gcc 和 g++

朱雀 2022-03-22 06:40 461阅读 0赞

## 用gcc 编译链接cpp源码 ##

先给出源码及编译链接结果：

me.h：

extern "C" void CppPrintf(void);

me.cpp:

#include 
    #include "me.h"
    using namespace std;
    void CppPrintf(void)
    {
         cout << "Hello\n";
    }

test.cpp:

#include "me.h"        
    int main(void)
    {
        CppPrintf();
        return 0;
    }

g++:

g++  test.cpp me.cpp -o test
    g++  -g -Wall -std=c++11 test.cpp me.cpp -o test

gcc:

gcc -g -Wall -std=c++11 test.cpp me.cpp -o test -lstdc++
    gcc -g -Wall -std=c++11 test.cpp me.cpp -o test -lstdc++ -shared-libgcc

注意，下面的是行不通的(-lstdc++ -shared-libgcc一定要放后面)

gcc -g -Wall -std=c++11 -lstdc++ -shared-libgcc test.cpp me.cpp -o test

## 说明关系 ##

平时使用gcc/g++，看了网上的一些回答和gcc的关系，感觉很多不太准确，或者缺少例子，就记录一下。stackoverflow上大致意思是，  
`g++ ` <<=等价于=>>  `gcc -xc++  -lstdc++  -shared-libgcc` (the 1st is a compiler option, the 2nd two are linker options)

有一哥列出了下面这些区别，

The main differences:  
1.gcc will compile: \*.c/\*.cpp files as C and C++ respectively.  
2.g++ will compile: \*.c/\*.cpp files but they will all be treated as C++ files.  
3.Also if you use g++ to link the object files it automatically links in the std C++ libraries (gcc does not do this).  
4.gcc compiling C files has fewer predefined macros.  
5.gcc compiling \*.cpp and g++ compiling \*.c/\*.cpp files has a few extra macros.

Extra Macros when compiling \*.cpp files:

#define __GXX_WEAK__ 1
    #define __cplusplus 1
    #define __DEPRECATED 1
    #define __GNUG__ 4
    #define __EXCEPTIONS 1
    #define __private_extern__ extern

但我没找到官方的出处。

参考：  
[https://stackoverflow.com/questions/172587/what-is-the-difference-between-g-and-gcc][https_stackoverflow.com_questions_172587_what-is-the-difference-between-g-and-gcc]

官方文档中提到g++也没明确说明，只在第3.3节说明对C++文件应该使用g++，参考：  
[https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc.pdf][https_gcc.gnu.org_onlinedocs_gcc-8.2.0_gcc.pdf]

## 其他参考 ##

[https://blog.csdn.net/bit\_clearoff/article/details/53965514][https_blog.csdn.net_bit_clearoff_article_details_53965514]

[https_stackoverflow.com_questions_172587_what-is-the-difference-between-g-and-gcc]: https://stackoverflow.com/questions/172587/what-is-the-difference-between-g-and-gcc
[https_gcc.gnu.org_onlinedocs_gcc-8.2.0_gcc.pdf]: https://gcc.gnu.org/onlinedocs/gcc-8.2.0/gcc.pdf
[https_blog.csdn.net_bit_clearoff_article_details_53965514]: https://blog.csdn.net/bit_clearoff/article/details/53965514