Does not compile under MSVC

[neheb]

When linking against libmatroska, linking errors occur:

src_KaxTracks.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxInfoData.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxSeekHead.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxSegment.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxSemantic.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxCluster.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxContexts.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxCues.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxCuesData.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxAttached.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxAttachments.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxBlock.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxBlockData.cpp.obj : error LNK2001: unresolved external symbol "protected: static unsigned __int64 const libebml::EbmlDate::UnixEpochDelay" (?UnixEpochDelay@EbmlDate@libebml@@1_KB)
src_KaxTracks.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxInfoData.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxSeekHead.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxSegment.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxSemantic.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxCluster.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxContexts.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxCues.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxCuesData.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxAttached.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxAttachments.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxBlock.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxBlockData.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlCrc32::ClassInfos" (?ClassInfos@EbmlCrc32@libebml@@2VEbmlCallbacks@2@B)
src_KaxContexts.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlHead::ClassInfos" (?ClassInfos@EbmlHead@libebml@@2VEbmlCallbacks@2@B)
src_KaxSegment.cpp.obj : error LNK2001: unresolved external symbol "public: static class libebml::EbmlCallbacks const libebml::EbmlHead::ClassInfos" (?ClassInfos@EbmlHead@libebml@@2VEbmlCallbacks@2@B)
subprojects\libmatroska-release-1.6.3\libmatroska.dll : fatal error LNK1120: 3 unresolved externals

for UnixEpochDelay, defining it directly fixes the error. I'm not sure about the others.

[robUx4]

These are all "global variables" or rather class static variables. Are you building as libebml/libmatroska as a DLLs or static libraries ? AFAIK it's not possible in a clean way to share global variables between DLLs on Windows.

mkvtoolnix and VLC use libebml and libmatroska as static libraries on Windows so they don't have this problem. Our CMake build file system also uses a static library by default on Windows and when compiled with BUILD_SHARED_LIBS set these static variables are not exported, even when using EBML_DLL_API in their definition.

[neheb]

shared lib, aka dll. I’ll try static.

[neheb]

Partial fix: #94

[neheb]

static compilation works.

[robUx4]

Does #94 fix the whole DLL issue ? It seems the EbmlCrc32::ClassInfos is defined by DEFINE_EBML_CLASS_GLOBAL.

EbmlVoid is also defined that way so it should have the same problem (when compiling the test samples).

We could also move these lines in the header files, as in #94 and hopefully that would fix the issue

DEFINE_EBML_CLASS_GLOBAL(EbmlCrc32, 0xBF, 1, "EBMLCrc32\0ratamadabapa")
DEFINE_EBML_CLASS_GLOBAL(EbmlVoid, 0xEC, 1, "EBMLVoid")

[neheb]

#94 is only a partial fix.

[neheb]

@robUx4 fun MSVC issue now...

 Found ninja-1.10.2 at "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja\ninja.EXE"
WARNING: msvc does not support C++11; attempting best effort; setting the standard to C++14

I guess libebml should be bumped to C++14 now.

[neheb]

Through some unexplained reason, this no longer fails. Closing.

[neheb]

never mind

[neheb]

I think the issue is me not implementing hidden visibility properly. I can't reproduce this after fixing.