compiling c program with C++ program

[sothy]

Hello,
I have C++ progam that compiles and running well. Now I need to test one feature with c program.

In c program, I am writing one client_wrapper.h and client_wrapper.c file.
In the client_wrapper.h file.

#ifdef __cplusplus
extern "C" {
#endif 

char* get_msg()

#ifdef __cplusplus
}
#endif

In c file, without any decoration, I implement logic in client_wrapper.c fie.

In my cpp program, I wrote at the begining,

extern "C" {
char* get_msg()
}

..........in the code I called get_msg().

...............

now I'm facing linking problem. Compilion went well and linking is not working.
Why? where is problem. I am g++ 5.4.0.

Thanks
Sothy

[stahta01]

Why did you not post the link error?

Tim S.

[sothy]

error msg

[
1/1] LINK (stripped) build/release/sx_main_server
FAILED: g++  -O2 `pkg-config --cflags --libs /home/sothy/seastar/build/release/seastar.pc`   -g -Wl,--no-as-needed   -fvisibility=hidden  -pthread -lstdc++  -o  build/release/sx_main_server build/sx_main_server.o   
build/sx_main_server.o: In function `udp_server::start(unsigned short)::{lambda()#2}::operator()() const::{lambda(seastar::net::udp_datagram)#1}::operator()(seastar::net) const':
/home/sothy/seastar/apps/udpd/udp_server.hh:72: undefined reference to `get_msg'
collect2: error: ld returned 1 exit status

ninja: build stopped: subcommand failed.

[stahta01]

Any reason you are not linking to client_wrapper.o because that is what is likely causing the error?

Tim S.