\input texinfo @c -*-texinfo-*-
-@c Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998,
-@c 1999, 2000, 2001, 2002, 2003, 2004, 2005
+@c Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998,
+@c 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
@c Free Software Foundation, Inc.
@c
@c %**start of header
Version @value{GDBVN}.
Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998,@*
- 1999, 2000, 2001, 2002, 2003, 2004, 2005@*
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006@*
Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
@vskip 0pt plus 1filll
Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
-1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
+1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006
Free Software Foundation, Inc.
@sp 2
Published by the Free Software Foundation @*
-59 Temple Place - Suite 330, @*
-Boston, MA 02111-1307 USA @*
+51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA@*
ISBN 1-882114-77-9 @*
Permission is granted to copy, distribute and/or modify this document
This is the @value{EDITION} Edition, for @value{GDBN} Version
@value{GDBVN}.
-Copyright (C) 1988-2005 Free Software Foundation, Inc.
+Copyright (C) 1988-2006 Free Software Foundation, Inc.
@menu
* Summary:: Summary of @value{GDBN}
So that they may not regard their many labors as thankless, we
particularly thank those who shepherded @value{GDBN} through major
releases:
-Andrew Cagney (releases 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0);
+Andrew Cagney (releases 6.3, 6.2, 6.1, 6.0, 5.3, 5.2, 5.1 and 5.0);
Jim Blandy (release 4.18);
Jason Molenda (release 4.17);
Stan Shebs (release 4.14);
Thorpe, Corinna Vinschen, Ulrich Weigand, and Elena Zannoni, helped
with the migration of old architectures to this new framework.
+Andrew Cagney completely re-designed and re-implemented @value{GDBN}'s
+unwinder framework, this consisting of a fresh new design featuring
+frame IDs, independent frame sniffers, and the sentinel frame. Mark
+Kettenis implemented the @sc{dwarf 2} unwinder, Jeff Johnston the
+libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and
+trad unwinders. The architecture specific changes, each involving a
+complete rewrite of the architecture's frame code, were carried out by
+Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane
+Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel
+Jacobowitz, Jeff Johnston, Mark Kettenis, Theodore A. Roth, Kei
+Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich
+Weigand.
+
@node Sample Session
@chapter A Sample @value{GDBN} Session
first attempt to attach to it as a process, and if that fails, attempt
to open it as a corefile. If you have a corefile whose name begins with
a digit, you can prevent @value{GDBN} from treating it as a pid by
-prefixing it with @file{./}, eg. @file{./12345}.
+prefixing it with @file{./}, e.g.@: @file{./12345}.
If @value{GDBN} has not been configured to included core file support,
such as for most embedded targets, then it will complain about a second
Execute @value{GDBN} commands from file @var{file}. @xref{Command
Files,, Command files}.
+@item -eval-command @var{command}
+@itemx -ex @var{command}
+@cindex @code{--eval-command}
+@cindex @code{-ex}
+Execute a single @value{GDBN} command.
+
+This option may be used multiple times to call multiple commands. It may
+also be interleaved with @samp{-command} as required.
+
+@smallexample
+@value{GDBP} -ex 'target sim' -ex 'load' \
+ -x setbreakpoints -ex 'run' a.out
+@end smallexample
+
@item -directory @var{directory}
@itemx -d @var{directory}
@cindex @code{--directory}
@cindex @code{-d}
-Add @var{directory} to the path to search for source files.
-
-@item -m
-@itemx -mapped
-@cindex @code{--mapped}
-@cindex @code{-m}
-@emph{Warning: this option depends on operating system facilities that are not
-supported on all systems.}@*
-If memory-mapped files are available on your system through the @code{mmap}
-system call, you can use this option
-to have @value{GDBN} write the symbols from your
-program into a reusable file in the current directory. If the program you are debugging is
-called @file{/tmp/fred}, the mapped symbol file is @file{/tmp/fred.syms}.
-Future @value{GDBN} debugging sessions notice the presence of this file,
-and can quickly map in symbol information from it, rather than reading
-the symbol table from the executable program.
-
-The @file{.syms} file is specific to the host machine where @value{GDBN}
-is run. It holds an exact image of the internal @value{GDBN} symbol
-table. It cannot be shared across multiple host platforms.
+Add @var{directory} to the path to search for source and script files.
@item -r
@itemx -readnow
@end table
-You typically combine the @code{-mapped} and @code{-readnow} options in
-order to build a @file{.syms} file that contains complete symbol
-information. (@xref{Files,,Commands to specify files}, for information
-on @file{.syms} files.) A simple @value{GDBN} invocation to do nothing
-but build a @file{.syms} file for future use is:
-
-@smallexample
-gdb -batch -nx -mapped -readnow programname
-@end smallexample
-
@node Mode Options
@subsection Choosing modes
@value{GDBN} control terminates) is not issued when running in batch
mode.
+@item -batch-silent
+@cindex @code{--batch-silent}
+Run in batch mode exactly like @samp{-batch}, but totally silently. All
+@value{GDBN} output to @code{stdout} is prevented (@code{stderr} is
+unaffected). This is much quieter than @samp{-silent} and would be useless
+for an interactive session.
+
+This is particularly useful when using targets that give @samp{Loading section}
+messages, for example.
+
+Note that targets that give their output via @value{GDBN}, as opposed to
+writing directly to @code{stdout}, will also be made silent.
+
+@item -return-child-result
+@cindex @code{--return-child-result}
+The return code from @value{GDBN} will be the return code from the child
+process (the process being debugged), with the following exceptions:
+
+@itemize @bullet
+@item
+@value{GDBN} exits abnormally. E.g., due to an incorrect argument or an
+internal error. In this case the exit code is the same as it would have been
+without @samp{-return-child-result}.
+@item
+The user quits with an explicit value. E.g., @samp{quit 1}.
+@item
+The child process never runs, or is not allowed to terminate, in which case
+the exit code will be -1.
+@end itemize
+
+This option is useful in conjunction with @samp{-batch} or @samp{-batch-silent},
+when @value{GDBN} is being used as a remote program loader or simulator
+interface.
+
@item -nowindows
@itemx -nw
@cindex @code{--nowindows}
@sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs
that control @value{GDBN}, and level 2 has been deprecated.
-The annotation mechanism has largely been superseeded by @sc{gdb/mi}
+The annotation mechanism has largely been superseded by @sc{gdb/mi}
(@pxref{GDB/MI}).
@item --args
@item
Reads the command history recorded in the @dfn{history file}.
-@xref{History}, for more details about the command history and the
+@xref{Command History}, for more details about the command history and the
files where @value{GDBN} records it.
@end enumerate
* Threads:: Debugging programs with multiple threads
* Processes:: Debugging programs with multiple processes
+* Checkpoint/Restart:: Setting a @emph{bookmark} to return to later
@end menu
@node Compilation
When you use the @code{tty} command or redirect input in the @code{run}
command, only the input @emph{for your program} is affected. The input
-for @value{GDBN} still comes from your terminal.
+for @value{GDBN} still comes from your terminal. @code{tty} is an alias
+for @code{set inferior-tty}.
+
+@cindex inferior tty
+@cindex set inferior controlling terminal
+You can use the @code{show inferior-tty} command to tell @value{GDBN} to
+display the name of the terminal that will be used for future runs of your
+program.
+
+@table @code
+@item set inferior-tty /dev/ttyb
+@kindex set inferior-tty
+Set the tty for the program being debugged to /dev/ttyb.
+
+@item show inferior-tty
+@kindex show inferior-tty
+Show the current tty for the program being debugged.
+@end table
@node Attach
@section Debugging an already-running process
threads.
@kindex thread apply
-@item thread apply [@var{threadno}] [@var{all}] @var{args}
-The @code{thread apply} command allows you to apply a command to one or
-more threads. Specify the numbers of the threads that you want affected
-with the command argument @var{threadno}. @var{threadno} is the internal
-@value{GDBN} thread number, as shown in the first field of the @samp{info
-threads} display. To apply a command to all threads, use
-@code{thread apply all} @var{args}.
+@cindex apply command to several threads
+@item thread apply [@var{threadno}] [@var{all}] @var{command}
+The @code{thread apply} command allows you to apply the named
+@var{command} to one or more threads. Specify the numbers of the
+threads that you want affected with the command argument
+@var{threadno}. It can be a single thread number, one of the numbers
+shown in the first field of the @samp{info threads} display; or it
+could be a range of thread numbers, as in @code{2-4}. To apply a
+command to all threads, type @kbd{thread apply all @var{command}}.
@end table
@cindex automatic thread selection
Display the current debugger response to a @code{fork} or @code{vfork} call.
@end table
+@cindex debugging multiple processes
+On Linux, if you want to debug both the parent and child processes, use the
+command @w{@code{set detach-on-fork}}.
+
+@table @code
+@kindex set detach-on-fork
+@item set detach-on-fork @var{mode}
+Tells gdb whether to detach one of the processes after a fork, or
+retain debugger control over them both.
+
+@table @code
+@item on
+The child process (or parent process, depending on the value of
+@code{follow-fork-mode}) will be detached and allowed to run
+independently. This is the default.
+
+@item off
+Both processes will be held under the control of @value{GDBN}.
+One process (child or parent, depending on the value of
+@code{follow-fork-mode}) is debugged as usual, while the other
+is held suspended.
+
+@end table
+
+@kindex show detach-on-follow
+@item show detach-on-follow
+Show whether detach-on-follow mode is on/off.
+@end table
+
+If you choose to set @var{detach-on-follow} mode off, then
+@value{GDBN} will retain control of all forked processes (including
+nested forks). You can list the forked processes under the control of
+@value{GDBN} by using the @w{@code{info forks}} command, and switch
+from one fork to another by using the @w{@code{fork}} command.
+
+@table @code
+@kindex info forks
+@item info forks
+Print a list of all forked processes under the control of @value{GDBN}.
+The listing will include a fork id, a process id, and the current
+position (program counter) of the process.
+
+
+@kindex fork @var{fork-id}
+@item fork @var{fork-id}
+Make fork number @var{fork-id} the current process. The argument
+@var{fork-id} is the internal fork number assigned by @value{GDBN},
+as shown in the first field of the @samp{info forks} display.
+
+@end table
+
+To quit debugging one of the forked processes, you can either detach
+from it by using the @w{@code{detach-fork}} command (allowing it to
+run independently), or delete (and kill) it using the
+@w{@code{delete fork}} command.
+
+@table @code
+@kindex detach-fork @var{fork-id}
+@item detach-fork @var{fork-id}
+Detach from the process identified by @value{GDBN} fork number
+@var{fork-id}, and remove it from the fork list. The process will be
+allowed to run independently.
+
+@kindex delete fork @var{fork-id}
+@item delete fork @var{fork-id}
+Kill the process identified by @value{GDBN} fork number @var{fork-id},
+and remove it from the fork list.
+
+@end table
+
If you ask to debug a child process and a @code{vfork} is followed by an
@code{exec}, @value{GDBN} executes the new target up to the first
breakpoint in the new target. If you have a breakpoint set on
a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set
Catchpoints, ,Setting catchpoints}.
+@node Checkpoint/Restart
+@section Setting a @emph{bookmark} to return to later
+
+@cindex checkpoint
+@cindex restart
+@cindex bookmark
+@cindex snapshot of a process
+@cindex rewind program state
+
+On certain operating systems@footnote{Currently, only
+@sc{gnu}/Linux.}, @value{GDBN} is able to save a @dfn{snapshot} of a
+program's state, called a @dfn{checkpoint}, and come back to it
+later.
+
+Returning to a checkpoint effectively undoes everything that has
+happened in the program since the @code{checkpoint} was saved. This
+includes changes in memory, registers, and even (within some limits)
+system state. Effectively, it is like going back in time to the
+moment when the checkpoint was saved.
+
+Thus, if you're stepping thru a program and you think you're
+getting close to the point where things go wrong, you can save
+a checkpoint. Then, if you accidentally go too far and miss
+the critical statement, instead of having to restart your program
+from the beginning, you can just go back to the checkpoint and
+start again from there.
+
+This can be especially useful if it takes a lot of time or
+steps to reach the point where you think the bug occurs.
+
+To use the @code{checkpoint}/@code{restart} method of debugging:
+
+@table @code
+@kindex checkpoint
+@item checkpoint
+Save a snapshot of the debugged program's current execution state.
+The @code{checkpoint} command takes no arguments, but each checkpoint
+is assigned a small integer id, similar to a breakpoint id.
+
+@kindex info checkpoints
+@item info checkpoints
+List the checkpoints that have been saved in the current debugging
+session. For each checkpoint, the following information will be
+listed:
+
+@table @code
+@item Checkpoint ID
+@item Process ID
+@item Code Address
+@item Source line, or label
+@end table
+
+@kindex restart @var{checkpoint-id}
+@item restart @var{checkpoint-id}
+Restore the program state that was saved as checkpoint number
+@var{checkpoint-id}. All program variables, registers, stack frames
+etc.@: will be returned to the values that they had when the checkpoint
+was saved. In essence, gdb will ``wind back the clock'' to the point
+in time when the checkpoint was saved.
+
+Note that breakpoints, @value{GDBN} variables, command history etc.
+are not affected by restoring a checkpoint. In general, a checkpoint
+only restores things that reside in the program being debugged, not in
+the debugger.
+
+@kindex delete checkpoint @var{checkpoint-id}
+@item delete checkpoint @var{checkpoint-id}
+Delete the previously-saved checkpoint identified by @var{checkpoint-id}.
+
+@end table
+
+Returning to a previously saved checkpoint will restore the user state
+of the program being debugged, plus a significant subset of the system
+(OS) state, including file pointers. It won't ``un-write'' data from
+a file, but it will rewind the file pointer to the previous location,
+so that the previously written data can be overwritten. For files
+opened in read mode, the pointer will also be restored so that the
+previously read data can be read again.
+
+Of course, characters that have been sent to a printer (or other
+external device) cannot be ``snatched back'', and characters received
+from eg.@: a serial device can be removed from internal program buffers,
+but they cannot be ``pushed back'' into the serial pipeline, ready to
+be received again. Similarly, the actual contents of files that have
+been changed cannot be restored (at this time).
+
+However, within those constraints, you actually can ``rewind'' your
+program to a previously saved point in time, and begin debugging it
+again --- and you can change the course of events so as to debug a
+different execution path this time.
+
+@cindex checkpoints and process id
+Finally, there is one bit of internal program state that will be
+different when you return to a checkpoint --- the program's process
+id. Each checkpoint will have a unique process id (or @var{pid}),
+and each will be different from the program's original @var{pid}.
+If your program has saved a local copy of its process id, this could
+potentially pose a problem.
+
+@subsection A non-obvious benefit of using checkpoints
+
+On some systems such as @sc{gnu}/Linux, address space randomization
+is performed on new processes for security reasons. This makes it
+difficult or impossible to set a breakpoint, or watchpoint, on an
+absolute address if you have to restart the program, since the
+absolute location of a symbol will change from one execution to the
+next.
+
+A checkpoint, however, is an @emph{identical} copy of a process.
+Therefore if you create a checkpoint at (eg.@:) the start of main,
+and simply return to that checkpoint instead of restarting the
+process, you can avoid the effects of address randomization and
+your symbols will all stay in the same place.
+
@node Stopping
@chapter Stopping and Continuing
@table @code
@kindex commands
-@kindex end
+@kindex end@r{ (breakpoint commands)}
@item commands @r{[}@var{bnum}@r{]}
@itemx @dots{} @var{command-list} @dots{}
@itemx end
The names @code{where} and @code{info stack} (abbreviated @code{info s})
are additional aliases for @code{backtrace}.
+@cindex multiple threads, backtrace
+In a multi-threaded program, @value{GDBN} by default shows the
+backtrace only for the current thread. To display the backtrace for
+several or all of the threads, use the command @code{thread apply}
+(@pxref{Threads, thread apply}). For example, if you type @kbd{thread
+apply all backtrace}, @value{GDBN} will display the backtrace for all
+the threads; this is handy when you debug a core dump of a
+multi-threaded program.
+
Each line in the backtrace shows the frame number and the function name.
The program counter value is also shown---unless you use @code{set
print address off}. The backtrace also shows the source file name and
@cindex startup code, and backtrace
Most programs have a standard user entry point---a place where system
libraries and startup code transition into user code. For C this is
-@code{main}. When @value{GDBN} finds the entry function in a backtrace
+@code{main}@footnote{
+Note that embedded programs (the so-called ``free-standing''
+environment) are not required to have a @code{main} function as the
+entry point. They could even have multiple entry points.}.
+When @value{GDBN} finds the entry function in a backtrace
it will terminate the backtrace, to avoid tracing into highly
system-specific (and generally uninteresting) code.
On the 29k architecture, it needs three addresses: a register stack
pointer, a program counter, and a memory stack pointer.
-@c note to future updaters: this is conditioned on a flag
-@c SETUP_ARBITRARY_FRAME in the tm-*.h files. The above is up to date
-@c as of 27 Jan 1994.
@kindex up
@item up @var{n}
that---@file{/mnt/cross/foo.c}.
Note that the executable search path is @emph{not} used to locate the
-source files. Neither is the current working directory, unless it
-happens to be in the source path.
+source files.
Whenever you reset or rearrange the source path, @value{GDBN} clears out
any information it has cached about where source files are found and where
and @samp{cwd}, in that order.
To add other directories, use the @code{directory} command.
+The search path is used to find both program source files and @value{GDBN}
+script files (read using the @samp{-command} option and @samp{source} command).
+
@table @code
@item directory @var{dirname} @dots{}
@item dir @var{dirname} @dots{}
directory at the time you add an entry to the source path.
@item directory
-Reset the source path to empty again. This requires confirmation.
+Reset the source path to its default value (@samp{$cdir:$cwd} on Unix systems). This requires confirmation.
@c RET-repeat for @code{directory} is explicitly disabled, but since
@c repeating it would be a no-op we do not say that. (thanks to RMS)
@enumerate
@item
-Use @code{directory} with no argument to reset the source path to empty.
+Use @code{directory} with no argument to reset the source path to its default value.
@item
Use @code{directory} with suitable arguments to reinstall the
Some architectures have more than one commonly-used set of instruction
mnemonics or other syntax.
+For programs that were dynamically linked and use shared libraries,
+instructions that call functions or branch to locations in the shared
+libraries might show a seemingly bogus location---it's actually a
+location of the relocation table. On some architectures, @value{GDBN}
+might be able to resolve these to actual function names.
+
@table @code
@kindex set disassembly-flavor
@cindex Intel disassembly flavor
@xref{C, , Debugging C++}, for more info about debug info formats
that are best suited to C@t{++} programs.
+If you ask to print an object whose contents are unknown to
+@value{GDBN}, e.g., because its data type is not completely specified
+by the debug information, @value{GDBN} will say @samp{<incomplete
+type>}. @xref{Symbols, incomplete type}, for more about this.
+
@node Arrays
@section Artificial arrays
Show whether compressed or pretty format is selected for displaying
arrays.
+@cindex print array indexes
+@item set print array-indexes
+@itemx set print array-indexes on
+Print the index of each element when displaying arrays. May be more
+convenient to locate a given element in the array or quickly find the
+index of a given element in that printed array. The default is off.
+
+@item set print array-indexes off
+Stop printing element indexes when displaying arrays.
+
+@item show print array-indexes
+Show whether the index of each element is printed when displaying
+arrays.
+
@item set print elements @var{number-of-elements}
@cindex number of array elements to print
@cindex limit on number of printed array elements
@item show convenience
Print a list of convenience variables used so far, and their values.
Abbreviated @code{show conv}.
+
+@kindex init-if-undefined
+@cindex convenience variables, initializing
+@item init-if-undefined $@var{variable} = @var{expression}
+Set a convenience variable if it has not already been set. This is useful
+for user-defined commands that keep some state. It is similar, in concept,
+to using local static variables with initializers in C (except that
+convenience variables are global). It can also be used to allow users to
+override default values used in a command script.
+
+If the variable is already defined then the expression is not evaluated so
+any side-effects do not occur.
@end table
One of the ways to use a convenience variable is as a counter to be
that makes sense for your program), but the @code{info registers} command
prints the data in both formats.
+@cindex SSE registers (x86)
+@cindex MMX registers (x86)
+Some machines have special registers whose contents can be interpreted
+in several different ways. For example, modern x86-based machines
+have SSE and MMX registers that can hold several values packed
+together in several different formats. @value{GDBN} refers to such
+registers in @code{struct} notation:
+
+@smallexample
+(@value{GDBP}) print $xmm1
+$1 = @{
+ v4_float = @{0, 3.43859137e-038, 1.54142831e-044, 1.821688e-044@},
+ v2_double = @{9.92129282474342e-303, 2.7585945287983262e-313@},
+ v16_int8 = "\000\000\000\000\3706;\001\v\000\000\000\r\000\000",
+ v8_int16 = @{0, 0, 14072, 315, 11, 0, 13, 0@},
+ v4_int32 = @{0, 20657912, 11, 13@},
+ v2_int64 = @{88725056443645952, 55834574859@},
+ uint128 = 0x0000000d0000000b013b36f800000000
+@}
+@end smallexample
+
+@noindent
+To set values of such registers, you need to tell @value{GDBN} which
+view of the register you wish to change, as if you were assigning
+value to a @code{struct} member:
+
+@smallexample
+ (@value{GDBP}) set $xmm1.uint128 = 0x000000000000000000000000FFFFFFFF
+@end smallexample
+
Normally, register values are relative to the selected stack frame
(@pxref{Selection, ,Selecting a frame}). This means that you get the
value that the register would contain if all stack frames farther in
While these attributes prevent @value{GDBN} from performing invalid
memory accesses, they do nothing to prevent the target system, I/O DMA,
-etc. from accessing memory.
+etc.@: from accessing memory.
@table @code
@item ro
unobtrusively, hopefully not disturbing the program's behavior.
The tracepoint facility is currently available only for remote
-targets. @xref{Targets}. In addition, your remote target must know how
-to collect trace data. This functionality is implemented in the remote
-stub; however, none of the stubs distributed with @value{GDBN} support
-tracepoints as of this writing.
+targets. @xref{Targets}. In addition, your remote target must know
+how to collect trace data. This functionality is implemented in the
+remote stub; however, none of the stubs distributed with @value{GDBN}
+support tracepoints as of this writing. The format of the remote
+packets used to implement tracepoints are described in @ref{Tracepoint
+Packets}.
This chapter describes the tracepoint commands and features.
@subsection Fortran
@cindex Fortran-specific support in @value{GDBN}
+@value{GDBN} can be used to debug programs written in Fortran, but it
+currently supports only the features of Fortran 77 language.
+
+@cindex trailing underscore, in Fortran symbols
+Some Fortran compilers (@sc{gnu} Fortran 77 and Fortran 95 compilers
+among them) append an underscore to the names of variables and
+functions. When you debug programs compiled by those compilers, you
+will need to refer to variables and functions with a trailing
+underscore.
+
+@menu
+* Fortran Operators:: Fortran operators and expressions
+* Fortran Defaults:: Default settings for Fortran
+* Special Fortran commands:: Special @value{GDBN} commands for Fortran
+@end menu
+
+@node Fortran Operators
+@subsubsection Fortran operators and expressions
+
+@cindex Fortran operators and expressions
+
+Operators must be defined on values of specific types. For instance,
+@code{+} is defined on numbers, but not on characters or other non-
+arithmetic types. Operators are often defined on groups of types.
+
+@table @code
+@item **
+The exponentiation operator. It raises the first operand to the power
+of the second one.
+
+@item :
+The range operator. Normally used in the form of array(low:high) to
+represent a section of array.
+@end table
+
+@node Fortran Defaults
+@subsubsection Fortran Defaults
+
+@cindex Fortran Defaults
+
+Fortran symbols are usually case-insensitive, so @value{GDBN} by
+default uses case-insensitive matches for Fortran symbols. You can
+change that with the @samp{set case-insensitive} command, see
+@ref{Symbols}, for the details.
+
+@node Special Fortran commands
+@subsubsection Special Fortran commands
+
+@cindex Special Fortran commands
+
+@value{GDBN} had some commands to support Fortran specific feature,
+such as common block displaying.
+
@table @code
@cindex @code{COMMON} blocks, Fortran
@kindex info common
printed.
@end table
-Fortran symbols are usually case-insensitive, so @value{GDBN} by
-default uses case-insensitive matches for Fortran symbols. You can
-change that with the @samp{set case-insensitive} command, see
-@ref{Symbols}, for the details.
-
@node Pascal
@subsection Pascal
are not implemented.
@item
-There are no record or array aggregates.
+@cindex array aggregates (Ada)
+@cindex record aggregates (Ada)
+@cindex aggregates (Ada)
+There is limited support for array and record aggregates. They are
+permitted only on the right sides of assignments, as in these examples:
+
+@smallexample
+set An_Array := (1, 2, 3, 4, 5, 6)
+set An_Array := (1, others => 0)
+set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6)
+set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9))
+set A_Record := (1, "Peter", True);
+set A_Record := (Name => "Peter", Id => 1, Alive => True)
+@end smallexample
+
+Changing a
+discriminant's value by assigning an aggregate has an
+undefined effect if that discriminant is used within the record.
+However, you can first modify discriminants by directly assigning to
+them (which normally would not be allowed in Ada), and then performing an
+aggregate assignment. For example, given a variable @code{A_Rec}
+declared to have a type such as:
+
+@smallexample
+type Rec (Len : Small_Integer := 0) is record
+ Id : Integer;
+ Vals : IntArray (1 .. Len);
+end record;
+@end smallexample
+
+you can assign a value with a different size of @code{Vals} with two
+assignments:
+
+@smallexample
+set A_Rec.Len := 4
+set A_Rec := (Id => 42, Vals => (1, 2, 3, 4))
+@end smallexample
+
+As this example also illustrates, @value{GDBN} is very loose about the usual
+rules concerning aggregates. You may leave out some of the
+components of an array or record aggregate (such as the @code{Len}
+component in the assignment to @code{A_Rec} above); they will retain their
+original values upon assignment. You may freely use dynamic values as
+indices in component associations. You may even use overlapping or
+redundant component associations, although which component values are
+assigned in such cases is not defined.
@item
Calls to dispatching subprograms are not implemented.
it to find out the name of a variable or a function given its address.
@kindex whatis
-@item whatis @var{expr}
-Print the data type of expression @var{expr}. @var{expr} is not
-actually evaluated, and any side-effecting operations (such as
-assignments or function calls) inside it do not take place.
+@item whatis [@var{arg}]
+Print the data type of @var{arg}, which can be either an expression or
+a data type. With no argument, print the data type of @code{$}, the
+last value in the value history. If @var{arg} is an expression, it is
+not actually evaluated, and any side-effecting operations (such as
+assignments or function calls) inside it do not take place. If
+@var{arg} is a type name, it may be the name of a type or typedef, or
+for C code it may have the form @samp{class @var{class-name}},
+@samp{struct @var{struct-tag}}, @samp{union @var{union-tag}} or
+@samp{enum @var{enum-tag}}.
@xref{Expressions, ,Expressions}.
-@item whatis
-Print the data type of @code{$}, the last value in the value history.
-
@kindex ptype
-@item ptype @var{typename}
-Print a description of data type @var{typename}. @var{typename} may be
-the name of a type, or for C code it may have the form @samp{class
-@var{class-name}}, @samp{struct @var{struct-tag}}, @samp{union
-@var{union-tag}} or @samp{enum @var{enum-tag}}.
-
-@item ptype @var{expr}
-@itemx ptype
-Print a description of the type of expression @var{expr}. @code{ptype}
-differs from @code{whatis} by printing a detailed description, instead
-of just the name of the type.
+@item ptype [@var{arg}]
+@code{ptype} accepts the same arguments as @code{whatis}, but prints a
+detailed description of the type, instead of just the name of the type.
+@xref{Expressions, ,Expressions}.
For example, for this variable declaration:
As with @code{whatis}, using @code{ptype} without an argument refers to
the type of @code{$}, the last value in the value history.
+@cindex incomplete type
+Sometimes, programs use opaque data types or incomplete specifications
+of complex data structure. If the debug information included in the
+program does not allow @value{GDBN} to display a full declaration of
+the data type, it will say @samp{<incomplete type>}. For example,
+given these declarations:
+
+@smallexample
+ struct foo;
+ struct foo *fooptr;
+@end smallexample
+
+@noindent
+but no definition for @code{struct foo} itself, @value{GDBN} will say:
+
+@smallexample
+ (gdb) ptype foo
+ $1 = <incomplete type>
+@end smallexample
+
+@noindent
+``Incomplete type'' is C terminology for data types that are not
+completely specified.
+
@kindex info types
@item info types @var{regexp}
@itemx info types
Thus, @samp{info fun step} finds all functions whose names
include @code{step}; @samp{info fun ^step} finds those whose names
start with @code{step}. If a function name contains characters
-that conflict with the regular expression language (eg.
+that conflict with the regular expression language (e.g.@:
@samp{operator*()}), they may be quoted with a backslash.
@kindex info variables
to run. You can change the value of this variable, for both @value{GDBN}
and your program, using the @code{path} command.
-On systems with memory-mapped files, an auxiliary file named
-@file{@var{filename}.syms} may hold symbol table information for
-@var{filename}. If so, @value{GDBN} maps in the symbol table from
-@file{@var{filename}.syms}, starting up more quickly. See the
-descriptions of the file options @samp{-mapped} and @samp{-readnow}
-(available on the command line, see @ref{File Options, , -readnow},
-and with the commands @code{file}, @code{symbol-file}, or
-@code{add-symbol-file}, described below), for more information.
+@cindex unlinked object files
+@cindex patching object files
+You can load unlinked object @file{.o} files into @value{GDBN} using
+the @code{file} command. You will not be able to ``run'' an object
+file, but you can disassemble functions and inspect variables. Also,
+if the underlying BFD functionality supports it, you could use
+@kbd{gdb -write} to patch object files using this technique. Note
+that @value{GDBN} can neither interpret nor modify relocations in this
+case, so branches and some initialized variables will appear to go to
+the wrong place. But this feature is still handy from time to time.
@item file
@code{file} with no argument makes @value{GDBN} discard any information it
@code{symbol-file} with no argument clears out @value{GDBN} information on your
program's symbol table.
-The @code{symbol-file} command causes @value{GDBN} to forget the contents
-of its convenience variables, the value history, and all breakpoints and
-auto-display expressions. This is because they may contain pointers to
-the internal data recording symbols and data types, which are part of
-the old symbol table data being discarded inside @value{GDBN}.
+The @code{symbol-file} command causes @value{GDBN} to forget the contents of
+some breakpoints and auto-display expressions. This is because they may
+contain pointers to the internal data recording symbols and data types,
+which are part of the old symbol table data being discarded inside
+@value{GDBN}.
@code{symbol-file} does not repeat if you press @key{RET} again after
executing it once.
@kindex readnow
@cindex reading symbols immediately
@cindex symbols, reading immediately
-@kindex mapped
-@cindex memory-mapped symbol file
-@cindex saving symbol table
-@item symbol-file @var{filename} @r{[} -readnow @r{]} @r{[} -mapped @r{]}
-@itemx file @var{filename} @r{[} -readnow @r{]} @r{[} -mapped @r{]}
+@item symbol-file @var{filename} @r{[} -readnow @r{]}
+@itemx file @var{filename} @r{[} -readnow @r{]}
You can override the @value{GDBN} two-stage strategy for reading symbol
tables by using the @samp{-readnow} option with any of the commands that
load symbol table information, if you want to be sure @value{GDBN} has the
entire symbol table available.
