Question

I placed unit tests within the same directory of source code. But how could I set the LDADD in Makefile.am for all these unit tests to use specific libraries (e.g google test)?

Answer 1

The contents of LDADD are used for all target unless this variable is overridden with target_LDADD. So if you have many unit tests, and only a few actual programs, you may use LDADD for the unit tests and override it for each program with different linking requirements.

LDADD = libtest.a   # Used by default for all targets

# Unit tests, using above LDADD
check_PROGRAMS = one two three
one_SOURCES = one.c
two_SOURCES = two.c
three_SOURCES = three.c

# Main program
bin_PROGRAMS = main
main_SOURCES = main.c
main_LDADD =        # Override the LDADD setting.

A similar example can be found in the documentation of LDADD.