)
1162
1163    Such targets will supply an appropriate definition for this function.  */
1164
1165 #define target_post_startup_inferior(ptid) \
1166      (*current_target.to_post_startup_inferior) (ptid)
1167
1168 /* On some targets, we can catch an inferior fork or vfork event when
1169    it occurs.  These functions insert/remove an already-created
1170    catchpoint for such events.  They return  0 for success, 1 if the
1171    catchpoint type is not supported and -1 for failure.  */
1172
1173 #define target_insert_fork_catchpoint(pid) \
1174      (*current_target.to_insert_fork_catchpoint) (pid)
1175
1176 #define target_remove_fork_catchpoint(pid) \
1177      (*current_target.to_remove_fork_catchpoint) (pid)
1178
1179 #define target_insert_vfork_catchpoint(pid) \
1180      (*current_target.to_insert_vfork_catchpoint) (pid)
1181
1182 #define target_remove_vfork_catchpoint(pid) \
1183      (*current_target.to_remove_vfork_catchpoint) (pid)
1184
1185 /* If the inferior forks or vforks, this function will be called at
1186    the next resume in order to perform any bookkeeping and fiddling
1187    necessary to continue debugging either the parent or child, as
1188    requested, and releasing the other.  Information about the fork
1189    or vfork event is available via get_last_target_status ().
1190    This function returns 1 if the inferior should not be resumed
1191    (i.e. there is another event pending).  */
1192
1193 int target_follow_fork (int follow_child);
1194
1195 /* On some targets, we can catch an inferior exec event when it
1196    occurs.  These functions insert/remove an already-created
1197    catchpoint for such events.  They return  0 for success, 1 if the
1198    catchpoint type is not supported and -1 for failure.  */
1199
1200 #define target_insert_exec_catchpoint(pid) \
1201      (*current_target.to_insert_exec_catchpoint) (pid)
1202
1203 #define target_remove_exec_catchpoint(pid) \
1204      (*current_target.to_remove_exec_catchpoint) (pid)
1205
1206 /* Syscall catch.
1207
1208    NEEDED is nonzero if any syscall catch (of any kind) is requested.
1209    If NEEDED is zero, it means the target can disable the mechanism to
1210    catch system calls because there are no more catchpoints of this type.
1211
1212    ANY_COUNT is nonzero if a generic (filter-less) syscall catch is
1213    being requested.  In this case, both TABLE_SIZE and TABLE should
1214    be ignored.
1215
1216    TABLE_SIZE is the number of elements in TABLE.  It only matters if
1217    ANY_COUNT is zero.
1218
1219    TABLE is an array of ints, indexed by syscall number.  An element in
1220    this array is nonzero if that syscall should be caught.  This argument
1221    only matters if ANY_COUNT is zero.
1222
1223    Return 0 for success, 1 if syscall catchpoints are not supported or -1
1224    for failure.  */
1225
1226 #define target_set_syscall_catchpoint(pid, needed, any_count, table_size, table) \
1227      (*current_target.to_set_syscall_catchpoint) (pid, needed, any_count, \
1228                                                   table_size, table)
1229
1230 /* Returns TRUE if PID has exited.  And, also sets EXIT_STATUS to the
1231    exit code of PID, if any.  */
1232
1233 #define target_has_exited(pid,wait_status,exit_status) \
1234      (*current_target.to_has_exited) (pid,wait_status,exit_status)
1235
1236 /* The debugger has completed a blocking wait() call.  There is now
1237    some process event that must be processed.  This function should
1238    be defined by those targets that require the debugger to perform
1239    cleanup or internal state changes in response to the process event.  */
1240
1241 /* The inferior process has died.  Do what is right.  */
1242
1243 void target_mourn_inferior (void);
1244
1245 /* Does target have enough data to do a run or attach command? */
1246
1247 #define target_can_run(t) \
1248      ((t)->to_can_run) ()
1249
1250 /* Set list of signals to be handled in the target.
1251
1252    PASS_SIGNALS is an array of size NSIG, indexed by target signal number
1253    (enum target_signal).  For every signal whose entry in this array is
1254    non-zero, the target is allowed -but not required- to skip reporting
1255    arrival of the signal to the GDB core by returning from target_wait,
1256    and to pass the signal directly to the inferior instead.
