Use a lock-free datastructure for source_span
follow up to the perf regression in https://github.com/rust-lang/rust/pull/105462
The main regression is likely the CStore, but let's evaluate the perf impact of this on its own
compiletest: up deps
update `miow` 0.3.7 -> 0.5.0 (which moved from `winapi` to `windows-rs`, [changelog](https://github.com/yoshuawuyts/miow/blob/master/CHANGELOG.md#v050---2022-11-10))
replace `lazy_static` with `once_cell` (there is slow transition to the second crate, in hope of eventually stable stdlib version, yes?)
Use DefKind to give more item kind information during BindingObligation note
The current label says "required by a bound in this". When I see that label, my immediate impression is "this... **what**?". It feels like it was cut short.
Alternative to this would be saying "in this item", but adding the item kind is strictly more informational and adds very little overhead to the existing error presentation.
Better debug logs for borrowck constraint graph
It's really cumbersome to work with `RegionVar`s when trying to debug borrowck code or when trying to understand how the borrowchecker works. This PR collects some region information (behind `cfg(debug_assertions)`) for created `RegionVar`s (NLL region vars, this PR doesn't touch canonicalization) and prints the nodes and edges of the strongly connected constraints graph using representatives that use that region information (either lifetime names, locations in MIR or spans).
Linker: use -z <params> instead of -z<params>
The GNU linker accepts -z<params>, but this is undocumented, and not supported by other linkers.
In particular, `zig cc`, when used as the C compiler/linker (e.g. when using `cargo-zigbuild`), will not accept this undocumented syntax.
In `linker.rs`, both syntaxes are also used inconsistently.
The Go compiler used to have the same issue, but fixed it:
38607c5538
Make hidden type registration opt-in, so that each site can be reviewed on its own and we have the right defaults for trait solvers
r? `@lcnr`
pulled out of https://github.com/rust-lang/rust/pull/107891 as it is the uncontroversial part
The GNU linker accepts -z<params>, but this is undocumented, and
not supported by other linkers.
In particular, `zig cc`, when used as the C compiler/linker
(e.g. when using `cargo-zigbuild`), will not accept this
undocumented syntax.
In `linker.rs`, both syntaxes are also used inconsistently.
The Go compiler used to have the same issue, but fixed it:
38607c5538
Move `Fn*` traits malformedness protections to typeck
I found it strange that we were doing a custom well-formedness check just for the `Fn*` traits' `call_*` fn items. My understanding from the git history is that this is just to avoid ICEs later on in typeck.
Well, that well-formedness check isn't even implemented correctly for `FnOnce::call_once`, or `FnMut::call_mut` for that matter. Instead, this PR just makes the typeck checks more robust, and leaves it up to the call-site to report errors when lang items are implemented in funny ways.
This coincidentally fixes another ICE where a the `Add` lang item is implemented with a `add` item that's a const instead of a method.
Add a test for default trait method with RPITITs
This didn't work in #107013, but now that #108203 has landed, let's make sure we don't regress it.
r? types
Name placeholder in some region errors
Also don't print `ReVar` or `ReLateBound` as debug... these error messages are super uncommon anyways, but in the case they do trigger, let's be slightly more helpful.
remove unstable `pick_stable_methods_before_any_unstable` flag
This flag was only added in #90329 in case there was any issue with the impl so that it would be easy to tell nightly users to use the flag to disable the new logic to fix their code. It's now been enabled for two years and also I can't find any issues corresponding to this new functionality? This flag made it way harder to understand how this code works so it would be nice to remove it and simplify what's going on.
cc `@nbdd0121`
r? `@oli-obk`
docs: wrong naming convention in struct keyword doc
Noticed that the naming convention mentioned is not the right one.
As far as I know, PacalCase is the naming convention used for structs names. PacalCase is not the same as camelCase
Add rpitit queries
This is part of the changes we are making to lower RPITITs as an associated type. The rest of the stuff will follow under a `-Z` flag.
I still need to add comments to the code, explain stuff and also I'd need to avoid encoding in metadata when rpitit queries return `&[]`
r? `@compiler-errors`
Explain the default panic hook better
This changes the documentation of `std::panic::set_hook` and `take_hook` to explain how the default panic hook works. In particular the fact that `take_hook` registers the default hook, rather than no hook at all, was missing from the docs.
I also reworded a few things for clarity.
lint: don't suggest MaybeUninit::assume_init for uninhabited types
Creating a zeroed uninhabited type such as `!` or an empty enum with `mem::zeroed()` (or transmuting `()` to `!`) currently triggers this lint:
```rs
warning: the type `!` does not permit zero-initialization
--> test.rs:5:23
|
5 | let _val: ! = mem::zeroed();
| ^^^^^^^^^^^^^
| |
| this code causes undefined behavior when executed
| help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
|
= note: the `!` type has no valid value
```
The `MaybeUninit` suggestion in the help message seems confusing/useless for uninhabited types, as such a type cannot be fully initialized in the first place (as the note implies).
This PR limits this help message to inhabited types which can be initialized
Miri: basic dyn* support
As usual I am very unsure about the dynamic dispatch stuff, but it passes even the `Pin<&mut dyn* Trait>` test so that is something.
TBH I think it was a mistake to make `dyn Trait` and `dyn* Trait` part of the same `TyKind` variant. Almost everywhere in Miri this lead to the wrong default behavior, resulting in strange ICEs instead of nice "unimplemented" messages. The two types describe pretty different runtime data layout after all.
Strangely I did not need to do the equivalent of [this diff](https://github.com/rust-lang/rust/pull/106532#discussion_r1087095963) in Miri. Maybe that is because the unsizing logic matches on `ty::Dynamic(.., ty::Dyn)` already? In `unsized_info` I don't think the `target_dyn_kind` can be `DynStar`, since then it wouldn't be unsized!
r? `@oli-obk` Cc `@eholk` (dyn-star) https://github.com/rust-lang/rust/issues/102425
