GDB/MI is a line based machine oriented text interface to GDB. 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.
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.
In alphabetic order: Andrew Cagney, Fernando Nasser, Stan Shebs and Elena Zannoni.
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 ==>
"any sequence of digits"
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:
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 ==>
[ string "=" ] value
value ==>
const | "{" result ( "," result )* "}"
const ==>
c-string
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 ==>
In addition, the following are still being developed:
query
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.
See section GDB/MI Draft Changes to Output Syntax, for proposed revisions to the current output syntax.
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.
Here's an example of stopping the inferior process:
-> -stop <- (gdb)
and later:
<- *stop,reason="stop",address="0x123",source="a.c:123" <- (gdb)
Here's an example of a simple CLI command being passed through GDB/MI and on to the CLI.
-> print 1+2 <- ~3\n <- (gdb)
-> -symbol-file xyz.exe <- *breakpoint,nr="3",address="0x123",source="a.c:123" <- (gdb)
Here's what happens if you pass a non-existent command:
-> -rubbish <- error,"Rubbish not found" <- (gdb)
To help users familiar with GDB's existing CLI interface, GDB/MI accepts existing CLI commands. As specified by the syntax, such commands can be directly entered into the GDB/MI interface and GDB will respond.
This mechanism is provided as an aid to developers of GDB/MI clients and not as a reliable interface into the CLI. Since the command is being interpreteted in an environment that assumes GDB/MI behaviour, the exact output of such commands is likely to end up being an un-supported hybrid of GDB/MI and CLI output.
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 is the return
value.
"^running"
"^error" "," c-string
c-string contains the corresponding
error message.
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
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.
"*" "stop"
The remaining sections describe blocks of commands. Each block of commands is laid out in a fashion similar to this chapter.
Note the the line breaks shown in the examples are here only for readability. They don't appear in the real output. Also note that the commands with a non-available example (N.A.) are not yet implemented.
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.
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",line="5"}
(gdb)
-break-after 1 3
~
^done
(gdb)
-break-list
^done,BreakpointTable={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="hello.c",line="5",times="0",
ignore="3"}}
(gdb)
-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={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="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={}
(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={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="2",type="breakpoint",disp="keep",enabled="n",
addr="0x000100d0",func="main",file="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={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
addr="0x000100d0",func="main",file="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'.
N.A.
-break-insert Command
-break-insert [ -t ] [ -h ] [ -r ]
[ -c condition ] [ -i ignore-count ]
[ -p thread ] [ line | addr ]
If specified, line, can be one of:
The possible optional parameters of this command are:
The result is in the form:
^done,bkptno="number",func="funcname", file="filename",line="lineno"
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, and lineno is the source line number within that file.
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",line="4"}
(gdb)
-break-insert -t foo
^done,bkpt={number="2",addr="0x00010774",file="recursive2.c",line="11"}
(gdb)
-break-list
^done,BreakpointTable={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x0001072c", func="main",file="recursive2.c",line="4",times="0"},
bkpt={number="2",type="breakpoint",disp="del",enabled="y",
addr="0x00010774",func="foo",file="recursive2.c",line="11",times="0"}}
(gdb)
-break-insert -r foo.*
~int foo(int, int);
^done,bkpt={number="3",addr="0x00010774",file="recursive2.c",line="11"}
(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 field is an empty list.
The corresponding GDB command is `info break'.
(gdb)
-break-list
^done,BreakpointTable={hdr={"Num","Type","Disp","Enb","Address","What"},
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",line="13",times="0"}}
(gdb)
Here's an example of the result when there are no breakpoints:
(gdb)
-break-list
^done,BreakpointTable={}
(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
^done,reason="watchpoint-trigger",wpt={number="2",exp="x"},
value={old="-268439212",new="55"},
frame={func="main",args={},file="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
^done,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",line="13"}
(gdb)
-exec-continue
^running
^done,reason="watchpoint-scope",wpnum="5",
frame={func="callee3",args={{name="strarg",
value="0x11940 \"A string argument.\""}},
file="../../../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={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../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
^done,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",line="13"}
(gdb)
-break-list
^done,BreakpointTable={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../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",line="18"}
(gdb)
-break-list
^done,BreakpointTable={hdr={"Num","Type","Disp","Enb","Address","What"},
bkpt={number="1",type="breakpoint",disp="keep",enabled="y",
addr="0x00010734",func="callee4",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="8",times="1"}}
(gdb)
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 two fields:
Note that whatever included in the instruction field, is not manipulated directely by flathead, 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 section 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-evaluate-expression &A 311^done,value="0xefffeb7c" (gdb) 411-data-evaluate-expression A+3 411^done,value="4" (gdb) 511-data-evaluate-expression "A + 3" 511^done,value="4" (gdb)
-data-list-changed-registers Command-data-list-changed-registers
Display a list of the registers that have changed.
