Fix $bits on local struct with chained-interface (#7515) (#7517)

src/V3Param.cpp

@@ -875,6 +875,18 @@ class ParamProcessor final {
                 }
                 return true;
             }
+        } else if (!entry.cloneCellPath.empty()) {
+            // Clone entry has no paramTypep stored; look up the type by name.
+            if (AstParamTypeDType* const ptp
+                = V3LinkDotIfaceCapture::findParamTypeInModule(targetModp, entry.refp->name())) {
+                entry.refp->refDTypep(ptp);
+                entry.refp->dtypep(ptp);
+                for (AstRefDType* const xrefp : entry.extraRefps) {
+                    xrefp->refDTypep(ptp);
+                    xrefp->dtypep(ptp);
+                }
+                return true;
+            }
         }
         return false;
     }

test_regress/t/t_iface_chained_consumer_struct.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# 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-FileCopyrightText: 2026 Wilson Snyder
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=["--binary"])
+
+test.execute()
+
+test.passes()

test_regress/t/t_iface_chained_consumer_struct.v

@@ -0,0 +1,57 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Wilson Snyder
+// SPDX-License-Identifier: CC0-1.0
+
+// Two-level interface chain.  Inner interface has a typedef that
+// depends on its parameter.  Mid interface aliases that typedef.
+// A module aliases the alias and uses it in a packed struct, then
+// passes $bits(struct) to a width-parameterized child.  All widths
+// must use the override value, not the template default.
+
+interface inner_if #(parameter int N = 1) ();
+  typedef logic [$clog2(N)-1:0] id_t;
+endinterface
+
+interface mid_if #(parameter int N = 1) ();
+  inner_if #(.N(N)) inner();
+  typedef inner.id_t id_t;
+endinterface
+
+module sink #(parameter int W = 1) (input logic [W-1:0] dat_i);
+endmodule
+
+module dut #(parameter int N = 1) ();
+  mid_if #(.N(N)) m();
+  typedef m.id_t id_t;
+  typedef struct packed {
+    id_t id;
+    logic [7:0] payload;
+  } pkt_t;
+  pkt_t pkt_var;
+  localparam int W = $bits(pkt_t);
+  sink #(.W(W)) s(.dat_i(pkt_var));
+endmodule
+
+module t;
+  // N=8 gives id_t = 3 bits, so pkt_t = 3 + 8 = 11 bits.
+  dut #(.N(8)) u();
+
+  initial begin
+    if (u.W !== 11) begin
+      $display("%%Error: u.W=%0d expected 11", u.W);
+      $stop;
+    end
+    if ($bits(u.pkt_var) !== 11) begin
+      $display("%%Error: $bits(u.pkt_var)=%0d expected 11", $bits(u.pkt_var));
+      $stop;
+    end
+    if ($bits(u.s.dat_i) !== 11) begin
+      $display("%%Error: $bits(u.s.dat_i)=%0d expected 11", $bits(u.s.dat_i));
+      $stop;
+    end
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_paramgraph_comined_iface_stats.py

@@ -23,7 +23,7 @@ test.file_grep(test.stats, r'IfaceCapture, Entries template\s+(\d+)', 8)
 test.file_grep(test.stats, r'IfaceCapture, Entries cloned\s+(\d+)', 10)
 test.file_grep(test.stats, r'IfaceCapture, Ledger fixups in V3Param\s+(\d+)', 8)
 test.file_grep(test.stats, r'IfaceCapture, Wrong-clone refs fixed\s+(\d+)', 10)
-test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 2)
+test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 0)
 
 test.execute()
 

test_regress/t/t_paramgraph_iface_template_nested_stats.py

@@ -23,7 +23,7 @@ test.file_grep(test.stats, r'IfaceCapture, Entries template\s+(\d+)', 11)
 test.file_grep(test.stats, r'IfaceCapture, Entries cloned\s+(\d+)', 14)
 test.file_grep(test.stats, r'IfaceCapture, Ledger fixups in V3Param\s+(\d+)', 5)
 test.file_grep(test.stats, r'IfaceCapture, Wrong-clone refs fixed\s+(\d+)', 10)
-test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 2)
+test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 0)
 
 test.execute()
 

test_regress/t/t_paramgraph_nested_iface_typedef_stats.py

@@ -23,7 +23,7 @@ test.file_grep(test.stats, r'IfaceCapture, Entries template\s+(\d+)', 8)
 test.file_grep(test.stats, r'IfaceCapture, Entries cloned\s+(\d+)', 12)
 test.file_grep(test.stats, r'IfaceCapture, Ledger fixups in V3Param\s+(\d+)', 8)
 test.file_grep(test.stats, r'IfaceCapture, Wrong-clone refs fixed\s+(\d+)', 14)
-test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 4)
+test.file_grep(test.stats, r'IfaceCapture, Dead refs fixed in modules\s+(\d+)', 0)
 
 test.execute()