What has changed in GDB?
(Organized release by release)
-*** Changes since GDB 12
+*** Changes since GDB 13
+
+* GDB now recognizes the NO_COLOR environment variable and disables
+ styling according to the spec. See https://no-color.org/.
+ Styling can be re-enabled with "set style enabled on".
+
+* The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
+ has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
+ string.
+
+* GDB now has some support for integer types larger than 64 bits.
+
+* Removed targets and native configurations
+
+ GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
+ AIX version is now AIX 7.1.
+
+* Multi-target feature configuration
+
+ GDB now supports the individual configuration of remote targets' feature
+ sets. Based on the current selection of a target, the commands 'set remote
+ <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
+ configure a target's feature packet and to display its configuration,
+ respectively.
+
+ The individual packet sizes can be configured and shown using the commands
+ ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
+ ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
+ ** 'show remote memory-read-packet-size'
+ ** 'show remote memory-write-packet-size'.
+
+ The configuration of the packet itself, as well as the size of a memory-read
+ or memory-write packet applies to the currently selected target (if
+ available). If no target is selected, it applies to future remote
+ connections. Similarly, the show commands print the configuration of the
+ currently selected target. If no remote target is selected, the default
+ configuration for future connections is shown.
+
+* MI version 1 has been removed.
+
+* GDB has initial built-in support for the Debugger Adapter Protocol.
+ This support requires that GDB be built with Python scripting
+ enabled.
+
+* For the break command, multiple uses of the 'thread' or 'task'
+ keywords will now give an error instead of just using the thread or
+ task id from the last instance of the keyword. E.g.:
+ break foo thread 1 thread 2
+ will now give an error rather than using 'thread 2'.
+
+* For the watch command, multiple uses of the 'task' keyword will now
+ give an error instead of just using the task id from the last
+ instance of the keyword. E.g.:
+ watch my_var task 1 task 2
+ will now give an error rather than using 'task 2'. The 'thread'
+ keyword already gave an error when used multiple times with the
+ watch command, this remains unchanged.
+
+* The 'set print elements' setting now helps when printing large arrays.
+ If an array would otherwise exceed max-value-size, but 'print elements'
+ is set such that the size of elements to print is less than or equal
+ to 'max-value-size', GDB will now still print the array, however only
+ 'max-value-size' worth of data will be added into the value history.
+
+* For both the break and watch commands, it is now invalid to use both
+ the 'thread' and 'task' keywords within the same command. For
+ example the following commnds will now give an error:
+ break foo thread 1 task 1
+ watch var thread 2 task 3
+
+* The printf command now accepts a '%V' output format which will
+ format an expression just as the 'print' command would. Print
+ options can be placed withing '[...]' after the '%V' to modify how
+ the value is printed. E.g:
+ printf "%V", some_array
+ printf "%V[-array-indexes on]", some_array
+ will print the array without, or with array indexes included, just
+ as the array would be printed by the 'print' command. This
+ functionality is also available for dprintf when dprintf-style is
+ 'gdb'.
+
+* When the printf command requires a string to be fetched from the
+ inferior, GDB now uses the existing 'max-value-size' setting to the
+ limit the memory allocated within GDB. The default 'max-value-size'
+ is 64k. To print longer strings you should increase
+ 'max-value-size'.
+
+* The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
+
+* The Ada 2022 target name symbol ('@') is now supported by the Ada
+ expression parser.
+
+* The 'list' command now accepts '.' as an argument, which tells GDB to
+ print the location around the point of execution within the current frame.
+ If the inferior hasn't started yet, the command will print around the
+ beginning of the 'main' function.
+
+* Using the 'list' command with no arguments in a situation where the
+ command would attempt to list past the end of the file now warns the
+ user that the end of file has been reached, refers the user to the
+ newly added '.' argument
+
+* Breakpoints can now be inferior-specific. This is similar to the
+ existing thread-specific breakpoint support. Breakpoint conditions
+ can include the 'inferior' keyword followed by an inferior id (as
+ displayed in the 'info inferiors' output). It is invalid to use the
+ 'inferior' keyword with either the 'thread' or 'task' keywords when
+ creating a breakpoint.
