gdb/target/waitstatus.h

   1 /* Target waitstatus definitions and prototypes.
   2
   3    Copyright (C) 1990-2022 Free Software Foundation, Inc.
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef TARGET_WAITSTATUS_H
  21 #define TARGET_WAITSTATUS_H
  22
  23 #include "diagnostics.h"
  24 #include "gdbsupport/gdb_signals.h"
  25
  26 /* Stuff for target_wait.  */
  27
  28 /* Generally, what has the program done?  */
  29 enum target_waitkind
  30 {
  31   /* The program has exited.  The exit status is in value.integer.  */
  32   TARGET_WAITKIND_EXITED,
  33
  34   /* The program has stopped with a signal.  Which signal is in
  35      value.sig.  */
  36   TARGET_WAITKIND_STOPPED,
  37
  38   /* The program has terminated with a signal.  Which signal is in
  39      value.sig.  */
  40   TARGET_WAITKIND_SIGNALLED,
  41
  42   /* The program is letting us know that it dynamically loaded
  43      something (e.g. it called load(2) on AIX).  */
  44   TARGET_WAITKIND_LOADED,
  45
  46   /* The program has forked.  A "related" process' PTID is in
  47      value.related_pid.  I.e., if the child forks, value.related_pid
  48      is the parent's ID.  */
  49   TARGET_WAITKIND_FORKED,
  50
  51   /* The program has vforked.  A "related" process's PTID is in
  52      value.related_pid.  */
  53   TARGET_WAITKIND_VFORKED,
  54
  55   /* The program has exec'ed a new executable file.  The new file's
  56      pathname is pointed to by value.execd_pathname.  */
  57   TARGET_WAITKIND_EXECD,
  58
  59   /* The program had previously vforked, and now the child is done
  60      with the shared memory region, because it exec'ed or exited.
  61      Note that the event is reported to the vfork parent.  This is
  62      only used if GDB did not stay attached to the vfork child,
  63      otherwise, a TARGET_WAITKIND_EXECD or
  64      TARGET_WAITKIND_EXIT|SIGNALLED event associated with the child
  65      has the same effect.  */
  66   TARGET_WAITKIND_VFORK_DONE,
  67
  68   /* The program has entered or returned from a system call.  On
  69      HP-UX, this is used in the hardware watchpoint implementation.
  70      The syscall's unique integer ID number is in
  71      value.syscall_id.  */
  72   TARGET_WAITKIND_SYSCALL_ENTRY,
  73   TARGET_WAITKIND_SYSCALL_RETURN,
  74
  75   /* Nothing happened, but we stopped anyway.  This perhaps should
  76      be handled within target_wait, but I'm not sure target_wait
  77      should be resuming the inferior.  */
  78   TARGET_WAITKIND_SPURIOUS,
  79
  80   /* An event has occured, but we should wait again.
  81      Remote_async_wait() returns this when there is an event
  82      on the inferior, but the rest of the world is not interested in
  83      it.  The inferior has not stopped, but has just sent some output
  84      to the console, for instance.  In this case, we want to go back
  85      to the event loop and wait there for another event from the
  86      inferior, rather than being stuck in the remote_async_wait()
  87      function.  This way the event loop is responsive to other events,
  88      like for instance the user typing.  */
  89   TARGET_WAITKIND_IGNORE,
  90
  91   /* The target has run out of history information,
  92      and cannot run backward any further.  */
  93   TARGET_WAITKIND_NO_HISTORY,
  94
  95   /* There are no resumed children left in the program.  */
  96   TARGET_WAITKIND_NO_RESUMED,
  97
  98   /* The thread was created.  */
  99   TARGET_WAITKIND_THREAD_CREATED,
 100
 101   /* The thread has exited.  The exit status is in value.integer.  */
 102   TARGET_WAITKIND_THREAD_EXITED,
 103 };
 104
 105 /* Return KIND as a string.  */
 106
 107 static inline const char *
 108 target_waitkind_str (target_waitkind kind)
 109 {
 110 /* Make sure the compiler warns if a new TARGET_WAITKIND enumerator is added
 111    but not handled here.  */
 112 DIAGNOSTIC_PUSH
 113 DIAGNOSTIC_ERROR_SWITCH
 114   switch (kind)
 115   {
 116     case TARGET_WAITKIND_EXITED:
 117       return "EXITED";
 118     case TARGET_WAITKIND_STOPPED:
 119       return "STOPPED";
 120     case TARGET_WAITKIND_SIGNALLED:
 121       return "SIGNALLED";
 122     case TARGET_WAITKIND_LOADED:
 123       return "LOADED";
 124     case TARGET_WAITKIND_FORKED:
 125       return "FORKED";
 126     case TARGET_WAITKIND_VFORKED:
