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GDB/MI is a line based machine oriented text interface to GDB and is activated by specifying using the `--interpreter' command line option (see section 2.1.2 Choosing Modes). It is specifically intended to support the development of systems which use the debugger as just one small component of a larger system.
This chapter is a specification of the GDB/MI interface. It is written in the form of a reference manual.
Note that GDB/MI is still under construction, so some of the features described below are incomplete and subject to change (see section GDB/MI Development and Front Ends).
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This chapter uses the following notation:
| separates two alternatives.
[ something ] indicates that something is optional:
it may or may not be given.
( group )* means that group inside the parentheses
may repeat zero or more times.
( group )+ means that group inside the parentheses
may repeat one or more times.
"string" means a literal string.
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24.1.1 GDB/MI Input Syntax 24.1.2 GDB/MI Output Syntax
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command ==>
cli-command | mi-command
cli-command ==>
[ token ] cli-command nl, where
cli-command is any existing GDB CLI command.
mi-command ==>
[ token ] "-" operation ( " " option )*
[ " --" ] ( " " parameter )* nl
token ==>
option ==>
"-" parameter [ " " parameter ]
parameter ==>
non-blank-sequence | c-string
operation ==>
non-blank-sequence ==>
c-string ==>
""" seven-bit-iso-c-string-content """
nl ==>
CR | CR-LF
Notes:
token, when present, is passed back when the command
finishes.
Pragmatics:
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The output from GDB/MI consists of zero or more out-of-band records followed, optionally, by a single result record. This result record is for the most recent command. The sequence of output records is terminated by `(gdb)'.
If an input command was prefixed with a token then the
corresponding output for that command will also be prefixed by that same
token.
output ==>
( out-of-band-record )* [ result-record ] "(gdb)" nl
result-record ==>
[ token ] "^" result-class ( "," result )* nl
out-of-band-record ==>
async-record | stream-record
async-record ==>
exec-async-output | status-async-output | notify-async-output
exec-async-output ==>
[ token ] "*" async-output
status-async-output ==>
[ token ] "+" async-output
notify-async-output ==>
[ token ] "=" async-output
async-output ==>
async-class ( "," result )* nl
result-class ==>
"done" | "running" | "connected" | "error" | "exit"
async-class ==>
"stopped" | others (where others will be added
depending on the needs--this is still in development).
result ==>
variable "=" value
variable ==>
string
value ==>
const | tuple | list
const ==>
c-string
tuple ==>
"{}" | "{" result ( "," result )* "}"
list ==>
"[]" | "[" value ( "," value )* "]" | "["
result ( "," result )* "]"
stream-record ==>
console-stream-output | target-stream-output | log-stream-output
console-stream-output ==>
"~" c-string
target-stream-output ==>
"@" c-string
log-stream-output ==>
"&" c-string
nl ==>
CR | CR-LF
token ==>
Notes:
token is from the corresponding request. If an execution
command is interrupted by the `-exec-interrupt' command, the
token associated with the `*stopped' message is the one of the
original execution command, not the one of the interrupt command.
See section GDB/MI Stream Records, for more details about the various output records.
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For the developers convenience CLI commands can be entered directly,
but there may be some unexpected behaviour. For example, commands
that query the user will behave as if the user replied yes, breakpoint
command lists are not executed and some CLI commands, such as
if, when and define, prompt for further input with
`>', which is not valid MI output.
This feature may be removed at some stage in the future and it is
recommended that front ends use the -interpreter-exec command
(see -interpreter-exec).
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The application which takes the MI output and presents the state of the program being debugged to the user is called a front end.
Although GDB/MI is still incomplete, it is currently being used by a variety of front ends to GDB. This makes it difficult to introduce new functionality without breaking existing usage. This section tries to minimize the problems by describing how the protocol might change.
Some changes in MI need not break a carefully designed front end, and for these the MI version will remain unchanged. The following is a list of changes that may occur within one level, so front ends should parse MI output in a way that can handle them:
in_scope (see -var-update) may be extended.
If the changes are likely to break front ends, the MI version level will be increased by one. This will allow the front end to parse the output according to the MI version. Apart from mi0, new versions of GDB will not support old versions of MI and it will be the responsibility of the front end to work with the new one.
The best way to avoid unexpected changes in MI that might break your front end is to make your project known to GDB developers and follow development on gdb@sourceware.org and gdb-patches@sourceware.org. There is also the mailing list dmi-discuss@lists.freestandards.org, hosted by the Free Standards Group, which has the aim of creating a more general MI protocol called Debugger Machine Interface (DMI) that will become a standard for all debuggers, not just GDB.
