[foreign] RFR: improved macro parser

[Sundararajan Athijegannathan]

"static JShell" instance is used in MacroParser. I think jextract 
implements ToolProvider. If we create more than one jextract tool 
instance & use it, will it be a problem?

-Sundar

On 02/06/18, 2:51 AM, Maurizio Cimadamore wrote:
> Hi,
> this webrev adds a new way of parsing object-like macros which relies 
> on the jshell API; defined macros are turned into jshell var 
> declaration - e.g.
>
> #define FOO 12
>
> is turned into
>
> 'var FOO = 12;'
>
> All macros are entered into a jshell context, and this allows to 
> 'resolve' macro names so that we can handle common cases like:
>
> #define MAX 43
> #define MIN (-MAX)
>
> Thanks to the jshell API the new code is not too complex, and it 
> handles the vast majority of constant-like macros. Of course we need a 
> more general fallback for macros (esp. function-like), e.g. I'm under 
> no illusion that this will work in all cases, but this looks like a 
> good improvement over the current strategy that blows up as soon as 
> there are more than two tokens in the macro.
>
> I tested with a bunch of system headers and results seemed 
> significantly better than before.
>
> Webrev:
>
> http://cr.openjdk.java.net/~mcimadamore/panama/macro_parser/
>
> Maurizio
>
>
>