What has changed in GDB?
(Organized release by release)
-*** Changes since GDB 7.8
+*** Changes since GDB 7.10
+
+* Record btrace now supports non-stop mode.
+
+* Support for tracepoints on aarch64-linux was added in GDBserver.
+
+* The 'record instruction-history' command now indicates speculative execution
+ when using the Intel(R) Processor Trace recording format.
+
+* GDB now allows users to specify explicit locations, bypassing
+ the linespec parser. This feature is also available to GDB/MI
+ clients.
+
+* Multi-architecture debugging is supported on AArch64 GNU/Linux.
+ GDB now is able to debug both AArch64 applications and ARM applications
+ at the same time.
+
+* Support for fast tracepoints on aarch64-linux was added in GDBserver,
+ including JIT compiling fast tracepoint's conditional expression bytecode
+ into native code.
+
+* GDB now supports displaced stepping on AArch64 GNU/Linux.
+
+* New commands
+
+maint set target-non-stop (on|off|auto)
+maint show target-non-stop
+ Control whether GDB targets always operate in non-stop mode even if
+ "set non-stop" is "off". The default is "auto", meaning non-stop
+ mode is enabled if supported by the target.
+
+maint set bfd-sharing
+maint show bfd-sharing
+ Control the reuse of bfd objects.
+
+set debug bfd-cache
+show debug bfd-cache
+ Control display of debugging info regarding bfd caching.
+
+set remote multiprocess-extensions-packet
+show remote multiprocess-extensions-packet
+ Set/show the use of the remote protocol multiprocess extensions.
+
+* The "disassemble" command accepts a new modifier: /s.
+ It prints mixed source+disassembly like /m with two differences:
+ - disassembled instructions are now printed in program order, and
+ - and source for all relevant files is now printed.
+ The "/m" option is now considered deprecated: its "source-centric"
+ output hasn't proved useful in practice.
+
+* The "record instruction-history" command accepts a new modifier: /s.
+ It behaves exactly like /m and prints mixed source+disassembly.
+
+* The "set scheduler-locking" command supports a new mode "replay".
+ It behaves like "off" in record mode and like "on" in replay mode.
+
+* Support for various ROM monitors has been removed:
+
+ target dbug dBUG ROM monitor for Motorola ColdFire
+ target picobug Motorola picobug monitor
+ target dink32 DINK32 ROM monitor for PowerPC
+ target m32r Renesas M32R/D ROM monitor
+ target mon2000 mon2000 ROM monitor
+ target ppcbug PPCBUG ROM monitor for PowerPC
+
+* Support for reading/writing memory and extracting values on architectures
+ whose memory is addressable in units of any integral multiple of 8 bits.
+
+* New remote packets
+
+exec stop reason
+ Indicates that an exec system call was executed.
+
+exec-events feature in qSupported
+ The qSupported packet allows GDB to request support for exec
+ events using the new 'gdbfeature' exec-event, and the qSupported
+ response can contain the corresponding 'stubfeature'. Set and
+ show commands can be used to display whether these features are enabled.
+
+* Extended-remote exec events
+
+ ** GDB now has support for exec events on extended-remote Linux targets.
+ For such targets with Linux kernels 2.5.46 and later, this enables
+ follow-exec-mode and exec catchpoints.
+
+set remote exec-event-feature-packet
+show remote exec-event-feature-packet
+ Set/show the use of the remote exec event feature.
+
+*** Changes in GDB 7.10
+
+* Support for process record-replay and reverse debugging on aarch64*-linux*
+ targets has been added. GDB now supports recording of A64 instruction set
+ including advance SIMD instructions.
+
+* Support for Sun's version of the "stabs" debug file format has been removed.
+
+* GDB now honors the content of the file /proc/PID/coredump_filter
+ (PID is the process ID) on GNU/Linux systems. This file can be used
+ to specify the types of memory mappings that will be included in a
+ corefile. For more information, please refer to the manual page of
+ "core(5)". GDB also has a new command: "set use-coredump-filter
+ on|off". It allows to set whether GDB will read the content of the
+ /proc/PID/coredump_filter file when generating a corefile.
+
+* The "info os" command on GNU/Linux can now display information on
+ cpu information :
+ "info os cpus" Listing of all cpus/cores on the system
+
+* GDB has two new commands: "set serial parity odd|even|none" and
+ "show serial parity". These allows to set or show parity for the
+ remote serial I/O.
