verilator/src/V3LinkDot.cpp

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Resolve module/signal name references
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2003-2018 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.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
//*************************************************************************
// LinkDot TRANSFORMATIONS:
//	Top-down traversal in LinkDotFindVisitor
//	    Cells:
//		Make graph of cell hierarchy
//	    Var/Funcs's:
//		Collect all names into symtable under appropriate cell
//	Top-down traversal in LinkDotScopeVisitor
//	    Find VarScope versions of signals (well past original link)
//	Top-down traversal in LinkDotParamVisitor
//	    Create implicit signals
//	Top-down traversal in LinkDotResolveVisitor
//	    VarXRef/Func's:
//		Find appropriate named cell and link to var they reference
//*************************************************************************
// Interfaces:
//	CELL (.port (ifref)
//		       ^--- cell                 -> IfaceDTypeRef(iface)
//	  	       ^--- cell.modport	 -> IfaceDTypeRef(iface,modport)
//		       ^--- varref(input_ifref)  -> IfaceDTypeRef(iface)
//		       ^--- varref(input_ifref).modport -> IfaceDTypeRef(iface,modport)
//	FindVisitor:
//	    #1: Insert interface Vars
//	    #2: Insert ModPort names
//	  IfaceVisitor:
//	    #3: Update ModPortVarRef to point at interface vars (after #1)
//	    #4: Create ModPortVarRef symbol table entries
//	  FindVisitor-insertIfaceRefs()
//	    #5: Resolve IfaceRefDtype modport names (after #2)
//	    #7: Record sym of IfaceRefDType and aliased interface and/or modport (after #4,#5)
//	insertAllScopeAliases():
//	    #8: Insert modport's symbols under IfaceRefDType (after #7)
//	ResolveVisitor:
//	    #9: Resolve general variables, which may point into the interface or modport (after #8)
//*************************************************************************
// TOP
//      {name-of-top-modulename}
//      a          (VSymEnt->AstCell)
//	  {name-of-cell}
//	  {name-of-cell-module}
//        aa         (VSymEnt->AstCell)
//          var        (AstVar) -- no sub symbol table needed
//          beg        (VSymEnt->AstBegin) -- can see "upper" a's symbol table
//      a__DOT__aa (VSymEnt->AstCellInline) -- points to a.aa's symbol table
//      b          (VSymEnt->AstCell)
//*************************************************************************

#include "config_build.h"
#include "verilatedos.h"

#include "V3Global.h"
#include "V3LinkDot.h"
#include "V3SymTable.h"
#include "V3Graph.h"
#include "V3Ast.h"
#include "V3ParseImp.h"
#include "V3String.h"

#include <algorithm>
#include <cstdarg>
#include <map>
#include <vector>

//######################################################################
// LinkDot state, as a visitor of each AstNode

class LinkDotState {
private:
    // NODE STATE
    // Cleared on Netlist
    //  AstNodeModule::user1p()		// VSymEnt*.      Last symbol created for this node
    //  AstNodeModule::user2()		// bool.          Currently processing for recursion check
    //	...				      Note maybe more than one, as can be multiple hierarchy places
    //  AstVarScope::user2p()		// AstVarScope*.  Base alias for AstInline of this signal
    //  AstVar::user2p()		// AstFTask*.     If a function variable, the task that links to the variable
    //  AstVar::user4()			// bool.          True if port set for this variable
    //  AstBegin::user4()		// bool.	  Did name processing
    //  AstNodeModule::user4()		// bool.          Live module
    AstUser1InUse	m_inuser1;
    AstUser2InUse	m_inuser2;
    AstUser4InUse	m_inuser4;

public:
    // ENUMS
    // In order of priority, compute first ... compute last
    enum SAMNum { SAMN_MODPORT, SAMN_IFTOP, SAMN__MAX };	// Values for m_scopeAliasMap

private:
    // TYPES
    typedef std::multimap<string,VSymEnt*> NameScopeSymMap;
    typedef std::map<VSymEnt*,VSymEnt*> ScopeAliasMap;
    typedef std::set<std::pair<AstNodeModule*,string> > ImplicitNameSet;
    typedef std::vector<VSymEnt*> IfaceVarSyms;
    typedef std::vector<std::pair<AstIface*,VSymEnt*> > IfaceModSyms;

    static LinkDotState* s_errorThisp;		// Last self, for error reporting only

    // MEMBERS
    VSymGraph		m_syms;			// Symbol table
    VSymEnt*		m_dunitEntp;		// $unit entry
    NameScopeSymMap	m_nameScopeSymMap;	// Map of scope referenced by non-pretty textual name
    ImplicitNameSet	m_implicitNameSet;	// For [module][signalname] if we can implicitly create it
    ScopeAliasMap	m_scopeAliasMap[SAMN__MAX]; // Map of <lhs,rhs> aliases
    IfaceVarSyms	m_ifaceVarSyms;		// List of AstIfaceRefDType's to be imported
    IfaceModSyms	m_ifaceModSyms;		// List of AstIface+Symbols to be processed
    bool		m_forPrimary;		// First link
    bool		m_forPrearray;		// Compress cell__[array] refs
    bool		m_forScopeCreation;	// Remove VarXRefs for V3Scope

public:

    // METHODS
    VL_DEBUG_FUNC;  // Declare debug()
    void dump(const string& nameComment="linkdot", bool force=false) {
	if (debug()>=6 || force) {
	    string filename = v3Global.debugFilename(nameComment)+".txt";
            const vl_unique_ptr<std::ofstream> logp (V3File::new_ofstream(filename));
            if (logp->fail()) v3fatal("Can't write "<<filename);
            std::ostream& os = *logp;
	    m_syms.dump(os);
	    bool first = true;
	    for (int samn=0; samn<SAMN__MAX; ++samn) {
		if (!m_scopeAliasMap[samn].empty()) {
		    if (first) os<<"\nScopeAliasMap:\n";
		    first = false;
		    for (ScopeAliasMap::iterator it = m_scopeAliasMap[samn].begin();
			 it != m_scopeAliasMap[samn].end(); ++it) {
			// left side is what we will import into
			os<<"\t"<<samn<<"\t"<<it->first<<" ("<<it->first->nodep()->typeName()
			  <<") <- "<<it->second<<" "<<it->second->nodep()<<endl;
		    }
		}
	    }
	}
    }
    static void preErrorDumpHandler() {
	if (s_errorThisp) s_errorThisp->preErrorDump();
    }
    void preErrorDump() {
	static bool diddump = false;
	if (!diddump && v3Global.opt.dumpTree()) {
	    diddump = true;
	    dump("linkdot-preerr",true);
	    v3Global.rootp()->dumpTreeFile(v3Global.debugFilename("linkdot-preerr.tree"));
	}
    }

    // CONSTRUCTORS
    LinkDotState(AstNetlist* rootp, VLinkDotStep step)
	: m_syms(rootp) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_forPrimary = (step==LDS_PRIMARY);
	m_forPrearray = (step == LDS_PARAMED || step==LDS_PRIMARY);
	m_forScopeCreation = (step == LDS_SCOPED);
	m_dunitEntp = NULL;
	s_errorThisp = this;
	V3Error::errorExitCb(preErrorDumpHandler);  // If get error, dump self
    }
    ~LinkDotState() {
	V3Error::errorExitCb(NULL);
	s_errorThisp = NULL;
    }

    // ACCESSORS
    VSymGraph* symsp() { return &m_syms; }
    bool forPrimary() const { return m_forPrimary; }
    bool forPrearray() const { return m_forPrearray; }
    bool forScopeCreation() const { return m_forScopeCreation; }

    // METHODS
    static string nodeTextType(AstNode* nodep) {
        if (VN_IS(nodep, Var)) return "variable";
        else if (VN_IS(nodep, Cell)) return "cell";
        else if (VN_IS(nodep, Task)) return "task";
        else if (VN_IS(nodep, Func)) return "function";
        else if (VN_IS(nodep, Begin)) return "block";
        else if (VN_IS(nodep, Iface)) return "interface";
        else if (VN_IS(nodep, ParamTypeDType)) return "parameter type";
	else return nodep->prettyTypeName();
    }

    VSymEnt* rootEntp() const { return m_syms.rootp(); }
    VSymEnt* dunitEntp() const { return m_dunitEntp; }
    void checkDuplicate(VSymEnt* lookupSymp, AstNode* nodep, const string& name) {
	// Lookup the given name under current symbol table
	// Insert if not found
	// Report error if there's a duplicate
	//
	// Note we only check for conflicts at the same level; it's ok if one block hides another
	// We also wouldn't want to not insert it even though it's lower down
	VSymEnt* foundp = lookupSymp->findIdFlat(name);
	AstNode* fnodep = foundp ? foundp->nodep() : NULL;
	if (!fnodep) {
	    // Not found, will add in a moment.
	} else if (nodep==fnodep) {  // Already inserted.
	    // Good.
	} else if (foundp->imported()) {  // From package
	    // We don't throw VARHIDDEN as if the import is later the symbol table's import wouldn't warn
        } else if (VN_IS(nodep, Begin) && VN_IS(fnodep, Begin)
                   && VN_CAST(nodep, Begin)->generate()) {
	    // Begin: ... blocks often replicate under genif/genfor, so simply suppress duplicate checks
	    // See t_gen_forif.v for an example.
	} else {
	    UINFO(4,"name "<<name<<endl);  // Not always same as nodep->name
	    UINFO(4,"Var1 "<<nodep<<endl);
	    UINFO(4,"Var2 "<<fnodep<<endl);
	    if (nodep->type() == fnodep->type()) {
		nodep->v3error("Duplicate declaration of "<<nodeTextType(fnodep)<<": "<<nodep->prettyName()<<endl
			       <<fnodep->warnMore()<<"... Location of original declaration");
	    } else {
		nodep->v3error("Unsupported in C: "<<ucfirst(nodeTextType(nodep))<<" has the same name as "
			       <<nodeTextType(fnodep)<<": "<<nodep->prettyName()<<endl
			       <<fnodep->warnMore()<<"... Location of original declaration");
	    }
	}
    }
    void insertDUnit(AstNetlist* nodep) {
	// $unit on top scope
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTdunit se"<<cvtToHex(symp)<<endl);
	symp->parentp(rootEntp());  // Needed so backward search can find name of top module
	symp->fallbackp(NULL);
	rootEntp()->insert("$unit ",symp);  // Space so can never name conflict with user code
	//
	if (m_dunitEntp) nodep->v3fatalSrc("Call insertDUnit only once");
	m_dunitEntp = symp;
    }
    VSymEnt* insertTopCell(AstNodeModule* nodep, const string& scopename) {
	// Only called on the module at the very top of the hierarchy
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTtop se"<<cvtToHex(symp)<<"  "<<scopename<<" "<<nodep<<endl);
	symp->parentp(rootEntp());  // Needed so backward search can find name of top module
	symp->fallbackp(dunitEntp());  // Needed so can find $unit stuff
	nodep->user1p(symp);
	checkDuplicate(rootEntp(), nodep, nodep->origName());
	rootEntp()->insert(nodep->origName(),symp);
	if (forScopeCreation()) m_nameScopeSymMap.insert(make_pair(scopename, symp));
	return symp;
    }
    VSymEnt* insertCell(VSymEnt* abovep, VSymEnt* modSymp,
			AstCell* nodep, const string& scopename) {
	if (!abovep) nodep->v3fatalSrc("Null symbol table inserting node");
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTcel se"<<cvtToHex(symp)<<"  "<<scopename<<" above=se"<<cvtToHex(abovep)
              <<" mods=se"<<cvtToHex(modSymp)<<" node="<<nodep<<endl);
	symp->parentp(abovep);
	symp->fallbackp(dunitEntp());  // Needed so can find $unit stuff
	nodep->user1p(symp);
	if (nodep->modp()) nodep->modp()->user1p(symp);
	checkDuplicate(abovep, nodep, nodep->origName());
	abovep->reinsert(nodep->origName(), symp);
	if (forScopeCreation() && abovep != modSymp && !modSymp->findIdFlat(nodep->name())) {
	    // If it's foo_DOT_bar, we need to be able to find it under "foo_DOT_bar" too.
	    // Duplicates are possible, as until resolve generates might have 2 same cells under an if
	    modSymp->reinsert(nodep->name(), symp);
	}
	if (forScopeCreation()) m_nameScopeSymMap.insert(make_pair(scopename, symp));
	return symp;
    }
    VSymEnt* insertInline(VSymEnt* abovep, VSymEnt* modSymp,
			  AstCellInline* nodep, const string& basename) {
	// A fake point in the hierarchy, corresponding to an inlined module
	// This refrences to another Sym, and eventually resolves to a module with a prefix
	if (!abovep) nodep->v3fatalSrc("Null symbol table inserting node");
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTinl se"<<cvtToHex(symp)<<"  "<<basename<<" above=se"<<cvtToHex(abovep)
              <<" mods=se"<<cvtToHex(modSymp)<<" node="<<nodep<<endl);
	symp->parentp(abovep);
	symp->fallbackp(modSymp);
	symp->symPrefix(nodep->name()+"__DOT__");
	nodep->user1p(symp);
	checkDuplicate(abovep, nodep, nodep->name());
	abovep->reinsert(basename, symp);
	if (abovep != modSymp && !modSymp->findIdFlat(nodep->name())) {
	    // If it's foo_DOT_bar, we need to be able to find it under that too.
	    modSymp->reinsert(nodep->name(), symp);
	}
	return symp;
    }
    VSymEnt* insertBlock(VSymEnt* abovep, const string& name, AstNode* nodep, AstPackage* packagep) {
	// A fake point in the hierarchy, corresponding to a begin or function/task block
	// After we remove begins these will go away
	// Note we fallback to the symbol table of the parent, as we want to find variables there
	// However, cells walk the graph, so cells will appear under the begin/ftask itself
	if (!abovep) nodep->v3fatalSrc("Null symbol table inserting node");
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTblk se"<<cvtToHex(symp)<<"  above=se"<<cvtToHex(abovep)<<"  node="<<nodep<<endl);
	symp->parentp(abovep);
	symp->packagep(packagep);
	symp->fallbackp(abovep);
	nodep->user1p(symp);
	if (name != "") {
	    checkDuplicate(abovep, nodep, name);
	}
	// Duplicates are possible, as until resolve generates might have 2 same cells under an if
	abovep->reinsert(name, symp);
	return symp;
    }
    VSymEnt* insertSym(VSymEnt* abovep, const string& name, AstNode* nodep, AstPackage* packagep) {
	if (!abovep) nodep->v3fatalSrc("Null symbol table inserting node");
	VSymEnt* symp = new VSymEnt(&m_syms, nodep);
        UINFO(9,"      INSERTsym se"<<cvtToHex(symp)<<"  name='"<<name
              <<"' above=se"<<cvtToHex(abovep)<<"  node="<<nodep<<endl);
	// We don't remember the ent associated with each node, because we need a unique scope entry for each instantiation
	symp->packagep(packagep);
	symp->parentp(abovep);
	symp->fallbackp(abovep);
	nodep->user1p(symp);
	checkDuplicate(abovep, nodep, name);
	abovep->reinsert(name, symp);
	return symp;
    }
    static bool existsModScope(AstNodeModule* nodep) {
	return nodep->user1p()!=NULL;
    }
    static VSymEnt* getNodeSym(AstNode* nodep) {
	// Don't use this in ResolveVisitor, as we need to pick up the proper reference under each SCOPE
	VSymEnt* symp = nodep->user1u().toSymEnt();
	if (!symp) nodep->v3fatalSrc("Module/etc never assigned a symbol entry?");
	return symp;
    }
    VSymEnt* getScopeSym(AstScope* nodep) {
	NameScopeSymMap::iterator it = m_nameScopeSymMap.find(nodep->name());
	if (it == m_nameScopeSymMap.end()) {
	    nodep->v3fatalSrc("Scope never assigned a symbol entry?");
	}
	return it->second;
    }
    void implicitOkAdd(AstNodeModule* nodep, const string& varname) {
	// Mark the given variable name as being allowed to be implicitly declared
	if (nodep) {
	    ImplicitNameSet::iterator it = m_implicitNameSet.find(make_pair(nodep,varname));
	    if (it == m_implicitNameSet.end()) {
		m_implicitNameSet.insert(make_pair(nodep,varname));
	    }
	}
    }
    bool implicitOk(AstNodeModule* nodep, const string& varname) {
	return nodep
	    && (m_implicitNameSet.find(make_pair(nodep,varname)) != m_implicitNameSet.end());
    }

