RFR(M): 8199940: Print more information about class loaders in IllegalAccessErrors.

[Lindenmaier, Goetz]

Hi Lois, 

any progress on this issue? I would like to still get this into jdk11 ...

Best regards,
  Goetz.

> -----Original Message-----
> From: Lois Foltan [mailto:lois.foltan at oracle.com]
> Sent: Freitag, 1. Juni 2018 15:26
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; mandy chung
> <mandy.chung at oracle.com>
> Cc: hotspot-runtime-dev at openjdk.java.net
> Subject: Re: RFR(M): 8199940: Print more information about class loaders in
> IllegalAccessErrors.
> 
> Hi Goetz,
> 
> Again, thank you for making the change to the IAE error message to
> include the class loader name.  Due to the recommendation of differing
> formats, we are discussing this internally to make sure the format we
> suggest is a common format for not just IAE, but for all error messages
> that may be changed in the future to include the class loader name.
> Appreciate your patience with this and hopefully should have an agreed
> upon proposal shortly.
> 
> Thanks,
> Lois
> 
> On 5/25/2018 2:39 AM, Lindenmaier, Goetz wrote:
> > Hi Mandy,
> >
> > thanks for looking at my change!
> >
> >>> I changed  the code as agreed:
> >>> http://cr.openjdk.java.net/~goetz/wr18/8199940-exMsg-
> IllegalAccess/02/
> >>> The message is now:
> >>> "class test.IAE1_B cannot access its superinterface test.IAE1_A"
> >>> if there are no names in the loaders.
> >> For this IAE, it should include the module in the message as:
> >> class test.IAE1_B (in unnamed module @0x3d04a311) cannot access its
> >> superinterface test.IAE1_A (in module m1)
> > Wouldn't it be better if we extend class_loader_and_module_name() to
> print
> > module at 0x3d04a311/test.IAE1_B if we pass a flag 'verbose' or the like?
> > I think that is the  way Lois would prefer.
> > If the modules differ, we could add some more text:
> >
> > "class module at 0x3d04a311/test.IAE1_B cannot access its superinterface
> m1/test.IAE1_A because they are in different modules"
> >
> > One still would not know this was caused by using different loaders in the
> implementation ...
> >
> >>> How should anybody know from the message that the classes were
> >>> loaded by different loaders? It gives no hint at all to the cause of
> >>> the problem.
> >> The above is one example that does not have the loader name.
> >> Each module is defined to one loader so it can derive from
> >> the module info.
> >>
> >>>> java.lang.IllegalAccessError: tried to access private method
> >>>> MySameClassLoader/m2x/p2.c2.method2()V from class
> >>>> MySameClassLoader/m1x/p1.c1
> >> What about other formats:
> >>
> >> tried to access private method p2.c2.method2()V (in module m2x) from
> >> class p1.c1 (in module m1x)
> > Hmm, as above, Lois wants me to use class_loader_and_module_name().
> > Also, in none of my examples, modules have a name or are handled by
> > the code in any way.  So it's quite misleading if the modules are reported
> > as issue while it's in first place caused by the class loaders (which might
> > induce modules that then cause the error.)
> >
> >> if the loader name is highly desirable (I'm unsure yet):
> > Yes it is. It can be set by the developer and if he does so it should be
> printed.
> > The modules here seem to be generated automatically.  Maybe they
> should
> > derive their names from the class loaders if the relation between them is
> > that obvious?
> >
> >> tried to access private method p2.c2.method2()V (in module m2x defined
> >> to MySameClassLoader) from class p1.c1 (in module m1x defined to
> >> MySameClassLoader)
> >>
> >> Mandy