LocalVariablePossibleAttributeAccess.java

package com.aptana.rdt.internal.parser.warnings;

import java.util.ArrayList;
import java.util.List;

import org.jruby.ast.ArgsNode;
import org.jruby.ast.ClassNode;
import org.jruby.ast.FCallNode;
import org.jruby.ast.LocalAsgnNode;
import org.rubypeople.rdt.core.parser.warnings.RubyLintVisitor;
import org.rubypeople.rdt.internal.core.util.ASTUtil;

import com.aptana.rdt.AptanaRDTPlugin;
import com.aptana.rdt.IProblem;

public class LocalVariablePossibleAttributeAccess extends RubyLintVisitor {

	private List<LocalAsgnNode> locals = new ArrayList<LocalAsgnNode>();

	private List<String> attributes = new ArrayList<String>();
	private boolean insideMethodSignature;

	public LocalVariablePossibleAttributeAccess(String contents) {
		super(AptanaRDTPlugin.getDefault().getOptions(), contents);
	}

	@Override
	protected String getOptionKey() {
		return AptanaRDTPlugin.COMPILER_PB_LOCAL_VARIABLE_POSSIBLE_ATTRIBUTE_ACCESS;
	}

	@Override
	public Object visitClassNode(ClassNode iVisited) {
		locals.clear();
		attributes.clear();
		return super.visitClassNode(iVisited);
	}

	@Override
	public Object visitLocalAsgnNode(LocalAsgnNode iVisited) {		
		if (!insideMethodSignature) locals.add(iVisited);
		return super.visitLocalAsgnNode(iVisited);
	}
	
	@Override
	public Object visitArgsNode(ArgsNode iVisited) {
		//  Don't add if the local being assigned inside method signature
		insideMethodSignature = true;
		return super.visitArgsNode(iVisited);
	}
	
	@Override
	public void exitArgsNode(ArgsNode iVisited) {
		super.exitArgsNode(iVisited);
		insideMethodSignature = false;
	}

	@Override
	public Object visitFCallNode(FCallNode iVisited) {
		String name = iVisited.getName();
		if (name.equals("attr_accessor") || name.equals("attr_writer")
				|| name.equals("attr")) {
			List<String> args = filterColonsFromSymbols(ASTUtil.getArgumentsFromFunctionCall(iVisited));
			if (name.equals("attr")) {
				// second arg must be "true"
				if (args.size() < 2) { 
					return super.visitFCallNode(iVisited);
				}
				if (!args.get(1).equals("true")) return super.visitFCallNode(iVisited);
				attributes.add(args.get(0));
				return super.visitFCallNode(iVisited);
			}
			attributes.addAll(args);
		}
		return super.visitFCallNode(iVisited);
	}

	private List<String> filterColonsFromSymbols(List<String> args) {
		if (args == null) return null;
		List<String> newArgs = new ArrayList<String>();
		for (String string : args) {
			if (string.startsWith(":")) {
				string = string.substring(1);
			}
			newArgs.add(string);
		}
		return newArgs;
	}

	@Override
	public void exitClassNode(ClassNode iVisited) {
		for (LocalAsgnNode local : locals) {
			if (attributes.contains(local.getName())) {
				createProblem(local.getPosition(), "Local variable assignment might be possible attribute access attempt?");
			}
		}
		super.exitClassNode(iVisited);
	}
	
	@Override
	protected int getProblemID() {
		return IProblem.LocalVariablePossibleAttributeAccess;
	}

}