error: too many constants jextract Windows.h

[Maurizio Cimadamore]

Hi Michael,
I've just pushed a fix for this - with that fix I've been able to 
extract the whole windows.h w/o any filters. Things are very close to 
the limit though, as the javac internal compilation goes close to using 
1.7G of memory (which is close to the max heap size).

Please let us know if that works for you.

Cheers
Maurizio

On 25/09/2020 20:25, Michael Ennen wrote:
> Okay. Understood.
>
> For now I will just manually copy in what is needed for my experiments.
>
> Windows.h is kind of a mess in terms of one not being able to include 
> only parts of it, but just a huge monolith.
>
> On Fri, Sep 25, 2020 at 3:21 AM Jorn Vernee <jorn.vernee at oracle.com 
> <mailto:jorn.vernee at oracle.com>> wrote:
>
>     Hi,
>
>     Windows.h as a whole is too big, so you need to use the --filter
>     option
>     to filter out the headers you need. For some headers I've found
>     that the
>     documentation wants you to include Windows.h, otherwise the
>     parsing will
>     not work, and this is the case with jextract as well. But, it should
>     also mention which header contains the actual declaration, so you can
>     use that one for the filter. (e.g. --filter "header.h").
>
>     Figuring out a way to extract Windows.h without needing a filter is
>     still an open problem.
>
>     HTH,
>     Jorn
>
>     On 24/09/2020 20:35, Maurizio Cimadamore wrote:
>     > I see that... there are really a tons of functions/constants
>     dropped
>     > in windows_h.
>     >
>     > I recall Jorn having done this at some point, maybe he can provide
>     > some guidance of what set of filters to add to the command line
>     to end
>     > up with a reasonable subset?
>     >
>     > Maurizio
>     >
>     > On 24/09/2020 19:04, Maurizio Cimadamore wrote:
>     >> We already have logic in place to split the underlying constants
>     >> (e.g. method handles/var handles/layouts) - but this is for the
>     >> various constant files (here it seems like the error is coming
>     from
>     >> the main windows_h file).
>     >>
>     >> I'll try to see if I can reproduce - it's mildly surprising to see
>     >> _that many_ constants ending up in the constant pool here.
>     >>
>     >> Maurizio
>     >>
>     >> On 24/09/2020 05:44, Michael Ennen wrote:
>     >>> Now that the character escaping has been fixed I can get a
>     little bit
>     >>> further trying to compile
>     >>> the jextract result of Windows.h.
>     >>>
>     >>> This time, however, I am running into a Java language limitation:
>     >>>
>     >>> src\main\java\com\dx12\Windows_h.java:10: error: too many
>     constants
>     >>>
>     >>> I am not sure if there is a nice way around this...I remember
>     >>> reading that
>     >>> the Android library did something to overcome this
>     "limitation" but
>     >>> that
>     >>> was years ago.
>     >>>
>
>
>
> -- 
> Michael Ennen