Auto merge of #85421 - Smittyvb:rm_pushpop_unsafe, r=matthewjasper

Remove some last remants of {push,pop}_unsafe!

These macros have already been removed, but there was still some code handling these macros. That code is now removed.

compiler/rustc_mir_build/src/build/block.rs

@@ -74,8 +74,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         // First we build all the statements in the block.
         let mut let_scope_stack = Vec::with_capacity(8);
         let outer_source_scope = this.source_scope;
-        let outer_push_unsafe_count = this.push_unsafe_count;
-        let outer_unpushed_unsafe = this.unpushed_unsafe;
+        let outer_in_scope_unsafe = this.in_scope_unsafe;
         this.update_source_scope_for_safety_mode(span, safety_mode);
 
         let source_info = this.source_info(span);
@@ -206,8 +205,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         }
         // Restore the original source scope.
         this.source_scope = outer_source_scope;
-        this.push_unsafe_count = outer_push_unsafe_count;
-        this.unpushed_unsafe = outer_unpushed_unsafe;
+        this.in_scope_unsafe = outer_in_scope_unsafe;
         block.unit()
     }
 
@@ -217,8 +215,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         let new_unsafety = match safety_mode {
             BlockSafety::Safe => None,
             BlockSafety::ExplicitUnsafe(hir_id) => {
-                assert_eq!(self.push_unsafe_count, 0);
-                match self.unpushed_unsafe {
+                match self.in_scope_unsafe {
                     Safety::Safe => {}
                     // no longer treat `unsafe fn`s as `unsafe` contexts (see RFC #2585)
                     Safety::FnUnsafe
@@ -226,20 +223,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                             != Level::Allow => {}
                     _ => return,
                 }
-                self.unpushed_unsafe = Safety::ExplicitUnsafe(hir_id);
+                self.in_scope_unsafe = Safety::ExplicitUnsafe(hir_id);
                 Some(Safety::ExplicitUnsafe(hir_id))
             }
-            BlockSafety::PushUnsafe => {
-                self.push_unsafe_count += 1;
-                Some(Safety::BuiltinUnsafe)
-            }
-            BlockSafety::PopUnsafe => {
-                self.push_unsafe_count = self
-                    .push_unsafe_count
-                    .checked_sub(1)
-                    .unwrap_or_else(|| span_bug!(span, "unsafe count underflow"));
-                if self.push_unsafe_count == 0 { Some(self.unpushed_unsafe) } else { None }
-            }
         };
 
         if let Some(unsafety) = new_unsafety {

compiler/rustc_mir_build/src/build/mod.rs

@@ -367,12 +367,8 @@ struct Builder<'a, 'tcx> {
     /// `{ STMTS; EXPR1 } + EXPR2`.
     block_context: BlockContext,
 
-    /// The current unsafe block in scope, even if it is hidden by
-    /// a `PushUnsafeBlock`.
-    unpushed_unsafe: Safety,
-
-    /// The number of `push_unsafe_block` levels in scope.
-    push_unsafe_count: usize,
+    /// The current unsafe block in scope
+    in_scope_unsafe: Safety,
 
     /// The vector of all scopes that we have created thus far;
     /// we track this for debuginfo later.
@@ -877,8 +873,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             source_scopes: IndexVec::new(),
             source_scope: OUTERMOST_SOURCE_SCOPE,
             guard_context: vec![],
-            push_unsafe_count: 0,
-            unpushed_unsafe: safety,
+            in_scope_unsafe: safety,
             local_decls: IndexVec::from_elem_n(LocalDecl::new(return_ty, return_span), 1),
             canonical_user_type_annotations: IndexVec::new(),
             upvar_mutbls: vec![],

compiler/rustc_mir_build/src/thir/cx/block.rs

@@ -27,8 +27,6 @@ impl<'tcx> Cx<'tcx> {
             safety_mode: match block.rules {
                 hir::BlockCheckMode::DefaultBlock => BlockSafety::Safe,
                 hir::BlockCheckMode::UnsafeBlock(..) => BlockSafety::ExplicitUnsafe(block.hir_id),
-                hir::BlockCheckMode::PushUnsafeBlock(..) => BlockSafety::PushUnsafe,
-                hir::BlockCheckMode::PopUnsafeBlock(..) => BlockSafety::PopUnsafe,
             },
         }
     }