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   1                 What has changed in GDB?
   2              (Organized release by release)
   3 
   4 *** Changes since GDB 14
   5 
   6 * Building GDB and GDBserver now requires a C++17 compiler.
   7   For example, GCC 9 or later.
   8 
   9 * GDB index now contains information about the main function.  This speeds up
  10   startup when it is being used for some large binaries.
  11 
  12 * On hosts where threading is available, DWARF reading is now done in
  13   the background, resulting in faster startup.  This can be controlled
  14   using "maint set dwarf synchronous".
  15 
  16 * Changed commands
  17 
  18 disassemble
  19   Attempting to use both the 'r' and 'b' flags with the disassemble
  20   command will now give an error.  Previously the 'b' flag would
  21   always override the 'r' flag.
  22 
  23 maintenance info line-table
  24   Add an EPILOGUE-BEGIN column to the output of the command.  It indicates
  25   if the line is considered the start of the epilgoue, and thus a point at
  26   which the frame can be considered destroyed.
  27 
  28 * New commands
  29 
  30 info missing-debug-handler
  31   List all the registered missing debug handlers.
  32 
  33 enable missing-debug-handler LOCUS HANDLER
  34 disable missing-debug-handler LOCUS HANDLER
  35   Enable or disable a missing debug handler with a name matching the
  36   regular expression HANDLER, in LOCUS.
  37 
  38   LOCUS can be 'global' to operate on global missing debug handler,
  39   'progspace' to operate on handlers within the current program space,
  40   or can be a regular expression which is matched against the filename
  41   of the primary executable in each program space.
  42 
  43 maintenance info linux-lwps
  44   List all LWPs under control of the linux-nat target.
  45 
  46 set remote thread-options-packet
  47 show remote thread-options-packet
  48   Set/show the use of the thread options packet.
  49 
  50 * New features in the GDB remote stub, GDBserver
  51 
  52   ** The --remote-debug and --event-loop-debug command line options
  53      have been removed.
  54 
  55   ** The --debug command line option now takes an optional comma
  56      separated list of components to emit debug for.  The currently
  57      supported components are: all, threads, event-loop, and remote.
  58      If no components are given then threads is assumed.
  59 
  60   ** The 'monitor set remote-debug' and 'monitor set event-loop-debug'
  61      command have been removed.
  62 
  63   ** The 'monitor set debug 0|1' command has been extended to take a
  64      component name, e.g.: 'monitor set debug COMPONENT off|on'.
  65      Possible component names are: all, threads, event-loop, and
  66      remote.
  67 
  68 * Python API
  69 
  70   ** New function gdb.notify_mi(NAME, DATA), that emits custom
  71      GDB/MI async notification.
  72 
  73   ** New read/write attribute gdb.Value.bytes that contains a bytes
  74      object holding the contents of this value.
  75 
  76   ** New module gdb.missing_debug that facilitates dealing with
  77      objfiles that are missing any debug information.
  78 
  79   ** New function gdb.missing_debug.register_handler that can register
  80      an instance of a sub-class of gdb.missing_debug.MissingDebugInfo
  81      as a handler for objfiles that are missing debug information.
  82 
  83   ** New class gdb.missing_debug.MissingDebugInfo which can be
  84      sub-classed to create handlers for objfiles with missing debug
  85      information.
  86 
  87   ** Stop events now have a "details" attribute that holds a
  88      dictionary that carries the same information as an MI "*stopped"
  89      event.
  90 
  91   ** New function gdb.interrupt(), that interrupts GDB as if the user
  92      typed control-c.
  93 
  94   ** New gdb.InferiorThread.ptid_string attribute.  This read-only
  95      attribute contains the string that appears in the 'Target Id'
  96      column of the 'info threads' command output.
  97 
  98   ** It is no longer possible to create new gdb.Progspace object using
  99      'gdb.Progspace()', this will result in a TypeError.  Progspace
 100      objects can still be obtained through calling other API
 101      functions, for example 'gdb.current_progspace()'.
 102 
 103   ** User defined attributes can be added to a gdb.Inferior object,
 104      these will be stored in the object's new Inferior.__dict__
 105      attribute.
 106 
 107   ** User defined attributes can be added to a gdb.InferiorThread
 108      object, these will be stored in the object's new
 109      InferiorThread.__dict__ attribute.
 110 
 111   ** New constants gdb.SYMBOL_TYPE_DOMAIN, gdb.SYMBOL_FUNCTION_DOMAIN,
 112      and gdb.SEARCH_*_DOMAIN corresponding to all the existing symbol
 113      domains.  Symbol lookup can now search in multiple domains at
 114      once, and can also narrowly search for just a type or function.
 115 
 116 * Debugger Adapter Protocol changes
 117 
 118   ** GDB now emits the "process" event.
 119 
 120   ** GDB now supports the "cancel" request.
 121 
 122   ** The "attach" request now supports specifying the program.
 123 
 124   ** New command "set debug dap-log-level" controls DAP logging.
 125 
 126   ** The "set debug dap-log-file" command is now documented.  This
 127      command was available in GDB 14 but not documented.
 128 
 129 * Guile API
 130 
 131   ** New constants SYMBOL_TYPE_DOMAIN, SYMBOL_FUNCTION_DOMAIN, and
 132      SEARCH_*_DOMAIN corresponding to all the existing symbol domains.
 133      Symbol lookup can now search in multiple domains at once, and can
 134      also narrowly search for just a type or function.
 135 
 136 * New remote packets
 137 
 138 New stop reason: clone
 139   Indicates that a clone system call was executed.
 140 
 141 QThreadOptions
 142   Enable/disable optional event reporting, on a per-thread basis.
 143   Currently supported options are GDB_THREAD_OPTION_CLONE, to enable
 144   clone event reporting, and GDB_THREAD_OPTION_EXIT to enable thread
 145   exit event reporting.
 146 
 147 QThreadOptions in qSupported
 148   The qSupported packet allows GDB to inform the stub it supports the
 149   QThreadOptions packet, and the qSupported response can contain the
 150   set of thread options the remote stub supports.
 151 
 152 *** Changes in GDB 14
 153 
 154 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
 155   includes a new 512 bit lookup table register named ZT0.
 156 
 157 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
 158   a new matrix register named ZA, a new thread register TPIDR2 and a new vector
 159   length register SVG (streaming vector granule).  GDB also supports tracking
 160   ZA state across signal frames.
 161 
 162   Some features are still under development or are dependent on ABI specs that
 163   are still in alpha stage.  For example, manual function calls with ZA state
 164   don't have any special handling, and tracking of SVG changes based on
 165   DWARF information is still not implemented, but there are plans to do so in
 166   the future.
 167 
 168 * GDB now recognizes the NO_COLOR environment variable and disables
 169   styling according to the spec.  See https://no-color.org/.
 170   Styling can be re-enabled with "set style enabled on".
 171 
 172 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
 173   has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
 174   string.
 175 
 176 * GDB now has some support for integer types larger than 64 bits.
 177 
 178 * Removed targets and native configurations
 179 
 180   GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x.  The minimum supported
 181   AIX version is now AIX 7.1.
 182 
 183 * Multi-target feature configuration
 184 
 185   GDB now supports the individual configuration of remote targets' feature
 186   sets.  Based on the current selection of a target, the commands 'set remote
 187   <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
 188   configure a target's feature packet and to display its configuration,
 189   respectively.
 190 
 191   The individual packet sizes can be configured and shown using the commands
 192     ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
 193     ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
 194     ** 'show remote memory-read-packet-size'
 195     ** 'show remote memory-write-packet-size'.
 196 
 197   The configuration of the packet itself, as well as the size of a memory-read
 198   or memory-write packet applies to the currently selected target (if
 199   available).  If no target is selected, it applies to future remote
 200   connections.  Similarly, the show commands print the configuration of the
 201   currently selected target.  If no remote target is selected, the default
 202   configuration for future connections is shown.
 203 
 204 * GDB has initial built-in support for the Debugger Adapter Protocol.
 205   This support requires that GDB be built with Python scripting
 206   enabled.
 207 
 208 * For the break command, multiple uses of the 'thread' or 'task'
 209   keywords will now give an error instead of just using the thread or
 210   task id from the last instance of the keyword.  E.g.:
 211     break foo thread 1 thread 2
 212   will now give an error rather than using 'thread 2'.
 213 
 214 * For the watch command, multiple uses of the 'task' keyword will now
 215   give an error instead of just using the task id from the last
 216   instance of the keyword.  E.g.:
 217     watch my_var task 1 task 2
 218   will now give an error rather than using 'task 2'.  The 'thread'
 219   keyword already gave an error when used multiple times with the
 220   watch command, this remains unchanged.
 221 
 222 * The 'set print elements' setting now helps when printing large arrays.
 223   If an array would otherwise exceed max-value-size, but 'print elements'
 224   is set such that the size of elements to print is less than or equal
 225   to 'max-value-size', GDB will now still print the array, however only
 226   'max-value-size' worth of data will be added into the value history.
 227 
 228 * For both the break and watch commands, it is now invalid to use both
 229   the 'thread' and 'task' keywords within the same command.  For
 230   example the following commnds will now give an error:
 231     break foo thread 1 task 1
 232     watch var thread 2 task 3
 233 
 234 * The printf command now accepts a '%V' output format which will
 235   format an expression just as the 'print' command would.  Print
 236   options can be placed withing '[...]' after the '%V' to modify how
 237   the value is printed.  E.g:
 238     printf "%V", some_array
 239     printf "%V[-array-indexes on]", some_array
 240   will print the array without, or with array indexes included, just
 241   as the array would be printed by the 'print' command.  This
 242   functionality is also available for dprintf when dprintf-style is
 243   'gdb'.
 244 
 245 * When the printf command requires a string to be fetched from the
 246   inferior, GDB now uses the existing 'max-value-size' setting to the
 247   limit the memory allocated within GDB.  The default 'max-value-size'
 248   is 64k.  To print longer strings you should increase
 249   'max-value-size'.
 250 
 251 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
 252 
 253 * The Ada 2022 target name symbol ('@') is now supported by the Ada
 254   expression parser.
 255 
 256 * The 'list' command now accepts '.' as an argument, which tells GDB to
 257   print the location around the point of execution within the current frame.
 258   If the inferior hasn't started yet, the command will print around the
 259   beginning of the 'main' function.
 260 
 261 * Using the 'list' command with no arguments in a situation where the
 262   command would attempt to list past the end of the file now warns the
 263   user that the end of file has been reached, refers the user to the
 264   newly added '.' argument
 265 
 266 * Breakpoints can now be inferior-specific.  This is similar to the
 267   existing thread-specific breakpoint support.  Breakpoint conditions
 268   can include the 'inferior' keyword followed by an inferior id (as
 269   displayed in the 'info inferiors' output).  It is invalid to use the
 270   'inferior' keyword with either the 'thread' or 'task' keywords when
 271   creating a breakpoint.
 272 
 273 * New convenience function "$_shell", to execute a shell command and
 274   return the result.  This lets you run shell commands in expressions.
 275   Some examples:
 276 
 277    (gdb) p $_shell("true")
 278    $1 = 0
 279    (gdb) p $_shell("false")
 280    $2 = 1
 281    (gdb) break func if $_shell("some command") == 0
 282 
 283 * Configure changes
 284 
 285 --additional-debug-dirs=PATHs
 286 
 287   Provide a colon-separated list of additional directories to search for
 288   separate debug info.  These directories are added to the default value of
 289   the 'debug-file-directory' GDB parameter.
 290 
 291 * New commands
 292 
 293 set debug breakpoint on|off
 294   show debug breakpoint
 295   Print additional debug messages about breakpoint insertion and removal.
 296 
 297 maintenance print record-instruction [ N ]
 298   Print the recorded information for a given instruction.  If N is not given
 299   prints how GDB would undo the last instruction executed.  If N is negative,
 300   prints how GDB would undo the N-th previous instruction, and if N is
 301   positive, it prints how GDB will redo the N-th following instruction.
 302 
 303 maintenance info frame-unwinders
 304   List the frame unwinders currently in effect, starting with the highest
 305   priority.
 306 
 307 maintenance wait-for-index-cache
 308   Wait until all pending writes to the index cache have completed.
 309 
 310 set always-read-ctf on|off
 311 show always-read-ctf
 312   When off, CTF is only read if DWARF is not present.  When on, CTF is
 313   read regardless of whether DWARF is present.  Off by default.
 314 
 315 info main
 316   Get main symbol to identify entry point into program.
 317 
 318 set tui mouse-events [on|off]
 319 show tui mouse-events
 320   When on (default), mouse clicks control the TUI and can be accessed by
 321   Python extensions.  When off, mouse clicks are handled by the terminal,
 322   enabling terminal-native text selection.
 323 
 324 * MI changes
 325 
 326 ** MI version 1 has been removed.
 327 
 328 ** mi now reports 'no-history' as a stop reason when hitting the end of the
 329    reverse execution history.
 330 
 331 ** When creating a thread-specific breakpoint using the '-p' option,
 332    the -break-insert command would report the 'thread' field twice in
 333    the reply.  The content of both fields was always identical.  This
 334    has now been fixed; the 'thread' field will be reported just once
 335    for thread-specific breakpoints, or not at all for breakpoints
 336    without a thread restriction.  The same is also true for the 'task'
 337    field of an Ada task-specific breakpoint.
 338 
 339 ** It is no longer possible to create a thread-specific breakpoint for
 340    a thread that doesn't exist using '-break-insert -p ID'.  Creating
 341    breakpoints for non-existent threads is not allowed when using the
 342    CLI, that the MI allowed it was a long standing bug, which has now
 343    been fixed.
 344 
 345 ** The '--simple-values' argument to the '-stack-list-arguments',
 346    '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
 347    commands now takes reference types into account: that is, a value is now
 348    considered simple if it is neither an array, structure, or union, nor a
 349    reference to an array, structure, or union.  (Previously all references were
 350    considered simple.)  Support for this feature can be verified by using the
 351    '-list-features' command, which should contain "simple-values-ref-types".
 352 
 353 ** The -break-insert command now accepts a '-g thread-group-id' option
 354    to allow for the creation of inferior-specific breakpoints.
 355 
 356 ** The bkpt tuple, which appears in breakpoint-created notifications,
 357    and in the result of the -break-insert command can now include an
 358    optional 'inferior' field for both the main breakpoint, and each
 359    location, when the breakpoint is inferior-specific.
 360 
 361 * Python API
 362 
 363   ** gdb.ThreadExitedEvent added.  Emits a ThreadEvent.
 364 
 365   ** The gdb.unwinder.Unwinder.name attribute is now read-only.
 366 
 367   ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
 368      now be of type 'str' otherwise a TypeError will be raised.
 369 
 370   ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
 371      values of type 'bool'.  Changing this attribute will now
 372      invalidate GDB's frame-cache, which means GDB will need to
 373      rebuild its frame-cache when next required - either with, or
 374      without the particular unwinder, depending on how 'enabled' was
 375      changed.
 376 
 377   ** New methods added to the gdb.PendingFrame class.  These methods
 378      have the same behaviour as the corresponding methods on
 379      gdb.Frame.  The new methods are:
 380 
 381      - gdb.PendingFrame.name: Return the name for the frame's
 382        function, or None.
 383      - gdb.PendingFrame.is_valid: Return True if the pending frame
 384        object is valid.
 385      - gdb.PendingFrame.pc: Return the $pc register value for this
 386        frame.
 387      - gdb.PendingFrame.language: Return a string containing the
 388        language for this frame, or None.
 389      - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
 390        object for the current location within the pending frame, or
 391        None.
 392      - gdb.PendingFrame.block: Return a gdb.Block for the current
 393        pending frame, or None.
 394      - gdb.PendingFrame.function: Return a gdb.Symbol for the
 395        current pending frame, or None.
 396 
 397   ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
 398      now use either an integer or a gdb.Value object for each of its
 399      'sp', 'pc', and 'special' attributes.
 400 
 401   ** A new class gdb.unwinder.FrameId has been added.  Instances of
 402      this class are constructed with 'sp' (stack-pointer) and 'pc'
 403      (program-counter) values, and can be used as the frame-id when
 404      calling gdb.PendingFrame.create_unwind_info.
 405 
 406   ** It is now no longer possible to sub-class the
 407      gdb.disassembler.DisassemblerResult type.
 408 
 409   ** The Disassembler API from the gdb.disassembler module has been
 410      extended to include styling support:
 411 
 412      - The DisassemblerResult class can now be initialized with a list
 413        of parts.  Each part represents part of the disassembled
 414        instruction along with the associated style information.  This
 415        list of parts can be accessed with the new
 416        DisassemblerResult.parts property.
 417 
 418      - New constants gdb.disassembler.STYLE_* representing all the
 419        different styles part of an instruction might have.
 420 
 421      - New methods DisassembleInfo.text_part and
 422        DisassembleInfo.address_part which are used to create the new
 423        styled parts of a disassembled instruction.
 424 
 425      - Changes are backwards compatible, the older API can still be
 426        used to disassemble instructions without styling.
 427 
 428   ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
 429      GDB/MI command and returns the output as a Python dictionary.
 430 
 431   ** New function gdb.block_signals().  This returns a context manager
 432      that blocks any signals that GDB needs to handle itself.
 433 
 434   ** New class gdb.Thread.  This is a subclass of threading.Thread
 435      that calls gdb.block_signals in its "start" method.
 436 
 437   ** gdb.parse_and_eval now has a new "global_context" parameter.
 438      This can be used to request that the parse only examine global
 439      symbols.
 440 
 441   ** gdb.Inferior now has a new "arguments" attribute.  This holds the
 442      command-line arguments to the inferior, if known.
 443 
 444   ** gdb.Inferior now has a new "main_name" attribute.  This holds the
 445      name of the inferior's "main", if known.
 446 
 447   ** gdb.Inferior now has new methods "clear_env", "set_env", and
 448      "unset_env".  These can be used to modify the inferior's
 449      environment before it is started.
 450 
 451   ** gdb.Value now has the 'assign' method.
 452 
 453   ** gdb.Value now has the 'to_array' method.  This converts an
 454      array-like Value to an array.
 455 
 456   ** gdb.Progspace now has the new method "objfile_for_address".  This
 457      returns the gdb.Objfile, if any, that covers a given address.
 458 
 459   ** gdb.Breakpoint now has an "inferior" attribute.  If the
 460      Breakpoint object is inferior specific then this attribute holds
 461      the inferior-id (an integer).  If the Breakpoint object is not
 462      inferior specific, then this field contains None.  This field can
 463      be written too.
 464 
 465   ** gdb.Type now has the "is_array_like" and "is_string_like"
 466      methods.  These reflect GDB's internal idea of whether a type
 467      might be array- or string-like, even if they do not have the
 468      corresponding type code.
 469 
 470   ** gdb.ValuePrinter is a new class that can be used as the base
 471      class for the result of applying a pretty-printer.  As a base
 472      class, it signals to gdb that the printer may implement new
 473      pretty-printer methods.
 474 
 475   ** New attribute Progspace.symbol_file.  This attribute holds the
 476      gdb.Objfile that corresponds to Progspace.filename (when
 477      Progspace.filename is not None), otherwise, this attribute is
 478      itself None.
 479 
 480   ** New attribute Progspace.executable_filename.  This attribute
 481      holds a string containing a file name set by the "exec-file" or
 482      "file" commands, or None if no executable file is set.  This
 483      isn't the exact string passed by the user to these commands; the
 484      file name will have been partially resolved to an absolute file
 485      name.
 486 
 487   ** A new executable_changed event registry is available.  This event
 488      emits ExecutableChangedEvent objects, which have 'progspace' (a
 489      gdb.Progspace) and 'reload' (a Boolean) attributes.  This event
 490      is emitted when gdb.Progspace.executable_filename changes.
 491 
 492   ** New event registries gdb.events.new_progspace and
 493      gdb.events.free_progspace, these emit NewProgspaceEvent and
 494      FreeProgspaceEvent event types respectively.  Both of these event
 495      types have a single 'progspace' attribute, which is the
 496      gdb.Progspace that is either being added to GDB, or removed from
 497      GDB.
 498 
 499   ** gdb.LazyString now implements the __str__ method.
 500 
 501   ** New method gdb.Frame.static_link that returns the outer frame
 502      of a nested function frame.
 503 
 504 *** Changes in GDB 13
 505 
 506 * MI version 1 is deprecated, and will be removed in GDB 14.
 507 
 508 * GDB now supports dumping memory tag data for AArch64 MTE.  It also supports
 509   reading memory tag data for AArch64 MTE from core files generated by
 510   the gcore command or the Linux kernel.
 511 
 512   When a process uses memory-mapped pages protected by memory tags (for
 513   example, AArch64 MTE), this additional information will be recorded in
 514   the core file in the event of a crash or if GDB generates a core file
 515   from the current process state.  GDB will show this additional information
 516   automatically, or through one of the memory-tag subcommands.
 517 
 518 * Scheduler-locking and new threads
 519 
 520   When scheduler-locking is in effect, only the current thread may run
 521   when the inferior is resumed.  However, previously, new threads
 522   created by the resumed thread would still be able to run free.  Now,
 523   they are held stopped.
 524 
 525 * "info breakpoints" now displays enabled breakpoint locations of
 526   disabled breakpoints as in the "y-" state.  For example:
 527 
 528    (gdb) info breakpoints
 529    Num     Type           Disp Enb Address            What
 530    1       breakpoint     keep n   <MULTIPLE>
 531    1.1                         y-  0x00000000000011b6 in ...
 532    1.2                         y-  0x00000000000011c2 in ...
 533    1.3                         n   0x00000000000011ce in ...
 534 
 535 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
 536   aarch64 architectures.
 537 
 538 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
 539 
 540 * Remove support for building against Python 2, it is now only possible to
 541   build GDB against Python 3.
 542 
 543 * DBX mode has been removed.
 544 
 545 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
 546   emit to indicate where a breakpoint should be placed to break in a function
 547   past its prologue.
 548 
 549 * Completion now also offers "NUMBER" for "set" commands that accept
 550   a numeric argument and the "unlimited" keyword.  For example:
 551 
 552    (gdb) set width <TAB>
 553    NUMBER     unlimited
 554 
 555   and consequently:
 556 
 557    (gdb) complete set width
 558    set width NUMBER
 559    set width unlimited
 560 
 561 * Disassembler styling using libopcodes.  GDB now supports
 562   disassembler styling using libopcodes.  This is only available for
 563   some targets (currently x86 and RISC-V).  For unsupported targets
 564   Python Pygments is still used.  For supported targets, libopcodes
 565   styling is used by default.
 566 
 567 * The Windows native target now supports target async.
 568 
 569 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
 570 
 571 * The format of 'disassemble /r' and 'record instruction-history /r'
 572   has changed.  The instruction bytes could now be grouped together,
 573   and displayed in the endianness of the instruction.  This is the
 574   same layout as used by GNU objdump when disassembling.
 575 
 576   There is now 'disassemble /b' and 'record instruction-history /b'
 577   which will always display the instructions bytes one at a time in
 578   memory order, that is, the byte at the lowest address first.
 579 
 580   For both /r and /b GDB is now better at using whitespace in order to
 581   align the disassembled instruction text.
 582 
 583 * The TUI no longer styles the source and assembly code highlighted by
 584   the current position indicator by default.  You can however
 585   re-enable styling using the new "set style tui-current-position"
 586   command.
 587 
 588 * New convenience variable $_inferior_thread_count contains the number
 589   of live threads in the current inferior.
 590 
 591 * When a breakpoint with multiple code locations is hit, GDB now prints
 592   the code location using the syntax <breakpoint_number>.<location_number>
 593   such as in:
 594      Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
 595 
 596 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
 597   and $_hit_locno to the hit breakpoint number and code location number.
 598   This allows to disable the last hit breakpoint using
 599      (gdb) disable $_hit_bpnum
 600    or disable only the specific breakpoint code location using
 601      (gdb) disable $_hit_bpnum.$_hit_locno
 602   These commands can be used inside the command list of a breakpoint to
 603   automatically disable the just encountered breakpoint (or the just
 604   encountered specific breakpoint code location).
 605   When a breakpoint has only one location, $_hit_locno is set to 1 so that
 606      (gdb) disable $_hit_bpnum.$_hit_locno
 607   and
 608      (gdb) disable $_hit_bpnum
 609   are both disabling the breakpoint.
 610 
 611 * New commands
 612 
 613 maintenance set ignore-prologue-end-flag on|off
 614 maintenance show ignore-prologue-end-flag
 615   This setting, which is off by default, controls whether GDB ignores the
 616   PROLOGUE-END flag from the line-table when skipping prologue.  This can be
 617   used to force GDB to use prologue analyzers if the line-table is constructed
 618   from erroneous debug information.
 619 
 620 set print nibbles [on|off]
 621 show print nibbles
 622   This controls whether the 'print/t' command will display binary values
 623   in groups of four bits, known as "nibbles".  The default is 'off'.
 624 
 625 maintenance set libopcodes-styling on|off
 626 maintenance show libopcodes-styling
 627   These can be used to force off libopcodes based styling, the Python
 628   Pygments styling will then be used instead.
 629 
 630 set style disassembler comment
 631 show style disassembler comment
 632 set style disassembler immediate
 633 show style disassembler immediate
 634 set style disassembler mnemonic
 635 show style disassembler mnemonic
 636 set style disassembler register
 637 show style disassembler register
 638 set style disassembler address
 639 show style disassembler address
 640 set style disassembler symbol
 641 show style disassembler symbol
 642   For targets that support libopcodes based styling, these settings
 643   control how various aspects of the disassembler output are styled.
 644   The 'disassembler address' and 'disassembler symbol' styles are
 645   aliases for the 'address' and 'function' styles respectively.
 646 
 647 maintenance print frame-id [ LEVEL ]
 648   Print GDB's internal frame-id for the frame at LEVEL.  If LEVEL is
 649   not given, then print the frame-id for the currently selected frame.
 650 
 651 set debug infcall on|off
 652 show debug infcall
 653   Print additional debug messages about inferior function calls.
 654 
 655 set debug solib on|off
 656 show debug solib
 657   Print additional debug messages about shared library handling.
 658 
 659 set style tui-current-position [on|off]
 660   Whether to style the source and assembly code highlighted by the
 661   TUI's current position indicator.  The default is off.
 662 
 663 set print characters LIMIT
 664 show print characters
 665   This new setting is like 'set print elements', but controls how many
 666   characters of a string are printed.  This functionality used to be
 667   covered by 'set print elements', but it can be controlled separately
 668   now.  LIMIT can be set to a numerical value to request that particular
 669   character count, to 'unlimited' to print all characters of a string,
 670   or to 'elements', which is also the default, to follow the setting of
 671  'set print elements' as it used to be.
 672 
 673 print -characters LIMIT
 674   This new option to the 'print' command has the same effect as a temporary
 675   use of 'set print characters'.
 676 
 677 * Changed commands
 678 
 679 document user-defined
 680   It is now possible to document user-defined aliases.
 681   When a user-defined alias is documented, the help and apropos commands
 682   use the provided documentation instead of the documentation of the
 683   aliased command.
 684   Documenting a user-defined alias is particularly useful when the alias
 685   is a set of nested 'with' commands to avoid showing the help of
 686   the with command for an alias that will in fact launch the
 687   last command given in the nested commands.
 688 
 689 maintenance info line-table
 690   Add a PROLOGUE-END column to the output which indicates that an
 691   entry corresponds to an address where a breakpoint should be placed
 692   to be at the first instruction past a function's prologue.
 693 
 694 * Removed commands
 695 
 696 set debug aix-solib on|off
 697 show debug aix-solib
 698 set debug solib-frv on|off
 699 show debug solib-frv
 700   Removed in favor of "set/show debug solib".
 701 
 702 maintenance info program-spaces
 703   This command now includes a 'Core File' column which indicates the
 704   name of the core file associated with each program space.
 705 
 706 * New targets
 707 
 708 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
 709 
 710 GNU/Linux/CSKY (gdbserver) csky*-*linux*
 711 
 712 AMDGPU amdgcn-*-*
 713 
 714 * MI changes
 715 
 716  ** The async record stating the stopped reason 'breakpoint-hit' now
 717     contains an optional field locno giving the code location number
 718     when the breakpoint has multiple code locations.
 719 
 720 * Python API
 721 
 722   ** GDB will now reformat the doc string for gdb.Command and
 723      gdb.Parameter sub-classes to remove unnecessary leading
 724      whitespace from each line before using the string as the help
 725      output.
 726 
 727   ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
 728      that formats ADDRESS as 'address <symbol+offset>', where symbol is
 729      looked up in PROGSPACE, and ARCHITECTURE is used to format address.
 730      This is the same format that GDB uses when printing address, symbol,
 731      and offset information from the disassembler.
 732 
 733   ** New function gdb.current_language that returns the name of the
 734      current language.  Unlike gdb.parameter('language'), this will
 735      never return 'auto'.
 736 
 737   ** New method gdb.Frame.language that returns the name of the
 738      frame's language.
 739 
 740   ** New Python API for wrapping GDB's disassembler:
 741 
 742      - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
 743        DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
 744        ARCH is either None or a string containing a bfd architecture
 745        name.  DISASSEMBLER is registered as a disassembler for
 746        architecture ARCH, or for all architectures if ARCH is None.
 747        The previous disassembler registered for ARCH is returned, this
 748        can be None if no previous disassembler was registered.
 749 
 750      - gdb.disassembler.Disassembler is the class from which all
 751        disassemblers should inherit.  Its constructor takes a string,
 752        a name for the disassembler, which is currently only used in
 753        some debug output.  Sub-classes should override the __call__
 754        method to perform disassembly, invoking __call__ on this base
 755        class will raise an exception.
