Auto merge of #125077 - spastorino:add-new-fnsafety-enum2, r=jackh726

Rename Unsafe to Safety

Alternative to #124455, which is to just have one Safety enum to use everywhere, this opens the posibility of adding `ast::Safety::Safe` that's useful for unsafe extern blocks.

This leaves us today with:

```rust
enum ast::Safety {
    Unsafe(Span),
    Default,
    // Safe (going to be added for unsafe extern blocks)
}

enum hir::Safety {
    Unsafe,
    Safe,
}
```

We would convert from `ast::Safety::Default` into the right Safety level according the context.

src/tools/clippy/clippy_lints/src/derive.rs

@@ -5,7 +5,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::{walk_expr, walk_fn, walk_item, FnKind, Visitor};
 use rustc_hir::{
-    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Impl, Item, ItemKind, UnsafeSource, Unsafety,
+    self as hir, BlockCheckMode, BodyId, Expr, ExprKind, FnDecl, Safety, Impl, Item, ItemKind, UnsafeSource,
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::hir::nested_filter;
@@ -415,7 +415,7 @@ impl<'tcx> Visitor<'tcx> for UnsafeVisitor<'_, 'tcx> {
         }
 
         if let Some(header) = kind.header()
-            && header.unsafety == Unsafety::Unsafe
+            && header.safety == Safety::Unsafe
         {
             self.has_unsafe = true;
         }

src/tools/clippy/clippy_lints/src/doc/missing_headers.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint, span_lint_and_note};
 use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
 use clippy_utils::{is_doc_hidden, return_ty};
-use rustc_hir::{BodyId, FnSig, OwnerId, Unsafety};
+use rustc_hir::{BodyId, FnSig, OwnerId, Safety};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::{sym, Span};
@@ -33,14 +33,14 @@ pub fn check(
     }
 
     let span = cx.tcx.def_span(owner_id);
-    match (headers.safety, sig.header.unsafety) {
-        (false, Unsafety::Unsafe) => span_lint(
+    match (headers.safety, sig.header.safety) {
+        (false, Safety::Unsafe) => span_lint(
             cx,
             MISSING_SAFETY_DOC,
             span,
             "unsafe function's docs miss `# Safety` section",
         ),
-        (true, Unsafety::Normal) => span_lint(
+        (true, Safety::Safe) => span_lint(
             cx,
             UNNECESSARY_SAFETY_DOC,
             span,

src/tools/clippy/clippy_lints/src/doc/mod.rs

@@ -12,7 +12,7 @@ use pulldown_cmark::{BrokenLink, CodeBlockKind, CowStr, Options};
 use rustc_ast::ast::Attribute;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{AnonConst, Expr, ImplItemKind, ItemKind, Node, TraitItemKind, Unsafety};
+use rustc_hir::{AnonConst, Expr, ImplItemKind, ItemKind, Node, Safety, TraitItemKind};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::lint::in_external_macro;
@@ -415,13 +415,13 @@ impl<'tcx> LateLintPass<'tcx> for Documentation {
                     }
                 },
                 ItemKind::Trait(_, unsafety, ..) => match (headers.safety, unsafety) {
-                    (false, Unsafety::Unsafe) => span_lint(
+                    (false, Safety::Unsafe) => span_lint(
                         cx,
                         MISSING_SAFETY_DOC,
                         cx.tcx.def_span(item.owner_id),
                         "docs for unsafe trait missing `# Safety` section",
                     ),
-                    (true, Unsafety::Normal) => span_lint(
+                    (true, Safety::Safe) => span_lint(
                         cx,
                         UNNECESSARY_SAFETY_DOC,
                         cx.tcx.def_span(item.owner_id),

