This option is already enabled when building Lagom, so let's enable it
for the main build too. We will no longer be surprised by Lagom Clang
CI builds failing while everything compiles locally.
Furthermore, the stronger `-Wsuggest-override` warning is enabled in
this commit, which enforces the use of the `override` keyword in all
classes, not just those which already have some methods marked as
`override`. This works with both GCC and Clang.
We now detect situations like this, where variables infinitely recur,
without crashing:
```css
div {
--a: var(--b);
--b: var(--a);
background: var(--a);
}
p {
--foo: var(--foo);
background: var(--foo);
}
```
We now stop processing variables once a length of 16384 tokens is
reached. This is an arbitrary number, but should be far beyond what
anyone will reasonably use, and small enough to not crash.
If a property is custom or contains a `var()` reference, it cannot be
parsed into a proper StyleValue immediately, so we store it as an
UnresolvedStyleValue until the property is compute. Then, at compute
time, we resolve them by expanding out any `var()` references, and
parsing the result.
The implementation here is very naive, and involves copying the
UnresolvedStyleValue's tree of StyleComponentValueRules while copying
the contents of any `var()`s it finds along the way. This is quite an
expensive operation to do every time that the style is computed.
This represents a property value that hasn't been converted to a
"proper" StyleValue yet. That is, it's either a custom property's value,
or a value that includes `var()` references, (or both!) since neither of
those can be fully resolved at parse time.
Now that we can serialize CSS tokens, we can just hold a string and then
re-parse it when the Supports is evaluated. This feels a little weird,
but it only happens once so it's not going to slow it down much, and it
keep the API cleaner.
This is `<general-enclosed>` in CSS grammar. It represents a section of
a `@media` or `@supports` rule that exists in some future standard that
we don't understand yet, but don't want to make the entire rule invalid.
There's not much that it can usefully do, but we store a string
representation of its contents so that it can be serialized out.
This saves user code from having to parse the numbers, as we already did
that while Tokenizing. :^)
As a bonus, we now round extremely large integers to the closest
available value, like the spec tells us to.
The changes in commit d462a6720a meant
that `CSSLoader::load_next_import_if_needed()` was no longer being
called, so no `@import` rules were loading.
The spec does not seem to mention when that loading should take place,
but WebKit does this at parse time, as each rule is added to the style
sheet. If it works for them, it's probably not that bad. :^)
So, that's what we now do here. The `CSSImportRule` creates a fetch
request when it is constructed, so each one is responsible for its own
contents.
These aren't needed now that we render using background_layers instead.
The one casualty is the resolved style for background-repeat, but that
was incorrect anyway.
Instead of storing these as individual `background-foo` properties, we
combine them together into layers, since that is how they will be
painted. It also makes it more convenient to pass them around.
This now outputs valid CSS representing the background, instead of
confusing debug info.
We can't guarantee that all the longhands have the same number of
values, since while that's always the case when parsing, we also create
BackgroundStyleValues when producing the resolved style, which just
combines the longhands together.
Like the `background-foo` longhand properties (except
`background-color`), `background` allows multiple layers to be defined,
separated by commas. A layer does not necessarily contain something to
actually draw!
This parses as a `BackgroundStyleValue`, holding a `StyleValueList` for
each property. This is mostly to make expansion into longhands simpler -
if we had a list of `BackgroundStyleValue`s instead, one per layer, then
we would have to break it up per-property anyway when computing styles.
We now can parse lists of values for these properties:
- `background-attachment`
- `background-clip`
- `background-image`
- `background-origin`
- `background-position`
- `background-repeat`
- `background-size`
This uses two new Parser methods:
`parse_simple_comma_separated_value_list()` for the simple case when
each value is parsed from a single token; and
`parse_comma_separated_value_list()` which takes a lambda for when
parsing each value is more involved.
This also means that any unconsumed tokens at the end will make the
parsing fail as it should, where previously we just ignored them.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
