包装用的extern＆QUOT一个C的lib; C＆QUOT;除了内部的C ++包括 [英] Wrapping a C lib with extern "C" except an internal C++ include

问题描述

我有一个C库，我需要在C ++ code使用，所以我需要一个的externC块来包装整个库。问题是，该库似乎包括一个C ++编译code，所以包裹整个lib中也将包裹该C ++头

I have a C library that I need to use in a C++ code, so I need to wrap the whole lib with an extern "C" block. The problem is that the library seems to include a C++ compiled code, so wrapping the whole lib would also wrap that C++ header.

在 lib.h 我只包括所有内部接头我要揭露，是这样的：

Inside lib.h I only include all the internal headers I want to expose, something like this:

#ifndef LIB_H
#define LIB_H

#include "lib_foo.h"
#include "lib_bar.h"
#include "lib_baz.h"

#endif

因此​​，客户只需要包括 lib.h 用lib。

在我第一次尝试我做这个：

In my first attempt I've done this:

#ifndef LIB_H
#define LIB_H

extern "C" {
  #include "lib_foo.h"
  #include "lib_bar.h"
  #include "lib_baz.h"
}

#endif

但后来我得到一个符号查找错误，当我执行在 already_compiled_c ++任何函数的.h 。

我如何从应用的externC在 already_compiled_c ++的.h 头文件避免？

How can I avoid from applying extern "C" in the already_compiled_c++.h header file?

编辑：

解决。这不是使用的externC的一个问题，它是贯通编译的C ++库石膏正确一个问题：的在绞股蓝皂苷使用共享库节点sqlite3的

Solved. This was not a problem using extern "C", it was a problem linking the compiled c++ library with gyp correctly: Using shared library in Gyp in node-sqlite3

推荐答案

注意外部C 是不合法的C，所以它必须只包含母鸡编译为C ++

Note that extern C isn't legal C, so it must only be included hen compiling as C++.

该already_compiled_c ++ h头可能包含针对多种包括防护，所以只是包括它第一次：

The already_compiled_c++.h header probably contains a guard against multiple includes, so just include it first:

#ifndef LIB_H
#define LIB_H

# This include added so that it won't get marked extern "C" when included by lob_foo.h.
#include <already_compiled_c++.h>

#ifdef __cplusplus
extern "C" {
#endif

  #include "lib_foo.h"
  #include "lib_bar.h"
  #include "lib_baz.h"

#ifdef __cplusplus
}
#endif

#endif

注意：您需要检查是否 already_compiled_c + + H 有条件列入，并添加相应的条件语句

Note: You need to check if already_compiled_c++.h is conditionally included and add the corresponding conditionals.

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