1257
1258    However, if the target is hardware single-stepping a thread that is
1259    about to receive a signal, it needs to be reported in any case, even
1260    if mentioned in a previous target_pass_signals call.   */
1261
1262 extern void target_pass_signals (int nsig, unsigned char *pass_signals);
1263
1264 /* Check to see if a thread is still alive.  */
1265
1266 extern int target_thread_alive (ptid_t ptid);
1267
1268 /* Query for new threads and add them to the thread list.  */
1269
1270 extern void target_find_new_threads (void);
1271
1272 /* Make target stop in a continuable fashion.  (For instance, under
1273    Unix, this should act like SIGSTOP).  This function is normally
1274    used by GUIs to implement a stop button.  */
1275
1276 extern void target_stop (ptid_t ptid);
1277
1278 /* Send the specified COMMAND to the target's monitor
1279    (shell,interpreter) for execution.  The result of the query is
1280    placed in OUTBUF.  */
1281
1282 #define target_rcmd(command, outbuf) \
1283      (*current_target.to_rcmd) (command, outbuf)
1284
1285
1286 /* Does the target include all of memory, or only part of it?  This
1287    determines whether we look up the target chain for other parts of
1288    memory if this target can't satisfy a request.  */
1289
1290 extern int target_has_all_memory_1 (void);
1291 #define target_has_all_memory target_has_all_memory_1 ()
1292
1293 /* Does the target include memory?  (Dummy targets don't.)  */
1294
1295 extern int target_has_memory_1 (void);
1296 #define target_has_memory target_has_memory_1 ()
1297
1298 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
1299    we start a process.)  */
1300
1301 extern int target_has_stack_1 (void);
1302 #define target_has_stack target_has_stack_1 ()
1303
1304 /* Does the target have registers?  (Exec files don't.)  */
1305
1306 extern int target_has_registers_1 (void);
1307 #define target_has_registers target_has_registers_1 ()
1308
1309 /* Does the target have execution?  Can we make it jump (through
1310    hoops), or pop its stack a few times?  This means that the current
1311    target is currently executing; for some targets, that's the same as
1312    whether or not the target is capable of execution, but there are
1313    also targets which can be current while not executing.  In that
1314    case this will become true after target_create_inferior or
1315    target_attach.  */
1316
1317 extern int target_has_execution_1 (ptid_t);
1318
1319 /* Like target_has_execution_1, but always passes inferior_ptid.  */
1320
1321 extern int target_has_execution_current (void);
1322
1323 #define target_has_execution target_has_execution_current ()
1324
1325 /* Default implementations for process_stratum targets.  Return true
1326    if there's a selected inferior, false otherwise.  */
1327
1328 extern int default_child_has_all_memory (struct target_ops *ops);
1329 extern int default_child_has_memory (struct target_ops *ops);
1330 extern int default_child_has_stack (struct target_ops *ops);
1331 extern int default_child_has_registers (struct target_ops *ops);
1332 extern int default_child_has_execution (struct target_ops *ops,
1333                                         ptid_t the_ptid);
1334
1335 /* Can the target support the debugger control of thread execution?
1336    Can it lock the thread scheduler?  */
1337
1338 #define target_can_lock_scheduler \
1339      (current_target.to_has_thread_control & tc_schedlock)
1340
1341 /* Should the target enable async mode if it is supported?  Temporary
1342    cludge until async mode is a strict superset of sync mode.  */
1343 extern int target_async_permitted;
1344
1345 /* Can the target support asynchronous execution?  */
1346 #define target_can_async_p() (current_target.to_can_async_p ())
1347
1348 /* Is the target in asynchronous execution mode?  */
1349 #define target_is_async_p() (current_target.to_is_async_p ())
1350
1351 int target_supports_non_stop (void);
1352
1353 /* Put the target in async mode with the specified callback function.  */
1354 #define target_async(CALLBACK,CONTEXT) \
1355      (current_target.to_async ((CALLBACK), (CONTEXT)))
1356
1357 #define target_execution_direction() \
1358   (current_target.to_execution_direction ())
1359
1360 /* Converts a process id to a string.  Usually, the string just contains
1361    `process xyz', but on some systems it may contain
1362    `process xyz thread abc'.  */
1363
1364 extern char *target_pid_to_str (ptid_t ptid);
1365
1366 extern char *normal_pid_to_str (ptid_t ptid);
1367
1368 /* Return a short string describing extra information about PID,
1369    e.g. "sleeping", "runnable", "running on LWP 3".  Null return value
1370    is okay.  */
1371
1372 #define target_extra_thread_info(TP) \
1373      (current_target.to_extra_thread_info (TP))
1374
1375 /* Return the thread's name.  A NULL result means that the target
1376    could not determine this thread's name.  */
1377
1378 extern char *target_thread_name (struct thread_info *);
1379
1380 /* Attempts to find the pathname of the executable file
1381    that was run to create a specified process.
