Fix dynamic array assignment to make a copy of the rvalue.

IEEE Std 1800-2017 Section 7.6 Array assignments

Assignment of a dynamic array creates a duplicate of the source,
so that assignments to the copy don't impact the original. Handle
all sorts of dynamic array base types.

PFunction.cc

@@ -43,7 +43,7 @@ void PFunction::set_statement(Statement*s)
 
 void PFunction::push_statement_front(Statement*stmt)
 {
-	// This can only happen after the statement is initially set.
+        // This should not be possible.
       ivl_assert(*this, statement_);
 
 	// Get the PBlock of the statement. If it is not a PBlock,
@@ -75,7 +75,8 @@ PChainConstructor* PFunction::extract_chain_constructor()
       PChainConstructor*res = 0;
 
       if ((res = dynamic_cast<PChainConstructor*> (statement_))) {
-	    statement_ = 0;
+	    statement_ = new PBlock(PBlock::BL_SEQ);
+	    statement_->set_line(*this);
 
       } else if (PBlock*blk = dynamic_cast<PBlock*>(statement_)) {
 	    res = blk->extract_chain_constructor();

elab_expr.cc

@@ -1958,6 +1958,7 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
       unsigned long use_width = struct_type->packed_width();
 
       pform_name_t completed_path;
+      ivl_type_t member_type = 0;
       do {
 	    const name_component_t member_comp = member_path.front();
 	    const perm_string&member_name = member_comp.name;
@@ -1985,28 +1986,29 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
 		  des->errors += 1;
 		  return 0;
 	    }
+	    member_type = member->net_type;
 	    if (debug_elaborate) {
 		  cerr << li->get_fileline() << ": check_for_struct_members: "
-		       << "Member type: " << *(member->net_type)
-		       << " (" << typeid(*(member->net_type)).name() << ")"
+		       << "Member type: " << *member_type
+		       << " (" << typeid(*member_type).name() << ")"
 		       << endl;
 	    }
 
 	    off += tmp_off;
-	    ivl_assert(*li, use_width >= (unsigned long)member->net_type->packed_width());
-	    use_width = member->net_type->packed_width();
+	    ivl_assert(*li, use_width >= (unsigned long)member_type->packed_width());
+	    use_width = member_type->packed_width();
 
 	      // At this point, off and use_width are the part select
 	      // expressed by the member_comp, which is a member of the
 	      // struct. We can further refine the part select with any
 	      // indices that might be present.
 
-	    if (const netstruct_t*tmp_struct = dynamic_cast<const netstruct_t*>(member->net_type)) {
+	    if (const netstruct_t*tmp_struct = dynamic_cast<const netstruct_t*>(member_type)) {
 		    // If the member is itself a struct, then get
 		    // ready to go on to the next iteration.
 		  struct_type = tmp_struct;
 
-	    } else if (const netenum_t*tmp_enum = dynamic_cast<const netenum_t*> (member->net_type)) {
+	    } else if (const netenum_t*tmp_enum = dynamic_cast<const netenum_t*> (member_type)) {
 
 		    // If the element is an enum, then we don't have
 		    // anything special to do.
@@ -2017,7 +2019,7 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
 		  }
 		  struct_type = 0;
 
-	    } else if (const netvector_t*mem_vec = dynamic_cast<const netvector_t*>(member->net_type)) {
+	    } else if (const netvector_t*mem_vec = dynamic_cast<const netvector_t*>(member_type)) {
 
 		  if (debug_elaborate) {
 			cerr << li->get_fileline() << ": check_for_struct_members: "
@@ -2104,7 +2106,7 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
 		    // there is no next struct type.
 		  struct_type = 0;
 
-	    } else if (const netparray_t*array = dynamic_cast<const netparray_t*>(member->net_type)) {
+	    } else if (const netparray_t*array = dynamic_cast<const netparray_t*>(member_type)) {
 
 		    // If the member is a parray, then the elements
 		    // are themselves packed object, including
@@ -2178,7 +2180,7 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
 	    } else {
 		    // Unknown type?
 		  cerr << li->get_fileline() << ": internal error: "
-		       << "Unexpected member type? " << *(member->net_type)
+		       << "Unexpected member type? " << *member_type
 		       << endl;
 		  des->errors += 1;
 		  struct_type = 0;
@@ -2224,7 +2226,7 @@ static NetExpr* check_for_struct_members(const LineInfo*li,
 
       NetESignal*sig = new NetESignal(net);
       NetExpr   *base = packed_base? packed_base : make_const_val(off);
-      NetESelect*sel = new NetESelect(sig, base, use_width);
+      NetESelect*sel = new NetESelect(sig, base, use_width, member_type);
 
       if (debug_elaborate) {
 	    cerr << li->get_fileline() << ": check_for_struct_member: "
@@ -2599,7 +2601,7 @@ NetExpr* PECallFunction::elaborate_expr_method_(Design*des, NetScope*scope,
 	/* Add the implicit this reference when requested. */
       if (add_this_flag) {
 	    assert(use_path.empty());
-	    use_path.push_front(name_component_t(perm_string::literal("@")));
+	    use_path.push_front(name_component_t(perm_string::literal(THIS_TOKEN)));
       }
 
 	// If there is no object to the left of the method name, then
@@ -3904,7 +3906,7 @@ NetExpr* PEIdent::elaborate_expr_class_member_(Design*des, NetScope*scope,
       NetScope*scope_method = find_method_containing_scope(*this, scope);
       ivl_assert(*this, scope_method);
 
-      NetNet*this_net = scope_method->find_signal(perm_string::literal("@"));
+      NetNet*this_net = scope_method->find_signal(perm_string::literal(THIS_TOKEN));
       if (this_net == 0) {
 	    cerr << get_fileline() << ": internal error: "
 		 << "Unable to find 'this' port of " << scope_path(scope_method)
@@ -5395,7 +5397,7 @@ NetExpr* PEIdent::elaborate_expr_net_bit_(Design*des, NetScope*scope,
 		  cerr << get_fileline() << ": debug: "
 		       << "Bit select of a dynamic array becomes NetESelect." << endl;
 	    }
-	    NetESelect*res = new NetESelect(net, mux, darray->element_width());
+	    NetESelect*res = new NetESelect(net, mux, darray->element_width(), darray->element_type());
 	    res->set_line(*net);
 	    return res;
       }
@@ -5597,13 +5599,15 @@ NetExpr* PEIdent::elaborate_expr_net_bit_last_(Design*, NetScope*,
       }
 
       unsigned use_width = 1;
+      ivl_type_t use_type = 0;
       if (const netdarray_t*darray = net->sig()->darray_type()) {
 	    use_width = darray->element_width();
+	    use_type = darray->element_type();
       }
 