-If memory-mapped files are available on your system through the
-@code{mmap} system call, you can use another option, @samp{-mapped}, to
-cause @value{GDBN} to write the symbols for your program into a reusable
-file. Future @value{GDBN} debugging sessions map in symbol information
-from this auxiliary symbol file (if the program has not changed), rather
-than spending time reading the symbol table from the executable
-program. Using the @samp{-mapped} option has the same effect as
-starting @value{GDBN} with the @samp{-mapped} command-line option.
-
-You can use both options together, to make sure the auxiliary symbol
-file has all the symbol information for your program.
-
-The auxiliary symbol file for a program called @var{myprog} is called
-@samp{@var{myprog}.syms}. Once this file exists (so long as it is newer
-than the corresponding executable), @value{GDBN} always attempts to use
-it when you debug @var{myprog}; no special options or commands are
-needed.
-
-The @file{.syms} file is specific to the host machine where you run
-@value{GDBN}. It holds an exact image of the internal @value{GDBN}
-symbol table. It cannot be shared across multiple host platforms.
-
@c FIXME: for now no mention of directories, since this seems to be in
@c flux. 13mar1992 status is that in theory GDB would look either in
@c current dir or in same dir as myprog; but issues like competing
@kindex add-symbol-file
@cindex dynamic linking
@item add-symbol-file @var{filename} @var{address}
-@itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]} @r{[} -mapped @r{]}
+@itemx add-symbol-file @var{filename} @var{address} @r{[} -readnow @r{]}
@itemx add-symbol-file @var{filename} @r{-s}@var{section} @var{address} @dots{}
The @code{add-symbol-file} command reads additional symbol table
information from the file @var{filename}. You would use this command
@code{add-symbol-file} does not repeat if you press @key{RET} after using it.
-You can use the @samp{-mapped} and @samp{-readnow} options just as with
-the @code{symbol-file} command, to change how @value{GDBN} manages the symbol
-table information for @var{filename}.
-
@kindex add-symbol-file-from-memory
@cindex @code{syscall DSO}
@cindex load symbols from memory
copies on the target can be stripped as long as the copies on the host are
not.
-You need to tell @value{GDBN} where the target libraries are, so that it can
-load the correct copies---otherwise, it may try to load the host's libraries.
-@value{GDBN} has two variables to specify the search directories for target
-libraries.
+@cindex where to look for shared libraries
+For remote debugging, you need to tell @value{GDBN} where the target
+libraries are, so that it can load the correct copies---otherwise, it
+may try to load the host's libraries. @value{GDBN} has two variables
+to specify the search directories for target libraries.
@table @code
+@cindex prefix for shared library file names
@kindex set solib-absolute-prefix
@item set solib-absolute-prefix @var{path}
If this variable is set, @var{path} will be used as a prefix for any
out in the same way that they are on the target, with e.g.@: a
@file{/usr/lib} hierarchy under @var{path}.
+@cindex default value of @samp{solib-absolute-prefix}
+@cindex @samp{--with-sysroot}
You can set the default value of @samp{solib-absolute-prefix} by using the
configure-time @samp{--with-sysroot} option.
A core dump file. @samp{target core @var{filename}} is the same as
@samp{core-file @var{filename}}.
-@item target remote @var{dev}
+@item target remote @var{medium}
@cindex remote target
-Remote serial target in GDB-specific protocol. The argument @var{dev}
-specifies what serial device to use for the connection (e.g.
-@file{/dev/ttya}). @xref{Remote, ,Remote debugging}. @code{target remote}
-supports the @code{load} command. This is only useful if you have
-some other way of getting the stub to the target system, and you can put
-it somewhere in memory where it won't get clobbered by the download.
+A remote system connected to @value{GDBN} via a serial line or network
+connection. This command tells @value{GDBN} to use its own remote
+protocol over @var{medium} for debugging. @xref{Remote Debugging}.
+
+For example, if you have a board connected to @file{/dev/ttya} on the
+machine running @value{GDBN}, you could say:
+
+@smallexample
+target remote /dev/ttya
+@end smallexample
+
+@code{target remote} supports the @code{load} command. This is only
+useful if you have some other way of getting the stub to the target
+system, and you can put it somewhere in memory where it won't get
+clobbered by the download.
@item target sim
@cindex built-in simulator target
@menu
* Connecting:: Connecting to a remote target
* Server:: Using the gdbserver program
-* NetWare:: Using the gdbserve.nlm program
* Remote configuration:: Remote configuration
* remote stub:: Implementing a remote stub
@end menu
Start up @value{GDBN} as usual, using the name of the local copy of your
program as the first argument.
+@cindex @code{target remote}
+@value{GDBN} can communicate with the target over a serial line, or
+over an @acronym{IP} network using @acronym{TCP} or @acronym{UDP}. In
+each case, @value{GDBN} uses the same protocol for debugging your
+program; only the medium carrying the debugging packets varies. The
+@code{target remote} command establishes a connection to the target.
+Its arguments indicate which medium to use:
+
+@table @code
+
+@item target remote @var{serial-device}
@cindex serial line, @code{target remote}
+Use @var{serial-device} to communicate with the target. For example,
+to use a serial line connected to the device named @file{/dev/ttyb}:
+
+@smallexample
+target remote /dev/ttyb
+@end smallexample
+
If you're using a serial line, you may want to give @value{GDBN} the
@w{@samp{--baud}} option, or use the @code{set remotebaud} command
(@pxref{Remote configuration, set remotebaud}) before the
@code{target} command.
-After that, use @code{target remote} to establish communications with
-the target machine. Its argument specifies how to communicate---either
-via a devicename attached to a direct serial line, or a TCP or UDP port
-(possibly to a terminal server which in turn has a serial line to the
-target). For example, to use a serial line connected to the device
-named @file{/dev/ttyb}:
-
-@smallexample
-target remote /dev/ttyb
-@end smallexample
+@item target remote @code{@var{host}:@var{port}}
+@itemx target remote @code{tcp:@var{host}:@var{port}}
+@cindex @acronym{TCP} port, @code{target remote}
+Debug using a @acronym{TCP} connection to @var{port} on @var{host}.
+The @var{host} may be either a host name or a numeric @acronym{IP}
+address; @var{port} must be a decimal number. The @var{host} could be
+the target machine itself, if it is directly connected to the net, or
+it might be a terminal server which in turn has a serial line to the
+target.
-@cindex TCP port, @code{target remote}
-To use a TCP connection, use an argument of the form
-@code{@var{host}:@var{port}} or @code{tcp:@var{host}:@var{port}}.
-For example, to connect to port 2828 on a
-terminal server named @code{manyfarms}:
+For example, to connect to port 2828 on a terminal server named
+@code{manyfarms}:
@smallexample
target remote manyfarms:2828
@end smallexample
-If your remote target is actually running on the same machine as
-your debugger session (e.g.@: a simulator of your target running on
-the same host), you can omit the hostname. For example, to connect
-to port 1234 on your local machine:
+If your remote target is actually running on the same machine as your
+debugger session (e.g.@: a simulator for your target running on the
+same host), you can omit the hostname. For example, to connect to
+port 1234 on your local machine:
@smallexample
target remote :1234
Note that the colon is still required here.
-@cindex UDP port, @code{target remote}
-To use a UDP connection, use an argument of the form
-@code{udp:@var{host}:@var{port}}. For example, to connect to UDP port 2828
-on a terminal server named @code{manyfarms}:
+@item target remote @code{udp:@var{host}:@var{port}}
+@cindex @acronym{UDP} port, @code{target remote}
+Debug using @acronym{UDP} packets to @var{port} on @var{host}. For example, to
+connect to @acronym{UDP} port 2828 on a terminal server named @code{manyfarms}:
@smallexample
target remote udp:manyfarms:2828
@end smallexample
-When using a UDP connection for remote debugging, you should keep in mind
-that the `U' stands for ``Unreliable''. UDP can silently drop packets on
-busy or unreliable networks, which will cause havoc with your debugging
-session.
+When using a @acronym{UDP} connection for remote debugging, you should
+keep in mind that the `U' stands for ``Unreliable''. @acronym{UDP}
+can silently drop packets on busy or unreliable networks, which will
+cause havoc with your debugging session.
+
+@item target remote | @var{command}
+@cindex pipe, @code{target remote} to
+Run @var{command} in the background and communicate with it using a
+pipe. The @var{command} is a shell command, to be parsed and expanded
+by the system's command shell, @code{/bin/sh}; it should expect remote
+protocol packets on its standard input, and send replies on its
+standard output. You could use this to run a stand-alone simulator
+that speaks the remote debugging protocol, to make net connections
+using programs like @code{ssh}, or for other similar tricks.
-Now you can use all the usual commands to examine and change data and to
-step and continue the remote program.
+If @var{command} closes its standard output (perhaps by exiting),
+@value{GDBN} will try to send it a @code{SIGTERM} signal. (If the
+program has already exited, this will have no effect.)
+
+@end table
+
+Once the connection has been established, you can use all the usual
+commands to examine and change data and to step and continue the
+remote program.
@cindex interrupting remote programs
@cindex remote programs, interrupting
another target.
@cindex send command to remote monitor
+@cindex extend @value{GDBN} for remote targets
+@cindex add new commands for external monitor
@kindex monitor
@item monitor @var{cmd}
-This command allows you to send commands directly to the remote
-monitor.
+This command allows you to send arbitrary commands directly to the
+remote monitor. Since @value{GDBN} doesn't care about the commands it
+sends like this, this command is the way to extend @value{GDBN}---you
+can add new commands that only the external monitor will understand
+and implement.
@end table
@node Server
@end table
-@node NetWare
-@section Using the @code{gdbserve.nlm} program
-
-@kindex gdbserve.nlm
-@code{gdbserve.nlm} is a control program for NetWare systems, which
-allows you to connect your program with a remote @value{GDBN} via
-@code{target remote}.
-
-@value{GDBN} and @code{gdbserve.nlm} communicate via a serial line,
-using the standard @value{GDBN} remote serial protocol.
-
-@table @emph
-@item On the target machine,
-you need to have a copy of the program you want to debug.
-@code{gdbserve.nlm} does not need your program's symbol table, so you
-can strip the program if necessary to save space. @value{GDBN} on the
-host system does all the symbol handling.
-
-To use the server, you must tell it how to communicate with
-@value{GDBN}; the name of your program; and the arguments for your
-program. The syntax is:
-
-@smallexample
-load gdbserve [ BOARD=@var{board} ] [ PORT=@var{port} ]
- [ BAUD=@var{baud} ] @var{program} [ @var{args} @dots{} ]
-@end smallexample
-
-@var{board} and @var{port} specify the serial line; @var{baud} specifies
-the baud rate used by the connection. @var{port} and @var{node} default
-to 0, @var{baud} defaults to 9600@dmn{bps}.
-
-For example, to debug Emacs with the argument @samp{foo.txt}and
-communicate with @value{GDBN} over serial port number 2 or board 1
-using a 19200@dmn{bps} connection:
-
-@smallexample
-load gdbserve BOARD=1 PORT=2 BAUD=19200 emacs foo.txt
-@end smallexample
-
-@item
-On the @value{GDBN} host machine, connect to your target (@pxref{Connecting,,
-Connecting to a remote target}).
-
-@end table
-
@node Remote configuration
@section Remote configuration
@item set remotebreak
@cindex interrupt remote programs
@cindex BREAK signal instead of Ctrl-C
+@anchor{set remotebreak}
If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote
when you press the @key{Ctrl-C} key to interrupt the program running
-on the remote. If set to off, @value{GDBN} sends the @samp{Strl-C}
+on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C}
character instead. The default is off, since most remote systems
expect to see @samp{Ctrl-C} as the interrupt signal.
Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to
interrupt the remote program.
-@item set remotedebug
-@cindex debug remote protocol
-@cindex remote protocol debugging
-@cindex display remote packets
-Control the debugging of the remote protocol. When enabled, each
-packet sent to or received from the remote target is displayed. The
-defaults is off.
-
-@item show remotedebug
-Show the current setting of the remote protocol debugging.
-
@item set remotedevice @var{device}
@cindex serial port name
Set the name of the serial port through which to communicate to the
@kindex set debugevents
@item set debugevents
-This boolean value adds debug output concerning events seen by the debugger.
+This boolean value adds debug output concerning kernel events related
+to the debuggee seen by the debugger. This includes events that
+signal thread and process creation and exit, DLL loading and
+unloading, console interrupts, and debugging messages produced by the
+Windows @code{OutputDebugString} API call.
@kindex set debugexec
@item set debugexec
This boolean value adds debug output concerning execute events
-seen by the debugger.
+(such as resume thread) seen by the debugger.
@kindex set debugexceptions
@item set debugexceptions
-This boolean value adds debug ouptut concerning exception events
-seen by the debugger.
+This boolean value adds debug output concerning exceptions in the
+debuggee seen by the debugger.
@kindex set debugmemory
@item set debugmemory
-This boolean value adds debug ouptut concerning memory events
-seen by the debugger.
+This boolean value adds debug output concerning debuggee memory reads
+and writes by the debugger.
@kindex set shell
@item set shell
@menu
* Prompt:: Prompt
* Editing:: Command editing
-* History:: Command history
+* Command History:: Command history
* Screen Size:: Screen size
* Numbers:: Numbers
* ABI:: Configuring the current ABI
interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are
encouraged to read that chapter.
-@node History
+@node Command History
@section Command history
@cindex command history
package, to provide the history facility. @xref{Using History
Interactively}, for the detailed description of the History library.
+To issue a command to @value{GDBN} without affecting certain aspects of
+the state which is seen by users, prefix it with @samp{server }. This
+means that this command will not affect the command history, nor will it
+affect @value{GDBN}'s notion of which command to repeat if @key{RET} is
+pressed on a line by itself.
+
+@cindex @code{server}, command prefix
+The server prefix does not affect the recording of values into the value
+history; to print a value without recording it into the value history,
+use the @code{output} command instead of the @code{print} command.
+
Here is the description of @value{GDBN} commands related to command
history.
@item set debug overload
@cindex C@t{++} overload debugging info
Turns on or off display of @value{GDBN} C@t{++} overload debugging
-info. This includes info such as ranking of functions, etc. The default
+info. This includes info such as ranking of functions, etc. The default
is off.
@item show debug overload
Displays the current state of displaying @value{GDBN} C@t{++} overload
debugging info.
@cindex packets, reporting on stdout
@cindex serial connections, debugging
+@cindex debug remote protocol
+@cindex remote protocol debugging
+@cindex display remote packets
@item set debug remote
Turns on or off display of reports on all packets sent back and forth across
the serial line to the remote machine. The info is printed on the
files.
@menu
-* Define:: User-defined commands
-* Hooks:: User-defined command hooks
-* Command Files:: Command files
-* Output:: Commands for controlled output
+* Define:: How to define your own commands
+* Hooks:: Hooks for user-defined commands
+* Command Files:: How to write scripts of commands to be stored in a file
+* Output:: Commands for controlled output
@end menu
@node Define
@section User-defined commands
@cindex user-defined command
+@cindex arguments, to user-defined commands
A @dfn{user-defined command} is a sequence of @value{GDBN} commands to
which you assign a new name as a command. This is done with the
@code{define} command. User commands may accept up to 10 arguments
separated by whitespace. Arguments are accessed within the user command
-via @var{$arg0@dots{}$arg9}. A trivial example:
+via @code{$arg0@dots{}$arg9}. A trivial example:
@smallexample
define adder
print $arg0 + $arg1 + $arg2
+end
@end smallexample
@noindent
reference variables, use complex expressions, or even perform inferior
functions calls.
