Review request: update javac to properly output mandated parameters in MethodParameters attributes

[maurizio cimadamore]

On 07-Feb-13 8:29 PM, maurizio cimadamore wrote:
> On 07-Feb-13 7:32 PM, Alex Buckley wrote:
>> In http://cr.openjdk.java.net/~abuckley/8misc.pdf, see JLS 13.1 for 
>> new information about explicitly and implicitly declared constructs. 
>> Also, see JVMS 4.7.22 for how a compiler emitting class files can 
>> mark formal parameters as required by JLS 13.1. 
> Anyway thanks for pointing me out at 13.1 - I missed that on a first 
> scan.
>
> It would seem that the spec is not defining (on top of my head - there 
> are probably others):
>
> *) (effectively) final variables passed in to inner classes (javac 
> only does that for reference-types as others are just constants that 
> can be produced on the stack at will)
> *) I believe javac's generated enum constructor has an additional 
> parameter accepting the ordinal
Another case - private constructors:

class Outer {
     class Inner {
         private Inner() { }
     }

     Inner i = new Inner();
}

javac will append to the Inner's constructor an extra argument called 
'accessTag' - which is essentially a type token.

Again, in this case I don't think it would be fair to specify this as 
'implicitly declared' as there's a lot of room to manouvre.

Maurizio
>
> It feels like the second should probably be spec'd - the first I don't 
> know - I see  a lot of implementation room on that one.
>
> In any case, the implementation problem remains: it doesn't 
> distinguish between impl-only parameters and 'implicitly declared' 
> ones. It just takes all parameters that do not have a correspondent in 
> the source code and put them in the same place.
>
> Maurizio
>