 127       return "VFORKED";
 128     case TARGET_WAITKIND_EXECD:
 129       return "EXECD";
 130     case TARGET_WAITKIND_VFORK_DONE:
 131       return "VFORK_DONE";
 132     case TARGET_WAITKIND_SYSCALL_ENTRY:
 133       return "SYSCALL_ENTRY";
 134     case TARGET_WAITKIND_SYSCALL_RETURN:
 135       return "SYSCALL_RETURN";
 136     case TARGET_WAITKIND_SPURIOUS:
 137       return "SPURIOUS";
 138     case TARGET_WAITKIND_IGNORE:
 139       return "IGNORE";
 140     case TARGET_WAITKIND_NO_HISTORY:
 141       return "NO_HISTORY";
 142     case TARGET_WAITKIND_NO_RESUMED:
 143       return "NO_RESUMED";
 144     case TARGET_WAITKIND_THREAD_CREATED:
 145       return "THREAD_CREATED";
 146     case TARGET_WAITKIND_THREAD_EXITED:
 147       return "THREAD_EXITED";
 148   };
 149 DIAGNOSTIC_POP
 150
 151   gdb_assert_not_reached ("invalid target_waitkind value: %d\n", (int) kind);
 152 }
 153
 154 struct target_waitstatus
 155 {
 156   /* Default constructor.  */
 157   target_waitstatus () = default;
 158
 159   /* Copy constructor.  */
 160
 161   target_waitstatus (const target_waitstatus &other)
 162   {
 163     m_kind = other.m_kind;
 164     m_value = other.m_value;
 165
 166     if (m_kind == TARGET_WAITKIND_EXECD)
 167       m_value.execd_pathname = xstrdup (m_value.execd_pathname);
 168   }
 169
 170   /* Move constructor.  */
 171
 172   target_waitstatus (target_waitstatus &&other)
 173   {
 174     m_kind = other.m_kind;
 175     m_value = other.m_value;
 176
 177     if (m_kind == TARGET_WAITKIND_EXECD)
 178       other.m_value.execd_pathname = nullptr;
 179
 180     other.reset ();
 181   }
 182
 183   /* Copy assignment operator.  */
 184
 185   target_waitstatus &operator= (const target_waitstatus &rhs)
 186   {
 187     this->reset ();
 188     m_kind = rhs.m_kind;
 189     m_value = rhs.m_value;
 190
 191     if (m_kind == TARGET_WAITKIND_EXECD)
 192       m_value.execd_pathname = xstrdup (m_value.execd_pathname);
 193
 194     return *this;
 195   }
 196
 197   /* Move assignment operator.  */
 198
 199   target_waitstatus &operator= (target_waitstatus &&rhs)
 200   {
 201     this->reset ();
 202     m_kind = rhs.m_kind;
 203     m_value = rhs.m_value;
 204
 205     if (m_kind == TARGET_WAITKIND_EXECD)
 206       rhs.m_value.execd_pathname = nullptr;
 207
 208     rhs.reset ();
 209
 210     return *this;
 211   }
 212
 213   /* Destructor.  */
 214
 215   ~target_waitstatus ()
 216   {
 217     this->reset ();
 218   }
 219
 220   /* Setters: set the wait status kind plus any associated data.  */
 221
 222   target_waitstatus &set_exited (int exit_status)
 223   {
 224     this->reset ();
 225     m_kind = TARGET_WAITKIND_EXITED;
 226     m_value.exit_status = exit_status;
 227     return *this;
 228   }
 229
 230   target_waitstatus &set_stopped (gdb_signal sig)
 231   {
 232     this->reset ();
 233     m_kind = TARGET_WAITKIND_STOPPED;
 234     m_value.sig = sig;
 235     return *this;
 236   }
 237
 238   target_waitstatus &set_signalled (gdb_signal sig)
 239   {
 240     this->reset ();
 241     m_kind = TARGET_WAITKIND_SIGNALLED;
 242     m_value.sig = sig;
 243     return *this;
 244   }
 245
 246   target_waitstatus &set_loaded ()
 247   {
 248     this->reset ();
 249     m_kind = TARGET_WAITKIND_LOADED;
 250     return *this;
 251   }
 252
 253   target_waitstatus &set_forked (ptid_t child_ptid)
 254   {
 255     this->reset ();
 256     m_kind = TARGET_WAITKIND_FORKED;
 257     m_value.child_ptid = child_ptid;
 258     return *this;
 259   }
 260
 261   target_waitstatus &set_vforked (ptid_t child_ptid)
 262   {
 263     this->reset ();
 264     m_kind = TARGET_WAITKIND_VFORKED;
 265     m_value.child_ptid = child_ptid;
 266     return *this;
 267   }
 268
 269   target_waitstatus &set_execd (gdb::unique_xmalloc_ptr<char> execd_pathname)
 270   {
 271     this->reset ();
 272     m_kind = TARGET_WAITKIND_EXECD;
 273     m_value.execd_pathname = execd_pathname.release ();
 274     return *this;
 275   }
 276
 277   target_waitstatus &set_vfork_done ()
 278   {
 279     this->reset ();
 280     m_kind = TARGET_WAITKIND_VFORK_DONE;
 281     return *this;
 282   }
 283
 284   target_waitstatus &set_syscall_entry (int syscall_number)
 285   {
 286     this->reset ();
 287     m_kind = TARGET_WAITKIND_SYSCALL_ENTRY;
 288     m_value.syscall_number = syscall_number;
