OGG Vorbis：已定义，但未使用-如何抑制？

Question

我在学校有一个小组项目（3D FPS游戏），我使用C ++中的OpenAL和OGG Vorbis编程音频。 我们的编译器将警告我们有关已定义但未使用的变量的信息，这原来是Vorbis的问题。 当我编译应用程序时，得到以下信息：

[  8%] Building CXX object CMakeFiles/fps.dir/src/audio/Sound.cpp.o
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:82:21: warning: ‘OV_CALLBACKS_NOCLOSE’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:89:21: warning: ‘OV_CALLBACKS_STREAMONLY’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:96:21: warning: ‘OV_CALLBACKS_STREAMONLY_NOCLOSE’ defined but not used [-Wunused-variable]
[  9%] Building CXX object CMakeFiles/fps.dir/src/audio/MenuAudioController.cpp.o
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:75:21: warning: ‘OV_CALLBACKS_DEFAULT’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:82:21: warning: ‘OV_CALLBACKS_NOCLOSE’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:89:21: warning: ‘OV_CALLBACKS_STREAMONLY’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:96:21: warning: ‘OV_CALLBACKS_STREAMONLY_NOCLOSE’ defined but not used [-Wunused-variable]
[ 10%] Building CXX object CMakeFiles/fps.dir/src/audio/GameAudioController.cpp.o
In file included from /home/berzeger/FPS/FPS/trunk/game/src/audio/GameAudioController.cpp:1:0:
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:75:21: warning: ‘OV_CALLBACKS_DEFAULT’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:82:21: warning: ‘OV_CALLBACKS_NOCLOSE’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:89:21: warning: ‘OV_CALLBACKS_STREAMONLY’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:96:21: warning: ‘OV_CALLBACKS_STREAMONLY_NOCLOSE’ defined but not used [-Wunused-variable]
[ 11%] Building CXX object CMakeFiles/fps.dir/src/audio/AudioController.cpp.o
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:75:21: warning: ‘OV_CALLBACKS_DEFAULT’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:82:21: warning: ‘OV_CALLBACKS_NOCLOSE’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:89:21: warning: ‘OV_CALLBACKS_STREAMONLY’ defined but not used [-Wunused-variable]
/home/berzeger/FPS/FPS/trunk/game/src/audio/../../include/vorbis/vorbisfile.h:96:21: warning: ‘OV_CALLBACKS_STREAMONLY_NOCLOSE’ defined but not used [-Wunused-variable]

等等。 您会看到这是一团糟，重要的事情容易丢失。

我似乎无法找到一种方法来抑制vorbis的未使用变量。 我试过了

#define OV_EXCLUDE_STATIC_CALLBACKS

但这会禁用所有的vorbis定义，这不是我想要的。

有人可以帮忙吗？ 提前致谢！

Answer 1

就个人而言，我会修改构建脚本以过滤掉那些特定的警告，但是如果您不打算这样做...

您可以创建一个包装器头文件，包括包装器文件而不是vorbis头文件，并在包装​​器头文件中使用问题变量，以使警告消失。 假设它们是整数常量，则应满足以下条件。

//File: myvorbisfile.h
#include "vorbisfile.h"

// Dummy function in the anonymous namespace 
// to suppress the unused variables
namespace
{
   int hide_unused_variables()
   {
     return 0
      + OV_CALLBACKS_NOCLOSE
      + OV_CALLBACKS_DEFAULT
      ... Fill in the rest ...
    }
}

Answer 2

好的，我想我已经找到解决方案了。 我们已将头文件复制到我们的应用程序目录中，因此我以这种方式包含了vorbisfile.h：

#include "../../include/vorbis/vorbisfile.h"

当我将此行更改为：

#include <vorbis/vorbisfile.h>

警告消失了。 不知道为什么。