What has changed in GDB?
(Organized release by release)
-*** Changes since GDB 8.2
+*** Changes since GDB 9
+
+* Help and apropos commands will now show the documentation of a
+ command only once, even if that command has one or more aliases.
+ These commands now show the command name, then all of its aliases,
+ and finally the description of the command.
+
+* 'help aliases' now shows only the user defined aliases. GDB predefined
+ aliases are shown together with their aliased command.
+
+* GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
+ debugging information as well as source code.
+
+ When built with debuginfod, GDB can automatically query debuginfod
+ servers for the separate debug files and source code of the executable
+ being debugged.
+
+ To build GDB with debuginfod, pass --with-debuginfod to configure (this
+ requires libdebuginfod, the debuginfod client library).
+
+ debuginfod is distributed with elfutils, starting with version 0.178.
+
+ You can get the latest version from https://sourceware.org/elfutils.
+
+* New features in the GDB remote stub, GDBserver
+
+ ** GDBserver is now supported on RISC-V GNU/Linux.
+
+* Debugging MS-Windows processes now sets $_exitsignal when the
+ inferior is terminated by a signal, instead of setting $_exitcode.
+
+* Multithreaded symbol loading has now been enabled by default on systems
+ that support it (see entry for GDB 9, below), providing faster
+ performance for programs with many symbols.
+
+* The $_siginfo convenience variable now also works on Windows targets,
+ and will display the EXCEPTION_RECORD of the last handled exception.
+
+* TUI windows can now be arranged horizontally.
+
+* The command history filename can now be set to the empty string
+ either using 'set history filename' or by setting 'GDBHISTFILE=' in
+ the environment. The effect of setting this filename to the empty
+ string is that GDB will not try to load any previous command
+ history.
+
+* On Windows targets, it is now possible to debug 32-bit programs with a
+ 64-bit GDB.
+
+* New commands
+
+set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
+show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
+ Set or show the option 'exec-file-mismatch'. When GDB attaches to a
+ running process, this new option indicates whether to detect
+ a mismatch between the current executable file loaded by GDB and the
+ executable file used to start the process. If 'ask', the default,
+ display a warning and ask the user whether to load the process
+ executable file; if 'warn', just display a warning; if 'off', don't
+ attempt to detect a mismatch.
+
+tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
+ Define a new TUI layout, specifying its name and the windows that
+ will be displayed.
+
+* New targets
+
+GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
+
+* Python API
+
+ ** gdb.register_window_type can be used to implement new TUI windows
+ in Python.
+
+ ** Dynamic types can now be queried. gdb.Type has a new attribute,
+ "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
+ field of a dynamic type may have None for its "bitpos" attribute
+ as well.
+
+ ** Commands written in Python can be in the "TUI" help class by
+ registering with the new constant gdb.COMMAND_TUI.
+
+*** Changes in GDB 9
+
+* 'thread-exited' event is now available in the annotations interface.
+
+* New built-in convenience variables $_gdb_major and $_gdb_minor
+ provide the GDB version. They are handy for conditionally using
+ features available only in or since specific GDB versions, in
+ scripts that should work error-free with many different versions,
+ such as in system-wide init files.
+
+* New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
+ $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
+ of the GDB settings and the GDB maintenance settings. They are handy
+ for changing the logic of user defined commands depending on the
+ current GDB settings.
+
+* GDB now supports Thread Local Storage (TLS) variables on several
+ FreeBSD architectures (amd64, i386, powerpc, riscv). Other
+ architectures require kernel changes. TLS is not yet supported for
+ amd64 and i386 process core dumps.
+
+* Support for Pointer Authentication (PAC) on AArch64 Linux. Return
+ addresses that required unmasking are shown in the backtrace with the
+ postfix [PAC].
+
+* Two new convenience functions $_cimag and $_creal that extract the
+ imaginary and real parts respectively from complex numbers.
+
+* New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
+ provide the exitcode or exit status of the shell commands launched by
+ GDB commands such as "shell", "pipe" and "make".
+
+* The command define-prefix can now define user defined prefix commands.
+ User defined commands can now be defined using these user defined prefix
+ commands.
+
+* Command names can now use the . character.
+
+* The RX port now supports XML target descriptions.
+
+* GDB now shows the Ada task names at more places, e.g. in task switching
+ messages.
+
+* GDB can now be compiled with Python 3 on Windows.
+
+* New convenience variable $_ada_exception holds the address of the
+ Ada exception being thrown. This is set by Ada-related catchpoints.
+
+* GDB can now place breakpoints on nested functions and subroutines in
+ Fortran code. The '::' operator can be used between parent and
+ child scopes when placing breakpoints, for example:
+
+ (gdb) break outer_function::inner_function
+
+ The 'outer_function::' prefix is only needed if 'inner_function' is
+ not visible in the current scope.
+
+* In addition to the system-wide gdbinit file, if configured with
+ --with-system-gdbinit-dir, GDB will now also load files in that directory
+ as system gdbinit files, unless the -nx or -n flag is provided. Files
+ with extensions .gdb, .py and .scm are supported as long as GDB was
+ compiled with support for that language.
+
+* GDB now supports multithreaded symbol loading for higher performance.
+ This feature is still in testing, so it is disabled by default. You
+ can turn it on using 'maint set worker-threads unlimited'.
+
+* Multi-target debugging support
+
+ GDB now supports debugging multiple target connections
+ simultaneously. For example, you can now have each inferior
+ connected to different remote servers running in different machines,
+ or have one inferior debugging a local native process, an inferior
+ debugging a core dump, etc.
+
+ This support is experimental and comes with some limitations -- you
+ can only resume multiple targets simultaneously if all targets
+ support non-stop mode, and all remote stubs or servers must support
+ the same set of remote protocol features exactly. See also "info
+ connections" and "add-inferior -no-connection" below, and "maint set
+ target-non-stop" in the user manual.
+
+* Python API
+
+ ** The gdb.Value type has a new method 'format_string' which returns a
+ string representing the value. The formatting is controlled by the
+ optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
+ 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
+ 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
+
+ ** gdb.Type has a new property 'objfile' which returns the objfile the
+ type was defined in.
+
+ ** The frame information printed by the python frame filtering code
+ is now consistent with what the 'backtrace' command prints when
+ there are no filters, or when the 'backtrace' '-no-filters' option
+ is given.
+
+ ** The new function gdb.lookup_static_symbol can be used to look up
+ symbols with static linkage.
+
+ ** The new function gdb.lookup_static_symbols can be used to look up
+ all static symbols with static linkage.
+
+ ** gdb.Objfile has new methods 'lookup_global_symbol' and
+ 'lookup_static_symbol' to lookup a symbol from this objfile only.
+
+ ** gdb.Block now supports the dictionary syntax for accessing symbols in
+ this block (e.g. block['local_variable']).
+
+* New commands
+
+| [COMMAND] | SHELL_COMMAND
+| -d DELIM COMMAND DELIM SHELL_COMMAND
+pipe [COMMAND] | SHELL_COMMAND
+pipe -d DELIM COMMAND DELIM SHELL_COMMAND
+ Executes COMMAND and sends its output to SHELL_COMMAND.
+ With no COMMAND, repeat the last executed command
+ and send its output to SHELL_COMMAND.
+
+define-prefix COMMAND
+ Define or mark a command as a user-defined prefix command.
+
+with SETTING [VALUE] [-- COMMAND]
+w SETTING [VALUE] [-- COMMAND]
+ Temporarily set SETTING, run COMMAND, and restore SETTING.
+ Usage: with SETTING -- COMMAND
+ With no COMMAND, repeats the last executed command.
+ SETTING is any GDB setting you can change with the "set"
+ subcommands. For example, 'with language c -- print someobj'
+ temporarily switches to the C language in order to print someobj.
+ Settings can be combined: 'w lang c -- w print elements unlimited --
+ usercmd' switches to the C language and runs usercmd with no limit
+ of array elements to print.
