Don't implement mem::replace with mem::swap.
`swap` is a complicated operation, so this changes the implementation of `replace` to use `read` and `write` instead.
See https://github.com/rust-lang/rust/pull/83019.
I wrote there:
> Implementing the simpler operation (replace) with the much more complicated operation (swap) doesn't make a whole lot of sense. `replace` is just read+write, and the primitive for moving out of a `&mut`. `swap` is for doing that to *two* `&mut` at the same time, which is both more niche and more complicated (as shown by `swap_nonoverlapping_bytes`).
This could be especially interesting for `Option<VeryLargeStruct>::take()`, since swapping such a large structure with `swap_nonoverlapping_bytes` is going to be much less efficient than `ptr::write()`'ing a `None`.
But also for small values where `swap` just reads/writes using temporary variable, this makes a `replace` or `take` operation simpler:
Update llvm-project submodule
Fixes#82833. Fixes#82859. Probably also `fixes` #83025. This also merges in the current upstream 12.x branch.
r? `@nagisa`
Value trees won't have scalar ptr at all, so we need a scalar int printing method anyway. This way we'll be able to share that method between all const representations.
valtree is a version of constants that is inherently safe to be used within types.
This is in contrast to ty::Const which can have different representations of the same value. These representation differences can show up in hashing or equality comparisons, breaking type equality of otherwise equal types.
valtrees do not have this problem.
expand: Do not allocate `Lrc` for `allow_internal_unstable` list unless necessary
This allocation is done for any macro defined in the current crate, or used from a different crate.
EDIT: This also removes an `Lrc` increment from each *use* of such macro, which may be more significant.
Noticed when reviewing https://github.com/rust-lang/rust/pull/82367.
This probably doesn't matter, but let's do a perf run.
Rollup of 11 pull requests
Successful merges:
- #80385 (Clarify what `Cell::replace` returns)
- #82571 (Rustdoc Json: Add tests for Reexports, and improve jsondocck)
- #82860 (Add `-Z unpretty` flag for the THIR)
- #82950 (convert slice doc link to intra-doc links)
- #82965 (Add spirv extension handling in compiletest)
- #82966 (update MSYS2 link in README)
- #82979 (Fix "run" button position in error index)
- #83001 (Ignore Vim swap files)
- #83003 (rustdoc: tweak the search index format)
- #83013 (Adjust some `#[cfg]`s to take non-Unix non-Windows operating systems into account)
- #83018 (Reintroduce accidentally deleted assertions.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Adjust some `#[cfg]`s to take non-Unix non-Windows operating systems into account
This makes compilation to such targets (e.g. `wasm32-wasi`) easier.
cc rust-lang/miri#722bb6d1d0a09 (r48100619)
rustdoc: tweak the search index format
This essentially switches search-index.js from a "array of struct" to a "struct of array" format, like this:
{
"doc": "Crate documentation",
"t": [ 1, 1, 2, 3, ... ],
"n": [ "Something", "SomethingElse", "whatever", "do_stuff", ... ],
"q": [ "a::b", "", "", "", ... ],
"d": [ "A Struct That Does Something", "Another Struct", "a function", "another function", ... ],
"i": [ 0, 0, 1, 1, ... ],
"f": [ null, null, [], [], ... ],
"p": ...,
"a": ...
}
So `{ty: 1, name: "Something", path: "a::b", desc: "A Struct That Does Something", parent_idx: 0, search_type: null}` is the first item.
This makes the uncompressed version smaller, but it really shows on the compressed version:
notriddle:rust$ wc -c new-search-index1.52.0.js
2622427 new-search-index1.52.0.js
notriddle:rust$ wc -c old-search-index1.52.0.js
2725046 old-search-index1.52.0.js
notriddle:rust$ gzip new-search-index1.52.0.js
notriddle:rust$ gzip old-search-index1.52.0.js
notriddle:rust$ wc -c new-search-index1.52.0.js.gz
239385 new-search-index1.52.0.js.gz
notriddle:rust$ wc -c old-search-index1.52.0.js.gz
296328 old-search-index1.52.0.js.gz
That's a 4% improvement on the uncompressed version (fewer `[]`, and also changing `null` to `0` in the parent_idx list), and 20% improvement after gzipping it, thanks to putting like-typed data next to each other. Any compression algorithm based on a sliding window will probably show this kind of improvement.
Ignore Vim swap files
I got this from [a Stack Overflow answer][so].
(I didn't add `*~` because it was already there.)
[so]: https://stackoverflow.com/a/4824199
Add spirv extension handling in compiletest
We're trying to use `compiletest` for Rust-GPU's testsuite, and ran into an issue with host specific extensions. This adds handling to fix that.
convert slice doc link to intra-doc links
Continuing where #80189 stopped, with `core::slice`.
I had an issue with two dead links in my doc when implementing `Deref<Target = [T]>` for one of my type. This means that [`binary_search_by_key`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.binary_search_by_key) was available, but not [`sort_by_key`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.sort_by_key) even though it was linked in it's doc (same issue with [`as_ptr`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.as_ptr) and [`as_mut_pbr`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.as_mut_ptr)). It becomes available if I implement `DerefMut`, as it needs an `&mut self`.
<details>
<summary>Code that will have dead links in its doc</summary>
```rust
pub struct A;
pub struct B;
impl std::ops::Deref for B{
type Target = [A];
fn deref(&self) -> &Self::Target {
&A
}
}
```
</details>
I removed the link to `sort_by_key` from `binary_search_by_key` doc as I didn't find a nice way to have a live link:
- `binary_search_by_key` is in `core`
- `sort_by_key` is in `alloc`
- intra-doc link `slice::sort_by_key` doesn't work, as `alloc` is not available when `core` is being build (the warning can't be ignored: ```error[E0710]: an unknown tool name found in scoped lint: `rustdoc::broken_intra_doc_links` ```)
- keeping the link as an anchor `#method.sort_by_key` meant a dead link
- an absolute link would work but doesn't feel right...
Add `-Z unpretty` flag for the THIR
This adds a new perma-unstable flag, `-Zunpretty=thir-tree`, that dumps the raw THIR tree for each body in the crate.
Implements the THIR part of MCP rust-lang/compiler-team#408, helps with rust-lang/rustc-dev-guide#1062.
Depends on #82495, blocked on that. Only the two last commits are added by this PR.
r? ```@spastorino``` cc ```@estebank```
Rustdoc Json: Add tests for Reexports, and improve jsondocck
The two changes are orthognal, so you can land just one if you want, but the improved errors realy helped write the tests.
Notably does not have the case from #80664, but I want to have all the ajacent cases tested before starting work on that to ensure I dont break anything.
Improves #81359
cc ```@CraftSpider```
r? ```@jyn514```
```@rustbot``` modify labels: +A-testsuite +T-rustdoc +A-rustdoc-json
