Re: c++ calling c functions

From:

Abhishek Padmanabh <abhishek.padmanabh@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 4 Dec 2007 21:36:46 -0800 (PST)

Message-ID:

<39385aa0-5244-4b32-8389-8e61e6a43b4d@e23g2000prf.googlegroups.com>

On Dec 5, 9:25 am, Uday Bidkar <uday.bid...@gmail.com> wrote:

On Dec 5, 9:18 am, teju <tejaswini_ra...@yahoo.co.in> wrote:

i am trying 2 merge 2 projects into one project.One project is using c
language and the other one is using c++ code.

both are working very fine independently.But now i need to merge both
and my c++ code should call c code.but when i tried to call a function
in c code externing that function in my c++ code, i am getting
unresolved external symbol error. Whatever i try its giving more and
more errrors...so is it possible to merge 2 projects?

if so how can i do that?

I guess the problem is because of c++ compiler mangling the names of
the functions. Have you declared the C functions as extern "C" in the C
++ code you are using? If not, try doing so.

Is the extern "C" needed if the code is merged and built with a C++
compiler? I don't think mangling should be an issue as long as the C-
project is also being built as C++. If there are C libraries that are
being used in the C project, it would be needed to put extern
declaration to interface with them.

A C project merged into a C++ project is same as a C++ project that
has been written with a subset of C++ (that is close to C).