[PATCH] gdb.base/watchpoint-unaligned.exp: Fix TCL error.

["Alexandra Hájková" <ahajkova@redhat.com>]

From: Alexandra Hajkova <ahajkova@redhat.com>

When running this test on aarch64 I've got TCL error:
ERROR:  can't read "wpoffset_to_wpnum(1)": no such element in array
ERROR:  tcl error code TCL READ VARNAME
ERROR:  tcl error info:
can't read "wpoffset_to_wpnum(1)": no such element in array ...

This patch adds checks whether the wpoffset_to_wpnum array member
exists to avoid the error.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30340
---
 .../gdb.base/watchpoint-unaligned.exp         | 38 ++++++++++---------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/gdb/testsuite/gdb.base/watchpoint-unaligned.exp b/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
index ce5a1e5bf66..d470368a6e3 100644
--- a/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
+++ b/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
@@ -121,27 +121,31 @@ foreach wpcount {4 7} {
     gdb_test_no_output -nopass "set variable offset = 1"
     set test "continue"
     set got_hit 0
-    gdb_test_multiple $test $test {
-	-re "\r\nCould not insert hardware watchpoint .*\r\n$gdb_prompt $" {
-	}
-	-re "$rwatch_exp $wpoffset_to_wpnum(1):.*alue = .*\r\n$gdb_prompt $" {
-	    set got_hit 1
-	    send_gdb "continue\n"
-	    exp_continue
-	}
-	-re " start_again .*\r\n$gdb_prompt $" {
-	}
+    if {[info exists wpoffset_to_wpnum(1)]} {
+	    gdb_test_multiple $test $test {
+		    -re "\r\nCould not insert hardware watchpoint .*\r\n$gdb_prompt $" {
+		    }
+		    -re "$rwatch_exp $wpoffset_to_wpnum(1):.*alue = .*\r\n$gdb_prompt $" {
+			    set got_hit 1
+			    send_gdb "continue\n"
+			    exp_continue
+		    }
+		    -re " start_again .*\r\n$gdb_prompt $" {
+		    }
+	    }
     }
     for {set wpoffset 1} {$wpoffset <= $wpcount} {incr wpoffset} {
-	if {$wpoffset_to_wpnum($wpoffset)} {
-	    gdb_test_no_output "delete $wpoffset_to_wpnum($wpoffset)" ""
-	}
+	    if {[info exists wpoffset_to_wpnum($wpoffset)] &&
+		    $wpoffset_to_wpnum($wpoffset)} {
+		    gdb_test_no_output "delete $wpoffset_to_wpnum($wpoffset)" ""
+	    }
     }
     set test "wpcount($wpcount)"
-    if {!$wpoffset_to_wpnum([expr $wpcount - 1])} {
-	untested $test
-	continue
-    }
+    if {[info exists wpoffset_to_wpnum([expr $wpcount - 1])] &&
+	    !$wpoffset_to_wpnum([expr $wpcount - 1])} {
+		    untested $test
+		    continue
+	    }
     if {$wpcount > 4} {
 	if {![istarget "s390*-*-*"]} {
 	    setup_kfail tdep/22389 *-*-*
-- 
2.39.2