From 878356f7acd4ea123a62ed6014147e48080bc69c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20K=C3=A5re=20Alsaker?= <john.kare.alsaker@gmail.com>
Date: Thu, 3 May 2018 05:16:39 +0200
Subject: [PATCH] Add assertions for TyS and TypeVariants sizes

---
 src/librustc/ty/context.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index bce1776d388ee..e023da06bdef4 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -794,6 +794,12 @@ impl<'a, 'gcx> HashStable<StableHashingContext<'a>> for TypeckTables<'gcx> {
 
 impl<'tcx> CommonTypes<'tcx> {
     fn new(interners: &CtxtInterners<'tcx>) -> CommonTypes<'tcx> {
+        // Ensure our type representation does not grow
+        #[cfg(target_pointer_width = "64")]
+        assert!(mem::size_of::<ty::TypeVariants>() <= 24);
+        #[cfg(target_pointer_width = "64")]
+        assert!(mem::size_of::<ty::TyS>() <= 32);
+
         let mk = |sty| CtxtInterners::intern_ty(interners, interners, sty);
         let mk_region = |r| {
             if let Some(r) = interners.region.borrow().get(&r) {