1382
1383    The process PID must be stopped when this operation is used.
1384
1385    If the executable file cannot be determined, NULL is returned.
1386
1387    Else, a pointer to a character string containing the pathname
1388    is returned.  This string should be copied into a buffer by
1389    the client if the string will not be immediately used, or if
1390    it must persist.  */
1391
1392 #define target_pid_to_exec_file(pid) \
1393      (current_target.to_pid_to_exec_file) (pid)
1394
1395 /* See the to_thread_architecture description in struct target_ops.  */
1396
1397 #define target_thread_architecture(ptid) \
1398      (current_target.to_thread_architecture (&current_target, ptid))
1399
1400 /*
1401  * Iterator function for target memory regions.
1402  * Calls a callback function once for each memory region 'mapped'
1403  * in the child process.  Defined as a simple macro rather than
1404  * as a function macro so that it can be tested for nullity.
1405  */
1406
1407 #define target_find_memory_regions(FUNC, DATA) \
1408      (current_target.to_find_memory_regions) (FUNC, DATA)
1409
1410 /*
1411  * Compose corefile .note section.
1412  */
1413
1414 #define target_make_corefile_notes(BFD, SIZE_P) \
1415      (current_target.to_make_corefile_notes) (BFD, SIZE_P)
1416
1417 /* Bookmark interfaces.  */
1418 #define target_get_bookmark(ARGS, FROM_TTY) \
1419      (current_target.to_get_bookmark) (ARGS, FROM_TTY)
1420
1421 #define target_goto_bookmark(ARG, FROM_TTY) \
1422      (current_target.to_goto_bookmark) (ARG, FROM_TTY)
1423
1424 /* Hardware watchpoint interfaces.  */
1425
1426 /* Returns non-zero if we were stopped by a hardware watchpoint (memory read or
1427    write).  Only the INFERIOR_PTID task is being queried.  */
1428
1429 #define target_stopped_by_watchpoint \
1430    (*current_target.to_stopped_by_watchpoint)
1431
1432 /* Non-zero if we have steppable watchpoints  */
1433
1434 #define target_have_steppable_watchpoint \
1435    (current_target.to_have_steppable_watchpoint)
1436
1437 /* Non-zero if we have continuable watchpoints  */
1438
1439 #define target_have_continuable_watchpoint \
1440    (current_target.to_have_continuable_watchpoint)
1441
1442 /* Provide defaults for hardware watchpoint functions.  */
1443
1444 /* If the *_hw_beakpoint functions have not been defined
1445    elsewhere use the definitions in the target vector.  */
1446
1447 /* Returns non-zero if we can set a hardware watchpoint of type TYPE.  TYPE is
1448    one of bp_hardware_watchpoint, bp_read_watchpoint, bp_write_watchpoint, or
1449    bp_hardware_breakpoint.  CNT is the number of such watchpoints used so far
1450    (including this one?).  OTHERTYPE is who knows what...  */
1451
1452 #define target_can_use_hardware_watchpoint(TYPE,CNT,OTHERTYPE) \
1453  (*current_target.to_can_use_hw_breakpoint) (TYPE, CNT, OTHERTYPE);
1454
1455 /* Returns the number of debug registers needed to watch the given
1456    memory region, or zero if not supported.  */
1457
1458 #define target_region_ok_for_hw_watchpoint(addr, len) \
1459     (*current_target.to_region_ok_for_hw_watchpoint) (addr, len)
1460
1461
1462 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.