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24.4.1 GDB/MI Result Records 24.4.2 GDB/MI Stream Records 24.4.3 GDB/MI Out-of-band Records
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In addition to a number of out-of-band notifications, the response to a GDB/MI command includes one of the following result indications:
"^done" [ "," results ]
results are the return
values.
"^running"
"^connected"
"^error" "," c-string
c-string contains the corresponding
error message.
"^exit"
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GDB internally maintains a number of output streams: the console, the target, and the log. The output intended for each of these streams is funneled through the GDB/MI interface using stream records.
Each stream record begins with a unique prefix character which
identifies its stream (see section GDB/MI Output Syntax). In addition to the prefix, each stream record contains a
string-output. This is either raw text (with an implicit new
line) or a quoted C string (which does not contain an implicit newline).
"~" string-output
"@" string-output
"&" string-output
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Out-of-band records are used to notify the GDB/MI client of additional changes that have occurred. Those changes can either be a consequence of GDB/MI (e.g., a breakpoint modified) or a result of target activity (e.g., target stopped).
The following is a preliminary list of possible out-of-band records. In particular, the exec-async-output records.
*stopped,reason="reason"
reason can be one of the following:
breakpoint-hit
watchpoint-trigger
read-watchpoint-trigger
access-watchpoint-trigger
function-finished
location-reached
watchpoint-scope
end-stepping-range
exited-signalled
exited
exited-normally
signal-received
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This subsection presents several simple examples of interaction using the GDB/MI interface. In these examples, `->' means that the following line is passed to GDB/MI as input, while `<-' means the output received from GDB/MI.
Note the line breaks shown in the examples are here only for readability, they don't appear in the real output.
Setting a breakpoint generates synchronous output which contains detailed information of the breakpoint.
-> -break-insert main
<- ^done,bkpt={number="1",type="breakpoint",disp="keep",
enabled="y",addr="0x08048564",func="main",file="myprog.c",
fullname="/home/nickrob/myprog.c",line="68",times="0"}
<- (gdb)
|
Program execution generates asynchronous records and MI gives the reason that execution stopped.
-> -exec-run
<- ^running
<- (gdb)
<- *stopped,reason="breakpoint-hit",bkptno="1",thread-id="0",
frame={addr="0x08048564",func="main",
args=[{name="argc",value="1"},{name="argv",value="0xbfc4d4d4"}],
file="myprog.c",fullname="/home/nickrob/myprog.c",line="68"}
<- (gdb)
-> -exec-continue
<- ^running
<- (gdb)
<- *stopped,reason="exited-normally"
<- (gdb)
|
Quitting GDB just prints the result class `^exit'.
-> (gdb) <- -gdb-exit <- ^exit |
Here's what happens if you pass a non-existent command:
-> -rubbish <- ^error,msg="Undefined MI command: rubbish" <- (gdb) |
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The remaining sections describe blocks of commands. Each block of commands is laid out in a fashion similar to this section.
The motivation for this collection of commands.
A brief introduction to this collection of commands as a whole.
For each command in the block, the following is described:
-command args... |
The corresponding GDB CLI command(s), if any.
Example(s) formatted for readability. Some of the described commands have not been implemented yet and these are labeled N.A. (not available).
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This section documents GDB/MI commands for manipulating breakpoints.
-break-after Command
-break-after number count |
The breakpoint number number is not in effect until it has been hit count times. To see how this is reflected in the output of the `-break-list' command, see the description of the `-break-list' command below.
The corresponding GDB command is `ignore'.
(gdb)
-break-insert main
^done,bkpt={number="1",addr="0x000100d0",file="hello.c",
fullname="/home/foo/hello.c",line="5",times="0"}
(gdb)
-break-after 1 3
~
^done
(gdb)
-break-list
^done,BreakpointTable={nr_rows="1",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
line="5",times="0",ignore="3"}]}
(gdb)
|
-break-condition Command
-break-condition number expr |
Breakpoint number will stop the program only if the condition in expr is true. The condition becomes part of the `-break-list' output (see the description of the `-break-list' command below).
The corresponding GDB command is `condition'.
(gdb)
-break-condition 1 1
^done
(gdb)
-break-list
^done,BreakpointTable={nr_rows="1",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
line="5",cond="1",times="0",ignore="3"}]}
(gdb)
|
-break-delete Command
-break-delete ( breakpoint )+ |
Delete the breakpoint(s) whose number(s) are specified in the argument list. This is obviously reflected in the breakpoint list.
The corresponding GDB command is `delete'.
(gdb)
-break-delete 1
^done
(gdb)
-break-list
^done,BreakpointTable={nr_rows="0",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[]}
(gdb)
|
-break-disable Command
-break-disable ( breakpoint )+ |
Disable the named breakpoint(s). The field `enabled' in the break list is now set to `n' for the named breakpoint(s).
The corresponding GDB command is `disable'.
