gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   3    2000, 2001, 2002 Free Software Foundation, Inc.
   4    Contributed by Cygnus Support.  Written by John Gilmore.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #if !defined (TARGET_H)
  24 #define TARGET_H
  25
  26 struct objfile;
  27 struct ui_file;
  28 struct mem_attrib;
  29
  30 /* This include file defines the interface between the main part
  31    of the debugger, and the part which is target-specific, or
  32    specific to the communications interface between us and the
  33    target.
  34
  35    A TARGET is an interface between the debugger and a particular
  36    kind of file or process.  Targets can be STACKED in STRATA,
  37    so that more than one target can potentially respond to a request.
  38    In particular, memory accesses will walk down the stack of targets
  39    until they find a target that is interested in handling that particular
  40    address.  STRATA are artificial boundaries on the stack, within
  41    which particular kinds of targets live.  Strata exist so that
  42    people don't get confused by pushing e.g. a process target and then
  43    a file target, and wondering why they can't see the current values
  44    of variables any more (the file target is handling them and they
  45    never get to the process target).  So when you push a file target,
  46    it goes into the file stratum, which is always below the process
  47    stratum.  */
  48
  49 #include "bfd.h"
  50 #include "symtab.h"
  51 #include "dcache.h"
  52 #include "memattr.h"
  53
  54 enum strata
  55   {
  56     dummy_stratum,              /* The lowest of the low */
  57     file_stratum,               /* Executable files, etc */
  58     core_stratum,               /* Core dump files */
  59     download_stratum,           /* Downloading of remote targets */
  60     process_stratum,            /* Executing processes */
  61     thread_stratum              /* Executing threads */
  62   };
  63
  64 enum thread_control_capabilities
  65   {
  66     tc_none = 0,                /* Default: can't control thread execution.  */
  67     tc_schedlock = 1,           /* Can lock the thread scheduler.  */
  68     tc_switch = 2               /* Can switch the running thread on demand.  */
  69   };
  70
  71 /* Stuff for target_wait.  */
  72
  73 /* Generally, what has the program done?  */
  74 enum target_waitkind
  75   {
  76     /* The program has exited.  The exit status is in value.integer.  */
  77     TARGET_WAITKIND_EXITED,
  78
  79     /* The program has stopped with a signal.  Which signal is in
  80        value.sig.  */
  81     TARGET_WAITKIND_STOPPED,
  82
  83     /* The program has terminated with a signal.  Which signal is in
  84        value.sig.  */
  85     TARGET_WAITKIND_SIGNALLED,
  86
  87     /* The program is letting us know that it dynamically loaded something
  88        (e.g. it called load(2) on AIX).  */
  89     TARGET_WAITKIND_LOADED,
  90
  91     /* The program has forked.  A "related" process' ID is in
  92        value.related_pid.  I.e., if the child forks, value.related_pid
  93        is the parent's ID.  */
  94
  95     TARGET_WAITKIND_FORKED,
  96
  97     /* The program has vforked.  A "related" process's ID is in
  98        value.related_pid.  */
  99
 100     TARGET_WAITKIND_VFORKED,
 101
 102     /* The program has exec'ed a new executable file.  The new file's
 103        pathname is pointed to by value.execd_pathname.  */
 104
 105     TARGET_WAITKIND_EXECD,
 106
 107     /* The program has entered or returned from a system call.  On
 108        HP-UX, this is used in the hardware watchpoint implementation.
 109        The syscall's unique integer ID number is in value.syscall_id */
 110
 111     TARGET_WAITKIND_SYSCALL_ENTRY,
 112     TARGET_WAITKIND_SYSCALL_RETURN,
 113
 114     /* Nothing happened, but we stopped anyway.  This perhaps should be handled
 115        within target_wait, but I'm not sure target_wait should be resuming the
 116        inferior.  */
 117     TARGET_WAITKIND_SPURIOUS,
 118
 119     /* An event has occured, but we should wait again.
 120        Remote_async_wait() returns this when there is an event
 121        on the inferior, but the rest of the world is not interested in
 122        it. The inferior has not stopped, but has just sent some output
 123        to the console, for instance. In this case, we want to go back
 124        to the event loop and wait there for another event from the
 125        inferior, rather than being stuck in the remote_async_wait()
 126        function. This way the event loop is responsive to other events,
 127        like for instance the user typing.  */
 128     TARGET_WAITKIND_IGNORE
 129   };
 130
 131 struct target_waitstatus
 132   {
 133     enum target_waitkind kind;
 134
 135     /* Forked child pid, execd pathname, exit status or signal number.  */
 136     union
 137       {
 138         int integer;
 139         enum target_signal sig;
 140         int related_pid;
 141         char *execd_pathname;
 142         int syscall_id;
 143       }
 144     value;
 145   };
 146
 147 /* Possible types of events that the inferior handler will have to
 148    deal with.  */
 149 enum inferior_event_type
 150   {
 151     /* There is a request to quit the inferior, abandon it.  */
 152     INF_QUIT_REQ,
 153     /* Process a normal inferior event which will result in target_wait
 154        being called.  */
 155     INF_REG_EVENT,
 156     /* Deal with an error on the inferior.  */
 157     INF_ERROR,
 158     /* We are called because a timer went off.  */
 159     INF_TIMER,
 160     /* We are called to do stuff after the inferior stops.  */
 161     INF_EXEC_COMPLETE,
 162     /* We are called to do some stuff after the inferior stops, but we
 163        are expected to reenter the proceed() and
 164        handle_inferior_event() functions. This is used only in case of
 165        'step n' like commands.  */
 166     INF_EXEC_CONTINUE
 167   };
 168
 169 /* Return the string for a signal.  */
 170 extern char *target_signal_to_string (enum target_signal);
 171
 172 /* Return the name (SIGHUP, etc.) for a signal.  */
 173 extern char *target_signal_to_name (enum target_signal);
 174
 175 /* Given a name (SIGHUP, etc.), return its signal.  */
 176 enum target_signal target_signal_from_name (char *);
 177 \f
 178
 179 /* If certain kinds of activity happen, target_wait should perform
 180    callbacks.  */
 181 /* Right now we just call (*TARGET_ACTIVITY_FUNCTION) if I/O is possible
 182    on TARGET_ACTIVITY_FD.  */
 183 extern int target_activity_fd;
 184 /* Returns zero to leave the inferior alone, one to interrupt it.  */
 185 extern int (*target_activity_function) (void);
 186 \f
 187 struct thread_info;             /* fwd decl for parameter list below: */
 188
 189 struct target_ops
 190   {
 191     char *to_shortname;         /* Name this target type */
 192     char *to_longname;          /* Name for printing */
 193     char *to_doc;               /* Documentation.  Does not include trailing
 194                                    newline, and starts with a one-line descrip-
 195                                    tion (probably similar to to_longname).  */
 196     void (*to_open) (char *, int);
 197     void (*to_close) (int);
 198     void (*to_attach) (char *, int);
 199     void (*to_post_attach) (int);
 200     void (*to_detach) (char *, int);
 201     void (*to_disconnect) (char *, int);
 202     void (*to_resume) (ptid_t, int, enum target_signal);
 203     ptid_t (*to_wait) (ptid_t, struct target_waitstatus *);
 204     void (*to_post_wait) (ptid_t, int);
 205     void (*to_fetch_registers) (int);
 206     void (*to_store_registers) (int);
 207     void (*to_prepare_to_store) (void);
 208
 209     /* Transfer LEN bytes of memory between GDB address MYADDR and
 210        target address MEMADDR.  If WRITE, transfer them to the target, else
 211        transfer them from the target.  TARGET is the target from which we
 212        get this function.