src/tools/clippy/clippy_lints/src/eta_reduction.rs

@@ -5,7 +5,7 @@ use clippy_utils::ty::type_diagnostic_name;
 use clippy_utils::usage::{local_used_after_expr, local_used_in};
 use clippy_utils::{get_path_from_caller_to_method_type, is_adjusted, path_to_local, path_to_local_id};
 use rustc_errors::Applicability;
-use rustc_hir::{BindingMode, Expr, ExprKind, FnRetTy, Param, PatKind, QPath, TyKind, Unsafety};
+use rustc_hir::{BindingMode, Expr, ExprKind, FnRetTy, Param, PatKind, QPath, Safety, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{
@@ -146,7 +146,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
                     ty::FnPtr(sig) => sig.skip_binder(),
                     ty::Closure(_, subs) => cx
                         .tcx
-                        .signature_unclosure(subs.as_closure().sig(), Unsafety::Normal)
+                        .signature_unclosure(subs.as_closure().sig(), Safety::Safe)
                         .skip_binder(),
                     _ => {
                         if typeck.type_dependent_def_id(body.value.hir_id).is_some()
@@ -154,7 +154,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
                             && let output = typeck.expr_ty(body.value)
                             && let ty::Tuple(tys) = *subs.type_at(1).kind()
                         {
-                            cx.tcx.mk_fn_sig(tys, output, false, Unsafety::Normal, Abi::Rust)
+                            cx.tcx.mk_fn_sig(tys, output, false, Safety::Safe, Abi::Rust)
                         } else {
                             return;
                         }
@@ -241,11 +241,9 @@ fn check_inputs(
 }
 
 fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure: ClosureArgs<'tcx>, call_sig: FnSig<'_>) -> bool {
-    call_sig.unsafety == Unsafety::Normal
+    call_sig.safety == Safety::Safe
         && !has_late_bound_to_non_late_bound_regions(
-            cx.tcx
-                .signature_unclosure(closure.sig(), Unsafety::Normal)
-                .skip_binder(),
+            cx.tcx.signature_unclosure(closure.sig(), Safety::Safe).skip_binder(),
             call_sig,
         )
 }

src/tools/clippy/clippy_lints/src/functions/misnamed_getters.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, ExprKind, FnDecl, ImplicitSelfKind, Unsafety};
+use rustc_hir::{Body, ExprKind, FnDecl, Safety, ImplicitSelfKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::Span;
@@ -34,7 +34,7 @@ pub fn check_fn(cx: &LateContext<'_>, kind: FnKind<'_>, decl: &FnDecl<'_>, body:
         ImplicitSelfKind::None => return,
     };
 
-    let name = if sig.header.unsafety == Unsafety::Unsafe {
+    let name = if sig.header.safety == Safety::Unsafe {
         name.strip_suffix("_unchecked").unwrap_or(name)
     } else {
         name

src/tools/clippy/clippy_lints/src/functions/not_unsafe_ptr_arg_deref.rs

@@ -19,30 +19,30 @@ pub(super) fn check_fn<'tcx>(
     body: &'tcx hir::Body<'tcx>,
     def_id: LocalDefId,
 ) {
-    let unsafety = match kind {
-        intravisit::FnKind::ItemFn(_, _, hir::FnHeader { unsafety, .. }) => unsafety,
-        intravisit::FnKind::Method(_, sig) => sig.header.unsafety,
+    let safety = match kind {
+        intravisit::FnKind::ItemFn(_, _, hir::FnHeader { safety, .. }) => safety,
+        intravisit::FnKind::Method(_, sig) => sig.header.safety,
         intravisit::FnKind::Closure => return,
     };
 
-    check_raw_ptr(cx, unsafety, decl, body, def_id);
+    check_raw_ptr(cx, safety, decl, body, def_id);
 }
 
 pub(super) fn check_trait_item<'tcx>(cx: &LateContext<'tcx>, item: &'tcx hir::TraitItem<'_>) {
     if let hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(eid)) = item.kind {
         let body = cx.tcx.hir().body(eid);
-        check_raw_ptr(cx, sig.header.unsafety, sig.decl, body, item.owner_id.def_id);
+        check_raw_ptr(cx, sig.header.safety, sig.decl, body, item.owner_id.def_id);
     }
 }
 