 756 
 757      - gdb.disassembler.DisassembleInfo is the class used to describe
 758        a single disassembly request from GDB.  An instance of this
 759        class is passed to the __call__ method of
 760        gdb.disassembler.Disassembler and has the following read-only
 761        attributes: 'address', and 'architecture', as well as the
 762        following method: 'read_memory'.
 763 
 764      - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
 765        calls GDB's builtin disassembler on INFO, which is a
 766        gdb.disassembler.DisassembleInfo object.  MEMORY_SOURCE is
 767        optional, its default value is None.  If MEMORY_SOURCE is not
 768        None then it must be an object that has a 'read_memory' method.
 769 
 770      - gdb.disassembler.DisassemblerResult is a class that can be used
 771        to wrap the result of a call to a Disassembler.  It has
 772        read-only attributes 'length' and 'string'.
 773 
 774   ** gdb.Objfile now has an attribute named "is_file".  This is True
 775      if the objfile comes from a file, and False otherwise.
 776 
 777   ** New function gdb.print_options that returns a dictionary of the
 778      prevailing print options, in the form accepted by
 779      gdb.Value.format_string.
 780 
 781   ** gdb.Value.format_string now uses the format provided by 'print',
 782      if it is called during a 'print' or other similar operation.
 783 
 784   ** gdb.Value.format_string now accepts the 'summary' keyword.  This
 785      can be used to request a shorter representation of a value, the
 786      way that 'set print frame-arguments scalars' does.
 787 
 788   ** New Python type gdb.BreakpointLocation.
 789      The new attribute 'locations' of gdb.Breakpoint returns a list of
 790      gdb.BreakpointLocation objects specifying the locations where the
 791      breakpoint is inserted into the debuggee.
 792 
 793   ** The gdb.register_window_type method now restricts the set of
 794      acceptable window names.  The first character of a window's name
 795      must start with a character in the set [a-zA-Z], every subsequent
 796      character of a window's name must be in the set [-_.a-zA-Z0-9].
 797 
 798 * New features in the GDB remote stub, GDBserver
 799 
 800   ** GDBserver is now supported on LoongArch GNU/Linux.
 801   
 802   ** GDBserver is now supported on CSKY GNU/Linux.
 803 
 804 * LoongArch floating-point support
 805 
 806 GDB now supports floating-point on LoongArch GNU/Linux.
 807 
 808 * AMD GPU ROCm debugging support
 809 
 810 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
 811 platform.
 812 
 813 *** Changes in GDB 12
 814 
 815 * DBX mode is deprecated, and will be removed in GDB 13
 816 
 817 * GDB 12 is the last release of GDB that will support building against
 818   Python 2.  From GDB 13, it will only be possible to build GDB itself
 819   with Python 3 support.
 820 
 821 * The disable-randomization setting now works on Windows.
 822 
 823 * Improved C++ template support
 824 
 825   GDB now treats functions/types involving C++ templates like it does function
 826   overloads.  Users may omit parameter lists to set breakpoints on families of
 827   template functions, including types/functions composed of multiple template types:
 828 
 829   (gdb) break template_func(template_1, int)
 830 
 831   The above will set breakpoints at every function `template_func' where
 832   the first function parameter is any template type named `template_1' and
 833   the second function parameter is `int'.
 834 
 835   TAB completion also gains similar improvements.
 836 
 837 * The FreeBSD native target now supports async mode.
 838 
 839 * Configure changes
 840 
 841 --enable-threading
 842 
 843   Enable or disable multithreaded symbol loading.  This is enabled
 844   by default, but passing --disable-threading or --enable-threading=no
 845   to configure will disable it.
 846 
 847   Disabling this can cause a performance penalty when there are a lot of
 848   symbols to load, but is useful for debugging purposes.
 849 
 850 * New commands
 851 
 852 maint set backtrace-on-fatal-signal on|off
 853 maint show backtrace-on-fatal-signal
 854   This setting is 'on' by default.  When 'on' GDB will print a limited
 855   backtrace to stderr in the situation where GDB terminates with a
 856   fatal signal.  This only supported on some platforms where the
 857   backtrace and backtrace_symbols_fd functions are available.
 858 
 859 set source open on|off
 860 show source open
 861   This setting, which is on by default, controls whether GDB will try
 862   to open source code files.  Switching this off will stop GDB trying
 863   to open and read source code files, which can be useful if the files
 864   are located over a slow network connection.
 865 
 866 set varsize-limit
 867 show varsize-limit
 868   These are now deprecated aliases for "set max-value-size" and
 869   "show max-value-size".
 870 
 871 task apply [all | TASK-IDS...] [FLAG]... COMMAND
 872   Like "thread apply", but applies COMMAND to Ada tasks.
 873 
 874 watch [...] task ID
 875   Watchpoints can now be restricted to a specific Ada task.
 876 
 877 maint set internal-error backtrace on|off
 878 maint show internal-error backtrace
 879 maint set internal-warning backtrace on|off
 880 maint show internal-warning backtrace
 881   GDB can now print a backtrace of itself when it encounters either an
 882   internal-error, or an internal-warning.  This is on by default for
 883   internal-error and off by default for internal-warning.
 884 
 885 set logging on|off
 886   Deprecated and replaced by "set logging enabled on|off".
 887 
 888 set logging enabled on|off
 889 show logging enabled
 890   These commands set or show whether logging is enabled or disabled.
 891 
 892 exit
 893   You can now exit GDB by using the new command "exit", in addition to
 894   the existing "quit" command.
 895 
 896 set debug threads on|off
 897 show debug threads
 898   Print additional debug messages about thread creation and deletion.
 899 
 900 set debug linux-nat on|off
 901 show debug linux-nat
 902   These new commands replaced the old 'set debug lin-lwp' and 'show
 903   debug lin-lwp' respectively.  Turning this setting on prints debug
 904   messages relating to GDB's handling of native Linux inferiors.
 905 
 906 maint flush source-cache
 907   Flush the contents of the source code cache.
 908 
 909 maint set gnu-source-highlight enabled on|off
 910 maint show gnu-source-highlight enabled
 911   Whether GDB should use the GNU Source Highlight library for adding
 912   styling to source code.  When off, the library will not be used, even
 913   when available.  When GNU Source Highlight isn't used, or can't add
 914   styling to a particular source file, then the Python Pygments
 915   library will be used instead.
 916 
 917 set suppress-cli-notifications (on|off)
 918 show suppress-cli-notifications
 919   This controls whether printing the notifications is suppressed for CLI.
 920   CLI notifications occur when you change the selected context
 921   (i.e., the current inferior, thread and/or the frame), or when
 922   the program being debugged stops (e.g., because of hitting a
 923   breakpoint, completing source-stepping, an interrupt, etc.).
 924 
 925 set style disassembler enabled on|off
 926 show style disassembler enabled
 927   If GDB is compiled with Python support, and the Python Pygments
 928   package is available, then, when this setting is on, disassembler
 929   output will have styling applied.
 930 
 931 set ada source-charset
 932 show ada source-charset
 933   Set the character set encoding that is assumed for Ada symbols.  Valid
 934   values for this follow the values that can be passed to the GNAT
 935   compiler via the '-gnati' option.  The default is ISO-8859-1.
 936 
 937 tui layout
 938 tui focus
 939 tui refresh
 940 tui window height
 941   These are the new names for the old 'layout', 'focus', 'refresh',
 942   and 'winheight' tui commands respectively.  The old names still
 943   exist as aliases to these new commands.
 944 
 945 tui window width
 946 winwidth
 947   The new command 'tui window width', and the alias 'winwidth' allow
 948   the width of a tui window to be adjusted when windows are laid out
 949   in horizontal mode.
 950 
 951 set debug tui on|off
 952 show debug tui
 953   Control the display of debug output about GDB's tui.
 954 
 955 * Changed commands
 956 
 957 print
 958   Printing of floating-point values with base-modifying formats like
 959   /x has been changed to display the underlying bytes of the value in
 960   the desired base.  This was GDB's documented behavior, but was never
 961   implemented correctly.
 962 
 963 maint packet
 964   This command can now print a reply, if the reply includes
 965   non-printable characters.  Any non-printable characters are printed
 966   as escaped hex, e.g. \x?? where '??' is replaces with the value of
 967   the non-printable character.
 968 
 969 clone-inferior
 970   The clone-inferior command now ensures that the TTY, CMD and ARGS
 971   settings are copied from the original inferior to the new one.
 972   All modifications to the environment variables done using the 'set
 973   environment' or 'unset environment' commands are also copied to the new
 974   inferior.
 975 
 976 set debug lin-lwp on|off
 977 show debug lin-lwp
 978   These commands have been removed from GDB.  The new command 'set
 979   debug linux-nat' and 'show debug linux-nat' should be used
 980   instead.
 981 
 982 info win
 983   This command now includes information about the width of the tui
 984   windows in its output.
 985 
 986 layout
 987 focus
 988 refresh
 989 winheight
 990   These commands are now aliases for the 'tui layout', 'tui focus',
 991   'tui refresh', and 'tui window height' commands respectively.
 992 
 993 * GDB's Ada parser now supports an extension for specifying the exact
 994   byte contents of a floating-point literal.  This can be useful for
 995   setting floating-point registers to a precise value without loss of
 996   precision.  The syntax is an extension of the based literal syntax.
 997   Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
 998   of the floating-point type, and the "f" is the marker for floating
 999   point.
1000 
1001 * MI changes
1002 
1003  ** The '-add-inferior' with no option flags now inherits the
1004     connection of the current inferior, this restores the behaviour of
1005     GDB as it was prior to GDB 10.
1006 
1007  ** The '-add-inferior' command now accepts a '--no-connection'
1008     option, which causes the new inferior to start without a
1009     connection.
1010 
1011  ** The default version of the MI interpreter is now 4 (-i=mi4).
1012 
1013  ** The "script" field in breakpoint output (which is syntactically
1014     incorrect in MI 3 and below) has changed in MI 4 to become a list.
1015     This affects the following commands and events:
1016 
1017         - -break-insert
1018         - -break-info
1019         - =breakpoint-created
1020         - =breakpoint-modified
1021 
1022     The -fix-breakpoint-script-output command can be used to enable
1023     this behavior with previous MI versions.
1024 
1025 * New targets
1026 
1027 GNU/Linux/LoongArch             loongarch*-*-linux*
1028 
1029 * Removed targets
1030 
1031 S+core                          score-*-*
1032 
1033 * Python API
1034 
1035   ** New function gdb.add_history(), which takes a gdb.Value object
1036      and adds the value it represents to GDB's history list.  An
1037      integer, the index of the new item in the history list, is
1038      returned.
1039 
1040   ** New function gdb.history_count(), which returns the number of
1041      values in GDB's value history.
1042 
1043   ** New gdb.events.gdb_exiting event.  This event is called with a
1044      gdb.GdbExitingEvent object which has the read-only attribute
1045      'exit_code', which contains the value of the GDB exit code.  This
1046      event is triggered once GDB decides it is going to exit, but
1047      before GDB starts to clean up its internal state.
1048 
1049   ** New function gdb.architecture_names(), which returns a list
1050      containing all of the possible Architecture.name() values.  Each
1051      entry is a string.
1052 
1053   ** New function gdb.Architecture.integer_type(), which returns an
1054      integer type given a size and a signed-ness.
1055 
1056   ** New gdb.TargetConnection object type that represents a connection
1057      (as displayed by the 'info connections' command).  A sub-class,
1058      gdb.RemoteTargetConnection, is used to represent 'remote' and
1059      'extended-remote' connections.
1060 
1061   ** The gdb.Inferior type now has a 'connection' property which is an
1062      instance of gdb.TargetConnection, the connection used by this
1063      inferior.  This can be None if the inferior has no connection.
1064 
1065   ** New 'gdb.events.connection_removed' event registry, which emits a
1066      'gdb.ConnectionEvent' when a connection is removed from GDB.
1067      This event has a 'connection' property, a gdb.TargetConnection
1068      object for the connection being removed.
1069 
1070   ** New gdb.connections() function that returns a list of all
1071      currently active connections.
1072 
1073   ** New gdb.RemoteTargetConnection.send_packet(PACKET) method.  This
1074      is equivalent to the existing 'maint packet' CLI command; it
1075      allows a user specified packet to be sent to the remote target.
1076 
1077   ** New function gdb.host_charset(), returns a string, which is the
1078      name of the current host charset.
1079 
1080   ** New gdb.set_parameter(NAME, VALUE).  This sets the gdb parameter
1081      NAME to VALUE.
1082 
1083   ** New gdb.with_parameter(NAME, VALUE).  This returns a context
1084      manager that temporarily sets the gdb parameter NAME to VALUE,
1085      then resets it when the context is exited.
1086 
1087   ** The gdb.Value.format_string method now takes a 'styling'
1088      argument, which is a boolean.  When true, the returned string can
1089      include escape sequences to apply styling.  The styling will only
1090      be present if styling is otherwise turned on in GDB (see 'help
1091      set styling').  When false, which is the default if the argument
1092      is not given, then no styling is applied to the returned string.
1093 
1094   ** New read-only attribute gdb.InferiorThread.details, which is
1095      either a string, containing additional, target specific thread
1096      state information, or None, if there is no such additional
1097      information.
1098 
1099   ** New read-only attribute gdb.Type.is_scalar, which is True for
1100      scalar types, and False for all other types.
1101 
1102   ** New read-only attribute gdb.Type.is_signed.  This attribute
1103      should only be read when Type.is_scalar is True, and will be True
1104      for signed types, and False for all other types.  Attempting to
1105      read this attribute for non-scalar types will raise a ValueError.
1106 
1107   ** It is now possible to add GDB/MI commands implemented in Python.
1108 
1109 * New features in the GDB remote stub, GDBserver
1110 
1111   ** GDBserver is now supported on OpenRISC GNU/Linux.
1112 
1113 * New native configurations
1114 
1115 GNU/Linux/OpenRISC              or1k*-*-linux*
1116 
1117 *** Changes in GDB 11
1118 
1119 * The 'set disassembler-options' command now supports specifying options
1120   for the ARC target.
1121 
1122 * GDB now supports general memory tagging functionality if the underlying
1123   architecture supports the proper primitives and hooks.  Currently this is
1124   enabled only for AArch64 MTE.
1125 
1126   This includes:
1127 
1128   - Additional information when the inferior crashes with a SIGSEGV caused by
1129     a memory tag violation.
1130 
1131   - A new modifier 'm' for the "x" command, which displays allocation tags for a
1132     particular memory range.
1133 
1134   - Display of memory tag mismatches by "print", for addresses and
1135     pointers, if memory tagging is supported by the architecture.
1136 
1137 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1138   Library).
1139 
1140 * MI changes
1141 
1142  ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1143 
1144     The MI -break-insert and -dprintf-insert commands now support a
1145     new "--qualified" option that makes GDB interpret a specified
1146     function name as a complete fully-qualified name.  This is the
1147     equivalent of the CLI's "break -qualified" and "dprintf
1148     -qualified".
1149 
1150  ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1151 
1152     The MI -break-insert and -dprintf-insert commands now support a
1153     '--force-condition' flag to forcibly define a condition even when
1154     the condition is invalid at all locations of the breakpoint.  This
1155     is equivalent to the '-force-condition' flag of the CLI's "break"
1156     command.
1157 
1158  ** '-break-condition --force'
1159 
1160     The MI -break-condition command now supports a '--force' flag to
1161     forcibly define a condition even when the condition is invalid at
1162     all locations of the selected breakpoint.  This is equivalent to
1163     the '-force' flag of the CLI's "cond" command.
1164 
1165  ** '-file-list-exec-source-files [--group-by-objfile]
1166                                   [--basename | --dirname]
1167                                   [--] [REGEXP]'
1168 
1169     The existing -file-list-exec-source-files command now takes an
1170     optional REGEXP which is used to filter the source files that are
1171     included in the results.
1172 
1173     By default REGEXP is matched against the full filename of the
1174     source file. When one of --basename or --dirname is given then
1175     REGEXP is only matched against the specified part of the full
1176     source filename.
1177 
1178     When the optional --group-by-objfile flag is used the output
1179     format is changed, the results are now a list of object files
1180     (executable and libraries) with the source files that are
1181     associated with each object file.
1182 
1183     The results from -file-list-exec-source-files now include a
1184     'debug-fully-read' field which takes the value 'true' or 'false'.
1185     A 'true' value indicates the source file is from a compilation
1186     unit that has had its debug information fully read in by GDB, a
1187     value of 'false' indicates GDB has only performed a partial scan
1188     of the debug information so far.
1189 
1190 * GDB now supports core file debugging for x86_64 Cygwin programs.
1191 
1192 * GDB will now look for the .gdbinit file in a config directory before
1193   looking for ~/.gdbinit.  The file is searched for in the following
1194   locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1195   $HOME/.gdbinit.  On Apple hosts the search order is instead:
1196   $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1197 
1198 * GDB now supports fixed point types which are described in DWARF
1199   as base types with a fixed-point encoding.  Additionally, support
1200   for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1201   been added.
1202 
1203   For Ada, this allows support for fixed point types without requiring
1204   the use of the GNAT encoding (based on information added to the type's
1205   name following a GNAT-specific format).
1206 
1207 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1208   or ~/.gdbearlyinit if these files are present.  These files are
1209   processed earlier than any of the other initialization files and
1210   can affect parts of GDB's startup that previously had already been
1211   completed before the initialization files were read, for example
1212   styling of the initial GDB greeting.
1213 
1214 * GDB now has two new options "--early-init-command" and
1215   "--early-init-eval-command" with corresponding short options "-eix"
1216   and "-eiex" that allow options (that would normally appear in a
1217   gdbearlyinit file) to be passed on the command line.
1218 
1219 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1220   now understood by GDB, and can be used to describe the vector
1221   registers of a target.  The precise requirements of this register
1222   feature are documented in the GDB manual.
1223 
1224 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1225   supported by GDB and describes a new VPR register from the ARM MVE
1226   (Helium) extension. See the GDB manual for more information.
1227 
1228 * TUI improvements
1229 
1230   ** TUI windows now support mouse actions.  The mouse wheel scrolls
1231      the appropriate window.
1232 
1233   ** Key combinations that do not have a specific action on the
1234      focused window are passed to GDB.  For example, you now can use
1235      Ctrl-Left/Ctrl-Right to move between words in the command window
1236      regardless of which window is in focus.  Previously you would
1237      need to focus on the command window for such key combinations to
1238      work.
1239 
1240 * New commands
1241 
1242 set debug event-loop
1243 show debug event-loop
1244   Control the display of debug output about GDB's event loop.
1245 
1246 set print memory-tag-violations
1247 show print memory-tag-violations
1248   Control whether to display additional information about memory tag violations
1249   when printing pointers and addresses.  Architecture support for memory
1250   tagging is required for this option to have an effect.
1251 
1252 maintenance flush symbol-cache
1253 maintenance flush register-cache
1254   These new commands are equivalent to the already existing commands
1255   'maintenance flush-symbol-cache' and 'flushregs' respectively.
1256 
1257 maintenance flush dcache
1258   A new command to flush the dcache.
1259 
1260 maintenance info target-sections
1261   Print GDB's internal target sections table.
1262 
1263 maintenance info jit
1264   Print the JIT code objects in the inferior known to GDB.
1265 
1266 memory-tag show-logical-tag POINTER
1267   Print the logical tag for POINTER.
1268 memory-tag with-logical-tag POINTER TAG
1269   Print POINTER with logical tag TAG.
1270 memory-tag show-allocation-tag ADDRESS
1271   Print the allocation tag for ADDRESS.
1272 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1273   Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1274 memory-tag check POINTER
1275   Validate that POINTER's logical tag matches the allocation tag.
1276 
1277 set startup-quietly on|off
1278 show startup-quietly
1279   When 'on', this causes GDB to act as if "-silent" were passed on the
1280   command line.  This command needs to be added to an early
1281   initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1282   affect GDB.
1283 
1284 set print type hex on|off
1285 show print type hex
1286   When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1287   and offsets of struct members.  When 'off', decimal notation is used.
1288 
1289 set python ignore-environment on|off
1290 show python ignore-environment
1291   When 'on', this causes GDB's builtin Python to ignore any
1292   environment variables that would otherwise affect how Python
1293   behaves.  This command needs to be added to an early initialization
1294   file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1295 
1296 set python dont-write-bytecode auto|on|off
1297 show python dont-write-bytecode
1298   When 'on', this causes GDB's builtin Python to not write any
1299   byte-code (.pyc files) to disk.  This command needs to be added to
1300   an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1301   order to affect GDB.  When 'off' byte-code will always be written.
1302   When set to 'auto' (the default) Python will check the
1303   PYTHONDONTWRITEBYTECODE environment variable.
1304 
1305 * Changed commands
1306 
1307 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1308       [-force-condition] [if CONDITION]
1309   This command would previously refuse setting a breakpoint if the
1310   CONDITION expression is invalid at a location.  It now accepts and
1311   defines the breakpoint if there is at least one location at which
1312   the CONDITION is valid.  The locations for which the CONDITION is
1313   invalid, are automatically disabled.  If CONDITION is invalid at all
1314   of the locations, setting the breakpoint is still rejected.  However,
1315   the '-force-condition' flag can be used in this case for forcing GDB to
1316   define the breakpoint, making all the current locations automatically
1317   disabled.  This may be useful if the user knows the condition will
1318   become meaningful at a future location, e.g. due to a shared library
1319   load.
1320 
1321 condition [-force] N COND
1322   The behavior of this command is changed the same way for the 'break'
1323   command as explained above.  The '-force' flag can be used to force
1324   GDB into defining the condition even when COND is invalid for all the
1325   current locations of breakpoint N.
1326 
1327 flushregs
1328 maintenance flush-symbol-cache
1329   These commands are deprecated in favor of the new commands
1330   'maintenance flush register-cache' and 'maintenance flush
1331   symbol-cache' respectively.
1332 
1333 set style version foreground COLOR
1334 set style version background COLOR
1335 set style version intensity VALUE
1336   Control the styling of GDB's version number text.
1337 
1338 inferior [ID]
1339   When the ID parameter is omitted, then this command prints information
1340   about the current inferior.  When the ID parameter is present, the
1341   behavior of the command is unchanged and have the inferior ID become
1342   the current inferior.
1343 
1344 maintenance info sections
1345   The ALLOBJ keyword has been replaced with an -all-objects command
1346   line flag.  It is now possible to filter which sections are printed
1347   even when -all-objects is passed.
1348 
1349 ptype[/FLAGS] TYPE | EXPRESSION
1350   The 'ptype' command has two new flags.  When '/x' is set, hexadecimal
1351   notation is used when printing sizes and offsets of struct members.
1352   When '/d' is set, decimal notation is used when printing sizes and
1353   offsets of struct members.  Default behavior is given by 'show print
1354   type hex'.
1355 
1356 info sources
1357   The info sources command output has been restructured.  The results
1358   are now based around a list of objfiles (executable and libraries),
1359   and for each objfile the source files that are part of that objfile
1360   are listed.
1361 
1362 * Removed targets and native configurations
1363 
1364 ARM Symbian                     arm*-*-symbianelf*
1365 
1366 * New remote packets
1367 
1368 qMemTags
1369   Request the remote to send allocation tags for a particular memory range.
1370 QMemTags
1371   Request the remote to store the specified allocation tags to the requested
1372   memory range.
1373 
1374 * Guile API
1375 
1376   ** Improved support for rvalue reference values:
1377      TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1378      value-referenced-value procedure now handles rvalue reference
1379      values.
1380 
1381   ** New procedures for obtaining value variants:
1382      value-reference-value, value-rvalue-reference-value and
1383      value-const-value.
1384 
1385   ** Temporary breakpoints can now be created with make-breakpoint and
1386      tested for using breakpoint-temporary?.
1387 
1388 * Python API
1389 
1390   ** Inferior objects now contain a read-only 'connection_num' attribute that
1391      gives the connection number as seen in 'info connections' and
1392      'info inferiors'.
1393 
1394   ** New method gdb.Frame.level() which returns the stack level of the
1395      frame object.
1396 
1397   ** New method gdb.PendingFrame.level() which returns the stack level
1398      of the frame object.
1399 
1400   ** When hitting a catchpoint, the Python API will now emit a
1401      gdb.BreakpointEvent rather than a gdb.StopEvent.  The
1402      gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1403 
1404   ** Python TUI windows can now receive mouse click events.  If the
1405      Window object implements the click method, it is called for each
1406      mouse click event in this window.
1407 
1408 *** Changes in GDB 10
1409 
1410 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1411   and "org.gnu.gdb.arc.aux".  The old names are still supported but
1412   must be considered obsolete.  They will be deprecated after some
1413   grace period.
1414 
1415 * Help and apropos commands will now show the documentation of a
1416   command only once, even if that command has one or more aliases.
1417   These commands now show the command name, then all of its aliases,
1418   and finally the description of the command.
1419 
1420 * 'help aliases' now shows only the user defined aliases.  GDB predefined
1421   aliases are shown together with their aliased command.
1422 
1423 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1424   debugging information as well as source code.
1425 
1426   When built with debuginfod, GDB can automatically query debuginfod
1427   servers for the separate debug files and source code of the executable
1428   being debugged.
1429 
1430   To build GDB with debuginfod, pass --with-debuginfod to configure (this
1431   requires libdebuginfod, the debuginfod client library).
1432 
1433   debuginfod is distributed with elfutils, starting with version 0.178.
1434 
1435   You can get the latest version from https://sourceware.org/elfutils.
1436 
1437 * Multi-target debugging support
1438 
1439   GDB now supports debugging multiple target connections
1440   simultaneously.  For example, you can now have each inferior
1441   connected to different remote servers running in different machines,
1442   or have one inferior debugging a local native process, an inferior
1443   debugging a core dump, etc.
1444 
1445   This support is experimental and comes with some limitations -- you
1446   can only resume multiple targets simultaneously if all targets
1447   support non-stop mode, and all remote stubs or servers must support
1448   the same set of remote protocol features exactly.  See also "info
1449   connections" and "add-inferior -no-connection" below, and "maint set
1450   target-non-stop" in the user manual.
1451 
1452 * New features in the GDB remote stub, GDBserver
1453 
1454   ** GDBserver is now supported on ARC GNU/Linux.
1455 
1456   ** GDBserver is now supported on RISC-V GNU/Linux.
1457 
1458   ** GDBserver no longer supports these host triplets:
1459 
1460     i[34567]86-*-lynxos*
1461     powerpc-*-lynxos*
1462     i[34567]86-*-nto*
1463     bfin-*-*linux*
1464     crisv32-*-linux*
1465     cris-*-linux*
1466     m32r*-*-linux*
1467     tilegx-*-linux*
1468     arm*-*-mingw32ce*
1469     i[34567]86-*-mingw32ce*
1470 
1471 * Debugging MS-Windows processes now sets $_exitsignal when the
1472   inferior is terminated by a signal, instead of setting $_exitcode.
1473 
1474 * Multithreaded symbol loading has now been enabled by default on systems
1475   that support it (see entry for GDB 9, below), providing faster
1476   performance for programs with many symbols.
1477 
1478 * The $_siginfo convenience variable now also works on Windows targets,
1479   and will display the EXCEPTION_RECORD of the last handled exception.
1480 
1481 * TUI windows can now be arranged horizontally.
1482 
1483 * The command history filename can now be set to the empty string
1484   either using 'set history filename' or by setting 'GDBHISTFILE=' in
1485   the environment.  The effect of setting this filename to the empty
1486   string is that GDB will not try to load any previous command
1487   history.
1488 
1489 * On Windows targets, it is now possible to debug 32-bit programs with a
1490   64-bit GDB.
1491 
1492 * New commands
1493 
1494 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1495 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1496   Set or show the option 'exec-file-mismatch'.  When GDB attaches to a
1497   running process, this new option indicates whether to detect
1498   a mismatch between the current executable file loaded by GDB and the
1499   executable file used to start the process.  If 'ask', the default,
1500   display a warning and ask the user whether to load the process
1501   executable file; if 'warn', just display a warning; if 'off', don't
1502   attempt to detect a mismatch.
1503 
1504 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1505   Define a new TUI layout, specifying its name and the windows that
1506   will be displayed.
1507 
1508 maintenance print xml-tdesc [FILE]
1509   Prints the current target description as an XML document.  If the
1510   optional FILE is provided (which is an XML target description) then
1511   the target description is read from FILE into GDB, and then
1512   reprinted.
1513 
1514 maintenance print core-file-backed-mappings
1515   Prints file-backed mappings loaded from a core file's note section.
1516   Output is expected to be similar to that of "info proc mappings".
1517 
1518 set debug fortran-array-slicing on|off
1519 show debug fortran-array-slicing
1520   Print debugging when taking slices of Fortran arrays.
1521 
1522 set fortran repack-array-slices on|off
1523 show fortran repack-array-slices
1524   When taking slices from Fortran arrays and strings, if the slice is
1525   non-contiguous within the original value then, when this option is
1526   on, the new value will be repacked into a single contiguous value.
1527   When this option is off, then the value returned will consist of a
1528   descriptor that describes the slice within the memory of the
1529   original parent value.
1530 
1531 * Changed commands
1532 
1533 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1534   The alias command can now specify default args for an alias.
1535   GDB automatically prepends the alias default args to the argument list
1536   provided explicitly by the user.
1537   For example, to have a backtrace with full details, you can define
1538   an alias 'bt_ALL' as
1539   'alias bt_ALL = backtrace -entry-values both -frame-arg all
1540      -past-main -past-entry -full'.
1541   Alias default arguments can also use a set of nested 'with' commands,
1542   e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1543   defines the alias pp10 that will pretty print a maximum of 10 elements
1544   of the given expression (if the expression is an array).
