Revert "Revert "Allow dynamic linking for iOS/tvOS targets.""
This reverts commit 16e10bf81ee73f61cf813acef3d5dbbce4f66da2 (PR #77716).
The original original PR enabled `cdylib` builds for iOS. However this caused problems because:
> This new feature in Rust 1.46 added a lot of headache for iOS builds with cdylib targets. cdylib target is near impossible to build if you are using any crate with native dependencies (ex. openssl, libsodium, zmq). You can't just find .so files for all architectures to perform correct linking. Usual workflow is the following:
>
> 1. You build staticlib and rely that native dependencies will be linked as frameworks later
> 2. You setup right cocoapods in ObjectiveC/Swift wrapper.
>
> As cargo doesn't support platform-dependent crate types https://github.com/rust-lang/rust/pull/4881 as a result a lot of projects now broken on Rust 1.46
However, this will be soon a thing of the past since 1.64 brings us the long awaited much anticipated `--crate-type` flag.
> I see that this got merged recently: https://github.com/rust-lang/cargo/issues/10083. The --crate-type flag will get stabilized in 1.64. In 1.64, you could still get a successful iOS staticlib with cargo build --crate-type=statclib even if the crate has cdylib targets too. If I'm not mistaken, this solves the problem too so this PR could be reverted in 1.64 with relatively little headache.
So summing up, I think this PR can be reverted in 1.64. 🤞
add miri-test-libstd support to libstd
- The first commit mirrors what we already have in liballoc.
- The second commit adds some regression tests that only really make sense to be run in Miri, since they rely on Miri's extra checks to detect anything.
- The third commit makes the MPSC tests work in reasonable time in Miri by reducing iteration counts.
- The fourth commit silences some warnings due to code being disabled with `cfg(miri)`
Reenable disabled early syntax gates as future-incompatibility lints
- MCP: https://github.com/rust-lang/compiler-team/issues/535
The approach taken by this PR is
- Introduce a new lint, `unstable_syntax_pre_expansion`, and reenable the early syntax gates to emit it
- Use the diagnostic stashing mechanism to stash warnings the early warnings
- When the hard error occurs post expansion, steal and cancel the early warning
- Don't display any stashed warnings if errors are present to avoid the same noise problem that hiding type ascription errors is avoiding
Commits are working commits, but in a coherent steps-to-implement manner. Can be squashed if desired.
The preexisting `soft_unstable` lint seems like it would've been a good fit, but it is deny-by-default (appropriate for `#[bench]`) and these gates should be introduced as warn-by-default.
It may be desirable to change the stash mechanism's behavior to not flush lint errors in the presence of other errors either (like is done for warnings here), but upgrading a stash-using lint from warn to error perhaps is enough of a request to see the lint that they shouldn't be hidden; additionally, fixing the last error to get new errors thrown at you always feels bad, so if we know the lint errors are present, we should show them.
Using a new flag/mechanism for a "weak diagnostic" which is suppressed by other errors may also be desirable over assuming any stashed warnings are "weak," but this is the first user of stashing warnings and seems an appropriate use of stashing (it follows the "know more later to refine the diagnostic" pattern; here we learn that it's in a compiled position) so we get to define what it means to stash a non-hard-error diagnostic.
cc `````@petrochenkov````` (seconded MCP)
Rollup of 10 pull requests
Successful merges:
- #100186 (Mention `as_mut` alongside `as_ref` in borrowck error message)
- #100383 (Mitigate stale data reads on SGX platform)
- #100507 (suggest `once_cell::Lazy` for non-const statics)
- #100617 (Suggest the right help message for as_ref)
- #100667 (Migrate "invalid variable declaration" errors to SessionDiagnostic)
- #100709 (Migrate typeck's `used` expected symbol diagnostic to `SessionDiagnostic`)
- #100723 (Add the diagnostic translation lints to crates that don't emit them)
- #100729 (Avoid zeroing a 1kb stack buffer on every call to `std::sys::windows::fill_utf16_buf`)
- #100750 (improved diagnostic for function defined with `def`, `fun`, `func`, or `function` instead of `fn`)
- #100763 (triagebot: Autolabel `A-rustdoc-json`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Avoid zeroing a 1kb stack buffer on every call to `std::sys::windows::fill_utf16_buf`
I've also tried to be slightly more careful about integer overflows, although in practice this is likely still not handled ideally.
r? `@ChrisDenton`
Add the diagnostic translation lints to crates that don't emit them
Some of these have a note saying that they should build on a stable compiler, does that mean they shouldn't get these lints? Or can we cfg them out on those?
Migrate "invalid variable declaration" errors to SessionDiagnostic
After seeing the great blog post on Inside Rust, I decided to try my hand at this. Just one diagnostic for now to get used to the workflow and to check if this is the way to do it or if there are any problems.
suggest `once_cell::Lazy` for non-const statics
Addresses https://github.com/rust-lang/rust/issues/100410
Some questions:
- removing the `if` seems to include too many cases (e.g. calls to non-const functions inside a `const fn`), but this code excludes the following case:
```rust
const FOO: Foo = non_const_fn();
```
Should we suggest `once_cell` in this case as well?
- The original issue mentions suggesting `AtomicI32` instead of `Mutex<i32>`, should this PR address that as well?
Mention `as_mut` alongside `as_ref` in borrowck error message
Kinda fixes#99426 but I guess that really might be better staying open to see if we could make it suggest `as_mut` in a structured way. Not sure how to change borrowck to know that info tho.
Rollup of 9 pull requests
Successful merges:
- #99576 (Do not allow `Drop` impl on foreign fundamental types)
- #100081 (never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn))
- #100208 (make NOP dyn casts not require anything about the vtable)
- #100494 (Cleanup rustdoc themes)
- #100522 (Only check the `DefId` for the recursion check in MIR inliner.)