 213
 214        Return value, N, is one of the following:
 215
 216        0 means that we can't handle this.  If errno has been set, it is the
 217        error which prevented us from doing it (FIXME: What about bfd_error?).
 218
 219        positive (call it N) means that we have transferred N bytes
 220        starting at MEMADDR.  We might be able to handle more bytes
 221        beyond this length, but no promises.
 222
 223        negative (call its absolute value N) means that we cannot
 224        transfer right at MEMADDR, but we could transfer at least
 225        something at MEMADDR + N.  */
 226
 227     int (*to_xfer_memory) (CORE_ADDR memaddr, char *myaddr,
 228                            int len, int write,
 229                            struct mem_attrib *attrib,
 230                            struct target_ops *target);
 231
 232     void (*to_files_info) (struct target_ops *);
 233     int (*to_insert_breakpoint) (CORE_ADDR, char *);
 234     int (*to_remove_breakpoint) (CORE_ADDR, char *);
 235     int (*to_can_use_hw_breakpoint) (int, int, int);
 236     int (*to_insert_hw_breakpoint) (CORE_ADDR, char *);
 237     int (*to_remove_hw_breakpoint) (CORE_ADDR, char *);
 238     int (*to_remove_watchpoint) (CORE_ADDR, int, int);
 239     int (*to_insert_watchpoint) (CORE_ADDR, int, int);
 240     int (*to_stopped_by_watchpoint) (void);
 241     int to_have_continuable_watchpoint;
 242     CORE_ADDR (*to_stopped_data_address) (void);
 243     int (*to_region_size_ok_for_hw_watchpoint) (int);
 244     void (*to_terminal_init) (void);
 245     void (*to_terminal_inferior) (void);
 246     void (*to_terminal_ours_for_output) (void);
 247     void (*to_terminal_ours) (void);
 248     void (*to_terminal_save_ours) (void);
 249     void (*to_terminal_info) (char *, int);
 250     void (*to_kill) (void);
 251     void (*to_load) (char *, int);
 252     int (*to_lookup_symbol) (char *, CORE_ADDR *);
 253     void (*to_create_inferior) (char *, char *, char **);
 254     void (*to_post_startup_inferior) (ptid_t);
 255     void (*to_acknowledge_created_inferior) (int);
 256     int (*to_insert_fork_catchpoint) (int);
 257     int (*to_remove_fork_catchpoint) (int);
 258     int (*to_insert_vfork_catchpoint) (int);
 259     int (*to_remove_vfork_catchpoint) (int);
 260     int (*to_follow_fork) (int);
 261     int (*to_insert_exec_catchpoint) (int);
 262     int (*to_remove_exec_catchpoint) (int);
 263     int (*to_reported_exec_events_per_exec_call) (void);
 264     int (*to_has_exited) (int, int, int *);
 265     void (*to_mourn_inferior) (void);
 266     int (*to_can_run) (void);
 267     void (*to_notice_signals) (ptid_t ptid);
 268     int (*to_thread_alive) (ptid_t ptid);
 269     void (*to_find_new_threads) (void);
 270     char *(*to_pid_to_str) (ptid_t);
 271     char *(*to_extra_thread_info) (struct thread_info *);
 272     void (*to_stop) (void);
 273     int (*to_query) (int /*char */ , char *, char *, int *);
 274     void (*to_rcmd) (char *command, struct ui_file *output);
 275     struct symtab_and_line *(*to_enable_exception_callback) (enum
 276                                                              exception_event_kind,
 277                                                              int);
 278     struct exception_event_record *(*to_get_current_exception_event) (void);
 279     char *(*to_pid_to_exec_file) (int pid);
 280     enum strata to_stratum;
 281     int to_has_all_memory;
 282     int to_has_memory;
 283     int to_has_stack;
 284     int to_has_registers;
 285     int to_has_execution;
 286     int to_has_thread_control;  /* control thread execution */
 287     struct section_table
 288      *to_sections;
 289     struct section_table
 290      *to_sections_end;
 291     /* ASYNC target controls */
 292     int (*to_can_async_p) (void);
 293     int (*to_is_async_p) (void);
 294     void (*to_async) (void (*cb) (enum inferior_event_type, void *context),
 295                       void *context);
 296     int to_async_mask_value;
 297     int (*to_find_memory_regions) (int (*) (CORE_ADDR,
 298                                             unsigned long,
 299                                             int, int, int,
 300                                             void *),
 301                                    void *);
 302     char * (*to_make_corefile_notes) (bfd *, int *);
 303
 304     /* Return the thread-local address at OFFSET in the
 305        thread-local storage for the thread PTID and the shared library
 306        or executable file given by OBJFILE.  If that block of
 307        thread-local storage hasn't been allocated yet, this function
 308        may return an error.  */
 309     CORE_ADDR (*to_get_thread_local_address) (ptid_t ptid,
 310                                               struct objfile *objfile,
 311                                               CORE_ADDR offset);
 312
 313     int to_magic;
 314     /* Need sub-structure for target machine related rather than comm related?
 315      */
 316   };
 317
 318 /* Magic number for checking ops size.  If a struct doesn't end with this
 319    number, somebody changed the declaration but didn't change all the
 320    places that initialize one.  */
 321
 322 #define OPS_MAGIC       3840
 323
 324 /* The ops structure for our "current" target process.  This should
 325    never be NULL.  If there is no target, it points to the dummy_target.  */
 326
 327 extern struct target_ops current_target;
 328
 329 /* An item on the target stack.  */
 330
 331 struct target_stack_item
 332   {
 333     struct target_stack_item *next;
 334     struct target_ops *target_ops;
 335   };
 336
 337 /* The target stack.  */
 338
 339 extern struct target_stack_item *target_stack;
 340
 341 /* Define easy words for doing these operations on our current target.  */
 342
 343 #define target_shortname        (current_target.to_shortname)
 344 #define target_longname         (current_target.to_longname)
 345
 346 /* The open routine takes the rest of the parameters from the command,
 347    and (if successful) pushes a new target onto the stack.
 348    Targets should supply this routine, if only to provide an error message.  */
 349
 350 #define target_open(name, from_tty)                                     \
 351   do {                                                                  \
 352     dcache_invalidate (target_dcache);                                  \
 353     (*current_target.to_open) (name, from_tty);                         \
 354   } while (0)
 355
 356 /* Does whatever cleanup is required for a target that we are no longer
 357    going to be calling.  Argument says whether we are quitting gdb and
 358    should not get hung in case of errors, or whether we want a clean
 359    termination even if it takes a while.  This routine is automatically
 360    always called just before a routine is popped off the target stack.
 361    Closing file descriptors and freeing memory are typical things it should
 362    do.  */
 363
 364 #define target_close(quitting)  \
 365      (*current_target.to_close) (quitting)
 366
 367 /* Attaches to a process on the target side.  Arguments are as passed
 368    to the `attach' command by the user.  This routine can be called
 369    when the target is not on the target-stack, if the target_can_run
 370    routine returns 1; in that case, it must push itself onto the stack.
 371    Upon exit, the target should be ready for normal operations, and
 372    should be ready to deliver the status of the process immediately
 373    (without waiting) to an upcoming target_wait call.  */
 374
 375 #define target_attach(args, from_tty)   \
 376      (*current_target.to_attach) (args, from_tty)
 377
 378 /* The target_attach operation places a process under debugger control,
 379    and stops the process.
 380
 381    This operation provides a target-specific hook that allows the
 382    necessary bookkeeping to be performed after an attach completes.  */
 383 #define target_post_attach(pid) \
 384      (*current_target.to_post_attach) (pid)
 385
 386 /* Takes a program previously attached to and detaches it.
 387    The program may resume execution (some targets do, some don't) and will
 388    no longer stop on signals, etc.  We better not have left any breakpoints
 389    in the program or it'll die when it hits one.  ARGS is arguments
 390    typed by the user (e.g. a signal to send the process).  FROM_TTY
 391    says whether to be verbose or not.  */
 392
 393 extern void target_detach (char *, int);
 394
 395 /* Disconnect from the current target without resuming it (leaving it
 396    waiting for a debugger).  */
 397
 398 extern void target_disconnect (char *, int);
 399
 400 /* Resume execution of the target process PTID.  STEP says whether to
 401    single-step or to run free; SIGGNAL is the signal to be given to
 402    the target, or TARGET_SIGNAL_0 for no signal.  The caller may not
 403    pass TARGET_SIGNAL_DEFAULT.  */
 404
 405 #define target_resume(ptid, step, siggnal)                              \
 406   do {                                                                  \
 407     dcache_invalidate(target_dcache);                                   \
 408     (*current_target.to_resume) (ptid, step, siggnal);                  \
 409   } while (0)
 410
 411 /* Wait for process pid to do something.  PTID = -1 to wait for any
 412    pid to do something.  Return pid of child, or -1 in case of error;
 413    store status through argument pointer STATUS.  Note that it is
 414    _NOT_ OK to throw_exception() out of target_wait() without popping
 415    the debugging target from the stack; GDB isn't prepared to get back
 416    to the prompt with a debugging target but without the frame cache,
 417    stop_pc, etc., set up.  */
 418
 419 #define target_wait(ptid, status)               \
 420      (*current_target.to_wait) (ptid, status)
 421
 422 /* The target_wait operation waits for a process event to occur, and
 423    thereby stop the process.
 424
 425    On some targets, certain events may happen in sequences.  gdb's
 426    correct response to any single event of such a sequence may require
 427    knowledge of what earlier events in the sequence have been seen.
 428
 429    This operation provides a target-specific hook that allows the
 430    necessary bookkeeping to be performed to track such sequences.  */
 431
 432 #define target_post_wait(ptid, status) \
 433      (*current_target.to_post_wait) (ptid, status)
 434
 435 /* Fetch at least register REGNO, or all regs if regno == -1.  No result.  */
 436
 437 #define target_fetch_registers(regno)   \
 438      (*current_target.to_fetch_registers) (regno)
 439
 440 /* Store at least register REGNO, or all regs if REGNO == -1.
