X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_passes%2Fsrc%2Fliveness.rs;h=2234837050bd9683750eb05d301c1c29d57aea36;hb=a739fc81539e22591bc43b189c5d6e8c0b1d1a03;hp=0100860afb94f279328a6b8c388466d2f750912d;hpb=3e937d02a012dbce129cc7773517a9bb24f5bf93;p=rust.git

diff --git a/compiler/rustc_passes/src/liveness.rs b/compiler/rustc_passes/src/liveness.rs
index 0100860afb9..2234837050b 100644
--- a/compiler/rustc_passes/src/liveness.rs
+++ b/compiler/rustc_passes/src/liveness.rs
@@ -922,8 +922,7 @@ fn propagate_through_expr(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNod
                 //    v     v
                 //   (  succ  )
                 //
-                let else_ln =
-                    self.propagate_through_opt_expr(else_opt.as_ref().map(|e| &**e), succ);
+                let else_ln = self.propagate_through_opt_expr(else_opt.as_deref(), succ);
                 let then_ln = self.propagate_through_expr(&then, succ);
                 let ln = self.live_node(expr.hir_id, expr.span);
                 self.init_from_succ(ln, else_ln);
@@ -966,7 +965,7 @@ fn propagate_through_expr(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNod
 
             hir::ExprKind::Ret(ref o_e) => {
                 // Ignore succ and subst exit_ln.
-                self.propagate_through_opt_expr(o_e.as_ref().map(|e| &**e), self.exit_ln)
+                self.propagate_through_opt_expr(o_e.as_deref(), self.exit_ln)
             }
 
             hir::ExprKind::Break(label, ref opt_expr) => {
@@ -981,7 +980,7 @@ fn propagate_through_expr(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNod
                 // look it up in the break loop nodes table
 
                 match target {
-                    Some(b) => self.propagate_through_opt_expr(opt_expr.as_ref().map(|e| &**e), b),
+                    Some(b) => self.propagate_through_opt_expr(opt_expr.as_deref(), b),
                     None => span_bug!(expr.span, "`break` to unknown label"),
                 }
             }
@@ -1026,7 +1025,7 @@ fn propagate_through_expr(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNod
             hir::ExprKind::Array(ref exprs) => self.propagate_through_exprs(exprs, succ),
 
             hir::ExprKind::Struct(_, ref fields, ref with_expr) => {
-                let succ = self.propagate_through_opt_expr(with_expr.as_ref().map(|e| &**e), succ);
+                let succ = self.propagate_through_opt_expr(with_expr.as_deref(), succ);
                 fields
                     .iter()
                     .rev()
@@ -1284,20 +1283,19 @@ fn propagate_through_loop(
     fn check_is_ty_uninhabited(&mut self, expr: &Expr<'_>, succ: LiveNode) -> LiveNode {
         let ty = self.typeck_results.expr_ty(expr);
         let m = self.ir.tcx.parent_module(expr.hir_id).to_def_id();
-        if self.ir.tcx.is_ty_uninhabited_from(m, ty, self.param_env) {
-            match self.ir.lnks[succ] {
-                LiveNodeKind::ExprNode(succ_span, succ_id) => {
-                    self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "expression");
-                }
-                LiveNodeKind::VarDefNode(succ_span, succ_id) => {
-                    self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "definition");
-                }
-                _ => {}
-            };
-            self.exit_ln
-        } else {
-            succ
+        if ty.is_inhabited_from(self.ir.tcx, m, self.param_env) {
+            return succ;
         }
+        match self.ir.lnks[succ] {
+            LiveNodeKind::ExprNode(succ_span, succ_id) => {
+                self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "expression");
+            }
+            LiveNodeKind::VarDefNode(succ_span, succ_id) => {
+                self.warn_about_unreachable(expr.span, ty, succ_span, succ_id, "definition");
+            }
+            _ => {}
+        };
+        self.exit_ln
     }
 
     fn warn_about_unreachable(