Cannot use posedge, negedge or edge with a real expression

elaborate.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2022 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2023 Stephen Williams (steve@icarus.com)
  * Copyright CERN 2013 / Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
@@ -4886,6 +4886,29 @@ cerr << endl;
 		  continue;
 	    }
 
+	      // posedge, negedge and edge are not allowed on real expressions.
+	    if ((tmp->expr_type() == IVL_VT_REAL) &&
+	        (expr_[idx]->type() != PEEvent::ANYEDGE)) {
+		  cerr << get_fileline() << ": error: '";
+		  switch (expr_[idx]->type()) {
+		    case PEEvent::POSEDGE:
+			cerr << "posedge";
+			break;
+		    case PEEvent::NEGEDGE:
+			cerr << "negedge";
+			break;
+		    case PEEvent::EDGE:
+			cerr << "edge";
+			break;
+		    default:
+			ivl_assert(*this, 0);
+		  }
+		  cerr << "' cannot be used with real expressions '"
+		       << *expr_[idx]->expr() << "'." << endl;
+		  des->errors += 1;
+		  continue;
+	    }
+
 	    NetNet*expr = tmp->synthesize(des, scope, tmp);
 	    if (expr == 0) {
 		  expr_[idx]->dump(cerr);

ivtest/gold/real_edges.gold

@@ -0,0 +1,4 @@
+./ivltests/real_edges.v:5: error: 'posedge' cannot be used with real expressions 'rval'.
+./ivltests/real_edges.v:6: error: 'negedge' cannot be used with real expressions 'rval'.
+./ivltests/real_edges.v:7: error: 'edge' cannot be used with real expressions 'rval'.
+3 error(s) during elaboration.

ivtest/ivltests/real_edges.v

@@ -0,0 +1,13 @@
+module top;
+  real rval;
+
+  always @(rval) $display("any change");
+  always @(posedge rval) $display("posedge");
+  always @(negedge rval) $display("negedge");
+  always @(edge rval) $display("edge");
+
+  initial begin
+    #1 rval = 1.0;
+    #1 rval = 0.0;
+  end
+endmodule

ivtest/regress-sv.list

@@ -996,3 +996,4 @@ br_gh840a               CE,-g2012               ivltests
 br_gh840b               CE,-g2012               ivltests
 bitsel_real_idx		CE,-g2012		ivltests gold=bitsel_real_idx.gold
 partsel_real_idx	CE,-g2012		ivltests gold=partsel_real_idx.gold
+real_edges		CE,-g2012		ivltests gold=real_edges.gold