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_data_disassemble
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'GDB-Commands-MI'
!
!GDBMI_data_disassemble 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 `-data-disassemble' Command
-------------------------------
Synopsis
........
-data-disassemble
[ -s START-ADDR -e END-ADDR ]
| [ -f FILENAME -l LINENUM [ -n LINES ] ]
-- MODE
Where:
`START-ADDR'
is the beginning address (or `$pc')
`END-ADDR'
is the end address
`FILENAME'
is the name of the file to disassemble
`LINENUM'
is the line number to disassemble around
`LINES'
is the number of disassembly lines to be produced. If it is -1,
the whole function will be disassembled, in case no END-ADDR is
specified. If END-ADDR is specified as a non-zero value, and
LINES is lower than the number of disassembly lines between
START-ADDR and END-ADDR, only LINES lines are displayed; if LINES
is higher than the number of lines between START-ADDR and
END-ADDR, only the lines up to END-ADDR are displayed.
`MODE'
is either 0 (meaning only disassembly), 1 (meaning mixed source and
disassembly), 2 (meaning disassembly with raw opcodes), or 3
(meaning mixed source and disassembly with raw opcodes).
Result
......
The result of the `-data-disassemble' command will be a list named
`asm_insns', the contents of this list depend on the MODE used with the
`-data-disassemble' command.
For modes 0 and 2 the `asm_insns' list contains tuples with the
following fields:
`address'
The address at which this instruction was disassembled.
`func-name'
The name of the function this instruction is within.
`offset'
The decimal offset in bytes from the start of `func-name'.
`inst'
The text disassembly for this `address'.
`opcodes'
This field is only present for mode 2. This contains the raw
opcode bytes for the `inst' field.
For modes 1 and 3 the `asm_insns' list contains tuples named
`src_and_asm_line', each of which has the following fields:
`line'
The line number within `file'.
`file'
The file name from the compilation unit. This might be an absolute
file name or a relative file name depending on the compile command
used.
`fullname'
Absolute file name of `file'. It is converted to a canonical form
using the source file search path (*note Specifying Source
Directories: Source Path.) and after resolving all the symbolic
links.
If the source file is not found this field will contain the path as
present in the debug information.
`line_asm_insn'
This is a list of tuples containing the disassembly for `line' in
`file'. The fields of each tuple are the same as for
`-data-disassemble' in MODE 0 and 2, so `address', `func-name',
`offset', `inst', and optionally `opcodes'.
Note that whatever included in the `inst' field, is not manipulated
directly by GDB/MI, i.e., it is not possible to adjust its format.
{No value for `GDBN'} Command
.............................
The corresponding {No value for `GDBN'} command is `disassemble'.
Example
.......
Disassemble from the current value of `$pc' to `$pc + 20':
(gdb)
-data-disassemble -s $pc -e '$pc + 20' -- 0
^done,
asm_insns=[
{address='0x000107c0',func-name='main',offset='4',
inst='mov 2, %o0'},
{address='0x000107c4',func-name='main',offset='8',
inst='sethi %hi(0x11800), %o2'},
{address='0x000107c8',func-name='main',offset='12',
inst='or %o2, 0x140, %o1\t!! 0x11940 <_lib_version+8>'},
{address='0x000107cc',func-name='main',offset='16',
inst='sethi %hi(0x11800), %o2'},
{address='0x000107d0',func-name='main',offset='20',
inst='or %o2, 0x168, %o4\t!! 0x11968 <_lib_version+48>'}]
(gdb)
Disassemble the whole `main' function. Line 32 is part of `main'.
-data-disassemble -f basics.c -l 32 -- 0
^done,asm_insns=[
{address='0x000107bc',func-name='main',offset='0',
inst='save %sp, -112, %sp'},
{address='0x000107c0',func-name='main',offset='4',
inst='mov 2, %o0'},
{address='0x000107c4',func-name='main',offset='8',
inst='sethi %hi(0x11800), %o2'},
[...]
{address='0x0001081c',func-name='main',offset='96',inst='ret '},
{address='0x00010820',func-name='main',offset='100',inst='restore '}]
(gdb)
Disassemble 3 instructions from the start of `main':
(gdb)
-data-disassemble -f basics.c -l 32 -n 3 -- 0
^done,asm_insns=[
{address='0x000107bc',func-name='main',offset='0',
inst='save %sp, -112, %sp'},
{address='0x000107c0',func-name='main',offset='4',
inst='mov 2, %o0'},
{address='0x000107c4',func-name='main',offset='8',
inst='sethi %hi(0x11800), %o2'}]
(gdb)
Disassemble 3 instructions from the start of `main' in mixed mode:
(gdb)
-data-disassemble -f basics.c -l 32 -n 3 -- 1
^done,asm_insns=[
src_and_asm_line={line='31',
file='../../../src/gdb/testsuite/gdb.mi/basics.c',
fullname='/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c',
line_asm_insn=[{address='0x000107bc',
func-name='main',offset='0',inst='save %sp, -112, %sp'}]},
src_and_asm_line={line='32',
file='../../../src/gdb/testsuite/gdb.mi/basics.c',
fullname='/absolute/path/to/src/gdb/testsuite/gdb.mi/basics.c',
line_asm_insn=[{address='0x000107c0',
func-name='main',offset='4',inst='mov 2, %o0'},
{address='0x000107c4',func-name='main',offset='8',
inst='sethi %hi(0x11800), %o2'}]}]
(gdb)
"
! !
!GDBMI_data_disassemble methodsFor:'accessing'!
operation
^ 'data-disassemble'
! !
!GDBMI_data_disassemble methodsFor:'accessing-descriptors'!
resultDescription
^ (super resultDescription)
define:#'asm_insns'
as:Array of:GDBInstructionsAndSourceLine whenTaggedBy: 'src_and_asm_line'
or:GDBInstruction whenTaggedBy: nil;
yourself
"
Magritte::MADescriptionBuilder default flush.
GDBMI_data_disassemble new resultDescription"
"Created: / 22-06-2018 / 10:24:16 / Jan Vrany <jan.vrany@fit.cvut.cz>"
"Modified: / 03-07-2018 / 17:17:49 / Jan Vrany <jan.vrany@fit.cvut.cz>"
! !