Default variable values

A default assignment assigns a value only if the variable is undefined.

default <variable_name>=<value_or_expression>;

The scope of a default variable is restricted to driver-scoped with a static lifetime. A value must be assigned to a variable declared as default. The value cannot be blank. An example of declaring a default variable is:

default x = 5;

Default variables assigned in an ASL script can be overridden by the value of the variables specified during the startup of an adapter with the -D option.

Any variable assignment not defined as default can override the default value and, if one exists, the value that was assigned by using the -d option.

The following code fragment prints the number 1 if there is no integer value to assign to y.

x = 1;
default y = 1;
START
do
{       print("x=".x);
        print("y=".y);
        stop();
}
Output with the -D option:
$ sm_adapter -Dx=2 -Dy=2 default.asl
x=1
y=2
Output without the -D option:
$ sm_adapter default.asl
x=1
y=1