1545 
1546 * New targets
1547 
1548 GNU/Linux/RISC-V (gdbserver)    riscv*-*-linux*
1549 BPF                             bpf-unknown-none
1550 Z80                             z80-unknown-*
1551 
1552 * Python API
1553 
1554   ** gdb.register_window_type can be used to implement new TUI windows
1555      in Python.
1556 
1557   ** Dynamic types can now be queried.  gdb.Type has a new attribute,
1558      "dynamic", and gdb.Type.sizeof can be None for a dynamic type.  A
1559      field of a dynamic type may have None for its "bitpos" attribute
1560      as well.
1561 
1562   ** Commands written in Python can be in the "TUI" help class by
1563      registering with the new constant gdb.COMMAND_TUI.
1564 
1565   ** New method gdb.PendingFrame.architecture () to retrieve the
1566      architecture of the pending frame.
1567 
1568   ** New gdb.Architecture.registers method that returns a
1569      gdb.RegisterDescriptorIterator object, an iterator that returns
1570      gdb.RegisterDescriptor objects.  The new RegisterDescriptor is a
1571      way to query the registers available for an architecture.
1572 
1573   ** New gdb.Architecture.register_groups method that returns a
1574      gdb.RegisterGroupIterator object, an iterator that returns
1575      gdb.RegisterGroup objects.  The new RegisterGroup is a way to
1576      discover the available register groups.
1577 
1578 * Guile API
1579 
1580   ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1581 
1582   ** Procedures 'memory-port-read-buffer-size',
1583      'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1584      and 'set-memory-port-write-buffer-size!' are deprecated.  When
1585      using Guile 2.2 and later, users who need to control the size of
1586      a memory port's internal buffer can use the 'setvbuf' procedure.
1587 
1588 *** Changes in GDB 9
1589 
1590 * 'thread-exited' event is now available in the annotations interface.
1591 
1592 * New built-in convenience variables $_gdb_major and $_gdb_minor
1593   provide the GDB version.  They are handy for conditionally using
1594   features available only in or since specific GDB versions, in
1595   scripts that should work error-free with many different versions,
1596   such as in system-wide init files.
1597 
1598 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1599   $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1600   of the GDB settings and the GDB maintenance settings.  They are handy
1601   for changing the logic of user defined commands depending on the
1602   current GDB settings.
1603 
1604 * GDB now supports Thread Local Storage (TLS) variables on several
1605   FreeBSD architectures (amd64, i386, powerpc, riscv).  Other
1606   architectures require kernel changes.  TLS is not yet supported for
1607   amd64 and i386 process core dumps.
1608 
1609 * Support for Pointer Authentication (PAC) on AArch64 Linux.  Return
1610   addresses that required unmasking are shown in the backtrace with the
1611   postfix [PAC].
1612 
1613 * Two new convenience functions $_cimag and $_creal that extract the
1614   imaginary and real parts respectively from complex numbers.
1615 
1616 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1617   provide the exitcode or exit status of the shell commands launched by
1618   GDB commands such as "shell", "pipe" and "make".
1619 
1620 * The command define-prefix can now define user defined prefix commands.
1621   User defined commands can now be defined using these user defined prefix
1622   commands.
1623 
1624 * Command names can now use the . character.
1625 
1626 * The RX port now supports XML target descriptions.
1627 
1628 * GDB now shows the Ada task names at more places, e.g. in task switching
1629   messages.
1630 
1631 * GDB can now be compiled with Python 3 on Windows.
1632 
1633 * New convenience variable $_ada_exception holds the address of the
1634   Ada exception being thrown.  This is set by Ada-related catchpoints.
1635 
1636 * GDB can now place breakpoints on nested functions and subroutines in
1637   Fortran code.  The '::' operator can be used between parent and
1638   child scopes when placing breakpoints, for example:
1639 
1640     (gdb) break outer_function::inner_function
1641 
1642   The 'outer_function::' prefix is only needed if 'inner_function' is
1643   not visible in the current scope.
1644 
1645 * In addition to the system-wide gdbinit file, if configured with
1646  --with-system-gdbinit-dir, GDB will now also load files in that directory
1647  as system gdbinit files, unless the -nx or -n flag is provided.  Files
1648  with extensions .gdb, .py and .scm are supported as long as GDB was
1649  compiled with support for that language.
1650 
1651 * GDB now supports multithreaded symbol loading for higher performance.
1652   This feature is still in testing, so it is disabled by default.  You
1653   can turn it on using 'maint set worker-threads unlimited'.
1654 
1655 * Python API
1656 
1657   ** The gdb.Value type has a new method 'format_string' which returns a
1658      string representing the value.  The formatting is controlled by the
1659      optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1660      'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1661      'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1662 
1663   ** gdb.Type has a new property 'objfile' which returns the objfile the
1664      type was defined in.
1665 
1666   ** The frame information printed by the python frame filtering code
1667      is now consistent with what the 'backtrace' command prints when
1668      there are no filters, or when the 'backtrace' '-no-filters' option
1669      is given.
1670 
1671   ** The new function gdb.lookup_static_symbol can be used to look up
1672      symbols with static linkage.
1673 
1674   ** The new function gdb.lookup_static_symbols can be used to look up
1675      all static symbols with static linkage.
1676 
1677   ** gdb.Objfile has new methods 'lookup_global_symbol' and
1678      'lookup_static_symbol' to lookup a symbol from this objfile only.
1679 
1680   ** gdb.Block now supports the dictionary syntax for accessing symbols in
1681      this block (e.g. block['local_variable']).
1682 
1683 * New commands
1684 
1685 | [COMMAND] | SHELL_COMMAND
1686 | -d DELIM COMMAND DELIM SHELL_COMMAND
1687 pipe [COMMAND] | SHELL_COMMAND
1688 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1689   Executes COMMAND and sends its output to SHELL_COMMAND.
1690   With no COMMAND, repeat the last executed command
1691   and send its output to SHELL_COMMAND.
1692 
1693 define-prefix COMMAND
1694   Define or mark a command as a user-defined prefix command.
1695   
1696 with SETTING [VALUE] [-- COMMAND]
1697 w SETTING [VALUE] [-- COMMAND]
1698   Temporarily set SETTING, run COMMAND, and restore SETTING.
1699   Usage: with SETTING -- COMMAND
1700   With no COMMAND, repeats the last executed command.
1701   SETTING is any GDB setting you can change with the "set"
1702   subcommands.  For example, 'with language c -- print someobj'
1703   temporarily switches to the C language in order to print someobj.
1704   Settings can be combined: 'w lang c -- w print elements unlimited --
1705   usercmd' switches to the C language and runs usercmd with no limit
1706   of array elements to print.
1707 
1708 maint with SETTING [VALUE] [-- COMMAND]
1709   Like "with", but works with "maintenance set" settings.
1710 
1711 set may-call-functions [on|off]
1712 show may-call-functions
1713   This controls whether GDB will attempt to call functions in
1714   the program, such as with expressions in the print command.  It
1715   defaults to on.  Calling functions in the program being debugged
1716   can have undesired side effects.  It is now possible to forbid
1717   such function calls.  If function calls are forbidden, GDB will throw
1718   an error when a command (such as print expression) calls a function
1719   in the program.
1720 
1721 set print finish [on|off]
1722 show print finish
1723   This controls whether the `finish' command will display the value
1724   that is returned by the current function.  When `off', the value is
1725   still entered into the value history, but it is not printed.  The
1726   default is `on'.
1727 
1728 set print max-depth
1729 show print max-depth
1730   Allows deeply nested structures to be simplified when printing by
1731   replacing deeply nested parts (beyond the max-depth) with ellipses.
1732   The default max-depth is 20, but this can be set to unlimited to get
1733   the old behavior back.
1734 
1735 set print raw-values [on|off]
1736 show print raw-values
1737   By default, GDB applies the enabled pretty printers when printing a
1738   value.  This allows to ignore the enabled pretty printers for a series
1739   of commands.  The default is 'off'.
1740 
1741 set logging debugredirect [on|off]
1742   By default, GDB debug output will go to both the terminal and the logfile.
1743   Set if you want debug output to go only to the log file.
1744 
1745 set style title foreground COLOR
1746 set style title background COLOR
1747 set style title intensity VALUE
1748   Control the styling of titles.
1749 
1750 set style highlight foreground COLOR
1751 set style highlight background COLOR
1752 set style highlight intensity VALUE
1753   Control the styling of highlightings.
1754 
1755 maint set worker-threads
1756 maint show worker-threads
1757   Control the number of worker threads that can be used by GDB.  The
1758   default is 0.  "unlimited" lets GDB choose a number that is
1759   reasonable.  Currently worker threads are only used when demangling
1760   the names of linker symbols.
1761 
1762 set style tui-border foreground COLOR
1763 set style tui-border background COLOR
1764   Control the styling of TUI borders.
1765 
1766 set style tui-active-border foreground COLOR
1767 set style tui-active-border background COLOR
1768   Control the styling of the active TUI border.
1769 
1770 maint set test-settings KIND
1771 maint show test-settings KIND
1772   A set of commands used by the testsuite for exercising the settings
1773   infrastructure.
1774 
1775 maint set tui-resize-message [on|off]
1776 maint show tui-resize-message
1777   Control whether GDB prints a message each time the terminal is
1778   resized when in TUI mode.  This is primarily useful for testing the
1779   TUI.
1780 
1781 set print frame-info [short-location|location|location-and-address
1782                         |source-and-location|source-line|auto]
1783 show print frame-info
1784   This controls what frame information is printed by the commands printing
1785   a frame.  This setting will e.g. influence the behaviour of 'backtrace',
1786   'frame', 'stepi'.  The python frame filtering also respect this setting.
1787   The 'backtrace' '-frame-info' option can override this global setting.
1788 
1789 set tui compact-source
1790 show tui compact-source
1791 
1792   Enable the "compact" display mode for the TUI source window.  The
1793   compact display uses only as much space as is needed for the line
1794   numbers in the current file, and only a single space to separate the
1795   line numbers from the source.
1796 
1797 info modules [-q] [REGEXP]
1798   Return a list of Fortran modules matching REGEXP, or all modules if
1799   no REGEXP is given.
1800 
1801 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1802   Return a list of functions within all modules, grouped by module.
1803   The list of functions can be restricted with the optional regular
1804   expressions.  MODULE_REGEXP matches against the module name,
1805   TYPE_REGEXP matches against the function type signature, and REGEXP
1806   matches against the function name.
1807 
1808 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1809   Return a list of variables within all modules, grouped by module.
1810   The list of variables can be restricted with the optional regular
1811   expressions.  MODULE_REGEXP matches against the module name,
1812   TYPE_REGEXP matches against the variable type, and REGEXP matches
1813   against the variable name.
1814 
1815 set debug remote-packet-max-chars
1816 show debug remote-packet-max-chars
1817   Controls the number of characters to output in a remote packet when using
1818   "set debug remote".
1819   The default is 512 bytes.
1820 
1821 info connections
1822   Lists the target connections currently in use.
1823 
1824 * Changed commands
1825 
1826 help
1827   The "help" command uses the title style to enhance the
1828   readibility of its output by styling the classes and
1829   command names.
1830 
1831 apropos [-v] REGEXP
1832   Similarly to "help", the "apropos" command also uses the
1833   title style for the command names.  "apropos" accepts now
1834   a flag "-v" (verbose) to show the full documentation
1835   of matching commands and to use the highlight style to mark
1836   the documentation parts matching REGEXP.
1837 
1838 printf
1839 eval
1840   The GDB printf and eval commands can now print C-style and Ada-style
1841   string convenience variables without calling functions in the program.
1842   This allows to do formatted printing of strings without having
1843   a running inferior, or when debugging a core dump.
1844 
1845 info sources [-dirname | -basename] [--] [REGEXP]
1846   This command has now optional arguments to only print the files
1847   whose names match REGEXP.  The arguments -dirname and -basename
1848   allow to restrict matching respectively to the dirname and basename
1849   parts of the files.
1850 
1851 show style
1852   The "show style" and its subcommands are now styling
1853   a style name in their output using its own style, to help
1854   the user visualize the different styles.
1855 
1856 set print frame-arguments
1857   The new value 'presence' indicates to only indicate the presence of
1858   arguments using ..., instead of printing argument names and values.
1859 
1860 set print raw-frame-arguments
1861 show print raw-frame-arguments
1862 
1863   These commands replace the similarly-named "set/show print raw
1864   frame-arguments" commands (now with a dash instead of a space).  The
1865   old commands are now deprecated and may be removed in a future
1866   release.
1867 
1868 add-inferior [-no-connection]
1869   The add-inferior command now supports a "-no-connection" flag that
1870   makes the new inferior start with no target connection associated.
1871   By default, the new inferior inherits the target connection of the
1872   current inferior.  See also "info connections".
1873 
1874 info inferior
1875   This command's output now includes a new "Connection" column
1876   indicating which target connection an inferior is bound to.  See
1877   "info connections" above.
1878 
1879 maint test-options require-delimiter
1880 maint test-options unknown-is-error
1881 maint test-options unknown-is-operand
1882 maint show test-options-completion-result
1883   Commands used by the testsuite to validate the command options
1884   framework.
1885 
1886 focus, winheight, +, -, >, <
1887   These commands are now case-sensitive.
1888 
1889 * New command options, command completion
1890 
1891   GDB now has a standard infrastructure to support dash-style command
1892   options ('-OPT').  One benefit is that commands that use it can
1893   easily support completion of command line arguments.  Try "CMD
1894   -[TAB]" or "help CMD" to find options supported by a command.  Over
1895   time, we intend to migrate most commands to this infrastructure.  A
1896   number of commands got support for new command options in this
1897   release:
1898 
1899   ** The "print" and "compile print" commands now support a number of
1900      options that allow overriding relevant global print settings as
1901      set by "set print" subcommands:
1902 
1903       -address [on|off]
1904       -array [on|off]
1905       -array-indexes [on|off]
1906       -elements NUMBER|unlimited
1907       -null-stop [on|off]
1908       -object [on|off]
1909       -pretty [on|off]
1910       -raw-values [on|off]
1911       -repeats NUMBER|unlimited
1912       -static-members [on|off]
1913       -symbol [on|off]
1914       -union [on|off]
1915       -vtbl [on|off]
1916 
1917      Note that because the "print"/"compile print" commands accept
1918      arbitrary expressions which may look like options (including
1919      abbreviations), if you specify any command option, then you must
1920      use a double dash ("--") to mark the end of argument processing.
1921 
1922   ** The "backtrace" command now supports a number of options that
1923      allow overriding relevant global print settings as set by "set
1924      backtrace" and "set print" subcommands:
1925 
1926       -entry-values no|only|preferred|if-needed|both|compact|default
1927       -frame-arguments all|scalars|none
1928       -raw-frame-arguments [on|off]
1929       -frame-info auto|source-line|location|source-and-location
1930            |location-and-address|short-location
1931       -past-main [on|off]
1932       -past-entry [on|off]
1933 
1934      In addition, the full/no-filters/hide qualifiers are now also
1935      exposed as command options too:
1936 
1937       -full
1938       -no-filters
1939       -hide
1940 
1941   ** The "frame apply", "tfaas" and "faas" commands similarly now
1942      support the following options:
1943 
1944       -past-main [on|off]
1945       -past-entry [on|off]
1946 
1947   ** The new "info sources" options -dirname and -basename options
1948      are using the standard '-OPT' infrastructure.
1949 
1950    All options above can also be abbreviated.  The argument of boolean
1951    (on/off) options can be 0/1 too, and also the argument is assumed
1952    "on" if omitted.  This allows writing compact command invocations,
1953    like for example:
1954 
1955     (gdb) p -ra -p -o 0 -- *myptr
1956 
1957    The above is equivalent to:
1958 
1959     (gdb) print -raw-values -pretty -object off -- *myptr
1960 
1961   ** The "info types" command now supports the '-q' flag to disable
1962      printing of some header information in a similar fashion to "info
1963      variables" and "info functions".
1964 
1965   ** The "info variables", "info functions", and "whereis" commands
1966      now take a '-n' flag that excludes non-debug symbols (symbols
1967      from the symbol table, not from the debug info such as DWARF)
1968      from the results.
1969 
1970 * Completion improvements
1971 
1972   ** GDB can now complete the options of the "thread apply all" and
1973      "taas" commands, and their "-ascending" option can now be
1974      abbreviated.
1975 
1976   ** GDB can now complete the options of the "info threads", "info
1977      functions", "info variables", "info locals", and "info args"
1978      commands.
1979 
1980   ** GDB can now complete the options of the "compile file" and
1981      "compile code" commands.  The "compile file" command now
1982      completes on filenames.
1983 
1984   ** GDB can now complete the backtrace command's
1985      "full/no-filters/hide" qualifiers.
1986 
1987 * In settings, you can now abbreviate "unlimited".
1988 
1989   E.g., "set print elements u" is now equivalent to "set print
1990   elements unlimited".
1991 
1992 * New MI commands
1993 
1994 -complete
1995   This lists all the possible completions for the rest of the line, if it
1996   were to be given as a command itself.  This is intended for use by MI
1997   frontends in cases when separate CLI and MI channels cannot be used.
1998 
1999 -catch-throw, -catch-rethrow, and -catch-catch
2000   These can be used to catch C++ exceptions in a similar fashion to
2001   the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
2002 
2003 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
2004   These commands are the MI equivalent of the CLI commands 'info
2005   functions', 'info types', and 'info variables' respectively.
2006 
2007 -symbol-info-modules, this is the MI equivalent of the CLI 'info
2008   modules' command.
2009 
2010 -symbol-info-module-functions and -symbol-info-module-variables.
2011   These commands are the MI equivalent of the CLI commands 'info
2012   module functions' and 'info module variables'.
2013 
2014 * Other MI changes
2015 
2016  ** The default version of the MI interpreter is now 3 (-i=mi3).
2017 
2018   ** The output of information about multi-location breakpoints (which is
2019      syntactically incorrect in MI 2) has changed in MI 3.  This affects
2020      the following commands and events:
2021 
2022         - -break-insert
2023         - -break-info
2024         - =breakpoint-created
2025         - =breakpoint-modified
2026 
2027      The -fix-multi-location-breakpoint-output command can be used to enable
2028      this behavior with previous MI versions.
2029 
2030  ** Backtraces and frames include a new optional field addr_flags which is
2031     given after the addr field.  On AArch64 this contains PAC if the address
2032     has been masked in the frame.  On all other targets the field is not
2033     present.
2034 
2035 * Testsuite
2036 
2037   The testsuite now creates the files gdb.cmd (containing the arguments
2038   used to launch GDB) and gdb.in (containing all the commands sent to
2039   GDB) in the output directory for each test script.  Multiple invocations
2040   are appended with .1, .2, .3 etc.
2041 
2042 * Building GDB and GDBserver now requires GNU make >= 3.82.
2043 
2044   Using another implementation of the make program or an earlier version of
2045   GNU make to build GDB or GDBserver is not supported.
2046 
2047 * Building GDB now requires GNU readline >= 7.0.
2048 
2049   GDB now bundles GNU readline 8.0, but if you choose to use
2050   --with-system-readline, only readline >= 7.0 can be used.
2051 
2052 * The TUI SingleKey keymap is now named "SingleKey".  This can be used
2053   from .inputrc to bind keys in this keymap.  This feature is only
2054   available when gdb is built against GNU readline 8.0 or later.
2055 
2056 * Removed targets and native configurations
2057 
2058   GDB no longer supports debugging the Cell Broadband Engine.  This includes
2059   both debugging standalone Cell/B.E. SPU applications and integrated debugging
2060   of Cell/B.E. applications that use both the PPU and SPU architectures.
2061 
2062 * New Simulators
2063 
2064 TI PRU                                  pru-*-elf
2065 
2066 * Removed targets and native configurations
2067 
2068 Solaris 10                      i?86-*-solaris2.10, x86_64-*-solaris2.10,
2069                                 sparc*-*-solaris2.10
2070 
2071 *** Changes in GDB 8.3
2072 
2073 * GDB and GDBserver now support access to additional registers on
2074   PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
2075   HTM registers.
2076 
2077 * GDB now has experimental support for the compilation and injection of
2078   C++ source code into the inferior.  This beta release does not include
2079   support for several language features, such as templates, constructors,
2080   and operators.
2081 
2082   This feature requires GCC 7.1 or higher built with libcp1.so
2083   (the C++ plug-in).
2084 
2085 * GDB and GDBserver now support IPv6 connections.  IPv6 addresses
2086   can be passed using the '[ADDRESS]:PORT' notation, or the regular
2087   'ADDRESS:PORT' method.
2088 
2089 * DWARF index cache: GDB can now automatically save indices of DWARF
2090   symbols on disk to speed up further loading of the same binaries.
2091 
2092 * Ada task switching is now supported on aarch64-elf targets when
2093   debugging a program using the Ravenscar Profile.  For more information,
2094   see the "Tasking Support when using the Ravenscar Profile" section
2095   in the GDB user manual.
2096 
2097 * GDB in batch mode now exits with status 1 if the last command to be
2098   executed failed.
2099 
2100 * The RISC-V target now supports target descriptions.
2101 
2102 * System call catchpoints now support system call aliases on FreeBSD.
2103   When the ABI of a system call changes in FreeBSD, this is
2104   implemented by leaving a compatibility system call using the old ABI
2105   at the existing number and allocating a new system call number for
2106   the new ABI.  For example, FreeBSD 12 altered the layout of 'struct
2107   kevent' used by the 'kevent' system call.  As a result, FreeBSD 12
2108   kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
2109   The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
2110   so that a system call catchpoint for the 'kevent' system call will
2111   catch invocations of both the 'kevent' and 'freebsd11_kevent'
2112   binaries.  This ensures that 'kevent' system calls are caught for
2113   binaries using either the old or new ABIs.
2114 
2115 * Terminal styling is now available for the CLI and the TUI.  GNU
2116   Source Highlight can additionally be used to provide styling of
2117   source code snippets.  See the "set style" commands, below, for more
2118   information.
2119 
2120 * Removed support for old demangling styles arm, edg, gnu, hp and
2121   lucid.
2122 
2123 * New commands
2124 
2125 set debug compile-cplus-types
2126 show debug compile-cplus-types
2127   Control the display of debug output about type conversion in the
2128   C++ compile feature.  Commands have no effect while compiling
2129   for other languages.
2130 
2131 set debug skip
2132 show debug skip
2133   Control whether debug output about files/functions skipping is
2134   displayed.
2135 
2136 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2137   Apply a command to some frames.
2138   FLAG arguments allow to control what output to produce and how to handle
2139   errors raised when applying COMMAND to a frame.
2140 
2141 taas COMMAND
2142   Apply a command to all threads (ignoring errors and empty output).
2143   Shortcut for 'thread apply all -s COMMAND'.
2144 
2145 faas COMMAND
2146   Apply a command to all frames (ignoring errors and empty output).
2147   Shortcut for 'frame apply all -s COMMAND'.
2148 
2149 tfaas COMMAND
2150   Apply a command to all frames of all threads (ignoring errors and empty
2151   output).
2152   Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2153 
2154 maint set dwarf unwinders (on|off)
2155 maint show dwarf unwinders
2156   Control whether DWARF unwinders can be used.
2157 
2158 info proc files
2159   Display a list of open files for a process.
2160 
2161 * Changed commands
2162 
2163 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2164   These commands all now take a frame specification which
2165   is either a frame level, or one of the keywords 'level', 'address',
2166   'function', or 'view' followed by a parameter.  Selecting a frame by
2167   address, or viewing a frame outside the current backtrace now
2168   requires the use of a keyword.  Selecting a frame by level is
2169   unchanged.  The MI comment "-stack-select-frame" is unchanged.
2170 
2171 target remote FILENAME
2172 target extended-remote FILENAME
2173   If FILENAME is a Unix domain socket, GDB will attempt to connect
2174   to this socket instead of opening FILENAME as a character device.
2175 
2176 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2177 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2178 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2179 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2180   These commands can now print only the searched entities
2181   matching the provided regexp(s), giving a condition
2182   on the entity names or entity types.  The flag -q disables
2183   printing headers or informations messages.
2184 
2185 info functions
2186 info types
2187 info variables
2188 rbreak
2189   These commands now determine the syntax for the shown entities
2190   according to the language chosen by `set language'.  In particular,
2191   `set language auto' means to automatically choose the language of
2192   the shown entities.
2193 
2194 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2195   The 'thread apply' command accepts new FLAG arguments.
2196   FLAG arguments allow to control what output to produce and how to handle
2197   errors raised when applying COMMAND to a thread.
2198 
2199 set tui tab-width NCHARS
2200 show tui tab-width NCHARS
2201   "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2202 
2203 set style enabled [on|off]
2204 show style enabled
2205   Enable or disable terminal styling.  Styling is enabled by default
2206   on most hosts, but disabled by default when in batch mode.
2207 
2208 set style sources [on|off]
2209 show style sources
2210   Enable or disable source code styling.  Source code styling is
2211   enabled by default, but only takes effect if styling in general is
2212   enabled, and if GDB was linked with GNU Source Highlight.
2213 
2214 set style filename foreground COLOR
2215 set style filename background COLOR
2216 set style filename intensity VALUE
2217   Control the styling of file names.
2218 
2219 set style function foreground COLOR
2220 set style function background COLOR
2221 set style function intensity VALUE
2222   Control the styling of function names.
2223 
2224 set style variable foreground COLOR
2225 set style variable background COLOR
2226 set style variable intensity VALUE
2227   Control the styling of variable names.
2228 
2229 set style address foreground COLOR
2230 set style address background COLOR
2231 set style address intensity VALUE
2232   Control the styling of addresses.
2233 
2234 * MI changes
2235 
2236   ** The '-data-disassemble' MI command now accepts an '-a' option to
2237      disassemble the whole function surrounding the given program
2238      counter value or function name.  Support for this feature can be
2239      verified by using the "-list-features" command, which should
2240      contain "data-disassemble-a-option".
2241 
2242   ** Command responses and notifications that include a frame now include
2243      the frame's architecture in a new "arch" attribute.
2244 
2245 * New native configurations
2246 
2247 GNU/Linux/RISC-V                riscv*-*-linux*
2248 FreeBSD/riscv                   riscv*-*-freebsd*
2249 
2250 * New targets
2251 
2252 GNU/Linux/RISC-V                riscv*-*-linux*
2253 CSKY ELF                        csky*-*-elf
2254 CSKY GNU/LINUX                  csky*-*-linux
2255 FreeBSD/riscv                   riscv*-*-freebsd*
2256 NXP S12Z                        s12z-*-elf
2257 GNU/Linux/OpenRISC              or1k*-*-linux*
2258 
2259 * Removed targets
2260 
2261 GDB no longer supports native debugging on versions of MS-Windows
2262 before Windows XP.
2263 
2264 * Python API
2265 
2266   ** GDB no longer supports Python versions less than 2.6.
2267 
2268   ** The gdb.Inferior type has a new 'progspace' property, which is the program
2269      space associated to that inferior.
2270 
2271   ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2272      of objfiles associated to that program space.
2273 
2274   ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2275      gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2276      the gdb core.
2277 
2278   ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2279      gdb.SYMBOL_TYPES_DOMAIN are now deprecated.  These were never
2280      correct and did not work properly.
2281 
2282   ** The gdb.Value type has a new constructor, which is used to construct a
2283      gdb.Value from a Python buffer object and a gdb.Type.
2284 
2285 * Configure changes
2286 
2287 --enable-ubsan
2288 
2289   Enable or disable the undefined behavior sanitizer.  This is
2290   disabled by default, but passing --enable-ubsan=yes or
2291   --enable-ubsan=auto to configure will enable it.  Enabling this can
2292   cause a performance penalty.  The undefined behavior sanitizer was
2293   first introduced in GCC 4.9.
2294 
2295 *** Changes in GDB 8.2
2296 
2297 * The 'set disassembler-options' command now supports specifying options
2298   for the MIPS target.
2299 
2300 * The 'symbol-file' command now accepts an '-o' option to add a relative
2301   offset to all sections.
2302 
2303 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2304   a relative offset to all sections, but it allows to override the load
2305   address of individual sections using '-s'.
2306 
2307 * The 'add-symbol-file' command no longer requires the second argument
2308   (address of the text section).
2309 
2310 * The endianness used with the 'set endian auto' mode in the absence of
2311   an executable selected for debugging is now the last endianness chosen
2312   either by one of the 'set endian big' and 'set endian little' commands
2313   or by inferring from the last executable used, rather than the startup
2314   default.
2315 
2316 * The pager now allows a "c" response, meaning to disable the pager
2317   for the rest of the current command.
2318 
2319 * The commands 'info variables/functions/types' now show the source line
2320   numbers of symbol definitions when available.
2321 
2322 * 'info proc' now works on running processes on FreeBSD systems and core
2323   files created on FreeBSD systems.
2324 
2325 * C expressions can now use _Alignof, and C++ expressions can now use
2326   alignof.
2327 
2328 * Support for SVE on AArch64 Linux.  Note that GDB does not detect changes to
2329   the vector length while the process is running.
2330 
2331 * New commands
2332 
2333 set debug fbsd-nat
2334 show debug fbsd-nat
2335   Control display of debugging info regarding the FreeBSD native target.
2336 
2337 set|show varsize-limit
2338   This new setting allows the user to control the maximum size of Ada
2339   objects being printed when those objects have a variable type,
2340   instead of that maximum size being hardcoded to 65536 bytes.
2341 
2342 set|show record btrace cpu
2343   Controls the processor to be used for enabling errata workarounds for
2344   branch trace decode.
2345 
2346 maint check libthread-db
2347   Run integrity checks on the current inferior's thread debugging
2348   library
2349 
2350 maint set check-libthread-db (on|off)
2351 maint show check-libthread-db
2352   Control whether to run integrity checks on inferior specific thread
2353   debugging libraries as they are loaded.  The default is not to
2354   perform such checks.
