From 1d7623bb1f14a0886a60a6921fbc3cedb2b9581c Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Fri, 10 Dec 2021 15:19:59 -0800
Subject: [PATCH] Enable u128 codepath for Emscripten targets on rust 1.40+

---
 build.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/build.rs b/build.rs
index f48477a..64cac93 100644
--- a/build.rs
+++ b/build.rs
@@ -14,9 +14,10 @@ fn main() {
     let target = env::var("TARGET").unwrap();
     let emscripten = target == "asmjs-unknown-emscripten" || target == "wasm32-unknown-emscripten";
 
-    // 128-bit integers disabled on Emscripten targets as Emscripten doesn't
-    // currently support integers larger than 64 bits.
-    if !emscripten {
+    // 128-bit integers Disabled on Emscripten targets before Rust 1.40 since
+    // Emscripten did not support 128-bit integers until Rust 1.40
+    // (https://github.com/rust-lang/rust/pull/65251)
+    if !emscripten || minor >= 40 {
         println!("cargo:rustc-cfg=integer128");
     }