Fix anon const def-creation when macros are involved take 2
Fixes#130321
There were two cases that #129137 did not handle correctly:
- Given a const argument `Foo<{ bar!() }>` in which `bar!()` expands to `N`, we would visit the anon const and then visit the `{ bar() }` expression instead of visiting the macro call. This meant that we would build a def for the anon const as `{ bar!() }` is not a trivial const argument as `bar!()` is not a path.
- Given a const argument `Foo<{ bar!() }>` is which `bar!()` expands to `{ qux!() }` in which `qux!()` expands to `N`, it should not be considered a trivial const argument as `{{ N }}` has two pairs of braces. If we only looked at `qux`'s expansion it would *look* like a trivial const argument even though it is not. We have to track whether we have "unwrapped" a brace already when recursing into the expansions of `bar`/`qux`/any macro
r? `@camelid`
Assert that `explicit_super_predicates_of` and `explicit_item_super_predicates` truly only contains bounds for the type itself
We distinguish _implied_ predicates (anything that is implied from elaborating a trait bound) from _super_ predicates, which are are the subset of implied predicates that share the same self type as the trait predicate we're elaborating. This was originally done in #107614, which fixed a large class of ICEs and strange errors where the compiler expected the self type of a trait predicate not to change when elaborating super predicates.
Specifically, super predicates are special for various reasons: they're the valid candidates for trait upcasting, are the only predicates we elaborate when doing closure signature inference, etc. So making sure that we get this list correct and don't accidentally "leak" any other predicates into this list is quite important.
This PR adds some debug assertions that we're in fact not doing so, and it fixes an oversight in the effect desugaring rework.
Implement Return Type Notation (RTN)'s path form in where clauses
Implement return type notation (RTN) in path position for where clauses. We already had RTN in associated type position ([e.g.](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=627a4fb8e2cb334863fbd08ed3722c09)), but per [the RFC](https://rust-lang.github.io/rfcs/3654-return-type-notation.html#where-rtn-can-be-used-for-now):
> As a standalone type, RTN can only be used as the Self type of a where-clause [...]
Specifically, in order to enable code like:
```rust
trait Foo {
fn bar() -> impl Sized;
}
fn is_send(_: impl Send) {}
fn test<T>()
where
T: Foo,
T::bar(..): Send,
{
is_send(T::bar());
}
```
* In the resolver, when we see a `TyKind::Path` whose final segment is `GenericArgs::ParenthesizedElided` (i.e. `(..)`), resolve that path in the *value* namespace, since we're looking for a method.
* When lowering where clauses in HIR lowering, we first try to intercept an RTN self type via `lower_ty_maybe_return_type_notation`. If we find an RTN type, we lower it manually in a way that respects its higher-ranked-ness (see below) and resolves to the corresponding RPITIT. Anywhere else, we'll emit the same "return type notation not allowed in this position yet" error we do when writing RTN in every other position.
* In `resolve_bound_vars`, we add some special treatment for RTN types in where clauses. Specifically, we need to add new lifetime variables to our binders for the early- and late-bound vars we encounter on the method. This implements the higher-ranked desugaring [laid out in the RFC](https://rust-lang.github.io/rfcs/3654-return-type-notation.html#converting-to-higher-ranked-trait-bounds).
This PR also adds a bunch of tests, mostly negative ones (testing error messages).
In a follow-up PR, I'm going to mark RTN as no longer incomplete, since this PR basically finishes the impl surface that we should initially stabilize, and the RFC was accepted.
cc [RFC 3654](https://github.com/rust-lang/rfcs/pull/3654) and https://github.com/rust-lang/rust/issues/109417
add `extern "C-cmse-nonsecure-entry" fn`
tracking issue #75835
in https://github.com/rust-lang/rust/issues/75835#issuecomment-1183517255 it was decided that using an abi, rather than an attribute, was the right way to go for this feature.
This PR adds that ABI and removes the `#[cmse_nonsecure_entry]` attribute. All relevant tests have been updated, some are now obsolete and have been removed.
Error 0775 is no longer generated. It contains the list of targets that support the CMSE feature, and maybe we want to still use this? right now a generic "this abi is not supported on this platform" error is returned when this abi is used on an unsupported platform. On the other hand, users of this abi are likely to be experienced rust users, so maybe the generic error is good enough.
Correct outdated object size limit
The comment here about 48 bit addresses being enough was written in 2016 but was made incorrect in 2019 by 5-level paging, and then persisted for another 5 years before being noticed and corrected.
The bolding of the "exclusive" part is merely to call attention to something I missed when reading it and doublechecking the math.
try-job: i686-msvc
try-job: test-various
Explain why `non_snake_case` is skipped for binary crates and cleanup tests
- Explain `non_snake_case` lint is skipped for bin crate names because binaries are not intended to be distributed or consumed like library crates (#45127).
