xref: /openbsd/gnu/usr.bin/binutils/gdb/target.h (revision 63addd46)
1 /* Interface between GDB and target environments, including files and processes
2 
3    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4    1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 
6    Contributed by Cygnus Support.  Written by John Gilmore.
7 
8    This file is part of GDB.
9 
10    This program is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License as published by
12    the Free Software Foundation; either version 2 of the License, or
13    (at your option) any later version.
14 
15    This program is distributed in the hope that it will be useful,
16    but WITHOUT ANY WARRANTY; without even the implied warranty of
17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18    GNU General Public License for more details.
19 
20    You should have received a copy of the GNU General Public License
21    along with this program; if not, write to the Free Software
22    Foundation, Inc., 59 Temple Place - Suite 330,
23    Boston, MA 02111-1307, USA.  */
24 
25 #if !defined (TARGET_H)
26 #define TARGET_H
27 
28 struct objfile;
29 struct ui_file;
30 struct mem_attrib;
31 struct target_ops;
32 
33 /* This include file defines the interface between the main part
34    of the debugger, and the part which is target-specific, or
35    specific to the communications interface between us and the
36    target.
37 
38    A TARGET is an interface between the debugger and a particular
39    kind of file or process.  Targets can be STACKED in STRATA,
40    so that more than one target can potentially respond to a request.
41    In particular, memory accesses will walk down the stack of targets
42    until they find a target that is interested in handling that particular
43    address.  STRATA are artificial boundaries on the stack, within
44    which particular kinds of targets live.  Strata exist so that
45    people don't get confused by pushing e.g. a process target and then
46    a file target, and wondering why they can't see the current values
47    of variables any more (the file target is handling them and they
48    never get to the process target).  So when you push a file target,
49    it goes into the file stratum, which is always below the process
50    stratum.  */
51 
52 #include "bfd.h"
53 #include "symtab.h"
54 #include "dcache.h"
55 #include "memattr.h"
56 
57 enum strata
58   {
59     dummy_stratum,		/* The lowest of the low */
60     file_stratum,		/* Executable files, etc */
61     core_stratum,		/* Core dump files */
62     download_stratum,		/* Downloading of remote targets */
63     process_stratum,		/* Executing processes */
64     thread_stratum		/* Executing threads */
65   };
66 
67 enum thread_control_capabilities
68   {
69     tc_none = 0,		/* Default: can't control thread execution.  */
70     tc_schedlock = 1,		/* Can lock the thread scheduler.  */
71     tc_switch = 2		/* Can switch the running thread on demand.  */
72   };
73 
74 /* Stuff for target_wait.  */
75 
76 /* Generally, what has the program done?  */
77 enum target_waitkind
78   {
79     /* The program has exited.  The exit status is in value.integer.  */
80     TARGET_WAITKIND_EXITED,
81 
82     /* The program has stopped with a signal.  Which signal is in
83        value.sig.  */
84     TARGET_WAITKIND_STOPPED,
85 
86     /* The program has terminated with a signal.  Which signal is in
87        value.sig.  */
88     TARGET_WAITKIND_SIGNALLED,
89 
90     /* The program is letting us know that it dynamically loaded something
91        (e.g. it called load(2) on AIX).  */
92     TARGET_WAITKIND_LOADED,
93 
94     /* The program has forked.  A "related" process' ID is in
95        value.related_pid.  I.e., if the child forks, value.related_pid
96        is the parent's ID.  */
97 
98     TARGET_WAITKIND_FORKED,
99 
100     /* The program has vforked.  A "related" process's ID is in
101        value.related_pid.  */
102 
103     TARGET_WAITKIND_VFORKED,
104 
105     /* The program has exec'ed a new executable file.  The new file's
106        pathname is pointed to by value.execd_pathname.  */
107 
108     TARGET_WAITKIND_EXECD,
109 
110     /* The program has entered or returned from a system call.  On
111        HP-UX, this is used in the hardware watchpoint implementation.
112        The syscall's unique integer ID number is in value.syscall_id */
113 
114     TARGET_WAITKIND_SYSCALL_ENTRY,
115     TARGET_WAITKIND_SYSCALL_RETURN,
116 
117     /* Nothing happened, but we stopped anyway.  This perhaps should be handled
118        within target_wait, but I'm not sure target_wait should be resuming the
119        inferior.  */
120     TARGET_WAITKIND_SPURIOUS,
121 
122     /* An event has occured, but we should wait again.
123        Remote_async_wait() returns this when there is an event
124        on the inferior, but the rest of the world is not interested in
125        it. The inferior has not stopped, but has just sent some output
126        to the console, for instance. In this case, we want to go back
127        to the event loop and wait there for another event from the
128        inferior, rather than being stuck in the remote_async_wait()
129        function. This way the event loop is responsive to other events,
130        like for instance the user typing.  */
131     TARGET_WAITKIND_IGNORE
132   };
133 
134 struct target_waitstatus
135   {
136     enum target_waitkind kind;
137 
138     /* Forked child pid, execd pathname, exit status or signal number.  */
139     union
140       {
141 	int integer;
142 	enum target_signal sig;
143 	int related_pid;
144 	char *execd_pathname;
145 	int syscall_id;
146       }
147     value;
148   };
149 
150 /* Possible types of events that the inferior handler will have to
151    deal with.  */
152 enum inferior_event_type
153   {
154     /* There is a request to quit the inferior, abandon it.  */
155     INF_QUIT_REQ,
156     /* Process a normal inferior event which will result in target_wait
157        being called.  */
158     INF_REG_EVENT,
159     /* Deal with an error on the inferior.  */
160     INF_ERROR,
161     /* We are called because a timer went off.  */
162     INF_TIMER,
163     /* We are called to do stuff after the inferior stops.  */
164     INF_EXEC_COMPLETE,
165     /* We are called to do some stuff after the inferior stops, but we
166        are expected to reenter the proceed() and
167        handle_inferior_event() functions. This is used only in case of
168        'step n' like commands.  */
169     INF_EXEC_CONTINUE
170   };
171 
172 /* Return the string for a signal.  */
173 extern char *target_signal_to_string (enum target_signal);
174 
175 /* Return the name (SIGHUP, etc.) for a signal.  */
176 extern char *target_signal_to_name (enum target_signal);
177 
178 /* Given a name (SIGHUP, etc.), return its signal.  */
179 enum target_signal target_signal_from_name (char *);
180 
181 /* Request the transfer of up to LEN 8-bit bytes of the target's
182    OBJECT.  The OFFSET, for a seekable object, specifies the starting
183    point.  The ANNEX can be used to provide additional data-specific
184    information to the target.
