1 // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
4 import org.ibex.util.*;
7 /** Encapsulates a single JS interpreter (ie call stack) */
8 class Interpreter implements ByteCodes, Tokens {
9 private static final int MAX_STACK_SIZE = 512;
11 // Thread-Interpreter Mapping /////////////////////////////////////////////////////////////////////////
13 static Interpreter current() { return (Interpreter)threadToInterpreter.get(Thread.currentThread()); }
14 private static Hashtable threadToInterpreter = new Hashtable();
17 // Instance members and methods //////////////////////////////////////////////////////////////////////
19 int pausecount; ///< the number of times pause() has been invoked; -1 indicates unpauseable
20 JSFunction f = null; ///< the currently-executing JSFunction
21 JSScope scope; ///< the current top-level scope (LIFO stack via NEWSCOPE/OLDSCOPE)
22 Vec stack = new Vec(); ///< the object stack
23 int pc = 0; ///< the program counter
25 Interpreter(JSFunction f, boolean pauseable, JSArray args) {
26 stack.push(new Interpreter.CallMarker(this)); // the "root function returned" marker -- f==null
28 this.pausecount = pauseable ? 0 : -1;
29 this.scope = new JSScope(f.parentScope);
33 /** this is the only synchronization point we need in order to be threadsafe */
34 synchronized Object resume() throws JSExn {
35 Thread t = Thread.currentThread();
36 Interpreter old = (Interpreter)threadToInterpreter.get(t);
37 threadToInterpreter.put(t, this);
41 if (old == null) threadToInterpreter.remove(t);
42 else threadToInterpreter.put(t, old);
46 static int getLine() {
47 Interpreter c = Interpreter.current();
48 return c == null || c.f == null || c.pc < 0 || c.pc >= c.f.size ? -1 : c.f.line[c.pc];
51 static String getSourceName() {
52 Interpreter c = Interpreter.current();
53 return c == null || c.f == null ? null : c.f.sourceName;
56 private static JSExn je(String s) { return new JSExn(getSourceName() + ":" + getLine() + " " + s); }
58 // FIXME: double check the trap logic
59 private Object run() throws JSExn {
61 // if pausecount changes after a get/put/call, we know we've been paused
62 final int initialPauseCount = pausecount;
66 if (f == null) return stack.pop();
68 Object arg = f.arg[pc];
69 if(op == FINALLY_DONE) {
70 FinallyData fd = (FinallyData) stack.pop();
71 if(fd == null) continue OUTER; // NOP
72 if(fd.exn != null) throw fd.exn;
77 case LITERAL: stack.push(arg); break;
78 case OBJECT: stack.push(new JS()); break;
79 case ARRAY: stack.push(new JSArray(JS.toNumber(arg).intValue())); break;
80 case DECLARE: scope.declare((String)(arg==null ? stack.peek() : arg)); if(arg != null) stack.push(arg); break;
81 case TOPSCOPE: stack.push(scope); break;
82 case JT: if (JS.toBoolean(stack.pop())) pc += JS.toNumber(arg).intValue() - 1; break;
83 case JF: if (!JS.toBoolean(stack.pop())) pc += JS.toNumber(arg).intValue() - 1; break;
84 case JMP: pc += JS.toNumber(arg).intValue() - 1; break;
85 case POP: stack.pop(); break;
87 int depth = (arg == null ? 1 : JS.toInt(arg));
88 Object save = stack.elementAt(stack.size() - 1);
89 for(int i=stack.size() - 1; i > stack.size() - 1 - depth; i--)
90 stack.setElementAt(stack.elementAt(i-1), i);
91 stack.setElementAt(save, stack.size() - depth - 1);
93 case DUP: stack.push(stack.peek()); break;
94 case NEWSCOPE: scope = new JSScope(scope); break;
95 case OLDSCOPE: scope = scope.getParentScope(); break;
97 if (JS.checkAssertions && !JS.toBoolean(stack.pop()))
98 throw je("ibex.assertion.failed" /*FEATURE: line number*/); break;
99 case BITNOT: stack.push(JS.N(~JS.toLong(stack.pop()))); break;
100 case BANG: stack.push(JS.B(!JS.toBoolean(stack.pop()))); break;
101 case NEWFUNCTION: stack.push(((JSFunction)arg)._cloneWithNewParentScope(scope)); break;
