Merge branch 'patrick' into simulator

src/assembler/Assembler.java

@@ -1,5 +1,155 @@
 package assembler;
 
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+
 public class Assembler {
+	//{"LW","SW","ADDI","BEQ","JMP"}
+	private static ArrayList<String> instructionWithImmediate =new ArrayList<String>();
+	private int lineNumber;
+	public Assembler(){
+		lineNumber =0;
+		instructionWithImmediate.add("LW");
+		instructionWithImmediate.add("SW");
+		instructionWithImmediate.add("ADDI");
+		instructionWithImmediate.add("BEQ");
+		instructionWithImmediate.add("JMP");	
+	}
+	public ArrayList<Short> parse(String fileName)throws IOException, AssemblyException{
+
+			BufferedReader reader = new BufferedReader(new FileReader(fileName));
+			ArrayList<Short> parsedInstructions = new ArrayList<Short>();
+			String instruction ="";
+
+				while((instruction = reader.readLine())!=null){
+					lineNumber++;
+					int j;
+					for(j =0;j<instruction.length();j++){
+						//getting to the first space to see where to split from 
+						if(instruction.charAt(j)==' '){
+							break;
+						}
+					}
+					short instructionParsed = 0;
+					String operation = instruction.substring(0, j).toUpperCase().trim();//splitting the operation from the arguments
+
+					instructionParsed |= getCode(operation);
+
+					String arguments = instruction.substring(j);//extracting the arguments 
+
+					String [] argumentsSplited = arguments.split(",");//splitting the arguments 
+
+					for(int i =0; i<argumentsSplited.length;i++){
+
+						String argument = argumentsSplited[i].toUpperCase().trim();
+
+						if(!(instructionWithImmediate.contains(operation)&& i==argumentsSplited.length-1)){
+							instructionParsed <<=3;
+							instructionParsed |= getCode(argument);
+						}else{
+							if(operation.equals("JMP")){
+								if(Integer.parseInt(argument)<512 && Integer.parseInt(argument)>-513){
+									instructionParsed <<=10;
+									instructionParsed |= (Short.parseShort(argument)&0x03ff);//to make all but the least significant 10 bits zeroes	
+								}else{
+									throw new AssemblyException("The Immediate of the JMP instruction must be between 511 and -512 at line number :"+lineNumber);
+								}
+
+							}else{
+								if(Integer.parseInt(argument)<63 && Integer.parseInt(argument)>-64){
+									instructionParsed <<=7;
+									instructionParsed |= (Byte.parseByte(argument)&0x7f);//to make all but the least significant 7 bits zeroes
+
+
+								}else{
+									throw new AssemblyException("The Immediate of the BEQ,LW,SW,and ADDI instruction must be between 63 and -64 at line number :"+lineNumber);
 
+								}
+														}
+
+						}
+					}
+					switch(operation){
+					case "JALR":instructionParsed<<=7;break;
+					case "RET":instructionParsed<<=10;break;
+					case "NAND":
+					case "SUB":
+					case "ADD":
+					case "MUL":instructionParsed<<=4;
+								instructionParsed |= getFunctionCode(operation);
+								break;
+
+					}
+					parsedInstructions.add(instructionParsed);
+				}
+				reader.close();
+				//TODO: write the assembly in a seperate file
+				return  parsedInstructions;
+
+	}
+
+	private short getFunctionCode(String operation) {
+		switch(operation){
+
+		case "NAND":return 0b0010;
+		case "SUB":return 0b0001;
+		case "ADD":return 0b0000;
+		case "MUL":return 0b0011;
+
+		}
+		return -1;
+
+	}
+	//This method is for getting the code that corresponds to the operation or the registers 
+	private short getCode(String nameInText) throws AssemblyException {
+		switch(nameInText){
+
+		case "R0":
+		case "LW":return 0b000;
+		case "R1":
+		case "SW":return 0b001;
+		case "R2":
+		case "BEQ" :return 0b010;
+		case "R3":
+		case "ADDI": return 0b011;
+		case "R4":
+		case "JMP":return 0b100;
+		case "R5":
+		case "JALR":return 0b101;
+		case "R6":
+		case "RET":return 0b110;
+		case "R7":
+		case "NAND":
+		case "SUB":
+		case "ADD":
+		case "MUL":return 0b111;
+		default: throw new AssemblyException("There is no such instruction or register at line number : "+lineNumber);
+		}
+
+	}
+	public static void main(String[] args) {
+		Assembler assembler = new Assembler();
+		try {
+			ArrayList<Short> result = assembler.parse("test.asm");
+			for(int i = 0;i<result.size();i++){
+				Short line = result.get(i);
+				System.out.println(line);
+				String binary =Integer.toBinaryString(line);
+				if(binary.length()>16){
+					binary =binary.substring(binary.length()-16);
+				}else{
+					while(binary.length()<16){
+						binary="0"+binary;
+					}
+				}
+				System.out.println(binary);
+			}
+		} catch (IOException | AssemblyException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+	}
 }

src/assembler/AssemblyException.java

@@ -0,0 +1,14 @@
+package assembler;
+
+public class AssemblyException extends Exception {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = -3781245802480302572L;
+	public AssemblyException(String msg){
+		super(msg);
+	}
+
+
+}