gdb/gdbserver/target.h

   1 /* Target operations for the remote server for GDB.
   2    Copyright (C) 2002-2013 Free Software Foundation, Inc.
   3
   4    Contributed by MontaVista Software.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef TARGET_H
  22 #define TARGET_H
  23
  24 struct emit_ops;
  25 struct btrace_target_info;
  26 struct buffer;
  27
  28 /* Ways to "resume" a thread.  */
  29
  30 enum resume_kind
  31 {
  32   /* Thread should continue.  */
  33   resume_continue,
  34
  35   /* Thread should single-step.  */
  36   resume_step,
  37
  38   /* Thread should be stopped.  */
  39   resume_stop
  40 };
  41
  42 /* This structure describes how to resume a particular thread (or all
  43    threads) based on the client's request.  If thread is -1, then this
  44    entry applies to all threads.  These are passed around as an
  45    array.  */
  46
  47 struct thread_resume
  48 {
  49   ptid_t thread;
  50
  51   /* How to "resume".  */
  52   enum resume_kind kind;
  53
  54   /* If non-zero, send this signal when we resume, or to stop the
  55      thread.  If stopping a thread, and this is 0, the target should
  56      stop the thread however it best decides to (e.g., SIGSTOP on
  57      linux; SuspendThread on win32).  This is a host signal value (not
  58      enum gdb_signal).  */
  59   int sig;
  60
  61   /* Range to single step within.  Valid only iff KIND is resume_step.
  62
  63      Single-step once, and then continuing stepping as long as the
  64      thread stops in this range.  (If the range is empty
  65      [STEP_RANGE_START == STEP_RANGE_END], then this is a single-step
  66      request.)  */
  67   CORE_ADDR step_range_start;   /* Inclusive */
  68   CORE_ADDR step_range_end;     /* Exclusive */
  69 };
  70
  71 /* Generally, what has the program done?  */
  72 enum target_waitkind
  73   {
  74     /* The program has exited.  The exit status is in
  75        value.integer.  */
  76     TARGET_WAITKIND_EXITED,
  77
  78     /* The program has stopped with a signal.  Which signal is in
  79        value.sig.  */
  80     TARGET_WAITKIND_STOPPED,
  81
  82     /* The program has terminated with a signal.  Which signal is in
  83        value.sig.  */
  84     TARGET_WAITKIND_SIGNALLED,
  85
  86     /* The program is letting us know that it dynamically loaded
  87        something.  */
  88     TARGET_WAITKIND_LOADED,
  89
  90     /* The program has exec'ed a new executable file.  The new file's
  91        pathname is pointed to by value.execd_pathname.  */
  92     TARGET_WAITKIND_EXECD,
  93
  94     /* Nothing of interest to GDB happened, but we stopped anyway.  */
  95     TARGET_WAITKIND_SPURIOUS,
  96
  97     /* An event has occurred, but we should wait again.  In this case,
  98        we want to go back to the event loop and wait there for another
  99        event from the inferior.  */
 100     TARGET_WAITKIND_IGNORE
 101   };
 102
 103 struct target_waitstatus
 104   {
 105     enum target_waitkind kind;
 106
 107     /* Forked child pid, execd pathname, exit status or signal number.  */
 108     union
 109       {
 110         int integer;
 111         enum gdb_signal sig;
 112         ptid_t related_pid;
 113         char *execd_pathname;
 114       }
 115     value;
 116   };
 117
 118 /* Options that can be passed to target_ops->wait.  */
 119
 120 #define TARGET_WNOHANG 1
 121
 122 struct target_ops
 123 {
 124   /* Start a new process.
 125
 126      PROGRAM is a path to the program to execute.
 127      ARGS is a standard NULL-terminated array of arguments,
 128      to be passed to the inferior as ``argv''.
 129
 130      Returns the new PID on success, -1 on failure.  Registers the new
 131      process with the process list.  */
 132
 133   int (*create_inferior) (char *program, char **args);
 134
 135   /* Attach to a running process.
