Report error when trying to override non-existing parameter

Overriding a parameter that does not exist will only generate a warning at
the moment. This can hide programming mistakes such as an typo in a
parameter override.

There is nothing in the LRMs to support that this should only be warning,
so elevate this to an error. This is consistent with how an error is
generated when trying to reference a non-existing port or variable.

The generated error message differentiates between whether the parameter
does not exist at all, or whether it is a localparam.

There are two regression tests that rely on that only a warning is
generated, these have been updated to expect an error.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

elab_scope.cc

@@ -623,7 +623,7 @@ static void elaborate_scope_classes(Design*des, NetScope*scope,
       }
 }
 
-static void replace_scope_parameters(NetScope*scope, const LineInfo&loc,
+static void replace_scope_parameters(Design *des, NetScope*scope, const LineInfo&loc,
 				     const Module::replace_t&replacements)
 {
       if (debug_scopes) {
@@ -649,13 +649,7 @@ static void replace_scope_parameters(NetScope*scope, const LineInfo&loc,
 		  cerr << loc.get_fileline() << ":      : "
 		       << "Type=" << val->expr_type() << endl;
 	    }
-	    bool flag = scope->replace_parameter((*cur).first, val,
-                                                 scope->parent());
-	    if (! flag) {
-		  cerr << val->get_fileline() << ": warning: parameter "
-		       << (*cur).first << " not found in "
-		       << scope_path(scope) << "." << endl;
-	    }
+	    scope->replace_parameter(des, (*cur).first, val, scope->parent());
       }
 }
 
@@ -818,7 +812,7 @@ bool Module::elaborate_scope(Design*des, NetScope*scope,
 	// Run parameter replacements that were collected from the
 	// containing scope and meant for me.
 
-      replace_scope_parameters(scope, *this, replacements);
+      replace_scope_parameters(des, scope, *this, replacements);
 
       elaborate_scope_enumerations(des, scope, enum_sets);
 

ivtest/gold/br_gh157.gold

@@ -1,2 +1,2 @@
-./ivltests/br_gh157.v:13: warning: parameter x not found in test.dut.
-2
+./ivltests/br_gh157.v:13: error: Cannot override localparam `x` in `test.dut`.
+1 error(s) during elaboration.

ivtest/gold/pr498b.gold

@@ -0,0 +1,2 @@
+./ivltests/pr498b.v:23: error: parameter `foo` not found in `main`.
+1 error(s) during elaboration.

ivtest/ivltests/pr498a.v

@@ -20,7 +20,6 @@
 
 module main;
    test tt();
-   defparam foo = 3; /* This should generate a warning. */
    defparam tt.foo = 4;
 endmodule // main
 

ivtest/ivltests/pr498b.v

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2002 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
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+
+module main;
+   test tt();
+   defparam foo = 3; /* This should generate an error. */
+endmodule // main
+
+module test;
+   parameter foo = 10;
+   reg [foo-1:0] bar;
+
+endmodule // test

ivtest/regress-ivl1.list

@@ -121,7 +121,7 @@ clog2			normal			ivltests
 clog2-signal		normal			ivltests
 param_vec		normal			ivltests
 param_vec2		normal			ivltests
-pr498			normal			ivltests
+pr498a			normal			ivltests
 pr721			normal			ivltests
 pr809			normal			ivltests
 pr809b			normal			ivltests

ivtest/regress-vlg.list

@@ -308,7 +308,7 @@ br_gh127e		normal			ivltests gold=br_gh127e.gold
 br_gh127f		normal			ivltests gold=br_gh127f.gold
 br_gh142		CE			ivltests
 br_gh152		CE			ivltests
-br_gh157		normal			ivltests gold=br_gh157.gold
+br_gh157		CE			ivltests gold=br_gh157.gold
 br_gh162		normal			ivltests
 br_gh163		CE			ivltests
 br_gh198		normal			ivltests gold=br_gh198.gold
@@ -736,6 +736,7 @@ pr445			normal			ivltests
 pr478			normal			ivltests
 pr487			normal			ivltests gold=pr487.gold
 pr492			normal			ivltests gold=pr492.gold
+pr498b			CE			ivltests gold=pr498b.gold
 pr508			normal			ivltests
 pr509			normal			ivltests
 pr509b			normal			ivltests

net_design.cc

@@ -433,13 +433,7 @@ void NetScope::run_defparams(Design*des)
 		  continue;
 	    }
 
-	    bool flag = targ_scope->replace_parameter(perm_name, val, this);
-	    if (! flag) {
-		  cerr << val->get_fileline() << ": warning: parameter "
-		       << perm_name << " not found in "
-		       << scope_path(targ_scope) << "." << endl;
-	    }
-
+	    targ_scope->replace_parameter(des, perm_name, val, this);
       }
 
 	// If some of the defparams didn't find a scope in the name,
@@ -474,12 +468,7 @@ void NetScope::run_defparams_later(Design*des)
 		  continue;
 	    }
 
-	    bool flag = targ_scope->replace_parameter(name, val, this);
-	    if (! flag) {
-		  cerr << val->get_fileline() << ": warning: parameter "
-		       << name << " not found in "
-		       << scope_path(targ_scope) << "." << endl;
-	    }
+	    targ_scope->replace_parameter(des, name, val, this);
 
 	      // We'll need to re-evaluate parameters in this scope
 	    target_scopes.insert(targ_scope);

net_scope.cc

@@ -25,6 +25,7 @@
 # include  "netclass.h"
 # include  "netenum.h"
 # include  "netvector.h"
+# include  "PExpr.h"
 # include  "PPackage.h"
 # include  <cstring>
 # include  <cstdlib>
@@ -381,18 +382,27 @@ bool NetScope::auto_name(const char*prefix, char pad, const char* suffix)
  * Return false if the parameter does not already exist.
  * A parameter is not automatically created.
  */
-bool NetScope::replace_parameter(perm_string key, PExpr*val, NetScope*scope)
+void NetScope::replace_parameter(Design *des, perm_string key, PExpr*val, NetScope*scope)
 {
-      if (parameters.find(key) == parameters.end())
-	    return false;
+      if (parameters.find(key) == parameters.end()) {
+	    cerr << val->get_fileline() << ": error: parameter `"
+	         << key << "` not found in `"
+	         << scope_path(this) << "`." << endl;
+	    des->errors++;
+	    return;
+      }
 
       param_expr_t&ref = parameters[key];
-      if (ref.local_flag)
-	    return false;
+      if (ref.local_flag) {
+	    cerr << val->get_fileline() << ": error: "
+	         << "Cannot override localparam `" << key << "` in `"
+	         << scope_path(this) << "`." << endl;
+	    des->errors++;
+	    return;
+      }
 
       ref.val_expr = val;
       ref.val_scope = scope;
-      return true;
 }
 
 bool NetScope::make_parameter_unannotatable(perm_string key)

netlist.h

@@ -983,7 +983,7 @@ class NetScope : public Definitions, public Attrib {
 	   expression with a new expression, without affecting the
 	   range or signed_flag. Return false if the name does not
 	   exist. */
-      bool replace_parameter(perm_string name, PExpr*val, NetScope*scope);
+      void replace_parameter(Design *des, perm_string name, PExpr*val, NetScope*scope);
 
 	/* This is used to ensure the value of a parameter cannot be
 	   changed at run-time. This is required if a specparam is used