gdb/target.h

   1 /* Interface between GDB and target environments, including files and processes
   2    Copyright 1990, 1991 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.  Written by John Gilmore.
   4
   5 This file is part of GDB.
   6
   7 GDB 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 1, or (at your option)
  10 any later version.
  11
  12 GDB 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 GDB; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /* This include file defines the interface between the main part
  22    of the debugger, and the part which is target-specific, or
  23    specific to the communications interface between us and the
  24    target.
  25
  26    A TARGET is an interface between the debugger and a particular
  27    kind of file or process.  Targets can be STACKED in STRATA,
  28    so that more than one target can potentially respond to a request.
  29    In particular, memory accesses will walk down the stack of targets
  30    until they find a target that is interested in handling that particular
  31    address.  STRATA are artificial boundaries on the stack, within
  32    which particular kinds of targets live.  Strata exist so that
  33    people don't get confused by pushing e.g. a process target and then
  34    a file target, and wondering why they can't see the current values
  35    of variables any more (the file target is handling them and they
  36    never get to the process target).  So when you push a file target,
  37    it goes into the file stratum, which is always below the process
  38    stratum.  */
  39
  40 enum strata {
  41         dummy_stratum,          /* The lowest of the low */
  42         file_stratum,           /* Executable files, etc */
  43         core_stratum,           /* Core dump files */
  44         process_stratum,        /* Executing processes */
  45 };
  46
  47 struct target_ops {
  48         char  *to_shortname;            /* Name this target type */
  49         char  *to_longname;             /* Name for printing */
  50         /* Documentation.  Does not include trailing newline, and
  51            starts with a one-line description (probably similar to
  52            to_longname).  */
  53         char  *to_doc;
  54 #ifdef __STDC__
  55         void (*to_open) (char *name, int from_tty);
  56         void (*to_close) (int quitting);
  57         void (*to_attach) (char *name, int from_tty);
  58         void (*to_detach) (char *args, int from_tty);
  59         void (*to_resume) (int step, int siggnal);
  60         int  (*to_wait)   (int *status);
  61         int  (*to_fetch_registers) (int regno);
  62         int  (*to_store_registers) (int regno);
  63         void (*to_prepare_to_store) ();
  64         void (*to_convert_to_virtual) (int regnum, char *from, char *to);
  65         void (*to_convert_from_virtual) (int regnum, char *from, char *to);
  66         int  (*to_xfer_memory) (CORE_ADDR memaddr, char *myaddr, int len, int w);
  67         void (*to_files_info) ();
  68         int  (*to_insert_breakpoint) (CORE_ADDR addr, char *save);
  69         int  (*to_remove_breakpoint) (CORE_ADDR addr, char *save);
  70         void  (*to_terminal_init) ();
  71         void  (*to_terminal_inferior) ();
  72         void  (*to_terminal_ours_for_output) ();
  73         void  (*to_terminal_ours) ();
  74         void  (*to_terminal_info) (char *arg, int from_tty);
  75         void  (*to_kill) (char *arg, int from_tty);
  76         void  (*to_load) (char *arg, int from_tty);
  77         void  (*to_add_syms) (char *arg, int from_tty);
  78 struct value *(*to_call_function) (struct value *function,
  79                                    int nargs, struct value **args);
  80         int   (*to_lookup_symbol) (char *name, CORE_ADDR *addrp);
  81         void  (*to_create_inferior) (char *exec, char *args, char **env);
  82         void  (*to_mourn_inferior) ();
  83     enum strata to_stratum;
  84 struct target_ops *to_next;
  85         int     to_has_all_memory;
  86         int     to_has_memory;
  87         int     to_has_stack;
  88         int     to_has_registers;
  89         int     to_has_execution;
  90         int     to_magic;
  91 /* Need sub-structure for target machine related rather than comm related? */
  92 #else  /* STDC */
  93         void (*to_open) ();
  94         void (*to_close) ();
  95         void (*to_attach) ();
  96         void (*to_detach) ();