       NetELast*mux = new NetELast(net->sig());
       mux->set_line(*this);
-      NetESelect*ss = new NetESelect(net, mux, use_width);
+      NetESelect*ss = new NetESelect(net, mux, use_width, use_type);
       ss->set_line(*this);
       return ss;
 }
@@ -5762,7 +5766,7 @@ NetExpr* PENewClass::elaborate_expr_constructor_(Design*des, NetScope*scope,
 
 	      // The return value of the initializer is the "this"
 	      // variable, instead of the "new&" scope name.
-	    NetNet*res1 = new1_scope->find_signal(perm_string::literal("@"));
+	    NetNet*res1 = new1_scope->find_signal(perm_string::literal(THIS_TOKEN));
 	    ivl_assert(*this, res1);
 
 	    NetESignal*eres = new NetESignal(res1);
@@ -5849,7 +5853,7 @@ NetExpr* PENewClass::elaborate_expr_constructor_(Design*des, NetScope*scope,
 
 	// The return value for the constructor is actually the "this"
 	// variable, instead of the "new" scope name.
-      NetNet*res = new_scope->find_signal(perm_string::literal("@"));
+      NetNet*res = new_scope->find_signal(perm_string::literal(THIS_TOKEN));
       ivl_assert(*this, res);
 
       NetESignal*eres = new NetESignal(res);

elab_lval.cc

@@ -378,7 +378,7 @@ NetAssign_* PEIdent::elaborate_lval_method_class_member_(Design*des,
       NetScope*scope_method = find_method_containing_scope(*this, scope);
       ivl_assert(*this, scope_method);
 
-      NetNet*this_net = scope_method->find_signal(perm_string::literal("@"));
+      NetNet*this_net = scope_method->find_signal(perm_string::literal(THIS_TOKEN));
       if (this_net == 0) {
 	    cerr << get_fileline() << ": internal error: "
 		 << "Unable to find 'this' port of " << scope_path(scope_method)

elab_scope.cc

@@ -966,7 +966,11 @@ bool PGenerate::generate_scope_loop_(Design*des, NetScope*container)
 	      // block. Code within this scope thus has access to the
 	      // genvar as a constant.
 	    {
-		  verinum genvar_verinum(genvar);
+		  verinum genvar_verinum;
+		  if (gn_strict_expr_width_flag)
+			genvar_verinum = verinum(genvar, integer_width);
+		  else
+			genvar_verinum = verinum(genvar);
 		  genvar_verinum.has_sign(true);
 		  NetEConstParam*gp = new NetEConstParam(scope,
 							 loop_index,

elab_sig.cc

@@ -578,10 +578,10 @@ void PFunction::elaborate_sig(Design*des, NetScope*scope) const
 	      // source code for the definition may be:
 	      //   function new(...);
 	      //   endfunction
-	      // In this case, the "@" port is the synthetic "this"
-	      // argument and we also use it as a return value at the
-	      // same time.
-	    ret_sig = scope->find_signal(perm_string::literal("@"));
+	      // In this case, the "@" port (THIS_TOKEN) is the synthetic
+	      // "this" argument and we also use it as a return value at
+	      // the same time.
+	    ret_sig = scope->find_signal(perm_string::literal(THIS_TOKEN));
 	    ivl_assert(*this, ret_sig);
 
 	    if (debug_elaborate)

elaborate.cc

@@ -110,6 +110,18 @@ void PGAssign::elaborate(Design*des, NetScope*scope) const
 	    return;
       }
 
+      if (lval->enumeration()) {
+	    if (! rval_expr->enumeration()) {
+		  cerr << get_fileline() << ": error: "
+		          "This assignment requires an explicit cast." << endl;
+		  des->errors += 1;
+	    } else if (! lval->enumeration()->matches(rval_expr->enumeration())) {
+		  cerr << get_fileline() << ": error: "
+		          "Enumeration type mismatch in assignment." << endl;
+		  des->errors += 1;
+	    }
+      }
+
       NetNet*rval = rval_expr->synthesize(des, scope, rval_expr);
 
       if (rval == 0) {
@@ -2990,6 +3002,25 @@ NetProc* PBlock::elaborate(Design*des, NetScope*scope) const
 
       for (unsigned idx = 0 ;  idx < list_.size() ;  idx += 1) {
 	    assert(list_[idx]);
+
+	      // Detect the error that a super.new() statement is in the
+	      // midst of a block. Report the error. Continue on with the
+	      // elaboration so that other errors might be found.
+	    if (PChainConstructor*supernew = dynamic_cast<PChainConstructor*> (list_[idx])) {
+	          if (debug_elaborate) {
+		        cerr << get_fileline() << ": PBlock::elaborate: "
+			     << "Found super.new statement, idx=" << idx << ", "
+			     << " at " << supernew->get_fileline() << "."
+			     << endl;
+		  }
+		  if (idx > 0) {
+		        des->errors += 1;
+			cerr << supernew->get_fileline() << ": error: "
+			     << "super.new(...) must be the first statement in a block."
+			     << endl;
+		  }
+	    }
+
 	    NetProc*tmp = list_[idx]->elaborate(des, nscope);
 	      // If the statement fails to elaborate, then simply
 	      // ignore it. Presumably, the elaborate for the
@@ -3254,7 +3285,7 @@ NetProc* PChainConstructor::elaborate(Design*des, NetScope*scope) const
 
 	// Need the "this" variable for the current constructor. We're
 	// going to pass this to the chained constructor.
-      NetNet*var_this = scope->find_signal(perm_string::literal("@"));
+      NetNet*var_this = scope->find_signal(perm_string::literal(THIS_TOKEN));
 
