Rollup merge of #68231 - danielframpton:windows-crosscompile, r=alexcrichton

Better support for cross compilation on Windows.

I have been investigating enabling panic=unwind for aarch64-pc-windows-msvc (see #65313) and building rustc and cargo hosted on aarch64-pc-windows-msvc.

Without the libpath changes we were trying to link a mix of amd64 and arm64 binaries.

Without the cmake system name change, the llvm build was trying to run an arm64 build tool on the x86_64 build machine.

That said, I haven't tested all different combinations here and am very open to resolving this a different way.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index ce977f1bbc4..89e1a7319cf 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -230,6 +230,8 @@ impl Step for Llvm {
                 cfg.define("CMAKE_SYSTEM_NAME", "NetBSD");
             } else if target.contains("freebsd") {
                 cfg.define("CMAKE_SYSTEM_NAME", "FreeBSD");
+            } else if target.contains("windows") {
+                cfg.define("CMAKE_SYSTEM_NAME", "Windows");
             }
 
             cfg.define("LLVM_NATIVE_BUILD", builder.llvm_out(builder.config.build).join("build"));