suggest `once_cell::Lazy` for non-const statics
Addresses https://github.com/rust-lang/rust/issues/100410
Some questions:
- removing the `if` seems to include too many cases (e.g. calls to non-const functions inside a `const fn`), but this code excludes the following case:
```rust
const FOO: Foo = non_const_fn();
```
Should we suggest `once_cell` in this case as well?
- The original issue mentions suggesting `AtomicI32` instead of `Mutex<i32>`, should this PR address that as well?
Mention `as_mut` alongside `as_ref` in borrowck error message
Kinda fixes#99426 but I guess that really might be better staying open to see if we could make it suggest `as_mut` in a structured way. Not sure how to change borrowck to know that info tho.
Rollup of 9 pull requests
Successful merges:
- #99576 (Do not allow `Drop` impl on foreign fundamental types)
- #100081 (never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn))
- #100208 (make NOP dyn casts not require anything about the vtable)
- #100494 (Cleanup rustdoc themes)
- #100522 (Only check the `DefId` for the recursion check in MIR inliner.)
- #100592 (Manually implement Debug for ImportKind.)
- #100598 (Don't fix builtin index when Where clause is found)
- #100721 (Add diagnostics lints to `rustc_type_ir` module)
- #100731 (rustdoc: count deref and non-deref as same set of used methods)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Lazily decode SourceFile from metadata
Currently, source files from foreign crates are decoded up-front from metadata.
Spans from those crates were matched with the corresponding source using binary search among those files.
This PR changes the strategy by matching spans to files during encoding. This allows to decode source files on-demand, instead of up-front. The on-disk format for spans becomes: `<tag> <position from start of file> <length> <file index> <crate (if foreign file)>`.
Don't fix builtin index when Where clause is found
Where clause shadows blanket impl for `Index` which causes normalization to not occur, which causes ICE to happen when we typeck.
r? `@compiler-errors`
Fixes#91633
Cleanup rustdoc themes
This PR continues our work to simplify the rustdoc themes by relying more on CSS variables. Interestingly enough, this time it allowed me to realize that we were having a lot of different colors for borders even though the difference is unnoticeable. I used this opportunity to unify them.
The live demo is [here](https://rustdoc.crud.net/imperio/cleanup-themes/std/index.html).
r? `@jsha`
never consider unsafe blocks unused if they would be required with deny(unsafe_op_in_unsafe_fn)
Judging from https://github.com/rust-lang/rust/issues/71668#issuecomment-1200317370 the consensus nowadays seems to be that we should never consider an unsafe block unused if it was required with `deny(unsafe_op_in_unsafe_fn)`, no matter whether that lint is actually enabled or not. So let's adjust rustc accordingly.
The first commit does the change, the 2nd does some cleanup.
Do not allow `Drop` impl on foreign fundamental types
`Drop` should not be implemented on `Pin<T>` even if `T` is local.
This does not trigger regular orphan rules is because `Pin` is `#[fundamental]`... but we don't allow specialized `Drop` impls anyways, so these rules are not sufficient to prevent this impl on stable. Let's just choose even stricter rules, since we shouldn't be implementing `Drop` on a foreign ADT ever.
Fixes#99575
Revert "Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, …
…r=oli-obk"
This reverts commit c703d11dcc, reversing
changes made to 64eb9ab869.
it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).
r? `@pnkfelix`
fixes#99536
Don't derive `PartialEq::ne`.
Currently we skip deriving `PartialEq::ne` for C-like (fieldless) enums
and empty structs, thus reyling on the default `ne`. This behaviour is
unnecessarily conservative, because the `PartialEq` docs say this:
> Implementations must ensure that eq and ne are consistent with each other:
>
> `a != b` if and only if `!(a == b)` (ensured by the default
> implementation).
This means that the default implementation (`!(a == b)`) is always good
enough. So this commit changes things such that `ne` is never derived.
The motivation for this change is that not deriving `ne` reduces compile
times and binary sizes.
Observable behaviour may change if a user has defined a type `A` with an
inconsistent `PartialEq` and then defines a type `B` that contains an
`A` and also derives `PartialEq`. Such code is already buggy and
preserving bug-for-bug compatibility isn't necessary.
Two side-effects of the change:
- There is only one error message produced for types where `PartialEq`
cannot be derived, instead of two.
- For coverage reports, some warnings about generated `ne` methods not
being executed have disappeared.
Both side-effects seem fine, and possibly preferable.
Make must_not_suspend lint see through references when drop tracking is enabled
See #97333.
With drop tracking enabled, sometimes values that were previously linted are now considered dropped and not linted. This change makes must_not_suspend traverse through references to still catch these values.