 136
 137      PID is the process ID to attach to, specified by the user
 138      or a higher layer.
 139
 140      Returns -1 if attaching is unsupported, 0 on success, and calls
 141      error() otherwise.  */
 142
 143   int (*attach) (unsigned long pid);
 144
 145   /* Kill inferior PID.  Return -1 on failure, and 0 on success.  */
 146
 147   int (*kill) (int pid);
 148
 149   /* Detach from inferior PID. Return -1 on failure, and 0 on
 150      success.  */
 151
 152   int (*detach) (int pid);
 153
 154   /* The inferior process has died.  Do what is right.  */
 155
 156   void (*mourn) (struct process_info *proc);
 157
 158   /* Wait for inferior PID to exit.  */
 159   void (*join) (int pid);
 160
 161   /* Return 1 iff the thread with process ID PID is alive.  */
 162
 163   int (*thread_alive) (ptid_t pid);
 164
 165   /* Resume the inferior process.  */
 166
 167   void (*resume) (struct thread_resume *resume_info, size_t n);
 168
 169   /* Wait for the inferior process or thread to change state.  Store
 170      status through argument pointer STATUS.
 171
 172      PTID = -1 to wait for any pid to do something, PTID(pid,0,0) to
 173      wait for any thread of process pid to do something.  Return ptid
 174      of child, or -1 in case of error; store status through argument
 175      pointer STATUS.  OPTIONS is a bit set of options defined as
 176      TARGET_W* above.  If options contains TARGET_WNOHANG and there's
 177      no child stop to report, return is
 178      null_ptid/TARGET_WAITKIND_IGNORE.  */
 179
 180   ptid_t (*wait) (ptid_t ptid, struct target_waitstatus *status, int options);
 181
 182   /* Fetch registers from the inferior process.
 183
 184      If REGNO is -1, fetch all registers; otherwise, fetch at least REGNO.  */
 185
 186   void (*fetch_registers) (struct regcache *regcache, int regno);
 187
 188   /* Store registers to the inferior process.
 189
 190      If REGNO is -1, store all registers; otherwise, store at least REGNO.  */
 191
 192   void (*store_registers) (struct regcache *regcache, int regno);
 193
 194   /* Prepare to read or write memory from the inferior process.
 195      Targets use this to do what is necessary to get the state of the
 196      inferior such that it is possible to access memory.
 197
 198      This should generally only be called from client facing routines,
 199      such as gdb_read_memory/gdb_write_memory, or the insert_point
 200      callbacks.
 201
 202      Like `read_memory' and `write_memory' below, returns 0 on success
 203      and errno on failure.  */
 204
 205   int (*prepare_to_access_memory) (void);
 206
 207   /* Undo the effects of prepare_to_access_memory.  */
 208
 209   void (*done_accessing_memory) (void);
 210
 211   /* Read memory from the inferior process.  This should generally be
 212      called through read_inferior_memory, which handles breakpoint shadowing.
 213
 214      Read LEN bytes at MEMADDR into a buffer at MYADDR.
 215
 216      Returns 0 on success and errno on failure.  */
 217
 218   int (*read_memory) (CORE_ADDR memaddr, unsigned char *myaddr, int len);
 219
 220   /* Write memory to the inferior process.  This should generally be
 221      called through write_inferior_memory, which handles breakpoint shadowing.
 222
 223      Write LEN bytes from the buffer at MYADDR to MEMADDR.
 224
 225      Returns 0 on success and errno on failure.  */
 226
 227   int (*write_memory) (CORE_ADDR memaddr, const unsigned char *myaddr,
 228                        int len);
 229
 230   /* Query GDB for the values of any symbols we're interested in.
