Error when initiating a transaction indirectly from a C source file

[davidbp13]

Hi,

I'm implemented a small virtual prototype using SystemC. The CPU model of my system is very simple and only has a function read and a function to write to a memory mapped address. I need to be able to call this functions from a C file, not a C++ file. Hoewver, when trying to do this and compile everything together I get an error: 

/cad/gnu/gcc/systemc-2.3.1/include/sysc/packages/boost/config/select_stdlib_config.hpp:20:19: fatal error: utility: No such file or directory
 #include <utility>
                   ^
compilation terminated.
make[2]: *** [prj/CMakeFiles/mpslvp.x.dir/src/mpslvp/c_test.c.o] Error 1
make[1]: *** [prj/CMakeFiles/mpslvp.x.dir/all] Error 2
make: *** [all] Error 2

The problem has to do with the fact that my C file includes the header file of the CPU module which of course includes the systemc library. When removing the systemc dependencies, the code compiles. Is it possible to have a C file implementing functions that indirectly start a SystemC transaction? Hope I explained myself. Thanks in advance!

[David Black]

You cannot compile C++ under a C compiler and SystemC is C++. You will need to create an extern "C" wrapper and you will need to deal with maintaining objects.

This is really a C++ issue and you should probably read <https://isocpp.org/wiki/faq/mixing-c-and-cpp>.

[davidbp13]

Thanks for your reply David! So using g++ to compile instead of gcc may fix my issue? If so, do I still need extern C wrappers when using a c++ compiler? Also, how much of a straight forward solution is moving my c files to cpp files only? Thansk! 

[Bas Arts]

If you separate application code and read/write implementation code, you can keep your C code application and compile it still for your CPU module. Yes, you will need a C++ compiler then, but it also allows you to port your application to e.g. a commercial CPU model which could use plain C. You'd only need to replace your read/write C++ implementation with a C implementation.
 

// C header file
#ifndef C_H
#define C_H
#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */
void mywrite(uint32_t address, uint32_t value);
void myread (uint32_t address, uint32_t *value);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* C_H */