Unfortunately, this leads to duplicate warnings in some cases (e.g. [dedup.rs](9a74608543/src/test/ui/lint/must_not_suspend/dedup.rs (L4))), so we only use the new behavior when drop tracking is enabled.
cc ``@guswynn``
Remove deferred sized checks (make them eager)
Improves diagnostics spans... this doesn't seem to be the case anymore:
```rust
// Some additional `Sized` obligations badly affect type inference.
// These obligations are added in a later stage of typeck.
pub(super) deferred_sized_obligations:
RefCell<Vec<(Ty<'tcx>, Span, traits::ObligationCauseCode<'tcx>)>>,
```
Do not report cycle error when inferring return type for suggestion
The UI test is a good example of a case where this happens. The cycle is due to needing the value of the return type `-> _` to compute the variances of items in the crate, but then needing the variances of the items in the crate to do typechecking to infer what `-> _`'s real type is.
Since we're already gonna emit an error in astconv, just delay the cycle bug as an error.
Rustdoc json tests: New @hasexact test command
Alot of the time, we wanted to assert that a module had an exact set of items. Most of the time this was done by asserting that the ```@count``` of the module was `n`, and then doing `n` ```@has``` checks on the module.
This was tedious, so often shortcuts were done.
This PR adds a new command to jsondocck to allow consistently expressing this behavior, and then uses it to clean up the tests.
``@rustbot`` modify labels: +A-rustdoc-json +A-testsuite
Fix nonsense non-tupled `Fn` trait error
Given this code:
```rust
#![feature(unboxed_closures)]
fn a<F: Fn<usize>>(f: F) {}
fn main() {
a(|_: usize| {});
}
```
We currently emit this error:
```
error[E0631]: type mismatch in closure arguments
--> src/main.rs:6:5
|
6 | a(|_: usize| {});
| ^ ---------- found signature of `fn(usize) -> _`
| |
| expected signature of `fn(usize) -> _`
|
note: required by a bound in `a`
--> src/main.rs:3:9
|
3 | fn a<F: Fn<usize>>(f: F) {}
| ^^^^^^^^^ required by this bound in `a`
For more information about this error, try `rustc --explain E0631`.
error: could not compile `playground` due to previous error
```
Notably, it says the same thing for "expected" and "found"!
Fix the output so that we instead emit:
```
error[E0308]: mismatched types
--> /home/gh-compiler-errors/test.rs:6:5
|
6 | a(|_: usize| {});
| ^ types differ
|
= note: expected trait `Fn<usize>`
found trait `Fn<(usize,)>`
note: required by a bound in `a`
--> /home/gh-compiler-errors/test.rs:3:9
|
3 | fn a<F: Fn<usize>>(f: F) {}
| ^^^^^^^^^ required by this bound in `a`
error: aborting due to previous error
```
The error could still use some work, namely the "mismatched types" part, but I'm leaving it a bit rough since the only way you'd ever get this error is when you're messing with `#![feature(unboxed_closures)]`.
Simply making sure we actually print out the difference in trait-refs is good enough for me. I could probably factor in some additional improvements if those are desired.
Update the minimum external LLVM to 13
With this change, we'll have stable support for LLVM 13 through 15 (pending release).
For reference, the previous increase to LLVM 12 was #90175.
r? `@nagisa`
Add support for generating unique profraw files by default when using `-C instrument-coverage`
Currently, enabling the rustc flag `-C instrument-coverage` instruments the given crate and by default uses the naming scheme `default.profraw` for any instrumented profile files generated during the execution of a binary linked against this crate. This leads to multiple binaries being executed overwriting one another and causing only the last executable run to contain actual coverage results.
This can be overridden by manually setting the environment variable `LLVM_PROFILE_FILE` to use a unique naming scheme.
This PR adds a change to add support for a reasonable default for rustc to use when enabling coverage instrumentation similar to how the Rust compiler treats generating these same `profraw` files when PGO is enabled.
The new naming scheme is set to `default_%m_%p.profraw` to ensure the uniqueness of each file being generated using [LLVMs special pattern strings](https://clang.llvm.org/docs/SourceBasedCodeCoverage.html#running-the-instrumented-program).
Today the compiler sets the default for PGO `profraw` files to `default_%m.profraw` to ensure a unique file for each run. The same can be done for the instrumented profile files generated via the `-C instrument-coverage` flag as well which LLVM has API support for.
Linked Issue: https://github.com/rust-lang/rust/issues/100381
r? `@wesleywiser`
when there are 3 or more return statements in the loop
emit the first 3 errors and duplicated diagnostic information
modified: compiler/rustc_typeck/src/check/coercion.rs
new file: src/test/ui/typeck/issue-100285.rs
new file: src/test/ui/typeck/issue-100285.stderr
emit the first 3 errors and duplicated diagnostic information
using take of iterator for the first third return
modified: compiler/rustc_typeck/src/check/coercion.rs
new file: src/test/ui/typeck/issue-100285.rs
new file: src/test/ui/typeck/issue-100285.stderr
