From 6e3b5052186447104e28fe746ef291141cdece41 Mon Sep 17 00:00:00 2001
From: roblabla <unfiltered@roblab.la>
Date: Thu, 31 Mar 2022 12:58:26 +0200
Subject: [PATCH] Fix clang-cl treating file as a /U arg.

On MacOS, paths will likely start with /Users, but clang-cl treats /U
as an argument, which leads to the source being mistaken for a flag. To
avoid this, we can pass -- before the source to ensure argument parsing
is disabled.
---
 src/lib.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index e3a2b98b..ae996594 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1311,6 +1311,10 @@ impl Build {
         if self.cuda && self.files.len() > 1 {
             cmd.arg("--device-c");
         }
+        // Ensure src is not treated as a clang-cl argument, like /U.
+        if compiler.family == (ToolFamily::Msvc { clang_cl: true }) {
+            cmd.arg("--");
+        }
         cmd.arg(&obj.src);
         if cfg!(target_os = "macos") {
             self.fix_env_for_apple_os(&mut cmd)?;