185 
186    Return the number of bytes actually transfered, zero when no
187    further transfer is possible, and -1 when the transfer is not
188    supported.
189 
190    NOTE: cagney/2003-10-17: The current interface does not support a
191    "retry" mechanism.  Instead it assumes that at least one byte will
192    be transfered on each call.
193 
194    NOTE: cagney/2003-10-17: The current interface can lead to
195    fragmented transfers.  Lower target levels should not implement
196    hacks, such as enlarging the transfer, in an attempt to compensate
197    for this.  Instead, the target stack should be extended so that it
198    implements supply/collect methods and a look-aside object cache.
199    With that available, the lowest target can safely and freely "push"
200    data up the stack.
201 
202    NOTE: cagney/2003-10-17: Unlike the old query and the memory
203    transfer mechanisms, these methods are explicitly parameterized by
204    the target that it should be applied to.
205 
206    NOTE: cagney/2003-10-17: Just like the old query and memory xfer
207    methods, these new methods perform partial transfers.  The only
208    difference is that these new methods thought to include "partial"
209    in the name.  The old code's failure to do this lead to much
210    confusion and duplication of effort as each target object attempted
211    to locally take responsibility for something it didn't have to
212    worry about.
213 
214    NOTE: cagney/2003-10-17: With a TARGET_OBJECT_KOD object, for
215    backward compatibility with the "target_query" method that this
216    replaced, when OFFSET and LEN are both zero, return the "minimum"
217    buffer size.  See "remote.c" for further information.  */
218 
219 enum target_object
220 {
221   /* Kernel Object Display transfer.  See "kod.c" and "remote.c".  */
222   TARGET_OBJECT_KOD,
223   /* AVR target specific transfer.  See "avr-tdep.c" and "remote.c".  */
224   TARGET_OBJECT_AVR,
225   /* Transfer up-to LEN bytes of memory starting at OFFSET.  */
226   TARGET_OBJECT_MEMORY,
227   /* Kernel Unwind Table.  See "ia64-tdep.c".  */
228   TARGET_OBJECT_UNWIND_TABLE,
229   /* Transfer auxilliary vector.  */
230   TARGET_OBJECT_AUXV,
231   /* StackGhost cookie.  See "sparc-tdep.c".  */
232   TARGET_OBJECT_WCOOKIE
233 
234   /* Possible future objects: TARGET_OBJECT_FILE, TARGET_OBJECT_PROC, ... */
235 };
236 
237 extern LONGEST target_read_partial (struct target_ops *ops,
238 				    enum target_object object,
239 				    const char *annex, void *buf,
240 				    ULONGEST offset, LONGEST len);
241 
242 extern LONGEST target_write_partial (struct target_ops *ops,
243 				     enum target_object object,
244 				     const char *annex, const void *buf,
245 				     ULONGEST offset, LONGEST len);
246 
247 /* Wrappers to perform the full transfer.  */
248 extern LONGEST target_read (struct target_ops *ops,
249 			    enum target_object object,
250 			    const char *annex, void *buf,
251 			    ULONGEST offset, LONGEST len);
252 
253 extern LONGEST target_write (struct target_ops *ops,
254 			     enum target_object object,
255 			     const char *annex, const void *buf,
256 			     ULONGEST offset, LONGEST len);
257 
258 /* Wrappers to target read/write that perform memory transfers.  They
259    throw an error if the memory transfer fails.
260 
261    NOTE: cagney/2003-10-23: The naming schema is lifted from
262    "frame.h".  The parameter order is lifted from get_frame_memory,
263    which in turn lifted it from read_memory.  */
264 
265 extern void get_target_memory (struct target_ops *ops, CORE_ADDR addr,
266 			       void *buf, LONGEST len);
267 extern ULONGEST get_target_memory_unsigned (struct target_ops *ops,
268 					    CORE_ADDR addr, int len);
269 
270 
271 /* If certain kinds of activity happen, target_wait should perform
272    callbacks.  */
273 /* Right now we just call (*TARGET_ACTIVITY_FUNCTION) if I/O is possible
274    on TARGET_ACTIVITY_FD.  */
275 extern int target_activity_fd;
276 /* Returns zero to leave the inferior alone, one to interrupt it.  */
277 extern int (*target_activity_function) (void);
278 
279 struct thread_info;		/* fwd decl for parameter list below: */
280 
281 struct target_ops
282   {
283     struct target_ops *beneath;	/* To the target under this one.  */
284     char *to_shortname;		/* Name this target type */
285     char *to_longname;		/* Name for printing */
286     char *to_doc;		/* Documentation.  Does not include trailing
287 				   newline, and starts with a one-line descrip-
288 				   tion (probably similar to to_longname).  */
289     /* Per-target scratch pad.  */
290     void *to_data;
291     /* The open routine takes the rest of the parameters from the
292        command, and (if successful) pushes a new target onto the
293        stack.  Targets should supply this routine, if only to provide
294        an error message.  */
295     void (*to_open) (char *, int);
296     /* Old targets with a static target vector provide "to_close".
297        New re-entrant targets provide "to_xclose" and that is expected
298        to xfree everything (including the "struct target_ops").  */
299     void (*to_xclose) (struct target_ops *targ, int quitting);
300     void (*to_close) (int);
301     void (*to_attach) (char *, int);
302     void (*to_post_attach) (int);
303     void (*to_detach) (char *, int);
304     void (*to_disconnect) (char *, int);
305     void (*to_resume) (ptid_t, int, enum target_signal);
306     ptid_t (*to_wait) (ptid_t, struct target_waitstatus *);
307     void (*to_fetch_registers) (int);
308     void (*to_store_registers) (int);
309     void (*to_prepare_to_store) (void);
310 
311     /* Transfer LEN bytes of memory between GDB address MYADDR and
312        target address MEMADDR.  If WRITE, transfer them to the target, else
313        transfer them from the target.  TARGET is the target from which we
314        get this function.