(gdb)
-break-disable 2
^done
(gdb)
-break-list
^done,BreakpointTable={nr_rows="1",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="n",
addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
line="5",times="0"}]}
(gdb)
|
-break-enable Command
-break-enable ( breakpoint )+ |
Enable (previously disabled) breakpoint(s).
The corresponding GDB command is `enable'.
(gdb)
-break-enable 2
^done
(gdb)
-break-list
^done,BreakpointTable={nr_rows="1",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",fullname="/home/foo/hello.c",
line="5",times="0"}]}
(gdb)
|
-break-info Command
-break-info breakpoint |
Get information about a single breakpoint.
The corresponding GDB command is `info break breakpoint'.
-break-insert Command
-break-insert [ -t ] [ -h ] [ -f ]
[ -c condition ] [ -i ignore-count ]
[ -p thread ] [ location ]
|
If specified, location, can be one of:
The possible optional parameters of this command are:
The result is in the form:
^done,bkpt={number="number",type="type",disp="del"|"keep",
enabled="y"|"n",addr="hex",func="funcname",file="filename",
fullname="full_filename",line="lineno",[thread="threadno,]
times="times"}
|
where number is the GDB number for this breakpoint, funcname is the name of the function where the breakpoint was inserted, filename is the name of the source file which contains this function, lineno is the source line number within that file and times the number of times that the breakpoint has been hit (always 0 for -break-insert but may be greater for -break-info or -break-list which use the same output).
Note: this format is open to change.
The corresponding GDB commands are `break', `tbreak', `hbreak', `thbreak', and `rbreak'.
(gdb)
-break-insert main
^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",
fullname="/home/foo/recursive2.c,line="4",times="0"}
(gdb)
-break-insert -t foo
^done,bkpt={number="2",addr="0x00010774",file="recursive2.c",
fullname="/home/foo/recursive2.c,line="11",times="0"}
(gdb)
-break-list
^done,BreakpointTable={nr_rows="2",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x0001072c", func="main",file="recursive2.c",
fullname="/home/foo/recursive2.c,"line="4",times="0"},
bkpt={number="2",type="breakpoint",disp="del",enabled="y",
addr="0x00010774",func="foo",file="recursive2.c",
fullname="/home/foo/recursive2.c",line="11",times="0"}]}
(gdb)
-break-insert -r foo.*
~int foo(int, int);
^done,bkpt={number="3",addr="0x00010774",file="recursive2.c,
"fullname="/home/foo/recursive2.c",line="11",times="0"}
(gdb)
|
-break-list Command
-break-list |
Displays the list of inserted breakpoints, showing the following fields:
If there are no breakpoints or watchpoints, the BreakpointTable
body field is an empty list.
The corresponding GDB command is `info break'.
(gdb)
-break-list
^done,BreakpointTable={nr_rows="2",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",line="5",times="0"},
bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
addr="0x00010114",func="foo",file="hello.c",fullname="/home/foo/hello.c",
line="13",times="0"}]}
(gdb)
|
Here's an example of the result when there are no breakpoints:
(gdb)
-break-list
^done,BreakpointTable={nr_rows="0",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[]}
(gdb)
|
-break-watch Command
-break-watch [ -a | -r ] |
Create a watchpoint. With the `-a' option it will create an access watchpoint, i.e., a watchpoint that triggers either on a read from or on a write to the memory location. With the `-r' option, the watchpoint created is a read watchpoint, i.e., it will trigger only when the memory location is accessed for reading. Without either of the options, the watchpoint created is a regular watchpoint, i.e., it will trigger when the memory location is accessed for writing. See section Setting Watchpoints.
Note that `-break-list' will report a single list of watchpoints and breakpoints inserted.
The corresponding GDB commands are `watch', `awatch', and `rwatch'.
Setting a watchpoint on a variable in the main function:
(gdb)
-break-watch x
^done,wpt={number="2",exp="x"}
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-trigger",wpt={number="2",exp="x"},
value={old="-268439212",new="55"},
frame={func="main",args=[],file="recursive2.c",
fullname="/home/foo/bar/recursive2.c",line="5"}
(gdb)
|
Setting a watchpoint on a variable local to a function. GDB will stop the program execution twice: first for the variable changing value, then for the watchpoint going out of scope.
(gdb)
-break-watch C
^done,wpt={number="5",exp="C"}
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-trigger",
wpt={number="5",exp="C"},value={old="-276895068",new="3"},
frame={func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-scope",wpnum="5",
frame={func="callee3",args=[{name="strarg",
value="0x11940 \"A string argument.\""}],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
(gdb)
|
Listing breakpoints and watchpoints, at different points in the program execution. Note that once the watchpoint goes out of scope, it is deleted.
