FrontendMain.java

package de.fuberlin.projecta;

import de.fuberlin.commons.lexer.IToken;
import de.fuberlin.commons.parser.ISyntaxTree;
import de.fuberlin.projecta.analysis.DebuggingHelper;
import de.fuberlin.projecta.analysis.SemanticAnalyzer;
import de.fuberlin.projecta.analysis.SemanticException;
import de.fuberlin.projecta.analysis.ast.AbstractSyntaxTree;
import de.fuberlin.projecta.lexer.io.FileCharStream;
import de.fuberlin.projecta.lexer.io.ICharStream;
import de.fuberlin.projecta.parser.Parser;
import de.fuberlin.projecta.utils.StringUtils;

/**
 * Runnable class for executing the complete frontend
 * 
 * Prints out LLVM-Code only
 */
public class FrontendMain {

	static String genCode(ICharStream stream, boolean verbose) {
		Parser parser = ParserMain.parse(stream, verbose);
		if (parser == null) {
			System.err.println("Parsing failed.");
			return null;
		}

		ISyntaxTree tree = parser.getParseTree();
		SemanticAnalyzer analyzer = new SemanticAnalyzer(tree);
		try {
			analyzer.analyze();
		} catch (SemanticException e) {
			System.out.println("\nError: Failed to parse.");
			System.out.println(e.getMessage());

			// try to find where it happened
			AbstractSyntaxTree node = e.getNode();
			if (verbose) {
				System.out.println("Node that threw the exception: " + e.getNode());
			}

			IToken token = DebuggingHelper.extractPosition(node);
			if (token != null)
				System.out.println("Error near: '" + token.getText() + "' near line: " + token.getLineNumber() + ", column: " + token.getOffset());

			if (verbose) {
				if (analyzer.getAST() != null) {
					analyzer.getAST().printTree();
				}
				throw e;
			}
			return null;
		}

		if (verbose) {
			analyzer.getAST().printTree();
		}

		return analyzer.getAST().genCode();
	}

	private static void run(ICharStream stream) {
		final String code = genCode(stream, true);
		System.out.println("Generated code:");
		System.out.flush();
		System.out.println(code);
	}

	public static void main(String[] args) {
		if (args.length == 0) {
			System.out.println("Reading from stdin. Exit with new line and Ctrl+D.");
			ICharStream stream = StringUtils.readFromStdin();
			run(stream);
		} else if (args.length == 1) {
			final String path = args[0];
			FileCharStream stream = StringUtils.readFromFile(path);
			run(stream);
		} else {
			System.out.println("Wrong number of parameters.");
		}
	}

}