Use `TypingMode` throughout the compiler instead of `ParamEnv`
Hopefully the biggest single PR as part of https://github.com/rust-lang/types-team/issues/128.
## `infcx.typing_env` while defining opaque types
I don't know how'll be able to correctly handle opaque types when using something taking a `TypingEnv` while defining opaque types. To correctly handle the opaques we need to be able to pass in the current `opaque_type_storage` and return constraints, i.e. we need to use a proper canonical query. We should migrate all the queries used during HIR typeck and borrowck where this matters to proper canonical queries. This is
## `layout_of` and `Reveal::All`
We convert the `ParamEnv` to `Reveal::All` right at the start of the `layout_of` query, so I've changed callers of `layout_of` to already use a post analysis `TypingEnv` when encountering it.
ca87b535a0/compiler/rustc_ty_utils/src/layout.rs (L51)
## `Ty::is_[unpin|sized|whatever]`
I haven't migrated `fn is_item_raw` to use `TypingEnv`, will do so in a followup PR, this should significantly reduce the amount of `typing_env.param_env`. At some point there will probably be zero such uses as using the type system while ignoring the `typing_mode` is incorrect.
## `MirPhase` and phase-transitions
When inside of a MIR-body, we can mostly use its `MirPhase` to figure out the right `typing_mode`. This does not work during phase transitions, most notably when transitioning from `Analysis` to `Runtime`:
dae7ac133b/compiler/rustc_mir_transform/src/lib.rs (L606-L625)
All these passes still run with `MirPhase::Analysis`, but we should only use `Reveal::All` once we're run the `RevealAll` pass. This required me to manually construct the right `TypingEnv` in all these passes. Given that it feels somewhat easy to accidentally miss this going forward, I would maybe like to change `Body::phase` to an `Option` and replace it at the start of phase transitions. This then makes it clear that the MIR is currently in a weird state.
r? `@ghost`
This adds documentation for the following existing targets:
s390x-unknown-linux-gnu (Tier 2 with host tools)
s390x-unknown-linux-musl (Tier 3)
I volunteer as maintainer for these targets going forward.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
stability: remove skip_stability_check_due_to_privacy
This was added in https://github.com/rust-lang/rust/pull/38689 to deal with https://github.com/rust-lang/rust/issues/38412. However, even after removing the check, the relevant tests still pass. Let's see if CI finds any other tests that rely on this. If not, it seems like logic elsewhere in the compiler changed so this is not required any more.
the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.
rename rustc_const_stable_intrinsic -> rustc_intrinsic_const_stable_indirect
In https://github.com/rust-lang/rust/pull/120370 this name caused confusion as the author thought the intrinsic was stable. So let's try a different name...
If we can land this before the beta cutoff we can avoid needing `cfg(bootstrap)` for this. ;)
Cc `@compiler-errors` `@saethlin`
Overhaul the `-l` option parser (for linking to native libs)
The current parser for `-l` options has accumulated over time, making it hard to follow. This PR tries to clean it up in several ways.
Key changes:
- This code now gets its own submodule, to slightly reduce clutter in `rustc_session::config`.
- Cleaner division between iterating over multiple `-l` options, and processing each individual one.
- Separate “split” step that breaks up the value string into `[KIND[:MODIFIERS]=]NAME[:NEW_NAME]`, but leaves parsing/validating those parts to later steps.
- This step also gets its own (disposable) unit test, to make sure it works as expected.
- A context struct reduces the burden of parameter passing, and makes it easier to write error messages that adapt to nightly/stable compilers.
- Fewer calls to `nightly_options` helper functions, because at this point we can get the same information from `UnstableOptions` and `UnstableFeatures` (which are downstream of earlier calls to those helper functions).
There should be no overall change in compiler behaviour.
Rwlock downgrade
Tracking Issue: #128203
This PR adds a `downgrade` method for `RwLock` / `RwLockWriteGuard` on all currently supported platforms.
Outstanding questions:
- [x] ~~Does the `futex.rs` change affect performance at all? It doesn't seem like it will but we can't be certain until we bench it...~~
- [x] ~~Should the SOLID platform implementation [be ported over](https://github.com/rust-lang/rust/pull/128219#discussion_r1693470090) to the `queue.rs` implementation to allow it to support downgrades?~~
They are unusual methods. The docs don't really describe the cases when
they might be useful (as opposed to just `get`), and the examples don't
demonstrate the interesting cases at all.
This commit improves the docs and the examples.
Fixup some test directives
- A random comment had somehow been turned into an `//`@`` directive.
- More dubiously I also removed leading spaces from directives in 3 UI tests for consistency. These are the only rustc tests that use that formatting.
r? `@jieyouxu`
Diagnostics for let mut in item context
The diagnostics for `let` at the top level did not account for `let mut`, which [made the error unclear](https://users.rust-lang.org/t/create-a-vector-of-constants-outside-main/121251/1).
I've made the diagnostic always display a link to valid items. I've added dedicated help for `let mut` case that suggests using a `Mutex` (to steer novice users away from the `static mut` trap). Unfortunately, neither the Rust book, nor libstd docs have dedicated section listing all other types for interior-mutable `static`s.
