From ab4795a085cd3deacb5e4bbaf527d66171361024 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Wed, 17 Jul 2019 05:29:40 +0200 Subject: matroskadec: Add sizes to forward declarations Unknown-length elements end when an element not allowed in them, but allowed at a higher level is encountered. In order to check for this, c1abd95a added a pointer to every syntax level's parent to each EbmlSyntax. Given that the parent must of course also reference the child in order to be able to enter said child level, one needs to use forward declarations. These forward declarations constitute tentative definitions and tentative definitions with internal linkage (like our syntaxes) must not be an incomplete type. Yet they were an incomplete type and while GCC and Clang did not even warn about this (on default warning levels), it broke compilation with MSVC. Therefore this commit adds the sizes. Signed-off-by: Andreas Rheinhardt --- libavformat/matroskadec.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'libavformat/matroskadec.c') diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index b97189e674..fb0356e7b7 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -389,12 +389,16 @@ typedef struct MatroskaDemuxContext { #define CHILD_OF(parent) { .def = { .n = parent } } -static const EbmlSyntax ebml_syntax[], matroska_segment[], matroska_track_video_color[], matroska_track_video[], - matroska_track[], matroska_track_encoding[], matroska_track_encodings[], - matroska_track_combine_planes[], matroska_track_operation[], matroska_tracks[], - matroska_attachments[], matroska_chapter_entry[], matroska_chapter[], matroska_chapters[], - matroska_index_entry[], matroska_index[], matroska_tag[], matroska_tags[], matroska_seekhead[], - matroska_blockadditions[], matroska_blockgroup[], matroska_cluster_parsing[]; +// The following forward declarations need their size because +// a tentative definition with internal linkage must not be an +// incomplete type (6.7.2 in C90, 6.9.2 in C99). +// Removing the sizes breaks MSVC. +static const EbmlSyntax ebml_syntax[3], matroska_segment[9], matroska_track_video_color[15], matroska_track_video[19], + matroska_track[27], matroska_track_encoding[6], matroska_track_encodings[2], + matroska_track_combine_planes[2], matroska_track_operation[2], matroska_tracks[2], + matroska_attachments[2], matroska_chapter_entry[9], matroska_chapter[6], matroska_chapters[2], + matroska_index_entry[3], matroska_index[2], matroska_tag[3], matroska_tags[2], matroska_seekhead[2], + matroska_blockadditions[2], matroska_blockgroup[8], matroska_cluster_parsing[8]; static const EbmlSyntax ebml_header[] = { { EBML_ID_EBMLREADVERSION, EBML_UINT, 0, offsetof(Ebml, version), { .u = EBML_VERSION } }, -- cgit v1.2.3