105 Object o = stack.pop();
106 if (o == null) stack.push(null);
107 else if (o instanceof JS) stack.push("object");
108 else if (o instanceof String) stack.push("string");
109 else if (o instanceof Number) stack.push("number");
110 else if (o instanceof Boolean) stack.push("boolean");
111 else throw new Error("this should not happen");
116 Object o = stack.peek();
117 Enumeration e = ((JS)o).keys();
118 JSArray a = new JSArray();
119 while(e.hasMoreElements()) a.addElement(e.nextElement());
125 stack.push(new LoopMarker(pc, pc > 0 && f.op[pc - 1] == LABEL ? (String)f.arg[pc - 1] : (String)null, scope));
126 stack.push(Boolean.TRUE);
131 while(stack.size() > 0) {
132 Object o = stack.pop();
133 if (o instanceof CallMarker) je("break or continue not within a loop");
134 if (o instanceof TryMarker) {
135 if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
136 stack.push(new FinallyData(op, arg));
137 scope = ((TryMarker)o).scope;
138 pc = ((TryMarker)o).finallyLoc - 1;
141 if (o instanceof LoopMarker) {
142 if (arg == null || arg.equals(((LoopMarker)o).label)) {
143 int loopInstructionLocation = ((LoopMarker)o).location;
144 int endOfLoop = ((Integer)f.arg[loopInstructionLocation]).intValue() + loopInstructionLocation;
145 scope = ((LoopMarker)o).scope;
146 if (op == CONTINUE) { stack.push(o); stack.push(Boolean.FALSE); }
147 pc = op == BREAK ? endOfLoop - 1 : loopInstructionLocation;
152 throw new Error("CONTINUE/BREAK invoked but couldn't find LoopMarker at " +
153 getSourceName() + ":" + getLine());
156 int[] jmps = (int[]) arg;
157 // jmps[0] is how far away the catch block is, jmps[1] is how far away the finally block is
158 // each can be < 0 if the specified block does not exist
159 stack.push(new TryMarker(jmps[0] < 0 ? -1 : pc + jmps[0], jmps[1] < 0 ? -1 : pc + jmps[1], this));
164 Object retval = stack.pop();
165 while(stack.size() > 0) {
166 Object o = stack.pop();
167 if (o instanceof TryMarker) {
168 if(((TryMarker)o).finallyLoc < 0) continue;
170 stack.push(new FinallyData(RETURN));
171 scope = ((TryMarker)o).scope;
172 pc = ((TryMarker)o).finallyLoc - 1;
174 } else if (o instanceof CallMarker) {
175 if (o instanceof TrapMarker) { // handles return component of a read trap
176 TrapMarker tm = (TrapMarker) o;
177 boolean cascade = tm.t.writeTrap() && !tm.cascadeHappened && !JS.toBoolean(retval);
180 while(t != null && t.readTrap()) t = t.next;
184 JSArray args = new JSArray();
185 args.addElement(tm.val);
188 scope = new JSScope(f.parentScope);
192 tm.trapee.put(tm.key,tm.val);
196 scope = ((CallMarker)o).scope;
197 pc = ((CallMarker)o).pc - 1;
198 f = (JSFunction)((CallMarker)o).f;
200 if (pausecount > initialPauseCount) { pc++; return null; } // we were paused
204 throw new Error("error: RETURN invoked but couldn't find a CallMarker!");
208 Object val = stack.pop();
209 Object key = stack.pop();
210 Object target = stack.peek();
212 throw je("tried to put a value to the " + key + " property on the null value");
213 if (!(target instanceof JS))
214 throw je("tried to put a value to the " + key + " property on a " + target.getClass().getName());
216 throw je("tried to assign \"" + (val==null?"(null)":val.toString()) + "\" to the null key");
218 if (target instanceof String || target instanceof Number || target instanceof Boolean) throw new JSExn("can't put values to primitives");
219 if(!(target instanceof JS)) throw new Error("should never happen");
222 TrapMarker tm = null;
223 if(target instanceof JSScope && key.equals("cascade")) {
226 for(i=stack.size()-1;i>=0;i--) if((o = stack.elementAt(i)) instanceof CallMarker) break;
227 if(i==0) throw new Error("didn't find a call marker while doing cascade");
228 if(o instanceof TrapMarker) {
232 tm.cascadeHappened = true;
234 if(t.readTrap()) throw new JSExn("can't put to cascade in a read trap");
236 while(t != null && t.readTrap()) t = t.next;
239 if(tm == null) { // didn't find a trap marker, try to find a trap
240 t = target instanceof JSScope ? t = ((JSScope)target).top().getTrap(key) : ((JS)target).getTrap(key);
241 while(t != null && t.readTrap()) t = t.next;
247 stack.push(new TrapMarker(this,t,(JS)target,key,val));
248 JSArray args = new JSArray();
249 args.addElement(val);
252 scope = new JSScope(f.parentScope);
256 ((JS)target).put(key,val);
257 if (pausecount > initialPauseCount) { pc++; return null; } // we were paused
266 key = arg == null ? stack.pop() : arg;
267 target = stack.pop();
270 target = stack.peek();
274 if (key == null) throw je("tried to get the null key from " + target);
275 if (target == null) throw je("tried to get property \"" + key + "\" from the null object");
276 if (target instanceof String || target instanceof Number || target instanceof Boolean) {
277 ret = getFromPrimitive(target,key);
281 if(!(target instanceof JS)) throw new Error("should never happen");
284 TrapMarker tm = null;
285 if(target instanceof JSScope && key.equals("cascade")) {
288 for(i=stack.size()-1;i>=0;i--) if((o = stack.elementAt(i)) instanceof CallMarker) break;
289 if(i==0) throw new Error("didn't find a call marker while doing cascade");
290 if(o instanceof TrapMarker) {
295 if(t.writeTrap()) throw new JSExn("can't do a write cascade in a read trap");
297 while(t != null && t.writeTrap()) t = t.next;
298 if(t != null) tm.cascadeHappened = true;
301 if(tm == null) { // didn't find a trap marker, try to find a trap
302 t = target instanceof JSScope ? t = ((JSScope)target).top().getTrap(key) : ((JS)target).getTrap(key);
303 while(t != null && t.writeTrap()) t = t.next;
307 stack.push(new TrapMarker(this,t,(JS)target,key,null));
308 stack.push(new JSArray());
310 scope = new JSScope(f.parentScope);
314 ret = ((JS)target).get(key);
315 if (ret == JS.METHOD) ret = new Stub((JS)target, key);
317 if (pausecount > initialPauseCount) { pc++; return null; } // we were paused
322 case CALL: case CALLMETHOD: {
323 int numArgs = JS.toInt(arg);
324 Object method = null;
326 Object object = stack.pop();
328 if (op == CALLMETHOD) {
329 if (object == JS.METHOD) {
330 method = stack.pop();
331 object = stack.pop();
332 } else if (object == null) {
333 Object name = stack.pop();
335 throw new JSExn("function '"+name+"' not found");
341 Object[] rest = numArgs > 3 ? new Object[numArgs - 3] : null;
342 for(int i=numArgs - 1; i>2; i--) rest[i-3] = stack.pop();
343 Object a2 = numArgs <= 2 ? null : stack.pop();
344 Object a1 = numArgs <= 1 ? null : stack.pop();
345 Object a0 = numArgs <= 0 ? null : stack.pop();
347 if (object instanceof String || object instanceof Number || object instanceof Boolean) {
348 ret = callMethodOnPrimitive(object, method, a0, a1, a2, null, numArgs);
350 } else if (object instanceof JSFunction) {
351 // FIXME: use something similar to call0/call1/call2 here
352 JSArray arguments = new JSArray();
353 for(int i=0; i<numArgs; i++) arguments.addElement(i==0?a0:i==1?a1:i==2?a2:rest[i-3]);
354 stack.push(new CallMarker(this));
355 if(stack.size() > MAX_STACK_SIZE) throw new JSExn("stack overflow");
356 stack.push(arguments);
357 f = (JSFunction)object;
358 scope = new JSScope(f.parentScope);
362 } else if (object instanceof JS) {
364 ret = method == null ? c.call(a0, a1, a2, rest, numArgs) : c.callMethod(method, a0, a1, a2, rest, numArgs);
367 throw new JSExn("can't call a " + object + " @" + pc + "\n" + f.dump());
370 if (pausecount > initialPauseCount) { pc++; return null; }
376 throw new JSExn(stack.pop(), stack, f, pc, scope);
380 final Grammar r = (Grammar)arg;
381 final JSScope final_scope = scope;
382 Grammar r2 = new Grammar() {