1463    TYPE is 0 for write, 1 for read, and 2 for read/write accesses.
1464    COND is the expression for its condition, or NULL if there's none.
1465    Returns 0 for success, 1 if the watchpoint type is not supported,
1466    -1 for failure.  */
1467
1468 #define target_insert_watchpoint(addr, len, type, cond) \
1469      (*current_target.to_insert_watchpoint) (addr, len, type, cond)
1470
1471 #define target_remove_watchpoint(addr, len, type, cond) \
1472      (*current_target.to_remove_watchpoint) (addr, len, type, cond)
1473
1474 /* Insert a new masked watchpoint at ADDR using the mask MASK.
1475    RW may be hw_read for a read watchpoint, hw_write for a write watchpoint
1476    or hw_access for an access watchpoint.  Returns 0 for success, 1 if
1477    masked watchpoints are not supported, -1 for failure.  */
1478
1479 extern int target_insert_mask_watchpoint (CORE_ADDR, CORE_ADDR, int);
1480
1481 /* Remove a masked watchpoint at ADDR with the mask MASK.
1482    RW may be hw_read for a read watchpoint, hw_write for a write watchpoint
1483    or hw_access for an access watchpoint.  Returns 0 for success, non-zero
1484    for failure.  */
1485
1486 extern int target_remove_mask_watchpoint (CORE_ADDR, CORE_ADDR, int);
1487
1488 #define target_insert_hw_breakpoint(gdbarch, bp_tgt) \
1489      (*current_target.to_insert_hw_breakpoint) (gdbarch, bp_tgt)
1490
1491 #define target_remove_hw_breakpoint(gdbarch, bp_tgt) \
1492      (*current_target.to_remove_hw_breakpoint) (gdbarch, bp_tgt)
1493
1494 /* Return number of debug registers needed for a ranged breakpoint,
1495    or -1 if ranged breakpoints are not supported.  */
1496
1497 extern int target_ranged_break_num_registers (void);
1498
1499 /* Return non-zero if target knows the data address which triggered this
1500    target_stopped_by_watchpoint, in such case place it to *ADDR_P.  Only the
1501    INFERIOR_PTID task is being queried.  */
1502 #define target_stopped_data_address(target, addr_p) \
1503     (*target.to_stopped_data_address) (target, addr_p)
1504
1505 /* Return non-zero if ADDR is within the range of a watchpoint spanning
1506    LENGTH bytes beginning at START.  */
1507 #define target_watchpoint_addr_within_range(target, addr, start, length) \
1508   (*target.to_watchpoint_addr_within_range) (target, addr, start, length)
1509
1510 /* Return non-zero if the target is capable of using hardware to evaluate
1511    the condition expression.  In this case, if the condition is false when
1512    the watched memory location changes, execution may continue without the
1513    debugger being notified.
1514
1515    Due to limitations in the hardware implementation, it may be capable of
1516    avoiding triggering the watchpoint in some cases where the condition
1517    expression is false, but may report some false positives as well.
1518    For this reason, GDB will still evaluate the condition expression when
1519    the watchpoint triggers.  */
1520 #define target_can_accel_watchpoint_condition(addr, len, type, cond) \
1521   (*current_target.to_can_accel_watchpoint_condition) (addr, len, type, cond)
1522
1523 /* Return number of debug registers needed for a masked watchpoint,
1524    -1 if masked watchpoints are not supported or -2 if the given address
1525    and mask combination cannot be used.  */
1526
1527 extern int target_masked_watch_num_registers (CORE_ADDR addr, CORE_ADDR mask);
1528
1529 /* Target can execute in reverse?  */
1530 #define target_can_execute_reverse \
1531      (current_target.to_can_execute_reverse ? \
1532       current_target.to_can_execute_reverse () : 0)
1533
1534 extern const struct target_desc *target_read_description (struct target_ops *);
1535
1536 #define target_get_ada_task_ptid(lwp, tid) \
1537      (*current_target.to_get_ada_task_ptid) (lwp,tid)
1538
1539 /* Utility implementation of searching memory.  */
1540 extern int simple_search_memory (struct target_ops* ops,
1541                                  CORE_ADDR start_addr,
1542                                  ULONGEST search_space_len,
1543                                  const gdb_byte *pattern,
1544                                  ULONGEST pattern_len,
1545                                  CORE_ADDR *found_addrp);
1546
1547 /* Main entry point for searching memory.  */
1548 extern int target_search_memory (CORE_ADDR start_addr,
1549                                  ULONGEST search_space_len,
1550                                  const gdb_byte *pattern,
1551                                  ULONGEST pattern_len,
1552                                  CORE_ADDR *found_addrp);
1553
1554 /* Target file operations.  */
1555
1556 /* Open FILENAME on the target, using FLAGS and MODE.  Return a
1557    target file descriptor, or -1 if an error occurs (and set
1558    *TARGET_ERRNO).  */
1559 extern int target_fileio_open (const char *filename, int flags, int mode,
1560                                int *target_errno);
1561
1562 /* Write up to LEN bytes from WRITE_BUF to FD on the target.
