From: Ralf Jung <post@ralfj.de>
Date: Thu, 5 Dec 2019 13:20:53 +0000 (+0100)
Subject: codegen: mark invalid SetDiscriminant unreachable
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=8655ad5936dda66a9123251c4c3fa43b7e5b80a4;p=rust.git

codegen: mark invalid SetDiscriminant unreachable
---

diff --git a/src/librustc_codegen_ssa/mir/place.rs b/src/librustc_codegen_ssa/mir/place.rs
index e2507394ce6..4b8819d11f4 100644
--- a/src/librustc_codegen_ssa/mir/place.rs
+++ b/src/librustc_codegen_ssa/mir/place.rs
@@ -333,6 +333,7 @@ pub fn codegen_set_discr<Bx: BuilderMethods<'a, 'tcx, Value = V>>(
         variant_index: VariantIdx
     ) {
         if self.layout.for_variant(bx.cx(), variant_index).abi.is_uninhabited() {
+            bx.unreachable();
             return;
         }
         match self.layout.variants {
@@ -488,9 +489,9 @@ pub fn codegen_place(
                     },
                     Err(_) => {
                         // This is unreachable as long as runtime
-                        // and compile-time agree on values
+                        // and compile-time agree perfectly.
                         // With floats that won't always be true,
-                        // so we generate an abort.
+                        // so we generate a (safe) abort.
                         bx.abort();
                         let llval = bx.cx().const_undef(
                             bx.cx().type_ptr_to(bx.cx().backend_type(layout))