Support pre_randomize and post_randomize.

Changes

@@ -16,6 +16,7 @@ Verilator 5.003 devel
 * Deprecate --no-threads; use --threads 1 for single threaded (#3703). [Kamil Rakoczy, Antmicro Ltd]
 * Support named properties (#3667). [Ryszard Rozak, Antmicro Ltd]
 * Support randcase.
+* Support pre_randomize and post_randomize.
 * Add ENUMVALUE warning when value misused for enum (#726).
 * Internal AST improvements, also affect XML format (#3721). [Geza Lore]
 * Change ENDLABEL from warning into an error.

src/V3AstNodeExpr.h

@@ -1585,7 +1585,7 @@ class AstThisRef final : public AstNodeExpr {
     // Reference to 'this'.
     // @astgen op1 := childDTypep : Optional[AstClassRefDType] // dtype of the node
 public:
-    explicit AstThisRef(FileLine* fl, AstClassRefDType* dtypep)
+    AstThisRef(FileLine* fl, VFlagChildDType, AstClassRefDType* dtypep)
         : ASTGEN_SUPER_ThisRef(fl) {
         childDTypep(dtypep);
     }

src/V3LinkDot.cpp

@@ -2342,7 +2342,7 @@ private:
             AstClass* const classp = VN_AS(classSymp->nodep(), Class);
             AstClassRefDType* const dtypep
                 = new AstClassRefDType{nodep->fileline(), classp, nullptr};
-            AstThisRef* const newp = new AstThisRef{nodep->fileline(), dtypep};
+            AstThisRef* const newp = new AstThisRef{nodep->fileline(), VFlagChildDType{}, dtypep};
             nodep->replaceWith(newp);
             VL_DO_DANGLING(pushDeletep(nodep), nodep);
             return;

src/V3LinkResolve.cpp

@@ -115,9 +115,7 @@ private:
         if (m_underGenerate) nodep->underGenerate(true);
         // Remember the existing symbol table scope
         if (m_classp) {
-            if (nodep->name() == "pre_randomize" || nodep->name() == "post_randomize") {
-                nodep->v3warn(E_UNSUPPORTED, "Unsupported: " << nodep->prettyNameQ());
-            } else if (nodep->name() == "randomize") {
+            if (nodep->name() == "randomize") {
                 nodep->v3error(nodep->prettyNameQ()
                                << " is a predefined class method; redefinition not allowed"
                                   " (IEEE 1800-2017 18.6.3)");

src/V3Randomize.cpp

@@ -198,6 +198,14 @@ private:
                                  valp};
         }
     }
+    void addPrePostCall(AstClass* classp, AstFunc* funcp, const string& name) {
+        if (AstTask* userFuncp = VN_CAST(classp->findMember(name), Task)) {
+            AstTaskRef* const callp
+                = new AstTaskRef{userFuncp->fileline(), userFuncp->name(), nullptr};
+            callp->taskp(userFuncp);
+            funcp->addStmtsp(callp->makeStmt());
+        }
+    }
 
     // VISITORS
     void visit(AstNodeModule* nodep) override {
@@ -215,6 +223,7 @@ private:
         UINFO(9, "Define randomize() for " << nodep << endl);
         AstFunc* const funcp = V3Randomize::newRandomizeFunc(nodep);
         AstVar* const fvarp = VN_AS(funcp->fvarp(), Var);
+        addPrePostCall(nodep, funcp, "pre_randomize");
         funcp->addStmtsp(new AstAssign{
             nodep->fileline(), new AstVarRef{nodep->fileline(), fvarp, VAccess::WRITE},
             new AstConst{nodep->fileline(), AstConst::WidthedValue{}, 32, 1}});
@@ -250,6 +259,7 @@ private:
                 }
             }
         }
+        addPrePostCall(nodep, funcp, "post_randomize");
         nodep->user1(false);
     }
     void visit(AstRandCase* nodep) override {

test_regress/t/t_randomize_method_unsup.out

@@ -1,8 +0,0 @@
-%Error-UNSUPPORTED: t/t_randomize_method_unsup.v:8:18: Unsupported: 'pre_randomize'
-    8 |    function void pre_randomize;
-      |                  ^~~~~~~~~~~~~
-                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
-%Error-UNSUPPORTED: t/t_randomize_method_unsup.v:11:18: Unsupported: 'post_randomize'
-   11 |    function void post_randomize;
-      |                  ^~~~~~~~~~~~~~
-%Error: Exiting due to

test_regress/t/t_randomize_method_unsup.v

@@ -1,16 +0,0 @@
-// DESCRIPTION: Verilator: Verilog Test module
-//
-// This file ONLY is placed under the Creative Commons Public Domain, for
-// any use, without warranty, 2020 by Wilson Snyder.
-// SPDX-License-Identifier: CC0-1.0
-
-class Cls;
-   function void pre_randomize;
-   endfunction;
-
-   function void post_randomize;
-   endfunction;
-endclass
-
-module t (/*AUTOARG*/);
-endmodule

test_regress/t/t_randomize_prepost.pl

@@ -11,8 +11,10 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 scenarios(simulator => 1);
 
 compile(
-    fails => $Self->{vlt_all},
-    expect_filename => $Self->{golden_filename},
+    );
+
+execute(
+    check_finished => 1,
     );
 
 ok(1);

test_regress/t/t_randomize_prepost.v

@@ -0,0 +1,47 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2022 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+typedef enum int {
+   RANDOMIZED = 20
+} enumed_t;
+
+class Cls;
+   int       pre;
+   rand enumed_t r;
+   int       post;
+
+   function void pre_randomize;
+      if (pre != 0) $stop;
+      $display("%d", r);
+      if (r != enumed_t'(0)) $stop;
+      if (post != 0) $stop;
+      pre = 10;
+   endfunction
+
+   function void post_randomize;
+      if (pre != 10) $stop;
+      if (r != RANDOMIZED) $stop;
+      if (post != 0) $stop;
+      post = 30;
+   endfunction
+endclass
+
+module t (/*AUTOARG*/);
+
+   initial begin
+      Cls c;
+      int rand_result;
+
+      c = new;
+      rand_result = c.randomize();
+      if (rand_result != 1) $stop;
+      if (c.pre != 10) $stop;
+      if (c.r != RANDOMIZED) $stop;
+      if (c.post != 30) $stop;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule