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: {
 116                 int depth = (1 + (arg == null ? 1 : toInt(arg)));
 117                 Object save = cx.stack.elementAt(cx.stack.size() - 1);
 118                 for(int i=cx.stack.size() - 1; i > cx.stack.size() - depth; i--)
 119                     cx.stack.setElementAt(cx.stack.elementAt(i-1), i);
 120                 cx.stack.setElementAt(save, cx.stack.size() - depth);
 121                 break; }
 122             case DUP: cx.stack.push(cx.stack.peek()); break;
 123             case NEWSCOPE: cx.scope = new JSScope(cx.scope); break;
 124             case OLDSCOPE: cx.scope = cx.scope.getParentJSScope(); break;
 125             case ASSERT: if (!JS.toBoolean(cx.stack.pop())) throw je("assertion failed"); break;
 126             case BITNOT: cx.stack.push(new Long(~JS.toLong(cx.stack.pop()))); break;
 127             case BANG: cx.stack.push(new Boolean(!JS.toBoolean(cx.stack.pop()))); break;
 128             case NEWFUNCTION: cx.stack.push(((JSFunction)arg).cloneWithNewParentJSScope(cx.scope)); break;
 129             case LABEL: break;
 130
 131             case TYPEOF: {
 132                 Object o = cx.stack.pop();
 133                 if (o == null) cx.stack.push(null);
 134                 else if (o instanceof JS) cx.stack.push(((JS)o).typeName());
 135                 else if (o instanceof String) cx.stack.push("string");
 136                 else if (o instanceof Number) cx.stack.push("number");
 137                 else if (o instanceof Boolean) cx.stack.push("boolean");
 138                 else cx.stack.push("unknown");
 139                 break;
 140             }
 141
 142             case PUSHKEYS: {
 143                 Object o = cx.stack.peek();
 144                 Enumeration e = ((JS)o).keys();
 145                 JSArray a = new JSArray();
 146                 while(e.hasMoreElements()) a.addElement(e.nextElement());
 147                 cx.stack.push(a);
 148                 break;
 149             }
 150
 151             case LOOP:
 152                 cx.stack.push(new LoopMarker(cx.pc, cx.pc > 0 && cx.f.op[cx.pc - 1] == LABEL ?
 153                                              (String)cx.f.arg[cx.pc - 1] : (String)null, cx.scope));
 154                 cx.stack.push(Boolean.TRUE);
 155                 break;
 156
 157             case BREAK:
 158             case CONTINUE:
 159                 while(cx.stack.size() > 0) {
 160                     Object o = cx.stack.pop();
 161                     if (o instanceof CallMarker) ee("break or continue not within a loop");
 162                     if (o instanceof TryMarker) {
 163                         if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
 164                         cx.stack.push(new FinallyData(op, arg));
 165                         cx.scope = ((TryMarker)o).scope;
 166                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 167                         continue OUTER;
 168                     }
 169                     if (o instanceof LoopMarker) {
 170                         if (arg == null || arg.equals(((LoopMarker)o).label)) {
 171                             int loopInstructionLocation = ((LoopMarker)o).location;
 172                             int endOfLoop = ((Integer)cx.f.arg[loopInstructionLocation]).intValue() + loopInstructionLocation;
 173                             cx.scope = ((LoopMarker)o).scope;
 174                             if (op == CONTINUE) { cx.stack.push(o); cx.stack.push(Boolean.FALSE); }
 175                             cx.pc = op == BREAK ? endOfLoop - 1 : loopInstructionLocation;
 176                             continue OUTER;
 177                         }
 178                     }
 179                 }
 180                 throw new Error("CONTINUE/BREAK invoked but couldn't find LoopMarker at " +
 181                                 cx.getSourceName() + ":" + cx.getLine());
 182
 183             case TRY: {
 184                 int[] jmps = (int[]) arg;
 185                 // jmps[0] is how far away the catch block is, jmps[1] is how far away the finally block is
 186                 // each can be < 0 if the specified block does not exist
 187                 cx.stack.push(new TryMarker(jmps[0] < 0 ? -1 : cx.pc + jmps[0], jmps[1] < 0 ? -1 : cx.pc + jmps[1], cx.scope));
 188                 break;
 189             }
 190
 191             case RETURN: {
 192                 Object retval = cx.stack.pop();
 193                 while(cx.stack.size() > 0) {
 194                     Object o = cx.stack.pop();
 195                     if (o instanceof TryMarker) {
 196                         if(((TryMarker)o).finallyLoc < 0) continue;
 197                         cx.stack.push(retval);
 198                         cx.stack.push(new FinallyData(RETURN));
 199                         cx.scope = ((TryMarker)o).scope;
 200                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 201                         continue OUTER;
 202                     } else if (o instanceof CallMarker) {
 203                         if (cx.scope instanceof JSTrap.JSTrapScope) {
 204                             JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)cx.scope;