 441    It can store as many registers as it wants to, so target_prepare_to_store
 442    must have been previously called.  Calls error() if there are problems.  */
 443
 444 #define target_store_registers(regs)    \
 445      (*current_target.to_store_registers) (regs)
 446
 447 /* Get ready to modify the registers array.  On machines which store
 448    individual registers, this doesn't need to do anything.  On machines
 449    which store all the registers in one fell swoop, this makes sure
 450    that REGISTERS contains all the registers from the program being
 451    debugged.  */
 452
 453 #define target_prepare_to_store()       \
 454      (*current_target.to_prepare_to_store) ()
 455
 456 extern DCACHE *target_dcache;
 457
 458 extern int do_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
 459                            struct mem_attrib *attrib);
 460
 461 extern int target_read_string (CORE_ADDR, char **, int, int *);
 462
 463 extern int target_read_memory (CORE_ADDR memaddr, char *myaddr, int len);
 464
 465 extern int target_write_memory (CORE_ADDR memaddr, char *myaddr, int len);
 466
 467 extern int xfer_memory (CORE_ADDR, char *, int, int,
 468                         struct mem_attrib *, struct target_ops *);
 469
 470 extern int child_xfer_memory (CORE_ADDR, char *, int, int,
 471                               struct mem_attrib *, struct target_ops *);
 472
 473 /* Make a single attempt at transfering LEN bytes.  On a successful
 474    transfer, the number of bytes actually transfered is returned and
 475    ERR is set to 0.  When a transfer fails, -1 is returned (the number
 476    of bytes actually transfered is not defined) and ERR is set to a
 477    non-zero error indication.  */
 478
 479 extern int target_read_memory_partial (CORE_ADDR addr, char *buf, int len,
 480                                        int *err);
 481
 482 extern int target_write_memory_partial (CORE_ADDR addr, char *buf, int len,
 483                                         int *err);
 484
 485 extern char *child_pid_to_exec_file (int);
 486
 487 extern char *child_core_file_to_sym_file (char *);
 488
 489 #if defined(CHILD_POST_ATTACH)
 490 extern void child_post_attach (int);
 491 #endif
 492
 493 extern void child_post_wait (ptid_t, int);
 494
 495 extern void child_post_startup_inferior (ptid_t);
 496
 497 extern void child_acknowledge_created_inferior (int);
 498
 499 extern int child_insert_fork_catchpoint (int);
 500
 501 extern int child_remove_fork_catchpoint (int);
 502
 503 extern int child_insert_vfork_catchpoint (int);
 504
 505 extern int child_remove_vfork_catchpoint (int);
 506
 507 extern void child_acknowledge_created_inferior (int);
 508
 509 extern int child_follow_fork (int);
 510
 511 extern int child_insert_exec_catchpoint (int);
 512
 513 extern int child_remove_exec_catchpoint (int);
 514
 515 extern int child_reported_exec_events_per_exec_call (void);
 516
 517 extern int child_has_exited (int, int, int *);
 518
 519 extern int child_thread_alive (ptid_t);
 520
 521 /* From infrun.c.  */
 522
 523 extern int inferior_has_forked (int pid, int *child_pid);
 524
 525 extern int inferior_has_vforked (int pid, int *child_pid);
 526
 527 extern int inferior_has_execd (int pid, char **execd_pathname);
 528
 529 /* From exec.c */
 530
 531 extern void print_section_info (struct target_ops *, bfd *);
 532
 533 /* Print a line about the current target.  */
 534
 535 #define target_files_info()     \
 536      (*current_target.to_files_info) (&current_target)
 537
 538 /* Insert a breakpoint at address ADDR in the target machine.  SAVE is
 539    a pointer to memory allocated for saving the target contents.  It
 540    is guaranteed by the caller to be long enough to save the number of
 541    breakpoint bytes indicated by BREAKPOINT_FROM_PC.  Result is 0 for
 542    success, or an errno value.  */
 543
 544 #define target_insert_breakpoint(addr, save)    \
 545      (*current_target.to_insert_breakpoint) (addr, save)
 546
 547 /* Remove a breakpoint at address ADDR in the target machine.
 548    SAVE is a pointer to the same save area
 549    that was previously passed to target_insert_breakpoint.
 550    Result is 0 for success, or an errno value.  */
 551
 552 #define target_remove_breakpoint(addr, save)    \
 553      (*current_target.to_remove_breakpoint) (addr, save)
 554
 555 /* Initialize the terminal settings we record for the inferior,
 556    before we actually run the inferior.  */
 557
 558 #define target_terminal_init() \
 559      (*current_target.to_terminal_init) ()
 560
 561 /* Put the inferior's terminal settings into effect.
 562    This is preparation for starting or resuming the inferior.  */
 563
 564 #define target_terminal_inferior() \
 565      (*current_target.to_terminal_inferior) ()
 566
 567 /* Put some of our terminal settings into effect,
 568    enough to get proper results from our output,
 569    but do not change into or out of RAW mode
 570    so that no input is discarded.
 571
 572    After doing this, either terminal_ours or terminal_inferior
 573    should be called to get back to a normal state of affairs.  */
 574
 575 #define target_terminal_ours_for_output() \
 576      (*current_target.to_terminal_ours_for_output) ()
 577
 578 /* Put our terminal settings into effect.
 579    First record the inferior's terminal settings
 580    so they can be restored properly later.  */
 581
 582 #define target_terminal_ours() \
 583      (*current_target.to_terminal_ours) ()
 584
 585 /* Save our terminal settings.