+
+maint with SETTING [VALUE] [-- COMMAND]
+ Like "with", but works with "maintenance set" settings.
+
+set may-call-functions [on|off]
+show may-call-functions
+ This controls whether GDB will attempt to call functions in
+ the program, such as with expressions in the print command. It
+ defaults to on. Calling functions in the program being debugged
+ can have undesired side effects. It is now possible to forbid
+ such function calls. If function calls are forbidden, GDB will throw
+ an error when a command (such as print expression) calls a function
+ in the program.
+
+set print finish [on|off]
+show print finish
+ This controls whether the `finish' command will display the value
+ that is returned by the current function. When `off', the value is
+ still entered into the value history, but it is not printed. The
+ default is `on'.
+
+set print max-depth
+show print max-depth
+ Allows deeply nested structures to be simplified when printing by
+ replacing deeply nested parts (beyond the max-depth) with ellipses.
+ The default max-depth is 20, but this can be set to unlimited to get
+ the old behavior back.
+
+set print raw-values [on|off]
+show print raw-values
+ By default, GDB applies the enabled pretty printers when printing a
+ value. This allows to ignore the enabled pretty printers for a series
+ of commands. The default is 'off'.
+
+set logging debugredirect [on|off]
+ By default, GDB debug output will go to both the terminal and the logfile.
+ Set if you want debug output to go only to the log file.
+
+set style title foreground COLOR
+set style title background COLOR
+set style title intensity VALUE
+ Control the styling of titles.
+
+set style highlight foreground COLOR
+set style highlight background COLOR
+set style highlight intensity VALUE
+ Control the styling of highlightings.
+
+maint set worker-threads
+maint show worker-threads
+ Control the number of worker threads that can be used by GDB. The
+ default is 0. "unlimited" lets GDB choose a number that is
+ reasonable. Currently worker threads are only used when demangling
+ the names of linker symbols.
+
+set style tui-border foreground COLOR
+set style tui-border background COLOR
+ Control the styling of TUI borders.
+
+set style tui-active-border foreground COLOR
+set style tui-active-border background COLOR
+ Control the styling of the active TUI border.
+
+maint set test-settings KIND
+maint show test-settings KIND
+ A set of commands used by the testsuite for exercising the settings
+ infrastructure.
+
+maint set tui-resize-message [on|off]
+maint show tui-resize-message
+ Control whether GDB prints a message each time the terminal is
+ resized when in TUI mode. This is primarily useful for testing the
+ TUI.
+
+set print frame-info [short-location|location|location-and-address
+ |source-and-location|source-line|auto]
+show print frame-info
+ This controls what frame information is printed by the commands printing
+ a frame. This setting will e.g. influence the behaviour of 'backtrace',
+ 'frame', 'stepi'. The python frame filtering also respect this setting.
+ The 'backtrace' '-frame-info' option can override this global setting.
+
+set tui compact-source
+show tui compact-source
+
+ Enable the "compact" display mode for the TUI source window. The
+ compact display uses only as much space as is needed for the line
+ numbers in the current file, and only a single space to separate the
+ line numbers from the source.
+
+info modules [-q] [REGEXP]
+ Return a list of Fortran modules matching REGEXP, or all modules if
+ no REGEXP is given.
+
+info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
+ Return a list of functions within all modules, grouped by module.
+ The list of functions can be restricted with the optional regular
+ expressions. MODULE_REGEXP matches against the module name,
+ TYPE_REGEXP matches against the function type signature, and REGEXP
+ matches against the function name.
+
+info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
+ Return a list of variables within all modules, grouped by module.
+ The list of variables can be restricted with the optional regular
+ expressions. MODULE_REGEXP matches against the module name,
+ TYPE_REGEXP matches against the variable type, and REGEXP matches
+ against the variable name.
+
+set debug remote-packet-max-chars
+show debug remote-packet-max-chars
+ Controls the number of characters to output in a remote packet when using
+ "set debug remote".
+ The default is 512 bytes.
