rename kind="doh" to kind="doh_legacy"

See merge request !1180

The purpose of this change is to make it harder to accidentally use the
legacy DoH implementation and free up the "doh" kind which may be used
as an alias to a modern implementation in the future.

lib/utils: define kr_require(), kr_assume() macros

Closes #495

See merge request !1146

To (hopefully) improve readability, rename the typical macro usage of:

    if (!kr_assume(x)) y; // to
    if (kr_fails_assert(x)) y;

As a convenience, replace the assert without a return value to a more
simple version:

    (void)!kr_assume(x);  // becomes
    kr_assert(x);

Vladimír Čunát authored 3 years ago and Tomas Krizek committed 3 years ago

Trying to handle the NULL here was pointless, so let's simplify.
As it was, it couldn't trigger anyway (would crash earlier).

Vladimír Čunát authored 3 years ago and Tomas Krizek committed 3 years ago

It's a little more verbose, but it should be more valuable in case
we encounter them.

Vladimír Čunát authored 3 years ago and Tomas Krizek committed 3 years ago

Default 5 minutes (but off).
Randomize the delays +-25%.

- add lua options debugging.assumption_abort and
  debugging.assumption_fork to make the behaviour configurable
- select default values based on meson buildtype:
  - debug/debugoptimized (default, e.g. used in CI) - abort and don't
    fork
  - plain/release - don't abort, but fork if abort is user-configured