315 
316        Return value, N, is one of the following:
317 
318        0 means that we can't handle this.  If errno has been set, it is the
319        error which prevented us from doing it (FIXME: What about bfd_error?).
320 
321        positive (call it N) means that we have transferred N bytes
322        starting at MEMADDR.  We might be able to handle more bytes
323        beyond this length, but no promises.
324 
325        negative (call its absolute value N) means that we cannot
326        transfer right at MEMADDR, but we could transfer at least
327        something at MEMADDR + N.
328 
329        NOTE: cagney/2004-10-01: This has been entirely superseeded by
330        to_xfer_partial and inferior inheritance.  */
331 
332     int (*deprecated_xfer_memory) (CORE_ADDR memaddr, char *myaddr,
333 				   int len, int write,
334 				   struct mem_attrib *attrib,
335 				   struct target_ops *target);
336 
337     void (*to_files_info) (struct target_ops *);
338     int (*to_insert_breakpoint) (CORE_ADDR, char *);
339     int (*to_remove_breakpoint) (CORE_ADDR, char *);
340     int (*to_can_use_hw_breakpoint) (int, int, int);
341     int (*to_insert_hw_breakpoint) (CORE_ADDR, char *);
342     int (*to_remove_hw_breakpoint) (CORE_ADDR, char *);
343     int (*to_remove_watchpoint) (CORE_ADDR, int, int);
344     int (*to_insert_watchpoint) (CORE_ADDR, int, int);
345     int (*to_stopped_by_watchpoint) (void);
346     int to_have_continuable_watchpoint;
347     int (*to_stopped_data_address) (struct target_ops *, CORE_ADDR *);
348     int (*to_region_size_ok_for_hw_watchpoint) (int);
349     void (*to_terminal_init) (void);
350     void (*to_terminal_inferior) (void);
351     void (*to_terminal_ours_for_output) (void);
352     void (*to_terminal_ours) (void);
353     void (*to_terminal_save_ours) (void);
354     void (*to_terminal_info) (char *, int);
355     void (*to_kill) (void);
356     void (*to_load) (char *, int);
357     int (*to_lookup_symbol) (char *, CORE_ADDR *);
358     void (*to_create_inferior) (char *, char *, char **, int);
359     void (*to_post_startup_inferior) (ptid_t);
360     void (*to_acknowledge_created_inferior) (int);
361     int (*to_insert_fork_catchpoint) (int);
362     int (*to_remove_fork_catchpoint) (int);
363     int (*to_insert_vfork_catchpoint) (int);
364     int (*to_remove_vfork_catchpoint) (int);
365     int (*to_follow_fork) (int);
366     int (*to_insert_exec_catchpoint) (int);
367     int (*to_remove_exec_catchpoint) (int);
368     int (*to_reported_exec_events_per_exec_call) (void);
369     int (*to_has_exited) (int, int, int *);
370     void (*to_mourn_inferior) (void);
371     int (*to_can_run) (void);
372     void (*to_notice_signals) (ptid_t ptid);
373     int (*to_thread_alive) (ptid_t ptid);
374     void (*to_find_new_threads) (void);
375     char *(*to_pid_to_str) (ptid_t);
376     char *(*to_extra_thread_info) (struct thread_info *);
377     void (*to_stop) (void);
378     void (*to_rcmd) (char *command, struct ui_file *output);
379     struct symtab_and_line *(*to_enable_exception_callback) (enum
380 							     exception_event_kind,
381 							     int);
382     struct exception_event_record *(*to_get_current_exception_event) (void);
383     char *(*to_pid_to_exec_file) (int pid);
384     enum strata to_stratum;
385     int to_has_all_memory;
386     int to_has_memory;
387     int to_has_stack;
388     int to_has_registers;
389     int to_has_execution;
390     int to_has_thread_control;	/* control thread execution */
391     struct section_table
392      *to_sections;
393     struct section_table
394      *to_sections_end;
395     /* ASYNC target controls */
396     int (*to_can_async_p) (void);
397     int (*to_is_async_p) (void);
398     void (*to_async) (void (*cb) (enum inferior_event_type, void *context),
399 		      void *context);
400     int to_async_mask_value;
401     int (*to_find_memory_regions) (int (*) (CORE_ADDR,
402 					    unsigned long,
403 					    int, int, int,
404 					    void *),
405 				   void *);
406     char * (*to_make_corefile_notes) (bfd *, int *);
407 
408     /* Return the thread-local address at OFFSET in the
409        thread-local storage for the thread PTID and the shared library
410        or executable file given by OBJFILE.  If that block of
411        thread-local storage hasn't been allocated yet, this function
412        may return an error.  */
413     CORE_ADDR (*to_get_thread_local_address) (ptid_t ptid,
414 					      struct objfile *objfile,
415 					      CORE_ADDR offset);
416 
417     /* Perform partial transfers on OBJECT.  See target_read_partial
418        and target_write_partial for details of each variant.  One, and
419        only one, of readbuf or writebuf must be non-NULL.  */
420     LONGEST (*to_xfer_partial) (struct target_ops *ops,
421 				enum target_object object, const char *annex,
422 				void *readbuf, const void *writebuf,
423 				ULONGEST offset, LONGEST len);
424 
425     int to_magic;
426     /* Need sub-structure for target machine related rather than comm related?
427      */
428   };
429 
430 /* Magic number for checking ops size.  If a struct doesn't end with this
431    number, somebody changed the declaration but didn't change all the
432    places that initialize one.  */
433 
434 #define	OPS_MAGIC	3840
435 
436 /* The ops structure for our "current" target process.  This should
437    never be NULL.  If there is no target, it points to the dummy_target.  */
438 
439 extern struct target_ops current_target;
440 
441 /* Define easy words for doing these operations on our current target.  */
442 
443 #define	target_shortname	(current_target.to_shortname)
444 #define	target_longname		(current_target.to_longname)
445 
446 /* Does whatever cleanup is required for a target that we are no
447    longer going to be calling.  QUITTING indicates that GDB is exiting
448    and should not get hung on an error (otherwise it is important to
449    perform clean termination, even if it takes a while).  This routine
450    is automatically always called when popping the target off the
451    target stack (to_beneath is undefined).  Closing file descriptors
452    and freeing all memory allocated memory are typical things it
453    should do.  */
454 
455 void target_close (struct target_ops *targ, int quitting);
456 
457 /* Attaches to a process on the target side.  Arguments are as passed
458    to the `attach' command by the user.  This routine can be called
459    when the target is not on the target-stack, if the target_can_run
460    routine returns 1; in that case, it must push itself onto the stack.
