Dynamic source file list creation using GNU make

[divsorbit]

I am trying to create a rule which similar to this using GNU make:

TESTS = \
         test1\
         test2\

$(TESTS): %: %.log

%.log: tb
       runsim

Now, my question is can I automatically create the TESTS source list
dynamically without having to list every single test file in the
Makefile? For example using a ls command or something? That way the
test writer can create a test and put it in the test directory and just
run the make <testname> command to run the test without having to
modify and add the testname in the Makefile.
Thanks,
Div