Disentangle `ForwardGenericParamBan` and `ConstParamTy` ribs
In #137617, the `ConstParamTy` rib was adjusted to act kinda like the `ForwardGenericParamBan`. However, this means that it no longer served its purpose banning generics from *parent items*. Although we still are checking for param type validity using the `ConstParamTy_` trait, which means that we weren't accepting code we shouldn't, I think it's a bit strange for us not to be rejecting code like this during *resolution* and instead letting these malformed const generics leak into the type system:
```rust
trait Foo<T> {
fn bar<const N: T>() {}
}
```
This PR does a few things:
1. Introduce a `ForwardGenericParamBanReason` enum, and start using the `ForwardGenericParamBan` rib to ban forward-declared params in const tys when `generic_const_parameter_types` is enabled.
2. Start using the `ConstParamTy` rib to ban *all* generics when `generic_const_parameter_types` is disabled.
3. Improve the diagnostics for both of the cases above, and for forward-declared params in parameter defaults too :3
r? `@BoxyUwU` or reassign
Support rmeta inputs for --crate-type=bin --emit=obj
This already works for --emit=metadata, but is possible anytime we're not linking.
Tests:
- `rmeta_bin` checks we're not changing --emit=link (already passes)
- `rmeta_bin-pass` tests the new behavior for --emit=obj (would fail today) and also --emit=metadata which isn't changing
Convert `ShardedHashMap` to use `hashbrown::HashTable`
The `hash_raw_entry` feature (#56167) has finished fcp-close, so the compiler
should stop using it to allow its removal. Several `Sharded` maps were
using raw entries to avoid re-hashing between shard and map lookup, and
we can do that with `hashbrown::HashTable` instead.
change definitely unproductive cycles to error
builds on top of #136824 by adding a third variant to `PathKind` for paths which may change to be coinductive in the future but must not be so right now. Most notably, impl where-clauses of not yet coinductive traits.
With this, we can change cycles which are definitely unproductive to a proper error. This fixes https://github.com/rust-lang/trait-system-refactor-initiative/issues/114. This does not affect stable as we keep these cycles as ambiguous during coherence.
r? ````````@compiler-errors```````` ````````@nikomatsakis````````
Fix false-positive in `expr_or_init` and in the `invalid_from_utf8` lint
This PR fixes the logic for finding initializer in the `expr_or_init` and `expr_or_init_with_outside_body` functions.
If the binding were to be mutable (`let mut`), the logic wouldn't consider that the initializer expression could have been modified and would return the init expression even-trough multiple subsequent assignments could have been done.
Example:
```rust
let mut a = [99, 108, 130, 105, 112, 112]; // invalid, not UTF-8
loop {
a = *b"clippy"; // valid
break;
}
std::str::from_utf8_mut(&mut a); // currently warns, with this PR it doesn't
```
This PR modifies the logic to excludes mutable let bindings.
Found when using `expr_or_init` in https://github.com/rust-lang/rust/pull/119220.
r? compiler
Elaborate trait assumption in `receiver_is_dispatchable`
Fixes#138172. See comment on the linked test.
Probably not a fix for the general problem, bc I think this may still be incomplete for other weird `where` clauses on the receiver. But 🤷, supertraits seems like an obvious one to fix.
Allow bounds checks when enumerating `IndexSlice` to be elided
Without this hint, each loop iteration has to separately bounds check the index. See https://godbolt.org/z/zrfPY4Ten for an example.
This is technically a behaviour change, but only in cases where the compiler is going to crash anyways.
The idea is to identify cases of symbols/identifiers that are not
expected to be used. There isn't a perfectly sharp line between "dummy"
and "not dummy", but I think it's useful nonetheless.
This is never hit in the test suite.
At some point the check should be removed entirely. There are a million
places in the compiler where an empty symbol doesn't make sense, so a
check of this nature has almost zero value. But I'll leave it in place
for now just in case it gets hit by fuzzing or in the wild.
Continuing the work from #137350.
Removes the unused methods: `expect_variant`, `expect_field`,
`expect_foreign_item`.
Every method gains a `hir_` prefix.
To make room for the moving of `Map::attrs` to `TyCtxt::hir_attrs` in
the next commit. (It makes sense to rename the query, because it has
many fewer uses than the method.)
Rollup of 10 pull requests
Successful merges:
- #137715 (Allow int literals for pattern types with int base types)
- #138002 (Disable CFI for weakly linked syscalls)
- #138051 (Add support for downloading GCC from CI)
- #138231 (Prevent ICE in autodiff validation by emitting user-friendly errors)
- #138245 (stabilize `ci_rustc_if_unchanged_logic` test for local environments)
- #138256 (Do not feed anon const a type that references generics that it does not have)
- #138284 (Do not write user type annotation for const param value path)
- #138296 (Remove `AdtFlags::IS_ANONYMOUS` and `Copy`/`Clone` condition for anonymous ADT)
- #138352 (miri native_calls: ensure we actually expose *mutable* provenance to the memory FFI can access)
- #138354 (remove redundant `body` arguments)
r? `@ghost`
`@rustbot` modify labels: rollup
miri native_calls: ensure we actually expose *mutable* provenance to the memory FFI can access
In native call mode, the interpreter memory itself is accessed directly by external code via pointers created from integers and passed via libffi, so we have to ensure the provenance in Miri itself (on the meta level) is sufficiently exposed. So far we only exposed the provenance for read-only accesses. This may we enough as that may actually be the same provenance as for mutable accesses, but it's hard to be sure, and anyway there's no reason to do such a gambit -- we have this function, `prepare_for_native_call`, which iterates all memory the call can access. let's just also (re-)expose Miri's own allocations there. We expose the read-only provenance for all of them and the mutable provenance for the mutable allocations.
r? ``@oli-obk``
Remove `AdtFlags::IS_ANONYMOUS` and `Copy`/`Clone` condition for anonymous ADT
cc #131045, which removed anonymous ADTs from the compiler
I forgot more stuff I guess.
Do not write user type annotation for const param value path
As I noted in the code comment, `DefKind::ConstParam` isn't actually *generic* over its own args, we just use the identity args from the body when lowering the value path so we have something to plug into the `EarlyBinder` we get back from `type_of` for the const param. So skip over it in `write_user_type_annotation_from_args`.
Somewhat unrelated, but I left an explanation for a somewhat mysterious quirk in the THIR lowering of user type annotations for patterns having to do with ctors and their `type_of` not actually being the type of the pattern node it's ascribing.
Fixes#138048
r? ``@BoxyUwU``
Do not feed anon const a type that references generics that it does not have
Fixes#137865
See the comment I left in the code. We could alternatively give these anon consts the generics from the parent, but that would be moving in a GCE-esque direction that we may not want. Open to tweaks here.
r? BoxyUwU
