avutil/attributes: enable av_flatten when available

kasper93 · kasper93 · commit 9c63742425aa · 2026-03-22T15:55:54.000Z
This enables av_flatten on Clang in particular. It was disabled because at the time this attribute was not supported. It was implemented in Clang/LLVM 3.5 [1]. Use `__has_attribute` to check for availability. This has been added in Clang 2.9 [2]. This reverts change 5858a67. [1] llvm/llvm-project@41af7c2 [2] llvm/llvm-project@274a70e Signed-off-by: Kacper Michajłow <kasper93@gmail.com>
diff --git a/libavutil/attributes.h b/libavutil/attributes.h
@@ -111,7 +111,7 @@
 #    define av_cold
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(4,1) && !defined(__llvm__)
+#if (AV_GCC_VERSION_AT_LEAST(4,1) && !defined(__clang__ )) || AV_HAS_ATTRIBUTE(flatten)
 #    define av_flatten __attribute__((flatten))
 #else
 #    define av_flatten