 fn check_raw_ptr<'tcx>(
     cx: &LateContext<'tcx>,
-    unsafety: hir::Unsafety,
+    safety: hir::Safety,
     decl: &'tcx hir::FnDecl<'tcx>,
     body: &'tcx hir::Body<'tcx>,
     def_id: LocalDefId,
 ) {
-    if unsafety == hir::Unsafety::Normal && cx.effective_visibilities.is_exported(def_id) {
+    if safety == hir::Safety::Safe && cx.effective_visibilities.is_exported(def_id) {
         let raw_ptrs = iter_input_pats(decl, body)
             .filter_map(|arg| raw_ptr_arg(cx, arg))
             .collect::<HirIdSet>();
@@ -58,7 +58,7 @@ fn check_raw_ptr<'tcx>(
                     },
                     hir::ExprKind::MethodCall(_, recv, args, _) => {
                         let def_id = typeck.type_dependent_def_id(e.hir_id).unwrap();
-                        if cx.tcx.fn_sig(def_id).skip_binder().skip_binder().unsafety == hir::Unsafety::Unsafe {
+                        if cx.tcx.fn_sig(def_id).skip_binder().skip_binder().safety == hir::Safety::Unsafe {
                             check_arg(cx, &raw_ptrs, recv);
                             for arg in args {
                                 check_arg(cx, &raw_ptrs, arg);

src/tools/clippy/clippy_lints/src/inherent_to_string.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::span_lint_and_help;
 use clippy_utils::ty::{implements_trait, is_type_lang_item};
 use clippy_utils::{return_ty, trait_ref_of_method};
-use rustc_hir::{GenericParamKind, ImplItem, ImplItemKind, LangItem, Unsafety};
+use rustc_hir::{GenericParamKind, ImplItem, ImplItemKind, LangItem, Safety};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
@@ -99,7 +99,7 @@ impl<'tcx> LateLintPass<'tcx> for InherentToString {
         if let ImplItemKind::Fn(ref signature, _) = impl_item.kind
             // #11201
             && let header = signature.header
-            && header.unsafety == Unsafety::Normal
+            && header.safety == Safety::Safe
             && header.abi == Abi::Rust
             && impl_item.ident.name == sym::to_string
             && let decl = signature.decl

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

@@ -5038,7 +5038,7 @@ fn lint_binary_expr_with_method_call(cx: &LateContext<'_>, info: &mut BinaryExpr
 }
 
 const FN_HEADER: hir::FnHeader = hir::FnHeader {
-    unsafety: hir::Unsafety::Normal,
+    safety: hir::Safety::Safe,
     constness: hir::Constness::NotConst,
     asyncness: hir::IsAsync::NotAsync,
     abi: rustc_target::spec::abi::Abi::Rust,
@@ -5214,7 +5214,5 @@ impl OutType {
 }
 
 fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool {
-    expected.constness == actual.constness
-        && expected.unsafety == actual.unsafety
-        && expected.asyncness == actual.asyncness
+    expected.constness == actual.constness && expected.safety == actual.safety && expected.asyncness == actual.asyncness
 }

src/tools/clippy/clippy_lints/src/multiple_unsafe_ops_per_block.rs

@@ -2,7 +2,7 @@ use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::visitors::{for_each_expr_with_closures, Descend, Visitable};
 use core::ops::ControlFlow::Continue;
 use hir::def::{DefKind, Res};
-use hir::{BlockCheckMode, ExprKind, QPath, UnOp, Unsafety};
+use hir::{BlockCheckMode, ExprKind, Safety, QPath, UnOp};
 use rustc_ast::Mutability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
@@ -133,7 +133,7 @@ fn collect_unsafe_exprs<'tcx>(
                     ty::FnPtr(sig) => sig,
                     _ => return Continue(Descend::Yes),
                 };
-                if sig.unsafety() == Unsafety::Unsafe {
+                if sig.safety() == Safety::Unsafe {
                     unsafe_ops.push(("unsafe function call occurs here", expr.span));
                 }
             },
@@ -144,7 +144,7 @@ fn collect_unsafe_exprs<'tcx>(
                     .type_dependent_def_id(expr.hir_id)
                     .map(|def_id| cx.tcx.fn_sig(def_id))
                 {
-                    if sig.skip_binder().unsafety() == Unsafety::Unsafe {
+                    if sig.skip_binder().safety() == Safety::Unsafe {
                         unsafe_ops.push(("unsafe method call occurs here", expr.span));
                     }
                 }