+@cindex argument count in user-defined commands
+@cindex how many arguments (user-defined commands)
+In addition, @code{$argc} may be used to find out how many arguments have
+been passed. This expands to a number in the range 0@dots{}10.
+
+@smallexample
+define adder
+ if $argc == 2
+ print $arg0 + $arg1
+ end
+ if $argc == 3
+ print $arg0 + $arg1 + $arg2
+ end
+end
+@end smallexample
+
@table @code
@kindex define
which are given following the @code{define} command. The end of these
commands is marked by a line containing @code{end}.
-@kindex if
-@kindex else
-@item if
-@itemx else
-Takes a single argument, which is an expression to evaluate.
-It is followed by a series of commands that are executed
-only if the expression is true (nonzero).
-There can then optionally be a line @code{else}, followed
-by a series of commands that are only executed if the expression
-was false. The end of the list is marked by a line containing @code{end}.
-
-@kindex while
-@item while
-The syntax is similar to @code{if}: the command takes a single argument,
-which is an expression to evaluate, and must be followed by the commands to
-execute, one per line, terminated by an @code{end}.
-The commands are executed repeatedly as long as the expression
-evaluates to true.
-
@kindex document
+@kindex end@r{ (user-defined commands)}
@item document @var{commandname}
Document the user-defined command @var{commandname}, so that it can be
accessed by @code{help}. The command @var{commandname} must already be
not its documentation). If no @var{commandname} is given, display the
definitions for all user-defined commands.
-@cindex infinite recusrion in user-defined commands
+@cindex infinite recursion in user-defined commands
@kindex show max-user-call-depth
@kindex set max-user-call-depth
@item show max-user-call-depth
The value of @code{max-user-call-depth} controls how many recursion
levels are allowed in user-defined commands before GDB suspects an
infinite recursion and aborts the command.
-
@end table
+In addition to the above commands, user-defined commands frequently
+use control flow commands, described in @ref{Command Files}.
+
When user-defined commands are executed, the
commands of the definition are not printed. An error in any command
stops execution of the user-defined command.
You can define a hook for any single-word command in @value{GDBN}, but
not for command aliases; you should define a hook for the basic command
-name, e.g. @code{backtrace} rather than @code{bt}.
+name, e.g.@: @code{backtrace} rather than @code{bt}.
@c FIXME! So how does Joe User discover whether a command is an alias
@c or not?
If an error occurs during the execution of your hook, execution of
@section Command files
@cindex command files
+@cindex scripting commands
A command file for @value{GDBN} is a text file made of lines that are
@value{GDBN} commands. Comments (lines starting with @kbd{#}) may
also be included. An empty line in a command file does nothing; it
@table @code
@kindex source
+@cindex execute commands from a file
@item source @var{filename}
Execute the command file @var{filename}.
@end table
-The lines in a command file are executed sequentially. They are not
+The lines in a command file are generally executed sequentially,
+unless the order of execution is changed by one of the
+@emph{flow-control commands} described below. The commands are not
printed as they are executed. An error in any command terminates
execution of the command file and control is returned to the console.
+@value{GDBN} searches for @var{filename} in the current directory and then
+on the search path (specified with the @samp{directory} command).
+
Commands that would ask for confirmation if used interactively proceed
without asking when used in a command file. Many @value{GDBN} commands that
normally print messages to say what they are doing omit the messages
will execute commands from the file @file{cmds}. All output and errors
would be directed to @file{log}.
+Since commands stored on command files tend to be more general than
+commands typed interactively, they frequently need to deal with
+complicated situations, such as different or unexpected values of
+variables and symbols, changes in how the program being debugged is
+built, etc. @value{GDBN} provides a set of flow-control commands to
+deal with these complexities. Using these commands, you can write
+complex scripts that loop over data structures, execute commands
+conditionally, etc.
+
+@table @code
+@kindex if
+@kindex else
+@item if
+@itemx else
+This command allows to include in your script conditionally executed
+commands. The @code{if} command takes a single argument, which is an
+expression to evaluate. It is followed by a series of commands that
+are executed only if the expression is true (its value is nonzero).
+There can then optionally be an @code{else} line, followed by a series
+of commands that are only executed if the expression was false. The
+end of the list is marked by a line containing @code{end}.
+
+@kindex while
+@item while
+This command allows to write loops. Its syntax is similar to
+@code{if}: the command takes a single argument, which is an expression
+to evaluate, and must be followed by the commands to execute, one per
+line, terminated by an @code{end}. These commands are called the
+@dfn{body} of the loop. The commands in the body of @code{while} are
+executed repeatedly as long as the expression evaluates to true.
+
+@kindex loop_break
+@item loop_break
+This command exits the @code{while} loop in whose body it is included.
+Execution of the script continues after that @code{while}s @code{end}
+line.
+
+@kindex loop_continue
+@item loop_continue
+This command skips the execution of the rest of the body of commands
+in the @code{while} loop in whose body it is included. Execution
+branches to the beginning of the @code{while} loop, where it evaluates
+the controlling expression.
+
+@kindex end@r{ (if/else/while commands)}
+@item end
+Terminate the block of commands that are the body of @code{if},
+@code{else}, or @code{while} flow-control commands.
+@end table
+
+
@node Output
@section Commands for controlled output
-command @var{args}@dots{}
@end smallexample
-@subsubheading @value{GDBN} Command
-
-The corresponding @value{GDBN} CLI command.
-
@subsubheading Result
-@subsubheading Out-of-band
+@subsubheading @value{GDBN} Command
-@subsubheading Notes
+The corresponding @value{GDBN} CLI command(s), if any.
@subsubheading Example
-
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Breakpoint Table Commands
@section @sc{gdb/mi} Breakpoint table commands
@smallexample
(@value{GDBP})
-break-insert main
-^done,bkpt=@{number="1",addr="0x000100d0",file="hello.c",line="5"@}
+^done,bkpt=@{number="1",addr="0x000100d0",file="hello.c",
+fullname="/home/foo/hello.c",line="5",times="0"@}
(@value{GDBP})
-break-after 1 3
~
@{width="10",alignment="-1",col_name="addr",colhdr="Address"@},
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
-addr="0x000100d0",func="main",file="hello.c",line="5",times="0",
-ignore="3"@}]@}
+addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+line="5",times="0",ignore="3"@}]@}
(@value{GDBP})
@end smallexample
@{width="10",alignment="-1",col_name="addr",colhdr="Address"@},
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
-addr="0x000100d0",func="main",file="hello.c",line="5",cond="1",
-times="0",ignore="3"@}]@}
+addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+line="5",cond="1",times="0",ignore="3"@}]@}
(@value{GDBP})
@end smallexample
@{width="10",alignment="-1",col_name="addr",colhdr="Address"@},
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="n",
-addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@}
+addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+line="5",times="0"@}]@}
(@value{GDBP})
@end smallexample
@{width="10",alignment="-1",col_name="addr",colhdr="Address"@},
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y",
-addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@}]@}
+addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
+line="5",times="0"@}]@}
(@value{GDBP})
@end smallexample
@table @samp
@item -t
-Insert a tempoary breakpoint.
+Insert a temporary breakpoint.
@item -h
Insert a hardware breakpoint.
@item -c @var{condition}
The result is in the form:
@smallexample
- ^done,bkptno="@var{number}",func="@var{funcname}",
- file="@var{filename}",line="@var{lineno}"
+^done,bkpt=@{number="@var{number}",type="@var{type}",disp="del"|"keep",
+enabled="y"|"n",addr="@var{hex}",func="@var{funcname}",file="@var{filename}",
+fullname="@var{full_filename}",line="@var{lineno}",times="@var{times}"@}
@end smallexample
@noindent
-where @var{number} is the @value{GDBN} number for this breakpoint, @var{funcname}
-is the name of the function where the breakpoint was inserted,
-@var{filename} is the name of the source file which contains this
-function, and @var{lineno} is the source line number within that file.
+where @var{number} is the @value{GDBN} number for this breakpoint,
+@var{funcname} is the name of the function where the breakpoint was
+inserted, @var{filename} is the name of the source file which contains
+this function, @var{lineno} is the source line number within that file
+and @var{times} the number of times that the breakpoint has been hit
+(always 0 for -break-insert but may be greater for -break-info or -break-list
+which use the same output).
Note: this format is open to change.
@c An out-of-band breakpoint instead of part of the result?
@smallexample
(@value{GDBP})
-break-insert main
-^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",line="4"@}
+^done,bkpt=@{number="1",addr="0x0001072c",file="recursive2.c",
+fullname="/home/foo/recursive2.c,line="4",times="0"@}
(@value{GDBP})
-break-insert -t foo
-^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c",line="11"@}
+^done,bkpt=@{number="2",addr="0x00010774",file="recursive2.c",
+fullname="/home/foo/recursive2.c,line="11",times="0"@}
(@value{GDBP})
-break-list
^done,BreakpointTable=@{nr_rows="2",nr_cols="6",
@{width="10",alignment="-1",col_name="addr",colhdr="Address"@},
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
-addr="0x0001072c", func="main",file="recursive2.c",line="4",times="0"@},
+addr="0x0001072c", func="main",file="recursive2.c",
+fullname="/home/foo/recursive2.c,"line="4",times="0"@},
bkpt=@{number="2",type="breakpoint",disp="del",enabled="y",
-addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"@}]@}
+addr="0x00010774",func="foo",file="recursive2.c",
+fullname="/home/foo/recursive2.c",line="11",times="0"@}]@}
(@value{GDBP})
-break-insert -r foo.*
~int foo(int, int);
-^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c",line="11"@}
+^done,bkpt=@{number="3",addr="0x00010774",file="recursive2.c,
+"fullname="/home/foo/recursive2.c",line="11",times="0"@}
(@value{GDBP})
@end smallexample
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",line="5",times="0"@},
bkpt=@{number="2",type="breakpoint",disp="keep",enabled="y",
-addr="0x00010114",func="foo",file="hello.c",line="13",times="0"@}]@}
+addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c",
+line="13",times="0"@}]@}
(@value{GDBP})
@end smallexample
^done,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@},
value=@{old="-268439212",new="55"@},
frame=@{func="main",args=[],file="recursive2.c",
-fullname="/home/foo/bar/devo/myproject/recursive2.c",line="5"@}
+fullname="/home/foo/bar/recursive2.c",line="5"@}
(@value{GDBP})
@end smallexample
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
-file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@},
+file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",times="1"@},
bkpt=@{number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="0"@}]@}
(@value{GDBP})
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
-file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@},
+file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@},
bkpt=@{number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="-5"@}]@}
(@value{GDBP})
@{width="40",alignment="2",col_name="what",colhdr="What"@}],
body=[bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
-file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"@}]@}
+file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
+times="1"@}]@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
*stopped,reason="breakpoint-hit",bkptno="1",frame=@{func="main",
-args=[],file="try.c",fullname="/home/foo/bar/devo/myproject/try.c",line="5"@}
+args=[],file="try.c",fullname="/home/foo/bar/try.c",line="5"@}
(@value{GDBP})
-data-list-changed-registers
^done,changed-registers=["0","1","2","4","5","6","7","8","9",
(@value{GDBP})
@@Hello world
*stopped,reason="breakpoint-hit",bkptno="2",frame=@{func="foo",args=[],
-file="hello.c",fullname="/home/foo/bar/devo/myproject/hello.c",line="13"@}
+file="hello.c",fullname="/home/foo/bar/hello.c",line="13"@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
@@hello from foo
*stopped,reason="function-finished",frame=@{func="main",args=[],
-file="hello.c",fullname="/home/foo/bar/devo/myproject/hello.c",line="7"@}
+file="hello.c",fullname="/home/foo/bar/hello.c",line="7"@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
*stopped,reason="function-finished",frame=@{addr="0x000107b0",func="foo",
args=[@{name="a",value="1"],@{name="b",value="9"@}@},
-file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
gdb-result-var="$1",return-value="0"
(@value{GDBP})
@end smallexample
(@value{GDBP})
111*stopped,signal-name="SIGINT",signal-meaning="Interrupt",
frame=@{addr="0x00010140",func="foo",args=[],file="try.c",
-fullname="/home/foo/bar/devo/myproject/try.c",line="13"@}
+fullname="/home/foo/bar/try.c",line="13"@}
(@value{GDBP})
(@value{GDBP})
(@value{GDBP})
*stopped,reason="breakpoint-hit",bkptno="1",
frame=@{func="main",args=[],file="recursive2.c",
-fullname="/home/foo/bar/devo/myproject/recursive2.c",line="4"@}
+fullname="/home/foo/bar/recursive2.c",line="4"@}
(@value{GDBP})
@end smallexample
*stopped,reason="end-stepping-range",
frame=@{func="foo",args=[@{name="a",value="10"@},
@{name="b",value="0"@}],file="recursive2.c",
-fullname="/home/foo/bar/devo/myproject/recursive2.c",line="11"@}
+fullname="/home/foo/bar/recursive2.c",line="11"@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
*stopped,reason="end-stepping-range",
frame=@{func="foo",args=[],file="try.c",
-fullname="/home/foo/bar/devo/myproject/try.c",line="10"@}
+fullname="/home/foo/bar/try.c",line="10"@}
(@value{GDBP})
-exec-step-instruction
^running
(@value{GDBP})
*stopped,reason="end-stepping-range",
frame=@{addr="0x000100f4",func="foo",args=[],file="try.c",
-fullname="/home/foo/bar/devo/myproject/try.c",line="10"@}
+fullname="/home/foo/bar/try.c",line="10"@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
x = 55
*stopped,reason="location-reached",frame=@{func="main",args=[],
-file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="6"@}
+file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"@}
(@value{GDBP})
@end smallexample
(@value{GDBP})
@end smallexample
-@ignore
-@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-@node GDB/MI Kod Commands
-@section @sc{gdb/mi} Kod Commands
+@subheading The @code{-inferior-tty-set} Command
+@findex -inferior-tty-set
-The Kod commands are not implemented.
+@subheading Synopsis
-@c @subheading -kod-info
+@smallexample
+-inferior-tty-set /dev/pts/1
+@end smallexample
+
+Set terminal for future runs of the program being debugged.
+
+@subheading @value{GDBN} Command
+
+The corresponding @value{GDBN} command is @samp{set inferior-tty /dev/pts/1}.
+
+@subheading Example
+
+@smallexample
+(@value{GDBP})
+-inferior-tty-set /dev/pts/1
+^done
+(@value{GDBP})
+@end smallexample
+
+@subheading The @code{-inferior-tty-show} Command
+@findex -inferior-tty-show
+
+@subheading Synopsis
+
+@smallexample
+-inferior-tty-show
+@end smallexample
+
+Show terminal for future runs of program being debugged.
+
+@subheading @value{GDBN} Command
+
+The corresponding @value{GDBN} command is @samp{show inferior-tty}.
+
+@subheading Example
+
+@smallexample
+(@value{GDBP})
+-inferior-tty-set /dev/pts/1
+^done
+(@value{GDBP})
+-inferior-tty-show
+^done,inferior_tty_terminal="/dev/pts/1"
+(@value{GDBP})
+@end smallexample
+
+@ignore
+@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+@node GDB/MI Kod Commands
+@section @sc{gdb/mi} Kod Commands
+
+The Kod commands are not implemented.
+
+@c @subheading -kod-info
@c @subheading -kod-list
@node GDB/MI Stack Manipulation
@section @sc{gdb/mi} Stack Manipulation Commands
+
+@subheading The @code{-stack-info-frame} Command
+@findex -stack-info-frame
+
+@subsubheading Synopsis
+
+@smallexample
+ -stack-info-frame
+@end smallexample
+
+Get info on the selected frame.
+
+@subsubheading @value{GDBN} Command
+
+The corresponding @value{GDBN} command is @samp{info frame} or @samp{frame}
+(without arguments).
