Aminet 30/Aminet 30 (1999)(Schatztruhe)[!][Apr 1999].iso/Aminet/dev/lang/SmallEiffel.lha/SmallEiffel/sys/runtime/SmallEiffelRuntime.java

Java Source | 1998-12-22 | 7.7 KB | 312 lines

/*
-- This file is  free  software, which  comes  along  with  SmallEiffel. This
-- software  is  distributed  in the hope that it will be useful, but WITHOUT
-- ANY  WARRANTY;  without  even  the  implied warranty of MERCHANTABILITY or
-- FITNESS  FOR A PARTICULAR PURPOSE. You can modify it as you want, provided
-- this header is kept unaltered, and a notification of the changes is added.
-- You  are  allowed  to  redistribute  it and sell it, alone or as a part of
-- another product.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - [e-mail]
--                       http://www.loria.fr/SmallEiffel
--
*/

import java.io.*;

/**
 * The SmallEiffelRuntime class implements some external "SmallEiffel"
 * features. This class must be present to execute the Java byte-code
 * generated by command `compile_to_jvm'.
 * Do not forget to add this class in your CLASSPATH system
 * environment variable.
 * You can also move this class file in an appropriate directory.
 */
public final class SmallEiffelRuntime {

    /**
     * To implement Eiffel GENERAL.se_getenv
     */
    public static String se_getenv (Object bytes) {
    String name = bytesToString(bytes);
    return System.getProperty(name);
    }

    /**
     * To implement Eiffel GENERAL.print_run_time_stack
     */
    public static void print_run_time_stack () {
    Throwable stack = new Throwable();
    System.err.println("Printing the JVM stack:");
    stack.printStackTrace();
    }

    /**
     * To implement Eiffel GENERAL.die_with_code
     */
    public static void die_with_code (int code) {
    System.exit(code);
    }

    /**
     * To implement Eiffel GENERAL.se_system
     */
    public static void se_system (Object system_command_line) {
    String scl = bytesToString(system_command_line);
    Process process;

    try {
        process = Runtime.getRuntime().exec(scl);

        process.waitFor();
        }
    catch (Exception e) {
        System.err.print("SmallEiffelRuntime: se_system(\"");
        System.err.print(scl);
        System.err.println("\") failed.");
        print_run_time_stack();
        System.err.println("Try to continue execution.");
    }
    }

    /**
     * To implement Eiffel FILE_TOOLS.se_remove
     */
    public static void se_remove (Object bytes) {
    String name = bytesToString(bytes);
    File file = new File(name);
    file.delete();
    }

    /**
     * To implement the Eiffel FILE_TOOLS.se_rename
     */
    public static void se_rename (Object old_path, Object new_path) {
    String oldPath = bytesToString(old_path);
    String newPath = bytesToString(new_path);
    File oldFile = new File(oldPath);
    File newFile = new File(newPath);

    oldFile.renameTo(newFile);
    }

    /**
     * To implement the Eiffel STD_FILE_READ.sfr_open
     */
    public static Object sfr_open (Object bytes) {
    String name = bytesToString(bytes);
    File file = new File(name);

    try {
        return new FileInputStream (file);
    } catch (FileNotFoundException e) {
        return null;
    }
    }

    /**
     * To implement the Eiffel STD_FILE_WRITE.sfw_open
     */
    public static Object sfw_open (Object bytes) {
    String name = bytesToString(bytes);
    File file = new File(name);

    try {
        return new FileOutputStream (file);
    } catch (IOException e) {
        return null;
    }
    }

