27.11 gdb/mi Program Execution

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.

The -exec-continue Command

Synopsis
      -exec-continue [--reverse] [--all|--thread-group N]

Resumes the execution of the inferior program, which will continue to execute until it reaches a debugger stop event. If the --reverse option is specified, execution resumes in reverse until it reaches a stop event. Stop events may include

In all-stop mode (see All-Stop Mode), may resume only one thread, or all threads, depending on the value of the scheduler-locking variable. If --all is specified, all threads (in all inferiors) will be resumed. The --all option is ignored in all-stop mode. If the --thread-group options is specified, then all threads in that thread group are resumed.
gdb Command

The corresponding gdb corresponding is continue.

Example
     -exec-continue
     ^running
     (gdb)
     @Hello world
     *stopped,reason="breakpoint-hit",disp="keep",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 [--reverse]

Resumes the execution of the inferior program until the current function is exited. Displays the results returned by the function. If the --reverse option is specified, resumes the reverse execution of the inferior program until the point where current function was called.

gdb Command

The corresponding gdb 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 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)

The -exec-interrupt Command

Synopsis
      -exec-interrupt [--all|--thread-group N]

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.

Note that when asynchronous execution is enabled, this command is asynchronous just like other execution commands. That is, first the ^done response will be printed, and the target stop will be reported after that using the *stopped notification.

In non-stop mode, only the context thread is interrupted by default. All threads (in all inferiors) will be interrupted if the --all option is specified. If the --thread-group option is specified, all threads in that group will be interrupted.

gdb Command

The corresponding gdb 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-jump Command

Synopsis
      -exec-jump location

Resumes execution of the inferior program at the location specified by parameter. See Specify Location, for a description of the different forms of location.

gdb Command

The corresponding gdb command is jump.

Example
     -exec-jump foo.c:10
     *running,thread-id="all"
     ^running

The -exec-next Command

Synopsis
      -exec-next [--reverse]

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

If the --reverse option is specified, resumes reverse execution of the inferior program, stopping at the beginning of the previous source line. If you issue this command on the first line of a function, it will take you back to the caller of that function, to the source line where the function was called.

gdb Command

The corresponding gdb 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 [--reverse]

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.

If the --reverse option is specified, resumes reverse execution of the inferior program, stopping at the previous instruction. If the previously executed instruction was a return from another function, it will continue to execute in reverse until the call to that function (from the current stack frame) is reached.

gdb Command

The corresponding gdb 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.

gdb Command

The corresponding gdb 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",disp="keep",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 [--all | --thread-group N]

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.

When no option is specified, the current inferior is started. If the --thread-group option is specified, it should refer to a thread group of type process, and that thread group will be started. If the --all option is specified, then all inferiors will be started.

gdb Command

The corresponding gdb 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",disp="keep",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 [--reverse]

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. If the --reverse option is specified, resumes reverse execution of the inferior program, stopping at the beginning of the previously executed source line.

gdb Command

The corresponding gdb 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 [--reverse]

Resumes the inferior which executes one machine instruction. If the --reverse option is specified, resumes reverse execution of the inferior program, stopping at the previously executed 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.

gdb Command

The corresponding gdb 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.

gdb Command

The corresponding gdb 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)