diff --git a/src/V3Ast.cpp b/src/V3Ast.cpp
index cf13740e2..e952f5493 100644
--- a/src/V3Ast.cpp
+++ b/src/V3Ast.cpp
@@ -239,7 +239,7 @@ AstNode* AstNode::addNext(AstNode* newp) {
     UASSERT(newp,"Null item passed to addNext\n");
     this->debugTreeChange("-addNextThs: ", __LINE__, false);
     newp->debugTreeChange("-addNextNew: ", __LINE__, true);
-    if (this == NULL) {
+    if (!this) {
 	return (newp);
     } else {
 	// Find end of old list
@@ -754,7 +754,6 @@ void AstNode::iterateAndNext(AstNVisitor& v, AstNUser* vup) {
     // This is a very hot function
     // IMPORTANT: If you replace a node that's the target of this iterator,
     // then the NEW node will be iterated on next, it isn't skipped!
-    // if (!this) return;  // Part of for()
     // Future versions of this function may require the node to have a back to be iterated;
     // there's no lower level reason yet though the back must exist.
     AstNode* nodep=this;
diff --git a/src/V3FileLine.cpp b/src/V3FileLine.cpp
index 0d8eb9533..181091856 100644
--- a/src/V3FileLine.cpp
+++ b/src/V3FileLine.cpp
@@ -110,7 +110,7 @@ void FileLine::lineDirective(const char* textp, int& enterExitRef) {
     const char *ln = textp;
     while (*textp && !isspace(*textp)) textp++;
     if (isdigit(*ln)) {
-	this->lineno(atoi(ln));
+	lineno(atoi(ln));
     }
     while (*textp && (isspace(*textp) || *textp=='"')) textp++;
 
@@ -120,7 +120,7 @@ void FileLine::lineDirective(const char* textp, int& enterExitRef) {
     if (textp != fn) {
 	string strfn = fn;
 	strfn = strfn.substr(0, textp-fn);
-	this->filename(strfn);
+	filename(strfn);
     }
 
     // Grab level
@@ -229,7 +229,7 @@ void FileLine::modifyStateInherit(const FileLine* fromp) {
     for (int codei=V3ErrorCode::EC_MIN; codei<V3ErrorCode::_ENUM_MAX; codei++) {
 	V3ErrorCode code = (V3ErrorCode)codei;
 	if (fromp->warnIsOff(code)) {
-	    this->warnOff(code, true);
+	    warnOff(code, true);
 	}
     }
 }
@@ -246,7 +246,7 @@ void FileLine::v3errorEnd(ostringstream& str) {
 }
 
 string FileLine::warnMore() const {
-    if (this && m_lineno) {
+    if (m_lineno) {
 	return V3Error::warnMore()+ascii()+": ";
     } else {
 	return V3Error::warnMore();
diff --git a/src/V3LinkDot.cpp b/src/V3LinkDot.cpp
index 5aea0de48..7d93abeb6 100644
--- a/src/V3LinkDot.cpp
+++ b/src/V3LinkDot.cpp
@@ -2110,7 +2110,7 @@ private:
 	    taskp->dpiExport(true);
 	    if (nodep->cname()!="") taskp->cname(nodep->cname());
 	}
-	nodep->unlinkFrBack()->deleteTree();
+	nodep->unlinkFrBack()->deleteTree(); VL_DANGLING(nodep);
     }
     virtual void visit(AstPackageImport* nodep, AstNUser*) {
 	// No longer needed