Visual Studio does not differentiate between C headers and C++ headers

Question

I am work with C language with Visual Studio 2017-enterprise but there is a complex problem with C header files because Visual Studio considers every header is a C++ header. So, whether the extension is .hpp or .h , it will treat it as a C++ header, and this causes problem because I used C99 and Visual Studio will consider the header is C++ so I can't use C features in the header file.

Note : When I name a source file to .c , Visual Studio treats it as a C file, not C++, and it's good. So I need to do the same with headers. I need to make .h for c and .hpp for c++ How?

This problem also with VS 2010, 2013, 2015.

EDIT::

the problem with highlighting for example if i create class in .c file visula studio will say there is error but this will not show any error if i create class in .h file even if i use extern"C"

look At This image : source.h Now Look At This source.c

Answer 1

If you #include a .h file from a .c file then Visual Studio will compile it as C. If you #include a .h file from a .cpp file then Visual Studio will compile it as C++.

It's common to do this in C-specific headers:

#ifdef __cplusplus 
extern "C" {
#endif

void MyCFunction();
void MyCFunction2();

#ifdef __cplusplus 
}
#endif

This allows you to declare functions which are implemented in C. Other C-sources can use these functions, and C++ sources can use these functions.

You don't really need to worry about C++-specific headers because you'll just get compilation errors if you #include them in a C source.

Answer 2

The problem you're having as I understand it is that you are trying to develop C code in vscode, however the editor keeps trying to treat *.h files as C++ files and not C files, fundamentally this is because as far as I can tell MS hates C . I had the same problem, so here is the solution I ended up using:

1. Open the command palette by pressing Ctrl + Shift + P
2. Start typing Preferences: Configure language specific settings
3. Choose C , this will open Settings.json
4. If the key "files.associations" isn't defined, you'll have to define it, and add the "*.h": "c", property in it.

At the end the file should look like this:

{
    //...other settings

    "files.associations": {
        "*.h": "c",
    },

    //...other settings
}

This will set the editor mode to C whenever you open a file ending with a .h . You can define similar settings for all these languages .

Answer 3

"This causes problem because I used C99 and Visual Studio will consider the header is C++ so I can't use C features in the header file."

No, the problem is that Visual Studio does not support C99 anywhere, neither in header files nor in .C files. Visual Studio follows ISO C90.