Two SAS system options are very helpful in debugging macro programs. They are
mprint and mlogic.
Let’s take a look at an example. In the macro program below, a data set with
a given name and a given number of observations is generated.
%macro test(num, data);
data &data;
do i = 1 to #
x = ranuni(-1);
output;
end;
run;
proc means data = &data;
var x;
run;
%mend;
How do we know what is happening when we run this macro program? Let’s turn
on the option of mprint and mlogic and run the program.
options mprint mlogic; %test(10, test);
In the log window, we will see the following.
1246 options mprint mlogic; 1247 %test(10, test); MLOGIC(TEST): Beginning execution. MLOGIC(TEST): Parameter NUM has value 10 MLOGIC(TEST): Parameter DATA has value test MPRINT(TEST): data test; MPRINT(TEST): do i = 1 to 10; MPRINT(TEST): x = ranuni(-1); MPRINT(TEST): output; MPRINT(TEST): end; MPRINT(TEST): run; MPRINT(TEST): proc means data = test; MPRINT(TEST): var x; MPRINT(TEST): run; MLOGIC(TEST): Ending execution.
As shown above, option mlogic tells us the parameter values and option
mprint translates the macro language to regular SAS language.