gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2    Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.  Written by John Gilmore.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #if !defined (TARGET_H)
  22 #define TARGET_H
  23
  24 /* This include file defines the interface between the main part
  25    of the debugger, and the part which is target-specific, or
  26    specific to the communications interface between us and the
  27    target.
  28
  29    A TARGET is an interface between the debugger and a particular
  30    kind of file or process.  Targets can be STACKED in STRATA,
  31    so that more than one target can potentially respond to a request.
  32    In particular, memory accesses will walk down the stack of targets
  33    until they find a target that is interested in handling that particular
  34    address.  STRATA are artificial boundaries on the stack, within
  35    which particular kinds of targets live.  Strata exist so that
  36    people don't get confused by pushing e.g. a process target and then
  37    a file target, and wondering why they can't see the current values
  38    of variables any more (the file target is handling them and they
  39    never get to the process target).  So when you push a file target,
  40    it goes into the file stratum, which is always below the process
  41    stratum.  */
  42
  43 #include "bfd.h"
  44
  45 enum strata {
  46         dummy_stratum,          /* The lowest of the low */
  47         file_stratum,           /* Executable files, etc */
  48         core_stratum,           /* Core dump files */
  49         process_stratum         /* Executing processes */
  50 };
  51
  52 /* Stuff for target_wait.  */
  53
  54 /* Generally, what has the program done?  */
  55 enum target_waitkind {
  56   /* The program has exited.  The exit status is in value.integer.  */
  57   TARGET_WAITKIND_EXITED,
  58
  59   /* The program has stopped with a signal.  Which signal is in value.sig.  */
  60   TARGET_WAITKIND_STOPPED,
  61
  62   /* The program has terminated with a signal.  Which signal is in
  63      value.sig.  */
  64   TARGET_WAITKIND_SIGNALLED
  65   };
  66
  67 /* The numbering of these signals is chosen to match traditional unix
  68    signals (insofar as various unices use the same numbers, anyway).
  69    It is also the numbering of the GDB remote protocol.  Other remote
  70    protocols, if they use a different numbering, should make sure to
  71    translate appropriately.  */
  72
  73 /* This is based strongly on Unix/POSIX signals for several reasons:
  74    (1) This set of signals represents a widely-accepted attempt to
  75    represent events of this sort in a portable fashion, (2) we want a
  76    signal to make it from wait to child_wait to the user intact, (3) many
  77    remote protocols use a similar encoding.  However, it is
  78    recognized that this set of signals has limitations (such as not
  79    distinguishing between various kinds of SIGSEGV, or not
  80    distinguishing hitting a breakpoint from finishing a single step).
  81    So in the future we may get around this either by adding additional
  82    signals for breakpoint, single-step, etc., or by adding signal
  83    codes; the latter seems more in the spirit of what BSD, System V,
  84    etc. are doing to address these issues.  */
  85
  86 /* For an explanation of what each signal means, see
  87    target_signal_to_string.  */
  88
  89 enum target_signal {
  90   /* Used some places (e.g. stop_signal) to record the concept that
  91      there is no signal.  */
  92   TARGET_SIGNAL_0 = 0,
