Fix localparam elaboration (#3858) (#4794)

src/V3Param.cpp

@@ -825,7 +825,7 @@ class ParamProcessor final {
         }
     }
 
-    void storeOriginalParams(AstClass* const classp) {
+    void storeOriginalParams(AstNodeModule* const classp) {
         for (AstNode* stmtp = classp->stmtsp(); stmtp; stmtp = stmtp->nextp()) {
             AstNode* originalParamp = nullptr;
             if (AstVar* const varp = VN_CAST(stmtp, Var)) {
@@ -870,13 +870,13 @@ class ParamProcessor final {
             UINFO(8, "Cell parameters all match original values, skipping expansion.\n");
             // If it's the first use of the default instance, create a copy and store it in user3p.
             // user3p will also be used to check if the default instance is used.
-            if (!srcModpr->user3p() && VN_IS(srcModpr, Class)) {
-                AstClass* classCopyp = VN_AS(srcModpr, Class)->cloneTree(false);
+            if (!srcModpr->user3p() && (VN_IS(srcModpr, Class) || VN_IS(srcModpr, Iface))) {
+                AstNodeModule* nodeCopyp = srcModpr->cloneTree(false);
                 // It is a temporary copy of the original class node, stored in order to create
                 // another instances. It is needed only during class instantiation.
-                m_deleter.pushDeletep(classCopyp);
-                srcModpr->user3p(classCopyp);
-                storeOriginalParams(classCopyp);
+                m_deleter.pushDeletep(nodeCopyp);
+                srcModpr->user3p(nodeCopyp);
+                storeOriginalParams(nodeCopyp);
             }
         } else {
             const string newname

test_regress/t/t_interface_localparam.out

@@ -1,5 +1,3 @@
 *-* All Finished *-*
 top.t.intf: symbolsPerBeat 16, symbolsPerBeatDivBy2 8, mismatch 0
-top.t.theCore.core_intf: symbolsPerBeat 64, symbolsPerBeatDivBy2 8, mismatch 1
-%Error: t/t_interface_localparam_unsup.v:23: Verilog $stop
-Aborting...
+top.t.theCore.core_intf: symbolsPerBeat 64, symbolsPerBeatDivBy2 32, mismatch 0

test_regress/t/t_interface_localparam.pl

@@ -15,8 +15,6 @@ compile(
 
 execute(
     check_finished => 1,
-    fails => $Self->{vlt_all},
-    expect_filename => $Self->{golden_filename},
 );
 
 ok(1);

test_regress/t/t_interface_localparam.v

@@ -0,0 +1,60 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2023 by Justin Thiel.
+// SPDX-License-Identifier: CC0-1.0
+
+interface SimpleIntf
+#(
+   parameter int val = 28
+)
+();
+
+   // This value is calculated incorrectly for other instances of
+   // this interface when it is accessed via the HDL for any other
+   // instance of this interface
+   localparam int valDiv2  = val/2;
+   localparam int valDiv4  = valDiv2/2;
+
+   localparam bit mismatch2 = (val != (2*valDiv2) );
+   localparam bit mismatch4 = (val != (4*valDiv4) );
+
+   initial begin
+      $write("%m: val %0d, valDiv2 %0d, mismatch2 %0d\n",
+             val, valDiv2, mismatch2);
+      $write("%m: val %0d, valDiv4 %0d, mismatch4 %0d\n",
+             val, valDiv4, mismatch2);
+      if (mismatch2) $stop;
+      if (mismatch4) $stop;
+   end
+
+endinterface
+
+module Core(
+   SimpleIntf intf
+);
+
+   // this will constify and valDiv2 will have the default value
+   localparam valDiv4Upper = intf.valDiv2;
+
+   SimpleIntf #(.val(68)) core_intf ();
+
+   initial begin
+      if (intf.valDiv2 != valDiv4Upper) begin
+         $display("%%Error: param = %0d", intf.valDiv2);
+      end
+   end
+endmodule
+
+module t();
+
+   SimpleIntf intf();
+
+   Core theCore (.intf);
+
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule

test_regress/t/t_interface_localparam_unsup.v

@@ -1,51 +0,0 @@
-// DESCRIPTION: Verilator: Verilog Test module
-//
-// This file ONLY is placed into the Public Domain, for any use,
-// without warranty, 2023 by Justin Thiel.
-// SPDX-License-Identifier: CC0-1.0
-
-interface SimpleIntf
-#(
-   parameter int symbolsPerBeat = 16
-)
-();
-
-   // This value is calculated incorrectly for other instances of
-   // this interface when it is accessed via the HDL for any other
-   // instance of this interface
-   localparam int symbolsPerBeatDivBy2  = symbolsPerBeat/2;
-
-   localparam bit mismatch = (symbolsPerBeat != (2*symbolsPerBeatDivBy2) );
-
-   initial begin
-      $write("%m: symbolsPerBeat %0d, symbolsPerBeatDivBy2 %0d, mismatch %0d\n",
-             symbolsPerBeat, symbolsPerBeatDivBy2, mismatch);
-      if (mismatch) $stop;
-   end
-
-endinterface
-
-module Core(
-   SimpleIntf intf
-);
-
-   // NOTE: When this line is commented out the test will pass
-   localparam intf_symbolsPerBeatDivBy2 = intf.symbolsPerBeatDivBy2;
-
-   localparam int core_intf_symbolsPerBeat = 64;
-   SimpleIntf #(.symbolsPerBeat(core_intf_symbolsPerBeat)) core_intf ();
-
-endmodule
-
-module t();
-
-   SimpleIntf intf();
-
-   Core theCore (.intf);
-
-   initial begin
-      $write("*-* All Finished *-*\n");
-      $finish;
-   end
-
-endmodule