module test; typedef struct packed { logic [9:-1][2:0] a; ///REQ-EXT-10001, REQ-EXT-10004 } ST1; typedef struct { ST1 st1; ST1 st2[]; logic [7:0] b; //REQ-EXT-10002; }ST4 initial begin ST4 st4; st4.st1.a[0][0]=1; for (int i=0; i<5; i++) begin st4.st1.push_back(i+1); end st4_1.b = 8'hAA; $display("%", st2); //CHECK-001:'{a:'h1}, st2:'{'a:'h1}, '{a:'h0},'{a:h1}}} end endmodule when compiled by vcs, it reports 3 errors, the errors are: Error-[MFNF] Member not found sc_assignment_pattern_030.sv,29 "st4.st1." Could not find member 'push_back' in structure 'ST1', at "sc_assignment_pattern_030.sv",15. Error-[XMRE] Cross-module reference resolution error sc_assignment_pattern_030.sv,31 Error found while trying to resolve cross-module reference.token 'st4_1'. Originating module 'test'. Source info:st4_1.b = 8'haa; Error-[IND] Identifier 'st2' has not been declared yet. If this error is not expected, please check if you have set 'default_nettype to none. How should I fix these 3 errors so that this piece of system verilog code can be compiled succeessfully by vcs? thanks a lot

Based on the code snippet provided, there are three errors that need to be fixed:

1. "Could not find member 'push_back' in structure 'ST1'"
This error occurs because 'push_back' is not a member of 'ST1'. It is actually a member of an array of 'ST1' structures. To fix this error, you need to change the code to create an array of 'ST1' structures and then call 'push_back' on the array instead of 'ST1':

ST4 st4;
st4.st1.a[0][0]=1;
for (int i=0; i<5; i++) begin
   ST1 tmp;
   tmp.a[0][0] = i+1;
   st4.st2.push_back(tmp);
end

2. "Error found while trying to resolve cross-module reference.token 'st4_1'"
This error occurs because 'st4_1' is not declared anywhere in the code. To fix this error, you need to change the code to use 'st4' instead of 'st4_1':

ST4 st4;
st4.st1.a[0][0]=1;
for (int i=0; i<5; i++) begin
   ST1 tmp;
   tmp.a[0][0] = i+1;
   st4.st2.push_back(tmp);
end
st4.b = 8'hAA;
$display("%", st4.st2); //CHECK-001:'{a:'h1}, st2:'{'a:'h1}, '{a:'h0},'{a:h1}}}

3. "Identifier 'st2' has not been declared yet"
This error occurs because 'st2' is not declared anywhere in the code. To fix this error, you need to change the code to use 'st4.st2' instead of 'st2':

ST4 st4;
st4.st1.a[0][0]=1;
for (int i=0; i<5; i++) begin
   ST1 tmp;
   tmp.a[0][0] = i+1;
   st4.st2.push_back(tmp);
end
st4.b = 8'hAA;
$display("%", st4.st2); //CHECK-001:'{a:'h1}, st2:'{'a:'h1}, '{a:'h0},'{a:h1}}}