c++工程中如何加入c文件？

[delinpeng]

...is not a precompiled header file created with this compiler

我在一个mfc的工程里想加入一些别人写好的c文件，可编译时会出现上面描述的错误

[delinpeng]

还有谁发表意见？

[esc123]

在你需要引用该C文件的头文件的地方加入
extern "C"
{
#include "头文件";
}
试试！

[ruihuahan]

只加入源码（.h、.cpp），不要加入其它编译器产生的任何东西。应该没有问题，C++是C的超集嘛。

[qing_li73]

Just paste a snippet from MSDN ,u can find more by yourself :

Linkage Specifications
The term “linkage specification” refers to the protocol for linking functions (or procedures) written in different languages. The following calling conventions are affected:

Case sensitivity of names.


Decoration of names. In C, the compiler prefixes names with an underscore. This is often called “decoration.” In C++, name decoration is used to retain type information through the linkage phase. (SeeDecorated Names, in Visual C++ Programmer’s Guide.)


Order in which arguments are expected on the stack.


Responsibility for adjusting the stack on function return. Either the called function or the calling function is responsible.


Passing of hidden arguments (whether any hidden arguments are passed).
Syntax

linkage-specification :

extern string-literal { declaration-listopt }
extern string-literal declaration

declaration-list :

declaration
declaration-list

Linkage specification facilitates gradually porting C code to C++ by allowing the use of existing code.

Microsoft Specific

The only linkage specifications currently supported by Microsoft C++ are "C" and "C++".

END Microsoft Specific

The following example declares the functions atoi and atol with C linkage:

extern "C"
{
int atoi( char *string );
long atol( char *string );
}

Calls to these functions are made using C linkage. The same result could be achieved with these two declarations:

extern "C" int atoi( char *string );
extern "C" long atol( char *string );

Microsoft Specific

All Microsoft C standard include files use conditional compilation directives to detect C++ compilation. When a C++ compilation is detected, the prototypes are enclosed in an extern "C" directive as follows:

// Sample.h
#if defined(__cplusplus)
extern "C"
{
#endif

// Function declarations

#if defined(__cplusplus)
}
#endif

END Microsoft Specific

You do not need to declare the functions in the standard include files as extern "C".

If a function is overloaded, no more than one of the functions of the same name can have a linkage specifier. (For more information, see Function Overloading in Chapter 7.)

Table 6.3 shows how various linkage specifications work.

Table 6.3 Effects of Linkage Specifications

Specification Effect
On an object Affects linkage of that object only
On a function Affects linkage of that function and all functions or objects declared within it
On a class Affects linkage of all nonmember functions and objects declared within the class


If a function has more than one linkage specification, they must agree; it is an error to declare functions as having both C and C++ linkage. Furthermore, if two declarations for a function occur in a program — one with a linkage specification and one without — the declaration with the linkage specification must be first. Any redundant declarations of functions that already have linkage specification are given the linkage specified in the first declaration. For example:

extern "C" int CFunc1();
...
int CFunc1(); // Redeclaration is benign; C linkage is
// retained.

int CFunc2();
...
extern "C" int CFunc2(); // Error: not the first declaration of
// CFunc2; cannot contain linkage
// specifier.

Functions and objects explicitly declared as static within the body of a compound linkage specifier ({ }) are treated as static functions or objects; the linkage specifier is ignored. Other functions and objects behave as if declared using the extern keyword. (See Storage-Class Specifiers for details about the extern keyword.)

[delinpeng]

问题在于别人的文件是.c文件，我原来以为将文件名改为.cpp就可以了，没想到还是报错。
听同事讲是在某个地方写上一句 extern "c++"，可我就是试不对

[studentforever]

project,settings,c++标签中，选中precompiled headers,选中not using precompiled headers

[archoo]

c函数编译出来的代码和C++不同；

你将整个.c文件中的所有函数都用
extern "C" {
...
}
应该就可以了；

[zhou80bin]

up

[delinpeng]

qing_li73(bluemoon) :谢谢提醒，我的英文水平不行，平时很少看msdn，看来是该补补课了。
studentforever：不行，这样做又会出现其他的错误。
archoo(archoo) ：不行，如果我将该c文件所有行都删掉，依然会出现这个错误。
谢谢楼上诸位的发言。

[delinpeng]

我最终是做成了lib文件。
大家对此问题还有没有其他的想法？
要不我只有结贴了。