src/org/xwt/js/JSFunction.java

   1 // Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL]
   2 package org.xwt.js;
   3
   4 import org.xwt.util.*;
   5 import java.util.*;
   6 import java.io.*;
   7
   8 /** A JavaScript function, compiled into bytecode */
   9 public class JSFunction extends JSCallable implements ByteCodes, Tokens {
  10
  11     /** Note: code gets run in an <i>unpauseable</i> context. */
  12     public Object call(JSArray args) {
  13         JSContext cx = new JSContext(this, false);
  14         cx.invoke(args);
  15         return cx.stack.pop();
  16     }
  17
  18
  19     // Fields and Accessors ///////////////////////////////////////////////
  20
  21     int numFormalArgs = 0;         ///< the number of formal arguments
  22     String sourceName;             ///< the source code file that this block was drawn from
  23     int[] line = new int[10];      ///< the line numbers
  24     private int firstLine = -1;    ///< the first line of this script
  25     int[] op = new int[10];        ///< the instructions
  26     Object[] arg = new Object[10]; ///< the arguments to the instructions
  27     int size = 0;                  ///< the number of instruction/argument pairs
  28     JSScope parentJSScope;          ///< the default scope to use as a parent scope when executing this
  29
  30
  31     // Constructors ////////////////////////////////////////////////////////
  32
  33     public JSFunction cloneWithNewParentJSScope(JSScope s) {
  34         JSFunction ret = new JSFunction(sourceName, firstLine, s);
  35         // Reuse the same op, arg, line, and size variables for the new "instance" of the function
  36         // NOTE: Neither *this* function nor the new function should be modified after this call
  37         ret.op = this.op;
  38         ret.arg = this.arg;
  39         ret.line = this.line;
  40         ret.size = this.size;
  41         ret.numFormalArgs = this.numFormalArgs;
  42         return ret;
  43     }
  44
  45     private JSFunction(String sourceName, int firstLine, JSScope parentJSScope) {
  46         this.sourceName = sourceName;
  47         this.firstLine = firstLine;
  48         this.parentJSScope = parentJSScope;
  49     }
  50
  51     protected JSFunction(String sourceName, int firstLine, Reader sourceCode, JSScope parentJSScope) throws IOException {
  52         this(sourceName, firstLine, parentJSScope);
  53         if (sourceCode == null) return;
  54         Parser p = new Parser(sourceCode, sourceName, firstLine);
  55         while(true) {
  56             int s = size;
  57             p.parseStatement(this, null);
  58             if (s == size) break;
  59         }
  60         add(-1, LITERAL, null);
  61         add(-1, RETURN);
  62     }
  63
  64
  65
  66     // Adding and Altering Bytecodes ///////////////////////////////////////////////////
  67
  68     int get(int pos) { return op[pos]; }
  69     Object getArg(int pos) { return arg[pos]; }
  70     void set(int pos, int op_, Object arg_) { op[pos] = op_; arg[pos] = arg_; }
  71     void set(int pos, Object arg_) { arg[pos] = arg_; }
  72     int pop() { size--; arg[size] = null; return op[size]; }
  73     void paste(JSFunction other) { for(int i=0; i<other.size; i++) add(other.line[i], other.op[i], other.arg[i]); }
  74     JSFunction add(int line, int op_) { return add(line, op_, null); }
  75     JSFunction add(int line, int op_, Object arg_) {
  76         if (size == op.length - 1) {
  77             int[] line2 = new int[op.length * 2]; System.arraycopy(this.line, 0, line2, 0, op.length); this.line = line2;
  78             Object[] arg2 = new Object[op.length * 2]; System.arraycopy(arg, 0, arg2, 0, arg.length); arg = arg2;