+
+* The "info source" command now displays the producer string if it was
+ present in the debug info. This typically includes the compiler version
+ and may include things like its command line arguments.
+
+* The "info dll", an alias of the "info sharedlibrary" command,
+ is now available on all platforms.
+
+* Directory names supplied to the "set sysroot" commands may be
+ prefixed with "target:" to tell GDB to access shared libraries from
+ the target system, be it local or remote. This replaces the prefix
+ "remote:". The default sysroot has been changed from "" to
+ "target:". "remote:" is automatically converted to "target:" for
+ backward compatibility.
+
+* The system root specified by "set sysroot" will be prepended to the
+ filename of the main executable (if reported to GDB as absolute by
+ the operating system) when starting processes remotely, and when
+ attaching to already-running local or remote processes.
+
+* GDB now supports automatic location and retrieval of executable
+ files from remote targets. Remote debugging can now be initiated
+ using only a "target remote" or "target extended-remote" command
+ (no "set sysroot" or "file" commands are required). See "New remote
+ packets" below.
+
+* The "dump" command now supports verilog hex format.
+
+* GDB now supports the vector ABI on S/390 GNU/Linux targets.
+
+* On GNU/Linux, GDB and gdbserver are now able to access executable
+ and shared library files without a "set sysroot" command when
+ attaching to processes running in different mount namespaces from
+ the debugger. This makes it possible to attach to processes in
+ containers as simply as "gdb -p PID" or "gdbserver --attach PID".
+ See "New remote packets" below.
+
+* The "tui reg" command now provides completion for all of the
+ available register groups, including target specific groups.
+
+* The HISTSIZE environment variable is no longer read when determining
+ the size of GDB's command history. GDB now instead reads the dedicated
+ GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
+ disables truncation of command history. Non-numeric values of GDBHISTSIZE
+ are ignored.
+
+* Guile Scripting
+
+ ** Memory ports can now be unbuffered.
+
+* Python Scripting
+
+ ** gdb.Objfile objects have a new attribute "username",
+ which is the name of the objfile as specified by the user,
+ without, for example, resolving symlinks.
+ ** You can now write frame unwinders in Python.
+ ** gdb.Type objects have a new method "optimized_out",
+ returning optimized out gdb.Value instance of this type.
+ ** gdb.Value objects have new methods "reference_value" and
+ "const_value" which return a reference to the value and a
+ "const" version of the value respectively.
+
+* New commands
+
+maint print symbol-cache
+ Print the contents of the symbol cache.
+
+maint print symbol-cache-statistics
+ Print statistics of symbol cache usage.
+
+maint flush-symbol-cache
+ Flush the contents of the symbol cache.
+
+record btrace bts
+record bts
+ Start branch trace recording using Branch Trace Store (BTS) format.
+
+compile print
+ Evaluate expression by using the compiler and print result.
+
+tui enable
+tui disable
+ Explicit commands for enabling and disabling tui mode.
+
+show mpx bound
+set mpx bound on i386 and amd64
+ Support for bound table investigation on Intel(R) MPX enabled applications.
+
+record btrace pt
+record pt
+ Start branch trace recording using Intel(R) Processor Trace format.
+
+maint info btrace
+ Print information about branch tracing internals.
+
+maint btrace packet-history
+ Print the raw branch tracing data.
+
+maint btrace clear-packet-history
+ Discard the stored raw branch tracing data.
+
+maint btrace clear
+ Discard all branch tracing data. It will be fetched and processed
+ anew by the next "record" command.
+
+* New options
+
+set debug dwarf-die
+ Renamed from "set debug dwarf2-die".
+show debug dwarf-die
+ Renamed from "show debug dwarf2-die".
+
+set debug dwarf-read
+ Renamed from "set debug dwarf2-read".
+show debug dwarf-read
+ Renamed from "show debug dwarf2-read".
+
+maint set dwarf always-disassemble
+ Renamed from "maint set dwarf2 always-disassemble".
+maint show dwarf always-disassemble
+ Renamed from "maint show dwarf2 always-disassemble".
+
+maint set dwarf max-cache-age
+ Renamed from "maint set dwarf2 max-cache-age".
+maint show dwarf max-cache-age
+ Renamed from "maint show dwarf2 max-cache-age".
+
+set debug dwarf-line
+show debug dwarf-line
+ Control display of debugging info regarding DWARF line processing.
