From 1d79683ea8d64b2f4fffc68c66624096595c3575 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Ho=C5=99e=C5=88ovsk=C3=BD?=
 <martin.horenovsky@gmail.com>
Date: Thu, 30 Sep 2021 20:10:56 +0200
Subject: [PATCH] Add [[trivial_abi]] to Detail::unique_ptr when compiled with
 Clang

This decreases code size and improves performance of passing around
`unique_ptr` instances by value somewhat. It virtually guarantees
problems when combining code compiled with Clang and GCC, but that
was never supported anyway.
---
 src/catch2/internal/catch_unique_ptr.hpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/catch2/internal/catch_unique_ptr.hpp b/src/catch2/internal/catch_unique_ptr.hpp
index d3bc8417..6200542b 100644
--- a/src/catch2/internal/catch_unique_ptr.hpp
+++ b/src/catch2/internal/catch_unique_ptr.hpp
@@ -11,13 +11,22 @@
 #include <cassert>
 #include <type_traits>
 
+#if defined(__clang__) && defined(__has_attribute)
+#  if __has_attribute(trivial_abi)
+#    define TRIVIAL_ABI [[clang::trivial_abi]]
+#  endif
+#endif
+#if !defined(TRIVIAL_ABI)
+#  define TRIVIAL_ABI
+#endif
+
 namespace Catch {
 namespace Detail {
     // reimplementation of unique_ptr for improved compilation times
     // Does not support custom deleters (and thus does not require EBO)
     // Does not support arrays
     template <typename T>
-    class unique_ptr {
+    class TRIVIAL_ABI unique_ptr {
         T* m_ptr;
     public:
         constexpr unique_ptr(std::nullptr_t = nullptr):