 231      This function is called whenever we receive a "qSymbols::"
 232      query, which corresponds to every time more symbols (might)
 233      become available.  NULL if we aren't interested in any
 234      symbols.  */
 235
 236   void (*look_up_symbols) (void);
 237
 238   /* Send an interrupt request to the inferior process,
 239      however is appropriate.  */
 240
 241   void (*request_interrupt) (void);
 242
 243   /* Read auxiliary vector data from the inferior process.
 244
 245      Read LEN bytes at OFFSET into a buffer at MYADDR.  */
 246
 247   int (*read_auxv) (CORE_ADDR offset, unsigned char *myaddr,
 248                     unsigned int len);
 249
 250   /* Insert and remove a break or watchpoint.
 251      Returns 0 on success, -1 on failure and 1 on unsupported.
 252      The type is coded as follows:
 253        '0' - software-breakpoint
 254        '1' - hardware-breakpoint
 255        '2' - write watchpoint
 256        '3' - read watchpoint
 257        '4' - access watchpoint  */
 258
 259   int (*insert_point) (char type, CORE_ADDR addr, int len);
 260   int (*remove_point) (char type, CORE_ADDR addr, int len);
 261
 262   /* Returns 1 if target was stopped due to a watchpoint hit, 0 otherwise.  */
 263
 264   int (*stopped_by_watchpoint) (void);
 265
 266   /* Returns the address associated with the watchpoint that hit, if any;
 267      returns 0 otherwise.  */
 268
 269   CORE_ADDR (*stopped_data_address) (void);
 270
 271   /* Reports the text, data offsets of the executable.  This is
 272      needed for uclinux where the executable is relocated during load
 273      time.  */
 274
 275   int (*read_offsets) (CORE_ADDR *text, CORE_ADDR *data);
 276
 277   /* Fetch the address associated with a specific thread local storage
 278      area, determined by the specified THREAD, OFFSET, and LOAD_MODULE.
 279      Stores it in *ADDRESS and returns zero on success; otherwise returns
 280      an error code.  A return value of -1 means this system does not
 281      support the operation.  */
 282
 283   int (*get_tls_address) (struct thread_info *thread, CORE_ADDR offset,
 284                           CORE_ADDR load_module, CORE_ADDR *address);
 285
 286    /* Read/Write from/to spufs using qXfer packets.  */
 287   int (*qxfer_spu) (const char *annex, unsigned char *readbuf,
 288                     unsigned const char *writebuf, CORE_ADDR offset, int len);
 289
 290   /* Fill BUF with an hostio error packet representing the last hostio
 291      error.  */
 292   void (*hostio_last_error) (char *buf);
 293
 294   /* Read/Write OS data using qXfer packets.  */
 295   int (*qxfer_osdata) (const char *annex, unsigned char *readbuf,
 296                        unsigned const char *writebuf, CORE_ADDR offset,
 297                        int len);
 298
 299   /* Read/Write extra signal info.  */
 300   int (*qxfer_siginfo) (const char *annex, unsigned char *readbuf,
 301                         unsigned const char *writebuf,
 302                         CORE_ADDR offset, int len);
 303
 304   int (*supports_non_stop) (void);
 305
 306   /* Enables async target events.  Returns the previous enable
 307      state.  */
 308   int (*async) (int enable);
 309
 310   /* Switch to non-stop (1) or all-stop (0) mode.  Return 0 on
 311      success, -1 otherwise.  */
 312   int (*start_non_stop) (int);
 313
 314   /* Returns true if the target supports multi-process debugging.  */
 315   int (*supports_multi_process) (void);
 316
 317   /* If not NULL, target-specific routine to process monitor command.
