LFTCompiler

Progetto per il Corso di Linguaggi Formali e Traduttori

• Doc del Progetto
• Regole Semantiche

Translator

SDT

• <prog> ::== prog.lnext=newLabel() statlist.lnext=prog.lnext <statlist> emitLabel(prog.lnext) EOF
• <statlist> ::== stat.lnext=newLabel() <stat> emitLabel(stat.lnext) statlistp.lnext=statlist.lnext <statlistp>
• <statlistp> ::== ; stat.lnext=newLabel() <stat> emitLabel(lnext_stat) <statlistp> ::== \(\epsilon\) goto statlistp.lnext
• <stat> ::== = ID stat.id_addr=st.lookupAddress(ID.lexeme) if(stat.id_addr==-1) { stat.id_addr=count; st.insert(ID.lexeme,count++) } <expr> istore stat.id_addr || goto lnext ::== print ( <exprlist> ) for(n=exprlist.n; n>0; n--) { invokestatic 1 } ::== read ( ID ) stat.id_addr = &ID.lexeme if(stat.id_addr==-1) { stat.id_addr=count; st.insert(ID.lexeme,count++) } invokestatic 0 || istore stat.id_addr || goto lnext ::== cond whenlist.else=newLabel() || whenlist.exit=newLabel() <whenlist> emitLabel(whenlist.else) else stat1.lnext=whenlist.exit <stat1> emitLabel(whenlist.exit) goto stat.lnext ::== while ( bexpr.true=newLabel() || bexpr.false=stat.lnext emitLabel(bexpr.true) <bexpr> ) stat1.lnext=stat.lnext <stat1> ::== { || statlist.lnext=stat.lnext || <statlist> }
• <whenlist> ::== whenitem.false = newLabel() <whenitem> goto whenitem.false emitLabel(whenitem.false) ~whenlistp.exit = whenlist.exit <whenlistp> goto whenlist.else
• <whenlistp> ::== whenitem.false = newLabel() <whenitem> goto whenlistp_exit emitLabel(whenitem.false) <whenlistp> ::== \(\epsilon\)
• <whenitem> ::== when ( bexpr.true=newLabel() bexpr.false=whenitem.false <bexpr> ) do emitLabel(bexpr.true) stat.lnext=newLabel() <stat> emitLabel(stat.lnext)
• <bexpr> ::== RELOP <expr> <expr> if_icmpRELOP bexpr.false ::== true goto bexpr.true ::== false goto bexpr.false ::== ! <bexpr1> goto bexpr1.false ::== && ( bexpr1.true=newLabel() || bexpr1.false=bexpr.false <bexpr1> goto bexpr1.true emitLabel(bexpr1.true) bexpr2.true=bexpr.true || bexpr2.false=bexpr.false <bexpr2> ) ::== || ( bexpr1.false=newLabel() || bexpr1.true=bexpr.true <bexpr1> goto bexpr.true emitLabel(bexpr1.false) bexpr2.true=bexpr.true || bexpr2.false=bexpr.false <bexpr2> )
• <exprlist> ::== <expr> <exprlistp> exprlist.n=1+exprlistp.n
• <exprlistp> ::== <expr> <exprlistp1> exprlistp.n=1+exprlistp1.n ::== \(\epsilon\) exprlistp.n=0
• <expr> ::== + ( <exprlist> ) for(n=exprlist.n-1; n>0; n--) { iadd } ::== - <expr> <expr> isub ::== * ( <exprlist> ) for(n=exprlist.n-1; n>0; n--) { imul } ::== / <expr> <expr> idiv ::== ID expr.addr=st.lookupAddress(ID.lexeme) iload expr.addr ::== NUM ldc NUM.value