gdb: GDB/MI Stack Manipulation
27.14 GDB/MI Stack Manipulation Commands
========================================
The '-enable-frame-filters' Command
-----------------------------------
-enable-frame-filters
GDB allows Python-based frame filters to affect the output of the MI
commands relating to stack traces. As there is 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 GDB, this
command will still succeed (and do nothing).
The '-stack-info-frame' Command
-------------------------------
Synopsis
........
-stack-info-frame
Get info on the selected frame.
GDB Command
...........
The corresponding GDB command is 'info frame' or 'frame' (without
arguments).
Example
.......
(gdb)
-stack-info-frame
^done,frame={level="1",addr="0x0001076c",func="callee3",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17",
arch="i386:x86_64"}
(gdb)
The '-stack-info-depth' Command
-------------------------------
Synopsis
........
-stack-info-depth [ MAX-DEPTH ]
Return the depth of the stack. If the integer argument MAX-DEPTH is
specified, do not count beyond MAX-DEPTH frames.
GDB Command
...........
There's no equivalent GDB command.
Example
.......
For a stack with frame levels 0 through 11:
(gdb)
-stack-info-depth
^done,depth="12"
(gdb)
-stack-info-depth 4
^done,depth="4"
(gdb)
-stack-info-depth 12
^done,depth="12"
(gdb)
-stack-info-depth 11
^done,depth="11"
(gdb)
-stack-info-depth 13
^done,depth="12"
(gdb)
The '-stack-list-arguments' Command
-----------------------------------
Synopsis
........
-stack-list-arguments [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES
[ LOW-FRAME HIGH-FRAME ]
Display a list of the arguments for the frames between LOW-FRAME and
HIGH-FRAME (inclusive). If LOW-FRAME and HIGH-FRAME are not provided,
list the arguments for the whole call stack. If the two arguments are
equal, show the single frame at the corresponding level. It is an error
if LOW-FRAME is larger than the actual number of frames. On the other
hand, HIGH-FRAME may be larger than the actual number of frames, in
which case only existing frames will be returned.
If PRINT-VALUES is 0 or '--no-values', print only the names of the
variables; if it is 1 or '--all-values', print also their values; and if
it is 2 or '--simple-values', print the name, type and value for simple
data types, and the name and type for arrays, structures and unions. If
the option '--no-frame-filters' is supplied, then Python frame filters
will not be executed.
If the '--skip-unavailable' option is specified, arguments that are
not available are not listed. Partially available arguments are still
displayed, however.
Use of this command to obtain arguments in a single frame is
deprecated in favor of the '-stack-list-variables' command.
GDB Command
...........
GDB does not have an equivalent command. 'gdbtk' has a 'gdb_get_args'
command which partially overlaps with the functionality of
'-stack-list-arguments'.
Example
.......
(gdb)
-stack-list-frames
^done,
stack=[
frame={level="0",addr="0x00010734",func="callee4",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
arch="i386:x86_64"},
frame={level="1",addr="0x0001076c",func="callee3",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="17",
arch="i386:x86_64"},
frame={level="2",addr="0x0001078c",func="callee2",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="22",
arch="i386:x86_64"},
frame={level="3",addr="0x000107b4",func="callee1",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="27",
arch="i386:x86_64"},
frame={level="4",addr="0x000107e0",func="main",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="32",
arch="i386:x86_64"}]
(gdb)
-stack-list-arguments 0
^done,
stack-args=[
frame={level="0",args=[]},
frame={level="1",args=[name="strarg"]},
frame={level="2",args=[name="intarg",name="strarg"]},
frame={level="3",args=[name="intarg",name="strarg",name="fltarg"]},
frame={level="4",args=[]}]
(gdb)
-stack-list-arguments 1
^done,
stack-args=[
frame={level="0",args=[]},
frame={level="1",
args=[{name="strarg",value="0x11940 \"A string argument.\""}]},
frame={level="2",args=[
{name="intarg",value="2"},
{name="strarg",value="0x11940 \"A string argument.\""}]},
{frame={level="3",args=[
{name="intarg",value="2"},
{name="strarg",value="0x11940 \"A string argument.\""},
{name="fltarg",value="3.5"}]},
frame={level="4",args=[]}]
(gdb)
-stack-list-arguments 0 2 2
^done,stack-args=[frame={level="2",args=[name="intarg",name="strarg"]}]
(gdb)
-stack-list-arguments 1 2 2
^done,stack-args=[frame={level="2",
args=[{name="intarg",value="2"},
{name="strarg",value="0x11940 \"A string argument.\""}]}]
(gdb)
The '-stack-list-frames' Command
--------------------------------
Synopsis
........
