more tests and fixes

src/V3Param.cpp

@@ -2178,6 +2178,50 @@ public:
         });
     }
 
+    // Resolve `class::member` Dots in `rootp`'s tree, and also in any deferred
+    // lparam reachable transitively through VarRefs from `rootp`. By V3Param
+    // time the surviving such Dots are paramed-class refs that need
+    // linkDotParamed for scope, but `resolveDotToTypedef` can handle the
+    // typedef-aliased subset inline. Resolving them here turns a deferred
+    // lparam's value into a Const so subsequent constify on `rootp` can fold
+    // expressions that reference the lparam.
+    // `modp` is the enclosing module — resolveDotToTypedef may call into
+    // classRefDeparam which needs m_modp set for level/recursion bookkeeping.
+    void resolveDeferredDotsReachableFrom(AstNode* rootp, AstNodeModule* modp) {
+        std::vector<AstDot*> dotps;
+        const auto& deferredVarps = v3Global.rootp()->deferredParamVarps();
+        std::set<AstVar*> reachedDeferred;
+        auto collectDots = [&](AstNode* p) {
+            p->foreach([&](AstDot* dotp) {
+                if (VN_IS(dotp->lhsp(), ClassOrPackageRef)) dotps.push_back(dotp);
+            });
+        };
+        std::vector<AstVar*> workVarps;
+        auto enqueueRefs = [&](AstNode* p) {
+            p->foreach([&](const AstVarRef* refp) {
+                AstVar* const refVarp = refp->varp();
+                if (refVarp && refVarp->varType() == VVarType::LPARAM
+                    && deferredVarps.count(refVarp) && reachedDeferred.insert(refVarp).second) {
+                    workVarps.push_back(refVarp);
+                }
+            });
+        };
+        collectDots(rootp);
+        enqueueRefs(rootp);
+        while (!workVarps.empty()) {
+            AstVar* const varp = workVarps.back();
+            workVarps.pop_back();
+            if (!varp->valuep()) continue;
+            collectDots(varp->valuep());
+            enqueueRefs(varp->valuep());
+        }
+        if (dotps.empty()) return;
+        VL_RESTORER(m_modp);
+        m_modp = modp;
+        // Reverse-iterate so inner Dots resolve before outer.
+        for (auto it = dotps.rbegin(); it != dotps.rend(); ++it) resolveDotToTypedef(*it);
+    }
+
     AstNodeModule* nodeDeparam(AstNode* nodep, AstNodeModule* srcModp, AstNodeModule* modp,
                                const string& someInstanceName) {
         // Return new or reused de-parameterized module
@@ -2218,14 +2262,9 @@ public:
         }
         // Create new module name with _'s between the constants
         UINFOTREE(10, nodep, "", "cell");
-        // Resolve `class::member` Dots in pin values so constify sees Consts.
-        // Single-pass: filter-collect class-scoped Dots, then reverse-iterate so inner
-        // Dots resolve before outer (vector stays empty for cells with no class Dots).
-        std::vector<AstDot*> dotps;
-        nodep->foreach([&](AstDot* dotp) {
-            if (VN_IS(dotp->lhsp(), ClassOrPackageRef)) dotps.push_back(dotp);
-        });
-        for (auto it = dotps.rbegin(); it != dotps.rend(); ++it) resolveDotToTypedef(*it);
+        // Resolve `class::member` Dots in pin values, and in any deferred
+        // lparam reachable from the pin tree, so constify sees Consts.
+        resolveDeferredDotsReachableFrom(nodep, modp);
         // Evaluate all module constants
         V3Const::constifyParamsEdit(nodep);
         // Set name for warnings for when we param propagate the module
@@ -3173,6 +3212,9 @@ class ParamVisitor final : public VNVisitor {
     void visit(AstGenIf* nodep) override {
         UINFO(9, "  GENIF " << nodep);
         iterateAndNextNull(nodep->condp());
+        // condp may reference deferred lparams whose Dot is still pending;
+        // resolve them so widthing/constify can see Consts.
+        m_processor.resolveDeferredDotsReachableFrom(nodep->condp(), m_modp);
         // We suppress errors when widthing params since short-circuiting in
         // the conditional evaluation may mean these error can never occur. We
         // then make sure that short-circuiting is used by constifyParamsEdit.
@@ -3208,6 +3250,9 @@ class ParamVisitor final : public VNVisitor {
             iterateAndNextNull(forp->initsp());
             iterateAndNextNull(forp->condp());
             iterateAndNextNull(forp->incsp());
+            // Cond/init/inc may reference deferred lparams whose Dot is still
+            // pending; resolve them so widthing/constify can see Consts.
+            m_processor.resolveDeferredDotsReachableFrom(forp, m_modp);
             V3Width::widthParamsEdit(forp);  // Param typed widthing will NOT recurse the body
             // Outer wrapper around generate used to hold genvar, and to ensure genvar
             // doesn't conflict in V3LinkDot resolution with other genvars
@@ -3241,6 +3286,9 @@ class ParamVisitor final : public VNVisitor {
         AstNode* keepp = nullptr;
         iterateAndNextNull(nodep->exprp());
         V3Case::caseLint(nodep);
+        // expr / case items may reference deferred lparams whose Dot is still
+        // pending; resolve them so widthing/constify can see Consts.
+        m_processor.resolveDeferredDotsReachableFrom(nodep, m_modp);
         V3Width::widthParamsEdit(nodep);  // Param typed widthing will NOT recurse the
                                           // body, don't trigger errors yet.
         V3Const::constifyParamsEdit(nodep->exprp());  // exprp may change

