ktest.pl: Add -D option to override options

Add -D option that lets the user override options in the config.

For instance, if the config has: BUILD_NOCLEAN=1 which prevents mrproper
from being called before builds, and the user wants to call it once. The
user can run:

  ktest -D BUILD_NOCLEAN=0 config

And the default "BUILD_NOCLEAN" options will be disabled.

If the user wants to change the second test to do a build and not boot,
the user can run:

  ktest -D 'TEST_TYPE[2]=build' config

Where the '[#]' is for the test to assign the variable for. In the above
example, it will happen on test 2.

Cc: "John Warthog9 Hawley" <[email protected]>
Cc: Dhaval Giani <[email protected]>
Cc: Greg KH <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Steven Rostedt <[email protected]>

Author: rostedt

tools/testing/ktest/ktest.pl

@@ -21,6 +21,7 @@
 my %repeat_tests;
 my %repeats;
 my %evals;
+my @command_vars;
 
 #default opts
 my %default = (
@@ -1286,6 +1287,19 @@ sub read_config {
 
     $test_case = __read_config $config, \$test_num;
 
+    foreach my $val (@command_vars) {
+	chomp $val;
+	my %command_overrides;
+	if ($val =~ m/^\s*([A-Z_\[\]\d]+)\s*=\s*(.*?)\s*$/) {
+	    my $lvalue = $1;
+	    my $rvalue = $2;
+
+	    set_value($lvalue, $rvalue, 1, \%command_overrides, "COMMAND LINE");
+	} else {
+	    die "Invalid option definition '$val'\n";
+	}
+    }
+
     # make sure we have all mandatory configs
     get_mandatory_configs;
 
@@ -4242,8 +4256,37 @@ sub cancel_test {
     die "\nCaught Sig Int, test interrupted: $!\n"
 }
 
-$#ARGV < 1 or die "ktest.pl version: $VERSION\n   usage: ktest.pl [config-file]\n";
+sub die_usage {
+    die << "EOF"
+ktest.pl version: $VERSION
+   usage: ktest.pl [options] [config-file]
+    [options]:
+       -D value: Where value can act as an option override.
+                -D BUILD_NOCLEAN=1
+                    Sets global BUILD_NOCLEAN to 1
+                -D TEST_TYPE[2]=build
+                    Sets TEST_TYPE of test 2 to "build"
+
+EOF
+;
+}
+
+while ( $#ARGV >= 0 ) {
+    if ( $ARGV[0] eq "-D" ) {
+	shift;
+	die_usage if ($#ARGV < 1);
+	my $val = shift;
+
+	$command_vars[$#command_vars + 1] = $val;
+
+    } elsif ( $ARGV[0] eq "-h" ) {
+	die_usage;
+    } else {
+	last;
+    }
+}
 
+$#ARGV < 1 or die_usage;
 if ($#ARGV == 0) {
     $ktest_config = $ARGV[0];
     if (! -f $ktest_config) {