+
+@subsubheading Example
+
+@smallexample
+(@value{GDBP})
+-stack-info-frame
+^done,frame=@{level="1",addr="0x0001076c",func="callee3",
+file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
+fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17"@}
+(@value{GDBP})
+@end smallexample
+
@subheading The @code{-stack-info-depth} Command
@findex -stack-info-depth
-stack-list-frames
^done,stack=
[frame=@{level="0",addr="0x0001076c",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="11"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11"@},
frame=@{level="1",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="2",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="3",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="4",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="5",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="6",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="7",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="8",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="9",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="10",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="11",addr="0x00010738",func="main",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="4"@}]
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"@}]
(@value{GDBP})
@end smallexample
-stack-list-frames 3 5
^done,stack=
[frame=@{level="3",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="4",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@},
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@},
frame=@{level="5",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}]
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}]
(@value{GDBP})
@end smallexample
-stack-list-frames 3 3
^done,stack=
[frame=@{level="3",addr="0x000107a4",func="foo",
- file="recursive2.c",fullname="/home/foo/bar/devo/myproject/recursive2.c",line="14"@}]
+ file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"@}]
(@value{GDBP})
@end smallexample
-stack-list-locals @var{print-values}
@end smallexample
-Display the local variable names for the current frame. With an
-argument of 0 or @code{--no-values}, prints only the names of the variables.
-With argument of 1 or @code{--all-values}, prints also their values. With
-argument of 2 or @code{--simple-values}, prints the name, type and value for
-simple data types and the name and type for arrays, structures and
-unions. In this last case, the idea is that the user can see the
-value of simple data types immediately and he can create variable
-objects for other data types if he wishes to explore their values in
+Display the local variable names for the selected frame. If
+@var{print-values} is 0 or @code{--no-values}, print only the names of
+the variables; if it is 1 or @code{--all-values}, print also their
+values; and if it is 2 or @code{--simple-values}, print the name,
+type and value for simple data types and the name and type for arrays,
+structures and unions. In this last case, a frontend can immediately
+display the value of simple data types and create variable objects for
+other data types when the the user wishes to explore their values in
more detail.
@subsubheading @value{GDBN} Command
-stack-select-frame @var{framenum}
@end smallexample
-Change the current frame. Select a different frame @var{framenum} on
+Change the selected frame. Select a different frame @var{framenum} on
the stack.
@subsubheading @value{GDBN} Command
@smallexample
-var-list-children [@var{print-values}] @var{name}
@end smallexample
+@anchor{-var-list-children}
-Returns a list of the children of the specified variable object. With
-just the variable object name as an argument or with an optional
-preceding argument of 0 or @code{--no-values}, prints only the names of the
-variables. With an optional preceding argument of 1 or @code{--all-values},
-also prints their values.
+Return a list of the children of the specified variable object and
+create variable objects for them, if they do not already exist. With
+a single argument or if @var{print-values} has a value for of 0 or
+@code{--no-values}, print only the names of the variables; if
+@var{print-values} is 1 or @code{--all-values}, also print their
+values; and if it is 2 or @code{--simple-values} print the name and
+value for simple data types and just the name for arrays, structures
+and unions.
@subsubheading Example
@smallexample
(@value{GDBP})
-var-list-children n
- numchild=@var{n},children=[@{name=@var{name},
+ ^done,numchild=@var{n},children=[@{name=@var{name},
numchild=@var{n},type=@var{type}@},@r{(repeats N times)}]
(@value{GDBP})
-var-list-children --all-values n
- numchild=@var{n},children=[@{name=@var{name},
+ ^done,numchild=@var{n},children=[@{name=@var{name},
numchild=@var{n},value=@var{value},type=@var{type}@},@r{(repeats N times)}]
@end smallexample
@subsubheading Synopsis
@smallexample
- -var-update @{@var{name} | "*"@}
+ -var-update [@var{print-values}] @{@var{name} | "*"@}
@end smallexample
Update the value of the variable object @var{name} by evaluating its
expression after fetching all the new values from memory or registers.
-A @samp{*} causes all existing variable objects to be updated.
+A @samp{*} causes all existing variable objects to be updated. The
+option @var{print-values} determines whether names both and values, or
+just names are printed in the manner described for
+@code{-var-list-children} (@pxref{-var-list-children}).
+@subsubheading Example
+
+@smallexample
+(@value{GDBP})
+-var-assign var1 3
+^done,value="3"
+(@value{GDBP})
+-var-update --all-values var1
+^done,changelist=[@{name="var1",value="3",in_scope="true",
+type_changed="false"@}]
+(@value{GDBP})
+@end smallexample
@node Annotations
@chapter @value{GDBN} Annotations
@menu
* Annotations Overview:: What annotations are; the general syntax.
-* Server Prefix:: Issuing a command without affecting user state.
* Prompting:: Annotations marking @value{GDBN}'s need for input.
* Errors:: Annotations for error messages.
* Invalidation:: Some annotations describe things now invalid.
denotes a @samp{control-z} character) are annotations; the rest is
output from @value{GDBN}.
-@node Server Prefix
-@section The Server Prefix
-@cindex server prefix for annotations
-
-To issue a command to @value{GDBN} without affecting certain aspects of
-the state which is seen by users, prefix it with @samp{server }. This
-means that this command will not affect the command history, nor will it
-affect @value{GDBN}'s notion of which command to repeat if @key{RET} is
-pressed on a line by itself.
-
-The server prefix does not affect the recording of values into the value
-history; to print a value without recording it into the value history,
-use the @code{output} command instead of the @code{print} command.
-
@node Prompting
@section Annotation for @value{GDBN} Input
version number.
@item
-What compiler (and its version) was used to compile @value{GDBN}---e.g.
+What compiler (and its version) was used to compile @value{GDBN}---e.g.@:
``@value{GCC}--2.8.1''.
@item
What compiler (and its version) was used to compile the program you are
-debugging---e.g. ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP
+debugging---e.g.@: ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP
C Compiler''. For GCC, you can say @code{gcc --version} to get this
information; for other compilers, see the documentation for those
compilers.
* Stop Reply Packets::
* General Query Packets::
* Register Packet Format::
+* Tracepoint Packets::
+* Interrupts::
* Examples::
* File-I/O remote protocol extension::
@end menu
The error response returned for some packets includes a two character
error number. That number is not well defined.
+@cindex empty response, for unsupported packets
For any @var{command} not supported by the stub, an empty response
(@samp{$#00}) should be returned. That way it is possible to extend the
protocol. A newer @value{GDBN} can tell if a packet is supported based
@xref{File-I/O remote protocol extension}, for details about the File
I/O extension of the remote protocol.
-@table @r
+Each packet's description has a template showing the packet's overall
+syntax, followed by an explanation of the packet's meaning. We
+include spaces in some of the templates for clarity; these are not
+part of the packet's syntax. No @value{GDBN} packet uses spaces to
+separate its components. For example, a template like @samp{foo
+@var{bar} @var{baz}} describes a packet beginning with the three ASCII
+bytes @samp{foo}, followed by a @var{bar}, followed directly by a
+@var{baz}. GDB does not transmit a space character between the
+@samp{foo} and the @var{bar}, or between the @var{bar} and the
+@var{baz}.
-@item @code{!} --- extended mode
-@cindex @code{!} packet
+Note that all packet forms beginning with an upper- or lower-case
+letter, other than those described here, are reserved for future use.
+Here are the packet descriptions.
+
+@table @samp
+
+@item !
+@cindex @samp{!} packet
Enable extended mode. In extended mode, the remote server is made
persistent. The @samp{R} packet is used to restart the program being
debugged.
The remote target both supports and has enabled extended mode.
@end table
-@item @code{?} --- last signal
-@cindex @code{?} packet
-
+@item ?
+@cindex @samp{?} packet
Indicate the reason the target halted. The reply is the same as for
step and continue.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{a} --- reserved
-
-Reserved for future use.
-
-@item @code{A}@var{arglen}@code{,}@var{argnum}@code{,}@var{arg}@code{,@dots{}} --- set program arguments @strong{(reserved)}
-@cindex @code{A} packet
-
-Initialized @samp{argv[]} array passed into program. @var{arglen}
-specifies the number of bytes in the hex encoded byte stream @var{arg}.
-See @code{gdbserver} for more details.
+@item A @var{arglen},@var{argnum},@var{arg},@dots{}
+@cindex @samp{A} packet
+Initialized @code{argv[]} array passed into program. @var{arglen}
+specifies the number of bytes in the hex encoded byte stream
+@var{arg}. See @code{gdbserver} for more details.
Reply:
@table @samp
@item OK
-@item E@var{NN}
+The arguments were set.
+@item E @var{NN}
+An error occurred.
@end table
-@item @code{b}@var{baud} --- set baud @strong{(deprecated)}
-@cindex @code{b} packet
-
+@item b @var{baud}
+@cindex @samp{b} packet
+(Don't use this packet; its behavior is not well-defined.)
Change the serial line speed to @var{baud}.
JTC: @emph{When does the transport layer state change? When it's
switch happen "in between" packets, so that from remote protocol's point
of view, nothing actually happened.}
-@item @code{B}@var{addr},@var{mode} --- set breakpoint @strong{(deprecated)}
-@cindex @code{B} packet
-
+@item B @var{addr},@var{mode}
+@cindex @samp{B} packet
Set (@var{mode} is @samp{S}) or clear (@var{mode} is @samp{C}) a
breakpoint at @var{addr}.
-This packet has been replaced by the @samp{Z} and @samp{z} packets
+Don't use this packet. Use the @samp{Z} and @samp{z} packets instead
(@pxref{insert breakpoint or watchpoint packet}).
-@item @code{c}@var{addr} --- continue
-@cindex @code{c} packet
-
-@var{addr} is address to resume. If @var{addr} is omitted, resume at
-current address.
+@item c @r{[}@var{addr}@r{]}
+@cindex @samp{c} packet
+Continue. @var{addr} is address to resume. If @var{addr} is omitted,
+resume at current address.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{C}@var{sig}@code{;}@var{addr} --- continue with signal
-@cindex @code{C} packet
-
+@item C @var{sig}@r{[};@var{addr}@r{]}
+@cindex @samp{C} packet
Continue with signal @var{sig} (hex signal number). If
-@code{;}@var{addr} is omitted, resume at same address.
+@samp{;@var{addr}} is omitted, resume at same address.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{d} --- toggle debug @strong{(deprecated)}
-@cindex @code{d} packet
-
+@item d
+@cindex @samp{d} packet
Toggle debug flag.
-@item @code{D} --- detach
-@cindex @code{D} packet
+Don't use this packet; instead, define a general set packet
+(@pxref{General Query Packets}).
+@item D
+@cindex @samp{D} packet
Detach @value{GDBN} from the remote system. Sent to the remote target
before @value{GDBN} disconnects via the @code{detach} command.
Reply:
@table @samp
-@item @emph{no response}
-@value{GDBN} does not check for any response after sending this packet.
+@item OK
+for success
+@item E @var{NN}
+for an error
@end table
-@item @code{e} --- reserved
-
-Reserved for future use.
-
-@item @code{E} --- reserved
-
-Reserved for future use.
-
-@item @code{f} --- reserved
-
-Reserved for future use.
-
-@item @code{F}@var{RC}@code{,}@var{EE}@code{,}@var{CF}@code{;}@var{XX} --- Reply to target's F packet.
-@cindex @code{F} packet
+@item F @var{RC},@var{EE},@var{CF};@var{XX}
+@cindex @samp{F} packet
+A reply from @value{GDBN} to an @samp{F} packet sent by the target.
+This is part of the File-I/O protocol extension. @xref{File-I/O
+remote protocol extension}, for the specification.
-This packet is send by @value{GDBN} as reply to a @code{F} request packet
-sent by the target. This is part of the File-I/O protocol extension.
-@xref{File-I/O remote protocol extension}, for the specification.
-
-@item @code{g} --- read registers
+@item g
@anchor{read registers packet}
-@cindex @code{g} packet
-
+@cindex @samp{g} packet
Read general registers.
Reply:
@item @var{XX@dots{}}
Each byte of register data is described by two hex digits. The bytes
with the register are transmitted in target byte order. The size of
-each register and their position within the @samp{g} @var{packet} are
+each register and their position within the @samp{g} packet are
determined by the @value{GDBN} internal macros
-@var{DEPRECATED_REGISTER_RAW_SIZE} and @var{REGISTER_NAME} macros. The
-specification of several standard @code{g} packets is specified below.
-@item E@var{NN}
+@code{DEPRECATED_REGISTER_RAW_SIZE} and @code{REGISTER_NAME} macros. The
+specification of several standard @samp{g} packets is specified below.
+@item E @var{NN}
for an error.
@end table
-@item @code{G}@var{XX@dots{}} --- write regs
-@cindex @code{G} packet
-
-@xref{read registers packet}, for a description of the @var{XX@dots{}}
-data.
+@item G @var{XX@dots{}}
+@cindex @samp{G} packet
+Write general registers. @xref{read registers packet}, for a
+description of the @var{XX@dots{}} data.
Reply:
@table @samp
@item OK
for success
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{h} --- reserved
-
-Reserved for future use.
-
-@item @code{H}@var{c}@var{t@dots{}} --- set thread
-@cindex @code{H} packet
-
+@item H @var{c} @var{t}
+@cindex @samp{H} packet
Set thread for subsequent operations (@samp{m}, @samp{M}, @samp{g},
@samp{G}, et.al.). @var{c} depends on the operation to be performed: it
should be @samp{c} for step and continue operations, @samp{g} for other
-operations. The thread designator @var{t@dots{}} may be -1, meaning all
-the threads, a thread number, or zero which means pick any thread.
+operations. The thread designator @var{t} may be @samp{-1}, meaning all
+the threads, a thread number, or @samp{0} which means pick any thread.
Reply:
@table @samp
@item OK
for success
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
@c selected, sets the registers of the register block of
@c that thread; otherwise sets current registers.
-@item @code{i}@var{addr}@code{,}@var{nnn} --- cycle step @strong{(draft)}
+@item i @r{[}@var{addr}@r{[},@var{nnn}@r{]]}
@anchor{cycle step packet}
-@cindex @code{i} packet
-
-Step the remote target by a single clock cycle. If @code{,}@var{nnn} is
+@cindex @samp{i} packet
+Step the remote target by a single clock cycle. If @samp{,@var{nnn}} is
present, cycle step @var{nnn} cycles. If @var{addr} is present, cycle
step starting at that address.
-@item @code{I} --- signal then cycle step @strong{(reserved)}
-@cindex @code{I} packet
-
-@xref{step with signal packet}. @xref{cycle step packet}.
-
-@item @code{j} --- reserved
-
-Reserved for future use.
-
-@item @code{J} --- reserved
-
-Reserved for future use.
+@item I
+@cindex @samp{I} packet
+Signal, then cycle step. @xref{step with signal packet}. @xref{cycle
+step packet}.
-@item @code{k} --- kill request
-@cindex @code{k} packet
+@item k
+@cindex @samp{k} packet
+Kill request.
FIXME: @emph{There is no description of how to operate when a specific
thread context has been selected (i.e.@: does 'k' kill only that
thread?)}.
-@item @code{K} --- reserved
-
-Reserved for future use.
-
-@item @code{l} --- reserved
-
-Reserved for future use.
-
-@item @code{L} --- reserved
-
-Reserved for future use.
-
-@item @code{m}@var{addr}@code{,}@var{length} --- read memory
-@cindex @code{m} packet
-
+@item m @var{addr},@var{length}
+@cindex @samp{m} packet
Read @var{length} bytes of memory starting at address @var{addr}.
-Neither @value{GDBN} nor the stub assume that sized memory transfers are
-assumed using word aligned accesses. FIXME: @emph{A word aligned memory
-transfer mechanism is needed.}
+Note that @var{addr} may not be aligned to any particular boundary.
