[cairo] [Fwd: Backend-specific pkg-config files (was Re: [cairo-announce] cairo snapshot 1.1.8 now available)]

[Behdad Esfahbod]

Same for this.

-------- Forwarded Message --------
From: Behdad Esfahbod <behdad at cs.toronto.edu>
To: Steven Chaplin <stevech1097 at yahoo.com.au>
Subject: Backend-specific pkg-config files (was Re: [cairo-announce]
cairo snapshot 1.1.8 now available)
Date: Sun, 18 Jun 2006 23:43:36 -0400

On Sun, 2006-06-18 at 00:43 -0400, Steven Chaplin wrote:
> How do you intend for these .pc files to be used?
> Is the intention for the presence/absence of the cairo-xlib.pc file
> (for example) to indicate that the xlib backend is enabled/disabled,

Yes, that's the main intention.

>  and the
> actual content of cairo-xlib.pc is irrelevant and duplicates the
> cairo.pc file?

Not exactly.  For example, cairo-ft.pc is written as "Require:"ing
cairo, fontconfig, and ft2.  This means, it adds CFLAGS and LIBS for
those too, which is what you need if you are going to use cairo-ft.h.


> What advantage does having multiple pkg-config files have over storing
> the
> backend information in a single cairo.pc file?
> pkg-config supports custom variables so you can add (for example)
> PDF=1
> PS=0
> to cairo.pc, and then use
> $ pkg-config --variable=PDF cairo
> 1
> $ pkg-config --variable=PS cairo
> 0
> to read the backend information.

It's far simpler to do a configure.ac check for cairo-ft that is to
check if cairo has FreeType backend and erring if not.  And there's the
reason above too.

Having separate .pc files also leaves it open to change to break
cairo.so into a base and several backend .so files, that may prove to be
a good thing in the future as more backends are added.

-- 
behdad
http://behdad.org/

"Commandment Three says Do Not Kill, Amendment Two says Blood Will Spill"
        -- Dan Bern, "New American Language"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : http://lists.freedesktop.org/archives/cairo/attachments/20060620/ddaa245d/attachment.pgp