461    Upon exit, the target should be ready for normal operations, and
462    should be ready to deliver the status of the process immediately
463    (without waiting) to an upcoming target_wait call.  */
464 
465 #define	target_attach(args, from_tty)	\
466      (*current_target.to_attach) (args, from_tty)
467 
468 /* The target_attach operation places a process under debugger control,
469    and stops the process.
470 
471    This operation provides a target-specific hook that allows the
472    necessary bookkeeping to be performed after an attach completes.  */
473 #define target_post_attach(pid) \
474      (*current_target.to_post_attach) (pid)
475 
476 /* Takes a program previously attached to and detaches it.
477    The program may resume execution (some targets do, some don't) and will
478    no longer stop on signals, etc.  We better not have left any breakpoints
479    in the program or it'll die when it hits one.  ARGS is arguments
480    typed by the user (e.g. a signal to send the process).  FROM_TTY
481    says whether to be verbose or not.  */
482 
483 extern void target_detach (char *, int);
484 
485 /* Disconnect from the current target without resuming it (leaving it
486    waiting for a debugger).  */
487 
488 extern void target_disconnect (char *, int);
489 
490 /* Resume execution of the target process PTID.  STEP says whether to
491    single-step or to run free; SIGGNAL is the signal to be given to
492    the target, or TARGET_SIGNAL_0 for no signal.  The caller may not
493    pass TARGET_SIGNAL_DEFAULT.  */
494 
495 #define	target_resume(ptid, step, siggnal)				\
496   do {									\
497     dcache_invalidate(target_dcache);					\
498     (*current_target.to_resume) (ptid, step, siggnal);			\
499   } while (0)
500 
501 /* Wait for process pid to do something.  PTID = -1 to wait for any
502    pid to do something.  Return pid of child, or -1 in case of error;
503    store status through argument pointer STATUS.  Note that it is
504    _NOT_ OK to throw_exception() out of target_wait() without popping
505    the debugging target from the stack; GDB isn't prepared to get back
506    to the prompt with a debugging target but without the frame cache,
507    stop_pc, etc., set up.  */
508 
509 #define	target_wait(ptid, status)		\
510      (*current_target.to_wait) (ptid, status)
511 
512 /* Fetch at least register REGNO, or all regs if regno == -1.  No result.  */
513 
514 #define	target_fetch_registers(regno)	\
515      (*current_target.to_fetch_registers) (regno)
516 
517 /* Store at least register REGNO, or all regs if REGNO == -1.
518    It can store as many registers as it wants to, so target_prepare_to_store
519    must have been previously called.  Calls error() if there are problems.  */
520 
521 #define	target_store_registers(regs)	\
522      (*current_target.to_store_registers) (regs)
523 
524 /* Get ready to modify the registers array.  On machines which store
525    individual registers, this doesn't need to do anything.  On machines
526    which store all the registers in one fell swoop, this makes sure
527    that REGISTERS contains all the registers from the program being
528    debugged.  */
529 
530 #define	target_prepare_to_store()	\
531      (*current_target.to_prepare_to_store) ()
532 
533 extern DCACHE *target_dcache;
534 
535 extern int do_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
536 			   struct mem_attrib *attrib);
537 
538 extern int target_read_string (CORE_ADDR, char **, int, int *);
539 
540 extern int target_read_memory (CORE_ADDR memaddr, char *myaddr, int len);
541 
542 extern int target_write_memory (CORE_ADDR memaddr, char *myaddr, int len);
543 
544 extern int xfer_memory (CORE_ADDR, char *, int, int,
545 			struct mem_attrib *, struct target_ops *);
546 
547 extern int child_xfer_memory (CORE_ADDR, char *, int, int,
548 			      struct mem_attrib *, struct target_ops *);
549 
550 /* Make a single attempt at transfering LEN bytes.  On a successful
551    transfer, the number of bytes actually transfered is returned and
552    ERR is set to 0.  When a transfer fails, -1 is returned (the number
553    of bytes actually transfered is not defined) and ERR is set to a
554    non-zero error indication.  */
555 
556 extern int target_read_memory_partial (CORE_ADDR addr, char *buf, int len,
557 				       int *err);
558 
559 extern int target_write_memory_partial (CORE_ADDR addr, char *buf, int len,
560 					int *err);
561 
562 extern char *child_pid_to_exec_file (int);
563 
564 extern char *child_core_file_to_sym_file (char *);
565 
566 #if defined(CHILD_POST_ATTACH)
567 extern void child_post_attach (int);
568 #endif
569 
570 extern void child_post_startup_inferior (ptid_t);
571 
572 extern void child_acknowledge_created_inferior (int);
573 
574 extern int child_insert_fork_catchpoint (int);
575 
576 extern int child_remove_fork_catchpoint (int);
577 
578 extern int child_insert_vfork_catchpoint (int);
579 
580 extern int child_remove_vfork_catchpoint (int);
581 
582 extern void child_acknowledge_created_inferior (int);
583 
584 extern int child_follow_fork (int);
585 
586 extern int child_insert_exec_catchpoint (int);
587 
588 extern int child_remove_exec_catchpoint (int);
589 
590 extern int child_reported_exec_events_per_exec_call (void);
591 
592 extern int child_has_exited (int, int, int *);
593 
594 extern int child_thread_alive (ptid_t);
595 
596 /* From infrun.c.  */
597 
598 extern int inferior_has_forked (int pid, int *child_pid);
599 
600 extern int inferior_has_vforked (int pid, int *child_pid);
601 
602 extern int inferior_has_execd (int pid, char **execd_pathname);
603 
604 /* From exec.c */
605 
606 extern void print_section_info (struct target_ops *, bfd *);
607 
608 /* Print a line about the current target.  */
609 
610 #define	target_files_info()	\
611      (*current_target.to_files_info) (&current_target)
612 
613 /* Insert a breakpoint at address ADDR in the target machine.  SAVE is
614    a pointer to memory allocated for saving the target contents.  It
615    is guaranteed by the caller to be long enough to save the number of
616    breakpoint bytes indicated by BREAKPOINT_FROM_PC.  Result is 0 for
617    success, or an errno value.  */
618 
619 #define	target_insert_breakpoint(addr, save)	\
620      (*current_target.to_insert_breakpoint) (addr, save)
621 
622 /* Remove a breakpoint at address ADDR in the target machine.
