On Thu, 12 Jun 2025, Martin Storsjö wrote:
This fixes building with Clang in MSVC mode, for x86, which was broken in 6e49b8699657b808b7dc80033f2c3f2d0e029fa3 (in Nov 2024); previously it failed with undefined symbols for the constants defined with DECLARE_ASM_CONST, accessed via inline assembly.Before 57861911a34e1c33796be97f2b2f44e05fffd647, there was an #elif defined(__GNUC__) || defined(__clang__) case before the #elif defined(_MSC_VER) case for defining DECLARE_ASM_CONST, which included av_used. (This case included the explicit "defined(__clang__)" since f637046d3134a331e4b5a7243ac3dfb92735b8a5.) After 57861911a34e1c33796be97f2b2f44e05fffd647, it used the generic definition of DECLARE_ASM_CONST that also included av_used - which also worked for Clang in MSVC mode. But after 6e49b8699657b808b7dc80033f2c3f2d0e029fa3, Clang in MSVC mode ended up using the MSVC specific variant which lacked the av_used declaration, causing linker errors due to undefined symbols. --- libavutil/mem_internal.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavutil/mem_internal.h b/libavutil/mem_internal.h index d58881d09c..78adc4f407 100644 --- a/libavutil/mem_internal.h +++ b/libavutil/mem_internal.h @@ -82,8 +82,8 @@ #define DECLARE_ASM_CONST(n,t,v) alignas(FFMIN(n, 16)) static const t av_used v #elif defined(_MSC_VER) #define DECLARE_ALIGNED_T(n,t,v) __declspec(align(n)) t v - #define DECLARE_ASM_ALIGNED(n,t,v) __declspec(align(n)) t v - #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v + #define DECLARE_ASM_ALIGNED(n,t,v) __declspec(align(n)) t av_used v + #define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t av_used v #else #define DECLARE_ALIGNED_T(n,t,v) alignas(n) t v #define DECLARE_ASM_ALIGNED(n,t,v) alignas(n) t av_used v -- 2.43.0
OK'd by Hendrik on irc, as I've tested it with both clang and actual MSVC - will push.
// Martin _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