  97         void (*to_resume) ();
  98         int  (*to_wait)   ();
  99         int  (*to_fetch_registers) ();
 100         int  (*to_store_registers) ();
 101         void (*to_prepare_to_store) ();
 102         void (*to_convert_to_virtual) ();
 103         void (*to_convert_from_virtual) ();
 104         int  (*to_xfer_memory) ();
 105         void (*to_files_info) ();
 106         int  (*to_insert_breakpoint) ();
 107         int  (*to_remove_breakpoint) ();
 108         void  (*to_terminal_init) ();
 109         void  (*to_terminal_inferior) ();
 110         void  (*to_terminal_ours_for_output) ();
 111         void  (*to_terminal_ours) ();
 112         void  (*to_terminal_info) ();
 113         void  (*to_kill) ();
 114         void  (*to_load) ();
 115         void  (*to_add_syms) ();
 116 struct value *(*to_call_function) ();
 117         int   (*to_lookup_symbol) ();
 118         void  (*to_create_inferior) ();
 119         void  (*to_mourn_inferior) ();
 120     enum strata to_stratum;
 121 struct target_ops *to_next;
 122         int     to_has_all_memory;
 123         int     to_has_memory;
 124         int     to_has_stack;
 125         int     to_has_registers;
 126         int     to_has_execution;
 127         int     to_magic;
 128 /* Need sub-structure for target machine related rather than comm related? */
 129 #endif
 130 };
 131
 132 /* Magic number for checking ops size.  If a struct doesn't end with this
 133    number, somebody changed the declaration but didn't change all the
 134    places that initialize one.  */
 135
 136 #define OPS_MAGIC       3840
 137
 138 /* The ops structure for our "current" target process.  */
 139
 140 extern struct target_ops        *current_target;
 141
 142 /* Define easy words for doing these operations on our current target.  */
 143
 144 #define target_shortname        (current_target->to_shortname)
 145 #define target_longname         (current_target->to_longname)
 146
 147 /* The open routine takes the rest of the parameters from the command,
 148    and (if successful) pushes a new target onto the stack.
 149    Targets should supply this routine, if only to provide an error message.  */
 150 #define target_open(name, from_tty)     \
 151         (*current_target->to_open) (name, from_tty)
 152
 153 /* Does whatever cleanup is required for a target that we are no longer
 154    going to be calling.  Argument says whether we are quitting gdb and
 155    should not get hung in case of errors, or whether we want a clean
 156    termination even if it takes a while.  This routine is automatically
 157    always called just before a routine is popped off the target stack.
 158    Closing file descriptors and freeing memory are typical things it should
 159    do.  */
 160
 161 #define target_close(quitting)  \
 162         (*current_target->to_close) (quitting)
 163
 164 /* Attaches to a process on the target side.  */
 165
 166 #define target_attach(args, from_tty)   \
 167         (*current_target->to_attach) (args, from_tty)
 168
 169 /* Takes a program previously attached to and detaches it.
 170    The program may resume execution (some targets do, some don't) and will
 171    no longer stop on signals, etc.  We better not have left any breakpoints
 172    in the program or it'll die when it hits one.  ARGS is arguments
 173    typed by the user (e.g. a signal to send the process).  FROM_TTY
 174    says whether to be verbose or not.  */
 175
 176 #define target_detach(args, from_tty)           \
 177         (*current_target->to_detach) (args, from_tty)
 178
 179 /* Resume execution of the target process.  STEP says whether to single-step
 180    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 181    to the target, or zero for no signal.  */
 182
 183 #define target_resume(step, siggnal)    \
 184         (*current_target->to_resume) (step, siggnal)
 185
 186 /* Wait for inferior process to do something.  Return pid of child,
 187    or -1 in case of error; store status through argument pointer STATUS.  */
 188
 189 #define target_wait(status)             \
 190         (*current_target->to_wait) (status)
 191
 192 /* Fetch register REGNO, or all regs if regno == -1.  Result is 0
 193    for success, -1 for problems.  */
 194
 195 #define target_fetch_registers(regno)   \
 196         (*current_target->to_fetch_registers) (regno)
 197
 198 /* Store at least register REGNO, or all regs if REGNO == -1.
