protocol: Use signed int for scale values

We usually use signed ints for things like this, to avoid
issues C sign coersion.
protocol: Modes are specified in HW pixels

Modes are mainly meant to be used in coordination with fullscreen in
DRIVER mode, by e.g. games. For such games what they generally want
is to match some hardware mode and resize their window for that. We
don't really need to complicate this with the scaling. So, we
keep the resolutions in HW pixels, and drop the SCALED flag (as it
is now useless).

This lets you just create e.g an 800x600 buffer of scale 1 and
fullscreen that, ignoring the output scaling factor (although you can
of course also respect it and create a 400x300 surface at scale 2).
Conceptually the mode change is treated like a scaling which overrides
the normal output scale.

The only complexity is the FILL mode where it can happen that the user
specifies a buffer of the same size as the screen, but the output has scale
2 and the buffer scale 1. Just scanning out this buffer will work, but
effectively this is a downscaling operation, as the "real" size of the surface
in pels is twice the size of the output. We solve this by allowing FILL to
downscale (but still not upscale).
build: Add declaration checks to check for required syscall flags

The required flags are relatively new and some older enterprise distributions
do not feature them.

https://bugs.freedesktop.org/show_bug.cgi?id=63360
protocol: Add a name event to give seat name

This provides the ability for a client to differentiate events from
different seats in a multiple seat environment.
Add a "side" field and some sanity checks to wl_map.

The original wl_map implementation did no checking to ensures that ids fell
on the correct side of the WL_SERVER_ID_START line.  This meant that a
client could send the server a server ID and it would happily try to use
it.  Also, there was no distinction between server-side and client-side in
wl_map_remove.  Because wl_map_remove added the entry to the free list
regardless of which side it came from, the following set of actions would
break the map:

1. Client creates a bunch of objects
2. Client deletes one or more of those objects
3. Client does something that causes the server to create an object

Because of the problem in wl_map_remove, the server would take an old
client-side id, apply the WL_SERVER_ID_START offset, and try to use it as a
server-side id regardless of whether or not it was valid.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Add support for flags in the wl_map API and add a WL_MAP_ENTRY_LEGACY flag

The implementation in this commit allows for one bit worth of flags.  If
more flags are desired at a future date, then the wl_map implementation
will have to change but the wl_map API will not.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Add accessor functions for wl_resource and deprecate wl_client_add_resource

This is the first step towards making wl_resource an opaque pointer type.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
protocol: Move new name event below existing requests and events and version it

Missed v2 of Robs patch that already did this based on feedback from
Ander and Daniel.
Change WL_ZOMBIE_OBJECT from 0x2 to an actual pointer

In order to use the second-lowest bit of each pointer in wl_map for the
WL_MAP_ENTRY_LEGACY flag, every pointer has to be a multiple of 4.  This
was a good assumption, except with WL_ZOMBIE_OBJECT.  This commit creates
an actual static variable to which WL_ZOMBIE_OBJECT now points.  Since
things are only every compared to WL_ZOMBIE_OBJECT with "==" or "!=", the
only thing that matters is that it is unique.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Remove incorrect sanity-check from wl_map_insert_at

I got a little over-eager with my sanity checks and didn't realize that the
client uses wl_map_insert_at to mark objects as zombies when they come from
the server-side.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Update tests for wl_map changes and add a map_flags test
server: Add wl_resource_get_id()