405654 - Execution exits interpreter on Function.apply and Function.call

Status: RESOLVED FIXED

(Rhino Graveyard :: Core, defect)

Description

[Attila Szegedi]

when f.apply() or f.call() are invoked from the interpreter, the interpreter will call into Java code for IdFunctionObject.call() which will initiate another interpreter loop in case f is an interpreted function. This breaks continuations captured within the f.apply() or f.call().

The interpreter loop should recognize the special cases of Function.apply and Function.call, and if they are invoked on an InterpretedFunction within the same security domain, then execute the applied/called function within the current interpreter loop.

Comment 1

[Attila Szegedi]

Unfortunately, this gets worse. apply() and call() are not the only cases of a JS->Java->JS transition. 

There is the case of a JS-aware Java object, or a JavaAdapter being passed to Java code. However, since these require that the developer explicitly meddle with Java-specific functionality, we can accept this as a limitation. 

However, there are further pure-JS cases as well, namely all JS 1.6 array iterator methods: Array.every(), Array. filter(), Array. forEach(), Array. map(), Array. some(). It is clearly not feasible to treat these as special cases in the interpreter. It might be possible to provide an implementation of them written in JS, and when someone needs continuations support through these invocations, then redefine them using

 Array.prototype.every = function(fun /*, thisp*/)
 {
    var len = this.length;
    if (typeof fun != "function")
      throw new TypeError();

    var thisp = arguments[1];
    for (var i = 0; i < len; i++)
    {
      if (i in this &&
          !fun.call(thisp, this[i], i, this))
        return false;
    }

    return true;
  };

and similar -- code seen here was lifted from <http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference:Objects:Array:every>

Also, unrelated to these, exotic stuff, like invoking apply on apply itself etc. clearly won't work as expected...

Comment 2

[Attila Szegedi]

cvs ci -m "Fix for Bug 405654 – Execution exits interpreter on Function.apply and Function.call" -l "/Rhino/src/org/mozilla/javascript/BaseFunction.java" "/Rhino/src/org/mozilla/javascript/ScriptRuntime.java" "/Rhino/src/org/mozilla/javascript/Interpreter.java"
    Checking in src/org/mozilla/javascript/BaseFunction.java;
    /cvsroot/mozilla/js/rhino/src/org/mozilla/javascript/BaseFunction.java,v  <--  BaseFunction.java
    new revision: 1.65; previous revision: 1.64
    done
    Checking in src/org/mozilla/javascript/ScriptRuntime.java;
    /cvsroot/mozilla/js/rhino/src/org/mozilla/javascript/ScriptRuntime.java,v  <--  ScriptRuntime.java
    new revision: 1.284; previous revision: 1.283
    done
    Checking in src/org/mozilla/javascript/Interpreter.java;
    /cvsroot/mozilla/js/rhino/src/org/mozilla/javascript/Interpreter.java,v  <--  Interpreter.java
    new revision: 1.338; previous revision: 1.337
    done