383 public int match(String s, int start, Hash v, JSScope scope) throws JSExn {
384 return r.match(s, start, v, final_scope);
386 public int matchAndWrite(String s, int start, Hash v, JSScope scope, String key) throws JSExn {
387 return r.matchAndWrite(s, start, v, final_scope, key);
389 public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
391 r.matchAndWrite((String)a0, 0, v, final_scope, "foo");
395 Object obj = stack.pop();
396 if (obj != null && obj instanceof Grammar) r2 = new Grammar.Alternative((Grammar)obj, r2);
401 case ADD_TRAP: case DEL_TRAP: {
402 Object val = stack.pop();
403 Object key = stack.pop();
404 Object obj = stack.peek();
405 // A trap addition/removal
407 if(js instanceof JSScope) {
408 JSScope s = (JSScope) js;
409 while(s.getParentScope() != null) {
410 if(s.has(key)) throw new JSExn("cannot trap a variable that isn't at the top level scope");
411 s = s.getParentScope();
416 // if(!js.has(key)) throw new JSExn("tried to add/remove a trap from an uninitialized variable");
417 if(op == ADD_TRAP) js.addTrap(key, (JSFunction)val);
418 else js.delTrap(key, (JSFunction)val);
422 case ASSIGN_SUB: case ASSIGN_ADD: {
423 Object val = stack.pop();
424 Object key = stack.pop();
425 Object obj = stack.peek();
426 // The following setup is VERY important. The generated bytecode depends on the stack
427 // being setup like this (top to bottom) KEY, OBJ, VAL, KEY, OBJ
436 int count = ((Number)arg).intValue();
437 if(count < 2) throw new Error("this should never happen");
440 Object right = stack.pop();
441 Object left = stack.pop();
442 if(left instanceof String || right instanceof String)
443 stack.push(JS.toString(left).concat(JS.toString(right)));
444 else stack.push(JS.N(JS.toDouble(left) + JS.toDouble(right)));
446 Object[] args = new Object[count];
447 while(--count >= 0) args[count] = stack.pop();
448 if(args[0] instanceof String) {
449 StringBuffer sb = new StringBuffer(64);
450 for(int i=0;i<args.length;i++) sb.append(JS.toString(args[i]));
451 stack.push(sb.toString());
454 for(int i=0;i<args.length;i++) if(args[i] instanceof String) numStrings++;
455 if(numStrings == 0) {
457 for(int i=0;i<args.length;i++) d += JS.toDouble(args[i]);
461 StringBuffer sb = new StringBuffer(64);
462 if(!(args[0] instanceof String || args[1] instanceof String)) {
465 d += JS.toDouble(args[i++]);
466 } while(!(args[i] instanceof String));
467 sb.append(JS.toString(JS.N(d)));
469 while(i < args.length) sb.append(JS.toString(args[i++]));
470 stack.push(sb.toString());
478 if(op == BITOR) throw new Error("pc: " + pc + " of " + f);
479 Object right = stack.pop();
480 Object left = stack.pop();
483 case BITOR: stack.push(JS.N(JS.toLong(left) | JS.toLong(right))); break;
484 case BITXOR: stack.push(JS.N(JS.toLong(left) ^ JS.toLong(right))); break;
485 case BITAND: stack.push(JS.N(JS.toLong(left) & JS.toLong(right))); break;
487 case SUB: stack.push(JS.N(JS.toDouble(left) - JS.toDouble(right))); break;
488 case MUL: stack.push(JS.N(JS.toDouble(left) * JS.toDouble(right))); break;
489 case DIV: stack.push(JS.N(JS.toDouble(left) / JS.toDouble(right))); break;
490 case MOD: stack.push(JS.N(JS.toDouble(left) % JS.toDouble(right))); break;
492 case LSH: stack.push(JS.N(JS.toLong(left) << JS.toLong(right))); break;
493 case RSH: stack.push(JS.N(JS.toLong(left) >> JS.toLong(right))); break;
494 case URSH: stack.push(JS.N(JS.toLong(left) >>> JS.toLong(right))); break;
496 case LT: case LE: case GT: case GE: {
497 if (left == null) left = JS.N(0);
498 if (right == null) right = JS.N(0);
500 if (left instanceof String || right instanceof String) {
501 result = JS.toString(left).compareTo(JS.toString(right));
503 result = (int)java.lang.Math.ceil(JS.toDouble(left) - JS.toDouble(right));