src/tools/clippy/clippy_lints/src/new_without_default.rs

@@ -75,7 +75,7 @@ impl<'tcx> LateLintPass<'tcx> for NewWithoutDefault {
                     if let hir::ImplItemKind::Fn(ref sig, _) = impl_item.kind {
                         let name = impl_item.ident.name;
                         let id = impl_item.owner_id;
-                        if sig.header.unsafety == hir::Unsafety::Unsafe {
+                        if sig.header.safety == hir::Safety::Unsafe {
                             // can't be implemented for unsafe new
                             return;
                         }

src/tools/clippy/clippy_lints/src/ptr.rs

@@ -12,7 +12,7 @@ use rustc_hir::hir_id::{HirId, HirIdMap};
 use rustc_hir::intravisit::{walk_expr, Visitor};
 use rustc_hir::{
     self as hir, AnonConst, BinOpKind, BindingMode, Body, Expr, ExprKind, FnRetTy, FnSig, GenericArg, ImplItemKind,
-    ItemKind, Lifetime, Mutability, Node, Param, PatKind, QPath, TraitFn, TraitItem, TraitItemKind, TyKind, Unsafety,
+    ItemKind, Lifetime, Mutability, Node, Param, PatKind, QPath, Safety, TraitFn, TraitItem, TraitItemKind, TyKind,
 };
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::{Obligation, ObligationCause};
@@ -542,7 +542,7 @@ fn check_mut_from_ref<'tcx>(cx: &LateContext<'tcx>, sig: &FnSig<'_>, body: Optio
         if let Some(args) = args
             && !args.is_empty()
             && body.map_or(true, |body| {
-                sig.header.unsafety == Unsafety::Unsafe || contains_unsafe_block(cx, body.value)
+                sig.header.safety == Safety::Unsafe || contains_unsafe_block(cx, body.value)
             })
         {
             span_lint_and_then(

src/tools/clippy/clippy_lints/src/undocumented_unsafe_blocks.rs

@@ -200,7 +200,7 @@ impl<'tcx> LateLintPass<'tcx> for UndocumentedUnsafeBlocks {
         let item_has_safety_comment = item_has_safety_comment(cx, item);
         match (&item.kind, item_has_safety_comment) {
             // lint unsafe impl without safety comment
-            (ItemKind::Impl(impl_), HasSafetyComment::No) if impl_.unsafety == hir::Unsafety::Unsafe => {
+            (ItemKind::Impl(impl_), HasSafetyComment::No) if impl_.safety == hir::Safety::Unsafe => {
                 if !is_lint_allowed(cx, UNDOCUMENTED_UNSAFE_BLOCKS, item.hir_id())
                     && !is_unsafe_from_proc_macro(cx, item.span)
                 {
@@ -222,7 +222,7 @@ impl<'tcx> LateLintPass<'tcx> for UndocumentedUnsafeBlocks {
                 }
             },
             // lint safe impl with unnecessary safety comment
-            (ItemKind::Impl(impl_), HasSafetyComment::Yes(pos)) if impl_.unsafety == hir::Unsafety::Normal => {
+            (ItemKind::Impl(impl_), HasSafetyComment::Yes(pos)) if impl_.safety == hir::Safety::Safe => {
                 if !is_lint_allowed(cx, UNNECESSARY_SAFETY_COMMENT, item.hir_id()) {
                     let (span, help_span) = mk_spans(pos);
 