  79             int[] op2 = new int[op.length * 2]; System.arraycopy(op, 0, op2, 0, op.length); op = op2;
  80         }
  81         this.line[size] = line;
  82         op[size] = op_;
  83         arg[size] = arg_;
  84         size++;
  85         return this;
  86     }
  87
  88
  89     // Invoking the Bytecode ///////////////////////////////////////////////////////
  90
  91     /** returns false if the thread has been paused */
  92     static Object eval(final JSContext cx) throws JS.Exn {
  93         final int initialPauseCount = cx.pausecount;
  94         OUTER: for(;; cx.pc++) {
  95         try {
  96             if (cx.f == null || cx.pc >= cx.f.size) return cx.stack.pop();
  97             int op = cx.f.op[cx.pc];
  98             Object arg = cx.f.arg[cx.pc];
  99             if(op == FINALLY_DONE) {
 100                 FinallyData fd = (FinallyData) cx.stack.pop();
 101                 if(fd == null) continue OUTER; // NOP
 102                 op = fd.op;
 103                 arg = fd.arg;
 104             }
 105             switch(op) {
 106             case LITERAL: cx.stack.push(arg); break;
 107             case OBJECT: cx.stack.push(new JSObj()); break;
 108             case ARRAY: cx.stack.push(new JSArray(JS.toNumber(arg).intValue())); break;
 109             case DECLARE: cx.scope.declare((String)(arg==null ? cx.stack.peek() : arg)); if(arg != null) cx.stack.push(arg); break;
 110             case TOPSCOPE: cx.stack.push(cx.scope); break;
 111             case JT: if (JS.toBoolean(cx.stack.pop())) cx.pc += JS.toNumber(arg).intValue() - 1; break;
 112             case JF: if (!JS.toBoolean(cx.stack.pop())) cx.pc += JS.toNumber(arg).intValue() - 1; break;
 113             case JMP: cx.pc += JS.toNumber(arg).intValue() - 1; break;
 114             case POP: cx.stack.pop(); break;
 115             case SWAP: { Object o1 = cx.stack.pop(); Object o2 = cx.stack.pop(); cx.stack.push(o1); cx.stack.push(o2); break; }
 116             case DUP: cx.stack.push(cx.stack.peek()); break;
 117             case NEWSCOPE: cx.scope = new JSScope(cx.scope); break;
 118             case OLDSCOPE: cx.scope = cx.scope.getParentJSScope(); break;
 119             case ASSERT: if (!JS.toBoolean(cx.stack.pop())) throw je("assertion failed"); break;
 120             case BITNOT: cx.stack.push(new Long(~JS.toLong(cx.stack.pop()))); break;
 121             case BANG: cx.stack.push(new Boolean(!JS.toBoolean(cx.stack.pop()))); break;
 122             case NEWFUNCTION: cx.stack.push(((JSFunction)arg).cloneWithNewParentJSScope(cx.scope)); break;
 123             case LABEL: break;
 124
 125             case TYPEOF: {
 126                 Object o = cx.stack.pop();
 127                 if (o == null) cx.stack.push(null);
 128                 else if (o instanceof JS) cx.stack.push(((JS)o).typeName());
 129                 else if (o instanceof String) cx.stack.push("string");
 130                 else if (o instanceof Number) cx.stack.push("number");
 131                 else if (o instanceof Boolean) cx.stack.push("boolean");
 132                 else cx.stack.push("unknown");
 133                 break;
 134             }
 135
 136             case PUSHKEYS: {
 137                 Object o = cx.stack.peek();
 138                 Enumeration e = ((JS)o).keys();
 139                 JSArray a = new JSArray();
 140                 while(e.hasMoreElements()) a.addElement(e.nextElement());
 141                 cx.stack.push(a);
 142                 break;
 143             }
 144
 145             case LOOP:
 146                 cx.stack.push(new LoopMarker(cx.pc, cx.pc > 0 && cx.f.op[cx.pc - 1] == LABEL ?
