fix ensure_monomorphic_enough
When polymorphization was still a thing, the visitor was used to only recurse into *used generic parameters* of function/closure/coroutine types and allow unused parameters (i.e. the polymorphized parameters) to remain generic.
When polymorphization got removed, this got changed to always treat all parameters as polymorphic and never recurse into them: https://github.com/rust-lang/rust/pull/133883/files#diff-210c59e321070d0ca4625c04e9fb064bf43ddc34082e7e33a7ee8a6c577e95afL44-L62
This is clearly wrong and can cause MIR opts to misbehave, for example this currently prints "false" in release mode:
```rust
#![feature(core_intrinsics)]
fn generic<T>() {}
const fn type_id_of_val<T: 'static>(_: &T) -> u128 {
std::intrinsics::type_id::<T>()
}
fn cursed_is_i32<T: 'static>() -> bool {
(const { type_id_of_val(&generic::<T>) } == const { type_id_of_val(&generic::<i32>) })
}
fn main() {
dbg!(cursed_is_i32::<i32>());
}
```
This PR reverts to the old behavior of always treating all types that contain type parameters as too generic, like we used to do without `-Zpolymorphize` before.
~~I'm not including the above as a test case here, because I think there is little value in testing code paths that have been removed and this seems unlikely to regress in a way that would be caught by a regression test, but let me know if you disagree and want me to add a test anyway.~~
Overhaul how contracts are lowered on fn-like bodies
Consolidates all of the contracts lowering logic into `lower_fn_body`, rather than having it be split between `lower_item_kind` and `lower_fn_body`. This should fix#136683.
r? celinval
Stop using span hack for contracts feature gating
The contracts machinery is a pretty straightforward case of an *external* feature using a (perma-unstable) *internal* feature within its implementation. There's no reason why it needs to be implemented any differently than other features by using global span tracking hacks to change whether the internals are gated behind the `contracts` or `contracts_internals` feature gate -- for the case of macro expansions we already have `allow_internal_unstable` for exactly this situation.
This PR changes the internal, perma-unstable AST syntax to use the `contracts_internals` gate always, and adjusts the macro expansion to use the right spans so that `allow_internal_unstable` works correctly.
As a follow-up, there's really no reason to have `contracts` be a *compiler feature* since it's at this point fully a *library feature*; the only reason it's a compiler feature today is so we can mark it as incomplete, but that seems like a weak reason. I didn't do anything in this PR for this.
r? ``@celinval``
cg_llvm: Reduce visibility of some items outside the `llvm` module
Next piece of #135502
This reduces the visibility of items (other than those in the `llvm` module) so that dead code analysis will correctly identify unused items.
Improve examples for file locking
The `lock` and `try_lock` documentation states that "if the file not open for writing, it is unspecified whether this function returns an error." With this change, the examples use `File::create` instead of `File::open`, eliminating the possibility of someone blindly copying code with unspecified behavior.
Fix long lines which rustfmt fails to format
rustfmt fails to format this match expression, because it has several long string literals over the maximum line width. This seems to exhibit rustfmt issues [#3863](https://github.com/rust-lang/rustfmt/issues/3863) (Gives up on chains if any line is too long) and [#3156](https://github.com/rust-lang/rustfmt/issues/3156) (Fail to format match arm when other arm has long line).
Format it with a large line width (e.g., by setting `max_width = 200` in rustfmt.toml) and, in case the rustfmt bugs are later fixed, mark it with `#[rustfmt::skip]`, as it is more legible with each case on one line.
The following is a weird pattern for a file within `rustc_middle`:
```
use rustc_middle::aaa;
use crate::bbb;
```
More sensible and standard would be this:
```
use crate::{aaa, bbb};
```
I.e. we generally prefer using `crate::` to using a crate's own name.
(Exceptions are things like in macros where `crate::` doesn't work
because the macro is used in multiple crates.)
This commit fixes a bunch of these weird qualifiers.
rustfmt fails to format this match expression, because it has several
long string literals over the maximum line width. This seems to exhibit
rustfmt issues #3863 (Gives up on chains if any line is too long) and
#3156 (Fail to format match arm when other arm has long line).
Show diff suggestion format on verbose replacement
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL - let _ = 2.l;
LL + let _ = 2.0f64;
|
```
before:
```
error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields
--> $DIR/attempted-access-non-fatal.rs:7:15
|
LL | let _ = 2.l;
| ^
|
help: if intended to be a floating point literal, consider adding a `0` after the period and a `f64` suffix
|
LL + let _ = 2.0f64;
| ~~~~
```
r? `@oli-obk`
