Make vvp exit with FAILURE if $fatal is used to exit the simulation.

vpi/sys_display.c

@@ -2161,6 +2161,9 @@ static PLI_INT32 sys_severity_calltf(ICARUS_VPI_CONST PLI_BYTE8*name)
       free(dstr);
 
       if (strncmp(name,"$fatal",6) == 0) {
+	      /* Set the exit code from vvp as an error code. */
+	    vpip_set_return_value(1);
+	      /* Now tell the simulator to finish. */
             vpi_control(vpiFinish, finish_number.value.integer);
       }
 

vpi/sys_finish.c

@@ -42,6 +42,8 @@ static PLI_INT32 sys_finish_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name)
 	    return 0;
       }
 
+      vpip_set_return_value(0);
+
       vpi_control(vpiFinish, diag_msg);
       return 0;
 }

vpi_user.h

@@ -630,7 +630,14 @@ extern DLLEXPORT void (*vlog_startup_routines[])(void);
   /* Format a scalar a la %v. The str points to a 4byte character
      buffer. The value must be a vpiStrengthVal. */
 extern void vpip_format_strength(char*str, s_vpi_value*value, unsigned bit);
+  /* Set the return value to return from the vvp run time. This is
+     usually 0 or 1. This is the exit code that the vvp process
+     returns, and in distinct from the finish_number that is an
+     argument to $fatal and other severity tasks. The $fatal and
+     $finish system tasks bundled with iverilog use this function to
+     tell vvp to exit SUCCESS or FAILURE. */
 extern void vpip_set_return_value(int value);
+
 extern s_vpi_vecval vpip_calc_clog2(vpiHandle arg);
 extern void vpip_make_systf_system_defined(vpiHandle ref);
 

vvp/stop.cc

@@ -535,7 +535,7 @@ void stop_handler(int rc)
         /* The user may be running in a non-interactive environment, so
          * they want $stop and <Control-C> to be the same as $finish. */
       if (stop_is_finish) {
-           vpip_set_return_value(stop_is_finish_exit_code);
+	    vpip_set_return_value(stop_is_finish_exit_code);
 	    schedule_finish(0);
 	    return;
       }