Support class extending its parameter (#3904)

src/V3LinkDot.cpp

@@ -3174,20 +3174,46 @@ private:
                         cextp->v3error("Attempting to extend using non-class");  // LCOV_EXCL_LINE
                     } else {
                         VSymEnt* const foundp = m_curSymp->findIdFallback(cpackagerefp->name());
-                        bool ok = false;
                         if (foundp) {
-                            if (AstClass* const classp = VN_CAST(foundp->nodep(), Class)) {
+                            AstClassRefDType* classRefDtypep = nullptr;
+                            AstClass* classp = VN_CAST(foundp->nodep(), Class);
+                            if (classp) {
+                                AstPin* paramsp = cpackagerefp->paramsp();
+                                if (paramsp) paramsp = paramsp->cloneTree(true);
+                                classRefDtypep
+                                    = new AstClassRefDType{nodep->fileline(), classp, paramsp};
+                            } else if (AstParamTypeDType* const paramp
+                                       = VN_CAST(foundp->nodep(), ParamTypeDType)) {
+                                if (m_statep->forPrimary()) {
+                                    // Extending has to be handled after V3Param.cpp, but the type
+                                    // reference has to be visited
+                                    iterate(paramp);
+                                    return;
+                                } else {
+                                    AstNodeDType* const paramTypep = paramp->getChildDTypep();
+                                    classRefDtypep
+                                        = VN_CAST(paramTypep->cloneTree(false), ClassRefDType);
+                                    if (!classRefDtypep) {
+                                        paramTypep->v3error(
+                                            "Attempting to extend using non-class");
+                                    } else {
+                                        classp = classRefDtypep->classp();
+                                    }
+                                }
+                            } else {
+                                cextp->v3warn(E_UNSUPPORTED,
+                                              "Unsupported: " << foundp->nodep()->prettyTypeName()
+                                                              << " in AstClassExtends");
+                            }
+
+                            if (classp) {
                                 UINFO(8, "Import to " << nodep << " from export class " << classp
                                                       << endl);
                                 if (classp == nodep) {
                                     cextp->v3error("Attempting to extend class "
                                                    << nodep->prettyNameQ() << " from itself");
                                 } else {
-                                    AstPin* paramsp = cpackagerefp->paramsp();
+                                    cextp->childDTypep(classRefDtypep);
-                                    if (paramsp) paramsp = paramsp->cloneTree(true);
-                                    const auto newp
-                                        = new AstClassRefDType{nodep->fileline(), classp, paramsp};
-                                    cextp->childDTypep(newp);
                                     classp->isExtended(true);
                                     nodep->isExtended(true);
                                     VSymEnt* const srcp = m_statep->getNodeSym(classp);
@@ -3195,10 +3221,8 @@ private:
                                     VL_DO_DANGLING(cpackagerefp->unlinkFrBack()->deleteTree(),
                                                    cpackagerefp);
                                 }
-                                ok = true;
                             }
-                        }
+                        } else {
-                        if (!ok) {
                             const string suggest = m_statep->suggestSymFallback(
                                 m_curSymp, cpackagerefp->name(), LinkNodeMatcherClass{});
                             cpackagerefp->v3error(

test_regress/t/t_class_extends_alias_unsup.out

@@ -0,0 +1,5 @@
+%Error-UNSUPPORTED: t/t_class_extends_alias_unsup.v:22:22: Unsupported: TYPEDEF 'foo_t' in AstClassExtends
+   22 |    class bar extends foo_t;
+      |                      ^~~~~
+                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
+%Error: Exiting due to

test_regress/t/t_class_extends_alias_unsup.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 2023 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);
+
+lint(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_extends_alias_unsup.v

@@ -0,0 +1,38 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (/*AUTOARG*/
+   );
+
+   class foo;
+      int x = 1;
+      function int get_x;
+         return x;
+      endfunction
+      function int get_3;
+         return 3;
+      endfunction
+   endclass
+
+   typedef foo foo_t;
+
+   class bar extends foo_t;
+   endclass
+
+
+   bar bar_foo_t_i;
+
+   initial begin
+      bar_foo_t_i = new;
+      if (bar_foo_t_i.get_x() == 1 && bar_foo_t_i.get_3() == 3) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+      else begin
+         $stop;
+      end
+   end
+endmodule

test_regress/t/t_class_extends_aliased_real_bad.out

@@ -0,0 +1,5 @@
+%Error: t/t_class_extends_aliased_real_bad.v:14:10: Attempting to extend using non-class
+                                                  : ... In instance t
+   14 |    bar #(real_t) bar_real_t;
+      |          ^~~~~~
+%Error: Exiting due to

test_regress/t/t_class_extends_aliased_real_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 2023 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);
+
+lint(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_extends_aliased_real_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, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (/*AUTOARG*/);
+
+   class bar #(type T) extends T;
+   endclass
+
+   typedef real real_t;
+
+   bar #(real_t) bar_real_t;
+
+   initial begin
+      $stop;
+   end
+endmodule

test_regress/t/t_class_extends_int_param_bad.out

@@ -0,0 +1,5 @@
+%Error: t/t_class_extends_int_param_bad.v:9:23: Attempting to extend using non-class
+                                              : ... In instance t
+    9 |    class bar #(type T=int) extends T;
+      |                       ^~~
+%Error: Exiting due to

test_regress/t/t_class_extends_int_param_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 2023 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);
+
+lint(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_class_extends_int_param_bad.v

@@ -0,0 +1,15 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (/*AUTOARG*/);
+
+   class bar #(type T=int) extends T;
+   endclass
+
+   initial begin
+      $stop;
+   end
+endmodule

test_regress/t/t_class_extends_param.pl

@@ -0,0 +1,20 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2023 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();
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;

test_regress/t/t_class_extends_param.v

@@ -0,0 +1,48 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (/*AUTOARG*/
+   );
+
+   class foo;
+      int x = 1;
+      function int get_x;
+         return x;
+      endfunction
+      function int get_3;
+         return 3;
+      endfunction
+   endclass
+
+   class bar #(type T=foo) extends T;
+   endclass
+
+   class baz;
+      int x = 2;
+      function int get_x;
+         return x;
+      endfunction
+      function int get_4;
+         return 4;
+      endfunction
+   endclass
+
+   bar bar_foo_i;
+   bar #(baz) bar_baz_i;
+
+   initial begin
+      bar_foo_i = new;
+      bar_baz_i = new;
+      if (bar_foo_i.get_x() == 1 && bar_foo_i.get_3() == 3 &&
+          bar_baz_i.get_x() == 2 && bar_baz_i.get_4() == 4) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+      else begin
+         $stop;
+      end
+   end
+endmodule