add suppress_lint_in_const conf

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),
     };

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));

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.