Internals: Fix compares to null, part of bug1030. No functional change intended.

src/V3LinkCells.cpp

@@ -122,8 +122,14 @@ private:
 	return (nodep->user1p()->castGraphVertex());
     }
 
+    AstNodeModule* findModuleSym(const string& modName) {
+	VSymEnt* foundp = m_mods.rootp()->findIdFallback(modName);
+	if (!foundp) return NULL;
+	else return foundp->nodep()->castNodeModule();
+    }
+
     AstNodeModule* resolveModule(AstNode* nodep, const string& modName) {
-	AstNodeModule* modp = m_mods.rootp()->findIdFallback(modName)->nodep()->castNodeModule();
+	AstNodeModule* modp = findModuleSym(modName);
 	if (!modp) {
 	    // Read-subfile
 	    // If file not found, make AstNotFoundModule, rather than error out.
@@ -135,7 +141,7 @@ private:
 	    // We've read new modules, grab new pointers to their names
 	    readModNames();
 	    // Check again
-	    modp = m_mods.rootp()->findIdFallback(modName)->nodep()->castNodeModule();
+	    modp = findModuleSym(modName);
 	    if (!modp) {
 		// This shouldn't throw a message as parseFile will create a AstNotFoundModule for us
 		nodep->v3error("Can't resolve module reference: "<<prettyName);
@@ -387,7 +393,7 @@ private:
 	// Look at all modules, and store pointers to all module names
 	for (AstNodeModule* nextp,* nodep = v3Global.rootp()->modulesp(); nodep; nodep=nextp) {
 	    nextp = nodep->nextp()->castNodeModule();
-	    AstNode* foundp = m_mods.rootp()->findIdFallback(nodep->name())->nodep();
+	    AstNodeModule* foundp = findModuleSym(nodep->name());
 	    if (foundp && foundp != nodep) {
 		if (!(foundp->fileline()->warnIsOff(V3ErrorCode::MODDUP) || nodep->fileline()->warnIsOff(V3ErrorCode::MODDUP))) {
 		    nodep->v3warn(MODDUP,"Duplicate declaration of module: "<<nodep->prettyName()<<endl

