[foreign] RFR: refresh layout grammar

[Maurizio Cimadamore]

On 23/05/18 19:10, Henry Jen wrote:
>
>> On May 23, 2018, at 9:46 AM, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
>>
>> Hi,
>> I've put together a change which tweaks the grammar of layout descriptions used in annotations to correspond to what's described here [1].
>>
>> The big changes are in DescriptorParser, which now has to understand the new grammar, and also in TestDescriptorGrammar, which has to combinatorially generate sentences of the new grammar.
>>
>> All the other tedious changes are test changes, required to go from the old to the new grammar; I've adhered to the following rules:
>>
>> 'b' -> ‘u8'
> b is a bit, so should it be u1?
uhm - booleans don't exist in C, so typically a byte will be allocated 
holding a 1 or a 0. You can think of it as u8[u1(value)u7(padding)] if 
you want, but the results are the same?
> o is octet, which is the byte and should be u8.
ok, I haven't seen octets around in existing tests
>
>> 'c' -> ‘i8'
> char is either signed or unsigned depends on platform. Since we are targeting x64 for now, unsigned is correct.
ok

Maurizio
>
>> 's' -> 'i16'
>> 'i' -> 'i32'
>> 'l' -> 'i64'
>> 'q' -> 'i64'
>>
>> Also note that in the new grammar capital letter denote big-endiannes, while in the old one they meant unsigned-ness.
>>
>> There's a trivia in the DoubleUpcall test, which was using 'unsigned double' ('D') - not sure why…
> Hmm, not sure.
>
> Cheers,
> Henry
>
>> Webrev here:
>>
>> http://cr.openjdk.java.net/~mcimadamore/panama/layout-grammar-refresh/
>>
>> P.S.
>> Might be useful to give it a spin on Mac and see if UnixSystemTest works (the layout conversion was not very trivial w/o jextract support :-))
>>
>> Cheers
>>
>> Maurizio
>>
>>