2355 
2356 * Python API
2357 
2358   ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2359 
2360   ** The commands attached to a breakpoint can be set by assigning to
2361      the breakpoint's "commands" field.
2362 
2363   ** gdb.execute can now execute multi-line gdb commands.
2364 
2365   ** The new functions gdb.convenience_variable and
2366      gdb.set_convenience_variable can be used to get and set the value
2367      of convenience variables.
2368 
2369   ** A gdb.Parameter will no longer print the "set" help text on an
2370      ordinary "set"; instead by default a "set" will be silent unless
2371      the get_set_string method returns a non-empty string.
2372 
2373 * New targets
2374 
2375 RiscV ELF                       riscv*-*-elf
2376 
2377 * Removed targets and native configurations
2378 
2379 m88k running OpenBSD            m88*-*-openbsd*
2380 SH-5/SH64 ELF                   sh64-*-elf*, SH-5/SH64 support in sh*
2381 SH-5/SH64 running GNU/Linux     SH-5/SH64 support in sh*-*-linux*
2382 SH-5/SH64 running OpenBSD       SH-5/SH64 support in sh*-*-openbsd*
2383 
2384 * Aarch64/Linux hardware watchpoints improvements
2385 
2386   Hardware watchpoints on unaligned addresses are now properly
2387   supported when running Linux kernel 4.10 or higher: read and access
2388   watchpoints are no longer spuriously missed, and all watchpoints
2389   lengths between 1 and 8 bytes are supported.  On older kernels,
2390   watchpoints set on unaligned addresses are no longer missed, with
2391   the tradeoff that there is a possibility of false hits being
2392   reported.
2393 
2394 * Configure changes
2395 
2396 --enable-codesign=CERT
2397   This can be used to invoke "codesign -s CERT" after building gdb.
2398   This option is useful on macOS, where code signing is required for
2399   gdb to work properly.
2400 
2401 --disable-gdbcli has been removed
2402   This is now silently accepted, but does nothing.
2403 
2404 *** Changes in GDB 8.1
2405 
2406 * GDB now supports dynamically creating arbitrary register groups specified
2407   in XML target descriptions.  This allows for finer grain grouping of
2408   registers on systems with a large amount of registers.
2409 
2410 * The 'ptype' command now accepts a '/o' flag, which prints the
2411   offsets and sizes of fields in a struct, like the pahole(1) tool.
2412 
2413 * New "--readnever" command line option instructs GDB to not read each
2414   symbol file's symbolic debug information.  This makes startup faster
2415   but at the expense of not being able to perform symbolic debugging.
2416   This option is intended for use cases where symbolic debugging will
2417   not be used, e.g., when you only need to dump the debuggee's core.
2418 
2419 * GDB now uses the GNU MPFR library, if available, to emulate target
2420   floating-point arithmetic during expression evaluation when the target
2421   uses different floating-point formats than the host.  At least version
2422   3.1 of GNU MPFR is required.
2423 
2424 * GDB now supports access to the guarded-storage-control registers and the
2425   software-based guarded-storage broadcast control registers on IBM z14.
2426 
2427 * On Unix systems, GDB now supports transmitting environment variables
2428   that are to be set or unset to GDBserver.  These variables will
2429   affect the environment to be passed to the remote inferior.
2430 
2431   To inform GDB of environment variables that are to be transmitted to
2432   GDBserver, use the "set environment" command.  Only user set
2433   environment variables are sent to GDBserver.
2434 
2435   To inform GDB of environment variables that are to be unset before
2436   the remote inferior is started by the GDBserver, use the "unset
2437   environment" command.
2438 
2439 * Completion improvements
2440 
2441   ** GDB can now complete function parameters in linespecs and
2442      explicit locations without quoting.  When setting breakpoints,
2443      quoting around functions names to help with TAB-completion is
2444      generally no longer necessary.  For example, this now completes
2445      correctly:
2446 
2447       (gdb) b function(in[TAB]
2448       (gdb) b function(int)
2449 
2450      Related, GDB is no longer confused with completing functions in
2451      C++ anonymous namespaces:
2452 
2453       (gdb) b (anon[TAB]
2454       (gdb) b (anonymous namespace)::[TAB][TAB]
2455       (anonymous namespace)::a_function()
2456       (anonymous namespace)::b_function()
2457 
2458   ** GDB now has much improved linespec and explicit locations TAB
2459      completion support, that better understands what you're
2460      completing and offers better suggestions.  For example, GDB no
2461      longer offers data symbols as possible completions when you're
2462      setting a breakpoint.
2463 
2464   ** GDB now TAB-completes label symbol names.
2465 
2466   ** The "complete" command now mimics TAB completion accurately.
2467 
2468 * New command line options (gcore)
2469 
2470 -a
2471   Dump all memory mappings.
2472 
2473 * Breakpoints on C++ functions are now set on all scopes by default
2474 
2475   By default, breakpoints on functions/methods are now interpreted as
2476   specifying all functions with the given name ignoring missing
2477   leading scopes (namespaces and classes).
2478 
2479   For example, assuming a C++ program with symbols named:
2480 
2481     A::B::func()
2482     B::func()
2483 
2484   both commands "break func()" and "break B::func()" set a breakpoint
2485   on both symbols.
2486 
2487   You can use the new flag "-qualified" to override this.  This makes
2488   GDB interpret the specified function name as a complete
2489   fully-qualified name instead.  For example, using the same C++
2490   program, the "break -q B::func" command sets a breakpoint on
2491   "B::func", only.  A parameter has been added to the Python
2492   gdb.Breakpoint constructor to achieve the same result when creating
2493   a breakpoint from Python.
2494 
2495 * Breakpoints on functions marked with C++ ABI tags
2496 
2497   GDB can now set breakpoints on functions marked with C++ ABI tags
2498   (e.g., [abi:cxx11]).  See here for a description of ABI tags:
2499   https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2500 
2501   Functions with a C++11 abi tag are demangled/displayed like this:
2502 
2503     function[abi:cxx11](int)
2504             ^^^^^^^^^^^
2505 
2506   You can now set a breakpoint on such functions simply as if they had
2507   no tag, like:
2508 
2509     (gdb) b function(int)
2510 
2511   Or if you need to disambiguate between tags, like:
2512 
2513     (gdb) b function[abi:other_tag](int)
2514 
2515   Tab completion was adjusted accordingly as well.
2516 
2517 * Python Scripting
2518 
2519   ** New events gdb.new_inferior, gdb.inferior_deleted, and
2520      gdb.new_thread are emitted.  See the manual for further
2521      description of these.
2522 
2523   ** A new function, "gdb.rbreak" has been added to the Python API.
2524      This function allows the setting of a large number of breakpoints
2525      via a regex pattern in Python.  See the manual for further details.
2526 
2527   ** Python breakpoints can now accept explicit locations.  See the
2528      manual for a further description of this feature.
2529 
2530 
2531 * New features in the GDB remote stub, GDBserver
2532 
2533   ** GDBserver is now able to start inferior processes with a
2534      specified initial working directory.
2535 
2536      The user can set the desired working directory to be used from
2537      GDB using the new "set cwd" command.
2538 
2539   ** New "--selftest" command line option runs some GDBserver self
2540      tests.  These self tests are disabled in releases.
2541 
2542   ** On Unix systems, GDBserver now does globbing expansion and variable
2543      substitution in inferior command line arguments.
2544 
2545      This is done by starting inferiors using a shell, like GDB does.
2546      See "set startup-with-shell" in the user manual for how to disable
2547      this from GDB when using "target extended-remote".  When using
2548      "target remote", you can disable the startup with shell by using the
2549      new "--no-startup-with-shell" GDBserver command line option.
2550 
2551   ** On Unix systems, GDBserver now supports receiving environment
2552      variables that are to be set or unset from GDB.  These variables
2553      will affect the environment to be passed to the inferior.
2554 
2555 * When catching an Ada exception raised with a message, GDB now prints
2556   the message in the catchpoint hit notification. In GDB/MI mode, that
2557   information is provided as an extra field named "exception-message"
2558   in the *stopped notification.
2559 
2560 * Trait objects can now be inspected When debugging Rust code.  This
2561   requires compiler support which will appear in Rust 1.24.
2562 
2563 * New remote packets
2564 
2565 QEnvironmentHexEncoded
2566   Inform GDBserver of an environment variable that is to be passed to
2567   the inferior when starting it.
2568 
2569 QEnvironmentUnset
2570   Inform GDBserver of an environment variable that is to be unset
2571   before starting the remote inferior.
2572 
2573 QEnvironmentReset
2574   Inform GDBserver that the environment should be reset (i.e.,
2575   user-set environment variables should be unset).
2576 
2577 QStartupWithShell
2578   Indicates whether the inferior must be started with a shell or not.
2579 
2580 QSetWorkingDir
2581   Tell GDBserver that the inferior to be started should use a specific
2582   working directory.
2583 
2584 * The "maintenance print c-tdesc" command now takes an optional
2585   argument which is the file name of XML target description.
2586 
2587 * The "maintenance selftest" command now takes an optional argument to
2588   filter the tests to be run.
2589 
2590 * The "enable", and "disable" commands now accept a range of
2591   breakpoint locations, e.g. "enable 1.3-5".
2592 
2593 * New commands
2594 
2595 set|show cwd
2596   Set and show the current working directory for the inferior.
2597 
2598 set|show compile-gcc
2599   Set and show compilation command used for compiling and injecting code
2600   with the 'compile' commands.
2601 
2602 set debug separate-debug-file
2603 show debug separate-debug-file
2604   Control the display of debug output about separate debug file search.
2605 
2606 set dump-excluded-mappings
2607 show dump-excluded-mappings
2608   Control whether mappings marked with the VM_DONTDUMP flag should be
2609   dumped when generating a core file.
2610 
2611 maint info selftests
2612   List the registered selftests.
2613 
2614 starti
2615   Start the debugged program stopping at the first instruction.
2616 
2617 set|show debug or1k
2618   Control display of debugging messages related to OpenRISC targets.
2619 
2620 set|show print type nested-type-limit
2621   Set and show the limit of nesting level for nested types that the
2622   type printer will show.
2623 
2624 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2625   `o' for nexti.
2626 
2627 * Safer/improved support for debugging with no debug info
2628 
2629   GDB no longer assumes functions with no debug information return
2630   'int'.
2631 
2632   This means that GDB now refuses to call such functions unless you
2633   tell it the function's type, by either casting the call to the
2634   declared return type, or by casting the function to a function
2635   pointer of the right type, and calling that:
2636 
2637     (gdb) p getenv ("PATH")
2638     'getenv' has unknown return type; cast the call to its declared return type
2639     (gdb) p (char *) getenv ("PATH")
2640     $1 = 0x7fffffffe "/usr/local/bin:/"...
2641     (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2642     $2 = 0x7fffffffe "/usr/local/bin:/"...
2643 
2644   Similarly, GDB no longer assumes that global variables with no debug
2645   info have type 'int', and refuses to print the variable's value
2646   unless you tell it the variable's type:
2647 
2648     (gdb) p var
2649     'var' has unknown type; cast it to its declared type
2650     (gdb) p (float) var
2651     $3 = 3.14
2652 
2653 * New native configurations
2654 
2655 FreeBSD/aarch64                 aarch64*-*-freebsd*
2656 FreeBSD/arm                     arm*-*-freebsd*
2657 
2658 * New targets
2659 
2660 FreeBSD/aarch64                 aarch64*-*-freebsd*
2661 FreeBSD/arm                     arm*-*-freebsd*
2662 OpenRISC ELF                    or1k*-*-elf
2663 
2664 * Removed targets and native configurations
2665 
2666 Solaris 2.0-9                   i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2667 
2668 *** Changes in GDB 8.0
2669 
2670 * GDB now supports access to the PKU register on GNU/Linux. The register is
2671   added by the Memory Protection Keys for Userspace feature which will be
2672   available in future Intel CPUs.
2673 
2674 * GDB now supports C++11 rvalue references.
2675 
2676 * Python Scripting
2677 
2678   ** New functions to start, stop and access a running btrace recording.
2679   ** Rvalue references are now supported in gdb.Type.
2680 
2681 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2682   instructions.
2683 
2684 * Building GDB and GDBserver now requires a C++11 compiler.
2685 
2686   For example, GCC 4.8 or later.
2687 
2688   It is no longer possible to build GDB or GDBserver with a C
2689   compiler.  The --disable-build-with-cxx configure option has been
2690   removed.
2691 
2692 * Building GDB and GDBserver now requires GNU make >= 3.81.
2693 
2694   It is no longer supported to build GDB or GDBserver with another
2695   implementation of the make program or an earlier version of GNU make.
2696 
2697 * Native debugging on MS-Windows supports command-line redirection
2698 
2699   Command-line arguments used for starting programs on MS-Windows can
2700   now include redirection symbols supported by native Windows shells,
2701   such as '<', '>', '>>', '2>&1', etc.  This affects GDB commands such
2702   as "run", "start", and "set args", as well as the corresponding MI
2703   features.
2704 
2705 * Support for thread names on MS-Windows.
2706 
2707   GDB now catches and handles the special exception that programs
2708   running on MS-Windows use to assign names to threads in the
2709   debugger.
2710 
2711 * Support for Java programs compiled with gcj has been removed.
2712 
2713 * User commands now accept an unlimited number of arguments.
2714   Previously, only up to 10 was accepted.
2715 
2716 * The "eval" command now expands user-defined command arguments.
2717 
2718   This makes it easier to process a variable number of arguments:
2719 
2720    define mycommand
2721      set $i = 0
2722      while $i < $argc
2723        eval "print $arg%d", $i
2724        set $i = $i + 1
2725      end
2726    end
2727 
2728 * Target descriptions can now describe registers for sparc32 and sparc64.
2729 
2730 * GDB now supports DWARF version 5 (debug information format).
2731   Its .debug_names index is not yet supported.
2732 
2733 * New native configurations
2734 
2735 FreeBSD/mips                    mips*-*-freebsd
2736 
2737 * New targets
2738 
2739 Synopsys ARC                    arc*-*-elf32
2740 FreeBSD/mips                    mips*-*-freebsd
2741 
2742 * Removed targets and native configurations
2743 
2744 Alpha running FreeBSD         alpha*-*-freebsd*
2745 Alpha running GNU/kFreeBSD    alpha*-*-kfreebsd*-gnu
2746 
2747 * New commands
2748 
2749 flash-erase
2750   Erases all the flash memory regions reported by the target.
2751 
2752 maint print arc arc-instruction address
2753   Print internal disassembler information about instruction at a given address.
2754 
2755 * New options
2756 
2757 set disassembler-options
2758 show disassembler-options
2759   Controls the passing of target specific information to the disassembler.
2760   If it is necessary to specify more than one disassembler option then
2761   multiple options can be placed together into a comma separated list.
2762   The default value is the empty string.  Currently, the only supported
2763   targets are ARM, PowerPC and S/390.
2764 
2765 * New MI commands
2766 
2767 -target-flash-erase
2768   Erases all the flash memory regions reported by the target.  This is
2769   equivalent to the CLI command flash-erase.
2770 
2771 -file-list-shared-libraries
2772   List the shared libraries in the program.  This is
2773   equivalent to the CLI command "info shared".
2774 
2775 -catch-handlers
2776   Catchpoints stopping the program when Ada exceptions are
2777   handled.  This is equivalent to the CLI command "catch handlers".
2778 
2779 *** Changes in GDB 7.12
2780 
2781 * GDB and GDBserver now build with a C++ compiler by default.
2782 
2783   The --enable-build-with-cxx configure option is now enabled by
2784   default.  One must now explicitly configure with
2785   --disable-build-with-cxx in order to build with a C compiler.  This
2786   option will be removed in a future release.
2787 
2788 * GDBserver now supports recording btrace without maintaining an active
2789   GDB connection.
2790 
2791 * GDB now supports a negative repeat count in the 'x' command to examine
2792   memory backward from the given address.  For example:
2793 
2794     (gdb) bt
2795     #0  Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2796     #1  0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2797     (gdb) x/-5i 0x0000000000400580
2798        0x40056a <main(int, char**)+8>:      mov    %edi,-0x4(%rbp)
2799        0x40056d <main(int, char**)+11>:     mov    %rsi,-0x10(%rbp)
2800        0x400571 <main(int, char**)+15>:     mov    $0x40061c,%esi
2801        0x400576 <main(int, char**)+20>:     mov    $0x2a,%edi
2802        0x40057b <main(int, char**)+25>:
2803         callq  0x400536 <Func1(int, char const*)>
2804 
2805 * Fortran: Support structures with fields of dynamic types and 
2806   arrays of dynamic types.
2807 
2808 * The symbol dumping maintenance commands have new syntax.
2809 maint print symbols [-pc address] [--] [filename]
2810 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2811 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2812 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2813 maint print msymbols [-objfile objfile] [--] [filename]
2814 
2815 * GDB now supports multibit bitfields and enums in target register
2816   descriptions.
2817 
2818 * New Python-based convenience function $_as_string(val), which returns
2819   the textual representation of a value.  This function is especially
2820   useful to obtain the text label of an enum value.
2821 
2822 * Intel MPX bound violation handling.
2823 
2824    Segmentation faults caused by a Intel MPX boundary violation
2825    now display the kind of violation (upper or lower), the memory
2826    address accessed and the memory bounds, along with the usual
2827    signal received and code location.
2828 
2829    For example:
2830 
2831    Program received signal SIGSEGV, Segmentation fault
2832    Upper bound violation while accessing address 0x7fffffffc3b3
2833    Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2834    0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2835 
2836 * Rust language support.
2837   GDB now supports debugging programs written in the Rust programming
2838   language.  See https://www.rust-lang.org/ for more information about
2839   Rust.
2840 
2841 * Support for running interpreters on specified input/output devices
2842 
2843   GDB now supports a new mechanism that allows frontends to provide
2844   fully featured GDB console views, as a better alternative to
2845   building such views on top of the "-interpreter-exec console"
2846   command.  See the new "new-ui" command below.  With that command,
2847   frontends can now start GDB in the traditional command-line mode
2848   running in an embedded terminal emulator widget, and create a
2849   separate MI interpreter running on a specified i/o device.  In this
2850   way, GDB handles line editing, history, tab completion, etc. in the
2851   console all by itself, and the GUI uses the separate MI interpreter
2852   for its own control and synchronization, invisible to the command
2853   line.
2854 
2855 * The "catch syscall" command catches groups of related syscalls.
2856 
2857   The "catch syscall" command now supports catching a group of related
2858   syscalls using the 'group:' or 'g:' prefix.
2859 
2860 * New commands
2861 
2862 skip -file file
2863 skip -gfile file-glob-pattern
2864 skip -function function
2865 skip -rfunction regular-expression
2866   A generalized form of the skip command, with new support for
2867   glob-style file names and regular expressions for function names.
2868   Additionally, a file spec and a function spec may now be combined.
2869 
2870 maint info line-table REGEXP
2871   Display the contents of GDB's internal line table data structure.
2872 
2873 maint selftest
2874   Run any GDB unit tests that were compiled in.
2875 
2876 new-ui INTERP TTY
2877   Start a new user interface instance running INTERP as interpreter,
2878   using the TTY file for input/output.
2879 
2880 * Python Scripting
2881 
2882   ** gdb.Breakpoint objects have a new attribute "pending", which
2883      indicates whether the breakpoint is pending.
2884   ** Three new breakpoint-related events have been added:
2885      gdb.breakpoint_created, gdb.breakpoint_modified, and
2886      gdb.breakpoint_deleted.
2887 
2888 signal-event EVENTID
2889   Signal ("set") the given MS-Windows event object.  This is used in
2890   conjunction with the Windows JIT debugging (AeDebug) support, where
2891   the OS suspends a crashing process until a debugger can attach to
2892   it.  Resuming the crashing process, in order to debug it, is done by
2893   signalling an event.
2894 
2895 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2896   was added in GDBserver, including JIT compiling fast tracepoint's
2897   conditional expression bytecode into native code.
2898 
2899 * Support for various remote target protocols and ROM monitors has
2900   been removed:
2901 
2902   target m32rsdi        Remote M32R debugging over SDI
2903   target mips           MIPS remote debugging protocol
2904   target pmon           PMON ROM monitor
2905   target ddb            NEC's DDB variant of PMON for Vr4300
2906   target rockhopper     NEC RockHopper variant of PMON
2907   target lsi            LSI variant of PMO
2908 
2909 * Support for tracepoints and fast tracepoints on powerpc-linux,
2910   powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2911   including JIT compiling fast tracepoint's conditional expression
2912   bytecode into native code.
2913 
2914 * MI async record =record-started now includes the method and format used for
2915   recording.  For example:
2916 
2917     =record-started,thread-group="i1",method="btrace",format="bts"
2918 
2919 * MI async record =thread-selected now includes the frame field.  For example:
2920 
2921      =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2922 
2923 * New targets
2924 
2925 Andes NDS32                     nds32*-*-elf
2926 
2927 *** Changes in GDB 7.11
2928 
2929 * GDB now supports debugging kernel-based threads on FreeBSD.
2930 
2931 * Per-inferior thread numbers
2932 
2933   Thread numbers are now per inferior instead of global.  If you're
2934   debugging multiple inferiors, GDB displays thread IDs using a
2935   qualified INF_NUM.THR_NUM form.  For example:
2936 
2937      (gdb) info threads
2938        Id   Target Id         Frame
2939        1.1  Thread 0x7ffff7fc2740 (LWP 8155) (running)
2940        1.2  Thread 0x7ffff7fc1700 (LWP 8168) (running)
2941      * 2.1  Thread 0x7ffff7fc2740 (LWP 8157) (running)
2942        2.2  Thread 0x7ffff7fc1700 (LWP 8190) (running)
2943 
2944   As consequence, thread numbers as visible in the $_thread
2945   convenience variable and in Python's InferiorThread.num attribute
2946   are no longer unique between inferiors.
2947 
2948   GDB now maintains a second thread ID per thread, referred to as the
2949   global thread ID, which is the new equivalent of thread numbers in
2950   previous releases.  See also $_gthread below.
2951 
2952   For backwards compatibility, MI's thread IDs always refer to global
2953   IDs.
2954 
2955 * Commands that accept thread IDs now accept the qualified
2956   INF_NUM.THR_NUM form as well.  For example:
2957 
2958      (gdb) thread 2.1
2959      [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2960      (gdb)
2961 
2962 * In commands that accept a list of thread IDs, you can now refer to
2963   all threads of an inferior using a star wildcard.  GDB accepts
2964   "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2965   refer to all threads of the current inferior.  For example, "info
2966   threads 2.*".
2967 
2968 * You can use "info threads -gid" to display the global thread ID of
2969   all threads.
2970 
2971 * The new convenience variable $_gthread holds the global number of
2972   the current thread.
2973 
2974 * The new convenience variable $_inferior holds the number of the
2975   current inferior.
2976 
2977 * GDB now displays the ID and name of the thread that hit a breakpoint
2978   or received a signal, if your program is multi-threaded.  For
2979   example:
2980 
2981    Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2982    Thread 1 "main" received signal SIGINT, Interrupt.
2983 
2984 * Record btrace now supports non-stop mode.
2985 
2986 * Support for tracepoints on aarch64-linux was added in GDBserver.
2987 
2988 * The 'record instruction-history' command now indicates speculative execution
2989   when using the Intel Processor Trace recording format.
2990 
2991 * GDB now allows users to specify explicit locations, bypassing
2992   the linespec parser.  This feature is also available to GDB/MI
2993   clients.
2994 
2995 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2996   GDB now is able to debug both AArch64 applications and ARM applications
2997   at the same time.
2998 
2999 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
3000   including JIT compiling fast tracepoint's conditional expression bytecode
3001   into native code.
3002 
3003 * GDB now supports displaced stepping on AArch64 GNU/Linux.
3004 
3005 * "info threads", "info inferiors", "info display", "info checkpoints"
3006   and "maint info program-spaces" now list the corresponding items in
3007   ascending ID order, for consistency with all other "info" commands.
3008 
3009 * In Ada, the overloads selection menu has been enhanced to display the
3010   parameter types and the return types for the matching overloaded subprograms.
3011 
3012 * New commands
3013 
3014 maint set target-non-stop (on|off|auto)
3015 maint show target-non-stop
3016   Control whether GDB targets always operate in non-stop mode even if
3017   "set non-stop" is "off".  The default is "auto", meaning non-stop
3018   mode is enabled if supported by the target.
3019 
3020 maint set bfd-sharing
3021 maint show bfd-sharing
3022   Control the reuse of bfd objects.
3023 
3024 set debug bfd-cache
3025 show debug bfd-cache
3026   Control display of debugging info regarding bfd caching.
3027 
3028 set debug fbsd-lwp
3029 show debug fbsd-lwp
3030   Control display of debugging info regarding FreeBSD threads.
3031 
3032 set remote multiprocess-extensions-packet
3033 show remote multiprocess-extensions-packet
3034   Set/show the use of the remote protocol multiprocess extensions.
3035 
3036 set remote thread-events
3037 show remote thread-events
3038   Set/show the use of thread create/exit events.
3039 
3040 set ada print-signatures on|off
3041 show ada print-signatures"
3042   Control whether parameter types and return types are displayed in overloads
3043   selection menus.  It is activated (@code{on}) by default.
3044 
3045 set max-value-size
3046 show max-value-size
3047   Controls the maximum size of memory, in bytes, that GDB will
3048   allocate for value contents.  Prevents incorrect programs from
3049   causing GDB to allocate overly large buffers.  Default is 64k.
3050 
3051 * The "disassemble" command accepts a new modifier: /s.
3052   It prints mixed source+disassembly like /m with two differences:
3053   - disassembled instructions are now printed in program order, and
3054   - and source for all relevant files is now printed.
3055   The "/m" option is now considered deprecated: its "source-centric"
3056   output hasn't proved useful in practice.
3057 
3058 * The "record instruction-history" command accepts a new modifier: /s.
3059   It behaves exactly like /m and prints mixed source+disassembly.
3060 
3061 * The "set scheduler-locking" command supports a new mode "replay".
3062   It behaves like "off" in record mode and like "on" in replay mode.
3063 
3064 * Support for various ROM monitors has been removed:
3065 
3066   target dbug           dBUG ROM monitor for Motorola ColdFire
3067   target picobug        Motorola picobug monitor
3068   target dink32         DINK32 ROM monitor for PowerPC
3069   target m32r           Renesas M32R/D ROM monitor
3070   target mon2000        mon2000 ROM monitor
3071   target ppcbug         PPCBUG ROM monitor for PowerPC
3072 
3073 * Support for reading/writing memory and extracting values on architectures
3074   whose memory is addressable in units of any integral multiple of 8 bits.
3075 
3076 catch handlers
3077   Allows to break when an Ada exception is handled.
3078 
3079 * New remote packets
3080 
3081 exec stop reason
3082   Indicates that an exec system call was executed.
3083 
3084 exec-events feature in qSupported
3085   The qSupported packet allows GDB to request support for exec
3086   events using the new 'gdbfeature' exec-event, and the qSupported
3087   response can contain the corresponding 'stubfeature'.  Set and
3088   show commands can be used to display whether these features are enabled.
3089 
3090 vCtrlC
3091   Equivalent to interrupting with the ^C character, but works in
3092   non-stop mode.
3093 
3094 thread created stop reason (T05 create:...)
3095   Indicates that the thread was just created and is stopped at entry.
3096 
3097 thread exit stop reply (w exitcode;tid)
3098   Indicates that the thread has terminated.
3099 
3100 QThreadEvents
3101   Enables/disables thread create and exit event reporting.  For
3102   example, this is used in non-stop mode when GDB stops a set of
3103   threads and synchronously waits for the their corresponding stop
3104   replies.  Without exit events, if one of the threads exits, GDB
3105   would hang forever not knowing that it should no longer expect a
3106   stop for that same thread.
3107 
3108 N stop reply
3109   Indicates that there are no resumed threads left in the target (all
3110   threads are stopped).  The remote stub reports support for this stop
3111   reply to GDB's qSupported query.
3112 
3113 QCatchSyscalls
3114   Enables/disables catching syscalls from the inferior process.
3115   The remote stub reports support for this packet to GDB's qSupported query.
3116 
3117 syscall_entry stop reason
3118   Indicates that a syscall was just called.
3119 
3120 syscall_return stop reason
3121   Indicates that a syscall just returned.
3122 
3123 * Extended-remote exec events
3124 
3125   ** GDB now has support for exec events on extended-remote Linux targets.
3126      For such targets with Linux kernels 2.5.46 and later, this enables
3127      follow-exec-mode and exec catchpoints.
3128 
3129 set remote exec-event-feature-packet
3130 show remote exec-event-feature-packet
3131   Set/show the use of the remote exec event feature.
3132 
3133  * Thread names in remote protocol
3134 
3135    The reply to qXfer:threads:read may now include a name attribute for each
3136    thread.
3137 
3138 * Target remote mode fork and exec events
3139 
3140   ** GDB now has support for fork and exec events on target remote mode
3141      Linux targets.  For such targets with Linux kernels 2.5.46 and later,
3142      this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3143      fork and exec catchpoints.
3144 
3145 * Remote syscall events
3146 
3147   ** GDB now has support for catch syscall on remote Linux targets,
3148      currently enabled on x86/x86_64 architectures.
3149 
3150 set remote catch-syscall-packet
3151 show remote catch-syscall-packet
3152   Set/show the use of the remote catch syscall feature.
3153 
3154 * MI changes
3155 
3156   ** The -var-set-format command now accepts the zero-hexadecimal
3157      format.  It outputs data in hexadecimal format with zero-padding on the
3158      left.