 205                             if (!ts.cascadeHappened) {
 206                                 ts.cascadeHappened = true;
 207                                 JSTrap t = ts.t.next;
 208                                 while (t != null && t.f.numFormalArgs == 0) t = t.next;
 209                                 if (t == null) {
 210                                     ((JS)ts.t.trapee).put(t.name, ts.val);
 211                                     if (cx.pausecount > initialPauseCount) return null;   // we were paused
 212                                 } else {
 213                                     cx.stack.push(o);
 214                                     JSArray args = new JSArray();
 215                                     args.addElement(ts.val);
 216                                     cx.stack.push(args);
 217                                     cx.f = t.f;
 218                                     cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, ts.val);
 219                                     cx.pc = -1;
 220                                     break;
 221                                 }
 222                             }
 223                         }
 224                         cx.scope = ((CallMarker)o).scope;
 225                         cx.pc = ((CallMarker)o).pc;
 226                         cx.f = (JSFunction)((CallMarker)o).f;
 227                         cx.stack.push(retval);
 228                         continue OUTER;
 229                     }
 230                 }
 231                 throw new Error("error: RETURN invoked but couldn't find a CallMarker!");
 232             }
 233
 234             case PUT: {
 235                 Object val = cx.stack.pop();
 236                 Object key = cx.stack.pop();
 237                 Object target = cx.stack.peek();
 238                 if (target == null)
 239                     throw je("tried to put a value to the " + key + " property on the null value");
 240                 if (!(target instanceof JS))
 241                     throw je("tried to put a value to the " + key + " property on a " + target.getClass().getName());
 242                 if (key == null)
 243                     throw je("tried to assign \"" + (val==null?"(null)":val.toString()) + "\" to the null key");
 244                 JSTrap t = null;
 245                 if (target instanceof JSTrap.JSTrappable) {
 246                     t = ((JSTrap.JSTrappable)target).getTrap(val);
 247                     while (t != null && t.f.numFormalArgs == 0) t = t.next;
 248                 } else if (target instanceof JSTrap.JSTrapScope && key.equals("cascade")) {
 249                     JSTrap.JSTrapScope ts = (JSTrap.JSTrapScope)target;
 250                     t = ts.t.next;
 251                     ts.cascadeHappened = true;
 252                     while (t != null && t.f.numFormalArgs == 0) t = t.next;
 253                     if (t == null) target = ts.t.trapee;
 254                 }
 255                 if (t != null) {
 256                     cx.stack.push(new CallMarker(cx));
 257                     JSArray args = new JSArray();
 258                     args.addElement(val);
 259                     cx.stack.push(args);
 260                     cx.f = t.f;
 261                     cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, val);
 262                     cx.pc = -1;
 263                     break;
 264                 }
 265                 ((JS)target).put(key, val);
 266                 if (cx.pausecount > initialPauseCount) return null;   // we were paused
 267                 cx.stack.push(val);
 268                 break;
 269             }
 270
 271             case GET:
 272             case GET_PRESERVE: {
 273                 Object o, v;
 274                 if (op == GET) {
 275                     v = arg == null ? cx.stack.pop() : arg;
 276                     o = cx.stack.pop();
 277                 } else {
 278                     v = cx.stack.pop();
 279                     o = cx.stack.peek();
 280                     cx.stack.push(v);
 281                 }
 282                 Object ret = null;
 283                 if (v == null) throw je("tried to get the null key from " + o);
 284                 if (o == null) throw je("tried to get property \"" + v + "\" from the null value");
 285                 if (o instanceof String || o instanceof Number || o instanceof Boolean) {
 286                     ret = Internal.getFromPrimitive(o,v);
 287                     cx.stack.push(ret);
 288                     break;
 289                 } else if (o instanceof JS) {
 290                     JSTrap t = null;
 291                     if (o instanceof JSTrap.JSTrappable) {
 292                         t = ((JSTrap.JSTrappable)o).getTrap(v);
 293                         while (t != null && t.f.numFormalArgs != 0) t = t.next;
 294                     } else if (o instanceof JSTrap.JSTrapScope && v.equals("cascade")) {
 295                         t = ((JSTrap.JSTrapScope)o).t.next;
 296                         while (t != null && t.f.numFormalArgs != 0) t = t.next;
 297                         if (t == null) o = ((JSTrap.JSTrapScope)o).t.trapee;
 298                     }
 299                     if (t != null) {