+
+* New commands
+
+set debug breakpoint on|off
+ show debug breakpoint
+ Print additional debug messages about breakpoint insertion and removal.
+
+maintenance print record-instruction [ N ]
+ Print the recorded information for a given instruction. If N is not given
+ prints how GDB would undo the last instruction executed. If N is negative,
+ prints how GDB would undo the N-th previous instruction, and if N is
+ positive, it prints how GDB will redo the N-th following instruction.
+
+maintenance info frame-unwinders
+ List the frame unwinders currently in effect, starting with the highest
+ priority.
+
+maintenance wait-for-index-cache
+ Wait until all pending writes to the index cache have completed.
+
+set always-read-ctf on|off
+show always-read-ctf
+ When off, CTF is only read if DWARF is not present. When on, CTF is
+ read regardless of whether DWARF is present. Off by default.
+
+info main
+ Get main symbol to identify entry point into program.
+
+set tui mouse-events [on|off]
+show tui mouse-events
+ When on (default), mouse clicks control the TUI and can be accessed by
+ Python extensions. When off, mouse clicks are handled by the terminal,
+ enabling terminal-native text selection.
+
+* New convenience function "$_shell", to execute a shell command and
+ return the result. This lets you run shell commands in expressions.
+ Some examples:
+
+ (gdb) p $_shell("true")
+ $1 = 0
+ (gdb) p $_shell("false")
+ $2 = 1
+ (gdb) break func if $_shell("some command") == 0
+
+* MI changes
+
+** mi now reports 'no-history' as a stop reason when hitting the end of the
+ reverse execution history.
+
+** When creating a thread-specific breakpoint using the '-p' option,
+ the -break-insert command would report the 'thread' field twice in
+ the reply. The content of both fields was always identical. This
+ has now been fixed; the 'thread' field will be reported just once
+ for thread-specific breakpoints, or not at all for breakpoints
+ without a thread restriction. The same is also true for the 'task'
+ field of an Ada task-specific breakpoint.
+
+** It is no longer possible to create a thread-specific breakpoint for
+ a thread that doesn't exist using '-break-insert -p ID'. Creating
+ breakpoints for non-existent threads is not allowed when using the
+ CLI, that the MI allowed it was a long standing bug, which has now
+ been fixed.
+
+** The '--simple-values' argument to the '-stack-list-arguments',
+ '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
+ commands now takes reference types into account: that is, a value is now
+ considered simple if it is neither an array, structure, or union, nor a
+ reference to an array, structure, or union. (Previously all references were
+ considered simple.) Support for this feature can be verified by using the
+ '-list-features' command, which should contain "simple-values-ref-types".
+
+** The -break-insert command now accepts a '-g thread-group-id' option
+ to allow for the creation of inferior-specific breakpoints.
+
+** The bkpt tuple, which appears in breakpoint-created notifications,
+ and in the result of the -break-insert command can now include an
+ optional 'inferior' field for both the main breakpoint, and each
+ location, when the breakpoint is inferior-specific.
+
+* Python API
+
+ ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
+
+ ** The gdb.unwinder.Unwinder.name attribute is now read-only.
+
+ ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
+ now be of type 'str' otherwise a TypeError will be raised.
+
+ ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
+ values of type 'bool'. Changing this attribute will now
+ invalidate GDB's frame-cache, which means GDB will need to
+ rebuild its frame-cache when next required - either with, or
+ without the particular unwinder, depending on how 'enabled' was
+ changed.
+
+ ** New methods added to the gdb.PendingFrame class. These methods
+ have the same behaviour as the corresponding methods on
+ gdb.Frame. The new methods are:
+
+ - gdb.PendingFrame.name: Return the name for the frame's
+ function, or None.
+ - gdb.PendingFrame.is_valid: Return True if the pending frame
+ object is valid.
