Java Compiler Creation Help..Please
- by Brian
I need some help with my code here...What we are trying to do is make a compiler that will read a file containing Machine Code and converting it to 100 lines of 4 bits example: this code is the machine code being converting to opcode and operands. I need some help please.. thanks
799
798
198
499
1008
1108
899
909
898
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Everything compiles but when I go and run my Test.java I get the following OutPut:
Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Scanner.java:1516)
at Compiler.FirstPass(Compiler.java:22)
at Compiler.compile(Compiler.java:11)
at Test.main(Test.java:5)
Here is my class Compiler:
import java.io.*;
import java.io.DataOutputStream;
import java.util.NoSuchElementException;
import java.util.Scanner;
class Compiler{
private int lc = 0;
private int dc = 99;
public void compile(String filename)
{
SymbolList symbolTable = FirstPass(filename);
SecondPass(symbolTable, filename);
}
public SymbolList FirstPass(String filename)
{
File file = new File(filename);
SymbolList temp = new SymbolList();
int dc = 99;
int lc = 0;
try{
Scanner scan = new Scanner(file);
String line = scan.nextLine();
String[] linearray = line.split(" ");
while(line!=null){
if(!linearray[0].equals("REM")){
if(!this.isInstruction(linearray[0])){
linearray[0]=removeColon(linearray[0]);
if(this.isInstruction(linearray[1])){
temp.add(new Symbol(linearray[0], lc, null));
lc++;
} else {
temp.add(new Symbol(linearray[0], dc, Integer.valueOf((linearr\
ay[2]))));
dc--;
}
} else {
if(!linearray[0].equals("REM"))
lc++;
}
}
try{
line = scan.nextLine();
} catch(NoSuchElementException e){
line=null;
break;
}
linearray = line.split(" ");
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return temp;
}
public String makeFilename(String filename)
{
return filename + ".ex";
}
public String removeColon(String str)
{
if(str.charAt(str.length()-1) == ':'){
return str.substring(0, str.length()-1);
} else {
return str;
}
}
public void SecondPass(SymbolList symbolTable, String filename){
try {
int dc = 99;
//Open file for reading
File file = new File(filename);
Scanner scan = new Scanner(file);
//Make filename of new executable file
String newfile = makeFilename(filename);
//Open Output Stream for writing new file.
FileOutputStream os = new FileOutputStream(filename);
DataOutputStream dos = new DataOutputStream(os);
//Read First line. Split line by Spaces into linearray.
String line = scan.nextLine();
String[] linearray = line.split(" ");
while(scan.hasNextLine()){
if(!linearray[0].equals("REM")){
int inst=0, opcode, loc;
if(isInstruction(linearray[0])){
opcode = getOpcode(linearray[0]);
loc = symbolTable.searchName(linearray[1]).getMemloc();
inst = (opcode*100)+loc;
} else if(!isInstruction(linearray[0])){
if(isInstruction(linearray[1])){
opcode = getOpcode(linearray[1]);
if(linearray[1].equals("STOP"))
inst=0000;
else {
loc = symbolTable.searchName(linearray[2]).getMemloc();
inst = (opcode*100)+loc;
}
}
if(linearray[1].equals("DC"))
dc--;
}
System.out.println(inst);
dos.writeInt(inst);
linearray = line.split(" ");
}
if(scan.hasNextLine())
{
line = scan.nextLine();
}
}
scan.close();
for(int i = lc; i <= dc; i++)
{
dos.writeInt(0);
}
for(int i = dc+1; i<100; i++){
dos.writeInt(symbolTable.searchLocation(i).getValue());
if(i!=99)
dos.writeInt(0);
}
dos.close();
os.close();
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public int getOpcode(String inst){
int toreturn = -1;
if(isInstruction(inst)){
if(inst.equals("STOP"))
toreturn=0;
if(inst.equals("LD"))
toreturn=1;
if(inst.equals("STO"))
toreturn=2;
if(inst.equals("ADD"))
toreturn=3;
if(inst.equals("SUB"))
toreturn=4;
if(inst.equals("MPY"))
toreturn=5;
if(inst.equals("DIV"))
toreturn=6;
if(inst.equals("IN"))
toreturn=7;
if(inst.equals("OUT"))
toreturn=8;
if(inst.equals("B"))
toreturn=9;
if(inst.equals("BGTR"))
toreturn=10;
if(inst.equals("BZ"))
toreturn=11;
return toreturn;
} else {
return -1;
}
}
public boolean isInstruction(String totest){
boolean toreturn = false;
String[] labels = {"IN", "LD", "SUB", "BGTR", "BZ", "OUT", "B", "STO", "STOP", "AD\
D", "MTY", "DIV"};
for(int i = 0; i < 12; i++){
if(totest.equals(labels[i]))
toreturn = true;
}
return toreturn;
}
}
And here is my class Computer:
import java.io.*;
import java.util.NoSuchElementException;
import java.util.Scanner;
class Computer{
private Cpu cpu;
private Input in;
private OutPut out;
private Memory mem;
public Computer() throws IOException
{
Memory mem = new Memory(100);
Input in = new Input();
OutPut out = new OutPut();
Cpu cpu = new Cpu();
System.out.println(in.getInt());
}
public void run() throws IOException
{
cpu.reset();
cpu.setMDR(mem.read(cpu.getMAR()));
cpu.fetch2();
while (!cpu.stop())
{
cpu.decode();
if (cpu.OutFlag())
OutPut.display(mem.read(cpu.getMAR()));
if (cpu.InFlag())
mem.write(cpu.getMDR(),in.getInt());
if (cpu.StoreFlag())
{
mem.write(cpu.getMAR(),in.getInt());
cpu.getMDR();
}
else
{
cpu.setMDR(mem.read(cpu.getMAR()));
cpu.execute();
cpu.fetch();
cpu.setMDR(mem.read(cpu.getMAR()));
cpu.fetch2();
}
}
}
public void load()
{
mem.loadMemory();
}
}
Here is my Memory class:
import java.io.*;
import java.util.NoSuchElementException;
import java.util.Scanner;
class Memory{
private MemEl[] memArray;
private int size;
private int[] mem;
public Memory(int s)
{size = s;
memArray = new MemEl[s];
for(int i = 0; i < s; i++)
memArray[i] = new MemEl();
}
public void write (int loc,int val)
{if (loc >=0 && loc < size)
memArray[loc].write(val);
else
System.out.println("Index Not in Domain");
}
public int read (int loc)
{return memArray[loc].read();
}
public void dump()
{
for(int i = 0; i < size; i++)
if(i%1 == 0)
System.out.println(memArray[i].read());
else
System.out.print(memArray[i].read());
}
public void writeTo(int location, int value)
{
mem[location] = value;
}
public int readFrom(int location)
{
return mem[location];
}
public int size()
{
return mem.length;
}
public void loadMemory() {
this.write(0, 799);
this.write(1, 798);
this.write(2, 198);
this.write(3, 499);
this.write(4, 1008);
this.write(5, 1108);
this.write(6, 899);
this.write(7, 909);
this.write(8, 898);
this.write(9, 0000);
}
public void loadFromFile(String filename){
try {
FileReader fr = new FileReader(filename);
BufferedReader br = new BufferedReader(fr);
String read=null;
int towrite=0;
int l=0;
do{
try{
read=br.readLine();
towrite = Integer.parseInt(read);
}catch(Exception e){
}
this.write(l, towrite);
l++;
}while(l<100);
}catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Here is my Test class:
public class Test{
public static void main(String[] args) throws java.io.IOException {
Compiler compiler = new Compiler();
compiler.compile("program.txt");
}
}
