From 9c5081f4818c2b0bcb55810949726107ea1650d1 Mon Sep 17 00:00:00 2001
From: Ben Kimock <kimockb@gmail.com>
Date: Tue, 6 Jun 2023 21:25:42 -0400
Subject: [PATCH] Make function bodies with &! arguments unreachable
---
compiler/rustc_codegen_ssa/src/mir/mod.rs | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index a6fcf1fd38c1f..73a7db5097c22 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -209,6 +209,19 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
caller_location: None,
};
+ if mir.args_iter().any(|arg| {
+ // Find the monomorphized type of our argument
+ let arg_decl = &mir.local_decls[arg];
+ let arg_ty = fx.monomorphize(arg_decl.ty);
+
+ // And check if it is a reference to an uninhabited type
+ let ty = arg_ty.peel_refs();
+ start_bx.layout_of(ty).abi.is_uninhabited()
+ }) {
+ start_bx.unreachable();
+ return;
+ }
+
// It may seem like we should iterate over `required_consts` to ensure they all successfully
// evaluate; however, the `MirUsedCollector` already did that during the collection phase of
// monomorphization so we don't have to do it again.