在C项目中使用C ++库导致一长串错误 [英] Using a C++ Library in a C Project causes a long list of errors
问题描述
我有一个使用 C ++库的 C项目。但是,如果我编译C项目,我得到一个很长的列表未定义的引用XY错误。
这些错误是由C ++引起的参考:
编译时发生错误:
在函数`< c function>'中:
隐式声明函数`< function>'
[...]
(列表短路)
其中< c function> 是来自C项目和< function> 来自C ++库的函数。
链接时出错:
未定义的引用`std :: cerr'
未定义的引用到`std :: basic_ostream< char,std :: char_traits<炭> >&安培;的std ::运营商LT;< <的std :: char_traits<炭> >(std :: basic_ostream< char,std :: char_traits< char>&&& char char * *)'
未定义的引用`std :: basic_ostream< char,std :: char_traits< char> >&安培;的std ::运营商LT;< < char,std :: char_traits< char>,std :: allocator< char> >(std :: basic_ostream< char,std :: char_traits< char>&&&&& std :: basic_string< char,std :: char_traits< char>,std :: allocator< char>> const&
[...]
未定义的引用`__gxx_personality_v0'
更多未定义的引用`__gxx_personality_v0'跟随
(很多错误 - 示例短路)
在静态C ++库中,我的类型/由 externC封闭
#ifdef __cplusplus
externC
{
#endif
void example();
#ifdef __cplusplus
}
#endif
为了确保这一点,所有的 #include
引用C ++库都被这样一个 externC
编译器:使用 g ++ 编译 C项目使用 gcc - 均来自 MinGW 。
CL链接): gcc -L< search-path here> -shared [...] -lstdc ++ -l< C ++库set here>
请注意 -lstdc ++
标志
注意
- C项目只包含
.c
和.h
文件 - 没有.cpp
- 将一个虚拟cpp文件放在喜欢的
- MinGW和Eclipse CDT Indigo
这个问题/ 376966 / using-cc-static-libraries-from-iphone-objectivec-
- C ++库的名称如
lib< NAME> .a
- 它与-l< NAME>
,搜索路径设置。
编辑:
使用 g ++
作为链接器:未定义引用
std :: cerr'`等已经没了,但是我收到另一个错误列表:
警告:.drectve`-aligncomm:___ hexdig_D2A,5'无法识别的
未定义引用`<来自C ++库的函数/类/方法>'
[...]
未定义的引用`_Unwind_Resume'
[...]
未定义引用`__gxx_personality_v0'
更多未定义的引用`__gxx_personality_v0'跟随
未定义引用`__chkstk_ms'
[...]
(list shorted)
_Unwind_Resume
在c ++库的 nm
中可用。
示例:
这部分在库(C ++)中:
Test.h - 标题
#ifndef TEST_H_
pre>
#define TEST_H_
// ---纯C ++这里---
#ifdef __cplusplus
#include< string> / *(1)* /
class Test
{
public:
Test();
void aMethod();
private:
int i;
};
#endif
// --- Mixed(C / C ++)here ---
#ifdef __cplusplus
externC
{
#endif
extern void doTest();
extern void invoke();
#ifdef __cplusplus
}
#endif
#endif / * TEST_H_ * /
Test.cpp - 执行C ++部分
#includeTest.h
Test :: Test():i(0){}
void Test :: aMethod ()
{
this-> i ++;
}
void invoke()
{
测试我;
i.aMethod();
}
Test.c - C接口的实现仍然在图书馆!)
#includeTest.h
void doTest()
{
invoke();
}
现在,这里是第二个项目(纯C)的一部分: / p>
#includeTest.h
int main(int argc,char * argv [])
{
doTest();
return 0;
}
(1)
:如果我删除包含我可以编译C项目。但是,添加一个包含任何类或c ++的东西会导致很多错误,而链接。不幸的是,我需要包括课程等。
Btw。这里是这个例子的错误:
Test.cpp :( .text + 0x1b):未定义的引用`std: :basic_string< char,std :: char_traits< char>,std :: allocator< char> > :: basic_string()'
Test.cpp :(。文本+ 0x64):未定义的引用`_Unwind_Resume'
Test.cpp :(。文本$ _ZN4TestD1Ev [Test ::〜Test() ] + 0x12):未定义的引用到`std :: basic_string< char,std :: char_traits< char>,std :: allocator< char> > ::〜basic_string()'
Test.cpp :(。eh_frame + 0x6b):未定义的引用`__gxx_personality_v0'
设置
-lstdc ++
标记之后(!)库的标志我得到只这些:Test.cpp :(。text + 0x64):未定义的引用`_Unwind_Resume'
Test.cpp :(。eh_frame + 0x6b):未定义的引用到`__gxx_personality_v0'
解决方案MinGW GCC。
- 使用 GCC 3.4.5 :错误 / li>
- 使用 GCC 4.7.2 :无错误
还要确保 -lstdc ++
是 -l </ $ c的最后(!) $ c> flags。
I have a C Project which uses a C++ library. However, if i compile the C Project i get a long list of "undefined reference to XY" errors.
