\input texinfo @c -*-texinfo-*-
@c Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998,
-@c 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+@c 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
@c Free Software Foundation, Inc.
@c
@c %**start of header
@copying
Copyright @copyright{} 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
-1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
@end ifset
Version @value{GDBVN}.
-Copyright (C) 1988-2009 Free Software Foundation, Inc.
+Copyright (C) 1988-2010 Free Software Foundation, Inc.
This edition of the GDB manual is dedicated to the memory of Fred
Fish. Fred was a long-standing contributor to GDB and to Free
@value{GDBN}
* Operating System Information:: Getting additional information from
the operating system
+* Trace File Format:: GDB trace file format
* Copying:: GNU General Public License says
how you can copy and share GDB
* GNU Free Documentation License:: The license for this documentation
who have worked on the Xtensa port of @value{GDBN} in the past include
Steve Tjiang, John Newlin, and Scott Foehner.
+Michael Eager and staff of Xilinx, Inc., contributed support for the
+Xilinx MicroBlaze architecture.
+
@node Sample Session
@chapter A Sample @value{GDBN} Session
@itemx -x @var{file}
@cindex @code{--command}
@cindex @code{-x}
-Execute @value{GDBN} commands from file @var{file}. @xref{Command
-Files,, Command files}.
+Execute commands from file @var{file}. The contents of this file is
+evaluated exactly as the @code{source} command would.
+@xref{Command Files,, Command files}.
@item -eval-command @var{command}
@itemx -ex @var{command}
command files specified with @samp{-x} (and all commands from
initialization files, if not inhibited with @samp{-n}). Exit with
nonzero status if an error occurs in executing the @value{GDBN} commands
-in the command files.
+in the command files. Batch mode also disables pagination;
+@pxref{Screen Size} and acts as if @kbd{set confirm off} were in
+effect (@pxref{Messages/Warnings}).
Batch mode may be useful for running @value{GDBN} as a filter, for
example to download and run a program on another computer; in order to
* Attach:: Debugging an already-running process
* Kill Process:: Killing the child process
-* Inferiors:: Debugging multiple inferiors
+* Inferiors and Programs:: Debugging multiple inferiors and programs
* Threads:: Debugging programs with multiple threads
-* Processes:: Debugging programs with multiple processes
+* Forks:: Debugging forks
* Checkpoint/Restart:: Setting a @emph{bookmark} to return to later
@end menu
reads the symbol table again (while trying to preserve your current
breakpoint settings).
-@node Inferiors
-@section Debugging Multiple Inferiors
+@node Inferiors and Programs
+@section Debugging Multiple Inferiors and Programs
-Some @value{GDBN} targets are able to run multiple processes created
-from a single executable. This can happen, for instance, with an
-embedded system reporting back several processes via the remote
-protocol.
+@value{GDBN} lets you run and debug multiple programs in a single
+session. In addition, @value{GDBN} on some systems may let you run
+several programs simultaneously (otherwise you have to exit from one
+before starting another). In the most general case, you can have
+multiple threads of execution in each of multiple processes, launched
+from multiple executables.
@cindex inferior
@value{GDBN} represents the state of each program execution with an
object called an @dfn{inferior}. An inferior typically corresponds to
a process, but is more general and applies also to targets that do not
have processes. Inferiors may be created before a process runs, and
-may (in future) be retained after a process exits. Each run of an
-executable creates a new inferior, as does each attachment to an
-existing process. Inferiors have unique identifiers that are
-different from process ids, and may optionally be named as well.
-Usually each inferior will also have its own distinct address space,
-although some embedded targets may have several inferiors running in
-different parts of a single space.
+may be retained after a process exits. Inferiors have unique
+identifiers that are different from process ids. Usually each
+inferior will also have its own distinct address space, although some
+embedded targets may have several inferiors running in different parts
+of a single address space. Each inferior may in turn have multiple
+threads running in it.
-Each inferior may in turn have multiple threads running in it.
-
-To find out what inferiors exist at any moment, use @code{info inferiors}:
+To find out what inferiors exist at any moment, use @w{@code{info
+inferiors}}:
@table @code
@kindex info inferiors
@item
the target system's inferior identifier
+
+@item
+the name of the executable the inferior is running.
+
@end enumerate
@noindent
@smallexample
(@value{GDBP}) info inferiors
- Num Description
-* 1 process 2307
- 2 process 3401
+ Num Description Executable
+ 2 process 2307 hello
+* 1 process 3401 goodbye
@end smallexample
To switch focus between inferiors, use the @code{inferior} command:
in the first field of the @samp{info inferiors} display.
@end table
-To quit debugging one of the inferiors, you can either detach from it
-by using the @w{@code{detach inferior}} command (allowing it to run
-independently), or kill it using the @w{@code{kill inferior}} command:
+
+You can get multiple executables into a debugging session via the
+@code{add-inferior} and @w{@code{clone-inferior}} commands. On some
+systems @value{GDBN} can add inferiors to the debug session
+automatically by following calls to @code{fork} and @code{exec}. To
+remove inferiors from the debugging session use the
+@w{@code{remove-inferior}} command.
+
+@table @code
+@kindex add-inferior
+@item add-inferior [ -copies @var{n} ] [ -exec @var{executable} ]
+Adds @var{n} inferiors to be run using @var{executable} as the
+executable. @var{n} defaults to 1. If no executable is specified,
+the inferiors begins empty, with no program. You can still assign or
+change the program assigned to the inferior at any time by using the
+@code{file} command with the executable name as its argument.
+
+@kindex clone-inferior
+@item clone-inferior [ -copies @var{n} ] [ @var{infno} ]
+Adds @var{n} inferiors ready to execute the same program as inferior
+@var{infno}. @var{n} defaults to 1. @var{infno} defaults to the
+number of the current inferior. This is a convenient command when you
+want to run another instance of the inferior you are debugging.
+
+@smallexample
+(@value{GDBP}) info inferiors
+ Num Description Executable
+* 1 process 29964 helloworld
+(@value{GDBP}) clone-inferior
+Added inferior 2.
+1 inferiors added.
+(@value{GDBP}) info inferiors
+ Num Description Executable
+ 2 <null> helloworld
+* 1 process 29964 helloworld
+@end smallexample
+
+You can now simply switch focus to inferior 2 and run it.
+
+@kindex remove-inferior
+@item remove-inferior @var{infno}
+Removes the inferior @var{infno}. It is not possible to remove an
+inferior that is running with this command. For those, use the
+@code{kill} or @code{detach} command first.
+
+@end table
+
+To quit debugging one of the running inferiors that is not the current
+inferior, you can either detach from it by using the @w{@code{detach
+inferior}} command (allowing it to run independently), or kill it
+using the @w{@code{kill inferior}} command:
@table @code
@kindex detach inferior @var{infno}
@var{infno}, and remove it from the inferior list.
@end table
+After the successful completion of a command such as @code{detach},
+@code{detach inferior}, @code{kill} or @code{kill inferior}, or after
+a normal process exit, the inferior is still valid and listed with
+@code{info inferiors}, ready to be restarted.
+
+
To be notified when inferiors are started or exit under @value{GDBN}'s
control use @w{@code{set print inferior-events}}:
inferiors have started, exited or have been detached.
@end table
+Many commands will work the same with multiple programs as with a
+single program: e.g., @code{print myglobal} will simply display the
+value of @code{myglobal} in the current inferior.
+
+
+Occasionaly, when debugging @value{GDBN} itself, it may be useful to
+get more info about the relationship of inferiors, programs, address
+spaces in a debug session. You can do that with the @w{@code{maint
+info program-spaces}} command.
+
+@table @code
+@kindex maint info program-spaces
+@item maint info program-spaces
+Print a list of all program spaces currently being managed by
+@value{GDBN}.
+
+@value{GDBN} displays for each program space (in this order):
+
+@enumerate
+@item
+the program space number assigned by @value{GDBN}
+
+@item
+the name of the executable loaded into the program space, with e.g.,
+the @code{file} command.
+
+@end enumerate
+
+@noindent
+An asterisk @samp{*} preceding the @value{GDBN} program space number
+indicates the current program space.
+
+In addition, below each program space line, @value{GDBN} prints extra
+information that isn't suitable to display in tabular form. For
+example, the list of inferiors bound to the program space.
+
+@smallexample
+(@value{GDBP}) maint info program-spaces
+ Id Executable
+ 2 goodbye
+ Bound inferiors: ID 1 (process 21561)
+* 1 hello
+@end smallexample
+
+Here we can see that no inferior is running the program @code{hello},
+while @code{process 21561} is running the program @code{goodbye}. On
+some targets, it is possible that multiple inferiors are bound to the
+same program space. The most common example is that of debugging both
+the parent and child processes of a @code{vfork} call. For example,
+
+@smallexample
+(@value{GDBP}) maint info program-spaces
+ Id Executable
+* 1 vfork-test
+ Bound inferiors: ID 2 (process 18050), ID 1 (process 18045)
+@end smallexample
+
+Here, both inferior 2 and inferior 1 are running in the same program
+space as a result of inferior 1 having executed a @code{vfork} call.
+@end table
+
@node Threads
@section Debugging Programs with Multiple Threads
Display current libthread_db search path.
@end table
-@node Processes
-@section Debugging Programs with Multiple Processes
+@node Forks
+@section Debugging Forks
@cindex fork, debugging programs which call
@cindex multiple processes
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 inferiors}} command, and switch from one fork
-to another by using the @code{inferior} command (@pxref{Inferiors,
-,Debugging Multiple Inferiors}).
+to another by using the @code{inferior} command (@pxref{Inferiors and
+Programs, ,Debugging Multiple Inferiors and Programs}).
To quit debugging one of the forked processes, you can either detach
from it by using the @w{@code{detach inferior}} command (allowing it
to run independently), or kill it using the @w{@code{kill inferior}}
-command. @xref{Inferiors, ,Debugging Multiple Inferiors}.
+command. @xref{Inferiors and Programs, ,Debugging Multiple Inferiors
+and Programs}.
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
cannot debug the child or parent until an @code{exec} call completes.
If you issue a @code{run} command to @value{GDBN} after an @code{exec}
-call executes, the new target restarts. To restart the parent process,
-use the @code{file} command with the parent executable name as its
-argument.
+call executes, the new target restarts. To restart the parent
+process, use the @code{file} command with the parent executable name
+as its argument. By default, after an @code{exec} call executes,
+@value{GDBN} discards the symbols of the previous executable image.
+You can change this behaviour with the @w{@code{set follow-exec-mode}}
+command.
+
+@table @code
+@kindex set follow-exec-mode
+@item set follow-exec-mode @var{mode}
+
+Set debugger response to a program call of @code{exec}. An
+@code{exec} call replaces the program image of a process.
+
+@code{follow-exec-mode} can be:
+
+@table @code
+@item new
+@value{GDBN} creates a new inferior and rebinds the process to this
+new inferior. The program the process was running before the
+@code{exec} call can be restarted afterwards by restarting the
+original inferior.
+
+For example:
+
+@smallexample
+(@value{GDBP}) info inferiors
+(gdb) info inferior
+ Id Description Executable
+* 1 <null> prog1
+(@value{GDBP}) run
+process 12020 is executing new program: prog2
+Program exited normally.
+(@value{GDBP}) info inferiors
+ Id Description Executable
+* 2 <null> prog2
+ 1 <null> prog1
+@end smallexample
+
+@item same
+@value{GDBN} keeps the process bound to the same inferior. The new
+executable image replaces the previous executable loaded in the
+inferior. Restarting the inferior after the @code{exec} call, with
+e.g., the @code{run} command, restarts the executable the process was
+running after the @code{exec} call. This is the default mode.
+
+For example:
+
+@smallexample
+(@value{GDBP}) info inferiors
+ Id Description Executable
+* 1 <null> prog1
+(@value{GDBP}) run
+process 12020 is executing new program: prog2
+Program exited normally.
+(@value{GDBP}) info inferiors
+ Id Description Executable
+* 1 <null> prog2
+@end smallexample
+
+@end table
+@end table
You can use the @code{catch} command to make @value{GDBN} stop whenever
a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set
A call to @code{exec}. This is currently only available for HP-UX
and @sc{gnu}/Linux.
+@item syscall
+@itemx syscall @r{[}@var{name} @r{|} @var{number}@r{]} @r{...}
+@cindex break on a system call.
+A call to or return from a system call, a.k.a.@: @dfn{syscall}. A
+syscall is a mechanism for application programs to request a service
+from the operating system (OS) or one of the OS system services.
+@value{GDBN} can catch some or all of the syscalls issued by the
+debuggee, and show the related information for each syscall. If no
+argument is specified, calls to and returns from all system calls
+will be caught.
+
+@var{name} can be any system call name that is valid for the
+underlying OS. Just what syscalls are valid depends on the OS. On
+GNU and Unix systems, you can find the full list of valid syscall
+names on @file{/usr/include/asm/unistd.h}.
+
+@c For MS-Windows, the syscall names and the corresponding numbers
+@c can be found, e.g., on this URL:
+@c http://www.metasploit.com/users/opcode/syscalls.html
+@c but we don't support Windows syscalls yet.
+
+Normally, @value{GDBN} knows in advance which syscalls are valid for
+each OS, so you can use the @value{GDBN} command-line completion
+facilities (@pxref{Completion,, command completion}) to list the
+available choices.
+
+You may also specify the system call numerically. A syscall's
+number is the value passed to the OS's syscall dispatcher to
+identify the requested service. When you specify the syscall by its
+name, @value{GDBN} uses its database of syscalls to convert the name
+into the corresponding numeric code, but using the number directly
+may be useful if @value{GDBN}'s database does not have the complete
+list of syscalls on your system (e.g., because @value{GDBN} lags
+behind the OS upgrades).
+
+The example below illustrates how this command works if you don't provide
+arguments to it:
+
+@smallexample
+(@value{GDBP}) catch syscall
+Catchpoint 1 (syscall)
+(@value{GDBP}) r
+Starting program: /tmp/catch-syscall
+
+Catchpoint 1 (call to syscall 'close'), \
+ 0xffffe424 in __kernel_vsyscall ()
+(@value{GDBP}) c
+Continuing.
+
+Catchpoint 1 (returned from syscall 'close'), \
+ 0xffffe424 in __kernel_vsyscall ()
+(@value{GDBP})
+@end smallexample
+
+Here is an example of catching a system call by name:
+
+@smallexample
+(@value{GDBP}) catch syscall chroot
+Catchpoint 1 (syscall 'chroot' [61])
+(@value{GDBP}) r
+Starting program: /tmp/catch-syscall
+
+Catchpoint 1 (call to syscall 'chroot'), \
+ 0xffffe424 in __kernel_vsyscall ()
+(@value{GDBP}) c
+Continuing.
