The operator INIT, just like RETURN and FARG, initializes an object with
an expression. The target object of such an initialization may be a
struct with constant members.
The operator ASSIGN, on the other hand, is entirely different. It
overwrites the existing value of the object, and this is not allowed for
structs that have a constant member. Therefore it was wrong to use the
operator ASSIGN for initialization.
Having a test for each message ensures that upcoming refactorings don't
break the basic functionality. Adding the tests will also discover
previously unknown bugs in lint.
The tests ensure that every lint message can actually be triggered, and
they demonstrate how to do so. Having a separate file for each test
leaves enough space for documenting historical anecdotes, rationale or
edge cases, keeping them away from the source code.
The interesting details of this commit are in Makefile and
t_integration.sh. All other files are just auto-generated.
When running the tests as part of ATF, they are packed together as a
single test case. Conceptually, it would have been better to have each
test as a separate test case, but ATF quickly becomes very slow as soon
as a test program defines too many test cases, and 50 is already too
many. The time complexity is O(n^2), not O(n) as one would expect.
It's the same problem as in tests/usr.bin/make, which has over 300 test
cases as well.
rillig