RE: PKG_CHECK_MODULES on system without pkg-config installed?

[Jef Driesen]

address@hidden wrote:
> Jef Driesen  writes:
>> Isn't it easier to just check for the presence of the header file and/or
>> the library file, avoiding pkg-config entirely?
>
> Well, I'd prefer not to guess when possible, and not using pkg-config
> for a package that wants you to use it means you end up guessing at the
> proper locations/settings. Maybe this often works, but why risk it when
> it's not necessary?

I'm aware of the advantage of using pkg-config. I even supply the *.pc files 
for my own projects. But the point is that if I want to support systems that 
don't have pkg-config installed (like Mac OS X in my case), I have to provide a 
fallback with manual detection anyway. So why not skip pkg-config entirely? 
Most libraries have only very standard stuff in there pkg-config file, like 
this:

Libs: -L${libdir} -lusb-1.0
 Cflags: -I${includedir}/libusb-1.0

And I could simply replace the pkg-config based check with something like:
AC_CHECK_HEADER([libusb-1.0/libusb.h],
   AC_CHECK_LIB([usb-1.0], [libusb_init],
      [have_libusb=yes],
      [have_libusb=no]),
   [have_libusb=no])

if test "$have_libusb" = "yes"; then
   AC_DEFINE([HAVE_LIBUSB], [1], [Define if you have the libusb library and 
header])
   AC_SUBST([LIBUSB_CFLAGS], [])
   AC_SUBST([LIBUSB_LIBS], [-lusb-1.0])
fi

Jef