Fix duplicate name error with interface initial blocks (#6804) (#6805).

Changes

@@ -109,6 +109,7 @@ Verilator 5.043 devel
 * Fix input sampling of clocking block signals (#6788). [Pawel Kojma, Antmicro Ltd.]
 * Fix O(n*2) analysis in const-bit-op-tree (#6791). [Geza Lore]
 * Fix nested struct within parameter port list (#6818) (#6824). [Luca Colagrande]
+* Fix duplicate name error with interface initial blocks (#6804) (#6805). [Thomas Dybdahl Ahle]
 
 
 Verilator 5.042 2025-11-02

docs/CONTRIBUTORS

@@ -233,6 +233,7 @@ Steven Hugg
 Szymon Gizler
 Sören Tempel
 Teng Huang
+Thomas Dybdahl Ahle
 Tim Hutt
 Tim Snyder
 Tobias Jensen

src/V3MemberMap.h

@@ -101,6 +101,9 @@ private:
         }
     }
     void memberInsert(MemberMap& mmapr, AstNode* childp, bool warn = true) {
+        // Skip nodes without names (e.g., initial blocks, anonymous statements)
+        // These can't be looked up by name anyway
+        if (childp->name().empty()) return;
         const auto mitPair = mmapr.emplace(childp->name(), childp);
         if (VL_UNCOVERABLE(!mitPair.second && warn)) {
             // Probably an internal error, but we'll make it user friendly if happens

test_regress/t/t_interface_initial.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 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
+
+import vltest_bootstrap
+
+test.scenarios('linter')
+test.top_filename = "t/t_interface_initial.v"
+
+test.lint()
+
+test.passes()

test_regress/t/t_interface_initial.v

@@ -0,0 +1,35 @@
+// DESCRIPTION: Verilator: Test interface with multiple initial blocks
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+// Test that interfaces with multiple initial blocks don't cause
+// "Duplicate declaration of member name: ''" errors when a method
+// is called on the interface (which triggers VMemberMap::findMember).
+// Initial blocks have empty names, so the member map should skip them.
+
+interface my_iface;
+  int value;
+
+  // Multiple initial blocks (anonymous - have empty names)
+  initial value = 0;
+  initial $display("Init 1");
+  initial $display("Init 2");
+
+  // A method that can be called to trigger member map lookup
+  function int get_value();
+    return value;
+  endfunction
+endinterface
+
+module t;
+  my_iface iface ();
+
+  initial begin
+    // This method call triggers VMemberMap::findMember on the interface
+    if (iface.get_value() !== 0) $stop;
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule