Fix associative array size() constraint generating invalid resize() call (#7103) (#7112)

src/V3Randomize.cpp

@@ -3915,16 +3915,21 @@ class RandomizeVisitor final : public VNVisitor {
 
                 queueVarp->user4p(sizeVarp);
 
-                AstTask* resizerTaskp = VN_AS(m_constraintp->user3p(), Task);
-                if (!resizerTaskp) {
-                    resizerTaskp = newResizeConstrainedArrayTask(classp, m_constraintp->name());
-                    m_constraintp->user3p(resizerTaskp);
+                // Associative arrays have no resize(); only generate resize
+                // for dynamic arrays and queues
+                if (!VN_IS(queueVarp->dtypep()->skipRefp(), AssocArrayDType)) {
+                    AstTask* resizerTaskp = VN_AS(m_constraintp->user3p(), Task);
+                    if (!resizerTaskp) {
+                        resizerTaskp
+                            = newResizeConstrainedArrayTask(classp, m_constraintp->name());
+                        m_constraintp->user3p(resizerTaskp);
+                    }
+                    AstCMethodHard* const resizep = new AstCMethodHard{
+                        fl, nodep->fromp()->unlinkFrBack(), VCMethod::DYN_RESIZE,
+                        new AstVarRef{fl, sizeVarp, VAccess::READ}};
+                    resizep->dtypep(nodep->findVoidDType());
+                    resizerTaskp->addStmtsp(new AstStmtExpr{fl, resizep});
                 }
-                AstCMethodHard* const resizep
-                    = new AstCMethodHard{fl, nodep->fromp()->unlinkFrBack(), VCMethod::DYN_RESIZE,
-                                         new AstVarRef{fl, sizeVarp, VAccess::READ}};
-                resizep->dtypep(nodep->findVoidDType());
-                resizerTaskp->addStmtsp(new AstStmtExpr{fl, resizep});
 
                 // Since size variable is signed int, we need additional constraint
                 // to make sure it is always >= 0.

test_regress/t/t_randomize_assoc_size.py

@@ -0,0 +1,21 @@
+#!/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')
+
+if not test.have_solver:
+    test.skip("No constraint solver installed")
+
+test.compile()
+
+test.execute()
+
+test.passes()

test_regress/t/t_randomize_assoc_size.v

@@ -0,0 +1,52 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain.
+// SPDX-FileCopyrightText: 2026 PlanV GmbH
+// SPDX-License-Identifier: CC0-1.0
+
+// verilog_format: off
+`define stop $stop
+`define checkd(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got=%0d exp=%0d\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0);
+// verilog_format: on
+
+module t;
+
+  // String-key associative array with size constraint
+  class StringKeyTest;
+    rand int data[string];
+    constraint c_size { data.size() == 3; }
+  endclass
+
+  // Int-key associative array with size constraint
+  class IntKeyTest;
+    rand bit [7:0] values[int];
+    constraint c_size { values.size() == 2; }
+  endclass
+
+  initial begin
+    automatic StringKeyTest str_obj = new();
+    automatic IntKeyTest int_obj = new();
+    automatic int rand_ok;
+
+    // String-key: pre-populate 3 entries to match constraint
+    str_obj.data["x"] = 0;
+    str_obj.data["y"] = 0;
+    str_obj.data["z"] = 0;
+
+    rand_ok = str_obj.randomize();
+    `checkd(rand_ok, 1);
+    `checkd(str_obj.data.size(), 3);
+
+    // Int-key: pre-populate 2 entries to match constraint
+    int_obj.values[10] = 0;
+    int_obj.values[20] = 0;
+
+    rand_ok = int_obj.randomize();
+    `checkd(rand_ok, 1);
+    `checkd(int_obj.values.size(), 2);
+
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+
+endmodule