GDB doesn't have a direct analog for this command; gdbtk has the
corresponding command `gdb_changed_register_list'.
On a PPC MBX board:
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="breakpoint-hit",bkptno="1",frame={func="main",
args={},file="try.c",line="5"}
(gdb)
-data-list-changed-registers
^done,changed-registers={"0","1","2","4","5","6","7","8","9",
"10","11","13","14","15","16","17","18","19","20","21","22","23",
"24","25","26","27","28","30","31","64","65","66","67","69"}
(gdb)
-data-list-register-names Command-data-list-register-names [ ( regno )+ ]
Show a list of register names for the current target. If no arguments are given, it shows a list of the names of all the registers. If integer numbers are given as arguments, it will print a list of the names of the registers corresponding to the arguments.
GDB does not have a command which corresponds to
`-data-list-register-names'. In gdbtk there is a
corresponding command `gdb_regnames'.
For the PPC MBX board:
(gdb)
-data-list-register-names
^done,register-names={"r0","r1","r2","r3","r4","r5","r6","r7",
"r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18",
"r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29",
"r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9",
"f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20",
"f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31",
"pc","ps","cr","lr","ctr","xer"}
(gdb)
-data-list-register-names 1 2 3
^done,register-names={"r1","r2","r3"}
(gdb)
-data-list-register-values Command-data-list-register-values fmt [ ( regno )*]
Display the registers' contents. fmt is the format according to which the registers' contents are to be returned, followed by an optional list of numbers specifying the registers to display. A missing list of numbers indicates that the contents of all the registers must be returned.
Allowed formats for fmt are:
x
o
t
d
r
N
The corresponding GDB commands are `info reg', `info all-reg',
and (in gdbtk) `gdb_fetch_registers'.
For a PPC MBX board (note: line breaks are for readability only, they don't appear in the actual output):
(gdb)
-data-list-register-values r 64 65
^done,register-values={{number="64",value="0xfe00a300"},
{number="65",value="0x00029002"}}
(gdb)
-data-list-register-values x
^done,register-values={{number="0",value="0xfe0043c8"},
{number="1",value="0x3fff88"},{number="2",value="0xfffffffe"},
{number="3",value="0x0"},{number="4",value="0xa"},
{number="5",value="0x3fff68"},{number="6",value="0x3fff58"},
{number="7",value="0xfe011e98"},{number="8",value="0x2"},
{number="9",value="0xfa202820"},{number="10",value="0xfa202808"},
{number="11",value="0x1"},{number="12",value="0x0"},
{number="13",value="0x4544"},{number="14",value="0xffdfffff"},
{number="15",value="0xffffffff"},{number="16",value="0xfffffeff"},
{number="17",value="0xefffffed"},{number="18",value="0xfffffffe"},
{number="19",value="0xffffffff"},{number="20",value="0xffffffff"},
{number="21",value="0xffffffff"},{number="22",value="0xfffffff7"},
{number="23",value="0xffffffff"},{number="24",value="0xffffffff"},
{number="25",value="0xffffffff"},{number="26",value="0xfffffffb"},
{number="27",value="0xffffffff"},{number="28",value="0xf7bfffff"},
{number="29",value="0x0"},{number="30",value="0xfe010000"},
{number="31",value="0x0"},{number="32",value="0x0"},
{number="33",value="0x0"},{number="34",value="0x0"},
{number="35",value="0x0"},{number="36",value="0x0"},
{number="37",value="0x0"},{number="38",value="0x0"},
