2 files changed, 97 insertions, 1 deletions

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 18ef66823aa6..1fd29b2daa92 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -2019,7 +2019,7 @@ for (my $i = 0, my $repeat = 1; $i <= $opt{"NUM_TESTS"}; $i += $repeat) {
     }
 }
 
-sub set_test_option {
+sub __set_test_option {
     my ($name, $i) = @_;
 
     my $option = "$name\[$i\]";
@@ -2045,6 +2045,72 @@ sub set_test_option {
     return undef;
 }
 
+sub eval_option {
+    my ($option, $i) = @_;
+
+    # Add space to evaluate the character before $
+    $option = " $option";
+    my $retval = "";
+
+    while ($option =~ /(.*?[^\\])\$\{(.*?)\}(.*)/) {
+        my $start = $1;
+        my $var = $2;
+        my $end = $3;
+
+        # Append beginning of line
+        $retval = "$retval$start";
+
+        # If the iteration option OPT[$i] exists, then use that.
+        # otherwise see if the default OPT (without [$i]) exists.
+
+        my $o = "$var\[$i\]";
+
+        if (defined($opt{$o})) {
+            $o = $opt{$o};
+            $retval = "$retval$o";
+        } elsif (defined($opt{$var})) {
+            $o = $opt{$var};
+            $retval = "$retval$o";
+        } else {
+            $retval = "$retval\$\{$var\}";
+        }
+
+        $option = $end;
+    }
+
+    $retval = "$retval$option";
+
+    $retval =~ s/^ //;
+
+    return $retval;
+}
+
+sub set_test_option {
+    my ($name, $i) = @_;
+
+    my $option = __set_test_option($name, $i);
+    return $option if (!defined($option));
+
+    my $prev = "";
+
+    # Since an option can evaluate to another option,
+    # keep iterating until we do not evaluate any more
+    # options.
+    my $r = 0;
+    while ($prev ne $option) {
+        # Check for recursive evaluations.
+        # 100 deep should be more than enough.
+        if ($r++ > 100) {
+            die "Over 100 evaluations accurred with $name\n" .
+                "Check for recursive variables\n";
+        }
+        $prev = $option;
+        $option = eval_option($option, $i);
+    }
+
+    return $option;
+}
+
 # First we need to do is the builds
 for (my $i = 1; $i <= $opt{"NUM_TESTS"}; $i++) {
 
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index 761079edde65..48cbcc80602a 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -133,6 +133,36 @@
 # the MAKE_CMD option will be evaluated by the shell when
 # the MAKE_CMD option is passed into shell processing.
 
+#### Using options in other options ####
+#
+# Options that are defined in the config file may also be used
+# by other options. All options are evaulated at time of
+# use (except that config variables are evaluated at config
+# processing time).
+#
+# If an ktest option is used within another option, instead of
+# typing it again in that option you can simply use the option
+# just like you can config variables.
+#
+# MACHINE = mybox
+#
+# TEST = ssh root@${MACHINE} /path/to/test
+#
+# The option will be used per test case. Thus:
+#
+# TEST_TYPE = test
+# TEST = ssh root@{MACHINE}
+#
+# TEST_START
+# MACHINE = box1
+#
+# TEST_START
+# MACHINE = box2
+#
+# For both test cases, MACHINE will be evaluated at the time
+# of the test case. The first test will run ssh root@box1
+# and the second will run ssh root@box2.
+
 #### Mandatory Default Options ####
 
 # These options must be in the default section, although most