Make NonZero a lang item

Author: oli-obk

compiler/rustc_hir/src/lang_items.rs

@@ -428,6 +428,8 @@ language_item_table! {
     String,                  sym::String,              string,                     Target::Struct,         GenericRequirement::None;
     CStr,                    sym::CStr,                c_str,                      Target::Struct,         GenericRequirement::None;
 
+    NonZero,                 sym::NonZero,             non_zero,                   Target::Struct,         GenericRequirement::Exact(1);
+
     // Experimental lang items for implementing contract pre- and post-condition checking.
     ContractBuildCheckEnsures, sym::contract_build_check_ensures, contract_build_check_ensures_fn, Target::Fn, GenericRequirement::None;
     ContractCheckRequires,     sym::contract_check_requires,      contract_check_requires_fn,      Target::Fn, GenericRequirement::None;

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -2581,7 +2581,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => return false,
         };
 
-        if !self.tcx.is_diagnostic_item(sym::NonZero, adt.did()) {
+        if !self.tcx.is_lang_item(adt.did(), LangItem::NonZero) {
             return false;
         }
 

library/core/src/num/nonzero.rs

@@ -123,7 +123,7 @@ impl_zeroable_primitive!(
 #[stable(feature = "generic_nonzero", since = "1.79.0")]
 #[repr(transparent)]
 #[rustc_nonnull_optimization_guaranteed]
-#[rustc_diagnostic_item = "NonZero"]
+#[lang = "NonZero"]
 pub struct NonZero<T: ZeroablePrimitive>(T::NonZeroInner);
 
 macro_rules! impl_nonzero_fmt {

src/tools/clippy/clippy_lints/src/methods/useless_nonzero_new_unchecked.rs

@@ -7,6 +7,7 @@ use rustc_errors::Applicability;
 use rustc_hir::{Block, BlockCheckMode, Expr, ExprKind, Node, QPath, UnsafeSource};
 use rustc_lint::LateContext;
 use rustc_span::sym;
+use rustc_hir::LangItem;
 
 use super::USELESS_NONZERO_NEW_UNCHECKED;
 
@@ -15,7 +16,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, func: &Expr<'
         && segment.ident.name == sym::new_unchecked
         && let [init_arg] = args
         && is_inside_always_const_context(cx.tcx, expr.hir_id)
-        && cx.typeck_results().node_type(ty.hir_id).is_diag_item(cx, sym::NonZero)
+        && cx.typeck_results().node_type(ty.hir_id).is_lang_item(cx, LangItem::NonZero)
         && msrv.meets(cx, msrvs::CONST_UNWRAP)
     {
         let mut app = Applicability::MachineApplicable;

src/tools/clippy/clippy_lints/src/non_zero_suggestions.rs

@@ -3,7 +3,7 @@ use clippy_utils::source::snippet;
 use clippy_utils::sym;
 use rustc_ast::ast::BinOpKind;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind};
+use rustc_hir::{Expr, ExprKind, LangItem};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty};
 use rustc_session::declare_lint_pass;
@@ -81,7 +81,7 @@ fn check_non_zero_conversion(cx: &LateContext<'_>, expr: &Expr<'_>, applicabilit
         // Check if the receiver type is a NonZero type
         if let ty::Adt(adt_def, _) = receiver_ty.kind()
             && adt_def.is_struct()
-            && cx.tcx.get_diagnostic_name(adt_def.did()) == Some(sym::NonZero)
+            && cx.tcx.is_lang_item(adt_def.did(), LangItem::NonZero)
             && let Some(target_non_zero_type) = get_target_non_zero_type(target_ty)
         {
             let arg_snippet = get_arg_snippet(cx, arg, rcv_path);

src/tools/clippy/clippy_lints/src/operators/arithmetic_side_effects.rs

@@ -5,6 +5,7 @@ use clippy_utils::diagnostics::span_lint;
 use clippy_utils::res::MaybeDef;
 use clippy_utils::{expr_or_init, is_from_proc_macro, is_lint_allowed, peel_hir_expr_refs, peel_hir_expr_unary, sym};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::LangItem;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty};
 use rustc_session::impl_lint_pass;
@@ -90,7 +91,7 @@ impl ArithmeticSideEffects {
 
     fn is_non_zero_u(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
         if let ty::Adt(adt, substs) = ty.kind()
-            && cx.tcx.is_diagnostic_item(sym::NonZero, adt.did())
+            && cx.tcx.is_lang_item(adt.did(),LangItem::NonZero)
             && let int_type = substs.type_at(0)
             && matches!(int_type.kind(), ty::Uint(_))
         {

src/tools/clippy/clippy_lints/src/operators/integer_division.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::res::MaybeDef;
 use rustc_hir as hir;
 use rustc_lint::LateContext;
-use rustc_span::symbol::sym;
+use rustc_hir::LangItem;
 
 use super::INTEGER_DIVISION;
 
@@ -16,7 +16,7 @@ pub(crate) fn check<'tcx>(
     if op == hir::BinOpKind::Div
         && cx.typeck_results().expr_ty(left).is_integral()
         && let right_ty = cx.typeck_results().expr_ty(right)
-        && (right_ty.is_integral() || right_ty.is_diag_item(cx, sym::NonZero))
+        && (right_ty.is_integral() || right_ty.is_lang_item(cx, LangItem::NonZero))
     {
         #[expect(clippy::collapsible_span_lint_calls, reason = "rust-clippy#7797")]
         span_lint_and_then(cx, INTEGER_DIVISION, expr.span, "integer division", |diag| {

src/tools/clippy/clippy_lints/src/transmute/transmute_int_to_non_zero.rs

@@ -2,10 +2,11 @@ use super::TRANSMUTE_INT_TO_NON_ZERO;
 use clippy_utils::diagnostics::span_lint_and_sugg;
 use clippy_utils::sugg::Sugg;
 use rustc_errors::Applicability;
-use rustc_hir::Expr;
+use rustc_hir::{Expr};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, Ty};
 use rustc_span::symbol::sym;
+use rustc_hir::LangItem;
 
 /// Checks for `transmute_int_to_non_zero` lint.
 /// Returns `true` if it's triggered, otherwise returns `false`.
@@ -18,7 +19,7 @@ pub(super) fn check<'tcx>(
 ) -> bool {
     if let ty::Int(_) | ty::Uint(_) = from_ty.kind()
         && let ty::Adt(adt, substs) = to_ty.kind()
-        && cx.tcx.is_diagnostic_item(sym::NonZero, adt.did())
+        && cx.tcx.is_lang_item( adt.did(), LangItem::NonZero)
         && let int_ty = substs.type_at(0)
         && from_ty == int_ty
     {