{number="39",value="0x0"},{number="40",value="0x0"},
{number="41",value="0x0"},{number="42",value="0x0"},
{number="43",value="0x0"},{number="44",value="0x0"},
{number="45",value="0x0"},{number="46",value="0x0"},
{number="47",value="0x0"},{number="48",value="0x0"},
{number="49",value="0x0"},{number="50",value="0x0"},
{number="51",value="0x0"},{number="52",value="0x0"},
{number="53",value="0x0"},{number="54",value="0x0"},
{number="55",value="0x0"},{number="56",value="0x0"},
{number="57",value="0x0"},{number="58",value="0x0"},
{number="59",value="0x0"},{number="60",value="0x0"},
{number="61",value="0x0"},{number="62",value="0x0"},
{number="63",value="0x0"},{number="64",value="0xfe00a300"},
{number="65",value="0x29002"},{number="66",value="0x202f04b5"},
{number="67",value="0xfe0043b0"},{number="68",value="0xfe00b3e4"},
{number="69",value="0x20002b03"}}
(gdb)
-data-read-memory Command-data-read-memory [ -o byte-offset ] address word-format word-size nr-rows nr-cols [ aschar ]
where:
print command (see section Output formats).
This command displays memory contents as a table of nr-rows by
nr-cols words, each word being word-size bytes. In total,
nr-rows * nr-cols * word-size bytes are read
(returned as `total-bytes'). Should less then the requested number
of bytes be returned by the target, the missing words are identified
using `N/A'. The number of bytes read from the target is returned
in `nr-bytes' and the starting address used to read memory in
`addr'.
The address of the next/previous page or row is available in `next-row' and `prev-row', `next-page' and `prev-page'.
The corresponding GDB command is `x'. gdbtk has
`gdb_get_mem' memory read.
Read six bytes of memory starting at bytes+6 but then offset by
-6 bytes. Format as three rows of two columns. One byte per
word. Display each word in hex.
(gdb)
9-data-read-memory -o -6 -- bytes+6 x 1 3 2
9^done,addr="0x00001390",nr-bytes="6",total-bytes="6",
next-row="0x00001396",prev-row="0x0000138e",next-page="0x00001396",
prev-page="0x0000138a",memory={
{addr="0x00001390",data={"0x00","0x01"}},
{addr="0x00001392",data={"0x02","0x03"}},
{addr="0x00001394",data={"0x04","0x05"}}}
(gdb)
Read two bytes of memory starting at address shorts + 64 and
display as a single word formatted in decimal.
(gdb)
5-data-read-memory shorts+64 d 2 1 1
5^done,addr="0x00001510",nr-bytes="2",total-bytes="2",
next-row="0x00001512",prev-row="0x0000150e",
next-page="0x00001512",prev-page="0x0000150e",memory={
{addr="0x00001510",data={"128"}}}
(gdb)
Read thirty two bytes of memory starting at bytes+16 and format
as eight rows of four columns. Include a string encoding with x
used as the non-printable character.
(gdb)
4-data-read-memory bytes+16 x 1 8 4 x
4^done,addr="0x000013a0",nr-bytes="32",total-bytes="32",
next-row="0x000013c0",prev-row="0x0000139c",
next-page="0x000013c0",prev-page="0x00001380",memory={
{addr="0x000013a0",data={"0x10","0x11","0x12","0x13"},ascii="xxxx"},
{addr="0x000013a4",data={"0x14","0x15","0x16","0x17"},ascii="xxxx"},
{addr="0x000013a8",data={"0x18","0x19","0x1a","0x1b"},ascii="xxxx"},
{addr="0x000013ac",data={"0x1c","0x1d","0x1e","0x1f"},ascii="xxxx"},
{addr="0x000013b0",data={"0x20","0x21","0x22","0x23"},ascii=" !\"#"},
{addr="0x000013b4",data={"0x24","0x25","0x26","0x27"},ascii="$%&'"},
{addr="0x000013b8",data={"0x28","0x29","0x2a","0x2b"},ascii="()*+"},
{addr="0x000013bc",data={"0x2c","0x2d","0x2e","0x2f"},ascii=",-./"}}
(gdb)
-display-delete Command-display-delete number
Delete the display number.
