Warning for $display/$write outside initial block

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 77d4447f596e2674c14cbb60db061e905be47be1..2abb48a584a37aa8c247a092324f8e6bad8b44b7 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -182,20 +182,21 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
                str = std::string();
        }
 
+       if ((type == AST_TCALL) && (str == "$display" || str == "$write") && (!current_always || current_always->type != AST_INITIAL)) {
+               log_warning("System task `%s' outside initial block is unsupported at %s:%d.\n", str.c_str(), filename.c_str(), linenum);
+               delete_children();
+               str = std::string();
+       }
+
        // print messages if this a call to $display() or $write()
        // This code implements only a small subset of Verilog-2005 $display() format specifiers,
        // but should be good enough for most uses
        if ((type == AST_TCALL) && ((str == "$display") || (str == "$write")))
        {
-               if (!current_always || current_always->type != AST_INITIAL)
-                       log_error("System task `$display' outside initial block is unsupported at %s:%d.\n", filename.c_str(), linenum);
-
                size_t nargs = GetSize(children);
                if(nargs < 1)
-               {
-                       log_error("System task `$display' got %d arguments, expected >= 1 at %s:%d.\n",
-                               int(children.size()), filename.c_str(), linenum);
-               }
+                       log_error("System task `%s' got %d arguments, expected >= 1 at %s:%d.\n",
+                                       str.c_str(), int(children.size()), filename.c_str(), linenum);
 
                // First argument is the format string
                AstNode *node_string = children[0]->clone();