+
+set max-completions
+show max-completions
+ Set the maximum number of candidates to be considered during
+ completion. The default value is 200. This limit allows GDB
+ to avoid generating large completion lists, the computation of
+ which can cause the debugger to become temporarily unresponsive.
+
+set history remove-duplicates
+show history remove-duplicates
+ Control the removal of duplicate history entries.
+
+maint set symbol-cache-size
+maint show symbol-cache-size
+ Control the size of the symbol cache.
+
+set|show record btrace bts buffer-size
+ Set and show the size of the ring buffer used for branch tracing in
+ BTS format.
+ The obtained size may differ from the requested size. Use "info
+ record" to see the obtained buffer size.
+
+set debug linux-namespaces
+show debug linux-namespaces
+ Control display of debugging info regarding Linux namespaces.
+
+set|show record btrace pt buffer-size
+ Set and show the size of the ring buffer used for branch tracing in
+ Intel(R) Processor Trace format.
+ The obtained size may differ from the requested size. Use "info
+ record" to see the obtained buffer size.
+
+maint set|show btrace pt skip-pad
+ Set and show whether PAD packets are skipped when computing the
+ packet history.
+
+* The command 'thread apply all' can now support new option '-ascending'
+ to call its specified command for all threads in ascending order.
+
+* Python/Guile scripting
+
+ ** GDB now supports auto-loading of Python/Guile scripts contained in the
+ special section named `.debug_gdb_scripts'.
+
+* New remote packets
+
+qXfer:btrace-conf:read
+ Return the branch trace configuration for the current thread.
+
+Qbtrace-conf:bts:size
+ Set the requested ring buffer size for branch tracing in BTS format.
+
+Qbtrace:pt
+ Enable Intel(R) Procesor Trace-based branch tracing for the current
+ process. The remote stub reports support for this packet to GDB's
+ qSupported query.
+
+Qbtrace-conf:pt:size
+ Set the requested ring buffer size for branch tracing in Intel(R) Processor
+ Trace format.
+
+swbreak stop reason
+ Indicates a memory breakpoint instruction was executed, irrespective
+ of whether it was GDB that planted the breakpoint or the breakpoint
+ is hardcoded in the program. This is required for correct non-stop
+ mode operation.
+
+hwbreak stop reason
+ Indicates the target stopped for a hardware breakpoint. This is
+ required for correct non-stop mode operation.
+
+vFile:fstat:
+ Return information about files on the remote system.
+
+qXfer:exec-file:read
+ Return the full absolute name of the file that was executed to
+ create a process running on the remote system.
+
+vFile:setfs:
+ Select the filesystem on which vFile: operations with filename
+ arguments will operate. This is required for GDB to be able to
+ access files on remote targets where the remote stub does not
+ share a common filesystem with the inferior(s).
+
+fork stop reason
+ Indicates that a fork system call was executed.
+
+vfork stop reason
+ Indicates that a vfork system call was executed.
+
+vforkdone stop reason
+ Indicates that a vfork child of the specified process has executed
+ an exec or exit, allowing the vfork parent to resume execution.
+
+fork-events and vfork-events features in qSupported
+ The qSupported packet allows GDB to request support for fork and
+ vfork events using new 'gdbfeatures' fork-events and vfork-events,
+ and the qSupported response can contain the corresponding
+ 'stubfeatures'. Set and show commands can be used to display
+ whether these features are enabled.
+
+* Extended-remote fork events
+
+ ** GDB now has support for fork events on extended-remote Linux
+ targets. For targets with Linux kernels 2.5.60 and later, this
+ enables follow-fork-mode and detach-on-fork for both fork and
+ vfork, as well as fork and vfork catchpoints.
+
+* The info record command now shows the recording format and the
+ branch tracing configuration for the current thread when using
+ the btrace record target.
+ For the BTS format, it shows the ring buffer size.
+
+* GDB now has support for DTrace USDT (Userland Static Defined
+ Tracing) probes. The supported targets are x86_64-*-linux-gnu.
+
+* GDB now supports access to vector registers on S/390 GNU/Linux
+ targets.
+
+* Removed command line options
+
+-xdb HP-UX XDB compatibility mode.
+
+* Removed targets and native configurations
+
+HP/PA running HP-UX hppa*-*-hpux*
+Itanium running HP-UX ia64-*-hpux*
+
+* New configure options
+
+--with-intel-pt
+ This configure option allows the user to build GDB with support for
+ Intel(R) Processor Trace (default: auto). This requires libipt.