 318      Returns 1 if handled, or 0 to perform default processing.  */
 319   int (*handle_monitor_command) (char *);
 320
 321   /* Returns the core given a thread, or -1 if not known.  */
 322   int (*core_of_thread) (ptid_t);
 323
 324   /* Read loadmaps.  Read LEN bytes at OFFSET into a buffer at MYADDR.  */
 325   int (*read_loadmap) (const char *annex, CORE_ADDR offset,
 326                        unsigned char *myaddr, unsigned int len);
 327
 328   /* Target specific qSupported support.  */
 329   void (*process_qsupported) (const char *);
 330
 331   /* Return 1 if the target supports tracepoints, 0 (or leave the
 332      callback NULL) otherwise.  */
 333   int (*supports_tracepoints) (void);
 334
 335   /* Read PC from REGCACHE.  */
 336   CORE_ADDR (*read_pc) (struct regcache *regcache);
 337
 338   /* Write PC to REGCACHE.  */
 339   void (*write_pc) (struct regcache *regcache, CORE_ADDR pc);
 340
 341   /* Return true if THREAD is known to be stopped now.  */
 342   int (*thread_stopped) (struct thread_info *thread);
 343
 344   /* Read Thread Information Block address.  */
 345   int (*get_tib_address) (ptid_t ptid, CORE_ADDR *address);
 346
 347   /* Pause all threads.  If FREEZE, arrange for any resume attempt to
 348      be ignored until an unpause_all call unfreezes threads again.
 349      There can be nested calls to pause_all, so a freeze counter
 350      should be maintained.  */
 351   void (*pause_all) (int freeze);
 352
 353   /* Unpause all threads.  Threads that hadn't been resumed by the
 354      client should be left stopped.  Basically a pause/unpause call
 355      pair should not end up resuming threads that were stopped before
 356      the pause call.  */
 357   void (*unpause_all) (int unfreeze);
 358
 359   /* Cancel all pending breakpoints hits in all threads.  */
 360   void (*cancel_breakpoints) (void);
 361
 362   /* Stabilize all threads.  That is, force them out of jump pads.  */
 363   void (*stabilize_threads) (void);
 364
 365   /* Install a fast tracepoint jump pad.  TPOINT is the address of the
 366      tracepoint internal object as used by the IPA agent.  TPADDR is
 367      the address of tracepoint.  COLLECTOR is address of the function
 368      the jump pad redirects to.  LOCKADDR is the address of the jump
 369      pad lock object.  ORIG_SIZE is the size in bytes of the
 370      instruction at TPADDR.  JUMP_ENTRY points to the address of the
 371      jump pad entry, and on return holds the address past the end of
 372      the created jump pad.  If a trampoline is created by the function,
 373      then TRAMPOLINE and TRAMPOLINE_SIZE return the address and size of
 374      the trampoline, else they remain unchanged.  JJUMP_PAD_INSN is a
 375      buffer containing a copy of the instruction at TPADDR.
 376      ADJUST_INSN_ADDR and ADJUST_INSN_ADDR_END are output parameters that
 377      return the address range where the instruction at TPADDR was relocated
 378      to.  If an error occurs, the ERR may be used to pass on an error
 379      message.  */
 380   int (*install_fast_tracepoint_jump_pad) (CORE_ADDR tpoint, CORE_ADDR tpaddr,
 381                                            CORE_ADDR collector,
 382                                            CORE_ADDR lockaddr,
 383                                            ULONGEST orig_size,
 384                                            CORE_ADDR *jump_entry,
 385                                            CORE_ADDR *trampoline,
 386                                            ULONGEST *trampoline_size,
 387                                            unsigned char *jjump_pad_insn,
 388                                            ULONGEST *jjump_pad_insn_size,
 389                                            CORE_ADDR *adjusted_insn_addr,
 390                                            CORE_ADDR *adjusted_insn_addr_end,
 391                                            char *err);
 392
 393   /* Return the bytecode operations vector for the current inferior.
