initial commit

MicroJava Compiler/src/ssw/mj/Run.java

@@ -0,0 +1,84 @@
+// MicroJava Virtual Machine
+// -------------------------
+// Syntax: java ssw.mj.Run fileName [-debug]
+// ===========================================================================
+// by Hanspeter Moessenboeck, 2002-10-28
+// edited by Albrecht Woess, 2002-10-30
+package ssw.mj;
+
+import java.io.*;
+
+public class Run {
+
+  // ----- VM internals
+  static Interpreter load(String name, boolean debug) throws IOException {
+    int codeSize;
+    byte[] sig = new byte[2];
+    DataInputStream in = new DataInputStream(new FileInputStream(name));
+    in.read(sig, 0, 2);
+    if (sig[0] != 'M' || sig[1] != 'J') {
+      in.close();
+      throw new FormatException("wrong marker");
+    }
+    codeSize = in.readInt();
+    if (codeSize <= 0) {
+      in.close();
+      throw new FormatException("codeSize <= 0");
+    }
+    int dataSize = in.readInt();
+    if (dataSize < 0) {
+      in.close();
+      throw new FormatException("dataSize < 0");
+    }
+    int startPC = in.readInt();
+    if (startPC < 0 || startPC >= codeSize) {
+      in.close();
+      throw new FormatException("startPC not in code area");
+    }
+    byte[] code = new byte[codeSize];
+    in.read(code, 0, codeSize);
+    in.close();
+
+    return new Interpreter(code, startPC, dataSize, Interpreter.ConsoleIO, debug);
+  }
+
+  public static void main(String[] args) {
+    String fileName = null;
+    boolean debug = false;
+    for (String arg : args) {
+      if (arg.equals("-debug")) {
+        debug = true;
+      } else {
+        fileName = arg;
+      }
+    }
+    if (fileName == null) {
+      System.out.println("Syntax: java ssw.mj.Run filename [-debug]");
+      return;
+    }
+    try {
+      Interpreter r = load(fileName, debug);
+
+      long startTime = System.currentTimeMillis();
+      r.run();
+
+      System.out.print("\nCompletion took " + (System.currentTimeMillis() - startTime) + " ms");
+    } catch (FileNotFoundException e) {
+      System.out.println("-- file " + fileName + " not found");
+    } catch (FormatException e) {
+      System.out.println("-- corrupted object file " + fileName + ": " + e.getMessage());
+    } catch (IOException e) {
+      System.out.println("-- error reading file " + fileName);
+    }
+  }
+}
+
+class FormatException extends IOException {
+
+  @Serial
+  private static final long serialVersionUID = 1L;
+
+  FormatException(String s) {
+    super(s);
+  }
+}