505 stack.push(JS.B((op == LT && result < 0) || (op == LE && result <= 0) ||
506 (op == GT && result > 0) || (op == GE && result >= 0)));
512 // FIXME: This is not correct, see ECMA-262 11.9.3
516 if (l == null) { Object tmp = r; r = l; l = tmp; }
517 if (l == null && r == null) ret = true;
518 else if (r == null) ret = false; // l != null, so its false
519 else if (l instanceof Boolean) ret = JS.B(JS.toBoolean(r)).equals(l);
520 else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
521 else if (l instanceof String) ret = r != null && l.equals(JS.toString(r));
522 else ret = l.equals(r);
523 stack.push(JS.B(op == EQ ? ret : !ret)); break;
526 default: throw new Error("unknown opcode " + op);
531 while(stack.size() > 0) {
532 Object o = stack.pop();
533 if (o instanceof CatchMarker || o instanceof TryMarker) {
534 boolean inCatch = o instanceof CatchMarker;
537 if(((TryMarker)o).finallyLoc < 0) continue; // no finally block, keep going
539 if(!inCatch && ((TryMarker)o).catchLoc >= 0) {
540 // run the catch block, this will implicitly run the finally block, if it exists
542 stack.push(catchMarker);
543 stack.push(e.getObject());
544 f = ((TryMarker)o).f;
545 scope = ((TryMarker)o).scope;
546 pc = ((TryMarker)o).catchLoc - 1;
549 stack.push(new FinallyData(e));
550 f = ((TryMarker)o).f;
551 scope = ((TryMarker)o).scope;
552 pc = ((TryMarker)o).finallyLoc - 1;
564 // Markers //////////////////////////////////////////////////////////////////////
566 public static class CallMarker {
570 public CallMarker(Interpreter cx) { pc = cx.pc + 1; scope = cx.scope; f = cx.f; }
573 public static class TrapMarker extends CallMarker {
578 boolean cascadeHappened;
579 public TrapMarker(Interpreter cx, Trap t, JS trapee, Object key, Object val) {
582 this.trapee = trapee;
588 public static class CatchMarker { }
589 private static CatchMarker catchMarker = new CatchMarker();
591 public static class LoopMarker {
594 public JSScope scope;
595 public LoopMarker(int location, String label, JSScope scope) {
596 this.location = location;
601 public static class TryMarker {
603 public int finallyLoc;
604 public JSScope scope;
606 public TryMarker(int catchLoc, int finallyLoc, Interpreter cx) {
607 this.catchLoc = catchLoc;
608 this.finallyLoc = finallyLoc;
609 this.scope = cx.scope;
613 public static class FinallyData {
617 public FinallyData(int op) { this(op,null); }
618 public FinallyData(int op, Object arg) { this.op = op; this.arg = arg; }
619 public FinallyData(JSExn exn) { this.exn = exn; } // Just throw this exn
623 // Operations on Primitives //////////////////////////////////////////////////////////////////////
625 static Object callMethodOnPrimitive(Object o, Object method, Object arg0, Object arg1, Object arg2, Object[] rest, int alength) throws JSExn {
626 if (method == null || !(method instanceof String) || "".equals(method))
627 throw new JSExn("attempt to call a non-existant method on a primitive");
629 if (o instanceof Number) {
631 case "toFixed": throw new JSExn("toFixed() not implemented");
632 case "toExponential": throw new JSExn("toExponential() not implemented");
633 case "toPrecision": throw new JSExn("toPrecision() not implemented");
635 int radix = alength >= 1 ? JS.toInt(arg0) : 10;
636 return Long.toString(((Number)o).longValue(),radix);
639 } else if (o instanceof Boolean) {
640 // No methods for Booleans
641 throw new JSExn("attempt to call a method on a Boolean");
644 String s = JS.toString(o);
645 int slength = s.length();
648 int a = alength >= 1 ? JS.toInt(arg0) : 0;
649 int b = alength >= 2 ? JS.toInt(arg1) : slength;
650 if (a > slength) a = slength;
651 if (b > slength) b = slength;
654 if (a > b) { int tmp = a; a = b; b = tmp; }
655 return s.substring(a,b);
658 int start = alength >= 1 ? JS.toInt(arg0) : 0;