 	// If super.new is an implicit constructor, then there are no
 	// arguments (other than "this" to worry about, so make a
@@ -3716,7 +3747,7 @@ NetProc* PCallTask::elaborate_method_(Design*des, NetScope*scope,
 	/* Add the implicit this reference when requested. */
       if (add_this_flag) {
 	    assert(use_path.empty());
-	    use_path.push_front(name_component_t(perm_string::literal("@")));
+	    use_path.push_front(name_component_t(perm_string::literal(THIS_TOKEN)));
       }
 
 	// There is no signal to search for so this cannot be a method.

ivlpp/lexor.lex

@@ -154,9 +154,9 @@ static void ifdef_leave(void)
         result = (rc == 0) ? YY_NULL : rc;                              \
     } else {                                                            \
         /* We are expanding a macro. Handle the SV `` delimiter.        \
-           If the delimiter terminates a compiler directive, leave      \
+           If the delimiter terminates a defined macro usage, leave     \
            it in place, otherwise remove it now. */                     \
-        if (yytext[0] != '`') {                                         \
+        if (!(yytext[0] == '`' && is_defined(yytext+1))) {              \
             while ((istack->str[0] == '`') &&                           \
                    (istack->str[1] == '`')) {                           \
                 istack->str += 2;                                       \
@@ -186,9 +186,11 @@ static int ma_parenthesis_level = 0;
 
 %x PPINCLUDE
 %x DEF_NAME
+%x DEF_ESC
 %x DEF_ARG
 %x DEF_SEP
 %x DEF_TXT
+%x MN_ESC
 %x MA_START
 %x MA_ADD
 %x CCOMMENT
@@ -338,6 +340,11 @@ keywords (include|define|undef|ifdef|ifndef|else|elseif|endif)
 <DEF_NAME>[a-zA-Z_][a-zA-Z0-9_$]*"("{W}? { BEGIN(DEF_ARG); def_start(); }
 <DEF_NAME>[a-zA-Z_][a-zA-Z0-9_$]*{W}?    { BEGIN(DEF_TXT); def_start(); }
 
+<DEF_NAME>\\ { BEGIN(DEF_ESC); }
+
+<DEF_ESC>[^ \t\b\f\n\r]+{W}"("{W}? { BEGIN(DEF_ARG); def_start(); }
+<DEF_ESC>[^ \t\b\f\n\r]+{W}        { BEGIN(DEF_TXT); def_start(); }
+
   /* define arg: <name> = <text> */
 <DEF_ARG>[a-zA-Z_][a-zA-Z0-9_$]*{W}*"="[^,\)]*{W}? { BEGIN(DEF_SEP); def_add_arg(); }
   /* define arg: <name> */
@@ -352,7 +359,7 @@ keywords (include|define|undef|ifdef|ifndef|else|elseif|endif)
 
 <DEF_ARG,DEF_SEP>(\n|"\r\n"|"\n\r"|\r){W}? { istack->lineno += 1; fputc('\n', yyout); }
 
-<DEF_NAME,DEF_ARG,DEF_SEP>. {
+<DEF_NAME,DEF_ESC,DEF_ARG,DEF_SEP>. {
     emit_pathline(istack);
     fprintf(stderr, "error: malformed `define directive.\n");
     error_count += 1;
@@ -535,6 +542,24 @@ keywords (include|define|undef|ifdef|ifndef|else|elseif|endif)
         do_expand(0);
 }
 
+`\\ { yy_push_state(MN_ESC); }
+
+<MN_ESC>[^ \t\b\f\n\r]+ {
+    yy_pop_state();
+    if (macro_needs_args(yytext))
+        yy_push_state(MA_START);
+    else
+        do_expand(0);
+}
+
+<MN_ESC>. {
+    yy_pop_state();
+    unput(yytext[0]);
+    emit_pathline(istack);
+    fprintf(stderr, "error: malformed macro name.\n");
+    error_count += 1;
+}
+
   /* Stringified version of macro expansion. This is an Icarus extension.
      When expanding macro text, the SV usage of `` takes precedence. */
 ``[a-zA-Z_][a-zA-Z0-9_$]* {
@@ -825,8 +850,13 @@ static void def_add_arg(void)
 
       /* This can happen because we are also processing "argv[0]", the
 	 macro name, as a pseudo-argument. The lexor will match that
-	 as name(, so chop off the ( here. */
-    if (yytext[length -  1] == '(') length--;
+	 as name(, so chop off the ( here. If we have an escaped name,
+	 we also need to strip off the white space that terminates the
+	 name. */
+    if (yytext[length -  1] == '(') {
+	length--;
+	while (isspace((int)yytext[length - 1])) length--;
+    }
 
     yytext[length] = 0;
 

net_expr.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002-2019 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2002-2020 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -403,7 +403,14 @@ ivl_variable_type_t NetEProperty::expr_type() const
 
 NetESelect::NetESelect(NetExpr*exp, NetExpr*base, unsigned wid,
                        ivl_select_type_t sel_type)
-: expr_(exp), base_(base), sel_type_(sel_type)
+: expr_(exp), base_(base), use_type_(0), sel_type_(sel_type)
+{
+      expr_width(wid);
+}
+
+NetESelect::NetESelect(NetExpr*exp, NetExpr*base, unsigned wid,
+                       ivl_type_t use_type)
+: expr_(exp), base_(base), use_type_(use_type), sel_type_(IVL_SEL_OTHER)
 {
       expr_width(wid);
 }
@@ -431,6 +438,9 @@ ivl_select_type_t NetESelect::select_type() const
 
 ivl_variable_type_t NetESelect::expr_type() const
 {
+      if (use_type_)
+	    return use_type_->base_type();
+
       ivl_variable_type_t type = expr_->expr_type();
 
 	// Special case: If the sub-expression is an IVL_VT_STRING,
@@ -439,20 +449,12 @@ ivl_variable_type_t NetESelect::expr_type() const
       if (type == IVL_VT_STRING && expr_width()==8)
 	    return IVL_VT_BOOL;
 
-      if (type != IVL_VT_DARRAY)
-	    return type;
+      return type;
+}
 
-      ivl_assert(*this, type == IVL_VT_DARRAY);
-
-	// Special case: If the expression is a DARRAY, then the
-	// sub-expression must be a NetESignal and the type of the
-	// NetESelect expression is the element type of the arrayed signal.
-      NetESignal*sig = dynamic_cast<NetESignal*>(expr_);
-      ivl_assert(*this, sig);
-      const netarray_t*array_type = dynamic_cast<const netarray_t*> (sig->sig()->net_type());
-      ivl_assert(*this, array_type);
-
-      return array_type->element_type()->base_type();
+const netenum_t* NetESelect::enumeration() const
+{
+      return dynamic_cast<const netenum_t*> (use_type_);
 }
 
 bool NetESelect::has_width() const

netlist.h

@@ -4401,21 +4401,29 @@ class NetEConcat  : public NetExpr {
  * If the base expression is null, then this expression node can be
  * used to express width expansion, signed or unsigned depending on
  * the has_sign() flag.
+ *
+ * An alternative form of this expression node is used for dynamic
+ * array word selects and for packed struct member selects. In this
+ * case use_type indicates the type of the selected element/member.
  */
 class NetESelect  : public NetExpr {
 
     public:
       NetESelect(NetExpr*exp, NetExpr*base, unsigned wid,
                  ivl_select_type_t sel_type = IVL_SEL_OTHER);
+      NetESelect(NetExpr*exp, NetExpr*base, unsigned wid,
+                 ivl_type_t use_type);
       ~NetESelect();
 
       const NetExpr*sub_expr() const;
       const NetExpr*select() const;
       ivl_select_type_t select_type() const;
 
-	// The type of a NetESelect is the base type of the
-	// sub-expression.
+	// The type of a bit/part select is the base type of the
+	// sub-expression. The type of an array/member select is
+	// the base type of the element/member.
       virtual ivl_variable_type_t expr_type() const;
+      virtual const netenum_t* enumeration() const;
 
       virtual NexusSet* nex_input(bool rem_out = true, bool always_sens = false,
                                   bool nested_func = false) const;
@@ -4431,6 +4439,7 @@ class NetESelect  : public NetExpr {
     private:
       NetExpr*expr_;
       NetExpr*base_;
+      ivl_type_t use_type_;
       ivl_select_type_t sel_type_;
 };
 

parse.y

@@ -68,7 +68,7 @@ static LexicalScope::lifetime_t var_lifetime;
 
 static pform_name_t* pform_create_this(void)
 {
-      name_component_t name (perm_string::literal("@"));
+      name_component_t name (perm_string::literal(THIS_TOKEN));
       pform_name_t*res = new pform_name_t;
       res->push_back(name);
       return res;
@@ -76,7 +76,7 @@ static pform_name_t* pform_create_this(void)
 
 static pform_name_t* pform_create_super(void)
 {
-      name_component_t name (perm_string::literal("#"));
+      name_component_t name (perm_string::literal(SUPER_TOKEN));
       pform_name_t*res = new pform_name_t;
       res->push_back(name);
       return res;
@@ -1364,6 +1364,8 @@ description /* IEEE1800-2005: A.1.2 */
 	delete[] $3;
 	delete[] $5;
       }
+  | ';'
+      { }
   ;
 
 description_list
@@ -2321,7 +2323,7 @@ task_declaration /* IEEE1800-2005: A.2.7 */
       { assert(current_task == 0);
 	current_task = pform_push_task_scope(@1, $3, $2);
       }
-    tf_port_list ')' ';'
+    tf_port_list_opt ')' ';'
     block_item_decls_opt
     statement_or_null_list_opt
     K_endtask
@@ -2329,6 +2331,10 @@ task_declaration /* IEEE1800-2005: A.2.7 */
 	current_task_set_statement(@3, $10);
 	pform_set_this_class(@3, current_task);
 	pform_pop_scope();
+	if (generation_flag < GN_VER2005 && $6 == 0) {
+	      cerr << @3 << ": warning: task definition for \"" << $3
+		   << "\" has an empty port declaration list!" << endl;
+	}
 	current_task = 0;
 	if ($10) delete $10;
       }
@@ -2351,46 +2357,6 @@ task_declaration /* IEEE1800-2005: A.2.7 */
 	delete[]$3;
       }
 
-  | K_task lifetime_opt IDENTIFIER '(' ')' ';'
-      { assert(current_task == 0);
-	current_task = pform_push_task_scope(@1, $3, $2);
-      }
-    block_item_decls_opt
-    statement_or_null_list
-    K_endtask
-      { current_task->set_ports(0);
-	current_task_set_statement(@3, $9);
-	pform_set_this_class(@3, current_task);
-	if (! current_task->method_of()) {
-	      cerr << @3 << ": warning: task definition for \"" << $3
-		   << "\" has an empty port declaration list!" << endl;
-	}
-	pform_pop_scope();
-	current_task = 0;
-	if ($9->size() > 1 && !gn_system_verilog()) {
-	      yyerror(@9, "error: Task body with multiple statements requires SystemVerilog.");
-	}
-	delete $9;
-      }
-    endlabel_opt
-      { // Last step: check any closing name. This is done late so
-	// that the parser can look ahead to detect the present
-	// endlabel_opt but still have the pform_endmodule() called
-	// early enough that the lexor can know we are outside the
-	// module.
-	if ($12) {
-	      if (strcmp($3,$12) != 0) {
-		    yyerror(@12, "error: End label doesn't match task name");
-	      }
-	      if (! gn_system_verilog()) {
-		    yyerror(@12, "error: Task end labels require "
-		                 "SystemVerilog.");
-	      }
-	      delete[]$12;
-	}
-	delete[]$3;
-      }
-
   | K_task lifetime_opt IDENTIFIER error K_endtask
       {
 	if (current_task) {
@@ -5315,14 +5281,14 @@ module_item
       { pform_endgenerate(false); }
 
   | generate_if
-    generate_block_opt
+    generate_block
     K_else
       { pform_start_generate_else(@1); }
     generate_block
       { pform_endgenerate(true); }
 
   | generate_if
-    generate_block_opt %prec less_than_K_else
+    generate_block %prec less_than_K_else
       { pform_endgenerate(true); }
 
   | K_case '(' expression ')'
@@ -5360,50 +5326,51 @@ module_item
      module items. These rules try to catch them at a point where a
      reasonable error message can be produced. */
 
