Add check for parameters used before they are declared.

PScope.h

@@ -1,7 +1,7 @@
 #ifndef IVL_PScope_H
 #define IVL_PScope_H
 /*
- * Copyright (c) 2008-2021 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2008-2024 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
@@ -121,6 +121,8 @@ class LexicalScope {
 	    bool overridable;
 	      // Whether the parameter is a type parameter
 	    bool type_flag = false;
+	      // The lexical position of the declaration
+	    unsigned lexical_pos = 0;
 
 	    SymbolType symbol_type() const;
       };

net_scope.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2021 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2000-2024 Stephen Williams (steve@icarus.com)
  * Copyright (c) 2016 CERN Michele Castellana (michele.castellana@cern.ch)
  *
  *    This source code is free software; you can redistribute it
@@ -280,6 +280,7 @@ void NetScope::set_parameter(perm_string key, bool is_annotatable,
       ref.local_flag = param.local_flag;
       ref.overridable = param.overridable;
       ref.type_flag = param.type_flag;
+      ref.lexical_pos = param.lexical_pos;
       ivl_assert(param, !ref.range);
       ref.range = range_list;
       ref.val = 0;
@@ -449,6 +450,17 @@ LineInfo NetScope::get_parameter_line_info(perm_string key) const
       return LineInfo();
 }
 
+unsigned NetScope::get_parameter_lexical_pos(perm_string key) const
+{
+      map<perm_string,param_expr_t>::const_iterator idx;
+
+      idx = parameters.find(key);
+      if (idx != parameters.end()) return idx->second.lexical_pos;
+
+	// If we get here, assume an enumeration value.
+      return 0;
+}
+
 void NetScope::print_type(ostream&stream) const
 {
       switch (type_) {
@@ -879,4 +891,3 @@ void NetScope::add_tie_lo(Design*des)
 	    connect(sig->pin(0), tie_lo_->pin(0));
       }
 }
-

netlist.h

@@ -1243,6 +1243,8 @@ class NetScope : public Definitions, public Attrib {
 	    bool overridable = false;
 	    // Is it a type parameter
 	    bool type_flag = false;
+	    // The lexical position of the declaration
+	    unsigned lexical_pos = 0;
 	    // range constraints
 	    struct range_t*range;
 
@@ -1261,6 +1263,8 @@ class NetScope : public Definitions, public Attrib {
 
       LineInfo get_parameter_line_info(perm_string name) const;
 
+      unsigned get_parameter_lexical_pos(perm_string name) const;
+
 	/* Module instance arrays are collected here for access during
 	   the multiple elaboration passes. */
       typedef std::vector<NetScope*> scope_vec_t;

pform.cc

@@ -2953,6 +2953,7 @@ void pform_set_parameter(const struct vlltype&loc,
       parm->local_flag = is_local;
       parm->overridable = overridable;
       parm->type_flag = is_type;
+      parm->lexical_pos = loc.lexical_pos;
 
       scope->parameters[name] = parm;
 

symbol_search.cc

@@ -184,11 +184,13 @@ bool symbol_search(const LineInfo*li, Design*des, NetScope*scope,
 		  }
 
 		  if (const NetExpr*par = scope->get_parameter(des, path_tail.name, res->type)) {
-		    path.push_back(path_tail);
+			if (prefix_scope || (scope->get_parameter_lexical_pos(path_tail.name) <= lexical_pos)) {
-		    res->scope = scope;
+			      path.push_back(path_tail);
-		    res->par_val = par;
+			      res->scope = scope;
-		    res->path_head = path;
+			      res->par_val = par;
-		    return true;
+			      res->path_head = path;
+			      return true;
+			}
 		  }
 
 		    // Static items are just normal signals and are found above.