- Coalesce the bunch of tests into a single one but with revisions, which is easier to compare the differences for `non_snake_case` behavior with respect to crate types.
Follow-up to #121749 with some more comments and test cleanup.
cc `@saethlin` who bumped into one of the tests and was confused why it was `only-x86_64-unknown-linux-gnu`.
try-job: dist-i586-gnu-i586-i686-musl
Normalize consts in writeback when GCE is enabled
GCE lazily normalizes its unevaluated consts. This PR ensures that, like the new solver with its lazy norm types, we can assume that the writeback results are fully normalized.
This is important since we're trying to eliminate unnecessary calls to `ty::Const::{eval,normalize}` since they won't work with mGCE. Previously, we'd keep those consts unnormalized in writeback all the way through MIR build, and they'd only get normalized if we explicitly called `ty::Const::{eval,normalize}`, or during codegen since that calls `normalize_erasing_regions` (which invokes the `QueryNormalizer`, which evaluates the const accordingly).
This hack can (hopefully obviously) be removed when mGCE is implemented and we yeet the old GCE; it's only reachable with the GCE flag anyways, so I'm not worried about the implications here.
r? `@BoxyUwU`
Add recursion limit to FFI safety lint
Fixes#130310
Now we check against `tcx.recursion_limit()` and raise an error if it the limit is reached instead of overflowing the stack.
bail if there are too many non-region infer vars in the query response
A minimal fix for the hang in nalgebra. If the query response would result in too many distinct non-region inference variables, simply overwrite the result with overflow. This should either happen if the result already has too many distinct type inference variables, or if evaluating the query encountered a lot of ambiguous associated types. In both cases it's straightforward to wait until the aliases are no longer ambiguous and then try again.
r? `@compiler-errors`
Begin experimental support for pin reborrowing
This commit adds basic support for reborrowing `Pin` types in argument position. At the moment it only supports reborrowing `Pin<&mut T>` as `Pin<&mut T>` by inserting a call to `Pin::as_mut()`, and only in argument position (not as the receiver in a method call).
This PR makes the following example compile:
```rust
#![feature(pin_ergonomics)]
fn foo(_: Pin<&mut Foo>) {
}
fn bar(mut x: Pin<&mut Foo>) {
foo(x);
foo(x);
}
```
Previously, you would have had to write `bar` as:
```rust
fn bar(mut x: Pin<&mut Foo>) {
foo(x.as_mut());
foo(x);
}
```
Tracking:
- #130494
r? `@compiler-errors`
The issue-112505-overflow test just extended a case of transmute-fail.rs
so simply put them in the same file.
Then we normalize away other cases of this.
Fix feature name in test
This is meant to test that the `box_patterns` feature isn't active due to the `cfg(FALSE)`, but uses the removed `box_syntax` feature. Fix this so it's testing what it should be.
Get rid of niche selection's dependence on fields's order
Fixes#125630.
Use the optimal niche selection decided in `univariant()` rather than picking niche field manually.
r? `@the8472`
Generating a call to `as_mut()` let to more restrictive borrows than
what reborrowing usually gives us. Instead, we change the desugaring to
reborrow the pin internals directly which makes things more expressive.
Never patterns constitute a read for unsafety
This code is otherwise unsound if we don't emit an unsafety error here. Noticed when fixing #130528, but it's totally unrelated.
r? `@Nadrieril`
Check params for unsafety in THIR
Self-explanatory. I'm not surprised this was overlooked, given the way that THIR visitors work. Perhaps we should provide a better entrypoint.
Fixes#130528
Further improve diagnostics for expressions in pattern position
Follow-up of #118625, see #121697.
```rs
fn main() {
match 'b' {
y.0.0.1.z().f()? as u32 => {},
}
}
```
Before:
```
error: expected one of `=>`, ``@`,` `if`, or `|`, found `.`
--> src/main.rs:3:10
|
3 | y.0.0.1.z().f()? as u32 => {},
| ^ expected one of `=>`, ``@`,` `if`, or `|`
```
After:
```
error: expected a pattern, found an expression
--> src/main.rs:3:9
|
3 | y.0.0.1.z().f()? as u32 => {},
| ^^^^^^^^^^^^^^^^^^^^^^^ arbitrary expressions are not allowed in patterns
|
help: consider moving the expression to a match arm guard
|
3 | val if val == y.0.0.1.z().f()? as u32 => {},
| ~~~ +++++++++++++++++++++++++++++++++
help: consider extracting the expression into a `const`
|
2 + const VAL: /* Type */ = y.0.0.1.z().f()? as u32;
3 ~ match 'b' {
4 ~ VAL => {},
|
help: consider wrapping the expression in an inline `const` (requires `#![feature(inline_const_pat)]`)
|
3 | const { y.0.0.1.z().f()? as u32 } => {},
| +++++++ +
```
---
r? fmease
`@rustbot` label +A-diagnostics +A-parser +A-patterns +C-enhancement