-	| error ';'
-		{ yyerror(@2, "error: invalid module item.");
-		  yyerrok;
-		}
+  | error ';'
+      { yyerror(@2, "error: invalid module item.");
+	yyerrok;
+      }
 
-	| K_assign error '=' expression ';'
-		{ yyerror(@1, "error: syntax error in left side "
-			  "of continuous assignment.");
-		  yyerrok;
-		}
+  | K_assign error '=' expression ';'
+      { yyerror(@1, "error: syntax error in left side of "
+	            "continuous assignment.");
+	yyerrok;
+      }
 
-	| K_assign error ';'
-		{ yyerror(@1, "error: syntax error in "
-			  "continuous assignment");
-		  yyerrok;
-		}
+   | K_assign error ';'
+      { yyerror(@1, "error: syntax error in continuous assignment");
+	yyerrok;
+      }
 
-	| K_function error K_endfunction endlabel_opt
-		{ yyerror(@1, "error: I give up on this "
-			  "function definition.");
-		  if ($4) {
-			if (!gn_system_verilog()) {
-			      yyerror(@4, "error: Function end names require "
-			                  "SystemVerilog.");
-			}
-			delete[]$4;
-		  }
-		  yyerrok;
-		}
+  | K_function error K_endfunction endlabel_opt
+      { yyerror(@1, "error: I give up on this function definition.");
+	if ($4) {
+	    if (!gn_system_verilog()) {
+		  yyerror(@4, "error: Function end names require "
+		              "SystemVerilog.");
+	    }
+	    delete[]$4;
+	}
+	yyerrok;
+      }
 
   /* These rules are for the Icarus Verilog specific $attribute
      extensions. Then catch the parameters of the $attribute keyword. */
 
-	| KK_attribute '(' IDENTIFIER ',' STRING ',' STRING ')' ';'
-		{ perm_string tmp3 = lex_strings.make($3);
-		  perm_string tmp5 = lex_strings.make($5);
-		  pform_set_attrib(tmp3, tmp5, $7);
-		  delete[] $3;
-		  delete[] $5;
-		}
-	| KK_attribute '(' error ')' ';'
-		{ yyerror(@1, "error: Malformed $attribute parameter list."); }
+  | KK_attribute '(' IDENTIFIER ',' STRING ',' STRING ')' ';'
+      { perm_string tmp3 = lex_strings.make($3);
+	perm_string tmp5 = lex_strings.make($5);
+	pform_set_attrib(tmp3, tmp5, $7);
+	delete[] $3;
+	delete[] $5;
+      }
+  | KK_attribute '(' error ')' ';'
+      { yyerror(@1, "error: Malformed $attribute parameter list."); }
 
-	;
+  | ';'
+      { }
+
+  ;
 
 module_item_list
   : module_item_list module_item
@@ -5423,9 +5390,9 @@ generate_case_items
   ;
 
 generate_case_item
-  : expression_list_proper ':' { pform_generate_case_item(@1, $1); } generate_block_opt
+  : expression_list_proper ':' { pform_generate_case_item(@1, $1); } generate_block
       { pform_endgenerate(false); }
-  | K_default ':' { pform_generate_case_item(@1, 0); } generate_block_opt
+  | K_default ':' { pform_generate_case_item(@1, 0); } generate_block
       { pform_endgenerate(false); }
   ;
 
@@ -5487,9 +5454,6 @@ generate_block
       }
   ;
 
-generate_block_opt : generate_block | ';' ;
-
-
   /* A net declaration assignment allows the programmer to combine the
      net declaration and the continuous assignment into a single
      statement.
@@ -6933,6 +6897,9 @@ statement_item /* This is roughly statement_item in the LRM */
   | implicit_class_handle '.' K_new '(' expression_list_with_nuls ')' ';'
       { PChainConstructor*tmp = new PChainConstructor(*$5);
 	FILE_NAME(tmp, @3);
+	if (peek_head_name(*$1) == THIS_TOKEN) {
+	  yyerror(@1, "error: this.new is invalid syntax. Did you mean super.new?");
+	}
 	delete $1;
 	$$ = tmp;
       }

pform.cc

@@ -297,7 +297,7 @@ void parm_to_defparam_list(const string&param)
 
     // Is it a decimal number?
     num = (value[0] == '-') ? value + 1 : value;
-    if (is_dec_digit_str(num)) {
+    if (num[0] != '\0' && is_dec_digit_str(num)) {
 	verinum *val = make_unsized_dec(num);
 	if (value[0] == '-') *val = -(*val);
 	PExpr* ndec = new PENumber(val);

pform_pclass.cc

@@ -109,7 +109,7 @@ void pform_set_this_class(const struct vlltype&loc, PTaskFunc*net)
 	    return;
 
       list<perm_string>*this_name = new list<perm_string>;
-      this_name->push_back(perm_string::literal("@"));
+      this_name->push_back(perm_string::literal(THIS_TOKEN));
       vector<pform_tf_port_t>*this_port = pform_make_task_ports(loc,
 						       NetNet::PINPUT,
 						       pform_cur_class->type,

pform_types.h

@@ -381,6 +381,14 @@ inline perm_string peek_tail_name(const pform_name_t&that)
       return that.back().name;
 }
 
+/*
+ * In pform names, the "super" and "this" keywords are converted to
+ * These tokens so that they don't interfere with the namespace and
+ * are handled specially.
+ */
+# define SUPER_TOKEN "#"
+# define THIS_TOKEN  "@"
+
 extern std::ostream& operator<< (std::ostream&out, const pform_name_t&);
 extern std::ostream& operator<< (std::ostream&out, const name_component_t&that);
 extern std::ostream& operator<< (std::ostream&out, const index_component_t&that);

tgt-vvp/stmt_assign.c

@@ -954,7 +954,7 @@ static int show_stmt_assign_darray_pattern(ivl_statement_t net)
 
 // FIXME: At the moment we reallocate the array space.
 //        This probably should be a resize to avoid values glitching
-	/* Allocate at least enough space for the array patter. */
+	/* Allocate at least enough space for the array pattern. */
       fprintf(vvp_out, "    %%ix/load %u, %u, 0;\n", size_reg, ivl_expr_parms(rval));
 	/* This can not have have a X/Z value so clear flag 4. */
       fprintf(vvp_out, "    %%flag_set/imm 4, 0;\n");
@@ -1038,12 +1038,36 @@ static int show_stmt_assign_sig_darray(ivl_statement_t net)
 		 elements of the l-value. */
 	    errors += show_stmt_assign_darray_pattern(net);
 
