Consider the following grammar for the for statements :

for$-$stmt $-->$ for $($ var $=$exp,exp, exp$)$ do stmt

var $$ id

The informal semantic of the "for" statement is to:

Use the code generated for the three expressions between parentheses,

Initialize the loop control variable $("$var$")$ by the first expression appearing in the list,

Use the code generated for the statement

Loop by incrementing the control variable by the second expression in the list, until the control variable

value is greater than the value of the third expression in the list

a$.$ Write an attribute grammar for generating three$-$address code for the above grammar.

b$.$ Write the three$-$address code generated for the statement:

for $(i=e1,e2,e3)dos1$

Assuming that the code evaluating e$1,$ e$2,$ e$3$ are e$1.$code, e$2.$cod, and e$3.$code respectively and their values

are to be stored in $t1,t2,$ and $t3.$