 199    It can store as many registers as it wants to, so the entire registers
 200    array must be valid.  Result is 0 for success, -1 for problems.  */
 201
 202 #define target_store_registers(regs)    \
 203         (*current_target->to_store_registers) (regs)
 204
 205 /* Get ready to modify the registers array.  On machines which store
 206    individual registers, this doesn't need to do anything.  On machines
 207    which store all the registers in one fell swoop, this makes sure
 208    that REGISTERS contains all the registers from the program being
 209    debugged.  */
 210
 211 #define target_prepare_to_store()       \
 212         (*current_target->to_prepare_to_store) ()
 213
 214 /* Convert data from raw format for register REGNUM
 215    to virtual format for register REGNUM.  */
 216
 217 #define target_convert_to_virtual(regnum, from, to)     \
 218         (*current_target->to_convert_to_virtual) (regnum, from, to)
 219
 220 /* Convert data from virtual format for register REGNUM
 221    to raw format for register REGNUM.  */
 222
 223 #define target_convert_from_virtual(regnum, from, to)   \
 224         (*current_target->to_convert_from_virtual) (regnum, from, to)
 225
 226 /* Reading and writing memory actually happens through a glue
 227    function which iterates across the various targets.  Result is
 228    0 for success, or an errno value.  */
 229
 230 #ifdef __STDC__
 231 /* Needs defs.h for CORE_ADDR */
 232 extern int target_read_memory(CORE_ADDR memaddr, char *myaddr, int len);
 233 extern int target_write_memory(CORE_ADDR memaddr, char *myaddr, int len);
 234 extern int target_xfer_memory(CORE_ADDR memaddr, char *myaddr, int len,
 235                               int write);
 236 #else
 237 extern int target_read_memory();
 238 extern int target_write_memory();
 239 extern int target_xfer_memory();
 240 #endif
 241
 242 /* Print a line about the current target.  */
 243
 244 #define target_files_info()     \
 245         (*current_target->to_files_info) ()
 246
 247 /* Insert a breakpoint at address ADDR in the target machine.
 248    SAVE is a pointer to memory allocated for saving the
 249    target contents.  It is guaranteed by the caller to be long enough
 250    to save "sizeof BREAKPOINT" bytes.  Result is 0 for success, or
 251    an errno value.  */
 252
 253 #define target_insert_breakpoint(addr, save)    \
 254         (*current_target->to_insert_breakpoint) (addr, save)
 255
 256 /* Remove a breakpoint at address ADDR in the target machine.
 257    SAVE is a pointer to the same save area
 258    that was previously passed to target_insert_breakpoint.
 259    Result is 0 for success, or an errno value.  */
 260
 261 #define target_remove_breakpoint(addr, save)    \
 262         (*current_target->to_remove_breakpoint) (addr, save)
 263
 264 /* Initialize the terminal settings we record for the inferior,
 265    before we actually run the inferior.  */
 266
 267 #define target_terminal_init() \
 268         (*current_target->to_terminal_init) ()
 269
 270 /* Put the inferior's terminal settings into effect.
 271    This is preparation for starting or resuming the inferior.  */
 272
 273 #define target_terminal_inferior() \
 274         (*current_target->to_terminal_inferior) ()
 275
 276 /* Put some of our terminal settings into effect,
 277    enough to get proper results from our output,
 278    but do not change into or out of RAW mode
 279    so that no input is discarded.
 280
 281    After doing this, either terminal_ours or terminal_inferior
 282    should be called to get back to a normal state of affairs.  */
 283
 284 #define target_terminal_ours_for_output() \
 285         (*current_target->to_terminal_ours_for_output) ()
 286
 287 /* Put our terminal settings into effect.
 288    First record the inferior's terminal settings
 289    so they can be restored properly later.  */
 290
 291 #define target_terminal_ours() \
 292         (*current_target->to_terminal_ours) ()
 293
 294 /* Print useful information about our terminal status, if such a thing
 295    exists.  */
 296
 297 #define target_terminal_info(arg, from_tty) \
 298         (*current_target->to_terminal_info) (arg, from_tty)
 299
 300 /* Kill the inferior process.   Make it go away.  */
 301
 302 #define target_kill(arg, from_tty) \
 303         (*current_target->to_kill) (arg, from_tty)
 304
 305 /* Load an executable file into the target process.  This is expected to
 306    not only bring new code into the target process, but also to update
 307    GDB's symbol tables to match.  */
 308
 309 #define target_load(arg, from_tty) \
 310         (*current_target->to_load) (arg, from_tty)
 311
 312 /* Add the symbols from an executable file into GDB's symbol table, as if
 313    the file had been loaded at a particular address (or set of addresses).