 147                                              (String)cx.f.arg[cx.pc - 1] : (String)null, cx.scope));
 148                 cx.stack.push(Boolean.TRUE);
 149                 break;
 150
 151             case BREAK:
 152             case CONTINUE:
 153                 while(cx.stack.size() > 0) {
 154                     Object o = cx.stack.pop();
 155                     if (o instanceof CallMarker) ee("break or continue not within a loop");
 156                     if (o instanceof TryMarker) {
 157                         if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
 158                         cx.stack.push(new FinallyData(op, arg));
 159                         cx.scope = ((TryMarker)o).scope;
 160                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 161                         continue OUTER;
 162                     }
 163                     if (o instanceof LoopMarker) {
 164                         if (arg == null || arg.equals(((LoopMarker)o).label)) {
 165                             int loopInstructionLocation = ((LoopMarker)o).location;
 166                             int endOfLoop = ((Integer)cx.f.arg[loopInstructionLocation]).intValue() + loopInstructionLocation;
 167                             cx.scope = ((LoopMarker)o).scope;
 168                             if (op == CONTINUE) { cx.stack.push(o); cx.stack.push(Boolean.FALSE); }
 169                             cx.pc = op == BREAK ? endOfLoop - 1 : loopInstructionLocation;
 170                             continue OUTER;
 171                         }
 172                     }
 173                 }
 174                 throw new Error("CONTINUE/BREAK invoked but couldn't find LoopMarker at " +
 175                                 cx.getSourceName() + ":" + cx.getLine());
 176
 177             case TRY: {
 178                 int[] jmps = (int[]) arg;
 179                 // jmps[0] is how far away the catch block is, jmps[1] is how far away the finally block is
 180                 // each can be < 0 if the specified block does not exist
 181                 cx.stack.push(new TryMarker(jmps[0] < 0 ? -1 : cx.pc + jmps[0], jmps[1] < 0 ? -1 : cx.pc + jmps[1], cx.scope));
 182                 break;
 183             }
 184
 185             case RETURN: {
 186                 Object retval = cx.stack.pop();
 187                 while(cx.stack.size() > 0) {
 188                     Object o = cx.stack.pop();
 189                     if (o instanceof TryMarker) {
 190                         if(((TryMarker)o).finallyLoc < 0) continue;
 191                         cx.stack.push(retval);
 192                         cx.stack.push(new FinallyData(RETURN));
 193                         cx.scope = ((TryMarker)o).scope;
 194                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 195                         continue OUTER;
 196                     } else if (o instanceof CallMarker) {
 197                         if (cx.scope instanceof JSTrap.JSTrapScope) {
 198                             JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)cx.scope;
 199                             if (!ts.cascadeHappened) {
 200                                 ts.cascadeHappened = true;
 201                                 JSTrap t = ts.t.next;
 202                                 while (t != null && t.f.numFormalArgs == 0) t = t.next;
 203                                 if (t == null) {
 204                                     ((JS)ts.t.trapee).put(t.name, ts.val);
 205                                     if (cx.pausecount > initialPauseCount) return null;   // we were paused
 206                                 } else {
 207                                     cx.stack.push(o);
 208                                     JSArray args = new JSArray();
 209                                     args.addElement(ts.val);
 210                                     cx.stack.push(args);
 211                                     cx.f = t.f;
 212                                     cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, ts.val);
 213                                     cx.pc = -1;
 214                                     break;
 215                                 }
 216                             }
 217                         }
 218                         cx.scope = ((CallMarker)o).scope;
 219                         cx.pc = ((CallMarker)o).pc;
 220                         cx.f = (JSFunction)((CallMarker)o).f;
 221                         cx.stack.push(retval);
 222                         continue OUTER;
 223                     }
 224                 }
 225                 throw new Error("error: RETURN invoked but couldn't find a CallMarker!");
 226             }
 227
 228             case PUT: {
