de.weltraumschaf.shackhack.ShackHackCommand.java Source code

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Here is the source code for de.weltraumschaf.shackhack.ShackHackCommand.java

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/*
 *  LICENSE
 *
 * "THE BEER-WARE LICENSE" (Revision 43):
 * "Sven Strittmatter" <weltraumschaf@googlemail.com> wrote this file.
 * As long as you retain this notice you can do whatever you want with
 * this stuff. If we meet some day, and you think this stuff is worth it,
 * you can buy me a non alcohol-free beer in return.
 *
 * Copyright (C) 2012 "Sven Strittmatter" <weltraumschaf@googlemail.com>
 */
package de.weltraumschaf.shackhack;

import com.google.common.collect.Lists;
import com.google.common.io.Files;
import de.weltraumschaf.shackhack.ShackHackException.Code;
import de.weltraumschaf.shackhack.antlr.ShackHackLexer;
import de.weltraumschaf.shackhack.antlr.ShackHackParser;
import jasmin.ClassFile;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.io.StringReader;
import java.util.List;
import org.antlr.v4.runtime.ANTLRFileStream;
import org.antlr.v4.runtime.BailErrorStrategy;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.TokenStream;

/**
 *
 * @author Sven Strittmatter <weltraumschaf@googlemail.com>
 */
class ShackHackCommand extends BaseCommand implements Runnable {

    private static final String ENCODING = "UTF-8";
    private final List<String> filesToParse = Lists.newArrayList();
    private boolean echoHelp;
    private boolean echoAssembly;
    private boolean echoDebug;

    public ShackHackCommand(final List<String> args, final PrintStream out, final InputStream in) {
        super(args, out, in);
    }

    @Override
    public void run() {
        parseArguments();

        if (echoHelp) {
            printHelp();
            return;
        }

        if (filesToParse.isEmpty()) {
            throw new ShackHackException("Give at least one source file as argument!", Code.NO_FILES_TO_PARSE);
        }

        for (final String fileName : filesToParse) {
            parseAndCompile(fileName);
        }
    }

    private void parseAndCompile(final String fileName) {
        final String className = extractClassName(fileName);
        final String asm = generateAssembly(className, fileName);

        if (echoAssembly) {
            getOut().println(asm);
        }

        compileByteCode(asm, className);
    }

    private String generateAssembly(final String className, final String fileName) {
        try {
            return new Generator().generate(className, parseSource(fileName));
        } catch (IOException ex) {
            throw new ShackHackException(String.format("Can't read file '%s'!", fileName), Code.CANT_READ_FILE); // NOPMD
        }
    }

    private void compileByteCode(final String asm, final String className) {
        try {
            final ClassFile classFile = new ClassFile();
            classFile.readJasmin(new StringReader(asm), className, false);

            if (classFile.errorCount() > 0) {
                throw new ShackHackException("Found " + classFile.errorCount() + " errors in Jasmin ASM!",
                        Code.FOUND_ERRORS_IN_ASM);
            }

            final File outFile = new File(className + ".class");
            final FileOutputStream outp = new FileOutputStream(outFile);
            classFile.write(outp);
            outp.close();
            getOut().println("Generated: " + outFile.getPath());
        } catch (IOException ex) { // NOPMD
            // No IO errors w/ string readers
        } catch (Exception ex) {
            throw new ShackHackException(ex.getMessage(), Code.EXCEPTION_DUROING_ASSEMBLY); // NOPMD
        }
    }

    private List<Instruction> parseSource(final String filename) throws IOException {
        final CharStream input = new ANTLRFileStream(filename, ENCODING);
        final ShackHackLexer lexer = new ShackHackLexer(input);
        final TokenStream tokens = new CommonTokenStream(lexer);
        final ShackHackParser parser = new ShackHackParser(tokens);

        if (echoDebug) {
            parser.setErrorHandler(new BailErrorStrategy());
        }

        final ByteCodeVisitor visitor = new ByteCodeVisitor();
        return visitor.visit(parser.program());
    }

    static String extractClassName(final String fileName) {
        return Files.getNameWithoutExtension(fileName);
    }

    private void parseArguments() {
        for (final String arg : getArgs()) {
            if (arg.charAt(0) == '-') {
                recognizeOption(arg);
            } else {
                filesToParse.add(arg);
            }
        }
    }

    private void printHelp() {
        getOut().println("Usage: hack [-h|-?|--help] [-a|--assembly] <file1> [<file2> ... <fileN>]");
        getOut().println();
        getOut().println("-h|-?|--help   Show this help.");
        getOut().println("-a|--assembly  Print assembly code to STDOUT.");
        getOut().println("-d|--debug     Print debug infos to STDOUT.");
    }

    private void recognizeOption(final String option) {
        if ("-h".equals(option) || "--help".equals(option) || "-?".equals(option)) {
            echoHelp = true;
        } else if ("-a".equals(option) || "--assembly".equals(option)) {
            echoAssembly = true;
        } else if ("-d".equals(option) || "--debug".equals(option)) {
            echoDebug = true;
        }
    }
}