  93   TARGET_SIGNAL_HUP = 1,
  94   TARGET_SIGNAL_INT = 2,
  95   TARGET_SIGNAL_QUIT = 3,
  96   TARGET_SIGNAL_ILL = 4,
  97   TARGET_SIGNAL_TRAP = 5,
  98   TARGET_SIGNAL_ABRT = 6,
  99   TARGET_SIGNAL_EMT = 7,
 100   TARGET_SIGNAL_FPE = 8,
 101   TARGET_SIGNAL_KILL = 9,
 102   TARGET_SIGNAL_BUS = 10,
 103   TARGET_SIGNAL_SEGV = 11,
 104   TARGET_SIGNAL_SYS = 12,
 105   TARGET_SIGNAL_PIPE = 13,
 106   TARGET_SIGNAL_ALRM = 14,
 107   TARGET_SIGNAL_TERM = 15,
 108   TARGET_SIGNAL_URG = 16,
 109   TARGET_SIGNAL_STOP = 17,
 110   TARGET_SIGNAL_TSTP = 18,
 111   TARGET_SIGNAL_CONT = 19,
 112   TARGET_SIGNAL_CHLD = 20,
 113   TARGET_SIGNAL_TTIN = 21,
 114   TARGET_SIGNAL_TTOU = 22,
 115   TARGET_SIGNAL_IO = 23,
 116   TARGET_SIGNAL_XCPU = 24,
 117   TARGET_SIGNAL_XFSZ = 25,
 118   TARGET_SIGNAL_VTALRM = 26,
 119   TARGET_SIGNAL_PROF = 27,
 120   TARGET_SIGNAL_WINCH = 28,
 121   TARGET_SIGNAL_LOST = 29,
 122   TARGET_SIGNAL_USR1 = 30,
 123   TARGET_SIGNAL_USR2 = 31,
 124   TARGET_SIGNAL_PWR = 32,
 125   /* Similar to SIGIO.  Perhaps they should have the same number.  */
 126   TARGET_SIGNAL_POLL = 33,
 127   TARGET_SIGNAL_WIND = 34,
 128   TARGET_SIGNAL_PHONE = 35,
 129   TARGET_SIGNAL_WAITING = 36,
 130   TARGET_SIGNAL_LWP = 37,
 131   TARGET_SIGNAL_DANGER = 38,
 132   TARGET_SIGNAL_GRANT = 39,
 133   TARGET_SIGNAL_RETRACT = 40,
 134   TARGET_SIGNAL_MSG = 41,
 135   TARGET_SIGNAL_SOUND = 42,
 136   TARGET_SIGNAL_SAK = 43,
 137
 138   /* Some signal we don't know about.  */
 139   TARGET_SIGNAL_UNKNOWN,
 140
 141   /* Last and unused enum value, for sizing arrays, etc.  */
 142   TARGET_SIGNAL_LAST
 143 };
 144
 145 struct target_waitstatus {
 146   enum target_waitkind kind;
 147
 148   /* Exit status or signal number.  */
 149   union {
 150     int integer;
 151     enum target_signal sig;
 152   } value;
 153 };
 154
 155 /* Return the string for a signal.  */
 156 extern char *target_signal_to_string PARAMS ((enum target_signal));
 157
 158 /* Return the name (SIGHUP, etc.) for a signal.  */
 159 extern char *target_signal_to_name PARAMS ((enum target_signal));
 160
 161 /* Given a name (SIGHUP, etc.), return its signal.  */
 162 enum target_signal target_signal_from_name PARAMS ((char *));
 163 \f
 164 struct target_ops
 165 {
 166   char         *to_shortname;   /* Name this target type */
 167   char         *to_longname;    /* Name for printing */
 168   char         *to_doc;         /* Documentation.  Does not include trailing
 169                                    newline, and starts with a one-line descrip-
 170                                    tion (probably similar to to_longname). */
 171   void        (*to_open) PARAMS ((char *, int));
 172   void        (*to_close) PARAMS ((int));
 173   void        (*to_attach) PARAMS ((char *, int));
 174   void        (*to_detach) PARAMS ((char *, int));
 175   void        (*to_resume) PARAMS ((int, int, enum target_signal));
 176   int         (*to_wait) PARAMS ((int, struct target_waitstatus *));
 177   void        (*to_fetch_registers) PARAMS ((int));
 178   void        (*to_store_registers) PARAMS ((int));
 179   void        (*to_prepare_to_store) PARAMS ((void));
 180
 181   /* Transfer LEN bytes of memory between GDB address MYADDR and
 182      target address MEMADDR.  If WRITE, transfer them to the target, else
 183      transfer them from the target.  TARGET is the target from which we
 184      get this function.
 185
 186      Return value, N, is one of the following:
 187
 188      0 means that we can't handle this.  If errno has been set, it is the
 189      error which prevented us from doing it (FIXME: What about bfd_error?).
