About Caddeus

Caddeus is a prepared GNUmakefile oriented to the strict quality of C programs.

It features an optimal test runner, strict C flags by default, automatic Cppcheck, Clang static analyzer and Valgrind usage if installed on the system.

Check out doc/how-to-use.txt file for a tutorial.

Rationale

I found out that I'm not a good enough C programmer:

• Cppcheck and the Clang static analyzer constantly reveals mistakes and omissions in my code.

• I found out that running Valgrind on my legacy code revealed many memory leaks.

• Furthermore, I could only run Valgrind on specific code flows. I needed to find a way to systematically test multiple code flows.

• This meant that I had to redisign part of my code just to make it systematically analyzable.

So I attempted the testing paradigm under C. This helped because I could run Valgrind on my tests to systematically check different code flows, but:

• I had to redesign most of my C code.

• At first I had to manually run the tests each time I changed a file, so I automated it. Then I found out that I was running the full Valgrindly slow test suite each time even after a change on a single file.

• I started defining dependencies on tests to my GNUmakefile to prevent testing redundancy but this was quite time consuming even for small projects.

So I needed a tool automate all this in a simpler way. This is how the Caddeus GNUmakefile was born. It's nothing more than the consolidation of multiple well-known techniques into a single GNUmakefile.

This repository hosts the Caddeus GNUmakefile, but also is a sample "Hello world" C project that uses it.

Features and characteristics

• Multiple tests per unit. For a unitname.o target, tests named tests/unitname/testname.t.c can exist. A unitname/testname.t binary will be automatically compiled and run.

• Prevent useless tests from running if none of its dependencies has been touched. This works by creating a timestamp file when a tests succeed and using it along with GNU Make.

• Allow usage of scripted tests under the .tt extension.

• Application tests can be run after full build.

• CFLAGS are tight. Compiler errors usually indicate programming mistakes and should now let compilation be successful. They can be relaxed by the developer.

• Automatic test discovery. If a .t.c or .tt file exists under tests/ it's an application test If a .t.c or .tt file exists under tests/unitname, it's a unit test.

• Optionally disable problematic tests by renaming them to something outside of .t.c or .tt, like .t.c.disabled or .tt.disabled.

• Automatic generation of dependency information. If module.c includes module.h, touching module.h will automatically force module.o regeneration.

• Lower targets depend on GNUmakefile. This causes the whole project rebuild if GNUmakefile changes. This ensures that a change on GNUmakefile does not break project build or build partially. This is tweakable, though.

• All the magic is located in a single GNUmakefile section to help prevent accidental modification.

• Independent libraries can be individually specified for each test by using testname_LDLIBS or unitname/testname_LDLIBS variables,

• Optional timeout support to kill a test if it infinite-loops.

• Automatic Valgrind Memcheck usage, if installed.

• Automatic Cppcheck usage if installed.

• Automatic Clang static analyzer usage, if installed.