[foreign] RFR 8220141: Disable libclang host environment inference in macro reparsing

[Sundararajan Athijegannathan]

Looks good

-Sundar

On 05/03/19, 3:22 PM, Maurizio Cimadamore wrote:
> Hi,
> I got at the bottom of the issue affecting our complex macro test 
> parsing on Windows. Essentially, test runs on Windows tweak the PATH 
> variable so that it points to the right MSVC env used at build time; 
> unfortunately, in this case, libclang picks that up and uses it as 
> include paths for its work. This means that build-time dependencies 
> will effectively leak into test execution. While in general this is 
> not problematic, I think it makes little sense to search for system 
> headers in the marco reparse case, which we want to be as efficient 
> and self-contained as possible.
>
> For this reason, this patch adds the -Xnostdinc option to the reparse 
> unit, to disable the libclang automagic behavior. This effectively 
> makes the extra filtering I added yesterday not necessary, but I'm 
> keeping for extra robustness.
>
> Webrev:
>
> http://cr.openjdk.java.net/~mcimadamore/panama/8220141/
>
> P.S.
>
> I think we should probably tweak JextractToolRunner to use -nostdinc 
> too, in order to get predictable test runs on all platforms.
>
> Maurizio
>
>