-stack-list-frames [ --no-frame-filters LOW-FRAME HIGH-FRAME ]
List the frames currently on the stack. For each frame it displays
the following info:
'LEVEL'
The frame number, 0 being the topmost frame, i.e., the innermost
function.
'ADDR'
The '$pc' value for that frame.
'FUNC'
Function name.
'FILE'
File name of the source file where the function lives.
'FULLNAME'
The full file name of the source file where the function lives.
'LINE'
Line number corresponding to the '$pc'.
'FROM'
The shared library where this function is defined. This is only
given if the frame's function is not known.
'ARCH'
Frame's architecture.
If invoked without arguments, this command prints a backtrace for the
whole stack. If given two integer arguments, it shows the frames whose
levels are between the two arguments (inclusive). If the two arguments
are equal, it shows the single frame at the corresponding level. It is
an error if LOW-FRAME is larger than the actual number of frames. On
the other hand, HIGH-FRAME may be larger than the actual number of
frames, in which case only existing frames will be returned. If the
option '--no-frame-filters' is supplied, then Python frame filters will
not be executed.
GDB Command
...........
The corresponding GDB commands are 'backtrace' and 'where'.
Example
.......
Full stack backtrace:
(gdb)
-stack-list-frames
^done,stack=
[frame={level="0",addr="0x0001076c",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="11",
arch="i386:x86_64"},
frame={level="1",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="2",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="3",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="4",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="5",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="6",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="7",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="8",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="9",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="10",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="11",addr="0x00010738",func="main",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4",
arch="i386:x86_64"}]
(gdb)
Show frames between LOW_FRAME and HIGH_FRAME:
(gdb)
-stack-list-frames 3 5
^done,stack=
[frame={level="3",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="4",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"},
frame={level="5",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"}]
(gdb)
Show a single frame:
(gdb)
-stack-list-frames 3 3
^done,stack=
[frame={level="3",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14",
arch="i386:x86_64"}]
(gdb)
The '-stack-list-locals' Command
--------------------------------
Synopsis
........
-stack-list-locals [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES
Display the local variable names for the selected frame. If
PRINT-VALUES is 0 or '--no-values', print only the names of the
variables; if it is 1 or '--all-values', print also their values; and if
it is 2 or '--simple-values', print the name, 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. If the option
'--no-frame-filters' is supplied, then Python frame filters will not be
executed.
If the '--skip-unavailable' option is specified, local variables that
are not available are not listed. Partially available local variables
are still displayed, however.
This command is deprecated in favor of the '-stack-list-variables'
command.
GDB Command
...........
'info locals' in GDB, 'gdb_get_locals' in 'gdbtk'.
Example
.......
(gdb)
-stack-list-locals 0
^done,locals=[name="A",name="B",name="C"]
(gdb)
-stack-list-locals --all-values
^done,locals=[{name="A",value="1"},{name="B",value="2"},
{name="C",value="{1, 2, 3}"}]
-stack-list-locals --simple-values
^done,locals=[{name="A",type="int",value="1"},
{name="B",type="int",value="2"},{name="C",type="int [3]"}]
(gdb)
The '-stack-list-variables' Command
-----------------------------------
Synopsis
........
-stack-list-variables [ --no-frame-filters ] [ --skip-unavailable ] PRINT-VALUES
Display the names of local variables and function arguments for the
selected frame. If PRINT-VALUES is 0 or '--no-values', print only the
names of the variables; if it is 1 or '--all-values', print also their
values; and if it is 2 or '--simple-values', print the name, type and
value for simple data types, and the name and type for arrays,
structures and unions. If the option '--no-frame-filters' is supplied,
then Python frame filters will not be executed.
If the '--skip-unavailable' option is specified, local variables and
arguments that are not available are not listed. Partially available
arguments and local variables are still displayed, however.
Example
.......
(gdb)
-stack-list-variables --thread 1 --frame 0 --all-values
^done,variables=[{name="x",value="11"},{name="s",value="{a = 1, b = 2}"}]
(gdb)
The '-stack-select-frame' Command
---------------------------------
Synopsis
........
-stack-select-frame FRAMENUM
Change the selected frame. Select a different frame FRAMENUM on the
stack.
This command in deprecated in favor of passing the '--frame' option
to every command.
GDB Command
...........
The corresponding GDB commands are 'frame', 'up', 'down',
'select-frame', 'up-silent', and 'down-silent'.
Example
.......
(gdb)
-stack-select-frame 2
^done
(gdb)
Info Catalog
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gdb: GDB/MI Variable Objects