2014922 - Untangle pseudo-element and anon box definitions.

Status: NEW

(Core :: CSS Parsing and Computation, enhancement, P3)

Description

[Emilio Cobos Álvarez [:emilio]]

I looked at this because in bug 2014331 I need to mark more pseudos as element-backed, and it's kinda silly the state our setup is in right now.

This is all a somewhat historical mess, because in the old style system pseudo-elements were just atoms, and we had that different types of atom setup. The source of truth for these right now lives in a header macro file, which isn't very flexible.

But now we have PseudoStyleType which represents both pseudos and anon boxes. Plus, the ::-moz-tree pseudo-elements are defined as anon boxes which doesn't make any sense.

Unify this in a similar way we treat CSS properties.

Comment 1

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2014922 - Untangle pseudo-element and anon box definitions. r=#style!,#xpcom-reviewers!

I looked at this because in bug 2014331 I need to mark more pseudos as
element-backed, and it's kinda silly the state our setup is in right
now.

This is all a somewhat historical mess, because in the old style system
pseudo-elements were just atoms, and we had that different types of atom
setup. The source of truth for these right now lives in a header macro
file, which isn't very flexible.

But now we have PseudoStyleType which represents both pseudos and anon
boxes, and is similar to the rust side PseudoElement enum.

Plus, the ::-moz-tree pseudo-elements are defined as anon boxes which
doesn't make any sense, so move them to pseudo-elements while at it.

Unify this in a similar way we treat CSS properties: Source of truth is
in pseudo_elements.toml / anon_boxes.toml, and we generate Rust and C++
as needed. This allows removing the nsStaticAtom subclass thing from
XPCOM, too.

This avoids some nasty duplication around which pseudos are pref-gated
and what not as well.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/c70290c61956
https://hg.mozilla.org/integration/autoland/rev/ad7828fad99b
Untangle pseudo-element and anon box definitions. r=firefox-style-system-reviewers,xpcom-reviewers,layout-reviewers,dshin,nika

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/27f4694604d9
https://hg.mozilla.org/integration/autoland/rev/edf80f398885
Revert "Bug 2014922 - Untangle pseudo-element and anon box definitions. r=firefox-style-system-reviewers,xpcom-reviewers,layout-reviewers,dshin,nika" for causing bustage @ ElementAnimationData.h

Comment 4

[Norisz Fay [:noriszfay]]

Backed out for causing bustage @ ElementAnimationData.h

Backout link

Push with failures

Failure log

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/30b7a3d89ac9
https://hg.mozilla.org/integration/autoland/rev/efabf69e5d35
Untangle pseudo-element and anon box definitions. r=firefox-style-system-reviewers,xpcom-reviewers,layout-reviewers,dshin,nika