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