Re: RFC: next/finish/etc -vs- exceptions

Tom Tromey
2010-12-10T20:07:11Z

>>>>> "Jan" == Jan Kratochvil <jan.kratochvil@redhat.com> writes:

Jan> The new field `tp->control.exception_resume_breakpoint' should be
Jan> probably handled by existing save_infcall_control_state,
Jan> restore_infcall_control_state and discard_infcall_control_state
Jan> somehow like step_resume_breakpoint is.

Thanks for the test case.

Here is what I am testing.

It just mirrors the existing step_resume_breakpoint code.
I think that this is the right thing to do -- stash any
exception-related breakpoint while doing the infcall, then restore it
if the infcall succeeds.

Tom

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 1bc00a4..f72a18d 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -6379,6 +6379,7 @@ save_infcall_control_state (void)
inf_status->inferior_control = inf->control;

tp->control.step_resume_breakpoint = NULL;
+ tp->control.exception_resume_breakpoint = NULL;

/* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
chain. If caller's caller is walking the chain, they'll be happier if we
@@ -6428,6 +6429,10 @@ restore_infcall_control_state (struct infcall_control_state *inf_status)
if (tp->control.step_resume_breakpoint)
tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;

+ if (tp->control.exception_resume_breakpoint)
+ tp->control.exception_resume_breakpoint->disposition
+ = disp_del_at_next_stop;
+
/* Handle the bpstat_copy of the chain. */
bpstat_clear (&tp->control.stop_bpstat);

@@ -6476,6 +6481,10 @@ discard_infcall_control_state (struct infcall_control_state *inf_status)
inf_status->thread_control.step_resume_breakpoint->disposition
= disp_del_at_next_stop;

+ if (inf_status->thread_control.exception_resume_breakpoint)
+ inf_status->thread_control.exception_resume_breakpoint->disposition
+ = disp_del_at_next_stop;
+
/* See save_infcall_control_state for info on stop_bpstat. */
bpstat_clear (&inf_status->thread_control.stop_bpstat);

diff --git a/gdb/testsuite/gdb.cp/nextoverthrow.cc b/gdb/testsuite/gdb.cp/nextoverthrow.cc
index b25cb34..c3da516 100644
--- a/gdb/testsuite/gdb.cp/nextoverthrow.cc
+++ b/gdb/testsuite/gdb.cp/nextoverthrow.cc
@@ -19,8 +19,9 @@

using namespace std;

-void dummy ()
+int dummy ()
{
+ return 0;
}

class NextOverThrowDerivates
@@ -89,6 +90,18 @@ public:
function1 (val); // until here
}

+ void resumebpt (int val)
+ {
+ try
+ {
+ throw val;
+ }
+ catch (int x)
+ {
+ dummy ();
+ }
+ }
+
};
NextOverThrowDerivates next_cases;

@@ -198,6 +211,18 @@ int main ()
testval = val; // End: advance
}

+ // Test of "resumebpt".
+ try
+ {
+ next_cases.resumebpt (10); // Start: resumebpt
+ next_cases.resumebpt (11); // Second: resumebpt
+ }
+ catch (int val)
+ {
+ dummy ();
+ testval = val; // End: resumebpt
+ }
+
testval = 32; // done
}

diff --git a/gdb/testsuite/gdb.cp/nextoverthrow.exp b/gdb/testsuite/gdb.cp/nextoverthrow.exp
index 960ea0d..c19674f 100644
--- a/gdb/testsuite/gdb.cp/nextoverthrow.exp
+++ b/gdb/testsuite/gdb.cp/nextoverthrow.exp
@@ -149,5 +149,14 @@ gdb_test "advance $line" ".*" "advance-over-throw"
tbreak_and_cont "End: advance"
verify_testval "pre-check - advance" 8

+tbreak_and_cont "Start: resumebpt"
+gdb_test "tbreak _Unwind_RaiseException"
+gdb_test "continue" "Temporary breakpoint.*" "continuing to _Unwind_RaiseException"
+gdb_test "finish" "Run till exit .*"
+gdb_test {set $retpc=$pc}
+gdb_test {break *$retpc if dummy ()}
+tbreak_and_cont "Second: resumebpt"
+gdb_test "next"
+
tbreak_and_cont "done"
verify_testval "post-check - advance" 9