The corresponding GDB command is `delete display'.
N.A.
-display-disable Command-display-disable number
Disable display number.
The corresponding GDB command is `disable display'.
N.A.
-display-enable Command-display-enable number
Enable display number.
The corresponding GDB command is `enable display'.
N.A.
-display-insert Command-display-insert expression
Display expression every time the program stops.
The corresponding GDB command is `display'.
N.A.
-display-list Command-display-list
List the displays. Do not show the current values.
The corresponding GDB command is `info display'.
N.A.
-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 pathdir
Add directory pathdir to beginning of search path for source files.
The corresponding GDB command is `dir'.
(gdb) -environment-directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb ^done (gdb)
-environment-path Command-environment-path ( pathdir )+
Add directories to beginning of search path for object files.
The corresponding GDB command is `path'.
(gdb) -environment-path /kwikemart/marge/ezannoni/flathead-dev/ppc-eabi/gdb ^done (gdb)
-environment-pwd Command-environment-pwd
Show the current working directory.
The corresponding GDB command is `pwd'.
(gdb) -environment-pwd ~Working directory /kwikemart/marge/ezannoni/flathead-dev/devo/gdb. ^done (gdb)
As a result of execution, the inferior program can run to completion, if it doesn't encouter any breakpoints. In this case the ouput will include an exit code, if the program has exited exceptionally.
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-abort Command-exec-abort
Kill the inferior running program.
The corresponding GDB command is `kill'.
N.A.
-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-continue Command-exec-continue
Asynchronous command. 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",line="13"}
(gdb)
-exec-finish Command-exec-finish
Asynchronous command. 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",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",line="14"},
gdb-result-var="$1",return-value="0"
(gdb)
-exec-interrupt Command-exec-interrupt
Asynchronous command. 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",line="13"}
(gdb)
(gdb)
-exec-interrupt
^error,msg="mi_cmd_exec_interrupt: Inferior not executing."
(gdb)
-exec-next Command-exec-next
Asynchronous command. 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
Asynchronous command. 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",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",line="18"}
(gdb)
-exec-run Command-exec-run
Asynchronous command. Starts execution of the inferior from the beginning. The inferior executes until either a breakpoint is encountered or the program exits.
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",line="4"}
(gdb)
-exec-show-arguments Command-exec-show-arguments
Print the arguments of the program.
The corresponding GDB command is `show args'.
N.A.
-exec-step Command-exec-step
Asynchronous command. 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",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
Asynchronous command. 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",line="10"}
(gdb)
-exec-step-instruction
^running
(gdb)
*stopped,reason="end-stepping-range",
frame={addr="0x000100f4",func="foo",args={},file="try.c",line="10"}
(gdb)
-exec-until Command-exec-until [ location ]
Asynchronous command. 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",line="6"}
(gdb)
-file-exec-and-symbols Command-file-exec-and-symbols file
Specify the executable file to be debugged. This file is the one from which the symbol table is also read. If no file is specified, the command clears the executable and symbol information. If breakpoints are set when using this command with no arguments, gdb will produce error messages. Otherwise, no output is produced, except a completion notification.
The corresponding GDB command is `file'.
(gdb) -file-exec-and-symbols /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb)
-file-exec-file Command-file-exec-file file
Specify the executable file to be debugged. Unlike `-file-exec-and-symbols', the symbol table is not read from this file. If used without argument, GDB clears the information about the executable file. No output is produced, except a completion notification.
The corresponding GDB command is `exec-file'.
(gdb) -file-exec-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb)
-file-list-exec-sections Command-file-list-exec-sections
List the sections of the current executable file.
The GDB command `info file' shows, among the rest, the same
information as this command. gdbtk has a corresponding command
`gdb_load_info'.
N.A.
-file-list-exec-source-files Command-file-list-exec-source-files
List the source files for the current executable.
There's no GDB command which directly corresponds to this one.
gdbtk has an analogous command `gdb_listfiles'.
