Question

Draw or write in ASCII the symbol table the compiler would create after compiling the following SimpleC program. Then indicate for each variable, which lines (1) add the variable to the table, (2) store the variable, or (3) load the variable.

1 int x;
2 int y;
3 read x;
4 y = x + 1;
5 print y;

Answer 1

Lines 1 & 2 adds the variables x & y to the symbol table
Consider symbol table has data-type, symbol entries.

    [data-type    symbol]
       int          x
       int          y

Line 3, (read x), loads the symbol x from symbol table for reading the value and storing it into x.

Line4, (y = x + 1), loads the symbol x from symbol table, adds 1 to it and then store result into y.

Line 5, (print y), loads the symbol y from symbol table for printing the value of y.