 394      Returns NULL if bytecode compilation is not supported.  */
 395   struct emit_ops *(*emit_ops) (void);
 396
 397   /* Returns true if the target supports disabling randomization.  */
 398   int (*supports_disable_randomization) (void);
 399
 400   /* Return the minimum length of an instruction that can be safely overwritten
 401      for use as a fast tracepoint.  */
 402   int (*get_min_fast_tracepoint_insn_len) (void);
 403
 404   /* Read solib info on SVR4 platforms.  */
 405   int (*qxfer_libraries_svr4) (const char *annex, unsigned char *readbuf,
 406                                unsigned const char *writebuf,
 407                                CORE_ADDR offset, int len);
 408
 409   /* Return true if target supports debugging agent.  */
 410   int (*supports_agent) (void);
 411
 412   /* Check whether the target supports branch tracing.  */
 413   int (*supports_btrace) (void);
 414
 415   /* Enable branch tracing for @ptid and allocate a branch trace target
 416      information struct for reading and for disabling branch trace.  */
 417   struct btrace_target_info *(*enable_btrace) (ptid_t ptid);
 418
 419   /* Disable branch tracing.  */
 420   int (*disable_btrace) (struct btrace_target_info *tinfo);
 421
 422   /* Read branch trace data into buffer.  We use an int to specify the type
 423      to break a cyclic dependency.  */
 424   void (*read_btrace) (struct btrace_target_info *, struct buffer *, int type);
 425
 426   /* Return true if target supports range stepping.  */
 427   int (*supports_range_stepping) (void);
 428 };
 429
 430 extern struct target_ops *the_target;
 431
 432 void set_target_ops (struct target_ops *);
 433
 434 #define create_inferior(program, args) \
 435   (*the_target->create_inferior) (program, args)
 436
 437 #define myattach(pid) \
 438   (*the_target->attach) (pid)
 439
 440 int kill_inferior (int);
 441
 442 #define detach_inferior(pid) \
 443   (*the_target->detach) (pid)
 444
 445 #define mourn_inferior(PROC) \
 446   (*the_target->mourn) (PROC)
 447
 448 #define mythread_alive(pid) \
 449   (*the_target->thread_alive) (pid)
 450
 451 #define fetch_inferior_registers(regcache, regno)       \
 452   (*the_target->fetch_registers) (regcache, regno)
 453
 454 #define store_inferior_registers(regcache, regno) \
 455   (*the_target->store_registers) (regcache, regno)
 456
 457 #define join_inferior(pid) \
 458   (*the_target->join) (pid)
 459
 460 #define target_supports_non_stop() \
 461   (the_target->supports_non_stop ? (*the_target->supports_non_stop ) () : 0)
 462
 463 #define target_async(enable) \
 464   (the_target->async ? (*the_target->async) (enable) : 0)
 465
 466 #define target_supports_multi_process() \
 467   (the_target->supports_multi_process ? \
 468    (*the_target->supports_multi_process) () : 0)
 469
 470 #define target_process_qsupported(query)                \
 471   do                                                    \
 472     {                                                   \
 473       if (the_target->process_qsupported)               \
 474         the_target->process_qsupported (query);         \
 475     } while (0)
 476
 477 #define target_supports_tracepoints()                   \
 478   (the_target->supports_tracepoints                     \
 479    ? (*the_target->supports_tracepoints) () : 0)
 480
 481 #define target_supports_fast_tracepoints()              \
 482   (the_target->install_fast_tracepoint_jump_pad != NULL)
 483
 484 #define target_get_min_fast_tracepoint_insn_len()       \
 485   (the_target->get_min_fast_tracepoint_insn_len         \
 486    ? (*the_target->get_min_fast_tracepoint_insn_len) () : 0)
 487
 488 #define thread_stopped(thread) \
 489   (*the_target->thread_stopped) (thread)
 490
 491 #define pause_all(freeze)                       \
 492   do                                            \
 493     {                                           \
 494       if (the_target->pause_all)                \
 495         (*the_target->pause_all) (freeze);      \
 496     } while (0)
 497
 498 #define unpause_all(unfreeze)                   \
 499   do                                            \
 500     {                                           \
 501       if (the_target->unpause_all)              \
 502         (*the_target->unpause_all) (unfreeze);  \
 503     } while (0)
 504
 505 #define cancel_breakpoints()                    \