+
+Catchpoint 1 (returned from syscall 'chroot'), \
+ 0xffffe424 in __kernel_vsyscall ()
+(@value{GDBP})
+@end smallexample
+
+An example of specifying a system call numerically. In the case
+below, the syscall number has a corresponding entry in the XML
+file, so @value{GDBN} finds its name and prints it:
+
+@smallexample
+(@value{GDBP}) catch syscall 252
+Catchpoint 1 (syscall(s) 'exit_group')
+(@value{GDBP}) r
+Starting program: /tmp/catch-syscall
+
+Catchpoint 1 (call to syscall 'exit_group'), \
+ 0xffffe424 in __kernel_vsyscall ()
+(@value{GDBP}) c
+Continuing.
+
+Program exited normally.
+(@value{GDBP})
+@end smallexample
+
+However, there can be situations when there is no corresponding name
+in XML file for that syscall number. In this case, @value{GDBN} prints
+a warning message saying that it was not able to find the syscall name,
+but the catchpoint will be set anyway. See the example below:
+
+@smallexample
+(@value{GDBP}) catch syscall 764
+warning: The number '764' does not represent a known syscall.
+Catchpoint 2 (syscall 764)
+(@value{GDBP})
+@end smallexample
+
+If you configure @value{GDBN} using the @samp{--without-expat} option,
+it will not be able to display syscall names. Also, if your
+architecture does not have an XML file describing its system calls,
+you will not be able to see the syscall names. It is important to
+notice that these two features are used for accessing the syscall
+name database. In either case, you will see a warning like this:
+
+@smallexample
+(@value{GDBP}) catch syscall
+warning: Could not open "syscalls/i386-linux.xml"
+warning: Could not load the syscall XML file 'syscalls/i386-linux.xml'.
+GDB will not be able to display syscall names.
+Catchpoint 1 (syscall)
+(@value{GDBP})
+@end smallexample
+
+Of course, the file name will change depending on your architecture and system.
+
+Still using the example above, you can also try to catch a syscall by its
+number. In this case, you would see something like:
+
+@smallexample
+(@value{GDBP}) catch syscall 252
+Catchpoint 1 (syscall(s) 252)
+@end smallexample
+
+Again, in this case @value{GDBN} would not be able to display syscall's names.
+
@item fork
A call to @code{fork}. This is currently only available for HP-UX
and @sc{gnu}/Linux.
program.
You can use the @code{thread} qualifier on conditional breakpoints as
-well; in this case, place @samp{thread @var{threadno}} before the
-breakpoint condition, like this:
+well; in this case, place @samp{thread @var{threadno}} before or
+after the breakpoint condition, like this:
@smallexample
(@value{GDBP}) break frik.c:13 thread 28 if bartab > lim
to the caller of that function, @emph{before} the function was called,
just as the normal @code{next} command would take you from the last
line of a function back to its return to its caller
-@footnote{Unles the code is too heavily optimized.}.
+@footnote{Unless the code is too heavily optimized.}.
@kindex reverse-nexti
@kindex rni @r{(@code{reverse-nexti})}
Like @code{nexti}, @code{reverse-nexti} executes a single instruction
in reverse, except that called functions are ``un-executed'' atomically.
That is, if the previously executed instruction was a return from
-another instruction, @code{reverse-nexti} will continue to execute
+another function, @code{reverse-nexti} will continue to execute
in reverse until the call to that function (from the current stack
frame) is reached.
@item show record stop-at-limit
Show the current setting of @code{stop-at-limit}.
-@kindex info record insn-number
-@item info record insn-number
-Show the current number of recorded instructions.
+@kindex info record
+@item info record
+Show various statistics about the state of process record and its
+in-memory execution log buffer, including:
+
+@itemize @bullet
+@item
+Whether in record mode or replay mode.
+@item
+Lowest recorded instruction number (counting from when the current execution log started recording instructions).
+@item
+Highest recorded instruction number.
+@item
+Current instruction about to be replayed (if in replay mode).
+@item
+Number of instructions contained in the execution log.
+@item
+Maximum number of instructions that may be contained in the execution log.
+@end itemize
@kindex record delete
@kindex rec del
The default memory range is the function surrounding the
program counter of the selected frame. A single argument to this
command is a program counter value; @value{GDBN} dumps the function
-surrounding this value. Two arguments specify a range of addresses
-(first inclusive, second exclusive) to dump.
+surrounding this value. When two arguments are given, they should
+be separated by a comma, possibly surrounded by whitespace. The
+arguments specify a range of addresses (first inclusive, second exclusive)
+to dump. In that case, the name of the function is also printed (since
+there could be several functions in the given range).
+
+The argument(s) can be any expression yielding a numeric value, such as
+@samp{0x32c4}, @samp{&main+10} or @samp{$pc - 8}.
+
+If the range of memory being disassembled contains current program counter,
+the instruction at that location is shown with a @code{=>} marker.
@end table
The following example shows the disassembly of a range of addresses of
HP PA-RISC 2.0 code:
@smallexample
-(@value{GDBP}) disas 0x32c4 0x32e4
+(@value{GDBP}) disas 0x32c4, 0x32e4
Dump of assembler code from 0x32c4 to 0x32e4:
-0x32c4 <main+204>: addil 0,dp
-0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26
-0x32cc <main+212>: ldil 0x3000,r31
-0x32d0 <main+216>: ble 0x3f8(sr4,r31)
-0x32d4 <main+220>: ldo 0(r31),rp
-0x32d8 <main+224>: addil -0x800,dp
-0x32dc <main+228>: ldo 0x588(r1),r26
-0x32e0 <main+232>: ldil 0x3000,r31
+ 0x32c4 <main+204>: addil 0,dp
+ 0x32c8 <main+208>: ldw 0x22c(sr0,r1),r26
+ 0x32cc <main+212>: ldil 0x3000,r31
+ 0x32d0 <main+216>: ble 0x3f8(sr4,r31)
+ 0x32d4 <main+220>: ldo 0(r31),rp
+ 0x32d8 <main+224>: addil -0x800,dp
+ 0x32dc <main+228>: ldo 0x588(r1),r26
+ 0x32e0 <main+232>: ldil 0x3000,r31
End of assembler dump.
@end smallexample
-Here is an example showing mixed source+assembly for Intel x86:
+Here is an example showing mixed source+assembly for Intel x86, when the
+program is stopped just after function prologue:
@smallexample
(@value{GDBP}) disas /m main
Dump of assembler code for function main:
5 @{
-0x08048330 <main+0>: push %ebp
-0x08048331 <main+1>: mov %esp,%ebp
-0x08048333 <main+3>: sub $0x8,%esp
-0x08048336 <main+6>: and $0xfffffff0,%esp
-0x08048339 <main+9>: sub $0x10,%esp
+ 0x08048330 <+0>: push %ebp
+ 0x08048331 <+1>: mov %esp,%ebp
+ 0x08048333 <+3>: sub $0x8,%esp
+ 0x08048336 <+6>: and $0xfffffff0,%esp
+ 0x08048339 <+9>: sub $0x10,%esp
6 printf ("Hello.\n");
-0x0804833c <main+12>: movl $0x8048440,(%esp)
-
0x08048343 <main+19>: call 0x8048284 <puts@@plt>
+=> 0x0804833c <+12>: movl $0x8048440,(%esp)
+
0x08048343 <+19>: call 0x8048284 <puts@@plt>
7 return 0;
8 @}
-0x08048348 <main+24>: mov $0x0,%eax
-0x0804834d <main+29>: leave
-0x0804834e <main+30>: ret
+ 0x08048348 <+24>: mov $0x0,%eax
+ 0x0804834d <+29>: leave
+ 0x0804834e <+30>: ret
End of assembler dump.
@end smallexample
command (abbreviated @code{p}), or its synonym @code{inspect}. It
evaluates and prints the value of an expression of the language your
program is written in (@pxref{Languages, ,Using @value{GDBN} with
-Different Languages}).
+Different Languages}). It may also print the expression using a
+Python-based pretty-printer (@pxref{Pretty Printing}).
@table @code
@item print @var{expr}
@item r
@cindex raw printing
Print using the @samp{raw} formatting. By default, @value{GDBN} will
-use a type-specific pretty-printer. The @samp{r} format bypasses any
-pretty-printer which might exist for the value's type.
+use a Python-based pretty-printer, if one is available (@pxref{Pretty
+Printing}). This typically results in a higher-level display of the
+value's contents. The @samp{r} format bypasses any Python
+pretty-printer which might exist.
@end table
For example, to print the program counter in hex (@pxref{Registers}), type
the repeat count @var{n} is used again; the other arguments default as
for successive uses of @code{x}.
+When examining machine instructions, the instruction at current program
+counter is shown with a @code{=>} marker. For example:
+
+@smallexample
+(@value{GDBP}) x/5i $pc-6
+ 0x804837f <main+11>: mov %esp,%ebp
+ 0x8048381 <main+13>: push %ecx
+ 0x8048382 <main+14>: sub $0x4,%esp
+=> 0x8048385 <main+17>: movl $0x8048460,(%esp)
+ 0x804838c <main+24>: call 0x80482d4 <puts@@plt>
+@end smallexample
+
@cindex @code{$_}, @code{$__}, and value history
The addresses and contents printed by the @code{x} command are not saved
in the value history because there is often too much of them and they
@item $_siginfo
@vindex $_siginfo@r{, convenience variable}
-The variable @code{$_siginfo} is bound to extra signal information
-inspection (@pxref{extra signal information}).
+The variable @code{$_siginfo} contains extra signal information
+(@pxref{extra signal information}). Note that @code{$_siginfo}
+could be empty, if the application has not yet received any signals.
+For example, it will be empty before you execute the @code{run} command.
@end table
On HP-UX systems, if you refer to a function or variable name that
packets used to implement tracepoints are described in @ref{Tracepoint
Packets}.
+It is also possible to get trace data from a file, in a manner reminiscent
+of corefiles; you specify the filename, and use @code{tfind} to search
+through the file. @xref{Trace Files}, for more details.
+
This chapter describes the tracepoint commands and features.
@menu
* Set Tracepoints::
* Analyze Collected Data::
* Tracepoint Variables::
+* Trace Files::
@end menu
@node Set Tracepoints
tracepoints cannot run @value{GDBN} commands when they are
hit. Tracepoints may not be thread-specific either.
+@cindex fast tracepoints
+Some targets may support @dfn{fast tracepoints}, which are inserted in
+a different way (such as with a jump instead of a trap), that is
+faster but possibly restricted in where they may be installed.
+
This section describes commands to set tracepoints and associated
conditions and actions.
* Enable and Disable Tracepoints::
* Tracepoint Passcounts::
* Tracepoint Conditions::
+* Trace State Variables::
* Tracepoint Actions::
* Listing Tracepoints::
* Starting and Stopping Trace Experiments::
+* Tracepoint Restrictions::
@end menu
@node Create and Delete Tracepoints
@xref{Tracepoint Conditions, ,Tracepoint Conditions}, for more
information on tracepoint conditions.
+@item ftrace @var{location} [ if @var{cond} ]
+@cindex set fast tracepoint
+@kindex ftrace
+The @code{ftrace} command sets a fast tracepoint. For targets that
+support them, fast tracepoints will use a more efficient but possibly
+less general technique to trigger data collection, such as a jump
+instruction instead of a trap, or some sort of hardware support. It
+may not be possible to create a fast tracepoint at the desired
+location, in which case the command will exit with an explanatory
+message.
+
+@value{GDBN} handles arguments to @code{ftrace} exactly as for
+@code{trace}.
+
@vindex $tpnum
@cindex last tracepoint number
@cindex recent tracepoint number
(@value{GDBP}) @kbd{trace normal_operation if errcode > 0}
@end smallexample
+@node Trace State Variables
+@subsection Trace State Variables
+@cindex trace state variables
+
+A @dfn{trace state variable} is a special type of variable that is
+created and managed by target-side code. The syntax is the same as
+that for GDB's convenience variables (a string prefixed with ``$''),
+but they are stored on the target. They must be created explicitly,
+using a @code{tvariable} command. They are always 64-bit signed
+integers.
+
+Trace state variables are remembered by @value{GDBN}, and downloaded
+to the target along with tracepoint information when the trace
+experiment starts. There are no intrinsic limits on the number of
+trace state variables, beyond memory limitations of the target.
+
+@cindex convenience variables, and trace state variables
+Although trace state variables are managed by the target, you can use
+them in print commands and expressions as if they were convenience
+variables; @value{GDBN} will get the current value from the target
+while the trace experiment is running. Trace state variables share
+the same namespace as other ``$'' variables, which means that you
+cannot have trace state variables with names like @code{$23} or
+@code{$pc}, nor can you have a trace state variable and a convenience
+variable with the same name.
+
+@table @code
+
+@item tvariable $@var{name} [ = @var{expression} ]
+@kindex tvariable
+The @code{tvariable} command creates a new trace state variable named
+@code{$@var{name}}, and optionally gives it an initial value of
+@var{expression}. @var{expression} is evaluated when this command is
+entered; the result will be converted to an integer if possible,
+otherwise @value{GDBN} will report an error. A subsequent
+@code{tvariable} command specifying the same name does not create a
+variable, but instead assigns the supplied initial value to the
+existing variable of that name, overwriting any previous initial
+value. The default initial value is 0.
+
+@item info tvariables
+@kindex info tvariables
+List all the trace state variables along with their initial values.
+Their current values may also be displayed, if the trace experiment is
+currently running.
+
+@item delete tvariable @r{[} $@var{name} @dots{} @r{]}
+@kindex delete tvariable
+Delete the given trace state variables, or all of them if no arguments
+are specified.
+
+@end table
+
@node Tracepoint Actions
@subsection Tracepoint Action Lists
The command @code{info scope} (@pxref{Symbols, info scope}) is
particularly useful for figuring out what data to collect.
+@kindex teval @r{(tracepoints)}
+@item teval @var{expr1}, @var{expr2}, @dots{}
+Evaluate the given expressions when the tracepoint is hit. This
+command accepts a comma-separated list of expressions. The results
+are discarded, so this is mainly useful for assigning values to trace
+state variables (@pxref{Trace State Variables}) without adding those
+values to the trace buffer, as would be the case if the @code{collect}
+action were used.
+
@kindex while-stepping @r{(tracepoints)}
@item while-stepping @var{n}
-Perform @var{n} single-step traces after the tracepoint, collecting
-new data at each step. The @code{while-stepping} command is
-followed by the list of what to collect while stepping (followed by
-its own @code{end} command):
+Perform @var{n} single-step instruction traces after the tracepoint,
+collecting new data at each instruction. The @code{while-stepping}
+command is followed by the list of what to collect while stepping
+(followed by its own @code{end} command):
@smallexample
> while-stepping 12
@noindent
You may abbreviate @code{while-stepping} as @code{ws} or
@code{stepping}.
+
+@item set default-collect @var{expr1}, @var{expr2}, @dots{}
+@kindex set default-collect
+@cindex default collection action
+This variable is a list of expressions to collect at each tracepoint
+hit. It is effectively an additional @code{collect} action prepended
+to every tracepoint action list. The expressions are parsed
+individually for each tracepoint, so for instance a variable named
+@code{xyz} may be interpreted as a global for one tracepoint, and a
+local for another, as appropriate to the tracepoint's location.
