change note style

clippy_lints/src/indexing_slicing.rs

@@ -4,7 +4,6 @@
 use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
 use clippy_utils::higher;
 use rustc_ast::ast::RangeLimits;
-use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
@@ -105,6 +104,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         }
 
         if let ExprKind::Index(array, index) = &expr.kind {
+            let note = "the suggestion might not be applicable in constant blocks";
             let ty = cx.typeck_results().expr_ty(array).peel_refs();
             if let Some(range) = higher::Range::hir(index) {
                 // Ranged indexes, i.e., &x[n..m], &x[n..], &x[..n] and &x[..]
@@ -156,12 +156,11 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
                 };
 
                 span_lint_and_then(cx, INDEXING_SLICING, expr.span, "slicing may panic", |diag| {
-                    let note = if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+                    diag.help(help_msg);
-                        "the suggestion might not be applicable in constant blocks"
+
-                    } else {
+                    if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
-                        ""
+                        diag.note(note);
-                    };
+                    }
-                    diag.span_suggestion(expr.span, help_msg, note, Applicability::MachineApplicable);
                 });
             } else {
                 // Catchall non-range index, i.e., [n] or [n << m]
@@ -178,17 +177,11 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
                 }
 
                 span_lint_and_then(cx, INDEXING_SLICING, expr.span, "indexing may panic", |diag| {
-                    let note = if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+                    diag.help("consider using `.get(n)` or `.get_mut(n)` instead");
-                        "the suggestion might not be applicable in constant blocks"
+
-                    } else {
+                    if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
-                        ""
+                        diag.note(note);
-                    };
+                    }
-                    diag.span_suggestion(
-                        expr.span,
-                        "consider using `.get(n)` or `.get_mut(n)` instead",
-                        note,
-                        Applicability::MachineApplicable,
-                    );
                 });
             }
         }

tests/ui-toml/suppress_lint_in_const/test.stderr

@@ -2,8 +2,10 @@ error: indexing may panic
   --> $DIR/test.rs:11:9
    |
 LL |         self.value[0] & 0b1000_0000 != 0
-   |         ^^^^^^^^^^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead: `the suggestion might not be applicable in constant blocks`
+   |         ^^^^^^^^^^^^^
    |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: the suggestion might not be applicable in constant blocks
    = note: `-D clippy::indexing-slicing` implied by `-D warnings`
 
 error: aborting due to previous error

tests/ui/indexing_slicing_index.stderr

@@ -1,3 +1,22 @@
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:9:20
+   |
+LL | const REF: &i32 = &ARR[idx()]; // Ok, should not produce stderr.
+   |                    ^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: the suggestion might not be applicable in constant blocks
+   = note: `-D clippy::indexing-slicing` implied by `-D warnings`
+
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:10:24
+   |
+LL | const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
+   |                        ^^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: the suggestion might not be applicable in constant blocks
+
 error[E0080]: evaluation of `main::{constant#3}` failed
   --> $DIR/indexing_slicing_index.rs:31:14
    |
@@ -14,39 +33,83 @@ error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:22:5
    |
 LL |     x[index];
-   |     ^^^^^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^^^^^
    |
-   = note: `-D clippy::indexing-slicing` implied by `-D warnings`
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:28:5
+   |
+LL |     x[const { idx() }]; // Ok, should not produce stderr.
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:29:5
+   |
+LL |     x[const { idx4() }]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:30:14
+   |
+LL |     const { &ARR[idx()] }; // Ok, should not produce stderr.
+   |              ^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: the suggestion might not be applicable in constant blocks
+
+error: indexing may panic
+  --> $DIR/indexing_slicing_index.rs:31:14
+   |
+LL |     const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
+   |              ^^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: the suggestion might not be applicable in constant blocks
 
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:38:5
    |
 LL |     v[0];
-   |     ^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:39:5
    |
 LL |     v[10];
-   |     ^^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:40:5
    |
 LL |     v[1 << 3];
-   |     ^^^^^^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:46:5
    |
 LL |     v[N];
-   |     ^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:47:5
    |
 LL |     v[M];
-   |     ^^^^ help: consider using `.get(n)` or `.get_mut(n)` instead
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
 error[E0080]: evaluation of constant value failed
   --> $DIR/indexing_slicing_index.rs:10:24
@@ -54,6 +117,6 @@ error[E0080]: evaluation of constant value failed
 LL | const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
    |                        ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
 
-error: aborting due to 8 previous errors
+error: aborting due to 14 previous errors
 
 For more information about this error, try `rustc --explain E0080`.

tests/ui/indexing_slicing_slice.stderr

@@ -2,39 +2,50 @@ error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:12:6
    |
 LL |     &x[index..];
-   |      ^^^^^^^^^^ help: consider using `.get(n..)` or .get_mut(n..)` instead
+   |      ^^^^^^^^^^
    |
+   = help: consider using `.get(n..)` or .get_mut(n..)` instead
    = note: `-D clippy::indexing-slicing` implied by `-D warnings`
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:13:6
    |
 LL |     &x[..index];
-   |      ^^^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:14:6
    |
 LL |     &x[index_from..index_to];
-   |      ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
+   |      ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:15:6
    |
 LL |     &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
+   |      ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:15:6
    |
 LL |     &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
+   |      ^^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(n..)` or .get_mut(n..)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:16:6
    |
 LL |     &x[5..][..10]; // Two lint reports, one for out of bounds [5..] and another for slicing [..10].
-   |      ^^^^^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
   --> $DIR/indexing_slicing_slice.rs:16:8
@@ -48,13 +59,17 @@ error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:17:6
    |
 LL |     &x[0..][..3];
-   |      ^^^^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:18:6
    |
 LL |     &x[1..][..5];
-   |      ^^^^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
   --> $DIR/indexing_slicing_slice.rs:25:12
@@ -72,13 +87,17 @@ error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:31:6
    |
 LL |     &v[10..100];
-   |      ^^^^^^^^^^ help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
+   |      ^^^^^^^^^^
+   |
+   = help: consider using `.get(n..m)` or `.get_mut(n..m)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:32:6
    |
 LL |     &x[10..][..100]; // Two lint reports, one for [10..] and another for [..100].
-   |      ^^^^^^^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: range is out of bounds
   --> $DIR/indexing_slicing_slice.rs:32:8
@@ -90,13 +109,17 @@ error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:33:6
    |
 LL |     &v[10..];
-   |      ^^^^^^^ help: consider using `.get(n..)` or .get_mut(n..)` instead
+   |      ^^^^^^^
+   |
+   = help: consider using `.get(n..)` or .get_mut(n..)` instead
 
 error: slicing may panic
   --> $DIR/indexing_slicing_slice.rs:34:6
    |
 LL |     &v[..100];
-   |      ^^^^^^^^ help: consider using `.get(..n)`or `.get_mut(..n)` instead
+   |      ^^^^^^^^
+   |
+   = help: consider using `.get(..n)`or `.get_mut(..n)` instead
 
 error: aborting due to 16 previous errors