From 96f1385fdd75af35ea888eeb68dc3631d7637a2b Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Mon, 21 Nov 2022 14:36:56 +0800
Subject: [PATCH 1/7] add `suppress_lint_in_const` conf

---
 clippy_lints/src/indexing_slicing.rs | 19 ++++++++++++++++---
 clippy_lints/src/lib.rs              |  3 +++
 clippy_lints/src/utils/conf.rs       |  4 ++++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 4cd7dff4cfd7..23beeb4458c7 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -82,11 +82,24 @@ declare_clippy_lint! {
     "indexing/slicing usage"
 }
 
+#[derive(Copy, Clone)]
+pub struct IndexingSlicing {
+    suppress_lint_in_const: bool,
+}
+
+impl IndexingSlicing {
+    pub fn new(suppress_lint_in_const: bool) -> Self {
+        Self {
+            suppress_lint_in_const,
+        }
+    }
+}
+
 declare_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
 
 impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+        if self.suppress_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id) {
             return;
         }
 
@@ -146,7 +159,7 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                 // Catchall non-range index, i.e., [n] or [n << m]
                 if let ty::Array(..) = ty.kind() {
                     // Index is a const block.
-                    if let ExprKind::ConstBlock(..) = index.kind {
+                    if self.suppress_lint_in_const && let ExprKind::ConstBlock(..) = index.kind {
                         return;
                     }
                     // Index is a constant uint.
@@ -191,7 +204,7 @@ fn to_const_range(cx: &LateContext<'_>, range: higher::Range<'_>, array_size: u1
             } else {
                 Some(x)
             }
-        },
+        }
         Some(_) => None,
         None => Some(array_size),
     };
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 3fe39488ab82..3bac394582e0 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -562,7 +562,9 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     let avoid_breaking_exported_api = conf.avoid_breaking_exported_api;
     let allow_expect_in_tests = conf.allow_expect_in_tests;
     let allow_unwrap_in_tests = conf.allow_unwrap_in_tests;
+    let suppress_lint_in_const = conf.suppress_lint_in_const;
     store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv())));
+    store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv)));
     store.register_late_pass(move |_| {
         Box::new(methods::Methods::new(
             avoid_breaking_exported_api,
@@ -684,6 +686,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd));
     store.register_late_pass(|_| Box::new(unwrap::Unwrap));
     store.register_late_pass(|_| Box::new(indexing_slicing::IndexingSlicing));
+    store.register_late_pass(|_| Box::new(indexing_slicing::IndexingSlicing::new(suppress_lint_in_const)));
     store.register_late_pass(|_| Box::new(non_copy_const::NonCopyConst));
     store.register_late_pass(|_| Box::new(ptr_offset_with_cast::PtrOffsetWithCast));
     store.register_late_pass(|_| Box::new(redundant_clone::RedundantClone));
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index b6dc8cd7ab11..1352632b3a65 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -406,6 +406,10 @@ define_Conf! {
     ///
     /// Whether to allow mixed uninlined format args, e.g. `format!("{} {}", a, foo.bar)`
     (allow_mixed_uninlined_format_args: bool = true),
+    /// Lint: SUPPRESS_LINT
+    ///
+    /// Whether to suppress lint in const function
+    (suppress_lint_in_const: bool = true),
 }
 
 /// Search for the configuration file.

