liboss‘ioctl’的静态声明跟在非静态声明之后

Question

我正在尝试编译一个包含liboss文件的程序，但是当我编译时，我得到了以下错误。

In file included from test.c:1:
/opt/local/include/liboss/soundcard.h:342: error: static declaration of ‘ioctl’ follows non-static declaration
/usr/include/sys/ioctl.h:97: error: previous declaration of ‘ioctl’ was here
/opt/local/include/liboss/soundcard.h:353: error: static declaration of ‘open’ follows non-static declaration
/usr/include/sys/fcntl.h:464: error: previous declaration of ‘open’ was here
/opt/local/include/liboss/soundcard.h:363: error: static declaration of ‘close’ follows non-static declaration
/usr/include/unistd.h:476: error: previous declaration of ‘close’ was here
/opt/local/include/liboss/soundcard.h:366: error: conflicting types for ‘write’
/usr/include/unistd.h:535: error: previous declaration of ‘write’ was here

出现第一个错误的行是下面这一行。

@ soundcard.h

static inline int LIBOSS_IOCTL (int x, unsigned long y,...)
{
    int result;

    va_list l;
    va_start(l,y);
    result = liboss_ioctl(x,y,l);
    va_end (l);
    return result;
}

@ ioctl.h

__BEGIN_DECLS
int ioctl(int, unsigned long, ...);
__END_DECLS

有什么方法可以让我修补soundcard.h .h，这样这就不会成为问题了吗？

太好了！一个。

规格:MacOSX10.7.4，gcc i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1

Answer 1

这听起来像是liboss试图通过重新定义ioctl函数来提供没有内核支持的OSS ioctl操作，从而在一个非原生的系统上提供一个与OSS兼容的声卡接口。如果是这种情况，您需要确保sys/ioctl.h (或任何可能包含它的头文件)不会包含在使用soundcard.h的同一源文件中。

Answer 2

只需将static添加到/usr/include/sys/ioctl.h:97、/usr/include/sys/fcntl.h:464、/usr/include/unistd.h:476和/usr/include/unistd.h:535中(并在编译后再次撤消这些更改)。

在/opt/local/include/liboss/soundcard.h:366中，将int替换为ssize_t。

# add static
sudo nano +97 /usr/include/sys/ioctl.h
- int  ioctl(int, unsigned long, ...);
+ static int  ioctl(int, unsigned long, ...);

# replace int by ssize_t
sudo nano +366 /opt/local/include/liboss/soundcard.h
- static inline int LIBOSS_WRITE (int x, const void *y, size_t l)
+ static inline ssize_t LIBOSS_WRITE (int x, const void *y, size_t l)