From a13cf846e0c6c9f667be505eb1aae8160240cf4a Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu@google.com>
Date: Thu, 26 Jun 2025 08:40:47 -0700
Subject: [PATCH] [ASTMatchers] Migrate away from ArrayRef(std::nullopt) (NFC)
 (#145840)

ArrayRef has a constructor that accepts std::nullopt.  This
constructor dates back to the days when we still had llvm::Optional.

Since the use of std::nullopt outside the context of std::optional is
kind of abuse and not intuitive to new comers, I would like to move
away from the constructor and eventually remove it.

This patch migrates away from std::nullopt in favor of ArrayRef<T>().
Note that {} would be ambiguous for perfect forwarding to work here.
---
 clang/lib/ASTMatchers/Dynamic/Marshallers.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/ASTMatchers/Dynamic/Marshallers.h b/clang/lib/ASTMatchers/Dynamic/Marshallers.h
index 0e640cbada72..d44e42a524f2 100644
--- a/clang/lib/ASTMatchers/Dynamic/Marshallers.h
+++ b/clang/lib/ASTMatchers/Dynamic/Marshallers.h
@@ -1060,7 +1060,7 @@ makeMatcherAutoMarshall(ReturnType (*Func)(), StringRef MatcherName) {
   BuildReturnTypeVector<ReturnType>::build(RetTypes);
   return std::make_unique<FixedArgCountMatcherDescriptor>(
       matcherMarshall0<ReturnType>, reinterpret_cast<void (*)()>(Func),
-      MatcherName, RetTypes, std::nullopt);
+      MatcherName, RetTypes, ArrayRef<ArgKind>());
 }
 
 /// 1-arg overload