623    SAVE is a pointer to the same save area
624    that was previously passed to target_insert_breakpoint.
625    Result is 0 for success, or an errno value.  */
626 
627 #define	target_remove_breakpoint(addr, save)	\
628      (*current_target.to_remove_breakpoint) (addr, save)
629 
630 /* Initialize the terminal settings we record for the inferior,
631    before we actually run the inferior.  */
632 
633 #define target_terminal_init() \
634      (*current_target.to_terminal_init) ()
635 
636 /* Put the inferior's terminal settings into effect.
637    This is preparation for starting or resuming the inferior.  */
638 
639 #define target_terminal_inferior() \
640      (*current_target.to_terminal_inferior) ()
641 
642 /* Put some of our terminal settings into effect,
643    enough to get proper results from our output,
644    but do not change into or out of RAW mode
645    so that no input is discarded.
646 
647    After doing this, either terminal_ours or terminal_inferior
648    should be called to get back to a normal state of affairs.  */
649 
650 #define target_terminal_ours_for_output() \
651      (*current_target.to_terminal_ours_for_output) ()
652 
653 /* Put our terminal settings into effect.
654    First record the inferior's terminal settings
655    so they can be restored properly later.  */
656 
657 #define target_terminal_ours() \
658      (*current_target.to_terminal_ours) ()
659 
660 /* Save our terminal settings.
661    This is called from TUI after entering or leaving the curses
662    mode.  Since curses modifies our terminal this call is here
663    to take this change into account.  */
664 
665 #define target_terminal_save_ours() \
666      (*current_target.to_terminal_save_ours) ()
667 
668 /* Print useful information about our terminal status, if such a thing
669    exists.  */
670 
671 #define target_terminal_info(arg, from_tty) \
672      (*current_target.to_terminal_info) (arg, from_tty)
673 
674 /* Kill the inferior process.   Make it go away.  */
675 
676 #define target_kill() \
677      (*current_target.to_kill) ()
678 
679 /* Load an executable file into the target process.  This is expected
680    to not only bring new code into the target process, but also to
681    update GDB's symbol tables to match.  */
682 
683 extern void target_load (char *arg, int from_tty);
684 
685 /* Look up a symbol in the target's symbol table.  NAME is the symbol
686    name.  ADDRP is a CORE_ADDR * pointing to where the value of the
687    symbol should be returned.  The result is 0 if successful, nonzero
688    if the symbol does not exist in the target environment.  This
689    function should not call error() if communication with the target
690    is interrupted, since it is called from symbol reading, but should
691    return nonzero, possibly doing a complain().  */
692 
693 #define target_lookup_symbol(name, addrp) \
694      (*current_target.to_lookup_symbol) (name, addrp)
695 
696 /* Start an inferior process and set inferior_ptid to its pid.
697    EXEC_FILE is the file to run.
698    ALLARGS is a string containing the arguments to the program.
699    ENV is the environment vector to pass.  Errors reported with error().
700    On VxWorks and various standalone systems, we ignore exec_file.  */
701 
702 #define	target_create_inferior(exec_file, args, env, FROM_TTY)	\
703      (*current_target.to_create_inferior) (exec_file, args, env, (FROM_TTY))
704 
705 
706 /* Some targets (such as ttrace-based HPUX) don't allow us to request
707    notification of inferior events such as fork and vork immediately
708    after the inferior is created.  (This because of how gdb gets an
709    inferior created via invoking a shell to do it.  In such a scenario,
710    if the shell init file has commands in it, the shell will fork and
711    exec for each of those commands, and we will see each such fork
712    event.  Very bad.)
713 
714    Such targets will supply an appropriate definition for this function.  */
715 
716 #define target_post_startup_inferior(ptid) \
717      (*current_target.to_post_startup_inferior) (ptid)
718 
719 /* On some targets, the sequence of starting up an inferior requires
720    some synchronization between gdb and the new inferior process, PID.  */
721 
722 #define target_acknowledge_created_inferior(pid) \
723      (*current_target.to_acknowledge_created_inferior) (pid)
724 
725 /* On some targets, we can catch an inferior fork or vfork event when
726    it occurs.  These functions insert/remove an already-created
727    catchpoint for such events.  */
728 
729 #define target_insert_fork_catchpoint(pid) \
730      (*current_target.to_insert_fork_catchpoint) (pid)
731 
732 #define target_remove_fork_catchpoint(pid) \
733      (*current_target.to_remove_fork_catchpoint) (pid)
734 
735 #define target_insert_vfork_catchpoint(pid) \
736      (*current_target.to_insert_vfork_catchpoint) (pid)
737 
738 #define target_remove_vfork_catchpoint(pid) \
739      (*current_target.to_remove_vfork_catchpoint) (pid)
740 
741 /* If the inferior forks or vforks, this function will be called at
742    the next resume in order to perform any bookkeeping and fiddling
743    necessary to continue debugging either the parent or child, as
744    requested, and releasing the other.  Information about the fork
745    or vfork event is available via get_last_target_status ().