 314    This does not change any state in the target system, only in GDB.  */
 315
 316 #define target_add_syms(arg, from_tty) \
 317         (*current_target->to_add_syms) (arg, from_tty)
 318
 319 /* Perform a function call in the inferior.
 320    ARGS is a vector of values of arguments (NARGS of them).
 321    FUNCTION is a value, the function to be called.
 322    Returns a value representing what the function returned.
 323    May fail to return, if a breakpoint or signal is hit
 324    during the execution of the function.  */
 325
 326 #define target_call_function(function, nargs, args)     \
 327   (*current_target->to_call_function) (function, nargs, args)
 328
 329 /* Look up a symbol in the target's symbol table.  NAME is the symbol
 330    name.  ADDRP is a CORE_ADDR * pointing to where the value of the symbol
 331    should be returned.  The result is 0 if successful, nonzero if the
 332    symbol does not exist in the target environment.  This function should
 333    not call error() if communication with the target is interrupted, since
 334    it is called from symbol reading, but should return nonzero, possibly
 335    doing a complain().  */
 336
 337 #define target_lookup_symbol(name, addrp)       \
 338   (*current_target->to_lookup_symbol) (name, addrp)
 339
 340 /* Start an inferior process and set inferior_pid to its pid.
 341    EXEC_FILE is the file to run.
 342    ALLARGS is a string containing the arguments to the program.
 343    ENV is the environment vector to pass.  Errors reported with error().
 344    On VxWorks and various standalone systems, we ignore exec_file.  */
 345
 346 #define target_create_inferior(exec_file, args, env)    \
 347         (*current_target->to_create_inferior) (exec_file, args, env)
 348
 349 /* The inferior process has died.  Do what is right.  */
 350
 351 #define target_mourn_inferior() \
 352         (*current_target->to_mourn_inferior) ()
 353
 354 /* Pointer to next target in the chain, e.g. a core file and an exec file.  */
 355
 356 #define target_next \
 357         (current_target->to_next)
 358
 359 /* Does the target include all of memory, or only part of it?  This
 360    determines whether we look up the target chain for other parts of
 361    memory if this target can't satisfy a request.  */
 362
 363 #define target_has_all_memory   \
 364         (current_target->to_has_all_memory)
 365
 366 /* Does the target include memory?  (Dummy targets don't.)  */
 367
 368 #define target_has_memory       \
 369         (current_target->to_has_memory)
 370
 371 /* Does the target have a stack?  (Exec files don't, VxWorks doesn't, until
 372    we start a process.)  */
 373
 374 #define target_has_stack        \
 375         (current_target->to_has_stack)
 376
 377 /* Does the target have registers?  (Exec files don't.)  */
 378
 379 #define target_has_registers    \
 380         (current_target->to_has_registers)
 381
 382 /* Does the target have execution?  Can we make it jump (through hoops),
 383    or pop its stack a few times, or set breakpoints?  */
 384
 385 #define target_has_execution    \
 386         (current_target->to_has_execution)
 387
 388 /* Routines for maintenance of the target structures...
 389
 390    add_target:   Add a target to the list of all possible targets.
 391
 392    push_target:  Make this target the top of the stack of currently used
 393                  targets, within its particular stratum of the stack.  Result
 394                  is 0 if now atop the stack, nonzero if not on top (maybe
 395                  should warn user).
 396
 397    unpush_target: Remove this from the stack of currently used targets,
 398                  no matter where it is on the list.  Returns 0 if no
 399                  change, 1 if removed from stack.
 400
 401    pop_target:   Remove the top thing on the stack of current targets.  */
 402
 403 #ifdef __STDC__
 404 void add_target (struct target_ops *);
 405 int push_target (struct target_ops *);
 406 int unpush_target (struct target_ops *);
 407 void target_preopen (int);
 408 void pop_target (void);
 409 #else
 410 void add_target ();
 411 int push_target ();
 412 int unpush_target ();
 413 void target_preopen ();
 414 void pop_target ();
 415 #endif