(gdb)
-break-watch C
^done,wpt={number="2",exp="C"}
(gdb)
-break-list
^done,BreakpointTable={nr_rows="2",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c"line="8",times="1"},
bkpt={number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="0"}]}
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-trigger",wpt={number="2",exp="C"},
value={old="-276895068",new="3"},
frame={func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="13"}
(gdb)
-break-list
^done,BreakpointTable={nr_rows="2",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"},
bkpt={number="2",type="watchpoint",disp="keep",
enabled="y",addr="",what="C",times="-5"}]}
(gdb)
-exec-continue
^running
^done,reason="watchpoint-scope",wpnum="2",
frame={func="callee3",args=[{name="strarg",
value="0x11940 \"A string argument.\""}],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
(gdb)
-break-list
^done,BreakpointTable={nr_rows="1",nr_cols="6",
hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"},
{width="14",alignment="-1",col_name="type",colhdr="Type"},
{width="4",alignment="-1",col_name="disp",colhdr="Disp"},
{width="3",alignment="-1",col_name="enabled",colhdr="Enb"},
{width="10",alignment="-1",col_name="addr",colhdr="Address"},
{width="40",alignment="2",col_name="what",colhdr="What"}],
body=[bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/devo/gdb/testsuite/gdb.mi/basics.c",line="8",
times="1"}]}
(gdb)
|
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-exec-arguments Command
-exec-arguments args |
Set the inferior program arguments, to be used in the next `-exec-run'.
The corresponding GDB command is `set args'.
Don't have one around.
-exec-show-arguments Command
-exec-show-arguments |
Print the arguments of the program.
The corresponding GDB command is `show args'.
-environment-cd Command
-environment-cd pathdir |
Set GDB's working directory.
The corresponding GDB command is `cd'.
(gdb) -environment-cd /kwikemart/marge/ezannoni/flathead-dev/devo/gdb ^done (gdb) |
-environment-directory Command
-environment-directory [ -r ] [ pathdir ]+ |
Add directories pathdir to beginning of search path for source files. If the `-r' option is used, the search path is reset to the default search path. If directories pathdir are supplied in addition to the `-r' option, the search path is first reset and then addition occurs as normal. Multiple directories may be specified, separated by blanks. Specifying multiple directories in a single command results in the directories added to the beginning of the search path in the same order they were presented in the command. If blanks are needed as part of a directory name, double-quotes should be used around the name. In the command output, the path will show up separated by the system directory-separator character. The directory-separator character must not be used in any directory name. If no directories are specified, the current search path is displayed.
The corresponding GDB command is `dir'.
(gdb) -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" (gdb) -environment-directory "" ^done,source-path="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb:$cdir:$cwd" (gdb) -environment-directory -r /home/jjohnstn/src/gdb /usr/src ^done,source-path="/home/jjohnstn/src/gdb:/usr/src:$cdir:$cwd" (gdb) -environment-directory -r ^done,source-path="$cdir:$cwd" (gdb) |
-environment-path Command
-environment-path [ -r ] [ pathdir ]+ |
Add directories pathdir to beginning of search path for object files. If the `-r' option is used, the search path is reset to the original search path that existed at gdb start-up. If directories pathdir are supplied in addition to the `-r' option, the search path is first reset and then addition occurs as normal. Multiple directories may be specified, separated by blanks. Specifying multiple directories in a single command results in the directories added to the beginning of the search path in the same order they were presented in the command. If blanks are needed as part of a directory name, double-quotes should be used around the name. In the command output, the path will show up separated by the system directory-separator character. The directory-separator character must not be used in any directory name. If no directories are specified, the current path is displayed.
The corresponding GDB command is `path'.
(gdb) -environment-path ^done,path="/usr/bin" (gdb) -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb /bin ^done,path="/kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb:/bin:/usr/bin" (gdb) -environment-path -r /usr/local/bin ^done,path="/usr/local/bin:/usr/bin" (gdb) |
-environment-pwd Command
-environment-pwd |
Show the current working directory.
The corresponding GDB command is `pwd'.
(gdb) -environment-pwd ^done,cwd="/kwikemart/marge/ezannoni/flathead-dev/devo/gdb" (gdb) |
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-thread-info Command
-thread-info |
No equivalent.
-thread-list-all-threads Command
-thread-list-all-threads |
The equivalent GDB command is `info threads'.
-thread-list-ids Command
-thread-list-ids |
Produces a list of the currently known GDB thread ids. At the end of the list it also prints the total number of such threads.
Part of `info threads' supplies the same information.
