sparcgenerator.java

用Java实现的编译器。把源代码编译成SPARC汇编程序

// $Id: SPARCGenerator.java,v 1.11 2000/10/21 23:18:09 mdeeds Exp $

package java6035.tools.ASM;

import java.io.*;

/**
 * SPARCGenerator 
 *
 * is a map on ASM that generates SPARC assembly code
 * Use this class to create an assembly listing from your
 * ASM tree.
 */
 
public final class SPARCGenerator 
{
    private PrintWriter output;

    private void checkOperand(Object o, int index, String instr)
    {
		if (o == null)
	    	throw new ASMException
			("null object supplied as operand "+index+" of "+instr);
    }

    /**
     * Opens a SPARCGenerator output to the file output given.  Call
     * gen() with your ASM structure to print it to the file.  Multiple
     * calls to gen() will be concatanated.
     *
     * @param output	Output file stream where the assembly is dumped.
     */
    public SPARCGenerator(OutputStream output)
    {
		this.output = new PrintWriter(output);
	
		this.output.print("    ! SPARC assembly: ");
		this.output.println
		    ("    ! Automatically generated by ASM.SPARCGenerator");
		this.output.println("");
    }

    /**
     * closes a SPARCGenerator output.  Use this after your final
     * call to gen().
     */
    public void done()
    {
		this.output.println("");
		this.output.close();
    }

    /**
     * Creates an assembly listing for @param asm, and prints
     * it to the output file specified in the constructor.
     * Requires that done() has not been called previously.
     * call done() exactly once after final call to gen().
     **/
   	public void gen(ASM asm)
    {
		for(int asm_iter = 0; asm_iter < asm.size(); asm_iter++)
		{
		    ASMEntry elm = asm.getEntryAt(asm_iter);

	    	if (elm instanceof SPARCInstruction) {

	        	SPARCInstruction instr = (SPARCInstruction)elm;
	        	int op = instr.getOpcode();
	    
		        SPARCOperand dest = instr.getDest();
		        SPARCOperand src1 = instr.getSrc1();
		        SPARCOperand src2 = instr.getSrc2();
                String comment = instr.getComment();
    
		        String d_rep = null, s1_rep = null, s2_rep = null;
    
		        if (dest != null)
		        {
				    d_rep = dest.toString();
	        	}	
    
	        	if (src1 != null)
		        {
				    s1_rep = src1.toString();
	        	}
	        
		        if (src2 != null)
		        {
				    s2_rep = src2.toString();
	        	}
    
		        switch(op) {

	    	        /* all the src1,src2 instructions */
	    	        case SPARCOpcode.ST:
					case SPARCOpcode.CMP:
		    	    	checkOperand(dest,0,SPARCOpcode.getStringRep(op));
		    	    	checkOperand(src1,1,SPARCOpcode.getStringRep(op));
    
						this.output.print("\t"+SPARCOpcode.getStringRep(op)+"\t"+
			                    d_rep+", "+s1_rep);
								
			        	break;
    
				    /* all the label instructions (uses dest operand) */
				    case SPARCOpcode.B:
					case SPARCOpcode.BA:
					case SPARCOpcode.BN:
					case SPARCOpcode.BNE:
					case SPARCOpcode.BE:
					case SPARCOpcode.BG:
					case SPARCOpcode.BLE:
					case SPARCOpcode.BGE:
					case SPARCOpcode.BL:
					case SPARCOpcode.BGU:
					case SPARCOpcode.BLEU:
					case SPARCOpcode.BGEU:
					case SPARCOpcode.BLU:
					case SPARCOpcode.BPOS:
					case SPARCOpcode.BNEG:
					case SPARCOpcode.BVC:
					case SPARCOpcode.BVS:
    
		        		checkOperand(dest,0,SPARCOpcode.getStringRep(op));
    
						this.output.print("\t"+SPARCOpcode.getStringRep(op)
			                    +"\t"+d_rep);
		        		break;
    
		    		
		    		/* special cases */
    		
					/*RET*/
					
					case SPARCOpcode.RET:
		        		this.output.print("\tret");						
						break;
						
					/*RESTORE*/
					case SPARCOpcode.RESTORE:
						if((src1==null)&&(src2==null)&&(dest==null))
						{
							this.output.print("\trestore");
						}
						else
						{
							checkOperand(src1,1,SPARCOpcode.getStringRep(op));
		        			checkOperand(src2,2,SPARCOpcode.getStringRep(op));
		        			checkOperand(dest,0,SPARCOpcode.getStringRep(op));
    
		        			this.output.print("\t"+SPARCOpcode.getStringRep(op)+"\t"+
			            			        s1_rep+", "+s2_rep+", "+ d_rep);
						}
						break;
					
					/* SAVE */
					case SPARCOpcode.SAVE:
						if((src1==null)&&(src2==null)&&(dest==null))
						{
							this.output.print("\tsave");
						}
						else
						{
							checkOperand(src1,1,SPARCOpcode.getStringRep(op));
		        			checkOperand(src2,2,SPARCOpcode.getStringRep(op));
		        			checkOperand(dest,0,SPARCOpcode.getStringRep(op));
    
		        			this.output.print("\t"+SPARCOpcode.getStringRep(op)+"\t"+
			            			        s1_rep+", "+s2_rep+", "+ d_rep);
						}
						break;
		
		    		/* CALL uses symbol */
	            	case SPARCOpcode.CALL:
					
		        		checkOperand(dest,0,SPARCOpcode.getStringRep(op));
		        		
						this.output.print("\tcall\t"+d_rep+",0");	
			
						break;
						
					/* LD */
					case SPARCOpcode.MOV:
					case SPARCOpcode.LD:
						checkOperand(dest,1,SPARCOpcode.getStringRep(op));
		        		checkOperand(src1,0, SPARCOpcode.getStringRep(op));
						this.output.print("\t"+SPARCOpcode.getStringRep(op)+"\t"+s1_rep+", "+d_rep);	
			
						break;
					    
		    		/* NOP */
	            	case SPARCOpcode.NOP:
		        		this.output.print("\tnop");
		        		break;
    				case SPARCOpcode.SETHI:
						this.output.print("\tsethi\t"+s1_rep+", " + d_rep);
						break;
		    		/* by default: dest,src1,src2 instructions */
		    		default:
    
		        		checkOperand(src1,1,SPARCOpcode.getStringRep(op));
		        		checkOperand(src2,2,SPARCOpcode.getStringRep(op));
		        		checkOperand(dest,0,SPARCOpcode.getStringRep(op));
    
		        		this.output.print("\t"+SPARCOpcode.getStringRep(op)+"\t"+
			            			        s1_rep+", "+s2_rep+", "+ d_rep);
		        		break;
	        	}
                
                // print the comment if there is one
                if (comment != null) {
                    this.output.println("\t\t/* " + comment + " */");
                } else {
                    this.output.println("");
                }
	    	} 
	    	else if (elm instanceof ASMLabel) {
	        	if (((ASMLabel)elm).toString().equals("main"))
	        	{
		    		this.output.println("\t.globl main");
	        	}
	        	this.output.println(((ASMLabel)elm).toString()+":");
	    	}
			
			else if (elm instanceof ASMDirective) {
				if(elm instanceof dSection)
		        	this.output.println(((ASMDirective)elm).toString());
				else
	        		this.output.println("\t"+((ASMDirective)elm).toString());
            }

            	else if (elm instanceof ASMComment) {
	        	this.output.println(((ASMComment)elm).toString());
	    	}

            	else if (elm == null) {
                // blank line
                this.output.println();
            }
        }
    }
}