 586    This is called from TUI after entering or leaving the curses
 587    mode.  Since curses modifies our terminal this call is here
 588    to take this change into account.  */
 589
 590 #define target_terminal_save_ours() \
 591      (*current_target.to_terminal_save_ours) ()
 592
 593 /* Print useful information about our terminal status, if such a thing
 594    exists.  */
 595
 596 #define target_terminal_info(arg, from_tty) \
 597      (*current_target.to_terminal_info) (arg, from_tty)
 598
 599 /* Kill the inferior process.   Make it go away.  */
 600
 601 #define target_kill() \
 602      (*current_target.to_kill) ()
 603
 604 /* Load an executable file into the target process.  This is expected
 605    to not only bring new code into the target process, but also to
 606    update GDB's symbol tables to match.  */
 607
 608 extern void target_load (char *arg, int from_tty);
 609
 610 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 611    name.  ADDRP is a CORE_ADDR * pointing to where the value of the
 612    symbol should be returned.  The result is 0 if successful, nonzero
 613    if the symbol does not exist in the target environment.  This
 614    function should not call error() if communication with the target
 615    is interrupted, since it is called from symbol reading, but should
 616    return nonzero, possibly doing a complain().  */
 617
 618 #define target_lookup_symbol(name, addrp) \
 619      (*current_target.to_lookup_symbol) (name, addrp)
 620
 621 /* Start an inferior process and set inferior_ptid to its pid.
 622    EXEC_FILE is the file to run.
 623    ALLARGS is a string containing the arguments to the program.
 624    ENV is the environment vector to pass.  Errors reported with error().
 625    On VxWorks and various standalone systems, we ignore exec_file.  */
 626
 627 #define target_create_inferior(exec_file, args, env)    \
 628      (*current_target.to_create_inferior) (exec_file, args, env)
 629
 630
 631 /* Some targets (such as ttrace-based HPUX) don't allow us to request
 632    notification of inferior events such as fork and vork immediately
 633    after the inferior is created.  (This because of how gdb gets an
 634    inferior created via invoking a shell to do it.  In such a scenario,
 635    if the shell init file has commands in it, the shell will fork and
 636    exec for each of those commands, and we will see each such fork
 637    event.  Very bad.)
 638
 639    Such targets will supply an appropriate definition for this function.  */
 640
 641 #define target_post_startup_inferior(ptid) \
 642      (*current_target.to_post_startup_inferior) (ptid)
 643
 644 /* On some targets, the sequence of starting up an inferior requires
 645    some synchronization between gdb and the new inferior process, PID.  */
 646
 647 #define target_acknowledge_created_inferior(pid) \
 648      (*current_target.to_acknowledge_created_inferior) (pid)
 649
 650 /* On some targets, we can catch an inferior fork or vfork event when
 651    it occurs.  These functions insert/remove an already-created
 652    catchpoint for such events.  */
 653
 654 #define target_insert_fork_catchpoint(pid) \
 655      (*current_target.to_insert_fork_catchpoint) (pid)
 656
 657 #define target_remove_fork_catchpoint(pid) \
 658      (*current_target.to_remove_fork_catchpoint) (pid)
 659
 660 #define target_insert_vfork_catchpoint(pid) \
 661      (*current_target.to_insert_vfork_catchpoint) (pid)
 662
 663 #define target_remove_vfork_catchpoint(pid) \
 664      (*current_target.to_remove_vfork_catchpoint) (pid)
 665
 666 /* If the inferior forks or vforks, this function will be called at
 667    the next resume in order to perform any bookkeeping and fiddling
 668    necessary to continue debugging either the parent or child, as
 669    requested, and releasing the other.  Information about the fork
 670    or vfork event is available via get_last_target_status ().
 671    This function returns 1 if the inferior should not be resumed
 672    (i.e. there is another event pending).  */
 673
 674 #define target_follow_fork(follow_child) \
 675      (*current_target.to_follow_fork) (follow_child)
 676
 677 /* On some targets, we can catch an inferior exec event when it
 678    occurs.  These functions insert/remove an already-created
 679    catchpoint for such events.  */
 680
 681 #define target_insert_exec_catchpoint(pid) \
 682      (*current_target.to_insert_exec_catchpoint) (pid)
 683
 684 #define target_remove_exec_catchpoint(pid) \
 685      (*current_target.to_remove_exec_catchpoint) (pid)
 686
 687 /* Returns the number of exec events that are reported when a process
 688    invokes a flavor of the exec() system call on this target, if exec
 689    events are being reported.  */
 690
 691 #define target_reported_exec_events_per_exec_call() \
 692      (*current_target.to_reported_exec_events_per_exec_call) ()
 693
 694 /* Returns TRUE if PID has exited.  And, also sets EXIT_STATUS to the
 695    exit code of PID, if any.  */
 696
 697 #define target_has_exited(pid,wait_status,exit_status) \
 698      (*current_target.to_has_exited) (pid,wait_status,exit_status)
 699
 700 /* The debugger has completed a blocking wait() call.  There is now
 701    some process event that must be processed.  This function should
 702    be defined by those targets that require the debugger to perform
 703    cleanup or internal state changes in response to the process event.  */
 704
 705 /* The inferior process has died.  Do what is right.  */
 706
 707 #define target_mourn_inferior() \
 708      (*current_target.to_mourn_inferior) ()
 709
 710 /* Does target have enough data to do a run or attach command? */
 711
 712 #define target_can_run(t) \
 713      ((t)->to_can_run) ()
 714
 715 /* post process changes to signal handling in the inferior.  */
 716
 717 #define target_notice_signals(ptid) \
 718      (*current_target.to_notice_signals) (ptid)
 719
 720 /* Check to see if a thread is still alive.  */
 721
 722 #define target_thread_alive(ptid) \
 723      (*current_target.to_thread_alive) (ptid)
 724
 725 /* Query for new threads and add them to the thread list.  */
 726
 727 #define target_find_new_threads() \
 728      (*current_target.to_find_new_threads) (); \
 729
 730 /* Make target stop in a continuable fashion.  (For instance, under
 731    Unix, this should act like SIGSTOP).  This function is normally
 732    used by GUIs to implement a stop button.  */
 733
 734 #define target_stop current_target.to_stop
 735
 736 /* Queries the target side for some information.  The first argument is a
 737    letter specifying the type of the query, which is used to determine who
 738    should process it.  The second argument is a string that specifies which
 739    information is desired and the third is a buffer that carries back the
 740    response from the target side. The fourth parameter is the size of the
 741    output buffer supplied.  */
 742
 743 #define target_query(query_type, query, resp_buffer, bufffer_size)      \
 744      (*current_target.to_query) (query_type, query, resp_buffer, bufffer_size)
 745
 746 /* Send the specified COMMAND to the target's monitor
 747    (shell,interpreter) for execution.  The result of the query is
 748    placed in OUTBUF.  */
 749
 750 #define target_rcmd(command, outbuf) \
 751      (*current_target.to_rcmd) (command, outbuf)
 752
 753
 754 /* Get the symbol information for a breakpointable routine called when
 755    an exception event occurs.
