Add a forever unstable opt-out of const qualification checks
r? @eddyb
cc @RalfJung @Centril
basically a forever unstable way to screw with const things in horribly unsafe, unsound and incoherent ways.
Note that this does *not* affect miri except by maybe violating assumptions that miri makes. But there's no change in how miri evaluates things.
Overhaul `syntax::fold::Folder`.
This PR changes `syntax::fold::Folder` from a functional style
(where most methods take a `T` and produce a new `T`) to a more
imperative style (where most methods take and modify a `&mut T`), and
renames it `syntax::mut_visit::MutVisitor`.
This makes the code faster and more concise.
rustdoc: don't try to get a DefId for a Def that doesn't have one
Fixes https://github.com/rust-lang/rust/issues/58054
The compiler allows you to write a `use` statement for a built-in non-macro attribute, since `use proc_macro` can apply to both the `proc_macro` crate and the `#[proc_macro]` attribute. However, if you write a use statement for something that *doesn't* have this crossover, rustdoc will try to use it the same way as anything else... which resulted in an ICE because it tried to pull a DefId for something that didn't have one. This PR makes rustdoc skip those lookups when it encounters them, allowing it to properly process and render these imports.
Currently it just unconditionally allocates it in the arena.
For a "Clean Check" build of the the `packed-simd` benchmark, this
change reduces both the `max-rss` and `faults` counts by 59%; it
slightly (~3%) increases the instruction counts but the `wall-time` is
unchanged.
For the same builds of a few other benchmarks, `max-rss` and `faults`
drop by 1--5%, but instruction counts and `wall-time` changes are in the
noise.
Fixes#57432, fixes#57829.
Update cargo
7 commits in 245818076052dd7178f5bb7585f5aec5b6c1e03e..4e74e2fc0908524d17735c768067117d3e84ee9c
2019-01-27 15:17:26 +0000 to 2019-02-02 17:48:44 +0000
- Fix overlapping progress with stdout. (rust-lang/cargo#6618)
- Improve progress bar flickering. (rust-lang/cargo#6615)
- Add detail to multiple rename deps (rust-lang/cargo#6603)
- Fix race condition in local registry crate unpacking (rust-lang/cargo#6591)
- Revert "Make incremental compilation the default for all profiles." (rust-lang/cargo#6610)
- Fixup the docs on crate-type (rust-lang/cargo#6606)
- Document that owner --add now just invites (rust-lang/cargo#6604)
This commit changes `syntax::fold::Folder` from a functional style
(where most methods take a `T` and produce a new `T`) to a more
imperative style (where most methods take and modify a `&mut T`), and
renames it `syntax::mut_visit::MutVisitor`.
The first benefit is speed. The functional style does not require any
reallocations, due to the use of `P::map` and
`MoveMap::move_{,flat_}map`. However, every field in the AST must be
overwritten; even those fields that are unchanged are overwritten with
the same value. This causes a lot of unnecessary memory writes. The
imperative style reduces instruction counts by 1--3% across a wide range
of workloads, particularly incremental workloads.
The second benefit is conciseness; the imperative style is usually more
concise. E.g. compare the old functional style:
```
fn fold_abc(&mut self, abc: ABC) {
ABC {
a: fold_a(abc.a),
b: fold_b(abc.b),
c: abc.c,
}
}
```
with the imperative style:
```
fn visit_abc(&mut self, ABC { a, b, c: _ }: &mut ABC) {
visit_a(a);
visit_b(b);
}
```
(The reductions get larger in more complex examples.)
Overall, the patch removes over 200 lines of code -- even though the new
code has more comments -- and a lot of the remaining lines have fewer
characters.
Some notes:
- The old style used methods called `fold_*`. The new style mostly uses
methods called `visit_*`, but there are a few methods that map a `T`
to something other than a `T`, which are called `flat_map_*` (`T` maps
to multiple `T`s) or `filter_map_*` (`T` maps to 0 or 1 `T`s).
- `move_map.rs`/`MoveMap`/`move_map`/`move_flat_map` are renamed
`map_in_place.rs`/`MapInPlace`/`map_in_place`/`flat_map_in_place` to
reflect their slightly changed signatures.
- Although this commit renames the `fold` module as `mut_visit`, it
keeps it in the `fold.rs` file, so as not to confuse git. The next
commit will rename the file.
The layout of a extern_type static is unsized, but may pass the
Well-Formed check in typeck. As a result, we cannot assume that
a static is sized when generating the `Place` for an r-value.
Don't try to clean predicates involving ReErased
There's nothing to render when we have a bound involving ReErased (either
a type or region outliving it), so we don't attempt to generate a clean
WherePredicate
Fixes#57806
I haven't been able to come up with a minimized reproduction for the issue, but I've confirmed that this allows the docs to build for `parqet-rs`
update split docs
Some confusion about split popped up at https://news.ycombinator.com/item?id=19080931 since the docs sorta sound like `&str`, `char` and closures are the only types that can be patterns.
cc @steveklabnik
Remove stray FIXME
These were copied from the WebAssembly implementation, and later commented. There is nothing to be fixed, RWLock is Send/Sync because all member fields are Send/Sync.
r? @joshtriplett
Remove weasel word in docs for iter's take_while()
The phrase "... or some similar thing." is very vague and contributes nothing to understanding the example. Simply removed.
hir: add more HirId methods
Adds a few more methods operating on `HirId` instead of `NodeId` with the intention of replacing the old ones in the near future.
r? @Zoxc