 300                         cx.stack.push(new CallMarker(cx));
 301                         JSArray args = new JSArray();
 302                         cx.stack.push(args);
 303                         cx.f = t.f;
 304                         cx.scope = new JSTrap.JSTrapScope(cx.f.parentJSScope, t, null);
 305                         ((JSTrap.JSTrapScope)cx.scope).cascadeHappened = true;
 306                         cx.pc = -1;
 307                         break;
 308                     }
 309                     ret = ((JS)o).get(v);
 310                     if (cx.pausecount > initialPauseCount) return null;   // we were paused
 311                     cx.stack.push(ret);
 312                     break;
 313                 }
 314                 throw je("tried to get property " + v + " from a " + o.getClass().getName());
 315             }
 316
 317             case CALL: case CALLMETHOD: {
 318                 int numArgs = JS.toInt(arg);
 319                 JSArray arguments = null;
 320                 Object arg0 = null;
 321                 Object arg1 = null;
 322                 Object o = cx.stack.pop();
 323                 if(o == null) throw je("attempted to call null");
 324                 Object ret;
 325                 Object method = null;
 326                 if(op == CALLMETHOD) {
 327                     method = o;
 328                     if (method == null) throw new JS.Exn("cannot call the null method");
 329                     o = cx.stack.pop();
 330                     if(o instanceof String || o instanceof Number || o instanceof Boolean) {
 331                         arguments = new JSArray();
 332                         for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 333                         ret = Internal.callMethodOnPrimitive(o, method, arguments);
 334                         cx.stack.push(ret);
 335                         cx.pc += 2;  // skip the GET and CALL
 336                         break;
 337                     } else if (o instanceof JSCallable) {
 338                         cx.pc += 2;  // skip the GET and CALL
 339                         // fall through
 340                     } else {
 341                         // put the args back on the stack and let the GET followed by CALL happen
 342                         cx.stack.push(o);
 343                         cx.stack.push(method);
 344                         break;
 345                     }
 346
 347                 } else if (o instanceof JSFunction) {
 348                     // FEATURE: use something similar to call0/call1/call2 here
 349                     arguments = new JSArray();
 350                     for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 351                     cx.stack.push(new CallMarker(cx));
 352                     cx.stack.push(arguments);
 353                     cx.f = (JSFunction)o;
 354                     cx.scope = new JSScope(cx.f.parentJSScope);
 355                     cx.pc = -1;
 356                     break;
 357                 }
 358
 359                 if (!(o instanceof JSCallable)) throw new JS.Exn("can't call " + o + " @ " + cx.pc + "\n" + cx.f.dump());
 360                 JSCallable c = ((JSCallable)o);
 361                 switch(numArgs) {
 362                     case 0: ret = c.call0(method); break;
 363                     case 1: ret = c.call1(method, cx.stack.pop()); break;
 364                     case 2: { Object first = cx.stack.pop(); ret = c.call2(method, cx.stack.pop(), first); break; }
 365                     default: {
 366                         arguments = new JSArray();
 367                         for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(cx.stack.pop(), j);
 368                         ret = c.call(method, arguments);
 369                         if (cx.pausecount > initialPauseCount) return null;   // we were paused
 370                         break;
 371                     }
 372                 }
 373                 cx.stack.push(ret);
 374
 375                 break;
 376             }
 377
 378             case THROW: {
 379                 Object o = cx.stack.pop();
 380                 if(o instanceof JS.Exn) throw (JS.Exn)o;
 381                 throw new JS.Exn(o);
 382             }
 383
 384             case ASSIGN_SUB: case ASSIGN_ADD: {
 385                 Object val = cx.stack.pop();
 386                 Object old = cx.stack.pop();
 387                 Object key = cx.stack.pop();
 388                 Object obj = cx.stack.peek();
 389                 if (val instanceof JSFunction && obj instanceof JSScope) {
 390                     JSScope parent = (JSScope)obj;
 391                     while(parent.getParentJSScope() != null) parent = parent.getParentJSScope();
 392                     if (parent instanceof JSTrap.JSTrappable) {
 393                         JSTrap.JSTrappable b = (JSTrap.JSTrappable)parent;
 394                         if (op == ASSIGN_ADD) JSTrap.addTrap(b, key, (JSFunction)val);
 395                         else JSTrap.delTrap(b, key, (JSFunction)val);
 396                         // skip over the "normal" implementation of +=/-=
 397                         cx.pc += ((Integer)arg).intValue() - 1;
 398                         break;
