什么是nameser_compat.h，为什么不包含它？

Question

我想获得一些代码来编译，试图在nameser_compat.h头文件中使用一些定义。如果设置了一些BIND兼容性，这个文件显然包含在nameser.h中。

我试着在OSX上编译，显然这个值没有设置，因为它没有拉入文件。我应该手动将nameser_compat.h导入到我的代码中添加到nameser.h中吗？

Answer 1

在我的Mac OS X 10.7.4的机器，我可以找到三个相关文件看：

/usr/include/arpa/nameser.h 
/usr/include/arpa/nameser_compat.h 
/usr/include/nameser.h 

我把这个简单的一段代码（在文件xx.c）：

#include <nameser.h> 
int main(void) { return 0; } 

并编译它像这样获得输出显示：

$ /usr/bin/gcc -O3 -g -std=c99 -Wall -Wextra -DBIND_8_COMPAT -H -c xx.c 
. /usr/include/nameser.h 
.. /usr/include/arpa/nameser_compat.h 
... /usr/include/machine/endian.h 
.... /usr/include/i386/endian.h 
..... /usr/include/sys/cdefs.h 
...... /usr/include/sys/_symbol_aliasing.h 
...... /usr/include/sys/_posix_availability.h 
..... /usr/include/sys/_endian.h 
...... /usr/include/libkern/_OSByteOrder.h 
....... /usr/include/sys/_types.h 
........ /usr/include/machine/_types.h 
......... /usr/include/i386/_types.h 
....... /usr/include/libkern/i386/_OSByteOrder.h 
.. /usr/include/sys/param.h 
... /usr/include/sys/types.h 
.... /usr/include/sys/appleapiopts.h 
.... /usr/include/machine/types.h 
..... /usr/include/i386/types.h 
...... /usr/include/i386/_types.h 
.... /usr/include/sys/_structs.h 
... /usr/include/sys/syslimits.h 
... /usr/include/machine/param.h 
.... /usr/include/i386/param.h 
..... /usr/include/i386/_param.h 
... /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/include/limits.h 
.... /usr/llvm-gcc-4.2/bin/../lib/gcc/i686-apple-darwin11/4.2.1/include/syslimits.h 
.... /Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/include/limits.h 
..... /Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2/lib/gcc/i686-apple-darwin11/4.2.1/include/syslimits.h 
..... /usr/include/limits.h 
...... /usr/include/machine/limits.h 
....... /usr/include/i386/limits.h 
........ /usr/include/i386/_limits.h 
... /usr/include/sys/signal.h 
.... /usr/include/machine/signal.h 
..... /usr/include/i386/signal.h 
...... /usr/include/i386/_structs.h 
.... /usr/include/sys/_structs.h 
..... /usr/include/machine/_structs.h 
...... /usr/include/i386/_structs.h 
....... /usr/include/mach/i386/_structs.h 
Multiple include guards may be useful for: 
/usr/include/sys/_symbol_aliasing.h 
$ 

这表明与包含集合，nameser_compat.h标题。源代码显示，可以预期：

#ifndef _NAMESER_9_H_ 
#define _NAMESER_9_H_ 

#ifdef BIND_8_COMPAT 
#include <arpa/nameser_compat.h> 
#endif