2 files changed, 121 insertions, 0 deletions

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 65003a196305..18ef66823aa6 100755
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -114,6 +114,7 @@ my $successes = 0;
 
 my %entered_configs;
 my %config_help;
+my %variable;
 
 $config_help{"MACHINE"} = << "EOF"
  The machine hostname that you will test.
@@ -262,6 +263,39 @@ sub get_ktest_configs {
     }
 }
 
+sub process_variables {
+    my ($value) = @_;
+    my $retval = "";
+
+    # We want to check for '\', and it is just easier
+    # to check the previous characet of '$' and not need
+    # to worry if '$' is the first character. By adding
+    # a space to $value, we can just check [^\\]\$ and
+    # it will still work.
+    $value = " $value";
+
+    while ($value =~ /(.*?[^\\])\$\{(.*?)\}(.*)/) {
+        my $begin = $1;
+        my $var = $2;
+        my $end = $3;
+        # append beginning of value to retval
+        $retval = "$retval$begin";
+        if (defined($variable{$var})) {
+            $retval = "$retval$variable{$var}";
+        } else {
+            # put back the origin piece.
+            $retval = "$retval\$\{$var\}";
+        }
+        $value = $end;
+    }
+    $retval = "$retval$value";
+
+    # remove the space added in the beginning
+    $retval =~ s/ //;
+
+    return "$retval"
+}
+
 sub set_value {
     my ($lvalue, $rvalue) = @_;
 
@@ -271,10 +305,22 @@ sub set_value {
     if ($rvalue =~ /^\s*$/) {
         delete $opt{$lvalue};
     } else {
+        $rvalue = process_variables($rvalue);
         $opt{$lvalue} = $rvalue;
     }
 }
 
+sub set_variable {
+    my ($lvalue, $rvalue) = @_;
+
+    if ($rvalue =~ /^\s*$/) {
+        delete $variable{$lvalue};
+    } else {
+        $rvalue = process_variables($rvalue);
+        $variable{$lvalue} = $rvalue;
+    }
+}
+
 sub read_config {
     my ($config) = @_;
 
@@ -387,6 +433,22 @@ sub read_config {
                     $repeats{$val} = $repeat;
                 }
             }
+        } elsif (/^\s*([A-Z_\[\]\d]+)\s*:=\s*(.*?)\s*$/) {
+            next if ($skip);
+
+            my $lvalue = $1;
+            my $rvalue = $2;
+
+            # process config variables.
+            # Config variables are only active while reading the
+            # config and can be defined anywhere. They also ignore
+            # TEST_START and DEFAULTS, but are skipped if they are in
+            # on of these sections that have SKIP defined.
+            # The save variable can be
+            # defined multiple times and the new one simply overrides
+            # the prevous one.
+            set_variable($lvalue, $rvalue);
+
         } else {
             die "$name: $.: Garbage found in config\n$_";
         }
diff --git a/tools/testing/ktest/sample.conf b/tools/testing/ktest/sample.conf
index 87bf92a2eb99..761079edde65 100644
--- a/tools/testing/ktest/sample.conf
+++ b/tools/testing/ktest/sample.conf
@@ -73,6 +73,65 @@
 # ktest will fail to execute, and no tests will run.
 #
 
+#### Config variables ####
+#
+# This config file can also contain "config variables".
+# These are assigned with ":=" instead of the ktest option
+# assigment "=".
+#
+# The difference between ktest options and config variables
+# is that config variables can be used multiple times,
+# where each instance will override the previous instance.
+# And that they only live at time of processing this config.
+#
+# The advantage to config variables are that they can be used
+# by any option or any other config variables to define thing
+# that you may use over and over again in the options.
+#
+# For example:
+#
+# USER      := root
+# TARGET    := mybox
+# TEST_CASE := ssh ${USER}@${TARGET} /path/to/my/test
+#
+# TEST_START
+# MIN_CONFIG = config1
+# TEST = ${TEST_CASE}
+#
+# TEST_START
+# MIN_CONFIG = config2
+# TEST = ${TEST_CASE}
+#
+# TEST_CASE := ssh ${USER}@${TARGET} /path/to/my/test2
+#
+# TEST_START
+# MIN_CONFIG = config1
+# TEST = ${TEST_CASE}
+#
+# TEST_START
+# MIN_CONFIG = config2
+# TEST = ${TEST_CASE}
+#
+# TEST_DIR := /home/me/test
+#
+# BUILD_DIR = ${TEST_DIR}/linux.git
+# OUTPUT_DIR = ${TEST_DIR}/test
+#
+# Note, the config variables are evaluated immediately, thus
+# updating TARGET after TEST_CASE has been assigned does nothing
+# to TEST_CASE.
+#
+# As shown in the example, to evaluate a config variable, you
+# use the ${X} convention. Simple $X will not work.
+#
+# If the config variable does not exist, the ${X} will not
+# be evaluated. Thus:
+#
+# MAKE_CMD = PATH=/mypath:${PATH} make
+#
+# If PATH is not a config variable, then the ${PATH} in
+# the MAKE_CMD option will be evaluated by the shell when
+# the MAKE_CMD option is passed into shell processing.
 
 #### Mandatory Default Options ####