 399                     }
 400                 }
 401                 // use the "normal" implementation
 402                 cx.stack.push(key);
 403                 cx.stack.push(old);
 404                 cx.stack.push(val);
 405                 break;
 406             }
 407
 408             case ADD: {
 409                 int count = ((Number)arg).intValue();
 410                 if(count < 2) throw new Error("this should never happen");
 411                 if(count == 2) {
 412                     // common case
 413                     Object right = cx.stack.pop();
 414                     Object left = cx.stack.pop();
 415                     if(left instanceof String || right instanceof String)
 416                         cx.stack.push(JS.toString(left).concat(JS.toString(right)));
 417                     else cx.stack.push(new Double(JS.toDouble(left) + JS.toDouble(right)));
 418                 } else {
 419                     Object[] args = new Object[count];
 420                     while(--count >= 0) args[count] = cx.stack.pop();
 421                     if(args[0] instanceof String) {
 422                         StringBuffer sb = new StringBuffer(64);
 423                         for(int i=0;i<args.length;i++) sb.append(JS.toString(args[i]));
 424                         cx.stack.push(sb.toString());
 425                     } else {
 426                         int numStrings = 0;
 427                         for(int i=0;i<args.length;i++) if(args[i] instanceof String) numStrings++;
 428                         if(numStrings == 0) {
 429                             double d = 0.0;
 430                             for(int i=0;i<args.length;i++) d += JS.toDouble(args[i]);
 431                             cx.stack.push(new Double(d));
 432                         } else {
 433                             int i=0;
 434                             StringBuffer sb = new StringBuffer(64);
 435                             if(!(args[0] instanceof String || args[1] instanceof String)) {
 436                                 double d=0.0;
 437                                 do {
 438                                     d += JS.toDouble(args[i++]);
 439                                 } while(!(args[i] instanceof String));
 440                                 sb.append(JS.toString(new Double(d)));
 441                             }
 442                             while(i < args.length) sb.append(JS.toString(args[i++]));
 443                             cx.stack.push(sb.toString());
 444                         }
 445                     }
 446                 }
 447                 break;
 448             }
 449
 450             default: {
 451                 Object right = cx.stack.pop();
 452                 Object left = cx.stack.pop();
 453                 switch(op) {
 454
 455                 case BITOR: cx.stack.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
 456                 case BITXOR: cx.stack.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
 457                 case BITAND: cx.stack.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
 458
 459                 case SUB: cx.stack.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
 460                 case MUL: cx.stack.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
 461                 case DIV: cx.stack.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
 462                 case MOD: cx.stack.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
 463
 464                 case LSH: cx.stack.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
 465                 case RSH: cx.stack.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
 466                 case URSH: cx.stack.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
 467
 468                 case LT: case LE: case GT: case GE: {
 469                     if (left == null) left = new Integer(0);
 470                     if (right == null) right = new Integer(0);
 471                     int result = 0;
 472                     if (left instanceof String || right instanceof String) {
 473                         result = left.toString().compareTo(right.toString());
 474                     } else {
 475                         result = (int)java.lang.Math.ceil(JS.toDouble(left) - JS.toDouble(right));
 476                     }
 477                     cx.stack.push(new Boolean((op == LT && result < 0) || (op == LE && result <= 0) ||
 478                                        (op == GT && result > 0) || (op == GE && result >= 0)));
 479                     break;
 480                 }
 481
 482                 case EQ:
 483                 case NE: {
 484                     Object l = left;
 485                     Object r = right;
 486                     boolean ret;
 487                     if (l == null) { Object tmp = r; r = l; l = tmp; }
 488                     if (l == null && r == null) ret = true;
 489                     else if (r == null) ret = false; // l != null, so its false
 490                     else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
 491                     else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
 492                     else if (l instanceof String) ret = r != null && l.equals(r.toString());