 756    Intended mainly for C++, and for those
 757    platforms/implementations where such a callback mechanism is available,
 758    e.g. HP-UX with ANSI C++ (aCC).  Some compilers (e.g. g++) support
 759    different mechanisms for debugging exceptions.  */
 760
 761 #define target_enable_exception_callback(kind, enable) \
 762      (*current_target.to_enable_exception_callback) (kind, enable)
 763
 764 /* Get the current exception event kind -- throw or catch, etc.  */
 765
 766 #define target_get_current_exception_event() \
 767      (*current_target.to_get_current_exception_event) ()
 768
 769 /* Does the target include all of memory, or only part of it?  This
 770    determines whether we look up the target chain for other parts of
 771    memory if this target can't satisfy a request.  */
 772
 773 #define target_has_all_memory   \
 774      (current_target.to_has_all_memory)
 775
 776 /* Does the target include memory?  (Dummy targets don't.)  */
 777
 778 #define target_has_memory       \
 779      (current_target.to_has_memory)
 780
 781 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 782    we start a process.)  */
 783
 784 #define target_has_stack        \
 785      (current_target.to_has_stack)
 786
 787 /* Does the target have registers?  (Exec files don't.)  */
 788
 789 #define target_has_registers    \
 790      (current_target.to_has_registers)
 791
 792 /* Does the target have execution?  Can we make it jump (through
 793    hoops), or pop its stack a few times?  FIXME: If this is to work that
 794    way, it needs to check whether an inferior actually exists.
 795    remote-udi.c and probably other targets can be the current target
 796    when the inferior doesn't actually exist at the moment.  Right now
 797    this just tells us whether this target is *capable* of execution.  */
 798
 799 #define target_has_execution    \
 800      (current_target.to_has_execution)
 801
 802 /* Can the target support the debugger control of thread execution?
 803    a) Can it lock the thread scheduler?
 804    b) Can it switch the currently running thread?  */
 805
 806 #define target_can_lock_scheduler \
 807      (current_target.to_has_thread_control & tc_schedlock)
 808
 809 #define target_can_switch_threads \
 810      (current_target.to_has_thread_control & tc_switch)
 811
 812 /* Can the target support asynchronous execution? */
 813 #define target_can_async_p() (current_target.to_can_async_p ())
 814
 815 /* Is the target in asynchronous execution mode? */
 816 #define target_is_async_p() (current_target.to_is_async_p())
 817
 818 /* Put the target in async mode with the specified callback function. */
 819 #define target_async(CALLBACK,CONTEXT) \
 820      (current_target.to_async((CALLBACK), (CONTEXT)))
 821
 822 /* This is to be used ONLY within call_function_by_hand(). It provides
 823    a workaround, to have inferior function calls done in sychronous
 824    mode, even though the target is asynchronous. After
 825    target_async_mask(0) is called, calls to target_can_async_p() will
 826    return FALSE , so that target_resume() will not try to start the
 827    target asynchronously. After the inferior stops, we IMMEDIATELY
 828    restore the previous nature of the target, by calling
 829    target_async_mask(1). After that, target_can_async_p() will return
 830    TRUE. ANY OTHER USE OF THIS FEATURE IS DEPRECATED.
 831
 832    FIXME ezannoni 1999-12-13: we won't need this once we move
 833    the turning async on and off to the single execution commands,
 834    from where it is done currently, in remote_resume().  */
 835
 836 #define target_async_mask_value \
 837      (current_target.to_async_mask_value)
 838
 839 extern int target_async_mask (int mask);
 840
 841 extern void target_link (char *, CORE_ADDR *);
 842
 843 /* Converts a process id to a string.  Usually, the string just contains
 844    `process xyz', but on some systems it may contain
 845    `process xyz thread abc'.  */
 846
 847 #undef target_pid_to_str
 848 #define target_pid_to_str(PID) current_target.to_pid_to_str (PID)
 849
 850 #ifndef target_tid_to_str
 851 #define target_tid_to_str(PID) \
 852      target_pid_to_str (PID)
 853 extern char *normal_pid_to_str (ptid_t ptid);
 854 #endif
 855
 856 /* Return a short string describing extra information about PID,
 857    e.g. "sleeping", "runnable", "running on LWP 3".  Null return value
 858    is okay.  */
 859
 860 #define target_extra_thread_info(TP) \
 861      (current_target.to_extra_thread_info (TP))
 862
 863 /*
 864  * New Objfile Event Hook:
 865  *
 866  * Sometimes a GDB component wants to get notified whenever a new
 867  * objfile is loaded.  Mainly this is used by thread-debugging
 868  * implementations that need to know when symbols for the target
 869  * thread implemenation are available.
 870  *
 871  * The old way of doing this is to define a macro 'target_new_objfile'
 872  * that points to the function that you want to be called on every
 873  * objfile/shlib load.
 874  *
 875  * The new way is to grab the function pointer, 'target_new_objfile_hook',
 876  * and point it to the function that you want to be called on every
 877  * objfile/shlib load.
 878  *
 879  * If multiple clients are willing to be cooperative, they can each
 880  * save a pointer to the previous value of target_new_objfile_hook
 881  * before modifying it, and arrange for their function to call the
 882  * previous function in the chain.  In that way, multiple clients
 883  * can receive this notification (something like with signal handlers).
