diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs index d7f2a37c5fe..1f2c7755eee 100644 --- a/clippy_lints/src/indexing_slicing.rs +++ b/clippy_lints/src/indexing_slicing.rs @@ -59,30 +59,30 @@ declare_clippy_lint! { /// ``` declare_clippy_lint! { pub INDEXING_SLICING, - restriction, + pedantic, "indexing/slicing usage" } #[derive(Copy, Clone)] -pub struct IndexingSlicingPass; +pub struct IndexingSlicing; -impl LintPass for IndexingSlicingPass { +impl LintPass for IndexingSlicing { fn get_lints(&self) -> LintArray { lint_array!(INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING) } } -impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicingPass { +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing { fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { - if let ExprIndex(ref a, ref b) = &expr.node { - match &b.node { + if let ExprIndex(ref array, ref index) = &expr.node { + match &index.node { // Both ExprStruct and ExprPath require this approach's checks - // on the `range` returned by `higher::range(cx, b)`. + // on the `range` returned by `higher::range(cx, index)`. // ExprStruct handles &x[n..m], &x[n..] and &x[..n]. // ExprPath handles &x[..] and x[var] - ExprStruct(_, _, _) | ExprPath(_) => { - if let Some(range) = higher::range(cx, b) { - let ty = cx.tables.expr_ty(a); + ExprStruct(..) | ExprPath(..) => { + if let Some(range) = higher::range(cx, index) { + let ty = cx.tables.expr_ty(array); if let ty::TyArray(_, s) = ty.sty { let size: u128 = s.assert_usize(cx.tcx).unwrap().into(); // Index is a constant range. @@ -100,49 +100,48 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicingPass { } } } + + let help_msg; match (range.start, range.end) { (None, Some(_)) => { - cx.span_lint( - INDEXING_SLICING, - expr.span, - "slicing may panic. Consider using \ - `.get(..n)`or `.get_mut(..n)` instead", - ); + help_msg = "Consider using `.get(..n)`or `.get_mut(..n)` instead"; } (Some(_), None) => { - cx.span_lint( - INDEXING_SLICING, - expr.span, - "slicing may panic. Consider using \ - `.get(n..)` or .get_mut(n..)` instead", - ); + help_msg = "Consider using `.get(n..)` or .get_mut(n..)` instead"; } (Some(_), Some(_)) => { - cx.span_lint( - INDEXING_SLICING, - expr.span, - "slicing may panic. Consider using \ - `.get(n..m)` or `.get_mut(n..m)` instead", - ); + help_msg = + "Consider using `.get(n..m)` or `.get_mut(n..m)` instead"; } - (None, None) => (), + (None, None) => return, // [..] is ok } - } else { - cx.span_lint( + + utils::span_help_and_lint( + cx, INDEXING_SLICING, expr.span, - "indexing may panic. Consider using `.get(n)` or \ - `.get_mut(n)` instead", + "slicing may panic.", + help_msg, + ); + } else { + utils::span_help_and_lint( + cx, + INDEXING_SLICING, + expr.span, + "indexing may panic.", + "Consider using `.get(n)` or `.get_mut(n)` instead", ); } } - ExprLit(_) => { + ExprLit(..) => { // [n] - let ty = cx.tables.expr_ty(a); + let ty = cx.tables.expr_ty(array); if let ty::TyArray(_, s) = ty.sty { let size: u128 = s.assert_usize(cx.tcx).unwrap().into(); // Index is a constant uint. - if let Some((Constant::Int(const_index), _)) = constant(cx, cx.tables, b) { + if let Some((Constant::Int(const_index), _)) = + constant(cx, cx.tables, index) + { if size <= const_index { utils::span_lint( cx, @@ -154,11 +153,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicingPass { // Else index is in bounds, ok. } } else { - cx.span_lint( + utils::span_help_and_lint( + cx, INDEXING_SLICING, expr.span, - "indexing may panic. Consider using `.get(n)` or \ - `.get_mut(n)` instead", + "indexing may panic.", + "Consider using `.get(n)` or `.get_mut(n)` instead", ); } } diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index e261fe417f7..621b21429a9 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -431,7 +431,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) { reg.register_late_lint_pass(box unwrap::Pass); reg.register_late_lint_pass(box duration_subsec::DurationSubsec); reg.register_late_lint_pass(box default_trait_access::DefaultTraitAccess); - reg.register_late_lint_pass(box indexing_slicing::IndexingSlicingPass); + reg.register_late_lint_pass(box indexing_slicing::IndexingSlicing); reg.register_lint_group("clippy_restriction", vec![ arithmetic::FLOAT_ARITHMETIC, diff --git a/tests/ui/indexing_slicing.rs b/tests/ui/indexing_slicing.rs index 2437df96bd1..913063b8dd5 100644 --- a/tests/ui/indexing_slicing.rs +++ b/tests/ui/indexing_slicing.rs @@ -21,6 +21,7 @@ fn main() { &x[1..][..5]; &x[0..3]; &x[0..][..3]; + &x[0..].get(..3); // Ok &x[0..=4]; &x[..=4]; &x[..]; diff --git a/tests/ui/indexing_slicing.stderr b/tests/ui/indexing_slicing.stderr index 30231a31d19..642817d9e94 100644 --- a/tests/ui/indexing_slicing.stderr +++ b/tests/ui/indexing_slicing.stderr @@ -1,40 +1,51 @@ -error: indexing may panic. Consider using `.get(n)` or `.get_mut(n)` instead +error: indexing may panic. --> $DIR/indexing_slicing.rs:11:5 | 11 | x[index]; | ^^^^^^^^ | = note: `-D indexing-slicing` implied by `-D warnings` + = help: Consider using `.get(n)` or `.get_mut(n)` instead -error: slicing may panic. Consider using `.get(n..m)` or `.get_mut(n..m)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:12:6 | 12 | &x[index_from..index_to]; | ^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:13:6 | 13 | &x[index_from..][..index_to]; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead -error: slicing may panic. Consider using `.get(n..)` or .get_mut(n..)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:13:6 | 13 | &x[index_from..][..index_to]; | ^^^^^^^^^^^^^^^ + | + = help: Consider using `.get(n..)` or .get_mut(n..)` instead -error: slicing may panic. Consider using `.get(n..)` or .get_mut(n..)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:14:6 | 14 | &x[index..]; | ^^^^^^^^^^ + | + = help: Consider using `.get(n..)` or .get_mut(n..)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:15:6 | 15 | &x[..index]; | ^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: const index is out of bounds --> $DIR/indexing_slicing.rs:18:5 @@ -50,173 +61,211 @@ error: range is out of bounds 20 | &x[1..5]; | ^^^^^^^ -error: slicing may panic. Consider using `.get(n..m)` or `.get_mut(n..m)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:20:6 | 20 | &x[1..5]; | ^^^^^^^ + | + = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:21:6 | 21 | &x[1..][..5]; | ^^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:23:6 | 23 | &x[0..][..3]; | ^^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: range is out of bounds - --> $DIR/indexing_slicing.rs:25:6 + --> $DIR/indexing_slicing.rs:26:6 | -25 | &x[..=4]; +26 | &x[..=4]; | ^^^^^^^ -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead - --> $DIR/indexing_slicing.rs:25:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:26:6 | -25 | &x[..=4]; +26 | &x[..=4]; | ^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: range is out of bounds - --> $DIR/indexing_slicing.rs:29:6 + --> $DIR/indexing_slicing.rs:30:6 | -29 | &x[5..]; +30 | &x[5..]; | ^^^^^^ -error: slicing may panic. Consider using `.get(n..)` or .get_mut(n..)` instead - --> $DIR/indexing_slicing.rs:29:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:30:6 | -29 | &x[5..]; +30 | &x[5..]; | ^^^^^^ + | + = help: Consider using `.get(n..)` or .get_mut(n..)` instead error: range is out of bounds - --> $DIR/indexing_slicing.rs:31:6 + --> $DIR/indexing_slicing.rs:32:6 | -31 | &x[..5]; +32 | &x[..5]; | ^^^^^^ -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead - --> $DIR/indexing_slicing.rs:31:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:32:6 | -31 | &x[..5]; +32 | &x[..5]; | ^^^^^^ - -error: indexing may panic. Consider using `.get(n)` or `.get_mut(n)` instead - --> $DIR/indexing_slicing.rs:34:5 | -34 | y[0]; + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead + +error: indexing may panic. + --> $DIR/indexing_slicing.rs:35:5 + | +35 | y[0]; | ^^^^ - -error: slicing may panic. Consider using `.get(n..m)` or `.get_mut(n..m)` instead - --> $DIR/indexing_slicing.rs:35:6 | -35 | &y[1..2]; - | ^^^^^^^ + = help: Consider using `.get(n)` or `.get_mut(n)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead - --> $DIR/indexing_slicing.rs:38:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:36:6 | -38 | &y[..