* lib/gdb.exp (banned_variables_traced): New global variable.

	(gdb_init, gdb_finish): Use new variable to avoid multiple tracing.
	(gdb_init): Use `trace add variable' instead of obsolete
	`trace variable'.

1 files changed, 23 insertions, 6 deletions

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 833fbf2..c2014dd 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -2520,6 +2520,15 @@ if ![info exists gdb_test_timeout] {
 # an error when that happens.
 set banned_variables { bug_id prms_id }
 
+# gdb_init is called by runtest at start, but also by several
+# tests directly; gdb_finish is only called from within runtest after
+# each test source execution.
+# Placing several traces by repetitive calls to gdb_init leads
+# to problems, as only one trace is removed in gdb_finish.
+# To overcome this possible problem, we add a variable that records
+# if the banned variables are traced.
+set banned_variables_traced 0
+
 proc gdb_init { args } {
     # Reset the timeout value to the default.  This way, any testcase
     # that changes the timeout value without resetting it cannot affect
@@ -2530,9 +2539,13 @@ proc gdb_init { args } {
 
     # Block writes to all banned variables...
     global banned_variables
-    foreach banned_var $banned_variables {
-        global "$banned_var"
-        trace variable "$banned_var" w error
+    global banned_variables_traced
+    if (!$banned_variables_traced) {
+    	foreach banned_var $banned_variables {
+            global "$banned_var"
+            trace add variable "$banned_var" write error
+	}
+	set banned_variables_traced 1
     }
 
     return [eval default_gdb_init $args];
@@ -2552,9 +2565,13 @@ proc gdb_finish { } {
     # Unblock write access to the banned variables.  Dejagnu typically
     # resets some of them between testcases.
     global banned_variables
-    foreach banned_var $banned_variables {
-        global "$banned_var"
-        trace remove variable "$banned_var" write error
+    global banned_variables_traced
+    if ($banned_variables_traced) {
+    	foreach banned_var $banned_variables {
+            global "$banned_var"
+            trace remove variable "$banned_var" write error
+	}
+	set banned_variables_traced 0
     }
 }