    // Track and later recurse interface modules
    void insertIfaceModSym(AstIface* nodep, VSymEnt* symp) {
	m_ifaceModSyms.push_back(make_pair(nodep, symp));
    }
    void computeIfaceModSyms();

    // Track and later insert interface references
    void insertIfaceVarSym(VSymEnt* symp) {  // Where sym is for a VAR of dtype IFACEREFDTYPE
	m_ifaceVarSyms.push_back(symp);
    }
    // Iface for a raw or arrayed iface
    static AstIfaceRefDType* ifaceRefFromArray(AstNodeDType* nodep) {
        AstIfaceRefDType* ifacerefp = VN_CAST(nodep, IfaceRefDType);
	if (!ifacerefp) {
            if (AstUnpackArrayDType* arrp = VN_CAST(nodep, UnpackArrayDType)) {
                ifacerefp = VN_CAST(arrp->subDTypep(), IfaceRefDType);
	    }
	}
	return ifacerefp;
    }
    void computeIfaceVarSyms() {
	for (IfaceVarSyms::iterator it = m_ifaceVarSyms.begin(); it != m_ifaceVarSyms.end(); ++it) {
	    VSymEnt* varSymp = *it;
            AstVar* varp = varSymp ? VN_CAST(varSymp->nodep(), Var) : NULL;
            UINFO(9, "  insAllIface se"<<cvtToHex(varSymp)<<" "<<varp<<endl);
	    AstIfaceRefDType* ifacerefp = ifaceRefFromArray(varp->subDTypep());
	    if (!ifacerefp) varp->v3fatalSrc("Non-ifacerefs on list!");
	    if (!ifacerefp->ifaceViaCellp()) {
		if (!ifacerefp->cellp()) {  // Probably a NotFoundModule, or a normal module if made mistake
		    ifacerefp->v3error("Cannot find file containing interface: "<<AstNode::prettyName(ifacerefp->ifaceName()));
		    continue;
		} else {
		    ifacerefp->v3fatalSrc("Unlinked interface");
		}
	    } else if (ifacerefp->ifaceViaCellp()->dead()) {
		ifacerefp->v3error("Parent cell's interface is not found: "<<AstNode::prettyName(ifacerefp->ifaceName()));
		continue;
	    }
	    VSymEnt* ifaceSymp = getNodeSym(ifacerefp->ifaceViaCellp());
	    VSymEnt* ifOrPortSymp = ifaceSymp;
	    // Link Modport names to the Modport Node under the Interface
	    if (ifacerefp->isModport()) {
		VSymEnt* foundp = ifaceSymp->findIdFallback(ifacerefp->modportName());
		bool ok = false;
		if (foundp) {
                    if (AstModport* modportp = VN_CAST(foundp->nodep(), Modport)) {
			UINFO(4,"Link Modport: "<<modportp<<endl);
			ifacerefp->modportp(modportp);
			ifOrPortSymp = foundp;
			ok = true;
		    }
		}
		if (!ok) ifacerefp->v3error("Modport not found under interface '"
					    <<ifacerefp->prettyName(ifacerefp->ifaceName())
					    <<"': "<<ifacerefp->prettyName(ifacerefp->modportName()));
	    }
	    // Alias won't expand until interfaces and modport names are known; see notes at top
	    insertScopeAlias(SAMN_IFTOP, varSymp, ifOrPortSymp);
	}
	m_ifaceVarSyms.clear();
    }

    void insertScopeAlias(SAMNum samn, VSymEnt* lhsp, VSymEnt* rhsp) {
	// Track and later insert scope aliases; an interface referenced by a child cell connecting to that interface
	// Typically lhsp=VAR w/dtype IFACEREF, rhsp=IFACE cell
        UINFO(9,"   insertScopeAlias se"<<cvtToHex(lhsp)<<" se"<<cvtToHex(rhsp)<<endl);
        if (VN_IS(rhsp->nodep(), Cell)
            && !VN_IS(VN_CAST(rhsp->nodep(), Cell)->modp(), Iface)) {
	    rhsp->nodep()->v3fatalSrc("Got a non-IFACE alias RHS");
	}
	m_scopeAliasMap[samn].insert(make_pair(lhsp, rhsp));
    }
    void computeScopeAliases() {
	UINFO(9,"computeIfaceAliases\n");
	for (int samn=0; samn<SAMN__MAX; ++samn) {
	    for (ScopeAliasMap::iterator it=m_scopeAliasMap[samn].begin();
		 it!=m_scopeAliasMap[samn].end(); ++it) {
		VSymEnt* lhsp = it->first;
		VSymEnt* srcp = lhsp;
		while (1) {  // Follow chain of aliases up to highest level non-alias
		    ScopeAliasMap::iterator it2 = m_scopeAliasMap[samn].find(srcp);
		    if (it2 != m_scopeAliasMap[samn].end()) { srcp = it2->second; continue; }
		    else break;
		}
		UINFO(9,"  iiasa: Insert alias se"<<lhsp<<" ("<<lhsp->nodep()->typeName()
		      <<") <- se"<<srcp<<" "<<srcp->nodep()<<endl);
		// srcp should be an interface reference pointing to the interface we want to import
		lhsp->importFromIface(symsp(), srcp);
		// Allow access to objects not permissible to be listed in a modport
                if (VN_IS(srcp->nodep(), Modport)) {
		    lhsp->importFromIface(symsp(), srcp->parentp(), true);
		}
	    }
	    //m_scopeAliasMap[samn].clear();  // Done with it, but put into debug file
	}
    }
private:
    VSymEnt* findWithAltFallback(VSymEnt* symp, const string& name, const string& altname) {
	VSymEnt* findp = symp->findIdFallback(name);
	if (findp) return findp;
	if (altname != "") {
	    UINFO(8,"     alt fallback\n");
	    findp = symp->findIdFallback(altname);
	}
	return findp;
    }
public:
    VSymEnt* findDotted(VSymEnt* lookupSymp, const string& dotname,
			string& baddot, VSymEnt*& okSymp) {
	// Given a dotted hierarchy name, return where in scope it is
	// Note when dotname=="" we just fall through and return lookupSymp
        UINFO(8,"    dottedFind se"<<cvtToHex(lookupSymp)<<" '"<<dotname<<"'"<<endl);
	bool firstId = true;
	string leftname = dotname;
	okSymp = lookupSymp;  // So can list bad scopes
	while (leftname != "") {  // foreach dotted part of xref name
	    string::size_type pos;
	    string ident;
            if ((pos = leftname.find('.')) != string::npos) {
		ident = leftname.substr(0,pos);
		leftname = leftname.substr(pos+1);
	    } else {
		ident = leftname;
		leftname = "";
	    }
	    baddot = ident;   // So user can see where they botched it
	    okSymp = lookupSymp;
            string altIdent;
	    if (m_forPrearray) {
		// GENFOR Begin is foo__BRA__##__KET__ after we've genloop unrolled,
		// but presently should be just "foo".
		// Likewise cell foo__[array] before we've expanded arrays is just foo
		if ((pos = ident.rfind("__BRA__")) != string::npos) {
		    altIdent = ident.substr(0,pos);
		}
	    }
	    UINFO(8,"         id "<<ident<<" alt "<<altIdent<<" left "<<leftname<<" at se"<<lookupSymp<<endl);
	    // Spec says; Look at existing module (cellnames then modname),
	    // then look up (inst name or modname)
	    if (firstId) {
		// Check this module - subcellnames
                AstCell* cellp = lookupSymp ? VN_CAST(lookupSymp->nodep(), Cell) : NULL;  // Replicated below
                AstCellInline* inlinep = lookupSymp ? VN_CAST(lookupSymp->nodep(), CellInline) : NULL;  // Replicated below
		if (VSymEnt* findSymp = findWithAltFallback(lookupSymp, ident, altIdent)) {
		    lookupSymp = findSymp;
		}
		// Check this module - cur modname
		else if ((cellp && cellp->modp()->origName() == ident)
			 || (inlinep && inlinep->origModName() == ident)) {}
		// Move up and check cellname + modname
		else {
		    bool crossedCell = false;  // Crossed a cell boundary
		    while (lookupSymp) {
			lookupSymp = lookupSymp->parentp();
                        cellp   = lookupSymp ? VN_CAST(lookupSymp->nodep(), Cell) : NULL;  // Replicated above
                        inlinep = lookupSymp ? VN_CAST(lookupSymp->nodep(), CellInline) : NULL;  // Replicated above
			if (lookupSymp) {
			    UINFO(9,"\t\tUp to "<<lookupSymp<<endl);
			    if (cellp || inlinep) {
				crossedCell = true;
			    }
			    if ((cellp && cellp->modp()->origName() == ident)
				|| (inlinep && inlinep->origModName() == ident)) {
				break;
			    }
			    else if (VSymEnt* findSymp = findWithAltFallback(lookupSymp, ident, altIdent)) {
				lookupSymp = findSymp;
                                if (crossedCell && VN_IS(lookupSymp->nodep(), Var)) {
				    UINFO(9,"\t\tNot found but matches var name in parent "<<lookupSymp<<endl);
				    return NULL;  // Not found (but happens to be var name in parent)
				}
				break;
			    }
			} else break;
		    }
		    if (!lookupSymp) return NULL;  // Not found
		}
	    } else { // Searching for middle submodule, must be a cell name
		if (VSymEnt* findSymp = findWithAltFallback(lookupSymp, ident, altIdent)) {
		    lookupSymp = findSymp;
		} else {
		    return NULL;  // Not found
		}
	    }
	    firstId = false;
	}
	return lookupSymp;
    }

    static string removeLastInlineScope(const string& name) {
	string out = name;
	string dot = "__DOT__";
	size_t dotPos = out.rfind(dot, out.size() - dot.length() - 2);
	if (dotPos == string::npos) {
	    return "";
	} else {
	    return out.erase(dotPos + dot.length(), string::npos);
	}
    }

    VSymEnt* findSymPrefixed(VSymEnt* lookupSymp, const string& dotname, string& baddot) {
	// Find symbol in given point in hierarchy, allowing prefix (post-Inline)
	// For simplicity lookupSymp may be passed NULL result from findDotted
	if (!lookupSymp) return NULL;
	UINFO(8,"\t\tfindSymPrefixed "<<dotname
              <<" under se"<<cvtToHex(lookupSymp)
	      <<((lookupSymp->symPrefix()=="") ? "" : " as ")
	      <<((lookupSymp->symPrefix()=="") ? "" : lookupSymp->symPrefix()+dotname)
	      <<"  at se"<<lookupSymp
	      <<endl);
	string prefix = lookupSymp->symPrefix();
	VSymEnt* foundp = NULL;
	while (!foundp) {
	    foundp = lookupSymp->findIdFallback(prefix + dotname);  // Might be NULL
	    if (prefix == "") {
		break;
	    }
	    prefix = removeLastInlineScope(prefix);
	}
	if (!foundp) baddot = dotname;
	return foundp;
    }
};

LinkDotState* LinkDotState::s_errorThisp = NULL;

//======================================================================

class LinkDotFindVisitor : public AstNVisitor {
    // STATE
    LinkDotState*	m_statep;	// State to pass between visitors, including symbol table
    AstPackage*		m_packagep;	// Current package
    VSymEnt*		m_modSymp;	// Symbol Entry for current module
    VSymEnt*		m_curSymp;	// Symbol Entry for current table, where to lookup/insert
    string		m_scope;	// Scope text
    AstBegin*		m_beginp;	// Current Begin/end block
    AstNodeFTask*	m_ftaskp;	// Current function/task
    bool		m_inGenerate;	// Inside a generate
    bool		m_inRecursion;	// Inside a recursive module
    int			m_paramNum;	// Parameter number, for position based connection
    int			m_beginNum;	// Begin block number, 0=none seen
    int			m_modBeginNum;	// Begin block number in module, 0=none seen