 190
 191      positive (call it N) means that we have transferred N bytes
 192      starting at MEMADDR.  We might be able to handle more bytes
 193      beyond this length, but no promises.
 194
 195      negative (call its absolute value N) means that we cannot
 196      transfer right at MEMADDR, but we could transfer at least
 197      something at MEMADDR + N.  */
 198
 199   int         (*to_xfer_memory) PARAMS ((CORE_ADDR memaddr, char *myaddr,
 200                                          int len, int write,
 201                                          struct target_ops * target));
 202
 203   void        (*to_files_info) PARAMS ((struct target_ops *));
 204   int         (*to_insert_breakpoint) PARAMS ((CORE_ADDR, char *));
 205   int         (*to_remove_breakpoint) PARAMS ((CORE_ADDR, char *));
 206   void        (*to_terminal_init) PARAMS ((void));
 207   void        (*to_terminal_inferior) PARAMS ((void));
 208   void        (*to_terminal_ours_for_output) PARAMS ((void));
 209   void        (*to_terminal_ours) PARAMS ((void));
 210   void        (*to_terminal_info) PARAMS ((char *, int));
 211   void        (*to_kill) PARAMS ((void));
 212   void        (*to_load) PARAMS ((char *, int));
 213   int         (*to_lookup_symbol) PARAMS ((char *, CORE_ADDR *));
 214   void        (*to_create_inferior) PARAMS ((char *, char *, char **));
 215   void        (*to_mourn_inferior) PARAMS ((void));
 216   int         (*to_can_run) PARAMS ((void));
 217   void        (*to_notice_signals) PARAMS ((int pid));
 218   enum strata   to_stratum;
 219   struct target_ops
 220                *to_next;
 221   int           to_has_all_memory;
 222   int           to_has_memory;
 223   int           to_has_stack;
 224   int           to_has_registers;
 225   int           to_has_execution;
 226   struct section_table
 227                *to_sections;
 228   struct section_table
 229                *to_sections_end;
 230   int           to_magic;
 231   /* Need sub-structure for target machine related rather than comm related? */
 232 };
 233
 234 /* Magic number for checking ops size.  If a struct doesn't end with this
 235    number, somebody changed the declaration but didn't change all the
 236    places that initialize one.  */
 237
 238 #define OPS_MAGIC       3840
 239
 240 /* The ops structure for our "current" target process.  This should
 241    never be NULL.  If there is no target, it points to the dummy_target.  */
 242
 243 extern struct target_ops        *current_target;
 244
 245 /* Define easy words for doing these operations on our current target.  */
 246
 247 #define target_shortname        (current_target->to_shortname)
 248 #define target_longname         (current_target->to_longname)
 249
 250 /* The open routine takes the rest of the parameters from the command,
 251    and (if successful) pushes a new target onto the stack.
 252    Targets should supply this routine, if only to provide an error message.  */
 253 #define target_open(name, from_tty)     \
 254         (*current_target->to_open) (name, from_tty)
 255
 256 /* Does whatever cleanup is required for a target that we are no longer
 257    going to be calling.  Argument says whether we are quitting gdb and
 258    should not get hung in case of errors, or whether we want a clean
 259    termination even if it takes a while.  This routine is automatically
 260    always called just before a routine is popped off the target stack.
 261    Closing file descriptors and freeing memory are typical things it should
 262    do.  */
 263
 264 #define target_close(quitting)  \
 265         (*current_target->to_close) (quitting)
 266
 267 /* Attaches to a process on the target side.  Arguments are as passed
 268    to the `attach' command by the user.  This routine can be called
 269    when the target is not on the target-stack, if the target_can_run
 270    routine returns 1; in that case, it must push itself onto the stack.
 271    Upon exit, the target should be ready for normal operations, and
 272    should be ready to deliver the status of the process immediately
 273    (without waiting) to an upcoming target_wait call.  */
 274
 275 #define target_attach(args, from_tty)   \
 276         (*current_target->to_attach) (args, from_tty)
 277
 278 /* Takes a program previously attached to and detaches it.