+
+info connections
+ Lists the target connections currently in use.
+
+* Changed commands
+
+help
+ The "help" command uses the title style to enhance the
+ readibility of its output by styling the classes and
+ command names.
+
+apropos [-v] REGEXP
+ Similarly to "help", the "apropos" command also uses the
+ title style for the command names. "apropos" accepts now
+ a flag "-v" (verbose) to show the full documentation
+ of matching commands and to use the highlight style to mark
+ the documentation parts matching REGEXP.
+
+printf
+eval
+ The GDB printf and eval commands can now print C-style and Ada-style
+ string convenience variables without calling functions in the program.
+ This allows to do formatted printing of strings without having
+ a running inferior, or when debugging a core dump.
+
+info sources [-dirname | -basename] [--] [REGEXP]
+ This command has now optional arguments to only print the files
+ whose names match REGEXP. The arguments -dirname and -basename
+ allow to restrict matching respectively to the dirname and basename
+ parts of the files.
+
+show style
+ The "show style" and its subcommands are now styling
+ a style name in their output using its own style, to help
+ the user visualize the different styles.
+
+set print frame-arguments
+ The new value 'presence' indicates to only indicate the presence of
+ arguments using ..., instead of printing argument names and values.
+
+set print raw-frame-arguments
+show print raw-frame-arguments
+
+ These commands replace the similarly-named "set/show print raw
+ frame-arguments" commands (now with a dash instead of a space). The
+ old commands are now deprecated and may be removed in a future
+ release.
+
+add-inferior [-no-connection]
+ The add-inferior command now supports a "-no-connection" flag that
+ makes the new inferior start with no target connection associated.
+ By default, the new inferior inherits the target connection of the
+ current inferior. See also "info connections".
+
+info inferior
+ This command's output now includes a new "Connection" column
+ indicating which target connection an inferior is bound to. See
+ "info connections" above.
+
+maint test-options require-delimiter
+maint test-options unknown-is-error
+maint test-options unknown-is-operand
+maint show test-options-completion-result
+ Commands used by the testsuite to validate the command options
+ framework.
+
+focus, winheight, +, -, >, <
+ These commands are now case-sensitive.
+
+* New command options, command completion
+
+ GDB now has a standard infrastructure to support dash-style command
+ options ('-OPT'). One benefit is that commands that use it can
+ easily support completion of command line arguments. Try "CMD
+ -[TAB]" or "help CMD" to find options supported by a command. Over
+ time, we intend to migrate most commands to this infrastructure. A
+ number of commands got support for new command options in this
+ release:
+
+ ** The "print" and "compile print" commands now support a number of
+ options that allow overriding relevant global print settings as
+ set by "set print" subcommands:
+
+ -address [on|off]
+ -array [on|off]
+ -array-indexes [on|off]
+ -elements NUMBER|unlimited
+ -null-stop [on|off]
+ -object [on|off]
+ -pretty [on|off]
+ -raw-values [on|off]
+ -repeats NUMBER|unlimited
+ -static-members [on|off]
+ -symbol [on|off]
+ -union [on|off]
+ -vtbl [on|off]
+
+ Note that because the "print"/"compile print" commands accept
+ arbitrary expressions which may look like options (including
+ abbreviations), if you specify any command option, then you must
+ use a double dash ("--") to mark the end of argument processing.
+
+ ** The "backtrace" command now supports a number of options that
+ allow overriding relevant global print settings as set by "set
+ backtrace" and "set print" subcommands:
+
+ -entry-values no|only|preferred|if-needed|both|compact|default
+ -frame-arguments all|scalars|none
+ -raw-frame-arguments [on|off]
+ -frame-info auto|source-line|location|source-and-location
+ |location-and-address|short-location
+ -past-main [on|off]
+ -past-entry [on|off]
+
+ In addition, the full/no-filters/hide qualifiers are now also
+ exposed as command options too:
+
+ -full
+ -no-filters
+ -hide
+
+ ** The "frame apply", "tfaas" and "faas" commands similarly now
+ support the following options:
+
+ -past-main [on|off]
+ -past-entry [on|off]
+
+ ** The new "info sources" options -dirname and -basename options
+ are using the standard '-OPT' infrastructure.