746    This function returns 1 if the inferior should not be resumed
747    (i.e. there is another event pending).  */
748 
749 #define target_follow_fork(follow_child) \
750      (*current_target.to_follow_fork) (follow_child)
751 
752 /* On some targets, we can catch an inferior exec event when it
753    occurs.  These functions insert/remove an already-created
754    catchpoint for such events.  */
755 
756 #define target_insert_exec_catchpoint(pid) \
757      (*current_target.to_insert_exec_catchpoint) (pid)
758 
759 #define target_remove_exec_catchpoint(pid) \
760      (*current_target.to_remove_exec_catchpoint) (pid)
761 
762 /* Returns the number of exec events that are reported when a process
763    invokes a flavor of the exec() system call on this target, if exec
764    events are being reported.  */
765 
766 #define target_reported_exec_events_per_exec_call() \
767      (*current_target.to_reported_exec_events_per_exec_call) ()
768 
769 /* Returns TRUE if PID has exited.  And, also sets EXIT_STATUS to the
770    exit code of PID, if any.  */
771 
772 #define target_has_exited(pid,wait_status,exit_status) \
773      (*current_target.to_has_exited) (pid,wait_status,exit_status)
774 
775 /* The debugger has completed a blocking wait() call.  There is now
776    some process event that must be processed.  This function should
777    be defined by those targets that require the debugger to perform
778    cleanup or internal state changes in response to the process event.  */
779 
780 /* The inferior process has died.  Do what is right.  */
781 
782 #define	target_mourn_inferior()	\
783      (*current_target.to_mourn_inferior) ()
784 
785 /* Does target have enough data to do a run or attach command? */
786 
787 #define target_can_run(t) \
788      ((t)->to_can_run) ()
789 
790 /* post process changes to signal handling in the inferior.  */
791 
792 #define target_notice_signals(ptid) \
793      (*current_target.to_notice_signals) (ptid)
794 
795 /* Check to see if a thread is still alive.  */
796 
797 #define target_thread_alive(ptid) \
798      (*current_target.to_thread_alive) (ptid)
799 
800 /* Query for new threads and add them to the thread list.  */
801 
802 #define target_find_new_threads() \
803      (*current_target.to_find_new_threads) (); \
804 
805 /* Make target stop in a continuable fashion.  (For instance, under
806    Unix, this should act like SIGSTOP).  This function is normally
807    used by GUIs to implement a stop button.  */
808 
809 #define target_stop current_target.to_stop
810 
811 /* Send the specified COMMAND to the target's monitor
812    (shell,interpreter) for execution.  The result of the query is
813    placed in OUTBUF.  */
814 
815 #define target_rcmd(command, outbuf) \
816      (*current_target.to_rcmd) (command, outbuf)
817 
818 
819 /* Get the symbol information for a breakpointable routine called when
820    an exception event occurs.
821    Intended mainly for C++, and for those
822    platforms/implementations where such a callback mechanism is available,
823    e.g. HP-UX with ANSI C++ (aCC).  Some compilers (e.g. g++) support
824    different mechanisms for debugging exceptions.  */
825 
826 #define target_enable_exception_callback(kind, enable) \
827      (*current_target.to_enable_exception_callback) (kind, enable)
828 
829 /* Get the current exception event kind -- throw or catch, etc.  */
830 
831 #define target_get_current_exception_event() \
832      (*current_target.to_get_current_exception_event) ()
833 
834 /* Does the target include all of memory, or only part of it?  This
835    determines whether we look up the target chain for other parts of
836    memory if this target can't satisfy a request.  */
837 
838 #define	target_has_all_memory	\
839      (current_target.to_has_all_memory)
840 
841 /* Does the target include memory?  (Dummy targets don't.)  */
842 
843 #define	target_has_memory	\
844      (current_target.to_has_memory)
845 
846 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
847    we start a process.)  */
848 
849 #define	target_has_stack	\
850      (current_target.to_has_stack)
851 
852 /* Does the target have registers?  (Exec files don't.)  */
853 
854 #define	target_has_registers	\
855      (current_target.to_has_registers)
856 
857 /* Does the target have execution?  Can we make it jump (through
858    hoops), or pop its stack a few times?  FIXME: If this is to work that
859    way, it needs to check whether an inferior actually exists.
860    remote-udi.c and probably other targets can be the current target
861    when the inferior doesn't actually exist at the moment.  Right now
862    this just tells us whether this target is *capable* of execution.  */
863 
864 #define	target_has_execution	\
865      (current_target.to_has_execution)
866 
867 /* Can the target support the debugger control of thread execution?
868    a) Can it lock the thread scheduler?
869    b) Can it switch the currently running thread?  */
870 
871 #define target_can_lock_scheduler \
872      (current_target.to_has_thread_control & tc_schedlock)
873 
874 #define target_can_switch_threads \
875      (current_target.to_has_thread_control & tc_switch)
876 
877 /* Can the target support asynchronous execution? */
878 #define target_can_async_p() (current_target.to_can_async_p ())
879 
880 /* Is the target in asynchronous execution mode? */
881 #define target_is_async_p() (current_target.to_is_async_p())
882 
883 /* Put the target in async mode with the specified callback function. */
884 #define target_async(CALLBACK,CONTEXT) \
885      (current_target.to_async((CALLBACK), (CONTEXT)))
886 
887 /* This is to be used ONLY within call_function_by_hand(). It provides
888    a workaround, to have inferior function calls done in sychronous
889    mode, even though the target is asynchronous. After
890    target_async_mask(0) is called, calls to target_can_async_p() will
891    return FALSE , so that target_resume() will not try to start the
892    target asynchronously. After the inferior stops, we IMMEDIATELY
893    restore the previous nature of the target, by calling
894    target_async_mask(1). After that, target_can_async_p() will return
895    TRUE. ANY OTHER USE OF THIS FEATURE IS DEPRECATED.
896 
897    FIXME ezannoni 1999-12-13: we won't need this once we move
898    the turning async on and off to the single execution commands,
899    from where it is done currently, in remote_resume().  */
900 
901 #define	target_async_mask_value	\
902      (current_target.to_async_mask_value)
903 
904 extern int target_async_mask (int mask);
905 
906 extern void target_link (char *, CORE_ADDR *);
907 
908 /* Converts a process id to a string.  Usually, the string just contains
909    `process xyz', but on some systems it may contain
910    `process xyz thread abc'.  */
911 
912 #undef target_pid_to_str
913 #define target_pid_to_str(PID) current_target.to_pid_to_str (PID)
914 
915 #ifndef target_tid_to_str
916 #define target_tid_to_str(PID) \
917      target_pid_to_str (PID)
918 extern char *normal_pid_to_str (ptid_t ptid);
919 #endif
920 
921 /* Return a short string describing extra information about PID,
922    e.g. "sleeping", "runnable", "running on LWP 3".  Null return value
923    is okay.  */
924 
925 #define target_extra_thread_info(TP) \
926      (current_target.to_extra_thread_info (TP))
927 
928 /*
929  * New Objfile Event Hook:
930  *
931  * Sometimes a GDB component wants to get notified whenever a new
932  * objfile is loaded.  Mainly this is used by thread-debugging
933  * implementations that need to know when symbols for the target
934  * thread implemenation are available.
