将C和C++代码与用户定义的"typename()"函数混合在一起

Question

我正在尝试编写一个C++代码,我称之为C函数,让我们说hello_world() 这又调用了一个用户定义的typename()函数.当我在C++中包含我的C代码时,有一个编译错误,我知道这typename是C++中的一个关键字,但后来包含C代码,我正在使用

extern "C" { #include "hello_world.h"}

在我的C++代码中,仍然在编译期间出现错误,任何避免这种情况并编译代码的建议,我将不胜感激.

我无法将用户定义typename()函数的名称更改为其他名称.那怎么去......？

这样的错误: In file included from New_test.cpp:19:0: ../tools/symbol.h:38:14: error: expected unqualified-id before ‘typename’ ../tools/symbol.h:38:14: error: expected initializer before ‘typename’ In file included from New_test.cpp:604:0: /usr/include/i386-linux-gnu/sys/poll.h: In function ‘int readpacket(channel*, void*, size_t)’: /usr/include/i386-linux-gnu/sys/poll.h:48:1: error: expected unqualified-id before string constant New_test.cpp:612:52: error: ‘poll’ was not declared in this scope

Answer 1

您可能需要在头文件中使用以下内容:

文件:common_header.h

#ifdef __cplusplus
extern "C" {
#endif

extern void newname_typename();

#ifdef __cplusplus
}
#endif

然后是一个只有C的编译单元:

#include "common_header.h"
#include "hello_world.h"
void newname_typename() {
   typename();
}

在C++中:

#include "common_header.h"

void do_stuff() {
  newname_typename();
}

并且您需要确保您的Makefile最终执行以下操作:

gcc c_only_code.c -o something1.o
g++ cplus_only_code.cxx -o something2.o
gcc something1.o something2.o <other stuff> -o binary  

Answer 2

以下是如何对事物进行分区以便正确编译和链接的方法.C++源文件不需要知道有一个函数被调用typename().

档案' some_c.c':

#include "some_c.h"

void typename(); /* This declaration will suffice. */

void hello_world()
{
    typename();
}

档案' some_c.h'

/* References to typename()'s declaration must be deleted from this
** header file.  If it turns out that there are some other parts of the
** header file which somehow depend on the typename() declaration, you
** must separate this into multiple header files. 
*/
void hello_world();

档案' some_cpp.cpp':

/* Arguably this should show up in some_c.h, protected by
** #ifdef __cplusplus barriers.  But this should work too:
*/
extern "C" {
#include "some_c.h"
}

void SomeClass::someMethod()
{
    hello_world();
}