Make init mask lazy for fully initialized/uninitialized const allocations
There are a few optimization opportunities in the `InitMask` and related const `Allocation`s (e.g. by taking advantage of the fact that it's a bitset that represents initialization, which is often entirely initialized or uninitialized in a single call, or gradually built up, etc).
There's a few overwrites to the same state, multiple writes in a row to the same indices, the RLE scheme for `memcpy` doesn't always compress, etc.
Here, we start with:
- avoiding materializing the bitset's blocks if the allocation is fully initialized/uninitialized
- dealloc blocks when fully overwriting, including when participating in `memcpy`s
- take care of the fixme about allocating blocks of 0s before overwriting them to the expected value
- expanding unit test coverage of the init mask
This should be most visible on benchmarks and crates where const allocations dominate the runtime (like `ctfe-stress-5` of course), but I was especially looking at the worst cases from #93215.
This first change allows the majority of `set_range` calls to stay with a lazy init mask when bootstrapping rustc (not that the init mask is a big part of the process in cpu time or memory usage).
r? `@oli-obk`
I have another in-progress branch where I'll switch the singular initialized/uninitialized value to a watermark, recording the point after which everything is uninitialized. That will take care of cases where full initialization is monotonic and done in multiple steps (e.g. an array of a type without padding), which should then allow the vast majority of const allocations' init masks to stay lazy during bootstrapping (though interestingly I've seen such gradual initialization in both left-to-right and right-to-left directions, and I don't think a single watermark can handle both).
Check for overflow in `assemble_candidates_after_normalizing_self_ty`
Prevents a stack overflow (⚠️❗) in the new solver when we have param-env candidates that look like: `T: Trait<Assoc = <T as Trait>::Assoc>`
The current error message looks bad, but that's because we don't distinguish overflow and other ambiguity errors. I'll break that out into a separate PR since the fix may be controversial.
r? `@lcnr`
Use span of placeholders in format_args!() expansion.
`format_args!("{}", x)` expands to something that contains `Argument::new_display(&x)`. That entire expression was generated with the span of `x`.
After this PR, `&x` uses the span of `x`, but the `new_display` call uses the span of the `{}` placeholder within the format string. If an implicitly captured argument was used like in `format_args!("{x}")`, both use the span of the `{x}` placeholder.
This fixes https://github.com/rust-lang/rust/issues/109576, and also allows for more improvements to similar diagnostics in the future, since the usage of `x` can now be traced to the exact `{}` placeholder that required it to be `Display` (or `Debug` etc.)
rustdoc: Unsupport importing `doc(primitive)` and `doc(keyword)` modules
These are internal features used for a specific purpose, and modules without imports are enough for that purpose.
rustdoc + rustdoc-json support for `feature(non_lifetime_binders)`
Makes `for<T> T: Trait` and `for<const N: usize> ..` in where clause operate correctly.
Fixes#108158
Rollup of 6 pull requests
Successful merges:
- #109149 (Improve error message when writer is forgotten in write and writeln macro)
- #109367 (Streamline fast rejection)
- #109548 (AnnotationColumn struct to fix hard tab column numbers in errors)
- #109694 (do not panic on failure to acquire jobserver token)
- #109705 (new solver: check for intercrate mode when accessing the cache)
- #109708 (Specialization involving RPITITs is broken so ignore the diagnostic differences)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Specialization involving RPITITs is broken so ignore the diagnostic differences
Just bless the corresponding test for `-Zlower-impl-trait-in-trait-to-assoc-ty`
r? `@compiler-errors`
do not panic on failure to acquire jobserver token
Purpose: remove `panic`.
Rust fails to acquire token if an error in build system occurs - environment variable contains incorrect `jobserver-auth`. It isn't ice so compiler shouldn't panic on such error.
Related issue: #46981
Improve error message when writer is forgotten in write and writeln macro
Modified write! macro error message when writer is forgotten as in issue #108713Fixes#108713
r? ``@WaffleLapkin``
Thanks to the combination of #108246 and #108442 it could already remove identity transmutes.
With this PR, it can also simplify them to `IntToInt` casts, `Discriminant` reads, or `Field` projections.
Rollup of 8 pull requests
Successful merges:
- #91793 (socket ancillary data implementation for FreeBSD (from 13 and above).)
- #92284 (Change advance(_back)_by to return the remainder instead of the number of processed elements)
- #102472 (stop special-casing `'static` in evaluation)
- #108480 (Use Rayon's TLV directly)
- #109321 (Erase impl regions when checking for impossible to eagerly monomorphize items)
- #109470 (Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`)
- #109562 (Update ar_archive_writer to 0.1.3)
- #109629 (remove obsolete `givens` from regionck)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add a builtin `FnPtr` trait that is implemented for all function pointers
r? `@ghost`
Rebased version of https://github.com/rust-lang/rust/pull/99531 (plus adjustments mentioned in the PR).