    /**
     * To implement the Eiffel STRING.se_string2double
     */
    public static double se_string2double (Object number_view) {
    String number = bytesToString(number_view);

    return Double.valueOf(number).doubleValue();
    }

    /**
     * Convert <code>bytes</code> as a  <code>String </code>.
     * Assume <code>bytes</code> is a C like string (ie. with a
     * null character is the end).
     */
    public static String bytesToString (Object bytes) {
    int i = 0;
    byte b [] = ((byte[])bytes);
    while ( b[i] != 0 ) {
        i++;
    }
    return (new String(b,0,i));
    }

    public static int internal_exception_number = 3;

    public static void runtime_error(int line,
                     int column,
                     String path,
                     String type,
                     String message) {
        System.err.println("Run-time Eiffel error.");
    if (message != null) {
        System.err.println(message);
    }
    if (type != null) {
        System.err.print("Eiffel type: \"");
        System.err.print(type);
        System.err.println("\".");
    }
    if (line != 0) {
        System.err.print("Error occurs at line ");
        System.err.print(line);
        System.err.print(" column ");
        System.err.print(column);
        System.err.print(" in \"");
        System.err.print(path);
        System.err.println("\".");
    }
    print_run_time_stack();
    System.exit(1);
    }

    public static void runtime_error_bad_target(Object target,
                        int line,
                        int column,
                        String path,
                        String type,
                        String message) {

    if (target == null) {
        System.err.println("Void (null) target for a call.");
    }
    else {
        System.err.println("Bad target for a call.");
        System.err.print("Target is \"");
        System.err.print(target.toString());
        System.err.println("\"");
    }
    runtime_error(line,column,path,type,message);
    }

    public static int runtime_error_inspect(int inspect_value,
                        int line,
                        int column,
                        String path) {
    System.err.print("Bad inspect value = ");
    System.err.println(inspect_value);
    runtime_error(line,column,path,null,
              "Invalid inspect (nothing selected).");
    return inspect_value;
    }

    public static int runtime_check_loop_variant(int loop_counter,
                         int prev_variant,
                         int next_variant,
                         int line,
                         int column,
                         String path) {
    if (next_variant < 0) {
        bad_loop_variant(loop_counter,
                 prev_variant,
                 next_variant,
                 line,column,path);
        return 0;
    }
    else if (loop_counter == 0) {
        return next_variant;
    }
    else if (next_variant < prev_variant) {
        return next_variant;
    }
    else {
        bad_loop_variant(loop_counter,
                 prev_variant,
                 next_variant,
                 line,column,path);
        return 0;
    }
    }

    private static void bad_loop_variant(int loop_counter,
                    int prev_variant,
                    int next_variant,
                    int line,
                    int column,
                    String path) {
    System.err.print("Loop body counter = ");
    System.err.print(loop_counter);
    System.err.println(" (done)");
    if (loop_counter > 0) {
        System.err.print("Previous variant = ");
        System.err.println(prev_variant);
    }
    System.err.print("Current variant = ");
    System.err.print(next_variant);
    if (next_variant < 0) {
        System.err.println(" (Bad Negative value)");
    }
    else {
        System.err.println(" (must be less than previous)");
    }
    runtime_error(line,column,path,null,"Loop variant violation.");
    }

    /**
     * For -trace flag (this is a new undocumented stuff).
     */
    public static void se_trace(Object target,
                int line,
                int column,
                String path) {
    se_trace_show(line,column,path);
    }

    public static void se_trace(boolean target,
                int line,
                int column,
                String path) {
    if (target) {
        System.out.print("Current = true ");
    }
    else {
        System.out.print("Current = false ");
    }
    se_trace_show(line,column,path);
    }

    public static void se_trace(byte target,
                int line,
                int column,
                String path) {
    System.out.print("Current = ");
    System.out.print(target);
    System.out.print(" ");
    se_trace_show(line,column,path);
    }

    public static void se_trace(int target,
                int line,
                int column,
                String path) {
    System.out.print("Current = ");
    System.out.print(target);
    System.out.print(" ");
    se_trace_show(line,column,path);
    }

    public static void se_trace_show(int line,
                     int column,
                     String path) {
    System.out.print(path);
    System.out.print(" l=");
    System.out.print(line);
    System.out.print(" c=");
    System.out.print(column);
    System.out.println();
    System.out.flush();
    }

}