+
+@item show default-collect
+@kindex show default-collect
+Show the list of expressions that are collected by default at each
+tracepoint hit.
+
@end table
@node Listing Tracepoints
(@value{GDBP}) @b{tstop}
@end smallexample
+@cindex disconnected tracing
+You can choose to continue running the trace experiment even if
+@value{GDBN} disconnects from the target, voluntarily or
+involuntarily. For commands such as @code{detach}, the debugger will
+ask what you want to do with the trace. But for unexpected
+terminations (@value{GDBN} crash, network outage), it would be
+unfortunate to lose hard-won trace data, so the variable
+@code{disconnected-tracing} lets you decide whether the trace should
+continue running without @value{GDBN}.
+
+@table @code
+@item set disconnected-tracing on
+@itemx set disconnected-tracing off
+@kindex set disconnected-tracing
+Choose whether a tracing run should continue to run if @value{GDBN}
+has disconnected from the target. Note that @code{detach} or
+@code{quit} will ask you directly what to do about a running trace no
+matter what this variable's setting, so the variable is mainly useful
+for handling unexpected situations, such as loss of the network.
+
+@item show disconnected-tracing
+@kindex show disconnected-tracing
+Show the current choice for disconnected tracing.
+
+@end table
+
+When you reconnect to the target, the trace experiment may or may not
+still be running; it might have filled the trace buffer in the
+meantime, or stopped for one of the other reasons. If it is running,
+it will continue after reconnection.
+
+Upon reconnection, the target will upload information about the
+tracepoints in effect. @value{GDBN} will then compare that
+information to the set of tracepoints currently defined, and attempt
+to match them up, allowing for the possibility that the numbers may
+have changed due to creation and deletion in the meantime. If one of
+the target's tracepoints does not match any in @value{GDBN}, the
+debugger will create a new tracepoint, so that you have a number with
+which to specify that tracepoint. This matching-up process is
+necessarily heuristic, and it may result in useless tracepoints being
+created; you may simply delete them if they are of no use.
+
+@cindex circular trace buffer
+If your target agent supports a @dfn{circular trace buffer}, then you
+can run a trace experiment indefinitely without filling the trace
+buffer; when space runs out, the agent deletes already-collected trace
+frames, oldest first, until there is enough room to continue
+collecting. This is especially useful if your tracepoints are being
+hit too often, and your trace gets terminated prematurely because the
+buffer is full. To ask for a circular trace buffer, simply set
+@samp{circular_trace_buffer} to on. You can set this at any time,
+including during tracing; if the agent can do it, it will change
+buffer handling on the fly, otherwise it will not take effect until
+the next run.
+
+@table @code
+@item set circular-trace-buffer on
+@itemx set circular-trace-buffer off
+@kindex set circular-trace-buffer
+Choose whether a tracing run should use a linear or circular buffer
+for trace data. A linear buffer will not lose any trace data, but may
+fill up prematurely, while a circular buffer will discard old trace
+data, but it will have always room for the latest tracepoint hits.
+
+@item show circular-trace-buffer
+@kindex show circular-trace-buffer
+Show the current choice for the trace buffer. Note that this may not
+match the agent's current buffer handling, nor is it guaranteed to
+match the setting that might have been in effect during a past run,
+for instance if you are looking at frames from a trace file.
+
+@end table
+
+@node Tracepoint Restrictions
+@subsection Tracepoint Restrictions
+
+@cindex tracepoint restrictions
+There are a number of restrictions on the use of tracepoints. As
+described above, tracepoint data gathering occurs on the target
+without interaction from @value{GDBN}. Thus the full capabilities of
+the debugger are not available during data gathering, and then at data
+examination time, you will be limited by only having what was
+collected. The following items describe some common problems, but it
+is not exhaustive, and you may run into additional difficulties not
+mentioned here.
+
+@itemize @bullet
+
+@item
+Tracepoint expressions are intended to gather objects (lvalues). Thus
+the full flexibility of GDB's expression evaluator is not available.
+You cannot call functions, cast objects to aggregate types, access
+convenience variables or modify values (except by assignment to trace
+state variables). Some language features may implicitly call
+functions (for instance Objective-C fields with accessors), and therefore
+cannot be collected either.
+
+@item
+Collection of local variables, either individually or in bulk with
+@code{$locals} or @code{$args}, during @code{while-stepping} may
+behave erratically. The stepping action may enter a new scope (for
+instance by stepping into a function), or the location of the variable
+may change (for instance it is loaded into a register). The
+tracepoint data recorded uses the location information for the
+variables that is correct for the tracepoint location. When the
+tracepoint is created, it is not possible, in general, to determine
+where the steps of a @code{while-stepping} sequence will advance the
+program---particularly if a conditional branch is stepped.
+
+@item
+Collection of an incompletely-initialized or partially-destroyed object
+may result in something that @value{GDBN} cannot display, or displays
+in a misleading way.
+
+@item
+When @value{GDBN} displays a pointer to character it automatically
+dereferences the pointer to also display characters of the string
+being pointed to. However, collecting the pointer during tracing does
+not automatically collect the string. You need to explicitly
+dereference the pointer and provide size information if you want to
+collect not only the pointer, but the memory pointed to. For example,
+@code{*ptr@@50} can be used to collect the 50 element array pointed to
+by @code{ptr}.
+
+@item
+It is not possible to collect a complete stack backtrace at a
+tracepoint. Instead, you may collect the registers and a few hundred
+bytes from the stack pointer with something like @code{*$esp@@300}
+(adjust to use the name of the actual stack pointer register on your
+target architecture, and the amount of stack you wish to capture).
+Then the @code{backtrace} command will show a partial backtrace when
+using a trace frame. The number of stack frames that can be examined
+depends on the sizes of the frames in the collected stack. Note that
+if you ask for a block so large that it goes past the bottom of the
+stack, the target agent may report an error trying to read from an
+invalid address.
+
+@end itemize
@node Analyze Collected Data
@section Using the Collected Data
@item tfind outside @var{addr1}, @var{addr2}
Find the next snapshot whose PC is outside the given range of
-addresses.
+addresses (exclusive).
@item tfind range @var{addr1}, @var{addr2}
Find the next snapshot whose PC is between @var{addr1} and
-@var{addr2}. @c FIXME: Is the range inclusive or exclusive?
+@var{addr2} (inclusive).
@item tfind line @r{[}@var{file}:@r{]}@var{n}
Find the next snapshot associated with the source line @var{n}. If
Here's a simple example of using these convenience variables for
stepping through all the trace snapshots and printing some of their
-data.
+data. Note that these are not the same as trace state variables,
+which are managed by the target.
@smallexample
(@value{GDBP}) @b{tfind start}
> end
@end smallexample
+@node Trace Files
+@section Using Trace Files
+@cindex trace files
+
+In some situations, the target running a trace experiment may no
+longer be available; perhaps it crashed, or the hardware was needed
+for a different activity. To handle these cases, you can arrange to
+dump the trace data into a file, and later use that file as a source
+of trace data, via the @code{target tfile} command.
+
+@table @code
+
+@kindex tsave
+@item tsave [ -r ] @var{filename}
+Save the trace data to @var{filename}. By default, this command
+assumes that @var{filename} refers to the host filesystem, so if
+necessary @value{GDBN} will copy raw trace data up from the target and
+then save it. If the target supports it, you can also supply the
+optional argument @code{-r} (``remote'') to direct the target to save
+the data directly into @var{filename} in its own filesystem, which may be
+more efficient if the trace buffer is very large. (Note, however, that
+@code{target tfile} can only read from files accessible to the host.)
+
+@kindex target tfile
+@kindex tfile
+@item target tfile @var{filename}
+Use the file named @var{filename} as a source of trace data. Commands
+that examine data work as they do with a live target, but it is not
+possible to run any new trace experiments. @code{tstatus} will report
+the state of the trace run at the moment the data was saved, as well
+as the current trace frame you are examining. @var{filename} must be
+on a filesystem accessible to the host.
+
+@end table
+
@node Overlays
@chapter Debugging Programs That Use Overlays
@cindex overlays
@code{Standard} explicitly.
@end itemize
+Older versions of the compiler sometimes generate erroneous debugging
+information, resulting in the debugger incorrectly printing the value
+of affected entities. In some cases, the debugger is able to work
+around an issue automatically. In other cases, the debugger is able
+to work around the issue, but the work-around has to be specifically
+enabled.
+
+@kindex set ada trust-PAD-over-XVS
+@kindex show ada trust-PAD-over-XVS
+@table @code
+
+@item set ada trust-PAD-over-XVS on
+Configure GDB to strictly follow the GNAT encoding when computing the
+value of Ada entities, particularly when @code{PAD} and @code{PAD___XVS}
+types are involved (see @code{ada/exp_dbug.ads} in the GCC sources for
+a complete description of the encoding used by the GNAT compiler).
+This is the default.
+
+@item set ada trust-PAD-over-XVS off
+This is related to the encoding using by the GNAT compiler. If @value{GDBN}
+sometimes prints the wrong value for certain entities, changing @code{ada
+trust-PAD-over-XVS} to @code{off} activates a work-around which may fix
+the issue. It is always safe to set @code{ada trust-PAD-over-XVS} to
+@code{off}, but this incurs a slight performance penalty, so it is
+recommended to leave this setting to @code{on} unless necessary.
+
+@end table
+
@node Unsupported Languages
@section Unsupported Languages
@kindex info variables
@item info variables
-Print the names and data types of all variables that are declared
+Print the names and data types of all variables that are defined
outside of functions (i.e.@: excluding local variables).
@item info variables @var{regexp}
@kindex readnow
@cindex reading symbols immediately
@cindex symbols, reading immediately
-@item symbol-file @var{filename} @r{[} -readnow @r{]}
-@itemx file @var{filename} @r{[} -readnow @r{]}
+@item symbol-file @r{[} -readnow @r{]} @var{filename}
+@itemx file @r{[} -readnow @r{]} @var{filename}
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
@table @code
@kindex set debug-file-directory
-@item set debug-file-directory @var{directory}
-Set the directory which @value{GDBN} searches for separate debugging
-information files to @var{directory}.
+@item set debug-file-directory @var{directories}
+Set the directories which @value{GDBN} searches for separate debugging
+information files to @var{directory}. Multiple directory components can be set
+concatenating them by a directory separator.
@kindex show debug-file-directory
@item show debug-file-directory
-Show the directory @value{GDBN} searches for separate debugging
+Show the directories @value{GDBN} searches for separate debugging
information files.
@end table
Disable or enable specific debugging messages associated with the remote
protocol (@pxref{Remote Protocol}).
+@item monitor set libthread-db-search-path [PATH]
+@cindex gdbserver, search path for @code{libthread_db}
+When this command is issued, @var{path} is a colon-separated list of
+directories to search for @code{libthread_db} (@pxref{Threads,,set
+libthread-db-search-path}). If you omit @var{path},
+@samp{libthread-db-search-path} will be reset to an empty list.
+
@item monitor exit
Tell gdbserver to exit immediately. This command should be followed by
@code{disconnect} to close the debugging session. @code{gdbserver} will
target system. If it is not set, the target will use a default
filename (e.g.@: the last program run).
+@item set remote interrupt-sequence
+@cindex interrupt remote programs
+@cindex select Ctrl-C, BREAK or BREAK-g
+Allow the user to select one of @samp{Ctrl-C}, a @code{BREAK} or
+@samp{BREAK-g} as the
+sequence to the remote target in order to interrupt the execution.
+@samp{Ctrl-C} is a default. Some system prefers @code{BREAK} which
+is high level of serial line for some certain time.
+Linux kernel prefers @samp{BREAK-g}, a.k.a Magic SysRq g.
+It is @code{BREAK} signal followed by character @code{g}.
+
+@item show interrupt-sequence
+Show which of @samp{Ctrl-C}, @code{BREAK} or @code{BREAK-g}
+is sent by @value{GDBN} to interrupt the remote program.
+@code{BREAK-g} is BREAK signal followed by @code{g} and
+also known as Magic SysRq g.
+
+@item set remote interrupt-on-connect
+@cindex send interrupt-sequence on start
+Specify whether interrupt-sequence is sent to remote target when
+@value{GDBN} connects to it. This is mostly needed when you debug
+Linux kernel. Linux kernel expects @code{BREAK} followed by @code{g}
+which is known as Magic SysRq g in order to connect @value{GDBN}.
+
+@item show interrupt-on-connect
+Show whether interrupt-sequence is sent
+to remote target when @value{GDBN} connects to it.
+
@kindex set tcp
@kindex show tcp
@item set tcp auto-retry on
@tab @code{qXfer:siginfo:write}
@tab @code{set $_siginfo}
+@item @code{threads}
+@tab @code{qXfer:threads:read}
+@tab @code{info threads}
+
@item @code{get-thread-local-@*storage-address}
@tab @code{qGetTLSAddr}
@tab Displaying @code{__thread} variables
@cindex Cygwin-specific commands
@value{GDBN} supports native debugging of MS Windows programs, including
-DLLs with and without symbolic debugging information. There are various
-additional Cygwin-specific commands, described in this section.
-Working with DLLs that have no debugging symbols is described in
-@ref{Non-debug DLL Symbols}.
+DLLs with and without symbolic debugging information.
+
+@cindex Ctrl-BREAK, MS-Windows
+@cindex interrupt debuggee on MS-Windows
+MS-Windows programs that call @code{SetConsoleMode} to switch off the
+special meaning of the @samp{Ctrl-C} keystroke cannot be interrupted
+by typing @kbd{C-c}. For this reason, @value{GDBN} on MS-Windows
+supports @kbd{C-@key{BREAK}} as an alternative interrupt key
+sequence, which can be used to interrupt the debuggee even if it
+ignores @kbd{C-c}.
+
+There are various additional Cygwin-specific commands, described in
+this section. Working with DLLs that have no debugging symbols is
+described in @ref{Non-debug DLL Symbols}.
@table @code
@kindex info w32
@item set new-console @var{mode}
If @var{mode} is @code{on} the debuggee will
be started in a new console on next start.
-If @var{mode} is @code{off}i, the debuggee will
+If @var{mode} is @code{off}, the debuggee will
be started in the same console as the debugger.
@kindex show new-console
* ARM:: ARM RDI
* M32R/D:: Renesas M32R/D
* M68K:: Motorola M68K
+* MicroBlaze:: Xilinx MicroBlaze
* MIPS Embedded:: MIPS Embedded
* OpenRISC 1000:: OpenRisc 1000
* PA:: HP PA Embedded
@end table
+@node MicroBlaze
+@subsection MicroBlaze
+@cindex Xilinx MicroBlaze
+@cindex XMD, Xilinx Microprocessor Debugger
+
+The MicroBlaze is a soft-core processor supported on various Xilinx
+FPGAs, such as Spartan or Virtex series. Boards with these processors
+usually have JTAG ports which connect to a host system running the Xilinx
+Embedded Development Kit (EDK) or Software Development Kit (SDK).