src/tools/clippy/clippy_utils/src/ast_utils.rs

@@ -386,21 +386,21 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
         (
             Trait(box ast::Trait {
                 is_auto: la,
-                unsafety: lu,
+                safety: lu,
                 generics: lg,
                 bounds: lb,
                 items: li,
             }),
             Trait(box ast::Trait {
                 is_auto: ra,
-                unsafety: ru,
+                safety: ru,
                 generics: rg,
                 bounds: rb,
                 items: ri,
             }),
         ) => {
             la == ra
-                && matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
+                && matches!(lu, Safety::Default) == matches!(ru, Safety::Default)
                 && eq_generics(lg, rg)
                 && over(lb, rb, eq_generic_bound)
                 && over(li, ri, |l, r| eq_item(l, r, eq_assoc_item_kind))
@@ -408,7 +408,7 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
         (TraitAlias(lg, lb), TraitAlias(rg, rb)) => eq_generics(lg, rg) && over(lb, rb, eq_generic_bound),
         (
             Impl(box ast::Impl {
-                unsafety: lu,
+                safety: lu,
                 polarity: lp,
                 defaultness: ld,
                 constness: lc,
@@ -418,7 +418,7 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
                 items: li,
             }),
             Impl(box ast::Impl {
-                unsafety: ru,
+                safety: ru,
                 polarity: rp,
                 defaultness: rd,
                 constness: rc,
@@ -428,7 +428,7 @@ pub fn eq_item_kind(l: &ItemKind, r: &ItemKind) -> bool {
                 items: ri,
             }),
         ) => {
-            matches!(lu, Unsafe::No) == matches!(ru, Unsafe::No)
+            matches!(lu, Safety::Default) == matches!(ru, Safety::Default)
                 && matches!(lp, ImplPolarity::Positive) == matches!(rp, ImplPolarity::Positive)
                 && eq_defaultness(*ld, *rd)
                 && matches!(lc, ast::Const::No) == matches!(rc, ast::Const::No)
@@ -605,7 +605,7 @@ fn eq_opt_coroutine_kind(l: Option<CoroutineKind>, r: Option<CoroutineKind>) ->
 }
 
 pub fn eq_fn_header(l: &FnHeader, r: &FnHeader) -> bool {
-    matches!(l.unsafety, Unsafe::No) == matches!(r.unsafety, Unsafe::No)
+    matches!(l.safety, Safety::Default) == matches!(r.safety, Safety::Default)
         && eq_opt_coroutine_kind(l.coroutine_kind, r.coroutine_kind)
         && matches!(l.constness, Const::No) == matches!(r.constness, Const::No)
         && eq_ext(&l.ext, &r.ext)
@@ -712,7 +712,7 @@ pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
             both(ll, rl, |l, r| eq_id(l.ident, r.ident)) && l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty)
         },
         (BareFn(l), BareFn(r)) => {
-            l.unsafety == r.unsafety
+            l.safety == r.safety
                 && eq_ext(&l.ext, &r.ext)
                 && over(&l.generic_params, &r.generic_params, eq_generic_param)
                 && eq_fn_decl(&l.decl, &r.decl)

src/tools/clippy/clippy_utils/src/check_proc_macro.rs

@@ -18,8 +18,8 @@ use rustc_ast::AttrStyle;
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
     Block, BlockCheckMode, Body, Closure, Destination, Expr, ExprKind, FieldDef, FnHeader, FnRetTy, HirId, Impl,
-    ImplItem, ImplItemKind, IsAuto, Item, ItemKind, LoopSource, MatchSource, MutTy, Node, QPath, TraitItem,
-    TraitItemKind, Ty, TyKind, UnOp, UnsafeSource, Unsafety, Variant, VariantData, YieldSource,
+    ImplItem, ImplItemKind, IsAuto, Item, ItemKind, LoopSource, MatchSource, MutTy, Node, QPath, Safety, TraitItem,
+    TraitItemKind, Ty, TyKind, UnOp, UnsafeSource, Variant, VariantData, YieldSource,
 };
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty::TyCtxt;
@@ -207,10 +207,9 @@ fn item_search_pat(item: &Item<'_>) -> (Pat, Pat) {
         ItemKind::Struct(VariantData::Struct { .. }, _) => (Pat::Str("struct"), Pat::Str("}")),
         ItemKind::Struct(..) => (Pat::Str("struct"), Pat::Str(";")),
         ItemKind::Union(..) => (Pat::Str("union"), Pat::Str("}")),
-        ItemKind::Trait(_, Unsafety::Unsafe, ..)
+        ItemKind::Trait(_, Safety::Unsafe, ..)
         | ItemKind::Impl(Impl {
-            unsafety: Unsafety::Unsafe,
-            ..
+            safety: Safety::Unsafe, ..
         }) => (Pat::Str("unsafe"), Pat::Str("}")),
         ItemKind::Trait(IsAuto::Yes, ..) => (Pat::Str("auto"), Pat::Str("}")),
         ItemKind::Trait(..) => (Pat::Str("trait"), Pat::Str("}")),
@@ -323,7 +322,7 @@ fn ty_search_pat(ty: &Ty<'_>) -> (Pat, Pat) {
         TyKind::Ptr(MutTy { ty, .. }) => (Pat::Str("*"), ty_search_pat(ty).1),
         TyKind::Ref(_, MutTy { ty, .. }) => (Pat::Str("&"), ty_search_pat(ty).1),
         TyKind::BareFn(bare_fn) => (
-            if bare_fn.unsafety == Unsafety::Unsafe {
+            if bare_fn.safety == Safety::Unsafe {
                 Pat::Str("unsafe")
             } else if bare_fn.abi != Abi::Rust {
                 Pat::Str("extern")

