This is mostly stolen from Gecko. As there, we define the unforgeable members
on an object stored in the slots of the prototype object. They are then copied
onto instance objects when they are instantiated. It should be noted that
proxy objects see their unforgeable memebers defined on their expando object.
Unforgeable attributes aren't properly inherited in codegen (in a similar
fashion as getters and setters as filed in #5875) and require to be redefined
in derived interfaces. Fortunately, there are currently no such interfaces.
No unforgeable members can be included into the TestBinding interfaces for good
measure because they are not compatible with setters.
Given the unforgeable holder object has the same prototype as actual instances
of the interface, the finalize hook needs to check its slot pointer for nullity
before dropping it.
The new failing test isn't related to Unforgeable attributes, but to the fact
that all Document instances currently have a Location, even if their window
isn't in a browsing context.
Interfaces with no descendant need neither a Base trait nor upcast functions,
and interfaces with no ancestors neither a Derived trait nor downcast functions.
Recently, I found myself reading through the Python codegen scripts that
live in 'components/script/dom/bindings/*' and noticed that there were
many tidy violations: unnecessary semicolons, weird spacing, unused
variables, lack of license headers, etc. Considering these files are now
living in our tree and mostly maintained directly by contributors of
Servo (as opposed to being from upstream), I feel these files should not
be excluded from our normal tidy process. This commit removes the
blacklist on these files and fixes all tidy violations.
I added these subdirectories to the blacklist because they appear to be
maintained upstream somewhere else:
* "components/script/dom/bindings/codegen/parser/*",
* "components/script/dom/bindings/codegen/ply/*",
Also, I added a '# noqa' comment which tells us to ignore the
flake8 errors for that line. I chose to ignore this (instead of fixing
it) to make the work for this commit simpler for me.