No threads present, besides the main process:
(gdb)
-thread-list-ids
^done,thread-ids={},number-of-threads="0"
(gdb)
|
Several threads:
(gdb)
-thread-list-ids
^done,thread-ids={thread-id="3",thread-id="2",thread-id="1"},
number-of-threads="3"
(gdb)
|
-thread-select Command
-thread-select threadnum |
Make threadnum the current thread. It prints the number of the new current thread, and the topmost frame for that thread.
The corresponding GDB command is `thread'.
(gdb)
-exec-next
^running
(gdb)
*stopped,reason="end-stepping-range",thread-id="2",line="187",
file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c"
(gdb)
-thread-list-ids
^done,
thread-ids={thread-id="3",thread-id="2",thread-id="1"},
number-of-threads="3"
(gdb)
-thread-select 3
^done,new-thread-id="3",
frame={level="0",func="vprintf",
args=[{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""},
{name="arg",value="0x2"}],file="vprintf.c",line="31"}
(gdb)
|
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These are the asynchronous commands which generate the out-of-band record `*stopped'. Currently GDB only really executes asynchronously with remote targets and this interaction is mimicked in other cases.
-exec-continue Command
-exec-continue |
Resumes the execution of the inferior program until a breakpoint is encountered, or until the inferior exits.
The corresponding GDB corresponding is `continue'.
-exec-continue
^running
(gdb)
@Hello world
*stopped,reason="breakpoint-hit",bkptno="2",frame={func="foo",args=[],
file="hello.c",fullname="/home/foo/bar/hello.c",line="13"}
(gdb)
|
-exec-finish Command
-exec-finish |
Resumes the execution of the inferior program until the current function is exited. Displays the results returned by the function.
The corresponding GDB command is `finish'.
Function returning void.
-exec-finish
^running
(gdb)
@hello from foo
*stopped,reason="function-finished",frame={func="main",args=[],
file="hello.c",fullname="/home/foo/bar/hello.c",line="7"}
(gdb)
|
Function returning other than void. The name of the internal
GDB variable storing the result is printed, together with the
value itself.
-exec-finish
^running
(gdb)
*stopped,reason="function-finished",frame={addr="0x000107b0",func="foo",
args=[{name="a",value="1"],{name="b",value="9"}},
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
gdb-result-var="$1",return-value="0"
(gdb)
|
-exec-interrupt Command
-exec-interrupt |
Interrupts the background execution of the target. Note how the token associated with the stop message is the one for the execution command that has been interrupted. The token for the interrupt itself only appears in the `^done' output. If the user is trying to interrupt a non-running program, an error message will be printed.
The corresponding GDB command is `interrupt'.
(gdb)
111-exec-continue
111^running
(gdb)
222-exec-interrupt
222^done
(gdb)
111*stopped,signal-name="SIGINT",signal-meaning="Interrupt",
frame={addr="0x00010140",func="foo",args=[],file="try.c",
fullname="/home/foo/bar/try.c",line="13"}
(gdb)
(gdb)
-exec-interrupt
^error,msg="mi_cmd_exec_interrupt: Inferior not executing."
(gdb)
|
-exec-next Command
-exec-next |
Resumes execution of the inferior program, stopping when the beginning of the next source line is reached.
The corresponding GDB command is `next'.
-exec-next ^running (gdb) *stopped,reason="end-stepping-range",line="8",file="hello.c" (gdb) |
-exec-next-instruction Command
-exec-next-instruction |
Executes one machine instruction. If the instruction is a function call, continues until the function returns. If the program stops at an instruction in the middle of a source line, the address will be printed as well.
The corresponding GDB command is `nexti'.
(gdb) -exec-next-instruction ^running (gdb) *stopped,reason="end-stepping-range", addr="0x000100d4",line="5",file="hello.c" (gdb) |
-exec-return Command
-exec-return |
Makes current function return immediately. Doesn't execute the inferior. Displays the new current frame.
The corresponding GDB command is `return'.
(gdb)
200-break-insert callee4
200^done,bkpt={number="1",addr="0x00010734",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8"}
(gdb)
000-exec-run
000^running
(gdb)
000*stopped,reason="breakpoint-hit",bkptno="1",
frame={func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="8"}
(gdb)
205-break-delete
205^done
(gdb)
111-exec-return
111^done,frame={level="0",func="callee3",
args=[{name="strarg",
value="0x11940 \"A string argument.\""}],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
fullname="/home/foo/bar/devo/gdb/testsuite/gdb.mi/basics.c",line="18"}
(gdb)
|
-exec-run Command
-exec-run |
Starts execution of the inferior from the beginning. The inferior executes until either a breakpoint is encountered or the program exits. In the latter case the output will include an exit code, if the program has exited exceptionally.
The corresponding GDB command is `run'.