 279    The program may resume execution (some targets do, some don't) and will
 280    no longer stop on signals, etc.  We better not have left any breakpoints
 281    in the program or it'll die when it hits one.  ARGS is arguments
 282    typed by the user (e.g. a signal to send the process).  FROM_TTY
 283    says whether to be verbose or not.  */
 284
 285 extern void
 286 target_detach PARAMS ((char *, int));
 287
 288 /* Resume execution of the target process PID.  STEP says whether to
 289    single-step or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be
 290    given to the target, or zero for no signal.  */
 291
 292 #define target_resume(pid, step, siggnal)       \
 293         (*current_target->to_resume) (pid, step, siggnal)
 294
 295 /* Wait for process pid to do something.  Pid = -1 to wait for any pid to do
 296    something.  Return pid of child, or -1 in case of error; store status
 297    through argument pointer STATUS.  */
 298
 299 #define target_wait(pid, status)                \
 300         (*current_target->to_wait) (pid, status)
 301
 302 /* Fetch register REGNO, or all regs if regno == -1.  No result.  */
 303
 304 #define target_fetch_registers(regno)   \
 305         (*current_target->to_fetch_registers) (regno)
 306
 307 /* Store at least register REGNO, or all regs if REGNO == -1.
 308    It can store as many registers as it wants to, so target_prepare_to_store
 309    must have been previously called.  Calls error() if there are problems.  */
 310
 311 #define target_store_registers(regs)    \
 312         (*current_target->to_store_registers) (regs)
 313
 314 /* Get ready to modify the registers array.  On machines which store
 315    individual registers, this doesn't need to do anything.  On machines
 316    which store all the registers in one fell swoop, this makes sure
 317    that REGISTERS contains all the registers from the program being
 318    debugged.  */
 319
 320 #define target_prepare_to_store()       \
 321         (*current_target->to_prepare_to_store) ()
 322
 323 extern int
 324 target_read_string PARAMS ((CORE_ADDR, char *, int));
 325
 326 extern int
 327 target_read_memory PARAMS ((CORE_ADDR, char *, int));
 328
 329 extern int
 330 target_read_memory_partial PARAMS ((CORE_ADDR, char *, int, int *));
 331
 332 extern int
 333 target_write_memory PARAMS ((CORE_ADDR, char *, int));
 334
 335 extern int
 336 xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 337
 338 extern int
 339 child_xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 340
 341 /* Transfer LEN bytes between target address MEMADDR and GDB address MYADDR.
 342    Returns 0 for success, errno code for failure (which includes partial
 343    transfers--if you want a more useful response to partial transfers, try
 344    target_read_memory_partial).  */
 345
 346 extern int target_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr,
 347                                        int len, int write));
 348
 349 /* From exec.c */
 350
 351 extern void
 352 print_section_info PARAMS ((struct target_ops *, bfd *));
 353
 354 /* Print a line about the current target.  */
 355
 356 #define target_files_info()     \
 357         (*current_target->to_files_info) (current_target)
 358
 359 /* Insert a breakpoint at address ADDR in the target machine.
 360    SAVE is a pointer to memory allocated for saving the
 361    target contents.  It is guaranteed by the caller to be long enough
 362    to save "sizeof BREAKPOINT" bytes.  Result is 0 for success, or
 363    an errno value.  */
 364
 365 #define target_insert_breakpoint(addr, save)    \
 366         (*current_target->to_insert_breakpoint) (addr, save)
 367
 368 /* Remove a breakpoint at address ADDR in the target machine.
 369    SAVE is a pointer to the same save area
 370    that was previously passed to target_insert_breakpoint.
 371    Result is 0 for success, or an errno value.  */
 372
 373 #define target_remove_breakpoint(addr, save)    \
 374         (*current_target->to_remove_breakpoint) (addr, save)
 375
 376 /* Initialize the terminal settings we record for the inferior,
 377    before we actually run the inferior.  */
 378
 379 #define target_terminal_init() \
 380         (*current_target->to_terminal_init) ()
 381
 382 /* Put the inferior's terminal settings into effect.
