In systemc: FSDB dump fails when simulation is ended with assert statement.

[shaddad]

I have an issue with fsdb dump when simulation in systemc fails using an   assert   statement such as  (assert(a==b) .. etc. 

The signals in the waveform show as  nf  (not found). Any way to fix this issue? 

[Eyck]

The only option is to close your database properly. BTW, this only applies to VCD or transaction recording (e.g. https://github.com/Minres/LWTR4SC). One way to achieve this under Linux would be to use the setjmp/longjmp mechanism:

#include <systemc>
...
#include <csetjmp>
#include <csignal>
  
using namespace sc_core;

jmp_buf abrt;
void ABRThandler(int sig) { longjmp(abrt, 1); }

int sc_main(int argc, char* argv[]) {
    signal(SIGABRT, ABRThandler);
    ///////////////////////////////////////////////////////////////////////////
    // create toplevel, trace, etc
    ///////////////////////////////////////////////////////////////////////////
	...
    ///////////////////////////////////////////////////////////////////////////
    // run the simulation
    ///////////////////////////////////////////////////////////////////////////
    int ret = -1;
    if(setjmp(abrt) == 0) {
        try {
			sc_start();            }
        } catch(sc_report& rep) {
            sc_report_handler::get_handler()(rep, SC_DISPLAY | SC_STOP);
        }
		// make sure end_of_simulation gets invoked
        if(!sc_end_of_simulation_invoked()) {
			sc_stop();
		}
        ret = sc_report_handler::get_count(SC_ERROR) + sc_report_handler::get_count(SC_WARNING);
    } else {
        ret = -1;
    }
    ///////////////////////////////////////////////////////////////////////////
    // close databases, cleanuo
    ///////////////////////////////////////////////////////////////////////////
	...
    ///////////////////////////////////////////////////////////////////////////
    // finish execution returning the number of errors/warnings as exit status
    ///////////////////////////////////////////////////////////////////////////
	return ret;
}

It also reports the number of warnings and errors so that it can be used in CI scenarios or regression testing.

[shaddad]

The vcd file is good and does not have any problem showing signals' values with the sim is ended with   assert. 

We still need a fix for the fsdb (verdi) issue. 

Pls  help if you can!

 

[Eyck]

This is not entirely true, VCD has the same problems only at a different scale. Writing a text file using fwrite usually employs buffering for performance reasons. Stopping a program using abort (called by a failing assert) will not write this buffer to disc. So the content is lost. Depending of the amount a signals being traced and their activiy you might loose the most interesting part of the trace....

On 8/1/2024 at 1:21 AM, shaddad said:

We still need a fix for the fsdb (verdi) issue. 

This cannot be fixed in fsdb, you need to modify your sc_main to allow proper closing of trace database(s).