1563    Return the number of bytes written, or -1 if an error occurs
1564    (and set *TARGET_ERRNO).  */
1565 extern int target_fileio_pwrite (int fd, const gdb_byte *write_buf, int len,
1566                                  ULONGEST offset, int *target_errno);
1567
1568 /* Read up to LEN bytes FD on the target into READ_BUF.
1569    Return the number of bytes read, or -1 if an error occurs
1570    (and set *TARGET_ERRNO).  */
1571 extern int target_fileio_pread (int fd, gdb_byte *read_buf, int len,
1572                                 ULONGEST offset, int *target_errno);
1573
1574 /* Close FD on the target.  Return 0, or -1 if an error occurs
1575    (and set *TARGET_ERRNO).  */
1576 extern int target_fileio_close (int fd, int *target_errno);
1577
1578 /* Unlink FILENAME on the target.  Return 0, or -1 if an error
1579    occurs (and set *TARGET_ERRNO).  */
1580 extern int target_fileio_unlink (const char *filename, int *target_errno);
1581
1582 /* Read value of symbolic link FILENAME on the target.  Return a
1583    null-terminated string allocated via xmalloc, or NULL if an error
1584    occurs (and set *TARGET_ERRNO).  */
1585 extern char *target_fileio_readlink (const char *filename, int *target_errno);
1586
1587 /* Read target file FILENAME.  The return value will be -1 if the transfer
1588    fails or is not supported; 0 if the object is empty; or the length
1589    of the object otherwise.  If a positive value is returned, a
1590    sufficiently large buffer will be allocated using xmalloc and
1591    returned in *BUF_P containing the contents of the object.
1592
1593    This method should be used for objects sufficiently small to store
1594    in a single xmalloc'd buffer, when no fixed bound on the object's
1595    size is known in advance.  */
1596 extern LONGEST target_fileio_read_alloc (const char *filename,
1597                                          gdb_byte **buf_p);
1598
1599 /* Read target file FILENAME.  The result is NUL-terminated and
1600    returned as a string, allocated using xmalloc.  If an error occurs
1601    or the transfer is unsupported, NULL is returned.  Empty objects
1602    are returned as allocated but empty strings.  A warning is issued
1603    if the result contains any embedded NUL bytes.  */
1604 extern char *target_fileio_read_stralloc (const char *filename);
1605
1606
1607 /* Tracepoint-related operations.  */
1608
1609 #define target_trace_init() \
1610   (*current_target.to_trace_init) ()
1611
1612 #define target_download_tracepoint(t) \
1613   (*current_target.to_download_tracepoint) (t)
1614
1615 #define target_can_download_tracepoint() \
1616   (*current_target.to_can_download_tracepoint) ()
1617
1618 #define target_download_trace_state_variable(tsv) \
1619   (*current_target.to_download_trace_state_variable) (tsv)
1620
1621 #define target_enable_tracepoint(loc) \
1622   (*current_target.to_enable_tracepoint) (loc)
1623
1624 #define target_disable_tracepoint(loc) \
1625   (*current_target.to_disable_tracepoint) (loc)
1626
1627 #define target_trace_start() \
1628   (*current_target.to_trace_start) ()
1629
1630 #define target_trace_set_readonly_regions() \
1631   (*current_target.to_trace_set_readonly_regions) ()
1632
1633 #define target_get_trace_status(ts) \
1634   (*current_target.to_get_trace_status) (ts)
1635
1636 #define target_get_tracepoint_status(tp,utp)            \
1637   (*current_target.to_get_tracepoint_status) (tp, utp)
1638
1639 #define target_trace_stop() \
1640   (*current_target.to_trace_stop) ()
1641
1642 #define target_trace_find(type,num,addr1,addr2,tpp) \
1643   (*current_target.to_trace_find) ((type), (num), (addr1), (addr2), (tpp))
1644
1645 #define target_get_trace_state_variable_value(tsv,val) \
