On 05/20/2017 09:34 AM, William F Pokorny wrote:
> On 05/20/2017 03:42 AM, clipka wrote:
>> Am 19.05.2017 um 21:35 schrieb William F Pokorny:
>>> Got back to this a while ago. The more I dig the more I think if the
>>> pkg-config command and its infrastructure exists, it should be used
>>> In fact for best reliability, the pkg-config mechanism should perhaps be
>>> used first for all our packages when available. The necessary .pc files
>>> exists for the Simple DirectMedia Layer library too it turns out.
>> Are you sure about this?
>> To my knowledge, the pkg-config mechanism tells you what packages are
>> installed via a Linux distribution's package management, such as apt.
>> However, if the user chooses to install a different version of a library
>> locally, using environment variables or parameters to `./configure` to
>> point the compiler there, then my guess is that relying on pkg-config
>> would seriously screw up things.
>> Unless pkg-config reliably addresses that issue, in my opinion our first
>> attempt should be to try and pry the relevant information from the very
>> files that will be accessed during compilation, i.e. the header files.
> I'm unsure at the moment how the other version mechanism works but would
> be a little surprised if pkg-config doesn't have a mechanism to handle
> it. I'll do a little more digging on this and see what I can turn up.
> We can certainly hard code flags to what works now if you want to do this.
> Bill P.
It looks like where multiple libraries can exist in system space the
library names must be unique and the *.pc prefixes must be unique and
where you want other than the system default you must refer to the
version by name when using pkg-config to get the compiler and linker
flags to use.
When the libraries are installed in non-standard locations - say a user
space often it seems the already mentioned PKG_CONFIG_PATH environment
variable is used to put the users versions ahead of the any system ones.
I suppose in our current set users would need to know to do this.
It looks like it is expected folks use the environment variable
PKG_CONFIG_LIBDIR to be when no system package *.pc information is to be
used. Something you might do if say compiling on Ubuntu for another
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