src/tools/clippy/clippy_utils/src/hir_utils.rs

@@ -1082,7 +1082,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
                 mut_ty.mutbl.hash(&mut self.s);
             },
             TyKind::BareFn(bfn) => {
-                bfn.unsafety.hash(&mut self.s);
+                bfn.safety.hash(&mut self.s);
                 bfn.abi.hash(&mut self.s);
                 for arg in bfn.decl.inputs {
                     self.hash_ty(arg);

src/tools/clippy/clippy_utils/src/ty.rs

@@ -9,7 +9,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
-use rustc_hir::{Expr, FnDecl, LangItem, TyKind, Unsafety};
+use rustc_hir::{Expr, FnDecl, Safety, LangItem, TyKind};
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::Scalar;
@@ -562,7 +562,7 @@ pub fn peel_mid_ty_refs_is_mutable(ty: Ty<'_>) -> (Ty<'_>, usize, Mutability) {
 /// Returns `true` if the given type is an `unsafe` function.
 pub fn type_is_unsafe_function<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
     match ty.kind() {
-        ty::FnDef(..) | ty::FnPtr(_) => ty.fn_sig(cx.tcx).unsafety() == Unsafety::Unsafe,
+        ty::FnDef(..) | ty::FnPtr(_) => ty.fn_sig(cx.tcx).safety() == Safety::Unsafe,
         _ => false,
     }
 }

src/tools/clippy/clippy_utils/src/visitors.rs

@@ -6,7 +6,7 @@ use rustc_hir::def::{CtorKind, DefKind, Res};
 use rustc_hir::intravisit::{self, walk_block, walk_expr, Visitor};
 use rustc_hir::{
     AnonConst, Arm, Block, BlockCheckMode, Body, BodyId, Expr, ExprKind, HirId, ItemId, ItemKind, LetExpr, Pat, QPath,
-    Stmt, UnOp, UnsafeSource, Unsafety,
+    Safety, Stmt, UnOp, UnsafeSource,
 };
 use rustc_lint::LateContext;
 use rustc_middle::hir::nested_filter;
@@ -421,16 +421,16 @@ pub fn is_expr_unsafe<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
                         .typeck_results()
                         .type_dependent_def_id(e.hir_id)
                         .map_or(false, |id| {
-                            self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe
+                            self.cx.tcx.fn_sig(id).skip_binder().safety() == Safety::Unsafe
                         }) =>
                 {
                     self.is_unsafe = true;
                 },
                 ExprKind::Call(func, _) => match *self.cx.typeck_results().expr_ty(func).peel_refs().kind() {
-                    ty::FnDef(id, _) if self.cx.tcx.fn_sig(id).skip_binder().unsafety() == Unsafety::Unsafe => {
+                    ty::FnDef(id, _) if self.cx.tcx.fn_sig(id).skip_binder().safety() == Safety::Unsafe => {
                         self.is_unsafe = true;
                     },
-                    ty::FnPtr(sig) if sig.unsafety() == Unsafety::Unsafe => self.is_unsafe = true,
+                    ty::FnPtr(sig) if sig.safety() == Safety::Unsafe => self.is_unsafe = true,
                     _ => walk_expr(self, e),
                 },
                 ExprKind::Path(ref p)
@@ -452,7 +452,7 @@ pub fn is_expr_unsafe<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>) -> bool {
         }
         fn visit_nested_item(&mut self, id: ItemId) {
             if let ItemKind::Impl(i) = &self.cx.tcx.hir().item(id).kind {
-                self.is_unsafe = i.unsafety == Unsafety::Unsafe;
+                self.is_unsafe = i.safety == Safety::Unsafe;
             }
         }
     }