-      } else {
-	      /* There is no l-value mux, so this must be an
-		 assignment to the array as a whole. Evaluate the
-		 "object", and store the evaluated result. */
+      } else if (ivl_expr_type(rval) == IVL_EX_NEW) {
+	    // There is no l-value mux, and the r-value expression is
+	    // a "new" expression. Handle this by simply storing the
+	    // new object to the lval.
 	    errors += draw_eval_object(rval);
-	    fprintf(vvp_out, "    %%store/obj v%p_0;\n", var);
+	    fprintf(vvp_out, "    %%store/obj v%p_0; %s:%u: %s = new ...\n",
+		    var, ivl_stmt_file(net), ivl_stmt_lineno(net),
+		    ivl_signal_basename(var));
+
+      } else if (ivl_expr_type(rval) == IVL_EX_SIGNAL) {
+
+	    // There is no l-value mux, and the r-value expression is
+	    // a "signal" expression. Store a duplicate into the lvalue
+	    // By using the %dup/obj. Remember to pop the rvalue that
+	    // is no longer needed.
+	    errors += draw_eval_object(rval);
+	    fprintf(vvp_out, "    %%dup/obj;\n");
+	    fprintf(vvp_out, "    %%store/obj v%p_0; %s:%u: %s = <signal>\n",
+		    var, ivl_stmt_file(net), ivl_stmt_lineno(net),
+		    ivl_signal_basename(var));
+	    fprintf(vvp_out, "    %%pop/obj 1, 0;\n");
+
+      } else {
+	    // There is no l-value mux, so this must be an
+	    // assignment to the array as a whole. Evaluate the
+	    // "object", and store the evaluated result.
+	    errors += draw_eval_object(rval);
+	    fprintf(vvp_out, "    %%store/obj v%p_0; %s:%u: %s = <expr type %d>\n",
+		    var, ivl_stmt_file(net), ivl_stmt_lineno(net),
+		    ivl_signal_basename(var), ivl_expr_type(rval));
       }
 
       return errors;

verilog.spec

@@ -1,6 +1,6 @@
 #norootforbuild
 #
-%define rev_date 20150815
+%define rev_date 20201003
 # Normally, the suff-ix is %nil, meaning the suffix is to not be used.
 # But if the builder wants to make a suffixed package, he may set this
 # to a value (i.e. -test) to cause suffixes to be put in all the right
@@ -10,7 +10,7 @@
 #
 Summary: Icarus Verilog
 Name: verilog%{suff}
-Version: 11.0.%{rev_date}
+Version: 12.0.%{rev_date}
 Release: 0
 License: GPL
 Group: Productivity/Scientific/Electronics

version_base.h

@@ -3,7 +3,7 @@
  * Edit this definition in version_base.in to define the base version
  * number for the compiled result.
  */
-# define VERSION_MAJOR  11
+# define VERSION_MAJOR  12
 # define VERSION_MINOR   0
 
 /*

vvp/codes.h

@@ -107,6 +107,7 @@ extern bool of_DISABLE_FORK(vthread_t thr, vvp_code_t code);
 extern bool of_DIV(vthread_t thr, vvp_code_t code);
 extern bool of_DIV_S(vthread_t thr, vvp_code_t code);
 extern bool of_DIV_WR(vthread_t thr, vvp_code_t code);
+extern bool of_DUP_OBJ(vthread_t thr, vvp_code_t code);
 extern bool of_DUP_REAL(vthread_t thr, vvp_code_t code);
 extern bool of_DUP_VEC4(vthread_t thr, vvp_code_t code);
 extern bool of_END(vthread_t thr, vvp_code_t code);

vvp/compile.cc

@@ -159,6 +159,7 @@ static const struct opcode_table_s opcode_table[] = {
       { "%div",      of_DIV,     0, {OA_NONE,   OA_NONE,     OA_NONE} },
       { "%div/s",    of_DIV_S,   0, {OA_NONE,   OA_NONE,     OA_NONE} },
       { "%div/wr",   of_DIV_WR,  0, {OA_NONE,   OA_NONE,     OA_NONE} },
+      { "%dup/obj",  of_DUP_OBJ, 0, {OA_NONE,   OA_NONE,     OA_NONE} },
       { "%dup/real", of_DUP_REAL,0, {OA_NONE,   OA_NONE,     OA_NONE} },
       { "%dup/vec4", of_DUP_VEC4,0, {OA_NONE,   OA_NONE,     OA_NONE} },
       { "%end",    of_END,    0,  {OA_NONE,     OA_NONE,     OA_NONE} },

vvp/examples/assign_reg.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/copy.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/disable.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/edge.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/fork.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/hello.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/hello2.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/memory.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/set_reg.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/sum.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/time.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ; Copyright (c) 2001-2015  Stephen Williams ([email protected])

vvp/examples/vector.vvp

@@ -1,4 +1,4 @@
-:ivl_version "11.0" "vec4-stack";
+:ivl_version "12.0" "vec4-stack";
 :vpi_module "system";
 
 ;    This program is free software; you can redistribute it and/or modify

vvp/opcodes.txt

@@ -491,8 +491,9 @@ This opcode divides the left operand by the right operand. If the
 right operand is 0, then the result is NaN.
 