3159 
3160 * Python Scripting
3161 
3162   ** gdb.InferiorThread objects have a new attribute "global_num",
3163      which refers to the thread's global thread ID.  The existing
3164      "num" attribute now refers to the thread's per-inferior number.
3165      See "Per-inferior thread numbers" above.
3166   ** gdb.InferiorThread objects have a new attribute "inferior", which
3167      is the Inferior object the thread belongs to.
3168 
3169 *** Changes in GDB 7.10
3170 
3171 * Support for process record-replay and reverse debugging on aarch64*-linux*
3172   targets has been added.  GDB now supports recording of A64 instruction set
3173   including advance SIMD instructions.
3174 
3175 * Support for Sun's version of the "stabs" debug file format has been removed.
3176 
3177 * GDB now honors the content of the file /proc/PID/coredump_filter
3178   (PID is the process ID) on GNU/Linux systems.  This file can be used
3179   to specify the types of memory mappings that will be included in a
3180   corefile.  For more information, please refer to the manual page of
3181   "core(5)".  GDB also has a new command: "set use-coredump-filter
3182   on|off".  It allows to set whether GDB will read the content of the
3183   /proc/PID/coredump_filter file when generating a corefile.
3184 
3185 * The "info os" command on GNU/Linux can now display information on
3186   cpu information :
3187     "info os cpus" Listing of all cpus/cores on the system
3188 
3189 * GDB has two new commands: "set serial parity odd|even|none" and
3190   "show serial parity".  These allows to set or show parity for the
3191   remote serial I/O.
3192 
3193 * The "info source" command now displays the producer string if it was
3194   present in the debug info.  This typically includes the compiler version
3195   and may include things like its command line arguments.
3196 
3197 * The "info dll", an alias of the "info sharedlibrary" command,
3198   is now available on all platforms.
3199 
3200 * Directory names supplied to the "set sysroot" commands may be
3201   prefixed with "target:" to tell GDB to access shared libraries from
3202   the target system, be it local or remote.  This replaces the prefix
3203   "remote:".  The default sysroot has been changed from "" to
3204   "target:".  "remote:" is automatically converted to "target:" for
3205   backward compatibility.
3206 
3207 * The system root specified by "set sysroot" will be prepended to the
3208   filename of the main executable (if reported to GDB as absolute by
3209   the operating system) when starting processes remotely, and when
3210   attaching to already-running local or remote processes.
3211 
3212 * GDB now supports automatic location and retrieval of executable
3213   files from remote targets.  Remote debugging can now be initiated
3214   using only a "target remote" or "target extended-remote" command
3215   (no "set sysroot" or "file" commands are required).  See "New remote
3216   packets" below.
3217 
3218 * The "dump" command now supports verilog hex format.
3219 
3220 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3221 
3222 * On GNU/Linux, GDB and gdbserver are now able to access executable
3223   and shared library files without a "set sysroot" command when
3224   attaching to processes running in different mount namespaces from
3225   the debugger.  This makes it possible to attach to processes in
3226   containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3227   See "New remote packets" below.
3228 
3229 * The "tui reg" command now provides completion for all of the
3230   available register groups, including target specific groups.
3231 
3232 * The HISTSIZE environment variable is no longer read when determining
3233   the size of GDB's command history.  GDB now instead reads the dedicated
3234   GDBHISTSIZE environment variable.  Setting GDBHISTSIZE to "-1" or to "" now
3235   disables truncation of command history.  Non-numeric values of GDBHISTSIZE
3236   are ignored.
3237 
3238 * Guile Scripting
3239 
3240   ** Memory ports can now be unbuffered.
3241 
3242 * Python Scripting
3243 
3244   ** gdb.Objfile objects have a new attribute "username",
3245      which is the name of the objfile as specified by the user,
3246      without, for example, resolving symlinks.
3247   ** You can now write frame unwinders in Python.
3248   ** gdb.Type objects have a new method "optimized_out",
3249      returning optimized out gdb.Value instance of this type.
3250   ** gdb.Value objects have new methods "reference_value" and
3251      "const_value" which return a reference to the value and a
3252      "const" version of the value respectively.
3253 
3254 * New commands
3255 
3256 maint print symbol-cache
3257   Print the contents of the symbol cache.
3258 
3259 maint print symbol-cache-statistics
3260   Print statistics of symbol cache usage.
3261 
3262 maint flush-symbol-cache
3263   Flush the contents of the symbol cache.
3264 
3265 record btrace bts
3266 record bts
3267   Start branch trace recording using Branch Trace Store (BTS) format.
3268 
3269 compile print
3270   Evaluate expression by using the compiler and print result.
3271 
3272 tui enable
3273 tui disable
3274   Explicit commands for enabling and disabling tui mode.
3275 
3276 show mpx bound
3277 set mpx bound on i386 and amd64
3278    Support for bound table investigation on Intel MPX enabled applications.
3279 
3280 record btrace pt
3281 record pt
3282   Start branch trace recording using Intel Processor Trace format.
3283 
3284 maint info btrace
3285   Print information about branch tracing internals.
3286 
3287 maint btrace packet-history
3288   Print the raw branch tracing data.
3289 
3290 maint btrace clear-packet-history
3291   Discard the stored raw branch tracing data.
3292 
3293 maint btrace clear
3294   Discard all branch tracing data.  It will be fetched and processed
3295   anew by the next "record" command.
3296 
3297 * New options
3298 
3299 set debug dwarf-die
3300   Renamed from "set debug dwarf2-die".
3301 show debug dwarf-die
3302   Renamed from "show debug dwarf2-die".
3303 
3304 set debug dwarf-read
3305   Renamed from "set debug dwarf2-read".
3306 show debug dwarf-read
3307   Renamed from "show debug dwarf2-read".
3308 
3309 maint set dwarf always-disassemble
3310   Renamed from "maint set dwarf2 always-disassemble".
3311 maint show dwarf always-disassemble
3312   Renamed from "maint show dwarf2 always-disassemble".
3313 
3314 maint set dwarf max-cache-age
3315   Renamed from "maint set dwarf2 max-cache-age".
3316 maint show dwarf max-cache-age
3317   Renamed from "maint show dwarf2 max-cache-age".
3318 
3319 set debug dwarf-line
3320 show debug dwarf-line
3321   Control display of debugging info regarding DWARF line processing.
3322 
3323 set max-completions
3324 show max-completions
3325   Set the maximum number of candidates to be considered during
3326   completion.  The default value is 200.  This limit allows GDB
3327   to avoid generating large completion lists, the computation of
3328   which can cause the debugger to become temporarily unresponsive.
3329 
3330 set history remove-duplicates
3331 show history remove-duplicates
3332   Control the removal of duplicate history entries.
3333 
3334 maint set symbol-cache-size
3335 maint show symbol-cache-size
3336   Control the size of the symbol cache.
3337 
3338 set|show record btrace bts buffer-size
3339   Set and show the size of the ring buffer used for branch tracing in
3340   BTS format.
3341   The obtained size may differ from the requested size.  Use "info
3342   record" to see the obtained buffer size.
3343 
3344 set debug linux-namespaces
3345 show debug linux-namespaces
3346   Control display of debugging info regarding Linux namespaces.
3347 
3348 set|show record btrace pt buffer-size
3349   Set and show the size of the ring buffer used for branch tracing in
3350   Intel Processor Trace format.
3351   The obtained size may differ from the requested size.  Use "info
3352   record" to see the obtained buffer size.
3353 
3354 maint set|show btrace pt skip-pad
3355   Set and show whether PAD packets are skipped when computing the
3356   packet history.
3357 
3358 * The command 'thread apply all' can now support new option '-ascending'
3359   to call its specified command for all threads in ascending order.
3360 
3361 * Python/Guile scripting
3362 
3363   ** GDB now supports auto-loading of Python/Guile scripts contained in the
3364      special section named `.debug_gdb_scripts'.
3365 
3366 * New remote packets
3367 
3368 qXfer:btrace-conf:read
3369   Return the branch trace configuration for the current thread.
3370 
3371 Qbtrace-conf:bts:size
3372   Set the requested ring buffer size for branch tracing in BTS format.
3373 
3374 Qbtrace:pt
3375   Enable Intel Processor Trace-based branch tracing for the current
3376   process.  The remote stub reports support for this packet to GDB's
3377   qSupported query.
3378 
3379 Qbtrace-conf:pt:size
3380   Set the requested ring buffer size for branch tracing in Intel Processor
3381   Trace format.
3382 
3383 swbreak stop reason
3384   Indicates a memory breakpoint instruction was executed, irrespective
3385   of whether it was GDB that planted the breakpoint or the breakpoint
3386   is hardcoded in the program.  This is required for correct non-stop
3387   mode operation.
3388 
3389 hwbreak stop reason
3390   Indicates the target stopped for a hardware breakpoint.  This is
3391   required for correct non-stop mode operation.
3392 
3393 vFile:fstat:
3394   Return information about files on the remote system.
3395 
3396 qXfer:exec-file:read
3397   Return the full absolute name of the file that was executed to
3398   create a process running on the remote system.
3399 
3400 vFile:setfs:
3401   Select the filesystem on which vFile: operations with filename
3402   arguments will operate.  This is required for GDB to be able to
3403   access files on remote targets where the remote stub does not
3404   share a common filesystem with the inferior(s).
3405 
3406 fork stop reason
3407   Indicates that a fork system call was executed.
3408 
3409 vfork stop reason
3410   Indicates that a vfork system call was executed.
3411 
3412 vforkdone stop reason
3413   Indicates that a vfork child of the specified process has executed
3414   an exec or exit, allowing the vfork parent to resume execution.
3415 
3416 fork-events and vfork-events features in qSupported
3417   The qSupported packet allows GDB to request support for fork and 
3418   vfork events using new 'gdbfeatures' fork-events and vfork-events,
3419   and the qSupported response can contain the corresponding
3420   'stubfeatures'.  Set and show commands can be used to display
3421   whether these features are enabled.
3422 
3423 * Extended-remote fork events
3424 
3425   ** GDB now has support for fork events on extended-remote Linux
3426      targets.  For targets with Linux kernels 2.5.60 and later, this
3427      enables follow-fork-mode and detach-on-fork for both fork and
3428      vfork, as well as fork and vfork catchpoints.
3429 
3430 * The info record command now shows the recording format and the
3431   branch tracing configuration for the current thread when using
3432   the btrace record target.
3433   For the BTS format, it shows the ring buffer size.
3434 
3435 * GDB now has support for DTrace USDT (Userland Static Defined
3436   Tracing) probes.  The supported targets are x86_64-*-linux-gnu.
3437 
3438 * GDB now supports access to vector registers on S/390 GNU/Linux
3439   targets.
3440 
3441 * Removed command line options
3442 
3443 -xdb  HP-UX XDB compatibility mode.
3444 
3445 * Removed targets and native configurations
3446 
3447 HP/PA running HP-UX           hppa*-*-hpux*
3448 Itanium running HP-UX         ia64-*-hpux*
3449 
3450 * New configure options
3451 
3452 --with-intel-pt
3453   This configure option allows the user to build GDB with support for
3454   Intel Processor Trace (default: auto).  This requires libipt.
3455 
3456 --with-libipt-prefix=PATH
3457   Specify the path to the version of libipt that GDB should use.
3458   $PATH/include should contain the intel-pt.h header and
3459   $PATH/lib should contain the libipt.so library.
3460 
3461 *** Changes in GDB 7.9.1
3462 
3463 * Python Scripting
3464 
3465   ** Xmethods can now specify a result type.
3466 
3467 *** Changes in GDB 7.9
3468 
3469 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3470 
3471 * Python Scripting
3472 
3473   ** You can now access frame registers from Python scripts.
3474   ** New attribute 'producer' for gdb.Symtab objects.
3475   ** gdb.Objfile objects have a new attribute "progspace",
3476      which is the gdb.Progspace object of the containing program space.
3477   ** gdb.Objfile objects have a new attribute "owner".
3478   ** gdb.Objfile objects have a new attribute "build_id",
3479      which is the build ID generated when the file was built.
3480   ** gdb.Objfile objects have a new method "add_separate_debug_file".
3481   ** A new event "gdb.clear_objfiles" has been added, triggered when
3482      selecting a new file to debug.
3483   ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3484   ** New function gdb.lookup_objfile.
3485 
3486   New events which are triggered when GDB modifies the state of the 
3487   inferior.
3488 
3489   ** gdb.events.inferior_call_pre: Function call is about to be made.
3490   ** gdb.events.inferior_call_post: Function call has just been made.
3491   ** gdb.events.memory_changed: A memory location has been altered.
3492   ** gdb.events.register_changed: A register has been altered.
3493 
3494 * New Python-based convenience functions:
3495 
3496   ** $_caller_is(name [, number_of_frames])
3497   ** $_caller_matches(regexp [, number_of_frames])
3498   ** $_any_caller_is(name [, number_of_frames])
3499   ** $_any_caller_matches(regexp [, number_of_frames])
3500 
3501 * GDB now supports the compilation and injection of source code into
3502   the inferior.  GDB will use GCC 5.0 or higher built with libcc1.so
3503   to compile the source code to object code, and if successful, inject
3504   and execute that code within the current context of the inferior.
3505   Currently the C language is supported.  The commands used to
3506   interface with this new feature are:
3507 
3508      compile code [-raw|-r] [--] [source code]
3509      compile file [-raw|-r] filename
3510 
3511 * New commands
3512 
3513 demangle [-l language] [--] name
3514   Demangle "name" in the specified language, or the current language
3515   if elided.  This command is renamed from the "maint demangle" command.
3516   The latter is kept as a no-op to avoid "maint demangle" being interpreted
3517   as "maint demangler-warning".
3518 
3519 queue-signal signal-name-or-number
3520   Queue a signal to be delivered to the thread when it is resumed.
3521 
3522 add-auto-load-scripts-directory directory
3523   Add entries to the list of directories from which to load auto-loaded
3524   scripts.
3525 
3526 maint print user-registers
3527   List all currently available "user" registers.
3528 
3529 compile code [-r|-raw] [--] [source code]
3530   Compile, inject, and execute in the inferior the executable object
3531   code produced by compiling the provided source code.
3532 
3533 compile file [-r|-raw] filename
3534   Compile and inject into the inferior the executable object code
3535   produced by compiling the source code stored in the filename
3536   provided.
3537 
3538 * On resume, GDB now always passes the signal the program had stopped
3539   for to the thread the signal was sent to, even if the user changed
3540   threads before resuming.  Previously GDB would often (but not
3541   always) deliver the signal to the thread that happens to be current
3542   at resume time.
3543 
3544 * Conversely, the "signal" command now consistently delivers the
3545   requested signal to the current thread.  GDB now asks for
3546   confirmation if the program had stopped for a signal and the user
3547   switched threads meanwhile.
3548 
3549 * "breakpoint always-inserted" modes "off" and "auto" merged.
3550 
3551   Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3552   won't remove breakpoints from the target until all threads stop,
3553   even in non-stop mode.  The "auto" mode has been removed, and "off"
3554   is now the default mode.
3555 
3556 * New options
3557 
3558 set debug symbol-lookup
3559 show debug symbol-lookup
3560   Control display of debugging info regarding symbol lookup.
3561 
3562 * MI changes
3563 
3564   ** The -list-thread-groups command outputs an exit-code field for
3565      inferiors that have exited.
3566 
3567 * New targets
3568 
3569 MIPS SDE                        mips*-sde*-elf*
3570 
3571 * Removed targets
3572 
3573 Support for these obsolete configurations has been removed.
3574 
3575 Alpha running OSF/1 (or Tru64)          alpha*-*-osf*
3576 SGI Irix-5.x                            mips-*-irix5*
3577 SGI Irix-6.x                            mips-*-irix6*
3578 VAX running (4.2 - 4.3 Reno) BSD        vax-*-bsd*
3579 VAX running Ultrix                      vax-*-ultrix*
3580 
3581 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3582   and "assf"), have been removed.  Use the "sharedlibrary" command, or
3583   its alias "share", instead.
3584 
3585 *** Changes in GDB 7.8
3586 
3587 * New command line options
3588 
3589 -D data-directory
3590   This is an alias for the --data-directory option.
3591 
3592 * GDB supports printing and modifying of variable length automatic arrays
3593   as specified in ISO C99.
3594 
3595 * The ARM simulator now supports instruction level tracing
3596   with or without disassembly.
3597 
3598 * Guile scripting
3599 
3600   GDB now has support for scripting using Guile.  Whether this is
3601   available is determined at configure time.
3602   Guile version 2.0 or greater is required.
3603   Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3604 
3605 * New commands (for set/show, see "New options" below)
3606 
3607 guile [code]
3608 gu [code]
3609   Invoke CODE by passing it to the Guile interpreter.
3610 
3611 guile-repl
3612 gr
3613   Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3614 
3615 info auto-load guile-scripts [regexp]
3616   Print the list of automatically loaded Guile scripts.
3617 
3618 * The source command is now capable of sourcing Guile scripts.
3619   This feature is dependent on the debugger being built with Guile support.
3620 
3621 * New options
3622 
3623 set print symbol-loading (off|brief|full)
3624 show print symbol-loading
3625   Control whether to print informational messages when loading symbol
3626   information for a file.  The default is "full", but when debugging
3627   programs with large numbers of shared libraries the amount of output
3628   becomes less useful.
3629 
3630 set guile print-stack (none|message|full)
3631 show guile print-stack
3632   Show a stack trace when an error is encountered in a Guile script.
3633 
3634 set auto-load guile-scripts (on|off)
3635 show auto-load guile-scripts
3636   Control auto-loading of Guile script files.
3637 
3638 maint ada set ignore-descriptive-types (on|off)
3639 maint ada show ignore-descriptive-types
3640   Control whether the debugger should ignore descriptive types in Ada
3641   programs.  The default is not to ignore the descriptive types.  See
3642   the user manual for more details on descriptive types and the intended
3643   usage of this option.
3644 
3645 set auto-connect-native-target
3646 
3647   Control whether GDB is allowed to automatically connect to the
3648   native target for the run, attach, etc. commands when not connected
3649   to any target yet.  See also "target native" below.
3650 
3651 set record btrace replay-memory-access (read-only|read-write)
3652 show record btrace replay-memory-access
3653   Control what memory accesses are allowed during replay.
3654 
3655 maint set target-async (on|off)
3656 maint show target-async
3657   This controls whether GDB targets operate in synchronous or
3658   asynchronous mode.  Normally the default is asynchronous, if it is
3659   available; but this can be changed to more easily debug problems
3660   occurring only in synchronous mode.
3661 
3662 set mi-async (on|off)
3663 show mi-async
3664   Control whether MI asynchronous mode is preferred.  This supersedes
3665   "set target-async" of previous GDB versions.
3666 
3667 * "set target-async" is deprecated as a CLI option and is now an alias
3668   for "set mi-async" (only puts MI into async mode).
3669 
3670 * Background execution commands (e.g., "c&", "s&", etc.) are now
3671   possible ``out of the box'' if the target supports them.  Previously
3672   the user would need to explicitly enable the possibility with the
3673   "set target-async on" command.
3674 
3675 * New features in the GDB remote stub, GDBserver
3676 
3677   ** New option --debug-format=option1[,option2,...] allows one to add
3678      additional text to each output.  At present only timestamps
3679      are supported: --debug-format=timestamps.
3680      Timestamps can also be turned on with the
3681      "monitor set debug-format timestamps" command from GDB.
3682 
3683 * The 'record instruction-history' command now starts counting instructions
3684   at one.  This also affects the instruction ranges reported by the
3685   'record function-call-history' command when given the /i modifier.
3686 
3687 * The command 'record function-call-history' supports a new modifier '/c' to
3688   indent the function names based on their call stack depth.
3689   The fields for the '/i' and '/l' modifier have been reordered.
3690   The source line range is now prefixed with 'at'.
3691   The instruction range is now prefixed with 'inst'.
3692   Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3693   "record instruction-history" and "list" commands.
3694 
3695 * The ranges given as arguments to the 'record function-call-history' and
3696   'record instruction-history' commands are now inclusive.
3697 
3698 * The btrace record target now supports the 'record goto' command.
3699   For locations inside the execution trace, the back trace is computed
3700   based on the information stored in the execution trace.
3701 
3702 * The btrace record target supports limited reverse execution and replay.
3703   The target does not record data and therefore does not allow reading
3704   memory or registers.
3705 
3706 * The "catch syscall" command now works on s390*-linux* targets.
3707 
3708 * The "compare-sections" command is no longer specific to target
3709   remote.  It now works with all targets.
3710 
3711 * All native targets are now consistently called "native".
3712   Consequently, the "target child", "target GNU", "target djgpp",
3713   "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3714   commands have been replaced with "target native".  The QNX/NTO port
3715   leaves the "procfs" target in place and adds a "native" target for
3716   consistency with other ports.  The impact on users should be minimal
3717   as these commands previously either throwed an error, or were
3718   no-ops.  The target's name is visible in the output of the following
3719   commands: "help target", "info target", "info files", "maint print
3720   target-stack".
3721 
3722 * The "target native" command now connects to the native target.  This
3723   can be used to launch native programs even when "set
3724   auto-connect-native-target" is set to off.
3725 
3726 * GDB now supports access to Intel MPX registers on GNU/Linux.
3727 
3728 * Support for Intel AVX-512 registers on GNU/Linux.
3729   Support displaying and modifying Intel AVX-512 registers
3730   $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3731 
3732 * New remote packets
3733 
3734 qXfer:btrace:read's annex
3735   The qXfer:btrace:read packet supports a new annex 'delta' to read
3736   branch trace incrementally.
3737 
3738 * Python Scripting
3739 
3740   ** Valid Python operations on gdb.Value objects representing
3741      structs/classes invoke the corresponding overloaded operators if
3742      available.
3743   ** New `Xmethods' feature in the Python API.  Xmethods are
3744      additional methods or replacements for existing methods of a C++
3745      class.  This feature is useful for those cases where a method
3746      defined in C++ source code could be inlined or optimized out by
3747      the compiler, making it unavailable to GDB.
3748 
3749 * New targets
3750 PowerPC64 GNU/Linux little-endian       powerpc64le-*-linux*
3751 
3752 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3753   and "assf"), have been deprecated.  Use the "sharedlibrary" command, or
3754   its alias "share", instead.
3755 
3756 * The commands "set remotebaud" and "show remotebaud" are no longer
3757   supported.  Use "set serial baud" and "show serial baud" (respectively)
3758   instead.
3759 
3760 * MI changes
3761 
3762   ** A new option "-gdb-set mi-async" replaces "-gdb-set
3763      target-async".  The latter is left as a deprecated alias of the
3764      former for backward compatibility.  If the target supports it,
3765      CLI background execution commands are now always possible by
3766      default, independently of whether the frontend stated a
3767      preference for asynchronous execution with "-gdb-set mi-async".
3768      Previously "-gdb-set target-async off" affected both MI execution
3769      commands and CLI execution commands.
3770 
3771 *** Changes in GDB 7.7
3772 
3773 * Improved support for process record-replay and reverse debugging on
3774   arm*-linux* targets.  Support for thumb32 and syscall instruction
3775   recording has been added.
3776 
3777 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3778 
3779 * GDB now supports Fission DWP file format version 2.
3780   http://gcc.gnu.org/wiki/DebugFission
3781 
3782 * New convenience function "$_isvoid", to check whether an expression
3783   is void.  A void expression is an expression where the type of the
3784   result is "void".  For example, some convenience variables may be
3785   "void" when evaluated (e.g., "$_exitcode" before the execution of
3786   the program being debugged; or an undefined convenience variable).
3787   Another example, when calling a function whose return type is
3788   "void".
3789 
3790 * The "maintenance print objfiles" command now takes an optional regexp.
3791 
3792 * The "catch syscall" command now works on arm*-linux* targets.
3793 
3794 * GDB now consistently shows "<not saved>" when printing values of
3795   registers the debug info indicates have not been saved in the frame
3796   and there's nowhere to retrieve them from
3797   (callee-saved/call-clobbered registers):
3798 
3799     (gdb) p $rax
3800     $1 = <not saved>
3801 
3802     (gdb) info registers rax
3803     rax            <not saved>
3804 
3805   Before, the former would print "<optimized out>", and the latter
3806   "*value not available*".
3807 
3808 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3809   to binaries.
3810 
3811 * Python scripting
3812 
3813   ** Frame filters and frame decorators have been added.
3814   ** Temporary breakpoints are now supported.
3815   ** Line tables representation has been added.
3816   ** New attribute 'parent_type' for gdb.Field objects.
3817   ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3818   ** New attribute 'name' for gdb.Type objects.
3819 
3820 * New targets
3821 
3822 Nios II ELF                     nios2*-*-elf
3823 Nios II GNU/Linux               nios2*-*-linux
3824 Texas Instruments MSP430        msp430*-*-elf
3825 
3826 * Removed native configurations
3827 
3828 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3829 been removed.  ELF variants of these configurations are kept supported.
3830 
3831 arm*-*-netbsd*              but arm*-*-netbsdelf*       is kept supported.
3832 i[34567]86-*-netbsd*        but i[34567]86-*-netbsdelf* is kept supported.
3833 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd*   is kept supported.
3834 i[34567]86-*-openbsd3.[0-3]
3835 m68*-*-netbsd*              but m68*-*-netbsdelf*       is kept supported.
3836 sparc-*-netbsd*             but sparc-*-netbsdelf*      is kept supported.
3837 vax-*-netbsd*               but vax-*-netbsdelf*        is kept supported.
3838 
3839 * New commands:
3840 catch rethrow
3841   Like "catch throw", but catches a re-thrown exception.
3842 maint check-psymtabs
3843   Renamed from old "maint check-symtabs".
3844 maint check-symtabs
3845   Perform consistency checks on symtabs.
3846 maint expand-symtabs
3847   Expand symtabs matching an optional regexp.
3848 
3849 show configuration
3850   Display the details of GDB configure-time options.
3851 
3852 maint set|show per-command
3853 maint set|show per-command space
3854 maint set|show per-command time
3855 maint set|show per-command symtab
3856   Enable display of per-command gdb resource usage.
3857 
3858 remove-symbol-file FILENAME
3859 remove-symbol-file -a ADDRESS
3860   Remove a symbol file added via add-symbol-file.  The file to remove
3861   can be identified by its filename or by an address that lies within
3862   the boundaries of this symbol file in memory.
3863 
3864 info exceptions
3865 info exceptions REGEXP
3866   Display the list of Ada exceptions defined in the program being
3867   debugged.  If provided, only the exceptions whose names match REGEXP
3868   are listed.
3869 
3870 * New options
3871 
3872 set debug symfile off|on
3873 show debug symfile
3874   Control display of debugging info regarding reading symbol files and
3875   symbol tables within those files
3876 
3877 set print raw frame-arguments
3878 show print raw frame-arguments
3879   Set/show whether to print frame arguments in raw mode,
3880   disregarding any defined pretty-printers.
3881 
3882 set remote trace-status-packet
3883 show remote trace-status-packet
3884   Set/show the use of remote protocol qTStatus packet.
3885 
3886 set debug nios2
3887 show debug nios2
3888   Control display of debugging messages related to Nios II targets.
3889 
3890 set range-stepping
3891 show range-stepping
3892   Control whether target-assisted range stepping is enabled.
3893 
3894 set startup-with-shell
3895 show startup-with-shell
3896   Specifies whether Unix child processes are started via a shell or
3897   directly.
3898 
3899 set code-cache
3900 show code-cache
3901   Use the target memory cache for accesses to the code segment.  This
3902   improves performance of remote debugging (particularly disassembly).
3903 
3904 * You can now use a literal value 'unlimited' for options that
3905   interpret 0 or -1 as meaning "unlimited".  E.g., "set
3906   trace-buffer-size unlimited" is now an alias for "set
3907   trace-buffer-size -1" and "set height unlimited" is now an alias for
3908   "set height 0".
3909 
3910 * The "set debug symtab-create" debugging option of GDB has been changed to
3911   accept a verbosity level.  0 means "off", 1 provides basic debugging
3912   output, and values of 2 or greater provides more verbose output.
3913 
3914 * New command-line options
3915 --configuration
3916   Display the details of GDB configure-time options.
3917 
3918 * The command 'tsave' can now support new option '-ctf' to save trace
3919   buffer in Common Trace Format.
3920 
3921 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3922   GDB command gcore.
3923 
3924 * GDB now implements the C++ 'typeid' operator.
3925 
3926 * The new convenience variable $_exception holds the exception being
3927   thrown or caught at an exception-related catchpoint.
3928 
3929 * The exception-related catchpoints, like "catch throw", now accept a
3930   regular expression which can be used to filter exceptions by type.
3931 
3932 * The new convenience variable $_exitsignal is automatically set to
3933   the terminating signal number when the program being debugged dies
3934   due to an uncaught signal.
3935 
3936 * MI changes
3937 
3938   ** All MI commands now accept an optional "--language" option.
3939      Support for this feature can be verified by using the "-list-features"
3940      command, which should contain "language-option".
3941 
3942   ** The new command -info-gdb-mi-command allows the user to determine
3943      whether a GDB/MI command is supported or not.
3944 
3945   ** The "^error" result record returned when trying to execute an undefined
3946      GDB/MI command now provides a variable named "code" whose content is the
3947      "undefined-command" error code.  Support for this feature can be verified
3948      by using the "-list-features" command, which should contain
3949      "undefined-command-error-code".
3950 
3951   ** The -trace-save MI command can optionally save trace buffer in Common
3952      Trace Format now.
3953 
3954   ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3955 
3956   ** The command -data-list-register-values now accepts an optional
3957      "--skip-unavailable" option.  When used, only the available registers
3958      are displayed.
3959 
3960   ** The new command -trace-frame-collected dumps collected variables,
3961      computed expressions, tvars, memory and registers in a traceframe.