Those errors are caused by C++ references:
Errors while compiling:
In function `<c function>':
implicit declaration of function `<function>'
[...]
(list shorted)
Where <c function> is the calling function from C Project and <function> the function from the C++ library.
Errors while linking:
undefined reference to `std::cerr'
undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <char, std::char_traits<char>, std::allocator<char> >(std::basic_ostream<char, std::char_traits<char> >&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
[...]
undefined reference to `__gxx_personality_v0'
more undefined references to `__gxx_personality_v0' follow
(lots of errors - example shorted)
In the static C++ library my types / functions are enclosed by extern "C"
block:
#ifdef __cplusplus
extern "C"
{
#endif
void example();
#ifdef __cplusplus
}
#endif
To ensure this, all the #include
's referring to C++ library are surrounded by such a extern "C"
block too.
Compiler: The C++ library is compiled using g++, the C project using gcc - both from MinGW.
CL (Linking): gcc -L<search-path here> -shared [...] -lstdc++ -l<C++ library set here>
Please note the -lstdc++
flag.
Note:
- The C project contains only
.c
and.h
files – no.cpp
- Putting a "dummy" cpp file in like stated here didn't work
- MinGW and Eclipse CDT Indigo
- The C++ Library has a name like
lib<NAME>.a
- it's linked with-l<NAME>
, search path is set.
Edit:
Using g++
as linker: undefined reference to
std::cerr'` etc. are gone, but i get another list of errors:
Warning: .drectve `-aligncomm:"___hexdig_D2A",5' unrecognized
undefined reference to `<function / class / method from C++ Library>'
[...]
undefined reference to `_Unwind_Resume'
[...]
undefined reference to `__gxx_personality_v0'
more undefined references to `__gxx_personality_v0' follow
undefined reference to `__chkstk_ms'
[...]
(list shorted)
eg. _Unwind_Resume
is available in nm
of the c++ library.
Example:
This part is in the Library (C++):
Test.h - Header
#ifndef TEST_H_
#define TEST_H_
// --- Pure C++ here ---
#ifdef __cplusplus
#include <string> /* (1) */
class Test
{
public:
Test();
void aMethod();
private:
int i;
};
#endif
// --- Mixed (C / C++ ) here ---
#ifdef __cplusplus
extern "C"
{
#endif
extern void doTest();
extern void invoke();
#ifdef __cplusplus
}
#endif
#endif /* TEST_H_ */
Test.cpp - Implementation of C++ part
#include "Test.h"
Test::Test() : i(0) { }
void Test::aMethod()
{
this->i++;
}
void invoke()
{
Test i;
i.aMethod();
}
Test.c - Implementation of C Interface (still in library!)
#include "Test.h"
void doTest()
{
invoke();
}
Now, here comes the part of the second project (pure C):
#include "Test.h"
int main(int argc, char* argv[])
{
doTest();
return 0;
}
(1)
: If i remove that include i can compile the C Project. But adding one include for any kind of class or c++ stuff causes lots of errors while linking. unfortunately i need to include classes etc..
Btw. here's the error i get for this example:
Test.cpp:(.text+0x1b): undefined reference to `std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string()'
Test.cpp:(.text+0x64): undefined reference to `_Unwind_Resume'
Test.cpp:(.text$_ZN4TestD1Ev[Test::~Test()]+0x12): undefined reference to `std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
Test.cpp:(.eh_frame+0x6b): undefined reference to `__gxx_personality_v0'
setting -lstdc++
flag after (!) the flag for the library i get "only" these:
Test.cpp:(.text+0x64): undefined reference to `_Unwind_Resume'
Test.cpp:(.eh_frame+0x6b): undefined reference to `__gxx_personality_v0'
This problem looks like a bug in MinGW GCC.
- Using GCC 3.4.5: Error as posted above
- Using GCC 4.7.2: No Error
Also make sure -lstdc++
is the last (!) of your -l
flags.
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