src/V3LinkDot.cpp

@@ -207,7 +207,7 @@ public:
 	// 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->nodep();
+	AstNode* fnodep = foundp ? foundp->nodep() : NULL;
 	if (!fnodep) {
 	    // Not found, will add in a moment.
 	} else if (nodep==fnodep) {  // Already inserted.
@@ -378,7 +378,7 @@ public:
     void computeIfaceVarSyms() {
 	for (IfaceVarSyms::iterator it = m_ifaceVarSyms.begin(); it != m_ifaceVarSyms.end(); ++it) {
 	    VSymEnt* varSymp = *it;
-	    AstVar* varp = varSymp->nodep()->castVar();
+	    AstVar* varp = varSymp ? varSymp->nodep()->castVar() : NULL;
 	    UINFO(9, "  insAllIface se"<<(void*)varSymp<<" "<<varp<<endl);
 	    AstIfaceRefDType* ifacerefp = ifaceRefFromArray(varp->subDTypep());
 	    if (!ifacerefp) varp->v3fatalSrc("Non-ifacerefs on list!");
@@ -489,8 +489,8 @@ public:
 	    // then look up (inst name or modname)
 	    if (firstId) {
 		// Check this module - subcellnames
-		AstCell* cellp = lookupSymp->nodep()->castCell();  // Replicated below
+		AstCell* cellp = lookupSymp ? lookupSymp->nodep()->castCell() : NULL;  // Replicated below
-		AstCellInline* inlinep = lookupSymp->nodep()->castCellInline(); // Replicated below
+		AstCellInline* inlinep = lookupSymp ? lookupSymp->nodep()->castCellInline() : NULL; // Replicated below
 		if (VSymEnt* findSymp = findWithAltFallback(lookupSymp, ident, altIdent)) {
 		    lookupSymp = findSymp;
 		}
@@ -501,8 +501,8 @@ public:
 		else {
 		    while (lookupSymp) {
 			lookupSymp = lookupSymp->parentp();
-			cellp = lookupSymp->nodep()->castCell(); // Replicated above
+			cellp   = lookupSymp ? lookupSymp->nodep()->castCell() : NULL; // Replicated above
-			inlinep = lookupSymp->nodep()->castCellInline(); // Replicated above
+			inlinep = lookupSymp ? lookupSymp->nodep()->castCellInline() : NULL; // Replicated above
 			if (lookupSymp) {
 			    UINFO(9,"\t\tUp to "<<lookupSymp<<endl);
 			    if ((cellp && cellp->modp()->origName() == ident)
@@ -1033,7 +1033,7 @@ private:
 	nodep->iterateChildren(*this);
 	nodep->v3warn(DEFPARAM,"Suggest replace defparam with Verilog 2001 #(."<<nodep->prettyName()<<"(...etc...))");
 	VSymEnt* foundp = m_statep->getNodeSym(nodep)->findIdFallback(nodep->path());
-	AstCell* cellp = foundp->nodep()->castCell();
+	AstCell* cellp = foundp ? foundp->nodep()->castCell() : NULL;
 	if (!cellp) {
 	    nodep->v3error("In defparam, cell "<<nodep->path()<<" never declared");
 	} else {
@@ -1055,7 +1055,7 @@ private:
 	// 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->nodep()->castVar();
+	AstVar* refp = foundp ? foundp->nodep()->castVar() : NULL;
 	if (!refp) {
 	    nodep->v3error("Input/output/inout declaration not found for port: "<<nodep->prettyName());
 	} else if (!refp->isIO() && !refp->isIfaceRef()) {
@@ -1513,7 +1513,7 @@ private:
 	if (!nodep->modVarp()) {
 	    if (!m_pinSymp) nodep->v3fatalSrc("Pin not under cell?\n");
 	    VSymEnt* foundp = m_pinSymp->findIdFlat(nodep->name());
-	    AstVar* refp = foundp->nodep()->castVar();
+	    AstVar* refp = foundp ? foundp->nodep()->castVar() : NULL;
 	    const char* whatp = nodep->param() ? "parameter pin" : "pin";
 	    if (!refp) {
 		if (nodep->name() == "__paramNumber1" && m_cellp->modp()->castPrimitive()) {
@@ -1661,8 +1661,10 @@ private:
 			      <<"  n="<<foundp->nodep()<<endl);
 	    // What fell out?
 	    bool ok = false;
-	    if (foundp->nodep()->castCell() || foundp->nodep()->castBegin()
+	    if (!foundp) {
-		|| foundp->nodep()->castModule()) {  // if top
+	    } else if (foundp->nodep()->castCell()
+		       || foundp->nodep()->castBegin()
+		       || foundp->nodep()->castModule()) {  // if top
 		if (allowScope) {
 		    ok = true;
 		    if (m_ds.m_dotText!="") m_ds.m_dotText += ".";
@@ -1679,7 +1681,8 @@ private:
 		    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";
-		    AstVar* ifaceRefVarp = parentEntp->findIdFallback(findName)->nodep()->castVar();
+		    VSymEnt* ifaceSymp = parentEntp->findIdFallback(findName);
+		    AstVar* ifaceRefVarp = ifaceSymp ? ifaceSymp->nodep()->castVar() : NULL;
 		    if (!ifaceRefVarp) nodep->v3fatalSrc("Can't find interface var ref: "<<findName);
 		    //
 		    ok = true;
@@ -1811,7 +1814,7 @@ private:
 	    UINFO(9," linkVarRef se"<<(void*)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->nodep()->castVar()) {
+	    if (AstVar* varp = foundp ? foundp->nodep()->castVar() : NULL) {
 		nodep->varp(varp);
 		nodep->packagep(foundp->packagep());  // Generally set by parse, but might be an import
 	    }
@@ -1845,7 +1848,7 @@ private:
 	    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->nodep()->castVar();  // maybe NULL
+		AstVar* varp = foundp ? foundp->nodep()->castVar() : NULL;
 		nodep->varp(varp);
 		UINFO(7,"         Resolved "<<nodep<<endl);  // Also prints varp
 		if (!nodep->varp()) {
@@ -1864,7 +1867,7 @@ private:
 	    } else {
 		string baddot;
 		VSymEnt* foundp = m_statep->findSymPrefixed(dotSymp, nodep->name(), baddot);
-		AstVarScope* vscp = foundp->nodep()->castVarScope();  // maybe NULL
+		AstVarScope* vscp = foundp ? foundp->nodep()->castVarScope() : NULL;
 		if (!vscp) {
 		    nodep->v3error("Can't find varpin scope of '"<<baddot<<"' in dotted signal: "<<nodep->dotted()+"."+nodep->prettyName());
 		    okSymp->cellErrorScopes(nodep);
@@ -2085,7 +2088,7 @@ private:
 	    } else {
 		foundp = m_curSymp->findIdFallback(nodep->name());
 	    }
-	    if (AstTypedef* defp = foundp->nodep()->castTypedef()) {
+	    if (AstTypedef* defp = foundp ? foundp->nodep()->castTypedef() : NULL) {
 		nodep->refDTypep(defp->subDTypep());
 		nodep->packagep(foundp->packagep());
 	    } else {
@@ -2099,7 +2102,7 @@ private:
 	nodep->iterateChildren(*this);
 	checkNoDot(nodep);
 	VSymEnt* foundp = m_curSymp->findIdFallback(nodep->name());
-	AstNodeFTask* taskp = foundp->nodep()->castNodeFTask();
+	AstNodeFTask* taskp = foundp ? foundp->nodep()->castNodeFTask() : 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());