3962 
3963   ** The commands -stack-list-locals, -stack-list-arguments and
3964      -stack-list-variables now accept an option "--skip-unavailable".
3965      When used, only the available locals or arguments are displayed.
3966 
3967   ** The -exec-run command now accepts an optional "--start" option.
3968      When used, the command follows the same semantics as the "start"
3969      command, stopping the program's execution at the start of its
3970      main subprogram.  Support for this feature can be verified using
3971      the "-list-features" command, which should contain
3972      "exec-run-start-option".
3973 
3974   ** The new commands -catch-assert and -catch-exceptions insert
3975      catchpoints stopping the program when Ada exceptions are raised.
3976 
3977   ** The new command -info-ada-exceptions provides the equivalent of
3978      the new "info exceptions" command.
3979 
3980 * New system-wide configuration scripts
3981   A GDB installation now provides scripts suitable for use as system-wide
3982   configuration scripts for the following systems:
3983     ** ElinOS
3984     ** Wind River Linux
3985 
3986 * GDB now supports target-assigned range stepping with remote targets.
3987   This improves the performance of stepping source lines by reducing
3988   the number of control packets from/to GDB.  See "New remote packets"
3989   below.
3990 
3991 * GDB now understands the element 'tvar' in the XML traceframe info.
3992   It has the id of the collected trace state variables.
3993 
3994 * On S/390 targets that provide the transactional-execution feature,
3995   the program interruption transaction diagnostic block (TDB) is now
3996   represented as a number of additional "registers" in GDB.
3997 
3998 * New remote packets
3999 
4000 vCont;r
4001 
4002   The vCont packet supports a new 'r' action, that tells the remote
4003   stub to step through an address range itself, without GDB
4004   involvemement at each single-step.
4005 
4006 qXfer:libraries-svr4:read's annex
4007   The previously unused annex of the qXfer:libraries-svr4:read packet
4008   is now used to support passing an argument list.  The remote stub
4009   reports support for this argument list to GDB's qSupported query.
4010   The defined arguments are "start" and "prev", used to reduce work
4011   necessary for library list updating, resulting in significant
4012   speedup.
4013 
4014 * New features in the GDB remote stub, GDBserver
4015 
4016   ** GDBserver now supports target-assisted range stepping.  Currently
4017      enabled on x86/x86_64 GNU/Linux targets.
4018 
4019   ** GDBserver now adds element 'tvar' in the XML in the reply to
4020      'qXfer:traceframe-info:read'.  It has the id of the collected
4021      trace state variables.
4022 
4023   ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
4024      target.
4025 
4026 * New 'z' formatter for printing and examining memory, this displays the
4027   value as hexadecimal zero padded on the left to the size of the type.
4028 
4029 * GDB can now use Windows x64 unwinding data.
4030 
4031 * The "set remotebaud" command has been replaced by "set serial baud".
4032   Similarly, "show remotebaud" has been replaced by "show serial baud".
4033   The "set remotebaud" and "show remotebaud" commands are still available
4034   to provide backward compatibility with older versions of GDB.
4035 
4036 *** Changes in GDB 7.6
4037 
4038 * Target record has been renamed to record-full.
4039   Record/replay is now enabled with the "record full" command.
4040   This also affects settings that are associated with full record/replay
4041   that have been moved from "set/show record" to "set/show record full":
4042 
4043 set|show record full insn-number-max
4044 set|show record full stop-at-limit
4045 set|show record full memory-query
4046 
4047 * A new record target "record-btrace" has been added.  The new target
4048   uses hardware support to record the control-flow of a process.  It
4049   does not support replaying the execution, but it implements the
4050   below new commands for investigating the recorded execution log.
4051   This new recording method can be enabled using:
4052 
4053 record btrace
4054 
4055   The "record-btrace" target is only available on Intel Atom processors
4056   and requires a Linux kernel 2.6.32 or later.
4057 
4058 * Two new commands have been added for record/replay to give information
4059   about the recorded execution without having to replay the execution.
4060   The commands are only supported by "record btrace".
4061 
4062 record instruction-history      prints the execution history at
4063                                 instruction granularity
4064 
4065 record function-call-history    prints the execution history at
4066                                 function granularity
4067 
4068 * New native configurations
4069 
4070 ARM AArch64 GNU/Linux           aarch64*-*-linux-gnu
4071 FreeBSD/powerpc                 powerpc*-*-freebsd
4072 x86_64/Cygwin                   x86_64-*-cygwin*
4073 Tilera TILE-Gx GNU/Linux        tilegx*-*-linux-gnu
4074 
4075 * New targets
4076 
4077 ARM AArch64                     aarch64*-*-elf
4078 ARM AArch64 GNU/Linux           aarch64*-*-linux
4079 Lynx 178 PowerPC                powerpc-*-lynx*178
4080 x86_64/Cygwin                   x86_64-*-cygwin*
4081 Tilera TILE-Gx GNU/Linux        tilegx*-*-linux
4082 
4083 * If the configured location of system.gdbinit file (as given by the
4084   --with-system-gdbinit option at configure time) is in the
4085   data-directory (as specified by --with-gdb-datadir at configure
4086   time) or in one of its subdirectories, then GDB will look for the
4087   system-wide init file in the directory specified by the
4088   --data-directory command-line option.
4089 
4090 * New command line options:
4091 
4092 -nh   Disables auto-loading of ~/.gdbinit, but still executes all the
4093       other initialization files, unlike -nx which disables all of them.
4094 
4095 * Removed command line options
4096 
4097 -epoch  This was used by the gdb mode in Epoch, an ancient fork of
4098         Emacs.
4099 
4100 * The 'ptype' and 'whatis' commands now accept an argument to control
4101   type formatting.
4102 
4103 * 'info proc' now works on some core files.
4104 
4105 * Python scripting
4106 
4107   ** Vectors can be created with gdb.Type.vector.
4108 
4109   ** Python's atexit.register now works in GDB.
4110 
4111   ** Types can be pretty-printed via a Python API.
4112 
4113   ** Python 3 is now supported (in addition to Python 2.4 or later)
4114 
4115   ** New class gdb.Architecture exposes GDB's internal representation
4116      of architecture in the Python API.
4117 
4118   ** New method Frame.architecture returns the gdb.Architecture object
4119      corresponding to the frame's architecture.
4120 
4121 * New Python-based convenience functions:
4122 
4123   ** $_memeq(buf1, buf2, length)
4124   ** $_streq(str1, str2)
4125   ** $_strlen(str)
4126   ** $_regex(str, regex)
4127 
4128 * The 'cd' command now defaults to using '~' (the home directory) if not
4129   given an argument.
4130 
4131 * The C++ ABI now defaults to the GNU v3 ABI.  This has been the
4132   default for GCC since November 2000.
4133 
4134 * The command 'forward-search' can now be abbreviated as 'fo'.
4135 
4136 * The command 'info tracepoints' can now display 'installed on target'
4137   or 'not installed on target' for each non-pending location of tracepoint.
4138 
4139 * New configure options
4140 
4141 --enable-libmcheck/--disable-libmcheck
4142   By default, development versions are built with -lmcheck on hosts
4143   that support it, in order to help track memory corruption issues.
4144   Release versions, on the other hand, are built without -lmcheck
4145   by default.  The --enable-libmcheck/--disable-libmcheck configure
4146   options allow the user to override that default.
4147 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4148   This configure option allows the user to build GDB with
4149   libbabeltrace using which GDB can read Common Trace Format data.
4150 
4151 * New commands (for set/show, see "New options" below)
4152 
4153 catch signal 
4154   Catch signals.  This is similar to "handle", but allows commands and
4155   conditions to be attached.
4156 
4157 maint info bfds
4158   List the BFDs known to GDB.
4159 
4160 python-interactive [command]
4161 pi [command]
4162   Start a Python interactive prompt, or evaluate the optional command
4163   and print the result of expressions.
4164 
4165 py [command]
4166   "py" is a new alias for "python".
4167 
4168 enable type-printer [name]...
4169 disable type-printer [name]...
4170   Enable or disable type printers.
4171 
4172 * Removed commands
4173 
4174   ** For the Renesas Super-H architecture, the "regs" command has been removed
4175      (has been deprecated in GDB 7.5), and "info all-registers" should be used
4176      instead.
4177 
4178 * New options
4179 
4180 set print type methods (on|off)
4181 show print type methods
4182   Control whether method declarations are displayed by "ptype".
4183   The default is to show them.
4184 
4185 set print type typedefs (on|off)
4186 show print type typedefs
4187   Control whether typedef definitions are displayed by "ptype".
4188   The default is to show them.
4189 
4190 set filename-display basename|relative|absolute
4191 show filename-display
4192   Control the way in which filenames is displayed.
4193   The default is "relative", which preserves previous behavior.
4194 
4195 set trace-buffer-size
4196 show trace-buffer-size
4197   Request target to change the size of trace buffer.
4198 
4199 set remote trace-buffer-size-packet auto|on|off
4200 show remote trace-buffer-size-packet
4201   Control the use of the remote protocol `QTBuffer:size' packet.
4202 
4203 set debug aarch64
4204 show debug aarch64
4205   Control display of debugging messages related to ARM AArch64.
4206   The default is off.
4207 
4208 set debug coff-pe-read
4209 show debug coff-pe-read
4210   Control display of debugging messages related to reading of COFF/PE
4211   exported symbols.
4212 
4213 set debug mach-o
4214 show debug mach-o
4215   Control display of debugging messages related to Mach-O symbols
4216   processing.
4217 
4218 set debug notification
4219 show debug notification
4220   Control display of debugging info for async remote notification.
4221 
4222 * MI changes
4223 
4224   ** Command parameter changes are now notified using new async record
4225      "=cmd-param-changed".
4226   ** Trace frame changes caused by command "tfind" are now notified using
4227      new async record "=traceframe-changed".
4228   ** The creation, deletion and modification of trace state variables
4229      are now notified using new async records "=tsv-created",
4230      "=tsv-deleted" and "=tsv-modified".
4231   ** The start and stop of process record are now notified using new
4232      async record "=record-started" and "=record-stopped".
4233   ** Memory changes are now notified using new async record
4234      "=memory-changed".
4235   ** The data-disassemble command response will include a "fullname" field
4236      containing the absolute file name when source has been requested.
4237   ** New optional parameter COUNT added to the "-data-write-memory-bytes" 
4238      command, to allow pattern filling of memory areas.
4239   ** New commands "-catch-load"/"-catch-unload" added for intercepting
4240      library load/unload events.
4241   ** The response to breakpoint commands and breakpoint async records
4242      includes an "installed" field containing a boolean state about each
4243      non-pending tracepoint location is whether installed on target or not.
4244   ** Output of the "-trace-status" command includes a "trace-file" field 
4245      containing the name of the trace file being examined.  This field is
4246      optional, and only present when examining a trace file.
4247   ** The "fullname" field is now always present along with the "file" field,
4248      even if the file cannot be found by GDB.
4249 
4250 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4251   You must have the LZMA library available when configuring GDB for this
4252   feature to be enabled.  For more information, see:
4253       http://fedoraproject.org/wiki/Features/MiniDebugInfo
4254 
4255 * New remote packets
4256 
4257 QTBuffer:size
4258    Set the size of trace buffer.  The remote stub reports support for this
4259    packet to gdb's qSupported query.
4260 
4261 Qbtrace:bts
4262   Enable Branch Trace Store (BTS)-based branch tracing for the current
4263   thread.  The remote stub reports support for this packet to gdb's
4264   qSupported query.
4265 
4266 Qbtrace:off
4267   Disable branch tracing for the current thread.  The remote stub reports
4268   support for this packet to gdb's qSupported query.
4269 
4270 qXfer:btrace:read
4271   Read the traced branches for the current thread.  The remote stub
4272   reports support for this packet to gdb's qSupported query.
4273 
4274 *** Changes in GDB 7.5
4275 
4276 * GDB now supports x32 ABI.  Visit <http://sites.google.com/site/x32abi/>
4277   for more x32 ABI info.
4278 
4279 * GDB now supports access to MIPS DSP registers on Linux targets.
4280 
4281 * GDB now supports debugging microMIPS binaries.
4282 
4283 * The "info os" command on GNU/Linux can now display information on
4284   several new classes of objects managed by the operating system:
4285     "info os procgroups" lists process groups
4286     "info os files" lists file descriptors
4287     "info os sockets" lists internet-domain sockets
4288     "info os shm" lists shared-memory regions
4289     "info os semaphores" lists semaphores
4290     "info os msg" lists message queues
4291     "info os modules" lists loaded kernel modules
4292 
4293 * GDB now has support for SDT (Static Defined Tracing) probes.  Currently,
4294   the only implemented backend is for SystemTap probes (<sys/sdt.h>).  You
4295   can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4296   options and inspect the probe arguments using the new $_probe_arg family
4297   of convenience variables.  You can obtain more information about SystemTap
4298   in <http://sourceware.org/systemtap/>.
4299 
4300 * GDB now supports reversible debugging on ARM, it allows you to
4301   debug basic ARM and THUMB instructions, and provides 
4302   record/replay support.  
4303 
4304 * The option "symbol-reloading" has been deleted as it is no longer used.
4305 
4306 * Python scripting
4307 
4308   ** GDB commands implemented in Python can now be put in command class
4309      "gdb.COMMAND_USER".
4310 
4311   ** The "maint set python print-stack on|off" is now deleted.
4312 
4313   ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4314      apply "flag enum"-style pretty-printing to any enum.
4315 
4316   ** gdb.lookup_symbol can now work when there is no current frame.
4317 
4318   ** gdb.Symbol now has a 'line' attribute, holding the line number in
4319      the source at which the symbol was defined.
4320 
4321   ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4322      method 'value'.  The former indicates whether the symbol needs a
4323      frame in order to compute its value, and the latter computes the
4324      symbol's value.
4325 
4326   ** A new method 'referenced_value' on gdb.Value objects which can
4327      dereference pointer as well as C++ reference values.
4328 
4329   ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4330      which return the global and static blocks (as gdb.Block objects),
4331      of the underlying symbol table, respectively.
4332 
4333   ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4334      object associated with a PC value.
4335 
4336   ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4337      of the address range occupied by code for the current source line.
4338 
4339 * Go language support.
4340   GDB now supports debugging programs written in the Go programming
4341   language.
4342 
4343 * GDBserver now supports stdio connections.
4344   E.g. (gdb) target remote | ssh myhost gdbserver - hello
4345 
4346 * The binary "gdbtui" can no longer be built or installed.
4347   Use "gdb -tui" instead.
4348 
4349 * GDB will now print "flag" enums specially.  A flag enum is one where
4350   all the enumerator values have no bits in common when pairwise
4351   "and"ed.  When printing a value whose type is a flag enum, GDB will
4352   show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4353   (gdb) print (enum E) 3
4354   $1 = (ONE | TWO)
4355 
4356 * The filename part of a linespec will now match trailing components
4357   of a source file name.  For example, "break gcc/expr.c:1000" will
4358   now set a breakpoint in build/gcc/expr.c, but not
4359   build/libcpp/expr.c.
4360 
4361 * The "info proc" and "generate-core-file" commands will now also
4362   work on remote targets connected to GDBserver on Linux.
4363 
4364 * The command "info catch" has been removed.  It has been disabled
4365   since December 2007.
4366 
4367 * The "catch exception" and "catch assert" commands now accept
4368   a condition at the end of the command, much like the "break"
4369   command does. For instance:
4370 
4371         (gdb) catch exception Constraint_Error if Barrier = True
4372 
4373   Previously, it was possible to add a condition to such catchpoints,
4374   but it had to be done as a second step, after the catchpoint had been
4375   created, using the "condition" command.
4376 
4377 * The "info static-tracepoint-marker" command will now also work on
4378   native Linux targets with in-process agent.
4379 
4380 * GDB can now set breakpoints on inlined functions.
4381 
4382 * The .gdb_index section has been updated to include symbols for
4383   inlined functions.  GDB will ignore older .gdb_index sections by
4384   default, which could cause symbol files to be loaded more slowly
4385   until their .gdb_index sections can be recreated.  The new command
4386   "set use-deprecated-index-sections on" will cause GDB to use any older
4387   .gdb_index sections it finds.  This will restore performance, but the
4388   ability to set breakpoints on inlined functions will be lost in symbol
4389   files with older .gdb_index sections.
4390 
4391   The .gdb_index section has also been updated to record more information
4392   about each symbol.  This speeds up the "info variables", "info functions"
4393   and "info types" commands when used with programs having the .gdb_index
4394   section, as well as speeding up debugging with shared libraries using
4395   the .gdb_index section.
4396 
4397 * Ada support for GDB/MI Variable Objects has been added.
4398 
4399 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4400   target.
4401 
4402 * MI changes
4403 
4404   ** New command -info-os is the MI equivalent of "info os".
4405 
4406   ** Output logs ("set logging" and related) now include MI output.
4407 
4408 * New commands
4409 
4410   ** "set use-deprecated-index-sections on|off"
4411      "show use-deprecated-index-sections on|off"
4412      Controls the use of deprecated .gdb_index sections.
4413 
4414   ** "catch load" and "catch unload" can be used to stop when a shared
4415      library is loaded or unloaded, respectively.
4416 
4417   ** "enable count" can be used to auto-disable a breakpoint after
4418      several hits.
4419 
4420   ** "info vtbl" can be used to show the virtual method tables for
4421      C++ and Java objects.
4422 
4423   ** "explore" and its sub commands "explore value" and "explore type"
4424      can be used to recursively explore values and types of
4425      expressions.  These commands are available only if GDB is
4426      configured with '--with-python'.
4427 
4428   ** "info auto-load" shows status of all kinds of auto-loaded files,
4429      "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4430      sequences of commands files, "info auto-load python-scripts"
4431      shows status of auto-loading Python script files,
4432      "info auto-load local-gdbinit" shows status of loading init file
4433      (.gdbinit) from current directory and "info auto-load libthread-db" shows
4434      status of inferior specific thread debugging shared library loading.
4435 
4436   ** "info auto-load-scripts", "set auto-load-scripts on|off"
4437      and "show auto-load-scripts" commands have been deprecated, use their
4438      "info auto-load python-scripts", "set auto-load python-scripts on|off"
4439      and "show auto-load python-scripts" counterparts instead.
4440 
4441   ** "dprintf location,format,args..." creates a dynamic printf, which
4442      is basically a breakpoint that does a printf and immediately
4443      resumes your program's execution, so it is like a printf that you
4444      can insert dynamically at runtime instead of at compiletime.
4445 
4446   ** "set print symbol"
4447      "show print symbol"
4448      Controls whether GDB attempts to display the symbol, if any,
4449      corresponding to addresses it prints.  This defaults to "on", but
4450      you can set it to "off" to restore GDB's previous behavior.
4451 
4452 * Deprecated commands
4453 
4454   ** For the Renesas Super-H architecture, the "regs" command has been
4455      deprecated, and "info all-registers" should be used instead.
4456 
4457 * New targets
4458 
4459 Renesas RL78                    rl78-*-elf
4460 HP OpenVMS ia64                 ia64-hp-openvms*
4461 
4462 * GDBserver supports evaluation of breakpoint conditions.  When
4463   support is advertised by GDBserver, GDB may be told to send the
4464   breakpoint conditions in bytecode form to GDBserver.  GDBserver
4465   will only report the breakpoint trigger to GDB when its condition
4466   evaluates to true.
4467 
4468 * New options
4469 
4470 set mips compression
4471 show mips compression
4472   Select the compressed ISA encoding used in functions that have no symbol
4473   information available.  The encoding can be set to either of:
4474     mips16
4475     micromips
4476   and is updated automatically from ELF file flags if available.
4477 
4478 set breakpoint condition-evaluation
4479 show breakpoint condition-evaluation
4480   Control whether breakpoint conditions are evaluated by GDB ("host") or by
4481   GDBserver ("target").  Default option "auto" chooses the most efficient
4482   available mode.
4483   This option can improve debugger efficiency depending on the speed of the
4484   target.
4485 
4486 set auto-load off
4487   Disable auto-loading globally.
4488 
4489 show auto-load
4490   Show auto-loading setting of all kinds of auto-loaded files.
4491 
4492 set auto-load gdb-scripts on|off
4493 show auto-load gdb-scripts
4494   Control auto-loading of GDB canned sequences of commands files.
4495 
4496 set auto-load python-scripts on|off
4497 show auto-load python-scripts
4498   Control auto-loading of Python script files.
4499 
4500 set auto-load local-gdbinit on|off
4501 show auto-load local-gdbinit
4502   Control loading of init file (.gdbinit) from current directory.
4503 
4504 set auto-load libthread-db on|off
4505 show auto-load libthread-db
4506   Control auto-loading of inferior specific thread debugging shared library.
4507 
4508 set auto-load scripts-directory <dir1>[:<dir2>...]
4509 show auto-load scripts-directory
4510   Set a list of directories from which to load auto-loaded scripts.
4511   Automatically loaded Python scripts and GDB scripts are located in one
4512   of the directories listed by this option.
4513   The delimiter (':' above) may differ according to the host platform.
4514 
4515 set auto-load safe-path <dir1>[:<dir2>...]
4516 show auto-load safe-path
4517   Set a list of directories from which it is safe to auto-load files.
4518   The delimiter (':' above) may differ according to the host platform.
4519 
4520 set debug auto-load on|off
4521 show debug auto-load
4522   Control display of debugging info for auto-loading the files above.
4523 
4524 set dprintf-style gdb|call|agent
4525 show dprintf-style
4526   Control the way in which a dynamic printf is performed; "gdb"
4527   requests a GDB printf command, while "call" causes dprintf to call a
4528   function in the inferior.  "agent" requests that the target agent
4529   (such as GDBserver) do the printing.
4530 
4531 set dprintf-function <expr>
4532 show dprintf-function
4533 set dprintf-channel <expr>
4534 show dprintf-channel
4535   Set the function and optional first argument to the call when using
4536   the "call" style of dynamic printf.
4537 
4538 set disconnected-dprintf on|off
4539 show disconnected-dprintf
4540   Control whether agent-style dynamic printfs continue to be in effect
4541   after GDB disconnects.
4542 
4543 * New configure options
4544 
4545 --with-auto-load-dir
4546   Configure default value for the 'set auto-load scripts-directory'
4547   setting above.  It defaults to '$debugdir:$datadir/auto-load',
4548   $debugdir representing global debugging info directories (available
4549   via 'show debug-file-directory') and $datadir representing GDB's data
4550   directory (available via 'show data-directory').
4551 
4552 --with-auto-load-safe-path
4553   Configure default value for the 'set auto-load safe-path' setting
4554   above.  It defaults to the --with-auto-load-dir setting.
4555 
4556 --without-auto-load-safe-path
4557   Set 'set auto-load safe-path' to '/', effectively disabling this
4558   security feature.
4559 
4560 * New remote packets
4561 
4562 z0/z1 conditional breakpoints extension
4563 
4564   The z0/z1 breakpoint insertion packets have been extended to carry
4565   a list of conditional expressions over to the remote stub depending on the
4566   condition evaluation mode.  The use of this extension can be controlled
4567   via the "set remote conditional-breakpoints-packet" command.
4568 
4569 QProgramSignals:
4570 
4571   Specify the signals which the remote stub may pass to the debugged
4572   program without GDB involvement.
4573 
4574 * New command line options
4575 
4576 --init-command=FILE, -ix          Like --command, -x but execute it
4577                                   before loading inferior.
4578 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4579                                   execute it before loading inferior.
4580 
4581 *** Changes in GDB 7.4
4582 
4583 * GDB now handles ambiguous linespecs more consistently; the existing
4584   FILE:LINE support has been expanded to other types of linespecs.  A
4585   breakpoint will now be set on all matching locations in all
4586   inferiors, and locations will be added or removed according to
4587   inferior changes.
4588 
4589 * GDB now allows you to skip uninteresting functions and files when
4590   stepping with the "skip function" and "skip file" commands.
4591 
4592 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4593   and "show remote hardware-watchpoint-length-limit".  These allows to
4594   set or show the maximum length limit (in bytes) of a remote
4595   target hardware watchpoint.
4596 
4597   This allows e.g. to use "unlimited" hardware watchpoints with the
4598   gdbserver integrated in Valgrind version >= 3.7.0.  Such Valgrind
4599   watchpoints are slower than real hardware watchpoints but are
4600   significantly faster than gdb software watchpoints.
4601 
4602 * Python scripting
4603 
4604   ** The register_pretty_printer function in module gdb.printing now takes
4605      an optional `replace' argument.  If True, the new printer replaces any
4606      existing one.
4607 
4608   ** The "maint set python print-stack on|off" command has been
4609      deprecated and will be deleted in GDB 7.5.
4610      A new command: "set python print-stack none|full|message" has
4611      replaced it.  Additionally, the default for "print-stack" is
4612      now "message", which just prints the error message without
4613      the stack trace.
4614    
4615   ** A prompt substitution hook (prompt_hook) is now available to the
4616      Python API.
4617 
4618   ** A new Python module, gdb.prompt has been added to the GDB Python
4619      modules library.  This module provides functionality for
4620      escape sequences in prompts (used by set/show
4621      extended-prompt).  These escape sequences are replaced by their
4622      corresponding value.
4623 
4624   ** Python commands and convenience-functions located in
4625     'data-directory'/python/gdb/command and
4626     'data-directory'/python/gdb/function are now automatically loaded
4627      on GDB start-up.
4628 
4629   ** Blocks now provide four new attributes.  global_block and
4630      static_block will return the global and static blocks
4631      respectively.  is_static and is_global are boolean attributes
4632      that indicate if the block is one of those two types.
4633 
4634   ** Symbols now provide the "type" attribute, the type of the symbol.
4635 
4636   ** The "gdb.breakpoint" function has been deprecated in favor of
4637      "gdb.breakpoints".
4638 
4639   ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4640      of a function.  This class is based on the "finish" command
4641      available in the CLI. 
4642 
4643   ** Type objects for struct and union types now allow access to
4644      the fields using standard Python dictionary (mapping) methods.
4645      For example, "some_type['myfield']" now works, as does
4646      "some_type.items()".
4647 
4648   ** A new event "gdb.new_objfile" has been added, triggered by loading a
4649      new object file.
4650 
4651   ** A new function, "deep_items" has been added to the gdb.types
4652      module in the GDB Python modules library.  This function returns
4653      an iterator over the fields of a struct or union type.  Unlike
4654      the standard Python "iteritems" method, it will recursively traverse
4655      any anonymous fields.
4656 
4657 * MI changes
4658 
4659   ** "*stopped" events can report several new "reason"s, such as
4660      "solib-event".
4661 
4662   ** Breakpoint changes are now notified using new async records, like
4663      "=breakpoint-modified".
4664 
4665   ** New command -ada-task-info.
4666 
4667 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4668   $sdir specifies the default system locations of shared libraries.
4669   $pdir specifies the directory where the libpthread used by the application
4670   lives.
4671 
4672   GDB no longer looks in $sdir and $pdir after it has searched the directories
4673   mentioned in libthread-db-search-path.  If you want to search those
4674   directories, they must be specified in libthread-db-search-path.
4675   The default value of libthread-db-search-path on GNU/Linux and Solaris
4676   systems is now "$sdir:$pdir".
4677 
4678   $pdir is not supported by gdbserver, it is currently ignored.
4679   $sdir is supported by gdbserver.
4680 
4681 * New configure option --with-iconv-bin.
4682   When using the internationalization support like the one in the GNU C
4683   library, GDB will invoke the "iconv" program to get a list of supported
4684   character sets.  If this program lives in a non-standard location, one can
4685   use this option to specify where to find it.
4686 
4687 * When natively debugging programs on PowerPC BookE processors running
4688   a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4689   watchpoints, which specify a mask in addition to an address to watch.
4690   The mask specifies that some bits of an address (the bits which are
4691   reset in the mask) should be ignored when matching the address accessed
4692   by the inferior against the watchpoint address.  See the "PowerPC Embedded"
4693   section in the user manual for more details.
4694 
4695 * The new option --once causes GDBserver to stop listening for connections once
4696   the first connection is made.  The listening port used by GDBserver will
4697   become available after that.
4698 
4699 * New commands "info macros" and "alias" have been added.
4700 
4701 * New function parameters suffix @entry specifies value of function parameter
4702   at the time the function got called.  Entry values are available only since
4703   gcc version 4.7.
4704 
4705 * New commands
4706 
4707 !SHELL COMMAND
4708   "!" is now an alias of the "shell" command.
4709   Note that no space is needed between "!" and SHELL COMMAND.
4710 
4711 * Changed commands
4712 
4713 watch EXPRESSION mask MASK_VALUE
4714   The watch command now supports the mask argument which allows creation
4715   of masked watchpoints, if the current architecture supports this feature.
4716 
4717 info auto-load-scripts [REGEXP]
4718   This command was formerly named "maintenance print section-scripts".
4719   It is now generally useful and is no longer a maintenance-only command.
4720 
4721 info macro [-all] [--] MACRO
4722   The info macro command has new options `-all' and `--'.  The first for
4723   printing all definitions of a macro.  The second for explicitly specifying
4724   the end of arguments and the beginning of the macro name in case the macro
4725   name starts with a hyphen.
4726 
4727 collect[/s] EXPRESSIONS
4728   The tracepoint collect command now takes an optional modifier "/s"
4729   that directs it to dereference pointer-to-character types and
4730   collect the bytes of memory up to a zero byte.  The behavior is
4731   similar to what you see when you use the regular print command on a
4732   string.  An optional integer following the "/s" sets a bound on the
4733   number of bytes that will be collected.
4734 
4735 tstart [NOTES]
4736   The trace start command now interprets any supplied arguments as a
4737   note to be recorded with the trace run, with an effect similar to
4738   setting the variable trace-notes.
