Support pair and value iterable WebIDL bindings
The actual iterator implementation and JSAPI calls related to setting up the interface are ported directly from Gecko's Codegen.py, IterableIterator.h, and IterableIterator.webidl. The changes to support multiple interfaces in one file are required because the internal iterator interface the parser generates gets associated with the original interface's WebIDL file. It seemed like a good time to address #571 in that case.
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#12628 and fix#571.
- [X] There are tests for these changes
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Each interface gets its own module named ${Interface}Binding. Structs, enums, and callbacks
continue to use the root module of the binding file. If there is only one interface in the
file, we generate reexports for several public APIs and types so that existing DOM implementations
don't need any modifications. When multiple interfaces exist, the reexported names get the interface
name prepended (eg. FooWrap instead of Wrap).
As part of this work, stop glob-importing all DOM types in every generated binding and start generating
more targeted lists of relevant types based on the methods, members, etc. of WebIDL types that are in use.
This currently breaks Servo on Android, because there are a number of
interdependent changes that cannot easily land serially in a way that
keeps it working throughout. We expect to fix this in the near future.
Support sequences of sequences in generated bindings.
This fixes a blocker for #11897. `unroll` recursively gets the inner type of any sequence type encountered, so it's inappropriate for codegen that only wants the immediate inner type. However, if a type identifies as a sequence and is nullable, we need to reach through the nullable wrapper first. Gecko does very similar things.
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#12528 (github issue number if applicable).
- [X] There are tests for these changes
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unroll recursively gets the inner type of any sequence type encountered, so it's inappropriate for codegen that only wants the immediate inner type. However, if a type identifies as a sequence and is nullable, we need to reach through the nullable wrapper first. Gecko does very similar things.
Replace return_address usage for rooting with stack guards and convenience macros.
The existing `Rooted` and `RootedVec` users were migrated the the following two macros:
```rust
let x = Rooted::new(cx, value);
// Was changed to:
rooted!(in(cx) let x = value);
// Which expands to:
let mut __root = Rooted::new_unrooted(value);
let x = RootedGuard::new(cx, &mut __root);
```
```rust
let mut v = RootedVec::new();
v.extend(iterator);
// Was changed to:
rooted_vec!(let v <- iterator);
// Which expands to:
let mut __root = RootableVec::new();
let v = RootedVec::new(&mut __root, iterator);
```
The `rooted!` macro depends on servo/rust-mozjs#272.
These APIs based on two types, a container to be rooted and a rooting guard, allow implementing both `Rooted`-style rooting and `Traceable`-based rooting in stable Rust, without abusing `return_address`.
Such macros may have been tried before, but in 1.9 their hygiene is broken, they work only since 1.10.
Sadly, `Rooted` is a FFI type and completely exposed, so I cannot prevent anyone from creating their own, although all fields but the value get overwritten by `RootedGuard::new` anyway.
`RootableVec` OTOH is *guaranteed* to be empty when not rooted, which makes it harmless AFAICT.
By fixing rust-lang/rust#34227, this PR enables Servo to build with `-Zorbit`.
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fixrust-lang/rust#34227
- [x] These changes do not require tests because they are not functional changes
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