    // METHODS
    int debug() { return LinkDotState::debug(); }

    virtual AstConst* parseParamLiteral(FileLine* fl, const string& literal) {
	bool success = false;
        if (literal[0] == '"') {
	    // This is a string
            string v = literal.substr(1, literal.find('"', 1) - 1);
            V3Number n(V3Number::VerilogStringLiteral(), fl, v);
            return new AstConst(fl,n);
        } else if ((literal.find('.') != string::npos)
                   || (literal.find('e') != string::npos)) {
	    // This may be a real
            double v = V3ParseImp::parseDouble(literal.c_str(), literal.length(), &success);
            if (success) {
                return new AstConst(fl, AstConst::RealDouble(), v);
            }
        }
        if (!success) {
            // This is either an integer or an error
            // We first try to convert it as C literal. If strtol returns
            // 0 this is either an error or 0 was parsed. But in any case
            // we will try to parse it as a verilog literal, hence having
            // the false negative for 0 is okay. If anything remains in
            // the string after the number, this is invalid C and we try
            // the Verilog literal parser.
            char* endp;
            int v = strtol(literal.c_str(), &endp, 0);
            if ((v != 0) && (endp[0] == 0)) { // C literal
                V3Number n(fl, 32, v);
                return new AstConst(fl, n);
            } else { // Try a Verilog literal (fatals if not)
                V3Number n(fl, literal.c_str());
                return new AstConst(fl, n);
            }
        }
	return NULL;
    }

    // VISITs
    virtual void visit(AstNetlist* nodep) {
	// Process $unit or other packages
	// Not needed - dotted references not allowed from inside packages
        //for (AstNodeModule* nodep = v3Global.rootp()->modulesp(); nodep; nodep=VN_CAST(nodep->nextp(), NodeModule)) {
        //    if (VN_IS(nodep, Package)) {}}

	m_statep->insertDUnit(nodep);

	// First back iterate, to find all packages. Backward as must do base packages before using packages
        iterateChildrenBackwards(nodep);

	// The first module in the list is always the top module (sorted before this is called).
	// This may not be the module with isTop() set, as early in the steps,
	// wrapTop may have not been created yet.
	AstNodeModule* topmodp = nodep->modulesp();
	if (!topmodp) {
	    nodep->v3error("No top level module found");
	} else {
	    UINFO(8,"Top Module: "<<topmodp<<endl);
	    m_scope = "TOP";
	    m_curSymp = m_modSymp = m_statep->insertTopCell(topmodp, m_scope);
	    {
                iterate(topmodp);
	    }
	    m_scope = "";
	    m_curSymp = m_modSymp = NULL;
	}
    }
    virtual void visit(AstTypeTable* nodep) {}
    virtual void visit(AstNodeModule* nodep) {
	// Called on top module from Netlist, other modules from the cell creating them,
	// and packages
	UINFO(8,"   "<<nodep<<endl);
	// m_curSymp/m_modSymp maybe NULL for packages and non-top modules
	// Packages will be under top after the initial phases, but until then need separate handling
        bool standalonePkg = !m_modSymp && (m_statep->forPrearray() && VN_IS(nodep, Package));
	bool doit = (m_modSymp || standalonePkg);
	string oldscope = m_scope;
	VSymEnt* oldModSymp = m_modSymp;
	VSymEnt* oldCurSymp = m_curSymp;
        int      oldParamNum    = m_paramNum;
        int      oldBeginNum    = m_beginNum;
        int      oldModBeginNum = m_modBeginNum;
	if (doit && nodep->user2()) {
	    nodep->v3error("Unsupported: Identically recursive module (module instantiates itself, without changing parameters): "
			   <<AstNode::prettyName(nodep->origName()));
	} else if (doit) {
	    UINFO(4,"     Link Module: "<<nodep<<endl);
	    if (nodep->dead()) nodep->v3fatalSrc("Module in cell tree mislabeled as dead?");
	    VSymEnt* upperSymp = m_curSymp ? m_curSymp : m_statep->rootEntp();
            m_packagep = VN_CAST(nodep, Package);
	    if (standalonePkg) {
		if (m_packagep->isDollarUnit()) {
		    m_curSymp = m_modSymp = m_statep->dunitEntp();
		    nodep->user1p(m_curSymp);
		} else {
		    m_scope = nodep->name();
		    m_curSymp = m_modSymp = m_statep->insertBlock(upperSymp, nodep->name()+"::", nodep, m_packagep);
		    UINFO(9, "New module scope "<<m_curSymp<<endl);
		}
	    }
	    //
	    m_paramNum = 0;
	    m_beginNum = 0;
	    m_modBeginNum = 0;
	    // m_modSymp/m_curSymp for non-packages set by AstCell above this module
	    // Iterate
	    nodep->user2(true);
            iterateChildren(nodep);
	    nodep->user2(false);
	    nodep->user4(true);
	    // Interfaces need another pass when signals are resolved
            if (AstIface* ifacep = VN_CAST(nodep, Iface)) {
		m_statep->insertIfaceModSym(ifacep, m_curSymp);
	    }
	} else { //!doit
	    // Will be optimized away later
	    // Can't remove now, as our backwards iterator will throw up
	    UINFO(5, "Module not under any CELL or top - dead module: "<<nodep<<endl);
	}
	m_scope = oldscope;
	m_modSymp = oldModSymp;
	m_curSymp = oldCurSymp;
        m_paramNum    = oldParamNum;
        m_beginNum    = oldBeginNum;
        m_modBeginNum = oldModBeginNum;
	// Prep for next
	m_packagep = NULL;
    }
    virtual void visit(AstScope* nodep) {
	if (!m_statep->forScopeCreation()) v3fatalSrc("Scopes should only exist right after V3Scope");
	// Ignored.  Processed in next step
    }
    virtual void visit(AstCell* nodep) {
	UINFO(5,"   CELL under "<<m_scope<<" is "<<nodep<<endl);
	// Process XREFs/etc inside pins
	if (nodep->recursive() && m_inRecursion) return;
        iterateChildren(nodep);
	// Recurse in, preserving state
	string oldscope = m_scope;
	AstBegin* oldbeginp = m_beginp;
	VSymEnt* oldModSymp = m_modSymp;
	VSymEnt* oldCurSymp = m_curSymp;
	int oldParamNum = m_paramNum;
	bool oldRecursion = m_inRecursion;
	// Where do we add it?
	VSymEnt* aboveSymp = m_curSymp;
	string origname = AstNode::dedotName(nodep->name());
	string::size_type pos;
        if ((pos = origname.rfind('.')) != string::npos) {
	    // Flattened, find what CellInline it should live under
	    string scope = origname.substr(0,pos);
	    string baddot;
	    VSymEnt* okSymp;
	    aboveSymp = m_statep->findDotted(aboveSymp, scope, baddot, okSymp);
	    if (!aboveSymp) {
		nodep->v3fatalSrc("Can't find cell insertion point at '"<<baddot<<"' in: "<<nodep->prettyName());
	    }
	}
	{
	    m_scope = m_scope+"."+nodep->name();
	    m_curSymp = m_modSymp = m_statep->insertCell(aboveSymp, m_modSymp, nodep, m_scope);
	    m_beginp = NULL;
	    m_inRecursion = nodep->recursive();
	    // We don't report NotFoundModule, as may be a unused module in a generate
            if (nodep->modp()) iterate(nodep->modp());
	}
	m_scope = oldscope;
	m_beginp = oldbeginp;
	m_modSymp = oldModSymp;
	m_curSymp = oldCurSymp;
	m_paramNum = oldParamNum;
	m_inRecursion = oldRecursion;
    }
    virtual void visit(AstCellInline* nodep) {
	UINFO(5,"   CELLINLINE under "<<m_scope<<" is "<<nodep<<endl);
	VSymEnt* aboveSymp = m_curSymp;
	// If baz__DOT__foo__DOT__bar, we need to find baz__DOT__foo and add bar to it.
	string dottedname = nodep->name();
	string::size_type pos;
	if ((pos=dottedname.rfind("__DOT__")) != string::npos) {
	    string dotted = dottedname.substr(0, pos);
	    string ident  = dottedname.substr(pos+strlen("__DOT__"));
	    string baddot;
	    VSymEnt* okSymp;
	    aboveSymp = m_statep->findDotted(aboveSymp, dotted, baddot, okSymp);
	    if (!aboveSymp) {
		nodep->v3fatalSrc("Can't find cellinline insertion point at '"<<baddot<<"' in: "<<nodep->prettyName());
	    }
	    m_statep->insertInline(aboveSymp, m_modSymp, nodep, ident);
	} else {  // No __DOT__, just directly underneath
	    m_statep->insertInline(aboveSymp, m_modSymp, nodep, nodep->name());
	}
    }
    virtual void visit(AstDefParam* nodep) {
	nodep->user1p(m_curSymp);
        iterateChildren(nodep);
    }
    virtual void visit(AstGenerate* nodep) {
	// Begin: ... blocks often replicate under genif/genfor, so simply suppress duplicate checks
	// See t_gen_forif.v for an example.
	bool lastInGen = m_inGenerate;
	{
	    m_inGenerate = true;
            iterateChildren(nodep);
	}
	m_inGenerate = lastInGen;
    }
    virtual void visit(AstBegin* nodep) {
	UINFO(5,"   "<<nodep<<endl);
	// Rename "genblk"s to include a number
	if (m_statep->forPrimary() && !nodep->user4SetOnce()) {
	    if (nodep->name() == "genblk") {
		++m_beginNum;
		nodep->name(nodep->name()+cvtToStr(m_beginNum));
	    }
	    // Just for loop index, make special name.  The [00] is so it will "dearray" to same
	    // name as after we expand the GENFOR
	    if (nodep->genforp()) nodep->name(nodep->name());
	}
	// All blocks are numbered in the standard, IE we start with "genblk1" even if only one.
	if (nodep->name()=="" && nodep->unnamed()) {
	    // Unnamed blocks are only important when they contain var
	    // decls, so search for them. (Otherwise adding all the
	    // unnamed#'s would just confuse tracing variables in
	    // places such as tasks, where "task ...; begin ... end"
	    // are common.
	    for (AstNode* stmtp = nodep->stmtsp(); stmtp; stmtp=stmtp->nextp()) {
                if (VN_IS(stmtp, Var)) {
		    ++m_modBeginNum;
		    nodep->name("unnamedblk"+cvtToStr(m_modBeginNum));
		    break;
		}
	    }
	}
	int oldNum = m_beginNum;
	AstBegin* oldbegin = m_beginp;
	VSymEnt* oldCurSymp = m_curSymp;
	{
	    m_beginNum = 0;
	    m_beginp = nodep;
	    m_curSymp = m_statep->insertBlock(m_curSymp, nodep->name(), nodep, m_packagep);
	    m_curSymp->fallbackp(oldCurSymp);
	    // Iterate
            iterateChildren(nodep);
	}
	m_curSymp = oldCurSymp;
	m_beginp = oldbegin;
	m_beginNum = oldNum;
    }
    virtual void visit(AstNodeFTask* nodep) {
	// NodeTask: Remember its name for later resolution
	UINFO(5,"   "<<nodep<<endl);
	if (!m_curSymp || !m_modSymp) nodep->v3fatalSrc("Function/Task not under module?");
	// Remember the existing symbol table scope
	VSymEnt* oldCurSymp = m_curSymp;
	{
	    // Create symbol table for the task's vars
	    m_curSymp = m_statep->insertBlock(m_curSymp, nodep->name(), nodep, m_packagep);
	    m_curSymp->fallbackp(oldCurSymp);
	    // Convert the func's range to the output variable
	    // This should probably be done in the Parser instead, as then we could
	    // just attact normal signal attributes to it.
	    if (nodep->fvarp()
                && !VN_IS(nodep->fvarp(), Var)) {
                AstNodeDType* dtypep = VN_CAST(nodep->fvarp(), NodeDType);
                // If unspecified, function returns one bit; however when we support NEW() it could
                // also return the class reference.
                if (dtypep) dtypep->unlinkFrBack();
                else dtypep = new AstBasicDType(nodep->fileline(), AstBasicDTypeKwd::LOGIC);
                AstVar* newvarp = new AstVar(nodep->fileline(), AstVarType::VAR, nodep->name(),
                                             VFlagChildDType(), dtypep);  // Not dtype resolved yet
                newvarp->direction(VDirection::OUTPUT);
		newvarp->funcReturn(true);
		newvarp->trace(false);  // Not user visible
		newvarp->attrIsolateAssign(nodep->attrIsolateAssign());
		nodep->addFvarp(newvarp);
		// Explicit insert required, as the var name shadows the upper level's task name
		m_statep->insertSym(m_curSymp, newvarp->name(), newvarp, NULL/*packagep*/);
	    }
	    m_ftaskp = nodep;
            iterateChildren(nodep);
	    m_ftaskp = NULL;
	}
	m_curSymp = oldCurSymp;
    }
    virtual void visit(AstVar* nodep) {
	// Var: Remember its name for later resolution
	if (!m_curSymp || !m_modSymp) nodep->v3fatalSrc("Var not under module?");
        iterateChildren(nodep);
	if (!m_statep->forScopeCreation()) {
	    // Find under either a task or the module's vars
	    VSymEnt* foundp = m_curSymp->findIdFallback(nodep->name());
	    if (!foundp && m_modSymp && nodep->name() == m_modSymp->nodep()->name()) foundp = m_modSymp;  // Conflicts with modname?
            AstVar* findvarp = foundp ? VN_CAST(foundp->nodep(), Var) : NULL;
	    bool ins=false;
	    if (!foundp) {
		ins=true;
	    } else if (!findvarp && foundp && m_curSymp->findIdFlat(nodep->name())) {
		nodep->v3error("Unsupported in C: Variable has same name as "
			       <<LinkDotState::nodeTextType(foundp->nodep())<<": "<<nodep->prettyName());
	    } else if (findvarp != nodep) {
		UINFO(4,"DupVar: "<<nodep<<" ;; "<<foundp->nodep()<<endl);
                UINFO(4,"    found  cur=se"<<cvtToHex(m_curSymp)
                      <<" ;; parent=se"<<cvtToHex(foundp->parentp())<<endl);
		if (foundp && foundp->parentp() == m_curSymp  // Only when on same level
		    && !foundp->imported()) {  // and not from package
		    if ((findvarp->isIO() && nodep->isSignal())
			|| (findvarp->isSignal() && nodep->isIO())) {
			findvarp->combineType(nodep);
			nodep->fileline()->modifyStateInherit(nodep->fileline());
                        AstBasicDType* bdtypep = VN_CAST(findvarp->childDTypep(), BasicDType);
			if (bdtypep && bdtypep->implicit()) {
			    // Then have "input foo" and "real foo" so the dtype comes from the other side.
			    AstNodeDType* newdtypep = nodep->subDTypep();
			    if (!newdtypep || !nodep->childDTypep()) findvarp->v3fatalSrc("No child type?");
			    bdtypep->unlinkFrBack()->deleteTree();
			    newdtypep->unlinkFrBack();
			    findvarp->childDTypep(newdtypep);
			}
			nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
		    } else {
			nodep->v3error("Duplicate declaration of signal: "<<nodep->prettyName()<<endl
				       <<findvarp->warnMore()<<"... Location of original declaration");
		    }
		} else {
		    // User can disable the message at either point
		    if (!(m_ftaskp && m_ftaskp->dpiImport())
			&& (!m_ftaskp || m_ftaskp != foundp->nodep())  // Not the function's variable hiding function
			&& !nodep->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)
			&& !foundp->nodep()->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)) {
			nodep->v3warn(VARHIDDEN,"Declaration of signal hides declaration in upper scope: "<<nodep->prettyName()<<endl
				      <<foundp->nodep()->warnMore()<<"... Location of original declaration");
		    }
		    ins = true;
		}
	    }
	    if (ins) {
	        if (m_statep->forPrimary() && nodep->isGParam()
		    && (m_statep->rootEntp()->nodep() == m_modSymp->parentp()->nodep())) {
	            // This is the toplevel module. Check for command line overwrites of parameters
	            // We first search if the parameter is overwritten and then replace it with a
	            // new value. It will keep the same FileLine information.
	            if (v3Global.opt.hasParameter(nodep->name())) {
	                AstVar* newp = new AstVar(nodep->fileline(), AstVarType(AstVarType::GPARAM),
						  nodep->name(), nodep);
	                string svalue = v3Global.opt.parameter(nodep->name());
			if (AstNode* valuep = parseParamLiteral(nodep->fileline(), svalue)) {
			    newp->valuep(valuep);
			    UINFO(9,"       replace parameter "<<nodep<<endl);
			    UINFO(9,"       with "<<newp<<endl);
			    nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
			    nodep = newp;
			}
	            }
	        }
		VSymEnt* insp = m_statep->insertSym(m_curSymp, nodep->name(), nodep, m_packagep);
		if (m_statep->forPrimary() && nodep->isGParam()) {
		    m_paramNum++;
		    VSymEnt* symp = m_statep->insertSym(m_curSymp, "__paramNumber" + cvtToStr(m_paramNum),
							nodep, m_packagep);
		    symp->exported(false);
		}
		AstIfaceRefDType* ifacerefp = LinkDotState::ifaceRefFromArray(nodep->subDTypep());
		if (ifacerefp) {
		    // Can't resolve until interfaces and modport names are known; see notes at top
		    m_statep->insertIfaceVarSym(insp);
		}
	    }
	}
    }
    virtual void visit(AstTypedef* nodep) {
	// Remember its name for later resolution
	if (!m_curSymp) nodep->v3fatalSrc("Typedef not under module?");
        iterateChildren(nodep);
	m_statep->insertSym(m_curSymp, nodep->name(), nodep, m_packagep);
    }
    virtual void visit(AstParamTypeDType* nodep) {
	if (!m_curSymp) nodep->v3fatalSrc("Parameter type not under module?");
        iterateChildren(nodep);
	m_statep->insertSym(m_curSymp, nodep->name(), nodep, m_packagep);
    }
    virtual void visit(AstCFunc* nodep) {
	// For dotted resolution, ignore all AstVars under functions, otherwise shouldn't exist
	if (m_statep->forScopeCreation()) nodep->v3fatalSrc("No CFuncs expected in tree yet");
    }
    virtual void visit(AstEnumItem* nodep) {
	// EnumItem: Remember its name for later resolution
        iterateChildren(nodep);
	// Find under either a task or the module's vars
	VSymEnt* foundp = m_curSymp->findIdFallback(nodep->name());
	if (!foundp && m_modSymp && nodep->name() == m_modSymp->nodep()->name()) foundp = m_modSymp;  // Conflicts with modname?
        AstEnumItem* findvarp = foundp ? VN_CAST(foundp->nodep(), EnumItem) : NULL;
	bool ins=false;
	if (!foundp) {
	    ins=true;
	} else if (findvarp != nodep) {
	    UINFO(4,"DupVar: "<<nodep<<" ;; "<<foundp<<endl);
	    if (foundp && foundp->parentp() == m_curSymp  // Only when on same level
		&& !foundp->imported()) {  // and not from package
		nodep->v3error("Duplicate declaration of enum value: "<<nodep->prettyName()<<endl
			       <<findvarp->warnMore()<<"... Location of original declaration");
	    } else {
		// User can disable the message at either point
		if (!nodep->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)
		    && !foundp->nodep()->fileline()->warnIsOff(V3ErrorCode::VARHIDDEN)) {
		    nodep->v3warn(VARHIDDEN,"Declaration of enum value hides declaration in upper scope: "<<nodep->prettyName()<<endl
				  <<foundp->nodep()->warnMore()<<"... Location of original declaration");
		}
		ins = true;
	    }
	}
	if (ins) {
	    m_statep->insertSym(m_curSymp, nodep->name(), nodep, m_packagep);
	}
    }
    virtual void visit(AstPackageImport* nodep) {
	UINFO(4,"  Link: "<<nodep<<endl);
	VSymEnt* srcp = m_statep->getNodeSym(nodep->packagep());
        if (nodep->name()=="*") {
            if (m_curSymp == m_statep->dunitEntp()) {
                nodep->v3warn(IMPORTSTAR,"Import::* in $unit scope may pollute global namespace");
            }
        } else {
	    VSymEnt* impp = srcp->findIdFlat(nodep->name());
	    if (!impp) {
		nodep->v3error("Import object not found: "<<nodep->packagep()->prettyName()<<"::"<<nodep->prettyName());
	    }
	}
	m_curSymp->importFromPackage(m_statep->symsp(), srcp, nodep->name());
	UINFO(9,"    Link Done: "<<nodep<<endl);
	// No longer needed, but can't delete until any multi-instantiated modules are expanded
    }
    virtual void visit(AstPackageExport* nodep) {
	UINFO(9,"  Link: "<<nodep<<endl);
	VSymEnt* srcp = m_statep->getNodeSym(nodep->packagep());
	if (nodep->name()!="*") {
	    VSymEnt* impp = srcp->findIdFlat(nodep->name());
	    if (!impp) {
		nodep->v3error("Export object not found: "<<nodep->packagep()->prettyName()<<"::"<<nodep->prettyName());
	    }
	}
	m_curSymp->exportFromPackage(m_statep->symsp(), srcp, nodep->name());
	UINFO(9,"    Link Done: "<<nodep<<endl);
	// No longer needed, but can't delete until any multi-instantiated modules are expanded
    }
    virtual void visit(AstPackageExportStarStar* nodep) {
	UINFO(4,"  Link: "<<nodep<<endl);
	m_curSymp->exportStarStar(m_statep->symsp());
	// No longer needed, but can't delete until any multi-instantiated modules are expanded
    }