+ - gdb.PendingFrame.pc: Return the $pc register value for this
+ frame.
+ - gdb.PendingFrame.language: Return a string containing the
+ language for this frame, or None.
+ - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
+ object for the current location within the pending frame, or
+ None.
+ - gdb.PendingFrame.block: Return a gdb.Block for the current
+ pending frame, or None.
+ - gdb.PendingFrame.function: Return a gdb.Symbol for the
+ current pending frame, or None.
+
+ ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
+ now use either an integer or a gdb.Value object for each of its
+ 'sp', 'pc', and 'special' attributes.
+
+ ** A new class gdb.unwinder.FrameId has been added. Instances of
+ this class are constructed with 'sp' (stack-pointer) and 'pc'
+ (program-counter) values, and can be used as the frame-id when
+ calling gdb.PendingFrame.create_unwind_info.
+
+ ** It is now no longer possible to sub-class the
+ gdb.disassembler.DisassemblerResult type.
+
+ ** The Disassembler API from the gdb.disassembler module has been
+ extended to include styling support:
+
+ - The DisassemblerResult class can now be initialized with a list
+ of parts. Each part represents part of the disassembled
+ instruction along with the associated style information. This
+ list of parts can be accessed with the new
+ DisassemblerResult.parts property.
+
+ - New constants gdb.disassembler.STYLE_* representing all the
+ different styles part of an instruction might have.
+
+ - New methods DisassembleInfo.text_part and
+ DisassembleInfo.address_part which are used to create the new
+ styled parts of a disassembled instruction.
+
+ - Changes are backwards compatible, the older API can still be
+ used to disassemble instructions without styling.
+
+ ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
+ GDB/MI command and returns the output as a Python dictionary.
+
+ ** New function gdb.block_signals(). This returns a context manager
+ that blocks any signals that GDB needs to handle itself.
+
+ ** New class gdb.Thread. This is a subclass of threading.Thread
+ that calls gdb.block_signals in its "start" method.
+
+ ** gdb.parse_and_eval now has a new "global_context" parameter.
+ This can be used to request that the parse only examine global
+ symbols.
+
+ ** gdb.Inferior now has a new "arguments" attribute. This holds the
+ command-line arguments to the inferior, if known.
+
+ ** gdb.Inferior now has a new "main_name" attribute. This holds the
+ name of the inferior's "main", if known.
+
+ ** gdb.Inferior now has new methods "clear_env", "set_env", and
+ "unset_env". These can be used to modify the inferior's
+ environment before it is started.
+
+ ** gdb.Value now has the 'assign' method.
+
+ ** gdb.Value now has the 'to_array' method. This converts an
+ array-like Value to an array.
+
+ ** gdb.Progspace now has the new method "objfile_for_address". This
+ returns the gdb.Objfile, if any, that covers a given address.
+
+ ** gdb.Breakpoint now has an "inferior" attribute. If the
+ Breakpoint object is inferior specific then this attribute holds
+ the inferior-id (an integer). If the Breakpoint object is not
+ inferior specific, then this field contains None. This field can
+ be written too.
+
+ ** gdb.Type now has the "is_array_like" and "is_string_like"
+ methods. These reflect GDB's internal idea of whether a type
+ might be array- or string-like, even if they do not have the
+ corresponding type code.
+
+ ** gdb.ValuePrinter is a new class that can be used as the base
+ class for the result of applying a pretty-printer. As a base
+ class, it signals to gdb that the printer may implement new
+ pretty-printer methods.
+
+ ** New attribute Progspace.symbol_file. This attribute holds the
+ gdb.Objfile that corresponds to Progspace.filename (when
+ Progspace.filename is not None), otherwise, this attribute is
+ itself None.
+
+ ** New attribute Progspace.executable_filename. This attribute
+ holds a string containing a file name set by the "exec-file" or
+ "file" commands, or None if no executable file is set. This
+ isn't the exact string passed by the user to these commands; the
+ file name will have been partially resolved to an absolute file
+ name.
