[PATCH v2] Fix hardware watchpoints in replay mode

[Hannes Domani <ssbssa@yahoo.de>]

Changes introduced by commit 9e8915c6cee5c37637521b424d723e990e06d597
caused a regression that meant hardware watchpoint stops would not
trigger in reverse execution or replay mode.  This was documented in
PR breakpoints/21969.
The problem is that record_check_stopped_by_breakpoint always overwrites
record_full_stop_reason, thus loosing the TARGET_STOPPED_BY_WATCHPOINT
value which would be checked afterwards.

This commit fixes that by checking if record_full_stop_reason is
TARGET_STOPPED_BY_BREAKPOINT and, if so, not overriding it.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21969
---
 gdb/record-full.c                           | 4 +++-
 gdb/testsuite/gdb.reverse/watch-reverse.exp | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/gdb/record-full.c b/gdb/record-full.c
index faf8b595d22..da785ef4b2a 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -1382,7 +1382,9 @@ record_full_wait_1 (struct target_ops *ops,
 
 		      /* check breakpoint */
 		      tmp_pc = regcache_read_pc (regcache);
-		      if (record_check_stopped_by_breakpoint
+		      if (record_full_stop_reason
+			  != TARGET_STOPPED_BY_WATCHPOINT
+			  && record_check_stopped_by_breakpoint
 			  (aspace, tmp_pc, &record_full_stop_reason))
 			{
 			  if (record_debug)
diff --git a/gdb/testsuite/gdb.reverse/watch-reverse.exp b/gdb/testsuite/gdb.reverse/watch-reverse.exp
index 6b81a6fdf88..a7126ac9b1d 100644
--- a/gdb/testsuite/gdb.reverse/watch-reverse.exp
+++ b/gdb/testsuite/gdb.reverse/watch-reverse.exp
@@ -118,8 +118,12 @@ gdb_test "continue" \
     ".*\[Ww\]atchpoint.*ival3.*Old value = 0.*New value = -1.*ival3 = count; ival4 = count;.*" \
     "watchpoint hit in reverse, fifth time"
 
+gdb_test_no_output "disable \$bpnum" "disable non-hw watchpoint"
+
 gdb_test_no_output "set can-use-hw-watchpoints 1" "enable hw watchpoints"
 
+gdb_test_no_output "enable \$bpnum" "enable hw watchpoint"
+
 ###
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-- 
2.35.1