any way to set AM_CPPFLAGS for all subdirs at one time?

[Ed Hartnett]

Howdy all!

In my build, I allow the user to specify a location for a library, in
case they have built the library but not installed it in /usr/lib, or
some other place the loader checks automatically. The library is
called HDF5, and the configure script allows them to do something
like:

./configure --with-hdf5=/some/dir

Then in each of my subdirs, I have the following in my Makefile.am
files: 

# If the user specified a root for HDF5, use it.
if USE_HDF5_DIR
AM_CPPFLAGS += address@hidden@/include
AM_LDFLAGS = address@hidden@/lib
endif

Is there a way to do this in one place for all subdirs? Or must this
be done in each directory's Makefile.am?

Is there some more automakeish way to handle this situation?

Thanks and Happy Thanksgiving to all U.S.A. readers!

Ed

-- 
Ed Hartnett  -- address@hidden