Linux C++ Class templates

[albl500]

Hi,

I'm trying to compile <a href="http://taglib.github.com/">TagLib</a>, a dependency of VLC, and get the error below during the build.

If I replace `icpc` with `g++ -O3`, the compilation works fine. This has already been mentioned in <a href="http://old.nabble.com/-Bug-139190--New%3A-taglib-won%27t-compile-with-intel-c%2B%2B-compiler-td8040449.html"a thread to the TagLib developers</a>, but they don't seem to care enough to want to fix it.
Is there an icpc option that will fix this, or is this a bug / limitation in Intel's implementation? I don't know C++ well enough to fix this myself, but upload the files mentioned in the error message.
Is this <a href="http://software.intel.com/en-us/articles/template-function-with-default-argument-in-a-template-class">Intel article</a> describing the same issue?


Cheers,
Alex

cd /usr/local/src/AV/vlc/contrib/build/taglib/taglib && /opt/intel/bin/icpc   -DTAGLIB_STATIC -DHAVE_CONFIG_H -I/usr/local/src/AV/vlc/contrib/x86_64-linux-gnu/include -g -fPIC  -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib -I/usr/local/src/AV/vlc/contrib/build/taglib -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/asf -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/ogg -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/ogg/flac -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/flac -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpc -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mp4 -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/ogg/vorbis -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/ogg/speex -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/id3v2 -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/id3v2/frames -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/id3v1 -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/ape -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/wavpack -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/trueaudio -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/riff -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/riff/aiff -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/riff/wav -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mod -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/s3m -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/it -I/usr/local/src/AV/vlc/contrib/build/taglib/taglib/xm    -o CMakeFiles/tag.dir/mpeg/mpegfile.cpp.o -c /usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/mpegfile.cpp
/usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/id3v1/id3v1tag.h(62): warning #161: unrecognized #pragma
        TAGLIB_IGNORE_MISSING_DESTRUCTOR
        ^

/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.tcc(66): error #308: class template "TagLib::List<T>::ListPrivate [with T=TagLib::ByteVector]" (declared at line 245 of "/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.h") is inaccessible
  template <class TP> class List<T>::ListPrivate<TP *>  : public ListPrivateBase
                                     ^
          detected during instantiation of class "TagLib::List<T> [with T=TagLib::ByteVector]" at line 41 of "/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tbytevectorlist.h"

compilation aborted for /usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/mpegfile.cpp (code 2)

[SergeyKostrov]

Hi, >>... >>/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.tcc(66): error #308: class template "TagLib::List::ListPrivate >>[with T=TagLib::ByteVector]" (declared at line 245 of "/usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.h") is inaccessible >>template class List::ListPrivate : public ListPrivateBase >>... ... #ifndef DO_NOT_DOCUMENT template class ListPrivate; ListPrivate *d; #endif ... Did you try to UNdefine 'DO_NOT_DOCUMENT' macro at the beginning of 'tlist.h' file, like '#undef DO_NOT_DOCUMENT'? >>...Is there an icpc option that will fix this... It looks like a declaration error and C++ compilers do not fix or workaround such problems. Best regards, Sergey

[albl500]

Sergey Kostrov wrote:

Did you try to UNdefine 'DO_NOT_DOCUMENT' macro at the beginning of 'tlist.h' file, like '#undef DO_NOT_DOCUMENT'?

I have now. Same error. Good spot though. I then thought to try `grep -r 'DO_NOT_DOCUMENT' ./`, to see where else it might be defined. Other than in preprocessor macros (e.g. `#ifndef DO_NOT_DOCUMENT`), I only see it in Doxyfile and Doxyfile.cmake, as a variable in `PREDEFINED`. I thought that might translate as a preprocessor definition somewhere, but deleting it made no difference to the comilation error.

Sergey Kostrov wrote:

>>...Is there an icpc option that will fix this...

It looks like a declaration error and C++ compilers do not fix or workaround such problems.

Okay. So I changed the declaration for the one you wrote above, and a slew of other errors pop up as a result, most notable of which is probably the first:- [bash] /usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.h(246): error: explicit instantiation is not allowed in the current scope template class ListPrivate; ^ /usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.h(247): error: identifier "ListPrivate" is undefined ListPrivate *d; ^ /usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.tcc(69): error #303: explicit type is missing ("int" assumed) ListPrivate() : ListPrivateBase() {} ^ /usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.tcc(69): error: expected a ";" ListPrivate() : ListPrivateBase() {} ^ /usr/local/src/AV/vlc/contrib/build/taglib/taglib/toolkit/tlist.tcc(82): warning #12: parsing restarts here after previous syntax error std::list list; ^ /usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/id3v1/id3v1tag.h(62): warning #161: unrecognized #pragma TAGLIB_IGNORE_MISSING_DESTRUCTOR ^ [/bash] compilation aborted for /usr/local/src/AV/vlc/contrib/build/taglib/taglib/mpeg/mpegfile.cpp (code 2) Thanks for looking into this. I've only just started learning C++ really; picked up my book again only yesterday after about a year or two of negligence. I'm about 100 pages away from templates, and there's only about 5 pages written about them, so the chances of me fixing this alone are basically nil... Cheers, Alex

[SergeyKostrov]

Could you try to change 'private' to 'public' as well? ... public: #undef DO_NOT_DOCUMENT #ifndef DO_NOT_DOCUMENT template class ListPrivate; ListPrivate *d; #endif ...

[albl500]

Hi Sergey, Moving the template definition into the public method section appears to fix the issue. However, using your changes to the declaration does not work; I get practically the same errors as in my last post. So, this appears to work:- [cpp] public: .... template <class TP> class ListPrivate; ListPrivate<T> *d; [/cpp] Thanks for helping me find a working fix. Cheers, Alex

[SergeyKostrov]

>>...Moving the template definition into the public method section appears to fix the issue. However, using your changes to the declaration >>does not work... Actually, I'm not surprised that attempt to undefine 'DO_NOT_DOCUMENT' failed. It was impossible to see all dependencies without installing a complete set of sources.