659 int len = alength >= 2 ? JS.toInt(arg1) : Integer.MAX_VALUE;
660 if (start < 0) start = slength + start;
661 if (start < 0) start = 0;
662 if (len < 0) len = 0;
663 if (len > slength - start) len = slength - start;
664 if (len <= 0) return "";
665 return s.substring(start,start+len);
668 int p = alength >= 1 ? JS.toInt(arg0) : 0;
669 if (p < 0 || p >= slength) return "";
670 return s.substring(p,p+1);
673 int p = alength >= 1 ? JS.toInt(arg0) : 0;
674 if (p < 0 || p >= slength) return JS.N(Double.NaN);
675 return JS.N(s.charAt(p));
678 StringBuffer sb = new StringBuffer(slength*2).append(s);
679 for(int i=0;i<alength;i++) sb.append(i==0?arg0:i==1?arg1:i==2?arg2:rest[i-3]);
680 return sb.toString();
683 String search = alength >= 1 ? JS.toString(arg0) : "null";
684 int start = alength >= 2 ? JS.toInt(arg1) : 0;
685 // Java's indexOf handles an out of bounds start index, it'll return -1
686 return JS.N(s.indexOf(search,start));
688 case "lastIndexOf": {
689 String search = alength >= 1 ? JS.toString(arg0) : "null";
690 int start = alength >= 2 ? JS.toInt(arg1) : 0;
691 // Java's indexOf handles an out of bounds start index, it'll return -1
692 return JS.N(s.lastIndexOf(search,start));
694 case "match": return JSRegexp.stringMatch(s,arg0);
695 case "replace": return JSRegexp.stringReplace(s,arg0,arg1);
696 case "search": return JSRegexp.stringSearch(s,arg0);
697 case "split": return JSRegexp.stringSplit(s,arg0,arg1,alength);
698 case "toLowerCase": return s.toLowerCase();
699 case "toUpperCase": return s.toUpperCase();
700 case "toString": return s;
702 int a = alength >= 1 ? JS.toInt(arg0) : 0;
703 int b = alength >= 2 ? JS.toInt(arg1) : slength;
704 if (a < 0) a = slength + a;
705 if (b < 0) b = slength + b;
708 if (a > slength) a = slength;
709 if (b > slength) b = slength;
710 if (a > b) return "";
711 return s.substring(a,b);
714 throw new JSExn("Attempted to call non-existent method: " + method);
717 static Object getFromPrimitive(Object o, Object key) throws JSExn {
718 boolean returnJS = false;
719 if (o instanceof Boolean) {
720 throw new JSExn("Booleans do not have properties");
721 } else if (o instanceof Number) {
722 if (key.equals("toPrecision") || key.equals("toExponential") || key.equals("toFixed"))
726 // the string stuff applies to everything
727 String s = JS.toString(o);
729 // this is sort of ugly, but this list should never change
730 // These should provide a complete (enough) implementation of the ECMA-262 String object
733 case "length": return JS.N(s.length());
734 case "substring": returnJS = true; break;
735 case "charAt": returnJS = true; break;
736 case "charCodeAt": returnJS = true; break;
737 case "concat": returnJS = true; break;
738 case "indexOf": returnJS = true; break;
739 case "lastIndexOf": returnJS = true; break;
740 case "match": returnJS = true; break;
741 case "replace": returnJS = true; break;
742 case "search": returnJS = true; break;
743 case "slice": returnJS = true; break;
744 case "split": returnJS = true; break;
745 case "toLowerCase": returnJS = true; break;
746 case "toUpperCase": returnJS = true; break;
747 case "toString": returnJS = true; break;
748 case "substr": returnJS = true; break;
752 final Object target = o;
753 final String method = JS.toString(o);
755 public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
756 if (nargs > 2) throw new JSExn("cannot call that method with that many arguments");
757 return callMethodOnPrimitive(target, method, a0, a1, a2, rest, nargs);
764 private static class Stub extends JS {
765 private Object method;
767 public Stub(JS obj, Object method) { this.obj = obj; this.method = method; }
768 public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn {
769 return ((JS)obj).callMethod(method, a0, a1, a2, rest, nargs);