Compiler theory: syntax-semantics translation

1. The syntax grammar G [E] is as follows: 

　　E→E+T | E-T | T 

　　T→T* F | T/F | F 

　　F→P^ F | P 

　　P→(E) | i 

• Construct described in claim semantically attribute grammar analysis requirements (mainly generates four yuan write portion).

 Resolution:

　　E -> E+T {E.place:=newtemp;   emit(E.place,':=',E.place'+',T.place)}

　　E -> E-T  {E.place:=newtemp;   emit(E.place,':=',E.place'-',T.place)}

　　E -> T     {E.p;ace:=newtemp;   emit(E.place,':=','uminus',T.place)}

　　T -> T*F {T.place:=newtemp;    emit(T.place,':=',T.place'*',F.place)}
　　T -> T/F {T.place:=newtemp;     emit(T.place,':=',T.place'/',F.place)}

　　T -> F    {T.place:=newtemp;     emit(T.place,';=','uminus',F.place)}

　　F -> P^F{F.place:=newtemp;     emit(F.place,':=',P.place'^',F.place)}

　　F -> P    {F.place:=newtemp;     emit(F.place,‘:=’,'uminus',P.palce)}

　　P -> (E) {P.place:=E.palce;}

　　P -> i 　{if i<>nil then　emit(P.place, ':=', i.place)　else error}

2. (OPTIONAL) third experiment: Syntax-Semantics translator

Claim:

• To achieve the above expression grammar analysis by operator priority syntax-directed translation process.
• Upon completion of the second experiment (operator priority syntax analysis) on the semantic analysis program design.
• The final output is equivalent to the test Quaternion intermediate code sequence.

Such as

Input: a + b * c, the output

(*,b,c,T1)

(+,a,T1,T2)

Input: b * (c + b) * d, the output

(*,b,c,T1)

(*,b,d,T2)

(+, T1, T2, T3)