+This host system is used to download the configuration bitstream to
+the target FPGA. The Xilinx Microprocessor Debugger (XMD) program
+communicates with the target board using the JTAG interface and
+presents a @code{gdbserver} interface to the board. By default
+@code{xmd} uses port @code{1234}. (While it is possible to change
+this default port, it requires the use of undocumented @code{xmd}
+commands. Contact Xilinx support if you need to do this.)
+
+Use these GDB commands to connect to the MicroBlaze target processor.
+
+@table @code
+@item target remote :1234
+Use this command to connect to the target if you are running @value{GDBN}
+on the same system as @code{xmd}.
+
+@item target remote @var{xmd-host}:1234
+Use this command to connect to the target if it is connected to @code{xmd}
+running on a different system named @var{xmd-host}.
+
+@item load
+Use this command to download a program to the MicroBlaze target.
+
+@item set debug microblaze @var{n}
+Enable MicroBlaze-specific debugging messages if non-zero.
+
+@item show debug microblaze @var{n}
+Show MicroBlaze-specific debugging level.
+@end table
+
@node MIPS Embedded
@subsection MIPS Embedded
* ABI:: Configuring the current ABI
* Messages/Warnings:: Optional warnings and messages
* Debugging Output:: Optional messages about internal happenings
+* Other Misc Settings:: Other Miscellaneous Settings
@end menu
@node Prompt
@itemx set pagination off
@kindex set pagination
Turn the output pagination on or off; the default is on. Turning
-pagination off is the alternative to @code{set height 0}.
+pagination off is the alternative to @code{set height 0}. Note that
+running @value{GDBN} with the @option{--batch} option (@pxref{Mode
+Options, -batch}) also automatically disables pagination.
@item show pagination
@kindex show pagination
@cindex confirmation
@cindex stupid questions
@item set confirm off
-Disables confirmation requests.
+Disables confirmation requests. Note that running @value{GDBN} with
+the @option{--batch} option (@pxref{Mode Options, -batch}) also
+automatically disables confirmation requests.
@item set confirm on
Enables confirmation requests (the default).
@item show debug overload
Displays the current state of displaying @value{GDBN} C@t{++} overload
debugging info.
+@cindex expression parser, debugging info
+@cindex debug expression parser
+@item set debug parser
+Turns on or off the display of expression parser debugging output.
+Internally, this sets the @code{yydebug} variable in the expression
+parser. @xref{Tracing, , Tracing Your Parser, bison, Bison}, for
+details. The default is off.
+@item show debug parser
+Show the current state of expression parser debugging.
@cindex packets, reporting on stdout
@cindex serial connections, debugging
@cindex debug remote protocol
Displays the current state of XML debugging messages.
@end table
+@node Other Misc Settings
+@section Other Miscellaneous Settings
+@cindex miscellaneous settings
+
+@table @code
+@kindex set interactive-mode
+@item set interactive-mode
+If @code{on}, forces @value{GDBN} to operate interactively.
+If @code{off}, forces @value{GDBN} to operate non-interactively,
+If @code{auto} (the default), @value{GDBN} guesses which mode to use,
+based on whether the debugger was started in a terminal or not.
+
+In the vast majority of cases, the debugger should be able to guess
+correctly which mode should be used. But this setting can be useful
+in certain specific cases, such as running a MinGW @value{GDBN}
+inside a cygwin window.
+
+@kindex show interactive-mode
+@item show interactive-mode
+Displays whether the debugger is operating in interactive mode or not.
+@end table
+
@node Extending GDB
@chapter Extending @value{GDBN}
@cindex extending GDB
on composition of @value{GDBN} commands, and the second is based on the
Python scripting language.
+To facilitate the use of these extensions, @value{GDBN} is capable
+of evaluating the contents of a file. When doing so, @value{GDBN}
+can recognize which scripting language is being used by looking at
+the filename extension. Files with an unrecognized filename extension
+are always treated as a @value{GDBN} Command Files.
+@xref{Command Files,, Command files}.
+
+You can control how @value{GDBN} evaluates these files with the following
+setting:
+
+@table @code
+@kindex set script-extension
+@kindex show script-extension
+@item set script-extension off
+All scripts are always evaluated as @value{GDBN} Command Files.
+
+@item set script-extension soft
+The debugger determines the scripting language based on filename
+extension. If this scripting language is supported, @value{GDBN}
+evaluates the script using that language. Otherwise, it evaluates
+the file as a @value{GDBN} Command File.
+
+@item set script-extension strict
+The debugger determines the scripting language based on filename
+extension, and evaluates the script using that language. If the
+language is not supported, then the evaluation fails.
+
+@item show script-extension
+Display the current value of the @code{script-extension} option.
+
+@end table
+
@menu
* Sequences:: Canned Sequences of Commands
* Python:: Scripting @value{GDBN} using Python
terminal.
You can request the execution of a command file with the @code{source}
-command:
+command. Note that the @code{source} command is also used to evaluate
+scripts that are not Command Files. The exact behavior can be configured
+using the @code{script-extension} setting.
+@xref{Extending GDB,, Extending GDB}.
@table @code
@kindex source
disabled.
@end table
+It is also possible to execute a Python script from the @value{GDBN}
+interpreter:
+
+@table @code
+@item source @file{script-name}
+The script name must end with @samp{.py} and @value{GDBN} must be configured
+to recognize the script language based on filename extension using
+the @code{script-extension} setting. @xref{Extending GDB, ,Extending GDB}.
+
+@item python execfile ("script-name")
+This method is based on the @code{execfile} Python built-in function,
+and thus is always available.
+@end table
+
@node Python API
@subsection Python API
@cindex python api
* Commands In Python:: Implementing new commands in Python.
* Functions In Python:: Writing new convenience functions.
* Objfiles In Python:: Object files.
-* Frames In Python:: Acessing inferior stack frames from Python.
+* Frames In Python:: Accessing inferior stack frames from Python.
+* Blocks In Python:: Accessing frame blocks from Python.
+* Symbols In Python:: Python representation of symbols.
+* Symbol Tables In Python:: Python representation of symbol tables.
+* Lazy Strings In Python:: Python representation of lazy strings.
@end menu
@node Basic Python
@code{gdb.Value} (@pxref{Values From Inferior}).
@end defun
+@findex gdb.parse_and_eval
+@defun parse_and_eval expression
+Parse @var{expression} as an expression in the current language,
+evaluate it, and return the result as a @code{gdb.Value}.
+@var{expression} must be a string.
+
+This function can be useful when implementing a new command
+(@pxref{Commands In Python}), as it provides a way to parse the
+command's argument as an expression. It is also useful simply to
+compute values, for example, it is the only way to get the value of a
+convenience variable (@pxref{Convenience Vars}) as a @code{gdb.Value}.
+@end defun
+
@findex gdb.write
@defun write string
Print a string to @value{GDBN}'s paginated standard output stream.
function.
@end defun
+@findex gdb.target_charset
+@defun target_charset
+Return the name of the current target character set (@pxref{Character
+Sets}). This differs from @code{gdb.parameter('target-charset')} in
+that @samp{auto} is never returned.
+@end defun
+
+@findex gdb.target_wide_charset
+@defun target_wide_charset
+Return the name of the current target wide character set
+(@pxref{Character Sets}). This differs from
+@code{gdb.parameter('target-wide-charset')} in that @samp{auto} is
+never returned.
+@end defun
+
@node Exception Handling
@subsubsection Exception Handling
@cindex python exceptions
If this file does not exist, and if the parameter
@code{debug-file-directory} is set (@pxref{Separate Debug Files}),
-then @value{GDBN} will use the file named
-@file{@var{debug-file-directory}/@var{real-name}}, where
+then @value{GDBN} will use for its each separated directory component
+@code{component} the file named @file{@code{component}/@var{real-name}}, where
@var{real-name} is the object file's real name, as described above.
Finally, if this file does not exist, then @value{GDBN} will look for
The following methods are provided:
@table @code
+@defmethod Value cast type
+Return a new instance of @code{gdb.Value} that is the result of
+casting this instance to the type described by @var{type}, which must
+be a @code{gdb.Type} object. If the cast cannot be performed for some
+reason, this method throws an exception.
+@end defmethod
+
@defmethod Value dereference
For pointer data types, this method returns a new @code{gdb.Value} object
whose contents is the object pointed to by the pointer. For example, if
If the optional @var{length} argument is given, the string will be
fetched and converted to the given length.
@end defmethod
+
+@defmethod Value lazy_string @r{[}encoding@r{]} @r{[}length@r{]}
+If this @code{gdb.Value} represents a string, then this method
+converts the contents to a @code{gdb.LazyString} (@pxref{Lazy Strings
+In Python}). Otherwise, this method will throw an exception.
+
+If the optional @var{encoding} argument is given, it must be a string
+naming the encoding of the @code{gdb.LazyString}. Some examples are:
+@samp{ascii}, @samp{iso-8859-6} or @samp{utf-8}. If the
+@var{encoding} argument is an encoding that @value{GDBN} does
+recognize, @value{GDBN} will raise an error.
+
+When a lazy string is printed, the @value{GDBN} encoding machinery is
+used to convert the string during printing. If the optional
+@var{encoding} argument is not provided, or is an empty string,
+@value{GDBN} will automatically select the encoding most suitable for
+the string type. For further information on encoding in @value{GDBN}
+please see @ref{Character Sets}.
+
+If the optional @var{length} argument is given, the string will be
+fetched and encoded to the length of characters specified. If
+the @var{length} argument is not provided, the string will be fetched
+and encoded until a null of appropriate width is found.
+@end defmethod
@end table
@node Types In Python
This function looks up a type by name. @var{name} is the name of the
type to look up. It must be a string.
+If @var{block} is given, then @var{name} is looked up in that scope.
+Otherwise, it is searched for globally.
+
Ordinarily, this function will return an instance of @code{gdb.Type}.
If the named type cannot be found, it will throw an exception.
@end defun
it was provided by the compiler and not the user. This attribute is
always provided, and is @code{False} if the field is not artificial.
+@item is_base_class
+This is @code{True} if the field represents a base class of a C@t{++}
+structure. This attribute is always provided, and is @code{False}
+if the field is not a base class of the type that is the argument of
+@code{fields}, or if that type was not a C@t{++} class.
+
@item bitsize
If the field is packed, or is a bitfield, then this will have a
non-zero value, which is the size of the field in bits. Otherwise,
@code{volatile}.
@end defmethod
+@defmethod Type range
+Return a Python @code{Tuple} object that contains two elements: the
+low bound of the argument type and the high bound of that type. If
+the type does not have a range, @value{GDBN} will raise a
+@code{RuntimeError} exception.
+@end defmethod
+
@defmethod Type reference
Return a new @code{gdb.Type} object which represents a reference to this
type.
@end defmethod
+@defmethod Type pointer
+Return a new @code{gdb.Type} object which represents a pointer to this
+type.
+@end defmethod
+
@defmethod Type strip_typedefs
Return a new @code{gdb.Type} that represents the real type,
after removing all layers of typedefs.
exception.
@end defmethod
-@defmethod Type template_argument n
+@defmethod Type template_argument n [block]
If this @code{gdb.Type} is an instantiation of a template, this will
return a new @code{gdb.Type} which represents the type of the
@var{n}th template argument.
If this @code{gdb.Type} is not a template type, this will throw an
exception. Ordinarily, only C@t{++} code will have template types.
-@var{name} is searched for globally.
+If @var{block} is given, then @var{name} is looked up in that scope.
+Otherwise, it is searched for globally.
@end defmethod
@end table
@end defivar
@node Frames In Python
-@subsubsection Acessing inferior stack frames from Python.
+@subsubsection Accessing inferior stack frames from Python.
@cindex frames in python
When the debugged program stops, @value{GDBN} is able to analyze its call
Returns the frame's resume address.
@end defmethod
+@defmethod Frame block
+Return the frame's code block. @xref{Blocks In Python}.
+@end defmethod
+
+@defmethod Frame function
+Return the symbol for the function corresponding to this frame.
+@xref{Symbols In Python}.
+@end defmethod
+
@defmethod Frame older
Return the frame that called this frame.
@end defmethod
Return the frame called by this frame.
@end defmethod
-@defmethod Frame read_var variable
-Return the value of the given variable in this frame. @var{variable} must
-be a string.
+@defmethod Frame find_sal
+Return the frame's symtab and line object.
+@xref{Symbol Tables In Python}.
+@end defmethod
+
+@defmethod Frame read_var variable @r{[}block@r{]}
+Return the value of @var{variable} in this frame. If the optional
+argument @var{block} is provided, search for the variable from that
+block; otherwise start at the frame's current block (which is
+determined by the frame's current program counter). @var{variable}
+must be a string or a @code{gdb.Symbol} object. @var{block} must be a
+@code{gdb.Block} object.
+@end defmethod
+
+@defmethod Frame select
+Set this frame to be the selected frame. @xref{Stack, ,Examining the
+Stack}.
@end defmethod
@end table
-@node Interpreters
-@chapter Command Interpreters
-@cindex command interpreters
+@node Blocks In Python
+@subsubsection Accessing frame blocks from Python.
-@value{GDBN} supports multiple command interpreters, and some command
-infrastructure to allow users or user interface writers to switch
-between interpreters or run commands in other interpreters.
+@cindex blocks in python
+@tindex gdb.Block
-@value{GDBN} currently supports two command interpreters, the console
-interpreter (sometimes called the command-line interpreter or @sc{cli})
-and the machine interface interpreter (or @sc{gdb/mi}). This manual
-describes both of these interfaces in great detail.
+Within each frame, @value{GDBN} maintains information on each block
+stored in that frame. These blocks are organized hierarchically, and
+are represented individually in Python as a @code{gdb.Block}.
+Please see @ref{Frames In Python}, for a more in-depth discussion on
+frames. Furthermore, see @ref{Stack, ,Examining the Stack}, for more
+detailed technical information on @value{GDBN}'s book-keeping of the
+stack.
+
+The following block-related functions are available in the @code{gdb}
+module:
+
+@findex gdb.block_for_pc
+@defun block_for_pc pc
+Return the @code{gdb.Block} containing the given @var{pc} value. If the
+block cannot be found for the @var{pc} value specified, the function
+will return @code{None}.
+@end defun
+
+A @code{gdb.Block} object has the following attributes:
+
+@table @code
+@defivar Block start
+The start address of the block. This attribute is not writable.
+@end defivar
+
+@defivar Block end
+The end address of the block. This attribute is not writable.
+@end defivar
+
+@defivar Block function
+The name of the block represented as a @code{gdb.Symbol}. If the
+block is not named, then this attribute holds @code{None}. This
+attribute is not writable.
+@end defivar
+
+@defivar Block superblock
+The block containing this block. If this parent block does not exist,
+this attribute holds @code{None}. This attribute is not writable.
+@end defivar
+@end table
+
+@node Symbols In Python
+@subsubsection Python representation of Symbols.
+
+@cindex symbols in python
+@tindex gdb.Symbol
+
+@value{GDBN} represents every variable, function and type as an
+entry in a symbol table. @xref{Symbols, ,Examining the Symbol Table}.