+
+The stub need not use any particular size or alignment when gathering
+data from memory for the response; even if @var{addr} is word-aligned
+and @var{length} is a multiple of the word size, the stub is free to
+use byte accesses, or not. For this reason, this packet may not be
+suitable for accessing memory-mapped I/O devices.
+@cindex alignment of remote memory accesses
+@cindex size of remote memory accesses
+@cindex memory, alignment and size of remote accesses
Reply:
@table @samp
@item @var{XX@dots{}}
-@var{XX@dots{}} is mem contents. Can be fewer bytes than requested if able
-to read only part of the data. Neither @value{GDBN} nor the stub assume
-that sized memory transfers are assumed using word aligned
-accesses. FIXME: @emph{A word aligned memory transfer mechanism is
-needed.}
-@item E@var{NN}
+Memory contents; each byte is transmitted as a two-digit hexidecimal
+number. The reply may contain fewer bytes than requested if the
+server was able to read only part of the region of memory.
+@item E @var{NN}
@var{NN} is errno
@end table
-@item @code{M}@var{addr},@var{length}@code{:}@var{XX@dots{}} --- write mem
-@cindex @code{M} packet
-
+@item M @var{addr},@var{length}:@var{XX@dots{}}
+@cindex @samp{M} packet
Write @var{length} bytes of memory starting at address @var{addr}.
-@var{XX@dots{}} is the data.
+@var{XX@dots{}} is the data; each byte is transmitted as a two-digit
+hexidecimal number.
Reply:
@table @samp
@item OK
for success
-@item E@var{NN}
+@item E @var{NN}
for an error (this includes the case where only part of the data was
written).
@end table
-@item @code{n} --- reserved
-
-Reserved for future use.
-
-@item @code{N} --- reserved
-
-Reserved for future use.
-
-@item @code{o} --- reserved
-
-Reserved for future use.
-
-@item @code{O} --- reserved
-
-@item @code{p}@var{hex number of register} --- read register packet
-@cindex @code{p} packet
-
+@item p @var{n}
+@cindex @samp{p} packet
+Read the value of register @var{n}; @var{n} is in hex.
@xref{read registers packet}, for a description of how the returned
register value is encoded.
@table @samp
@item @var{XX@dots{}}
the register's value
-@item E@var{NN}
+@item E @var{NN}
for an error
@item
Indicating an unrecognized @var{query}.
@end table
-@item @code{P}@var{n@dots{}}@code{=}@var{r@dots{}} --- write register
+@item P @var{n@dots{}}=@var{r@dots{}}
@anchor{write register packet}
-@cindex @code{P} packet
-
-Write register @var{n@dots{}} with value @var{r@dots{}}, which contains two hex
+@cindex @samp{P} packet
+Write register @var{n@dots{}} with value @var{r@dots{}}. The register
+number @var{n} is in hexidecimal, and @var{r@dots{}} contains two hex
digits for each byte in the register (target byte order).
Reply:
@table @samp
@item OK
for success
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{q}@var{query} --- general query
-@anchor{general query packet}
-@cindex @code{q} packet
-
-Request info about @var{query}. In general @value{GDBN} queries have a
-leading upper case letter. Custom vendor queries should use a company
-prefix (in lower case) ex: @samp{qfsf.var}. @var{query} may optionally
-be followed by a @samp{,} or @samp{;} separated list. Stubs must ensure
-that they match the full @var{query} name.
-
-Reply:
-@table @samp
-@item @var{XX@dots{}}
-Hex encoded data from query. The reply can not be empty.
-@item E@var{NN}
-error reply
-@item
-Indicating an unrecognized @var{query}.
-@end table
-
-@item @code{Q}@var{var}@code{=}@var{val} --- general set
-@cindex @code{Q} packet
-
-Set value of @var{var} to @var{val}.
-
-@xref{general query packet}, for a discussion of naming conventions.
-
-@item @code{r} --- reset @strong{(deprecated)}
-@cindex @code{r} packet
+@item q @var{name} @var{params}@dots{}
+@itemx Q @var{name} @var{params}@dots{}
+@cindex @samp{q} packet
+@cindex @samp{Q} packet
+General query (@samp{q}) and set (@samp{Q}). These packets are
+described fully in @ref{General Query Packets}.
+@item r
+@cindex @samp{r} packet
Reset the entire system.
-@item @code{R}@var{XX} --- remote restart
-@cindex @code{R} packet
+Don't use this packet; use the @samp{R} packet instead.
+@item R @var{XX}
+@cindex @samp{R} packet
Restart the program being debugged. @var{XX}, while needed, is ignored.
This packet is only available in extended mode.
-Reply:
-@table @samp
-@item @emph{no reply}
The @samp{R} packet has no reply.
-@end table
-
-@item @code{s}@var{addr} --- step
-@cindex @code{s} packet
-@var{addr} is address to resume. If @var{addr} is omitted, resume at
-same address.
+@item s @r{[}@var{addr}@r{]}
+@cindex @samp{s} packet
+Single step. @var{addr} is the address at which to resume. If
+@var{addr} is omitted, resume at same address.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{S}@var{sig}@code{;}@var{addr} --- step with signal
+@item S @var{sig}@r{[};@var{addr}@r{]}
@anchor{step with signal packet}
-@cindex @code{S} packet
-
-Like @samp{C} but step not continue.
+@cindex @samp{S} packet
+Step with signal. This is analogous to the @samp{C} packet, but
+requests a single-step, rather than a normal resumption of execution.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{t}@var{addr}@code{:}@var{PP}@code{,}@var{MM} --- search
-@cindex @code{t} packet
-
+@item t @var{addr}:@var{PP},@var{MM}
+@cindex @samp{t} packet
Search backwards starting at address @var{addr} for a match with pattern
@var{PP} and mask @var{MM}. @var{PP} and @var{MM} are 4 bytes.
@var{addr} must be at least 3 digits.
-@item @code{T}@var{XX} --- thread alive
-@cindex @code{T} packet
-
+@item T @var{XX}
+@cindex @samp{T} packet
Find out if the thread XX is alive.
Reply:
@table @samp
@item OK
thread is still alive
-@item E@var{NN}
+@item E @var{NN}
thread is dead
@end table
-@item @code{u} --- reserved
-
-Reserved for future use.
-
-@item @code{U} --- reserved
-
-Reserved for future use.
-
-@item @code{v} --- verbose packet prefix
-
-Packets starting with @code{v} are identified by a multi-letter name,
-up to the first @code{;} or @code{?} (or the end of the packet).
-
-@item @code{vCont}[;@var{action}[@code{:}@var{tid}]]... --- extended resume
-@cindex @code{vCont} packet
+@item v
+Packets starting with @samp{v} are identified by a multi-letter name,
+up to the first @samp{;} or @samp{?} (or the end of the packet).
-Resume the inferior. Different actions may be specified for each thread.
+@item vCont@r{[};@var{action}@r{[}:@var{tid}@r{]]}@dots{}
+@cindex @samp{vCont} packet
+Resume the inferior, specifying different actions for each thread.
If an action is specified with no @var{tid}, then it is applied to any
threads that don't have a specific action specified; if no default action is
specified then other threads should remain stopped. Specifying multiple
default actions is an error; specifying no actions is also an error.
Thread IDs are specified in hexadecimal. Currently supported actions are:
-@table @code
+@table @samp
@item c
Continue.
-@item C@var{sig}
+@item C @var{sig}
Continue with signal @var{sig}. @var{sig} should be two hex digits.
@item s
Step.
-@item S@var{sig}
+@item S @var{sig}
Step with signal @var{sig}. @var{sig} should be two hex digits.
@end table
The optional @var{addr} argument normally associated with these packets is
-not supported in @code{vCont}.
+not supported in @samp{vCont}.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item @code{vCont?} --- extended resume query
-@cindex @code{vCont?} packet
-
-Query support for the @code{vCont} packet.
+@item vCont?
+@cindex @samp{vCont?} packet
+Request a list of actions supporetd by the @samp{vCont} packet.
Reply:
@table @samp
-@item @code{vCont}[;@var{action}]...
-The @code{vCont} packet is supported. Each @var{action} is a supported
-command in the @code{vCont} packet.
+@item vCont@r{[};@var{action}@dots{}@r{]}
+The @samp{vCont} packet is supported. Each @var{action} is a supported
+command in the @samp{vCont} packet.
@item
-The @code{vCont} packet is not supported.
+The @samp{vCont} packet is not supported.
@end table
-@item @code{V} --- reserved
-
-Reserved for future use.
-
-@item @code{w} --- reserved
-
-Reserved for future use.
-
-@item @code{W} --- reserved
-
-Reserved for future use.
-
-@item @code{x} --- reserved
-
-Reserved for future use.
-
-@item @code{X}@var{addr}@code{,}@var{length}@var{:}@var{XX@dots{}} --- write mem (binary)
-@cindex @code{X} packet
-
-@var{addr} is address, @var{length} is number of bytes, @var{XX@dots{}}
-is binary data. The characters @code{$}, @code{#}, and @code{0x7d} are
-escaped using @code{0x7d}, and then XORed with @code{0x20}.
-For example, @code{0x7d} would be transmitted as @code{0x7d 0x5d}.
+@item X @var{addr},@var{length}:@var{XX@dots{}}
+@anchor{X packet}
+@cindex @samp{X} packet
+Write data to memory, where the data is transmitted in binary.
+@var{addr} is address, @var{length} is number of bytes,
+@samp{@var{XX}@dots{}} is binary data. The bytes @code{0x23}
+(@sc{ascii} @samp{#}), @code{0x24} (@sc{ascii} @samp{$}), and
+@code{0x7d} (@sc{ascii} @samp{@}}) are escaped using @code{0x7d}
+(@sc{ascii} @samp{@}}), and then XORed with @code{0x20}. For example,
+the byte @code{0x7d} would be transmitted as the two bytes @code{0x7d
+0x5d}.
Reply:
@table @samp
@item OK
for success
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{y} --- reserved
-
-Reserved for future use.
-
-@item @code{Y} reserved
-
-Reserved for future use.
-
-@item @code{z}@var{type}@code{,}@var{addr}@code{,}@var{length} --- remove breakpoint or watchpoint @strong{(draft)}
-@itemx @code{Z}@var{type}@code{,}@var{addr}@code{,}@var{length} --- insert breakpoint or watchpoint @strong{(draft)}
+@item z @var{type},@var{addr},@var{length}
+@itemx Z @var{type},@var{addr},@var{length}
@anchor{insert breakpoint or watchpoint packet}
-@cindex @code{z} packet
-@cindex @code{Z} packets
-
-Insert (@code{Z}) or remove (@code{z}) a @var{type} breakpoint or
+@cindex @samp{z} packet
+@cindex @samp{Z} packets
+Insert (@samp{Z}) or remove (@samp{z}) a @var{type} breakpoint or
watchpoint starting at address @var{address} and covering the next
@var{length} bytes.
@emph{Implementation notes: A remote target shall return an empty string
for an unrecognized breakpoint or watchpoint packet @var{type}. A
remote target shall support either both or neither of a given
-@code{Z}@var{type}@dots{} and @code{z}@var{type}@dots{} packet pair. To
+@samp{Z@var{type}@dots{}} and @samp{z@var{type}@dots{}} packet pair. To
avoid potential problems with duplicate packets, the operations should
be implemented in an idempotent way.}
-@item @code{z}@code{0}@code{,}@var{addr}@code{,}@var{length} --- remove memory breakpoint @strong{(draft)}
-@item @code{Z}@code{0}@code{,}@var{addr}@code{,}@var{length} --- insert memory breakpoint @strong{(draft)}
-@cindex @code{z0} packet
-@cindex @code{Z0} packet
-
-Insert (@code{Z0}) or remove (@code{z0}) a memory breakpoint at address
-@code{addr} of size @code{length}.
+@item z0,@var{addr},@var{length}
+@itemx Z0,@var{addr},@var{length}
+@cindex @samp{z0} packet
+@cindex @samp{Z0} packet
+Insert (@samp{Z0}) or remove (@samp{z0}) a memory breakpoint at address
+@var{addr} of size @var{length}.
A memory breakpoint is implemented by replacing the instruction at
@var{addr} with a software breakpoint or trap instruction. The
-@code{length} is used by targets that indicates the size of the
+@var{length} is used by targets that indicates the size of the
breakpoint (in bytes) that should be inserted (e.g., the @sc{arm} and
@sc{mips} can insert either a 2 or 4 byte breakpoint).
success
@item
not supported
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{z}@code{1}@code{,}@var{addr}@code{,}@var{length} --- remove hardware breakpoint @strong{(draft)}
-@item @code{Z}@code{1}@code{,}@var{addr}@code{,}@var{length} --- insert hardware breakpoint @strong{(draft)}
-@cindex @code{z1} packet
-@cindex @code{Z1} packet
-
-Insert (@code{Z1}) or remove (@code{z1}) a hardware breakpoint at
-address @code{addr} of size @code{length}.
+@item z1,@var{addr},@var{length}
+@itemx Z1,@var{addr},@var{length}
+@cindex @samp{z1} packet
+@cindex @samp{Z1} packet
+Insert (@samp{Z1}) or remove (@samp{z1}) a hardware breakpoint at
+address @var{addr} of size @var{length}.
A hardware breakpoint is implemented using a mechanism that is not
dependant on being able to modify the target's memory.
success
@item
not supported
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{z}@code{2}@code{,}@var{addr}@code{,}@var{length} --- remove write watchpoint @strong{(draft)}
-@item @code{Z}@code{2}@code{,}@var{addr}@code{,}@var{length} --- insert write watchpoint @strong{(draft)}
-@cindex @code{z2} packet
-@cindex @code{Z2} packet
-
-Insert (@code{Z2}) or remove (@code{z2}) a write watchpoint.
+@item z2,@var{addr},@var{length}
+@itemx Z2,@var{addr},@var{length}
+@cindex @samp{z2} packet
+@cindex @samp{Z2} packet
+Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint.
Reply:
@table @samp
success
@item
not supported
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{z}@code{3}@code{,}@var{addr}@code{,}@var{length} --- remove read watchpoint @strong{(draft)}
-@item @code{Z}@code{3}@code{,}@var{addr}@code{,}@var{length} --- insert read watchpoint @strong{(draft)}
-@cindex @code{z3} packet
-@cindex @code{Z3} packet
-
-Insert (@code{Z3}) or remove (@code{z3}) a read watchpoint.
+@item z3,@var{addr},@var{length}
+@itemx Z3,@var{addr},@var{length}
+@cindex @samp{z3} packet
+@cindex @samp{Z3} packet
+Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint.
Reply:
@table @samp
success
@item
not supported
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
-@item @code{z}@code{4}@code{,}@var{addr}@code{,}@var{length} --- remove access watchpoint @strong{(draft)}
-@item @code{Z}@code{4}@code{,}@var{addr}@code{,}@var{length} --- insert access watchpoint @strong{(draft)}
-@cindex @code{z4} packet
-@cindex @code{Z4} packet
-
-Insert (@code{Z4}) or remove (@code{z4}) an access watchpoint.
+@item z4,@var{addr},@var{length}
+@itemx Z4,@var{addr},@var{length}
+@cindex @samp{z4} packet
+@cindex @samp{Z4} packet
+Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint.
Reply:
@table @samp
success
@item
not supported
-@item E@var{NN}
+@item E @var{NN}
for an error
@end table
The @samp{C}, @samp{c}, @samp{S}, @samp{s} and @samp{?} packets can
receive any of the below as a reply. In the case of the @samp{C},
@samp{c}, @samp{S} and @samp{s} packets, that reply is only returned
-when the target halts. In the below the exact meaning of @samp{signal
-number} is poorly defined. In general one of the UNIX signal numbering
-conventions is used.
-
-@table @samp
+when the target halts. In the below the exact meaning of @dfn{signal
+number} is poorly defined. In general one of the UNIX signal
+numbering conventions is used.
