ffmpeg | branch: master | Martin Storsjö <martin@martin.st> | Mon Jan 16 00:20:24 2023 +0200| [01f58f36465a13db069641cca47fa9777f03b875] | committer: Martin Storsjö lavu/video_enc_params: Avoid relying on an undefined C construct The construct of using offsetof on a (potentially anonymous) struct defined within the offsetof expression, while supported by all current compilers, has been declared explicitly undefined by the C standards committee [1]. Clang recently got a change to identify this as an issue [2]; initially it was treated as a hard error, but it was soon after softened into a warning under the -Wgnu-offsetof-extensions option (not enabled automatically as part of -Wall though). Nevertheless - in this particular case, it's trivial to fix the code not to rely on the construct that the standards committee has explicitly called out as undefined. [1] https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2350.htm [2] https://reviews.llvm.org/D133574 Signed-off-by: Martin Storsjö <martin@martin.st>

http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=01f58f36465a13db06...

libavutil/video_enc_params.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/libavutil/video_enc_params.c b/libavutil/video_enc_params.c index 54bfed0ed9..33592dc128 100644 --- a/libavutil/video_enc_params.c +++ b/libavutil/video_enc_params.c @@ -27,11 +27,11 @@ AVVideoEncParams *av_video_enc_params_alloc(enum AVVideoEncParamsType type, unsigned int nb_blocks, size_t *out_size) { - const size_t blocks_offset = offsetof( - struct { - AVVideoEncParams p; - AVVideoBlockParams b; - }, b); + struct TestStruct { + AVVideoEncParams p; + AVVideoBlockParams b; + }; + const size_t blocks_offset = offsetof(struct TestStruct, b); size_t size = blocks_offset; AVVideoEncParams *par;