Parser: Move unsupported error detection of 'this'/'super' down into link stage

src/V3LinkDot.cpp

@@ -2033,6 +2033,14 @@ private:
             m_ds.init(m_curSymp);
             // Note m_ds.m_dot remains NULL; this is a reference not under a dot
         }
+        if (nodep->name() == "this") {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: this");
+            m_ds.m_dotErr = true;
+        }
+        else if (nodep->name() == "super") {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: super");
+            m_ds.m_dotErr = true;
+        }
         if (m_ds.m_dotPos == DP_MEMBER) {
             // Found a Var, everything following is membership.  {scope}.{var}.HERE {member}
             AstNode* varEtcp = m_ds.m_dotp->lhsp()->unlinkFrBack();

src/verilog.y

@@ -3432,7 +3432,7 @@ task_subroutine_callNoMethod<nodep>:	// function_subroutine_callNoMethod (as tas
 	//			// funcref below not task ref to avoid conflict, must later handle either
 	|	funcRef yWITH__PAREN '(' expr ')'	{ $$ = $1; BBUNSUP($2, "Unsupported: 'with' on task call"); }
 	//			// can call as method and yWITH without parenthesis
-	|	id yWITH__PAREN '(' expr ')'		{ $$ = new AstFuncRef($<fl>1, *$1, NULL); BBUNSUP($2, "Unsupported: 'with' on function call"); }
+	|	id yWITH__PAREN '(' expr ')'		{ $$ = new AstFuncRef($<fl>1, *$1, NULL); BBUNSUP($2, "Unsupported: 'with' on task call"); }
 	|	system_t_call				{ $$ = $1; }
 	//			// IEEE: method_call requires a "." so is in expr
 	//			// IEEE: ['std::'] not needed, as normal std package resolution will find it
@@ -3454,7 +3454,7 @@ function_subroutine_callNoMethod<nodep>:	// IEEE: function_subroutine_call (as f
 	//			// IEEE: randomize_call
 	//			// We implement randomize as a normal funcRef, since randomize isn't a keyword
 	//			// Note yNULL is already part of expressions, so they come for free
-	|	funcRef yWITH__CUR constraint_block	{ $$ = $1; BBUNSUP($2, "Unsupported: randomize() 'with'"); }
+	|	funcRef yWITH__CUR constraint_block	{ $$ = $1; BBUNSUP($2, "Unsupported: randomize() 'with' constraint"); }
 	|	funcRef yWITH__CUR '{' '}'		{ $$ = $1; BBUNSUP($2, "Unsupported: randomize() 'with'"); }
 	;
 
@@ -4250,8 +4250,7 @@ exprScope<nodep>:		// scope and variable for use to inside an expression
 	//			// IEEE: [ implicit_class_handle . | class_scope | package_scope ] hierarchical_identifier select
 	//			// Or method_call_body without parenthesis
 	//			// See also varRefClassBit, which is the non-expr version of most of this
-		yTHIS					{ $$ = new AstConst($1, AstConst::LogicFalse());
+		yTHIS					{ $$ = new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "this"); }
-							  BBUNSUP($1, "Unsupported: this"); }
 	|	yD_ROOT					{ $$ = new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "$root"); }
 	|	idArrayed				{ $$ = $1; }
 	|	packageClassScope idArrayed		{ $$ = AstDot::newIfPkg($2->fileline(), CAST_PACKAGE_CLASS($1), $2); }
@@ -4259,8 +4258,7 @@ exprScope<nodep>:		// scope and variable for use to inside an expression
 	//			// expr below must be a "yTHIS"
 	|	~l~expr '.' ySUPER			{ $$ = $1; BBUNSUP($3, "Unsupported: super"); }
 	//			// Part of implicit_class_handle
-	|	ySUPER					{ $$ = new AstConst($1, AstConst::LogicFalse());
+	|	ySUPER					{ $$ = new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "super"); }
-							  BBUNSUP($1, "Unsupported: super"); }
 	;
 
 fexprScope<nodep>:		// exprScope, For use as first part of statement (disambiguates <=)
@@ -4728,8 +4726,10 @@ variable_lvalueConcList<nodep>:	// IEEE: part of variable_lvalue: '{' variable_l
 idClassSel<nodep>:			// Misc Ref to dotted, and/or arrayed, and/or bit-ranged variable
 		idDotted				{ $$ = $1; }
 	//			// IEEE: [ implicit_class_handle . | package_scope ] hierarchical_variable_identifier select
-	|	yTHIS '.' idDotted			{ $$ = $3; BBUNSUP($1, "Unsupported: this"); }
+	|	yTHIS '.' idDotted
-	|	ySUPER '.' idDotted			{ $$ = $3; BBUNSUP($1, "Unsupported: super"); }
+			{ $$ = new AstDot($2, false, new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "this"), $3); }
+	|	ySUPER '.' idDotted
+			{ $$ = new AstDot($2, false, new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "super"), $3); }
 	|	yTHIS '.' ySUPER '.' idDotted		{ $$ = $5; BBUNSUP($1, "Unsupported: this.super"); }
 	//			// Expanded: package_scope idDotted
 	|	packageClassScope idDotted		{ $$ = $2; BBUNSUP($2, "Unsupported: package scoped id"); }
@@ -4738,8 +4738,10 @@ idClassSel<nodep>:			// Misc Ref to dotted, and/or arrayed, and/or bit-ranged va
 idClassSelForeach<nodep>:
 		idDottedForeach				{ $$ = $1; }
 	//			// IEEE: [ implicit_class_handle . | package_scope ] hierarchical_variable_identifier select
-	|	yTHIS '.' idDottedForeach		{ $$ = $3; BBUNSUP($1, "Unsupported: this"); }
+	|	yTHIS '.' idDottedForeach
-	|	ySUPER '.' idDottedForeach		{ $$ = $3; BBUNSUP($1, "Unsupported: super"); }
+			{ $$ = new AstDot($2, false, new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "this"), $3); }
+	|	ySUPER '.' idDottedForeach
+			{ $$ = new AstDot($2, false, new AstParseRef($<fl>1, VParseRefExp::PX_ROOT, "super"), $3); }
 	|	yTHIS '.' ySUPER '.' idDottedForeach	{ $$ = $5; BBUNSUP($1, "Unsupported: this.super"); }
 	//			// Expanded: package_scope idForeach
 	|	packageClassScope idDottedForeach	{ $$ = $2; BBUNSUP($2, "Unsupported: package/class scoped id"); }