 383    This is preparation for starting or resuming the inferior.  */
 384
 385 #define target_terminal_inferior() \
 386         (*current_target->to_terminal_inferior) ()
 387
 388 /* Put some of our terminal settings into effect,
 389    enough to get proper results from our output,
 390    but do not change into or out of RAW mode
 391    so that no input is discarded.
 392
 393    After doing this, either terminal_ours or terminal_inferior
 394    should be called to get back to a normal state of affairs.  */
 395
 396 #define target_terminal_ours_for_output() \
 397         (*current_target->to_terminal_ours_for_output) ()
 398
 399 /* Put our terminal settings into effect.
 400    First record the inferior's terminal settings
 401    so they can be restored properly later.  */
 402
 403 #define target_terminal_ours() \
 404         (*current_target->to_terminal_ours) ()
 405
 406 /* Print useful information about our terminal status, if such a thing
 407    exists.  */
 408
 409 #define target_terminal_info(arg, from_tty) \
 410         (*current_target->to_terminal_info) (arg, from_tty)
 411
 412 /* Kill the inferior process.   Make it go away.  */
 413
 414 #define target_kill() \
 415         (*current_target->to_kill) ()
 416
 417 /* Load an executable file into the target process.  This is expected to
 418    not only bring new code into the target process, but also to update
 419    GDB's symbol tables to match.  */
 420
 421 #define target_load(arg, from_tty) \
 422         (*current_target->to_load) (arg, from_tty)
 423
 424 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 425    name.  ADDRP is a CORE_ADDR * pointing to where the value of the symbol
 426    should be returned.  The result is 0 if successful, nonzero if the
 427    symbol does not exist in the target environment.  This function should
 428    not call error() if communication with the target is interrupted, since
 429    it is called from symbol reading, but should return nonzero, possibly
 430    doing a complain().  */
 431
 432 #define target_lookup_symbol(name, addrp)       \
 433   (*current_target->to_lookup_symbol) (name, addrp)
 434
 435 /* Start an inferior process and set inferior_pid to its pid.
 436    EXEC_FILE is the file to run.
 437    ALLARGS is a string containing the arguments to the program.
 438    ENV is the environment vector to pass.  Errors reported with error().
 439    On VxWorks and various standalone systems, we ignore exec_file.  */
 440
 441 #define target_create_inferior(exec_file, args, env)    \
 442         (*current_target->to_create_inferior) (exec_file, args, env)
 443
 444 /* The inferior process has died.  Do what is right.  */
 445
 446 #define target_mourn_inferior() \
 447         (*current_target->to_mourn_inferior) ()
 448
 449 /* Does target have enough data to do a run or attach command? */
 450
 451 #define target_can_run(t) \
 452         ((t)->to_can_run) ()
 453
 454 /* post process changes to signal handling in the inferior.  */
 455
 456 #define target_notice_signals(pid) \
 457         (*current_target->to_notice_signals) (pid)
 458
 459 /* Pointer to next target in the chain, e.g. a core file and an exec file.  */
 460
 461 #define target_next \
 462         (current_target->to_next)
 463
 464 /* Does the target include all of memory, or only part of it?  This
 465    determines whether we look up the target chain for other parts of
 466    memory if this target can't satisfy a request.  */
 467
 468 #define target_has_all_memory   \
 469         (current_target->to_has_all_memory)
 470
 471 /* Does the target include memory?  (Dummy targets don't.)  */
 472
 473 #define target_has_memory       \
 474         (current_target->to_has_memory)
 475
 476 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 477    we start a process.)  */
 478
 479 #define target_has_stack        \
 480         (current_target->to_has_stack)
 481
 482 /* Does the target have registers?  (Exec files don't.)  */
 483
 484 #define target_has_registers    \
 485         (current_target->to_has_registers)
 486
 487 /* Does the target have execution?  Can we make it jump (through
 488    hoops), or pop its stack a few times?  FIXME: If this is to work that
 489    way, it needs to check whether an inferior actually exists.