From aed9497978ce0520147cf1cf100513bf049ddf50 Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Tue, 22 Nov 2022 17:12:50 +0800
Subject: [PATCH 2/7] add test and stderr

---
 clippy_lints/src/indexing_slicing.rs              | 12 +++++-------
 clippy_lints/src/lib.rs                           |  3 +--
 clippy_lints/src/utils/conf.rs                    |  2 +-
 tests/ui-toml/suppress_lint_in_const/clippy.toml  |  1 +
 tests/ui-toml/suppress_lint_in_const/test.rs      | 15 +++++++++++++++
 tests/ui-toml/suppress_lint_in_const/test.stderr  | 11 +++++++++++
 .../toml_unknown_key/conf_unknown_key.stderr      |  1 +
 7 files changed, 35 insertions(+), 10 deletions(-)
 create mode 100644 tests/ui-toml/suppress_lint_in_const/clippy.toml
 create mode 100644 tests/ui-toml/suppress_lint_in_const/test.rs
 create mode 100644 tests/ui-toml/suppress_lint_in_const/test.stderr

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 23beeb4458c7..92facbbf0341 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -7,7 +7,7 @@ use rustc_ast::ast::RangeLimits;
 use rustc_hir::{Expr, ExprKind};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty;
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
 
 declare_clippy_lint! {
     /// ### What it does
@@ -82,6 +82,8 @@ declare_clippy_lint! {
     "indexing/slicing usage"
 }
 
+impl_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
+
 #[derive(Copy, Clone)]
 pub struct IndexingSlicing {
     suppress_lint_in_const: bool,
@@ -89,14 +91,10 @@ pub struct IndexingSlicing {
 
 impl IndexingSlicing {
     pub fn new(suppress_lint_in_const: bool) -> Self {
-        Self {
-            suppress_lint_in_const,
-        }
+        Self { suppress_lint_in_const }
     }
 }
 
-declare_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
-
 impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if self.suppress_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id) {
@@ -204,7 +202,7 @@ fn to_const_range(cx: &LateContext<'_>, range: higher::Range<'_>, array_size: u1
             } else {
                 Some(x)
             }
-        }
+        },
         Some(_) => None,
         None => Some(array_size),
     };
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 3bac394582e0..3b5bac644ef5 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -685,8 +685,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(inherent_impl::MultipleInherentImpl));
     store.register_late_pass(|_| Box::new(neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd));
     store.register_late_pass(|_| Box::new(unwrap::Unwrap));
-    store.register_late_pass(|_| Box::new(indexing_slicing::IndexingSlicing));
-    store.register_late_pass(|_| Box::new(indexing_slicing::IndexingSlicing::new(suppress_lint_in_const)));
+    store.register_late_pass(move |_| Box::new(indexing_slicing::IndexingSlicing::new(suppress_lint_in_const)));
     store.register_late_pass(|_| Box::new(non_copy_const::NonCopyConst));
     store.register_late_pass(|_| Box::new(ptr_offset_with_cast::PtrOffsetWithCast));
     store.register_late_pass(|_| Box::new(redundant_clone::RedundantClone));
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 1352632b3a65..4a0e135db835 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -406,7 +406,7 @@ define_Conf! {
     ///
     /// Whether to allow mixed uninlined format args, e.g. `format!("{} {}", a, foo.bar)`
     (allow_mixed_uninlined_format_args: bool = true),
-    /// Lint: SUPPRESS_LINT
+    /// Lint: INDEXING_SLICING
     ///
     /// Whether to suppress lint in const function
     (suppress_lint_in_const: bool = true),
diff --git a/tests/ui-toml/suppress_lint_in_const/clippy.toml b/tests/ui-toml/suppress_lint_in_const/clippy.toml
new file mode 100644
index 000000000000..fd459ff5ac54
--- /dev/null
+++ b/tests/ui-toml/suppress_lint_in_const/clippy.toml
@@ -0,0 +1 @@
+suppress-lint-in-const = false
\ No newline at end of file
diff --git a/tests/ui-toml/suppress_lint_in_const/test.rs b/tests/ui-toml/suppress_lint_in_const/test.rs
new file mode 100644
index 000000000000..e5f4ca7cc902
--- /dev/null
+++ b/tests/ui-toml/suppress_lint_in_const/test.rs
@@ -0,0 +1,15 @@
+#![warn(clippy::indexing_slicing)]
+
+/// An opaque integer representation
+pub struct Integer<'a> {
+    /// The underlying data
+    value: &'a [u8],
+}
+impl<'a> Integer<'a> {
+    // Check whether `self` holds a negative number or not
+    pub const fn is_negative(&self) -> bool {
+        self.value[0] & 0b1000_0000 != 0
+    }
+}
+
+fn main() {}
diff --git a/tests/ui-toml/suppress_lint_in_const/test.stderr b/tests/ui-toml/suppress_lint_in_const/test.stderr
new file mode 100644
index 000000000000..b4f6fe0c024b
--- /dev/null
+++ b/tests/ui-toml/suppress_lint_in_const/test.stderr
@@ -0,0 +1,11 @@
+error: indexing may panic
+  --> $DIR/test.rs:11:9
+   |
+LL |         self.value[0] & 0b1000_0000 != 0
+   |         ^^^^^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+   = note: `-D clippy::indexing-slicing` implied by `-D warnings`
+
+error: aborting due to previous error
+
diff --git a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
index 01a5e962c949..521af13fe03d 100644
--- a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
+++ b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
@@ -35,6 +35,7 @@ error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown fie
            pass-by-value-size-limit
            single-char-binding-names-threshold
            standard-macro-braces
+           suppress-lint-in-const
            third-party
            too-large-for-stack
            too-many-arguments-threshold

