[FFmpeg-devel] [PATCH]lavc/x86/simple_idct: Fix linking shared libavcodec with MS link.exe

[Andreas Rheinhardt]

Carl Eugen Hoyos:
> From 421041e7cd1bce8952756e60a0dd428f1618d75a Mon Sep 17 00:00:00 2001
> From: Carl Eugen Hoyos <ce.hoyos at grassfish.com>
> Date: Sun, 11 Sep 2022 16:02:09 +0200
> Subject: [PATCH] lavc/x86/simple_idct: Fix linking shared libavcodec with MS
>  link.exe
> 
> link.exe hangs on empty simple_idct.o
> 
> Fixes ticket #9909.
> ---
>  libavcodec/x86/simple_idct.asm | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/x86/simple_idct.asm b/libavcodec/x86/simple_idct.asm
> index dcf0da6df1..982b2f0bbb 100644
> --- a/libavcodec/x86/simple_idct.asm
> +++ b/libavcodec/x86/simple_idct.asm
> @@ -25,9 +25,9 @@
>  
>  %include "libavutil/x86/x86util.asm"
>  
> -%if ARCH_X86_32
>  SECTION_RODATA
>  
> +%if ARCH_X86_32
>  cextern pb_80
>  
>  wm1010: dw 0, 0xffff, 0, 0xffff

Thanks for bisecting this. (I don't have a MSVC setup myself to do it.)
Looking at the patch makes me feel that the very same issue might happen
with simple_idct10.asm when one tries to link a 32bit build. IMO
modifying the Makefile to no longer build these files if they are empty
would be better.

- Andreas