src/V3ParseSym.h

@@ -118,7 +118,9 @@ public:
     }
     AstNode* findEntUpward (const string& name) {
 	// Lookup the given string as an identifier, return type of the id, scanning upward
-	return symCurrentp()->findIdFallback(name)->nodep();
+	VSymEnt* foundp = symCurrentp()->findIdFallback(name);
+	if (foundp) return foundp->nodep();
+	else return NULL;
     }
     void import(AstNode* packagep, const string& id_or_star) {
 	// Import from package::id_or_star to this

src/V3SymTable.h

@@ -107,7 +107,7 @@ public:
     VSymEnt* parentp() const { return m_parentp; }
     void packagep(AstPackage* entp) { m_packagep = entp; }
     AstPackage* packagep() const { return m_packagep; }
-    AstNode* nodep() const { if (!this) return NULL; else return m_nodep; }  // null check so can call .findId(...)->nodep()
+    AstNode* nodep() const { return m_nodep; }
     string symPrefix() const { return m_symPrefix; }
     void symPrefix(const string& name) { m_symPrefix = name; }
     bool exported() const { return m_exported; }
@@ -284,7 +284,7 @@ inline VSymEnt::VSymEnt(VSymGraph* graphp, AstNode* nodep)
 }
 
 inline VSymEnt::VSymEnt(VSymGraph* graphp, const VSymEnt* symp)
-    : m_nodep(symp->nodep()) {
+    : m_nodep(symp->m_nodep) {
     m_fallbackp = symp->m_fallbackp;
     m_parentp  = symp->m_parentp;
     m_packagep = symp->m_packagep;

src/V3Width.cpp

@@ -137,9 +137,7 @@ public:
     bool prelim() const { return m_stage & PRELIM; }
     bool final() const { return m_stage & FINAL; }
     void dump(ostream& str) const {
-	if (!this) {
+	if (!m_dtypep) {
-	    str<<"  VUP(NULL)";
-	} else if (!m_dtypep) {
 	    str<<"  VUP(s="<<m_stage<<",self)";
 	} else {
 	    str<<"  VUP(s="<<m_stage<<",dt="<<(void*)dtypep()<<")";
@@ -147,7 +145,7 @@ public:
     }
 };
 ostream& operator<<(ostream& str, const WidthVP* vup) {
-    vup->dump(str);
+    if (vup) vup->dump(str);
     return str;
 }
 

src/verilog.l

@@ -1030,19 +1030,20 @@ int V3ParseImp::lexToken() {
     // If an id, change the type based on symbol table
     // Note above sometimes converts yGLOBAL to a yaID__LEX
     if (token == yaID__LEX) {
-	AstNode* scp;
+	VSymEnt* foundp;
 	if (VSymEnt* look_underp = SYMP->nextId()) {
 	    if (debugFlex()) { cout<<"   lexToken: next id lookup forced under "<<look_underp<<endl; }
-	    scp = look_underp->findIdFallback(*(yylval.strp))->nodep();
+	    foundp = look_underp->findIdFallback(*(yylval.strp));
 	    // "consume" it.  Must set again if want another token under temp scope
 	    SYMP->nextId(NULL);
 	} else {
 	    UINFO(7,"   lexToken: find upward "<<SYMP->symCurrentp()<<" for '"<<*(yylval.strp)<<"'"<<endl);
 	    //if (debug()>=9) SYMP->symCurrentp()->dump(cout,"     -findtree: ",true);
-	    scp = SYMP->symCurrentp()->findIdFallback(*(yylval.strp))->nodep();
+	    foundp = SYMP->symCurrentp()->findIdFallback(*(yylval.strp));
 	}
-	yylval.scp = scp;
+	if (foundp) {
-	if (scp) {
+	    AstNode* scp = foundp->nodep();
+	    yylval.scp = scp;
 	    UINFO(7,"   lexToken: Found "<<scp<<endl);
 	    if (scp->castTypedef())		token = yaID__aTYPE;
 	    else if (scp->castTypedefFwd())	token = yaID__aTYPE;
@@ -1051,6 +1052,7 @@ int V3ParseImp::lexToken() {
 	    //UNSUP else if (scp->castCoverGroup()) 	token = yaID__aCOVERGROUP;
 	    else token = yaID__ETC;
 	} else {  // Not found
+	    yylval.scp = NULL;
 	    token = yaID__ETC;
 	}
     }

src/verilog.y

@@ -121,10 +121,13 @@ public:
     }
     AstPackage* unitPackage(FileLine* fl) {
 	// Find one made earlier?
-	AstPackage* pkgp = SYMP->symRootp()->findIdFlat(AstPackage::dollarUnitName())->nodep()->castPackage();
+	VSymEnt* symp = SYMP->symRootp()->findIdFlat(AstPackage::dollarUnitName());
-	if (!pkgp) {
+	AstPackage* pkgp;
+	if (!symp) {
 	    pkgp = PARSEP->rootp()->dollarUnitPkgAddp();
 	    SYMP->reinsert(pkgp, SYMP->symRootp());  // Don't push/pop scope as they're global
+	} else {
+	    pkgp = symp->nodep()->castPackage(); 
 	}
 	return pkgp;
     }