From 4528aec7e9a4fdce65a5dfec3a06aad5ee1950dd Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Wed, 23 Nov 2022 16:26:25 +0800
Subject: [PATCH 3/7] update config and suggest

---
 clippy_lints/src/indexing_slicing.rs          | 45 ++++++++++++------
 clippy_lints/src/lib.rs                       |  8 +++-
 clippy_lints/src/utils/conf.rs                |  8 +++-
 .../suppress_lint_in_const/clippy.toml        |  2 +-
 .../suppress_lint_in_const/test.stderr        |  3 +-
 .../toml_unknown_key/conf_unknown_key.stderr  |  2 +-
 tests/ui/indexing_slicing_index.stderr        | 23 +++------
 tests/ui/indexing_slicing_slice.stderr        | 47 +++++--------------
 8 files changed, 63 insertions(+), 75 deletions(-)

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 92facbbf0341..dfea0bf18d10 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -1,9 +1,10 @@
 //! lint on indexing and slicing operations
 
 use clippy_utils::consts::{constant, Constant};
-use clippy_utils::diagnostics::{span_lint, span_lint_and_help};
+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;
@@ -86,18 +87,20 @@ impl_lint_pass!(IndexingSlicing => [INDEXING_SLICING, OUT_OF_BOUNDS_INDEXING]);
 
 #[derive(Copy, Clone)]
 pub struct IndexingSlicing {
-    suppress_lint_in_const: bool,
+    suppress_restriction_lint_in_const: bool,
 }
 
 impl IndexingSlicing {
-    pub fn new(suppress_lint_in_const: bool) -> Self {
-        Self { suppress_lint_in_const }
+    pub fn new(suppress_restriction_lint_in_const: bool) -> Self {
+        Self {
+            suppress_restriction_lint_in_const,
+        }
     }
 }
 
 impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if self.suppress_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+        if self.suppress_restriction_lint_in_const && cx.tcx.hir().is_inside_const_context(expr.hir_id) {
             return;
         }
 
@@ -152,12 +155,19 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                     (None, None) => return, // [..] is ok.
                 };
 
-                span_lint_and_help(cx, INDEXING_SLICING, expr.span, "slicing may panic", None, help_msg);
+                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) {
+                        "the suggestion might not be applicable in constant blocks"
+                    } else {
+                        ""
+                    };
+                    diag.span_suggestion(expr.span, help_msg, note, Applicability::MachineApplicable);
+                });
             } else {
                 // Catchall non-range index, i.e., [n] or [n << m]
                 if let ty::Array(..) = ty.kind() {
                     // Index is a const block.
-                    if self.suppress_lint_in_const && let ExprKind::ConstBlock(..) = index.kind {
+                    if self.suppress_restriction_lint_in_const && let ExprKind::ConstBlock(..) = index.kind {
                         return;
                     }
                     // Index is a constant uint.
@@ -167,14 +177,19 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                     }
                 }
 
