From a806c53b2cfb1d17c6825691cf1f1a5731755df3 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Tue, 2 Apr 2019 07:46:06 -0700
Subject: [PATCH] Don't compile math symbols on wasm32-unknown-wasi

These are already provided by the C sysroot, so no need for us to
duplicate them!
---
 library/compiler-builtins/src/math.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/library/compiler-builtins/src/math.rs b/library/compiler-builtins/src/math.rs
index 18def0e86c70..dfdd99cdf931 100644
--- a/library/compiler-builtins/src/math.rs
+++ b/library/compiler-builtins/src/math.rs
@@ -14,9 +14,14 @@ macro_rules! no_mangle {
     }
 }
 
-// only for the wasm32-unknown-unknown target
-#[cfg(any(all(target_arch = "wasm32", target_os = "unknown"),
-          all(target_vendor = "fortanix", target_env = "sgx")))]
+#[cfg(any(
+    all(
+        target_arch = "wasm32",
+        target_os = "unknown",
+        not(target_env = "wasi")
+    ),
+    all(target_vendor = "fortanix", target_env = "sgx")
+))]
 no_mangle! {
     fn acos(x: f64) -> f64;
     fn asin(x: f64) -> f64;