SystemC 2.3.0 with main()

[knhan930]

Another issue I have is that I have a simple C++ code that uses only SystemC datatypes from SystemC library like below.

#include "systemc.h"


int main() {
 sc_uint<8> a, b;
 sc_uint<9> z;

 z = a + b;
}

It’s working with SystemC 2.2.0, but there is a link error with SystemC 2.3.0. I used the general compile command with GCC 4.2.2:

% g++ -I$SYSTEMC/include test.cpp –L$SYSTEMC/lib-linux64 -lsystemc
…/systemc-2.3.0/lib-linux64/libsystemc.so: undefined reference to `sc_main' collect2: ld returned 1 exit status

I wonder if SystemC 2.3.0 disables to use main() at all, which was ok with SystemC 2.2.0. It may cause the compatibility issue, so I would like to know how to remove the link error. Thank you.

[Philipp A Hartmann]

% g++ -I$SYSTEMC/include test.cpp –L$SYSTEMC/lib-linux64 -lsystemc
…/systemc-2.3.0/lib-linux64/libsystemc.so: undefined reference to `sc_main' collect2: ld returned 1 exit status

If you look at the error message more closely, the problem is not caused by the existence of your "main" function, but by the missing sc_main function. The main reason for this is the preferred use of the dynamic library since SystemC 2.3.0. The dynamic libraries needs the sc_main symbol to be present, as you cannot decide during the (dynamic) linking step, if this function is actually called or not.

I wonder if SystemC 2.3.0 disables to use main() at all, which was ok with SystemC 2.2.0. It may cause the compatibility issue, so I would like to know how to remove the link error. Thank you.

Two solutions are possible

• link against the static library libsystemc.a (e.g. by moving libsystemc.so out of the way)
  
• add an (empty) sc_main
  

Greetings from Oldenburg,

Philipp

[knhan930]

Thank you. It's helpful.

[taog]

I've tried link against the static library libsystemc.a, I got error below:

/home/taog/tools/systemc-2.3.1/lib-linux64//libsystemc.a(sc_main_main.o): In function `sc_elab_and_sim':
/home/taog/tools_src/systemc-2.3.1a/objdir/src/sysc/kernel/../../../../src/sysc/kernel/sc_main_main.cpp:84: undefined reference to `sc_main'
I need to pack a library based on SystemC, adding a empty sc_main in a library is weld.

[maehne]

37 minutes ago, taog said:

I've tried link against the static library libsystemc.a, I got error below:

/home/taog/tools/systemc-2.3.1/lib-linux64//libsystemc.a(sc_main_main.o): In function `sc_elab_and_sim':
/home/taog/tools_src/systemc-2.3.1a/objdir/src/sysc/kernel/../../../../src/sysc/kernel/sc_main_main.cpp:84: undefined reference to `sc_main'
I need to pack a library based on SystemC, adding a empty sc_main in a library is weld.

Either you as the library author or the user of that library will need to provide at least an empty implementation of sc_main() to satisfy the linker. There is no way around it. I would like to also suggest that you update your SystemC installation to the latest version 2.3.3.

[taog]

11 hours ago, maehne said:

Either you as the library author or the user of that library will need to provide at least an empty implementation of sc_main() to satisfy the linker. There is no way around it. I would like to also suggest that you update your SystemC installation to the latest version 2.3.3.

Get it, thank you, maehne.