[RFC] infrun.c: Fix infinite loop caused by breakpoint adjustment

Kevin Buettner
2003-12-18T19:54:08Z

Any comments on the patch below?

It fixes an infinite loop caused by attempting to run to a location
to which it's architecturally impossible to set a breakpoint at. (It's
quite easy to reproduce this problem on FR-V. Just step into some
library code which has been compiled with optimization.)

Since it touches infrun.c, and since a lot of developers are on
holiday at this time of year, I'll wait until January 15 to commit it.
Hopefully, that'll give everyone who'd like to comment on this patch
a chance to look at it.

Kevin

* infrun.c (step_into_function): Account for possible breakpoint
adjustment when computing ``stop_func_start''.

Index: infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.122
diff -u -p -r1.122 infrun.c
--- infrun.c 25 Nov 2003 16:01:36 -0000 1.122
+++ infrun.c 18 Dec 2003 19:34:53 -0000
@@ -2762,6 +2762,18 @@ step_into_function (struct execution_con
&& ecs->sal.end < ecs->stop_func_end)
ecs->stop_func_start = ecs->sal.end;

+ /* Architectures which require breakpoint adjustment might not be able
+ to place a breakpoint at the computed address. If so, the test
+ ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
+ ecs->stop_func_start to an address at which a breakpoint may be
+ legitimately placed. */
+ if (gdbarch_adjust_breakpoint_address_p (current_gdbarch))
+ {
+ ecs->stop_func_start
+ = gdbarch_adjust_breakpoint_address (current_gdbarch,
+ ecs->stop_func_start);
+ }
+
if (ecs->stop_func_start == stop_pc)
{
/* We are already there: stop now. */