(gdb)
-break-insert main
^done,bkpt={number="1",addr="0x0001072c",file="recursive2.c",line="4"}
(gdb)
-exec-run
^running
(gdb)
*stopped,reason="breakpoint-hit",bkptno="1",
frame={func="main",args=[],file="recursive2.c",
fullname="/home/foo/bar/recursive2.c",line="4"}
(gdb)
|
Program exited normally:
(gdb) -exec-run ^running (gdb) x = 55 *stopped,reason="exited-normally" (gdb) |
Program exited exceptionally:
(gdb) -exec-run ^running (gdb) x = 55 *stopped,reason="exited",exit-code="01" (gdb) |
Another way the program can terminate is if it receives a signal such as
SIGINT. In this case, GDB/MI displays this:
(gdb) *stopped,reason="exited-signalled",signal-name="SIGINT", signal-meaning="Interrupt" |
-exec-step Command
-exec-step |
Resumes execution of the inferior program, stopping when the beginning of the next source line is reached, if the next source line is not a function call. If it is, stop at the first instruction of the called function.
The corresponding GDB command is `step'.
Stepping into a function:
-exec-step
^running
(gdb)
*stopped,reason="end-stepping-range",
frame={func="foo",args=[{name="a",value="10"},
{name="b",value="0"}],file="recursive2.c",
fullname="/home/foo/bar/recursive2.c",line="11"}
(gdb)
|
Regular stepping:
-exec-step ^running (gdb) *stopped,reason="end-stepping-range",line="14",file="recursive2.c" (gdb) |
-exec-step-instruction Command
-exec-step-instruction |
Resumes the inferior which executes one machine instruction. The output, once GDB has stopped, will vary depending on whether we have stopped in the middle of a source line or not. In the former case, the address at which the program stopped will be printed as well.
The corresponding GDB command is `stepi'.
(gdb)
-exec-step-instruction
^running
(gdb)
*stopped,reason="end-stepping-range",
frame={func="foo",args=[],file="try.c",
fullname="/home/foo/bar/try.c",line="10"}
(gdb)
-exec-step-instruction
^running
(gdb)
*stopped,reason="end-stepping-range",
frame={addr="0x000100f4",func="foo",args=[],file="try.c",
fullname="/home/foo/bar/try.c",line="10"}
(gdb)
|
-exec-until Command
-exec-until [ location ] |
Executes the inferior until the location specified in the argument is reached. If there is no argument, the inferior executes until a source line greater than the current one is reached. The reason for stopping in this case will be `location-reached'.
The corresponding GDB command is `until'.
(gdb)
-exec-until recursive2.c:6
^running
(gdb)
x = 55
*stopped,reason="location-reached",frame={func="main",args=[],
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="6"}
(gdb)
|
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-stack-info-frame Command
-stack-info-frame |
Get info on the selected frame.
The corresponding GDB command is `info frame' or `frame' (without arguments).
(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"}
(gdb)
|
-stack-info-depth Command
-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.
There's no equivalent GDB command.
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) |
-stack-list-arguments Command
-stack-list-arguments show-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.
The show-values argument must have a value of 0 or 1. A value of 0 means that only the names of the arguments are listed, a value of 1 means that both names and values of the arguments are printed.
GDB does not have an equivalent command. gdbtk has a
`gdb_get_args' command which partially overlaps with the
functionality of `-stack-list-arguments'.
(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"},
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"},
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"},
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"},
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"}]
(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)
|
-stack-list-frames Command
-stack-list-frames [ low-frame high-frame ] |
List the frames currently on the stack. For each frame it displays the following info:
$pc value for that frame.
$pc.
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.
The corresponding GDB commands are `backtrace' and `where'.
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"},
frame={level="1",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="2",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="3",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="4",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="5",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="6",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="7",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="8",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="9",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="10",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="11",addr="0x00010738",func="main",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="4"}]
(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"},
frame={level="4",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"},
frame={level="5",addr="0x000107a4",func="foo",
file="recursive2.c",fullname="/home/foo/bar/recursive2.c",line="14"}]
(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"}]
(gdb)
|
-stack-list-locals Command
-stack-list-locals 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.
`info locals' in GDB, `gdb_get_locals' in gdbtk.
(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)
|
-stack-select-frame Command
-stack-select-frame framenum |
Change the selected frame. Select a different frame framenum on the stack.
The corresponding GDB commands are `frame', `up', `down', `select-frame', `up-silent', and `down-silent'.
(gdb) -stack-select-frame 2 ^done (gdb) |
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Variable objects are "object-oriented" MI interface for examining and changing values of expressions. Unlike some other MI interfaces that work with expressions, variable objects are specifically designed for simple and efficient presentation in the frontend. A variable object is identified by string name. When a variable object is created, the frontend specifies the expression for that variable object. The expression can be a simple variable, or it can be an arbitrary complex expression, and can even involve CPU registers. After creating a variable object, the frontend can invoke other variable object operations--for example to obtain or change the value of a variable object, or to change display format.