If perf is happy with this version, I would like to land it, even if the diagnostics fix in 9df8e1befb5031a5bf9d8dfe25170620642d3c59 only works for `FnPtr` specifically, and does not generally improve blanket impls.
Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`
Given:
```rust
trait Foo {
type Assoc<T>: PartialEq<Self::Assoc<i32>>;
}
impl Foo for () {
type Assoc<T> = Wrapper<T>;
}
struct Wrapper<T>(T);
impl<T> PartialEq<Wrapper<i32>> for Wrapper<T> { }
```
We add an additional predicate in the `normalize_param_env` in `check_type_bounds` that is used to normalize the GAT's bounds to check them in the impl. Problematically, though, that predicate is constructed to be `for<^0> <() as Foo>::Assoc<^0> => Wrapper<T>`, instead of `for<^0> <() as Foo>::Assoc<^0> => Wrapper<^0>`.
That means `Self::Assoc<i32>` in the bounds that we're checking normalizes to `Wrapper<T>`, instead of `Wrapper<i32>`, and so the bound `Self::Assoc<T>: PartialEq<Self::Assoc<i32>>` normalizes to `Wrapper<T>: PartialEq<Wrapper<T>>`, which does not hold.
Fixes this by properly substituting the RHS of that normalizes predicate that we add to the `normalize_param_env`. That means the bound is properly normalized to `Wrapper<T>: PartialEq<Wrapper<i32>>`, which *does* hold.
---
The second commit in this PR just cleans up some substs stuff and some naming.
r? `@jackh726` cc #87900
Erase impl regions when checking for impossible to eagerly monomorphize items
We were inserting `ReErased` for method substs, but not for impl substs, leading to the call for `subst_and_check_impossible_predicates` being a bit weaker than it should be (since it ignores predicates that need substitution -- incl early-bound regions).
Fixes#109297
stop special-casing `'static` in evaluation
fixes#102360
I have no idea whether this actually removed all places where `'static` matters. Without canonicalization it's very easy to accidentally rely on `'static` again. Blocked on changing the `order_dependent_trait_objects` future-compat lint to a hard error
r? `@nikomatsakis`
Move const trait bounds checks to MIR constck
Fixes#109543. When checking paths in HIR typeck, we don't want to check for const predicates since all we want might just be a function pointer. Therefore we move this to MIR constck and check that bounds are met during MIR constck.
r? `@oli-obk`
Fixes#109543. When checking paths in HIR typeck, we don't want to check
for const predicates since all we want might just be a function pointer.
Therefore we move this to MIR constck and check that bounds are met
during MIR constck.
Fix LVI test post LLVM 16 update
#109474 updated LLVM to 16. This causes the LVI mitigation tests for the `x86_64-fortanix-unknown-sgx` platform to fail. This PR fixes those tests again.
cc: `@jethrogb`
Clarify the 'use a constant in a pattern' error message
```rs
use std::borrow::Cow;
const ERROR_CODE: Cow<'_, str> = Cow::Borrowed("23505");
fn main() {
let x = Cow::from("23505");
match x {
ERROR_CODE => {}
}
}
```
```
error: to use a constant of type `Cow` in a pattern, `Cow` must be annotated with `#[derive(PartialEq, Eq)]`
--> src/main.rs:9:9
|
9 | ERROR_CODE => {}
| ^^^^^^^^^^
error: could not compile `playground` due to previous error
```
It seems helpful to link to StructuralEq in this message. I was a little confused, because `Cow<'_, str>` implements PartialEq and Eq, but they're not derived, which I learned is necessary for structural equality and using constants in patterns (thanks to the Rust community Discord server)
For tests, should I update every occurrence of this message? I see tests where this is still a warning and I'm not sure if I should update those.
Don't skip all directories when tidy-checking
This fixes a regression from https://github.com/rust-lang/rust/pull/108772 which basically made it that tidy style checks only `README.md` and `COMPILER_TESTS.md`.
rustdoc: Fix ICE for intra-doc link on intermediate re-export
Fixes https://github.com/rust-lang/rust/issues/109282.
This PR is based on #109266 as it includes its commit to make this work.
`@petrochenkov:` It was exactly as you predicted, adding the `DefId` to the attributes fixed the error for intermediate re-exports as well. Thanks a lot!
r? `@petrochenkov`
Fix "Directly go to item in search if there is only one result" setting
Part of #66181.
