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authorMichael Snyder <msnyder@vmware.com>2001-06-28 21:34:03 +0000
committerMichael Snyder <msnyder@vmware.com>2001-06-28 21:34:03 +0000
commit80b34fabd3043272bd132a1479fcbd81d761b16a (patch)
treef63f9bea8a7a0bbfdcf141483f191afd3d41e8c2 /gdb
parent1456ad8e67b1dd1b2e46fbc6e926bd312330ea24 (diff)
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2001-06-28 Michael Snyder <msnyder@redhat.com>
* infrun.c (handle_inferior_event): Replace prev_pc test in all calls to bpstat_stop_status (removed in 1999-09-24). This test helps distinguish stepping over a breakpoint trap from stepping thru a jump to the instruction after a breakpoint trap. (handle_inferior_event): Don't bother writing the PC if DECR_PC_AFTER_BREAK is zero (optimization). * breakpoint.c (bpstat_stop_status): Add comment explaining the purpose and usage of the "not_a_breakpoint" argument in computing the breakpoint address.
Diffstat (limited to 'gdb')
-rw-r--r--gdb/ChangeLog12
-rw-r--r--gdb/breakpoint.c7
-rw-r--r--gdb/infrun.c55
3 files changed, 67 insertions, 7 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ae7934a..22de499 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,15 @@
+2001-06-28 Michael Snyder <msnyder@redhat.com>
+
+ * infrun.c (handle_inferior_event): Replace prev_pc test in all
+ calls to bpstat_stop_status (removed in 1999-09-24). This test
+ helps distinguish stepping over a breakpoint trap from stepping
+ thru a jump to the instruction after a breakpoint trap.
+ (handle_inferior_event): Don't bother writing the PC if
+ DECR_PC_AFTER_BREAK is zero (optimization).
+ * breakpoint.c (bpstat_stop_status): Add comment explaining the
+ purpose and usage of the "not_a_breakpoint" argument in computing
+ the breakpoint address.
+
2001-06-28 Andrew Cagney <ac131313@redhat.com>
From 2000-12-03 Stephane Carrez <Stephane.Carrez@worldnet.fr>:
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 20f7251..cee302e 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -2409,7 +2409,12 @@ bpstat_stop_status (CORE_ADDR *pc, int not_a_breakpoint)
"Error evaluating expression for watchpoint %d\n";
char message[sizeof (message1) + 30 /* slop */ ];
- /* Get the address where the breakpoint would have been. */
+ /* Get the address where the breakpoint would have been.
+ The "not_a_breakpoint" argument is meant to distinguish
+ between a breakpoint trap event and a trace/singlestep
+ trap event. For a trace/singlestep trap event, we would
+ not want to subtract DECR_PC_AFTER_BREAK from the PC. */
+
bp_addr = *pc - (not_a_breakpoint && !SOFTWARE_SINGLE_STEP_P () ?
0 : DECR_PC_AFTER_BREAK);
diff --git a/gdb/infrun.c b/gdb/infrun.c
index a500e97..972b093 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -1617,7 +1617,17 @@ handle_inferior_event (struct execution_control_state *ecs)
stop_pc = read_pc_pid (ecs->ptid);
ecs->saved_inferior_ptid = inferior_ptid;
inferior_ptid = ecs->ptid;
- stop_bpstat = bpstat_stop_status (&stop_pc, currently_stepping (ecs));
+ /* The second argument of bpstat_stop_status is meant to help
+ distinguish between a breakpoint trap and a singlestep trap.
+ This is only important on targets where DECR_PC_AFTER_BREAK
+ is non-zero. The prev_pc test is meant to distinguish between
+ singlestepping a trap instruction, and singlestepping thru a
+ jump to the instruction following a trap instruction. */
+
+ stop_bpstat = bpstat_stop_status (&stop_pc,
+ currently_stepping (ecs) &&
+ prev_pc !=
+ stop_pc - DECR_PC_AFTER_BREAK);
ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
inferior_ptid = ecs->saved_inferior_ptid;
goto process_event_stop_test;
@@ -1666,7 +1676,17 @@ handle_inferior_event (struct execution_control_state *ecs)
}
stop_pc = read_pc ();
- stop_bpstat = bpstat_stop_status (&stop_pc, currently_stepping (ecs));
+ /* The second argument of bpstat_stop_status is meant to help
+ distinguish between a breakpoint trap and a singlestep trap.
