GCC C calls C + +

The road of programming is just beginning, the mistake inevitably, hoped everybody can point out.

Simply record the C file to invoke the CPP file, using the code to illustrate:

1 /*test.h*/2 #ifdef __cplusplus3 extern "C"4 {5 #endif6 intAddintXinty);7 #ifdef __cplusplus8 }9 #endifTen  One  A /*Test.cpp*/ -#include"test.h" -  the intAddintXinty) - { -     returnx+y; - } +  -  + /*main.c*/ A#include <stdio.h> at#include"test.h" -  - intMain () - { -     intD = Add (1,2); -printf"%d\n", d); in  -     return 0; to}

Command line: GCC main.c test.cpp

The only thing you need to know here is the following paragraph:

#ifdef __cplusplus
extern "C" {
#endif

A section of code

#ifdef __cplusplus
}
#endif

__cplusplus is a custom macro in CPP, the meaning of the above code is: if the macro __cplusplus is defined, then this paragraph is the CPP code, so add the extern "C" {and} to process the code in it.

The main purpose of extern "C" is to be able to correctly implement C + + code calls to other C language code. The addition of extern "C" instructs the compiler to compile this part of the code in C instead of C + +. Because C + + supports function overloading, the compiler compiles the function by adding the parameter type of the function to the compiled code, not just the function name, and the C language does not support the functions overloading, so the function of compiling C code does not take the parameter type of the function, generally only includes the function name.

GCC C calls C + +