 
-* dup/real
-* dup/vec4
+* %dup/real
+* %dup/vec4
+* %dup/obj
 
 These opcodes duplicate the value on the top of the stack for the
 corresponding type.

vvp/vthread.cc

@@ -3002,6 +3002,19 @@ bool of_DIV_WR(vthread_t thr, vvp_code_t)
       return true;
 }
 
+/*
+ * %dup/obj
+ * %dup/real
+ * %dup/vec4
+ *
+ * Push a duplicate of the object on the appropriate stack.
+ */
+bool of_DUP_OBJ(vthread_t thr, vvp_code_t)
+{
+      thr->push_object(thr->peek_object().duplicate());
+      return true;
+}
+
 bool of_DUP_REAL(vthread_t thr, vvp_code_t)
 {
       thr->push_real(thr->peek_real(0));
@@ -5596,6 +5609,17 @@ bool of_RETLOAD_VEC4(vthread_t thr, vvp_code_t cp)
       return retload<vvp_vector4_t>(thr, cp);
 }
 
+/*
+ * %scopy
+ *
+ * Pop the top item from the object stack, and shallow_copy() that item into
+ * the new top of the object stack. This will copy at many items as needed
+ * from the source object to fill the target object. If the target object is
+ * larger then the source object, then some items will be left unchanged.
+ *
+ * The object may be any kind of object that supports shallow_copy(),
+ * including dynamic arrays and class objects.
+ */
 bool of_SCOPY(vthread_t thr, vvp_code_t)
 {
       vvp_object_t tmp;

vvp/vvp_darray.cc

@@ -67,11 +67,6 @@ void vvp_darray::get_word(unsigned, vvp_object_t&)
       cerr << "XXXX get_word(vvp_object_t) not implemented for " << typeid(*this).name() << endl;
 }
 
-void vvp_darray::shallow_copy(const vvp_object*)
-{
-      cerr << "XXXX shallow_copy(vvp_object_t) not implemented for " << typeid(*this).name() << endl;
-}
-
 vvp_vector4_t vvp_darray::get_bitstream(bool)
 {
       cerr << "XXXX get_bitstream() not implemented for " << typeid(*this).name() << endl;
@@ -122,6 +117,15 @@ template <class TYPE> void vvp_darray_atom<TYPE>::shallow_copy(const vvp_object*
 	    array_[idx] = that->array_[idx];
 }
 
+template <class TYPE> vvp_object* vvp_darray_atom<TYPE>::duplicate(void) const
+{
+      vvp_darray_atom<TYPE>*that = new vvp_darray_atom<TYPE>(array_.size());
+      for (size_t idx = 0 ; idx < array_.size() ; idx += 1)
+	    that->array_[idx] = array_[idx];
+
+      return that;
+}
+
 template <class TYPE> vvp_vector4_t vvp_darray_atom<TYPE>::get_bitstream(bool)
 {
       const unsigned word_wid = sizeof(TYPE) * 8;
@@ -192,6 +196,16 @@ void vvp_darray_vec4::shallow_copy(const vvp_object*obj)
 	    array_[idx] = that->array_[idx];
 }
 
+vvp_object* vvp_darray_vec4::duplicate(void) const
+{
+      vvp_darray_vec4*that = new vvp_darray_vec4(array_.size(), word_wid_);
+
+      for (size_t idx = 0 ; idx < array_.size() ; idx += 1)
+	    that->array_[idx] = array_[idx];
+
+      return that;
+}
+
 vvp_vector4_t vvp_darray_vec4::get_bitstream(bool as_vec4)
 {
       vvp_vector4_t vec(array_.size() * word_wid_, BIT4_0);
@@ -344,6 +358,16 @@ void vvp_darray_real::shallow_copy(const vvp_object*obj)
 	    array_[idx] = that->array_[idx];
 }
 
+vvp_object* vvp_darray_real::duplicate(void) const
+{
+      vvp_darray_real*that = new vvp_darray_real(array_.size());
+
+      for (size_t idx = 0 ; idx < array_.size() ; idx += 1)
+	    that->array_[idx] = array_[idx];
+
+      return that;
+}
+
 vvp_vector4_t vvp_darray_real::get_bitstream(bool)
 {
       const unsigned word_wid = sizeof(double) * 8;
@@ -406,6 +430,16 @@ void vvp_darray_string::shallow_copy(const vvp_object*obj)
 	    array_[idx] = that->array_[idx];
 }
 
+vvp_object* vvp_darray_string::duplicate(void) const
+{
+      vvp_darray_string*that = new vvp_darray_string(array_.size());
+
+      for (size_t idx = 0 ; idx < array_.size() ; idx += 1)
+	    that->array_[idx] = array_[idx];
+
+      return that;
+}
+
 vvp_queue::~vvp_queue()
 {
 }
@@ -591,22 +625,7 @@ void vvp_queue_real::insert(unsigned idx, double value, unsigned max_size)
 		       << max_size << "]." << endl;
 		  queue.pop_back();
 	    }
-	      // Inserting at the beginning
-	    if (idx == 0)
-		  queue.push_front(value);
-	      // Inserting in the middle
-	    else {
-		  std::deque<double>::iterator pos;
-		  unsigned middle = queue.size()/2;
-		  if (idx < middle) {
-			pos = queue.begin();
-			for (unsigned count = 0; count < idx; ++count) ++pos;
-		  } else {
-			pos = queue.end();
-			for (unsigned count = queue.size(); count > idx; --count) --pos;
-		  }
-		  queue.insert(pos, value);
-	    }
+	    queue.insert(queue.begin()+idx, value);
       }
 }
 
@@ -635,17 +654,8 @@ void vvp_queue_real::push_front(double value, unsigned max_size)
 
 void vvp_queue_real::erase(unsigned idx)
 {
-      std::deque<double>::iterator pos;
-      unsigned middle = queue.size()/2;
-      if (idx < middle) {
-	    pos = queue.begin();
-	    for (unsigned count = 0; count < idx; ++count) ++pos;
-      } else {
-	    pos = queue.end();
-	    for (unsigned count = queue.size(); count > idx; --count) --pos;
-      }
-
-      queue.erase(pos);
+      assert(queue.size() > idx);
+      queue.erase(queue.begin()+idx);
 }
 
 void vvp_queue_real::erase_tail(unsigned idx)
@@ -727,22 +737,7 @@ void vvp_queue_string::insert(unsigned idx, const string&value, unsigned max_siz
 		       << max_size << "]." << endl;
 		  queue.pop_back();
 	    }
-	      // Inserting at the beginning
-	    if (idx == 0)
-		  queue.push_front(value);
-	      // Inserting in the middle
-	    else {
-		  std::deque<string>::iterator pos;
-		  unsigned middle = queue.size()/2;
-		  if (idx < middle) {
-			pos = queue.begin();
-			for (unsigned count = 0; count < idx; ++count) ++pos;
-		  } else {
-			pos = queue.end();
-			for (unsigned count = queue.size(); count > idx; --count) --pos;
-		  }
-		  queue.insert(pos, value);
-	    }
+	    queue.insert(queue.begin()+idx, value);
       }
 }
 
