Support 'super'.

Changes

@@ -7,6 +7,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ***   Support $random and $urandom seeds.
 
+***   Support 'super'.
+
 ***   Support 'with item.index'.
 
 ***   Check for proper 'local' and 'protected' (#2228).

src/V3AstNodes.cpp

@@ -1180,6 +1180,9 @@ void AstClass::dump(std::ostream& str) const {
 }
 AstClass* AstClassExtends::classp() const {
     AstClassRefDType* refp = VN_CAST(dtypep(), ClassRefDType);
+    if (VL_UNLIKELY(!refp)) {  // LinkDot uses this for 'super.'
+        refp = VN_CAST(childDTypep(), ClassRefDType);
+    }
     UASSERT_OBJ(refp, this, "class extends non-ref");
     return refp->classp();
 }

src/V3LinkDot.cpp

@@ -2027,10 +2027,34 @@ private:
                 do {
                     classSymp = classSymp->parentp();
                 } while (classSymp && !VN_IS(classSymp->nodep(), Class));
-                m_ds.m_dotSymp = classSymp;
                 if (!classSymp) {
-                    nodep->v3error("'this' used outside class");
+                    nodep->v3error("'this' used outside class (IEEE 1800-2017 8.11)");
                     m_ds.m_dotErr = true;
+                } else {
+                    m_ds.m_dotSymp = classSymp;
+                    UINFO(8, "     this. " << m_ds.ascii() << endl);
+                }
+            } else if (VN_IS(nodep->lhsp(), ParseRef) && nodep->lhsp()->name() == "super") {
+                VSymEnt* classSymp = m_ds.m_dotSymp;
+                do {
+                    classSymp = classSymp->parentp();
+                } while (classSymp && !VN_IS(classSymp->nodep(), Class));
+                if (!classSymp) {
+                    nodep->v3error("'super' used outside class (IEEE 1800-2017 8.15)");
+                    m_ds.m_dotErr = true;
+                } else {
+                    auto classp = VN_CAST(classSymp->nodep(), Class);
+                    if (!classp->extendsp()) {
+                        nodep->v3error("'super' used on non-extended class (IEEE 1800-2017 8.15)");
+                        m_ds.m_dotErr = true;
+                    } else {
+                        auto cextp = VN_CAST(classp->extendsp(), ClassExtends);
+                        UASSERT_OBJ(cextp, nodep, "Bad super extends link");
+                        auto classp = cextp->classp();
+                        UASSERT_OBJ(classp, nodep, "Bad superclass");
+                        m_ds.m_dotSymp = m_statep->getNodeSym(classp);
+                        UINFO(8, "     super. " << m_ds.ascii() << endl);
+                    }
                 }
             } else if (VN_IS(nodep->lhsp(), ClassOrPackageRef)) {
                 // m_ds.m_dotText communicates the cell prefix between stages
@@ -2504,6 +2528,7 @@ private:
     virtual void visit(AstNodeFTaskRef* nodep) override {
         if (nodep->user3SetOnce()) return;
         UINFO(8, "     " << nodep << endl);
+        UINFO(8, "     " << m_ds.ascii() << endl);
         if (m_ds.m_dotp && m_ds.m_dotPos == DP_PACKAGE) {
             UASSERT_OBJ(VN_IS(m_ds.m_dotp->lhsp(), ClassOrPackageRef), m_ds.m_dotp->lhsp(),
                         "Bad package link");
@@ -2558,12 +2583,15 @@ private:
         } else {
             string baddot;
             VSymEnt* okSymp = nullptr;
-            VSymEnt* dotSymp = m_curSymp;  // Start search at module, as a variable
+            VSymEnt* dotSymp = nodep->dotted().empty()
+                                   ? m_ds.m_dotSymp  // Non-'super.' dotted reference
+                                   : m_curSymp;  // Start search at dotted point
             // of same name under a subtask isn't a relevant hit however a
             // function under a begin/end is.  So we want begins, but not
             // the function
             if (nodep->classOrPackagep()) {  // Look only in specified package
                 dotSymp = m_statep->getNodeSym(nodep->classOrPackagep());
+                UINFO(8, "    Override classOrPackage " << dotSymp << endl);
             } else {
                 if (nodep->inlinedDots() != "") {  // Correct for current scope
                     // Dotted lookup is always relative to module, as maybe

test_regress/t/t_class_extends_this.out

@@ -1,25 +0,0 @@
-%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: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