 229                 Object val = cx.stack.pop();
 230                 Object key = cx.stack.pop();
 231                 Object target = cx.stack.peek();
 232                 if (target == null)
 233                     throw je("tried to put a value to the " + key + " property on the null value");
 234                 if (!(target instanceof JS))
 235                     throw je("tried to put a value to the " + key + " property on a " + target.getClass().getName());
 236                 if (key == null)
 237                     throw je("tried to assign \"" + (val==null?"(null)":val.toString()) + "\" to the null key");
 238                 JSTrap t = null;
 239                 if (target instanceof JSTrap.JSTrappable) {
 240                     t = ((JSTrap.JSTrappable)target).getTrap(val);
 241                     while (t != null && t.f.numFormalArgs == 0) t = t.next;
 242                 } else if (target instanceof JSTrap.JSTrapScope && key.equals("cascade")) {
 243                     JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)target;
 244                     t = ts.t.next;
 245                     ts.cascadeHappened = true;
 246                     while (t != null && t.f.numFormalArgs == 0) t = t.next;
 247                     if (t == null) target = ts.t.trapee;
 248                 }
 249                 if (t != null) {
 250                     cx.stack.push(new CallMarker(cx));
 251                     JSArray args = new JSArray();
 252                     args.addElement(val);
 253                     cx.stack.push(args);
 254                     cx.f = t.f;
 255                     cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, val);
 256                     cx.pc = -1;
 257                     break;
 258                 }
 259                 ((JS)target).put(key, val);
 260                 if (cx.pausecount > initialPauseCount) return null;   // we were paused
 261                 cx.stack.push(val);
 262                 break;
 263             }
 264
 265             case GET:
 266             case GET_PRESERVE: {
 267                 Object o, v;
 268                 if (op == GET) {
 269                     v = arg == null ? cx.stack.pop() : arg;
 270                     o = cx.stack.pop();
 271                 } else {
 272                     v = cx.stack.pop();
 273                     o = cx.stack.peek();
 274                     cx.stack.push(v);
 275                 }
 276                 Object ret = null;
 277                 if (o == null) throw je("tried to get property \"" + v + "\" from the null value");
 278                 if (v == null) throw je("tried to get the null key from " + o);
 279                 if (o instanceof String || o instanceof Number || o instanceof Boolean) {
 280                     ret = Internal.getFromPrimitive(o,v);
 281                     cx.stack.push(ret);
 282                     break;
 283                 } else if (o instanceof JS) {
 284                     JSTrap t = null;
 285                     if (o instanceof JSTrap.JSTrappable) {
 286                         t = ((JSTrap.JSTrappable)o).getTrap(v);
 287                         while (t != null && t.f.numFormalArgs != 0) t = t.next;
 288                     } else if (o instanceof JSTrap.JSTrapScope && v.equals("cascade")) {
 289                         t = ((JSTrap.JSTrapScope)o).t.next;
 290                         while (t != null && t.f.numFormalArgs != 0) t = t.next;
 291                         if (t == null) o = ((JSTrap.JSTrapScope)o).t.trapee;
 292                     }
 293                     if (t != null) {
 294                         cx.stack.push(new CallMarker(cx));
 295                         JSArray args = new JSArray();
 296                         cx.stack.push(args);
 297                         cx.f = t.f;
 298                         cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, null);
 299                         ((JSTrap.JSTrapScope)cx.scope).cascadeHappened = true;
 300                         cx.pc = -1;
 301                         break;
 302                     }
 303                     ret = ((JS)o).get(v);
 304                     if (cx.pausecount > initialPauseCount) return null;   // we were paused
 305                     cx.stack.push(ret);
 306                     break;
 307                 }
 308                 throw je("tried to get property " + v + " from a " + o.getClass().getName());
 309             }
 310
 311             case CALL: case CALLMETHOD: {
 312                 int numArgs = JS.toNumber(arg).intValue();
 313                 Object o = cx.stack.pop();
 314                 if(o == null) throw je("attempted to call null");
 315                 Object ret;
 316                 Object method = null;
 317                 if(op == CALLMETHOD) {
