Fix class members getting misoptimized away.

src/V3Ast.h

@@ -597,7 +597,8 @@ public:
         MODULETEMP,
         STMTTEMP,
         XTEMP,
-        IFACEREF        // Used to link Interfaces between modules
+        IFACEREF,  // Used to link Interfaces between modules
+        MEMBER
     };
     enum en m_e;
     inline AstVarType() : m_e(UNKNOWN) {}
@@ -612,7 +613,7 @@ public:
             "TRIWIRE", "TRI0", "TRI1",
             "PORT",
             "BLOCKTEMP", "MODULETEMP", "STMTTEMP", "XTEMP",
-            "IFACEREF"};
+            "IFACEREF", "MEMBER"};
         return names[m_e]; }
     bool isSignal() const {
         return (m_e==WIRE || m_e==WREAL || m_e==IMPLICITWIRE
@@ -632,7 +633,7 @@ public:
         return (m_e==GPARAM || m_e==LPARAM || m_e==GENVAR
                 || m_e==VAR
                 || m_e==BLOCKTEMP || m_e==MODULETEMP || m_e==STMTTEMP
-                || m_e==XTEMP || m_e==IFACEREF);
+                || m_e==XTEMP || m_e==IFACEREF || m_e==MEMBER);
     }
     bool isTemp() const {
         return (m_e==BLOCKTEMP || m_e==MODULETEMP || m_e==STMTTEMP || m_e==XTEMP);

src/V3AstNodes.cpp

@@ -1307,7 +1307,6 @@ void AstVar::dump(std::ostream& str) const {
     if (attrClockEn()) str<<" [aCLKEN]";
     if (attrIsolateAssign()) str<<" [aISO]";
     if (attrFileDescr()) str<<" [aFD]";
-    if (isClassMember()) str<<" [MEMBER]";
     if (isFuncReturn()) str<<" [FUNCRTN]";
     else if (isFuncLocal()) str<<" [FUNC]";
     if (isDpiOpenArray()) str<<" [DPIOPENA]";

src/V3AstNodes.h

@@ -1575,7 +1575,6 @@ private:
     bool        m_usedClock:1;  // Signal used as a clock
     bool        m_usedParam:1;  // Parameter is referenced (on link; later signals not setup)
     bool        m_usedLoopIdx:1;  // Variable subject of for unrolling
-    bool        m_classMember:1;  // Member variable for a class
     bool        m_funcLocal:1;  // Local variable for a function
     bool        m_funcReturn:1;  // Return variable for a function
     bool        m_attrClockEn:1;// User clock enable attribute
@@ -1603,7 +1602,6 @@ private:
         m_usedClock = false; m_usedParam = false; m_usedLoopIdx = false;
         m_sigPublic = false; m_sigModPublic = false;
         m_sigUserRdPublic = false; m_sigUserRWPublic = false;
-        m_classMember = false;
         m_funcLocal = false; m_funcReturn = false;
         m_attrClockEn = false; m_attrScBv = false;
         m_attrIsolateAssign = false; m_attrSFormat = false; m_attrSplitVar = false;
@@ -1724,7 +1722,6 @@ public:
     void isConst(bool flag) { m_isConst = flag; }
     void isStatic(bool flag) { m_isStatic = flag; }
     void isIfaceParent(bool flag) { m_isIfaceParent = flag; }
-    void classMember(bool flag) { m_classMember = flag; }
     void funcLocal(bool flag) { m_funcLocal = flag; }
     void funcReturn(bool flag) { m_funcReturn = flag; }
     void isDpiOpenArray(bool flag) { m_isDpiOpenArray = flag; }
@@ -1756,6 +1753,7 @@ public:
                 && (isIO() || isBitLogic())
                 // Wrapper would otherwise duplicate wrapped module's coverage
                 && !isSc() && !isPrimaryIO() && !isConst()); }
+    bool isClassMember() const { return varType() == AstVarType::MEMBER; }
     bool isStatementTemp() const { return (varType()==AstVarType::STMTTEMP); }
     bool isMovableToBlock() const { return (varType()==AstVarType::BLOCKTEMP || isFuncLocal()); }
     bool isXTemp() const { return (varType()==AstVarType::XTEMP); }
@@ -1779,7 +1777,6 @@ public:
     bool isTrace() const { return m_trace; }
     bool isConst() const { return m_isConst; }
     bool isStatic() const { return m_isStatic; }
-    bool isClassMember() const { return m_classMember; }
     bool isFuncLocal() const { return m_funcLocal; }
     bool isFuncReturn() const { return m_funcReturn; }
     bool isPullup() const { return m_isPullup; }

src/V3Dead.cpp

@@ -328,6 +328,7 @@ private:
     bool mightElimVar(AstVar* nodep) {
         return (!nodep->isSigPublic()  // Can't elim publics!
                 && !nodep->isIO()
+                && !nodep->isClassMember()
                 && ((nodep->isTemp() && !nodep->isTrace())
                     || (nodep->isParam() && !nodep->isTrace() && !v3Global.opt.xmlOnly())
                     || m_elimUserVars));  // Post-Trace can kill most anything

src/V3EmitC.cpp

@@ -2513,7 +2513,8 @@ void EmitCStmts::emitVarList(AstNode* firstp, EisWhich which, const string& pref
                 bool doit = true;
                 switch (which) {
                 case EVL_CLASS_IO:   doit = varp->isIO(); break;
-                case EVL_CLASS_SIG:  doit = (varp->isSignal() && !varp->isIO()); break;
+                case EVL_CLASS_SIG:
+                    doit = ((varp->isSignal() || varp->isClassMember()) && !varp->isIO()); break;
                 case EVL_CLASS_TEMP: doit = (varp->isTemp() && !varp->isIO()); break;
                 case EVL_CLASS_PAR:  doit = (varp->isParam() && !VN_IS(varp->valuep(), Const)); break;
                 case EVL_CLASS_ALL:  doit = true; break;

src/V3LinkResolve.cpp

@@ -100,7 +100,7 @@ private:
     }
     virtual void visit(AstVar* nodep) VL_OVERRIDE {
         iterateChildren(nodep);
-        if (m_classp) nodep->classMember(true);
+        if (m_classp) nodep->varType(AstVarType::MEMBER);
         if (m_ftaskp) nodep->funcLocal(true);
         if (nodep->isSigModPublic()) {
             nodep->sigModPublic(false);  // We're done with this attribute

src/V3Localize.cpp

@@ -129,6 +129,7 @@ private:
             if ((nodep->isMovableToBlock()  // Blocktemp
                  || !flags.m_notStd)  // Or used only in block
                 && !flags.m_notOpt  // Optimizable
+                && !nodep->isClassMember()
                 && nodep->user1p()) {  // Single cfunc
                 // We don't need to test for tracing; it would be in the tracefunc if it was needed
                 UINFO(4,"  ModVar->BlkVar "<<nodep<<endl);