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 struct target_ops
  53 {
  54   char         *to_shortname;   /* Name this target type */
  55   char         *to_longname;    /* Name for printing */
  56   char         *to_doc;         /* Documentation.  Does not include trailing
  57                                    newline, and starts with a one-line descrip-
  58                                    tion (probably similar to to_longname). */
  59   void        (*to_open) PARAMS ((char *, int));
  60   void        (*to_close) PARAMS ((int));
  61   void        (*to_attach) PARAMS ((char *, int));
  62   void        (*to_detach) PARAMS ((char *, int));
  63   void        (*to_resume) PARAMS ((int, int, int));
  64   int         (*to_wait) PARAMS ((int *));
  65   void        (*to_fetch_registers) PARAMS ((int));
  66   void        (*to_store_registers) PARAMS ((int));
  67   void        (*to_prepare_to_store) PARAMS ((void));
  68
  69   /* Transfer LEN bytes of memory between GDB address MYADDR and
  70      target address MEMADDR.  If WRITE, transfer them to the target, else
  71      transfer them from the target.  TARGET is the target from which we
  72      get this function.
  73
  74      Return value, N, is one of the following:
  75
  76      0 means that we can't handle this.  If errno has been set, it is the
  77      error which prevented us from doing it (FIXME: What about bfd_error?).
  78
  79      positive (call it N) means that we have transferred N bytes
  80      starting at MEMADDR.  We might be able to handle more bytes
  81      beyond this length, but no promises.
  82
  83      negative (call its absolute value N) means that we cannot
  84      transfer right at MEMADDR, but we could transfer at least
  85      something at MEMADDR + N.  */
  86
  87   int         (*to_xfer_memory) PARAMS ((CORE_ADDR memaddr, char *myaddr,
  88                                          int len, int write,
  89                                          struct target_ops * target));
  90
  91   void        (*to_files_info) PARAMS ((struct target_ops *));
  92   int         (*to_insert_breakpoint) PARAMS ((CORE_ADDR, char *));
  93   int         (*to_remove_breakpoint) PARAMS ((CORE_ADDR, char *));
  94   void        (*to_terminal_init) PARAMS ((void));
  95   void        (*to_terminal_inferior) PARAMS ((void));
  96   void        (*to_terminal_ours_for_output) PARAMS ((void));
  97   void        (*to_terminal_ours) PARAMS ((void));
  98   void        (*to_terminal_info) PARAMS ((char *, int));
  99   void        (*to_kill) PARAMS ((void));
 100   void        (*to_load) PARAMS ((char *, int));
 101   int         (*to_lookup_symbol) PARAMS ((char *, CORE_ADDR *));
 102   void        (*to_create_inferior) PARAMS ((char *, char *, char **));
 103   void        (*to_mourn_inferior) PARAMS ((void));
 104   int         (*to_can_run) PARAMS ((void));
 105   void        (*to_notice_signals) PARAMS ((void));
 106   enum strata   to_stratum;
 107   struct target_ops
 108                *to_next;
 109   int           to_has_all_memory;
 110   int           to_has_memory;
 111   int           to_has_stack;
 112   int           to_has_registers;
 113   int           to_has_execution;
 114   struct section_table
 115                *to_sections;
 116   struct section_table
 117                *to_sections_end;
 118   int           to_magic;
 119   /* Need sub-structure for target machine related rather than comm related? */
 120 };
 121
 122 /* Magic number for checking ops size.  If a struct doesn't end with this
 123    number, somebody changed the declaration but didn't change all the
 124    places that initialize one.  */
 125
 126 #define OPS_MAGIC       3840
 127
 128 /* The ops structure for our "current" target process.  This should
 129    never be NULL.  If there is no target, it points to the dummy_target.  */
 130
 131 extern struct target_ops        *current_target;
 132
 133 /* Define easy words for doing these operations on our current target.  */
 134
 135 #define target_shortname        (current_target->to_shortname)
 136 #define target_longname         (current_target->to_longname)
 137
 138 /* The open routine takes the rest of the parameters from the command,
 139    and (if successful) pushes a new target onto the stack.
