Can a Makefile target invoke commands even if a prerequisite fails?

Question

Here's a skeleton Makefile just to make it easier to describe the problem:

all_tests : unit_tests other_tests_1 other_tests_2 ... other_tests_N

unit_tests : set1_summary.txt set2_summary.txt ... setN_summary.txt

%_summary.txt : %_details.txt
    perl createSummary.pl --in $^ -out $@

%_details.txt : test_harness
    ./test_harness --test-set $*

So I have a test runner that produces a file with detailed results, and then a filtering mechanism to create a summary file.

Now, the test runner application returns an error code if any of the items in the test set fails, which will correctly abort the "all_tests" target and never invoke the other_test targets. However, I would like to run the details -> summary transformation unconditionally, since that is relevant even for a failed test run.

I've tried some different variants but the only method I could get to work was wrapping the whole command chain into a Perl script, storing away the result of the first command and using that as return value for the whole script.

But that does not feel like a very neat solution, especially since the "actual" command set is a bit more complex than what this skeleton shows. Do you know any purely GNU Make-based method to accomplish this?

Answer 1

You could have a special rule that invokes Make recursively twice, like this:

.PHONY: test
test :
    make all_tests ; make summary

The only downside is that the exit status of the top make process will no longer indicate success/failure of tests, but you could even fix that if you wanted to by a little extra scripting using the $? shell variable.