Fix GCC lint complaint of calling NULL->cloneTree. No functional change intended.

src/V3Ast.cpp

@@ -646,7 +646,7 @@ AstNode* AstNode::cloneTreeIterList() {
 }
 
 AstNode* AstNode::cloneTree(bool cloneNextLink) {
-    if (!this) return NULL;  // verilog.y relies on this
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
     this->debugTreeChange("-cloneThs: ", __LINE__, cloneNextLink);
     cloneClearTree();
     AstNode* newp;

src/V3Ast.h

@@ -1312,6 +1312,8 @@ public:
     virtual void addBeforeStmt(AstNode* newp, AstNode* belowp);  // When calling, "this" is second argument
 
     // METHODS - Iterate on a tree
+    static AstNode* cloneTreeNull(AstNode* nodep, bool cloneNextLink) {  // Clone or return NULL if NULL
+        return nodep ? nodep->cloneTree(cloneNextLink) : NULL; }
     AstNode*	cloneTree(bool cloneNextLink);
     bool	gateTree() { return gateTreeIter(); }  // Is tree isGateOptimizable?
     bool        sameTree(const AstNode* node2p) const;  // Does tree of this == node2p?
@@ -1373,6 +1375,8 @@ inline void AstNRelinker::relink(AstNode* newp) { newp->AstNode::relink(this); }
 
 #define ASTNODE_BASE_FUNCS(name)	\
     virtual ~Ast ##name() {} \
+    static Ast ##name * cloneTreeNull(Ast ##name * nodep, bool cloneNextLink) { \
+        return nodep ? nodep->cloneTree(cloneNextLink) : NULL; } \
     Ast ##name * cloneTree(bool cloneNext) { return static_cast<Ast ##name *>(AstNode::cloneTree(cloneNext)); } \
     Ast ##name * clonep() const { return static_cast<Ast ##name *>(AstNode::clonep()); }
 

src/V3AstNodes.h

@@ -30,9 +30,11 @@
 
 #define ASTNODE_NODE_FUNCS(name) \
     virtual ~Ast ##name() {} \
+    virtual void accept(AstNVisitor& v) { v.visit(this); } \
     virtual AstType type() const { return AstType::at ## name; } \
     virtual AstNode* clone() { return new Ast ##name (*this); } \
-    virtual void accept(AstNVisitor& v) { v.visit(this); } \
+    static Ast ##name * cloneTreeNull(Ast ##name * nodep, bool cloneNextLink) { \
+        return nodep ? nodep->cloneTree(cloneNextLink) : NULL; } \
     Ast ##name * cloneTree(bool cloneNext) { return static_cast<Ast ##name *>(AstNode::cloneTree(cloneNext)); } \
     Ast ##name * clonep() const { return static_cast<Ast ##name *>(AstNode::clonep()); }
 

src/V3Premit.cpp

@@ -383,7 +383,7 @@ private:
 	    } else {
 		UINFO(4,"Autoflush "<<nodep<<endl);
 		nodep->addNextHere(new AstFFlush(nodep->fileline(),
-						 nodep->filep()->cloneTree(true)));
+						 AstNode::cloneTreeNull(nodep->filep(), true)));
 	    }
 	}
     }

src/V3Task.cpp

@@ -361,7 +361,7 @@ private:
     AstNode* createInlinedFTask(AstNodeFTaskRef* refp, const string& namePrefix, AstVarScope* outvscp) {
 	// outvscp is the variable for functions only, if NULL, it's a task
 	if (!refp->taskp()) refp->v3fatalSrc("Unlinked?");
-	AstNode* newbodysp = refp->taskp()->stmtsp()->cloneTree(true);  // Maybe NULL
+	AstNode* newbodysp = AstNode::cloneTreeNull(refp->taskp()->stmtsp(), true);  // Maybe NULL
 	AstNode* beginp = new AstComment(refp->fileline(), (string)("Function: ")+refp->name());
 	if (newbodysp) beginp->addNext(newbodysp);
 	if (debug()>=9) { beginp->dumpTreeAndNext(cout,"-newbegi:"); }

src/verilog.y

@@ -1444,7 +1444,8 @@ member_decl_assignment<memberp>:	// Derived from IEEE: variable_decl_assignment
 	//			// At present we allow only packed structures/unions.  So this is different from variable_decl_assignment
 		id variable_dimensionListE
 			{ if ($2) $2->v3error("Unsupported: Unpacked array in packed struct/union");
-			  $$ = new AstMemberDType($<fl>1, *$1, VFlagChildDType(), GRAMMARP->m_memDTypep->cloneTree(true));
+			  $$ = new AstMemberDType($<fl>1, *$1, VFlagChildDType(),
+						  AstNodeDType::cloneTreeNull(GRAMMARP->m_memDTypep, true));
                           PARSEP->tagNodep($$);
                           }
 	|	id variable_dimensionListE '=' variable_declExpr
@@ -2102,10 +2103,12 @@ instnameList<nodep>:
 
 instnameParen<cellp>:
 	//			// Must clone m_instParamp as may be comma'ed list of instances
-		id instRangeE '(' cellpinList ')'	{ $$ = new AstCell($<fl>1,*$1,GRAMMARP->m_instModule,$4,  GRAMMARP->m_instParamp->cloneTree(true),
+		id instRangeE '(' cellpinList ')'	{ $$ = new AstCell($<fl>1, *$1, GRAMMARP->m_instModule, $4,
+									   AstPin::cloneTreeNull(GRAMMARP->m_instParamp, true),
                                                                            GRAMMARP->scrubRange($2));
 						          $$->trace(GRAMMARP->allTracingOn($<fl>1)); }
-	|	id instRangeE 				{ $$ = new AstCell($<fl>1,*$1,GRAMMARP->m_instModule,NULL,GRAMMARP->m_instParamp->cloneTree(true),
+	|	id instRangeE 				{ $$ = new AstCell($<fl>1, *$1, GRAMMARP->m_instModule, NULL,
+									   AstPin::cloneTreeNull(GRAMMARP->m_instParamp, true),
                                                                            GRAMMARP->scrubRange($2));
 						          $$->trace(GRAMMARP->allTracingOn($<fl>1)); }
 	//UNSUP	instRangeE '(' cellpinList ')'		{ UNSUP } // UDP
@@ -2375,7 +2378,11 @@ statement_item<nodep>:		// IEEE: statement_item
 	//			// for's first ';' is in for_initalization
 	|	yFOR '(' for_initialization expr ';' for_stepE ')' stmtBlock
 							{ $$ = new AstBegin($1,"",$3); $3->addNext(new AstWhile($1, $4,$8,$6)); }
-	|	yDO stmtBlock yWHILE '(' expr ')' ';'	{ $$ = $2->cloneTree(true); $$->addNext(new AstWhile($1,$5,$2));}
+	|	yDO stmtBlock yWHILE '(' expr ')' ';'	{ if ($2) {
+							     $$ = $2->cloneTree(true);
+							     $$->addNext(new AstWhile($1,$5,$2));
+							  }
+							  else $$ = new AstWhile($1,$5,NULL); }
 	//			// IEEE says array_identifier here, but dotted accepted in VMM and 1800-2009
 	|	yFOREACH '(' idClassForeach '[' loop_variables ']' ')' stmtBlock	{ $$ = new AstForeach($1,$3,$5,$8); }
 	//