@@ -771,17 +766,8 @@ void vvp_queue_string::push_front(const string&value, unsigned max_size)
 
 void vvp_queue_string::erase(unsigned idx)
 {
-      std::deque<std::string>::iterator pos;
-      unsigned middle = queue.size()/2;
-      if (idx < middle) {
-	    pos = queue.begin();
-	    for (unsigned count = 0; count < idx; ++count) ++pos;
-      } else {
-	    pos = queue.end();
-	    for (unsigned count = queue.size(); count > idx; --count) --pos;
-      }
-
-      queue.erase(pos);
+      assert(queue.size() > idx);
+      queue.erase(queue.begin()+idx);
 }
 
 void vvp_queue_string::erase_tail(unsigned idx)
@@ -863,22 +849,7 @@ void vvp_queue_vec4::insert(unsigned idx, const vvp_vector4_t&value, unsigned ma
 		       << value.size() << "]> [" << max_size << "]." << endl;
 		  queue.pop_back();
 	    }
-	      // Inserting at the beginning
-	    if (idx == 0)
-		  queue.push_front(value);
-	      // Inserting in the middle
-	    else {
-		  std::deque<vvp_vector4_t>::iterator pos;
-		  unsigned middle = queue.size()/2;
-		  if (idx < middle) {
-			pos = queue.begin();
-			for (unsigned count = 0; count < idx; ++count) ++pos;
-		  } else {
-			pos = queue.end();
-			for (unsigned count = queue.size(); count > idx; --count) --pos;
-		  }
-		  queue.insert(pos, value);
-	    }
+	    queue.insert(queue.begin()+idx, value);
       }
 }
 
@@ -907,17 +878,8 @@ void vvp_queue_vec4::push_front(const vvp_vector4_t&value, unsigned max_size)
 
 void vvp_queue_vec4::erase(unsigned idx)
 {
-      std::deque<vvp_vector4_t>::iterator pos;
-      unsigned middle = queue.size()/2;
-      if (idx < middle) {
-	    pos = queue.begin();
-	    for (unsigned count = 0; count < idx; ++count) ++pos;
-      } else {
-	    pos = queue.end();
-	    for (unsigned count = queue.size(); count > idx; --count) --pos;
-      }
-
-      queue.erase(pos);
+      assert(queue.size() > idx);
+      queue.erase(queue.begin()+idx);
 }
 
 void vvp_queue_vec4::erase_tail(unsigned idx)

vvp/vvp_darray.h

@@ -45,8 +45,6 @@ class vvp_darray : public vvp_object {
       virtual void set_word(unsigned adr, const vvp_object_t&value);
       virtual void get_word(unsigned adr, vvp_object_t&value);
 
-      virtual void shallow_copy(const vvp_object*obj);
-
       virtual vvp_vector4_t get_bitstream(bool as_vec4);
 };
 
@@ -60,6 +58,7 @@ template <class TYPE> class vvp_darray_atom : public vvp_darray {
       void set_word(unsigned adr, const vvp_vector4_t&value);
       void get_word(unsigned adr, vvp_vector4_t&value);
       void shallow_copy(const vvp_object*obj);
+      vvp_object* duplicate(void) const;
       vvp_vector4_t get_bitstream(bool as_vec4);
 
     private:
@@ -77,6 +76,7 @@ class vvp_darray_vec4 : public vvp_darray {
       void set_word(unsigned adr, const vvp_vector4_t&value);
       void get_word(unsigned adr, vvp_vector4_t&value);
       void shallow_copy(const vvp_object*obj);
+      vvp_object* duplicate(void) const;
       vvp_vector4_t get_bitstream(bool as_vec4);
 
     private:
@@ -112,6 +112,7 @@ class vvp_darray_real : public vvp_darray {
       void set_word(unsigned adr, double value);
       void get_word(unsigned adr, double&value);
       void shallow_copy(const vvp_object*obj);
+      vvp_object* duplicate(void) const;
       vvp_vector4_t get_bitstream(bool as_vec4);
 
     private:
@@ -128,6 +129,7 @@ class vvp_darray_string : public vvp_darray {
       void set_word(unsigned adr, const std::string&value);
       void get_word(unsigned adr, std::string&value);
       void shallow_copy(const vvp_object*obj);
+      vvp_object* duplicate(void) const;
 
     private:
       std::vector<std::string> array_;
@@ -143,6 +145,7 @@ class vvp_darray_object : public vvp_darray {
       void set_word(unsigned adr, const vvp_object_t&value);
       void get_word(unsigned adr, vvp_object_t&value);
       void shallow_copy(const vvp_object*obj);
+      //virtual vvp_object* duplicate(void) const;
 
     private:
       std::vector<vvp_object_t> array_;

vvp/vvp_object.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2013 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2012-2020 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -37,5 +37,13 @@ vvp_object::~vvp_object()
 
 void vvp_object::shallow_copy(const vvp_object*)
 {
+      cerr << "XXXX shallow_copy(vvp_object_t) not implemented for " << typeid(*this).name() << endl;
       assert(0);
 }
+
+vvp_object* vvp_object::duplicate(void) const
+{
+      cerr << "XXXX duplicate() not implemented for " << typeid(*this).name() << endl;
+      assert(0);
+      return 0;
+}

vvp/vvp_object.h

@@ -1,7 +1,7 @@
 #ifndef IVL_vvp_object_H
 #define IVL_vvp_object_H
 /*
- * Copyright (c) 2012-2014 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2012-2020 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -33,6 +33,7 @@ class vvp_object {
       virtual ~vvp_object() =0;
 
       virtual void shallow_copy(const vvp_object*that);
+      virtual vvp_object* duplicate(void) const;
 
       static void cleanup(void);
 
@@ -63,6 +64,9 @@ class vvp_object_t {
 
       inline void shallow_copy(const vvp_object_t&that)
           { ref_->shallow_copy(that.ref_); }
+      inline vvp_object_t duplicate(void) const
+          { return vvp_object_t(ref_->duplicate()); }
+
       template <class T> T*peek(void) const;
 
     private: