diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 01f9f45c589..b4e6414195e 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -1,8 +1,9 @@
//! lint on indexing and slicing operations
use crate::consts::{constant, Constant};
+use crate::utils;
+use crate::utils::higher;
use crate::utils::higher::Range;
-use crate::utils::{self, higher};
use rustc::hir::*;
use rustc::lint::*;
use rustc::ty;
@@ -97,89 +98,65 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
if let ExprIndex(ref array, ref index) = &expr.node {
let ty = cx.tables.expr_ty(array);
- match &index.node {
- // Both ExprStruct and ExprPath require this approach's checks
- // 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, index) {
- if let ty::TyArray(_, s) = ty.sty {
- let size: u128 = s.assert_usize(cx.tcx).unwrap().into();
- // Index is a constant range.
- if let Some((start, end)) = to_const_range(cx, range, size) {
- if start > size || end > size {
- utils::span_lint(
- cx,
- OUT_OF_BOUNDS_INDEXING,
- expr.span,
- "range is out of bounds",
- );
- } // Else range is in bounds, ok.
-
- return;
- }
+ if let Some(range) = higher::range(cx, index) {
+ // Ranged indexes, i.e. &x[n..m], &x[n..], &x[..n] and &x[..]
+ if let ty::TyArray(_, s) = ty.sty {
+ let size: u128 = s.assert_usize(cx.tcx).unwrap().into();
+ // Index is a constant range.
+ if let Some((start, end)) = to_const_range(cx, range, size) {
+ if start > size || end > size {
+ utils::span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ expr.span,
+ "range is out of bounds",
+ );
}
-
- let help_msg = match (range.start, range.end) {
- (None, Some(_)) => {
- "Consider using `.get(..n)`or `.get_mut(..n)` instead"
- }
- (Some(_), None) => {
- "Consider using `.get(n..)` or .get_mut(n..)` instead"
- }
- (Some(_), Some(_)) => {
- "Consider using `.get(n..m)` or `.get_mut(n..m)` instead"
- }
- (None, None) => return, // [..] is ok.
- };
-
- utils::span_help_and_lint(
- cx,
- INDEXING_SLICING,
- expr.span,
- "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",
- );
+ return;
}
}
- ExprLit(..) => {
- // [n]
- 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, index)
- {
- if size <= const_index {
- utils::span_lint(
- cx,
- OUT_OF_BOUNDS_INDEXING,
- expr.span,
- "const index is out of bounds",
- );
- }
- // Else index is in bounds, ok.
+
+ let help_msg = match (range.start, range.end) {
+ (None, Some(_)) => "Consider using `.get(..n)`or `.get_mut(..n)` instead",
+ (Some(_), None) => "Consider using `.get(n..)` or .get_mut(n..)` instead",
+ (Some(_), Some(_)) => "Consider using `.get(n..m)` or `.get_mut(n..m)` instead",
+ (None, None) => return, // [..] is ok.
+ };
+
+ utils::span_help_and_lint(
+ cx,
+ INDEXING_SLICING,
+ expr.span,
+ "slicing may panic.",
+ help_msg,
+ );
+ } else {
+ // Catchall non-range index, i.e. [n] or [n << m]
+ 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, index) {
+ if size <= const_index {
+ utils::span_lint(
+ cx,
+ OUT_OF_BOUNDS_INDEXING,
+ expr.span,
+ "const index is out of bounds",
+ );
}
- } else {
- utils::span_help_and_lint(
- cx,
- INDEXING_SLICING,
- expr.span,
- "indexing may panic.",
- "Consider using `.get(n)` or `.get_mut(n)` instead",
- );
+ // Else index is in bounds, ok.