- #100592 (Manually implement Debug for ImportKind.)
- #100598 (Don't fix builtin index when Where clause is found)
- #100721 (Add diagnostics lints to `rustc_type_ir` module)
- #100731 (rustdoc: count deref and non-deref as same set of used methods)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Lazily decode SourceFile from metadata
Currently, source files from foreign crates are decoded up-front from metadata.
Spans from those crates were matched with the corresponding source using binary search among those files.
This PR changes the strategy by matching spans to files during encoding. This allows to decode source files on-demand, instead of up-front. The on-disk format for spans becomes: `<tag> <position from start of file> <length> <file index> <crate (if foreign file)>`.
Don't fix builtin index when Where clause is found
Where clause shadows blanket impl for `Index` which causes normalization to not occur, which causes ICE to happen when we typeck.
r? `@compiler-errors`
Fixes#91633
Cleanup rustdoc themes
This PR continues our work to simplify the rustdoc themes by relying more on CSS variables. Interestingly enough, this time it allowed me to realize that we were having a lot of different colors for borders even though the difference is unnoticeable. I used this opportunity to unify them.
The live demo is [here](https://rustdoc.crud.net/imperio/cleanup-themes/std/index.html).
r? `@jsha`
never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn)
Judging from https://github.com/rust-lang/rust/issues/71668#issuecomment-1200317370 the consensus nowadays seems to be that we should never consider an unsafe block unused if it was required with `deny(unsafe_op_in_unsafe_fn)`, no matter whether that lint is actually enabled or not. So let's adjust rustc accordingly.
The first commit does the change, the 2nd does some cleanup.
Do not allow `Drop` impl on foreign fundamental types
`Drop` should not be implemented on `Pin<T>` even if `T` is local.
This does not trigger regular orphan rules is because `Pin` is `#[fundamental]`... but we don't allow specialized `Drop` impls anyways, so these rules are not sufficient to prevent this impl on stable. Let's just choose even stricter rules, since we shouldn't be implementing `Drop` on a foreign ADT ever.
Fixes#99575
Refactor iteration logic in the `Flatten` and `FlatMap` iterators
The `Flatten` and `FlatMap` iterators both delegate to `FlattenCompat`:
```rust
struct FlattenCompat<I, U> {
iter: Fuse<I>,
frontiter: Option<U>,
backiter: Option<U>,
}
```
Every individual iterator method that `FlattenCompat` implements needs to carefully manage this state, checking whether the `frontiter` and `backiter` are present, and storing the current iterator appropriately if iteration is aborted. This has led to methods such as `next`, `advance_by`, and `try_fold` all having similar code for managing the iterator's state.
I have extracted this common logic of iterating the inner iterators with the option to exit early into a `iter_try_fold` method:
```rust
impl<I, U> FlattenCompat<I, U>
where
I: Iterator<Item: IntoIterator<IntoIter = U>>,
{
fn iter_try_fold<Acc, Fold, R>(&mut self, acc: Acc, fold: Fold) -> R
where
Fold: FnMut(Acc, &mut U) -> R,
R: Try<Output = Acc>,
{ ... }
}
```
It passes each of the inner iterators to the given function as long as it keep succeeding. It takes care of managing `FlattenCompat`'s state, so that the actual `Iterator` methods don't need to. The resulting code that makes use of this abstraction is much more straightforward:
```rust
fn next(&mut self) -> Option<U::Item> {
#[inline]
fn next<U: Iterator>((): (), iter: &mut U) -> ControlFlow<U::Item> {
match iter.next() {
None => ControlFlow::CONTINUE,
Some(x) => ControlFlow::Break(x),
}
}
self.iter_try_fold((), next).break_value()
}
```
Note that despite being implemented in terms of `iter_try_fold`, `next` is still able to benefit from `U`'s `next` method. It therefore does not take the performance hit that implementing `next` directly in terms of `Self::try_fold` causes (in some benchmarks).
This PR also adds `iter_try_rfold` which captures the shared logic of `try_rfold` and `advance_back_by`, as well as `iter_fold` and `iter_rfold` for folding without early exits (used by `fold`, `rfold`, `count`, and `last`).
Benchmark results:
```
before after
bench_flat_map_sum 423,255 ns/iter 414,338 ns/iter
bench_flat_map_ref_sum 1,942,139 ns/iter 2,216,643 ns/iter
bench_flat_map_chain_sum 1,616,840 ns/iter 1,246,445 ns/iter
bench_flat_map_chain_ref_sum 4,348,110 ns/iter 3,574,775 ns/iter
bench_flat_map_chain_option_sum 780,037 ns/iter 780,679 ns/iter
bench_flat_map_chain_option_ref_sum 2,056,458 ns/iter 834,932 ns/iter
```
I added the last two benchmarks specifically to demonstrate an extreme case where `FlatMap::next` can benefit from custom internal iteration of the outer iterator, so take it with a grain of salt. We should probably do a perf run to see if the changes to `next` are worth it in practice.
rustc_metadata: dedupe strings to prevent multiple copies in rmeta/query cache blow file size
r? `@cjgillot`
Encodes strings in rmeta/query cache so duplicated ones will be encoded as offsets to first strings, reducing file size.
Reword "Required because of the requirements on the impl of ..."
Rephrases the awkward "Required because of the requirements on the impl of `{trait}` for `{type}`" to "required for `{type}` to implement `{trait}`"
Revert "Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, …
…r=oli-obk"
This reverts commit c703d11dccb4a895c7aead3b2fcd8cea8c483184, reversing
changes made to 64eb9ab869bc3f9ef3645302fbf22e706eea16cf.
it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).
r? `@pnkfelix`
fixes#99536