-                span_lint_and_help(
-                    cx,
-                    INDEXING_SLICING,
-                    expr.span,
-                    "indexing may panic",
-                    None,
-                    "consider using `.get(n)` or `.get_mut(n)` instead",
-                );
+                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) {
+                        "the suggestion might not be applicable in constant blocks"
+                    } else {
+                        ""
+                    };
+                    diag.span_suggestion(
+                        expr.span,
+                        "consider using `.get(n)` or `.get_mut(n)` instead",
+                        note,
+                        Applicability::MachineApplicable,
+                    );
+                });
             }
         }
     }
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 3b5bac644ef5..2dc3a0822774 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -562,7 +562,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     let avoid_breaking_exported_api = conf.avoid_breaking_exported_api;
     let allow_expect_in_tests = conf.allow_expect_in_tests;
     let allow_unwrap_in_tests = conf.allow_unwrap_in_tests;
-    let suppress_lint_in_const = conf.suppress_lint_in_const;
+    let suppress_restriction_lint_in_const = conf.suppress_restriction_lint_in_const;
     store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv())));
     store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv)));
     store.register_late_pass(move |_| {
@@ -685,7 +685,11 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(inherent_impl::MultipleInherentImpl));
     store.register_late_pass(|_| Box::new(neg_cmp_op_on_partial_ord::NoNegCompOpForPartialOrd));
     store.register_late_pass(|_| Box::new(unwrap::Unwrap));
-    store.register_late_pass(move |_| Box::new(indexing_slicing::IndexingSlicing::new(suppress_lint_in_const)));
+    store.register_late_pass(move |_| {
+        Box::new(indexing_slicing::IndexingSlicing::new(
+            suppress_restriction_lint_in_const,
+        ))
+    });
     store.register_late_pass(|_| Box::new(non_copy_const::NonCopyConst));
     store.register_late_pass(|_| Box::new(ptr_offset_with_cast::PtrOffsetWithCast));
     store.register_late_pass(|_| Box::new(redundant_clone::RedundantClone));
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 4a0e135db835..0022044ea417 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -408,8 +408,12 @@ define_Conf! {
     (allow_mixed_uninlined_format_args: bool = true),
     /// Lint: INDEXING_SLICING
     ///
-    /// Whether to suppress lint in const function
-    (suppress_lint_in_const: bool = true),
+    /// Whether to suppress a restriction lint in constant code. In same
+    /// cases the restructured operation might not be unavoidable, as the
+    /// suggested counterparts are unavailable in constant code. This
+    /// configuration will cause restriction lints to trigger even
+    /// if no suggestion can be made.
+    (suppress_restriction_lint_in_const: bool = true),
 }
 
 /// Search for the configuration file.
diff --git a/tests/ui-toml/suppress_lint_in_const/clippy.toml b/tests/ui-toml/suppress_lint_in_const/clippy.toml
index fd459ff5ac54..d458f53a73dd 100644
--- a/tests/ui-toml/suppress_lint_in_const/clippy.toml
+++ b/tests/ui-toml/suppress_lint_in_const/clippy.toml
@@ -1 +1 @@
-suppress-lint-in-const = false
\ No newline at end of file
+suppress-restriction-lint-in-const = false
\ No newline at end of file
diff --git a/tests/ui-toml/suppress_lint_in_const/test.stderr b/tests/ui-toml/suppress_lint_in_const/test.stderr
index b4f6fe0c024b..4e4583ab33cf 100644
--- a/tests/ui-toml/suppress_lint_in_const/test.stderr
+++ b/tests/ui-toml/suppress_lint_in_const/test.stderr
@@ -2,9 +2,8 @@ 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: `-D clippy::indexing-slicing` implied by `-D warnings`
 