 140    Targets should supply this routine, if only to provide an error message.  */
 141 #define target_open(name, from_tty)     \
 142         (*current_target->to_open) (name, from_tty)
 143
 144 /* Does whatever cleanup is required for a target that we are no longer
 145    going to be calling.  Argument says whether we are quitting gdb and
 146    should not get hung in case of errors, or whether we want a clean
 147    termination even if it takes a while.  This routine is automatically
 148    always called just before a routine is popped off the target stack.
 149    Closing file descriptors and freeing memory are typical things it should
 150    do.  */
 151
 152 #define target_close(quitting)  \
 153         (*current_target->to_close) (quitting)
 154
 155 /* Attaches to a process on the target side.  Arguments are as passed
 156    to the `attach' command by the user.  This routine can be called
 157    when the target is not on the target-stack, if the target_can_run
 158    routine returns 1; in that case, it must push itself onto the stack.
 159    Upon exit, the target should be ready for normal operations, and
 160    should be ready to deliver the status of the process immediately
 161    (without waiting) to an upcoming target_wait call.  */
 162
 163 #define target_attach(args, from_tty)   \
 164         (*current_target->to_attach) (args, from_tty)
 165
 166 /* Takes a program previously attached to and detaches it.
 167    The program may resume execution (some targets do, some don't) and will
 168    no longer stop on signals, etc.  We better not have left any breakpoints
 169    in the program or it'll die when it hits one.  ARGS is arguments
 170    typed by the user (e.g. a signal to send the process).  FROM_TTY
 171    says whether to be verbose or not.  */
 172
 173 extern void
 174 target_detach PARAMS ((char *, int));
 175
 176 /* Resume execution of the target process PID.  STEP says whether to
 177    single-step or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be
 178    given to the target, or zero for no signal.  */
 179
 180 #define target_resume(pid, step, siggnal)       \
 181         (*current_target->to_resume) (pid, step, siggnal)
 182
 183 /* Wait for inferior process to do something.  Return pid of child,
 184    or -1 in case of error; store status through argument pointer STATUS.  */
 185
 186 #define target_wait(status)             \
 187         (*current_target->to_wait) (status)
 188
 189 /* Fetch register REGNO, or all regs if regno == -1.  No result.  */
 190
 191 #define target_fetch_registers(regno)   \
 192         (*current_target->to_fetch_registers) (regno)
 193
 194 /* Store at least register REGNO, or all regs if REGNO == -1.
 195    It can store as many registers as it wants to, so target_prepare_to_store
 196    must have been previously called.  Calls error() if there are problems.  */
 197
 198 #define target_store_registers(regs)    \
 199         (*current_target->to_store_registers) (regs)
 200
 201 /* Get ready to modify the registers array.  On machines which store
 202    individual registers, this doesn't need to do anything.  On machines
 203    which store all the registers in one fell swoop, this makes sure
 204    that REGISTERS contains all the registers from the program being
 205    debugged.  */
 206
 207 #define target_prepare_to_store()       \
 208         (*current_target->to_prepare_to_store) ()
 209
 210 extern int
 211 target_read_string PARAMS ((CORE_ADDR, char *, int));
 212
 213 extern int
 214 target_read_memory PARAMS ((CORE_ADDR, char *, int));
 215
 216 extern int
 217 target_read_memory_partial PARAMS ((CORE_ADDR, char *, int, int *));
 218
 219 extern int
 220 target_write_memory PARAMS ((CORE_ADDR, char *, int));
 221
 222 extern int
 223 xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 224
 225 extern int
 226 child_xfer_memory PARAMS ((CORE_ADDR, char *, int, int, struct target_ops *));
 227
 228 /* Transfer LEN bytes between target address MEMADDR and GDB address MYADDR.
 229    Returns 0 for success, errno code for failure (which includes partial
 230    transfers--if you want a more useful response to partial transfers, try
 231    target_read_memory_partial).  */
 232
 233 extern int target_xfer_memory PARAMS ((CORE_ADDR memaddr, char *myaddr,
 234                                        int len, int write));
 235
 236 /* From exec.c */
 237
 238 extern void
 239 print_section_info PARAMS ((struct target_ops *, bfd *));
 240
 241 /* Print a line about the current target.  */
 242
 243 #define target_files_info()     \
 244         (*current_target->to_files_info) (current_target)
 245
 246 /* Insert a breakpoint at address ADDR in the target machine.