935  *
936  * The old way of doing this is to define a macro 'target_new_objfile'
937  * that points to the function that you want to be called on every
938  * objfile/shlib load.
939 
940    The new way is to grab the function pointer,
941    'deprecated_target_new_objfile_hook', and point it to the function
942    that you want to be called on every objfile/shlib load.
943 
944    If multiple clients are willing to be cooperative, they can each
945    save a pointer to the previous value of
946    deprecated_target_new_objfile_hook before modifying it, and arrange
947    for their function to call the previous function in the chain.  In
948    that way, multiple clients can receive this notification (something
949    like with signal handlers).  */
950 
951 extern void (*deprecated_target_new_objfile_hook) (struct objfile *);
952 
953 #ifndef target_pid_or_tid_to_str
954 #define target_pid_or_tid_to_str(ID) \
955      target_pid_to_str (ID)
956 #endif
957 
958 /* Attempts to find the pathname of the executable file
959    that was run to create a specified process.
960 
961    The process PID must be stopped when this operation is used.
962 
963    If the executable file cannot be determined, NULL is returned.
964 
965    Else, a pointer to a character string containing the pathname
966    is returned.  This string should be copied into a buffer by
967    the client if the string will not be immediately used, or if
968    it must persist.  */
969 
970 #define target_pid_to_exec_file(pid) \
971      (current_target.to_pid_to_exec_file) (pid)
972 
973 /*
974  * Iterator function for target memory regions.
975  * Calls a callback function once for each memory region 'mapped'
976  * in the child process.  Defined as a simple macro rather than
977  * as a function macro so that it can be tested for nullity.
978  */
979 
980 #define target_find_memory_regions(FUNC, DATA) \
981      (current_target.to_find_memory_regions) (FUNC, DATA)
982 
983 /*
984  * Compose corefile .note section.
985  */
986 
987 #define target_make_corefile_notes(BFD, SIZE_P) \
988      (current_target.to_make_corefile_notes) (BFD, SIZE_P)
989 
990 /* Thread-local values.  */
991 #define target_get_thread_local_address \
992     (current_target.to_get_thread_local_address)
993 #define target_get_thread_local_address_p() \
994     (target_get_thread_local_address != NULL)
995 
996 /* Hook to call target dependent code just after inferior target process has
997    started.  */
998 
999 #ifndef TARGET_CREATE_INFERIOR_HOOK
1000 #define TARGET_CREATE_INFERIOR_HOOK(PID)
1001 #endif
1002 
1003 /* Hardware watchpoint interfaces.  */
1004 
1005 /* Returns non-zero if we were stopped by a hardware watchpoint (memory read or
1006    write).  */
1007 
1008 #ifndef STOPPED_BY_WATCHPOINT
1009 #define STOPPED_BY_WATCHPOINT(w) \
1010    (*current_target.to_stopped_by_watchpoint) ()
1011 #endif
1012 
1013 /* Non-zero if we have continuable watchpoints  */
1014 
1015 #ifndef HAVE_CONTINUABLE_WATCHPOINT
1016 #define HAVE_CONTINUABLE_WATCHPOINT \
1017    (current_target.to_have_continuable_watchpoint)
1018 #endif
1019 
1020 /* HP-UX supplies these operations, which respectively disable and enable
1021    the memory page-protections that are used to implement hardware watchpoints
1022    on that platform.  See wait_for_inferior's use of these.  */
1023 
1024 #if !defined(TARGET_DISABLE_HW_WATCHPOINTS)
1025 #define TARGET_DISABLE_HW_WATCHPOINTS(pid)
1026 #endif
1027 
1028 #if !defined(TARGET_ENABLE_HW_WATCHPOINTS)
1029 #define TARGET_ENABLE_HW_WATCHPOINTS(pid)
1030 #endif
1031 
1032 /* Provide defaults for hardware watchpoint functions.  */
1033 
1034 /* If the *_hw_beakpoint functions have not been defined
1035    elsewhere use the definitions in the target vector.  */
1036 
1037 /* Returns non-zero if we can set a hardware watchpoint of type TYPE.  TYPE is
1038    one of bp_hardware_watchpoint, bp_read_watchpoint, bp_write_watchpoint, or
1039    bp_hardware_breakpoint.  CNT is the number of such watchpoints used so far
1040    (including this one?).  OTHERTYPE is who knows what...  */
1041 
1042 #ifndef TARGET_CAN_USE_HARDWARE_WATCHPOINT
1043 #define TARGET_CAN_USE_HARDWARE_WATCHPOINT(TYPE,CNT,OTHERTYPE) \
1044  (*current_target.to_can_use_hw_breakpoint) (TYPE, CNT, OTHERTYPE);
1045 #endif
1046 
1047 #if !defined(TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT)
1048 #define TARGET_REGION_SIZE_OK_FOR_HW_WATCHPOINT(byte_count) \
1049     (*current_target.to_region_size_ok_for_hw_watchpoint) (byte_count)
1050 #endif
1051 
1052 
1053 /* Set/clear a hardware watchpoint starting at ADDR, for LEN bytes.  TYPE is 0
1054    for write, 1 for read, and 2 for read/write accesses.  Returns 0 for
1055    success, non-zero for failure.  */
1056 
1057 #ifndef target_insert_watchpoint
1058 #define	target_insert_watchpoint(addr, len, type)	\
1059      (*current_target.to_insert_watchpoint) (addr, len, type)
1060 
1061 #define	target_remove_watchpoint(addr, len, type)	\
1062      (*current_target.to_remove_watchpoint) (addr, len, type)
1063 #endif
1064 
1065 #ifndef target_insert_hw_breakpoint
1066 #define target_insert_hw_breakpoint(addr, save) \
1067      (*current_target.to_insert_hw_breakpoint) (addr, save)
1068 
1069 #define target_remove_hw_breakpoint(addr, save) \
1070      (*current_target.to_remove_hw_breakpoint) (addr, save)
1071 #endif
1072 
1073 extern int target_stopped_data_address_p (struct target_ops *);
1074 
1075 #ifndef target_stopped_data_address
1076 #define target_stopped_data_address(target, x) \
1077     (*target.to_stopped_data_address) (target, x)
1078 #else
1079 /* Horrible hack to get around existing macros :-(.  */
1080 #define target_stopped_data_address_p(CURRENT_TARGET) (1)
1081 #endif
1082 
1083 /* This will only be defined by a target that supports catching vfork events,
1084    such as HP-UX.