+
+ return;
}
}
- _ => (),
+
+ utils::span_help_and_lint(
+ cx,
+ INDEXING_SLICING,
+ expr.span,
+ "indexing may panic.",
+ "Consider using `.get(n)` or `.get_mut(n)` instead",
+ );
}
}
}
diff --git a/tests/ui/indexing_slicing.rs b/tests/ui/indexing_slicing.rs
index a22c9034346..16174afb106 100644
--- a/tests/ui/indexing_slicing.rs
+++ b/tests/ui/indexing_slicing.rs
@@ -9,55 +9,63 @@ fn main() {
let index_from: usize = 2;
let index_to: usize = 3;
x[index];
- &x[index_from..index_to];
- &x[index_from..][..index_to];
&x[index..];
&x[..index];
- x[0];
- x[3];
+ &x[index_from..index_to];
+ &x[index_from..][..index_to]; // Two lint reports, one for [index_from..] and another for [..index_to].
x[4];
x[1 << 3];
- &x[1..5];
- &x[1..][..5];
- &x[0..3];
- &x[0..][..3];
- &x[0..].get(..3); // Ok
- &x[0..=4];
&x[..=4];
- &x[..];
- &x[1..];
- &x[4..];
+ &x[1..5];
+ &x[5..][..10]; // Two lint reports, one for [5..] and another for [..10].
&x[5..];
- &x[..4];
&x[..5];
&x[5..].iter().map(|x| 2 * x).collect::<Vec<i32>>();
- &x[2..].iter().map(|x| 2 * x).collect::<Vec<i32>>(); // Ok
+ &x[0..=4];
+ &x[0..][..3];
+ &x[1..][..5];
+
+ &x[4..]; // Ok, should not produce stderr.
+ &x[..4]; // Ok, should not produce stderr.
+ &x[..]; // Ok, should not produce stderr.
+ &x[1..]; // Ok, should not produce stderr.
+ &x[2..].iter().map(|x| 2 * x).collect::<Vec<i32>>(); // Ok, should not produce stderr.
+ &x[0..].get(..3); // Ok, should not produce stderr.
+ x[0]; // Ok, should not produce stderr.
+ x[3]; // Ok, should not produce stderr.
+ &x[0..3]; // Ok, should not produce stderr.
let y = &x;
y[0];
&y[1..2];
- &y[..];
&y[0..=4];
&y[..=4];
+ &y[..]; // Ok, should not produce stderr.
+
let empty: [i8; 0] = [];
empty[0];
&empty[1..5];
&empty[0..=4];
&empty[..=4];
- &empty[..];
- &empty[0..];
- &empty[0..0];
- &empty[0..=0];
- &empty[..=0];
- &empty[..0];
&empty[1..];
&empty[..4];
+ &empty[0..=0];
+ &empty[..=0];
+
+ &empty[0..]; // Ok, should not produce stderr.
+ &empty[0..0]; // Ok, should not produce stderr.
+ &empty[..0]; // Ok, should not produce stderr.
+ &empty[..]; // Ok, should not produce stderr.
let v = vec![0; 5];
v[0];
v[10];
+ v[1 << 3];
&v[10..100];
+ &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
&v[10..];
&v[..100];
+
+ &v[..]; // Ok, should not produce stderr.
}
diff --git a/tests/ui/indexing_slicing.stderr b/tests/ui/indexing_slicing.stderr
index 605a96e8b8c..c9aefe0349a 100644
--- a/tests/ui/indexing_slicing.stderr
+++ b/tests/ui/indexing_slicing.stderr
@@ -10,109 +10,135 @@ error: indexing may panic.
error: slicing may panic.
--> $DIR/indexing_slicing.rs:12:6
|
-12 | &x[index_from..index_to];
+12 | &x[index..];
+ | ^^^^^^^^^^
+ |
+ = help: Consider using `.get(n..)` or .get_mut(n..)` instead
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:13:6
+ |
+13 | &x[..index];
+ | ^^^^^^^^^^
+ |
+ = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:14:6
+ |
+14 | &x[index_from..index_to];
| ^^^^^^^^^^^^^^^^^^^^^^^
|
= help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:13:6
+ --> $DIR/indexing_slicing.rs:15:6
|
-13 | &x[index_from..][..index_to];
+15 | &x[index_from..][..index_to]; // Two lint reports, one for [index_from..] and another for [..index_to].
