Part of PR gdb/13860 is about the mi-solib.exp test's output being
different in sync vs async modes.
sync:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async off" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17724"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",frame={addr="0x000000379180f990",func="_dl_debug_state",args=[],from="/lib64/ld-linux-x86-64.so.2"},thread-id="1",stopped-threads="all",core="3"
(gdb)
async:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async on" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
start
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17729"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
(gdb)
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="1"
For now, let's focus only on the *stopped event. We see that the
async output is missing frame info. And this causes a test failure in
async mode, as "mi_expect_stop solib-event" wants to see the frame
info.
However, if we compare the event output when a real MI execution
command is used, compared to a CLI command (e.g., run vs -exec-run,
next vs -exec-next, etc.), we see:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async off" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
r
&"r\n"
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17751"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",frame={addr="0x000000379180f990",func="_dl_debug_state",args=[],from="/lib64/ld-linux-x86-64.so.2"},thread-id="1",stopped-threads="all",core="3"
(gdb)
-exec-run
=thread-exited,id="1",group-id="i1"
=thread-group-exited,id="i1"
=library-unloaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",thread-group="i1"
=thread-group-started,id="i1",pid="17754"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="1"
=thread-selected,id="1"
(gdb)
As seen above, with MI commands, the *stopped event _doesn't_ have
frame info. This is because normal_stop, as commanded by the result
of bpstat_print, skips printing frame info in this case (it's an
"event", not a "breakpoint"), and when the interpreter is MI,
mi_on_normal_stop skips calling print_stack_frame, as the normal_stop
call was already done with the MI uiout. This explains why the async
output is different even with a CLI command. Its because in async
mode, the mi_on_normal_stop path is always taken; it is always reached
with the MI uiout, because the stop is handled from the event loop,
instead of from within `proceed -> wait_for_inferior -> normal_stop'
with the interpreter overridden, as in sync mode.
This patch fixes the issue by making all cases output the same
*stopped event, by factoring out the print code from normal_stop, and
using it from mi_on_normal_stop as well. I chose the *stopped output
without a frame, mainly because that is what you already get if you
use MI execution commands, the commands frontends are supposed to use
(except when implementing a console). This patch makes it simpler to
tweak the MI output differently if desired, as we only have to change
the centralized print_stop_event (taking into account whether the
uiout is MI-like), and all different modes will change accordingly.
Tested on x86_64 Fedora 17, no regressions. The mi-solib.exp test no
longer fails in async mode with this patch, so the patch removes the
kfail.
2014-03-18 Pedro Alves <palves@redhat.com>
PR gdb/13860
* inferior.h (print_stop_event): Declare.
* infrun.c (print_stop_event): New, factored out from ...
(normal_stop): ... this.
* mi/mi-interp.c (mi_on_normal_stop): Use print_stop_event instead
of bpstat_print/print_stack_frame.
2014-03-18 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdb.mi/mi-solib.exp: Remove gdb/13860 kfail.
* lib/mi-support.exp (mi_expect_stop): Add special handling for
solib-event.
0c7e1a4602