+
+ ** A new executable_changed event registry is available. This event
+ emits ExecutableChangedEvent objects, which have 'progspace' (a
+ gdb.Progspace) and 'reload' (a Boolean) attributes. This event
+ is emitted when gdb.Progspace.executable_filename changes.
+
+ ** New event registries gdb.events.new_progspace and
+ gdb.events.free_progspace, these emit NewProgspaceEvent and
+ FreeProgspaceEvent event types respectively. Both of these event
+ types have a single 'progspace' attribute, which is the
+ gdb.Progspace that is either being added to GDB, or removed from
+ GDB.
+
+*** Changes in GDB 13
+
+* MI version 1 is deprecated, and will be removed in GDB 14.
+
+* GDB now supports dumping memory tag data for AArch64 MTE. It also supports
+ reading memory tag data for AArch64 MTE from core files generated by
+ the gcore command or the Linux kernel.
+
+ When a process uses memory-mapped pages protected by memory tags (for
+ example, AArch64 MTE), this additional information will be recorded in
+ the core file in the event of a crash or if GDB generates a core file
+ from the current process state. GDB will show this additional information
+ automatically, or through one of the memory-tag subcommands.
+
+* "info breakpoints" now displays enabled breakpoint locations of
+ disabled breakpoints as in the "y-" state. For example:
+
+ (gdb) info breakpoints
+ Num Type Disp Enb Address What
+ 1 breakpoint keep n <MULTIPLE>
+ 1.1 y- 0x00000000000011b6 in ...
+ 1.2 y- 0x00000000000011c2 in ...
+ 1.3 n 0x00000000000011ce in ...
+
+* Support for Thread Local Storage (TLS) variables on FreeBSD arm and
+ aarch64 architectures.
* GDB now supports hardware watchpoints on FreeBSD/Aarch64.
emit to indicate where a breakpoint should be placed to break in a function
past its prologue.
+* Completion now also offers "NUMBER" for "set" commands that accept
+ a numeric argument and the "unlimited" keyword. For example:
+
+ (gdb) set width <TAB>
+ NUMBER unlimited
+
+ and consequently:
+
+ (gdb) complete set width
+ set width NUMBER
+ set width unlimited
+
+* Disassembler styling using libopcodes. GDB now supports
+ disassembler styling using libopcodes. This is only available for
+ some targets (currently x86 and RISC-V). For unsupported targets
+ Python Pygments is still used. For supported targets, libopcodes
+ styling is used by default.
+
+* The Windows native target now supports target async.
+
+* gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
+
+* The format of 'disassemble /r' and 'record instruction-history /r'
+ has changed. The instruction bytes could now be grouped together,
+ and displayed in the endianness of the instruction. This is the
+ same layout as used by GNU objdump when disassembling.
+
+ There is now 'disassemble /b' and 'record instruction-history /b'
+ which will always display the instructions bytes one at a time in
+ memory order, that is, the byte at the lowest address first.
+
+ For both /r and /b GDB is now better at using whitespace in order to
+ align the disassembled instruction text.
+
+* The TUI no longer styles the source and assembly code highlighted by
+ the current position indicator by default. You can however
+ re-enable styling using the new "set style tui-current-position"
+ command.
+
+* New convenience variable $_inferior_thread_count contains the number
+ of live threads in the current inferior.
+
+* When a breakpoint with multiple code locations is hit, GDB now prints
+ the code location using the syntax <breakpoint_number>.<location_number>
+ such as in:
+ Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
+
+* When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
+ and $_hit_locno to the hit breakpoint number and code location number.
+ This allows to disable the last hit breakpoint using
+ (gdb) disable $_hit_bpnum
+ or disable only the specific breakpoint code location using
+ (gdb) disable $_hit_bpnum.$_hit_locno
+ These commands can be used inside the command list of a breakpoint to
+ automatically disable the just encountered breakpoint (or the just
+ encountered specific breakpoint code location).