 884  */
 885
 886 extern void (*target_new_objfile_hook) (struct objfile *);
 887
 888 #ifndef target_pid_or_tid_to_str
 889 #define target_pid_or_tid_to_str(ID) \
 890      target_pid_to_str (ID)
 891 #endif
 892
 893 /* Attempts to find the pathname of the executable file
 894    that was run to create a specified process.
 895
 896    The process PID must be stopped when this operation is used.
 897
 898    If the executable file cannot be determined, NULL is returned.
 899
 900    Else, a pointer to a character string containing the pathname
 901    is returned.  This string should be copied into a buffer by
 902    the client if the string will not be immediately used, or if
 903    it must persist.  */
 904
 905 #define target_pid_to_exec_file(pid) \
 906      (current_target.to_pid_to_exec_file) (pid)
 907
 908 /*
 909  * Iterator function for target memory regions.
 910  * Calls a callback function once for each memory region 'mapped'
 911  * in the child process.  Defined as a simple macro rather than
 912  * as a function macro so that it can be tested for nullity.
 913  */
 914
 915 #define target_find_memory_regions(FUNC, DATA) \
 916      (current_target.to_find_memory_regions) (FUNC, DATA)
 917
 918 /*
 919  * Compose corefile .note section.
 920  */
 921
 922 #define target_make_corefile_notes(BFD, SIZE_P) \
 923      (current_target.to_make_corefile_notes) (BFD, SIZE_P)
 924
 925 /* Thread-local values.  */
 926 #define target_get_thread_local_address \
 927     (current_target.to_get_thread_local_address)
 928 #define target_get_thread_local_address_p() \
 929     (target_get_thread_local_address != NULL)
 930
 931 /* Hook to call target dependent code just after inferior target process has
 932    started.  */
 933
 934 #ifndef TARGET_CREATE_INFERIOR_HOOK
 935 #define TARGET_CREATE_INFERIOR_HOOK(PID)
 936 #endif
 937
 938 /* Hardware watchpoint interfaces.  */
 939
 940 /* Returns non-zero if we were stopped by a hardware watchpoint (memory read or
 941    write).  */
 942
 943 #ifndef STOPPED_BY_WATCHPOINT
 944 #define STOPPED_BY_WATCHPOINT(w) \
 945    (*current_target.to_stopped_by_watchpoint) ()
 946 #endif
 947
 948 /* Non-zero if we have continuable watchpoints  */
 949
 950 #ifndef HAVE_CONTINUABLE_WATCHPOINT
 951 #define HAVE_CONTINUABLE_WATCHPOINT \
 952    (current_target.to_have_continuable_watchpoint)
 953 #endif
 954
 955 /* HP-UX supplies these operations, which respectively disable and enable
 956    the memory page-protections that are used to implement hardware watchpoints
 957    on that platform.  See wait_for_inferior's use of these.  */
 958
 959 #if !defined(TARGET_DISABLE_HW_WATCHPOINTS)
 960 #define TARGET_DISABLE_HW_WATCHPOINTS(pid)
 961 #endif
 962
 963 #if !defined(TARGET_ENABLE_HW_WATCHPOINTS)
 964 #define TARGET_ENABLE_HW_WATCHPOINTS(pid)
 965 #endif
 966
 967 /* Provide defaults for hardware watchpoint functions.  */
 968
 969 /* If the *_hw_beakpoint functions have not been defined
 970    elsewhere use the definitions in the target vector.  */
 971
 972 /* Returns non-zero if we can set a hardware watchpoint of type TYPE.  TYPE is
 973    one of bp_hardware_watchpoint, bp_read_watchpoint, bp_write_watchpoint, or
 974    bp_hardware_breakpoint.  CNT is the number of such watchpoints used so far
 975    (including this one?).  OTHERTYPE is who knows what...  */
 976
 977 #ifndef TARGET_CAN_USE_HARDWARE_WATCHPOINT
 978 #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(TYPE,CNT,OTHERTYPE) \
 979  (*current_target.to_can_use_hw_breakpoint) (TYPE, CNT, OTHERTYPE);
 980 #endif
 981
 982 #if !defined(TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT)
 983 #define TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT(byte_count) \
 984     (*current_target.to_region_size_ok_for_hw_watchpoint) (byte_count)
 985 #endif
 986
 987
 988 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.  TYPE is 0
 989    for write, 1 for read, and 2 for read/write accesses.  Returns 0 for
 990    success, non-zero for failure.  */
 991
 992 #ifndef target_insert_watchpoint
 993 #define target_insert_watchpoint(addr, len, type)       \
 994      (*current_target.to_insert_watchpoint) (addr, len, type)
 995
 996 #define target_remove_watchpoint(addr, len, type)       \
 997      (*current_target.to_remove_watchpoint) (addr, len, type)
 998 #endif
 999
1000 #ifndef target_insert_hw_breakpoint
1001 #define target_insert_hw_breakpoint(addr, save) \
1002      (*current_target.to_insert_hw_breakpoint) (addr, save)
1003
1004 #define target_remove_hw_breakpoint(addr, save) \
1005      (*current_target.to_remove_hw_breakpoint) (addr, save)
1006 #endif
1007
1008 #ifndef target_stopped_data_address
1009 #define target_stopped_data_address() \
1010     (*current_target.to_stopped_data_address) ()
1011 #endif
1012
1013 /* If defined, then we need to decr pc by this much after a hardware break-
1014    point.  Presumably this overrides DECR_PC_AFTER_BREAK...  */
1015
1016 #ifndef DECR_PC_AFTER_HW_BREAK
1017 #define DECR_PC_AFTER_HW_BREAK 0
1018 #endif
1019
1020 /* Sometimes gdb may pick up what appears to be a valid target address
1021    from a minimal symbol, but the value really means, essentially,
1022    "This is an index into a table which is populated when the inferior
1023    is run.  Therefore, do not attempt to use this as a PC."  */
1024
1025 #if !defined(PC_REQUIRES_RUN_BEFORE_USE)
1026 #define PC_REQUIRES_RUN_BEFORE_USE(pc) (0)
1027 #endif
1028
1029 /* This will only be defined by a target that supports catching vfork events,
1030    such as HP-UX.