+
+ All options above can also be abbreviated. The argument of boolean
+ (on/off) options can be 0/1 too, and also the argument is assumed
+ "on" if omitted. This allows writing compact command invocations,
+ like for example:
+
+ (gdb) p -ra -p -o 0 -- *myptr
+
+ The above is equivalent to:
+
+ (gdb) print -raw-values -pretty -object off -- *myptr
+
+ ** The "info types" command now supports the '-q' flag to disable
+ printing of some header information in a similar fashion to "info
+ variables" and "info functions".
+
+ ** The "info variables", "info functions", and "whereis" commands
+ now take a '-n' flag that excludes non-debug symbols (symbols
+ from the symbol table, not from the debug info such as DWARF)
+ from the results.
+
+* Completion improvements
+
+ ** GDB can now complete the options of the "thread apply all" and
+ "taas" commands, and their "-ascending" option can now be
+ abbreviated.
+
+ ** GDB can now complete the options of the "info threads", "info
+ functions", "info variables", "info locals", and "info args"
+ commands.
+
+ ** GDB can now complete the options of the "compile file" and
+ "compile code" commands. The "compile file" command now
+ completes on filenames.
+
+ ** GDB can now complete the backtrace command's
+ "full/no-filters/hide" qualifiers.
+
+* In settings, you can now abbreviate "unlimited".
+
+ E.g., "set print elements u" is now equivalent to "set print
+ elements unlimited".
+
+* New MI commands
+
+-complete
+ This lists all the possible completions for the rest of the line, if it
+ were to be given as a command itself. This is intended for use by MI
+ frontends in cases when separate CLI and MI channels cannot be used.
+
+-catch-throw, -catch-rethrow, and -catch-catch
+ These can be used to catch C++ exceptions in a similar fashion to
+ the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
+
+-symbol-info-functions, -symbol-info-types, and -symbol-info-variables
+ These commands are the MI equivalent of the CLI commands 'info
+ functions', 'info types', and 'info variables' respectively.
+
+-symbol-info-modules, this is the MI equivalent of the CLI 'info
+ modules' command.
+
+-symbol-info-module-functions and -symbol-info-module-variables.
+ These commands are the MI equivalent of the CLI commands 'info
+ module functions' and 'info module variables'.
+
+* Other MI changes
+
+ ** The default version of the MI interpreter is now 3 (-i=mi3).
+
+ ** The output of information about multi-location breakpoints (which is
+ syntactically incorrect in MI 2) has changed in MI 3. This affects
+ the following commands and events:
+
+ - -break-insert
+ - -break-info
+ - =breakpoint-created
+ - =breakpoint-modified
+
+ The -fix-multi-location-breakpoint-output command can be used to enable
+ this behavior with previous MI versions.
+
+ ** Backtraces and frames include a new optional field addr_flags which is
+ given after the addr field. On AArch64 this contains PAC if the address
+ has been masked in the frame. On all other targets the field is not
+ present.
+
+* Testsuite
+
+ The testsuite now creates the files gdb.cmd (containing the arguments
+ used to launch GDB) and gdb.in (containing all the commands sent to
+ GDB) in the output directory for each test script. Multiple invocations
+ are appended with .1, .2, .3 etc.
+
+* Building GDB and GDBserver now requires GNU make >= 3.82.
+
+ Using another implementation of the make program or an earlier version of
+ GNU make to build GDB or GDBserver is not supported.
+
+* Building GDB now requires GNU readline >= 7.0.
+
+ GDB now bundles GNU readline 8.0, but if you choose to use
+ --with-system-readline, only readline >= 7.0 can be used.
+
+* The TUI SingleKey keymap is now named "SingleKey". This can be used
+ from .inputrc to bind keys in this keymap. This feature is only
+ available when gdb is built against GNU readline 8.0 or later.