 289     return *this;
 290   }
 291
 292   target_waitstatus &set_syscall_return (int syscall_number)
 293   {
 294     this->reset ();
 295     m_kind = TARGET_WAITKIND_SYSCALL_RETURN;
 296     m_value.syscall_number = syscall_number;
 297     return *this;
 298   }
 299
 300   target_waitstatus &set_spurious ()
 301   {
 302     this->reset ();
 303     m_kind = TARGET_WAITKIND_SPURIOUS;
 304     return *this;
 305   }
 306
 307   target_waitstatus &set_ignore ()
 308   {
 309     this->reset ();
 310     m_kind = TARGET_WAITKIND_IGNORE;
 311     return *this;
 312   }
 313
 314   target_waitstatus &set_no_history ()
 315   {
 316     this->reset ();
 317     m_kind = TARGET_WAITKIND_NO_HISTORY;
 318     return *this;
 319   }
 320
 321   target_waitstatus &set_no_resumed ()
 322   {
 323     this->reset ();
 324     m_kind = TARGET_WAITKIND_NO_RESUMED;
 325     return *this;
 326   }
 327
 328   target_waitstatus &set_thread_created ()
 329   {
 330     this->reset ();
 331     m_kind = TARGET_WAITKIND_THREAD_CREATED;
 332     return *this;
 333   }
 334
 335   target_waitstatus &set_thread_exited (int exit_status)
 336   {
 337     this->reset ();
 338     m_kind = TARGET_WAITKIND_THREAD_EXITED;
 339     m_value.exit_status = exit_status;
 340     return *this;
 341   }
 342
 343   /* Get the kind of this wait status.  */
 344
 345   target_waitkind kind () const
 346   {
 347     return m_kind;
 348   }
 349
 350   /* Getters for the associated data.
 351
 352      Getters can only be used if the wait status is of the appropriate kind.
 353      See the setters above or the assertions below to know which data is
 354      associated to which kind.  */
 355
 356   int exit_status () const
 357   {
 358     gdb_assert (m_kind == TARGET_WAITKIND_EXITED
 359                 || m_kind == TARGET_WAITKIND_THREAD_EXITED);
 360     return m_value.exit_status;
 361   }
 362
 363   gdb_signal sig () const
 364   {
 365     gdb_assert (m_kind == TARGET_WAITKIND_STOPPED
 366                 || m_kind == TARGET_WAITKIND_SIGNALLED);
 367     return m_value.sig;
 368   }
 369
 370   ptid_t child_ptid () const
 371   {
 372     gdb_assert (m_kind == TARGET_WAITKIND_FORKED
 373                 || m_kind == TARGET_WAITKIND_VFORKED);
 374     return m_value.child_ptid;
 375   }
 376
 377   const char *execd_pathname () const
 378   {
 379     gdb_assert (m_kind == TARGET_WAITKIND_EXECD);
 380     return m_value.execd_pathname;
 381   }
 382
 383   int syscall_number () const
 384   {
 385     gdb_assert (m_kind == TARGET_WAITKIND_SYSCALL_ENTRY
 386                 || m_kind == TARGET_WAITKIND_SYSCALL_RETURN);
 387     return m_value.syscall_number;
 388   }
 389
 390   /* Return a pretty printed form of target_waitstatus.
 391
 392      This is only meant to be used in debug messages, not for user-visible
 393      messages.  */
 394   std::string to_string () const;
 395
 396 private:
 397   /* Reset the wait status to its original state.  */
 398   void reset ()
 399   {
 400     if (m_kind == TARGET_WAITKIND_EXECD)
 401       xfree (m_value.execd_pathname);
 402
 403     m_kind = TARGET_WAITKIND_IGNORE;
 404   }
 405
 406   target_waitkind m_kind = TARGET_WAITKIND_IGNORE;
 407
 408   /* Additional information about the event.  */
 409   union
 410     {
 411       /* Exit status */
 412       int exit_status;
 413       /* Signal number */
 414       enum gdb_signal sig;
 415       /* Forked child pid */
 416       ptid_t child_ptid;
 417       /* execd pathname */
 418       char *execd_pathname;
 419       /* Syscall number */
 420       int syscall_number;
 421     } m_value {};
 422 };
 423
 424 /* Extended reasons that can explain why a target/thread stopped for a
 425    trap signal.  */
 426
 427 enum target_stop_reason
 428 {
 429   /* Either not stopped, or stopped for a reason that doesn't require
 430      special tracking.  */
 431   TARGET_STOPPED_BY_NO_REASON,
 432
 433   /* Stopped by a software breakpoint.  */
 434   TARGET_STOPPED_BY_SW_BREAKPOINT,
 435
 436   /* Stopped by a hardware breakpoint.  */
 437   TARGET_STOPPED_BY_HW_BREAKPOINT,
 438
 439   /* Stopped by a watchpoint.  */
 440   TARGET_STOPPED_BY_WATCHPOINT,
 441
 442   /* Stopped by a single step finishing.  */
 443   TARGET_STOPPED_BY_SINGLE_STEP
 444 };
 445
 446 #endif /* TARGET_WAITSTATUS_H */