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