 247    SAVE is a pointer to memory allocated for saving the
 248    target contents.  It is guaranteed by the caller to be long enough
 249    to save "sizeof BREAKPOINT" bytes.  Result is 0 for success, or
 250    an errno value.  */
 251
 252 #define target_insert_breakpoint(addr, save)    \
 253         (*current_target->to_insert_breakpoint) (addr, save)
 254
 255 /* Remove a breakpoint at address ADDR in the target machine.
 256    SAVE is a pointer to the same save area
 257    that was previously passed to target_insert_breakpoint.
 258    Result is 0 for success, or an errno value.  */
 259
 260 #define target_remove_breakpoint(addr, save)    \
 261         (*current_target->to_remove_breakpoint) (addr, save)
 262
 263 /* Initialize the terminal settings we record for the inferior,
 264    before we actually run the inferior.  */
 265
 266 #define target_terminal_init() \
 267         (*current_target->to_terminal_init) ()
 268
 269 /* Put the inferior's terminal settings into effect.
 270    This is preparation for starting or resuming the inferior.  */
 271
 272 #define target_terminal_inferior() \
 273         (*current_target->to_terminal_inferior) ()
 274
 275 /* Put some of our terminal settings into effect,
 276    enough to get proper results from our output,
 277    but do not change into or out of RAW mode
 278    so that no input is discarded.
 279
 280    After doing this, either terminal_ours or terminal_inferior
 281    should be called to get back to a normal state of affairs.  */
 282
 283 #define target_terminal_ours_for_output() \
 284         (*current_target->to_terminal_ours_for_output) ()
 285
 286 /* Put our terminal settings into effect.
 287    First record the inferior's terminal settings
 288    so they can be restored properly later.  */
 289
 290 #define target_terminal_ours() \
 291         (*current_target->to_terminal_ours) ()
 292
 293 /* Print useful information about our terminal status, if such a thing
 294    exists.  */
 295
 296 #define target_terminal_info(arg, from_tty) \
 297         (*current_target->to_terminal_info) (arg, from_tty)
 298
 299 /* Kill the inferior process.   Make it go away.  */
 300
 301 #define target_kill() \
 302         (*current_target->to_kill) ()
 303
 304 /* Load an executable file into the target process.  This is expected to
 305    not only bring new code into the target process, but also to update
 306    GDB's symbol tables to match.  */
 307
 308 #define target_load(arg, from_tty) \
 309         (*current_target->to_load) (arg, from_tty)
 310
 311 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 312    name.  ADDRP is a CORE_ADDR * pointing to where the value of the symbol
 313    should be returned.  The result is 0 if successful, nonzero if the
 314    symbol does not exist in the target environment.  This function should
 315    not call error() if communication with the target is interrupted, since
 316    it is called from symbol reading, but should return nonzero, possibly
 317    doing a complain().  */
 318
 319 #define target_lookup_symbol(name, addrp)       \
 320   (*current_target->to_lookup_symbol) (name, addrp)
 321
 322 /* Start an inferior process and set inferior_pid to its pid.
