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