27.20 Miscellaneous gdb/mi Commands

The -gdb-exit Command

Synopsis
      -gdb-exit

Exit gdb immediately.

gdb Command

Approximately corresponds to quit.

Example
     (gdb)
     -gdb-exit
     ^exit

The -gdb-set Command

Synopsis
      -gdb-set

Set an internal gdb variable.

gdb Command

The corresponding gdb command is set.

Example
     (gdb)
     -gdb-set $foo=3
     ^done
     (gdb)

The -gdb-show Command

Synopsis
      -gdb-show

Show the current value of a gdb variable.

gdb Command

The corresponding gdb command is show.

Example
     (gdb)
     -gdb-show annotate
     ^done,value="0"
     (gdb)

The -gdb-version Command

Synopsis
      -gdb-version

Show version information for gdb. Used mostly in testing.

gdb Command

The gdb equivalent is show version. gdb by default shows this information when you start an interactive session.

Example
     (gdb)
     -gdb-version
     ~GNU gdb 5.2.1
     ~Copyright 2000 Free Software Foundation, Inc.
     ~GDB is free software, covered by the GNU General Public License, and
     ~you are welcome to change it and/or distribute copies of it under
     ~ certain conditions.
     ~Type "show copying" to see the conditions.
     ~There is absolutely no warranty for GDB.  Type "show warranty" for
     ~ details.
     ~This GDB was configured as
      "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi".
     ^done
     (gdb)

The -list-features Command

Returns a list of particular features of the MI protocol that this version of gdb implements. A feature can be a command, or a new field in an output of some command, or even an important bugfix. While a frontend can sometimes detect presence of a feature at runtime, it is easier to perform detection at debugger startup.

The command returns a list of strings, with each string naming an available feature. Each returned string is just a name, it does not have any internal structure. The list of possible feature names is given below.

Example output:

     (gdb) -list-features
     ^done,result=["feature1","feature2"]

The current list of features is:

frozen-varobjs
Indicates presence of the -var-set-frozen command, as well as possible presense of the frozen field in the output of -varobj-create.
pending-breakpoints
Indicates presence of the -f option to the -break-insert command.
python
Indicates presence of Python scripting support, Python-based pretty-printing commands, and possible presence of the display_hint field in the output of -var-list-children
thread-info
Indicates presence of the -thread-info command.

The -list-target-features Command

Returns a list of particular features that are supported by the target. Those features affect the permitted MI commands, but unlike the features reported by the -list-features command, the features depend on which target GDB is using at the moment. Whenever a target can change, due to commands such as -target-select, -target-attach or -exec-run, the list of target features may change, and the frontend should obtain it again. Example output:

     (gdb) -list-features
     ^done,result=["async"]

The current list of features is:

async
Indicates that the target is capable of asynchronous command execution, which means that gdb will accept further commands while the target is running.
reverse
Indicates that the target is capable of reverse execution. See Reverse Execution, for more information.

The -list-thread-groups Command

Synopsis

     -list-thread-groups [ --available ] [ --recurse 1 ] [ group ... ]

Lists thread groups (see 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 --available option, gdb reports thread groups available on the target.

The output of this command may have either a threads result or a groups result. The thread result has a list of tuples as value, with each tuple describing a thread (see GDB/MI Thread Information). The 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 groups result. The format of the 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 --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 group or threads field.

In general, any combination of option and parameters is permitted, with the following caveats:

The groups result is a list of tuples, where each tuple may have the following fields:

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.
type
The type of the thread group. At present, only process is a valid type.
pid
The target-specific process identifier. This field is only present for thread groups of type process and only if the process exists.
num_children
The number of children this thread group has. This field may be absent for an available thread group.
threads
This field has a list of tuples as value, each tuple describing a thread. It may be present if the --recurse option is specified, and it's actually possible to obtain the threads.
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.
executable
The name of the executable file that corresponds to this thread group. The field is only present for thread groups of type process, and only if there is a corresponding executable file.

Example

     gdb
     -list-thread-groups
     ^done,groups=[{id="17",type="process",pid="yyy",num_children="2"}]
     -list-thread-groups 17
     ^done,threads=[{id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
        frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",args=[]},state="running"},
     {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]}]},...]

The -add-inferior Command

Synopsis

     -add-inferior

Creates a new inferior (see Inferiors and Programs). The created inferior is not associated with any executable. Such association may be established with the -file-exec-and-symbols command (see GDB/MI File Commands). The command response has a single field, thread-group, whose value is the identifier of the thread group corresponding to the new inferior.

Example

     gdb
     -add-inferior
     ^done,thread-group="i3"

The -interpreter-exec Command

Synopsis

     -interpreter-exec interpreter command

Execute the specified command in the given interpreter.

gdb Command

The corresponding gdb command is interpreter-exec.

Example

     (gdb)
     -interpreter-exec console "break main"
     &"During symbol reading, couldn't parse type; debugger out of date?.\n"
     &"During symbol reading, bad structure-type format.\n"
     ~"Breakpoint 1 at 0x8074fc6: file ../../src/gdb/main.c, line 743.\n"
     ^done
     (gdb)

The -inferior-tty-set Command

Synopsis

     -inferior-tty-set /dev/pts/1

Set terminal for future runs of the program being debugged.

gdb Command

The corresponding gdb command is set inferior-tty /dev/pts/1.

Example

     (gdb)
     -inferior-tty-set /dev/pts/1
     ^done
     (gdb)

The -inferior-tty-show Command

Synopsis

     -inferior-tty-show

Show terminal for future runs of program being debugged.

gdb Command

The corresponding gdb command is show inferior-tty.

Example

     (gdb)
     -inferior-tty-set /dev/pts/1
     ^done
     (gdb)
     -inferior-tty-show
     ^done,inferior_tty_terminal="/dev/pts/1"
     (gdb)

The -enable-timings Command

Synopsis

     -enable-timings [yes | no]

Toggle the printing of the wallclock, user and system times for an MI command as a field in its output. This command is to help frontend developers optimize the performance of their code. No argument is equivalent to yes.

gdb Command

No equivalent.

Example

     (gdb)
     -enable-timings
     ^done
     (gdb)
     -break-insert main
     ^done,bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
     addr="0x080484ed",func="main",file="myprog.c",
     fullname="/home/nickrob/myprog.c",line="73",times="0"},
     time={wallclock="0.05185",user="0.00800",system="0.00000"}
     (gdb)
     -enable-timings no
     ^done
     (gdb)
     -exec-run
     ^running
     (gdb)
     *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",thread-id="0",
     frame={addr="0x080484ed",func="main",args=[{name="argc",value="1"},
     {name="argv",value="0xbfb60364"}],file="myprog.c",
     fullname="/home/nickrob/myprog.c",line="73"}
     (gdb)