-@item S@var{AA}
-@var{AA} is the signal number
+As in the description of request packets, we include spaces in the
+reply templates for clarity; these are not part of the reply packet's
+syntax. No @value{GDBN} stop reply packet uses spaces to separate its
+components.
-@item @code{T}@var{AA}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;}@var{n...}@code{:}@var{r...}@code{;}
-@cindex @code{T} packet reply
+@table @samp
-@var{AA} = two hex digit signal number; @var{n...} = register number
-(hex), @var{r...} = target byte ordered register contents, size defined
-by @code{DEPRECATED_REGISTER_RAW_SIZE}; @var{n...} = @samp{thread},
-@var{r...} = thread process ID, this is a hex integer; @var{n...} =
-(@samp{watch} | @samp{rwatch} | @samp{awatch}, @var{r...} = data
-address, this is a hex integer; @var{n...} = other string not starting
-with valid hex digit. @value{GDBN} should ignore this @var{n...},
-@var{r...} pair and go on to the next. This way we can extend the
-protocol.
+@item S @var{AA}
+The program received signal number @var{AA} (a two-digit hexidecimal
+number).
-@item W@var{AA}
+@item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{}
+@cindex @samp{T} packet reply
+The program received signal number @var{AA} (a two-digit hexidecimal
+number). Single-step and breakpoint traps are reported this way. The
+@samp{@var{n}:@var{r}} pairs give the values of important registers or
+other information:
+@enumerate
+@item
+If @var{n} is a hexidecimal number, it is a register number, and the
+corresponding @var{r} gives that register's value. @var{r} is a
+series of bytes in target byte order, with each byte given by a
+two-digit hex number.
+@item
+If @var{n} is @samp{thread}, then @var{r} is the thread process ID, in
+hex.
+@item
+If @var{n} is @samp{watch}, @samp{rwatch}, or @samp{awatch}, then the
+packet indicates a watchpoint hit, and @var{r} is the data address, in
+hex.
+@item
+Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair
+and go on to the next; this allows us to extend the protocol in the
+future.
+@end enumerate
+@item W @var{AA}
The process exited, and @var{AA} is the exit status. This is only
applicable to certain targets.
-@item X@var{AA}
-
+@item X @var{AA}
The process terminated with signal @var{AA}.
-@item O@var{XX@dots{}}
-
-@var{XX@dots{}} is hex encoding of @sc{ascii} data. This can happen at
-any time while the program is running and the debugger should continue
-to wait for @samp{W}, @samp{T}, etc.
-
-@item F@var{call-id}@code{,}@var{parameter@dots{}}
+@item O @var{XX}@dots{}
+@samp{@var{XX}@dots{}} is hex encoding of @sc{ascii} data, to be
+written as the program's console output. This can happen at any time
+while the program is running and the debugger should continue to wait
+for @samp{W}, @samp{T}, etc.
+@item F @var{call-id},@var{parameter}@dots{}
@var{call-id} is the identifier which says which host system call should
be called. This is just the name of the function. Translation into the
correct system call is only applicable as it's defined in @value{GDBN}.
@xref{File-I/O remote protocol extension}, for a list of implemented
system calls.
-@var{parameter@dots{}} is a list of parameters as defined for this very
-system call.
+@samp{@var{parameter}@dots{}} is a list of parameters as defined for
+this very system call.
-The target replies with this packet when it expects @value{GDBN} to call
-a host system call on behalf of the target. @value{GDBN} replies with
-an appropriate @code{F} packet and keeps up waiting for the next reply
-packet from the target. The latest @samp{C}, @samp{c}, @samp{S} or
-@samp{s} action is expected to be continued.
-@xref{File-I/O remote protocol extension}, for more details.
+The target replies with this packet when it expects @value{GDBN} to
+call a host system call on behalf of the target. @value{GDBN} replies
+with an appropriate @samp{F} packet and keeps up waiting for the next
+reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S}
+or @samp{s} action is expected to be continued. @xref{File-I/O remote
+protocol extension}, for more details.
@end table
@section General Query Packets
@cindex remote query requests
-The following set and query packets have already been defined.
+Packets starting with @samp{q} are @dfn{general query packets};
+packets starting with @samp{Q} are @dfn{general set packets}. General
+query and set packets are a semi-unified form for retrieving and
+sending information to and from the stub.
-@table @r
+The initial letter of a query or set packet is followed by a name
+indicating what sort of thing the packet applies to. For example,
+@value{GDBN} may use a @samp{qSymbol} packet to exchange symbol
+definitions with the stub. These packet names follow some
+conventions:
+
+@itemize @bullet
+@item
+The name must not contain commas, colons or semicolons.
+@item
+Most @value{GDBN} query and set packets have a leading upper case
+letter.
+@item
+The names of custom vendor packets should use a company prefix, in
+lower case, followed by a period. For example, packets designed at
+the Acme Corporation might begin with @samp{qacme.foo} (for querying
+foos) or @samp{Qacme.bar} (for setting bars).
+@end itemize
+
+A query or set packet may optionally be followed by a @samp{,} or
+@samp{;} separated list. Stubs must be careful to match the full
+packet name, in case packet names have common prefixes.
+
+Like the descriptions of the other packets, each description here
+has a template showing the packet's overall syntax, followed by an
+explanation of the packet's meaning. We include spaces in some of the
+templates for clarity; these are not part of the packet's syntax. No
+@value{GDBN} packet uses spaces to separate its components.
+
+Here are the currently defined query and set packets:
-@item @code{q}@code{C} --- current thread
+@table @samp
+
+@item qC
@cindex current thread, remote request
-@cindex @code{qC} packet
+@cindex @samp{qC} packet
Return the current thread id.
Reply:
@table @samp
-@item @code{QC}@var{pid}
+@item QC @var{pid}
Where @var{pid} is an unsigned hexidecimal process id.
-@item *
+@item @r{(anything else)}
Any other reply implies the old pid.
@end table
-@item @code{q}@code{fThreadInfo} -- all thread ids
-@cindex list active threads, remote request
-@cindex @code{qfThreadInfo} packet
-@code{q}@code{sThreadInfo}
+@item qCRC:@var{addr},@var{length}
+@cindex CRC of memory block, remote request
+@cindex @samp{qCRC} packet
+Compute the CRC checksum of a block of memory.
+Reply:
+@table @samp
+@item E @var{NN}
+An error (such as memory fault)
+@item C @var{crc32}
+The specified memory region's checksum is @var{crc32}.
+@end table
-Obtain a list of active thread ids from the target (OS). Since there
+@item qfThreadInfo
+@itemx qsThreadInfo
+@cindex list active threads, remote request
+@cindex @samp{qfThreadInfo} packet
+@cindex @samp{qsThreadInfo} packet
+Obtain a list of all active thread ids from the target (OS). Since there
may be too many active threads to fit into one reply packet, this query
works iteratively: it may require more than one query/reply sequence to
obtain the entire list of threads. The first query of the sequence will
-be the @code{qf}@code{ThreadInfo} query; subsequent queries in the
-sequence will be the @code{qs}@code{ThreadInfo} query.
+be the @samp{qfThreadInfo} query; subsequent queries in the
+sequence will be the @samp{qsThreadInfo} query.
-NOTE: replaces the @code{qL} query (see below).
+NOTE: This packet replaces the @samp{qL} query (see below).
Reply:
@table @samp
-@item @code{m}@var{id}
+@item m @var{id}
A single thread id
-@item @code{m}@var{id},@var{id}@dots{}
+@item m @var{id},@var{id}@dots{}
a comma-separated list of thread ids
-@item @code{l}
-(lower case 'el') denotes end of list.
+@item l
+(lower case letter @samp{L}) denotes end of list.
@end table
In response to each query, the target will reply with a list of one or
more thread ids, in big-endian unsigned hex, separated by commas.
@value{GDBN} will respond to each reply with a request for more thread
-ids (using the @code{qs} form of the query), until the target responds
-with @code{l} (lower-case el, for @code{'last'}).
+ids (using the @samp{qs} form of the query), until the target responds
+with @samp{l} (lower-case el, for @dfn{last}).
-@item @code{q}@code{ThreadExtraInfo}@code{,}@var{id} --- extra thread info
-@cindex thread attributes info, remote request
-@cindex @code{qThreadExtraInfo} packet
-Where @var{id} is a thread-id in big-endian hex. Obtain a printable
-string description of a thread's attributes from the target OS. This
-string may contain anything that the target OS thinks is interesting for
-@value{GDBN} to tell the user about the thread. The string is displayed
-in @value{GDBN}'s @samp{info threads} display. Some examples of
-possible thread extra info strings are ``Runnable'', or ``Blocked on
-Mutex''.
+@item qGetTLSAddr:@var{thread-id},@var{offset},@var{lm}
+@cindex get thread-local storage address, remote request
+@cindex @samp{qGetTLSAddr} packet
+Fetch the address associated with thread local storage specified
+by @var{thread-id}, @var{offset}, and @var{lm}.
+
+@var{thread-id} is the (big endian, hex encoded) thread id associated with the
+thread for which to fetch the TLS address.
+
+@var{offset} is the (big endian, hex encoded) offset associated with the
+thread local variable. (This offset is obtained from the debug
+information associated with the variable.)
+
+@var{lm} is the (big endian, hex encoded) OS/ABI specific encoding of the
+the load module associated with the thread local storage. For example,
+a @sc{gnu}/Linux system will pass the link map address of the shared
+object associated with the thread local storage under consideration.
+Other operating environments may choose to represent the load module
+differently, so the precise meaning of this parameter will vary.
Reply:
@table @samp
-@item @var{XX@dots{}}
-Where @var{XX@dots{}} is a hex encoding of @sc{ascii} data, comprising
-the printable string containing the extra information about the thread's
-attributes.
+@item @var{XX}@dots{}
+Hex encoded (big endian) bytes representing the address of the thread
+local storage requested.
+
+@item E @var{nn}
+An error occurred. @var{nn} are hex digits.
+
+@item
+An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub.
@end table
-@item @code{q}@code{L}@var{startflag}@var{threadcount}@var{nextthread} --- query @var{LIST} or @var{threadLIST} @strong{(deprecated)}
+Use of this request packet is controlled by the @code{set remote
+get-thread-local-storage-address} command (@pxref{Remote
+configuration, set remote get-thread-local-storage-address}).
+@item qL @var{startflag} @var{threadcount} @var{nextthread}
Obtain thread information from RTOS. Where: @var{startflag} (one hex
digit) is one to indicate the first query and zero to indicate a
subsequent query; @var{threadcount} (two hex digits) is the maximum
(eight hex digits), for subsequent queries (@var{startflag} is zero), is
returned in the response as @var{argthread}.
-NOTE: this query is replaced by the @code{q}@code{fThreadInfo} query
-(see above).
+Don't use this packet; use the @samp{qfThreadInfo} query instead (see above).
Reply:
@table @samp
-@item @code{q}@code{M}@var{count}@var{done}@var{argthread}@var{thread@dots{}}
+@item qM @var{count} @var{done} @var{argthread} @var{thread}@dots{}
Where: @var{count} (two hex digits) is the number of threads being
returned; @var{done} (one hex digit) is zero to indicate more threads
and one indicates no further threads; @var{argthreadid} (eight hex
-digits) is @var{nextthread} from the request packet; @var{thread@dots{}}
+digits) is @var{nextthread} from the request packet; @var{thread}@dots{}
is a sequence of thread IDs from the target. @var{threadid} (eight hex
digits). See @code{remote.c:parse_threadlist_response()}.
@end table
-@item @code{q}@code{CRC:}@var{addr}@code{,}@var{length} --- compute CRC of memory block
-@cindex CRC of memory block, remote request
-@cindex @code{qCRC} packet
-Reply:
-@table @samp
-@item @code{E}@var{NN}
-An error (such as memory fault)
-@item @code{C}@var{CRC32}
-A 32 bit cyclic redundancy check of the specified memory region.
-@end table
-
-@item @code{q}@code{Offsets} --- query sect offs
+@item qOffsets
@cindex section offsets, remote request
-@cindex @code{qOffsets} packet
+@cindex @samp{qOffsets} packet
Get section offsets that the target used when re-locating the downloaded
image. @emph{Note: while a @code{Bss} offset is included in the
response, @value{GDBN} ignores this and instead applies the @code{Data}
Reply:
@table @samp
-@item @code{Text=}@var{xxx}@code{;Data=}@var{yyy}@code{;Bss=}@var{zzz}
+@item Text=@var{xxx};Data=@var{yyy};Bss=@var{zzz}
@end table
-@item @code{q}@code{P}@var{mode}@var{threadid} --- thread info request
+@item qP @var{mode} @var{threadid}
@cindex thread information, remote request
-@cindex @code{qP} packet
+@cindex @samp{qP} packet
Returns information on @var{threadid}. Where: @var{mode} is a hex
encoded 32 bit mode; @var{threadid} is a hex encoded 64 bit thread ID.
-Reply:
-@table @samp
-@item *
-@end table
+Reply: see @code{remote.c:remote_unpack_thread_info_response()}.
-See @code{remote.c:remote_unpack_thread_info_response()}.
-
-@item @code{q}@code{Rcmd,}@var{command} --- remote command
-@cindex execute remote command, remote request
-@cindex @code{qRcmd} packet
-@var{command} (hex encoded) is passed to the local interpreter for
-execution. Invalid commands should be reported using the output string.
-Before the final result packet, the target may also respond with a
-number of intermediate @code{O}@var{output} console output packets.
-@emph{Implementors should note that providing access to a stubs's
-interpreter may have security implications}.
-
-Reply:
-@table @samp
-@item OK
-A command response with no output.
-@item @var{OUTPUT}
-A command response with the hex encoded output string @var{OUTPUT}.
-@item @code{E}@var{NN}
-Indicate a badly formed request.
-@item @samp{}
-When @samp{q}@samp{Rcmd} is not recognized.
-@end table
-z
-@item @code{qSymbol::} --- symbol lookup
-@cindex symbol lookup, remote request
-@cindex @code{qSymbol} packet
-Notify the target that @value{GDBN} is prepared to serve symbol lookup
-requests. Accept requests from the target for the values of symbols.
-
-Reply:
-@table @samp
-@item @code{OK}
-The target does not need to look up any (more) symbols.
-@item @code{qSymbol:}@var{sym_name}
-The target requests the value of symbol @var{sym_name} (hex encoded).
-@value{GDBN} may provide the value by using the
-@code{qSymbol:}@var{sym_value}:@var{sym_name} message, described below.
-@end table
-
-@item @code{qSymbol:}@var{sym_value}:@var{sym_name} --- symbol value
-
-Set the value of @var{sym_name} to @var{sym_value}.
-
-@var{sym_name} (hex encoded) is the name of a symbol whose value the
-target has previously requested.
-
-@var{sym_value} (hex) is the value for symbol @var{sym_name}. If
-@value{GDBN} cannot supply a value for @var{sym_name}, then this field
-will be empty.
-
-Reply:
-@table @samp
-@item @code{OK}
-The target does not need to look up any (more) symbols.
-@item @code{qSymbol:}@var{sym_name}
-The target requests the value of a new symbol @var{sym_name} (hex
-encoded). @value{GDBN} will continue to supply the values of symbols
-(if available), until the target ceases to request them.
-@end table
-
-@item @code{qPart}:@var{object}:@code{read}:@var{annex}:@var{offset},@var{length} --- read special data
+@item qPart:@var{object}:read:@var{annex}:@var{offset},@var{length}
@cindex read special object, remote request
-@cindex @code{qPart} packet
+@cindex @samp{qPart} packet
Read uninterpreted bytes from the target's special data area
-identified by the keyword @code{object}.
-Request @var{length} bytes starting at @var{offset} bytes into the data.
-The content and encoding of @var{annex} is specific to the object;
-it can supply additional details about what data to access.