=4]; +36 | &y[1..2]; | ^^^^^^^ + | + = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead + +error: slicing may panic. + --> $DIR/indexing_slicing.rs:39:6 + | +39 | &y[..=4]; + | ^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: const index is out of bounds - --> $DIR/indexing_slicing.rs:41:5 + --> $DIR/indexing_slicing.rs:42:5 | -41 | empty[0]; +42 | empty[0]; | ^^^^^^^^ error: range is out of bounds - --> $DIR/indexing_slicing.rs:42:6 + --> $DIR/indexing_slicing.rs:43:6 | -42 | &empty[1..5]; +43 | &empty[1..5]; | ^^^^^^^^^^^ -error: slicing may panic. Consider using `.get(n..m)` or `.get_mut(n..m)` instead - --> $DIR/indexing_slicing.rs:42:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:43:6 | -42 | &empty[1..5]; +43 | &empty[1..5]; | ^^^^^^^^^^^ + | + = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead error: range is out of bounds - --> $DIR/indexing_slicing.rs:44:6 + --> $DIR/indexing_slicing.rs:45:6 | -44 | &empty[..=4]; +45 | &empty[..=4]; | ^^^^^^^^^^^ -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead - --> $DIR/indexing_slicing.rs:44:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:45:6 | -44 | &empty[..=4]; +45 | &empty[..=4]; | ^^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: range is out of bounds - --> $DIR/indexing_slicing.rs:49:6 + --> $DIR/indexing_slicing.rs:50:6 | -49 | &empty[..=0]; +50 | &empty[..=0]; | ^^^^^^^^^^^ -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead - --> $DIR/indexing_slicing.rs:49:6 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:50:6 | -49 | &empty[..=0]; +50 | &empty[..=0]; | ^^^^^^^^^^^ - -error: range is out of bounds - --> $DIR/indexing_slicing.rs:51:6 | -51 | &empty[1..]; - | ^^^^^^^^^^ - -error: slicing may panic. Consider using `.get(n..)` or .get_mut(n..)` instead - --> $DIR/indexing_slicing.rs:51:6 - | -51 | &empty[1..]; - | ^^^^^^^^^^ + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: range is out of bounds --> $DIR/indexing_slicing.rs:52:6 | -52 | &empty[..4]; +52 | &empty[1..]; | ^^^^^^^^^^ -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:52:6 | -52 | &empty[..4]; +52 | &empty[1..]; + | ^^^^^^^^^^ + | + = help: Consider using `.get(n..)` or .get_mut(n..)` instead + +error: range is out of bounds + --> $DIR/indexing_slicing.rs:53:6 + | +53 | &empty[..4]; | ^^^^^^^^^^ -error: indexing may panic. Consider using `.get(n)` or `.get_mut(n)` instead - --> $DIR/indexing_slicing.rs:55:5 +error: slicing may panic. + --> $DIR/indexing_slicing.rs:53:6 | -55 | v[0]; - | ^^^^ +53 | &empty[..4]; + | ^^^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead -error: indexing may panic. Consider using `.get(n)` or `.get_mut(n)` instead +error: indexing may panic. --> $DIR/indexing_slicing.rs:56:5 | -56 | v[10]; - | ^^^^^ - -error: slicing may panic. Consider using `.get(n..m)` or `.get_mut(n..m)` instead - --> $DIR/indexing_slicing.rs:57:6 +56 | v[0]; + | ^^^^ | -57 | &v[10..100]; - | ^^^^^^^^^^ + = help: Consider using `.get(n)` or `.get_mut(n)` instead -error: slicing may panic. Consider using `.get(n..)` or .get_mut(n..)` instead +error: indexing may panic. + --> $DIR/indexing_slicing.rs:57:5 + | +57 | v[10]; + | ^^^^^ + | + = help: Consider using `.get(n)` or `.get_mut(n)` instead + +error: slicing may panic. --> $DIR/indexing_slicing.rs:58:6 | -58 | &v[10..]; - | ^^^^^^^ +58 | &v[10..100]; + | ^^^^^^^^^^ + | + = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead -error: slicing may panic. Consider using `.get(..n)`or `.get_mut(..n)` instead +error: slicing may panic. --> $DIR/indexing_slicing.rs:59:6 | -59 | &v[..100]; +59 | &v[10..]; + | ^^^^^^^ + | + = help: Consider using `.get(n..)` or .get_mut(n..)` instead + +error: slicing may panic. + --> $DIR/indexing_slicing.rs:60:6 + | +60 | &v[..100]; | ^^^^^^^^ + | + = help: Consider using `.get(..n)`or `.get_mut(..n)` instead error: aborting due to 36 previous errors