Add lint clones_into_boxed_slices
#16095
Conversation
rustbot
added
needs-fcp
S-waiting-on-review
|
Lintcheck changes for 1ef6ca9
This comment will be updated if you push new changes |
| let mut sugg = Sugg::hir_with_context(cx, inner, full_span.ctxt(), placeholder, &mut applicability); | ||
|
|
||
| let inner_ty = cx.typeck_results().expr_ty(inner); | ||
| let mut ref_count = count_refs(inner_ty); |
There was a problem hiding this comment.
You can use peel_and_count_ty_refs from clippy_utils::ty:
| let mut ref_count = count_refs(inner_ty); | |
| let mut ref_count = peel_and_count_ty_refs(inner_ty).1 as isize; |
| while ref_count > 0 { | ||
| sugg = sugg.deref(); | ||
| ref_count -= 1; | ||
| } | ||
| while ref_count < 0 { | ||
| sugg = sugg.addr(); | ||
| ref_count += 1; | ||
| } |
There was a problem hiding this comment.
| while ref_count > 0 { | |
| sugg = sugg.deref(); | |
| ref_count -= 1; | |
| } | |
| while ref_count < 0 { | |
| sugg = sugg.addr(); | |
| ref_count += 1; | |
| } | |
| for _ in 0..ref_count { | |
| sugg = sugg.deref(); | |
| } | |
| for _ in 0..-ref_count { | |
| sugg = sugg.addr(); | |
| } |
| ty.is_slice() | ||
| || ty.is_str() | ||
| || ty.is_diag_item(cx, sym::cstr_type) | ||
| || ty.is_diag_item(cx, sym::Path) | ||
| || ty.is_diag_item(cx, sym::OsStr) |
There was a problem hiding this comment.
You should avoid doing multiple lookups:
| ty.is_slice() | |
| || ty.is_str() | |
| || ty.is_diag_item(cx, sym::cstr_type) | |
| || ty.is_diag_item(cx, sym::Path) | |
| || ty.is_diag_item(cx, sym::OsStr) | |
| ty.is_slice() || ty.is_str() || matches!(ty.opt_diag_name(cx.tcx), Some(sym::cstr_type | sym::Path | sym::OsStr)) |
| && [ | ||
| sym::into_boxed_str, | ||
| sym::into_boxed_slice, | ||
| sym::into_boxed_path, | ||
| sym::into_boxed_c_str, | ||
| sym::into_boxed_os_str, | ||
| ] | ||
| .contains(&second_method_path.ident.name) |
There was a problem hiding this comment.
Matching by name is not enough and can lead to false positives. You should ensure that this is an inherent method call and that the receiver type is the one you expect.
As an alternative, since those methods are not diag items, you could add them to clippy_utils::paths.
| if second_method_path.ident.name == sym::into_boxed_path && !inner_ty.is_diag_item(cx, sym::Path) { | ||
| // PathBuf's from(...) can convert from other str types, | ||
| // so Path::new(...) must be used to assure resulting Box is the correct type | ||
| show_lint(cx, full_span, arg, true, Some("Path::new("), "...", Some(")")); |
There was a problem hiding this comment.
show_lint() should know that this suggestion should be degraded to MaybeIncorrect at most, because Path may not be have been imported.
rustbot
added
S-waiting-on-author
| ) { | ||
| let mut applicability = Applicability::MachineApplicable; | ||
|
|
||
| while let ExprKind::AddrOf(BorrowKind::Ref, _, expr) | ExprKind::Unary(UnOp::Deref, expr) = inner.kind { |
There was a problem hiding this comment.
What if someone puts curly brackets around a subexpression, such as &{ foo.to_string() }? That would be an ExprKind::Block with one return expression, defeating this loop.
| impl<'tcx> LateLintPass<'tcx> for ClonesIntoBoxedSlices { | ||
| fn check_expr(&mut self, cx: &LateContext<'tcx>, second_method: &'tcx Expr<'_>) { | ||
| // Is the second method into_boxed_...? | ||
| if let ExprKind::MethodCall(second_method_path, first_method, _, _) = second_method.kind |
There was a problem hiding this comment.
This would certainly be simplified by putting this lint into methods. The matching is basically already done there.
4 participants
Adds new lint
clones_into_boxed_sliceswhich detects clone-like functions followed byinto_boxed_...instead of usingBox::from(...).Closes #15951, closes #15373
changelog: new lint: [
clones_into_boxed_slices]