Emit and handle (custom) `-register-changed` notification
This commit adds new (custom) asynchronous notification about register value
being changed. Standard GDB does not notify MI clients about register value
being changed when debugging (for example, by CLI command `set $rax = 1` or
via Python's `Value.assign()`).
This caused libgdb's register value cache being out of sync. In the past,
this was partially worked around by manually emiting the notification on
`GDBRegisterWithValue` APIs, but this did not (and could not) handle the case
register was changed from GDB command line.
To solve this problem, this commit installs a custom Python event handler
that emits new GDB/MI notification - `-register-changed` - whenever a register
changes after debugee is stopped. This has been enabled by upstream GDB commit
4825fd "gdb/python: implement support for sending custom MI async notifications"
On libgdbs side, complete inferior state is invalidated. In theory, one could
carefully invalidate only the changed `GDBRegisterWithValue` but in certain cases
this could also change the backtrace (for example, if one updates stack pointer)
or position in code. So it seems safer to just invalidate everything.
"
jv:libgdbs - GNU Debugger Interface Library
Copyright (C) 2015-now Jan Vrany
Copyright (C) 2022-2023 LabWare
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the 'Software'), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"
"{ Package: 'jv:libgdbs' }"
"{ NameSpace: Smalltalk }"
GDBMICommand subclass:#GDBMI_list_features
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'GDB-Commands-MI'
!
!GDBMI_list_features class methodsFor:'documentation'!
copyright
"
jv:libgdbs - GNU Debugger Interface Library
Copyright (C) 2015-now Jan Vrany
Copyright (C) 2022-2023 LabWare
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the 'Software'), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"
!
documentation
"
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 presense of the `frozen' 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
(*note 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 (*note GDB/MI Result Records::).
`exec-run-start-option'
Indicates that the `-exec-run' command supports the `--start'
option (*note GDB/MI Program Execution::).
"
! !
!GDBMI_list_features methodsFor:'accessing'!
operation
^ 'list-features'
! !