 318                     method = o;
 319                     if (method == null) throw new JS.Exn("cannot call the null method");
 320                     o = cx.stack.pop();
 321                     if(o instanceof String || o instanceof Number || o instanceof Boolean) {
 322                         JSArray arguments = new JSArray();
 323                         for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 324                         ret = Internal.callMethodOnPrimitive(o,method,arguments);
 325                         cx.stack.push(ret);
 326                         cx.pc += 2;  // skip the GET and CALL
 327                         break;
 328                     } else if (o instanceof JSCallable) {
 329                         // fall through
 330                     } else {
 331                         // put the args back on the stack and let the GET followed by CALL happen
 332                         cx.stack.push(o);
 333                         cx.stack.push(method);
 334                         break;
 335                     }
 336
 337                 } else if (o instanceof JSFunction) {
 338                     // FEATURE: use something similar to call0/call1/call2 here
 339                     JSArray arguments = new JSArray();
 340                     for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 341                     cx.stack.push(new CallMarker(cx));
 342                     cx.stack.push(arguments);
 343                     cx.f = (JSFunction)o;
 344                     cx.scope = new JSScope(cx.f.parentJSScope);
 345                     cx.pc = -1;
 346                     break;
 347                 }
 348
 349                 JSCallable c = ((JSCallable)o);
 350                 switch(numArgs) {
 351                     case 0: ret = c.call0(method); break;
 352                     case 1: ret = c.call1(method, cx.stack.pop()); break;
 353                     case 2: ret = c.call2(method, cx.stack.pop(), cx.stack.pop()); break;
 354                     default: {
 355                         JSArray arguments = new JSArray();
 356                         for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 357                         ret = c.call(method, arguments);
 358                         if (cx.pausecount > initialPauseCount) return null;   // we were paused
 359                         break;
 360                     }
 361                 }
 362                 cx.stack.push(ret);
 363                 if (method != null) cx.pc += 2;  // skip the GET and CALL if this was a GETCALL
 364
 365                 break;
 366             }
 367
 368             case THROW: {
 369                 Object o = cx.stack.pop();
 370                 if(o instanceof JS.Exn) throw (JS.Exn)o;
 371                 throw new JS.Exn(o);
 372             }
 373
 374             case ASSIGN_SUB: case ASSIGN_ADD: {
 375                 Object val = cx.stack.pop();
 376                 Object old = cx.stack.pop();
 377                 Object key = cx.stack.pop();
 378                 Object obj = cx.stack.peek();
 379                 if (val instanceof JSFunction && obj instanceof JSScope) {
 380                     JSScope parent = (JSScope)obj;
 381                     while(parent.getParentJSScope() != null) parent = parent.getParentJSScope();
 382                     if (parent instanceof JSTrap.JSTrappable) {
 383                         JSTrap.JSTrappable b = (JSTrap.JSTrappable)parent;
 384                         if (op == ASSIGN_ADD) JSTrap.addTrap(b, key, (JSFunction)val);
 385                         else JSTrap.delTrap(b, key, (JSFunction)val);
 386                         // skip over the "normal" implementation of +=/-=
 387                         cx.pc += ((Integer)arg).intValue() - 1;
 388                         break;
 389                     }
 390                 }
 391                 // use the "normal" implementation
 392                 cx.stack.push(key);
 393                 cx.stack.push(old);
 394                 cx.stack.push(val);
 395                 break;
 396             }
 397
 398             case ADD: {
 399                 int count = ((Number)arg).intValue();
 400                 if(count < 2) throw new Error("this should never happen");
 401                 if(count == 2) {
 402                     // common case
 403                     Object right = cx.stack.pop();
 404                     Object left = cx.stack.pop();
 405                     if(left instanceof String || right instanceof String)
 406                         cx.stack.push(JS.toString(left).concat(JS.toString(right)));
 407                     else cx.stack.push(new Double(JS.toDouble(left) + JS.toDouble(right)));
 408                 } else {