+Similarly, Python represents these symbols in @value{GDBN} with the
+@code{gdb.Symbol} object.
+
+The following symbol-related functions are available in the @code{gdb}
+module:
+
+@findex gdb.lookup_symbol
+@defun lookup_symbol name [block] [domain]
+This function searches for a symbol by name. The search scope can be
+restricted to the parameters defined in the optional domain and block
+arguments.
+
+@var{name} is the name of the symbol. It must be a string. The
+optional @var{block} argument restricts the search to symbols visible
+in that @var{block}. The @var{block} argument must be a
+@code{gdb.Block} object. The optional @var{domain} argument restricts
+the search to the domain type. The @var{domain} argument must be a
+domain constant defined in the @code{gdb} module and described later
+in this chapter.
+@end defun
+
+A @code{gdb.Symbol} object has the following attributes:
+
+@table @code
+@defivar Symbol symtab
+The symbol table in which the symbol appears. This attribute is
+represented as a @code{gdb.Symtab} object. @xref{Symbol Tables In
+Python}. This attribute is not writable.
+@end defivar
+
+@defivar Symbol name
+The name of the symbol as a string. This attribute is not writable.
+@end defivar
+
+@defivar Symbol linkage_name
+The name of the symbol, as used by the linker (i.e., may be mangled).
+This attribute is not writable.
+@end defivar
+
+@defivar Symbol print_name
+The name of the symbol in a form suitable for output. This is either
+@code{name} or @code{linkage_name}, depending on whether the user
+asked @value{GDBN} to display demangled or mangled names.
+@end defivar
+
+@defivar Symbol addr_class
+The address class of the symbol. This classifies how to find the value
+of a symbol. Each address class is a constant defined in the
+@code{gdb} module and described later in this chapter.
+@end defivar
+
+@defivar Symbol is_argument
+@code{True} if the symbol is an argument of a function.
+@end defivar
+
+@defivar Symbol is_constant
+@code{True} if the symbol is a constant.
+@end defivar
+
+@defivar Symbol is_function
+@code{True} if the symbol is a function or a method.
+@end defivar
+
+@defivar Symbol is_variable
+@code{True} if the symbol is a variable.
+@end defivar
+@end table
+
+The available domain categories in @code{gdb.Symbol} are represented
+as constants in the @code{gdb} module:
+
+@table @code
+@findex SYMBOL_UNDEF_DOMAIN
+@findex gdb.SYMBOL_UNDEF_DOMAIN
+@item SYMBOL_UNDEF_DOMAIN
+This is used when a domain has not been discovered or none of the
+following domains apply. This usually indicates an error either
+in the symbol information or in @value{GDBN}'s handling of symbols.
+@findex SYMBOL_VAR_DOMAIN
+@findex gdb.SYMBOL_VAR_DOMAIN
+@item SYMBOL_VAR_DOMAIN
+This domain contains variables, function names, typedef names and enum
+type values.
+@findex SYMBOL_STRUCT_DOMAIN
+@findex gdb.SYMBOL_STRUCT_DOMAIN
+@item SYMBOL_STRUCT_DOMAIN
+This domain holds struct, union and enum type names.
+@findex SYMBOL_LABEL_DOMAIN
+@findex gdb.SYMBOL_LABEL_DOMAIN
+@item SYMBOL_LABEL_DOMAIN
+This domain contains names of labels (for gotos).
+@findex SYMBOL_VARIABLES_DOMAIN
+@findex gdb.SYMBOL_VARIABLES_DOMAIN
+@item SYMBOL_VARIABLES_DOMAIN
+This domain holds a subset of the @code{SYMBOLS_VAR_DOMAIN}; it
+contains everything minus functions and types.
+@findex SYMBOL_FUNCTIONS_DOMAIN
+@findex gdb.SYMBOL_FUNCTIONS_DOMAIN
+@item SYMBOL_FUNCTION_DOMAIN
+This domain contains all functions.
+@findex SYMBOL_TYPES_DOMAIN
+@findex gdb.SYMBOL_TYPES_DOMAIN
+@item SYMBOL_TYPES_DOMAIN
+This domain contains all types.
+@end table
+
+The available address class categories in @code{gdb.Symbol} are represented
+as constants in the @code{gdb} module:
+
+@table @code
+@findex SYMBOL_LOC_UNDEF
+@findex gdb.SYMBOL_LOC_UNDEF
+@item SYMBOL_LOC_UNDEF
+If this is returned by address class, it indicates an error either in
+the symbol information or in @value{GDBN}'s handling of symbols.
+@findex SYMBOL_LOC_CONST
+@findex gdb.SYMBOL_LOC_CONST
+@item SYMBOL_LOC_CONST
+Value is constant int.
+@findex SYMBOL_LOC_STATIC
+@findex gdb.SYMBOL_LOC_STATIC
+@item SYMBOL_LOC_STATIC
+Value is at a fixed address.
+@findex SYMBOL_LOC_REGISTER
+@findex gdb.SYMBOL_LOC_REGISTER
+@item SYMBOL_LOC_REGISTER
+Value is in a register.
+@findex SYMBOL_LOC_ARG
+@findex gdb.SYMBOL_LOC_ARG
+@item SYMBOL_LOC_ARG
+Value is an argument. This value is at the offset stored within the
+symbol inside the frame's argument list.
+@findex SYMBOL_LOC_REF_ARG
+@findex gdb.SYMBOL_LOC_REF_ARG
+@item SYMBOL_LOC_REF_ARG
+Value address is stored in the frame's argument list. Just like
+@code{LOC_ARG} except that the value's address is stored at the
+offset, not the value itself.
+@findex SYMBOL_LOC_REGPARM_ADDR
+@findex gdb.SYMBOL_LOC_REGPARM_ADDR
+@item SYMBOL_LOC_REGPARM_ADDR
+Value is a specified register. Just like @code{LOC_REGISTER} except
+the register holds the address of the argument instead of the argument
+itself.
+@findex SYMBOL_LOC_LOCAL
+@findex gdb.SYMBOL_LOC_LOCAL
+@item SYMBOL_LOC_LOCAL
+Value is a local variable.
+@findex SYMBOL_LOC_TYPEDEF
+@findex gdb.SYMBOL_LOC_TYPEDEF
+@item SYMBOL_LOC_TYPEDEF
+Value not used. Symbols in the domain @code{SYMBOL_STRUCT_DOMAIN} all
+have this class.
+@findex SYMBOL_LOC_BLOCK
+@findex gdb.SYMBOL_LOC_BLOCK
+@item SYMBOL_LOC_BLOCK
+Value is a block.
+@findex SYMBOL_LOC_CONST_BYTES
+@findex gdb.SYMBOL_LOC_CONST_BYTES
+@item SYMBOL_LOC_CONST_BYTES
+Value is a byte-sequence.
+@findex SYMBOL_LOC_UNRESOLVED
+@findex gdb.SYMBOL_LOC_UNRESOLVED
+@item SYMBOL_LOC_UNRESOLVED
+Value is at a fixed address, but the address of the variable has to be
+determined from the minimal symbol table whenever the variable is
+referenced.
+@findex SYMBOL_LOC_OPTIMIZED_OUT
+@findex gdb.SYMBOL_LOC_OPTIMIZED_OUT
+@item SYMBOL_LOC_OPTIMIZED_OUT
+The value does not actually exist in the program.
+@findex SYMBOL_LOC_COMPUTED
+@findex gdb.SYMBOL_LOC_COMPUTED
+@item SYMBOL_LOC_COMPUTED
+The value's address is a computed location.
+@end table
+
+@node Symbol Tables In Python
+@subsubsection Symbol table representation in Python.
+
+@cindex symbol tables in python
+@tindex gdb.Symtab
+@tindex gdb.Symtab_and_line
+
+Access to symbol table data maintained by @value{GDBN} on the inferior
+is exposed to Python via two objects: @code{gdb.Symtab_and_line} and
+@code{gdb.Symtab}. Symbol table and line data for a frame is returned
+from the @code{find_sal} method in @code{gdb.Frame} object.
+@xref{Frames In Python}.
+
+For more information on @value{GDBN}'s symbol table management, see
+@ref{Symbols, ,Examining the Symbol Table}, for more information.
+
+A @code{gdb.Symtab_and_line} object has the following attributes:
+
+@table @code
+@defivar Symtab_and_line symtab
+The symbol table object (@code{gdb.Symtab}) for this frame.
+This attribute is not writable.
+@end defivar
+
+@defivar Symtab_and_line pc
+Indicates the current program counter address. This attribute is not
+writable.
+@end defivar
+
+@defivar Symtab_and_line line
+Indicates the current line number for this object. This
+attribute is not writable.
+@end defivar
+@end table
+
+A @code{gdb.Symtab} object has the following attributes:
+
+@table @code
+@defivar Symtab filename
+The symbol table's source filename. This attribute is not writable.
+@end defivar
+
+@defivar Symtab objfile
+The symbol table's backing object file. @xref{Objfiles In Python}.
+This attribute is not writable.
+@end defivar
+@end table
+
+The following methods are provided:
+
+@table @code
+@defmethod Symtab fullname
+Return the symbol table's source absolute file name.
+@end defmethod
+@end table
+
+@node Lazy Strings In Python
+@subsubsection Python representation of lazy strings.
+
+@cindex lazy strings in python
+@tindex gdb.LazyString
+
+A @dfn{lazy string} is a string whose contents is not retrieved or
+encoded until it is needed.
+
+A @code{gdb.LazyString} is represented in @value{GDBN} as an
+@code{address} that points to a region of memory, an @code{encoding}
+that will be used to encode that region of memory, and a @code{length}
+to delimit the region of memory that represents the string. The
+difference between a @code{gdb.LazyString} and a string wrapped within
+a @code{gdb.Value} is that a @code{gdb.LazyString} will be treated
+differently by @value{GDBN} when printing. A @code{gdb.LazyString} is
+retrieved and encoded during printing, while a @code{gdb.Value}
+wrapping a string is immediately retrieved and encoded on creation.
+
+A @code{gdb.LazyString} object has the following functions:
+
+@defmethod LazyString value
+Convert the @code{gdb.LazyString} to a @code{gdb.Value}. This value
+will point to the string in memory, but will lose all the delayed
+retrieval, encoding and handling that @value{GDBN} applies to a
+@code{gdb.LazyString}.
+@end defmethod
+
+@defivar LazyString address
+This attribute holds the address of the string. This attribute is not
+writable.
+@end defivar
+
+@defivar LazyString length
+This attribute holds the length of the string in characters. If the
+length is -1, then the string will be fetched and encoded up to the
+first null of appropriate width. This attribute is not writable.
+@end defivar
+
+@defivar LazyString encoding
+This attribute holds the encoding that will be applied to the string
+when the string is printed by @value{GDBN}. If the encoding is not
+set, or contains an empty string, then @value{GDBN} will select the
+most appropriate encoding when the string is printed. This attribute
+is not writable.
+@end defivar
+
+@defivar LazyString type
+This attribute holds the type that is represented by the lazy string's
+type. For a lazy string this will always be a pointer type. To
+resolve this to the lazy string's character type, use the type's
+@code{target} method. @xref{Types In Python}. This attribute is not
+writable.
+@end defivar
+
+@node Interpreters
+@chapter Command Interpreters
+@cindex command interpreters
+
+@value{GDBN} supports multiple command interpreters, and some command
+infrastructure to allow users or user interface writers to switch
+between interpreters or run commands in other interpreters.
+
+@value{GDBN} currently supports two command interpreters, the console
+interpreter (sometimes called the command-line interpreter or @sc{cli})
+and the machine interface interpreter (or @sc{gdb/mi}). This manual
+describes both of these interfaces in great detail.
By default, @value{GDBN} will start with the console interpreter.
However, the user may choose to start @value{GDBN} with another
In general, the content of a thread group may be only retrieved only
after attaching to that thread group.
+Thread groups are related to inferiors (@pxref{Inferiors and
+Programs}). Each inferior corresponds to a thread group of a special
+type @samp{process}, and some additional operations are permitted on
+such thread groups.
+
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Command Syntax
@section @sc{gdb/mi} Command Syntax
* GDB/MI Stream Records::
* GDB/MI Async Records::
* GDB/MI Frame Information::
+* GDB/MI Thread Information::
@end menu
@node GDB/MI Result Records
@item "^running"
@findex ^running
-@c Is this one correct? Should it be an out-of-band notification?
-The asynchronous operation was successfully started. The target is
-running.
+This result record is equivalent to @samp{^done}. Historically, it
+was output instead of @samp{^done} if the command has resumed the
+target. This behaviour is maintained for backward compatibility, but
+all frontends should treat @samp{^done} and @samp{^running}
+identically and rely on the @samp{*running} output record to determine
+which threads are resumed.
@item "^connected"
@findex ^connected
all threads together, or even for a single thread, if the thread must
be stepped though some code before letting it run freely.
-@item *stopped,reason="@var{reason}",thread-id="@var{id}",stopped-threads="@var{stopped}"
+@item *stopped,reason="@var{reason}",thread-id="@var{id}",stopped-threads="@var{stopped}",core="@var{core}"
The target has stopped. The @var{reason} field can have one of the
following values:
value of @code{"all"}. Otherwise, the value of the @var{stopped}
field will be a list of thread identifiers. Presently, this list will
always include a single thread, but frontend should be prepared to see
-several threads in the list.
+several threads in the list. The @var{core} field reports the
+processor core on which the stop event has happened. This field may be absent
+if such information is not available.
+
+@item =thread-group-added,id="@var{id}"
+@itemx =thread-group-removed,id="@var{id}"
+A thread group was either added or removed. The @var{id} field
+contains the @value{GDBN} identifier of the thread group. When a thread
+group is added, it generally might not be associated with a running
+process. When a thread group is removed, its id becomes invalid and
+cannot be used in any way.
+
+@item =thread-group-started,id="@var{id}",pid="@var{pid}"
+A thread group became associated with a running program,
+either because the program was just started or the thread group
+was attached to a program. The @var{id} field contains the
+@value{GDBN} identifier of the thread group. The @var{pid} field
+contains process identifier, specific to the operating system.
-@item =thread-group-created,id="@var{id}"
@itemx =thread-group-exited,id="@var{id}"
-A thread thread group either was attached to, or has exited/detached
+A thread group is no longer associated with a running program,
+either because the program has exited, or because it was detached
from. The @var{id} field contains the @value{GDBN} identifier of the
thread group.
library file on the target, and on the host respectively. For native
debugging, both those fields have the same value. The
@var{symbols-loaded} field reports if the debug symbols for this
-library are loaded.
+library are loaded. The @var{thread-group} field, if present,
+specifies the id of the thread group in whose context the library was loaded.
+If the field is absent, it means the library was loaded in the context
+of all present thread groups.
@item =library-unloaded,...
Reports that a library was unloaded by the program. This notification
has 3 fields---@var{id}, @var{target-name} and @var{host-name} with
-the same meaning as for the @code{=library-loaded} notification
+the same meaning as for the @code{=library-loaded} notification.
