Track rand/randc qualifier on unpacked struct members

The random_qualifier on struct/union members was discarded at parse time.
Record it as a VRandAttr on AstMemberDType (mirroring AstVar), threaded
through GRAMMARP->m_memRand and applied when each member node is built,
with dump()/dumpJson() support. No behavioral change on its own; consumed
by the following commit.

src/V3AstNodeDType.h

@@ -968,7 +968,7 @@ class AstMemberDType final : public AstNodeDType {
     string m_tag;  // Holds the string of the verilator tag -- used in JSON output.
     int m_lsb = -1;  // Within this level's packed struct, the LSB of the first bit of the member
     bool m_constrainedRand = false;
-    // UNSUP: int m_randType;    // Randomization type (IEEE)
+    VRandAttr m_rand;  // Randomizability of this member (rand, randc, etc)
 public:
     AstMemberDType(FileLine* fl, const string& name, VFlagChildDType, AstNodeDType* dtp,
                    AstNode* valuep)
@@ -1025,6 +1025,8 @@ public:
     }
     bool isConstrainedRand() const { return m_constrainedRand; }
     void markConstrainedRand(bool flag) { m_constrainedRand = flag; }
+    VRandAttr rand() const { return m_rand; }
+    void rand(const VRandAttr flag) { m_rand = flag; }
 };
 class AstNBACommitQueueDType final : public AstNodeDType {
     // @astgen ptr := m_subDTypep : AstNodeDType  // Type of the corresponding variable

src/V3AstNodes.cpp

@@ -2488,12 +2488,14 @@ const char* AstLoopTest::broken() const {
 void AstMemberDType::dump(std::ostream& str) const {
     this->AstNodeDType::dump(str);
     if (isConstrainedRand()) str << " [CONSTRAINEDRAND]";
+    if (rand().isRandomizable()) str << " [" << rand() << "]";
     if (name() != "") str << " name=" << name();
     if (tag() != "") str << " tag=" << tag();
 }
 
 void AstMemberDType::dumpJson(std::ostream& str) const {
     dumpJsonBoolFuncIf(str, isConstrainedRand);
+    if (rand().isRandomizable()) dumpJsonStr(str, "rand", rand().ascii());
     dumpJsonStrFunc(str, name);
     dumpJsonStrFunc(str, tag);
     dumpJsonGen(str);

src/V3ParseGrammar.h

@@ -31,6 +31,7 @@ public:
     AstCase* m_caseAttrp = nullptr;  // Current case statement for attribute adding
     AstNodeDType* m_varDTypep = nullptr;  // Pointer to data type for next signal declaration
     AstNodeDType* m_memDTypep = nullptr;  // Pointer to data type for next member declaration
+    VRandAttr m_memRand;  // 'rand'/'randc' qualifier for next member declaration
     AstDelay* m_netDelayp = nullptr;  // Pointer to delay for next signal declaration
     AstStrengthSpec* m_netStrengthp = nullptr;  // Pointer to strength for next net declaration
     FileLine* m_instModuleFl = nullptr;  // Fileline of module referenced for instantiations

src/V3ParseImp.h

@@ -69,6 +69,11 @@ struct VMemberQualifiers final {
         q.m_flags = a.m_flags | b.m_flags;
         return q;
     }
+    VRandAttr randAttr() const {
+        if (m_randc) return VRandAttr::RAND_CYCLIC;
+        if (m_rand) return VRandAttr::RAND;
+        return VRandAttr::NONE;
+    }
     void applyToNodes(AstNodeFTask* nodesp) const {
         for (AstNodeFTask* nodep = nodesp; nodep; nodep = VN_AS(nodep->nextp(), NodeFTask)) {
             if (m_local) nodep->isHideLocal(true);

src/verilog.y

@@ -2204,11 +2204,13 @@ struct_union_memberList<memberDTypep>: // IEEE: { struct_union_member }
         ;
 
 struct_union_member<memberDTypep>:     // ==IEEE: struct_union_member
-        //                      // UNSUP random_qualifer not propagated until have randomize support
                 random_qualifierE data_type_or_void
-        /*mid*/         { GRAMMARP->m_memDTypep = $2; }  // As a list follows, need to attach this dtype to each member.
+        /*mid*/         { GRAMMARP->m_memDTypep = $2;  // As a list follows, need to attach this dtype to each member.
+                          GRAMMARP->m_memRand = $1.randAttr(); }
         /*cont*/    list_of_member_decl_assignments ';'
-                        { $$ = $4; DEL(GRAMMARP->m_memDTypep); GRAMMARP->m_memDTypep = nullptr; }
+                        { $$ = $4;
+                          DEL(GRAMMARP->m_memDTypep); GRAMMARP->m_memDTypep = nullptr;
+                          GRAMMARP->m_memRand = VRandAttr::NONE; }
         |       vlTag                                   { $$ = nullptr; }
         ;
 
@@ -2226,6 +2228,7 @@ member_decl_assignment<memberDTypep>:   // Derived from IEEE: variable_decl_assi
                                                                          ? GRAMMARP->m_memDTypep->cloneTree(true) : nullptr),
                                                                         $2, false),
                                                   nullptr};
+                          $$->rand(GRAMMARP->m_memRand);
                           PARSEP->tagNodep($$);
                         }
         |       idAny variable_dimensionListE '=' variable_declExpr
@@ -2234,6 +2237,7 @@ member_decl_assignment<memberDTypep>:   // Derived from IEEE: variable_decl_assi
                                                                          ? GRAMMARP->m_memDTypep->cloneTree(true) : nullptr),
                                                                         $2, false),
                                                   $4};
+                          $$->rand(GRAMMARP->m_memRand);
                           PARSEP->tagNodep($$);
                         }
         |       idSVKwd                                 { $$ = nullptr; }

test_regress/t/t_debug_emitv.out

@@ -10,6 +10,7 @@ module Vt_debug_emitv_t;
     } ps_t;
     typedef struct {
         logic signed [2:0]  a;
+        logic [1:0]  b;
     } us_t;
     typedef union {
         logic a;
@@ -19,6 +20,7 @@ module Vt_debug_emitv_t;
     } ps[0:2];
     struct {
         logic signed [2:0]  a;
+        logic [1:0]  b;
     } us;
     union {
         logic a;

test_regress/t/t_debug_emitv.v

@@ -64,6 +64,7 @@ module t (/*AUTOARG*/
   } ps_t;
   typedef struct {
     logic signed [2:0] a;
+    rand logic [1:0] b;
   } us_t;
   typedef union {
     logic a;