Move MAX, MIN and ABS to contiki-macros

[cmorty]

Based on the discussion in #878 I started moving MIN, MAX and ABS macros to an extra file.

[adamdunkels]

This is a good move, but please prefix the names with contiki_macros_, i.e. CONTIKI_MACROS_MAX().

But I'd suggest using a shorter name than contiki-macros.h.

[cmorty]

Is it a good Idea to make these commonly used macros unnecessarily long? Especially as I can see no good reason to prefix them. The definitions are kind of a standard.
As for the filename, I don't really care. As there already is contiki-lib.h and contiki-net.h, etc

[adamdunkels]

Lets put them in contiki.h and call them CONTIKI_MAX() and similar.

[cmorty]

...I still don't see any advantage of using CONTIKI_MAX instead of just 'MAX'. (I can only repeat my arguments against it.)
As for the filename: There are quite some files that don't include "contiki.h", but use MIN/MAX. So maybe contiki-compiler.h is better, as these macros basically use the CPP to overcome shortcomings of the C-Language.

[adamdunkels]

Good point, lets use the existing cc.h for this! https://github.com/contiki-os/contiki/blob/master/core/sys/cc.h

[cmorty]

Ok, that seems reasonable. Will do.

[cmorty]

Ok, fixed. While at it, I noticed a very inconsistent used of "" and <> when including files. This may lead to some very ugly side-effect. IMO we should used <> for all files from the contiki-tree and "" only for the files in the same folder. On the other side, using "" for everything would allow easy overrides of header files. (All in all I assume that very few codes actually know the difference. ;) )

[adamdunkels]

The Contiki code uses "" for all Contiki headers and <> only for C library and underlying OS headers.

So it should be #include "sys/cc.h" and not #include <sys/cc.h>

[nvt]

This is a welcome addition of macros, but the suggested macro that initiated this discussion is not included here: IS_POWER_OF_TWO. Perhaps we want this too, but I'm happy with the change as it is also. When this collection of macros may grow a bit later, however, it may be necessary to put it into another file than sys/cc.h, since that file seems to be more for handling different C compiler quirks.

[cmorty]

@nvt My original idea was to introduce a new contiki-macros-h and then add IS_POWER_OF_TWO. But the is latter is not as easy to grep. ;) - But if I find some time I'll do that, too.

[nvt]

👍

[g-oikonomou]

Where are we on this one? I mean it would naturally need rebased, but it'd be great to get an update (?)

[bthebaudeau]

It would be great to merge this one now (after rebasing if needed), and to create a new PR later for #878.

[cmorty]

Getting this merged rather soon would be nice. Had to fix two new files.

[bthebaudeau]

Sorry, rebase needed.

[cmorty]

There you go. Rebase seems fine. :)

[bthebaudeau]

According to what @adamdunkels said, double quotes should be used here, not angle brackets.

[cmorty]

That one slipped through. I'll look into it

[bthebaudeau]

@adamdunkels: In the end, are you happy with the naming? You did not say if you finally agreed with @cmorty arguments. I vote for simplicity here: a prefix would bring no benefits.

[bthebaudeau]

👍 from me.

[simonduq]

and another 👍

[adamdunkels]

👍