N.A.
-file-list-shared-libraries Command-file-list-shared-libraries
List the shared libraries in the program.
The corresponding GDB command is `info shared'.
N.A.
-file-list-symbol-files Command-file-list-symbol-files
List symbol files.
The corresponding GDB command is `info file' (part of it).
N.A.
-file-symbol-file Command-file-symbol-file file
Read symbol table info from the specified file argument. When used without arguments, clears GDB's symbol table info. No output is produced, except for a completion notification.
The corresponding GDB command is `symbol-file'.
(gdb) -file-symbol-file /kwikemart/marge/ezannoni/TRUNK/mbx/hello.mbx ^done (gdb)
-gdb-exit Command-gdb-exit
Exit GDB immediately.
Approximately corresponds to `quit'.
(gdb) -gdb-exit
-gdb-set Command-gdb-set
Set an internal GDB variable.
The corresponding GDB command is `set'.
(gdb) -gdb-set $foo=3 ^done (gdb)
-gdb-show Command-gdb-show
Show the current value of a GDB variable.
The corresponding GDB command is `show'.
(gdb) -gdb-show annotate ^done,value="0" (gdb)
-gdb-version Command-gdb-version
Show version information for GDB. Used mostly in testing.
There's no equivalent GDB command. GDB by default shows this information when you start an interactive session.
(gdb) -gdb-version ~GNU gdb 5.2.1 ~Copyright 2000 Free Software Foundation, Inc. ~GDB is free software, covered by the GNU General Public License, and ~you are welcome to change it and/or distribute copies of it under ~ certain conditions. ~Type "show copying" to see the conditions. ~There is absolutely no warranty for GDB. Type "show warranty" for ~ details. ~This GDB was configured as "--host=sparc-sun-solaris2.5.1 --target=ppc-eabi". ^done (gdb)
-stack-info-frame Command-stack-info-frame
Get info on the current frame.
The corresponding GDB command is `info frame' or `frame' (without arguments).
N.A.
-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.
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",line="8"},
frame={level="1 ",addr="0x0001076c",func="callee3",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="17"},
frame={level="2 ",addr="0x0001078c",func="callee2",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="22"},
frame={level="3 ",addr="0x000107b4",func="callee1",
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",line="27"},
frame={level="4 ",addr="0x000107e0",func="main",
file="../../../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.
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",line="11"},
frame={level="1 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="2 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="3 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="4 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="5 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="6 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="7 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="8 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="9 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="10",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="11",addr="0x00010738",func="main",
file="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",line="14"},
frame={level="4 ",addr="0x000107a4",func="foo",
file="recursive2.c",line="14"},
frame={level="5 ",addr="0x000107a4",func="foo",
file="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",line="14"}}
(gdb)
-stack-list-locals Command-stack-list-locals print-values
Display the local variable names for the current frame. With an argument of 0 prints only the names of the variables, with argument of 1 prints also their values.
`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 1
^done,locals={{name="A",value="1"},{name="B",value="2"},
{name="C",value="3"}}
(gdb)
-stack-select-frame Command-stack-select-frame framenum
Change the current 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)
-symbol-info-address Command-symbol-info-address symbol
Describe where symbol is stored.
The corresponding GDB command is `info address'.
N.A.
-symbol-info-file Command-symbol-info-file
Show the file for the symbol.
There's no equivalent GDB command. gdbtk has
`gdb_filnd_file'.
N.A.
-symbol-info-function Command-symbol-info-function
Show which function the symbol lives in.
`gdb_get_function' in gdbtk.
N.A.
-symbol-info-line Command-symbol-info-line
Show the core addresses of the code for a source line.
The corresponding GDB comamnd is `info line'. gdbtk has the
`gdb_get_line' `gdb_get_file' commands.
N.A.
-symbol-info-symbol Command-symbol-info-symbol addr
Describe what symbol is at location addr.
The corresponding GDB command is `info symbol'.
N.A.
-symbol-list-functions Command-symbol-list-functions
List the functions in the executable.
`info functions' in GDB, `gdb_listfunc' `gdb_search' in
gdbtk.
N.A.
-symbol-list-types Command-symbol-list-types
List all the type names.
The corresponding commands are `info types' in GDB,
`gdb_search' in gdbtk.
N.A.
-symbol-list-variables Command-symbol-list-variables
List all the global and static variable names.
`info variables' in GDB, `gdb_search' in gdbtk.
N.A.
-symbol-locate Command-symbol-locate
`gdb_loc' in gdbtk.
N.A.
-symbol-type Command-symbol-type variable
Show type of variable.
The corresponding GDB command is `ptype', gdbtk has
`gdb_obj_variable'.
N.A.
-target-attach Command-target-attach pid | file
Attach to a process pid or a file file outside of GDB.
The corresponding GDB command is `attach'.
N.A.
-target-compare-sections Command-target-compare-sections [ section ]
Compare data of section section on target to the exec file. Without the argument, all sections are compared.
The GDB equivalent is `compare-sections'.
N.A.
-target-detach Command-target-detach
Disconnect from the remote target. There's no output.
The corresponding GDB command is `detach'.
(gdb) -target-detach ^done (gdb)
-target-download Command-target-download
Loads the executable onto the remote target. It prints out an update message every half second, which includes the fields:
Each message is sent as status record (see section GDB/MI Output Syntax).
In addition, it prints the name and size of the sections, as they are downloaded. These messages include the following fields:
At the end, a summary is printed.
The corresponding GDB command is `load'.
Note: each status message appears on a single line. Here the messages have been broken down so that they can fit onto a page.
(gdb)
-target-download
+download,{section=".text",section-size="6668",total-size="9880"}
+download,{section=".text",section-sent="512",section-size="6668",
total-sent="512",total-size="9880"}
+download,{section=".text",section-sent="1024",section-size="6668",
total-sent="1024",total-size="9880"}
+download,{section=".text",section-sent="1536",section-size="6668",
total-sent="1536",total-size="9880"}
+download,{section=".text",section-sent="2048",section-size="6668",
total-sent="2048",total-size="9880"}
+download,{section=".text",section-sent="2560",section-size="6668",
total-sent="2560",total-size="9880"}
+download,{section=".text",section-sent="3072",section-size="6668",
total-sent="3072",total-size="9880"}
+download,{section=".text",section-sent="3584",section-size="6668",
total-sent="3584",total-size="9880"}
+download,{section=".text",section-sent="4096",section-size="6668",
total-sent="4096",total-size="9880"}
+download,{section=".text",section-sent="4608",section-size="6668",
total-sent="4608",total-size="9880"}
+download,{section=".text",section-sent="5120",section-size="6668",
total-sent="5120",total-size="9880"}
+download,{section=".text",section-sent="5632",section-size="6668",
total-sent="5632",total-size="9880"}
+download,{section=".text",section-sent="6144",section-size="6668",
total-sent="6144",total-size="9880"}
+download,{section=".text",section-sent="6656",section-size="6668",
total-sent="6656",total-size="9880"}
+download,{section=".init",section-size="28",total-size="9880"}
+download,{section=".fini",section-size="28",total-size="9880"}
+download,{section=".data",section-size="3156",total-size="9880"}
+download,{section=".data",section-sent="512",section-size="3156",
total-sent="7236",total-size="9880"}
+download,{section=".data",section-sent="1024",section-size="3156",
total-sent="7748",total-size="9880"}
+download,{section=".data",section-sent="1536",section-size="3156",
total-sent="8260",total-size="9880"}
+download,{section=".data",section-sent="2048",section-size="3156",
total-sent="8772",total-size="9880"}
+download,{section=".data",section-sent="2560",section-size="3156",
total-sent="9284",total-size="9880"}
+download,{section=".data",section-sent="3072",section-size="3156",
total-sent="9796",total-size="9880"}
^done,address="0x10004",load-size="9880",transfer-rate="6586",
write-rate="429"
(gdb)
-target-exec-status Command-target-exec-status
Provide information on the state of the target (whether it is running or not, for instance).
There's no equivalent GDB command.
N.A.
-target-list-available-targets Command-target-list-available-targets
List the possible targets to connect to.
The corresponding GDB command is `help target'.
N.A.
-target-list-current-targets Command-target-list-current-targets
Describe the current target.
The corresponding information is printed by `info file' (among other things).
N.A.
-target-list-parameters Command-target-list-parameters
No equivalent.
N.A.
-target-select Command-target-select type parameters ...
Connect GDB to the remote target. This command takes two args:
The output is a connection notification, followed by the address at which the target program is, in the following form:
^connected,addr="address",func="function name",
args={arg list}
The corresponding GDB command is `target'.
(gdb)
-target-select async /dev/ttya
^connected,addr="0xfe00a300",func="??",args={}
(gdb)
-thread-info Command-thread-info
No equivalent.
N.A.
-thread-list-all-threads Command-thread-list-all-threads
The equivalent GDB command is `info threads'.
N.A.
-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)
The tracepoint commands are not yet implemented.
For the implementation of a variable debugger window (locals, watched
expressions, etc.), we are proposing the adaptation of the existing code
used by Insight.
The two main reasons for that are:
The original interface was designed to be used by Tcl code, so it was slightly changed so it could be used through flathead. This document describes the flathead operations that will be available and gives some hints about their use.
Note: In addition to the set of operations described here, we expect the GUI implementation of a variable window to require, at least, the following operations:
The basic idea behind variable objects is the creation of a named object to represent a variable, an expression, a memory location or even a CPU register. For each object created, a set of operations is available for examining or changing its properties.
Furthermore, complex data types, such as C structures, are represented
in a tree format. For instance, the struct type variable is the
root and the children will represent the struct members. If a child
is itself of a complex type, it will also have children of its own.
Appropriate language differences are handled for C, C++ and Java.
When returning the actual values of the objects, this facility allows
for the individual selection of the display format used in the result
creation. It can be chosen among: binary, decimal, hexadecimal, octal
and natural. Natural refers to a default format automatically
chosen based on the variable type (like decimal for an int, hex
for pointers, etc.).
The following is the complete set of flathead operations defined to access this functionality:
| Operation | Description |
| -var-create | create a variable object |
| -var-delete | delete the variable object and 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 what 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 |
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 name
Deletes a previously created variable object and all of its 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}
-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 name
Returns a list of the children of the specified variable object:
numchild=n,children={{name=name,
numchild=n,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 what is represented by the variable object name:
lang=lang-spec,exp=expression
where lang-spec is {"C" | "C++" | "Java"}.
-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 in the current format specified for the object:
value=value
-var-assign Command-var-assign name expression
Assigns the value of expression to the variable object specified by name. The object must be "editable".
-var-update Command
-var-update {name | "*"}
Update the value of the variable object name by evaluating its expression after fetching all the new values from memory or registers. A `*' causes all existing variable objects to be updated.
One problem identified in the existing GDB/MI output syntax was the difficulty in differentiating between a tuple such as:
{number="1",type="breakpoint",disp="keep",enabled="y"}
where each value has a unique label, and a list such as:
{"1","2","4"}
{bp="1",bp="2",bp="4"}
where values are un-labeled or the label is duplicated.
What follows is a draft revision to the output specification that addresses this problem.
The output from GDB/MI consists of zero or more out-of-band records optionally followed by a single result record, the result record being for the most recent command input. The sequence is terminated by "(gdb)".
Asynchronous GDB/MI output is similar.
Each output record directly associated with an input command is prefixed
by the input commands token.
output ==>
[ result-record ] "(gdb)" nl
result-record ==>
[ token ] "^" result-class { "," result } nl
out-of-band-record ==>
| stream-record
async-record ==>
| 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 ==>
result-class ==>
| "running" | "connected" | "error" | "exit"
async-class ==>
| others depending on need as still in development
result ==>
value ==>
| tupple | list
tupple ==>
| "{" result { "," result } "}"
list ==>
[]" | "[" value { "," value } "]"
string ==>
c-string ==>
stream-record ==>
| target-stream-output | log-stream-output
console-stream-output ==>
target-stream-output ==>
log-stream-output ==>
nl ==>
| CR-LF
token ==>
In addition, the following are still being developed.
query
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.
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