CodeAttr.java

package com.github.miniyk2012.coding2017.coderising.jvm.attr;


import com.github.miniyk2012.coding2017.coderising.jvm.clz.ClassFile;
import com.github.miniyk2012.coding2017.coderising.jvm.cmd.ByteCodeCommand;
import com.github.miniyk2012.coding2017.coderising.jvm.cmd.CommandParser;
import com.github.miniyk2012.coding2017.coderising.jvm.constant.ConstantPool;
import com.github.miniyk2012.coding2017.coderising.jvm.loader.ByteCodeIterator;

public class CodeAttr extends AttributeInfo {
	private int maxStack ;
	private int maxLocals ;
	private int codeLen ;
	private String code;
	public String getCode() {
		return code;
	}

	private ByteCodeCommand[] cmds ;
	public ByteCodeCommand[] getCmds() {
		return cmds;
	}
	private LineNumberTable lineNumTable;
	private LocalVariableTable localVarTable;
	private StackMapTable stackMapTable;
	
	public CodeAttr(int attrNameIndex,
					int attrLen,
					int maxStack,
					int maxLocals,
					int codeLen,
					String code,
					ByteCodeCommand[] cmds) {
		super(attrNameIndex, attrLen);
		this.maxStack = maxStack;
		this.maxLocals = maxLocals;
		this.codeLen = codeLen;
		this.code = code;
		this.cmds = cmds;
	}

	public void setLineNumberTable(LineNumberTable t) {
		this.lineNumTable = t;
	}

	public void setLocalVariableTable(LocalVariableTable t) {
		this.localVarTable = t;		
	}

	public static CodeAttr parse(ClassFile clzFile, ByteCodeIterator iter){
		int attributeNameIndex = iter.nextU2toInt();
		int attributeLength = iter.nextU4toInt();
		int maxStack = iter.nextU2toInt();
		int maxLocals = iter.nextU2toInt();
		int codeLength = iter.nextU4toInt();

		String code = iter.nextUxToHexString(codeLength);
		ByteCodeCommand[] cmds = CommandParser.parse(clzFile, code);
        CodeAttr codeAttr = new CodeAttr(attributeNameIndex, attributeLength, maxStack, maxLocals, codeLength, code, cmds);

        int exceptionTableLen = iter.nextU2toInt();
        if(exceptionTableLen>0){
            String exTable = iter.nextUxToHexString(exceptionTableLen);
            System.out.println("Encountered exception table , just ignore it :" + exTable);
        }

        int attributesCount = iter.nextU2toInt();
        for (int i=0; i<attributesCount; i++) {
            int subAttrIndex = iter.nextU2toInt();
            String subAttrName = clzFile.getConstantPool().getUTF8String(subAttrIndex);
            iter.skip(-2);
            if (AttributeInfo.LINE_NUM_TABLE.equalsIgnoreCase(subAttrName)) {
                LineNumberTable lineNumberTable = LineNumberTable.parse(iter);
                codeAttr.setLineNumberTable(lineNumberTable);
            } else if (AttributeInfo.LOCAL_VAR_TABLE.equalsIgnoreCase(subAttrName)) {
                LocalVariableTable localVariableTable = LocalVariableTable.parse(iter);
                codeAttr.setLocalVariableTable(localVariableTable);
            } else if (AttributeInfo.STACK_MAP_TABLE.equalsIgnoreCase(subAttrName)) {
                StackMapTable stackMapTable = StackMapTable.parse(iter);
                codeAttr.setStackMapTable(stackMapTable);
            } else {
                throw new RuntimeException("Need code to process " + subAttrName);
            }
        }
        return codeAttr;
	}

	public String toString(ConstantPool pool){
		StringBuilder buffer = new StringBuilder();
		buffer.append("Code:").append(code).append("\n");
		for(int i=0;i<cmds.length;i++){
			buffer.append(cmds[i].toString(pool)).append("\n");
		}
		buffer.append("\n");
		buffer.append(this.lineNumTable.toString());
		buffer.append(this.localVarTable.toString(pool));
		return buffer.toString();
	}
	private void setStackMapTable(StackMapTable t) {
		this.stackMapTable = t;
	}


}