Add parsing but otherwise ignore std::randomize (#5354)

include/verilated_std.sv

@@ -195,4 +195,7 @@ package std;
          $urandom(s.atoi());  // Set the seed using a string
       endfunction
    endclass
+   function int randomize();
+      randomize = 0;
+   endfunction
 endpackage

src/V3LinkDot.cpp

@@ -1508,11 +1508,15 @@ class LinkDotFindVisitor final : public VNVisitor {
 
     void visit(AstWithParse* nodep) override {
         // Change WITHPARSE(FUNCREF, equation) to FUNCREF(WITH(equation))
-        const auto funcrefp = VN_AS(nodep->funcrefp(), NodeFTaskRef);
+        AstNodeFTaskRef* funcrefp = VN_CAST(nodep->funcrefp(), NodeFTaskRef);
+        if (const AstDot* const dotp = VN_CAST(nodep->funcrefp(), Dot))
+            funcrefp = VN_CAST(dotp->rhsp(), NodeFTaskRef);
         UASSERT_OBJ(funcrefp, nodep, "'with' only can operate on a function/task");
         string name = "item";
         FileLine* argFl = nodep->fileline();
-        if (const auto argp = VN_CAST(funcrefp->pinsp(), Arg)) {
+        AstArg* argp = VN_CAST(funcrefp->pinsp(), Arg);
+        if (argp) argp->unlinkFrBackWithNext();
+        if (argp && funcrefp->name() != "randomize") {
             if (const auto parserefp = VN_CAST(argp->exprp(), ParseRef)) {
                 name = parserefp->name();
                 argFl = parserefp->fileline();
@@ -1521,7 +1525,7 @@ class LinkDotFindVisitor final : public VNVisitor {
             }
             if (argp->nextp())
                 argp->nextp()->v3error("'with' function expects only up to one argument");
-            VL_DO_DANGLING(argp->unlinkFrBackWithNext()->deleteTree(), argp);
+            VL_DO_DANGLING(argp->deleteTree(), argp);
         }
         // Type depends on the method used, let V3Width figure it out later
         if (nodep->exprsp()) {  // Else empty expression and pretend no "with"
@@ -1531,7 +1535,8 @@ class LinkDotFindVisitor final : public VNVisitor {
                                           nodep->exprsp()->unlinkFrBackWithNext()};
             funcrefp->addPinsp(newp);
         }
-        nodep->replaceWith(funcrefp->unlinkFrBack());
+        funcrefp->addPinsp(argp);
+        nodep->replaceWith(nodep->funcrefp()->unlinkFrBack());
         VL_DO_DANGLING(nodep->deleteTree(), nodep);
     }
     void visit(AstWith* nodep) override {

src/V3Width.cpp

@@ -5917,6 +5917,18 @@ class WidthVisitor final : public VNVisitor {
                            || nodep->name() == "set_randstate"))) {
             // TODO perhaps this should move to V3LinkDot
             AstClass* const classp = VN_CAST(nodep->classOrPackagep(), Class);
+            if (!classp) {
+                AstNodeDType* const adtypep = nodep->findBitDType();
+                withp = methodWithArgument(nodep, false, false, adtypep->findVoidDType(),
+                                           adtypep->findBitDType(), adtypep);
+                for (const AstNode* argp = nodep->pinsp(); argp; argp = argp->nextp())
+                    userIterateAndNext(VN_AS(argp, Arg)->exprp(), WidthVP{SELF, BOTH}.p());
+                nodep->addPinsp(withp);
+                nodep->v3warn(CONSTRAINTIGN, "std::randomize ignored (unsupported)");
+                nodep->replaceWith(new AstConst{nodep->fileline(), 0});
+                VL_DO_DANGLING(pushDeletep(nodep), nodep);
+                return;
+            }
             UASSERT_OBJ(classp, nodep, "Should have failed in V3LinkDot");
             if (nodep->name() == "randomize") {
                 nodep->taskp(V3Randomize::newRandomizeFunc(m_memberMap, classp));

test_regress/t/t_std_randomize_unsup_bad.out

@@ -0,0 +1,11 @@
+%Warning-CONSTRAINTIGN: t/t_std_randomize_unsup_bad.v:10:16: std::randomize ignored (unsupported)
+                                                           : ... note: In instance 't'
+   10 |       if (std::randomize(a, b) != 1) $stop;
+      |                ^~~~~~~~~
+                        ... For warning description see https://verilator.org/warn/CONSTRAINTIGN?v=latest
+                        ... Use "/* verilator lint_off CONSTRAINTIGN */" and lint_on around source to disable this message.
+%Warning-CONSTRAINTIGN: t/t_std_randomize_unsup_bad.v:11:16: std::randomize ignored (unsupported)
+                                                           : ... note: In instance 't'
+   11 |       if (std::randomize(a, b) with { 2 < a; a < 7; b < a; } != 1) $stop;
+      |                ^~~~~~~~~
+%Error: Exiting due to

test_regress/t/t_std_randomize_unsup_bad.pl

@@ -0,0 +1,19 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 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
+
+scenarios(linter => 1);
+
+lint(
+    fails => 1,
+    expect_filename => $Self->{golden_filename},
+    );
+
+ok(1);
+1;

test_regress/t/t_std_randomize_unsup_bad.v

@@ -0,0 +1,16 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2024 by Antmicro Ltd.
+// SPDX-License-Identifier: CC0-1.0
+
+module t;
+   initial begin
+      int a, b;
+      if (std::randomize(a, b) != 1) $stop;
+      if (std::randomize(a, b) with { 2 < a; a < 7; b < a; } != 1) $stop;
+      if (!(2 < a && a < 7 && b < a)) $stop;
+      $write("-*-* All Finished *-*-\n");
+      $finish;
+   end
+endmodule