src/tools/rustfmt/src/items.rs

@@ -247,7 +247,7 @@ fn allow_single_line_let_else_block(result: &str, block: &ast::Block) -> bool {
 #[allow(dead_code)]
 #[derive(Debug)]
 struct Item<'a> {
-    unsafety: ast::Unsafe,
+    safety: ast::Safety,
     abi: Cow<'static, str>,
     vis: Option<&'a ast::Visibility>,
     body: Vec<BodyElement<'a>>,
@@ -257,7 +257,7 @@ struct Item<'a> {
 impl<'a> Item<'a> {
     fn from_foreign_mod(fm: &'a ast::ForeignMod, span: Span, config: &Config) -> Item<'a> {
         Item {
-            unsafety: fm.unsafety,
+            safety: fm.safety,
             abi: format_extern(
                 ast::Extern::from_abi(fm.abi, DUMMY_SP),
                 config.force_explicit_abi(),
@@ -290,7 +290,7 @@ pub(crate) struct FnSig<'a> {
     coroutine_kind: Cow<'a, Option<ast::CoroutineKind>>,
     constness: ast::Const,
     defaultness: ast::Defaultness,
-    unsafety: ast::Unsafe,
+    safety: ast::Safety,
     visibility: &'a ast::Visibility,
 }
 
@@ -301,7 +301,7 @@ impl<'a> FnSig<'a> {
         visibility: &'a ast::Visibility,
     ) -> FnSig<'a> {
         FnSig {
-            unsafety: method_sig.header.unsafety,
+            safety: method_sig.header.safety,
             coroutine_kind: Cow::Borrowed(&method_sig.header.coroutine_kind),
             constness: method_sig.header.constness,
             defaultness: ast::Defaultness::Final,
@@ -330,7 +330,7 @@ impl<'a> FnSig<'a> {
                 constness: fn_sig.header.constness,
                 coroutine_kind: Cow::Borrowed(&fn_sig.header.coroutine_kind),
                 defaultness,
-                unsafety: fn_sig.header.unsafety,
+                safety: fn_sig.header.safety,
                 visibility: vis,
             },
             _ => unreachable!(),
@@ -345,7 +345,7 @@ impl<'a> FnSig<'a> {
         result.push_str(format_constness(self.constness));
         self.coroutine_kind
             .map(|coroutine_kind| result.push_str(format_coro(&coroutine_kind)));
-        result.push_str(format_unsafety(self.unsafety));
+        result.push_str(format_safety(self.safety));
         result.push_str(&format_extern(
             self.ext,
             context.config.force_explicit_abi(),
@@ -356,7 +356,7 @@ impl<'a> FnSig<'a> {
 
 impl<'a> FmtVisitor<'a> {
     fn format_item(&mut self, item: &Item<'_>) {
-        self.buffer.push_str(format_unsafety(item.unsafety));
+        self.buffer.push_str(format_safety(item.safety));
         self.buffer.push_str(&item.abi);
 
         let snippet = self.snippet(item.span);
@@ -924,7 +924,7 @@ fn format_impl_ref_and_type(
     offset: Indent,
 ) -> Option<String> {
     let ast::Impl {
-        unsafety,
+        safety,
         polarity,
         defaultness,
         constness,
@@ -937,7 +937,7 @@ fn format_impl_ref_and_type(
 