 error: aborting due to previous error
diff --git a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
index 521af13fe03d..6ef2abb15b28 100644
--- a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
+++ b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
@@ -35,7 +35,7 @@ error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown fie
            pass-by-value-size-limit
            single-char-binding-names-threshold
            standard-macro-braces
-           suppress-lint-in-const
+           suppress-restriction-lint-in-const
            third-party
            too-large-for-stack
            too-many-arguments-threshold
diff --git a/tests/ui/indexing_slicing_index.stderr b/tests/ui/indexing_slicing_index.stderr
index d8b6e3f1262b..30fb69907958 100644
--- a/tests/ui/indexing_slicing_index.stderr
+++ b/tests/ui/indexing_slicing_index.stderr
@@ -14,50 +14,39 @@ error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:22:5
    |
 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: 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
diff --git a/tests/ui/indexing_slicing_slice.stderr b/tests/ui/indexing_slicing_slice.stderr
index dc54bd41365d..ac2cc009a22a 100644
--- a/tests/ui/indexing_slicing_slice.stderr
+++ b/tests/ui/indexing_slicing_slice.stderr
@@ -2,50 +2,39 @@ 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
@@ -59,17 +48,13 @@ 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
@@ -87,17 +72,13 @@ 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
@@ -109,17 +90,13 @@ 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
 

From c9bf4b75cea2259ad927228c762d4cf323628ae5 Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Wed, 23 Nov 2022 16:43:42 +0800
Subject: [PATCH 4/7] resolve conflicts

---
 clippy_lints/src/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 2dc3a0822774..5ce70de88104 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -564,7 +564,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     let allow_unwrap_in_tests = conf.allow_unwrap_in_tests;
     let suppress_restriction_lint_in_const = conf.suppress_restriction_lint_in_const;
     store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv())));
-    store.register_late_pass(move |_| Box::new(approx_const::ApproxConstant::new(msrv)));
     store.register_late_pass(move |_| {
         Box::new(methods::Methods::new(
             avoid_breaking_exported_api,

From 1fc98c51dfd771e5cd45c2feee0649ae299ab18b Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Wed, 23 Nov 2022 16:50:05 +0800
Subject: [PATCH 5/7] change default value

---
 clippy_lints/src/utils/conf.rs                   | 2 +-
 tests/ui-toml/suppress_lint_in_const/clippy.toml | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 0022044ea417..f5f0e3ef48cf 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -413,7 +413,7 @@ define_Conf! {
     /// suggested counterparts are unavailable in constant code. This
     /// configuration will cause restriction lints to trigger even
     /// if no suggestion can be made.
-    (suppress_restriction_lint_in_const: bool = true),
+    (suppress_restriction_lint_in_const: bool = false),
 }
 
 /// Search for the configuration file.
diff --git a/tests/ui-toml/suppress_lint_in_const/clippy.toml b/tests/ui-toml/suppress_lint_in_const/clippy.toml
index d458f53a73dd..d6b6fc7f2688 100644
--- a/tests/ui-toml/suppress_lint_in_const/clippy.toml
+++ b/tests/ui-toml/suppress_lint_in_const/clippy.toml
@@ -1 +1 @@
-suppress-restriction-lint-in-const = false
\ No newline at end of file
+suppress-restriction-lint-in-const = false

From 67a94135cbce195078efcbf18ac2347a1d734e68 Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Thu, 24 Nov 2022 09:43:11 +0800
Subject: [PATCH 6/7] change note style

---
 clippy_lints/src/indexing_slicing.rs          | 29 +++----
 .../suppress_lint_in_const/test.stderr        |  4 +-
 tests/ui/indexing_slicing_index.stderr        | 79 +++++++++++++++++--
 tests/ui/indexing_slicing_slice.stderr        | 47 ++++++++---
 4 files changed, 120 insertions(+), 39 deletions(-)

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index dfea0bf18d10..1a8ac43ac894 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -4,7 +4,6 @@ use clippy_utils::consts::{constant, Constant};
 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 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
         }
 
         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 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                 };
 
                 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) {
-                        "the suggestion might not be applicable in constant blocks"
-                    } else {
-                        ""
-                    };
-                    diag.span_suggestion(expr.span, help_msg, note, Applicability::MachineApplicable);
+                    diag.help(help_msg);
+
+                    if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+                        diag.note(note);
+                    }
                 });
             } else {
                 // Catchall non-range index, i.e., [n] or [n << m]
@@ -178,17 +177,11 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                 }
 
                 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) {
-                        "the suggestion might not be applicable in constant blocks"
-                    } else {
-                        ""
-                    };
-                    diag.span_suggestion(
-                        expr.span,
-                        "consider using `.get(n)` or `.get_mut(n)` instead",
-                        note,
-                        Applicability::MachineApplicable,
-                    );
+                    diag.help("consider using `.get(n)` or `.get_mut(n)` instead");
+
+                    if cx.tcx.hir().is_inside_const_context(expr.hir_id) {
+                        diag.note(note);
+                    }
                 });
             }
         }
diff --git a/tests/ui-toml/suppress_lint_in_const/test.stderr b/tests/ui-toml/suppress_lint_in_const/test.stderr
index 4e4583ab33cf..c2acfed559d0 100644
--- a/tests/ui-toml/suppress_lint_in_const/test.stderr
+++ b/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
diff --git a/tests/ui/indexing_slicing_index.stderr b/tests/ui/indexing_slicing_index.stderr
index 30fb69907958..84e1f65623c3 100644
--- a/tests/ui/indexing_slicing_index.stderr
+++ b/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`.
diff --git a/tests/ui/indexing_slicing_slice.stderr b/tests/ui/indexing_slicing_slice.stderr
index ac2cc009a22a..dc54bd41365d 100644
--- a/tests/ui/indexing_slicing_slice.stderr
+++ b/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
 

From eec5039f09bc7992fbacaf0778adf85dcad54997 Mon Sep 17 00:00:00 2001
From: naosense <pingao777@gmail.com>
Date: Mon, 28 Nov 2022 17:40:00 +0800
Subject: [PATCH 7/7] fix test

---
 clippy_lints/src/indexing_slicing.rs          |  2 +-
 .../suppress_lint_in_const/clippy.toml        |  2 +-
 tests/ui-toml/suppress_lint_in_const/test.rs  | 49 ++++++++++++-
 .../suppress_lint_in_const/test.stderr        | 70 +++++++++++++++++--
 tests/ui/indexing_slicing_index.rs            |  6 +-
 tests/ui/indexing_slicing_index.stderr        | 28 ++------
 6 files changed, 122 insertions(+), 35 deletions(-)

diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs
index 1a8ac43ac894..eebfb753a0c5 100644
--- a/clippy_lints/src/indexing_slicing.rs
+++ b/clippy_lints/src/indexing_slicing.rs
@@ -166,7 +166,7 @@ impl<'tcx> LateLintPass<'tcx> for IndexingSlicing {
                 // Catchall non-range index, i.e., [n] or [n << m]
                 if let ty::Array(..) = ty.kind() {
                     // Index is a const block.
-                    if self.suppress_restriction_lint_in_const && let ExprKind::ConstBlock(..) = index.kind {
+                    if let ExprKind::ConstBlock(..) = index.kind {
                         return;
                     }
                     // Index is a constant uint.
diff --git a/tests/ui-toml/suppress_lint_in_const/clippy.toml b/tests/ui-toml/suppress_lint_in_const/clippy.toml
index d6b6fc7f2688..1b9384d7e3ee 100644
--- a/tests/ui-toml/suppress_lint_in_const/clippy.toml
+++ b/tests/ui-toml/suppress_lint_in_const/clippy.toml
@@ -1 +1 @@
-suppress-restriction-lint-in-const = false
+suppress-restriction-lint-in-const = true
diff --git a/tests/ui-toml/suppress_lint_in_const/test.rs b/tests/ui-toml/suppress_lint_in_const/test.rs
index e5f4ca7cc902..5a2df9f6c5d9 100644
--- a/tests/ui-toml/suppress_lint_in_const/test.rs
+++ b/tests/ui-toml/suppress_lint_in_const/test.rs
@@ -1,4 +1,51 @@
+#![feature(inline_const)]
 #![warn(clippy::indexing_slicing)]
+// We also check the out_of_bounds_indexing lint here, because it lints similar things and
+// we want to avoid false positives.
+#![warn(clippy::out_of_bounds_indexing)]
+#![allow(unconditional_panic, clippy::no_effect, clippy::unnecessary_operation)]
+
+const ARR: [i32; 2] = [1, 2];
+const REF: &i32 = &ARR[idx()]; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
+const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
+
+const fn idx() -> usize {
+    1
+}
+const fn idx4() -> usize {
+    4
+}
+
+fn main() {
+    let x = [1, 2, 3, 4];
+    let index: usize = 1;
+    x[index];
+    x[4]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
+    x[1 << 3]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
+
+    x[0]; // Ok, should not produce stderr.
+    x[3]; // Ok, should not produce stderr.
+    x[const { idx() }]; // Ok, should not produce stderr.
+    x[const { idx4() }]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
+    const { &ARR[idx()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
+    const { &ARR[idx4()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
+
+    let y = &x;
+    y[0]; // Ok, referencing shouldn't affect this lint. See the issue 6021
+    y[4]; // Ok, rustc will handle references too.
+
+    let v = vec![0; 5];
+    v[0];
+    v[10];
+    v[1 << 3];
+
+    const N: usize = 15; // Out of bounds
+    const M: usize = 3; // In bounds
+    x[N]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
+    x[M]; // Ok, should not produce stderr.
+    v[N];
+    v[M];
+}
 
 /// An opaque integer representation
 pub struct Integer<'a> {
@@ -11,5 +58,3 @@ impl<'a> Integer<'a> {
         self.value[0] & 0b1000_0000 != 0
     }
 }
-
-fn main() {}
diff --git a/tests/ui-toml/suppress_lint_in_const/test.stderr b/tests/ui-toml/suppress_lint_in_const/test.stderr
index c2acfed559d0..bc178b7e1319 100644
--- a/tests/ui-toml/suppress_lint_in_const/test.stderr
+++ b/tests/ui-toml/suppress_lint_in_const/test.stderr
@@ -1,12 +1,70 @@
-error: indexing may panic
-  --> $DIR/test.rs:11:9
+error[E0080]: evaluation of `main::{constant#3}` failed
+  --> $DIR/test.rs:31:14
    |
-LL |         self.value[0] & 0b1000_0000 != 0
-   |         ^^^^^^^^^^^^^
+LL |     const { &ARR[idx4()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
+   |              ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
+
+note: erroneous constant used
+  --> $DIR/test.rs:31:5
+   |
+LL |     const { &ARR[idx4()] }; // Ok, should not produce stderr, since `suppress-restriction-lint-in-const` is set true.
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+
+error: indexing may panic
+  --> $DIR/test.rs:22:5
+   |
+LL |     x[index];
+   |     ^^^^^^^^
    |
    = 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
+error: indexing may panic
+  --> $DIR/test.rs:38:5
+   |
+LL |     v[0];
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
 
+error: indexing may panic
+  --> $DIR/test.rs:39:5
+   |
+LL |     v[10];
+   |     ^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/test.rs:40:5
+   |
+LL |     v[1 << 3];
+   |     ^^^^^^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/test.rs:46:5
+   |
+LL |     v[N];
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error: indexing may panic
+  --> $DIR/test.rs:47:5
+   |
+LL |     v[M];
+   |     ^^^^
+   |
+   = help: consider using `.get(n)` or `.get_mut(n)` instead
+
+error[E0080]: evaluation of constant value failed
+  --> $DIR/test.rs:10:24
+   |
+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
+
+For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/indexing_slicing_index.rs b/tests/ui/indexing_slicing_index.rs
index 4476e0eb9220..26abc9edb5e4 100644
--- a/tests/ui/indexing_slicing_index.rs
+++ b/tests/ui/indexing_slicing_index.rs
@@ -6,7 +6,7 @@
 #![allow(unconditional_panic, clippy::no_effect, clippy::unnecessary_operation)]
 
 const ARR: [i32; 2] = [1, 2];
-const REF: &i32 = &ARR[idx()]; // Ok, should not produce stderr.
+const REF: &i32 = &ARR[idx()]; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
 const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
 
 const fn idx() -> usize {
@@ -27,8 +27,8 @@ fn main() {
     x[3]; // Ok, should not produce stderr.
     x[const { idx() }]; // Ok, should not produce stderr.
     x[const { idx4() }]; // Ok, let rustc's `unconditional_panic` lint handle `usize` indexing on arrays.
-    const { &ARR[idx()] }; // Ok, should not produce stderr.
-    const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
+    const { &ARR[idx()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
+    const { &ARR[idx4()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
 
     let y = &x;
     y[0]; // Ok, referencing shouldn't affect this lint. See the issue 6021
diff --git a/tests/ui/indexing_slicing_index.stderr b/tests/ui/indexing_slicing_index.stderr
index 84e1f65623c3..8fd77913a3fd 100644
--- a/tests/ui/indexing_slicing_index.stderr
+++ b/tests/ui/indexing_slicing_index.stderr
@@ -1,7 +1,7 @@
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:9:20
    |
-LL | const REF: &i32 = &ARR[idx()]; // Ok, should not produce stderr.
+LL | const REF: &i32 = &ARR[idx()]; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |                    ^^^^^^^^^^
    |
    = help: consider using `.get(n)` or `.get_mut(n)` instead
@@ -20,13 +20,13 @@ LL | const REF_ERR: &i32 = &ARR[idx4()]; // Ok, let rustc handle const contexts.
 error[E0080]: evaluation of `main::{constant#3}` failed
   --> $DIR/indexing_slicing_index.rs:31:14
    |
-LL |     const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
+LL |     const { &ARR[idx4()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |              ^^^^^^^^^^^ index out of bounds: the length is 2 but the index is 4
 
 note: erroneous constant used
   --> $DIR/indexing_slicing_index.rs:31:5
    |
-LL |     const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
+LL |     const { &ARR[idx4()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 error: indexing may panic
@@ -37,26 +37,10 @@ LL |     x[index];
    |
    = 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.
+LL |     const { &ARR[idx()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |              ^^^^^^^^^^
    |
    = help: consider using `.get(n)` or `.get_mut(n)` instead
@@ -65,7 +49,7 @@ LL |     const { &ARR[idx()] }; // Ok, should not produce stderr.
 error: indexing may panic
   --> $DIR/indexing_slicing_index.rs:31:14
    |
-LL |     const { &ARR[idx4()] }; // Ok, let rustc handle const contexts.
+LL |     const { &ARR[idx4()] }; // This should be linted, since `suppress-restriction-lint-in-const` default is false.
    |              ^^^^^^^^^^^
    |
    = help: consider using `.get(n)` or `.get_mut(n)` instead
@@ -117,6 +101,6 @@ 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 14 previous errors
+error: aborting due to 12 previous errors
 
 For more information about this error, try `rustc --explain E0080`.