forked from rust-lang/rust
-
Notifications
You must be signed in to change notification settings - Fork 7
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Auto merge of rust-lang#77517 - JohnTitor:rollup-msbd49e, r=JohnTitor
Rollup of 11 pull requests Successful merges: - rust-lang#75143 (Use `tracing` spans to trace the entire MIR interp stack) - rust-lang#75699 (Uplift drop-bounds lint from clippy) - rust-lang#76768 (Test and reject out-of-bounds shuffle vectors) - rust-lang#77190 (updated p! macro to accept literals) - rust-lang#77388 (Add some regression tests) - rust-lang#77419 (Create E0777 error code for invalid argument in derive) - rust-lang#77447 (BTreeMap: document DrainFilterInner better) - rust-lang#77468 (Fix test name) - rust-lang#77469 (Improve rustdoc error for failed intra-doc link resolution) - rust-lang#77473 (Make --all-targets in x.py check opt-in) - rust-lang#77508 (Fix capitalization in blog post name) Failed merges: r? `@ghost`
- Loading branch information
Showing
53 changed files
with
866 additions
and
331 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,19 @@ | ||
| A literal value was used inside `#[derive]`. | ||
|
|
||
| Erroneous code example: | ||
|
|
||
| ```compile_fail,E0777 | ||
| #[derive("Clone")] // error! | ||
| struct Foo; | ||
| ``` | ||
|
|
||
| Only paths to traits are allowed as argument inside `#[derive]`. You can find | ||
| more information about the `#[derive]` attribute in the [Rust Book]. | ||
|
|
||
|
|
||
| ``` | ||
| #[derive(Clone)] // ok! | ||
| struct Foo; | ||
| ``` | ||
|
|
||
| [Rust Book]: https://doc.rust-lang.org/book/appendix-03-derivable-traits.html |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,79 @@ | ||
| use crate::LateContext; | ||
| use crate::LateLintPass; | ||
| use crate::LintContext; | ||
| use rustc_hir as hir; | ||
| use rustc_span::symbol::sym; | ||
|
|
||
| declare_lint! { | ||
| /// The `drop_bounds` lint checks for generics with `std::ops::Drop` as | ||
| /// bounds. | ||
| /// | ||
| /// ### Example | ||
| /// | ||
| /// ```rust | ||
| /// fn foo<T: Drop>() {} | ||
| /// ``` | ||
| /// | ||
| /// {{produces}} | ||
| /// | ||
| /// ### Explanation | ||
| /// | ||
| /// `Drop` bounds do not really accomplish anything. A type may have | ||
| /// compiler-generated drop glue without implementing the `Drop` trait | ||
| /// itself. The `Drop` trait also only has one method, `Drop::drop`, and | ||
| /// that function is by fiat not callable in user code. So there is really | ||
| /// no use case for using `Drop` in trait bounds. | ||
| /// | ||
| /// The most likely use case of a drop bound is to distinguish between | ||
| /// types that have destructors and types that don't. Combined with | ||
| /// specialization, a naive coder would write an implementation that | ||
| /// assumed a type could be trivially dropped, then write a specialization | ||
| /// for `T: Drop` that actually calls the destructor. Except that doing so | ||
| /// is not correct; String, for example, doesn't actually implement Drop, | ||
| /// but because String contains a Vec, assuming it can be trivially dropped | ||
| /// will leak memory. | ||
| pub DROP_BOUNDS, | ||
| Warn, | ||
| "bounds of the form `T: Drop` are useless" | ||
| } | ||
|
|
||
| declare_lint_pass!( | ||
| /// Lint for bounds of the form `T: Drop`, which usually | ||
| /// indicate an attempt to emulate `std::mem::needs_drop`. | ||
| DropTraitConstraints => [DROP_BOUNDS] | ||
| ); | ||
|
|
||
| impl<'tcx> LateLintPass<'tcx> for DropTraitConstraints { | ||
| fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) { | ||
| use rustc_middle::ty::PredicateAtom::*; | ||
|
|
||
| let def_id = cx.tcx.hir().local_def_id(item.hir_id); | ||
| let predicates = cx.tcx.explicit_predicates_of(def_id); | ||
| for &(predicate, span) in predicates.predicates { | ||
| let trait_predicate = match predicate.skip_binders() { | ||
| Trait(trait_predicate, _constness) => trait_predicate, | ||
| _ => continue, | ||
| }; | ||
| let def_id = trait_predicate.trait_ref.def_id; | ||
| if cx.tcx.lang_items().drop_trait() == Some(def_id) { | ||
| // Explicitly allow `impl Drop`, a drop-guards-as-Voldemort-type pattern. | ||
| if trait_predicate.trait_ref.self_ty().is_impl_trait() { | ||
| continue; | ||
| } | ||
| cx.struct_span_lint(DROP_BOUNDS, span, |lint| { | ||
| let needs_drop = match cx.tcx.get_diagnostic_item(sym::needs_drop) { | ||
| Some(needs_drop) => needs_drop, | ||
| None => return, | ||
| }; | ||
| let msg = format!( | ||
| "bounds on `{}` are useless, consider instead \ | ||
| using `{}` to detect if a type has a destructor", | ||
| predicate, | ||
| cx.tcx.def_path_str(needs_drop) | ||
| ); | ||
| lint.build(&msg).emit() | ||
| }); | ||
| } | ||
| } | ||
| } | ||
| } |
Oops, something went wrong.