 493                     else ret = l.equals(r);
 494                     cx.stack.push(new Boolean(op == EQ ? ret : !ret)); break;
 495                 }
 496
 497                 default: throw new Error("unknown opcode " + op);
 498                 } }
 499             }
 500
 501         } catch(JS.Exn e) {
 502             while(cx.stack.size() > 0) {
 503                 Object o = cx.stack.pop();
 504                 if (o instanceof CatchMarker || o instanceof TryMarker) {
 505                     boolean inCatch = o instanceof CatchMarker;
 506                     if(inCatch) {
 507                         o = cx.stack.pop();
 508                         if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
 509                     }
 510                     if(!inCatch && ((TryMarker)o).catchLoc >= 0) {
 511                         // run the catch block, this will implicitly run the finally block, if it exists
 512                         cx.stack.push(o);
 513                         cx.stack.push(catchMarker);
 514                         cx.stack.push(e.getObject());
 515                         cx.scope = ((TryMarker)o).scope;
 516                         cx.pc = ((TryMarker)o).catchLoc - 1;
 517                         continue OUTER;
 518                     } else {
 519                         cx.stack.push(e);
 520                         cx.stack.push(new FinallyData(THROW));
 521                         cx.scope = ((TryMarker)o).scope;
 522                         cx.pc = ((TryMarker)o).finallyLoc - 1;
 523                         continue OUTER;
 524                     }
 525                 }
 526                 // no handler found within this func
 527                 if(o instanceof CallMarker) throw e;
 528             }
 529             throw e;
 530         } // end try/catch
 531         } // end for
 532     }
 533
 534
 535     // Debugging //////////////////////////////////////////////////////////////////////
 536
 537     public String toString() { return "JSFunction [" + sourceName + ":" + firstLine + "]"; }
 538     public String dump() {
 539         StringBuffer sb = new StringBuffer(1024);
 540         sb.append("\n" + sourceName + ": " + firstLine + "\n");
 541         for (int i=0; i < size; i++) {
 542             sb.append(i);
 543             sb.append(": ");
 544             if (op[i] < 0)
 545                 sb.append(bytecodeToString[-op[i]]);
 546             else
 547                 sb.append(codeToString[op[i]]);
 548             sb.append(" ");
 549             sb.append(arg[i] == null ? "(no arg)" : arg[i]);
 550             if((op[i] == JF || op[i] == JT || op[i] == JMP) && arg[i] != null && arg[i] instanceof Number) {
 551                 sb.append(" jump to ").append(i+((Number) arg[i]).intValue());
 552             } else  if(op[i] == TRY) {
 553                 int[] jmps = (int[]) arg[i];
 554                 sb.append(" catch: ").append(jmps[0] < 0 ? "No catch block" : ""+(i+jmps[0]));
 555                 sb.append(" finally: ").append(jmps[1] < 0 ? "No finally block" : ""+(i+jmps[1]));
 556             }
 557             sb.append("\n");
 558         }
 559         return sb.toString();
 560     }
 561
 562
 563     // Exception Stuff ////////////////////////////////////////////////////////////////
 564
 565     static class EvaluatorException extends RuntimeException { public EvaluatorException(String s) { super(s); } }
 566     static EvaluatorException ee(String s) {
 567         throw new EvaluatorException(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
 568     }
 569     static JS.Exn je(String s) {
 570         throw new JS.Exn(JSContext.getSourceName() + ":" + JSContext.getLine() + " " + s);
 571     }
 572
 573
 574     // Markers //////////////////////////////////////////////////////////////////////
 575
 576     public static class CallMarker {
 577         int pc;
 578         JSScope scope;
 579         JSFunction f;
 580         public CallMarker(JSContext cx) { pc = cx.pc + 1; scope = cx.scope; f = cx.f; }
 581     }
 582
 583     public static class CatchMarker { public CatchMarker() { } }
 584     private static CatchMarker catchMarker = new CatchMarker();
 585
 586     public static class LoopMarker {
 587         public int location;
 588         public String label;
 589         public JSScope scope;
 590         public LoopMarker(int location, String label, JSScope scope) {
 591             this.location = location;
 592             this.label = label;
 593             this.scope = scope;
 594         }
 595     }
 596     public static class TryMarker {
 597         public int catchLoc;
 598         public int finallyLoc;
 599         public JSScope scope;
 600         public TryMarker(int catchLoc, int finallyLoc, JSScope scope) {
 601             this.catchLoc = catchLoc;
 602             this.finallyLoc = finallyLoc;
 603             this.scope = scope;
 604         }
 605     }
 606     public static class FinallyData {
 607         public int op;
 608         public Object arg;
 609         public FinallyData(int op, Object arg) { this.op = op; this.arg = arg; }
 610         public FinallyData(int op) { this(op,null); }
 611     }
 612 }
 613