 409                     Object[] args = new Object[count];
 410                     while(--count >= 0) args[count] = cx.stack.pop();
 411                     if(args[0] instanceof String) {
 412                         StringBuffer sb = new StringBuffer(64);
 413                         for(int i=0;i<args.length;i++) sb.append(JS.toString(args[i]));
 414                         cx.stack.push(sb.toString());
 415                     } else {
 416                         int numStrings = 0;
 417                         for(int i=0;i<args.length;i++) if(args[i] instanceof String) numStrings++;
 418                         if(numStrings == 0) {
 419                             double d = 0.0;
 420                             for(int i=0;i<args.length;i++) d += JS.toDouble(args[i]);
 421                             cx.stack.push(new Double(d));
 422                         } else {
 423                             int i=0;
 424                             StringBuffer sb = new StringBuffer(64);
 425                             if(!(args[0] instanceof String || args[1] instanceof String)) {
 426                                 double d=0.0;
 427                                 do {
 428                                     d += JS.toDouble(args[i++]);
 429                                 } while(!(args[i] instanceof String));
 430                                 sb.append(JS.toString(new Double(d)));
 431                             }
 432                             while(i < args.length) sb.append(JS.toString(args[i++]));
 433                             cx.stack.push(sb.toString());
 434                         }
 435                     }
 436                 }
 437                 break;
 438             }
 439
 440             default: {
 441                 Object right = cx.stack.pop();
 442                 Object left = cx.stack.pop();
 443                 switch(op) {
 444
 445                 case BITOR: cx.stack.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
 446                 case BITXOR: cx.stack.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
 447                 case BITAND: cx.stack.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
 448
 449                 case SUB: cx.stack.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
 450                 case MUL: cx.stack.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
 451                 case DIV: cx.stack.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
 452                 case MOD: cx.stack.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
 453
 454                 case LSH: cx.stack.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
 455                 case RSH: cx.stack.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
 456                 case URSH: cx.stack.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
 457
 458                 case LT: case LE: case GT: case GE: {
 459                     if (left == null) left = new Integer(0);
 460                     if (right == null) right = new Integer(0);
 461                     int result = 0;
 462                     if (left instanceof String || right instanceof String) {
 463                         result = left.toString().compareTo(right.toString());
 464                     } else {
 465                         result = (int)java.lang.Math.ceil(JS.toDouble(left) - JS.toDouble(right));
 466                     }
 467                     cx.stack.push(new Boolean((op == LT && result < 0) || (op == LE && result <= 0) ||
 468                                        (op == GT && result > 0) || (op == GE && result >= 0)));
 469                     break;
 470                 }
 471
 472                 case EQ:
 473                 case NE: {
 474                     Object l = left;
 475                     Object r = right;
 476                     boolean ret;
 477                     if (l == null) { Object tmp = r; r = l; l = tmp; }
 478                     if (l == null && r == null) ret = true;
 479                     else if (r == null) ret = false; // l != null, so its false
 480                     else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
 481                     else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
 482                     else if (l instanceof String) ret = r != null && l.equals(r.toString());
 483                     else ret = l.equals(r);
 484                     cx.stack.push(new Boolean(op == EQ ? ret : !ret)); break;
 485                 }
 486
 487                 default: throw new Error("unknown opcode " + op);
 488                 } }
 489             }
 490
 491         } catch(JS.Exn e) {
 492             while(cx.stack.size() > 0) {
 493                 Object o = cx.stack.pop();