test_regress/t/t_class_lparam_generate_chain.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 Edmund Lam
+# 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_class_lparam_generate_chain.v

@@ -0,0 +1,65 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Generate-for / generate-if / generate-case conditions that reference
+// a class-scope-resolved deferred localparam (e.g. inst::b). V3Param's
+// visit(AstGenIf/Block/Case) calls V3Width::widthParamsEdit /
+// constify on the cond/expr; the same transitive Dot-resolution used
+// for cell pins must be applied here so the deferred lparam folds.
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Edmund Lam
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`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
+
+// Cell whose presence is observable, used inside generate blocks
+// below to confirm each generate flavour elaborated the right way.
+module Tag #(
+    parameter int ID
+) ();
+  initial $write("Tag ID=%0d\n", ID);
+endmodule
+
+module t;
+  virtual class C #(
+      parameter int a
+  );
+    localparam int b = a;
+  endclass
+
+  typedef C#(3) c3;
+  typedef C#(5) c5;
+
+  // Deferred lparams
+  localparam int b3 = c3::b;
+  localparam int b5 = c5::b;
+
+  // (1) Generate-for bound = deferred lparam
+  for (genvar i = 0; i < b3; i++) begin : gf
+    Tag #(100 + i) inst ();
+  end
+
+  // (2) Generate-if cond = deferred lparam
+  if (b5 > b3) begin : gi_t
+    Tag #(200) inst ();
+  end else begin : gi_f
+    Tag #(201) inst ();
+  end
+
+  // (3) Generate-case selector = deferred lparam
+  case (b5)
+    3: begin : gc Tag #(303) inst (); end
+    5: begin : gc Tag #(305) inst (); end
+    default: begin : gc Tag #(399) inst (); end
+  endcase
+
+  initial begin
+    `checkh(b3, 32'd3);
+    `checkh(b5, 32'd5);
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_class_lparam_iface_chain.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 Edmund Lam
+# 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_class_lparam_iface_chain.v

@@ -0,0 +1,66 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Interface-instance parameter pins whose value chains through a
+// class-scope-resolved localparam (typedef alias of a parameterized
+// class, e.g. inst::b). Same cell-deparam fix that handles module
+// instances must also handle interface instances and downstream
+// port-bound consumers.
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Edmund Lam
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0)
+// verilog_format: on
+
+interface SubIface #(
+    parameter int IW
+) ();
+  logic [IW-1:0] data;
+endinterface
+
+// Module that takes an interface port — must elaborate after the iface
+// cell pin is fully constified.
+module Consumer (
+    SubIface si
+);
+endmodule
+
+module t;
+  virtual class C #(
+      parameter int a
+  );
+    localparam int b = a;
+  endclass
+
+  typedef C#(8) c8;
+  typedef C#(13) c13;
+
+  // Deferred lparams
+  localparam int b8 = c8::b;
+  localparam int b13 = c13::b;
+  // Chained
+  localparam int b8_alias = b8;
+
+  // Iface pin = bare VarRef to deferred lparam
+  SubIface #(b8) i_bare ();
+  // Iface pin = chained VarRef
+  SubIface #(b8_alias) i_chain ();
+  // Iface pin = expression mixing deferred lparams
+  SubIface #(b8 + b13) i_expr ();
+  // Iface used as a module port — exercises the iface-cell-first path
+  Consumer cons (.si(i_bare));
+
+  initial begin
+    `checkh(b8, 32'd8);
+    `checkh(b13, 32'd13);
+    `checkh(b8_alias, 32'd8);
+    `checkh($bits(i_bare.data), 32'd8);
+    `checkh($bits(i_chain.data), 32'd8);
+    `checkh($bits(i_expr.data), 32'd21);
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_class_lparam_module_chain.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 Edmund Lam
+# 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_class_lparam_module_chain.v

