Logging internals

To use the libtio logging interface, just include internals.h at source root, or include something that ends up including it, directly or indirectly. If the interface looks weird to you, that may be because this has been an experiment to make a logging system compatible with K&R and ANSI C (which explains the double parenthesis).

There are two different types of logging in libtio: message logging, and memory logging (which end up being the same to the user).

First, message logging. The main macro for this is msg((LEVEL, FORMAT, ...)). The level is of the form ll_<level>, so ll_info, ll_warn, ll_error or ll_fatal. The format and arguments are for the printf-like function behind, so you can use msg((ll_info, "%d + %s", 5, "coucou")) for example.

If you are doing a condition only for a logging instruction, with no else if or else clause in the same state behind, you can use the ifmsg, elifmsg and elsemsg macros. ifmsg and elifmsg take the condition and the arguments for the msg function. For example:

if (something.cool > 0) {
        /* do something because it is cool */
}
elifmsg(something.cool == 0, (ll_warn, "The thing is not cool."))
elsemsg((ll_error, "The thing has NEGATIVE coolness, that's not cool."))

The memory logging family are organized the same, except the names are mem, ifmem, elifmem and elsemem, and instead of the format and format arguments, you have the pointer and the memory area size, e.g.:

char cooldude = "COOLDUD\x7F";
msg((ll_info, "Cool dude magic:"));
mem((ll_info, cooldude, 8));