From 4af7c6bdee715c9a2f317b99b7f7c6e80abae1e7 Mon Sep 17 00:00:00 2001
From: Ross Smyth <18294397+RossSmyth@users.noreply.github.com>
Date: Thu, 31 Jul 2025 11:23:13 -0400
Subject: [PATCH] lib.systems: Add examples & helpers for MSVC

---
 lib/systems/default.nix  |  2 ++
 lib/systems/examples.nix | 11 +++++++++++
 lib/systems/inspect.nix  |  4 ++++
 3 files changed, 17 insertions(+)

diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index edb69cc43194..60fa5832efa9 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -120,6 +120,8 @@ let
         libc =
           if final.isDarwin then
             "libSystem"
+          else if final.isMsvc then
+            "ucrt"
           else if final.isMinGW then
             "msvcrt"
           else if final.isWasi then
diff --git a/lib/systems/examples.nix b/lib/systems/examples.nix
index 152ac4ddc0ec..a3ac648dee18 100644
--- a/lib/systems/examples.nix
+++ b/lib/systems/examples.nix
@@ -372,6 +372,17 @@ rec {
     useLLVM = true;
   };
 
+  # Target the MSVC ABI
+  x86_64-windows = {
+    config = "x86_64-pc-windows-msvc";
+    useLLVM = true;
+  };
+
+  aarch64-windows = {
+    config = "aarch64-pc-windows-msvc";
+    useLLVM = true;
+  };
+
   # BSDs
 
   aarch64-freebsd = {
diff --git a/lib/systems/inspect.nix b/lib/systems/inspect.nix
index 2cc009133f2a..65fdb9ee1959 100644
--- a/lib/systems/inspect.nix
+++ b/lib/systems/inspect.nix
@@ -344,6 +344,10 @@ rec {
       kernel = kernels.windows;
       abi = abis.gnu;
     };
+    isMsvc = {
+      kernel = kernels.windows;
+      abi = abis.msvc;
+    };
     isWasi = {
       kernel = kernels.wasi;
     };