@@ -11,13 +11,11 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 
 compile(
-    fails => $Self->{vlt_all},
-    expect_filename => $Self->{golden_filename},
     );
 
 execute(
     check_finished => 1,
-    ) if !$Self->{vlt_all};
+    );
 
 ok(1);
 1;

test_regress/t/t_class_extends_this.v

@@ -11,20 +11,27 @@ class Base;
    function void test;
       if (value != 1) $stop;
       if (this.value != 1) $stop;
+      value = 2;
+      if (value != 2) $stop;
+      this.value = 3;
+      if (value != 3) $stop;
    endfunction
 endclass
 
 class Cls extends Base;
-   int value = 2;
+   int value = 20;
    function void test;
-      if (value != 2) $stop;
-      if (this.value != 2) $stop;
+      if (value != 20) $stop;
+      if (this.value != 20) $stop;
       if (super.value != 1) $stop;
+
       super.test();
-      super.value = 10;
-      this.value = 20;
-      if (super.value != 10) $stop;
-      if (value != 20) $stop;;
+      if (this.value != 20) $stop;
+
+      super.value = 9;
+      this.value = 29;
+      if (super.value != 9) $stop;
+      if (value != 29) $stop;;
    endfunction
 endclass
 

test_regress/t/t_class_super_bad.out

@@ -0,0 +1,4 @@
+%Error: t/t_class_super_bad.v:15:12: 'super' used outside class (IEEE 1800-2017 8.15)
+   15 |       super.addr = 2;
+      |            ^
+%Error: Exiting due to

test_regress/t/t_class_super_bad.pl

@@ -0,0 +1,19 @@
+#!/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(linter => 1);
+
+compile(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_super_bad.v

@@ -0,0 +1,19 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2020 Rafal Kapuscik
+// SPDX-License-Identifier: CC0-1.0
+//
+
+module t(/*AUTOARG*/
+   // Inputs
+   clk
+   );
+   input clk;
+   bit [3:0] addr;
+   initial begin
+      super.addr = 2;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_class_super_bad2.out

@@ -0,0 +1,4 @@
+%Error: t/t_class_super_bad2.v:10:12: 'super' used on non-extended class (IEEE 1800-2017 8.15)
+   10 |       super.i = 1;   
+      |            ^
+%Error: Exiting due to

test_regress/t/t_class_super_bad2.pl

@@ -0,0 +1,19 @@
+#!/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(linter => 1);
+
+compile(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_super_bad2.v

@@ -0,0 +1,12 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2020 Rafal Kapuscik
+// SPDX-License-Identifier: CC0-1.0
+//
+
+class Cls;
+   task t;
+      super.i = 1;  // Bad - no extends
+   endtask
+endclass

test_regress/t/t_class_uses_this_bad.out

@@ -1,4 +1,4 @@
-%Error: t/t_class_uses_this_bad.v:15:12: 'this' used outside class
+%Error: t/t_class_uses_this_bad.v:15:12: 'this' used outside class (IEEE 1800-2017 8.11)
    15 |        this.addr = 2;
       |            ^
 %Error: Exiting due to

test_regress/t/t_interface2.v

@@ -104,6 +104,10 @@ module counter_nansi(clkm, c_data, i_value);
 endmodule : counter_nansi
 `endif
 
+// Test uses Verilator --top-module, which means this isn't in the hierarchy
+// Other simulators will see it, and is illegal to have unconnected interface
+`ifdef VERILATOR
 module modunused (ifunused ifinunused);
    ifunused ifunused();
 endmodule
+`endif