[OpenJDK 2D-Dev] Question about splashscreen lib

[Adam Farley8]

Hi Phil,

As long as anyone using png.h also includes pngpriv, it's not a problem.

If you don't include pngpriv, the pre-process output resolves the extern 
lines to be extern 
PNG_DLL_EXPORT [function] because it appears to use the string literally 
if the macro hasn't been defined.

Right now this isn't a bug, just a quirk I was mentioning.

Best Regards

Adam Farley 


Phil Race <philip.race at oracle.com> wrote on 30/05/2018 18:07:39:

> From: Phil Race <philip.race at oracle.com>
> To: Adam Farley8 <adam.farley at uk.ibm.com>
> Cc: 2d-dev <2d-dev at openjdk.java.net>
> Date: 30/05/2018 18:08
> Subject: Re: [OpenJDK 2D-Dev] Question about splashscreen lib
> 
> I think PNG_DLL_EXPORT is not intended to be used directly.
> I am not sure what problem this causes but it is just the way this 
> library is written ...
> 
> -phil.

> On 05/30/2018 04:16 AM, Adam Farley8 wrote:
> Thanks Philip. 
> 
> The whole thing with PNG_DLL_EXPORT not being defined in png.h or 
> png.c is still confusing to me 
> (pngpriv defines it), especially since png.h ends up using it post-
> pre-processing, but I don't know if 
> that would bother people outside the minority that inspect the pre-
> processed code. 
> 
> I'll leave this here as a thought for any committer bothered by 
> this, though I won't be pushing it. 
> 
> ---- png.h ---- 
> + #ifndef PNG_DLL_EXPORT 
> + #define PNG_DLL_EXPORT 
> + #endif
> 
> Best Regards
> 
> Adam Farley 
> 
> 
> Philip Race <philip.race at oracle.com> wrote on 29/05/2018 14:23:21:
> 
> > From: Philip Race <philip.race at oracle.com> 
> > To: Adam Farley8 <adam.farley at uk.ibm.com> 
> > Cc: 2d-dev <2d-dev at openjdk.java.net> 
> > Date: 29/05/2018 14:23 
> > Subject: Re: [OpenJDK 2D-Dev] Question about splashscreen lib 
> > 
> > So far as I can see it does, just indirectly.
> > png.c includes pngpriv.h which includes png.h
> > 
> > Not including the declarations of the exported API in the file that
> > defines them would be a problem waiting to happen.
> > 
> > -phil.
> > 
> > On 5/29/18, 3:54 AM, Adam Farley8 wrote: 
> > Hi All, 
> > 
> > Does anyone know why png.c does not include png.h? 
> > 
> > This tripped me up recently, and I don't understand why png.c would 
> > not include png.h.
> > 
> > Best Regards
> > 
> > Adam Farley 
> > 
> > Unless stated otherwise above:
> > IBM United Kingdom Limited - Registered in England and Wales with 
> > number 741598. 
> > Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 
3AU
> Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with 
> number 741598. 
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 
3AU
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
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