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: Consider using `.get(..n)`or `.get_mut(..n)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:13:6
+ --> $DIR/indexing_slicing.rs:15:6
|
-13 | &x[index_from..][..index_to];
+15 | &x[index_from..][..index_to]; // Two lint reports, one for [index_from..] and another for [..index_to].
| ^^^^^^^^^^^^^^^
|
= help: 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.
- --> $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
+ --> $DIR/indexing_slicing.rs:16:5
|
-18 | x[4];
+16 | x[4];
| ^^^^
|
= note: `-D out-of-bounds-indexing` implied by `-D warnings`
+error: const index is out of bounds
+ --> $DIR/indexing_slicing.rs:17:5
+ |
+17 | x[1 << 3];
+ | ^^^^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:18:6
+ |
+18 | &x[..=4];
+ | ^^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:19:6
+ |
+19 | &x[1..5];
+ | ^^^^^^^
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:20:6
+ |
+20 | &x[5..][..10]; // Two lint reports, one for [5..] and another for [..10].
+ | ^^^^^^^^^^^^
+ |
+ = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
+
error: range is out of bounds
--> $DIR/indexing_slicing.rs:20:6
|
-20 | &x[1..5];
- | ^^^^^^^
+20 | &x[5..][..10]; // Two lint reports, one for [5..] and another for [..10].
+ | ^^^^^^
-error: slicing may panic.
+error: range is out of bounds
--> $DIR/indexing_slicing.rs:21:6
|
-21 | &x[1..][..5];
+21 | &x[5..];
+ | ^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:22:6
+ |
+22 | &x[..5];
+ | ^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:23:6
+ |
+23 | &x[5..].iter().map(|x| 2 * x).collect::<Vec<i32>>();
+ | ^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:24:6
+ |
+24 | &x[0..=4];
+ | ^^^^^^^^
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:25:6
+ |
+25 | &x[0..][..3];
| ^^^^^^^^^^^
|
= help: Consider using `.get(..n)`or `.get_mut(..n)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:23:6
+ --> $DIR/indexing_slicing.rs:26:6
|
-23 | &x[0..][..3];
+26 | &x[1..][..5];
| ^^^^^^^^^^^
|
= help: Consider using `.get(..n)`or `.get_mut(..n)` instead
-error: range is out of bounds
- --> $DIR/indexing_slicing.rs:26:6
- |
-26 | &x[..=4];
- | ^^^^^^^
-
-error: range is out of bounds
- --> $DIR/indexing_slicing.rs:30:6
- |
-30 | &x[5..];
- | ^^^^^^
-
-error: range is out of bounds
- --> $DIR/indexing_slicing.rs:32:6
- |
-32 | &x[..5];
- | ^^^^^^
-
-error: range is out of bounds
- --> $DIR/indexing_slicing.rs:33:6
- |
-33 | &x[5..].iter().map(|x| 2 * x).collect::<Vec<i32>>();
- | ^^^^^^
-
error: indexing may panic.
- --> $DIR/indexing_slicing.rs:37:5
+ --> $DIR/indexing_slicing.rs:39:5
|
-37 | y[0];
+39 | y[0];
| ^^^^
|
= help: Consider using `.get(n)` or `.get_mut(n)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:38:6
+ --> $DIR/indexing_slicing.rs:40:6
|
-38 | &y[1..2];
+40 | &y[1..2];
| ^^^^^^^
|
= help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead
@@ -120,86 +146,128 @@ error: slicing may panic.
error: slicing may panic.