Variable objects have hierarchical tree structure. Any variable object that corresponds to a composite type, such as structure in C, has a number of child variable objects, for example corresponding to each element of a structure. A child variable object can itself have children, recursively. Recursion ends when we reach leaf variable objects, which always have built-in types. Child variable objects are created only by explicit request, so if a frontend is not interested in the children of a particular variable object, no child will be created.
For a leaf variable object it is possible to obtain its value as a string, or set the value from a string. String value can be also obtained for a non-leaf variable object, but it's generally a string that only indicates the type of the object, and does not list its contents. Assignment to a non-leaf variable object is not allowed. A frontend does not need to read the values of all variable objects each time the program stops. Instead, MI provides an update command that lists all variable objects whose values has changed since the last update operation. This considerably reduces the amount of data that must be transferred to the frontend. As noted above, children variable objects are created on demand, and only leaf variable objects have a real value. As result, gdb will read target memory only for leaf variables that frontend has created.
The automatic update is not always desirable. For example, a frontend might want to keep a value of some expression for future reference, and never update it. For another example, fetching memory is relatively slow for embedded targets, so a frontend might want to disable automatic update for the variables that are either not visible on the screen, or "closed". This is possible using so called "frozen variable objects". Such variable objects are never implicitly updated.
The following is the complete set of GDB/MI operations defined to access this functionality:
| Operation | Description |
-var-create |
create a variable object |
-var-delete |
delete the variable object and/or its children |
-var-set-format |
set the display format of this variable |
-var-show-format |
show the display format of this variable |
-var-info-num-children |
tells how many children this object has |
-var-list-children |
return a list of the object's children |
-var-info-type |
show the type of this variable object |
-var-info-expression |
print parent-relative expression that this variable object represents |
-var-info-path-expression |
print full expression that this variable object represents |
-var-show-attributes |
is this variable editable? does it exist here? |
-var-evaluate-expression |
get the value of this variable |
-var-assign |
set the value of this variable |
-var-update |
update the variable and its children |
-var-set-frozen |
set frozeness attribute |
In the next subsection we describe each operation in detail and suggest how it can be used.
-var-create Command
-var-create {name | "-"}
{frame-addr | "*"} expression
|
This operation creates a variable object, which allows the monitoring of a variable, the result of an expression, a memory cell or a CPU register.
The name parameter is the string by which the object can be referenced. It must be unique. If `-' is specified, the varobj system will generate a string "varNNNNNN" automatically. It will be unique provided that one does not specify name on that format. The command fails if a duplicate name is found.
The frame under which the expression should be evaluated can be specified by frame-addr. A `*' indicates that the current frame should be used.
expression is any expression valid on the current language set (must not begin with a `*'), or one of the following:
This operation returns the name, number of children and the type of the object created. Type is returned as a string as the ones generated by the GDB CLI:
name="name",numchild="N",type="type" |
-var-delete Command
-var-delete [ -c ] name |
Deletes a previously created variable object and all of its children. With the `-c' option, just deletes the children.
Returns an error if the object name is not found.
-var-set-format Command
-var-set-format name format-spec |
Sets the output format for the value of the object name to be format-spec.
The syntax for the format-spec is as follows:
format-spec ==>
{binary | decimal | hexadecimal | octal | natural}
|
The natural format is the default format choosen automatically
based on the variable type (like decimal for an int, hex
for pointers, etc.).
For a variable with children, the format is set only on the variable itself, and the children are not affected.
-var-show-format Command
-var-show-format name |
Returns the format used to display the value of the object name.
format ==> format-spec |
-var-info-num-children Command
-var-info-num-children name |
Returns the number of children of a variable object name:
numchild=n |
-var-list-children Command
-var-list-children [print-values] name |
Return a list of the children of the specified variable object and
create variable objects for them, if they do not already exist. With
a single argument or if print-values has a value for of 0 or
--no-values, print only the names of the variables; if
print-values is 1 or --all-values, also print their
values; and if it is 2 or --simple-values print the name and
value for simple data types and just the name for arrays, structures
and unions.
(gdb)
-var-list-children n
^done,numchild=n,children=[{name=name,
numchild=n,type=type},(repeats N times)]
(gdb)
-var-list-children --all-values n
^done,numchild=n,children=[{name=name,
numchild=n,value=value,type=type},(repeats N times)]
|
-var-info-type Command
-var-info-type name |
Returns the type of the specified variable name. The type is returned as a string in the same format as it is output by the GDB CLI:
type=typename |
-var-info-expression Command
-var-info-expression name |
Returns a string that is suitable for presenting this variable object in user interface. The string is generally not valid expression in the current language, and cannot be evaluated.
