forked from rust-lang/rust-clippy
-
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
add
manual_slice_fill lint (rust-lang#14082)
close rust-lang#13856 changelog: [`manual_slice_fill`]: new lint
- Loading branch information
Showing
14 changed files
with
433 additions
and
35 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
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,111 @@ | ||
| use clippy_utils::diagnostics::span_lint_and_sugg; | ||
| use clippy_utils::eager_or_lazy::switch_to_eager_eval; | ||
| use clippy_utils::macros::span_is_local; | ||
| use clippy_utils::msrvs::{self, Msrv}; | ||
| use clippy_utils::source::{HasSession, snippet_with_applicability}; | ||
| use clippy_utils::ty::implements_trait; | ||
| use clippy_utils::{higher, peel_blocks_with_stmt, span_contains_comment}; | ||
| use rustc_ast::ast::LitKind; | ||
| use rustc_ast::{RangeLimits, UnOp}; | ||
| use rustc_data_structures::packed::Pu128; | ||
| use rustc_errors::Applicability; | ||
| use rustc_hir::QPath::Resolved; | ||
| use rustc_hir::def::Res; | ||
| use rustc_hir::{Expr, ExprKind, Pat}; | ||
| use rustc_lint::LateContext; | ||
| use rustc_span::source_map::Spanned; | ||
| use rustc_span::sym; | ||
|
|
||
| use super::MANUAL_SLICE_FILL; | ||
|
|
||
| pub(super) fn check<'tcx>( | ||
| cx: &LateContext<'tcx>, | ||
| pat: &'tcx Pat<'_>, | ||
| arg: &'tcx Expr<'_>, | ||
| body: &'tcx Expr<'_>, | ||
| expr: &'tcx Expr<'_>, | ||
| msrv: &Msrv, | ||
| ) { | ||
| if !msrv.meets(msrvs::SLICE_FILL) { | ||
| return; | ||
| } | ||
|
|
||
| // `for _ in 0..slice.len() { slice[_] = value; }` | ||
| if let Some(higher::Range { | ||
| start: Some(start), | ||
| end: Some(end), | ||
| limits: RangeLimits::HalfOpen, | ||
| }) = higher::Range::hir(arg) | ||
| && let ExprKind::Lit(Spanned { | ||
| node: LitKind::Int(Pu128(0), _), | ||
| .. | ||
| }) = start.kind | ||
| && let ExprKind::Block(..) = body.kind | ||
| // Check if the body is an assignment to a slice element. | ||
| && let ExprKind::Assign(assignee, assignval, _) = peel_blocks_with_stmt(body).kind | ||
| && let ExprKind::Index(slice, _, _) = assignee.kind | ||
| // Check if `len()` is used for the range end. | ||
| && let ExprKind::MethodCall(path, recv,..) = end.kind | ||
| && path.ident.name == sym::len | ||
| // Check if the slice which is being assigned to is the same as the one being iterated over. | ||
| && let ExprKind::Path(Resolved(_, recv_path)) = recv.kind | ||
| && let ExprKind::Path(Resolved(_, slice_path)) = slice.kind | ||
| && recv_path.res == slice_path.res | ||
| && !assignval.span.from_expansion() | ||
| // It is generally not equivalent to use the `fill` method if `assignval` can have side effects | ||
| && switch_to_eager_eval(cx, assignval) | ||
| && span_is_local(assignval.span) | ||
| // The `fill` method requires that the slice's element type implements the `Clone` trait. | ||
| && let Some(clone_trait) = cx.tcx.lang_items().clone_trait() | ||
| && implements_trait(cx, cx.typeck_results().expr_ty(slice), clone_trait, &[]) | ||
| { | ||
| sugg(cx, body, expr, slice.span, assignval.span); | ||
| } | ||
| // `for _ in &mut slice { *_ = value; }` | ||
| else if let ExprKind::AddrOf(_, _, recv) = arg.kind | ||
| // Check if the body is an assignment to a slice element. | ||
| && let ExprKind::Assign(assignee, assignval, _) = peel_blocks_with_stmt(body).kind | ||
| && let ExprKind::Unary(UnOp::Deref, slice_iter) = assignee.kind | ||
| && let ExprKind::Path(Resolved(_, recv_path)) = recv.kind | ||
| // Check if the slice which is being assigned to is the same as the one being iterated over. | ||
| && let ExprKind::Path(Resolved(_, slice_path)) = slice_iter.kind | ||
| && let Res::Local(local) = slice_path.res | ||
| && local == pat.hir_id | ||
| && !assignval.span.from_expansion() | ||
| && switch_to_eager_eval(cx, assignval) | ||
| && span_is_local(assignval.span) | ||
| // The `fill` method cannot be used if the slice's element type does not implement the `Clone` trait. | ||
| && let Some(clone_trait) = cx.tcx.lang_items().clone_trait() | ||
| && implements_trait(cx, cx.typeck_results().expr_ty(recv), clone_trait, &[]) | ||
| { | ||
| sugg(cx, body, expr, recv_path.span, assignval.span); | ||
| } | ||
| } | ||
|
|
||
| fn sugg<'tcx>( | ||
| cx: &LateContext<'tcx>, | ||
| body: &'tcx Expr<'_>, | ||
| expr: &'tcx Expr<'_>, | ||
| slice_span: rustc_span::Span, | ||
| assignval_span: rustc_span::Span, | ||
| ) { | ||
| let mut app = if span_contains_comment(cx.sess().source_map(), body.span) { | ||
| Applicability::MaybeIncorrect // Comments may be informational. | ||
| } else { | ||
| Applicability::MachineApplicable | ||
| }; | ||
|
|
||
| span_lint_and_sugg( | ||
| cx, | ||
| MANUAL_SLICE_FILL, | ||
| expr.span, | ||
| "manually filling a slice", | ||
| "try", | ||
| format!( | ||
| "{}.fill({});", | ||
| snippet_with_applicability(cx, slice_span, "..", &mut app), | ||
| snippet_with_applicability(cx, assignval_span, "..", &mut app), | ||
| ), | ||
| app, | ||
| ); | ||
| } |
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
Oops, something went wrong.