1085 
1086    On some targets (such as HP-UX 10.20 and earlier), resuming a newly vforked
1087    child process after it has exec'd, causes the parent process to resume as
1088    well.  To prevent the parent from running spontaneously, such targets should
1089    define this to a function that prevents that from happening.  */
1090 #if !defined(ENSURE_VFORKING_PARENT_REMAINS_STOPPED)
1091 #define ENSURE_VFORKING_PARENT_REMAINS_STOPPED(PID) (0)
1092 #endif
1093 
1094 /* This will only be defined by a target that supports catching vfork events,
1095    such as HP-UX.
1096 
1097    On some targets (such as HP-UX 10.20 and earlier), a newly vforked child
1098    process must be resumed when it delivers its exec event, before the parent
1099    vfork event will be delivered to us.  */
1100 
1101 #if !defined(RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK)
1102 #define RESUME_EXECD_VFORKING_CHILD_TO_GET_PARENT_VFORK() (0)
1103 #endif
1104 
1105 /* Routines for maintenance of the target structures...
1106 
1107    add_target:   Add a target to the list of all possible targets.
1108 
1109    push_target:  Make this target the top of the stack of currently used
1110    targets, within its particular stratum of the stack.  Result
1111    is 0 if now atop the stack, nonzero if not on top (maybe
1112    should warn user).
1113 
1114    unpush_target: Remove this from the stack of currently used targets,
1115    no matter where it is on the list.  Returns 0 if no
1116    change, 1 if removed from stack.
1117 
1118    pop_target:   Remove the top thing on the stack of current targets.  */
1119 
1120 extern void add_target (struct target_ops *);
1121 
1122 extern int push_target (struct target_ops *);
1123 
1124 extern int unpush_target (struct target_ops *);
1125 
1126 extern void target_preopen (int);
1127 
1128 extern void pop_target (void);
1129 
1130 /* Struct section_table maps address ranges to file sections.  It is
1131    mostly used with BFD files, but can be used without (e.g. for handling
1132    raw disks, or files not in formats handled by BFD).  */
1133 
1134 struct section_table
1135   {
1136     CORE_ADDR addr;		/* Lowest address in section */
1137     CORE_ADDR endaddr;		/* 1+highest address in section */
1138 
1139     struct bfd_section *the_bfd_section;
1140 
1141     bfd *bfd;			/* BFD file pointer */
1142   };
1143 
1144 /* Return the "section" containing the specified address.  */
1145 struct section_table *target_section_by_addr (struct target_ops *target,
1146 					      CORE_ADDR addr);
1147 
1148 
1149 /* From mem-break.c */
1150 
1151 extern int memory_remove_breakpoint (CORE_ADDR, char *);
1152 
1153 extern int memory_insert_breakpoint (CORE_ADDR, char *);
1154 
1155 extern int default_memory_remove_breakpoint (CORE_ADDR, char *);
1156 
1157 extern int default_memory_insert_breakpoint (CORE_ADDR, char *);
1158 
1159 
1160 /* From target.c */
1161 
1162 extern void initialize_targets (void);
1163 
1164 extern void noprocess (void);
1165 
1166 extern void find_default_attach (char *, int);
1167 
1168 extern void find_default_create_inferior (char *, char *, char **, int);
1169 
1170 extern struct target_ops *find_run_target (void);
1171 
1172 extern struct target_ops *find_core_target (void);
1173 
1174 extern struct target_ops *find_target_beneath (struct target_ops *);
1175 
1176 extern int target_resize_to_sections (struct target_ops *target,
1177 				      int num_added);
1178 
1179 extern void remove_target_sections (bfd *abfd);
1180 
1181 
1182 /* Stuff that should be shared among the various remote targets.  */
1183 
1184 /* Debugging level.  0 is off, and non-zero values mean to print some debug
1185    information (higher values, more information).  */
1186 extern int remote_debug;
1187 
1188 /* Speed in bits per second, or -1 which means don't mess with the speed.  */
1189 extern int baud_rate;
1190 /* Timeout limit for response from target. */
1191 extern int remote_timeout;
1192 
1193 
1194 /* Functions for helping to write a native target.  */
1195 
1196 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
1197 extern void store_waitstatus (struct target_waitstatus *, int);
1198 
1199 /* Predicate to target_signal_to_host(). Return non-zero if the enum
1200    targ_signal SIGNO has an equivalent ``host'' representation.  */
1201 /* FIXME: cagney/1999-11-22: The name below was chosen in preference
1202    to the shorter target_signal_p() because it is far less ambigious.
1203    In this context ``target_signal'' refers to GDB's internal
1204    representation of the target's set of signals while ``host signal''
1205    refers to the target operating system's signal.  Confused?  */
1206 
1207 extern int target_signal_to_host_p (enum target_signal signo);
1208 
1209 /* Convert between host signal numbers and enum target_signal's.
1210    target_signal_to_host() returns 0 and prints a warning() on GDB's
1211    console if SIGNO has no equivalent host representation.  */
1212 /* FIXME: cagney/1999-11-22: Here ``host'' is used incorrectly, it is
1213    refering to the target operating system's signal numbering.
1214    Similarly, ``enum target_signal'' is named incorrectly, ``enum
1215    gdb_signal'' would probably be better as it is refering to GDB's
1216    internal representation of a target operating system's signal.  */
1217 
1218 extern enum target_signal target_signal_from_host (int);
1219 extern int target_signal_to_host (enum target_signal);
1220 
1221 /* Convert from a number used in a GDB command to an enum target_signal.  */
1222 extern enum target_signal target_signal_from_command (int);
1223 
1224 /* Any target can call this to switch to remote protocol (in remote.c). */
1225 extern void push_remote_target (char *name, int from_tty);
1226 
1227 /* Imported from machine dependent code */
1228 
1229 /* Blank target vector entries are initialized to target_ignore. */
1230 void target_ignore (void);
1231 
1232 extern struct target_ops deprecated_child_ops;
1233 
1234 #endif /* !defined (TARGET_H) */
1235