     result.push_str(&format_visibility(context, &item.vis));
     result.push_str(format_defaultness(defaultness));
-    result.push_str(format_unsafety(unsafety));
+    result.push_str(format_safety(safety));
 
     let shape = if context.config.version() == Version::Two {
         Shape::indented(offset + last_line_width(&result), context.config)
@@ -1137,7 +1137,7 @@ pub(crate) fn format_trait(
     };
     let ast::Trait {
         is_auto,
-        unsafety,
+        safety,
         ref generics,
         ref bounds,
         ref items,
@@ -1147,7 +1147,7 @@ pub(crate) fn format_trait(
     let header = format!(
         "{}{}{}trait ",
         format_visibility(context, &item.vis),
-        format_unsafety(unsafety),
+        format_safety(safety),
         format_auto(is_auto),
     );
     result.push_str(&header);

src/tools/rustfmt/src/types.rs

@@ -899,7 +899,7 @@ fn rewrite_bare_fn(
         result.push_str("> ");
     }
 
-    result.push_str(crate::utils::format_unsafety(bare_fn.unsafety));
+    result.push_str(crate::utils::format_safety(bare_fn.safety));
 
     result.push_str(&format_extern(
         bare_fn.ext,

src/tools/rustfmt/src/utils.rs

@@ -108,10 +108,10 @@ pub(crate) fn format_defaultness(defaultness: ast::Defaultness) -> &'static str
 }
 
 #[inline]
-pub(crate) fn format_unsafety(unsafety: ast::Unsafe) -> &'static str {
+pub(crate) fn format_safety(unsafety: ast::Safety) -> &'static str {
     match unsafety {
-        ast::Unsafe::Yes(..) => "unsafe ",
-        ast::Unsafe::No => "",
+        ast::Safety::Unsafe(..) => "unsafe ",
+        ast::Safety::Default => "",
     }
 }
 

src/tools/rustfmt/src/visitor.rs

@@ -24,7 +24,7 @@ use crate::source_map::{LineRangeUtils, SpanUtils};
 use crate::spanned::Spanned;
 use crate::stmt::Stmt;
 use crate::utils::{
-    self, contains_skip, count_newlines, depr_skip_annotation, format_unsafety, inner_attributes,
+    self, contains_skip, count_newlines, depr_skip_annotation, format_safety, inner_attributes,
     last_line_width, mk_sp, ptr_vec_to_ref_vec, rewrite_ident, starts_with_newline, stmt_expr,
 };
 use crate::{ErrorKind, FormatReport, FormattingError};
@@ -517,9 +517,9 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
                     self.visit_enum(item.ident, &item.vis, def, generics, item.span);
                     self.last_pos = source!(self, item.span).hi();
                 }
-                ast::ItemKind::Mod(unsafety, ref mod_kind) => {
+                ast::ItemKind::Mod(safety, ref mod_kind) => {
                     self.format_missing_with_indent(source!(self, item.span).lo());
-                    self.format_mod(mod_kind, unsafety, &item.vis, item.span, item.ident, attrs);
+                    self.format_mod(mod_kind, safety, &item.vis, item.span, item.ident, attrs);
                 }
                 ast::ItemKind::MacCall(ref mac) => {
                     self.visit_mac(mac, Some(item.ident), MacroPosition::Item);
@@ -913,7 +913,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
     fn format_mod(
         &mut self,
         mod_kind: &ast::ModKind,
-        unsafety: ast::Unsafe,
+        safety: ast::Safety,
         vis: &ast::Visibility,
         s: Span,
         ident: symbol::Ident,
@@ -921,7 +921,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
     ) {
         let vis_str = utils::format_visibility(&self.get_context(), vis);
         self.push_str(&*vis_str);
-        self.push_str(format_unsafety(unsafety));
+        self.push_str(format_safety(safety));
         self.push_str("mod ");
         // Calling `to_owned()` to work around borrow checker.
         let ident_str = rewrite_ident(&self.get_context(), ident).to_owned();