1646   (*current_target.to_get_trace_state_variable_value) ((tsv), (val))
1647
1648 #define target_save_trace_data(filename) \
1649   (*current_target.to_save_trace_data) (filename)
1650
1651 #define target_upload_tracepoints(utpp) \
1652   (*current_target.to_upload_tracepoints) (utpp)
1653
1654 #define target_upload_trace_state_variables(utsvp) \
1655   (*current_target.to_upload_trace_state_variables) (utsvp)
1656
1657 #define target_get_raw_trace_data(buf,offset,len) \
1658   (*current_target.to_get_raw_trace_data) ((buf), (offset), (len))
1659
1660 #define target_get_min_fast_tracepoint_insn_len() \
1661   (*current_target.to_get_min_fast_tracepoint_insn_len) ()
1662
1663 #define target_set_disconnected_tracing(val) \
1664   (*current_target.to_set_disconnected_tracing) (val)
1665
1666 #define target_set_circular_trace_buffer(val)   \
1667   (*current_target.to_set_circular_trace_buffer) (val)
1668
1669 #define target_set_trace_notes(user,notes,stopnotes)            \
1670   (*current_target.to_set_trace_notes) ((user), (notes), (stopnotes))
1671
1672 #define target_get_tib_address(ptid, addr) \
1673   (*current_target.to_get_tib_address) ((ptid), (addr))
1674
1675 #define target_set_permissions() \
1676   (*current_target.to_set_permissions) ()
1677
1678 #define target_static_tracepoint_marker_at(addr, marker) \
1679   (*current_target.to_static_tracepoint_marker_at) (addr, marker)
1680
1681 #define target_static_tracepoint_markers_by_strid(marker_id) \
1682   (*current_target.to_static_tracepoint_markers_by_strid) (marker_id)
1683
1684 #define target_traceframe_info() \
1685   (*current_target.to_traceframe_info) ()
1686
1687 #define target_use_agent(use) \
1688   (*current_target.to_use_agent) (use)
1689
1690 #define target_can_use_agent() \
1691   (*current_target.to_can_use_agent) ()
1692
1693 /* Command logging facility.  */
1694
1695 #define target_log_command(p)                                           \
1696   do                                                                    \
1697     if (current_target.to_log_command)                                  \
1698       (*current_target.to_log_command) (p);                             \
1699   while (0)
1700
1701
1702 extern int target_core_of_thread (ptid_t ptid);
1703
1704 /* Verify that the memory in the [MEMADDR, MEMADDR+SIZE) range matches
1705    the contents of [DATA,DATA+SIZE).  Returns 1 if there's a match, 0
1706    if there's a mismatch, and -1 if an error is encountered while
1707    reading memory.  Throws an error if the functionality is found not
1708    to be supported by the current target.  */
1709 int target_verify_memory (const gdb_byte *data,
1710                           CORE_ADDR memaddr, ULONGEST size);
1711
1712 /* Routines for maintenance of the target structures...
1713
1714    add_target:   Add a target to the list of all possible targets.
1715
1716    push_target:  Make this target the top of the stack of currently used
1717    targets, within its particular stratum of the stack.  Result
1718    is 0 if now atop the stack, nonzero if not on top (maybe
1719    should warn user).
1720
1721    unpush_target: Remove this from the stack of currently used targets,
1722    no matter where it is on the list.  Returns 0 if no
1723    change, 1 if removed from stack.
1724
1725    pop_target:   Remove the top thing on the stack of current targets.  */
1726
1727 extern void add_target (struct target_ops *);
1728
1729 extern void push_target (struct target_ops *);
1730
1731 extern int unpush_target (struct target_ops *);
1732
1733 extern void target_pre_inferior (int);
1734
1735 extern void target_preopen (int);
1736
1737 extern void pop_target (void);
1738
1739 /* Does whatever cleanup is required to get rid of all pushed targets.
