# Reuse rules_cc's installed SDK setup with an explicitly declared LLVM repo.
# Only the V8 repository has native_llvm; ordinary local_config_cc behaves
# exactly as upstream, including the caller's BAZEL_LLVM/USE_CLANG_CL.
# Preserve DUMPBIN when selecting clang-cl; the upstream MSVC template uses it.
diff --git a/cc/private/toolchain/windows_cc_configure.bzl b/cc/private/toolchain/windows_cc_configure.bzl
--- a/cc/private/toolchain/windows_cc_configure.bzl
+++ b/cc/private/toolchain/windows_cc_configure.bzl
@@ -539,6 +539,12 @@
         The path to the LLVM installation, or None if not found.
     """

+    # Codex's opt-in V8 toolchain supplies a Bazel-fetched compiler.
+    # Ordinary cc_autoconf repositories have no such attribute.
+    llvm_label = getattr(repository_ctx.attr, "native_llvm", None)
+    if llvm_label:
+        return str(repository_ctx.path(llvm_label).dirname).replace("/", "\\")
+
     # 1. Check if BAZEL_LLVM is already set by user.
     bazel_llvm = _get_path_env_var(repository_ctx, "BAZEL_LLVM")
     if bazel_llvm:
@@ -602,7 +608,7 @@

 def _use_clang_cl(repository_ctx):
     """Returns True if USE_CLANG_CL is set to 1."""
-    return _get_env_var(repository_ctx, "USE_CLANG_CL", default = "0") == "1"
+    return getattr(repository_ctx.attr, "native_llvm", None) != None or _get_env_var(repository_ctx, "USE_CLANG_CL", default = "0") == "1"

 def _find_missing_llvm_tools(repository_ctx, llvm_path):
     """Check if any required tool is missing under given LLVM path."""
@@ -716,6 +722,7 @@

         build_tools["CL"] = find_llvm_tool(repository_ctx, llvm_path, "clang-cl.exe")
         build_tools["ML"] = find_msvc_tool(repository_ctx, vc_path, "ml64.exe", "x64")
+        build_tools["DUMPBIN"] = find_msvc_tool(repository_ctx, vc_path, "dumpbin.exe", target_arch)
         build_tools["LINK"] = find_llvm_tool(repository_ctx, llvm_path, "lld-link.exe")
         if not build_tools["LINK"]:
             build_tools["LINK"] = find_msvc_tool(repository_ctx, vc_path, "link.exe", "x64")