 506   do                                            \
 507     {                                           \
 508       if (the_target->cancel_breakpoints)       \
 509         (*the_target->cancel_breakpoints) ();   \
 510     } while (0)
 511
 512 #define stabilize_threads()                     \
 513   do                                            \
 514     {                                           \
 515       if (the_target->stabilize_threads)        \
 516         (*the_target->stabilize_threads) ();    \
 517     } while (0)
 518
 519 #define install_fast_tracepoint_jump_pad(tpoint, tpaddr,                \
 520                                          collector, lockaddr,           \
 521                                          orig_size,                     \
 522                                          jump_entry,                    \
 523                                          trampoline, trampoline_size,   \
 524                                          jjump_pad_insn,                \
 525                                          jjump_pad_insn_size,           \
 526                                          adjusted_insn_addr,            \
 527                                          adjusted_insn_addr_end,        \
 528                                          err)                           \
 529   (*the_target->install_fast_tracepoint_jump_pad) (tpoint, tpaddr,      \
 530                                                    collector,lockaddr,  \
 531                                                    orig_size, jump_entry, \
 532                                                    trampoline,          \
 533                                                    trampoline_size,     \
 534                                                    jjump_pad_insn,      \
 535                                                    jjump_pad_insn_size, \
 536                                                    adjusted_insn_addr,  \
 537                                                    adjusted_insn_addr_end, \
 538                                                    err)
 539
 540 #define target_emit_ops() \
 541   (the_target->emit_ops ? (*the_target->emit_ops) () : NULL)
 542
 543 #define target_supports_disable_randomization() \
 544   (the_target->supports_disable_randomization ? \
 545    (*the_target->supports_disable_randomization) () : 0)
 546
 547 #define target_supports_agent() \
 548   (the_target->supports_agent ? \
 549    (*the_target->supports_agent) () : 0)
 550
 551 #define target_supports_btrace() \
 552   (the_target->supports_btrace ? (*the_target->supports_btrace) () : 0)
 553
 554 #define target_enable_btrace(ptid) \
 555   (*the_target->enable_btrace) (ptid)
 556
 557 #define target_disable_btrace(tinfo) \
 558   (*the_target->disable_btrace) (tinfo)
 559
 560 #define target_read_btrace(tinfo, buffer, type) \
 561   (*the_target->read_btrace) (tinfo, buffer, type)
 562
 563 #define target_supports_range_stepping() \
 564   (the_target->supports_range_stepping ? \
 565    (*the_target->supports_range_stepping) () : 0)
 566
 567 /* Start non-stop mode, returns 0 on success, -1 on failure.   */
 568
 569 int start_non_stop (int nonstop);
 570
 571 ptid_t mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
 572                int connected_wait);
 573
 574 #define prepare_to_access_memory()              \
 575   (the_target->prepare_to_access_memory         \
 576    ? (*the_target->prepare_to_access_memory) () \
 577    : 0)
 578
 579 #define done_accessing_memory()                         \
 580   do                                                    \
 581     {                                                   \
 582       if (the_target->done_accessing_memory)            \
 583         (*the_target->done_accessing_memory) ();        \
 584     } while (0)
 585
 586 #define target_core_of_thread(ptid)             \
 587   (the_target->core_of_thread ? (*the_target->core_of_thread) (ptid) \
 588    : -1)
 589
 590 int read_inferior_memory (CORE_ADDR memaddr, unsigned char *myaddr, int len);
 591
 592 int write_inferior_memory (CORE_ADDR memaddr, const unsigned char *myaddr,
 593                            int len);
 594
 595 void set_desired_inferior (int id);
 596
 597 const char *target_pid_to_str (ptid_t);
 598
 599 const char *target_waitstatus_to_string (const struct target_waitstatus *);
 600
 601 #endif /* TARGET_H */