+ When a breakpoint has only one location, $_hit_locno is set to 1 so that
+ (gdb) disable $_hit_bpnum.$_hit_locno
+ and
+ (gdb) disable $_hit_bpnum
+ are both disabling the breakpoint.
+
* New commands
maintenance set ignore-prologue-end-flag on|off
used to force GDB to use prologue analyzers if the line-table is constructed
from erroneous debug information.
+set print nibbles [on|off]
+show print nibbles
+ This controls whether the 'print/t' command will display binary values
+ in groups of four bits, known as "nibbles". The default is 'off'.
+
+maintenance set libopcodes-styling on|off
+maintenance show libopcodes-styling
+ These can be used to force off libopcodes based styling, the Python
+ Pygments styling will then be used instead.
+
+set style disassembler comment
+show style disassembler comment
+set style disassembler immediate
+show style disassembler immediate
+set style disassembler mnemonic
+show style disassembler mnemonic
+set style disassembler register
+show style disassembler register
+set style disassembler address
+show style disassembler address
+set style disassembler symbol
+show style disassembler symbol
+ For targets that support libopcodes based styling, these settings
+ control how various aspects of the disassembler output are styled.
+ The 'disassembler address' and 'disassembler symbol' styles are
+ aliases for the 'address' and 'function' styles respectively.
+
+maintenance print frame-id [ LEVEL ]
+ Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
+ not given, then print the frame-id for the currently selected frame.
+
+set debug infcall on|off
+show debug infcall
+ Print additional debug messages about inferior function calls.
+
+set debug solib on|off
+show debug solib
+ Print additional debug messages about shared library handling.
+
+set style tui-current-position [on|off]
+ Whether to style the source and assembly code highlighted by the
+ TUI's current position indicator. The default is off.
+
+set print characters LIMIT
+show print characters
+ This new setting is like 'set print elements', but controls how many
+ characters of a string are printed. This functionality used to be
+ covered by 'set print elements', but it can be controlled separately
+ now. LIMIT can be set to a numerical value to request that particular
+ character count, to 'unlimited' to print all characters of a string,
+ or to 'elements', which is also the default, to follow the setting of
+ 'set print elements' as it used to be.
+
+print -characters LIMIT
+ This new option to the 'print' command has the same effect as a temporary
+ use of 'set print characters'.
+
* Changed commands
+document user-defined
+ It is now possible to document user-defined aliases.
+ When a user-defined alias is documented, the help and apropos commands
+ use the provided documentation instead of the documentation of the
+ aliased command.
+ Documenting a user-defined alias is particularly useful when the alias
+ is a set of nested 'with' commands to avoid showing the help of
+ the with command for an alias that will in fact launch the
+ last command given in the nested commands.
+
maintenance info line-table
Add a PROLOGUE-END column to the output which indicates that an
entry corresponds to an address where a breakpoint should be placed
to be at the first instruction past a function's prologue.
+* Removed commands
+
+set debug aix-solib on|off
+show debug aix-solib
+set debug solib-frv on|off
+show debug solib-frv
+ Removed in favor of "set/show debug solib".
+
+maintenance info program-spaces
+ This command now includes a 'Core File' column which indicates the
+ name of the core file associated with each program space.
+
+* New targets
+
+GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
+
+GNU/Linux/CSKY (gdbserver) csky*-*linux*
+
+AMDGPU amdgcn-*-*
+
+* MI changes
+
+ ** The async record stating the stopped reason 'breakpoint-hit' now
+ contains an optional field locno giving the code location number
+ when the breakpoint has multiple code locations.
+
* Python API
+ ** GDB will now reformat the doc string for gdb.Command and
+ gdb.Parameter sub-classes to remove unnecessary leading
+ whitespace from each line before using the string as the help
+ output.
+
** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
that formats ADDRESS as 'address <symbol+offset>', where symbol is
looked up in PROGSPACE, and ARCHITECTURE is used to format address.
This is the same format that GDB uses when printing address, symbol,
and offset information from the disassembler.