1740    QUITTING is propagated to target_close; it indicates that GDB is
1741    exiting and should not get hung on an error (otherwise it is
1742    important to perform clean termination, even if it takes a
1743    while).  */
1744 extern void pop_all_targets (int quitting);
1745
1746 /* Like pop_all_targets, but pops only targets whose stratum is
1747    strictly above ABOVE_STRATUM.  */
1748 extern void pop_all_targets_above (enum strata above_stratum, int quitting);
1749
1750 extern int target_is_pushed (struct target_ops *t);
1751
1752 extern CORE_ADDR target_translate_tls_address (struct objfile *objfile,
1753                                                CORE_ADDR offset);
1754
1755 /* Struct target_section maps address ranges to file sections.  It is
1756    mostly used with BFD files, but can be used without (e.g. for handling
1757    raw disks, or files not in formats handled by BFD).  */
1758
1759 struct target_section
1760   {
1761     CORE_ADDR addr;             /* Lowest address in section */
1762     CORE_ADDR endaddr;          /* 1+highest address in section */
1763
1764     struct bfd_section *the_bfd_section;
1765
1766     bfd *bfd;                   /* BFD file pointer */
1767   };
1768
1769 /* Holds an array of target sections.  Defined by [SECTIONS..SECTIONS_END[.  */
1770
1771 struct target_section_table
1772 {
1773   struct target_section *sections;
1774   struct target_section *sections_end;
1775 };
1776
1777 /* Return the "section" containing the specified address.  */
1778 struct target_section *target_section_by_addr (struct target_ops *target,
1779                                                CORE_ADDR addr);
1780
1781 /* Return the target section table this target (or the targets
1782    beneath) currently manipulate.  */
1783
1784 extern struct target_section_table *target_get_section_table
1785   (struct target_ops *target);
1786
1787 /* From mem-break.c */
1788
1789 extern int memory_remove_breakpoint (struct gdbarch *,
1790                                      struct bp_target_info *);
1791
1792 extern int memory_insert_breakpoint (struct gdbarch *,
1793                                      struct bp_target_info *);
1794
1795 extern int default_memory_remove_breakpoint (struct gdbarch *,
1796                                              struct bp_target_info *);
1797
1798 extern int default_memory_insert_breakpoint (struct gdbarch *,
1799                                              struct bp_target_info *);
1800
1801
1802 /* From target.c */
1803
1804 extern void initialize_targets (void);
1805
1806 extern void noprocess (void) ATTRIBUTE_NORETURN;
1807
1808 extern void target_require_runnable (void);
1809
1810 extern void find_default_attach (struct target_ops *, char *, int);
1811
1812 extern void find_default_create_inferior (struct target_ops *,
1813                                           char *, char *, char **, int);
1814
1815 extern struct target_ops *find_run_target (void);
1816
1817 extern struct target_ops *find_target_beneath (struct target_ops *);
1818
1819 /* Read OS data object of type TYPE from the target, and return it in
1820    XML format.  The result is NUL-terminated and returned as a string,
1821    allocated using xmalloc.  If an error occurs or the transfer is
1822    unsupported, NULL is returned.  Empty objects are returned as
1823    allocated but empty strings.  */
1824
1825 extern char *target_get_osdata (const char *type);
1826
1827 \f
1828 /* Stuff that should be shared among the various remote targets.  */
1829
1830 /* Debugging level.  0 is off, and non-zero values mean to print some debug
1831    information (higher values, more information).  */
1832 extern int remote_debug;
1833
1834 /* Speed in bits per second, or -1 which means don't mess with the speed.  */
1835 extern int baud_rate;
1836 /* Timeout limit for response from target.  */
1837 extern int remote_timeout;
1838
1839 \f
1840 /* Functions for helping to write a native target.  */
1841
1842 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
1843 extern void store_waitstatus (struct target_waitstatus *, int);
1844
1845 /* Set the show memory breakpoints mode to show, and installs a cleanup
1846    to restore it back to the current value.  */
1847 extern struct cleanup *make_show_memory_breakpoints_cleanup (int show);
1848
1849 extern int may_write_registers;
1850 extern int may_write_memory;
1851 extern int may_insert_breakpoints;
1852 extern int may_insert_tracepoints;
1853 extern int may_insert_fast_tracepoints;
1854 extern int may_stop;
1855
1856 extern void update_target_permissions (void);
1857
1858 \f
1859 /* Imported from machine dependent code.  */
1860
1861 /* Blank target vector entries are initialized to target_ignore.  */
1862 void target_ignore (void);
1863
1864 #endif /* !defined (TARGET_H) */