+The @var{thread-group} field, if present, specifies the id of the
+thread group in whose context the library was unloaded. If the field is
+absent, it means the library was unloaded in the context of all present
+thread groups.
@end table
@end table
+@node GDB/MI Thread Information
+@subsection @sc{gdb/mi} Thread Information
+
+Whenever @value{GDBN} has to report an information about a thread, it
+uses a tuple with the following fields:
+
+@table @code
+@item id
+The numeric id assigned to the thread by @value{GDBN}. This field is
+always present.
+
+@item target-id
+Target-specific string identifying the thread. This field is always present.
+
+@item details
+Additional information about the thread provided by the target.
+It is supposed to be human-readable and not interpreted by the
+frontend. This field is optional.
+
+@item state
+Either @samp{stopped} or @samp{running}, depending on whether the
+thread is presently running. This field is always present.
+
+@item core
+The value of this field is an integer number of the processor core the
+thread was last seen on. This field is optional.
+@end table
+
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Simple Examples
<- ^exit
@end smallexample
+Please note that @samp{^exit} is printed immediately, but it might
+take some time for @value{GDBN} to actually exit. During that time, @value{GDBN}
+performs necessary cleanups, including killing programs being debugged
+or disconnecting from debug hardware, so the frontend should wait till
+@value{GDBN} exits and should only forcibly kill @value{GDBN} if it
+fails to exit in reasonable time.
+
@subheading A Bad Command
Here's what happens if you pass a non-existent command:
@subsubheading Synopsis
@smallexample
- -exec-continue [--all|--thread-group N]
+ -exec-continue [--reverse] [--all|--thread-group N]
@end smallexample
-Resumes the execution of the inferior program until a breakpoint is
-encountered, or until the inferior exits. In all-stop mode
-(@pxref{All-Stop Mode}), may resume only one thread, or all threads,
-depending on the value of the @samp{scheduler-locking} variable. In
-non-stop mode (@pxref{Non-Stop Mode}), if the @samp{--all} is not
-specified, only the thread specified with the @samp{--thread} option
-(or current thread, if no @samp{--thread} is provided) is resumed. If
-@samp{--all} is specified, all threads will be resumed. The
-@samp{--all} option is ignored in all-stop mode. If the
-@samp{--thread-group} options is specified, then all threads in that
-thread group are resumed.
+Resumes the execution of the inferior program, which will continue
+to execute until it reaches a debugger stop event. If the
+@samp{--reverse} option is specified, execution resumes in reverse until
+it reaches a stop event. Stop events may include
+@itemize @bullet
+@item
+breakpoints or watchpoints
+@item
+signals or exceptions
+@item
+the end of the process (or its beginning under @samp{--reverse})
+@item
+the end or beginning of a replay log if one is being used.
+@end itemize
+In all-stop mode (@pxref{All-Stop
+Mode}), may resume only one thread, or all threads, depending on the
+value of the @samp{scheduler-locking} variable. If @samp{--all} is
+specified, all threads (in all inferiors) will be resumed. The @samp{--all} option is
+ignored in all-stop mode. If the @samp{--thread-group} options is
+specified, then all threads in that thread group are resumed.
@subsubheading @value{GDBN} Command
@subsubheading Synopsis
@smallexample
- -exec-finish
+ -exec-finish [--reverse]
@end smallexample
Resumes the execution of the inferior program until the current
function is exited. Displays the results returned by the function.
+If the @samp{--reverse} option is specified, resumes the reverse
+execution of the inferior program until the point where current
+function was called.
@subsubheading @value{GDBN} Command
reported after that using the @samp{*stopped} notification.
In non-stop mode, only the context thread is interrupted by default.
-All threads will be interrupted if the @samp{--all} option is
-specified. If the @samp{--thread-group} option is specified, all
-threads in that group will be interrupted.
+All threads (in all inferiors) will be interrupted if the
+@samp{--all} option is specified. If the @samp{--thread-group}
+option is specified, all threads in that group will be interrupted.
@subsubheading @value{GDBN} Command
@subsubheading Synopsis
@smallexample
- -exec-next
+ -exec-next [--reverse]
@end smallexample
Resumes execution of the inferior program, stopping when the beginning
of the next source line is reached.
+If the @samp{--reverse} option is specified, resumes reverse execution
+of the inferior program, stopping at the beginning of the previous
+source line. If you issue this command on the first line of a
+function, it will take you back to the caller of that function, to the
+source line where the function was called.
+
+
@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{next}.
@subsubheading Synopsis
@smallexample
- -exec-next-instruction
+ -exec-next-instruction [--reverse]
@end smallexample
Executes one machine instruction. If the instruction is a function
instruction in the middle of a source line, the address will be
printed as well.
+If the @samp{--reverse} option is specified, resumes reverse execution
+of the inferior program, stopping at the previous instruction. If the
+previously executed instruction was a return from another function,
+it will continue to execute in reverse until the call to that function
+(from the current stack frame) is reached.
+
@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{nexti}.
@subsubheading Synopsis
@smallexample
- -exec-run
+ -exec-run [--all | --thread-group N]
@end smallexample
Starts execution of the inferior from the beginning. The inferior
exits. In the latter case the output will include an exit code, if
the program has exited exceptionally.
+When no option is specified, the current inferior is started. If the
+@samp{--thread-group} option is specified, it should refer to a thread
+group of type @samp{process}, and that thread group will be started.
+If the @samp{--all} option is specified, then all inferiors will be started.
+
@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{run}.
@subsubheading Synopsis
@smallexample
- -exec-step
+ -exec-step [--reverse]
@end smallexample
Resumes execution of the inferior program, stopping when the beginning
of the next source line is reached, if the next source line is not a
function call. If it is, stop at the first instruction of the called
-function.
+function. If the @samp{--reverse} option is specified, resumes reverse
+execution of the inferior program, stopping at the beginning of the
+previously executed source line.
@subsubheading @value{GDBN} Command
@subsubheading Synopsis
@smallexample
- -exec-step-instruction
+ -exec-step-instruction [--reverse]
@end smallexample
-Resumes the inferior which executes one machine instruction. The
-output, once @value{GDBN} has stopped, will vary depending on whether
-we have stopped in the middle of a source line or not. In the former
-case, the address at which the program stopped will be printed as
-well.
+Resumes the inferior which executes one machine instruction. If the
+@samp{--reverse} option is specified, resumes reverse execution of the
+inferior program, stopping at the previously executed instruction.
+The output, once @value{GDBN} has stopped, will vary depending on
+whether we have stopped in the middle of a source line or not. In the
+former case, the address at which the program stopped will be printed
+as well.
@subsubheading @value{GDBN} Command
@subsubheading Synopsis
@smallexample
- -stack-list-arguments @var{show-values}
+ -stack-list-arguments @var{print-values}
[ @var{low-frame} @var{high-frame} ]
@end smallexample
@var{high-frame} may be larger than the actual number of frames, in
which case only existing frames will be returned.
-The @var{show-values} argument must have a value of 0 or 1. A value of
-0 means that only the names of the arguments are listed, a value of 1
-means that both names and values of the arguments are printed.
+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.
+
+Use of this command to obtain arguments in a single frame is
+deprecated in favor of the @samp{-stack-list-variables} command.
@subsubheading @value{GDBN} Command
@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,
+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 user wishes to explore their values in
more detail.
+This command is deprecated in favor of the
+@samp{-stack-list-variables} command.
+
@subsubheading @value{GDBN} Command
@samp{info locals} in @value{GDBN}, @samp{gdb_get_locals} in @code{gdbtk}.
(gdb)
@end smallexample
+@subheading The @code{-stack-list-variables} Command
+@findex -stack-list-variables
+
+@subsubheading Synopsis
+
+@smallexample
+ -stack-list-variables @var{print-values}
+@end smallexample
+
+Display the names of local variables and function arguments 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.
+
+@subsubheading Example
+
+@smallexample
+(gdb)
+-stack-list-variables --thread 1 --frame 0 --all-values
+^done,variables=[@{name="x",value="11"@},@{name="s",value="@{a = 1, b = 2@}"@}]
+(gdb)
+@end smallexample
+
@subheading The @code{-stack-select-frame} Command
@findex -stack-select-frame
@item @strong{Operation}
@tab @strong{Description}
+@item @code{-enable-pretty-printing}
+@tab enable Python-based pretty-printing
@item @code{-var-create}
@tab create a variable object
@item @code{-var-delete}
@tab update the variable and its children
@item @code{-var-set-frozen}
@tab set frozeness attribute
+@item @code{-var-set-update-range}
+@tab set range of children to display on update
@end multitable
In the next subsection we describe each operation in detail and suggest
@subheading Description And Use of Operations on Variable Objects
+@subheading The @code{-enable-pretty-printing} Command
+@findex -enable-pretty-printing
+
+@smallexample
+-enable-pretty-printing
+@end smallexample
+
+@value{GDBN} allows Python-based visualizers to affect the output of the
+MI variable object commands. However, because there was no way to
+implement this in a fully backward-compatible way, a front end must
+request that this functionality be enabled.
+
+Once enabled, this feature cannot be disabled.
+
+Note that if Python support has not been compiled into @value{GDBN},
+this command will still succeed (and do nothing).
+
+This feature is currently (as of @value{GDBN} 7.0) experimental, and
+may work differently in future versions of @value{GDBN}.
+
@subheading The @code{-var-create} Command
@findex -var-create
@samp{$@var{regname}} --- a CPU register name
@end itemize
+@cindex dynamic varobj
+A varobj's contents may be provided by a Python-based pretty-printer. In this
+case the varobj is known as a @dfn{dynamic varobj}. Dynamic varobjs
+have slightly different semantics in some cases. If the
+@code{-enable-pretty-printing} command is not sent, then @value{GDBN}
+will never create a dynamic varobj. This ensures backward
+compatibility for existing clients.
+
@subsubheading Result
-This operation returns the name, number of children and the type of the
-object created. Type is returned as a string as the ones generated by
-the @value{GDBN} CLI. If a fixed variable object is bound to a
-specific thread, the thread is is also printed:
+This operation returns attributes of the newly-created varobj. These
+are:
+
+@table @samp
+@item name
+The name of the varobj.
+
+@item numchild
+The number of children of the varobj. This number is not necessarily
+reliable for a dynamic varobj. Instead, you must examine the
+@samp{has_more} attribute.
+
+@item value
+The varobj's scalar value. For a varobj whose type is some sort of
+aggregate (e.g., a @code{struct}), or for a dynamic varobj, this value
+will not be interesting.
+
+@item type
+The varobj's type. This is a string representation of the type, as
+would be printed by the @value{GDBN} CLI.
+
+@item thread-id
+If a variable object is bound to a specific thread, then this is the
+thread's identifier.
+
+@item has_more
+For a dynamic varobj, this indicates whether there appear to be any
+children available. For a non-dynamic varobj, this will be 0.
+
+@item dynamic
+This attribute will be present and have the value @samp{1} if the
+varobj is a dynamic varobj. If the varobj is not a dynamic varobj,
+then this attribute will not be present.
+
+@item displayhint
+A dynamic varobj can supply a display hint to the front end. The
+value comes directly from the Python pretty-printer object's
+@code{display_hint} method. @xref{Pretty Printing}.
+@end table
+
+Typical output will look like this:
@smallexample
- name="@var{name}",numchild="@var{N}",type="@var{type}",thread-id="@var{M}"
+ name="@var{name}",numchild="@var{N}",type="@var{type}",thread-id="@var{M}",
+ has_more="@var{has_more}"
@end smallexample
numchild=@var{n}
@end smallexample
+Note that this number is not completely reliable for a dynamic varobj.
+It will return the current number of children, but more children may
+be available.
+
@subheading The @code{-var-list-children} Command
@findex -var-list-children
@subsubheading Synopsis
@smallexample
- -var-list-children [@var{print-values}] @var{name}
+ -var-list-children [@var{print-values}] @var{name} [@var{from} @var{to}]
@end smallexample
@anchor{-var-list-children}
value for simple data types and just the name for arrays, structures
and unions.
+@var{from} and @var{to}, if specified, indicate the range of children
+to report. If @var{from} or @var{to} is less than zero, the range is
+reset and all children will be reported. Otherwise, children starting
+at @var{from} (zero-based) and up to and excluding @var{to} will be
+reported.
+
+If a child range is requested, it will only affect the current call to
+@code{-var-list-children}, but not future calls to @code{-var-update}.
+For this, you must instead use @code{-var-set-update-range}. The
+intent of this approach is to enable a front end to implement any
+update approach it likes; for example, scrolling a view may cause the
+front end to request more children with @code{-var-list-children}, and
+then the front end could call @code{-var-set-update-range} with a
+different range to ensure that future updates are restricted to just
+the visible items.
+
For each child the following results are returned:
@table @var
The expression to be shown to the user by the front end to designate this child.
For example this may be the name of a structure member.
+For a dynamic varobj, this value cannot be used to form an
+expression. There is no way to do this at all with a dynamic varobj.
+
For C/C@t{++} structures there are several pseudo children returned to
designate access qualifiers. For these pseudo children @var{exp} is
@samp{public}, @samp{private}, or @samp{protected}. In this case the
type and value are not present.
+A dynamic varobj will not report the access qualifying
+pseudo-children, regardless of the language. This information is not
+available at all with a dynamic varobj.
+
@item numchild
-Number of children this child has.
+Number of children this child has. For a dynamic varobj, this will be
+0.
@item type
The type of the child.
If the variable object is frozen, this variable will be present with a value of 1.
@end table
+The result may have its own attributes:
+
+@table @samp
+@item displayhint
+A dynamic varobj can supply a display hint to the front end. The
+value comes directly from the Python pretty-printer object's
+@code{display_hint} method. @xref{Pretty Printing}.
+
+@item has_more
+This is an integer attribute which is nonzero if there are children
+remaining after the end of the selected range.
+@end table
+
@subsubheading Example
@smallexample
the @code{-var-info-path-expression} command is creating a
watchpoint from a variable object.
+This command is currently not valid for children of a dynamic varobj,
+and will give an error when invoked on one.
+
For example, suppose @code{C} is a C@t{++} class, derived from class
@code{Base}, and that the @code{Base} class has a member called
@code{m_size}. Assume a variable @code{c} is has the type of
currently running thread, it will not be updated, without any
diagnostic.
-@subsubheading Example
+If @code{-var-set-update-range} was previously used on a varobj, then
+only the selected range of children will be reported.
-@smallexample
-(gdb)
--var-assign var1 3
-^done,value="3"
-(gdb)
--var-update --all-values var1
-^done,changelist=[@{name="var1",value="3",in_scope="true",
-type_changed="false"@}]
-(gdb)
-@end smallexample
+@code{-var-update} reports all the changed varobjs in a tuple named
+@samp{changelist}.
+
+Each item in the change list is itself a tuple holding:
+
+@table @samp
+@item name
+The name of the varobj.
+
+@item value
+If values were requested for this update, then this field will be
+present and will hold the value of the varobj.