@@ -0,0 +1,71 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Module-instance parameter pins whose value chains through a
+// class-scope-resolved localparam (typedef alias of a parameterized
+// class, e.g. inst::b). V3LinkDot defers the inst::b Dot until
+// post-V3Param; the cell deparam must follow VarRefs into any
+// deferred lparam reachable from the pin tree and resolve its Dots
+// inline so constify on the cell can fold.
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Edmund Lam
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`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
+
+module Sub #(
+    parameter int WIDTH
+) ();
+endmodule
+
+// Two-level: outer module forwards its param to an inner cell, so the
+// deferred lparam value must flow through the cell-deparam chain.
+module SubL1 #(
+    parameter int W
+) ();
+  Sub #(W) inner ();
+endmodule
+
+module t;
+  virtual class C #(
+      parameter int a
+  );
+    localparam int b = a;
+  endclass
+
+  typedef C#(4) c4;
+  typedef C#(5) c5;
+  typedef C#(8) c8;
+
+  // Deferred lparams (value contains class::member Dot)
+  localparam int b4 = c4::b;
+  localparam int b5 = c5::b;
+  localparam int b8 = c8::b;
+  // Chained: value references another deferred lparam
+  localparam int c8_ref = b8;
+  localparam int d8_ref = c8_ref + 1;
+
+  // Pin is bare VarRef to a deferred lparam
+  Sub #(b8) m_bare ();
+  // Pin chains through multiple deferred lparams (b8 -> c8_ref -> d8_ref)
+  Sub #(d8_ref) m_chain ();
+  // Pin is an expression mixing two deferred lparams
+  Sub #(b4 + b5) m_expr ();
+  // Pin mixes a Dot and a deferred lparam in the same expression
+  Sub #(c4::b + b5) m_mix ();
+  // Two-level: outer module forwards param to inner cell
+  SubL1 #(b8) m_l1 ();
+
+  initial begin
+    `checkh(b4, 32'd4);
+    `checkh(b5, 32'd5);
+    `checkh(b8, 32'd8);
+    `checkh(c8_ref, 32'd8);
+    `checkh(d8_ref, 32'd9);
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_class_lparam_typedef_chain.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 Edmund Lam
+# 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_class_lparam_typedef_chain.v

@@ -0,0 +1,60 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// 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:
+//   - 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
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 Edmund Lam
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`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
+
+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 —
+    // resolveDotToTypedef must constify this when reached via CFG::width.
+    localparam int width = $bits(inner_t);
+  endclass
+
+  typedef C#(8) c8;
+
+  // Deferred lparam (direct Dot)
+  localparam int b8 = c8::b;
+
+  // (1) typedef range driven by a deferred lparam
+  typedef logic [b8-1:0] data_t;
+  data_t data_value;
+
+  // (2) class type-arg uses a deferred lparam value
+  typedef C#(b8) c_from_def;
+  localparam int from_def_b = c_from_def::b;
+
+  // (3) class-scope-resolved typedef computed via $bits(inner_t)
+  localparam int via_bits = c8::width;
+
+  // Wire whose range comes from a deferred lparam
+  logic [b8-1:0] wide_bus;
+
+  initial begin
+    `checkh(b8, 32'd8);
+    `checkh(from_def_b, 32'd8);
+    `checkh(via_bits, 32'd8);
+    data_value = '1;
+    `checkh(data_value, 8'hff);
+    wide_bus = '1;
+    `checkh(wide_bus, 8'hff);
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule