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[rfc, spu] Don't call set_gdbarch_cannot_step_breakpoint in spu_gdbarch_init
- From: Yao Qi <qiyaoltc at gmail dot com>
- To: gdb-patches at sourceware dot org
- Date: Tue, 17 Mar 2015 14:52:02 +0000
- Subject: [rfc, spu] Don't call set_gdbarch_cannot_step_breakpoint in spu_gdbarch_init
- Authentication-results: sourceware.org; auth=none
From: Yao Qi <yao.qi@linaro.org>
Nowadays, in infrun.c:resume, the setting to 'step' variable is like:
if (use_displaced_stepping (gdbarch)
&& tp->control.trap_expected
&& sig == GDB_SIGNAL_0
&& !current_inferior ()->waiting_for_vfork_done)
{
}
/* Do we need to do it the hard way, w/temp breakpoints? */
else if (step)
step = maybe_software_singlestep (gdbarch, pc); <-- [1]
...
if (execution_direction != EXEC_REVERSE
&& step && breakpoint_inserted_here_p (aspace, pc))
{
...
if (gdbarch_cannot_step_breakpoint (gdbarch)) <-- [2]
step = 0;
}
spu doesn't have displaced stepping and uses software single step,
so 'step' is set to zero in [1], and [2] becomes unreachable as a
result. So don't have to call set_gdbarch_cannot_step_breakpoint
in spu_gdbarch_init.
On the other hand, we either have hardware single step or software
single step, do we still need gdbarch method cannot_step_breakpoint?
CANNOT_STEP_BREAKPOINT was introduced in 1993 by commit
cef4c2e7a5f2d3426a8255f74b6c7f4e795fd9a4 for alpha OSF/1 native
support.
I don't have spu machine to test this patch.
gdb:
2015-03-17 Yao Qi <yao.qi@linaro.org>
* spu-tdep.c (spu_gdbarch_init): Don't call
set_gdbarch_cannot_step_breakpoint.
---
gdb/spu-tdep.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/gdb/spu-tdep.c b/gdb/spu-tdep.c
index 36ad312..870cf32 100644
--- a/gdb/spu-tdep.c
+++ b/gdb/spu-tdep.c
@@ -2794,7 +2794,6 @@ spu_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
set_gdbarch_decr_pc_after_break (gdbarch, 4);
set_gdbarch_breakpoint_from_pc (gdbarch, spu_breakpoint_from_pc);
set_gdbarch_memory_remove_breakpoint (gdbarch, spu_memory_remove_breakpoint);
- set_gdbarch_cannot_step_breakpoint (gdbarch, 1);
set_gdbarch_software_single_step (gdbarch, spu_software_single_step);
set_gdbarch_get_longjmp_target (gdbarch, spu_get_longjmp_target);
--
1.9.1