Add support for disable fork to the compiler.

design_dump.cc

@@ -1036,8 +1036,10 @@ void NetDeassign::dump(ostream&o, unsigned ind) const
 
 void NetDisable::dump(ostream&o, unsigned ind) const
 {
-      o << setw(ind) << "" << "disable " << scope_path(target_) << "; "
-	<< "/* " << get_fileline() << " */" << endl;
+      o << setw(ind) << "" << "disable ";
+      if (target_) o << scope_path(target_);
+      else o << "fork";
+      o << "; " << "/* " << get_fileline() << " */" << endl;
 }
 
 void NetDoWhile::dump(ostream&o, unsigned ind) const

elaborate.cc

@@ -3713,6 +3713,22 @@ NetProc* PDisable::elaborate(Design*des, NetScope*scope) const
 {
       assert(scope);
 
+	/* If the disable scope_ is empty then this is a SystemVerilog
+	 * disable fork statement. */
+      if (scope_.empty()) {
+	    if (gn_system_verilog()) {
+		  NetDisable*obj = new NetDisable(0);
+		  obj->set_line(*this);
+		  return obj;
+	    } else {
+		  cerr << get_fileline()
+		       << ": error: 'disable fork' requires SystemVerilog."
+		       << endl;
+		  des->errors += 1;
+		  return 0;
+	    }
+      }
+
       list<hname_t> spath = eval_scope_path(des, scope, scope_);
 
       NetScope*target = des->find_scope(scope, spath);

parse.y

@@ -5594,6 +5594,12 @@ statement_item /* This is roughly statement_item in the LRM */
 		  delete $2;
 		  $$ = tmp;
 		}
+	| K_disable K_fork ';'
+		{ pform_name_t tmp_name;
+		  PDisable*tmp = new PDisable(tmp_name);
+		  FILE_NAME(tmp, @1);
+		  $$ = tmp;
+		}
 	| K_TRIGGER hierarchy_identifier ';'
 		{ PTrigger*tmp = new PTrigger(*$2);
 		  FILE_NAME(tmp, @1);

pform_dump.cc

@@ -841,8 +841,10 @@ void PDelayStatement::dump(ostream&out, unsigned ind) const
 
 void PDisable::dump(ostream&out, unsigned ind) const
 {
-      out << setw(ind) << "" << "disable " << scope_ << "; /* "
-	  << get_fileline() << " */" << endl;
+      out << setw(ind) << "" << "disable ";
+      if (scope_.empty()) out << scope_;
+      else out << "fork";
+      out << "; /* " << get_fileline() << " */" << endl;
 }
 
 void PDoWhile::dump(ostream&out, unsigned ind) const

t-dll-proc.cc

@@ -613,7 +613,11 @@ bool dll_target::proc_disable(const NetDisable*net)
       FILE_NAME(stmt_cur_, net);
 
       stmt_cur_->type_ = IVL_ST_DISABLE;
-      stmt_cur_->u_.disable_.scope = lookup_scope_(net->target());
+      const NetScope* dis_scope = net->target();
+	/* A normal disable. */
+      if (dis_scope) stmt_cur_->u_.disable_.scope = lookup_scope_(dis_scope);
+	/* A SystemVerilog disable fork. */
+      else stmt_cur_->u_.disable_.scope = 0;
       return true;
 }
 

tgt-stub/statement.c

@@ -156,7 +156,11 @@ static void show_stmt_delayx(ivl_statement_t net, unsigned ind)
 static void show_stmt_disable(ivl_statement_t net, unsigned ind)
 {
       ivl_scope_t scope = ivl_stmt_call(net);
-      fprintf(out, "%*sdisable %s\n", ind, "", ivl_scope_basename(scope));
+      if (scope) {
+	    fprintf(out, "%*sdisable %s\n", ind, "", ivl_scope_basename(scope));
+      } else {
+	    fprintf(out, "%*sdisable fork\n", ind, "");
+      }
 }
 
 static void show_stmt_force(ivl_statement_t net, unsigned ind)

tgt-vlog95/stmt.c

@@ -1068,11 +1068,22 @@ static void emit_stmt_disable(ivl_scope_t scope, ivl_statement_t stmt)
 {
       ivl_scope_t disable_scope = ivl_stmt_call(stmt);
       fprintf(vlog_out, "%*cdisable ", get_indent(), ' ');
-	/* If this disable is in a function and it is disabling the function
-	 * then emit the appropriate function return name. */
-      if (func_rtn_name && is_func_disable(scope, disable_scope)) {
-	    fprintf(vlog_out, "%s", func_rtn_name);
-      } else emit_scope_path(scope, disable_scope);
+	/* A normal disable statement. */
+      if (disable_scope) {
+	      /* If this disable is in a function and it is disabling the
+	       * function then emit the appropriate function return name. */
+	    if (func_rtn_name && is_func_disable(scope, disable_scope)) {
+		  fprintf(vlog_out, "%s", func_rtn_name);
+	    } else emit_scope_path(scope, disable_scope);
+	/* A SystemVerilog disable fork statement cannot be converted. */
+      } else {
+	    fprintf(vlog_out, "fork");
+	    fprintf(stderr, "%s:%u: vlog95 sorry: disable fork is not "
+	                    "currently translated.\n",
+	                    ivl_stmt_file(stmt),
+	                    ivl_stmt_lineno(stmt));
+	    vlog_errors += 1;
+      }
       fprintf(vlog_out, ";");
       emit_stmt_file_line(stmt);
       fprintf(vlog_out, "\n");

tgt-vvp/vvp_process.c

@@ -1359,9 +1359,15 @@ static int show_stmt_disable(ivl_statement_t net, ivl_scope_t sscope)
       int rc = 0;
       ivl_scope_t target = ivl_stmt_call(net);
 
-      show_stmt_file_line(net, "Disable statement.");
-
-      fprintf(vvp_out, "    %%disable S_%p;\n", target);
+	/* A normal disable statement. */
+      if (target) {
+	    show_stmt_file_line(net, "Disable statement.");
+	    fprintf(vvp_out, "    %%disable S_%p;\n", target);
+	/* A SystemVerilog disable fork statement. */
+      } else {
+	    show_stmt_file_line(net, "Disable fork statement.");
+	    fprintf(vvp_out, "    %%disable/fork;\n");
+      }
 
       return rc;
 }