Add error when use parameters without value, bug1424.

Changes

@@ -6,6 +6,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Support '#' comments in $readmem, bug1411. [Frederick Requin]
 
+****  Add error when use parameters without value, bug1424. [Peter Gerst]
+
 ****  Fix missing VL_SHIFTL_ errors, bug1412, bug1415. [Larry Lee]
 
 ****  Fix MinGW GCC 6 printf formats, bug1413. [Sergey Kvachonok]

src/V3Param.cpp

@@ -271,21 +271,29 @@ private:
 
     // Make sure all parameters are constantified
     virtual void visit(AstVar* nodep) {
-	if (!nodep->user5SetOnce()) {  // Process once
+        if (!nodep->user5SetOnce()) {  // Process once
             iterateChildren(nodep);
-	    if (nodep->isParam()) {
+            if (nodep->isParam()) {
-		if (!nodep->valuep()) { nodep->v3fatalSrc("Parameter without initial value"); }
+                if (!nodep->valuep()) {
-		V3Const::constifyParamsEdit(nodep);  // The variable, not just the var->init()
+                    nodep->v3error("Parameter without initial value is never given value"
-                if (!VN_IS(nodep->valuep(), Const)) {  // Complex init, like an array
+                                   <<" (IEEE 1800-2017 6.20.1): "
-		    // Make a new INITIAL to set the value.
+                                   <<nodep->prettyName());
-		    // This allows the normal array/struct handling code to properly initialize the parameter
+                } else {
-		    nodep->addNext(new AstInitial(nodep->fileline(),
+                    V3Const::constifyParamsEdit(nodep);  // The variable, not just the var->init()
-						  new AstAssign(nodep->fileline(),
+                    if (!VN_IS(nodep->valuep(), Const)) {  // Complex init, like an array
-								new AstVarRef(nodep->fileline(), nodep, true),
+                        // Make a new INITIAL to set the value.
-								nodep->valuep()->cloneTree(true))));
+                        // This allows the normal array/struct handling code to properly
-		}
+			// initialize the parameter.
-	    }
+                        nodep->addNext(
-	}
+                            new AstInitial(nodep->fileline(),
+                                           new AstAssign(
+                                               nodep->fileline(),
+                                               new AstVarRef(nodep->fileline(), nodep, true),
+                                               nodep->valuep()->cloneTree(true))));
+                    }
+                }
+            }
+        }
     }
     // Make sure varrefs cause vars to constify before things above
     virtual void visit(AstVarRef* nodep) {

src/verilog.y

@@ -2085,7 +2085,9 @@ param_assignment<varp>:		// ==IEEE: param_assignment
 		id/*new-parameter*/ variable_dimensionListE sigAttrListE '=' exprOrDataType
 	/**/		{ $$ = VARDONEA($<fl>1,*$1, $2, $3); $$->valuep($5); }
 	|	id/*new-parameter*/ variable_dimensionListE sigAttrListE
-	/**/		{ $$ = VARDONEA($<fl>1,*$1, $2, $3); }
+	/**/		{ $$ = VARDONEA($<fl>1,*$1, $2, $3);
+		          if ($<fl>1->language() < V3LangCode::L1800_2009) {
+			     $<fl>1->v3error("Parameter requires default value, or use IEEE 1800-2009 or later."); } }
 	;
 
 list_of_param_assignments<varp>:	// ==IEEE: list_of_param_assignments

test_regress/t/t_param_default_bad.out

@@ -0,0 +1,2 @@
+%Error: t/t_param_default_bad.v:6: Parameter without initial value is never given value (IEEE 1800-2017 6.20.1): Foo
+%Error: Exiting due to

test_regress/t/t_param_default_bad.pl

@@ -7,15 +7,13 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
-scenarios(simulator => 1);
+scenarios(vlt => 1);
 
 compile(
-     fails => 1,
+    v_flags2 => ["--lint-only"],
-     expect =>
+    fails => 1,
-'%Error: Internal Error: t/t_param_default_bad.v:6: ../V3Param.cpp:\d+: Parameter without initial value
+    expect_filename => $Self->{golden_filename},
-%Error: Internal Error: See the manual and http://www.veripool.org/verilator for more assistance.
+    );
-.*%Error: Command Failed.*',
-     );
 
 ok(1);
 1;

test_regress/t/t_param_default_presv_bad.out

@@ -0,0 +1,2 @@
+%Error: t/t_param_default_bad.v:6: Parameter requires default value, or use IEEE 1800-2009 or later.
+%Error: Exiting due to

test_regress/t/t_param_default_presv_bad.pl

@@ -0,0 +1,21 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(vlt => 1);
+
+top_filename("t/t_param_default_bad.v");
+
+compile(
+    v_flags2 => ["--lint-only --language 1800-2005"],
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;