+
+* Removed targets and native configurations
+
+ GDB no longer supports debugging the Cell Broadband Engine. This includes
+ both debugging standalone Cell/B.E. SPU applications and integrated debugging
+ of Cell/B.E. applications that use both the PPU and SPU architectures.
+
+* New Simulators
+
+TI PRU pru-*-elf
+
+* Removed targets and native configurations
+
+Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
+ sparc*-*-solaris2.10
+
+*** Changes in GDB 8.3
* GDB and GDBserver now support access to additional registers on
PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
* GDB in batch mode now exits with status 1 if the last command to be
executed failed.
-* Changes to the "frame", "select-frame", and "info frame" CLI
- commands. These commands all now take a frame specification which
- is either a frame level, or one of the keywords 'level', 'address',
- 'function', or 'view' followed by a parameter. Selecting a frame by
- address, or viewing a frame outside the current backtrace now
- requires the use of a keyword. Selecting a frame by level is
- unchanged. The MI comment "-stack-select-frame" is unchanged.
-
* The RISC-V target now supports target descriptions.
* System call catchpoints now support system call aliases on FreeBSD.
source code snippets. See the "set style" commands, below, for more
information.
-* New targets
-
- NXP S12Z s12z-*-elf
- GNU/Linux/OpenRISC or1k*-*-linux*
+* Removed support for old demangling styles arm, edg, gnu, hp and
+ lucid.
* New commands
* Changed commands
+Changes to the "frame", "select-frame", and "info frame" CLI commands.
+ These commands all now take a frame specification which
+ is either a frame level, or one of the keywords 'level', 'address',
+ 'function', or 'view' followed by a parameter. Selecting a frame by
+ address, or viewing a frame outside the current backtrace now
+ requires the use of a keyword. Selecting a frame by level is
+ unchanged. The MI comment "-stack-select-frame" is unchanged.
+
target remote FILENAME
target extended-remote FILENAME
If FILENAME is a Unix domain socket, GDB will attempt to connect
set style enabled [on|off]
show style enabled
Enable or disable terminal styling. Styling is enabled by default
- on most hosts.
+ on most hosts, but disabled by default when in batch mode.
+
+set style sources [on|off]
+show style sources
+ Enable or disable source code styling. Source code styling is
+ enabled by default, but only takes effect if styling in general is
+ enabled, and if GDB was linked with GNU Source Highlight.
set style filename foreground COLOR
set style filename background COLOR
CSKY ELF csky*-*-elf
CSKY GNU/LINUX csky*-*-linux
FreeBSD/riscv riscv*-*-freebsd*
+NXP S12Z s12z-*-elf
+GNU/Linux/OpenRISC or1k*-*-linux*
+
+* Removed targets
+
+GDB no longer supports native debugging on versions of MS-Windows
+before Windows XP.
* Python API
+ ** GDB no longer supports Python versions less than 2.6.
+
** The gdb.Inferior type has a new 'progspace' property, which is the program
space associated to that inferior.
gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
correct and did not work properly.
+ ** The gdb.Value type has a new constructor, which is used to construct a
+ gdb.Value from a Python buffer object and a gdb.Type.
+
* Configure changes
--enable-ubsan
* Newly installed $prefix/bin/gcore acts as a shell interface for the
GDB command gcore.
-* GDB now implements the the C++ 'typeid' operator.
+* GDB now implements the C++ 'typeid' operator.
* The new convenience variable $_exception holds the exception being
thrown or caught at an exception-related catchpoint.
features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
i386 application).
-GDB 6.3 will be the last release to include the the registers[]
+GDB 6.3 will be the last release to include the registers[]
compatibility module that allowed out-of-date configurations to
continue to work. This change directly impacts the following
configurations:
remote side. The data cache could lead to incorrect results because
it doesn't know about volatile variables, thus making it impossible to
debug targets which use memory mapped I/O devices. `set remotecache
-off' turns the the data cache off.
+off' turns the data cache off.
* Remote targets may have threads
projects / deliverable / binutils-gdb.git / blobdiff