why removing configure substitutions for myprog_DEPENDENCIES?

[Harald Dunkel <harald at CoWare dot com>]

Hi folks,

I have a question about how the *_DEPENDENCIES are computed
from *_LDADD:

If I write a Makefile.am

	bin_PROGRAMS = myprog
	MYLIB = liba.a
	myprog_LDADD = \
		$(MYLIB) \
		libb.a \
		-Lsomepath \
		-lother

then liba.a is added to myprog_DEPENDENCIES as expected.
But if I set MYLIB to the same value using a configure
substitution instead, then the dependency to liba.a is
gone.

The man page says:

"The automatically-assigned value is the contents of
`prog_LDADD', with most configure substitutions, `-l',
`-L', `-dlopen' and `-dlpreopen' options removed."

Why are the configure substitutions removed? Where
is the difference in this context between defining
a configure substitution, and running 'make MYLIB=liba.a'?


Regards

Harri