+ This is only important on targets where DECR_PC_AFTER_BREAK
+ is non-zero. The prev_pc test is meant to distinguish between
+ singlestepping a trap instruction, and singlestepping thru a
+ jump to the instruction following a trap instruction. */
+
+ stop_bpstat = bpstat_stop_status (&stop_pc,
+ currently_stepping (ecs) &&
+ prev_pc !=
+ stop_pc - DECR_PC_AFTER_BREAK);
ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
goto process_event_stop_test;
@@ -1731,7 +1751,17 @@ handle_inferior_event (struct execution_control_state *ecs)
stop_pc = read_pc_pid (ecs->ptid);
ecs->saved_inferior_ptid = inferior_ptid;
inferior_ptid = ecs->ptid;
- stop_bpstat = bpstat_stop_status (&stop_pc, currently_stepping (ecs));
+ /* The second argument of bpstat_stop_status is meant to help
+ distinguish between a breakpoint trap and a singlestep trap.
+ This is only important on targets where DECR_PC_AFTER_BREAK
+ is non-zero. The prev_pc test is meant to distinguish between
+ singlestepping a trap instruction, and singlestepping thru a
+ jump to the instruction following a trap instruction. */
+
+ stop_bpstat = bpstat_stop_status (&stop_pc,
+ currently_stepping (ecs) &&
+ prev_pc !=
+ stop_pc - DECR_PC_AFTER_BREAK);
ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
inferior_ptid = ecs->saved_inferior_ptid;
goto process_event_stop_test;
@@ -1840,7 +1870,8 @@ handle_inferior_event (struct execution_control_state *ecs)
/* Saw a breakpoint, but it was hit by the wrong thread.
Just continue. */
- write_pc_pid (stop_pc - DECR_PC_AFTER_BREAK, ecs->ptid);
+ if (DECR_PC_AFTER_BREAK)
+ write_pc_pid (stop_pc - DECR_PC_AFTER_BREAK, ecs->ptid);
remove_status = remove_breakpoints ();
/* Did we fail to remove breakpoints? If so, try
@@ -1852,7 +1883,9 @@ handle_inferior_event (struct execution_control_state *ecs)
then either :-) or execs. */
if (remove_status != 0)
{
- write_pc_pid (stop_pc - DECR_PC_AFTER_BREAK + 4, ecs->ptid);
+ /* FIXME! This is obviously non-portable! */
+ write_pc_pid (stop_pc - DECR_PC_AFTER_BREAK + 4,
+ ecs->ptid);
/* We need to restart all the threads now,
* unles we're running in scheduler-locked mode.
* Use currently_stepping to determine whether to
@@ -2016,7 +2049,8 @@ handle_inferior_event (struct execution_control_state *ecs)
includes evaluating watchpoints, things will come to a
stop in the correct manner. */
- write_pc (stop_pc - DECR_PC_AFTER_BREAK);
+ if (DECR_PC_AFTER_BREAK)
+ write_pc (stop_pc - DECR_PC_AFTER_BREAK);
remove_breakpoints ();
registers_changed ();
@@ -2097,6 +2131,14 @@ handle_inferior_event (struct execution_control_state *ecs)
else
{
/* See if there is a breakpoint at the current PC. */
+
+ /* The second argument of bpstat_stop_status is meant to help
+ distinguish between a breakpoint trap and a singlestep trap.
+ This is only important on targets where DECR_PC_AFTER_BREAK
+ is non-zero. The prev_pc test is meant to distinguish between
+ singlestepping a trap instruction, and singlestepping thru a
+ jump to the instruction following a trap instruction. */
+
stop_bpstat = bpstat_stop_status
(&stop_pc,
/* Pass TRUE if our reason for stopping is something other
@@ -2106,6 +2148,7 @@ handle_inferior_event (struct execution_control_state *ecs)
sigtramp, which is detected by a new stack pointer value
below any usual function calling stack adjustments. */
(currently_stepping (ecs)
+ && prev_pc != stop_pc - DECR_PC_AFTER_BREAK
&& !(step_range_end
&& INNER_THAN (read_sp (), (step_sp - 16))))
);