 323    EXEC_FILE is the file to run.
 324    ALLARGS is a string containing the arguments to the program.
 325    ENV is the environment vector to pass.  Errors reported with error().
 326    On VxWorks and various standalone systems, we ignore exec_file.  */
 327
 328 #define target_create_inferior(exec_file, args, env)    \
 329         (*current_target->to_create_inferior) (exec_file, args, env)
 330
 331 /* The inferior process has died.  Do what is right.  */
 332
 333 #define target_mourn_inferior() \
 334         (*current_target->to_mourn_inferior) ()
 335
 336 /* Does target have enough data to do a run or attach command? */
 337
 338 #define target_can_run(t) \
 339         ((t)->to_can_run) ()
 340
 341 /* post process changes to signal handling in the inferior.  */
 342
 343 #define target_notice_signals() \
 344         (*current_target->to_notice_signals) ()
 345
 346 /* Pointer to next target in the chain, e.g. a core file and an exec file.  */
 347
 348 #define target_next \
 349         (current_target->to_next)
 350
 351 /* Does the target include all of memory, or only part of it?  This
 352    determines whether we look up the target chain for other parts of
 353    memory if this target can't satisfy a request.  */
 354
 355 #define target_has_all_memory   \
 356         (current_target->to_has_all_memory)
 357
 358 /* Does the target include memory?  (Dummy targets don't.)  */
 359
 360 #define target_has_memory       \
 361         (current_target->to_has_memory)
 362
 363 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 364    we start a process.)  */
 365
 366 #define target_has_stack        \
 367         (current_target->to_has_stack)
 368
 369 /* Does the target have registers?  (Exec files don't.)  */
 370
 371 #define target_has_registers    \
 372         (current_target->to_has_registers)
 373
 374 /* Does the target have execution?  Can we make it jump (through
 375    hoops), or pop its stack a few times?  FIXME: If this is to work that
 376    way, it needs to check whether an inferior actually exists.
 377    remote-udi.c and probably other targets can be the current target
 378    when the inferior doesn't actually exist at the moment.  Right now
 379    this just tells us whether this target is *capable* of execution.  */
 380
 381 #define target_has_execution    \
 382         (current_target->to_has_execution)
 383
 384 /* Converts a process id to a string.  Usually, the string just contains
 385    `process xyz', but on some systems it may contain
 386    `process xyz thread abc'.  */
 387
 388 #ifndef target_pid_to_str
 389 #define target_pid_to_str(PID) \
 390         normal_pid_to_str (PID)
 391 extern char *normal_pid_to_str PARAMS ((int pid));
 392 #endif
 393
 394 /* Routines for maintenance of the target structures...
 395
 396    add_target:   Add a target to the list of all possible targets.
 397
 398    push_target:  Make this target the top of the stack of currently used
 399                  targets, within its particular stratum of the stack.  Result
 400                  is 0 if now atop the stack, nonzero if not on top (maybe
 401                  should warn user).
 402
 403    unpush_target: Remove this from the stack of currently used targets,
 404                  no matter where it is on the list.  Returns 0 if no
 405                  change, 1 if removed from stack.
 406
 407    pop_target:   Remove the top thing on the stack of current targets.  */
 408
 409 extern void
 410 add_target PARAMS ((struct target_ops *));
 411
 412 extern int
 413 push_target PARAMS ((struct target_ops *));
 414
 415 extern int
 416 unpush_target PARAMS ((struct target_ops *));
 417
 418 extern void
 419 target_preopen PARAMS ((int));
 420
 421 extern void
 422 pop_target PARAMS ((void));
 423
 424 /* Struct section_table maps address ranges to file sections.  It is
 425    mostly used with BFD files, but can be used without (e.g. for handling
 426    raw disks, or files not in formats handled by BFD).  */
 427
 428 struct section_table {
 429   CORE_ADDR addr;               /* Lowest address in section */
 430   CORE_ADDR endaddr;            /* 1+highest address in section */
 431   sec_ptr   sec_ptr;            /* BFD section pointer */
 432   bfd      *bfd;                /* BFD file pointer */
 433 };
 434
 435 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
 436    Returns 0 if OK, 1 on error.  */
 437
 438 extern int
 439 build_section_table PARAMS ((bfd *, struct section_table **,
 440                              struct section_table **));
 441
 442 /* From mem-break.c */
 443
 444 extern int
 445 memory_remove_breakpoint PARAMS ((CORE_ADDR, char *));
 446
 447 extern int
 448 memory_insert_breakpoint PARAMS ((CORE_ADDR, char *));
 449
 450 /* From target.c */
 451
 452 void
 453 noprocess PARAMS ((void));
 454
 455 void
 456 find_default_attach PARAMS ((char *, int));
 457
 458 void
 459 find_default_create_inferior PARAMS ((char *, char *, char **));
 460
 461 struct target_ops *
 462 find_core_target PARAMS ((void));
 463 \f
 464 #endif  /* !defined (TARGET_H) */