This reduces a lot the boilerplate that's needed in order to add simple binding
functions.
This starts using &Foo and Option<&Foo> instead, and as a result we need to
remove the servo_function_signatures test, which is a bit unfortunate.
I think it's worth though, this causes problems on some platforms (see bug
1534844), and messing up the functions signature is not something that I've ever
seen (other than bug 1308234, which already had all the FooBorrowed mess which
I'm removing).
Also, cbindgen understands references and Option<&Foo>, so it will be the way to
go in the future.
After this patch we can also remove HasSimpleFFI, but I've kept it for now since
I still use it in a few places, and this patch is quite big on its own.
Differential Revision: https://phabricator.services.mozilla.com/D24092
The only reason why we had the `existing_style_for_style_damage` bit is to apply
some optimizations that we don't have anymore.
I still want to reintroduce a few of them, at least for the non-eager
pseudo-element case... But I think I won't need this at all.
This allows us to remove a fair amount of Gecko code too.
Bindgen bitfield enums don't work as return values with the Linux 32-bit ABI at
the moment because they wrap the value in a struct.
This causes the Rust side to believe the callee expects space for the struct
return value, while C++ believes it's just an integer value.
MozReview-Commit-ID: FRBqlZuMiAR
The alias is left there temporarilly and will be removed completely in a later commit where
also components/style/gecko/generated/structs_{debug|release}.rs are re-generated (they still
use the old alias).
The primary idea of this patch is to ditch the rigid enum of Previous/Current
styles, and replace it with a series of indicators for the various types of
work that needs to be performed (expanding snapshots, rematching, recascading,
and damage processing). This loses us a little bit of sanity checking (since
the up-to-date-ness of our style is no longer baked into the type system), but
gives us a lot more flexibility that we'll need going forward (especially when
we separate matching from cascading). We also eliminate get_styling_mode in
favor of a method on the traversal.
This patch does a few other things as ridealongs:
* Temporarily eliminates the handling for transfering ownership of styles to the
frame. We'll need this again at some point, but for now it's causing too much
complexity for a half-implemented feature.
* Ditches TRestyleDamage, which is no longer necessary post-crate-merge, and is
a constant source of compilation failures from either needing to be imported
or being unnecessarily imported (which varies between gecko and servo).
* Expands Snapshots for the traversal root, which was missing before.
* Fixes up the skip_root stuff to avoid visiting the skipped root.
* Unifies parallel traversal and avoids spawning for a single work item.
* Adds an explicit pre_traverse step do any pre-processing and determine whether
we need to traverse at all.
MozReview-Commit-ID: IKhLAkAigXE