The setting was actually broken, so I fixed it when I added the GUI test.
r? `@notriddle`
Still-further-specializable projections are ambiguous in new solver
Fixes https://github.com/rust-lang/rust/pull/108896/files#r1148450781
r? ``@BoxyUwU`` (though feel free to re-roll)
---
This can be used to create an unsound transmute function with the new solver:
```rust
#![feature(specialization)]
trait Default {
type Id;
fn intu(&self) -> &Self::Id;
}
impl<T> Default for T {
default type Id = T;
fn intu(&self) -> &Self::Id {
self
}
}
fn transmute<T: Default<Id = U>, U: Copy>(t: T) -> U {
*t.intu()
}
use std::num::NonZeroU8;
fn main() {
let s = transmute::<u8, Option<NonZeroU8>>(0);
assert_eq!(s, None);
}
```
Improve "Auto-hide trait implementation documentation" GUI test
Part of #66181.
I'll start working on the `include` command for `browser-ui-test` so we can greatly reduce the duplicated code between setting tests.
r? ``@notriddle``
Permit the MIR inliner to inline diverging functions
This heuristic prevents inlining of `hint::unreachable_unchecked`, which in turn makes `Option/Result::unwrap_unchecked` a bad inlining candidate. I looked through the changes to `core`, `alloc`, `std`, and `hashbrown` by hand and they all seem reasonable. Let's see how this looks in perf...
---
Based on rustc-perf it looks like this regresses ctfe-stress, and the cachegrind diff indicates that this regression is in `InterpCx::statement`. I don't know how to do any deeper analysis because that function is _enormous_ in the try toolchain, which has no debuginfo in it. And a local build produces significantly different codegen for that function, even with LTO.
Upgrade to LLVM 16, again
Relative to the previous attempt in https://github.com/rust-lang/rust/pull/107224:
* Update to GCC 8.5 on dist-x86_64-linux, to avoid std::optional ABI-incompatibility between libstdc++ 7 and 8.
* Cherry-pick 96df79af02.
* Cherry-pick 6fc670e5e3.
r? `@cuviper`
Use poison instead of undef
In cases where it is legal, we should prefer poison values over undef values.
This replaces undef with poison for aggregate construction and for uninhabited types. There are more places where we can likely use poison, but I wanted to stay conservative to start with.
In particular the aggregate case is important for newer LLVM versions, which are not able to handle an undef base value during early optimization due to poison-propagation concerns.
r? `@cuviper`
Implement non-const `Destruct` trait in new solver
Makes it so that we can call stdlib methods like `Option::map` in **non-const** environments, since *many* stdlib methods have `Destruct` bounds 😅
This doesn't bother to implement `const Destruct` yet, but it shouldn't be too hard to do so. Just didn't bother since we already don't have much support for const traits in the new solver anyways. I'd be happy to add skeleton support for `const Destruct`, though, if the reviewer desires.
Return nested obligations from canonical response var unification
Handle alias-eq obligations being emitted from `instantiate_and_apply_query_response` in:
* `EvalCtxt` - by processing the nested obligations in the next loop by `new_goals`
* `FulfillCtxt` - by adding the nested obligations to the fulfillment's pending obligations
* `InferCtxt::evaluate_obligation` - ~~by returning `EvaluationResult::EvaluatedToAmbig` (boo 👎, see the FIXME)~~ same behavior as above, since we use fulfillment and `select_where_possible`
The only one that's truly sketchy is `evaluate_obligation`, but it's not hard to modify this behavior moving forward.
From #109037, I think a smaller repro could be crafted if I were smarter, but I am not, so I just took this from #105878.
r? `@lcnr` cc `@BoxyUwU`
sync LVI tests
The LVI tests for the `x86_64-fortanix-unknown-sgx` target have gotten out of sync. LVI is still mitigated correctly, but the LVI tests need minor modifications. Other (non LVI-related) tests fail when the target applies LVI mitigations as they assume the generated code contains forbidden instructions such as `retq`. These tests are ignored for the sgx environment.
cc: `@jethrogb`
Refine error spans for const args in hir typeck
Improve just a couple of error messages having to do with mismatched consts.
r? `@ghost` i'll put this up when the dependent commits are merged
rustdoc: add support for type filters in arguments and generics
This makes sense, since the search index has the information in it, and it's more useful for function signature searches since a function signature search's item type is, by definition, some type of function (there's more than one, but not very many).
Move useless_anynous_reexport lint into unused_imports
As mentioned in https://github.com/rust-lang/rust/pull/109003, this check should have been merged with `unused_imports` in the start.
r? `@petrochenkov`
