Automate the subr_unit test.

[asomers]

Summary

Build and install the subr_unit test program originally written by phk, and run
it with the other ATF test.

tests/sys/kern/Makefile
Build and install the subr_unit test as a plain test

sys/kern/subr_unit.c

• Reduce the default number of repetitions from 100 to 1, and add a

	  command-line parser to override it.

• Don't be so noisy by default
• Fix an include problem for the test build

[asomers]

tests/sys/kern/Makefile

29 ↗

(On Diff #15412)

FYI, I'll be able to remove the -Wno-sign-compare after merging D6004

[ngie]

Should a similar approach be used with to tests/sys/kern/acct/acct_test here ?

tests/sys/kern/Makefile

7 ↗

(On Diff #15412)

Please use SRCTOP instead.

28 ↗

(On Diff #15412)

This should be fixed...

[asomers]

Use SRCTOP and justify disabling compiler warnings.

[asomers]

tests/sys/kern/Makefile

28 ↗

(On Diff #15412)

This is a weird one. There are a lot of functions, such as clean_unrhdrl, whose prototypes are in headers that cannot be included in userland. In the test program, though, they're effectively static. There are three options:

1. Add prototypes in an #ifndef _KERNEL section near the top of subr_unit.c. I don't like this option because it isn't DRY.

2. Move the relevant prototypes into their own header, subr_unit.h, and include that from systm.h. I don't like this option because it seems heavy-handed and there's no precedent for it.

3. Add -Wno-missing-prototypes. If you agree that this is better than option 2, then I'll add some comments about why I did it.

[asomers]

Are you satisfied, ngie?

[ngie]

sys/kern/subr_unit.c

888 ↗

(On Diff #15506)

I've probably remove "rather than ... kern" because that can change at a later date.

943 ↗

(On Diff #15506)

I'd probably use a macro/put this up near the comment about why things are the way they are.

986–989 ↗

(On Diff #15506)

This is not properly sorted (char* -> long -> int -> u_int -> bool)

996–997 ↗

(On Diff #15506)

How do you know errno hasn't been set to a different value by another preceding call? The official way to do this (per opengroup) is to set errno = 0, then test out errno after this call: http://pubs.opengroup.org/onlinepubs/7908799/xsh/strtol.html

1019 ↗

(On Diff #15506)

a != NULL?

[asomers]

Apply ngie's comments

[ngie]

LGTM. Thanks!