I am using a yacc/bison source file in a libtool library, but I create both an installable static/shared version of the library as well as an internal convenience library (so I can later on link the PIC objects directly into another shared library). Since I need the header file with the parser definitions I use the "AM_YFLAGS = -d" option to have automake do this for me.
The problem is that automake (1.7.7) doesn't see that the .y source files in the _SOURCES definitions of two libraries (the installable one and the internal convenience one) are actually the same and thus, because of the AM_YFLAGS definition, creates two identical rules in the final Makefile for the .h file. This is something the make program obviously doesn't like and I therefore receive a 'warning: overriding commands for target' warning.
A simple Makefile.am example that shows this behavior is: --- AM_YFLAGS = -d
lib_LTLIBRARIES = libfoo.la noinst_LTLIBRARIES = libfoo_internal.la
BUILT_SOURCES = foo.h
libfoo_la_SOURCES = foo.y libfoo_la_LDFLAGS = -version-info 0:0:0
libfoo_internal_la_SOURCES = foo.y ---
Does anybody know how I can get rid of the make warnings (and, just out of interest, will these warnings stay warnings when I use a different make program instead of GNU make, or might other make programs see the double .h rule definition as an error)?
P.S. I also have, for anyone who is interested, a small example package available with just a single .y file that reproduces the problem.
Regards, Sander Niemeijer
