out_of_bounds_indexing improved reporting of out of bounds value

Author: JoshMcguigan

clippy_lints/src/indexing_slicing.rs

@@ -120,7 +120,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
                             utils::span_lint(
                                 cx,
                                 OUT_OF_BOUNDS_INDEXING,
-                                expr.span,
+                                range.start.map_or(expr.span, |start| start.span),
                                 "range is out of bounds",
                             );
                             return;
@@ -132,7 +132,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for IndexingSlicing {
                             utils::span_lint(
                                 cx,
                                 OUT_OF_BOUNDS_INDEXING,
-                                expr.span,
+                                range.end.map_or(expr.span, |end| end.span),
                                 "range is out of bounds",
                             );
                             return;

tests/ui/indexing_slicing.stderr

@@ -48,18 +48,18 @@ error: slicing may panic.
    = help: Consider using `.get(n..)` or .get_mut(n..)` instead
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:30:6
+  --> $DIR/indexing_slicing.rs:30:11
    |
 30 |     &x[..=4];
-   |      ^^^^^^^
+   |           ^
    |
    = note: `-D clippy::out-of-bounds-indexing` implied by `-D warnings`
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:31:6
+  --> $DIR/indexing_slicing.rs:31:11
    |
 31 |     &x[1..5];
-   |      ^^^^^^^
+   |           ^
 
 error: slicing may panic.
   --> $DIR/indexing_slicing.rs:32:6
@@ -70,34 +70,34 @@ error: slicing may panic.
    = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:32:6
+  --> $DIR/indexing_slicing.rs:32:8
    |
 32 |     &x[5..][..10]; // Two lint reports, one for [5..] and another for [..10].
-   |      ^^^^^^
+   |        ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:33:6
+  --> $DIR/indexing_slicing.rs:33:8
    |
 33 |     &x[5..];
-   |      ^^^^^^
+   |        ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:34:6
+  --> $DIR/indexing_slicing.rs:34:10
    |
 34 |     &x[..5];
-   |      ^^^^^^
+   |          ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:35:6
+  --> $DIR/indexing_slicing.rs:35:8
    |
 35 |     &x[5..].iter().map(|x| 2 * x).collect::<Vec<i32>>();
-   |      ^^^^^^
+   |        ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:36:6
+  --> $DIR/indexing_slicing.rs:36:12
    |
 36 |     &x[0..=4];
-   |      ^^^^^^^^
+   |            ^
 
 error: slicing may panic.
   --> $DIR/indexing_slicing.rs:37:6
@@ -148,46 +148,46 @@ error: slicing may panic.
    = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:60:6
+  --> $DIR/indexing_slicing.rs:60:12
    |
 60 |     &empty[1..5];
-   |      ^^^^^^^^^^^
+   |            ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:61:6
+  --> $DIR/indexing_slicing.rs:61:16
    |
 61 |     &empty[0..=4];
-   |      ^^^^^^^^^^^^
+   |                ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:62:6
+  --> $DIR/indexing_slicing.rs:62:15
    |
 62 |     &empty[..=4];
-   |      ^^^^^^^^^^^
+   |               ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:63:6
+  --> $DIR/indexing_slicing.rs:63:12
    |
 63 |     &empty[1..];
-   |      ^^^^^^^^^^
+   |            ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:64:6
+  --> $DIR/indexing_slicing.rs:64:14
    |
 64 |     &empty[..4];
-   |      ^^^^^^^^^^
+   |              ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:65:6
+  --> $DIR/indexing_slicing.rs:65:16
    |
 65 |     &empty[0..=0];
-   |      ^^^^^^^^^^^^
+   |                ^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:66:6
+  --> $DIR/indexing_slicing.rs:66:15
    |
 66 |     &empty[..=0];
-   |      ^^^^^^^^^^^
+   |               ^
 
 error: indexing may panic.
   --> $DIR/indexing_slicing.rs:74:5
@@ -230,10 +230,10 @@ error: slicing may panic.
    = help: Consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:78:6
+  --> $DIR/indexing_slicing.rs:78:8
    |
 78 |     &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
-   |      ^^^^^^^
+   |        ^^
 
 error: slicing may panic.
   --> $DIR/indexing_slicing.rs:79:6
@@ -268,16 +268,16 @@ error: indexing may panic.
    = help: Consider using `.get(n)` or `.get_mut(n)` instead
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:97:6
+  --> $DIR/indexing_slicing.rs:97:13
    |
 97 |     &x[num..10]; // should trigger out of bounds error
-   |      ^^^^^^^^^^
+   |             ^^
 
 error: range is out of bounds
-  --> $DIR/indexing_slicing.rs:98:6
+  --> $DIR/indexing_slicing.rs:98:8
    |
 98 |     &x[10..num]; // should trigger out of bounds error
-   |      ^^^^^^^^^^
+   |        ^^
 
 error: aborting due to 39 previous errors