+@item in_scope
@anchor{-var-update}
-The field in_scope may take three values:
+This field is a string which may take one of three values:
@table @code
@item "true"
In the future new values may be added to this list so the front should
be prepared for this possibility. @xref{GDB/MI Development and Front Ends, ,@sc{GDB/MI} Development and Front Ends}.
+@item type_changed
+This is only present if the varobj is still valid. If the type
+changed, then this will be the string @samp{true}; otherwise it will
+be @samp{false}.
+
+@item new_type
+If the varobj's type changed, then this field will be present and will
+hold the new type.
+
+@item new_num_children
+For a dynamic varobj, if the number of children changed, or if the
+type changed, this will be the new number of children.
+
+The @samp{numchild} field in other varobj responses is generally not
+valid for a dynamic varobj -- it will show the number of children that
+@value{GDBN} knows about, but because dynamic varobjs lazily
+instantiate their children, this will not reflect the number of
+children which may be available.
+
+The @samp{new_num_children} attribute only reports changes to the
+number of children known by @value{GDBN}. This is the only way to
+detect whether an update has removed children (which necessarily can
+only happen at the end of the update range).
+
+@item displayhint
+The display hint, if any.
+
+@item has_more
+This is an integer value, which will be 1 if there are more children
+available outside the varobj's update range.
+
+@item dynamic
+This attribute will be present and have the value @samp{1} if the
+varobj is a dynamic varobj. If the varobj is not a dynamic varobj,
+then this attribute will not be present.
+
+@item new_children
+If new children were added to a dynamic varobj within the selected
+update range (as set by @code{-var-set-update-range}), then they will
+be listed in this attribute.
+@end table
+
+@subsubheading Example
+
+@smallexample
+(gdb)
+-var-assign var1 3
+^done,value="3"
+(gdb)
+-var-update --all-values var1
+^done,changelist=[@{name="var1",value="3",in_scope="true",
+type_changed="false"@}]
+(gdb)
+@end smallexample
+
@subheading The @code{-var-set-frozen} Command
@findex -var-set-frozen
@anchor{-var-set-frozen}
(gdb)
@end smallexample
+@subheading The @code{-var-set-update-range} command
+@findex -var-set-update-range
+@anchor{-var-set-update-range}
+
+@subsubheading Synopsis
+
+@smallexample
+ -var-set-update-range @var{name} @var{from} @var{to}
+@end smallexample
+
+Set the range of children to be returned by future invocations of
+@code{-var-update}.
+
+@var{from} and @var{to} indicate the range of children to report. If
+@var{from} or @var{to} is less than zero, the range is reset and all
+children will be reported. Otherwise, children starting at @var{from}
+(zero-based) and up to and excluding @var{to} will be reported.
+
+@subsubheading Example
+
+@smallexample
+(gdb)
+-var-set-update-range V 1 2
+^done
+@end smallexample
+
@subheading The @code{-var-set-visualizer} command
@findex -var-set-visualizer
@anchor{-var-set-visualizer}
@subheading Synopsis
@smallexample
--list-thread-groups [ --available ] [ @var{group} ]
+-list-thread-groups [ --available ] [ --recurse 1 ] [ @var{group} ... ]
@end smallexample
-When used without the @var{group} parameter, lists top-level thread
-groups that are being debugged. When used with the @var{group}
-parameter, the children of the specified group are listed. The
-children can be either threads, or other groups. At present,
-@value{GDBN} will not report both threads and groups as children at
-the same time, but it may change in future.
+Lists thread groups (@pxref{Thread groups}). When a single thread
+group is passed as the argument, lists the children of that group.
+When several thread group are passed, lists information about those
+thread groups. Without any parameters, lists information about all
+top-level thread groups.
+
+Normally, thread groups that are being debugged are reported.
+With the @samp{--available} option, @value{GDBN} reports thread groups
+available on the target.
+
+The output of this command may have either a @samp{threads} result or
+a @samp{groups} result. The @samp{thread} result has a list of tuples
+as value, with each tuple describing a thread (@pxref{GDB/MI Thread
+Information}). The @samp{groups} result has a list of tuples as value,
+each tuple describing a thread group. If top-level groups are
+requested (that is, no parameter is passed), or when several groups
+are passed, the output always has a @samp{groups} result. The format
+of the @samp{group} result is described below.
+
+To reduce the number of roundtrips it's possible to list thread groups
+together with their children, by passing the @samp{--recurse} option
+and the recursion depth. Presently, only recursion depth of 1 is
+permitted. If this option is present, then every reported thread group
+will also include its children, either as @samp{group} or
+@samp{threads} field.
+
+In general, any combination of option and parameters is permitted, with
+the following caveats:
+
+@itemize @bullet
+@item
+When a single thread group is passed, the output will typically
+be the @samp{threads} result. Because threads may not contain
+anything, the @samp{recurse} option will be ignored.
+
+@item
+When the @samp{--available} option is passed, limited information may
+be available. In particular, the list of threads of a process might
+be inaccessible. Further, specifying specific thread groups might
+not give any performance advantage over listing all thread groups.
+The frontend should assume that @samp{-list-thread-groups --available}
+is always an expensive operation and cache the results.
+
+@end itemize
-With the @samp{--available} option, instead of reporting groups that
-are been debugged, GDB will report all thread groups available on the
-target. Using the @samp{--available} option together with @var{group}
-is not allowed.
+The @samp{groups} result is a list of tuples, where each tuple may
+have the following fields:
+
+@table @code
+@item id
+Identifier of the thread group. This field is always present.
+The identifier is an opaque string; frontends should not try to
+convert it to an integer, even though it might look like one.
+
+@item type
+The type of the thread group. At present, only @samp{process} is a
+valid type.
+
+@item pid
+The target-specific process identifier. This field is only present
+for thread groups of type @samp{process} and only if the process exists.
+
+@item num_children
+The number of children this thread group has. This field may be
+absent for an available thread group.
+
+@item threads
+This field has a list of tuples as value, each tuple describing a
+thread. It may be present if the @samp{--recurse} option is
+specified, and it's actually possible to obtain the threads.
+
+@item cores
+This field is a list of integers, each identifying a core that one
+thread of the group is running on. This field may be absent if
+such information is not available.
+
+@item executable
+The name of the executable file that corresponds to this thread group.
+The field is only present for thread groups of type @samp{process},
+and only if there is a corresponding executable file.
+
+@end table
@subheading Example
@{id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
frame=@{level="0",addr="0x0804891f",func="foo",args=[@{name="i",value="10"@}],
file="/tmp/a.c",fullname="/tmp/a.c",line="158"@},state="running"@}]]
+-list-thread-groups --available
+^done,groups=[@{id="17",type="process",pid="yyy",num_children="2",cores=[1,2]@}]
+-list-thread-groups --available --recurse 1
+ ^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
+ threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@},
+ @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},..]
+-list-thread-groups --available --recurse 1 17 18
+^done,groups=[@{id="17", types="process",pid="yyy",num_children="2",cores=[1,2],
+ threads=[@{id="1",target-id="Thread 0xb7e14b90",cores=[1]@},
+ @{id="2",target-id="Thread 0xb7e14b90",cores=[2]@}]@},...]
+@end smallexample
+
+
+@subheading The @code{-add-inferior} Command
+@findex -add-inferior
+
+@subheading Synopsis
+
+@smallexample
+-add-inferior
+@end smallexample
+
+Creates a new inferior (@pxref{Inferiors and Programs}). The created
+inferior is not associated with any executable. Such association may
+be established with the @samp{-file-exec-and-symbols} command
+(@pxref{GDB/MI File Commands}). The command response has a single
+field, @samp{thread-group}, whose value is the identifier of the
+thread group corresponding to the new inferior.
+
+@subheading Example
+
+@smallexample
+@value{GDBP}
+-add-inferior
+^done,thread-group="i3"
@end smallexample
@subheading The @code{-interpreter-exec} Command
* Packets::
* Stop Reply Packets::
* General Query Packets::
-* Register Packet Format::
+* Architecture-Specific Protocol Details::
* Tracepoint Packets::
* Host I/O Packets::
* Interrupts::
* File-I/O Remote Protocol Extension::
* Library List Format::
* Memory Map Format::
+* Thread List Format::
@end menu
@node Overview
Don't use this packet. Use the @samp{Z} and @samp{z} packets instead
(@pxref{insert breakpoint or watchpoint packet}).
-@item bc
@cindex @samp{bc} packet
+@anchor{bc}
+@item bc
Backward continue. Execute the target system in reverse. No parameter.
@xref{Reverse Execution}, for more information.
Reply:
@xref{Stop Reply Packets}, for the reply specifications.
-@item bs
@cindex @samp{bs} packet
+@anchor{bs}
+@item bs
Backward single step. Execute one instruction in reverse. No parameter.
@xref{Reverse Execution}, for more information.
Step with signal @var{sig}. The signal @var{sig} should be two hex digits.
@item t
Stop.
-@item T @var{sig}
-Stop with signal @var{sig}. The signal @var{sig} should be two hex digits.
@end table
The optional argument @var{addr} normally associated with the
@samp{c}, @samp{C}, @samp{s}, and @samp{S} packets is
not supported in @samp{vCont}.
-The @samp{t} and @samp{T} actions are only relevant in non-stop mode
-(@pxref{Remote Non-Stop}) and may be ignored by the stub otherwise.
+The @samp{t} action is only relevant in non-stop mode
+(@pxref{Remote Non-Stop}) and may be ignored by the stub otherwise.
A stop reply should be generated for any affected thread not already stopped.
When a thread is stopped by means of a @samp{t} action,
the corresponding stop reply should indicate that the thread has stopped with
for an error
@end table
-@item z @var{type},@var{addr},@var{length}
-@itemx Z @var{type},@var{addr},@var{length}
+@item z @var{type},@var{addr},@var{kind}
+@itemx Z @var{type},@var{addr},@var{kind}
@anchor{insert breakpoint or watchpoint packet}
@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.
+watchpoint starting at address @var{address} of kind @var{kind}.
Each breakpoint and watchpoint packet @var{type} is documented
separately.
avoid potential problems with duplicate packets, the operations should
be implemented in an idempotent way.}
-@item z0,@var{addr},@var{length}
-@itemx Z0,@var{addr},@var{length}
+@item z0,@var{addr},@var{kind}
+@itemx Z0,@var{addr},@var{kind}
@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}.
+@var{addr} of type @var{kind}.
A memory breakpoint is implemented by replacing the instruction at
@var{addr} with a software breakpoint or trap instruction. 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).
+@var{kind} is target-specific and typically 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. Some
+architectures have additional meanings for @var{kind};
+see @ref{Architecture-Specific Protocol Details}.
@emph{Implementation note: It is possible for a target to copy or move
code that contains memory breakpoints (e.g., when implementing
for an error
@end table
-@item z1,@var{addr},@var{length}
-@itemx Z1,@var{addr},@var{length}
+@item z1,@var{addr},@var{kind}
+@itemx Z1,@var{addr},@var{kind}
@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}.
+address @var{addr}.
A hardware breakpoint is implemented using a mechanism that is not
-dependant on being able to modify the target's memory.
+dependant on being able to modify the target's memory. @var{kind}
+has the same meaning as in @samp{Z0} packets.
@emph{Implementation note: A hardware breakpoint is not affected by code
movement.}
for an error
@end table
-@item z2,@var{addr},@var{length}
-@itemx Z2,@var{addr},@var{length}
+@item z2,@var{addr},@var{kind}
+@itemx Z2,@var{addr},@var{kind}
@cindex @samp{z2} packet
@cindex @samp{Z2} packet
-Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint.
+Insert (@samp{Z2}) or remove (@samp{z2}) a write watchpoint at @var{addr}.
+@var{kind} is interpreted as the number of bytes to watch.
Reply:
@table @samp
for an error
@end table
-@item z3,@var{addr},@var{length}
-@itemx Z3,@var{addr},@var{length}
+@item z3,@var{addr},@var{kind}
+@itemx Z3,@var{addr},@var{kind}
@cindex @samp{z3} packet
@cindex @samp{Z3} packet
-Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint.
+Insert (@samp{Z3}) or remove (@samp{z3}) a read watchpoint at @var{addr}.
+@var{kind} is interpreted as the number of bytes to watch.
Reply:
@table @samp
for an error
@end table
-@item z4,@var{addr},@var{length}
-@itemx Z4,@var{addr},@var{length}
+@item z4,@var{addr},@var{kind}
+@itemx Z4,@var{addr},@var{kind}
@cindex @samp{z4} packet
@cindex @samp{Z4} packet
-Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint.
+Insert (@samp{Z4}) or remove (@samp{z4}) an access watchpoint at @var{addr}.
+@var{kind} is interpreted as the number of bytes to watch.
Reply:
@table @samp
If @var{n} is @samp{thread}, then @var{r} is the @var{thread-id} of
the stopped thread, as specified in @ref{thread-id syntax}.
+@item
+If @var{n} is @samp{core}, then @var{r} is the hexadecimal number of
+the core on which the stop event was detected.
+
@item
If @var{n} is a recognized @dfn{stop reason}, it describes a more
specific event that stopped the target. The currently defined stop
beginning when executing backward) of the log. The value of @var{r}
will be either @samp{begin} or @samp{end}. @xref{Reverse Execution},
for more information.
-
-
@end table
@item W @var{AA}
@tab @samp{-}
@tab Yes
+@item @samp{qXfer:threads:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+
@item @samp{QNonStop}
@tab No
@tab @samp{-}
@tab @samp{-}
@tab No
+@item @samp{ReverseContinue}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{ReverseStep}
+@tab No
+@tab @samp{-}
+@tab No
+
@end multitable
These are the currently defined stub features, in more detail:
The remote stub understands the @samp{qXfer:siginfo:write} packet
(@pxref{qXfer siginfo write}).
+@item qXfer:threads:read
+The remote stub understands the @samp{qXfer:threads:read} packet
+(@pxref{qXfer threads read}).
+
@item QNonStop
The remote stub understands the @samp{QNonStop} packet
(@pxref{QNonStop}).
The remote stub accepts and implements conditional expressions defined
for tracepoints (@pxref{Tracepoint Conditions}).
+@item ReverseContinue
+The remote stub accepts and implements the reverse continue packet
+(@pxref{bc}).
+
+@item ReverseStep
+The remote stub accepts and implements the reverse step packet
+(@pxref{bs}).
+
@end table
@item qSymbol::
(if available), until the target ceases to request them.
@end table
-@item QTDP
+@item qTBuffer
+@item QTBuffer
+@item QTDisconnected
+@itemx QTDP
+@itemx QTDV
+@itemx qTfP
+@itemx qTfV
@itemx QTFrame
@xref{Tracepoint Packets}.
conventions above. Please don't use this packet as a model for new
packets.)
-@item QTStart
+@item QTSave
+@item qTsP
+@item qTsV
+@itemx QTStart
@itemx QTStop
@itemx QTinit
@itemx QTro
@itemx qTStatus
+@itemx qTV
@xref{Tracepoint Packets}.