test_regress/t/t_class_extends_this.out

@@ -0,0 +1,49 @@
+%Error-UNSUPPORTED: t/t_class_extends_this.v:13:11: Unsupported: this
+   13 |       if (this.value != 1) $stop;
+      |           ^~~~
+%Error: t/t_class_extends_this.v:13:11: Can't find definition of scope/variable: 'this'
+   13 |       if (this.value != 1) $stop;
+      |           ^~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:17:19: Unsupported: class extends
+   17 | class Cls extends Base;
+      |                   ^~~~
+%Error: t/t_class_extends_this.v:17:19: Found definition of 'Base' as a CLASS but expected a variable
+   17 | class Cls extends Base;
+      |                   ^~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:21:11: Unsupported: this
+   21 |       if (this.value != 2) $stop;
+      |           ^~~~
+%Error: t/t_class_extends_this.v:21:11: Can't find definition of scope/variable: 'this'
+   21 |       if (this.value != 2) $stop;
+      |           ^~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:22:11: Unsupported: super
+   22 |       if (super.value != 1) $stop;
+      |           ^~~~~
+%Error: t/t_class_extends_this.v:22:11: Can't find definition of scope/variable: 'super'
+   22 |       if (super.value != 1) $stop;
+      |           ^~~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:23:7: Unsupported: super
+   23 |       super.test();
+      |       ^~~~~
+%Error: t/t_class_extends_this.v:23:7: Can't find definition of scope/variable: 'super'
+   23 |       super.test();
+      |       ^~~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:24:7: Unsupported: super
+   24 |       super.value = 10;
+      |       ^~~~~
+%Error: t/t_class_extends_this.v:24:7: Can't find definition of scope/variable: 'super'
+   24 |       super.value = 10;
+      |       ^~~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:25:7: Unsupported: this
+   25 |       this.value = 20;
+      |       ^~~~
+%Error: t/t_class_extends_this.v:25:7: Can't find definition of scope/variable: 'this'
+   25 |       this.value = 20;
+      |       ^~~~
+%Error-UNSUPPORTED: t/t_class_extends_this.v:26:11: Unsupported: super
+   26 |       if (super.value != 10) $stop;
+      |           ^~~~~
+%Error: t/t_class_extends_this.v:26:11: Can't find definition of scope/variable: 'super'
+   26 |       if (super.value != 10) $stop;
+      |           ^~~~~
+%Error: Exiting due to

test_regress/t/t_class_extends_this.pl

@@ -0,0 +1,23 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2020 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.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+scenarios(simulator => 1);
+
+compile(
+    fails => $Self->{vlt_all},
+    expect_filename => $Self->{golden_filename},
+    );
+
+#execute(
+#    check_finished => 1,
+#    );
+
+ok(1);
+1;

test_regress/t/t_class_extends_this.v

@@ -0,0 +1,39 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2020 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+typedef class Cls;
+
+class Base;
+   int value = 1;
+   function void test;
+      if (value != 1) $stop;
+      if (this.value != 1) $stop;
+   endfunction
+endclass
+
+class Cls extends Base;
+   int value = 2;
+   function void test;
+      if (value != 2) $stop;
+      if (this.value != 2) $stop;
+      if (super.value != 1) $stop;
+      super.test();
+      super.value = 10;
+      this.value = 20;
+      if (super.value != 10) $stop;
+      if (value != 20) $stop;;
+   endfunction
+endclass
+
+module t (/*AUTOARG*/);
+   initial begin
+      Cls c;
+      c = new;
+      c.test();
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_with_unsup.out

@@ -7,7 +7,7 @@
 %Error-UNSUPPORTED: t/t_with_unsup.v:24:28: Unsupported: 'with' on function call
    24 |       found = aliases.find with (item == i);
       |                            ^~~~
-%Error-UNSUPPORTED: t/t_with_unsup.v:25:20: Unsupported: 'with' on function call
+%Error-UNSUPPORTED: t/t_with_unsup.v:25:20: Unsupported: 'with' on task call
    25 |       aliases.find with (item == i);
       |                    ^~~~
 %Error-UNSUPPORTED: t/t_with_unsup.v:29:36: Unsupported: 'with' on method call