24.10 GDB/MI Program Execution

These are the asynchronous commands which generate the out-of-band record ‘*stopped’. Currently No value for GDBN only really executes asynchronously with remote targets and this interaction is mimicked in other cases.

The -exec-continue Command

Synopsis

 -exec-continue

Resumes the execution of the inferior program until a breakpoint is encountered, or until the inferior exits.

No value for GDBN Command

The corresponding No value for GDBN corresponding is ‘continue’.

Example

-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)

The -exec-finish Command

Synopsis

 -exec-finish

Resumes the execution of the inferior program until the current function is exited. Displays the results returned by the function.

No value for GDBN Command

The corresponding No value for GDBN command is ‘finish’.

Example

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 No value for GDBN 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)

The -exec-interrupt Command

Synopsis

 -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.

No value for GDBN Command

The corresponding No value for GDBN command is ‘interrupt’.

Example

(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)

The -exec-next Command

Synopsis

 -exec-next

Resumes execution of the inferior program, stopping when the beginning of the next source line is reached.

No value for GDBN Command

The corresponding No value for GDBN command is ‘next’.

Example

-exec-next
^running
(gdb)
*stopped,reason="end-stepping-range",line="8",file="hello.c"
(gdb)

The -exec-next-instruction Command

Synopsis

 -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.

No value for GDBN Command

The corresponding No value for GDBN command is ‘nexti’.

Example

(gdb)
-exec-next-instruction
^running

(gdb)
*stopped,reason="end-stepping-range",
addr="0x000100d4",line="5",file="hello.c"
(gdb)

The -exec-return Command

Synopsis

 -exec-return

Makes current function return immediately. Doesn't execute the inferior. Displays the new current frame.

No value for GDBN Command

The corresponding No value for GDBN command is ‘return’.

Example

(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)

The -exec-run Command

Synopsis

 -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.

No value for GDBN Command

The corresponding No value for GDBN command is ‘run’.

Examples

(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"

The -exec-step Command

Synopsis

 -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.

No value for GDBN Command

The corresponding No value for GDBN command is ‘step’.

Example

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)

The -exec-step-instruction Command

Synopsis

 -exec-step-instruction

Resumes the inferior which executes one machine instruction. The output, once No value for GDBN 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.

No value for GDBN Command

The corresponding No value for GDBN command is ‘stepi’.

Example

(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)

The -exec-until Command

Synopsis

 -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’.

No value for GDBN Command

The corresponding No value for GDBN command is ‘until’.

Example

(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)