+
+--with-libipt-prefix=PATH
+ Specify the path to the version of libipt that GDB should use.
+ $PATH/include should contain the intel-pt.h header and
+ $PATH/lib should contain the libipt.so library.
+
+*** Changes in GDB 7.9.1
+
+* Python Scripting
+
+ ** Xmethods can now specify a result type.
+
+*** Changes in GDB 7.9
* GDB now supports hardware watchpoints on x86 GNU Hurd.
** You can now access frame registers from Python scripts.
** New attribute 'producer' for gdb.Symtab objects.
+ ** gdb.Objfile objects have a new attribute "progspace",
+ which is the gdb.Progspace object of the containing program space.
+ ** gdb.Objfile objects have a new attribute "owner".
+ ** gdb.Objfile objects have a new attribute "build_id",
+ which is the build ID generated when the file was built.
+ ** gdb.Objfile objects have a new method "add_separate_debug_file".
+ ** A new event "gdb.clear_objfiles" has been added, triggered when
+ selecting a new file to debug.
+ ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
+ ** New function gdb.lookup_objfile.
+
+ New events which are triggered when GDB modifies the state of the
+ inferior.
+
+ ** gdb.events.inferior_call_pre: Function call is about to be made.
+ ** gdb.events.inferior_call_post: Function call has just been made.
+ ** gdb.events.memory_changed: A memory location has been altered.
+ ** gdb.events.register_changed: A register has been altered.
* New Python-based convenience functions:
** $_any_caller_is(name [, number_of_frames])
** $_any_caller_matches(regexp [, number_of_frames])
+* GDB now supports the compilation and injection of source code into
+ the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
+ to compile the source code to object code, and if successful, inject
+ and execute that code within the current context of the inferior.
+ Currently the C language is supported. The commands used to
+ interface with this new feature are:
+
+ compile code [-raw|-r] [--] [source code]
+ compile file [-raw|-r] filename
+
* New commands
+demangle [-l language] [--] name
+ Demangle "name" in the specified language, or the current language
+ if elided. This command is renamed from the "maint demangle" command.
+ The latter is kept as a no-op to avoid "maint demangle" being interpreted
+ as "maint demangler-warning".
+
queue-signal signal-name-or-number
Queue a signal to be delivered to the thread when it is resumed.
+add-auto-load-scripts-directory directory
+ Add entries to the list of directories from which to load auto-loaded
+ scripts.
+
+maint print user-registers
+ List all currently available "user" registers.
+
+compile code [-r|-raw] [--] [source code]
+ Compile, inject, and execute in the inferior the executable object
+ code produced by compiling the provided source code.
+
+compile file [-r|-raw] filename
+ Compile and inject into the inferior the executable object code
+ produced by compiling the source code stored in the filename
+ provided.
+
* On resume, GDB now always passes the signal the program had stopped
for to the thread the signal was sent to, even if the user changed
threads before resuming. Previously GDB would often (but not
even in non-stop mode. The "auto" mode has been removed, and "off"
is now the default mode.
+* New options
+
+set debug symbol-lookup
+show debug symbol-lookup
+ Control display of debugging info regarding symbol lookup.
+
* MI changes
** The -list-thread-groups command outputs an exit-code field for
inferiors that have exited.
+* New targets
+
+MIPS SDE mips*-sde*-elf*
+
+* Removed targets
+
+Support for these obsolete configurations has been removed.
+
+Alpha running OSF/1 (or Tru64) alpha*-*-osf*
+SGI Irix-5.x mips-*-irix5*
+SGI Irix-6.x mips-*-irix6*
+VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
+VAX running Ultrix vax-*-ultrix*
+
+* The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
+ and "assf"), have been removed. Use the "sharedlibrary" command, or
+ its alias "share", instead.
+
*** Changes in GDB 7.8
* New command line options
maint set target-async (on|off)
maint show target-async
- This controls whether GDB targets operate in syncronous or
- asyncronous mode. Normally the default is asyncronous, if it is
+ This controls whether GDB targets operate in synchronous or
+ asynchronous mode. Normally the default is asynchronous, if it is
available; but this can be changed to more easily debug problems
- occurring only in syncronous mode.
+ occurring only in synchronous mode.
set mi-async (on|off)
show mi-async