Gdb/GDB 002fMI-Support-Commands
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27.23 GDB/MI Support Commands
Since new commands and features get regularly added to GDB/MI, some commands are available to help front-ends query the debugger about support for these capabilities. Similarly, it is also possible to query GDB about target support of certain features.
The -info-gdb-mi-command
Command
Synopsis
-info-gdb-mi-command cmd_name
Query support for the GDB/MI command named cmd_name
.
Note that the dash (-
) starting all GDB/MI commands
is technically not part of the command name (see GDB/MI Input Syntax), and thus should be omitted in cmd_name
. However,
for ease of use, this command also accepts the form with the leading
dash.
GDB Command
There is no corresponding GDB command.
Result
The result is a tuple. There is currently only one field:
- ‘
exists
’ - This field is equal to
"true"
if the GDB/MI command exists,"false"
otherwise.
Example
Here is an example where the GDB/MI command does not exist:
-info-gdb-mi-command unsupported-command ^done,command={exists="false"}
And here is an example where the GDB/MI command is known to the debugger:
-info-gdb-mi-command symbol-list-lines ^done,command={exists="true"}
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 support for the
-var-set-frozen
command, as well as possible presence of thefrozen
field in the output of-varobj-create
. - ‘
pending-breakpoints
’ - Indicates support for the
-f
option to the-break-insert
command. - ‘
python
’ - Indicates 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 support for the
-thread-info
command. - ‘
data-read-memory-bytes
’ - Indicates support for the
-data-read-memory-bytes
and the-data-write-memory-bytes
commands. - ‘
breakpoint-notifications
’ - Indicates that changes to breakpoints and breakpoints created via the CLI will be announced via async records.
- ‘
ada-task-info
’ - Indicates support for the
-ada-task-info
command. - ‘
language-option
’ - Indicates that all GDB/MI commands accept the
--language
option (see Context management). - ‘
info-gdb-mi-command
’ - Indicates support for the
-info-gdb-mi-command
command. - ‘
undefined-command-error-code
’ - Indicates support for the "undefined-command" error code in error result records, produced when trying to execute an undefined GDB/MI command (see GDB/MI Result Records).
- ‘
exec-run-start-option
’ - Indicates that the
-exec-run
command supports the--start
option (see GDB/MI Program Execution). - ‘
data-disassemble-a-option
’ - Indicates that the
-data-disassemble
command supports the-a
option (see GDB/MI Data Manipulation).
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-target-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.
Next: GDB/MI Miscellaneous Commands, Previous: GDB/MI Ada Exceptions Commands, Up: GDB/MI [Contents][Index]