4739 
4740 tstop [NOTES]
4741   The trace stop command now interprets any arguments as a note to be
4742   mentioned along with the tstatus report that the trace was stopped
4743   with a command.  The effect is similar to setting the variable
4744   trace-stop-notes.
4745 
4746 * Tracepoints can now be enabled and disabled at any time after a trace
4747   experiment has been started using the standard "enable" and "disable"
4748   commands.  It is now possible to start a trace experiment with no enabled
4749   tracepoints; GDB will display a warning, but will allow the experiment to
4750   begin, assuming that tracepoints will be enabled as needed while the trace
4751   is running.
4752 
4753 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4754   locations with 4-byte instructions, when they were previously
4755   limited to locations with instructions of 5 bytes or longer.
4756 
4757 * New options
4758 
4759 set debug dwarf2-read
4760 show debug dwarf2-read
4761   Turns on or off display of debugging messages related to reading
4762   DWARF debug info.  The default is off.
4763 
4764 set debug symtab-create
4765 show debug symtab-create
4766   Turns on or off display of debugging messages related to symbol table
4767   creation.  The default is off.
4768 
4769 set extended-prompt
4770 show extended-prompt
4771   Set the GDB prompt, and allow escape sequences to be inserted to
4772   display miscellaneous information (see 'help set extended-prompt'
4773   for the list of sequences).  This prompt (and any information
4774   accessed through the escape sequences) is updated every time the
4775   prompt is displayed.
4776 
4777 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4778 show print entry-values
4779   Set printing of frame argument values at function entry.  In some cases
4780   GDB can determine the value of function argument which was passed by the
4781   function caller, even if the value was modified inside the called function.
4782 
4783 set debug entry-values
4784 show debug entry-values
4785   Control display of debugging info for determining frame argument values at
4786   function entry and virtual tail call frames.
4787 
4788 set basenames-may-differ
4789 show basenames-may-differ
4790   Set whether a source file may have multiple base names.
4791   (A "base name" is the name of a file with the directory part removed.
4792   Example: The base name of "/home/user/hello.c" is "hello.c".)
4793   If set, GDB will canonicalize file names (e.g., expand symlinks)
4794   before comparing them.  Canonicalization is an expensive operation,
4795   but it allows the same file be known by more than one base name.
4796   If not set (the default), all source files are assumed to have just
4797   one base name, and gdb will do file name comparisons more efficiently.
4798 
4799 set trace-user
4800 show trace-user
4801 set trace-notes
4802 show trace-notes
4803   Set a user name and notes for the current and any future trace runs.
4804   This is useful for long-running and/or disconnected traces, to
4805   inform others (or yourself) as to who is running the trace, supply
4806   contact information, or otherwise explain what is going on.
4807 
4808 set trace-stop-notes
4809 show trace-stop-notes
4810   Set a note attached to the trace run, that is displayed when the
4811   trace has been stopped by a tstop command.  This is useful for
4812   instance as an explanation, if you are stopping a trace run that was
4813   started by someone else.
4814 
4815 * New remote packets
4816 
4817 QTEnable
4818   
4819   Dynamically enable a tracepoint in a started trace experiment.
4820 
4821 QTDisable
4822 
4823   Dynamically disable a tracepoint in a started trace experiment.
4824 
4825 QTNotes
4826 
4827   Set the user and notes of the trace run.
4828 
4829 qTP
4830 
4831   Query the current status of a tracepoint.
4832 
4833 qTMinFTPILen
4834 
4835   Query the minimum length of instruction at which a fast tracepoint may
4836   be placed.
4837 
4838 * Dcache size (number of lines) and line-size are now runtime-configurable
4839   via "set dcache line" and "set dcache line-size" commands.
4840 
4841 * New targets
4842 
4843 Texas Instruments TMS320C6x             tic6x-*-*
4844 
4845 * New Simulators
4846 
4847 Renesas RL78                            rl78-*-elf
4848 
4849 *** Changes in GDB 7.3.1
4850 
4851 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4852 
4853 *** Changes in GDB 7.3
4854 
4855 * GDB has a new command: "thread find [REGEXP]".
4856   It finds the thread id whose name, target id, or thread extra info
4857   matches the given regular expression.
4858 
4859 * The "catch syscall" command now works on mips*-linux* targets.
4860 
4861 * The -data-disassemble MI command now supports modes 2 and 3 for
4862   dumping the instruction opcodes.
4863 
4864 * New command line options
4865 
4866 -data-directory DIR     Specify DIR as the "data-directory".
4867                         This is mostly for testing purposes.
4868 
4869 * The "maint set python auto-load on|off" command has been renamed to
4870   "set auto-load-scripts on|off".
4871 
4872 * GDB has a new command: "set directories".
4873   It is like the "dir" command except that it replaces the
4874   source path list instead of augmenting it.
4875 
4876 * GDB now understands thread names.
4877 
4878   On GNU/Linux, "info threads" will display the thread name as set by
4879   prctl or pthread_setname_np.
4880 
4881   There is also a new command, "thread name", which can be used to
4882   assign a name internally for GDB to display.
4883 
4884 * OpenCL C
4885   Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4886   has been integrated into GDB.
4887 
4888 * Python scripting
4889 
4890   ** The function gdb.Write now accepts an optional keyword 'stream'.
4891      This keyword, when provided, will direct the output to either
4892      stdout, stderr, or GDB's logging output.
4893 
4894   ** Parameters can now be be sub-classed in Python, and in particular
4895      you may implement the get_set_doc and get_show_doc functions.
4896      This improves how Parameter set/show documentation is processed
4897      and allows for more dynamic content.
4898 
4899   ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4900      Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4901      have an is_valid method.
4902 
4903   ** Breakpoints can now be sub-classed in Python, and in particular
4904      you may implement a 'stop' function that is executed each time
4905      the inferior reaches that breakpoint.   
4906 
4907   ** New function gdb.lookup_global_symbol looks up a global symbol.
4908 
4909   ** GDB values in Python are now callable if the value represents a
4910      function.  For example, if 'some_value' represents a function that
4911      takes two integer parameters and returns a value, you can call
4912      that function like so:
4913 
4914      result = some_value (10,20)
4915 
4916   ** Module gdb.types has been added.
4917      It contains a collection of utilities for working with gdb.Types objects:
4918      get_basic_type, has_field, make_enum_dict.
4919 
4920   ** Module gdb.printing has been added.
4921      It contains utilities for writing and registering pretty-printers.
4922      New classes: PrettyPrinter,  SubPrettyPrinter,
4923      RegexpCollectionPrettyPrinter.
4924      New function: register_pretty_printer.
4925 
4926   ** New commands "info pretty-printers", "enable pretty-printer" and
4927      "disable pretty-printer" have been added.
4928 
4929   ** gdb.parameter("directories") is now available.
4930 
4931   ** New function gdb.newest_frame returns the newest frame in the
4932      selected thread.
4933 
4934   ** The gdb.InferiorThread class has a new "name" attribute.  This
4935      holds the thread's name.
4936 
4937   ** Python Support for Inferior events.
4938      Python scripts can add observers to be notified of events
4939      occurring in the process being debugged.
4940      The following events are currently supported:
4941      - gdb.events.cont Continue event.
4942      - gdb.events.exited Inferior exited event.
4943      - gdb.events.stop Signal received, and Breakpoint hit events.
4944 
4945 * C++ Improvements:
4946 
4947   ** GDB now puts template parameters in scope when debugging in an
4948      instantiation.  For example, if you have:
4949 
4950      template<int X> int func (void) { return X; }
4951 
4952      then if you step into func<5>, "print X" will show "5".  This
4953      feature requires proper debuginfo support from the compiler; it
4954      was added to GCC 4.5.
4955 
4956   ** The motion commands "next", "finish", "until", and "advance" now
4957      work better when exceptions are thrown.  In particular, GDB will
4958      no longer lose control of the inferior; instead, the GDB will
4959      stop the inferior at the point at which the exception is caught.
4960      This functionality requires a change in the exception handling
4961      code that was introduced in GCC 4.5.
4962 
4963 * GDB now follows GCC's rules on accessing volatile objects when
4964   reading or writing target state during expression evaluation.
4965   One notable difference to prior behavior is that "print x = 0"
4966   no longer generates a read of x; the value of the assignment is
4967   now always taken directly from the value being assigned.
4968 
4969 * GDB now has some support for using labels in the program's source in
4970   linespecs.  For instance, you can use "advance label" to continue
4971   execution to a label.
4972 
4973 * GDB now has support for reading and writing a new .gdb_index
4974   section.  This section holds a fast index of DWARF debugging
4975   information and can be used to greatly speed up GDB startup and
4976   operation.  See the documentation for `save gdb-index' for details.
4977 
4978 * The "watch" command now accepts an optional "-location" argument.
4979   When used, this causes GDB to watch the memory referred to by the
4980   expression.  Such a watchpoint is never deleted due to it going out
4981   of scope.
4982 
4983 * GDB now supports thread debugging of core dumps on GNU/Linux.
4984 
4985   GDB now activates thread debugging using the libthread_db library
4986   when debugging GNU/Linux core dumps, similarly to when debugging
4987   live processes.  As a result, when debugging a core dump file, GDB
4988   is now able to display pthread_t ids of threads.  For example, "info
4989   threads" shows the same output as when debugging the process when it
4990   was live.  In earlier releases, you'd see something like this:
4991 
4992   (gdb) info threads
4993    * 1 LWP 6780  main () at main.c:10
4994 
4995   While now you see this:
4996 
4997   (gdb) info threads
4998    * 1 Thread 0x7f0f5712a700 (LWP 6780)  main () at main.c:10
4999 
5000   It is also now possible to inspect TLS variables when debugging core
5001   dumps.
5002 
5003   When debugging a core dump generated on a machine other than the one
5004   used to run GDB, you may need to point GDB at the correct
5005   libthread_db library with the "set libthread-db-search-path"
5006   command.  See the user manual for more details on this command.
5007 
5008 * When natively debugging programs on PowerPC BookE processors running
5009   a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
5010   which stop execution of the inferior whenever it executes an instruction
5011   at any address within the specified range.  See the "PowerPC Embedded"
5012   section in the user manual for more details.
5013 
5014 * New features in the GDB remote stub, GDBserver
5015 
5016   ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
5017      and i686 LynxOS (version 5.x).
5018 
5019   ** GDBserver is now supported on Blackfin Linux.
5020 
5021 * New native configurations
5022 
5023 ia64 HP-UX                      ia64-*-hpux*
5024 
5025 * New targets:
5026 
5027 Analog Devices, Inc. Blackfin Processor bfin-*
5028 
5029 * Ada task switching is now supported on sparc-elf targets when
5030   debugging a program using the Ravenscar Profile.  For more information,
5031   see the "Tasking Support when using the Ravenscar Profile" section
5032   in the GDB user manual.
5033 
5034 * Guile support was removed.
5035 
5036 * New features in the GNU simulator
5037 
5038   ** The --map-info flag lists all known core mappings.
5039 
5040   ** CFI flashes may be simulated via the "cfi" device.
5041 
5042 *** Changes in GDB 7.2
5043 
5044 * Shared library support for remote targets by default
5045 
5046   When GDB is configured for a generic, non-OS specific target, like
5047   for example, --target=arm-eabi or one of the many *-*-elf targets,
5048   GDB now queries remote stubs for loaded shared libraries using the
5049   `qXfer:libraries:read' packet.  Previously, shared library support
5050   was always disabled for such configurations.
5051 
5052 * C++ Improvements:
5053 
5054   ** Argument Dependent Lookup (ADL)
5055 
5056   In C++ ADL lookup directs function search to the namespaces of its
5057   arguments even if the namespace has not been imported.
5058   For example:
5059     namespace A
5060       { 
5061         class B { }; 
5062         void foo (B) { }
5063       }
5064     ...
5065     A::B b
5066     foo(b)
5067   Here the compiler will search for `foo' in the namespace of 'b'
5068   and find A::foo.  GDB now supports this.  This construct is commonly
5069   used in the Standard Template Library for operators.
5070 
5071   ** Improved User Defined Operator Support
5072 
5073   In addition to member operators, GDB now supports lookup of operators
5074   defined in a namespace and imported with a `using' directive, operators
5075   defined in the global scope, operators imported implicitly from an
5076   anonymous namespace, and the ADL operators mentioned in the previous
5077   entry.
5078   GDB now also supports proper overload resolution for all the previously
5079   mentioned flavors of operators.
5080 
5081   ** static const class members
5082 
5083   Printing of static const class members that are initialized in the
5084   class definition has been fixed.
5085 
5086 * Windows Thread Information Block access.
5087 
5088   On Windows targets, GDB now supports displaying the Windows Thread
5089   Information Block (TIB) structure.  This structure is visible either
5090   by using the new command `info w32 thread-information-block' or, by
5091   dereferencing the new convenience variable named `$_tlb', a
5092   thread-specific pointer to the TIB.  This feature is also supported
5093   when remote debugging using GDBserver.
5094 
5095 * Static tracepoints
5096 
5097   Static tracepoints are calls in the user program into a tracing
5098   library.  One such library is a port of the LTTng kernel tracer to
5099   userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
5100   When debugging with GDBserver, GDB now supports combining the GDB
5101   tracepoint machinery with such libraries.  For example: the user can
5102   use GDB to probe a static tracepoint marker (a call from the user
5103   program into the tracing library) with the new "strace" command (see
5104   "New commands" below).  This creates a "static tracepoint" in the
5105   breakpoint list, that can be manipulated with the same feature set
5106   as fast and regular tracepoints.  E.g., collect registers, local and
5107   global variables, collect trace state variables, and define
5108   tracepoint conditions.  In addition, the user can collect extra
5109   static tracepoint marker specific data, by collecting the new
5110   $_sdata internal variable.  When analyzing the trace buffer, you can
5111   inspect $_sdata like any other variable available to GDB.  For more
5112   information, see the "Tracepoints" chapter in GDB user manual.  New
5113   remote packets have been defined to support static tracepoints, see
5114   the "New remote packets" section below.
5115 
5116 * Better reconstruction of tracepoints after disconnected tracing
5117 
5118   GDB will attempt to download the original source form of tracepoint
5119   definitions when starting a trace run, and then will upload these
5120   upon reconnection to the target, resulting in a more accurate
5121   reconstruction of the tracepoints that are in use on the target.
5122 
5123 * Observer mode
5124 
5125   You can now exercise direct control over the ways that GDB can
5126   affect your program.  For instance, you can disallow the setting of
5127   breakpoints, so that the program can run continuously (assuming
5128   non-stop mode).  In addition, the "observer" variable is available
5129   to switch all of the different controls; in observer mode, GDB
5130   cannot affect the target's behavior at all, which is useful for
5131   tasks like diagnosing live systems in the field.
5132 
5133 * The new convenience variable $_thread holds the number of the
5134   current thread.
5135 
5136 * New remote packets
5137 
5138 qGetTIBAddr
5139 
5140   Return the address of the Windows Thread Information Block of a given thread.
5141 
5142 qRelocInsn
5143 
5144   In response to several of the tracepoint packets, the target may now
5145   also respond with a number of intermediate `qRelocInsn' request
5146   packets before the final result packet, to have GDB handle
5147   relocating an instruction to execute at a different address.  This
5148   is particularly useful for stubs that support fast tracepoints.  GDB
5149   reports support for this feature in the qSupported packet.
5150 
5151 qTfSTM, qTsSTM
5152 
5153   List static tracepoint markers in the target program.
5154 
5155 qTSTMat
5156 
5157   List static tracepoint markers at a given address in the target
5158   program.
5159 
5160 qXfer:statictrace:read
5161 
5162   Read the static trace data collected (by a `collect $_sdata'
5163   tracepoint action).  The remote stub reports support for this packet
5164   to gdb's qSupported query.
5165 
5166 QAllow
5167 
5168   Send the current settings of GDB's permission flags.
5169 
5170 QTDPsrc
5171 
5172   Send part of the source (textual) form of a tracepoint definition,
5173   which includes location, conditional, and action list.
5174 
5175 * The source command now accepts a -s option to force searching for the
5176   script in the source search path even if the script name specifies
5177   a directory.
5178 
5179 * New features in the GDB remote stub, GDBserver
5180 
5181   - GDBserver now support tracepoints (including fast tracepoints, and
5182     static tracepoints).  The feature is currently supported by the
5183     i386-linux and amd64-linux builds.  See the "Tracepoints support
5184     in gdbserver" section in the manual for more information.
5185 
5186     GDBserver JIT compiles the tracepoint's conditional agent
5187     expression bytecode into native code whenever possible for low
5188     overhead dynamic tracepoints conditionals.  For such tracepoints,
5189     an expression that examines program state is evaluated when the
5190     tracepoint is reached, in order to determine whether to capture
5191     trace data.  If the condition is simple and false, processing the
5192     tracepoint finishes very quickly and no data is gathered.
5193 
5194     GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5195     for static tracepoints support.
5196 
5197   - GDBserver now supports x86_64 Windows 64-bit debugging.
5198 
5199 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5200   it understands register description.
5201 
5202 * The --batch flag now disables pagination and queries.
5203 
5204 * X86 general purpose registers
5205 
5206   GDB now supports reading/writing byte, word and double-word x86
5207   general purpose registers directly.  This means you can use, say,
5208   $ah or $ax to refer, respectively, to the byte register AH and
5209   16-bit word register AX that are actually portions of the 32-bit
5210   register EAX or 64-bit register RAX.
5211 
5212 * The `commands' command now accepts a range of breakpoints to modify.
5213   A plain `commands' following a command that creates multiple
5214   breakpoints affects all the breakpoints set by that command.  This
5215   applies to breakpoints set by `rbreak', and also applies when a
5216   single `break' command creates multiple breakpoints (e.g.,
5217   breakpoints on overloaded c++ functions).
5218 
5219 * The `rbreak' command now accepts a filename specification as part of
5220   its argument, limiting the functions selected by the regex to those
5221   in the specified file.
5222 
5223 * Support for remote debugging Windows and SymbianOS shared libraries
5224   from Unix hosts has been improved.  Non Windows GDB builds now can
5225   understand target reported file names that follow MS-DOS based file
5226   system semantics, such as file names that include drive letters and
5227   use the backslash character as directory separator.  This makes it
5228   possible to transparently use the "set sysroot" and "set
5229   solib-search-path" on Unix hosts to point as host copies of the
5230   target's shared libraries.  See the new command "set
5231   target-file-system-kind" described below, and the "Commands to
5232   specify files" section in the user manual for more information.
5233 
5234 * New commands
5235 
5236 eval template, expressions...
5237   Convert the values of one or more expressions under the control
5238   of the string template to a command line, and call it.
5239 
5240 set target-file-system-kind unix|dos-based|auto
5241 show target-file-system-kind
5242   Set or show the assumed file system kind for target reported file
5243   names.
5244 
5245 save breakpoints <filename>
5246   Save all current breakpoint definitions to a file suitable for use
5247   in a later debugging session.  To read the saved breakpoint
5248   definitions, use the `source' command.
5249 
5250 `save tracepoints' is a new alias for `save-tracepoints'.  The latter
5251 is now deprecated.
5252 
5253 info static-tracepoint-markers
5254   Display information about static tracepoint markers in the target.
5255 
5256 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5257   Define a static tracepoint by probing a marker at the given
5258   function, line, address, or marker ID.
5259 
5260 set observer on|off
5261 show observer
5262   Enable and disable observer mode.
5263 
5264 set may-write-registers on|off
5265 set may-write-memory on|off
5266 set may-insert-breakpoints on|off
5267 set may-insert-tracepoints on|off
5268 set may-insert-fast-tracepoints on|off
5269 set may-interrupt on|off
5270   Set individual permissions for GDB effects on the target.  Note that
5271   some of these settings can have undesirable or surprising
5272   consequences, particularly when changed in the middle of a session.
5273   For instance, disabling the writing of memory can prevent
5274   breakpoints from being inserted, cause single-stepping to fail, or
5275   even crash your program, if you disable after breakpoints have been
5276   inserted.  However, GDB should not crash.
5277 
5278 set record memory-query on|off
5279 show record memory-query
5280   Control whether to stop the inferior if memory changes caused
5281   by an instruction cannot be recorded.
5282 
5283 * Changed commands
5284 
5285 disassemble
5286   The disassemble command now supports "start,+length" form of two arguments.
5287 
5288 * Python scripting
5289 
5290 ** GDB now provides a new directory location, called the python directory,
5291    where Python scripts written for GDB can be installed.  The location
5292    of that directory is <data-directory>/python, where <data-directory>
5293    is the GDB data directory.  For more details, see section `Scripting
5294    GDB using Python' in the manual.
5295 
5296 ** The GDB Python API now has access to breakpoints, symbols, symbol
5297    tables, program spaces, inferiors, threads and frame's code blocks.
5298    Additionally, GDB Parameters can now be created from the API, and
5299    manipulated via set/show in the CLI.
5300 
5301 ** New functions gdb.target_charset, gdb.target_wide_charset,
5302    gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5303 
5304 ** New exception gdb.GdbError.
5305 
5306 ** Pretty-printers are now also looked up in the current program space.
5307 
5308 ** Pretty-printers can now be individually enabled and disabled.
5309 
5310 ** GDB now looks for names of Python scripts to auto-load in a
5311    special section named `.debug_gdb_scripts', in addition to looking
5312    for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5313 
5314 * Tracepoint actions were unified with breakpoint commands. In particular,
5315 there are no longer differences in "info break" output for breakpoints and
5316 tracepoints and the "commands" command can be used for both tracepoints and
5317 regular breakpoints.
5318 
5319 * New targets
5320 
5321 ARM Symbian                     arm*-*-symbianelf*
5322 
5323 * D language support.
5324   GDB now supports debugging programs written in the D programming
5325   language.
5326 
5327 * GDB now supports the extended ptrace interface for PowerPC which is
5328   available since Linux kernel version 2.6.34.  This automatically enables
5329   any hardware breakpoints and additional hardware watchpoints available in
5330   the processor.  The old ptrace interface exposes just one hardware
5331   watchpoint and no hardware breakpoints.
5332 
5333 * GDB is now able to use the Data Value Compare (DVC) register available on
5334   embedded PowerPC processors to implement in hardware simple watchpoint
5335   conditions of the form:
5336 
5337   watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5338 
5339   This works in native GDB running on Linux kernels with the extended ptrace
5340   interface mentioned above.
5341 
5342 *** Changes in GDB 7.1
5343 
5344 * C++ Improvements
5345 
5346   ** Namespace Support
5347 
5348   GDB now supports importing of namespaces in C++.  This enables the
5349   user to inspect variables from imported namespaces.  Support for
5350   namepace aliasing has also been added.  So, if a namespace is 
5351   aliased in the current scope (e.g. namepace C=A; ) the user can 
5352   print variables using the alias (e.g. (gdb) print C::x).
5353 
5354   ** Bug Fixes
5355 
5356   All known bugs relating to the printing of virtual base class were
5357   fixed.  It is now possible to call overloaded static methods using a
5358   qualified name.
5359 
5360   ** Cast Operators
5361 
5362   The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5363   and reinterpret_cast<> are now handled by the C++ expression parser.
5364 
5365 * New targets
5366 
5367 Xilinx MicroBlaze               microblaze-*-*
5368 Renesas RX                      rx-*-elf
5369 
5370 * New Simulators
5371 
5372 Xilinx MicroBlaze               microblaze
5373 Renesas RX                      rx
5374 
5375 * Multi-program debugging.
5376 
5377   GDB now has support for multi-program (a.k.a. multi-executable or
5378   multi-exec) debugging.  This allows for debugging multiple inferiors
5379   simultaneously each running a different program under the same GDB
5380   session.  See "Debugging Multiple Inferiors and Programs" in the
5381   manual for more information.  This implied some user visible changes
5382   in the multi-inferior support.  For example, "info inferiors" now
5383   lists inferiors that are not running yet or that have exited
5384   already.  See also "New commands" and "New options" below.
5385 
5386 * New tracing features
5387 
5388   GDB's tracepoint facility now includes several new features:
5389 
5390   ** Trace state variables
5391 
5392   GDB tracepoints now include support for trace state variables, which
5393   are variables managed by the target agent during a tracing
5394   experiment.  They are useful for tracepoints that trigger each
5395   other, so for instance one tracepoint can count hits in a variable,
5396   and then a second tracepoint has a condition that is true when the
5397   count reaches a particular value.  Trace state variables share the
5398   $-syntax of GDB convenience variables, and can appear in both
5399   tracepoint actions and condition expressions.  Use the "tvariable"
5400   command to create, and "info tvariables" to view; see "Trace State
5401   Variables" in the manual for more detail.
5402 
5403   ** Fast tracepoints
5404 
5405   GDB now includes an option for defining fast tracepoints, which
5406   targets may implement more efficiently, such as by installing a jump
5407   into the target agent rather than a trap instruction.  The resulting
5408   speedup can be by two orders of magnitude or more, although the
5409   tradeoff is that some program locations on some target architectures
5410   might not allow fast tracepoint installation, for instance if the
5411   instruction to be replaced is shorter than the jump.  To request a
5412   fast tracepoint, use the "ftrace" command, with syntax identical to
5413   the regular trace command.
5414 
5415   ** Disconnected tracing
5416 
5417   It is now possible to detach GDB from the target while it is running
5418   a trace experiment, then reconnect later to see how the experiment
5419   is going.  In addition, a new variable disconnected-tracing lets you
5420   tell the target agent whether to continue running a trace if the
5421   connection is lost unexpectedly.
5422 
5423   ** Trace files
5424 
5425   GDB now has the ability to save the trace buffer into a file, and
5426   then use that file as a target, similarly to you can do with
5427   corefiles.  You can select trace frames, print data that was
5428   collected in them, and use tstatus to display the state of the
5429   tracing run at the moment that it was saved.  To create a trace
5430   file, use "tsave <filename>", and to use it, do "target tfile
5431   <name>".
5432 
5433   ** Circular trace buffer
5434 
5435   You can ask the target agent to handle the trace buffer as a
5436   circular buffer, discarding the oldest trace frames to make room for
5437   newer ones, by setting circular-trace-buffer to on.  This feature may
5438   not be available for all target agents.
5439 
5440 * Changed commands
5441 
5442 disassemble
5443   The disassemble command, when invoked with two arguments, now requires
5444   the arguments to be comma-separated.
5445 
5446 info variables
5447   The info variables command now displays variable definitions.  Files
5448   which only declare a variable are not shown.
5449 
5450 source
5451   The source command is now capable of sourcing Python scripts.
5452   This feature is dependent on the debugger being build with Python
5453   support.
5454 
5455   Related to this enhancement is also the introduction of a new command
5456   "set script-extension" (see below).
5457 
5458 * New commands (for set/show, see "New options" below)
5459 
5460 record save [<FILENAME>]
5461   Save a file (in core file format) containing the process record 
5462   execution log for replay debugging at a later time.
5463 
5464 record restore <FILENAME>
5465   Restore the process record execution log that was saved at an
5466   earlier time, for replay debugging.
5467 
5468 add-inferior [-copies <N>] [-exec <FILENAME>]
5469   Add a new inferior.
5470 
5471 clone-inferior [-copies <N>] [ID]
5472   Make a new inferior ready to execute the same program another
5473   inferior has loaded.
5474 
5475 remove-inferior ID
5476   Remove an inferior.
5477 
5478 maint info program-spaces
5479   List the program spaces loaded into GDB.
5480 
5481 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5482 show remote interrupt-sequence
5483   Allow the user to select one of ^C, a BREAK signal or BREAK-g
5484   as the sequence to the remote target in order to interrupt the execution.
5485   Ctrl-C is a default.  Some system prefers BREAK which is high level of
5486   serial line for some certain time.  Linux kernel prefers BREAK-g, a.k.a
5487   Magic SysRq g.  It is BREAK signal and character 'g'.
5488 
5489 set remote interrupt-on-connect [on | off]
5490 show remote interrupt-on-connect
5491   When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5492   remote target when gdb connects to it.  This is needed when you debug
5493   Linux kernel.
5494 
5495 set remotebreak [on | off]
5496 show remotebreak
5497 Deprecated.  Use "set/show remote interrupt-sequence" instead.
5498 
5499 tvariable $NAME [ = EXP ]
5500   Create or modify a trace state variable.
5501 
5502 info tvariables
5503   List trace state variables and their values.
5504 
5505 delete tvariable $NAME ...
5506   Delete one or more trace state variables.
5507 
5508 teval EXPR, ...
5509   Evaluate the given expressions without collecting anything into the
5510   trace buffer. (Valid in tracepoint actions only.)
5511 
5512 ftrace FN / FILE:LINE / *ADDR
5513   Define a fast tracepoint at the given function, line, or address.
5514 
5515 * New expression syntax
5516 
5517   GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5518   GDB now parses 0b101010 identically with 42.
5519 
5520 * New options
5521 
5522 set follow-exec-mode new|same
5523 show follow-exec-mode
5524   Control whether GDB reuses the same inferior across an exec call or
5525   creates a new one.  This is useful to be able to restart the old
5526   executable after the inferior having done an exec call.
5527 
5528 set default-collect EXPR, ...
5529 show default-collect
5530    Define a list of expressions to be collected at each tracepoint.
5531    This is a useful way to ensure essential items are not overlooked,
5532    such as registers or a critical global variable.
5533 
5534 set disconnected-tracing
5535 show disconnected-tracing
5536    If set to 1, the target is instructed to continue tracing if it
5537    loses its connection to GDB.  If 0, the target is to stop tracing
5538    upon disconnection.
5539 
5540 set circular-trace-buffer
5541 show circular-trace-buffer
5542    If set to on, the target is instructed to use a circular trace buffer
5543    and discard the oldest trace frames instead of stopping the trace due
5544    to a full trace buffer.  If set to off, the trace stops when the buffer
5545    fills up.  Some targets may not support this.
