问题描述
你好，
我有问题在C项目中调用c ++函数。我有一个来自cpp文件的
头文件。在头文件中，函数是
decleared" int GetHostIPAddresses（ini i）;"。我在c文件中包含头文件
并调用函数GetHostIPAddresses（1）;.但
链接器没有找到该功能。有人能给我一个暗示是什么
错了。
祝你好运
Falk
Hello,
I have the problem to call a c++ funtion in a C project. I have a
header file from the cpp file. In the header file the function is
decleared "int GetHostIPAddresses(ini i);". I inlcude the header file
in the c file and call the function GetHostIPAddresses(1);. But the
linker doesn''t found the function. Can someone give me a hint what is
wrong.
Best regards
Falk
推荐答案
在comp.lang.c ++中问这个可能会更好，因为
这更多是在专业领域那里的常客是
。另见
无论如何我都会尝试一个简短的解释（这可能是错误的因为我
不是C ++专家！）：在C ++中你可以有几个功能，
同名，只能用数字来区分和
他们的论点类型。为了让链接器能够区分这些函数，这些函数会自动重命名函数auto-
，通常是通过在名称上添加一些文本
表示参数的数量和类型，例如
foo（int）变为foo_i
foo（double）变为foo_d
（这是一个例子，不是真实的，不同的C ++编译器
可能以不同的方式做到这一点）。如果您知道这个受损的名称然后
您可以相应地更改函数的调用，即在C代码中使用
损坏的名称。显而易见的缺点是，这个
只适用于您确定的C ++编译器如何使用
名称重整。
如果您可以更改C ++源代码并且只有一个具有该名称的
函数，那么您可以使用
在C ++
头文件中声明它。
externC void f（int i，char c，float x）;
以防止C ++编译器破坏函数名。
问候， Jens
-
\ Jens Thoms Toerring ___
\ __________________________
It probably would be better to ask this in a comp.lang.c++ since
this is more in the territory of expertise of the regulars over
there. See also
http://www.parashift.com/c++-faq/mixing-c-and-cpp.html
I try a short explanation anyway (which might be wrong since I
am not a C++ expert!): In C++ you can have several functons with
the same name that are only distinguished by the number and
types of their arguments. To allow the linker to distinuish be-
tween these functions the compiler renames the functions auto-
matically, typically by appending some text to the names that
indicates the number and types of arguments, like
foo( int ) becomes foo_i
foo( double ) becomes foo_d
(this is an example, not the real thing, different C++ compilers
may do it in different ways). If you know this mangled name then
you can change the call of the function accordingly, i.e. use the
mangled name in the C code. The obvious drawback is that this
only works for the C++ compiler you determined for how it does
the name mangling.
If you can change the C++ source and there''s only a single
function with that name then you can declare it in the C++
header file with
extern "C" void f(int i, char c, float x);
to keep the C++ compiler from mangling the function name.
Regards, Jens
--
\ Jens Thoms Toerring ___ jt@toerring.de
\__________________________ http://toerring.de
你不能这样做。 C ++有调用C函数的规定，但C
对C ++一无所知。即使是C ++调用也只限于同一个编译器。
-
Chuck F（cinefalconer at maineline dot net）
可用于咨询/临时嵌入式和系统。
< http://cbfalconer.home.att.net>
-
通过
You can''t do it. C++ has provisions for calling C functions, but C
doesn''t know anything about C++. Even the C++ calling is
restricted to the same compiler.
--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net>
--
Posted via a free Usenet account from http://www.teranews.com
获取C ++目标文件并将其转储为ascii。你应该看到排列的所有
函数，但因为它是C ++，它们有搞笑的字符和
与它们相关的其他东西。
提取名称 - 可能需要两到三次尝试 - 将其放入您的C />
来源，并尝试链接。最终你会成功。然后仔细测试函数
以确保C ++没有传递任何额外的参数。
-
免费游戏和编程好东西。
Get the C++ object file and dump it as ascii. You should see all the
functions arrayed, but because it is C++ they have funny characters and
other things associated with them.
Extract the name - which may take two or three attempts - put it in your C
source, and try to link. Eventually you will succeed. Then test the function
carefully to make sure C++ isn''t passing it any extra arguments.
--
Free games and programming goodies.
http://www.personal.leeds.ac.uk/~bgy1mm
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