referencing top_srcdir/top_builddir in an autoconf test?

[Monty Taylor]

Hey all,

I've got an autoconf test which includes a header file from the source
tree are configuring. This sort of break VPATH builds, since this:

configure:17782: gcc -std=gnu99 -o conftest    conftest.c -lm  >&5
conftest.c:29:58: error: libmemcached/memcached/protocol_binary.h: No
such file or directory

Obviously would need a -I${top_srcdir}. I'm fine with hacking that in to
the test - except there doesn't seem to be an available autoconf
variable I can use to fill in the value of top_srcdir in that context.

Is there a way to deal with this in general that I'm missing?

Monty