 490    remote-udi.c and probably other targets can be the current target
 491    when the inferior doesn't actually exist at the moment.  Right now
 492    this just tells us whether this target is *capable* of execution.  */
 493
 494 #define target_has_execution    \
 495         (current_target->to_has_execution)
 496
 497 /* Converts a process id to a string.  Usually, the string just contains
 498    `process xyz', but on some systems it may contain
 499    `process xyz thread abc'.  */
 500
 501 #ifndef target_pid_to_str
 502 #define target_pid_to_str(PID) \
 503         normal_pid_to_str (PID)
 504 extern char *normal_pid_to_str PARAMS ((int pid));
 505 #endif
 506
 507 /* Routines for maintenance of the target structures...
 508
 509    add_target:   Add a target to the list of all possible targets.
 510
 511    push_target:  Make this target the top of the stack of currently used
 512                  targets, within its particular stratum of the stack.  Result
 513                  is 0 if now atop the stack, nonzero if not on top (maybe
 514                  should warn user).
 515
 516    unpush_target: Remove this from the stack of currently used targets,
 517                  no matter where it is on the list.  Returns 0 if no
 518                  change, 1 if removed from stack.
 519
 520    pop_target:   Remove the top thing on the stack of current targets.  */
 521
 522 extern void
 523 add_target PARAMS ((struct target_ops *));
 524
 525 extern int
 526 push_target PARAMS ((struct target_ops *));
 527
 528 extern int
 529 unpush_target PARAMS ((struct target_ops *));
 530
 531 extern void
 532 target_preopen PARAMS ((int));
 533
 534 extern void
 535 pop_target PARAMS ((void));
 536
 537 /* Struct section_table maps address ranges to file sections.  It is
 538    mostly used with BFD files, but can be used without (e.g. for handling
 539    raw disks, or files not in formats handled by BFD).  */
 540
 541 struct section_table {
 542   CORE_ADDR addr;               /* Lowest address in section */
 543   CORE_ADDR endaddr;            /* 1+highest address in section */
 544   sec_ptr   sec_ptr;            /* BFD section pointer */
 545   bfd      *bfd;                /* BFD file pointer */
 546 };
 547
 548 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
 549    Returns 0 if OK, 1 on error.  */
 550
 551 extern int
 552 build_section_table PARAMS ((bfd *, struct section_table **,
 553                              struct section_table **));
 554
 555 /* From mem-break.c */
 556
 557 extern int
 558 memory_remove_breakpoint PARAMS ((CORE_ADDR, char *));
 559
 560 extern int
 561 memory_insert_breakpoint PARAMS ((CORE_ADDR, char *));
 562
 563 /* From target.c */
 564
 565 void
 566 noprocess PARAMS ((void));
 567
 568 void
 569 find_default_attach PARAMS ((char *, int));
 570
 571 void
 572 find_default_create_inferior PARAMS ((char *, char *, char **));
 573
 574 struct target_ops *
 575 find_core_target PARAMS ((void));
 576 \f
 577 /* Stuff that should be shared among the various remote targets.  */
 578
 579 /* Debugging level.  0 is off, and non-zero values mean to print some debug
 580    information (higher values, more information).  */
 581 extern int remote_debug;
 582
 583 /* Speed in bits per second.  */
 584 extern int baud_rate;
 585 \f
 586 /* Functions for helping to write a native target.  */
 587
 588 /* This is for native targets which use a unix/POSIX-style waitstatus.  */
 589 extern void store_waitstatus PARAMS ((struct target_waitstatus *, int));
 590
 591 /* Convert between host signal numbers and enum target_signal's.  */
 592 extern enum target_signal target_signal_from_host PARAMS ((int));
 593 extern int target_signal_to_host PARAMS ((enum target_signal));
 594
 595 #endif  /* !defined (TARGET_H) */