From 04eabc62feaf7fd502cb09e31de819cf877547e7 Mon Sep 17 00:00:00 2001
From: Edmund Lam <elam@hudson-trading.com>
Date: Tue, 9 Jun 2026 13:07:17 -0400
Subject: [PATCH] descend into dots in typedefs

---
 test_regress/t/t_class_lparam_iface_chain.v   |  4 +-
 test_regress/t/t_class_lparam_typedef_chain.v | 43 ++++++++++++++++++-
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/test_regress/t/t_class_lparam_iface_chain.v b/test_regress/t/t_class_lparam_iface_chain.v
index 39444fbf5..5395f3bf9 100644
--- a/test_regress/t/t_class_lparam_iface_chain.v
+++ b/test_regress/t/t_class_lparam_iface_chain.v
@@ -21,7 +21,7 @@ interface SubIface #(
   logic [IW-1:0] data;
 endinterface
 
-// Module that takes an interface port — must elaborate after the iface
+// Module that takes an interface port - must elaborate after the iface
 // cell pin is fully constified.
 module Consumer (
     SubIface si
@@ -50,7 +50,7 @@ module t;
   SubIface #(b8_alias) i_chain ();
   // Iface pin = expression mixing deferred lparams
   SubIface #(b8 + b13) i_expr ();
-  // Iface used as a module port — exercises the iface-cell-first path
+  // Iface used as a module port - exercises the iface-cell-first path
   Consumer cons (.si(i_bare));
 
   initial begin
diff --git a/test_regress/t/t_class_lparam_typedef_chain.v b/test_regress/t/t_class_lparam_typedef_chain.v
index c8ec879f8..aa4039514 100644
--- a/test_regress/t/t_class_lparam_typedef_chain.v
+++ b/test_regress/t/t_class_lparam_typedef_chain.v
@@ -2,10 +2,13 @@
 //
 // Typedefs and class type parameters that resolve through a
 // class-scope-resolved localparam (typedef alias of a parameterized
-// class, e.g. inst::b). Exercises three sub-cases:
+// class, e.g. inst::b). Exercises four sub-cases:
 //   - Deferred lparam used as a packed range bound in a typedef
 //   - Deferred lparam used as a value argument to a parameterized class
 //   - Class-scope-resolved typedef that itself depends on the param
+//   - Class-scope Dot used DIRECTLY (no intermediate lparam) in a typedef
+//     range inside a parameterized module, consumed by `$bits` on a child
+//     cell pin
 //
 // This file ONLY is placed under the Creative Commons Public Domain.
 // SPDX-FileCopyrightText: 2026 Wilson Snyder
@@ -16,13 +19,44 @@
 `define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0)
 // verilog_format: on
 
+// Sink for sub-case (4): the BITS pin consumes $bits of a typedef whose
+// packed range uses class-scope Dots. V3Param must descend into the typedef's
+// subDType and resolve those Dots, otherwise V3Width emits "dotted expressions
+// in parameters".
+module Sink #(
+    parameter int BITS = 1
+) ();
+  logic [BITS-1:0] data;
+endmodule
+
+// Parameterized wrapper so the class specialization is deferred until V3Param
+// processes the cell instance.
+module Sub #(
+    parameter int W = 8
+) ();
+  // Inner class — same shape as `t`'s C, repeated here to keep sub-case (4)
+  // self-contained inside Sub.
+  virtual class CInner #(
+      parameter int a
+  );
+    localparam int b = a;
+  endclass
+
+  typedef CInner#(W) CFG;
+
+  // (4) typedef packed range uses class-scope Dots directly
+  typedef logic [(CFG::b + CFG::b - 1):0] dot_range_t;
+
+  Sink #(.BITS($bits(dot_range_t))) u_sink ();
+endmodule
+
 module t;
   virtual class C #(
       parameter int a
   );
     localparam int b = a;
     typedef logic [a-1:0] inner_t;
-    // localparam derived from a typedef inside the same class —
+    // localparam derived from a typedef inside the same class -
     // resolveDotToTypedef must constify this when reached via CFG::width.
     localparam int width = $bits(inner_t);
   endclass
@@ -46,6 +80,9 @@ module t;
   // Wire whose range comes from a deferred lparam
   logic [b8-1:0] wide_bus;
 
+  // (4) parameterized wrapper with a typedef range using class Dots directly
+  Sub #(.W(8)) u_sub ();
+
   initial begin
     `checkh(b8, 32'd8);
     `checkh(from_def_b, 32'd8);
@@ -54,6 +91,8 @@ module t;
     `checkh(data_value, 8'hff);
     wide_bus = '1;
     `checkh(wide_bus, 8'hff);
+    // sub-case (4): $bits(dot_range_t) = CFG::b + CFG::b = 8 + 8 = 16
+    `checkh($bits(u_sub.u_sink.data), 32'd16);
     $write("*-* All Finished *-*\n");
     $finish;
   end