[Buildroot] [PATCH v2 5/7] libpng12: new package

[Arnout Vandecappelle]

On 08/09/13 19:04, Thomas Petazzoni wrote:
> Dear Spenser Gilliland,
>
> On Thu,  5 Sep 2013 23:25:19 -0500, Spenser Gilliland wrote:
>
>> +config BR2_PACKAGE_LIBPNG12
>> +	bool "libpng"
>
> Maybe:
>
> 	bool "libpng12"
>
>> +	select BR2_PACKAGE_ZLIB
>> +	help
>> +	  Library for handling PNG (Portable Network Graphics)
>> +	  images. This installs the 1.2.x series.  Different versions of
>> +	  libpng have different APIs.
>> +
>> +	  http://www.libpng.org/
>> diff --git a/package/libpng12/libpng12.mk b/package/libpng12/libpng12.mk
>> new file mode 100644
>> index 0000000..39094f2
>> --- /dev/null
>> +++ b/package/libpng12/libpng12.mk
>> @@ -0,0 +1,18 @@
>> +################################################################################
>> +#
>> +# libpng12
>> +#
>> +################################################################################
>> +
>> +LIBPNG12_VERSION = 1.2.50
>> +LIBPNG12_SERIES = 12

  Since the 12 is hardcoded in the package name, it is pretty silly to 
have this as a variable. It's there for consistency with libpng itself, 
but I don't think that that is required.

>> +LIBPNG12_SOURCE = libpng-$(LIBPNG12_VERSION).tar.bz2
>> +LIBPNG12_SITE = http://downloads.sourceforge.net/project/libpng/libpng$(LIBPNG12_SERIES)/$(LIBPNG12_VERSION)
>> +LIBPNG12_LICENSE = libpng license
>> +LIBPNG12_LICENSE_FILES = LICENSE
>> +LIBPNG12_INSTALL_STAGING = YES
>> +LIBPNG12_DEPENDENCIES = host-pkgconf zlib
>> +LIBPNG12_CONFIG_SCRIPTS = libpng$(LIBPNG12_SERIES)-config libpng-config
>
> This last one annoys me a bit: if both libpng and libpng12 install
> libpng-config, it means that another package that runs libpng-config to
> find out where libpng is and how to link against it will either be
> linked against the modern libpng or the older libpng12 depending on
> which one was installed.
>
> Since libpng12 is only installed for compatibility reasons with some
> packages, I would therefore suggest that we do not install
> libpng-config in libpng12.mk (and ensure that nothing installed by
> libpng12 can conflict with the real libpng installation).

  Sounds correct to me. It is making things more complex, of course, 
because you need something like:

LIBPNG_DEPENDENCIES += $(if $(BR2_PACKAGE_LIBPNG12),libpng12)

in libpng.mk.

  Or else you have to override the install commands, or patch the Makefile.


  Regards,
  Arnout


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
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