[sv-ec] Constraint_mode virtuality

Thre are some ambiguites in LRM according to constrain_mode and inheritance:
1. LRM do not specifies if constraints_mode function is virtual or not.
2. LRM do not specifies if constraint_mode should turn-off constraints in
whole class hierarchy or only in certain constraint
 
Example:
virtual class A;
     rand int x,y;
  constraint c3 { x==50; }
     
  function void post_randomize;
   $display(x);
  endfunction
endclass

class B extends A;
     constraint c3 { x==5; }
endclass

module top;
 B b = new;
     A a;
 initial begin
  a=b;
  a.randomize();//it should randomize 5
  a.c3.constraint_mode(0);
//there are 3 possibilities which one is correct
//B::c3 be turned off and A::c3 be valid
//B::c3 and A::c3 be turned off?
//A::c3 turned off B::c3 valid
  a.randomize();
  a.c3.constraint_mode(1);
  b.randomize();
  b.c3.constraint_mode(0);
//there are 2 possibilities which one is correct
//B::c3 be turned off and A::c3 be valid
//B::c3 and A::c3 be turned off?
  b.randomize();
 end
endmodule

 
Are above known issues?
 
 
 
 
 
DANiel

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