[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: #define SOMETHING some_value
From: |
Matt Wette |
Subject: |
Re: #define SOMETHING some_value |
Date: |
Thu, 15 Jun 2017 12:21:57 -0700 |
> On Jun 11, 2017, at 12:42 PM, Mark H Weaver <address@hidden> wrote:
>
> Amirouche Boubekki <address@hidden> writes:
>
>> What I do is that I hardcode the define in scheme using simple define form
>>
>> for instance, the following:
>>
>> #define SOMETHING some_value
>>
>> Becomes:
>>
>> (define SOMETHING some_value)
>
> Right. Unfortunately, preprocessor macros are replaced with their
> right-hand-sides in the first phase of C compilation (preprocessing),
> and then forgotten. These macros are not stored in the shared objects,
> so it's simply not possible for us to retrieve them.
>
> For this reason, I'm sorry to say that the association between SOMETHING
> and some_value must be redundantly represented in your Guile bindings,
> as Amirouche describes above.
>
> It would be nice to have a tool to extract this information from .h
> files automatically, but since there's no guarantee that the .h files
> are present on the user's machine at run time, nor is there a robust way
> to find those .h files, this would be a tool for your convenience as a
> developer, and would still require you to redundantly store the output
> of this tool in your Scheme sources.
>
> I'm sorry that I don't have a better answer for you.
>
> Mark
>
I now have my ffi-helper automatically extracting #defines which are constants.
I process on cairo-svg.h + cairo.h and get the following. I don’t think
defining
and exporting all these as (define CAIRO_VERSION_MAJOR 1) etc is a good idea.
Comments on this method of providing access?
Matt
(define xxx-def-val
(let ((deftab
'((CAIRO_VERSION_MAJOR . 1)
(CAIRO_VERSION_MINOR . 14)
(CAIRO_VERSION_MICRO . 8)
(CAIRO_HAS_FC_FONT . 1)
(CAIRO_HAS_FT_FONT . 1)
(CAIRO_HAS_GOBJECT_FUNCTIONS . 1)
(CAIRO_HAS_IMAGE_SURFACE . 1)
(CAIRO_HAS_MIME_SURFACE . 1)
(CAIRO_HAS_OBSERVER_SURFACE . 1)
(CAIRO_HAS_PDF_SURFACE . 1)
(CAIRO_HAS_PNG_FUNCTIONS . 1)
(CAIRO_HAS_PS_SURFACE . 1)
(CAIRO_HAS_QUARTZ_FONT . 1)
(CAIRO_HAS_QUARTZ_IMAGE_SURFACE . 1)
(CAIRO_HAS_QUARTZ_SURFACE . 1)
(CAIRO_HAS_RECORDING_SURFACE . 1)
(CAIRO_HAS_SCRIPT_SURFACE . 1)
(CAIRO_HAS_SVG_SURFACE . 1)
(CAIRO_HAS_TEE_SURFACE . 1)
(CAIRO_HAS_USER_FONT . 1)
(CAIRO_HAS_XCB_SURFACE . 1)
(CAIRO_HAS_XLIB_SURFACE . 1)
(CAIRO_HAS_XLIB_XCB_FUNCTIONS . 1)
(CAIRO_HAS_XLIB_XRENDER_SURFACE . 1)
(CAIRO_HAS_XML_SURFACE . 1)
)))
(lambda (k) (assq-ref deftab k))))