--> $DIR/indexing_slicing.rs:41:6
|
-41 | &y[..=4];
+41 | &y[0..=4];
+ | ^^^^^^^^
+ |
+ = help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:42:6
+ |
+42 | &y[..=4];
| ^^^^^^^
|
= help: Consider using `.get(..n)`or `.get_mut(..n)` instead
error: const index is out of bounds
- --> $DIR/indexing_slicing.rs:44:5
+ --> $DIR/indexing_slicing.rs:47:5
|
-44 | empty[0];
+47 | empty[0];
| ^^^^^^^^
error: range is out of bounds
- --> $DIR/indexing_slicing.rs:45:6
+ --> $DIR/indexing_slicing.rs:48:6
|
-45 | &empty[1..5];
+48 | &empty[1..5];
| ^^^^^^^^^^^
error: range is out of bounds
- --> $DIR/indexing_slicing.rs:47:6
+ --> $DIR/indexing_slicing.rs:49:6
|
-47 | &empty[..=4];
+49 | &empty[0..=4];
+ | ^^^^^^^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:50:6
+ |
+50 | &empty[..=4];
| ^^^^^^^^^^^
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:51:6
+ |
+51 | &empty[1..];
+ | ^^^^^^^^^^
+
error: range is out of bounds
--> $DIR/indexing_slicing.rs:52:6
|
-52 | &empty[..=0];
- | ^^^^^^^^^^^
+52 | &empty[..4];
+ | ^^^^^^^^^^
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:53:6
+ |
+53 | &empty[0..=0];
+ | ^^^^^^^^^^^^
error: range is out of bounds
--> $DIR/indexing_slicing.rs:54:6
|
-54 | &empty[1..];
- | ^^^^^^^^^^
-
-error: range is out of bounds
- --> $DIR/indexing_slicing.rs:55:6
- |
-55 | &empty[..4];
- | ^^^^^^^^^^
+54 | &empty[..=0];
+ | ^^^^^^^^^^^
error: indexing may panic.
- --> $DIR/indexing_slicing.rs:58:5
+ --> $DIR/indexing_slicing.rs:62:5
|
-58 | v[0];
+62 | v[0];
| ^^^^
|
= help: Consider using `.get(n)` or `.get_mut(n)` instead
error: indexing may panic.
- --> $DIR/indexing_slicing.rs:59:5
+ --> $DIR/indexing_slicing.rs:63:5
|
-59 | v[10];
+63 | v[10];
| ^^^^^
|
= help: Consider using `.get(n)` or `.get_mut(n)` instead
-error: slicing may panic.
- --> $DIR/indexing_slicing.rs:60:6
+error: indexing may panic.
+ --> $DIR/indexing_slicing.rs:64:5
|
-60 | &v[10..100];
+64 | v[1 << 3];
+ | ^^^^^^^^^
+ |
+ = help: Consider using `.get(n)` or `.get_mut(n)` instead
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:65:6
+ |
+65 | &v[10..100];
| ^^^^^^^^^^
|
= help: Consider using `.get(n..m)` or `.get_mut(n..m)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:61:6
+ --> $DIR/indexing_slicing.rs:66:6
|
-61 | &v[10..];
+66 | &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
+ | ^^^^^^^^^^^^^^
+ |
+ = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
+
+error: range is out of bounds
+ --> $DIR/indexing_slicing.rs:66:6
+ |
+66 | &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
+ | ^^^^^^^
+
+error: slicing may panic.
+ --> $DIR/indexing_slicing.rs:67:6
+ |
+67 | &v[10..];
| ^^^^^^^
|
= help: Consider using `.get(n..)` or .get_mut(n..)` instead
error: slicing may panic.
- --> $DIR/indexing_slicing.rs:62:6
+ --> $DIR/indexing_slicing.rs:68:6
|
-62 | &v[..100];
+68 | &v[..100];
| ^^^^^^^^
|
= help: Consider using `.get(..n)`or `.get_mut(..n)` instead
-error: aborting due to 28 previous errors
+error: aborting due to 38 previous errors