spec clarification: empty default view

[Alex Buckley]

On 1/23/2012 5:57 PM, Jonathan Gibbons wrote:
> In a ModuleProvides_attribute, does there have to be an entry for the
> default view, even it it would be completely empty?

Attributes should only store what exists. The language and the module 
system might well say there is logically a default view which is empty, 
but we traditionally don't "do" dummy attributes with zero-length tables 
in the ClassFile. (A ClassFile format checker must be able to handle 
them, but a Java compiler is not obligated to produce it.)

So, if a module declaration consists of just 'requires' clauses and 
exports nothing, has no aliases, no friends, and no entrypoint, then I 
would say no ModuleProvides attribute is needed at all.

Adding one non-default view to that module declaration would prompt a 
ModuleProvides attribute, but I don't think a default view needs to 
spring into the physical representation too. Each physical view is 
standalone in ModuleProvides.

Alex