 494                 if (o instanceof CatchMarker || o instanceof TryMarker) {
 495                     boolean inCatch = o instanceof CatchMarker;
 496                     if(inCatch) {
 497                         o = cx.stack.pop();
 498                         if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
 499                     }
 500                     if(!inCatch && ((TryMarker)o).catchLoc >= 0) {
 501                         // run the catch block, this will implicitly run the finally block, if it exists
 502                         cx.stack.push(o);
 503                         cx.stack.push(catchMarker);
 504                         cx.stack.push(e.getObject());
 505                         cx.scope = ((TryMarker)o).scope;
 506                         cx.pc = ((TryMarker)o).catchLoc - 1;
 507                         continue OUTER;
 508                     } else {
 509                         cx.stack.push(e);
 510                         cx.stack.push(new FinallyData(THROW));
 511                         cx.scope = ((TryMarker)o).scope;
 512                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 513                         continue OUTER;
 514                     }
 515                 }
 516                 // no handler found within this func
 517                 if(o instanceof CallMarker) throw e;
 518             }
 519             throw e;
 520         } // end try/catch
 521         } // end for
 522     }
 523
 524
 525     // Debugging //////////////////////////////////////////////////////////////////////
 526
 527     public String toString() { return "JSFunction [" + sourceName + ":" + firstLine + "]"; }
 528     public String dump() {
 529         StringBuffer sb = new StringBuffer(1024);
 530         sb.append("\n" + sourceName + ": " + firstLine + "\n");
 531         for (int i=0; i < size; i++) {
 532             sb.append(i);
 533             sb.append(": ");
 534             if (op[i] < 0)
 535                 sb.append(bytecodeToString[-op[i]]);
 536             else
 537                 sb.append(codeToString[op[i]]);
 538             sb.append(" ");
 539             sb.append(arg[i] == null ? "(no arg)" : arg[i]);
 540             if((op[i] == JF || op[i] == JT || op[i] == JMP) && arg[i] != null && arg[i] instanceof Number) {
 541                 sb.append(" jump to ").append(i+((Number) arg[i]).intValue());
 542             } else  if(op[i] == TRY) {
 543                 int[] jmps = (int[]) arg[i];
 544                 sb.append(" catch: ").append(jmps[0] < 0 ? "No catch block" : ""+(i+jmps[0]));
 545                 sb.append(" finally: ").append(jmps[1] < 0 ? "No finally block" : ""+(i+jmps[1]));
 546             }
 547             sb.append("\n");
 548         }
 549         return sb.toString();
 550     }
 551
 552
 553     // Exception Stuff ////////////////////////////////////////////////////////////////
 554
 555     static class EvaluatorException extends RuntimeException { public EvaluatorException(String s) { super(s); } }
 556     static EvaluatorException ee(String s) {
 557         throw new EvaluatorException(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
 558     }
 559     static JS.Exn je(String s) {
 560         throw new JS.Exn(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
 561     }
 562
 563
 564     // Markers //////////////////////////////////////////////////////////////////////
 565
 566     public static class CallMarker {
 567         int pc;
 568         JSScope scope;
 569         JSFunction f;
 570         public CallMarker(JSContext cx) { pc = cx.pc + 1; scope = cx.scope; f = cx.f; }
 571     }
 572
 573     public static class CatchMarker { public CatchMarker() { } }
 574     private static CatchMarker catchMarker = new CatchMarker();
 575
 576     public static class LoopMarker {
 577         public int location;
 578         public String label;
 579         public JSScope scope;
 580         public LoopMarker(int location, String label, JSScope scope) {
 581             this.location = location;
 582             this.label = label;
 583             this.scope = scope;
 584         }
 585     }
 586     public static class TryMarker {
 587         public int catchLoc;
 588         public int finallyLoc;
 589         public JSScope scope;
 590         public TryMarker(int catchLoc, int finallyLoc, JSScope scope) {
 591             this.catchLoc = catchLoc;
 592             this.finallyLoc = finallyLoc;
 593             this.scope = scope;
 594         }
 595     }
 596     public static class FinallyData {
 597         public int op;
 598         public Object arg;
 599         public FinallyData(int op, Object arg) { this.op = op; this.arg = arg; }
 600         public FinallyData(int op) { this(op,null); }
 601     }
 602 }
 603