    virtual void visit(AstNode* nodep) {
	// Default: Just iterate
        iterateChildren(nodep);
    }

public:
    // CONSTUCTORS
    LinkDotFindVisitor(AstNetlist* rootp, LinkDotState* statep) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_packagep = NULL;
	m_curSymp = m_modSymp = NULL;
	m_statep = statep;
	m_beginp = NULL;
	m_ftaskp = NULL;
	m_inGenerate = false;
	m_inRecursion = false;
	m_paramNum = 0;
	m_beginNum = 0;
	m_modBeginNum = 0;
	//
        iterate(rootp);
    }
    virtual ~LinkDotFindVisitor() {}
};

//======================================================================

class LinkDotParamVisitor : public AstNVisitor {
private:
    // NODE STATE
    // Cleared on global
    //  *::user1p()		-> See LinkDotState
    //  *::user2p()		-> See LinkDotState
    //  *::user4()		-> See LinkDotState

    // STATE
    LinkDotState*	m_statep;	// State to pass between visitors, including symbol table
    AstNodeModule*	m_modp;		// Current module

    int debug() { return LinkDotState::debug(); }

    void pinImplicitExprRecurse(AstNode* nodep) {
	// Under a pin, Check interconnect expression for a pin reference or a concat.
	// Create implicit variable as needed
        if (VN_IS(nodep, Dot)) {  // Not creating a simple implied type,
	    // and implying something else would just confuse later errors
	}
        else if (VN_IS(nodep, VarRef) || VN_IS(nodep, ParseRef)) {
	    // To prevent user errors, we should only do single bit
	    // implicit vars, however some netlists (MIPS) expect single
	    // bit implicit wires to get created with range 0:0 etc.
	    m_statep->implicitOkAdd(m_modp, nodep->name());
	}
	// These are perhaps a little too generous, as a SELect of siga[sigb]
	// perhaps shouldn't create an implicit variable.  But, we've warned...
	else {
	    if (nodep->op1p()) pinImplicitExprRecurse(nodep->op1p());
	    if (nodep->op2p()) pinImplicitExprRecurse(nodep->op2p());
	    if (nodep->op3p()) pinImplicitExprRecurse(nodep->op3p());
	    if (nodep->op4p()) pinImplicitExprRecurse(nodep->op4p());
	    if (nodep->nextp()) pinImplicitExprRecurse(nodep->nextp());
	}
    }

    // VISITs
    virtual void visit(AstTypeTable* nodep) {}
    virtual void visit(AstNodeModule* nodep) {
	UINFO(5,"   "<<nodep<<endl);
	if (nodep->dead() || !nodep->user4()) {
	    UINFO(4,"Mark dead module "<<nodep<<endl);
	    if (!m_statep->forPrearray()) nodep->v3fatalSrc("Dead module persisted past where should have removed");
	    // Don't remove now, because we may have a tree of parameterized modules with VARXREFs into the deleted module region
	    // V3Dead should cleanup.
	    // Downstream visitors up until V3Dead need to check for nodep->dead.
	    nodep->dead(true);
	} else {
	    m_modp = nodep;
            iterateChildren(nodep);
	    m_modp = NULL;
	}
    }
    virtual void visit(AstPin* nodep) {
	// Pin: Link to submodule's port
	// Deal with implicit definitions - do before Resolve visitor as may be referenced above declaration
	if (nodep->exprp() // Else specifically unconnected pin
	    && !nodep->svImplicit()) {   // SV 19.11.3: .name pins don't allow implicit decls
	    pinImplicitExprRecurse(nodep->exprp());
	}
    }
    virtual void visit(AstDefParam* nodep) {
        iterateChildren(nodep);
	nodep->v3warn(DEFPARAM,"Suggest replace defparam with Verilog 2001 #(."<<nodep->prettyName()<<"(...etc...))");
	VSymEnt* foundp = m_statep->getNodeSym(nodep)->findIdFallback(nodep->path());
        AstCell* cellp = foundp ? VN_CAST(foundp->nodep(), Cell) : NULL;
	if (!cellp) {
	    nodep->v3error("In defparam, cell "<<nodep->path()<<" never declared");
	} else {
	    AstNode* exprp = nodep->rhsp()->unlinkFrBack();
	    UINFO(9,"Defparam cell "<<nodep->path()<<"."<<nodep->name()
		  <<" attach-to "<<cellp
		  <<"  <= "<<exprp<<endl);
	    // Don't need to check the name of the defparam exists.  V3Param does.
            AstPin* pinp = new AstPin(nodep->fileline(),
                                      -1,  // Pin# not relevant
                                      nodep->name(),
                                      exprp);
	    cellp->addParamsp(pinp);
	    nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
	}
    }
    virtual void visit(AstPort* nodep) {
	// Port: Stash the pin number
	// Need to set pin numbers after varnames are created
	// But before we do the final resolution based on names
	VSymEnt* foundp = m_statep->getNodeSym(m_modp)->findIdFlat(nodep->name());
        AstVar* refp = foundp ? VN_CAST(foundp->nodep(), Var) : NULL;
	if (!refp) {
	    nodep->v3error("Input/output/inout declaration not found for port: "<<nodep->prettyName());
	} else if (!refp->isIO() && !refp->isIfaceRef()) {
	    nodep->v3error("Pin is not an in/out/inout/interface: "<<nodep->prettyName());
	} else {
	    refp->user4(true);
	    VSymEnt* symp = m_statep->insertSym(m_statep->getNodeSym(m_modp),
						"__pinNumber"+cvtToStr(nodep->pinNum()), refp, NULL/*packagep*/);
	    symp->exported(false);
	}
	// Ports not needed any more
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstAssignW* nodep) {
	// Deal with implicit definitions
	// We used to nodep->allowImplicit() here, but it turns out
	// normal "assigns" can also make implicit wires.  Yuk.
	pinImplicitExprRecurse(nodep->lhsp());
        iterateChildren(nodep);
    }
    virtual void visit(AstAssignAlias* nodep) {
	// tran gates need implicit creation
	// As VarRefs don't exist in forPrimary, sanity check
	if (m_statep->forPrimary()) nodep->v3fatalSrc("Assign aliases unexpected pre-dot");
        if (AstVarRef* forrefp = VN_CAST(nodep->lhsp(), VarRef)) {
	    pinImplicitExprRecurse(forrefp);
	}
        if (AstVarRef* forrefp = VN_CAST(nodep->rhsp(), VarRef)) {
	    pinImplicitExprRecurse(forrefp);
	}
        iterateChildren(nodep);
    }
    virtual void visit(AstImplicit* nodep) {
	// Unsupported gates need implicit creation
	pinImplicitExprRecurse(nodep);
	// We're done with implicit gates
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstNode* nodep) {
	// Default: Just iterate
        iterateChildren(nodep);
    }

public:
    // CONSTUCTORS
    LinkDotParamVisitor(AstNetlist* rootp, LinkDotState* statep) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_statep = statep;
	m_modp = NULL;
	//
        iterate(rootp);
    }
    virtual ~LinkDotParamVisitor() {}
};


//======================================================================

class LinkDotScopeVisitor : public AstNVisitor {

    // STATE
    LinkDotState*	m_statep;	// State to pass between visitors, including symbol table
    AstScope*		m_scopep;	// The current scope
    VSymEnt*		m_modSymp;	// Symbol entry for current module

    int debug() { return LinkDotState::debug(); }

    // VISITs
    virtual void visit(AstNetlist* nodep) {
	// Recurse..., backward as must do packages before using packages
        iterateChildrenBackwards(nodep);
    }
    virtual void visit(AstScope* nodep) {
	UINFO(8,"  SCOPE "<<nodep<<endl);
	if (!m_statep->forScopeCreation()) v3fatalSrc("Scopes should only exist right after V3Scope");
	// Using the CELL names, we created all hierarchy.  We now need to match this Scope
	// up with the hierarchy created by the CELL names.
	m_modSymp = m_statep->getScopeSym(nodep);
	m_scopep = nodep;
        iterateChildren(nodep);
	m_modSymp = NULL;
	m_scopep = NULL;
    }
    virtual void visit(AstVarScope* nodep) {
	if (!nodep->varp()->isFuncLocal()) {
	    VSymEnt* varSymp = m_statep->insertSym(m_modSymp, nodep->varp()->name(), nodep, NULL);
	    if (nodep->varp()->isIfaceRef()
		&& nodep->varp()->isIfaceParent()) {
		UINFO(9,"Iface parent ref var "<<nodep->varp()->name()<<" "<<nodep<<endl);
		// Find the interface cell the var references
		AstIfaceRefDType* dtypep = LinkDotState::ifaceRefFromArray(nodep->varp()->dtypep());
		if (!dtypep) nodep->v3fatalSrc("Non AstIfaceRefDType on isIfaceRef() var");
		UINFO(9,"Iface parent dtype "<<dtypep<<endl);
		string ifcellname = dtypep->cellName();
		string baddot; VSymEnt* okSymp;
		VSymEnt* cellSymp = m_statep->findDotted(m_modSymp, ifcellname, baddot, okSymp);
		if (!cellSymp) nodep->v3fatalSrc("No symbol for interface cell: " <<nodep->prettyName(ifcellname));
                UINFO(5, "       Found interface cell: se"<<cvtToHex(cellSymp)<<" "<<cellSymp->nodep()<<endl);
		if (dtypep->modportName()!="") {
		    VSymEnt* mpSymp = m_statep->findDotted(m_modSymp, ifcellname, baddot, okSymp);
		    if (!mpSymp) { nodep->v3fatalSrc("No symbol for interface modport: " <<nodep->prettyName(dtypep->modportName())); }
		    else cellSymp = mpSymp;
                    UINFO(5, "       Found modport cell: se"<<cvtToHex(cellSymp)<<" "<<mpSymp->nodep()<<endl);
		}
		// Interface reference; need to put whole thing into symtable, but can't clone it now
		// as we may have a later alias for it.
		m_statep->insertScopeAlias(LinkDotState::SAMN_IFTOP, varSymp, cellSymp);
	    }
	}
    }
    virtual void visit(AstNodeFTask* nodep) {
	VSymEnt* symp = m_statep->insertBlock(m_modSymp, nodep->name(), nodep, NULL);
	symp->fallbackp(m_modSymp);
	// No recursion, we don't want to pick up variables
    }
    virtual void visit(AstAssignAlias* nodep) {
	// Track aliases created by V3Inline; if we get a VARXREF(aliased_from)
	// we'll need to replace it with a VARXREF(aliased_to)
	if (debug()>=9) nodep->dumpTree(cout,"-\t\t\t\talias: ");
        AstVarScope* fromVscp = VN_CAST(nodep->lhsp(), VarRef)->varScopep();
        AstVarScope* toVscp   = VN_CAST(nodep->rhsp(), VarRef)->varScopep();
	if (!fromVscp || !toVscp) nodep->v3fatalSrc("Bad alias scopes");
	fromVscp->user2p(toVscp);
        iterateChildren(nodep);
    }
    virtual void visit(AstAssignVarScope* nodep) {
	UINFO(5,"ASSIGNVARSCOPE  "<<nodep<<endl);
	if (debug()>=9) nodep->dumpTree(cout,"-\t\t\t\tavs: ");
	VSymEnt* rhsSymp;
	{
            AstVarRef* refp = VN_CAST(nodep->rhsp(), VarRef);
            AstVarXRef* xrefp = VN_CAST(nodep->rhsp(), VarXRef);
	    if (!refp && !xrefp) nodep->v3fatalSrc("Unsupported: Non Var(X)Ref attached to interface pin");
	    string inl = (xrefp && xrefp->inlinedDots().size()) ? (xrefp->inlinedDots() + "__DOT__") : "";
	    VSymEnt* symp = NULL;
	    string scopename;
	    while (!symp) {
		scopename = refp ? refp->name() : (inl.size() ? (inl + xrefp->name()) : xrefp->name());
		string baddot; VSymEnt* okSymp;
		symp = m_statep->findDotted(m_modSymp, scopename, baddot, okSymp);
		if (inl == "")
		    break;
		inl = LinkDotState::removeLastInlineScope(inl);
	    }
	    if (!symp) UINFO(9,"No symbol for interface alias rhs ("<<string(refp?"VARREF ":"VARXREF ")<<scopename<<")"<<endl);
	    if (!symp) nodep->v3fatalSrc("No symbol for interface alias rhs");
            UINFO(5, "       Found a linked scope RHS: "<<scopename<<"  se"<<cvtToHex(symp)<<" "<<symp->nodep()<<endl);
	    rhsSymp = symp;
	}
	VSymEnt* lhsSymp;
	{
            const AstVarXRef* xrefp = VN_CAST(nodep->lhsp(), VarXRef);
            const AstVarRef* refp = VN_CAST(nodep->lhsp(), VarRef);

	    if (!refp && !xrefp) nodep->v3fatalSrc("Unsupported: Non Var(X)Ref attached to interface pin");
	    string scopename = refp ? refp->varp()->name() : xrefp->dotted()+"."+xrefp->name();
	    string baddot; VSymEnt* okSymp;
	    VSymEnt* symp = m_statep->findDotted(m_modSymp, scopename, baddot, okSymp);
	    if (!symp) nodep->v3fatalSrc("No symbol for interface alias lhs");
            UINFO(5, "       Found a linked scope LHS: "<<scopename<<"  se"<<cvtToHex(symp)<<" "<<symp->nodep()<<endl);
	    lhsSymp = symp;
	}
	// Remember the alias - can't do it yet because we may have additional symbols to be added,
	// or maybe an alias of an alias
	m_statep->insertScopeAlias(LinkDotState::SAMN_IFTOP, lhsSymp, rhsSymp);
	// We have stored the link, we don't need these any more
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    // For speed, don't recurse things that can't have scope
    // Note we allow AstNodeStmt's as generates may be under them
    virtual void visit(AstCell*) {}
    virtual void visit(AstVar*) {}
    virtual void visit(AstNodeMath*) {}
    virtual void visit(AstNode* nodep) {
	// Default: Just iterate
        iterateChildren(nodep);
    }

public:
    // CONSTUCTORS
    LinkDotScopeVisitor(AstNetlist* rootp, LinkDotState* statep) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_modSymp = NULL;
	m_scopep = NULL;
	m_statep = statep;
	//
        iterate(rootp);
    }
    virtual ~LinkDotScopeVisitor() {}
};

//======================================================================

// Iterate an interface to resolve modports
class LinkDotIfaceVisitor : public AstNVisitor {
    // STATE
    LinkDotState*	m_statep;	// State to pass between visitors, including symbol table
    VSymEnt*		m_curSymp;	// Symbol Entry for current table, where to lookup/insert

    // METHODS
    int debug() { return LinkDotState::debug(); }

    // VISITs
    virtual void visit(AstModport* nodep) {
	// Modport: Remember its name for later resolution
	UINFO(5,"   fiv: "<<nodep<<endl);
	VSymEnt* oldCurSymp = m_curSymp;
	{
	    // Create symbol table for the vars
	    m_curSymp = m_statep->insertBlock(m_curSymp, nodep->name(), nodep, NULL);
	    m_curSymp->fallbackp(oldCurSymp);
            iterateChildren(nodep);
	}
	m_curSymp = oldCurSymp;
    }
    virtual void visit(AstModportFTaskRef* nodep) {
	UINFO(5,"   fif: "<<nodep<<endl);
        iterateChildren(nodep);
	if (nodep->isExport()) nodep->v3error("Unsupported: modport export");
	VSymEnt* symp = m_curSymp->findIdFallback(nodep->name());
	if (!symp) {
	    nodep->v3error("Modport item not found: "<<nodep->prettyName());
        } else if (AstNodeFTask* ftaskp = VN_CAST(symp->nodep(), NodeFTask)) {
	    // Make symbol under modport that points at the _interface_'s var, not the modport.
	    nodep->ftaskp(ftaskp);
	    VSymEnt* subSymp = m_statep->insertSym(m_curSymp, nodep->name(), ftaskp, NULL/*package*/);
	    m_statep->insertScopeAlias(LinkDotState::SAMN_MODPORT, subSymp, symp);
	} else {
	    nodep->v3error("Modport item is not a function/task: "<<nodep->prettyName());
	}
	if (m_statep->forScopeCreation()) {
	    // Done with AstModportFTaskRef.
	    // Delete to prevent problems if we dead-delete pointed to ftask
	    nodep->unlinkFrBack(); pushDeletep(nodep); VL_DANGLING(nodep);
	}
    }
    virtual void visit(AstModportVarRef* nodep) {
	UINFO(5,"   fiv: "<<nodep<<endl);
        iterateChildren(nodep);
	VSymEnt* symp = m_curSymp->findIdFallback(nodep->name());
	if (!symp) {
	    nodep->v3error("Modport item not found: "<<nodep->prettyName());
        } else if (AstVar* varp = VN_CAST(symp->nodep(), Var)) {
	    // Make symbol under modport that points at the _interface_'s var via the modport.
	    // (Need modport still to test input/output markings)
	    nodep->varp(varp);
	    m_statep->insertSym(m_curSymp, nodep->name(), nodep, NULL/*package*/);
        } else if (AstVarScope* vscp = VN_CAST(symp->nodep(), VarScope)) {
	    // Make symbol under modport that points at the _interface_'s var, not the modport.
	    nodep->varp(vscp->varp());
	    m_statep->insertSym(m_curSymp, nodep->name(), vscp, NULL/*package*/);
	} else {
	    nodep->v3error("Modport item is not a variable: "<<nodep->prettyName());
	}
	if (m_statep->forScopeCreation()) {
	    // Done with AstModportVarRef.
	    // Delete to prevent problems if we dead-delete pointed to variable
	    nodep->unlinkFrBack(); pushDeletep(nodep); VL_DANGLING(nodep);
	}
    }
    virtual void visit(AstNode* nodep) {
	// Default: Just iterate
        iterateChildren(nodep);
    }

public:
    // CONSTUCTORS
    LinkDotIfaceVisitor(AstIface* nodep, VSymEnt* curSymp, LinkDotState* statep) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_curSymp = curSymp;
	m_statep = statep;
        iterate(nodep);
    }
    virtual ~LinkDotIfaceVisitor() {}
};

void LinkDotState::computeIfaceModSyms() {
    for (IfaceModSyms::iterator it=m_ifaceModSyms.begin(); it!=m_ifaceModSyms.end(); ++it) {
	AstIface* nodep = it->first;
	VSymEnt* symp = it->second;
	LinkDotIfaceVisitor(nodep, symp, this);
    }
    m_ifaceModSyms.clear();
}

//======================================================================

class LinkDotResolveVisitor : public AstNVisitor {
private:
    // NODE STATE
    // Cleared on global
    //  *::user1p()		-> See LinkDotState
    //  *::user2p()		-> See LinkDotState
    //  *::user3()		// bool.	  Processed
    //  *::user4()		-> See LinkDotState
    // Cleared on Cell
    //  AstVar::user5()		// bool.	  True if pin used in this cell
    AstUser3InUse	m_inuser3;
    AstUser5InUse	m_inuser5;

    // TYPES
    enum DotPosition { DP_NONE=0,	// Not under a DOT
		       DP_PACKAGE,	// {package}:: DOT
		       DP_SCOPE,	// [DOT...] {scope-or-var} DOT
		       DP_FINAL,	// [DOT...] {var-or-func-or-dtype} with no following dots
		       DP_MEMBER };	// DOT {member-name} [DOT...]

