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

[Lindenmaier, Goetz]

Hi Mandy, 

that sounds good!

It makes sure my part still reaches jdk 11. Adding the module info
later is a useful further improvement then.

I'll post a new webrev once Lois' change JDK-8202605 pops up 
in the repo.

Best regards,
  Goetz.

> -----Original Message-----
> From: mandy chung [mailto:mandy.chung at oracle.com]
> Sent: Montag, 18. Juni 2018 21:24
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; 'Lois Foltan'
> <lois.foltan 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,
> 
> Lois, Harold, and I discussed briefly how to help this patch move
> forward independent of JDK-8169559 (that intends to replace
> Klass::class_loader_and_module_name with a better utility method).
> 
> The format we propose is to change from:
>    $C1 cannot access its superinterface $C2
> 
> TO:
>    $C1 cannot access its superinterface $C2 ($C1 is in $M1 of loader
> $L1; $C2 is in $M2 of loader $L2)
> 
> The above will depend on JDK-8169559.
> 
> The intermediate step is for JDK-8199940 to append the loader info in IAE:
>   $C1 cannot access its superinterface $C2 ($C1 is in loader $L1; $C2 is
> in loader $L2)
> 
> This will depend on the new loader_name_and_id function introduced by
> JDK-8202605. JDK-8169559 can add the module info in the exception
> messages as a follow-up issue (these IAEs don't have any module info in
> the current implementation anyway.)
> 
> For IAE in member access, I suggest to rephrase the message from:
> 
> tried to access method test.IllegalAccessErrorTest.iae4_m()V from class
> test.Runner4
> 
> TO:
> 
> class test.Runner4 tried to access private method
> test.IllegalAccessErrorTest.iae4_m()V (test.Runner4  is in loader 'app';
> test.IllegalAccessErrorTest. is in loader 'app')
> 
> What do you think?
> Mandy
> 
> On 5/24/18 3:15 PM, mandy chung wrote:
> >
> >
> > On 5/24/18 2:12 PM, Lindenmaier, Goetz wrote:
> >> Hi Lois,
> >>
> >> I changed  the code as agreed:
> >> http://cr.openjdk.java.net/~goetz/wr18/8199940-exMsg-
> IllegalAccess/02/
> :
> 
> > 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)
> >
> > 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)
> >
> > if the loader name is highly desirable (I'm unsure yet):
> >
> > 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