Usage of static library in C

[bauerwo]

Dear all

I'm a newbie to C, C++, and Visual C++ .Net, so if there is a better place
to ask this question, please let me know.

Using Visual C++ .Net, I haven compiled and linked a static library
"myLib.lib", providing the function "myFunc". I can access it without any
problem in another C++ program "myMain" by writing

extern double myFunc(int N);
pragma comment(lib,"myLib.lib")

But the goal would be to have the calling program be written in C; when I
change the project properties into /TC "Compile as C program", I get

myMain error LNK2019: unresolved external symbol _myFunc referenced in
function _main

What's the right way to include a library into C?

Best regards,

W. Bauer

[David Lowndes]

>Using Visual C++ .Net, I haven compiled and linked a static library

"myLib.lib", providing the function "myFunc". I can access it without any
problem in another C++ program "myMain" by writing

extern double myFunc(int N);
pragma comment(lib,"myLib.lib")

But the goal would be to have the calling program be written in C; when I
change the project properties into /TC "Compile as C program", I get
myMain error LNK2019: unresolved external symbol _myFunc referenced in
function _main

What's the right way to include a library into C?

The library function needs to be defined as "C" linkage - see the help
on extern - "Using extern to Specify Linkage".

Dave
--
MVP VC++ FAQ: http://www.mvps.org/vcfaq

[bauerwo]

David Lowndes <da****@example.invalid> wrote in
news:6m********************************@4ax.com:

The library function needs to be defined as "C" linkage - see the help
on extern - "Using extern to Specify Linkage".

I suppose this is required when a C library is to be used in C++. But I
would like to use in a C program a library that has been written in C++. Is
this possible?

Many thanks, W. Bauer

[bauerwo]

David Lowndes <da****@example.invalid> wrote in
news:6m********************************@4ax.com:

The library function needs to be defined as "C" linkage - see the help
on extern - "Using extern to Specify Linkage".

I suppose this is required when a C library is to be used in C++. But I
would like to use in a C program a library that has been written in C++. Is
this possible?

Many thanks, W. Bauer

[Ronald Laeremans [MSFT]]

Only if it exports C functions or if you are willing to get the C code to
compile as C++ (which in general is quite a realistic effort, even for a
relatively large code base).

Ronald Laeremans
Visual C++ team

"bauerwo gmx.net" <at> wrote in message
news:Xn*****************************@195.186.4.29. ..

David Lowndes <da****@example.invalid> wrote in
news:6m********************************@4ax.com:

The library function needs to be defined as "C" linkage - see the help
on extern - "Using extern to Specify Linkage".

I suppose this is required when a C library is to be used in C++. But I
would like to use in a C program a library that has been written in C++.
Is
this possible?

Many thanks, W. Bauer

[Ronald Laeremans [MSFT]]

Only if it exports C functions or if you are willing to get the C code to
compile as C++ (which in general is quite a realistic effort, even for a
relatively large code base).

Ronald Laeremans
Visual C++ team

"bauerwo gmx.net" <at> wrote in message
news:Xn*****************************@195.186.4.29. ..

David Lowndes <da****@example.invalid> wrote in
news:6m********************************@4ax.com:

The library function needs to be defined as "C" linkage - see the help
on extern - "Using extern to Specify Linkage".

I suppose this is required when a C library is to be used in C++. But I
would like to use in a C program a library that has been written in C++.
Is
this possible?

Many thanks, W. Bauer

[bauerwo]

"Ronald Laeremans [MSFT]" <ro*****@online.microsoft.com> wrote in
news:O5*************@TK2MSFTNGP11.phx.gbl:

Only if it exports C functions or if you are willing to get the C code
to compile as C++ (which in general is quite a realistic effort, even
for a relatively large code base).

Many thanks, now I got it; functions in a dll can be exported and thus be
made accessible by C, super!

Best regards, W. Bauer