+ ** New function gdb.current_language that returns the name of the
+ current language. Unlike gdb.parameter('language'), this will
+ never return 'auto'.
+
+ ** New method gdb.Frame.language that returns the name of the
+ frame's language.
+
+ ** New Python API for wrapping GDB's disassembler:
+
+ - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
+ DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
+ ARCH is either None or a string containing a bfd architecture
+ name. DISASSEMBLER is registered as a disassembler for
+ architecture ARCH, or for all architectures if ARCH is None.
+ The previous disassembler registered for ARCH is returned, this
+ can be None if no previous disassembler was registered.
+
+ - gdb.disassembler.Disassembler is the class from which all
+ disassemblers should inherit. Its constructor takes a string,
+ a name for the disassembler, which is currently only used in
+ some debug output. Sub-classes should override the __call__
+ method to perform disassembly, invoking __call__ on this base
+ class will raise an exception.
+
+ - gdb.disassembler.DisassembleInfo is the class used to describe
+ a single disassembly request from GDB. An instance of this
+ class is passed to the __call__ method of
+ gdb.disassembler.Disassembler and has the following read-only
+ attributes: 'address', and 'architecture', as well as the
+ following method: 'read_memory'.
+
+ - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
+ calls GDB's builtin disassembler on INFO, which is a
+ gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
+ optional, its default value is None. If MEMORY_SOURCE is not
+ None then it must be an object that has a 'read_memory' method.
+
+ - gdb.disassembler.DisassemblerResult is a class that can be used
+ to wrap the result of a call to a Disassembler. It has
+ read-only attributes 'length' and 'string'.
+
+ ** gdb.Objfile now has an attribute named "is_file". This is True
+ if the objfile comes from a file, and False otherwise.
+
+ ** New function gdb.print_options that returns a dictionary of the
+ prevailing print options, in the form accepted by
+ gdb.Value.format_string.
+
+ ** gdb.Value.format_string now uses the format provided by 'print',
+ if it is called during a 'print' or other similar operation.
+
+ ** gdb.Value.format_string now accepts the 'summary' keyword. This
+ can be used to request a shorter representation of a value, the
+ way that 'set print frame-arguments scalars' does.
+
+ ** New Python type gdb.BreakpointLocation.
+ The new attribute 'locations' of gdb.Breakpoint returns a list of
+ gdb.BreakpointLocation objects specifying the locations where the
+ breakpoint is inserted into the debuggee.
+
+ ** The gdb.register_window_type method now restricts the set of
+ acceptable window names. The first character of a window's name
+ must start with a character in the set [a-zA-Z], every subsequent
+ character of a window's name must be in the set [-_.a-zA-Z0-9].
+
+* New features in the GDB remote stub, GDBserver
+
+ ** GDBserver is now supported on LoongArch GNU/Linux.
+
+ ** GDBserver is now supported on CSKY GNU/Linux.
+
+* LoongArch floating-point support
+
+GDB now supports floating-point on LoongArch GNU/Linux.
+
+* AMD GPU ROCm debugging support
+
+GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
+platform.
+
*** Changes in GDB 12
* DBX mode is deprecated, and will be removed in GDB 13
Python 2. From GDB 13, it will only be possible to build GDB itself
with Python 3 support.
+* The disable-randomization setting now works on Windows.
+
* Improved C++ template support
GDB now treats functions/types involving C++ templates like it does function
option, which causes the new inferior to start without a
connection.
+ ** The default version of the MI interpreter is now 4 (-i=mi4).
+
+ ** The "script" field in breakpoint output (which is syntactically
+ incorrect in MI 3 and below) has changed in MI 4 to become a list.
+ This affects the following commands and events:
+
+ - -break-insert
+ - -break-info
+ - =breakpoint-created
+ - =breakpoint-modified
+
+ The -fix-breakpoint-script-output command can be used to enable
+ this behavior with previous MI versions.
+
* New targets
GNU/Linux/LoongArch loongarch*-*-linux*
projects / binutils-gdb.git / blobdiff