    // STATE
    LinkDotState*	m_statep;	// State, including dotted symbol table
    VSymEnt*		m_curSymp;	// SymEnt for current lookup point
    VSymEnt*		m_modSymp;	// SymEnt for current module
    VSymEnt*		m_pinSymp;	// SymEnt for pin lookups
    AstCell*		m_cellp;	// Current cell
    AstNodeModule*	m_modp;		// Current module
    AstNodeFTask* 	m_ftaskp;	// Current function/task
    int			m_modportNum;	// Uniqueify modport numbers

    struct DotStates {
	DotPosition	m_dotPos;	// Scope part of dotted resolution
	VSymEnt*	m_dotSymp;	// SymEnt for dotted AstParse lookup
	AstDot*		m_dotp;		// Current dot
	bool		m_unresolved;	// Unresolved, needs help from V3Param
	AstNode*	m_unlinkedScope;// Unresolved scope, needs corresponding VarXRef
	bool		m_dotErr;	// Error found in dotted resolution, ignore upwards
	string		m_dotText;	// String of dotted names found in below parseref
	DotStates() { init(NULL); }
	~DotStates() {}
	void init(VSymEnt* curSymp) {
	    m_dotPos = DP_NONE; m_dotSymp = curSymp; m_dotp = NULL; m_dotErr = false; m_dotText = "";
	    m_unresolved = false; m_unlinkedScope = NULL;
	}
	string ascii() const {
	    static const char* const names[] = { "NONE","PACKAGE","SCOPE","FINAL","MEMBER" };
            std::ostringstream sstr;
	    sstr<<"ds="<<names[m_dotPos];
            sstr<<"  dse"<<cvtToHex(m_dotSymp);
	    sstr<<"  txt="<<m_dotText;
	    sstr<<"  unr="<<m_unresolved;
	    return sstr.str();
	}
    } m_ds;  // State to preserve across recursions

    int debug() { return LinkDotState::debug(); }

    // METHODS - Variables
    void createImplicitVar(VSymEnt* lookupSymp, AstVarRef* nodep, AstNodeModule* modp, VSymEnt* moduleSymp, bool noWarn) {
	// Create implicit after warning
	if (!nodep->varp()) {
	    if (!noWarn) {
		if (nodep->fileline()->warnIsOff(V3ErrorCode::I_DEF_NETTYPE_WIRE)) {
		    nodep->v3error("Signal definition not found, and implicit disabled with `default_nettype: "<<nodep->prettyName());
		} else {
		    nodep->v3warn(IMPLICIT,"Signal definition not found, creating implicitly: "<<nodep->prettyName());
		}
	    }
            AstVar* newp = new AstVar(nodep->fileline(), AstVarType::WIRE,
                                      nodep->name(), VFlagLogicPacked(), 1);
	    newp->trace(modp->modTrace());
	    nodep->varp(newp);
	    modp->addStmtp(newp);
	    // Link it to signal list, must add the variable under the module; current scope might be lower now
	    m_statep->insertSym(moduleSymp, newp->name(), newp, NULL/*packagep*/);
	}
    }
    AstVar* foundToVarp(const VSymEnt* symp, AstNode* nodep, bool lvalue) {
        // Return a variable if possible, auto converting a modport to variable
        if (!symp) {
            return NULL;
        } else if (VN_IS(symp->nodep(), Var)) {
            return VN_CAST(symp->nodep(), Var);
        } else if (VN_IS(symp->nodep(), ModportVarRef)) {
            AstModportVarRef* snodep = VN_CAST(symp->nodep(), ModportVarRef);
            AstVar* varp = snodep->varp();
            if (lvalue && snodep->direction().isReadOnly()) {
                nodep->v3error("Attempt to drive input-only modport: "<<nodep->prettyName());
            } // else other simulators don't warn about reading, and IEEE doesn't say illegal
            return varp;
        } else {
            return NULL;
        }
    }
    void taskFuncSwapCheck(AstNodeFTaskRef* nodep) {
        if (nodep->taskp() && VN_IS(nodep->taskp(), Task)
            && VN_IS(nodep, FuncRef)) nodep->v3error("Illegal call of a task as a function: "<<nodep->prettyName());
    }
    inline void checkNoDot(AstNode* nodep) {
	if (VL_UNLIKELY(m_ds.m_dotPos != DP_NONE)) {
	    //UINFO(9,"ds="<<m_ds.ascii()<<endl);
            nodep->v3error("Syntax Error: Not expecting "<<nodep->type()<<" under a "
                           <<nodep->backp()->type()<<" in dotted expression");
	    m_ds.m_dotErr = true;
	}
    }
    AstVar* makeIfaceModportVar(FileLine* fl, AstCell* cellp, AstIface* ifacep, AstModport* modportp) {
	// Create iface variable, using duplicate var when under same module scope
	string varName = ifacep->name()+"__Vmp__"+modportp->name()+"__Viftop"+cvtToStr(++m_modportNum);
	AstIfaceRefDType* idtypep = new AstIfaceRefDType(fl, cellp->name(), ifacep->name(), modportp->name());
	idtypep->cellp(cellp);
	AstVar* varp = new AstVar(fl, AstVarType::IFACEREF, varName, VFlagChildDType(), idtypep);
	varp->isIfaceParent(true);
	m_modp->addStmtp(varp);
	return varp;
    }
    void markAndCheckPinDup(AstNode* nodep, AstNode* refp, const char* whatp) {
	if (refp->user5p() && refp->user5p()!=nodep) {
	    nodep->v3error("Duplicate "<<whatp<<" connection: "<<nodep->prettyName()<<endl
			   <<refp->user5p()->warnMore()
			   <<"... Location of original "<<whatp<<" connection");
	} else {
	    refp->user5p(nodep);
	}
    }

    // VISITs
    virtual void visit(AstNetlist* nodep) {
	// Recurse..., backward as must do packages before using packages
        iterateChildrenBackwards(nodep);
    }
    virtual void visit(AstTypeTable* nodep) {}
    virtual void visit(AstNodeModule* nodep) {
	if (nodep->dead()) return;
	checkNoDot(nodep);
	UINFO(8,"  "<<nodep<<endl);
	m_ds.init(m_curSymp);
	m_ds.m_dotSymp = m_curSymp = m_modSymp = m_statep->getNodeSym(nodep);  // Until overridden by a SCOPE
	m_cellp = NULL;
	m_modp = nodep;
	m_modportNum = 0;
        iterateChildren(nodep);
	m_modp = NULL;
	m_ds.m_dotSymp = m_curSymp = m_modSymp = NULL;
    }
    virtual void visit(AstScope* nodep) {
	UINFO(8,"   "<<nodep<<endl);
	VSymEnt* oldModSymp = m_modSymp;
	VSymEnt* oldCurSymp = m_curSymp;
	checkNoDot(nodep);
	m_ds.m_dotSymp = m_curSymp = m_modSymp = m_statep->getScopeSym(nodep);
        iterateChildren(nodep);
	m_ds.m_dotSymp = m_curSymp = m_modSymp = NULL;
	m_modSymp = oldModSymp;
	m_curSymp = oldCurSymp;
    }
    virtual void visit(AstCellInline* nodep) {
	checkNoDot(nodep);
	if (m_statep->forScopeCreation()) {
	    nodep->unlinkFrBack(); pushDeletep(nodep); VL_DANGLING(nodep);
	}
    }
    virtual void visit(AstCell* nodep) {
	// Cell: Recurse inside or cleanup not founds
	checkNoDot(nodep);
	m_cellp = nodep;
	AstNode::user5ClearTree();
	if (!nodep->modp()) {
	    nodep->v3fatalSrc("Cell has unlinked module"); // V3LinkCell should have errored out
	}
	else {
            if (VN_IS(nodep->modp(), NotFoundModule)) {
		// Prevent warnings about missing pin connects
		if (nodep->pinsp()) nodep->pinsp()->unlinkFrBackWithNext()->deleteTree();
		if (nodep->paramsp()) nodep->paramsp()->unlinkFrBackWithNext()->deleteTree();
	    }
	    // Need to pass the module info to this cell, so we can link up the pin names
	    // However can't use m_curSymp as pin connections need to use the instantiator's symbols
	    else {
		m_pinSymp = m_statep->getNodeSym(nodep->modp());
		UINFO(4,"(Backto) Link Cell: "<<nodep<<endl);
		//if (debug()) { nodep->dumpTree(cout,"linkcell:"); }
		//if (debug()) { nodep->modp()->dumpTree(cout,"linkcemd:"); }
                iterateChildren(nodep);
		m_pinSymp = NULL;
	    }
	}
	m_cellp = NULL;
	// Parent module inherits child's publicity
	// This is done bottom up in the LinkBotupVisitor stage
    }
    virtual void visit(AstPin* nodep) {
	// Pin: Link to submodule's port
	checkNoDot(nodep);
        iterateChildren(nodep);
	if (!nodep->modVarp()) {
	    if (!m_pinSymp) nodep->v3fatalSrc("Pin not under cell?");
	    VSymEnt* foundp = m_pinSymp->findIdFlat(nodep->name());
	    const char* whatp = nodep->param() ? "parameter pin" : "pin";
	    if (!foundp) {
                if (nodep->name() == "__paramNumber1" && VN_IS(m_cellp->modp(), Primitive)) {
		    // Primitive parameter is really a delay we can just ignore
		    nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
		    return;
		}
		nodep->v3error(ucfirst(whatp)<<" not found: "<<nodep->prettyName());
	    }
            else if (AstVar* refp = VN_CAST(foundp->nodep(), Var)) {
		if (!refp->isIO() && !refp->isParam() && !refp->isIfaceRef()) {
		    nodep->v3error(ucfirst(whatp)<<" is not an in/out/inout/param/interface: "<<nodep->prettyName());
		} else {
		    nodep->modVarp(refp);
		    markAndCheckPinDup(nodep, refp, whatp);
		}
	    }
            else if (AstParamTypeDType* refp = VN_CAST(foundp->nodep(), ParamTypeDType)) {
		nodep->modPTypep(refp);
		markAndCheckPinDup(nodep, refp, whatp);
	    }
	    else {
		nodep->v3error(ucfirst(whatp)<<" not found: "<<nodep->prettyName());
	    }
	}
	// Early return() above when deleted
    }
    virtual void visit(AstDot* nodep) {
	// Legal under a DOT: AstDot, AstParseRef, AstPackageRef, AstNodeSel
	//    also a DOT can be part of an expression, but only above plus AstFTaskRef are legal children
	// DOT(PACKAGEREF, PARSEREF(text))
	// DOT(DOT(DOT(PARSEREF(text), ...
	if (nodep->user3SetOnce()) return;
	UINFO(8,"     "<<nodep<<endl);
	DotStates lastStates = m_ds;
	bool start = (m_ds.m_dotPos == DP_NONE);  // Save, as m_dotp will be changed
	{
	    if (start) {  // Starting dot sequence
		if (debug()>=9) nodep->dumpTree("-dot-in: ");
		m_ds.init(m_curSymp);  // Start from current point
	    }
	    m_ds.m_dotp = nodep;  // Always, not just at start
	    m_ds.m_dotPos = DP_SCOPE;

	    // m_ds.m_dotText communicates the cell prefix between stages
            if (VN_IS(nodep->lhsp(), PackageRef)) {
		//if (!start) { nodep->lhsp()->v3error("Package reference may not be embedded in dotted reference"); m_ds.m_dotErr=true; }
		m_ds.m_dotPos = DP_PACKAGE;
	    } else {
		m_ds.m_dotPos = DP_SCOPE;
                iterateAndNextNull(nodep->lhsp());
		//if (debug()>=9) nodep->dumpTree("-dot-lho: ");
	    }
            if (m_ds.m_unresolved && (VN_IS(nodep->lhsp(), CellRef) || VN_IS(nodep->lhsp(), CellArrayRef))) {
		m_ds.m_unlinkedScope = nodep->lhsp();
	    }
	    if (!m_ds.m_dotErr) {  // Once something wrong, give up
		if (start && m_ds.m_dotPos==DP_SCOPE) m_ds.m_dotPos = DP_FINAL;  // Top 'final' dot RHS is final RHS, else it's a DOT(DOT(x,*here*),real-rhs) which we consider a RHS
                iterateAndNextNull(nodep->rhsp());
		//if (debug()>=9) nodep->dumpTree("-dot-rho: ");
	    }
	    if (start) {
		AstNode* newp;
		if (m_ds.m_dotErr) {
		    newp = new AstConst(nodep->fileline(),AstConst::LogicFalse());
		} else {
		    // RHS is what we're left with
		    newp = nodep->rhsp()->unlinkFrBack();
		}
		if (debug()>=9) newp->dumpTree("-dot-out: ");
		nodep->replaceWith(newp);
		pushDeletep(nodep); VL_DANGLING(nodep);
	    } else {  // Dot midpoint
		AstNode* newp = nodep->rhsp()->unlinkFrBack();
		if (m_ds.m_unresolved) {
		    AstCellRef* crp = new AstCellRef(nodep->fileline(), nodep->name(), nodep->lhsp()->unlinkFrBack(), newp);
		    newp = crp;
		}
		nodep->replaceWith(newp);
		pushDeletep(nodep); VL_DANGLING(nodep);
	    }
	}
	if (start) {
	    m_ds = lastStates;
	} else {
	    m_ds.m_dotp = lastStates.m_dotp;
	}
    }
    virtual void visit(AstParseRef* nodep) {
	if (nodep->user3SetOnce()) return;
	UINFO(9,"   linkPARSEREF "<<m_ds.ascii()<<"  n="<<nodep<<endl);
	// m_curSymp is symbol table of outer expression
	// m_ds.m_dotSymp is symbol table relative to "."'s above now
	if (!m_ds.m_dotSymp) nodep->v3fatalSrc("NULL lookup symbol table");
	if (!m_statep->forPrimary()) nodep->v3fatalSrc("ParseRefs should no longer exist");
	DotStates lastStates = m_ds;
	bool start = (m_ds.m_dotPos == DP_NONE);  // Save, as m_dotp will be changed
	if (start) {
	    m_ds.init(m_curSymp);
	    // Note m_ds.m_dot remains NULL; this is a reference not under a dot
	}
	if (m_ds.m_dotPos == DP_MEMBER) {
	    // Found a Var, everything following is membership.  {scope}.{var}.HERE {member}
	    AstNode* varEtcp = m_ds.m_dotp->lhsp()->unlinkFrBack();
	    AstNode* newp = new AstMemberSel(nodep->fileline(), varEtcp, VFlagChildDType(), nodep->name());
	    nodep->replaceWith(newp);
	    pushDeletep(nodep); VL_DANGLING(nodep);
	}
	else {
	    //
	    string expectWhat;
	    bool allowScope = false;
	    bool allowVar = false;
	    if (m_ds.m_dotPos == DP_PACKAGE) {
		// {package}::{a}
		AstPackage* packagep = NULL;
		expectWhat = "scope/variable";
		allowScope = true;
		allowVar = true;
                if (!VN_IS(m_ds.m_dotp->lhsp(), PackageRef)) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
                packagep = VN_CAST(m_ds.m_dotp->lhsp(), PackageRef)->packagep();
		if (!packagep) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
		m_ds.m_dotSymp = m_statep->getNodeSym(packagep);
		m_ds.m_dotPos = DP_SCOPE;
	    } else if (m_ds.m_dotPos == DP_SCOPE) {
		// {a}.{b}, where {a} maybe a module name
		// or variable, where dotting into structure member
		expectWhat = "scope/variable";
		allowScope = true;
		allowVar = true;
	    } else if (m_ds.m_dotPos == DP_NONE
		       || m_ds.m_dotPos == DP_FINAL) {
		expectWhat = "variable";
		allowVar = true;
	    } else {
		UINFO(1,"ds="<<m_ds.ascii()<<endl);
		nodep->v3fatalSrc("Unhandled AstParseRefExp");
	    }
	    // Lookup
	    VSymEnt* foundp;
	    string baddot;
	    VSymEnt* okSymp = NULL;
	    if (allowScope) {
		foundp = m_statep->findDotted(m_ds.m_dotSymp, nodep->name(), baddot, okSymp); // Maybe NULL
	    } else {
		foundp = m_ds.m_dotSymp->findIdFallback(nodep->name());
	    }
            if (foundp) UINFO(9,"     found=se"<<cvtToHex(foundp)<<"  exp="<<expectWhat
			      <<"  n="<<foundp->nodep()<<endl);
	    // What fell out?
	    bool ok = false;
	    if (!foundp) {
            } else if (VN_IS(foundp->nodep(), Cell)
                       || VN_IS(foundp->nodep(), Begin)
                       || VN_IS(foundp->nodep(), Module)) {  // if top
		if (allowScope) {
		    ok = true;
                    m_ds.m_dotText = VString::dot(m_ds.m_dotText, ".", nodep->name());
		    m_ds.m_dotSymp = foundp;
		    m_ds.m_dotPos = DP_SCOPE;
		    // Upper AstDot visitor will handle it from here
		}
                else if (VN_IS(foundp->nodep(), Cell)
			 && allowVar && m_cellp) {
                    AstCell* cellp = VN_CAST(foundp->nodep(), Cell);
                    if (VN_IS(cellp->modp(), Iface)) {
                        // Interfaces can be referenced like a variable for interconnect
                        VSymEnt* cellEntp = m_statep->getNodeSym(cellp);
                        if (!cellEntp) nodep->v3fatalSrc("No interface sym entry");
                        VSymEnt* parentEntp = cellEntp->parentp();  // Container of the var; probably a module or generate begin
                        string findName = nodep->name()+"__Viftop";
                        VSymEnt* ifaceSymp = parentEntp->findIdFallback(findName);
                        AstVar* ifaceRefVarp = ifaceSymp ? VN_CAST(ifaceSymp->nodep(), Var) : NULL;
                        if (!ifaceRefVarp) nodep->v3fatalSrc("Can't find interface var ref: "<<findName);
                        //
                        ok = true;
                        m_ds.m_dotText = VString::dot(m_ds.m_dotText, ".", nodep->name());
                        m_ds.m_dotSymp = foundp;
                        m_ds.m_dotPos = DP_SCOPE;
                        UINFO(9," cell -> iface varref "<<foundp->nodep()<<endl);
                        AstNode* newp = new AstVarRef(ifaceRefVarp->fileline(), ifaceRefVarp, false);
                        nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
                    } else if (VN_IS(cellp->modp(), NotFoundModule)) {
			cellp->v3error("Cannot find file containing interface: " << AstNode::prettyName(cellp->modp()->name()));
                    }
                }
	    }
	    else if (AstVar* varp = foundToVarp(foundp, nodep, false)) {
		AstIfaceRefDType* ifacerefp = LinkDotState::ifaceRefFromArray(varp->subDTypep());
		if (ifacerefp) {
		    if (!ifacerefp->ifaceViaCellp()) ifacerefp->v3fatalSrc("Unlinked interface");
		    // Really this is a scope reference into an interface
		    UINFO(9,"varref-ifaceref "<<m_ds.m_dotText<<"  "<<nodep<<endl);
                    m_ds.m_dotText = VString::dot(m_ds.m_dotText, ".", nodep->name());
		    m_ds.m_dotSymp = m_statep->getNodeSym(ifacerefp->ifaceViaCellp());
		    m_ds.m_dotPos = DP_SCOPE;
		    ok = true;
		    AstNode* newp = new AstVarRef(nodep->fileline(), varp, false);
		    nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
		}
		else if (allowVar) {
		    AstNode* newp;
		    if (m_ds.m_dotText != "") {
			AstVarXRef* refp = new AstVarXRef(nodep->fileline(), nodep->name(),
							  m_ds.m_dotText, false);  // lvalue'ness computed later
			refp->varp(varp);
			m_ds.m_dotText = "";
			if (m_ds.m_unresolved && m_ds.m_unlinkedScope) {
                            newp = new AstUnlinkedRef(nodep->fileline(), VN_CAST(refp, VarXRef),
						      refp->name(), m_ds.m_unlinkedScope->unlinkFrBack());
			    m_ds.m_unlinkedScope = NULL;
			    m_ds.m_unresolved = false;
			} else {
			    newp = refp;
			}
		    } else {
			AstVarRef* refp = new AstVarRef(nodep->fileline(), varp, false);  // lvalue'ness computed later
			refp->packagep(foundp->packagep());
			newp = refp;
		    }
		    UINFO(9,"    new "<<newp<<endl);
		    nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
		    m_ds.m_dotPos = DP_MEMBER;
		    ok = true;
		}
	    }
            else if (AstModport* modportp = VN_CAST(foundp->nodep(), Modport)) {
		// A scope reference into an interface's modport (not necessarily at a pin connection)
		UINFO(9,"cell-ref-to-modport "<<m_ds.m_dotText<<"  "<<nodep<<endl);
		UINFO(9,"dotSymp "<<m_ds.m_dotSymp<<" "<<m_ds.m_dotSymp->nodep()<<endl);
		// Iface was the previously dotted component
		if (!m_ds.m_dotSymp
                    || !VN_IS(m_ds.m_dotSymp->nodep(), Cell)
                    || !VN_CAST(m_ds.m_dotSymp->nodep(), Cell)->modp()
                    || !VN_IS(VN_CAST(m_ds.m_dotSymp->nodep(), Cell)->modp(), Iface)) {
		    nodep->v3error("Modport not referenced as <interface>."<<modportp->prettyName());
                } else if (!VN_CAST(m_ds.m_dotSymp->nodep(), Cell)->modp()
                           || !VN_IS(VN_CAST(m_ds.m_dotSymp->nodep(), Cell)->modp(), Iface)) {
		    nodep->v3error("Modport not referenced from underneath an interface: "<<modportp->prettyName());
		} else {
                    AstCell* cellp = VN_CAST(m_ds.m_dotSymp->nodep(), Cell);
		    if (!cellp) nodep->v3fatalSrc("Modport not referenced from a cell");
                    AstIface* ifacep = VN_CAST(cellp->modp(), Iface);
		    //string cellName = m_ds.m_dotText;   // Use cellp->name
                    m_ds.m_dotText = VString::dot(m_ds.m_dotText, ".", nodep->name());
		    m_ds.m_dotSymp = m_statep->getNodeSym(modportp);
		    m_ds.m_dotPos = DP_SCOPE;
		    ok = true;
		    AstVar* varp = makeIfaceModportVar(nodep->fileline(), cellp, ifacep, modportp);
		    AstVarRef* refp = new AstVarRef(varp->fileline(), varp, false);
		    nodep->replaceWith(refp); pushDeletep(nodep); VL_DANGLING(nodep);
		}
	    }
            else if (AstEnumItem* valuep = VN_CAST(foundp->nodep(), EnumItem)) {
		if (allowVar) {
		    AstNode* newp = new AstEnumItemRef(nodep->fileline(), valuep, foundp->packagep());
		    nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
		    ok = true;
		    m_ds.m_dotText = "";
		}
	    }
	    //
	    if (!ok) {
                // Cells/interfaces can't be implicit
                bool isCell = foundp ? VN_IS(foundp->nodep(), Cell) : false;
		bool checkImplicit = (!m_ds.m_dotp && m_ds.m_dotText=="" && !isCell);
		bool err = !(checkImplicit && m_statep->implicitOk(m_modp, nodep->name()));
		if (err) {
		    if (foundp) {
			nodep->v3error("Found definition of '"<<m_ds.m_dotText<<(m_ds.m_dotText==""?"":".")<<nodep->prettyName()
				       <<"'"<<" as a "<<foundp->nodep()->typeName()
				       <<" but expected a "<<expectWhat);
		    } else if (m_ds.m_dotText=="") {
                        UINFO(7,"   ErrParseRef curSymp=se"<<cvtToHex(m_curSymp)<<" ds="<<m_ds.ascii()<<endl);
			nodep->v3error("Can't find definition of "<<expectWhat
				       <<": "<<nodep->prettyName());
		    } else {
			nodep->v3error("Can't find definition of '"<<(baddot!=""?baddot:nodep->prettyName())<<"' in dotted "
				       <<expectWhat<<": "<<m_ds.m_dotText+"."+nodep->prettyName());
			okSymp->cellErrorScopes(nodep, AstNode::prettyName(m_ds.m_dotText));
		    }
		    m_ds.m_dotErr = true;
		}
		if (checkImplicit) {  // Else if a scope is allowed, making a signal won't help error cascade
		    // Create if implicit, and also if error (so only complain once)
		    AstVarRef* newp = new AstVarRef(nodep->fileline(), nodep->name(), false);
		    nodep->replaceWith(newp);
		    pushDeletep(nodep); VL_DANGLING(nodep);
                    createImplicitVar(m_curSymp, newp, m_modp, m_modSymp, err);
		}
	    }
	}
	if (start) {
	    m_ds = lastStates;
	}
    }
    virtual void visit(AstVarRef* nodep) {
	// VarRef: Resolve its reference
	// ParseRefs are used the first pass (forPrimary) so we shouldn't get can't find
	// errors here now that we have a VarRef.
	// No checkNoDot; created and iterated from a parseRef
        iterateChildren(nodep);
	if (!nodep->varp()) {
            UINFO(9," linkVarRef se"<<cvtToHex(m_curSymp)<<"  n="<<nodep<<endl);
	    if (!m_curSymp) nodep->v3fatalSrc("NULL lookup symbol table");
	    VSymEnt* foundp = m_curSymp->findIdFallback(nodep->name());
	    if (AstVar* varp = foundp ? foundToVarp(foundp, nodep, nodep->lvalue()) : NULL) {
		nodep->varp(varp);
		nodep->packagep(foundp->packagep());  // Generally set by parse, but might be an import
	    }
	    if (!nodep->varp()) {
		nodep->v3error("Can't find definition of signal, again: "<<nodep->prettyName());
	    }
	}
    }
    virtual void visit(AstVarXRef* nodep) {
	// VarRef: Resolve its reference
	// We always link even if varp() is set, because the module we choose may change
	// due to creating new modules, flattening, etc.
	if (nodep->user3SetOnce()) return;
	UINFO(8,"     "<<nodep<<endl);
	// No checkNoDot; created and iterated from a parseRef
	if (!m_modSymp) {
	    UINFO(9,"Dead module for "<<nodep<<endl);
	    nodep->varp(NULL);  // Module that is not in hierarchy.  We'll be dead code eliminating it later.
	} else {
	    string baddot;
	    VSymEnt* okSymp;
	    VSymEnt* dotSymp = m_curSymp;  // Start search at current scope
	    if (nodep->inlinedDots()!="") {  // Correct for current scope
		dotSymp = m_modSymp; // Dotted lookup is always relative to module, as maybe variable name lower down with same scope name we want to ignore (t_math_divw)
		string inl = AstNode::dedotName(nodep->inlinedDots());
		dotSymp = m_statep->findDotted(dotSymp, inl, baddot, okSymp);
		if (!dotSymp) {
		    nodep->v3fatalSrc("Couldn't resolve inlined scope '"<<baddot<<"' in: "<<nodep->inlinedDots());
		}
	    }
	    dotSymp = m_statep->findDotted(dotSymp, nodep->dotted(), baddot, okSymp); // Maybe NULL
	    if (!m_statep->forScopeCreation()) {
		VSymEnt* foundp = m_statep->findSymPrefixed(dotSymp, nodep->name(), baddot);
		AstVar* varp = foundp ? foundToVarp(foundp, nodep, nodep->lvalue()) : NULL;
		nodep->varp(varp);
		UINFO(7,"         Resolved "<<nodep<<endl);  // Also prints varp
		if (!nodep->varp()) {
		    nodep->v3error("Can't find definition of '"<<baddot<<"' in dotted signal: "<<nodep->dotted()+"."+nodep->prettyName());
		    okSymp->cellErrorScopes(nodep);
		}
		// V3Inst may have expanded arrays of interfaces to AstVarXRef's even though they are in the same module
		// detect this and convert to normal VarRefs
		if (!m_statep->forPrearray() && !m_statep->forScopeCreation()) {
                    if (VN_IS(nodep->dtypep(), IfaceRefDType)) {
			AstVarRef* newrefp = new AstVarRef(nodep->fileline(), nodep->varp(), nodep->lvalue());
			nodep->replaceWith(newrefp);
			nodep->deleteTree(); VL_DANGLING(nodep);
		    }
		}
	    } else {
		string baddot;
		VSymEnt* foundp = m_statep->findSymPrefixed(dotSymp, nodep->name(), baddot);
                AstVarScope* vscp = foundp ? VN_CAST(foundp->nodep(), VarScope) : NULL;
		if (!vscp) {
                    nodep->v3error("Can't find varpin scope of '"<<baddot
                                   <<"' in dotted signal: "<<nodep->dotted()+"."+nodep->prettyName());
		    okSymp->cellErrorScopes(nodep);
		} else {
		    while (vscp->user2p()) {  // If V3Inline aliased it, pick up the new signal
			UINFO(7,"         Resolved pre-alias "<<vscp<<endl);  // Also prints taskp
                        vscp = VN_CAST(vscp->user2p(), VarScope);
		    }
		    // Convert the VarXRef to a VarRef, so we don't need later optimizations to deal with VarXRef.
		    nodep->varp(vscp->varp());
		    nodep->varScopep(vscp);
		    UINFO(7,"         Resolved "<<nodep<<endl);  // Also prints taskp
		    AstVarRef* newvscp = new AstVarRef(nodep->fileline(), vscp, nodep->lvalue());
		    nodep->replaceWith(newvscp);
		    nodep->deleteTree(); VL_DANGLING(nodep);
		    UINFO(9,"         new "<<newvscp<<endl);  // Also prints taskp
		}
	    }
	}
    }
    virtual void visit(AstEnumItemRef* nodep) {
	// EnumItemRef may be under a dot.  Should already be resolved.
        iterateChildren(nodep);
    }
    virtual void visit(AstMethodSel* nodep) {
	// Created here so should already be resolved.
	DotStates lastStates = m_ds;
	{
	    m_ds.init(m_curSymp);
            iterateChildren(nodep);
	}
	m_ds = lastStates;
    }
    virtual void visit(AstVar* nodep) {
	checkNoDot(nodep);
        iterateChildren(nodep);
	if (m_statep->forPrimary() && nodep->isIO() && !m_ftaskp && !nodep->user4()) {
	    nodep->v3error("Input/output/inout does not appear in port list: "<<nodep->prettyName());
	}
    }
    virtual void visit(AstNodeFTaskRef* nodep) {
	if (nodep->user3SetOnce()) return;
	UINFO(8,"     "<<nodep<<endl);
	if (m_ds.m_dotp && m_ds.m_dotPos == DP_PACKAGE) {
            if (!VN_IS(m_ds.m_dotp->lhsp(), PackageRef)) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
            if (!VN_CAST(m_ds.m_dotp->lhsp(), PackageRef)->packagep()) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
            nodep->packagep(VN_CAST(m_ds.m_dotp->lhsp(), PackageRef)->packagep());
	    m_ds.m_dotPos = DP_SCOPE;
	    m_ds.m_dotp = NULL;
	} else if (m_ds.m_dotp && m_ds.m_dotPos == DP_FINAL) {
	    if (m_ds.m_unresolved && m_ds.m_unlinkedScope) {
		AstNodeFTaskRef* newftaskp = nodep->cloneTree(false);
		newftaskp->dotted(m_ds.m_dotText);
		AstNode* newp = new AstUnlinkedRef(nodep->fileline(), newftaskp, nodep->name(), m_ds.m_unlinkedScope->unlinkFrBack());
		m_ds.m_unlinkedScope = NULL;
		m_ds.m_unresolved = false;
		nodep->replaceWith(newp);
		return;
	    } else {
		nodep->dotted(m_ds.m_dotText);  // Maybe ""
	    }
	} else if (m_ds.m_dotp && m_ds.m_dotPos == DP_MEMBER) {
	    // Found a Var, everything following is method call.  {scope}.{var}.HERE {method} ( ARGS )
	    AstNode* varEtcp = m_ds.m_dotp->lhsp()->unlinkFrBack();
	    AstNode* argsp = NULL; if (nodep->pinsp()) argsp = nodep->pinsp()->unlinkFrBackWithNext();
	    AstNode* newp = new AstMethodSel(nodep->fileline(), varEtcp, VFlagChildDType(), nodep->name(), argsp);
	    nodep->replaceWith(newp);
	    pushDeletep(nodep); VL_DANGLING(nodep);
	    return;
	} else {
	    checkNoDot(nodep);
	}
	if (nodep->packagep() && nodep->taskp()) {
	    // References into packages don't care about cell hierarchy.
	} else if (!m_modSymp) {
	    UINFO(9,"Dead module for "<<nodep<<endl);
	    nodep->taskp(NULL);  // Module that is not in hierarchy.  We'll be dead code eliminating it later.
	} else if (nodep->dotted()=="" && nodep->taskp()) {
	    // Earlier should have setup the links
	    // Might be under a BEGIN we're not processing, so don't relink it
	} else {
	    string baddot;
	    VSymEnt* okSymp = NULL;
	    VSymEnt* dotSymp = m_curSymp;  // Start search at module, as a variable of same name under a subtask isn't a relevant hit
	    //				   // however a function under a begin/end is.  So we want begins, but not the function
	    if (nodep->packagep()) {	// Look only in specified package
		dotSymp = m_statep->getNodeSym(nodep->packagep());
	    } else {
		if (nodep->inlinedDots()!="") {  // Correct for current scope
		    dotSymp = m_modSymp; // Dotted lookup is always relative to module, as maybe variable name lower down with same scope name we want to ignore (t_math_divw)
		    string inl = AstNode::dedotName(nodep->inlinedDots());
		    UINFO(8,"\t\tInlined "<<inl<<endl);
		    dotSymp = m_statep->findDotted(dotSymp, inl, baddot, okSymp);
		    if (!dotSymp) {
			okSymp->cellErrorScopes(nodep);
			nodep->v3fatalSrc("Couldn't resolve inlined scope '"<<baddot<<"' in: "<<nodep->inlinedDots());
		    }
		}
		dotSymp = m_statep->findDotted(dotSymp, nodep->dotted(), baddot, okSymp); // Maybe NULL
	    }
            VSymEnt* foundp = m_statep->findSymPrefixed(dotSymp, nodep->name(), baddot);
            AstNodeFTask* taskp = foundp ? VN_CAST(foundp->nodep(), NodeFTask) : NULL;  // Maybe NULL
	    if (taskp) {
		nodep->taskp(taskp);
		nodep->packagep(foundp->packagep());
		UINFO(7,"         Resolved "<<nodep<<endl);  // Also prints taskp
	    } else {
		// Note ParseRef has similar error handling/message output
                UINFO(7,"   ErrFtask curSymp=se"<<cvtToHex(m_curSymp)
                      <<" dotSymp=se"<<cvtToHex(dotSymp)<<endl);
		if (foundp) {
		    nodep->v3error("Found definition of '"<<m_ds.m_dotText<<(m_ds.m_dotText==""?"":".")<<nodep->prettyName()
				   <<"'"<<" as a "<<foundp->nodep()->typeName()
				   <<" but expected a task/function");
		} else if (nodep->dotted() == "") {
		    nodep->v3error("Can't find definition of task/function: "<<nodep->prettyName());
		} else {
                    nodep->v3error("Can't find definition of '"<<baddot
                                   <<"' in dotted task/function: "<<nodep->dotted()+"."+nodep->prettyName());
		    okSymp->cellErrorScopes(nodep);
		}
	    }
	    taskFuncSwapCheck(nodep);
	}
	DotStates lastStates = m_ds;
	{
	    m_ds.init(m_curSymp);
            iterateChildren(nodep);
	}
	m_ds = lastStates;
    }
    virtual void visit(AstSelBit* nodep) {
	if (nodep->user3SetOnce()) return;
        iterateAndNextNull(nodep->lhsp());
	if (m_ds.m_dotPos == DP_SCOPE) { // Already under dot, so this is {modulepart} DOT {modulepart}
	    UINFO(9,"  deferring until after a V3Param pass: "<<nodep<<endl);
	    m_ds.m_dotText += "__BRA__??__KET__";
	    m_ds.m_unresolved = true;
	    // And pass up m_ds.m_dotText
	}
	// Pass dot state down to fromp()
        iterateAndNextNull(nodep->fromp());
	DotStates lastStates = m_ds;
	{
	    m_ds.init(m_curSymp);
            iterateAndNextNull(nodep->bitp());
            iterateAndNextNull(nodep->attrp());
	}
	m_ds = lastStates;
	if (m_ds.m_unresolved && m_ds.m_dotPos == DP_SCOPE) {
	    AstNode* exprp = nodep->bitp()->unlinkFrBack();
	    AstCellArrayRef* newp = new AstCellArrayRef(nodep->fileline(), nodep->fromp()->name(), exprp);
	    nodep->replaceWith(newp); pushDeletep(nodep); VL_DANGLING(nodep);
	}
    }
    virtual void visit(AstNodePreSel* nodep) {
	// Excludes simple AstSelBit, see above
	if (nodep->user3SetOnce()) return;
	if (m_ds.m_dotPos == DP_SCOPE) { // Already under dot, so this is {modulepart} DOT {modulepart}
	    nodep->v3error("Syntax Error: Range ':', '+:' etc are not allowed in the cell part of a dotted reference");
	    m_ds.m_dotErr = true;
	    return;
	}
        iterateAndNextNull(nodep->lhsp());
	DotStates lastStates = m_ds;
	{
	    m_ds.init(m_curSymp);
            iterateAndNextNull(nodep->rhsp());
            iterateAndNextNull(nodep->thsp());
            iterateAndNextNull(nodep->attrp());
	}
	m_ds = lastStates;
    }
    virtual void visit(AstMemberSel* nodep) {
	// checkNoDot not appropriate, can be under a dot
        iterateChildren(nodep);
    }
    virtual void visit(AstBegin* nodep) {
	UINFO(5,"   "<<nodep<<endl);
	checkNoDot(nodep);
	VSymEnt* oldCurSymp = m_curSymp;
	{
	    m_ds.m_dotSymp = m_curSymp = m_statep->getNodeSym(nodep);
            UINFO(5,"   cur=se"<<cvtToHex(m_curSymp)<<endl);
            iterateChildren(nodep);
	}
	m_ds.m_dotSymp = m_curSymp = oldCurSymp;
        UINFO(5,"   cur=se"<<cvtToHex(m_curSymp)<<endl);
    }
    virtual void visit(AstNodeFTask* nodep) {
	UINFO(5,"   "<<nodep<<endl);
	checkNoDot(nodep);
	VSymEnt* oldCurSymp = m_curSymp;
	{
	    m_ftaskp = nodep;
	    m_ds.m_dotSymp = m_curSymp = m_statep->getNodeSym(nodep);
            iterateChildren(nodep);
	}
	m_ds.m_dotSymp = m_curSymp = oldCurSymp;
	m_ftaskp = NULL;
    }
    virtual void visit(AstRefDType* nodep) {
	// Resolve its reference
	if (nodep->user3SetOnce()) return;
	if (m_ds.m_dotp && m_ds.m_dotPos == DP_PACKAGE) {
            if (!VN_IS(m_ds.m_dotp->lhsp(), PackageRef)) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
            if (!VN_CAST(m_ds.m_dotp->lhsp(), PackageRef)->packagep()) m_ds.m_dotp->lhsp()->v3fatalSrc("Bad package link");
            nodep->packagep(VN_CAST(m_ds.m_dotp->lhsp(), PackageRef)->packagep());
	    m_ds.m_dotPos = DP_SCOPE;
	    m_ds.m_dotp = NULL;
	} else {
	    checkNoDot(nodep);
	}
	if (!nodep->defp()) {
	    VSymEnt* foundp;
	    if (nodep->packagep()) {
		foundp = m_statep->getNodeSym(nodep->packagep())->findIdFlat(nodep->name());
	    } else {
		foundp = m_curSymp->findIdFallback(nodep->name());
	    }
            if (AstTypedef* defp = foundp ? VN_CAST(foundp->nodep(), Typedef) : NULL) {
		nodep->refDTypep(defp->subDTypep());
		nodep->packagep(foundp->packagep());
	    }
            else if (AstParamTypeDType* defp = foundp ? VN_CAST(foundp->nodep(), ParamTypeDType) : NULL) {
		nodep->refDTypep(defp);
		nodep->packagep(foundp->packagep());
	    }
	    else {
		nodep->v3error("Can't find typedef: "<<nodep->prettyName());
	    }
	}
        iterateChildren(nodep);
    }
    virtual void visit(AstDpiExport* nodep) {
	// AstDpiExport: Make sure the function referenced exists, then dump it
        iterateChildren(nodep);
	checkNoDot(nodep);
	VSymEnt* foundp = m_curSymp->findIdFallback(nodep->name());
        AstNodeFTask* taskp = foundp ? VN_CAST(foundp->nodep(), NodeFTask) : NULL;
	if (!taskp) { nodep->v3error("Can't find definition of exported task/function: "<<nodep->prettyName()); }
	else if (taskp->dpiExport()) {
	    nodep->v3error("Function was already DPI Exported, duplicate not allowed: "<<nodep->prettyName());
	} else {
	    taskp->dpiExport(true);
	    if (nodep->cname()!="") taskp->cname(nodep->cname());
	}
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstPackageImport* nodep) {
	// No longer needed
	checkNoDot(nodep);
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstPackageExport* nodep) {
	// No longer needed
	checkNoDot(nodep);
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstPackageExportStarStar* nodep) {
	// No longer needed
	checkNoDot(nodep);
	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
    }
    virtual void visit(AstCellRef* nodep) {
	UINFO(5,"  AstCellRef: "<<nodep<<" "<<m_ds.ascii()<<endl);
        iterateChildren(nodep);
    }
    virtual void visit(AstCellArrayRef* nodep) {
	UINFO(5,"  AstCellArrayRef: "<<nodep<<" "<<m_ds.ascii()<<endl);
	// Expression already iterated
    }
    virtual void visit(AstUnlinkedRef* nodep) {
	UINFO(5,"  AstCellArrayRef: "<<nodep<<" "<<m_ds.ascii()<<endl);
	// No need to iterate, if we have a UnlinkedVarXRef, we're already done
    }

    virtual void visit(AstNode* nodep) {
	// Default: Just iterate
	checkNoDot(nodep);
        iterateChildren(nodep);
    }
public:
    // CONSTUCTORS
    LinkDotResolveVisitor(AstNetlist* rootp, LinkDotState* statep) {
	UINFO(4,__FUNCTION__<<": "<<endl);
	m_statep = statep;
	m_modSymp = NULL;
	m_curSymp = NULL;
	m_pinSymp = NULL;
	m_cellp = NULL;
	m_modp = NULL;
	m_ftaskp = NULL;
	m_modportNum = 0;
	//
        iterate(rootp);
    }
    virtual ~LinkDotResolveVisitor() {}
};

//######################################################################
// Link class functions

int V3LinkDot::debug() { return LinkDotState::debug(); }

void V3LinkDot::linkDotGuts(AstNetlist* rootp, VLinkDotStep step) {
    if (LinkDotState::debug()>=5 || v3Global.opt.dumpTree()>=9) {
        v3Global.rootp()->dumpTreeFile(v3Global.debugFilename("prelinkdot.tree"));
    }
    LinkDotState state (rootp, step);
    LinkDotFindVisitor visitor(rootp,&state);
    if (LinkDotState::debug()>=5 || v3Global.opt.dumpTree()>=9) {
        v3Global.rootp()->dumpTreeFile(v3Global.debugFilename("prelinkdot-find.tree"));
    }
    if (step == LDS_PRIMARY || step == LDS_PARAMED) {
	// Initial link stage, resolve parameters
	LinkDotParamVisitor visitors(rootp,&state);
        if (LinkDotState::debug()>=5 || v3Global.opt.dumpTree()>=9) {
            v3Global.rootp()->dumpTreeFile(v3Global.debugFilename("prelinkdot-param.tree"));
        }
    }
    else if (step == LDS_ARRAYED) {}
    else if (step == LDS_SCOPED) {
	// Well after the initial link when we're ready to operate on the flat design,
	// process AstScope's.  This needs to be separate pass after whole hierarchy graph created.
	LinkDotScopeVisitor visitors(rootp,&state);
        if (LinkDotState::debug()>=5 || v3Global.opt.dumpTree()>=9) {
            v3Global.rootp()->dumpTreeFile(v3Global.debugFilename("prelinkdot-scoped.tree"));
        }
    }
    else v3fatalSrc("Bad case");
    state.dump();
    state.computeIfaceModSyms();
    state.computeIfaceVarSyms();
    state.computeScopeAliases();
    state.dump();
    LinkDotResolveVisitor visitorb(rootp,&state);
}