1 files changed, 9 insertions, 48 deletions
diff --git a/compiler/rustc_hir_analysis/src/check/intrinsic.rs b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
index ae484b4feda..b43d492eb7a 100644
--- a/compiler/rustc_hir_analysis/src/check/intrinsic.rs
+++ b/compiler/rustc_hir_analysis/src/check/intrinsic.rs
@@ -7,6 +7,7 @@ use crate::errors::{
 };
 use crate::require_same_types;
 
+use hir::def_id::DefId;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
@@ -61,51 +62,10 @@ fn equate_intrinsic_type<'tcx>(
 }
 
 /// Returns the unsafety of the given intrinsic.
-pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety {
-    match intrinsic {
-        // When adding a new intrinsic to this list,
-        // it's usually worth updating that intrinsic's documentation
-        // to note that it's safe to call, since
-        // safe extern fns are otherwise unprecedented.
-        sym::abort
-        | sym::assert_inhabited
-        | sym::assert_zero_valid
-        | sym::assert_uninit_valid
-        | sym::size_of
-        | sym::min_align_of
-        | sym::needs_drop
-        | sym::caller_location
-        | sym::add_with_overflow
-        | sym::sub_with_overflow
-        | sym::mul_with_overflow
-        | sym::wrapping_add
-        | sym::wrapping_sub
-        | sym::wrapping_mul
-        | sym::saturating_add
-        | sym::saturating_sub
-        | sym::rotate_left
-        | sym::rotate_right
-        | sym::ctpop
-        | sym::ctlz
-        | sym::cttz
-        | sym::bswap
-        | sym::bitreverse
-        | sym::discriminant_value
-        | sym::type_id
-        | sym::likely
-        | sym::unlikely
-        | sym::ptr_guaranteed_cmp
-        | sym::minnumf32
-        | sym::minnumf64
-        | sym::maxnumf32
-        | sym::rustc_peek
-        | sym::maxnumf64
-        | sym::type_name
-        | sym::forget
-        | sym::black_box
-        | sym::variant_count
-        | sym::ptr_mask => hir::Unsafety::Normal,
-        _ => hir::Unsafety::Unsafe,
+pub fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: DefId) -> hir::Unsafety {
+    match tcx.has_attr(intrinsic_id, sym::rustc_safe_intrinsic) {
+        true => hir::Unsafety::Normal,
+        false => hir::Unsafety::Unsafe,
     }
 }
 
@@ -113,7 +73,8 @@ pub fn intrinsic_operation_unsafety(intrinsic: Symbol) -> hir::Unsafety {
 /// and in `library/core/src/intrinsics.rs`.
 pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
     let param = |n| tcx.mk_ty_param(n, Symbol::intern(&format!("P{}", n)));
-    let intrinsic_name = tcx.item_name(it.def_id.to_def_id());
+    let intrinsic_id = it.def_id.to_def_id();
+    let intrinsic_name = tcx.item_name(intrinsic_id);
     let name_str = intrinsic_name.as_str();
 
     let bound_vars = tcx.mk_bound_variable_kinds(
@@ -160,7 +121,7 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
         };
         (n_tps, 0, inputs, output, hir::Unsafety::Unsafe)
     } else {
-        let unsafety = intrinsic_operation_unsafety(intrinsic_name);
+        let unsafety = intrinsic_operation_unsafety(tcx, intrinsic_id);
         let (n_tps, inputs, output) = match intrinsic_name {
             sym::abort => (0, Vec::new(), tcx.types.never),
             sym::unreachable => (0, Vec::new(), tcx.types.never),
@@ -351,7 +312,7 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
                 (
                     1,
                     vec![
-                        tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0)),
+                        tcx.mk_imm_ref(tcx.mk_region(ty::ReLateBound(ty::INNERMOST, br)), param(0))
                     ],
                     tcx.mk_projection(discriminant_def_id, tcx.mk_substs([param(0).into()].iter())),
                 )