+identified by the keyword @var{object}. Request @var{length} bytes
+starting at @var{offset} bytes into the data. The content and
+encoding of @var{annex} is specific to the object; it can supply
+additional details about what data to access.
-Here are the specific requests of this form defined so far.
-All @samp{@code{qPart}:@var{object}:@code{read}:@dots{}}
-requests use the same reply formats, listed below.
+Here are the specific requests of this form defined so far. All
+@samp{qPart:@var{object}:read:@dots{}} requests use the same reply
+formats, listed below.
-@table @asis
-@item @code{qPart}:@code{auxv}:@code{read}::@var{offset},@var{length}
+@table @samp
+@item qPart:auxv:read::@var{offset},@var{length}
Access the target's @dfn{auxiliary vector}. @xref{OS Information,
auxiliary vector}, and see @ref{Remote configuration,
read-aux-vector-packet}. Note @var{annex} must be empty.
@end table
Reply:
-@table @asis
-@item @code{OK}
+@table @samp
+@item OK
The @var{offset} in the request is at the end of the data.
There is no more data to be read.
-@item @var{XX@dots{}}
+@item @var{XX}@dots{}
Hex encoded data bytes read.
This may be fewer bytes than the @var{length} in the request.
-@item @code{E00}
+@item E00
The request was malformed, or @var{annex} was invalid.
-@item @code{E}@var{nn}
+@item E @var{nn}
The offset was invalid, or there was an error encountered reading the data.
@var{nn} is a hex-encoded @code{errno} value.
-@item @code{""} (empty)
+@item
An empty reply indicates the @var{object} or @var{annex} string was not
recognized by the stub.
@end table
-@item @code{qPart}:@var{object}:@code{write}:@var{annex}:@var{offset}:@var{data@dots{}}
+@item qPart:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{}
@cindex write data into object, remote request
Write uninterpreted bytes into the target's special data area
-identified by the keyword @code{object},
-starting at @var{offset} bytes into the data.
-@var{data@dots{}} is the hex-encoded data to be written.
-The content and encoding of @var{annex} is specific to the object;
-it can supply additional details about what data to access.
+identified by the keyword @var{object}, starting at @var{offset} bytes
+into the data. @samp{@var{data}@dots{}} is the hex-encoded data to be
+written. The content and encoding of @var{annex} is specific to the
+object; it can supply additional details about what data to access.
No requests of this form are presently in use. This specification
serves as a placeholder to document the common format that new
specific request specifications ought to use.
Reply:
-@table @asis
+@table @samp
@item @var{nn}
@var{nn} (hex encoded) is the number of bytes written.
This may be fewer bytes than supplied in the request.
-@item @code{E00}
+@item E00
The request was malformed, or @var{annex} was invalid.
-@item @code{E}@var{nn}
+@item E @var{nn}
The offset was invalid, or there was an error encountered writing the data.
@var{nn} is a hex-encoded @code{errno} value.
-@item @code{""} (empty)
+@item
An empty reply indicates the @var{object} or @var{annex} string was not
recognized by the stub, or that the object does not support writing.
@end table
-@item @code{qPart}:@var{object}:@var{operation}:@dots{}
+@item qPart:@var{object}:@var{operation}:@dots{}
Requests of this form may be added in the future. When a stub does
not recognize the @var{object} keyword, or its support for
-@var{object} does not recognize the @var{operation} keyword,
-the stub must respond with an empty packet.
+@var{object} does not recognize the @var{operation} keyword, the stub
+must respond with an empty packet.
-@item @code{qGetTLSAddr}:@var{thread-id},@var{offset},@var{lm} --- get thread local storage address
-@cindex get thread-local storage address, remote request
-@cindex @code{qGetTLSAddr} packet
-Fetch the address associated with thread local storage specified
-by @var{thread-id}, @var{offset}, and @var{lm}.
+@item qRcmd,@var{command}
+@cindex execute remote command, remote request
+@cindex @samp{qRcmd} packet
+@var{command} (hex encoded) is passed to the local interpreter for
+execution. Invalid commands should be reported using the output
+string. Before the final result packet, the target may also respond
+with a number of intermediate @samp{O@var{output}} console output
+packets. @emph{Implementors should note that providing access to a
+stubs's interpreter may have security implications}.
-@var{thread-id} is the (big endian, hex encoded) thread id associated with the
-thread for which to fetch the TLS address.
+Reply:
+@table @samp
+@item OK
+A command response with no output.
+@item @var{OUTPUT}
+A command response with the hex encoded output string @var{OUTPUT}.
+@item E @var{NN}
+Indicate a badly formed request.
+@item
+An empty reply indicates that @samp{qRcmd} is not recognized.
+@end table
-@var{offset} is the (big endian, hex encoded) offset associated with the
-thread local variable. (This offset is obtained from the debug
-information associated with the variable.)
+@item qSymbol::
+@cindex symbol lookup, remote request
+@cindex @samp{qSymbol} packet
+Notify the target that @value{GDBN} is prepared to serve symbol lookup
+requests. Accept requests from the target for the values of symbols.
-@var{lm} is the (big endian, hex encoded) OS/ABI specific encoding of the
-the load module associated with the thread local storage. For example,
-a @sc{gnu}/Linux system will pass the link map address of the shared
-object associated with the thread local storage under consideration.
-Other operating environments may choose to represent the load module
-differently, so the precise meaning of this parameter will vary.
+Reply:
+@table @samp
+@item OK
+The target does not need to look up any (more) symbols.
+@item qSymbol:@var{sym_name}
+The target requests the value of symbol @var{sym_name} (hex encoded).
+@value{GDBN} may provide the value by using the
+@samp{qSymbol:@var{sym_value}:@var{sym_name}} message, described
+below.
+@end table
+
+@item qSymbol:@var{sym_value}:@var{sym_name}
+Set the value of @var{sym_name} to @var{sym_value}.
+
+@var{sym_name} (hex encoded) is the name of a symbol whose value the
+target has previously requested.
+
+@var{sym_value} (hex) is the value for symbol @var{sym_name}. If
+@value{GDBN} cannot supply a value for @var{sym_name}, then this field
+will be empty.
Reply:
-@table @asis
-@item @var{XX@dots{}}
-Hex encoded (big endian) bytes representing the address of the thread
-local storage requested.
+@table @samp
+@item OK
+The target does not need to look up any (more) symbols.
+@item qSymbol:@var{sym_name}
+The target requests the value of a new symbol @var{sym_name} (hex
+encoded). @value{GDBN} will continue to supply the values of symbols
+(if available), until the target ceases to request them.
+@end table
-@item @code{E}@var{nn} (where @var{nn} are hex digits)
-An error occurred.
+@item QTDP
+@itemx QTFrame
+@xref{Tracepoint Packets}.
-@item @code{""} (empty)
-An empty reply indicates that @code{qGetTLSAddr} is not supported by the stub.
+@item qThreadExtraInfo,@var{id}
+@cindex thread attributes info, remote request
+@cindex @samp{qThreadExtraInfo} packet
+Obtain a printable string description of a thread's attributes from
+the target OS. @var{id} is a thread-id in big-endian hex. This
+string may contain anything that the target OS thinks is interesting
+for @value{GDBN} to tell the user about the thread. The string is
+displayed in @value{GDBN}'s @code{info threads} display. Some
+examples of possible thread extra info strings are @samp{Runnable}, or
+@samp{Blocked on Mutex}.
+
+Reply:
+@table @samp
+@item @var{XX}@dots{}
+Where @samp{@var{XX}@dots{}} is a hex encoding of @sc{ascii} data,
+comprising the printable string containing the extra information about
+the thread's attributes.
@end table
-Use of this request packet is controlled by the @code{set remote
-get-thread-local-storage-address} command (@pxref{Remote
-configuration, set remote get-thread-local-storage-address}).
+@item QTStart
+@itemx QTStop
+@itemx QTinit
+@itemx QTro
+@itemx qTStatus
+@xref{Tracepoint Packets}.
@end table
@node Register Packet Format
@section Register Packet Format
-The following @samp{g}/@samp{G} packets have previously been defined.
+The following @code{g}/@code{G} packets have previously been defined.
In the below, some thirty-two bit registers are transferred as
sixty-four bits. Those registers should be zero/sign extended (which?)
to fill the space allocated. Register bytes are transfered in target
@end table
+@node Tracepoint Packets
+@section Tracepoint Packets
+@cindex tracepoint packets
+@cindex packets, tracepoint
+
+Here we describe the packets @value{GDBN} uses to implement
+tracepoints (@pxref{Tracepoints}).
+
+@table @samp
+
+@item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}@r{[}-@r{]}
+Create a new tracepoint, number @var{n}, at @var{addr}. If @var{ena}
+is @samp{E}, then the tracepoint is enabled; if it is @samp{D}, then
+the tracepoint is disabled. @var{step} is the tracepoint's step
+count, and @var{pass} is its pass count. If the trailing @samp{-} is
+present, further @samp{QTDP} packets will follow to specify this
+tracepoint's actions.
+
+Replies:
+@table @samp
+@item OK
+The packet was understood and carried out.
+@item
+The packet was not recognized.
+@end table
+
+@item QTDP:-@var{n}:@var{addr}:@r{[}S@r{]}@var{action}@dots{}@r{[}-@r{]}
+Define actions to be taken when a tracepoint is hit. @var{n} and
+@var{addr} must be the same as in the initial @samp{QTDP} packet for
+this tracepoint. This packet may only be sent immediately after
+another @samp{QTDP} packet that ended with a @samp{-}. If the
+trailing @samp{-} is present, further @samp{QTDP} packets will follow,
+specifying more actions for this tracepoint.
+
+In the series of action packets for a given tracepoint, at most one
+can have an @samp{S} before its first @var{action}. If such a packet
+is sent, it and the following packets define ``while-stepping''
+actions. Any prior packets define ordinary actions --- that is, those
+taken when the tracepoint is first hit. If no action packet has an
+@samp{S}, then all the packets in the series specify ordinary
+tracepoint actions.
+
+The @samp{@var{action}@dots{}} portion of the packet is a series of
+actions, concatenated without separators. Each action has one of the
+following forms:
+
+@table @samp
+
+@item R @var{mask}
+Collect the registers whose bits are set in @var{mask}. @var{mask} is
+a hexidecimal number whose @var{i}'th bit is set if register number
+@var{i} should be collected. (The least significant bit is numbered
+zero.) Note that @var{mask} may be any number of digits long; it may
+not fit in a 32-bit word.
+
+@item M @var{basereg},@var{offset},@var{len}
+Collect @var{len} bytes of memory starting at the address in register
+number @var{basereg}, plus @var{offset}. If @var{basereg} is
+@samp{-1}, then the range has a fixed address: @var{offset} is the
+address of the lowest byte to collect. The @var{basereg},
+@var{offset}, and @var{len} parameters are all unsigned hexidecimal
+values (the @samp{-1} value for @var{basereg} is a special case).
+
+@item X @var{len},@var{expr}
+Evaluate @var{expr}, whose length is @var{len}, and collect memory as
+it directs. @var{expr} is an agent expression, as described in
+@ref{Agent Expressions}. Each byte of the expression is encoded as a
+two-digit hex number in the packet; @var{len} is the number of bytes
+in the expression (and thus one-half the number of hex digits in the
+packet).
+
+@end table
+
+Any number of actions may be packed together in a single @samp{QTDP}
+packet, as long as the packet does not exceed the maximum packet
+length (400 bytes, for many stubs). There may be only one @samp{R}
+action per tracepoint, and it must precede any @samp{M} or @samp{X}
+actions. Any registers referred to by @samp{M} and @samp{X} actions
+must be collected by a preceding @samp{R} action. (The
+``while-stepping'' actions are treated as if they were attached to a
+separate tracepoint, as far as these restrictions are concerned.)
+
+Replies:
+@table @samp
+@item OK
+The packet was understood and carried out.
+@item
+The packet was not recognized.
+@end table
+
+@item QTFrame:@var{n}
+Select the @var{n}'th tracepoint frame from the buffer, and use the
+register and memory contents recorded there to answer subsequent
+request packets from @value{GDBN}.
+
+A successful reply from the stub indicates that the stub has found the
+requested frame. The response is a series of parts, concatenated
+without separators, describing the frame we selected. Each part has
+one of the following forms:
+
+@table @samp
+@item F @var{f}
+The selected frame is number @var{n} in the trace frame buffer;
+@var{f} is a hexidecimal number. If @var{f} is @samp{-1}, then there
+was no frame matching the criteria in the request packet.
+
+@item T @var{t}
+The selected trace frame records a hit of tracepoint number @var{t};
+@var{t} is a hexidecimal number.
+
+@end table
+
+@item QTFrame:pc:@var{addr}
+Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
+currently selected frame whose PC is @var{addr};
+@var{addr} is a hexidecimal number.
+
+@item QTFrame:tdp:@var{t}
+Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
+currently selected frame that is a hit of tracepoint @var{t}; @var{t}
+is a hexidecimal number.
+
+@item QTFrame:range:@var{start}:@var{end}
+Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
+currently selected frame whose PC is between @var{start} (inclusive)
+and @var{end} (exclusive); @var{start} and @var{end} are hexidecimal
+numbers.
+
+@item QTFrame:outside:@var{start}:@var{end}
+Like @samp{QTFrame:range:@var{start}:@var{end}}, but select the first
+frame @emph{outside} the given range of addresses.
+
+@item QTStart
+Begin the tracepoint experiment. Begin collecting data from tracepoint
+hits in the trace frame buffer.
+
+@item QTStop
+End the tracepoint experiment. Stop collecting trace frames.
+
+@item QTinit
+Clear the table of tracepoints, and empty the trace frame buffer.
+
+@item QTro:@var{start1},@var{end1}:@var{start2},@var{end2}:@dots{}
+Establish the given ranges of memory as ``transparent''. The stub
+will answer requests for these ranges from memory's current contents,
+if they were not collected as part of the tracepoint hit.
+
+@value{GDBN} uses this to mark read-only regions of memory, like those
+containing program code. Since these areas never change, they should
+still have the same contents they did when the tracepoint was hit, so
+there's no reason for the stub to refuse to provide their contents.
+
+@item qTStatus
+Ask the stub if there is a trace experiment running right now.
+
+Replies:
+@table @samp
+@item T0
+There is no trace experiment running.
+@item T1
+There is a trace experiment running.
+@end table
+
+@end table
+
+
+@node Interrupts
+@section Interrupts
+@cindex interrupts (remote protocol)
+
+When a program on the remote target is running, @value{GDBN} may
+attempt to interrupt it by sending a @samp{Ctrl-C} or a @code{BREAK},
+control of which is specified via @value{GDBN}'s @samp{remotebreak}
+setting (@pxref{set remotebreak}).
+
+The precise meaning of @code{BREAK} is defined by the transport
+mechanism and may, in fact, be undefined. @value{GDBN} does
+not currently define a @code{BREAK} mechanism for any of the network
+interfaces.
+
+@samp{Ctrl-C}, on the other hand, is defined and implemented for all
+transport mechanisms. It is represented by sending the single byte
+@code{0x03} without any of the usual packet overhead described in
+the Overview section (@pxref{Overview}). When a @code{0x03} byte is
+transmitted as part of a packet, it is considered to be packet data
+and does @emph{not} represent an interrupt. E.g., an @samp{X} packet
+(@pxref{X packet}, used for binary downloads, may include an unescaped
+@code{0x03} as part of its packet.
+
+Stubs are not required to recognize these interrupt mechanisms and the
+precise meaning associated with receipt of the interrupt is
+implementation defined. If the stub is successful at interrupting the
+running program, it is expected that it will send one of the Stop
+Reply Packets (@pxref{Stop Reply Packets}) to @value{GDBN} as a result
+of successfully stopping the program. Interrupts received while the
+program is stopped will be discarded.
+
@node Examples
@section Examples
projects / deliverable / binutils-gdb.git / blobdiff