For example, if a is an array, and variable object
A was created for a, then we'll get this output:
(gdb) -var-info-expression A.1 ^done,lang="C",exp="1" |
Here, the values of lang can be {"C" | "C++" | "Java"}.
Note that the output of the -var-list-children command also
includes those expressions, so the -var-info-expression command
is of limited use.
-var-info-path-expression Command
-var-info-path-expression name |
Returns an expression that can be evaluated in the current
context and will yield the same value that a variable object has.
Compare this with the -var-info-expression command, which
result can be used only for UI presentation. Typical use of
the -var-info-path-expression command is creating a
watchpoint from a variable object.
For example, suppose C is a C++ class, derived from class
Base, and that the Base class has a member called
m_size. Assume a variable c is has the type of
C and a variable object C was created for variable
c. Then, we'll get this output:
(gdb) -var-info-path-expression C.Base.public.m_size ^done,path_expr=((Base)c).m_size) |
-var-show-attributes Command
-var-show-attributes name |
List attributes of the specified variable object name:
status=attr [ ( ,attr )* ] |
where attr is { { editable | noneditable } | TBD }.
-var-evaluate-expression Command
-var-evaluate-expression name |
Evaluates the expression that is represented by the specified variable
object and returns its value as a string. The format of the
string can be changed using the -var-set-format command.
value=value |
Note that one must invoke -var-list-children for a variable
before the value of a child variable can be evaluated.
-var-assign Command
-var-assign name expression |
Assigns the value of expression to the variable object specified
by name. The object must be `editable'. If the variable's
value is altered by the assign, the variable will show up in any
subsequent -var-update list.
(gdb)
-var-assign var1 3
^done,value="3"
(gdb)
-var-update *
^done,changelist=[{name="var1",in_scope="true",type_changed="false"}]
(gdb)
|
-var-update Command
-var-update [print-values] {name | "*"}
|
Reevaluate the expressions corresponding to the variable object
name and all its direct and indirect children, and return the
list of variable objects whose values have changed; name must
be a root variable object. Here, "changed" means that the result of
-var-evaluate-expression before and after the
-var-update is different. If `*' is used as the variable
object names, all existing variable objects are updated, except
for frozen ones (see -var-set-frozen). The option
print-values determines whether both names and values, or just
names are printed. The possible values of this options are the same
as for -var-list-children (see -var-list-children). It is
recommended to use the `--all-values' option, to reduce the
number of MI commands needed on each program stop.
(gdb)
-var-assign var1 3
^done,value="3"
(gdb)
-var-update --all-values var1
^done,changelist=[{name="var1",value="3",in_scope="true",
type_changed="false"}]
(gdb)
|
The field in_scope may take three values:
"true"
"false"
"invalid"
file
command. The front end should normally choose to delete these variable
objects.
In the future new values may be added to this list so the front should be prepared for this possibility. See section GDB/MI Development and Front Ends.
-var-set-frozen Command
-var-set-frozen name flag |
Set the frozenness flag on the variable object name. The
flag parameter should be either `1' to make the variable
frozen or `0' to make it unfrozen. If a variable object is
frozen, then neither itself, nor any of its children, are
implicitly updated by -var-update of
a parent variable or by -var-update *. Only
-var-update of the variable itself will update its value and
values of its children. After a variable object is unfrozen, it is
implicitly updated by all subsequent -var-update operations.
Unfreezing a variable does not update it, only subsequent
-var-update does.
(gdb) -var-set-frozen V 1 ^done (gdb) |
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This section describes the GDB/MI commands that manipulate data: examine memory and registers, evaluate expressions, etc.
-data-disassemble Command
-data-disassemble
[ -s start-addr -e end-addr ]
| [ -f filename -l linenum [ -n lines ] ]
-- mode
|
Where:
$pc)
The output for each instruction is composed of four fields:
Note that whatever included in the instruction field, is not manipulated directly by GDB/MI, i.e., it is not possible to adjust its format.
There's no direct mapping from this command to the CLI.
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="/kwikemart/marge/ezannoni/flathead-dev/devo/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="/kwikemart/marge/ezannoni/flathead-dev/devo/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)
|
-data-evaluate-expression Command
-data-evaluate-expression expr |
Evaluate expr as an expression. The expression could contain an inferior function call. The function call will execute synchronously. If the expression contains spaces, it must be enclosed in double quotes.
The corresponding GDB commands are `print', `output', and
`call'. In gdbtk only, there's a corresponding
`gdb_eval' command.
In the following example, the numbers that precede the commands are the tokens described in GDB/MI Command Syntax. Notice how GDB/MI returns the same tokens in its output.
211-data-evaluate-expression A 211^done,value="1" (gdb) 311-data |