1031
1032    On some targets (such as HP-UX 10.20 and earlier), resuming a newly vforked
1033    child process after it has exec'd, causes the parent process to resume as
1034    well.  To prevent the parent from running spontaneously, such targets should
1035    define this to a function that prevents that from happening.  */
1036 #if !defined(ENSURE_VFORKING_PARENT_REMAINS_STOPPED)
1037 #define ENSURE_VFORKING_PARENT_REMAINS_STOPPED(PID) (0)
1038 #endif
1039
1040 /* This will only be defined by a target that supports catching vfork events,
1041    such as HP-UX.
1042
1043    On some targets (such as HP-UX 10.20 and earlier), a newly vforked child
1044    process must be resumed when it delivers its exec event, before the parent
1045    vfork event will be delivered to us.  */
1046
1047 #if !defined(RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK)
1048 #define RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK() (0)
1049 #endif
1050
1051 /* Routines for maintenance of the target structures...
1052
1053    add_target:   Add a target to the list of all possible targets.
1054
1055    push_target:  Make this target the top of the stack of currently used
1056    targets, within its particular stratum of the stack.  Result
1057    is 0 if now atop the stack, nonzero if not on top (maybe
1058    should warn user).
1059
1060    unpush_target: Remove this from the stack of currently used targets,
1061    no matter where it is on the list.  Returns 0 if no
1062    change, 1 if removed from stack.
1063
1064    pop_target:   Remove the top thing on the stack of current targets.  */
1065
1066 extern void add_target (struct target_ops *);
1067
1068 extern int push_target (struct target_ops *);
1069
1070 extern int unpush_target (struct target_ops *);
1071
1072 extern void target_preopen (int);
1073
1074 extern void pop_target (void);
1075
1076 /* Struct section_table maps address ranges to file sections.  It is
1077    mostly used with BFD files, but can be used without (e.g. for handling
1078    raw disks, or files not in formats handled by BFD).  */
1079
1080 struct section_table
1081   {
1082     CORE_ADDR addr;             /* Lowest address in section */
1083     CORE_ADDR endaddr;          /* 1+highest address in section */
1084
1085     sec_ptr the_bfd_section;
1086
1087     bfd *bfd;                   /* BFD file pointer */
1088   };
1089
1090 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
1091    Returns 0 if OK, 1 on error.  */
1092
1093 extern int build_section_table (bfd *, struct section_table **,
1094                                 struct section_table **);
1095
1096 /* From mem-break.c */
1097
1098 extern int memory_remove_breakpoint (CORE_ADDR, char *);
1099
1100 extern int memory_insert_breakpoint (CORE_ADDR, char *);
1101
1102 extern int default_memory_remove_breakpoint (CORE_ADDR, char *);
1103
1104 extern int default_memory_insert_breakpoint (CORE_ADDR, char *);
1105
1106
1107 /* From target.c */
1108
1109 extern void initialize_targets (void);
1110
1111 extern void noprocess (void);
1112
1113 extern void find_default_attach (char *, int);
1114
1115 extern void find_default_create_inferior (char *, char *, char **);
1116
1117 extern struct target_ops *find_run_target (void);
1118
1119 extern struct target_ops *find_core_target (void);
1120
1121 extern struct target_ops *find_target_beneath (struct target_ops *);
1122
1123 extern int target_resize_to_sections (struct target_ops *target,
1124                                       int num_added);
1125
1126 extern void remove_target_sections (bfd *abfd);
1127
1128 \f
1129 /* Stuff that should be shared among the various remote targets.  */
1130
1131 /* Debugging level.  0 is off, and non-zero values mean to print some debug
1132    information (higher values, more information).  */
1133 extern int remote_debug;
1134
1135 /* Speed in bits per second, or -1 which means don't mess with the speed.  */
1136 extern int baud_rate;
1137 /* Timeout limit for response from target. */
1138 extern int remote_timeout;
1139
1140 \f
1141 /* Functions for helping to write a native target.  */
1142
1143 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
1144 extern void store_waitstatus (struct target_waitstatus *, int);
1145
1146 /* Predicate to target_signal_to_host(). Return non-zero if the enum
1147    targ_signal SIGNO has an equivalent ``host'' representation.  */
1148 /* FIXME: cagney/1999-11-22: The name below was chosen in preference
1149    to the shorter target_signal_p() because it is far less ambigious.
1150    In this context ``target_signal'' refers to GDB's internal
1151    representation of the target's set of signals while ``host signal''
1152    refers to the target operating system's signal.  Confused?  */
1153
1154 extern int target_signal_to_host_p (enum target_signal signo);
1155
1156 /* Convert between host signal numbers and enum target_signal's.
1157    target_signal_to_host() returns 0 and prints a warning() on GDB's
1158    console if SIGNO has no equivalent host representation.  */
1159 /* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
1160    refering to the target operating system's signal numbering.
1161    Similarly, ``enum target_signal'' is named incorrectly, ``enum
1162    gdb_signal'' would probably be better as it is refering to GDB's
1163    internal representation of a target operating system's signal.  */
1164
1165 extern enum target_signal target_signal_from_host (int);
1166 extern int target_signal_to_host (enum target_signal);
1167
1168 /* Convert from a number used in a GDB command to an enum target_signal.  */
1169 extern enum target_signal target_signal_from_command (int);
1170
1171 /* Any target can call this to switch to remote protocol (in remote.c). */
1172 extern void push_remote_target (char *name, int from_tty);
1173 \f
1174 /* Imported from machine dependent code */
1175
1176 /* Blank target vector entries are initialized to target_ignore. */
1177 void target_ignore (void);
1178
1179 #endif /* !defined (TARGET_H) */