5546 
5547 set script-extension off|soft|strict
5548 show script-extension
5549    If set to "off", the debugger does not perform any script language
5550    recognition, and all sourced files are assumed to be GDB scripts.
5551    If set to "soft" (the default), files are sourced according to
5552    filename extension, falling back to GDB scripts if the first
5553    evaluation failed.
5554    If set to "strict", files are sourced according to filename extension.
5555 
5556 set ada trust-PAD-over-XVS on|off
5557 show ada trust-PAD-over-XVS
5558    If off, activate a workaround against a bug in the debugging information
5559    generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5560    the GCC sources for more information about the GNAT encoding and
5561    PAD types in particular).  It is always safe to set this option to
5562    off, but this introduces a slight performance penalty.  The default
5563    is on.
5564 
5565 * Python API Improvements
5566 
5567   ** GDB provides the new class gdb.LazyString.  This is useful in
5568      some pretty-printing cases.  The new method gdb.Value.lazy_string
5569      provides a simple way to create objects of this type.
5570 
5571   ** The fields returned by gdb.Type.fields now have an
5572      `is_base_class' attribute.
5573 
5574   ** The new method gdb.Type.range returns the range of an array type.
5575 
5576   ** The new method gdb.parse_and_eval can be used to parse and
5577      evaluate an expression.
5578 
5579 * New remote packets
5580 
5581 QTDV
5582    Define a trace state variable.
5583 
5584 qTV
5585    Get the current value of a trace state variable.
5586 
5587 QTDisconnected
5588    Set desired tracing behavior upon disconnection.
5589 
5590 QTBuffer:circular
5591    Set the trace buffer to be linear or circular.
5592 
5593 qTfP, qTsP
5594    Get data about the tracepoints currently in use.
5595 
5596 * Bug fixes
5597 
5598 Process record now works correctly with hardware watchpoints.
5599 
5600 Multiple bug fixes have been made to the mips-irix port, making it
5601 much more reliable. In particular:
5602   - Debugging threaded applications is now possible again.  Previously,
5603     GDB would hang while starting the program, or while waiting for
5604     the program to stop at a breakpoint.
5605   - Attaching to a running process no longer hangs.
5606   - An error occurring while loading a core file has been fixed.
5607   - Changing the value of the PC register now works again.  This fixes
5608     problems observed when using the "jump" command, or when calling
5609     a function from GDB, or even when assigning a new value to $pc.
5610   - With the "finish" and "return" commands, the return value for functions
5611     returning a small array is now correctly printed.
5612   - It is now possible to break on shared library code which gets executed
5613     during a shared library init phase (code executed while executing
5614     their .init section).  Previously, the breakpoint would have no effect.
5615   - GDB is now able to backtrace through the signal handler for
5616     non-threaded programs.
5617 
5618 PIE (Position Independent Executable) programs debugging is now supported.
5619 This includes debugging execution of PIC (Position Independent Code) shared
5620 libraries although for that, it should be possible to run such libraries as an
5621 executable program.
5622 
5623 *** Changes in GDB 7.0
5624 
5625 * GDB now has an interface for JIT compilation.  Applications that
5626 dynamically generate code can create symbol files in memory and register
5627 them with GDB.  For users, the feature should work transparently, and
5628 for JIT developers, the interface is documented in the GDB manual in the
5629 "JIT Compilation Interface" chapter.
5630 
5631 * Tracepoints may now be conditional.  The syntax is as for
5632 breakpoints; either an "if" clause appended to the "trace" command,
5633 or the "condition" command is available.  GDB sends the condition to
5634 the target for evaluation using the same bytecode format as is used
5635 for tracepoint actions.
5636 
5637 * The disassemble command now supports: an optional /r modifier, print the
5638 raw instructions in hex as well as in symbolic form, and an optional /m
5639 modifier to print mixed source+assembly.
5640 
5641 * Process record and replay
5642 
5643   In a architecture environment that supports ``process record and
5644   replay'', ``process record and replay'' target can record a log of
5645   the process execution, and replay it with both forward and reverse
5646   execute commands.
5647 
5648 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5649 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5650 set execution-direction {forward|reverse}, for targets that support
5651 reverse execution.
5652 
5653 * GDB now supports hardware watchpoints on MIPS/Linux systems.  This
5654 feature is available with a native GDB running on kernel version
5655 2.6.28 or later.
5656 
5657 * GDB now has support for multi-byte and wide character sets on the
5658 target.  Strings whose character type is wchar_t, char16_t, or
5659 char32_t are now correctly printed.  GDB supports wide- and unicode-
5660 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5661 U"string" syntax.  And, GDB allows the "%ls" and "%lc" formats in
5662 `printf'.  This feature requires iconv to work properly; if your
5663 system does not have a working iconv, GDB can use GNU libiconv.  See
5664 the installation instructions for more information.
5665 
5666 * GDB now supports automatic retrieval of shared library files from
5667 remote targets.  To use this feature, specify a system root that begins
5668 with the `remote:' prefix, either via the `set sysroot' command or via
5669 the `--with-sysroot' configure-time option.
5670 
5671 * "info sharedlibrary" now takes an optional regex of libraries to show,
5672 and it now reports if a shared library has no debugging information.
5673 
5674 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5675 now complete on file names.
5676 
5677 * When completing in expressions, gdb will attempt to limit
5678 completions to allowable structure or union fields, where appropriate.
5679 For instance, consider:
5680 
5681     # struct example { int f1; double f2; };
5682     # struct example variable;
5683     (gdb) p variable.
5684 
5685 If the user types TAB at the end of this command line, the available
5686 completions will be "f1" and "f2".
5687 
5688 * Inlined functions are now supported.  They show up in backtraces, and
5689 the "step", "next", and "finish" commands handle them automatically.
5690 
5691 * GDB now supports the token-splicing (##) and stringification (#)
5692 operators when expanding macros.  It also supports variable-arity
5693 macros.
5694 
5695 * GDB now supports inspecting extra signal information, exported by
5696 the new $_siginfo convenience variable.  The feature is currently
5697 implemented on linux ARM, i386 and amd64.
5698 
5699 * GDB can now display the VFP floating point registers and NEON vector
5700 registers on ARM targets.  Both ARM GNU/Linux native GDB and gdbserver
5701 can provide these registers (requires Linux 2.6.30 or later).  Remote
5702 and simulator targets may also provide them.
5703 
5704 * New remote packets
5705 
5706 qSearch:memory:
5707   Search memory for a sequence of bytes.
5708 
5709 QStartNoAckMode
5710   Turn off `+'/`-' protocol acknowledgments to permit more efficient
5711   operation over reliable transport links.  Use of this packet is
5712   controlled by the `set remote noack-packet' command.
5713 
5714 vKill
5715   Kill the process with the specified process ID.  Use this in preference
5716   to `k' when multiprocess protocol extensions are supported.
5717 
5718 qXfer:osdata:read
5719   Obtains additional operating system information
5720 
5721 qXfer:siginfo:read
5722 qXfer:siginfo:write
5723   Read or write additional signal information.
5724 
5725 * Removed remote protocol undocumented extension
5726 
5727   An undocumented extension to the remote protocol's `S' stop reply
5728   packet that permitted the stub to pass a process id was removed.
5729   Remote servers should use the `T' stop reply packet instead.
5730 
5731 * GDB now supports multiple function calling conventions according to the
5732 DWARF-2 DW_AT_calling_convention function attribute.
5733   
5734 * The SH target utilizes the aforementioned change to distinguish between gcc
5735 and Renesas calling convention.  It also adds the new CLI commands
5736 `set/show sh calling-convention'.
5737 
5738 * GDB can now read compressed debug sections, as produced by GNU gold
5739 with the --compress-debug-sections=zlib flag.
5740 
5741 * 64-bit core files are now supported on AIX.
5742 
5743 * Thread switching is now supported on Tru64.
5744 
5745 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5746 which will be allocated using malloc later in program execution.
5747 
5748 * The qXfer:libraries:read remote protocol packet now allows passing a
5749 list of section offsets.
5750 
5751 * On GNU/Linux, GDB can now attach to stopped processes.  Several race
5752 conditions handling signals delivered during attach or thread creation
5753 have also been fixed.
5754 
5755 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5756 From the user's standpoint, all unqualified instances of True and False
5757 are treated as the standard definitions, regardless of context.
5758 
5759 * GDB now parses C++ symbol and type names more flexibly.  For
5760 example, given:
5761 
5762    template<typename T> class C { };
5763    C<char const *> c;
5764 
5765 GDB will now correctly handle all of:
5766 
5767    ptype C<char const *>
5768    ptype C<char const*>
5769    ptype C<const char *>
5770    ptype C<const char*>
5771 
5772 * New features in the GDB remote stub, gdbserver
5773 
5774   - The "--wrapper" command-line argument tells gdbserver to use a
5775   wrapper program to launch programs for debugging.
5776 
5777   - On PowerPC and S/390 targets, it is now possible to use a single
5778   gdbserver executable to debug both 32-bit and 64-bit programs.
5779   (This requires gdbserver itself to be built as a 64-bit executable.)
5780 
5781   - gdbserver uses the new noack protocol mode for TCP connections to
5782   reduce communications latency, if also supported and enabled in GDB.
5783 
5784   - Support for the sparc64-linux-gnu target is now included in
5785   gdbserver.
5786 
5787   - The amd64-linux build of gdbserver now supports debugging both
5788     32-bit and 64-bit programs.
5789 
5790   - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5791     now support hardware watchpoints, and will use them automatically
5792     as appropriate.
5793 
5794 * Python scripting
5795 
5796   GDB now has support for scripting using Python.  Whether this is
5797   available is determined at configure time.
5798 
5799   New GDB commands can now be written in Python.
5800 
5801 * Ada tasking support
5802 
5803   Ada tasks can now be inspected in GDB. The following commands have
5804   been introduced:
5805 
5806     info tasks
5807       Print the list of Ada tasks.
5808     info task N
5809       Print detailed information about task number N.
5810     task
5811       Print the task number of the current task.
5812     task N
5813       Switch the context of debugging to task number N.
5814 
5815 * Support for user-defined prefixed commands.  The "define" command can
5816 add new commands to existing prefixes, e.g. "target".
5817 
5818 * Multi-inferior, multi-process debugging.
5819 
5820   GDB now has generalized support for multi-inferior debugging.  See
5821   "Debugging Multiple Inferiors" in the manual for more information.
5822   Although availability still depends on target support, the command
5823   set is more uniform now.  The GNU/Linux specific multi-forks support
5824   has been migrated to this new framework.  This implied some user
5825   visible changes; see "New commands" and also "Removed commands"
5826   below.
5827 
5828 * Target descriptions can now describe the target OS ABI.  See the
5829 "Target Description Format" section in the user manual for more
5830 information.
5831 
5832 * Target descriptions can now describe "compatible" architectures
5833 to indicate that the target can execute applications for a different
5834 architecture in addition to those for the main target architecture.
5835 See the "Target Description Format" section in the user manual for
5836 more information.
5837 
5838 * Multi-architecture debugging.
5839 
5840   GDB now includes general supports for debugging applications on
5841   hybrid systems that use more than one single processor architecture
5842   at the same time.  Each such hybrid architecture still requires
5843   specific support to be added.  The only hybrid architecture supported
5844   in this version of GDB is the Cell Broadband Engine.
5845 
5846 * GDB now supports integrated debugging of Cell/B.E. applications that
5847 use both the PPU and SPU architectures.  To enable support for hybrid
5848 Cell/B.E. debugging, you need to configure GDB to support both the
5849 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5850 --enable-targets configure option.
5851 
5852 * Non-stop mode debugging.
5853 
5854   For some targets, GDB now supports an optional mode of operation in
5855   which you can examine stopped threads while other threads continue
5856   to execute freely.  This is referred to as non-stop mode, with the
5857   old mode referred to as all-stop mode.  See the "Non-Stop Mode"
5858   section in the user manual for more information.
5859 
5860   To be able to support remote non-stop debugging, a remote stub needs
5861   to implement the non-stop mode remote protocol extensions, as
5862   described in the "Remote Non-Stop" section of the user manual.  The
5863   GDB remote stub, gdbserver, has been adjusted to support these
5864   extensions on linux targets.
5865 
5866 * New commands (for set/show, see "New options" below)
5867 
5868 catch syscall [NAME(S) | NUMBER(S)]
5869   Catch system calls.  Arguments, which should be names of system
5870   calls or their numbers, mean catch only those syscalls.  Without
5871   arguments, every syscall will be caught.  When the inferior issues
5872   any of the specified syscalls, GDB will stop and announce the system
5873   call, both when it is called and when its call returns.  This
5874   feature is currently available with a native GDB running on the
5875   Linux Kernel, under the following architectures: x86, x86_64,
5876   PowerPC and PowerPC64.
5877 
5878 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5879     val1 [, val2, ...]
5880   Search memory for a sequence of bytes.
5881 
5882 maint set python print-stack
5883 maint show python print-stack
5884   Show a stack trace when an error is encountered in a Python script.
5885 
5886 python [CODE]
5887   Invoke CODE by passing it to the Python interpreter.
5888 
5889 macro define
5890 macro list
5891 macro undef
5892   These allow macros to be defined, undefined, and listed
5893   interactively.
5894 
5895 info os processes
5896   Show operating system information about processes.
5897 
5898 info inferiors
5899   List the inferiors currently under GDB's control.
5900 
5901 inferior NUM
5902   Switch focus to inferior number NUM.
5903 
5904 detach inferior NUM
5905   Detach from inferior number NUM.
5906 
5907 kill inferior NUM
5908   Kill inferior number NUM.
5909 
5910 * New options
5911 
5912 set spu stop-on-load
5913 show spu stop-on-load
5914   Control whether to stop for new SPE threads during Cell/B.E. debugging.
5915 
5916 set spu auto-flush-cache
5917 show spu auto-flush-cache
5918   Control whether to automatically flush the software-managed cache
5919   during Cell/B.E. debugging.
5920 
5921 set sh calling-convention
5922 show sh calling-convention
5923   Control the calling convention used when calling SH target functions.
5924 
5925 set debug timestamp
5926 show debug timestamp
5927   Control display of timestamps with GDB debugging output.
5928 
5929 set disassemble-next-line
5930 show disassemble-next-line
5931   Control display of disassembled source lines or instructions when
5932   the debuggee stops.
5933 
5934 set remote noack-packet
5935 show remote noack-packet
5936   Set/show the use of remote protocol QStartNoAckMode packet.  See above
5937   under "New remote packets."
5938 
5939 set remote query-attached-packet
5940 show remote query-attached-packet
5941   Control use of remote protocol `qAttached' (query-attached) packet.
5942 
5943 set remote read-siginfo-object
5944 show remote read-siginfo-object
5945   Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5946   packet.
5947 
5948 set remote write-siginfo-object
5949 show remote write-siginfo-object
5950   Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5951   packet.
5952 
5953 set remote reverse-continue
5954 show remote reverse-continue
5955   Control use of remote protocol 'bc' (reverse-continue) packet.
5956 
5957 set remote reverse-step
5958 show remote reverse-step
5959   Control use of remote protocol 'bs' (reverse-step) packet.
5960 
5961 set displaced-stepping
5962 show displaced-stepping
5963   Control displaced stepping mode.  Displaced stepping is a way to
5964   single-step over breakpoints without removing them from the debuggee.
5965   Also known as "out-of-line single-stepping".
5966 
5967 set debug displaced
5968 show debug displaced
5969   Control display of debugging info for displaced stepping.
5970 
5971 maint set internal-error
5972 maint show internal-error
5973   Control what GDB does when an internal error is detected.
5974 
5975 maint set internal-warning
5976 maint show internal-warning
5977   Control what GDB does when an internal warning is detected.
5978 
5979 set exec-wrapper
5980 show exec-wrapper
5981 unset exec-wrapper
5982   Use a wrapper program to launch programs for debugging.
5983 
5984 set multiple-symbols (all|ask|cancel)
5985 show multiple-symbols
5986   The value of this variable can be changed to adjust the debugger behavior
5987   when an expression or a breakpoint location contains an ambiguous symbol
5988   name (an overloaded function name, for instance).
5989   
5990 set breakpoint always-inserted
5991 show breakpoint always-inserted
5992   Keep breakpoints always inserted in the target, as opposed to inserting
5993   them when resuming the target, and removing them when the target stops.
5994   This option can improve debugger performance on slow remote targets.
5995 
5996 set arm fallback-mode (arm|thumb|auto)
5997 show arm fallback-mode
5998 set arm force-mode (arm|thumb|auto)
5999 show arm force-mode
6000   These commands control how ARM GDB determines whether instructions
6001   are ARM or Thumb.  The default for both settings is auto, which uses
6002   the current CPSR value for instructions without symbols; previous
6003   versions of GDB behaved as if "set arm fallback-mode arm".
6004 
6005 set arm unwind-secure-frames
6006   Enable unwinding from Non-secure to Secure mode on Cortex-M with
6007   Security extension.
6008   This can trigger security exceptions when unwinding exception stacks.
6009 
6010 set disable-randomization
6011 show disable-randomization
6012   Standalone programs run with the virtual address space randomization enabled
6013   by default on some platforms.  This option keeps the addresses stable across
6014   multiple debugging sessions.
6015 
6016 set non-stop
6017 show non-stop
6018   Control whether other threads are stopped or not when some thread hits
6019   a breakpoint.
6020 
6021 set target-async
6022 show target-async
6023   Requests that asynchronous execution is enabled in the target, if available.
6024   In this case, it's possible to resume target in the background, and interact
6025   with GDB while the target is running.  "show target-async" displays the
6026   current state of asynchronous execution of the target.
6027 
6028 set target-wide-charset
6029 show target-wide-charset
6030   The target-wide-charset is the name of the character set that GDB
6031   uses when printing characters whose type is wchar_t.
6032 
6033 set tcp auto-retry (on|off)
6034 show tcp auto-retry
6035 set tcp connect-timeout
6036 show tcp connect-timeout
6037   These commands allow GDB to retry failed TCP connections to a remote stub
6038   with a specified timeout period; this is useful if the stub is launched
6039   in parallel with GDB but may not be ready to accept connections immediately.
6040 
6041 set libthread-db-search-path
6042 show libthread-db-search-path
6043   Control list of directories which GDB will search for appropriate
6044   libthread_db.
6045 
6046 set schedule-multiple (on|off)
6047 show schedule-multiple
6048   Allow GDB to resume all threads of all processes or only threads of
6049   the current process.
6050 
6051 set stack-cache
6052 show stack-cache
6053   Use more aggressive caching for accesses to the stack.  This improves
6054   performance of remote debugging (particularly backtraces) without
6055   affecting correctness.
6056 
6057 set interactive-mode (on|off|auto)
6058 show interactive-mode
6059   Control whether GDB runs in interactive mode (on) or not (off).
6060   When in interactive mode, GDB waits for the user to answer all
6061   queries.  Otherwise, GDB does not wait and assumes the default
6062   answer.  When set to auto (the default), GDB determines which
6063   mode to use based on the stdin settings.
6064 
6065 * Removed commands
6066 
6067 info forks
6068   For program forks, this is replaced by the new more generic `info
6069   inferiors' command.  To list checkpoints, you can still use the
6070   `info checkpoints' command, which was an alias for the `info forks'
6071   command.
6072 
6073 fork NUM
6074   Replaced by the new `inferior' command.  To switch between
6075   checkpoints, you can still use the `restart' command, which was an
6076   alias for the `fork' command.
6077 
6078 process PID
6079   This is removed, since some targets don't have a notion of
6080   processes.  To switch between processes, you can still use the
6081   `inferior' command using GDB's own inferior number.
6082 
6083 delete fork NUM
6084   For program forks, this is replaced by the new more generic `kill
6085   inferior' command.  To delete a checkpoint, you can still use the
6086   `delete checkpoint' command, which was an alias for the `delete
6087   fork' command.
6088 
6089 detach fork NUM
6090   For program forks, this is replaced by the new more generic `detach
6091   inferior' command.  To detach a checkpoint, you can still use the
6092   `detach checkpoint' command, which was an alias for the `detach
6093   fork' command.
6094 
6095 * New native configurations
6096 
6097 x86/x86_64 Darwin               i[34567]86-*-darwin*
6098 
6099 x86_64 MinGW                    x86_64-*-mingw*
6100 
6101 * New targets
6102 
6103 Lattice Mico32                  lm32-*
6104 x86 DICOS                       i[34567]86-*-dicos*
6105 x86_64 DICOS                    x86_64-*-dicos*
6106 S+core 3                        score-*-*
6107 
6108 * The GDB remote stub, gdbserver, now supports x86 Windows CE
6109   (mingw32ce) debugging.
6110 
6111 * Removed commands
6112 
6113 catch load
6114 catch unload
6115   These commands were actually not implemented on any target.
6116 
6117 *** Changes in GDB 6.8
6118 
6119 * New native configurations
6120 
6121 NetBSD/hppa                     hppa*-*netbsd*
6122 Xtensa GNU/Linux                xtensa*-*-linux*
6123 
6124 * New targets
6125 
6126 NetBSD/hppa                     hppa*-*-netbsd*
6127 Xtensa GNU/Linux                xtensa*-*-linux*
6128 
6129 * Change in command line behavior -- corefiles vs. process ids.
6130 
6131   When the '-p NUMBER' or '--pid NUMBER' options are used, and
6132   attaching to process NUMBER fails, GDB no longer attempts to open a
6133   core file named NUMBER.  Attaching to a program using the -c option
6134   is no longer supported.  Instead, use the '-p' or '--pid' options.
6135 
6136 * GDB can now be built as a native debugger for debugging Windows x86
6137 (mingw32) Portable Executable (PE) programs.
6138 
6139 * Pending breakpoints no longer change their number when their address
6140 is resolved.
6141 
6142 * GDB now supports breakpoints with multiple locations,
6143 including breakpoints on C++ constructors, inside C++ templates,
6144 and in inlined functions.
6145 
6146 * GDB's ability to debug optimized code has been improved.  GDB more
6147 accurately identifies function bodies and lexical blocks that occupy
6148 more than one contiguous range of addresses.
6149 
6150 * Target descriptions can now describe registers for PowerPC.
6151 
6152 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6153 registers on PowerPC targets.
6154 
6155 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6156 targets even when the libthread_db library is not available.
6157 
6158 * The GDB remote stub, gdbserver, now supports the new file transfer
6159 commands (remote put, remote get, and remote delete).
6160 
6161 * The GDB remote stub, gdbserver, now supports run and attach in
6162 extended-remote mode.
6163 
6164 * hppa*64*-*-hpux11* target broken
6165 The debugger is unable to start a program and fails with the following
6166 error: "Error trying to get information about dynamic linker".
6167 The gdb-6.7 release is also affected.
6168 
6169 * GDB now supports the --enable-targets= configure option to allow
6170 building a single GDB executable that supports multiple remote
6171 target architectures.
6172 
6173 * GDB now supports debugging C and C++ programs which use the
6174 Decimal Floating Point extension.  In addition, the PowerPC target
6175 now has a set of pseudo-registers to inspect decimal float values
6176 stored in two consecutive float registers.
6177 
6178 * The -break-insert MI command can optionally create pending
6179 breakpoints now.
6180 
6181 * Improved support for debugging Ada
6182 Many improvements to the Ada language support have been made.  These
6183 include:
6184     - Better support for Ada2005 interface types
6185     - Improved handling of arrays and slices in general
6186     - Better support for Taft-amendment types
6187     - The '{type} ADDRESS' expression is now allowed on the left hand-side
6188       of an assignment
6189     - Improved command completion in Ada
6190     - Several bug fixes
6191 
6192 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6193 process.
6194 
6195 * New commands
6196 
6197 set print frame-arguments (all|scalars|none)
6198 show print frame-arguments
6199   The value of this variable can be changed to control which argument
6200   values should be printed by the debugger when displaying a frame.
6201 
6202 remote put
6203 remote get
6204 remote delete
6205   Transfer files to and from a remote target, and delete remote files.
6206 
6207 * New MI commands
6208 
6209 -target-file-put
6210 -target-file-get
6211 -target-file-delete
6212   Transfer files to and from a remote target, and delete remote files.
6213 
6214 * New remote packets
6215 
6216 vFile:open:
6217 vFile:close:
6218 vFile:pread:
6219 vFile:pwrite:
6220 vFile:unlink:
6221   Open, close, read, write, and delete files on the remote system.
6222 
6223 vAttach
6224   Attach to an existing process on the remote system, in extended-remote
6225   mode.
6226 
6227 vRun
6228   Run a new process on the remote system, in extended-remote mode.
6229 
6230 *** Changes in GDB 6.7
6231 
6232 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb, 
6233 bfd, libiberty and opcodes, as revealed by static analysis donated by
6234 Coverity, Inc. (http://scan.coverity.com).
6235 
6236 * When looking up multiply-defined global symbols, GDB will now prefer the
6237 symbol definition in the current shared library if it was built using the
6238 -Bsymbolic linker option.
6239 
6240 * When the Text User Interface (TUI) is not configured, GDB will now
6241 recognize the -tui command-line option and print a message that the TUI
6242 is not supported.
6243 
6244 * The GDB remote stub, gdbserver, now has lower overhead for high 
6245 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6246 
6247 * GDB for MIPS targets now autodetects whether a remote target provides
6248 32-bit or 64-bit register values.
6249 
6250 * Support for C++ member pointers has been improved.
6251 
6252 * GDB now understands XML target descriptions, which specify the
6253 target's overall architecture.  GDB can read a description from
6254 a local file or over the remote serial protocol.
6255 
6256 * Vectors of single-byte data use a new integer type which is not
6257 automatically displayed as character or string data.
6258 
6259 * The /s format now works with the print command.  It displays
6260 arrays of single-byte integers and pointers to single-byte integers
6261 as strings.
6262 
6263 * Target descriptions can now describe target-specific registers,
6264 for architectures which have implemented the support (currently
6265 only ARM, M68K, and MIPS).
6266 
6267 * GDB and the GDB remote stub, gdbserver, now support the XScale
6268 iWMMXt coprocessor.
6269 
6270 * The GDB remote stub, gdbserver, has been updated to support
6271 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6272 has been rewritten to use the standard GDB remote protocol.
6273 
6274 * GDB can now step into C++ functions which are called through thunks.
6275 
6276 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6277 
6278 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6279 layout.  It also supports a TextSeg= and DataSeg= response when only
6280 segment base addresses (rather than offsets) are available.
6281 
6282 * The /i format now outputs any trailing branch delay slot instructions 
6283 immediately following the last instruction within the count specified.
6284 
6285 * The GDB remote protocol "T" stop reply packet now supports a
6286 "library" response.  Combined with the new "qXfer:libraries:read"
6287 packet, this response allows GDB to debug shared libraries on targets
6288 where the operating system manages the list of loaded libraries (e.g.
6289 Windows and SymbianOS).
6290 
6291 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6292 (DLLs) on Windows and Windows CE targets.
6293 
6294 * GDB now supports a faster verification that a .debug file matches its binary
6295 according to its build-id signature, if the signature is present.
6296 
6297 * New commands
6298 
6299 set remoteflow
6300 show remoteflow
6301   Enable or disable hardware flow control (RTS/CTS) on the serial port
6302   when debugging using remote targets.
6303 
6304 set mem inaccessible-by-default
6305 show mem inaccessible-by-default
6306   If the target supplies a memory map, for instance via the remote
6307   protocol's "qXfer:memory-map:read" packet, setting this variable
6308   prevents GDB from accessing memory outside the memory map.  This
6309   is useful for targets with memory mapped registers or which react
6310   badly to accesses of unmapped address space.
6311 
6312 set breakpoint auto-hw
6313 show breakpoint auto-hw
6314   If the target supplies a memory map, for instance via the remote
6315   protocol's "qXfer:memory-map:read" packet, setting this variable
6316   lets GDB use hardware breakpoints automatically for memory regions
6317   where it can not use software breakpoints.  This covers both the
6318   "break" command and internal breakpoints used for other commands
6319   including "next" and "finish".
6320 
6321 catch exception
6322 catch exception unhandled
6323   Stop the program execution when Ada exceptions are raised.
6324 
6325 catch assert
6326   Stop the program execution when an Ada assertion failed.
6327 
6328 set sysroot
6329 show sysroot
6330   Set an alternate system root for target files.  This is a more
6331   general version of "set solib-absolute-prefix", which is now
6332   an alias to "set sysroot".
6333 
6334 info spu
6335   Provide extended SPU facility status information.  This set of
6336   commands is available only when debugging the Cell/B.E. SPU
6337   architecture.
6338 
6339 * New native configurations
6340 
6341 OpenBSD/sh                      sh*-*openbsd*
6342 
6343 set tdesc filename
6344 unset tdesc filename
6345 show tdesc filename
6346   Use the specified local file as an XML target description, and do
6347   not query the target for its built-in description.
6348 
6349 * New targets
6350 
6351 OpenBSD/sh                      sh*-*-openbsd*
6352 MIPS64 GNU/Linux (gdbserver)    mips64-linux-gnu
6353 Toshiba Media Processor         mep-elf
6354 
6355 * New remote packets
6356 
6357 QPassSignals:
6358   Ignore the specified signals; pass them directly to the debugged program
6359   without stopping other threads or reporting them to GDB.
6360 
6361 qXfer:features:read:
6362   Read an XML target description from the target, which describes its
6363   features.
6364 
6365 qXfer:spu:read:
6366 qXfer:spu:write:
6367   Read or write contents of an spufs file on the target system.  These
6368   packets are available only on the Cell/B.E. SPU architecture.
6369 
6370 qXfer:libraries:read:
6371   Report the loaded shared libraries.  Combined with new "T" packet
6372