@item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length}
by supplying an appropriate @samp{qSupported} response
(@pxref{qSupported}).
+@item qXfer:threads:read::@var{offset},@var{length}
+@anchor{qXfer threads read}
+Access the list of threads on target. @xref{Thread List Format}. The
+annex part of the generic @samp{qXfer} packet must be empty
+(@pxref{qXfer read}).
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
@item qXfer:osdata:read::@var{offset},@var{length}
@anchor{qXfer osdata read}
Access the target's @dfn{operating system information}.
@end table
-@node Register Packet Format
-@section Register Packet Format
+@node Architecture-Specific Protocol Details
+@section Architecture-Specific Protocol Details
+
+This section describes how the remote protocol is applied to specific
+target architectures. Also see @ref{Standard Target Features}, for
+details of XML target descriptions for each architecture.
+
+@subsection ARM
+
+@subsubsection Breakpoint Kinds
+
+These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets.
+
+@table @r
+
+@item 2
+16-bit Thumb mode breakpoint.
+
+@item 3
+32-bit Thumb mode (Thumb-2) breakpoint.
+
+@item 4
+32-bit ARM mode breakpoint.
+
+@end table
+
+@subsection MIPS
+
+@subsubsection Register Packet Format
The following @code{g}/@code{G} packets have previously been defined.
In the below, some thirty-two bit registers are transferred as
@table @samp
-@item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:X@var{len},@var{bytes}]@r{[}-@r{]}
+@item QTDP:@var{n}:@var{addr}:@var{ena}:@var{step}:@var{pass}[:F@var{flen}][:X@var{len},@var{bytes}]@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 an @samp{X} is present,
-it introduces a tracepoint condition, which consists of a hexadecimal
-length, followed by a comma and hex-encoded bytes, in a manner similar
-to action encodings as described below. If the trailing @samp{-} is
-present, further @samp{QTDP} packets will follow to specify this
-tracepoint's actions.
+count, and @var{pass} is its pass count. If an @samp{F} is present,
+then the tracepoint is to be a fast tracepoint, and the @var{flen} is
+the number of bytes that the target should copy elsewhere to make room
+for the tracepoint. If an @samp{X} is present, it introduces a
+tracepoint condition, which consists of a hexadecimal length, followed
+by a comma and hex-encoded bytes, in a manner similar to action
+encodings as described below. If the trailing @samp{-} is present,
+further @samp{QTDP} packets will follow to specify this tracepoint's
+actions.
Replies:
@table @samp
The packet was not recognized.
@end table
+@item QTDV:@var{n}:@var{value}
+@cindex define trace state variable, remote request
+@cindex @samp{QTDV} packet
+Create a new trace state variable, number @var{n}, with an initial
+value of @var{value}, which is a 64-bit signed integer. Both @var{n}
+and @var{value} are encoded as hexadecimal values. @value{GDBN} has
+the option of not using this packet for initial values of zero; the
+target should simply create the trace state variables as they are
+mentioned in expressions.
+
@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
@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 hexadecimal
+and @var{end} (inclusive); @var{start} and @var{end} are hexadecimal
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.
+frame @emph{outside} the given range of addresses (exclusive).
@item QTStart
Begin the tracepoint experiment. Begin collecting data from tracepoint
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 QTDisconnected:@var{value}
+Set the choice to what to do with the tracing run when @value{GDBN}
+disconnects from the target. A @var{value} of 1 directs the target to
+continue the tracing run, while 0 tells the target to stop tracing if
+@value{GDBN} is no longer in the picture.
+
@item qTStatus
Ask the stub if there is a trace experiment running right now.
-Replies:
+The reply has the form:
+
@table @samp
-@item T0
-There is no trace experiment running.
-@item T1
-There is a trace experiment running.
+
+@item T@var{running}@r{[};@var{field}@r{]}@dots{}
+@var{running} is a single digit @code{1} if the trace is presently
+running, or @code{0} if not. It is followed by semicolon-separated
+optional fields that an agent may use to report additional status.
+
+@end table
+
+If the trace is not running, the agent may report any of several
+explanations as one of the optional fields:
+
+@table @samp
+
+@item tnotrun:0
+No trace has been run yet.
+
+@item tstop:0
+The trace was stopped by a user-originated stop command.
+
+@item tfull:0
+The trace stopped because the trace buffer filled up.
+
+@item tdisconnected:0
+The trace stopped because @value{GDBN} disconnected from the target.
+
+@item tpasscount:@var{tpnum}
+The trace stopped because tracepoint @var{tpnum} exceeded its pass count.
+
+@item tunknown:0
+The trace stopped for some other reason.
+
@end table
+Additional optional fields supply statistical information. Although
+not required, they are extremely useful for users monitoring the
+progress of a trace run. If a trace has stopped, and these numbers
+are reported, they must reflect the state of the just-stopped trace.
+
+@table @samp
+
+@item tframes:@var{n}
+The number of trace frames in the buffer.
+
+@item tcreated:@var{n}
+The total number of trace frames created during the run. This may
+be larger than the trace frame count, if the buffer is circular.
+
+@item tsize:@var{n}
+The total size of the trace buffer, in bytes.
+
+@item tfree:@var{n}
+The number of bytes still unused in the buffer.
+
@end table
+@item qTV:@var{var}
+@cindex trace state variable value, remote request
+@cindex @samp{qTV} packet
+Ask the stub for the value of the trace state variable number @var{var}.
+
+Replies:
+@table @samp
+@item V@var{value}
+The value of the variable is @var{value}. This will be the current
+value of the variable if the user is examining a running target, or a
+saved value if the variable was collected in the trace frame that the
+user is looking at. Note that multiple requests may result in
+different reply values, such as when requesting values while the
+program is running.
+
+@item U
+The value of the variable is unknown. This would occur, for example,
+if the user is examining a trace frame in which the requested variable
+was not collected.
+@end table
+
+@item qTfP
+@itemx qTsP
+These packets request data about tracepoints that are being used by
+the target. @value{GDBN} sends @code{qTfP} to get the first piece
+of data, and multiple @code{qTsP} to get additional pieces. Replies
+to these packets generally take the form of the @code{QTDP} packets
+that define tracepoints. (FIXME add detailed syntax)
+
+@item qTfV
+@itemx qTsV
+These packets request data about trace state variables that are on the
+target. @value{GDBN} sends @code{qTfV} to get the first vari of data,
+and multiple @code{qTsV} to get additional variables. Replies to
+these packets follow the syntax of the @code{QTDV} packets that define
+trace state variables.
+
+@item QTSave:@var{filename}
+This packet directs the target to save trace data to the file name
+@var{filename} in the target's filesystem. @var{filename} is encoded
+as a hex string; the interpretation of the file name (relative vs
+absolute, wild cards, etc) is up to the target.
+
+@item qTBuffer:@var{offset},@var{len}
+Return up to @var{len} bytes of the current contents of trace buffer,
+starting at @var{offset}. The trace buffer is treated as if it were
+a contiguous collection of traceframes, as per the trace file format.
+The reply consists as many hex-encoded bytes as the target can deliver
+in a packet; it is not an error to return fewer than were asked for.
+A reply consisting of just @code{l} indicates that no bytes are
+available.
+
+@item QTBuffer:circular:@var{value}
+This packet directs the target to use a circular trace buffer if
+@var{value} is 1, or a linear buffer if the value is 0.
+
+@end table
@node Host I/O Packets
@section Host I/O Packets
@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}).
+attempt to interrupt it by sending a @samp{Ctrl-C}, @code{BREAK} or
+a @code{BREAK} followed by @code{g},
+control of which is specified via @value{GDBN}'s @samp{interrupt-sequence}.
The precise meaning of @code{BREAK} is defined by the transport
mechanism and may, in fact, be undefined. @value{GDBN} does not
(@pxref{X packet}), used for binary downloads, may include an unescaped
@code{0x03} as part of its packet.
+@code{BREAK} followed by @code{g} is also known as Magic SysRq g.
+When Linux kernel receives this sequence from serial port,
+it stops execution and connects to gdb.
+
Stubs are not required to recognize these interrupt mechanisms and the
precise meaning associated with receipt of the interrupt is
implementation defined. If the target supports debugging of multiple
<!ATTLIST property name CDATA #REQUIRED>
@end smallexample
+@node Thread List Format
+@section Thread List Format
+@cindex thread list format
+
+To efficiently update the list of threads and their attributes,
+@value{GDBN} issues the @samp{qXfer:threads:read} packet
+(@pxref{qXfer threads read}) and obtains the XML document with
+the following structure:
+
+@smallexample
+<?xml version="1.0"?>
+<threads>
+ <thread id="id" core="0">
+ ... description ...
+ </thread>
+</threads>
+@end smallexample
+
+Each @samp{thread} element must have the @samp{id} attribute that
+identifies the thread (@pxref{thread-id syntax}). The
+@samp{core} attribute, if present, specifies which processor core
+the thread was last executing on. The content of the of @samp{thread}
+element is interpreted as human-readable auxilliary information.
+
@include agentexpr.texi
+@node Trace File Format
+@appendix Trace File Format
+@cindex trace file format
+
+The trace file comes in three parts: a header, a textual description
+section, and a trace frame section with binary data.
+
+The header has the form @code{\x7fTRACE0\n}. The first byte is
+@code{0x7f} so as to indicate that the file contains binary data,
+while the @code{0} is a version number that may have different values
+in the future.
+
+The description section consists of multiple lines of @sc{ascii} text
+separated by newline characters (@code{0xa}). The lines may include a
+variety of optional descriptive or context-setting information, such
+as tracepoint definitions or register set size. @value{GDBN} will
+ignore any line that it does not recognize. An empty line marks the end
+of this section.
+
+@c FIXME add some specific types of data
+
+The trace frame section consists of a number of consecutive frames.
+Each frame begins with a two-byte tracepoint number, followed by a
+four-byte size giving the amount of data in the frame. The data in
+the frame consists of a number of blocks, each introduced by a
+character indicating its type (at least register, memory, and trace
+state variable). The data in this section is raw binary, not a
+hexadecimal or other encoding; its endianness matches the target's
+endianness.
+
+@c FIXME bi-arch may require endianness/arch info in description section
+
+@table @code
+@item R @var{bytes}
+Register block. The number and ordering of bytes matches that of a
+@code{g} packet in the remote protocol. Note that these are the
+actual bytes, in target order and @value{GDBN} register order, not a
+hexadecimal encoding.
+
+@item M @var{address} @var{length} @var{bytes}...
+Memory block. This is a contiguous block of memory, at the 8-byte
+address @var{address}, with a 2-byte length @var{length}, followed by
+@var{length} bytes.
+
+@item V @var{number} @var{value}
+Trace state variable block. This records the 8-byte signed value
+@var{value} of trace state variable numbered @var{number}.
+
+@end table
+
+Future enhancements of the trace file format may include additional types
+of blocks.
+
@node Target Descriptions
@appendix Target Descriptions
@cindex target descriptions
</union>
@end smallexample
+@cindex <struct>
+If a register's value is composed from several separate values, define
+it with a structure type. There are two forms of the @samp{<struct>}
+element; a @samp{<struct>} element must either contain only bitfields
+or contain no bitfields. If the structure contains only bitfields,
+its total size in bytes must be specified, each bitfield must have an
+explicit start and end, and bitfields are automatically assigned an
+integer type. The field's @var{start} should be less than or
+equal to its @var{end}, and zero represents the least significant bit.
+
+@smallexample
+<struct id="@var{id}" size="@var{size}">
+ <field name="@var{name}" start="@var{start}" end="@var{end}"/>
+ @dots{}
+</struct>
+@end smallexample
+
+If the structure contains no bitfields, then each field has an
+explicit type, and no implicit padding is added.
+
+@smallexample
+<struct id="@var{id}">
+ <field name="@var{name}" type="@var{type}"/>
+ @dots{}
+</struct>
+@end smallexample
+
+@cindex <flags>
+If a register's value is a series of single-bit flags, define it with
+a flags type. The @samp{<flags>} element has an explicit @var{size}
+and contains one or more @samp{<field>} elements. Each field has a
+@var{name}, a @var{start}, and an @var{end}. Only single-bit flags
+are supported.
+
+@smallexample
+<flags id="@var{id}" size="@var{size}">
+ <field name="@var{name}" start="@var{start}" end="@var{end}"/>
+ @dots{}
+</flags>
+@end smallexample
+
@subsection Registers
@cindex <reg>
@item arm_fpa_ext
The 12-byte extended precision format used by ARM FPA registers.
+@item i387_ext
+The 10-byte extended precision format used by x87 registers.
+
+@item i386_eflags
+32bit @sc{eflags} register used by x86.
+
+@item i386_mxcsr
+32bit @sc{mxcsr} register used by x86.
+
@end table
@node Standard Target Features
@menu
* ARM Features::
+* i386 Features::
* MIPS Features::
* M68K Features::
* PowerPC Features::
If this feature is present, @samp{org.gnu.gdb.arm.vfp} must also
be present and include 32 double-precision registers.
+@node i386 Features
+@subsection i386 Features
+@cindex target descriptions, i386 features
+
+The @samp{org.gnu.gdb.i386.core} feature is required for i386/amd64
+targets. It should describe the following registers:
+
+@itemize @minus
+@item
+@samp{eax} through @samp{edi} plus @samp{eip} for i386
+@item
+@samp{rax} through @samp{r15} plus @samp{rip} for amd64
+@item
+@samp{eflags}, @samp{cs}, @samp{ss}, @samp{ds}, @samp{es},
+@samp{fs}, @samp{gs}
+@item
+@samp{st0} through @samp{st7}
+@item
+@samp{fctrl}, @samp{fstat}, @samp{ftag}, @samp{fiseg}, @samp{fioff},
+@samp{foseg}, @samp{fooff} and @samp{fop}
+@end itemize
+
+The register sets may be different, depending on the target.
+
+The @samp{org.gnu.gdb.i386.sse} feature is required. It should
+describe registers:
+
+@itemize @minus
+@item
+@samp{xmm0} through @samp{xmm7} for i386
+@item
+@samp{xmm0} through @samp{xmm15} for amd64
+@item
+@samp{mxcsr}
+@end itemize
+
+The @samp{org.gnu.gdb.i386.linux} feature is optional. It should
+describe a single register, @samp{orig_eax}.
+
@node MIPS Features
@subsection MIPS Features
@cindex target descriptions, MIPS features
<column name="pid">1</column>
<column name="user">root</column>
<column name="command">/sbin/init</column>
+ <column name="cores">1,2,3</column>
</item>
</osdata>
@end smallexample
Each item should include a column whose name is @samp{pid}. The value
of that column should identify the process on the target. The
@samp{user} and @samp{command} columns are optional, and will be
-displayed by @value{GDBN}. Target may provide additional columns,
+displayed by @value{GDBN}. The @samp{cores} column, if present,
+should contain a comma-separated list of cores that this process
+is running on. Target may provide additional columns,
which @value{GDBN} currently ignores.
@include gpl.texi
projects / deliverable / binutils-gdb.git / blobdiff