Invalidate callsite

[Isaiah Peng]

@szegedia
I tried your suggestion, but the guards are not triggered, turns out the
problem is with the generators, for which support for "wide call"
invocations is not yet implemented. :(

Thanks for your help.
Isaiah

On Tue, 1 Aug 2017 at 14:38 Attila Szegedi <szegedia at gmail.com> wrote:

> I’d suggest that when findCallMethod is invoked so that in the LinkRequest
> arguments, there’s a string argument, you produce a GuardedInvocation with
> the first method and a guard that checks if the relevant argument is a
> string, and when invoked with a PyObject, then produce a GuardedInvocation
> with the second method and a guard that checks if argument 3 is a PyObject.
>
> Attila.
>
> > On 01 Aug 2017, at 13:43, Isaiah Peng <issaria at gmail.com> wrote:
> >
> > Hi guys,
> >
> > My name is Isaiah, I'm currently trying to implement invokedynamic for my
> > Python 3 implementation. Everything went quite well until I encountered a
> > `ClassCastException` which I don't know how to fix.
> >
> > Here is my theory: there are two method calls that has the same arity,
> with
> > signatures of:
> >
> > `(LPyObject;LThreadState;[LPyObject;LString;)LPyObject`
> > and
> > `(LPyObject;LThreadState;LPyObject;LPyObject)LPyObject`
> >
> > The former is for methods that take vararg and keyword arguments, the
> later
> > is for methods that take two arguments. The stacktrace is as following:
> >
> > java.lang.ClassCastException: Cannot cast [Ljava.lang.String; to
> > org.python.core.PyObject
> >
> >        at java.base/java.lang.Class.cast(Class.java:3578)
> >        at contextlib_jython_36.__init__$12(contextlib:67)
> >        at org.python.core.Py.runCode(Py.java:1663)
> >        at org.python.core.PyTableCode.call(PyTableCode.java:404)
> >        at org.python.core.PyTableCode.call(PyTableCode.java:382)
> >        at org.python.core.PyFunction.__call__(PyFunction.java:442)
> >        at
> > org.python.core.PyMethod.instancemethod___call__(PyMethod.java:237)
> >        at org.python.core.PyMethod.__call__(PyMethod.java:228)
> >        at org.python.core.PyMethod.__call__(PyMethod.java:223)
> >        at org.python.core.Deriveds.dispatch__init__(Deriveds.java:19)
> >        at
> >
> org.python.core.PyObjectDerived.dispatch__init__(PyObjectDerived.java:940)
> >        at org.python.core.PyType.type___call__(PyType.java:1675)
> >        at org.python.core.PyType$type___call___exposer.__call__(Unknown
> > Source)
> >        at org.python.core.PyTypeDerived.__call__(PyTypeDerived.java:831)
> >        at org.python.core.PyObject.__call__(PyObject.java:506)
> >        at org.python.core.PyObject.__call__(PyObject.java:510)
> >        at contextlib_jython_36.helper$17(contextlib:159)
> >
> > The GuardedInvocation returned from the linker is like:
> >
> > `return new GuardedInvocation(mh, null, new SwitchPoint[0],
> > ClassCastException.class);`
> >
> > It seems to be able to catch the class cast exception for the receiver
> but
> > not for arguments. I create a similar call path and the function works
> > fine, so I thought the cause could be the callsite is not invalidated.
> >
> > My question is: Is my guess correct? if so why does it reuse the callsite
> > when the signatures are different? and how to create a guard for such
> case?
> >
> > The source code can be found here:
> >
> >
> https://bitbucket.org/jylang/jylang/src/e0c64d17b21db7784c75892424cae09f9faa07d3/src/org/python/core/PyFunction.java?at=indy&fileviewer=file-view-default#PyFunction.java-513
> >
> > Thanks in advance,
> > Isaiah Peng
>
>